STUDY OF ADVERSE EFFECTS OF SOLID
WASTES FROM ALL MINING ACTIVITIES
ON THE ENVIRONMENT
PEDCo ENVIRONMENTAL
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PEDCo ENVIRONMENTAL
11499 CHESTER ROAD
CINCINNATI. OHIO 4.5246
(513) 7B2-A7OO
STUDY OF ADVERSE EFFECTS OF SOLID
WASTES FROM ALL MINING ACTIVITIES
ON THE ENVIRONMENT
Prepared by
PEDCo Environmental, Inc,
11499 Chester Road
Cincinnati, Ohio 45246
Contract No. 68-01-4700
Prepared for
U.S. Environmental Protection Agency
Industrial Extraction Processes Division
401 M. Street Southwest
Washington, D.C.
January 10, 1979
CHESTER TOWERS
BRANCH OFFICES
Crown Canter
Kansas City. Mo.
Professional Village
Cnapel HIM. IM.C.
-------
This report has been reviewed by the U.S. Environmental
Protection Agency and approved for publication. Approval does
not signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or
recommendation for use by the U.S. Government.
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PREFACE
This report presents the results of a study of the adverse
environmental effects of solid wastes generated by the mining
industry, which herein is considered to encompass the recovery of
metallic ores, nonmetallic ores, and solid mineral fuels (coal).*v.
Solid wastes include those from both mining and beneficiation of
ores, including leaching, but exclude those from roasting,
smelting, refining, and other chemical processing.
This study, conducted by PEDCo Environmental, Inc.,
Cincinnati, Ohio, under Contract No. 68-01-4700, is intended to
assist the U.S. Environmental Protection Agency (EPA) in
determining whether the disposal of mineral resource wastes
should be regulated; if so, how; and if not, why not.
The EPA Project Officers were Don O'Bryan of the Industrial
Extraction Processes Division, Office of Energy, Minerals and
Industry; and Jon Perry of the Office of Solid Waste Management
Programs, and subsequently Jack Hubbard of the Resource Extraction
and Handling Division, Industrial Environmental Research
Laboratory. Their guidance and advice throughout the project are
gratefully acknowledged.
* Solid mineral fuels in this study include only coal.
Uranium was addressed under the metallic ores category. Oil shale,
which is a solid mineral fuel, was not specifically addressed in
this study; however, the study report does reference the fact that
the expected expansion in this industry could substantially
increase the annual production of mineral resource solid waste.
iii
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The PEDCo project director was Richard 0. Toftner, the
project manager was Robert S. Amick, and the assistant project
manager was Jack S. Greber. Principal investigators and authors
were Robert S. Amick, Jack S. Greber, Robert L. Hearn, Robert L.
Hoye, and A. Christian Worrell/ III. Technical assistance was
provided by Dr. Roy E. Williams, professor of hydrogeology at the
University of Idaho and senior mining consultant.
Many other individuals and organizations also contributed to
the study. The following were especially helpful in offering
their advice and assistance in arranging contacts with the mining
industry: David R. Cole, Colorado Mining Association;
C. Christopher Hagy, China Clay Association; Erland G. Johnson,
Arizona Mining Association; Karl W. Mote, Northwest Mining
Association; and James R. Walpole, American Mining Congress.
Several Federal and state governmental agencies provided
valuable data. Some of the personnel at these agencies who
provided helpful input are Paul Marcus, Monte Shirts, and John
Morning, U.S. Bureau of Mines, Washington, D.C.; Roy Soderberg,
U.S. Bureau of Mines, Spokane, Washington; Tim Fields, Kurt
Jakobsen, Bruce Weddle, Al Galli, and Ron Kirby, U.S. Environmental
Protection Agency, Washington, D.C.; Ronald Hill, U.S.
Environmental Protection Agency, Cincinnati, Ohio; Dr. Dave
Maneval, Appalachian Regional Commission, Washington, D.C.;
Edward Johnson, U.S. Forest Service, Washington, D.C.; Kenes
Bowling, Interstate Mining Compact, Lexington, Kentucky; and
Sanford Darby, Georgia Department of Natural Resources, Macon,
Georgia.
iv
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Finally, the cooperation of mining companies and their
representatives who provided pertinent information during site
visits is gratefully acknowledged. The following companies were
particularly helpful: Erie Mining Company, Hoyt Lakes, Minnesota;
Consolidation Coal Company, Pittsburgh, Pennsylvania; Colowyo
Coal Company, Craig, Colorado; Energy Fuels Corporation,
Steamboat Springs, Colorado; Freeport Kaolin Company, Gordon,
Georgia; Engelhard Minerals and Chemicals Corporation, Mcltyre,
Georgia; J.M. Huber Corporation, Huber, Georgia; International
Minerals Corporation, Bartow, Florida; Agrico Chemical Company,
Bartow, Florida; Union Carbide Corporation, Uravan, Colorado;
Western Nuclear, Inc., Wellpinit, Washington; Dawn Mining Company,
Spokane, Washington; Duval Sierrita Corporation, Tucson, Arizona;
Cyprus Pima Mining Company, Tucson, Arizona; Magma Copper Company,
San Manuel, Arizona; Hecla Mining Company, Wallace, Idaho; Climax
Molybdenum Company (AMAX, Inc.), Climax, Colorado; Climax
Molybdenum Company (AMAX, Inc.), Leadville, Colorado; Environmental
Services, Inc. (AMAX, Inc.), Denver, Colorado. All of the
individuals whom we met at these facilities were cooperative and
helpful.
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CONTENTS
Page
PREFACE iii
TABLES ix
FIGURES xi
CONVERSION FACTORS xii
SI UNITS . Xiv
EXECUTIVE SUMMARY XV
Background and Scope xv
Study and Approach xix
Industry Profile xxi
Sources, Quantities, and Characteristics of
Mineral Resource Solid Wastes xxvii
Mining Waste Disposal, Stabilization, and Control. xxxvii
Environmental and Health Assessment xlvii
Laws and Regulations xlix
Identification of Mineral Resource Solid Waste
Problems by Industry Ixi
References for Executive Summary Ixv
1 INTRODUCTION . '. 1
2 INDUSTRY PROFILE 12
Nature of Mining Industry 13
Magnitude of the Mining Industry 41
References for Section 2 58
3 SOURCES, QUANTITIES, AND CHARACTERISTICS OF
MINERAL RESOURCE SOLID WASTES ... 60
Sources and Classification of Mineral Resource
Solid Wastes 61
vi
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CONTENTS
Page
Quantities of Mineral Resource Solid Wastes . . 68
Land Impacted by Mineral Waste Disposal .... 79
Characteristics of Mineral Resource Solid Wastes 82
References for Section 3 108
RECLAMATION—DISPOSAL, STABILIZATION,; AND CONTROL 111
Site Selection and Mine Design 112
Disposal of Overburden and Waste Rock 118
Stabilization/Control/Reclamation 139
References for Section 4 154
ENVIRONMENTAL AND HEALTH ASSESSMENT 157
Atmospheric Pollution 158
Water Pollution 164
Effects on Physiography 178
Effects on Flora and Fauna . 181
Impacts on Human Health and Welfare 185
References for Section 5 197
LAWS AND REGULATIONS 200
Federal Regulations 202
State Laws and Regulations 223
Local Laws and Regulations 232
IDENTIFICATION OF POTENTIAL PROBLEM AREAS
ASSOCIATED WITH MINERAL RESOURCE WASTES .... 237
Acid-Forming Mineral Resource Wastes 238
vii
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CONTENTS
Page
Mineral Resource Wastes Containing Radioactive
Materials 244
Other Potentially Hazardous Mineral Resource
Wastes 251
Combining of Mineral Resource Wastes 264
Airborne Fugitive Emissions From Mine Wastes and
Tailings Ponds 265
Identification of Mineral Resource Solid Waste
Problems by Industry 267
References for Section 7 271
Appendix A 274
Appendix B 276
Appendix C 284
Appendix D 300
Glossary 301
Vlll
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LIST OF TABLES
No. Title Page
1 Abandoned and Inactive Underground Mines in the
United States as of 1966 44
2 Primary Production Statistics for the Domestic
Mineral Commodities 45
3 Land Utilization by the Mining Industry in the
United States in 1930-71, by State and Function . 51
4 Comparison of Land Uses in the United States in 1971 53
5 Status of Land Disturbed by Surface Mining in the
United States as of July 1, 1977, by States ... 56
6 Status of Land Disturbed by Surface Mining in the
United States from January 1, 1965, to July 1, 1977 57
7 1975 Solid Waste Production Statistics at Surface
and Underground Mines and Estimated Total Solid
Wastes for 1977, 1985, and 2000 70
8 Mineralogic and Lithologic Summary of Mineral Deposits 90
9 Grain Size Distribution of Molybdenum Tailings at
the.Climax Molybdenum Company Mines 103
10 Methods Employed for the Disposal, Stabilization,
and Control of Solid Wastes Generated by Mining/
Beneficiating Operations 113
11 Chemical Binding Surface Treatments in Descending
Order of Rank by the USBM, Salt Lake City .... 146
12 Cost Comparison of Stabilization Methods 149
13 Fugitive Dust Emissions from Selected Coal Surface
Mining Operations 160
14 Summary of Estimated Emissions from Some Mining
Operations 161
15 Characteristics of Seepage Water from a Tailings
Pile in Elliot Lake, Ontario 165
16 Summary of Sources of Acid and Heavy Metal Pollution 169
17 Summary of Types of Pollution and Length of Stream
Affected 170
ix
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LIST OF TABLES
No. Title Page
18 Characteristics of Runoff from Coal Mine Wastes in
the Shawnee National Forest/ Southern Illinois . 172
19 Concentrations of Sulfuric Acid that are Toxic to
20
21
22
23
Fish
A Classification of the Effects of Metals
Body Burden, Human Daily Intake, and Content in the
Earth's Crust of Selected Elements .
Tolerance Levels for Metals in Drinking Water and
184
187
188
189
Results of Sampling of Community Water Supplies
24
25
26
Metal Carcinogenesis in Experimental Animals . . .
Effects of Mfitals on Reproduction
Ranking of Potential Environmental Impact by Mineral
191
192
268
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LIBRARY
U S.
" LIST OF FIGURES
No. Title Page
1 The scope of mining activities can be divided into
three major phases 17
2 Room-and-pillar mining is the most common underground
method used in the United States 23
3 In open-stope mining, no pillars are left to support
the walls 25
4 Stull stoping can be used to mine narrow veins ... 26
5 In shrinkage stoping, the ore deposit is stoped from
beneath 27
6 The block caving method is used to mine large ore
bodies covered by barren or low-grade capping that
is too thick to strip away 29
7 Area strip mining is performed by digging successive
trenches and refilling each as the next one is dug 32
8 Contour stripping is used to remove mineral outcrops
around hillsides 34
9 Open pit mining is a surface mining technique used
when ore deposits are near the surface 35
10 This generalized flowsheet shows the processes
involved in extensive beneficiation 38
11 Geographic distribution of land utilized by mining
activities 1930-71 is depicted graphically .... 52
12 Land utilized by mining is shown by selected
commodity, 1930-71 54
13 Land usage by mining in the United States, 1930-71,
is shown according to function 55
14 This photo shows an example of mine wastes and
tailings at an inactive mine site 77
15 The ratio of land reclaimed by the mining industry
to that used doubled in 1971 compared with the
ratio for the 42-year period between 1930 and 1971 81
16 This diagram shows a modified block cut 121
XI
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LIST OF FIGURES
No.
17
18
19
20
21
22
23
24
Title
This figure shows box-cut mining using two cuts . .
This figure illustrates square-set stoping, a type
Shown above are the three basic methods of tailings
Some methods used to minimize seepage outflow are
There are various routes of water gain and loss at
Solubilities of oxides and hydroxides of various
metals are related to pH
In Pennsylvania the responsibility of overseeing the
coal mining industry is divided as illustrated . .
In Kentucky the responsibility of overseeing the
Page
122
126
129
131
151
173
230
coal industry is divided as illustrated 231
xii
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CONVERSION FACTORS
To convert
Inches
Feet
Miles (statute)
Square feet
Acres
Cubic feet
Cubic yards
Gallons
Gallons
Ounces (troy)
Pounds
Tons (short)
To
Centimeters
Meters
Kilometers
Square meters
Hectares
Cubic meters
Cubic meters
Cubic meters
Liters
Grams
Kilograms
Megagrams
Multiply by
2.540
0.3048
1.609
0.0929
0.4047
0.0283
0.7645
0.003785
3.785
31.103
0.4537
0.907
Xlll
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Quantity
Length
Mass
Time
Temperature
BASIC SI UNITS
Name
meter
kilogram
second
Kelvin
DERIVED SI UNITS
Symbol
m
kg
s
K
Quantity
Area
Volume
Density
Factor by which unit
is multiplied
1012
109
106
103
102
10 :
ID'1
ID'2
io-3
ID'6
ID'9
ID'12
ID'15
io-18
Name
square meter
cubic meter
kilogram/meter
SI PREFIXES
Prefix
tera
giga
mega
kilo
hecto
deka
deci
centi
milli
micro
nano
pico
femto
at to
Symbol
m2
m3
kg/m3
Symbol
T
G
M
k
h
da
d
c
m
y
n
P
f
a
XIV
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EXECUTIVE SUMMARY
Background and Scope
The U.S. mining industry generates about 2.3 billion tons
(2.1 petagrams) of solid wastes each year. These wastes, second
only to agricultural wastes in magnitude, account for about 40
percent of total solid wastes generated annually in the United
States. The rate of mineral resource solid waste generation has
more than doubled since 1967.
For purposes of this investigation, solid wastes are
considered to be those wastes from both mining (surface and
underground) and beneficiation (e.g., crushing, screening, and
concentrating), including leaching.* They do not include wastes
from roasting, smelting, refining, and other chemical processing,
even though these wastes are sometimes discarded in tailings
ponds, whereupon they constitute the primary source of hazardous
materials in the tailings pond.
As might be expected, problems associated with the handling
and disposal of mineral resource solid wastes have multiplied as
quantities have increased. For example, waste impoundments have
failed, and the resulting disasters have cost lives and been
* Although leaching is addressed in this study, the
quantities of waste associated with leaching operations are not
included because they are almost impossible to calculate.
xv
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detrimental to the environment. Then, too, recent studies
indicate that some mineral resource wastes can be harmful,
particularly those containing heavy metals, radioactive materials,
or acid-forming minerals.
Despite the above, Congress recently concluded that
information regarding these potential dangers is insufficient to
form the basis for regulatory action and mandated a study of
these wastes under the authority of Section 8002(f) of
P.L. 94-580, the Resource Conservation and Recovery Act of 1976.
The U.S. Environmental Protection Agency was directed to conduct
this study.
The scope and objective of the study are described in the
following excerpt from Section 8002(f), MINING WASTE: -
"The Administrator, in consultation with the Secretary of
the Interior, shall conduct a detailed and comprehensive
study on the adverse effects of solid wastes from active and
abandoned surface and underground mines on the environment,
including, but not limited to, the effects of such wastes on
humans, water, air, health, welfare, and natural resources,
and on the adequacy of means and measures currently employed
by the mining industry, Government agencies, and others to
dispose of and utilize such solid wastes and to prevent or
substantially mitigate such adverse effects. Such study
shall include an analysis of -
(1) the sources and volume of discarded material
generated per year from mining;
(2) present disposal practices;
(3) potential dangers to human health and the
environment from surface runoff of leachate and air
pollution by dust;
(4) alternatives to current disposal methods;
(5) the cost of those alternatives in terms of
the impact on mine product costs; and
(6) potential for use of discarded material as a
secondary source of the mine product.
xv i
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In furtherance of this study, the Administrator shall, as he
deems appropriate, review studies and other actions of other
Federal agencies concerning such wastes with a view toward
avoiding duplication of effort and the need to expedite such
study. The Administrator shall publish a report of such
study and shall include appropriate findings and
recommendations for Federal and non-Federal actions
concerning such effects."
This technical document is in response to the study outlined
above. Emphasis has been placed on whether or not the disposal
of mineral resource solid wastes should be regulated and by what
means. This document does not make recommendations for such
regulation; its purpose is to provide data .for use by those who
will make these recommendations.
As a result of this investigation the EPA may reach one of
the following conclusions:
(1) Mineral resource solid wastes should not be regulated
further because they are being properly handled and
disposed of at this time, and the handling and disposal
of the wastes are being properly regulated by existing
Federal, state, and/or local regulations.
(2) The handling and disposal of mineral resource solid
wastes are not being properly regulated at this time;
therefore the appropriate sections of the Resource
Conservation and Recovery Act should be applied to
assure the proper regulation of these wastes.
(3) The handling and disposal of mineral resource solid
wastes are not being properly regulated at this time
and additional regulation is needed, but the Resource
Conservation and Recovery Act is not the proper vehicle
to use to impose these regulations.
(4) Even with this study, the information available is not
sufficient to make a decision concerning the regulation
of mineral resource solid wastes; therefore additional
studies are needed to secure this information.
In this study mineral resource solid wastes are separated
into three categories: (1) mine wastes, (2) beneficiation wastes,
xvi i
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(3) miscellaneous wastes. Mine wastes are those undesirable
materials extracted along with ores. Beneficiation wastes (or
tailings) are the materials discarded during ore processing.
Miscellaneous wastes are minor wastes such as site preparation
wastes (e.g., drilling muds and removed vegetation), construction
wastes (e.g., scrap iron and wood), damaged or used reagent or
product containers, domestic sewage sludges, and residuals from
pollution control equipment. The wastes in this last category
are minor in volume and importance; therefore little attention is
given to them in this study.
It is not certain which, if any, mineral resource solid
wastes are actually covered by the Resource Conservation and
Recovery Act. The following exceptions stated in the act would
seem to eliminate at least some of them:
(1) Industrial discharges, which are point sources subject
to NPDES permits (Subtitle A, Section 1004, parenthesis
27) .
(2) Source, special nuclear, or byproduct material as
defined by the Atomic Energy Act of 1954, as amended
(Subtitle A, Section 1004, parenthesis 27).
At many of the active .mine sites, waste disposal areas will
eventually be rehabilitated or reclaimed to some extent.*
Moreover, the amount of land being reclaimed annually by mine
operators in some states actually exceeds the amount disturbed
* As of August 3, 1977, the coal mining industry is required
to reclaim all land disturbed by surface mining activities, as
well as land disturbed by the surface effects of underground
mining.
xvi 11
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because part of the lands being reclaimed are those that were
devastated by mining activities before passage of surface mining
and reclamation legislation. Despite these positive aspects,
solid wastes generated by mining activities still pose a threat
to the environment because (1) little was done before the late
sixties to control and rehabilitate waste disposal areas, thus
large amounts of unstabilized wastes had already accumulated; (2)
there is often no one to assume responsibility for the large
quantities of waste materials at the numerous inactive mining
sites; (3) although they may eventually be stabilized and
reclaimed, wastes generated at active mines pose a threat to the
environment until such action is taken; (4) because of poor
reclamation techniques and a lack of maintenance programs, some
reclaimed lands may ultimately revert to unreclaimed condition.
Study Approach
As much information as possible was acquired, compiled, and
analyzed, given the time constraints and broad scope (all mining
industries) of the study. This information formed the data base
i
report for the technical study and document.
Data gathering involved four major tasks. The first was to
search the literature for information (published and unpublished)
dealing with the generation, control, regulation, and environmental
effects of mineral resource solid wastes. This task required
several computerized searches and contacting a number of public,
academic, and governmental libraries.
xix
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The second task was to contact various governmental agencies
whose realm of responsibility includes the mining industry and/or
effects of the industry. Information was obtained in the form of
documentation (published and unpublished) and personal
communications. (The agencies and personnel contacted are listed
in Appendix A.)
The third task was to contact various trade associations
that could provide industry contacts, furnish answers to both
general and specific questions, and help arrange mine site
visits. A total of six such mining associations were contacted.
The final task was to visit mine sites to obtain specific
operational and solid waste data and to solicit opinions and
input from mining personnel regarding the issues of the project.
Selection of sites to be visited was based on the following
criteria: (1) the volume of waste generated by a particular
industry; (2) the number of mines comprising an industry and
their geographic distribution; (3) the importance of the
materials contained in the solid wastes (e.g., heavy metals,
radioactive constituents, acid forming materials) generated by
the various industries. The nineteen sites visited represented
nine industries: copper, iron, coal, phosphate, uranium, lead,
zinc, silver, and molybdenum.
xx
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Industry Profile
Ores recovered in the United States fall into one of three
categories: metals, nonmetals, or solid mineral fuels.* Deposits
of these ores range from unconsolidated surface deposits to deep
orebodies. An ore may contain only one recoverable commodity, as
is common with the nonmetallic ores, or it may be comprised of a
combination of recoverable commodities, as is common with the
metallic ores. The value of the associated minerals (coproducts
and/or byproducts) often makes an otherwise unprofitable orebody
economically recoverable.
Mining industry activities take place in three distinct
phases. Phase I involves the prospecting and exploration
required to locate, characterize, and prove a potential orebody.
Phase II involves extraction of the ore, which may be accomplished
by various 'underground or surface mining techniques. The
extraction method is determined by the characteristics of the
deposit and the surrounding parent rock and terrain as well as by
special considerations such as economics, safety regulations, and
ecological considerations. Both surface and underground mining
techniques are practiced in the United States. Surface mining,
an open-air method of extraction, includes placer, strip, open
pit, quarry mines, and some variations and combinations thereof.
* Coal is the only solid mineral fuel covered in this study.
Uranium is addressed under the metallic ores category. Oil shale
is not specifically addressed, but the report does reference the
fact that the expected expansion of this industry could
substantially increase the total amount of mineral resource solid
wastes generated annually.
xx i
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Underground methods include room-and pillar, stope, block caving,
longwall mining, and some variations thereof. Phase III involves
the beneficiation of the extracted ore. (Beneficiation is the
processing of an ore in order to regulate product size, remove
unwanted constituents, and improve its quality, purity, or assay
grade.) The extent of beneficiation required varies from simple
sizing and cleaning to elaborate crushing and flotation schemes.
The beneficiation phase sometimes results in a final product and
sometimes serves only as an intermediate step in the process
flow.
Although each state in the Union has some kind of mining
activity, the volume of crude ore they produce varies greatly;
e.g., in 1975 Delaware produced 985,000 tons (900 gigagrams),
2
whereas Florida produced 241 million tons (220 teragrams).
Total U.S. crude ore production in 1975 was 3.2 billion tons (2.9
petagrams)(Table I), which represents the output of some 21,473
3 4
metal, nonmetal, and bituminous and lignite mines. '
An undetermined number of nonoperating mines (inactive and
abandoned) also continue to have an impact on the environment,
although data are inadequate to assess the total extent of this
impact. An unpublished, report mentioned in a recent publication
indicates there were approximately 88,000 inactive and abandoned
underground mines in 1966. More recent estimates indicate the
present number to be greater than 200,000.
xxi i
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TABLE I
PRIMARY PRODUCTION STATISTICS FOR THE DOMESTIC MINERAL COMMODITIES
X
X
H-
H-
H-
Ratio of crude ore Crude ore production Percent of crude ore
to marketable product (1,000 tons) handled by surface
ComnodUtes 1 ,000 tons: 1,000 tons I97S 1977(e) 1985(e) 2000(e) and underground mines*
METALS
Bauxite 1.7:1 3.290 4,000 4,050 2.700 100 surface
Copper 193.5:1 269.000 288,315 483. 750 735.300 89.1 surface
10.9 underground
Gold 374.815:1 10.120 15.708 26.180 33.880 85.8 surface
14.2 underground
Iron Ore 2.8:1 239.000 162.857 259.200 320.000 96.2 surface
3.8 underground
Lead 17.3:1 9.850 10,197 12.456 16.781 100 underground
Mercury 236.8:1 63 288 225 225 93.4 surface
6.6 underground
Silver 2.165:1 1.100 3.740 4.400 5,000 28. 3 surface
71.7 underground
Uranium 630.9:1 6.940 9,464 22.712 37.854 60.6 surface
39.4 underground
Zinc 7S o., 8,580 11.945 15,480 28.380 0.9 surface
99..1 underground
Otherl ' 61.081 56.200 91.960 130,990
Total metals 609.024 562.673 920,413 1.311.110
Major
associate
mineral st
gallium
gold
silver
lead
molybdenum
copper
lead
silver
platinum group
manganese
titanium
copper
line
copper
gold
silver
none
copper
lead
zinc
antimony
vanadium
molybdenum
copper
lead
cadmium
silver
copper
Major
producing
stalest
Arkansas
Alabama
Georgia
Arizona
Michigan
Utah
New Mexico
South Dakota
Nevada
Arizona
Minnesota
Michigan
Missouri
Idaho
Colorado
Utah
Nevada
California
Alaska
Idaho
Arizona
Colorado
Utah
New Mexico
Wyoming
Tennessee
Missouri
New York
Colorado
Total
number
of nines*
12
61
99
68
33
12
64
164
36
60
609
(continued)
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TABLE I. (continued)
Ratio of crude ore Crude ore production Percent of crude ore
to narketable oroduct (1.000 tons) handled by surface
Commodities I .-000 tons:) .000 tons 1975 1977(e) 1985(e) 2000(e) and underground nines*
Major
associate
•ineralst
Major Total
producing nunber
stalest of nines*
NONMETALS
Asbestos 15.0:1 1.450 1.575 2.400 3.000 100 surface
Clays 1.0:1 43.400 56.251 100,000 190.000 100 surface
—
Oiatomite '-^l 872 956 1.500 3.000 100 surface
Feldspar 1.9:1 1.310 1.454 2.185 3.800 100 surface
X
X
!-••
< Gypsum 1.0:1 10,100 13.900 15.000 20.000 80.8 surface
19.2 underground
Mica (scrap) 7.9:1 521 1.296 1.501 1.849 100 surface
Per lite 1.4:1 706 1.085 1.260 2.240 100 surface
Phosphate rock 3.8:1 186.000 186.200 304.000 323.000 100 surface
none
silica.
sand and
gravel
none
lithiuB
•lea
clays
limestone
clay
clay
feldspar
llthtUB
none
uranium
fluorine
California
Vermont
Arizona
North Carolina
Georgia
Texas
Ohio
North Carolina
California
Kansas
Nevada
Oregon
Washington
North Carolina
Connecticut
Georgia
California
Michigan
California
Te>as •
Iowa
North Carolina
Alabama
Georgia
South Carolina
New Mexico
Arizona
California
Nevada
Florida
North Carolina
3
1.249
IS
18
68
12
12
47
California
Idaho
(continued)
-------
TABLE I. (continued)
Ratio of crude ore Crude ore production
to marketable product (1,000 tons)
Commodities 1>000 tons:!, 000 tons 197S I977(e) 1985(e) ?000(e)
NONMETALS (continued)
Potassium salts 8.6:1 17.600 19,952 17.200
Pumice 1.0:1 3.B90 4,109 6.500
Salt . 1.1:1 . 14,900 47.227 85,580
Sand and gravel 1.0:1 789,000 898,000 1,390.000 2.
* Sodium carbonate 2.0:1 8.010 12.276 22,000
3 (natural)
Stone: crushed 1.0:1 899,000 914,000 1.550,000 2.
Stone: dimension 2.2:1 2,330 3,080 3,300
Talc 1.2:1 645 1.265 2,040
Other" 10.483 10,800 16.200
Total nonmetals 1,990,417 2,173.426 3,247,066 5.
8.600
10.600
142.230
090,000
34,000
500.000
3,300
2,880
26,700
365,199
Percent of crude ore
handled by surface
and underground mines*
100 underground
100 surface
3.2 surface
96.8 underground
100 surface
100 underground
96.2 surface
3.8 underground
96. 1 surface
3.9 underground
75 surface
25 underground
Major
associate
mineral st
none
none
magnesium
bromine
potassium salts
none
none
clay
lithium
gypsum
clay
lithium
gypsum"
none
Major
producing
stalest
New Mexico
Utah
California
Oregon
California
Arizona
Louisiana
Texas
New York
Michigan
California
Alaska
Texas
Michigan
Wyoming
California
Pennsylvania
Illinois
Texas
Missouri
Indiana
Georgia
Vermont
Ohio
Vermont
Montana
New York
Texas
Total
number
of mines*
8
224
19
7.007
3
5.203
381
40
96
14.405
(continued)
-------
TABLE I. (continued)
X
X
Commodities
1975
Crud
1977(e)
le ore production
. (1.000 tons)
198S(eJ 2000 (eT
Percent of crude ore Major
handled by surface associate
and underground mines* Minerals!
Major Total
producing number
stalest of Mines*
SOLID MINERAL FUELS
Coal, anthracite
Coal, bituminous
and lignite
Total mineral fuels
Total all commodities
6.203
648.000
654.203
3.253.400
6.200
685.000
691.200
3.427.300
6.000
993.000
999.000
5.166.500
6.000
1.655,000
1.661.000
8.337.300
94 surfacet none
6 underground
56 surfacett none
44 underground
Pennsylvania
Kentucky
West Virginia
Pennsylvania
Illinois
291 1
6.168tt
6.459
21.478
• U.S. Bureau of Mines. Minerals yearbook, 1975 ed. Washington. U.S. Government Printing Office. 1975.
t U.S. Bureau of Mines. Mineral facts and problems, bicentennial edition. Washington. U.S. Government Printing Office. 1976.
S U.S. Bureau of Mines. Mineral cumnodity summaries 1978. Washington. U.S. Department of the Interior. 1978.
1 Antimony, beryllium, nanganiferous ore, molybdenum, monaiite. nickel, platinum group metals, rare earth metals, tin. titan tun. llaenite.
tungsten, vanadium.
*• Abrasives, aplite. barite. boron minerals, fluorspar, graphite, greensand marl, iron oxide pigments (crude), kyanlte. lithium Minerals.
Magnesite. millstones, olivine. vermiculite.
ft 1977 Keystone Coal Industry Manual. New York. McGraw-Hill Mining Publications. 1977.
(e) Estimate.
Note: Crude ore estimates for the other categories were calculated as a percent of the total crude ore production for each year. The percentage
used was derived from the 1975 data and assumed to be the same for the other y«;ars.
Note: Metric conversion table in front matter.
-------
Sources, Quantities, and Characteristics
of Mineral Resource Solid Wastes
Although mine wastes are generally referred to as overburden
at surface mining operations and waste rock or development waste
rock at underground operations, they are also referred to by such
names as "gob," "spoil," and "refuse." Overburden associated
with the mining of most nonmetallic ores generally consists of
topsoil and other unconsolidated materials (sand, gravel, and
silt) and occasionally weathered bedrock. Overburden associated
with the mining of most metallic ores contains varying amounts of
bedrock in addition to topsoil and other unconsolidated materials.
Waste rock associated with underground mining operations consists
of both the consolidated and unconsolidated materials generated
during various stages of mine development (e.g., shaft, tunnel,
and drift development) and those generated during ore extraction.
The large volumes of solid wastes generated by the
beneficiation of ores are normally referred to as tailings.
Several other terms (grit, slimes, gob, fines, and refuse) are
also used to describe these wastes, but tailings is the term used
throughout this document. Tailings may be wet or dry, depending
on the method of concentration.
Researchers' estimates of total annual generation of mineral
resource solid wastes in the United States vary according to the
number of mineral mining industries covered, the extent of the
processing operations included (e.g., mining and beneficiation
only or mining, beneficiation, smelting, and refining), and the
XXVI1
-------
method of calculation. Most estimates range between 1.6 and 2.0
billion tons (1.4 and 1.8 petagrams) per year. ' '
Annual solid waste production statistics in this study are
calculated from (1) U.S. Bureau of Mines data, (2) values
appearing in various published and unpublished documents, (3)
information provided by the mining industry. Beneficiation waste
quantities are calculated on a dry weight basis. The quantities
of water used to slurry these wastes to impoundments are not
included. Estimates of beneficiation wastes do not include those
associated with leaching operations because it is almost
impossible to calculate these values. In most cases, both mine
and beneficiation waste quantities have been calculated for each
commodity (Table II) . When insufficient data made it 'impossible
to calculate beneficiation wastes for some mineral commodities
(e.g., stone and zinc from surface mines), only mine waste
statistics were presented.
It is also important to note that insufficient data precluded
estimating annual production of mine solid wastes for the coal
industry. Although actual quantitative data are not available,
the amount of mine solid waste (particularly overburden) produced
annually by the coal industry is known to be larger than the
total amount of mine waste generated by all the other industries
combined.*
* Many individuals consider overburden produced by the coal
industry to be a resource rather than a waste because of its use
in reclamation projects. This philosophy is based on the fact
that in recent years most overburden has been reclaimed to some
extent. The Surface Mining Control and Reclamation Act of 1977,
which requires the reclamation of all overburden generated by the
coal industry, has contributed to the support of this philosophy.
xxviii
-------
TABLE II
X
X
H-
X
1975 SOLID WASTE PRODUCTION STATISTICS AT SURFACE AND UNDERGROUND MINES AND ESTIMATED
TOTAL SOLID WASTES FOR 1977, 1985, AND 2000
(1,000 tons)
Commodity
METALS
Bauiite
Copper
Cold
Iron Ore
Lead
Mercury
Silver
Uranium
Zinc
Other"
Total metals
NONMETALS
Asbestos
Clays
Oiatomite
feldspar
Gypsum
Mica (scrip)
Per lite
Phosphate rock
Potassium salts
Pumice
Salt
Sand and gravel
Sodium carbonate (natural)
Stone:
Crushed and broken
Dimension
Talc, soapstone, pyrophyllite
Others*
Total nonmetals
MINERAL FUELS
Coal, anthracite
Coal, bituminous and lignite
Total mineral fuels
Total all commodities
Surface
Mine
Mste
13.300
689,000
9.030
256,000
1
509
21
154,000
4?
44.210
1.166,11?
250
37,100
849
1.980
13.400
254
20
216.000
NA
118
87
NA
NA
71.200
1.210
1.760
27,726
371.954
1.538.066
Solid oast* statistics for 1975*
mining operations Underground mining operations Totals, all mining operations
Tallingst
1.407
237.850
8.560
150.816
1
59
315
4.994
9
9
404.001 1
1.353
9
298
627
500
456
195
137.300
- NA
2
283
39.450tt
NA
P
9
93
9
180.557
584.550
Total
14.707
926.850
17.590
406,816
1
568
336
158.994
42?
44.2100
.570.113
1.603
37. IOOP
1.147
2,607
13,900
710
215.
353,300
NA
120
370
39.4501*
NA
7). 200?
1.210?
1.853
27.7264
552.511
2.122.624
Mine
•aste
M
1.360
212
1.890
2.450
1
348
2.420
2.740
1.173
12.593
w
10
NA
NA
206
NA
NA
U
460
NA
617
NA
4.050
300
NA
9
109
5.761
18.354
Taillngst
U
29.003
1.569
3.779
9.282
1
791
2,735
8.127
f
55.286
W
9
NA
NA
8
NA
NA
W
IS. 760
NA
68J
NA
4.010
0
NA
a>
8
20.461
75.747
Total
U
30.363
1.781
5.669
11,732
1
1.139
$.155
10.867
1.173*
67,879
W
I0»
NA
NA
214
NA
NA
W
16.220
NA
1,300
NA
8,060
3009
NA
9*
1099
26.222
94.101
Mine
•aste
13.300
690.360
9.242
257.890
2.450
509
369
156.420
2.782
45.383
1,178.705
250
37.110
849
1.980
13.606
254
20
216,000
460
118
704
NA
4.050
71.500
1.210
1.769
27.835
377.715
l.596.4<0
Grand 1975 Hasle-to-ore Estimated solid wastes!
Tailingst
1.407
266.853
10.129
154.595
9.282
59
1.106
7.729
8.127
»
459.287
1.353
,1
298
627
508
456
195
137.300
157760
2
966
39.450"
4.010
9
9
93
9
201.018
107.10!"
I07.IOIM
767.406
total
14.707
957,213
19.371
412,485
11.73?
568
1.475
164.149
10.909
45.3839
1.637.992
1,603
37.1109
1.147
2.607
14.114
710
215
353.300
16.220
120
1.670
39.450tt
8.060
71.5009
1.2109
1.862
25,176|»
578,733
107.101*1
I07.IOIH
2.323,J26
ratios
4.47
3.56
1.91
1.73
1.19
9.02
1.34
23.65
1.27
0.74
1.11
0.85
1.31
1.99
1.40
1.36
O.30
1.90
O.91
0.03
0.11
0.05
1.01
0.08
0.52
2.89
2.40
0.17
1977
17,880
1,026.401
30.002
281.743
12.134
2.598
" 5.012
223.824
13,854
41.58%
1.655.036
1.748
48.37W
1.252
2.893
19.460
1,763
326
353,780
18.156
124
5.194
44.900
12.399
73.1209
1 .6029
3.653
25.9200
614.666
116.450
116.450
2.269.702
1985
18.104
1,772.150
95.507
448.935
14.823
2.030
5.896
&37.I39
19.660
68.0508
2.982.294
2.664
86,009
1.965
4,348
21.000
2.041
378
577,600
15.652
195
9.414
69.500
22.220
124.0009
1,7169
5.896
38.880*
983,469
163.810
168.810
4.134,573
2000
12.069
2.617.668
64,710
553.600
19.969
2.030
6.700
895.247
36.043
96.9330
4.304.969
3.330
163.40C9
3.930
7.562
28.000
2.515
672
613.700
7.826
318
15.645
104.500
34.340
200.0009
1.7169
8.323
64.0809
1.259.857
281.350
281.350
5.864.176
(continued)
-------
TABLE II (continued)
• ticept •here Indicated otherwise, all |g?5 solid waste statistics utre adapted from lables ? and II of the Preprint from the
H7S Bureau of Nines Minerals yearbook! Mining and Quarrying Trends in the Metal and Nonmetal Industries; United State! Department
of the Interior. Bureau of Mines.
t Estimated iol Id Haste statistics include hnlh mine xjslrs anrl lailinqs unless nthpruisi- irnlu 4i"-l.
I Tailings are reported on a dry weight basis
• Value less than 500 tons.
• Estimates for tailings not available on these commodities; therefore the solid waste statistics Include mine Haste only.
•• Antimony, beryllium, manganl.fercius ore, molybdenum, nonailte, nickel, plat Inum-group metals, rare-earth metals, titanium, llmenlte,
tungsten, vanadium, and guantlty of metal Items Indicated by symbol W.
tt Abrasives, apllte. barlte. boron minerals, fluorospar. graphite, grrensand marl. Iron oilde pigments (crude), kyanlte, lithium minerals.
magnetite, millstone, ollvtne. venntcullte.
it Sand end gravel tailings estimated as S percent of total material handled.
11 Value obtained from the minerals yearbook. 1975, Volume I; Metals. Minerals and fuels; United States Department of Interior; Bureau of
Mines; U.S. Government Printing Office. Washington, D.C., 1977. This value Includes tailings Haste (coal preparation plant Haste) only. Mine
solid Haste data (overburden and development naste rock) are not available for the coal Industry. Although actual quantitative data are not
available. It Is known that vast quantities of nine naste (particularly overburden) are generated annually by the coal Industry. In fact, the
amount of mine naste produced annually by the coal Industry alone Is probably larger than the total amount of mine waste generated by all other
Industries combined.
M • Withheld to avoid disclosing Individual company confidential data.
HA • Not applicable or values so small that no data Here recorded.
Note: Metric conversion table In front matter.
-------
The calculations made in this study indicate that the mining
industry generated about 2.3 billion tons (2.1 petagrams) of
mineral resource solid wastes in 1975 (Table II). The 1985 and
2000 figures are projected to be at least 4 and 6 billion tons
(4.6 and 5.4 petagrams). Calculations are based on current
ore-to-waste ratios (assuming they will remain relatively constant)
and projected ore production statistics. If ocean and oil shale
mining become major commercial enterprises/ as is expected, the
amount of mining solid waste generated annually could double.
Sixty-eight percent of the mineral resource solid wastes
generated in 1975 were mine waste; 32 percent were beneficiation
waste. Overburden associated with surface mining operations is
by far the largest source of mineral resource solid wastes,
representing about 65 percent of the total generated by all
mining operations in 1975. Total solid wastes (overburden and
tailings) produced at surface mining operations in 1975 were
about 23 times greater than those generated at underground mines.
Mine wastes account for about 12 percent of total wastes
generated at surface mining operations, whereas tailings are the
major source of waste at underground mining operations,
representing about 80 percent of the annual total.
Sixty-five different mining industries generate solid
wastes, but five industries are responsible for 85 percent of the
total. The copper industry is the largest contributor, followed
by the iron, phosphate, uranium, and bituminous coal industries
XXXI
-------
in that order.* All of these major producers use open pit
mining, and as the Nation's mineral reserves become depleted, it
is necessary to mine lower grade ores at increasingly greater
depths. Both factors increase the volumes of solid waste produced
per unit of product produced.
Attempts have been made to estimate the total accumulated
mineral resource solid wastes at both active and inactive mining
sites. An early estimate indicated total mineral solid wastes
accumulated would be about 25 billion tons (22.7 teragrams) by
1972. In a more recent document it was estimated that they
would total approximately 30 billion tons (27.2 teragrams) by
1975. It should be pointed out that these estimates were based
on annual mineral solid waste production statistics; therefore
they do not actually represent the amount of waste deposited in
mine waste heaps and tailings impoundments. For the following
reasons, all the mineral resource waste generated does not end up
in waste heaps or tailings ponds and remain untouched for an
indefinite period of time: (1) some of the waste generated at
underground mines is used to fill in mined-out areas, thus
remaining underground; (2) overburden at some surface mining
operations is used as mine backfill; (3) a portion of the
tailings (sometimes as much as 50 percent) at some underground
mines is backfilled into mined-out areas; (4) tailings and mine
* This comparison does not consider the substantial
quantities of mine solid waste produced annually by the coal
industry.
XXX11
-------
wastes are sometimes used in onsite road and dam construction;
(5) wind and water erosion processes remove mineral resource
wastes from their place .of deposition and spread them over
adjacent and distant land areas. This process is evident in the
yellow stream channel of southern Ohio and West Virginia and in
some valley bottoms covered with tailings in the West.
The characteristics of mineral resource solid wastes can be
described best by analyzing their physical, chemical, and
biological properties. The chemical and physical properties of
these wastes vary considerably, depending on their origin and on
such factors as climate, geograpic location, mining and
beneficiating methods, and disposal practices. Conversely,
biological properties vary little because most freshly deposited
solid wastes are normally void of any flora or fauna.
Mine wastes associated with the extraction of both metallic
and nonmetallic ores consist of glacial till, unsegregated silts,
clays, sands and gravels, and broken bedrock, however, wastes
associated with nonmetallic ores contain less broken bedrock and
more glacial tills, clays, and sands and gravels, and sometimes
(e.g., in the mining of sand and gravel, central Florida
phosphate, and clay) very little bedrock is encountered.
Tailings consist essentially of the finely crushed ore rock
known as gangue; therefore the mineralogical composition
generally corresponds to that of the host rock from which the ore
was derived. Tailings normally contain various mixtures of
quartz, feldspars, carbonates, oxides, ferromagnesian minerals,
xxxiii
-------
and minor amounts of other minerals. They also contain traces
of the reagents that are added during beneficiation. The
physical and chemical characteristics of tailings vary even more
than those of mine wastes. The pyrite content of tailings (and
other mine wastes) is a critical factor in the analysis of
potential impact on the environment. The presence of pyrite
almost inevitably results in the production of acid runoff, acid
seepage or acid mine drainage, and in subsequent difficulties
with reclamation.
The presence of pyrite and some other minerals in mine and
beneficiation wastes means that these wastes are potentially
hazardous to human life and the environment. Usually, wastes
associated with coal and metallic ore mining operations contain
more potentially hazardous materials than those associated with
nonmetallic ore mining operations. In some cases concentrations
of potentially hazardous materials are no greater in the mine
wastes than they are in the land on or in which the wastes are
disposed and therefore do not increase the potential for adverse
impact on the area. Wastes from some uranium and phosphate
mining operations are a possible exception, because some of these
wastes may contain radioactive materials (uranium and radium)
above background levels. Another exception is the wastes from
some operations (particularly eastern coal mining operations and
some metal mining operations) in which the wastes contain
pyrite. If pyrite is present along with water and oxygen, acid
water will form and undesirable materials will become soluble.
xxxiv
-------
Sometimes such potentially hazardous elements as heavy metals or
radioactive materials associated with mine wastes are inert or
chemically stable because of pH and solubility conditions.
Some tailings (particularly those from coal and metallic ore
mining operations) may contain potentially hazardous substances
in higher concentrations than the land on which they are disposed.
The fine-grained texture of tailings also:makes them susceptible
to wind and water erosion. When properly handled and disposed
of, these fine-grained wastes can be contained and stabilized.
There have been several cases in past years, however, where
tailings have not been properly stabilized, and these materials
have resulted in severe deterioration of groundwaters, surface
waters, and the land with which they come in contact.
Almost all mining operations disturb the land surface to
some extent. A U.S. Bureau of Mines report detailing land
utilization by the mining industry during the period from 1930 to
1971 estimated some 3.65 million acres (14.8 square gigameters)
or approximately 0.16 percent of the Nation's land area had been
affected. Of this total, about 59 percent was disturbed by
excavation, 38 percent by solid waste disposal (mine wastes and
tailings), and the remaining 3 percent by subsidence as a result
of underground workings. Unfortunately, these figures do not
reflect land disturbed by mass movement or erosion and
transportation of discarded mineral resource solid wastes by
surface waters. In Idaho, for example, most of the floor of the
valley of the South Fork of the Coeur d'alene River is covered by
XXXV
-------
tailings that have been eroded, transported, and redeposited by
flood waters. Therefore it is clear that the 0.16 figure is too
low.
On a commodity basis, the bituminous coal industry accounted
for 40 percent of the total land used; sand and gravel, 18 percent;
crushed and broken stone, 14 percent; clays and copper, 5 percent
each; iron ore, 3 percent; and phosphate rock,' 2 percent. The
states in which the mining industry has utilized 100,000 acres
(404 square megameters) or more are, in decreasing order of
usage, Pennsylvania, Ohio, Illinois, Kentucky, Indiana, and
California.
The U.S. Bureau of Mines has also estimated that about 40
percent of these 3.65 million acres (14.8 square gigameters) has
been reclaimed to some extent, but the Bureau does not distinguish
among degrees of reclamation. According to the Bureau, 163,000
acres (660 square megameters) of the 206,000 acres (834 square
megameters), or about 79 percent, was reclaimed in 1971, but to
an unknown degree. Thus, the ratio of land reclaimed to land
used had doubled in 1971 compared with the ratio of the previous
42-year period average. The precise meaning of this statistic is
not clear because "reclamation" is not defined. If the statistics
are to be useful in the decision-making process, an effort should
be initiated to evaluate degrees of reclamation. Also, reclaimed
land often evolves toward a condition not significantly different
from unreclaimed land if careful maintenance is not practiced for
several years.
xxxvi
-------
As a result of existing and pending state and Federal
legislation (particularly the Surface.Mining and Reclamation Act
of 1977), the ratio of land disturbed per year to land reclaimed
is expected to continually decrease. In addition, the quality of
land reclamation efforts is expected to increase as a result of
stricter and more specific regulatory requirements. The
provisions in the Surface Mining Control and Reclamation Act for
rehabilitation of abandoned mine lands (orphaned lands) will also
contribute to a decrease in the amount of land left devastated by
mining operations.
Mining Waste Disposal, Stabilization, and Control
With a few exceptions, the technology is well established
for disposal of the over 2 billion tons (1.8 petagrams) of
mineral resource solid wastes generated annually and for
stabilization of these wastes to ensure public safety and to
control air and water pollutants. Overburden and waste rock are
usually placed in waste piles or backfilled into previously
excavated areas during the mining operation. Tailings generated
by beneficiating operations at both surface and underground mines
are usually disposed of in tailings ponds. Techniques are
available to control seepage from leaching these deposits. The
extent of application .of these techniques, however, varies
considerably, both geographically and by the type of mining
industry. Therefore, there are areas (especially abandoned mine
lands) in which the control measures currently being applied are
insufficient to protect human health and the environment.
xxxvii
-------
Stabilization and control technologies encompass a variety
of proven methods for providing structural stability for tailings
dams and overburden/waste rock piles; for preventing the evolution
of excessive fugitive dust from tailings pond slopes/ inactive
tailings, and overburden/waste rock piles; for preventing both
surface and groundwater pollution by seepage and runoff from
tailings ponds and overburden/waste rock piles; and for ultimately
creating a reclaimed area that is permanently satisfactory from
both the functional and aesthetic standpoint.
Currently viable disposal, stabilization, and control
methods are described and discussed in this study according to
type of solid waste (Table III).
Site Selection and Mine Design. Some measures can be taken
prior to developing new mining areas to ensure minimal adverse
impacts on the environment. Careful site selection, planning,
and design can transform an area with potentially adverse
14
conditions into safe solid waste disposal sites. Careful site
selection can also minimize the engineering costs of transforming
an unsuitable site into a usable one.
Initial investigations of the feasibility of a mining,
and/or beneficiating facility must consider the fate of the solid
wastes that will be generated. Historically, the primary concern
has been to locate one or more areas of acceptable size near the
production site. Recently, however, environmental regulations
and greater concern for public safety have introduced new
variables into the site selection process. These variables are
xxxviii
-------
TABLE III
METHODS EMPLOYED FOR THE DISPOSAL, STABILIZATION, AND CONTROL
OF SOLID WASTES GENERATED BY MINING/BENEFICIATING OPERATIONS
Type of solid waste
Disposal method
Stabilization/control method
Overburden (surface mining) and
waste rock (underground mining)
Stockpiles adjacent to surface and under-
ground mines and on the outside slopes of
open pit mines.
X
X
X
p-
X
Tailings from the mills of both
underground and surface mines
Backfilling of previously excavated areas
adjacent to the active overburden removal
at surface mines (block-cut/box-cut mining
method). Backfilling of underground mines
with waste rock.
Utilization as construction material (e.g.,
tailings dam or embankments, highway con-
struction) .
Tailings pond.
(continued)
Maintenance of an angle of repose to prevent
landsliding and/or excessive slope erosion.
Employment of physical (e.g., contouring inter-
ceptor ditches, windbreaks, watering), chemical
(wetting and crusting agents), and vegetative
surface stabilization techniques to control
surface water and fugitive dust pollution.
If pyrite is present in the overburden, separ-
ation and isolation of the overburden in order
to prevent the emission of the associated
hazardous wastes (heavy metals and the corro-
siveness associated with the acid water
produced).
Employment of physical (windbreaks and water-
ing) , chemical (wetting and crushing agents),
and vegetative surface stabilization technique*
to control surface water and fugitive dust
pollution at surface mines. Not generally
applicable to open pit copper mining.
Nothing additional required at underground
mines.
Minimal stabilization/control required, except
for suppression of. .fugitive dust, during trans-
fer and handling. '
For new facilities, conduction of preliminary
site evaluations for ultimate selection of a
location with the least adverse impact on the
environment (if practical, a site with an
impervious material base or with an underlying
aquifer sufficiently depressed to prevent
groundwater contamination, and one which is
removed from accumulation of surface water
runoff).
Construction of the tailings dam and embank-
ments by prescribed engineering design
practices to ensure structural stability.
If the material under a tailings pond has a
saturated hydraulic conductivity greater than
10~7 cm/s, scaling the bottom and inner slopes
of the pond to prevent contamination is neces-
sary if the pond contains hazardous wastes such
as pyrite-rich tailings.
-------
TABLE III (continued)
Type of solid waste
Disposal method
Stabilization/control method
Backfilling underground mines (either by
sluicing or truck hauling)
Elimination or minimizing of tailings pond dis-
charge to surface streams through (1) recycle
of water for sluicing at mill, (2) maintaining
sufficient freeboard on dan, (3) maximizing
pond surface area (through site selection) to
maximize evapotranspiration.
Where elimination of tailings pond discharge to
surface streams is impractical, treatment of
tailings pond to produce an effluent which
meets pertinent water quality standards (e.g.,
addition of lime to aid solids settling and
adjust pH, provision of sufficient retention
time and length-to-depth ratio to allow the re-
quired solids settling time).
Rmploymcnt of physical (windbreaks, intercep-
tor ditches and watering), chemical (wetting
and crusting agents), and vegetative surface
stabilization techniques on tailings dam and
embankment slopes and on dry, inactive areas
of tailings ponds to prevent surface water and
fugitive dust pollution.
Ensure that potential hazardous tailings sluice
water does not make contact with an infiltra-
tion gallery to a subterranean aquifer.
when dry tailings (such as coal gob piles) are
used to backfill underground mines, suppression
of fugitive dust from transfer and handling of
the material.
(continued)
-------
TABLE III (continued)
Type of solid waste
Disposal method
Stabilization/control method
X
Miscellaneous wastes. Includes
mine site development wastes
(e.g.. drilling muds, scalped
vegetation), construction debris,
and domestic garbage from food
consumed on site.
Utilization as construction material (e.g.,
tailings dam or embankments, mining haul
roads, aggregate for asphalt paving mate-
rial and concrete for highway and building
construction) and as agricultural additive
as a fertilizer filler or supplement.
Combination with overburden, waste rock,
and/or tailings.
Separate disposal in sanitary landfill on
or off site.
Lake/marine disposal
Minimal stabilization/control required, except
for suppression of fugitive dust during trans-
fer and handling.
Minimal stabilization/control methods required
in addition to those prescribed above.
Periodic coverage of garbage with inert mate-
rial not subject to emission of fugitive emis-
sions (similar to prescribed sanitary landfill
methodology) .
Very little can be done prior to or after dis-
charge of the tailings to the lake or marine
environment. Isolation of the lake from dis-
charge to surface streams is possible, but not
often practiced.
-------
intended to (1) protect the quality of groundwater from degradation
by leachates emanating from and passing through overburden and
waste rock piles and tailings/ (2) protect surface water from
silt loads and dissolved solid loads generated by erosion and
corrosion of these wastes, (3) prevent fugitive dust from these
wastes, (4) protect human life from catastrophic failure caused
14
by floods or seismic events.
Disposal of Overburden and Waste Rock. An estimated 90
percent of the overburden and waste rock (soil, sand, clay,
shale, gravel, boulders, and other unconsolidated materials) that
are removed to gain access to an orebody are permanently disposed
of in waste piles adjacent to or near the mine. Overburden
from open pit mines is usually discarded on the outside slopes of
the pit. For many years overburden and waste rock have also been
disposed of as part of the normal mining process, by immediately
backfilling them into previously excavated areas (stopes in
underground mines). It is estimated that 10 percent of these
wastes are now being disposed of in this manner, and the trend
is toward increasing this percentage. Some industries
(e.g., practically all coal, kaolinic clay, central Florida
phosphate) are already backfilling almost all their mine wastes.
Utilization of overburden and waste rock as byproducts has
been and will probably continue to be limited almost exclusively
to construction material. Selected portions of these wastes with
sufficient strength and proper drainage characteristics can be
used on site to construct roads and tailings pond embankments.
xlii
-------
Certain wastes that are not easily eroded have also been used to
cover wastes that are less stable and more subject to weathering.
Overburden and waste rock have also been marketed as
construction materials for offsite application. Sometimes mining
companies and the offsite users have an arrangement whereby the
user loads and hauls the material off the mine site without any
exchange of money. Offsite uses include aggregate for concrete
and asphalt mixes, fill material, and subbase for highway
construction. Certain mine wastes may provide a better material
for use in specific applications than conventional materials,
and in some instances, may result in cost savings.
Despite the many potential uses that have been researched
and developed for overburden and waste rock, the vast quantities
generated annually, coupled with the severe economic limitations
associated with shipping distances from remotely located mines,
preclude utilization as a practical means of disposal. The
amount of overburden and waste rock currently used as byproducts
is miniscule (less than 1 percent).
i
Disposal of Tailings. Nearly all (99+ percent) of the
tailings generated annually by beneficiating processes are
disposed of in terrestrial impoundments or tailings ponds. The
rest are backfilled into underground mines, discharged to lakes
or saltwater bodies, or utilized as construction materials
(Table III),15
Tailings are discharged into a pond as a slurry. The slurry
is typically 50 to 85 percent water by weight, but it may be as
xliii
-------
low as 15 percent in oil shale tailings. ' Tailings ponds are
usually situated in small valleys or against hillsides and
contained by a dam. When they are situated in flat areas/ dikes
18
must be built on all sides.
Earth liners are commonly used in tailings ponds. If a
supply of clay or clayey soil is available near the site, this is
generally the most economical liner to use. Tailings slimes with
low permeability can be used, or commercial bentonite, whose
sealing ability is affected by pH, can be added to these clayey
soils to reduce their permeability to acceptable levels.
Artificial liners such as soil cement, petroleum derivatives,
plastic, and rubber are available, but they are more expensive
than earth materials, and earthwork may still be required to
prepare the ground surface. All liner materials must be
18
resistant to possible corrosive effects of the pond liquid.
Some underground metal mines have adopted the practice of
backfilling (usually hydraulically) abandoned stopes with the
14
coarser fraction of tailings. The main advantages are improved
and less expensive recovery of the underground orebody, some
reduction in volume of tailings that must be impounded (reducing
the surface area needed), and lessening of postmining surface
subsidence.
The major disadvantages of hydraulic fill are introduction
of additional water into the mine, occasional spills, and the
necessity of importing material for tailings embankments (because
the removal of so much of the coarse fraction of the tailings
xliv
-------
makes it impossible to construct embankments exclusively of
tailings). Bureau of Mines investigations of the use of
backfilling in the Coeur d'Alene district of northern Idaho
indicate that it should be possible to dispose of a greater
percentage of tailings by filling underground openings than has
19
been the practice. Using tailings as fine as No. 200 sieve
may be feasible, which would mean that 50 percent or more of the
average copper, lead, or zinc tailings from underground mining
19
could be backfilled. Since 1974, the major limitation on this
practice has been the annually high cost of the energy required
to remove excess water from the finer-grained tailings, which is
necessary to achieve the engineering properties required for
underground stability. Fine-grained tailings are not free-draining,
Tailings utilization also is essentially restricted to
construction material, primarily for highways. Onsite uses
include haul road construction, tailings pond embankments, and
aggregate for paving mixtures. Offsite uses include fill for
highway embankments, subbase material for concrete and asphalt
highways, antiskid snow-control material for highways, and
aggregate for concrete and asphalt paving mixes. Some tailings,
however, cannot be used in construction.
Stabilization/Control/Reclamation. The importance of
implementating disposal, stabilization, and control techniques
for mineral resource solid wastes is underscored by the magnitude
of its generation. In the past land reclamation was not practiced
as widely, and today degrees of reclamation vary widely. The
xlv
-------
current trend toward more stringent legislation/ however, is
causing mining companies to become increasingly aware of their
obligation to restore the land and to escalate reclamation
activities. For example, the recent Federal Surface Mining
Control and Reclamation Act is adding a new dimension to
reclamation of coal mine lands.
The high visibility of unsightly coal-preparation waste
piles, especially in the highly populated East, and the fact that
approximately 40 percent of the total land disturbed by past and
present mining activities is the result of coal mining operations
have caused coal mining companies to become leaders in practicing
reclamation concurrently with extraction operations. This
concept is catching on rapidly in other mining industries (such
as copper/ phosphate rock, and iron), even though the mine wastes
from these industries are not yet covered by a Federal reclamation
law.
Restoration of a mined area to the desired condition
involves landscaping, stabilization by physical and chemical
means (especially during ongoing mining activities), soil
amelioration, and revegetation. Company policy and the various
desired goals of reclamation efforts (such as lakes created from
abandoned open pit mines or quarries, grazing lands, park and
recreational areas, crop lands, sports areas, campgrounds,
sanitary landfills, and;home sites) determine the manner and
sequence in which these procedures are applied.
xlvi
-------
Environmental and Health Assessment
Mineral resource solid wastes affect human health and the
environment both directly and indirectly. Direct effects are
obvious (e.g., large areas of land are required for containment
of mine waste), but they do not result from the hazardous
properties of the wastes. It is the indirect or secondary
pollution that can result from these properties.
The direct effects of waste production and disposal on the
physiography and aesthetics of a mining area are apparent. Even
though areas used for waste disposal are revegetated (with
difficulty), the angular configuration commonly associated with
dams or banks often does not blend easily with the existing
landscape. It is not always possible to return the large areas
of land required for waste disposal back to their original state
after mining operations are terminated. Occasionally, however,
reclamation actually improves land use.
Proper design of impoundments and spoil banks is critical.
Failure of refuse banks has resulted in great loss of life and
destruction of property. Two examples are the failure of a coal
waste heap in Aberfan, Wales, in 1966, which killed 144 persons,
and the failure of a coal waste dam in Buffalo Creek, West
Virginia, in 1972, which resulted in the death of 125 persons and
the destruction of hundreds of homes.
Surface water is the environmental medium most significantly
impacted by indirect pollution from mineral resource solid wastes.
Drainage from waste heaps may contain acid-forming materials
xlvii
-------
(primarily pyrite), which raise the acid level beyond the
buffering capacity of streams and have a pH so low as to be
considered corrosive. It is also common for this drainage to
dissolve any heavy metals that may be present. This drainage may
also contain beneficiation reagents and radioactive materials.
Moreover, erosion of overburden piles or waste banks has caused
large volumes of sediment to enter surface waters. Increases in
acidity, alkalinity, turbidity, or metals concentrations are
known to have adverse effects on aquatic life, but the extent of
their effect on humans is unknown.
Groundwater quality is impacted by leachate and/or seepage
from tailings ponds and mine waste piles, which may contain a
variety of undesirable constituents such as radioactive materials,
processing reagents, and heavy metals. The significance of this
impact depends on such factors as climate, the nature of the
soil or rock strata,'and the depth of the water table. Arid
regions of the West should be affected less severely because the
water either evaporates or is recycled. Polluted groundwater may
affect vegetation. Plant uptake of metals depends upon the
chemical form of the metals, soil conditions, and plant species.
The same is true of the:revegetative potential of the actual mine
wastes. The discharge of contaminated groundwaters into streams
can also have an adverse impact on surface waters.
Some atmospheric emissions can be generated by mineral
resource solid wastes. For example, waste banks at coal mines,
when accidentially ignited, emit particulates, sulfur oxides,
xlviii
-------
nitrogen oxides, and hydrocarbons, including benzo(a)pyrene.
Although some of the components of the emissions from mineral
resource wastes are considered hazardous, concentrations are
usually too small to pose a significant threat to human health or
the environment. An exception is the radon gas emitted from
uncovered, dry, uranium tailings. In general, the remoteness of
most large mining operations limits the impact of air emissions
on human health.
Laws and Regulations
The regulatory framework within which'most mines must
operate consists of a rather imposing and oftentimes cumbersome
array of guidelines, criteria, and regulations characterized by
jurisdictional overlapping between and within governmental
levels. This overlapping contributes to confusion and delay on
the part of mine owners and regulators alike. The growing
Federal involvement in the regulation of mining operations,
however, especially in the area of pollution control, has the
potential for reducing or eliminating these differences, thereby
providing a more effective and uniform system for protecting the
environment (Table IV).
Legislation applicable to the control of mineral resource
solid wastes varies, depending on whether the mine is on public
or private land and on the regulations promulgated by each state
and local authority. On public land, the granting of mining
rights under the laws encompassing the Federal mineral leasing
program is generally preceded by preparation of an environmental
xlix
-------
TABLE IV
FEDERAL LAWS AFFECTING THE DISPOSAL OF MINING SOLID WASTES
Environmental Laws Governing Mining
Resource Conservation and Recovery Act of 1976
Surface Mining Control and Reclamation Act of 1977
Mining Laws (not specifically environmental) General Environmental Laws (not specifically mining)
Federal Mineral Leasing Laws: National Environmental Protection Act
U.S. Mining Laws of 1972 Clean Air Act
Mineral Leasing Act of 1920 Clean Air Act Amendments of 1977
Coal Leasing Amendments Act of 1976 Federal Water Pollution Control Act
Minerals Leasing Act For Acquired Land Clean Water Act
Materials Act of 1947 Safe Drinking Water Act
Mining Enforcement and Safety Administration Endangered Species Act of 1973
National Historic Preservation Act
Miscellaneous Laws
Rivers and Harbors Act of 1899 (Section 13, Refuse Act)
Atomic Energy Act of 1974
Energy Reorganization Act of 1974
-------
impact statement required by the National Environmental Policy
Act. On private land, solid waste disposal is generally affected
by a large number of state and local regulatory agencies whose
authority covers the control of mining and beneficiating operations.
Federal air and water quality guidelines have•indirectly affected
the disposal of solid wastes from private mining operations for
some time. The Federal Resource Conservation and Recovery Act
and Surface Mining Control and Reclamation Act, however, have
the potential for the most direct impact on all phases of mining
operations.
The Surface Mining Control and Reclamation Act provides the
states with broad powers, according to Federally approved state
plans, to develop and enforce regulations on surface coal mining
and reclamation operations. It covers surface mining operations
and the surface effects of underground mining operations, but it
applies only to coal mining operations. This leaves the other
mining industries largely within the control of varying state
sponsored regulations. The Resource Conservation and Recovery
Act places strict limitations on the discharge and disposal of
all solid wastes. At the present time its application to the
mining industry and specific mining byproducts remains uncertain.
li
-------
The following points summarize the findings of this
investigation.
1. The three mineral mining categories addressed in this
study (metallic minerals, nonmetallic minerals and
coal) generate as estimated 2.3 billion tons (2.1
petagrams) of mine and beneficiation solid wastes
annually, most of which is disposed of on the land.
The mine wastes (overburden) associated with surface
mining operations are by far the largest source of
mineral resource solid wastes, comprising about 65
percent of the total produced annually. The combined
mine wastes and tailings generated at surface mines are
also much greater in volume than the combined wastes
generated at underground mines. More than 65 different
mining industries generate solid wastes, but 5 of these
are responsible for 85 percent of the total: the
copper industry, which contributes the most, is
followed by iron, phosphate, uranium, and bituminous
coal industries in that order.* Of the three mineral
mining categories, the metallic mineral mining industry
generates the most solid wastes.*
2. Mineral resource wastes associated with most nonmetal
mining operations usually do not contain elements or
compounds that pose a significant threat to human
* This comparison does not consider the substantial
quantities of mine solid wastes produced by the coal industry,
lii
-------
health or the environment. Any potentially hazardous
elements (such as heavy metals or radioactive materials)
that may be associated with these wastes are usually
inert or chemically stable because of pH and solubility
conditions of the wastes; however, some concern has
arisen about hazardous materials associated with the
mineral resource wastes from a few nonmetals mining
industries. Two examples are the wastes from the few
existing asbestos mines and several talc and vermiculite
mines, which contain asbestos fibers; and the wastes
associated with central Florida phosphate mining and
beneficiating operations, which contain some radioactive
constituents.
3. Because the chemical characteristics of mine wastes
associated with coal and metals recovery are more
complex, these wastes pose a more serious threat to the
environment than those associated with nonmetals mining.
Mine wastes from eastern coal mines often contain
unstable sulfide minerals (e.g., pyrite and marcasite),
and the leachate produced by these minerals when they
interact with water is acidic in nature. On the other
hand, wastes from western coal mines, which ordinarily
do not contain pyrite, tend to be alkaline, have a high
pH, and contain a variety of dissolved materials
(primarily salts). The overburden and waste rock
removed during the mining of some metallic ores (e.g.,
liii
-------
copper, lead, zinc, and molybdenum) in the West,
also contain pyrite; and in cases where oxygen and
water are available together, these wastes produce acid
water similar to that produced by eastern coal mine
wastes. Because these wastes also contain heavy metals,
the acid leachate formed contains dissolved metals that
are hazardous to the environment. In the Central Rocky
Mountains, copper, zinc, and arsenic are almost always
associated with acid mine drainage. Best available
estimates indicate that 25 percent of the hard rock or
metallic mineral industries generate mine wastes with
sufficient pyrite to produce acid water. This figure
is estimated to be about 90 to 95 percent for eastern
coal mines, and about 40 to 50 percent for all coal
mines.
4. Beneficiation wastes (tailings) associated with some
metallic ore and eastern coal mining operations contain
significant levels of hazardous materials that can
adversely impact the environment. The hazardous
materials are a result of the constituents, particularly
heavy metals, contained in the ores being processed.
Generally, the presence of hazardous materials is a
bigger problem with tailings than it is with mine waste
because (1) the concentrations of hazardous materials
are usually higher in tailings; (2) the fine grain size
of tailings increases the solubility of the materials
liv
-------
contained in the waste; (3) the fine grain size of
tailings increases the likelihood of wind and water
erosion; (4) the presence of processing reagents in
tailings creates a complex chemical environment that
complicates hazardous waste problems; (5) overburden is
often returned to the excavated area, where it is
protected from erosive forces.
The presence of pyrite in tailings significantly
increases the potential hazard because it results in
acidic conditions that increase the likelihood of the
leaching of the hazardous metals in the waste.
Quantitative data are not available concerning the
exact amount of tailings that produce acid drainage and
associated heavy metals problems, but best available
estimates indicate that 25 percent of the metallic
mineral industries generate sufficient pyrite to produce
acid waters containing hazardous levels of heavy metals,
21 3
and about 40 to 50 percent of the coal mines. '
The problem of hazardous materials in tailings is
increased when other industrial wastes are combined
with the tailings. Such combination produces a more
complex chemical environment and a waste with a
character entirely different from that of ordinary mine
or beneficiation wastes. Examples of other industrial
wastes that are added to tailings at some operations
Iv
-------
are effluents from refinery plants and fertilizer
processing operations and blowdown from sulfuric acid
plants. Although wastes are combined in several
different mining industries, the combining occurs most
frequently in the copper, lead, and zinc industries.
The extent of generation of combined wastes is not
known, but an estimate of 50 to 100 million tons (45 to
91 Gg) of such waste per year appears reasonable.*
Hazardous effects associated with tailings are
further complicated when these wastes contain potentially
toxic substances resulting from the use of certain
beneficiation reagents (e.g., sodium cyanide and copper
sulfate). These reagents are used in some copper,
lead, zinc, and gold and silver operations. Toxicity
problems can also result from carryover of organic
flotation reagents into tailings, although the extent
of this problem is uncertain at this time and more
analytical testing is needed to increase the
understanding of the effects of these reagents.
Research is currently being performed to develop
nonhazardous reagents.
5. The problem associated with uranium mining and
beneficiation operations is the discharge of significant
* PEDCo engineering estimate based on calculations made in
this study and literature values.
Ivi
-------
volumes of radioactive beneficiation wastes (8 million
tons or 7.2 Gg per year), which can result in the
release of airborne and waterborne radionuclides to the
environment. Moreover, the growing demand for uranium
as fuel in nuclear power plants is expected to more
than double its production by 1985 and this intensifies
the concern for the potential health and environmental
hazards associated with this industry. Uranium tailings
are generally disposed of by impounding them in unlined
ponds, and up to 50 percent of the liquid portion of
the tailings impounded may be lost by seepage, resulting
in subsequent pollution of groundwater. Lined ponds
represent a recent advance in state-of-the-art technology
for containment of tailings. Liners may be clay,
treated clay, or synthetic. The current trend is
toward synthetic liners because the acid waters typical
of most uranium tailings break down clay materials.
The proposed RCRA Regulations for Hazardous Wastes
(Federal Register, December 18, 1978) now regulate only
the overburden and waste rock from uranium mining
operations. Data on the environmental impact of these
mine wastes is limited, but compared with the threat
posed by beneficiation wastes, it is believed to be
much less significant.
PL 95-604, The Uranium Mill Tailings Radiation
Control Act of 1978 (November 8, 1978) has authorized
Ivii
-------
EPA to set health and environmental standards for these
wastes, to be regulated by the Nuclear Regulatory
Commission and "agreement states."
The real problem associated with the airborne
radionuclides from the phosphate mining industry is
apparently limited to reclaimed, inactive mining areas
where beneficiation and reclamation processes are no
longer practiced and radioactive materials are left
exposed. There appears to be no groundwater contamination
by radium 226 from active mining and beneficiation
operations.
Although the mineral resource wastes produced by the
mercury and beryllium industries contain some constituents
that could be considered potentially hazardous, these
wastes are not of significant concern because: (1)
only small amounts of solid wastes are produced by
these industries [less than 3 million tons (2.7 gegagrams)
per year] because of the small number of operations in
each industry (the beryllium industry consists of one
mine, and the mercury industry consists of less than
fifteen); (2). the climate and topography of the areas
where mercury and beryllium operations are located are
such that wind and water erosion of wastes is not a
problem; (3) there are no acid drainage problems
associated with either of these industries.
Some scientists and regulators have exhibited concern
about the release of asbestos fibers into the environment
Iviii
-------
as a result of some mining and beneficiating operations
[e.g.f the highly publicized Reserve Mining Company's
daily disposal of 67,000 tons (61 megagrams) of taconite
tailings containing asbestos fibers into Lake Superior].
Other industries that have received attention because
of the release of asbestos to the environment include
the direct mining of asbestos and selective operations
in the vermiculite, copper, gold, and talc mining
industries. The amount of mineral resource solid
wastes generated by these industries that may result in
the release of asbestos fibers to the environment is
estimated to be less than 5 million tons (4.5 gigagrams)
per year.* Based on air and water monitoring surveys
and some epidemiological studies, scientists have
concluded that no significant environmental impact
results from the mining and beneficiating of minerals
containing asbestos fibers.
8. Emissions of nonhazardous fugitive dust from dry,
inactive tailings ponds, especially those resulting from
high winds in the arid West and Southwest, can have a
significant impact on the immediate surrounding area;
however, the relative overall impact of these emissions
on regional air quality is insignificant compared with
other fugitive dust sources.
* PEDCo Engineering estimate based on calculations made in
this study and literature values.
lix
-------
9. With a few exceptions, adequate disposal, stabilization,
and control methods are available to protect human
health and the environment from the effects of mineral
resource wastes. Historically, widespread deficiencies
in the application of these methods have left vast
areas of mined lands exposed to natural forces of
erosion. Currently, and especially recently, industry
is accelerating the extent of application of these
methods; however, a significant amount of improvement
is still needed. In particular, problem areas where
these methodologies should receive increased application
include:
0 Control of mineral resource wastes that produce
acid water.
0 Reclamation of waste disposal areas located where
conditions are adverse (e.g., where climate,
topography, and soil characteristics are less than
favorable).
0 Reduction of the release of hazardous materials
(primarily radioactive agents from uranium mining
and berieficiation and heavy metals from the
metallic mineral and coal mining industries) to
surface and groundwaters via seepage and percolation.
10. Apparent gaps in current Federal environmental regulations
governing mineral resource wastes include:
0 Surface water regulations do not prohibit seepage
from ponds nor require monitoring to detect
possible contamination of aquifers.
0 Groundwater regulations do not take into account
regional differences in the quality of natural
groundwater.
0 Air quality regulations do not include coverage of
radioactive emissions.
Ix
-------
State regulations vary widely in their coverage; some
are up to date, whereas others are antiquated;
generally they are weak in the same areas delineated
for Federal regulations.
11. A major conclusion drawn from this study is that data
are generally sparse concerning mineral resource wastes
and that more information is needed to assess their
potential impact on human health and the environment.
Additional data should include more field and laboratory
testing to determine the types and quantities of
potentially harmful materials in wastes and how time
affects the interaction of these constituents in the
associated complex chemical environment of some mineral
resource wastes. Additional groundwater and surface
water monitoring data are also needed to determine the
amount of hazardous materials escaping from waste
disposal areas via seepage, percolation, and runoff.
Finally, more bioassay testing is needed to determine
lethal and sublethal concentrations of the hazardous
materials associated with mineral resource solid wastes.
Identification of Mineral Resource Solid Waste Problems by Industry
A priorities-ranking system has been developed in an effort
to identify the mining industries that have the greatest relative
impact on human health and the environment as a result of the
solid wastes they produce. Five criteria were chosen to judge
the potential adverse impacts (Table V). Each criterion was
Ixi
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TABLE V
RANKING OF POTENTIAL ENVIRONMENTAL
IMPACT BY MINERAL
Intanaity ol
1.
1.
Criteria* n
KM criteria
a. Naiardoua
b. Nonnaurdowi
Total quantity el Mineral reoourca
•attae
Priority ratine
(•aeed en Million tone per year)*
0
0
0
I'SI
10
16
10 .
It-lS)
'•pact
to
36
16
(2t-7S)
Major
106
SO
40
J. Number ol domeatic Binae
Priority rating
(Meed en total number el
4. Projected frowth/daclme el
induatry
Priority retine
all
0 10 . 10 40
11-10) (11-21) llt-106) l>100
1I77-1IISH
1-0-51
(t-lS)
114-401
1 -501
Matala
Baueite
Copper
Cold
Iron ore
Lead
Mercury
Molybdenum
Silver
Urania*
tine
Other'
iienmetala
Aabeatoa
Claye
Oiatoeute
reldapar
Gypauei
Mica lacrap)
Perlite
Phoaphata rock
Potaadum aalta
Pumice
tail
land and araval
Sodium carbonate
Stone
Cruahad and broaan
Oimenaion
Talc, aoapatone:. ' pyropfiylllte
Otnerl :
Mineral Puele
bitumineua. and ll«nite)
Hal
0
to
20
20
to
20
20
20
100
to
0
20
0
0
0
0
0
0
10
0
0
0
0
0
0
0
0
to
lib)
10
JO
10
JO
JO
0
10
10
JO
JO
6
0
10
0
0
10
0
JO
0
0
0
JO
0
10
0
0
0
so
1
10
40
10
40
10
0
10
0
40
10
10
0
10
0
0
10
0
0
40
10
0
0
10
10
10
0
0
10
46
J
10
20
20
20
20
10
0
10
40
10
0
0
46
16
10
10
10
10
10
0
40
10
40
0
40
40
10
0
40
4 Total acora
0
JO
JO
JO
IS
0
JO
IS
JO
IS
J6
JO
JO
)0
IS
s
s
s
JO
s
JO
JO
JO
10
JO
s
16
IS
IS
JO
110 '
• 0
140
115
JO
70
ts
140
us
46
SO
100
40
Jl
JS
*s
is
140
IS
70
40
110
40
100
4S
SO
IS
10S
• lee Appendta D for an explanation of UM criteria uW la tJua ta£la.
• Valvea ttaaad on data contained In Table 7 of tbll docwent.
I Valuea baaed on data contained in Table 2 of tnia decent.
t AntlKny. berylliu*. ea»«anifareua ore. •onetlta. nlclal. platlni*
froup vetala. rare earth aatala, tin. titanium, iiaanita. tuneitan. vanadluv.
f AMraei»ea. apllte. barite. boron einarala. fluorapar. erapnita.
freenaand aarl. iron o»de pievnta I crude), kyanite. lltbiu* unerala.
•afneaite. •illatonae. olivine. varmiculite.
Ixii
-------
weighted according to its relative importance, i.e., Criterion
l(a) carries the most importance and Criterion 4, the least.
Four arbitrary values are assigned to indicate the degree to
which that criterion applies to each industry. For example,
Criterion l(a) concerns hazardous wastes from mining and
beneficiation; if a specific industry generates an insignificant
amount of hazardous wastes, it receives a:.value of 0 for that
criterion; if hazardous wastes are a minor problem, the industry
receives a value of 20; if they are a major problem, it receives
a value of 100.
The values assigned to each criterion for a particular
industry are then totaled, thus providing a comparison for
determining which industries are likely to have the greater
impact on the environment.
Despite the quantitative "total score" ranking of each
mineral industry, however, the end result is at best a qualitative
ranking of industries. Thus, the listing cannot be interpreted
to mean the adverse environmental impact from uranium, for
instance, is six times greater than that from diatomite. In
fact, rankings for minerals such as diatomite are based exclusively
on criteria that measure the size and extent of an industry,
i.e., RCRA criteria (impact from hazardous and nonhazardous
wastes) are not involved, and these industries are actually
considered environmentally insignificant on the whole.
Although this priority ranking of individual mineral
industries is arrived at by a seemingly somewhat arbitrary
Ixiii
-------
process, it does reveal the major industries (e.g., uranium,
coal, copper, phosphate) that would be expected to have the
greatest adverse environmental and health impacts.
This listing and the discussion in this report should
provide background information needed to develop a long-term
strategy regarding the role of the Federal Government in the
control of industrial solid wastes.
Ixiv
-------
REFERENCES FOR EXECUTIVE SUMMARY
1. Office of Solid Waste Management Programs. A comprehensive
assessment of solid waste problems, practices, and needs.
Prepared by AD Hoc Group for Office of Science and
Technology, Executive Office of the President, Washington,
May 1969.
2. Peisse, F.H., D.W. Lockard, and A.E. Lindquist. Coal
surface mining reclamation cost in the western United
States. Bureau of Mines Information Circular IC8737.
Washington, U.S. Government Printing Office, 1977.
3. U.S. Bureau of Mines. Minerals yearbook, 1975 ed. (Preprint)
Washington, U.S. Government Printing Office, 1975.
4. Bel, L.C. 1977 Keystone coal industry manual. New York,
McGraw Hill Mining Publications, 1977.
5. Office of Water and Hazardous Materials. Inactive and
abandoned underground mines, water pollution prevention
and control. U.S. EPA Publication 440/9-75-007.
Washington, 1975.
6. Paone, J., J.L. Morning, and L. Giorgetti. Land utilization
and reclamation in the mining industry, 1930-71. U.S.
Bureau of Mines Information Circular IC8642. Washington,
U.S. Government Printing Office, 1974.
7. Offices of Research and Development. Availability of mining
wastes and their potential for use as highway material.
v. 1, 2, and 3. Federal Highway Administration Report
No. FGWA-RD-76 106. Washington, 1976.
8. Office of Research and Development. Vegetative stabilization
of mineral waste heaps. U.S. EPA Publication 600/2-76-087.
Washington, U.S. Government Printing Office, 1976.
9. Mining Enforcement and Safety Administration. Mine refuse
impoundments in the United States. MESA Informational
Report 1028. January 1977.
10. Dean, K.C., and R. Havens. Methods and Costs for Stabilizing
Tailings Ponds. Presented at the American Mining
Congress Mining Convention/Environment Show, Denver,
Colorado, September 9-12, 1973.
11. Office of Research and Development. Water pollution caused
by inactive ore and mineral mines, a national assessment.
U.S. EPA Publication 600/2-76-298. Washington, U.S.
Government Printing Office, 1976.
Ixv
-------
12. Volpe, R.L. Geotechnical Engineering Aspects of Copper
Tai ngs Dams. Presented at the American Society of
Civil Engineers National Convention, Denver, Colorado,
November 3--7, 1975.
13. Midwest Research Institute. A study of waste generation,
treatment, and disposal in the metals mining industry,
for Environmental Protection Agency, Solid Waste Management
Division, Washington, PB-261052, October 1976.
14. Williams, R.E. Waste production and disposal in mining,
milling, and metallurgical industries. San Francisco,
Miller Freeman Publication, Inc., 1975. 489 p.
15. Personal communication. R.E. Williams, professor of
hydrogeology, University of Idaho, to J. Greber, PEDCo.
May 30, 1978.
16. Personal communication. J. Bowen, Erie Mining Company, to
R. Amick during PEDCo visit to Hoyt Lakes, Minnesota, iron
ore mining operations, January 30, 1978.
17. Spendlove, J.J. Bureau of Mines research on resource
recovery, reclamation, utilization, disposal, and
stabilization. Information Circular 8750, 1977.
18. Mead, W.E., and G.W. Condrat. Groundwater Protection and
Tailings Disposal. Presented at the American Society of
Civil Engineers National Convention, Denver, Colorado,
November 3-7, 1975.
19. Kealy, C.D.,, and R.E. Williams. Flow through a tailings pond
embankment. Water Resources, 7(1), 143-154, July 1971.
20. Collins, R.J., and R.H. Miller. Availability of mining
wastes and their potential use as highway material, v. 1.
Classification and technical environmental analysis,
prepared for Federal Highway Administrator Offices of
Research and Development. Report No. FHWA-RD-76 106
by Valley Forge Laboratories, May 1976.
21. Personal communication. Selected experts in various state
and Federal agencies to Dr. Roy E. Williams, professor of
hydrogeology, University of Idaho. August 1978.
Ixvi
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SECTION 1
INTRODUCTION
Since its origin, the U.S. mining industry [considered here
to encompass the recovery of all types of ores (metallic,
nonmetallic, and solid mineral fuels)] is estimated to have
generated more than 30 billion tons (27.2 Pg) of solid wastes as
a result of developing, extracting, and processing (beneficiating)
activities. Recently, the rate of generation has increased
rapidly because larger, more efficient mining machines are used
and more ore, deeper orebodies, and lower grade ores are mined to
meet the increased demand for minerals. The current rate,
estimated to be approximately 2.3 billion tons (2.1 Pg) per year
and second only to agricultural wastes in magnitude, accounts for
about 40 percent of the total solid wastes generated annually in
the United States. This is more than twice the amount generated
by the mining industry in 1967.
The task of contending with mineral resource solid wastes
already generated and those being generated is a serious one, but
it is likely to be even more difficult in the future as the
industry is forced to mine deeper and even lower grade orebodies.
By 1985 the Nation's mining industries are expected to generate
about 4 billion tons (3.6 Pg) of solid waste annually, and by
2000 the annual figure is projected to reach 6 billion tons
-------
(5.4 Pg). Should ocean and oil shale mining become major
commercial enterprises (as expected), these quantities could
double.
Problems associated with the handling and ultimate disposal
of mineral resource solid wastes multiply as quantities increase.
For example, failure of waste impoundments have caused disasters,
harmful materials have contaminated surface and groundwaters and
the atmosphere, and in some cases negligence on the part of mine
operators has jeopardized the public and the environment.
Although many mineral resource solid wastes are inert, some
can be harmful, particularly those containing heavy metals,
radioactive constituents, or acid-forming minerals (primarily
pyrite).
Having recently concluded that information regarding
potential dangers posed by mineral resource solid wastes is not
sufficient to form the basis for legislative action at this time,
Congress mandated a study of these wastes under the authority of
Section 8002(f) of P.L. 94-580, the Resource Conservation and
Recovery Act of 1976 (RCRA), and directed the U.S. Environmental
Protection Agency to conduct this study.*
The scope and objective of the study are described in the
following excerpt from Section 8002(f), MINING WASTE:
* By way of clarification, in 1977 Congress concluded that
sufficient information was available to form the basis of
legislation for the coal industry and passed the Surface Mining
Control and Reclamation Act (SMCRA). Although SMCRA now applies
only to the coal industry, it could eventually affect other
mineral mining industries as well.
-------
"The Administrator, in consultation with the Secretary of
the Interior, shall conduct a detailed and comprehensive
study on the adverse effects of solid wastes from active and
abandoned surface and underground mines on the environment,
including, but not limited to, the effects of such wastes on
humans, water, air, health, welfare, and natural resources,
and on the adequacy of means and measures currently employed
by the mining industry, Government agencies, and others to
dispose of and utilize such solid wastes and to prevent or
substantially mitigate such adverse effects. Such study
shall include an analysis of -
(1) the sources and volume of discarded material
generated per year from mining;
(2) present disposal practices;
(3) potential dangers to human health and the
environment from surface runoff of leachate and air
pollution by dust;
(4) alternatives to current disposal methods;
(5) the cost of those alternatives in terms of
the impact on mine product costs; and
(6) potential for use of discarded material as a
secondary source of the mine product.
In furtherance of this study, the Administrator shall, as he
deems appropriate, review studies and other actions of other
Federal agencies concerning such wastes with a view toward
avoiding duplication of effort and the need to expedite such
study. The Administrator shall publish a report of such
study and shall include appropriate findings and
recommendations for Federal and non-Federal actions
concerning such effects."
This report is in response to the study outlined above. It
is based on published and unpublished data and information
acquired during visits to selected mine sites; no sampling tests
were conducted in the field. Particular emphasis is placed on
the question of whether the disposal of mineral resource wastes
should be further regulated; if so, how; if not, why not. It is
important to note that this study does not provide recommendations
for such regulation; rather, it provides data for use by those
who will make these recommendations.
-------
This investigation could result in the EPA recommending one
of the following courses of action:
(1) Mineral resource solid wastes should not be regulated
further because they are being properly handled and
disposed of at this time under existing Federal,
state, and/or local regulations.
(2) The handling and disposal of mineral resource solid
wastes are not being properly regulated at this time;
therefore the appropriate sections of the Resource
Conservation and Recovery Act should be applied to
assure the proper regulation of these wastes.
(3) The handling and disposal of mineral resource solid
wastes are not being properly regulated at this time;
additional regulation is needed, but the Resource
Conservation and Recovery Act is not the proper vehicle
to use to impose these regulations.
(4) The information available is not sufficient to make a
decision concerning the regulation of mine solid
wastes; therefore additional studies are needed before
a decision can be made.
In this investigation solid wastes are considered to be
those wastes from mining (surface and underground) and
beneficiation (e.g., crushing, screening, and concentrating),
including leaching. Wastes from roasting, smelting, refining,
and other chemical processing are not included, although
occasionally these wastes are discarded in tailings ponds and
thereby constitute a primary source of hazardous materials in the
pond.
In this study mineral resource solid wastes are separated
into three categories: (1) mine wastes, (2) beneficiation wastes,
(3) miscellaneous wastes. Mine wastes consist of unwanted
materials removed during ore extraction. Beneficiation wastes
consist of discarded materials removed during ore processing.
-------
Miscellaneous wastes consist of minor wastes such as site
preparation wastes (e.g., drilling muds and removed vegetation),
construction wastes (e.g., scrap iron and wood), damaged or used
reagent or product containers, domestic sewage sludges, and
residuals from pollution control equipment. Because miscellaneous
wastes are minor in volume and importance compared with mine and
beneficiation wastes/ little attention is given to them in this
study.
There is some question as to which, if any, mineral resource
solid wastes are actually covered by RCRA. The following
exceptions stated in the act would seem to eliminate at least
some of them:
(1) Industrial discharges, which are point sources subject
to NPDES permits (Subtitle A, Section 1004, parenthesis
27).
(2) Source, special nuclear, or byproduct material as
defined by the Atomic Energy Act of 1954, as amended
(Subtitle A, Section 1004, parenthesis 27).
This investigation addresses all mineral resource solid '
wastes associated with the extraction and beneficiation of
metallic ores, nonmetallic ores, and solid mineral fuels (coal),*
even though some of these wastes may eventually be exempted from
* Coal is the only solid mineral fuel actually addressed in
this study. Uranium was addressed under the metallic ores
category. Oil shale, which is a solid mineral fuel, has not
been specifically addressed in this study; however, the report
does refer to the fact that the expected expansion of this
industry could substantially increase the annual production of
mine solid waste.
-------
coverage by RCRA. The decision not to exclude the wastes that
qualify as exemptions is based on our interpretation of Section
8002(f) of RCRA and the legislative history of the act. That
section 8002(f) does not refer to any specific exemptions covering
mineral resource solid wastes was interpreted to mean that all
mineral resource solid wastes as they are typically defined
(e.g., overburden, underground mine development waste rock,
tailings) should be addressed. Although the legislative history
of RCRA is supportive of the exemptions referred to above, the
history of the act indicates that the exemptions are not final as
stated in the House Report on H.R. 14496.* H.R. 14496 states
that
"... overburden resulting from mining operations and
intended for return to the mine site is not considered to be
discarded material within the meaning of this legislation.
This however does not preclude any finding by the
Administrator that specific mine wastes are hazardous wastes
within the scope of this legislation. Nor does this preclude
consideration of mine waste as discarded material sometime
in the future."
Estimates indicate that large volumes of mine solid wastes
have accumulated at both active and inactive mining sites. If
not properly disposed of and stabilized, these wastes can pose a
threat to human life and the environment. Because estimates of
accumulated solid wastes are based on annual production statistics,
they do not represent the actual amount of waste that has been
deposited in mine waste heaps and tailings ponds. In other
* H.R. 14496 is the House bill that, together with S. 3622,
formed the basis for the legislation that was ultimately enacted,
-------
words, all of the wastes generated are not placed in waste heaps
or tailings ponds, where they remain untouched for an indefinite
period of time.
Following are some of the factors that reduce the amount of
mineral solid wastes that accumulate in mine waste heaps and
tailings ponds:
0 Some of the wastes generated at underground mines
remain underground to fill in mined-out areas.
0 At some surface mining operations overburden is used as
mine backfill.
0 At some underground mines a portion of the tailings
(sometimes as much as 50 percent) is backfilled into
mined-out areas.
0 Mine and tailings wastes are sometimes used in onsite
road and dam construction.
0 Some wastes are reprocessed for their mineral values,
thus reducing the initial amount to be disposed of.
The disposal areas at most active mining operations will
eventually be rehabilitated or reclaimed to some degree. In some
states the amount of land mine operators are reclaiming annually
actually exceeds the amount disturbed. Some operators are
reclaiming lands affected by mining activities before passage of
surface mining and reclamation legislation. Despite these
positive aspects, however, mineral resource solid wastes still
pose a threat to the environment for the following reasons: (1)
because little was done before the late sixties to control and
rehabilitate waste disposal areas, large amounts of unstabilized
wastes had already accumulated; (2) often there is no one to
assume responsibility for the large quantities of waste materials
-------
at the numerous inactive mining sites; (3) although some wastes
at active mines may eventually be stabilized and reclaimed, they
can pose a threat to the environment until such action is taken;
(4) because of poor reclamation techniques and a lack of
maintenance programs, some reclaimed lands may ultimately revert
to unreclaimed condition.
The approach to this project was to acquire, compile, and
analyze as much available information as possible given the time
constraints and broad scope (all mining industries) of the study,
and to use this information in the data base report that formed
the basis for the technical study and document. The data
gathering consisted of four major tasks, each concerned with a
particular information source.
The first task was to perform a literature search for
information (published and unpublished) dealing with the
generation, control, regulation, and environmental effects of
mineral resource solid wastes. It involved conducting several
computerized searches (e.g., NTIS, MEDLINE, TOXLINE) and
contacting a number of public, academic, and governmental
libraries. All the material gathered was reviewed for content
and recorded on standard PEDCo literature survey forms.
The second task was to contact various governmental agencies
whose realm of responsibility includes the mining industry and/or
effects of the industry. The contacts were initiated through
letters and telephone conversations, normally followed by meetings,
-------
Information was obtained in the form of documentation (published
and unpublished) and personal communications. Appendix A lists
the agencies and personnel contacted.
The third task was to contact various trade associations
that could provide industry contacts, furnish answers to both
general and specific questions, and help arrange mine site visits,
The following trade associations were contacted:
American Mining Congress (AMC), Washington
0 Jim Walpole, Legal Counsel
Arizona Mining Association (AMA), Phoenix
0 E. J. Johnson
Northwest Mining Association (NWMA), Spokane
0 Carl Mote, Executive Director
Colorado Mining Association, Denver
0 Dave Cole, Executive Director
China Clay Association, Atlanta
0 Chris Haggy, Senior Legal Counsel
National Coal Association/Bituminous Coal Research
(NCA/BCR) Coal Conference in Louisville
The final task was to visit mine sites to obtain specific
operational and solid waste data and to solicit opinions and
input from mining personnel regarding the issues of this project.
(The mining trade associations arranged most visits.) The
following mine sites (listed by industry) were visited:
-------
Iron ore
Erie Mining Company, Hoyt Lakes, Minnesota
Coal
Consolidation Coal Company, Pittsburgh, Pennsylvania
Colowyo (W.R. Grace and Company), Craig, Colorado
Energy Fuels Corporation, Steamboat Springs, Colorado
Clay
Freeport Kaolin Company, Gordon, Georgia
Engelhard, Mclntyre, Georgia
J.M Huber Corporation, Huber, Georgia
Phosphate
International Mineral Corporation, Bartow, Florida
Agrico Chemical Company, Bartow, Florida
Uranium
Union Carbide Corporation, Uravan, Colorado
Union Carbide Corporation, Rifle, Colorado
Western Nuclear, Inc., Wellpinit, Washington
Dawn Mining Company, Spokane, Washington
Copper
Duval Sierrita Corporation, Tucson, Arizona
Cyprus Pima, Tucson, Arizona
Magma Copper Company, Tucson, Arizona
Lead-Zinc-Silver
Hecla Mining Company, Wallace, Idaho
Molybdenum
Climax Molybdenum Company (AMAX, Inc.)/ Climax, Colorado
Climax Molybdenum Company (AMAX, Inc.), Leadville, Colorado
Environmental Services, Inc. (AMAX, Inc.), Denver, Colorado
The report covers five major topics, each covered in a
separate section. Section 2 characterizes the mining industry
according to various factors such as kinds and quantities of ores
mined, geographic location of various mining industries, and
mining and beneficiation methods currently in use. Section 3
describes the sources, quantities, and characteristics of mineral
resource solid wastes. Section 4 assesses and evaluates solid
waste disposal and stabilization technologies now used by the
10
-------
mining industry. Section 5 presents an environmental assessment
of the direct effects of mine solid waste and the resultant or
indirect effects of these wastes on human life and the environment,
Section 6 evaluates the results of the survey concerning the
regulation of the disposal and management of mineral resource
solid wastes by existing and pending Federal, state, and local
legislation.
Section 7 discusses the major potential environmental
problems associated with mineral resource solid wastes. The
information contained therein is based partially on the criteria
presented in the hazardous and nonhazardous pollutant sections
of the proposed RCRA regulations.
English units followed by International System of Units (SI)
(Mechthy 1969) units in parentheses are used throughout the text.
English units only are used on tables and figures, and the reader
is referred to a metric conversion table in the front matter.
Basic SI units, derived SI units, and SI prefixes are also
presented there for the reader's convenience.
11
-------
SECTION 2
INDUSTRY PROFILE
An assessment of the adverse effects of solid waste generated
by the U.S. mining industry should begin with a description of
the nature and extent of the industry. The nature of the
industry is described in terms of kinds of ore and ore complexes
mined, byproduct/coproduct relationships, and current typical
extraction and beneficiation methods. The extent of the industry
is defined in terms of number of active and inactive mines, their
geographic distribution, and present and projected production
statistics (including a comparison of the amount of ore recovered
from surface and underground mines).
The ores covered in this document can be separated into
three main categories: metals, nonmetals, and solid mineral
fuels. The metals category can be subdivided into ferrous and
nonferrous metals. Ores and ore complexes belonging to each
category are extracted from U.S. mines.
The domestic ores extracted range from unconsolidated
surface (placer) deposits to ore bodies located deep underground.
Many deposits, especially in the nonmetal and solid mineral fuel
categories, are mined to recover a single mineral commodity;
whereas other deposits (ore complexes) are mined to recover a
primary mineral and its associated coproducts or byproducts. The
12
-------
value of these associate minerals sometimes makes it economically
feasible to recover an otherwise unprofitable mineral deposit.
Most of these coproducts and byproducts are associated with
metallic ores.
•
Ore extraction methods vary with the kind of ore and its
physical surroundings. Both surface mining and underground
mining are practiced in the United States. Surface mining, an
open-air method of extraction, includes placer, strip, open pit,
and quarry mines and some variations and combinations thereof.
Underground methods include room-and-pillar, stope, block caving,
and longwall mining and some variations of these.
Beneficiation (ore processing) varies with each commodity.
It ranges from size reduction and classification of construction
material ores to complex grinding and flotation of metal ores.
The quantity of solid waste generated by the mining industry
relates directly to the quantity of material handled and the
quantity of salable product. Because the most recent quantitative
data on crude ore production were published in 1975, it was
necessary to estimate the amount of crude ore mined and processed
for various commodities in 1977. Production quantities were also
projected for 1985 and 2000 as a basis for estimating the amount
of mining wastes that will be produced in those years.
Nature of the Mining Industry
Ores and Ore Complexes. Descriptions of the four
classifications of domestic ores are as follows:
13
-------
Ferrous Metals. Ferrous metals include iron and those
metals that can be alloyed with iron to produce various iron
products, steel, and superalloys. Domestically mined metals in
this group are iron, molybdenum, nickel, tungsten, and vanadium.
Rhenium, also a ferrous metal, is produced as a byproduct during
the roasting of molybdenite concentrate obtained from domestic
porphyry copper ores.
Much of the domestic ferrous metal demand is met by imports,
primarily because of geographic relationships between domestic
sources and the consumer and cost-quality demands. Essentially
all of the nickel and a third of the iron ore requirements are
met by imports. Other ferrous metals supplied primarily by
imports are chromium, cobalt, columbium, manganese, and tantalum.
Domestic demand for ferrous metals by the construction and
transportation industries, which are the major consumers of these
metals, calls for high-quality products. The major emphasis in
coming years will involve improving product quality and perhaps
finding suitable substitutions for the less abundant metals.
Nonferrous Metals. Many nonferrous metals occur in
association with the same ore. For example, some complex copper
ores yield selenium, tellurium, gold, silver, and other nonferrous
metals as well as copper. Among nonferrous metals that are not
mined in the United States for their exclusive economic value are
bismuth, cadmium, gallium, germanium, hafnium, indium, selenium,
tellurium, and thallium. These ores are captured during the
refining or smelting of more economically attractive ores like
copper or zinc.
14
-------
Nonferrous metals that are extracted from domestic mines
include: antimony, aluminum, copper, gold, lead, mercury, rare
earths, silver, tin, titanium, uranium, and zinc.
Several other nonferrous metals (arsenic, cesium,
platinum-group metals, radium, rubidium, and scandium) are not
recovered from domestic ores; they either are imported in
finished or semifinished form or are produced from imported raw
ores.
Nonferrous metals are used primarily in consumer goods, in
the transportation and construction industries, and in electrical
components. Both the demand for and the value of these metals
are expected to increase. Output could be increased and cost
decreased through the development of improved mining and
processing methods that would make possible the use of submarginal
domestic ores.
Nonmetals. Although nonmetals usually are mined as the only
recoverable constituent of an ore, some coproducts and byproducts
are associated with these ores. The following nonmetals are
extracted from domestic mines:
asbestos graphite potash
barite gypsum salt
bentonite lightweight aggregates sand and gravel
boron limestone soda ash
clay mica stone
diatomite peat talc, soapstone,
feldspar perlite pyrophyllite
garnet phosphate rock
These nonmetallic minerals are used by a variety of
industries. In decreasing order of consumption the major ones
are construction, agriculture, metal working, industrial chemicals,
15
-------
and plastics and fibers. New construction, renovations, and the
improved standard of living of a growing population are likely to
sustain the high demand for these minerals. Domestic sources of
nonmetallic commodities are expected to be adequate to meet the
demand.
Solid Mineral Fuels. The only solid mineral fuels of
concern in this report are anthracite, bituminous, and lignite
coals. The demand and production of anthracite coal are expected
to remain fairly constant until 1980, at which time electric
utilities could increase their demand for this fuel. Demand and
production of bituminous and lignite coals are expected to
increase continuously through the year 2000.
Mining Activities. Mining activities encompass prospecting
and exploring for a mineral deposit through finding, proving,
developing, extracting, and processing the ore. These activities
can be divided into three major phases: Phase I, Premining;
Phase II, Mining; Phase III, Postmining (Figure 1).
An additional phase of the mining operation is the
reclamation of the mine site and other affected areas. Because
the term "mined-land reclamation" has been used indiscriminately
to refer to anything from seeding to restoring the mined land to
its original condition, the term "reclaimed" has little meaning
in the context of mine wastes. As currently used, the term
"mined-land reclamation" refers to returning the disturbed land
to a condition and/or use equal to or higher than that prior to
mining. Reclamation is usually conducted simultaneously with
16
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PHASE I |
PREMINING i
•
PHASE II
MINING
J PHASE III
| POSTMINING
FINDING
PROVING
PLANNING
OPENING AND
DEVELOPING
EXTRACTION
SURFACE
UNDERGROUND
DREDGING
ORE TO
PROCESSING
PROCESSING
TO FURTHER PROCESSING
OR CONSUMER PRODUCTS
TRANSPORTING
UNLOADING
CONCENTRATING
DEWATERING
THERMAL DRYING
LEACHING
DRILLING r^V:.- SIZE REDUCTION
SAMPLING
SHAFTING AND/OR TUNNELING
SELECTION OF OPERATING METHODS
DESIGN AND ENGINEERING
SHAFT SINKING AND TUNNELING
CLEARING AND GRUBBING
STRIPPING
UNDERGROUND AND SURFACE
CONSTRUCTION
Figure 1. The scope of mining activities can be divided into
three major phases.
Source: Given, I.A., ed. SME mining handbook. v. 1. New York,
Society of Mining Engineers of the American Institute of
Mining, Metallurgical, and Petroleum Engineers, Inc., 1973
-------
the operation phases of extraction and beneficiation in present
mining operations. Reclamation practices are discussed in detail
in Section 4 of this report.
Premining Activities. Phase I activities involve prospecting
and exploration to locate, characterize, and prove a potential
ore body.
Prospecting usually includes ground and geochemical
reconnaissance, examination of aerial photographs, and sometimes,
sampling and drilling. (Most modern prospecting activities leave
the ground relatively undisturbed.)
If the results of prospecting are favorable, exploration
activities are begun. The following is a list of some of the
methods used:
(1) Geological method—a study of the geology of an
ore deposit and its general setting. Involves
geologic mapping and plotting by the use of such
tools as a transit, stadia, compass, and tape.
(2) Geochemical method—a study of the chemistry of
rocks, soils, waters, and the atmosphere.
(3) Biochemical method—a study of plant material to
determine trace metal content.
(4) Geophysical method--a study of the physical
characteristics of rocks and minerals. The six
basic geophysical exploration methods commonly
employed are gravity, seismic, magnetic,
electromagnetic, electric, and radiometric.
The physical work involved in exploration usually includes
trenching, pitting, and drilling. Generally trenches and pits
are dug with bulldozers, backhoes, mechanical or hydraulic
rippers, and septic tank diggers. Drilling equipment ranges in
size and complexity from simple hand-operated augers to
18
-------
small-scale oil-field rigs. Exploration drilling is used to
study the ore itself and the thickness and characteristics of the
overburden.
Results of the exploration study are used to locate and
characterize (prove) the ore deposit. Data obtained from
exploration studies may also be of value in planning extraction
and hauling facilities, developing beneficiation operations, and
establishing waste handling and disposal methods.
Once the shape and size of an ore deposit, its general
geological characteristics, its average grade, etc., have been
established, site development begins. Such development depends
largely on the kind of ore body and the mining method to be
applied. Activities during mine development include development
drilling, access road construction, clearing and grubbing,
adit or shaft development, overburden removal, establishment of
utilities and communication, and construction of beneficiation
facilities and general offices. Required equipment ranges from
small, simple units such as backhoes and dump trucks to
sophisticated systems involving earth movers, draglines, and
power shovels.
Although efforts are made to develop mine sites in harmony
with the environment, some alteration and disturbance of the
topography are unavoidable. Frequently an Environmental Impact
Statement (EIS) is required, either during the development stage
or just before. The EIS involves a detailed study of soil,
water, and air in the vicinity of the site and the potential
19
-------
impacts of acqess roads and other developmental features.
Generally, activities are halted (often for a year or more) while
the study is conducted. Considerably more detail may be required
if Federal land is involved, but an environmental impact study is
almost always a part of the premining operations. Further, many
states (e.g., Montana, North Dakota, Utah, Wisconsin, Pennsylvania,
Colorado, West Virginia, New York, Wyoming, and Illinois) require
the posting of a bond by a mining company during the development
stage. These bonds, which can be substantial, are designed to
insure that funds will be available for reclamation at the
appropriate time.
Mining Activities. Phase II activities involve either
surface or underground mining techniques. Although these
extraction methods are inherently different, some operations are
common to both (e.g., loosening the ore to allow removal and
loading and transporting the ore).
Although some mineral deposits can be removed by power
equipment such as front-end loaders, draglines, and dredges,
most must first be loosened by drilling and blasting. Drilling
consists of boring blast holes into the bedded minerals, usually
with tractor- or truck-mounted pneumatic rotary or percussion
drills. Blasting is then used to displace the minerals from
their deposits and to fragment them into sizes that require
minimum secondary breakage and are easily handled by loading and
hauling equipment. Once engineered, blasting practices consist
simply of loading blast holes with a predetermined amount of
20
-------
explosives, stemming, and detonating. Blasting frequency ranges
from several shots per day to one per week, depending on the mine
capacity and the size of individual shots.
Minerals are also broken out of a body of rock by hydraulic
jets. This method can also provide immediate transportation of
the materials. Rate of removal depends on the host material, the
grade of the opening (if underground), and groundwater flow. It
can be employed underground in either flat or vertical veins;
however, additional water is required to flush out the mined
material in a flat vein. Hydraulic mining has been used in
placer mining, especially for gold. Its current use is limited.
Normally, shovels and front-end loaders are used to
excavate and load broken minerals. At most surface mines,
haulage vehicles with a capacity of 20 to 150 tons (18 to 136 Mg)
are used to transport minerals from the mine to the beneficiation
facility, although off-the-highway vehicles capable of handling
350 tons (318 Mg) are also in use. At underground mines,
conveyors or haulage trucks are used to convey the crude ore to a
"skip," which transports it to the surface.
Underground Mining. An underground mine is a facility
constructed to permit the extraction and removal of a mineral
from a natural deposit beneath the earth's surface. The area of
land covering these extraction and removal activities and any
land surfaces disturbed by these.activities are considered to be
part of the mine. In some cases, a mine may also encompass areas
affected by ancillary surface operations, e.g., haul roads or
21
-------
access roads, truck haulage systems, workings, impoundments,
dams, ventilation shafts, drainage tunnels, entryways, solid
waste disposal areas, holes or depressions, repair areas, storage
2
areas, and structures.
The choice of an underground mining method depends on a
2
number of factors.
1. The quality, size, geometry, and depth of the ore
deposit.
2. The amount and distribution of the minerals in the
deposit.
3. The physical and chemical properties of the ore and the
parent rock.
4. The economics of the mining operation.
5. Special considerations (e.g., ecological, social, and
safety).
Some of the more common methods of underground extraction
are described in the following paragraphs.
In room-and-pillar mining, all of an ore stratum is removed
except occasional columns or pillars, which are left to provide
support for the overlying rock strata. This method is common
where ores are flat-lying or in gently dipping beds (Figure 2).
When the rooms are mined out, supports may be left in place or
removed (or partially removed) for their mineral value. The
structure of some areas is such that the pillars must be left in
place to prevent subsidence and its disturbance of the land
surface. The pillars are left in place in a regular pattern
during the mining operation. If they are to be removed, those
farthest from the haulage exits are mined out first, allowing the
roof to cave.in.
22
-------
-HAUL-DUMP MACHINE
PROPOSED PILLAR
Figure 2. Room-and-pillar mining is the most
common underground method used in the United States.
Source: Colorado Mining Association. Anatomy of a
mine—from prospect to production. Denver,
1975.
23
-------
Room-and-pillar mining is well adapted to mechanization, and
many different types of ore deposits are mined by this method.
It is the most common underground mining method used in the
United States from the standpoint of total production tonnage.
More than 75 percent of the underground mines producing 1200 tons
(1.1 Gg) or more per day use this method. Recovery of ores
varies from 35 percent at depths below 3000 ft (914 m) to more
than 90 percent at shallow depths if the pillars are recovered.
In open-stope mining, small ore bodies are mined out
completely and no pillars are left to support the walls. In some
varieties of rock it is possible to mine out huge stopes, which
may remain open for years (Figure 3). If the ore is low grade,
some of it is left in place (as random pillars) to support the
walls. Sometimes these pillars .are "robbed" just before a
portion of the mine is abandoned so that the collapse of the
stope walls will not affect the operation.
Sometimes the stoping method can be used to mine narrow
veins by placing an occasional wooden beam across the stope to
support the vein walls. This is called stull stoping (Figure 4).
In shrinkage stoping, the ore deposit is stoped from beneath,
allowing the broken ore to support the stope walls (Figure 5).
This method is used primarily in steeply dipping vein deposits,
where the walls and mineral body require little or no support.
Enough space is left above the broken ore for a miner to stand
and drill overhead, and broken ore is drawn off as needed to
maintain this headroom. After the stoping is completed, all the
broken ore is removed and the walls are allowed to collapse.
24
-------
SECTION A-A
B'
PLAN
SECTION B-B1
Figure 3. In open-stope mining, no pillars
are left to support the walls.
Source: Colorado Mining Association. Anatomy of a mine.
25
-------
STORE SUBDRIFT
ELEVATION
LACED MANWAYS
AND CHUTES
RAISE CUMBER
CUT OUT
SUNSHINE MINE
ALIMAK RAISING
Figure 4. Stull stoping can be used to mine
narrow veins.
Source: Wilhelm, G.L. A description of mining
practices in U.S. deep-vein silver mines.
Colorado Mining Association. 1974. Mining
Yearbook.
26
-------
PftWMlOT^
liiiw
K.Vici.VlltalU.|»V a)V?'•* ".'•...W i.>J
n III «jur '•"U
_. .,„.,., -,„,..,.,, , „,, ,..,,„ w.,-..a..RaagfiaBpAjft;i., ..„,„„,„,,.,,,,„
Figure 5. In shrinkage stoping, the ore deposit
is stbped from beneath.
Source: Colorado Mining Association. Anatomy of a mine.
27
-------
Other variations of stoping include cut-and-fill stoping
(used in wider, irregular ore bodies), rill stoping, hydraulic
4
filling, and square-set stoping.
The block caving method is used to mine large ore bodies
covered by barren or low-grade capping that is too thick to strip
away. A series of evenly spaced crosscuts are made below the
bottom of the ore to be caved, from which raises are driven up to
the ore. The entire ore body is then undercut so that it will
slowly cave into the raises (Figure 6). The ore's own weight
provides enough force to break it up and move it downward, where
it is drawn from beneath, trammed to the shaft, and hoisted or
hauled to the surface. As the broken ore is removed, the
overburden descends until fragments eventually appear in the
raises, indicating that the ore body is mined out. This type of
mining often leaves behind a surface depression (caused by the
sinking overburden material). These surface depressions can
become sources of groundwater recharge to the mine, which
ultimately may produce acid mine drainage at the portal.
In longwall coal mining, coal seams are removed in one
operation along a continuous face, sometimes several hundred
yards long. The coal is cut by plows or shearers that move along
the face. Shield supports provide an all steel roof running the
length of the face, which is moved as the face advances.
Recovery of as much as 90 percent of the coal is possible, and 70
to 80 percent is common on 500-ft (152-m) faces; this compares
with 55 percent recovery in average room-and-pillar mines.
28
-------
SURFACE
// ' '
/////////'s////
ALL ORE WITHDRAWN
'/.
Figure 6. The block caving method is used to mine
large ore bodies covered by barren or low-grade capping that
is too thick to strip away.
Source: Colorado Mining Association. Anatomy of a mine.
29
-------
Longwall mining, which is used widely in Europe, has been
gaining acceptance in the United States since the first face was
installed in 1960. Projections indicate that the 4 percent (of
total) underground production contributed by longwall mining in
1975 will increase to 15 percent by 1985 and possibly match the
contribution of continuous mining by the year 2000. Three major
factors have contributed to increased usage of longwall mining in
the United States: (1) high productivity, (2) health and safety,
(3) increased recovery of coal. Surface subsidence is also more
predictable than with room-and-pillar mining.
Surface Mining. Surface mining is an open-air method of
extracting metals, nonmetals, and solid mineral fuels. This
method can be used to recover minerals in any kind of rock as
2
long as overburden removal is not prohibitively expensive.
Surface mining is used to recover coal; copper, iron, and
aluminum ores; placer deposits of gold, tin, and platinum; and
sand, gravel, stone, gypsum, and clays among others. The
largeness and efficiency of recently developed earth-moving
machinery and auxiliary equipment used in this method make it
possible to recover many ore deposits that could not be
economically mined underground.
In general, surface mining operations entail removal of the
overburden covering the deposit, extraction of the mineral, and
transport of the mineral to the beneficiation site.
The four basic categories of surface mining—placer mining,
strip mining, open pit mining, and quarrying—are described in
the following paragraphs.
30
-------
Placer mining is used to recover heavy minerals from
unconsolidated surface deposits. Gold, tin, platinum, diamonds,
and various industrial metallic minerals such as zircon, ilmenite,
and rutile are recovered in this manner.
The two primary techniques used in placer mining are
hydraulic mining and dredging. In hydraulic mining, pressurized
water is directed at the deposit, usually a mineral bearing
gravel or sand, to disintegrate the gravel and wash the material
through sluice boxes. In dredging, a water-based floating
operation is used to raise mineral-bearing silt, sand, gravel,
etc., in a scoop or by suction.
Strip mining, the term commonly used to describe the method
used to surface-mine coal, generally falls into two categories:
area stripping, the method used when terrain is relatively flat
and coal seams are roughly parallel to the surface; and contour
stripping, which is used when terrain is hilly.
Area stripping begins with digging a trench through the
overburden. The material removed from this initial trench is
placed on adjacent undisturbed land, and the exposed coal is
removed by power shovels and front-end loaders. As each
successive cut is made parallel to the initial trench, the
overburden is placed in the preceding cut (Figure 7). The
distance from the first trench to the final one is often a mile
(1.6 km) or more, and the area between is covered with ridges of
overburden that must eventually be reclaimed. The land also must
31
-------
OR 161 NAT GROUND
SURFACE .
--- -
MINERAL SEAM
Figure 7. Area strip mining is performed by digging
successive trenches and refilling each as the next one is
dug.
Source: Processes, procedures, and methods to control
pollution from mining activities. Environmental
Protection Agency Document 430/9-73-011.
Washington, U.S. Government Printing Office, 1973,
32
-------
be returned to its natural contours as provided for by the
Surface Mining Control and Reclamation Act of 1977.
Contour stripping involves the removal of mineral outcrops
around hillsides. This is accomplished by removing the overburden
above the mineral, starting at the outcrop and following the
mineral around the hillside (Figure 8). Additional cuts are made
into the hillside until the ratio of overburden to mineral
becomes too great for the ore to be removed economically. At
this point auger mining may be used to recover additional
mineral. Augers up to 7 ft (2.1 m) in diameter are used to drill
holes in excess of 200 ft (61 m) into the hillside to obtain
additional quantities of mineral (usually coal). Contour mines
can be very long,"even though the life of this kind of mine is
usually short. Contour stripping temporarily disturbs the land
(until it is reclaimed) by producing a hillside shelf bordered by
a highwall on one side and a precipitous slope on the other.*
Open pit mining is a method used to recover ore deposits
that apex at or near the surface (Figure 9). It is commonly used
to recover metallic ores, notably copper, iron, beryllium,
mercury, and aluminum. Open pits range in size from small borrow
pits (to supply construction materials for a locality) to the
enormous copper mines of the West. Overburden is removed to
expose the ore for excavation. Removal usually involves blasting,
* This type of surface coal mining is specifically regulated
under the provisions of the Surface Mining and Reclamation Act of
1977.
33
-------
^x vi; UNDISTURBED AREA
'' ' *•""
BENCH
, ... BENCH
^v;^;i^;>;^^':'-^'v>'./' v
^^"^^^^-^•:••^
_
'^VV-'^:''"V"J^>V-'.^ 'X UNDISTURBED AREA - -': •'";'" :-.-""^
*•'.': '••**-. 'sx^ ••• 'p. '-.*.'•. -..•.•••.••.••••»...•.'•.•''»'•.•'•<
" . 'V-
Figure 8. Contour stripping is used to remove mineral
outcrops around hillsides.
Source: Office of Water and Hazardous Materials, Development
document for interim final effluent limitations
guidelines and New Source Performance Standards
for the coal mining point source category. U.S.
Environmental Protection Agency, Washington, D.C.,
1976.
34
-------
TOO DEEPLY BURIED UNDER
WASTE TO BE STRIPPED AND MINED
Figure 9. Open pit mining is a surface mining
technique used when ore deposits are near the surface.
Source: Colorado Mining Association. Anatomy of a mine,
35
-------
loading, and hauling from the pit. This mining method produces
an open pit ringed by a series of descending benches.
Quarry mining is normally used to recover nonmetallic
minerals, primarily construction materials. The method of
extraction is essentially the same in open pits and quarries.
Beneficiation. Beneficiation is the processing of an ore to
control product size, remove unwanted constituents, and improve
o
product quality, purity, or assay grade. The beneficiation of
most construction materials (e.g., sand and gravel, crushed
stone, and gypsum) results in a final product. Most other ores
(especially metals) require further processing after beneficiation,
These additional processing operations (e.g., smelting and
refining) are not covered in the scope of this report.
Some operations are integrated (particularly the mining and
processing of ferrous metals). Mining, beneficiation, and one or
more of these extra processing steps (smelting, refining,
fabricating, and marketing, in that order) take place on site.
Notable examples of integrated operations are the copper industry,
in which several of the leading producers are integrated, and the
coal industry, in which a coal-using utility may be situated at
the mine site. When operations are integrated, solid wastes from
mining and beneficiation could be combined with wastes from
smelting, refining, and fabricating; however, efforts are
usually made to segregate the wastes.
Factors such as environmental impact and transportation costs
influence the location of the beneficiation facilities. Although
36
-------
some beneficiation facilities are located a considerable distance
from a mine (either for environmental reasons or because outlying
mines feed to a common facility), most are located at or very
near the mine site to minimize transportation costs.
Some ores require extensive beneficiation (Figure 10),
whereas others do not. Most require some size reduction (or
comminution), either to separate desirable from undesirable
material (gangue) or to increase the surface area of the ore to
allow further processing. Initial size reduction of run-of-mine
ore takes place during primary crushing. This step reduces the
crude ore to a manageable size in preparation for additional
treatment. Sometimes all, sometimes only a portion, of the
crushed material goes to the secondary crushers for further
reduction, which may be the final comminution process or only an
intermediate step. A further step, either wet or dry grinding,
reduces the ore to the optimum size for further treatment.
Solids usually are separated according to size to obtain
maximum production from the crushing and grinding equipment.
Because commercial crushing and grinding produce a distribution
of sizes regardless of the characteristics of the feed, screening
and classification are also required in almost all beneficiation
processes.
Concentration is used primarily in the beneficiation of
metallic ores. These ores normally contain mixtures of various
minerals, which must be separated from unwanted gangue before they
can become useful. Flotation, gravity concentration, magnetic
37
-------
U)
00
FROTH FLOTATION
GRAVITY CONCENTRATION
MAGNETIC SEPARATION
ELECTROSTATIC SEPARATION
DRY SCREENING EXTRACTIVE METALLURGY
WET SCREENING AGGLOMERATION
MINED fc
ORE
SIZE in_ ^rorrNTwr.
REDUCTION SCREENING
PRIMARY CRUSHING
SECONDARY CRUSHING
DRY GRINDING
WET GRINDING
^ n flir*: TTirATinfj ^
MECHANICAL
HYDROCLONES
CONCENTRATION
SCREENS
CENTRIFUGES
CLASSIFIERS
SEDIMENTATION
FILTRATION
FLOCCULATION
ROTARY DRYING
FLASH DRYING
CONTINUOUS TRAY DRYING
FLUIDIZED BED DRYING
__ THERMAL
DRYING
ORE^
CONCENTRATE
Figure 10. This generalized flowsheet shows the processes
involved in extensive beneficiation.
Source: Given, I.A., ed. SME mining engineering handbook,
-------
separation, electrostatic separation, and leaching are used for
this purpose.
Froth flotation is the most widely used method of
beneficiating complex and low-grade ores. This complex
physicochemical process takes place in an ore pulped with water.
The surfaces of one or more minerals in the pulp are made
water-repellent, and these minerals attach themselves to air
bubbles. As the mineral-laden bubbles rise to the surface, they
are skimmed off and sent to further concentration steps. By
changing process conditions (such as pH), a sequential series of
flotations may be obtained from a given pulp. Frothers are also
used to keep the air bubbles intact so that the floated minerals
9
will remain on the surface for removal.
Gravity concentration separates solids of different specific
gravities in a fluid medium (usually water or air, but sometimes
a heavy medium such as suspensions of magnetite and ferrosilicon),
Mineral mixtures susceptible to separation by gravity methods are
those in which valuable minerals and gangue differ appreciably in
specific gravity. Methods include the simple sluice, the pinched
sluice, Humphrey's spiral, the sink-float mechanism, the jig, the
2
shaking table, and various dry methods.
Magnetic separation sorts one solid from another by means of
a magnetic field. The only important highly magnetic mineral is
magnetite. Many other minerals are measurably susceptible to
magnetic action, but fewer than 20 are amenable to magnetic
separation, and these are classed as weakly magnetic.
39
-------
Electrostatic separation is used to recover ilmenite,
rutile, and zircon from beach sands and to remove feldspar and
2
mica from quartz. This separation is based on the characteristic
behavior of particles subjected to a surface electrical charge
on or before entering an electrostatic field.
Leaching dissolves gangue or metal values in aqueous acids
9
or bases, liquid metals, or other special solutions. Leaching
solutions can either be strong general solvents (e.g., sulfuric
acid) or weaker specific solvents (e.g., calcium sulfate).
General solvents attack several ore constituents, whereas
specific solvents attack only one or, at most, a few. Solvent
action can be increased by heating, agitating, or applying
pressure.
There are a variety of leaching techniques. In-vat leaching
takes place in a container, which may or may not be equipped to
heat, agitate, or pressurize. In situ leaching takes place in
the ore body (the solvent is introduced into the ore body by
pumping or percolation through overburden). Heap or dump leaching
refers to the leaching of stored tailings or ore on a surface
that has been lined with an impervious material (clay or plastic
sheeting). In this technique the solvent is sprinkled over the
heap and the leached material is collected in furrows or troughs.
Metals covered in this report that require some recovery by
leaching are gold, copper, mercury, and silver.
If wet screening, classification, or concentration techniques
are used or if ore moisture content is initially high (as in
40
-------
dredged material), some form of dewatering must precede the
drying process. The dewatering process includes the use of
screens, centrifuges, classifiers, sedimentation, filtration, and
flocculation.
In commercial drying of concentrates, heat is transferred by
convection (direct contact between the wet solid and hot air).
Rotary, flash, continuous-tray and fluidized-bed dryers are some
of the variety of commercial thermal dryers available. After
2
drying, the mineral is generally stored for shipment.
All these beneficiation processes mentioned are not required
for every mineral ore. Many construction materials require only
size reduction, screening, and drying; whereas metals require
extensive concentration steps. To use the generalized flowsheet,
however, it is only necessary to delete those steps that are
unnecessary for a specific mineral.
Magnitude of the Mining Industry
A domestic demand for more than 4 billion tons (3.6 Pg) of
new mineral supplies each year results from an annual per capita
consumption of some 20 tons (18 Mg). The tremendous increase
in the size and value of this industry over the past century has
been critical to the growth of the Nation, and it is expected to
continue to play an essential role in the future.
Number of Mines. In 1975 there were 21,473 metal, nonmetal,
11 12
and solid mineral fuel mines in the United States. ' The
combined total of metal and nonmetal mines increased from 14,775
to 15,014 between 1965 and 1975. An increase in nonmetal mines
41
-------
for the recovery of, sand and gravel and stone was offset somewhat
by decreases in all metal mines (1,631 to 609) and other nonmetal
mines (1,914 to 1,814). The decreases in metal and nonmetal
mines represent the closing of many small mines; larger mines
[producing over 10 million tons (9.1 Tg) of crude ore per year]
actually increased in number (14 to 25) during this 10-year
period. Copper, iron ore, molybdenum, phosphate rock, sand and
gravel, and stone recovery accounted for the large mines in 1975.
Inactive and abandoned mines (as well as active) put a
significant stress on the environment, ranging from unfavorable
aesthetics to sediment transport and acid drainage that affect
miles of streams. Inactive and abandoned mines and their
associated waste disposal areas contribute a large portion of the
total pollution resulting from mining activities.
The terms "inactive" and "abandoned," often used
interchangeably, refer to nonoperating mines. Inactive implies
that the mine is not currently operating but could reopen,
depending on market conditions or changes in extraction and/or
processing technology that would make resumed mining economically
feasible. Abandoned implies that the legal right to resume
mining has been relinquished. Nonfuel mineral mines are rarely
abandoned.
Adequate data are not available to assess the impact of
inactive and abandoned mines. An unpublished report cited in a
recent publication indicates that the number of inactive and
abandoned underground mines was approximately 88,000 in 1966
42
-------
14
(Table 1). Recent estimates indicate more than 200,000
inactive and abandoned underground mines exist in the United
14
States. An accurate national assessment of inactive and
abandoned mine sites is needed.
The Federal Surface Mining Control and Reclamation Act of
1977 requires each state to survey inactive and abandoned surface
coal mines within its borders as a prerequisite to certification.
If and when noncoal mines are impacted by this regulation, they
too will be surveyed.
Mine Production. The most recent compilation of domestic
mine production statistics is found in the Bureau of Mines
Minerals Yearbook, 1975 edition. Statistics on ore, waste, and
marketable product by commodity presented in the chapter entitled
"Mining and Quarrying Trends in the Metal and Nonmetal Industries,"
were used to develop ratios of crude ore to marketable product
for each commodity. These ratios were then combined with
projected marketable product production for the years 1977, 1985,
and 2000 to estimate the quantity of crude ore that will be mined
for each commodity (Table 2). The estimated marketable product
figures used in making these estimates were obtained from the
Bureau of Mines Minerals Facts and Problems and the Bureau of Mines
Commodity Summaries 1978.
Crude ore production estimates are based on the assumption
that the ratio of crude ore to marketable product developed with
1975 data will remain constant through the year 2000. It is
probable that the ratio of crude ore to marketable product will
43
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TABLE 1
ABANDONED AND INACTIVE UNDERGROUND MINES IN
THE UNITED STATES AS OF 1966*
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Total
Coal
310
6
269
32
565
115
11
1,605
960
1,138
528
12,045
564
1
466
334
5
48
5
2,187
251
61
7,824
1
2,931
21
44
14,397
247
20,616
26
67,613
Metal
64
773
186
3,045
1,699
6
62
1,749
39
60
681
4
7
7
7
278
87
1,520
1,691
1,346
24
26
277
61
78
12
35
283
1,140
160
2
30
172
42
31
1,348
17
14
907
389
295
18,654
Nonmetal
27
6
82
7
3
28
208
124
2
13
120
1
1
6
1
36
146
10
3
23
17
1,129
53
3
55
4
17
11
8
3
6
52
9
1
2,215
* Office of Water and Hazardous Materials. Inactive and
abandoned underground mines, water pollution prevention and
control. U.S. Environmental Protection Publication 440/9-75-007.
Washington, 1975.
44
-------
TABLE 2
PRIMARY PRODUCTION STATISTICS FOR THE DOMESTIC MINERAL COMMODITIES
Ratio of crude ore Crude ore production Percent of crude ore
to marketable product (1.000 tons) handled by surface
Commodities 1,000 tons: 1,000 tons '975 1977(e) 1985(e) 2000(e) and underground mines*
Major
associate
mlneralst
Major Total
producing number
states! of mine**
METALS
Bauxite 1.7:1 3,290 4,000 4.050 2,700 100 surface
Copper 193.5:1 269.000 288,315 483.750 735,300 89.1 surface
10.9 underground
Gold 374,815:1 10.120 15,708 26,180 33.880 85.8 surface
14.2 underground
Iron Ore 2.8:1 239.000 162,857 259,200 320.000 96.2 surface
3.8 underground
Ui
lead 17.3:1 9.850 10.197 12.456 16,781 100 underground
Mercury 236.8:1 63 288 225 225 93.4 surface
6.6 underground
Silver 2,165:1 1.100 3.740 4.400 5.000 28.3 surface
71.7 underground
Uranium 630.9:1 6,940 9.464 22.712 37.854 60.6 surface
39.4 underground
Zinc ,c o.i 8.580 11.945 15,480 28.380 0.9 surface
"•° 99.1 underground
Other* 61.081 56,200 91,960 130,990
Total metals 609,024 562.673 920,413 1.311,110
gal Hun
gold
silver
lead
molybdenum
copper
lead
silver
platinum group
manganese
titanium
copper
zinc
copper
gold
silver
none
copper
lead
Zinc
antimony
vanadium
molybdenum
copper
lead
cadmium
silver
copper
Arkansas
Alabama
Georgia
Arizona
Michigan
Utah
New Mexico
South Dakota
Nevada
Arizona
Minnesota
Michigan
Missouri
Idaho
Colorado
Utah
Nevada
California
Alaska
Idaho
Ari zona
Colorado
Utah
New Mexico
Wyoming
Tennessee
Missouri
New York
Colorado
12
61
99
68
33
12
64
164
36
60
609
(continued)
-------
TABLE 2. (continued)
CoModities
Ratio of crude ore Crude ore production Percent of crude ore
to marketable product (1.000 tons) handled by surface
1,000 tons:l. 000 tons 1975 1977(e) 1985(e) 2000(e) and underground mines*
Major
associate
mineralst
Major Total
producing number
states! of mines*
NONHETALS
Asbestos
Clays
Diatonite
Feldspar
Gypsum
Mica (scrap)
Perlite
Phosphate rock
15.0:1 1,450 1.575 2.400 3.000 100 surface
1.0:1 43.400 56.251 100.000 190.000 100 surface
1.5:1 872 956 1.500 3,000 100 surface
1.9:1 1,310 1,454 2,185 3.800 100 surface
1.0:1 10.100 13,900 15.000 20.000 80.8 surface
19.2 underground
7.9:1 521 1,296 1.501 1,849 100 surface
1.4:1 706 1,085 1.260 2.240 100 surface
3.8:1 186,000 186.200 304.000 323,000 100 surface
none
silica.
sand and
gravel
none
lithium
mica
clays
limestone
clay
clay
feldspar
lithium
none
uranium
fluorine
California
Vermont
Arizona
North Carolina
Georgia
Texas
Ohio
North Carolina
California
Kansas
Nevada
Oregon
Washington
North Carolina
Connecticut
Georgia
California
Michigan
California
Texas -
Iowa
North Carolina
Alabama
Georgia
South Carolina
New Mexico
Arizona
California
Nevada
Florida
North Carolina
California
Idaho
3
1.249
IS
18
68
12
12
47
(continued)
-------
TABLE 2. (continued)
Ratio of crude ore
to marketable product
Commodities 1,000 tons:!. 000 tons 1975
NONMETALS (continued)
Potassium salts 8.6:1 17.800
Pumice 1.0:1 3.890
Salt 1.1:1 14.900
Sand and gravel 1.0:1 789,000
Sodium carbonate 2.0:1 8.010
(natural)
Stone: crushed 1.0:1 899.000
Stone: dimension 2.2:1 2.330
Talc 1.2:1 645
Other** 10,483
Total nonmetals 1,990.417
Crude ore production
(1,000 tons)
1977(e) 1985(e)
19.952 17,200
4,109 6.500
47,227 85.580
898.000 1.390,000 ?,
12,276 22,000
914,000 1.550,000 2,
3,080 3,300
1.265 2.040
10,800 16,200
2,173.426 3.247.066 5,
2000(e)
8,600
10,600
142,230
090.000
34,000
500.000
3,300
2.880
26.700
365.199
Percent of crude ore
handled by surface
and underground mines*
100 underground
100 surface
3.2 surface
96.8 underground
100 surface
100 underground
96.2 surface
3.8 underground
96.1 surface
3.9 underground
75 surface
25 underground
Major
associate
mineralst
none
none
magnesium
bromine
potassium salts
none
none
clay
lithium
gypsum
clay
lithium
gypsum
none
Major
producing
states!
New Mexico
Utah
California
Oregon
California
Arizona
Louisiana
Texas
New York
Michigan
California
Alaska
Texas
Michigan
Wyoming
California
Pennsylvania
Illinois
Texas
Missouri
Indiana
Georgia
Vermont
Ohio
Vermont
Montana
New York
Texas
Total
number
of mines*
8
224
19
7.007
3
5.203
381
40
96
14.405
(continued)
-------
TABLE 2. (continued)
oo
Camodittes
1975
Crude
1977(e)
ore production
(1.000 tons)
1985(e) 2000(e)
Percent of crude ore Major
handled by surface associate
and underground mines* minerals!
Major Total
producing number
states! of nines*
SOLID MINERAL FUELS
Co*1. anthracite
Coil, bituninous
and lignite
Total nineral fuels
Tota) all comnodities
6,203
646,000
654.203
3.253,400
6.200
685.000
691,200
3.427.300
6.000 6.000
993.000 1.655,000
999.000 1.661,000
5,166.500 8,337.300
94 surfacet none
6 underground
56 surfacett none
44 underground
Pennsylvania
Kentucky
West Virginia
Pennsylvania
Illinois
291 1
6.168tt
6.459
21.478
* U.S. Bureau of Mines. Minerals yearbook. 1975 ed. Washington, U.S. Government Printing Office, 1975.
t U.S. Bureau of Mines. Mineral facts and problems, bicentennial edition. Washington, U.S. Government Printing Office, 1976.
i U.S. Bureau of Mines. Mineral commodity summaries 1978. Washington, U.S. Department of the Interior, 1978.
1 Antimony, beryllium, manganiferous ore, molybdenum, monazHe, nickel, platinum group metals, rare earth metals, tin, titanium, ilmentte,
tungsten, vanadium.
** Abrasives, apllte, barite, boron minerals, fluorspar, graphite, greensand marl, iron oxide pigments (crude), kyantte, lithium minerals.
•agneslte. Millstones, olivine. vermicullte.
tt 1977 Keystone Coal Industry Manual. New York, McGraw-Hill Mining Publications, 1977.
(e) Estimate.
Note: Crude ore estimates for the other categories were calculated as a percent of the total crude ore production for each year. The percentage
used was derived from the 1975 data and assumed to be the same for the other years.
Note: Metric conversion table In front matter.
-------
actually increase somewhat from 1975 to 2000 as increased
reliance on lower grade resources necessitates removal of more
ore per unit of marketable product. The crude ore estimates will
then be somewhat low.
In 1975 the U.S. mining industry produced 2.6 billion tons
(2.4 Pg) of crude ore, excluding coal. A total of 4.2 billion
tons (3.8 Pg) of material (crude ore and waste) was handled.
Eleven states reported handling more than 100 million tons (91
Tg) of material each, and three states (Arizona, Florida, and
Minnesota) accounted for 33 percent of the total material
handled. The 1975 production of bituminous and lignite coal by
12
domestic mines was over 648 million tons (588 Tg).
Land Utilization. All mining operations disturb the land
surface to some extent. Increased demand for minerals has
resulted in technological advances in both equipment design and
mining engineering practices and increased land use (because of
the need to extract greater quantities of materials to meet the
increasing demand for minerals in lower grade ore deposits).
Exploitation of more low-grade and submarginal deposits also
requires more land usage for disposal of the greater quantities
of solid wastes associated with low-grade ores.
A U.S. Bureau of Mines report detailing the land utilization
(exclusive of secondary transport of wastes) by the mining
industry during the period from 1930 to 1971 estimated some 3.65
2
million acres (14.8 Gm ), approximately 0.16 percent of the
Nation's land area, had been affected. These data are broken
49
-------
down geographically by state and type of mining activity (Table 3
and Figure 11). Although underground mines undercut extensive
areas, the total area they affected was greatly overshadowed by
that affected by surface mines. In 1971 alone, some 206,000
2
acres (834 Mm ) of land were affected by mining operations.
Exclusive of land affected by wastes transported from
mining areas by wind and water, a comparison of mining land usage
with other land usage during the 1930 to 1971 period shows that
the land area used by mining was similar to that used by
railroads or airports in operation at the end of 1971 (Table 4).
It is estimated that highways utilized six times more land than
mining during this period. Approximately 72 percent of the
mining land usage was accounted for by three commodities:
bituminous coal, sand and gravel, and stone (Figure 12).
Mining industry land usage encompasses the mined area,
mining waste disposal areas, areas affected by subsidence, and
processing waste disposal areas. The excavated area accounts for
more than half of the total land required for mining operations,
and waste disposal areas account for about a third (Figure 13).
A survey conducted by the Soil Conservation Service estimates
2
a total of 5.7 million acres (23 Gm ) or 0.25 percent of the
Nation's land area had been affected by surface mining as of July
1, 1977 (Tables 5 and 6). Of this total, approximately 1.9
2
million acres (7.7 Gm ) has been reclaimed to some extent, either
naturally or by the landowners. The remaining 3.8 million acres
50
-------
TABLE 3
LAND UTILIZED BY THE MINING INDUSTRY* IN THE UNITED STATES
IN 1930-71, BY STATE AND FUNCTIONt
(acres)
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Surface
Mined
area
39,700
22,300
26,600
18,700
105,000
30,200
8,730
960
71,500
23,600
3,460
16,700
201,000
125,000
38,300
27,500
146,000
12,900
7,620
17,800
14,600
64,600
72,300
7,680
55,300
22,200
9,170
12,000
3,750
18,500
19,600
55,800
24,100
25,700
206,000
24,800
22,100
221,000
1,730
9,840
10,900
40,500
54,000
18/900
2,870
42,600
24,500
96,500
32,300
14,800
mining
Waste
area
12,900
3,550
34,900
6,180
57,100
5,750
2,180
230
10,300
5,420
810
3,980
63,800
39,300
10,100
7,970
49,000
3,260
1,900
4,760
3,650
17,100
37,900
1,890
15,500
14,100
2,310
11,100
1,020
4,590
13,900
12,600
6,550
8,350
63,400
6,900
5,290
64,500
370
2,300
2,980
12,300
13,300
19,200
860
13,100
6,470
30,600
8,730
9,040
Underqround
Subsided or
disturbed area
2,080
100
2,910
260
2,230
1,320
10
520
6,320
1,270
260
70
9,470
180
1,690
180
350
2,160
210
4,310
190
70
2,980
130
35,600
100
1,430
520
920
3,620
260
22,200
60
620
mininq
Surface
waste area
4,830
60
360
290
12,200
3,310
30
3,010
14,600
2,930
570
150
22,100
10
400
840
610
600
10
2,170
100
2,140
190
150
6,860
300
43,600
120
2,200
570
2,200
30
8,410
400
51,800
30
1,450
3enef iciation
Surface
waste area
5,510
3,610
37,600
4,130
50,400
8,200
1,390
130
7,040
5,240
540
17,100
10, 500
6,060
6,030
8,290
7,030
2,070
1,020
2,540
2,100
15,300
26,100
1,140
30,700
5,450
1, 360
13,700
530
5,000
7,840
27,400
6,020
770
12,600
3,410
6,600
16,500
220
2,390
2,420
11,300
9,650
25,500
3,630
11,100
4,350
8,770
5,780
2,410
Total
land
utilized f-
65,100
29,600
102,000
29,500
227,000
48,800
12,300
1,330
88,800
34,300
4,810
41,300
297,000
175,000
55,300
44 , 000
234,000
18,200
10,500
25,600
20,300
99,500
136,000
10,700
102,000
42,800
12,800
41,100
5,300
28,400
47,800
96,300
36,600
35,100
292,000
35,500
34,000
381,000
2,330
14,500
16,500
67,800
78,000 •
66,700
7,380
78,800
35,900
210,000
46,900
28,300
Totals
2,170,000
733,000
105,000
190,000
454,000
3,650,000
* Excludes oil and gas; also does not include land disturbed by waste that has been eroded,
transported, and deposited in some other area by wind and running water. Figures also omit areas
damaged by acid mine drainage and SO- fumes.
t Prtone, j., J.L. Morning, and L. Giorgetti. Land utilization and reclamation in the mining
industry, 1930-71. Bureau of Mines Information Circular ICB642. Washington, U.S. Government Printing
Office, 1974.
§ Data may not add to totals shown because of independent rounding.
Note: Metric conversion table in front matter.
51
-------
(Jl
ACRES UTILIZED
C=D Under 20.000
I—1 20,000-50.000
ES3 50.000-150,000
• Over 150,000
Figure 11. Geographic distribution of land utilized by mining
activities 1930-1971 is depicted graphically.
Source: Paone, J. Land utilization and reclamation 1930-71.
-------
TABLE 4
COMPARISON OF LAND USES IN THE UNITED STATES
IN 1971*t
Activity Million acres
Total United States 2,271.3
Agriculture§ 1,283.0
Cropland 472.1
Grassland pasture and range 603.6
Forest land grazed 198.0
Farmsteads, farm roads 8.4
Forest land not grazed 525.6
Urban areas 34.6
National Park system 29.6
Highways 22.7
State Park system 8.6
Miningll 3.7
Airports 3.3
Railroads 3.2
Municipal and county park and recreational areas 1.0
* Estimates based primarily on reports and records of the
Bureau of Census and Federal and state agencies.
t Paone, J. Land utilization and reclamation 1930-71.
§ 1969 data.
11 Land utilized 1930-71, exclusive of land affected by
transport of wastes by natural processes.
Note: Metric conversion table in front matter.
53
-------
PHOSPHATE
ROCK
2%
IRON ORE
3%
COPPER
5%
Figure 12. Land utilized by mining is shown by
selected commodity, 1930-71.
Source: Paone, J.
Land utilization and reclamation 1930-71
54
-------
SUBSIDED
AREA
3%
WASTE AREA
FROM UNDERGROUND
5%
PROCESSING
WASTE AREA
13%
WASTE AREA
FROM SURFACE
MINING
20%
MINED AREA
(EXCAVATED)
:'-- 59%
. n,ft Figure 13. Land usage by mining in the United States,
J.930-71, is shown according to function.
Source: Paone, J. Land utilization and reclamation 1930-71
55
-------
TABLE 5
STATUS OF LAND DISTURBED BY SURFACE MINING IN THE U.S.
AS OF JULY 1, 1977, BY STATES*
(acres)
Land needing
Reclamation not required
b/ my U.
State
Alabama
Alaska*
Arizona*
Arkansas
California
Caribbean Area*
Colorado
Connecticut*
Delaware
Florida
Georgia
Ha«an
Idaho
1 1 1 inoi s
Indiana
loxa
Kansas
Kentucky
Louisiana*
Maine
Maryland
Massachusetts*
Michigan
Minnesota
Mississippi*
Missouri
Montana
Nebraska*
Nevada
lie* Hampshire
Ne« Jersey*
Ne« He, ico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
IhTde IsUnd*
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
TOTAL
Coal
nines
72.29?
2,700
400
5,623
10
7.069
1.680
116,711
25,88?
13,997
41.256
101,637
2.804
142
70,688
1.995
22
1.050
196.709
36,118 •
240.000
890
29,583
3,310
635
23,724
48
84.868
9,657
1,093,520
Sand ind
gravel
16,611
4.300
6.400
21.483
7,970
2.550
8,334
16.740
2,912
11.162
3,353
15
5.100
20,330
11,875
10,147
11,150
980
37,324
28,833
7,430
32.041
39,424
30,047
45,966
4,473
4.655
17.969
1,221
12,725
24,610
11,860
30,917
11,908
2.010
22,621
6,659
3.521
11,000
2.592
9,065
10.153
4,950
152,457
3,999
3,877
3,788
9,701
4.554
41,607
3.673
799,042
Other
mined
areas
19,929
4,000
60.900
11,479
80,998
1.000
15,861
787
63
235,700
24,008
115
1,500
14,192
6,522
6.421
10,159
4.712
2,549
2,075
1,181
10,330
23,422
44.801
7.821
28.187
18.340
4,029
2.555
417
5,570
1,806
19,251
4.792
200
18.923
14,105
17.568
20.500
2.128
5,259
2.305
37,104
4,414
2.078
1,251
8.174
995
7.555
12.376
830,407
reclamation
Reclamation required
by la-
Coal
mines
34,807
2,859
500
1.195
764
40.899
74.581
341
815
154.218
5.703
8,772
4,766
3.709
6.725
77.050
6.298
3
60,000
3.127
3,725
133
8,222
1,190
7,658
62,028
570,088
Sand and
gravel
5,498
20
17,642
11,672
3,365
4,623
18.200
8,582
4,176
8.457
3,634
2.299
2,293
9.741
15.662
12.444
1.046
4,492
1.057
15,979
7,096
16.659
2,766
6.814
15.000
4,395
6.826
810
6.289
4,637
377
3.929
11,822
11.884
7,665
257.051
Other
mined
areas
6.252
1.592
51,316
6.513
20,922
13.772
3.500
4,557
1.894
9.638
3.978
2.780
923
1.734
4.072
7.891
6,055
6.598
26,072
5,037
3,909
8.427
4,110
1.538
25,000
3,194
695
1.135
4.989
10.216
60
2,003
1.073
2.865
12,787
267,097
Land not
requiring
ret 1 ana t ion
85,673
4,000
121.800
9,449
59,061
710
14.023
4,590
1.498
61,266
23.247
2.500
88,860
64.711
10,519
20,117
154.495
10,457
6,794
19,824
11,750
27,600
66.919
14,415
22.051
12,528
11,005
1.953
547
8,263
2,207
18.477
7,000
38.595
190.578
16.255
7,387
250,000
.1,47'J
9.815
7.149
101.596
48.456
7.521
1.536
'0,060
10,245
137.105
11,605
5.511
1.898.203
Total
land
disturbed
241,062
15.000
189.500
52,505
216,777
4,260
64.687
22,117
4,473
332.415
71,447
130
30.800
296.131
139,641
59.520
91,109
421,121
50.340
40,918
48.417
54,121
110.322
162.102
66,202
141,272
53.334
33.003
5,729
13.669
38,443
46,733
89.662
34.705
48.580
530,967
65.311
26,831
621.500
6,06?
28,597
30.972
146.506
256,330
31,555
7,928
112.977
42,253
235,180
85.516
113,697
5.715.408
• Basic Statistics - Status of land disturbed by surface mining In the U.S. as of July 1, 1977, by states, (draft)
U.S. Soil Conservation Service. U.S. Department of Agriculture, Washington, 1977. (Values do not include land disturbed by waste
that has been eroded, transported, and deposited in some other area by wind and running water. Figures also omit ireas damaged by
acid mine drainage and S0? fumes.)
Note: Metric conversion table in front matter.
56
-------
TABLE 6
STATUS OF LAND DISTURBED BY SURFACE MINING IN THE U.S
FROM JANUARY 1, 1965 TO JULY 1, 1977*
(thousand acres)
1965
Land
Land
Total
requiring reclamation
not requiring reclamation
land disturbed
2040.
1147.
3187.
6
2
8
1972
2181
1823
4004
.2
.7
.9
1974
2542.
1876.
4418.
7
0
7
1977
3817.
1898.
5715.
2
2
4
* Basic Statistics - Status of land disturbed by surface
mining in the U.S.
Note: Metric conversion table in front matter.
2
(15 Gm ) has not been reclaimed at all. Reclamation of 2.7
2
million acres (11 Gm ) of this land is not required by law. This
study presents information on both reclaimed and unreclaimed
surface-mined land in each state (by county).
57
-------
REFERENCES FOR SECTION 2
1. Peisse, F.H., D.W. Lockard, and A.E. Lindquist. Coal
surface mining reclamation cost in the western United
States. Bureau of Mines Information Circular IC8737.
Washington, U.S. Government Printing Office, 1977.
2. Given, I.A., ed. SME mining engineering handbook, v. 1.
New York, Society of Mining Engineers of the American
Institute of Mining, Metallurgical, and Petroleum Engineers,
Inc., 1973.
3. Update: Underground mining in the U.S. Mining Engineering,
July 1975.
4. Colorado Mining Association. Anatomy of a mine--from
prospect to production. Denver, 1975.
5. Williams, R.E. Waste production and disposal in mining,
milling and metallurgical industries. Miller Freeman
Publishing Company, San Francisco, 1975.
6. Coal Age. Coal age operating handbook of underground mining.
v. 1. Coal Age Library of Operating Handbooks. New York,
McGraw Hill, Inc., 1977.
7. U.S. Department of the Interior. Surface mining and our
environment. A Special Report to the Nation. Washington,
U.S. Government Printing Office, 1967.
8. Thrush, P.W., ed. A dictionary of mining, mineral, and
related terms. Washington, U.S. Government Printing
Office, 1968.
9. U.S. Environmental Protection Agency. Development document
for interim final and proposed effluent limitations
guidelines and New Source Performance Standards for the
ore mining and dressing industry, point source category.
2 v. U.S. EPA Document 440/1-75-061. Washington,
U.S. Government Printing Office, 1975.
10. U.S. Bureau of Mines. Mineral facts and problems,
bicentennial edition. Washington, U.S. Government
Printing Office, 1975.
11. U.S. Bureau of Mines. Minerals yearbook, 1975 ed. (Preprint)
Washington, U.S. Government Printing Office, 1975.
12. Bel, L.C. 1977 Keystone coal industry manual. New York,
McGraw Hill Mining Publications, 1977.
58
-------
13. Office of Research and Development. Water pollution caused
by inactive ore and mineral mines, a national assessment.
U.S. EPA Publication 600/2-76-298. Washington, U.S.
Government Printing Office, 1976.
14. Office of Water and Hazardous Materials. Inactive and
abandoned underground mines, water pollution prevention
and control. U.S. EPA Publication 440/9-75-007.
Washington, 1975.
15. Personal Communication. E. Johnson, U.S. Department of
Agriculture, to J. Greber, PEDCo. March 23, 1978.
16. Paone, J., J.L. Morning, and L. Giorgetti. Land utilization
and reclamation in the mining industry, 1930-71. U.S.
Bureau of Mines Information Circular IC8642. Washington,
U.S. Government Printing Office, 1974.
17. Basic Statistics - Status of land disturbed by surface
mining in the U.S. as of July 1, 1977, by states. (Draft)
U.S. Soil Conservation Service, U.S. Department of
Agriculture, Washington, 1977.
59
-------
SECTION 3
SOURCES, QUANTITIES, AND CHARACTERISTICS OF
MINERAL RESOURCE SOLID WASTES
Mineral resource wastes are estimated to comprise 40 percent
of the solid wastes produced annually in the United States; they
are second only to agricultural wastes in volume. In 1975 these
wastes amounted to about 2.3 billion tons (2.1 Pg), and by the
years 1985 and 2000, annual generation could reach as high as
4 and 6 billion tons (3.6 and 5.4 Pg). It should be pointed out
that all of the waste generated does not necessarily end up in
waste heaps and impoundments. Some is returned directly to the
mine, some is used in onsite construction projects (roads, dams,
base fill, etc.), some is sold as byproducts, and at some
underground operations a portion is backfilled into mined-out
areas and therefore remains underground. It should be noted also
that most mining companies that now dispose of solid wastes on
the land eventually reclaim or rehabilitate these disposal areas
to some degree. The above comments would seem to lessen the
magnitude of the problem; however, large volumes of solid wastes
continue to be deposited on the land each year, and volumes of
solid wastes generated during past operations still remain at
numerous inactive mine sites throughout the country. Dean and
Havens estimated that by 1972 total mineral resource solid wastes
60
-------
at active and inactive mining sites would total 25 billion tons
2 2
(22.7 Pg) and cover 2 million acres (8.1 Gm ) of land. Unless
properly handled and stabilized, solid wastes of this magnitude
will pose a serious threat to the environment.
This section presents an analysis of the nature and extent
of solid wastes associated with surface and underground mining
and processing of metallic ores, nonmetallic ores, and solid
mineral fuels (bituminous, lignite, and anthracite coals). For
purposes o'f this document, processing wastes are considered to be
those generated by ore beneficiation (including leaching).
Mineral resource wastes generated by roasting, smelting, refining,
and other chemical processing following beneficiation are not
included.
Sources and Classification of Mineral Resource Solid Wastes
In the mining industry both the extraction of ore from the
earth (mining) and the processing of the ore to recover a
marketable product (beneficiation) generate solid wastes. The
number and kinds of steps involved in mining and processing vary
throughout the industry; therefore the quantities and
characteristics of the solid wastes generated also vary.
The beneficiation steps are determined by the nature of the
ore deposit, its associated geologic materials, and the desired
end product. For example, at some sites beneficiation of many
nonmetal minerals (e.g., sand and gravel, feldspar, stone) may
consist only of crushing and classifying or simply classifying to
produce a marketable product, whereas crushing, classifying,
61
-------
concentrating, and drying may be required at others. On the other
hand, ferrous and nonferrous metal ores must be further treated
after mining and beneficiation to obtain a marketable product.
Copper, for example, must be smelted, refined, and fabricated
before it is marketable. Conversely, in the solid mineral fuel
industry, numerous small coal mine operations now extract the
coal from the mine and transport it directly to the consumer, and
little or no processing is involved. At most large operations,
however, the coal is crushed, screened, and washed before it is
marketed. In the future, other beneficiation steps, including
flotation to remove pyrite, may become commonplace in the coal
industry.
Although there is a wide variation in the required
processing steps, typical mining operations require ore
extraction and some form of beneficiation to produce either a
marketable product or a concentrate suitable for further
processing. Most beneficiation operations are at or near the
mine site to minimize costs of transporting unwanted material.
Occasionally, however, ore must be transported to a site some 25
to 75 miles (40 to 121 km) away because (1) land is not available,
either for the beneficiation facility or to dispose of the waste
it generates; (2) proper utilities are not available; (3)
environmental considerations prohibit a mine and a processing
facility at the same site; (4) a single common beneficiation
facility is used to process ore from several mines in a region.
62
-------
Normally processing steps beyond beneficiation (e.g.,
smelting, refining, fabricating, and exfoliation) are located
away from the mine site. Occasionally, however, these operations
are located on site. For example, some large copper operations
and lead-zinc operations are completely integrated. Mining,
beneficiating, smelting, refining, fabricating, and marketing
operations are all located in the same general area. The solid
waste problems at such operations are considerably more complex
than those involving only mining and beneficiating. When
combinations of wastes other than mine and beneficiation wastes
are discarded along with mine and beneficiation wastes, the
probability of the development of hazardous conditions increases
significantly.
Because the most common arrangement is one in which the
beneficiation facility is on or near the extraction site, this
document considers only those mineral resource solid wastes
generated by ore extraction and beneficiation.
The sources of solid waste evaluated in this study are
divided into three general categories: (1) mine wastes, (2)
beneficiation wastes, (3) miscellaneous wastes.
Mine Wastes. These wastes are generally referred to as
overburden at surface mining operations and waste rock or
development waste rock at underground operations (although they
are also called gob, spoil, and refuse). Thickness and
characteristics of overburden vary according to the kind of
deposit and the mining method. Although almost all overburden is
cverlaid by some topsoil, its thickness and quality vary.
63
-------
Overburden associated with the mining of most nonmetallic
ores generally consists of topsoil and other unconsolidated
materials (e.g., sand, gravel, silt) and occasionally a little
bedrock. Overburden associated with the mining of most metallic
ores contains varying amounts of bedrock in addition to topsoil
and other unconsolidated materials. The waste rock associated
with underground mines consists of both the consolidated and
unconsolidated materials generated during various stages of mine
development (e.g., shaft, tunnel, adit, and drift development)
and that produced in association with ore extraction. The pyrite
content of mine waste is a critical factor in regard to whether
or not it constitutes a hazard to the environment, particularly
in humid climates.
Overburden disposal methods are a function of the kind of
deposit being mined, the mining method, and the waste-to-ore
ratio (see Section 5 for additional details). The most common
methods are (1) casting the overburden into mined-out areas;
(2) piling the waste on the land along the edges of the mine cut;
(3) hauling the waste by truck, rail, scrapper, or conveyor to a
mine waste dump on or near the mine site.
Regardless of the disposal method, it is common practice to
segregate topsoil from the rest of the overburden and stockpile
it for later use in reclamation projects. At some ferrous and
nonferrous metal mining operations the bedrock portion of the
overburden is segregated into two categories—barren rock and
submarginal or low-grade ore. The barren rock, which has no
64
-------
potential ore value, is usually combined with other useless
components of the overburden. The submarginal or low-grade ore,
which contains low concentrations of the material that is being
mined, is stockpiled (sometimes in several different piles
according to mineral identification, grade, or concentration) for
possible recovery processing at some future time when market
conditions and technology advancements make such processing
economically feasible.
Waste rock generated during the early development of
underground mines is hauled to the surface and disposed of in
mine waste dumps similar to those at many surface mining
operations. After the initial developmental stages, much of the
waste rock is disposed of in underground mined-out areas.
A small portion of the mine waste at some surface and
underground mining operations is used in onsite road and dam
construction or sold as a byproduct.
Beneficiation Wastes. Beneficiation, which separates the
valuable mineral or minerals from the undesirable components of
an ore, creates large volumes of solid wastes. Wastes can be wet
or dry, depending on the beneficiation method, but most are in a
wet or slurry state. Beneficiation wastes are normally referred
to as "tailings"; however, other terms are also used, depending
on the type of mineral being processed, the geographic location
of the operation, and the physical and chemical characteristics
of the waste. In the kaolinitic clay industry, the waste created
when crude clay ore is passed through a degritting operation to
65
-------
remove coarse sand and mica by gravity settling boxes and/or wet
cyclones is referred to as "grit." In the phosphate industry,
the ore beneficiation process produces two separate solid waste
streams, one composed of coarser sandy materials (referred to as
"waste sands" or "sand tailings") and the other composed of very
fine phosphatic clays (called "slimes," "clay slimes," or "waste
slimes"). The solid wastes produced during coal beneficiation
(cleaning) are typically referred to as "gob," "slurry," "culm,"
or "black water." Other terms include "washery rejects,"
"fines," and "refuse." Although each of these terms is used to
describe solid wastes generated during the beneficiation of ore,
"tailings," the most widely accepted term, is the one used
throughout this document.
Most tailings are disposed of by pumping them to impoundments
referred to as settling ponds, slurry ponds, tailings ponds,
storage ponds, or impoundments. These ponds are contained by
embankments. (See Section 5 for additional information.) They
range from small pits, natural depressions, and swamp areas to
engineered 1000-acre structures with massive retaining dams and
regulated construction design. They generally are located
adjacent to or near mine waste disposal areas, and mine wastes
are often used in the construction of tailings ponds.
Although beneficiation wastes usually represent 95 to 100
percent of the total material discharged to tailings ponds, such
materials as mine drainage, noncontact cooling waters, some
surface runoff, residuals from pollution control equipment,
66
-------
treated domestic wastewaters/ and leaching precipitates are
sometimes discharged into these ponds. At some of the large
integrated operations, smelter slag and refinery sludges are
sometimes combined with beneficiation waste. At still other
facilities, the tailings pond is used to dispose of construction
wastes (e.g., scrap iron and wood), organic wastes from
cafeterias (e.g., food scraps and paper), and damaged or used
product and reagent containers. Most mining and beneficiation
facilities segregate the wastes as much as possible for
environmental reasons and to avoid contamination of recirculating
process waters. The practice of combining other mineral resource
wastes with tailings during disposal influences whether or not
beneficiation wastes constitute an environmental hazard.
Small quantities of tailings are disposed of by using them
for onsite construction (e.g., roads, base fill), selling them as
byproducts, and occasionally, reprocessing them to recover
mineral values. At some underground mining operations as much as
50 percent of the tailings may be backfilled into the mine to
fill in mined-out areas.
Miscellaneous Wastes. The solid wastes that make up this
third category are generated from various sources at a mining
operation. They include residuals from pollution control
equipment (dry and wet), treated domestic wastewaters,
construction wastes, used or damaged product or reagent
containers, and general office and cafeteria wastes. These
wastes are usually disposed of in the tailings ponds or landfilled
67
-------
on site. Prospecting, exploration, and mine site development
also create minor amounts of solid wastes such as drilling
muds; soils and bedrock from exploration pits, trenches, and
shafts; removed vegetation; soils and bedrock resulting from road
and building construction; and construction wastes (scrap wood
and iron).
Quantities of Mineral Resource Solid Wastes
The large quantities of solid wastes generated by the mineral
mining industry include overburden from surface mining operations
(e.g., soils, sand and gravel, barren rock, submarginal or
low-grade ore), waste rock from underground mines (e.g., some
unconsolidated materials, mine development wastes, submarginal
ores), beneficiation wastes (tailings), and a variety of
miscellaneous wastes (e.g., drilling muds, residuals from
pollution control equipment, and damaged construction materials).
Most of these wastes are generated by mining and beneficiation;
therefore the remainder of this section deals with these sources.
Researchers' estimates of the quantity of solid waste
produced annually by the U.S. mining industry vary according to
the number of mineral mining industries covered, the extent of
the processing operations included (e.g., mining and beneficiation
only or mining, beneficiation, smelting, and refining), and the
calculation method. Most estimates range between 1.6 and 2.0
billion tons (1.4 and 1.8 Pg)/yr. ' ' Annual solid waste
production statistics in this study are calculated from U.S.
68
-------
Bureau of Mines data, data appearing in various published and
unpublished documents, and information provided by the mining
industry.
Benefication waste quantities are calculated on a dry
weight basis; the quantities of water used to slurry these
wastes to impoundments are not included. Estimates of
beneficiation wastes do not include wastes associated with
leaching operations because they are almost impossible to
calculate. In most cases, both mine and beneficiation waste
quantities have been calculated for each commodity (Table 7).
When insufficient data made it impossible to calculate
beneficiation wastes for some mineral commodities (e.g., zinc
from surface mines), only mine waste statistics are presented.
It is also important to note that annual production of mine solid
waste (overburden and development waste rock) has not been
estimated for the coal industry because data were insufficient.
Although actual quantitative data are not available, it is
believed that the amount of mine waste (particularly overburden)
produced annually by the coal industry is larger than the total
amount of mine waste generated by all other mineral industries
combined.*
* It should be noted that many individuals consider
overburden produced by the coal industry to be a resource rather
than a waste because of its use in reclamation projects. This
philosophy is based on the fact that in recent years most
overburden has been reclaimed to some extent. The Surface Mining
Control and Reclamation Act of 1977, which requires the reclamation
of all overburden, has contributed to further support of this
philosophy.
69
-------
TABLE 7
1975 SOLID WASTE PRODUCTION STATISTICS AT SURFACE AND UNDERGROUND MINES AND ESTIMATED
TOTAL SOLID WASTES FOR 1977, 1985, AND 2000
(1,000 tons)
Commodity
METALS
Bauiite
Copper
Gold
Iron Ore
lead
Mercury
Sil.er
uranium
Zinc
Omer"
Total metals
NONMETALS
Asbestos
Clays
Oiatonite
Feldspar
G/psum
Mica (scrap)
Perl it*
Phosphate rock
Potassium salts
Pumice
Salt
Sand and gravel
Sodium carbonate (natural)
Stone:
Crushed and broken
Oinension
Talc, soapstone. pyrophyllite
OtherU
Total nonmetals
MINERAL FUELS
Coal, anthracite
Coal, bituminous and lignite
lotal mineral fuels
Tola) all commodities
Surface
Mine
•aste
13.100
689.000
9.030
256,000
1
509
21
154.000
42
44.210
1.166. 112
250
37.100
649
1.980
13.400
254
20
216.000
NA
118
87
NA
NA
71.200
1.210
1.760
27.726
371.954
I.', 18.U66
mining operations
Tailings'
1.407
237,850
8,560
150.816
1
59
315
4.994
,1
I'
404.001 1
1.353
^
298
627
500
456
195
137.300
NA
2
2B3
39. 4501 1
NA
0
93
*
180.557
',84 . 550
Total
14.707
926.850
17.590
406.816
1
568
336
158.994
44.2100
.570.113
1.603
37.100H
1.147
2.607
13.900
710
215
353.300
NA
120
370
39.450
NA
71.200-
1.210*
1,853
27.726*
552.511
2.l22.tc'4
Solid oaste statistics for 1975*
Underground mining operations Totals, all mining operations
Mine
waste
M
1.360
212
1.890
2.450
1
348
2.420
2.740
1.173
12.593
U
10
NA
NA
206
NA
NA
U
460
NA
617
NA
4.050
300
NA
9
109
5.761
l«. 154
Tailings'
U
29.003
1.569
3.779
9.282
1
791
2,735
8.127
f
55.286
U
0
NA
NA
8
IIA
NA
W
15.760
NA
683
NA
4.010
3
NA
ii
20.461
75.747
Total
U
30.363
1,781
5.669
11.732
t
1.139
5.155
10,867
1 . 1 7 3tf
67.879
U
10*
NA
NA
214
NA
NA
W
16.220
NA
1.300
NA
8.060
300*
NA
9t»
109*
26.222
94.101
Mine
waste
13.300
690.360
9.242
257.890
2.450
509
369
156.420
2.782
45.383
1.178.705
250
37.110
849
I.9HO
13.606
254
20
216,000
460
118
704
NA
4,050
71 .500
1.210
1.769
27.835
377.715
l.^b.4.0
Grand 1975 Uaste-lo-ore Estimated solid «aste>'
Tai 1 ingst
1.407
266.853
10.129
154.595
9.282
59
1.106
7.729
8.127
*
459,287
1.353
I
298
627
5118
456
195
137,300
15.760
2
966
39.450-
4.010
*
0
93
0
201.018
107.101"
107. IOI««
'f.7.406
total
14.707
957.213
19.371
412.485
11.73?
56H
1.475
164.149
10.909
45, 38 1s
1.637.992
1.603
37.110*
1.147
2.607
14,114
710
215
353.300
16.220
120
1.670
39.450"
8.060
71.500*
1.210*
1.662
25.176*
578,733
107.1011'
107.101"
2.32J.J26
ratios
4.47
3.56
1.91
1.73
1.19
9.02
1.34
23.65
1.27
0.74
1.11
0.85
1.31
1.99
1.40
1.36
0.30
1.90
0.91
0.03
0.11
0.05
1.01
0.08
0.52
2.89
2.40
0.17
1977
17.880
1.026.401
30.002
281.741
12.134
2.598
5.012
223.824
13.854
41.588)1
1.655.036
1.748
48.376*
1.252
2.893
19.460
1.763
326
353.780
18.156
124
5,194
44.900
12.199
71.120*
1 .602*
3.653
25.920*
614.666
116.450
116.450
2.269.702
1985
16.104
1.772.150
95.507
448.915
14.823
2.010
5.896
517.119
19.660
68.05V
2.982.294
2.664
86,00*
1.965
4.348
21.000
2.041
378
577.600
15.652
195
9.414
69,500
22.220
124.000*
1.716,.
5.896
38.880k-
981.469
163.810
168.810
4.114.573
2000
12.069
2.617.6*8
64.710
553.400
19.969
2.030
6.700
895.247
36.043
96.93*
4.304.969
3.330
163. 40C*
3.930
7.562
28.000
2.415
672
613.700
7.626
318
15.645
104.500
34.340
200.000*
1.716«
8.123
64.080*
1.259.8S7
281.350
281.350
S.8t4.l76
(continued)
-------
TABLE 7. (continued)
• (icept where Indicated otherwise, all 1975 solid waste statistics were adapted from Tables ? and II of the Preprint from the
197S Bureau of Mines minerals yearbook; Mining and Quarrying Trends in the Metal and Nnnmptal Industries; United States Department
of the Interior, Bureau of Mines.
t Estimated solid waste statistics include hnth mine w.i-.lr*. an«l tailint|S unless Mtherwi-.r imli( 4l<"l.
i Tailings are reported on a dry weight basis
i Value less than SOO tons.
f Estimates for tailings not available on these commodities; therefore the solid waste statistics include mine waste only
•• Antimony, beryllium, manganlferous ore, molybdenum, monaHte. nickel, platInum-qroup metals, rare-earth metals, titanium, ilmenite.
tungsten, vanadium, and quantity of metal items Indicated by symbol W.
M Abrasives, apllte, barlle. boron minerals, fluorospar, graphite, qri-pnsand marl, iron onlde pigments (crude), kyanlte. 1 it Mum minerals,
magneslte, millstone, ollvlne, vermlcullte.
Si Sand and gravel tailings estimated as 5 percent of total material handled.
11 Value obtained from the minerals yearbook, 1975, Volume I; Metals, Minerals and Fuels; United States Department of Interior; Bureau of
Mines; U.S. Government Printing Office, Washington, D.C., 19". This value Includes tailings waste (coal preparation plant waste) only. Mine
solid waste data (overburden and development waste rock) are not available for the coal Industry. Although actual quantitative data are not
available. It Is known that vast quantities of mine waste (particularly overburden) are generated annually by the coal industry. In fact, the
amount of nine watte produced annually by the coal Industry alone Is probably larger than the total amount of mine waste generated by all other
Industries combined.
M • Withheld to avoid disclosing Individual company confidential data
NA • Not applicable or values so small that no data were recorded.
Note: Metric conversion table In front matter.
-------
For the reasons stated above, the quantitative data
discussed in the following pages do not reflect the mine waste
produced annually by the coal industry. If this statistic were
known, the annual production of mineral resource waste would be
considerably larger than that estimated in this study and the
coal industry would be shown to be by far the major single
producer of solid waste.
Mineral resource waste figures in this report are based on
current ore-to-waste ratios and projected ore production
statistics, assuming that the ratio of ore to waste will remain
relatively constant. This assumption probably results in
underprojections because demand for products derived from mining
activities is likely to grow, and as higher grade ores become
depleted, it will become necessary to handle greater amounts of
material to meet these growing needs. Thus mineral resource
solid wastes are expected to increase in volume, not only because
of increased production, but also because of the need to treat
lower-grade ores. The degree to which the U.S. relies on ore and
concentrate imports in the future will also affect solid waste
production. (It should be noted that should ocean and oil shale
mining become major commercial enterprises, as is expected, the
amount of mineral resource solid waste generated annually could
double.)1
Calculations made in this study indicate that the mining
industry generated about 2.3 billion tons (2.1 Pg) of mine and
beneficiation wastes in 1975 (Table 7). By the years 1985 and
72
-------
2000 it is projected that the mineral mining industries will
produce between 4 and 6 billion tons (4.6 and 5.4 Pg) of solid
wastes annually. Sixty-eight percent of the mineral resource
solid wastes generated in 1975 were mine wastes, and 32 percent
were beneficiation wastes. If the wet weight of tailings (dry
weight plus weight of water used to slurry the tails) were
considered, total weight of tailings would surpass that of mine
waste, but this would be somewhat misleading because not all of
the water used to slurry tailings to settling ponds remains in
the ponds. That which is not entrapped in the tailings is
recycled back to the beneficiation plant, some is lost to
groundwater via seepage, some is evaporated, and the rest is
discharged into waterways.
Overburden associated with surface mining operations is by
far the largest source of mineral resource solid wastes,
comprising about 65 percent of the total produced in 1975
(Table 7). The total amount of solid waste (overburden and
tailings) produced at surface mining operations in 1975 was about
23 times greater than the quantity of waste generated at
underground mines.
• Tailings represent the major source of wastes at underground
mining operations, comprising about 80 percent of the annual
total. This is the reverse of the situation at surface mining
operations, where mine wastes make up the larger portion
(approximately 72 percent). Quantities of mine waste are low at
underground mines because after the initial developmental stages,
73
-------
most of the material extracted is ore. Relatively little waste
rock is removed during extraction.
Of the three mineral mining categories (metallic minerals,
nonmetallic minerals, and solid mineral fuels), metallic mineral
mining operations generate the most solid wastes (70 percent of
the total mineral resource solid wastes produced in 1975 as
opposed to 25 percent by the nonmetallic mineral industry and 5
percent by mineral fuels industry).* There are two general
reasons for the greater generation: many of the metallic
minerals are recovered from large open pit mines, and tremendous
volumes of mine waste must be removed to reach the ore; and
metallic mineral ores are of a lower grade than those in the
nonmetals and solid mineral fuels industries, making the
waste-to-product ratio much higher.
Although more than 65 different mining industries generate
solid waste, 5 of these are responsible for 85 percent of the
total (Table 7). Of these five, the copper industry contributes
the most, followed by the iron, phosphate, uranium, and bituminous
coal industries in that order.* The copper industry alone
produced more solid waste in 1975 than did all of the nonmetals
industries together. There is a definite relationship between
the states leading in the production of mineral resource solid
waste and the five major contributing industries. For example,
* This comparison does not consider the substantial
quantities of mine solid waste produced annually by the coal
industry.
74
-------
Arizona, which leads in the production of mineral resource solid
waste, is also the largest copper-producing state. Other states
that are major contributors to mineral resource solid waste are
Minnesota (iron mining), Florida (phosphate mining), Utah (copper
and uranium mining), Wyoming (bituminous coal and uranium mining),
and New Mexico (copper, bituminous coal, and uranium mining).
The quantities of solid waste generated at some individual
mining operations are staggering. For example, the Kennecott
Copper Corporation Bingham Canyon mine produces approximately 115
4
million tons (104.3 Gg) of waste rock and overburden each year.
Several copper beneficiation operations generate up to 50,000
tons (45.4 Mg) of tailings per day, and some operations are
approaching 100,000 tons (90.7 Mg) per day. Several tailings
dams 250 ft (76.2 m) high and a few 400 to 600 ft (121.9 to
182.3 m) high are planned. It is estimated that copper tailings
are generated at a rate of more than 100 million tons (90.7 Gg) a
year in Arizona alone, and accumulations in that State probably
exceed 4 billion tons (3.6 Pg). The same source estimates that
taconite tailings are being produced in Minnesota at the rate of
120 million tons (109 Gg) a year, and that accumulations
probably amount to 2 to 3 billion tons (1.8 to 2.7 Pg) across the
100-mile (190-km) length of the Mesabi taconite mining range
there.
The enormity of these values is best illustrated by the fact
that the New Cornelia tailings dam near Ajo, Arizona, is the
4
largest dam in the world in terms of the total volume of material.
75
-------
This dam contains an estimated 275 million cubic yards (210 Mm3)
of material, more than 50 percent greater than the second largest,
the Tarbela Dam in Pakistan. One researcher estimates that
enough copper tailings will be generated in the United States
between the years 1974 and 2000 to fill 100 square miles (2.06
2 7
Mm ) to an average depth of 170 ft (51.8 m).
In addition to the large volumes of wastes produced at
active mining and beneficiating operations, tremendous heaps of
mine wastes and tailings have been left behind at numerous
inactive mine sites across the United States. Although no
comprehensive national inventory has been made of total
accumulated solid wastes at these sites, some fairly complete
inventories by some individual states provide accurate solid
waste accumulation values. Although waste heaps associated with
inactive mine sites vary in size, they are usually much smaller
than the massive waste piles at active mining operations. When
considered as a whole, however, the waste heaps at these numerous
inactive sites represent a large volume of material, and because
they often are visible from major roads and highways, they can
seriously degrade the aesthetics of an area (Figure 14).
Attempts have been made to estimate the total accumulated
mineral resource solid wastes at both active and inactive mining
sites. The estimates vary depending on the number of mineral
industries included, the dates used as base years for initial
mineral production, and the method of calculation. An early
estimate indicated an accumulation of about 25 billion tons
76
-------
MINE WASTES
AND TAILING
Figure 14. This photo shows an example of mine
wastes and tailings at an inactive mine site.
-------
(22.7 Pg) by 1972. An estimate in a more recent document indicated
an accumulation of about 30 billion tons (27.2 Pg) by 1975.
Because these estimates are based on annual mineral resource
solid waste production statistics, it should be noted that they
do not actually represent the amount of waste deposited in mine
waste heaps and tailings ponds. As pointed out earlier, all of
the waste generated does not accumulate in waste heaps or
tailings ponds.
At many active mining operations, mineral resource solid
wastes disposal areas will eventually be rehabilitated or
reclaimed to some extent.* The amount of land being reclaimed
annually by mine operators in some states is actually greater
than the amount disturbed each year. In a few cases, lands that
were devastated by mining activities prior to the passage of
surface mining and reclamation legislation are being reclaimed.
Despite the fact that all mineral resource solid wastes do not
accumulate on the land and that substantial efforts are being
made by many industries to reclaim disposal areas, mineral
resource solid wastes still pose a threat to the environment for
the following reasons: (1) little was done before the late
sixties to control and rehabilitate waste disposal areas, and
large amounts of unstabilized wastes had already accumulated; (2)
in many cases there is no one to assume responsibility for the
* As of August 3, 1977, the Surface Mining Control and
Reclamation Act requires the coal mining industry to reclaim all
land disturbed by surface mining activities as well as land
disturbed by the surface effects of underground mining.
78
-------
large quantities of waste materials that have accumulated at
numerous inactive mine sites; (3) although they will eventually
be stabilized and reclaimed to some degree, some mineral wastes
being generated at active mines pose a threat to the environment
until such action can be taken.
Land Impacted by Mineral Waste Disposal
Substantial quantities of land have been disturbed by the
disposal of mineral resource solid wastes. According to the U.S.
Bureau of Mines, during the 42-year period from 1930 through 1971
the mining industry utilized* 3.65 million acres (14.8 Gm ) of
9
land. This figure does not include land disturbed by wastes
that have been eroded, transported, and redeposited by wind and
water. Of this total, about 38 percent was disturbed (directly)
by solid waste disposal, 59 percent by excavation, and the
remaining 3 percent by subsidence as a result of underground
workings. Of the total disturbed (directly) by waste disposal
2
[about 1.4 million acres (5.7 Gm )], 52.6 percent was by the
disposal of overburden and other surface mine wastes, 13 percent
by disposal of beneficiation wastes, and 5 percent by disposal of
underground mine wastes.
The U.S. Bureau of Mines has also estimated that about 40
2
percent of these 3.65 million acres (14.8 Gm ) has been reclaimed,
* "Utilized" here refers to lands that have been directly
impacted by the mining industry. Because the effect on adjacent
lands is not included, the figures presented do not include all
lands that were disturbed; they include only lands that were
utilized directly.
79
-------
but to an undefined extent.9 In 1971, 163,000 acres (660 Mm2) of
2
the 206,000 acres (834 Mm ) of land disturbed, or about 79 percent,
was reclaimed to some degree. Thus, the ratio of land reclaimed
to land used doubled in 1971 compared with the ratio for the 42-
year period average (Figure 15). About 30 percent of the land
reclaimed to some degree between 1930 and 1971 was waste disposal
land; about 68 percent was land impacted by excavation. These
figures may be influenced by variations in the definition of
"reclaimed."
The solid mineral fuel (coal) and nonmetal mining industries
each accounted for 43 percent of the directly used surface land
during 1930 to 1971, and the metal mining industry accounted for
the remaining 14 percent. On a commodity basis, the mining of
bituminous coal accounted for 40 percent of the total land used;
sand and gravel, 18 percent; crushed and broken stone, 14 percent;
clays and copper, 5 percent each; iron ore, 3 percent; and
phosphate rock, 2 percent. The commodities that require large
land usage also produce large volumes of solid wastes (Table 7);
however, the order of importance is different. For example, the
sand and gravel industry requires more land than any other
industry except coal, but ranks only seventh among leading
producers of mineral solid waste. Conversely, the copper
industry ranks fourth in land use (behind coal, sand and gravel,
and crushed stone), but it is the major producer of solid wastes.
The sand and gravel industry is made up of many more individual
excavated areas (mines) than the copper industry, but the ratio
80
-------
100
80
3,650,000 ACRES
206.000 ACRES
Z
LU
O
DC
LU
Q.
60
40
20
1,460,000 ACRES
UTILIZED RECLAIMED
1930-71
163,000 ACRES
UTILIZED RECLAIMED
1971
Figure 15. The ratio of land reclaimed by the
mining industry to that used doubled in 1971 compared
with the ratio for the 42-year period between 1930
and 1971.*
* Degrees of success of reclamation are essentially
omitted from this calculation. Thus the comparison of
ratios may be misleading in that reclaimed land
ultimately may be in a condition similar to unreclaimed
land.
Source: Paone, J., J.L. Morning, and L. Giorgetti. Land
utilization and reclamation in the mining
industry, 1930-71. U.S. Bureau of Mine
Information Circular IC8642. Washington, U.S.
Government Printing Office, 1974.
81
-------
of waste to marketable product is much lower than in the copper
industry.
In every state in the Union some land is being used to
dispose of mineral resource solid wastes. The mineral mining
2
industry has utilized 50,000 acres (202 Mm ) or more for solid
waste disposal in Pennsylvania, California, West Virginia,
Illinois, Ohio, Kentucky, Arizona, and Minnesota (in decreasing
order). Pennsylvania, West Virginia, Illinois, Ohio, and
Kentucky are the major coal-producing states; California is the
major producer of sand and gravel and crushed stone; Arizona
leads in the production of copper; and Minnesota leads in the
production of iron ore.
As a result of current and pending state and Federal
legislation (particularly the Surface Mining and Reclamation Act
of 1977), the ratio of land disturbed per year to land reclaimed
is expected to continually decrease. In addition, the quality of
land reclamation efforts is expected to increase because of the
more strict and more specific requirements of mining and
reclamation laws. The provisions in the Surface Mining Control
and Reclamation Act for rehabilitating abandoned mine lands will
also contribute to a decrease in the amount of land that has been
left disturbed by coal mining operations.
Characteristics of Mineral Resource Solid Wastes
The characteristics of mineral resource solid wastes are
described here because they influence such important factors as
(1) the potential environmental and health hazards associated
82
-------
with the wastes, (2) methods of waste disposal and stabilization,
(3) the potential for reprocessing the wastes or developing a
byproduct from them. This can best be illustrated by analyzing
their physical, chemical, and biological properties. These
analyses are followed by a description of mine and beneficiation
solid wastes resulting from these properties.
Physical Properties. The physical properties are color,
weight, and texture. The most important of these is texture,
which refers to the size, character, arrangement, and mode of
aggregation of the fragments, particles, or crystals that compose
a waste. Texture determines the physical structure and
appearance of the waste.
Size (used most frequently as an indicator of the texture of
a material) is determined by securing samples of waste, letting
them dry, weighing them, and then using appropriate sieves,
hydrometers, and/or counting devices to sort the material. If
some of the mineral resource waste particles are too large to
pass through the sieves, a standard rule is used to measure size.
Knowing the total weight in each particle size range makes it
possible to calculate the fractional percentage of each size
range and hence classify the vaste.
Chemical Properties. Chemical or mineralogic composition
is one of the most important properties of mine and beneficiation
solid wastes. It is a function of the presence of organic and
inorganic chemicals and organic matter (detritus, humus, etc.).
Knowledge of the chemical and mineralogic composition of a waste
83
-------
helps to determine (1) whether the wastes pose a potential threat
to the environment or to human health, (2) whether the waste will
support vegetative growth, (3) whether the waste materials can be
used as byproducts.
Before the chemical and mineralogic characteristics of a
waste can be determined, the elements and chemical compounds it
contains must be determined. The quantities or concentrations of
the materials contained in a waste are also important because the
manner in which chemical materials express their effects is
strongly influenced by their concentrations. For example, low
concentrations of some trace elements can cause the waste to be
nonsupportive of vegetative growth, whereas high concentrations
of certain trace elements may act as phytotoxicants. A further
complicating point is that the chemical constituents of a waste
interact with one another and the ultimate effects of these
materials are influenced by the manner in which they
interact—phosphorus at 40 ppm is beneficial to plant growth when
calcium is high (64 ppm), but it is toxic when calcium is low (8
ppm).10
It is also important to determine whether the chemical
elements and compounds in the waste are stable. Stability
determines whether a material is chemically active or inactive
(inert). Stable materials are basically inert or unavailable,
whereas unstable materials are chemically active or available.
The stability or availability of the chemical elements and
compounds in waste is determined largely by the solubility and
84
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reaction rates of these materials, which are influenced by pH and
the particle size or surface area of the wastes.
These interrelationships can be further explained by
analyzing the chemistry of a mineral resource waste that consists
of sulfide-containing materials such as pyrite. When a material
containing pyrite remains undisturbed in the earth, the pyrite is
relatively stable because the rock is in an oxygen-deficient
environment and because it is in large solid masses and not
intimately exposed to water. When the material is extracted and
deposited on the land in a waste dump, the pyrite becomes
reactive or unstable because it has been placed in an oxidizing
environment and can come in contact with water. The pyrite
reacts with oxygen and water, thereby producing an acidic
condition and lowering the pH. The solubility of some of the
chemical constituents of the waste increases as a result of the
low pH conditions, causing these materials to occur in greater
concentrations in water emanating from the wastes.
The waste materials in mine waste dumps and tailings
impoundments consist of a large size range of broken, crushed,
and ground particles that have resulted from blasting, extracting,
handling, and processing of large masses of rock. A decrease in
particle size results in an increase in surface area, which in
turn enhances the reaction rates of the chemical constituents
associated with the wastes.
As this discussion indicates, the reactivity or availability
of the chemical elements and compounds in a mine waste is a
85
-------
function of several interacting factors, such as pH, solubility,
and rate of reaction.
Another chemical property of interest is the availability of
water soluble salts in mineral resource wastes, such as those of
sodium and calcium. Because the salt content of a material
directly affects water availability to plants, it is important to
know the salinity of a waste when developing reclamation/
revegetation plans. Wastes that are highly saline hold water so
tightly (by increasing the osmotic pressure) that plants cannot
absorb it. In some heavily saline wastes, the osmotic gradient
can actually be reversed to such an extent that the waste
materials absorb water from the plant, thereby killing it
instantly. Heavy irrigation prior to revegetation is required to
dissolve and remove salts in order to alleviate this condition.
The salinity of mineral resource wastes influences other
chemical properties such as alkalinity, particularly if the salts
in the wastes are largely sodium salts. The percentage of cation
exhange capacity (CEC) attributable to sodium is a measure of its
alkalinity. When sodium accounts for more than 15 percent of the
total CEC, the waste material is alkaline. Mining wastes can be
alkaline, saline, or both. The waste is alkaline when sodium is
excessive; it is saline when the total salts are excessive.
As this discussion indicates, chemical characteristics of
mineral resource wastes are a function of several complex
interacting factors such as the kinds and concentrations of
chemical elements and compounds present and how they interact to
86
-------
control such properties of the wastes as acidity, alkalinity,
salinity, pH, reactivity, and solubility. These properties, in
turn, influence the potential environmental and health hazard
associated with mineral resource wastes because they have a
direct impact on such characteristics as toxicity, radioactivity,
reactivity, corrosiveness, and flammability.
Biological Properties. The biological properties of mining
wastes refer to the flora and fauna present. This parameter is
rarely measured or discussed because freshly deposited mining
wastes are almost void of flora or fauna, primarily for the
following reasons. Normal soils contain several chemically and
physically defined layers, which are typically referred to as the
A, B, and C horizons. The A horizon contains organic matter that
is being decomposed by bacterial and other biological action.
These processes (not fully understood) occur only in the A horizon
or topsoil material and are necessary for vegetative growth. In
the past, mining operations caused the soil and rock profiles to
be overturned; the soil horizons were buried and rocky overburden
was brought to the surface. More recently, some state regulations
and the Surface Mining Control and Reclamation Act have called
for topsoil to be removed separately and returned to the surface
<
for reclamation. Tailings disposal areas contain mostly ground
and processed bedrock mixed with some soil; therefore little
organic material and no defined soils are associated with tailings.
The chemical and physical properties of mineral resource
wastes will change naturally with time, and eventually fauna and
87
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flora will reappear. Because this occurs at an extremely slow
rate, most wastes require some form of amelioration (particularly
the return of topsoil) before they will support biological
activity.
Characteristics of Mine Wastes. Mine wastes (from both
surface and underground mines) constitute a mixed lot. The
properties of both surface and underground wastes depend on the
origin of the wastes and on such factors as climate, geographic
location, kind of mining activity, and method of disposal.
Because the physical and chemical characteristics of mine waste
heaps vary considerably from site to site, and because numerous
different mining industries are being addressed, only the most
general statements can be made about them in this document. The
biological properties of mine wastes do not vary as much as the
physical and chemical properties because most wastes are
essentially void of biota.
Mine solid wastes (overburden or underground waste rock) are
generated by extraction activities. Surface mining operations,
such as open-pit copper, iron, and uranium mines, generally
produce the most waste. The waste materials associated with
these and other metallic ores consist of glacial till,
unsegregated silts, clays, sand and gravel, and broken bedrock.
Although the wastes associated with nonmetallic ores are the
same, they contain less broken bedrock and more glacial tills,
clays, and sand and gravel. In the mining of some shallow
nonmetallic ores (e.g., sand and gravel, phosphate, and clay)
very little bedrock is encountered.
88
-------
The rock and soil materials in mine wastes can also vary
greatly in size (from large boulders to gravel and sand particles)
as a result of variations in ore formations and different mining
techniques. Generally waste materials associated with metal and
coal mining operations are larger than those associated with
nonmetal mining activities.
The chemical characteristics of mine wastes are even more
variable than the physical characteristics. They are a function
of the kinds of soils and host rock being removed in association
with ore extraction (Table 8). To understand fully the chemical
characteristics of the waste, factors such as pH, solubility, and
salinity must be considered.
The mine wastes associated with most nonmetal mining
operations usually do not contain chemical elements or compounds
that pose a serious threat to human health or the environment.
If potentially hazardous elements (such as heavy metals or
radioactive materials) are associated with these wastes, they
are usually inert or chemically stable because of pH and
solubility conditions. There has been some concern about
hazardous materials being associated with the mine wastes
generated by a few nonmetals mining industries. For example,
mine wastes from the few existing asbestos mines and one
vermiculite mine located in the West contain asbestos fibers.
Although human exposure to this material is unlikely to occur,
its inhalation is considered dangerous. Another example is the
overburden associated with central Florida phosphate mines, which
89
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TABLE 8
MINERALOGIC AND LITHOLOGIC SUMMARY OF MINERAL DEPOSITS*
Commodity
Metals
Aluminum
Antimony
Arsenic
Bismuth
Cadmium
Chromium
Cobalt
Copper
Gold
Iron
Lead
Ore
Bauxite
Stibnite
Ar sen ite
Bismuth
Greenockite
Chromite
Cobalt ite
Azurite
Born ite
Chalcocite
Chalcopyrite
Covellite
Enargite
Malachite
Calaverite
Native gold
Sylvanite
Hematite
Siderite
Anglesite
Cerussite
Galena
Rock type(s)
Igneous (residual)
Igneous, sedimentary
Igneous, sedimentary
Igneous, sedimentary
Sedimentary
Igneous, metamorphic
Metamorphic
Igneous, sedimentary
Igneous, sedimentary
Sedimentary, igneous
and metamorphic
Sedimentary, metamorphic
and igneous
Mineral and/or rock
Host rock material of mine waste
Syenite
Quartz veins
Quartz veins
Monzonites,
carbonates
(With zinc
minerals)
Per idotites
Metamorphic
Granitic rocks,
sandstone,
limestone
Quartz, volcanics
Shales, limestone,
sandstones, gneiss
and gabbro
Carbonates, shales,
quartzites, slates
Clays, soil, host rock
Host rock
Host rock
Host rock
?;ost rock
Host rock
Soil, host rock
Host rock
Soil, host rock
Host rock
Constituents of
mine waste
Aluminum, silicates
Quartz, sulfides
Quartz, sulfides
Barite, fluorite,
sulfides, iron oxides
Olivine, corundum
Host rock and minerals
Silica, pyrite
Host rock and sulfides
Barite, fluorite,
sulfides, oxides
(continued)
-------
TABLE 8. (continued)
Commodity
Manganese
Mercury
Molybdenum
Nickel
Platinum
Silver
Strontium
Thorium
Tin
Titanium
Tungsten
Uranium
Ore
Braunite
Manganite
Psilomelane
Pyrolusite
Rhodochrosite
Cinnabar
Molybdenite
Wulfenite
Pentlandite
Garnierite
Native
platinum
Argentite
Cerargyrite
Native Silver
Proustite
Strontianite
Thorianite
Cassiterite
Ilmenite
Rutile
Scheelite
Wolframite
Carnotite
Uraninite
(complex
oxide)
Rock type) s)
Igneous, sedimentary
and metamorphic
Metamorphic, sedimentary
Igneous
Igneous
Igneous
Igneous, sedimentary
Igneous, sedimentary
Igneous, sedimentary
Igneous, sedimentary
Igneous, sedimentary
Igneous, sedimentary
Igneous, sedimentary
Mineral and/or rock Constituents of
Host rock material of mine waste mine waste
Clays, limestone. Most rock, soil
schist
Slate, quartzite. Host rock, soil
limestone
Granite, monzonite Host rock
Quartz, diorite. Host rock
norite, green-
stones
Pyroxenites, Host rock
dunites
Quartz, quartzite. Host rock
volcanics
Marls, dolomite Host rock
Granite, sandstone Host rock
Granite, alluvium Host rock
Syenite, alluvium. Host rock
beach sands
Granite, alluvium Host rock
residium
Granite, phosphate Barren host rock
rock, shales,
sandstones
Impure host rock
minerals
Quartz, opal, pyrite
Fluor ite, sulfides.
iron oxides
Pyrrhotite, silicates,
oxides
Ferromagnesian
silicates
Quartz, barite.
manganese oxides, and
basemetal sulfides
Sulfur, gypsum
Silica, impure host
rock
Granite, quartz
Iron oxides, impure
host rock
Quartz, fluorite.
micas
Impure host rocks.
quartz, carbonates
(continued)
-------
TABLE 8. (continued)
ro
Commodity
Vanadium
Zinc
Nonmetals
Asbestos
Barium
Bentonite
Borate
Diatomite
Dolomite
Fluorspar
Garnet
Graphite
Gypsum
Ore
Patronite
(complex)
Carnotite
(vanadate)
Roscoelite
(mica)
Sphalerite
Smithsonite
Hemimorphite
Chrysotile
Barite
Montraorillo-
nite
Borax
Opal
Fluorite
Complex
silicates
Carbon
Gypsum
Rock type(s)
Sedimentary
Sedimentary, igneous
Metamorphic
Sedimentary
Igneous
Sedimentary
Sedimentary
Sedimentary
Sedimentary
Metamorphic
Metamorphic
Sedimentary
Mineral and/or rock
Host rock material of mine waste
Shales, limestone,
phosphate rock,
sandstones
Carbonates, gran-
itic rocks,
quartzites, slates
Serpentine
Barbonates, shales
Montmorilloni tic
Evaporites (salts)
Monomeneralic
Calcite, dolomite
Silicates
Schist, gneiss
Shales, clays
Barren host rock
Host rock
Host rock
Clays, soil, host rock
Shale, sandstone, clay
Clays, soil, alluvium,
host rock
Clays, soil, host rock
Host rock and related
types
Common sediments, host
rock
Host rock
Host rock, soil
Host rock, soil
Constituents of
mine waste
Mica, impure host
rare V minerals
rock
Pyrite, fluorite,
barite, impure host
rock
Magnesium, silicates
Calcite, quartz,
fluroite
Impure clay
Impure borates
Clays, sand, etc.
Host rock, barite
Silicates
Host rock, silicates
Anhydrite
(continued)
-------
TABLE 8. (continued)
ID
Commodity
Kaolin
Limestone
Magnesium
Nepheline
syenite
Olivine
Pegmatite
Phosphate
Potash
Quartz
Rock salt
Stone
(dimension)
Ore
Kaolinite
Limestone
Carnallite
Nepheline
Forsterite
Fayalite
Beryl
Feldspar
Lithium
minerals
Micas
Quartz
Rare earths
Apatite
Colophonite
Sylvite
Quartz
Halite
Granites
Marbles
Serpentine
Rock type(s)
Igneous (residual and
sedimentary)
Sedimentary
Sedimentary
Igneous
Metamorphic
Igneous, metamorphic
Igneous, sedimentary
Sedimentary (e vapor ites)
Igneous, sedimentary
Sedimentary
Igneous, metamorphic,
sedimentary
Mineral and/or rock
Host rock material of mine waste
Granite (residium)
and common clays
Dolomite
Monomineralic
Dunite
Granite, schist
Phosphorite, quano,
apatites
Shales, clays
Granitic rocks,
alluvium
Common sediments
Granite, marble,
conglomerate,
sandstone
Host rock, soil
Host rock, soil and
related types
Host rock, soil
Host rock, soil
Host rock, soil
Host rock, soil
Host rock, clays, sand,
soil
Host rock
Host rock, clays, soil
Host rocks and related
types
Host rock (impure)
Constituents of
mine waste
Silicates, impure
clays, iron oxides
Impure limestone,
iron oxide
Impure host rock
minerals
Biotite, hornblende
Iron and magnesian
silicates
Host rock, impurities
biotite, hornblende,
iron oxides
Limes, silica, iron
oxides, uranium
oxides, clays
Impure e vapor ites
Iron oxides, calcite
clays
Impure salts,
anhydrite, gypsum
Impure host rock
(continued)
-------
TABLE 8. (continued)
10
Commod i ty
Sulfur
Talc
Mineral Fuels
Coal
Ore
Native sulfur
Pyrite
(Steatite)
(Soapstone -
fine
crystalline)
Anthracite
Bituminous
Lignite
Rock type(s)
Igneous, sedimentary
Metamorphic
Metamorphic
Host rock
Common sediments,
volcanics
Altered limestone,
serpentine,
gneiss, schist,
slate
Shales, limestone
Mineral and/or rock
material of mine waste'
Most rock
Host rock
Host rock, soils, clays
Constituents of
mine waste
Salts, anhydrite,
sulfides, etc.
Silicates
Limestone, shale,
pyr ite
* Adopted from Table 3 of Water pollution caused by inactive ore and mineral mines - a national assessment.
EPA-600/2-76-298. Prepared by Toups Corporation. Santa Ana, California. Prepared for Resource Extraction
and Handling Division; Industrial Environmental Research Laboratory; Cincinnati, Ohio. December 1976.
-------
contains some radioactive constituents. These radioactive
materials do not pose a serious threat to ground and surface
waters because they are not soluble at mine water pH, but they
can be carried into the atmosphere via fugitive dust. These
materials are placed at the toe of overburden piles and
subsequently buried as a precaution against this occurrence.
The chemical characterisitcs of mine wastes associated with
coal and metals mining are more complex and pose a more serious
threat to the environment than those generated by the nonmetals
mining industries. Mine wastes from eastern coal mines commonly
contain unstable sulfide minerals (e.g., pyrite and marcasite),
and the leachate produced by these minerals upon interaction with
water is acidic in nature. In contrast, wastes from western coal
mines, which ordinarily do not contain pyrite, tend to be
alkaline, have a high pH, and contain a different variety of
dissolved materials (primarily salts). Although the concentrations
of the salts vary, they are usually sufficient to present a
problem. The overburden and waste rock removed during the mining
of some metallic ores (e.g., copper, lead, and zinc) in the West
also contain pyrite; hence where oxygen and water are available
together, these wastes produce acid water similar to that
produced by eastern coal mine wastes. Because these wastes also
contain heavy metals, the acid leachate formed contains dissolved
metals that are hazardous to the environment. In the Central
Rocky Mountains, copper, zinc, and arsenic are almost always
associated with mine drainage.
95
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Most mineral resource solid wastes are void of flora and
fauna because they generally contain little organic matter and
few nutrients, have no defined soil layers, retain little
moisture, and sometimes contain toxic elements. Natural
amelioration of the waste materials does occur and some biota
will reappear, but this is an extremely slow process.
In general, the characteristics of mine solid wastes
associated with inactive mine sites are similar to those
associated with wastes at active sites. With time, physical and
chemical weathering decreases the particle size of the waste
materials, wastes that were chemically stable when deposited
remain stable, and those that were unstable become more stable.
Because natural amelioration of some wastes occurs, biota will
have reappeared in some cases; however, in other cases wastes
will still be almost completely void of biological activity as a
result of extremely adverse chemical and physical conditions.
Characteristics of Beneficiation Solid Wastes. The physical
and chemical characteristics of tailings are largely a function
of the kinds and amounts of impurities associated with the ore,
the mineral processing techniques used, and the degree of
difficulty in separating the ore from the rock. Tailings consist
essentially of finely crushed rock; therefore the mineralogical
composition generally corresponds to that of the host rock from
which the ore was derived (Table 8).
Tailings normally contain various mixtures of quartz,
feldspars, carbonates, oxides, ferromagnesian minerals, and minor
96
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12
amounts of other minerals. They also contain traces of the
reagents that are added during beneficiation. The physical and
chemical characteristics of tailings vary even more than those of
mine wastes. The biological characteristics do not vary because
unrestored tailings are almost always void of biological activity,
Tailings are usually the major solid waste of concern from
an environmental and health effects standpoint. For ease of
presentation, the physical and chemical characteristics of
tailings are discussed on an industry basis. Because all the
many industries cannot be discussed, certain ones were selected
on the basis of the volume of tailings they generate and/or the
importance of the materials contained in them.
Copper Tailings. Copper tailings consist of sand, silt,
and clay-sized particles. Clay minerals normally are absent.
Virtually all of the tailings are soil-sized particles, ranging
4
from 10 to 270 mesh. Some -270-mesh particles are found in
copper tailings but their quantity is, small. One operator
reports copper tailings containing approximately 45 percent
solids by weight, and particle size distribution ranging from
4
about 15 percent +65 mesh to 55 percent -200 mesh. Copper
tailings generally consist of hard angular particles. According
to Volpe, most copper tailings are nonplastic, their specific
gravity values range from 2.64 to 2.78, and they exhibit
12
uniformly high shear strength.
Although the chemical composition of copper tailings varies
with location, most are basically a siliceous material with trace
97
-------
amounts of copper and other heavy metals. Age is a major
contributing factor to their variation. For example, most
freshly deposited copper tailings are alkaline; however, aging
and weathering processes produce a sharp decline in pH, probably
because of the biochemical oxidation of pyrite with the subsequent
formation of sulfuric acid. Concentrations of soluble salts,
which can be quite high in some tailings, are also affected by
time. Rainwater dissolves the salts, and if the tailings are
adequately permeable, natural weathering processes will
substantially reduce their concentration in most copper tailings.
Taconite and Iron Ore Tailings. Taconite tailings are
nearly 100 percent soil-sized particles (mostly sand and silt;
little clay). Particle diameter ranges between 0.02 and 5 mm,
and fragments are generally sharp and angular. Chemically,
taconite tailings are predominantly siliceous and rich in iron,
but low in alkali. Nonetheless, these tailings are generally
alkaline. Recently, controversy has arisen in Minnesota over
the presence of asbestos-like fibrous particles in taconite
tailings. These fibers are reported to be present only in
taconite ores from the eastern portion of the Mesabi range.
The beneficiation of high-grade iron ores produces both
coarse and fine tailings. In Minnesota, these tailings are
usually separated on a 1/4-in. (6.35-mm) screen. They vary in
mineral character and generally contain enough residual iron to
be black in color. They are considerably less siliceous than the
taconite tailings and contain higher percentages of iron. The
98
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tailings generated by the beneficiation of high-grade ores in
Minnesota show an iron content of as high as 25 to 35 percent.
Lead-Zinc Tailings. Lead and zinc, recovered primarily from
sulfide-bearing ore minerals, are normally found as coproducts in
dolomitic or limestone parent rocks. Tailings are separated from
lead-zinc ores by grinding and flotation. The tailings that once
were generated by jigging and tabling were coarser than those
produced by flotation. Most jig tailings have been recovered and
reground for secondary recovery by flotation; however, some jig
tailings are still scattered around mountain valleys in the West.
Tailings from lead-zinc operations are separated into coarse
and fine fractions. Lead-zinc tailings generated by operations
in northwest Illinois consist of -9/16-in. (-14.2-mm) washed
14
dolomite gravel and -48 mesh flotation sand. Lead-zinc
operations in Tennessee also separate tailings into a coarse
[1-3/4-in. (45.4-mm) to 1/4-in. (6.35-mm)] and fine (-20 mesh)
fraction. At mining operations in some states (e.g., Missouri,
Pennsylvania, Colorado, Idaho, and Washington), tailings are
separated when sandfilling is utilized. The coarse fraction is
placed back in the mine and the slimes are sent to the tailings
pond.
It is difficult to generalize about the chemical composition
of lead-zinc tailings because it varies with geology. Emery and
Kim report that the tailings at a Gilman, Colorado, operation
contain from 65 to 75 percent pyrite (which would render this
material acidic in nature). The tailings produced at a Boss,
99
-------
Missouri, operation on the other hand, are composed essentially
of calcium and magnesium oxides. Leachate from some lead-zinc
tailings piles contains lead and zinc as well as such metals as
4
copper, iron, nickel, selenium, and antimony.
Uranium Tailings. Uranium tailings normally occur as fine
to medium sands. When upstream construction is utilized, the
coarser sand materials settle first and the lighter slimes last
as the tailings are discharged to the impoundment. At one
uranium beneficiating operation, the size distribution of the
sand portion of the tailings (which is about 70 percent of the
solids) was reported to be 3 percent +28 mesh, 40 percent +65
mesh, 70 percent +100 mesh, and 100 percent +200 mesh. Most
of the sand portion is deposited along the outer rim of the
disposal areas. The size distribution of the slimes portion
(about 30 percent of the solids) is 33 percent -200 mesh to +325
mesh and 67 percent -325 mesh. This material is deposited near
the rear of the ponds and around the decant points. Uranium mill
tailings are too coarse to prevent seepage, regardless of
separation techniques. Consequently, the Nuclear Regulatory
Commission requires that the ponds be lined prior to licensing.
The main chemical constituents of concern in uranium
tailings are the radioactive materials (radium, uranium oxides,
thorium, and radon gas). The 30 percent slimes contain about 80
percent of the radiation values, whereas the 70 percent coarse
sand contains only 30 percent. Wind erosion of uranium
tailings is of particular concern because of the radioactive
100
-------
materials associated with them. Havens and Dean report that
exposures above the radiation protection guide value of 0.05
rem/year can be absorbed downwind of uranium tailings.
Gold Tailings. At one mining operation gold tailings are
reported to be fine, sharp-edged, jagged particles, which are
very abrasive. The size distribution is reported to be:
Sieve size, mesh Passing, percent
80 99.0
100 97.6
150 94.6
200 90.3
270 82.4
325 72.1
The chemical composition of the tailings was reported to be:
Si(X 52.8 percent
Al«03 1.6 percent
FeO 34.0 percent
MgO 8.2 percent
MnO 0.5 percent
CaO 1.0 percent
Na 0 0.5 percent
Some gold beneficiation operations use sodium cyanide as a
processing reagent, and some of this material ends up in the
101
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tailings. The discharge of cyanide is regulated by the NPDES
permit system, but seepage, which could contain some of this
material, is unregulated.
Molybdenum. The Climax Molybdenum Company has recorded the
grain size distribution of molybdenum tailings for their Urad,
Climax, and Henderson mines (Table 9). The size of the particles
4
ranges between 14 and 400 mesh. The chemical and mineralogical
compositions of the tailings generated at the Henderson and
Climax operations are as follows:
Henderson Mine Climax Mine
(percentages)
Quartz
Aluminum Oxide
Ferric Oxide
Ferrous Oxide
Magnesium Oxide
Calcium Oxide
Sodium Oxide
Potassium Oxide
75 - 80
7-12
0.2 - 3
-V 1
^ 0.1
0.12 - 1
0.5 - 4
4-8
Plagioclase
Mica
Pyrite
Clay minerals
Fluorite
Limonite
Calcite
Magnetite
Topaz
Rutile
The presence of iron pyrite in the tailings produced at the
Climax operation makes the tailings somewhat acidic.
Quartz 35 - 45
Alkali feldspar 18 - 23
13 - 17
4-6
4-6
4-6
2-4
1-3
1-3
0.5 - 1.5
0.5 - 1.5
0.5 - 1.5
102
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TABLE 9
GRAIN SIZE DISTRIBUTION OF MOLYBDENUM TAILINGS AT
THE CLIMAX MOLYBDENUM COMPANY MINES*
(percent fines by weight)
Sieve
size Henderson
(mesh) Mine
14
20
28
35 97
48 90
65 76
100 65
150 54
200 35
270§
325§
400§
Climax
Mine
99.8
99.5
98.5
95.8
89.5
81.1
70.7
60.3
50.0
44.2
41.5
35.5
Urad
Minet
88
78
66
55
48
42
38
35
* Offices of Research and Development. Availability of
mining wastes and their potential for use as highway material,
v. 1, 2, and 3. Federal Administrative Report No. FHWA-RD-76 106,
Washington, 1976.
t The Urad Mine has been recently closed.
§ U.S. Sieve series number.
103
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Phosphate. The beneficiation wastes associated with
phosphate ore processing consist of two separate fractions: sand
tailings and waste fines (or slimes). Sand tailings particles
range from 16 to 150 mesh, which is in the range of a fine to
4
medium sand. They are composed of 90 percent quartz sand, 8
percent carbonate fluorapatite, and 2 percent feldspar and heavy
minerals.
Grain size distribution of phosphate slimes, which are
essentially colloidal clay particles, varies by location because
of differences in the nature of the matrix being mined and in
beneficiation methods. A typical slime particle is -0.003 in.
(-0.1 mm) in diameter, and more than 70 percent of the particles
4
are less than 1 ym. The slimes are usually 2 to 6 percent
solids when slurried to an impoundment. Because of their
colloidal particle size, the settling rate of slimes is very
slow; solids contents are often no more than 20 percent after
18
years of settling.
These clay-like waste slimes contain a substantial amount of
phosphate mineral. Analysis of phosphate slimes in central
Florida shows them to be composed primarily of carbonate
fluorapatite, montmorillonite, and quartz, with lesser amounts of
18
kaolinite, attapulgite, and feldspar.
Coal Tailings. Coal tailings (commonly called refuse in the
industry) are those wastes generated by coal cleaning or
preparation. These tailings are typically classified as coarse
4
or fine; the dividing point is usually the No. 4 sieve.
104
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Coarse tailings normally comprise about 70 to 80 percent by
weight of the total tailings. The remaining 20 to 30 percent (a
silt or slurry) is removed during washing and pumped to an
impoundment or slurry pond.
Coarse tailings associated with the preparation of anthracite
and bituminous coals are similar in appearance. They are a dark
gray and are composed largely of slate or shale particles
intermixed with some coal and varying amounts of pyrite. Some
bituminous tailings also contain grayish rock, which, when
disposed of, will weather and decompose into silt or soil-size
4
particles within a few days to a week. The percentage of
carbonaceous material is normally rather high in older refuse
banks because efficient cleaning or preparation plants were not
available in the past. Because these high concentrations of
carbonaceous material (coupled with poor disposal practices) have
resulted in numerous fires, some of these banks contain some
reddish-colored incinerated material called "red dog."
Anthracite and bituminous tailings are markedly similar in
appearance. Coarse refuse varies widely in size, consisting of a
mixture of rock, flat shale or slate particles, some coal, and
varying amounts of pyrite. Anthracite and bituminous coal waste
slurry (fines) are somewhat similar in size and appearance to
the fine beneficiation tailings for other minerals previously
described.
Several investigations have been made to ascertain the
physical properties of coarse and fine coal tailings. Some of
105
-------
the more recent studies, by the U.S. Bureau of Mines Spokane
Mining Research Center and Michael Baker, Jr., Inc., show that
coarse coal tailings are well graded, and nearly all particles
are less than 4 in. (101.6 mm) . ' ' These studies also
indicate that fine tailings are more uniform in gradation than
coarse tailings.
Results of other laboratory tests to determine other
physical factors, such as specific gravity, permeability, and
shear strength, indicate that the density, permeability, and
shear strength of coarse coal tailings are fairly uniform after
the tailings are compacted to their maximum dry density and that
19 20 21
they are quite stable if properly compacted. ' ' The same
physical properties and field moisture conditions of coal slurry
combine to make deposits of this material unstable with very
little strength-carrying capability.
Chemical characteristics of coal tailings vary according to
the mineralogy of the deposit, the efficiency of the preparation
plant, and the method of disposal. Most coal tailings in the
eastern United States contain some pyrite and marcasite, and the
leachate from these minerals is acidic in nature. Pennsylvania
State University recently investigated a number of anthracite
tailings disposal sites and determined that the pyrite content foj
all materials tested ranged between 3.0 to 4.4 percent pyrite.
Results of U.S. Bureau of Mines tests of coarse coal
tailings indicate that the predominant components of the waste
18
are iron, magnesium, potassium, and sodium. The Bureau's tests
106
-------
of fine tailings indicate that they contain 60 percent silica
(SiO_), 25 percent alumina (Al 0,), and 7 percent iron oxide
(Fe203).18
Beneficiation Wastes at Inactive Mine Sites. As at active
sites, the characteristics of tailings associated with inactive
mine sites vary as a function of (1) mineralogy of the deposit
that was mined, (2) beneficiation method, (3) disposal method.
Because the mineralogy of the deposit mined has the greatest
influence, copper tailings at an abandoned site would exhibit
some similar physical and chemical properties to those at an
active site. Tailings at inactive sites sometimes contain higher
concentrations of chemical materials (e.g., heavy metals,
sulfates) because former beneficiation methods were less
efficient. Generally, most tailings that are chemically stable
when deposited remain stable, and those that are unstable slowly
stabilize with time. Some tailings, however, do become more
unstable with time, as chemical and physical weathering and
biochemical reactions expose additional materials and make them
available to react chemically.
107
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REFERENCES FOR SECTION 3
1. Office of Solid Waste Management Programs. A comprehensive
assessment of solid waste problems, practices and needs.
Prepared by AD Hoc Group for Office of Science and
Technology, Executive Office of the President, Washington,
May 1969.
2. Dean, K.C., and R. Havens. Methods and Costs for Stabilizing
Tailings Ponds. Presented at the American Mining
Congress Mining Convention/Environment Show, Denver,
Colorado, September 9-12, 1973.
3. U.S. Environmental Protection Agency. Development document
for interim final and proposed effluent limitations
guidelines and New Source Performance Standards for the
mineral mining and processing industry, point source
category. U.S. Environmental Protection Agency Publication
440/l-76/059a, Group II. Washington, U.S. Government
Printing Office, 1976.
4. Collins, R.J., and R.H. Miller. Availability of mining
wastes and their potential use as highway material -
v. 1 - Classification and technical environmental analysis,
prepared for Federal Highway Administrator, Offices of
Research and Development. Report No. FHWA-RD-76 106 by
Valley Forge Laboratories, May 1976.
5. Donovan, R.P., R.M. Felder, and H.H. Rogers. Vegetative
stabilization of mineral waste heaps. EPA-600/2-76-087,
Research Triangle Institute for Industrial Environmental
Research Laboratory, Office of Energy, Minerals, and
Industry, Environmental Protection Agency, Research
Triangle Park, North Carolina, April 1976.
6. Mining Enforcement and Safety Administration. Mine refuse
impoundments in the United States. MESA Informational
Report 1028. January 1977.
7. Office of Assistant Director - Mining. Bureau of Mines.
U.S. Department of the Interior. Evaluation of mill tailing
disposal practices and potential dam stability problems
in southwestern United States. General Report, v. 1.
Report No. BuMines OFR 50(1)-75. Washington, D.C. 1974.
8. Office of Research and Development. Water pollution caused
by inactive ore and mineral mines, a national assessment.
U.S. Environmental Protection Agency Publication
600/2-76-298. Washington, U.S. Government Printing
Office, 1976.
108
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9. Paone, J., J.L. Morning, and L. Giorgetti. Land utilization
and reclamation in the mining industry, 1930-71. U.S.
Bureau of Mines Information Circular IC8642. Washington,
U.S. Government Printing Office, 1974.
10. Treshow, M. Environment and plant response. McGraw Hill
Book Co., New York, 1970.
11. Office of Air and Water Programs. Methods for identifying
and evaluating the nature and extent of nonpoint sources
of pollutants. U.S. Environmental Protection Agency
Publication 430/9-73-014. Washington, U.S. Government
Printing Office, October 1973.
12. Volpe, R.L. Geotechnical Engineering Aspects of Copper
Tailings Dams. Presented at the American Society of
Civil Engineers National Convention, Denver, Colorado,
November 3-7, 1975.
13. Dean, K.C. Utilization of Mine, Mill, and Smelter Wastes.
Proceedings; First Mineral Waste Utilization Symposium:
Chicago, Illinois, March 27-28, 1968.
14. Drake, H.J. and J.E. Shelton. Disposal of Iron and Steel
Slag. Proceedings; Fourth Mineral Waste Utilization
Symposium. Chicago, Illinois, May 4-8, 1974.
15. Emery, J.J., C.S. Kim, and R.P. Cotsworth. Base
stabilization using palletized blast furnace slag.
American Society for Testing and Materials, Journal of
Testing and Evaluation, vol. 4, No. 1, January, 1976.
16. Personal Communication. Robert G. Beverly, Dirctor of
Environmental Control, Union Carbide, to Jack Greber,
PEDCo. February 8, 1978.
17. Havens, R. and K.C. Dean. Chemical stabilization of uranium
tailings at Tuba City, Arizona. U.S. Department of the
Interior, Bureau of Mines, 1969.
18. U.S. Department of the Interior, Bureau of Mines. The Florida
phosphate slimes problem: a review and bibliography.
U.S. Bureau of Mines Staff, Washington. Information
Circular No. 8527, 1971.
19. Busch, R.A., R.R. Backer, and L.A. Atkins. Physical property
on coal waste embankment materials. U.S. Department of
the Interior, Bureau of Mines, Report of Investigations
No. 7964, 1974.
109
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20. Busch, R.A., R.R. Backer, L.A. Atkins, and C.D. Kealy.
Physical property data on fine coal refuse. U.S.
Department of the Interior, Bureau of Mines, Report of
Investigations No. 8062, 1975.
21. Baker, M., Jr., Inc. Investigation of mining-related
pollution reduction activities and economic incentives in
the Monongahela River- Basin. Report to the Appalachian
Regional Commission, April 1975.
22. Luckie, P.T., J.W. Peters, and T.S. Spicer. The evaluation
of anthracite refuse as a highway construction material.
Pennsylvania State University, Special Research Report
No. SR-57, July 30, 1966.
110
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SECTION 4
RECLAMATION—DISPOSAL, STABILIZATION, AND CONTROL
With a few exceptions, technology is well established for
disposal of the over 2 billion tons (1.8 Pg) of mineral resource
solid wastes generated annually. It is also well established for
the stabilization of these wastes to protect the public and for
the control of air and water-pollutants. Overburden generated
by surface mining and waste rock generated by underground mining
are usually placed in waste piles or backfilled into areas
previously excavated during the mining operation. Tailings
generated by beneficiation operations (at both surface and
underground mines) are usually disposed of in tailings ponds.
Techniques are available to control seepage from and leaching of
these deposits. Because the extent to which these proven
/
technologies are applied varies considerably by geographic
location and type of mining industry, there are areas where the
control measures now being used are insufficient to protect human
health and the environment. This particularly applies to
abandoned mine sites.
A variety of proven technologies are available for providing
structural stability for tailings dams and overburden/waste rock
piles; for preventing the evolution of excessive fugitive dust
from tailings pond slopes, inactive tailings, and overburden/
111
-------
waste rock piles; for preventing both surface and groundwater
pollution from tailings ponds and overburden/waste rock piles;
and for ultimately creating a reclaimed area that is functionally
2
and aesthetically satisfactory.
Currently viable disposal, stabilization, and control
methods are described and discussed in the following pages
according to type of solid waste (Table 10).
Site Selection and Mine Design
Although this section deals primarily with reclamation of
land at active and abandoned mine sites, it also covers measures
that can be taken prior to developing new mining areas to ensure
minimal adverse environmental impact. Planning and design can
transform a potentially unsuitable area into a safe site for
2
solid waste disposal. Careful site selection can minimize the
engineering costs of transforming an unsuitable site into a
usable one.
Initial feasibility investigations of a mining and/or
\
beneficiating facility must consider the fate of the solid waste
that will be generated. In the past the primary concern was to
locate one or more areas of acceptable size near the production
site. Recently, however, new variables such as environmental
regulations and greater concern for public safety have been
introduced into the site selection process. These variables are
intended (1) to protect groundwater from degradation by leachates
emanating from and passing through overburden and waste rock
piles and tailings, (2) to protect surface water from silt loads
112
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TABLE 10
METHODS EMPLOYED FOR THE DISPOSAL, STABILIZATION, AND CONTROL
OF SOLID WASTES GENERATED BY MINING/BENEFICIATING OPERATIONS
Type of solid waste
Disposal method
Stabilization/control method
Overburden (surface mining) and
waste rock (underground mining)
U>
Tailings from the mills of both
underground and surface mines
(continued)
Stockpiles adjacent to surface and under-
ground mines and on the outside slopes of
open pit mines.
Backfilling of previously excavated areas
adjacent to the active overburden removal
at surface mines (block-cut/box-cut mining
method). Backfilling of underground mines
with waste rock.
Utilization as construction material (e.g.,
tailings dam or embankments, highway con-
struction) .
Tailings pond.
Maintenance of an angle of repose to prevent
landsliding and/or excessive slope erosion.
Employment of physical (e.g., contouring inter-
ceptor ditches, windbreaks, watering), chemical
(wetting and crusting agents), and vegetative
surface stabilization techniques to control
surface water and fugitive dust pollution.
If pyrite is present in the overburden, separ-
ation and isolation of the overburden in order
to prevent the emission of the associated
hazardous wastes (heavy metals and the corro-
siveness associated with the acid water
produced).
Employment of physical (windbreaks and water-
ing) , chemical (wetting and crushing agents),
and vegetative surface stabilization technique*
to control surface water and fugitive dust
pollution at surface mines. Not generally
applicable to open pit. copper mining.
Nothing additional required at underground
mines.
Minimal stabilization/control required, except
for suppression of fugitive dust during trans-
fer and handling.
For new facilities, conduction of preliminary
site evaluations for ultimate selection of a
location with the least adverse impact on the
environment (if practical, a site with an
impervious material base or with an underlying
aquifer sufficiently depressed to prevent
groundwater contamination, and one which is
removed from accumulation of surface water
runoff).
Construction of the tailings dam and embank-
ments by prescribed engineering design
practices to ensure structural stability.
If the material under a tailings pond has a
saturated hydraulic conductivity greater than
Id"' cm/s, sc.ilinn rlio hot torn aru! inner slopes
of the pond to prevent contamination is nect-;s-
:;aiy if the pond contains hazaitlous wastes such
.is pyrite-rich tailings.
-------
TABLE 10. (continued)
Type of solid waste
Disposal method
Stabilization/control method
Backfilling underground mines (either by
sluicing or truck hauling)
Elimination or minimizing of tailings pond dis-
charge to surface streams through (1) recycle
of water for sluicing at mill, (2) maintaining
sufficient freeboard on dam, (3) maximizing
pond surface area (through site selection) to
maximize evapotranspiration.
Where elimination of tailings pond discharge to
surface streams is impractical, treatment of
tailings pond to produce an effluent which
meets pertinent water quality standards (e.g.,
addition of lime to aid solids settling and
adjust pH, provision of sufficient retention
time and length-to-depth ratio to allow the re-
quired solids settling time).
Employment of physical (windbreaks, intercep-
tor ditches and watering), chemical (wetting
and crusting agents), and vegetative surface
stabilization techniques on tailings dam and
embankment slopes and on dry, inactive areas
of tailings ponds to prevent surface water and
fugitive dust pollution.
Ensure that potential hazardous tailings sluice
water does not make contact with an Infiltra-
tion gallery to a subterranean aquifer.
when dry tailings (such as coal gob piles) are
used to backfill underground mines, suppression
of fugitive dust from transfer and handling of
the material.
(continued)
-------
TABLE 10. (continued)
Type of solid waste
Disposal method
Stabilization/control method
Ul
Miscellaneous wastes. Includes
mine site development wastes
(e.g., drilling muds, scalped
vegetation), construction debris,
and domestic garbage from food
consumed on site.
Utilization as construction material (e.g.,
tailings clam or embankments, mining haul
roads, aggregate for asphalt paving mate-
rial and concrete for highway and building
construction) and as agricultural additive
as a fertilizer filler or supplement.
Combination with overburden, waste rock,
and/or tailings.
Separate disposal in sanitary landfill on
or off site.
Lake/marine disposal
Minimal stabilization/control required, except
for suppression of fugitive dust during trans-
fer and handling.
Minimal stabilization/control methods required
in addition to those prescribed above.
Periodic coverage of garbage with inert mate-
rial not subject to emission of fugitive emis-
sions (similar to prescribed sanitary landfill
methodology) .
Very little can be done prior to or after dis-
charge of the tailings to the lake or marine
environment. Isolation of the lake from dis-
charge to surface streams is possible, but not
often practiced.
-------
and dissolved solid loads generated by erosion and corrosion of
these wastes, (3) to prevent these wastes from generating
fugitive dust, (4) to protect human life from catastrophic
failure of tailings dams, etc. caused by floods or seismic
events.
To guarantee such protection, other variables, including
topography, hydrogeologic environment, availability of appropriate
construction materials, hydrology, seismic conditions, direction
and velocity of prevailing winds, and frequency and intensity of
precipitation (atmospheric conditions), must also be considered.
Proper evaluation of so many variables requires an
interdisciplinary approach to the selection of disposal sites for
large volumes of mineral resource solid wastes, even though the
evaluation of all the variables is not required for some wastes.
Modern legal and social constraints make it impossible for a
single engineer or geologist to accomplish the site selection in
a manner that precludes unanticipated postconstruction expenditures
2
for corrective measures.
The following are some of the guidelines to be considered
where applicable:
Topography.
0 Roads in disposal areas should be fitted to the
topography to keep alterations of natural conditions at
a minimum.
0 To the extent feasible, overburden and waste rock piles
should be designed to blend with the natural topography.
0 Alteration of topography should be designed to divert
all drainage away from waste piles and tailings ponds.
116
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Hydrogeology. It may be necessary to employ bore holes and
geophysical methods to determine the following:
0 Location and depth of bedrock, unconsolidated materials,
and groundwater flow system.
0 Grain size distribution, permeability, and engineering
properties of the unconsolidated materials (so that
potential settlement, leakage, and other failure
problems can be anticipated and corrective measures
incorporated into the design of the disposal facility).
0 Groundwater flow system characteristics and background
water quality.
Faults and landslides should be identified so that failure-prone
areas can be avoided if accidental release of the material to be
discarded constitutes a hazard to health or to the environment
(e.g., location of a tailings dam over a fault area can be
avoided).
Construction Materials for Tailings Ponds.
0 Exploration should include pitting, trenching, and
drilling to determine the location, characteristics,
and quantities of potential materials of construction
(including mine rock and naturally occurring materials).
0 Materials for the tailings pond embankment should be
selected critically to ensure that the coarsest,
strongest, least compressible, and most permeable
material available is used for maximum stability and
controlled seepage.^
0 Slimes should be placed as far away from the outer
embankment as possible.
Failure to follow these guidelines concerning construction
materials could result in a catastrophic failure such as the
recent collapse of a tailings dam at Buffalo Creek, West Virginia.
117
-------
Hydrology. Data on water quality and quantity should be
acquired. Precipitation, runoff, and stream-flow data are used
to determine the following:
0 Amount of freeboard that must be maintained on the dam
if the tailings pond is located in a draw.
0 Size of diversion system required to handle peak flows
if they are so great that the dam must be bypassed or
if the quality of the water behind the dam is so poor
that it cannot be allowed to enter a stream.
0 Design of the dam's spillway.
0 Design of the dam itself, especially if the waste is
placed in a draw, a gently sloping sidehill, a
horizontal plateau, or a large valley bottom.
Meteorological Conditions. Data should be acquired to allow
for the following:
0 Proper design of erosion measures such as slope angle.
0 Revegetation program planning.
Wind direction and velocity data should also be acquired so as to
avoid sites that are upwind from the prevailing wind direction of
towns, recreational areas, and farm lands when the waste piles
are expected to generate considerable amounts of fugitive dust
despite conscientious application of dust-suppression techniques.
Disposal of Overburden and Waste Rock
It is estimated that 90 percent of the overburden and waste
rock (soil, sand, clay, shale, gravel, boulders, and other
unconsolidated materials) removed to gain access to an ore body
4
is disposed of in stockpiles near or adjacent to the mine.
Overburden from open pit mines is usually discarded on the
outside slopes of the pit. For many years overburden and waste
118
-------
rock have been disposed of (in unique situations) by immediately
backfilling previously excavated areas (stopes in underground
mines) as part of the normal mining process, particularly in the
lead and zinc mines in Idaho; in most.underground mining operations,
however, backfilling is not considered an acceptable practice.
Some overburden and waste rock are used as byproducts
(primarily construction materials), but the amount is miniscule
(less than 1 percent).
Stockpiling. The 1.5 billion tons (1.4 Pg) of overburden
and waste rock stockpiled annually (Table 7) may create adverse
environmental impact in terms of surface and groundwater
pollution, air pollution from fugitive dust emissions, and
aesthetics. This amount includes nearly 100 percent of the
wastes from open pit copper mining operations [689 million tons
(625 Gg)] and about 93 percent of the wastes from uranium
5 6
mining. ' The overburden can be placed immediately adjacent to
the excavated area (which was the practice on the downhill slopes
of eastern coal contour strip mines such as those in West
Virginia, Kentucky, and eastern Ohio ); hauled by truck or
conveyor to fill in the head of a hollow or saddle in the ridge
line of mountainous terrain (a common practice in the lead, zinc,
silver, and uranium surface mining areas of Washington and
o
Idaho ); or deposited on the outside slopes of open pit copper
mines in the Southwest.
Regardless of where they are located and the surrounding
conditions, nearly all wastes require some kind of stabilization.
119
-------
Wastes disposed of in areas where the relatively gentle slopes
will naturally support native vegetation are the rare exceptions.
Backfilling. Disposal of overburden from surface mines by
backfilling occurs primarily when mining methods involve
placement of overburden into an adjacent previously excavated
area. These mining methods include the following:
Modified Block-Cut or Pit Storage Mining (Figure 16). This
method was developed as an alternative to standard contour strip
mining methods for recovering coal; it facilitates contour
regrading, minimizes overburden handling, and contains overburden
within the mined areas. Only the material from the first box-cut
is deposited in adjacent low areas (such as a saddle in the ridge
line) or at the head of a hollow. Thus far, experience with this
method has been limited to terrain slopes of less than 20 degrees
and average highwall heights of 60 ft (18 m); however, this
technique has proven to be feasible in steeper terrain. Because
the amount of open highwall needed for auger mining is limited,
g
it could hinder auger recovery of highwall reserves.
This mining method appears to be no more expensive than any
other method where contour regrading is required, and it could
prove to be less expensive.
Box-Cut Mining Employing Two Cuts. The box-cut method using
two cuts (Figure 17) is a refinement of the contour mining
procedure. Initially, vegetation is removed and suitable topsoil
overburden is stockpiled. The remaining overburden is removed to
a predetermined elevation. The box-cut operation then begins
120
-------
CUT 1
HIGHWALL—
HILL
DIAGRAM A
VALLEY
CZD SPOIL BANK
CZJ SPOIL BACKFILL
^" OUTCROP BARRIER
CUT 2
CUT 1^-
HIGHWALL—•
HILL
DIAGRAM B
VALLEY
CUT 2
CUT 1
HIGHWALL
CUT 3
HILL
DIAGRAM C
VALLEY
HILL
DIAGRAM D
CUT 3
VALLEY
VALLEY
HILL
DIAGRAM F
CUT 5
VALLEY
Figure 16. This diagram shows a modified block cut.
Source: Skelly and Loy. Processes, procedures, and methods
to control pollution from mining activities.
Environmental Protection Agency Document
430/9-73-011, prepared under Contract No.
68-01-1830, U.S. Environmental Protection
Agency, Office of Water Program Operations,
Washington, 1973.
121
-------
•DIVERSION DITCH
HIGHWALL
MINERAL SEAM
ORIGINAL GROUND SURFACE
FIRST STEP
TOE OF
FILL
-DIVERSION DITCH
•HIGHWALL
/;•'••'A SPOIL FROM
/. - " • ; 7'.~S FIRST PIT
/ .". i> ' •-- •
Xj. ' • , 1° • ." a • -" « ''"' '
MINERAL SEAM
ORIGINAL GROUND SURFACE
SECOND STEP
TOE OF
FILL-,
Figure 17. This figure shows box-cut mining using
two cuts.
(continued)
122
-------
-DIVERSION DITCH
•HIGHWALL
SPOIL FROM
EXCESS SPOIL FROM
AND SECOND PITS
BARRIER-
•1 ^U^HSStlS.,P l T
MINERAL SEAM
ORIGINAL
GROUND SURFACE
THIRD STEP
DIVERSION DITCH
REVERSE-TERRACE SLOPE
HIGHWALL
\ FINISHED GRADE
\ SURFACE
ORIGINAL
GROUND SURFACE
TOE OF
FOURTH STEP
Source:
Figure 17. (continued)
Skelly and Loy. Processes, procedures, and
methods to control pollution.
123
-------
nearest the exposed highwall, and this overburden is cast on the
bench over the low wall barrier. The mineral is extracted from
the first cut opening. A second cut is then made toward the low
wall barrier, and the overburden is backfilled into the first cut
trench. After completion of mining, the remaining second cut
9
overburden is regraded.
Backfilling often results in a reverse terrace because it is
usually done with poorer material. This can be overcome somewhat
by segregating the overburden, putting topsoil back as a final
cover, and properly vegetating the area; however, it is difficult
to segregate overburden when the box-cut mining method is used.
Area mining. Area mining (Figure 7) generally is used in
relatively flat terrain where mineral seams are roughly parallel
to land surface. Although area mining has been used almost
exclusively for coal, it can be used for any mineral found in
9
seams whose geometry is similar to coal.
An area mine is usually started with a box-cut, or trench,
which extends to the limits of the property or vein deposit and
has an adjacent parallel bank of overburden. Overburden from
each successive parallel cut is placed in the preceding trench.
The last cut is bounded by overburden material on one side and an
undisturbed highwall on the other.
Area mining is likely to be used extensively in the
development of western coal fields, and revegetation is extremely
9
difficult in these arid and semiarid regions.
124
-------
In some underground mining methods, waste rock is backfilled
into previously mined sections as it is excavated, thus
eliminating the surface stockpiling of this material. These
mining methods include cut-and-fill stoping, square-set stoping
(Figure 18), and to a very limited extent, block caving.
Although these methods were developed primarily to provide
structural stability to the mined areas, they nonetheless result
in an essentially environmentally safe means of waste disposal.
Utilization. Utilization of overburden and waste rock as
byproducts has been and will probably continue to be limited
almost exclusively to its use as construction material. Selected
portions of these wastes with proper chemical characteristics can
be used on site to construct roads and tailings pond embankments.
Certain wastes that are not easily eroded have also been used as
cover for less stable wastes that are more subject to weathering.
Overburden and waste rock also may be marketed as construction
materials for offsite application. Sometimes mining companies
and offsite users have an arrangement whereby the user loads and
hauls the material off the mine site without any exchange of
money. Offsite uses include aggregate for concrete and asphalt
mixes, fill material, and subbase for highway construction.
Certain mining wastes may provide a better material for use in
specific applications than conventional materials, and in some
instances, may result in cost savings.
The U.S. Bureau of Mines has extensively investigated wastes
from such mining operations as slate and lime rock quarries and
125
-------
RAISE SET
GIRT
FLOOR
CAP
POST
FILL
VERTICAL SECTION
BLOCKING
FLOOR
WASTE ROCK
BACKFILLED
DOWNWARD
AS EXCAVATION
PROCEEDS
UPWARD
POST
LEAD SET
CAP
GIRT
CORNER SET
PLAN OF A MINING FLOOR
Figure 18. This figure illustrates square-set stoping,
a type of underground mining.
Source: Colorado Mining Association. Anatomy of a mine--
frpra prospect to production. Denver, 1975.
126
-------
phosphate rock mines. In some cases these wastes were found to
have potential uses. For instance, waste slate for asphalt road
surface mixtures and waste slate dust as a filler for briquettes
normally containing either limestone or portland cement were
12
found to be equivalent to the conventional materials used.
Despite the many potential uses that have been researched
and developed for overburden and waste rock, the vast quantities
generated annually, coupled with the severe economic limitations
associated with the long shipping distances from the remotely
located mines, preclude utilization as a practical means of
disposing of mine solid wastes in most cases.
Disposal of Tailings
Nearly all (99+ percent) of the tailings generated annually
by beneficiating processes are disposed of in terrestrial
impoundments or tailings ponds. The rest are backfilled into
underground mines, discharged to lakes or saltwater bodies, or
4
utilized as construction materials (Table 10) .
Tailings Ponds. Tailings are discharged into a pond in the
2 12
form of a slurry, typically 50 to 85 percent water by weight. '
These ponds are usually situated in small valleys or against
hillsides, and a single dike is constructed to contain the
tailings. In flat areas, dikes must be built on all sides.
The tailings characteristic that varies the most is
grain-size distribution (described in detail by selected minerals
in Section 3). This characteristic is significant because it
determines the method required for safe containment. If they
127
-------
contain a sufficient percentage of coarse materials (usually
called "sands"), the tailings can be segregated during disposal,
and the coarse sands can be used as a confining embankment for
finer materials, which will not drain and have low shear strength.
These coarse materials can be separated by gravity (in a method
called "upstream construction") or by cycloning (in a method
called "downstream construction") (Figure 19).
If the tailings do not contain sufficient sands to form a
safe, well-drained embankment of acceptable density, permeability,
and shear strength, materials (either natural rock or mine waste
rock) must be imported to construct the embankment (Figure 19).
The foundation requirements for tailings embankments are
identical to those for any other kind of dam or embankment. The
foundation material must be strong enough to support the weight
of the structure without shear failure or movement under the
load. The latter factor is particularly significant when
disposal is on steep slopes or draws, because the weight of the
embankment plus the effect of the water in the slurry may produce
landslide conditions, especially if the area is subject to
seismic events.
If hazardous wastes are present in the tailings, foundation
materials should also be impermeable enough to prevent leakage
from the tailings pond to the groundwater flow system beneath the
pond and embankment and to springs alongside the embankment. If
such impermeable materials are not available, the pond should be
lined, the foundation material treated chemically, or the tailings
128
-------
DISCHARGE ALONG
EMBANKMENT
f-FREE WATER
=^r~- SLIMES
(A) UPSTREAM CONSTRUCTION
DISCHARGE
ALONG EMBANKMENT
(B) DOWNSTREAM CONSTRUCTION
1'CYCLONED"
SANDS
DISCHARGE
OPPOSITE
EMBANKMENT
SANDS
FREE WATER
CONSTRUCTED
EMBANKMENT
(C) CONSTRUCTION WITH IMPORTED MATERIALS
Figure 19. Shown above are the three basic
methods of tailings pond construction.
129
-------
carefully segregated and the water level maintained over the
2
slime zone. Cutoff walls and blankets and cores may also be
required to prevent leakage through and beneath the embankment
when appropriate materials are not available (Figure 20).
Earth liners are sometimes used for tailings ponds,
especially where a supply of clay or claylike material is
available near the site. Tailings slimes may be used if their
2
permeablility is low. Commercial bentonite, whose permeability
is increased by low pH water, can be added to fine-textured soils
to reduce their permeability to acceptable levels. Artificial
liner materials include soil cements, treated bentonite petroleum
derivatives, plastics, elastomers, and rubber. These liners are
more expensive1 than earth materials, and earthwork is still
required to prepare the ground surface. In some cases liner
materials must be resistant to possible corrosive effects of the
pond liquid and to sunlight if they are not covered immediately
after placement. The uranium milling industry is currently the
largest user of tailings pond liners. Such usage has not become
common in other mining industries. Tailings pond seepage and
consequent groundwater pollution can occur if (1) the site has
not been selected properly, (2) tailings are too coarse or are
improperly distributed in the pond, (3) poor quality water is
introduced into the tailings pond from nonbeneficiation sources
(such as acid mine drainage), (4) if pyrite concentration in the
14
tailings is sufficient to oxidize and produce acid seepage.
130
-------
IMPERMEABLE
MATERIAL
o.
o^^
BLANKET AND CORE •
IMPERMEABLE
MATERIAL
TAILINGS viv;-.;;.;:-/':-;.;.;.:-:^
<^ r> °
SAND AND GRAVELD*
FOUNDATION CUTOFF WALL
CUTOFF WALL AND
OPEN TRENCH
TO MILL OR
TREATMENT
PLANT
IMPERMEABLE
MATERIAL
Figure 20. Some methods used to minimize seepage
outflow are shown above.
Source: Williams, R.E. Waste production and disposal
in mining, milling, and metallurgical
industries. San Francisco, Miller Freeman
Publication, Inc., 1975. 489 p.
131
-------
The slope of the embankment must be determined by the
climatic conditions (as revealed by the site selection
investigation) and by the physical properties of the material
used in the embankment (angle of internal friction, density,
permeability, shear strength, angle of repose). Model studies
are helpful in determining stable slope angles once these
variables have been identified. The safety factor for a tailings
dam is obtainable through standard engineering procedures once
the slope, physical properties of the embankment material
(especially density), and the configuration of the phreatic (free
2
water) line are known.
Tailings ponds normally are drained by decant towers,
siphons, or pumps. Regardless of the method used to remove the
water from tailings ponds, however, great care must be taken to
design sufficient freeboard to handle peak runoff/ particularly
if tailings embankments are in draws. Alternatively, diversion
structures may be constructed to handle the runoff predicted by
the hydrologic analysis conducted during the site selection
process. Diversion structures should also be used if the poor
quality of the water within the pond precludes its being
2
discharged to a stream.
Embankments should include monitoring devices to ascertain
that the structure is performing adequately. Instrumentation
should include piezometers to monitor the configuration of the
phreatic line, subembankment pressures, and the quantity and
quality of the leachate. The main groundwater zone should be
132
-------
monitored to check the impact of the tailings pond leachate. If
contamination of the groundwater is detected, leachate can be
recovered by pumping the groundwater out unless the saturated
materials are very low or very high in permeability. Slope
indicators should be installed to be sure creep does not occur or
2
to detect it before failure if it should occur.
Backfilling Underground Mines. The practice of backfilling
underground mines with beneficiation tailings was reportedly
first employed in 1864 at an anthracite coal mine in Shenandoah,
14
Pennsylvania, where backfilling was done hydraulically. Almost
all underground metal mines in Idaho have adopted the practice of
2
backfilling abandoned stopes with the coarser fraction of tailings.
On a national scale, however, backfilling is not considered a
good mining technique; neither is it economically feasible,
except in unique situations.
The main environmental advantages of backfilling with coarse
tailings are improved recovery of the underground ore body, some
reduction in volume of tailings that must be impounded (thus
reducing the surface area needed), and lessening of surface
subsidence. The major disadvantages of backfilling are that it
introduces additional water into the mine, it results in
occasional spills, and it necessitates importing material for
tailings embankments when too much of the coarse fraction is
removed from the tailings. The Bureau of Mines investigations of
backfilling in the Coeur d'Alene district of northern Idaho
indicate that it should be possible to dispose of a greater
133
-------
percentage of tailings by backfilling than has been the practice.
Using tailings as fine as No. 200 sieve is believed feasible,
which would mean that as much as 50 percent of the average copper,
lead, or zinc tailings from underground mining could be backfilled.
The primary objection to backfilling with finer tailings is cost
and the risk of poor drainage and reduced strength, which could
introduce the possibility of bulkhead failures. Some investigators
believe, however, that essentially all underground tailings can
be used if electrokinetic backfilling is utilized to assure
2
proper drainage. The primary deterrent, especially since 1974,
is the cost of energy required to dewater the finer tailings
electrpkinetically.
Lake/Marine Disposal. Subaqueous disposal of tailings in
freshwater and saltwater bodies has been practiced occasionally
by a few operations in the United States and Canada and more
2 16
frequently on a world-wide basis. ' Under permit in I960, the
Reserve Mining Company Silver Bay taconite plant discharged
73,700 tons (67 Mg) of tailings per day into Lake Superior
through a trough 58 miles (107 km) long and 3 miles (6 km) wide
at a depth of 900 ft (274 m). This much publicized event is the
best known example of this disposal method in the United States.
Although the idea of marine disposal of tailings (like
domestic refuse and sewage disposal of this type) is initially
objectionable in that it involves pouring untreated wastes
directly into the water, several operating and environmental
advantages may be considered:
134
-------
Operating advantages ' '
0 Once the disposal facility has been constructed,
operating costs would be low, perhaps even zero.
0 The storage area would be more or less limitless in
volume.
0 The system contains few components that are subject to
mechanical failure.
0 This practice offers the greatest physical safety in
that it eliminates possible impoundment failure or
slumping.
Environmental advantages:
0 The nature of seawater (markedly alkaline) and its low
levels of oxygen at depth prevent the generation of
acidity, thus minimizing problems of acid mine drainage
and the release of soluble heavy metals.
0 If the disposal point has been carefully chosen, no
visual impact should occur.
0 The greater volume and turbulence of the sea, compared
with lakes, are likely to promote maximum dilution and
mixing of any soluble toxic constituents.
0 Because the biological composition of seawater is
different from that of freshwater, the impact of
toxicants will be different, perhaps less.
0 Reclamation and revegetation problems are eliminated.
The main operating disadvantages are lack of control over
what happens to the tailings after disposal and little chance of
future reworking them for metal recovery. The principal
environmental disadvantages, apart from those of toxicity
(mentioned above), also relate to inaccessibility after dumping.
In land impoundment, decanted tailings liquid can be chemically
treated to render it innocuous. Marine disposal, on the other
hand, does not entail separation of liquid and solid phases;
therefore incorporation of any chemical purification stages
135
-------
before discharge would probably be much more difficult. The most
important environmental disadvantage is that the tailings smother
all the benthic life in the vicinity of disposal.
There is a significant cost advantage associated with
lake/marine disposal when compared with, for example, the proposed
alternative closed-circuit land disposal system for the Reserve
Mining Company. This system will cover 7.6 square miles (19.7
19,20
2
Mm ) and cost an estimated $252 million, which is the largest
single mining environmental cost recorded in the United States.
Despite cost and operating advantages, the environmental
disadvantages of subaqueous disposal are overriding; consequently,
waste discharge permits for subaqueous disposal in the United
States (under Public Law 92-500) are expected to be difficult, if
2
not impossible, to obtain.
Utilization. Tailings, like overburden and waste rock, are
utilized almost exclusively as construction material, primarily
for highways. The utilization of tailings having acceptable
engineering properties is considered the best disposal method,
both economically and environmentally. On the mine site,
tailings are used to construct haul roads and tailings pond
embankments and as an aggregate for paving mixtures. Off site,
primary construction uses are as fill for highway embankments,
subbase material for concrete and asphalt highways, antiskid
snow-control material for highways, and aggregate for concrete
and asphalt paving mixes. Tailings from nearly all mining
industries have been used for highway construction fill in all
mining states.
136
-------
All industry tailings cannot be used as construction
material. For example, the radioactivity of uranium tailings
(high in concentrated radium 226) and other minerals whose host
rock contains radium (e.g., phosphate) precludes their safe use
as construction materials. The high levels of radon from uranium
tailings, used as fill material for residential home foundations
in the West, illustrates this point.
The near completion of the interstate highway system within
the last decade precludes further use of vast quantities of
tailings for highway construction on a nationwide basis. On a
regional basis, however, a cornerstone of the development plan
for the 13-state Appalachian region is a modern road transportation
network. This plan presents the possibility of combining the
elimination of coal refuse banks with their concurrent utilization
in this highway network. Coal refuse characteristics (especially
the tendency for spontaneous combustion and acid drainage) were
once believed to preclude its extensive use in highway
construction. These problems, however, have been solved (through
U.S. and British research) by proper compaction and soil cover
techniques. In addition, coal refuse has distinct advantages
over conventional highway construction materials in terms of
workability during wet and freezing weather. Research/demonstration
studies are being conducted by the U.S. Environmental Protection
Agency, U.S. Department of Transportation, West Virginia University,
and others to develop these properties further. Utilization of
coal refuse as a highway construction material by the road
21
building agencies in several Appalachian states is being considered.
137
-------
Some other construction material uses for tailings are as
filler for brick manufacturing and fill for reclamation of
swamplands for commercial and recreational purposes. The
economic potential of using raw coal waste material and fly ash
in the manufacture of bricks, blocks, lightweight aggregate, and
other products has become more attractive in the last few years.
In Great Britain large volumes of coal waste and fly ash are used
to manufacture useful products, and such usages are becoming more
frequent in the United States. Raw coal waste and fly ash have
also been tested for use in mine subsidence control in several
22
research studies in recent years.
Another potential utilization of coal refuse, which may have
a promising economic incentive, is the production of alumina.
Annual domestic requirements for aluminum may increase to from 5
to 10 times the present level by the year 2000. It has been
predicted that by 1980 or shortly thereafter the industry may
begin processing low-grade bauxites, clays, shales, and other
22
materials to meet the demand. High-grade aluminum sulfate was
produced from coal refuse as early as 1962. Renewed interest in
this utilization of coal refuse may be very timely because
unstable international conditions make foreign imports
22
unreliable. :
Utilization of numerous coal refuse banks in the Appalachian
region as highway construction material appears promising, but
the nationwide outlook for extensive disposal of the vast
quantities of noncoal tailings by utilization is dim. This is
138
-------
due in part to the economic limitations of transporting this
material from the remotely located mines.
Stabilization/Control/Reclamation
The importance of implementing disposal, stabilization, and
control techniques is underscored by the magnitude of mineral
resource waste production (detailed in Section 3). Land
reclamation has not always been practiced as widely as it is
today. Even now the extent of reclamation varies widely. The
trend toward more stringent legislation, however, is making
mining companies increasingly aware of their obligation to
restore the land and to escalate reclamation activities. The
recently passed Federal Surface Mining Control and Reclamation
Act is adding a new dimension to reclamation of coal mine lands.
This subsection discusses stabilization and control methods that
are being implemented (at both active mines and abandoned mines),
which are designed to prevent air and water pollution and to
2
create as aesthetically acceptable an area as possible.
The high visibility of the unsightly coal-preparation waste
piles, especially in the heavily populated East, and the fact
that approximately 40 percent of the total land disturbed by past
and present mining activities is the result of coal mining
operations have made coal mining companies lead in the area of
reclaiming mined lands concurrently with extraction operations.
Nevertheless, this concept of the extraction-rehabilitation
sequence is catching on rapidly in noncoal mining industries
139
-------
(such as copper, phosphate rock, and iron), even though these
mine wastes are generally less visible and spacious than coal
mine wastes.
In the coal industry, restoration of a mined area to the
desired condition includes landscaping, stabilization by physical
and chemical means (especially during ongoing mining activities),
soil amelioration, and revegetation. In other mining industries,
one or more of these steps may be taken. Company policy and the
various desired goals of reclamation efforts (such as creation of
lakes from abandoned open pit mines or quarries, grazing lands,
park and recreational areas, crop lands, sports areas, campgrounds,
sanitary landfills, and home sites) determine the manner and
sequence in which these procedures are applied.
Landscaping. Landscaping involves the shaping of the
surface of mineral resource wastes and/or adjacent areas to
achieve some predetermined objective. Primarily intended for
environmental control of water/wind erosion and leaching,
landscaping can also be used for such purposes as reshaping an
area around a lake for recreational use. The key to success in
the landscaping rehabilitation phase of any reclamation program
is the formulation and implementation of an extraction-rehabilitatic
plan, as opposed to the practice of simply extracting ore from
the ground and recovering the product from it. Such a plan would
2
fulfill the following objectives :
140
-------
(1) Creation of final topography that blends with the
adjoining undisturbed landscape.
(2) Creation of a surface drainage pattern that does not
promote ponding unless the pond is planned and properly
designed.
(3) Creation of a soil condition capable of supporting
plant life equal to that of the regional landscape.
(4) Provision for ground cover for erosion control as soon
as soil conditions allow.
(5) Provision for use at some economic value if at all
possible.
(6) Organization of the various steps in the operating
sequence for optimum operating efficiency.
Although only (1) and (2) deal directly with landscaping,
all are essential to successful reclamation. In some reclamation
projects it is desirable not to duplicate the landscape of the
surrounding environment. This applies to recreation projects in
areas where the water table is sufficiently near the surface to
facilitate the creation of artificial lakes and to agricultural
2
areas where forested hills are needed to relieve monotony.
It is important to plan preliminary overburden removal to
include segregation of the top organic soil layer for subsequent
regrading and revegetation. Overburden segregation is also
important for water pollution control, in that potentially
pollutant material such as pyritic material (which forms acid
drainage) can be isolated from contact with surface and leaching
waters. When segregation is practiced, the layer of potentially
pollutant material is sandwiched between layers of low-permeability,
clean material in the final regrading, then covered by a layer of
141
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9
topsoil. This technique is particularly applicable to the cut
2
and fill method of flat area stripping.
In the contour stripping technique commonly practiced on the
steeper slopes of Appalachia, overburden segregation is difficult
to implement. Stripped waste tends to move downslope, making
retrieval extremely expensive because it must be accomplished
against gravity. The downslope movement is also devastating to
2
vegetation and to the quality of down-gradient streams.
Overburden segregation is seldom applied at abandoned
surface mining areas where the waste material is a mixture of
various materials. Although postmining landscaping and
revegetation have been demonstrated as feasible reclamation
procedures in such areas, they are expensive.
Physical and Chemical Waste Stabilization. Physical or
chemical stabilization of mine wastes is sometimes substituted
for revegetation to minimize air pollution and water pollution,
especially during ongoing mining operations. Chemical
stabilization is also frequently used simultaneously with
revegetation so that plants will not be destroyed by abrasion or
2
erosion before they mature and form a protective cover.
Physical Methods. Physical control methods involve placing
a separate cover or barrier over the waste pile to reduce the
wind speed reaching the fine particulates of the pile, consolidate
the surface by binding particles, impede moisture loss from the
surface, and generally protect and isolate the underlying waste
from the environment. Physical methods effect control by putting
142
-------
a lid over the waste or isolating it within an enclosure. The
freedom and ease of interaction of the surface with the
9
environment are thus reduced. Stabilization is usually
accomplished with a rock cover composed of erosion-resistant
waste rock from the mining operation (if such exists). Gunite,
asphalt, and concrete are also effective, but they are expensive.
Smelter slag has been used, as well as bark covers and imported
topsoil. Because all physical stabilization methods (except the
use of imported topsoil) have the disadvantage of creating a
waste pile that seldom blends with its natural surroundings,
2
they are not widely utilized.
Fugitive emissions from mining haul roads used to transport
wastes are most effectively controlled by paving these roads with
concrete or asphalt. This approach is so expensive, however,
that it has not been given widespread serious consideration.
Exceptions are the paving of main haul roads that are intended
for long-term use. Available control methods for controlling
fugitive dust emissions that are attendant to solid waste
23
disposal are shown below :
Control efficiency
Source Control method (percent)
Unpaved roads Paving 85
Chemical stabilization 50
Watering 50
Speed reduction Variable
Oiling and double-chip
surface 85
Road shoulders Stabilization 80
Water spraying (the most frequently employed method of
suppressing dust from mining haul roads) is a straightforward
143
-------
method of reducing wind erosion by maintaining high surface
moisture; however, it is not widely practiced to control
windblown fugitive dust from overburden piles because of the vast
areas involved and the fact that fugitive dust from overburden
piles is usually not a significant problem. Also, it provides
only temporary control. Moreover, climatic variables, such as
lack of readily available water and/or freezing plumbing,
9
adversely affect operating costs and effectiveness.
Improved fugitive dust control of overburden/waste rock
piles, dry tailings piles, and haul roads can be achieved by
adding a surface-active agent to the spray water to reduce its
9
surface tension and increase its dust wetting properties. With
greater wetting properties, less water solution is required to
agglomerate and stabilize the surface layer of the pile. Water
quantity equalling 1/2 to 1 percent of the pile weight is
necessary if a wetting agent is added, as opposed to 5 to 8
9
percent by weight when using untreated water. .
Chemical Stabilization. Chemical stabilization involves
mixing a reagent with overburden and tailings to form an
air- and water-resistant crust or layer that effectively stops
dusts from blowing and inhibits water erosion. Although
stabilization is not as durable as soil covering or vegetation,
it can be used on sites unsuited for vegetative growth because of
harsh climatic conditions or the presence of vegetable poisons in
the waste piles or tailings, or in areas where soil-covering
material is not available. Chemical stabilization can also be
144
-------
applied to control erosion of active tailings ponds. Application
of chemicals on the dry, inactive portions of these ponds can
restrict air pollution while other portions are still active
(wet). Satisfactory long-term chemical stabilization is
difficult to achieve, however, because the surfaces of tailings
24
piles are seldom homogeneous. Freezing and thawing also tend
to break the crust.
Chemically stabilized waste surfaces are seldom meant to be
permanent, and they offer the same aesthetic disadvantage as
physically stabilized wastes. The most desirable aspect of
chemical stabilizers is that they may prevent the destruction of
vegetative covers during early growth stages.
The U.S. Bureau of Mines in Salt Lake City has tested over
70 chemical compositions and has named the 13 best according to
their effectiveness (Table 11).
Vegetative Stabilization (Revegetation). Revegetation
(installing a vegetative cover) is used to accomplish the
following:
0 Help stabilize erodible slopes and thus minimize
stream pollution.
0 Control dust.
0 Improve aesthetics of an area.
0 Increase evapotranspiration so that a minimum percentage
of precipitation enters the runoff cycle.
0 Facilitate the crop producing potential of some areas
for purposes of profit.
0 More rapidly stabilize the oxidation of pyrite and the
concomitant production of acid mine drainage by preventing
continuous exposure of new pyrite by erosion.
0 Restore wildlife habitats.
145
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TABLE 11
CHEMICAL BINDING SURFACE TREATMENTS IN DESCENDING ORDER OF RANK BY
THE USBM, SALT LAKE CITY*
Name
Coherex
Description
Resinous adhesive
Dose
240 gal/acre
Cost
$65/acre
$650/acre
Remark st
Good wind resistance
Good water-jet
resistance
Supplier
witco Chemical Co.
Lignosulfonates
SP-400 Soil Card
DCA-70
Cement and milk of lime
Paracol TC 1842
Pamak WTP
Petroset SB-1
Potassium silicate
with an SiO^-to-I^O
ratio of 2.5
PB-4601
Reosol cationic
neoprene
Dresinol, TC 1843
Sodium silicates with
ratios of 2.4 to 2.9
SiO2 to 1 NajO
Calcium
Sodium Lignosul-
Ammonium fonates
2400 Ib/acre
Elastomeric polymers 55 gal/acre
90 gal/acre
50 gal/acre
Resin emulsion
Wax, tar, and pitch
product
Elastomeric polymers
Polymeric stabilizing
plant
Elastomeric polymer
emulsion
Ammonium casein
S130-$170/acre
S130/acre
Exceptionally effective
on sand tailings;
satisfactory on both
acidic and alkaline
tailings
Alco Chemical Co.
Union Carbide
$190/acre
S250/acre
$250/acre
5250/acre
$450-$920/acre
S500/acre
$500/acre
$500/acre
$200/acre
Phillips Petroleum
Calcium chloride can be
used in place of some
of the sodium silicate
* Donovan, R.P., R.M. Felder, and H.H. Rogers. Vegetative stabilization of mineral waste heaps. EPA-600/2-76-087,
Research Triangle Institute for Industrial Environmental Research Laboratory, Office of Energy, Minerals, and Industry,
Environmental Protection Agency, Research Triangle Park, North Carolina, April 1976.
t Test conditions of:
a) Water jet at various pressures to simulate water erosion.
b) Hind tunnel at 100 mph and various orientations to simulate wind erosion.
-------
Selection of a vegetative cover is based primarily on the
condition of the waste to be covered and on local topographic and
climatic conditions. The most significant waste characteristic
is soil pH; however, organics, nutrients, salt content, and
grain-size distribution also play major roles. Although the most
significant climatic factor is the nature and distribution of
precipitation, the mean, maximum, and minimum temperatures
(annual and daily) are also significant. Heavy metals will
affect some plants if their concentrations are sufficiently high.
Some plants will grow on beneficiation wastes, in spite of
significant increases in their heavy metal uptake, whereas others
will die.
Nutrients required for plant growth include nitrogen,
calcium, magnesium, sulfur, potassium, phosphorus, and trace
quantities of various metals. Tailings are particularly
difficult to revegetate because they are usually deficient in
plant nutrients, sometimes contain excessive salts and heavy
metal phytotoxicants, consist of unconsolidated sands or shales
that destroy young plants by sandblasting and/or burial during
2
surface water erosion, and lack normal microbial populations.
Tailings are always deficient in nitrogen, and it must be added;
with the proper choice of nitrogen-fixing vegetative species and
sufficient organic matter, however, the nitrogen balance can be
g
restored without continued supplement.
Revegetation can be accomplished by transplanting or (most
commonly) by seeding. Seeding techniques are drilling,
147
-------
broadcasting, and hydroseeding. Hydroseeding has been more
widely adopted for waste heaps when slopes are appreciable and
2
additives are necessary to enhance germination. Fertilizers
and mulches can also be utilized with the drilling and
broadcasting techniques.
Given enough time and resources, any mineral waste heap in
the United States could be covered with vegetation; the problem
is to establish a cover at a cost compatible with the value of
the land before and after the reclamation. In spite of the
lengthy and intensive investigations of vegetative stabilization
of mineral waste heaps that have been and are being carried out
by U.S. Government, university, and industrial researchers, the
problem is still too complex to permit the formulation of
guaranteed revegetation procedures. In practice each new
candidate site for vegetative cover must be treated as unique;
trial-and-error experimentation of test plots must precede any
large scale revegetation effort, using previous experience as a
general guideline.
Cost comparisons have been made of the various methods
employed for stabilizing tailings (Table 12). These costs are
based on the assumption that extensive chemical treatment is not
needed.
Control/Treatment of Tailings Pond Water. The major
problems associated with water pollution from overburden and
waste rock stockpiles and tailings are acid drainage through
pyritic waste material that is unprotected from percolating
148
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TABLE 12
COST COMPARISON OF STABILIZATION METHODS*
Type of
stabilization Effectiveness
PHYSICAL
Water sprinkling
Slag (9-in. depth)
By pumping
By trucking
Straw harrowing
Bark covering
Country gravel and
soil
4-in. depth
12-in. depth
CHEMICAL
Elastomeric polymer
Lignosulfonate
Fair
Good
Good
Fair
Good
Excellent
Excellent
Good
Good
Maintenance
Continual
Moderate
Moderate
Moderate
Moderate
Minimal
Minimal
Moderate
Moderate
Approximate
cost per acre (S)
350-
950-1
40-
900-1
250-
700-1
300-
250-
450
,050
75
,000
600
,700
750
600
VEGETATIVE
Revegetation
4-in. soil cover
and vegetationt
12-in. soil cover
Excellent
Minimal
300- 650
and vegetation
Hydroseeding
Matting!
Chemical-vegetative
Excellent
Excellent
Excellent
Excellent
Minimal
Minimal
Minimal
Minimal
750-1
600-
600-
100-
,750
750
750
250
* ,Dean, K.C., R. Havens, and M.W. Glanly. Methods and costs
for stabilizing fine-sized mineral wastes. Bureau of Mines Report
of Investigations - RI 7896, 1974.
i Generally used on pond area rather than on dikes. Also,
not as effective as 12-in. soil cover when tailings are
excessively acidic or saline.
§ Based on placing 3-ft-wide matting at 3-ft intervals over
the seeded area.
Notes: Based on average tailings, costs could be
revised upward for acidic tailings requiring limestone or
other neutralizing additives.
Metric conversion table in front matter.
149
-------
surface and tailing waters, surface runoff that contacts these
wastes, and direct discharge of polluted tailings waters. Acid
draingage from pyritic wastes and surface runoff of polluted
waters can be prevented through previously discussed
stabilization/control methods that isolate and/or protect these
wastes from water contact.
Substantial volumes of effluent contaminated with acidity,
toxic heavy metals, and dissolved particles in tailings water can
cause major damage to the receiving natural waters. To achieve
effective purification at an acceptable cost, it is important to
•control water flows as well as to provide chemical treatment.
There are several routes of water ingress and egress at a tailings
pond (Figure 21). With the exception of incoming precipitation,
the routes and volumes of each class of water can be controlled.
It is always more feasible to prevent contamination of natural
waters than to attempt purification afterwards. Thus, if the
volume of surface runoff is significant, interception ditches can
be installed. The quantities of water input from beneficiation
can be lessened with thickeners. This practice simplifies water
reclamation while simultaneously lessening the storage volume
required at the impoundment.
Reclaiming of water from tailings impoundments is important
for water pollution control and water conservation. The ideal
situation is to reclaim the total impoundment effluent, with only
small volumes of fresh makeup water being added to compensate for
evaporation losses, seepage losses, and water entrapped in the
150
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DECANT/RECLAIM
EVAPORATION "\ PRECIPITATION
OVERFLOW
PRECIPITATION
MILL
SLURRY
AM WALL
RESURGENCE
BELUw~DA
PERCOLATION TO SUBSOIL
AND GROUNDWATER
Figure 21. There are various routes of water
gain and loss at a tailings impoundment.
Source: Down, C.G., and J. Stocks. Environmental
problems of tailings disposal. Mining
Magazine, 25-33, July 1977.
151
-------
tailings. Many mining operations do achieve this, particularly
in the Missouri lead belt and the Southwest. Some uranium
facilities recycle up to 75 percent of their water, and many
copper operations practice total recycle. The entire phosphate
27
industry recycles about 85 percent of its water.
Reagents used in beneficiation are another potential source
of water pollution and have been the subject of much study. Some
reagents are highly toxic to aquatic life; others are nontoxic.
Some are persistent; some degrade rapidly. Thus they may or may
not appear in the tailings pond effluent or in leachate from the
tailings. The following guidelines have been suggested for the
selection of reagents.
(1) When there is a choice, the least toxic compounds or
toxic compounds that degrade rapidly to innocuous
chemicals should be selected.
(2) Persistent chemicals should be avoided whenever possible.
(3) Reagents that are also nutrients should not be used.
(4) Reagents containing water-soluble metal salts should
not be used.16
The following are well-established methods of treating
tailings water before it is discharged to surface streams or
recycled:
(1) Sedimentation. (This primary function of the tailings
pond may be supplemented by other settling ponds,
clarifiers, or thickeners.)
(2) Flocculation. (This involves the use of reagents to
promote settling by altering the particle charges that
prevent agglomeration.)
(3) Mechanical methods such as centrifugation, hydrocyclones,
and filtration. (These, are only used in isolated
cases.)
152
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(4) Neutralization (or pH control) by lime or some other
alkali. (This most common technique precipitates out
heavy metals, promotes flocculation, and lessens
acidity.) Limestone is seldom used in modern practice
(5) Precipitation. (This method, primarily applied for
radium removal, uses sulfides and other reagents to
remove metals.)16
153
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REFERENCES FOR SECTION 4
1. Compiled from Bureau of Mines Statistics for 1975.
2. Williams, R.E. Waste production and disposal in mining,
milling, and metallurgical industries. San Francisco,
Miller Freeman Publication, Inc., 1975. 489 p.
3. Wahler, W.A., and Associates. Analysis of coal refuse dam
failure. . Contract Completion Report No. S0122084, U.S.
Bureau of Mines, Department of the Interior, Washington,
1973.
4. Personal communication. R.E. Williams, professor of
hydrogeology, University of Idaho, to J. Greber, PEDCo
Environmental, Inc., May 30, 1978.
5. Personal communication. E.J. Johnson, Arizona Mining
Association, to R. Amick, PEDCo Environmental, Inc.,
May, 1978.
6. Midwest Research Institute. A study of waste generation,
treatment, and disposal in the metals mining industry,
for Environmental Protection Agency, Solid Waste
Management Division, Washington, PB-261052, October 1976.
7. Personal communications during several visits to selected
eastern coal mining areas. Consolidated Coal Company
operations in Cadiz, Ohio (April 1975), southwestern
Pennsylvania, and northern West Virginia (March 1978),
Ohio Power Company, Muskingum, Ohio (April 1975).
8. Personal communications with mine operating personnel during
several visits in northwestern Idaho and northeastern
Washington. Star Morning Mine (lead, zinc, and silver)
Hecla Mining Company; Midnight Mine (uranium) Dawn Mining
Company; Sherwood Mine (uranium) Western Nuclear, Inc.
December 1978.
9. Skelly and Loy. Proccesses, procedures, and methods to
control pollution from mining activities. Environmental
Protection Agency Document 430/9-73-011, prepared under
Contract No. 68-01-1830, U.S. Environmental Protection
Agency, Office of Water Program Operations, Washington,
1973.
10. Personal communication. J. Bowen, Erie Mining Company, to
R. Amick during PEDCo visit to Hoyt Lakes, Minnesota,
iron ore mining operations, January 30, 1978.
154
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11. Collins, R.J., and R.H. Miller. Availability of mining
wastes and their potential use as highway material,
v. 1. Classification and technical environmental analysis,
prepared for Federal Highway Administrator Offices of
Research and Development. Report No. FHWA-RD-76 106 by
Valley Forge Laboratories, May 1976.
12. Spendlove, J.J. Bureau of Mines research on resource recovery,
reclamation, utilization, disposal, and stabilization.
Information Circular 8750, 1977.
13. Mead, W.E., and G.W. Condrat. Groundwater Protection and
Tailings Disposal. Presented at National Convention of
American Society of Civil Engineers, Denver, November 3-7,
1975.
14. Stewart, R.M. Hydraulic backfilling. Mining Engineering,
v. 10, No. 4, 476-480, 1958.
15. Kealy, C.D., and R.E. Williams. Flow through a tailings
pond embankment. Water Resources, 7(1), 143-154,
July 1971.
16. Down, C.G., and J. Stocks. Environmental problems of
tailings disposal. Mining Magazine, 25-33, July 1977.
17. Environmental design considerations for Ontario mining
operations. Ministry of the Environment, Ontario, 1976.
18. Tailings disposal, recommendations for site solution.
Ministry of the Environment, Pollution Control Branch,
1976. Ontario, 244 p.
19. Engineering and Mining Journal, 173(2), 9(1972).
20. Engineering and Mining Journal, 176(8), 151(1975).
21. Demonstration of the utilization of waste products as highway
construction and maintenance materials. Project Prospectus
No. 29, Region 15, Federal Highway Administration, U.S.
Department of Transportation, 1971.
22. Michael Baker, Jr., Inc. Investigation of mining-related
pollution reduction activities and economic incentives in
the Monongahela River Basin. For the Appalachian Research
Commission, Washington, April 1975.
23. PEDCo Environmental, Inc. Technical guidance for control
of industrial process fugitive particulate emissions.
Environmental Protection Agency Pub. No. 450/3-77-010,
Environmental Protection Agency, Office of Air and Waste
Management, Research Triangle Park, North Carolina,
March 1977.
155
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24. Dean, K.C., R. Havens, and M.W. Glanly. Methods and costs
for stabilizing fine-sized mineral wastes. Bureau of
Mines Report of Investigations - RI 7896, 1974.
25. Donovan, R.P., R.M. Felder, and H.H. Rogers. Vegetative
stabilization of mineral waste heaps. EPA-600/2-76-087,
Research Triangle Institute for Industrial Environmental
Research Laboratory, Office of Energy, Minerals, and
Industry, Environmental Protection Agency, Research
Triangle Park, North Carolina, April 1976.
26. Dean, K.C., and R. Havens. Comparative costs and methods
for stabilization of tailings. In Proceedings; Tailings
Disposal Today, International Symposiums, Tucson, 1973.
27. Personal communication. J.R. Wallpole, Senior Counsel of
the American Mining Congress, Washington, D.C. to D. O'bryan,
Office of Research and Development, Environmental Protection
Agency, July 20, 1978.
156
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SECTION 5
ENVIRONMENTAL AND HEALTH ASSESSMENT
This section is concerned both with the direct and resultant
(or indirect) effects of solid waste from mining and beneficiation
activities on human health and the environment. Emphasis is on
waste classified as hazardous. According to criteria set forth
by the Resource Conservation and Recovery Act of 1976 (P.L. 94-580),
Section 3001, a solid waste is considered hazardous if it is
flammable, corrosive, infectious, reactive, radioactive, or
toxic. Although all solid wastes associated with the mining
industry do not meet these criteria, certain of those not
classified as hazardous may have a significant detrimental impact
on land use, aesthetics, flora and fauna, and other aspects of
the environment. In addition, there are varying degrees of
toxicity. The definition and interpretation of toxicity
ultimately must play a significant role in the designation of
hazardous wastes.
Over and above its obvious effects on aesthetics and land
use, mineral resource solid wastes can cause considerable
secondary pollution under certain circumstances. In many
instances, such secondary pollution is effectively controlled by
practices in common use today, but problems still exist at
inactive or improperly controlled sites. Some of the problems
157
-------
result from containment difficulties. Tailings, waste rock, and
overburden that are properly impounded will impact only the
surfaces on which they are contained. Because complete
containment of the volume of waste involved is not feasible, the
routes of environmental distribution and the resultant effects
must be known before the problem of secondary pollution can be
dealt with.
Solid wastes from mining and beneficiation can be distributed
throughout the environment in ground and surface waters, the
atmosphere, and overland by gravity and eolian processes. The
impact of this waste distribution on human health depends largely
on the distance between large mining operations and highly
populated areas. Isolation of mining and beneficiation
facilities might be considered one of the most effective
environmental controls from the standpoint of human health. This
section summarizes currently known environmental impacts of
mineral resource solid wastes. Emphasis is on the routes and
effects of environmental distribution that ultimately determine
the effects on human populations.
Atmospheric Pollution
Solid waste from mining and beneficiation processes can
produce atmospheric emissions. Some components of these
emissions are hazardous. With a few exceptions (such as the
radon gas emanating from the radium in concentrated uranium
tailings), available data indicate that mineral resource solid
wastes, as a whole, do not appear to threaten human health.
158
-------
This conclusion is based partly on the fact that such wastes are
usually isolated from population centers.
The extent of the fugitive dust emission problem created by
mineral resource solid wastes depends on geographic location and
the kind and size of the operation (Tables 13 and 14).' In
general, fugitive dust presents the greatest problem in arid
regions such as the Great Plains or Rocky Mountains.
At active sites, solid waste handling equipment (e.g.,
bulldozers and dump trucks) creates most fugitive dust emissions
while loading, unloading, and transporting the material over
roads. The gasoline and diesel engines on this equipment also
contribute atmospheric pollution such as carbon monoxide, lead,
4
and hydrocarbons. It should be noted, however, that RCRA may
regulate gaseous pollutants emitted from mineral resource wastes,
but not exhaust fumes.
Other sources of fugitive dust are waste banks, overburden
storage piles, and dried tailings ponds or tailings piles. Dust
from waste banks is generally assumed to be of the same
composition as the ore or overburden. Some quarry operations,
particularly those for sand and gravel, process materials
containing silica. The crushing process at these operations
produces a solid waste of undersized fines that also may contain
silica. Monitoring of the particulate air quality at sand and
gravel operations has revealed silica concentrations in the
samples collected in excess of the Occupational Safety and Health
standard in the samples collected.
159
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TABLE 13
FUGITIVE DUST EMISSIONS FROM SELECTED COAL
SURFACE MINING OPERATIONS*
Operation
Travel on haul roads (Ib/vehicle-mile) t
Watered
Unwatered
Shoveling/trucking of overburden (Ib/ton)
Trucking/dumping of overburden (Ib/ton)
Removal of topsoil (lb/yd3)
Scraping
Dumping
Location of mine
Northwest Southwest Southeast
Colorado Wyoming Montana
6.8 13.6 3.35
17.0
Central
No. Dakota
11.2
0.35
0.03
Northeast
Wyoming
4.3
0.0371
0.0025
* Axetell, K., Jr. Survey of fugitive dust from coal mines. Environmental Protection
Agency, Washington, National Technical Information Service. PB-262 176. 305 p.
+ Only vehicle-miles by haul trucks; travel by other vehicles on haul roads is incorporated
into these values.
§ These values could be considered atypical. See referenced material.
Note: Metric conversion table in front matter.
-------
TABLE 14
SUMMARY OF ESTIMATED EMISSIONS FOR SOME MINING OPERATIONS*
Operation
No of
estimates
Range
Emission factors by industry More data
Coal Copper Rock ?2O5 rock Needed
Overburden removal 5
Shoveling/truck loading 5
Haul roads 4
Truck dumping 3
Haste disposal 1
Reclamation 1
0.0008-0.45 Ib/ton of ore 0.0008
0.048-0.10 Ib/ton of overburden 0.05
Neg-0.10 Ib/ton of ore
0.8-2.2 Ib/VMTt
0.00034-0.04 Ib/ton of ore
Neg-14.4 ton/acre per year
Use wind erosion equation,
ton/acre per year
0.05 0.05 0.05 NA
Depends on speeds and controls x
0.02 0.02 0.04 NA
Depends on climate and soil x
NA = Not applicable.
* PEDCo Environmental Specialists, Inc. Evaluation of fugitive dust emissions from mining,
Task 1 report: identification of fugitive dust sources associated with mining. Environmental
Protection Agency No. 68-02-1321. Cincinnati, 1976. 78 p.
t VMT = vehicle miles traveled.
NOTE: Metric conversion table in front matter.
-------
Accidentally ignited waste banks at both active and inactive
g
coal mines also pollute the air. The burning waste produces
emissions containing all the so-called criteria pollutants
(particulates, SO , NO , CO, and HC). In 1964 more than 200 mine
,X J^
fires and nearly 500 waste bank fires were reported in the United
8
States. Data recorded from 1971 to 1973 indicate that coal
refuse fires were the largest source of hazardous benzo(a)pyrene
(BaP) emissions in the United States, averaging an estimated 310
tons (281 megagrams) per year (about 34.7 percent of total BaP
9
emissions). Because of stricter control practices, waste bank
fires are less common today, and a recent source estimates BaP
emissions from coal refuse fires are now less than 50 tons (45
x 10
megagrams) per year.
At most mineral mines, fugitive dust from overburden storage
piles is not considered significantly hazardous because metal
concentrations are probably low. At uranium and some central
Florida phosphate mines, however, dust from mineral resource
wastes may contain radioactive constituents. The radioactive
materials associated with wastes from phosphate mining are found
in the layer of overburden directly above the ore matrix and/or
in the ore itself. Because the fraction of the phosphate mine
waste that contains radioactive materials is usually placed at
the toe of the larger overburden pile, it is subsequently buried
12
when the site is regraded.
Radioactive constituents in fugitive dust that escapes
before this burial of phosphate mine wastes are not believed to
162
-------
constitute a significant hazard because the dust receives limited
12
atmospheric distribution. In addition, recent monitoring
studies have shown that measured radioactivity from groundwaters
adjacent to tailings pond areas is less than the background
radiation in groundwaters of this area. This condition is
thought to result from the fact that the radium is tied up
chemically with the phosphate that is removed as product;
consequently, wastewaters from processing the phosphate ore
(e.g., from fertilizer plants) is probably more of a source of
radioactivity from radium. '
Waste rock from some mining operations (e.g., the few
asbestos mines) contains asbestos fibers. Although exposure to
this material is unlikely due to the small number of operations
handling minerals containing asbestos, its inhalation is
considered hazardous.
The fine particle size of most tailings renders them
particularly susceptible to wind erosion, especially in arid
regions of the West where most of the slurry water evaporates or
is recycled. The quantification of such fugitive emissions is
generally poor, but a study made of a tailings pond in Rhodesia
indicates losses of 95 tons (86 megagrams) of dust per day.
Dusts from uranium or phosphate mine waste and beneficiation
tailings contain radioactive materials such as radium 226. In
one radiation survey, uranium tailings dusts emitting gamma
radiation were detected as far as 0.4 mile (0.6 km) from the
pile. At one site direct gamma radiation of up to 3000 yR per
163
-------
hour was indicated near an inactive uranium tailings pile, and
radon gas concentration was also above normal background levels.
Water Pollution
How significantly mine waste affects water pollution depends
on the composition of the material, its pyrite content, its
solubility, the likelihood of its being exposed to air and
water, and the climate and physiography of the location. Another
factor that determines whether water pollution from mineral
resource solid wastes represents a hazard to human health is the
proximity of the source to populated areas. Special consideration
should be given to solid waste disposal in areas where
precipitation and runoff are copious.
The release of water from tailings impoundments can be a
serious problem. Considerable quantities of effluent contaminated
with heavy metals, suspended solids, beneficiation reagents,
radionuclides, and acidity can escape from poorly designed
tailings ponds or piles (by seepage, percolation, or overflow)
17 18
and adversely affect receiving surface or groundwaters. '
Seepage from a tailings pile in Ontario has been characterized
(Table 15).
Although there is a large potential for discharge of
contaminated water at both active and inactive sites, modern,
properly designed impoundment facilities can eliminate this
potential. Drainage ditches, canals, and retention basins are
used to provide control in areas where moderate to high levels of
precipitation create a threat of overflow. In arid regions,
164
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TABLE 15
CHARACTERISTICS OF SEEPAGE WATER FROM A TAILINGS PILE IN ELLIOT LAKE, ONTARIO*
(ppm, except pH)
Parameter
Concentration
Parameter
Concentration
o\
m
pH _ 2.0
Sulfate as 804 7,440.0
Acidity as CaC03 14,600.0
Ferric iron as Fe+3 1,450.0
Ferrous iron as Fe+2 1,750.0
Uranium 7.2
Zinc 11.4
Nickel 3.2
Cobalt 3.8
Copper 3.6
Manganese 5.6
Aluminum 588.0
Lead 0.67
Cadmium 0.05
Lithium 0.07
Vanadium 20.0
Silver 0.05
Titanium 15.0
Magnesium 106.0
Calcium 416.0
Potassium 69.5
Sodium 920.0
Arsenic 0.74
Phosphorus 5.0
Chemical oxygen demand 270.0
* Williams, R.E. Waste production and disposal in mining,
milling, and metallurgical industries. San Francisco. Miller
Freeman Publications, Inc., 1975. 489 p.
-------
where seepage is more of a problem than overflow, such seepage is
minimized by segregating slimes. In spite of these precautions,
most tailings ponds leak effluent into the soil or rock upon
18
which they are constructed. .
Many tailings ponds in the West are situated on unsaturated
soils some distance above the water table. Seepage from a pond
must move through the unsaturated layer to reach the water table.
It then flows down gradient. Gravity causes the downward flow
through this layer, and capillary forces cause some lateral
spreading. Seepage through heterogeneous soil profiles with
layers of varying permeability is often circuitous. The less
permeable strata slow or stop vertical motion and facilitate
horizontal movement of contaminated water. In dry climates, the
18
seepage may never reach the water table.
Studies'of a site having piles of uranium tailings indicate
that radium leached to a depth of about 2 ft (0.6 m) before it
reached the average background concentration of 1.5 pCi/g. In
beneficiation areas, radium contamination reached a depth of 4 ft
(1.2 m) in isolated locations. The highest level of contamination
averaged 75 pCi/g and extended to a depth of 7.5 ft (2.3 m)
before cobbles and water prevented further measurements.
Whether permeability changes diverted movement to the horizontal
was not determined by these studies. Only vertical measurements
were obtained directly beneath the tailings piles.
Slimes from phosphate beneficiation operations in Florida
contain radium 226. Concentrations of this material are
166
-------
apparently directly related to concentrations of suspended solids
in the slurry; fine clay slimes contain greater concentrations
than sands.
Groundwater, soil, and rock may be capable of reacting with
and removing contaminants from seepage. Such capabilities vary.
Fine-grained soils usually purify an effluent more effectively
than do coarse-grained soils or bedrock. Concentration of
contaminants in seepage may be reduced by dilution with native
groundwater, buffering of pH, precipitation by reaction with
dissolved constituents in the existing groundwater or solids in
the aquifer, filtration, volatilization and loss as a gas,
biological degradation or assimilation, sorption, and radioactive
decay. Some of these complex reactions in the subsurface are not
18
well understood.
Some mining operations dispose of tailings in existing
bodies of water. ' The best example of this is the discharge
of taconite tailings into Lake Superior by Reserve Mining Company.
The tailings contain asbestos fibers, which have an undetermined
impact on water quality.
As lower grade deposits of minerals are mined, the
production of solid waste during beneficiation increases, and
with it, the potential for degradation of ground and surface
waters.
Solid wastes from mining and beneficiating operations may
16 21
have a significant impact on surface waters. ' The problem of
acid drainage from waste heaps containing sulfur-bearing materials
167
-------
such as pyrite is well documented. Such drainage may be
considered hazardous on the basis of its corrosive properties
when the pH is less than 3. It has been estimated that some
SjjBOO miles of streams and 29,000 acres of impoundment and
8
reservoirs are seriously affected by surface coal operations.
Sources of acid and heavy metal pollution from mining operations
other than coal have also been investigated (Table 16), and the
impact on surface waters has been estimated (Table 17).
The formation of acid drainage begins when pyrite (FeS-)
(found in many ores) contacts both water and air and oxidizes to
22
produce soluble ferrous sulfate and sulfuric acid :
2FeS0 + 2H.O + 70. -»• 2FeSO. + 2H-SO.
22 2 424
The ferrous iron may oxidize further to form insoluble ferric
hydroxide and more acid:
4FeSO. + 00 + lOH.O -»• 4Fe (OH) , + 4H_SO,
42 2 324
Other reactions may form a complex sulfate or jarosite, thereby
22
adding additional acid.
These reactions occur naturally when outcrops of pyrite
minerals are weathered. If an outcrop is undisturbed, the
reactions take place slowly and the acid is quickly neutralized
by reaction with other minerals or with the natural alkalinity in
surface water.
The weathering of mine and beneficiation waste at both
active and inactive sites is greatly accelerated by removing the
material from its natural environment, increasing its surface
area by fracturing, and exposing it to a more rapidly oxidizing
168
-------
TABLE 16
SUMMARY OF SOURCES (OTHER THAN COAL) OF ACID AND
HEAVY METAL POLLUTION*
Number of
Casest
Arizona
Arkansas
California
Colorado
Idaho
Missouri
Montana
Nevada
New Hampshire
New York
North Carolina
Oregon
Tennessee
Vermont
Virginia
Washington
Wisconsin
Total
1
1
22
-------
TABLE 17
SUMMARY OF TYPES OF POLLUTION AND LENGTH OF STREAM AFFECTED
BY OTHER THAN COAL MINING*
Acid
State
Arizona
Arkansas
California
Colorado
Idaho
Missouri
Montana
Nevada
New Hampshire
New York
North Carolina
Oregon
Tennessee
Vermont
Washington
Wisconsin
Total
Number
cases
1
1
22
12
2
9
1
1
5
1
3
1
1
60
Stream
affected
(miles)
t
§
54
286
65
45
§
23
22
8.7
8.7
6.2
518.6
Metals
Number
cases
1
16
13
7
3
3
1
2H
1
1
48
Stream
affected
(miles)
t
39
271
8311
60
26
3.1
22
3.7
6.2
514
Sediment
Number
cases
1
2
5
1
4
2
2
1
1
4§§
1
1
25
Stream
affected
(miles)
§
§
24
31
e
64
35
43tt
9.9
37
1.9
8.7
254.5
Total
Number
cases
3
3
26
14
15
4
15
2**
1
1
1
5
4
3
1
1
99
Stream
affected
(miles)
t
§
55
302
831
84
100
§
3.1
43S§
23
37
8.7
8.7
6.2
753.7
• Martin and Mills, Water pollution caused by inactive ore and mineral mines.
t Lake affected 50 acres.
§ No estimate made.
11 Only four mining districts contributing to 78 miles of stream degradation. Length of
polluted stream from other polluted areas unknown.
@ No estimate available.
** One mine discharge causes an aesthetic problem because it is colored.
tt Most of problem from active operations.
5 § No data on length of stream.
Note: Metric conversion table in front matter.
170
-------
environment. Moreover, tailings often contain a high
concentration of minerals not recovered in the mining operation;
economic feasibility dictates which minerals the operator will
extract from the gangue. As sulfides of other metals (more
stable than pyrite) become susceptible to oxidation at a low pH,
21
they enter into solution and contribute more acid to the drainage.
This has been demonstrated in documented characteristics of
runoff from coal mine waste in Illinois (Table 18).
When the pH drops below 6.5, conditions become favorable for
the growth of chemosynthetic bacteria such as Ferrobacillus
ferrooxidans, also called "thiobacillus." These bacteria obtain
energy by oxidizing ferrous iron to ferric iron, and they act as
catalysts to speed up one of the slower steps of the oxidation
process. As the pH of the water continues to drop, action of the
bacteria accelerates until it reaches the bacteria's preferred
level of 4.3. At this degree of acidity, sulfides can be readily
22
oxidized and many heavy elements can enter into solution.
There is a relationship between pH and the solubility of
several metals in distilled water (Figure 22). The linearity of
many of the relationships may be expected only in the pH range
shown and should not be extrapolated further. Solubility, or
more realistically, stability, is also affected by temperature,
concentration of other dissolved ions, and the oxidation-reduction
(redox) potential of the solution.
Alkalinity is the ability of water to neutralize acid.
Bicarbonate and carbonate are the principal sources of alkalinity
171
-------
TABLE 18
CHARACTERISTICS OF RUNOFF FROM COAL MINE WASTES
IN THE SHAWNEE NATIONAL FOREST, SOUTHERN ILLINOIS*
Parameters
Acidity (as CaCO..)
pH
Total iron
Aluminum
Total manganese
Magnesium
Copper
Zinc
Calcium
+ 6
Chromium (Cr )
Total lead
Total cadmium
Sulfate
Average value in Palzo tract (ppm)
20,000
2.3
4,000
2,000
320
890
5.0
20.0
490
2.00
0.25
0.81
23,700
* Williams, R.E. Waste production and disposal in mining,
milling, and metallurgical industries.
172
-------
&
Q.
108
106
104
102
1
10-6
10-4
10-2
pH
Figure 22. Solubilities of oxides and
hydroxides of various metals are related to
pH.
Source: Martin and Mills. Water pollution caused
by inactive ores and mineral mines.
173
-------
in most surface waters. Alkalinity is probably released into
surface water by the dissolution of such minerals as limestone
and feldspar. The buffer system in most natural waters results
from the degree of carbonation and the potential for reaction
21
with calcareous materials.
When acid mine drainage combines with these waters, the
following reaction occurs :
[2(H+) + (SO^)] + [Ca++ + 2(HC03)~] + (Ca++ + SO^) + 2(^0) + 2(CC>2)
If the added acidity is greater than the capacity of the
buffer system, the natural buffer system is destroyed and the pH
21
will drop to a low steady-state value.
Waters with low pH will eventually meet with inflowing
buffered waters, and in most cases, neutral conditions in the
stream will be restored. The length of a stream exhibiting low
pH conditions depends on the amount of acid drainage reaching the
stream, the buffering capacity of upstream waters, and the
buffering capacity of waters later joining the stream. Ores
containing pyrite are usually found in acid igneous deposits.
Calcareous minerals are rare in these deposits; therefore the
21
impacted length of stream may be quite long.
When acid drainage is formed in the absence of calcareous
formations, the potential for metal dissolution is great. The
degree of acidity depends on the calcium carbonate content of the
rock stratum, the pH of the natural waters prior to mining
21
activity, and the physical state of the pyrite. Besides having
a buffering action, carbonate and bicarbonate can also form
174
-------
complexes with trace metals and thereby reduce metal toxicity in
23
natural waters.
The effect of waste heaps on water quality varies greatly.
At inactive sites, waste heaps may contain quantities of calcium
and aluminum-based minerals that decompose on weathering. These
materials can neutralize the acids produced and reprecipitate
heavy metals in new and often complex crystalline structures.
Over a period of time, elements become rearranged into a more
stable combination of compounds that tends to resist further
weathering. The extent of this stabilizing process is apparent
in that fresh spoils contain no sulfates, but a well weathered
22
spoil may contain as high as 5 percent calcium sulfate.
Because all reactions do not take place at the same rate,
quantities of soluble heavy metal salts that have not recombined
into stable molecules may still be present years after deposition,
Stability in a body of oxidized heavy metals is relative. Only
in arid regions are deposits of oxidized ores found at the
22
surface of the earth.
The production of sediments and their introduction into
receiving waters are natural and continuing processes, which have
been accelerated by many of man's activities such as tilling the
soil, construction, and mining. Sources of sediment from mining
activities include erosion of mine waste heaps, tailings piles,
21
dams, and access roads.
The potential for erosion of solid wastes from mining and
beneficiation depends on factors such as particle size
175
-------
distribution, slope, climate, and nature of the wastes. Because
particle size ranges from large boulders to fine slimes, no
generalization can be made as to typical particle size in
overburden piles. Tailings from a particular processing
technique, however, will exhibit characteristic particle sizes.
For example, gravity separation tailings average about 0.008 in.
(0.2 mm), and froth flotation tailings average about 0.002 in.
(0. 04 mm) .
The mechanics of erosion and sedimentation for mine waste
are the same as those for natural sources. The six basic sources
of erosion within a watershed are: (1) sheet and rill erosion,
(2) degradation of minor drainageways, (3) gully erosion, (4)
floodplain scour, (5) stream bed degradation, (6) stream bank
scour. All of these methods of erosion may apply to tailings
except, possibly, floodplain scour and stream bed degradation.
Sediment entering a stream is transported either as wash
load or bed load. The entrained fine particles of the wash load
are relatively insensitive to flow parameters, whereas the larger
particles of the bed load depend on the energy of the stream for
transport. Eroded tailings have a long-range impact on the
character of the wash load and a short-range impact on the bed
load. At one time it was not uncommon to discharge processing
slurry directly into a stream, where it either washed downstream
or, if carelessly placed, formed a blockage and caused stream
21
diversion; today tailings are placed by more controlled methods.
176
-------
The presence of Fe(OH) (ferric hydroxide) in acid mine
J «
drainage usually increases turbidity and suspended solids in
receiving waters. It also contributes to the formation of sludge
banks and a coating that covers stream beds and lake bottoms.
This coating can build up to a thickness of an inch (2.54 cm) or
more in slow moving streams, or it can be scoured and create
turbidity in more rapid streams before eventually being deposited
downstream.
Surfaces of freshly precipitated and disordered ferric
hydroxide and manganese dioxides are active sites for immobilizing
many dissolved ionic species by specific adsorption and
coprecipitation. ' ' The ability of metal species to
associate with other dissolved and suspended components of an
aquatic system is of major importance.
Runoff can affect surface waters in many ways. Its
22
characteristics include :
0 Is strong in acidity; contains free sulfuric acid.
Seepage from sulfide-containing tailings or spoil dumps
is representative.
0 Is high in turbidity; contains both settleable and
colloidal insoluble inorganic material.
0 Has high concentrations of heavy metal ions; frequently
contains toxic metals in concentrations higher than
allowed for discharge into public waters.
0 Contains materials that have a chemical or a biochemical
oxygen demand, some of which may be toxic to animals or
plants.
0 Contains high concentrations of metallic and nonmetallic
ions that are not toxic in moderate concentrations.
0 Is frequently high in sodium and calcium.
177
-------
Effects On Physiography
Improper disposal of mineral resource solid wastes can
significantly alter the physiography of a region. Although most
of_ these physiographic effects are not caused by the hazardous
characteristics of solid waste, they are nevertheless important.
The effects range from aesthetic and land-use considerations to
erosion and contamination of aquifers.
Extremes in pH, toxic constituents, improper grading, lack
of nutrients, and improper soil texture sometimes prevent
revegetation of areas covered with mineral resource solid wastes.
For example, waste materials from surface mining often have a pH
of 4.0 or less and cannot support vegetation. One survey of
spoil banks at a variety of surface mines revealed that 1 percent
of those sampled had a pH of less than 3.0 and 47 percent had a
o
pH in the range of 3.0 to 5.0. Although enough free acid might
be leached from spoil banks in 3 to 5 years to permit revegetation,
such leaching will not improve soil conditions if more pyrite is
exposed to the surface by erosion. Effects on vegetation are
addressed further in the subsection on flora and fauna.
The design of spoil banks, tailings ponds, waste heaps, and
impoundments plays an important role in determining the
environmental effect of such structures. Downslope spoil piles
2 6
at contour surface mines pose a threat of landslides. The
improper construction of tailings ponds can result in flooding or
collapse.
178
-------
Currently, the design and construction of impoundments are
generally based on sound engineering principles, and they are
usually well maintained at active sites. Design and construction
of impoundments at inactive sites and some older active sites,
however, are often poor, and they receive little, if any,
maintenance.
Failure of a coal refuse bank can result in severe property
damage and loss of life. In 1972 a failure at Buffalo Creek, .
West Virginia, left 118 persons dead, 7 persons missing, and over
500 homes destroyed. The disaster was apparently caused in part
by overtopping a coal mine refuse embankment that impounded a
settling pond in a small valley. The pond had only 4 ft (1.2 m)
of freeboard and the embankments were constructed on slime layers
in other ponds.
The Buffalo Creek failure was not an isolated incident;
another widely publicized diaster occurred in Aberfan, Wales, in
27
1966, resulting in the death of 144 school children. A study
conducted by the Department of the Interior following the Buffalo
Creek incident concluded that coal refuse embankments have the
following problems in common: (1) spillways are either lacking
or improperly designed, (2) embankments are constructed
improperly, (3) sludge disposal method is improper, (4) freeboard
is inadequate, (5) burning occurs. (Burning reduces the volume
of refuse material, which, in turn, causes slumping or cracking
of the dam surface.)
179
-------
Certain regions are particularly ill-suited for the disposal
of mineral resource solid wastes. These environmentally
sensitive areas (considered in Section 257.3 of the Resource
Conservation Recovery Act) include wetlands, floodplains,
permafrost areas, critical habitats of endangered species, and
28
recharge zones of sole source aquifers. Since most of these
areas are not normally used for disposal of mine and beneficiation
wastes, this section of the act is generally concerned with other
types of solid wastes; however, some considerations do apply.
Recharge zones for sole source aquifers are particularly
susceptible to contamination by leachate from mineral resource
wastes. For example, central Colorado, which contains many
mining operations, has an average annual precipitation of 15 to
20 in. (38.1 to 50.8 cm), of which 1 to 10 in. (2.54 to 25.4 cm)
is runoff. The remainder presumably recharges groundwater
reservoirs, which account for 17 percent of the State's water
usage. Arizona is another area of considerable mining activity
that relies heavily on groundwater. Infiltration of heavy metals
and other harmful components of leachate must be carefully
avoided in these areas.
Many consider the mere presence of waste heaps and tailings
impoundments to be an adverse environmental impact. They are
viewed as obtrusive or conspicuous. Containment areas also
require considerable amounts of land that may have other uses.
If reclamation is practiced, this land-use consideration may only
be temporary, although reclaimed land often is not returned to
180
-------
its original use. When viewed perspectively in relation to
other activities requiring large amounts of land (e.g., airports
and parking lots), such land-use considerations become less
significant.
Effects on Flora and Fauna
Flora and fauna are affected both directly and indirectly by
mineral resource solid wastes. The most immediate direct effect
is the destruction of habitats by waste impoundment that covers
Op o Q
a large area. ' Noises and dust created by waste handling
equipment also affect certain species. '
Indirect effects are insidious and difficult to control.
The indirect effect on water is the most significant. The
environmental impact of acid drainage on microorganisms in streams
can be far-reaching because these organisms are responsible for
the degradation of organic matter. Acidity and trace metal
toxicity are the primary problems caused by indirect pollution.
Low pH is known to kill or impede most of the microbial
populations indigenous to streams, leaving acidophilic bacteria
and fungi (particularly yeasts) as the dominant flora, and trace
24
metals can accumulate in aquatic food chains.
A comparison of a lake polluted with acid mine drainage with
an unpolluted lake indicated a lack of vegetation and dissolved
oxygen in portions of the polluted lake, a general lowering of pH
and alkalinity, and an increase in sulfate. A reduction in fish
populations and decreased abundance and diversity of planktonic
rotifers were also noted in the polluted lake.
181
-------
The chemical and physical states of trace elements are of
considerable importance in ascertaining the impact the metals
*"") O 1 A
will have on biota. ' Recent investigations show that
formation of inorganic or organic complexes sometimes reduces
23
metal toxicity to fish and aquatic invertebrates. Chelated :
copper, for example, is not easily metabolized and is therefore
23
relatively nontoxic to aquatic species. This complexing is not
likely to occur in waters with lower pH, but the possibility of
metals complexing increases as more alkaline waters join the
stream.
The nature of runoff and drainage from mineral resource
24
waste suggests additional effects on aquatic flora and fauna.
The mechanical action of large amounts of sediment from eroded
waste piles can interfere with respiration in fish. These
sediments may also contain trace elements that are sorbed onto
the particle surfaces. Because aquatic invertebrates are, for
the most part, filter feeders, sorbed metals may enter the food
24 25
chain in this manner. ' Increased turbidity in receiving
waters can adversely affect the photosynthesis of aquatic flora
by reducing the penetration of sunlight; it can also accumulate
in quantities sufficient to destroy benthic organisms. These
effects are in addition to the more direct and immediate effects
of lowered pH and increased sulfate. Reduction of photosynthetic
activity can, in turn, result in a decrease of dissolved oxygen,
23
as evidenced in the lake study mentioned earlier. The process
of acid formation also consumes dissolved oxygen.
182
-------
The sulfuric acid in mine drainage or beneficiation effluent
is also toxic to fish. Toxicity to fish has been recorded using
several sulfuric acid concentrations with varying water conditions
(Table 19). When certain beneficiating reagents are leached
from tailings piles (e.g., cyanide), they also may have toxic
effects on aquatic biota.
Heavy metals leached from tailings affect terrestrial plants
in various ways. Because metal concentrations in plants and soil
associated with toxicity symptoms are unique for each combination
25
of plant-soil variables, they may be of little general value.
Thus the relative concentrations of various metals may be more
important than the absolute quantity of individual metals in
25
determining toxicity to plants.
Various species differ decidedly in uptake and accumulation
of metals and also in sensitivity to the metals. Ragweed has
been known to grow luxuriantly in soil with high zinc
25
concentrations, whereas surrounding vegetation was stunted.
The chemical form of an element is an important factor in
plant uptake. Lead oxide is readily absorbed, whereas lead
sulfide (galena) is not. The presence or absence of essential
nutrients and soil pH also affect lead uptake. In general, heavy
metal uptake by plants is greater at a soil pH of 5.5 than at
25
6.5 to 7.0. This would suggest that soil that has been
subjected to mine drainage of low pH and high metal concentration
would be a suitable substrate for metal uptake by plants.
183
-------
TABLE 19
CONCENTRATIONS OF SULFURIC ACID THAT ARE
TOXIC TO FISH*
Concentration of Length of
Sulfuric acid (ppm) exposure
1.2
6.0 to 8.0
6.25
7.36
10.0
24.5
26.0
42
49
59.0
71.2
80.1
110 to 120
138
167
6 hours
24 hours
60 hours
24 hours
15 minutes
96-hour
TL t
m
48-hour
TL t
m
1 to 1.25
hours
6 hours
4 hours
48 hours
Type of Species of
water fish
Sunf ish
Distilled Minnow
Trout
Distilled Bluegill
Gamefish
Bluegill
Tap Minnow
Turbid Mosquito-fish
Tap, 20C Bluegill
Sunf ish
Soft, pH 3.2 Goldfish
Pickerel
Whitefish
Hard, 20C Minnow
Hard, pH 4 Goldfish
Fish
* Hawley, J.R. The use, characteristics, and toxicity of
mine-mill reagents in the Province of Ontario. Toronto, Ontario
Ministry of the Environment, 1977. 255 p.
t TL = Median tolerance limit.
m
184
-------
Accumulation of trace metals in vegetation may have an
effect on herbivorous wildlife and, ultimately, on predators;
however, an effect on the food chain resulting from environmental
contamination by mining industry solid waste has yet to be
demonstrated.
Impacts on Human Health and Welfare
Exposure to hazardous constituents of mineral resource solid
wastes can occur in various ways, but the most significant medium
of exposure is water. The long-term effects of acidity and
concomitant high metal concentration in acid drainage on
populations are unknown, as are the effects of low pH alone.
Drainage can contain high concentrations of ferric and ferrous
iron, manganese, zinc, magnesium, aluminum, calcium, cadmium,
copper, or other metals (Tables 15 and 18). Although the toxic
properties of individual metals in the effluent may be known, it
cannot be assumed that the effect of the stream as a whole is
simply the sum of the effects of the individual components. Some
biologically essential elements such as calcium, copper,
selenium, iron, and zinc seem to mitigate the adverse effects of
other metals such as cadmium or lead; other combinations may
produce greater than additive effects. Some essential trace
metals can also act as environmental hazards if the homeostatic
mechanisms maintaining them within normal physiological limits
32
become unbalanced.
An assessment of the potential hazards of metallic elements
or compounds found in mineral resource wastes should consider the
185
-------
form of the element (valence state), its chemical and physical
properties, rates of absorption and excretion, metabolic pathways,
target organs, and route of exposure.
A considerable amount of data are available on the toxicology
of individual metals, from which a tentative classification of
the environmental and biological impacts has been derived
(Table 20). Elements that accumulate in the body have the
greatest potential for causing disease, and even biologically
essential metals can adversely affect environmental toxicity.
Data have also been collected that compare typical human body
burdens with crustal abundances (Table 21). These data show the
obvious accumulation of certain metals.
Knowing which organs are susceptible to the action of
specific metals may aid in predicting the systemic effects of
combinations of metals (Table 22). The U.S. Public Health
Service established tolerance levels for metals in drinking water
and compared the levels with the results of a sampling of
community water supplies (Table 23). In some cases excess
quantities of metals are present in water supplies. Carcinogenesis
and teratogenesis must be considered where long-term exposure to
excess quantities of certain metals is suspected (Tables 24 and
25).
Toxicity of asbestos fibers in taconite tailings has not
33
been established for the oral route of exposure ; however,
inhalation of asbestos has been linked with cancer. ' '
186
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TABLE 20
A CLASSIFICATION OF THE EFFECTS OF METALS*t
Moderate to Factors in
severe environmental Limited
Essential industrial nonoccupa t ional Accidental industrial
Metal for mammals hazard disease poisoning hazard
Aluminum x
Antimony x x
Arsenic x x x
Barium x
Beryllium x x
Bismuth x
Boranes
Cadmium x x x
Cesium x
Chromium (III) x
Chromium (VI ) x
Cobalt x x
Copper x xx
Gallium x
Germanium x
Gold x
Hafnium x
Indium x
Iridium x
Iron x xxx
Lanthanons x
Lead xxx
Magnesium x x
Manganese x x
Mercury xxx
Metal hydrides
and Car bony Is x
Molybdenum x x
Nickel x x
Niobium x
Palladium x
Platinum x
Rhenium x
Rubidium x
Selenium x x x
Silver x
Strontium x x
Tantalum x x
Tellurium x x
Thallium x
Tin (organic) x
Titanium x
Tungsten ?
Uranium x
Vanadium x x ?
Zinc x ? x
Zirconium x
Associated
with mine
drainage
x
x
X
X
X
X
X
X
X
X
X
X
X
* Casarett, L.J., and J. Doull. Toxicology, the basic science of poisons. New York,
Macmillan Publishing Co., Inc., 1975. 768 p.
t Martin and Mills. Water pollution caused by inactive ore and mineral mines.
187
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TABLE 21
BODY BURDEN, HUMAN DAILY INTAKE, AMD
CONTENT IN THE EARTH'S CRUST OF SELECTED ELEMENTS*
Element
Aluminum
Antimony
Arsenic
Barium
Boron
Cadmi urn
Calcium
Cesium
Chromium
Cobalt
Copper
Germanium
Gold
Iron
Lead
Lithium
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Niobium
Potassium
Rubidium
Selenium
Silver
Sodium
Strontium
Tellurium
Tin
Titanium
Uranium
Vanadium
Zinc
Zirconium
Human body
burden
(mg/70 kg)
100
<90
<100
16
<10
30
1,050,000
<0.01
<6
1
100
trace
<1
4,100
120
trace
20,000
20
trace
9
<10
100
140,000
1,200
15
<1
105,000
140
600
30
<15
0.02
30
2,300
250
Daily
intake
(mg)
36.4
0.7
16
0.01-0.02
0.018-0.20
0.06
0.3
3.2
1.5
15
0.3
2
500
5
0.02
0.35
0.45
0.60
10
0.06-0.15
2
0.6
17
0.3
2.5
12
3.5
Earth's
crust
(ppm)
81 ,000
0.2
2
400
16
0.2
36,000
1
200
23
45
1
0.005
50,000
15
30
20,900
1,000
0.5
1
80
24
25,900
120
0.09
0.1
28,300
450
0.002
3
4,400
2
no
65
70
* Casarett and Doull. Toxicology, the basic
science of poisons.
188
-------
TABLE 22
TARGET ORGANS OF METALS*
•total*
Gaatrointeitmal
tract
•apiratory
tract CNS
Cardiovaacular
•y»t«TT Liver Skin Blood Kidney
one Endocrine
Alujr.inuir
Antiajony
Xraenic
Bumuth
ftoranes
Eor or,
Cadmiur
Chror.iur
Cobalt
Copper
Calliuir
Cermar.iujT,
Cold
Bafniu*
2 nd i uir.
Iron
Lanthanont
Lead
Lithiur
Magn*§iun
Hanqaneae
•tercury
Metal hydrides
Molybdenun
Nickel
Niobiur
Oaniuir.
Palladium
Platinum
Rhodiurr.
fcubidiuir
Silver
Strontium
Tantaluv
Tellurium
Thallium
Tin (organic)
Titanium
Tun? a ten
Uranium
Vanadiu*
Sine
Sirconiuai
* Ca»*rett and Ooull. Toaicology, the baaic aci*DC« of
pole
189
-------
TABLE 23
TOLERANCE LEVELS FOR METALS IN DRINKING WATER AND RESULTS OF
SAMPLING OF COMMUNITY WATER SUPPLIES IN 1969*t
Element
Arsenic
Barium
Boron
Cadmium
Chromium (Cr )
Copper
Iron
Lead
Manganese
Selenium
Silver
Uranium (Uranyl)
Zinc
* Casarett
t From U.S.
Limits
Mandatory
upper
0.05
1.0
5.0
0.01
0.05
0.05
0.01
0.05
**
(ppm)
Desirable
upper
0.01
1.0
1 .0
0.3
0.05
5.0
5 .0
Maximum
concentrations
found (ppm)
0. 10
1.55
3.28
3.94
0.7911
8.35
26.0
0.64
1.32
0.07
0.03
Not included
13.0
Number of
total of
Mandatory
5 .
. 2§
0
4
5
37
10
0
—_!_•__ ''.!_.•- .._ •
samples of a
2595 exceeding
Desirable
10
20
42
223
211
8
and Doull. Toxicology, the basic science of poisons.
Public Health Service: Community Water
Supply Study: Analysis
of Nation
Survey Findings.
U.S. Department of Health, Education, and Welfare, Washington, D.C., 1970.
§ Not measured in all samples.
H Total Chromium measured.
** Proposed.
-------
VD
TABLE 24
METAL CARCINOGENESIS IN EXPERIMENTAL ANIMALS*
Metal
Beryl liu»
Cadaitio
ChromliM
Cobalt
Copper
Iron
Lead
nickel
Selentun
Zinc
I Han tun
AluBlnun
Sliver
Mercury
Compound
AnBeSIOj. BeO
BeO. BeS04. BeHPO,
CdS, CdO. CdCI2. CdS04
Cd porter
CdClj
Metallic Cr
Roasted chronlte ore
CaCr04. CrOj. Na2Cr?0;
Cr?0j
CaCr04
Metallic Co. Co pooder
CoO. CoS
CuS04
1 ron-carbonhydra te
completes
Pbj (P04)?. Pb (C2Hj02)2
Tetraettiyl lead
Pb (C2Hj02)2. ?Pb (OH)2
HI dust. HI (CO),
Nlckelocene. Nl dust
K'jSj dust. NIO dust
lit pellets
HljS2 discs
NH4KSe. grain vilh Se.
Ma2. SeO,. bls-4-acet-
aninophenyl Sehydroiide
I** Znd
4. ZnCI2
1 1 tanocene
Al foil
Ag (oil
Ag colloid
1 tqutd oercury
Species
Rabbits, mice, rats
Monkeys, rats
Rats, ntce
Chickens
Rabbits
Rats, ntce
Rats
Rats, rabbits
Chickens
Rats. nice, rabbits
Rats
Mice
Rats, mice
Guinea pigs, rats
Rats
Cats
Rats
Rats
Chickens
Rats, nice
Rats
Rats
Bats
Rats
Route
IV
Inhalat ton
SC. IM
Intratestlcular
Intraosseous
IN. IP. SC
Intrapleural
Intrabronchl- 1
SC. IM
Intraosseous
Intratestlcular
IM. SC
SC
SC
Dietary
Inhalation
IM. SC
Imptanation in nasal
sinuses
Dietary
Intratestlcular
IM
Implementation
Implementat ion
IV
IP
Type of tumor
Osteosarcomas
Pulmonary carcinomas
Sarcomas
Leydiqlomas
leratona
Sarcomas
Sarcomas
Squamous
Cell carcinomas
Squamous cell and adenocarctnomas
Sarcomas
Teratoma
Sarcomas
Renal adenomas and carcinomas
Lymphomas
Renal adenomas
Renal and testtcular carcinomas
Anaplastlc and adenocarctnomas
Squamous cell, anaplastic and adenocarctnows
Sarcomas
Squanous cell and adenocarcinomas
Hepatomas
Sarcomas
Thyroid adenomas
Leydtglomas. serniinoM
Teratomas
Fibrosarcomas. hepatonas
Lymphomas
Sarcomas
Fibrosarcomas
Tumors (?)
Spindle cell sarcomas
• Casarett and Ooull. To>lcolo]y. the basic science of poisons.
-------
TABLE 25
EFFECTS OF METALS ON REPRODUCTION*
Metal
. Species
Test
Results
VO
Arsenic
Cadmium
Cobalt
Copper
Indium
Lead
Lithium
Manganese
Mercury
Molybdenum
Nickel
Selenium
Tellurium
Titanium
Zinc
Mouse
Hamster, rat
Mouse
Hamster
Hamster
Hamster
Hamster
Mouse
Rat
Hamster
Mouse
Hamster
Human
Mouse, rat
Hamster
Mouse
Hamster
Rat
Hamster
Livestock
Hamster
Mouse
Rat
Rat
Hamster
Rat
5 ppm arsenite in drinking water, three generations
Teratogenic parenteral
10 ppm 1n drinking water, three generations
Teratogenic parenteral
Teratogenic
Teratogenic
Teratogenic parenteral
25 ppm in drinking water, three generations
25 ppm In drinking water, three generations
Teratogenic parenteral
Teratogenic
Teratogenic
Epidemiologic
Teratogenic (methyl mercury)
Teratogenic (mercuric acetate and phenylmercurlc
acetate)
10 ppm (molybdate) in drinking water,
three generations
Teratogenic
5 ppm in drinking water, three generations
Teratogenic parenteral
Epidemiologic
Teratoqenic
3 ppm (selenate) in drinking water,
three generations
Teratogenic (dietary 500 to 3500 ppm)
5 ppm (titanate) 1n drinking water,
three generations
Teratogenic parenteral
Dietary administration dam
Increased male to female ratio, reduced litter size
Head changes, exencephaly, urogenital abnormalities
Failure to reproduce three generations, congenital
abnormality of the tail, runting. death before
weaning
Abnormalities face and palate
Not teratogenlc
Not teratogenlc
Abnormalities of limb buds
Failure to reproduce three generations, runting, death
before weaning
Death before weaning, runting
Malformation tail bud
Resorptlon, cleft palate
Not teratogenic, embryocldal
Mental retardation, neuromuscular effects
Behavior effects, changes In central nervous system
No clear-cut effects
Deaths before weaning, runting
Not teratogenlc embryocldal
Death before weaning, runting, reduced litter size,
reduced number of males In third generation
Embryotoxlc, few general malformations
Teratogenic
Not teratogenlc
Increased male to female ratios, death before
weaning, runting
Hydrocephalus
Runting. death before weaning, male to female
ratio reduced
Mild teratogentc effect
Increased hydrocephalus
* Casarett and Doull. Toxicology, the basic science of poisons.
-------
Impact on human health through atmospheric exposure results
primarily from particulate emissions but also from radon gas
emission in the case of uranium tailings. Because most mining
operations are located in sparsely populated areas, human
exposure to such particulate emissions is probably minor. A
possible exception is exposure to fugitive dust from some quarry
operations. Most of this dust, which may contain silica, is
generated by the operations themselves, rather than from waste
heaps.5'6
The hazard of fugitive dust from uranium tailings is also
slight; radon gas from tailings piles and the subsequent inhalation
of radon daughters account for most of the total dose to persons
living near the Slick Rock, Colorado, uranium mining/beneficiating
site. Gamma radiation exposure from the piles is virtually zero
because few persons live or work within 0.2 mile (0.3 km) of
those piles whose gamma radiation is above background level.
The significance of long-term radiation exposure to human
health has been studied extensively for many years. Because the
diseases that usually result from long-term exposure to low-level
radiation (e.g., lung cancer and leukemia) also have many other
causes, it is difficult to determine the specific cause and
effect in any given case. Therefore, the projected health
impacts of low-level radiation exposures are usually based on
observed effects of high exposures, on the premise that the
effects are linear. Considerable information is available on the
high incidence of lung cancer in uranium miners exposed to radon
193
-------
and radon daughters in mine air. This information provides a
basis for calculating the probable health effects of low-level
exposure to large populations, although such projections must be
recognized as highly uncertain. The combined effect of radon
daughters with other carcinogens is one complicating factor. For
example, the incidence of lung cancer among uranium miners who
smoke is far higher than can be explained on the basis of either
smoking or the radiation alone.
Calculations based on measurements of radon concentrations
in excess of background values indicate that the average
radon-induced lung cancer risk due to waste piles in the area
within 0.5 mile (0.8 km) of the Slick Rock sites is 1.3 x 10
per person per year, or less than one-tenth the average cancer
-4 17
risk due to all causes for Colorado residents (1.8 x 10 ).
The 25-year cumulative health effects of above-background
concentrations of radon have been calculated for two static
populations on the basis of current and increased mining
activity. A comparison of pile-induced radium 222 with
background concentrations is shown below:
25-year Cumulative Health Effects 0 to 0.5 mile from Edge of Piles
Projected Population Growth Pile-Induced RDC Background RDC
Static population (71) 0.02 0.12
Static population (142) 0.05 0.24
Pile-induced radon daughter health effects are approximately 18
percent of the background radon daughter health effects. The
exposure and consequent risk will continue as long as the
radiation source remains in its present location and condition.
194
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Although the greatest percentage by weight of fugitive
particulate emissions from mineral resource solid wastes settles
within a short distance of the source, a large percentage of
particulates in the smaller size range are transported greater
distances. This smaller size range represents the greatest
hazard to human health for two reasons. First, only particles
smaller than 2 micrometers are likely to penetrate into the
deeper portions of the lung and deposit in the alveoli, and only
those smaller than 0.5 to 0.1 micrometers will be subject to
diffusion within the lung. Second, these smaller particulates
exhibit greater surface area per unit weight and are more likely
to contain adsorbed polycyclic organic matter. Although the
presence of polycyclic aromatic hydrocarbons (PAH) in fugitive
dust from burning coal mine waste heaps could make exposure to
this dust hazardous to human health, this hazard is partially
mitigated by the isolation of most coal mines.
Although BaP is a known carcinogen, its presence in emissions
from coal refuse fires must be considered a minor health hazard
when viewed in perspective. Recent estimates indicate that 50
tons (45 Mg) per year of this compound is emitted from coal
refuse fires, compared with 500 tons (454 Mg) per year from heat
and power generating sources and 300 to 500 tons (272 to 454 Mg)
per year from all refuse burning. Moreover, these other sources
are usually located nearer population centers. The concentration
of BaP in cigarette smoke also presents a much more significant
hazard.
195
-------
In summary, even though mineral resource solid wastes could
have adverse effects on human health, the significance of this
potential health hazard is lessened by the isolation of most
mining/beneficiating operations. The nonhazardous impact of
waste appears to be greater.
196
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REFERENCES FOR SECTION 5
1. Williams, R.E. Waste production and disposal in mining,
milling, and metallurgical industries. San Francisco.
Miller Freeman Publications, Inc., 1975. 489 p.
2. PEDCo Environmental Specialists, Inc. Evaluation of
fugitive dust emissions from mining, Task 1 report:
identification of fugitive dust sources associated with
mining. Environmental Protection Agency Contract No.
68-02-1321. Cincinnati, 1976. 78 p.
3. Donovan, R.P., et al. Vegetative stabilization of mineral
waste heaps. Environmental Protection Agency, Washington,
National Technical Information Service. PB-252 176. 1976.
305 p.
4. Axetell, K., Jr. Survey of fugitive dust from coal mines.
Environmental Protection Agency Contract No. 68-01-4489.
Denver, 1978. 114 p.
5. Midwest Research Institute. A study of waste generation,
treatment, and disposal in the metals mining industry.
Environmental Protection Agency Contract No. 3952-D.
Washington, 1976. 403 p.
6. Chalekode, P.K., et al. Source assessment document No. 30;
crushed granite. Environmental Protection Agency Contract
No. 68-02-1874. Research Triangle Park, North Carolina.
1975.
7. Office of Water and Hazardous Materials. Development document
for interim final effluent guidelines and standards of
performance mineral mining and processing industry.
Washington, Environmental Protection Agency
EPA 440/l-76/054a. 1976. 432 p.
8. Strip and Surface Mine Study Policy Committee, U.S. Department
of the Interior. Surface mining and our environment, a
special report to the nation. Washington, U.S. Government
Printing Office, 1967. 125 p.
9. Office of Air Quality Planning and Standards. Environmental
Protection Agency, Preferred standards path report for
polycyclic organic matter. Durham, October 1974.
10. Stern, A.C. The effects of air pollution, H is air pollution,
3d ed. VII. New York Academic Press, Inc., 1977.
11. College of Engineering, University of Florida. Natural
radiation exposure: assessment, summary. Gainesville,
Florida, University of Florida. 1976.
197
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12. Personal communication. R. S. Hearon, International
Minerals and Chemical Corporation, to J. S. Greber,
PEDCo Environmental, Inc., March 28, 1978.
13. Personal communication. Dr. J. E. Garlanger. Ardaman and
Associates, Inc., Orlando, Florida, to R. S. Amick, PEDCo
Environmental, Inc., August 30, 1978.
14. Personal communication. Dr. W. E. Bolch, University of
Florida, Gainesville, Florida, to R. S. Amick, PEDCo
Environmental, Inc., September 14, 1978.
15. Greber, J.S., et al. Assessment of environmental impact of
the mineral mining industry. Cincinnati, Environmental
Protection Agency Contract No. 68-03-2479. 1977.
16. Down, C.G., and J. Stocks. Environmental problems of tailings
disposal. Mining Magazine 137(1); 25-33, July 1977.
17. Ford, Bacon, and Davis Utah, Inc. A summary of the phase
II - Title I engineering assessment of inactive uranium
mill tailings Slick Rock sites, Slick Rock, Colorado.
U.S. Department of Energy Contract No. E(05-1)-1658.
Grand Junction, Colorado. 1977.
18. Mead, W.E., and G.W. Condrat. Groundwater protection and
tailings disposal. In American Society of Civil Engineers
National Convention, Denver, November 3-7, 1975. 15 p.
19. Toland, G.C., and R.E. Versaw. Design of impoundment and
evaporation ponds and embankments for cyanide and other
toxic effluents. Society of Mining Engineers of AIME
Preprint No. 75-B-313. Salt Lake City, 1975. 19 p.
20. Oxbury, J.R., et al. Potential toxicity of taconite tailings
to aquatic life in Lake Superior. Journal Water Pollution
Control Federation, February 1978. pp. 240-251.
21. Martin, H.W., and W.R. Mills, Jr. Water pollution caused by
inactive ore and mineral mines. U.S. Environmental
Protection Agency, EPA-600/2-76-298. Washington, U.S.
Government Printing Office, 1976. 195 p.
22. Corwin, T.K., et al. Environmental assessment of the domestic
primary copper, lead, and zinc industries. Environmental
Protection Agency Contract No. 68-02-1321 and 68-02-2535,
Cincinnati, 1977. 390 p.
23. Roder, R.M. Public intervenor: Base metal mining and
processing. A Report to Department of Justice, State of
Wisconsin contract, Madison, 1977.
198
-------
24. Singer, P.C. Trace metals and metal-organic interactions in
natural water. Ann Arbor, Ann Arbor Science Publishers,
Inc., 1973. 380 p.
25. Oak Ridge National Laboratory. Environmental, health, and
control aspects of coal conversion: an information
overview. Energy Research and Development Administration
Contract No. W-7405-eng-26. 1976.
26. Office of Water Planning and Standards. Water quality
management guidance for mine-related pollution sources
(new, current, and abandoned). Environmental Protection
Agency, EPA 440/3-77-017, Washington, 1977.
27. Workshop report: Research needs for mining and industrial
solid waste disposal. Colorado State University. Fort
Collins, Colorado, July 22-23, 1976. National Technical
Information Service. PB-269 247.
28. Environmental Protection Agency. Solid waste disposal
facilities; proposed classification criteria. Federal
Register February 6, 1978, Part II. Washington, U.S.
Government Printing Office.
29. Bureau of Reclamation. Final environmental statement; El
Paso coal gasification project San Juan County, New Mexico
VI. Department of Interior FES77-03. Washington,
Department of Interior, 1977.
30. Bureau of Reclamation. Final environmental statement; WESCO
coal gasification project and expansion of Navajo Mine by
Utah International, Inc. San Juan County, New Mexico.
Department of Interior FES 76-2, Washington, 1976.
31. Hawley, J.R. The use, characteristics, and toxicity of
mine-mill reagents in the Province of Ontario. Toronto,
Ontario Ministry of the Environment, 1977. 244 p.
32. Karaffa, Mark A., J.K. Smith, and A.C. Worrell III. Health
effects assessment of the domestic primary nonferrous
metals industries. Environmental Protection Agency
Contract No. 68-02-1321. Cincinnati, (Draft) March 1977.
33. Casarett, L.J., and J. Doull. Toxicology, the basic science
of poisons. New York, Macmillan Publishing Co., Inc.,
1975. 768 p.
34. Rossiter, C.E., et al. Radiographic changes in chrysotile
asbestos mine and mill workers in Quebec. Archives of
Environmental Health, 24(6)388-400, 1972.
35. Corbett, J., et al. The health of chrysotile asbestos mine
and mill workers of Quebec. Archives of Environmental
Health, 28(2)61-68, 1974.
199
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SECTION 6
LAWS AND REGULATIONS
This section presents an overview of laws and regulations
affecting the mining industry in general and the production and
disposal of solid wastes from active and abandoned mines in
particular. Because the regulatory setting in which the mining
industry operates includes several distinct and independent
environmental control programs on Federal, state, and local
levels, some opportunity exists for duplication (and sometimes
emission) of regulatory authority. An attempt is made to
identify these areas of overlap or omission to determine if there
is a need for additional or revised regulations. No recommendations
are made, however, because the intent of this document is only to
assist EPA in making this determination.
Mining laws that authorize and control prospecting, claim
procedures, leasing, development, and extraction of minerals on
public lands have existed for many years. The cornerstone of the
Federal mineral leasing program is the U.S. Mining Law of 1872.
Prior to the enactment of this statute, the Federal Government
maintained a policy of benign neglect with regard to mineral
claims. In subsequent years, however, Congress passed a series
of acts that broadened and defined the power of the Federal
Government to control all types of mining operations on public
200
-------
lands. Among these were the Mineral Leasing Act of 1920, the
Mineral Leasing Act for Acquired Lands, and the Materials Act of
1947. Despite this continuing growth in the number of laws
governing mining operations in general, laws and regulations
dealing specifically with the environmental effects of mining
operations are of relatively recent origin.
Regulations under the Federal mineral leasing program are
administered primarily under the authority of two agencies of the
Department of Interior, the Bureau of Land Management and the
Geological Survey. Although these regulations deal specifically
with mining operations, they are broad in scope and treat the
environmental effects of mining only peripherally.
The 1969 passage of the National Environmental Policy Act
(NEPA) placed new emphasis on the environmental effects of
mining on public lands, but the control of solid wastes from
mining operations on either public or private lands still
remained in the background. Further, the national environmental
legislation over the last 10 years had no measurable effect on
the control of solid wastes. The solid waste area has remained
almost exclusively under the purview of state government. Such
Federal environmental legislation as the Clean Air Act and the
Federal Water Pollution Control Act has only indirectly affected
sources of solid wastes. The more recently passed Surface Mining
Control and Reclamation Act and Resource Conservation and
Recovery Act (RCRA), however, provide the potential for making
201
-------
Federal laws a direct and uniform force within all areas of the
mining industry, including the control of solid wastes.
Regulations governing the mining industry differ greatly
from state to state, both procedurally and in substance. These
differences are being somewhat lessened by growing Federal
involvement, especially in areas of air and water pollution
control and mine safety. They should be lessened even more as a
result of the Surface Mining Control and Reclamation Act, which
places on the states the primary responsibility for developing,
issuing, and enforcing regulations that are consistent with a
Federally approved state plan.
Federal Regulations
The responsibility for regulating disposal and management of
mineral resource wastes is spread among various departments and
agencies of the Federal government. In some instances,
department or agency authority is unique to a particular area.
In many other cases, the responsibilities of several departments
or agencies are identical or similar. The scope of Federal
activity is broad, however, despite this lack of an
ail-encompassing Federal law providing organizational continuity
in the control of solid wastes from mining activities.
The U.S. Mining Laws of 1872, as amended (30 U.S.C.§21-50),
apply to vacant and unappropriated public lands of the United
States and to national forests established on such lands. This
law is concerned with the disposition of all minerals that are
not otherwise specifically covered by statute. Very little of
202
-------
the statutory language in these laws provides for the Federal
Government either to control mining operations or to require the
restoration or treatment of land surfaces disturbed by
prospecting or mining.
The U.S. Department of Agriculture, however, issued
regulations (36 C.F.R. Parts 251, 252, 293) effective September
1, 1974, which require that exploration and mining activities on
National Forest Lands be conducted so as to minimize adverse
environmental impacts on the National Forest Systems. If it is
determined that a proposed operation may cause significant
disturbance to surface resources, a plan of operation, including
a description of the environmental and reclamation procedures,
must be submitted to the Department. Reclamation procedures
specifically include (1) control of erosion and landslides, (2)
control of water runoff, (3) reshaping and revegetating of
disturbed areas where reasonably practicable.
Regulations have also been issued for establishing
procedures to minimize adverse environmental impacts on the
surface of public lands from operations authorized under the U.S.
Mining Laws (enforced principally by the Bureau of Land
Management). These regulations are similar to those in 36 C.F.R.
Parts 251 and 252 covering National Forest Lands (described
/
earlier), but they only cover actions that result in "significant
disturbance" to the surface. Significant disturbance is defined
as "any disturbance to the environment other than casual use as
determined by the authorized officer."
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When Federal lands are involved, a plan of operation must be
approved by the authorized officer before beginning mining
operations that will significantly disturb surface resources.
This plan of operation must include a description of
environmental protection measures. In the interest of minimizing
environmental degradation during mining operations, the operator
must (1) comply with state and Federal standards covering air
quality, water quality, and disposal and treatment of solid
wastes; (2) harmonize mining operations with visual resources;
(3) minimize impact of mining operations on fisheries, wildlife,
and plant habitats; (4) avoid damage to cultural resources; (5)
properly construct and reclaim access roads; (6) reclaim surface
as soon as practicable. Reclamation is specifically defined to
include control of erosion and water runoff and control or
removal of toxic materials.
The Mineral Leasing Act of 1920 (30 U.S.C.§181 et. seq.)
provides for the disposition of minerals by means of leases and
permits issued by the Secretary of the Interior. The act covers
deposits of coal, phosphate, sodium, potassium, oil, oil shale,
native asphalt, solid and semisolid bitumen, bituminous rock, and
gas in public lands and in National Forests established on public
lands. The issuance of such leases and permits by the Secretary
is discretionary and may be denied if, in his judgment,
exploitation of the mineral deposit would impair other important
uses of the land. The act also gives the Secretary authority to
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impose requirements concerning mining operations and land
restoration following completion of these operations.
Regulations issued under this act (43 C.F.R. Group 3500)
require that a "valuable deposit of mineral" be discovered before
a preference-right lease for coal, phosphate, potassium, sodium,
or sulfur can be obtained. To obtain such a lease, an application
is submitted to an authorized officer of the Bureau of Land
Management who, with the assistance of the mining supervisor of
the Geological Survey, examines it technically and analyzes it
from the standpoint of the environment. The analysis includes an
evaluation of the impacts of the proposed operations on land uses
or resources and on lands adjacent to the affected area. Such
impacts are considered before issuing or denying a lease.
The Mineral Leasing Act of 1920 was amended by the Federal
Coal Leasing Amendments Act of 1976. This legislation
substantially changed Federal procedures for leasing coal rights.
The amendments include a requirement that no lease be issued
unless the lands containing the coal deposits are included in a
comprehensive land-use plan. Moreover, leases covering lands
under the surface management of any Federal agency other than the
Department of the Interior will be issued only with the consent
of that agency and subject to conditions stipulated by that
agency. However, the act lacks a general provision for minimizing
environmental impacts.
The Mineral Leasing Act for Acquired Lands (30 U.S.C.§351-359)
extends the coverage of the Mineral Leasing Act of 1920 to lands
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acquired by the United States (with certain exceptions). Again,
the Secretary of the Interior is authorized to issue leases and
permits for deposits of minerals such as coal, phosphate, sodium,
potassium, and sulfur. The conditions of the leasing provisions
of the 1920 act apply and the Secretary's authority is
discretionary. In addition, the head of the department, agency,
or instrumentality that has jurisdiction over lands containing
such mineral deposits may prescribe conditions that insure
adequate utilization of the lands for the primary purposes for
which they were acquired and are being administered. Limited
application of this act has been exercised.
The Materials Act of 1947 (30 U.S.C.§601, 602) authorizes
the Secretary of the Interior to dispose of certain minerals
found in public lands, including common varieties of sand, stone,
gravel, pumice, pumicite, cinders, and clay, provided that
disposition is not detrimental to public interest. The contracts
prescribed under this act bind purchasers to the observance of
good conservation practices. Such contracts, entered into for
the duration of operation, also provide for land restoration.
Similar authority is conferred upon the Secretary of Agriculture
with respect to lands administered for national forest purposes.
Executive discretion inherent in this act has resulted in
limited conservation or restoration practices.
The acts and regulations discussed thus far encompass the
Federal mineral leasing program. Two agencies of the Department
of the Interior, the Bureau of Land Management (BLM) and the
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Geological Survey (GS), have been delegated administrative and
management responsibilities for this program. Secretary's Order
No. 2948, dated October 6, 1972, divides the administrative
responsibility between the two agencies. The principal
objectives set forth in this order are to protect the environment
by assuring (1) that mineral exploration and production are
conducted with maximum protection for the environment, (2) that
precautions are taken to protect public health and safety, (3)
that operations are in full compliance with the spirit and
objectives of the National Environmental Policy Act of 1969,
other Federal environmental legislation, and supporting Executive
orders and regulations.
These agencies cooperate in formulating what is to be
incorporated in leases, permits, and licenses for the protection
of surface and nonmineral resources and for reclamation. The BLM
is responsible for ensuring compliance with environmental
protection and rehabilitation requirements inside the operating
area. Effectiveness has varied because official decisions are
sometimes inconsistent when applied to conditions in individual
cases.
The original thrust of the Federal mineral leasing program
was to provide an orderly system for locating, removing, and
utilizing valuable mineral deposits on federally owned and
controlled lands. Only recently has the Federal Government used
the broad enabling language of these laws to impose environmental
restrictions on mining operations. The passage of the National
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Environmental Policy Act of 1969 provided the principal impetus
for this move.
The National Environmental Policy Act of 1969 was the first
major attempt by Congress to establish a broad and comprehensive
environmental policy while simultaneously extending its control
over activities affecting the environment beyond lands owned or
controlled by the government. This act establishes a national
policy concerning the environment and declares that it is the
continuing policy and responsibility of the Federal Government to
use "all practicable means, consistent with other essential
considerations of national policy [and] to improve and
coordinate. . ." all Federal action to the end that certain
broad national objectives of environmental management may be
attained. By its terms, this act applies to every agency and
instrumentality of the Federal Government and, in effect, tells
each of the various Federal agencies and instrumentalities to add
a new criterion—effect on the environment—to those against
which they have traditionally tested their actions.
Section 102 of NEPA outlines several steps that Federal
agencies are required to take to assure attainment of the act's
broad environmental goals. The most significant action-forcing
device created by this section is the environmental impact
statement. Provisions of Section 102 (2) (c) state that every
agency of the Federal Government must "include in every
recommendation or report on proposals for legislation or other
major Federal actions significantly affecting the quality of the
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human environment, a detailed statement. . ."of the environmental
impact of such an action. Only a clear conflict with existing
agency statutory obligations can alter the agency's duty to
comply with NEPA's mandate.
The extent to which NEPA (particularly the requirement for
an environmental impact statement) affects the mining industry
depends initially on whether the proposed action is a "major
Federal action." Section 1500.5 of the guidelines promulgated
under the act indicates that "covered actions" include:
0 New and continuing Federal projects and program
activities directly undertaken by Federal agencies or
supported in any manner through Federal contracts,
grants, loans, or other financial assistance, or
involving a Federal lease, permit, license certificate,
or other entitlement for use.
0 The promulgation or amendment of regulations, rules,
procedures, and policies.
Exploration and mining operations under the Materials Act of
1947, as amended, and the Mineral Leasing Act of 1920, as amended,
specifically require such an environmental analysis.
Before mining operations can be initiated under the mineral
leasing laws, an environmental analysis or an environmental
impact statement generally must be prepared by the surface
management agency, the Bureau of Land Management, and the
Geological Survey. If the impact of the proposed operation is
expected to be small, an environmental analysis report (EAR) will
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suffice; if it is expected to be large, an environmental impact
statement must be prepared.
The Endangered Species Act of 1973 (PL 93-205; 87 Stat. 884),
supplants the Endangered Species Conservation Act of 1969 and
seeks to support worldwide conservation of flora and fauna. The
law encompasses all species of the animal and plant kingdoms and
is enforced by the Fish and Wildlife Service of the U.S.
Department of the Interior.
In practice, endangerment of the species must be involved.
The law establishes two categories of endangerment: (1) those
species in danger of extinction throughout all or a significant
portion of their range, i.e., Endangered Species; and (2) those
that are likely to become endangered within the foreseeable
future throughout all or a significant portion of their range,
i.e., Threatened Species. Enforcement includes a permit system
allowing for such things as enhancement, propagation, or
survival; zoological exhibition for educational purposes;
conservation management by states; or special purposes consistent
with the act, which largely aims at preventing harm to endangered
or threatened species.
Issuing or withholding a Fish and Wildlife Service permit
(or preventing another Federal agency from taking such action
under its authority) is based on an assessment of the potential
harm to the ecosystem caused by the infringement. Mining activity
could conceivably constitute an infringement that might be
prevented or limited. Placement of mineral resource solid wastes
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that might not violate regulations governing air or water
pollution could destroy a habitat or species. Should such
infringing harm exist, the act provides for steps to be taken to
prevent or limit the action.
The National Environmental Policy Act of 1969 and the
Federal agency authorized to enforce or carry out certain actions
within its jurisdiction are mechanisms for preventing an action.
For example, the Corps of Engineers may refuse to issue a permit
to dredge for sand and gravel if the Fish and Wildlife Service
objects on grounds that endangered or threatened aquatic life may
be harmed. Likewise, the Bureau of Land Management or the
Geological Survey may withhold mineral leasing permits for
"public domain lands" if they determine that an endangered or
threatened species may be harmed. These agencies are the focus
of the mining leasing programs of the Federal Government and are
responsible for maintaining the objectives and spirit of NEPA in
administering these programs. The situation would be the same if
mining operations were proposed on National Forest System lands
under the jurisdiction of the U.S. Forest Service (FS) or
National Park Service under its regulations. Although it has the
potential of affecting the disposal of solid wastes, as a general
rule this act has not been applied specifically to solid waste
problems.
The National Historic Preservation Act of 1966 (PL 89-655,
80 Stat. 915), formerly the Antiquities Act of 1906 (34 Stat.
1225), can impact proposed mining endeavors. This act is
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intended to preserve cultural resources such as archaeological
and paleontological sites, and historical buildings and sites.
The act is normally enforced in two ways: (1) if a proposed
mining site is known to have cultural resources, it is usually
explored, and artifacts (e.g., arrowheads, pottery) or specimen
(e.g., fossils) are collected, catalogued, and delivered to an
official repository (such as a nearby university); (2) if such
items are discovered after mining activities have already begun,
the same procedure is followed. Occasionally, a determination
may be made to give a site National Register status. When this
occurs/ mining may be precluded on all or part of the area, or
special provisions may be made for preserving the site during
mining activities. Historical buildings and sites (e.g.,
battlefields) also may be cited to the National Register, and
mining may be precluded or controlled. In actual practice,
seldom have the proposed mining or other activity been completely
precluded. The usual case recovers any artifacts unearthed or
isolates historic resources from the permitted mining area.
Section 13 of the River and Harbor Act (30 Stat. 1152; 33
USC 407) approved March 3, 1899, provides for controlling
discharge of refuse into navigable waters. A permit to discharge
can be issued if it is determined that such discharge would not
be injurious to anchorage and navigation. This section, known as
the Refuse Act, was originally enforced by the Army Corps of
Engineers. This authority has since been superseded by the
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permit authority provided by the U.S. Environmental Protection
Agency under sections 402 and 405 of the Federal Water Pollution
Control Act.
"Refuse" was broadly defined under permitting authority of
the Army Corps of Engineers and affected mining with regard to
oil and sediment discharges. "Black water" from coal washing and
sand and gravel extraction were commonly controlled under this
section. Because of a duplication in the authority to control
these discharges as well as dredge or fill material between
Section 404 of the Federal Water Pollution Control Act and
Section 13 of the Refuse Act, the latter has remained unused in
recent years. Section 404 is administered by the Army Corps of
Engineers, and waste disposal sites are selected in accordance
with guidelines developed by the U.S. EPA.
The laws and regulations discussed thus far do not treat the
disposal of solid wastes from mining operations as a separate and
distinct problem. Control of solid wastes is considered only an
incidental part of an overall environmental program. The thrust
of NEPA is the protection of the environment regardless of the
kind of pollutant. Regulations issued under the Federal mineral
leasing laws are slightly more specific only because they relate
to all pollutants discharged from mining operations. In both
cases, only lands owned or controlled by the Federal Government
are affected.
The original purpose of Federal air and water pollution
control programs (unlike that of the Federal mineral leasing
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program) was .to establish nationwide standards for pollutants
that had been shown to have an adverse effect on public health
and welfare. The discharge of pollutants from mining operations
is affected by these laws only insofar as such discharges affect
the overall quality of the air and water. The Federal Water
Pollution Control Act, the Clean Air Act, and the Safe Drinking
Water Act are the principal air and water pollution control laws
that affect mining operations.
Congress passed the Federal Water Pollution Control Act
Amendments of 1972 (Public Law 92-500) to create an orderly and
uniform program "to restore and maintain the chemical, physical,
and biological integrity of the Nation's waters" by eliminating
pollutant discharges into navigable water. The implementation of
this policy affects the discharge of solid wastes from mines in
several ways.
Section 208(b)(1) of the act requires that a plan be
prepared according to areawide waste treatment management
practices. The plan must, include:
"(G) a process to (i) identify, if appropriate, mine-related
sources of pollution including new, current, and abandoned
surface and underground mine runoff, and (ii) set forth
procedures and methods (including land use requirements) to
control to the extent feasible such sources[.]"
Waste treatment management plans and practices must provide for
the application of the best practicable waste treatment technology
and the control or treatment of waste from all point and nonpoint
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sources. A National Pollutant Discharge Elimination System
(NPDES) permit (under section 402 of the act) will not be issued
if any point source is not so managed.
Mine operators may also be subject to the provisions of
section 311 of the act if the discharges from the mining
operation contain substances classified as hazardous. This could
have particular impact on tailings ponds, which sometimes .contain
toxic constituents.
The major feature of the Federal Water Pollution Control Act
Amendments of 1972 that affects mining is the national permit
system for the control of discharges into navigable waters. The
National Pollutant Discharge Elimination System requires that the
owner or operator of a point source of pollution obtain a Federal
permit before legally discharging pollutants into navigable
waters. The EPA has taken the view that any concentrated,
pollutant-bearing flow that is caused by man is a point source,
regardless of whether the conveyance is man-made or the result of
natural water flow from the point at which the operator's
activities caused the water to collect and become contaminated.
It is generally presumed that a mining operation will have at
least one point source of pollutants. Section 404 of the act
requires a different permit (issued by the Corps of Engineers)
for any discharge of dredged or fill material into navigable
waters at specified disposal sites.
The Federal Water Pollution Control Act was amended in 1977
by the Clean Water Act (Public Law 95-217). The impact of these
changes upon the mining industry is still uncertain.
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The Clean Air Act (42 U.S.C.§1857, et seq.) establishes
ambient air standards for particulate matter dispersed into the
air. Most atmospheric emissions from mining operations are in
the form of dust. Regulations issued under the Clean Air Act (40
C.F.R. Part 51) specify the requirements for State Implementation
Plans (SIP's). These regulations recognize the adverse effects
of fugitive dust on air quality and set forth suggested
precautions calculated to provide control of these emissions by
reasonably available technology. Such precautions include the
application of asphalt, oil, water, or suitable chemicals on
roads, materials, stockpiles, and other surfaces which can give
rise to airborne dust. Regulations also set forth suggested
visible emission limitations, which may also affect the discharge
of particulate matter from mining operations.
Specifically, with regard to fugitive dust from mining and
beneficiating areas, however, in its Prevention of Significant
Air Quality Deterioration Requirements for State Implementation
Plans (Federal Register, June 19, 1978), the EPA temporarily
excluded fugitive dust from any air quality impact assessment,
pending further development in modeling techniques for fugitive
dust.
The Safe Drinking Water Act (P.L. 93-523) establishes
guidelines for the protection of underground sources of drinking
water. This act could have a profound effect on mining operations
that contaminate wells or other sources of drinking water with
wastes. If such operations contribute significantly to the
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failure of a public water system's compliance with the national
primary drinking water regulations or otherwise adversely affect
human health, the mine operator may be required to prevent
percolation or seepage of contaminants from tailings ponds and
other operations into the surrounding sources of drinking water.
Primary enforcement authority under this act lies with the
states, subject to somewhat stringent requirements and limitations
established by the U.S. EPA.
The Solid Waste Disposal and Resource Recovery Acts of 1965
and 1970 constituted the first major Federal effort in the solid
waste field. These acts were not regulatory in nature, however,
and the role of the U.S. EPA was limited primarily to providing
technical and financial assistance to state and local agencies.
Recognizing the inadequacy of these acts and the need for
comprehensive solid waste control programs, Congress passed the
Resource Conservation and Recovery Act (RCRA), which was signed
into law on October 21, 1976. This act establishes a national
regulatory framework to govern solid waste disposal and gives the
EPA new authority to establish standards and regulations to
complement its traditional financial and technical assistance
functions.
Generally, RCRA prohibits future open dumping and requires
that present open dumps be upgraded to sanitary landfills. It
also regulates treatment, storage, transportation, and disposal
of hazardous wastes and provides guidelines for collection,
transportation, separation, recovery, and disposal of solid
wastes.
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Subtitle D of RCRA provides for the regulation of solid
waste disposal. In determining the extent to which this
provision affects the mining industry, it must be established
whether the materials produced by the mining process are
considered solid wastes.
The act defines solid wastes as "any garbage, refuse,
sludge. . . and other discarded material, including solid. . .
material resulting from industrial, commercial, mining, and
agricultural operations. . ." Most mining wastes clearly fall
within this broad enabling definition. Although there is some
support for the belief that overburden piles and wastewater
impoundments were not intended to be included as solid wastes,
the overriding concern of Congress in adopting RCRA was to
eliminate or control any emissions that might adversely affect
the health and environment, and any evaluation of what is included
as solid wastes must be based on this concern.
The next question that arises is whether the piles of slag,
dumps of mine waste rock, tailings impoundments, and the like
created during mining operations are open dumps within the
meaning of the act. An open dump is defined as a disposal site
that is not a sanitary landfill and a sanitary landfill is defined
as a disposal site where no reasonable probability of adverse
effects on health or the environment exists. Detailed definitions
of these terms have not yet been offered. Section 8002(f) of the
act, however, specifically requires the EPA to make a study to
determine the adverse environmental effects of solid wastes from
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active and abandoned surface and underground mines. The study,
of which this section is a part, will include an analysis of (1)
the source and yearly volume of discarded material generated by
mining, (2) present disposal practices, (3) potential dangers to
human health and the environment from surface runoff of leachate
and air pollution by dust, (4) alternatives to current disposal
methods, (5) the cost of those alternatives in terms of the
impact on the mine product costs, (6) potential for use of
discarded material as a secondary source of the mine product.
Some wastes generated by mining operations may also be
classified as hazardous wastes. The act defines hazardous wastes
as solid wastes that because of their quantity, concentration, or
physical, chemical, or infectious characteristics may "cause, or
significantly contribute to, an increase in mortality or in
serious irreversible or incapacitating reversible illness; or
pose a substantial present or potential hazard to human health
when improperly handled." Whether or not particular wastes
generated by mining activities are considered hazardous will
depend on criteria, guidelines, and regulations promulgated by
the EPA.
The Surface Mining Control and Reclamation Act of 1977 is
the most recent attempt by Congress to control surface coal
mining and reclamation operations. Recognizing the importance of
allowing each state to develop its own surface mining regulations,
Congress placed the primary responsibility for implementing the
provisions of the act with the states. Nevertheless, the newly
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created Office of Surface Mine Reclamation and Enforcement
(Department of Interior) is developing guidelines for use by the
states and will review state programs prior to approval.
The act establishes a two-phase program for enforcing
performance standards governing surface coal mine operations.
The regulatory program is initially carried out by the Federal
Government (during the interval between enactment and adoption of
a permanent state or Federal program). The initial regulatory
program ends in a particular state and the permanent program
begins either when the state's regulatory program has been
approved by the Secretary of the Interior or when the Secretary
implements a full Federal program in that state because of the
state's failure to submit an acceptable program.
The operator of a surface coal mine must meet eight
performance standard requirements during the initial program.
These include designing, maintaining, and removing all existing
and new waste piles used as dams or embankments and minimizing
disturbances of the hydrological balance. The initial regulatory
program also establishes special performance standards for the
surface effects of underground coal mining, which broadens the
impact of this act to affect substantially all types of coal
mining.
During the permanent program, the regulatory authority
issues permits requiring the operator to comply with all the
environmental performance standards of the act. These standards
include (1) stabilizing all areas to control erosion, and air and
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water pollution, (2) designing and constructing permanent water
impoundments to assure that the quality and quantity of water
will not be diminished to adjacent owners, (3) stabilizing all
waste piles, (4) burying or otherwise treating all combustible
materials and acid-forming or toxic materials in a manner that
prevents contamination of waters and sustained combustion. The
methods of enforcement may include cessation orders for failure
to comply with a notice of violation, suspension, or revocation
of permits.
The act also creates an abandoned mine reclamation fund to
be used for reclamation of land and water affected by coal mining,
for filling voids and sealing tunnels, for acquisition of
unreclaimed land, and for research and demonstration projects on
reclamation of abandoned lands.
Several other Federal agencies and instrumentalities may
have an indirect impact on the handling and disposal of solid
wastes. As has been implied in descriptions of the various laws,
however, enforcement is subject to executive discretion and not
Congressional mandate. Consequently, enforcement of solid waste
concerns has been piecemeal. The Rivers and Harbors Act of 1899
requires an individual to obtain authorization from the Army
Corps of Engineers for all structures and works in navigable
water. Section 9 of the act directly governs the construction
and structural stability of dams and dikes. This provision may
be applied to piles and dams used in creating tailings or
sedimentation ponds. As noted earlier, the Corps is also
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directed to establish and apply criteria for the issuance of
permits under Section 404 of the Federal Water Pollution Control
Act for the discharge of dredged or fill material into navigable
waters at specified disposal sites. Section 515 of the Surface
Mine Control and the Reclamation Act of 1977 require that the
Corps of Engineers concur in any regulations pertaining to coal
mine waste piles and dams promulgated under the act.
The Mine Safety and Health Administration (MSHA), formerly
MESA, exercises some indirect control over the disposal of
mineral resource solid wastes. Section 30 C.F.R. Part 77
establishes certain requirements pertaining to the construction
of dams and dikes used for water, sediment, and slurry
impoundments at coal mines. This authority somewhat overlaps the
jurisdiction of the Corps of Engineers. Coal refuse piles, which
are a major source of pollution runoff and leaching, are also
subject to control under these safety and health requirements.
All active refuse piles and impounding structures must be
certified each year by a registered engineer who assures the
stability of the structure. These structures may be abandoned
according to an approved plan; if abandoned, no further stability
certifications are required. This agency does not promulgate
guidelines or regulations, it merely provides advice to industry.
The absence of formal regulations restricts its effectiveness.
The disposal of solid wastes containing radioactive
material is regulated under the Atomic Energy Act of 1954, as
amended, Title II of the Energy Reorganization Act of 1974, and
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regulations, orders, and licenses thereunder. The agency primarily
responsible for administering regulations under these acts is the
Nuclear Regulatory Commission (NRC). The NRC has established
strict limitations on the concentration of radioactive material
permitted in effluents released into unrestricted areas. These
limitations extend to concentrations of radioactive materials
released to both air and water. With regard to mining operations,
however, NRC regulations apply only to radioactive tailings. The
control of radioactive wastes generated by mining activities has
been left to state authority in states that have agreements with
NRC (e.g., Colorado, New Mexico), but controlled directly by NRC
in so-called nonagreement states (e.g., Wyoming).
The proposed RCRA regulations (Federal Register, Dec. 18,
1978), cover only mine wastes generated by the uranium mining
industry. The Uranium Mill Tailings Radiation Control Act of
1978 (Federal Register, Nov. 8, 1978), authorizes EPA to set
health and environmental standards and the NRC to regulate
uranium tailings at both active and inactive sites.
State Laws and Regulations
State laws and regulations directly affecting the disposal
of solid wastes from mining operations can generally be divided
into two major categories: laws affecting solid wastes via laws
governing air and water pollution control, and laws governing
reclamation of solid wastes after mining operations cease. Both
vary greatly from state to state with regard to stringency of
penalties, amount of detail, and flexibility of administration.
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Generally, air and water quality laws are administered by one
agency and reclamation law by another. Appendix B lists the
state laws governing pollution abatement and indicates
legislative activity in this area.
Solid waste disposal is indirectly, and to a limited extent,
affected by state mining laws. Generally, one or more permits or
licenses similar to those required under the Federal mineral
leasing laws must be obtained from state agencies before mining
operations may be initiated. The extent to which these laws may
be used to provide control over solid waste disposal varies.
Some states specifically set forth conditions under which mining
operations must be conducted, whereas other states give the
issuing officer authority to include terms and conditions in the
permit or license he deems necessary to protect the public
interest.
Most air regulations adopted under approved State
Implementation Plans include a fugitive dust regulation, a
visible emission regulation, or both. The regulations are
usually similar to the guidelines developed by the U.S. EPA and
do not apply specifically to mining operations. Some states,
however, have adopted fugitive dust regulations to include certain
mining activities. Colorado, for example, specifies some
abatement and prevention measures for open mining activities and
requires a new permit before starting new mining operations.
Appendix C presents a summary of the state fugitive dust
regulations. Some states specifically regulate activities such
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as coal handling; sand, gravel, and stone crushing operations;
and general quarrying and mining.
Typical state water pollution control laws declare it
unlawful for any person to cause pollution of any surface waters
or to place, or cause to be placed, any wastes in a location
where they are likely to cause pollution of any waters within the
state. It is also generally declared unlawful for any person to
discharge waste products into these waters without first securing
an NPDES permit from the state water pollution control agency or
the EPA specifying discharge limits. These permit systems may be
operated solely under the authority of the state when EPA has
approved the state's plan and program. If approval is not given
or is withdrawn, EPA operates the NPDES program directly. The
Federal Water Pollution Control Act Amendments of 1972 encourage
states to take over administration of the NPDES program with
regard to discharges located within the state; permit authority
is fully transferrable to state water quality agencies upon
approval of EPA. Existing state permit programs do not preempt
the requirements of the NPDES program, however, unless approved
by the EPA.
Groundwater regulations have also been promulgated in some
states, particularly in the West, where discharges onto or below
the surface of the ground have endangered domestic and
agricultural water supplies. Although these regulations may not
be specific to any particular industry, they have some impact on
mining operations and the control of solid waste because of a
scarcity of enforcement resources.
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With Federal support, most states have developed comprehensive
programs to deal with the ever-growing problem of solid waste
disposal. Such programs are primarily concerned with the
collection and disposal of municipal and some industrial refuse.
Many laws were promulgated in response to the encouragement and
technical assistance of the Federal Government through the Solid
Waste Disposal Acts of 1965 and 1970.
As part of their solid waste programs, some states have also
assumed regulatory authority over the disposal of solid wastes
containing radioactive materials. The NRC has established
guidelines whereby states may assume the administrative and
enforcement obligations for sources of radioactive materials
within the state. There are 25 of these so-called "agreement
states." The procedures and regulations promulgated by the
states are usually similar to those issued by the NRC.
The environmental impact analysis procedure is more severe,
however, in the nonagreement states. Few states have extended
their authority over potentially hazardous mining operations.
Texas, for example, is developing regulations for the control of
radioactive materials in tails and mining wastes. The regulations
will prohibit any industry from exposing the public to
radioactive hazards. New Mexico has taken a similar regulatory
approach to cover wastes generated by mining that are not
controlled by another agency.
Many state laws regarding reclamation of mined area are
relatively new and have not yet reaped any noticeable benefits.
226
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Reclamation of mined land is not a new concept. Arizona, Oregon,
and Ohio have had statutory provisions for some form of
reclamation for more than 10 years. The surface mining laws in
nine states have required some reclamation for more than 35
years. Generally, these reclamation laws applied only to coal
mining operations. In West Virginia, Indiana, and Illinois,
however, the laws cover all minerals. Effectiveness of these
laws has varied, depending upon enforcement efforts. Their
impact on solid waste disposal has not been consistent.
Most states now have some type of a law covering reclamation
after mining. All kinds of minerals are covered in approximately
half of these regulations. Coal mining operations are
specifically covered in 37 states, and the mining of metals is
covered in 32. Most state regulations, however, are not specific
about the degree of reclamation required, and inspection to
ensure compliance is limited. Consequently, reclamation goals
are often not achieved.
Reclamation laws usually require the mine operator to
obtain a permit and submit a reclamation plan for approval. The
reclamation plan must contain, for example, complete drainage
plans and proposed methods for disposing of wastes, including any
restoration measures to be taken after operations have ceased and
other such information the agency may require.
New Federal requirements are often generated to supersede
those of the states because of a national concern regarding the
adequacy of state and local regulatory programs to protect the
227
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public. This concern led to the enactment of legislation that
mandated Federal oversight of most mining industry activities,
and the creation of distinct state and Federal programs that has
led to administrative and regulatory duplication in some states,
particularly concerning air and water pollution and reclamation.
Duplication problems occur primarily in four areas. First,
duplication arises when more than one agency is responsible for
reviewing the same plan or application. Second, duplication
results from more than one agency requiring a permit for the same
facility or for a single facet of an operation. A third form of
duplication arises when compliance is required with the independent
regulations of more than one agency. The fourth duplication
problem is the pyramiding effect of permits when the meeting of
one agency's regulation depends upon the compliance with the
regulations of another agency with overlapping jurisdiction.
It is difficult to compare state regulations because the
actual number of approvals required depends on the design
characteristics (e.g., type and production capacity), location,
and scheduling of a specific facility. The effluent sources of a
mine, for example, may require separate permits for drainage
points, refuse pile discharges, and sediment basins. It is
conceivable that approval of all water effluent or air emission
sources at a single facility could be obtained administratively
by a single permitting process; however, unless the state has
NPDES authority under the 1972 Federal Water Pollution Control
Act Amendments, the appropriate state water quality control
228
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agency may issue its own permit, which may be in addition to the
NPDES permit issued by the EPA. This discontinuity in authority
would hinder administrative consolidation of the permitting
process.
Recently, some states have attempted to reduce the number of
distinct permits required for a particular mine by streamlining
internal agency policies regarding multiple permit applications.
In Pennsylvania, for example, most functions regarding permits
are administered by the Department of Environmental Resources
(DER). The DER has been granted complete authority over surface
and underground mining operations, as well as preparation plants.
As an administrative policy, DER has decided to issue all permits
applicable to a given mine. Although the permit application must
still be approved by several different departments (such as the
Bureau of Air Quality and the Bureau of Water Quality Management),
this system relieves the mine operator of the responsibility of
obtaining separate permits from a number of different agencies.
In theory, this enables DER to foresee, and therefore fully
address, all potential environmental problems in a comprehensive
and timely fashion.
Most states have divided the responsibility of overseeing
the mining industry. Pennsylvania and Kentucky are typical
examples (Figures 23 and 24). In Kentucky, most permit authority
involving environmental controls is vested in the Department of
Natural Resources and Environmental Protection (DNREP). The
"divisionalized" permit process of DNREP, however, is one in
229
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COMPLIANCE K/LOWl
ZONII* AUNCf*
SURFACE KIM OPERATOR'S
LICENSE ISM-0TI(M)
PIWIT BKW-DO
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PERMIT M.P-OCI
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EMOKC-OCK
IIFUSE 01VOSAI SHI
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«AT(B OISCHAIU PEWIT
SECTION 10
ANC.'OB SECTION 40A
(oerotl DISPOSAL)
PEWITS FOR W«I&AI1E
•ATERS COC
,»l»l(« IT r.s)
dATER ILinCATIO*
IPPkOvAL IHTERSTATE
PUIt BASIo .INllSSIOli^
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HP VOEB
BCVKTIQ
XOUIRCD Kf'EOUEHTlT . USfO OH SITE LOCATION.
PL» APPWyAl I«IST COHnT KITH LOCAL 111 DUAL, ITT
STAKOAROS APPtlCAKE OW.T KITHIII A MV UIIAII AIMS.
AmovAis O»T RtauiRtO 'ot PIAICTS HITNII
Of SUSOUtNAMU AAB DUAHMt IKCR IASIK COMMISSICMS
MR • DEPAITMUT Of i«I llOHtEnTAi BtSOufiCES
ISM • luMAu or SuWAil DIM lEClAHATIM
IF . IUREAU Or rORESTIT
llO< • BbBEAU Or «ATER QUAI.ITT VHAMKUT
BIP - BUIUU OF LUC P«OT[CT10«
EUONC • BUREAU OF Alt OuAlITT AND (CISl COHTROL
OOXS - OFFICE nr MEP HIIIE SArET»
EPA - («>!ROW
-------
C AND 0 PERMITS FOR
SEWAGE TREATMENT
PLANT DWO-DNREP
(APPROVAL BY LOCAL
GOVERNMENT)
PLUMBING FACILITIES
APPROVAL DP-DNREP
SOLID (ORY MINE) UASTE
DISPOSAL PERMIT
DSW-DNREP
AIR CONTAMINANTS
PERMIT DAO-DNREP
COMPLIANCE W/LOCAL
ZONING AGENCY*
RECLAMATION PLAR
WATER WITHDRAWAL
PERMIT DWR DNREP
PERMIT TO CONSTRUCT
DWR-DNREP
DISCHARGE PERMIT
UNDERGROUND MINE
LICENSE DMM
SECTION 10 (OBSTRUCTION)
AND/OR SECTION 404
(DREDGE DISPOSAL)
(REVIEW BY FWS)
WATER DISCHARGE PERMIT
(NPDES) EPA
MINE OPENING PERMITS
DM*
MINING PLAN APPROVAL
HSHA
CERTIFICATE OF
COMPLIANCE KY DOL
C AND 0 PERMITS FOR
POTABLE WATER
FACILITIES
DSE-DNREP*
COAL HAULAGE PERMIT
KY DOT
MONITORING AND
ENFORCEMENT
A. EPA
B. HSHA
C. OR 1
D. OAO i DNREP
E. OWO \
SECTION 10 (OBSTRUCTION
AND/OR SECTION 404
(DREDGE DISPOSAL)
PERMITS FOR NAVIGABLE
HATERS COE*
(REVIEW BY FWS)
WATER DISCHARGE PERMIT
(NPDES) EPA
REFUSE DISPOSAL SITE
APPROVAL MSHA
CERTIFICATE OF
COMPLIANCE KY DOL
COAL HAULAGE PERMIT
KY DOT
ABBREVIATIONS
DNREP - DEPARTMENT FOR NATURAL RESOURCES AND
ENFORCEMENT PROTECTION
OR - DIVISION OF RECLAMATION
DHQ - DIVISION OF WATER QUALITY
DWR - DIVISION OF HATER RESOURCES
DSW - DIVISION OF SOLID WASTE
DAQ - DIVISION OF AIR QUALITY
DP - DIVISION OF PLUMBING
DSE - DIVISION OF SANITARY ENGINEERING
OHM - DEPARTMENT OF MINF.S AND MINERALS
KY DOT - KENTUCKY DEPARTMENT OF TRANSPORTATION
DY DOL - KENTUCKY DEPARTMENT OF LABOR
EPA - ENVIRONMENTAL PROTECTION AGENCY
HSHA - MINE SAFETY AND HEALTH
ADMINISTRATION
COE - ARMY CORPS OF ENGINEERS (FEDERAL)
FWS - FISH AND WILDLIFE SERVICE (FEDERAL)
NPDES - NATIONAL POLLUTION DISCHARGE ELIMINATION
SYSTEM
C A«D 0 - CONSTRUCTION AND OPERATION
MONITORING AND
ENFORCEMENT
A. EPA
B. COE*
C. HSHA
0. OWQ1
E. DWR I
F. DSW > DNREP
' REQUIRED INFREQUENTLY - BASED ON SITE LOCATION.
• REGULATIONS FOR ENFORCEMENT STILL PENDING.
i KRS SECTION 109 PROVIDES FOR LOCAL COLLECTION OR DISPOSAL
DISTRICTS - EXIST MAINLY III URBAN AREAS.
I REQUIRES PRIOR CERTIFICATION OF SEDIMENT'AND EROSION
CONTROL PLAN AND POST-CERTIFICATION OF STRUCTURES BY
REGISTERED ENGINEER.
Figure 24. In Kentucky the responsibility of overseeing
the coal industry is divided as illustrated.
Source: Rosenberg, J.E., et. al. Regulation of the
coal mining and preparation industry.
231
-------
which each division has significant autonomy. Individual permits
are generally issued for specific activities without awaiting
concurrent approval of permits outstanding in other divisions.
Local Laws and Regulations
The disposal of solid wastes from mining operations may also
be affected by local zoning ordinances. Most states have laws
that authorize counties to regulate the use of land outside
incorporated areas and control the location of industry. Some
states also permit villages, cities, and towns to enact zoning
ordinances governing the use of lands within their boundaries.
Mining operations could be regulated through such zoning
ordinances, unless specifically exempted by law or judicial
interpretation.
The method of operating is one of the principal questions
counties and municipalities concern themselves with when enacting
zoning ordinances to regulate or restrict mining operations.
Operating methods generally fall into two categories: operating
standards (i.e., measures to reduce dust and dirt and maintain
the appearance of the mining site) and reclamation standards
(i.e., operating drainage and preservation of topsoil).
Local control of mining by counties and municipalities has
been and is a subject of concern in some areas of the United
States. In highly populated metropolitan areas, there is
potential for conflict between using land for the extraction of
mineral deposits such as sand and gravel and using land to meet
ever-increasing housing, recreational, and educational needs.
232
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Such conflict can place pressure on zoning authorities to either
refuse or allow mining at a particular location. It also puts
pressure on operators to provide effective pollution control in
those areas where mining is permitted. Zoning seldom prohibits
mining entirely.
Although most state governments administer their pollution
control programs, some states have chosen to delegate the
enforcement of these programs to local governments. In Florida,
for example, approval to mine is required on the local level from
the County Planning and Zoning Commissions, County Departments of
Pollution Control, County Engineering Departments, and Boards of
County Commissioners. These agencies have not significantly
prevented or delayed mining activities in Florida. Similarly,
the State of California has delegated the regulatory powers of
its various pollution control statutes to local jurisdictions.
Because of this delegated authority, regulations governing mining
operations may vary from county to county, and district to
district.
With regard to solid wastes in particular, most state laws
permit local governments to retain jurisdiction over the
development and implementation of collection and disposal programs,
The potential also exists for local control of solid waste
disposal through common law action, but is not generally invoked.
For example, many states permit common law action against private
landowners for maintaining a nuisance. Remedies include recovery
of damages and injunction against continuance or commission of
233
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the nuisance. As laws and regulations become firmly established
and enforced, however, such nuisance cases will be rare.
In the area of water quality control, as in other areas of
nuisance laws, the law produces widely disparate and contradictory
judgments and results. One reason this common law remedy has not
proven adequate in abating pollution is that most mine land is
titled to private nonmining owners, and the courts have been
historically unwilling to impose liability on private landowners
other than miners. Furthermore, the acreage is so vast and
sources of pollution so numerous, that lawsuits involving
individual parcels of land would present monumental proof problems
and, even if successful, would have a seemingly insignificant
impact on the total pollution problem.
This section has described the relationship between the
mining industry and Federal, state, and local regulations
governing mining operations, with a particular emphasis on control
and disposal of solid wastes. The regulatory framework within
which most mines must operate consists of a rather imposing and
sometimes cumbersome array of guidelines, criteria, and
regulations characterized by multiple permit requirements and
jurisdictional overlapping between and within governmental levels.
Environmental regulation, however, tends to be related to air and
water quality rather than solid wastes. The growing Federal
involvement in the regulation of mining operations, especially in
the area of pollution control, has the potential for reducing
234
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these differences through administrative consolidation, thus
providing a more effective system for protecting the environment.
Legislation with the potential of controlling solid waste
from mining operations varies, depending on whether the mine is
on public or private land and on the regulations promulgated by
each state and local authority. On public land, the granting of
mining rights under the Federal mineral leasing program is
generally preceded by preparation of an environmental impact
statement. Examination of necessary pollution control measures
should be part of the environmental impact of evaluation. The
decision to grant or deny leases could be made after a thorough
evaluation of a proposed mining plant, stipulating that
environmental damage or change be minimized as a condition of the
lease. On private land, solid waste disposal could be affected
by state and local regulatory agencies with authority to control
mining and beneficiating operations. Effectiveness in controlling
solid wastes in each case would depend upon adequate guidelines
and enforcement efforts. Federal air and water quality guidelines
have added new wastes (sludges) to the inventory of solid wastes
from private mining operations and also have indirectly affected
control of pollutants from solid wastes. The passage of RCRA
and the Federal Surface Mining Act may cause Federal law to have
a significant direct impact on all phases of mining operations.
The Surface Mining Control and Reclamation Act provides the
states with broad powers to develop and enforce regulations on
surface coal mining and reclamation operations. This act not
235
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only gives the states the flexibility to develop regulations that
meet the particular needs of that state, it also provides a
mechanism for reclaiming land and water affected by coal mining.
Moreover, it covers both surface mining operations and surface
changes caused by underground mining operations. Certain
reclamation measures can also indirectly control adverse impacts
from solid wastes. The Surface Mining Control and Reclamation
Act applies only to coal mining operations, however, leaving the
surface mining of other minerals largely within the control of
the states.
The Resource Conservation and Recovery Act mandates
regulation of the discharge and disposal of all types of solid
wastes. It also provides for a detailed and comprehensive study
of the adverse environmental effects of solid wastes from active
and abandoned surface and underground mines. The act provides
authority for regulating the prevention or mitigation of such
adverse effects as may exist, as determined by the EPA.
236
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SECTION 7
IDENTIFICATION OF POTENTIAL PROBLEM AREAS ASSOCIATED
WITH MINERAL RESOURCE WASTES
The previous sections of this report have presented the
overall status of the generation and disposal of mineral resource
wastes and their impacts on the environment. Quantities and
characteristics of wastes from major mining industries, applicable
environmental control technologies, and pertinent regulations
governing disposal and control have been discussed. This section
presents potential problem areas associated with these mineral
resource wastes according to various criteria, including those
currently established in the proposed RCRA regulations. The
potential problem areas are discussed under the following headings
0 Acid-Forming Mineral Resource Wastes
0 Mineral Resource Wastes Containing Radioactive
Materials
0 Other Potentially Toxic Mineral Resource Wastes
0 Combining of Mineral Resource Wastes With Other
Industrial Wastes
0 Airborne Fugitive Emissions Generated From Mineral
Resource Wastes
Collectively, these problem areas encompass a wide range of
mineral industries; for the most part they do not represent a
problem mineral. For example, the environmental problems
associated with acid-forming mineral resource wastes result
237
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primarily from the presence of pyrites in the orebody host rock.
Pyritic host rock occurs sporadically throughout the country in
combination with coal, copper, lead, zinc, iron, and many other
ores. Also, many important environmental impact factors are not
industry-specific, such as the topography, geology, and climate
in the vicinity of a facility. For these reasons, the main
environmental problems associated with mineral resource wastes
are assessed according to concept rather than specific industry.
Acid-Forming Mineral Resource Wastes
Acid water and acid slurries from acid-producing solids
constitute a major source of groundwater and surface water
contamination. Mine water and tailings-pond water with a pH of 5
or less can be expected to have deleterious effects on surface
water and groundwater in most hydrogeologic environments. This
is believed to be a significant source of contamination.
The impact of acid water, which is almost always combined
with solid waste in the form of a low-viscosity slurry, is
compounded by the fact that low-pH^waste slurries increase the
solubility'of heavy metals. The acid water not only increases
, :. .P: t:. ..' " .. >••• • •:.•:.-.
the., .rate-of the dissolution of soluble compounds. that, are,
ubiquitous in beneficiation processes, it also displaces heavy
metal cations that may be absorbed on the particulate matter in
the solid waste. The acid contributes protons to ion exchange
sites, and the heavy metal cations replace the protons in
solution. This not only results in acid water, but in acid water
238
-------
containing heavy metal cations, usually in excess of drinking
water standards and effluent guidelines established by the
National Pollutant Discharge Elimination System (NPDES), which
are now enforced under the Water Pollution Control Act Amendments
of 1977 and 1972. In order to meet NPDES guidelines, low-pH mine
and beneficiation waste slurries must be treated by the best
established practicable control technology* which has been
identified to be lime neutralization and clarification for most
of the industries producing such waste slurries.
Although applying the best practicable control technology
for neutralization of low-pH mine and benefication wastewaters
can satisfy the NPDES effluent guidelines for point-source
discharges, it does not alleviate the problem of groundwater and
surface water contamination due to seepage from tailings ponds or
other mineral resource disposal facilities.
Such seepage is documented in the literature, even though an
extensive survey of the Nation's mineral waste disposal facilities
2
.made.
The Surface Impoundment Assess.me.nt, a requirement of the Safe
Drinking Water Act of 1974, has been initiated but the results
will not be available until mid-1980. That study will provide
degree of contamination resulting from acid
This potentially contaminating acid water is produced largely
by the oxidation of the mineral pyrite. In the presence of water
and air, pyrite is transformed to soluble iron and sulfuric acid and
239
-------
subsequently to precipitated solids according to the following
reactions:
2FeS2 + 2H20 + 702 ->• 2FeS04 + 2H2S04
4FeSO,. + 2H-SO, +
4 24
Fe~ (SO.) - + 6H00 •*
243 2
7Fe-(SO.), + FeS- + 8H.O -»• ISFeSO. + 8H_SO.
^43 2 2 4 24
Pyrite oxidation and subsequent transport require only a
small amount of water and air. The atmosphere in a mine or over
a refuse dump is adequate for the basic stoichiometric reaction.
Water then collects the reaction products (acid salts) and
transports them out of the mine or off the refuse pile along with
solid wastes.
The equations shown clearly demonstrate that the production
of acid slurries by mine or beneficiation waste disposal
facilities can be completely independent of the mineral mined.
The critical factor is whether or not the pyrite occurs in the
host rock, which depends on whether,lrojn and sulfur existed in a
r%aucl%g"'erivi-rottment during the formation of the host rock. This
explains the widespread occurrence of pyrite and acid wastes in
the coal beds of the eastern United States and the absence or
near absence of pyrite and acid wastes in the coal beds in the
western United States. The coal beds in both locations were
deposited in a reducing environment, but the host rock of the
eastern United States was higher in iron and sulfur content
during deposition of the coal beds than was the host rock in the
western United States. In the case of the so-called hard rock or
240
-------
metallic minerals, most of the ore-producing hydrothermal
solutions were injected into the rock much later in geologic
time than when the host rock was formed. Because pyrite has
little to do with the origin of the ore mineral, it can be
associated with almost any ore.
Specific examples of some mines where the ores contain
pyrite are the copper mines near Butte, Montana, some of the
lead-zinc mines in northern Idaho, a cobalt mine in central Idaho
(currently inactive), gold and silver mines in Nevada, and some
molybdenum mines in Colorado.
Current best available estimates indicate that 25 percent of
the hard rock or metallic mineral mining and beneficiating
industries generate solid waste with sufficient pyrite to produce
acid water. Data for providing a more accurate estimate of the
percentage of the U.S. mining industries producing acid-containing
waste slurries should be available in 1980, when the
Assessment program has been completed.
Currently available control technologies for the prevention
of groundwater contamination from seepage and surface water
contamination by surface runoff from mine and beneficiation solid
wastes containing pyrites consist basically of preventing or
minimizing the initial production of acid water at the waste
source and preventing any acid waters that are formed from
reaching the surface waters and groundwaters. These technologies
are summarized below. No attempt has been made to identify the
best practicable control technologies.
241
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Two mechanisms are available to prevent the formation of
acid slurries through oxidation of pyrite at the source. The
first is to prevent water and/or air from reaching the pyrite.
This involves control of both groundwater and surface water
because of the interconnection between recharge areas, aquifers,
and discharge areas. Pumping wells, drain wells, and horizontal
wells are used to divert groundwater and surface water before
they enter into the atmosphere of a mine, thus preventing their
contact with the pyrite. Given sufficient hydrogeologic data, a
mine often can be planned so that such mechanisms are incorporated
into the development process, which minimizes the cost. Another
method is to isolate the pyrite from the water by burying the
pyrite in materials whose permeability is low enough to reduce
the rate of exposure to air and water to the point that the rate
of acid production will produce acceptable environmental
Control technologies for prevention or minimization of any
acid waters that are formed from reaching the surface waters and
j
groundwaters include the use of liners and seepage collection
2
devices, such as wells, drainage blankets, and trenches. The
success of these various control techniques depends on the
saturated hydraulic conductivity (permeability) of the liner
material. These control technologies must be applied when the
site selected for the waste disposal facility is not located over
a thick horizontal stratum of permeability equal to or less than
10 cm/s. Adequate separation of slimes and sands in tailings
242
-------
ponds can be expected to produce a saturated hydraulic conductivity
of 10 cm/s; however, this figure is based on the assumption
that the tailings pond is managed in such a way that the slimes
occupy the center of the pond and water is not allowed to back up
over the sand portion of the embankment. It is estimated that
only 30 to 40 percent of the tailings ponds in the United States
2
are now managed this well. Ordinarily the emphasis in tailings
pond management is to place the sand so as to achieve the highest
possible safety factor for the embankment. This may or may not
mean maintaining the water at a level that iininimizes seepage
through the tailings pond.
Sealing and flooding of eastern underground coal mines to
prevent the exposure of the pyrites to air and simultaneously
reduce the rate of escape of water from the mine are frequently
practiced and represent a combination of the two preventive
mechanisms described above. #
The uranium industry is essentially the only mining industry
now using clay, treated clay, or synthetic liners in tailing
ponds. Recent actions of the Nuclear Regulatory Commission (NRC)
has guided the uranium industry toward the use of liners, which
are discussed in the subsection on radioactive mineral resource
wastes.
The somewhat limited information now available on the problem
of the production of acid runoff from mineral resource disposal
piles containing pyrite rock will be augmented by information
currently being collected under the Regional Waste Management
243
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Plan Requirements of Section 208 of the Water Pollution Control
Act Amendments of 1972 and 1977. Some information on this subject
was made available to the coal industry when it was addressed in
detail in the Preamble to the Surface Mining Control and
Reclamation Act of 1977. It has also been addressed in the
regulations promulgated by the Office of Surface Mining,
Department of Interior. The technology for preventing or
minimizing environmental degradation from this source of
contamination consists primarily of soil amelioration with lime
and subsequent fertilization and revegetation of the wastes.
Mineral Resource Wastes Containing Radioactive Materials
Historically, the uranium mining industry has been considered
to have the most potential for adverse environmental impact
because of the radioactivity of this mineral. More recently,
however, studies have been made of the phosphate industry to
•(•
ascertain the potential of water and air pollution due to
radioactivity. Other selected mining industries being investigated
(by EPA's Office of Radiation Programs in Las Vegas) for potential
radiation problems are several copper companies whose smelters
are recovering uranium as a byproduct; selected iron mines; and
several much smaller industries, such as the mining of tungsten,
4
fluorspar, and bauxite.. The radiation from these industries
results primarily from the inherent characteristics of the host
rock, rather than from the mineral being mined.
The uranium industry appears to present the only .major
radiation problem, as a result of its impact on water (via radium
244
-------
226) and on air (via radon gas). Beneficiation tailings, where
radium is most concentrated, are the primary source of radiation.
Comparatively minor problems may occur from exposed radioactive
overburden that had previously been isolated from the environment
by overlaid soil layers; however, only limited information is
available concerning the potential of radioactivity problems from
this source. The proposed RCRA regulations (Federal Register,
December 18, 1978) do not cover uranium beneficiation tailings;
these tailings will be regulated through PL 95-604, the Uranium
Mill Tailings Radiation Control Act of 1978 (Federal Register,
November 8, 1978), which authorizes the EPA to set health and
environmental standards and the Nuclear Regulatory Commission to
regulate uranium tailings at both active and inactive sites. An
overview of the current status of the potential environmental
impact of uranium tailings is nevertheless included in order to
provide a complete assessment of this industry.
Uranium Mining and Beneficiation. The uranium mining and
beneficiation industry annually generates 156 million tons (141
Gg) of overburden and waste rock and 8 million tons (7.2 Gg) of
tailings. Approximately 60 percent of the mines are surface
operations and 40 percent are underground. In 1977 there were
64 producing mines in six states. New Mexico and Wyoming led in
uranium production. The annual production rate is increasing
rapidly, primarily because of the increasing demand for it as a
nuclear fuel element in nuclear power plants.
245
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Uranium is beneficiated from ores that usually contain from
0.05 to 0.30 percent uranium as U,0g. Water (from mines, wells,
or streams) and chemicals are used in the beneficiation process
to produce a semirefined solid product called yellowcake. Liquid
and solid wastes from this process are disposed of by impoundment
in large ponds. Adverse environmental impacts are primarily
attributable to seepage from these ponds and to emissions of
radioactive gases and particulates from the impounded solids.
Conventional beneficiation of uranium involves preparation
of the ore; leaching to bring the uranium values into solution;
separation of the pregnant solution; and precipitation of
yellowcake (U^Og). Vanadium, molybdenum, and copper byproducts
also may be produced. The ore is prepared by crushing and
grinding it to expose uranium-bearing particles. Sulfuric acid
or sodium carbonate (depending on the lime content of the ore) is
used in the leaching process. Separation of liquids and solids
is accomplished by continuous countercurrent decantation,
filtration, or sand-slime separation. Solvent extraction and/or
ion exchange may be used in the acid exchange. The yellowcake is
precipitated from the concentrated solutions by raising the pH
with sodium hydroxide, ammonia, lime, magnesium oxide, or a
combination of these reagents.
Pollutants in these wastes originate primarily from the ore
processed and from the reagents used in the beneficiating
operations. Expected major wastewater constituents include, but
are not limited to, radioactive species (radium, uranium, and
246
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thorium); organic compounds (such as phenol); inorganic ions
(sulfate, chloride, nitrate, and fluoride); light metals (sodium,
calcium, aluminum, magnesium, and titanium); and heavy metals
(arsenic, selenium, chromium, molybdenum, vanadium, silver,
copper, iron, manganese, nickel, lead, and zinc). The wastewater
has a high dissolved and suspended solids content, a moderately
high chemical oxygen demand, and unless neutralized, is extremely
acidic or basic. Generally, wastes from alkaline leach processes
contain a lower level of dissolved contaminants than wastes from
acid leach processes.
The current practice of impounding liquid and solid wastes
from the beneficiation of uranium can result in contamination of
groundwater supplies because of uncontrolled seepage from the
tailings ponds. Only a few new operations line these ponds to
mitigate seepage. In most operations, disposal of wastewater by
evaporation is augmented by seepage from unlined ponds, which may
account for up to 50 percent of the loss of total effluent
2
impounded.
Lining of tailings ponds is a recent advance in
state-of-the-art technology for containment of tailings. Clay
(treated or untreated) or synthetic liners may be used, each
offering advantages depending on site-specific conditions and the
wastewater involved. Clay liners are unsuitable if the acid-leach
process is used because the acid breaks down the clay. Because
about 81 percent (17 of 21) of the current operations use the
acid-leach process and most planned operations are the acic-leach
2 6
type, the trend is toward synthetic liners (e.g., Hypalon). '
247
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The tailings disposal area can emit significant amounts of
radioactive particulates and gases to the atmosphere. Radon 222
gas, formed by radioactive decay of uranium, can be emitted in
large quantities from both active and inactive tailings
impoundments. Dispersion of windblown tailings also can result
in potentially dangerous radioactive emissions.
Disposal of these tailings below grade by backfilling them
into open pit mines and underground mines is attracting increased
attention as a long-term solution requiring little or no
maintenance. Proper coverage of the surface of tailings
backfilled into open pit mines can effectively control both
groundwater and airborne radioactive contaminants.
Based on a modeling study conducted by Oak Ridge National
Laboratory to analyze the slope stability at an open pit mine, it
is concluded that backfilling of uranium tailings in an open pit
mine is technically feasible assuming the following ' :
0 A minimum 39 ft (12 m) thick liner and its protective
shell.
0 A maximum of 13 ft (4 m) freeboard.
0 Special construction to prevent seepage through the
highwall.
The Nuclear Regulatory Commission (NRC) has proposed the
following tailings-management performance objectives ' :
0 Reduction of direct gamma radiation from the
impoundment area to background level.
0 Reduction of the radon emanation rate from the
impoundment area to about twice that in the surrounding
environs.
248
-------
For backfilling below grade, the NRC proposed:
0 Individual cells be excavated to a depth of 40 to 60 ft
(12 to 15 m) below grade and sealed with synthetic
liners.
0 Sides be lined with 30 mil (0.76 nun) reinforced Hypalon
sheets and the bottom be covered with 30 mil (0.76 mm)
PVC.
0 15 ft (4.5 m) of overburden be placed on top.
Cost of Hypalon liner with 3-ply construction and polyester
scrim ranges from 55 to 64 cents per square:foot, compared with
20 to 30 cents per square foot for untreated clay liners. These
costs include site preparation and sterilization of the Hypalon
2
liners.
Battelle Northwest Laboratories is currently conducting a
demonstration project entitled "Evaluation of Groundwater
Transport of Uranium Mill Wastes" to evaluate the reliability of
using clay to line open pits that will be used for backfilling.
This evaluation for NRC involves a study of the interaction of
uranium acid leach wastes with clay minerals.
Phosphate Mining and Beneficiation. Recent investigations
of the extensive phosphate mining areas in central Florida
indicate that the potential radiation problem associated with the
active mining and beneficiation of phosphate is relatively
insignificant when compared with the radiation problem in the
8 9
uranium mining industry. ' Monitoring for radium 226 in both
groundwaters and surface waters in areas where phosphate tailings
are disposed of revealed no increase in this pollutant; in most
cases, the concentration of radium 226 was actually greater in
249
-------
8 9
nonmining areas. ' This phenomenon may be explained by the fact
that most of the uranium associated with phosphate ore is
contained in the phosphate rock being beneficiated or recovered
from the ore, and since very little phosphate rock leaves the
beneficiation plant via the tailings, very little uranium ends
up in the tailings pond. Because the process is not 100 percent
efficient, some phosphate rock does escape, the beneficiation
plant, allowing a small amount of uranium to end up in the
tailings. This does not present a major environmental problem
however, because the uranium tied up in the phosphate rock is
practically insoluble at the high pH conditions that usually
prevail in the waste slurry.
Excessive levels of radiation from radon gas have been
measured in studies conducted by the EPA Region IV Office of
Radiation Programs and the Florida Department of Health and
Rehabilitative Services. It was found that personal radiation
dosages in residences constructed in older reclaimed areas (in
which the current beneficiation and waste control practices were
not practiced) exceeded the Maximum Permissible Dose Recommendation!
of the National Council on Radiation Protection. Current
benef iciation methods concentrate the P2°5 an(* associated uranium
from both the phosphate:sands and fines (through flotation),
whereas previously only the* sands were processed and the
radioactive fines were left in the reclaimed areas. Current
control methods include keeping the tailings wet and burying the
waste tailings sands and radioactive overburden under inert
overburden.10'12
250
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Other Potentially Hazardous Mineral Resource Wastes
This miscellaneous group of mineral resource wastes poses a
potential threat to human health and the environment because of
their chemical and/or physical characteristics. The potentially
hazardous materials in these wastes result either from the
composition of the mineral being mined and beneficiated (i.e.,
some minerals contain hazardous levels of:constituents like
mercury, beryllium, or asbestos fibers) or from the addition of
hazardous substances as reagents during benefication operations
(e.g., sodium cyanide or copper sulfate).
The potentially hazardous wastes in this category are not as
voluminous or as broadly distributed as the other hazardous
mineral resource wastes discussed in this section (e.g., pyritic
solid wastes from eastern coal mining activities). The waste
problems addressed here involve relatively few operations within
several different mineral mining industries.
Solid Wastes Containing Asbestos Fibers. A particle is
generally defined as asbestos if it has an aspect ratio of
greater than 3 to 1 and if it is serpentine, chrysotile, or one
of the amphiboles in the generic classes—antophyllete,
treniolite-actinolite, crocidolite, and cummingtonite-grunerite
(amosite).
Rock types in which asbestos minerals might be encountered
lie at or near the surface of about 30 to 40 percent of the
continental United States. The type and amount of asbestos
fibers in these areas vary considerably. Important mineral
251
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deposits are sometimes found in areas where asbestos materials
occur, and the recovery of these minerals presents a potential
for the release of asbestos fibers to the environment.
On several occasions scientists and regulators have
exhibited concern about the release of asbestos fibers into the
environment as a result of mining and beneficiating activities.
Perhaps the best known case in the United States involves the
Reserve Mining Company's discharge of taconite tailings into Lake
Superior. This taconite processing facility on the shores of
Lake Superior, in the Silver Bay area, has been discharging about
67,000 tons (61 Mg) of tailings into the lake daily for about 22
14
years. These tailings not only contain trace amounts of
several metals, but also billions of asbestos fibers. The heavier
fibers sink to the bottom of the lake, but the prevailing current
carries the lighter, buoyant fibers to Duluth, Minnesota, and
Superior, Wisconsin, where they enter the drinking water supplies.
Several citizen groups in these areas became greatly concerned
about both air and water pollution problems associated with the
Reserve Mining Company operation, and numerous legal battles
resulted. After several years, the Federal Appeals Court ordered
the Reserve Mining Company to take immediate steps to curb air
pollution- problems and'to convert to an on-land tailings disposal
system. Since this order, .the company has agreed to modify its
beneficiating plant and to incorporate air pollution control
practices that will lower the level of asbestos fibers in the
ambient air. The company has also started construction of a
252
-------
massive tailings pond near Lox Lake, at Milepost 7 along its
railroad spur. The total cost of the pollution control project
is estimated to exceed $370,000,000. About $75,000,000 has
already been spent, most of which has gone toward the completion
of the air pollution control system. The remaining dollars will
be used to complete the on-land disposal system.
Other mining and beneficiating operations that have received
attention due to the release of asbestos to the environment
include the direct mining of asbestos and selected operations
within the vermiculite, copper, gold, and talc mining industries.
The exact number of operations that pose potential asbestos-related
problems is not known, but it is estimated to be quite small, and
it is questionable if any of these really causes a significant
adverse environmental impact. Some of the operations that have
been identified as potential generators of asbestos fibers are
(1) three asbestos operations, one each in Vermont, California,
and North Carolina; (2) one vermiculite operation in Montana; (3)
one gold mine in South Dakota; (4) several copper operations in
Arizona; (5) several talc operations in Vermont, Montana, and New
York. Although other isolated mining and beneficiating operations
no doubt handle minerals containing asbestos, again it is doubtful
that they pose a significant adverse environmental impact.
It is estimated that less than 5 million tons (4.5 Gg) of
mineral resource wastes are generated annually by those
industries that may be releasing potentially hazardous levels of
253
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asbestos fibers to the environment.* This represents less than
0.3 percent of the total annual production of all mineral
resource wastes.
A recently conducted survey involved the analysis of water
samples taken at or near six domestic mining and beneficiating
operations where asbestos-containing minerals are being handled.
The facilities included two asbestos operations and one operation
each involving the recovery of gold, copper, talc, and vermiculite,
The results indicated that asbestos was present in the streams
neighboring these operations, which is not surprising because the
streams are eroding and transporting materials from local
asbestos-bearing rock. The study also indicated that asbestos
fibers were present in mine pumpout waters, surface runoff, and
tailings. The greatest concentrations were usually detected in
the tailings.
The concentrations of asbestos fibers in the different
sources tested ranged greatly. At one site the final asbestos
9
effluent levels from the tailings pond were as high as 280 x 10
j
fibers per liter on one of the sampling days, but when the same
location was tested on another day it yielded samples with no
detectable asbestos. This variation is probably due to several
factors, including the amount of precipitation and runoff during
and prior to sampling and the amount of material flowing through
the process.
* PEDCo engineering estimate based on calculations made in
this study and literature values.
254
-------
The main conclusion drawn from this survey is that asbestos
levels in streams near the sites sampled were highly dependent on
seasonal variations in precipitation and runoff, and in most
cases the stream levels of asbestos showed little increase due to
mining and beneficiating operations. The results of the study
also show that although substantial amounts .of asbestos fibers
are sometimes found in tailings, they are .effectively contained
by the tailings pond, and the asbestos levels of discharges from
these ponds are within Federal and state regulatory effluent
limitations.
i
Although air monitoring has been somewhat limited at those
mining and beneficiating operations that handle asbestos-containing
minerals, it is generally accepted that environmental and health
problems related to the release of asbestos into the air are of
more concern than those associated with its release into surface
waters and groundwaters.
Virtually every process step in the mining and beneficiation
of asbestos-containing minerals is a potential generator of
asbestos fibers. Operators have tried to minimize the generation
of emissions by utilizing conventional fugitive dust control
methods as described in Section 4, such as wet drilling and wet
beneficiating techniques. Haul roads and dried portions of
tailings ponds are also major sources of fugitive particulates
that can contain high concentrations of asbestos. These sources
are generally controlled by watering (with and without wetting
agents), but in some cases cohesives are used.
255
-------
Individual process sources (e.g., drilling, crushing,
hauling) have received very little monitoring for asbestos
fibers, but the air quality in the general vicinity of asbestos
mining and beneficiating operations has been monitored on several
occasions. The most detailed studies of an asbestos mining
community (the chrysotile mining areas of Quebec, Canada) were
begun in 1966 and are still in progress. ' Similar studies on
a smaller scale have been conducted in the United States, the
U.S.S.R., and Italy. The Quebec studies have shown that a
tremendous amount of ambient dust has been •, generated over the
years by mining and processing activities and by winds blowing
over dried tailings. Even as late as 1974, after dust emission
controls had been improved over those of the earlier years as a
result of practices like wet drilling and watering of haul roads,
emissions of particles from chrysotile mining and beneficiating
operations in the Province of Quebec amounted to 154,000 tons
(140 Mg), of which about 4 percent 6,170 tons (5.6 Mg) was
18
asbestos dust.
Recently, concern has arisen about the possible health
hazards associated with the quarrying of serpentine rock at
Hunting Hill quarry near Rocksville, Maryland, and its use as a
surface material for roads, playgrounds, and parks. Air samples
taken near the quarry site showed chrysotile mass concentrations
of from 0.02 to 64 ng/m3 or 2 x 10~6 to 5 x 10~3 "standard
fibers" per cm of air.* These concentrations are well below the
* U.S. bureau of Mines, State of Maryland, and McCrone
Assoc., unpublished data.
256
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Federal limits for asbestos content in air [2 fibers/cm (OSHA)
and 5 fibers/cm (MESA)], where a fiber is defined as longer than
5 ym, less than 5 ym wide, and having a length-to-width ratio of
19
3:1 or greater.
Based on both monitoring surveys such: as those described
above and a number of epidemiological studies, scientists have
concluded the following concerning health .risks from asbestos in
and around the mining and beneficiating activities: (1) the
cancer incidence among those employed in mining and beneficiating
activities involving the handling of minerals associated with
asbestos does not appear to be excessive compared with that of
the national populace; (2) although a significant health risk has
been well documented for those who work in the commercial
asbestos trades (particularly for those workers who smoke), the
risk appears to be much lower for those employed in mining and
beneficiating activities and those residing in the areas of such
activities. '
Mineral Resource Wastes Containing Heavy Metals. Heavy
metal constituents are of primary concern because of their
potentially toxic nature. The combination of acid-forming
minerals (pyrite) and heavy metals in a mineral deposit creates
undesirable and potentially hazardous conditions. The acid
waters increase the solubility of the heavy metals in the wastes,
which often results in concentrations of heavy metal cations in
excess of state and Federal drinking water standards and
discharge standards.
257
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The industries in which this problem can be of particular
concern are eastern coal mining and some nonferrous metal mining
operations such as copper, lead, zinc, and molybdenum. Each of
these represents a major mining industry as measured by the
amount of ore mined, the quantity of solid wastes produced, and
geographic distribution.
Other less significant industries that present a potential
hazard because of the presence of heavy metals are the mining and
beneficiating of beryllium and mercury. Although these two
industries are quite small from the standpoint of solid waste
generation and geographic distribution, the potential for impact
on human health and the environment resulting from activities in
these industries needs to be identified and clarified.
Beryllium Industry. The domestic beryllium industry is
relatively small compared with other mineral mining and
beneficiating industries. Beryllium ore is now mined on a large
scale at only one operation, which is in a very remote area in
the Spor Mountain district of Utah. Beryllium ore is mined at
this operation by open-pit methods and the ore is hauled to the
beneficiating plant near Delta, Utah, where it is converted to
impure beryllium hydroxide. In past years, some beryllium ores
were mined in Colorado and South Dakota by crude open-cut and
hand-picking methods. These operations, which were small, have
not been active since 1972.
Domestic beryllium production data and solid waste data are
withheld to avoid revealing individual company data. Based on
258
-------
calculations made in this study, it is estimated that annual mine
and beneficiation wastes from the beryllium industry are less
than 2 million tons (1.8 Gg).*
The environmental and health impacts associated with solid
wastes from the beryllium industry are minimal. They are limited
primarily to the direct impact on the land on which the wastes
are disposed. There is little problem with fugitive dust at the
mine because of the large particle size and high moisture content
of the mine wastes being handled. Haul roads periodically
cause some dust problems, but these are minimized by watering.
Beneficiating operations generate some fugitive dust, but the
quantities are small because the processing operations are wet.
Tailings ponds do pose some threat to the environment because of
minor amounts of potentially hazardous materials contained in
the tailings. The wastes could possibly contain some uranium,
since uranium is present in beryllium-containing ore. The
uranium, as well as small amounts of beryllium that may be
present in tailings, could be hazardous if these particles
should become airborne. The potential of this problem is being
minimized by keeping the waste in active portions of the pond
covered by water and applying vegetative stabilization to
abandoned portions of the tailings pond as they become inactive.
The arid climate practically precludes surface water and
groundwater pollution problems at the mine. Annual rainfall is
* PEDCo engineering estimate based on calculations made in
this study and literature values.
259
-------
only 6 to 8 inches (15 to 20 cm), and the only potential source
of surface water or groundwater pollution in the beneficiating
operations is the tailings disposal area. The tailings have a pH
of 8 to 10 and are exceptionally high in dissolved solids (18,380
mg per liter), consisting largely of sulfate (10,600 mg per
liter), fluoride (45 mg per liter), aluminum (552 mg per liter),
beryllium (36 mg per liter), and zinc (19 mg per liter). The
presence of some of these constituents could cause this waste
stream to be considered potentially hazardous. There is no
discharge from the tailings pond because evaporation greatly
exceeds precipitation in this arid area. Some loss of pond water
could occur from seepage and percolation into the subsurface (the
pond is not lined), but it is not certain if this is a problem
because no monitoring has been done in the area.
Mercury Industry. The primary mercury industry in the
United States is very small. Low prices and slackened demand
caused this industry to decline steadily during the early and
mid-1970"s. During this same period, the environmental hazards
and extremely toxic nature of mercury came under public scrutiny.
Thirty-seven U.S. mines were producing mercury ores in 1972,
22
down from 56 in 1971.: The number dropped to 24 in 1973, and to
just 2 mines in 1974.' During the last several years, however,
the mercury mining industry has experienced some growth, and 13
23
mining operations were producing refined mercury in 1977. Most
of this mercury production was in Nevada, and the balance was in
California. A single open-pit mine in Nevada, opened in May
260
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1975, is currently responsible for about 70 percent of total
23
domestic primary mercury production. In the past, mercury was
recovered from ore in Arizona, Alaska, Idaho, Oregon, and
Washington and as a byproduct from gold ore. in Nevada and zinc
ore in New York. All of the operations in these states are now
closed because of low prices and inability to meet environmental
protection standards. In the past, most mercury ores were
recovered from underground mines, but all the present mines are
open-pit.
The total annual production of mineral resource wastes for
the mercury industry is estimated to be about 3,000,000 tons
(2.7 Gg) in 1977.* This total consists of about 2,750,000 tons
(2.5 Gg) of mine wastes and 250,000 tons (227 Mg) of tailings.*
Currently all mine wastes are backfilled into the mine, used in
tailings dam construction, or dumped on land adjacent to the mine
site. Mine wastes vary somewhat in composition, but they
usually contain chert (a mineral composed chiefly of silica), and
sometimes pyrite and sulfur. Mine wastes from mercury mining are
generally not considered to present a significant threat to human
health and the environment because (1) any toxic metals present
are usually in low concentrations; (2) acid-forming minerals
present are usually in small enough concentrations to preclude
formation of acid waters; (3) runoff and percolation problems are
minimized because most mines are located in fairly dry areas. In
* PEDCo engineering estimate based on calculations made in
this study and literature values.
261
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addition, most of the mine wastes contain sufficient plant
nutrients to support vegetation on the surface of the waste
piles, which enhances both the time required and the degree to
which these materials stabilize.
The type of beneficiation wastes generated at mercury
processing operations depends on the method used to concentrate
the ore. Tailings are generated at facilities using froth
flotation, but a dry calcined waste is generated from the roasting
furnace and retort at facilities recovering mercury by heating.
Both types of wastes are disposed of on land near the processing
facility. The calcined wastes do not contain any potentially
22
hazardous materials. Tailings from flotation are likely to be
high in suspended solids, and some of the flotation reagents may
also be washed out with the tailings. Although the total
dissolved solids loading may not be extremely high, a relatively
high concentration of dissolved heavy metals can result from the
beneficiating of highly mineralized ore. Also, depending on
beneficiating conditions, the waste stream may have a high or low
pH. This is of concern because it affects the solubility of the
21
waste constituents.
Wastes Containing Potentially Toxic Beneficiation Reagents.
This category of mineral resource wastes includes those
beneficiation wastes that may adversely impact the environment
because they contain potentially toxic processing reagents.
Possible adverse environmental impacts from the use of toxic
reagents include contamination of surface and groundwaters and
262
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interference with vegetative stabilization of disposal areas.
Reagents are used for various functions during beneficiation
(e.g., collecting, activating, depressing), and some portion of
these reagents leave the process with the tailings and end up in
settling ponds. Although all reagents do not pose a significant
threat to the environment (e.g., those associated with most of
the nonmetal industries), the toxic nature of certain ones may
have an adverse effect. The reagents that have received the most
attention are sodium cyanide and copper sulfate, but there are
several organic flotation reagents used at some beneficiating
operations that may also present potential toxicity problems.
The matter of the toxicity of processing reagents is quite
uncertain and undefined, primarily because of the complex chemical
environment surrounding a typical discharge from beneficiating
plants using potentially toxic reagents. Available data indicate
21
that only a broad range of tolerance values is known. More
analytical testing and bioassay experiments are needed.
No data are available from which to determine the quantity
of mineral resource solid wastes that contain potentially toxic
reagents. To obtain this information, it would be necessary to
survey the industry to determine which operations are using the
reagents, after which field and laboratory sampling and analyses
would be required to determine how much waste actually contains
reagents. The use of potentially toxic processing reagents is
generally limited to certain operations within the nonferrous
metals sector of the mining industry. Organic agents are used at
263
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several nonferrous metals operations (e.g., lead, zinc, copper,
molybdenum). Sodium cyanide is used primarily as gold and
silver recovery facilities. Copper sulfate is used at a number
of operations involved in the recovery of copper, lead, zinc,
gold and silver.
At facilities using potentially toxic reagents, the tailings
are adequately treated in retention ponds so that the final
discharge from the ponds meets NPDES permit standards; however,
monitoring data are lacking regarding the extent of the escape of
these reagents from the ponds via seepage and percolation.
The most efficient way to abate potential environmental
problems would be to eliminate the use of the reagents. A great
deal of research is being conducted by reagent suppliers, the
Bureau of Mines, and the mining industry to find suitable
substitutes for potentially toxic reagents.
Combining of Mineral Resource Wastes
Some large metal mining companies are partially or fully
integrated vertically. These companies operate mining,
beneficiating, smelting, and refining operations in the same
general area. Some integrated facilities also include operations
such as fertilizer and sulfur production plants.
Most integrated facilities usually take great care to
segregate the waste streams"produced by each individual operation,
In some cases, however, the combined wastes are disposed of in a
common area. A typical example of this practice is the discharge
of one or several wastes from smelting, refining, fertilizer
264
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production, and/or sulfur production into tailings ponds. In
some cases these wastes are also combined with mine wastes, but
this practice is normally limited to situations where mine wastes
are used in the construction of tailings ponds. Combined wastes
are of particular concern because they produce a unique waste
that is entirely different from that of ordinary mine or
beneficiation wastes.
Although wastes are combined in several different mining
industries, it occurs most frequently in the copper, lead, and
zinc industries. There are several large operations within each
of these industries where some combining of wastes occurs. The
extent to which mine and beneficiation wastes are combined with
wastes from other processing operations is not known. Although a
data base for this determination is not available, an estimated
annual production of 50 to 100 million tons (45 to 91 Gg)* of
mineral resource wastes appears reasonable.
The facilities that combine wastes use the same control
techniques as those used at other mine and beneficiation sites.
Tailings ponds receiving combined wastes are not lined, and
efforts to control percolation, seepage, and runoff problems are
usually minimal. A few sites have groundwater monitoring programs,
but they are neither extensive nor complete.
Airborne Fugitive Emissions From Mine Wastes and Tailings Ponds
Fugitive dust from mineral resource solid wastes is
generated primarily by windage of overburden storage piles and
* PEDCo engineering estimate based on calculations made in
this study and literature values.
265
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dry, inactive tailings ponds. Less significant fugitive dust
emissions result from the handling of dried tailings and
excavated overburden (e.g., the construction of tailings
embankments and the relocation of overburden during reclamation
operations). These fugitive dust sources related to mineral
resource solid wastes are part of the many fugitive dust sources
associated with mining and beneficiating operations, including
scalping; overburden drilling, blasting, handling, and removal;
orebody drilling, blasting, removal, transport, and crushing;
mine-vehicle traffic over unpaved haul roads; orebody and
beneficiating product storage piles (from windage); and exposed
mine-area surfaces (from windage). Unpaved roads and overburden
excavation are usually the major sources.
During high winds, the fugitive dust emanating from dry,
inactive tailings ponds in the arid West and Southwest can have a
significant impact on the particulate air quality of the
immediate surrounding area. The impact of the vast copper
tailings in these parts of the country is a good example. This
I
is of particular importance in those relatively few situations
where these operations are proximate to population centers.
Overall, however, the contribution of fugitive emissions from
remotely located tailings ponds to the total suspended particulate
ambient concentration of an. encompassing area such as an Air
Quality Control Region (AQCR) is relatively insignificant when
compared with other common fugitive dust sources in these areas,
such as agricultural lands, unpaved public and private roads, and
266
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even the other mine-related fugitive dust sources. For example,
estimated fugitive emissions from overburden, waste rock, and
tailings in the Denver, Colorado, AQCR amounts to approximately
2 percent of the total fugitive emissions in this area; unpaved
roads account for approximately 50 percent, and agricultural
sources for another 20 percent.
Airborne emissions of hazardous materials, including
radionuclides from uranium tailings and solid wastes from the
mining and beneficiating of asbestos and, to a very limited
extent, minerals containing asbestos (vermiculite, copper, gold,
and talc), have been described and discussed earlier in this
section. Emission factors for fugitive dust sources associated
with mine solid waste were summarized in Section 5.
The control technology for fugitive dust from mineral
resource solid wastes is to apply physical, chemical, and
vegetative techniques, or combinations of these, to stabilize the
surface of the overburden and tailings and thus prevent airborne
emissions. These stabilization and control techniques are
described and discussed in detail in Section 4.
Identification of Mineral Resource Solid Waste Problems by Industry
A priorities-ranking system has been developed in an effort
to identify the mining industries that pose the greatest relative
impact to human health and the environment as a result of the
solid wastes they produce. The priorities are based on five
criteria chosen to judge the potential adverse impacts associated
with the various industries covered in this study. (Table 26;
267
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TABLE 26
RANKING OF POTENTIAL ENVIRONMENTAL
IMPACT BY MINERAL
1.
Criteria*
RCHA criteria
• a. Hatardous
b. Nonhaiardoua
0
0
20
10
(0
10
100
so
2. Total quantity of mineral resource
wastes
Priority rating
(Bated on million tons p«r year)*
3. Number of domestic mints
Priority rating
(Baaed on total number of nunas)S
4. Projected growth/decline of
industry
Priority rating
(Based on percent of change
0 10 20 40
1'5) (ft-25) (24-75) >75
0 10 20 40
(1-10) (11-251 (24-100) <>100>
0 i 15 30
«0-5) (6-15) (16-50! ( '501
Metals
Bauxite
Copper
Cold
Iron ore
Lead
Mercury
Molybdenum
Silver
Uraniuir.
Zinc
Other'
Mennetalt
Asbestos
Clays
Diatomite
Feldspar
Gypauir.
Mica (acrapl
Perlite
Phosphate roc*
Potassium salts
Pumice
Salt
Sand and gravel "
Sodium carbonate
Stone
Distension .
1 HI
• o
60
20
20
60
20
20
20
100
to
0
20
0
0
0
0
0
0
20
0
0
0
0
0
0
0
Talc, loapstone. pyrophyllite
Other* :
Mineral Fuels
Coal (anthracite,1
bituminous, and lianite)
• fee Append i> D (or a
• Values based on dsts
1 Values bssed on data
0
to
Kb}
10
30
10
30
30
0
10
10
30
10
0
0
10
0
0
10
0
30
0
0
0
10
0
10
0
0
0
so
n explanation of the
contained
contained
9roup metals, rare earth metals, tin.
in Table
in Table
titanium.
2 3 ;
10 10
40 20
10 20
40 20
10 20
0 10
10 0
0 20
40 40
10 20
10 0
0 0
20 40
0 10
0 10
10 20
0 10
0 10
40 20
10 0
0 40
0 10
30 40
10 0
30 40
0 40
0 30
10 0
40 40
criteria uaed
7 of thia doctd
2 of this docui
4
0
30
30
30
IS
0
30
15
30
IS
30
30
30
30
IS
5
5
S
30
5
30
30
30
10
30
S
30
IS
IS
in this
cent.
sent.
ilmenite, tunqatan, va
a Abbraaives. aplite, barite, boron minerala. fluorspar.
•a t 11
araphite
Total score
30
ISO
90
14C
135
30
70
65
240
135
40
SO
100
40
35
35
25
15
140
15
70
40
120
40
100
45
SO
2S
205
table.
nun
nadium.
•
260
-------
see Appendix D for explanation of each criterion used to establish
priorities.) Each criterion was weighted according to its
relative importance. Criterion l(a) carries the most importance
and Criterion 4, the least. Within each criterion four arbitrary
values are assigned to indicate the degree to which that criterion
applies to each industry. For example, Criterion l(a) deals
with hazardous wastes from mining and beneficiation. If a
specific industry generates an insignificant amount of hazardous
wastes, it receives a value of 0 for that criterion; if hazardous
wastes are a minor problem in the industry, the industry receives
a value of 20; if hazardous wastes are a major problem, it
receives a value of 100.
After values have been assigned for each criterion, the
values for a particular industry are totaled. Industry totals
can then be compared to determine which industries are likely to
have the greater impact on the environment.
Despite the quantitative "total score" ranking of each
mineral industry, however, the end result is at best a qualitative
ranking of these industries. Thus, the listing cannot be
interpreted to mean the adverse environmental impact from
uranium, for instance, is six times greater than that from
diatomite. In fact, rankings for minerals such as diatomite are
based exclusively on criteria that measure the size and extent of
an industry, i.e., RCRA criteria (impact from hazardous and
nonhazardous wastes) are not involved, and these industries are
actually considered environmentally insignificant on the whole.
269
-------
Although this priority ranking of individual mineral
industries is arrived at by a seemingly somewhat arbitrary process,
it does reveal the major industries (e.g., uranium, coal, copper,
phosphate) that would be expected to have the greatest adverse
environmental and health impacts.
This listing and the discussion in this section should
provide background information needed to develop a long-term
strategy regarding the role of the Federal Government in the
control of industrial solid wastes.
270
-------
REFERENCES FOR SECTION 7
1. Williams, R.E. Waste production and disposal in mining,
milling, and metallurgical industries. San Francisco,
Miller Freeman Publications, 1975. 489 p.
i
2. Personal communication. R.E. Williams, professor of
hydrogeology, University of Idaho, to R.S. Amick, PEDCo
Environmental, Inc., August 5, 1978.
3. Personal communication. Selected experts in various state
and Federal agencies, to Dr. R.E. Williams, professor of
hydrogeology, University of Idaho. August 1978.
4. Personal communication. V.E. Andrews, Field Surveillance
Branch, Office of Radiation Programs, to R.S. Amick,
PEDCo Environmental, Inc., August 22, 1978.
5. Personal communication. F.L. Galpin, Director of the
Environmental Analysis Division, Office of Radiation
Programs, U.S. Environmental Protection Agency, to
Mr. R.S. Amick, PEDCo Environmental, Inc., October 20,
1978.
6. Jackson, B., W. Coleman, C. Murray, and L. Sciute. Draft
executive summary report - Environmental study on uranium
mills, U.S. Environmental Protection Agency, Effluent
Guidelines Division, Washington, D.C. by TRW, Inc.,
Redondo Beach, California. December 1978.
7. U.S. Environmental Protection Agency. Impacts of uranium
mining and milling on surface and potable waters in the
Grants Mineral Belt, New Mexico. Environmental Protection
Publication 330/9-75-001, National Enforcement
Investigations Center, Denver, Colorado, September 1975.
40 p.
8. Personal communication. Dr. D.E. Garlander, Ardmann and
Associates, to R.S. Amick, PEDCo Environmental, Inc.,
October 1978.
9. Personal communication. Dr. W.E. Bolch, University of
Florida, to R.S. Amick, PEDCo Environmental, Inc.,
August 29, 1978.
10. Personal communica-tion. Mr. H.R. Payne, Chief of Environmental
Radiation Section for Region 4, Environmental Protection
Agency, to R.S. Amick, PEDCo Environmental, Inc., October
15, 1978.
271
-------
11. Florida Department of Health and Rehabilitative Services,
Radiological Health Services. Study of radon daughter
concentrations in structures in Polk and Hillsboro
Counties. January 1978.
12. Personal communication. S.T. Windham, Chief of Environmental
Studies Branch, Environmental Protection Agency, Montgomery,
Alabama, to R.S. Amick, PEDCo Environmental, Inc., August
27, 1978.
13. U.S. Environmental Protection Agency. Asbestos fibers in
discharges from selected mining and milling activities.
Final report, part III. Environmental Protection
Publication 560/6-77-001. Washington, U.S. Government
Printing Office, 1977.
14. Reserve mining: An epic battle draws to a close.
Environmental Science and Technology. October 1977.
15. Pollution control program for Reserve Mining will proceed
despite unresolved tax problem. Engineering and Mining
Journal. August 1978.
16. McDonald, J.C., and M.R. Becklake. Asbestos-related disease
in Canada, Helte Unfallheilkunde^ 126,2.
Deutsch-Osterreichisch-Schweizerische, Unfalltagung in
Berlin, 1975, Springer-Verlag, Berlin, 521-535. 1976.
17. McDonald, J.C., M.R. Becklake, G.W. Gibbs, A.D. McDonald,
and C.E. Rossiter. The health of chrysotile asbestos
mine and mill workers of Quebec, Arch. Environ. Health,
28: 61-68, 1977.
18. Brulotte, R. Study of atmospheric pollution in the
Thetford Mines area, cradle of Quebec's asbestos industry.
Atmospheric Pollution, M.M. Benarie, ed. Elsevier Sci.
Pub., Amsterdam, 447-458. 1976.
19. Malcolm, R. The "asbestos" minerals: definitions,
description, modes of formation, physical and chemical
properties, and health risks to the mining community.
National Bureau of Standards Special Publication 506.
Proceedings of the Workshop on Asbestos, Definitions and
Measurement Methods; held at NBS, Gaithersburg, Maryland,
July 18-20, 1977. Issued November 1978.
20. Personal communication. K. Poulson, Brush Wellman, Inc.,
Salt Lake City, Utah, to J. Greber, PEDCo Environmental, Inc.
December 1976.
272
-------
21. U.S. Environmental Protection Agency. Development document
•for interim final and proposed effluent limitations
guidelines and New Source Performance Standards for the
mineral mining and processing industry, point source
category. Environmental Protection Publication
440/l-76/059a, Group II. Washington, U.S. Government
Printing Office, 1976.
22. Midwest Research Institute. A study of waste generation,
treatment, and disposal in the metals mining industry,
for Environmental Protection Agency, Solid Waste
Management Division, Washington, PB-261052, October 1976.
23. U.S. Bureau of Mines. Mineral Commodity Summaries 1978.
Washington, D.C., U.S. Government Printing Offices.
24. PEDCo Environmental, Inc. Technical guidance for control
of industrial process fugitive particulate emissions.
Environmental -Protection Agency Publication No. 450/3-77-010
Environmental Protection Agency, Office of Air and Waste
Management, Research Triangle Park, North Carolina,
March 1977.
/
25. PEDCo-Environmental Specialists, Inc. Investigation of
fugitive dust - sources, emissions, and control. Prepared
for the Environmental Protection Agency, Region 9,
Contract No. 68-02-0044, Task Order No. 9, May 19,73.
273
-------
APPENDIX A
The agencies and their personnel who met with PEDCo
personnel during the course of this study are listed below:
U.S. Bureau of Mines, Washington, D.C;
Paul Marcus Division of Environment
Andy Corcoran Division of Environment
T.P. Flynn Division of Environment
Kenneth Higbie Division of Solid Waste
Monte Shirts Division of Solid Waste
John Morning Division of Ferrous Metals
U.S. Bureau of Mines Research Center, Spokane
Roy Soderberg
Roger Bloomfield
U.S. Environmental Protection Agency, Washington, D.C.
Tim Fields Office of Solid Waste
Kurt Jakobsen Office of Energy, Minerals and
Industry
Don 0'Bryan Office of Energy, Minerals and
Industry
Jon Perry Office of Solid Waste
Bruce Weddle Office of Solid Waste
Al Galli i Effluent Guidelines
Ron Kirby Effluent Guidelines
U.S. Environmental Protection Agency, Cincinnati
Ron Hill Industrial Environmental Research
; . Laboratory
Gene Harris Industrial Environmental Research
Laboratory
Appalachian Regional Commission, Washington, D.C.
Dr. Dave Maneval
U.S. Forest Service, Washington
Edward Johnson
274
-------
National Academy of Science, Washington, D.C.
George White Executive Secretary, Committee on
Chemistry of Coal Utilization
Interstate Mining Compact, Lexington
Kenes Bowling
Georgia Department of Natural Resources, Atlanta
Moses McCall Chief, Land Protection Branch
Sanford Darby Program Manager, Surface Mined
Land Reclamation Program
The government agencies and their personnel who were
contacted by letter or telephone during the course of this study
include:
U.S. Bureau of Mines, Washington, D.C.
Tovio Johnson Division of Ferrous Metals
U.S. Bureau of Mines Research Center, Salt Lake City
Parkmen Brooks
U.S. Forest Service, Washington, D.C.
James Neuman
George Holmberg
U.S. Forest Service, Ogden, Utah
William Johnson
Colorado Division of Radiation and Hazardous Waste Control
Al Hazel
New Mexico Environmental Improvement Agency, Santa Fe
Al Top
275
-------
APPENDIX B
TABLE 27
SUMMARY OF STATE AMBIENT AIR QUALITY
STANDARDS AND FUGITIVE DUST REGULATIONS*
Jurisdiction
Primary Standard
Secondary Standard
Fugitive Duit and Dustfall
Alabama
Alaska
Arizona
Arkansas
Federal (75 ug/m annual geometric
mean of 24-hr concentration)
Federal
Federal secondary
Federal
Federal (60 wg/m annual geometric
mean of 24-hr concentration)
Federal
Air Quality Goal: 100 ug/m
maximum 24-hr average
Federal
N)
California
Colorado
Nonvehlcular standards and regula-
tions are set by counties
Federal
Federal
Connecticut
Federal
Federal
• Afflick, R.S.,and K.A. Axetell. Evaluation of fugitive dust emissions from mining.
PEDCo Environmental, Inc., Cincinnati, under contract 68-02-1321. Prepared for U.S.
Environmental Protection Agency, June 1976.
(continued)
No fugitive dust beyond property
line. Abatement: Reasonable pre-
cautions, plus first three par-
agraphs of Federal model.
No visible dust past property line.
Abatement: First three paragraphs of
Federal model.
Fugitive dust from hauling, handling,
crushing,or conveying of materials
must be controlled by reasonable
means.
May not exceed 75 ug/n for any 24-
hr period or ISO ug/m for any 30-
minute period (measured on property
and subtracting background). Abate-
ment: Reasonable precautions. Dust
fall: maximum IS tons/mile /month.
Particles larger than 60 microns nay
not exceed 120/cm /24 hrs.
Fugitive dust regulations are devised
by each county. Those with appli-
cable regulations call for "reason-
able precautions."
If emissions are judged by a panel to
be "objectionable," may require use
of "best practical method" of con-
trol. Controls must be applied dur-
ing nonworking hours as required to
control dust. No visible emissions
may cross property 'line.
reasonable precautions, plus Federal
model, except paving of roads not re-
quired and agricultural operations
nitaA not sunnreaa dust. No discharge
beyond property line if: 1) visible
near ground, 2) impinges on building
or structure.
-------
TABLE 27. (continued)
Jurisdiction
Primary Standard
Secondary Standard
Fugitive Dust and Dustfall
M
Delaware
District of
Columbia
riorida
Georgia
Hawaii
Idaho
Illinois
Indiana
70 gg/m annual geometric mean of 24-
hr concentration. 200 ug/m 24-hr
average concentration, not to be .ex-
ceeded more than once per year. 500
ug/m 1-hour average.
Federal
Federal secondary, except in Dade,
Broward, and Palm Beach Counties, -
where the following apply: SO ug/m
annual geometric mean. 180 ug/m3
maximum 24-hr concentration.
Federal
100 ug/m during any 24 hrs.
55 pg/m3 annual arithmetic mean
during any 12-month period.
Federal
Federal
Federal
Federal
Federal, plus no degradation of
regional air quality permitted.
Federal
Federal
Federal
Federal
Water, chemicals, or approved tech-
niques must be used to control dust
emissions during demolition, grad-
ing, land clearing, excavation, and
use of unpaved roadways.
Federal model, except that agricul-
tural operations receive no specific
mention.
Fugitive dust in excess of process
emissions rate is prohibited. Rea-
sonable precautions to abate fugitive
dust are required.
Federal model
No visible dust past property line.
Ground level concentration at a point
selected by the Department may not
exceed 150 ug/m^ ab6ve background.
Dust fall may not exceed 3.0 grams
per square meter per 14 days. Abate-
ment by Federal model, except that
Director may determine that "best
practical" measures are sufficient.
"All reasonable precautions" plus
Federal model.
No emissions larger than 40 microns
mean diameter. No emissions beyond
property line visible when looking
toward zenith. Not applicable in
winds greater than 25 mph.
No visible dust over property line.
May not exceed 166 percent of upwind
values, nor more than 50 nq/m3 at
ground level above background more
than 60 minutes.
(continued)
-------
TABLE 27. (continued)
Jurisdiction
Primary Standard
Secondary Standard
Fugitive Oust and Dustfall
Iowa
Kansas
Kentucky
Federal
Federal
Federal
Federal
Federal
Federal
to
>J
CO
Louisiana
Federal
Federal
Maine
Maryland
100 gg/m 24-hr average,
SO yg/ro' annual geometric mean
of 24-hr averages.
Primary: lowest concentrations
attainable by reasonably avail-
able control methods, but not
to exceed concentrations set
forth as 'secondary standards."
Annual arithmetric average:
"More adverse":
Lower Limit Upper Limit Serious..
E3pg/m' 75 pg/mi 75 pg/m
daily average, once.per year:
140 tig/m-*160 pg/m 160 pg/m
2 /m,-,
dustfal1, mg/cm^/mo
0.35 0.50
No fugitive dust beyond property
line. Federal model for abatement,
except that no mention is made of
agricultural dust suppression or
paving of roads.
Airborne particulates at ground level
at property line may not equal 2.0 pg
par cubic meter, above background,
more than 10 min/hr.
No fugitive dust beyond property
line, plus Federal model, except (1)
no requirement that roads be paved,
and (2) agricultural operations can
create airborne dust if no nuisance
created. Secondary dust fall stan-
dard: 15 ton/mi2/month.
Dust fall: 20 tons/square mile/month
Coefficient of haze: 0.6 con/1000
lineal ft., annual geometric mean;
0.75 coh/1000 lineal ft., annual
arithmetric mean; 1.50 coh/1000
lineal ft., 24-hr, average. Abate-
ment by Federal model
Federal abatement model, except no
mention of agricultural operations.
0.50
(continued)
-------
TABLE 27. (continued)
Jurisdiction
Primary Standard
Secondary Standard
Fugitive Dust and Dustfall
Massachusetts
Federal
Federal
Michigan
Minnesota
Federal
Federal
Federal
Federal
to
^J
VO
Mississippi
Missouri
Federal
Federal
Montana
Federal
Federal
Reasonable precautions required.
Fugitive dust from process indus-
tries, from transport or handling of
materials, or from construction us*
and maintenance of roads may not
"contribute to a condition of air
pollution."
Treated as a nuisance. Area of cut
and fill open at one time is limited.
"Avoidable amounts" of dust must not
become airborne. Director may order
reasonable measures to be taken, in-
cluding paving and frequent cleaning
of roads, application of dust-free
surfaces, use of water, and mainte-
nance of vegetative ground cover.
Fugitive particulate matter must not
become airborne as a result of han-
dling, storage, or transport of any
material. Dust fall may not exceed
background levels by 5.25 grams/m^/
month on adjacent property.
Reasonable precautions required. No
fugitive dust or particles larger
than 40 microns permitted beyond
property line. Concentrations at
property line:
Suspended particulates
80 ug/m^ 6-month geometric mean
200 wg/m 2-hr arithmetic mean, for
no fpwer than 5 samples per year.
Reasonable precautions must be taken;
no "controllable" particulate matter
may be emitted. Specific measures
may be ordered by the Director.
(continued)
-------
TABLE 27. (continued)
Jurisdiction
Frlawry Standard
Secondary Standard
Fugitive Duck and Duetfall
Mebraaka
•evade
ro
O3
o
•en Jereey
•ew Mexico
R*v fork
raderal
Federal
Federal
Federal Secondary
Ambient air quality rnuat be hlqheat
achievable at present atate of the
•rt, but In no caee nay It be woree
than the Federal primary standard.
Federal
Federal
uq/m 74-hr averaqe
110 uq/i«j 7-day averaqe
90 wq/M. JO-day averaqe
•(0 wq/ai annual geometric Mean
State Include* four 'levela* froai
Level Ii apnrae population, to
Level IVi Metropolitan.
Short-tuna (all levela) averaqe 24-
hr concentration aha 11 not exceed
250 uq/m). Lonq termi durlnq 12
montha, SO percent of 24-hr con-
centration' aiay not exceed i -
Level 1 1 S% uq/n1 Level I til «5 pq/iaf
Level III tS wq/») Level IV i 75 liq/n
and »4 percent of 24-hr valuee aha 11
not exceed i .
Level lilt 100 M9/m
Level IV i 110 uq/m
Level It 4) M9>,
Level III IS wq/»
No vlalble
-------
TABLE 27. (continued)
Jurisdiction
North Caroline
Horth Dakota
ro
00
Ohio
Oklahon
Oregon
Pennsylvania
Primary Standard
Federal Secondary
Federal Secondary
Federal Secondary
Federal
Highest and best technology must be
applied. Standards measured at
'primary stations:" 60 ug/m3 annual
geometric meant 100 ug/m^ 24-hr con-
centration not to be exceeded by 15
percent of monthly samplest ISO
/n^ 24-hr concentration.
Federal
Secondary Standard
Federal
Federal
Fuqitive Oust and Oustfall
Asphalt plants must limit fugitive
dust to stack outlet. Roads must
be treated around plant. In road
construction, use of dust control on
haul roads and water sprays over
crushers for stone and aggregate
handling are required.
Dust fall: IS tons/ml /mo, maximum
3-month arithmetic mean in residen-
tial areas. 30 tons/miJ/tno, applies
to heavy industry areas. 0.4 co-
efficient of haze/1000 lineal feet.
maximum annual geometric mean. "Rea-
sonable precautions" plus Federal
mode 1.
Reasonable precautions plus Federal
model.
Reasonable precautions to control
fugitive dust are mandatory.
Abatement by Federal model, less
mention of agricultural operations
of paving roads. Stockpiles of
materials should be enclosed where
other means do not control dust.
Dust fall: annual average 0.8 mg/cn /
mo. 30-day average 1.5 mg/cm2/mo.
In all roadwork and land clearing
fugitive dust must be confined to
property, and not exceed ISO par-
ticles per cubic centimeter at
property line. Abatement by Federal
model, except no call for hoods,
fans), or covering of trucks.
(continued)
-------
TABLE 27. (continued)
Jurisdiction
to
00
to
Puerto Rico
Rhode Island
South
Carolina
South Dakota
Tennessee
Texas
Otah
Vermont
Primary Standard
Federal
Federal
60 wg/m annual geometric me*
SO ug/m3 24-hr average
250 ug/
Federal Secondary
Federal
Federal
Emissions from any source may not
exceedi
100 ug/m3 average over 5 hra.
200 ug/m3 average over 3 hra.
400 ug/m3- average over 1 hr.
Federal
45 ug/m? annual geometric average
125 ug/m dally average
Secondary Standard
Federal
Federal
Federal
Federal
Federal
Fugitive Dust and Dustfall
No fugitive dust in visible quan-
tities may be permitted to cross
property line. Abatement by Federal
model.
No emissions to air from handling.
transportation or storage of
materials. Abatement by reasonable
precautions during construction.
Dust control measures must be used on
premises and roads of mining, quar-
rying and other unenclosed opera-
tions.
Visible dust emissions may not pass
proper property line more than 5 min/
hr or 20 min/day. Abatement by
Federal model, first three paragraphs
only.
Materials-handling dust must be con-
trolled by use of water or chemicals,
use of hoods and fans, and covering
or wetting truck-bed loads. During
road construction, dust suppression
is required on all haul roads.
Reasonable precautions must be ex-
ercised In road construction activ-
ities.
(continued)
-------
TABLE 27. (continued)
Jurisdiction
K)
00
Ul
Virginia
Virgin
Islands
Washington
Wast Virginia
Wisconsin
Wy owing
Primary Standard
Federal, except In National Capital
Air Quality Control Region, where
Federal secondary standards must
be met.
Federal
Federal SecoMary
Federal
Federal
Federal Secondary
coh-0.4/1000 lineal ft. annual
geometric man
Secondary Standard
Federal
Federal
Federal
Federal
Fugitive Dust and Dustfall
Federal model, except control of
agricultural emissions are not re-
quired.
All reasonable measures. Including
watering and coating of roada, must
be used during road construction.
Reasonable precautions are required.
Abatement by Federal model.
Oust fall: 5 gm/m /mo for any 30-day
period in a residential area. 10 gn/
m2/mo for any 30-day period in an
industrial area. Abatement by
Federal model.
-------
APPENDIX C
TABLE 28
SYNOPSIS OF LAWS RELATIVE TO STATEWIDE POLLUTION ABATEMENT*
AIR
Alabama
A|r Pollution Control Act
Air Pollution Control Rules and Regulations
Alaska
Department of Environmental Conservation Act
Air Pollution Control Regulations
Arizona
Air Pollution Control Laws
Rules and Regulations for Air Pollution Control
Arkansas
Water and Air Pollution Control Act
Atr Pollution Control Code
California
Air Pollution Control Laws
Environmental Quality Act of 197O
Air Pollution Control Regulations
Motor Vehicle Emissions Regulations
Colorado
Air Po'.lution Control Act of 197O
WATER
Water Pollution Control Act
Water Quality Criteria
Procedural Regulations
Department of Environmental
Conservation Act
Water Quality Standards
Wastewater Disposal Regulations
Oil Pollution Regulations
Water Pollution Control Law
Rules and Regulations for Sewerage
Systems and Waste Treatment Works
Water Quality Standards
Water and Air Pollution Control Act
Regulations Establishing Water Quality
Standards for Surface Waters
State Water Resources Control Uoard
Water Pollution Control Law*
Water Regulations
Water Quality Control Act
SOLID WASTL - LAND USE
Solid Waste Disposal Act
Solid Waste Financing Act
Solid Waste Management Regulations
Standards for Disposal of Solid Wastes
Surface Mining Act of 1969
Department of Environmental Conservation Act
Solid Waste Management Regulations
Solid Waste Rules
Solid Waste Management Act
Solid Waste Disposal Regulations
Solid Waste Management and Resource Recovery
Act of 1972
Co as In 1 Zone Conservation Act
Solid Waste Disposal Sites and Facilities Law
K>
CO
• Mint. J.O.. in* J.C. HuUhlns. Crlurli for optioning pollution tbtumt
for (Mctln •ft* ibtMoMd mtnn. Sktllj ind toy (nglnxn «nd Contulunti. Mirrltburi
rtmiyl»»U. Pnptrttf for Offlc« of MUr «nd Hiiirdout NtMrlllt. U.S. CtMlroMnUI
rrouctln Agency, under contrwt 440/9-75-008. *uo,iiit 1975.
(continued)
-------
TABLE 28. (continued)
AIR
Colorado (continued)
Air Quality Control Regulations
Existing Wigwam Burners Regulations
Existing Alfalfa Dehydration Plants Regulations
Stationary Sources Standards
Hydrocarbons Vapors Regulations
Connecticut
Environmental Protection Act
Air Pollution Control Laws
Environmental Policy Act
Rules of Practice
Air Pollution Control Regulations
Delaware
Air Pollution Control Laws
Regulation I - Definitions and Administra-
tive Principles
Regulation II - Registration and Permits
Regulation III - Ambient Air Quality Standards
Regulation IV to VII and XVIII - Particulates
Regulations VIII and IX - Sulfur Dioxides
Regulation XIII - Open Burning
Regulation XIV - Visible Emissions
Regulation XV - Air Pollution Alert and
Emergency Plan
Regulation XVI - Sources Having an Interstate
Air Potential
Regulation XVII - Source Monitoring, Record-
Keeping and Reporting
Regulation XIX - Control of Odorous Air
Contaml nants
District of Columbia
Air Pollution Control Act
WATER
Regulations for State Discharge Permit
System
Water Quality Standards
Clean Water Act
Water Quality Standards
Underwater Lands Laws
Water Quality Standards
Water Pollution Control Regulations
River Dasin Commission Regulations -
Water Quality
Water Pollution Control Law
SOLID WASTE - LAND USE
Solid Waste Regulations
Solid Waste Management Act
Solid Waste Management Services Act
f?e*}u!ation on Disposal of Refuse
Public Utility Environmental Standards Act
Environmental Control Laws
Solid VMste Disposal Regulations
Coastal ?:ones Act
Wetlands Act
Solid Waste Law
00
Ul
(continued)
-------
TABLE 28. (continued)
AIR
District of Columbia (Continued)
Air Quality Control Regulations
Diesel Exhaust Emissions Regulations
Florida
Air and Water Pollution Control Act
Environmental Protection Act of 1971
Administrative Procedures
Air Pollution Rules
Rules on Permits
Open Burning and Frost Protection Fires
Regulations
Rules on Alternate Enforcement Procedure
Pollution Control Tax Assessment Rules
Georgia
Air Quality Control Law
Vehicular Visible Emission Control Act
Air Quality Control Rules
Hawaii
Environ mental Quality Law
Environmental Quality Council Law
Environmental Quality Commission Law
Air Pollution Regulations
Ambient Air Quality Standards
Idaho
Environmental Protection and Health Act
of 1972
Air Pollution Control Regulations
Illinois
Environmental Protection Act
WATER
Water Pollution Control Regulations
Air and Water Pollution Control Act
Sewage Disposal Facilities Law
Pollutant Spill Prevention and Control
Act
Water Resources Act of 1972
Rules on Pollution of Waters
Rules on Sewage Works
Rules on Assessment of Damacier,
Water Quality Control Act
WntEr Quality Control Regulations
Water Classifications
Environmental Quality Law
Water Pollution Control Regulations
Water Pollution Control Law
Water Quality Standards and Waste-
water Treatment Requirements
environmental Protection Act
SOLID WASTE - LAND USE
Sol id Waste Regulations
Resource Recovery and Management Act
Gartiage and Rubbish Rules
Environmental Land and Water Management Act
of 1972
Coastal Construction Law
Solid Waste Management Act.
Solid Waste Management Rules
Coastal Mnrchlands Protection Act
Environmental Quality Law
Solirl Waste Law
Solid Waste Regulations and Standards
Environmental Protection Act
00
(continued)
-------
TABLE 28. (continued)
AIR
SOLID
L'TIi - LAND USL~
Illinois (Continued)
General Air Pollution Regulations
Stationary Sources Standards
Air Quality Standards
Episodes Regulations
Open Hurning Regulations
Asbestos, Spray Insulation, and F
Regulations
Mobile Sources Standards
Odors Regulations
Water Pollution Control Rules
Pules and Regulations on c/.inides
Or Oynnorjon Compounds
Solid Wan to Regulations
K)
GO
Indiana
Air Pollution Control Law
Environmental Management Act
Environmental Policy Law
Open Burning, Visible Emissions, and Indirect
Heating Regulations
Process Operations, Existing Foundries, and
Incinerators Regulations
Episode Alert Levels
Sulfur Dioxide Regulations
Ambient Air Quality
Hydrocarbons Regulation
Regulations or* Carbon Monoxide and Nitrogen
Dioxide
Rarticulate Regulations Compliance Schedule
Permits Regulation
Fugitive Dust Regulation
Air Quality Basins Regulation
Stream Pollution Control Low
Phor.phate Ootergenl Law
Watercraft Sewmje Disposal Law
Water Quality Standards
NPUES Permit Regulations
Haznrdous Substances Rciulalton
Refuse Dnno^al Act
Anti-l^tfr Law
Hi'jHw-Ty ,(u»'kynrrl (. '"•ntrol Act
AtmncJo'ifc) Vehicle Act
S'">li<.t Waste* Mtin.iqenieft Permit
Intfustrial Waste Hnuk'r rjer-n^tt '-""
Iowa
Department of Environmental Quality Act
Rules and Regulations Relating to Air Pollution
Department of Environmental Quality Act
Water Quality Standards
Confined Feeding Operations Regulations
Uermr-tr-te'it of I- nvironmental Quality Act
5:ianiInry (Disposal t 'rojects Rules
Surface Mtmr*-} Law
(continued)
-------
TABLE 28. (continued)
AIR
WATER
SOLID WASTE - LAND USE
Kansas
Air Quality Control Act
Air Pollution Emission Control Regulations
Water Pollution Control Laws
Water Quality Criteria
Underground Storage Regulations
Permits, Spills, and Grants Regulations
Agricultural Wastes Regulations
Solid Waste Management Act of 197O
Solid Waste Disposal Act
Solid Waste Management Standards and
Regulations
fcO
00
Environmental Protection Law
General Provisions and Regulations
Open Burning Regulations
Particulate Emissions Regulations
Sulfur Compound Emissions Regulations
Hydrocarbon Emissions Regulations
Carbon Monoxide Regulations
Nitrogen Oxides Regulations
Coal Refuse Regulations
Ambient Air Quality Standards
Rules of Practice
Review of Indirect Sources
Environmental Protection Law
Water Quality Standards
Waste Discharge Permits Regulations
Public Hearings Regulations
Excessive Spills Discharges Regulations
Environmental Protection l_aw
Garbage and Refuse Disposal l_aw
Solid Waste Regulations
Strip Mining Law
Louisiana
Air Control Law
Council of Environmental Quality
Air Pollution Control Regulations
Stream Control Commission Acts
Regulation on Reports of Industrial
Waste Discharges
Rules Relating to Oil and Gas
Water Quality Criteria
Solid Wa'.iu Laws
Solid Waste Regulations
Maine
Air Pollution Control Law
Air Pollution Control Rules
Hearings Regulations
Water Pollution Control Law
Oil Discharge Prevention and
Pollution Control Act
Oil Pollution Control Regulations
Solid Waste Management Act
Solid Wnste Management Requisitions
Land Use Low
Site Location and Development Law
(Coastal Wetlands and Zoning Law
(continued)
-------
TABLE 28. (continued)
AIR
WATER
SOLID WASTE - LAND USE
Maryland
Air Quality Contf-ol Act
Environmental Policy Act
Alp Pollution Regulations
Water Pollution Control Laws
Water Resources Law
Environmental Service Act of 197O
Water Pollution Control Definitions
Water Pollution Control Regulations
Effluent Limitations
Regulation on Toxic Materials for
Aquatic Life Management
Oil Prevention Regulation
Discharge Permits'Regulatlon
Classification of State Waters
Wastewater Works Regulation
Water Pollution Control Principles
Receiving Water Quality Standards
Groundwater Quality Standards
Solid Waste Laws
Solirt Waste Regulations
Power Plant Siting Act
Strip Mining Law
to
oo
10
Massachusetts
Air Pollution Control Laws
Environmental Cause of Action Law
Environmental Protection.Law
Air Pollution Control Regulations
Air Quality Standards
Clean Waters Act
Rules for Adopting Administration Regu-
lations for the Conduct of Adjudicatury
Proceedings, and Administrative Rules
Rules for the Prevention and Control of
Oil Pollution In the Waters of the
Commonweal tn
Hazardous Waste Regulations
Water Quality Standards
Solid Waste Disposal Law
Sanitary Landfill Regulations
Air Pollution Laws
Envtronmental Protection Act of 197O
Administrative Rules for Air Pollution
Control
Water Resources Commission Act
Liquid Industrial Waste Disposal Act
Cleaning Agents and Water Conditioners
Act
Watercrart Pollution Control Act
General Provisions and Procedures Regu-
lations
Wastewater Reporting and Surveillance
Fees Rules
Solid Waste Disposal Act
Solid Waste Regulations
Shorelands Protection Act
(continued)
-------
TABLE 28. (continued)
AIR
WATER
SOLID WASTE - LAND USE
Michigan (Continued)
Hearings Regulations
Oil Spillage Regulations
Cleaning Agents Regulations
Wastewater Discharge Permits
Water Quality Standards
Water Temperature Standards
M
VO
O
Minnesota
Pollution Control Agency Law...
Environmental Council Act
Envi ronrnental Rights Act
Environmental Policy Act
Ambient Air Quality Standards
Air Quality Definitions
Permits and Monitoring Rules
Fuel Burning Rules
Particulate Matter Rules
Incinerator Rules
Open Burning Restrictions
Odor Control Rules
Visible Air Contaminants Rules
Gasoline Storage Rules
Acid and Alkaline Emissions Rules
Sulfuric Acid Plant Emissions Rules
Nitric Acid Rules
Emission Standards for Asbestos and
Inorganic Fibrous Material
Regulations for Permits for Indirect
Sources
Water Pollution Control Laws
Statutes Pertaining to Marine Tiolets
Oil Storage Regulations
Criteria for Intrastate Waters
Criteria for Interstate Waters
Effluent Standards for Intrastate
Waters
Classification of Intrastate Waters
Classification of Interstate Waters
NPDES Regulations
Criteria for watercrafl Sewage
Retention Devices
Solid wastes Recycling Law
Solid Waste Disposal Regulations
Critical Areas Act
Mississippi
Air and Water Pollution Control Act
Air Quality Regulations
Permit Regulations
Emergency Episodes Regulations
Air and Water Pollution Control Act
water Quality Criteria
NI'PES Regulations
Solid War.te Oispos.il Act of 1974
Solid Wa-Me f-Je.julntions
Sanitary Landfill Standards
(continued)
-------
TABLE 28. (continued)
AIR
Missouri
Air Conservations Law
Regulation 3-1, Auto Exhaust Emission Con-
trols
Regulation S-ll, Reporting of New Installations
Regulation S-lll, Open Burning Restriction;-,
Regulation S-IV, Incinerators
Regulation S-V, Restriction or Emission of
Particulate Matter from Industrial Processes
Regulation S-VI. Maximum Allowable Emissions
of Particulate Matter from Fuel-Burning
Eoulpment Used for Indirect Heating
Regulation S-VII, Restriction of Particulate
Matter from Becoming Airborne
Regulation S-VIII, Restriction of Visible Air
Contaminants
Regulation S-IXf Restriction of Emission of
Odors
Regulation S-Xf Restriction of Ernission of
Sulfur Compounds
Regulation S-XI, Rules for Controlling Emissions
During Periods of High Air Pollution Potential
Montana
Clean Air Act
Air-Quality Regulations
Nebraska
Environmental Protection Act
WAT LR
Clean Water Law
Waste Disposal Well Lav/
Definition Regulation
Discharge and NPDES Permits ,-vvl
Spills Regulations
Effluent Regulations
Miscellaneous Water Pollution Control
Regulations
Water Pollution Control Law
Water use Act
Environmental Policy Act
Water Quality Criteria
Regulation on Water Pollution from
Livestock F~eedinq
Pollutant Discharge Elimination
System
Environmental Protection Act
'-•OLID VVASTL - L/M-ID U'M-D
County Option Dur-npir->g Groun'J L-iw
JunkynrcJs L.1W
Solid WnrUe Low
l-'efi.r;e Disposal Regulations
S-jli'l'Wa-iU- Muleo an-i Regulations
. Refuse Disposal C.ont'rol Law
Refuse Disposal Districts Law
Refuse Disposal Regulation
f^nvironn->ent,-ll ProttJCtinn Act
to
vo
(continued)
-------
TABLE 28. (continued)
AIR
WATER
t.OLID WAST E - LAND USE
Nebraska (Continued)
Motor and Diesel-Powered Motor Vehicle Acl
Rules of Practice and Procedure
Air Pollution Control Regulations
Water Quality Standards
Domestic anil Industrial Liquid Wastes
Disposal Mules
Livestock Waste Control Regulations
Disposal Wells Regulations
MPDES Regulations
Solid Waste Disposal Sites Law
Solid Waste Control Rules
Air Pollution Control Law
Air Quality Regulations
Water Pollution Control Laws
Water Pollution Control Regulations
Solid Waste Disposal Law
Solid Waste Management Regulations
to
ID
New Marnpshire
Air Pollution Control Law
Open Burning Regulations
Fluorides Regulation
Particulate Emissions Regulations
Sulfur Emissions Regulations
Incinerators Regulation
Waste Burners Regulation
Asphalt Plants Emissions Regulation
Motor Vehicles Regulation
Ferrous Foundries Regulation
Ambient Air Quality Standards
Sand, Gravel, and Cement Industries
Regulation
Nonferrous Foundries Regulation
Pulp and Paper Industry Regulation
Permit Regulation
Process, Manufacturing, Service, Miscel-
laneous Industries Regulation
Record Keeping Regulation
Emergency Episode Regulation
Requirements for Indirect Sources
Water Pollution Control L.TW
Waste Disposal Laws
Junkyard Control Law
(continued)
-------
TABLE 28. (continued)
AIR
WATER
SOLID WASTE - LAND USE
10
\D
U)
New Jersey
Department of Environmental Protection Act
of 1970
Air Pollution Control Laws
Regulations on General Provisions and Open
Burning
Regulations on Smoke from Combustion of Fuel
Regulations on Air Pollution from Manufacturing
Processes
Regulations on Sulfur
Regulations on Permits and Certificates
Regulations on Incinerators
Regulations on Emergencies
Ambient Air Quality Standards
Regulations on Diesel-Powered Motor vehicles
Light-Duty Motor Vehicles Regulations
Department of Environmental Pro-
tection Act of 197O
Water Pollution Control Laws
Water Quality Improvement Act of 1971
Clean Ocean Act
Wetlands Act of 1970
Environmental Rights Act
Point Source Discharge Regulations
Surface Water Quality Standards
Solid Waste Laws
Motor vehicle Junk Law
Waste Control Act
Solid Waste Management Regulations
Coastal Area Facility Review Act
New Mexico
Environmental Improvement Act
Air Quality Control Act
Air Quality Standards and Regulations
Water Quality Act
Water Quality Regulations
Water Quality Standards
Solid Waste Management Regulations
New York
Environmental Conservation Law
Rules on General Provisions, Permits Stack
Testing, Emergency Control Measures, and
General Prohibition
Processes and Exhaust and/or Ventilation
Systems
Contaminant Emissions from Ferrous Jotting
Foundries and Dy-Product Coke Batteries
Rules on Open Fires
Rules on Motor Vehicle Emissions
Incinerator Rules
Rules on Cement Plants and Asbestos
Environmental Conservation Law
Watercraft Sewage Disposal Law
Classifications and Standards
Criteria Governing Thermal Discharges
Rules on Use and Protection of Waters
Environmental Conservation Law
Refuse Disposal Rules
Wetlands Law
(continued)
-------
TABLE 28. (continued)
AIR
WATER
SOLID WASTE - LAND USE
New York (Continued)
Rules on Fuel Composition and Use
Rules on Sulfurlc Acid and Nitric Acid Plants
Rules on Indirect Sources of Air Contamination
Ambient Air Quality Standards
North Carolina
Water and Air Resources Acts
Motor Vehicle Emissions Laws
Rules and Regulations Governing the Control
of Air Pollution
Water and Air Resources Acts
Environmental Policy Act of 1971
Oil Pollution Control Act of 1973
Rules, Regulations, Classifications
and Water Quality Standards Applicable
to Surface Waters
Monitoring Regulation
Solid Waste Disposal Law
Solid Waste Disposal Regulations
K>
VO
North Dakota
Air Pollution Control Act
Air Pollution Control Regulations
Water Pollution Control Act
Surface Water Quality Standards
Solid Waste Management Regulations
Ohio
Air Pollution Control Laws
General Air Pollution Regulations
Regulations for Suspended Particulates and
Sulfur Oxides
Regulations for Carbon Monoxide, Hydro-
carbons, and Photo-chemical Oxidant2
Regulations for Oxides of Nitrogen
Permits System Regulations
Regulations for the Prevention of Air Pollution
Emergency Episodes
Permit Fees Regulations
Regulation on Air Permits to Operate and
Variances
Open Burning Regulation
Environmental Protection Agency
Water Pollution Control Act
Watencraft Sewage Disposal Law
Criteria of Stream-Water Quality
Resolution on Discharge of Toxins
NPDES Permit Regulations
Ohio River Valley Water Sanitation
Commission Standards on Sewage
and Industrial Wastes
Solid Waste Disposal Law
Solid Waste Disposal Regulations
Power Plant Sitincj Commission Law
Reclamation l_aw
(continued)
-------
TABLE 28. (continued)
AIR
Oklahoma
Clean Air Act
Pollution Control Coordinating Act of 1968
Regulation 1 - Open Burning
Regulation 2 - Motor Vehicle Pollution Control
Devices
Regulation 3 - Definitions
Regulation 4 - Air Contaminant Sources Regis-
tration
Regulation 5 - Incinerators
Regulation 6 - Particulate Matter Emission
front Fuel-Burning Equipment
Regulations 7, 8, 9, 19 - Smoke, Particulates,
Hazardous Contaminants
Regulations 11, 12, 13- Malfunction, Sampling,
and Monitoring
Regulation 14 - Permits
Regulation 15 - Organic Material
Regulation 16 - Sulfur Oxides
Regulations 17, 18 - Carbon Monoxide and Nitro-
gen Oxides
Air Pollution Control Laws
Air Pollution Control Regulations
Pennsylvania
Air Pollution Control Act
Air Pollution General Rules
Standards for Contaminants
Coal Refuse Disposal Rules
Air Pollution Sources Rules
Standards for Sources
Ambient Air Quality Standards
WATCH
Water Pollution Control Laws
Pollution Remedies Laws
Pollution Control Coordinating Act
of 1908
Water Pollution Control Laws
Synthetic Cleaning Agent Act
Water Quality Control Regulations
Department of Environmental Resources
Clean Streams Law
Sewage Facilities Act
Sewage Facilities Regulations
Water Quality Criteria
Water Resources General Provisions
NPDES Permit Regulations
•jULIU WAST (I - LAND USE!
Solid Waste Management Act
Pollution Control Coordinating Act of 1968
Solid Waste Management Regulations
Solid Waste Management Law
Solid Waste Regulations
Land Use Law
Solid Waste Management Act
Solid Waste Regulations
Surface Mining Conservation and Reclamation Act
IZrosion Cor-tro! Regulations
NJ
VO
(continunrl)
-------
TABLE 28. (continued)
AIR
Pennsylvania (Continued)
Local Air Pollution Control Agencies Rules
Sources Reporting Rules
Air Pollution Episodes Rules
Sampling-Testing Rules
Variances and Alternate Standards
Puerto Rico
Department of Natural Resources Act
Law on the Control of Air Pollution
Air Pollution Control Regulations
Rhode Island
Clean Air Act
Air Pollution Control Regulations
Sulfur Content of Fuels Regulation
Approval of Plans Regulation
Air Pollution Episode Regulations
Nitrogen Oxides Regulation
Incinerator Regulation
South Carolina
Pollution Control Acts
Air Pollution Control Regulations and
S tandards
South Dakota
Clean Air Act
Air Pollution Control Regulations
WATER
Waste Water Treatment Regulations
Industrial Wastes Regulations
Mine Drainage Permits
Sewage Facilities Grants
Water Pollution Control Law
Harmful Spills Law
Public Policy Environmental Act
Water Pollution Control Law
Water Quality Standards
Pollution Control Acts
Classification Standards
Water Pollution Law
Environmental Policy Act
Water Quality Standards
SOLID WASTE - L/\ND USE
(ISIONE)
Solid Waste Law
Coastal Resources Management Council
Solid Waste Management Corporation Act
Landfill Regulation
Industrial Solid Waste Disposal Site Regulation
Guidelines for Waste Disposal Permits
Sol id Waste Disposal Act
Solid Wnste Rules
(continued)
-------
TABLE 28. (continued)
AIR
Tennessee
Atr Quality Act
Air Pollution Control Regulations
Texas
Clean Air Act
Air Control Board Regulations: General
Provisions
Regulation 1: Control of Air from Smoke,
Visible Emissions, and Partlculate Matter
Regulation III; Control of Air Pollution from
Toxic Materials
Regulation IV: Control of Air Pollution from
Motor Vehicles
Regulation V: Control of Air Pollution from
Volatile Carbon Compounds
Regulation VI: Control of Air Pollution by
Permits for New Construction or Modification
Regulation VII : Control of Air Pollution from
Nitrogen
Regulation VIII: Control of Air Pollution
Emergency Episodes
Regulation ||: Control of Air Pollution from
Sulfur Compounds
Exemptions from Permits Procedures
Permit System Procedures
Utah
Air Conservation Act
Air Conservation Regulations
Vermont
Atr Pollution Control Law
WATER
Stream Pollution Control Law
General Regulations
Water Quality Criteria
Water Quality Act
Water Quality Reouirements , General
Statement
Water Quality Rules
Water Quality Standards
Water Pollution Control Act
Definitions and General Requirements
Water Quality Standards
Water Pollution Control Laws
SOLID WASTE - LAND USE
Solid Waste Disposal Act
Solid Waste Regulations
Surface Mining Law
Solid Waste Disposal Act
Refuse Dumping Law
Solid Waste Regulations
Regulation on Disposal of Industrial Solid Waste
. .
Solid Waste Disposal Regulations
Solid Waste Law
to
(continued)
-------
TABLE 28. (continued)
AIR
WATER
SQUID WASTE- LAND USE
Vermont (Continued)
Air Pollution Control Regulations
Water Classification and Quality
Regulations
Pollution Charges and Permit Fees Pules
NPDE5 Permit Program Regulations
Solid Waste Regulations
Land Use Law
Land Capability and Development Plan Law
N>
to
CD
Air Pollution Control Laws
Council on the Environment Law
Air Pollution Control DeflrUttons
Air Pollution Control Procedures
Air Quality Standards
Regulations on Open Burning, Smoke,
and Visible Emissions
Partlculates Regulations
Gaseous Contaminants Regulation
Odor Regulations
Coal Refuse Disposal Regulation
Motor vehicle Emissions Regulation
Air Pollution Emergency Regulation
State Water Control Law
Miscellaneous Laws Relating to Water
Pollution
Environmental Impact Report Law
Water Pollution Control Regulations
Water Quality Standards
Solid Waste Disposal Law
Solid Waste Regulations
Washington
Environmental Quality Reorganization Act
of 197O
Clean Air Act
State Environmental Policy Act of 1971
General Air Pollution Regulations
Emergency Episode Plan
Open Burning Regulations
Field Burning Regulations
Regulations on State Financial Aid
Regulations on Reporting by Thermal Power
Plants, Aluminum Plants, and Chemical Wood
Wood Pulp Mills
Regulations on Motor Vehicles
Carbon Monoxide Standards
Water Pollution Qontrol Laws
Environmental Coordination Procedures
Act of 1973
Department of Ecology Organization
Waste Works Regulations
Wastes Discharge Permits
Water Pollution Control Planning
Regulations
Hearings Regulations
NPDES Permit Program Regulations
Water Quality Standards
Solid waste Management Law
Shoreline Management Act of 1971
Thermal Power Plant Siting Law
Shoreline Development Permit Regulations
(continued)
-------
TABLE 28. (continued)
AIR
WAT EK
SOLID WASTE - LAND USE
Washington (Continued)
Regulations on Kraft Pulping Mills
Sulflte Pulping Mills Regulations
Suspended Particulate Standards
Particle Fallout Regulations
Protochemlcals f Hydrocarbons, Nitrogen
Dioxide Regulations
Fluoride Standards
Regulations on Primary Aluminum Plants
Sulfur Oxide Standards
Procedures Regulations
Ecological Commission Regulations
K)
VO
VO
West Virginia
Air Pollution Control Law
Regulations on Coal Refuse Disposal
Regulations on Combustion of Fuel in
Indirect Heat Exchangers
Regulations on Hot Mix Asphalt Plants
Regulations on Odors
Regulations on Coal Preparation Plants
Regulations on Combustion of Refuse
Regulations on Manufacturing Process Operations
Ambient Air Quality Standards
Regulations on Sulfur Oxides
Regulations on Emergency Episodes
Regulations on Permits
Water Pollution Control Act
Water Quality Regulations
Solid Waste Laws
Solid Wa<;te Regulation
Surface Mining Act
Wisconsin
Atr Pollution Control Laws
Environmental Impact Law
Ambient Air Quality Standards
Air Pollution Control Rules
Water Pollution Control Law
Discharge Permits Regulations
Public Participation Procedures
Interim Effluent Limitations for
Pollution Discharge Elimination
System
Water Quality Standards
Solid Waste Law
Environmental Quality Act
Environmental Quality Act
Air Quality Standards and Regulations
Protection of Public Water Supply Act
Environmental Quality Act
NPDES Permit Program Regulations
Water Quality Standards
Solid Waste Disposal Law
Solid Waste Management Rules
-------
APPENDIX D
EXPLANATION OF CRITERIA USED TO ESTABLISH
RANKING OF INDIVIDUAL MINERAL INDUSTRY BY
SEVERITY OF ENVIRONMENTAL IMPACT
The criteria are arranged according to their relative
importance in the overall environmental impact from mineral
resource wastes (Table 26). Values assigned to these criteria
and the individual mineral industries are, of necessity,
judgmentally arbitrary and are intended only as a rough means of
putting the problems associated with the individual mineral
industry into perspective. The generation of hazardous waste by
any industry is the primary criterion because such wastes pose a
threat (lethal or sublethal) to the environment if they are not
controlled. The generation of nonhazardous wastes is another
less important criterion. The disposal of these wastes in
environmentally sensitive areas is the primary concern in this
criterion. Values applied to the potential impacts from
hazardous wastes are intentionally given a weighted score higher
than the scores used to measure the potential impact from
nonhazardous wastes. :
The other three criteria account for the impact of the size
of the mineral industries in terms of annual production of mineral
resource wastes, total number of mines, and the projected growth
of the industry.
300
-------
GLOSSARY
acid igneous deposits
bedrock
bench
benzo(a)pyrene
borrow pit
cobble
continuous mining
control technology or
methods
crude ore
A natural formation of pyrite
containing rock formed by the
solidification of molten material.
Any solid rock exposed at the
surface of the earth or overlain by
unconsolidated material.
A ledge that forms a single level
of operation above which mineral or
waste materials are excavated from
a contiguous bank or bench face. A
working road or base below a highwall
as in contour mining or one of the
concentric ledges of an open pit
mine.
A ubiquitous polynuclear aromatic
hydrocarbon that is carcinogenic.
A surface excavation utilized to
obtain local construction materials
(sand, gravel, rock, etc.) or fill
material; usually consists of a
relatively small pit and waste
pile.
A rock fragment, usually rounded or
semirounded, having an average
diameter of from 3 to 12 inches.
An underground mining method in
which a machine (continuous miner)
cuts or rips coal from the face and
loads it in a continuous operation,
thus eliminating drilling and
shooting. The machine progressively
moves forward as the coal is removed.
The systematic handling of mine solid
waste according to sound principles
and practices to mitigate adverse
environmental impacts.
The unconcentrated ore as it leaves
the mine. It includes both mineral
commodity and waste, which are
separated during beneficiation.
301
-------
deposit
disposal
highwall
ore
ore complex
overburden
porphyry
pyrite
raise
A natural occurrence of a mineral
in sufficient extent and
concentration to allow economical
extraction and recovery.
The placement of mining or processing
wastes in a selected area or its
confinement.
The unexcavated face of exposed
overburden and coal or ore bordering
one side of an area strip mine or the
bank on the uphill side of a contour
strip mine excavation.
A natural compound of the elements
of which at least one is a metal.
A mineral of sufficient value as to
quality and quantity which may be
mined with profit. Less commonly,
materials mined and worked for
nonmetals.
An ore that contains two or more
recoverable minerals, such as
lead-zinc-silver ores and gold-silver
ores.
Material of any nature, consolidated
or unconsolidated, that overlies a
deposit. Also used to designate only
loose soil, sand, gravel, etc. that
lies above the bedrock. Also called
burden, cover, drift, capping, and
mantle.
Any igneous rock with a porphyritic
(distinct crystals in a fine-grained
ground mass) texture.
A term applied to any of a number of
metallic-looking sulfides, of which
iron sulfides are the most common.
The oxidation of pyrites is the
predominant source of acid mine
damage.
A verticle or inclined opening driven
upward from an underground mining
operation.
302
-------
reclamation
skip
solid waste
stabilization
stope
stoping
submarginal
The return of mined land to a
condition and/or use equal to or
higher than that prior to mining.
A hoisting bucket that slides
between guides in a shaft
(skip shaft) and is used to raise
and lower men and equipment or ore.
Any discarded material, including
solid, liquid, semisolid, or
contained gaseous material,
resulting from mining operations.
Does not include discharges that
are point sources subject to permits
under Section 402 of the Federal
Water Pollution Control Act or
source, special nuclear, or
by-product material as defined in
the Atomic Energy Act of 1954, as
amended.
Activities conducted on mined land
or mine or beneficiation waste to
lessen adverse environmental impacts
(such as leaching and fugitive
emissions) and prepare the area for
further reclamation. These
activities include redistribution
of materials, grading, providing
drainage and/or surface water
diversion, and the application of
chemicals or water for dust
suppression.
An excavation in an underground mine,
other than development workings, made
for the purpose of extracting ore.
The excavation of an ore, either above
or below a level, in a series of
horizontal, vertical, or inclined
workings in veins or large irregular
ore bodies or in rooms (in flat
deposits).
Refers to an ore deposit or mineral
resource that would require a
substantially higher price or a major
cost-reducing advantage in technology
for the mineral to be economically
recovered.
303
-------
tailings The waste or gangue material removed
from crude ore by beneficiating
operations. Tailings may be wet
or dry depending on the type of
beneficiation and the method of
disposal. Flotation and washing
are the major sources of tailings
at most operations.
waste rock Barren or submarginal rock or ore
that has been mined but is not of
sufficient value to warrant treatment
and is therefore removed ahead of
beneficiation.
304
------- |