EPA-670/2-74-093
October 1974
Environmental Protection Technology Series
ENVIRONMENTAL PROTECTION IN
SURFACE MINING OF COAL
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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EPA-670/2-74-093
October 1974
ENVIRONMENTAL PROTECTION
IN
SURFACE MINING OF COAL
By
Elmore C. Grim
and
Ronald D- Hill
Mining Pollution Control Branch (Cincinnati, Ohio)
Industrial Waste Treatment Research Laboratory
Edison, New Jersey 08817
Program Element No. 1BB040
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF.RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI. OHIO 45268
For sale by the Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402
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EPA REVIEW NOTICE
This report has been reviewed by the
National Environmental Research Center,
Cincinnati, and approved for publication.
Mention of trade names or commerical pro-
ducts does not constitute endorsement or
recommendation for use.
ii
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FOREWORD
Man and his environment must be protected from the
adverse effects of pesticides, radiation, noise and other
forms of pollution, and the unwise management of solid waste.
Efforts to protect the environment require a focus that re-
cognizes the interplay "between the components of our physical
environment — air, water, and land. The National Environ-
mental Research Centers provide this multidisciplinary focus
through programs engaged in
• studies on the effects of environmental
contaminants on man and the biosphere, and
• a search for ways to prevent contamination
and to recycle valuable resources.
The problem of environmental degradation caused by sur-
face mining and mineral processing is widespread and serious.
Minerals in some form occur in each of the fifty states and
several states are extensively mined. Mineral recovery is an
extractive industry, by its very nature it involves a dis-
ruptive process. This report discusses damages caused by
surface mining (with emphasis on coal), outlines techniques
that will hold damages to a minimum, discusses procedures to
restore the land after mining has occurred, and highlights
areas requiring further research and development.
A.W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
iii
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ABSTRACT
This report is the result of information obtained from a review
of related literature and assembled by personal inquiry and on-
site examination of both active and inactive surface mining
operations.
Premining planning is emphasized and particular attention is
given to incorporating mined-land reclamation into the mining
method "before disturbance. Strip and auger mining methods ,
as well as equipment, are described and evaluated. New mining
methods that will maximize aesthetics and minimize erosion,
landslides, deterioration of water quality are discussed.
Blasting techniques and vibration damage controls are re-
commended. Methods of land reclamation including spoil segre-
gation, placement, topsoiling, grading, burying of toxic
materials, and revegetatlon are noted.
Technology for the control of erosion and sediment in the mining
area is presented in detail. Poorly designed and abandoned
coal-haul roads cause excessive sedimentation of receiving
streams. Guidelines for planning, location, construction,
drainage, maintenance, and abandonment of coal-haul roads are
included.
Costs are given for different degrees of reclamation and
remedial measures for controlling pollution from surface mines.
Reduction in costs through premining planning are cited.
Water quality change is discussed in detail, with emphasis on
acidity formed from exposed pyritic material and on increase
in dissolved solids. Preventive and treatment measures are
recommended.
Research needs are listed as a separate section of the manual.
Extensive referencing is used throughout the text and appear
at the end of each section.
iv
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CONTENTS
Foreword
Abstract.
iii
iv
list of Figures vii
List of Tables xii
Acknowledgments , xiv
Section
I Conclusions 1
II Introduction ^
III Premining Planning IT
IV Surface Mining Methods, Techniques, and Equipment 28
V Blasting 92
VI Sediment and Erosion Control 1Q1
VII Coal-Haul Roads , ll6
VIII Reclamation Costs
IX Backfilling, Grading and Revegetation
X Acid Mine Drainage
XI Research, Development, and Demonstration Heeds
XII Glossary
XIII Appendix
A-l. Summary of State Laws Governing Surface Mining.
A-2. Slope Restrictions.in Strip Mine Laws
B. Excavated Sediment Ponds
C.
Engineering Standard for Debris Basin
for Control of Sediment
239
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CONTENTS (Continued)
D. Guidelines for the Contruction of Mine Roads ........... 255
E. Section 5 , Haulageways (Excerpt ) , West Virginia ........ 26°
F. Project Cost by Agencies ...............................
G . Current Grading Requirements , Kentucky ................. 2°T
H. Treatment of Ponds and Pits Filled with Acid
Mine Drainage ......... .................................
I . Units of Measurement
vi
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FIGURES
Ho. Page
1 Aerial View of Area Mining 5
2 Contour Mining in Appalachia 6
3 Bituminous and SubMtuminous Coal and Lignite Fields
of the Conterminous United States 10
U Coalfields of Alaska 11
5 Comparison of Coal Ranks by Heat Values 1^
6 Highwall Sampling 18
7 Permit Application Map, Pleasant District, Preston County,
West Virginia. September 17, 1973 19
8 Esro-lnch Test Core 23
9 Acid Base Account 25
10 Area Strip Mining in the Midwest 29
11 Area Strip Mining with Concurrent Reclamation 30
12 Plan and Section Views of a Bucyrus-Erie 1950-B Pit 33
13 Shovel in an Operating Pit 3k
Ik Pit Layout at Bucyrus-Erie l£50-W Operation 35
15 Dragline in an Operating Pit 36
l6 Pit Layout at a Shovel and Bucket Wheel Excavator Tandem
Operation in Illinois 37
17 Shovel and Bucket Wheel Excavator in Tandem Operation 38
18 Plan and Section Views of a Dragline and Bucket Wheel
Excavator in Tandem Operation 39
vii
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NQ. Page.
19 Dozer-Scraper Operation in Wyoming UO
20 Plan View of a Wyoming Open Pit Coal Mine Ul
21 Plan and Section Views of a Multiple Seam Scraper Operation k2
22 Multiseam Stripping Operation with a Shovel U3
, ,-j ..T'/P. - •>- i •
23 Multiseam Stripping Operation with a Dragline .. U5
2k Dragline Exposing Lowest Seam from Leveled Spoil 1*6
25 Shovel-Dragline Tandem Operation for Multiseam Mining kl
26 Various Stages of Strip Mining and Reclamation 1*8
27 Contour Strip Mining in Eastern Kentucky 50
28 Contour Strip Mining 51
29 Conventional Contour Mining 52
30 Landslides Caused by Overloading the Fill Bench 53
31 Slope Reduction Method, Steps 1 and 2 56
32 Slope Reduction Method, Step 3 57
33 Slope Reduction Method, Steps 1 and 2, One Cut Only 57
3k Slope Reduction Method, Outslope Terraced and Revegetated 58
35 Parallel Fill Method, Modified Slope Reduction, Steps 1 and 2 ... 59
36 Parallel Fill Method, Modified Slope Reduction, Step 3 60
37 Box-Cut Method (Two Cut), Steps 1 and 2 62
38 Box-Cut Method (Two-Cut), Steps 3 and k 63
39 Box-Cut Method (Two-Cut), Step 2 6k
kO a-UOb Head-of-Hollow Fill ••••.• 65466
Ul Multiple Seam Mining Method: Two Seams More Than 25 Feet Apart in
the Same Highwall •« 67
k2 Multiple Seam Mining Method: Two Seams -Less Than 25 Feet Apart in
the Same Highwall, Steps 1 and 2. 68
viii
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Ho. Page
^3 Mountain-Top Eemoval Method: Mountain Top After Final
Grading and Topsoiling ......................................... 69
kk Mountain-Top Removal Method: First Cut (Box Cut ) .............. TO
U5 Mountain-Top Removal Method: Second Cut ....................... 71
U6 Mountain-Top Removal Method: Fourth Cut ....................... 71
U7a-^7b Mountain-Top Removal Method: Mountain Top After Final
Grading and Topsoiling = ........................................ 72&73
U8 Block-Cut Method .............................................. 75
1*9 Block-Cut Method: Stripping Phase ...................... . ....... j6
50 Block-Cut Method: Backfilling Phase ........................... 76
51 Block-Cut Method: Controlled Placement of Spoil, Steps 1,2,
and 3 ............................... .......................... 79
52 Block-Cut Method: Controlled Placement of Spoil, Steps k,
5, and 6 [[[ 80
53 Block-Cut Mining in West Virginia .............................. 8l
5U Auger Mining Following Strip Mining ..... ; ...................... 82
55 Auger Hole Section and Spacing ................................. 83
56 Plan of Auger Holes Drilled in the Coal Seam from a
Curving Highwall ................ . .............................. 8U
57 Various Types of Terrain Applicable to the Longwall
Stripping System ...... • ....................................... 85
58 Proposed Blasting Plan (Example ) ............................... 97
59 Drill Holes Laid Out According to Blasting Plan and Ready
for Loading ............................................. ....... 98
60 Earth Embankment Sediment Control Basin ........................
6l Gabions Used as a Sediment Control Structure ................... 105
62 Typical Section of Rock-French Drain Sediment Control
Basin (Leaky Dam Type ) ......................................... 109
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No. Page
6k Grassed Waterway ........... , .....................................
65 Waterway Lined With Half-Round, Bituminized Fiber Pipe ...........
66 Diversion Ditch at Top of Highwall ............................... I12
67 Reduced Highwall , Mulched to Minimize Erosion .......... J: . .'. .'." ---- H3
68 Abandoned Coal Haul Road, No Attempt Made to Bed it Down ......... 117
69 Properly Constructed and Maintained Coal Haul Road ............... 120
70 Long, Uninterrupted Slope Showing Erosion After One Storm ........ 151
71 Diagram of Common Backfilling Practice (Cover the Pit) ........... 155
72 Common Backfilling Practice (Cover the Pit ) ...................... 156
73 Diagram of Typical Contour Backfill .............................. 157
71* Typical Contour Backfill ......................................... 158
75 Diagram of Typical Terrace Backfill .............................. 159
76 Diagram of Typical Pasture Backfill (Reduce Highwall if
Fractured) [[[
77 Typical Pasture Backfill (Reduce Highwall if Fractured)
78 Diagram of Typical Georgia V Ditch (Swallow-Tail) backfill,
(Reduce Highwall , if Fractured) .................................. l62
79 Strike-Off Grading: First Generation of Grading
(Area Strip Mining ) .............................................
80 Backfilling and Grading to the Approximate Original Contour
(Area Strip Mining) .............................................. 165
81 Gouging to Retard Surface Runoff and Increase Infiltration
into the Spoil [[[ 167
82 Removing Topsoil Before Stripping „ .............................. 169
83 Aerial Seeding by Helicopter (Contour Mining) .................... l8U
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Ho. Page
86 typical Treatment Plant 201
87 Simple Lime Reagent Feeder 202
88 Commercial Lime Treatment Plant 2Ql*
89 Treatment of AMD with Soda Ash Briquettes 2°6
90 Chemical Feeder for Treating Mine Drainage
xi
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TABLES
No. Page
1 Status of Land Disturbed by Surface Mining in the
United States as of January 1, 197** > "by State (Acres ) ........... f
2 State-Enacted Surface Mining Lavs . ............................. °
3 Coal Reserves of the United States , by State .............. ...... 12
** Estimated Strippable Reserves of Coal and Lignite in the
United States , January 1, 1968, by State ....................... 13
5 United States Production of Bituminous and Lignite Coal at
Deep and Surface Mines , 19^0-72 ................................. ^
6 Slope Reduction (Example ) ...................................... 58
7 Maximum Explosive Charges Using Scaled Distance
Formula W = (D/50 )2 ............................................. 96
8 Summary of Reclamation Costs : Commonwealth of Pennsylvania .....
9 Summary of Reclamation Costs: Commonwealth of Kentucky,
States of Ohio and West Virginia ............................... 12°
10 Summary of Costs : Mine Reclamation Control Measures
10A Reclamation Costs: EPA, Dents Run Project
Bridgeport, West Virginia ................ ...................... 129
11 Cost of Reclaiming Land Disturbed by Strip and Surface
Mining in the United States in 196^ ............................. 13°
12 Strip Mine Reclamation Projects: Variables Affecting
Backfilling and Grading Costs ................................... 132
13 Estimated Average Production Costs ............................. 13**
Ik Approximate Reclamation Costs Per Ton of Coal Mined
by Stripping [[[ 135
15 Reclamation Costs Per Acre for Kansas Mined Land
Demonstration Sites , 1973 ....................................... 137
16 Cubic Yards of Overburden to be Moved Per Acre .................. 138
17 Cost Per Cubic Yard of Material Moved . . ......................... 139
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TABLES (continued)
No.
19 Number of Strip Mines, Production, Output Per Man Day,
Average Seam Thickness , Average Overburden and Average
Value in 196? by State
20 ..... Comparison of Two Strip Mines, 1958 Vs 1973,
(Production 2 m tpd)
21 Summary of Physical Data Used in Cost Analyses
22 Summary of Cost Analyses
23 Percentage Breakdown of Costs, 1969, Seven Strip-Coal
Mines ......... *
2k Estimated Per-Ton Production Costs for 5 ,000 ,000 - tpy
Strip-Coal Mine ...............................
25 Mine Spoils Classified According to Stoniness .................. 152
26 Typical Composition of Bituminous Coal (Fort Martin)
Fly Ash Used at Stewartstown Study Site .......................
27 Reclamation Costs of Surface-Mined Spoil (Stewartstown)
28 Analysis"of Lagooned, Digested Sludge from the
Metropolitan District of Greater Chicago
29 Mine Spoils Classified According to Reaction Classes lo°
xiii
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ACKNOWLEDGMENTS
The assistance and cooperation of all the various Federal and
State agencies is gratefully acknowledged.
Special thanks are extended to the following people for their
support and guidance during the period of document preparation:
Thomas P. Flynn Jr., U.S.Dept. Interior, Bureau of Mines,
Division of Environment, Washington, D. C.; John P. Capp, U.S.
Dept. Interior, Bureau of Mines, Morgantown, West Virginia;
Grant Davis, U.S. Dept. Agriculture, Forest Service,
Berea, Kentucky; Oscar W. Albrecht, Kenneth G. Dotson, Dale
W. Dietrich, National Environmental Research Center, Cincinnati,
Ohio; Benjamin C. Greene, Dept. Natural Resources, Division
of Reclamation, Charleston, West Virginia; John Buscavage,
Dept. Environmental Resources, Harrisburg, Pennsylvania;
Ernest J. Gebhart, Dept. Natural Resources, Division of
Forestry, Columbus, Ohio; John Roberts and W.W. Ford, Dept.
Natural Resources, Division Reclamation, Frankfort, Kentucky;
Richard L. Hodder, Agriculture Experiment Station, Montana
State University, Bozeman, Montana; Richard M. Smith, Division
of Plant Sciences, West Virginia University, Morgantown,
West Virginia.
Sincere appreciation is extended to Dr. R.V. Ramani, Associate
Professor of Mining Engineering, Dept. Mineral Engineering,
The Pennsylvania State University, University Park, Pennsylvania,
for his cooperation, advice and contributions during report
drafting.
xiv
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SECTION I
CONCLUSIONS
1. In 1972 over 595 million tons (5^0 million metric tons) of bituminous coal
were mined; h9% of this tonnage was obtained by surface mining methods.
Authorities have predicted that the tonnage of surface mined coal will increase
in the future, especially since oil and gas resources are becoming limited.
2. Demands for clean air have increased mining activities in the low-sulfur
coal deposits in the West. Pollution problems arising from these operations
will be considerably different than those found in the East. The deposits are
located in arid to semi-arid regions. Coal seams are generally aquifers and
are a principle source of fresh water. Therefore mining may result in altera-
tion of groundwater distribution patterns by aquifer disruption. In general,
pollution problems associated with western mining are not well characterized.
3. Since any disturbance of the surface will alter the environment in the
vicinity of the disturbance, pre-mining planning is a prerequisite to any
environmentally successful surface mining operation. If properly carried out,
the adverse social, economic, and environmental effects of coal surface mining
will be minimized. Certain land areas will be unsuitable for surface mining
where:
a. Reclamation is not physically or economically possible.
b. Mining is incompatible with existing land use plans.
c. The proposed mining area is of critical environmental concern.
Core drilling is the most satisfactory method of obtaining accurate
information for pre-mining planning.
it. Unaccountable strip mining in the past has created problems that are still
present today. Contour mining methods that involve the indiscriminate dumping
of overburden on the downslope is one of the largest single sources of sediment
from strip mining. However, land disturbed by strip mining can be reclaimed.
Techniques have been and are being developed by which mining and reclamation
are integrated into a single operation. Mountain top removal, head-of-hollow
fill, and block cutting are examples in contour surface mining. These methods
drastically reduce pollution problems associated with contour stripping.
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5. Mine drainage arising from surface coal mining activities may result in
serious pollution. The pollutant can "be in a physical form (e.g., sediment),
or chemical form (e.g., acid mine drainage) or a combination of both.
6. Surface mining increases the rate of erosion which is a natural process.
By development and implementation of erosion and sediment control plans before,
during, and after mining, erosion can be minimized.
7. Sediment control basins as currently designed and constructed are only
marginally effective in reducing suspended solids discharges. Further develop-
ment is required in this area.
8. Sediment yield from improperly designed and constructed coal-haul roads
can be as great as that from the stripping phase. Technology developed for
road design for other purpose, e.g., logging roads if applied to surface mines
should greatly reduce the sediment problem.
8a. Siltation from coal surface mining in flat to rolling terrain is less
acute than from mining operations in mountainous regions.
9- Acid Mine Drainage (AMD) is the result of oxidation of pyritic materials
located in the overburden and coal. During mining and in situations where
underground mines have been breached, resulting in acid water discharges, it
is necessary to treat the water before discharging. Neutralization is the
practice most commonly used. Several alkaline agents and neutralization
systems are available. The specific ones used will depend on the individual
situation. Although neutralization will increase the pH, reduce the acidity,
iron, etc., the resulting water will still contain high levels of sulfates
and dissolved solids. In surface coal mining the most positive control of AMD
is obtained by proper mining and reclamation techniques — for example, current
reclamation that includes overburden segregation, burying of toxic materials,
and topsoiling.
10. Blasting can fracture rock strata and provide fissures in the bed rock.
These entries result in acid or saline pollution of the groundwater. Blasting
can also disrupt the flow of water to aquifers, and create noise and vibration
problems. Recent developments in blasting materials and methods have minimized
some problems, but further research and development is required.
11. The primary function of revegetation should be to stabilize the soil to
prevent erosion and AMD. Secondary land usage should be considered, but not
lieu of stabilization. In most cases, revegetation is best accomplished by
the establishment of grasses and legumes, as soon after mining as possible.
in
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12, Great strides have been made in vegetation selection and establishment
under eastern mining conditions. Major research, development, and demonstration
is needed for semi-arid and arid western conditions.
13. The removal and placement of growth supporting soil material, or "top
soil", is one of the most beneficial methods for assuring establishment of
vegetation. Soil is a natural resource and its value may equal or exceed that
of the coal mined. The value of coal is finite. Once it is mined and used,
its value as a resource is exhausted. On the other hand, the value of the soil
resource, if the soil is preserved, will continue on indefinitely.
lU. It is impossible to guarantee that pollution from surface mining of coal
can be completely eliminated. However, it is realistic to expect that
pollution can be greatly reduced.
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SECTION II
INTRODUCTION
The United States is richly endowed vith mineral resources. Hovever, mineral
recovery by its very nature , involves a destructive process, Figures 1 and 2.
In the past, mining practices were all too often conducted with the purpose
of removing minerals by the simplest and cheapest method possible, without
plans for the preservation of land, water, and air, and with too little con-
sideration for the rights of others. A mining company is in business to make
a profit, but every company, regardless of the nature of its business, has
moral obligations -to reduce its undesirable effects on the environment and to
safeguard the rights of others.
The problem of environmental degradation caused by surface mining is widespread
and serious . Minerals in some form occur in each of the 50 States and several
States are extensively mined. Data on the acreage disturbed in the United
States, by commodity and State are presented in Table 1. Thirty-one States
have laws regulating surface mining, (Table 2). Briefly reviewed in Appendix
A-l are the basic provisions of State laws governing surface mining. It can
be seen that these laws vary considerably from State to State owing largely to
the mining conditions within that State. Of the 2U coal -producing States, only
three (Alaska, Arizona, and Utah) do not regulate strip mining.
Even the states that are often cited as models of comprehensive regulations
still have problems minimizing environmental damages. Uncontrolled surface
mining presents a situation as critical to the well-being of the society as
any it has ever faced.
Many mining activities have imposed huge social costs on the public at large.
These costs are long-range and are in the form of stream pollution, floods,
landslides, loss of fish and wildlife habitats, unreclaimed land, erosion,
and the impairment of natural beauty.
In a 1965 Department of Interior study, Wit was estimated that of the
25,000 miles (U0,225 kilometers) of contour bench in Appalachia, approximately
1,700 miles (2735 kilometers) are affected by massive landslides. Additionally,
1*800 miles (7723 kilometers) of streams and 29,000 surface acres (11,716
hectares ) of impoundments and reservoirs have been seriously affected by coal
strip mining operations in the United States.
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n
Figure 1. Aerial view of area
mining.
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Figure 2. Contour mining in Appalachia.
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Table 1. STATUS OF LA1JD DISTURBED El SURFACE KIOTO IB 1KB UNITED STATES AS OF JAE. 1, 1.97k, BY STATES1, (ACRES)
Land needing reclamation
Reclamation not required by any law Reclamation required by law
State
Alabama
Alaska
Arizona
Arkansas
California
Caribbean area
Colorado
Connecticut
De laware
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
Coal
mines
57,878
2,400
150
9,451
—
—
4,687
—
—
—
—
—
—
49,748
2,500
25,650
43,700
69,000
—
—
2,250
—
500
—
--
72,506
300
—
—
—
—
—
—
—
10,000
23,926
13,858
—
159,000
—
--
790
20,500
5,470
120
—
18,000
471
25,720
234
3,078
Sand and
gravel
17,369
1,900
3,180
7,973
62,730
—
20,655
9,930
2,558
11,144
1,285
25
10,635
4,840
8,500
20,300
13,062
—
14,820
23,030
11,825
15,642
43,402
29,789
34,529
6,426
9,800
15,138
16,474
7,900
16,500
6.506
38,184
11,900
9,200
15,557
6,348
5,105
10,500
2,000
8,500
9,455
4,850
126,595
1,480
4,350
1,725
11,328
1,000
40,526
400
Other mined
areas
17,747
4,000
48,700
10,293
6,970
—
512
160
330
110,402
14,779
1,000
13,598
3,130
7,800
2,414
19,052
—
959
1,592
3,942
1,738
24,769
25,592
10,069
11,850
5,890
4,087
5,401
--
500
14,150
17,426
4,800
2,500
19,276
5,209
1,495
20,500
700
12,000
5,601
6,000
51,927
1,800
—
5,475
6,935
—
5,405
11,920
Coal
mines
7,118
—
—
494
—
—
641
< —
—
—
—
—
175
20,891
6,000
—
2,500
117,000
—
--
3,851
--
—
—
—
1,250
300
—
—
—
—
25,798
—
—
200
45,825
6,350
—
33,000
—
—
—
5,200
—
—
—
5,014
1,010
51,560
76
2,828
Sand and Other mined
gravel areas
1,800
--
—
3,417
—
—
18,484
4,675
—
1,467
1,125
—
594
45
—
—
598
2,852
—
1,236
4,749
12,798
7,286
9,124
—
75
200
—
—
—
600
—
6,123
3,700
500
__
2,044
80
12,500
—
—
6,012
100
—
—
—
775
9,649
—
7,204
280
2,816
--
—
1,515
--
—
417
425
—
71,472
12,425
—
938
1,284
200
—
2,068
7,083
—
455
966
1,422
880
5,288
—
625
660
--
--
--
200
—
1,752
5,200
100
—
2,883
20
22,500
—
—
595
600
—
—
—
2,455
1,146
990
7,686
Land not
requiring
reclamation
75,432
4.260
43,070
14,822
109,500
—
13,582
130
1,717
54,694
8,744
250
3,251
103,579
123,662
—
14.028
94,000
6,925
13,287
16,683
23,150
22,601
69,071
873
20,596
15,260
6,161
13,288
4,400
12,200
1,261
18,458
7,000
23,000
225,664
21,211
2,900
220,000
1,300
15,000
51,034
88,450
30,311
2,800
—
38,664
2,494
197,930
23,887
15,398
Total land
disturbed
180,160
12,560
95,100
47,965
170,200
—
58,978
15,320
4,605
249,179
38,358
1,275
29,191
183,517
148,662
48,364
95,008
289,935
22,704
39,600
44,266
54,750
99,433
138,864
45,471
113,328
31,610
25,386
35,253
12,300
30,000
47, 715
81,943
32,600
45,500
330,248
57,903
9,600
478,000
4,000
35,500
73,537
125,700
214,303
6,200
4,350
72,103
33,033
276,210
78,323
41,590
Total
621,887
756,870
549,686
337,081
120,092
157,066
1,876,028
4,418,710
Ifiased on information supplied by Soil Conservation Service State conservationists.
Acre = 0.1*0 hectares
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Table 2. STATE-ENACTED SURFACE MINING LAWS(l)
Year enacted or amended
State 65 66 67 68 69 70 71 72 • 73- 7^
Alabama(2).... * ~—
Arkansas (2)... * —
Coloradp(2)... * A
Florida(2) * —
Georgia *
Idaho *
Illinois (2)... 0 A — A —
Indiana(2) o A
Iowa(2) * —
|Cansas(2) * —
Kentucky (2)... o A '
Maine *
Mary land (2)... 0 A ^ A
Michigan...... * A
Minnesota * A
Missouri (2)... * —
Montana(2) * A A A
New Mexico (2). *
North Carolina * —
North Dakota(2) * A
Ohio (2) 0,A A
Oklahoma (2),.. * A
Oregon * —
Pennsylvania(2) Q A A A
South Carolina —- * —
South Dakota * —
Tennessee (2).. * A —
Virginia(2)... * A —
Washington (2). —- * —
West Virginia(2) 0 A A
Wyoming (2).... * A —
Total 71325^6210
Law enacted before 1965;
(2)
Coal producing States (21 total; Alaska, Arizona and Utah do not have
surface mining laws).
original enactment;
A
amended.
-------
Coal is the Nation's most abundant and widely distributed fuel resource
(Figures 3 and h}. Total reserves are estimated at 1,560 billion tons (
million metric tons) or over 2,500 years' supply at present consumption rates
(Table 3). The data denotes availability on broad, long termbasis regardless
of availability for mining or whether they are economically minable- Table U
indicates that most of the coal reserves must be deep mined, as only ^5 billion
tons (or less than 3$) are economically minable by strip mining methods.
Although coal is abundant and widespread in the United States, resources of
coal also have limits. In the extensively mined eastern coal fields, new
areas containing thick beds of high rank coal are becoming scarce. Low-volatile
bituminous coal used in the manufacture of coke constitutes only about 1 percent
of the total resources. A large part of the total resources consists of lignite
and subbituminous ranks, which yield less heat than bituminous coal. Another
large part is contained in thin beds and in deeply buried beds that can be
mined only with great difficulty and expense.
Coal is classified by rank according to percentage of fixed carbon and heat
content, calculated on a mineral-matter free basis. In terms of usefulness,
comparison of the resources of lignite and subbituminous coal, which have low
heat values, with resources of bituminous and anthracite coal, which have
higher heat values, can best be made on a uniform Btu basis, Figure 5-
Since World War II, surface mining has emerged as a dominant force in the
production of coal, bringing with it new and perplexing problems in land use
and water control. The current expansion is due mainly to the greater pro-
duction per man day, lower production costs; these result from new technology,
which has produced equipment that has made strip mining highly productive and
efficient.
In 19UO, 9.h% of the total coal production was from surface mining, the 1972
figures show an increase to k9% (Table 5). It is projected that for the
remainder of this century surface mined coal will account for over 50$ of the
Nation's production.
Strip mining can be done responsibly without permanent damage to the land and
water. Technology exists for effective the reclamation of mined lands and
such reclamation is being performed in some areas.
A certain price in environmental damages usually must be paid to obtain the
coal required for our standard of living. The basic question is: What price
are we willing to pay?
This report will discuss damages caused by surface mining (with emphasis on
coal), outline techniques that will hold damages to a minimum, discuss proce-.
dures to restore the land after mining has occurred and highlight areas requir-
ing further research and development. Because of the interrelationship of the
many phases of surface mining, it was not possible to eliminate all duplication
without sacrificing continuity. Appropriate references appear at the end of
each section and are readily available to the reader, who desires more specific
or detailed information on the subject matter in that particular section.
-------
--W--T——S--A .
v NORTH / I
\\ :
. \H
• < X4* .
/ \ MINNESOTA
1 PLAINS / \
•PROVINCE/ I/ ~^~, (
'•\\""-//
\ j. ___ _
A"" l°""'
Adoplid Iron U.S.e.S. Cool Mop ol IM
Un.l.d SUI»., I960.
Figure 3. Bituminous and subbituminous coal and lignite
fields of the conterminous United States.
-------
i'OO
L EGEND
Bituminous coal
Subbituminous cool (Includes some
lignite in the Nenana, Susitna, and
Kertoi fields)
Lignite field
Bituminous coal occurrence
Subbituminous cool occurrence
*3 Lignite occurrence
Note — Occurrences ore coal of unknown
extent
Adopted from U.S.G.S.Cool Mop of Alaska., I960.
Figure h. Coalfields of Alaska.
-------
Table 3.
COAL RESERVES OF THE UNITED STATES
(Millions of Tons)*
, BY STATES
Overburden 0-3,000 ft. thick
Alabama
Alaska
Arkansas
Colorado........
Georgia
Illinois
Indiana
Iowa
Kansas
Kentucky........
Maryland
Michigan
Missouri
Montana
New Mexico
North Carolina..
North Dakota....
Ohio
Oklahoma
Oregon
Pennsylvania....
South Dakota....
Tennessee
Texas.
Utah
Virginia
Washington
West Virginia...
Wyoming.,
Other States....
Total
Resources determined by mapping and exploration2
Bituminous
coal
13,518
19,415
1,640
62,389
18
139,756
34,779
6,519
18,686
65,952
1,172
205
23,359
2,299
10,760
110
0
41,864
3,299
48
57,533
0
2,652
6,048
32,100
9,710
1,867 .
102,034
12,699
7/ 618
671,049
Sub-
bituminous
coal
0
110,674
0
18,248
0
0
0
0
0
0
0
0
0
131,877
50,715
0
0
0
0
284
0
0
0
0
150
0
4,194
0
108, Oil
8/4,057
428,210
Lignite
20
4/ ....
350
0
0
0
0
0
6/ ....
0
0
0
0
87,525
0
0
350,680
0
6/ ....
0
0
2,031
0
6,878
0
0
117
0
4/ ....
~±l 46
447,647
Anthracite
and semi-
anthracite
0
5/ ....
430
78
0
0
0
0
0
0
0
0
0
0
4
0
0
0
0
0
12,117
0
0
0
0
335
5
0
0
0
12,969
Total
13,538
130,089
2,420
80,715
18
139,756
34,779
6,519
18,686
65,952
1,172
205
23,359
221,701
61,479
110
350,680
41,864
3,299
332
69,650
2,031
2,652
12,926
32,250
10,045
6,183
102,034
120,710
4,721
1,559,875
Est. addtl.
resources in
unmapped
and unex-
plored areas3
20,000
130,000
4,000
146,000
60
100,000
22,000
14,000
4,000
52,000
400
500
0
157,000
27,000
20
180,000
2,000
20,000
100
10,000
1,000
2,000
14,000
48,000
3,000
30,000
0
325,000
1,000
1,313,080
Est. total
remaining re-
sources in
the ground.
0-3,000 ft.
overburden
33,538
260,089
6,420
226,715
78
239,756
56,779
20,519
22,686
117,952
1,572
705
23,359
378,701
88,479
130
530,680
43,864
23,299
432
79,650
3,031
4,652
26,926
80,250
13,045
36,183
102,034
445,710
5,721
2,872,955
Est. resources
in deeper
structural ba-
sins 3,000-
6,000 ft.
overburden3
6,000
5,000
0
145,000
0
0
0
0
0
0
0
0
0
0
21,000
5
0
0
10,000
0
0
0
0
0
35,000
100
15,000
0
100,000
0
337,105
Est. total
remaining re-
sources in
the ground,
0-6,000 ft.
overburden
39,538
265,089
6,420
371,715
78
239,756
56,779
20,519
22,686
117,952
1,572
705
23,359
378,701
109,479
135
530,680
43,864
33,299
432
79,650
3,031
4,652
26,926
115,250
13,145
51,183
102,034
545.710
5,721
3,210,060
Short tons = 0.90? metric tons; foot = 0.30U meters.
1 Figures are for remaining resources in the ground, as of Ian. 1,1967, about half
of which may be considered recoverable. Includes beds of bituminous coal and
anthracite 14 in. or more thick and beds of subbituminous coal and lignite 2*4 ft.
or more thick. (Study by Paul Avcritt, U.S. Geological Survey)
2 Estimates from published reports of the U.S. Geological Survey and individual
State Surveys reduced by production and losses in mining from date of estimate
toJan. 1,1967. Losses assumed to be equal to production.
» Estimates by H. M. Beikman (Washington), H. L. Berryhttl, Jr., (Virginia and
Wyoming), R. A. Brant (Ohio and North Dakota), W. C. Culbertson (Alabama),
K. J. Enghind (Kentucky), B. R. Haley (Arkansas), E. R. Landis (Colorado and
Iowa), E. T. Luther (Tennessee), R. S. Mason (Oregon), F. C. Peterson (Kaiparo-
wits Plateau, Utah), J. A. Simon (Illinois), J. V. A. TrumbuU (Oklahoma), C. E.
Wier (Indiana), and Paul Averitt for the remaining states.
4 Small resources of lignite included under subbituminous coal.
s Small resources of anthracite in the Bering River field believed to be too badly
crushed and faulted to be economically recoverable.
• Small resources of lignite in beds generally less than 30 in. thick
' Arizona, California Idaho Nebraska, and Nevada. Bituminous coal in Black Mesa
field, Arizona included under subbituminous coal.
8 Arizona, California, Idaho.
9 California, Idaho, Louisiana, Mississippi and Nevada.
Source: U.S. Geological Survey
12
-------
Table 4. ESTIMATED STRIPPABLE RESERVES OF COAL AND LIGNITE
IN THE UNITED STATES, JANUARY 1, 1968, BY STATE
(Millions of short tons)*
Subbituminous
coal2 L±i
Bituminous
Alabama 13k 0 3 134
Alaska ^80 ^ 53,926 5 Mil
Arizona 0 38? 0 38?
Arkansas 149 0 25 l?li
California 0 25 0 25
Colorado 500 (2) 0 500
Illinois v « 3,247 0 0 3,247
Indiana 1,096 0 0 1,096
Iowa 180 0 0 180
Kansas 375 0 (3) 375
Kentucky—east 78l 0 0 781
Kentucky—west 977 0 0 977
Maryland 21 0 0 21
Michigan 1 001
Missouri 1,160 0 0 1,160
Montana (1) 3,400 3,497 6,897
New Mexico (1) 2,474 0 2,474
North Dakota 0 0 2,075 2,075
Ohio 1,033 0 0 1,033
Oklahoma Ill 0 0 111
Pennsylvania 752 0 0 752
South Dakota 0 0 160 160
Tennessee lk 0 0 fh
Texas C1) 0 1,309 1,309
Utah 150 0 0 150
Virginia 258 0 0 258
Washington (l) 135 0 135
West Virginia 2.118 0 0 2,118
Wyoming ,,(1)- 13.971 _-Q 13.911
Total 13,597 24,31Q T,OT1 44,971
"Short tons = 0.907 metric tons.
^Bituminous coaL-reserves not estimated for Idaho, Montana, Nebraska, New
-Mexico, Texasywashington, and Wyoming.
^Subbituminous coal reserves not estimated for Colorado and Oregon.
^Lignite reserves not estimated for Alabama,Kansas, Louisiana, and Mississippi.
H78 million tons of bituminous and 3,387 million tons of subbituminous coal
reserves in the northern Alaska fields (North Slope) are included in the
estimates even though an economic export market, which is essential for
exploitation, does not currently exist.
''includes 179 million tons of undifferentiated subbituminous coal and lignite.
Source: U.S. Bureau of Mines.
13
-------
16,000
COAL RANKS
Figure 5. Comparison of coal ranks by heat valves,
Source: Geological Survey Bulletin 1275
-------
Table 5. UHITED STATES PRODUCTION OF BITUMINOUS AND LIGNITE
COAL AT DEEP AND SURFACE MINES, 191*0-1972
YEAR
1950
I960
1965
1966
1967
1968
1969
1970
1971 1972
Surface
Mining
Under-
ground
Mining
1*^.2
9.1*$
*17-6
90.6$
L23.5
23.92
392.8
76.1$
130.6
31.1*$
281*. 9
68.6$
179-1*
35-0$
332.7
65.0$
195. ^
36.6$
338.5
63.1*$
203.5
36.8$
31*9.1
63.2$
-,
201.1
36.9$
31*1*. 1
63.1$
<-
213.1*
38.1$
31*7.1
6l.9$
261*. 1
1*3.8$
338.8
56.2$
276.3
50.0$
275.9
50.0$
291.3
1+8.9$
301*. i
51.1$
Total
5l6<3
512>1
MILLION TONS AND PERCENT OF TOTAL*
Short tons = 0.907 metric tons
-------
While the big concern today is the use of coal for energy there is a real
possibility in the near future that the nation will become more dependent on
coal for supplying the basis of its chemical industry. It is, therefore, easy
to assume that coming generations will need to recover all of this valuable
resource. To this end, new mining methods are needed.
REFERENCE
1. "Surface Mining and our Environment". U.S. Department of Interior,
Washington, B.C. (196?).
16
-------
SECTION III
PREMINING PLANNING
INTRODUCTION
Mining as an extractive process alone is outdated and unacceptable to today's
environmentally concerned public. Multiple land use must be considered as well.
Only through effective preplanning can the full potential of reclamation result
in a lasting asset for future generations.
The coal industry is now recognizing that reclamation of mined lands is part of
the mining cycle that must be planned and carried out in a timely and orderly
manner. It is also finding that planning reclamation in advance of mining is
cheaper and more effective than waiting until mining is completed.
The decision to open a strip mine must be based on the results of studies to
determine if successful reclamation can be achieved and whether the economic
benefits to the company will be justified(l). Information regarding the physical,
chemical, hydrologic and biologic systems operative at the site must be under-
stood or reclamation will be a failure. Working together, engineers, management
and reclamation specialists should design the actual mining and reclamation
plan before mining is begun.
MAPPING
Mapping the land is the first step in developing the surface mine operation.
Usually, enlarged U.S. Geological Survey maps are used for this purpose. Some
of the larger companies use aerial survey maps because of the greater accuracy and
detail. Photography must be done in the early spring or late fall so that the
tree foliage will not hide the surface characteristics.
After the basic maps are prepared prospecting information about the coal seam,
overburden, soil survey results and the drainage plan is plotted as it is accumu-
lated. If areas near the proposed mining site have already been mined this
information can be quickly obtained (Figure 6). These maps are used to calculate
overburden ratios and thickness of topsoil and to plot outcrop lines, property
lines, underground mine openings, access roads, spoil and refuse areas, public
and private utilities, and location of bore holes. Drainage patterns can be
studied and incorporated into the mining plan. Prospecting information will
prove to be most helpful when preparing application maps that are required for
most State mining permits. A sample copy of an application map that meets the
requirements of the West Virginia law is presented here as an example only
(Figure 7).
IT
-------
I
Figure 6. Highwall sampling.
-------
Figure 7. Permit application map.
-------
LEGEND
rater
. 90
/L K
.,:'• :•• ...•.•.•.v.i.-i-.
~ : - 2200 'X30'
TEST Houes
2. /*// 6.0
4.
re ~/00 /^ £70
69
Figure 7 (continued). Permit application map.
20
-------
: a /tt /WCTV* x jso /&.*£. sz?
~* -- — 72?
72>
0/sr*/cr rxttrw cowry
Figure T (continued). Permit application map
21
-------
PROSPECTING
Prospecting is conducted to locate a seam and obtain further information on the
quality and quantity of coal and overburden. 'When the coal bed outcrops,
prospecting is often conducted with dozers and endloaders at regular intervals
along the outcrop. Providing access for the equipment is often the beginning of
water pollution problems. The cheapest type of access is generally utilized
bulldozers, for example ^that get to the site as quickly as possible and ignore
the resulting avoidable environmental damages. The general practice in digging
test pits has been to dump excavated material alongside the pit and abandon the
pits after collection of samples. These pits and roads contribute to the sedi-
mentation of receiving streams and leave lasting scars on the landscape. Roads
and excavations should be carefully planned, installed, and stabilized upon
abandonment to minimize erosion.
In unmined areas, core drilling is the most satisfactory method for obtaining
samples for analysis and information on the location and thickness of the
mineral and depth, type and elevation of overburden (Figure 8). Sufficient holes
must be drilled to get an accurate picture of the area to be mined to determine
in advance of mining coal reserves, spoil selection, handling and placement and
reclamation techniques. Core drilling information will also show where conditions
warrant special mining or soil handling methods. Most overburden materials under-
go physical, chemical, and biological changes after becoming disturbed and may
prove troublesome if not properly handled. These special mining methods may
in turn require equipment other than that originally planned for use. For
example, a longer dragline boom might be necessary to provide the additional
reach for burial of a highly saline or acid shale that would otherwise be left
near the surface. Thus, mapping and core-drilling together, form a basis upon
which to select the proper mining methods and equipment to do the total job.
Any land affected by prospecting should be promptly reclaimed and revegetated.
Drill holes should be plugged with cement grout which will form a tight and last-
ing seal to prevent the discharge of mineralized water to streams. These pro-
cedures are not necessary if mining is to immediately follow prospecting. In
such cases, the prospecting sites would be mined through. Techniques for
identifying potential problem strata before mining are being developed^,3,^).
These studies will provide information about coal overburden to enable operators
to place, treat, and manage spoils in the most favorable manner to assure water
and spoils of good quality during surface mining and reclamation.
Grube et al.'2' have established three parameters to identify toxic or potentially
toxic material in overburden subject to acid conditions:
1. pH of the pulverized rock slurry in distilled water;
2. total or pyritic sulphur;
3. "neutralization potential" or calcium carbonate equivalent.
The pH gives the current status of the material, whereas a balance between the
sulphur content and alkaline content predicts the long-term nature'of the
material.
22
-------
•:•
Figure 8. Two inch test core,
-------
Figure 9 illustrates the rock characterization and summary of chemical analyses
of a section extending 100 feet (183 meters) above the Pittsburgh coal seam
near Century, Barbour County, West Virginia. The analyses were performed on
samples obtained by collecting expelled rock chips from a compressed-air
rotary drill placed above the highwall on active Jobs. .Acid-base accounts were
plotted on 3-cycle semilog paper (K&E U6-5501), and the rock type and pH were
plotted on 10 by 10 inch; all were then glued together and photographically
reduced to the size of Figure 9-
The methods of applying these measurements to coal overburden materials are
described in detailed step-by-step procedures by Grube et al(2).
Core samples can also be used to determine toxic levels of elements such as
iron, zinc, copper, and sodium, and the shortage of essential plant nutrients.
The information should also serve as a guide to the proper movement and place-
ment of the overburden and the reclamation requirement. The U.S. Forest Service,
Grube(2) and the U.S. Environmental Protection Agency are developing and
evaluating methods for analyzing overburden for their nutrient and toxic
characteristics.
New overburden core analysis procedures developed at the Montana Agricultural
Experiment Station by Sindelar et al.(^) are intended to predict reclamation
problems before active mining commences at a potential mine site. The nature
and depth of overburden, its stratigraphy, chemical and physical properties,
weathering characteristics, and ability to support plant life are obtained
through field and laboratory analysis.
Characterization of rock cores, highwalls, land fragments, and other, materials
has brought geologists, soil scientists, plant scientists, and chemists together
in many discussions of these overburden and minesoil materials. In an effort to
reach a common baseline in recognizing these minerals, a. classification system
for overburden materials with a set of standardized defined terms was assembled
and reported by Grube et al.(2).
Hardaway'"' reported that many of the western coals were extremely good
aquifers in themselves or were portions of good aquifers. Since normal restora-
tion procedures involve deposition of plant-toxic material and-permeable
material at the bottom of the pit (where the coal was), deposition of clays and
shales in place of the coal could serve to dam the aquifers and to subsequently
cause rises in water tables up-gradient of the mined areas and decreases in
water tables down-gradient of the mined areas. The rise in water up-gradient
could cause undesirable saline seeps whererione existed before mining. Thus,
alone with developing sufficient hydrologic information before mining, to pre-
dict the possibility of such "dams" being formed, one must consider measures of
creating aquifers. Certain areas in which adequate material for artificial
aquifers is not available should not be mined. Scoria has been suggested as a
material that could be used to construct artificial aquifers in places where
coal seams served this purpose before mining.
Soil maps should be studied as part of the pre-plan. Materials in the over-
burden that will support vegetation must be salvaged for reuse in reclamation.
Suitable materials that can be saved be identified with the aid of soil maps.
Soil survey information is available from the Soil Conservation Service, State
-------
DEFICIENCY
1.0 % SULFUR (») 0.1
EXCESS
100 60 40 20 108 6 4 2 I * 2 4 6 8 10 20 40 60 100
Chroma
MUDSTONi
CaC03 EQUIVALENT
(TONS/THOUSAND TONS of MATERIAL)
SANDSTONE
UMISTONI
COM
SHALf
Figure 9. Acid-tase account.
25
-------
agricultural schools, and local county agents. Top soil and spoil storage
areas are selected and must be free of underground mine openings, seeps or wet
weather springs.
Hevegetation plans for the disturbed area, including access roads, are drawn up
during preplanning. These plans are more or less guidelines and are subject to
change when the actual work is performed following final grading. However, the
original plan should be followed as closely as possible. The selection of
vegetation will depend a great deal on the ultimate use of the area. The first
concern should be stabilization and erosion control, thus, grasses and legumes
are probably the primary choice. These plantings can be incorporated with
additional plaiting for forests, pastures, recreation, etc.
If merchantable timber products are on the area, provisions should be made for
their harvest before mining.
DRAINAGE
During preplanning, water management is of vital concern. The natural drainage
pattern is studied and plans are made to drain the mining area to a natural
waterway. Precautions must be taken not to overload the water course and cause
excessive erosion. Provisions need to be considered for the control of sediment
by trapping it on site through the use of water retarding measures or off site
by engineered sediment control impoundments. If the decision is to build im-
poundments then the sites must be located and struct-ures designed and constructed
before disturbance. The size of the structure is determined by the erosion rate,
storage capacity and retention time necessary to settle out the suspended solids
before discharge. Calculations are based on the total acreage in the drainage
area and the total acreage that will be disturbed above the impoundments'(see
Section VI, Sediment and Erosion Control).
SUMMARY
Preplanning involves coordinated efforts by the engineers, operational and
management personnel, and reclamation specialists to develop mining and reclama-
tion plans before actual disturbance. These plans are based on detailed studies
regarding the physical, chemical, hydrologic, and biologic systems operative at
the mining site.
Basic maps of the area are prepared and updated as prospecting information be-
comes available. The completed maps will show the location of access roads,
major waterways, sediment control structures, spoil storage areas, bore holes,
coal outcrops, property lines, utilities, etc.
The preplan contains mining techniques for spoil segregation and placement, grad-
ing, erosion control, and water management practices along with plans for
establishing vegetation on all disturbed areas as soon as possible.
It is essential that the geochemistry of the overburden be understood and
considered in the preplan or reclamation will be a failure and result in
environmental degradation.
26
-------
REFERENCES
1. Riley, Charles V., Design Criteria of Mined Land Reclamation. Paper
presented at the SME Fall Meeting and Exhibit, Birmingham, Alabama,
October 1972.
2. Grube, Walter E. Jr., Smith, Richard Meriwether, Singh, Rabindar, and
Sobek, Andrew A., Characterisation of Coal Overburden Materials and
Minesoils in Advance of Surface Mining. Paper presented at the Research and
Applied Technology Symposium on Mined-Land Reclamation, Pittsburg,
Pennsylvania, March 1973.
3. Caruccio, Frank T., Ferm, J.C., University of South Carolina, Personal
communication with Mine Drainage Pollution Control Activities, U.S. Environ-
mental Protection Agency, NERC-Cincinnati, Ohio, December 1972.
U. Sindelar, Beian W., Hodder, Richard L., and Majerus, Mark E., Surface Mined
Land Reclamation Research in Montana, Progress Report 1972-1973. Montana
Agricultural Experiment Station, Montana State University, Bozeman, Montana.
5. Commonwealth of Kentucky, Division of Reclamation, Chemical Water Quality
Pollution Control 1973 (In press).
,6. Hardaway, John E., Report of Inspection of Coal Lands on Crow Indian Reserva-
tion and Vicinity Billings-Hardin-Crow Agency, Montana, May 1^-18, 1973.
EPA, Region VIII, Denver, Colorado.
7. McCarthy, Richard E. Preventing the Sedimentation of Streams in a Pacific
Northwest Coal Surface Mine. Paper presented at the Research and Applied
Technology Symposium on Mined-Land Reclamation. Pittsburg, Pennsylvania,
March 1973.
27
-------
SECTION IV
SURFACE MINING METHODS, TECHNIQUES, AND EQUIPMENT
INTRODUCTION
To better appreciate the problems associated with surface mining, it is impera-
tive that the stripping operation be understood. Surface mining is a very broad
term and refers to any process of removing the earth, rock, and other strata in
order to uncover the underlying mineral or fuel deposit. Strip mining is a type
of surface mining in which the overburden is removed in narrow bands, one cut
at a time. Strip mining methods employed to recover coal can be divided into
two general types: area and contour.
AREA MINING
Area strip mining is practiced on gently rolling to relatively flat terrain and
is commonly found in the midwest and far west (Figure 10). A trench or box-cut
is made through the overburden to expose the deposit of mineral or ore to be
removed (Figure 11}. The first cut is extended to the limits of the property
or deposits. The overburden from the first cut is placed on unmined land adja-
cent to the cut. The mineral or ore is then removed. Once the first cut is
completed, a second cut is made parallel to the first, and the overburden from
the succeeding cuts is deposited in the cut just previously excavated. The
deposited overburden is called spoil. The final cut leaves an open trench equal
in depth to the thickness of the overburden and the mineral bed removed,
bounded on one side by the last spoil pile and on the other by the undisturbed
highwall. The final cut may be up to a mile or more from the starting point,
and the overburden from the cuts, unless graded or leveled, resembles a plowed
field or the ridges of a gigantic washboard.
Area Mining Methods*
In the United States, area stripping is characterized by giant earth moving
equipment capable of handling several thousand cubic yards of material per hour.
Already production rates at many places are dwarfing those of the Panama Canal
and other well-known earth moving projects which are frequently identified as
massive undertakings. With projects of this scale, the need for increased
sophistication of engineering, planning, management and administration of modern
mining installations has never become more apparent.
*This sub-section was written by Dr. R.V. Ramani, Associate Professor of
Mining Engineering, Department of Mineral Engineering, The Pennsylvania State
University.
28
-------
Figure 10. Area strip raining in the midwest.
-------
U)
o
v •' •• i*-^ -~ 7''' v
'•• . ••'W?rV AhA* "\(,
M. »'••..•*»... ..aiJEW .,
,->>"'-- ..>!',, /..>»,. v>u, >u;
^ jrtl™'--V .V*.** ./ . t T.5i."f!V*^' -^.f**M^V^
ORI6INAL SURFACE
~ COAL Bl
Figure 11. Area strip mining with concurrent reclamation
-------
The load haul dump methods which are "becoming increasingly popular for contour
stripping may not be economically transferable to area stripping. Additionally,
large strip equipment require that they be dedicated with enough coal reserves
for several years operation to justify the capital expenditure for mining and
preparation.
Simple overcasting, explained in Figure 11, is still the commonest form of
stripping. However, the long-range plans for effective land use before, during
and after mining, the mining and reclamation methods to practice, and the
selection of stripping and reclamation equipment, etc., must be analyzed with
respect to geological, social, technical and economic constraints. Pit engineer-
ing to avoid unnecessary inventory and quenching delays becomes important as all
other equipment (equipment for drilling, coal loading and hauling, clean up,
etc.) must be carefully matched to the primary equipment and their capacities.
Primary equipment selection is also difficult because of the availability of a
wide range of equipment capable of working in all types of conditions.
In area stripping, shovels and draglines continue to be more popular, with drag-
lines increasingly favored over shovels. They are available in a wide range of
designs and capacities. The largest shovel and dragline in operation have
bucket capacities of 180 to 220 cubic yards (138 and 168 cubic meters) respective-
ly. However, there is no trend toward selecting the largest equipment available
and operators have continued to depend on equipment in the intermediate and
high ranges which have proven performances. Draglines provide greater flexibil-
ity, work on higher bank heights and move more cover per hour. Wheel excavators
hold considerable promise where conditions are favorable- Ideally, this machine
has the capability for continuous burden removal and selective placement of the
top soil. Designed capacities are up to 15,000 cubic yards (11,1+70 cubic meters)
per hour, though in practice figures of only 3,000 to U,000 cubic yards (2,29^
to 3,058 cubic meters) per hour have been realized. Scattered applications in
the country were not encouraging enough for their use extensively, and the
American experience remain confined more to Illinois. Additionally, the use of
"kolbe" or American wheels is more common.
In the West, where coal seams are unusally thick, open pit extraction techniques
find application. At many operations, large conventional road excavating and
grading equipment find wide use. Tractor scrapers, and bull dozers, while
generally used for auxilliary stripping, have recently been used for primary
stripping.
Multiple seam mining is practiced where two or more seams occur close together.
Such occurrences enable coal recovery in places where one seam by itself may not
be economically mineable. Overburden removal practices include deployment of a
shovel or a dragline operating alone, or in tandem to uncover the seams.
Drilling for fragmentation is commonly done with rotary type units capable of
hole diameters from 5% to 15% inches (ikO to 39^ millimeters) with vertical
drilling more common. Presently much concern is being expressed regarding noise
pollution and vibrations from blasting. Ammonium nitrate fuel oil (ANFO) mixes
continue to be the leading explosive. As more on this subject is covered in
Section V it will not be elaborated here.
31
-------
In the rest of this section, the general discussion above will "be extended to /
specific cases with a brief description of the equipment and method. Several1'
case studies are described in recent research reports from which some of the /
following are taken(l»2). , Mined-land can be and is being reclaimed for agri-
cultural and livestock farming, for reforestation, for recreation, housing or
industrial sites. The present discussion will exclude any mention of environ-
mental problems and their abatement as these are described in great detail
throughout the report.
Stripping with a Shovel
A coal seam, about U feet (1.2 meters) .thick, and overlaidrby 120 feet (36.5
meters) of shales, sandstones, clays and limestone, is exposed by a 105 cubic
yard (80 cubic meters) bucket, 200 foot (6l meters) boom, shovel. Vertical
drill holes 15% inches (39^ millimeters) in diameter spaced approximately
on a 50 x 60 foot (15 x 18 meters) grid pattern, reach within 5 feet (1.5 meters)
of the coal. Thirty to thirty-three 80 pound (36 kilograms) bags of ANFO are
loaded into each hole. Usually, three rows of holes are shot with delays between
each row. As can be seen in Figure 12, at any one time, a pit width of 180 feet
(55 meters) is maintained. Coal is loaded by a 9 cubic yard (7 cubic meters)
shovel from a 5U foot (l6.5 meters) cut into four 100 ton (91 metric tons)
trucks. Figure 13, shows a shovel in an operating pit.
Stripping with a Dragline
Figure ill shows a 220 cubic yard (l68 cubic meters) dragline removing 120 to
130 feet (36.5 to kO meters) of overburden over a k-foot (1.2 meters) coal seam.
It is capable of working a pit 250 feet (l6 meters) wide, and 185 feet (51*-1*
meters) deep. The overburden is prepared by bulk loading some 1% to 5% tons
(1.3 to 5 metric tons) of ANFO into each hole, drilled on a 30 by 30 foot (9
by 9 meters) grid. A 1^-cubic yard (ll cubic meters) loading shovel with k to 6
120-ton (109 metric tons) trucks is used for coal removal. The annual coal
production expected from this mine is about 2.5 million tons (2.27 million
metric tons). Figure 15 shows a dragline, and other equipment in an operating
pit.
Shovel and Bucket Wheel Excavator Tandem Operation
The Kblbe wheel excavator can operate most efficiently by the frontal block
digging method on benches of limited width. This must be so because the cutting
boom and the discharge boom are in a straight line, and have no independent
movement. Therefore, they swing in opposite directions, about the vertical axis
of the machine. The wheel excavator is used to remove the loose top soil and
soft beds whereas the harder beds are handled by a large stick shovel(3). As
shown in Figure 16, the wheel excavator removes the top 5\ feet (l6.5 meters)
whereas the shovel with a bucket capacity of 70 cubic yards (5U cubic meters)
removes the remaining k6 feet (Ik meters) both equipment operating from the coal
seam. The pit is about 1-% miles (2 kilometers) long.
32
-------
Plan View
Section View
Figure 12. Plan section views of a Bucyrus-Erie 1950-B pit,
33
-------
Figure 13. Shovel in an operating pit,
Figure 1J illustrates clearly the vheel excavator, the shovel and the coal
handling equipment in a shovel-wheel tandem operation.
Bucket Wheel Excavator and Dragline Tandem Operation
In Figure 18 is shown a wheel excavator-dragline tandem operation in an
Illinois mine. Both the equipment work from a bench 0 to 65 feet (0 to 20
meters) below the surface. The wheel removes the unconsolidated sand, clay
and gravel beds above the bench. Drilling (10^ inch — 267 millimeter —
diameter hole) is done on a 30-foot (9meters) square grid to fragment the
bench with ANFO explosive for removal by dragline. A 6-cubic yard (^.5 cubic
meter) loading shovel loads the coal onto ^-100 ton (91 metric ton) trucks for
hauling to the preparation plant, 3h to 5 miles (5.6 to 8 kilometers) away.
-------
Surface
120-130'
Plan View
L42-47" I- 175'
-*+*-
Section View
175'
Figure lU. Pit layout at Bucyrus-Erie U250-W operation.
35
-------
Figure 15. Dragline in an operating pit.
Stripping in the West
Earlier reference was made to the thick coal seams in the west.
Three operations which employ conventional road construction equipment will "be
described. Figure 19 shows a strip operation in Wyoming. A 32-foot
(10 meter) coal seam is overlaid by soft and unconsolidated material. As can
be seen in the photograph, bulldozers and scrapers remove the overburden atop
the coal. In the foreground, a shovel loads the blasted coal onto trucks.
-------
Stripping Shovel
Wheel Excavator
Coal Shovel
Figure l6. Pit layout at a shovel and "bucket wheel
excavator tandem operation in Illinois.
37
-------
Figure 17. Shovel and bucket wheel excavator in tandem operation,
Figure 20 shows an open-pit operation where a 30 foot to 90 foot (10 to 27.k
meter) coal seam is overlaid by about 35 feet (ll meters) of soft overburden
which requires no preparation. The coal in this pit is mined in two benches,
each 30 to k
-------
Bucket
Excavator
Wheel
Cut
Dragline
Spoil
h-90'—H— 90'-H
Section View
Figure 18. Plan and section views of a dragline and bucket
wheel excavator in tandem operation.
39
-------
Figure 19. Dozer-scraper operation in Wyoming.
dozer pushes the dumped overburden into the mined out area of the pit at
point B. The scraper route is represented by the dotted line. The coal is
loaded by 10-cubic yard (8 cubic meter) front-end loader onto six 28-ton
(25 metric ton) trucks for a short haul, 1/2 mile (0.8 kilometers) to the
pover plant.
Figure 21 shows a multiple seam scraper operation. Several pan scrapers and
bull dozers are used to remove the TO to 130 feet (21 to hO meters) of over-
burden over the 10 foot (3meters) thick Armstrong seam, and the 35 to kO foot
(ll to 12 meters ) parting to the 50 foot (15meters) thick Monarch seam complex.
The topography of the area is somewhat hilly, and the overburden requires
blasting only when large rocks or boulders are encountered. When sufficient
length of the upper seam is exposed (1,000 feet — 305 meters), some earth
moving equipment is assigned to remove the parting and expose the lower seam.
1*0
-------
Haulage Road
Exposed Lower Bench
Exposed Upper Bench
V V
Surface
Figure 20. Plan view of a Wyoming open pit coal mine.
The operation nov resembles an open-pit scheme with two benches. This is a
massive earth moving operation. The scrapper haul is about 3,500 feet (1,06?
meters) and this equipment combination has. been used to depths of 250 feet (76
meters). Coal is loaded onto 9-50 ton(^5 metric tons) trucks by 2 loading
shovels of 8 cubic yards (6 cubic meters) and U cubic yards (3 cubic meters)
bucket capacities. Production is estimated to be 2 million tons (1.8 million
metric tons) per year.
Multiple Seam Operation with a Shovel
In Figure 22 is shown a 65 cubic yard (50 cubic meter) shovel uncovering two
seams. The maximum overburden in the property is 120 feet (36.5 meters) with
the parting between the seams varying from 3 to 18 feet (.9 to 5-5 meters).
The shovel sits on the bottom seam, and uncovers both the seams during a single
cut(5). The overburden above the upper seam and the parting must be fragmented
with explosives. In the overburden, 9 inch (229 millimeter) horizontal holes
are drilled on 30 foot (9 meters) centers. In the parting, 9 inch (229 milli-
meters) vertical holes are drilled on a 12 by lU foot (3.7 to U.2 meter) grid.
-------
Exposed Armstrong
Coal Seam
Plan View
Surface
t
70-130'
35-40'
Armstrong Seam
50'
Monarch
Complex
300-400'
300-400'
Section View
Figure 21. Plan and section views of a multiple seam scraper operation.
-------
TOP
PREVIOUS
SPOIL
SEAM j BSEAM I PREVIOUS
IF COAL/* OF COAL = SPOIL
EMOVEDB REMOVED -
SURFACE ,11. ,,u., '..II, ,,,,, ,,,
. ,. .
. ..II. ..»*•". ,••*'•• .III,. .1., ..." '' .'I'/.. .11, •»"'.
I". • .11,.. ."'• ,11,
.!, •••"-. ,»>/. ' >»< ,.i/. „/ •""•• •
" ':.».•""•• ,>"'/. f' "'• •••""••' '', ADVANCED
" "; " •'
ADVANCED
SPOIL
LINE ~=^
i, .•'".. ..nli.. .„„, >u ..i,, .1
-"'•• •*"•• -'••.,11,.' .,..'' '' ••"-• ••""-
„ .,lfc. .ill/,. •' •• .,„.. • •>"•.. ..i".
* >,,;><• •""'.. •1";jl/ ..'../•.. -"• •'"'...'.. -"•
BOOM-DUMPING^^
POSITION
Jl*>. ..»*?'., ,.»***.. ,\l,. •'
,»W* .. '* ' ii/ '* -i. M*.
.••'•• .«!/ ••>»•. '..-".. •••• .,„
••""-"X .*'"::•....-.. •••"'••«/';;-, .
'"•• .«. .... .«"'.. ,!"/.. , ' „
•-"- •»'• -1-
i,iii,.. jin... ..•"-.. ..in.. •_ ,,;,, „,
, SURFACE
CROSS SECTION
PREVIOUS
SPOIL
Figure 22. Multiseam stripping operation with a shovel.
-------
As shown In Figure 22 the mine is operating with a l60 foot (^9 meter) wide
pit. First the shovel takes a 60 foot (l8 meter) wide section of the parting
exposing the bottom seam. The pit width now is approximately 80 feet (2^
meters). Then, the top seam is uncovered to the side, and a pit width of
70 feet (21 meters) is maintained on the upper level. Coal hauling is done by
eight 12-ton (10.9 metric ton) trucks, loaded by two 10 cubic yard (7-7 cubic
meter) loading shovels.
Multiple Seam Stripping with a Dragline
In the multi-seam mining operation shown in Figures 23 and 2h, a dragline with a
35 cubic yard (26.8 cubic meter) bucket, and a 200 foot (6l meter) boom is used
to uncover the k foot (1.2 meters) top seam. The clay parting between the top
seam and the middle seam, which is about 0.7 feet (0.21 meters) thick, is re-
moved with the help of two dozers and a front-end loader. For removing the
parting to the bottom seam, the dragline operates from the leveled spoil on the
low wall side. In practice, the dragline exposes the top seam the entire pit
length, and then moves to the spoil to uncover the bottom seam. This way coal
recovery can be accomplished from both the seams at the same time and if there
are quality requirements the two coal seams can be blended. Because the over-
burden is unconsolidated and soft, the dragline initially makes the keycut 100
to 150 feet (30.5 to ^6 meters) long to the depth of the top coal seam, and
establishes a safe slope for the future highwall. Because of this, and also
because of the "chopping" operation (Figure 2k), the dragline performance tends
to be poor.
Multiseam Mining with Shovel and Dragline
A shovel dragline combination exposing three coal seams is shown in Figure 25-
The dragline has a 100 cubic yard (76.5 cubic meter) bucket, and a 275 foot
(8^ meter) boom. The 33 cubic yard (25 cubic meter) shovel has a boom length
of 123 feet (37.5 meters) and a dumping radius of 139 feet (U2 meters). The
overburden and the partings are drilled on an approximately 30 by 30 foot
(9 by 9 meter) grid, and shot with ANFO explosive. The shovel removes overburden
to expose the top seam, and the parting between the top and the middle seam, once
the top seam coal is loaded out. The dragline operating from
the spoil removes the parting between the middle and bottom seam. Occasionally,
the dragline may have to rehandle the shovel spoil to maintain the distance betw
between the two machines for uninterrupted stripping. Two, 10 cubic yard (7-7
cubic meter) loading shovels and one front-end loader, alone with eleven trucks,
are used for coal loading and hauling to produce 10,000 tons (9,072 metric tons)
of coal per day.
Summary
The above has been a broad and general introduction to area stripping. The
specific cases illustrate the diversity in the mining methods and equipment
deployment. This section has not said anything about reclamation. It must be
an inherent part of'the method, and not an afterthought. Figure 26 very vividly
illustrates the various stages of mining and reclamation. Proper planning will
permit burying toxic materials, and soil modification at much reduced costs.
This is also important because vegetation cannot be otherwise established, lead-
ing to air and water pollution in subsequent years. (Conclusion of Dr. Ramani's
section.)
-------
100-150'
Long
Keycut
Exposed
4' Thick
Seam
Plan View
Surface
Section View
Figure 23. Multiseam stripping operation with a dragline,
-------
Surface
19.5' Thick
Parting
Exposed 7.5'
Coal Seam
Spoil/
Plan View
Surface
T
50'
•48
.A
8" \
19.5'
22'
\
Leveled Spoil
100-200'
Section View
Figure 2.h. Dragline exposing lowest seam from leveled spoil.
-------
NOTE: SEAMS IN DESCENDING ORDER ARE
No. 13, No. 11 AND No. 9
No. 13
SPOIL
120'
1050B /15',.35,
12(M 3°j-35' 66".72'
55'-60'
t '48"-54'
15'35'
/ 30.-35'
r
55'-60'
• 66"-72'
48"-54'
1—120'
No. 9 SPOIL
I—120'
12"-18"
30'-35'
) 66"-72'
60'
48"-54'
Figure 25. Shovel-dragline tandem operation for multiseam mining.
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Figure 26. Various stages of strip mining and reclamation
In general, the pollution from area mines is not as severe as that from contour
mines. Silt from erosion can often be confined to the mining area. The current
legislative trend is to require restoration of the disturbed area to its
approximate original contour vith all spoil ridges and highwalls eliminated and
no depressions left to accumulate water. Contour grading does not mean that all
areas must be leveled, but rather the profile of the land must be put back to
approximately the way it was before the strip mining began. To accomplish con-
tour grading, the spoil from the first cut is graded so as to blend into the
contour of the adjoining land. Successive spoil piles are then graded with all
materials pushed toward the last cut, where it is deposited in the final pit.
Long slopes on the graded spoil must be interrupted by terraces and/or diversion
ditches. All of the diversions and terraces must be constructed according
to sound engineering principles and must end in suitable outlets.
-------
Several states now require the operator to separate topsoil from the subsoil
and to stockpile the two types separately so they will not be mixed during the
excavation process. When mining is completed, the overburden can then be put
back in its original sequence and revegetated to prevent erosion. Some opera-
tions remove the topsoil and immediately spread it on areas recently graded,
thus handling the material only once. This provision insures that the best
soil for plant growth is on top and not indiscriminately mixed with subsoils.
Some form of tillage of the site "before planting is necessary. Any tillage
measures must follow the contour of the slope and run parallel to the
diversions orterraces. Chemical improvement of the soil in the form of liming
and fertilizers is often needed for rapid establishment of vegetation.
CONTOUR MIKING
Contour strip mining is practiced on rolling to very steep terrain (Figure 27).
The conventional method of mining consists of removing the overburden from
the mineral seam, starting at the outcrop and proceeding around the hillside
(Figure 28). The cut appears as a contour line, thus, the name. Overburden
is cast down the hillside and stacked along the outer edge of the bench
(Figure 29). After the uncovered seam is removed, successive cuts are made
until the depth of the overburden becomes too great for economical recovery
of the coal. Physical limitations of equipment reach, capacity, etc,, may also
determine the strippable limit or cut-off point for mining. Contour mining
creates a shelf or bench on the side of the hill. On the inside it is bordered
by the highwall, ranging in height from a few feet (meters) to more than 100 feet
(30.5 meters); and on the outer side the pit is bordered bv a high ridge of spoil
with a precipitous downslope that is subject to severe erosion and landslides.Be-'
cause of the landslide problem, several states and the Tennessee Valley Authority
have limited the bench width on steep slopes and forbid fill benches on slopes
greater than 33 degrees (see Appendix A-2).
Even with these precautions, landslides still occur. Sediment slides coming
off mining operations have uprooted trees, covered highways, destroyed farm
land, filled up reservoirs and water courses, clogged stream channels,
covered fish-spawning beds, caused flooding of adjacent lands, and destroyed
farm buildings and homes (Figure 30).
Another problem inherent in contour strip mining is the toxic materials (i.e.,
pyrites, acid, soluble minerals, etc,,), in the overburden. During the normal
stripping operation, the high quality overburden near the surface is placed on
the bottom of the spoil pile and then covered with low quality and often toxic
overburden, leaving toxic material exposed to weathering and conversion to
soluble acids and minerals that are carried away by water. For a small extra
cost, however, the high quality overburden can be set aside to cover the toxic
material after grading and/or during excavation. By this means, the toxic
material is not subject to weathering, and pollution can be reduced. More-
over, cover crops are difficult to establish on toxic overburdens, and
therefore erosion damages occur. Erosion serves to prolong the mineral pollu-
tion problem by continuing to reveal new surfaces to weathering. However,
when the toxic material is covered with a good material, cover crops can be
grown to protect the surface.
-------
I
I •
Figure 27. Contour strip mining in Eastern Kentucky.
-------
\n
I. SITE PREPARATION
2. DRILLING & BLASTING OVERBURDEN
3. REMOVAL OF OVERBURDEN
4. EXCAVATING & LOADING COAL
Figure 28. Contour strip mining.
-------
NO DIVERSION
DITCH
TOXIC MATERIAL,
BRUSH & TREES IN FILL SECTION
Note: Downslope is
not scalped
Figure 29- Conventional Contour mining
Che final cut in a contour strip mine can also be troublesome. Materials
idjacent to the coal seam are often toxic. A final cut left uncovered is a
potential pollution source; when it is covered, the danger from this source
Df pollution is reduced or eliminated.
ILghwalls can also lead to pollution problems. An unstable highwall that
sloughs off can ruin the natural drainage in a strip area. Material falling off
;he highwall can dam up channels and thereby prolong the contact between water
and toxic material, or even force the water to seep through toxic spoil piles.
Sloughing highwalls can open up new toxic materials to weathering. Highwall
problems such as these can often be overcome by grading the spoil back against
;he highwall and "knocking off" the top of the highwall.
52
-------
Figure 30. Landslides caused by overloading the fill bench,
-------
Often in the excavation of a strip area, a natural drainageway is cut across.
Unless the water is diverted around the mine workings, the vater enters the mine
area, where it may "become polluted. Problems such as these have been averted
"by not stripping the drainageway or by placing control structures such as drop
boxes and concrete flumes to handle the water.
Diversion ditches with good, controlled outlets should be constructed along the
top of the highwall to keep water out of the workings. Water that does enter
the pit must be properly handled. Strategically located sumps and pumps of
capacity sufficient to discharge the water rapidly through plastic pipe across
the disturbed areas, to natural drainways or to treatment facilities. This can
reduce waterborne pollutant problems downstream. Under some conditions, where a
workable system can be developed, it might be better to catch the water on the
bench and control the discharge to the treatment facilities. Drainage patterns
should be established in the pit to facilitate water removal. Water discharge
from the pit area should be through well-designed outlets and must not overload
the natural drainageway. Proper management of water on the bench can markedly
reduce the siltation and AMD problem
It is critical that all efforts be made to locate underground mines adjacent to
the surface mines. Cutting into abandoned or inactive underground mines can
result in the discharge of large volumes of stored polluted water. The
resultant, continued underground discharges into surface mining works during and
following mining will aggravate the pollution problem. These conditions often
make complete reclamation impossible, and in steep terrain, the underground
mine can supply the water necessary for the development of slippage planes in
the spoils. Where underground mines are adjacent to the proposed surface mines,
barrier pillars should be left. When a deep mine is accidentally breached, the
opening should be sealed as soon as possible by clay compaction, concrete, or
any other method deemed necessary.
Removal and placement of the overburden are critical in environmental control.
The nontoxic, nonacid, and fertile material should be stockpiled for later
spreading or placed on top of the less desirable spoils already mined. The
placement of the spoil -should assure that long, steep slopes are avoided, that
it is not on material subject to slippage, and that it does not produce high
peaks difficult to regrade. In very steep terrain, such as in eastern Kentucky
and southern West Virginia, the spoil should not be placed on the outslope, but
hauled to a fill area designed for that purpose or placed on the bench behind
the operation. The existence 6'f ground water seeps and natural springlines
must be determined prior to spoil placement or slippages may occur.
Contour strip mines disturb an area of the earth's surface much greater than the
area covered by the seam of coal extracted, and have environmental problems not
experienced in area mining. Because of this, concerned Federal and State
agencies along with the coal industry have been working together to develop
mining methods which minimize the adverse effects on the environment while
allowing the maximum recovery of coal. These new methods (slope reduction,
box-cut, head-of-hollow fill, mountain-top removal and block cut) are now
accepted methods of mining on steep slopes. These new methods are not the final
answer for all mining conditions and are being refined as more experience with
varying conditions is gained.
-------
Slope Reduction Method
The slope reduction method was developed on the theory that by reducing the
weight on the fill "bench and spreading the spoil over a large area, it would
be less likely to slide.
7° Storage angle.— The overburden is purposely pushed down and distributed
over the downslope with resultant slope of 7° less than the original slope.
The storage area size is based on the original slope of the mountain. Over-
burden can be removed by either a 1 or 2 cut mining sequence.
Procedures for using the slope reduction method are as follows (See
Figures 31,32, and 33):
1. Scalp all organic material from the top of the highwall to the
predetermined toe of the storage area. This procedure will
insure a solid earth-to^earth bond between the pushed down spoil
and the original surface,
2. Windrow all organic material at the toe of the spoil that will trap
sediment eroding from the outslope.
3. Push overburden from the- first cut beyond the edge of the solid
bench to the toe of the scalped storage area. This material is
placed in 3-foot (.91 meters) compacted layers until the slope
is approximately 7° less than the original slope, measured from
the seam down the hillside. Tables are available indicating the
length of the storage area (see Table 6) (6).
U. Install terraces on the contour during final grading to break up
long slopes and to reduce the velocity of runoff (Figure 3*0- This
procedure reduces erosion and assists in establishing vegetation.
5« Do not disturb the area again after final grading, immediately
revegetate the area, utilizing soil amendments, grasses, and trees.
This mining technique has been accepted as one method of contour mining in
mountainous terrain. EJjr reducing the weight on the fill bench and spreading
the spoil over a larger area, slides have been minimized. Slope reduction
is often the only practical method of reclaiming abandoned contour strip mines
in steep terrain. Its use is not limited to the outslopes on contour strip
mines. It can be used to reduce the slope of any oversteepened spoil pile.
It may be particularly effective for use on steep spoil and tailings slopes
occurring at many western mines.
Parallel fill,— This method is a modification of the slope reduction method
and has no storage angle. Overburden is pushed down the slope and compacted
in three foot (.91 meters) layers at the same angle as the original slope
(see Figures 35 and 36"). The depth of fill is determined from tables according
to the degree of original slopevT).
55
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1st STEP (27° EXAMPLE)
FIRST CUT AND SPOIL
— HIGHWALL
1st
.OUTCROP
PROCEDURE:
1. SCALP FROM TOP OF 2nd CUT HIGHWALL TO TOE OF FILL.
2. REMOVE SPOIL FROMlst CUT AND PUSH DOWN SLOPE.
3. SPREAD SPOIL AND COMPACT IN LAYERS
UNTIL STORAGE ANGLE IS REACHED.
4. LEAVE AT LEAST 15'BARRIER.
5. PICK UP COAL.
DIVERSION
DITCH
2nd STEP (27° EXAMPLE)
SECOND CUT AN& SPOIL
REDUCED SLOPE
LOWER HALF
PROCEDURE:
1. REMOVE AND STACK SPOIL FROM 2nd CUT.
2. PICK UP COAL.
3. AUGER IF PERMITTED.
TOE
OF FILL
Figure 31. Slope reduction method, steps 1 and 2.
-------
DIVERSION
DITCH
3rd STEP (27° EXAMPLE)
FINAL GRADING (ONE AND TWO CUT METHOD)
REDUCED SLOPE
LOWER HALF
BARRIER
PROCEDURE:
1. COMPACT SUITABLE SPOIL IN AND ABOVE AUGER HOLES.
2. PUSH STACKED SPOIL AGAINST HIGHWALL.
3. SLOPE BENCH TO SPECIFIED GRADE.
4. AT LEAST 15' OF BARRIER IS LEFT INTACT.
TOE
OF FILL
DIVERSION
DITCH
Figure 32. Slope reduction method, step 3.
ONE CUT ONLY (27° EXAMPLE)
COAL
CUT SECTION
PIT-
SEAM
'OUTCROP
^\
REDUCED SLOPE
LOWER HALF
BARRIER
PROCEDURE:
1. SCALP FROM TOP OF HIGHWALL TO TOE OF FILL.
2. REMOVE APPROXIMATELY .75% OF THE CUT SECTION
AND PUSH DOWN SLOPE.
3. SPREAD SPOIL AND COMPACT IN LAYERS UNTIL
STORAGE ANGLE IS REACHED.
\
TOE
OF FILL
4. REMOVE REMAINING 25% OF CUT SECTION
AND STACK ON UPPER Vi OF REDUCED SLOPE.
5. LEAVE AT LEAST 15' BARRIER.
6. PICK UP COAL.
7. AUGER IF PERMITTED.
9. GRADE AREA SAME AS FOR 2 CUT METHOD.
Figure 33. Slope reduction method, steps 1 and 2, one cut only.
57
-------
Table 6, SLOPE REDUCTION (EXAMPLE)*
Bench width (feet) Length of Length of
Length from top
of highwall to
toe of fill (feet)
Linear feet of
bench per
acre
One cut
only
6U
r<
88
100
112
1st cut
of 2 cuts
60
TO
80
90
reduced
slope (feet)
98
118
138
157
177
outslope
(feet)
71
82
98
112
128
One cut
only
213
252
296
337
381
1st cut
of 2 cuts
199
237
278
317
359
One cut
only
205
173
ll*7
129
llU
1st cut
of 2 cut!
219
181*
157
137
121
"Original ground slope, 27°; reduced slope, 20°.
foot = 0.30U meters; acre = O.UO hectares
Source: Reference 6 at the end of this section.
Figure 3^. Slope reduction method, ©utslope terraced and revegetated,
-------
1st STEP (27° EXAMPLE)
I
2nd CUT
X
o
PIT - 50'—H=
IstCUT **-
'PIT-100"
PROCEDURE:
1. SCALP FROM TOP OF 2nd CUT HIGHWALL TO TOE OF FILL.
2. REMOVE SPOIL FROM 1st CUT AND PUSH DOWNSLOPE.
3. SPREAD SPOIL AND COMPACT IN 3' LIFTS OR LAYERS
UNTIL MAXIMUM DEPTH IS REACHED FOR THAT DEGREE OF
ORIGINAL GROUND SLOPE.
4. LEAVE AT LEAST IS' BARRIER.
5. PICK UP COAL.
ANGLE OF
REPOSE
DIVERSION
DITCH
2nd STEP (27° EXAMPLE)
1
x
o
I
-•PIT-SO'
2nd CUT
SPOIL
, ROAD
" ••••i^^^^^k.
PIT-100'
•OUTCROP
CARRIER
PROCEDURE:
1. REMOVE AND STACK SPOIL. FROM 2nd CUT.
2. PICK UP COAL.
3. AUGER IF PERMITTED.
ANGLE
OF REPOSE
Figure 35. Parallel fill method, modified slope reduction, steps 1 and 2.
-------
3rd STEP (27° EXAMPLE)
PROCEDURE:
1. COMPACT SUITABLE SPOIL IN AND ABOVE AUGER HOLES.
2. PUSH SPOIL FROM 2nd CUT AGAINST HIGHWALL.
3. SLOPE BENCH TO SPECIFIED GRADE.
4. AT LEAST 15' OF BARRIER IS LEFT INTACT.
5. ROAD ON EDGE OF FILL BENCH IS NOT DISTURBED.
ANGLE
OF REPOSE
Figure 36. Parallel fill method, modified slope reduction, step 3.
Although parallel fill is still in the experimental stage, it may prove to be
more successful than the storage angle method. No slides have developed,
primarily because of the better friction plane which is more slide resistant.
Legislation at both the State and Federal level is becoming more stringent and
making it illegal to push overburden beyond the solid edge of the bench and over
the downslope. This type of restriction will ban the slope reduction method of
mining. However, the theory of slope reduction has an interesting offshoot
now being practiced by operators as an emergency measure when spoil begins to
slide from the outslope. Bulldozers and/or pans are used to reduce the slide at
its mid-section. The resulting profile approximates that of the alope reduction
method. Such an emergency measure is one practical and effective way to stop
slides at an early stage when telltale tension cracks appear at the crest of the
outslope(8).
Box-Cut Method, Two-Cut
The box-cut is one of the conventional eontour strip mining methods. A box-cut
is created by leaving an undisturbed section of the surface measured from the
outer edge of the solid bench back toward the highwall. This barrier is at least
least 15 feet (U.56 meters) in width and provides a solid foundation on which to
deposit spoil. It also helps to prevent water from running off the bench and
percolating into the spoil on the downslope.
60
-------
Basically, the two-r-cut box-cut method reverses the usual box-cut method by
recovering the coal from the second cut first. This method was developed to
prevent overloading the fill bench with second cut spoil and to make a more
stable outslope.
Procedures to follow: (See Figures 37 and 38).
1. Scalp entire area from top of highwall to toe of the outslope.
2. Drill and shoot the overburden.
3. Remove overburden from shot area to a point approximately 15 feet
(U.56 meters) above the coal seam, making a flat bench from high-
wall to lip of spoil on the downslope.
h. Establish the permanent haul road on the outer edge of the
bench. This road is located on the solid bench, if space permits,
and will not be disturbed in future mining.
5. Uncover the inside half of coal for the first cut. Stack the
overburden on the flat bench between the road and the low-wall
side of the first pit (Figure 39). After the coal is picked up
and augered, push the stacked overburden into' the pit.
6. Uncover the outside half of the coal, stacking overburden against
the highwall. Recover marketable coal, leaving the 15-foot
(U.56 meters) barrier intact.
7. Push spoil back into pit and slope bench to specified grade,
leaving road on the outside undisturbed.
This method reduces the amount of overburden on the downslope, thereby reducing
the incidence of slides and speeding up the final grading of the operation.
However, the two-cut box-cut method places spoil on the downslope and will be
illegal in the future if pending legislation is passed that bans a fill section
beyond the edge of the solid bench.
Head-of-Hollow Fill Method
The head-of-hollow fill method was developed to improve aesthetics, reduce
landslides, allow for full recovery of one or more coal seams, and produce
potentially valuable flat to rolling mountain top land that is suitable for
many uses other than forestry.
The head-of-hollow fill method provides storage space for spoil from the
removal of entire mountain tops and is also used as a waste area for overburden
from contour benches. In the past, as the top coal seams were worked on the
contour with a rim cut, islands of mountain land were left with-no access. Many
of these isolated areas of land left from previous mining operations are
now being removed.
6l
-------
SOLID BENCH
FILL BENCH
10' MINIMUM
SEAM
OUTCROP
PROCEDURE:
1. SCALP FROM POINT A TO POINT B.
2.'MAKE CUT A C D .
3. PLACE SPOIL FROM A C D IN D E B .
4. ESTABLISH ROAD AT POINT E ON FILL BENCH
5. SOLID BENCH - POINT C TO POINT D
6. FILL BENCH - POINT D TO POINT E
DIVERSION
DITCH
2nd STEP
V,
\
TOE
OF FILL
-HIGHWALL
1st PIT
PROCEDURE:
1. REMOVE AND STACK SPOIL FROM 1st PIT.
PIT WIDTH IS 1/3 OF TOTAL BENCH -
(SOLID BENCH PLUS FILL BENCH)
2. PICK UP COAL
3. AUGER IF PERMITTED.
OUTCROP
Figure 37. Box-cut method (two cut), steps 1 and 2.
62
-------
•OUTCROP
'BARRIER
PROCEDURE:
1. COMPACT SUITABLE SPOIL IN AND ABOVE AUGER HOLES.
2. PUSH SPOIL AGAINST HIGHWALL AND UNCOVER COAL IN 2nd PIT.
STACK ANY EXCESS BETWEEN ROAD AND PIT.
3. LEAVE AT LEAST 15' BARRIER.
4. PICK UP COAL.
V
TOE
OF FILL
DIVERSION
DITCH
4th STEP
ROAD
OUTCROP
BARRIER
PROCEDURE:
1. PUSH SPOIL INTO 2nd PIT.
2. SLOPE BENCH TO SPECIFIED GRADE.
3. AT LEAST 15' OF BARRIER IS LEFT INTACT.
4. ROAD ON EDGE OF FILL BENCH IS NOT DISTURBED.
\
TOE
OF FILL
Figure 38. Box-cut method (two-cut), steps 3 and U.
63
-------
''*/. 4 ' ' t.«i*M /
^It^C^fTr
Figure 39- Box-cut method (two-cut), step 2.
Narrov V-shaped, steep-sided valleys that are near the ridge top, and are free
of underground mine openings , seeps or wet weather springs are selected for
filling. The size of the selected valley must be such that the overburden
generated by the mining operation will completely fill the treated head of
hollow (valley).
Procedures to follow (See Figure
1. Scalp the vegetative cover from the area on which the spoil is to be
deposited.
2. Remove and store topsoil.
3. Build French drains in all natural drainways that have been deepened
by bulldozers, forming a continuous chain from the upper end of the
valley at the mined bench, down to a point several feet below the toe
of the base fill layer. These rock drains will provide for internal
drainage of the fill and allow any water to percolate out instead of
saturating the spoil and causing slides. The main drainway should be
a minimum of 15 feet (U.56 meters) in width and composed of rock with
a minimum dimension of 12 inches (30.U8 centimeters).
-
-------
PROCEDURE:
1.SCALP ENTIRE AREA THAT WILL BE COVERED WITH FILL. REMOVE AND STORE TOPSOIL.
2.CONSTRUCT FRENCH DRAINS IN THE HOLLOW WATER COURSES.
3.BUILD THE FILL IN COMPACTED LAYERS.
FACE OF FILL NO STEEPER THAN 2:1.
4.CONSTRUCT CROWNED TERRACES EVERY 20 FEET,
APPROXIMATELY 20 FEET WIDE.
5.CENTER OF COMPLETED FILL BENCH IS CROWNED
TOWARD THE HIGHWALL. SO THAT WATER DCIKI/- nrn«wr~
WILL FLOW ONTO EXCAVATED BENCHES. BEING REMOVED
6.BUILD SILT CONTROL STRUCTURES BELOW HOLLOW FILL.
MOUNTAIN TOP
CROWNED FILL BENCH
TOPSOIL
CROWNED
TERRACES
LATERAL
DRAIN
ROCK FILLED ,(FRENCH DRAIN),
NATURAL DRAIN WAY
Figure
. Head-of-hollow fill.
U. After internal drainage is provided, the fill is placed in compacted
lifts or layers "beginning at the toe of the fill. All material is
deposited in uniform horizontal layers parallel with the proposed
final grade and is compacted with haulage equipment. The thickness
of the layers should not exceed the maximum size of the rock used
as fill material and in any case not be over four feet (1.2 meters).
Layering continues until the top of the fill is slightly higher
than the established bench level remaining after the coal has been
removed. This slope should be no greater than 3 percent^(Figure
5. The center of the completed fill is crowned so that drainage will
be toward the highwall or bench level adjacent to it and then to a
safe outlet away from the toe of the fill.
6. The face of the fill resembles stair steps progressing from the base
layer to the top of the fill. Each layer is a slightly crowned
terrace that provides drainage to undisturbed land. The outer slope
should be no steeper than 2 horizontal to 1 verticle.
T. Check dams or silt control structures should be built downstream
from the hollow fill.
8. Revegetation of the hollow fill face should progress as the fill
height increases; hydroseeding is a preferred method.
-------
Figure U)b. Head-of-hollov fill,
If constructed according to design, stability of the fill can be expected. The
horizontal and vertical pressures should provide adequate friction to prevent
a failure in the fill. Several head-of-hollow fills have passed through five
winters with no slides and little or no erosion.
Instead of miles of unstable outslope, with its potential for slides and erosion,
or islands of isolated land with no access, a large, stable, fairly level
area can be constructed with this method.
Some operators have graded the face of the fill to approximately 22° from the
horizontal, eliminating the crowned terraces. By mulching and revegetating
immediately after grading, erosion has been held to a minimum. However, it has
been found that' long slopes must be interrupted with diversion ditches to con-
trol surface runoff and excessive erosion. These diversions should be installed
at a minimum of every 50 feet (15.2 meters) in vertical height of the fill.
Flat ridges, depressions and old abandoned strip pitc that commonly occur in
Appalachia, are also used for storing spoil. These areas are particularly useful
when starting a new operation.
-------
Multiple-Seam Mining
Recoverable coal seams often lie close together. Multiple-seam mining is the
method in which more than one coal seam is strip mined at one time. This
method is desirable, as all seams are mined in one systematic operation and it is
not necessary to return at a later date and disturb the watershed again.
Method no. 1.— If the overburden from the upper seam will not reach the bench
of the lower seam, treat each seam as a separate mining operation, mining the
lower seam first. This bench may be used to store spoil produced during
stripping of the upper seam.
Method no. 2.— If the overburden from the upper seam will reach the bench of
the lower seam, mine the lower seam in advance of the seam above. Grading
should be delayed on the lower bench in order to catch big rocks from the upper
seam and bury them in the pit. In no instance can spoil from the upper seam
extend more than one-half the distance from the highwall to the edge of the
solid bench of the lower seam.
Method no. 3.— If both seams appear in the same highwall, separated by more
than 25 feet (7-6 meters), and two or more cuts are planned, the coal should be
recovered from the bottom seam first (Figure Ul). If the seams are separated by
less than 25 feet (1.6 meters), mine from the upper seam down, recovering both
seams in one systematic operation (Figure U2, Steps 1 and 2). Lateral movement
of the spoil is recommended.
Figure Ul. Multiple Seam Mining: Two seams more than 25 feet apart
-------
MINE UPPER COAL SEAM FIRST
MOUNTAIN
HIGHWALL NO. 1
1st CUT
PARTING LESS THAN 25 FEET
ORIGINAL
GROUND
SLOPE
Figure 1+2, Multiple seam mining method:
Two seams less than 25 feet apart in
the same highwall, step 1.
MINE LOWER COAL SEAM
MOUNTAIN
OVERBURDEN
COAL SEAM
PARTING LESS THAN 25 FT.
COAL SEAM
HIGHWALL
COMPLETED
FOR 1st CUT
ORIGINAL
GROUND
SLOPE
Figure h2. Multiple seam mining method;
Two seams less than 25 feet apart in
the same highwall, step 2.
68
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Mountain-Top Removal Method
The mountain-top removal method of surface mining is an adaptation of area mining
to contour mining for rolling to steep terrain. Where coal seams lie near tops
of mountains, ridges, knots, or knolls, they can usually be economically strip
mined. The entire tops are removed down to the coal seam in a series of
parallel cuts. Excess overburden that cannot be retained on the mined area
is transported to head-of-hollow fills, stored on ridges, or placed in natural
depressions. This mining method produces large plateaus of level, rolling land
that may have great value in mountainous regions (Figure
Cannelton Industries, Incorporated, is mining 2,010 acres (8l2 hectares),
25 miles (30 kilometers) from Charleston, West Virginia. Three premium coal
seams are being surface mined using the mountain-top removal method. Over-
burden averages 110 feet (33. hk meters) over most of the property but ranges up
to 29^ feet (89.3 meters) on the highest point of the ridge. In filling up the
voids and leveling off the top of the mountain, .Cannelton is creating flat land
that at one point contains a straight stretch of 7,000 feet (2,128 meters).
The potential new land-use area created by this plateau when mining is finished
could accommodate a city of no less than 20,000 people, according to the
Community Planning Section of West Virginia TechT9).
Many of the coal seams that lie high on the mountain cannot often be recovered
by underground mining. Extreme surface subsidence, unsafe roof conditions,
and the narrowness of the coal seams make these coal reserves recoverable only
by mountain-top removal.
Procedures for using mountain-top removal method:
1. Select and prepare the hollows that will be used to store excess
spoil (see Head-of-Hollow Fill). If ridges and natural depressions
are to be used for spoil storage, they must be scalped of all organic
matter and topsoil must be removed for later covering of graded areas .
2. The first cut is stripped as a box cut, leaving at least a 15-foot
(h.56 meter) barrier of coal bloom undisturbed (Figure kb). This cut
is made roughly parallel to the ridge. The barrier will serve as a
notch to support the toe of the backfilled overburden from successive
cuts. Overburden from the first cut is transported to the predeter-
mined storage area.
BARRIER
TOP SOIL
FLAT TO ROLLING LAND
BARRIER
BLOSSOM BLOSSOM
t
DIVERSION DITCH Fig[3re U3 Mountain-top removal method: DIVERSION DITCH
Mountain top after final grading and topsoiling
69
-------
MOUNTAIN TOP
FIRST CUT
(BOX CUT)
HIGHWALL
BARRIER
BLOSSOM
Figure UH. Mountain-top removal method:
First cut (box cut).
3. Once the first cut is completed, a second cut is made parallel to the
first (Figure ^5). However, the overburden from the succeeding cuts
is deposited in the cut just previously excavated. The mountain top
is thus reduced by a series of cuts parallel to the ridge line
(Figure U6). Approximately 50% of the overburden would be transported
to storage areas for disposal, and none would be pushed over the
downslope. The mountain-top removal method can also be used by
working around the mountain ridge from one side to the other.
k. When mining is completed, the mountain top is completely covered
with a 20- to UO-foot (6- to 12-meter) layer of spoil and is graded
nearly flat (Figure hja and Hfb).
5. At least a 6-inch (15.3^ centimeter) layer of topsoil is spread
over the entire graded area.
Benefits and advantages of using the mountain-top removal method have been
demonstrated at producing mines in -various states and are as follows:
1. Coal is recovered from areas that would not be mined because they are
unsuitable for underground mining. Since all the coal is recovered,
the reclaimed area will not be disturbed again by future mining.
2. The method creates large, flat to rolling areas that are vitally
needed in. mountainous regions. The end result has an enormous
post-mining land use potential when properly completed t
70
-------
SECOND CUT
MOUNTAIN TOP
SECOND
ORIGINAL
GROUND
SLOPE
CUT
HIGHWALL
SPOIL
BARRIER
BLOSSOM
Figure 1*5. Mountain-top removal method: Second cut.
BRUSH DAM
FOURTH CUT
MOUNTAIN TOP
BARRIER
Figure k6. Mountain-top removal method: Fourth cut.
71
-------
BRUSH DAM
BARRIER
ro
FLAT TO ROLLING LAND
DIVERSION
DITCH
HOLLOW
DIVERSION
DITCH
Figure UTa, Mountain-top removal method:
Mountain top after final grading and topsoiling.
-------
Figure Vfb. Mountain-top removal method:
fountain top after final grading and topsoiling.
-------
3. Spoil has "been totally eliminated on the downslope. Since no fill
bench is produced, landslides are eliminated,
h. Mined area is completely backfilled and is more acceptable
aesthetically, as no highwall is left.
5. Size of the drainage system is smaller and the number of sediment
control structures have been reduced. Erosion is easily controlled
because of the low velocity and quantity of surface water runoff.
6. Overburden is easily segregated, topsoil can be saved, and toxic
material can be deeply buried.
Disadvantages of mountain-top removal are:
1. Detailed topographic maps must be available if proper preplanning is
to be accomplished. Before mining begins the final spoil thickness
above the bottom of the coal pit must be estimated. If the estimate is
low, then pits must be narrowed, and in some instances the operation
will become spoil bound. The result of underestimating is unnecessary
double handling of spoil material, which increases cost and ties up
the earth-moving equipment.
2. Investment costs for spoil haulage equipment are increased.
3. Special precautions must be taken in scheduling the various phases
of mining so as to realize maximum production and eliminate dead
time.
Block-Cut Method
The Block-cut method (haul back, pit storage, put and take, etc.) is a simple
innovation of the conventional contour strip mining method for steep terrain
(See Figure 1*8). Instead of casting the overburden from above the coal seam
down the hillside, it is hauled back and placed in the pit of the previous cut.
The method is not new and is known by various names, depending on the locality.
Basically, the operational procedures are similar in that no spoil is deposited
on the downslope below the coal seam, topsoil is saved, overburden is removed
in blocks and deposited in prior cuts, the outcrop barrier is left intact, and
reclamation is integrated with mining (Figures ^9 and 50).
When beginning the mine, a block of overburden is removed down to the coal seam
and disposed of (Figure h&). This first cut spoil can be placed above the high-
wall in some instances, or spread along the downslope as in conventional contour
mining, or moved laterally and deposited in a head-of-hollow fill or ridge fill.
The original cut is made into the hillside to the maximum depth that is to be
-------
TOP OF RIDGE
-HIGHWALL-
CUT 7
CUT 5 CUT 3 CUT 1 CUT 2 CUT 4
-OUTCROP BARRIER-
HOLLOW
PROCEDURE:'
l.SCALP FROM TOP OF HIGHWAIL TO OUTCROP BARRIER
REMOVE AND STORE TOPSOIL.
2.REMOVE AND DISPOSE OF OVERBURDEN FROM CUT 1.
3.PICK UP COAL, LEAVING AT LEAST A 15 FOOT UNDISTURBED
OUTCROP BARRIER.
4.MAKE SUCCESIVE CUTS AS NUMBERED.
5.OVERBURDEN IS MOVED IN THE DIRECTION, AS SHOWN BY
ARROWS, AND PLACED IN THE ADJACENT PIT.
6.COMPLETE BACKFILL AND GRADING TO THE APPROXIMATE
ORIGINAL CONTOUR.
Figure U8. Block-cut method.
CUT 6
mined. The width is generally three time that of tho following cuts. After
the coal is removed, the overburden from the second cut is placed in the first
pit and the coal from the second cut is removed. This process is repeated as
mining progresses around the mountain. Once the original cut has been made,
mining can be continuous, working in both directions around the hill or in only
one direction.
The cuts are mined as units, thereby making it easier to retain the original
slope and shape of the mountain after mining. In all cuts, an unmined outcrop
barrier is left to serve as a notch to support the toe of the backfilled over-
burden. Block-cut mining makes it possible to mine on slopes steeper than those
being mined at present without the danger of slides and with minimal disturbance.
Approximately 60% less total acreage is disturbed than by other mining techni-
ques now in use. There is significant visual evidence that the block cut method
is less damaging than the old practice of shoving overburden down the side of
the mountain resulting in permanent scars on the landscape. The treeline below
the mined area and above the highwall is preserved. Results of the mining
operation generally are hidden and cannot be seen from the valley below. This
cosmetic feature Is only one of the advantages that contribute to making this
an acceptable steep-slope mining method. There are several references on
Block-Cut Method (l,8,10-15).
75
-------
RIDGE TOP
Figure 1*9- Block-cut method: Stripping phase.
RIDGE TOP
HOLLOW
OMPACTED
CLAY
BARRIER
Figure 50. Block-cut method: Backfilling phase.
76
-------
Using hypotehtical costs, SecorClO}., calculated, that under Pennsylvania lav,
where backfilling must be to the original contour, the block-cut method cost .
33 cents per ton less than the conventional method. He presumes that the lover
cost vas due to the fact that conventional pull-back methods involve double
handling of spoil material. Secor cautions that although the block cut method
is no more expensive and may be less than conventional dragline pull-back
mining, these costs are estimates only and can vary from operation to operation.
Existing or pending State and Federal legislation makes it illegal to push
overburden beyond the outcrop and over the mountainside and thus bans the
conventional type of contour strip mining. Hovever, the block cut or similar
methods meet the criteria of this nev legislation and allov for recovery of
coal reserves in mountainous regions that vould otherwise be unmineable.
West Virginia Reclamation Chief, Benjamin C. Greene has stated the follov-
ing about the block-cut method: "As far as ve're concerned it's the vay of
the future if ve are to continue contour surface mining. . . . The environmental
effects are very minimal and can be totally controlled by this mining method."
The block-cut method is no longer experimental and is nov operational in
several States. Enough information is available from active operations to
shov this method to be potentially feasible from an economic and environmental
standpoint .
Benefits and advantages of the block-cut method over conventional contour
strip-mining have been demonstrated at producing mines under varying conditions
and are:
1. Spoil on the dovnslope is totally eliminated. Since no fill bench is
produced, landslides have been eliminated.
2. Mined area is completely backfilled, and since no highvall is left,
the area is aesthetically more pleasing.
3. Acreage disturbed is approximately 60% less than that disturbed by
conventional contour mining.
U. Reclamation costs are lover, as the overburden is handled only
once instead of tvo or three times.
5. Slope is not a limiting factor.
6. The block-cut method is applicable to multi-seam mining.
7. At present, this method does not require the development of nev
equipment. As nev mining technology develops, hovever, modified or
nev types of equipment may be needed.
8. Regular explosives are used, but blasting techniques had to be develop-
ed to keep shot material o.n the permit area.
9- Bonding amounts and acreage fees have been reduced.
77
-------
10. Size of the disturbed area drainage system is smaller.
11. Size and number of sediment control structures nave "been reduced.
Total life of structure usefulness is increased,
12. No new safety hazards have "been introduced. However, with the
increased number of pieces of moving equipment in a more confined
area may negate this point.
13. Revegetation costs have been considerably reduced and it is easier
to keep the seeding current with the mining. Bond releases are
quicker,
lH. AMD siltation, and erosion is significantly reduced and more
easily controlled "because of concurrent reclamation with mining.
15. Total amount of coal recovered is equal to that recovered by
conventional methods.
16. Overburden is easily segregated, topsoil can be saved, and toxic
materials can be deeply buried.
17. Equipment, materials, and manpower are concentrated, making for a
more efficient operation.
18. The method allows for early removal of equipment from the operation
and placing it back in production at another site.
Disadvantages of the block-cut method are:
1. Complicated and time-consuming methods of drilling and blasting
to maintain control of the overburden and get proper fragmentation
for the particular types of equipment being used in spoil removal.
2. Economics may limit use of this method; i.e., thin seams of steam
coal cannot be recovered profitably if the overburden must be shot.
3. Special precautions must be taken in scheduling the various phases
of mining and reclamation so as to realize the maximum recovery of
coal and at the same time eliminate any dead time for equipment.
k. It is very important that the location of the initial box cut be
properly selected. In some areas there will be no place to back
haul the material taken at the "beginning of the block cut or to
dispose of the excess spoil at the end of the operation. Head-of-
hollow fill is not always possible, as it can only be done in a
restricted set of circumstances.
5. Long-term environmental consequences are not known and will require
a monitor program of a pilot block-cut operation to determine if
stream siltation and mineralization can be eliminated.
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6, Investment costs for spoil haulage equipment are increased. Some
small mines cannot afford this additional expense,
7. The "block-cut method develops no "broad bench that has a high land
use potential in mountainous terrain. Ho access is left for forest
firefighting crevs, timbering operations, or recreational purposes.
8. Augering must "be conducted concurrently vith mining.
Perhaps the most salient feature of block cutting is that the removal of the
overburden and the reforming of the original contour by backfilling are integral
processes (Figures 51,52 and 53). As a result, the method tends to reduce many
of the associated environmental impacts that occur by other methods. This new
mining technique has been accepted as one of the most significant break-
throughs made in contour mining in mountainous terrain.
STEP 1
REMOVE TIMBER AND CUT
TRENCH TO CATCH
[ROLLING STONES,
STEP 2
t ~
INITIAL DOZER CUT
TO MAKE DRILL BENCH
STEP 3
DRILL BENCH IS SHOT
AND HAULED BACK
TO BACKFILL
BARRIER
X/l
Figure 51. Block-cut method:
Controlled placement of spoil, steps JL, 2, and 3.
79
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STEP 4
HAUL ROAD
AND DRAINAGE
DITCH IS BUILT ALONG
UNCOVERED COAL
STEP 5
REMOVE UNCOVERED
COAL AND AUGER.
,FILL HOLES WITH
.COMPACTED CLAY.
COMPACTED
CLAY
IZI-t-AUGER HOLE
STEP 6
BACKFILL & REVEGETATE
SLOPE BENCH
TOWARD HIGHWALL
Figure 52. Block-cut method:
Controlled placement of spoil, steps ht 5, and 6.
Auger Mining
Auger mining (Figure 5*0 is usually associated with contour strip mining. It
is common practice to recover additional tonnage after the coal/overburden ratio
has become too small to render further contour strip mining economical. When
the slope is too steep for contour mining, augering is often performed directly
into the hillside from a narrow "bench. Augers are also used to recover coal
near the outcrop that could not be extracted safely by underground mining.
Augering is a method of producing coal by boring horizontally into the seam,
80
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**' -.-
Figure 53. Block-cut mining in West Virginia.
much like a carpenter bores a hole in wood. The coal is extracted in the same
manner that shavings are produced "by the carpenter's bit. Cutting head of
augers are as large as seven feet (2.12 meters) in diameter. By adding sections
behind the cutting head, holes may be drilled in excess of 200 feet (60.8 meters)
deep. Augering by itself disturbs less surface area than either contour or
area mining, but it poses problems that are more critical, such as very poor
resource recovery and providing access to underground mines for the entrance or
exist of water. This water may be a prime source of AMD.
Theoretically, augering should recover considerably more of the coal seam than
at present. It should be possible to drill longer holes with diameters nearly
equal to the thickness of the coal seam, and the openings should be drilled so
that little or no coal remains unmined between holes. This theory assumes coal
seams of constant thickness and regularity, without undulations; but such is not
usually the case.
81
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Figure 5^. Auger mining following strip mining.
Present angering equipment drills holes that sag gradually downward, eventually
through the bottom of the coal seam into geologic formations beneath. In
actual practice, each hole is drilled about 30% undersize to allow for the
downward leaning of the hole—sagging caused by bending from the weight of the
column of auger steel as it advances into the mountainside. Holes also begin
near the top of the coal seam to allow for sagging (Figure 55)^ '•
In practice, there are additional amounts of coal left unmined between drill
holes because holes are often not parallel. For example, when the highwall is
not a straight line, which is usually the case, there are pie-shaped blocks of
the coal seam untouched by auger holes. Figure 56 illustrates that condition'°)
Wherever auger mining has been used to recover coal, the holes must be plugged.
The objective is to prevent the flow of water in or out of the holes and to
inhibit oxidation of the coal that was not recovered. If suitable material is
compacted in each hole to a minimum depth of at least 6 feet (1.2 meters), AMD
-------
LONGITUDINAL SECTION OF AN AUGER HOLE
HIGH
WALL
HOLE DIAMETER = 2/3 X
"•^^•^M
AUGER HOLE
COAL SEAM-
SPACING OF AUGER
HOLES DRILLED FROM THE HIGHWALL
Note: Unmined coal is left around
— holes and wasted.
II <
X Q
1/6 X
Figure 55. Auger hole section and spacing
and seepage problems similar to deep mine openings can be eliminated or
minimized. In multi-seam operations, the auger holes in each seam must be
plugged. The exposed face of the coal seam, at the highwall, should be
covered with selected backfill material and compacted at least 5 feet (.1.5
meters) above the top of the holes.
Backfilling of all auger areas should be to the approximate original contour,
or all highwalls should be reduced to a slope of 35° or less. If the^operation
is below drainage, a water impoundment may be granted for the final pit as an
alternative plan for backfilling.
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UNMINED-
_ CENTER LINE OF
AUGER HOLES
UNMINED
Figure 56. Plan of auger holes drilled in the
coal seam from a curving highwall.
Minimal Overburden-Moving Mining Methods
With the exception of auger mining, all surface mining methods previously
discussed depend on removing massive quantities of overburden to recover the
coal. Some underground mining techniques and machinery may possibly be
adapted for surface mining of coal at shallow depths. Coal companies are
interested in new ideas for extracting coal from a highwall without moving
overburden and without sending men underground.
Highwall mining method.— Highwall mining is an automated variation of an
underground mine cutting machine worked through the highwall following the
stripping. It has been used only to a limited extent and needs further
development to eliminate operational problems, The cutting machines are
remotely contolled continuous miners designed to enter highwalls and remove coal
up to 1,000 feet (SOU meters) in depth at a rate of 3,odo tons (2,721 metric
tons) per day. Hew entries are made at predetermined intervals along the
outcrop until the end of the property is reached.
At the present time, highwall mining using continuous miners is not considered
feasible. However, technology has been developed that warrants further research,
and chances for success are good.
81*
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Longwall mining method.— Longvrall mining is a method of coal recovery that
allows the roof to be temporarily held up "by jacks and then allowed to subside
after the coal has "been extracted. This method has been used successfully both
in this country and abroad where deep competent cover exists.
The concept of applying underground longwall mining equipment to surface mining
under relatively shallow cover was developed by the U.S. Environmental Protection
Agency (EPA) as a possible alternative to conventional strip mining. This
shallow-covered coal could be mined without disturbing the overlying vegetation,
all the coal could be recovered,and environmental problems such as uncontrolled
subsidence and AMD would be greatly reduced. EPA feels that terrain is not a
limiting factor (Figure 57), but unconsolidated roof conditions could preclude
longwall mining.
HILL AND VALLEY
BENCH
BENCH
LEVEL
BENCH
ISOLATED ELEVATION
=Z-EE™=Ef=ErEErzjr:a BENCH
Figure 57- Various types of terrain applicable
to the longwall stripping system.
85
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The idea is to work the coaj, cutting and remova,! equipment from a narrow bench.
This equipment would operate back and forth along a wide coal face accompanied
by self-moving jacks to prevent the overburden that subsides behind the opera-
tion from binding the cutting machine.
The theory of strata control for longwall stripping should be similar to that
employed in conventional longwall mining underground. That is, the immediate
roof strata above the coal must be supported and allowed to cave in a manner
that allows controlled support and caving of the upper strata. The desired
sequence of events that will take place as the longwall face advances would
be: l) the immediate roof is relieved of the load of the upper overburden;
2) the immediate roof sags away from the stronger, higher strata; 3) the chocks
advance and cause caving to occur with a breaker line formed at the rear of the
chocks; U) the caved material expands to fill the void in the mined area and
the upper roof, forming a span between the gob material and a line where the
immediate roof has separated from the upper roof over and near the advancing
wall face; and 5) most of the roof pressure taken by the solid coal ahead of
the advancing face and the gob and the supports merely maintain the relatively
light load of the immediate roof(l6).
One requirement the EPA placed on the feasibility study was that standard off-
the-shelf longwall equipment had to be used. It is possible that existing
equipment will have to be modified or new equipment developed.
Potential advantages of longwall mining are:
1. Abandoned surface mines can be reopened with little or no additional
land disturbance.
2. Coal that might not otherwise be mined will be recovered.
3. Longwall mining will work well with other surface mining methods.
k. Total resource recovery is possible.
5- The need to overturn the entire earth surface to recover the coal
is eliminated.
6. Landslides are eliminated,
7. Sediment and erosion problems are substantially reduced.
8. Filling the voids left by removing the coal will reduce AMD, a major
problem of underground mining.
9, Subsidence can be controlled.
86
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Potential disadvantages of longwall mining are:
1. Mining method is not perfected,
2. Expensive modification to existing equipment or development of new
equipment may be necessary.
3. Small operators will probably not be able to afford the cost of
longwall mining equipment.
k. Subsidence could disrupt numerous acquifers and alter underground
water patterns.
5. Subsidence could allow air to contact near surface coal seams
creating spontaneous combustion problems. This is especially true in
the lignite and sub-bituminous coal regions,
6. A soft roof or bottom or a too-strong top that will not cave properly
could preclude longwall mining.
T. Outby control of the highwall is necessary to prevent slides.
SURFACE MINING EQUIPMENT
Surface mining methods and techniques for removing overburden and coal have
been improved continuously since the days of mule-drawn scrapers. These im-
provements have been made possible by the technological advancements in stripp-
ing equipment that have enabled the mining industry to move to the era of
gigantic earthmovers.
Machines used in current strip mining methods include draglines, shovels,
bucket wheel excavators, bulldozers, front-end wheel loaders, pan scrapers and
haulage trucks. Each has its place.
The trend to larger equipment for surface mining seems to have leveled off and
will provide a breathing space in which to evaluate what has been developed
and to improve mined-land reclamation technology. Some of the new, large equip-
ment was not proven in the field before an even larger model was introduced.
The peaking is due in part to the low operating efficiency that showed up when
these giants were put into operation. Several strip mine operators have
already made the switch to smaller equipment. The mining industry's major
effort is being put into imporving the design of medium size equipment, i.e.,
longer, lightweight booms with small bucket capacities so as to increase the
reach of draglines U7).
A long boom is essential in thick overburden, as are wide pits in order to
reduce the quantity of overburden that must be rehandled. Under favorable
conditions, a dragline with a long boom can strip overburden from a single
coal seam, cast the spoil in such a manner that very little grading will be
necessary to meet grading specifications, and spread topsoil over the graded
area. The dragline is a very adaptable prime mover of overburden and can be
used successfully in tandem with other equipment.
87
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Where a stripping shovel is the prime mover of overburden, additional equip-
ment is necessary if topsoil is to be segregated and spread on the graded
areas. Grading is generally done with bulldozers and topsoil is salvaged and
spread with scrapers. A rehandle dragline, bucket-wheel excavator, or small
long-'boomed shovel are sometimes used in tandem with the stripping shovel to
segregate overburden in place of scrapers.
«
The bucket-wheel excavator can be used as a prime mover if the overburden is
unconsolidated, soft material that requires little or no preparation. The
telescoping conveyor allows a much greater dumping radius than other equipment.
It can be operated so that either topsoil or a selected strata of overburden
will be placed atop the graded spoil. Spoil can be placed in such a manner
that it will be relatively free of peaks and ridges and thus minimize grading.
Some mining operations currently use the bucket-wheel excavator in tandem with
other machinery, removing the unconsolidated material above the rock strata
and depositing it a long distance from the active pit. As reclamation require-
ments become more comprehensive and overburden segregation is necessary, the
bucket-wheel excavator is a likely choice, since it is a good reclamation tool
that is able to separate upper soils quite easily. Unconsolidated overburden
thickness must be great enough to economically use bucket-wheels. Otherwise,
the scrapper pan is more versatile.
Not all equipment is adaptable to selective overburden removal and placement.
Scrapers, front-end loaders, and trucks have proven to be very versatile for
removal and deposition of topsoil or a toxic strata that must "be segregated and
buried. They have been used successfully in both stripping and reclamation
cycles where the overburden consisted of unconsolidated to moderately consolid-
ated material. Scrapers should be the equipment used where removing and
stockpiling thin layers of topsoil is necessary and where contamination with
other materials must be controlled.
Support and associated stripping equipment has kept pace with the development
of the prime movers of overburden. Large dozers such as the Aliis-Chalmers
HD-1|1 and the Caterpillar D9G have found widespread use in mining applications
throughout the country. Off-highway haul-trucks are available with capacities
over 200 tons (l8l.U metric tons). In the past, many of these large-capacity
coal haulers were unproven, but as operating experience has been gained and
modifications made, they are now being endorsed by industry. Elevating
scrapers offer cost advantages over truck haulers on short haul distances and
can be more economical than a dragline in a low stripping ratio or limited
production operation (17).. They are very economical in land reclamation where
it is necessary to remove and place topsoil} however, scrapers are not
recommended for hauls exceeding an operating radius of approximately 1 mile
(1.6 kilometers), (18}. The scraper is a popular tool because it can dig its
own load, transport the load at speeds of 20 to 35 mph (32 to 56 km/h), and
spread the load in the dumping area. The development of the rip dozer has
greatly increased the range of the scraper. Shales and soft rock that
previously resisted loading by scrapers are now successfully loosened. Large
dual-engine scrapers are being used to place selected material atop the graded
spoil and form the final surface contour "before revegetation.
-------
Front-end wheel loaders of nearly every available size are being used to load
out coal in the pit and have replaced loading shovels at some operations. The
trend for these machines continues to be their rapidly increasing size. Clark
Equipment Company's "Michigan" 2U-cubic-yard (l8 cubic meters) capacity Model
6?5 is the largest wheel loader built to date. In contour stripping operations,
the wheel loader is being used as the primary overburden removal machine and is
referred to as the load and carry method. The strengthening of these machines
along with new contour mining methods,(block-cut, and mountain-top removal,
for example) will see a greatly expanded use of front-end wheel loaders in the
future.
In selecting equipment, the choice of stripping units is influenced principally
by the system of mining, whether contour or area type. Other factors such as
life of mine, production desired, types of overburden, spoil area, selling
price of the coal, and reclamation requirements must also be considered.
89
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REFERENCES
1. An Analysis of Strip Mining Methods and Equipment Selection. Research
and Development Report No. 6l, Interim Report No. 7. Prepared "by Coal
Research Section, Pennsylvania State University for Office of Coal
Research, U.S. Department of Interior, Washington, D.C., May 1973.
2. Porter, W.E., Multiple Seam Stripping: A Survey and Economic Feasibility
Model, Unpublished M. Eng. Report, The Pennsylvania State University, 1972.
3. Ramani, R.V. and Manula, C.B., Computer Simulation of Bucket Wheel
Excavators, SME Transactions, A.I.M.E., Vol. 2^7, September, 1970.
U. Levene, H.D. , An Unusual Coal Mine/Power Plant Complex, Coal Mining and
Processing, October, 1971.
5. Anonymous, Ayrgem Taps New Coal Reserves, Coal Age, May, 1970.
6. Ford, W.W. , Slope Reduction Methods. Unpublished Report, Division of
Reclamation, Department of Natural Resources, Frankfort, Kentucky, 1968.
7. Ford, W.W. , Slope Reduction Method (Parallel Fill). Unpublished Report,
Division of Reclamation, Department of Natural Resources, Frankfort,
Kentucky, 1970.
8. Design of Surface Mining Systems. Prepared by Mathematica, Inc.,
Princeton, New Jersey for the Commonwealth of Kentucky, April 1973.
9- Blakely, J. Wes, Mason, Richard H. , A City of 20,000 is Possible on
Former Strip Mine Site. Coal Mining and Processing, 10, (9), September
1973. 300 W. Adams Street, Chicago, Illinois.
10. Saperstein, Lee W. , Secor, Edwin S., Improved Reclamation Potential
With the Block Method of Contour Stripping. In Papers Presented Before
Research and Applied Technology Symposium on Mined-Land Reclamation,
Pittsburg, Pennsylvania, Bituminous Coal Research, Inc., March 1973.
11. Maneval, David R. , Coal Mining vs. Environment: A Reconciliation in
Pennsylvania. Appalachia, A. Journal of the Appalachian Regional
Commission, 5, (*0, February-March 1972.
12. Allen, Natie, Jr., Experimental Multiple Seam Mining and Reclamation on
Steep Mountain Slopes. In Papers Presented Before Research and Applied
Technology Symposium on Mined-Land Reclamation, Pittsburg, Pennsylvania,
Bituminous Coal Research, Inc., March 1973.
13. Heine, Walter N. , Guakert, William E. , A New Method of Surface Coal
Mining in Steep Terrain. In Papers Presented Before Research and Applied
Technology Symposium on Mined-Land Reclamation, Pittsburg, Pennsylvania,
Bituminous Coal Research, Inc., March 1973.
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lU. Coal Surface Mining and Reclamation; An Environmental and Economic
Assessment of Alternatives. Prepared for the Senate Committee on Interior
and Insular Affairs by Council on Environmental Quality, Executive Office
of the President, Washington, D.C., March 1973.
15. Steep Slope Mining—A New Concept. Green Lands. West Virginia Surface
Mining and Reclamation Association, Summer Quarterly, 1973.
16. Lusk, Benjamin E., Mulhern, John J., New Surface Mining Technology to
Minimize Environmental Disturbance. Paper presented at the 1973 Mining
Convention/Environmental Show of the American Mining Congress, Denver,
Colorado, Sept. 9-12, 1973.
17. Kennedy, Bruce A., Talbot, Richard, and Wade, E.J., What's New in Mining
in 1972. World Mining 26 (9), June 1973. Miller Freeman Publications,
Inc., San Francisco, California.
18. Moolick, R.T., and O'Neill, John E., Stripping Methods Including Advanced
Stripping. Seeley W. Mudd Series, Surface Mining, Section ^.2, AIME,
New York, 1968.
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SECTION V
BLASTING
INTRODUCTION
The goal of blasting is to get maximum fragmentation of the consolidated
material in the overburden with optimum drilling and blasting cost. The amount
of fragmentation required is determined by the stripping unit to be used in
overburden removal. Many coal seams must also be broken by blasting; this is
conducted before coal removal. There are environmental factors as well as due
regard for public safety, health, and welfare that must be considered in
choosing the blasting plan.
The blasting plan should be made during preplanning and is based on data from
the overburden cores. Analysis of the data will help in determining the kind
of drilling equipment and bit types that will be needed for overburden
preparation.
TYPES OF DRILLING
Vertical Drilling. Rotary dry type units continue to lead in drilling vertical
holes, although some companies are using improved vertical augers. Hole
diameters range from 5*§ to 15^ inches (139. ^ to 393. T millimeters).
Horizontal Augering. The horizontal sidewall auger is used where the cover is
thin or where hard materials lie close to the coal seam(l). This auger has
several advantages:
1. The cost per foot (meter) of drilling is less.
2. No special preparation such as a drill bench is required.
3. It is easier to get electrical power to the drill.
k. It is easier to get blasting materials to the drill holes.
Horizontal Rotary Drilling. Horizontal drilling is used by some operators but
.is not as popular as vertical drilling. Disadvantages include:
1. Fragmentation of the overburden is poor when heights are in excess
of 30 feet (9.12 meters).
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2. Underlying coal seam is "badly shattered.
3. Unstable highwalls make drilling very hazardous.
In many operations, drilling must proceed before the previous shot is loaded.
This is one of the main reasons that vertical drills predominate(2).
BLASTING CONTROL
A variety of complaints have always been received by industry pertaining to
blasting. Since World War II, the population explosion and urban sprawl have
acted to bring industry and the public into closer physical contact. In many
cases, structures were built on property adjacent to surface mining operations.
As a result, the number of complaints increased drastically and presently
constitute a major problem.
Some complaints registered are legitimate claims of damage from blasting
vibrations. The advances in blasting technology and a more knowledgeable blast-
ing profession have minimized real structural damages. However, vibration
levels that are completely safe for structures may be annoying and unpleasant
for people. Though no actual damage is done, air blast pressures may cause
windows to rattle and the loud noise can be intolerable. Repeated vibrations,
such as those from a nearby quarry, may eventually cause damage.
Control of Vibration damage to natural scenic formations is a very important
environmental consideration in surface mining in the West. These wind-eroded
formations are very fragile, and damage as far.as on fourth of a mile :(.k02
kilometers) from the operation have been noted'3).
Where conventional detonating cord is used to link blastholes, most airborne
noise results from these connecting trunk lines. A new, low-energy detonating
cord has been developed that can be substituted for the conventional cord. A
150-foot (^5.6 meters) length of this cord makes about as much noise as one
electric blasting cap or 2 inches (50.8 millimeters) of the conventional cord
cord (l).
If detonating cord is used on the surface, noise can be reduced by covering the
trunk lines with up to 10 inches (25^ millimeters) of dirt. When detonating
cord is used only in the holes to fire the primers, a shovelfull of dirt at
each hole will effectively cover the exposed cord and cap.
Millisecond delays can be used to decrease the vibration level from blasting,
because it is the maximum charge weight per delay interval rather than the
total charge that determines the resulting amplitude (*0. Also many mines limit
the number of holes per shot, using millisecond delays in series to minimize
concussion and noise, especially near population centers, natural scenic forma-
tions, wells, water impoundments, and stream channels.
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Weather conditions can cause an increase in airborne noise. When temperature
inversions prevail, blasting should be avoided. This condition exists
frequently in early dawn and after sundown. Foggy, hazy, or smoky days are
unfavorable for blasting. When the wind direction is toward residential areas,
blasting should be postponed(5,6).
When blasting is performed in congested areas or close to a structure, stream,
highway, or other installation, the blast should be covered with a mat to
prevent fragments from being thrown by the blast. The possibility of dust
problems from blasting is very remote.
The possibility does exist, however, and precautions must be taken to control
dust pollution if the operation is close to high-use areas. During periods of
dry weather, dust from explosions have been carried by air currents for many
miles, and in certain isolated instances, it has been a public nuisance.
Several States, including West Virginia, Tennessee, Ohio, Montana, and Kentucky
have established guidelines for preventing or holding vibration damages to a
minimum. Most of the State laws concerning blasting pertain only to safety,
storage, handling, and transportation of explosives.
When a blast is detonated, the bulk of energy is consumed by fragmentation and
some permanent displacement of the rock close to the location of the drilled
holes containing the explosive. This activity normally occurs within a few
tens of feet (meters) of the blast hole. Leftover energy is dissipated in the
form of waves travelling outward from the blast, either through the ground or
through the atmosphere. The ground waves produce oscillations in the soil or
rock through which they pass, with the intensity of these oscillations de-
creasing as distance from the blast increases(7).
One measurable quantity of interest that is caused by seismic waves or
oscillations is particle velocity. This quantity defines "how fast a particle
(or structure) is moved by passing seismic waves, measured in inches (milli-
meters) per second"(T). The results of a 10-year study program in blasting
seismology by the U.S. Bureau of Mines(M concluded that particle velocity is
more directly related to structural damage than particle displacement or
particle acceleration. It is not how much but how fast the ground under a
structure is moved by the passing seismic waves that determine the likelihood
of damage. Particle velocity, therefore, becomes the vibration quantity of
greatest concern to those engaged in blasting activities(7). They also
concluded that a safe blasting limit of 2.0 inches per second (50.8 millimeters)
peak particle velocity as measured from any of three mutually perpendicular
directions in the ground adjacent to a structure should not be exceeded if the
probability of damage to the structure is to be small (less than 5$)(M.
Kentucky is the only coal-producing State that now has a law based on seismo-
graphic measurements. They limit vibrations adjacent to any structure to levels
producing a particle velocity of 2.0 inches per second (50.8 millimeters) or
less.
-------
Where instrumentation is not used or is not available, the U,S. Bureau of
Mines (U) found that a scaled distance of 50 feet per square root of pounds
(22.62 meters per square root of kilograms) can be used as a control limit
with a reasonable margin of safety, and the probability is small of finding
a site that produces a vibration level that exceeds the safe blasting limit
of 2.0 inches per second. For cases where a scaled distance of 50 feet per
square root of pounds (22.62 meters per square root of kilgrams) appears to
be too restrictive, a controlled experiment with instrumentation should be
conducted to determine what scaled distance can be used to insure that vibra-
tion levels do not exceed the particle velocity of 2.0 inches per second
(50.8 millimeters).
2
West Virginia uses the scaled distance formula, W=(D/50) , for control of vibra-
tion damages. W equals the weight in pounds (kilograms) of explosives detonated
at any one instant and D equals the distance in feet (meters) from the nearest
Structure — provided that explosive charges are considered to be detonated at
one time if their detonation occurs within 8 milliseconds or less of each other
(see Table 7) for maximum explosive charges. A blasting plan (Figure 58 ) for
each method for a typical blast must be submitted with the permit application'°'
(Figure 59 ).
Greene^) reports that citizen complaints concerning blasting on surface mining
operations have been drastically reduced since the 1971 West Virginia law be-
came effective. He also stated that to the best of his knowledge there have
been no claims for damage made during this period. Greene credits this success
to the conscientious efforts by the operators in using the scaled distance
formula and guidelines for blasting issued by the State of West Virginia
Department of Natural Resources.
Ammonium nitrate-fuel oil (AW/FO) blasting agents and slurries, used as breaking
mediums for overburden, have greatly improved the efficiency of surface mine
blasting operations and have reduced the cost of explosives considerably. It
is an excellent heterogeneous fertilizer, since it contains readily available
ammonia nitrogen and nitrate nitrogen and ,does not leave unfavorable residues
in the soil. As a constituent of various types of explosives, it functions as
an oxidizer and an explosive modifier^10). AN/FO mixes lead all other types
of explosives in bank preparation. Several types are available and can be
obtained in prilled, granular, crystalline, or grained forms.
A new line of metalized blasting agents is now available commercially. These
products are reported to be three times more powerful by weight and five times
more powerful by volume than AN/FO combinations. Based on ammonium nitrate in
combination with aluminum chips, the blasting agents vary in aluminum content
between a low of 5$ and a high of 30%. They are soft, silvery gels and
maintain the softness even at 0°F (-l8°C)(l).
A trend is developing for casting overburden with explosives. The goal is to
cast as much overburden as possible into the parallel cut with blasting
techniques. With proper loading, spacing, and detonation delays, a good portion
of overburden can be moved, thus reducing backfilling costs(H). This method
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Table 7.
MAXIMUM EXPLOSIVE CHARGES k) USING SCALED DISTANCE FORMULA
W = (D/50)2
Distance to Maximum explosive
nearest residence charge (to "be
building or other detonated)
structure (ft) (lb)
100
150
200
250
300
350
Uoo
1*50
500
550
600
650
700
750
800
850
900
950
1,000
1,050
1,100
1,150
1,200
1,250
1,300
1,350
1,UOO
1,U50
1,500
1,550
1,600
1,700
1,750
1,800
1,850
1,900
1,950
2,000
Metric Unit
foot = 0.
pound = 0
U
9
16
25
36
1*9
6k
81
100
121
lUU
169
196
225
256
289
32k
361
Uoo
UUl
U8U
529
576
625
676
729
78U
8Ul
900
96l
1.02U
1,156
1,225
1,296
1,369
1,UUU
1,521
1,600
Distance to Maximum explosive
nearest residence charge (to be
building or other detonated)
structure (ft) (lb)
2,100 1,76U
2,200 1,936
f —
2,300 2,116
2, UOO 2,30U
2,500 2,500
2,600 2,70U
2,700 2,916
2,800 3,136
2,900 3,36U
3,000 3,600
3,100 3,8UU
3,200 U,096
3,300 U,356
3, UOO U,62U
3,500 U,900
3,600 5,l8U
3,700 5,U76
3,800 5,776
3,900 6,08U
U.OOO 6, UOO
U,100 6,72U
U,200 7,056
U,300 7,396
U.UOO 7,7UU
U,500 8,100
U,600 8,U6U
U,700 8,836
U,800 9,216
U,900 9,60U
5 ,000 10 ,000
(l)where blast sizes would exceed the
limits of the scaled distance formula,
blasts shall be denoted by the use of
delay detonators (either electric or
nonelectric) to provide detonation
times separated by 9 milliseconds or
more for each section of the blast
conrolvine with the scaled distance of
the formula. Explosive charges shall
Conversion: be considered to be detonated at one
30U meters , time if their detonation occurs within
.U53 kilograms . , 8 milliseconds or less of each other.
96
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ELEVATION VIEW
O is1 O
00
O O
0 0
O 0
0 0
O O
0 O
0 O
0 0
0 O
1
c
I/
u
c
)
»
1
1
4
DRILL BENCH
9" DIAMETER
HOLES
•« 18-25' f
COAL SEAM
TYPH
CAL L<
M
DAD
Stemming
340 Pounds
PLAN VIEW
W= (D/50)2
Distance to nearest dwelling = approximately 5000 feet.
W= (5000/50)2 = 10,000 pounds/delay period permitted. Propose to use
American Cyanamid Millisecond Electric Blasting Caps. In this instance, will shoot
twenty (20) holes/delay period, a total of 6800 pounds of explosives.
(See Abov? Delay Pattern)
Metric Unit Conversion:
inch = 25.1+ millimeters; foot= 0.30U meters; pound = 0.1+53 kilograms
Figure 58. Proposed Blasting Plan
(Example)
97
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•-'
•fefe?
Figure 59. Drill holes laid out according to blasting plan
and ready for loading.
-------
also minimizes the need for recasting, Some mines report that 30% to 50$ of
their overburden is moved with ejcplosives(l). this method works very well in
deep narrow pits by casting overburden into the pit away from the highwall and
up on the spoil pile on the low wall side.
SUMMARY
Since the general public is directly involved in blasting vibration problems,
it has become the number one concern of government agencies and the mining
industry. Because of the large number of complaints and lawsuits for damages
by property owners, many States have adopted blasting codes.
Airborne vibrations are the basis of most complaints. Although no actual
damage may be done, the loud noise is annoying.
H.B. Charmbury report(1:0 that in an effort to prevent damages from air blasts,
vibrations, and concussions, there is a trend by industry to monitor blasting
that is performed near villages and towns. Adequate stemming, use of milli-
second delays, awareness of prevailing wind direction, blasting only during
daylight hours, and careful consideration of charge size usually keep this type
of noise pollution and surface damage at a minimum.
99
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REFERENCES
1. Surface Mining. Coal Age; 1972 Mining Guidebook and Buying Directory.
McGraw-Hill, Hightstown, New Jersey, July 1972.
2. Williamson, T.N., Surface Mining. Seely ¥. Mudd Series; Rotary Drilling,
Section 6.3. American Institute of Mining, Metallurgical and Petroleum
Engineers, Inc., New York, 1968.
3. Grim, Elmore C., Trip Report on Evaluation of Montana's Reclamation
Situation. U.S. Environmental Protection Agency, National Environmental
Research Center, Cincinnati, Ohio, November 1972.
U. Nicholls, Harry R. , Johnson, Charles F. , and Duvall, Wilbur J. , Blasting
Vibrations and Their Effects on Structures. U.S. Department of Interior,
Bureau of Mines Bulletin 656, 1971.
5. Perkins, Beauregard, Jr., and Jackson, Wills F. , Handbook for Prediction
of Air Blast Focusing. Ballistic Research Laboratories Report No. 12^0,
U.S. Army, Aberdeen, Maryland. February
6. Perkins, Beauregard, Jr., Lorrain, Paul H. , and Townsend, William H. ,
Forecasting the Focus of Air Blast Due to Meteorological Conditions in
the Lower Atmosphere. Ballistic Research Laboratories Report No. 1118,
U.S. Army, Aberdeen, Maryland, October I960.
7. Berger, Philip R. , Blasting Controls and Regulations. Mining Congress
Journal. American Mining Congress, 59 (ll)» November 1973.
8. West Virginia Code, Chapter 20: Surface Mining and Reclamation; Section
6-lla, Blasting Restriction; Formula; Filing Preplan; Penalties;
Notice, 1971.
9. Private Communication; Greene, Benjamin, C., Chief, Division of Reclama-
tion, Department of Natural Resources, Charleston, West Virginia, July
1973.
10. The New Look of Blasting. Gulf Oil Chemical Company, Blasting Materials,
3^35 Broadway, Kansas City, Missouri, 1967.
11. Charmbury, H.B. Surface Mining of Coal — 1972. Mining Congress Journal.
American Mining Congress, 59 (2), February 1973.
100
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SECTION VI
SEDIMENT AMD EROSION CONTROL
INTRODUCTION
Sediment is one of America's greatest pollutants. More than a "billion tons of
sediment reach the major streams of the United States annually(l). Damages are
reflected in the reduced carrying capacity of streams, clogged reservoirs,
destroyed habitat for fish and other aquatic life, filled navigation channels,
increased flood crests, degraded facilities for water-based recreation, in-
creased industrial and domestic water treatment costs, premature aging of lakes
by enrichment of the water with silt-carried fertilizer that promotes algae
growth, destroy crops, and reduce productivity of flood plain soils.
Erosion and sedimentation are natural processes that are usually gentle actions
releasing controlled amounts of silt from watersheds to receiving streams.
Surface mining activities accelerate these natural processes and short dura-
tion, high intensity storms can become a violent force moving thousands of
tons of soil in a brief period of time. Cover is a very important factor. With
the removal of ground cover, water moves across the denuded area on its own
terms picking up soil particles as it flows and leaving gullies behind. The
susceptibility of strip-mined land to erosion depends on:
1. Physical characteristics of the overburden
2. Degree of slope
3. Length of slope
U. Climate
5. Amount and rate of rainfall
6. Type and percent of vegetative ground cover.
?y development of erosion and sedimentation control plans before disturbance of
the area, many of the detrimental effects of strip mining can be prevented.
CONTROL MEASURES
The key to minimizing erosion and sediment problems is in the control of water
flowing into, within, and from the surface mining area. Control measures must
'be designed according to sound engineering principles that will fit the
101
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topography, soils, rainfall, climate, and land use of areas they are to protect.
These controls include a wide variety of measures, and facilities that are
either vegetative or mechanical in nature. Iheir objective is to prevent
accelerated erosion and sedimentation. To be effective, controls must be
properly installed and maintained. To insure that the detailed erosion and
sediment control procedures are implemented by the surface mine operator,
these plans are integrated with the mining and reclamation sequences.
Sediment yield from a mined watershed is the result of erosion from the dis-
turbed area and the movement of this eroded material from the watershed. There-
fore, sediment yield varies, not only with the extent of disturbance within the
watershed, but also with the proximity of the disturbed area to the natural
stream channel. Thus, surface mines and access roads, where the outer fill
slopes approach the stream channel, will yield greater quantities of sediment
than those separated from the channel by a filter zone(2). Experience has
shown that a protective, vegetated strip of undisturbed soil between the toe
of the fill and natural drainways usually prevents muddy water from reaching
streams. This filter zone must be wide enough to absorb all the muddy water
that runs off outslopes. Sediment is collected on the undisturbed litter and
soil, and only clear water enters the stream. The required filter-zone width
varies with the steepness and length of the outslope betwen the toe and the
drainage channel. A minimum distance of 100 feet (30.5 meters) between the
strip mine operation and any stream is required by Kentucky law\3). Often,
steep slopes will require that the filter zone be more than 100 feet (30.5
meters) wide.
The mining industry is now faced with another new parameter, i.e., the salvage
and stockpiling of topsoil for later use as topdressing. Stockpile areas must
be located far enough from water courses so that they will not provide a source
of sediment during storm runoff. Critical slopes on stockpiles must be avoided,
especially if the material is easily eroded. Temporary soil stabilization
measures should be established immediately after the stockpile operation is
completed. If the stockpiling is a continuing operation, then temporary
stabilization methods are implemented in stages as stockpiling progresses.
Stabilization can be accomplished with a vegetative cover or by chemical
means. Chemical soil stabilizers penetrate the surface and bind soil particles
into a coherent mass that reduces erosion by wind and rain. A quick growing
cover of herbaceous species will also provide temporary protection against
erosion (see Section IX, Revegetation, for species and seeding recommendations).
One of the primary rules for good erosion and sediment control is that all
earthmoving activities be planned in such a manner that the minimum amount of
disturbed area will be exposed for the minimum amount of time. This objective
can be accomplished by developing the area in stages with progressive backfill-
ing and reclamation. Consideration must be given to critical areas such as
steep slopes and high soil credibility. Climatic factors as they relate to
vegetative stabilization must also be considered; for example, topsoil should
not be placed while in a frozen or muddy condition or when the subgrade is
excessively wet.
102
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Since sediment causes more off-site damage than any other aspect of strip
mining, it is essential that steps be taken for the control of sedimentation.
Sediment retention basins can be effectively utilized for collection and
holding of eroded material before it reaches the main streams, thus preventing
damage to areas downstream. Ey detaining storm water, sediment basins also
reduce peak flows. Since most of the settleable solids drop out of suspension
quickly in quiet water, it is unnecessary that the basins remain filled with
water.
Sediment basins should be located on all drainways carrying concentrated flows
from the disturbed areas. They should be located as close to the sediment
source as possible and before the drainageways reach the main stream. Maps
that delineate the various phases of mining and reclamation should also show
the location of all sediment control retention structures. The drainage plan
must indicate the sequence of construction, with all necessary structures being
built in a specific area before the initiation of clearing and grubbing
operations.
Sediment control structures are created by the construction of a barrier or a
dam across a drainway, or by excavation of a basin, or by a combination of these
methods to trap and store eroded material. These catch basins are nearly
always temporary structures. However, they can be designed as permanent
structures if there is a need for them, if they will not endanger life and
property in case of failure, and if a responsible party will continue mainten-
ance. Where maximum storage can be obtained with a basin of planned size,
it should be constructed adjacent to the drainageway and be of the diversion
type. After the mining is completed and the area stabilized, diversions can be
closed with the collected sediment isolated from further flows.
Sediment control basins are classified as either primary or secondary, accord-
ing to their design, location, and intended use.
Primary basins consist of three basic types:
1. Excavation or dugout. This type of basin is a water impoundment made
by excavating a pit or dugout. An earth embankment is sometimes
used with the dugout to increase its capacity.
2. Earth embankment. This basin is a water-retention-type structure
constructed across a waterway or other suitable location to form a
sediment catch basin. Where topography or the site restricts storage
requirements, structures may be built in series so that the cumulative
total of the sediment storage capacity will equal the storage
requirements for each acre (0.^0 hectares) of disturbed area in that
watershed (Figure 60 ).
3. Leaky dam. This basin is a rock-french-drain-type structure that is
used to momentarily stop runoff water so that it can deposit its
sediment load before leaking through the dam. It has been used very
successfully on small watersheds of less than 150 acres (60 hectares)
and on larger areas in combination with earth embankments to catch
initial sediment loads.
103
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Figure 60. Earth embankment sediment control basin.
Secondary basins consist of facilities that are not adequate for sediment con-
trol vhen used alone. They are used to catch initial sediment loads near the
disturbed area, and thus they lengthen the time between cleanouts for downstream
primary structures.
Types of secondary structures are as follows:
1. Gabions. This structure is made up of large, multi-celled, rectangu-
lar, wire-mesh baskets that are rock-filled. They are used as
building blocks in the construction of sediment control structures.
Gabions are used mainly in building small check dams across drainways;
however, they are very versatile, and under favorable conditions,
they can be used as primary structures. During construction, founda-
tions must be properly prepared and the gabions securely keyed into
the foundation and abutment surfaces. Rock used in filling the
baskets must be durable and adequately sized (Figure 6l).
-------
Figure 6l. Gabions used as a sediment control structure.
2. Log and pole. This check dam structure is strictly a stop-gap
measure for collecting sediment in small drainways. They have not
proven to "be very successful in field use and should only be used in
an emergency situation. They must be replaced at the first
opportunity, after the emergency no longer exists.
3. Rock dam. This type of check dam is a barrier built across a drain-
ageway to retard storm runoff and form a small sediment collection
basin to assist in sediment control. Such dams are not substitutes
for primary structures. Rock check dams are usually used where small
localized sedimentation problems exist and the drainage area is less
than 50 acres (20 hectares).
105
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Sediment Control Basins, Primary /type — Technical information and design
criteria for primary sediment control basins are as follows:
1. Excavation or dugout. The West Virginia Department of Natural
Resources, in cooperation with the U.S. Soil Conservation Service,
has prepared standards for the design and construction of excavated
sediment ponds in one section of the Drainage Handbook for Surface
Mining (*0. The text is presented in Appendix B as an example and is
for general interest only. It should be noted that under "capacity
requirements," the excavated sediment pond must have a minimum
capacity to store .125 acre-feet (.05 hectare-meters) per acre
(hectares) of disturbed area in the watershed. Stanford Research
Institute, in its 1972 report A Study of Surface Coal Mining in West
Virginia(5), stated the following: However, this storage capacity is
only for a type II storm of 2k hours duration with a 10 year frequency.
It would be more prudent to provide a greater safety factor by re-
quiring storage for a more severe storm. Sediment storage requirements
should probably be increased to 0.28 acre-feet (.112 hectare-meters)
per acre (hectare) as now employed in Kentucky ^Editors note:
Kentucky now requires 0.20 acre-feet (.08 hectare-meters) per acre
(hectare) (M J This would provide a measure of protection against a
more severe 50-year magnitude storm. The prospective 0.125 acre-feet
(.05 hectare-meters) dams require maintenance and clean-out when they
become 60 percent filled. This amount of sediment could be trapped
in less than a year. CEditors note: Actual operational experience
during the past year has shown that some of these basins fill up after
only one moderate storm, depending mainly on the soil type(o)J
Filling to depths greater than 60 percent greatly reduces the capacity
of the basin to retain runoff long enough for sediment to be deposited
before it moves downstream. The sediment removal operation must
consider the stable disposition of removed materials in a manner that
will not permit its reentry into the drainage system to again become
a pollutant.
Recent studies by the U.S. Forest Service, in which they have
measured silt buildup in sediment ponds, revealed that 0.2 acre-feet
(.08 hectare-meters) of storage per acre (hectare) of disturbed land
was a reasonable figure(T).
2. Earth embankment. These sediment retention basins are constructed to
detain water long enough to allow soil particles that the water is
carrying to settle out by natural gravitation. It must be recognized
that basins of the size that will normally be constructed will not
retain the runoff long enough to settle out colloidal material.
Location of the embankment is critical to successful installation and
operation of the sediment basin. Topography of the watershed will
play an important part in selecting the dam site. Construction
material must be readily available and the site should provide maxi-
mum storage of silt behind the structure. Failure of the structure
should not result in the loss of life or damage to property.
106
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All earth embankment type sediment retention "basins must be designed
and constructed according to sound engineering principles. Practical-
ly all failures of this type of structure can be traced to faulty
engineering, (i.e., (a) inadequate emergency spillway, or (b) in-
adequate capacity for the area drained, which can result in filling
of the sediment storage area after only one storm, insufficient
retention time to settle out suspended solids, or a larger-than-
anticipated volume of water that sweeps the dam away. Sediment con-
trol basins must be installed before disturbance within the immediate
watershed. If the proposed mining area is located in several water-
sheds, basin construction is scheduled in advance of mining so that
the affected watershed will be protected before disturbance.
There is no substitute for good planning, design, construction, and
maintenance of sediment control basins if they are to provide
effective sediment control of runoff water arid prevent off-site
damages. However, it must be recognized that there are locations
where the physical characteristics of the terrain are such that
effective sediment control basins cannot be constructed. If these
conditions exist, then surface mining should be prohibited.
Technical assistance regarding sedimentation problems can generally
be obtained from the local county soil and water conservation
district and the Soil Conservation Service, U.S. Department of Agri-
culture. In many cases, the District will schedule the assistance
of qualified personnel to conduct surveys in the proposed mining area
with the operator to gather data for development of plans to control
erosion and sediment, including location and design of needed sediment
control structures. A publication entitled Engineering Standard for
Debris Basin for Control of Sediment From Surface Mining Operations
in Eastern Kentucky, has been prepared by the U.S. Department of
Agriculture Soil Conservation Service and is included as Appendix C.
The specifications are presented as an- example and are for general
interest only.
As stated before, sediment control basins work on the theory that by
reducing the velocity of the runoff water, natural gravitational
settling will clear the water before discharge into receiving streams.
Experience in the field with this type of structure strongly indicates
that gravitational settling alone would not be sufficient to clarify
muddy water. Some clay soils are of colloidal nature and may stay in
suspension for weeks, causing turbid water conditions. Material such
as lime, alum, and organic polyelectrolyte added to the muddy water
will cause flocculation of the suspended particles into an agglomera-
tion of particles; then gravitational settling out will occur an&
clarification of the treated water takes place. McCarthyvS), in a
test project near Centralia, Washington, recognized that natural
gravitation alone would not lower the suspended solids to acceptable
levels. The high clay content of the soil caused the runoff water to
be very turbid. These colloidal particles were found to carry a
negative electrical charge, thus repelling each other and resisting
flocculation and settling.
107
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Tests indicated, that the addition of an organic polyelectrolyte with
a positive electrical charge would effectively cause flocculation of
the suspended particles, and then gravitational settling would occur,
Two settling ponds were constructed in series, and the organic
polyelectrolyte was added at the discharge point of the first pond.
Flocculation, settling, and clarification takes place in the second
pond. The State of Washington waste discharge permit requires that
the discharge not be more than 5 Jackson's Turbidity Unit above normal
background. Turbidity range of the receiving stream during the rainy
season was found to be between 20 and 55 JTU's. Three-times-daily
water testing showed that the turbidity of the water at the pond
discharge weir would remain within the range of 85 to 120 JTU's with-
out chemical treatment. After treatment with an organic polyelectro-
lyte, the decantate from the second pond was clear and had a range
or U to 15 JTU's.
3. Leaky dam (rock-french drain). Generally, a formal design is not
required; however, criteria for the use and construction of this
type of dam have been developed (Figure 62) (^) and are as follows:
a. The height of the rock dams shall not exceed 20 feet (6 meters)
measured from the flow line of the channel to the top of the dam.
b. All materials used in rock dams shall be end-dumped and dozer-
placed in lifts not to exceed 5 feet (1.5 meters).
c. The downstream portion of rock dams from the downstream toe to
the upstream shoulder shall be constructed of boulders not
smaller than 1/2 cubic yard (.38 cubic meters) nor larger than
2 cubic yards (1.5 cubic meters).
d. The upstream portion of the rock dam from the upstream toe to the
upstream shoulder shall not be constructed of shot rock not
larger than 1/U cubic yard (.19 cubic meters).
e. The side slopes of the dam shall be less than l?g:l.
f. The top of the dam shall be level in both grade and template.
g. The width of the top of the dam shall be a minimum of 10 feet
(3.0l* meters).
h. No emergency spillway or principal spillway will be erected in
this type of dam.
PIT DRAINAGE
Pit drainage is the control of water that is being removed from the pit area
during actual mining operations so that it will not provide sediment for
receiving streams.
108
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Figure 62. Typical section of rock-freneh drain sediment control basin
(leaky-dam type).
Surface runoff, rainfall, and seepage water often collects in the working pit
areas and must be removed. If this accumulated water is in an area where equip-
ment is moving back and forth, large quantities of spoil are churned up and put
into suspension. A much too common practice is to bulldoze a cut through the
bench crest and discharge the accumulated water onto the outslope. Observation
indicates that serious erosion occurs on spoil outslopes when pit water is
caused or permitted to flow onto or over these areas(2). The deleterious effect
on the environment can be very great, and in some cases, entire streams have
been destroyed by this eroded spoil and sediment from pit areas. If the water
comes in contact with toxic materials, another problem is added that can be as
bad or worse than the sedimentation problem (See Section X, Acid Mine Drainage).
Pit water should be released slowly through the use of siphons or pumps with
outlets below the toe of the outslope. Pumping or siphoning can be regulated to
control the flow and to prevent overloading of the natural drainage ways or
holding ponds. Holding ponds may also act as settling basins for sediment and/
or be a part of the chemical treatment facilities for toxic water.
BENCH DRAINAGE
Bench drainage is associated only with contour mining on steep slopes and
involves removing water from the bench area. This is accomplished by making
waterways draining to an outlet in the direction of the bench slope. In no
instance should water be discharged over the bench crest without the use of
structural means to protect against erosion. Lowering of water from the bench
to the receiving stream should be done by using the natural drainways available.
When natural drainways are not available, then grassed waterways or rocklined
chutes, flumes, ditches, or pipes are used, (Figures 63, 6k, and 65). The
109
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Figure 63. Eroded waterway that was not lined.
Figure 6k. Grassed waterway.
110
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•
Figure 65. Waterway lined with half-round Mtuminized fiber pipe.
method of controlling erosion and sedimentation from the bench area and outer
slopes will vary, depending on local conditions. Sediment originating on the
bench should be confined there and not be released in the discharge water. This
objective can be accomplished by the proper use of check dams, shallow ponds,
or swales on the solid bench. Ponds should be constructed so as to be dry
between runoff periods. On virtually all sites, it will be necessary to con-
struct a diversion ditch above the highwall to divert water away from surface
Mining areas (Figure 66 ). This device should be constructed in such a manner
that it can remain as a permanent part of the water disposal system. Proper
outlets to such diversions are an essential part of the plan, and in most
instances will require a sediment pond or debris basin.
Ill
-------
..
>
-
-
""
-• ••• -
V ,
Figure 66. Diversion ditch at top of highwall.
REVEGETATION
With all mechanical measures, it is still imperative that the spoil "be re-
vegetated as rapidly as possible. It is strongly recommended that immediate
cover be obtained, regardless of long-range revegetation plans. Chemical
amelioration of the spoil in the form of lime and nutrient fertilizers is
generally necessary if revegetation practices are to be successful. Seed-bed
preparation, mulches, species selection, and instructions for planting are
covered in Section IX, Revegetation (see Figure 67).
112
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Figure 67. Reduced highwall, mulched to minimize erosion.
(Becker and Mills' point out that for the purposes of sediment and erosion
control, roughness and scarification can be utilized to reduce the production
of sediment and to aid in the establishment of other erosion control practices,
particularly revegetation efforts. They describe roughness as the uneven or
bumpy condition of the soil surface; this condition is typified by surfaces that
have not been smoothgraded. Scarification is defined as the process of loosen-
ing or stirring the soil to shallow depths without turning it over. If grading
is up and down the slope, runoff and erosion are encouraged by the grouser bar
marks left by crawler tractors. If, however, the grading is accomplished on
"the contour, or across the grade, the grouser bar marks will tend to retain
113
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moisture. On a seedbed, the marks trap and retain seed and moisture. This seed
is often covered by soil being carried downslope by runoff and the bar marks
may be the only areas in which seed remains after a rather severe storm. If the
seed thus trapped is a turf-forming grass, it may be sufficient to establish
an acceptable vegetative cover without requiring a reseeding program.
Another example is the slope that is to receive a mulch (woodchips) to protect
it from excessive erosion between seeding seasons. If the slope has been
scarified, the woodchips will adhere to the soil surface with greater tenacity
than they will to a smooth-graded surface.
Infiltration of rainfall is enhanced when a surface is left in a rough condi-
tion. This factor is also important when erosion, sediment, and storm runoff
controls are planned and implemented together in a total conservation program.
SUMMARY
Erosion and sedimentation are considered among the most important adverse
effects of surface mining. Major efforts are now being directed toward control
of these water pollution problems. Mechanical means may be necessary for
initial control during mining and while a vegetative cover is being established
for long-term control.
3y utilizing preventive measures such as good water control and improved mining
and reclamation techniques, erosion and sedimentation from surface mines can be
held to a minimum. This goal can only be accomplished by premining planning
on the part of the stripmine operator.
Each day that a sediment source remains uncontrolled is another day that it
exists as a source of water pollution.
-------
1. Randolph, Jennings, Sediment: Number One Water Pollutant, In Proceedings
of the National Conference on Sediment Control, U.S. Department of Housing
and Urban Development, Washington, D.C., May 1970.
2. Davis, Grant, Strip Mine Reclamation in Appalachia, (Review Draft). U.S.
Department of Agriculture, Forest Service, Northeastern Forest Experiment
Station, July 1971.
3. A Manual of Kentucky Reclamation by Kentucky Department for Natural
Resources and Environmental Protection, Frankfort, Kentucky, May 1973.
k. Drainage Handbook for Surface Mining. Department of Natural Resources,
Division of Reclamation, Charleston, West Virginia, January 1, 1972.
5. Schmidt, R.A., Stoneman, W.C., A Study of Surface Coal Mining in West
Virginia. Stanford Research Institute, Menlo Park, California, February
1972.
6. Private communication. Greene, Benjamin C., Chief, Division of Reclama-
tion, Department of Natural Resources, Charleston, West Virginia, July
1973.
7. Curtis, W.R., Sediment Yield From Strip Mined Watersheds. U.S. Forest
Service, Berea, Kentucky, (in press)
8. McCarthy, Richard E., Surface Mine Siltation Control. Mining Congress
Journal, 59 (6) June 1973.
9- Becker, Burton C., Mills, Thomas R., Guidelines for Erosion and Sediment
Control Planning and Implementation. Hittman Associates, Inc., Office of
Research and Monitoring, U.S. Environmental Protection Agency, Washington,
D.C. EPA-R2-72-015, August 1972.
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SECTION VII
COAL-HAUL EOADS
Coal-haul and mine access roads are defined as any road constructed, improved
or used by the operator (except public roads) that ends at the pit or bench.
These roads constitute approximately 10% of the total area directly disturbed
by the surface mining operation^1). In some cases, the land disturbed by haul
roads exceeds the area included in the mining operation.
Studies (2 and 3)of the U.S. Forest Service in eastern Kentucky show that typical
contour mining roads exhibit poor alignment, excessive grades, insufficient
strength and durability, and poor drainage. Mine roads in other Appalachian
States, particularly where contour mining is practiced, appear much the same as
those in Kentucky. Access roads(M were also found to be a large source of
sediment. It is possible that of the sediment that finds its way into the
streams as much (or even more) originates from the haul roads as from the
mining operation.
Most roads are built as cheaply as possible, and good road-building design and
practice are ignored. Maintenance schedules are generally inadequate, and upon
completion of mining, haul roads are usually abandoned, with little or no
attempt made to bed them down(5). Such roads deteriorate very rapidly
(Figure 68).
Area mining, which is practiced in flat to gently rolling terrain, presents
fewer haul road related environmental problems. These roads through necessity
are generally well engineered because of the heavy equipment using them, such
as 2^0 ton (217 metric ton) haul trucks. They must have wide beds, good
alignment, and adequate drainage to permit coal haulers to run at top speed
during all seasons of the year. Excessive dust can be a public nuisance and
a driving hazard, and it is hard on equipment. Calcium chloride and sodium
chloride have proven to be effective materials for controlling dust. Two
applications during the summer when the ground surface is moist at the rate of
1/2 pound per square yard (.26 kilograms per square meter)(B) have been
suggested. The most common procedure is to keep the roads wet by using water
trucks.
Sediment that reaches the streams can be traced to one or more of the following
five basic phases of haul-road life:
116
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Figure 68. Abandoned coal haul road, no attempt made to bed it down.
I. Designing and planning the haul and access road system. It is im-
portant to plan the access without damaging other resources such as
streams, timber, etc. Careful planning can minimize the amount of
land in roads, thus reducing the amount of acreage disturbed. Design
criteria should include acceptable grades, widths, strength,
durability, drainage and filter strips(2). Factors affecting design
criteria that must be considered in the planning include:
a. The expected traffic volume per unit of time that will be
generated by all probable users.
b. The weight per axle or tire that those users will exert on the
travelway.
c. The time duration through which each user can be expected to
use the road.
117
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d. The speed at which traffic should flow during periods of
maximum traffic volume..
e. The expected ratio of available engine power to gross vehicle
weight for the primary haulage vehicle using the road.
f. The bed width of the haulage vehicle that will "be the primary
road user.
g. The ability of the forest floor below the road to act as a
sediment filter or trap.
2. Location. Based upon the design standards, several alternate road-
ways should be located and evaluated. The routes are selected and
plotted on topographic maps or aerial photos. From the maps and
photos it is easy to determine the slope, aspect, grade, and pinpoint
obstacles that must be avoided (such as rock outcrops, natural scenic
formations, property lines, and wet areas).
After the roads have been tentatively located on maps, they are walked
on the ground and the centerline flagged. Adjustments in grade or
alignment are made by the locating party instead of the construction
crew(3). Road locations may be changed several times before the final
route is selected. All flagging except that marking the final route
should be removed in order to avoid confusion during construction.
3. Construction and drainage. Actual construction should always be
performed in dry weather. ¥et materials in the subbase and base of
the road will not dry out and may heave if the material freezes.
Trees and brush should be windrowed at the toe of the fill to act as
a sediment filter and add support for the fill section. Organic
material should never be buried in the fill section, as it cannot be
compacted and upon decaying will serve as passageways for water.
Water entering the fill will result in a saturated condition causing
slips and slides.
Six feet (1.82 meters) beyond the cut bank and 3 feet (.91 meters) be-
yond the toe of the fill should be cleared to help the roadbed dry
out faster after a rain. Cutting rather than bulldozing is re-
commended, because the ground litter isn't disturbed and erosion is
reduced'3).
Experience has shown that a protective strip of absorbent undisturbed
forest soil between the road and stream usually prevents muddy road
water from reaching streams. This strip, often called a filter strip,
should be wide enough to absorb all the muddy water that runs off road
surfaces. A minimum distance of 100 feet (30.5 meters) is recommended
between the road and stream(6). Seeding of the overcast soil and road
shoulders immediately after construction will help minimize erosion
and stream sedimentation. If this cannot be done or is not effective,
install sediment catch basins.
118
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Roads for all weather use and, high speed with heavy equipment need
a surface or wearing course in addition to the subbase and base
course. A variety of materials can be used for surfacing: "slag,
crushed stone, reddog, stream gravel and many others. The material
chosen should be sound, durable, and not contain acid producing or
toxic elements that could cause stream pollution. Unburned coal
refuse and waste should never be used for surfacing.
The usefulness and permanence of roads depends on how well they are
drained. It is poor economy to skimp on drainage. Uncontrolled water
will erode and break up road surfaces, thus destroying their useful-
ness and increasing maintenance costs.
Drainage control structures are one of the most important items on
any roadway. Their design depends on the length of time that the road
will be used and the hydrologic data for the area. During the field
reconnaissance, the location, type, and size of drainage structures
are noted. Most States have sizing charts, and techniques used by
their highway departments for culvert and drainage structures design.
These charts and techniques are easily adapted for use on coal-haul
roads v2).
Maintenance. If a road is to be kept serviceable and properly drained
and prevented from having an undesirable effect on stream water
quality, then maintenance is required. Basically, maintenance is
keeping the drainage system functioning properly and grading the road
to its original shape (Figure 69). Maintenance costs can be minimized
if the road was designed and constructed according to good engineering
principles and if timely repairs are made in a proper manner. In most
cases, maintenance is applied only to smoothing of the road surface,
and drainage facilities receiving little attention until their failure
damages the travelway itselfC2). All ditches, culverts, and bridges
must be inspected on a regular schedule and repaired or cleaned when-
ever damaged or obstructed. At no time should grading leave a berm
between the roadbed and the ditch line. When pulling ditches, the
backslope should not be undercut because this will cause sloughing
into the ditch and result in washout and bank erosion(s). Daylighting
heavily shaded roads by cutting away overhanging trees so that the
road will dry quickly from exposure to sun and wind is good
preventive maintenace.
Abandonment and bedding down. When a haul road is abandoned, steps
must be taken to minimize erosion and establish a vegetative cover(3).
For complete abandonment, culverts and other structures are removed,
and the natural drainage pattern is restored. Side ditches should be
obliterated and properly spaced grade dips or water bars should be
constructed to handle roadway cross drainage. A water bar must be
placed at the head of all pitch grades, regardless or spacing(2). All
road surfaces must be ripped, treated with soil amendments, seeded
with grasses, legumes, and trees, and mulched. Seeding will help
stabilize the abandoned roads, provide food for wildlife, and improve
the aesthetics.
119
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Figure 69. Properly constructed and maintained coal haul road.
An effective program to check erosion from haul roads must consider all
phases, and specific procedures must be established for each one during
the planning stage. Knowledge is currently available on all phases of
haul-road life. Applicable criteria have been developed by the U.S.
Forest Service through years of engineering study and experience (2,3,6,7)
The U.S. Environmental Protection Agency, Region X, has developed guide-
lines for the construction of logging roads that have been modified for
mine-access roads and are presented in Appendix D.
Many States include haul-road standards in their surface mine regulations
and require these roads to be bonded (Kentucky, West Virginia, Tennessee,
Ohio, and Montana).
West Virginia Surface Mining Regulation 20-6, Series VII, Section 5, is
a representative example of State access road controls (see Appendix E).
120
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SUMMARY
Coal haul roads contribute to stream sedimentation. Sedimentation may occur
in varying amounts in three time frames — construction, operation, and post
operation. Post operation can "be the period of most severe erosion. Research
and experience has shown that damages from haul roads can "be largely prevented
by conscientious application of specific guides for design, location, construc-
tion, maintenance and abandonment. Knowledge is currently available on all
phases of haul-road life and procedures must be established for each one during
the planning phase. Established guides, however, cannot be substituted for
good Judgement in designing and locating coal-haul roads.
121
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REFERENCES
1. Surface Mining and our Environment. U.S. Department of Interior, Wash-
ington, B.C., 1967.
2. Davis, Grant, Strip-Mine Reclamation in Appalachia, (Review Draft). U.S.
Department of Agriculture, Forest Service, Northeastern Forest Experiment
Station, Berea, Kentucky, July 1971.
3. Weigle, Weldon K., Designing Coal-Haul Roads for Good Drainage. Central
States Forest Experiment Station, U.S. Department of Agriculture, Forest
Service, Berea, Kentucky, 1965.
U. Schmidt, R.A., and Stoneman, W.C., A Study of Surface Coal Mining in
West Virginia. Stanford Research Institute, Menlo Park, California, 1972.
5. Curtis, Willie R. Effects of Strip-Mining on the Hydrology of Small
Mountain Watersheds in Appalachia. Northeastern Forest Experiment Station,
Forest Service, U.S. Department of Agrilculture, Berea, Kentucky 1969.
6. Kochenderfer, James N. Erosion Control on Logging Roads in the Appalachians,
U.S. Department of Agriculture, Forest Service, Research Paper NE-158,
Upper Darby, Pennsylvania, 1970.
7. Guides for Controlling Sediment From Secondary Logging Roads. U.S.
Department of Agriculture, Forest Service, Intermountain Forest and Range
Experiment Station, Ogden, Utah, and Northern Region, Missoula, Montana.
122
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SECTION VIII
RECLAMATION COSTS
INTRODUCTION
The cost of reclamation can vary widely, depending on the primary objectives of
the restoration activities. Statistics in this study originated from State
files, publications, and personal communications relating to restoration and
pollution control measures for previously mined lands (orphan lands) and active
mines.
Reclamation of orphan lands is generally considered a public burden and con-
stitutes an economic problem. All work reported here was completed under
government contract, by the lowest bidder, with money coming from State and/or
Federal funds. Cost would have been substantially lower had the reclamation
been concurrent with mining. Several persons connected with some of the pro-
jects have observed that costs could probably be reduced by at least one half,
if the reclamation had been conducted along with the mining. The expense of
clearing and grubbing of volunteer vegetation, disposal of buried trees and
brush, loosing of compacted spoil, and re-establishing access to areas could be
saved. In addition, a contracting firm doing the work for a government agency
would have mobilization costs and receive a profit. Mining companies also are
profit conscious and would consider these costs in anticipating their profits
(e.g., overhead would be less if reclamation is integrated with mining).
The data presented here should serve as a guide for estimating and determining
cost ranges, however, it should be recognized that variations exist. Adjust-
ments may be necessary from the standpoint of physical conditions, economic
conditions, price changes, and more restrictive requirements of recent surface
mining laws.
Reclamation conditions, procedures and successes in the eastern United States,
particularly in Appalachia, have no bearing on conditions to be expected in the
western United States. The situations are wholly different. Reclamation in
the West differs from that in the East, primarily because of aridity especially
during the summer monthsvl). Because of the many variables and differences
between reclamation in eastern and western areas, they will be discussed
separately.
123
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EASTERN SURFACE MINING RECLAMATION
Since cost considerations are different between orphan lands and active mines 4
each type of reclamation is discussed separately.
Orphan Lands. The cost analysis for Pennsylvania (Table 8) was prepared from
information in the State files at Harrisburgfe). Selected projects were
evaluated for the various mine drainage pollution control techniques completed
during the construction phase of the Moraine State Park. A detailed report is
now available that covers all phases of this project (3).
Ohio information (Table 9) was obtained from State files in Columbus
Twenty projects were evaluated dating back to 1965. All projects were
reclaimed with money collected as a result of bond forfeitures . Expenditures
on a given tract of land are limited to the amount of bond forfeited on that
land. Where the bond forfeited on any given area of land is insufficient to
pay the cost of doing all the reclamation work, the State was required to pur-
sue reclamation only to the extent that such money permitted. Tree planting
had top priority, and if any money remained, other pollution control measures
were included. In most cases, only sufficient funds for. tree planting were
available .
Kentucky furnished the information (Table 9) for 5 projects that were reclaimed
with bond forfeitures and State money from a special reclamation fund(5). The
Kentucky law requires that bond forfeitures be spent on the land for which the
bonds were forfeited. However, they can also spend additional money from a
special reclamation fund to do total reclamation for pollution control.
The information for West Virginia (Table 9) was furnished by the State for
eight projects (6). These projects were reclaimed with money from a special
reclamation fund that could only be spent on surface mine problems .
Tables 10 and 10A are based on data collected from several Federal Government
publications, an environmental impact statement (Palzo Project), Myles Job
(Breck & Brooks), and a personal communication (TVA). See Appendix F for a
detailed breakdown of Table 10 -
Active Mines . Available information for active operations is sketchy and
probably not very accurate. For example, a survey by the U.S. Bureau of Mines
of reclamation work conducted in 196U by the major surface mining industries
(Table 11) showed that in the principal coal-producing areas, average costs of
completely reclaiming coal lands ranged from $169 per acre in the South
Atlantic States to $362 in the Mid-Atlantic area. Partial reclamation costs
ranged from $7^ per acre in the East South Central region to $26l in the Mid-
Atlantic -. Detailed are lacking as to the exact type or degree of reclamation
represented by the costs reported, but the level was probably influenced by
legal requirements of the seven States that had surface mining laws. The cost
also might have been influenced by the fact that reclamation work was conducted
with the mining operation, and the extra expense of repairing access roads to
move heavy equipment back to the site was avoided (1*0.
12U
-------
Table 8. SUMMARY OF RECLAMATION COSTS, COMMONWEALTH OF PENNSYLVANIA
Pollution Control Measures
Backfilling and grading:
1. Approximate original contour:
2. Terracing
Re ve get at ion:
1. Trees only — 700/acre
2. Grasses and legumes - 19 lb/acre
3. Grasses, legumes, and trees
Diversion ditch:
1. Cross section, 10 sq ft
2. 6 ft. Bottom, side slopes l?g to 1
3. Rock protection for ditch
Reconditioning stream bed
Curtain grouting of outcrop
Mine seal, bulkhead type
Coal refuse pile (gob):
1. Removal and grading
2. Contouring and grading pile
3. Top soil:
a. Clearing and grubbing borrow
area
b. Excavation and covering refuse
h . Drainage :
a. Ditch
b. Pipe and laying
5. Re ve get at ion
UnltU)
Acre
Acre
Acre
Acre
Acre
LF(2)
LF
Sq Yd
LF
LF
Each
Cu Yd
Cu Yd
Acre
Cu Yd
LF
LF
Acre
Cost
Maximum
$1,522.00
1,500.00
500.00
220.00
500.00
1.00
lU.90
12.00
1.50
11.87
7,000.00
1.06
1.00
700.00
2.00
2.60
20.00
900.00
Minimum
$1,000.00
700.00
90.00
180.00
386.22
—
7-93
— — —
1.00
5.80
6,000.00
1.00
0.33
187.50
0.26
1.67
10.00
100.00
= O.UO hectares; foot = 30.U8 centimeters; sq yd = 0.81* sq meters;
cu yd. =0.76 cubic meters.
'^'Linear foot.
125
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Table 9. SUMMARY OF RECLAMATION COSTS:
STATES OF OHIO, KENTUCKY, AND WIST VIRGINIA
Pollution Control Measures
Cost
Unit
.(1)
Maximum
Minimum
Ohio:
Backfilling and Grading
1. Strike-off
2. Terracing
Revegetation
1. Trees only
2. Grasyes and legumes
Acre
Acre
Acre
Acre
$181.23
21U.09
50.00
50. lU
$169.86
1*7.31*
22.07
38.09
Kentucky:
Backfilling and Grading
1. Approximate original contour
2. Terracing
Revegetation
1. Grasses, legumes and trees
Acre
Acre
Acre
1,200.00
185.00
150.00
171.00
167.00
1*0.00
West Virginia:
Backfilling and Grading
1. Approximate original contour
2. Georgia V ditch
Revegetation:
1. Grasses, legumes, and trees
Acre
Acre
Acre
61*1.23
600.00
287.69
211.57
90.00
Acre = 0.1*0 hectares
126
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ro
Table 10. SUMMARY OF COSTS: MINE RECLAMATION CONTROL MEASURES
(DOLLARS)
Pollution
Control
Measures
Surface Back-
filling by
grading:
1. App.Orig.
contour
2 . Terracing
3. Swallow tail
U. Pasture
5. Final pit only
Surface back-
filling by
using
explosives :
1. Terracing
Scalping
Clearing and
Grubbing
U.S. Bureau
of Mines
#6772
(7)
11.70 to
15.73/LF
5/1&/LF
— —
8,8U to
1U.08/LF
— _
U.S. Bureau
of Mines
#81*56
(8)
780 to
l,lj-02/acre
— .
— — —
___
33, 5U to
U5.76/acre
MYLES
JOB
(9)
250 to
UOO/acre
— — —
U60/acre
U.S. EPA
ELKINS
(10)
U72/acre
5 82 /acre
568/acre
— —
— — —
25 to
l6U/acre
T V A PALZO
PROJECT
(11) (12)
650 /acre
600/acre
UOO/acre
7, 300 /acre
"••"•" ••— —
75 /acre
100/acre
U.S. EPA
TRUAX-TRAER
(13)
— — —
• •"—
Re vegetation
Municipal waste
sludge,liquid:
1. Irrigating
2. Incorporating
-12"
to
282/acre
500/acre
100/acre
-------
Table 10, Continued.
ro
00
Pollution
Control
Measures
Dry
1. Hauling
2. Application
U.S. Bureau
of Mines
#6772
(7)
U.S. Bureau
of Mines
#81*56
(8)
___
—
MYLES
JOB
(9)
___
U.S. EPA
ELKINS
(10)
T V A
(11)
PALZO
PROJECT
(12)
U.S. EPA
TRUAX-TRAER
(13)
12 /hour
. 12/ton
Masonry seals:
1. Dry
2. Wet
Clay Seals
Treatment for
refuse piles and
slurry ponds:
Soil Cover:
1. If" cover
2. 12" cover
3. 2k" cover
Straw mulch
application
Limestone
Fertilizer,
6-2k-2h
Rototilling 8"
Discing 8"
Handraking
2,212 each
U,076 each
950 each —-
1.00 cu yd
1.00 cu yd
1.00 cu yd
30/ton
27/acre
5.50/ton
55.30/ton
6/acre
3/acre
3/acre
1 Acre = O.UO hectares; Foot = 30.1*8 cm; Sq. yd = 0.5U sq. mi; Cu yd = 0.76 cu m;
Short tons = 0.907 metric tons.
Note: Numbers in parenthesis, in column headings, refer to references at the end of the section
-------
Table IDA. RECLAMATION COSTS: EPA, DENTS RUN PROJECT,
BRIDGEPORT, WEST VIRGINIA
Cost per acre
Item
Job !,(*)
section G,
strip R .
(l6 acres )^c'
Job 2^)
section G,
strip A
( 10 acres )
Job 3,(b)
section C,
strip B and C
(22.8 acres)
Description of vork:
1. Grading
2. Lime
3. Fertilizer
h. Seeding and planting
5- Mulch
Total/acre
Total Cost(e)
$3300, v
25(d)
kQ
2kl
173
$3787
$60,592
$2820
85
51
219
192
$3367
$33,670
$3825, %
92(d)
U9
216
192
$U37^
$99,727
(a)
'Job 1 = Construction consisted of: Modified contour backfill,
diversion ditches, rip rap outslope, compacted backfill
(auger holes), 1973.
Job 2,3= Construction consisted of: Same as above except for grading
which was pasture backfill, 1973.
(c'Acre = OAO hectares
Cost includes water treatment of impounded mine water.
total (3 jobs) = $193,989
In a 1971 study of surface coal mining in West Virginia/1^) Stanford Research
Institute concluded that the total reclamation costs of complying with existing
surface mining laws and regulations range from about $500 to $1000 per acre, not
including sedimentation costs. When these are added, the total would be raised
to about $650 to $1200 per acre for a nominal range of conditions. More
difficult reclamation terrain would require additional costs over and above
these, which could raise the total to about $2500 per acre- The variations in
cost are a result of the displaced overburden being rehandled in northern
West Virginia while spoil cast downslope in the south was not graded
Mathematica Inc.^) found that reclamation costs of active mines are virtually
unknown, even to the mine oeprators themselves, and results of past studies have
varied widely in many cases . The report contains an analysis of the economics
of surface coal mining in eastern Kentucky. Reclamation requirements in the
1971 West Virginia law are quite similar to those now in force in Kentucky,
However, West Virginia does require that highwalls be reduced to 30 feet and
129
-------
U)
o
Table 11. COST OF RECLAIMING LAND DISTURBED BY STRIP AND
SURFACE MINING IN THE UNITED STATES IN 1961*(a)
Coal
Completely reclaimed
Geographic Area
New England
Middle Atlantic
South Atlantic
East North Central
East South Central
West North Central
West South Central
Mountain
Pacific
Total
/i_
Acres v°
.__
l*,3l*3
760
12,1*76
2,920
987
32
13
10
21,51*1
Contract
\
1 Total
.__
$1,573,511*
128,570
2, 391*, 728
731*, 075
90,209
30,81*0
631
1*,000
1*, 956, 567
cost
Average
per acre
.„
$362
169
192
251
91
961*
1*9
1*00
230
Acres
___
1,763
1,788
I*,l62
2,1*31
l*5l*
301*
283
11,185
Partially reclaimed
Contract
Total
___
$1*60 ,780
173,203
70l*,30l*
179 ,796
57,275
67,293
27,076
—
1,669,727
cost
Average
per acre
^^«k
$261
97
169
7!*
126
221
96
—
ll*9
(a)
As reported voluntarily by producers on U.S. Department of Interior Form 6-1386X and 6-1387X.
Acre = 0.1*0 hectares
Source: Reference (ll*) at the end of this section.
-------
that topsoiling be provided where acid-producing materials are present. Thus,
"backfilling costs will be higher than those in eastern Kentucky, where high-
wall reduction and topsoiling are not required. The study lists major
variables that have a decided effect on reclamation cost (Table 12).
Table 13 shows estimated production costs based on an average stripping ratio
of 8:1. That ratio is representative of surface mines in eastern Kentucky at
today's coal prices. Total production costs, under the stated assumptions,
are $U.17 per ton. It is interesting to note that the stripping costs account
for 58$ of the total per ton production costs; and reclamation costs, when
totaled, account for about 8$.
Summary. The cost figures presented are indicative and show the importance of
preplanning reclamation and incorporating it with the mining cycle. Re-
clamation costs can be reduced significantly if restoration is concurrent with
the mining. Griffith et al.u) estimated that the cost of contour backfilling
eould be reduced by two thirds if done immediately following mining. Early
reclamation avoidsthe cost of removing vegetation, burying toxic materials,
providing access and moving heavy equipment back into the area. If mined land
is allowed to remain bare for any length of time, landslides can develop on
steep slopes; erosion and sedimentation can become excessive. Thus, prompt
reclamation is essential to reduce not only reclamation costs but more
importantly, environmental degradation.
Costs for reclamation of orphan land varies considerably, depending primarily
on the condition of the land, and the desired result. To obtain averages,
mediums, etc. from the data presented in this report would be misleading.
Based on the experience and judgement of the authors, the following ranges of
cost are presented for reclamation in 197^- where reclamation is performed by
contractors under bid cost:
Desired results and condition of land: Range/acre*
l) Trees only — land does not require grading
or soil amendments and is not toxic $ 50 - $ 150
2) Grasses and legumes— land does not require
grading, but does require liming, fertilizer,
seedbed preparation, and seeding $ 100 - $ 1+00
3) Complete reclamation— land requires grading,
water control, soil amendments, mulching,
seedbed preparation, seeding, etc $1,800 - $U,000
* Acre = O.J+0 hectares.
Variables affecting cost of reclamation for active mines have been mentioned.
Table ik has been prepared to place these costs in perspective to the coal
being mined on a tonnage basis.
131
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Table 12. STRIP MINE RECLAMATION PROJECTS
VARIABLES AFFECTING BACKFILLING AMD GRADING COSTS
1. Geographic location.
2. Topographic setting (original, prereclamation a*1*1 final ground slopes).
3. Type of strip mine;
a) Area, b) contour, c) area-contour, d) other.
k. Coal seams mined and thickness.
5. Inclination of coal seams in back of highwall:
a) dip, b) rise, c) horizontal.
6. Condition of coal seams in back of highwall:
a) not mined, b) auger mined, c) drift mined (entries opened or
caved), d) mine workings exposed by stripping operation.
7. The probable hydraulic head that could develop if coal in back of highwall
was mined.
8. Strip mine area information:
A. Length, width, and area (acres) covered by spoil before reclamation
B. Highwall height (maximum and average height)
C. Highwall length
D. Number of cuts
E. Total area affected during reclamation in acres (including area above
highwall and outside of slopes)
F. Volume of spoil to be moved (cubic yards)
G. Average haul distance for backfilling and grading
H. Texture of spoil
I. Amount of large rock and material requiring special handling (mining
timbers, machinery, and debris, junked cars, and other solid waste)
J. Amount and reactivity of pyritic material (minerology and mode of
occurrence. For example finely dispersed; single crystals or crystal
aggregates; coatings on joint suffaces; in form of lenses, layers or
modules; "sulfur balls"; pyritic shales, etc.)
K. Clearing and grubbing requirements.
9. Type of backfill:
a) contour, b) pasture-reverse slope, c) swallowtail, d) head of
hollow, c) submergence, f) other.
132
-------
Table 12, Continued
10. Physical sealants for covering toxic material.
a) none, b) clay, c) bituminous material, d) plastic material,
e) other.
11. Compaction desired:
a) none, b) only toxic materials, c) all spoil material with
exception of upper layer (l to 3 feet).
12. Accessibility factors:
A. Right-of-way problems
B. Ingress and egress construction (include clearing and grubbing
for access and post-construction revegetation)
C. Other factors affecting access,
13. Surface and subsurface ownership of strip-mined area. Also, ownership
of properties for ingress and egress:
a) public, b) private, c) in process of being acquired or line
placed on property, d) abandoned, e) temporary easement, f) other.
1^. Time of year reclamation performed.
15. Weather conditions during reclamation period(s).
Source:Reference (16) at the end of this section.
133
-------
Table 13. ESTIMATED AVERAGE PRODUCTION COSTS @ AVERAGE
STRIPPING RATIO = 8:1 and 0,5 ACRES DISTURBED
PER THOUSAND TONS OF COAL PRODUCED*
Cost Element
Sediment structure
Acreage fees
Bonding
Scalping
Stripping
Overburden haulage
Coal loading
Coal haulage
Backfilling and grading
Re vegetation
Royalties
Severence tax
Cost ($/ton)
0.12(1)
0.01(1)
0.00
0.08(1)
2.1*0
0.05
0.10
0,50
0.08(1)
0.03d)
0.50
0.30
Cost (% of total)
2.9
0.2
0.0
1.9
57.5
1.2
2.1*
12.0
1.9
0-7
12.0
7-3
Total $1*.17 100.00
JOL
Acre = 0.1*0 hectares; short tons = 0.907 metric tons.
(•'-'Reclamation costs. These costs are equivalent to $0.32 per ton or 1.6%
of the total costs.
Note: The primary assumptions underlying these estimates were that the
stripping ratio- is 8:1; the cost balance would change somewhat if the
assumed stripping ratio were changed.
Source: Reference (l6) at the end of this section.
13U
-------
Table lU. APPROXIMATE RECLAMATION COSTS PER TON OF COAL MINED BY STRIPPING
co
VJl
State
Illinois
Indiana
Kentucky
Eastern
Western
Ohio
Pennsy 1 vani a
Tennessee
West Virginia
Virginia
Montana
Subbituminous
Subbituminous
Lignite
Average Calculated
Thickness Production
Per acre
80$ recovery
(feet) (tons)
5.0
U.6
3.1
5.1
3.U
3.2
3.2
U.9
U.I
30.0
50.0
16.0
7520o(a)
6,62U(a)
U,U6U(a)
7,3UU(a)
5,328(a)
U,603(a>
U,176(a)
7,056(a)
5,90U
-------
WESTERN SURFACE MINING RECLAMATION
Strippable coal reserves of the West are becoming increasingly important^
because of their magnitude and low sulfur content. Stringent air pollution
regulations are causing coal-using industries to seek the western low-sulfur
coal. Western coal lies in seams up to 100 feet (30.5 meters) with overburden
depths up to 200 feet (6l meters). Considering these facts alone, it is safe
to assume that in the immediate future there will be a tremendous expansion of
the surface mining industry in the West. Obviously reclamation costs on a
per-ton-of-coal-mined basis in the West will be much lower than the East
(Table lU). However, the reclamation costs per acre (hectare) could reason-
ably be higher because of the semi-arid to arid conditions that require more
sophisticated restoration techniques than those practiced in the East (See
Section IX, Revegetation).
Costs estimated for reclamation are scarce, mainly because of the small scale
of coal strip mining in the past and the lack of State requirements. The
Burlington Northern Railroad is reclaiming approximately 1,000 acres (U05
hectares) of orphan land in eastern Montana. These acres were surface mined
between 1923 and 1958 and reclamation work began on September 13, 197^-
Currently more than 580 acres (235 hectare) have been contoured, seeded, or
prepared for seeding at a cost of $600 per acre, for a total of $390,000 to
date.
Remaining contouring and seeding is estimated to cost another $UOO,000 with
completion anticipated in late 197^, (17).
The Ozarks Regional Commission is sponsoring a regional project to demonstrate
that mined land can be restored to productive use. This project is known as
"Mined- Land Redevelopment", and in 1973 it included Kansas, Missouri and
Oklahoma. Demonstration sites vary in size from 20 to 150 acres (8 to 6l
hectares) and are orphan areas. Although the majority of acreage reclaimed
was for grassland, other uses such as catfish farming, recreation, housing,
industrial parks, and solid waste disposal were also demonstrated.
All the grassland sites have been reclaimed to the following specifications:
1. Spoil banks are graded until slopes on 90$ of land area are 10$ or
less. Remaining land can have slopes up to
2. The entire area adjacent to the water pits slopes to within k feet
(7.35 meters) of the water, except for the highwall side. Slope
specifications are the same as 1.
3. Soil testing is done on the grid pattern, with four samples per acre
taken and composited for pH testing.
U. Soil treatment (lime and fertilizer) is furnished as recommended by
the agricultural extension agent.
5- Wood and brush control management is employed.
6. Annual applications of fertilizer are made if needed.
136
-------
One-tenth of the orphan land in Kansas has been reclaimed to productive use by
this project. Costs are shown in Table 15.
The Kansas figures would have been higher if the reclamation had been performed
by contractors under bid costs instead of by local persons with a vested
interest.
The leveling of spoil piles is the major cost factor in reclamation. Costs
vary greatly for backfilling and grading of overburden because of the various
degrees of leveling that are performed.
For example, grading to a rolling topography does not stipulate the minimum
grade that is to be attained. Thus, there is no standard to follow in
determining the quantities and distance that the overburden must be moved.
To be meaninful, any cost data must state the type of backfilling and leveling
to a predetermined grade. Tables l6, 17, and 18 taken from the Land Reclama-
tion Task Force, North Central Power Study (l8) should prove helpful when
calculating the amount of overburden to be moved and the cost of moving it
when either complete or partial leveling is desired. The figures in Table 18
are subject to change from operation to operation and will increase as other
costs rise.
In summary, there is insufficient information from orphan and active western
mines to provide data for analysis. Rough estimates can be obtained by using
eastern mining data, but even these data are questionable. A major research
need is the development of cost data and an investigation of the factors that
affect these costs. The various factors listed in Table 12 need to be studied
to determine how they influence the cost of reclamation for both the orphan
and active mines in the eastern and western coal fields.
Table 15- RECLAMATION COSTS PER ACRE FOR
KANSAS MINED LAND DEMONSTRATION SITES,
MAY 1973
Item
Grading
Lime (all sites)
(lime users)
Fertilizer
Seedbed preparation
Seeding
Total
Number of
Sites
68
61
38
61
61
61
6
Acres*
1,307
1,188
676
1,188
1,188
1,188
Range
$120 -
$
$
$
$
$
0 -
1 -
0 -
1 -
u -
$136 -
($/A)
$508
$ U2
$ U2
$ 27
$ 62
$258
$551
Weighted
Average
$158
-------
Table 16. CUBIC YARDS OVERBURDEK TO BE MOVED PER ACRE*
PER CEUT GRADE
V;idth
of pit
50
60
TO
eo
90
100
^^j
U. 110
120
130 10
ll*0 11
150 12
160 12
170 13
0
1*031*
1*81.0
56U7
61*5*.
7260
8067
8871*
9680
,1*87
,291*
,100
,907
,711*
2
3933
1*719
5506
6293
7079
7865
8652
91*38
10,225
11,012
11,798
12,581*
13,371
1*
3832
1*598
5365
6131
6897
7661*
81*30
9196
9963
10,730
11,1*95
12 ,262
13,029
6
3732
1.U77
5221*
5970
6716
71*62
8209
8951*
9701
10,1*1*7
11,193
11,939
12,686
8
3631
1*356
5063
5809
6531*
7261
78,987
8712
91*39
10,165
10,890
11,617
12,31*3
10
3530
1*235
1»9!*2
561.8
6353
7059
7765
81*71
9177
9883
10,583
11,291*
12,000
12
3U29
Itlll*
1*800
51*86
6172
6857
751*3
8229
8911*
9600
10,286
10,971
11,658
ll*
3328
3993
1*659
5325
5990
6656
7321
7987
8652
9319
9983
10,61*9
11,315
16
3228
3872
1*518
5161*
5809
61.5U
7100
771*5
8390
9036
9681
10,326
10,972
18
3127
3751
1*377
5002
5627
6253
6878
7503
8128
875U
9378
10 ,001*
10,629
20
3026
3630
1.236.
1*81*1
5U1*6
6051
6656
7261
7866
81*72
9076
9681
10 ,287
22
2925
3509
1*095
1*680
5265
581*9
61*31*
7019
7601*
8190
8771*
9358
991.1*
2U
1821.
3388
3951*
1*5 18
5083
561*8
6212
6777
731*2
7908
81*71
9036
9602
26
2721*
3267
3813
1*357
1*902
51*1*6
5991
6535
7080
7625
1869
8713
9259
28
2623
311*6
3672
1.196
1*720
521*5
1769
6393
6818
731*3
7866
8391
8916
30
2522
3025
3530
1*035
1*539
501.3
55U7
6052
6556
7061
756U
8068
8571*
32
21.21
290U
3389
3873
1*356
1.81*1
5325
5810
6293
6779
7262
771.5
8231
3U
2320
2783
321*8
3712
1*176
1*61*0
5103
5568
6031
61*97
6959
7>»23
7888
180 ll*,521 H.,158 13,975 13,1*32 13,069 12,707 12,3V* ll,98l 11,168 11,255
190 15,327 ll*,9Wt ll*,56l ll*,178 13,795 13,1*12 13,029 12,61.6 12,263 11,880
200 16,131* 15,730 15,328 lU,92l* H*,521 lU,ll8 13,715 13,312 12,908 12,505
Acre = 0.1(0 hectares; Cu yd = 0.761* cu m; foot = 0.301* meters.
Note: Width of pit is in feet. Source: Reference (18) at the end of this section.
10,892 10,529 10,166 9803 9V*0 9077 8715 8352
11,1*97 11,111* 10,731 10,31*8 9965 9582 9199 8816
12,102 11,699 11,296 10,892 10,U89 10,086 9683 9280
-------
Table 17. COST PER CUBIC YARD OF MATERIAL MOVED (1,2)
Length of Push Cubic Yards Moved Cost Per Cubic Yard
(ft.)* Per Hour(3)»
50'
55'
60'
* »
65'
70'
75'
80'
85'
90'
95'
100'
^ 'Source: Reference (l
61*0
600
565
5l*0
515
500
1*80
1*65
1*50
1*30
1*15
8) at the end of this sectic
$0.027
0.029
0.031
0.032
0.033
0.031*
0.036
0.037
0.038
0.01*0
0.01*2
>n.
(2)TD_25 Tractor with a semi "U" blade was used in calculating this table,
(3'Fifty-minute hour, 80% efficient.
* foot = 0.30l* meters; cu yd = 0.761* Cu meters.
STRIP MINING ECONOMICS*
For any organization, including the non-profit ones, the objective of
economic performance is supreme. The economic decision-making process involves
many factors some within and many outside the mining company's control.
The physical and chemical attitudes of the coal seams and their overburdens are
more easily obtained. Selection of the right equipment, and method for
shipping and coal recovery, though difficult, can be achieved. The legal and
social outlooks, on the otherhand are more unpredictable. Their effects on
costs are more critical, and therefore, more important to evaluate. It has
been contended that reclamation requirements not only add directly to the
mining cost but indirectly escalate the cost by decreased productivity.
Capital cost considerations can hardly be over-emphasized. However, equipment
costs vary widely, and are a function of the amount of steel and the fabrica-
tion in the design and construction of the equipment. Cost involved for other
Surface facilities (e.g., storage, office space, buildings, etc.) are also
subject to great regional variances. Also the financing and accounting pro-
cedures of companies differ, thereby making it difficult to arrive at meaning-
ful comparisons.
This was written by Dr. R.V. Ramani, Associate Professor of Mining Engineer-
ing, The Department of Mineral Engineering, The Pennsylvania State University.
139
-------
Table 18. COST PER ACRE FOR LEVELING OVERBURDEN PILES*
PER CENT GRADE OF LEVELED PILES **
Width
of pit 0 2 1* 6 8 10 12 ll* 16 18 20 22 2k 26 28 30 32 35
50 $108.92 106.19 103.1*6 100.76 98.01* 95.31 92.58" 89.86 87.16 81*.1*3 81.70 78.97 76.25 73.55 70.82 68.09 65.37 62.61*
60 $130.68 127.1*1 124.15 120.88 117.6l IiU.35 111.08 107.81 105.5!* 101.28 98.01 95.75 91.1*8 88.21 81*.9!* 81.68 78.1*0 75.ll*
70 $152.1*7 11*8.66 1U5.86 iUi.05 137.2l» 133.U3 ''129.60 -125.79 121.99 118.18 115.37 110.57 106.76 102.95 99.1** 95-31 91.50 87.70
80 $17U.26 169.91 165.51* 161.19 156.81* 152.50 ll*8.12 1U3.77 139.1*3 135.05 130.71 126.36 121.99 117.65 113.29 108.95 105.57 100.22
90 $196.02 191.13 186.22 181.33 176.1*2 171.53 166.65 161.73 156.81* 151.93 157.05 152.16 137.21* 132.2!* 127.1*1*122.55 117.61 112.75
100 $217.81 12.35 206.93 201.1*7 196.65 19.0.59 185.ll* 179.71 175.26 168.83 163.37 157.92 152.50 157-05 l5i.62 136.16 130.71 125-28
110 $257-35 250.91 255.57 238.06 231.62 225.19 218.75 212.31 205.90 199.1*6 193.02 186.59 180.15 173.71* 167.30 160.86 15!*.1*3 ll»7.99
120 $300.08 292.58 285.08 277.57 270.07 262.60 255.10 21*7.60 21*0.10 232.59 225.09 217-59 210.09 202-59 195-08 187.6l 180.11 172.61
130 $335.58 327.20 318.82 310.33 302.05 293.66 285.25 276.86 268.1*8 260.10 251.71 21*3.33 23**.9** 226.56 218.18 209.79 201-38 192.97
ll*0 $372.70 363.1*0 351*.09 3l*l*.75 335.1*5 326.ll* 316.80 307-53 298.19 288.88 279-58 270.27 260.96 251.63 21*2.32 233-01 223.71 215.56
150 $1*11.1*0 1*01.13 390.83 380.56 370.26 359.99 31*9.72 339.1*2 329.15 318.85 298.32 288.01 277.75 267-1*1* 257.18 21*6.91 256.91 236.61
160 $1*61*.65 1*53-02 1*1*1.1*3 1*29.80 1*18.21 1*06.58 391*.96 383.36 371.71* 36o.ll* 31*8.52 336.89 325-30 313.67 302.08 290.1*5 278.72 267.23
170 $507.1*2 l*9l*.73 1*82.07 1*69.381*56.69 1*1*1*.00 1*31.35 1*18.66 1*05-96 393.27 380.62 367-93 355-27 31*2-58 329-89 317.2U 30l*.55 291.86
180 $551.80 538.00 52l».21 510.1*2 1*96.62 1*82.87 1*69-07 1*55-28 1*1*1.1*8 1*27.69 1*13-90 1*00.10 386.31 372.51 358.72 355.93 331.17 317.38
190 $613.08 597-76 582.1*1* 567.12 551.80 536.1*8 521.16 505.81* 1*90.52 1*75.20 1*59-88 1*1*1*.56 1*29.21* 1*13.92 398.60 393-28 367-96 352.61*
200 $677.63 660.66 61*3.78 626.81 609.88 592-96 576.03 559-10 51*2.ll* 525-21 508.28 1*91-36 l*7l*-l*3 1*57-1*6 1*1*0.5!* 1*23.6l 1*06.69 389.76
Using the cost from Table 17 and the yardage from Table 16, the cost per acre are calculated for the various widths of pits stripped
and the percent of grade of the leveled overburden piles.
^cre = 0.1*0 hectares; foot = 0.305 meters.
Note: Width of pit is in feet. Source: Reference (18) at the end of this section.
-------
Estimation of the mining costs must "be "by necessity, based on the company's
experience. The labor and material cost must be estimated for drilling,
explosives, overburden removal, reclamation, pit cleaning, coal loading,
haulage, road building, fuel, oil, grease, maintenance, supervision, deprecia-
tion, etc. Additionally, costs for transporting, erecting, dismantling, and
moving the primary stripping and other equipment must be considered. Since the
viability of a project must be determined over the mine life, these have to be
projected into the future taking into account the inflationary and productivity
trends-U9).
A factor clouded with more uncertainties is the selling price of coal. It is
a complex function of the demand and the availability of other energy resources
and their prices. The correlation between the selling price and the mining and
preparation cost, on one hand, and the attractiveness of investment in stripping
on the other, is strong. The most important decision-criteria in strip mining
is the stripping ratio*, defined as the amount of cubic yards of overburden to
be removed to recover a ton of coal. It relates the selling price of coal with
the costs of mining the coal and stripping the overburden. In literature,
sometimes the calculations are based on average overburden depths, though in
reality, the break-even stripping ratio is a point-value, beyond which the coal
seam cannot be economically stripped; i.e. as the overburden depth increases,
more money is spent on exposing the coal seam till a limit is reached when the
value of the recovered material (clean coal) is just enough to pay for all the
cost involved in mining, preparation and selling the material.
It can be unequivocally stated that it is the improvement in technology more
than any other single factor that has not only sustained the coal mining
industry but extended the technique to deeper coal seams. Provided in Table 19
are some salient statistics regarding strip mine performance in 1967»^0).
However, the importance of technological evolution in the ability to strip coal
seams not heretofore possible must be borne in mind. Strip ratios of 25:1 and
greater in 3- and k-ft thick coal seams have been achieved in recent^years.
To give some idea on the capital investment in modern day strip mines, refer-
ence is made to Table 20,(21) which shows significant increases in capital
investment, mining costs and interest rates for opening a mine, 2 million tpy
capacity, under identical conditions in 1973, as compared to opening one in
1958. Thus, for the same return-on-investment before tax, a ton of coal must
realize $7^56 in the market in 1973.
The U.S. Bureau of Mines(20) provides cost estimates for twelve hypotehtical
mines with a 20-year life. Coal seam and overburden data are considered
typical for the hypothetical mine area. The analyses are based on the use of
new equipment, the prevailing wage scale, and the payment of all costs includ-
ing UMWA welfare fund, royalties, license and permit fee. Tables 21 and 22
reproduced here from that report, provide a summary of the study.
"Strip Ratio - Cubic Yards of Overburden
Tons of Recoverable coal
-------
ro
TABLE 19. NUMBER OF STRIP MINES, PRODUCTION, OUTPUT PER MAN PER DAY,
AVERAGE SEAM THICKNESS, AVERAGE OVERBURDEN, AND
AVERAGE VALUE IN 1967, BY STATE*
State
Arkansas .......
Indiana.
Kansas .........
Kentucky — east .
Kentucky — west .
Ohio
West Virginia. .
Total
Number
of
mines
.. 62
U
U
7
U3
37
12
5
.. 66
38
31
13
3
3
2U
. . 273
9
. . 517
1
58
70
1
. . 217
9
..1,507
*Short tons = 0.907 metric
iMost recent data for 1965
Source: Reference (20) at
Production ,
thousand
short tons
6,OU3
925
lUU
1,862
37,185
17,131
588
1,136
5,503
30,282
880
3,691*
329
2,795
U.156
29,209
819
21,98U
5
2,677
U,196
3
12 . 117
3,1*71
187,131*
tons ; foot
. 2Average
the end of
Average
output
per man
per day,
(tons )
28.1*7
21*. 97
13.98
66.39
Ul.59
1*3.39
21.69
23.1*8
37.73
51.91
25.11
33.68
71*. 28
75.37
61*. 76
33.51
20 .92
20.22
9.79
29.25
31*. 79
15. U3
28.99
57.91
35.17
Average
thickness
of seam
mined,
(feetl)
2.5
U2.9
1.8
7.1
5.3
U.2
U.3
1,7
U.3
5.0
5.3
2.U
17.1
11.8
11.5
3.6
1.5
3.2
U.5
2.7
U.5
8.0
U.9
29.7
5.2
= 0.301* meters; cu
value is for all of
this section.
Average
thickness
of
overburden ,
(feetl)
38.7
66.9
29.1
51.0
55.6
U9.0
51.2
39.3
36.1
5U.3
51.0
37.1
60,0
U7.9
Uo.7
50.0
1*3.0
1*8. U
17.0
38.1
U2.6
22.0
Ul.S
U7-.0
50.1
Cubic yards
of
overburden
per short
ton of coal
mined1
17.3
2.0
15. U
7.U
13.6
ll*.l*
15.2
30.2
NA
9.U
UU.7
15.2
7.2
6.1
5.U
lU.3
33.3
17.6
15.0
3U.9
12.0
9.8
11.3
2.9
12.8
Average
value
per
ton,
f .o.b.
mine
$U.85
7.89
7.5U
3.36
3.83
3.87
3.67
U.66
3.262
3.12
U.21
1.98
2.56
1.92
3.59
5.71
3.76
5.003
3.6U
3.U6
7.UU
U.08
3.21
3.68
yd = 0.76U cu meters.
Kentucky. 3Mined for the uranium content.
-------
Table 20. COMPARISON OF TWO STRIP MINES
1958 vs 1973
(Production 2 m tpy)(l)
1.
2.
3.
1*.
5.
6.
Year
Capital Investment
Capital Investiment/ton
Mining Cost
Interest*
Total Cost ( 3 + U)
Realization
1958
$9,700,000.00
it. 85
2.05
0.15
2.20
3.22
1973
$17,500,000.00
8.75
5.18
0,5^
5.72
7.56**
'l-'Short tons = 0.907 metric tons.
* 1^0 percent equity in both cases, 1958 interest 5$, 1973 interest 10$.
** Required realization for maintaining the 1958 ROI (Return-on-Investment).
Source: Reference (21) at the end of this section.
Table 21. SUMMARY OF PHYSICAL DATA USED IN COST ANALYSES*
Production,
million
tons Mine location
per year
Average
coal-seam
thickness,
inches
Average
overburden
thickness ,
feet
Stripping
ratio
(feet to
feet)
Estimated
Average
Btu per
pound^
BITUMINOUS COAL: EASTERN PROVINCE—APPALACHIAN REGION
1
3
Northern West Virginia. .
do
72
72
60
60
18:1
18:1
13,200
13,200
BITUMINOUS COAL: INTERIOR PROVINCE
1
1(2
3
1
Western Kentucky ........
seams \ do
do
SUBBITUMINOUS COAL: ROCKY MOUNTAIN
1
5
5
5
Southwestern United States
.do
66
120
66
16
AND
96
96
300
300
LIGNITE: NORTHERN GREAT PLAINS
1
5
do
120
120
100
100
100
32
NORTHERN GREAT
60
70
75
75
PROVINCE
40
50
18.2:
10:
18.2:
24:
PLAINS
7.5:
8.8:
3:
3:
4:
5:
:1 12,
:l 12,
:l 12,
:1 12,
PROVINCES
:l 10,
:l 10,
:l 8,
:l 8,
= 1 7,
:l 7,
000
000
000
500
600
600
500
500
200
200
As-received basis for raw (unwashed) coal. Average calorific values for
bituminous coal are taken from analyses of face, tipple, and delivered
samples of mostly underground-mined coal and applied to strip coal.
*•
Inch = 25.U millimeters; foot = 0.301* meters;
British thermal units per pound = 2.328 kilojoules per kilograms;
short ton = 0.-907 metric tons.
Source: Reference (20)at the end of this section.
-------
Table 22, SUMMARY OF COST ANALYSES*
Production, Estimated
million capital
tons invest-
per year ment
Operating cost
Dollars
per
year
Dollars
per ton
Cents
per
million
Btu
Selling price,
12-percent DCF
Dollars
per ton
Cents
per
million
Btu
BITUMINOUS COAL; EASTERN PROVINCE--APPALACHIAN REGION
$12,727,500 4,146,400U.15
28,005,000 9,167,100 3.06
BITUMINOUS COAL: INTERIOR PROVINCE
1
3
$12,727,500
28,005,000
4,146,400
9,167,100
4.15
3.06
15.7
11.6
5.40
4.01
20.5
15.2
1 $13,709,800 3,900,100 3-90
1(2 seams) 8,280,100 2,984,300 2.98
3 24,870.100 7,748,400 2.58
1 15,998,000 5,267,000 5.27
16.3 5-35 22.3
12.4 3.81 15.9
10.8 3.46 14.4
21.1 6.95 27.8
SUBBITUMINOUS COAL: ROCKY MOUNTAIN AND NORTHERN GREAT PLAINS PROVINCES
1 $7.898,100 3,025,900 3.03
5 28,656,700 12,030,800 2.40
5 13,879,100 6,943,400 1.39
5 13,921,100 7,892,500 1.58
14.3 3,83 18.1
11.4 3.03 14.3
8.2 1.64 9.6
9.3 1.83 10.8
LIGNITE: NORTHERN GREAT PLAINS PROVINCE
1
5
$6,381,800
20,749,700
2,373,200
8,384,600
2.37
1.68
16.5
11.7
3.01
2.12
20.9
14.7
Short tons = 0.907 metric tons; British thermal unit = 1.055 kiljoules
Source: Reference (20) at the end of this section.
In Table 23 is presented average percent breakdown of cost for 7 strip coal
mines as were experienced in 1969^2^). Labor and supplies each accounted for
nearly 1/3 of the total costs. Table 24 presents estimated per ton production
cost(24). The figures in these tables are to be taken as indicative rather
than conclusive and require adjustment with cost increase indices for use
today.
It is not the purpose here to go into cost analysis models or even present one.
From the discussion thus far, it must be obvious that there is no one model or
method that will give correct answers. Even if the models were analytically
sound, the input data in most cases is proprietary to the company. However,
the U.S. Bureau of Mine's model^20' and other models(22,23) provide valuable
framework for economic analyses of strip mining operations.
144
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Table 23. PERCENTAGE BREAKDOWN OF COSTS,
1969, SEVEN STRIP-COAL MINES
% Total Cost
Labor 32.0
Supplies ,... 32.0
Power. 3.0
Payroll taxes 1.2
Compensation insurance , 1.7
Welfare fund 12.9
Other employee benefits 0. ^
Property & other taxes 1.8
Insurance 0.3
Direct administrative 2.8
Total operating 88.1
Selling 1.6
General adminstration 2.6
Royalties 0.8
Total other cash costs 5.0
Total cash cost 937T
Depreciation 2.1
Depletion 0 A
Amort., development 0.2
Amort., capital ^.2
Total noncash charges 6.9
Total Cost 100.0
Source!Reference (2k) at the end of this section^
-------
Table 2U. ESTIMATED PER-TON PRODUCTION COST
FOR 5,000,000-Tpy STRIP-COAL MIKES*
Direct Cost
Production:
Supervision.
Labor
Supervision.
$0.150
0.037
0.187
0.0^7
0.005
0.052
Total Labor and supervision 0.239
Operating supplies:
Spare parts 0. kOO
Explosives 0.136
Lubrication O.OlU
Diesel fuel 0.025
Tires 0.035
Miscellaneous 0.050
0.660
Power 0. l6p
Union welfare 0. UOO
Royalty ,. 0.175
Payroll overhead 0.08U
Indirect Cost
15$ labor, maintenace,
supplies
Fixed Gost
Taxes and insurance (2% of
plant cost)
Depreciation
Deferred expenses
.$0.135
0.107
0.2l*2
0.133
Annual production cost,
$11,673,306 $2.33
Short ton = 0.907 metric tons
Source: Reference (2l+) at the end of this section.
-------
REFERENCES
1. Curry, Robert R. Reclamation Considerations for the Arid Lands of
Western United States. Testimony for U.S. Senate Interior Hearings
March 1973.
2. Personal Communication. John J. Buscavage and Robert Buhrman, Common-
wealth of Pennsylvania, Department of Environmental Resources,
Harrisburgh, Pennsylvania, 1972.
3. Evaluation of Pollution Abatement Procedures, Moraine State Park.
Environmental Protection Technology Series, EPA-R2-73-11KD, January 1973.
k. Personal Communication. Ernest J. Gebhart, State of Ohio, Department of
Natural Resources, Division of Forestry and Reclamation, Columbus, Ohio,
1972.
5. Personal Communication. John R. Roberts, Commonwealth of Kentucky,
Department for Natural Resources and Environmental Protection, Division
of Reclamation, Frankfort, Kentucky, 1972.
6. Personal Communication, Benjamin C. Greene, State of West Virginia,
Department of Natural Resources, Division of Reclamation, Charleston,
West Virginia, 1972.
7. Griffith, F.E., Magnuson, M.S., and Kimball, R.L. Demonstration and
Evaluation of Five Methods of Secondary Backfilling of Strip-Mine Areas.
U.S. Department of Interior, Bureau of Mines Report of Investigations
No. 6772, 1966.
8. McNay, Lewis M. Surface Mine Reclamation, Moraine State Park,
Pennsylvania. U.S. Department of Interior, Bureau of Mines Information
Circular No. 81+56, 1970.
9. Brock, Samuel M., and Brook, David B. The Myles Job, Office of
Research and Development, Appalachian Center, West Virginia University,
Morgantown, West Virginia, 1968.
10. Scott, Robert B.,Hill, Ronald D., and Wilmoth, Roger C. Cost of
Reclamation and Mine Drainage Abatement — Elkins Demonstration Project.
Water Quality Office, Environmental Protection Agency, National Environ-
mental Research Center, Cincinnati, Ohio, 1970.
11. Personal Communication.Natie Allen Jr., Supervisor, Fuels Engineering
Section, Tennessee Valley Authority, Chattanooga, Tennessee, 1971-
12. Palzo Restoration Project, Final Environmental Statement, Shawnee
National Forest, Eastern Region, Foest Service, U.S. Department of
Agriculture, July 1972.
-------
13. Control of Mine Drainage from Coal Mine Mineral Wastes. Truax-Traer Coal
Company for the Environmental Protection Agency, Washington, D.C., Project
No. 1U010 DDK, 08/71.
1^- Surface Mining and Our Environment. A Special Report to the Nation,
U.S. Department of Interior, 1967.
15. Schmidt, R.A., and Stoneman, W.C. A Study of Surface Coal Mining in West
Virginia. Stanford Research Institute, Menlo Park, California, 1972.
16. Draft Final Report on the Design of Surface Mining Systems in Eastern
Kentucky, Vol. II. Mathematiea Inc., Princeton, New Jersey; Ford, Bacon
and Davis, Inc., New York, New York, April 1973.
17. Personal Communication. John Willard, Regional Manager, Public Relations
Department, Burlington Northern, Billings, Montana, July 1973.
18. Gwynn, Thomas A. et al., Report of the Land Reclamation Task Force: North
Central Power Study, Report of Phase I, Vol. 2, U.S. Department of
Interior, Bureau of Reclamation, March 1971-
19. Staff, Coal Age, Surface Mining and Coal, Guidebook, July 1970.
20. Staff, U.S. Bureau of Mines, Cost Analysis of Model Mines for Strip
Mining of Coal in the United States, Information Circular 8535, 1972.
21. Phelps, E.R., R.O.I, and Coal's Low Profit Margin, Coal Mining and
Processing, March 197^.
22. Falkie, T.V.,and Porter, W.E. Economic Surface Mining of Multiple Seams,
APCOM Proceedings, South African Institute of .Mining and Metallurgy, 1973.
23. McClay, J. A Dynamic Costing Model for Mining Systems, Unpublished
M-S Thesis, the Pennsylvania State University, 197^.
2U. Wimpfen, F.P. Mine Costs and Control, Section 31, SME Mining Engineers
Handbook, AIME, N.Y., New York, 1973.
11*8
-------
SECTION IX
BACKFILLING, GRADING, AND REVEGETATION
INTRODUCTION
Surface mining drastically alters the ecological characteristics of the area
disturbed and in some cases has a decided effect on surrounding areas. Vegeta-
tion is removed, topographic features and characteristics are changed, and the
original geologic overburden profiles are destroyed. Spoil banks generally
are a heterogeneous mixture of rock fragments, rock particles, and soil-sized
material derived from the overburden strata. With proper mining techniques, the
various strata can be partially or completely segregated. Segregation of over-
burden material offers the opportunity to bury the toxic, acid, or salt-pro
producing strata under growth supporting material. In some situations, lower
strata may have more desirable characteristics than surface material and can be
placed near or on the surface. For example, limestone strata appear in some
lower overburden profiles that have shale and/or sandstone near the surface.
Also, some lower strata have higher nutrient levels that have been leached from
the surface.
Experience has shown that natural revegetation is a very slow process on strip
mined areas. Native vegetation may not be compatible with the environment on
the mined areas, for example:
1. Low nutrients in the spoil.
2. Toxic spoils (very acid or highly alkaline).
3. Surrounding vegetation may be of the climax type and may not have
pioneer- or primary-invader-type species present.
U. The seed source may be to far away from the adjacent mined areas.
Early attempts to revegetate strip-mined lands with trees also proved to be
unsatisfactory as they did not provide the initial ground cover required to
stabilize the spoil. Erosion control with trees only may take up to 10 years
before the canopies close and an effective cover is established. They are
slow to form soil profiles and do not provide effective chemical pollution
control until long after planting. A quick growing cover of herbaceous species
is necessary to obtain quick stabilization and initial protection against
erosion by reducing runoff and rain-drop splash. Vegetative cover will also
build up a concentration of organic matter in the soil, which in turn will
-------
support high rates of aerobic bacterial activity, Such a layer will remove
large amounts of oxygen from the soil atmosphere before it reaches the zone
of pyrite oxidization. Caruccio found in his work in evaluation of factors
affecting acid mine drainage, that a soil cover is extremely important in
developing alkalinity and plays an important role in preventing AMDvU.
Vegetation also utilizes vast quanities of water in its life processes and
transpires it back to the atmosphere. Thus, reducing the amount of water
reaching underlying materials. Therefore, a suitable plant cover will not only
control erosion, siltation, and dust, but it will reduce or eliminate acid
formation.
Operations with proper preplanning, mining, backfilling and grading should
present minimal vegetation problems. Orphan areas, on the other hand,
generally have a hostile environment for establishing vegetation, and the
problems are more complex.
REVEGETATION PROBLEMS
Spoil characteristics limit the use and treatment of surface mine areas. The
main factors associated with the establishment and growth of vegetation on mine
spoils have been identified as chemical properties, topographic factors and
physical properties.
Chemical Properties. Acidity in mine spoil is due to the presence of sulfurit-
ic material, particularly iron-disulfide (FeSg) in the coal and overburden
strata. Either directly or indirectly it is one of the major factors limiting
plant survival and growth. Below a pH of 5.0 the solubility of iron, aluminum,
manganese, and other elements increases to the point that they may be toxic to
plants. Low pH affects the ability of most plants to grow. Spoils below pH
5.0 usually require liming. The rise in pH will reduce the toxic levels of
elements in solution and neutralize the acid-producing materials in the surface
layer.
Saline and alkali spoils occur in the West when drainage is impeded and surface
evaporation is excessive(2). Various soluble salts, especially calcium, sodium,
and magnesium contribute to spoil salinity. The detrimental effects on plants
is largely due to the toxicity of excessive sodium and hydroxyl ions in non
saline or black alkali soils, whereas the concentration of neutral soluble salts
(mostly chlorides and sulfates of sodium, calcium and magnesium) interfere with
plant growth in saline soils. The latter group of soils usually has a pH below
8.5 because of the influence of the neutral soluble salts, whereas the alkali
soils may have a pH as high as 10.
There are three general ways to handle saline and alkali soils to avoid plant
injury: eradication, conversion,and control(3), Eradication is a method used
to free soil of part of the excess salts. Such methods as underdrainage,
leaching, or flushing and scraping are used. Conversion is the use of gypsum
to change the caustic alkali carbonates into sulfates for leaching from the
surface soil. Control is usually the retardation of evaporation. Soil mulches
are one of the best methods. Frequent, light irrigation is another. Salt-
tolerant crops also are a useful control.
150
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Topographic Factors. Slope.— The length and percent of slope are important
factors in erosion control and vegetative establishment. A general rule-of-
thumb is that as the percent of slope doubles, soil loss increases 2.6 times,
and as the length of slope is doubled, soil loss increases 3.0 times(^). Thus
as the steepness and length of slope increases, the amount of erosion and soil
loss increase, making it difficult to revegetate these areas (i.e., steep and/or
long outslopes, highvalls, and ungraded spoil banks).
Steepness of slope affects all land uses and machinery operation. A 30$ slope
is maximum for farm use such as pasture, hayland or row crops. Precautions
must be taken to control erosion on sloping areas regardless of use. Diver-
sions or terraces that break the slope length and remove runoff to a safe outlet
also help in preventing stream siltation and damage to adjoining lands
(Figure 70).
! ». ' •
Figure 70. Long uninterrupted slope showing erosion after one storm.
151
-------
Aspect.— The direction in which a slope faces is known as aspect. Slopes
facing north and east are generally cool and moist and are not too difficult
to vegetate. Survival and growth on the hotter, drier south- and west-facing
sites is generally poor. GrantC5) found that temperatures averaged about
10 to 12 degrees higher on bare slopes having southern or western exposures
than on slopes with northern or eastern exposures.
Physical properties. Physical properties for the most part present less of a
revegetation problem than do chemical properties. With proper spoil segrega-
tion, placement, and topsoiling, the problem can be minimized. The major
problem will occur on orphan lands where the spoil is a mixture of the entire
overburden and is usually of coarse texture, stony and will not function to
retain water at the surface, as required for a good vegetative cover.
Stoniness.— Stoniness affects all land uses, particularly the operation of
machinery for tree planting, tillage, and management activities. Mine spoil
has been divided into four classes of Stoniness (Table 25) in the Vegetative
Guide for Kentucky(6), in order to evaluate the land use potential and treat-
ment needed to stabilize and vegetate them for future use.
Table 25- MINE SPOILS CLASSIFIED ACCORDING TO STONINESS*
Stoniness class Criteria Tillage potential
1. Nonstony < 0.01$ stone and boulders Can be tilled
2. Stony 0.01-15$ stones and boulders Tillage limited,
can be mowed for
hay, pasture
3. Very stony 15-50$ stones and boulders Treat by hand
k. Extremely stony > 50$ stones and boulders Cannot use equipment
^*
Source: Vegetative guide for Kentucky reference 6.
Texture. — Texture refers to the particle-size distribution of sand, silt, and
clay in spoil; it influences vegetation mainly through its effects on spoil
moisture, aeration, and compaction, Sandy-type spoil has good aeration but poor
moisture holding capacity. Clay-type spoil compacts easily and in some
instances is impervious to water percolation and root penetration. Silty loams
are the best spoil material for revegetation and provide very favorable
moisture conditions.
152
-------
Color,— Spoil material may vary in color from very light to almost black.
Because of these color differences, temperature and spoil moisture may consti-
tute serious problems. Temperatures in excess of 150°F (65.56C) have been
recorded on spoil surfaces composed of dark shales C?). High temperatures are
especially intense on south and west exposures and can be deadly to recently
germinated or young plants.
Nutrients.— Most mine spoils are characterized by a low level or lack of
nitrogen, phosphorous, and organic matter. Nutrients such as potassium or
other trace elements may also be lacking, but not to the relative frequency of
nitrogen and phosphorous (see Spoil Amendments , below).
REVEGETATION PREPLANNING
Before a successful revegetation program can be accomplished, there must be
proper planning. In the development of a surface mine, information is gathered
about the coal seam, overburden, and mining conditions. Detailed studies are
then made, and a tentative mining plan prepared. At this point, design
criteria for reclaiming the mined land should be preconceived and become a part
of the daily operational plan. The two plans must be compatible, but
reclamation should not have a lower priority than the mining plan. Reclamation
should be planned even to the extent that it controls the mining methods and
equipment to be used to do the total job.
The key to a successful reclamation program begins with the basic knowledge of
the physical and chemical characteristics of the mineral seam and overburden,
which is obtained by core drilling or prospecting with a bulldozer. The bore
hole data help to determine the proper handling, deposition, and segregation
of the various strata in the spoil profile so that undesirable material is
buried under clean fill and top soil is returned to the surface as a medium
for vegetation (see preplanning section).
In as much as preplanning is based on predictions, adjustments in the mining
and reclamation plans may have to be made as the operation progresses.
Seeding time. Until recently it was thought that the only time to seed and
plant was in the spring. This meant that graded spoils would not be seeded for
several months, losing the advantage of having a loose seedbed. These bare
spoils, after a few rains, would become crusted and hard making it very-
difficult to establish an effective cover. Erosion patterns such as rills and
gullies will result unless-mechanical measure, were used to control runoff.
However, graded spoil in some locations can be planted in the fall if certain
precautions are taken. Perennial grasses often are better in a fall seeding,
and legumes in the spring. Many failures are almost assured if species are
planted out of season. The U.S. Forest Service(T), has found that cover can
be established during mid-to-late-summer by the use of annuals such as pearl
millet, sudan X sorghum hybrids, Dorean and Kobe Lespedezas (legumes). These
annuals provide only temporary cover, therefore, permanent cover perennial
species must be sown either with the annuals or in a separate seeding the
following fall or spring. Fall seeding is now commonplace and with the develop-
nient of guidelines for the use of various summer annuals and perennials, quick
cover can also be obtained in the summer.
153
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Grading and Backfilling as it Affects Revegetation. Reclamation should follow
closely behind the mining operation. The bare spoil and pit should be reclaim-
ed as fast as possible, because the freshly moved material is easier to grade,
handle and plant than older compacted material. In addition, bare spoils
and pits are more susceptible to acid formation and erosion. Backfilling and
grading should be kept current with the operation.
Many state laws and pending Federal legislation have current grading require-
ments. A typical example is found in the Kentucky regulation and is included
in Appendix G. The regulation is presented as an example and is for general
interest only.
Revegetation should follow the grading as soon as possible in order to establish
a quick protective plant cover on the barren spoil. Grasses and legumes should
be planted on all areas.
Trees may be planted in combination with grasses, but not alone, as they require
excessive periods of time to be effective for erosion control. Soil samples
should be taken to determine the limestone and fertilizer requirements. Where
possible, the ground must be loosened the fertilizer and limestone worked in,
and the grass seed planted. On steep slopes, blowers, hydraulic seeders, air-
planes, and helicopters can be used to seed the area. A mulch may also have to
be used. The type of grasses, legumes, and trees to be planted will depend on
local conditions and long term use of the land.
Most enforcement agencies have the power to approve alternate plans of
restoration, i.e., water impoundments in the final cut. High quality water
impoundments are usually encouraged and such factors as the pH, temperature,
dissolved oxygen, and mineral salts are considered in the determination of the
water quality. Major uses include water supply for domestic purposes, live-
stock, wildlife, fire protection, recreation, and irrigation. In some cases,
a surface mining operation can provide a suitable site for developing a
sanitary landfill. Under all circumstances, a water impoundment or sanitary
landfill must be planned and constructed according to established standards.
Compaction problems that could result from extensive grading, spoil segrega-
tion during mining, spoil placement, topsoiling, effects of surface configura-
tion in water control, and complete grading as it effects revegetation efforts
are discussed in detail in following sub-sections.
The question of how much grading and backfilling should be performed on strip-
mined lands is very controversial. Although many of the problems are similar
for contour and area mining, there are major differences. They are discussed
separately below.
Contour Mining.— Highwall's are the dominant physical feature of contour
mining on steep slopes. They represent less than 15$ of the total horizontal
disturbed areavS). After many years of weathering, some highwalls will be
reduced and covered with volumteer vegetation. However, in most cases, these
scars will be there for many generations. They do not blend in with adjacent
land and are considered by some people to be an aesthetic blight.
-------
For many years "backfilling was accomplished by simply pushing dirt into the pit,
as shown in Figure 71 and 72. This technique proved to be unacceptable because
of erosion and mine drainage problems, etc. Three types of backfills were
then developed for contour strip mine benches: contour, pasture, and Georgia V
ditch or swallow-tail. These basic types can be used singly, in combination,
or modified to meet local conditions.
NO DIVERSION
DITCH
SCALPING NOT REQUIRED
TOXIC MATERIAL,
BRUSH & TREES IN SPOIL
BACKFILLED GROUND
SLOPE -
OUTSLOPE
Figure 71. Diagram of common backfilling practice (cover the pit).
155
-------
Figure 72. Common "backfilling practice (cover the pit).
For contour "backfill, the edge of the highwall is "knocked off", and the spoil
is graded back toward the highwall to approximate the original contour
(Figure 73 and 7^ ). This method is the closest approach to returning the area
to its original topography and produces the most pleasing aesthetic effect.
Contour backfills are preferred wherever possible. However, because it cost
more than other types of backfilling, it is practiced only in states that have
laws requiring its use. Long steep slopes that are subject to erosion can be
formed if proper controls are not taken. The erosion problem can be solved by
156
-------
DIVERSION
DITCH
-SCALPED AREA-
BACKFILLED GROUND SLOPE
TERRACE LONG SLOPES
FILL
BLOSSOM
Figure 73. Diagram of typical contour backfill.
completing final grading across the slope and/or by the construction of a
diversion ditch at the top of the slope and a series of terraces, diversions,
or ridges across the slope. Each of these drainage control measures should
have a constructed discharge outlet. Rapid vegetation with grasses and legumes
is critical for this type of backfill. 3y grading to the approximate original
slope and reducing all highwalls, pollution attributable to exposed highwalls
would be eliminated. Some of the major problems associated with exposed
highwalls have been defined as follows:
157
-------
Figure 7*4-. Typical contour backfill.
1. The area poses a safety hazard to people and animals
2. Areas of land above highwalls are inaccessible
3. Weathering causes sloughing that blocks drain ways
k. The area is amenable to fewer uses than before mining
5. Social and economic impacts are greater
6. Salts are dissolved by rainfall from the exposed highwall and are
then carried by runoff water, as pollutants, into tributaries.
158
-------
When the highwall is reduced and covered, approximately 30%. additional area
above the highwall is disturbed in order to obtain the necessary fill material,
unless the block cut method of mining is used (see Section IV, Surface Mining
Methods, Techniques and Equipment). A modification of the contour backfill
is the terrace backfill (Figure 75). The highwall is reduced and a terrace is
formed. Precautions must be taken to control the velocity of surface runoff
or excessive erosion may result.
Pasture backfilling calls for the grading of the spoil to cover the pit and any
acid producing strata, but not the entire highwall (Figures 76 and77 ).
DIVERSION
SCALPED AREA-
SLOPE AWAY FROM HIGHWALL
LESS THAN 5°
35° MAXIMUM
TOE
OF
FILL
Figure 75. Diagram of typical terrace backfill.
159
-------
DIVERSION
BLOSSOM
BENCH
Figure ?6. Diagram of typical pasture backfill
(reduce highwall, if fractured).
The slope of the graded spoil should be away from the highwall, and the slope of
the "outslope" should be reduced to control the water running off the bench.
Diversion ditches must be constructed along the top of the highwall to reduce
the water entering the pit. Long slopes should be interrupted with terraces to
control runoff and reduce erosion. This type of backfill is used to eliminate
percolation of surface runoff water in areas that have been underground mined
and/or augered.
160
-------
..>*
mt «A- -**
-
- .- • • .-.- • -~-- -
'• "• .-^.#«K?-:
-*..-«HS£i- '.^-TtMb
^ ..
j£fe-T7 • -^i" ,-;. = 7v?* *rr*'*«rt'^
tfcSSS?
Figure 77- Typical pasture backfill (reduce highwall, if fractured)
Several States require that the slope of the graded spoil must be toward the
highwall. A Georgia V ditch or swallow-tail backfill has proven to be the most
satisfactory method (Figure 78 ). The drainage ditch is constructed on the
solid bench parallel to the highwall and of sufficient distance from the high-
wall to assure that any material falling off it will not obstruct the drainage-
way. The ditch should be laid on a nonerosive grade, and in some cases it must
be lined to prevent excessive erosion of the channel. The ditch should carry
the runoff to a properly designed discharge structure.
161
-------
SCALPED AREA-
BACKFILLED GROUND SLOPE
\
Figure 78. Diagram of typical Georgia V ditch (swallow-tail) backfill,
(reduce highwall, if fractured).
TOE
OF
FILL
If highwalls are not reduced and the benches are properly reclaimed, they can
provide land conducive for:
1. Pasture development
2. Access roads or trails that can be used as:
a* Forest-fire breaks
b. Entrance to remote areas for forest fire control crews
c. Logging activities
d. Recreation such as horseback riding, hiking, camping, hunting
and fishing
162
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3. Openings for wildlife (including food, cover and water)
h. Housing and industrial sites.
Area Mining.— On lands where the method of operation does not produce a bench
(area strip mining), complete backfilling and grading to the approximate
original contour is generally required. The question - should lands disturbed
by area type mining be completely graded or left in a ungraded condition - is
no longer a major issue. The public is now demanding that the disturbed land
be put back in as nearly its original condition as possible. This feeling is
reflected in the type laws that are being passed, or under consideration for
control of surface mining. Backfilling and grading to the approximate
original has been interpreted to mean that lands are considered to be completely
backfilled and graded when the contour of the land conforms approximately to the
contour of the original ground. However, the final surface of the restored area
need not necessarily have the exact elevations of the original ground surface.
A flat surface or a surface with less slope than the original ground surface is
also considered to comply with backfilling and grading to the "approximate
original contour" requirement (Figure 79 and 80 ).
Some of the points stressed for spoil segregation, placement, top-soiling, and
complete grading are:
1. Land can be made productive more easily and quickly by being able to
use conventional farm implements and mechanical reclamation equip-
ment for restoration purposes.
2. Toxic and undesirable materials are buried and should not cause
future pollution problems.
3. Light-colored materials can be put on the surface to help decrease
spoil temperatures and evaporation. However, the dark colored A
horizons are generally preferred when available.
k. Topsoiling provides proper techniques to assure rapid establishment
and growth of suitable vegetation that plays a significant role in
erosion control.
5. Compaction can be controlled by large discs, subsoilers or rippers
that will break up the surface for seed bed preparation, provide a
rooting zone, and permit the penetration of moisture.
6. Management of the graded areas is easier, cheaper, and more profit-
able. Grant(5) has found that grading has several beneficial
effects: "A better seed bed can be prepared, less seed is required
per acre, thicker stands have been obtained, weeds can be controlled
more easily, and excess forage material can be harvested as hay.
163
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Figure 79. Strike-off grading: First generation of grading
(area strip mining).
7. Grading is easier and cheaper because the rock present in the over-
burden is buried and covered by segregation of materials during
mining.
8. Grading to the approximate original slope is more pleasing to the
eye, and almost any vegetation, properly selected and planted, will
take care of the aesthetic problem.
9. No one can predict, with any degree of certainty, the land use
requirements of future generations. However, if the disturbed area
is graded back to the approximate original slope, with adequate
safeguards to control run-off and erosion, it will be available when
needed without additional treatment.
16U
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Figure 80. Backfilling and grading to the approximate original contour
(area strip mining).
Mechanical Spoil Manipulation. Basically, spoil manipulation is the grading
and shaping of the mined area to produce as many flat surfaces with short slopes
as possible, and at the same time to leave the spoil surface in a rough or
furrowed condition on the contour. The resulting topography will increase
rainfall retention infiltration and percolation, increase leaching of spoil
salts, and reduce runoff and erosion. By increasing the infiltration rate,
spoil moisture for vegetation is available during dry periods. Smooth, com-
pacted surfaces with long slopes should "be avoided, as they contribute to
excessive runoff, severe erosion, and sedimentation; very often, the seed and
fertilizer is washed off.
Terraces can effectively control runoff, erosion, and sedimentation and con-
serve moisture for vegetation. Curtis(9), using a Rome bedding harrow to
mechanically form terraces on a strip mine bench in Breathitt County, Kentucky,
found that the peak flows on a terraced plot averaged 65% less than on the
165
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control plot, sediment yield averaged 52% less, and total runoff averaged
less. A visual comparison indicated much "better vegetative cover on the
terrace plots. This was attributed primarily to effective seed bed preparation
during terrace formation and increased moisture retention.
Used in conjunction with the Rome bedding harrow and with ridges 8 feet (2. if 3
meters) apart, a medium-sized dozer can cover about U acres (1.6* hectares) per
hour. Terracing costs were estimated to be $10 per acre (.UO hectares) or less.
Curtis advises that terraces be designed and used to withstand the numerous
storms of varying intensities that can be expected to occur during the first
year, when the earth is bare, as well as into the second year, when vegetation
is struggling to gain hold.
Water-retarding basins have been used with varying degrees of success on strip-
mine benches. These basins are shallow depressions made by a bulldozer or
highlift to trap or slow down runoff water on the bench. Silt is deposited in
the basin and is thusly prevented from reaching receiving streams. Trapped
water evaporates and infiltrates into the spoil providing moisture for plant
growth. Location of these basins is very important, as they could cause AMD
problems if they are constructed on the high side of the coal seam and water
percolates into underground mines.
Furrow grading is the result of successive parallel passes by a bulldozer, with
spoil spilling from the end of the angled blade. The furrows, are generally on
the contour and range from 2 to 3 feet (.60 to -.91 meters) in height and are
3 to U feet (.91 to 1.21 meters) between peaks.
Furrow-graded and conventional smooth-graded spoils were comparatively studied
for a 10 year period (1962 - 1972) by Riley(lO). Objectives of the research
were to determine:
•
1. The nature of chemical changes occurring to furrow-graded spoil
materials.
2. The effect of increased rainfall retention on leaching of soluble
salts, sulfates, and certain metals from the spoil surface.
3. The survival and growth of selected plant species as an indicator
of site improvement.
The data clearly reflect the beneficial effect of an increased rate of leaching
of chemical components of spoil materials as the result of increased rainfall
retention and infiltration on the furrowed spoil surface. As a result of in-
creased leaching of soluble salts, sulfates, and other chemicals inimical to
plants, site improvement was reflected by better plant survival, growth, and
reproduction.
Three mechanical spoil manipulation treatments were implemented by Sindelar
et al.(2) in a semiarid region of Montana. Each of the mechanical treatments
was designed to retard surface flow and simultaneously increase infiltration
into the spoils. In addition, the treatments should result in an improved
seedbed for broadcast seeding.
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The three treatments are as follows:
1. Gouging. Gouging is a surface configuration composed of many
depressions and is accomplished with a specially constructed machine
that has hydraulically operated, 25-inch (63.5 centimeter) diameter
disc scoops that alternately raise and lower while being drawn by a
tractor. The three disc scoops create elongated basins on the contour
approximately lU to l6 inches (35.5 to kO.6 centimeters) wide, 3 to U
feet (.91 to 1.21 meters) long and 6 to 8 inches (15.2 to 20.3 centi-
meters) deep. This pattern is amenable to gradual slopes and flat
areas. It creates a cloddy seedbed ideal for broadcast seeding
(Figure 8l).
2. Dozer Basins. Dozer basins are large depressions designed to accom-
plish what terracing is intended to do, but without the characteristic
precision, hazards, and expense. Dozer basins are 15 to 20 feet
(^.56 to 6.08 meters) long and are formed by dropping the bulldozer
blade at an angle at intervals and bulldozing on the contour. The
resulting basins are approximately 20 to 25 feet (6.08 to 7-6 meters)
from center to center and are about 3 to k feet (.91 to 1.21 meters)
in depth. Basins are constructed in parallel rows with about 20 feet
(6.08 meters) between rows. Precipitation intercepted within each
mine drainage accumulates in the basin bottom in quantities sufficient
to thoroughly saturate the basin limits. The increased soil moisture
availability assures the establishment of a nucleus stand of vegeta-
tion the first growing season; from this nucleus,it can spread between
basins to make a complete cover.
Figure 8l. Gouging to retard surface runoff and increase
infiltration into the spoil.
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3. Deep Chiseling, Deep chiseling is a surface treatment that lopsens
compacted spoils for a depth of 6 to 8 inches (15.2^ to 20,32 centi-
meters ). The process creates a series of parallel slots on the
contour to effectively impede water flow and increase the infiltration
rate. Deep chiseling use a modified Graham-Hoeme plow with 12
chisels to form a rough cloddy seedbed. This treatment is effective
on relatively flat slopes and is very beneficial in loosening spoil
before gouging or following dozer basin construction.
Performance of each treatment was evaluated and results indicated that gouging
stored more water in the upper k feet (1.21 meters) of spoil, greatly reduced
moisture stress days, and had better plant survival than chiseling or dozer
basins. Erosion damage appeared greater on chiseled plots.
Top soiling. Topsoil is the unconsolidated mineral matter naturally present
on the surface of the earth that has been subjected to and influenced by genetic
and environmental factors of parent material, climate, macro- and microorganisms,
and topography, all acting over a period of time and is beneficial for the
growth and regeneration of vegetation on the earth's surface.
Several States require topsoiling as part of their strip mine reclamation
program. Topsoiling is the process of removing a separate, developed layer of
desirable soil material from areas to be mined and keeping it in such a condi-
tion that it will not deteriorate until it is returned, as the top layer, after
the operation has been backfilled and graded (Figure 82).
Of all the natural resources that support life, soil is possibly the most
important. A mature soil system takes thousands of years to develop and is as
complex and integrated as the plant community that develops on it. Life in the
soil depends on having a good supply of organic matter readily available.
Organic matter is the main supporter of soil microorganisms, which are necessary
for soil development.
Despite the rejuvenating ability of soil and its potential as a growth media,
operators have shown a remarkable reluctance to practicing overburden segrega-
tion during mining and returning the topsoil as the final act of backfilling.
Cost has been given as the reason. In most cases, the additional costs are
insignificant when one considers the cost of additional lime and fertilizer for
making subsoil suitable to plant establishment, replanting bare areas, and
continual maintenance of revegetated areas.
The United States Department of Agriculture, Agricultural Research Service,
Mandan, North Dakota report that the topsoil is very important in the surface
mining reclamation process. Their research at Mandan and elsewhere has shown
that in most instances revegetation is doomed to failure if this productive
part of the profile is not conserved and replaced in sufficient quantity on the
surface as the medium for revegetating the land. The underlying materials are
sterile. They often contain excess salts and toxic elements (heavy metals,
etc.). They are massive in structure and will not take water. The difficulties
and costs of revegetation are increased several orders of magnitude if these
underlying materials end up on the surface.
168
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Figure 82. Removing topsoil before stripping.
The directors of reclamation for the States of West Virginia and Pennsylvania
attribute the success of their restoration program mainly to the topsoiling
technqiues that are required and being practiced on all operations(ll,12).
During mining, when strata in the overburden are found to be toxic or limiting
to plant growth, they must be effectively isolated from the root zone in the
established spoil profile. If topsoil is placed directly on toxic overburden,
the topsoil may become polluted by upward movement of harmful salts. There
must be a layer of clean fill between the root zone and the underlying toxic or
undesirable materials so that plant establishment and growth will not be
impeded.
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On all slopes that will be covered with topsoil, it is essential that the
topsoil be firmly bonded to the existing spoi-1 surface to prevent slippage down
slope. This bonding can be increased by scarification of the slope before
topsoiling^S).
In area mining, topsoiling has been accomplished with draglines, bucket-wheel
excavators and scrapers. The topsoil is usually placed on top of the adjacent
cut spoil during the mining operation to prevent rehandling. In contour mining,
the topsoil is often stockpiled and replaced after grading (except in block
cut mining, where topsoil is removed and placed on graded areas in one operatr-
tion). Topsoil can only be stockpiled for a limited time or it will lose its
ability to enhance vegetative growth. Topsoil should be saved, even if there is
only limited amounts available.
Mulches. Various mulches such as straw, hay, wood chips, and shredded bark
have been used successfully as aides in establishing vegetation on graded,
surface-mined spoils. They provide insulation against intense solar energy thus
lowering ground temperatures. Evaporation rates are reduced, thereby minimizing
the accumulation of toxic salts on the surface. A more favorable moisture
supply is assured in the growth media. Mulches also break down after ground
cover establishment, supplying valuable organic matter to the soil, which in
turn promotes microorganism buildup. On steep slopes and highly erodable
material, mulches will reduce raindrop impact, help control erosion,impede the
flow of run-off water, and hold seed in place.
Straw and hay mulch can be applied by hand on small plots and by mulch-blowing
equipment on larger areas. It is applied at rates of 1.0 to 2.0 tons (0.9 to
1.8 metric tons)per acre (hectare). Straw and hay mulch should be tacked to insure
against excessive losses by wind and water. Liquid and emulsified asphalt are
the most commonly used mulch tack. However, anchoring of straw and hay mulch
by mechanical equipment is used quite extensively. A mulch-anchoring tool is
composed of a series of notched discs that punch the mulch into the spoil. This
method not only anchors the mulch, but it also incorporates organic matter into
the spoil and increases infiltration rates. The spoil should be loose to permit
disc penetration to a depth of 2 to 3 inches (5 to 1.6 centimeters) and should
be used on the contour for erosion control (^-3).
Other methods of anchoring that are simple and have been proven to be effective
are:
1. Pushing the straw or hay into the ground with a shovel at
approximately 12-inch (30.5 centimeters) intervals.
2. Placing shovelsful of earth on top of the mulch at about
2U-inch (6l centimeters) spacings.
Wood chips are produced by processing tree trunks, limbs, branches, etc., in
woodchipping machines. As a mulching product on newly seeded areas, wood chips
may be applied by hand on small plots and by mulch blowing machines on larger
areas. Application rates of 60 to 100 cubic yards (1*5.8U to 76.h cubic meters)
170
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per acre (hectare) axe recommendedU-3), Mulching with, wood chips has
proven successful when used with late fall seeding that require protection
over winter.
Wood chips use nitrogen in their decaying processes, and as a result, 20
pounds (9 kilograms) of nitrogen per ton (.9 metric ton) of wood chips should
be added to the spoil CUO. This nitrogen is in addition to that required for
spoil fertilization.
Normally, vegetation on areas to be mined is removed and burned, or covered
with spoil. This is a waste of a natural resource that can be recycled back to
the soil as a wood chip mulch for plant establishment and a source of organic
matter when it decays.
Shredded bark can be used in much the same way as wood chips, but bark does not
require nitrogen in its decaying processes because of the absence of cellulose.
Other than this difference, it is similar in its properties to wood chips.
Small grains and annuals will provide quick, temporary stabilization until
permanent cover is established, produce food and cover for wildlife, add organic
matter to the soil in the form of roots, and leave considerable surface mulch.
In the past, the use of mulches, small grains, and annuals as spoil amendments
has been largely ignored. However, many States now recognize their importance
and are requiring that they be used in the revegetation phase for reclaiming
strip mined lands.
SPOIL AMENDMENTS
If the surface mining operation has been properly preplanned and reclamation
procedures incoporated into the mining method before disturbance, then acid
conditions that will effect revegetation should not be a major problem. The
goal is to prevent acid conditions from developing, rather than to correct the
problem' after it has been created. Acidity of the spoil material is one of the
most important factors limiting establishment and growth of plants on many strip
mine areas.
Limestone. Neutralization with agricultural grade limestone is the most
common method of treating acid spoils, Liming, by increasing the pH to a
minimum of 5.5, will also eliminate toxic concentrations or iron, aluminum,
manganese, and other elements in solution. At the pH level of 5.5 and above,
the biological reactions that form surface mine acid are inhibited. The
agricultural grade limestone should contain sufficient calcium and magnesium to
be equivalent to not less than 80% calcium carbonate. Lime should be applied
and worked into the apoil as far in advance of the seeding as possible. This
will allow time for it to react with the spoil and to be deep enough to be
available for plant use. The amount of lime required per acre (hectare) is
generally not excessive. However, over a period of time, additional lime may
have to be applied so as to maintain a good plant growth. Lime requirements are
based on the results of soil tests for acidity rather than on pH(l5 and 16).
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Grube et al.^) has developed techniques for determining lime requirements for
strip mine spoils, Methods used by most soil testing laboratories are not
suitable for mine spoils. The operator can receive guidance from the local
soil and water conservation district, the county agent, or the university
extension service.
Fertilizer. Soil analyses of spoil banks generally show an insufficient supply
of nutrients for plant establishment and growth. Nitrogen and phosphorus are
the nutrients most commonly deficient.
Davis (7) reports that plant establishment and subsequent growth on spoil banks
in eastern Kentucky is enhanced by fertilizer applications. In no cases were
fertilizer applications detrimental to plants. Nitrogen is nearly always low
in spoil materials. Often, however, there is no response to nitrogen applica-
tions until phosphorus is also applied. Supplementing phosphorus with nitrogen
usually produces an additional growth response on most spoils . Though the
rates of fertilizer to apply will vary from spoil to spoil, fertilizer applica-
tion of nitrogen and phosphorus are recommended for all spoil banks. Fifty-six
kilograms of phosphate (Pp^5 ) Per hectare (50 pounds per acre) and one hundred-
twelve kilograms per hectare (100 pounds per acre) of nitrogen (ammonium
nitrate) applied at the time of seeding are usually helpful in establishing
initial plant cover.
Hodder\2) reports on the necessity of fertilizing Montana mine spoils with
both nitrogen and phosphorus . The absence of either nutrient limited production
in spite of the concentration of the other nutrient. The optimum rate of
fertilization for winter wheat at this site is a combination of 8U kilograms of
available nitrogen per hectare (75 pounds per acre) and 112 kilograms of avail-.
able phosphorus per hectare (100 pounds per acre). Higher rates of fertilizer
did not produce significantly greater plant response. Bengtson et al. '' re-
port that results of studying 1-year-old loblolly pine seedlings on strip-mine
spoil in northeastern Alabama show that fertilization is necessary to get
maximum survival per acre (hectare) with maximum height growth. They also found
that both phosphorus and nitrogen were insufficient to support vigorous growth
of the planted pine. Applications of phosphorus alone stimulated tree growth
somewhat, but maximum growth was attained with application of both nitrogen
and phosphorus at 112 kilograms of each element per hectare (100 pounds per
acre). For fertilizing strip mines, Kentucky requires a minimum of 68 kilograms
of available nitrogen per hectare (60 pounds per acre ) and 112 kilograms of
phosphate (P20r) per hectare (100 pounds per acre
Despite the fact that fertilizer application of nitrogen and phosphorus have
proven to be necessary for the establishment and growth of plants on spoil
banks, this practice is still meeting resistance in some areas, Bennett (l8)
states that if the fertility and management needs of a particular species are
met, almost any grass species can be grown on strip-mined areas.
Normally, the fertilizer should be applied at the same time seeding is done, or
within a few days following seeding. One exception would be during the dormant
season (winter),- where a seeding is made with the intention that the seed will
not germinate until spring. In such a case it would then be better to wait
and apply the fertilizer at about the time the seed is expected to germinate.
ITS
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If the fertilizer is mixed with seed in a hydro-seeder, the mixture should not
be allowed to sit for more than a few hours, for it is possible that the salt
solution formed from water and fertilizer could damage the seeds, especially
grass seed.
Another problem that could result from mixing fertilizer and seed in a hydro-
seeder is a reduction in the effectiveness of the inoculating bacteria for
legumes. Inoculation of legume seed increases their chance of success by
insuring the presence of needed nitrogen-fixing bacteria. The spoil found on
most contour mines lacks sufficient bacteria to naturally supply legumes, there-
fore, seeds must be coated with the bacteria cultures. If the pH of the
fertilizer slurry is below 5.0, most of the inoculation bacteria will be killed
within 30 minutes. If the pH is above 5.0, about 25% of the bacteria will still
be viable after about 2 hours. Therefore, the slurry should be kept at pH above
5.0 and spread as soon as possible after mixing.
Fertilizer can be applied dry with cyclone spreaders, aircraft, and lime-
spreading trucks. It is also possible to dry-mix seed with fertilizer and
spread both together. However, some separation of seed from fertilizer could
result if the mix were hauled for a long distance over rough roads. If the seed
and fertilizer are dry-mixed together, the fertilizer should not be allowed to
get damp. The high concentration of salts going into solution could quickly
damage the seed(lU).
Fly Ash. Fly ash is a powdery residue product when coal is pulverized and
burned in boilers for electricity generation. Most fly ashes are mildly to
moderately alkaline so that fly ash can substitute for limestone in strip mine
spoils neutralization. Lignite ashes are characterized by a Ca-Mg content and
are relatively high in neutralizating power,i.e., 5 tons (U.53 metric tons) of
lignite fly ash are equivalent to 1 ton (.907 metric tons) of CaCOo, while the
neutralizating power of bituminous coal fly ash ranged from 15 to 200 tons
(13.6 to l8l.!+ metric tons) of ash equivalent to 1 ton (.907 metric tons) of
CaC03. Thus, more fly ash is required to perform the same neutralization level
as limestone and the surface mine operator, if he is to assume the full cost
burden, will choose ash only if it is competitive or he requires it for its
other properties.
Mixing large quantities of fly ash with spoil also effects physical changes
that enhance plant survival and growth. The decreased bulk density of the mix-
ture increases the pore volume, the moisture availability, and the air capacity,
thus improving conditions for root penetration and growth(19).
Where vegetation may be difficult to establish on some surface mine spoils be-
cause of nutrient deficiencies, unfavorable moisture regimes, acidity, excessive
salts, toxic substances, and poor physical condition, the application of fly
ash as an ameliorating material to modify or correct these factors offers an
attractive opportunity to improve the spoil and establish a good cover(20).
There is further potential for utilizing fly ash in reclamation by employing the
back-haul concept wherein trucks that haul coal to the powerplant deliver fly
ash to the surface mine area on the return trip. In many cases fly ash can be
obtained for a nominal loading charge and the cost of transportation from the
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plant to the site. A mutually "beneficial arrangement between the coal operator
and the power company provides the operator on the one hand with a material that
aids in reclamation and on the other hand gives the power company the opportunity
to usefully dispose of a troublesome waste product. The application of the
haul-back concept to other waste products, such as sewage sludge, cement kiln
dusts, feed lot manure, composts, etc., as well as fly ash, present additional
opportunities for recycling wastes at reduced costs compared to the straight
haul charge.
Results of greenhouse and field studies indicated that application of selected
fly ash samples to soils either completely or partially corrected boron,
molybdenum, phosphorus, potassium and zinc deficiencies in plants(20 and 21).
However, detrimental effects on plant growth including boron toxicity, soluble
salt damage, and nutrient deficiencies due to increases in soil pH, are
possible when higher than optimum amounts of fly ash are appliedTSl).
Experiments by the Central Electricity Generating Board in England on pulverized
fuel ash utilization(22) and its effect on plant growth showed that boron was
the major plant toxin in the ash. Bennett (l8) also found that when quantities
of certain fly ashes (100 to 200 tons per acre - 90.T to l8l.it metric tons) are
used on strip mine spoils severe toxicity symptoms on plants appeared, possibly
from soluble boron. This condition can be overcome by using boron tolerant
plant or the vegetation can be cut and hauled off and the area plowed.
This procedure removes a considerable amount of boron and will improve the
fertility of the ash. Old ash that has been weathered does not have this
problem. In any case, grazing animals should not be given the hay or forage
until it is tested and declared safe to use.
All fly ash is deficient in nitrogen and this element must be supplied by the
use of fertilizer. Nitrogen deficiency can be made up in part by the use of
certain legumes, such as birdsfoot trefoil, sweet clover and crown vetch.
Organic matter in the form of sewage sludge has been used with toxic fly ash and
is of great value in establishing normal soil populations on the treated areas.
Research by the Morgantown Energy Research Center of the United States Bureau of
Mines has proved the technical feasibility of reclaiming acid-surface mine
spoil using fly ash(23). On a site absent of natural vegetation, fly ash was
spread at rates of about 336 metric tons per hectare (150 tons per acre) on
bench and slope. Heavier application of fly ash was placed against the high
wall. Fertilization and seeding was carried out according to the research
plan. Although farm equipment was used for part of the study, the most
efficient spreading and mixing of fly ash and spoil was by large earth moving
machines.
Fly ash analyses show that the powerplant waste contains many of the trace
elements essential for plant growth, hence, the material should be useful as
a fertilizer to correct nutritional deficiencies. Plants require considerable
quantitites of P, K, Ca, Mg, and N, for example, and lesser or even trace
amounts of Mn, Fe, Mo, Cu, Zn, and B. Table 2.6 shows the typical composition of
bituminous coal fly ash received from the Fort Martin, Pa., powerplant. This
fly ash was used at the Stewartstown, W.Va., study sited9).
-------
Table 26, TYPICAL COMPOSITION OF BITUMINOUS COAL
CFORT MARTIN) FLY ASH. USED AT STEKARTSTOWN STUDY SITE*
Item % by weight Item
Major elements:
Si02
ALgO-
Fe20^
CaO 3
MgO
Na20
KoO
1*6.8
23.3
17,5
5-7
l.l
.8
2.0
Trace elements:
B
Cu
Mn
Mo
Zn
Bulk density, e/cc
**M
U50
1*0
200
20
90
1.15
Ti02 .7
P?°5 -5 pH 11.9
C 1.5
S .1* Fineness, (% through 200 mesh) 91
Loss of ignition 5.1 Average size, micron 19
Source: Reference 19 at the end of this section
Cost with fly ash depends on several variables, including the terrain, soil type
and age, acreage, equipment used, legislative requirements, and degree of re-
clamation. Based on experience to date at 65-acre test site (Stewartstown), the
cost of vegetating areas devoid of growth with grasses is estimated at about
$300 per acre ($7^1 per hectare) Table 27 summarizes the pertinent costs.
Fly ash application rates for use in the field were determined empirically in
the laboratory by measuring the pH of equilibrated soil-water mixtures on a 1:1
by weight basis. A "rule of thumb" for fly ash application is that 1-inch
(2.5!* centimeters) cover of ash equals 100 tons (90-7 metric tons) per acre
(l cm = 88.2 metric tons per hectare)(2*0.
In the U.S. Bureau of Mines studies(23) the fly ash treatment has been effective
in increasing pH, enhancing water holding capacity, and improving soil texture.
The grass and hay yields produced on fly ash treated spoils were comparable to
average values for West Virginia. Rye grass, red top grass, orchard grass,
Kentucky 31 fescue, and birdsfoot trefoil showed good promise.
Strip mine spoils have been shown to be not only suitable disposal areas for
large quantities of fly ash sewage sludge, compost, etc., but in addition,
applications of these and other wastes can create suitable sites for future
agricultural, forestry and recreational enterprises.
Sewage Sludge. Sewage sludge is another waste product that is being recycled
on strip mine areas to supply nutrients for establishment and growth of plant
cover,
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Table 27, RECLAMATION COST OF SURFACE-MINED SPOIL
CSTEWARTSTOW)*
Item
Fly ash (a)
Spreading and ripping Cb)
Fertilizer (c)
Seed^)
Fertilizing and seeding
Soil testing
Total
Cost
per acre
$15^.50
120.00
20.70
10.95
12.75
10.00
$328.90
Cost
per hectare
$381.62
296.^0
51.12
27. OU
31. U9
2*).. 70
$812 . 37
Percent of total
kl
37
6
3
U
3
100
Land acquisition, leveling, and supervision, are not included.
'a'150 tons fly ash per acre at delivered cost (8.5 miles from power station)
of $1.03 per ton. (Fly ash provided at no cost.)
V°'Eight hours of machine time per acre at $15 per hour.
'c'Six hundred pounds of l6-l6-l6 per acre.
Thirty-three pounds of seed mixture per acre.
Source: Reference 19 at the end of this section.
Metric Units: mile = 1.609 kilometers; ton = 0.907 metric tons;
acre = O.^OU hectares; pound = 0.^53 kilograms
Sewage sludge is a dark grey liquid containing 2% to 5% solids as finely
divided and dispersed particles. Its physical and chemical properties vary
according to the composition and treatment of the sewage and the processes used
to treat the sludge. It includes all or part of the solids removed in primary,
secondary, and tertiary treatment of sewage.
There are several methods of stabilizing sludge. One of the most popular
methods is to treat sludge in 15-day, heated anaerobic digesters to stabilize
the solids, thus eliminating obnoxious odors and fly problems after application
on land. The pathogenic contamination hazard of digested sludge can be reduced
to nil by lagooning the material for 30 days before land application(25).
Investigations conducted by Dick et al.C26)j Department of Civil Engineering,
University of Illinois, show the average percentage die-off of fecal coliforms
in digested sludge after 30 days to be 99,9 percent.
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Since the flow properties of freshly digested sludge vary little from water,
it is easily transferred "by pipes, using ordinary pumping techniques and equip-
ment.
Several methods for applying sludge have been developed:
1. Furrow irrigation on properly contoured and contained areas.
2. Sprinkler irrigation on irregular, temporary, or non-engineered
sites.
3. Flooding an entire area that is self-contained or surrounded by
dikes.
I*. Placing liquid sludge beneath the soil surface.
Liquid digested sludge contains nitrogen, phosphorus, and potassium. Two inches
of liquid digested sludge applied intermittently throughout the year would
satisfy the average corn crop requirements of l68 kilograms of nitrogen per
hectare (150 pounds per acre), 1*5 kilograms of phosphorus per hectare (^0 pounds
per acre), and 90 kilograms of potassium per hectare (80 pounds per acre) (27).
Digested sludge contains additional growth-promoting ingredients. Being a
natural organic material, it imparts the same favorable characteristics to soils
that are normally attributed to its natural humus content. Sludge increases
soil fertility, improves soil structure, increases water-holding capacity, and
controls moisture supply. It contains vitamins and trace elements essential to
growth: sodium, boron, calcium, magnesium, manganese, iron, aluminum, sulfur,
copper, zinc, molybdenum, chloride and silicon. Table 28 presents a typical
analysis of a lagooned, digested sludge from the Greater Chicago Metropolitan
Sanitary District (28).
The U.S. Forest Service has recently completed the field evaluation of test
plots treated with liquid sludge and planted with grasses.
These tests were conducted on the Shawnee National Forest in southern Illinois
on orphan strip mine spoils (Palzo Project). The spoils were very acid (pH 2.^5)
and had virtually no vegetation since mining ceased in 196l(29).
Their conclusions were that sludge produced a vigorous growth of grasses and
improved the subsurface drainage water quality. The test plot results indicated
that a minimum-maximum limit of 200 to 250 dry tons (l8l.lt to 226.75 metric tons)
of sludge per acre should be applied. One inch (2.5^ centimeters) of liquid
sludge per week was the best rate to apply. At regular intervals during
application, accumulated solids should be incorporated by disc into the first
9" - 12" of soil. Discing on the contour will help increase infiltration rates,
provide protection against erosion and minimize odor problems should they occur.
Rest periods should be provided between applications to help dry the soil.
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Table 28, ANALYSIS OF LAGOONED DIGESTED
SLUDGE FROM THE METROPOLITAN DISTRICT
OF GREATER CHICAGO*
Constituent
Total N
Total P
K
Ca
Mg
Zn
Fe
Mn
Cd
Cr
Cu
Na
Ni
Pb
Source: Reference 28 at
pH =7.2, EC = 3.9 mmho
Average Concent rat ion
(% dry basis)
2.6
1.2
3.U
0.36
2.1
0.97
0.98
3.U
0.02
. 0.05
0.38
0.22
0.28
0.05
0.08
the end of this section.
per cm
The Rand Development Corporation'^ ', used liquid sludge in 1966 to reclaim
diked plots of extremely acid spoils in the vicinity of Canton, Ohio. The plots
represented spoils with different degrees of acidity from pH 2.3 to near
neutrality. Liquid sludge was applied to plots by flood irrigation and was left
on the surface to dry and form a seed bed for a mixture of grasses and legumes.
The sludge formed cracks as it dried where the seeds germinated and grew,
extending roots into the spoil. The grass and legumes were observed to be
growing vigorously six years later.
Not only can sludge treatment reduce acidity problems of strip mine spoils,
it can also reduce severe alkalinity problems. In 1969 sludge was used to treat
an alkali sand filled lagoon (pH 10.5) near Ottawa, Illinois. One hundred-
seventy dry tons per acre of sludge was incorporated into the sand surface and
planted to rye grass, orchard grass, and brome grass resulted in a dense
vegetative cover.
The sludge application reduced the sodium concentration of the soil which was
the main deterrent to plant growth. The project showed that sludge applications
can reclaim sterile alkaline land in less than one year. This approach could
have application possibilities in the alkaline spoils of the west.
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By using the most up to date reclamation techniques available, complete restora-
tion of the strip mined lands to levels equivalent to those characteristic of
productive soils -will take many years under normal agricultural practices.
Efforts by the most conscientious operators cannot put the humus layer back to
its original position in the soil profile. It will be mixed with other materials
during the mining and reclamation phases and this storehouse of plant nutrients
will not be available for plant use. To replace this soil organic matter,
stabilized sludge is outstanding in its ability to increase the humus content of
soils quickly(25). The results of studies described by Hinesly indicate that
the organic material produced in a 15-day heated anaerobic digestion process has
properties very close to that of natural soil organic matter of humus. Digested
sludge is one of the few materials that can be used to effect a rapid increase
in the humus content of soil. It is the only substance with these properties
that is available in quantities.
Hitrogen contained in digested sludge is usually the first factor to limit rates
of application. Adding excess nitrogen to spoil involves the risk of polluting
ground water with nitrates. Hineslyv3l), indicates that about 2 inches of
liquid digested sludge would satisfy the nitrogen needs of non-leguminous crops
without producing excessive nitrate in percolated water. Higher loading rates
can be made on strip-mined lands because they have much greater assimilative
capacities for plant nutrients and non-essential trace elements than most soil
types.
Many of the trace elements in sludge are essential to plant growth, but nearly
all can be toxic if the concentration is high enough. Hinesly(25), states that
higher applications of sludge can be applied on strip-mine lands without
encountering trace element problems than might be the case when sludge is
applied on soils. In the University of Illinois study, 150 tons of sludge were
s applied per acre over a 5 year period to corn plots without causing toxicity.
Where sludge is to be used for reclamation of surface mines, it will probably
be a short term treatment and the volume used will not reach toxic limits.
Where sludge is to be used in a continuing management program for crop pro-
duction, toxic levels must be considered.
Hinesly(25), reports the outlook in promising for mixing 200 dry tons per acre
of lagooned sludge into the surface foot of cultivated strip-mine spoils during
a four year period without significantly affecting nitrogen content of water
supplies. With such a program the top surface foot of reclaimed spoil bank will
contain a humus content of ^ to 5 percent to a depth of 1 foot within a U year
period.
The cost of removing water from liquid sludge is high enough to cause liquid
sludge handling and application to be preferable for most communities, but for
some, mechanical dewatering may be feasible. Sludge cake or partially dried
sludge can be hauled in rail cars, barges or trucks. Sludge can be then spread
with a manure spreader or a bulldozer. If spraying is a more feasible method of
application and water is available at the reclamation site, re-slurrying the
sludge may be possible and used in hydroseeders. The most economic methods of
transportation and applying sludge depends upon the amount and kind of sludge
facilities available, and other local conditions.
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Thus sewage sludge has several qualities that make it desirable for reclaiming
spoils. It adds not only the nutrients needed to establish vegetation, but
also a stable organic matter that will form a humus in the surface layer or
serve as a mulch. Adding organic matter improved the spoil structure,
waterholding capacity and ion exchange capacity, and creates a more favorable
root zone for grasses and legumes. Sludge buffers extremes in the spoil pH
and immobilizes ions which may be present in toxic concentrations. Although
constraints that limit the rate of sludge applications to agricultural crops
and pasture lands may also limit the amount that can be applied for reclama-
tion, the permissable rate is much higher on strip mines(32). Plants that are
tolerant of relatively high concentrations of metals in spoils are good for
revegetation purposes. The opportunity for controlling percolation and run-off
water to prevent nitrate pollution of ground water is greater than it is in a
regular farming operation. Under drainage, terraces, dikes and catch basins
can be constructed during the shaping of strip-mined areas. Public exposure to
pathogens, which could be present in treated mine spoils, should not be a
problem.
COMPOSTING
Composting is the bio-chemical degradation of organic materials to a humus-like
substance, a process constantly carried on in nature. It is a sanitary process
for treating municipal, agricultural and industrial wastes.
Properly managed windrow or enclosed, high-rate digestion composting will pro-
duce a product safe for agriculture and gardening use. Compost has the remark-
able ability to provide soils with better tilth, water holding capacity,
improved nutrient holding capacity and due to its high organic content is a good
soil conditioner. Present technology of composting will permit the recycling
of organic waste materials back to the soil without significant pollution of
water or land resources(33).
Compost plants are operating successfully in all parts of Europe, some for as
long as Uo years. One use has been as a soil builder for reclamation and
recultivation of lands devastated by strip-mining(3^).
Composting of municipal refuse has received almost no attention in the United
States in spite of the fact that it is being successfully practiced in other
countries. The reason cited most frequently for the lack of interest is that
no market exists for compose. However, the high organic content which makes it
a good soil conditioner could find a market in strip mine reclamation, if it is
competitive with other materials now in use, Compost mixed with sewage sludge
would be an ideal material to use in producing an artificial soil for orphan
spoil bank reclamation and could be most helpful in the west where organic
matter in the original soil is very low. The major drawback could be the high
cost of transportation if it had to be shipped a long distance.
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Four years of tests "by the Tennessee Valley Authority proved the effectiveness
of composted municipal wastes in producing vegetative cover on coal strip mine
sites in Virginia, Examination of organic layer development on the test sites
indicated that to obtain a stabilized organic layer over mine spoil in two years,
application rates between 26 and 71 tons per acre would be required. Fifty tons
per acre left substantial residue and initiated a humus layer after two years
and also resulted in good vegetative coverC35).
MANURE
In a few incidences local farmers have reclaimed surface mined lands using
manure instead of commerdial fertilizers. Manure was applied either directly
or by holding animals on the area. Manure has also been used to build up the
organic material in tailings dams in order to help establish vegetation. Manure
should be considered along with sewage sludge and compost as a material to build
organic matter in spoils.
SPECIES SELECTION
During the early years of strip mining the acreage disturbed was small and land
was plentiful. No thought was given to reclamation or returning the land to some
form of productive use. Strip-mined areas were left in a rugged, irregular,
and harsh condition consisting of hills, valleys and peaks. The very steep
slopes limited future land use to forestry practices. It was not until after
World Wai1 II that surface mining as is known today began to develop. Reclama-
tion began a few years later and consisted mainly of tree planting. Trees were
first selected because some of the species such as pine and locust grew at low
pH and did not require soil amendments in order to survive. Reclamation costs
were exceedingly low, less than $30 per acre (O.^OU hectare). The main objec-
tive was to cover the ugly scars and provide for a potential economic return.
Trees alone do not provide quick stabilization in their early stages of develop-
ment. Excessive runoff and erosion took place until the canopies closed and
afforded protection from direct rainfall impact. Up to 10 years are required
to get crown closure and adequate ground protection to control erosion.
Curtis(9) reports that watershed studies indicate high sediment yields during
and immediately following mining. During this critical period, trees alone are
of little value as ground cover.
Experience has shown that a quick growing, herbaceous cover with tree planting
is indispensible if maximum site protection is to be obtained immediately.
Some species of grasses and legumes are more competitive than others with
trees. In any revegetation program, it should be borne in mind that the object-
ive is to stabilize the area as quickly as possible after it has been disturbed.
Plants that will give a quick, protective cover and enrich the soil should be
given priority. In some instances, these initial plantings should be considered
only as a tool in the land management process of obtaining maximum land use,
and not the end result. Many mixtures of seed and techniques for establishment
are available that will not only not hinder tree growth but give good survival,
and quick stabilization.
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The available knowledge on what species will or will not grow, where they will
grow, what is required to make them grow and their effective use for reclamation
purposes is broadC2,5,6,7,10,13,1^,17, and 18). This is particularly true for
the eastern United ..States; far less is known of the arid and semi-arid western
situations. It is fortunate that many of the plant species that have been
successfully used in revegetation eastern strip mined areas are also desirable
economic crops and accelerate the natural succession of plants.
Legumes are of special value in vegetating strip mine spoil because of the low
nitrogen level in spoils; they should be included in all seed mixtures. When
legumes are properly inoculated, they develope nodules on their roots and are
then able to fix atmospheric nitrogen that can be used by plants. Grasses
especially need nitrogen, which legumes are able to supply without annual treat-
ment of fertilizer. In addition, legumes are taprooted and can incorporate
organic matter deeper than grasses. Grasses are fibrous rooted and bind the
soil together better than legumes, especially in the critical years following
germination. Both should be included in all seed mixtures in order to secure
the benefits offered by each species(7).
Over a long period of time additional lime and fertilizer may be required to
maintain good growth of grasses and legumes. This is no different from what
would be expected on any agricultural soil.
The Soil and Water Conservation Research Division, U.S. Department of Agricul-
ture vl°), is now working with legume growth at low soil pH using small amounts
of molybdenum (l to 2 pounds per acre - .1*5-to .91 kilograms per . UO hectare)
to supply requirements of the rhizobia. For legumes to grow well nodulation by
the nitrogen-fixing bacteria is essential. Ordinarily, rhizobia will not grow
at low pH levels. On spoils where it is impractical to apply lime, molybdenum
can be applied with the seed mixture. The use of molybdenum does not eliminate
the need to supply the other essential elements for plant growth.
Establishment of vegetation on an area must be done as soon after grading as
possible so as. to provide a quick protective cover for erosion control. Such
covers may include species of little or no commercial value. Fast growing
site stabilization species are given priority when making up the planting plan.
A mixture composed of several species is preferred over planting of a pure
single species (5). "By using mixtures, species can be selected that will yield
better economic return than either alone and provide quick and more complete
long-term cover. Mixtures are also less susceptible to disease and insect
epidemics and reduce danger of frost heaving of legumes. Species that have
compatible growth rates and have proven successful in the particular area under
similar site conditions should be used, and legumes should be included in all
mixtures because of their ability to fix nitrogen. Unfortunately, no one
mixture can be recommended that will establish, successfully in all kinds- of
spoil, topographic, and climatic conditions.
In most coal mining states, the Soil Conservation Service has developed or
assisted in development of handbooks to guide revegetation procedures. The
handbooks are based on data obtained from State and U.S. Department of
Agriculture research findings and are in the form of guidelines for use of
plant materials according to a spoil classification system. Soil Conservation
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Service technicians can predict plant performance for specific site conditions
and recommend the cultural and management techniques needed for establishment.
These technicians are available for assistance through local Soil and Water
Conservations Districtsv3o),
The Soil Conservation Service Plan Materials Centers are continuously searching
for new plant material that can "be field tested to determine its site
adaptability. As soon as its performance is confirmed, the plant is keyed to
the vegetation guide according to use and site requirements(36).
METHODS OF SEEDING AND PLANTING
Many factors must be considered when selecting the methods for seeding and
planting. These include:
1. Access to the area "by vehicles.
2. Location—availability of water, distance to airport.
3. Slope—especially steep outslopes.
It. Seedbed conditions—age of spoil, rainfall, and time since
final grading.
5. Topsoiling
6. Size of area
7. Time .of year.
The conditions pertaining to each site where seeding is to be done will
determine the method to be used.
Areas accessible by vehicles may be treated using conventional farming equip-
ment , mechanical tree planters, and hydraulic seeders. Use of mechanical
equipment is limited during wet, muddy, freezing, and thawing weather, which is
the ideal time to seed. The freezing and thawing action loosens the soil and
works the seed that has been broadcast on the surface into the soil. Early
germination and growth is thus obtained. Using conventional farming equipment,
the area is treated with agricultural lime, which is worked in with discs,
harrow, etc. Fertilizer may- be applied in the same manner or applied with the
seed. Seed is either broadcast or drilled.
Helicopters with motor-drive spreaders have been used successfully in rugged
terrain and in places where wheeled vehicles cannot operate beeause of wet,
muddy spoil, A heliport must be readily accessible to vehicles bringing in
loads of blended seed and fertilizer. The helicopter can hover and reload from
hopper trucks. A large area can be seeded in a short time when seedbed
conditions are most favorable. West Virginia uses the helicopter in rugged
mountain areas and has seeded several thousand acres (hectares) by this
method (Figure 83).
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Figure 83. Aerial seeding by helicopter (contour mining!
18U
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Fixed wing aircraft have been used with varying degrees of success in several
States. However, special detailed planning and preparations are required, A
landing field must "be nearby-, and mixing equipment for blending seed and
fertilizer is needed. Seeding areas must be flagged, and weather conditions,
particularly wind, have to be favorable. Large areas can be seeded fast and
with low per acre (hectare) costs. Spoils can be seeded during late winter
periods of freezing and thawing, when seedbed conditions are excellent. This
type of seeding lends itself very well to area mining and to orphan bank
reclamation because accessibility is not a prerequisite (Figure 8^ ).
If the area is small, it can be seeded with a hand operated cyclone seeder.
Regardless of the planting and seeding methods used, if the spoil is not loose,,
then seedbed preparation is necessary. The crusted, hard surface must be
scarified before seeding. This can be done with a disc, harrow, or ripper.
A heavy-duty seed drill has proven to be very outstanding on crusted spoils.
In areas of low rainfall, drilling of seed is mandatory to get acceptable
germination.
REVEGETATION OF AEID AM) SEMI ARID REGIONS OF THE WEST
Reclamation in the West is a new field of endeavor. Research has been conducted
on a very limited trial and error basis. Knowledge Of reclamation procedures
are inadequate and at this time recommendations cannot be made that will
guarantee complete success of reclamation efforts. Figure 85 shows area strip
mining near Gillette, Wyoming.
Curry'37) states, "we at present completely lack the necessary baseline data
upon which to assess or conduct reclamation."
Hardaway v38)^ reports that it is important to note that insofar as strip mining
(area or contour) of coal is concerned, there are no satisfactory reclamation
effort practices in Montana at this time. Though it is possible to regrade
disturbed land and that, in selected locations, true soils or "artificial" soils
can be found and successfully seeded, land areas comparable in size to mined
areas have not and are not being reclaimed. He also states that it cannot
be assured that reclamation will be successful in the West or that large scale
detrimental impacts of a substantially different or unusual nature may not occur
in the West.
The Bureau of Land Management, U.S. Department of the Interior's in their
land use studies for the Bull Mountain and Buffalo Creek area of Eastern
Montana, recommend that certain coal beds not be mined. This area is rim rock
country and most of the mining would have to be a contour type with some auger-
ing. Damages would be extreme, especially to the many scenic and natural,
winderoded formations. Slopes are steep, making reclamation very difficult and
costly(^0). it would be impossible to restore the drainage patterns and slopes
to their original forms. Extraction would create a relatively high degree of
surface disturbance per ton of coal
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,
Figure 8k. Aerial seeding by fixed wing aircraft (contour mining)
-------
Figure 85. Area strip mining near Gillette, Wyoming.
Problems of revegetating strip mine areas in the arid and semiarid West differ
drastically from those in the humid areas of the East. From the standpoint of
plant growth, climatic conditions are extreme. Seventy-five percent of the area
receives less than 20 inches (50.8 centimeters) annual precipitation available
for plant growth. Along with limited precipitation are seasonal temperature
variations from - 60 to 120 degrees F (-51 to ^9C)jshort frost-free periods,
wide variations in overburden material and lack of adequate topsoil. In some
cases the saving and spreading of topsoil can do more harm than good, — for
instance, where the calcium carbonate layer underlying much arid-land soil is
mixed with the nitrogen-rich organic layer and the biologic carbon-nitrogen
balance destroyed(37). Since evaporation is at the surface, minerals dissolved
in the soil water are precipitated in the upper strata and may cause highly
saline conditions that are toxic to plant establishment. Table 29 classifies
mine spoil according to reaction classes in order to identify and evaluate the
land use and treatment needed to stabilize and vegetate them for future use.
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Table 29. MINE SPOILS CLASSIFIED ACCORDING TO REACTION CLASSES
Reaction classes pH
Alkaline
Medium acid, slightly acid, and neutral
Very strongly acid and strong acid
Extremely acid
above
5.5 -
U.5 -
below
7.3
7.3
5.5
U.5
Water is a key factor to any successful reclamation program especially in the
West. Ample moisture at planting and during establishment is critical for re-
vegetation success. Irrigation is artificial addition of water to areas with
inadequate natural water supplies for the purpose of establishing vegetation it
should be used sparingly and in such quantities that the plants will not be
conditioned to the extra moisture. However, irrigation may be necessary during
peak plant demand and low rainfall the first year to ensure survival, particu-
larly for shrubs and trees. Other factors that must be considered in estab-
lishing vegetation on strip-mined areas include exposure, aspect, slope, pH
and salt content of the spoil material, texture, and climate. Any one or a
combination of these factors could be limiting and critical to plant growth.
set up a study area in the Kemmerer coal fields in southwestern
Wyoming. The study area is a part of the Northern Desert Shrub region and
receives an average annual precipitation of 9 .k2. inches (23.92 centimeters).
Much of the precipitation occurs as snow, with an average fall of 56.6 inches
(lit3.76 centimeters). In this area, snow has several peculiarities. It
occurs after the ground is frozen, so any snow that melts is subject to runoff
rather- than percolation into the soil. Snow is also blown about and distri-
buted in uneven patterns. Many areas catch little snow, while others, such as
gullies and leeward sides of wind obstructions receive large amounts. Snow
also is vulnerable to sublimation, a process by which solids pass directly into
a gaseous state without being transformed to liquid. It is not uncommon for
60$ to 80% of a snowfall to be sublimated, leaving 20 to kO% of the moisture
content to be transformed into water, which may or may not penetrate the soil
surface. In short it is not unreasonable to estimate that of the 9.^2 inches
(23.92 centimeters) of annual precipitation, less than 5 inches (12.7 centi- ,
meters ) are available for plants .
Three studies were conducted on the Kemmerer coal spoil banks: (l) use of various
species of trees, fertilizer, and irrigation; (2) use of four species of grass
seed and various means of holding moisture; (3) transplanting sod chunks and
sprigs or two rhizomatous species with different means of holding moisture.
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Conclusions from the tree planting study shoved that watering the trees during
mid and later summer greatly increased survival percentage, growth., and vigor.
Survival differences as high as 50$ were observed between trees on irrigated
plots and those that were not irrigated, those that were not fertilized, or
those that received no treatment (control).
Conclusions from the grass-seeding study, which included treatment of test plots
with jute net, barley straw, mulch, snow fence, irrigation, and combinations of
these are as follows:
1. Available moisture was a principal limiting factor in plant establish-
ment, but this could be supplemented by snow-fences and irrigation
from nearby permanent ponds. Snow-fences were effective means of
acquiring additional moisture for plant growth only when placed on
the leeward side of large, open, level areas.
2. Mulch, necessary for good seedling establishment, required some means
of holding it in place. Annual plants grown for a nurse crop served
both as mulch and for erosion control, but they in turn depended on
ample precipitation for optimum growth.
3. Jute netting served as a means of erosion control and as a partial
mulch. Stabilization of erosion was a prerequisite for successful
revegetation on slopes.
Conclusions from the grass transplanting study using sprigging and sodding are
as follows:
1. The best time of year to-plant was in spring. Early fall planting
proved least successful, and late fall planting was not tested.
2. Sodding produced far better results than did sprigging. Roots within
sod clumps stayed moist and were protected by the surrounding soil,
whereas in sprigging, roots were damaged and-moisture was lost from
plants being prepared for planting.
3. Planting behind snow-fences resulted in slightly better survival
because of early spring snow melt behind the fences and the wind
break provided by the snow-fence.
k. The most limiting factors influencing vegetative establishment was
the amount of precipitation received just before, during, and
immediately after planting time.
The overall conclusions of Lang^l) were:
1. Ample moisture at planting and during establishment was critical
for stand success with seeded grasses, planted trees, and grass sod or
sprigs. Irrigation and/or the use of snow-fences to accumulate extra
moisture increased the percentage stand establishment of all types of
vegetation.
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2. Russian olive and caragana were the best of the tree species tested,
and the top part of east and northeast-facing slopes were the best
sites for their establishment.
3. Intermediate and crested wheatgrass appeared to be the best adapted
of the cool-season grass species seeded. The most satisfactory stands
of all species were obtained where mulch with some type of netting
to hold it in place was used with the seeding or where the seeding
received additional moisture benefits from being on the leeside of
a snow-fence.
h. Sodded grasses were most effectively established on the flat top of
the spoil piles, whereas tree species and seeded grasses were more
effectively established on northeast- and east-facing slopes.
5. Nitrogen fertilization did not significantly affect establishment of
either grasses or trees.
after a 3-year study of snowdrift management at an open range site
in eastern Montana, indicated that standard snow-fence can effectively induce
snowdrifts on water-harvesting catchment basins. Although water loss by evapor-
ation from induced snowdrifts averaged 50$, runoff was increased by an average
k.k inches (11.17 centimeters) during the winter season. Water harvesting is
defined as the practice of collecting and storing precipitation from an area
that has been treated to increase runoff. Acceleration of snow melt by applying
lamp black, pulverized lignite or other heat adsorptive dust could reduce eva-
porative exposure time and increase runoff yield. The use of snow fences has
proven to be a feasible method of accumulating extra moisture that is helpful
for plant establishment and growth during criti cal periods .
In nearly all instances , snow-fences have incrased the percentage of stand
survival of all types of vegetation.
Several systems of water retention on spoils have been tested and evaluated by
Sindelar et al.,(2). The section entitled Mechanical Spoil Manipulation con-
tains a detailed discussion of gouging, dozer basins, and deep chiseling, which
have proven to be successful in trapping moisture for seed germination and
survival, controlling erosion, relieving compaction, and improving the spoil
moisture reserve.
Direct seeding of most trees and shrubs is unsatisfactory under arid and semi-
arid conditions . They must be established by planting seedlings or trans-
plants (6). Hodder(^3; has developed three dryland planting techniques for trees
and shrubs, which are now being tested. They are: condensation traps, supple-
mental root transplants , and tubelings .
Condensation traps are made by digging a small basin for each plant. The entire
basin is covered with a plastic sheet and heeled in around the edge to contain
a large amount of air. The foliage of the plant is guided through a hole in the
plastic sheeting. Rocks are placed on the tarp around the plant to provide pro-
tection and to weight the plastic and keep it taut in a funnel form. Condensate
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collecting on the underside of the plastic sheet trickles down to the plant
location and effectively irrigates it, Supplemental root transplanting is
accomplished "by carefully removing a pair of interconnected seedlings of a
rhizomatous shrub species. The top of one seedling is pruned off at the crown,
leaving two root systems connected to the uncropped seedling.
The horizontally connected root systems are then planted in a vertical attitude,
one being placed down in deep soil moisture, and the other planted in a
normal manner in the drier surface soil.
Tubelings are plant seedlings planted and nursery developed in two-ply paper
cores or tubes. The tubes are 2 l/2inches (6.35 centimeters) in diameter and
2 feet (.60 meters) long. The paper core is reinforced with a 1/2 inch
(1.2T centimeters) square mesh plastic sleeve. When the root system develops
and extends from the bottom and sides of the tube, the tubeling is ready for
transplanting. A powered soil auger is used to drill holes in the field.
Tubelings are dropped in, sealed around the top, and abandoned without further
care of maintenance.
Seeding of grasses and legumes include the following methods
1. Drilling. Wherever possible, grasses and legumes should be
drilled. The recommended planting depth is 1/2 to 3A inch
(l.2T to 1.9 centimeters) and is best accomplished by using a drill
equipped with depth bands and packer wheels.
2. Broadcast seeding. Broadcast seeding is satisfactory for small or
inaccessible areas. The surface should be rough enough that the
seed will be covered. Roughening is best accomplished by dragging
with a harrow, disking, or dragging with a heavy-spiked chain.
Broadcast seeding may also be satisfactory when seeding immediately
after construction, before the surface has become crusted, or
before mulching.
3. Hydroseeders. Hydroseeding has not generally given good results under
climatic conditions similar to thqse where open-cut mining will be
done in Montana. Accessibility and available water are also limita-
tions to their use. Mulching is usually necessary.
IK Aerial seeding. Aerial seedings have not generally been satisfactory
in the precipitation zones that will be encountered in most of
Montana's surface-mined areas. However, if the surface is rough
enough that the seed will be covered by rain or wind action, satis-
factory stands may possibly be obtained. Helicopters are superior
to fixed-wing aircraft.
Seeding rates and species should be obtained from local agriculture agencies
who are familiar with local conditions.
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It is assumed that no mining will commence until detailed mining and reclama-
tion plans have been approved by the responsible permitting agency. These
plans should, as standard procedures, require spoil segregation and placement
according to the core drill analysis and soil analysis made during the pre-
planning phase. They should also include topsoiling, slope restoration, and
the regeneration of the native, self-sustaining plant community. Introduced
species may permit quick stabilization, but ultimately,, the dominant cover
should be native species. This means that a seed source must be developed to
furnish the large quantities that will be needed.
Through research and experience, unproven reclamation trends have developed that
can be used as guidelines for preplanning the mining operation; if such guide-
lines are followed during mining, they should make restoration of the disturbed
land possible. At this point in time it must be accepted, however, that certain
areas cannot be mined because of the limited knowledge and techniques for
restoring mined land in the arid and semiarid West.
Assuming that reclamation is effective, there would still be a considerable de-
lay before land could be returned to its original use. Until the vegetative
cover is firmly established, grazing would be discouraged and must be controlled.
192
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1. Caruccio, Frank T. An Evaluation of Factors Affecting Acid Mine Drainage
Production and the Ground Water Interactions in Selected Areas of Western
Pennsylvania. Second Symposium on Coal Mine Drainage Research, Pittsburgh,
Pennsylvania, May 1968.
2. Sindelar, Brian W., Hodder, Richard L., Majerus, Mark E., Surface Mined
Land Reclamation Research in Montana, Progress Report 1972-1973. Montana
Agricultural Experiment Station, Montana State University, Bozeman,
Montana.
3. Lyon, T.L., Buckman, H.O., and Brady, N.C., The Nature and Properties of
Soil. 5th Ed., Macmillian Company, New York, 1952.
IK Personal Communication. Heddleson, J.P., Department of Agronomy, Ohio
State University, Columbus, Ohio, 1959.
5. Grant, A.F., and Lang, A.L., Reclaiming Illinois Strip Coal Land with
Legumes and Grasses. Bulletin 628, University of Illinois, Agriculture
Experiment Station, Urbana, Illinois, 1958.
6. Kentucky Guide for Classification, Use, and Vegetative Treatment of Surface
Mine Spoil. U.S. Department of Agriculture, Soil Conservation Service,
Lexington, Kentucky, 1971.
7. Davis, Grant, Strip-Mine Reclamation in Appalachia (Review Draft). U.S.
Department of Agriculture, Forest Service, Northeastern Forest Experiment
Station, July 1971.
8. Plass, William T., Highwalls—An Environmental Nightmare. Paper presented
at the symposium on Revegetation and Economic Use of Surface-Mined Land
and Mine Refuse, Pipestem State Park, West Virginia, December 1971.
9. Curtis, Willie R., Vegetating Strip-Mine Spoils for Runoff and Erosion
Control. Paper presented at the symposium on Revegetation and Economic
Use of Surface-Mined Land and Mine Refuse, Pipestem State Park, West
Virginia, December 1971.
10. Riley, Charges V., Furrow Grading—Key to Successful Reclamation. Paper
presented at the Research and Applied Technology Symposium on Mined-Land
Reclamation, Pittsburg, Pennsylvania, March 1973,
11. Personal Communication. Benjamin C, Greene, Chief, Division of Reclama-
tion, Department of Natural Resources, Charleston, West Virginia,
July 1973.
12. Personal Communications. William E. Guckert, Director, Bureau of Surface
Mine Reclamation, Department of Environmental Resources, Harrisburg,
Pennsylvania, April 1973.
193
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13. Guidelines for Erosion and Sediment Control Planning and Implementation,
Environmental Protection Technology Series, EPA-R2-72-015 August 1972,
Project 15030 FMZ. Prepared by Department of Water Resources, State of
Maryland, and ffiLttman Associates, Inc., Columbia, Maryland.
lU. A Manual of Kentucky Reclamation by Kentucky Department for Natural Re-
sources and Environmental Protection, Frankfort, Kentucky, May 1973.
15- Grube, Walter E. Jr., Smith, Richard M., Singh, Rabindar, and Sobek,
Andrew A. Characteristization of Coal Overburden Materials and Mine
Spoils in Advance of Surface Mining. Paper presented at the Research and
Applied Technology symposium on Mined-land Reclamation, Pittsburg,
Pennsylvania, March 1973.
16. Mine Spoil Potentials for Water Quality and Controlled Erosion. Prepared
by the Division of Plant Sciences, West Virginia University for the
Environmental Protection Agency, Project Number 1^010 EJE, December 1971,
Water Pollution Control Research Series.
17. Bengston, G.W., Mays, D.A., Allen, J.C., Revegetation of Coal Spoil in
Northeastern Alabama: Effects of Timing of Seeding and Fertilization on
Establishment of Pine-Grass Mixtures. Paper presented at the Research and
Applied Technology Symposium on Mined-Land Reclamation, Pittsburg,
Pennsylvania, March 1973-
18. Bennett, O.L., Grasses and Legumes for Revegetation of Strip-Mined Areas.
Paper presented at the Symposium on Revegetation and Economic Use of
Surface Mined Land and Mine Refuse, Pipestem State Park, West Virginia,
December 1971.
19. Adams, L.M., Capp, J.P., Gillmore, D.W., Coal Mine Spoil and Refuse Bank
Reclamation With Powerplant Fly Ash. Paper Presented at the Third Mineral
Waste Utilization Symposium, Chicago, Illinois, March 1972.
20. Plass, W.T., Capp, J.P., Physical and Chemical Characteristics of Sulfur
Mine Spoil Treated with Fly ASh. Journal of Soil and Water Conservation,
Vol. 29, No.3, May-June 19TU.
21. Ash at Work, Published by National Ash Association, Washington, D.C.,
Vol. Ill, No,2, 1971. Article titled, "Plant Nutrient Study at VPI Shows
Results".
22. Barber, E.G., PFA Utilization, Chapter 9, "The Treatment and Cultivation
of PFA Surfaces". Published by the Ash Marketing Division, Central
Electricity Generating Board, 15 Newgate Street, London, England, 1972.
23. Adams, L.M., Capp, J.P,, Eisentrout, E. Reclamation of Acidic Coal Mine
Spoil with Fly Ash. U.S. Department of Interior, Bureau of Mines Report
of Investigation Number 750U, April 1971.
-------
2lt. Gillmore, D,W,, Capp, J.P, Reclamation of Spoil, and Refuse Banks with
Powerplant Fly Ash. Paper presented at the AIME annual meeting, San
Francisco, California, February 1972,
25. Hinesly, T.D., Jones, R.L., Sovewitz, Ben, Use of Waste Treatment Plant
Solids for Mined Land Reclamation. Article in Mining Congress Journal,
September 1972.
26. Dick, R.I., and Associates. Influence of Soil Moisture on Fecal Coliform
Survival. Section of environmental protection publication in the solid
waste management series CSW-30d) U.S. EPA, Cincinnati, Ohio, 1971.
27. Rose, B.A. Sanitary District Puts Sludge to Work in Land Reclamation.
Article in Water and Sewage Works, A Scranton Gillette Publication,
September 1968.
28. Peterson, J.R., Gschwind, J. , Amelioration of Coal Mine Spoils with
Digested Sewage Sludge. Paper presented at the Research and Applied
Technology Symposium on Mined-Land Reclamation, Pittsburg, Pennsylvania,
March 1973.
29. Palzo Restoration Project, Final Environmental Statement, Shawnee National
Forest; Eastern Region, Forest Service, U.S. Department of Agriculture,
July 1972.
30. Rand Development Corporation. Strip Mine Disposal of Sewage Solids.
Grant from U.S. Department of Health, Education, and Welfare, Contract No.
PH 86-65-21, February 1965.
31. Hinesly, T.D., Braids, O.C., Molina, J.E., Agricultural Benefits and
Environmental Changes Resulting from the Use of Digested Sewage Sludge on
Field Crops. U.S. Environmental Protection Agency (SW-30d), Cincinnati,
Ohio, 1971.
32. Dotson, G.K. Constraints to Spreading Sewage Sludge on Croplands.
U.S. Environmental Protection Agency, Advanced Waste Treatment, National
Environmental Research Center, Cincinnati, Ohio,1973.
33. Composting of Municipal Solid Wastes in the United States. U.S. Environment-
al Protection Agency (SW-l*7r), National Environmental Research Center,
Cincinnati, Ohio, 1971.
3*K Gregory, Clark. Composting in America, or How I Learned to Start Living
and Love the Soil. Environmental Research Group, Georgia State University,
Atlanta, Georgia, 1972.
35. Duggan, Carroll, Scanlon, David H,, and Bean, S.D. Evaluation of Municipal
Compost for Strip Mine Reclamation. Compost Science; Journal of Waste
Recycling, lU,(3), May-June 1973.
195
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36. Ruffner, Joseph D. Projecting the Use of New Plant Materials for
Special Reclamation Problems, Paper presented at the Research and Applied
Technology Symposium on Mined^Land Reclamation, Pittsburg, Pennsylvania,
March 1973.
37. Curry, Robert R. Reclamation Considerations for the Arid Lands of
Western United States. Testimony for U.S. Senate Interior Hearings,
March 1973. Associate Professor, Environmental Geology, University of
Montana, Missoula, Montana.
38. Hardaway, John E., Report of Inspection of Coal Lands on Crow Indian
Reservation and Vicinity, Billings-Hardin-Crow Agency, Montana, May lU-18,
1973. EPA, Region VIII, Denver, Colorado.
39. Bull Mountain and Buffalo Creek Land Use Recommendations. U.S. Department
of the Interior, Bureau of Land Management, P.O. Box 2020, Billings,
Montana, 1973.
UO. Coal Development in Eastern Montana. A situation report of the Montana
Coal Task Force, January 1973. Published by the Department of Natural
Resources and Conservation, Helena, Montana.
Ul. Lang, Robert. Reclamation of Strip Mine Spoil Banks in Wyoming. Research
Journal 51, Agricultural Experiment Station, University of Wyoming,
Laramie, Wyoming, September 1971.
U2. Saulman, Robert W., Snowdrift Management Can Increase Water-Harvesting
Yields. Journal of Soil and Water Conservation, 28 (3), May-June 1973.
U3. Hodder, Richard L. Surface Mined Land Reclamation Research in Eastern
Montana. Paper presented at the Research and Applied Technology Symposium
on Mined-Land Reclamation, Pittsburg, Pennsylvania, March 1973.
UU. Guidelines for Reclamation of Surface-Mined Areas in Montana. U.S.
Department of Agriculture, Soil Conservation Service, Bozeman, Montana,
August 1971.
196
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SECTION X
ACID MIKE DRAINAGE
FORMATION OF ACID MINE DRAINAGE (AMD)
The removal of overburden often exposes pyritic materials (iron disulfide).
As shown in equations 1 and 2, the oxidation of this material results in the
production of ferrous iron and sulfuric acid. The reaction then proceeds to
form ferric hydroxide and more acid, as shown in equations 2 and k.
2FeS2 + 2H20 + 702 — * 2FeS01| + 2H2SO]^ (l)
(Pyrite) — > (Ferrous Iron) + (Sulfuric Acid)
FeS2 + l^Fe+3 + 8H20 — *, 1 5Fe+2 + 2SO^ ~2 + I6E+ (2)
(Pyrite) + (Ferric Iron) (Ferrous Iron) + (Sulfate) (Acid)
+ 2H20 (3)
+ 6H20 — t, 2Fe(OH)3 + SHgSO^ (U)
Consequently a low pH water is produced (pH 2-k . 5 ) • At these pH levels , the
heavy metals such as iron, manganese, copper, and zinc are more soluble and
enter into the solution to further pollute the water. Water of this type
supports only limited water flora, such as acid-tolerant molds and algae; it
will not support fish life, destroys and corrodes metal piers, culverts, barges,
etc., increases the cost of water treatment for power plants and municipal
water supplies , and leaves the water unacceptable for recreational uses .
The amount, and rate of acid formation, and the quality of water discharged
are a function of the amount and type of pyrite in the overburden and coal,
time of exposure, characteristics of the overburden, and amount of available
water (l). Crystalline forms of pyritic material are less subject to weathering
and oxidation than amorphic forms. Since oxidation by oxygen is the primary
reaction during early acid formation, the less time pyritic material is
exposed to air, the less acid is formed. Thus, a positive preventative method
is to cover pyritic materials as soon as possible with earth, which serves as
an oxygen barrier. In terms of mining, this step is accomplished by current
reclamation techniques and small open pits.
197
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If the overburden also contains alkaline material such as limestone, acid water
may not be discharged even though it is formed, because of inplace neutraliza-
tion by the alkaline material. Discharges from this situation are usually high
in sulfate.
Enough water to satisfy equations 1,2, and U is usually available in the over-
burden and coal material. Water also serves as the transport media that
removes the oxidation products from the mining environment into streams.
ACID PREVENTION
All techniques for preventing acid formation are based on the control of
oxygen. There are two mechanisms by which oxygen can be transported to pyrite
—convective transport and molecular diffusion^2'.
The major convection transport source is wind currents that can easily supply
the oxygen requirement for pyrite oxidation at the spoil surface. In addition,
wind currents against the steep slope would provide sufficient pressure to
drive oxygen deeper into the spoil mass. One factor in considering the degree
of slope for regrading, especially on sides subject to prevailing winds, is
that the wind pressure on the spoil surface increases as the slope increases.
Thus the depth of oxygen movement into the spoil would increase as the slope
increases.
Molecular diffusion occurs whenever there is an oxygen concentration gradient
between two points, that is, the spoil surface and some point within the spoil.
Molecular diffusion is applicable to any fluid system, either gaseous or liquid.
Thus oxygen will move from the air near the surface of the spoil, where the
concentration is higher, to the gases or liquid-filled pores within the spoil,
where it is lower. The rate of oxygen transfer is strongly dependent on the
fluid phases and is generally much higher in gases than in liquids. For
example, the diffusion of oxygen through air is approximately 10,000 times as
great as in water(2). Therefore, even a thin layer of water '(several milli-
meters) serves as a good oxygen barrier.
The most positive method of preventing acid generation is the installation of
an oxygen barrier. Artificial barriers such as plastic films, bituminous,
and concrete would be effective, but these have high original and maintenance
costs and would be used only in special situations.
Surface sealants such as lime, gypsum, sodium silicate, and latex have been
tried, but they too suffer from high cost, require repeated application, and
have only marginal effectiveness. The two most effective barrier materials
are soil, including non-acid spoil and water. A 2 foot (0.6l meters) minimum
thickness of soil or non-acid spoil that is required as a barrier is a function
of the soils physical characteristics, soil compaction, moisture content, and
vegetative cover. Deeper layers of a sandy, dry granular material with large
grain size and porosity would be required than a tightly packed saturated clay
that is essentially impermeable. Soil thickness sould be designed on the basis
of the worst situation—when the soil is dry and oxygen can move more readily
through cracks and pore spaces devoid of water. A "safety factor" should be
included to account for soil losses such as erosion. Vegetation not only
198
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serves as a barrier, because the pores are filled water and not gases. As the
vegetation dies, it "becomes an oxygen user during the decomposing process and
further aids the effectiveness of the barrier. The organic matter that is
formed further aids in holding moisture in the soil.
Water is an extremely effective barrier vhen the pyritic material is permanently
covered. Allowing the pyrite to pass through cycles where it is uncovered and
then covered will worsen the AMD problem. Water barriers should be designed to
account for water losses such as evaporation and include at least 30 centimeters
(l foot) of additional depth as a safety factor.
ACID CONTROL
Additional measures to control AMD are water control and inplace neutralization.
Water serves not only as the transport media that carries the acid pollutants
from the pyrite reaction sites and mine, but it also erodes soil and non-acid
spoils to expose additional pyrite to oxidation. Facilities such as diversion
ditches that prevent water from entering the mining area and/or carry the water
quickly through the area can significantly reduce the amount of water available
to transport the acid products. These facilities, which are discussed under
Section VI, Sediment and Erosion Control, are needed both during and following
mining. Terraces, mulches, vegetation, etc. used to reduce the erosive forces
of water are effective measures to prevent further pyrite exposure. These
measures usually are performed during reclamation.
Alkaline overburden material and agricultural limestone can be blended with
"hot" acidic material to cause in-place neutralization of the acid and assist
in establishing vegetation. In some cases, alkaline overburden can be graded
to cause acid seeps to drain through it(3). These techniques are more
applicable to abandoned surface mines than to current mining, where proper
overburden handling should prevent acid formation. The major exception may be
those situations where an underground mine was breached and an acid discharge
formed.
ACID TREATMENT
Where the formation of AMD cannot be prevented or the discharge controlled,
treatment is necessary before the water can be discharged. The only method
being used today for treating AMD is neutralization. The neutralization process
provides the following benefits:
1. Neutralization removes the acidity and adds alkalinity.
2. Neutralization increases pH.
3. Neutralization removes heavy metals. The solubility of heavy metals
is dependent on pH up to a point: the higher the pH, the lower the
solubility.
199
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U. Ferrous iron, which is often associated with AMD, oxidizes at a
faster rate to ferric iron at higher pH's. Iron is usually removed
in the ferric form.
5. Sulfate can be removed if sufficient calcium ion is added to exceed
the solubility of calcium sulfate; however, only in highly acidic AMD
does this occur.
Some shortcomings of the neutralization process are:
1. Hardness is not reduced and may be increased.
2. Sulfate is not reduced to a low level it usually exceeds 2,000
milligrams per liter.
3. The iron concentration usually is not reduced to less than 3 to 7
milligrams per liter.
k. A waste sludge is produced that must be 'disposed of.
5. Total dissolved solids concentration is increased.
A typical neutralization system would include adding an alkaline reagent,
mixing, aerating, and removing the precipitate. Alkaline reagents that
may be used are ammonia, sodium carbonate, sodium hydroxide, limestone,
and lime (See Figure 86).
LIME TREATMENT
Lime treatment is the most commonly used system. The lime reactions with AMD
are as follows :
Ca(OH)2 + E2SO]4 - > CaSOlj + 2 HO (5)
(Lime) + (Sulfuric Acid) - > (Calcium Sulfate) + (Water)
Ca(OH)2 + Fe SO^ - » Fe (OH)2 + CaSO^ (6)
(Lime) + (Ferrous Sulfate) - > (Ferrous Hydroxide) +
(Calcium Sulfate)
3Ca(OH)2 + Fe2(S01|)3 - > 2 Fe (OH)3 + 3 CaSO^ (7)
(Lime) + (Ferric Sulfate) (Ferric Hydroxide) + (Calcium Sulfate)
As shown in Figure 86, AMD is discharged from the mine directly to a rapid mix
chamber or to a holding/flow equalizing pond where it flows to the rapid mix
chamber. Hydrated lime is either fed to the rapid mix chamber either as a
slurry or dry. If the ferrous iron concentration is low (less than 50 mg/l),
the water is treated to a pH of 6.5 to 8 and flows directly to the settling
200
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MINE
ro
o
ACID MINE
DRAINAGE
AMD
REAGENT
STORAGE
HOLDING
POND
FERROUS IRON AMD
TREATED
WATER
»- ALTERNATIVE PATHS
FERRIC IRON AMD
SLUDGE
DISPOSAL
CLARIFIER
POND
STRIP PIT
POND
STRIP PIT
UNDERGROUND MINE
LANDFILL
Figure 86. Typical treatment plant.
-------
chamber. If the ferrous iron is high, the pH is usually raised to a higher
level (8 to 10) and then passed to an aeration tank vhere the ferrous hydroxide
percipitate is converted to ferric hydroxide. Then the vater flovs to a
settling chamber. The settling chamber may be a clarifier or pond. Here the
iron, aluminum, calcium sulfate, and other heavy metals precipitate. The
supernatant is the treated water. The precipitate or sludge is removed from
the settling chamber and disposed of in a second pond, strip mine pit,
underground mine, or landfill. In some cases, the pond serves as a settling
chamber and permanent storage place for the sludge.
Except for large surface mines, lime systems are usually much less sophisticated
than the one described above (Figure 87). They may be as simple as catching all
the AMD in a small pond, then broadcasting by hand lime on the surface of the
pond. This system is only effective vhen the pond is less than 1,000 square
meters (0.25 acres). Mixing of the lime and acid water is poor in this system,
and excess lime is required. After the water is treated, it is pumped from the
pond.
^\.:vrvt> ;*.- -/-
. -
V- - ;
Figure 87. Simple lime reagent feeder.
202
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Water can also be treated as it is pumped from the pit by connecting a lime
slurry tank to the suction end of the pump. As the water is pumped, the lime
slurry is drawn into the AMD by the suction of the pump; the pump also serves
to mix the lime and acid water. The discharge from the pump should pass
through a settling pond to remove any precipitates. Appendix H discusses
this method in detail.
Commercial units such as those shown in Figure 88, which include automatic
pH control, are available on the market.
LIMESTONE TREATMENT
The limestone reactions with AMD are as follows:
CaC03 + HgSO^ v CaSO^ + H20 + C02 (8)
(Limestone) + (Sulfuric Acid) (Calcium Sulfate) + (Water) +
(Carbon Dioxide)
3CaC03 + Fe2(SO^)3 + 3 H20 3 CaSO^ + 2 Fe(OE)3 + 3 C02 (9)
(Limestone) + (Ferric Sulfate) + (Water) (Calcium Sulfate) +
(Ferric Hydroxide) + (Carbon Dioxide)
Although limestone is a cheaper reagent than lime and produces less and
denser sludge, it has not received wide acceptance for several reasons:
(l) the carbon dioxide produced buffers the reaction, and it is difficult to
raise the pH above 6 without using excessive material; (2) limestone is
ineffective with high ferrous iron water; (3) the size, characteristics, and
method of application of the limestone are critical; and (U) the system is
usually more complex than lime.
Several different treatment schemes have been utilized with limestone'^'.
Those most applicable to surface mine situations are streambed and ground
limestone techniques. The simplest method is the placement of limestone in
a streambed. The acid water is treated as the water flows through the bed.
This method has proven to be ineffective in most cases because the limestone
quickly becomes coated with iron, calcium sulfate, sediment, and biological
growths that prevent the acid water from reacting with the limestone. The
method may have application for short-term temporary situations where any one
installation will not be used for more than a month. A trench should be dug
leading from the surface mine and filled with crushed limestone (2.5 centi-
meters or 1-inch size). Basins to settle out any silt before the trench and
a second to settle out the precipitate should be used. Surface water should
be diverted away from the trench to prevent the limestone from being washed
out during storms. If the limestone bed loses its effectiveness, the stone
should be replaced or a new trench dug.
203
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Figure 88. Commercial lime treatment plant,
Pulverized limestone can be used in a manner similar to lime. The following
factors should be considered in the selection of a limestone: (l) high calcium
carbonate content, (2) lov magnesium content, (3) low amount of impurities, and
(U) large surface area i.e., smallest particle size within economic bounds
—200 mesh or smaller is preferable). Methods for selecting limestone have
been developed (^>5). The pulverized limestone can be fed as a slurry or dry.
Two to three times the stiochiometric amount of limestone will probably be
required, and even then a pH of only 6 to 6.5 will be reached. The reaction
time of limestone is much slower than lime, and up to 30 minutes of mixing
should be provided.
The split treatment of AMD with limestone and lime may offer some advantages in
cost and improved sludge characteristics. It might also be used on ferrous-iron
AMD. A two-step process is required. First, the AMD is treated with limestone
to a pH of U.O to U.5 to take advantage of the pH range when limestone is
most effective. The water then passes to a second reactor where lime is applied
to raise the pH to the desired level. This process may have a cost advantage
20U
-------
over lime alone and the desired sludge characteristics of the limestone process.
Holland et al(6) found that with the proper combination of limestone aud lime,
a good effluent could be obtained even with ferrous AMD. This system is
probably only applicable to large installations.
ANHYDROUS AMMONIA
Anhydrous ammonia has been utilized for the neutralization of AMD. Such a
system is attractive from the standpoint of ease of operation and maintenance.
Usually, the only equipment used is a tank of anhydrous ammonia, a length of
hose to discharge the material into the AMD, and a valve to control the flow of
gas. Anhydrous ammonia is usually supplied by the dealer in pressurized tanks
mounted on wheels. The user needs only the hose and valve. The tanks are
easily moved from site to site and can be set up in a matter of minutes.
The disadvantages of anhydrous ammonia(T) are: (l) ammonia is lost to the
atmosphere by diffusion or by air-stripping where aeration is practiced;
(2) more sludge may be produced; (3) the reagent cost is higher than lime
or limestone; and (U) ammonia-neutralized AMD may have a detrimental effect on
a receiving stream because of the toxicity of ammonia to fish and aquatic life,
the depression of dissolved oxygen levels as a result of nitrification, and
nitrate enrichment, which may lead to accelerated eutrophication.
The detrimental effect on receiving streams is significant enough to warrant the
recommendation that anhydrous ammonia not be used to treat AMD except under
special conditions. Zavel and Penrose(T) reported ammonia nitrogen levels as
high as 1,625 milligrams per liter in AMD neutralized with anhydrous ammonia in
laboratory studies. Hill(8) found nitrate N levels as high as U80 milligrams
per liter in AMD being treated with anhydrous ammonia in Western Kentucky.
These levels of ammonia and nitrate are beyond desirable limits for stream. The
only situation where anhydrous ammonia may be acceptable is where small volumes
of AMD are to be treated, and all the treated water is applied to spoil banks
as irrigation water and"no runoff occurs. In this situation, the stream is not
damaged, and the vegetation on the spoils receive the benefit of water and
nitrogen.
SODA ASH
Sodium carbonate has been utilized for the treatment of AMD because of the
simple feeders that have been developed (Figure 89). In most cases, soda ash
briquettes have been used. A portion or all of the AMD is passed through a
container holding the briquettes. The briquettes dissolve, neutralizing the
water. These systems, which are usually used on small flows, are temporary and
are easily moved. Their disadvantages are that good control of pH cannot be
maintained, and at very high flows, they under treat. Also, higher cost of soda
ash militate it's use.
205
-------
•V
Figure 89. Treatment of AMD with soda ash briquettes.
SODIUM HYDROXIDE
One neutralizing system on the market uses sodium hydroxide. The addition of
sodium hydroxide is controlled by the water level in a small flume (Figure 90).
Kennedy (9) reported that the device was suitable for remote location because it
was easily moved, required no electricity or power, and was simple to operate.
The device is best suited for small flows. A baffle downstream of the device
that ensures good mixing and a settling pond is desirable for best operation.
The cost of sodium hydroxide is much higher than lime or limestone.
SUMMARY
AMD is formed by the oxidation of pyritic material located in the overburden
and coal measures. The most positive preventive method is good planning,
mining, and reclamation. Backfilling and reclamation should be performed
206
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CHEMICAL
FEED
RESERVOIR
NaOH SOLUTION
STORAGE
FEED ADJUSTMENT
ORIFICE AND METERING ROD
FLUME
FLOW
STILLING WELL
(MAINSTREAM FLOW
INDICATOR)
Figure 90. Chemical feeder for treating mine drainage.
207
-------
concurrently with mining, and the amount and time a pit is open should be held
to a minimum to prevent pyrite oxidation. As much water as possible should
be diverted away from or carried rapidly through the area disturbed by mining
in order to reduce the water available for flushing oxidation and erosion
products.
During reclamation all pyritic material should be covered with sufficient soil
or non-acid spoil to serve as an oxygen barrier and supply a good growth media
for vegetation. Erosion control practices should be followed. The permanent
flooding of pyritic material is also a good oxygen barrier.
Several neutralization methods are available to treat any AMD that occurs in
spite of the above practices. Neutralization will raise the pH, remove the
acidity, and reduce heavy metals such as iron and aluminum. It will not reduce
the sulfate level, and it may increase the calcium and sodium and dissolved
solids concentrations. Anhydrous ammonia is not recommended for treating AMD
except where there is no discharge to streams.
208
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(
1. Morth, A.H., Smith, E.E. and Shumate, K.S., Pyritic Systems: A Mathe-
matical Model, Publication No. EPA-R2-72-002, Environmental Protection
Technology Series, U.S. Environmental Protection Agency, Washington, D.C.,
Nov. 1972.
2. Acid Mine Drainage Formation and Abatement, Ohio State University
Research Foundation, Water Pollution Control Research Series No. DAST-^2,
1^010 FPR OU/71, U.S. Environmental Protection Agency, Washington, D.C.,
April 1971-
3. Processes, Procedures, and Methods to Control Pollution from Mining
Activities. Publication No. EPA-U30/9-73-011, U.S. Environmental
Protection Agency, Washington, D.C., Oct. 1973.
it. Hill, R.D., and Wilmoth, R.C., Limestone Treatment, of Acid Mine Drainage
Transactions Society of Mining Engineers, 250(2): l62-l66, June 1971.
5. Studies on Limestone Treatment of Acid Mine Drainage, Federal Water Quality
Administration Research Series lUOlO EIZ 01/70, Washington, D.C., Jan 1970.
6. Holland, C.T., Berkshire, R.C., and Golden, D.F., An Experimental Investi-
gation of the Treatment of Acid Mine Water Containing High Concentrations
of Ferrous Iron with Limestone. Third Symposium on Coal Mine Drainage
Research, Mellan Institute, Pittsburgh, Pennsylvania, May 1970.
7. Zaval, Frank,' and Penrose, Ray, Neutralization of Acid Mine Drainage Using
Anhydrous Ammonia. An Engineering Report to the Commonwealth of Kentucky
and U.S. Environmental Protection Agency performed under Project lUOlO HNS,
Environmental Protection Agency, Cincinnati, Ohio January 1973.
8. Hill, R.D., Letter to Commonwealth of Kentucky Reporting Results of
Analysis of Water Treated with Anhydrous Ammonia. U.S. Environmental
Protection Agency, Cincinnati, Ohio, May 2U, 1973.
9. Kennedy, James L., Sodium Hydroxide Treatment of Acid Mine Drainage.
U.S. Environmental Protection Agency, Cincinnati, Ohio,February 1973.
209
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SECTION XI
RESEAECH, DEVELOPMENT AND DEMONSTRATION NEEDS
1. Potential ground-water pollution resulting from large-scale surface mining
in western states should "be evaluated.
2. Criteria should be developed for the design, construction, operation, and
abandonment of sediment ponds for maximum removal of suspended solids.
3. Methods should be developed for reducing suspended solids discharges from
surface mines to less than 30 milligrams per liter.
k. A manual should be developed in the form of guidelines for sediment and
erosion control planning and implementation. These guidelines must be designed
to cover all phases of the coal surface mining operation (i.e., before, during,
and after mining).
5. A mine road manual should be developed for use by surface mine operators
and State and Federal Agencies. Erosion, water control, and dust control should
be covered in detail.
6. The block-cut, head-of-hollow fill, and mountain-top removal methods and
techniques of contour mining should be evaluated, designed, and ultimately
demonstrated in steep, mountainous terrain. Designs should be prepared for
single and multiple seam applications. The demonstrations must show that
these mining systems will secure rapid achievement of reclamation require-
ments and provide maximum, safe, economic coal recovery in an environmentally
safe manner.
7. A Blasting Manual should be developed for use by industry and enforcement
agencies. Stress should be placed on how to keep vibration levels and air
blast pressures well below accepted safe criteria. Also, methods that can be
used to control noise should be listed.
8. Investigations should be conducted on the effect of continued vibrations
from blasting on structures that are near quarries.
9. Additional guidelines need to be developed for sampling and analysis of
overburden material and associated coals for trace elements and noxious
strata. Samples are extremely sensitive, and the source and manner of their
collection, handling, storage, and treatment, as well as the techniques of
analysis, need to be developed and described. This information can be used
to predict possible future problems.
210
-------
10. Methods for easily identifying the various strata in the overburden
are needed so that the equipment operator can segregate them during mining.
11. Techniques for analyzing strip mine spoil to determine required soil
amendments for vegetative establishment are needed. Standard agricultural
procedures for cropland are often not adaptable to spoil material (i.e., use
of lime).
12. Revegetation studies should be conducted to develop new or improved
methods for strip mine reclamation. Questions to be answered include:
a. What is the long-term benefit of immediate vegetative cover?
b. Will plants maintain themselves after initial fertilizer applications
are exhausted? What are optimum rates of fertilizer for establishing
cover?
c. What degree of erosion and sedimentation are controlled by various
cover densities?
d. What percentage of vegetative cover is adequate for the projected
land use?
e. Does natural plant succession take over following initial seeding and
planting?
f. What are the function and importance of soil microorganisms and soil
fauna in the development of soil and plant growth?
g. How long does the neutralizing action of limestone remain effective
and how often is reliming required?
h. Why does poor vegetative cover occur on the lower portion of out-
slopes even when seed and soil amendments are applied?
i. How does exposed gray and black shale affect revegetation efforts?
j. Does a complete vegetative cover hasten the development of a soil
profile? How long does it take? Is it permanent?
k. Can revised mining practices help in revegetation efforts?
1. What are the physical and microbiological beneficial effects of
using mulches as spoil amendments?
m. Is it feasible to use sewage sludge and compost to increase the
organic matter in spoil material? Will the use of sewage sludge
cause health hazards or heavy metals problems?
211
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n. Can power-plant fly ash be used as' a soil conditioner on western
strip-mined areas? If the proposed expansion of mine mouth electric
generating plants become a reality, fly ash will become available
in large quantities.
o. What part can native species play in permanently vegetating arid
and semiarid lands?
p. Why has there been little success with direct-seeding of desirable
tree and shrub species even on very favorable sites?
q. What plants are tolerant of toxic elements in the spoil?
r. What guidelines can be developed for establishing vegetative cover by
seeding throughout the summer months as well as spring and fall?
Various annuals and perennial species should be investigated for pro-
viding quick cover in the summer.
13. Current predictive models should be updated so that alternatives can be
studied before mining, thus minimizing environmental damages and still obtaining
maximum recovery at reasonable cost.
lU. Guidelines need to be developed for irrigation that will have widespread
applicability in coal mine spoil reclamation. An irrigation system designed
especially for this purpose should be constructed.
15- Water harvesting is a technique used to insure sufficient water for sus-
tained vegetation in areas where the annual precipitation is small. This
method of increasing the quantity of water available to plants should be
demonstrated under semi-arid conditions in the West.
l6. Reclamation needs to be demonstrated in the western United States. The
problem of reclamation of mine spoils in the West is composed of five main
dependent variables:
a. Soil moisture availability
b. Erosion
c. Pollution potential (surface and subsurface)
d. Chemical environment in the root zone (i.e., nutrient availability,
substances toxic to plants, etc.)
e. Type of vegetation
The purpose of the demonstration would be to show how each of the five variables
is affected when independent variables such as slope, spoil surface manipula-
tioi, fertilization, etc., are manipulated. This project could be used to study
the effects of surface manipulation on germination, seedling emergence and
vegetation growth concurrently.
212
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IT. Methods should "be developed and demonstrated to provide an artificial
aquifer to replace the one removed during the coal mining in western States.
In some areas, the coal seam itself is the groundwater aquifer. The results
of aquifer disruption could be many, but they depend upon the particular
geologic conditions.
18. Methods should be evaluated for controlling alkaline, saline, and other
high-salt discharges to surface and subsurface water bodies from surface
mines.
19. Active surface mining systems should be evaluated and regional surface
mining systems should be developed to employ various combinations of available
surface mining and/or earth moving equipment in a manner that reschedules
overburden handling and reclamation activities into a single, combined
effort. Selected systems should be studied as to engineering/cost
feasibility and environmental impact. Those systems that are environmentally
sound and show a potential for increasing productivity safely and at
reasonable cost, should be demonstrated in the field.
20. Overall manuals of practice should be developed for surface mining for
use by operators and regulatory agencies.
21. There is very little reliable information available on the cost of the
various phases involved in coal surface mining. An economic analysis of the
life cycle of coal surface mines located in eastern, central, and western
areas of the United States is needed.
22. Socioeconomic studies are needed to determine the impact of surface
mining on individuals, communities, and land use. Anticipated impacts can
be integrated in mining planning within the constraints of involved en-
vironmental conditions.
23. The effect of disposing of large volumes of waste residues from power
plants, gasification plants, etc. in surface mines should be evaluated..
2k. An information storage and retrieval system should be developed. This
system should be designed to collect, abstract, store, and retrieve data and
information concerning coal surface mining. Retrieval centers should be
established in the eastern, central, and western areas of the United States.
213
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SECTION XII
GLOSSARY
INTRODUCTION
Some of the terms defined here are not used in the text. However, the terms
will be useful to those interested in this and other publications in the field
of coal surface mining.
Abandoned • An operation that is not producing any mineral and will not
continue or resume.
Abatement (Mine Drainage Usage) • The lessening of pollution effects of mine
drainage.
Access Road * Any haul road or other road that is constructed, improved,
maintained, or used by the operator and that ends at the pit or bench and is
located within the area of land affected.
Acid Forming Materials • Overburden or other substances that were removed
or exposed in the mining process and that will, when acted upon by water and
air, cause acids to form.
Acid Mine Drainage • Any acidic water draining or flowing on, or having
drained or flowed off, any area of land affected by mining.
Acid Soil • A soil that is deficient in available bases, particularly
calcium, and gives an acid reaction when tested by standard methods; i.e., a .
pH below 7.0.
Active Surface Mine Operation • An operation where land is being disturbed
or mineral is being removed.
Aeration • The act of exposing to air, such as, to mix or charge with air.
Aerobic • Able to live and grow only if free oxygen is present.
Alkaline • Having the qualities of a base; i.e., a pH above 7.0.
Analysis • Proximate Analysis: Analysis of coal to determine (on a percent-
age basis) how much moisture, volatile matter, fixed carbon and ash the sample
contains; usually the coal's heat value is also established.
Ultimate Analysis: The chemical analysis of coal to determine the
amounts of carbon, hydrogen, sulfur, nitrogen, oxygen and ash are in the sample.
-------
Angle of Repose • The maximum angle that the inclined surface of a pile of
loosely divided material can make with the horizontal, (approximately Sjo).
Annual Plant (annuals) • A plant that completes its life cycle and dies in
1 year or less .
Aquifer • A formation, group of formations, or part of a formation that is
water "bearing.
Area of Land Affected • The area of land from which overburden is to lie or
has been removed and upon which the overburden is to be or has been deposited.
Included are all lands affected by the construction of new roads or the im-
provement or use of existing roads other than public roads, to gain access and
to haul the mineral.
Area Surface Mining • A type of strip mining that is generally practiced on
gently rolling to relatively flat terrain; it is commonly found in the midwest
and far west.
Ash • The incombustible material that remains after coal has been burned.
Auger Mining • Mining of coal from an exposed vertical coal face by means of a
mechanically driven boring machine that employs an auger to cut and bring the
coal out of the bore hole.
Backfill • Placing spoil material back into an excavation or pit and returning
the area to a pre determined configuration.
Barrier • Portions of the mineral and/or overburden that are left in place
during mining. Function is to provide a natural seal along the outcrop.
Bench • The ledge, shelf, table, or terraces formed in the contour method of
strip mining.
British Thermal Unit (BTU) • The quantity of heat required to raise the
temperature of 1 pound of water one degree Fahrenheit.
Bulldozer • A tracked vehicle equipped with a blade.
Calcareous • A material containing calcium or calcium carbonate, usually found
in limestone or in spoil impregnated with lime.
Clinker • Sometimes referred to as "scoria", a term commonly used to identify
the material overlying a burned coal bed. Clinkers usually consist of baked
clay, shale, or sandstone. They weather to gravel-sized particles that are
generally red in color and are used extensively as a road-surfacing
material. Clinkers are similar to red dog.
Compost • Relatively stable decomposed organic-material.
Composting • A controlled aerobic process of degrading organic matter by
microorganisms.
215
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Contour Surface Mining • A type of strip mining that is practiced in areas of
hilly topography. The coal seam outcrops or approaches the surface at approxi-
mately the same elevation along the hillside. Entrance is made to the seam
with overburden commonly cast down slope below the operating bench.
Cool Season Plant • A plant that makes its major growth during the cool season
of the year, usually in the spring but in some localities in the winter.
Core Drilling • The process by which a cylindrical sample of rock and other
strata is obtained through the use of a hollow drilling bit that cuts and
retains a section of the rock or other strata penetrated.
Cut • Longitudinal excavation made by a strip-mining machine to remove over-
burden in a single progressive line from one side or end of the property being
mined to the other side or end.
Deep Mine • An underground mine.
Detrimental Environmental Impact • Any substance, procedure or energy produced
by any operation that adversely affects any form of life or creates a condition
offensive to the aesthetic sense.
Dissolved Solids • The difference between the total and suspended solids in
water.
Diversion • Channel constructed across a slope to intercept surface runoff;
changing the course of all or part of a stream or runoff.
Dragline • A type of excavating equipment which casts a rope-hung bucket a
considerable distance and digs by pulling the bucket toward itself.
Drainage Plan • The proposed methods of collection, treatment, and discharge
of all waters within the affected drainage area as defined in the premining
plan.
Ecology • The science that deals with the interrelationships of organisms to
one another and to the environment.
Ecosystem • A total organic community in a defined area or time frame.
Environment • The sum total of all the external conditions that may act upon
an organism or community to influence its development or existence.
Erosion • The wearing away of land surfaces by natural, physical, or chemical
processes.
Evapo-transpiration • A collective term meaning the loss of water to the
atmosphere from both evaporation and transpiration by vegetation..
Fertility • The quality of a soil that enables it to provide nutrients in
adequate amounts and in proper balance for the growth of specified plants when
other growth factors, such as light, moisture, temperature, and the physical
condition of the soil are favorable. •'-
216
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Fill Bench. • That portion of a bench, formed by spoil that has been deposited
on the original slope (contour mining},
Filter Strip • Strip of undisturbed vegetation that regards the flow of runoff
water, causing deposition of transported material and therby reducing sedimen-
tation of receiving streams.
Final Cut • Last line or cut of excavation made on a specific property or
area.
Flume • An open channel or conduit on a prepared grade.
Fly Ash • All solids, ash, cinders, dust, soot, or other partially incinerated
matter that is carried in or removed from a gas stream. Fly ash is usually
associated with electric generating plants.
Forb « A palatable, broad leaf, flowering herb whose stem above ground does
not become woody and persistent.
Gasification • The process of converting a solid or liquid fuel into a gaseous
fuel.
Germination • Sprouting; beginning of growth.
Gob • Waste coal, rock pyrites, slate or other unmerchantable material of
relatively large size that is extracted during underground mining and deposited
either underground or on the surface in gob piles. The term is mistakenly,
often used interchangeably with refuse.
Grading • The shaping of the area of land affected by mining with earth moving
equipment.
Groundwater • Water present in the saturated zone of an aquifer.
Heterogeneous • Unlike in character or quality, structure or composition; not
homogeneous.
Highwall • The vertical wall adjacent to unmined land.
Homogeneous • Consisting throughout of identical or closely similar material
whose proportions and properties do not vary.
Hot • Refers to material in the overburden, refuse, or gob piles that is highly
acid producing or difficult to revegetate because of its acid nature.
Hydrology • The study of water and its behavior from both a physical and
chemical standpoint.
Hydroseedinft • Dissemination of seed, mulch and soil amendments, hydraulically
in a water medium.
^filtration • The act or process of the movement of water into soil.
217
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Intermittent Stream • A stream or portion of a stream that flows only in
direct response to precipitation. It receives.little or no water from springs
and is dry for a large part of the year.
Leachate • Liquid that has percolated through a medium and has extracted
dissolved or suspended materials from it.
Leaching • The solution of the soluble fraction of a material by flowing
water.
Legume • A plant member of the legume family, leguminossae, which is one of
the most important and widely distributed plant families. The fruit is a pod
that opens along two sutures when ripe. Legumes include food and forage
species such as peas, beans, peanuts, clovers, alfalfas, sweet clovers,
lespedezas, vetches, and kudzu. Practically all legumes are nitrogen-fixing
plants when inoculated properly.
Manure • Primarily the excreta of animals; may contain some spilled feed or
bedding.
Method of Operation • The manner by which the cut or open pit is made, the
overburden is placed or handled, water is controlled, and other acts are
performed by the operator in the process of uncovering and removing the
mineral. The method of operation affects the reclamation of the area of land
affected.
mg/1 • Abbreviation for milligrams per liter, which is a weight volume ratio
commonly used in water quality analysis. It expresses the weight in milligrams
of a substance occurring in one liter of liquid.
Microorganism • Any living thing that is microscopic or submicroscopic in
size.
Mine Drainage • Any water discharged from a mine-affected area, including
runoff, seepage, and underground mine water.
Mulching • The addition of materials (usually organic) to the land surface to
curtail erosion or retain soil moisture.
Natural Drainway • Any water course that has a clearly defined channel,
including intermittent streams.
Neutralization • When associated with coal mining, neutralization is the
addition of an alkaline material such as lime or limestone to an acid material
to raise the pH and overcome an acid condition.
Operation • All of the premises, facilities, railroad loops, roads, and equip-
ment used in the process of producing and removing coal from a designated strip
mine area or prospecting for the purpose of determining the location, quality,
or quantity of a natural coal deposit.
218
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Organic Matter • The fraction of the soil that includes plant and animal
residues at various stages of decomposition, cells and tissues of soil
organisms, and substances synthesized by the soil population.
Organism • Any living thing.
Orphan Lands • Disturbed surfaces resulting from, surface mines that vere
inadequately reclaimed by the operator and for which he no longer has any fixed
responsibility. Usually refers to lands mined previous to the passage of
comprehensive reclamation lavs.
Outcrop • To come to or be exposed on the surface. That area of land where the
coal seam is naturally exposed or near the surface.
Out slope • The face of the fill spoil extending downslope from the outer point
of the bench to the toe of the fill section.
Overburden • The earth, rock, and other minerals lying in the natural state
above coal deposits before excavation.
Percolation • A term that refers to the downward movement of water through
soil,
pj| • A numerical measure of the hydrogen ion concentration. It is used to
indicate acidity and alkalinity. The neutral point is pH 7-0; pH values below
7.0 indicate acid conditions and those above 7.0 indicate alkaline conditions.
Pit (Strip Pit) • That part of the operation from which coal is being or has
been removed from its natural state.
Pollution • The entrance into any media of any material or energy that affects
any form of life in a deleterious fashion or creation of a condition in the
environment offensive to the aesthetic sense.
Pre-Law • A term used to refer to strip mine operations conducted previous to
the passage of a States' first reclamation act.
Propsecting; • Means the removal of overburden, core drilling, construction of
roads, or any other disturbance of the surface for the purpose of determining
the location, quantity, or quality of the natural coal deposit.
Pyrite • A yellowish mineral, iron disulfide, FeS2, generally metallic
appearing; also known as "fool's gold".
Reclamation • Backfilling, grading,highwall reduction, top-soiling, planting,
revegetation and other work to restore an area of land affected by strip
mining.
Red Dog • Solid waste that has burned and is the result of coal mining or
processing. The material is red in color and is often used for road surfacing.
Refuse • Solid waste from a coal preparation or cleaning plant.
219
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Regrading • The movement of earth.over a, surface or depression to change the
shape of the land surface.
Rider Seam • A stray coal seam usually above and divided from the main coal
bed or rock, shale, or other strata material. The rider seam is generally thin
and. seldom merchantable.
Riparian Rights • Rights of the landowner to vater on or bordering his
property; included is his right to prevent upstream water from being diverted
or misused.
Riprap • Broken rock, cobbles, or boulders placed on earth surfaces such as
the face of a dam, bank of a stream or drainage channels for protection
against the action of water to prevent erosion.
Runoff • That portion of precipitation that drains from an area as surface
flow.
Scarification • Loosening or stirring the surface soil without turning it
over, as with a disc.
Scoria • See Clinker.
Sediment • Solid material, both mineral and organic, that is in suspension, is
being transported, or has been moved from the site of origin by air, water,
gravity or ice and has come to rest on the earth's surface either above or
below sea level.
Sedimentation • The depositing of sediment.
Seedbed • The soil prepared by natural or artificial means to promote the
germination of seed and the growth of seedlings.
Seepage • Movement of water through soil without forming definite channels.
Shovel • An excavating and loading machine consisting of a digging bucket
at the end of an arm suspended from a boom. When digging the bucket moves
forward and upward. The machine usually excavates at the level at which it
stands.
Siltation • Small sized sedimentary particles of soil carried by surface
runoff into lower levels. Siltation is known as sedimentation.
Slip or Slide • A mass of spoil material that moves downward and outward to a
lower elevation because of the force of gravity. Slipping is generally caused
by overloading of the downslope, freezing and thawing, or saturation of the
fill.
Slope • The deviation of a surface from the horizontal expressed as a percent-
age , by a ratio, or in degrees.
220
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Slurry • Refuse separated from the coal in the cleaning process. Slurry is
of relatively small size, and is readily pumpable in the washing plant
effluent. Slurry is also a pulverized coal-liquid mixture transported "by
pipeline.
Spil • The unconsolidated natural surface material present above bedrock; it
is either residual in origin (formed by the in-place veathering of bedrock) or
it has been transported by wind, water, or gravity.
Spoil • All overburden material removed, disturbed, or displaced from over the
coal by excavating equipment, blasting, augering, or any other means. Spoil
is the soil and rock that has been removed from its original location.
Stabilize • To settle or fix in place. Stabilization is accomplished on spoil
by mechanical or vegetative methods that include planting of trees, shrubs,
vines, grasses, and legumes, or by mechanical compaction or aging.
Strike-Off • Removing the peak of a spoil ridge by mechanical means to provide
a truncated condition.
Strip Mining • Refers to a procedure of mining that entails the complete
removal.of all material from over the coal to be mined in a series of rows or
strips; also referred to as open-cut, open^pit or surface mining.
Subsidence • The settling or sinking of the land surface because of drainage
or underground mine roof falls.
Subsoil • That part of the soil beneath the topsoil; it usually does not have
an appreciable organic content.
Sulfuric Materials • Mineral matter or compounds containing sulfur that can be
oxidized in the presence of moisture to form acid, such as pyrite or marcasite.
r
Surface Mining • Used interchangeably with strip mining or open-cut mining;
the mining of coal after removal of the overburden above the deposit.
Surface Water • Water, from whatever source,that is flowing on the surface of
the ground.
Suspended Solids • Sediment which is in suspension in water but which will
physically settle out under quiescent conditions (as differentiated from
dissolved material).
Sweet • Refers to the lime content or calcareous condition of spoil that
indicates a neutral or slightly alkaline material capable of supporting certain
calcium-demanding plants; the term "sweet" indicates a pH of 7.0 or above.
Tacking • The process of binding mulch fibers together by the addition of a
sprayed chemical compound.
221
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Tailings • Waste material derived when the raw mineral or ore is processed
to improve its quality or literate other components. Tailings are usually
associated with hard rock mining.
Terracing • The act of creating horizontal or near horizontal "benches.
Topographic Map • A map indicating surface elevations and slopes.
Topsoil • The unconsolidated earthy material that exists in its natural state
above the rock strata and that is or can be made favorable to the growth of
desirable vegetation.
Transpiration • The normal loss of water vapor to the atmosphere from plants.
Underground Mining (Deep Mining) • Removal of the coal being mined without the
disturbance of the surface (as distinguished from surface mining).
Warm Season Plant • A plant that completes most of its growth during the
warm portion of the year, generally late spring and summer.
Water Bar • Any device or structure placed in or upon a haul or access road
for the purpose of channeling or diverting the flow of water off the road.
Watersheds • Total land area above a given point on a stream or waterway that
contributes runoff to that point.
Water Table • The upper limit of the part of the soil or underlying rock
material that is wholly saturated with water; the locus of points in soil water
at which the hydraulic pressure is equal to atmospheric pressure.
Perched Water • A water table, usually of limited area, maintained above the
normal free-water elevation by the presence of an intervening, relatively
impervious stratum.
Weathering • Action of the weather elements in altering the color, texture,
composition, or form of exposed objects.
Wheel Excavator • A machine for excavating unconsolidated material. It con-
sists of a digging wheel, rotating on a horizontal axle and carrying large
buckets on its rim.
222
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ro
ro
u>
APPENDIX A— 1 — amm or STATE sautes tonne AN> HUD un RECUKATUM LAHS i* EFFECT JBUE i, 1974 *
STATE
ALABAMA
ARKANSAS
COLORADO
FLORIDA
TITLE
OR
CODE CITATION
The Alabeu Surface
Minim Act of IM9.
Effective Oct.l, 1970.
The Arkansas Open Cut
Land Beclaeatlon Act
of 1971. Effective
July 1, 1971.
The Colorado Open Cut
Lend Reclamation »ct
of 1969. AwndM
effective July 1, 1972.
Chapter 92 Article 32
Colorado Revised
Statutes, as amended.
Effective July 1, 1969.
Chapter 71-105, Florida
Statutes. Effective
July 1, 1971.
MINERALS COVERED
All ninerals except line-
stone, marble and dolemite.
All Minerals
Coal
Hi IMF ills C^tfier than
Coal
Solid Minerals
i irrasE AMD/OR n
APPLICATION
Permit application*
mu*t be filed with
the Department- of
Industrial Relations
and be accompanied
by a plan of reel**
•ation.
Permit applications
nu*t be filed with
Arkansas Pollution
Control Cant Mien
and be accompanied
by a reclamation
plan.
Permit applications
Mi*t be filed with
the Land Reclamation
Doard. A reclamation
plan is required.
FEE
Filing fee-
$250. $50
fee for
amended
permit.
$25 to
$500 de-
pend Lug
upon the
number of
acre* to
be mined.
$50 plus
$15 for
each acre
to be
affected.
*Source: United States Department of Interior,
Bureau of Mines, Division of Environment,
Washington, D.C.
nrra
PENALTY
Mining without
a permit- n>t
lets than $500
nor nore than
$5000 and re*
quirenent thai
the affected
land be reel lin-
ed. Willful
misrepresents-
tlon of facts
on permit appll-
cation-aot les*
than $100 nor
•ore than $500
for each offense.
Surface Mining
without a permlt*-
• fine of not lei*
than $500 nor
•ore than $1000
for each day the
violation contin-
ue!.
The Act provides
no penalties but
contain adminis-
trative procedur-
es for dealing
vtth violations.
Crfw£a» 1 flaw.) ft.f
F orjre i cure oz
performance
bond.
BOND
REQUIREMEBTS
$150 for each acre
covered by the
penalt.
$500 for each acre
or portion to be
affected.
the bond penalty
shall be in such
amount as la
deemed necessary
to insure the
operator's per*
foraance.
Ht*h fVuaukl * ml AMAha*
HMr LOmni SMI Oner
of Hines may
require an oper-
ator to post a
performance bond
conditioned upon
the faithful per-
fomance of stabi-
lization work.
RECLAMATION REQUIREMENTS
Reduce peaks and ridge* Co • wldtH of
15-feet at the topi cover face of toxie
Material! divert water to reduce silta-
tion. erosion or damage to streams and
natural water courses i plant trees or
direct-seed the affected l«nd| revegeta-
te haulage rosds and land used to dispose
of refuaef and construct fire lan*e or
access roads in areas to be reforested.
Red .nation to be completed within 3-yrs.
of expiration of pen.it period.
Grade peaks and ridges to a rolling topogr
phy| construct earth da»s| In areas to be
reforested, construct fire lanes or acces
roads at least 10-feet Wide) strike peaks
and ridges to a niniinua of 20-feet at the
top on all land to be 'seeded for pasturef
cover exposed acid foming material t and
dispose of refuse so as to control erosion
or damage to streams or natural water
courses. Reel ana tion to be completed prt
to the expiration of 2*yrs. after termina
tion of permit.
Grade ridges and peaks to a width of 15-f
at the topi where prsctlal, construct ear
dans in final cuts to impound water* cover
acid forming material to protect drainage
system from pollution} sad dispose of all
refuse so as to control stream pollution*
and divert water to control viltatlon.
erosion, or other damage to streams and
natural water courses. The Act further
contains specific requirements for reclaim
ing disturbed areas for various uses in-
cluding forest, range, agricultural or
horticultural crops, homesites, recreation
al and industrial.
TOtA f^ABMat *>*t AHA*! AeT Ml ••*»•) 1 at mm fu IMSJSB1 a jl tTA
**>B K»oiRRii.ssiwier or nines is empower ea co
examine all ore mills, sampling works.
smelters, metallurgical plants, rock and
stone quarries, clay pits, tunnels, sand.
and gravel pit excavations and plant and
nines, except coal mines, to determine
the method of surface stabilization used
including vegetation to prevent landslides
floods or erosion. Whenever possible, the
type of reclamation to be performed is
determined through agreement between the
Commissioner and the operator.
The Act imposes a severence tax on the
extraction of certain solid minerals. A
mine operator may obtain s refund of up
to 60 percent of the tax Imposed by the
Act for developing and instituting J
reclamation and restoration program.
PBHALTf FOB
GKFEXTUBE
OF BOND
Yes
Yes
Yes
Vtkat
yes
BBe*l Ale*
SERIAL
OF NESf PERMIT
Yes
Ho
Yes
REMARKS
Solid minerals
hlch are ex-
tracted by the
owner of the
Ite of sever-
nce for the
mprovemcnt of
uch site, or
olid minerals
pon which •
ales ti>x ts
•Id to the
tate or sold
o governmental
agencies in the
tate, including
Uies and
ountles, shall
* exempt from
ie subject tax.
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-p-
GEORGIA
IDAHO
ILLINOIS
INDIANA*
IOWA
Georgia Surface
Mining Act of 1968,
Effective Jan. 1,1969.
The Idaho* Surface
Mining Act. Effect-
ive Hay 31, 1971.
The Illinois Surface-
Mined Land Conservation
Act. Effective
September 17, 1971.
Chapter 344, Acts of
1967, Indiana Statutes.
Effective Jan. 1, 1968.
An Act Relating to
Surface Mining.
Effective January 1,1968
All Minerals
All Minerals
All Minerals
Coal, clay and
Shale.
All Minerals
A license must be
obtained from the
Surface Mined Land
Use £"oard« A
mined land use
plan is required.
SlOO to $500
annually de-
pending upon
the number of
mining employ-
ees employed.
No permit is required, but persons
desiring to conduct exploration
and surface raining operations must
submit and have approved, by the
Board of Land Commissioners, a plan
of reclamation.
Applications for
permits must be
filed with the
Department of
Mines and Miner-
als for all
operations
exceeding 10-ft,
in depth or
affecting more
than ID-acres
during the per-
mit year. A
reclamation plan
is required.
Applications for
permits must be
filed with the
Department of
Natural Resources.
A reclamation
plan is required.
Permit applications
must be filed with
the Department of
''lines and Minerals.
$50 plus $25
for every
acre to be
affected.
$50 plus $30
for each acre
to be affect-
ed.
License-$50.
$10 renewal
The Act pro-
vides Admini-
strative
remedies
(restraining
orders, temp-
orary and
permanent in-
junctions) for
violation of
its provisions.
Any violation
of the recla-
mation plan
subjects .the
operator to a
civil penalty,
the amount of
which is not
specified.
Surface HinlnB
without a permit-
not less than $50
nor more than
$1000. Each day'i
violation is
deeoed a separate
offense .
Hot less than
$1000 nor more
than $5000.
$50 to $500 or
Imprisonment
not to exceed
30-days or both.
Not less than $100
nor more than $500
ler acre of land
affected.
Hot to Exceed $500
'or any acre of
land affected.
$600 to $1000
for each acre
to be affected
Including slurry
and gob disposal
areas .
Hie greater of
$5000 or $600
miltlpiied by
the number of
acres for
which the permit is
Issued.
An amount equal
to the estimated
cost or rehabili-
tating each site
*f f Bf*^B«l
•xiecceo.
Grade and backfill peaks, ridges, and
valleys to a rolling topographyi cover
exposed toxic ores or mineral solids
of supporting a permanent plant covert
and establish permanent ground cover on
affected lands the first growing season
following grading.
Level ridges of overburden to a minimum
of 10-feet at the top; level peaks of
overburden to a minimum of 15-feet at
the topt prepare overburden piles to
control erosion} minimize siltation of
lakes and streams as a result of water
run**off from affected landsf cross-ditch
abandoned roads to avoid erosion gulliesf
plug exploration drill holes; when
possible, top affected land with over-
burden conducive to erosion control and
establishment of vegetative growth!
prepare tailings ponds so as not to
constitute a hazard to human or animal
life; and complete reclamation within
1-year after surface mining operations
permanently cease or are abandoned.
Grade affected land to a tolling topo-
graphy with slopes having no more than a
15% grade, except land reclaimed for
forest plantation, recreational or
wildlife, the final cut spoil, the box
cut spoil, and the outside slopes of
all overburden deposition areas, the
grade shall not exceed 30*i impound
runoff water to reduce soil erosion.
damage to unmined lands, and pollution
of streams and waters; cover exposed
acid forming material with not less
than 4-6 feet of water or other
materials capable of supporting plant
and animal life;, confine slurry In
depressed or mined areas; remove and
grade all haulage roads and drainage
ditches; and plant trees, shrubs,
grasses and legumes. All reclamation
except slurry and gob areas in active
use shall be completed prior to the
expiration of 3-years after termina-
tion of the permit year.
Grading to reduce peaks and ridges to
a rolling, sloping or terraced topo-
graphy; construct earth dans in final
cuts to impound water; bury all metal.
lumber, or other debris or refuse
resulting from mining; and revegetate
affected areas as soon as practicable
after initiation of mining operations.
Grade irregular spoil banks to reduce
peaks and ridges to a rolling topogra-
phy suitable for establishing vegeta-
tion by striking off ridges and peaks
other spoil banks to slopes having a
naximum of 1-foot vertical rise for
each 3-feet horizontal distance, ex-
cept where the original topography ex-
ceeds these stipulations, the spoil
bank shall be graded to blend with
surrounding terrain; and cover acid
forming naterial with at least 2-fe«t
of earth or spoil material. Ooerators
shall rehabilitate affected areas with-
in 24-months after mining is completed.
Y«s
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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KANSAS
KENTUCKY*
MAINE
MARYLAND*
MICHIGAN
The Kanea* Mlned-Land
Conservation and Recla-
mation Act. Effective
July 1, 1968.
Chapter 350, Kentucky
Revised Statutes.
Effective June 16, 1966.
Mining-Conservation
and Rehabilitation of
Land, Effective
June 1( 1971.
' Maryland Strip Mining
Law. Effective July 1,
1971.
Mine Reclamation Act.
Act No. 92 of the
Public Act* of 1970,
as amended by Act
No. 123 of the htblic
Act* of 1972. Effect-
ive March 29, 1973.
Coal
All Minerals
All Minerals except
and, gravel and
orrow operations.
Coal
All Minerals except
Clay, gravel, atari,
peat or sand.
Pemit application*
Huat be filed with
the Klned Land Con-
servation and ftecla-
matlon Board. A re-
clamation plan I*
required.
Permit application*
must be filed with
the Division of Re*
clamation. A re*
clanuttlon Flan, is
required.
Permission to con-
duct surface mining
is contingent upon
approval of the op-
erators mining plan.
A license and per-
mit oust be obtained
from the Bureau of
Mines. A reclamation
plan Is required.
$50
Coal- $50
plus $25
for each
acre to
be affect-
ed. License
fee for
other min-
erals -$100
per year.
Permit fee
for other
mineral »-$ 2 5
per year.
$50 plu*
$25 for
each acre
to be
affected
not to
exceed a
total of
$500.
License.
$100 plus
$10 for
each re-
newal.
Not to ex-
ceed $250.
Each day
violation
continue*
constitute*
* separate
offense.
A fine of not
leas than $100
nor more than
$1000 for **ch
day the viola*
tlon continue*.
Willful .viol*.
tion-not lea*
than $500 nor
more than $5000
for each day
violation con-
tinue*.
Hot more than
$100 for each
day a violation
continues.
Failure to ob-
tain a license-
not less than
$5000 nor more
than $10,000 or
imprisonment not
to exceed 6 mon-
ths, or both.
Failure to obtain
a permit-not less
than $500 nor
more than $5000.
Failure to back-
fill prospected
areas-not less
than $200 nor
more than $500.
Not leaa than S200
nor more than $5OO
per acre with a
$2000 minimum.
Hot less than $100
nor more than $500
per acre with a
$2000 minimum.
An amount to be
determined by
the Mining Com-
mission of not
less than $100
nor more than
$1500 for each
•ere to be
affected.
$400 per acre
with a $3000
minimum. A
special recla-
mation fee of
$30 per acre of
land affected and
a revegetation
bond of not less
than $50 nor more
than $125 per
acre are also
required.
If there is
doubt as to
the operator's
financial abili-
ty to comply
with the rules
of the Act. he
may be required
Co post a per-
romanance bond
or other securi-
ty*
Grade each pit to a flat surface with
a width equal to at l*aat 602 of the
original pitt cover the face of coal
or other mineral* with non-acid bear-
Ing and non-toxic material* to a dis-
tance of at leait 2-feet above the
•earn being mined, or by a permanent
water lapoundmenti control flow of all
runoff water to reduce soil erosion.
damage to agricultural lands ( and
pollution of streams and water*! and
grade overburden to provide suitable
vegetative cover. Reclamation muat be
pursued as soon as possible after
mining begin* and completed within 12-
months after the permit has expired.
Complete backfilling not to exceed the
original contour with no depression* to
accumulate water is required of all land
affected by area mining. All hlghwall*
resulting from contour strip mining *hal
be reduced or backfilled, the *teepe*t
slope of the reduced or backfilled high-
wall end the outer slope of the fill
bench being no greater than 45 degrees
from the horizontal. The table portion
to be terraced with a slope not greater
than 10-degree*. The restored are* to
have a minimum depth of 4-feet of fill
over the pit floor. Revegetation shall
include pirating tree*, shrubs, grasses
legumes. Reel ana t ion to begin as soon
a* possible after strip mining begin*
and completed within 12-month* after
the permit ha* expired.
Varied-depending on planned future use
of reclaimed land. The intent of the
Commission I* to insure that 'an approv-
ed permanent vegetative cover I* estab-
lished where possible on affected lend.
and that the condition in which the land
i* left is not conducive to erosion or
pollution.
Grade spoil banks to reduce depressions
between peaks of spoil to a surface
which restore* the terrain to a
condition prescribed by the Director,
Bureau of 'Mines t if overburden deposits
are composed of materials which are
suitable for supporting vegetative grow-
th, it shall be graded *o a* to cover
the final pit| and »e»l-off, with a fill.
underground mining operations at the ba*e
of the final cut.
The Act authorizes the Chief of the
Geological Survey to conduct a con-
prehen*lve study and survey to deter.
mine the type of regulation needed to
protect the public Interest. Upon
completion of the survey, rules may
be promulgated govern ingi Sloping,
terracing or treatment of stockpiles
and ''tailings to prevent damage to
fish and wildlife, pollution of
water* or injury to persons or pro-
pertyj vegetation or treatment of
tailings basins and stockpiles where
natural vegetation is not expected
within S-year* and where research
reveal* vegetation can be accompli-
shed within practical limitation*)
and stabilization of the surface
overburden bank* of open pit* In
rock* and the entire bank of open
pit* in unconiolidated material.
Yes
Ye*
Yes
res
—
Y*S
Ye*
No
res
—
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MINNESOTA
MISSOURI
MONTANA
Mine land Reclamation
Act. Minnesota Statu-
tes 1971 CM mended
by lava 1973, Chapter
526). Effective
August I, 1973.
An Act Relating to the
Reclamation of Certain
HinLng Lands. Effective
September 28, 1971.
An Act Relating to the
Reclaiming or Restora-
tion of Lands Disturbed
by Open Pit or Surface
Hining. Effective
September 28, 1971.
The Montana Strip Hining
and Seel an* t Ion Act.
Effective March 16, 1973.
The Open Cut Mining Act.
Effective Harch 16. 1973.
Montana Hardrock Mining
Reel ana t ion Act. Effect-
ive September IS, 1971.
Metallic Minerals
Coal and h«rita«
Clay, limestone.
sand and gravel.
Coal, clay, phosphate
rock and uranium.
Bentonite, sand and
gravel.
Any ore. rock or sub-
tance other than oil.
as, bratonite, clay.
>oal» sand, gravel,
bosphate rock or
ranlum.
A permit to mine
must be obtained
from the Commis-
sioner of natural
Resources. A recla-
mation plan Is
required.
Permit applications
mutt be filed with
the Land Reel ante Ion
Commission. A recla-
mation plan le
required.
Permit applications
must be filed with
the Land Reclamation
Commission. A recla-
mation plan is req-
uired.
Permit applications
must be filed with
the Department of
State Lands. A rec-
lamation plan is re-
quired.
Applications for
contracts must be
made to the Board
of Land Commission-
ers if the planned
operation involves
removing 10,000
cubic yards or more
of product or over-
burden. A reclama-
tion plan is requir-
ed.
Exploration license
and- Development per-
mit must be obtained
from the State Board
of Land Commissioners.
A reclamation plan Is
required.
$50 plus
SI 7. 50 for
each acre
to be
affected.
$50 plus
$17.50 for
each acre
to be
affected.
$50 for
mining
wrmie.
$100 for
•respect-
ing permit.
$50
Explora-
tion
License.
$5.00.
Develop-
ment
permit
$25.
Failure to
comply with
the provi-
sions of the
Act -not more
than $1000
for each day
such failure
continues.
Hining without
a permit- $1000
per day for
each day the
violation con-
tinues.
Hining without
a permit-not
less than $50
nor more than
$1000. Each
day violation
continues is
deemed a sepa-
rate offense.
Violation of
provisions*
fine of not
less than
$100 nor more
than $1000.
Hillfull vio-
lation, not
less than $500
nor more than
$5000. Each
day violation
occurs consti-
tute* a sepa-
rate offense.
Mining without
a contract-
not less than
$500 nor more
than $1000.
Each day** vio-
lation is con-
sidered a sepa-
rate offense.
1
Violation of
Act-Not more
than $1000 or
6-months
imprisonment,
or both.
The Commissioner
determines whether
or not a bond may
be required.
Hot less than $300
for coal and $200
for barlte nor more
than $700 for coal
and $500 for barite
for each acre of
land affected, with
a $2000 minimum.
$500 for each acre
to be affected.
Not less than $200
nor more than $2500
per acre with a
$2000 minimum.
Not less than $200
nor more than $1000
per acre.
Hot more than $500
per acre.
The Commissioner of Natural Resources
shall conduct a comprehensive study and
survey to determine the extent to which
regulation is needed to protect the
public interest giving due consideration
to the environment, future land utiliza-
tion, protection of other natural resou-
rces and the future economic effects of
such regulations on mine operators and
landowners, the surrounding communities
and the State of Minnesota.
Grade peaks and ridges of overburden,
except where lakes are to be formed, to
a rolling topography t ravers able by farm
machinery. The slopes need not be re-
duced to less than the original grade
prior to mining, and the slope of over-
burden ridge resulting from a box cut
need not be reduced to less than 25-
degrees from the horizontal. Dispose
of all debris, material or substance
removed from the surface prior to
mining.
Grade peaks and ridges to a rolling topo-
graphy traversable by machines) construct
fire lanes or access roads through areas
to be reforested! strike peaks and ridges
of overburden to a minimum of 25-feet= at
the top on all land to be reforested) on
land to be used for crops, grade peaks
and ridges of overburden so that the area
can be traversed by -farm machinery t con-
struct lake* from mined pits and dams in
final cut*} cover exposed face of miner-
al seam with not less than 4-feet of
earth that will support plant llfei and
sow, set-out or plant upon the affected
land plants, cutting* of trees, shrubs.
grasses or legumes appropriate3- to the
designated type of reclamation.
Bury under adequate fill all toxic materi-
al «l seal off breakthrough of water creat-
ing a hazard j impound, drain or treat run-
off water BO as to reduce coll erosion*.
damage to grazing and agricultural lands.
and pollution .of surface and subsurface
waters f and remove and bury all refuse
resulting from the operation. All highwalls
must be reduced, the steepest clop* of
which shall be no greater than 20-degrees
from the horizontal. Backfilled, graded
and topsoiled areas shall be prepared and
planted with legumes, grasses, shrub*, and
trees. Reclamation to begin as soon as
possible after beginning strip mining.
Reclamation oust be carried out in accord-
•nce^with the approved reclamation plan
which requires that the land be reclaimed
for specified uses including forest.
pasture* orchard*, cropland, residence.
recreation, industry, or wildlife habitat.
Reclamation requirements include! establish-
ment of vegetative covert control water
drainage} grading | removal or burial metal or
waste} and revegetation of affected area.
Reclamation of the affected land must be
performed in accordance with tin approved
reclamation plan which contains measures
fort surface gradient restoration suitable
for proposed lend usei revegetation or
other surface treatment} public health and
safety} disposal of mining debris} divert-
ing water to -prevent pollution or erosion}
reclamation of stream channels and bank* to
control erosion, all tat ion, and pollution.
...
Yes
res
Yes
Yes
Tes
...
Yes
Yes
Yes
Yes
Y«*
Public liabili-
ty insurance In
an adquate amount
to provide per-
sonal Injury and
property damage
protection i* als
required.
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HEW MEXICO
NORTH CAROLINA*
NOBTH DAKOTA
OHIO
Coal Surface Mining
^f Bffmrt* t «»
EL* HI rnCElVC
February 29, 1972.
The Mining Act of
1971. Effective
June 11, 1972.
Ch.pter 38-14 North
Dakota Century Code,
as amended. Effect-
ive July 1, 1973.
Title IS, Ohio Revised
Code. Chapter 1513 as
amended-Reclamation of
Strip Mined Land.
Effective April 10, 1972.
Coal
All Minerals
All Minerals
Coal
Application for
permit must be
filed with the
Coal Surface
Mining Commis-
sion* Mining
plane must
accompany
permit appli-
cations.
Application for
a permit must be
filed with the
Department of
Natural and
Economic Res-
ources. A
reel ana ti on
plan is required.
Applications for
permits must be
filed with the
Public Service
Comnission for
all planned
operations ex-
ceeding 10-feet
in depth. A
reclamation plan
is required.
Applications for
licenses must be
filed with the
Division of Rec-
lamation. A rec-
lamation plan is
required.
$5O appli-
cation fee.
$10 initial
acreage fee.
Annual fee
of $20 per
acre for
each acre
affected-
during the
preceding
year
No fee is
required.
Permit
will be
granted if
the recla-
mation plan
is approved.
Up to ten
acres-$25
plus $10
tines the
number of
acres to
be affect-
ed between
two and
ten; elev-
en to fif-
ty acres -
$100 plus
$10 times
the number
of acres
between
eleven and
fifty.
More than
fifty acres
$275 plus
$10 times
the number
of acres in
excess of
fifty acres.
$100 plus
$30 for each
acre to be
mined.
$1000 for each
continues.
Willful vio-
lation $100
to $1000
fine. Each
day consti-
tutes a sepa-
rate viola-
tion.
Mining with-
out a permit-
fine of not
less than 950
nor more than
$1000. Each
day violation
continues con-
stitutes a
separate off-
ense.
Mining without
a permit -$5000
plus $1000 per
acre of land
affected. Ex-
ceed limits of
license-$lOOO
per acre of
land affected
that is not
under license.
Willful mis.
represeRtation-
$100 to $1000
or 6 months.
Violation of
any other pro-
vis ion-$l 00 to
$5000 or 6
aionths in pri-
son, or both.
The Surface Coal
may require an
operator to file
a bond in an
amount sufficient
to insure compli-
ance.
$2,500 to $25,000
depending upon the
number of acres to
be affected.
$500 for each
acre to be af-
fected.
Sufficient to cover
the cost of reclam-
than $5000,
Grade to produce a gently undulating topo-
graphy or such other topography as is
consistent with planned end use. of the
land. Grading shall be done In such a
manner as to control erosion and silta-
tlon of the affected area and surround*
ing property and water courses. Revege-
tation of the affected area must be
accomplished in accordance with the
previously approved mining plan.
Reclamation must be performed in accord-
ance with approved reclamation plan which
must meet the following standardsi The
final slopes in all excavations in soil.
sand, gravel, and other uncolidated
materials shall be at such an angle as
to minimize the possibility of slides
and be consistent with the future use
of the land. Provisions for safety to
persons and to adjoining property must
be provided in all excavations In rock.
In open cast mining operations* all
overburden and spoil shall be in a
configuration which is in accordance
with accepted conservation practices and
which is suitable for the proposed sub-
sequent- use of the land. Suitable drain-
age ditches or conduits shall bte const-
ructed to prevent collection of snail
pools of water that are noxious, odious.
or foul. The type of vegetative cover
and method of its establishment shall
conform to accepted agronomic and1- re-
forestation practices.
Regrade affected area to approximate
original contour, or rolling topography
or topography for higher end uset spread
topsoil or other suitable soil material
over the regraded area to a depth to two
feetf impound or treat runoff water to
reduce soil erosion, damage to agricul*
turai lands and pollution of streams i
back-slope final cuts and end walls to
an angle not to exceed 35 degrees from
the horizontal (operator may propose
alternative to backfilling if consistent
with the Act)j remove or bury all debris f
and sow, set-out, or plant cuttings. or
trees, shrubs, grasses, or legumes. All
reclamation shall be carried to comple-
tion- prior to the expiration of three
years after termination of the permit
term.
Cover all acid producing materials with
non toxic material] construct and raain-
of waters, erosion, land-slides, flooding
and tin* accumulation or discharge of acid
water) contour the affected area unless
the mining and reclamation plan provides
for terracing or other uses} and replace
segragated topsoil and grow vegetative
covering.
...
Yes
Yes
Yes
—
Yes
,
Yes
Yes
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oo
OKLAHOMA*
OREGON
i
*
PENNSYLVANIA*
The Mining Lands Rec-
lamation Act. Effect-
ive June 12, 1971.
An Act Relating to
mining. Oregon Leg-
islative Assembly
1971, Regular Session.
Effective July I, 1972.
Surface Mining Con-
servatton and Recla-
mation Act. Effect-
ive January 1, 1972.
All Minerals
|
All Minerals
All Minerals
Application for
permits must be
filed with the
Department of
Mines and Min-
ing. A recla-
mation plan Is
required.
Permits must be
obtained for all
operat i onsexceed -
ing 10,000 cubic
yards of material
extracted or at
least 2-acres of
land affected with-
in a period of 12
consecutive calendar
months. A reclama-
tion plan is requir-
ed.
Application for
permits must be
filed with the
Department of
Environmental
Resources. A
reclamation
plan is required.
$50
Basic fee-
Si 50. Ann-
ual renewal
fee-$50.
$50 for per-
sons mining
2000 tons or
less of mark-
etable min-
ers-Is other
than coal
per year, and
$500 for min-
ing coal or
more than
2000 tons of
other mark-
etable min-
erals per
year. Annual
renewal-$50
for mining
2000 tons or
less of mark-
etable miner-
als other than
coal and $300
in the case oi
all other
minerals.
Mining with-
out a perait-
not less than
$50 nor more '
$1000. Esch
day constitut-
es a separate
offense.
Mining with-
out • permit -
a fine not
exceeding
$1000.
Violation of
any rules or
regulations Is
punishable by
a fine of not
less than $25
nor more than
$250. or impri-
sonment for not
more than 60
days or both.
Mining with-
out a permlt-
$5000 or an
amount of not
less than the
total profits
derived from
unlawful act-
ivities, to-
gether with
the cost of
restoring the
land to its
original con-
dition or I.
year imprison-
ment, or both.
Not less than $350
nor more then $650
for each acre to
be affected. For
coal and copper
mining the minimum
bond shall be $5000.
For ail other mining
the minimum bond
shall be $1000.
Not to exceed $300
per acre to be
surface mined.
An amount suffici-
ent to Insure com-
pletion of the rec-
lamation plan not
less than $5000,
except In the case
of minerals other
than anrhracite and
bituminous coal
where it Is deter-
mined that the am-
ount of marketable
minerals to be ex-
tracted does not
exceed 2000 tons.
no bond shall be re-
quired. Liability
under the bond shall
be for the duration
of the operation and
for 5-y«ars there-
after.
Grade peaks and ridges of overburden to a
rolling topography, but the slopes need
not be reduced to less than the original
grade prior to mining! and the slope of
ridge resulting from th* box cut need
not be reduced to less than 2S-degrees
from the horizontal] construct earth
dans to form lakes in pits resulting
from surface nining operations! cover
exposed faces of miners! seaas with not
less than 3-feet of earth to support
plant life or with a permanent water
Impoundment* *nd revegetate affected
landi except that which is to be covered
with water or used for hoacsltes or in-
dustrial proposes, by planting trees.
shrubs or other plantings appropriate to
future usa of the land.
Reclamation of the affected land must be
performed in accordance with the approved
reclamation plan which must contsint mea*
sures to be undertaken by the operator in
protecting the natural resources of adja-
cent landsi measures for the rehabilita-
tion of the surface-mined lands and the
procedures to be applied} procedures to
be applied In the surface Bin ing opera-
tion to control the discharge of conta-
minants and the disposal of surface min-
ing refuse) procedures to be applied In
the rehabilitation of affected stream
channels and stream banks to a condition
minimizing erosion, sedimentation and
other factors of pollution} such maps
and other documents as may be requested
by the Department of Geology and Mineral
Industrlesi and a proposed time schedule
for the completion of reclamation opera-
tions.
Backfill all pits within 6-nonths after
completion of mining. Such backfilling
shall be terraced or eloped to an angle
not to exceed the original contour. Plant
grasses and trees or grasses and shrubs
upon affected land within 1-year after
backfilling.
Yes
Yes
Yes
yes
•
Yes
y«s
Operators mining
minerals other than
anthracite and btt-
uninous coal, the
amount of which
does not exceed
2000 tons, shall be
exempt from obtain*
ing the required
$100.000 certific-
ate of public
liability insuran-
ce snd posting the
required bond.
-------
IV)
SOUTH CAROLINA*
SOUTH DAKOTA
TENNESSEE*
VIRGINIA
Mining Act. Effect-
ive July ,1, 1974.
urf ace Mining Land
eclamatlon Act.
ffective
uly 1, 1971.
The Tennessee Surface
Mining Law. Effective
March 23, 1972.
'Chapter 17, Title 45.1.
Code of Virginia (1950)
as amended. Effective
April 10, 1972.
Title 45.1. Chapter 16,
Code of Virginia, 1950
as amended. Effective
June 27, 1966.
All Minerals
11 Minerals
4
All minerals except lime-
stone, marble, and dimen-
sion stone.
Coal
Other minerals
permits must fee
filed with the
Land Resources
Conserve 1 1 on
Commission. A
reclamation plan
is required.
Permit applica-
tions must be
filed with the
State Conserva-
tion Commission.
A reclamation
plan is required.
Applications for
permits must be
filed with the
Commissioner,
Department of
Conservation. A
reclamation plan
is required.
Permit applica-
tions must be
filed with the
Department of
Conservation
and Economic
Development.
A reclamation
plan is required.
Permit applica-
tions must be
filed with the
Department of
Conservation
and Economic
Development.
A reclamation
plan Is required.
$50 • $25
for each
renewal.
$250 plus
$25 for
each acre
to be mined.
The total
amount not
to exceed
$2,500.
Prospecting
permit-$10 per
acre. Surface
mining permit -
$12 per acre.
Annual fee-$6
per acre.
$6 for each
acre to be
affected not
to exceed
a total of
$150.
ation of the
Act or ralsrep-
esentatlon of
acts or giv-
ng false inf fl-
at! on on permit
ppllcations-not
less than $10O
nor more than
S1000 fine for
each day the
violation con-
tinues.
Violation of
the Act's
provisions-
a fine of
not less
than $1000
for each day
the violation
continues.
Violation of
the Act-fine
of not less
than $100 nor
more $5,000
for each day
violation
continues.
Hi 11 full vio-
lation-not less
than $1000 nor
more than $5000
or imprisonment
not to exceed
1-year, or both.
Violation of
the Act-fine
of not more
than $1000
or imprison-
ment for not
more than
1-year or
both. Each
day viola-
tion contin-
ues constit-
utes a sepa-
rate offense.
Violation of
Act-Maximum
fine of $1000
or I -year in
jail, or both.
$? SOO to $25,OOO
or a greater amount
depending upon the
number of acres to
be affected.
An amount suffici-
ent to cover the
cost of reclamation.
Hot less than $400
for minerals other
than coal and not
less than $600 for
coal for each esti-
mated acre to be
affected.
Prospect lng-$300
per acre . Surface
•ining bond-no less
than- $200 or store
than $1000 per acre te
be nined. Hlni*ium
bond- $2,500, except
when the operation
involves less than 5-
acres, the bond shall
not be less than $1000
$50 per acre based
upon the number of
acres to be dist-
urbed. The mini-
mum amount of bond
furnished shall be
$1000.
Reclamation to he performed in accordance *
with the approved reclamation plan which
must meet the following standards! The
final si open in all excavations shall be at
such an angle so as to minimize the poss-
ibility of slides; provide safety to per-
sons and to adjoining property; in open
cut mining, overburden and spoil shall be
left In a configuration Suit —
.able for subsequent use of the land; and
construct suitable drainage to prevent the
collection of snail pools of water that
are, noxious or likely to become noxious,
odious, or foul. The type of vegetative
cover and method of its establ ishaent shall
conform to accepted recommended • agronomic
and reforestation practices. The plan
must further provide that reclamation act-
ivities be completed within 2-years after
completion or termination of mining on
each segment of the area for which a per-
mit is issued unless a longer period is
specifically authorized.
Isolate all toxic or other material that have
a damaging effect upon ground and surface
waters, fish and wildlife, public health
and the environment; reclaim surface mined
areas to control erosion, provide vegeta-
tion, and eliminate safety hazards; repl-
ace topsoll evenly over reclaimed area;
revegttate in accordance with agronomic
and forestry recommendations; and upon
completion of operations, remove all
structures, machinery, equipment, tools
and materials from the site of operation*
Coal i cover all acid producing material;
seal off any breakthrough in mine or pit
walls which creates a hazard; control
drainage to prevent damage- to adjacent
lands, soil erosion and pollution of
streams and waters; remove all refuse
except vegetation resulting from the
operation; provide adequate access roads
to remote areas; on steep slopes, regrade
area to approximate original contour or
rolling topography and eliminate highwalls.
spoil piles and water-collecting depressions
(grading and other soil preparation to acco-
modate vegetation shall be completed within
6-months following Initiation of soil disWr
'cance), Revegetate the affected area with
grasses or legumes to prevent soil erosion.
Minerals other than coalt regrade the area
to approximately the original or rolling
topography, and eliminate all highwalls.
spoil piles, and water collecting depres-
sions; control drainage to prevent soil
erosion, damage to adjacent lands, and
pollution of streams and other waters; and
revegetate with trees, grasses, or leguneB.
Remove all debris resulting from mining
operations; regrade the area in a manner
established by rules and regulations;
grade overburden to reduce peaks and
depressions between peaks to produce a
gently rolling topography; preserve ex-
istent access roads; and plant trees.
shrubs, grasses or other vegetation upon
areas where revegetation is practicable.
Same as for coal, except that in the case
of dimensional stone Md quarry operations,
special consideration Is given to the
peculiar nature of the excavated cavity.
Ye*
Ye*
Yes
Yes
es
Y«B
Yes
Yes
Yes
Yes
*
-------
WEST VIRGINIA*
ro
u>
o
WYOMING
Surface-Mined Land
Reclamation Act,
Chapter 64, Laws of
1970. Effective
January 1, 1971.
Article 6, Chapter 20,
Code of West Virginia.
Effective March 13,1971.
All Minerals
The Wyoming Environ-
intal Quality Act.
Article 4, Land
Quality. Effective
July I, 1973.
All Minerals
All Minerals
Permit applica-
tions must be
filed with the
Department of
Natural Resou-
rce. A recla-
mation plan is
required.
Applications
for permits
must be filed
with the De-
partment of
Natural Res-
ources.
Applications
for permits must
be filed with the
Administrator,
Division of Land
Quality. A recla-
mation plan is
required.
$25 per per.
mit year for
each locati-
on plus $5
per acre for
all acreage
exceeding
10-acres
which was
disturbed
during the
the previous
permit year.
Prospecting-
$300. Surface
mining-$500.
Annual renew-
al- $100.
Personal in-
jury and pro-
perty damage
insurance of
$100,000 and
$300,000 re-
spectively is
also required.
Surface min-
ing fee-5100
plus $10 for
each acre to
be affected
with a $2000
maximum. Am-
ended permit-
$200 plus $10
per acre with
a $2000 maxi-
mum. License
fee for miner-
al exploration
-$25.
ft-PEFIBER OF TOE
Mining without
a permit -misde-
meanor . An op-
erator can be
enjoined or
otherwise stop-
ped. Each
day's violation
constitutes a
a separate
offense.
Violation of
the law's
provisions-
$100 to $1000
fine or 6-
months impri-
sonment, or
both. Delib-
erate viola-
tion- $1000
to $10,000
fine or 6.
months impri-
sonment, or
both.
The Act Imp-
oses fines
ranging from
$10,000 to
$50,000 per
day depend*
Ing upon the
violation
involved.
criminal pen-
alties are
also prescri-
bed for cert-
ain violations
ranging from
6 -months to
2 -years impri-
sonment .
INTERSTATE MINI1
Not less than $100
nor more than $1000
per acre.
Hot less than $600
per acre nor more
than $1000 per acre
vith a $10,000
minimum.
Hot less than $10,000
except for scoria or
jade and sand and
gravel, in which case
the bond shall not be
less than $200 per
acre.
; COMPACT
In reclaiming excavations for use as
lakes, all banks shall be sloped to
2 -feet below the groundvater line at
a slope no steeper than 1^-feet hori-
zontal to 1-foot vertical. In all
other excavations, the side slopes shall b
no steeper than 1^-feet horizontal to
1-foot vertical for their entire leng-
th. All strip pits and open pits shall
be no steeper than 1-foot horizontal
to 1-foot vertical. The slopes of
quarry walls shall have no prescribed
slopes, except where a hazardous con-
dition is created the quarry shall be
graded or backfilled to a slope of
1-foot horizontal to 1-foot vertical.
In strip mining, peaks and depressions
of spoil banks shall be constructed to
a gently rolling topography. Suitable
drainage shall be constructed to pre-
vent the collection of stagnant water.
All grading and backfilling shall be
made with non-noxious, non-flamable.
noncombustible solids. All acid-
forming materials shall be covered
with at least 2 -feet of clean fill.
vegetative cover shall be required and
all surface mining that disturbs streams
must comply with State fisheries
laws.
Cover the face of coal and disturbed
area with material suitable to supp-
ort vegetative covert bury acid form-
ing materials, toxic material, or
materials constituting fire hazard t
Impound water. Dury all debris. The
law also contains requirements for
regrading surface mined areas where
benches reslut specifying the maxi-
mum bench width allowed. On land
where benches do not result complete
backfilling is required but shall not
exceed the original contour of the
land. The backfilling shall elimin-
ate all highwalls and spoil peaks.
Planting is required.
Protect the removed and segregated top-
soil from wind and water erosion and
from acid or toxic materials! cover,
bury, impound or otherwise contain rad-
ioactive material; conduct contouring
operation to achieve planned use) back-
fill, grade, and replace topsoll or
approved subsoil; replace vegetationi
prevent pollution of surface and sub-
surface waters! and reclaim affected
land as mining progresses in conform-
ity with the approved reclamation plan.
Tea
Yes
Yes
Yea
Yes
Yes
An operator who
causes damage to
property of others
shall be liable to
them in an amount
not in excess of
three times the
provable amount of
such damage. A
$10,00 certificate
of insurance must
be filed to cover
such damage.
-------
APPENDIX A -2
SLOPE RESTRICTIONS AND STATE LAWS AND REGULATIONS
AND TENNESSEE VALLEY AUTHORITY CONTRACT REQUIREMENTS
Source: United States Department of Interior,
Bureau of Mines, Division of Environment,
Washington, D.C.
KENTUCKY - Slope Max bench width
(Degrees) (feet)
12-llt 220
15-18 170
19-20 155
21 lUo
22 130
23 120
21* 110
25 100
26 90
27 80
Auger only - 28 80
29-30 55
31-33 U5
Greater than - 33 0
From Regulations SMR-6-F(l) of Kentucky Reclamation Commission, Effective
December 8, 1967, Under Kentucky Revised Statutes 350.028, Strip Mining and
Reclamation Law of 1966.
MARYLAND - No fill bench on slopes greater than 20°
From Rules and Regulations 08.06.01.1103 of the Maryland Geologic Survey
Bureau of Mines, Effective October 25, 1973, Under Maryland Code 66C, Strip
Mining Laws of Maryland 1971.
MONTANA - Contour mining is not allowed. No final graded slope, shall be
steeper than 5:1 (11 degrees).
From Regulations S10310- (l)e of the Montana Administrative Code, under
Chapter 325 Montana Laws, Senate Bill #9^, the Montana Strip Mining and
Reclamation Act of 1973.
231
-------
TENNESSEE -
Slope below outcrop
(Degrees)
Less than - 15
15.0-18
18.1-20
20.1-22
22.1-2U
2U.1-26
26.1-28
Greater than - 28.0
Max solid bench width
(feet)
no restriction
125
106
9^
82
71
55
0
From Regulations 11.22 of the Tennessee Department of Conservation,Effective
March 23, 1973, Under Section U of Chapter 5^7 of Tennessee Public Acts,
Tennessee Surface Mining Law of 1972.
WEST VIRGINIA -
Less than -
Greater than-
Slope
' (Degrees)
15
20
25
30
33
33
Max solid bench width
(feet)
250
150
120
100
60
0
From part 20-6-13 of West Virginia Surface Mining and Reclamation Act of 1971»
Effective March 13, 1971.
MAXIMUM ALLOWABLE BENCH WIDTHS IN FEET
SLOPE ABOVE COAL
(Degrees)
Under 18 118-20 |20-22 |22-2U |2U-26 | 26-28 | Over 28
Under 18
18-20
SLOPE
BELOW 20-22
COAL
(Degrees) 22-2^
2U-26
26-28
Over 28
No Restrictions
11U
106
98
88
72
106
100
92
83
68
100
9^
87
78
6U
95
89
82
7U
61
91
85
78
71
58
86
81
75
67
55
83
78
72
6U
53
No Mining
From 1971 Contract Provisions (Surface), Appendix A of "Policies
Relating to Sources of Coal Used By TVA for Electric Power
Generation"
232
-------
CONVERSION TABIiE FOR CHANGING
DEGREES TO PERCENT
DEGREES
8
9
10
11
12
13
lU
15
16
IT
18
19
20
21
22
23
2k
25
26
PERCENT •
lit
16
18
19
21
23
25
27
29
30
32
3U
36
38
HO
U2
hk
k6
U9
DEGREES
27
28
29
30
31
32
33
3U
35
36
37
38
39
1+0
Ui
U2
H3
uu
U5
PERCENT
51
53
55
58
60
62
65
67
70
73
75
78
81
8U
87
90
93
96
100
Source: Elmore C. Grim, MPCB, NERC, EPA, 8/12/7^.
233
-------
APPENDIX B
DRAINAGE HANDBOOK FOR SURFACE MINING
Source - Department of Natural
Resources Division of Reclamation
Charleston, West Virginia
EXCAVATED SEDIMENT PONDS (Excerpt)
DEFINITION
A water impoundment is made by excavating a pit or "dugout". The use of an
earth embankment is permissible to increase capacity; however, ponds resulting
from both excavation and embankment are classified as SEDIMENT DAMS,
EMBANKMENT TYPE where the depth of water impounded against the embankment at
the emergency spillway elevation is 3 feet or more.
PURPOSE
To preserve the capacity of reservoirs, ditches, canals, diversions, waterways
and streams and to ..prevent undesirable deposition on bottom lands, in channels
or waterways, and other areas by providing basins for the deposition and
storage of silt, sand, stone, gravel and other detritus.
SCOPE
This standard establishes the minimum acceptable quality for the design and
construction of excavated sediment ponds in predominantly rural or
agricultural areas in West Virginia.
LOCATION
Excavated sediment ponds fed by surface runoff may be located on almost any
type of topography however, they are most satisfactory in areas with relative-
ly flat terrain. An excavated pond may be located in a natural or
constructed drainway or to one side of a natural or constructed drainway if
the runoff can be directed into the pond.
Site conditions shall be such that the following capacity requirements can be
met.
-------
CAPACITY REQUIREMENTS
The excavated sediment pond shall have a minimum capacity (from the lowest
elevation in the dugout to the crest of the exit channel or emergency spill-
way) to store .125 acre-feet per acre of disturbed area in the watershed. The
disturbed area includes all land affected by previous operations that is not
presently stabilized and all land that will be affected during the surface
mining and reclamation work. The sediment pond shall be cleaned out when the
sediment accumulation approaches 60% of the design capacity. The design and
construction drawings shall indicate the corresponding elevation.
When excavated sediment ponds are constructed in series, the required storage
for sediment for any pond shall be based on the uncontrolled drainage area
above the pond.
SEDIMENT POND DIMENSIONS
Excavated sediment ponds may be constructed to any desired shape that will
meet sediment capacity requirements. The width and depth of sediment ponds
are not limited.
Side slopes of excavated sediment ponds shall be such that they will be stable
and shall not be steeper than 2 horizontal to 1 vertical in earth and
\ horizontal to 1 vertical in rock.
ENTRANCE CHANNEL
The entrance channel shall have a minimum slope of U horizontal to 1 verticle,
extending from the bottom of the excavated pond upstream to the original
streambed. The entrance channel shall be protected with 1.5 foot layer of
rock riprap which shall have 25$ of the material 18 inches in diameter or
slightly larger and the remaining 15% well graded with sizes to fill the voids
between the larger rocks. Minimum side slopes shall be 2 horizontal to 1
vertical and shall also be protected with rock riprap for a vertical height of
2 feet.
EXIT CHANNEL
Pipe principal spillways shall not be required for excavated ponds. The crest
of the exit channel will be thoroughly protected with rock riprap to prevent
erosion and scouring. The exit channel shall be located as far as possible
from the inlet channel with a minimum distance of 50 feet.
EMBANKMENT AND EMERGENCY SPILLWAY
An earth embankment may be used to increase the capacity of an excavated
sediment pond provided that the depth of water impounded against the embank-
ment at the elevation of the emergency spillway is less than 3 feet. An
emergency spillway will be required when earth embankments are used. The
235
-------
design of the emergency spillway shall conform to that given under Emergency^
Spillways in Sediment Dams, Embankment type. The emergency spillway may "be
waived when the height of the embankment is less than 5 feet and when the
drainage area is 20 acres or less.
The earth embankment shall be high enough to have one foot of freeboard
between the maximum design flow elevation in the emergency spillway and the top
of the embankment. Earth embankments without emergency spillways shall have
2 feet of freeboard between the sediment pool elevation and the top of the
embankment. The minimum top width shall be 1^ feet. The side slopes will be
no steeper than 3 horizontal to 1 vertical on the upstream side and 2
horizontal to 1 vertical on the downstream side.
Embankments constructed without emergency spillways shall have an upstream
slope of 3 horizontal to 1 vertical and a downstream slope of 5 horizontal to
1 vertical. The entire downstream slope shall be protected with a 1.5 foot
layer of rock riprap which shall have 25$ of the material 18 inches in dia-
meter or slightly larger and the remaining 75$ well graded with sizes to fill
the voids between the larger rocks. A cutoff trench will not be required.
The design height of the embankment shall be increased by 10 percent to allow
for settlement.
UTILITIES UNDER EMBANKMENTS
Utilities encountered at dam sites must be relocated" away from the site
according to the standard criteria and procedure of the utility company
involved.
DISPOSAL OF WASTE MATERIAL
The waste material from the excavated sediment pond may be spread, used in the
embankment or removed from the site as conditions warrant.
The waste material,when not removed from the site, shall be placed in a manner
that its weight will not endanger the stability of the pond side slopes and
the rainfall will not wash the material back into the pond. Not less than
12 feet should be left between the toe of the waste material and the edge of
the pond.
If the waste material is spread, it should be to a height of no more than
3 feet with the surface graded to a uniform slope away from the pond. The
pond side slope of the spread material should be no steeper than 2 horizontal
to 1 vertical.
If the waste material is to be used in an embankment, it shall be free of all
sod, roots, stones over 6 inches in diameter, and other objectionable
material.
236
-------
SAFETY
The embankment, pool area and vegetated spillway shall be fenced as needed to
restrict accessibility for reasons of safety. All fences shall be constructed
in accordance with good fencing practices. Warning signs of danger shall be
installed where deemed necessary.
VEGETATIVE PROTECTION AGAINST EROSION
The waste material, spillway, embankment and any other area disturbed during
construction shall be mulched and vegetated immediately upon completion of the
pond in accordance with Reclamation Rules and Regulations for revegetation.
FLAWS, DRAWINGS AND SPECIFICATIONS
In addition to the "Drainage Map", there shall also be submitted the following
items concerning excavated sediment ponds:
1. A "Structure Proportioning Computations Sheet" to be completed for
each proposed pond.
2. Construction plans showing a plan view and a cross-section view with
entrance and exit channels.
3. A cross-section view of the embankment and emergency spillway, if
used.
U. Cross-sections plotted at 50 foot intervals showing original ground
line and the proposed excavation limits (Note: This requirement
will be waived if sediment pond is to be constructed in a regular
shape. See computations sheet).
5- Construction Specifications
CONSTRUCTION SPECIFICATIONS
I. Site Preparation
The pond site and waste areas shall first be cleared of all woody vegetation.
The limits of the excavation and spoil placement areas should be staked, and
the depth of cut from the ground surface to the pond bottom should be
indicated on the stakes.
If the embankment is to be constructed, the embankment site shall be cleared
of all brush, trees, stumps, roots and other undesirable material. Sod and
topsoil shall be stripped from the embankment site.
237
-------
II. Excavation
Excavation and placement of the waste material shall "be done as near to the
staked lines and grades as skillful operation of the equipment will permit.
Side slopes of the excavated pond will be no steeper than 2 horizontal to
1 vertical in earth and \ horizontal to 1 vertical in rock.
III. Selection and Placement of Embankment Materials
If an embankment is constructed, the most iflipervious material will be used in
the center portion. When sandy gravelly material is encountered, it shall be
placed in the outer shell, preferably in the downstream portion of the em-
bankment. The fill material shall be taken from approved designated borrow
areas. It shall be free of roots, woody vegetation, oversized stones, rocks,
or other objectionable material. Areas on which fill is to be placed shall
be scarified prior to placement of fill. The fill material should contain
sufficient moisture so that it can be formed into a ball without crumbling.
If water can be squeezed out of the ball, it is too wet for proper compaction.
Fill material will be placed in 6- to 8-inch layers and shall be continuous
over the entire length of the fill. Compaction will be obtained by routing
the hauling equipment over the fill so that the entire surface of the fill is
traversed by at least one tread track of the equipment, or compaction shall
be achieved by the use of a compactor. The embankment shall be constructed
to an elevation 10 percent higher than the design height to allow for settle-
ment if compaction is obtained with hauling equipment. If compactors are
used for compaction, the overbuild may be reduced to 5 percent.
TV. Vegetative Protection Against Erosion
The waste material, spillway, embankment and any other area disturbed during
construction shall be mulched and vegetated immediately upon compaction of the
pond in accordance with Reclamation Rules and Regulations for revegetation.
v- Erosion and Pollution Control
Construction operations will be carried out in such a manner that erosion and
water pollution will be minimized. State and local laws concerning pollution
abatement shall be complied with.
238
-------
APPENDIX C
ENGINEERING STANDARD FOR DEBRIS BASIN FOR
CONTROL OF SEDIMENT FROM SURFACE MINING
OPERATIONS IN EASTERN KENTUCKY
Source: United States Department of
Agriculture, Soil Conservation Service,
Lexington, Kentucky
DEFINITION
A barrier or dam constructed across a waterway or in other suitable locations
to form a silt or sediment basin.
PURPOSE
To preserve the capacity of reservoirs, ditches, canals, diversions, waterways
and streams and to prevent undesirable deposition on bottom lands, and other
developed areas, by providing basins for the deposition and storage of silt,
sand, gravel, stone and other debris.
SCOPE
This standard establishes the minimum acceptable quality for the design and
construction of debris basins located in predominantly rural or agricultural
areas in the Eastern Kentucky coal field when:
1. Failure of the structure would not result in loss of life; in
damages to homes, commercial or industrial buildings, main highways, or
railroads; in interruption of the use or service of public utilities; or
damage existing water impoundments; or
2. The contributing drainage area does not exceed 300 acres; or
3. The product of the storage times the effective height of the dam
does not exceed 3000 where the storage is defined as the original volume
(acre-feet) in the reservoir at the elevation of the crest of the
emergency spillway and the effective height of the dam is defined as the
difference in elevation (feet) between the emergency spillway crest and
the lowest point in the cross-section taken along the centerline of the
dam; or
239
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U. The vertical distance between the lowest point along the GL of the
dam, excluding the channel section, and the crest of the emergency
spillway does not exceed 20 feet; and
5. The debris basin conforms to all state and local laws and/or
regulations pertaining to the storage of water.
DRAINAGE AREA AND SITE EVALUATIONS AND LIMITATIONS
The contributing watershed above the site shall have an adequate plan for
providing protection against erosion of disturbed areas. This plan shall
provide for rapid revegetation of the disturbed area in order to stabilize the
area as quickly as possible after it has been disturbed. It is required to
prevent excessive sedimentation from exceeding the design capacity of the
debris basin. All disturbed areas (old and new) in the watershed shall be
revegetated according to Kentucky Division of Strip Mine Reclamation
regulations.
Site conditions shall be such that the following capacity requirements can be
met.
CAPACITY
I. Sediment
The sediment pool shall have a minimum capacity (from the lowest elevation in
the reservoir of the crest of the principal spillway) of 0.2 acre-feet per
acre of disturbed area in the watershed. The disturbed area includes all land
affected by previous operations that is not presently stabilized and all land
that will be affected throughout the life of the structure.
II. Principal Spillway
The required floodwater storage between the crest of the principal spillway and
the crest of the emergency spillway shall be determined from Figure 2, Flood-
water Retarding Storage - Eastern Kentucky Debris Basin (KY-ENG-L-32) revised,
except for sites having a contributing drainage area less than 50 acres. On
sites having a contributing drainage area less than 50 acres the required
floodwater storage need not be computed providing the minimum difference in
elevation between the crest of the principal spillway and the crest of the
emergency spillway is 1.5 feet. The minimum difference in elevation between
the crest of the principal spillway and the emergency spillway on any structure
shall be 1.5 feet.
The minimum size of the principal spillway shall be obtained from Table 1,
Required Principal Spillway Pipe Diameters. The minimum size shall be based
on the total drainage area above the structure,
2UO
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Table 1. REQUIRED PRINCIPAL SPILLWAY PIPE DIAMETERS
Drainage Area Corrugated Metal Drainage Area Smooth
(Ac) (In) (Ac) (In)
0-100 15 0-150 15
100-150 18 150-225 21
150-200 21 225-300 2k
200-300 2l»
III. Emergency Spillway
The emergency spillway shall be designed to safely carry the expected peak
rate of discharge from a 10-year frequency storm. There shall tie one foot
freeboard between the maximum design flow elevation in the emergency spillway
and the top of dam elevation. The 10-year frequency peak discharge shall be
obtained from Figure 1, Emergency Spillway Design Peak Discharge - Eastern
Kentucky Debris Basins (KY-ENG-L-33). This peak discharge is based on a
2^-hour duration, type II storm. The spillway shall be proportioned to pass
the peak discharge from Figure 1 at the safe velocity determined for the site.
Table 2, Emergency Spillway Hydraulics (KY-ENG-L-3U) shall be used to propor-
tion emergency spillways with side slopes equal to 2:1. Table 3, Emergency
Spillway Hydraulics (KY-ENG-L-3^) shall be used to proportion emergency
spillways with side slopes equal to 0:1 to 1:1. Chart Ho. 1, Emergency
Spillway Velocity Chart (KY-ENG-L-36) shall be used in conjunction with these
tables to proportion the emergency spillway.
IV. Structures in Series
When structures are built in series, the principal spillway and emergency
spillway sizes for the lower structure shall be based on the total drainage
area above the lower structure. The required storage allocation for sediment
for any structure shall be based on the uncontrolled drainage area above the
structure. For the design of a lower structure in series the required flood-
water storage between the crest of the principal spillway and the crest of the
emergency spillway shall be determined from Figure 2 based on the uncontrolled
drainage area above the lower structure.
When an existing upstream structure is not considered adequate or safe
according to the specification herein, a lower structure in series must be
designed considering failure of the upstream structure. This means that the
sediment and floodwater storage allocations shall be based on the total
drainage area above the lower structure. When the drainage area above the
upper structure(s) exceeds 25 percent of the total drainage area above the
lower structure the emergency spillway design of the lower structure shall
be based on the peak discharge of the hydrograph produced by'adding the
hydrograph from the uncontrolled area above the lower structure to that
hydrograph resulting from a sudden breach of the upper structure when its
-------
KY-ENG-L-33
(11-70)
FIGURE 1
EMERGENCY SPILLWAY DESIGN PEAK DISCHARGE
EASTERN KENTUCKY DEBRIS BASINS
10,000
10
100
1000
1000
o
o
-------
KY-ENG-L-34
(11-70)
TABLE 2
EMERGENCY SPILLWAY HYDRAULICS
EASTERN KENTUCKY DEBRIS BAS1HS
Side Slopes » 2:1
Sb-Ft
X. 10
to-FtV
0
0.
1.
I.
2.
2.
3.
3.
4.
4.
5.
5.
6.
6.
7.
7.
8.
8.
9.
9.
10.
5
0
5
0
5
0
5
0
5
0
5
0
5
0
5
0
5
0
5
0
0
6
20
39
64
94
129
169
212
258
305
364
422
482
550
618
690
764
845
924
1010
15
0
9
30
59
96
141
194
254
318
387
458
546
633
723
825
927
1035
1146
1268
1386
1515
20
0
12
40
78
128
188
258
338
424
516
610
728
844
964
1100
1236
1380
1528
1690
1848
25
0
15
50
98
160
235
323
423
530
645
763
910
1055
1205
1375
1545
1725
1910
30
oii
0
18
60
118
192
282
387
507
636
774
915
1092
1266
1446
1650
1854
35
*uiAk(
0
21
70
137
224
329
452
592
742
903
1068
1274
1477
1687
1925
40
1& CfS
0
24
80
157
256
376
516
676
848
1032
1220
1456
1688
1928
45
0
27
90
176
288
423
581
761
954
1161
1373
1638
1899
50 55
0 0
30 33
100 110
196 216
320 352
470 517
645 710
845 930
1060 1166
1290 1419
1525 1678
1820
60 65 70 75
0000
36 39 42 45
120 130 140 150
235 255 274 294
384 416 448 480
564 611 658 705
774 839 903 968
1014 1099 1183 1268
1272 1378 1484 1590
1548 1677 1806 1935
1830
Reference - SCS Technical Release No. 35 (Z-2, n=0.040, L«=100 Ft.)
USDA-SCS
November 1970
(K-2155)
-------
KY-ENG-L-35
(11-70)
TABLE 3
EMERGENCY SPILLWAY HYDRAULICS
EASTERN KENTUCKY DEBRIS BASINS
Side Slopes 0:1 to 1:1
\6-Pt
^
X w
0
0.5
1
1
2
2
3
3
4
4
5
5
6
6
.0
.5
.0
.5
.0
.5
.0
.5'
.0
.5
.0
.5
7.0
7
.5
8.0
8.5
9.0
9.5
10.0
0
6
20
39
64
93
126
163
202
247
294
342
397
446
508
565
632
691
758
830
900
15
0
9
do
59
96
139
189
245
303
371
441
513
596
669
762
848
948
1037
1137
1245
1350
20
0
12
40
78
128
185
252
326
404
494
588
684
794
892
1016
1130
1264
1382
1516
1660
1800
25
0
15
50
98
160
231
315
408
505
618
735
855
993
1115
1270
1413
1580
1728
1895
2075
2250
30
35
40
45 50 55 60 65
DISCHARGE CFS
00' 000000
18
60
118
192
278
378
489
606
741
882
1026
1191
1338
1524
1695
1896
2073
2274
Reference - SCS Technical Release No.
21
70
137
224
324
441
571
707
865
1029
1197
1390
1561
1778
1978
2212
24
80
157
256
370
504
652
808
988
1176
1368
1588
1784
2032
35 (Z-0,
27 30 33 36 39
90 100 110 120 130
176 196 216 235 255
288 320 352 384 416
416 462 509 555 601
567 630 693 756 819
734 815 897 978 1060
909 1010 1111 1212 1313
1112 1235 1359 1482 1606
1323 1470 1617 1764 1911
1539 1710 1881 2052
1787 1985
2007
n-0.040, L* 100 Ft.)
70 75
0 0
42 45
140 150
274 294
448 480
648 694
882 945
1141 1223
1414 1515
1729 1853
2058
USDA-SCS
November 1970
(K-2156)
2UU
-------
KY-ENG-L-36
(11-70)
0.8 1.0
CHART NO. 1
EMEMERGENCY SPILLWAY VELOCITY CHART
n=0.040
Se-%
1.5 2.0 2.53.0 4.0 5.06.0 8.010.0 15.0 20.025.0
30.0
Se=Slope of Exit Channel
Ve=Velocity in Exit Channel
n=Manning's Friction Factor
0/b=Discharge per foot of
bottom width
r=Ratio of discharge at which the
exit channel slope is equal to the
critical slope.
1.0
USDA-SCS
November 1970
-------
KY-ENG-L-32
(REV 0-72)
u
z
I
LU
0
<
tt
o
t—
CO
o
Z
O
O£
<
i—
UJ
Q
O
O
UJ
O
Ul
FIGURE 2
FLOODWATER RETARDING STORAGE
EASTERN KENTUCKY DEBRIS BASINS
2.5
2.0
1.5
1.0
0.5
20
40
60
80
100
PERCENTAGE OF DRAINAGE AREA DISTURBED
USDA-SCS
OCTOBER 1972
2U6
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routed emergency spillway hydrograph reaches a maximum outflow, When the
drainage area of the upper structure (s^ is less than 25 percent of the total
drainage area above the lower structure, the emergency spillway of the lower
structure may be designed for the total drainage area above it neglecting the
existence of the upper structure.
When unusually large or hazardous structure(s) exist above a lower structure,
special considerations will be made in the design of the lower structure re-
gardless of the drainage area of the upper structure (s). This criteria
requires that construction must be completed on all upstream structure prior
to construction of a lower structure in a series.
PRINCIPAL SPILLWAYS
A drop inlet principal spillway will be required on all structures. The
capacity and size of the spillway shall be as outlined under Capacity Require-
ments. The crest of the principal spillway shall be located at the maximum
elevation of the sediment pool.
I. Layout
The principal spillway shall be straight in alignment when observed in plan.
The outlet end must extend to an elevation approximately 6 inches above the
stable channel bottom below the toe of the embankment. An adequate outlet
structure shall be provided when needed to prevent damage to the toe of the
embankment. The minimum slope of the principal spillway conduit shall be 1
percent to insure free drainage.
II. Conduits
The minimum diameter of the principal spillway shall be those shown in Table 1
and the maximum diameter shall be 30 inches. All conduits under embankments
must support the external loads with an adequate factor of safety. They must
withstand the internal hydrostatic pressures without leakage under full
external load and settlement.
Suitable types of conduits include steel, wrought-iron, cast iron, corrugated
metal, asbestos cement, concrete and rubber-gasket vitrified clay.
A. Asbestos Cement, Concrete and Vitrified Clay
These rigid conduits must be laid in a concrete bedding. The
maximum fill height over vitrified clay pipe cannot be more than
20 feet and it shall not be placed over more than 10 feet of com-
pacted earth fill.
1. Bedding:
Concrete bedding shall be placed beneath the pipe at minimum
thickness of U inches for at least 10 percent of the overall
height of the conduit. The bedding should have a base width
equal to the outside diameter of the pipe.
-------
2. Joints;
Conduit joints are to be designed and constructed to remain
watertight. A rubber gasket set in a positive seat which will
prevent displacement is to be provided.
B. Corrugated Metal Pipe
1. Iron or Steel (Zinc-Coated):
Corrugated metal pipe (iron or steel) shall conform to Federal
Specification WW-P-^05- It shall be close-riveted, asphalt-
coated and can be used only where the pH of the normal stream
flow is expected to be greater than ^.0 during the life of the
structure. Where the pH of the normal stream flow is expected
to be between U.O and 5.0 the pipe will be asbestos-bonded,
bituminous-coated, and have a paved invert. The minimum
thickness of pipe shall be obtained from Table U.
Table U. MAXIMUM FILL HEIGHT (l) FOR ROUND CORRUGATED IRON AND STEEL
Pipe (2- 2/3 x 1/2 inch Corrugations)
Diameter Area
(in) (Sq.ft.)
Maximum Fill Height - Ft.
16 Gage Ik Gage 12 Gage 10 Gage
8 Gage
15 1.23
18 1.77 35 ^0
21 2.U 26 30
2k 3.1k 23
30 k.9I 18
-
38
29
20
-
Uo
35
27
-
-
-
30
(l) Handbook of Steel Drainage and Highway Construction Products - 1967:
Maximum allowable deflection - 3 percent of diameter.
2. Aluminum:
Corrugated aluminum shall conform to Federal Specification
W-P-^02. It can be used only in soils having a pH greater
than k and less than 9- The difference in elevation between
the crest of the emergency spillway and the invert of the out-
let shall not exceed 15 feet. The minimum thickness of the
pipe shall be 16 gage.
2U8
-------
3. Joints;
All corrugated metal pipe shall be connected by a watertight
flange-type connection or by a watertight connecting band
specifically manufactured for a connecting band. The area
between the pipe and connecting bands.shall be treated with an
asphalt cement during installation to assure a watertight joint.
C. Steel (Smooth)
Steel pipe may be used where the pH of the normal stream flow during
the life of the structure is expected to be 5.0 or greater. It
shall be of standard strength and be connected by a watertight
mechanical or welded joint.
D. Wrought-Iron or Cast Iron
Iron pipe may be used under all soil and water conditions. It must
be of standard thickness and be connected by a watertight mechanical
joint.
III. Drop Inlet
The drop inlet riser shall be designed to provide a gradual drawdown after
each storm" event.. „ :The minimum height of the drop inlet will be 5 times the
diameter of the conduit. Circular drop inlet shall have a minimum diameter
equal to the diameter of the conduit plus 6 inches. Box inlets shall have a
width equal to the diameter of the conduit and length equal to two times the
diameter of the conduit.
A. Perforations or Slots
Metal risers shall be either perforated or slotted through their
length with 3/U" diameter holes or 6" (horizontal) x lV (vertical)
rectangular openings respectively. There should be approximately
U perforations per foot of length per foot of riser diameter or U
equally spaced slots per foot of length of riser with random vertical
alignment. Concrete risers shall be ported to provide the equiva-
lent drainage.
B. Base
The drop inlet shall have a base, usually concrete, attached with
a watertight connection. This base shall have sufficient weight
to prevent flotation of the drop inlet. The weight of the base
should equal or exceed 1.25 times the weight of the water displaced
by the riser.
IV. Anti-Seep Collars
All conduits through the embankment are to be provided with anti-seep collars
They shall be placed along the conduit within the saturated zone of the
-------
embankment at distances of not more than 25 feet. Collars shall be of the
number and size required to increase the seepage path along the conduit, a
distance equal to 15 percent of the length of the conduit within the embank-
ment. The anti-seep collars shall extend a minimum of 2.0 feet from the
conduit in all directions.
V. Anti-Vortex Device
An approved anti-vortex device shall "be installed on the principal spillway
inlet.
VI. Trash Racks
A suitable trash rack will be provided where the drainage area will contribute
trash to the reservoir area.
EMERGENCY SPILLWAYS
Emergency spillways are provided to convey large flows safely past an earth
embankment. They are usually open channels excavated in earth or rock or
constructed of compacted embankment or reinforced concrete.
I. Layout
The emergency spillway shall be excavated in durable rock or in earth. It
shall consist of an inlet channel, a control section, and an exit channel.
The capacity and size of the emergency spillway shall be as outlined under
Capacity Requirements. Minimum bottom width shall be 10 feet. Maximum Hp
shall be 10 feet.
The inlet channel shall be level for a minimum distance of 30 feet upstream
from the control section. The level part of the inlet channel will be the
same width as the exit channel, and its centerline will be straight and
coincident with the centerline of the exit channel. A curved centerline is
permissible in the inlet channel upstream from the level section, but it must
be tangent to the centerline of the level section. The level section of the
inlet channel shall be located so that the projected centerline of the dam
will pass through it.
The centerline of the exit channel will be straight and perpendicular to the
control section downstream to a point opposite the downstream toe of the dam.
Curvature may be introduced below this point if 'it is certain that the flowing
water will not impinge on the dam should the channel fail at the curve. The
slope of the exit channel shall be determined from Chart No. 1 (KY-ENG-L-36).
The layout will provide that the spillway when cut around the end of the dam
in the abutment be in natural ground (cut) to a depth equal to the maximum
design flow for at least the level section and the exit channel to a point
opposite the downstream toe of the dam. It is preferable that the flow be
confined without the use of leveess but where site conditions are such that
the exit channel will not contain the design flow, a levee or dike shall be
constructed along the exit channel to a height above the exit channel equal to
250
-------
the depth of flow through the spillway at the control section. The levee shall
have a minimum top width of U feet and side slopes not steeper than 2 hori-
zontal to 1 vertical. The levee shall be constructed in accordance with the
requirements for embankment.
The spillway shall be trapezoidal in shape and the side slopes shall not be
steeper than 1/U horizontal to 1 vertical in rock or 2 horizontal to 1
vertical in earth.
II. Permissible Velocities
A. Earth Emergency Spillways
The maximum allowable velocity in the exit channel shall be 5 feet
per second for earth emergency spillways. This velocity must not be
exceeded in the exit channel of the spillway from the control
section to a point in the exit channel opposite the downstream toe
of the dam or to a point downstream where a channel failure would
not cause the flow to impinge on the toe of the dam. All earth
spillways shall be vegetated with the most suitable vegetation for
the site.
Spillways excavated in earth shall be protected through the level
section and the exit channel by durable armor when the exit channel
velocity exceeds 5 feet per second. A maximum velocity of 12 feet
per second will be allowed where adequate protection is provided.
When the exit channel velocity is greater than 5.0 feet per second
but less than 10.0 feet per second, suitable protection shall be
provided by using well graded riprap having a maximum size of
18 inches and an average size of from 9-12 inches. This riprap shall
be placed at a minimum thickness of 1.5 feet through the bottom
and sides of the control section and exit channel to a point beyond
the toe of the embankment. When the exit channel velocity is from
10.0 to 12.0 feet per second the riprap shall be placed at minimum
thickness of 2.0 feet and have a maximum size of 2\ inches and
average size of 15-18 inches.
All riprap shall be durable rock.
B. Rock Emergency Spillways
The maximum allowable velocity shall be 1^ feet per second for rock
emergency spillways. A spillway shall be classed as a rock
emergency spillway when durable bedrock occurs throughout the level
section and in the exit channel to a point opposite the downstream
toe of the dam. Durable bedrock is defined as a layer of continuous
bedrock equal or greater in thickness than the depth of flow
through the spillway at the control section.
The most restrictive material occurring in the level section and the
outlet channel upstream from a point opposite the downstream toe of
the dam shall apply when determining maximum allowable velocities.
251
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EARTH EMBANKMENT (Figure 3)
I. Height
The earth embankment will be high enough to prevent overtopping while storing
the required sediment and floodwater volumes and passing the peak discharge
from an unrouted 10-year frequency storm through the emergency spillway plus
1 (one) foot freeboard.
II. Top Width
The minimum top width of the embankment shall be as follows:
Maximum Embankment Height-Ft. Minimum Top Width-Ft.
15 or less 10
15-25 12
25-1*0 lU
III. Side Slopes
The side slopes of the settled embankment will be no steeper than 2%
horizontal to 1 vertical.
IV. Cutoff Trench
A cutoff to relatively impervious material shall be provided under the embank-
ment along the centerline and up the abutment to the elevation of the crest of
the principal spillway. The cutoff trench should have a bottom width adequate
to accommodate the construction equipment but shall not be less than 8 feet.
The trench shall have minimum side slopes of 1 to 1.
V. Settlement Allowance
The design height of the embankment shall be increased by 5 percent (sheeps-
foot roller or equivalent compaction) to allow for settlement.
VI. Utilities Under Embankments
Utilities encountered at dam sites must be relocated away from the site or
reconstructed or modified to provide durability, strength, and flexibility
equal in all respects to the principal spillway designed for the site in
accordance with Service criteria and procedure,
VEGETATIVE PROTECTION AGAINST EROSION
The earth embankment spillways, borrow areas, and other disturbed areas shall
be vegetated to provide protection against erosion.
252
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ro
\s\
LO
ro :—
:S ™
CD
O)
ro 5". = jg- -«=•
P<2-^ ^?D
(Jt O ST O ED
CD" Z3 fO -*-^
O C^S CO m
cnO >_.^ 3.
cn ^o s"
O5?oS **: r?
SIDE SLOPES
TO 1
SPILLWAY
\
FT.
CREST OF EMERGENCY
SPILLWAY- ELEVATION
TOP OF DAM -ELEVATION \
~" \
\ ^CREST OF RISER - ELEVATION
CUT-OFF
TRENCH
Figure 3 TYPICAL PROFILE LOOKING DOWNSTREAM
-------
I. Seed Requirements
Only Kentucky 31 fescue may be used on earth spillways. Sericea Lespedeza and
Kentucky 31 fescue may be used on the embankments and borrow areas as needed
or desired.
A. Embankments
1. Kentucky 31 fescue at 50 pounds per acre or as needed.
2. Kentucky 31 fescue at 50 pounds per acre and over-seeded with
scarified lespedeza seed at 20 pounds per acre the following
early spring.
B. Spillways
1. Kentucky 31 fescue at 50 pounds per acre.
C. Borrow Areas and Other Disturbed Areas
1. Kentucky 31 fescue at 50 pounds per acre, or
2. Scarified sericea seed at hO pounds per acre, or
3. Scarified sericea seed at 30 pounds per acre and Kentucky 31
fescue at 15 pounds per acre.
II. Lime
Three (3) tons per acre of standard ground agricultural limestone shall be
uniformly distributed over the area to be seeded prior to seedbed preparation.
III. Fertilizer
1,500 pounds of 10-20-20 fertilizer per acre, or equivalent, shall be uniformly
distributed over the area to be seeded prior to seedbed preparation.
IV. Mulch
Two (2) tons of straw mulch per acre shall be uniformly applied to the surface
of the soil as soon as the seeding is completed and held in place using a
suitable procedure.
FENCING
The embankment, pool area and vegetated spillway shall be fenced as needed to
exclude livestock. All fences shall be constructed in accordance with good
fencing practices.
251*
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APPENDIX D
GUIDELINES FOR THE CONSTRUCTION OF MINE ROADS*
Source: Environmental Protection Agency
Region 10, Seattle, Washington
MINE ROADS
Proper planning, location, design, construction, use, and maintenance of all
roads - will reduce soil erosion problems. The following recommendations,
pertaining to roads, have been assembled under four headings: location,
design, construction and maintenance.
LOCATION
1. Locate all roads to avoid, or design them to counteract, unstable
soil areas. Select the gradient which will provide for a stabilized road
prism with proper drainage. Fit road locations to the topography so that
minimum alterations of natural conditions will be necessary.
2. Locate roads on natural benches, ridge tops, and flatter slopes to
minimize harmful disturbances of the terrain and to enhance the stability
of the roads. Use all available topographic surveys, soil-type maps, and
other soils and geologic information to select locations which avoid
steep slopes and unstable soils. Field observation and evaluation is
advisable in problem areas. Give full consideration to soil strength and
cohesion to determine the proper cut-and-fill slope rations and to
specify spacing for relief-drainage culverts.
3. Locate roads on stable areas well away from streams so as to leave a
filter strip of undisturbed vegetation at least 100 feet wide between the
toe of the fill slope and the stream. Avoid routes through the bottoms
of steep narrow canyons; through slide areas; through steep, naturally
dissected terrain; through slumps; through marshes or wet meadows;
through ponds; or along natural channels. Where alternative locations
through stable areas are not available, incorporate corrective stabiliza-
tion measures into the road design.
"Several sections of these guidelines have been changed by the authors of this
publication to reflect shortcomings as seen by them.
255
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DESIGN
Prescribe for each road those design specifications that are test adapted to
the given slope, landscape, and soil materials. Use a balanced design or
provide waste or borrow areas that will produce a minimum of damage to soils
and water. Cross streams where channel and bank disturbance will be minimal.
Avoid excessive sidehill cuts and fills, especially near stream channels.
Plan for retaining walls or riprap where needed to increase the stability of
fill embankments and cuts and to protect fill embankments from water erosion.
1. In critical situations, design for full-bench construction rather
than part bench and part compacted fill. Haul all excavated waste
material to safe bench or cover locations or use it in "through" fills
by raising their elevation.
2. Reduce backslope sloughing by rounding the tops of cut slopes.
3. Design fill at an angle less than the normal angle or repose.
^. Clear trees and other vegetation for only the minimum essential width
required for construction and maintenance of the road and choose the
design alignment and minimum road width necessary to serve traffic needs.
5. Divert or otherwide dispose of all drainage so that it does not pass
over or collect in new cuts, fills, borrow areas, or waste dumps. Do this
by providing bridges or adequate culverts at all natural water courses
both for permanent and temporary access or haul roads. Avoid channel
changes and stabilize the fill material of the approaches with riprap or
abutments. Where culverts must be installed in large fills, use concrete
or heavy riprap headwalls and wingwalls to prevent erosion of the fill and
to help direct the passage of debris through the major culverts. To pre-
vent disturbance of stream channel, use riprap, gabions (wire baskets full
of large rocks), or other structures where needed to protect roads that
must be constructed in canyon bottoms.
6. Design culverts or bridges large enough to carry at least a 25-year
frequency storm. West of the Cascades, use a 2^-inch or larger diameter
culvert for all live stream crossings to minimize fish migration
blockages.
7. In order to reduce fish passage problems and pipe abrasion, design
to use bridges or "true-arch" (bottomless) culverts on steep slopes. In
locations where bridges or bottomless culverts are impractical, design
for culverts with installed baffle plates to provide for fish passage
through the culvert. Orient culverts with natural stream channels and
extend them beyond the fill slopes. For anadromous fish passage, provide
an entrance pool at least 3 feet deep and 12 feet long at the outflow end
of the culvert. Stabilize the pool with barrier logs to prevent erosion.
Place the logs so there is no impassable drop between the culvert and the
stream.
256
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8. Provide an adequate drainage system that will reduce both the runoff
concentration in the roadway and the saturation of poorly drained soils.
Control measures mist include properly designed roadside ditches and
culverts. Give each relief culvert a minimum slope of one percent and
provide a sediment-catching basin at the entrance. Use downspouts and
other slope protection measures to avoid erosion of fill areas.
9- Provide dips, water bars, and cross drains in order to prevent water
accumulations. Put such structures close enough together so the collected
water will be small in amount and can easily be diverted off the road into
safe spreading areas or sediment control structures.
10. Design temporary roads to drain by outsloping wherever possible. On
long slopes, space dips in the road to assure diversion of runoff from the
road surface. For fills with culverts, place a dip at the downgrade
approach so that in the case of a flood or plugged culvert, the excess
water may flow over the road at that point.
11. Prevent muddy and turbid waters from draining off the roadbed and
into streams. Where necessary, make provisions to build up the surface
of dirt roads with rock, pave, or otherwise stabilize road surfaces in
order to minimize subgrade failures, road surface erosion, and road
maintenance grading. For temporary paving, use emulsified asphalt where
applications of oil and sulfite-waste liquor type dust inhibitors could
possibly wash into and contaminate receiving waters.
12. Obtain all road rock and gravel from dry quarries, mine construction
or from dry channels that are provided with adequate protection against
sediment production. Do not "wet" mine such road rock or gravel.
CONSTRUCTION
In many places, careless and improper construction of a mountain road can
nullify all the effort expended in well considered design and location.
Numerous mud-rock slides and land slumps have started at the edge of such roads
and, once started, have carried through hundreds of feet of stabilized slopes.
Poor construction and inadequate drainage have triggered land slumps in water-
shed after watershed and have resulted in the most serious form of accelerated
erosion.
Regular inspections should be made during construction by a qualified engineer
with authority to assure that road construction meets design requirements.
Therefore, during all phases of road construction, protect water quality by
using every possible and applicable soil and water conservation measure.
1. Where the road design calls for full bench construction, make the
full cut end-haul excess excavation from the cut, and deposit it in
stable locations well above the high water level. Do not deposit waste
257
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materials directly into any stream channel. Where necessary, compact all
fill material to reduce the entry of vater and to prevent the fill
material from settling. Do not place any woody or other organic debris
in the fill of any road.
2. Collect all construction-area drainage and keep it out of the
streams. Use seepage pits or other confinement measures to prevent
diesel oil, fuel oil, or other liquids from running into streams.
Use drip collectors on oil-transporting vehicles. Divert water for
sprinkler trucks a sufficient distance from the source to the filling
point to prevent overflow spilling or flushed tank water from reaching
the stream.
x
3. Keep soil disturbances to a minimum by construction roads only when
soil moisture conditions are favorable. Rough grade a new road only as
far as that road can be completely finished during the current
construction season. Finish ditches and drainage installations on the
section being worked upon before opening up another section or before
shutting down construction for the season.
k. Fully backslope each graded section except where vertical cut banks
are more stable than sloping ones. In critical slump areas, grade large
cuts to slopes of not more than 1.75 to 1 and use horizontal drain pipes.
Also, protect all large fill areas with surface drainage diversion
systems. Place culverts so as to cause the minimum possible channel
disturbance and keep fill materials away from culvert inlets and outlets.
During road constructiondo not permit earth moving activities when the
soils are saturated. Allow road machines to work in stream beds only for
laying culverts or constructing bridge abutments. Divert streamflow
from the construction site whenever possible in order to prevent or
minimize turbidity.
5. Clear drainage ways of all woody debris generated during road clear-
ing or construction. Windrow the clearing debris and crush it outside
the road prism except where burning of the debris is necessary to reduce
the fire hazard, prevent insect infestations, or to improve the
aesthetics.
MAINTENANCE
Fully and thoroughly maintain all portions of the road system to prevent water
quality degradation from accelerated erosion during heavy rainstorms. This
includes the regular maintenance of drainage diversions, such as cleaning
culvert inlets before and keeping them clean during the rainy season to
diminish the danger of clogging and the possibility of washouts. It also in-
cludes the inspection of revegetation on abandoned roads, and reseeding
where necessary. As specified for construction activities above, end-haul and
deposit all excavated material in safe bench or cover locations well above the
high water level. Never deposit such material directly into flowing streams.
258
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1. On all roads that outslope, cross drain them and remove all berms
on the outside edge except those intentionally constructed for the
protection of road grade fills.
2. Retain outslope road drainage by performing proper maintenance
grading. This precludes both the undercutting of newly or partially
stabilized cut slopes and the leaving of a berm (except for fill protect-
ion) along the outside edge of the road which might concentrate drainage
on the road. Before spring runoff begins, remove all ice and snow berms
created on winter haul roads.
3. Use extreme caution in the selection and application of herbicides
for controlling brush encroachment along road edges. Do not let any
such chemicals drift or run off into streams to cause objectionable
tastes or odors in the waters or to create adverse conditions for aquatic
life or human consumption. Use mechanical equipment in preference to
herbicides for control of roadside brush.
259
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APPENDIX E
ACCESS ROAD CONTROL
Source: West Virginia Surface
Mining Reg. 20-6, Series VII,
Sec. 5
HAULAGEWAYS (Excerpt)
5.01. Location - The location of the proposed haulageway shall be
identified on the site by visible markings at the time the reclamation and
mining plan is pre-inspected and prior to commencement of construction.
5.02. Grading - The grading of a haulageway shall be such that:
a. No sustained grade shall exceed
b. The maximum pitch grade shall not exceed 15$ for 300 feet;
c. There shall not be more than 300 feet of maximum pitch
grade for each 1,000 feet of road constructed;
d. The surface shall be insloped toward the ditch line at the
minimum rate of 1/2 inch per foot of surface width or
crowned at the minimum rate of 1/2 inch per foot of surface
width as measured from the center line of the haulageway.
5.03. Curves - The grade on switchback curves shall be reduced to less
than the approach grade and should not be greater than ten percent (10$).
5-OU. Cut Slopes - Cut slopes should not be more than 1:1 in soils or
lA:l in rock.
5.05. Ditches - A ditch shall be provided on both sides of a through-
cut and on the inside shoulder of a cut-fill section, with ditch relieve
cross-drains being spaced according to grade. Water shall be intercepted
before reaching a switchback or large fill and led off. Water on a fill or
switchback shall be released below the fill, not over it.
5.06. Culverts - Ditch relieve culverts shall be installed according to
the following provisions:
260
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a. Road Grade in Per Cent Spacing of Culverts in Feet
2-5 300 - 800
6-10 200 - 300
11 ~ !5 100 - 200
b. The culvert shall cross the haulageway at a 30 degree angle
downgrade;
c. The inlet end shall be protected by a headwall of suitable
material and the outlet end shall be placed below the toe of
the fill with an apron of .suitable material provided for the
outflow to spill on;
d. The culvert shall be covered by compacted fill to a depth of
on foot or half the culvert diameter, whichever is greater.
5.07. Culvert Openings - Culvert openings installed on haulageways should
not be less than one hundred (100) square inches in area, but, in any event,
all culvert openings shall be adequate to carry storm runoff and shall receive
necessary maintenance to function properly at all times.
5.08. Natural Drainway - Minor alterations and relocations of natural
drainways as shown on the reclamation plan will be permitted if the natural
drainwall will not be blocked and if no damage is done to the natural drainway
or to adjoining landowners.
5.09. Stream Crossings - Drainage structures shall be required in order
to cross a stream channel. They shall be such so as not to affect the flow of
the stream. Consideration will be given to the time of year the stream is
crossed and the length of time the stream channel is used, but in no event,
and under no conditions will the flow of the stream be affected or the sediment
load of the stream increase during construction and/or use.
5.10. Removal of Drainage Structures - No bridges, culverts, stream
crossings, etc., necessary to provide access to the operation may be removed
until reclamation is completed and approved by the director. The same
precautions as to water quality are to be taken during removal of drainage
structures as,those taken during construction and use.
5.11. Seeding of Slopes - All fill and cut slopes shall be seeded and
mulched during the first planting and/or seeding season after the construction
of a haulageway in accordance with Section 9 of these regulations.
5.12. Haulageway Surfacing - Haulageways shall not be surfaced with coal
refuse or any acid-producing or toxic material or with any material which will
produce a concentration of suspended solids in surface drainage.
261
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5.13. Tolerance - All grades referred to in this section shall be subject
to a tolerance of two percent (2%} grade. All linear measurements referred to
in this section shall tie subject to a tolerance of ten percent (10$) of
measurement. All angles referred to in this section shall be measured from the
horizontal and shall be subject to a tolerance of five percent (5$).
5.1^. Water Bars - Water bars of the ditch and earth berm or log type
shall be installed according to the following table of spacings in terms of
percent of haulageway grade prior to the abandonment of a haulageway:
Percent of Haulageway Spacing of Water Bars in Feet
2 250
5 135
10 80
15 60
20 1*5
Above 20 25
5.15 • Dust Control - Reasonable means shall be employed to prevent loss
of haulageway surface material in the form of dust.
5.l6. Abandonment of Haulageway - Upon abandonment of a haulageway, the
haulageway shall be seeded and every effort made to prevent erosion by means
of culverts, water bars or other devices. All haulageways shall be abandoned
in accordance with all provisions of Section 10 and lU, Article 6, Chapter 20,
Code of West Virginia, as amended, and Section 9 of these regulations.
262
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APPENDIX-F
PROJECT COSTS BY AGENCIES
Pollution Controls
Unit
Cost
Year
Comments
Surface backfilling by grading-
Method A
Kethod B "
Method C
Surface backfilling by using
explosives
Method D
Method E
Linear foot of
of blghwall
$5.18
$15.73
$11.70
$ll*.08
$8.8U
1965
1965
1965
1965
1965
U.S. Bureau of Mines - Report #6772 - 1966 -
Demonstration of five secondary backfilling methods,
Pennsylvania. In methods A,B, and C, the spoil is
sloped away from the highwall. Methods D and E
do not alter the original slope of the spoil,
original highvalls heights were 60 to 80 feet.
Surface slope averaged lU°.
o\
U)
Site preparation-clearing
grubbing and brush disposal.
Horth Central Section
Northwestern Section
Surface restoration to
approximate original contour.
Horth Central Section
Eorthwestern Section
Acre
Acre
Acre
Cubic Yard
Acre
Cubic Yard
33.5U
1+5.76
780.00
O.i6
1.U02.00
0.15
1967
1567
1967
1967
1968
U.S. Bureau of Mines - Report t8k^6 - 1970 -
Surface Mine Reclamation, Moraine State Park, Pa.
original highwall heights were 1*5 to 50 feet.
Surface slopes ranged up to 13°.
Ihese costs are based on equipment operating time
and do not include repair, maintenance costs, support
equipment and office facilities.
Surface backfilling by grading-
Kethod A Acre
Method A (Modified) Acre
Surface backfilling by using
explosives
Method E Acre
250.00
Uoo.oo
U60.00
1966
1967
The Myles Job Mine - A Study of Benefits and Costs
of Surface Mining for Coal in Northwest Virginia.
Secondary backfilling as developed in the El Campton
project were modified and used in this report.
Original highwall heights 75 to 80 feet. Surface
slope averaged 220.
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APPENDIX F (continued)
PROJECT COSTS BY AGENCIES
Pollution Controls
Unit
Cost
Year
Comments
ro
Surface backfilling by grading
and method.
Terracing - Fill all Acre
depressions, level spoil
to 15^ slope or less on
192 acres.
Revegetation Acre
Irrigating sludge Acre
Incorporating sludge Acre
into top 12" of soil
Palzo restoration project, Shawnee National Forest,
N.W. of Stonefort, Illinois. Ongoing project,
500.00 1972 utilizing treated municipal waste sludge to reclaijn
abandoned strip mined land which is causing severe
water pollution problems. While the tract is being
treated, research will study incorporation vs non-
100.00 1972 & 3 incorporation interactions with seeding of various
500.00 1972 & 3 grasses and their response to solids incorporation
100.00 1972 & 3 to various depths. Other administrative studies will
include:
1. Refined waste application techniques
2. Heavy metals available to plants
3. Bacteria and virus survival
Project is in the Sugar Creek Watershed which drains
into South Fork Saline River. Highwall heights
MD1 to 80'. Original slopes 10% to 20$. Surface
slopes now run up to 75$.
Surface backfilling by grading
and methods.
Terracing - E. Ky.
Scalping Acre
Grading Acre
Approximate original
contour - W. Ky.
Grading, inc. final pit Acre
Approximate original
contour - W. Ky,
Backfilling final pit Acre
only, having an 80'
highwall.
75.00
1*00.00
650.00
7,300.00
1967
1967
1967
Tennessee Valley-Authority, Chattanooga, Tennessee.
A study by TVA to determine reclamation, costs as
required by the 1966 Kentucky Revised Statutes and
regulations.
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APPENDIX F (continued)
PROJECT COSTS BY AGENCIES
Pollution Controls
Unit
Cost
Year
Comments
ro
ON
vn
Surface backfilling by grading
and rr.ethods.
Contour -
Clearing t grubbing Acre
Grading Acre
Revegetation Acre
Pasture -
Clearing & grubbing Acre
Grading Acre
Revegetation Acre
Swallow-tail
Clearing & grubbing Acre
Grading Acre
Revegetation Acre
Pasture & Contour
Clearing & grubbing Acre
Grading Acre
Revegetation Acre
Spoil Handling Cubic yard
Masonry seals
Dry Each
Wet Each
Clay Seals Each
$l61*.00
U72.00
282.00
78.00
568.00
111*. 00
25.00
582.00
1U8.00
15U.OO
1131.00
171.00
0.35
2202.00
1*076.00
950.00
1966
1967
1968
1966
1967
1968
1966
1967
1968
1966
1967
1968
1967
1967
1967
1967
Cost of Reclamation and Mine Drainage Abatement.
Elkins Demonstration Project. Water Quality Office,
Environmental Protection Agency, NERC, Cincinnati,
Ohio.
Project is in the Roaring Creek-Grassy Run water-
shed near Elkins, West Virginia. Original
highwall heights 1*0 to 50". Surface slopes were
from 20 to 1*0°. The figures listed are average
direct costs by various methods on selected work
areas, Project #1.
Stability of the reclaimed area has been exceptional
as only $2,000 for maintenance has been spent in
the last three years or less than 0.03 percent per
year of the construction cost.
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APPENDIX F (continued)
PROJECT COSTS BY AGENCIES
Pollution Controls
Unit
Cost
Year
Comments
ro
Reclamation costs for
various treatments of coal
refuse piles and slurry ponds.
Agriculture limestone
delivered and spread. Ton
Fertilizer, 6-2k-2k Ton
Incorporation
1. Rototilling to 8" Acre
2. Discing to 8" Acre
3. Hand-raking Acre
Grass Seed Ib.
1. Grass seed application Acre
Straw Mulch Ton
2. Mulch application and Acre
anchored with twine.
Dried Sewage Sludge
1. Hauling - 12 I/truck Hour
2. Application Ton
Soil Covering - Digging,
short hauling and placing
1. 1*" cover Cu yd
2. 12" cover Cu yd
3. 2k" cover Cu yd
5.50
55.30
00
00
3.00
.21*
3.00
30.00
27.00
12.00
,12
1.00
1.00
1.00
1969
1969
1969
1969
1969
1969
1969
I
1969
1969
1969
1969
1969
1969
1969
Environmental Protection Agency, Control of Mine
Drainage from Coal Mine Mineral Wastes - Project
No. lltOlO DDK by Truax-Traer Coal Co. Project is
near DuQuoin, Illinois at the inactive New
Kathleen Mine. Purpose to demonstrate effective
means to abate air and water pollution from coal
mining refuse piles and slurry lagoons.
Vegetative covers can be established, as an
abatement measure, on highly acidic mineral
wastes, with and without the use of topsoil. The
key to success is the application and rotatilling of
sufficient quantities of agricultural limestone
followed by proper addition of fertilizer.
The long-term effects of establishing grass cover
directly on mineral wastes without the use of top-
soil are not known at this time.
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APPENDIX G
BACKFILLING, GRADING, RECLAMATION AND.METHOD OF OPERATION
t Source: Kentucky, Strip Mine Regulation 6,
Section E, Revised December 8, 1967
CURRENT GRADING (Excerpt)
In order to be considered current grading and backfilling shall meet the
following requirements:
(l) On lands where the method of operation does not produce a bench
(area strip mining), the grading and backfilling shall not be more
than two spoil ridges behind the pit being worked, the spoil from
this pit being considered the first ridge. All backfilling and
grading shall be completed within ninety (90) days after the
completion of an operation or a prolonged suspension of work in the
area. Modifications to these requirements may be made by the
Division in connection with the backfilling of the .final pit.
(2) On lands where the method of operation produces a bench (contour
strip mining, auger mining arid highwall mining) all coal must be
picked up within thirty (30) days following removal of the over-
burden andjthe following requirements must be met.
(a) If the operation includes only stripping (no augering or
highwall mining), the grading and backfilling shall follow
the coal removal by not more than fifteen (15) days, but in
no instance shall an area be left ungraded more than 1,500
feet behind the removal of the coal.
(b) If the operation includes stripping and augering, the augering
shall follow the stripping by not more than sixty (60) days
and the grading and backfilling shall follow the augering by
not. more than fifteen (15) days, but in no instance shall an
area be left ungraded more than 1.500 feet behind the augering.
(c) If the operation includes stripping and highwall mining, the
highwall mining shall follow the stripping within a reasonable
time as determined by the Division in accordance with the pro-
vision of KHS 350.093 (5) and the grading and backfilling shall
follow the highwall mining by not more than fifteen (15) days.
but in no instance shall an area be left ungraded more than
1.300 feet behind the highwall mining.
267
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(d) If the operation includes only angering or highwall mining,
the grading and backfilling shall follow the augering or high-
wall mining by not more than fifteen (15) days, but in no
instance shall an area be left ungraded morei than 1,500 feet
behind the augering arid highWall mining.
(e) Modifications to these requirements may be made by the Division.
(3) If heavy rains or wet conditions make grading impracticable the
period of time required to be current shall be reasonably extended.
268
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APPENDIX H
TREATMENT OF PONDS AND PITS FILLED WITH ACID MINE DRAINAGE
Source: R.D. Hill, Chief, MPCB, NERC, Cincinnati, Ohio
INTRODUCTION
During surface mining, ponds, final pits or cuts, and other bodies of
acid mine drainage water are sometimes formed. This section explains several
methods of neutralizing acid water with lime either in place or before
discharging it. Other neutralizing agents besides lime can be used, however,
lime has been found to be one of the most effective with the least environmental
side effects.
DETERMINATION OF AMOUNT OF LIME
The first step in treating a body of water is to determine the acidity.
A representative sample of the water should be taken. For a small, shallow
body of water, one sample will probably be sufficient. For larger bodies of
water several acres in size, several samples at different locations should be
taken. Deep bodies of water are often stratified, with the poorest quality
water at the greatest depths. In such a situation, samples should be taken at
the deepest point in the pond at various depths.
For best results, the samples should be submitted to a laboratory for
analysis. An acidity determination should be made. In the case of deep
pits where the water is to be discharged, a ferrous iron determination should
also be made. The laboratory should report acidity results as milligrams per
liter (Mg/l) of acidity expressed as CaC03, and ferrous iron as Mg/1.
For large ponds, an average of the results for the various samples can be
used for determining the amount of lime required. For deep ponds, the average
of the samples can be used as a guide, or a calculation can be made for each
depth (see example h].
The volume of water in the pit or pond must be estimated. The easiest
method is to estimate the surface area of the pit or pond and the average
depth. The following examples are presented:
269
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Example 1
Estimated surface area 1.5 acres
Estimated average depth— U feet
Volume of water, Gallons= (acres) x (feet depth) x (325,850)
= (1.5) x (1») x (325,850)
= 1,955,100 gallons
Example 2
Pit is approximately 300 feet by 100 feet or 30,000 square feet
Estimated Average Depth is k feet
Volume of water, gallons= (surface area, sq.ft.) x (feet depth) x (7=5)
= 900,000 gallons
Using the following equation, the amount of lime required can be
determined:
Pounds of lime = (l|.67)x(conc. of acidity )x( volume of water/1,000,000)
x (I/purity of lime)
Examples are presented for the most common situations:
Example 3
Shallow pit or pond
Pit contains 10,000,000 gallons
Average acidity of water is 100 mg/1 as CaCO-
Purity of lime is 72 percent CaO
Pounds of lime = (I*.67)x(l00)x(l0,000,000/1,000,000)x(1/0.72)
Pounds of lime = (I.67)x(l00)x(l0)x(l.39)
Pounds of lime = 6,U91 or 6,500 pounds
Note:Acre = O.UO hectares; gallon = 0.0038 cubic meters
foot =0.30 meters; square foot =0.09 square meters
pound = 0.1+5 kilograms
Example k
Stratified deep pit
Sample A, taken at 5-foot depth; represents a depth of 0-10 feet; acidity =125mg/l
Sample E, taken at 15-foot depth; represents a depth of 10-20 feet; acidity
= 300 mg/1
Sample C, taken at 25-foot depth; represents a depth of 20-28 feet bottom;
acidity = 500 mg/1
270
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The 0- to 10-foot depth covers an area of 3 acres and thus would require:
Volume of water = (3)(lO)(325,850) = 9,775,500 gallons
Lime purity = 70 percent CaO (off bag)
Lime required = 0*.67)x(l25)x(9,775,500/l,000,000)x(l/.70)
- (U.67) x (125) x (9.78) x 1.U2
= 8100 pounds of lime
The 10- to 20-foot depth covers an area of 2 acres and thus would require:
Volume of water = (2)(10)(325,850) = 6,517,000 gallons
Lime required = (k.67)x(300)x(6,517,000/1,000,000)x(l/.70)
= 12,965 or 13,000 pounds of lime
The 20- to 28-foot depth covers an area of 1.2 acres and thus would require:
Volume of water = (l.2)(8)(325,850) = 3,128,160
Lime required = (U.67)x(500)x(3,128,l60/l,000,000)x(l/.70)
= 10,372 or 10,1*00 pounds of lime
Total Lime Required = 8100+13,000+10,^00 = 31,500 pounds.
Warning: In deep ponds and pits and in some shallow pits, the spoils adjacent
to the pit contain large volumes of acid water. When the water level in the pit
is drawn down, the acid water in the spoils flows into the pit. Thus, a larger
volume of water than expected may have to be treated.
For small ponds, or where laboratory facilities are not available, a field
test can be made which, although inaccurate, may still serve as a useful guide
for determining the amount of neutralizing chemicals required. A gallon con-
tainer, a sample of lime, and pH paper, meter, or color comparator are needed
for the test.
A half-gallon sample of the acid water is placed in the gallon container.
A known weight of lime is added to the sample and shaken. After allowing the
sediment to settle, the pH of the supernatant water is determined. This
procedure is continued until the amount of agent to bring the pH to 7<5 is
determined.
Example 5
Determining Lime Requirement by Estimation
A. Making up test lime slurry
Into 1 gallon of tap water (not acid water) place 1 level tablespoon of
lime (or any other neutralizing agent to be used), and shake well.
B. Place h gallon of acid mine water in a 1-gallon container. Add 1 table-
spoon of lime slurry and shake well, measure pH. Continue this step until
pH reaches 7 to 7-5-
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C. Determination of lime
Pounds of lime required = (number of tablespoons) (.OOOlM (gallons in pond)
For example, pond holds 10,000,000 gallons, and it took 10 tablespoons to
increase pH to 7.5.
Pounds of Lime required = (10)(.0001*0(10,000,000) = I1*,000
TREATMENT OF PONDS AND PIT INPLACE
Except for small pools of acid water, the broadcasting of lime on the
surface is an ineffective method of treating. The lime does not mix with the
water and settles to the bottom unreacted.
For inplace treatment, the best method is to draw acid water from near the
bottom of the pit with a pump. Attached to the suction end of the pump is a
small tube that runs to a tank of lime slurry. A valve in the tube will allow
adjustment of the amount of lime slurry added to the acid water. The pump
serves to draw water from the pond, and also to feed the lime slurry. In this
manner, the pump acts not only as a mixing device, but also as a feeder.
When treatment of the pit begins, the pH of the water discharging from
the pump should be about 9. As the pond becomes neutralized, it should be
reduced to 7-5. If possible, the pump should draw water from one end of the
pit and discharge to the other end. The discharge should be parallel to the
water surface and just above it. In this manner, the pump discharge sets up
currents in the pit and facilitates mixing. For very large pits, more than
one pump may be beneficial.
For small ponds, a discharge of a lime slurry near the propeller of an
outboard motor is an effective method. A tank of lime slurry is placed in the
boat, and a discharge tube is extended to the propeller area. The boat is then
driven around the pond while the lime slurry is discharged. The propeller
mixes the lime and water. An outboard motor can also be attached to a post
with the propeller facing out into the pond and the lime slurry fed near the
propeller.
TREATMENT OF PONDS AS THEY ARE EMPTIED
If a pond is to be treated as it is discharged, the iron content of water
is important. A laboratory analysis or a field analysis can be used to
estimate the iron content. If the iron' content exceeds 1 to 5 mg/1, the water
should be neutralized as dishcarged from the first pond and passed through a
second pond to allow the precipitated iron to settle.
272
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The acid water should "be pumped from the first pond. Lime can be fed by
the pump as discussed earlier. The second settling pond should have a
detention time of 12 hours except when the ferrous iron exceeds 50 mg/1, then
the residence time should "be 2.k hours. If the ferrous iron is very high, over
100 mg/1, the pH of the water as it leaves the pump should be 9-5 to 10, because
the ferrous iron will produce acidity as it oxidizes. For water with ferrous
iron less than 100 mg/1, pH should be 8 to 8.5.
273
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APPENDIX I
UNITS OF MEASUREMENT
TABLE 1. CONVERSION FACTORS FROM CUSTOMARY UNITS TO METRIC
Customary Units
Description
Symbol
Multiply
Multiplier
=Br
Symbol
To Get
Metric Units
Reciprocal
British thermal units per pound ....
Cubic foot
Foot
Gallon
Mile
Square yard
Ton , short
Yard
ac
Btu
Btu/lb
cu ft
cu in
cu yd
ft
gal
in
mi
oz
Ib
sq ft
sq in
sq mi
sq yd
ton
yd
0.404 7
1.055
2.328
0.028 32
0.016 39
0.764 6
0.304 8
3.785
25. 4
1.609
28.35
0.^53 6
0.092 90
645.2
2.590
0.836 1
0.907 2
0.914 4
ha
kJ
kJ/kg
m-^
1
m3
m
1
tirm
km
g
kg
m2
nun.
km2
m2
t
m
2.471
0.947 o
0.429 5
35.31
61.01
1.308
3.281
0.264 2
0.039 37
0.621 5
0.035 27
2.205
10.76
0.001 550
0.386 1
1.196
1.102
1.09^
TEMPERATURE CONVERSIONS:
°F « 9/5 (°C) + 32
°C = 5/9 (°F - 32)
27U
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TABLE 2. SYMBOLS FOR CUSTOMARY AND METRIC UNITS
Unit
acre
are
barrel
board foot
bushel
carat
Celsius, degree
centare
centigram
centiliter
centimeter
chain
cubic centimeter
cubic decimeter
cubic dekameter
cubic foot
cubic hectometer
cubic inch
cubic kilometer
cubic meter
cubic mile
cubic millimeter
cubic yard
decigram,
deciliter
decimeter
dekagram
dekaliter
dekameter
dram, avoirdupois
Symbol
acre
a
bbl
fbm
bu
c
°C
ca
eg
cl
cm
eh
cm
dm3
dam
ft3
hm3
in3
km3
m3
mi3
3
yd3
dg
dl
dm
dag
dal
dam
dr avdp
Unit
fathom
foot
furlong
gallon
grain
gram
hectare
hectogram
hectoliter
hectometer
hogshead
hundred weight
inch
International
Nautical Mile
kelvin
kilogram
kiloliter
kilometer
link
liquid
liter
meter
microgram
microinch
microliter
Symbol
fath
ft
furlong
gal
grain
g
ha
hg
hi
hm
hhd
cwt
in
INM
K
kg
kl
km
link
Hq
liter
m
PS
uin
Pi
275
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TABLE 2 (Continued). SYMBOLS FOR CUSTOMARY AND METRIC UNITS
Unit
mile
milligram
milliliter
millimeter
minim
ounce
ounce, avoirdupois
ounce, liquid
ounce, troy
peck
pennyweight
pint, liquid
pound
pound, avoirdupois
pound, troy
quart, liquid
Symbol
mi
mg
ml
mm
minim
oz
oz avdp
liq oz
oz tr
peck
dwt
liq pt
Ib
Ib avdp
Ib tr
liq. Qt
Unit
square centimeter
square decimeter
square dekameter
square foot
square hectometer
square inch
square kilometer
square meter
square mile
square millimeter
square yard
stere
ton, long
ton, metric
ton, short
yard
Symbol
cm
dm2
f\
dam
ft2
hm2
ZUU
O
£
2
u*
2
yd
stere
long ton
t
short ton
yd
276
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-670/2-74-093
2.
3. RECIPIENT'S ACCESSIOP+NO.
TITLE AND SUBTITLE
ENVIRONMENTAL PROTECTION IN SURFACE MINING
OF COAL
5. REPORT DATE
October 1974 ; Issuing Date
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
Elmore C. Grim and Ronald D. Hill
8. PERFORMING ORGANIZATION REPORT NO.
. PERFORMING ORGANIZATION NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
10. PROGRAM ELEMENT NO.
1BB040;ROAP 21AFZjTask
02
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above
13. TYPE OF REPORT AND PERIOD COVERED
Final - Inhouse
14. SPONSORING AGENCY CODE
16. SUPPLEMENTARY NOTES
16. ABSTRACT
This report is the result of information obtained from a review of
related literature and assembled by personal inquiry and onsite exami-
nation of both active and inactive surface mining operations. Premining
planning is emphasized and particular attention is given to incorporat-
ing mined-land reclamation into the mining method before disturbance.
New mining methods that will maximize aesthetics and minimize erosion,
landslides, deterioration of water quality are discussed. Blasting
techniques and vibration damage controls are recommended. Methods of
land reclamation including spoil segregation, placement, topsoiling,
grading, burying of toxic materials, and revegetation are noted. Tech-
nology for the control of erosion and sediment in the mining area is
presented in detail. Guidelines for planning, location, construction,
drainage, maintenance, and abandonment of coal-haul roads are included.
Costs are given for different degrees of reclamation and remedial meas-
ures for controlling pollution from surface mines. Reduction in costs
through premining planning are cited. Water quality change is discussed
in detail. Preventive and treatment measures are recommended. Research
needs are listed as a separate section of the manual.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
*Coal, *Surface mining, *Strip min-
ing, Exploration, Mapping, Blasting,
Reclamation, Mining Research, Drain-
age, Access roads, Erosion control,
Cost analysis, Vegetation, Acidity,
PH control, Climatology, Earth hand-
ling equipment, Earth fills, Loams,
Arid land, Semiarid land, Water
.conservation. Hydro!
b.IDENTIFIERS/OPEN ENDED TERMS
c. cos AT I Field/Group
*Contour mining,
*Area mining, Acid
mine drainage,
Premining planning,
Environmental protec-
tion, Block cutting,
Revegetation
8G
8H
81
13B
8. DISTRIBUTION STATEMENT
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
291
RELEASE TO PUBLIC
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
7
U.S. GOVERNMENT PRINTING OFFICE: 1974-657-586/5310 Region No. 5-H
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