-------
SOIL STABILIZATION
Soil stabilization is the other means of pre-
venting soil erosion. Whereas runoff control
practices are designed to manage rainfall runoff
in a way that reduces its ability to cause soil
erosion, soil stabilization practices are designed
to protect the soil from the erosive action of
falling rain, ensuing runoff, and wind. Protec-
tive shielding of the soil surface from the full
force of impacting raindrops and the hydraulic
and abrasive action of moving'surf ace water and
wind is achieved by binding the soil particles
together to form a mass that is less easily dis-
placed, and by anchoring the soil in place. Well-
established vegetation, for example, performs
all of these functions. The leaves, stems, and
other above ground portions of vegetation, as
well as the organic litter that collects on the
ground surface, shield the soil surface, while
the roots bind and anchor the soil. Surface cov-
erings of straw, hay, woodchips, gravel, riprap,
jute netting, and other material also serve to
shield the soil. Other nonvegetative material,
such as chemical emulsions, can be used to bind
and anchor the soil particles.
Stabilization measures may be either vegeta-
tive or nonvegetative, and short term or long
term. Vegetative stabilization refers to the use
of different types of vegetation to protect the
soil from erosion. Nonvegetative stabilization,
on the other hand, refers to a multitude of prac-
tices that use materials other than vegetation
in preventing soil erosion. Keep in mind, how-
ever, that a combination of both vegetative,and
nonvegetative measures is often required.
Short-term stabilization, also termed tempo-
rary stabilization, refers to the use of practices
that provide protection for a short period of
time, usually less than 1 year. Long-term, or
permanent stabilization, involves the use of
long-lived vegetation or a durable material, such
as rock, concrete, or asphalt, to protect the soil
against erosion for more than 1 year.
Vegetative Stabilization
Provided proper care is taken in its establish-
ment, vegetation is the most beneficial and
durable soil stabilizer (fig. IV-19). It forms a
protective cover that shields the ground surface
from the direct impact of falling rain, and its
roots bind and secure the soil particles. As noted
earlier, it also controls runoff by slowing the
flow of water along the soil surface and by en-
abling the soil to absorb more water. By re-
ducing the amount of runoff and its speed of
movement, the ability of the runoff to carry
away detached soil particles is also decreased.
'i', '. J"11'." '* 'C ,*' rijf ,!ii',»o:lp '«ft'«yi;--..,' " sjt111' -rsM1.,^,:,!' ,
/il nil »^'ii, ... . - nl* .151(11'! 1 n H I ['III. V '• ""'" ' 1-'',! *r!JwL"'J* I1- '
s-• ";'"',: ,,;:'-,=, „;,:., •> !i««,,,
-------
Long-term vegetative stabilization is accom-
plished by the proper planting of various combi-
nations of grasses, legumes, shrubs, and trees.
The type and mixture of individual plant species
to be used will depend on soil and moisture con-
ditions, climatic conditions, erosional stresses,
and postmining land use. Selection and estab-
lishment of vegetation is discussed later in this
section.
Short-term vegetative stabilization involves
the use of low-cost, quick-growing perennial and
annual plants, usually grasses, to provide pro-
tection for a short period of time (fig. IV-20).
This form of stabilization is often used to pro-
tect stockpiled topsoiling material. It is also
used for temporary stabilization of spoil graded
in late spring or fall when .more, permanent
stabilization cannot be performed properly.
Vegetative establishment is covered later in
this section.
Nonvegetative Stabilization
Like vegetative measures, non vegetative
practices are used to reduce the susceptibility
of mine soils to erosion. It is difficult to separate
the two major types of stabilization, in that they
are often used together. An important point to
remember is that nonvegetative stabilization is
used to reinforce vegetative measures. Where
yegetation will provide adequate long-term soil
protection, long-term nonvegetative stabiliza-
tion is not required. Where vegetation will pro-
vide partial, protection, as is often the case in
areas subject to concentrated flow (such as
found in a drainageway), a combination of the
two types of stabilization is desirable. On the
other hand, should vegetation not be able to
provide any protection, such as on the bottom or
bed of a stream, nonvegetative stabilization is
the only protective treatment available (fig.
IV-21).
: Nonvegetative stabilization covers a wide
assortment of short-term and long-term soil
stabilization practices, which vary considerably
in their cost-effectiveness and ability to with-
stand erosional stresses. As a general rule, it is
probably best to stay with measures that have
proven successful in the field. New products or
practices appearing worthwhile and offering
.possible cost advantages should be demon-
strated on test plots before being employed
extensively.
ISrtPf. Wi"ft: iS^fS^w
mffifffwviJ&if *»i til4!it£:*i&;ffv=-!fc
ifisv^tK «
Figure iV-20. Outslope stabilized with short-term annual grasses.
39
-------
i.-oHMWfell)
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.i-^ai^^iBag
Figure IV-21. Newly seeded and mulched area adjoining ditch lined with stone riprap.
Short-Term Measures. Mulching and chem-
ical stabilization are two major types of short-
term, or temporary, nonvegetative soil stabiliza-
tion (fig. IV-22). Both are employed to provide
protection against excessive soil erosion for
periods of less than 1 year.
Mulching. Mulching with organic materials
such as straw, hay, woodchips, wood fiber, and
other natural and manufactured products is the
most popular means of providing short-term soil
stabilization. Mulch is used in the establish-
ment of a vegetative ground cover to protect
the seedbed from excessive erosion prior to
germination of the seeds and until the new vege-
tation is sufficiently established. The mulch
provides a favorable environment for seed ger-
mination and plant development. Mulches can
also be used in place of short-term vegetative
stabilization to protect temporarily against
excessive soil loss prior to the preparation of a
seedbed. Some mulch materials, in particular
straw and hay, require stabilization to prevent
them from being uncovered by wind and water.
This is accomplished by applying asphalt or
chemical tacks that bind the mulch material
together and to the soil surface or, in the case of
straw and hay, by crimping. When performed
along the ground contour, crimping is doubly
beneficial in that it produces a surface texture
that inhibits surface runoff.
In areas subject to concentrated flow, net-
tings of fiber glass, plastic, and other material
stapled securely to the ground may be required
to keep fibrous organic mulch material from
being removed. Jute netting is usually utilized
to stabilize drainageways. When properly in-
stalled, it is difficult to remove and, because of
its bulky and fibrous nature, it protects the soil
surface and provides a good environment for
seed germination.
Chemical stabilization. Chemical soil stabi-
lizers are designed to coat and penetrate the soil
surface and bind the soil particles together (fig.
IV-23). They are used to protect bare soil slopes,
not subject to traffic, from wind and water ero-
sion during temporary establishment of a seed-
bed. Chemical stabilizers are used both in lieu of
temporary mulch material and in conjunction
40
-------
'!< I,!///.
Figure \\l-22.\ Straw mulch.
^-; ;jr**g*;sg
?;'>>>.,/>•.
•• -*^ .••*%"'^f~ '.^^S^^ef^x^' ^^'^ ft ^> ^3
:" ! :r:*sfeaS~L3S5'5%*fe!i
'. , _; -. '^"'^"''X'^^f^Jjl?*1
""-VV- /^;^
Figure IV-23. Chemical stabilizer being applied over straw mulch.
with the material to act as a mulch tack and
soil binder.
Chemical stabilizers generally work best on
dry, highly permeable spoil, or in-place soils
subject to sheet flow rather than concentrated
flow. It is recommended that chemical soil stabi-
lizers be tested on small, representative plots of
ground before selecting a mixture of chemicals
and water and an application rate, or before
deciding to use these chemicals extensively in
stabilizing mine soils. As a general rule, chemi-
cal stabilizers do not provide protection for as
long a period of time as straw, hay, and other
organic mulches.
Section I, volume II, contains additional in-
formation on short-term stabilization measures
and products.
Long-Term Measures. Long-term, non-
vegetative soil stabilization is required when
vegetation alone cannot withstand the erosional
stresses imposed by surface runoff and when
vegetation is not adaptable to the chemical,
moisture, or traffic conditions occurring in the
soil or on the surface to be stabilized. Areas at
surface mines requiring such treatment include
roadbeds, waterways, and toxic or excessively
wet soil surfaces.
Long-term measures include nonstructural
practices, like mulching, and structural prac-
tices, such as paving, channel lining, and grade
control.
Mulching. Mulching practices involve the use
of nonbiodegradable material, such as fiber
glass and various plastics, to protect seedbeds
41
-------
during the critical germination and early plant
development period, and to act as a reinforce-
ment following establishment of the vegetative
cover. These materials include nettings and
loose, stringy products that, when applied to
the seedbed, become securely enmeshed in the
vegetation at the ground surface and in the
rootmat. Light applications of crushed stone or
gravel will perform a similar function.
Stone surfacing. To stabilize highly toxic
surfaces, or excessively wet seepage areas on
slopes, a heavy application of durable crushed
stone, gravel, clinkers, or "red dog" is often
warranted. The best cure for these problems, of
course, is to dispose of the overburden and man-
age the drainage in a manner that prevents such
problems from occurring.
Crushed stone, gravel, clinkers, and red dog
also are used to surface roadways (fig. IV-24).
In addition to securing the soil, such treatment
increases the bearing capacity of the roadway,
provides for continuous all-weather use, and
decreases the likelihood of traffic damage and
related accelerated soil erosion.
Channel stabilization. Channel stabilization
is usually not as complex a problem at surface
coal mines as it is at large, urban construction
sites. For the most part, structural stabilization
practices involve the use of stone riprap and
other durable material to stabilize ditches and
other manmade waterways. Where natural
streams are severely affected by mining, either
due to disturbance of the channel or increased
surface runoff, sophisticated and costly struc-
tural measures are often required to protect the
channel from erosion.
Channel stabilization structures are used to
maintain channel alignment (i.e., prevent ero-
sion of the sides of the channel) and/or maintain
channel gradient (i.e., prevent scour of the chan-
nel bottom). Revetments and check dams are
the structures most commonly used at mines to
prevent channel erosion. Revetments are de-
signed to shield the channel from the hydraulic
and abrasive action of concentrated flow. Gener-
ally, these structures are built of stone riprap
obtained from the mine site and placed in the
bottom of the channel at critical locations to
prevent down-cutting. Where the sides of the
channel cannot be stabilized with vegetation
alone, the stone is carried up the sides of the
channel to form a complete channel lining. The
stone riprap should be sandstone, limestone, or
other durable rock of a size that cannot be re-
moved by the runoff. Large voids between rock
fragments should be clinked with smaller frag-
ments to provide a dense cover. When heavy or
sustained flows must be handled, a graded sand
and stone filter, or filter cloth, should be placed
under the structure, securely against the soil
* "* ,~t
t " *'-,:!*
Figure IV-24. Access road with aggregate surface.
42
-------
surface to prevent the upward movement of soil
particles due to hydraulic action. Wire baskets
filled with stone (gabions), various concrete
blocks, bags filled with a mixture of sand and
cement, and nylon mattresses filled with a sand/
cement grout (Fabriform® ) are also used to con-
struct revetments in waterways (fig. IV-25).
These products and materials are generally only
used to stabilize highly critical areas, such as
natural streams or stream realignments. Where
good riprap stone is not available at the mine
site, cost considerations may warrant the use of
certain material in ditches and other areas in
place of stone riprap.
For environmental and esthetic reasons and
to minimize maintenance requirements, vegeta-
tion should be used with structures whenever
possible. Where sustained, heavy flow is not
present, revetments constructed of loose stone
riprap, or thin, stone gabions provide an environ-
ment for the growth of vegetation within the
armored portion of the channel.
Revetments required to protect critical areas
in stream channels, and occasionally subjected
to heavy flow, should be designed by an engineer
and be installed in accordance with construction
specifications.
Unlike revetments, which can be used to pro-
tect the entire channel or its sides or bottom,
check dams are designed to protect only the base,
or bottom, of the channel from erosion. These
structures are placed across the channel at inter-
vals along the alignment to inhibit physically
the moving water from eroding the bottom of
the channel. They generally consist of a rela-
tively narrow strip of stone riprap laid across
the channel. Logs and lumber are also used to
construct check dams. At surface mines, these
structures are used to control erosion in ditches,
and other constructed drainageways, having
steep gradients or long grades.
Additional information on long-term non-
vegetative measures can be found in sections I
and 11, volume II.
Areas To Be Stabilized
All areas that are in any way disturbed by the
mining operations must be stabilized. Water-
ways that will have to handle increased flows
Figure IV-25. Stonej gabion structure.
43
-------
may also need to be stabilized. However, the
major emphasis in stabilization must be placed
on three critical areas that are particularly sus-
ceptible to erosion—roadways, fill slopes, and
stream channels.
Roadways. Roadways are a major source of
sediment at surface coal mines. Haul roads at
contour mining operations are a particular prob-
lem since much of the drainage and runoff from
the bench and other disturbed areas make their
way to the haul road. Roadside ditches, safety
berms, inlets, outlets, cut-and-fill areas, and the
actual road surface are extremely susceptible to
erosion.
Water-tolerant and erosion-resistant vege-
tation should be used for stabilizing roadside
ditches. However, where high velocities are en-
countered, dumped or placed stone riprap will
provide additional long-term protection. Culvert
inlets and outlets also require a layer of stone
riprap or other resistant, energy-dissipating
material.
Safety berms present several problems. Stabi-
lization with vegetation and, in some instances,
other material is necessary to reduce soil losses.
Roads should be pitched away from the berm,
toward the cut slope, to avoid undercutting by
water. The berm should be properly compacted,
and, when concentrated water is handled, rock
mulches should be used to provide temporary
stabilization until a vegetative cover can be
established.
Road surfaces should be stabilized by using
nonvegetative material such as rock aggregate,
clinkers, red dog, or other durable material that
can slow down water and withstand truck, traf-
fic. This stabilization is also important for
controlling dust on haul roads.
Slopes. Prompt and effective stabilization of
cut-and-fill slopes is especially important in con-
trolling soil erosion. Cut slopes greater than 2:1
(50 percent) place severe limitations on the
ability of plant roots to hold and bind soil par-
ticles. As a rule of thumb, a 2:1 slope is assumed
to be the maximum slope upon which vegetation
can be established and maintained satisfactorily.
However, maximum vegetative stability cannot
be attained on slopes steeper than 33 percent
(3:1). The maximum-slope rule should only be
applied to ideal soil conditions where the soil is
not highly erodible and has adequate moisture-
holding capacity. In situations where vegetative
measures, such as grasses and legumes, fail due
to slope steepness, a blanket of crushed stone or
other durable material will be required to stabi-
lize the soil.
Fill material can be manipulated as previously
discussed so that excessive slope lengths and
steepness are avoided, thus improving, the
chances for soil-holding vegetation to become
established. Fill slopes should remain accessible
to maintenance equipment. Seeding of cut-and-
fill slopes should follow closely behind the grad-
ing operations. Large boulders and rocks and
debris can be located at the toe of the fill slopes
to provide support and reinforcement. This will
provide a more uniform slope, and make it less
susceptible to voids where fills and gullies can
form. Scalped material can be windrowed in
front of the toe to act as a filter for sediment.
Stream Channels. Waterways downstream
from surface mining operations are sometimes
subjected to large increases in the volumes of
surface runoff. These large volumes of surface
runoff and the associated increases in velocity
render the waterway highly susceptible to ero-
sion.
Vegetative measures for stabilizing banks of
stream channels involve the use of select grasses
and legumes that are tolerant of wet conditions
and resistant to high water velocities. Table
IV-3 gives the maximum permissive velocities
for various types of vegetative channel linings.
In certain places within waterways, vegeta-
tive practices alone are not enough to prevent
erosion. Structural devices must be used to pro-
tect the waterway from scour or erosion.
Critical areas along streambeds that may
need structural stabilization include the outside
of bends where the flow impinges or impacts
against the streambank, restrictions in the chan-
nel, junctions where tributaries enter the main
channel, and places where the channel gradient
is excessive (fig. IV-26).
Revetments are useful in areas where it is
necessary to protect the streambanks. The
material most commonly used for this purpose
is stone riprap, which is durable, heavy, and
flexible. Also, it generally is readily available at
many mine sites. Gabions and revetment mat-
tresses are also often used. In addition to these
materials, MONOslabs™, poured concrete, con-
crete block, and sandbags filled with a sand-
cement mixture are sometimes used. The use of
these materials is discussed in volume II.
In some areas, it may be necessary to protect
the streambed as well as the streambanks.
Grade control structures are used for this pur-
pose. These structures physically prevent the
streambed from being eroded and slow the flow
of water.
A grade control structure consists of durable
material placed, on the bottom of the channel.
It can be a narrow strip of riprap stone placed
across the channel, or it can be a complete lining
of the channel (fig. IV-27). Materials used to
construct revetments are also used to build
grade control structures. Common uses of grade
44
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control structures include riprap energy dis-'
sipators placed at outfalls of stormdrains; rip- i
rap check dams placed at regular intervals along I
a waterway; and revetments of riprap, concrete,
gabions, Fabriform®, or other material for lining
streams and drainageways.
VEGETATIVE ESTABLISHMENT
The revegetation of mine spoils and other
disturbed areas using, for the most part, soil-
binding grasses and legumes, is one of the most
important means of preventing excessive soil
erosion at active mine sites. However, the effec-
tiveness of vegetation in stabilizing the soil will
be limited unless existing and future site condi-
tions are adequately assessed in the selection
of plant material and proper establishment prac-
tices are followed.
Plant Selection
Each plant species has its own growth charac-
teristics that determine its value in stabilizing
soil. Grasses and legumes are the most effective
plant materials for controlling erosion in the
early stages of reclamation. However, they are
short-lived species and are generally planted in
combination with trees and shrubs. Trees and
shrubs are not very effective in controlling ero-
sion in the early stages because of their initial
slow development. But, during the middle and
late stages of reclamation, as the grasses and
legumes die off, the trees and shrubs form a
protective canopy and provide a necessary build-
up of surface organic material as a result of the
leaf litter, which is excellent in controlling sur-
face runoff and erosion. In addition, trees and
shrubs are beneficial for screening, wildlife, and
forestry purposes.
Grasses. Grasses are particularly well suited
for stabilizing mine spoil and other exposed
areas at a mine. They are highly adaptable to
various site conditions and provide a quick,
dense, and lasting ground cover. Furthermore,
the dense, fibrous roots of grasses securely
anchor the soil and allow surface water to infil-
trate more rapidly. Grasses commonly used in
stabilizing mine spoil include tall fescue, weep-
ing lovegrass, and redtop. Other grass species
and their characteristics are given in table IV-4.
Among grass species, a high degree of adapt-
ability to various site conditions exists. Species
are available for different exposure (sunlight,
temperature, and wind) conditions, and for
planting during the spring, summer, and fall.
Some species are highly tolerant of wet soils,
while others do well on dry, droughty soils.
Table IV-3.—Maximum permissible velocities in channels
lined with uniform stands of various grass covers,
well maintained3
COVGT
Bermudagrass . . .
Buffalograss ... \
Kentucky bluegrass . . 1
Smooth brome . . . . /
.... i
Blue grama ... 1
Grass mixture ..'...
Lespedeza sericea . . . \
Weeping lovegrass . . . J
Yellow bluestem . . . . (
Kudzu .... /
Alfalfa . . I
1
Crabgrass . '. . . /
Common lespedezad . . |
Sudangrassd (
Slope range
Percent
( 0-5
< 5-10
. | Over 10
!'
0-5
• 0-15
Over 10
.
. f bO-5
< K
1 b5-10
cO-5
cO-5
Maximum
permissible
velocity on:
Erosion- Easily
resistant eroded
soils soils
ft/s ft/s
8.0 . 6.0
7 fi EI n
' .U O.U
6.0 4.0
, 7.0 5.0
6.0 4.0
5.0 3.0
5.0 4.0
- 4.0 3.0
3.5 2.5
3.5 ., 2.5
aUse velocities over 5 ft/s only where good covers and
proper maintenance can be obtained.
bDo not use on slopes steeper than 10 percent.
cUse on slope steeper than 5 percent is not recommended.
Annuals; used on mild slopes or as temporary protection
until permanent covers are established.
Source: Design Charts for Open-Channel Flow, Hydraulic
Design Series No. 3' U.S. Department of Transportation,
Federal Highway Administration, Washington, D.C. Aug.
1961.
The ability of many grasses to spread them-
selves by surface and underground runners
(stolons and rhizomes) is another important
aspect. Given time and proper maintenance,
these grasses are able to heal minor, breaches
in the ground cover resulting from erosion, plant
disease, and other factors.
Legumes. Legumes are commonly used in
surface mine areas in combination with various
grasses. They are important because of their
ability to take nitrogen from the air and store it
in their roots. This stored nitrogen can be made
available to nbn-nitrogen-fixing plants, such as
grasses, and assist in their growth.
-------
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ii!,i,a .!;: ..•. .• 'I!1".1, j. • ..•'•• *i*i! *'
igfifjf
i.:,, M1* i* '«B#a3^l&fc*S^tsil» Jte ,Vaifert; 4fefe$S'
ai-;rk,*f»t«lK?^ies^i
a «•_-.. '••te;X. * fif. Vs '>'»*'? SiiF^;8"F'"*lti"*l'?*;'fti« •-
. -- ' "',,. J'11',- |w5b ,»f*t "'j-*A#ii!1 S r^ ii,"i * S^ -'."i^'.-^Sf&^M
. " * -**> • 3h. 2rf3l *-r,i ni fc „ \JU..^ .• ,,,***,*• W4*t&tam>M
" "f « ::". '";,|'V','Of
Figure IV-26. Stone riprap protecting bends in stream.
Figure IV-27. Riprap check dam (grade control structure) placed in a drainageway.
46
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nse root system; grows in a clump to 3 feet tall. More
drought tolerant than big bluestem. Good surface pro-
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conditions. Can withstand draught; good for wet condi-
tions. Spreads by rhizomes.
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spoil. Temporary cover.
Excellent for temporary cover. Can be established under dry
.and. unfavorable conditions.. Quick getminatlon; rapid
seedling growth.
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Good for wet, alkaline areas. Tolerant of saline conditions.
Sod forming. Easy to establish.
Sod forming, spreads rapidly, slow germination. Valuable for
erosion control. Drought resistant.
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Legumes have a large taproot that extends
deep into the soil and enhances both soil stabili-
zation and infiltration (fig. IV-7). When legumes
. are planted, less nitrogen fertilizer is required
to maintain the ground cover. Nitrogen is usu-
ally very deficient on most surface mine spoil
and is needed to establish legumes. Before
legumes are planted, the seed should be treated
with the proper inoculant to insure the presence
of nitrogen-fixing bacteria needed to carry out
fixation. Inoculating bacteria for particular
legumes are commercially available.
Legumes commonly used with grasses in
stabilizing mine spils include sericea lespedeza,
crownvetch, clovers, and birdsfoot trefoil. Other
legumes that are commonly used for revegeta-
tion are given in table IV-5.
Shrubs. Various shrubs are available for
planting on surface-mined areas. Although they
are primarily useful as wildlife habitats and for
esthetic purposes, some species have been devel-
oped that can help to stabilize the soil. Bristly
locust can be applied directly with a hydro-
seeder. It provides good surface cover and is a
rapid thicket former on acidic spoil. Another
advantage in using locust is that it is a legume.
Other commonly used shrubs include autumn
olive and amur honeysuckle, in addition to those
listed in table IV-6.
Trees. Trees have limited uses as soil stabi-
lizers during early periods of growth. Their
shallow, nonextensive root system, as well as
their slow and upright growth habit, severely
limits their effectiveness in stabilizing soil.
Trees should be used in combination with grasses
and legumes to provide long-term protective
cover. The grasses and legumes provide the
necessary protection in the early years while the
trees develop their protective canopies and build
up a stabilizing litter of dead leaves on the
ground.
Once established, trees can provide an effec-
tive screen as well as a habitat for wildlife. Trees
also represent a renewable, marketable natural
resource. . ,
Selection Criteria. In selecting plants for
erosion control, the following criteria should be
considered:
• Their ability to withstand the erosive and
traffic stresses present at the area being •
stabilized
• Their adaptability to existing soil conditions
(pH, moisture, texture, and fertility)
• Their adaptability to climatic condition (sun- ,
light exposure, temperature, wind exposure,
rainfall) found at the site -- • - -
• Their resistance to insect damage and diseases
• Their adaptability to the postmining land use ••
• Their compatibility with .other plants selected
for use on the same area
• Their, ability to propagate (either by seed or
• vegetatively) themselves
• Their maintenance requirements
To minimize the possibility of failure in estab-
lishing a plant cover and at the same time reduce
postestablishment maintenance requirements,
select plants that are adaptable to the natural
conditions found at the site:
The characteristics of grasses, legumes,
•> shrubs, and trees commonly used in revegeta-
" tiori of mine spoils .and other denuded areas at
mines are summarized in tables IV-4, IV-5, and
iv-6. ; •
Seedbed Preparation
Grasses and legumes used in revegetating
mined areas are established by direct seeding on
a properly prepared seedbed (fig. IV.-28). Woody
plants, such as shrubs and trees, are established "
by seedling. However, some species can be di-
rect seeded. Whatever technique is used, most
mine soils require ameliorative treatments be-
fore planting. It is recommended that the topsoil
to be vegetated be analyzed to determine the
proper lime and fertilizer requirements. Various
problems and required treatments are as fol-
lows:
« Acidity (low pH): Lime and tbpsoiling mate-
rial should be applied to increase,the pH to
5.5 if possible.
• Low fertility: Fertilizers should be added to "
provide required plant nutrients as deter- .
mined by the soil test.
• High surface temperatures: Black spoil mate- ...
rials should be covered to prevent high,
seedling-killing temperatures. - " r
« Excessive rockiness; Large rocks and boul-
ders should be removed and buried deeply in
the pit or used for riprap in waterways.
« Droughty soils: Use drought-tolerant plants, -
mulches, fine-grained topsoiling'; material,
and organic additions.
0 Topsoil: The surface or subsurface soil mate-
rial most suitable for plant growth should be
used. Selective stockpiling of material may •
"be required.
• Wet soils: Provide good surface drainage and
plant moisture-tolerant vegetation. Possibly
use a rock blanket or long-term mulch mate-
'"- rial in combination-with vegetation. -,,
• Dense, poorly permeable soils: Loosen soilby
•scarification or "tillage. For clayey soils, also
add lime to loosen soil structure or cover
; with, a more desirable soil. -;
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Table \\J-Q.-Commonly used trees and shrubs
Common name
Shrubs:
Amur honeysuckle
Bristly locust
Autumn-olive
Bicolor lespedeza
Indigo bush
Japanese fleeceflower
Silky dogwood
Tatarian honeysuckle
Trees, conifers:
Virginia pine
Pitch pine
Loblolly pine
Scotch pine
Shortleaf pine
White pine
Austrian pine
Japanese larch
Red pine
Rocky Mountain juniper
Eastern red cedar
Mugho pine
Trees, hardwoods:
Black locust
Bur oak
Cottonwood .
European black alder
Green ash
Hybrid poplar
Red dak •.
European white birch
Sycamore
Scientific name
Lonicera maacki
podocarpa
Ftobinia fertilis
Elaeagnus umbeltata
Lespedeza bicolor
Amorpha fruticosa
Polygonum cuspidatum
Cornus amomum
Lonicera tatarica
sib erica
Pinus virgin/ana
Pinus rigida
Pinus taeda
Pinus sylvestris
Pinus echinata
Pinus strobus
Pinus nigra
Larix leptolepis
Pinus resinosa
Juniperus scopulorum
Juniperus virgin/ana
Pinus mugo mughus
Robinia pseudoacacia
Quercus macrocarpa
Populus deltoides
Alnus glutinosa
Fraxinus pennsylvanica
•--<
Populus spp.
Quercus rubra
Betula pendulata
Platanus occidentalis
•- ' " ' • '.
i Remarks
i • '
Good' for wildlife. Shows more vigor and adaptability as plants mature.
1 '
Extreme vigor. Thicket former. Good erosion control. Rizornatous, 5-7
ft tall. Excellent on flat areas and outslopes.
Nitrogen-fixing nonlegume. Good for wildlife. Excellent fruit crops. Wide
adaptation. Up to 15 ft tall.
Can be established from planting and direct seeding. Ineffective as a ground
cpv|er for erosion control.
Has high survival on acid spoil. Leguminous. Not palatable to livestock.
Thicket former. Slow spreader. 8-12 ft tall.
Grows well on many sites, especially moist areas. Excellent leaf litter and
canbpy protection, :pH range of 3.5 to 7.0.
Grows best on neutral spoil pH. Can withstand pH range of 4.5 to 7.0.
Sorpe value as wildlife food and cover plants. Poor surface protection.
Upright shrub, forms clumps. Does well on well-drained soils. Up to 12 ft
tall Takes 2 years for good cover.
Tolerant of acid spoil. Use for esthetics and where other species will not
survive. Slow development. Good for wildlife.
Deep j-ooted and very acid tolerant. Can survive fire injury. Deer like small
seedlings. Plant in bands or blocks.
Very promising species, rapid early growth. Marketable timber products.
Cap survive pH 4.0 to 7.5. Susceptible to ice and snow damage.
Good for Christmas trees if managed properly. Can be planted on all slopes
and tolerates pH of 4.0 to 7.5.
Some insect problems. Will sprout freely if cut or fire killed when young.
Good marketable timber.
Maybe used for Christmas trees. Has poor initial growth but improves with
time. Plant in bands or blocks.
Can b£ planted on all slopes. Plant in bands or blocks. When planted near
black locust, deer cause browse damage.
Should be planted on unleveled and noncompacted spoil. Provides good
litter.
Sawfly damage in some areas. Plant on all slopes. Light ground
cover.
Has shjown good survival on Kansas spoil materials. Compact growth varie-
tiesfhave from silver to purple colors. -
Tall, narrow growth. Best on dry, sandy soils. Good with black locust. pH
,5.0 to 8.0.
Survives on acid spoil. Develops slowly. Low growing. Good cover for
wildlife.
Can be direct seeded. Wide range of adaptation. Rapid growth; good leaf
litter. Use mixed plantings. Dominant stem clones preferred.
Better survival with seedling transplants than acorns. Light to heavy ground
cover.
A desirable species for large-scale planting. Good cover and rapid growth.
Pure stands should be planted.
Rapid growing. Wide adaptation. Nitrogen fixing, nonlegume. Can survive
pH 3.5 to 7.5. Adapted to all slopes.
Very promising species. Use on all slopes and graded banks with compact
• loarns and clays. Plant in hardwood mixture.
Rapid growth. Good survival at low pH. Marketable timber after 20 years.
Cannot withstand grass competition. Good for screening:
Makes slow initial growth. Good survival, plant on upper and lower slopes
only. Can grow from pH 4.0 to 7.5.
Makes rapid growth on mine spoil. Poor leaf litter and surface cover-
age.
One of the most desirable species for planting. Poor ground cover. Volun-
teer trees grow faster than planted ones. , •
51
-------
Preparation Practices. To obtain a rapid
and successful growth of vegetation, the follow;-
ing practices should be followed:
• When required, topsoiling material should be
spread to a depth of 15 to 30 cm (6 to 12
inches). The spoil surface should be-rough-
ened before the material is applied so that a
sound bond can be formed.
• Where terrain permits, soil material should be
worked by discing, harrowing, or other means
to break up large clods and eliminate any
surface crusting. Commercial rock pickers
are effective in removing rock and debris,
which often prevent good seedbed prepar^-
tion. On steep slopes where equipment travel
is limited and aerial seeding or hydroseeding
is performed, the surface soil should be pre-
pared with commercial pick chains, by drag-
ging a cleated dozer track or other device
along the slope, or by running a cleated dozer
up and down the slope.
• Application rates for lime and fertilizers
should be determined from soil tests. Where
terrain permits, the lime should be worked
into the soil to a depth of about 15 cm (6
inches) by discing or harrowing. Highly acidic
soils (pH below 4.0) will require extra lime.
• Seeding should be performed as soon as pos-
sible after final grading or application of
topsoiling material. Surface soil crusting
resulting from delays in seeding can result in
poor seed germination and loss of seed due to
wind action and surface runoff.
• Mulches should be applied immediately after
seeding to promote growth and provide tem-
porary stabilization. Mulch crimping is an
effective means of securing mulching mate-
rial, especially on steep slopes and in areas
where wind is a problem.
pH and Liming. The primary factor limiting
plant growth on surface mine spoil is acidity,
which is often expressed as pH.
The pH of a soil is a numerical measure of the
acidity (sour) or alkalinity (sweet) of the soil
(fig. IV-29). On a scale of 1.0 to 14.0, acid values
range from 1.0 to 7.0 with 1.0 being the most
acidic and 7.0 being neutral. Alkaline values
range from 7.0 to 14.0, with 14.0 being the most
alkaline.
The acidity of most surface mine spoil limits
the number of plant species that can be planted.
Some plants, such as weeping lovegrass, can be
planted on spoil with a pH as low as 4.0. How
ever, other species, such as K-31 tall fescue,
require a pH of no lower than about 5.0 before
good growth can be obtained. Legumes gener-
ally require a higher pH than grasses.
Lime is used to correct acidic soil conditions
and enhance the availability of soil nutrients,
such as phosphorus and magnesium. Some nu-
yef ;#•»"", *s- "_i •"••„ ',,(»' t&i&fy, *?&••*
Figure IV-28. Well-prepared seedbed.
52
-------
ALKALINITY
RANGE
ACIDITY
RANGE
DEGREE
Strong
Moderate
Mild
Neutral
Slight
. . f
Medium
Strong
Very strong
Extreme
PH
VALUES
8.0
7.0
6.0
5.0
4.0
3.0
OPTIMUM
RANGE
FOR
MANY
CROPS
FEW
KINDS
OF
PLANTS
THRIVE
Figure IV-29. pH scale.
T
trients become available with increased pH,
while other elements, which are toxic to plants
at low pH levels, become unavailable. When
liming acidic spoil, the rates applied should be
based on soil tests. When samples are collected
for laboratory analysis, subsoil (below 15 cm, or
6 inches, in depth) and surface soil (top 15 cm,
or 6 inches) samples should be taken. This will
insure that sufficient lime will be applied to
counteract current and future acidity.
Table IV-7 contains the approximate liming
rates required to increase the pH of various
tested soils to 4.5 to 5.0, 5.0 to 5.5, and 5.5 to
6.O.4 These figures should only be used as ap-
proximates. Soil samples should be taken and
analyzed for accurate rates.
When purchasing and applying agricultural
lime to spoil material, the following factors
should be understood:
• Common agricultural limestone or ground
limestone is the most common liming mate-
rial for correcting spoil acidity. Limestone
may consist mainly of calcium carbonate
(CaCO3), or it may contain both calcium car-
bonate and magnesium carbonate (MgCO3).
Limestone that contains about as much mag-
nesium carbonate as calcium carbonate is
153
-------
Table IV-7.—Agricultural lime needed to increase surface mine spoilpH to specified level3'**
Spoil pH test
Less than 3.0 . .
3.0 to 3.5 ....
3.5 to 4.0 ....
4.0 to 4.5 ....
5.0 to 4.5 ....
Tons lime needed per acre to increase pH to
4.5 to 5.0
Stabilization and erosion control
6 to 8 or more
3 to 5 or more
2 to 3
1 to 2
5.0 to 5.5
Medium forage production
8 to 10 or more
5 to 7 or more
3 to 5
2 to 3
1 to 2
5.5 to 6.0
High forage production
10 to 12 or more
7 to 9 or more
5 to 7
3 to 5
1 to 3
*Rate per acre is based on lime having a neutralization value of 100 and affecting a 15-cm (6-inch) depth.
bThese figures are only an approximate. Soil samples should be taken and analyzed for accurate rates.
Source: Guidelines for Reclamation and Revegetation, Surface-Mineral Coal Areas in Southwest Virginia, Virginia Polytechnic
Institute and State University, Extension Division, Feb. 1973.
called dolomite. Limestone containing lesser
proportions of magnesium carbonate is called
calcitic or magnesian limestone. Other liming
materials include quicklime, hydrated lime,
chalk, marl, and fly ash. Rock phosphate is
high in calcium and has some neutralizing
effect on acidic spoil in addition to providing
phosphorus.
The total capacity of lime to correct acidity,
or the neutralizing value, is measured by the
calcium carbonate equivalent.
The size of the particles of the liming material
is usually the best guide to the rate at which
soil acidity can be corrected. The smaller the
particles are, the faster the lime can correct
acidity. The coarser the lime particles, the
less reactive the material.
The ideal time for lime application is 6 months
prior to seeding. When this is not possible,
the finest ground limestone should be pur-
chased and thoroughly mixed with the soil as
far in advance of seeding as possible.
Lime should be applied immediately after
grading, regardless of season, and worked
into the spoil to a depth of 15 cm (6 inches).
On extremely acidic spoil, lime should be
applied to a depth of 25 to 30 cm (8 to 12
inches). In this event, additional lime will be
required.
Lime can be applied by truck, tractor-drawn
spreaders, and by hand broadcasting. On
steep outslopes, lime can be applied by rear-
mounted blowers attached to liming trucks.
• Maintenance liming may be required in the
third or fourth season following the initial
application, based on soil-testing recom-
mendations.
Fertilizing. Most surface mine spoil is defi-
cient in plant nutrients such as nitrogen, phos-
phorus, and sometimes potassium, which are
needed for plant establishment and sustained
growth. Prior to the use of any fertilizer, soil
samples should be taken and analyzed by State
or commercial soil-testing laboratories experi-
enced in mining soils and spoils. Fertilizers
should be selected based on the results and on
the recommendations of the lab.
Fertilizers are labeled according to their nitro-
gen (N), phosphate (P2O5), and potash (K2O)
content. These values are given in percent or
pounds per 100 pounds of fertilizer. This is called
the fertilizer grade. For example, the grade
5-10-10 contains 5 percent N, 10 percent P2O5,
and 10 percent K2O. Likewise, an 0-20-20 fertil-
izer contains no N, 20 percent P2O5, and 20 per-
cent K2O.
When a soil test recommendation calls for 25
pounds of N, 50 pounds of P2O5, and 50 pounds
of K2O per acre, a fertilizer with a 1-2-2 ratio
(twice as much P2O5 or K2O as N) is needed.
This ratio can be provided by using a 5-10-10-,
6-12-12-, 8-16-16-, or 10-20-20-grade fertilizer.
If a 5-10-10 grade is chosen to supply 25 pounds
of N, 50 pounds of P2O5, and 50 pounds of K2O,
the first number of the grade (5) is divided into
54
-------
the N recommendation (25) and the result mul-
tiplied by 100, as shown below, to arrive at th'e
amount of fertilizer required per acre. j
25/5 = 5 x 100 =500 Ib/acre of 5-10-10 |
to supply 25 Ib N, j
501bP2O5,and501bK2O !
I
Higher analysis, or "straight" fertilizer^,
contain only one of the nutrients. Examples arje
concentrated super phosphate, 0-46-0, and
ammonium nitrate, 33.5-0-0. These high-analysijs
fertilizers can be combined to provide some
advantages over the use of regular mixed fer-
tilizers because: j
• They are generally more economical than
mixed fertilizers.
• There is less material to handle.
• Extra amounts of fertilizers are avoided. j
• Seed damage due to unneeded potash (K2O) is
avoided. (This damage can occur with mixed
fertilizers such as 10-10-10.) I
In addition to commercial synthetic fertil-
izers, the organic materials listed in the follow(-
ing table have some fertilizing value and are
available in some areas:5 .
Organic
fertilizer
Cattle manure
Poultry manure .......
i
Pounds per ton |
N
10
20
P>05
5
16
K2G)
— o-oo —
r—
In some areas, sewage sludge and fly ash
::• have been used for fertilizing spoil; howeverl
technical assistance should be obtained before
using the material. The U.S. Soil Conservation
, Service (SCS) is often a good source of informal
tion for local conditions.
" Fertilizers should be applied at the time of
•""'seeding, when conditions will be favorable for
•';/germination. When seed is planted in sandy soil
'(r in late fall and remains dormant,.during the
1 winter, fertilizer application should be post-1
boned until early spring when the seed begins to
.-;-. germinate. Otherwise, fertilizers can leach out)
,\.of the soil during the winter and make refertil-*
,sization necessary. On the other hand, heavy,
/•clay soils that are wet in, the spring can be fer-j
, .tilized in the late fall even though the seed will,
•"remain dormant until spring. Clay soil will hold;
: 'the fertilizer and -prevent it from leaching, espe-j
ucially if winter temperatures are low. Mainte-j
nance applications of fertilizers may be required
in the third year or later on soil-testing recom-
mendations. Methods of applying fertilizers
include hand, hydroseeder, truck, and pull-type
spreaders.
Planting. Methods of planting vegetation at
surface mining sites vary depending on topog-
raphy, type of vegetation, stoniness of soil sur-
face, and equipment availability. Currently used
methods of establishing vegetation and their
specific suitability are:
• Hydroseeders are very useful for applying
seed, fertilizer, and mulch to steep, outslopes
and other areas where equipment accessi-
bility is limited (fig. IV-30).
• Aircraft are especially useful for broadcast
seeding on large areas, inaccessible areas
such as orphan mined lands, and during thaw-
ing and freezing periods.
• Cyclone seeders are well suited for broadcast-
ing seed on benches and level areas. Germina-
tion can be increased by limiting equipment
travel over seeded areas.
• Grass or grain drills are limited to rolling or
level terrain that is relatively free of stones.
The Rangeland drill is sturdier than conven-
tional drills and provides better and longer
performance on strip mine spoil.
• Rear-mounted blowers can be attached to
lime trucks to spread both seed and fertilizer
on steep outslopes and other inaccessible
areas.'
• Hand planting generally is used when trees
and shrubs are planted. The method is time
consuming and therefore costly.
Mulching. Mulching is required to protect
the newly seeded area from, soil erosion during
and immediately following the germination.
period. In addition, mulching provides a better
environment for germination and plant develop-
ment by conserving soil moisture, moderating
soil temperature; and, in the case of organic
mulches, providing nutrients to the soil.
Recommended practices to be considered in
the mulching of seedbeds are:
• Mulching material should be applied at the
recommended rates (sec. II, vol. II). The ma-
terial should be spread as evenly as possible
;•''" over the entire site. A comparison of straw
mulching rates and Surface coverage is given
in figure IV-31.
• Organic mulches, such as straw, hay, wood-
chips, and wood fiber, should be given prefer-
erice over inorganic mulches, since they pro-
vide needed micro-organisms, seeds, organic
: matter,"ahd'nutrients to the soil:
*J?» {-.•-:«--'ii;;.-"•".) ...'-i'>,x:»'!-- ',if , i. •;> f>•>!' ••;!.<:-
55
-------
'.:,: v t, •>.ll:: *".<'.") v'K'i I. V* '*W !*i|S l:; ^ - *' ^^-ifel J. ';^ .>v'. -.
•«s,u» ,-..»'•,.
•«a»pi9!W( rf-1 F jf*3
,>«!»••.';,:!»i* IS -s i^ f';Wl-
C's-jwr^a.j
Figure IV-30. Hydroseeding a graded and properly roughened mined area.
• Straw and hay mulches should be tacked to
prevent their removal by wind. Crimping is
the preferred method of securing the mulch
material. Asphalt and emulsified chemical
tack materials are also suited for securing
straw and hay mulch.
• Highly acidic spoil areas should be given a
heavier mulch application. Fiber glass, stone,
and other nonbiodegradable mulches will
provide long-term stabilization of these prob-
lem areas,
Information Sources
In addition to assistance from State reclama-
tion departments, various forms of assistance
are available to coal mine operators and their
representatives from local, State, and Federal
agencies.
County agricultural extension agents can be
contacted for information concerning soil sam-
pling, soil testing, revegetation, and other
matters related to agriculture. Local agents
may be contacted through the offices of State
extension service directors listed in section IV,
volume II.
The SCS alsp has regional and county offices
that can provide valuable assistance in planning
revegetation and other erosion and sediment
control efforts. Local SCS representatives may
be contacted through the State conservation-
ists' offices listed in section IV, volume II.
MAINTENANCE
Maintenance of erosion control practices is
an extremely important requirement in achiev-
ing effective control. Roadways and water-
handling structures require considerable main-
tenance attention during mining. Also, attention
must be given to revegetated areas in order to
insure that long-term soil stabilization is
achieved.
Runoff Control Practices
All water-handling structures must be in-
spected after every major storm to be sure that
no breaches have occurred. Sediment buildup in
diversion structures, such as dikes and ditches,
must also be checked. Outlet disposal areas
require frequent inspection to insure that no
erosion is occurring. Erosion damages require
prompt repair to prevent further soil loss and to
protect other areas of the site. Measures should
also be taken to insure that similar damage
does not occur in the future.
Sediment and other soil debris removed from
ditches and other water-handling structures
should be disposed of in the mine in a manner
56
-------
that will prevent the sediment from being car-
ried back into the waterways at the mine.
Vegetative Stabilization Practices
When revegetating with grasses and legumes,
top dressing with nitrogen, phosphorus, and
potassium fertilizers is required on a periodic
basis to keep vegetation healthy and provide
long-term erosion control. Too often a stand of
vegetation is allowed to deteriorate and become
ineffective because it is nutritionally starved.
Fertilizer will help keep a dense stand and pro-
vide for the growth of desirable plants. Soil
samples should be taken from reclaimed areas
and additional lime and fertilizer added as
needed.
Areas where failures have been experienced
in the establishment of vegetative protection
' av'^. .•&*£'*t&*&&t
iM^fe^Ssrll F - .5
•-fe^SssSsl&sfc^*' iisss
* 'W {& -f we• ^*yA * # ~^5 i.-"*"-X»«t * * -s' i^** t^
•
-------
must be promptly treated. If the failure is due to
rilling or gully formation, temporary structural
practices, such as flexible downdrains and sec-
tion slope drains (sec. I, vol. II), can be utilized
while arrangements for permanent control are
made. The reestablishment of permanent vege-
tative cover should be the ultimate goal. How-
ever, changed site conditions may require the
installation of some sort of permanent struc-
tural control, such as level spreaders or diver-
sion (sec. I, vol. II). Any remedial treatment
should be initiated as soon as possible in an
effort to keep the area requiring maintenance
work to a minimum. Timely maintenance will
also reduce costs in the long run.
IMonvegetative Stabilization Practices
Roadbeds should be kept in good repair to
prevent rutting and subsequent subbase satura-
tion and erosion. The roadway needs to be
graded periodically to maintain surface drainage
and keep the surfacing material evenly distrib-
uted over the roadbed. The roadbed is usually
maintained by grading smoothly with a blade.
Shaping should be done in the spring after the
road has lost its heavy moisture, but before it
becomes hard and dry. Routine smoothing dur-
ing the summer should be done after a rain has
moistened the road but not made it slippery.
In grading the road, considerable care must be
taken to prevent soil from being pushed into the
ditch, and to prevent damage to vegetation on
the safety berm.
During dry periods, periodic watering of the
roadway may be required to prevent the dust
from damaging nearby vegetation and entering
the ditch. Once in the ditch, the dust can be
easily transported to lower lying natural water-
ways.
Channel stabilization structures, such as
revetments, and check dams found in ditches,
diversions, and streams must also be frequently
inspected for damage. Repairs must be prompt
to prevent further costly damage, and measures
should be taken to prevent a reoccurrence of the
problem.
REFERENCES
1H. D. Buckman and N. C. Brady, The Nature
and Properties of Soil, 7th ed., New York, Mac-
millan Company, 1972.
2U.S. Department of Agriculture, Soil Survey
Staff, Soil Survey Manual, USDA Handbook
No. 18, Aug. 1951.
3W. H. Wischmeier and J. U. Mannering,
"Relation of Soil Properties to Its Erodibility,"
Soil Science Society of America, Proceedings,
vol. 33, 1969.
^Guidelines for Reclamation and Revegeta-
tion, Surface-Mined Coal Areas 'in Southwest
Virginia, Virginia Polytechnic Institute and
State University, Extension Division, Feb. 1973.
5J. A. Silphen, Bulletin 262, Ohio State Uni-
versity.
,58
-------
Section V
SEGMENT CONTROL
Many coal-producing States prohibit the|
discharge of'high concentrations of sediment
into their streams. Surface coal mining involved
massive earth-moving operations that subject,
large areas of unstabilized soil to accelerated
erosion. Guidelines to reduce erosion have been
presented in the preceding section. To supple-j
ment these erosion control practices, and to
provide a secondary line of defense against any!
possible off site sediment pollution, a numbeij
of sediment control practices can be used. The
objective of these practices is to filter, or settle
out, any waterborne sediment sufficiently to
meet appropriate State or Federal effluent
limitations. At the same time these structure^
delay and reduce peak flows in the streams,!
thereby reducing the potential for stream ero-j
sion.
I
SEDIMENT TRANSPORT AND i
DEPOSITION |
I
Sediment is a product of erosion. The com-|
bined processes of soil detachment, dispersion,!
transportation, and, finally, deposition are'
referred to as sedimentation. The first line of
defense against sedimentation is an effectively:
designed erosion control program. However, it
must be stressed that even with the use of the,
most effective erosion control techniques, soil
loss cannot be totally eliminated. The need foij
containment of sediment, therefore, is equally
important. This section addresses those conj
tainment measures. |
Surface runoff is the prime mover of detached
soil particles. The sediment load transported by
the runoff consists of wash load, suspended
sediment load, and bed load. The wash load
consists of very fine, or colloidal (silt- and clay]
sized) particles, which settle very slowly even
in still water. The suspended sediment is com]
posed of inorganic soil particles (fine sand, siltj
and clay) and organic particles carried anc|
supported by the water itself Bed load sedii
ment refers to the coarser particles of soil, which
move by rolling, sliding, or bouncing along the
streambed. The capacity of the channel to trans-
port material at any location decreases as the
amount of sediment being carried increases,
regardless of the type of transport taking place.
FACTORS INFLUENCING
SEDIMENTATION
Sediment transportation and deposition is
influenced by:
* The flow characteristics of the water
• The nature of the particles transported
Flow characteristics are determined by the
velocity and turbulence of the moving water.
As velocity and turbulence increase, the water
is able to transport more sediment. Conversely,
as velocity and turbulence decrease, the water
has less potential for transporting sediment,
and deposition of soil particles occurs.
The nature of the particles being transported
refers to their size, shape, and density. Smaller
and lighter particles, such as fine sand, silt, and
clay, are more easily transported by water than
coarser particles; the coarser and heavier par-
ticles are more easily deposited.
SEDIMENT CONTAINMENT STRATEC5Y
In developing a sediment containment strat-
egy for a particular mine site, or a portion of
that site, there are a few basic concepts that
must be considered, if the greatest possible
degree of control is to be achieved. First among
these is the concept of "at-source" control. This
means that every effort should be made to
control the sediment at, or as near to, its source
as possible (fig. V-l). It is too often the practice
to attempt to control the sediment from the
entire area being disturbed by building one or
more large sediment basins offsite and in the
major drainageways (fig. V-2). This approach
requires that a much larger drainage area be
controlled, as well as the construction, cleaning,
and possibly, the postmining removal of larger
structures. From a sediment control standpoint,
59
-------
.
,. ,* jjp^nni n-jn,lt.,jrpiliti,|.ul.*r.ai--,i,,r;-;||l;ll.,"1 3,,,, ,IF f '» . '
, '.- Igr- , • ,;•• •A-^L'MjSsSS^f ^
Figure V-1. Trapping sediment on the bench near its source.
j»p»ii ii j "'i
iidlBlitf""!' „ ; :ii', L3" ••
Figure V-2. Perimeter sediment basin at a surface coal mine.
60
-------
and for other environmental reasons, it is morei
desirable to segregate the sediment-laden wa-j
ters from the rest of the surface flow. j
Another important concept is identification!
and control of all major sources of sediment. |
The major sources of sediment from surface)
mine operations are generally access roads andj
spoil areas. As shown in table II-2, for an equal|
area of disturbance, sediment yield from haul
roads can be twice the yield from spoil banks,
and 30 times as high as the yield from the entire |
mine—a fact that is often ignored. A single
basin is built in the stream valley to control the
entire mine site. Portions of the haul road, how- i
ever, often drain into different watersheds ;j
consequently, some sediment goes completely j
uncontrolled. The sediment control plan should |
clearly identify all major sediment source areas>
at the mine, and show how the surface drainage j
from each area is to be controlled. j
A third concept, upon which all sediment i
control practices are based, is runoff control.)
There can be very little control over the nature \
of the particles transported. It is usually j
feasible, however, to control the velocity of the!
water and the associated turbulence. A decrease
in velocity and turbulence will reduce the ability
of the water to transport sediment, and the
sediment will settle out.
Reduction in slope steepness and/or length,
roughening of slopes, spreading rather than
concentrating flow, dissipating flow energy,
and detaining flow are all means of slowing the
flow of surface runoff and, thus, reducing its
ability to transport detached soil particles (fig.
V-3). Slowing also reduces the ability of the run-
off to detach other soil particles.
TYPES OF CONTROL
Vegetative Buffers
Both natural and installed vegetative buffers
are used to detain, absorb, and filter overland
runoff, particularly sheet flow, and thus trap
sediment.
Natural Vegetative Buffers. This practice
involves the preservation and protection of a
strip of natural vegetation downslope of the
Figure V-3. Slope roughening and flattening to trap sediment near its source.
61
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area disturbed by mining (fig. V-4). Where the
ground slope is not too steep, a band of thick
vegetation, whether grass or woody plants with
accompanying ground litter, is an effective and
economic means of trapping sediment washed
from perimeter spoil slopes or haul road out-
slopes.
Installed Vegetative Buffers. Where the
existing vegetation will not form a satisfactory
buffer, or where an open drainageway is con-
structed, timely establishment of a vegetative
buffer will help trap sediments (fig. V-5). Staging
grading operations to provide a vegetated area
between critical features, such as a drainage-
way, and higher elevated areas being reclaimed
is the recommended procedure for installing a
vegetative buffer. The surface of the buffer area
should be roughened and planted to a quick-
growing, robust grass. Flattening the slope in
the buffer area will also help slow the runoff and
trap sediment.
Sediment Traps
Sediment traps are small, temporary struc-
tures used at various points within, and at the
• "'; r:< :»^.3fe»4!fii«£^ •'; sfr.r;.
Figure V-4. Natural vegetative buffer below a haul road.
Figure V-5. Vegetative buffer strip below a spoil bank trapping sediment.
62
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wSf^SA-^^l^1*^*^©^ «S"tttii.''':'-„ !>.y*/'-i5-ii%-jr-..*•.'••-• • • -•;#r:f.J>ft^|!,fa^«Afc.
;'ii-S.»w»mi-iKif -k.?, ^fe&lsasu-iii. -i:*-kJLsfc..>-ifcSt,**M*im^tfc&#«* «.
Figure V-7. Stone ch!eck dam trapping sediment.
periphery of, disturbed areas to detain runoffj
for a short period of time and trap heavier sedi-1
ment particles (fig. V-6). Various types of sedi-
ment traps used include sandbags and straw
bales, stone check dams, log-and-pole struc-j
tures, excavated ditches, and small, pits (fig.
V-7). In fact, any sufficiently large depression
in the surface will act as a trap. Depressions or|
undulations, particularly in the pit area, are)
recommended since they will detain the runoff
and help to settle out some of the suspended
sediment. See section I, volume II, for design
and construction considerations.
Sandbags and Straw Bales. These devices
are very easy and economical to construct. They
need a limited amount of equipment for their
construction, and therefore create less disturb-
ance of the area in which they are constructed.
63
-------
Sandbag-barrier sediment traps are con-
structed of bags filled with sand or crushed rock
that are stacked in an interlocking manner (fig.
V-8). Straw bale sediment traps are constructed
of bales of hay or straw stacked as shown in
figure V-9. Tying the bales with wire and stak-
ing them to the ground provides additional
stability. Undercutting is the major cause of
failure of these barriers. This can be prevented
by setting the sandbags or straw bales 4 to 6
inches in a trench and compacting excavated
soil along the upstream side.
Sandbag barrier
Undercutting occurs
when sandbags
lie on surface
of channel
Compacted soil
prevents piping
underneath
sandbags
Figure V-8. Sandbag barrier.
Figure V-9. Straw bale barrier.
64
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Log-and-Pole Structures. A drawing of a
log-and-pole structure is shown in figure V-10.
These structures are built across waterways. The
structure is built from the timber that is gener-
ally available at the site. Log-and-pole struc-
tures serve two purposes. First, they retard the
flow of runoff and catch some of the sediment
load. Second, they delay and reduce the peak
flow in the stream, thereby reducing the poten-
tial for stream erosion. The effectiveness of
these structures can be increased further by
building several structures at regular intervals
along the drainageway.
Sediment Basins
State-of-the-Art. Sediment basins are the
most effective structures for trapping sediment.
They are generally used in large earth-moving
operations where heavy concentrations of both
runoff and sediment are anticipated (figs. V-ll
and V-12). The conventional method of control-
ling sediment that reaches the periphery of the
mining operations is through the construction
of a sediment retention basin at a point that
intercepts the surface runoff before it leaves the
mining site. There are two types of sediment
ponds: the dry basin and the wet basin. The dry
basin is generally used to trap sediment in an
offstream location, and, therefore, is preferable.
The wet basin is used when it becomes necessary
to dam permanent streams in order to trap sedi-
ment.
Design standards and construction criteria
for sediment basins vary from State to State,
although most State standards are adapted
from those developed by the Soil Conservation
Service'(SCS). To this date, only two States in
the region covered in this manual have actually
modified the basin design to fit the surface min-
ing industry.1-2 Under the SCS approach, sedi-
ment basins are usually not designed to achieve
any set effluent water, quality criterion or to
remove any given percentage of trie sediment in
the inflow. Rather, the size of the basin is usu-
ally determined by utilizing a rule of thumb on
the volume of the basin required based on the
area of land disturbed. For example, the State
of West Virginia, based oh studies by the U.S.
Forest Service and SCS, requires that the sedi-
ment basin pool have a minimum capacity to
store 381 cubic meters per hectare (0.125 acre-
feet per acre) of disturbed area in the drainage
area.1
The SCS sediment basin design approach
does not provide the designer with enough
information to insure that State, and Federal
water quality criteria are met. A recent study of
the effectiveness of sedimentation basins de-
signed under this method revealed that during
Figure V-10. Log-and-pole structure.
65
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^l: %
^^^^^g^i^5^(P^
Figure V-11. Sediment basin.
-'*-- -• *•-- •
Si*/
Figure V-12. Sediment basin functioning during a storm.
66
-------
a storm the majority of these basins do not meet
the proposed Federal criteria (table V-l ).3 Clearly
a more rigorous and complete design procedure
is needed. An alternative approach derived from
the design process for settling tanks used in
wastewater treatment facilities is provided.
Design consideration. Designing a sediment
pond based on the removal of a certain size
particle or percentage of suspended sediment
requires more design data than the SCS ap-
proach. Many of the variables that need to be
quantified for input to the design are not nor-
mally measured during the preliminary design
or site investigations. However, these data can
be obtained easily during the site exploration
without much additional effort. The following
factors must be known or assumed before an
analysis can be made:4
• Design outflow rate (design stormflow)
• Anticipated grain-size distribution of the in-
coming sediment
• Expected suspended solids concentration in
the inflow
• Specific gravity of the incoming solids
• Anticipated pond water temperature
Solids removal. The sediment basin can be
designed to achieve a certain percentage re-
moval of the suspended material or to settle
out a minimum-size particle. These two param-
eters are plotted against each other on a grain-
size distribution curve. Or, the basin can be
sized to meet a given effluent solids concentra-
tion. These parameters are related by the fol-
lowing formula:
R (% solids removed) = < 1 -
106
>100
-1
where Cj = solids concentration of influent, mg/1
c2 = solids concentration of effluent, mg/1
This formula, which was originally derived
from a simple mass balance for a conventional
dredged-material-containment basin, is useful in
evaluating the efficiency of the sediment basin.4
Table V-1 .-Results of pond sampling during rainfall conditions
Pond
number
1 ....
2 .....
3
4
5
6
7
8
9
Flow
average/range
(m3/s)
0.021
.028
.149
.133
.060
.042
.012-.093
.013
.056-.110
Computed
detention
time
(h)
31.9
7.8
4.4
5.2
325.0
20.8-2.7
184.4
5.7
Sampling
period
(h)
2.0
2.0
4.0
4.0
5.0
26.0
16.0
5.5
7.0
Number'
of
samples
8
:. s
8
16
9
8
9
8
10
Average suspended
solids concentration
(mg/l)
Influent
474
239
21,970
9,643
668
868
765
363
412
Effluent
196
17
11,539
6,198
275
35
66
28
193
Actual,
removal
efficiency
(percent)
58.8
92.8
48.0
36.4
58.8
95.9
91.3
92.3
53.1
Theoretical
removal
efficiency
'(percent)
95
88
83
84
91
99
83-67
97
99
Source: D. V. Kathuria, M. A. Nawrocki, and B. C. Becker, Effectiveness of Surface Mine Sedimentation Ponds prepared by
Hutman Associates, Columbia, Md., for the U.S. Environmental Protection Agency, Office of Research and Development Cincinnati
Ohio, Contract No. 68-03-2139. ! '
I
67
-------
The removal of solids by settling is basically
a function of the overflow rate and the surface
area of the basin. Depth of the basin and deten-
tion time are not primary design parameters,
but they can affect the design and thus are sec-
ondary considerations. An initial approximation
of the solids removal capabilities of a conven-
tional basin can be made by assuming theo-
retically ideal settling conditions. For the
theoretically ideal case, the size of the particles
that will be retained will be determined by the
overflow velocity and the critical settling veloc-
ity of the particles. The basic ideal relationship
can be expressed in general terms below:4
Required settling area =
Overflow rate
Critical settling
velocity of the
smallest particle
to be retained
In the design of sediment ponds to settle a cer-
tain size particle, the ratio of the pond outflow
to the surface area of the pond, Qo/A, is termed
the overflow velocity Vo. Thus:
Vo = Qo/A
Based on the above relationship, it can be shown
that if the critical settling velocity of any size
particle is greater than the overflow velocity,
that particle and all larger than it will settle
out. Increasing the area of the pond, therefore,
would decrease the overflow velocity. This
means that a smaller particle size could be
settled out.
Factors affecting ideal settling. In any sedi-
ment pond, it is unlikely that purely ideal
settling conditions will be met. Factors that dis-
turb the smooth settling and thus alter the pond
area required as calculated using ideal settling
theory include:
Short circuiting
Bottom scour
Turbulence
Nonuniform deposition of materials
Entrance and exit effects
Shape of the suspended particles
Specific gravity and velocity of the suspend-
ing liquid
In most cases, the effects of the above factors
would be to increase the pond surface area re-
quired over that calculated by ideal settling
theory. In usual design practice the surface area
calculated by ideal settling theory is multiplied
by a factor of 1.2 to account for nonideal settling
factors.4
A complete description of the design proce-
dure and a detailed design example are provided
in section I of volume II in the design and con-
struction specifications for sediment basins.
Methods for improving pond efficiency. A
number of innovative techniques have recently
been developed that can help increase the pond
efficiency.6
• Baffles can be located within the pond to
increase the detention time and also, if prop-
erly placed, provide for utilization of the full
area of the pond.
• Partitioning the pond into a number of cham-
bers and then introducing and overflowing
water from particular chambers along the
entire width of the sediment pond can also
improve its performance.
• Dye tests on experimental sediment ponds
have shown that maximum efficiency can be
expected from a sediment pond when the
length-to-width ratio is maintained at about
5tol.
• Construction of an energy dissipator at the
pond entrance can produce a reduction in the
inflow velocity and consequent deposition
of sediment before it reaches the pond.
• Modifying the inflow to the sediment basin
so that the flow enters along as much of the
entire width of the basin as possible is an-
other flow modification technique that has
proved effective.
• Wrapping a plastic filter cloth around a
standard perforated riser can increase the
retention of fine-grained material. However,
the filter cloth will eventually plug with the
fine-grained sediment.
• A siphon arrangement in a nonperforated
riser pipe is also effective in improving the
sediment pond efficiency.
0 Use of a very wide overflow wier instead of a
standard riser pipe reduces the outflow veloc-
ity and thus increases the removal efficiency
of the pond.
• Two or more ponds used in series instead of
one larger basin covering the same area have
been shown to increase the removal efficiency.
The multiple-basin concept equates to the use
of a compartmentalized, larger sediment
basin. Thus, higher removal efficiencies can
be expected from both multiple sediment
basins and a compartmentalized, larger
basin.
Chemical Treatment. Generally, the surface
runoff from the mining area is pumped, or
diverted, into settling basins where natural
gravitational settling is used to remove the
suspended solids. The removal efficiency of
68
-------
suspended solids depends on the surface area
of the basin and on the detention time. If the
inflow of the settling basin has a high percent-
age of fine-grained (silt and clay) sediments,
there may not be adequate land area available
to construct a settling basin of the size required
to obtain the desired water quality. Since fine
silts and clays carry a negative electric charge,
they repel each other, and stay in suspension
for long periods of time, thereby producing a
turbid effluent. In these cases, chemical treat-
ment is necessary to affect the negatively
charged colloidal particles, causing them to be-
come attracted to each other and form larger
masses of particles that settle out.
Types of Coagulants. The addition of coag-
ulants causes fine-grained particles to agglome-
rate, and thereby exhibit the settling charac-
teristics of coarser sized particles. The chemical
coagulants normally used are classified into the
following three types:
• Metal salts
— aluminum sulf ate
— ferrous sulfate
— ferric chloride
• Metal hydroxides
— aluminum hydroxide
— calcium hydroxide
• Synthetic polymers or polyectrolytes
— anionic
— cationic
— nonionic
Selection of the type of coagulant and re-
'quired dosage is an important factor in the
design of a chemical treatment system, and
depends upon the characteristics of the specific
material to be removed. There is no accurate
theoretical method or rule for selection of a
coagulant and its dosage. However, a rough
estimate of the amount of coagulant can be
made by a standard jar test, or by measurement
of the suspended particles. The optimum dosage
for best results will be adjusted in the field.
MAINTENANCE
All sediment containment measures require
adequate and timely maintenance throughout
their design lifespan to perform efficiently
(fig. V-13). If they are built in an area where
accessibility is poor, they are often ignored and
forgotten. They should be located in an area
where they are readily seen, and adequate acces-
sibility should be provided for the maintenance
equipment to perform emergency and routine
n VJ^-^ ~»i>» n, . .•* f
R^?ip:
Figure V-13. Basin inspection.
-------
•" - - "*•'. • ** „,. j-T" v-C* ''*y'*:ji*;y j
•«*J^
- . •r'^^.'.Cf"^^'*'-'-'^-^^^:y?lf^S^>tv^!sli'^fif-' ' !%«Si?fr*v|L- •*£.;-'
"*£•• .'.:.': ' ' T* .v'^'^^vV4 ^','- •
•^'•'s-.tytftfy'-'.* .-;.'..•>(.;•"
Figure V-14. Well-built and -maintained basin.
repairs. Responsibility for maintenance must
be formally assigned to an individual who is
knowledgeable of maintenance requirements
and also has access to equipment and materials
required for this purpose (fig. V-14).
All sediment containment structures require
inspection after high-intensity or major rain-
storms. Corrective decisions made onsite at
this time can reduce sediment damages and
operating costs in the long run. Most of the
at-source sediment control measures cannot sur-
vive if they are subjected to foot or vehicle
traffic. In areas where the measures are in-
stalled, the prohibition of traffic must be main-
tained.
Sediment Removal
The most important maintenance problem
associated with sediment containment basins is
the removal of accumulated sediment. Re-
search has shown that the highest sediment
yields are usually observed during the first
6-month period after mining. Filling of sedi-
ments in the basin reduces its capacity to retain
runoff long enough for sediment to be deposited
before it is carried downstream. Many States
have established criteria for sediment removal
from the basin. A rule of thumb that can be
used is to clean out a basin when it has reached
50 percent of its sediment storage capacity, or
6 months after the mining operation was started,
whichever comes first. In the design for storage
capacity of a sediment basin, provisions should
be made to accumulate enough sediment to per-
mit the pond to function for a reasonable period
' between cleanings.
For small sediment traps used near the min-
ing activity, cleaning is generally best accom-
plished by dragline and truck transport, since
this equipment is readily available (fig. V-15).
Removed material can be stockpiled directly
on the banks, and allowed to dewater before
being hauled away, or it can be buried in the
mine pit.
For large containment basins that cannot
be cleaned by draglines operating from the
banks, the cleaning becomes more difficult.
In such cases, the services of professionals
experienced in the handling and disposition of
sediment should be retained.
Sediment Disposal
Sediment disposal is an integral part of the
sediment removal program from a containment
basin. Indiscriminate piling or dumping of
removed material is more likely to allow sedi-
ment to reenter the surface drainage system
dur-ing successive storms, and thus become a
pollutant again. The'sediment removal opera-
tion must also consider the stable disposition of
the material removed from the basin. Where
disposal of a small quantity of sediment is
70
-------
involved, it can be disposed of behind a protec-
tive berin or grass filter strip, or buried in the
mine pit. For larger quantities of sediment,
special provisions should be made either to bury
it in an area designated for this purpose, or to
stockpile, dewater, and vegetate it properly.
POSTMIIMING CONSIDERATIONS
Sediment containment structures should be
designed to be temporary structures for trap-
ping sediments generated from exposed areas
during surface mining operations. Once the min-
ing is completed, and all disturbed areas are
well stabilized, all sediment control structures,
as well as the accumulated sediment, should
be abandoned and/or disposed of in a proper
manner. If proper attention or consideration
is not given to postmining aspects in this area,
control structures as well as the accumulated
sediment may in time be carried into the streams
and natural waterways during major storms.
By thus becoming part of the pollution problem,
the very purpose of their use in the first place
would be defeated. It is, therefore, extremely
important that the disposal and dismantling
of all temporary control devices be performed
before all mining equipment is demobilized from
the mining area.
Disposal of Accumulated Sediments
Proper handling, disposal, or abandoning
procedures for trapped sediment should be
contained in the original plans and specifica-
tions for surface mine development. In the event
that the accumulated sediment is to be left in
place, it should be covered, topsoiled, and vege-
tated, or stabilized by mechanical means, to
prevent it from sliding or eroding back into the
stream. If the accumulated sediment is to be
disposed of in a predetermined area within the
mine property, it should be spread in layers,
dewatered, covered with earth, and stabilized
by vegetation or mechanical means (fig. V-16).
The depth of the layer will depend on the grain
size of the material being handled.
Dismantling of Earth Embankments
If the earth embankment is built across a
natural drainageway, the embankment and all
Figure V-15. Backhoe loading sediment irjto a truck for transport to a disposal area
71
-------
accumulated sediment should be removed and
disposed of in a predetermined area within the
mine property. The natural stream should be
returned to its original profile and cross section.
The side slopes and bottom of the stream should:
be riprapped to prevent future erosion.
If the embankment is built adjacent to the
natural waterway, it may be left in place by di-.
verting the entrance channel to the natural!
waterways, thus preventing any future surface
runoff from entering the impoundment.
Excavated Ponds
Offchannel dugout ponds, which are usually
built by excavating a pit in the ground, should
be backfilled, preferably with the material
constituting the embankment around them. The
backfilled material should .be properly com-
pacted. All areas disturbed as a result of this
operation should be stabilized with vegetation.
If it is anticipated that the pond could serve
some useful purpose, it may be left in place.
However, precautions must be taken that no
surface runoff enters the pond and that the
outflow channel from the pond is protected
against erosion.
The ponds that are built by excavating the
streambed to store sediment should be back-
filled so that the stream is brought back to its
original profile and cross section. The side slopes
and bottom of the channel should be stabilized
by mechanical and/or vegetative means.
REFERENCES
West Virginia Drainage Handbook for
Surface Mining, prepared by Division of Plan-
ning and Development and Division of Reclama-
tion, Department of Natural Resources, in
cooperation with Soil Conservation Service,
U.S. Department of Agriculture.
'Engineer's Handbook on Strip Mining in
Eastern Kentucky, Department for Natural
Resources and Environmental Protection, Com-
monwealth of Kentucky.
"C. W. Mallory and M. A. Nawrocki, Contain-
ment Area Facility Concepts for Dredged Mate-
rial Separation, Drying, and RehanHling,
prepared by Hittman Associates, Columbia,
Md., for the Environmental Effects Laboratory,
U.S. Army Engineer Waterways Experiment
Station, Contract No. DACW 39-73-0-0136,
Oct. 1974.
5M. A. Nawrocki and J. M. Pietrzak, "Meth-
ods to Control Fine-Grained Sediments Result-
ing From Construction Activity," Draft Report
HIT-648, prepared under EPA Contract' No.
68-01-3260, June 1976.
3D. V. Kathuria, M. A. Nawrocki, and B. C.
Becker, Effectiveness of Surface Mine Sedi-
mentation Ponds, prepared by Hittman. Asso-
ciates, Columbia, Md., for the U.S. Environ-
mental Protection Agency, Office of Research
and Development, Cincinnati, Ohio, Contract
No. 68-03-2139. , .,'"'.
Figure V-16. Diked sediment disposal area on relatively flat ground.
72
-------
Section VI
CONTROL PLAN
The erosion and sediment control plan is the (
blueprint that will enable the operator to mine
the coal without choking adjacent streams with
.sediment. The control plan is an important
part of the overall mining and reclamation
plan, and should consist of a comprehensive,
explicit set of instructions for controlling ero- j
sion and sediment during and after active
.mining. This section discusses the legal and
technical considerations, the makeup of the
control plan, the information required to prepare
the plan, as well as the procedure for preparing
the plan.
Preparation of an erosion and sediment con- j
trol plan consists of five basic steps: <
• Identification of legal and technical require-
ments
• Collection and evaluation of site information |
• Development of a control strategy |
• An interdisciplinary field review of the feasi-
bility of the preliminary sketch plan
• Revision and finalization of the control plan
LEGAL AND TECHNICAL
REQUIREMENTS
Prior to undertaking the preparation of an
erosion and sediment control plan, the surface
mine operator, or his engineer, must become
knowledgeable of both the legal and technical
requirements of the State in which the operation
will be located. Legal considerations include
laws, regulations, and design criteria at both
the State and Federal levels. These legal require-
ments vary considerably from State to State.
A summary of reclamation requirements, both
legal and technical, in the States covered by the
manual is provided in section IV, volume II,
which also includes a listing of the designated
reclamation agency (agencies) in each State
that can provide the operator with the necessary
information.
The reclamation requirements usually ad-
dressed in the State regulations include mine
drainage restrictions, highwall restrictions,
topsoiling requirements, revegetation stand-
ards, and grading requirements. Some States
also stipulate acceptable effluent standards for
surface coal mining operations. Table .VI-1
compares the Federal effluent standards for the
surface coal mining industry with the standards
set by three Appalachian States. It has not yet
been definitively established that sedimentation
basins can reliably meet these effluent stand-
ards, particularly in .areas that have soils with
high percentages of silt and clays. In such
cases chemical treatment becomes necessary
and cost of control increases considerably.
The erosion and sediment control plan is itself
only one part of the overall mining and reclama-
tion plan. The overall plan is made up of a com-
bination of narrative description, construction
plans and drawings, details, and specifications.
Table VI-2 provides a complete checklist of the
recommended erosion and sediment control plan
components. Depending on individual State
preferences, this information may be mixed into
the reclamation portion of the overall plan, or
totally or partially segregated under the heading
of "erosion and sediment control."
EVALUATION OF SITE INFORMATION
Conducting a thorough site evaluation prior
to developing a mining plan is an important
prerequisite to achieving cost-effective sediment
control. In addition to investigating the nature
and extent of the coal resources, the site evalua-
tion must involve a complete investigation of
features directly and indirectly influencing soil
loss and the potential for offsite damage. Influ-
ential features include topography, geology,
soil, climate, hydrology, vegetation, and land
use.
The site evaluation should be performed by
individuals, or a team of individuals, experi-
enced in the selection, design, and layout of both
surface mining operations, and erosion and
sediment control. The evaluation team should be
knowledgeable of earth and vegetative sciences
and capable of identifying the critical physical
features affecting erosion and sediment control.
-------
The evaluation usually comprises a combination
of published information surveys, surface and
subsurface investigations, and laboratory analy-
ses.
Sections IV and V of this manual contain
information on the relationship of various site
features to sedimentation processes and the
use of control practices.
Published Information
Topographic maps, soil maps and surveys,
vegetative maps, geologic maps and reports,
and aerial photographs can be obtained, often
free of charge, from various State and Federal
agencies and institutions. Table VI-3 shows
sources of such published information. To the
experienced and trained individual these docu-
ments provide a valuable source of information
on physical features that relate to erosion and
sediment control.
Local land use and zoning maps should also
be consulted. These maps will provide informa-
tion on current and projected land uses in the
vicinity of the mine site, and will help in deter-
mining postmining land uses.
Surface Investigation
The primary purpose of the surface -investi-
gation is to identify, prior to preparation of the
overall mining and reclamation plan, surface
features having a major influence on soil loss
and potential offsite damage from sediment.
This work involves both a survey of available
souces of published and, when available, unpub-
lished information, and a thorough field investi-
gation of the site and surrounding areas. The
results of this investigation, along with the
findings from the subsurface investigation, are
needed to identify mining practices that will
minimize sediment damages and formulate a
cost-effective erosion and sediment control plan.
Surface features requiring investigation
include surface soils, drainageways, vegetation,
and topography.
The presence of highly erodible surface soils
is a critical physical feature. This is especially
true if these soils occur on moderate to steep
slopes. Soil credibility should be considered
when locating access roads and other offsite
facilities, and in formulating plans for clearing,
grubbing, and scalping operations. The location
and characteristics of streams and other natural
drainageways deserve very careful examination
during the surface investigation. Not only are
they the recipients of sediment from the mine
site and access roads and transporters of sedi-
ment to areas farther downstream, but also they
themselves can contribute to the sediment load
through channel erosion. Increased surface run-
Table VI-1 .—Effluent standards for the surface mining industry
State
Federal
Kentucky
Pennsylvania
West Virginia
Turbidity or
suspended solids
30-100 mg/l
150Jtua
(b)
I
100 Jtu or less0
i
PH
60-Q f)
6 0-9 0
6 0-9 0
5 5-9 0
Total iron
mg/l
4n.7 n
Alkalinity
.'|l! 'I
1 ' ' ' ' 1 ,'il ' ' "
"The discharge shall contain nosettleable matter, nor shall it contain suspended matter in excess of 150 Jackson turbidity units
(Jtu), except during a precipitation event, which the operator must show to have occurred, in which case 1,000 Jtu may not be
exceeded.
No silt, coal mine solids, rock debris, dirt, and clay shall pe washed, conveyed, or otherwise deposited to the waters of the
Commonwealth. '.
"Turbidity—not more than 1,000 Jtu 4 hours following a major precipitation event and not more than 200 Jtu after 24 hours
(major precipitation event = 1/2 inch of rainfall in 30 minutes). [ '. ' "
Source: D. V. Kathuria, M. A. Nawrocki, and B. C. Becker.'Effectiveness of Surface Mine Sedimentation Ponds, prepared by
Hittman Associates, Columbia, Md., for the U.S. Environmental Protection Agency, Office of Research and Development Cincinnati
Ohio. , ' ... '
74
-------
Table VI-2.—Information checklist for an erosion and sediment control plan
Background information:
1. General:
Location of project
Extent of area to be affected
Type of mining operation
Evidence of compliance with State's legal
requirements
2. Site inventory:
• Topography
Geologic analysis
Soil analysis
Climatic analysis
, Hydrologic analysis
Vegetative analysis
Land use analysis
Schedule of activities:
Site preparation:
1. Access roads:
Plan view (location)
Typical cross section
Profiles
Maintenance requirements and schedule
2. Drainage and sediment control structures:
Plan view (location)
Typical cross sections
Details (where needed)
Design computations (where needed)
Maintenance requirements and schedule
3. Clearing and grubbing:
Plan views of limits of areas to be cleared
Description of procedure
Machinery to be used
Method of disposing of timber, brush, and
waste materials
Identification of critical areas requiring
temporary stabilization
Mining operations:
1. Scalping:
Method of scalping topsoil material
Equipment to be used
Plan view of topsoil storage areas
Temporary vegetative stabilization of
stockpile areas
Schedule of activities—continued:
Mining operations—continued:
2. Overburden handling:
Method of overburden handling
Handling of first cut
Plan view of overburden storage
areas "
Stormwater handling in overburden
storage areas
Temporary stabilisation measures
Permanent stabilization measures
Reclamation operations:
1. Handling of toxic material:
Method of handling toxic material
Equipment to be used
2. Spoil rehandling and grading:
Typical cross section of regrading
Equipment to be used
Method of spreading topsoil or upper
horizon material on the regraded
area, including approximate
thickness of the final surfacing
material
Method of drainage control for the
final regraded area
3. Revegetation:
Method to be used
Surface preparation
Type of vegetation
Fertilizer application (method and
. rate)
Seasonal revegetation schedule and
rate
Mulch application (method and rate)
Maintenance requirements and sched-
ule
4. Mine abandonment:
Method fordisposal and stabilization
of drainage structures not cov-
ered above, particularly sediment
basins
Method for stabilization and/or aban-
donment of haul road
Assignment of responsibility for any
permanent structures left behind
Maintenance program and schedule
for any permanent structures left
behind
-------
Table \f\-3.-Published information aids
Informational aid
Where obtained
Information available
Aerial photographs
to LANDSAT imagery .
Topographic maps
Soil surveys.
Vegetative maps.
Geologic maps and reports
East of the Mississippi River:
U.S. Geological Survey, Distribution
Center, 1200 South Eads St.,
Arlington, Va. 22202
West of the Mississippi River:
U.S. Geological Survey, Federal
Center Bldg. 41, Denver, Colo. 80225
Local air services
U.S. Soil Conservation Service (SCS)
U.S. Forest Service
Agricultural Stabilization and
Conservation Service
NASA
EROS Data Center, Sioux Falls, S.Dak.
Same as aerial photographs
U.S. Soil Conservation Service,
Independence Ave. between 12th and
14th Sts.,S.W., Washington, D.C.
Local Soil Conservation Service office
See section IV, volume II, for complete
list of counties with surveys.
U.S. Department of Agriculture,
Independence Ave. between 12th and
14th Sts.,S.W., Washington, D.C.
U.S. Forest Service
State forestry division
State agriculture division
Local universities
Infrared and other aerial photographs
Universities ;
U.S. Geological Survey
State geological survey
1. Drainage networks
2. Land forms
3. Extent of colluvium, alluvium,
and other
4. Vegetative patterns (infrared)
5. Fracturing and jointing patterns
6. Slope gradients
7. Location of mass movements
8. Land cover characteristics
1. Benchmarks
2. Slope gradients
3. Location of roads, buildings, and
nearest towns
4. Drainage basins
5. Relief
6. Stream systems
1. Types of soils
2. Extent of various soils
3. Engineering properties of soils
4. Land use potentials for .various
soils
5. Erodibility of soils
6. Aerial photographs ,
7. General textural characteristics
of the soils
1. Types and extent of vegetative
cover
2. Density of cover
1. Kinds of strata
2. Location of geologic hazards
a. Faults
b. High-water tables
3. Strikes and dips of various strata
4. Geologic trends in the area
5. Topographic features and their
relationship to the geology
76
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off resulting from both mining and construction
and sedimentation of the channel is a factor
contributing to channel degradation. The gradi-
ent, alignment configuration, and the nature
of the material lining the channel determine the
susceptibility of the stream to erosion and its
ability to transport sediment. Stream biology
and recreational, industrial, and municipal uses
are major considerations in determining the
level of sensitivity to sediment pollution.
Streams and other drainageways intercepted
by the mining operations and access roads will
require very special attention, both during and
following mining, if costly offsite damages are
to be avoided.
Natural ground slope and vegetative cover
will also have a major bearing on the potential
for offsite damage. Fairly flat, well-vegetated
buffer areas found below a mine site or access
road are a major deterrent to the movement of
sediment into waterways. On steeply sloping
terrain where a good buffer area is not present,
very careful consideration must be given to
handling of sediment-laden runoff. •
Water quality should also be studied during
the surface investigations. If initial investiga-
tions indicate the suspended solids concentra-
tion is high due to natural causes or other land
disturbances in upper portions of the watershed,
it would be advisable to monitor the site and,
thereby, more accurately establish the baseline
conditions.
Potential roadway alignments, head-of-
hollow fill areas, and other outslope spoil dis-
posal areas require careful examination to locate
possible landslide areas. Such areas include
slopes containing ground water seeps, unstable
soil, or bedrock material.
Subsurface Investigation
The subsurface investigation should not be
limited to the identification of those geological
features, soil, and overburden properties which
relate to mining and geotechnical engineering
and acid mine drainage. It should also be uti-
lized to determine those chemical and physical
properties of the overburden (both soil and bed-
rock) which influence credibility and capability
to sustain a long-term vegetative cover.
Erodibility factors to be examined include
texture and permeability of soil material, weath-
ering characteristics of fragmented bedrock
materials, and clay mineralogy (sec. IV). This
information will help in identifying suitable
topsoiling material, grading (slope length and
steepness) requirements, and the sophistication
of perimeter sediment control practices.
From the standpoint of revegetation, the
identification of suitable topsoiling material is
extremely important. This will require an evalu-
ation of surface soils to determine their suit-
ability for salvage and use as topsoiling mate-
rial, and a study of other overburden material,
including shales and other bedrock materials, to
determine whether or not they are more suitable
for use as topsoiling material (fig. VI-1). Impor-
tant parameters to be studied when evaluating
overburden materials for use as topsoiling
material are texture, pH, and nutrient level.
Organic content and weed seed content are also
looked at when evaluating surface soils.
Texture (i.e., size and gradation of soil par-
ticles) and organic content will determine the
ability of a soil to absorb surface water and to
retain water for use by vegetation. This latter
characteristic is referred to as moisture-holding
capacity. When evaluating textural properties
of bedrock materials, fragmentation (i.e., size
of rock particles after blasting) and weathering
characteristics must also be considered.
Problems related to pH are common and must
always be investigated. Excessively acidic soils
will require periodic applications of crushed or
pulverized limestone or dolomitic limestone in
order to maintain a good vegetative cover. If
the pH problem is not too severe, the use of
vegetation with acid-tolerant characteristics
may be in order. The major elements that affect
the nutrient level of the soil are nitrogen, potas-
sium, and phosphorus. Soils (spoils) deficient
in these nutrients will require periodic applica-
tions of fertilizers selected on the basis of soil
tests.
Clay mineralogy is also an important factor
to be examined when evaluating possible top-
soiling material. The presence of large quantities
of highly expansive or "fat" clays, such as ben-
tonite or montmorillonite, in a soil will decrease
its permeability significantly, thus reducing
infiltration and, ultimately, the ability of the
soil to support vegetation.
Overburden samples for conducting various
tests can be obtained while drilling to evaluate
the coal deposits (fig. VI-2). However, addi-
tional coring may be required to get unblended
samples of the overburden material. Surface
soil samples can be easily obtained using hand-
sampling techniques. Where deep soils exist,
test pits may be required to gather visual infor-
mation and collect good samples for testing.
Further guidance in performing subsurface
investigations, conducting various tests, and
in evaluating results can be obtained from the
Soil Conservation Service (SCS) district or State
office, and from the State geological survey.
State offices of these agencies are listed in sec-
tion IV, volume II.
-------
Figure VI-1. Gathering topsoil sample.
Climatic Data
The gathering and assessment of climatic
data are also important in the preparation of
an erosion and sediment control plan. Important
climatic factors to be investigated include rain-
fall frequency, duration, and intensity and tem-
perature, sunlight, and radiation.
The following functions require a knowledge
of climatic factors:
• Design of drainage systems for access roads:
When designing a drainage system, informa-
tion must be obtained on expected frequen-
cies, intensities, and durations of severe
storms (usually a 10- to 25-year frequency).
Culverts, ditches, and other structural con-
trol features must be sized to handle the
anticipated storm runoff.
• Location and sizing of stormwater and sedi-
ment detention facilities: Whereas the other
elements of the drainage system are designed
to handle a peak flow rate for a selected de-
sign storm, sediment basins and traps are
designed to store a certain volume of runoff
water. This design requires a knowledge of
rainfall parameters.
• The scheduling of construction, mining, and
reclamation operations: These operations
Figure VI-2. Core drilling to gather information on
overburden and coal.
78
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should be scheduled to minimize the area of
soil exposed during periods of heavy and
high-intensity rainfall. Information concern-
ing average precipitation and rainfall inten-
sity for various months is required to sched-
ule such activities properly.
• Selection of plant materials and timing of
revegetation: Climatic variables such as
temperature, radiation, evapotranspiration,
precipitation, and soil moisture storage have
a direct bearing on seed selection and plant
development. Through consultation with
State reclamation personnel, SCS, and de-
partments of forestry and agronomy in State
universities, a seeding plan and planting
schedule should be selected that will be con-
ducive to rapid and sustained plant growth.
Information concerning the climatic variables
is obtainable from local airports and the U.S.
Weather Service. Rainfall intensity, duratipn,
and frequency curves and maps are usually
available from these sources. .-.'.'-
I
CONTROL STRATEGY
The development of a sound erosion and
sediment control strategy tailored to the mine
site and affected off site areas is the third step
in preparing an erosion and sediment control
plan.:
The control rationale presented in section
III outlined the basic principles to be followed
in developing a control strategy. That basic
philosophy must be applied in the development
of a site-specific control strategy, particularly
with respect to the selection of the mining oper-
ations and control measures.
Mining Operations
The development of a control strategy begins
with the selection of mining practices to be used
at the site and the identification of areas to be
disturbed during mining (fig. VI-3). The mining
practices selected are based on site conditions
as defined in the site evaluation, legal con-
straints such as State and Federal regulations,
iS^§S€j-^?'--*iS2j" /";''•**"P*-\v"/'i;
\
Figure VI-3. Area mining in the Midwest.
|79
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r"~ T.'~.~ -, ,,,,,,,,.,.,,,-.,,„..„, , „,
" I'*w-frt>v;*!;;
Figure VI-4. Haulback contour mining in Appalachia.
and an array of other factors, most of which
relate to economics. The overall economic analy-
sis is, of course, influenced by the cost of various
environmental controls, including erosion and
sediment control.
A summary of the basic environmental ad-
vantages and disadvantages of various mining
methods has been described by Hill and Grim in
Environmental Protection in Surface Mining of
Coal.1 From that summary one can ascertain
that certain mining methods such as the block
cut method, mountain top removal, and area
mining generally have, from the standpoint of
soil loss potential, an advantage over other
methods because less land is usually disturbed.
It has been demonstrated2 that, when mining on
a steep slope, erosion and sedimentation are
directly proportional to the amount of land dis-
turbed.
To reduce the opportunity for offsite sedi-
ment damage, the operations should be designed
to limit the amount of land disturbed by retain-
ing as much as possible of the spoil on the site
and minimizing outslope disposal (fig. VI-4).
Spoil placement, disposition, and stabilization
should be well documented in the control plan.
After the mining method has been selected, a
complete schedule of mining operations can be
developed. A schedule of activities is necessary
in order to be able to stage the operations prop-
erly so that both the area and time (i.e., duration
and season) of exposure can be minimized.
Although time is not as tangible as labor, mate-
rials, or equipment, it still remains a critical
element in erosion and sediment control.
Sediment production can be decreased by
reducing the size of the area that is disturbed at
any given time and the length of time during
which any area is left exposed. These two basic
facts call for a control strategy that involves
staging of activities to reduce both the area and
time of exposure.
The location of areas to be mined, access
roads, and other offsite facilities must also be
defined in this stage of the development of a
control strategy. The boundary of the property
to be mined and the location of roadways and
other facilities should be influenced by the
results of the site investigation. This is espe-
cially important when selecting roadway align-
ments and outslope spoil disposal areas.
Multiple uses of access roads is often forgot-
ten in the planning stage. Roads can frequently
be used before mining for logging, and after
mining for access to the mine area for fire pro-
tection, housing developments, hunting, or other
uses. Well-built roads result in faster haulage
time and cost less to maintain.
80
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Control Measures
Once the mining techniques and the boundary
of the property to be mined are known and the
location of access roads and other offsite facili-
ties is established, individual erosion and sedi-
ment control measures can be identified, sited,
arid scheduled.
Sections III, IV, and V of this manual pro-
vide information on control rationale and the use
of various control practices. Section I, volume II,
contains more detailed information on selected
control practices. This information should be
consulted when identifying various erosion and
sediment control measures to be used at a spe-
cific site.
The control strategy must include a combina-
tion of perimeter and internal erosion and sedi-
ment control practices (fig. VI-5). Drainage
upslope of the disturbed areas must be diverted
properly around or through the disturbed area,
and both internal and perimeter control prac-
tices must be deployed to reduce the amount of
sediment leaving the mine site and access roads
and entering waterways.
Scheduling of control measures is also a very
important consideration. Prior to clearing, con-
struction of access roads, or the initiation of
any other earth-disturbing activities, perimeter
control measures, such as diversion structures,
sediment traps, and basins, must be installed
(fig. VI-6). In highly inaccessible areas, some
variance from this general rule will be required
in order to gain access to the site for equipment
needed to construct control measures.
Onsite erosion control and sediment contain-
ment practices should also be implemented in a
timely manner and should be performed concur-
rently with excavation and grading activities.
Revegetation practices require close schedul-
ing. Seasonal considerations, in particular, are
very important in the successful establishment
of vegetation. Seedbed preparation should be
scheduled to coincide as closely as possible with
completion of final grading. Extensive delays
may, in some instances, necessitate the use
of short-term stabilization practices, such as
chemical stabilization, vegetation, or mulching.
, In the identification of control practices,
maintenance considerations must not be over-
looked. Lack of maintenance is a major factor
in the failure of many control programs. The
operator must be constantly on the lookout for
Figure VI-5. Contour furrows and diversion swale controlling erosion and protecting lower lying waterway.
81
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Figure VI-6. Diversion ditch along perimeter of disturbed area.
Figure VI-7. Sediment basin badly in need of cleaning.
82
-------
erosion and sedimentation problems and must
take prompt and effective action to correct
identified problems. Particular attention should
be given to inspecting,and maintaining water-
Handling structures such as diversion, down-
drain, and channel stabilization structures and
sediment traps arid basins (fig. VI-7). Breaches
in stabilization and diversion structures and
the accuriiulation of excessive amounts of sedi-
ment in containment structures should be antici-
pated, and procedures should be identified to
correct such problems. '
The access and haul roads, in particular,
require a thorough maintenance program to
maintain a desirable operating quality and to
control erosion. Stabilization measures, as de-
scribed in section IV, should apply to the road-
base, drainage appurtenances, and cut-and-fill
slopes. Frequent inspections of these elements
should be made to insure their functional integ-
rity.
Considerable attention must also be given
to inspecting and maintaining vegetative
practices. Vegetation is a living material and
requires oxygen, moisture, and nutrients to
survive. Periodic applications of various soil
amendments, such as lime and fertilizers, will be
required to establish a ground cover that will
provide long-term protection against soil ero-
sion. Maintenance requirements can be mini-
mized by selecting plant materials that are
suited to natural site conditions and postmining
land use.
The erosion and sediment control plan should
clearly define both scheduling and maintenance
requirements. For vegetative practices, it should
also specify the following:
Planting location
Species to be used and application rates
Methods of planting or seeding
Seedbed preparation procedures _ •'.
Liming, fertilization, and mulching require-
ments, including types of material to be used
and application rates
Planting schedule
EVALUATION OF PRELIMINARY
SKETCH PLAN
|
(
After the required legal and technical infor- j
mation has been collected and analyzed, and a {
control strategy has been formulated, a pre- j
liminary sketch plan is prepared. This sketch :
plan shows the approximate location of prospec- j
tive access roads, mining areas, and control
structures, and defines procedures to minimize j
erosion and control damage. The sketch plan j
provides the operator, or his engineer, with a
working document that can be taken to the field
to evaluate the feasibility of the plan.
After the preliminary plan has been prepared,
the operator, or his engineer, should contact all
the appropriate Federal, State, and local govern-
ment agency representatives, and schedule an
interdisciplinary field conference at the proposed •
site. Appropriate or responsible government
agencies vary from State to State; however,
representatives from agencies such as the State
division of reclamation, SCS, the department
of natural resources, the U.S. Geological Sur-
vey, and the U.S. Forest Service are generally
included. In addition, any applicable local or
regional governmental agency should be iri-
cluded. In some cases representatives of local
citizen groups, such as the League of Women
Voters, are invited to attend this conference.
A listing of the respective agencies in each State
is provided in section IV, volume II.
" A conference of this type provides the follow-
ing benefits:
• It provides a unique opportunity for an inter-
disciplinary evaluation of the proposed
mining project by a highly skilled group of
professionals
• The inclusion of the responsible government
agencies in the formulation of the control
plan means that delays usually encountered
in obtaining final plan approval will be re-
duced.
• This interdisciplinary approach will balance
the influence of the various individual dis-
ciplines and minimize oversights that could
develop into serious problems at a later date.
• The conference will provide the beginning of
a cooperative effort to mine the mineral re-
source while protecting the environment.
REVISION AND FINALIZATION
OF THE PLAN
Suggestions or revisions resulting from the
field conference are then incorporated with the
preliminary plan and used to prepare a detailed
final plan in accordance with the checklist pro-
vided in table VI-2. This final plan is then sub-
mitted to the responsible government agency
for approval. The plan will either be approved
and a permit issued, or it will be returned for
corrections or revisions. In the latter case, the
corrections or revisions will be made to the final
plan and the plan will then be resubmitted for
approval. A representative erosion and sedi-
ment control plan is presented in section III,
volume II.
83
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REFERENCES
'Elmore C. Grim, and R. D. Hill, Environ-
mental Protection in Surface Mining of Coal,
Environmental Protection Technology Series,
EPA-670/2-74-093, Oct. 1974.
2Design of Surface Mining Systems in East-
ern Kentucky, vol. II, Report ARC-71-66-71,
prepared by Mathematica, Inc., and Ford,
Bacon and Davis, Lexington, Ky., for the Appa-
lachian Regional Commission, 1974.
84
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Section VII
IMPLEMENTATION
Issuance of a mining permit signifies that
the mining plan is an acceptable operational
program designed to maximize productivity and
minimize environmental damage. However, mine
productivity and environmental protection are
not assured by the design of the plan, but by
its successful implementation. It is well recog-
nized that a key to success in nearly all aspects
of surface mining is onsite supervision and
inspection. Just as supervision and inspection
are required for the efficient removal of coal,
these functions must also be applied to achieve
effective sediment control. This on-the-ground
phase of erosion and sediment control is the
responsibility of two field specialists—the mine
operator, or foreman, and the State surface mine
inspector.
INSPECTION RESPONSIBILITIES
To assure that the mining operation is con-
ducted in accordance with the control plan, the
operator and the inspector must function as a
team (fig. VII-1). Their success depends on how
well each of them performs their duties, how
well they work together, and the thoroughness
of their field investigations. Section VII pro-
vides descriptions of the individual responsi-
bilities of the operator and the inspector, and
presents some guidelines for field inspection.
«333ftf*<'»,- . '" *
(ffi^Sfc*1*^***
^itiiisf wgKsJ^^-irv.-.,
~-*ifc;*K5«jL. .•.- ' -',";--.*? .^s»>*^":-r;;
^--^SiT^.'
fe^'^*4^*>fe^;s
^*c,'i«4-;»s?i i>'»«a1-^ "^^s-^
^SSf^JS^iife'/^J^i-
,'
j5»J' -^ *• ^,* :•:* * •••
s-,'' -*&*&••;•• - j*.^.- '?w-_i •
Figure VII-1. Opera'tor-inspectorteam.
m
i
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The Operator's Responsibilities
The man responsible for the day-to-day opera-
tion of the mine, the operator, has possibly the
most important role in coal surface mining. In
addition to mining coal efficiently and rapidly,
he has the equally important jobs of following
the approved mining plan, scheduling the opera-
tion so that everything is kept current, meeting
production schedules, and talking with the
inspector and other State officials.
The operator's performance will determine
the success or failure of the mining operation.
Mine-closing orders or noncompliance citations
often result when the operator fails to carry out
the mining operation as specified in the ap-
proved plan, or when unforeseen problems or
failures develop, and are not corrected.
_ The Virginia Surface Mining and Reclama-
tion Association, drawing from its experience
with mine operators and the general public,
has provided its surface mine operators with a
list of do's and don'ts. This list has been adapted
for general use and is presented below. ',
DO—Buy an inexpensive camera, a .soil-
testing kit, and a water-testing kit. Photo-
graph and test the area before, during, and
after mining. Prepare and maintain a
logbook on each operation, being careful to
note specific facts such as soil and water
pH and silt levels. Sign and date each
entry. Such a log can be extremely useful
should questions arise regarding the spe-
cific effects of the operation on the area
being mined.
DO—Be sure that water impounded on the
bench is released gradually (i.e., pumped :
or siphoned), and that provisions are made
to prevent erosion and siltation of streams.
DO—Keep your (haul and/or access) roads
in good repair and properly ditched. A few
hours each week spent on this work can
save days of costly effort later.
DO—Listen to complaints about your opera-
tion even if the complaining party appears
unreasonable. Try to find out what is really
wanted. If you cannot satisfy his entire
request, a compromise can usually be
worked out. If a difficult situation arises '
regarding- a complaint, seek assistance in
working out a fair settlement.
DO—Advise nearby residents of planned
blasting so they will know what to expect.
If elderly or ill persons are nearby, offer
them transportation to and from a friend's
or relative's home away from the area
during the shot. This is the fair and cour-
teous thing to do.
DO—Keep regrading current. It is hard to
catch up once you get behind.
DO—Obtain designated State or Federal
agency approval of regraded areas before
applying seed and fertilizer. Otherwise,
some expensive reworking could be re-
quired.
DO—Order only certified seed and fertilizer,
far enough in advance to insure delivery
before needed. This will assure that all
arrangements are made in time to prevent
expensive delays. Have a storage area
available if materials must be stored before
delivery to the job.
DO—Be extra careful when working near
homes or public roads. Plan the job,care-
fully, work the job responsibly, and reclaim
the job better than the law requires. Even
though your work might be perfectly
acceptable, you and the industry will be
criticized if the job looks bad.
DO—Perform touchup work on seeding and
fertilizing as soon as rough spots are ap-
parent. The sooner the work is satisfactory,
the sooner you will be released from your
obligations.
DO—Publicize especially good reclamation
work. Make use of available news media
(i.e., newspapers, television, trade maga-
zines, etc.).
DO—Make sure all of your employees under-
stand the importance of handling black
material properly. In 99 percent of the
cases, plants will not grow on the black
material. Even if it is not acid, it will ab-
sorb so much heat from the sun that vege-
tation will not grow.
DON'T—Be too quick to criticize the enforce-
ment agency. These men have a difficult
job, especially with a new law to enforce.
They will be fair if at all possible. Consider-
ation, understanding, and cooperation by
all concerned parties in dealing with a
problem will result in the best possible
solution.
DON'T—Be afraid to ask for assistance if
unexpected difficulties arise. Numerous
State and Federal agencies as well as coal
associations provide technical advice when
needed.
86
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DON'T—Let trucks and equipment run
through a creek. A culvert or a simple
bridge is not costly, and the people down-
stream will not have a muddy creek (fig.
VI1-2). Mining operations can be shut
down for polluting waterways. This can be
costly.
DON'T—Let trucks and equipment run mud
onto a highway. Such a practice is annoy-
ing to the public, can cause accidents, and
in some States is illegal and can result in a
shutdown. I
DON'T—Forget that one careless act can)
make a bad impression for the whole indus-1
• try. I
The Inspector's Responsibilities
The responsibility assigned to the surface
mine inspector is different in every coal pro-
ducing State. However, all inspectors have some
degree of enforcement power that can be exer-
cised when mining laws are violated (fig. VII-3).
The surface mine inspector has the job of
being a spokesman for the State, visiting mining
sites, making reports, and giving technical
guidance. In addition to his role as an inspector,
he oftentimes must serve as engineer, agrono-
mist, and geologist to the mining operator.
General inspection responsibilities that the
mine inspector must carry out include the fol-
lowing:
Figure VI1-2. Protect streams by providing stable crossings
87
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'r•'".-" * I
Figure VII-3. Water sampling below surface mine site.
• Meeting with the operator and becoming
knowledgeable on the type of mining opera-
tion, water-handling practices, and reclama-
tion work.
• Scheduling visits with the operator, especially
at critical times
• Advising mine operators on the best possible
methods of controlling pollution caused by
erosion, sedimentation, and acid mine drain-
age
• Insuring that all phases and aspects of the
active operation are within the constraints of
the law and according to the plan
• Keeping time schedules on the mining and
reclamation phases of the operation to insure
that both phases are being kept as current as
possible
The degree of competence with which an
inspector carries out his responsibilities will
depend on four major factors:
« Training
• Personality
• Incentives
• Intelligence
Training. The surface mine inspector must be
knowledgeable in surface mining technology,
reclamation, State and Federal laws relating to
surface coal mining, and various other dis-
ciplines. Minimum training should include a
balanced combination of classroom and field
training. Classroom training should be sufficient
to make the inspector knowledgeable in the
areas mentioned above. Field training should
be conducted under the supervision of an experi-
enced inspector before the trainee is assigned a
work area.
Personality. It is especially important for a
surface mine inspector to have an agreeable
personality. With each new mining permit the
inspector will meet another operator with a dis-
tinct personality unlike his own. The inspector
must have a personality that is both firm and
businesslike, yet possess an ability to laugh and
be cooperative.
Incentives. Through awards, educational
benefits, and other incentives a sense of pride,
competitiveness, and increased spirit can be
instilled in a very hard and burdensome job.
Intelligence. As in any other technical pro-
fession, the mine inspector must be intelligent
enough to do his job in a knowledgeable and
professional manner. His inspection responsi-
bilities make it necessary for him to acquire
skills in new and often complicated technical
areas. This required knowledge can be gained
88
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through seminars, training sessions, confer-
ences, and meetings dealing with various aspects
of surface mining.
GUIDES FOR INSPECTION AND
EVALUATION OF EROSION AND
SEDIMENT CONTROL MEASURES
ONSITE PLAN REVIEW
Following the issuance of ,a mining permit it
is necessary that the operator and the area
mining inspector meet and review the entire
mining plan in the field. By doing this, the
following objectives can be achieved:
• The inspector can become more familiar with
site conditions that will be affected by the
mining operation. This will help the inspector
when making future visits and assessing
changes in the mining operation and the
mining environment.
• Further discussion can take place between the
operator and the inspector of specific prob-
lems that may be encountered during the
operation (e.g., becoming spoil bound).
• The inspector can make suggestions and pro-
vide information to the operator that may
help the operator mine coal more efficiently,
and remain within the constraints of the law.
• By reviewing the mining plan in the field and
walking the site, the operator and inspector
can begin a cooperative relationship that will
be helpful in achieving both men's goals.
ONSITE INSPECTION
The working relationship between the opera-
tor and the inspector is probably most pro-
nounced in their routine onsite inspection
duties. The operator has the best working knowl^
edge of the site and is in the best position to
take prompt preventive or corrective actions.
The inspector has less working knowledge about
any one site, but has a better overall view of
problems and conditions in the area. The inspec-
tor is in the best position to evaluate objectively
the total performance of the erosion and sedi-
ment control efforts on a site. With these com-
plementary points of view working together, the
onsite inspection can be the most valuable ele-
ment of an entire control program—provided
that inspections are sufficiently thorough. A
partial list of items to be checked on inspection
tours is given below. This list has been adapted
in part from the Sediment Control Inspectors
Handbook of the Maryland Water Resources
Administration.
1. Haul and access roads
a. Alignment
(1) stream crossings
(2) curves
b. Road grades
(1) steepness
(2) length
c. Road base materials
d. Drainage
(I) road cross section
(2) outlet spacing
(3) channel lining
(4) energy dissipators
2. Clearing and grubbing
a. Description of method and equipment
b. Staging schedule
c. Brush and trash disposal
3. Water-handling structures
a. Diversion dike
(1) location
(2) top width
(3) height
(4) machine compaction
(5) side slopes
(6) grade
(7) outlet
(8) vegetative stabilization
b. Interceptor dike
(1) location
(2) top width .'..'
(3) height . ,
(4) side slopes
(5) machine compaction
(6) grade , ,
(7) spacing .
(8) outlet .
(9) vegetative stabilization
Level spreader
(1) location
(2) bottom width
(3) back slope
(4) length
(5) grade
(6) outlet
(7) vegetative stabilization
d. Grassed waterway or outlet
(1) location
(2) depth
(3) width
(4) slope
(5; subsurface
c.
189
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(6) compaction
(7) vegetative stabilization
(8) temporary protection during establish-
ment (when possible)
e. Diversions
(1) location
(2) cross section
(3) grade
(4) outlet
(5) vegetative stabilization
f. Grade stabilization structure, chute, or
flume
(1) location
(2) lining
(3) size and cross section
(4) compaction
(5) slopes
(6) placement of lining
(7) subsurface
(8) outfall
g. Sediment basin
(1) location
(2) size of storage area
(3) pipe spillway
(a) location of riser and barrel
(b) size and elevation of riser and bar-
rel
(c) spacing and size of the perforations
in the upper one-half to 2-thirds of
the riser
(d) antivortex device on top of riser (if
required)
(e) riser base
(f) trash rack (if required)
(g) antiseep collars
(4) emergency spillway (if required)
(a) location
(b) size—bottom, side slopes, length
(c) elevation
(d) vegetative stabilization (or other
suitable means)
(5) embankment (dam)
(a) site preparation
(b) material
(c) compaction (lifts)
(d) size—top width, side slopes, length
(e) elevation (freeboard)
(f) vegetative stabilization (if required)
(6) maintenance cleanout
h. Straw bale dike or berm (extra)
(1) location
(2) size
(3) binding
(4) key trench and backfill
(5) rebar or stake pegging
i. Other as appropriate
4. Stockpiles (topsoil and overburden)
a. Location
b. Water handling
c. Stabilization
(1) vegetative
(2) other
5. Regrading
a. Staging
b. Burial of toxic material
c. Ground water drainage
d. Slope control
(1) steepness
(2) length
e. Soil reconstruction
f. Surface drainage
6. Revegetation
a. Critical area stabilization with temporary
seedings
(1) location
(2) duration of use
(3) site preparation
(4) seedbed preparation (lime, fertilizer,
disking)
(5) seeding (mixture and application meth-
od and rate)
(6) mulching
(7) establishment (cover density and main-
tenance)
b. Critical area stabilization with semi-
permanent and permanent seedings
(1) location
(2) duration of use
(3) soil conditions (long-lived vegetative
cover)
(4) site preparation
(5) seedbed preparation (lime, fertilizer,
disking)
(6) seeding (mixture and application meth-
od and rate)
(7) mulching
(8) establishment (cover density, mainte-
nance, and irrigation, if necessary)
c. Critical area stabilization with mulching
only
(1) location
(2) duration of use
(3) site preparation
(4) mulching (materials and application,
cover density)
(5) mulch anchoring
d. Critical area stabilization with Bermuda-
grass, grasses, and legumes
(1) location
(2) site conditions (limitations)
(3) site preparation
(4) soil preparation
(5) establishment (sprigging)
(6) maintenance
e. Critical area stabilization with sod
90
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f.
(1) location
(2) soil preparation ,(lime, fertilizer, and
tillage)
(3) sod materials and installation
(4) maintenance (watering, and mowing)
Critical area stabilization with ground cov-
ers, vines, shrubs, and trees
(1) location
(2) planting time
(3) soil preparation
(4) mulching
(5) maintenance
g. Topsoiling
(1) location
(2) subsoil preparation
(3) topsoil material and application
191
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Section VIII
GLOSSARY
AASHO classification (soil engineering).—The
official classification of soil materials and
soil aggregate mixtures for highway con-
struction used by the American Association
of State Highway Officials.
Abandoned mine.—A mining operation where
coal is no longer being produced and it is the
intent of the operator not to continue pro-
duction from the mine.
Abrasion.—The wearing away by friction, the
chief agents being currents of water or wind
laden with sand and other rock debris, and
glaciers.
Access road.—Any haul road or other road con-
structed, improved, maintained, or used by
the operator that ends at the pit or bench, and
is located within the area of land affected.
Acid-producing materials (acid forming).—
Rock strata containing significant pyrite,
which if exposed by coal mining will, when
acted upon by air and water, cause acids to
form.
Acid soil.—Generally, a soil that is acid through-
out most or all of the parts of it that plant
roots occupy. Commonly applied to only the
surface-plowed layer or to some other specific
layer or horizon of a soil. Practically, this
means a soil more acid than pH 6.6; pre-
cisely, a soil with a pH value less than 7.0.
A soil having a preponderance of hydrogen
over hydroxyl ions in the soil solution.
Acid spoil. —See also Spoil; Toxic spoil. Usually
spoil material containing sufficient pyrite
so that weathering produces acid water and
the pH of the soil determined by standard
methods of soil analysis is between 4.0 and
6.9.
Active surface mine operation. — A mining oper-
ation where land is being disturbed in prepa-
ration for and during the removal of a min-
eral.
Agglomeration.—The uniting of dispersed sus-
pended matter into larger floes or particles
that settle rapidly.
Aggregation, soil.—The cementing or binding
together of several soil particles into a sec-
ondary unit, aggregate, or granule. Water-
stable aggregates, which will not disintegrate
easily, are of special importance to soil struc-
ture.
Agricultural limestone.—Contains sufficient
calcium and magnesium carbonate to be
equivalent to not less than 80 percent calcium
carbonate and must be fine enough so that
not less than 90 percent shall pass through a
U.S. Standard No. 10 sieve and not less than
35 percent shall pass through a U.S. Standard
No. 50 sieve.
Alkaline soil.—Generally, a soil that is alkaline
throughout most or all of the parts of it occu-
pied by plant roots, although the term is
commonly applied to only a specific layer or
horizon of a soil. Precisely, any soil horizon
having a pH value greater than 7.0. Prac-
tically, a soil having a pH above 7.3.
Amendment.—Any material, such as lime,
gypsum, sawdust, or synthetic conditioners,
that is worked into the soil to make it more
productive. Technically, a fertilizer is also an
amendment, but the term amendment is used
most commonly for added materials other
than fertilizer.
Angle of dip.—The angle an inclined stratum
makes with the horizontal.
Annual plant (annuals).—A plant that com-
pletes its life cycle and dies in 1 year or less.
Area mining. —Surface mining that is carried on
in level to gentle rolling topography on rela-
tively large tracts.
Aspect.—The direction toward which a slope
faces. Exposure.
Available nutrient.—The part of the supply of
a plant nutrient in the soil that can be taken
up by plants at rates and in amounts signifi-
cant to plant growth.
Back blade. —In regrading, to drag the blade of
a bulldozer or grader in the down position as
the machine moves backward, as opposed to
pushing the blade forward.
193
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Backfill.—The operation of refilling an excava-
tion. Also the material placed in an excava-
tion in the process of backfilling.
Basin.—A natural depression of strata contain-
ing a coal bed or other stratified deposit.
Bedload. —The sediment that moves by sliding,
rolling, or bouncing on or very near the stream-
bed. Sediment moved mainly by tractive or
gravitational forces, or both, but at velocities
less than the surrounding flow.
Bench.—The surface of an excavated area at
some point between the material being mined
and the original surface of the ground on
which equipment can set, move, or operate.
A working road or base below a highwall, as
in contour stripping for coal.
Berm.—A strip of coal left in place temporarily
for use in hauling or stripping. A layer of
large rock or other relatively heavy stable
material placed at the outside bottom of the
spoil pile to help hold the pile in position (a toe
walk). Also used similarly higher in the spoils
for the same purpose.
Biennial plant.—A plant that requires 2 years
to complete its life cycle.
Broadcast seeding.—Scattering seed on the sur-
face of the soil. Contrast with Drill seeding,
which places the seed in rows in the soil.
Buffer strip. — 1. Unaffected areas between the
mining operation and areas designated for
other public and private use.
2. Strips of grass or other erosion-resisting
vegetation between or below surface or auger
mining disturbances.
Bunchgrass.—A grass that does not have
rhizomes or stolons and forms a bunch or tuft.
Calcareous soil.—Soil containing sufficient cal-
cium carbonate (often with magnesium car-
bonate) to effervesce visibly when treated
with cold 0.1 normal hydrochloric acid.
Canopy.—The cover of leaves and branches
formed by the tops or crowns of plants.
Channel stabilization.—Erosion prevention and
stabilization of velocity distribution in a
channel, using jetties, drops, revetments,
vegetation, and other measures.
Check dam.—Small dam constructed in a gully
or other small water course to decrease the
streamflow velocity, minimize channel scour,
and promote deposition of sediment.
Chute.—See section I, volume II.
Clay (soils). — 1. A mineral soil separate consist-
ing of particles less than 0.002 mm in equiva-
lent diameter.
2. A soil textural class.
3. (engineering). A fine-grained soil that has
a high plasticity index in relation to the liquid
limits.
Clearing.— The removal of vegetation, struc-
tures, or other objects in preparation for earth-
moving activities.
Climate.—The sum total of all atmospheric or
meteorological influences, principally temper-
ature, moisture, wind, pressure, and evapo-
ration, that combine to characterize a region
and give it individuality by influencing the
nature of its land forms, soils, vegetation, and
land use. Contrast with Weather.
.Clinker.—Sometimes referred to as scoria, &
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 exten-
sively as a road-surfacing material. Clinkers
are similar to Red dog.
Clod.—A compact, coherent mass of soil ranging
in size from 5 to 10 mm (0.2 to 0.4 inches) to
as much as 200 to 250 mm (8 to .10 inches);
produced artificially, usually by the activity
of man by plowage, digging, etc., especially
when these operations are performed on soils
that are either too wet or too dry for normal
tillage operations.
Coagulation.—The destabilization and initial
aggregation of colloidal and finely divided
suspended matter by the addition of a floe-
forming chemical.
Coal seam.—A layer, vein, or deposit of coal. A
stratigraphic part of the earth's surface con-
taining coal.
Coarse texture. —The texture exhibited by sands
and loamy sands. A soil containing large
quantities of these textural classes (U.S.
usage).
Compaction.—The closing of the pore spaces
among the particles of soil and rock, generally
caused by running heavy equipment over the
area as in the process of leveling the over-
burden material of strip mine banks.
Conifer.—A tree belonging to the order
Coniferae, usually evergreen with cones and
needle-shaped or scalelike leaves, and pro-
ducing wood known commercially as soft-
wood.
Conservation.—The protection, improvement,
and use of natural resources according to
principles that will assure their highest eco-
nomic or social benefits.
Contour. —An imaginary line connecting points
of equal height above sea level as they follow
the relief of the terrain.
Contour stripping or surface mining. —-The re-
moval of overburden and mining from a coal
94
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seam that outcrops or approaches the surface:
at approximately the same elevation, in steepj
or mountainous areas. [
Cool-season plant.—A plant that makes its'
major growth during the cool portion of tha
year, primarily in the spring, but in somej
localities in the winter. |
Core drilling.—The process by which a cylindri-!
cal sample of rock and other strata is obtained'
through the use of a hollow drilling bit thatj
cuts and retains a section of the rock or other|
strata penetrated. - I
Corrasion. —The wearing away of earth mate-1
rials through the cutting, scraping, scratch-)
ing, and scouring effects of solid material!
carried in the currents of water or air.' j
.Coyer crop.—A close-growing crop grownj
primarily for the purpose of protecting and;
improving soil between periods of regular)
crop production or between trees and vines j
in orchards and vineyards. |
Cover, ground.—Any vegetation producing a
protecting mat on or just above the soil sur-
face. In forestry, low-growing shrubs, vines,
and herbaceous plants under the trees.
Cover, vegetative.—All plants of all sizes andj
species found in an area, irrespective of I
whether they have forage or other value. |
Cover, wildlife.—Plants or objects used by wild)
animals for nesting, raising of young, escape I
from predators, or protection from adverse i
environmental conditions. , j
Crust;—A dry surface layer on soils that is much i
more compact, hard, and brittle than the
material immediately beneath it.
Culvert.—A closed conduit for the free passage j
of surface drainage water under a roadway or |
other embankment. . j
Cut.—Longitudinal excavation made b,y a strip- j
. .mining machine to remove overburden in a{
single progressive line from one side or end ofj
the property being mined to the other side or
end.
Cut-and-f ill.—Process of earth moving by exca-
vating part of an area and using the excayated )
material for adjacent embankments or fill j
areas.
Density, forage.—The percentage of ground I
surface that appears to be completely covered j
by vegetation when viewed directly from )
above,
Density stand.—Density of Stocking expressed !
in number of trees per acre.
Deposition.—The accumulation of material
dropped because of a slackening movement
of the transporting agent—water or wind.
Detachment.—The removal of transportable
fragments of soil material from a soil mass
by an eroding agent, usually falling rain-
drops, running water, or wind. Through
, detachment, soil particles or aggregates are
made ready for transport—soil erosion.
Direct seeding.—A method of establishing a
stand of vegetation by sowing seed on the
ground surface.
Diversion.—Channel constructed across the
slope for the purpose of intercepting surface
runoff. Changing the accustomed course of
all or part of a stream.
Diversion dike.—See section I, volume II.
Diversion swale (ditch).—See section I, volume
II.
Dragline.—An excavating machine that utilizes
a bucket operated and suspended by means
, of lines or cables, one of which hoists or lowers
, the bucket from a boom; the other, from
which the name is derived, allows the bucket
to swing out from the machine or to be
, dragged toward the machine for loading.
Mobility of draglines is by crawler mounting
or by a walking device for propelling, featur-
ing pontoonlike feet and a circular base or
tub. The swing of the machine is based on
rollers and rail. The machine usually operates
. from the highwall.
Drainage.—The removal of excess surface water
or ground water from land by means of sur-
face or subsurface drains.
Drill seeding.—Planting seed with a drill in
relatively narrow rows, generally less than a
foot apart..Contrast with Broadcast seeding.
Droughty. —Exhibiting a poor moisture-holding
• capacity due to excessively high permeability
and a low percentage of fines.
Dugout pond.—An excavated pond as con-
. trasted with a pond formed by constructing a
dam.
Emergency spillway.—A spillway used to carry
runoff exceeding a given design flood.
Energy dissipators. — See section IV, "Handling
Disposal of Concentrated Flows."
Environment. —The sum total of all the external
, conditions that may act upon an organism or
community to influence its development or
existence.
Erodible (geology and soils). —Susceptible to
erosion.
Erosion. —1. The wearing away of the land sur-
face by running water, wind, ice, or other
geological agents, including such processes
as gravitational creep.
, 2. Detachment and movement of soil or
rock fragments by water, wind, ice, or gravity.
95
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The following terms are used to describe dif-
ferent types of water erosion:
Accelerated erosion: Erosion much more
rapid than normal, natural, or geologic
erosion, primarily as a result of the influ-
ence of the activities of man or, in some
cases, of other animals or natural- catas-
trophies that expose base-surfaces, for
example, fires.
Geological erosion: The normal or natural
erosion caused by geological processes
acting over long geologic -periods and
resulting in the wearing away of mountains,
the building up of floodplains, coastal
plains, etc. Syn: Natural erosion.
Gully erosion: The erosion process whereby
water accumulates in narrow channels,
over short periods, and removes the soil
from this narrow . area to considerable
depths, ranging from 1 to 2 feet to as much
as 75 to 100 feet.
Natural erosion: Wearing away of the earth's
surface by water, ice, or other natural
agents under natural environmental con-
ditions of climate, vegetation, etc., undis-
turbed by man. Syn.: Geological erosion.
Normal erosion: The gradual erpsion of land
used by man which does not greatly exceed
^ natural erosion. See Natural erosion.
Rill erosion: An erosion process in which
numerous small channels, only several
inches deep are formed. Occurs mainly on
recently cultivated soils. ,
Sheet erosion: The removal of a fairly uni-
form layer of soil from the land surface by
runoff water.
Splash erosion: The spattering of small soil
particles caused by the impact of raindrops
on wet soils. The loosened and spattered
particles may or may not be removed sub-
sequently by surface runoff.
Erosive.—Refers to wind or water haying suffi-
cient velocity to cause erosion. Not to be
confused with Erodible as a quality of soil.
Esthetic.—Of beauty; beautiful.
Evapotranspiration.—A collective term mean-
ing the loss of water to the atmosphere from
both evaporation and transpiration by vege-
tation.
Excelsior blanket.—See section II, volume II.
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 physi-
cal conditio'n of the soil are favorable.
Fertilizer. — Any natural or manufactured mate-
rial added to the soil in order to supply one or
more plant nutrients.
Fertilizer grade.—The guaranteed minimum
analysis in whole numbers, in percent, of the
major plant nutrient elements contained in a
fertilizer material or in a mixed fertilizer. For
example, a fertilizer with a grade of 20-10-5
contains 20 percent nitrogen (N), 10 percent
available phosphoric acid (P2OS), and 5 per-
cent water-soluble potash (K2O). Minor ele-
ments may also be included. Recent trends
'are to express the percentages in terms of
, ' the elemental fertilizer nitrogen (N), phos-
' phorus (P), and potassium (K). . .
Fertilizer requirement. — The quantity of certain
. plant nutrient elements needed, in addition
to the amount supplied by the soil, to increase
_ plant growth to a designated optimum.
Fibrous root system.—A plant root system
having a large number of small, finely divided,
widely spreading roots but no large individual
_ roots. Usually a characteristic of most grasses.
Field capacity (field moisture capacity).—The
amount of soil water remaining in a soil after
the free water has been allowed to drain away
for a day or two if the root zone has been
previously saturated. It is the greatest
amount of water that the soil will hold under
; conditions of free drainage, usually expressed
as a percentage of the oven-dry weight of soil
'or other convenient unit.
Filter (sediment).—See section V, "Sediment
; Traps."
Filter strip.—Strip of vegetation that retards
flow of runoff water, causing deposition of
transported material, thereby reducing sedi-
ment flow. . . '
Final cut.—Last cut or line of excavation made
on a specific property or area.
Flocculation. —The process by which suspended
colloidal or very fine particles are assembled
, into larger masses or floccules, which.even-
tually settle out of suspension. .
Flume.—See section I, volume II.
Fly ash.—All solids, ash, cinders, dust, soot, or
other partially incinerated matter that is car-
ried in or removed from a gas stream. Fly ash
is usually associated with electric generating
plants.
Forage. —Unharvested plant material that can
be used as feed by domestic animals. Forage
i may be grazed or cut for hay. ,.
Gabion.—A mesh container used to confine
rocks or stones and used to construct dams
and groins to line stream channels.
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Geology.—The science that deals with the his-
tory of the earth and its life as recorded in
rocks.
Georgia V-ditch. —Grading is performed to
create positively draining swales midpoint
between the parallel to the high wall and long-
wall to convey water runoff to drains estab-
lished to carry the water away from the spoil'
area. |
Germination. — Sprouting; beginning of growth.
Grade. — 1. The slope of a road, channel, or natu-
ral ground. ' I
2. The finished surface of a canal bed, I
roadbed, top of embankment, or bottom of!
excavation; any surface prepared for the (sup- i
port of construction, like paving or laying a!
conduit. I
3. To finish the surface of a 'canal bed, road- i
bed, top of embankment, or bottom of exca-1
vation. ' ' ..','",.!
Grade stabilization structure.—A structure for !
the purpose of stabilizing the grade of a gully I
or other watercourse, thereby preventing j
further headcutting or lowering of the channel j
• grade. i
Grassed waterways.—See section I, volume II. !
Green manure crop.—Any crop grown for the
purpose of being turned under while green, or
soon after maturity for soil improvement.. !
Ground water. —Subsurface water occupying I
the saturation zone, from which wells and 1
springs are fed. In a strict sense the, term j
applies only to water below the water'table., i
Also called plerotic water, phreatic water. '
Grouted.—Having the area between pieces of i
rock, brick, etc., filled with mortar or con- j
crete. ; \
Growing season.—The season that, in general,
is warm enough for the growth of plants, the
extreme average limits of duration being
from the average date of the last killing frost J
in spring to that of the first killing ffo'st in j
• autumn. On the whole, however, the growing
season is confined to that period of the year
when the daily means are above 42° F. .. ,,
Grubbing.—The operation of removing stumps
and roots. ' '
Habitat.—The environment in which the life I
needs of a plant or animal are supplied. '
Hardpan.—A hardened soil layer in the lower A j
or in the B horizon caused by cementation of I
soil particles with organic matter or with j
materials such as silica, sesquioxides, or, i
calcium carbonate. The hardness does not
change appreciably with changes in moisture
content, and pieces of the hard layer do not
slake in water. . ..
Haul road. —Road from pit to loading dock,
tipple, ramp, or preparation plant used for
transporting mined material by truck.
Head of the hollow (also valley fill method).—
Basically, overburden material from adjacent
contour or mountain top mines is placed in
compacted layers in narrow, steep-sided
hollows so tlv.'i, surface drainage is possible.
^Heaving.—The partial lifting of plants out of
' •: the ground, 'frequently breaking their roots,
,as a result of freezing and thawing of the sur-
. face soil during the winter.
High wall.—The unexcavated face of exposed
overburden and coal in a surface mine or the
' face or bank on the uphill side of a contour
'strip mine excavation.
Hydrology.—The science that relates to the
"•• water systems of the earth.
Hydroseeding.—Dissemination of seed hydrau-
lically in a water medium. Mulch, lime, and
- fertilizer can be incorporated into the sprayed
* mixture. •
Impervious soil.—A soil through which water,
> air,- or roots cannot penetrate. No soil is
' impervious to water and air all the time.
Impoundment.—A reservoir for collection of
water. Collection of water by damming a
; ••• stream or 'the like. Used in connection with
-' the storage of tailings from a mine.
Infiltration.—The flow of a liquid into a sub-
stance through pores or other openings,
• connoting flow into a soil in contradistinction
to percolation, which connotes flow through a
porous substance.
Inlet.—The upstream end of any structure
through which water may flow.
Inoculation.—The process of adding cultures of
symbiotic micro-organisms to legume seed
to enhance atmospheric nitrogen fixation.
Interceptor dike (straw bale).—See Diversion
dike, section I, volume II.
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 no long-continued supply
from melting snow or other sources. It is dry
for a large part of the year, ordinarily more
than 3 months.
Land use planning.—The development of plans
for the uses of land that, over long periods,
will best serve the general welfare, together
.with the formulation of ways and means for
achieving such uses.
97.
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Landslide.—The failure of a slope in which the
movement of the mass takes place along in-
terior surfaces of sliding.
Leaching.—The removal of materials in solution
by the passage of water through soil.
Legume.—A member of the legume or pulse
family, Leguminosae. One of the most impor-
tant and widely distributed plant families.
The fruit is a legume, or pod that opens
along two sutures when ripe. Flowers are usu-
ally papilionaceous (butterflylike). Leaves
are alternate, have stipules, and are usually
compound. Includes many valuable food and
forage species, such as the peas, beans, pea-
nuts, clovers, alfalfas, sweet clovers, les-
pedezas, vetches, and kudzu. Practically all
legumes are nitrogen-fixing plants.
Level spreader.—See section I, volume II.
Lime.—Lime, from the strictly chemical stand-
point, refers to only one compound, calcium
oxide (CaO); however, the term lime is com-
monly used in agriculture to include a great
variety of materials that are usually com-
posed of the oxide, hydroxide, or carbonate
of calcium or of calcium and magnesium. The
most commonly used forms of agricultural
lime are ground limestone (carbonates), hy-
drated lime (hydroxides), burnt lime (oxides),
marl, and oyster shells.
Lime requirement.—The amount of standard
ground limestone required to bring a 6.6-inch
layer of an acre (about 2 million pounds of
mineral soils) of acid soil to some specific
lesser degree of acidity, usually to slightly
or very slightly acid. In common practice,
lime requirements are given in tons per acre
of pure limestone, ground finely enough so
that all of it passes a 10-mesh screen arid at
least half of it passes a 100-mesh screen.
Limestone.—A sedimentary rock composed of
calcium carbonate, CaCO3. There are many
impure varieties.
Litter.—Freshly fallen or slightly decomposed
organic debris.
Loess.—Material deposited by wind and con-
sisting of predominantly silt-sized particles.
Log-and-pole structure.—See section V, "Types
of Control."
Microclimate.—A local climatic condition near
the ground resulting from modification of
relief, exposure, or cover.
Micro-organism.—Any living thing that is
microscopic or submicroscopic in size.
Mined land.—Land with new surface charac-
teristics due to the removal of mineable
commodity by surface mining methods and
subsequent surface reclamation.
Mountain top removal. — In this mining method,
100 percent of the overburden covering a coal
seam is removed in order to recover, 100 per-
cent of the mineral. Excess spoil material is
hauled to a nearby hollow to create a valley
fill.
Mulch.—Natural or artificial material used to
provide more desirable moisture and tempera-
ture relationships for plant growth. It is also
used to control unwanted vegetation.
Natural drainway. —Any water course that has
a clearly defined channel, including inter-
mittent 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 over-
come an acid condition.
Nitrogen fixation.—The conversion of atmos-
pheric (free) nitrogen to nitrogen compounds.
In soils the assimilation of free nitrogen from
the air by soil organisms (making the nitro-
gen eventually available to plants). Nitrogen
fixing organisms associated with plants such
as the legumes are called symbiotic; those
not definitely associated with plants are
called nonsymbiotic.
Nutrients.—Any element taken into a plant
that is essential to its growth.
Operation.—All of the premises, facilities, rail-
road loops, roads, and equipment used in the
process of extracting and removing a mineral
commodity from a designated surface mine
or in the determination of the location, qual-
ity, and quantity of a natural mineral deposit.
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.
Orphan lands.—Disturbed surfaces resulting
from surface mines that were inadequately
reclaimed by the operator and for which he
no longer has any fixed responsibility. Usu-
ally refers to lands mined previous to the
passage of comprehensive reclamation laws.
Outfall.—The point where water flows from a
conduit, streanr, or drain.
Outslope.—The exposed area sloping away
from a bench cut section.
Overburden.—The earth, rock, and other mate-
rials that lie above the coal.
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Perennial plant.—A plant that normally lives
for 3 or more years.
Permeability.—The quality of a soil horizon
that enables water or air to move through it.
• The permeability of a soil may be limited by
the presence of one nearly impermeable hori-
zon'even though the others are permeable.
pH. —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 condi-
tions. .
Piping.—Removal of soil material through sub-
surface flow channels or "pipes" developed
by seepage water.
Pit.—Used in reference to a specifically describ-
able area of open-cut mining. May be used to
refer to only that part of'the open-cut mining
area front which coal is being actively re-
moved or may refer to the entire contiguous
mined area.
Pitch.—See Angle of dip. :>
Plant nutrients.^-The elements or groups of
elements taken in by-a plant that are essential
to its growth and used -itv elaboration of its
food arid tissues. Includes nutrients obtained
, from fertilizer ingredients.
Planting season.—The period of the year when
planting or transplanting is considered advis-
able from the standpoint of successful estab-
lishment.
Pollution.—Environmental degradation result-
ing from man's activities or natural events.
Pond.—A body of water of limited size either
naturally or artificially confined and usually
smaller than a lake.
Preplanning.—Process of foreseeing reclama-
tion problems and determining measures to
minimize offsite damages during the mining
operation and to provide fe>r quick stabiliza-
tion of the mining. !. -
Puddled soil.—A dense soil/dominated by mas-
1 sive or single-grain structure, almost imper-
vious to air and water. This condition results
' from handling a soil when it is in a wet plastic
condition so that when it dries it becomes
hard and cloddy. :
"Pyrite.—A yellowish mineral, iron disulfide,
FeS2, generally metallic': appearing. Also
known as fool's gold. :
- . .-•'•.. ' . ; -; > - - . • '
Rain. —1. Heavy: Rain that is falling at the time
of observation with an intensity in excess of
0.30 inch per .hour (over. Q<03 inch in 6 min-
utes). .....''. -r
2. Light: Rain that is falling at the time of
observation with an intensity of between a
trace and 0.10 inch per hour (O.Ol inch in 6
minutes). •: * '."
3. Moderate: Rain that is falling at the
time of observation with an intensity of
between 0.11 inch per hour (0.01+ inch in 6
'minutes),and 0.30 inch per hour (0.03 inch in
6 minutes).
Reclamation^—The process of reconverting
mined land to, its former or other productive
• uses,
Red dog.--A gob pile after it has burned. The
material is generally used as a road-surfacing
material; it has no harmful acid or alkaline
reaction. .
Reforestation.—The natural or artificial re-
stocking of an area with forest trees.
Regrading.—The movement of earth over a
surface or depression to change the shape of
the land surface. .
Rehabilitation.—Implies that the land will be
returned to a form and productivity in con-
formity with a prior land use plan, including
a stable ecological state that does not con-
tribute, substantially to environmental de-
terioration and is consistent with surrounding
esthetic values. • ,
Retention.—The amount of precipitation on a
drainage area that does not escape as runoff.
/It is:the difference between the total precipi-
tation and total runoff.
Revegetation.—Plants or growth that replaces
original ground cover following land disturb-
ance.
Reverse terrace. —See Georgia V-ditch.
Revetment.—A facing of stone or other material,
either permanent or temporary, placed along
the edge of a stream to stabilize the bank arid
protect it from the erosive action of the
stream.
Rhizome.—A horizontal underground stern,
usually sending out roots and abovegrourid
shoots at the nodes. . . .
Riprap.—Broken rock, cobbles, or boulders
placed on earth surfaces, such as the face of
a dam or the bank of a stream, for protection
against the action of water (waves). Also ap-
plied to brush or pole mattresses, or brush
and stone, or other similar materials used for
soil erosion control.
Rock-fill dam.—A dam composed of loose rock
^usually dumped in place, often with the up-
, stream part constructed of handpacked or
derrick-placed rock and faced with rolled
earth or with an impervious surface of con-'
crete, timber, or steel. ,
99
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Runoff.—That portion of the precipitation on
a drainage area that is discharged from the
area in stream channels. Types include sur-
face runoff, ground water runoff, or seepage.
Sand.—A soil particle between 0.074 (#200
Sieve) and 4.76 (#4 sieve) millimeters in
diameter.
Sandstone.—A cemented or otherwise com-
pacted detrital sediment composed predomi-
nantly of quartz grains, the grades of the
latter being those of sand.
Scalping.—Removal of vegetation before min-
ing.
Scarify.—To loosen or stir the surface soil
without turning it over. Also, in the case of
legume seeds, abrasion of the hard coat to
decrease time required for germination.
Scheduling.—Chronological ordering of various
stages of surface mining operations to mini-
mize time and duration of exposure.
Scour.—The wearing away of terrace or diver-
sion channels or streambeds.
Seam. —A stratum or bed of coal.
Sediment.—Solid material, both mineral and
organic, that is in suspension, is being trans-
ported, or has been moved from its 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.
Sediment basin.—See section I, volume II.
Sediment trap.—See section I, volume II.
Sediment yield.—The total amount of sediment
that passes any section of a stream.
Seedbed. —The soil prepared by natural or arti-
ficial means to promote the germination of
seed and the growth of seedlings.
Seep.—A more or less poorly defined area where
water oozes from the earth in small quanti-
ties.
Selected earth material.—Suitable native mate-
rial obtained from roadway cuts or borrow
areas, or other similar material, used for
subbase, roadbed material, shoulder sur-
facing, slope cover, or other specific purposes.
Semiarid,—A term applied to regions or cli-
mates where moisture is normally greater
than under arid conditions but still definitely
limiting to the growth of most crops. Dry-
land farming methods or irrigation generally
is required for crop production. The upper
limit of average annual precipitation in the
cool semiarid regions is as low as 38 cm (15
inches), whereas in tropical regions it is as
high as 114 to 127 cm (45 or 50 inches).
Shale.—Sedimentary or stratified rock struc-
ture generally formed by the consolidation of
clay or claylike material.
Sheet flow.—Water, usually storm runoff, flow-
ing in a thin layer over the ground surface.
Syn.: overland flow.
Side slopes.—The slope of the sides of a canal,
- dam, or embankment. It is customary to
name the horizontal distance first as 1.5 to
1.0, or frequently IVfe: 1, meaning a horizontal
distance of 1.5 feet to 1 foot vertical.
Silage.—A crop that has been preserved in a
moist succulent condition by partial fer-
mentation. Chief silage crops are corn,
sorghums, and various legumes and grasses.
Silt. — Small mineral soil grains, the particles of
which range in diameter from 0.05 to 0.002
mm (or 0.02-0.002 mm in the international
system).
Slope characteristics. —Slopes may be charac-
terized as concave (decrease in steepness in
lower portion), uniform, or convex (increase
in steepness at base). Erosion is strongly
affected by shape, ranked in order of increas-
ing erodibility from concave to uniform to
convex.
Slope stability.—The resistance of any inclined
surface, as the wall of an open pit or cut, to
failure by sliding or collapsing.
Sludge.—The precipitate resulting from chemi-
cal treatment of water, coagulation, or sedi-
mentation.
Sod.—A closely knit ground cover growth,
primarily of grasses.
Soil. —1. The unconsolidated mineral and or-
ganic material on the immediate surface of
the earth that serves as a natural medium
for the growth of land plants.
2. The unconsolidated mineral matter on
the surface of the earth that has been sub-
jected to and influenced by genetic and
environmental factors of parent material,
climate (including moisture and temperature
effects), macro- and micro-organisms, and
topography, all acting over a period of time
and producing a product soil that differs
from the material from which it is derived in
many physical, chemical, biological, and
morphological properties and characteris-
tics.
3. A kind of soil; that is, the collection of
soils that are alike in specified combinations
of characteristics. Kinds of soil are given
names in the system of soil classification.
The terms the soil and soil are collective.
Soil conservation. — Protection of the soil
against physical loss by erosion or against
chemical deterioration; that is, excessive loss
of fertility by either natural or artificial
means.
Soil series.—The basic unit of soil classification
being a subdivision of a family and consisting
100
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of soils that are essentially alike in all majorj
profile characteristics except the texture of
the A horizon. '
Soil structure.—The combination or arrange-
ment of primary soil particles into secondary,
particles, units, or peds. i
Soil survey.—A general term for the systematic'
examination of soils in the field and in labora-j
tories; their, description and classification;'
the mapping of kinds of soil; the interpreta-:
tion of soils according to their adaptability
for various crops, grasses, and trees; their
behavior under use or treatment for plant!
production or for other purposes. I
Soil texture. — Soil texture class names of soils!
are based upon the relative percentages of;
sand, silt, and clay.
Spoil.—See also Acid spoil; Toxic spoil. The
overburden or noncoal material removed in[
gaining access to the coal or mineral material i
in surface mining. !
Spoil bank (spoil pile).—Area created by thej
deposited spoil or overburden material prior'
to backfilling. Also called cast overburden.
Sprigging. —The planting of a portion of thei
stem and/or root of grass. . j
Stabilize.—Settle, fix .in place, make non-!
moving, usually accomplished on overburden)
. ,by planting trees, shrubs, or grasses, or by|
mechanical compaction or^aging. \
Staging.—Arrangement of major mining opera-j
tions, such as clearing, grubbing, and scalp-1
ing, into small discrete segments so that at j
any one time the various phases of clearing,!
extraction, and reclamation can be carried on |
simultaneously. I
Stand. — 1. An aggregation of trees or other j
growth occupying a specific area and suffi-j
ciently uniform in composition (species), age
arrangement, and condition to be distinguish-
able from the forest or; other growth on j
. adjoining areas. |
2. The number of plants per unit of area
other than trees. ,• . . ;
Stolon. — A horizontal stem that grows along
the surface of the soil and roots at the nodes. I
Stratified. — Composed of, or arranged in, strata !
or layers, as stratified alluvium. The,term is }
, applied to geological materials. Those layers i
in soils that are produced,by the processes of j
soil formation are called horizons, while those I
inherited from parent material are called
.L strata,. , , • , . . j
Strip mine. —Refers to a procedure of mining j
, that entails the complete removal of all mate- i
rial from over the product to be mined in a j
series of rows or strips; also referred to as '\
open cut, open pit, or surface mine. . \
Subsoil.—The B horizon of soils with distinct
profiles. In soils with weak profile develop-
, ment, the subsoil can be defined as the soil
below the plowed soil (or its equivalent of sur-
face soil) in which roots normally grow. Al-
though a common term, it cannot be defined
accurately. It has .been carried over from
early days when soil was conceived only as
the plowed soil and that under it as subsoil.
Surface mining.—Mining method whereby the
overlying materials are removed to expose
the mineral for extraction.
Surface soil.—That part of the upper soil of
arable soils commonly stirred by tillage
implements or an equivalent depth (5 to 8
inches) in npnarable soils.
Surface water.—Water, from whatever source,
that is flowing on the surface of the ground.
Suspended solids. — Sediment that is in suspen-
sion in water but,that will physically settle
out under. quiescent conditions (as differenti-
ated from dissolved material).
Swale.—A hollow or depression.
Syncline.—A fold of rock beds that is convex
downward. . ,
Tacking (mulch). —The process of binding
mulch fibers together by the addition of a
sprayed chemical compound.
Terrace.—An embankment or combination of an
embankment and channel constructed across
a slope to control erosion by diverting. .
Terrace outlet channel. —Channel, usually hav-
ing a vegetative cover, into which the flow
from one or more terraces is discharged and
conveyed from the field.
Terrace types.— Absorptive: A ridge type of
terrace used primarily for moisture conserva-
tion. .•• •:'•;.-.:-.•
Bench: A terrace approximately on the
contour, having a steep or vertical drop to
',••• the slope below, and having a horizontal or
.gentle sloping part. It-is adapted to steeper
slopes. • •
Drainage: A broad, channel-type terrace
used primarily to conduct water from the area
at a low velocity. It is adapted to less absorp-
tive soil and regions of high rainfall. '
Texture.—The character, arrangement, and
mode of aggregation of particles that make
,;, up the earth's surface. -
Tillage equipment (tools). —Field tools and ma-
chinery that are designed to lift, invert, stir,
. or pack soil, reduce size of clods and uproot
weeds; i.e., plows, harrows, discs, and culti-
vators.
101
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Toe.—The point of contact between the base of
an embankment or spoil bank and the founda-
tion surface. Usually the outer portion of the
spoil bank where it contacts the original
ground surface.
Tolerant.—Capable of growth and survival
under competitive growing conditions.
Topographic map.—A map indicating surface
elevations and slopes.
Topography (lay-of-the-land).—The configura-
tion of the earth's surface, including the
shape and position of its natural and man-
made features.
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.
Toxic spoil.—See also Acid spoil; Spoil. In-
cludes acid spoil with pH below 4.0. Also
refers to spoil having amounts of minerals
such as aluminum, manganese, and iron
that adversely affect plant-growth.
Tracking.—The movement of bulldozers and
other cleated equipment up and down the
face of a slope for the purposes of stabiliza-
tion, compaction, erosion control, and vege-
tative establishment.
Transplant (forestry).—A seeding that has
been transplanted one or more times in the
nursery.
Unconsolidated (soil material). —Soil material
in a form of loose aggregation.
Vegetation.—General term including grasses,
legumes, shrubs, and trees, naturally occur-
ring and planted intentionally.
Vegetative buffer.—See Buffer strip.
Vegetative cover.—The entire vegetative can-
opy on an area.
Voids.—A general term for pore spaces or other
openings in rock. In addition to pore space,
the term includes vesicles, solution cavities,
or any openings, either primary or secondary.
Syn.: interstices.
Volunteer. —Springing up spontaneously or
without being planted; a volunteer plant.
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.
Water conservation.—The physical control,
protection, management, and use of water
resources in such a way as to maintain crop,
grazing, and forest lands, vegetal cover, wild-
life, and wildlife habitat for maximum sus-
tained benefits to people, agriculture, indus-
try, commerce, and other segments of the
national economy.
Water control (soil and water conservation).—
The physical control of water by such meas-
ures as conservation practices on the land,
channel improvements, and installation of
structures for water retardation and sedi-
ment detention. Does not refer to legal con-
trol or water rights as defined.
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.
Watersheds.—Total land area above a given
point on a stream or waterway that contrib-
utes runoff to that point.
Weathering.—Action of the weather elements
in altering the color, texture, composition, or
form of exposed objects.
Wind erosion.—The detachment and transpor-
tation of soil by wind.
Zeta potential.—A measure of the electrokinetic
charge (in millivolts) that surrounds sus-
pended particulate matter.
102
*U.S. GOVERNMENT PRINTING OFFICE: 1991.5its.187/ito5S8
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