nm3clol-public/Virginia_Tech/Virginia_Cooperative_Extension/2018-Powell River Refuse Reclamation Bulletin 460-131-1/README.md

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title: 2018-Powell River Refuse Reclamation Bulletin 460-131-1
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  - Virginia_Cooperative_Extension
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1

Publication 460-131

Introduction
Stabilization and reclamation of coal refuse disposal 
piles and fills are costly and challenging problems fac-
ing the Appalachian coal industry today. Coal refuse 
disposal areas are also known as “gob piles,” “slate 
dumps,” “waste piles,” and “refuge.” The exact acre-
age of coal refuse in the Appalachian coal fields is dif-
ficult to estimate, but active disposal facilities (figure 
1) cover thousands of acres, and abandoned refuse piles 
dot the landscape in almost every major watershed. We 
estimate that annual production of coal refuse exceeds 
10 million tons in Virginia alone. 

This publication reviews problems associated with 
stabilization and revegetation of coal refuse disposal 
areas and suggests strategies for their successful long-
term reclamation and closure. The primary focus is 
establishment of vegetation, but other refuse stabiliza-
tion issues are discussed. The reader is encouraged to 
consult the papers and reports cited in the references 
section for specific details and technical data. The regu-
latory framework discussed in this paper is specific to 
Virginia, but it is similar to that of other coal-mining 
states in the Appalachian coal region.

Modern coal-cleaning technologies have allowed coal 
preparation facilities to become quite efficient at remov-
ing sulfur compounds, waste rock, and low-grade coals 
from run-of-mine coal. Up to 50 percent of the raw, 
mined product may end up as refuse, particularly when 
the coal originates from longwall mining operations 

— thin, underground seams where some roof must be 
removed with the coal in order to assure adequate space 
for miners and equipment — or from seams that are 
high in partings, rock, and impurities. The refuse mate-
rials vary from coarse fragments removed by physical 
screening to very fine materials removed by flotation 
and density separation processes. 

Reclamation of Coal Refuse Disposal Areas
W. Lee Daniels, Professor, Crop and Soil Environmental Sciences, Virginia Tech

Barry Stewart, Associate Professor, Plant and Soil Sciences, Mississippi State University
C. E. Zipper, Extension Specialist, Crop and Soil Environmental Sciences, Virginia Tech

Figure 1. A typical coal refuse disposal area in Southwest 
Virginia. Coal refuse materials are transported to the fill 
by an elevated belt line and then compacted in place in 
a valley fill configuration. Note the steep slopes on the 
fill face and the fact that the lower cells on the face have 
been vegetated while the upper cells are still bare.

P o w e l l  R i v e R  P R o j e c t

Reclamation Guidelines foR suRface-mined land

www.ext.vt.edu
Produced by Virginia Cooperative Extension, Virginia Tech, 2018

Virginia Cooperative Extension programs and employment are open to all, regardless of age, color, disability, gender, gender identity, gender expression, national origin, political affiliation, race, religion, sexual orientation, genetic informa-
tion, veteran status, or any other basis protected by law. An equal opportunity/affirmative action employer. Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, 

and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg. 

VT/0218/460-131 (CSES-215P)

la Virginia Cooperative Extension

Virginia Tech «+

A.

Virginia State University

Publication 460-131

Zs Powe t River Prosect

RECLAMATION GUIDELINES FOR SuRFACE-Minep LanD

Reclamation of Coal Refuse Disposal Areas

W. Lee Daniels, Professor, Crop and Soil Environmental Sciences, Virginia Tech
Barry Stewart, Associate Professor, Plant and Soil Sciences, Mississippi State University
C.E. Zipper, Extension Specialist, Crop and Soil Environmental Sciences, Virginia Tech

Introduction

Stabilization and reclamation of coal refuse disposal
piles and fills are costly and challenging problems fac-
ing the Appalachian coal industry today. Coal refuse
disposal areas are also known as “gob piles,” “slate
dumps,” “waste piles,” and “refuge.” The exact acre-
age of coal refuse in the Appalachian coal fields is dif-
ficult to estimate, but active disposal facilities (figure
1) cover thousands of acres, and abandoned refuse piles
dot the landscape in almost every major watershed. We
estimate that annual production of coal refuse exceeds
10 million tons in Virginia alone.

This. put ion reviews problems associated with
stabilization and revegetation of coal refuse disposal
areas and suggests strategies for their successful long-
term reclamation and closure. The primary focus is
establishment of vegetation, but other refuse stabiliza-
tion issues are discussed. The reader is encouraged to
consult the papers and reports cited in the references
section for specific details and technical data, The regu-
latory framework discussed in this paper is specific to
Virginia, but it is similar to that of other coal-mining
states in the Appalachian coal region.

Modern coal-cleaning technologies have allowed coal
preparation facilities to become quite efficient at remov-
ing sulfur compounds, waste rock, and low-grade coals
from run-of-mine coal. Up to 50 percent of the raw,
ed product may end up as refuse, particularly when
the coal originates from longwall mining operations

Figure 1. A typical coal refuse disposal area in Southwest
Virginia. Coal refuse materials are transported to the fill
byan elevated belt line and then compacted in place in
a valley fill configuration. Note the steep slopes on the
fill face and the fact that the lower cells on the face have
been vegetated while the upper cells are still bare.

thin, underground seams where some roof must be
removed with the coal in order to assure adequate space
for miners and equipment — or from seams that are
high in partings, rock, and impurities. The refuse mate-
rials vary from coarse fragments removed by physical
screening to very fine materials removed by flotation
and density separation processes.

www.extvtedu
Produced by Virginia Cooperative Extension, Virginia Tech, 2018

SN nt Be al ae on OTS Er a

eer te a in an eee Ree rs





2

The potential hazards of improperly reclaimed refuse 
include contamination of surface and groundwater by 
acidic leachates and runoff, erosion and sedimentation 
into nearby water bodies, spontaneous combustion, and 
damage from landslides. While these problems were 
common on refuse piles constructed prior to the 1970s, 
modern regulations attempt to minimize the environ-
mental impact of coal refuse disposal. 

Several, if not all, of the problems associated with coal 
refuse piles can be reduced significantly with the main-
tenance of a viable plant cover. A vigorous plant com-
munity can reduce water and oxygen movement down 
into the fill, thereby limiting the production of acidic 
leachates while reducing sediment losses and stabiliz-
ing the fill surface. Establishment and maintenance of 
permanent vegetation on refuse, however, is compli-
cated by physical, mineralogical, and chemical factors. 

Regulatory Framework and 
Reclamation Strategies
Reclamation standards for refuse disposal in Virginia are 
set forth in the Permanent Regulatory Program of the Vir-
ginia Division of Mined Land Reclamation (VDMLR; 
see Virginia Department of Mines, Minerals and Energy, 
Virginia Administrative Code). The state regulations 
and performance standards are subject to oversight and 
review by the U.S. Office of Surface Mining Reclama-
tion and Enforcement and must meet the minimum stan-
dards set forth in the federal Surface Mining Control and 
Reclamation Act (SMCRA) of 1977. 

An important aspect of these regulations is the five-
year bond liability period. Before reclamation bond 
monies are completely released, refuse disposal areas 
must support self-sustaining vegetation for a minimum 
period of five years after closure. Leachate and runoff 
must meet water quality standards for this same period, 
and there must be evidence that water quality will not 
degrade over the long term. 

Refuse disposal areas are generally constructed as 
large valley fills, with surface water diverted around or 
through drains under the completed fill. These fills are 
commonly hundreds of acres in size and are perched in 
the headwaters of many watersheds. The refuse is com-
pacted into place, and the entire fill must meet rigorous 
geotechnical stability standards. Many refuse disposal 
areas are constructed using a “zoned disposal” concept, 
where refuse slurry generated in the fine-coal-cleaning 
circuit is impounded behind a compacted dam of coarse 

refuse. The face and sideslopes of the fills are generally 
constructed to a steep gradient to minimize the total 
disturbed area, and these steep slopes greatly com-
plicate reclamation. Most fills are designed for a life-
time of tens of years. Therefore, many active fills were 
designed before current regulations were in force. 

Once the fill is completed, regulations require that “the 
site shall be covered with a minimum of 4 feet of the best 
available nontoxic and noncombustible materials” unless 
a suitable alternative reclamation strategy is employed. 
Less than 4 feet of cover materials may be used if chemi-
cal and physical analyses indicate its properties are con-
ducive to establishing a permanent vegetative cover and 
the applicant can prove that the standards for revegeta-
tion success can be met. Thick topsoiling is quite costly 
and may be impractical in areas where native soils are 
shallow. Extensive topsoiling also creates the problem of 
reclaiming the borrow areas. 

Coal refuse disposal areas are required to meet the same 
standards for revegetation success following the five-
year bond liability period as surface-mined sites. Top-
soiling or covering with surface mine spoils (topsoil 
substitutes) may be the only option available on some 
sites due to toxic properties of the materials, but direct-
seeding appears to be a viable alternative for some 
refuse materials. Documented field trials have gener-
ally been required to evaluate the suitability of refuse 
materials as a plant-growth medium via direct-seeding 
because reliable laboratory testing methods that corre-
late with plant-growth response have not been avail-
able. It is our belief, however, that many coal refuse 
piles can be successfully direct-seeded by following the 
procedures outlined in this paper without long-term, 
dedicated on-site experimental trials. 

Coal Refuse Properties and 
Reclamation Success
The long-term stability of any reclaimed coal waste 
pile is largely dependent upon the ability of surface 
treatments (including soil cover) to establish a favor-
able plant-rooting environment. Failure to maintain 
long-term vegetation results in excessive erosion and 
gullying. Lack of a plant cover will also cause subsur-
face water contents and leachate production to increase 
due to lack of rain interception by the plant canopy 
and decreased plant transpiration. The key to develop-
ing successful long-term reclamation strategies is an 
understanding of the nature and variability of the coal 
refuse materials and how they will respond to various 

www.ext.vt.edu

The potential hazards of improperly reclaimed refuse

nclude contamination of surface and groundwater by
acidic leachates and runoff, erosion and sedimentation

nto nearby water bodies, spontaneous combustion, and
damage from landslides. While these problems were
common on refuse piles constructed prior to the 1970s,
modern regulations attempt to minimize the environ-
mental impact of coal refuse disposal.

Several, if not all, of the problems associated with coal
refuse piles can be reduced significantly with the main-
tenance of a viable plant cover. A vigorous plant com-
munity can reduce water and oxygen movement down
into the fill, thereby limiting the production of acidic
leachates while reducing sediment losses and stabiliz-
ing the fill surface. Establishment and maintenance of
permanent vegetation on refuse, however, is compli-
cated by physical, mineralogical, and chemical factors.

Regulatory Framework and

Reclamation Strategies

Reclamation standards for refuse disposal in Virginia are
set forth in the Permanent Regulatory Program of the Vir-
ginia Division of Mined Land Reclamation (VDMLR;
see Virginia Department of Mines, Minerals and Energy,
Virginia Administrative Code), The state regulations
and performance standards are subject to oversight and
review by the U.S. Office of Surface Mining Reclama-
tion and Enforcement and must meet the minimum stan-
dards set forth in the federal Surface Mining Control and
Reclamation Act (SMCRA) of 1977.

An important aspect of these regulations is the five-
year bond liability period. Before reclamation bond
monies are completely released, refuse disposal areas
must support self-sustaining vegetation for a minimum
period of five years after closure. Leachate and runoff
must meet water quality standards for this same period,
and there must be evidence that water quality will not
degrade over the long term.

Refuse disposal areas are generally constructed as
large valley fills, with surface water diverted around or
through drains under the completed fill. These fills are
commonly hundreds of acres in size and are perched in
the headwaters of many watersheds, The refuse is com-
pacted into place, and the entire fill must meet rigorous
geotechnical stability standards. Many refuse disposal
areas are constructed using a “zoned disposal” concept,
where refuse slurry generated in the fine-coal-cleaning
circuit is impounded behind a compacted dam of coarse

refuse, The face and sideslopes of the fills are generally
constructed to a steep gradient to e the total
disturbed area, and these steep slopes greatly com-
plicate reclamation, Most fills are designed for a
time of tens of years. Therefore, many active fills were
designed before current regulations were in force.

Once the fill is completed, regulations require that “the
site shall be covered with a minimum of 4 feet of the best
available nontoxic and noncombustible materials” unless
a suitable alternative reclamation strategy is employed.
Less than 4 feet of cover materials may be used if chemi:
cal and physical analyses indicate its properti
ducive to establishing a permanent vegetative cover and
the applicant can prove that the standards for revegeta-
tion success can be met. Thick topsoiling is quite costly
and may be impractical in areas where native soils are
shallow. Extensive topsoiling also creates the problem of
reclaiming the borrow areas.

are con-

Coal refuse disposal areas are required to meet the same
standards for revegetation success following the five
year bond liability period as surface-mined sites. Top-
soiling or covering with surface mine spoils (topsoil
substitutes) may be the only option available on some
sites due to toxic properties of the materials, but direct-
seeding appears to be a viable alternative for some
refuse materials, Documented field trials have gener-
ally been required to evaluate the suitability of refuse
materials as a plant-growth medium via direct-seeding
because reliable laboratory testing methods that corre-
late with plant-growth response have not been avail-
able. It is our belief, however, that many coal refuse
piles can be successfully direct-seeded by following the
procedures outlined in this paper without long-term,
dedicated on-site experimental trials.

Coal Refuse Properties and
Reclamation Success

The long-term stability of any reclaimed coal waste
pile is largely dependent upon the ability of surface
treatments (including soil cover) to establish a favor-
able plant-rooting environment. Failure to maintain
long-term vegetation results in excessive erosion and
gullying, Lack of a plant cover will also cause subsur-
face water contents and leachate production to increase
due to lack of rain interception by the plant canopy
and decreased plant transpiration, The key to develop-
ing successful long-term reclamation strategies is an
understanding of the nature and variability of the coal
refuse materials and how they will respond to various

Virginia Cooperative Extension | ywoxtvtedu
2




3

treatments over time. Long-term closure planning must 
also consider the potential of the pile to generate acid 
mine drainage (AMD). 

Many factors influence the reclamation potential of a 
given coal waste pile, including the geologic source of 
the refuse, the prep-plant processes, and local site con-
ditions. The following sections summarize properties 
and conditions known to influence refuse pile reclama-
tion and surrounding environmental quality and relate 
them to reclamation planning. 

Geologic Considerations and 
Prep-Plant Influences
The depositional environment of coal and its associated 
strata has a direct relationship to the properties of the 
coal seams, including coal bed thicknesses, sulfur and 
trace element content, and coal quality. Like natural 
soils, the primary components of coal refuse are miner-
als that contain silicon and aluminum. However, coal 
refuse differs from most natural soils in other ways. 
Depending on its pyrite content, the heavy metal con-
tent of coal refuse may be greater than is commonly 
encountered in natural soils. The total elemental content 
of 27 refuse materials sampled in southwestern Virginia 
in the late 1980s is similar to values for Appalachian 
coal refuse reported by other researchers (Rose, Robi, 
and Bland 1976; National Research Council 1979).

The correlation of paleoenvironment and coal proper-
ties has many important applications to both the mining 
and use of coal and to investigations into the nature of 
the wastes produced by mining. Although coal refuse 
shares many characteristics with the associated coal 
seams, coal refuse properties are also influenced by 
mining, coal cleaning, and geochemical weathering 
processes. 

Coal refuse is usually composed of rock fragments 
derived from interseam shale or siltstone partings and 
waste rock materials from above or below the seam. 
The refuse shares many properties with the associ-
ated coal seam. For example, some coal seams are 
inherently high in sulfur (e.g., the Pittsburgh seam of 
northern Appalachia), some are low in sulfur (the Poca-
hontas seam of the south-central Appalachian Basin), 
and some are variable. Southwest Virginia coal seams 
and associated strata are generally low in sulfur com-
pared to other Appalachian states. As a result, Virginia 
coal refuse tends to be comparatively low in sulfur and 
associated potential acidity (table 2). 

The processes utilized in the prep plant also influence 
the physical and chemical properties of the refuse 
stream. Some prep plants recombine coarse- and fine-
refuse fractions before disposal, while others dispose of 
these fractions separately or in zoned fills. Our work has 
focused on the reclamation of coarse refuse and recom-
bined refuse materials and not on slurry impoundments. 
The approach to direct reclamation of slurry materials 
would be similar to that described here, once the sur-
face has stabilized (Nawrot and Gray 2000). However, 
the most common practice is for slurry impoundments 
to be capped with coarse refuse and then reclaimed in 
similar fashion to the rest of the facility. 

The content and reactivity of pyritic sulfur exert a 
dominant influence on refuse chemical properties over 
time. The efficiency of a preparation plant at removing 
sulfur from the marketed coal and the degree to which 
the sulfide fragments are fractured and reduced in size 

Table 1. Descriptive statistics of the total 
elemental composition of 27 coal refuse 
materials sampled from southwestern Virginia 
by Stewart and Daniels (1992), compared to 
estimates for world soils. 

Element

SW Virginia Coal Refusea World Soilsb

Mean Median Range Median Range

mg/kg

SiO2 391 408 202-552 714 536-750

AlO2 128 133 62-196 155 22-656

FeO2 41 42 22-77 60 11-864

K2O 28.9 30 9.9-48.8 34 1-72

NaO 3.1 3 0.5-5.9 11 1-13

MgO 5.6 4.8 1.5-17.8 8 1-10

CaO 2.1 0.5 0.1-19.2 19 10-700

μg/kg

Cu 55 51.3 36.9-90.4 20 2-100

Zn 70.3 65.1 21.6-125.6 50 10-300

Ni 39.2 38.8 17.6-55.9 40 10-1,000
a Data from Stewart and Daniels (1992), Daniels and Stewart (2000).
b World soils’ estimates from Helmke (1999), converted to an oxide 
basis. 

www.ext.vt.edu

treatments over time. Long-term closure planning must
also consider the potential of the pile to generate acid
mine drainage (AMD).

Many factors influence the reclamation potential of a
given coal waste pile, including the geologic source of
the refuse, the prep-plant processes, and local site con-
ditions, The following sections summarize properties
and conditions known to influence refuse pile reclama-
tion and surrounding environmental quality and relate
them to reclamation planning,

Geologic Considerations and

Prep-Plant Influences

The depositional environment of coal and its associated
strata has a direct relationship to the properties of the
coal seams, including coal bed thicknesses, sulfur and
trace element content, and coal quality. Like natural
soils, the primary components of coal refuse are miner-
als that contain silicon and aluminum, However, coal
refuse differs from most natural soils in other ways.
Depending on its pyrite content, the heavy metal con-
tent of coal refuse may be greater than is commonly
encountered in natural soils. The total elemental content
of 27 refuse materials sampled in southwestern Virginia
in the late 1980s is similar to values for Appalachian
coal refuse reported by other researchers (Rose, Robi,
and Bland 1976; National Research Council 1979).

The correlation of paleoenvironment and coal proper-
ties has many important applications to both the mining
and use of coal and to investigations into the nature of
the wastes produced by mining. Although coal refuse
shares many characteristics with the associated coal
seams, coal refuse properties are also influenced by
mining, coal cleaning, and geochemical weathering
processes.

Coal refuse is usually composed of rock fragments
derived from interseam shale or siltstone partings and
waste rock materials from above or below the seam,
The refuse shares many properties with the associ-
ated coal seam. For example, some coal seams are
inherently high in sulfur (e.g., the Pittsburgh seam of
northern Appalachia), some are low in sulfur (the Poca-
hontas seam of the south-central Appalachian Basin),
and some are variable. Southwest Virginia coal seams
and associated strata are generally low in sulfur com-
pared to other Appalachian states. As a result, Virginia
coal refuse tends to be comparatively low in sulfur and
associated potential acidity (table 2)

The processes utilized in the prep plant also influence
the physical and chemical properties of the refuse
stream. Some prep plants recombine coarse- and fine-
refuse fractions before disposal, while others dispose of
these fractions separately or in zoned fills. Our work has
focused on the reclamation of coarse refuse and recom-
bined refuse materials and not on slurry impoundments.
The approach to direct reclamation of slurry materials
would be similar to that described here, once the sur-
face has stabilized (Nawrot and Gray 2000). However,
the most common practice is for slurry impoundments
to be capped with coarse refuse and then reclaimed in
similar fashion to the rest of the facility.

The content and reactivity of pyritic sulfur exert a
dominant influence on refuse chemical properties over
time. The efficiency of a preparation plant at removing
sulfur from the marketed coal and the degree to which
the sulfide fragments are fractured and reduced in size

Table 1. Descriptive statistics of the total
elemental composition of 27 coal refuse
materials sampled from southwestern Virginia
by Stewart and Daniels (1992), compared to
estimates for world soils.

SW Virginia Coal Refuse'| World Soils?

Element Mean Median Range Median Range

mg/kg
SiO, 391 408 202-552-714. 536-750
Alo, 128 133 62-196 155 22-656
FeO, 41 42-22-77 601-864
KO 289 30 99-488 34

NaO 3.1 3 0.5-5.9 u 1-13
MgO 56 48 15-178 8 1-10
CaO 2.1 0.5 0.1-19.2 19 10-700

nelkg

cu 55 S13 36.9-90.4 20 2-100
Zn 70.3. 65.1 21.6-125.6 5010-300
Ni 39.2 388 17.6559 40 10-1,000

“Data from Stewart and Daniels (1992), Daniels and Stewart (2000).
‘World soils’ estimates from Helmke (1999), converted to an oxide
basis,

Virginia Cooperative Extension | yweoxtvtedu
3




4

influence the reactivity and potential acidity of the final 
refuse product. Numerous reagents and additives such 
as anionic and cationic polymers, surfactants, oils, 
and strong bases are used in various separation and 
water treatment processes and also end up in the refuse 
stream to some extent. The influence of these additives 
on the revegetation potential of fresh refuse has not 
been studied. 

Variable Properties
A high degree of variability often exists in refuse mate-
rials within the same disposal area, because individual 
prep plants often process several coal seams. Each seam 
may exhibit different mineralogical, chemical, and phys-
ical properties. This variability makes the development 
of uniform reclamation strategies difficult. Additional 
variability is introduced through weathering. Because 
coal refuse materials are primarily fresh, unweathered 
geologic materials that have been subjected to severe 
treatment during processing, sharp changes in physical 

and chemical properties are common over short periods 
of time. The pH of fresh refuse can change dramati-
cally in a short period. We have observed the pH of a 
fresh, high-sulfur refuse change from 8.0 to 3.0 within 
a single month. 

Slope and Aspect Effects
Modern refuse piles are engineered to maximize vol-
ume capacity while minimizing their “footprint,” or the 
land area they occupy. Minimizing acreage necessitates 
the construction of steeply sloping embankments; these 
tend to be heavily compacted so as to maintain surface 
stability. Steep slopes complicate revegetation efforts in 
several ways. First, it can be very difficult to apply and 
incorporate soil amendments such as agricultural lime 
on steep slopes. Secondly, the steep slopes enhance 
rainfall runoff, which leads to droughty soil conditions. 
This soil water supply problem is further compounded 
by the compaction mandated to achieve slope stabil-
ity. Finally, the microclimate of steeply sloping areas 
will be strongly influenced by aspect. South-facing fill 
slopes will be extremely hot in the summer while north-
facing slopes are cooler and moister. Thus, regulatory 
and economic design pressures to limit the footprint of 
disturbance greatly complicate long-term stabilization 
and revegetation of refuse fills. 

Older piles, which predate the enactment of SMCRA 
and VDMLR regulations, often have steeply sloping 
sides that remain uncompacted. Hard rain tends to cause 
the surfaces of these abandoned piles to slide down-
ward, exposing fresh refuse. For successful revegeta-
tion, these slopes must be reconfigured to stable angles 
through regrading, and in some cases, with removal to 
an alternate location. No amount of vegetative cover 
will stabilize materials with fundamental slope insta-
bility problems. Fine-refuse particles washed from 
recently exposed surfaces present problems of acidi-
fication and sedimentation in nearby streams. This is 
predominantly a problem with abandoned piles, con-
structed prior to enactment of modern reclamation law, 
that are not under permit (figure 2).

Pyrite Oxidation and Potential Acidity
Many of the environmental problems associated with 
coal refuse occur as a result of pyrite oxidation and the 
production of acidity. Much of the total sulfur in refuse 
is present as pyrite (FeS2) and other sulfides that oxi-
dize to sulfuric acid in the presence of water and oxy-
gen. This highly acidified water is frequently less than 

Table 2. Median values for some physical and 
chemical properties of coarse coal refuse from 
Southwest Virginia; samples were taken from five 
active piles and 22 abandoned piles (Stewart and 
Daniels 1992). 
Parameter Median Value
Physical properties, whole refuse
% material > 2 mm diameter 60%
Fine-earth fraction: % material 
< 2 mm diameter

40%

Physical properties, fine-earth fraction
% sand-sized (2.000-0.050 mm) 60%
% silt-sized (0.050-0.002 mm) 22%
% clay-sized (< 0.002 mm) 15%
Soil textural class sandy loam
Chemical properties, whole refuse
Plant-available water 0.8%
pH 4.16
EC 0.04 S m-1

Cation exchange capacity 3.65 cmolc kg-1

Available phosphorus (P) 7.6 ppm
Potential acidity  
(acid-base accounting)

10.2 tons 
CaCO3/1,000 tons 

refuse
Potential acidity (H2O2) 27.8 tons 

CaCO3/1,000 tons 
refuse

www.ext.vt.edu

Table 2. Median values for some physical and
chemical properties of coarse coal refuse from
Southwest Virginia; samples were taken from five
active piles and 22 abandoned piles (Stewart and
Daniels 1992).

Parameter Median Value

Physical properties, whole refuse

‘% material > 2 mm diameter 60%
Fine-earth fraction: % material 40%
<2mm diameter

Physical properties, fine-earth fraction

% sand-sized (2.000-0.050 mm) 60%
4% silt-sized (0.050-0,002 mm) 2%

% clay-sized (< 0,002 mm) 15%

Soil textural class sandy loam

Chemical properties, whole refuse

Plant-available water 0.8%

pH 4.16

EC 0.04 S m"

Cation exchange capacity 3.65 cmol, kg"

Available phosphorus (P) 7.6 ppm

Potential acidity 10.2 tons

(acid-base accounting) CaCOY/1,000 tons
refuse

Potential acidity (Hy 27.8 tons

CaCO,/1,000 tons

refuse

influence the reactivity and potential acidity of the final
refuuse product. Numerous reagents and additives such
as anionic and cationic polymers, surfactants, oils,
and strong bases are used in various separation and
‘water treatment processes and also end up in the refuse
stream to some extent, The influence of these additives
on the revegetation potential of fresh refuse has not
been studied.

Variable Properties

Anigh degree of variability often exists in refuse mate-
rials within the same disposal area, because individual
prep plants often process several coal seams. Each seam
may exhibit different mineralogical, chemical, and phys-
ical properties. This variability makes the development
of uniform reclamation strategies difficult. Additional
variability is introduced through weathering. Because
coal refuse materials are primarily fresh, unweathered
geologic materials that have been subjected to severe
treatment during processing, sharp changes in physical

and chemical properties are common over short periods
of time. The pH of fresh refuse can change dramati.
cally in a short period. We have observed the pH of a
fresh, high-sulfur refuse change from 8.0 to 3.0 within
a single month.

Slope and Aspect Effects

Modern refuse piles are engineered to maximize vol-
ume capacity while minimizing their “footprint,” or the
land area they occupy. Minimizing acreage necessitates
the construction of steeply sloping embankments; these
tend to be heavily compacted so as to maintain surface
stability. Steep slopes complicate revegetation efforts in
several ways. First, it can be very difficult to apply and
incorporate soil amendments such as agricultural lime
on steep slopes. Secondly, the steep slopes enhance
rainfall runoff, which leads to droughty soil conditions.

This soil water supply problem is further compounded
by the compaction mandated to achieve slope stabil-
ity. Finally, the microclimate of steeply sloping areas
will be strongly influenced by aspect. South-facing fill
slopes will be extremely hot in the summer while north-
facing slopes are cooler and moister. Thus, regulatory
and economic design pressures to limit the footprint of
disturbance greatly complicate long-term stabilization
and revegetation of refuse fills.

Older piles, which predate the enactment of SMCRA
and VDMLR regulations, often have steeply sloping
sides that remain uncompacted. Hard rain tends to cause
the surfaces of these abandoned piles to slide down-
ward, exposing fresh refuse. For successful revegeta-
tion, these slopes must be reconfigured to stable angles
through regrading, and in some cases, with removal to
an alternate location. No amount of vegetative cover
will stabilize materials with fundamental slope insta-
bility problems. Fine-refuse particles washed from
recently exposed surfaces present problems of acidi
fication and sedimentation in nearby streams. This is
predominantly a problem with abandoned piles, con-
structed prior to enactment of modem reclamation law,
that are not under permit (figure 2)

Pyrite Oxidation and Potential Acidity

Many of the environmental problems associated with
coal refuse occur as a result of pyrite oxidation and the
production of acidity. Much of the total sulfur in refuse
is present as pyrite (FeS,) and other sulfides that oxi
dize to sulfuric acid in the presence of water and oxy-
gen. This highly acidified water is frequently less than

Virginia Cooperative Extension | ext vtedu
7




5

pH 3.0 and dissolves the mineral matrix around it as it 
leaches downward, becoming charged with aluminum, 
manganese, and other metals, cations, and salts. 

The pyrite reaction rate is dependent not only on the 
oxygen supply and microbial catalysis, but also on the 
size and morphology of pyrite particles. Two types of 
pyrite are commonly found in coal: Framboidal (fine) 
pyrite forms concurrently with the coal, while coarse-
grained pyrite is a secondary product of coal forma-
tion and is usually found in former plant structures and 
joints in the coal. Framboidal pyrite particles (2-15 
µ) have a high surface area and will oxidize rapidly. 
Coarse-grained pyrite is much less reactive. In some 

refuse materials, a large amount of the total sulfur is 
contained in relatively unreactive organic forms or as 
sulfate, one of the reaction products of the oxidation 
processes discussed above. Organic and sulfate forms 
of sulfur are not generally considered to be acid-pro-
ducing. Thus, the total sulfur content of refuse is not 
as reliable a predictor of acid-producing potential as 
pyritic sulfur content is. 

Freshly exposed pyritic refuse often has a near-neutral 
pH. After oxidation, pH values can drop dramatically, 
and many pyritic coal refuse materials have a very 
low (2.0 to 3.5) pH once they weather. After complete 
oxidation of sulfides and subsequent leaching of acid 
salts, the pH often rises into the low “4s” but is strongly 
buffered in that range by aluminum and other metals. 
The pH of a particular refuse material will depend not 
only on its pyrite content, but also on the length of 
exposure time and its acid-neutralizing capacity. Most 
coal refuse materials in the Appalachians contain an 
excess of oxidizable sulfur compared to neutralizing 
carbonates and are, therefore, net-acid-producing over 
time. The average fresh refuse material in Virginia 
requires 10 tons of calcium carbonate (CaCO3) per 
1,000 tons of raw refuse to neutralize the acidity pres-
ent, assuming complete reaction of pyrite and carbon-
ates via the regular acid-base accounting technique 
(table 2). The potential acidity of refuse materials in 
West Virginia and Kentucky is often much higher, 
sometimes exceeding 50 tons of lime requirement per 
1,000 tons. 

The rate of pyrite oxidation and acid production is gen-
erally highest in the oxygenated surface layer, which 
is also the zone utilized by plant roots. A rapid drop in 
pH releases plant-toxic concentrations of acid-soluble 
metal ions into soil solution and reduces the availabil-
ity of many plant nutrients. When the pH falls below 
4.5, root growth of many plant species ceases. Another 
problem caused by pyrite oxidation is the production of 
sulfate salts, which may accumulate to toxic levels in 
the root zone. These salts are generally water-soluble 
and accumulate on coal wastes during dry periods as 
water is lost by surface evaporation. The whitish sur-
face coating seen on refuse and coal piles during dry 
weather is evidence of this process (figure 3).

Heavy metals such as copper, nickel, and zinc are 
often associated with pyrite and other sulfide minerals. 
Elevated levels of heavy metals in soil solution can be 
toxic to plant roots and microbes and may pose a water 
quality hazard. 

Figure 2. A coal refuse pile located on the banks of 
Hurricane Creek in Russell County, Va., in a photograph 
from the early 1980s. The refuse pile, which extends 
well beyond the photographed area, was produced in 
the 1950s prior to SMCRA. Although the building in the 
foreground has been removed, the pile itself remains 
in place and retains a similar appearance today. This 
refuse pile has contributed literally hundreds of tons of 
sediments to Hurricane Creek, which drains into Dumps 
Creek and eventually into the Clinch River. 

www.ext.vt.edu

‘igure 2. A coal refuse pile located on the banks of
Hurricane Creek in Russell County, Va. in a photograph
from the early 1980s. The refuse pile, which extends
well beyond the photographed area, was produced in
the 1950s prior to SMCRA. Although the building in the
foreground has been removed, the pile itself remains

in place and retains a similar appearance today. This
refuse pile has contributed literally hundreds of tons of
sediments to Hurricane Creek, which drains into Dumps
Creek and eventually into the Clinch River.

pH 3.0 and dissolves the mineral matrix around it as it
leaches downward, becoming charged with aluminum,
manganese, and other metals, cations, and salts.

The pyrite reaction rate is dependent not only on the
oxygen supply and microbial catalysis, but also on the
size and morphology of pyrite particles. Two types of
pyrite are commonly found in coal: Framboidal (fine)
pyrite forms concurrently with the coal, while coarse-
grained pyrite is a secondary product of coal forma-
tion and is usually found in former plant structures and
joints in the coal. Framboidal pyrite particles (2-15
1) have a high surface area and will oxidize rapidly.
Coarse-grained pyrite is much less reactive. In some

refuse materials, a large amount of the total sulfur is
contained in relatively unreactive organic forms or as
sulfate, one of the reaction products of the oxidation
processes discussed above. Organic and sulfate forms
of sulfur are not generally considered to be acid-pro-
ducing. Thus, the total sulfur content of refuse is not
as reliable a predictor of acid-producing potential as
pyritic sulfur content

Freshly exposed pyritic refuse often has a near-neutral
pH. After oxidation, pH values can drop dramatically,
and many pyritic coal refuse materials have a very
low (2.0 to 3.5) pH once they weather. After complete
oxidation of sulfides and subsequent leaching of acid
salts, the pH often rises into the low “4s” butis strongly
buffered in that range by aluminum and other metals.
The pH of a particular refuse material will depend not
only on its pyrite content, but also on the length of
exposure time and its acid-neutralizing capacity. Most
coal refuse materials in the Appalachians contain an
excess of oxidizable sulfur compared to neutralizing
carbonates and are, therefore, net-acid-producing over
time. The average fresh refuse material in Virginia
requires 10 tons of calcium carbonate (CaCO,) per
1,000 tons of raw refuse to neutralize the acidity pres-
ent, assuming complete reaction of pyrite and carbon-
ates via the regular acid-base accounting technique
(table 2). The potential acidity of refuse materials in
West Virginia and Kentucky is often much higher,
sometimes exceeding 50 tons of lime requirement per
1,000 tons,

The rate of pyrite oxidation and acid production is gen-
erally highest in the oxygenated surface layer, which
is also the zone utilized by plant roots. A rapid drop in
pI releases plant-toxic concentrations of acid-soluble
metal ions into soil solution and reduces the availabil-
ity of many plant nutrients. When the pH falls below
4.5, root growth of many plant species ceases. Another
problem caused by pyrite oxidation is the production of
sulfate salts, which may accumulate to toxic levels in
the root zone. These salts are generally water-soluble
and accumulate on coal wastes during dry periods as
water is lost by surface evaporation. The whitish sur-
face coating seen on refuse and coal piles during dry
weather is evidence of this process (figure 3).

Heavy metals such as copper, nickel, and zine are
often associated with pyrite and other sulfide minerals.
Elevated levels of heavy metals in soil solution can be
toxic to plant roots and microbes and may pose a water
quality hazard.

Virginia Cooperative Extension | ywertvtiedu
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6

Acid Seepage and Leachate Production
While acid sulfate weathering processes drastically 
inhibit vegetation establishment, perhaps their great-
est environmental impact is through acid leachate pro-
duction. As drainage waters percolate through a refuse 
pile, leachates often become quite acidic and high in 
heavy metals. These leachates, collectively referred to 
as “acid mine drainage,” leave the pile as deep drain-
age waters, sideslope springs, or in surface runoff. If 
not properly curtailed or treated, AMD poses a serious, 
long-term water quality threat. Seeps of AMD on steep 
fill sideslopes also pose a major revegetation problem. 

Pyrite oxidation is catalyzed by acidophilic bacteria 
like Thiobacillus ferooxidans, which are ubiquitous in 
coal strata and are capable of functioning in very low 
oxygen (less than 1.0 percent partial pressure) envi-
ronments. Therefore, as long as acid water is allowed 
to percolate through a refuse fill, pyrite oxidation will 
occur deep within the pile, regardless of surface reveg-
etation and stabilization efforts. The net-leaching envi-
ronment of the Appalachians assures that acid mine 
drainage is inevitable for any coal refuse pile that con-
tains net-acid-forming materials. Due to the total mass 
of the pyrite in many refuse piles and the relatively slow 
rate of water movement through them, it is reasonable 
to expect that acid mine drainage will be emitted for 
decades, if not longer. 

Spontaneous Combustion
Many older refuse piles are high in coal fragments; 
often, such piles were constructed in loose, uncon-
solidated configurations that allow oxygen to interact 
easily with the refuse. Because pyrite oxidation is an 
exothermic (heat-producing) reaction, spontaneous 
combustion of older refuse piles was a common occur-
rence. Combustion of older piles has also occurred due 
to burning trash, arson, forest fires, and other factors. 
Burning refuse piles pose local air quality problems 
and are virtually impossible to revegetate unless the 
burning is stopped. 

Modern refuse piles are generally lower in coal than 
older piles due to improved coal-separation technolo-
gies and are compacted in place to limit air and water 
penetration. The thick topsoil requirement for refuse 
pile reclamation is also intended to further limit oxy-
gen movement into the fill, although our results indi-
cate that significant sulfur oxidation occurs in refuse, 
even under 4 feet of topsoil cover. Reports of combus-
tion of modern refuse fills are very rare. When they do 
occur, they are generally the result of arson or acciden-
tal ignition. 

Low Fertility
Because coal refuse is composed mainly of weathered 
rock and coal fragments, plant-available nitrogen (N) 
and phosphorous (P) are generally low. Due to their 
weatherable mineral content, however, refuse materials 
can be expected to supply adequate levels of calcium 
(Ca), magnesium (Mg), and potassium (K) to plants. In 
general, reclamation of coal refuse materials requires 
substantial fertilization, particularly with nitrogen and 
phosphorus. However, even large applications of nitro-
gen can easily leach out of the rooting zone within one 
year if not assimilated into plant tissue. The majority 
of plant-available nitrogen after the first year must be 
supplied by legumes and is held primarily in organic 
matter forms over time. Therefore, the establishment 
and maintenance of legumes over the first season after 
seeding is critical to long-term revegetation success. 

Soil phosphorus does not leach from the rooting zone 
in the same fashion as nitrogen; however, phospho-
rus is readily converted into soil mineral forms that 
are not available to plants. Soil phosphorus held in 
organic forms is protected against these losses, so the 
establishment and turnover of an organic matter pool 
in the reclaimed “refuse soil” is also critical for long-
term phosphorus fertility. Organic amendments such 

Figure 3. Sulfate salts weeping from an active coal refuse 
pile. These salts are the product of the acid sulfate 
weathering process within the fill and are transported to 
the fill surface by acidified seepage. When the seepage 
dries at the pile surface, the salts precipitate as seen here. 
The red colors are evidence of iron that is being released 
by pyrite oxidation and brought to the surface along with 
acidic seepage waters.

www.ext.vt.edu

Figure 3. Sulfate salts weeping from an active coal refuse
pile, These salts are the product of the acid sulfate
weathering process within the fill and are transported to
the fill surface by acidified seepage. When the seepage
dries at the pile surface, the salts precipitate as seen here.
The ted colors are evidence of iron that is being released
by pyrite oxidation and brought to the surface along with
acidic seepage waters.

Acid Seepage and Leachate Production

While acid sulfate weathering processes drastically
inhibit vegetation establishment, perhaps their great-
est environmental impact is through acid leachate pro-
duction. As drainage waters percolate through a refuse
pile, leachates often become quite acidic and high in
heavy metals. These leachates, collectively referred to
as “acid mine drainage,” leave the pile as deep drain-
age waters, sideslope springs, or in surface runoff. If
not properly curtailed or treated, AMD poses a serious,
long-term water quality threat. Seeps of AMD on steep
{ill sideslopes also pose a major revegetation problem,

Pyrite oxidation is catalyzed by acidophilic bacteria
like Thiobacillus ferooxidans, which are ubiquitous in
coal strata and are capable of functioning in very low
‘oxygen (less than 1.0 percent partial pressure) envi-
ronments. Therefore, as long as acid water is allowed
to percolate through a refuse fill, pyrite oxidation will
occur deep within the pile, regardless of surface reveg-
tation and stabilization efforts. The net-leaching envi-
ronment of the Appalachians assures that acid mine
drainage is inevitable for any coal refuse pile that con-
tains net-acid-forming materials. Due to the total mass
of the pyrite in many refuse piles and the relatively slow
rate of water movement through them, it is reasonable
to expect that acid mine drainage will be emitted for
decades, if not longer.

Spontaneous Combustion

Many older refuse piles are high in coal fragments;
often, such piles were constructed in loose, uncon-
solidated configurations that allow oxygen to interact
easily with the refuse. Because pyrite oxidation is an
exothermic (heat-producing) reaction, spontaneous
combustion of older refuse piles was a common occur-
rence, Combustion of older piles has also occurred due
to burning trash, arson, forest fires, and other factors.
Burning refuse piles pose local air quality problems
and are virtually impossible to revegetate unless the
burning is stopped,

Modem refuse piles are generally lower in coal than
older piles due to improved coal-separation technolo-
gies and are compacted in place to limit air and water
penetration. The thick topsoil requirement for refuse
pile reclamation is also intended to further limit o:
gen movement into the fill, although our results indi-
cate that significant sulfur oxidation occurs in refuse,
even under 4 feet of topsoil cover. Reports of combus
tion of modern refuse fills are very rare. When they do
occur, they are generally the result of arson or acciden-
tal ignition.

Low Fertility

Because coal refuse is composed mainly of weathered
rock and coal fragments, plant-available nitrogen (N)
and phosphorous (P) are generally low. Due to their
weatherable mineral content, however, refuse materials
can be expected to supply adequate levels of calcium
(Ca), magnesium (Mg), and potassium (K) to plants. In
general, reclamation of coal refuse materials requires
substantial fertilization, particularly with nitrogen and
phosphorus. However, even large applications of nitro-
gen can easily leach out of the rooting zone within one
year if not assimilated into plant tissue. The majority
of plant-available nitrogen after the first year must be
supplied by legumes and is held primarily in organic
matter forms over time. Therefore, the establishment
and maintenance of legumes over the first season after
seeding is critical to long-term revegetation success.

Soil phosphorus does not leach from the rooting zone
in the same fashion as nitrogen; however, phospho-
rus is readily converted into soil mineral forms that
are not available to plants. Soil phosphorus held in
organic forms is protected against these losses, so the
establishment and tumover of an organic matter pool
in the reclaimed “refuse soil” is also critical for long-
term phosphorus fertility. Organic amendments such

Virginia Cooperative Extension |r oxtvtedu
6




7

as biosolids (sewage sludge) or composts supply large 
amounts of nitrogen and phosphorus in addition to 
their beneficial effects on the soil physical environment 
and should be considered for use on refuse piles when 
available (figure 4). For additional discussion of nitro-
gen and phosphorus behavior in mine soils, see Virginia 
Cooperative Extension (VCE) publication 460-121. 

Moisture Retention, Rooting Depth, and 
Compaction
Inadequate plant-available moisture is a major problem 
with all mine spoils and refuse materials. The moisture-
holding properties of a given refuse are directly related 
to its particle size distribution. Coal refuse is usually 
coarse in texture with a very low water-holding capac-
ity (figure 5). Refuse materials in Virginia average 59 
percent rock fragments (more than 2 mm), depending 
on length of exposure to weathering (table 2). As the 
average refuse particle size increases, the material’s 
moisture retention capacity is reduced. The exclusion of 
fine refuse from a fill will further reduce water-holding 
capacity. For this reason, it is desirable to place com-
bined refuse (coarse plus fine) in the final revegetation 
surface if possible. 

Plant roots are able to extract nearly all available water 
that is retained in the rooting zone of refuse (usually the 
upper 24 inches) if potential acidity has been neutral-
ized. There are a number of ways to increase moisture 
retention in coal refuse. The addition of organic amend-
ments, heavy mulching, and the natural process of soil 
organic matter accumulation over time will all improve 

the water-supplying ability of coal refuse. We have 
frequently observed that the addition of only several 
inches of topsoil or similar finer spoil materials to an 
otherwise barren coal refuse material is all that is nec-
essary to promote plant growth in cases where potential 
acidity has been neutralized. This occurs because the 
cover material improves water retention and supply. 
In older piles where weathering has taken place, the 
upper surface may contain very fine particles similar in 
texture to silt or clay; such materials will have higher 
moisture retention than coarse, fresh refuse. When 
revegetating older piles where soil cover is expensive 
or limited, weathered surface materials should be seg-
regated prior to regrading and then reapplied to the pile 
as final cover. 

Virginia mining regulations require that all regulated 
structures be designed for stability. Regulations gov-
erning coal refuse disposal (Virginia Administrative 
Code 4VAC25-130-816.83: Coal mine waste; Refuse 
piles) do not explicitly require compaction, but they do 
state, “Regular inspections … shall also be conducted 
during placement and compaction of coal mine waste 
material.” Excessive compaction has been identified as 
a major factor limiting reclamation success throughout 
the United States and will cause similar problems in 
coal refuse materials by limiting the available root-
ing depth. Whenever possible (e.g., on near-level or 
mildly sloping surfaces where surface stability is not 
a major concern), the final lift or surface of the refuse 
pile should be left as loose as possible to enhance its 
potential to support plant growth. 

Figure 4. A vigorous and diverse stand of herbaceous 
perennial vegetation established on moderately acidic 
refuse in Southwest Virginia by direct-seeding. The refuse 
was limed, treated with biosolids, and mulched heavily 
with fiber mulch and straw. The seeding mix shown in 
table 3 was used on this site. This picture was taken four 
full growing seasons after seeding.

Figure 5. Comparison of plant-available, water-holding 
capacities (percent by weight) of a typical Appalachian 
soil (Muskingum sandy loam, A horizon) and coal refuse. 
Two refuse values are given: an average of 27 Virginia 
coal refuse piles sampled in 1986 and 1987, and a value 
representative of the low water-holding capacity of refuse 
that has been adjusted for coarse-fragment content 
(Stewart and Daniels 1992).

www.ext.vt.edu

as biosolids (sewage sludge) or composts supply large
amounts of nitrogen and phosphorus in addition to
their beneficial effects on the soil physical environment
and should be considered for use on refuse piles when
available (figure 4). For additional discussion of nitro-
gen and phosphorus behavior in mine soils, see Virginia
‘Cooperative Extension (VCE) publication 460-121

Figure 4. A vigorous and diverse stand of herbaceous
perennial vegetation established on moderately acidic
refuse in Southwest Virginia by direct-seeding, The refuse
was limed, treated with biosolids, and mulched heavily
with fiber mulch and straw. The seeding mix shown in
table 3 was used on this site. This picture was taken four
{full growing seasons after seeding.

Moisture Retention, Rooting Depth, and
Compaction

Inadequate plant-available moisture is a major problem
with all mine spoils and refuse materials. The moisture-
holding properties of a given refuse are directly related
to its particle size distribution. Coal refuse is usually
coarse in texture with a very low water-holding capac-
ity (figure 5). Refuse materials in Virginia average 59
percent rock fragments (more than 2 mm), depending
on length of exposure to weathering (table 2). As the
average refuse particle size increases, the material's
moisture retention capacity is reduced. The exclusion of
fine refuse from a fill will further reduce water-holding
capacity. For this reason, it is desirable to place com-
bined refuse (coarse plus fine) in the final revegetation
surface if possible.

Plant roots are able to extract nearly all available water
that is retained in the rooting zone of refuse (usually the
upper 24 inches) if potential acidity has been neutral-
ized, There are a number of ways to increase moisture
retention in coal refuse. The addition of organic amend-
ments, heavy mulching, and the natural process of soil
organic matter accumulation over time will all improve

Fd

=
i
8
e
§
2
3
4
2
2

2

MuskA — Reluse Avg, Refuse Low
Figure 5. Comparison of plant-available, water-holding
capacities (percent by weight) of a typical Appalachian
soil (Muskingum sandy loam, A horizon) and coal refuse.
‘Two refuse values are given: an average of 27 Virginia

coal refuse piles sampled in 1986 and 1987, and a value
representative of the low water-holding capacity of refuse
that has been adjusted for coarse-fragment content
(Stewart and Daniels 1992),

the water-supplying ability of coal refuse. We have
frequently observed that the addition of only several
inches of topsoil or similar finer spoil materials to an
otherwise barren coal refuse material is all that is nec-
essary to promote plant growth in cases where potential
acidity has been neutralized. This occurs because the
cover material improves water retention and supply.
In older piles where weathering has taken place, the
upper surface may contain very fine particles similar in
texture to silt or clay; such materials will have higher
moisture retention than coarse, fresh refuse, When
revegetating older piles where soil cover is expensive
or limited, weathered surface materials should be seg-
regated prior to regrading and then reapplied to the pile
as final cover.

Virginia mining regulations require that all regulated
structures be designed for stability. Regulations gov-
ering coal refuse disposal (Virginia Administrative
Code 4VAC25-130-816.83: Coal mine waste; Refuse
piles) do not explicitly require compaction, but they do
state, “Regular inspections ... shall also be conducted
during placement and compaction of coal mine waste
material.” Excessive compaction has been identified as
4 major factor limiting reclamation success throughout
the United States and will cause similar problems in
coal refuse materials by limiting the available root-
ing depth, Whenever possible (¢.g., on near-level or
mildly sloping surfaces where surface stability is not
a major concern), the final lift or surface of the refuse
pile should be left as loose as possible to enhance its
potential to support plant growth,

Virginia Cooperative Extension |r oxtvtedu
7




8

High Surface Temperature
Coal refuse varies in color from light gray to black. 
Thus, much of the incoming solar radiation is retained 
as heat. Under sunny skies, the surface temperatures on 
the refuse surface may exceed air temperature by 30°F 
or more, depending on cloud cover and slope aspect. 
Surface temperature may fluctuate widely during the 
course of a day. Early morning temperatures may 
be higher than air temperatures due to heat retention 
within the pile, and this is also true of evening tem-
peratures. On a warm cloudless day on a south-facing 
slope, the surface temperature may exceed 150°F. Sur-
face temperatures in this range are lethal to plants, and 
legume seedlings are susceptible to heat kill at much 
lower temperatures. 

Summary
The development of a successful coal refuse area recla-
mation strategy must take a number of factors and pro-
cesses into account. Most importantly, the surface of 
the refuse must be manipulated and treated to overcome 
soil water-holding, temperature, and acidity problems. 
The revegetation strategy must be capable of produc-
ing a plant community that can withstand a wide range 
of harsh soil and microclimatic conditions. Finally, the 
steeply sloping surfaces of most refuse piles greatly 
complicate revegetation. Each area of the coal refuse 
fill must be carefully assessed for the properties and 
problems discussed above, and the final reclamation 
approach must be tailored accordingly. 

Coal Refuse Reclamation Studies 
and Trials
Best results in reclamation of coal refuse piles have 
been achieved by incorporating lime and plant nutri-
ents into a suitable soil cover above the refuse. In some 
cases, this is not possible due to the lack of available 
soil cover materials or the expense of transporting soil. 
Vegetation can be established directly on some refuse 
materials after amendment with lime and fertilizers. 

The major question involved with direct-seeding strate-
gies is whether or not the surface will remain hospitable 
for plants over extended periods of time. The establish-
ment of a permanent legume component on refuse is 
particularly difficult. Improvement in vegetation estab-
lishment on bare refuse has been reported with high 
rates of organic amendments (composts or biosolids) 
in a number of states. Combinations of lime, mulching, 

heavy phosphorus, and biosolids treatments maintained 
vigorous vegetation for five full seasons in Southwest 
Virginia in Powell River Project trials on slightly acidic 
refuse materials (figure 6). Subsequent applications of 
these guidelines, conducted by mining firms working 
in cooperation with the authors, have demonstrated that 
these recommendations can be applied successfully at 
an operational scale.

Figure 6. The refuse revegetation guidelines in this 
publication were developed through methods that 
included plot-scale field trials, such as those shown in the 
mid-to-lower left of this photograph, and operational-
scale trials conducted by mining firms. 

How to Develop a Successful 
Refuse Reclamation Strategy
The successful long-term stabilization and reclamation 
of refuse piles is a difficult and complicated process. 
Reclamation strategies must be based on a thorough 
understanding of refuse and disposal site properties, 
how they will react to various treatments, and how the 
soil/plant system will change with time. Establishing a 
vigorous cover to stabilize the fill surface and reduce 
acid leachate production is critical. 

Moisture stress, induced by high coarse-fragment 
contents, salts, and high surface heat, is the primary 
growth-limiting factor in most fresh coal refuse. As the 
materials weather, acidity becomes a major problem in 
some refuse, but acidity can be controlled to a large 
extent by liming. Many coal refuse materials can be 
successfully direct-seeded once their potential acidity 
has been neutralized through appropriate liming prac-
tices (figure 7). 

Reagents and chemicals used in mineral processing 
may also limit plant growth in fresh wastes, but lit-
tle is known about their effects. Once the coal refuse 

www.ext.vt.edu

High Surface Temperature

Coal refuse varies in color from light gray to black.
‘Thus, much of the incoming solar radiation is retained
as heat, Under sunny skies, the surface temperatures on
the refuse surface may exceed air temperature by 30°F
or more, depending on cloud cover and slope aspect.
Surface temperature may fluctuate widely during the
course of a day. Early moming temperatures may
be higher than air temperatures due to heat retention
within the pile, and this is also true of evening tem-
peratures. On a warm cloudless day on a south-facing
slope, the surface temperature may exceed 150°F, Sur-
face temperatures in this range are lethal to plants, and
legume seedlings are susceptible to heat kill at much
lower temperatures,

Summary

The development of a successful coal refuse area recla-
mation strategy must take a number of factors and pro-
cesses into account, Most importantly, the surface of
the refuse must be manipulated and treated to overcome
soil water-holding, temperature, and acidity problems.
The revegetation strategy must be capable of produc-
ing a plant community that can withstand a wide range
of harsh soil and microclimatic conditions. Finally, the
steeply sloping surfaces of most refuse piles greatly
complicate revegetation. Each area of the coal refuse
fill must be carefully assessed for the properties and
problems discussed above, and the final reclamation
approach must be tailored accordingly.

Coal Refuse Reclamation Studies
and Trials

Best results in reclamation of coal refuse piles have
been achieved by incorporating lime and plant nutri-
cents into a suitable soil cover above the refuse. In some
cases, this is not possible due to the lack of available
soil cover materials or the expense of transporting soil.
Vegetation can be established directly on some refuse
materials after amendment with lime and fertilizers.

‘The major question involved with direct-seeding strate-
gies is whether or not the surface will remain hospitable
for plants over extended periods of time. The establish-
ment of a permanent legume component on refuse is
particularly difficult. Improvement in vegetation estab-
lishment on bare refuse has been reported with high
rates of organic amendments (composts or biosolids)
ina number of states. Combinations of lime, mulching,

heavy phosphorus, and biosolids treatments maintained
vigorous vegetation for five full seasons in Southwest
Virginia in Powell River Project trials on slightly acidic
refuse materials (figure 6). Subsequent applications of
these guidelines, conducted by mining firms working
in cooperation with the authors, have demonstrated that
these recommendations can be applied successfully at
an operational scale

Figure 6. The refuse revegetation guidelines in this
publication were developed through methods that
included plot-scale field trials, such as those shown in the
mid-to-lower left of this photograph, and operational-
scale trials conducted by mining firms.

How to Develop a Successful
Refuse Reclamation Strategy

The successful long-term stabilization and reclamation
of refuse piles is a difficult and complicated process.
Reclamation strategies must be based on a thorough
understanding of refuse and disposal site properties,
how they will react to various treatments, and how the
soil/plant system will change with time, Establishing a
vigorous cover to stabilize the fill surface and reduce
acid leachate production is critical.

Moisture stress, induced by high coarse-fragment
contents, salts, and high surface heat, is the primary
growth-limiting factor in most fresh coal refuse. As the
materials weather, acidity becomes a major problem in
some refuse, but acidity can be controlled to a large
extent by liming. Many coal refuse materials can be
successfully direct-seeded once their potential acidity
has been neutralized through appropriate liming prac-
tices (figure 7).

Reagents and chemicals used in mineral processing
may also limit plant growth in fresh wastes, but lit-
tle is known about their effects. Once the coal refuse

Virginia Cooperative Extension | ywoxtvtedu
8




9

weathers and leaches for several years and its physical 
and chemical properties stabilize, it becomes easier to 
utilize as a plant-growth medium. Many of the older 
abandoned piles in the Appalachians are invaded by 
native pioneer vegetation after this stabilization occurs. 
Care should be taken not to disturb this fragile surface 
zone on older piles during reclamation, if possible.

The use of a reduced thickness of soil cover (less than 
4 feet) to reclaim coal refuse has been successful in 
several experiments in Virginia and other states. Even 
thin (less than 1 foot) layers can provide enough water-
holding capacity and suitable rooting environment for 
establishment of both grasses and legumes on moder-
ately acidic wastes. Thicker covers may be necessary 
for long-term legume vigor on highly acidic refuse. 
The use of lime at the refuse/soil contact is essential 
when thin topsoil covers are employed; lime applica-
tion rates should be based on the potential acidity of the 
underlying material. Where high surface temperature 
and low water supply are major problems, topsoiling 
also appears to be the best alternative for establishing 
a permanent vegetative cover. Direct-seeding appears 
feasible for refuse with low-to-moderate levels of acid-
ity (figure 8), particularly when heavy agricultural lime, 
mulch, and other organic treatments, like composts or 
biosolids, are employed. Topsoiling with liming is the 
best alternative for highly acidic materials. 

Revegetation strategies should establish a quick annual 
cover to rapidly provide shade and natural mulch for 
perennials. Any plant materials used on coal refuse must 

be capable of withstanding extreme short- and long-term 
changes in soil and site conditions. The importance of 
overcoming the heat- and water-holding limitations of 
bare refuse cannot be overemphasized. The combina-
tion of liming, fertilization, surface treatments, and seed-
ing mix must be designed to rapidly establish an annual 
cover that will shade the surface and thereby improve 
soil moisture and temperature conditions. 

The initial cover crop also takes up and holds essen-
tial plant nutrients against leaching and runoff and then 
returns these nutrients to the soil as it decomposes. The 
permanent perennial species then germinate and estab-
lish in the favorable microclimate provided by the cover 
crop. Once the perennial species are well-established 
(usually by the second year) and plant/soil nutrient 
cycles have become established, the chances for long-
term reclamation success (and bond release) are greatly 
improved. Over the years, we have observed many 
vigorous stands of annual cover crops on direct-seeded 
coal refuse materials. However, diverse self-sustaining 
stands of perennial grasses and legumes after multiple 
seasons are much more difficult to achieve. 

Guidelines for Refuse Revegetation 
in Southwest Virginia
The guidelines that follow represent our best recom-
mendations for the stabilization and revegetation of 
refuse piles in Southwest Virginia. They have been pro-
vided to VDMLR for consideration and have been used 
successfully by a number of mining firms. It is impor-
tant that these guidelines be used in consultation with 

Figure 7. Agricultural limestone being applied and 
tracked into a coal refuse fill face. Working lime and other 
amendments on the steeper slopes that dominate most 
refuse piles can be challenging. For extremely acidic 
refuse materials, several applications of lime split several 
months apart may be necessary. It is difficult to spread 
and incorporate more than 25 tons of lime per acre in one 
application, even on flat sites.

Figure 8. A well-developed grass-rooting system that 
grew in limed and fertilized coal refuse. Research and 
experience have demonstrated that many coal refuse 
materials will respond to lime, fertilizer, and organic 
amendments and can support vigorous plant growth with 
little or no soil cover.

www.ext.vt.edu

Figure 7. Agricultural limestone being applied and
tracked into a coal refuse fil face. Working lime and other
amendments on the steeper slopes that dominate most,
refuse piles can be challenging, For extremely acidic
refuse materials, several applications of lime split several
months apart may be necessary. Itis difficult to spread
and incorporate more than 25 tons of lime per acre in one
application, even on flat sites.

weathers and leaches for several years and its physical
and chemical properties stabilize, it becomes easier to
utilize as a plant-growth medium. Many of the older
abandoned piles in the Appalachians are invaded by
native pioneer vegetation after this stabilization occurs.
Care should be taken not to disturb this fragile surface
zone on older piles during reclamation, if possible.

The use of a reduced thickness of soil cover (less than
4 feet) to reclaim coal refuse has been successful in
several experiments in Virginia and other states. Even
thin (less than I foot) layers can provide enough water-
holding capacity and suitable rooting environment for
establishment of both grasses and legumes on moder-
ately acidic wastes. Thicker covers may be necessary
for long-term legume vigor on highly acidic refuse.
The use of lime at the refuse/soil contact is essential
when thin topsoil covers are employed; lime applica-
tion rates should be based on the potential acidity of the
underlying material, Where high surface temperature
and low water supply are major problems, topsoiling
also appears to be the best alternative for establishing
‘a permanent vegetative cover. Direct-seeding appears
feasible for refuse with low-to-moderate levels of ac
ity (figure 8), particularly when heavy agricultural lime,
mulch, and other organic treatments, like composts or
biosolids, are employed. Topsoiling with liming is the
best alternative for highly acidic materials.

Revegetation strategies should establish a quick annual
cover to rapidly provide shade and natural mulch for
perennials. Any plant materials used on coal refuse must

Figure 8. A well-developed grass-rooting system that
grew in limed and fertilized coal refuse. Research and
experience have demonstrated that many coal refuse
‘materials will respond to lime, fertilizer, and organic
amendments and can support vigorous plant growth with
little or no soil cover.

be capable of withstanding extreme short- and long-term
changes in soil and site conditions. The importance of
overcoming the heat- and water-holding limitations of
bare refuse cannot be overemphasized. The combina-
tion of liming, fertilization, surface treatments, and seed-
ing mix must be designed to rapidly establish an annual
cover that will shade the surface and thereby improve
soil moisture and temperature conditions

The initial cover crop also takes up and holds essen-
tial plant nutrients against leaching and runoff and then
returns these nutrients to the soil as it decomposes. The
permanent perennial species then germinate and estab-
lish in the favorable microclimate provided by the cover
crop. Once the perennial species are well-established
(usually by the second year) and plant/soil nutrient
cycles have become established, the chances for long-
term reclamation suecess (and bond release) are greatly
improved. Over the years, we have observed many
vigorous stands of annual cover crops on direct-seeded
coal refuse materials. However, diverse self-sustaining
stands of perennial grasses and legumes after multiple
seasons are much more difficult to achieve.

Guidelines for Refuse Revegetation
in Southwest Virg

The guidelines that follow represent our best recom-
mendations for the stabilization and revegetation of
refuse piles in Southwest Virginia, They have been pro-
vided to VDMLR for consideration and have been used
successfully by a number of mining firms. It is impor-
tant that these guidelines be used in consultation with

Virginia Cooperative Extension | ywrxtvtedu
9




10

regulatory authorities; use of these guidelines without 
regulatory agency concurrence may lead to permit vio-
lation, particularly with regard to topsoiling or fertilizer 
augmentation requirements. These guidelines are based 
upon Powell River Project cooperative research work 
at multiple sites since 1983 and our interpretations of 
relevant literature. 

Refuse Characterization
Our studies indicate that many refuse materials can be 
direct-seeded or successfully reclaimed with reduced 
topsoil depth if and only if their physical and chemical 
properties are well-understood. The two most impor-
tant properties are water-holding capacity and potential 
acidity. Therefore, in order to use our classification sys-
tem (table 3), data on these parameters and how they 
vary across the reclamation surface must be obtained. 

Particle-size distribution should be determined by sieve 
analysis. Any refuse that is less than 20 percent fines 
(less than 2 mm) will be difficult to reclaim regardless 

of acidity levels and should be topsoiled. It is pos-
sible to increase the water-holding capacity of coarse 
refuse with additions of organic amendments and fine-
textured soils, as discussed later. Compaction is also a 
major factor in limiting water-holding in refuse materi-
als. Therefore, for direct-seeding options, the surface 
18 inches of refuse (or deeper) should be left uncom-
pacted or should be ripped before seeding. 

Potential acidity should be determined by a qualified 
laboratory using either the conventional acid-base 
accounting (ABA) method or the hydrogen peroxide 
oxidation technique. These two techniques give some-
what different estimates of the liming requirement for 
refuse materials (table 2); the peroxide oxidation tech-
nique is more conservative. Potential acidity or acid-
base accounting results are typically reported in net 
tons of lime required per 1,000 tons of spoil or refuse 
tested. Given that an acre of refuse to a depth of 6 
inches weighs approximately 1,000 tons, these figures 
equate to a field liming estimate in tons per acre. Sim-
ple measurements of pH are not valid for estimating 

Table 3. Recommended guidelines for refuse classification and revegetationa.

Potential Acidity by 
Acid-Base  
Accounting (ABA) Lime Recommendation Amendments and Seeding Strategies

< 10 tons/acre net acid,  
> 20% finesb

Lime to ABA need Direct-seed with heavy phosphorus, straw mulch, and 
organic amendments if possiblec. Use refuse seed mixture 
(table 4).

10-25 T/Ac net acid, 
> 20% finesb

Lime to ABA, split if 
necessary

Direct-seed with heavy phosphorus, straw mulch, and 
organic amendment (required)c. Use refuse seed mixture 
(table 4).

25-50 T/Ac net acid Add lime (ABA need) at 
refuse-soil contact

Topsoil cover with 6-18 inches of final depth. Use con-
ventional lime, fertilizer, and seed.

25-50 T/Ac net acidd Without lime at soil contact Topsoil cover with 24 inches or more final depth. Use 
conventional lime, fertilizer, and seed.

> 50 T/Ac net acid Add lime (ABA need) at 
refuse-soil contact

18-24 inches of final topsoil depth. Use conventional 
lime, fertilizer, and seed.

a These recommendations do not take sideslope seeps and springs into account. Such seeps are usually acidic; affected areas will need to 
be spot treated.

b Refuse materials with less than 20 percent particles of less than 2 mm (less than 20 percent fines) should be topsoiled. 
c Organic amendment consisting of stabilized sewage sludge, papermill sludge, composted wood chips, or similar material with a carbon-
to-nitrogen ratio less than 30, at a rate of at least 35 dry tons per acre, incorporated with a chisel plow. 

d On flat and gently sloping surfaces, lime and organic amendments may be applied in several treatments. Splitting lime applications so as 
to allow it to react with the acidic refuse prior to seed application may allow direct-seeding on materials of up to 50 tons per acre net ABA 
acidity. This can occur only on near-level to moderately sloped areas. 

www.ext.vt.edu

regulatory authorities; use of these guidelines without
regulatory agency concurrence may lead to permit vi
lation, particularly with regard to topsoiling or fertilizer
augmentation requirements. These guidelines are based
upon Powell River Project cooperative research work
at multiple sites since 1983 and our interpretations of
relevant literature.

Refuse Characterization

Our studies indicate that many refuse materials can be
direct-seeded or successfully reclaimed with reduced
topsoil depth if and only if their physical and chemical
properties are well-understood. The two most impor-
tant properties are water-holding capacity and potential
acidity. Therefore, in order to use our classification sys-
tem (table 3), data on these parameters and how they
vary across the reclamation surface must be obtained

Particle-size distribution should be determined by sieve
analysis. Any refuse that is less than 20 percent fines
(less than 2 mm) will be difficult to reclaim regardless

of acidity levels and should be topsoiled. It is pos-
sible to increase the water-holding capacity of coarse
refuse with additions of organic amendments and fine-
textured soils, as discussed later. Compaction is also a
major factor in limiting water-holding in refuse materi-
als. Therefore, for direct-seeding options, the surface
18 inches of refuse (or deeper) should be left uncom-
pacted or should be ripped before seeding.

Potential acidity should be determined by a qualified
laboratory using either the conventional acid-base
accounting (ABA) method or the hydrogen peroxide
oxidation technique. These two techniques give some-
what different estimates of the liming requirement for
refuse materials (table 2); the peroxide oxidation tech-
nique is more conservative, Potential acidity or acid-
base accounting results are typically reported in net
tons of lime required per 1,000 tons of spoil or refuse
tested. Given that an acre of refuse to a depth of 6
inches weighs approximately 1,000 tons, these figures
equate to a field liming estimate in tons per acre.
ple measurements of pH are not valid for estimating

Table 3. Recommended guidelines for refuse classification and revegetation’.

Potential Acidity by
Acid-Base

Accounting (ABA) Lime Recommendation

Amendments and Seeding Strategies

< 10 tons/acre net acid, Lime to ABA need

> 20% fines?

10-25 T/Ac net acid,
> 20% fines?

Lime to ABA, spl
necessary

25-50 T/Ac net acid Add lime (ABA need) at

refuuse-soil contact

25-50 T/Ac net acid’ Without lime at soil contact,

> 50 T/Ac net acid Add lime (ABA need) at

refuse-soil contact

Direct-seed with heavy phosphorus, straw mulch, and
organic amendments if possible*. Use refuse seed mixture
(table 4).

Direct-seed with heavy phosphorus, straw mulch, and
organic amendment (required). Use refuse seed mixture
(table 4).

Topsoil cover with 6-18 inches of final depth. Use con-
ventional lime, fertilizer, and seed,

Topsoil cover with 24 inches or more final depth. Use
conventional lime, fertilizer, and seed,

18-24 inches of final topsoil depth. Use conventional
lime, fertilizer, and seed.

“These recommendations do not take sideslope seeps and springs into account. Such seeps are usually acidic; affected areas will need to

be spot treated.

Refuse materials with less than 20 percent particles of less than 2 mm (less than 20 percent fines) should be topsoiled,

“Organic amendment con

sting of stabilized sewage sludge, papermill sludge, composted wood chips, or similar material with a carbon-

to-nitrogen ratio less than 30, ata rate of at least 35 dry tons per acre, incorporated with a chisel plow.

“On flat and gently sloping surfaces,

me and organic amendments may be applied in several treatments. Splitting lime applications so as

toallow itto react with the acidie refuse prior to seed application may allow direct-seeding on materials of up to 50 tons per aere net ABA
acidity. This can occur only on near-level to moderately sloped areas.

Virginia Cooperative Extension |r oxtvtedu
10





11

refuse potential acidity because they do not account for 
unoxidized pyritic sulfur and/or the native lime content 
in the sample. The chemical reactions in the weathering 
refuse will cause the pH to change with time. 

The ABA lime requirements should be considered as 
a bare-minimum lime application; additional quantities 
may be applied to help ensure success. Many experts 
in the field of acid mine drainage control advocate the 
use of several times the amount of lime prescribed by 
the ABA technique to ensure that the treated zone of 
acid-forming material is permanently stabilized. Stud-
ies have shown that in some cases, the rate of pyrite 
oxidation is so fast and the levels of iron plus acidity 
generated in solution are so high that a large excess of 
reactive lime is necessary to prevent the alkaline side of 
the balance from being overwhelmed. 

Site Preparation
The preparation of a refuse disposal area for hydro-
seeding should begin well in advance of actual seed-
ing. Grading plans should minimize steep slopes where 
possible, provide equipment access for revegetation 
efforts, and reduce potential washes or rills from devel-
oping. The final lift of 2 to 3 feet of material should be 
left uncompacted or loosened with a ripper prior to the 
final grade. 

Where possible, it is advisable to allow fresh refuse to 
lie exposed for a period of six months or more before 
seeding. During this time, refuse samples representative 
of areas to be seeded should be collected and analyzed 
for potential acidity, as discussed earlier. Depending on 
this analysis, agricultural lime or other suitable liming 
materials should be applied and incorporated two to 
three months before planting. It is possible to reduce 
the potential acidity of highly acidic materials (as dis-
cussed in table 3) by repeated additions of lime over an 
extended period. Should this method be used, it is rec-
ommended that no more than 25 tons per acre of lime 
be applied at any one time. Single applications using 
higher rates have been shown to suffer from iron coat-
ings around larger-sized lime particles, rendering the 
lime ineffective unless the lime is thoroughly incorpo-
rated to a depth of 6 inches or more. Similar problems 
have been noted when coarse-textured liming materials 
have been utilized. 

Sloping areas are of particular concern in site prepara-
tion. Often, lateral water flow through a pile will result 
in an acid seep or “hot spot” along the slope. These areas 
often appear chalky white during dry weather and may 

exhibit a pH less than 3.0. These hot spots should be 
pinpointed and treated heavily with lime where possi-
ble to prevent future problems in plant establishment. 

Immediately prior to seeding, sloping areas should be 
prepared. The conventional approach is to “track” the 
slope with a dozer or other suitable equipment. If the 
site is tracked, that operation should be done in a man-
ner that leaves narrow track depressions across the face 
of the slope. In practice, these tracks retain water, seed, 
and mulch during rains and are usually the first areas 
to show plant growth. However, a large body of reveg-
etation literature clearly indicates that rough-graded 
slopes are much superior to tracked slopes for the pre-
vention of short-term runoff and for the establishment 
of vegetation. This is particularly true of sites where 
forest establishment is required (VCE publication 
460-123). Tracked slopes are also more compact than 
rough-graded slopes. In situations where surface sta-
bility is not a major concern, we strongly recommend 
only rough grading be applied to coal refuse disposal 
surfaces. 

Fertilization
Because of the inherently low fertility of refuse, veg-
etation establishment requires the addition of nitro-
gen, phosphorus, and potassium fertilizers. Field trials 
and laboratory analyses have pinpointed phosphorus 
as being the most limiting nutrient to plant growth on 
these sites. If topsoil or a topsoil substitute material is 
to be used, a representative sample should be submit-
ted to the Virginia Tech Soil Testing Laboratory (or a 
comparable commercial facility) for analysis. Please 
see VCE publication 460-121 for a discussion of fertil-
izer interpretations for mine soils. 

As a base rate of fertilizer for direct-seeding, 100 pounds 
per acre of nitrogen, 350 pounds per acre of phosphorus 
(as P2O5), and 100 pounds per acre of potassium (as 
K2O) are recommended. To attain this high phosphorus 
level, it may be necessary to supplement conventional 
fertilizers (e.g., 10-20-10) with a high-phosphorus fer-
tilizer like superphosphate. These rates are suggested 
when the seed mixture to be used contains legumes 
(clovers, trefoil, etc.) and they assume adequate estab-
lishment of legumes for continuing nitrogen availabil-
ity in succeeding years, as discussed earlier. 

When legumes are seeded, the appropriate inoculant 
should be added at the time of seeding (VCE publica-
tion 460-122). Care should be taken to keep the pH of 
the hydroseeder slurry buffered above 4.0 with lime. 

www.ext.vt.edu

refuse potential acidity because they do not account for
unoxidized pyritic sulfur and/or the native lime content
in the sample. The chemical reactions in the weathering
refuse will cause the pH to change with time.

The ABA lime requirements should be considered as
a bare-minimum lime application; additional quantities
may be applied to help ensure success. Many experts
in the field of acid mine drainage control advocate the
use of several times the amount of lime prescribed by
the ABA technique to ensure that the treated zone of
acid-forming material is permanently stabilized. Stud-
ies have shown that in some cases, the rate of pyrite
oxidation is so fast and the levels of iron plus acidity
generated in solution are so high that a large excess of,
reactive lime is necessary to prevent the alkaline side of
the balance from being overwhelmed.

Site Preparation

‘The preparation of a refuse disposal area for hydro-
seeding should begin well in advance of actual seed-
ing. Grading plans should minimize steep slopes where
possible, provide equipment access for revegetation
efforts, and reduce potential washes or rills from devel-
oping. The final lift of 2 to 3 feet of material should be
left uncompacted or loosened with a ripper prior to the
final grade.

Where possible, it is advisable to allow fresh refuse to
lie exposed for a period of six months or more before
seeding. During this time, refuse samples representative
of areas to be seeded should be collected and analyzed
for potential acidity, as discussed earlier, Depending on
this analysis, agricultural lime or other suitable liming
materials should be applied and incorporated two to
three months before planting, It is possible to reduce
the potential acidity of highly acidic materials (as dis-
cussed in table 3) by repeated additions of lime over an
extended period, Should this method be used, itis ree-
‘ommended that no more than 25 tons per acre of lime
be applied at any one time. Single applications using
higher rates have been shown to suffer from iron coat-
ings around larger-sized lime particles, rendering the
lime ineffective unless the lime is thoroughly incorpo-
rated to a depth of 6 inches or more. Similar problems
have been noted when coarse-textured liming materials
have been utilized.

Sloping areas are of particular concer in site prepara-
tion, Often, lateral water flow through a pile will result
in an acid seep or “hot spot” along the slope. These areas
often appear chalky white during dry weather and may

exhibit a pH less than 3.0, These hot spots should be
pinpointed and treated heavily with lime where pos
ble to prevent future problems in plant establishment.

Immediately prior to seeding, sloping areas should be
prepared. The conventional approach is to “track” the
slope with a dozer or other suitable equipment. If the
site is tracked, that operation should be done in a man-
ner that leaves narrow track depressions across the face
of the slope. In practice, these tracks retain water, seed,
and mulch during rains and are usually the first areas
to show plant growth. However, a large body of reveg-
etation literature clearly indicates that rough-graded
slopes are much superior to tracked slopes for the pre-
vention of short-term runoff and for the establishment
of vegetation. This is particularly true of sites where
forest establishment is required (VCE publication
460-123). Tracked slopes are also more compact than
rough-graded slopes. In situations where surface sta-
bility is not a major concern, we strongly recommend
only rough grading be applied to coal refuse disposal
surfaces.

Fertilization

Because of the inherently low fertility of refuse, veg-
etation establishment requires the addition of nitro-
gen, phosphorus, and potassium fertilizers. Field trials
and laboratory analyses have pinpointed phosphorus
as being the most limiting nutrient to plant growth on
these sites. IF topsoil or a topsoil substitute material is
to be used, a representative sample should be submit-
ted to the Virginia Tech Soil Testing Laboratory (or a
comparable commercial facility) for analysis. Please
see VCE publication 460-121 for a discussion of fertil-
izer interpretations for mine soils.

Asabase rate of fertilizer for direct-seeding, 100 pounds
per acre of nitrogen, 350 pounds per acre of phosphorus
(as P,O,), and 100 pounds per acre of potassium (as
K,0) are recommended. To attain this high phosphorus
level, it may be necessary to supplement conventional
fertilizers (e.g., 10-20-10) with a high-phosphorus fer-
tilizer like superphosphate. These rates are suggested
when the seed mixture to be used contains legumes
(clovers, trefoil, etc.) and they assume adequate estab-
lishment of legumes for continuing nitrogen availabil-
ity in succeeding years, as discussed earlier.

When legumes are seeded, the appropriate inoculant
should be added at the time of seeding (VCE publica-
tion 460-122). Care should be taken to keep the pH of
the hydroseeder slurry buffered above 4.0 with lime,

Virginia Cooperative Extension |r oxtvtedu
ll




12

The inoculant should be added to the hydroseeder tank 
immediately before seeding because the inoculant bac-
teria will perish if left in the high-salt environment of 
the hydroseeder slurry for more than a few minutes. If 
only grasses are to be used, the nitrogen rate should be 
adjusted upward to 150 pounds per acre, but the grasses 
will need additional nitrogen fertilizer in successive 
years in the absence of legumes. 

Seeding Rates and Species Mixtures
Selection of species suitable for planting on refuse is 
complicated by the variability of the material. There-
fore, it is imperative to use species that will tolerate 
a wide range of pH, moisture, and temperature condi-
tions. Consideration should also be given to the time 
of year when seed is applied and to the overall goal of 
establishing a diverse and permanent vegetative cover. 
These criteria cannot be met by use of a single spe-
cies mixture on all sites or under all conditions. Pow-
ell River Project direct-seeding field trials, which were 
established using the above criteria, have been suc-
cessful for five growing seasons and beyond on certain 
refuse materials. 

Species mixtures and seeding rates detailed in table 4 
appear to be suitable for direct-seeding of refuse and for 
use with topsoil covers. These recommendations were 
based on the conditions at our various research sites; 
the addition or deletion of species should be consid-
ered, depending on your local site conditions and seed 
availability. Each mixture contains species adapted to a 
variety of site conditions that are intended to overcome 
local minesoil variability problems and make the mixes 
usable on a variety of sites. 

Spring seeding should occur after March 15 and before 
May 15 for optimal results (table 5); fall seeding is rec-
ommended between September 15 and November 15. 
Environmental conditions during the summer and win-
ter are generally unfavorable for successful establish-
ment of mixed perennial vegetation, and annual covers 
should only be seeded during these periods. 

Commercially available wood fiber or paper mulches 
at conventional application rates perform satisfactorily 
for their intended use — the establishment of grasses 
on topsoil. However, they are inadequate under the 
extreme environmental stresses on refuse piles. Our 
recommendation is that paper mulches be used at higher 
rates (more than 2,000 pounds per acre) in the hydro-
seeder tank mix or in conjunction with straw mulch on 
refuse. Field trials indicate that using straw and wood 

Table 4. Seeding rates and species mixtures for 
establishment of permanent plant cover on coal 
refuse when applied in spring and fall.

Species Latin Name
Rate  

(lb/acre)

Spring seeding

Redtop Agrostis alba 3

Hard fescuea Festuca ovina 20

Tall fescue Festuca 
arundinacea

20

Annual ryegrass Lolium multiflorum 15

German millet Setaria italica 20

Weeping lovegrass Eragrostis curvula 3

Birdsfoot trefoil Lotus corniculatus 5

Yellow sweet 
clover

Melilotus officinalis 2

Ladino clover Trifolium repens 2

Kobe lespedeza Lespedeza striata 10

Fall seeding

Redtop Agrostis alba 3

Hard fescuea Festuca ovina 20

Tall fescue Festuca 
arundinacea

20

Annual ryegrass Lolium multiflorum 15

Cereal rye Secale cereale 25

Weeping lovegrass Eragrostis curvula 3

Birdsfoot trefoil Lotus corniculatus 5

Yellow sweet 
clover

Melilotus officinalis 5

Ladino clover Trifolium repens 2

Kobe lespedeza Lespedeza striata 10
a When using hard fescue, the varieties Scaldis or Reliant are 
recommended. 

www.ext.vt.edu

The inoculant should be added to the hydroseeder tank
immediately before seeding because the inoculant bac-
teria will perish if left in the high-salt environment of
the hydroseeder slurry for more than a few minutes. If
only grasses are to be used, the nitrogen rate should be
adjusted upward to 150 pounds per acre, but the grasses
will need additional nitrogen fertilizer in successive
years in the absence of legumes.

Seeding Rates and Species Mixtures

Selection of species suitable for planting on refuse is
complicated by the variability of the material. There-
fore, it is imperative to use species that will tolerate
a wide range of pH, moisture, and temperature condi-
tions, Consideration should also be given to the time
of year when seed is applied and to the overall goal of
establishing a diverse and permanent vegetative cover.
These criteria cannot be met by use of a single spe-
cies mixture on all sites or under all conditions. Pow-
ell River Project direct-seeding field trials, which were
established using the above criteria, have been suc-
cessful for five growing seasons and beyond on certain
refuse materials.

Species mixtures and seeding rates detailed in table 4
appear to be suitable for direct-seeding of refuse and for
use with topsoil covers. These recommendations were
based on the conditions at our various research sites;
the addition or deletion of species should be consid-
cred, depending on your local site conditions and seed
availability. Each mixture contains species adapted to a
variety of site conditions that are intended to overcome
local minesoil variability problems and make the mixes
usable on a variety of sites.

Spring seeding should occur after March 15 and before
May 15 for optimal results (table 5); fall seeding is rec
‘ommended between September 15 and November 15.
Environmental conditions during the summer and
ter are generally unfavorable for successful establish-
ment of mixed perennial vegetation, and annual covers
should only be seeded during these periods.

Commercially available wood fiber or paper mulches
at conventional application rates perform satisfactorily
for their intended use — the establishment of grasses
‘on topsoil. However, they are inadequate under the
extreme environmental stresses on refuse piles. Our
recommendation is that paper mulches be used at higher
rates (more than 2,000 pounds per acre) in the hydro-
seeder tank mix or in conjunction with straw mulch on
refuse, Field trials indicate that using straw and wood

Table 4, Seeding rates and species mixtures for
establishment of permanent plant cover on coal
refuse when applied in spring and fall.

Rate

Species Latin Name (ib/acre)

Spring seeding
Redtop Agrostis alba 3
Hard fescue* Festuca ovina 20
Tall fescue Festuca 20

arundinacea
Annual ryegrass Lolium multiflorum 15
German millet. Setaria italica 20
Weeping lovegrass Eragrostis curvula 3
Birdsfoot trefoil Lotus corniculatus 5
Yellow sweet Melilotus officinalis 2
clover
Ladino clover Trifolium repens 2
Kobe lespedeza __Lespedeza striata 10
Fall seeding

Redtop Agrostis alba 3
Hard fescue" Festuca ovina 20
Tall fescue Festuca 20

arundinacea

Annual ryegrass Lolium multiflorum 15
Cereal rye Secale cereale 25
Weeping lovegrass Eragrostis curvula 3
Birdsfoot trefoil Lotus corniculatus 5

Yellow sweet Melilotus officinalis. 5

clover
Ladino clover ‘Trifolium repens 2
Kobe lespedeza _Lespedeza striata 10

When using hard fescue, the varieties Scaldis or Reliant are
recommended,

Virginia Cooperative Extension | ywoxtvtedu
12




13

fiber/paper mulches together greatly improves plant 
establishment and long-term vigor, particularly on hot, 
south-facing fills. 

A technique that has proven successful in our work is 
as follows: 

1.   When loading the hydroseeder, include paper mulch 
to achieve 1,000 to 1,500 pounds per acre, along 
with the desired amount of seed and fertilizer.

2.   Spray this mixture in such a manner that it covers 
twice the normal area usually covered with a single 
tank (in other words, apply at half the normal rate).

3.   Next, using a mechanical straw blower or manual 
spreader, spread straw to cover the area just sprayed. 
Good coverage is achieved with 2,500 pounds per 
acre of straw. 

4.   Respray this area with the mulch/seed/fertilizer mix-
ture in the same manner as indicated above. 

By using this seeding method, several factors critical to 
successful establishment are ensured: 

1.   The shade provided by mulch reduces water loss 
from the seedbed and shields young seedlings from 
the high temperatures common to these areas. 

2.   The first tankful provides good seed/soil contact, 
which is necessary for good germination. 

3.   The use of straw mulch over this initial tankful pro-
vides shade that reduces water loss and lowers sur-
face temperatures. 

4.   The addition of the final tankful adds more seed and 

water, which may infiltrate the straw mulch, while 
the paper mulch tacks the straw mulch in place by 
forming a mat-like surface. 

While this technique adds to the cost and time involved, 
we feel that it is justified in terms of long-term estab-
lishment success, particularly on hot, droughty sites. 

In summary, any direct-seeding should be done with 
heavy mulch, applications of at least 350 pounds per 
acre of P2O5, and normal rates of nitrogen and potas-
sium, as discussed previously. Many direct-seeding 
alternatives may be impossible due to the difficulty of 
working amendments on steep fill faces. In these cases, 
some combination of lime and topsoil will be the only 
viable alternative. 

Tree Planting
Currently, very little has been documented about the use 
of woody plants for the reclamation and revegetation 
of coal refuse. Industry experience indicates that black 
locust (Robinia pseudoacacia L.), white pine (Pinus 
strobus), and red pine (Pinus resinosa) can be success-
fully direct-hydroseeded onto conditioned refuse. Some 
success has also been achieved using containerized tree 
seedlings. Several tree species (e.g., black birch, Betula 
lenta) are known to successfully colonize old refuse 
piles, but seeds or seedlings of these species are not 
readily available commercially. Refer to VCE publica-
tion 460-123 for a detailed discussion of establishing 
forests on mined lands. 

Native hardwoods can be used in coal refuse revegeta-
tion with a soil or topsoil substitute cover of adequate 
thickness. The cover should have physical and chemi-
cal properties suitable for the species to be planted. If 

Table 5. General timetable for reclamation practices suitable for revegetation of coal refuse areas.
Activity Date Recommendations
Final grading May 15-Sept. 15 Final grading should be done in a manner to avoid severe compaction of the 

surface.
Liming Year-round Liming rate should be based on measured potential acidity. Single applica-

tions should not exceed 25 tons/acre. Additional lime may be added at three-
month intervals.

Fertilization March 15-Nov. 15 If fertilizer is to be applied prior to seeding, nitrogen fertilizers should not be 
included.

Seeding March 15-May 15 Apply complete spring seeding mixture with fertilizers.
May 15-Sept. 15 Apply only millet with reduced rates of nitrogen.
Sept. 15-Nov. 15 Apply complete fall seeding mixture with fertilizers.
Nov. 15-March 15 Apply only cereal rye with reduced rates of nitrogen.

www.ext.vt.edu

Table 5. General timetable for reclamation practices suitable for revegetation of coal refuse areas.

Activity Date Recommendations
Final grading May 15-Sept. 15 Final grading should be done in a manner to avoid severe compaction of the
surface,

Liming Year-round ing rate should be based on measured potential acidity. Single applica-
tions should not exceed 25 tons/acte. Additional lime may be added at three-
month intervals.

If fertilizer is to be applied prior to seeding, nitrogen fertilizers should not be

included.

Fertilization March 15-Nov. 15

Seeding March 15-May 15
May 15-Sept. 15
Sept. 15-Nov. 15

Nov. 15-March 15

Apply complete spring seeding mixture with fertilizers
Apply only millet with reduced rates of nitrogen.
Apply complete fall seeding mixture with fertilizers
Apply only cereal rye with reduced rates of nitrogen.

fiber/paper mulches together greatly improves plant
establishment and long-term vigor, particularly on hot,
south-facing fills.

A technique that has proven successful in our work is
as follows:

1, When loading the hydroseeder, include paper mulch
to achieve 1,000 to 1,500 pounds per acre, along
with the desired amount of seed and fertilizer.

Spray this mixture in such a manner that it covers
twice the normal area usually covered with a single
tank (in other words, apply at half the normal rate)

3. Next, using a mechanical straw blower or manual
spreader, spread straw to cover the area just sprayed.
Good coverage is achieved with 2,500 pounds per
acre of straw.

4, Respray this area with the mulch/seed/ertilizer mix-
ture in the same manner as indicated above.

By using this seeding method, several factors critical to
successful establishment are ensured:

1, The shade provided by mulch reduces water loss
from the seedbed and shields young seedlings from
the high temperatures common to these areas.

2. The first tankful provides good seed/soil contact,
which is necessary for good germination.

3. The use of straw mulch over this initial tankful pro-
vides shade that reduces water loss and lowers sur-
face temperatures.

4, The addition of the final tankfuul adds more seed and

water, which may infiltrate the straw mulch, while
the paper mulch tacks the straw mulch in place by
forming a mat-like surface

While this technique adds to the cost and time involved,
wwe feel that itis justified in terms of long-term estab-
lishment success, particularly on hot, droughty sites.

In summary, any direct-seeding should be done with
heavy mulch, applications of at least 350 pounds per
acre of P,O,, and normal rates of nitrogen and potas-
sium, as discussed previously. Many direct-seeding
alternatives may be impossible due to the difficulty of
working amendments on steep fill faces. In these cases,
some combination of lime and topsoil will be the only
viable alternative.

Tree Planting

Currently, very little has been documented about the use
of woody plants for the reclamation and revegetation
of coal refuuse. Industry experience indicates that black
locust (Robinia pseudoacacia L.), white pine (Pinus
strobus), and red pine (Pinus resinosa) can be success-
fully direct-hydroseeded onto conditioned refuse. Some
success has also been achieved using containerized tree
seedlings. Several tree species (e.g., black birch, Betula
lenta) are known to successfully colonize old refuse
piles, but seeds or seedlings of these species are not
readily available commercially. Refer to VCE publica-
tion 460-123 for a detailed discussion of establishing
forests on mined lands.

Native hardwoods can be used in coal refuse revegeta-
tion with a soil or topsoil substitute cover of adequate
thickness. The cover should have physical and chemi
cal properties suitable for the species to be planted. If

Virginia Cooperative Extension | yweoxtvtedu
13




14

the intent for planting the hardwoods is an expectation 
that they will remain in place over the long term, the 
soil cover should be at least 4 feet in thickness, and a 
thicker cover is preferred. 

Post-Reclamation Management 
and Land Use
Current regulations require that the five-year bonding 
liability period begin after final reclamation and reveg-
etation are completed. Except for practices typical for 
the specified post-reclamation land use, further augmen-
tation of seed or soil amendments restarts the bonding 
period. When refuse disposal areas are being returned 
to unmanaged forest, augmentation is not considered 
by regulatory authorities to be a typical management 
practice. However, despite current regulations, we feel 
that augmentation, via split fertilizer applications or 
spot liming and seeding, is often necessary and should 
be a specified practice for the reclamation of coal refuse 
disposal areas via direct-seeding. Often, problem areas 
requiring this type of augmentation do not become 
apparent until the second or third growing season and 
may only cover a small area. While the area affected 
may not be large enough to preclude bond release, it 
may present a potential erosion or water quality threat 
in succeeding years. For this reason, augmentation 
treatment of these areas is encouraged. 

Long-Term Water Quality Concerns
The long-term emission of acidic leachates from refuse 
piles is a major problem. These leachates present a 
much more difficult challenge than surface revegeta-
tion. To stop leachate production, water flow through 
the fill must be limited, but this is very difficult in a 
humid leaching environment such as Virginia’s. 

There is evidence that a vigorous vegetative cover can 
reduce acid drainage by intercepting and transpiring 
rainfall, consuming oxygen in the rooting zone, and 
through several other mechanisms. However, the fun-
damental reaction thermodynamics of pyrite oxidation 
in the presence of water and oxygen cannot be ignored. 
Research has shown that establishment of a healthy 
vegetative cover alone cannot be expected to eliminate 
acid production and leaching from the interior of refuse 
piles. 

While various treatments have been shown to slow the 
rate of the acid-producing pyrite weathering reactions, 

eventually the reactions will continue to completion. The 
mass of sulfur within most disposal areas far exceeds 
the neutralization potential of any surface-applied 
treatments. Thus, unless water is completely excluded 
from the fill, even moderately sulfidic refuse materials 
should be expected to discharge acidic leachates and 
long-term water treatment strategies should be planned. 
For net-acid-producing refuse piles, these discharges 
will generally continue well beyond the five-year bond 
liability period. For such piles, the leachates will have 
to be neutralized with caustic additions and/or acid-
treatment wetlands. 

Acid-treatment wetlands are not currently accepted by 
regulatory authorities as a “walk-away” solution to acid 
leachate water quality problems. Where sufficient land 
area is available, however, wetland treatment systems 
have proven to be a more cost-effective means of treat-
ing acid water than alkaline chemical systems. Lack of 
sufficient land area in the right location has proven to 
be a major barrier to use of acid-treatment wetlands. 
Proper placement and design in the landscape can 
allow refuse fills to utilize acid-treatment wetland sys-
tems as a cost-effective means of leachate water treat-
ment. Design requirements of acid-treatment wetlands 
are reviewed in VCE publication 460-133. 

The only technology that is known to be effective in 
eliminating the acid leachate potential at refuse dis-
posal sites is the bulk blending of alkaline materials 
with the refuse as it is placed in the fill. Ground agri-
cultural limestone serves this purpose well but may be 
required at mixture ratios of up to 5 percent. This would 
add a considerable cost to refuse disposal. 

Our research has evaluated the potential to use alka-
line fly ash as a lime substitute for acid neutralization 
in refuse piles. In general, we have seen positive net 
water quality results where alkaline loadings have been 
properly matched to the host coal refuse acid-produc-
ing potential. However, we have observed negative 
water quality results when the ash/refuse mixtures have 
been allowed to acidify to less than pH 4.0 or where 
too much alkaline addition resulted in very high (more 
than 9.0) bulk pH. It is also important to point out that 
not all fly ash materials are alkaline, and the net water 
quality impacts of blending ash and other coal combus-
tion byproducts, such as scrubber sludges, with acid-
forming refuse materials must be carefully considered. 
Details on the use of coal combustion byproducts in 
mined land reclamation are given in VCE publication 
460-134. 

www.ext.vt.edu

the intent for planting the hardwoods is an expectation
that they will remain in place over the long term, the
soil cover should be at least 4 feet in thickness, and a
thicker cover is preferred.

Post-Reclamation Management
and Land Use

Current regulations require that the five-year bonding
liability period begin after final reclamation and reveg-
tation are completed. Except for practices typical for
the specified post-reclamation land use, further augmen-
tation of seed or soil amendments restarts the bonding
period. When refuse disposal areas are being returned
to unmanaged forest, augmentation is not considered
by regulatory authorities to be a typical management
practice. However, despite current regulations, we feel
that augmentation, via split fertilizer applications or
spot liming and seeding, is often necessary and should
bea specified practice for the reclamation of coal refuse
disposal areas via direct-seeding. Often, problem areas
requiring this type of augmentation do not become
apparent until the second or third growing season and
may only cover a small area, While the area affected
may not be large enough to preclude bond release, it
may present a potential erosion or water quality threat
in succeeding years. For this reason, augmentation
treatment of these areas is encouraged.

Long-Term Water Quality Concerns

The long-term emission of acidic leachates from refuse
piles is a major problem. These leachates present a
much more difficult challenge than surface revegeta-
tion. To stop leachate production, water flow through
the fill must be limited, but this is very difficult in a
humid leaching environment such as Virginia’s

There is evidence that a vigorous vegetative cover can
reduce acid drainage by intercepting and transpiring
rainfall, consuming oxygen in the rooting zone, and
through several other mechanisms. However, the fun-
damental reaction thermodynamics of pyrite oxidation
in the presence of water and oxygen cannot be ignored.
Research has shown that establishment of a healthy
vegetative cover alone cannot be expected to eliminate
acid production and leaching from the interior of refuse
piles.

While various treatments have been shown to slow the
rate of the acid-producing pyrite weathering reactions,

eventually the reactions will continue to completion. The
mass of sulfur within most disposal areas far exceeds
the neutralization potential of any surface-applied
treatments. Thus, unless water is completely excluded
from the fill, even moderately sulfidic refuse materials
should be expected to discharge acidic leachates and
long-term water treatment strategies should be planned.
For net-acid-producing refuse piles, these discharges
will generally continue well beyond the five-year bond
liability period. For such piles, the leachates will have
to be neutralized with caustic additions and/or acid-
treatment wetlands.

Acid-treatment wetlands are not currently accepted by
regulatory authorities as a “walk-away” solution to acid
leachate water quality problems. Where sufficient land
area is available, however, wetland treatment systems
have proven to be a more cost-effective means of treat-
ing acid water than alkaline chemical systems. Lack of
sufficient land area in the right location has proven to
be a major barrier to use of acid-treatment wetlands.
Proper placement and design in the landscape can
allow refuse fills to utilize acid-treatment wetland sys-
tems as a cost-effective means of leachate water treat-
ment. Design requirements of acid-treatment wetlands
are reviewed in VCE publication 460-133.

The only technology that is known to be effective in
eliminating the acid leachate potential at refuse dis-
posal sites is the bulk blending of alkaline materials
with the refuse as it is placed in the fill, Ground agri
cultural limestone serves this purpose well but may be
required at mixture ratios of up to 5 percent. This would
add a considerable cost to refuse disposal.

Our research has evaluated the potential to use alka-
line fly ash as a lime substitute for acid neutralization
in refuse piles. In general, we have seen positive net
water quality results where alkaline loadings have been
properly matched to the host coal refuse acid-produc-
ing potential. However, we have observed negative
water quality results when the ash/refuse mixtures have
been allowed to acidify to less than pH 4.0 or where
too much alkaline addition resulted in very high (more
than 9.0) bulk pH. It is also important to point out that
not all fly ash materials are alkaline, and the net water
quality impacts of blending ash and other coal combus-
tion byproducts, such as scrubber sludges, with ac
forming refuse materials must be carefully considered.
Details on the use of coal combustion byproducts in
mined land reclamation are given in VCE publication
460-134.

Virginia Cooperative Extension | ywoxtvtedu
14




15

Reprocessing and Remediation of 
Older Refuse Piles
Hundreds of pre-SMCRA coal refuse piles exist in the 
Virginia coalfield. Those of recent vintage are being or 
have been reclaimed to post-SMCRA environmental 
standards, and their coal content is often much less than 
the older piles that were created prior to the advent of 
improved coal separation technologies as well as the 
SMCRA. These older piles are the source of current 
concern for several reasons, including potential uses 
for the marketable coals that some contain and the envi-
ronmental impacts of the older piles, especially those 
subject to erosion and close to surface water streams 
(figure 2). As a result, there is a new emphasis on clean-
ing up these older piles for both coal recovery and envi-
ronmental remediation purposes (figure 9).

Such operations commonly occur under the jurisdiction 
of either Title IV (Abandoned Mine Reclamation) or 
Title V (which regulates active mining) of SMCRA. As 
such, reclamation and revegetation of the refuse reme-
diation site and of any refuse or reprocessing residue 
(such as scalp rock) that is either left on the reprocess-
ing site or disposed of elsewhere is required. The cost 
and amount of soil cover material required for success-
ful reclamation of these areas can be reduced if the 
operation identifies the refuse materials that are most 
favorable to revegetation and saves those materials for 
use in the revegetation process.

This material segregation can often be done without 
great difficulty because the most favorable materi-
als are typically those that occur on the surface of the 
refuse pile, where long-term exposure to air and rainfall 
has caused them to weather and become more like soil 
materials than the underlying refuse.

In order to take advantage of these materials, we 
recommend that they be identified and characterized 
prior to any disturbance. For reprocessing opera-
tions, the most logical time to do this is during the 
initial characterization of the material from various 
locations in the pile. As this process occurs, we rec-
ommend that a sample of the upper surface material 
also be retained and characterized for its revegetation 
potential. The more-weathered material is usually the 
best for revegetation, and this material can usually be 
identified visually because it has been discolored by 
the weathering process; it may extend for several feet 
into the pile. This material can be characterized for 
chemical properties, including pH, potential acidity, 

and particle size, and evaluated using the guidelines 
of table 3. If volunteer plants are growing on the pile 
surface, this is an indication that the materials have 
favorable properties for revegetation.

When checking refuse properties, be aware of the 
potential for elevated temperatures inside the pile. If 
high temperatures are observed, notify the Virginia 
Division of Mined Land Reclamation immediately. 
Although spontaneous combustion of coal refuse 
rarely occurs, it sometimes happens. At least one fire 
in a Virginia abandoned mine land (AML) refuse pile 
occurred when the surface material was disturbed in 
advance of potential reprocessing, allowing atmo-
spheric oxygen to access the pile interior where ele-
vated temperatures had built up due to precombustion 
oxidation processes. The vast majority of Virginia 
coal refuse piles do not suffer from this condition 
but caution is warranted because of the few that do. 
Coal refuse materials containing significant quantities 
of combustible carbon should not be used for direct-
seeding due to the potential for accidental combustion 
that may be caused by lightning, vandalism, or other 
means.

Figure 9. Reprocessing and removing older refuse 
materials, including pre-SMCRA abandoned mine land 
piles, is becoming increasingly common in southwestern 
Virginia, both for the purpose of salvaging marketable 
coals and for environmental remediation. When the 
surface materials of these older piles are sufficiently 
weathered to enable them to support vegetation, 
separating and retaining these materials for use in 
reclamation can save money and it can reduce or 
eliminate the environmental disturbance required to 
obtain soil cover that otherwise would be needed to 
restore the area. 

www.ext.vt.edu

Reprocessing and Remediation of
Older Refuse Piles

Hundreds of pre-SMCRA coal refuse piles exist in the
Virginia coalfield, Those of recent vintage are being or
have been reclaimed to post-SMCRA environmental
standards, and their coal content is often much less than
the older piles that were created prior to the advent of
improved coal separation technologies as well as the
SMCRA. These older piles are the source of current
concer for several reasons, including potential uses
for the marketable coals that some contain and the envi-
ronmental impacts of the older piles, especially those
subject to erosion and close to surface water streams
(figure 2). As a result, there is a new emphasis on clean-
ing up these older piles for both coal recovery and envi-
ronmental remediation purposes (figure 9).

Such operations commonly occur under the juris
of either Title IV (Abandoned Mine Reclamation) or
Title V (which regulates active mining) of SMCRA. As
such, reclamation and revegetation of the refuse reme-
diation site and of any refuse or reprocessing residue
(such as scalp rock) that is either left on the reprocess-
ing site or disposed of elsewhere is required, The cost
and amount of soil cover material required for succes
ful reclamation of these areas can be reduced if the
operation identifies the refuse materials that are most
favorable to revegetation and saves those materials for
use in the revegetation process.

This material segregation can often be done without
great difficulty because the most favorable materi-
als are typically those that occur on the surface of the
refuse pile, where long-term exposure to air and rainfall
has caused them to weather and become more like soil
materials than the underlying refuse.

In order to take advantage of these materials, we
recommend that they be identified and characterized
prior to any disturbance. For reprocessing opera-
tions, the most logical time to do this is during the
initial characterization of the material from various
locations in the pile. As this process occurs, we rec-
‘ommend that a sample of the upper surface material
also be retained and characterized for its revegetation
potential. The more-weathered material is usually the
best for revegetation, and this material can usually be
identified visually because it has been discolored by
the weathering process; it may extend for several feet
into the pile. This material can be characterized for
chemical properties, including pH, potential acidity,

and particle size, and evaluated using the guidelines
of table 3. If volunteer plants are growing on the pile
surface, this is an indication that the materials have
favorable properties for revegetation.

When checking refuse properties, be aware of the
potential for elevated temperatures inside the pile. If
high temperatures are observed, notify the Virginia
Division of Mined Land Reclamation immediately.
Although spontaneous combustion of coal refuse
rarely occurs, it sometimes happens. At least one fire
ina Virginia abandoned mine land (AML) refuse pile
occurred when the surface material was disturbed in
advance of potential reprocessing, allowing atmo-
spheric oxygen to access the pile interior where ele-
vated temperatures had built up due to precombustion
oxidation processes. The vast majority of Virginia
coal refuse piles do not suffer from this condition
but caution is warranted because of the few that do,
Coal refuse materials containing significant quantities
of combustible carbon should not be used for direct-
seeding due to the potential for accidental combustion
that may be caused by lightning, vandalism, or other
means.

Figure 9. Reprocessing and removing older refuse
‘materials, including pre-SMCRA abandoned mine land
piles, is becoming increasingly common in southwestern
Virginia, both for the purpose of salvaging marketable
coals and for environmental remediation. When the

surface materials of these older piles are sufficiently
weathered to enable them to support vegetation,
separating and retaining these materials for use in
reclamation can save money and it can reduce or
eliminate the environmental disturbance required to
obtain soil cover that otherwise would be needed to
restore the area.

Virginia Cooperative Extension | yweoxtvtedu
15




16

Summary and Recommendations
The Appalachian coal industry has made great prog-
ress in coal refuse reclamation over the past 20 years. 
However, further improvements are needed to ensure 
that the industry is not faced with significant long-term 
liabilities. Refuse disposal areas should be designed 
and constructed with long-term stabilization and water 
quality concerns in mind. In particular, fill hydrology 
and its interaction with pyrite weathering and seepage 
should be considered when designing and constructing 
refuse fills. The surface reclamation strategy should 
be designed to maintain a vigorous plant cover and to 
neutralize surface acidity and water-holding limitations 
over time. Excessively steep slopes are very difficult 
to treat as is needed to establish permanent vegetation 
and should be minimized where possible. The land area 
requirements of constructed wetland water treatment 
strategies, which are capable of reducing the long-term 
costs of leachate water treatment, should be considered 
in fill design. 

The long-term acid generation potential of a refuse pile 
must be taken into account during reclamation and clo-
sure planning. Currently, bulk blending of lime or other 
alkaline materials is the only viable long-term approach 
for controlling or eliminating the release of acid mine 
drainage by acidic refuse. 

Even after the pile has been reclaimed and revegetated, 
either with or without topsoil cover, most coal refuse 
disposal sites should be considered as potential envi-
ronmental liabilities, with restricted public access and 
protection from disturbance. A surface disturbance 
that exposes underlying materials can create erosion 
hazards if those exposed materials fail to revegetate 
quickly and naturally. If the pile contains pyritic mate-
rials, any activity that opens the pile surface and allows 
oxygen and water to enter the interior can renew or 
accelerate pyrite oxidation. Coal refuse materials are 
predominantly of natural geologic origin and — due 
to the effects of environmental processes over time — 
will eventually become benign, but the potential liabili-
ties associated with reclaimed coal refuse piles can be 
expected to last for decades or longer. Over those time 
scales, the piles should remain protected.

Acknowledgments
This paper summarizes the collective work and insights 
of a number of people working with us on the Powell 
River Project coal refuse research study. Katie Haering, 

Vince Ruark, Jay Bell, and Dennis Dove all contrib-
uted immeasurably to our understanding of this prob-
lem through their collective efforts. We wish to thank 
a number of individuals who were working with the 
coal industry at the time of this research, including 
Eddie Hannah, Mark Singleton, Ken Roddenberry, 
Steve Sutphin, Ron Keene, and Roger Jones. We also 
thank a number of mining firms for their generous help 
and cooperation throughout our studies, including Jew-
ell Smokeless, the former Westmoreland Coal, United 
Coal, Paramont Mining (now Alpha Natural Resources), 
and Consolidation Coal (now Consol Energy). We also 
received invaluable help in the field from Ron Alls, the 
late Ren-sheng Li, and Velva Groover. 

The research that allowed us to reach this level of 
understanding was supported by the Powell River Proj-
ect, the Virginia Center for Innovative Technology, and 
the former U.S. Bureau of Mines. 

References

Powell River Project/Virginia Cooperative 
Extension (VCE) Publications
Burger, J. A., and C. E. Zipper. How to Restore Forests 

on Surface-Mined Land. VCE publication 460-123.

Daniels, W., B. Stewart, K. Haering, and C. E. Zipper. 
The Potential for Beneficial Reuse of Coal Fly Ash 
in Southwest Virginia Mining Environments. VCE 
publication 460-134.

Daniels, W. L., and C. E. Zipper. Creation and Man-
agement of Productive Mine Soils. VCE publica-
tion 460-121.

Skousen, J., and C. E. Zipper. Revegetation Species and 
Practices. VCE publication 460-122.

Zipper, C. E., J. Skousen, and C. Jage. Passive Treat-
ment of Acid-Mine Drainage. VCE publication 
460-133.

Other References
Daniels, W. L., and B. A. Stewart. 2000. Reclamation 

of Appalachian coal refuse disposal areas. In Recla-
mation of Drastically Disturbed Lands. Agronomy 
No. 41, Chapter 17. Ed. R. I. Barnhisel, R. G. Dar-
mody, and W. L. Daniels. Madison, Wis.: American 
Society of Agronomy.

www.ext.vt.edu

Summary and Recommendations

The Appalachian coal industry has made great prog-
ress in coal refuse reclamation over the past 20 years.
However, further improvements are needed to ensure
that the industry is not faced with significant long-term
liabilities. Refuse disposal areas should be designed
and constructed with long-term stabilization and water
quality concems in mind. In particular, fill hydrology
and its interaction with pyrite weathering and seepage
should be considered when designing and constructing
refuse fills, The surface reclamation strategy should
be designed to maintain a vigorous plant cover and to
neutralize surface acidity and water-holding limitations
over time, Excessively steep slopes are very difficult
to treat as is needed to establish permanent vegetation
and should be minimized where possible. The land area
requirements of constructed wetland water treatment
strategies, which are capable of reducing the long-term
costs of leachate water treatment, should be considered
fill design.

‘The long-term acid generation potential of a refuse pile
must be taken into account during reclamation and clo-
sure planning. Currently, bulk blending of lime or other
alkaline materials is the only viable long-term approach
for controlling or eliminating the release of acid mine
drainage by acidic refuse.

Even after the pile has been reclaimed and revegetated,
either with or without topsoil cover, most coal refuse
disposal sites should be considered as potential envi-
ronmental liabilities, with restricted public access and
protection from disturbance. A surface disturbance
that exposes underlying materials can create erosion
hazards if those exposed materials fail to revegetate
quickly and naturally, If the pile contains pyritic mate-
rials, any activity that opens the pile surface and allows
oxygen and water to enter the interior can renew or
accelerate pyrite oxidation, Coal refuse materials are
predominantly of natural geologic origin and — due
to the effects of environmental processes over time
will eventually become benign, but the potential liabili-
ties associated with reclaimed coal refuse piles can be
expected to last for decades or longer. Over those time
scales, the piles should remain protected.

Acknowledgments

This paper summarizes the collective work and insights
of a number of people working with us on the Powell
River Project coal refuse research study. Katie Haering,

‘ive Extensi

Virginia Coopera

Vince Ruark, Jay Bell, and Dennis Dove all contrib-
uted immeasurably to our understanding of this prob-
lem through their collective efforts. We wish to thank
a number of individuals who were working with the
coal industry at the time of this research, including
Eddie Hannah, Mark Singleton, Ken Roddenberry,
Steve Sutphin, Ron Keene, and Roger Jones. We also
thank a number of mining firms for their generous help
and cooperation throughout our studies, including Jew-
ell Smokeless, the former Westmoreland Coal, United
Coal, Paramont Mining (now Alpha Natural Resources),
and Consolidation Coal (now Consol Energy). We also
received invaluable help in the field from Ron Alls, the
late Ren-sheng Li, and Velva Groover.

The research that allowed us to reach this level of
understanding was supported by the Powell River Proj-
ect, the Virginia Center for Innovative Technology, and
the former U.S. Bureau of Mines.

References

Powell River Project/Virginia Cooperative
Extension (VCE) Publications

Burger, J. A., and C. E. Zipper. How to Restore Forests
on Surface-Mined Land. VCE publication 460-123.

Daniels, W., B. Stewart, K. Haering, and C. E. Zipper.
The Potential for Beneficial Reuse of Coal Fly Ash
in Southwest Virginia Mining Environments. VCE.
publication 460-134.

Daniels, W. L., and C. E. Zipper. Creation and Man-
agement of Productive Mine Soils. WCE publica-
tion 460-121.

Skousen, J., and C. E, Zipper. Revegetation Species and
Practices. VCE publication 460-122.

Zipper, C. E., J. Skousen, and C. Jage. Passive Treat-
ment of Acid-Mine Drainage. VCE. publication
460-133.

Other References

Daniels, W. L., and B. A. Stewart. 2000. Reclamation
of Appalachian coal refuse disposal areas. In Recla-
mation of Drastically Disturbed Lands. Agronomy
No. 41, Chapter 17. Ed. R. I. Barnhisel, R. G. Dar-
mody, and W. L. Daniels. Madison, Wis.: American
Society of Agronomy.

mt certo
16




17

Helmke, P. A. 1999. The chemical composition of soils. 
In Handbook of Soil Science. Ed. M. E. Sumner. 
Boca Raton, Fla.: CRC Press.

National Research Council (NRC), National Academy 
of Sciences. 1979. Redistribution of Accessory Ele-
ments in Mining and Mineral Processing, Part I. 
Washington, D.C.: National Academy Press.

Nawrot, J., and B. Gray. 2000. Principles and practices 
of tailings reclamation: Coal refuse. In Reclama-
tion of Drastically Disturbed Lands. Agronomy 
No. 41, Chapter 18. Ed. R. I. Barnhisel, R. G. Dar-
mody, and W. L. Daniels. Madison, Wis.: American 
Society of Agronomy.

Rose, J. G., T. I. Robi, and A. E. Bland. 1976. Com-
position and properties of refuse from Kentucky 
preparation plants. In Proceedings, Fifth Mineral 
Waste Utilization Symposium, 122-31. Chicago: 
U.S. Bureau of Mines and ITT Research Institute.

Stewart, B. R., and W. L. Daniels. 1992. Physical and chem-
ical properties of coal refuse from Southwest Virginia. 
Journal of Environmental Quality 21:635-42.

Virginia Department of Mines, Minerals and Energy. Vir-
ginia Administrative Code, Title 4, Agency 25, Chap-
ter 130, Section 816.83 (Coal mine waste; refuse 
piles). http://leg1.state.va.us/000/reg/TOC.HTM.

Additional Resources
Buttermore, W. H., E. J. Simcoe, and M. A. Maloy. 

1978. Characterization of Coal Refuse. Technical 
Report No. 159, Coal Research Bureau. Morgan-
town: West Virginia University.

Daniels, W. L., and D. C. Dove. 1987. Revegetation 
strategies for coal refuse areas. In Proceedings, 
Eighth Annual West Virginia Surface Mine Drain-
age Task Force Symposium, F1-13. West Virginia 
Surface Mine Drainage Task Force. Morgantown: 
West Virginia University.

Daniels, W. L., K. C. Haering, and D. C. Dove. 1989. 
Long-term strategies for reclaiming and manag-
ing coal refuse disposal areas. Virginia Coal and 
Energy Journal 1 (1): 45-59.

Daniels, W. L., K. C. Haering, B. R. Stewart, R. V. 
Ruark, and D. C. Dove. 1990. New technologies 
for the stabilization and reclamation of coal refuse 

materials. In Proceedings, 1990 Powell River Proj-
ect Symposium, 1-20. Powell River Project. Blacks-
burg: Virginia Tech.

Davidson, W. A. 1974. Reclaiming refuse banks from 
underground bituminous mines in Pennsylva-
nia. In Proceedings, First Symposium on Mine 
and Preparation Plant Refuse Disposal. National 
Coal Association and Bituminous Coal Research, 
Coal Conference and Expo II. Washington, D.C.: 
National Coal Association.

Dove, D. C., W. L. Daniels, and J. Bell. 1987. Recla-
mation of coal wastes with reduced soil depth and 
other amendments. In Proceedings, Fourth Annual 
Meeting of the American Society for Surface Min-
ing and Reclamation, L1, 1-9. Princeton, W.Va.: 
ASSMR.

Jastrow, J. D., A. J. Dvorak, M. J. Knight, and B. K. 
Mueller. 1981. Revegetation of Acidic Coal Refuse: 
Effects of Soil Cover Material Depth and Lim-
ing Rate on Initial Establishment. ANL/LRP-3. 
Argonne, Ill.: Argonne National Laboratory.

Joost, R. E., F. J. Olsen, and J. H. Jones. 1987. Reveg-
etation and minesoil development of coal refuse 
amended with sewage sludge and limestone. Jour-
nal of Environmental Quality l6 (1): 91-94.

Nickerson, F. H. 1984. Vegetative cover grows directly 
on acidic mine refuse pile. Coal Mining & Process-
ing (February 1984): 39-43.

Robl, T. L., A. E. Bland, and J. G. Rose. 1976. Ken-
tucky coal refuse: A geotechnical assessment of its 
potential as a metals source. In Preprints, Second 
Symposium on Coal Preparation, 152-59. National 
Coal Association and Bituminous Coal Research, 
Coal Conference and Expo III. Washington, D.C.: 
National Coal Association.

Schramm, J. R. 1966. Plant colonization studies on 
black wastes from anthracite mining in Pennsylva-
nia. New Series: Vol. 56, Part 1 of Transactions of 
the American Philosophical Society. Philadelphia: 
American Philosophical Society.

Stewart, B. R. 1990. Physical and Chemical Properties 
of Coarse Coal Refuse From Southwest Virginia. 
M.S. thesis, Crop and Soil Environmental Sci-
ences, Virginia Tech.

www.ext.vt.edu

Helmke, P. A. 1999. The chemical composition of soils,
In Handbook of Soil Science. Ed. M. E. Sumner.
Boca Raton, Fla.: CRC Press.

National Research Council (NRC), National Academy
of Sciences, 1979. Redistribution of Accessory Ele~
‘ments in Mining and Mineral Processing, Part 1.
Washington, D.C.: National Academy Press.

Nawrot, J., and B, Gray. 2000, Principles and practices
of tailings reclamation: Coal refuse. In Reclama-
tion of Drastically Disturbed Lands. Agronomy
No. 41, Chapter 18. Ed. R. I, Barnhisel, R. G. Dar-
mody, and W. L. Daniels. Madison, Wis.: American
Society of Agronomy.

Rose, J. G., T. I, Robi, and A. E. Bland, 1976. Com-
position and properties of refuse from Kentucky
preparation plants. In Proceedings, Fifth Mineral
Waste Utilization Symposium, 122-31. Chicago:
U.S. Bureau of Mines and ITT Research Institute.

Stewart, B. R.,and W. L. Daniels. 1992. Physical and chem-
ical properties of coal refuse fiom Southwest Virginia.
Journal of Environmental Quality 21:635-42.

Virginia Department of Mines, Minerals and Energy. Vit-
ginia Administrative Code, Title 4, Agency 25, Chap-
ter 130, Section 816.83 (Coal mine waste; refuse
piles). hutp:/Mlegl state.va.us/000/reg/TOC.HTM.

Additional Resources

Buttermore, W. H., E. J. Simeoe, and M. A. Maloy.
1978. Characterization of Coal Refuse. Technical
Report No. 159, Coal Research Bureau. Morgan-
town: West Virginia University.

Daniels, W. L., and D. C. Dove. 1987. Revegetation
strategies for coal refuse areas. In Proceedings,
Eighth Annual West Virginia Surface Mine Drain
age Task Force Symposiun, F1-13. West Virginia
Surface Mine Drainage Task Force. Morgantown:
West Virginia University.

Daniels, W. L., K. C. Haering, and D. C. Dove. 1989.
Long-term strategies for reclaiming and manag-
ing coal refuse disposal areas. Virginia Coal and
Energy Journal | (1): 45-59.

Daniels, W. L., K. C. Haering, B. R. Stewart, R. V.
Ruark, and D. C. Dove. 1990. New technologies
for the stabilization and reclamation of coal refuse

‘ive Extensi

Virgin

Coopera

materials. In Proceedings, 1990 Powell River Proj-
ect Symposium, 1-20, Powell River Project. Blacks-
burg: Virginia Tech.

Davidson, W. A. 1974, Reclaiming refuse banks from
underground bituminous mines in  Pennsylva-
nia, In Proceedings, First Symposium on Mine
and Preparation Plant Refuse Disposal. National
Coal Association and Bituminous Coal Research,
Coal Conference and Expo II. Washington, D.C.:
National Coal Association

Dove, D. C., W. L. Daniels, and J. Bell. 1987, Recla-
mation of coal wastes with reduced soil depth and
other amendments. In Proceedings, Fourth Annual
Meeting of the American Society for Surface Min-
ing and Reclamation, L1, 1-9. Princeton, W.Va.:
ASSMR.

Jastrow, J. D., A. J. Dvorak, M. J. Knight, and B. K.
Mueller. 1981. Revegetation of Acidic Coal Refuse:
Effects of Soil Cover Material Depth and Lim-
ing Rate on Initial Establishment, ANLILRP-3.
Argonne, Ill: Argonne National Laboratory.

Joost, R. E., F. J. Olsen, and J. H. Jones. 1987. Reveg-
etation and minesoil development of coal refuse
amended with sewage sludge and limestone. Jour-
nal of Environmental Quality 16 (1): 91-94.

Nickerson, F. H. 1984. Vegetative cover grows directly
on acidic mine refuse pile. Coal Mining & Process-
ing (February 1984); 39-43,

Robl, T. L., A. E. Bland, and J. G. Rose. 1976. Ken-
tucky coal refuse: A geotechnical assessment of its
potential as a metals source. In Preprints, Second
‘Symposium on Coal Preparation, 152-59. National
Coal Association and Bituminous Coal Research,
Coal Conference and Expo III. Washington, D.C.
National Coal Association.

Schramm, J. R. 1966. Plant colonization studies on
black wastes from anthracite mining in Pennsylva-
nia. New Series: Vol. 56, Part | of Transactions of
the American Philosophical Society. Philadelphia:
American Philosophical Society.

Stewart, B. R. 1990. Physical and Chemical Properties
of Coarse Coal Refuse From Southwest Virginia.
MS. thesis, Crop and Soil Environmental Sci-

rginia Tech,

ences,

mt certo
7