v>EPA
United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
P.O. Box 15027
Las Vegas NV89114
EPA-600/7-80-109
June 1980
Research and Development
Groundwater Quality
Monitoring of Western
Coal Strip Mining:
Preliminary Designs
for Reclaimed Mine
Sources of Pollution
Interagency Energy-
Environment Research
and Development
Program Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad categories
were established to facilitate further development and application of environmental
technology. Elimination of traditional grouping was consciously planned to foster
technology transfer and a maximum interface in related fields. The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY—ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the effort
funded under the 17-agency Federal Energy/Environment Research and Development
Program. These studies relate to EPA'S mission to protect the public health and welfare
from adverse effects of pollutants associated with energy systems. The goal of the Pro-
gram is to assure the rapid development of domestic energy supplies in an environ-
mentally-compatible manner by providing the necessary environmental data and
control technology. Investigations include analyses of the transport of energy-related
pollutants and their health and ecological effects; assessments of, and development of,
control technologies for energy systems; and integrated assessments of a wide range
of energy-related environmental issues.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161
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EPA-600/7-80-109
June 1980
GROUNDWATER QUALITY MONITORING OF WESTERN COAL STRIP MINING:
Preliminary Designs for Reclaimed Mine Sources of Pollution
Edited by
Lome G. Everett
Edward W. Hoylman
General Electric Company—TEMPO
Center for Advanced Studies
Santa Barbara, California 93102
Contract No. 68-03-2449
Project Officer
Leslie G. McMillion
Advanced Monitoring Division
Environmental Monitoring Systems Laboratory
Las Vegas, Nevada 89114
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring Systems
Laboratory-Las Vegas, U.S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily reflect
the views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or rec-
ommendation for use.
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FOREWORD
Protection of the environment requires effective regulatory actions
based on sound technical and scientific data. The data must include the
quantitative description and linking of pollutant sources, transport
mechanisms, interactions, and resulting effects on man and his environment.
Because of the complexities involved, assessment of exposure to specific
pollutants in the environment requires a total systems approach that
transcends the media of air, water, and land. The Environmental Monitoring
Systems Laboratory at Las Vegas contributes to the formation and enhancement
of a sound monitoring-data base for exposure assessment through programs
designed to:
• develop and optimize systems and strategies for moni-
toring pollutants and their impact on the environment
• demonstrate new monitoring systems and technologies
by applying them to fulfill special monitoring needs
of the Agency's operating programs
This report presents the second phase of a study to design and verify
groundwater quality monitoring programs for western coal strip mining. The
development of a groundwater quality monitoring design for potential pollution
sources and the pollutants associated with reclaimed mine sources of pollution
is presented. The results herein will lead to a data verification effort. It
is anticipated that the verification program will result in modification to
this initial monitoring design.
Further information on this study and the subject of groundwater quality
monitoring in general can be obtained by contacting the Environmental
Monitoring Systems Laboratory, U.S. Environmental Protection Agency, Las
Vegas, Nevada.
Glenn E. Schweitzer
Director
Environmental Monitoring Systems Laboratory
Las Vegas
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PREFACE
General Electric—TEMPO, Center for Advanced Studies, is conducting a
5-year program dealing with the design and verification of an exemplary
groundwater quality monitoring program for western coal strip mining. The
coal strip mining activity discussed in this report is located in Campbell
County, Wyoming. In addition to active mine sources and reclaimed mine
sources, the investigation covers secondary water resource impacts of muni-
cipal and industrial support programs which accompany the mining effort. The
report follows a stepwise monitoring methodology developed by TEMPO.
This report represents the second phase of this research program. De-
scribed herein is the initial design of a groundwater quality monitoring pro-
gram for potential pollution sources and pollutants associated with reclaimed
mine areas.
In the next phases of this research program, the preliminary monitoring
designs are to be verified with existing data. Initial verification study
results may produce a reevaluation of the monitoring design presented in this
report. The final product of the 5-year program will be a planning document
for coal development companies and the various governmental agencies concerned
with environmental planning and protection.
IV
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SUMMARY
Monitoring design guidelines to assess the impact on groundwater quality
from reclaimed mine sources of pollution is the subject of this fourth report
in a series developed for western coal strip mining.
The initial report (Everett, 1979) dealt with the identification of po-
tential sources of groundwater quality impact; characteristics of potential
pollutants; source-area hydrogeology and groundwater quality; and infiltra-
tion and mobility of pollutants in the subsurface. These assessments focused
on a case study region around Gillette, Wyoming. Subsequent reports develop
guidelines for groundwater quality monitoring programs for active mine and
municipal sources of pollution.
Preliminary monitoring designs for reclaimed mine sources are presented
in the following sections of this report. The term "design" is used in a
broad sense here to mean a structured sequence of data-gathering, evaluation,
and decision steps which result in a determination of what monitoring activi-
ties are needed and what the appropriate methods are for addressing these
needs. The recommended monitoring approach for each potential pollution
source constitutes the recommended design.
Potential sources of groundwater quality impact associated with reclaimed
mines have been grouped into two categories for consideration in this report:
• Spoils, including overburden, interseam partings, coal, coal
refuse, and coaly waste
• Reclamation aids, including fertilizers and soil amendments.
Ranking of pollution sources is based on a sequence of data compilation
and evaluation steps which comprise a conceptual design methodology. This
methodology is discussed by Everett (1979). The three basic criteria used to
develop the source-pollutant ranking are:
• Mass of waste, persistence, toxicity, and concentration
• Potential mobility
• Known or anticipated harm to water use.
An extensive study of the hydrogeology of mine areas, coal strip mine
development, and environmental effects has shown that significant information
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voids exist with regard to mobility and potential pollutant characterization
of source materials within the hydrosphere. Therefore, professional judgment
plays a large role in proposing this preliminary source-pollutant ranking
which is as follows (Everett, 1979):
Coal Strip Mining: 1. Spoils (below water table)
2. Spoils (above water table below ponds or streams)
3. Pit discharge (to streams).
Of these ranked pollution sources, spoils are described in this report
and pit discharge to streams via sedimentation ponds is discussed in the pre-
liminary design report for active mine sources.
The generic monitoring methodology which was utilized herein was devel-
oped by General Electric--TEMPO and includes the following information as-
sessment steps:
• Identify potential pollutants
• Define groundwater usage
e Define hydrogeolgic situation
• Study existing groundwater quality
• Evaluate infiltration potential
• Evaluate mobility of pollutants in the vadose zone
• Evaluate attenuation of pollutants in the saturated zone.
Monitoring needs and alternate approaches to address these needs are evalu-
ated at each step. Technical assessment and monitoring costs relative to the
potential for impact on groundwater quality result in selection of a monitor-
ing approach. Quite often, information gathered through the selected moni-
toring approach for one step will refocus monitoring needs and provide a data
base for alternate steps. It is important to note that each step in this de-
sign sequence is a decision point. If the technical assessment indicates the
absence of potential for impact to groundwater quality, then this conclusion
is the end product for the monitoring design.
Multiple passes through the methodology steps, with successive passes
dealing with more detailed data sets and generally higher costs for develop-
ing required information, are employed to "scale-up" to an appropriate and
cost-effective level of monitoring effort. Thus, at specific sites, differ-
ent monitoring designs may result for any of the potential pollution sources
considered in this report.
The above-outlined sequence of steps is followed through entirely and a
monitoring approach is "selected." As with the designs developed in previous
vi
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reports, these guidelines are generally applicable throughout the western
coal-development States. Case studies have been included in earlier reports
to balance this factor; however, none of the mines within the study area are
engaged in the reclamation activities, and data for case studies are lacking.
For this reason, no site-specific samples have been included herein.
Tables A-l and A-2, Appendix A, give summaries of preliminary monitoring
design for regraded spoils and reclamation aids, respectively. For each mon-
itoring step, needs and alternative monitoring approaches to meet these needs
are discussed. Preliminary monitoring recommendations and cost allocations
are selected from these alternatives. Major cost items (i.e., develop a mon-
itor well) are initiated in response to evaluation of specific pollution
sources which are judged to constitute a signficant threat to the groundwater
quality. This point is not brought out in Tables A-l and A-2 and should be
kept in mind when evaluating the cost-effectiveness of the monitoring designs
provided herein. Costs are provided for the preliminary recommended monitor-
ing approach which has been selected from a series of alternative monitoring
approaches.
vn
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CONTENTS
Foreword
Preface
Summary
Figures
Tables
List of Abbreviations
Acknowledgments
Section
1 MONITORING DESIGN FOR SPOILS
Introduction
Identify Potential Pollutants
Define Groundwater Usage
Define Hydrogeologic Situation
Study Existing Groundwater Quality
Evaluate Infiltration Potential
Evaluate Mobility of Pollutants in the Vadose Zone
Evaluate Attenuation of Pollutants in the Saturated Zone
2 MONITORING DESIGN FOR RECLAMATION AIDS
Introduction
Identify Potential Pollutants
Define Groundwater Usage
Define Hydrogeologic Situation
Study Existing Groundwater Quality
Evaluate Infiltration Potential
Evaluate Mobility of Pollutants in the Vadose Zone
Evaluate Attenuation of Pollutants in the Saturated Zone
References
Appendix
A Summary of Preliminary Monitoring Designs
B Metric Conversion Table
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x
xi
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1
1
2
4
5
6
7
8
9
15
15
15
17
18
19
21
21
25
27
29
37
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FIGURES
Number Page
1 Distribution of nitrates through colums of coarse-textured
soils after adding 3.29 cm of water. 22
TABLES
Number Page
1 Processes Which May Control Amounts of Certain Constituents
in Subsurface Waters Contaminated by Waste Disposal 23
A-l Summary of Preliminary Recommended Monitoring Approaches
for Regraded Mine Spoils 30
A-2 Summary of Preliminary Monitoring Design for Reclamation
Aids 34
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LIST OF ABBREVIATIONS
afa acre-feet annually
CEC cation exchange capacity
DO dissolved oxygen
EC electrical conductivity
Eh oxidation reduction
fc infiltration rate
ppm parts per million
PVC polyvinyl chloride
SAR sodium absorption ratio
TDS total dissolved solids
TOC total organic carbon
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ACKNOWLEDGMENTS
Dr. Lome 6. Everett of General Electrio-TEMPO was responsible for
management and technical guidance of the project under which this report was
prepared. Mr. Edward W. Hoylman was responsible for the organization and
presentation of the report. Principal TEMPO authors were: Dr. Lome G.
Everett, Mr. Edward W. Hoylman, and Dr. Guenton C. Slawson, Jr.
Principal consultant authors were: Dr. S.N. Davis, University of Ari-
zona, Tuscon, Arizona; Ms. Margery A. Hulburt, Department of Environmental
Quality, Cheyenne, Wyoming; Mr. Louis Meschede, Dr. Roger Peebles, Dr. John
L. Thames and Dr. L. Graham Wilson, University of Arizona, Tucson, Arizona;
Dr. Kenneth D. Schmidt, Consultant, Fresno, California; Dr. Richard M. Tinlin,
Consultant, Camp Verde, Arizona; Dr. David K. Todd, University of California,
Berkeley; and Dr. Donald L. Warner, University of Missouri, Roll a.
Xll
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SECTION 1
MONITORING DESIGN FOR SPOILS
INTRODUCTION
The Surface Mining Control and Reclamation Act of 1977 has resulted in a
number of reclamation and enforcement provisions for strip mines (U.S. Depart-
ment of Interior, 1977). Section 715.17 of the Surface Mining Reclamation and
Enforcement Provisions deals with protection of the hydrologic system. The
provisions state that changes in water quality shall be minimized such that
the postmining use of the disturbed land is not adversely affected. Further-
more, operations shall be conducted so as to minimize water pollution. Prac-
tices to control and minimize pollution include sealing acid-forming and
toxic-forming materials and selectively placing waste materials in backfill
areas. Lastly, when operations are conducted in such a manner that may af-
fect the groundwater, water levels and groundwater quality shall periodically
be monitored using wells that adequately reflect changes resulting from such
operations.
The Priority Ranking Report (Everett, 1979), carried out during the first
year of this study, gave spoils the highest priority for monitoring among the
sources of potential pollution directly related to coal strip mining. Spoils
deposited below the water table received a higher priority than spoils above
the water table. Spoils above the water table are of concern if they are lo-
cated under a source of leaching fluid, e.g., a pond, stream, or irrigated
area.
IDENTIFY POTENTIAL POLLUTANTS
Sodium and alkaline spoil materials have the greatest potential for con-
tributing pollutants to groundwater. Overburden materials with high salt
concentrations left on the final graded spoils cause immediate revegetation
problems. In addition, saline spoils dressed with topsoil can cause problems
through saline seeps and by the upward migration of salts into the topsoil.
Unrecovered coal, parting material, refuse, and other waste materials buried
in the spoil can be major sources of pollutants.
Primary pollutants may include soluble salts, with sulfates of calcium,
magnesium, and sodium predominating. Most spoils also contain appreciable
quantities of calcium carbonate. Normally, very few readily soluble chlor-
ides, carbonates, or bicarbonates are present. Also, plant-available forms
of phosphorus are normally low in the spoils and overburden. Shales commonly
contain appreciable exchangeable ammonium-nitrogen when weathered. Nitrifying
1
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organisms are scarce at depths of about 8 to 10 meters because of lower soil
temperatures. Consequently, nitrate forms of nitrogen predominate in the
upper levels and ammonium-nitrogen predominates at the lower levels.
The spoils in the Gillette area are generally neutral to alkaline.
Therefore, heavy metal contaminants may not be a major problem. However,
coal wastes buried within the spoil can become sources of trace element pol-
lution depending upon the minerals contained in the coal.
Monitoring Needs
Knowledge is needed of the general chemical characteristics of the re-
graded spoil. Specifically, information is needed on the type, concentra-
tion, and distribution of elements and/or compounds that become sources of
groundwater pollution, particularly for those areas of regraded spoil in con-
tact with free underground water and/or whose leachate possibly could con-
tribute potential pollutants to the groundwater system.
Alternative Monitoring Approaches
It would be desirable to have records maintained of the location and
amount of spoils that are emplaced during the monitoring program. Also, the
distribution of materials that have a significant pollution potential, such
as the shale layers above the coal, could be monitored.
Maps could be compiled on a monthly basis indicating both the location
and elevations of spoils material in the reclaimed area. Gross volumes or
weights of material could be estimated. Records could be kept for all mate-
rials which receive special handling in the spoils, such as coaly wastes and
shale partings. Amounts and locations of these materials in the spoil could
be specified. A photographic record of the face of the spoils in the pit
could be maintained. Such a record could substantiate, for example, that
more consolidated formations are being selectively placed in the bottom of
the spoils.
The composition of materials which make up regraded spoils could be de-
termined. Random composite samples could be taken at points on a grid cover-
ing the entire spoil area. The spacing of the points on a second sampling
pass could be determined by the variability and toxicity of material encoun-
tered during presampling.
Alternatively, a priority sampling scheme could be employed. The objec-
tive would not be to characterize the entire area of spoil by one or more
chemical elements or compounds, but rather to delineate selected areas that
contain pollutants which, due to their location or toxicity in the regraded
materials, would have increased potential of newly introducing or raising
existing concentrations of pollutants in the groundwater system.
These areas could first be delineated on the basis of their relation to
existing or predicted water table elevations within the spoil materials. The
strata thus delineated could be sampled in two stages. Initially, samples
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could be taken at grid points of about 300 feet* apart. Samples could be
taken at each point throughout the entire depth of spoil at no less than
5-foot intervals. Sampling could be made at closer intervals if particularly
toxic materials are encountered. Hand-driven samplers can be used to depths
of about 10 feet with power equipment required for deeper sampling. The sub-
ject of spoils sampling in areas of potentially toxic material placement has
not been addressed by State regulations.
The frequency for sampling solids in the spoils is presently difficult
to determine. In part, this depends on the variability of materials encoun-
tered at any time in the pit, including overburden, partings, and coaly
wastes. Part of this variation will be known at the time of mining due to
the quality of coal desired and for purposes of reclamation. The frequency
of sampling could be related to this variability. During the first year,
monthly grab samples could be collected. After the first year, the frequency
could be adjusted based on past experience and the dynamic chemical charac-
teristics of the regraded spoils.
Spoil samples could be analyzed for pH, electrical conductivity, total
soluble salts, soluble cations, base saturation, sulfate, nitrate, total ni-
trogen, and total organic carbon. Tests could be run on the saturation ex-
tract for powdered samples. In addition, boron and fluoride levels could be
determined. The content and character of pyrite or other forms of iron sul-
fide largely control the potential acidity of water contacting spoils and
should be evaluated. The soluble calcium content of the spoils also exerts a
controlling influence on the pH.
Drever, Murphy, and Surdam (1977) discussed trace elements associated
with the Wyodak coal seam at the Black Thunder mine. For purposes of ground-
water quality monitoring, vanadium, manganese, nickel, copper, zinc, arsenic,
selenium, lead, barium, cadmium, chromium, iron, molybdenum, and silver could
receive priority due to their importance for water use and/or their probable
relative mobility in soil aquifer systems.
The organic chemical content of certain materials in the spoils could be
substantial. This is particularly true for coaly wastes and shales. A gross
indication of the composition could be obtained by determining the total car-
bon and total nitrogen content. If specific organic chemical constituents
are found in groundwater in the spoils, then solid materials in the spoils
could be sampled for such specific constituents at a later time.
The radiological content of the spoils could be periodically evaluated
in a gross manner by determining the uranium and thorium contents. Samples
could also be analyzed for alpha activity, beta activity, and radium-226
activity.
* See Appendix B for conversion to metric units. English units are generally
used in this report because of their current usage and familiarity in in-
dustry and the hydrology-related sciences. Certain units, expressed in
commonly used metric units (e.g., concentrations), are expressed in milli-
grams per liter or similar units.
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Preliminary Recommendations
All existing information concerning the location and nature of backfilled
spoil material should be obtained and arrangements should be made with the
mining company to receive ongoing information of this type. If such data are
not being gathered, backfilled areas would be mapped and photographed, includ-
ing items such as spoil location, elevation, and composition. These maps
would be updated frequently, possibly on a monthly basis.
The composition of spoil materials would be determined using a priority
sampling scheme, as discussed above. Sampling frequency would depend on the
variability of spoil material and the rate at which an area is backfilled.
Samples would be analyzed for the constituents discussed above.
Costs for this step would include: labor costs for gathering existing
information, mapping spoils, and collecting samples; operational costs for
mapping, sampling, and spoil analyses; and capital costs for sampling and
photographic supplies, and equipment. These costs are given in Table A-l.
DEFINE GROUNDWATER USAGE
The largest quantity of groundwater used by the coal strip mines comes
from pit discharge. Dust suppression is the primary use of this water.
Wells supply water for drinking, bathing, and cleanup. Irrigation of re-
graded spoils is not planned at present, but may be a possibility in the
future.
Monitoring Needs
The primary monitoring need will be to determine whether backfilled
areas are to be irrigated and, if so, what the irrigation requirements will
be in terms of water quality and quantity.
Alternative Monitoring Approaches
The present and anticipated future use of groundwater for reclamation
could be assessed through discussions with mine personnel. If the spoils are
to be irrigated, simple irrigation metering devices could be installed in the
supply lines. The volume of water needed for irrigation could be estimated
by assuming a consumptive use of 1 to 4 acre-feet of water per acre being
revegetated.
Preliminary Recommendations
The recommended preliminary approach is to determine whether spoils are
to be irrigated. No further monitoring would be planned until irrigation is
decided upon. The only cost for this approach would be labor for discussions
with mine personnel.
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DEFINE HYDROGEOLOGIC SITUATION
Most of the mines in the Powder River Basin have groundwater conditions be-
tween those of the Wyodak mine, where the pit (located below the water table)
will most probably become a lake, and the Kerr-McGee mine (reportedly located
above the water table) where the spoils will not become saturated. The in-
crease in volume when the overburden is spoiled is about 30 percent. Where
the spoils become saturated, the possibility arises that the spoils could be-
come manmade aquifers. Where the overburden is predominantly sandstone or
alluvium, the permeability of these aquifers will be high. Permeabilities
will be low where the overburden is shale and/or siltstone. In addition,
dragline-dumped spoils will have a greater permeability than scraper-dumped
spoils.
Monitoring Needs
There are two primary needs for spoil areas which may be reinvaded by
groundwater after mining: definition of the existing groundwater system
(i.e., depth of water table, piezometric surface, thickness of aquifer, di-
rection and rate of flow within the aquifer, and the permeability of aquifer
materials), and development of methods for predicting the rate of invasion of
groundwater into the recontoured spoil and the final height of the water
table.
Alternative Monitoring Approaches
Existing data could be gathered for any wells in the mine area. These
data may include: water-level measurements, pump test results, and litho-
logic or geophysical logs. Geologic data may also be available from test
holes or oil wells in the area.
Water-level monitoring could be initiated in existing wells to determine
the depth of water, recharge and discharge areas, and direction of flow.
Aquifer tests could be conducted in existing wells for determination of the
transmissivity and storage coefficient and possible vertical leakage.
If necessary, additional wells could be drilled to supplement existing
wells in the area. These could be pump-tested and included in the water-level
monitoring program. These holes could be geophysically logged for geologic
information and permeability tests could be conducted on samples from both
overburden and spoil material.
Models could be constructed or modified to help predict the behavior of
groundwater systems after the area is mined and reclaimed.
Preliminary Recommendations
Preliminary steps in defining the hydrogelogic situation would be to
evaluate all existing information. If necessary, pump-testing and water-level
monitoring would then be initiated. The need for additional wells and data
collection would then be determined.
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Costs for work with existing facilities would include: labor costs for
gathering and interpreting existing data, monitoring water levels, and con-
ducting pump tests; operational costs for supplies; and capital costs for
well sounders. These costs are given in Table A-l.
STUDY EXISTING GROUNDWATER QUALITY
Shallow groundwater quality can vary widely in Campbell County. Ground-
waters in the Wasatch Formation are usually of the calcium sulfate type and
have a range in TDS of 500 to 6000 ppm. pH values range from 7.7 to 8.1.
Trace element studies indicate that problems may exist with the following
elements: arsenic, cadmium, lead, selenium, and possibly uranium (Everett,
1979).
Coal seam waters have been found to change in quality from calcium sul-
fate to sodium bicarbonate as the water migrates downdip. Coal seam TDS
values range from 500 to 3500 ppm, and values for pH range from 6.9 to 8.2.
Trace elements of concern include, but are not limited to: arsenic, cadmium,
copper, lead, and selenium (Everett, 1979).
Monitoring Needs
An essential monitoring need is the establishment of baseline data con-
cerning the chemical quality of groundwater both in the vicinity of backfilled
spoils and on a regional basis.
Alternative Monitoring Approaches
Available water quality data could be obtained and examined. A water
sampling program could be initiated to characterize the current groundwater
quality in the vicinity of backfilled areas. Samples could be collected from
existing wells, wells constructed during the previous step for characteriza-
tion of the hydrogeologic situation, and additional wells drilled, as neces-
sary, in the spoil material itself. Alternative methods for sample collection
and analysis are described in the monitoring design for stockpiles in the ac-
tive mine sources report.
Preliminary Recommendations
The recommended approach is to obtain and evaluate existing water qual-
ity data. A water sampling program would then be initiated, if necessary,
using existing wells and any installed during the previous step. The first
five samples from each well would be analyzed extensively (including calcium,
magnesium, sodium, potassium, bicarbonate, chloride, sulfate, phosphate, sil-
ica, ammonia, nitrogen, nitrate-nitrogen, total nitrogen, iron, manganese,
zinc, copper, chromium, cadmium, arsenic, molybdenum, selenium, and uranium).
Parameters found to be in excess of recommended limits would be delineated.
Periodic field checks would then be conducted for such parameters as pH,
electrical conductivity, dissolved oxygen, nitrate, and chloride, with sam-
ples being collected for laboratory analysis when marked changes occur be-
tween field checks. Samples would be analyzed for major constituents and
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those trace constituents previously found to be in excess of recommended
1 imi ts.
Costs for this step would include: labor costs for examining existing
data and collecting samples, operational costs for sample analyses and sup-
plies, and capital costs for pumps or bailers, a field kit for determining
pH, chloride, and nitrate, and conductivity and dissolved oxygen meters.
EVALUATE INFILTRATION POTENTIAL
Infiltration is the combined process of the entrance of water at the
soil surface and its subsequent downward movement through the soil media. It
is affected both by the condition of the surface and the nature of the soil
material. A large portion of the spoil material at the Campbell County mine
sites is derived from shale and siltstone. Therefore, it is fine textured
(excluding large rock fragments) with a high clay fraction, often above 20
percent. Furthermore, the characteristic rapid decomposition of shale when
exposed to weathering releases salts which tend to inhibit flocculation and
the formation of soil structure. If the materials have an unchangeable so-
dium percentage greater than 15 (sodic), as they often do, they may form a
surface essentially impermeable to water.
Infiltration rates on spoil materials may vary from as high as 20 inches
per hour (alluvial material) to 0.2 inch per hour (shale material). An aver-
age infiltration of about 0.5 inch per hour is common on spoil with high shale
and clay components.
Regrading and surface treatment for reclamation (pits, furrows, berms,
etc.) create depressions for surface water retention and provide extended
periods of a steady supply of water at the soil surface that might sustain
infiltration for long periods. However, retention basins often become imper-
meable from the sealing effects of fine material washed in by surface runoff.
Their effective life is only a few years, under the best conditions. In areas
where underground fires occur, infiltration may be greatly influenced due to
cavitation and subsequent cracking and caving at the surface which can allow
the entry of free water. If the mining operation is efficient, these condi-
tions appear in small areas, are short-lived, and occur infrequently.
An important source of possible groundwater pollution from infiltrating
waters can occur beneath stream beds after they are mined and if stream chan-
nels are reconstructed across the spoil material. Creeks which are losing
streams in their natural state will probably also become reestablished as
such and will have a high potential for contributing significant amounts of
surface water to the groundwater system.
Monitoring Needs
Infiltration capacity is an important parameter in characterizing the
hydrologic behavior of spoil. Information on infiltration is needed to sup-
plement other data (e.g., precipitation, snowmelt, evaporation potential)
necessary to classify the potential of spoil materials to contribute pollu-
tants to the groundwater system.
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Alternative Monitoring Approaches
Infiltration capacity could be determined by (1) laboratory tests of
spoil permeability, (2) ring infiltrometers, or (3) sprinkler-type infiltrom-
eters. Laboratory permeability tests are of doubtful value because of the
disturbed nature of the samples, their small size, and the associated diffi-
culty of obtaining representative samples. Field infiltrometer tests can be
useful in comparing differences of magnitude between sites and are useful for
irrigation purposes where the supply of water at the soil surface is steady,
but they cannot be relied upon to give quantitative representation of actual
infiltration under natural rainfall or snowmelt.
The sprinkler-type infiltrometers are generally preferred over the ring
type. They more closely approximate natural rainfall (i.e., raindrops and
zero head), provide a measure of surface runoff potential, and, with some de-
vices, give estimates of erosion potential. They are also difficult to oper-
ate, require considerable auxiliary equipment, and are expensive. The ring
devices are very simple and provide a quick means of obtaining relative val-
ues of infiltration capacity for different sites.
Measurement sites could be chosen randomly or selected on the basis of
previous information. Ideally, sampling should be completely random or sys-
tematic with random starts; however, this would require an inordinate amount
of effort to characterize a large area. Interpretation would be complex be-
cause of the point-to-point variability. Stratification could help reduce
variability if an average were sought for the entire area.
Sites could be selected for infiltration studies on the basis of chemi-
cal and physical characteristics and the depth of spoil overlying the water
table, determined in Step 1 (Identify Potential Pollutants). For example, an
area of saline spoils might be given a higher priority than one of sodic
spoils (other factors being equal) because of a higher infiltration capacity.
Infiltration runs could be made at points within such areas which are judged
to be most representative of the general condition.
Sufficient samples could be taken to achieve a reasonable degree of pre-
cision; 10 percent of the mean final infiltration rate (fc) at the 95 percent
confidence level is desirable. For most spoil materials, the final rate is
obtained within 2 hours.
Infiltrometer data could be used with precipitation measurements and
historic records of precipitation to estimate the maximum probable infiltra-
tion under the prevailing climatic conditions at the mine site.
Preliminary Recommendations
Infiltration capacity would be determined using a simple ring infiltrom-
eter because of the economics and ease of obtaining data quickly from a large
number of sites. Sites would be selected on the basis of information gathered
in Step 1. Precipitation data would be obtained from existing records for
the area.
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Costs for this step include: labor costs for infiltration measurements
and data collection, and capital costs for ring infiltrometers. These costs
are given in Table A-l.
EVALUATE MOBILITY OF POLLUTANTS IN THE VADOSE ZONE
The mobility of water and the pollutants it might carry depends upon the
infiltration characteristics of the surface and the distribution size, and
composition of materials comprising the spoil. Spoils, despite the mixing
that occurs during overburden removal and subsequent regrading, are very non-
homogeneous. Vertical and areal variations are greater, in most cases, than
those of natural soil or geologic bodies. It is to be expected, particularly
if opportunities exist for free water to enter the surface, that temporarily
perched free water may develop in the soil where impermeable layers are formed
during the spoiling operation.
Most of the spoil material is composed of rocks with interspaces filled
with fine material. In removing and regrading the overburden, the spoil in-
creases in volume; swell factors of 20 to 30 percent are common. Permeabil-
ity for air and water is increased, but this is usually offset by the high
colloidal content of the spoil material. Sodic tendencies are common in
spoils; thus, subsurface piping may occur which would allow free water flow
within the spoil. Similarly, the burning of combustibles in the spoil also
creates opportunities for free water movement by creating voids and cracks.
Water movement in the vadose zone will occur as unsaturated, unsteady flow in
most of the spoil areas. However, where mining occurs in stream valleys, and
where the stream bed is redeveloped on the mine spoil, the development of
saturated flow is very likely because of the constant availability of water
at the surface and the high permeability of the alluvial spoil material.
Monitoring Needs
There is a need to monitor the quantity and quality of water moving
through the vadose zone of spoil to groundwater. Particular attention needs
to be given to the more critical sites; i.e., those sites with one or more of
the following characteristics: high infiltration capacities and/or high per-
meability at the surface, shallow depth of spoil above the water table, and
concentrations of potential pollutants within the spoil.
Alternative Monitoring Approaches
A survey could be conducted and maps developed of the regraded spoil to
delineate areas by their potential for contributing water and/or pollutants
to groundwater. The survey would require information on: hydrologic charac-
teristics (high, medium, and low infiltration characteristics), topographic
position (swales, depressions, etc.), predominant types of material (alluvium,
shale, siltstone, sandstone, etc.), conditions of the material (sodic, alka-
line, normal, etc.), depth to existing or predicted future water tables, and
anomalies (excessive amounts of partings, unrecovered coal, and/or wastes,
and the presence of underground combustion).
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Thus, in addition to topography and spoil-type mapping, the maps would
include: delineations of free water surfaces (presently existing on future
possibilities), the results of soil sampling and analyses, infiltration char-
acteristics, and the existence and depth of water table.
Using overlays or computer graphics, the critical areas of spoil could
be delineated and prioritized on the basis of their potential for contribut-
ing to groundwater problems. For example, an area with spoil material that
has a high infiltration capacity, which lies above a shallow water table in
an area where free water concentrates on the surface, and whose spoil mate-
rial contains potential pollutants, would be given the highest priority and
would warrant the most intensive monitoring.
Since the greatest opportunity for the movement of water and the poten-
tial pollutants it might carry to the groundwater system will occur as unsat-
urated, unsteady flow, it will be necessary both to sample changes in water
content and measure the pressure changes with time and depth.
The three most common means of measuring moisture changes are: gravi-
metric, electrical resistance, and neutron scattering. Changes in pressure
(negative head) can be measured with pressure plates, tensiometers, or psy-
chrometers.
For measuring moisture content, electrical resistance methods are diffi-
cult, if not impossible, to quantify with confidence. Gravimetric methods
give good results but eventually destroy the sampling site and are time con-
suming and labor intensive. Neutron probes and loggers also present techni-
cal and logistical problems, but are a satisfactory compromise. Negative
pressures in soils can be measured with pressure plates, but they are diffi-
cult to install and interfere with flow. Tensiometers, although simple, re-
quire diligent maintenance and will not give reliable results below moisture
contents corresponding to about 3/4 of a bar pressure. At lower moisture
contents, soil psychrometers could be used instead of, or to augment, the
tensiometers. These devices require skill and experience to interpret accur-
ately. They are ineffective in wet soils, but can give good results at lower
moisture contents.
It is also possible, in theory, to simulate moisture flux in soil media
using field and laboratory determined values of the necessary parameters.
However, models have been developed to date only for homogeneous and simple
layered systems and have little application to mine spoils because of the in-
homogeneities that exist in most spoils and the difficulty of obtaining the
parameters required by the models.
Preliminary Recommendations
Based on the considerations above, neutron probe access wells are recom-
mended on critical sites extending through the spoil well into the existing
or predicted future saturated zones. Tensiometers would be installed at three
depths above the capillary fringe region of the water table at integrals no
more than 2 feet apart adjacent to the access wells. Since moisture flow
10
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will be negligible at pressures less than 1 bar, psychrometers will not be
necessary.
The sampling should be conducted in two stages. Initially, all sites
delineated in the survey should be instrumented with an access tube extending
through the entire depth of spoil. Monitoring throughout the first year on a
monthly basis will allow the most obvious nonproblem sites to be eliminated
from subsequent monitoring. Questionable sites should be monitored for as
long a period as necessary to show that they may present problems or that
they may also be eliminated. It is expected that the final number of problem
areas will not be large. Significant flow of water from the low precipita-
tion in the area will only occur in the most permeable and/or shallow mate-
rials. Nevertheless, monitoring should be intensified on those sites which
exhibit a high potential for contributing to the groundwater system.
It is recommended that additional access tubes be installed on the cri-
tical sites in a second stage. It is assumed that where problems exist,
moisture contents will be high. Therefore, tensiometers would be installed
adjacent to the access tubes to measure pressure differences for the deter-
mination of flow volumes.
The number of installations to be made would depend upon cost, the vari-
ability encountered, and the desired precision. Standard sampling analyses
which incorporate these variables would be used to establish the sampling
intensity.
Costs for this step include: labor costs for installation of access
wells and tensiometers and for sampling, operational costs for installation,
and capital costs for wells, tensiometers, and a neutron logger. These costs
are given in Table A-l.
EVALUATE ATTENUATION OF POLLUTANTS IN THE SATURATED ZONE
There are two types of saturated zone monitoring. One type could be
done while pit dewatering is still in progress adjacent to a specific area of
spoils. In this case, pit water, water from wells tapping nearby coal and
overburden, and monitor wells in the spoils could be sampled. The second
type is for spoils beyond the influence of pit dewatering. In this case,
monitoring of pit discharge is unnecessary. However, monitoring would still
be necessary for groundwater in materials adjacent to the spoils.
Monitoring Needs
Monitoring needs for the saturated zone include: aquifer tests on sat-
urated spoils, determination of the extent of saturated spoils, determination
of groundwater flow direction in the spoils, and determination of the quality
of groundwater in the spoils, including trace elements, organic chemical con-
stituents, and radiological constituents. Wells in the Wasatch Formation,
coal seam, and underlying Fort Union Formation are needed in close proximity
to the spoils. Groundwater conditions in undisturbed materials adjacent to
the spoils must be understood in order to interpret the results of monitoring
groundwater in the spoils.
11
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Alternative Monitoring Approaches
The aquifer characteristics for, and water levels in, the emplaced spoils
need to be determined. Also, the site-specific hydrgeologic framework for
undisturbed materials adjacent to the spoils must be developed, including
subsurface geology, water levels, aquifer characteristics, and groundwater
quality. Most of this information could be gathered in the course of gather-
ing groundwater quality data through monitor well construction.
A number of new wells could be drilled in the spoils after emplacement.
These would be constructed while pit dewatering is still occurring nearby.
These wells would be 14-inch-diameter holes equipped with 8-inch-diameter
casing to allow proper pump testing. PVC pipe would be used for casing and
the new well would be packed with gravel of known composition. The casing
would be perforated opposite the zone expected to eventually be saturated
when pit dewatering ceases in nearby areas. An annular seal would be placed
opposite the upper 10 to 20 feet of the well. The wells would be properly
developed upon completion to remove drilling mud or other foreign material.
The top of the casing would extend several feet above the ground surface and
a locking cap installed. Barriers would be installed to prevent destruction.
Wells in the spoils could be pump tested to determine aquifer character-
istics once water levels have recovered from nearby pit dewatering. It would
be advisable to conduct a test with the maximum possible saturated thickness.
In order to interpret the results of monitoring groundwater in saturated
spoils, additional monitoring is necessary for groundwater in materials adja-
cent to the spoils. This includes Wasatch Formation overburden, coal, scoria,
alluvium, and Fort Union Formation underburden, depending on the particular
area. Existing monitor wells could provide some indication of regional
groundwater conditions in the coal seam and overburden. However, regional
groundwater conditions are poorly known for alluvium and the Fort Union For-
mation beneath the coal. In the early stages of mining, when pit discharge
i's occurring near emplaced spoils, pit discharge itself could be monitored,
as well as additional wells in native materials adjacent to the spoils, par-
ticularly in an upgradient direction. This would require a minimum of sev-
eral monitoring wells in the coal, several additional monitor wells in the
overburden, and possible additional wells in the alluvium and underburden.
Both solid and liquid samples could be collected frbm the saturated
zone. Some solid material could also be sampled during emplacement. To
allow interpretation of the results of groundwater quality monitoring, solids
penetrated by the monitor well could be sampled. Since some of the materials
in the spoils are well consolidated, the optimal method of drilling is uncer-
tain. However, drill cuttings could be collected in any case. Sampling of
solids may provide invaluable data to evaluate factors such as trace metal
migration in groundwater. Additional holes could be drilled into spoils
periodically near the monitor wells to allow sampling and analysis of solids
to correlate with the results of groundwater quality sampling.
Once the optimal pumping duration has been determined for water sample
collection from wells, samples could be" collected monthly for the first year.
12
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The results of the first year could be used to determine the proper sampling
frequency for the duration of the monitoring program. Climatic factors, such
as liquid and solid precipitation events, should be considered in determining
the exact date of collection of each sample. The pump tests in spoils would
allow ample opportunity to collect samples for chemical analyses over several
days or weeks. For pit discharge, results may be available from existing
monitoring programs for that source. Pit discharge is monitored at the point
of discharge to surface water for a few parameters. Grab samples could be
collected on a weekly basis for 1 year and the frequency adjusted thereafter.
However, the results of pit discharge sampling would be difficult to interpret
with regard to specific pollutant sources, such as the spoils, unless a com-
plete monitoring program for the sources of pit discharge was also in effect.
Solids beneath the water table could be analyzed for similar determina-
tions specified for spoils as discussed earlier under the step, Identify Po-
tential Pollutants.
For water, the major inorganic chemical constituents could be deter-
mined, in addition to pH, total dissolved solids (residue (180°C), and elec-
trical conductivity. Such determinations allow comparison of cation-am"on
sums, total dissolved solids versus electrical conductivity, and calculated
total dissolved solids versus residue. Occasional samples could have total
dissolved solids (ignition 365°C) determined. Boron, fluoride, and various
nitrogen forms could also be determined on occasion. An exhaustive suite of
trace elements could be determined on at least one sample of water taken from
each well near the end of the pump test. This would aid in selecting deter-
minations to be made on a routine basis. Iron, manganese, arsenic, selenium,
cadmium, chromium, lead, molybdenum, and vanadium could be determined fre-
quently. Also, the results of the pollutant-source sampling program could be
used to choose the trace elements of importance in groundwater quality
monitoring.
The gross inorganic chemical composition of groundwater could be deter-
mined through analysis of dissolved carbon. More detailed determinations
could be recommended after results have been obtained from the gross deter-
minations. Uranium and thorium content and gross alpha activity, gross beta
activity, and radium-226 activity could be determined on several water sam-
ples from each well and the pit discharge early in the program to provide an
indication of the radiological composition of groundwater in the spoils.
A similar procedure could be used for analyses of water samples col-
lected from monitor wells in undisturbed materials near the spoils.
Preliminary Recomendations
It is estimated that each year from 50 to 100 acres of spoils at each
mine will be reclaimed. Annually, about six monitor wells should be con-
structed in the spoils. These wells would be an average of 100 feet deep and
equipped wth 8-inch-diameter PVC casing. Wells installed during the first
year would be pump tested for 1 week. This would require 7 days each for
three individuals per well. Approximately three water samples would be ana-
lyzed from each pump test. An average of three samples of solid materials
13
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penetrated by the monitor wells would be analyzed for each well. Samples of
pit water could be obtained from the sump pump at the bottom of the pit.
A monthly sampling frequency based upon average groundwater flow and
discharge rates is initially recommended for water from monitor wells and pit
discharge. If the flow rates and the sample parameter values vary widely,
increased sampling may be required. A portable submersible pump, generator,
tripod, winch, pump column, discharge line, and electric cable would be ne-
cessary. It is estimated that three wells could be sampled in 1 day and two
individuals would be required. Sampling of the pit discharge would involve
no extra time.
Spoils below the water table can be analyzed for the same constituents
specified for solids under Identify Potential Pollutants.
For water samples, the following should be determined routinely:
Calcium Boron Magnesium Fluoride
Sodium Total nitrogen Potassium Silica
Carbonate Iron Bicarbonate Manganese
Sulfate Arsenic Chloride Selenium
Nitrate Lead pH Cadmium
Total dissolved Chromium Electrical Dissolved organic
solids (residue conductivity carbon
at 180°C)
Several samples collected early in the program, such as during pump
tests, should be analyzed for:
Total dissolved Antimony Iodide Titanium
solids (ignition
at 365°C) Bromide Rubidium Vanadium
Strontium Nickel Aluminum Copper
Cobalt Zinc Cesium Barium
Uranium Molybdenum Thorium Silver
Alpha activity Tungsten Beta activity Radium-226
activity
Costs for this step would include: labor costs for drilling supervision,
sampling, and interpretation of results; operational costs for drilling, mis-
cellaneous sampling equipment, and analyses of water and solid samples; and
capital costs for wells, pumps, etc. These costs are given in Table A-l.
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SECTION 2
MONITORING DESIGN FOR RECLAMATION AIDS
INTRODUCTION
According to Tisdale and Nelson (1975), 20 elements have been found to
be essential to the growth of plants. Not all are required by all plants,
but all are necessary to some plants. The elements required by most plants
are carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, boron, iron, man-
ganese, copper, zinc, molybdenum, chlorine, cobalt, vanadium, sodium, sili-
con, and potassium.
The first three, with nitrogen, phosphorus and sulfur, constitute a
plant's living matter or protoplasm. Elements other than carbon, hydrogen,
and oxygen are termed mineral nutrients and are obtained by plants from the
soil. The elements nitrogen, phosphorus, and potassium have been classed as
major nutrients; calcium, magnesium, and sulfur as secondary elements; and
the remaining mineral nutrients as microelements.
It should be noted that these classifications are arbitrary and are pro-
bably based on the quantities of mineral elements required in the majority of
fertilizer programs. As a very general rule, the major elements are needed
in the largest amounts and the microelements in the smallest.
Selection of the kinds and amounts of soil fertility treatments depend
upon: the crop and its nutrient requirements, the ability of a given soil to
supply those nutrients, the climatic factors that affect crop growth and fer-
tility response, management and cultural practices, and the presence or ab-
sence of damaging chemicals or pathogens. In the evaluation of the pollution
potential of fertilizers applied to reclaimed coal strip mine lands, all of
the aforementioned factors, excepting the last item, will be essential consid-
erations in the assessment of the pollution potential of applied fertilizers.
Economically optimizing the ability of a given soil or overburden mate-
rial to supply those essential nutrients required for a given crop within the
limits of the other factors is the goal of any fertilizing recommendation,
and it is the purpose of this section to evaluate the effects of this goal on
the groundwater quality of a coal strip mine.
IDENTIFY POTENTIAL POLLUTANTS
Fertilizer sources most likely to affect the quality of water within
reclaimed areas include the major mineral nutrients nitrogen and phosphorus
15
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and certain micronutrients, if applied in relatively large amounts. Ammonium
nitrate is entirely soluble in water when used as a fertilizer. Nitrate-
nitrogen (N03-N) is immediately available to plants, as this is the form that
plants primarily absorb, although some plants have ability to absorb small
amounts of ammonia-nitrogen (NH3~N) by direct cation exchange.
Because ammonia and nitrate-nitrogen have the ability to move up and
down in the soil solution, both should be included in the monitoring effort.
The cationic nature of Nh^-N permits its adsorption and retention by soil
colloidal material if the cation exchange capacity of the soil is sufficiently
high; otherwise, it will be removed in percolating water. Nitrate is highly
subject to leaching, as it is completely mobile in soils. Hence, its inclu-
sion in the monitoring effort is highly justified.
Because the phosphate ion is almost immobile in soil, phosphorus moves
very slowly from the point of placement. Also, the activity of phosphorus is
lower in alkaline or calcareous soils due to the high Ca+2 activity, the
large amount of finely divided calcium carbonate, and the large amount of
calcium-saturated clay, all of which contribute to the precipitation of phos-
phate on solid phase calcium carbonate. Therefore, phosphorus is a doubtful
source of groundwater contamination and should not be included in the moni-
toring effort.
Monitoring Needs
Due to lack of existing data, nutrients being applied to reclaimed areas
must be delineated.
Alternative Monitoring Approaches
Pollutant-specific information on monitoring activities by the coal com-
pany relating to fertilizer application on reclaimed areas could be collected.
For example, any existing water quality data may be requested together with
information on fertilizer application. Alternatively, the areas receiving
fertilizer application could be clearly delineated, along with the nature of
the application and its rate.
Water samples for characterizing pollutants associated with fertilizer
application could be obtained from surface waters adjacent to reclaimed
areas. Samples could be collected before and after fertilizer has been ap-
plied, with increases in the concentration of particular constituents being
noted.
These alternative methods are possible for analyzing surface water sam-
ples. First, all samples may be submitted for complete analyses, including:
the major inorganics (nitrate-nitrogen, ammonia-nitrogen, calcium, magnesium,
sodium, potassium, bicarbonate, chloride, sulfate, phosphate, silica, total
nitrogen, pH, and electrical conductivity) and trace constituents (iron,
manganese, zinc, copper, cadmium, chromium, arsenic, molybdenum, vanadium,
and selenium).
16
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A second technique is to completely analyze the first few water samples
collected during the program. Subsequently, those constituents known to be
applied as fertilizer would continue to be analyzed, whereas those not ap-
plied as fertilizer could be excluded from further analyses.
A third method is to analyze only for those constituents known to be
applied as fertilizers, and exclude any fertilizer constituents found to be
present in low concentrations from further analyses.
Selecting a sampling frequency to characterize the water-borne pollu-
tants in a source, such as applied fertilizer, is generally dependent upon
the concentration and rate at which the fertilizer is applied. One method is
to sample frequently (e.g., every few days or weekly) until time trends in
the quality of the source are characterized. Subsequently, samples would be
obtained by periodic sampling (e.g., weekly or monthly). An increase in sam-
pling frequency may be warranted by unusual circumstances. For example, a
spill of fertilizer on the watershed area draining into surface water could
justify an increase in sampling frequency.
Preliminary Recommendations
All areas receiving fertilizer application should be delineated, along
with the nature of the application and its rate. Surface water in the area
should be sampled before and after fertilizer application to characterize the
present water quality and quantity trends. Initial water samples would be
analyzed completely, with later samples analyzed only for those constituents
present in the fertilizer applied to the reclaimed areas.
Costs include: labor costs for data collection and sampling, and opera-
tional costs for analyses and miscellaneous sampling equipment. These costs
are given in Table A-2.
DEFINE GROUNDWATER USAGE
Irrigation of reclaimed spoils is not planned at any of the mines at
present; however, it may be a possibility in the future.
Monitoring Needs
Primary data required by monitoring pertain to determining whether re-
claimed areas will be irrigated and, if so, what the irrigation requirements
will be in terms of water quality and quantity.
Alternative Monitoring Approaches
Anticipated use of groundwater for irrigation of reclaimed land could be
assessed through discussions with mine personnel. If irrigation is being
used, the quantity of water could be monitored with irrigation metering de-
vices installed in the supply lines. The volume of water needed for irriga-
tion could also be estimated by assuming a consumptive use of 1 to 4 acre-feet
of water per acre being revegetated.
17
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Preliminary Recommendations
The recommended preliminary approach is to determine whether spoils are
to be irrigated. No further monitoring would be planned until irrigation is
decided upon. The only cost for this approach would be labor for discussions
with mine personnel.
DEFINE HYDROGEOL06IC SITUATION
Studies to evaluate the hydrogeology of a pollutant source area require
determining: aquifer locations, depths, and area! extent; transmissivities
of aquifers; areal distribution to potentiometric surfaces; depths to ground-
water; areas and distribution of natural groundwater recharge; areas and mag-
nitudes of natural groundwater discharge; and directions and velocities of
groundwater flow (Todd et al., 1976). These items relate to saturated ground-
water flow (i.e., in the zone of saturation). Data of the hydrogeologic
properties of the vadose zone are also important in estimating pollutant mo-
bility. Such properties include determining infiltration characteristics,
the presence of potential perching layers, water content changes of sediments
during deep percolation, and flow rates of water.
Characterization of the above items is of particular importance for the
area encompasssing a specific source. That is, the hydrogeology should be
clearly understood in a source-specific sense.
Monitoring Needs
The following data gaps exist relative to the areas encompassing ferti-
lizer applications: vadose zone properties (geology, lithology, etc.), and
saturated zone properties, including locations of aquifers and associated
geology and hydraulic head distributions, transmissivities (including aniso-
tropic T) and storage coefficients of aquifers, and direction and velocities
of groundwater flow.
Alternative Monitoring Approaches
An initial procedure could be to conjecture as to the nature of the re-
claimed soil and overburden materials utilizing mine plans. This could be
followed up by field reconnaissance.
Alternatively, field tests could be commenced to determine the physical
properties of the reclaimed area spoil. These tests are an integral part of
the monitoring approach in that the hydrogeologic situation will be highly,
modified.
Physical characteristics (including texture, consistency, depth, struc-
ture, colloidal content, and saturation percentage) of spoil and topsoil used
for dressing could be determined.
Once the spoil has been physically characterized, tensiometers could be
installed into the soil and spoil material composing the modified hydrogeol-
ogy. Individual units could terminate at successive depths, e.g., 3 inches,
18
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6 inches, 12 inches, 24 inches, 36 inches, and 60 inches below the reclaimed
surface. . Tensiometer data could be used with water content data, obtained by
sampling by neutron logging, to estimate the hydraulic conductivity and flux.
Alternatively, access wells could be installed to the depth of the water
table and logged routinely with a neutron moisture probe for evidence of seep-
age to the water table.
Dry drilling methods could be employed to obtain soil and spoil samples.
A hollow stem auger is capable of providing the most useful background water
quality data in the vadose zone. However, unconsolidated materials may pre-
sent some problems.
Analyses of collected soil samples could include the measurement of pH,
SAR, calcium, magnesium, chloride, alkalinity, CEC, chemical oxygen demand,
and analysis for the ammonium and nitrate ions. These analyses would be com-
pleted prior to any fertilizer application. These analyses would serve to
characterize the soil and spoils of the area under consideration prior to
fertilizer application, with subsequent analyses restricted to the measure-
ment of pH, ammonium, and nitrate.
If a saturated zone is detected in existing wells in the reclaimed area,
or while obtaining solid samples, sampling holes could be completed as wells
and pump tests conducted.
Preliminary Recommendations
The following approach is recommended initially for hydrogeological
studies:
• Collect available data on the modified hydrogeology of reclaimed
areas
• Conjecture as to the nature of soil and overburden materials by
field reconnaissance.
Costs for this step include labor for reconnaissance field study and
field transportation. Costs for these items are given in Table A-2. Data
compilation, review, and testing are covered in defining the hydrogeologic
situation for regraded mine spoils described in Section 1.
STUDY EXISTING GROUNDWATER QUALITY
The general purpose of determining groundwater quality in the vicinity
of a source, such as applied fertilizers, is to characterize the impact of
pollutant movement on the indigenous quality. Two types of information are
required: background quality and current quality. Activities during this
step will overlap related steps involving characterizing the hydrogeologic
situation and determining the attenuation of pollutants in the zone of
saturation.
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Monitoring Needs
Data deficiencies exist in the following: current areal distribution of
groundwater quality in reclaimed areas receiving fertilizer and time trends
in the quality of groundwater beneath reclaimed areas.
Alternative Monitoring Approaches
If any wells exist in reclaimed areas, information, including depth of
well, location of perforations and water quality data, could be collected.
A water sampling program could be initiated to characterize the current
groundwater quality in the vicinity of the source. Methods include: sampling
from existing monitor wells in the reclaimed area, installation of supple-
mental wells, and a combination of the two. Monitor wells required by the
second method would only be constructed following assessment of a serious
pollution threat to the existing groundwater quality.
Water samples could be obtained by a variety of alternative techniques:
submersible pump, hand bailing, air-lift pump, etc. The submersible pump
permits redevelopment of the well and rapid sample collection. The latter
feature is desirable in light of the recommendation that at least five casing
volumes be removed prior to sample collection (Mooji and Rovers, 1976). Hand
bailing is a viable method in small-dianeter casing. Air-lift pumps intro-
duce air into the sample, causing changes in unstable constituents, such as
pH, DO, and alkalinity.
Three possible alternatives for water sample analyses are as follows:
Samples could be completely analyzed for constituents listed above (Identify
Potential Pollutants) in each category, major inorganics, and trace consti-
tuents. Alternatively, the first few water samples could be examined com-
pletely. Once the principal constituents are identified (primarily those
occurring in greater-than-permissible levels), subsequent analyses would be
for these constituents only. Note that this approach would be used only for
those inorganics that are not applied as fertilizer. The ammonium-nitrogen
and nitrate-nitrogen concentrations would be determined for each sample.
Primary Recommendations
The preliminary monitoring approach would be to collect all available
water quality data from wells in the reclaimed area. Groundwater samples
would then be collected from existing wells and supplemental wells constructed
to evaluate specific pollutant sources. A submersible pump would be used for
sample collection, and each well would be pumped for a sufficient period of
time to remove five casing volumes before sampling.
Initial water samples would be analyzed completely; while subsquent
analyses would be only for those constituents found to occur in greater-
than-permissible concentrations. Ammonium-nitrogen and nitrate-nitrogen
concentrations would be determined for each sample.
20
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Samples would be taken on a weekly basis until time trends in quality
are established. Thereafter, samples would be obtained on a bimonthly basis.
Unusual events may necessitate a greater sampling frequency.
Costs for this step include: labor costs for collecting and interpret-
ing existing water quality data and taking samples, operational costs for
sample analyses, and capital costs for submersible pumps, etc. These data
have been compiled for defining existing groundwater quality in the prelimi-
nary monitoring design for regraded spoils (Table A-l) and will not accrue
additional costs here.
EVALUATE INFILTRATION POTENTIAL
The purpose of determining the infiltration potential of a source is to
quantify the volume of water and associated pollutants moving to the underly-
ing saturated zone.
The priority ranking report (Everett, 1979) indicates that the natural
material used for surface dressing is expected to have a higher infiltration
than the spoil material, but lower, after settlement, than the structured
natural soils.
Monitoring Needs
The primary information needed by monitoring is the quantity of water
which infiltrates the fertilized spoil surface.
Alternative Monitoring Approaches
Infiltration capacity could be determined by laboratory tests of spoil
permeability, ring inf iltrometers, or sprinkler-type infiltrometers. These
are discussed in the monitoring design for infiltration capacity of spoils in
Section 1.
Preliminary Recommendations
Infiltration capacity would be determined using a simple ring infiltrom-
eter. Sites would be selected on the basis of information collected during
identification of potential pollutants for spoils.
Costs for this step include: labor costs for infiltration measurements
and data collection and capital costs for ring infiltrometers. These costs
would be attributed to the preliminary monitoring design for regraded mine
spoils monitoring step, Evaluate Infiltration Potential (Table A-l).
EVALUATE MOBILITY OF POLLUTANTS IN THE VADOSE ZONE
The general purpose of this step is to estimate or measure the movement
of pollutants in the vadose zone underlying a source or sources. Pollutants
associated with fertilizers will be specified upon implementation of the
step, Identify Potential Pollutants. Similarly, the potential for pollutants
21
-------
to move into the vadose zone from the point of application will be determined
during the above step (Evaluate Infiltration Potential).
As previously mentioned, ammonium nitrate is completely soluble if suf-
ficient moisture exists to dissolve it. Once dissolved, the two types of
nitrogen salt which compose this fertilizer have the ability to move up and
down in the soil solution.
Tisdale and Nelson (1975) discussed the retention of nitrate-nitrogen in
soil.
Once ammonia is nitrified, it is subject to leaching. Nitrate-nitrogen
is completely mobile in soils and within limits moves largely with the soil
water. Under conditions of excessive rain, it is leached out of the upper
horizons of the soil. During extremely dry weather and when capillary move-
ment of water is possible, there is an upward movement with the upward move-
ment of the water. Under such conditions, nitrates will accumulate in the
upper horizons of the soil or even on the soil surface.
Figure 1 illustrates the pattern of nitrate distribution in some columns
of soils which differed in their particle-size distribution. The percentage
of large pore space and the amount of coarse sand decreased from sample A to
sample H, although the total pore space remained relatively constant (Tisdale
and Nelson, 1975).
o.
UJ
Q
0|-
28 -
56 -
84
112
S:
£y = 632
1
i
>*
\
1
s
l-»
I
Y = MEAf
r OFN
- Y = 563
1 1
I 28
z
I 56
84
y = 341
J
- Y =329
I
- X = 230
I
- Y = 155
I
1
1
20 0 20 0 20 0 20 40 60
NITRATE AS PERCENT OF TOTAL EXTRACTED
80
Figure 1. Distribution of nitrates through columns of
coarse-textured soils after adding 3.29 cm
of water (after Tisdale and Nelson, 1975).
22
-------
TABLE 1. PROCESSES WHICH MAY CONTROL AMOUNTS OF CERTAIN
CONSTITUENTS IN SUBSURFACE WATERS CONTAMINATED
BY WASTE DISPOSAL3
Physical
Geochemical
Biochemical
Constituent
Cl'.Br"
NO 3"
S0i«2~
HC03I
PO1*
Na+
K+
NH Q.
i— £
1Z 8
(x)
(x)
X
X
(x)
(x)
X
X
X
X
X
.C
.)_)
o^
U C
•r- CU
C i.
0 -P
l— ( tO
(x)
(x)
X
(x)
(x)
(x)
X
X
X
X
(x)
0)
to
(O
_Q
1
-o
•^
o
(x)
X
X
X
X
X
X
X
1
c c:
o o
•P +^
ta
^>
•^
Q.
0 C
s- 'o
D-
a. CL
S- i.
0 O
(/) IO
T3 O)
(d
^*>'^
rO Q.
U 10
CU CU
0 S-
X
(x)
X
X
X
X
X
(/)
•r—
in
CU
.c
i— •«->
i— C
CU >>
c_5 «n
X
X
X
X
X
NOTE: ( ) denote minor controls.
a
from Langmuir, 1972.
Monitoring Needs
Data gaps exist in knowledge of the factors tending to attenuate pollu-
tants within the vadose zone (i.e., dilution, filtration, sorption, chemical
precipitation, buffering, oxidation reduction, volatilization, and biological
degradation and assimilation), and in field data on transformations in water-
borne pollutants during flow in the vadose zone.
Alternative Monitoring Approaches
The potential attenuation of pollutants in the vadose zone may be de-
picted by constructing a matrix (table) comprising attenuating factors (rows)
versus specific pollutants (columns). An example (Table 1) of such a matrix
has been prepared by Langmuir (1972). Each location in the matrix would
specify the relative potential of a factor (e.g., sorption) to attenuate a
23
-------
specific pollutannt (NH.). Each position in the table may be filled in by
subjective evaluation of on the basis of actual measurement. Subjective
evaluation would involve examining available data and estimating the effect
on the mobility of a specific pollutant. Alternatively, actual values from
attenuating factors may be obtained from field measurements. For example,
spoil samples obtained in a previous step may provide analytical data on pol-
lutant mobility.
A second method is to use instruments installed during a previous moni-
toring step to determine the water (and pollutant) movement in the vadose
zone. These instruments included access wells (neutron moisture logging) and
tensiometers.
Field activities could be initiated to monitor the actual movement of
pollutants in the vadose zone. Alternative methods include: collecting
drill or auger samples for laboratory analysis and installing suction-cup
lysimeters.
Collection of samples of vadose zone sediments would entail using hand
or power augers, or core samplers. Depending on physical composition of the
spoil underlying the fertilized areas, hand-augered samples could be obtained
to a depth of about 10 feet. If deeper samples were required, power equip-
ment would be needed.
Suction-cup lysimeters could be installed in selected portions of the
vadose zone and within the fertilized areas at depths corresponding to ten-
siometer locations. Collection bottles and the vacuum supply would be lo-
cated in buried shelters, and vacuum and discharge lines from the suction-cup
lysimeter and tensiometer units would be positioned within conduit. During
sampling, vacuum would be applied to the samplers equivalent to water content
pressure in tensiometers. Note, suction-cup lysimeters become inoperable at
soil water pressures less than -0.8 atmosphere.
Water samples collected from suction-cup lysimeters could be analyzed
completely or partially. Ideally, a complete analysis includes the major
inorganics and trace constituents listed under Identify Potential Pollutants.
Upon examination of the results of complete analysis, it may be opted to ana-
lyze subsequent samples only for those constituents found present in greater-
than-permissible concentrations, and for those constituents present in applied
fertilizer.
Solid samples could be used to obtain saturated extracts via techniques
in methods of soil analysis (Black, 1965).
Sampling frequency for suction-cup lysimeters depends on the water pres-
sure within the surrounding porous matrix. Thus, if the system is very dry,
water will enter the samplers at a very slow rate. A week or more may be re-
quired before a sufficient sample is available for analysis. In the extreme
case, the samplers may become inoperable (i.e., when water pressure is less
than -0.8 atmosphere). In this case, samples may become available only once
or twice a year. Sampling frequency cannot be explicitly determined until
24
-------
field units are installed and operating. For a wet system, it may be desir-
able to collect samples on a frequent (e.g., weekly) basis until quality
trends are established. Later, samples could be obtained once a month.
Solid samples could be collected at a variety of frequencies, e.g.,
monthly, bimonthly, semi annually, or annually.
Preliminary Recommendations
The preliminary monitoring program would include constructing a matrix
of attenuating factors versus specific pollutants using available data when
possible, supplemented with intuition. Water movement in the vadose zone
underlying fertilized areas would be determined using facilities installed
during the step, Define Hydrogeologic Situation. A few suction-cup lysime-
ters would be installed at depths corresponding to tensiometer locations,
with samples analyzed as discussed above. Samples would be collected when-
ever possible during very dry conditions. For wet conditions, samples would
be taken more frequently until quality trends are established. Thereafter,
samples would be analyzed once a month.
Costs for this step include labor costs for constructing an attenuation
factor versus pollutant matrix and interpreting results, installing suction-
cup lysimeters, and collecting samples; operational costs for analyses; and
capital costs for the suction-cup lysimeters. These costs are given in Table
A-2.
EVALUATE ATTENUATION OF POLLUTANTS IN THE SATURATED ZONE
The general purpose of this step is to estimate or measure the attenua-
tion of source pollutants during flow in the zone of saturation. Obviously,
the pollutants of concern will be those which have not been completely atten-
uated during flow through the vadose zone. As pointed out by Todd et al.
(1976), the principal processes involved in attenuating pollutants in the
zone of saturation include physical-chemical reactions or dilution. For
pollutants in a source such as fertilizer, physical-chemical processes are
sorption, precipitation, volatilization, oxidation-reduction reactions, etc.
Dilution is effected by hydrodynamic dispersion resulting from such effects
as convection diffusion, and flow tortuosity.
Monitoring Needs
Information gaps currently exist in predicting the effect of physical-
chemical reactions and dilution on pollutant mobility within aquifers under-
lying fertilized aeas.
Alternative Monitoring Approaches
The relative effect of various physical-chemical mechanisms for atten-
uating pollutants within the saturated zone could be estimated by constructing
a matrix, similar to that for the vadose zone. That is, a table would be pre-
pared consisting of attenuating mechanisms (rows) versus pollutants (columns).
Attenuating mechanisms would consist of the following: physical-chemical
25
-------
factors, i.e., sorption, precipitation, volatilization, oxidation-reduction
(Eh), decay, and dilution. When completed, the table would show in a mixed
qualitative-quantitative sense the pollutants which should be monitored.
Completion of the matrix for the physical-chemical items requires speci-
fic information on exchange capacity of aquifer materials, on the Eh and pH
of groundwater, as well as on the specific pollutants entering the zone of
saturation. Many of the physical-chemical parameters could be quantified
from analysis of drill cuttings obtained during well construction and from
field analysis of Eh and pH. Identification of pollutants must await results
of mobility studies in the vadose zone.
Groundwater samples could be obtained for analysis and ensuing data
examined to characterize pollutant attenuation. Existing wells and wells
installed during previous steps could be used in such a program. In actual-
ity, a special sampling program would not be required because samples would
be available from these steps.
Preliminary Recommendations
The recommended preliminary approach would include all of the methods
discussed above. Costs for this step include only labor costs for construc-
tion of the attenuation factor versus pollutant matrix. This cost is given
in Table A-2.
26
-------
REFERENCES
Black, C.A. (ed.), Methods of Soil Analysis. Part 2, Chemical and Microbio-
logical Properties. In AGRONOMY, Series 9. American Society of Agronomy.
Madison, Wisconsin, 1965.
Drever, 0.I., J.W. Murphy, and R.C. Surdam, "The Distribution of As, Be, Cd,
Ca, Hg, Mo, Pb, and U Associated with the Wyodak Coal Seam, Powder River
Basin, Waning," Contributions to Geology, The University of Wyoming,
Vol 15, No. 2, pp 93-101, 1977.
Everett, L.G. (ed.), Groundwater Quality Monitoring of Western Coal Strip Min-
ing: Identification and Priority Ranking of Potential Pollution Sources,
EPA-600/7-79-024, U.S. Environmental Protection Agency, Monitoring and
Support Laboratory, Las Vegas, Nevada, January 1979.
Langmuir, Donald, "Controls on the Amounts of Pollutants in Subsurface
Waters," Earth and Mineral Sciences, The Pennsylvania State University,
Vol 42, No. 2, pp 9-13, November 1972.
Mooji, H., and F.A. Rovers, Recommended Groundwater and Soil Sampling Proce-
dures, Environmental Protection Service, Report EPS-4-EC, 76-7, Canada,
1976.
Tisdale, S.L., and W.L. Nelson, Soil Fertility and Fertilizers, MacMillan Pub-
lishing Co., 1975.
Todd, O.K., R.M. Tinlin, K.D. Schmidt, and L.G. Everett, Monitoring Ground-
water Quality: Monitoring Methodology, EPA-600/4-76-026, U.S. Environ-
mental Protection Agency, Monitoring and Support Laboratory, Las Vegas,
Nevada, 1976.
U.S. Department of Interior, Surface Mining Control and Reclamation Act of
1977, 30 CFR, Chapter VII, 1977.
27
-------
APPENDIX A
SUMMARY OF PRELIMINARY MONITORING DESIGNS
29
-------
TABLE A-l. SUMMARY OF PRELIMINARY RECOMMENDED MONITORING APPROACHES FOR REGRADED MINE SPOILS
TEMPO monitoring
steps
Identify potential
pollutants (spoils)
Monitoring needs
1. Characterize type,
concentration, and
distribution of po-
tential pollutants
in spoils
Alternative monitoring
approaches
Nonsampling method
1. Consult mining records on amount
and location of spoil placement
during backfill operations
Preliminary
recommendations
1. Compile available mine rec-
ords on backfill operations
and determine which materials
received special handling
Monitoring costs
1. Labor
a. Compile and review mine recla-
mation data (3 days): $180
CO
o
2. Determine materials which received
special handling and emplacement
Sampling method
1. Compile monthly maps of location
and elevation of spoils in re-
claimed areas
2. Maintain monthly photographic rec-
ord of the face of the regraded
spoils
3. Calculate or estimate gross weight
or volume of backfilled materials
4. Conduct composite or priority sam-
pling program described in text
5. Analyze spoil samples for pH, EC,
IDS, TOC, sulfate, nitrate, total
nitrogen, boron, fluoride, selected
trace elements, and radiologic ac-
tivity and species
2. Map and photograph backfill
areas, update information
monthly
3. Use priority sampling method
to characterize spoils
4. Analyze spoil samples for
pH, EC, IDS, TOC, sulfate,
nitrate, total nitrogen,
boron, fluoride, selected
trace elements, and radio-
logic activity and species
b. Sample handling preparation,
quality control, etc:
$10/samp1e
c. Mapping and photography
(1 week) geologist and assis-
ant: $500; monthly update
(2 days): $200
2. Operation
a. Chemical analysis: SlOO/sample
b. Air freight, refrigeration,
packing, etc: $25/set, 3 to 8
samples
c. Field transportation:
$0.17/mile
3. Capital
a. Sample containers, labels,
field books, chemicals, etc:
$2.50/sample
b. Photographic supplies: $2/day
c. Power hole auger: $300
Define groundwater 1. Determine if irriga-
usage tion is planned for
backfilled materials
Nonsampling method
1. Interview mine personnel to deter-
mine if regraded spoils will be
irrigated
2. Calculate consumptive water use
for revegetation
Sampling method
1. Install flow meters in irrigation
system delivery lines to determine
water usage
1. Determine if irrigation is
proposed for revegetation
1. Labor
a. Interview mine personnel to
determine if irrigation is
proposed for revegetation
(1 day): $40
2. Operation
None
3. Capital
None
(continued)
-------
TABLE A-l (continued)
TEMPO monitoring
steps
Monitoring needs
Alternative monitoring
approaches
Preliminary
recommendations
Monitoring costs
Define hydrogeo-
logic situation
Define undisturbed
groundwater system
Determine rate of
invasion of ground-
water into regraded
spoils
Nonsampling method
1. Compile existing hydrologic data
from wells within and adjacent to
the mine area
2. Compile geologic data from pub-
lished material, mine reports, and
oil or water well logs
Sampling method
1. Initiate water level survey
2. Conduct aquifer tests of selected
wells to determine transmissivity
and storage coefficient
1. Compile hydrogeologic data in 1. Labor
vicinity of reclamation area
2. Conduct aquifer test and
compile water level measure-
ments, as necessary (see
monitoring step, Evaluate
Attenuation of Pollutants
in the Saturated Zone for
aquifer test costs)
a. Compile and review existing
hydrogeologic data (2 weeks):
$600
2. Operation
a. See monitoring step. Evaluate
Attenuation of Pollutants in
the Saturated Zone
3. Capital
a. See monitoring step, Evaluate
Attenuation of Pollutants in
the Saturated Zone
Study existing
groundwater
quality
1. Characterize site-
specific groundwater
quality in terms of
physical and chemical
constituents
Nonsampling method
1. Compile water quality data from
mine operators, U.S. Geological
Survey, State agencies, private
consultants, etc.
Sampling method
1. Initiate water sampling program to
characterize major inorganics,
trace constituents, organics, and
mi croorogan i sms
2. Develop field program to periodi-
cally check water quality for pH,
EC, DO, nitrate, and chloride
1. Evaluate water quality from
available records
2. Initiate water sampling pro-
gram if additional or site-
specific data are required
3. Conduct periodic field checks
with laboratory samples taken
when marked changes occur in
parameters monitored
1. Labor
a. Compile and review water
quality data (1 week): $300
b. Sample handling, laboratory
preparation, quality control,
handling, etc: $5/sample
c. Sample-equipment installation:
$40/day
d. Field check water quality:
$2.50/sample
2. Operation
a. Chemical analysis: $200/sample
b. Field transportation:
$0.17/mile
c. Air freight, packing, refrig-
eration, etc., for water qual-
ity samples: $10/set, 1 to 3
samples
3. Capital
a. Field kit, bailer, and storage
chest: $750
b. Bottles, labels, chemicals:
$2.50/sample
(continued)
-------
TABLE A-l (continued)
TEMPO monitoring
steps
Evaluate infiltra-
tion potential
Monitoring needs
1. Characterize infil-
tration potential of
regraded spoils
Alternative monitoring
approaches
Sampling method
1. Conduct laboratory permeability
Preliminary
recommendations
1. Use ring infiltrometer to
assess infiltration into
regraded spoils
Monitoring costs
1. Labor
a. Installation of infiltrometer:
test of spoils
2. Use ring infiltrometers to measure
infiltration
3. Utilize sprinkler-type
infiltrometers
b. Conduct infiltration test:
$9/test
2. Operation
a. Field transportation:
$0.17/mile
3. Capital
a. Double-ring infiltrometer:
$150
CO
t\J
Evaluate mobility
of pollutants in
the vadose zone
Characterize quan-
tity and quality of
water moving through
the vadose zone
Nonsampling method
1. Use maps and survey results devel-
oped during monitoring step, Iden-
tify Potential Pollutants, dis-
cussed above, to estimate expected
water quality and quantity
Sampling method
1. Determine unsaturated, unsteady
flow in terms of moisture content
and pressure changes with time and
depth
2. Use electrical resistivity, neutron
scattering, or gravimetric methods
to measure soil moisture content
3. Use pressure plates, psychrometers,
or tensiometers to measure changes
in spoil pore pressure
4. Groundwater quality will be moni-
tored during monitoring step, Study
Existing Groundwater Quality
1. Delineate sampling sites
using maps and surveys
developed above
2. Conduct soil moisture study
using neutron probes
3. Evaluate soil pressure
changes using tensiometers
1. Labor
a. 100-ft neutron probe access
hole: $250/site
b. Neutron logging survey:
$50/site
c. Tensiometer installation:
$30/site
2. Operation
a. Field transportation:
$0.17/mile
3. Capital
a. Neutron logger and generator:
$15,000
b. Hardware and supplies to com-
plete neutron access well:
$5/ft (including seamless
steel pipe at $3.12/ft)
c. Tensiometers: $20 each
(continued)
-------
TABLE A-l (continued)
TEMPO monitoring
steps
Evaluate attenua-
tion of pollutants
in the saturated
zone
Monitoring needs
1. Determine aquifer
characteristics of
saturated spoils
2. Characterize physical
and chemical consti-
tuents of groundwater
in spoils
Alternative monitoring
approaches
Nonsampling method
1. Review site-specific hydrogeologic
data compiled in earlier monitor-
ing steps (Define Hydrogeologic
Situation)
Sampling method
Preliminary
recommendations
1. Review site-specific hydro-
geologic data
2. Conduct aquifer test in
regraded spoils
3. Collect water quality samples
from well developed in spoils
Monitoring costs
1. Labor
a. Review hydrogeological data
(completed for earlier moni-
toring steps)
b. Drilling labor and supervision
for monitoring well, with
equipment: $93/hour
CO
CO
1. Conduct aquifer pump test in and
adjacent to regraded spoils
2. Collect water level measurements
in and adjacent to regraded spoils
c. Sample handling, quality con-
trol, laboratory preparation:
SB/sample
d. Pumping tests (3 persons):
$140/day
2. Operation
a. Chemical analysis: $200/sample
b. Packing and air freight for
water quality samples: $25/
set, 4 to 8 samples
c. Field transportation:
$0.17/mile
d. Pump test (equipment rental
and operation): $3,000/test)
e. Field check water quality:
$2.50/sample
3. Capital
a. Field kit and storage chest:
$730
b. Hardware and supplies for
monitor well completion:
$15/ft
c. Bottles, labels, field note-
books, chemicals, etc:
$2.50/sample
d. Water level sounder: $200
-------
TABLE A-2. SUMMARY OF PRELIMINARY MONITORING DESIGN FOR RECLAMATION AIDS
TEMPO monitoring
steps
Monitoring needs
Alternative monitoring
approaches
Preliminary
recommendations
Monitoring costs
Identify potential
pollutants
oo
Delineate nutrients
being supplied to
reclaimed areas as
fertilizer
Nonsampling method
1. Determine fertilizer application
on reclaimed area through mine
company records
Sampling method
1. Sample surface waters adjacent to
reclaimed areas for fertilizer-
related pollutants
2. Analyze water quality samples for
major inorganics, trace constitu-
ents, total nitrogen, pH, EC
1. Define areas receiving
fertilizers
2. Sample surface waters before
and after fertilizer appli-
cation
3. Analyze first few samples
completely and later samples
for fertilizer components
only
1. Labor
a. Review mine reclamation plans
(2 days): $80
b. Sample handling, quality con-
trol, laboratory preparations:
SB/sample
2. Operation
a. Field transportation:
$0.17/mile
b. Chemical analysis: $200/sample
c. Packing, air freight: $10/set,
1 to 3 samples
3. Capital
a. Bottles, Tables, field chemi-
cals: $2.50/sample
Define groundwater
usage
1. Determine irrigation
requirements
Nonsampling method
1. Determine if groundwater will be
utilized for irrigation during
reclamation through discussions
with mine personnel
1. No monitoring will be planned 1. Labor
until an irrigation program
is established
None
2. Operation
None
3. Capital
None
Define hydrogeo-
logic situation
1. Characterize rela-
tionship between
areas of fertilizer
application and the
site-specific
hydrogeology
Nonsampling method
1. Utilize available mine records
compiled to characterize mine spoils
Sampling method
1. Field test physical characteris-
tics of regraded spoils
2. Use a combination of tensiometer
and neutron logging data to deter-
mine hydraulic conductivity and
flux in spoils
Collect available data on
modified hydrogeology of
reclaimed areas
Infer nature of near-surface
spoils from field recon-
naissance
1. Labor
a. Compile and review hydrogeo-
logic data (completed in
Monitoring Design for Regraded
Mine Spoils)
b. Reconnaissance field study
(3 days): $120
2. Operation
a. Field transportation:
$0.17/mile
(continued)
-------
TABLE A-2 (continued)
TEMPO monitoring
steps
Define hydrogeo-
logic situation
(continued)
Alternative monitoring
Monitoring needs approaches
3. Obtain soil and spoil samples using
dry drilling methods or augering
Preliminary
recommendations
Monitoring costs
3. Capital
None
4. Conduct pump test on wells completed
in saturated zone
Study existing
groundwater
quality
1. Define quality and
time trends of
groundwater within
and beneath re-
claimed areas
Nonsampling method
1. Collect data on existing well in
reclaimed area
Sampling method
1. Sample existing or supplemental
wells for water quality
1. Evaluate water quality from
available records
2. Sample existing or supple-
mental wells using recom-
mended sampling technique
3. Analyze initial samples com-
pletely with subsequent tests
for species concentrated
above site-specific background
levels
Labor, operation, and capital costs
for this monitoring step would be
the same as for Study Existing
Groundwater Quality for Regraded
Mine Spoils (Table A-l) and would be
attributed to that monitoring step.
co
tn
Evaluate infiltra-
tration potential
1. Define quantity of
water which infil-
trates the fertilized
spoil surface
Sampling method
1. Infiltration can be determined by
ring, sprinkler-type infiltrometers,
or laboratory permeability tests
1. Use ring infiltrometers to
measure infiltration into
regraded spoils
Labor, operation, and capital costs
are assigned to monitoring step,
Evaluate Infiltration Potential for
Regraded Spoils
Evaluate mobility
of pollutants in
the vadose zone
Define pollutant
attenuation factors
during flow through
vadose zone
Nonsampling method
1. Develop matrix table of pollutants
(columns) versus attenuating fac-
tors (rows) for subjective evalu-
ation of attenuation of pollutants
in the vadose zone
Sampling method
1. Install neutron moisture logging
equipment and tensiometer to deter-
mine fluid movement in the vadose
zone
2. Collect (drill or auger) soil,
spoil samples from the vadose zone
3. Install suction-cup lysimeters
to sample soil moisture
1. Construct pollutant attenu-
tion matrix table
2. Utilize data completed in
earlier monitoring steps
(Define Hydrogeologic Situa-
tion and Evaluate Mobility
of Pollutants in the Vadose
Zone, Table A-l) to evaluate
attenuation
3. Install a limited number of
suction-cup lysimeters and
tensiometers to evaluate soil
moisture
1. Labor
a. Construct pollutant attenua-
tion matrix (3 weeks): $900
b. Field installation of suction-
cup lysimeters: $30/site
c. Sample handling, quality con-
trol, laboratory preparation:
$51/sample
d. Field installation of tensiom-
eters: $30/site
2. Operation
a. Chemical analysis of soil/
spoil moisture samples:
$200/sample
b. Field transportation:
$0.17/mile
(continued)
-------
TABLE A-2 (continued)
TEMPO monitoring
steps Monitoring needs
Evaluate mobility
of pollutants in
the vadose zone
(continued)
Alternative monitoring
approaches
Prel iminary
recommendations Monitoring costs
c. Packing, air freight for water
quality samples: $10/set,
1 to 3 samples
3. Capital
a. Bottles, labels, chemicals,
etc: $2.50/sample
b. Suction-cup lysimeters:
$4 each
c. Tenslometers: $20 each
Evaluate attenua- 1. Determine attenuation Nonsampling method
tion of pollutants
in the saturated
CO
CT>
of source pollutants
during flow in zone
of saturation
1. Construct attenuation matrix for
saturated zone similar to that
for the vadose zone
Sampling method
1. Use aquifer characteristics (dis-
turbed and undisturbed) and water
quality analysis collected in alter-
native monitering steps (Identify
Potential Pollutants, Study Hydro-
geologic Situation, Evaluate Mobil-
ity of Pollutants in the Vadose
Zone and Evaluate Attenuation of
Pollutants in the Saturated Zone,
Table A-l) to evaluate pollutant
attenuation in saturated zone
1. Construct attenuation matrix
table for saturated zone
2. Evaluate attenuation of pol-
lutants based on available
and developed data
1. Labor
a. Construct pollutant attenua-
tion matrix (3 weeks): $900
2. Operation
None
3. Capital
None
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APPENDIX B
METRIC CONVERSION TABLE*
Nonmetric units
inch (in)
feet (ft)
square feet (ft')
yards
square yards
miles
square miles
acres
gallons
cubic feet (ft3)
barrels (oil)
acre/ft
gallons/square foot per minute
cubic feet/secpnd
gallons/minute''
galIons/day
million gal Ions/day
pounds
tons (short)
pounds/acre
parts per million (ppm)
Multiply by
25.4
2.54
0.3048
0.290
91.44
0.914
1.6093
3.599
4.047
4.047
,785
,785
,785
,590
1.108
40.74
3.532
6.308
3.785
28.32
0.028
0.454
.536
.072
0.907
1.122
1
3.
3.
3.
1.
4.
9.
-2
x 10
x 103
x 103
x lO'3
x 102
x 107
x 10-2
x ID'2
x
x ID'
Metric units
millimeters (mm)
centimeters (cm)
meters (m)
square meters (m2)
centimeters (cm)
square meters (m2)
kilometers (km)
square kilometers (km2)
square meters (m2)
hectares (ha)
cubic centimeters (cm3)
cubic meters (m3)
liters (1)
liters (1)
liters (1)
liters/square meter per minute
liters/second
liters/second
liters/day
liters/second
cubic meters/second
kilograms (kg)
tons (metric) (M.T.)
kilograms (kg)
tons (metric) (M.T.)
kilograms/hectare (kg/ha)
milligrams per liter (mg/1)
* English units were used in this report becuase of their current usage and
familiarity in industry and the hydrology-related sciences.
1 gpm = 1.6276 afa.
37
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-80-109
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
GROUNDWATER QUALITY MONITORING OF WESTERN COAL STRIP
MINING: Preliminary Designs for Reclaimed Mine
Sources of Pollution
5. REPORT DATE
June 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Lome G. Everett and Edward W. Hoylman (editors)
8. PERFORMING ORGANIZATION REPORT NO,
GE79TMP-43
9. PERFORMING ORGANIZATION NAME AND ADDRESS
General Electric Company - TEMPO
Center for Advanced Studies
Santa Barbara, California 93102
10. PROGRAM ELEMENT NO.
1NE833
11. CONTRACT/GRANT NO.
68-03-2449
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency-Las Vegas, Nevada
Office of Research and Development
Environmental Monitoring Systems Laboratory
Las Vegas, Nevada 89114
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/07
15. SUPPLEMENTARY NOTES
Project officer Leslie G. McMillion
16. ABSTRACT
This report is the fourth in a series of studies to assess the impact on
groundwater quality of coal strip mining in the western United States. Presented
are preliminary groundwater monitoring design guidelines for reclaimed mine areas.
The study area for this
the major coal fields in
report is
the Powder
evaluation,
provide alternative monitoring
and
including regarded spoils and reclamation aids
Campbell County, Wyoming, which overlies one of
River Basin.
The monitoring design consists of a sequence of data gathering,
decision steps used to assess monitoring needs,
approaches to address these needs, and make preliminary recommendations. Cost
estimates for required labor, operating expenses and capital outlay for each
monitoring step are provided. Using the General Electric-TEMPO generic monitoring
methodology (Todd et al., 1976), the following information assessment steps are
evaluated for each pollutant source: identify potential pollutants, define ground-
water usage, define hydrogeologic situation, study existing groundwater quality,
evaluate infiltration potential, evaluate mobility of pollutants in vadose zone, and
evaluate attenuation of pollutants in the saturated zone. Multiple passes through
the assessment steps, with each pass comprising a more complete and costly data
collection and evaluation process, are used to "scale-up" monitoring to a site-
^ ^x t • ^ %* y i ^^ i i *^ • » ** ^^ S*^^ ^*i^*^ y • v<>— ™ ^^a***i
specific, cost-effective level.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
COS AT I Field/Group
Groundwater
Groundwater quality
Waste management
Coal mining
Sanitary landfills
Strip mining
Septic tanks
Groundwater movement
Monitoring wells
Monitoring methodology
43F
446
48A
68C
68D
91A
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
52
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (Rev.4-77) Previous Edition is obsolete
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