EPA/DOE
MINE WASTE TECHNOLOGY
PROGRAM
Technology Testing for Tomorrow's Solutions
MINE
.WASTE
TECHNOLOGY
PROGRAM
2000 ANNUAL REPORT
EPA DOE Montana Tech Implemented by MSE, Ire.
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Copper smelter circa 1890
Cover photos courtesy of C. Oven Smilhers
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EPA/DOE
MINE WASTE TECHNOLOGY
PROGRAM
2000 ANNUAL REPORT
Prepared by:
MSB Technology Applications, Inc.
P.O. Box 4078
Butte, Montana 59702
Mine Waste Technology Program
Interagency Agreement Management Committee
IAG ID NO. DW89938870-01-0
Prepared for:
U.S. Environmental Protection Agency
Office of Research and Development
National Risk Management Research Laboratory
26 W. Martin Luther King Drive
Cincinnati, Ohio 46268
and
U.S. Department of Energy
National Energy Technology Laboratory
P.O. Box 10940
Pittsburgh, Pennsylvania 15236-0940
Contract No. DE-AC22-96EW96405
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CONTENTS
Page
Vision Statement for the Butte Mine Waste Technology Program 1
Program Manager's Executive Summary 3
Introduction 5
Program Overview 7
Organizational Structure 9
Activities 11
Descriptions, Accomplishments, and Future Direction 11
Activity I Overview—Issues Identification 11
Activity II Overview—Quality Assurance 11
Activity III Overview—Pilot-Scale Demonstrations 12
Project 3 Sulfate-Reducing Bacteria Demonstration 12
Project 8 Underground Mine Source Control 14
Project 10 Surface Waste Piles—Source Control 15
Project 12 Sulfate-Reducing Bacteria Reactive Wall Demonstration 18
Project 12A Calliope Mine Internet Monitoring System 23
Project 13 Hydrostatic Bulkhead with Sulfate-Reducing Bacteria 26
Project 14 Biological Cover Demonstration 26
Project 15 Tailings Source Control 29
Project 16 Integrated Passive Biological Treatment Process Demonstration 30
Project 19 Site In Situ Mercury Stabilization Technologies 31
Project 20 Selenium Removal/Treatment Alternatives 32
Project 21 Integrated Process for Treatment of Berkeley Pit Water 35
Project 22 Phosphate Stabilization of Mine Waste Contaminated Soils 36
Project 23 Revegetation of Mining Waste Using Organic Amendments and Evaluate
the Potential for Creating Attractive Nuisances for Wildlife 37
Project 24 Improvements in Engineered Bioremediation of Acid Mine Drainage 40
Activity IV Overview 41
Project 11 Pit Lake System Characterization and Remediation for Berkeley Pit—Phase II . 42
Project 12 An Investigation to Develop a Technology for Removing Thallium from Mine
Wastewaters 43
Project 13 Sulfide Complexes Formed from Mill Tailings Project 44
Project 14 Artificial Neural Networks as an Analysis Tool for Geochemical Data 44
Project 15 Imaging Spectroscopy—An Initial Investigation 45
Project 16 Pit Lake System Characterization and Remediation for Berkeley Pit—Phase III . 45
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Activity V Overview—Technology Transfer 46
Activity VI Overview—Training and Education 47
Financial Summary 49
Completed Activities 50
Activity III
Project 1 Remote Mine Site Demonstration 50
Project 2 Clay-Based Grouting Demonstration 51
Project 4 Nitrate Removal Demonstration 51
Project 5 Biocyanide Demonstration 52
Project 6 Pollutant Magnet 53
Project 7 Arsenic Oxidation 54
Project 9 Arsenic Removal 55
Project 11 Cyanide Heap Biological Detoxification Demonstration 56
Project 17 Lead Abatement Demonstration 56
Project 18 Gas-Fed Sulfate-Reducing Bacteria Berkeley Pit Water Treatment 57
Activity IV
Project 1 Berkeley Pit Water Treatment 58
Project 2 Sludge Stabilization 59
Project 3 Photoassisted Electron Transfer Reactions Research 59
Project 3A Photoassisted Electron Transfer Reactions for Metal-Complexed Cyanide .... 60
Project 3B Photoassisted Electron Transfer Reactions for Berkeley Pit Water 61
Project 4 Metal Ion Removal from Acid Mine Wastewaters by Neutral
Chelating Polymers 62
Project 5 Removal of Arsenic as Storable Stable Precipitates 63
Project 7 Berkeley Pit Innovative Technologies Project 64
Project 8 Pit Lake System—Characterization and Remediation for the Berkeley Pit .... 64
Project 9 Pit Lake System—Deep Water Sediment/Pore Water Characterization and
Interactions 65
Project 10 Pit Lake System—Biological Survey of Berkeley Pit Water 66
Key Contacts 67
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VISION STATEMENT
FOR THE BUTTE MINE
WASTE TECHNOLOGY PROGRAM
THE PROBLEM
Mining activities in the United States (not counting
coal) produce between 1 and 2 billion tons of mine
waste annually. These activities include extraction
and beneficiation of metallic ores, phosphate,
uranium, and oil shale. Over 130,000 of these
noncoal mines, concentrated largely in nine
western states, are responsible for polluting over
3,400 miles of streams and over 440,000 acres of
land. About seventy of these sites are on the
National Priority List for Superfund remediation.
In the 1985 Report to Congress on the subject, the
total noncoal mine waste volume was estimated at
50 billion tons, with 33% being tailings, 17%
dump/
heap leach wastes and mine water, and 50%
surface and underground wastes. Since many of
the mines involve sulfide minerals, the production
of acid mine drainage (AMD) is a common
problem from these abandoned mine sites. The
cold temperatures in the higher elevations and
heavy snows frequently prevent winter site access.
The combination of acidity, heavy metals, and
sediment have severe detrimental environmental
impacts on the delicate ecosystems in the West.
THE PHILOSOPHY/VISION
End-of-pipe treatment technologies, while essential
for short-term control of environmental impact
from mining operations, are a stop-gap approach
for total remediation. Efforts need to be made on
improving the end-of-pipe technologies to reduce
trace elements to low levels for applications in
ultra-sensitive watersheds and for reliable operation
in unattended, no power situations. The concept of
pollution prevention, emphasizing at-source control
and resource recovery, is the approach of choice
for the long-term solution. Our objective in the
Butte Mine Waste Technology Program is not to
assess the environmental impacts of the mining
activities, but it is to develop and prove
technologies that provide satisfactory short- and
long-term solutions to the remedial problems facing
abandoned mines and the ongoing compliance
problems associated with active mines, not only in
Montana but throughout the United States.
THE APPROACH
There are priority areas for research, in the
following order of importance:
Source Controls, Including In Situ Treatments
and Predictive Techniques
It is far more effective to attack the problem at its
source than to attempt to deal with diverse and
dispersed wastes, laden with wide varieties of
metal contaminants. At-source control
technologies, such as sulfate-reducing bacteria;
biocyanide oxidation for heap leach piles; transport
control/pathway interruption techniques, including
infiltration controls, sealing, grouting, and plugging
by ultramicrobiological systems; and AMD
production prediction techniques should strive
toward providing a permanent solution, which of
course is the most important goal of the program.
Treatment Technologies
Improvements in short-term end-of-pipe treatment
options are essential for providing immediate
alleviation of some of the severe environmental
problems associated with mining, and particularly
with abandoned ore mines. Because immediate
solutions may be required, this area of research is
extremely important to effective environmental
protection.
Resource Recovery
In the spirit of pollution prevention, much of the
mining wastes, both AMD (e.g., over 25 billion
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gallons of Berkeley Pit water) and the billions of
tons of mining/beneficiation wastes, represent a
potential resource as they contain significant
quantities of heavy metals. While remediating
these wastes, it may be feasible to incorporate
resource recovery options to help offset remedial
costs.
THE PARTNERSHIPS
In these days of ever-tightening budgets, it is
important that we leverage our limited funding with
other agencies and with private industry. We are
aggressively working to integrate the Butte
program with the U.S. Department of Energy
Resource Recovery Project to leverage both
budgets. The Bureau of Land Management and
Forest Service participate by providing sites for
demonstrations of the technologies. It is important
where these technologies have application to active
mining operations to achieve cost-sharing
partnerships with the mining industry to test the
technologies at their sites. Within the U.S.
Environmental Protection Agency, the Butte
program is coordinated and teamed, where
appropriate, with the Superfund Innovative
Technology Evaluation (SITE) program to leverage
the funding and maximize the effectiveness of both
programs. Several joint projects are underway,
and more are planned.
A considerable resource and willing partner is the
University system (such as Montana Tech of the
University of Montana, University of
Montana-Missoula, Montana State
University-Bozeman, and the Center for Biofilm
Engineering), which can conduct the more basic
type of research essential to kinetics
characterization and bench-scale test more
experimental, less developed concepts at minimal
cost to the program, while at the same time
providing environmental education that will be
useful to the region and to the Nation. The Butte
Mine Waste Technology Program supports
cooperative projects between the educational
system and the mining industry, where teams of
students conduct research of mine site-specific
problems, often with monetary support from the
industry. The results are made available to the
industry as a whole and to the academic
community.
THE SCIENCE
The research program is peer-reviewed
semiannually by the Technical Integration
Committee (TIC), who technically reviews all
ongoing and proposed projects. The TIC is
composed of technical experts from the cooperating
agencies, academia, environmental stakeholders,
and industry and their consultants.
Roger C. Wilmoth
Chief, Industrial Multimedia Branch
Sustainable Technology Division
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
(MS 445)
26 W. Martin Luther King Drive
Cincinnati, OH 45268
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PROGRAM MANAGER'S
EXECUTIVE SUMMARY
The Mine Waste Technology Program (MWTP)
Annual Report for fiscal 2000 summarizes the
results and accomplishments for the various
activities within the Program. The MWTP has met
its goals by providing assistance to the public and
forming cooperative teams drawn from
government, industry, and private citizens. The
funds expended have returned tangible results,
providing tools for those faced with mine waste
remediation challenges.
After 10 years, everyone involved with MWTP can
look with pride to the Program's success.
Technology development has proceeded
successfully through the efforts of MSB
Technology Applications, Inc. (MSB) and its prime
subcontractor Montana Tech.
MSB has developed twenty-seven field-scale
demonstrations, several of which are attracting
attention from the stakeholders involved in the
cleanup of mine wastes.
Montana Tech has developed fourteen bench-scale
projects, five of which are ongoing during 2000.
Numerous activities are associated with the
development of a field-scale demonstration.
Among these activities are acquiring federal and
state permits, securing liability limiting access
agreements, developing and adhering to health and
safety operation plans, and complying with the
National Environmental Policy Act and other
federal and state environmental oversight statutes.
The Program has received substantial support from
state and federal agencies, the mining industry,
environmental organizations, and numerous
associations interested in mining and development
of natural resources at state, regional, and national
levels.
Montana Tech continued the post-graduate degree
program with a mine waste emphasis. The quality
of short courses offered by Montana Tech is
becoming highly recognized among the mine waste
remediation community.
The MWTP recognizes its major accomplishments
and looks forward to providing new and innovative
technologies; meeting the challenges of mine waste
remediation; and providing economical, permanent
solutions to the nation's mineral waste problems.
Creighton Barry
MSB MWTP Program Manager
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INTRODUCTION
Mining waste generated by active and inactive
mining production facilities and its impact on
human health and the environment are a growing
problem for Government entities, private industry,
and the general public. The nation's reported
volume of mine waste is immense. Presently, there
are more than sixty sites on the U.S.
Environmental Protection Agency's National
Priorities List.
Environmental impacts associated with inactive and
abandoned mines are common to mining districts
around the country, as shown in Table 1.
Total estimated remediation costs for these states
range from $4 to $45 billion.
Health effects from the predominate contaminants
in mine waste range from mild irritants to proven
human carcinogens, such as cadmium and arsenic.
The large volume of mine wastes and consequential
adverse environmental and human health effects
indicates an urgency for cleanup of abandoned,
inactive, and active mining facilities. The
environmental future of the United States depends
in part on the ability to deal effectively with mine
waste problems of the past and present, and more
importantly, to prevent mine waste problems in the
future.
According to a 1985 report to Congress, mining
and related activities generate anywhere from 1 to
2
billion tons of waste each year with a current total
waste volume of 50 billion tons. Of this total
volume, approximately 85% is attributed to copper,
iron ore, uranium, and phosphate mining and
related activities. Approximately one-half of the
waste generated is mining waste, one-third is
tailings, and the balance consists of dump/heap
leaching wastes and mine water.
The fiscal year (FY) 1991 Congressional
Appropriation allocated $3.5 million to establish a
pilot program in Butte, Montana, for evaluating
and testing mine waste treatment technologies. The
Mine Waste Technology Program (MWTP)
received additional appropriations of $3.5 million
in FY91, $3.3 million in FY94, $5.9 million in
FY95, $2.5 million in FY96, $7.5 million in FY97,
$6.0 million in FY98 and FY99, and $4.3 million
in FYOO.
The projects undertaken by this Program focus on
developing and demonstrating innovative
technologies at both the bench- and pilot-scale that
treat wastes to reduce their volume, mobility, or
toxicity. To convey the results of these
demonstrations to the user community, the mining
industry, and regulatory agencies, MWTP includes
provisions for extensive technology transfer and
educational activities. This report summarizes the
progress MWTP made in FYOO.
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Table 1. Number and types of sites and abandoned mine lands in Western Region.
State
Alaska
Arizona
California
Colorado
Idaho
Michigan
Montana
Nevada
New Mexico
Oregon
South Dakota
Texas
Utah
Wisconsin
Wyoming
Estimated Number of Sites or Land Areas
10,910 sites
95,000 sites
11,500 sites
20,229 sites covering
26,584 acres
8,500 sites covering
18,465 acres
400-500 sites
19,751 sites covering
11,256 acres
400,000 sites
7,222 sites covering
13,585 acres
3,750 sites
4,775 acres
17,300 acres
14,364 sites covering
12,780 acres
200 acres
5, 000 acres
Classification and Estimated Number
mine dumps - 1,000 acres
disturbed land - 27,680 acres
mine openings - 500
hazardous structures - 300
polluted water - 2,002 acres
mine dumps - 40,000 acres
disturbed land - 96,652 acres
mine openings - 80,000
polluted water - 369,920 acres
mine dumps - 171 acres
mine openings - 1,685
polluted water 830,720 acres
mine dumps - 11,800 acres
disturbed land - 13,486 acres
mine openings - 20,229
hazardous structures - 1,125
polluted water - 84,480 acres
mine dumps - 3,048 acres
disturbed land - 24,495 acres
mine openings - 2,979
hazardous structures - 1,926
Accurate information not available.
polluted water - 715,520 acres
mine dumps - 14,038 acres
disturbed land - 20,862 acres
mine openings - 4,668
hazardous structures - 1,747
Accurate information not available.
polluted water - 44, 160 acres
mine dumps - 6,335 acres
disturbed land - 25,230 acres
mine openings - 13,666
hazardous structures - 658
polluted water - 140,800 acres
mine dumps - 180 acres
disturbed land - 61,000 acres
mine openings - 3,750
hazardous structures - 695
Accurate information not available.
Accurate information not available.
polluted water - 53,120 acres
mine dumps - 2,369 acres
disturbed land - 18,873 acres
mine openings - 14,364
hazardous structures - 224
Accurate information not available.
Accurate information not available.
Information was collected from the following sources and is only an estimate of the acid mine drainage problem in the West.
-Bureau of Land Management -U.S. Department of the Interior
-Bureau of Mines -U.S. Forest Service
-Mineral Policy Center -U.S. Geological Survey
-National Park Service -U.S. General Accounting Office
-U.S. Department of Agriculture -Western Governor's Association Mine Waste Task Force Study
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PROGRAM OVERVIEW
FISCAL 2000 PROGRAM
This Mine Waste Technology Program (MWTP)
annual report covers the period from
October 1, 1999, through September 30, 2000.
This section of the report explains the MWTP
organization and operation.
MISSION
The mission of MWTP is to provide engineering
solutions to national environmental issues resulting
from the past practices of mining and smelting
metallic ores. In accomplishing this mission,
MWTP develops and conducts a program that
emphasizes treatment technology development,
testing and evaluation at bench- and pilot-scale, and
an education program that emphasizes training and
technology transfer. Evaluation of the treatment
technologies focuses on reducing the mobility,
toxicity, and volume of waste; implementability;
short- and long-term effectiveness; protection of
human health and the environment; community
acceptance; and cost reduction.
The statement of work provided in the Interagency
Agreement between the U.S. Environmental
Protection Agency and the U.S. Department of
Energy identifies six activities to be completed by
MWTP. The following descriptions identify the
key features of each and the organization
performing the activity.
ACTIVITY I: ISSUES
IDENTIFICATION
Montana Tech of the University of Montana
(Montana Tech) is documenting mine waste
technical issues and innovative treatment
technologies. These issues and technologies are
then screened and prioritized in volumes related to
a specific mine waste problem. Technical issues of
primary interest are Mobile Toxic
Constituents—Water/Acid Generation; Mobile
Toxic Constituents—Air, Cyanide, Nitrate,
Arsenic, Pyrite, Selenium, and Thallium; and Pit
Lakes. Wasteforms reviewed related to these
issues include point- and nonpoint-source acid
drainage, abandoned mine acid drainage, stream-
side tailings, impounded tailings, priority soils, and
heap leach-cyanide/acid tailings. In addition,
under this task Montana Tech produced a CD-
ROM based summary of the Program in two
volumes—Annual Report and Activities in Depth.
The CDs can be obtained from the personnel listed
in the Contacts Section of this report. The Annual
Report data is also available on the web at
www. epa. go v/ORD/NRMRL/std/mtb.
ACTIVITY II: GENERIC QUALITY
ASSURANCE PROJECT PLAN
In 2000, MSB Technology Applications, Inc.
(MSB) prepared a Quality Management Plan that
provides specific instructions for data gathering,
analyzing, and reporting for all MWTP activities.
MSB develops project-specific quality assurance
project plans and provides oversight for all quality
assurance activities.
ACTIVITY III: PILOT-SCALE
DEMONSTRATIONS
Pilot-scale demonstration topics were chosen after a
thorough investigation of the associated technical
issue was performed, the specific wasteform to be
tested was identified, peer review was conducted,
and sound engineering and cost determination of
the demonstration were formulated.
MSB continued thirteen field-scale demonstrations
during fiscal 2000. Three field demonstrations
were completed: Cyanide Heap Biological
Detoxification; Lead Abatement; and Gas-Bed
Sulfate-Reducing Bacteria for Berkeley Pit
Treatment. One project, Phosphate Stabilization of
Heavy Metals Contaminated Mine Waste Yard
Soils, was begun.
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ACTIVITY IV: BENCH-SCALE
EXPERIMENTS
Montana Tech successfully completed three
projects during fiscal 2000: 1) Pit Lake
System—Character-ization and Remediation for the
Berkeley Pit; 2) Pit Lake System—Deep Water
Sediments/Pore Water Characterization and
Interactions; and 3) Pit Lake System—Biological
Survey of the Berkeley Pit. Four projects were
begun: 1) and investigation to develop a technology
for removing thallium from mine waste; 2) sulfide
complexes formed from depositing mill tailings into
a pit lake; 3) artificial neural networks as an
analysis tool for geochemical data; and 4) Pit Lake
System Characterization and Remediation of
Berkeley Pit—Phase III. In addition, Project 11,
Pit Lake System Characterization and Remediation
for Berkeley Pit—Phase II, which assesses the
effect of organic carbon, wall rock/water
interactions, bacteria for natural remediation, and
the effect of redepositing neutral tailings into the
Berkeley Pit was in progress.
ACTIVITY V:
TRANSFER
TECHNOLOGY
MSB is responsible for preparing and distributing
reports for MWTP. These include routine weekly,
monthly, quarterly, and annual reports; technical
progress reports; and final reports for all MWTP
activities. MSB also publicizes information
developed under MWTP in local, regional, and
national publications. Other means of information
transfer include public meetings, workshops, and
symposiums.
ACTIVITY VI:
PROGRAMS
EDUCATIONAL
Montana Tech has developed a post-graduate
degree program with a mine waste emphasis. The
program contains elements of geophysical,
hydrogeological, environmental, geochemical,
mining and mineral processing, extractive metallur-
gical, and biological engineering.
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ORGANIZATIONAL STRUCTURE
MANAGEMENT ROLES AND
RESPONSIBILITIES
Management of the Mine Waste Technology
Program (MWTP) is specified in the Interagency
Agreement. The roles and responsibilities of each
organization represented are described below. The
MWTP organizational chart is presented in
Figure 1.
U.S. ENVIRONMENTAL
PROTECTION AGENCY
The Director of the National Risk Management
Research Laboratory (NRMRL) in Cincinnati,
Ohio, is the principal U.S. Environmental
Protection Agency Office of Research and
Development representative on the Interagency
Agreement Management committee. NRMRL
personnel are responsible for management
oversight of technical direction, quality assurance,
budget, schedule, and scope.
DEPARTMENT OF ENERGY
The Director of the National Energy Technology
Laboratory (NETL) is the principal U.S.
Department of Energy (DOE) representative on the
Interagency Agreement Management committee.
NETL personnel provide contract oversight for
MWTP. MSB Technology Applications, Inc.
(MSB) is responsible to NETL for adherence to
environmental, safety and health requirements;
regulatory requirements; National Environmental
Protection Act requirements, and conduct of
operations of all projects.
MSE TECHNOLOGY
APPLICATIONS, INC.
MSE, under contract with DOE, is the principal
performing contractor for MWTP. The MWTP
Program Manager is the point of contact for all
mine waste activities. The Program Manager is
responsible for program management and
coordination, program status reporting, funds
distribution, and communications.
An MSE project manager has been assigned to
each MWTP project and is responsible to the
MWTP Program Manager for overall project
direction, control, and coordination. Each project
manager is responsible for implementing the
project within the approved scope, schedule, and
cost. MSE also provides all staff necessary for
completing Activities III and V and oversight of
Activities II, III, IV, and VI.
MONTANA TECH OF THE
UNIVERSITY OF MONTANA
As a subcontractor to MSE, Montana Tech of the
University of Montana is responsible to the MWTP
Program Manager for all work performed under
Activities I, II, IV, and VI. The responsibility for
overall project direction, control, and coordination
of the work to be completed by Montana Tech is
assigned to the MWTP Montana Tech Project
Manager.
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TECHNICAL INTEGRATION COMMITTEE
The Technical Integration Committee reviews
progress in meeting the goals of MWTP and to
alert the Interagency Agreement Management
Committee to pertinent technical concerns. The
committee provides information on the needs and
requirements of the entire mining waste technology
user community and assists with evaluating
technology demonstrations as well as technology
transfer. This committee is comprised of
representatives from both the public and private
sectors.
MINE WASTE TECHNOLOGY PROGRAM
ORGANIZATIONAL STRUCTURE
EPA Montana Operations |
Office 1
1
Mike Bishop I
EPA Quality Assurance I
Officer l_
Lauren Drees |
Interagency Agreement \
Management 1
RitaBajura TimOppelt |
1
-*• EPA Pro]e
Roger L
i
i ,
ct Officer f
Vilmoth 1
. DOE-Headc
I
I
! h <-• —
i DOE Project Officer 1 ]
i Dr. MadhavR. Ghate IT i
i
i
MSE - Creighton Barry 1
Montana Tech - Karl Burgher 1
1
1
Activity 1 I Activity II )
MT | MSE |
JefWal
uarters 1
tter 1
f Technical Integration Committee ^
Rory Tibbals Golden Sunlight Mine
David Gaskin State of Nevada
Ronald Hill Environmental Consultant
John Ray Montana Environmental
Information Center
Robert Robinson U.S. Department of Interior
Bureau of Land Management
Daryl Reed State of Montana
Thomas Wildeman Colorado School of Mines
John Pantano ARCO
John Martin EPA NRMRL
Marshall Leo State of West Virginia
Tom Mclntyre Advanced Silicon Materials
Carol Russell EPA Region 8
Jim Dunn EPA Region B
Nick Ceto EPA Region 10
Steve Hoffman EPA Office of Solid Waste
\^ ^
Activity III I Activity IV I Activity V 1
MSE | M7 | MSE |
Activity VI 1
M7 |
Figure 1. MWTP organizational chart.
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ACTIVITIES
DESCRIPTIONS,
ACCOMPLISHMENTS, AND
FUTURE DIRECTION
This section describes the Mine Waste Technology
Program (MWTP) Activities I through VI and
includes project descriptions, major project
accomplishments during fiscal 2000, and future
project direction.
ACTIVITY I OVERVIEW
ISSUES IDENTIFICATION
This activity focuses on documenting mine waste
technical issues and identifying innovative
treatment technologies. Issues and technologies are
screened and prioritized in volumes related to a
specific mine waste problem/market.
Following completion of a volume, appendices are
prepared. Each appendix links a candidate
technology with a specific site where such a
technology might be applied. The technology/site
combinations are then screened and ranked.
Technical Issue Status
The status of the volumes approved for
development includes:
• Volume 1, Mobile Toxic Constituents—Water
and Acid Generation, complete.
• Volume 2, Mobile Toxic Constituents—Air,
complete.
• Volume 3, Cyanide, complete.
• Volume 4, Nitrate, complete.
• Volume 5, Arsenic, complete.
• Volumes 1-5 Summary Report, complete.
• Volume 6, Pyrite, complete.
• Volume 7, Selenium, complete.
• Volume 8, Thallium, complete.
• Volume 9, Pit Lakes, in progress.
The status of the appendices for approved projects
includes:
• Volume 1, Appendix A (Remote Mine Site),
complete.
• Volume 1, Appendix B (Grouting), complete.
• Volume 1, Appendix C (Sulfate-Reducing
Bacteria), complete.
• Volume 3, Appendix A (Biocyanide),
complete.
• Volume 4, Appendix A (Nitrate), complete.
ACTIVITY II OVERVIEW
QUALITY ASSURANCE
The objective of this activity is to provide support
to individual MWTP projects by ensuring all data
generated is legally and technically defensible and
that it supports the achievement of individual
project objectives. The primary means of carrying
out this activity is the Quality Assurance Project
Plan, which is written for each project. This plan
specifies the quality requirements the data must
meet, clearly states the project objectives, describes
all sampling and measurement activities, and
contains standard operating procedures, when
applicable. Other functions of this activity include
reviewing technical systems, validating data,
implementing corrective action, and reporting to
project management.
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ACTIVITY III OVERVIEW
PILOT-SCALE DEMONSTRATIONS
The objective of this activity is to demonstrate
innovative and practical remedial technologies at
selected waste sites, a key step in proving value for
widespread use and commercialization.
Technologies and sites are selected primarily from
the prioritized lists generated in the Volumes from
Activity I, or they may be a scale-up from bench-
scale experiments conducted under Activity IV.
ACTIVITY III, PROJECT 3:
SULFATE-REDUCING BACTERIA
DEMONSTRATION
Project Overview
Acid generation typically accompanies sulfide-
related mining activities and is a widespread
problem. Acid is produced chemically, through
pyritic mineral oxidation, and biologically, through
bacterial metabolism. This project focuses on a
source-control technology that has the potential to
significantly retard or prevent acid generation at
affected mining sites. Biological sulfate reduction
is being demonstrated at an abandoned hard-rock
mine site where acid production is occurring with
associated metal mobility.
Technology Description
For aqueous waste, this biological process is
generally limited to the reduction of dissolved
sulfate to hydrogen sulfide and the concomitant
oxidation of organic nutrients to bicarbonate. The
particular group of bacteria chosen for this
demonstration, sulfate-reducing bacteria (SRB),
require a reducing environment and cannot tolerate
aerobic conditions for extended periods. These
bacteria require a simple organic nutrient.
This technology has the potential to reduce the
contamination of aqueous waste in three ways.
First, dissolved sulfate is reduced to hydrogen
sulfide through metabolic action by the SRB.
Next, the hydrogen sulfide reacts with dissolved
metals forming insoluble metal sulfides. Finally,
the bacterial metabolism of the organic substrate
produces bicarbonate, increasing the pH of the
solution and limiting further metal dissolution.
At the acid-generating mine site chosen for the
technology demonstration, the Lilly/Orphan Boy
Mine near Elliston, Montana, the aqueous waste
contained in the shaft is being treated by using the
mine as an in situ reactor. An organic nutrient was
added to promote growth of the organisms. This
technology will also act as a source control by
slowing or reversing acid production. Biological
sulfate reduction is an anaerobic process that will
reduce the quantity of dissolved oxygen in the mine
water and increase the pH, thereby, slowing or
stopping acid production.
The shaft of the Lilly/Orphan Boy Mine was
developed to a depth of 250 feet and is flooded to
the 74-foot level. Acid mine water historically
discharged from the portal associated with this
level.
Pilot-scale work at the MSE Technology
Applications, Inc., Testing Facility in Butte was
performed in fiscal 1994 prior to the field
demonstration. The objective of these tests was to
determine how well bacterial sulfate reduction
lowers the concentration of metals in mine water at
the shaft temperature (8 °C) and pH (3).
Status
During fiscal 2000, the field demonstration was
again monitored on a regular basis. Figure 2
presents a cross-section of the mine and technology
installation.
During the past year of monitoring, the data
generally demonstrated a decrease in metals
concentrations (see Figure 3), with the exception of
manganese, which SRBs do not effectively remove.
An increase in metals was observed during spring
runoff as occurred in prior years; however, the
levels decreased when flow rates returned to
normal. Field demonstration monitoring has been
ongoing for 6 l/i years. Monitoring is scheduled to
be completed in June 2001.
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HEADFRAME SUPPORT
CABLES SECURED AT
SURFACE ^
WJECTIOW WELL
IWJECTIOW WELL
ASTATIC WATER LEVEL (74'te
LEGEND
- WATER LEVEL
INC.
REV: D DATE: 5/17/94
DRAETER: UC
DRAWING SCALE: WTS
PLOT SCALE: 48
Figure 2. Cross-section of the Lilly/Orphan Boy Mine and the technology
installation.
150
100
LU
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PORTAL: REMOVAL EFFICIENCIES
Field-scale Testing
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ACTIVITY III, PROJECT 8:
UNDERGROUND MINE SOURCE
CONTROL
Project Overview
A significant environmental problem at abandoned
underground mines occurs when the influx of water
contacts sulfide ores and forms acid and metal-
laden mine discharge. The Underground Mine
Source Control Project demonstrated that grout
materials can be used to reduce and/or eliminate
the influx of water into the underground mine
system by forming an impervious barrier that
results in reduced, long-term environmental
impacts of the abandoned mine.
geological, geochemical, and geophysical
information gathering directly related to the mine
and its operational history.
Phase Two encompassed source control material
testing. Approximately 40 materials were tested
according to ASTM methods for acid resist!veness,
shear strength, plasticity, compressive strength,
compatibility, and viscosity. The source control
grout material selected for injection was Hydro
Active Combi Grout, a closed-celled, expandable
polyurethane grout manufactured by de neef
Construction Chemicals, Inc. When compared to a
cement-based source control material, this material
offered the following advantages: greater retention
of plasticity; less deterioration due to the acidic
conditions and during rock movement; and better
Theological characteristics.
Technology Description
Ground water flow is the movement of water
through fractures, fissures, or intergranular spaces
in the earth. Some of the fractures are naturally
occurring, others were the result of blasting during
mining.
For this demonstration, a closed-cell, expandable
polyurethane grout was injected into the fracture
system that intercepts the underground mine
workings. The demonstration consists of three
phases: 1) extensive site characterization; 2) source
control material identification and testing; and 3)
source control material emplacement.
Phase One, completed in 1999, consisted of
characterization studies, including hydrogeological,
Status
The Miller Mine near Townsend, Montana, was
selected for the demonstration because the
underground workings were accessible, it has a
point-source discharge into the underground
workings, the slightly acidic inflow is laden with
heavy metals, and the inflow could be potentially
controlled using the source control technology.
Phases One and Two were completed in March
1999. Phase Three, the field emplacement (shown
in Figure 4), was completed in October 1999.
First year monitoring results indicate that the water
flow into the underground mine was reduced from
10 to 15 gpm to approximately 1 to 1.2 gpm as a
result of Phase III field emplacement.
-14-
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Figure 4. Grout emplacement in the underground mine workings.
ACTIVITY III, PROJECT 10:
SURFACE WASTE
PILES-SOURCE CONTROL
Project Overview
Surface waste piles from mining operations were
historically placed in drainage basins in front of the
haulage tunnel. Surface water in the drainage,
discharge from the mine, and precipitation usually
contacted the waste pile. The water came in
contact with the sulfide ore in the pile and
infiltrated through the pile, where acid formed and
the water became metal-laden. This water
percolated from the toe of the pile and flowed into
the closest surface water. The objective of this
Mine Waste Technology Program demonstration
was to provide source control technologies that
could be applied in situ, meaning that the pile is
stabilized in place and not excavated and moved to
another location for stabilization. By using
strategically applied in situ source control
technologies, there will be a decrease in water
infiltrating through the pile and ground water
contact with surface waste pile material, thereby,
decreasing the environmental impact.
Technology Description
Surface waste piles from historical mining activity,
in many cases, consist of broken, low-grade,
sulfide ores. When water and oxygen contact the
sulfide ores, acid is formed, resulting in increased
levels of dissolved metals in the water associated
with the pile. The source of the water infiltrating
the pile is usually precipitation onto the pile and/or
from surface water (i.e., discharge water from a
mine adit, stream flow, or in some instances
ponded stream/discharge water). When the water
discharges from the surface waste pile, it is acidic
and metal-laden causing a significant environmental
problem.
Usually in such situations, the surface waste pile is
excavated and placed in a designed repository.
However, this can be expensive, and in some
instances, excavation of the pile or construction of
a repository is not feasible. In certain instances, in
situ application of source control technologies at a
surface waste pile is the optimal solution. The
source control technologies are strategically placed
into the surface waste pile such that the infiltration
of surface water and ground water flow through the
pile are eliminated or reduced, resulting in a
reduction of acidic, metal-laden water.
-15-
-------
The demonstration consists of three phases: 1) site
characterization; 2) source control materials
testing; and 3) field emplacement.
Phase One, site characterization, included
geochemical, geological, hydrogeological, and
mineralogical studies that provided information
directly related to the surface waste pile, the mine,
the regional water system, and past operational
procedures.
Phase Two, source control materials testing, was
performed to determine if select source control
material were acid resistant, was affected by
wet/dry or freeze/thaw cycling, and if it would be
impervious once it was emplaced onto the surface
waste pile. The physical characteristics of the
surface waste pile material were also defined in the
bench-scale laboratory setting.
Status
The project site for this demonstration is the
Peerless Mining Property located south of Rimini,
Montana. The site was selected because of its size,
hydraulic characteristics, and its water quality (see
Figure 5). A major factor in the selection of the
site was that it had an acidic, metal-laden, point-
source discharge flowing from the toe of the
surface waste pile, and the upgradient water
sources were of better quality and near neutral pH.
Phases One and Two were finalized by March 26,
1999. Phase Three, field emplacement, was
initiated in September 1999 and finalized in
November 1999. At the Peerless Mine, both
surface water and ground water contacted the
surface waste pile material and contributed to the
acid mine drainage formation. Figure 6 shows the
French drain system constructed to hydraulically
control the ground water flow at the site.
The French drain was placed upgradient of the
surface waste pile allowing the ground water to be
transported away from the acid forming material.
Figure 7 shows a spray-applied cover being applied
to reduce the infiltration of precipitation through
the pile. The spray-applied cover material used at
the site (see Figure 8) was a flexible, urethane
grout called KOBAthane 4990, manufactured by
General Polymers, Inc.
Long-term monitoring results indicate that the
water quality of the seep flowing from the toe of
the surface waste pile was improved. After the
technology emplacement, the dissolved metal
concentrations for zinc, cadmium, and copper were
below the National Drinking Water Maximum
Contaminant Standards.
Figure 5. The Peerless Mine surface waste pile before the technology
demonstration.
-16-
-------
%
r *r
Figure 6. French drain installation.
••• • '"
Figure 7. Flexible, ur ethane grout being sprayed directly on the surface waste
pile.
-17-
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Figure 8. Peerless Mine surface waste pile after partially sprayed with the
urethane grout.
ACTIVITY III, PROJECT 12:
SULFATE-REDUCING BACTERIA
REACTIVE WALL
DEMONSTRATION
Project Overview
Thousands of abandoned mine sites in the western
United States impact the environment by
discharging acid mine drainage (AMD) to surface
water or ground water. Acid mine drainage is
formed when sulfide-bearing minerals, particularly
pyrite, produce oxygen and water in a chemical
reaction that results in an increased acidity of the
water (lowered pH), and increased concentration of
dissolved metals and sulfate.
At many abandoned mine sites in the West,
conventional treatment strategies for AMD (e.g.,
lime neutralization) are not feasible because of the
remoteness of the mine locations, insomuch as a
lack of a power source and limited site accessibility
in winter. Sulphate-reducing bacteria (SRB) are
capable of reducing the sulfate to sulfide,
decreasing the load of dissolved metals in the
effluent by precipitating metals as sulfides, and
increasing the pH of the effluent. To demonstrate
the feasibility of using SRB passive technology for
mitigation of AMD emanating from the toe of a
waste rock pile, three bioreactors were built at the
abandoned Calliope Mine site located near Butte,
Montana.
Technology Description
The Calliope mine site includes a collapsed adit
discharging water into a large (66,000 cubic yards)
waste rock pile. This relatively good quality water
flows over the top of the waste rock and
accumulates in a small lower pond at the toe of the
pile. The AMD is mostly produced by atmospheric
water that infiltrates the waste rock pile and
reappears on the surface at the toe of the pile
enriched in metals and with a pH of 2.6. This
AMD also flows to the pond where it mixes with
good quality water and lowers its pH. A portion of
the water that accumulates in the pond has been
diverted for treatment to three engineered
bioreactors that were built at the site to demonstrate
the SRB technology.
The SRB bioreactors constructed at the Calliope
abandoned mine site in the fall of 1998 are
approximately 70 feet long, 14 feet wide, and 6
feet high. They are placed in parallel (see Figure
9) downstream from the pond, allowing the AMD
to be piped to and treated in the reactors using
-18-
-------
gravity flow. The bioreactors are designed to
evaluate the SRB technology applied under
different environmental conditions.
Two bioreactors are placed in trenches. One is
constructed above the ground using a 12-foot-wide
metal half-culvert to investigate the impact of
seasonal freezing and thawing on SRB activity. To
evaluate the efficiency of the SRB at optimal pH
and oxidation-reduction potential (EH), two of the
reactors contain a passive pretreatment section to
increase the alkalinity of the AMD.
Each reactor is filled with a combination of organic
carbon and cobbles placed in discrete chambers
(see Figures 9 and 10). Reactors II and IV also
have a crushed limestone chamber. Each of these
media is expected to play a certain role in the
treatment train. 1) Organic carbon is the bacterial
food supply, and because it was provided in the
form of cow manure, also the SRB source. 2) For
the pretreatment section, a chamber with cow
manure was included to lower the EH of AMD. 3)
Crushed limestone provided the buffering capacity
to increase the pH of AMD in the pretreatment
section. 4) Cobbles placed in the reactive, primary
treatment section of the bioreactor constitute stable
substrate for bacterial growth.
Chambers filled with organic carbon or limestone
are each 5 feet long, whereas, chambers filled with
cobbles are 50 feet long. Such dimensions were
selected based on the literature review and
information acquired through the bench-scale test
that was conducted in the MSB Technology
Applications, Inc., laboratory in 1998. Preliminary
results of the bench-scale test, at the time of the
bioreactor's design, indicated the required
residence time in the reactors should range from 3
to 5 days. This resulted in the bioreactors being
sized for a flow rate of one gallon per minute. To
provide flexibility, the flow and hydraulic head
control systems placed in the bioreactors ensure a
much wider range of the residence time.
Organic
Carbon
CruEhadLJmeEtone
Organic
Car boo
- Troaie-d
AMD
Discharge
Piping
• Below
Ground
Reactors
Figure 9. Layout of bioreactors.
-19-
-------
Treated
AMD
Discharge
Liner
Longitudinal Cross-Section of a Bioreactor
AMD Supply::
Distribution System-1
2x4 Geogrid Hangers
Terraceir filled wi
Mix of Manure (80%)
and Cut Straw (20%)
4'
Liner __ Geotextile (woven) 40MilThk.
Geomembrane 40 Mjl Thk.
Geotextile (woven) 40 Mil Thk.
Cross-Section of the Organic Carbon Supply Chamber in Below Ground Bioreactor
Figure 10. Bioreactor's design.
The main challenges were to design the organic
carbon chambers so the AMD would permeate
through the entire cross-sectional area without
channeling and to ensure that the organic substrate
did not settle. These goals were achieved by
placing the organic substrate in the cellular
containment system consisting of 10 lifts of
Terracell™ (see geogrid in Figure 10) that would
limit settling of the organic matter to each
individual cell if it occurred. The Terracell™ lifts
were positioned at 600 degrees off the horizontal
plane to facilitate packing with the organic
substrate and to promote migration of AMD along
a wavy-shaped flowline.
Status
Reactor construction was completed in November
1998, and the reactors have been in operation since
December 1998. The operation plan stipulated that
the two below-grade reactors (II and III) would
flow at the rate of 1 gallon per minute (gpm) and
reactor IV would be shut down for the winter to let
it freeze full of AMD. After spring thawing, the
flow rate of reactor IV would also be 1 gpm. The
1-gpm flow rate allows for approximately a 5V£-
day residence time of AMD in reactors II and IV
and a
4V2-day residence time in reactor III. The
residence time of the AMD in a single organic
carbon chamber was approximately 10 hours for
the flow rate of 1 gpm.
Flow through Reactors III and IV has been
maintained as desired for most of the time. The
flow rate through Reactor II, however, started to
decrease in May 1999 and ceased at the beginning
of June. The flow rate was restored in July after
the upgradient cell with organic carbon was
chemically treated to remove biofouling and
associated plugging. Similar behavior of Reactor II
was observed again in May 2000. This time, the
permeability of the upgradient chamber was
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increased using an appropriate physical treatment.
The repetitive plugging events of the most
upgradient chamber in Reactor II seems to be
attributed to a tighter packing of organic carbon in
this chamber in comparison to other chambers.
The performance of each reactor has been
monitored by monthly sampling of the influent
(AMD) and effluent, and continuous monitoring of
selected parameters using appropriate sensors and
data loggers. Water samples have been analyzed
for sulfate; alkalinity; SRB count; heterotrophic
bacteria count; dissolved oxygen; EH; and metals
that include aluminum, zinc, cadmium, copper,
iron, manganese, and cadmium. Temperature,
water level, and flow rate were recorded at 4-hour
intervals by two data loggers. Selected results of
the reactors performance are shown in Figures 11
through 14.
The first 8 months of operation can be described as
a period in which the microbial populations were
becoming established within the reactors. It should
be noted that the reactors were started in the winter
when temperatures were not ideal for microbial
growth. As the reactor temperatures began to
increase in April 1999, an increase in SRB
populations (Figure 11) was also seen. During the
second winter of operation, the well-established
SRB population was not affected by the low
temperatures.
Much of the metals removal observed during the
first 7 months of operation can be attributed to
adsorption. Once sorption sites fill and SRB
populations become established, many metals, like
zinc and copper [(Figures 12 and 13 (logarithmic
scale)] and cadmium (Figure 14), were removed
from the AMD to threshold levels that were
approximately 500 micrograms per liter (jug/L) to
800 fig/L for zinc, 80 jug/L for copper, and 5 jug/L
for cadmium. These removal levels were achieved
despite the relatively low metals-concentrations in
the influent AMD, caused by low atmospheric
precipitation during the last 14 months of
operation. For the metal concentrations present in
the AMD at the Calliope site, the SRB population
above 103 in one milliliter of the treated water was
sufficiently high to maintain these removal levels.
This means that the higher SRB population had no
direct affect on the metal removal levels. This
project will continue through the end of 2001.
SRB Populations
i
12/14/98 3/14/99 6/14/99
Figure 11. SRB populations.
9/14/99 12/14/99 3/14/00
Date
6/14/00 9/14/00
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Zn Concentrations
12/14/98 3/14/99 6/14/99 9/14/99 12/14/99 3/14/00 6/14/00 9/14/00
Date
Figure 12. Concentration of zinc in AMD and reactor effluents.
Cu Concentrations
12/14/98 3/14/99 6/14/99 9/14/99 12/14/99 3/14/00 6/14/00 9/14/00
Date
Figure 13. Concentration of copper in reactor effluents.
Cd Concentrations
12/14/98 3/14/99 6/14/99 9/14/99 12/14/99 3/14/00 6/14/00 9/14/00
Date
Figure 14. Concentration of cadmium in AMD and reactor effluents.
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ACTIVITY III, PROJECT 12A
CALLIOPE MINE INTERNET
MONITORING SYSTEM
Project Overview
The technology addressed in this project is
designed to poll and warehouse remote sampling
data from the Calliope Mine site automatically.
The remote monitoring is linked to the MSB
Technology Application, Inc. (MSB) Testing
Bacility in Butte, Montana, via a cellular modem
connection. Data from the remote site is polled by
a dedicated personal computer (PC) located at the
MSB Testing Bacility. The project also includes
technology to demonstrate remote site monitoring
using two web cameras. The cameras download
images to the PC at the MSB Testing Bacility. The
images and data can be viewed via the Internet
from the dedicated PC.
Technology Description
The polling PC at the MSB site runs software
designed for data loggers at the mine site. This
software has the capability to poll data from the
data loggers on a regular basis. Data is retrieved
from the mine site only once a day since this is a
solar-powered operation and more frequent
retrieval would require a large battery bank. Once
data has been retrieved, it is then transferred to an
industrial database for warehousing. The polling
PC is also connected to the World Wide Web via a
dedicated 56-Kbs frame relay (see Bigure 15).
Once data is stored it can be accessed from
anywhere or any PC that has Internet capability.
An Internet service provider was obtained to allow
the connection as well as provide ample Internet
protocol addresses and domain names for the web
site. The web site domain name for this project is
http;//www.environment-watch.com. Bigure 16
shows the web site home page.
The Web screens were designed to allow anyone
with a PC and Internet access to view information
from the telemetry system. The displays allow
viewing of historical data as well as trending of
data (see Bigure 17).
Two remote cameras are connected to a small on
site camera web server. The server is connected to
the remote cellular modem just like the data
loggers. The polling PC makes three calls to the
mine site daily:
- one call in the morning to download site camera
images of that morning;
- one call in the morning to retrieve data from the
data loggers; and
- one call in the afternoon to download camera
images of the site in the afternoon.
Once the data and the photos are downloaded, data
is warehoused, and pictures are transferred to the
web site for Internet viewing (see Bigure 18).
This project also included the task of upgrading the
existing data logger's battery storage capacity. The
existing In-Situ Hermit 3000 Data Loggers did not
have sufficient battery storage to run data loggers
and existing instruments at specific sample rates.
This problem was solved with the design of a new
solar-powered battery charging system. The solar-
charged batteries now power data loggers,
instruments, the cellular telephone modem, web
cameras, and web camera server.
This project installation has allowed additional
capacity for future Mine Waste Technology
Program projects. These projects can also benefit
by using the same web server to post information
onto the World Wide Web.
Status
As of September 30, 2000, the project was 100%
installed and online. The project will remain open
for maintenance and utility costs of the web server
and other equipment. Maintenance is required for
keeping the web server up to date as well as cover
monthly cell phone and Internet service provider
charges. This project will be closed out once the
Calliope Mine site testing is completed. Possibly,
another Mine Waste Technology Program project
could pick up the monthly costs in the future.
-24-
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Cellular
Antenna
Field Devices
Web
At Calliope Mine Site
Figure 15. Calliope Mine Internet Monitoring System.
File Edit View Favorites Tools Help
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-------
Reactor #3 pH
2rtO.Cn 11.50.00 AM 8/1 £B 6:00:00 PM
5COT 3:00:00 PM 10fllfiO B'OO 00 PM
Figure 17. Historical trends screen for Calliope Mine data on the
Environment-Watch.com web server.
Ete Id! 'l*w FivefBe; led; Help
3
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Figure 18. Web camera images displayed on web server twice daily.
-26-
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ACTIVITY III, PROJECT 13:
HYDROSTATIC BULKHEAD WITH
SULFATE-REDUCING BACTERIA
Project Overview
The technology addressed in this project is
designed to reduce or eliminate acid drainage from
underground mine workings. The demonstration is
intended to illustrate the feasibility of using an
innovative source control technology in a way that
provides increased stability, structural applicability
and continuity, and economical comparability to the
conventional methods of acid drainage treatment
used by the mining and waste industries. The
technology used for this demonstration will be
stable in the environment.
Technology Description
The technology selected for this demonstration is a
combination hydrostatic bulkhead constructed of
concrete and rebar with a colony of sulfate-
reducing bacteria (SRB) placed behind the
bulkhead. The acid drainage in the mine will be
treated by raising the pH of the contained water
behind the bulkhead causing metals to be removed.
The metals removal processes that can occur
include adsorption and complexion of metals by
organic substrates, biological sulfate reduction
followed by precipitation of metals as sulfides,
precipitation of ferric and manganese oxides,
adsorption, adsorption of metals by ferric and
manganese hydroxides, and filtration of suspended
and colloidal materials. Biological sulfate
reduction, however, should be the predominant
metal removal mechanism.
Status
Preliminary design work was completed for
installing a SRB colony behind a bulkhead to be
constructed by the American Smelting and Refining
Company at the Triumph Mine in Triumph, Idaho.
U.S. Environmental Protection Agency (EPA) and
MSB Technology Applications, Inc. (MSB)
personnel reviewed the preliminary SRB design and
agreed that this site was not a viable candidate for
installing a SRB colony due to the presence of
extensive mine workings that would negate adequate
treatment of waters inside the mine.
After eliminating the Triumph Mine as a
demonstration site, the search was resumed for
another site. It was decided by both EPA and MSB
to suspend funding for this project effective fiscal
2001 after additional searching did not locate an
appropriate site for this technology demonstration.
ACTIVITY III, PROJECT 14:
BIOLOGICAL COVER
DEMONSTRATION
Project Overview
Acidic, metal-laden waters draining from abandoned
mines have a significant environmental impact on
surface and groundwater throughout the nation and
the world. Specifically, the State of Montana has
identified more than 20,000 abandoned mine sites,
on both public and private lands, resulting in more
than 1,300 miles of streams experiencing pollution
problems.
Acid mine drainage arises from tailings and waste
rock containing sulfide minerals and lacking acid-
consuming carbonate minerals. Sulfide minerals,
such as pyrite (FeS2), are oxidized to form sulfate
when water containing oxygen infiltrates tailings and
waste rock. This process can be described by the
following reaction:
4BeS2 +15O2 +2H2O - 4Be3+ + 8SO42- +4H+. (1)
The activity of bacteria, such as Thiobadllus
ferrooxidans, which are capable of oxidizing
inorganic sulfur compounds, greatly accelerates this
reaction. The ferric iron (Be3+) produced in the
above reaction also contributes to pyrite oxidation:
FeS2 +14Fe3+ + 8H2O - 15Fe2+ + 2SO42- + 16H+. (2)
T. ferrooxidans is also capable of oxidizing ferrous
iron (Be2+) produced in the above reaction:
4Be2
O2 + 4H+ -4Be3
2H2O.
(3)
-27-
-------
Although the above reaction consumes some
acidity, the ferric iron produced is capable of
oxidizing more pyrite and producing much more
acidity (via reaction 2).
The key to breaking this cycle is preventing the
initial oxidation of pyrite. Bound with iron, the
sulfur in pyrite is unable to participate in the
microbially catalyzed reactions that cause acid
generation. Preventing oxygen infiltration into
tailings and waste rock is necessary to prevent
oxidation of pyrite and subsequent acid generation.
An innovative method to prevent oxygen transport
into tailings is constructing and maintaining a
biologically active barrier on the surface of the
tailings. This barrier is made up of
microorganisms that consume dissolved oxygen
from the infiltrating water, thereby, maintaining the
reducing conditions necessary for pyrite to remain
bound in mineral form.
MSB Technology Applications, Inc. and
researchers at the Center for Biofilm Engineering
at Montana State University are investigating the
microbial processes involved with establishing and
maintaining subsurface and near surface microbial
barriers for hydraulic control and microbially
catalyzed reactions. Biofilm barrier technology has
been successfully tested in laboratory and field-
scale systems where permeability reductions of five
orders of magnitude were achieved. During these
tests, it was also shown that biofilm barriers can
successfully remove oxygen from infiltrating
waters to trace levels.
By conducting this demonstration, the Mine Waste
Technology Program is illustrating the ability of
microbial biomass to reduce the permeability of
mine tailings and remove oxygen from infiltrating
water, thereby, reducing the generation of acid
mine drainage. This technology promises to be a
cost-effective approach for stabilizing and
remediating acid-generating abandoned mine
tailings.
Technology Description
A biologically active zone is established in the
tailings by adding a nutrient solution to the surface
of the tailings pile. The nutrient solution contains
low cost ingredients that serve as sources of carbon
and energy for microbial growth, as well as
sources of nitrogen, phosphorous, and necessary
micronutrients. The nutrient solution is formulated
to stimulate indigenous oxygen-consuming
microorganisms, as well as sulfate-reducing
bacteria (SRB). In some cases, a microbial
inoculum containing appropriate microorganisms
may have to be added. The oxidation of carbon
compounds in the nutrient mixture by
microorganisms depletes oxygen from infiltrating
water. Also, bacterial cells and associated extra-
cellular polymers occupy free pore space within the
tailings matrix, greatly reducing permeability. The
reduction of water volume flowing through the
tailings and depletion of oxygen as water passes
through the barrier will mitigate pyrite oxidation
and subsequent acid generation. The anaerobic
conditions and production of organic acids by
fermentative bacteria will also promote SRB
growth. The SRB activity is desirable because it
neutralizes acid and stabilizes metals by H2S-
mediated metal sulfide precipitation. After
establishing the biological barrier, periodic nutrient
treatments are applied to maintain the barrier.
Status
The Mammoth tailings site in the South Boulder
Mining District, approximately 18 miles from
Cardwell, Montana, was selected for implementing
this technology. Two, lined test cells were
constructed at the field site in the fall of 1999. An
initial nutrient treatment was applied to one of the
test cells (treated cell) in the fall of 1999.
Additional nutrient treatments were applied to the
treatment cell in May, June, and August 2000.
The nutrient formulation included molasses as a
carbon and energy source, urea as a source of
nitrogen, and potassium phosphate. The control
(untreated) cell received an equivalent amount of
water to that applied to the treatment cell during
nutrient treatments. Other than the four nutrient or
water treatments, all water entering the test cells
was due to natural precipitation. The test cells
were not operated during the winter months when
they were frozen.
Drainage from the treatment cell had a slightly
higher pH and slightly lower oxidation reduction
potential than the control cell. The mean pH of
drainage from the test and control cells were 6.4
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and 6.2, respectively. Microbiological analysis
indicated higher populations of total bacteria,
general heterotrophic bacteria, and sulfate-reducing
bacteria in drainage from the treated cell, relative
to the control cell. Populations of sulfur-oxidizing
bacteria (e.g., Thiobadllusferrooxidans) were
similar in drainage from both test cells. Dissolved
sulfate concentrations were lower in drainage from
the treated cell, while total organic carbon
concentrations were higher. Drainage from the
treated cell had lower concentrations of dissolved
aluminum, copper, and zinc and higher
concentrations of iron and manganese than the
control cell. Overall, these results indicate that
treatment with a carbohydrate- (molasses) based
nutrient formulation had a mild effect on the
biological and chemical processes occurring in the
tailings and led to a slight improvement in the
water quality of drainage from the tailings.
Laboratory column tests (described below) have
indicated that protein- (whey) based nutrient
formulation was more effective than the
carbohydrate-based treatment for mitigating acid
mine drainage. During the 2001 field season, a
protein- (whey) based nutrient formulation will be
applied to the treatment cell.
Laboratory experiments performed at the Center
for Biofilm Engineering at Montana State
University have included packed-column tests using
tailings from the Mammoth Field Site, Crescent
Mine (Montana), and the Fox Lake Mine
(Manitoba, Canada). The columns packed with
tailings from the Crescent Mine failed to generate
acidity or significant concentrations of dissolved
metals. Treatment of these columns with the
carbohydrate-based nutrient treatment did result in
a significant decrease in oxidation-reduction
potential (ORP) relative to a control column.
Three columns were packed with tailings from the
Fox Lake site, and two of these received the
carbohydrate-based nutrient treatment, while the
third column served as an untreated control. One
of the treated columns responded with a significant
increase in pH and reduction in OPJ>, as well a
decrease in dissolved aluminum and zinc
concentrations. However, the other treated column
responded with a decrease in pH and an increase in
OPvP. It is hypothesized that the carbohydrate-
based nutrient treatment to this column resulted in
the proliferation of acid-generating fungi. This
hypothesis is being investigated further at the
Center for Biofilm Engineering. Due to the lack of
consistent laboratory results and marginal field
success with the carbohydrate-based nutrient
formulation, a protein-based nutrient formulation
using whey (a by-product of cheese manufacturing)
was applied to columns packed with tailings from
the mammoth site. The whey treatments resulted
in a significant increase in the pH and a decrease in
the OPvP of drainage from the tailings (see Figure
19). This effect was more dramatic and longer
lasting than the molasses treatments performed
previously. The use of whey-based nutrient
treatments is currently being further evaluated in
the laboratory.
Overall, results of laboratory and field testing
indicate that biological cover technology is feasible
for source control of acid mine drainage.
However, the results suggest that correct nutrient
formulation is critical to the success of the
treatment; and in some cases, adding an
inappropriate nutrient formulation can decrease the
water quality of drainage from mine tailings.
Further research is necessary to define the critical
parameters for formulating a nutrient mixture for
treating a specific mine site.
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Mammoth Column
1000 1
E 500
£ 0
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-500
j
" t 4444 i*A*t
Effluent pH, ORP
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10/1/2000 12/1/2000 1/31/2001 4/2/2001 6/2/2001
• whey treated eff. ORP
• • • • whey treated eff. pH -
i control eff. ORP
Figure 19. pH and ORP in effluent from laboratory columns packed with
tailings from the Mammoth Site. The arrows indicate treatment of the
test column with a nutrient solution containing whey as a carbon and
energy source for microbial growth. After a lag period, which represents
the hydraulic residence time of the column, a significant increase inpH
and a decrease in ORP were observed in effluent from the treated
column. This effect was not observed in the untreated control column.
ACTIVITY III, PROJECT 15:
TAILINGS SOURCE CONTROL
Project Overview
Processing metallic ores to extract the valuable
minerals leaves remnant material behind called
tailings. In the case of sulfide mineral-bearing
ores, process tailings often contain large quantities
of sulfide minerals that do not meet the economic
criteria for extraction. These remnant sulfide
minerals are usually pyrites and nonextracted ore
minerals. The exposure of these minerals to air
and water often leads to detrimental environmental
conditions such as increased sedimentation in
surface waters due to runoff events, increased wind
borne paniculate transport, generation of acid mine
drainage, and increased metals loading in surface
and ground waters.
Technology Description
The objective of this demonstration was to identify
potential source control materials and apply one or
more of them at a selected site. The demonstration
consists of two phases: 1) site characterization and
materials testing; and 2) materials emplacement and
long-term monitoring and evaluation.
Phase one consisted of the site characterization
studies, including hydrogeological, geological, and
geochemical information directly related to the
tailings impoundment. The materials testing and
development involved testing, evaluation, and
formulation of source control materials for
application at the selected site.
Phase two will encompass the application of one or
more of the selected source control materials at the
demonstration site and an evaluation of the material
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application and feasibility. Long-term evaluation
of the materials will be performed using air borne
paniculate tests, moisture profiles generated from
monitoring equipment, and post-application
material tests.
Status
For Phase one, the project site selected for this
demonstration is the Mammoth Tailings site located
adjacent to the historic mining town of Mammoth,
Montana (see Figure 20). Material testing was
finalized during the first quarter of 2000. Three
source control materials are scheduled to be applied
at the Mammoth Tailing site, which include two,
polymeric cementitious grouts that incorporate the
tailings material as a filler material and a spray-
applied, modified chemical grout. Due to forest
fire restrictions, the emplacement of the source
control materials was postponed from 2000 to the
summer of 2001. The project will be completed by
the end of calendar year 2001.
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Figure 20. Mammoth Mine Tailings site.
ACTIVITY III, PROJECT 16:
INTEGRATED PASSIVE
BIOLOGICAL TREATMENT
PROCESS DEMONSTRATION
Project Overview
The objective of this project is to develop technical
information on the ability of an integrated passive
biological reactor to treat and improve water
quality at a remote mine site. This technology
offers advantages over many acid mine drainage
(AMD) treatment systems because it does not
require a power source or frequent operator
attention. For this demonstration, the technology
will treat the acidic aqueous waste by removing
toxic, dissolved metallic and anionic constituents
from the water in situ and increasing the pH so the
effluent is near neutral.
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Technology Description
The technology uses a series of biological
processes for the complete mitigation of AMD by
concentrating and immobilizing metals within the
reactors and raising the pH of the water. Both
anaerobic and aerobic bacteria will be used. The
bacteria will be fed inexpensive waste products
such as feed-lot wastes. The anaerobic bacteria,
sulfate-reducing bacteria (SRB), are a group of
common bacteria that are able to neutralize AMD
and remove toxic metals. When supplied with
sulfate (present in mine water) and a carbon
source, SRB produce bicarbonate and hydrogen
sulfide gas. Bicarbonate neutralizes AMD while
hydrogen sulfide gas reacts with metal ions to
precipitate them as insoluble metal sulfides.
Aerobic bacteria will be used to mitigate metals,
such as iron and manganese, that are not removed
satisfactorily by SRB. The result will be an
integrated biological system capable of completely
and passively mitigating AMD. The field system is
depicted in Figure 21.
The first phase of the project will include field site
selection and characterization and laboratory
testing. Laboratory testing will be performed to
identify design parameters for the field design.
Acid Mine
Drainage
1
Compartment 1
Primary
Anaerobic
Reactor
j ^
Compartment 2
Passive
Alkalinity
Addition
I
C
c
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Compartment 3
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Anaerobic
Reactor
c
c
c
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) \
r
") Compartment 4
-^ Aerobic
J Reactor
,
J
)
r
-, Aeration Discharge
Figure 21. Field system for Integrated
Passive Biological Treatment Process
Demonstration
The second phase of the project will include the
design and construction of an integrated passive
biological treatment system to treat AMD at the
selected remote mine site, the Sure Thing Mine
located in Southwest Montana.
Status
The design of the field-scale system was completed
in fiscal 2000. Construction was scheduled during
the summer of 2000 but was postponed because
wild fires caused National Forest closures.
Construction is now scheduled for the summer of
2001.
ACTIVITY III, PROJECT 19:
SITE IN SITU MERCURY
STABILIZATION TECHNOLOGIES
Project Overview
This demonstration project is being conducted in
conjunction with the U.S. Environmental
Protection Agency's Superfund Innovative
Technology Evaluation Demonstration Program.
Mercury contamination often is a critical problem
at mine sites, and there is a recognized need to
identify technologies for mercury remediation.
The application of an in situ mercury stabilization
technology would provide an alternative treatment
to completely removing mercury-contaminated
materials from remote abandoned mine sites. As
part of the overall project, MSB Technology
Applications, Inc. (MSE) is responsible for
conducting technology assessment activities to
comparative mercury stabilization tests using
mercury-contaminated material.
The Sulphur Bank Mine in Clear Lake, California,
was chosen as the source of mercury contaminated
mining wastes for this demonstration project. This
abandoned mine, located in a geothermal active
area, was historically mined for mercury and
sulfur. It is now part of a 120-acre superfund site
containing tailings, rock piles, and a pit lake. The
mine tailings are located upgradient and extend into
and along the shoreline of Clear Lake. The
development of an in situ mercury
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treatment/stabilization technology could be used to
address the significant mercury contamination
problems at the site.
Technology Description
The main objective of this effort is to determine a
suitable method for in situ mercury stabilization.
This technology demonstration project will help to
show the effectiveness of various technologies for
the in situ treatment/stabilization of mercury
contaminated mining materials. Several applicable
technologies will be identified and tested. These
may include chemical precipitation, micro-
encapsulation, and grouting.
Status
MSB is conducting a series of comparative column
treatability tests of various mercury
treatment/stabilization technologies. The
technologies were selected with regards to their
ability to reduce the leaching, mobility, and toxicity
of mercury contamination. Two materials from the
Sulphur Bank Mine site have been selected for
testing. The effectiveness of the treatment
technologies will be evaluated by preforming post-
treatment kinetic column leach tests. The
immobilization of mercury over time and the
reduction of leachable mercury relative to untreated
controls will be determined. The information
gained from this project will serve to provide data
for abandoned mine remediation projects.
ACTIVITY III, PROJECT 20:
SELENIUM
REMOVAL/TREATMENT
ALTERNATIVES
Project Overview
The purpose of the Selenium Removal/Treatment
Alternatives Demonstration Project is to: 1)
evaluate the performance of the selected processes
in the field using selenium-bearing water;
2) evaluate the affect of competing ions on
selenium removal efficiency; and 3) determine full-
scale capital and operating costs of the processes
being demonstrated.
The following selenium removal technologies have
been demonstrated at field-scale: 1) U.S.
Environmental Protection Agency's (EPA) Best
Demonstrated Available Technology (BOAT) for
treating selenium-bearing waters and
coprecipitation of selenium using ferrihydrite as
optimized by MSB Technology Applications, Inc.
(MSB); 2) catalyzed cementation technology
developed by MSB; and 3) biological reduction of
selenium technology developed by Applied
Biosciences Corporation of Park City, Utah. An
enzymatic reduction of selenium technology also
developed by Applied Biosciences Corporation of
Park City, Utah, was demonstrated on a bench-
scale.
The field demonstrations were conducted at
Kennecott Utah Copper Corporation. The influent
water used for the demonstration was a ground
water containing approximately 2 ppm selenium.
The primary objective was to reduce the
concentration of dissolved selenium in the effluent
waters to a level under the National Primary
Drinking Water Regulation Limit for selenium of
50 ppb established by EPA.
Technology Description
Ferrihydrite Precipitation
Ferrihydrite precipitation with concurrent
adsorption of selenium onto the ferrihydrite surface
is the BOAT for treating selenium-bearing waters.
For the coprecipitation to occur, ferric ion (Fe+3)
must be present in the water. Selenate (Se+6) is
removed from the water at pH below 4. The
chemical reaction for ferrihydrite precipitation of
selenium is:
Se+6 + Fe(OH)3(5) + 4H2O- Fe(OH)3(5) + SeO4-2(ad) + 8H+
The ferrihydrite precipitation process is shown in
Figure 22.
Catalyzed Cementation of Selenium
Catalyzed cementation has been developed to
remove arsenic and other heavy metals such as
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thallium and selenium from water. The term
catalyzed cementation describes the process's
ability to remove contaminants from solution by
cementation (adsorption) onto the iron surface. It
is anticipated that the catalyzed cementation
process will have the ability to treat and remove
selenium from solution regardless of its valence
state (+6 or +4). To optimize the cementation
process, proprietary catalysts are added to increase
the removal efficiency of the process. This process
has been shown in similar tests to reduce selenium
concentrations below the Maximum Contaminant
Level of 50 ppb. The catalyzed cementation
process is shown in Figure 23.
Biological Reduction of Selenium
To accomplish biological selenium reduction,
researchers at Applied Biosciences of Salt Lake
City, Utah, have developed a process using baffled
anaerobic solids bed reactors (BASER). The
process is depicted in Figure 24. Selenium
(selenate and selenite) will be reduced to elemental
selenium by specially developed biofilms
containing specific proprietary microorganisms.
This produces a fine precipitate of elemental
selenium. The marketability of the elemental
selenium product will be investigated during this
project. This process is being demonstrated using
equipment designed and constructed by ABC with
assistance from Kennecott Utah Copper
Corporation.
The pilot-scale BASER will be used to investigate
the feasibility of using a defined mixture of
Pseudomonas and other microbes for removing
selenium from influent water.
Enzymatic Reduction of Selenium
Applied Biosciences also demonstrated, at bench
scale, a proprietary enzyme technology for
selenium removal. This metal reducing technology
is based on proprietary enzyme
extraction/purification methods combined with
unique immobilization/encapsulation techniques
that keep the selenium reducing enzyme(s) in a
functional arrangement within an
immobilized/encapsulated matrix. The adaptation,
enhancement, and use of microbial components,
and byproducts (proteins, enzymes, and polymers)
show considerable promise for treatment/removal
of metals and other inorganics in complex
wastewaters. Normal biofilms developed for
selenium reduction and removal can be quickly
overgrown as the bioreactor system is exposed to
waste and process waters containing indigenous
microbes and nutrients. Overgrowth of the
selenium-reducing population in a bioreactor can be
delayed by optimizing the bioreactor and nutrient
selection for the chosen selenium reducer.
However, once nutrients are added, time and
indigenous microbes slowly erode the selenium
reducing capability. This situation can be avoided
by using selenium-reducing enzyme preparations.
Status
The field demonstration of the BDAT technology,
catalyzed cementation, and biological reduction
technology was completed. All three technologies
removed selenium to below the project objective of
50 ppb under optimum conditions. The biological
reduction technology was the most consistent
process tested, with the majority of results less than
the detection limit for selenium of 2 ppb. An
interim report is being drafted and will be
submitted to EPA for review in November 2000.
The laboratory demonstration of the enzymatic
selenium reduction technology was completed.
Although selenium reducing enzymes were
isolated, the unstable nature of them prevented a
pilot-scale demonstration of this technology.
Applied Biosciences is preparing a report about the
laboratory study that will be included in the final
project report. The final report will be submitted
to EPA for review in April 2001. Project closeout
is scheduled for June 2001.
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Reagent 1
Figure 22. Ferrihydrite precipitation process flow diagram.
Rain for Rent 20,000 gallons
Process Water Bulk Storage
To Ferrihydrite
Precipetation ^
System
Reagent 1 W Reagent 2
Sample
Port CC1
Reagent 3
?*y Lime
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1
[
ll1? r
1
c^c>
80 gal
Sample
Port CC2
Sample y
Port CC4
Filter System
iple T
Sample
Port CCS
Sample T 5 Micron 1.0 Micron 0.5 Micron
Port CC4
Filter Press
Sludge J>
Figure 23. Catalyzed cementation process flow diagram.
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Figure 24. Biological selenium reduction process flow diagram.
ACTIVITY III, PROJECT 21:
INTEGRATED PROCESS FOR
TREATMENT OF BERKELEY PIT
WATER
Project Overview
The objective of this project is to develop
integrated, optimized treatment systems for
processing Berkeley Pit water. The Berkeley Pit is
an inactive open-pit copper mine located in Butte,
Montana. Currently containing approximately
30 billion gallons of acidic, metals-laden water, the
Berkeley Pit is filling at a rate of approximately
3 million gallons per day and is a good example of
acid rock drainage.
Two optimized flow sheets will be developed for
this project. One flow sheet is to be oriented
toward minimizing the overall cost of water
treatment to meet discharge requirements—this will
include not only water treatment equipment but also
sludge handling/management. The other flow sheet
is to be oriented toward also meeting discharge
requirements but includes the recovery of products
from the water (copper, metal sulfates, etc.) to
potentially offset treatment costs and result in
overall better economics.
Technology Description
The project will evaluate proven technologies as
well as technologies with credible pilot-scale
supporting data. Technologies with only laboratory
testing history will not be included, which would
include technologies for sludge management,
solid/liquid separation, dewatering, drying, etc., as
well as technologies for product recovery from
water. The goal is to assemble the sequence of
unit operations resulting in the most attractive
overall economics.
Status
A uniform cost estimating approach was developed
and documented to ensure that consistent
assumptions and uniform approaches are used for
all scenarios evaluated. A conceptual design of a
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filter cake repository was completed. This was
important because a repository location had only
recently been established, allowing reasonable cost
estimates to be prepared for the first time. Two
flow sheets were identified to be used as baseline
references with which to compare possible
improvements. An extensive verification effort
was performed to place both reference flow sheets
on the same design basis and perform cost
estimates and economic analyses consistent with the
approach mentioned above. This verification effort
included technical verification as well as economic
verification. A result of the verification effort was
that sludge dewatering was found to be extremely
expensive; since discharge of sludges to the
Berkeley Pit is an option requiring study before
approval, a small-scale test program was conducted
to evaluate the effects of returning settled sludges
to the Berkeley Pit for a 30-year period. Another
significant result of the verification effort was that
the cost of using a strong oxidant for iron oxidation
and removal prior to recovery of other metals was
exorbitant; therefore, other methods for iron
oxidation at low pH were investigated. The most
promising was found to be Inco's sulfur dioxide/air
process used to oxidize cyanide, which was
investigated at bench scale by Inco with very
encouraging results. Various trade studies were
performed, for example, evaluating a high-density
sludge system versus a conventional precipitation
system. An evaluation was performed to evaluate
the feasibility of on-site upgrading of raw products
to increase their marketability and value. For
example, a metal recovered as a carbonate could be
calcined to an oxide, thereby, increasing its grade
and reducing shipping costs.
ACTIVITY III, PROJECT 22:
PHOSPHATE STABILIZATION OF
MINE WASTE CONTAMINATED
SOILS
Project Overview
The project goal is to provide information to
support technical feasibility and regulatory
acceptance of phosphoric acid-based in situ
stabilization of lead in residential soils at the Joplin,
Missouri National Priorities List Site. The ultimate
goal is to demonstrate this technique is a cost-
effective alternative to excavation and haulage of
metal-contaminated soils to a waste repository.
Technology Description
The remediation approach involves mixing
commercial grade phosphoric acid and a trace of
potassium chloride into near surface soils, followed
by pH adjustment (e.g., with lime addition) to
attain paraneutrality. As a result, soluble lead is
converted to pyromorphite, a highly insoluble and
environmentally stable mineral. Subsequently, lead
uptake from rooting zone soils (into aboveground
plant biomass) and into the bloodstream of young
children (from the gastrointestinal tract) is
significantly reduced.
Status
The following project planning documents were
completed in fiscal 2000: Work Plan; Quality
Assurance Project Plan; NEPA Compliance/Site
Access Agreement; and a Health and Safety Plan.
The subcontract with the Missouri Department of
Natural Resources (MDNR), Hazardous Waste
Division, for field and document preparation
support was completed. The subcontract with the
University of Missouri's Veterinary Medical
Diagnostic Laboratory for soils characterization
and pig dosing studies was nearly completed. The
U.S. Environmental Protection Agency (EPA)/Las
Vegas' Environmental Monitoring Laboratory
agreed to perform in vitro assessments of lead
bioaccessibility, as requested by EPA Region 7 and
funded by EPA's Office of Solid Waste and
Emergency Response. MDNR personnel began to
mobilize for the field treatment work in mid-
September 2000.
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ACTIVITY III, PROJECT 23:
REVEGETATION OF MINING
WASTE USING ORGANIC
AMENDMENTS AND EVALUATE
THE POTENTIAL FOR CREATING
ATTRACTIVE NUISANCES FOR
WILDLIFE
Project Overview
The objectives of this project are to demonstrate
the use of organic amendments to enhance the
establishment and growth of grass on lead mine
tailings and to evaluate the affect of those
amendments on plant uptake of metals. Two
sources of compost and an organic fertilizer
derived from municipal sewage treatment plant
sludge were incorporated into two types of tailings
near Desloge, Missouri, and the replicated plots
were planted with grass. Both types of tailings
(fine-textured floatation tailings and course-textured
gravity separation tailings referred to as chat
tailings) contain elevated concentrations of lead,
zinc, and cadmium. This project will be evaluated
for three growing seasons.
Thousands of abandoned mine and mineral
processing sites throughout the United States are
very unattractive and can be a significant
environmental hazard. The federal government
and responsible parties need to develop cost-
effective remedial approaches to effectively
manage these large areas that are contaminated
with a wide variety of metals. Natural revegetation
is often prevented in these areas because of low
pH, phytotoxic concentrations of metals, poor
physical structure for plant growth, nutrient
deficiencies, and slopes too steep for plant
establishment. Mine waste reclamation research
frequently includes the addition of organic soil
amendments, since mine waste materials are
typically subsurface in origin and have minimal
organic content. However, the diversity of organic
amendments used and the lack of uniformity within
each category of material make comparisons among
sites and studies difficult. In addition, while it is
generally agreed that organic amendments are
capable of stabilizing mine waste metals, the
potential for post reclamation impacts to wildlife
due to plant uptake of those metals requires further
research.
Technology Description
MSB Technology Applications, Inc., established
field plots at the Big River Mine Tailings Site and
the Leadwood Chat Tailings Site in Missouri in the
spring of 2000. The plots were evaluated to
determine vegetation establishment, biomass
production, and plant uptake of metals. Procedures
for establishing, maintaining, and evaluating the
plots will be broadly applicable and reproducible so
that subsequent studies at other locations will
produce comparable information. The three organic
amendments are milorganite, ormiorganics
compost, and St. Peters compost. These
amendments were applied at a low, medium, and
high application rate. Each amendment/application
rate combination was replicated four times
including a control plot that only received the
inorganic fertilizer at both sites, totaling 80 plots.
The plant species for the demonstration was tall
fescue (Kentucky variety). The plots were
monitored monthly from May through September
2000. The project will be evaluated for three
growing seasons.
Status
Figure 25 shows the Leadwood Chat Tailings site
prior to planting, and Figure 26 shows the site after
incorporating the organic amendments and 7
months of growth. Figure 27 shows the Big River
Mine Tailings site prior to planting, and Figure 28
shows the site after incorporating the organic
amendments. At the end of the first growing
season, vegetative cover and biomass production
were quantified, and tailings and vegetation
samples were obtained and analyzed. Preliminary
results indicate the amendments improve both
establishment and growth, differences among
amendment types and application rates are
significant, and plant uptake to metals is not great
enough to impact area wildlife. Additional results
of the first growing season will be discussed in an
Interim Report to be issued in March 2001. Project
completion is expected in December 2002.
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Figure 25. Leadwood Chat Tailings site prior to planting.
Figure 26. Leadwood Chat Tailings site after incorporating the organic
amendments.
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Figure 2 7. Big River Mine Tailings site prior to planting.
* 'I
Figure 28. Big River Mine Tailings site after incorporating the organic
amendments.
^*«8k";f'"»*-»i *-*
-------
ACTIVITY III, PROJECT 24
IMPROVEMENTS IN ENGINEERED
BIOREMEDIATION OF ACID MINE
DRAINAGE
Project Overview
Acid mine drainage (AMD) emanates from many
abandoned mine sites in the western United States.
Such drainage, having an elevated content of
dissolved metals and low pH, presents an
environmental problem that needs to be
economically addressed. Sulfate-reducing bacteria
(SRB) have the ability to immobilize dissolved
metals, by precipitating them as sulfides, and
increase pH provided that a favorable biochemical
environment is created. Such conditions may be
created by constructing artificial wetlands, if space
is not limited, or converging the AMD flow to an
engineered passive SRB reactor.
A SRB reactor contains an organic-carbon chamber
that is vital for its operation. A life span of a
properly designed reactor depends on the organic
carbon supply, permeability of organic-carbon
chamber, and the capacity of the reactor to
accumulate precipitated sulfides.
When the source of organic carbon is depleted, or
becomes unavailable, because permeability of the
organic matter decreased due to settling processes
or physical or chemical encapsulation, the
bioreactor will cease operating. To reactivate such
a bioreactor, the organic carbon source has to be
either replenished or rejuvenated. Therefore, it is
desirable to: 1) maximize the time interval
between such operations; and/or 2) be able to
predict the longevity of the carbon source to
economically optimize the reactor's size.
Similarly, when the capacity of the bioreactor's
chamber that was designed to hold precipitated
sulfides is exhausted, the sulfides will either break
through or the reactor will plug ceasing its
operation.
This project addresses engineering improvements
that include replacing the organic carbon supply-
system in a SRB reactor and refining how the
reactor is sized.
Technology Description
Engineered improvements of SRB reactors are to
be accomplished by implementing the four tasks
listed below.
Task I— Selecting Optimal Media with
Organic Carbon
The optimal media needs to: 1) contain a sufficient
amount of organic carbon; 2) be used economically
as passive SRB bioreactors; and 3) have high
potential to be permeable when saturated with
water. Determination of the optimal organic
carbon media will be done through a literature
study. A data base will be set up that will include
the media technical parameters, records of use,
availability, price index, etc.
Task II—Designing a Permeability and
Contact Time Enhancing System
(PACTES)
PACTES will ensure a good supply of organic
carbon and will maintain good permeability of the
organic matter throughout the predicted life of the
reactor.
Task III—Designing an Organic Carbon
Replaceable Cartridge System (PCS)
A replaceable cartridge system will be easy to
install and replace in a bioreactor, particularly at a
remote location.
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To ensure that PACTES and RCS systems are
compatible, their development will be symbiotic.
Work on each system will include the following
phases: 1) developing a list of concepts for each
system; 2) narrowing the list to one or two of the
most applicable solutions; 3) laboratory testing of
the selected solutions; 4) preparing the design
document; 5) constructing the prototype of the RCS
combined with PACTES; and 6) bench-test study
of the constructed prototype.
Task IV—Developing a Computer
Software to Simulate SRB Activities in
the Bioreactor
The software will enable a designer to efficiently
design and size a bioreactor by quantifying the
expected rate of organic carbon depletion and the
volume of SRB activity by-products.
Status
The project was initiated in January 2000 with
efforts focusing on Task I as scheduled. The
literature study resulted in developing a data base,
assembled with Microsoft Access, that included 88
records relevant to using various organic
substances as an organic carbon source for SRB.
A review of the records revealed that there have
been more than two dozen organic media used for
providing organic carbon for SRB. A rating of
these media according to their efficiency indicates
that compost, food product sewage, cow manure,
and poultry waste are most suitable to supply
organic carbon for SRB. Nevertheless, other
factors like availability and cost must be taken into
consideration when selecting organic carbon for the
given location. Based on these conclusions, cow
manure was recommended to be used as the
organic carbon source for the efforts that will be
implemented in Tasks II, III and IV.
By the end of fiscal 2000, Task II was advanced
through the development of concepts for the
PACTES using a mixture of cow manure
prepacked in plastic-net socks, approximately one
cubic foot in volume. Two kinds of mixtures are
currently being considered: 1) cow manure with
walnut shells; and 2) cow manure with strips of
corrugated plastic and pumice stone. Walnut shells
and corrugated plastic will increase the
permeability and prevent settling of the mixture. In
addition, walnut shells and pumice stone will
provide a solid matrix for SRB growth.
Task III was also advanced to the development of
concepts for the RCS that currently include a
pattern of pipes filled with PACTES. The pipes
will be placed in a container through which the
AMD will flow in a vertical direction collinear
with the axes of the pipes.
Initial work on Task IV identified an existing
software, MINTEQAK, that was developed to
simulate biochemical processes occurring in
wetlands. This software must be modified to
enable input of variables for the time and spatial
coordinates.
Work on the project will continue into fiscal 2002.
ACTIVITY IV OVERVIEW
The objective of this activity is to develop, qualify,
and screen techniques that show promise for cost-
effective remediation of mine waste. The most
promising and innovative techniques will undergo
bench- or pilot-scale evaluations and applicability
studies to provide an important first step to full-
scale field demonstrations. Each experiment is
assigned as an approved project with specific goals,
budget, schedule, and principal team members.
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ACTIVITY IV, PROJECT 11:
PIT LAKE SYSTEM
CHARACTERIZATION AND
REMEDIATION FOR BERKELEY
PIT-PHASE II
Project Overview
An interdisciplinary team of Montana Tech
researchers is currently studying several aspects of
the Berkeley Pit Lake system to better understand
the system as a whole, which may lead to new or
improved remediation technologies to be used
during future cleanup. The information obtained
from the studies will be used to predict future
qualities of the water, to evaluate the natural rate of
remediation, to determine if partial in situ
remediation may be practical prior to expensive
pump and treat remediation, and to predict water
quality for similar bodies of water in the United
States. The following research is being conducted
on the Berkeley Pit lake: Water/Wall Rock
Interactions; Bioremediation of the Berkeley Pit
Lake System; and Tailings Deposition into the
Berkeley Pit.
Technology Description
Organic Carbon in Berkeley Pit
Sediments
Late in 1997, the Mine Waste Technology Program
funded several projects to chemically and
physically characterize the Berkeley Pit Lake water
as a function of depth at several positions within
the pit. Reports on this work are being prepared
for the Berkeley Pit Characterization Project, Mine
Waste Technology Program Activity IV, Project 8.
The section, Analyzing Organic Substances in the
Berkeley Pit Water, has demonstrated that the
organic carbon content of the water is
approximately 2 to 3 ppm. There appears to be
some minor changes in total organic carbon (TOC)
concentration as a function of depth in the pit lake.
Considering the sources of water for the pit lake
and the similar concentrations of TOC in the in-
flow and pit lake waters, it is reasonable to assume
that the organic material in the water of the
Berkeley Pit Lake is typical of alpine ground and
surface waters. Although not yet identified
directly, it is also reasonable to assume that a major
fraction of the TOC is humic material. Humic
substances are well known to be important factors
in controlling the chemistry of aquatic ecosytems.
Humic material bind hydrogen ons, metal ions, and
other organic compounds; adsorb strongly at
aqueous/solids interfaces; and participate in the
redox and photochemistry of surface waters.
Wall Rock/Water Interactions
To understand the processes of water-rock
interaction in the pit environment, we need to know
more about the mineralogy of the pit walls and how
these minerals interact with rain water, oxidized
(shallow) pit water, and reduced (deep) pit water.
The main objectives of this project are: 1) to
collect a suite of samples from the north high wall
of the Berkeley pit, focusing on material that
contains abundant secondary minerals (post mining
oxidation products); 2) to collect a suite of samples
from the walls of the Lexington tunnel (e.g.,
dripstones forming at acid rock drainage seeps); 3)
to characterize the mineralogy of these samples by
the scanning electron microscopy/energy dispersive
spectrometer and x-ray diffraction; and 4) to
interact selected samples with distilled water,
oxidized pit water, and reduced pit water to
document changes in solution chemistry (e.g., pH,
metal concentration) and solid mineralogy with
time.
Bioremediation of the Berkeley Pit Lake
System
Very little is known about the organisms that are
impacted by mine waste in the Berkeley Pit Lake
system. It is known that if heterotrophic and
autotrophic organisms are properly nutrified, they
can bioremediate mine waste-influenced areas as a
benefit of their physiological processes.
However, before any type of bioremediation of an
ecosystem can begin, it is essential to gain a
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fundamental understanding of the components of
the microbial community. Defining the baseline
community structure is the first step toward
understanding the interaction of the different biota
and toward assessing any improvement in
biodiversity within the biotic community. Progress
toward this understanding has been made clearer by
previous research.
Tailings Deposition into Berkeley Pit
One potential course of action of ongoing Montana
Resources operation adjacent to the Berkeley Pit is
to deposit tailings into the Berkeley Pit instead of
pumping them up to the Yankee Doodle Tailings
Pond. As a result, a high pH tailings slurry would
be mixed with the low pH Berkeley Pit water. The
exact result of tailings deposition into the Berkeley
Pit is not
clear. This research will focus on three main
areas: 1) water quality of Berkeley Pit water as
tailings are deposited; 2) long-term stability of
tailings/water mixture; and 3) long-term stability of
tailings alone.
Status
Organic Carbon in Berkeley Pit Sediments: Total
organic carbon concentrations are significantly
higher in the sediments than in the water column.
The source of the organic carbon must still be
determined.
Wall Rock/Water Interactions: Humidity cell tests
using wall rock from the Berkeley Pit and distilled
water produce effluents very similar to the water
currently in the Berkeley Pit in terms of dissolved
metals concentrations.
Bioremediation of the Berkeley Pit Lake System:
Significant dissolved metal concentrations were
observed after algae found in Berkeley Pit water
were grown in optimum conditions. This is
important information for future in-situ remediation
strategies that may be employed at the Berkeley
Pit.
Tailings Deposition into Berkeley Pit: Limed
tailings, when added to Berkeley Pit water on a 1:1
ratio (volume), significantly raise the pH and lower
the dissolved metal concentrations, while
backfilling the pit at the same time.
This project was completed, and the final report is
being prepared.
ACTIVITY IV, PROJECT 12: AN
INVESTIGATION TO DEVELOP A
TECHNOLOGY FOR REMOVING
THALLIUM FROM MINE
WASTEWATERS
Project Overview
The thallium literature review was conducted as a
necessary precursor study under the Mine Waste
Pilot Program Activity I Issues Identification and
Technology Prioritization Report to determine
whether a pilot-scale demonstration of thallium
removal should be performed. A similar review for
arsenic (Mine Waste Pilot Program Activity I Issues
Identification and Technology Prioritization Report:
Arsenic) resulted in a very successful pilot scale
demonstration of three arsenic removal
technologies. Thallium removal technologies are
not developed to the same state of the art as the
arsenic removal technologies. Therefore, the
conclusion is that further laboratory bench-scale
test work and development are required before
pilot-scale demonstrations are performed by MSB
Technology Applications, Inc.
This research is being conducted in response to the
need for bench-scale laboratory investigations to
develop appropriate thallium removal technologies
prior to a pilot-scale demonstration project. The
question is, what technologies may be appropriate
for removing thallium to levels of 1.7 ppb? Two
technologies that may be able to meet the proposed
thallium level are proposed for laboratory bench-
scale experimental study, e.g., manganese dioxide
adsorption (readily available as a waste product
from zinc electrowinning operations) and reductive
cementation of thallium utilizing elemental iron (a
relatively inexpensive reagent available in scrap
form).
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Status
Preliminary research has begun. The project will
be completed in March 2001
ACTIVITY IV, PROJECT 14
ARTIFICIAL NEURAL NETWORKS
AS AN ANALYSIS TOOL FOR
GEOCHEMICAL DATA
ACTIVITY IV, PROJECT 13:
SULFIDE COMPLEXES FORMED
FROM MILL TAILINGS PROJECT
Project Overview
No investigation has been conducted of the
reactions occurring in the reduced zone of a tailings
heap. Generally, it is believed that any metal
oxides that are mobilized in the upper oxidized
zone will be reprecipitated as sulfides in the lower
reducing zones of the tailings. Numerous metal
sulfides exist and may be formed in this reducing
zone of the tailings. These complexes may be
mobilized as the reduction-oxidation (redox)
potential changes within the tailings. In the
Berkeley Pit, if tailings are deposited into the Pit
lake, and the system's redox potential changes over
time, any metal sulfide complexes could be
mobilized and enter the deep aquifer surrounding
the Pit.
Project Overview
This project applies to artificial neural network
(ANN) analysis of geochemical and similar data
sets, such as those acquired from the Berkeley Pit
in Butte, Montana. There are two main types of
ANN, supervised and unsupervised networks, and
both lend themselves to analyses of this nature.
Supervised networks are used in conjunction with
or in place of conventional prediction models.
They require sets of known inputs and target results
or measurements. Unsupervised networks serve a
useful function as data mining tools. They do not
require pairs of input/target values but instead
make an unbiased determination of groups or
clusters that occur in the data.
Status
Preliminary work has begun. The project will be
completed in March 2001.
Status
Preliminary work has begun. The project will be
completed in March 2001
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ACTIVITY IV, PROJECT 15
IMAGING SPECTROSCOPY-AN
INITIAL INVESTIGATION
Project Overview
This research project will be done in phases. The
first task is to conduct a comprehensive literature
search of imaging spectroscopy and its application
to mining and mine waste. If the technology is
found to be viable for characterizing mining-
impacted areas, a second phase project may be
funded.
Status
Minimal progress was made on this project due to a
sabbatical taken by the principle investigator.
Work is planned to begin in fiscal 2001.
ACTIVITY IV, PROJECT 16
PIT LAKE SYSTEM
CHARACTERIZATION AND
REMEDIATION FOR BERKELEY
PIT-PHASE III
Project Overview
This research project is designed to study and
characterize several aspects of the Berkeley Pit
lake system to gain a better understanding of the pit
lake systems. The information obtained from the
Berkeley Pit lake research will be used to
predict future qualities of the water, to evaluate the
potential for natural remediation, to determine if
partial in-situ remediation may be practical prior to
pump and treat remediation, to develop new or
improved remediation technologies, and to predict
water quality for similar bodies of water in the
United States. The following areas of research and
testing for the Berkeley Pit lake have been
determined: Humic Remediation Potential; Algal
Remediation of Berkeley Pit Water; Berkeley Pit
Aquifer Modeling; and Remediation by
Photocatalysis.
Technology Description
Humic Remediation Potential
Humic substances have widely varying chemical
compositions and molecular weights. These
substances are generally acidic and are considered
to be polymeric in structure. Humic materials are
produced by the biological and chemical
degradation of plant and animal matter and are
often operationally separated into two water-soluble
fractions, fulvic acids, and humic acids. The
distinction between these two groups is a result of
different molecular-weight ranges, solubilities, and
the separation procedure used. The fulvic acid
group has the lower molecular-weight range and
higher water solubility. Chemical analyses of
humic materials has consistently demonstrated the
presence of a large fraction of aromatic material
and carboxylic acid and phenolic functional groups.
These oxygenated functional groups are responsible
for the strong binding of the humic materials to
mineral surfaces and the binding of metal ions in
aqueous solutions.
Algal Remediation of Berkeley Pit Water
Ongoing research is beginning to help us
understand the microbial ecology of the Berkeley
Pit Lake System, with ever increasing information
becoming available regarding the diversity of
algae, protistans, fungi and bacteria that inhabit this
mine waste site. Defining the baseline community
structure has been the first step not only toward
understanding the interactions of the different
groups of organisms but also toward assessing any
improvement in biodiversity within the biotic
community. Now that this first step has begun, this
research will investigate how some of these
extremophiles, specifically algae, that have been
isolated from the Berkeley Pit Lake System may be
used as a potential solution for bioremediation.
The primary goal of this study is to determine the
potential utilization of algae for bioremediation of
the Berkeley Pit Lake System.
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Berkeley Pit Aquifer Modeling
The water level in the Berkeley pit has risen a little
more than 1 foot per month for the last several
years. There are several sources of ground water
and a range of ground-water qualities entering the
pit: a) contaminated ground water from the
underground workings in the bedrock aquifer west
of the pit; b) uncon-taminated ground water from
the bedrock aquifer east and southeast of the pit;
and c) contaminated alluvial ground water from
east and south of the pit. At a water-depth of 850
feet, the rising water in the pit is presently not in
contact with the alluvial aquifer, but rather,
seepage faces have formed along the rim of the pit
near the bedrock-alluvium contact. The rising
water level in the pit will reach a depth of about
1,150 feet (100 feet above the bedrock-alluvial
contact) before controls will be implemented.
Presently, a ground-water divide exists roughly
coincident with Continental Drive between the
Berkeley Pit and the Butte valley. Ground water
and surface water north of the divide flow into the
pit while ground water and surface water south of
the divide flow into the Metro Storm Drain and
ultimately into Silver Bow Creek. As the pit water
level rises above the bedrock-alluvium contact, the
ground-water gradient toward the pit will decrease,
possibly shifting the ground-water divide south of
the pit, thereby, diverting a portion of the ground
water now flowing into the pit to the Butte valley.
This would manifest itself as an increase in water
levels throughout the residential area south of the
pit and a flow increase in the metro storm drain.
Remediation by Photocatalysis
Numerous technologies are available for
remediating acid rock drainage. These
technologies include biosorption, mineral/resin
adsorption, chemical precipitation, ion exchange,
freeze crystallization, evaporation, and a host of
others. Several of these technologies have been
tested over the past decade on Berkeley Pit Lake
water. Lime precipitation became recognized as
the U.S. Environmental Protection Agency's Best-
Determined Available Technology for remediating
the Berkeley Pit water. However, the conventional
process had to be modified to meet discharge
standards regarding pH and manganese and
aluminum concentrations. The resulting two-stage
process required an intermediate filtration step to
remove precipitates that would redissolve upon
continued lime addition.
In a previous study funded by the Mine Waste
Technology Program, a process was developed for
remediating Berkeley Pit water while
simultaneously recovering the copper and zinc and
producing other marketable products. This process
uses a combination of the technologies listed above
but has a novel approach for using ultraviolet
radiation to meet the objectives. As indicated, the
process uses five stages to selectively remove
various metal constituents in the water by
precipitation. Solid/liquid separations between the
individual stages allows for the precipitates to be
recovered and eventually marketed. Furthermore,
the process also meets the discharge requirements
of the metals including that of arsenic.
Status
Preliminary work has begun. The project will be
completed in March 2001.
ACTIVITY V OVERVIEW
TECHNOLOGY TRANSFER
This activity consists of making technical
information developed during Mine Waste
Technology Program (MWTP) activities available
to industry, academia, and government agencies.
Tasks include preparing and distributing MWTP
reports, presenting information about MWTP to
various groups, publications in journals and
magazines, holding Technical Integration
Committee meetings, sponsoring mine waste
conferences, and working to commercialize
treatment technologies.
Fiscal Year Highlights
• The MWTP Annual Report was published
summarizing fiscal year accomplishments.
similar report will be published each year.
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1 Several MWTP professionals appeared at varied
meetings to discuss the Program with interested
parties. Many mine waste conferences, as well
as mining industry meetings, were attended.
ACTIVITY VI OVERVIEW
TRAINING AND EDUCATION
Through its education and training programs, the
Mine Waste Technology Program (MWTP)
continues to educate professionals and the general
public about the latest information regarding mine
and mineral waste cleanup methods and research.
As a result of rapid technology and regulatory
changes, professionals working in the mine- and
mineral-waste areas often encounter difficulties in
upgrading their knowledge and skills in these
fields. In recent years, the environmental issues
related to the mining and mineral industries have
received widespread public, industry, and political
attention. While knowledge of current research
and technology is vital for dealing with mine and
mineral wastes, time and costs may prevent
companies from sending employees back to the
college classroom.
Through short courses, workshops, conferences,
and video outreach, Activity VI of MWTP
educates professionals and the general public and
brings the specific information being generated by
bench-scale research and pilot-scale technologies to
those who work in mine- and mineral-waste
remediation.
Fiscal 2000 Highlights
• The Mine Design, Operations, and Closure
Conference 2000, conducted in April 2000,
continued last year's interagency cooperation.
The 5-day event was cosponsored by the U.S.
Forest Service; U.S. Bureau of Land
Management; Montana Department of State
Lands; MSB Technology Applications, Inc.;
Haskell Environmental Research Studies
Center; several other private companies; and
Montana Tech. During the conference, experts
presented overviews on such topics as predictive
chemical modeling for acid mine drainage, mine
water quality source control, state-of-the-art
containment technologies, and innovative pit
reclamation. Over 130 mine operators,
consultants, and professionals from the private
and public sectors attended the conference.
The Mine and Mineral Waste Emphasis Program
has an enrollment of 10 students with all of them
receiving funding from MWTP. This is an
interdisciplinary graduate program that allows
students to major in their choice of a wide
variety of technical disciplines while maintaining
an emphasis in mining and mineral waste.
A group of Mine and Mineral Waste Emphasis
graduate students attended the Mine Design,
Operations, and Closure Conference 2000.
A cooperative agreement is in place for work
with the Haskell Environmental Research
Studies Center at Haskell Indian Nations
University.
Graduate students in the Mine and Mineral
Waste Emphasis Program are working on
projects in Activities IV.
As part of the Native American Initiative,
Montana Tech presented five short courses:
Mining and the Environment at Fort Belknap,
and Acid Rock Drainage at both Fort Belknap
and Salish Kootenai College. An environmental
learning community was set up to house the
short courses and Web courses to make them
accessible to Native American communities
around the country. One Web course,
Environmental Planning for Small Communities,
is on-line.
Future Activities
The following training and educational activities
are scheduled for 2001:
• MWTP Training and Educational activities will
offer the Mine Design, Operations, and Closure
Conference 2001 in April 2001.
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MWTP is working on a cooperative education
package for the Montana Department of
Environmental Quality.
All funded Mine and Mineral Waste Emphasis
Program graduate students will work on mine
waste-oriented projects as a part of their funding
requirements.
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FINANCIAL SUMMARY
Total expenditures during the period October 1,
1999, through September 30, 2000, were
$5,776,987, including both labor and nonlabor
expense categories.
The cumulative authorized funding for the period
was $9,475,048.
Individual activity accounts are depicted on the
performance graph in Figure 29.
$6,000,000 -,
$5,000,000 -
$4,000,000 -
$3,000,000 -
$2,000,000 -
cn
• FY-2000 Costs
Mine Waste Technology Program
FY-2000 Cost Per Activity
MWTP
$5,776,987
«
Activity 1
$287,024
Activity II
$0
I 1 I I
Activity III Activity IV Activity V Activity VI General
$3,312,649 $512,622 $258,152 $407,725 $998,816
Figure 29. Mine Waste Technology Program fiscal 2000 performance graph, costs per activity.
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COMPLETED ACTIVITIES
ACTIVITY III, PROJECT 1:
REMOTE MINE SITE
DEMONSTRATION
Project Overview
Acidic metal-laden water draining from remote,
abandoned mines has been identified by the U.S.
Environmental Protection Agency (EPA) as a
significant environmental hazard to surface water
in the western United States. In Montana alone,
more than 3,000 such sites have been identified,
and wastes from these mines have damaged over
1,100 miles of surface water in the State.
EPA asked MSB Technology Applications, Inc.,
to develop a treatment facility at one of these sites
to treat acidic metal-laden water. Due to the
remote nature of these locations, this facility was
required to operate for extended periods of time
on water power alone, without operator
assistance.
The Crystal Mine, located 7 miles north of Basin,
Montana, is an example of a remote mine site
with a point-source aqueous discharge, which
made it an ideal site for this demonstration. In
addition, the site had been identified by the
Montana State Water Quality Bureau as a
significant contributor of both acid and metal
pollution to Uncle Sam Creek, Cataract Creek,
and the Boulder River. This project demonstrated
a method for alleviating nation-wide
environmental problems associated with remote
mine sites.
Technology Description
The Crystal Mine demonstration treated a flow of
water ranging from 10 to 25 gallons per minute,
approximately half of the total mine discharge.
The process consisted of the following six unit
operations:
• Initial Oxidation—atmospheric oxygen partially
oxidizes ferrous iron to the ferric form.
• Alkaline Addition—reagents form metal
hydroxide solids.
• Secondary Oxidation—atmospheric oxygen
oxidizes additional ferrous iron to the ferric
form.
• Initial Solid/Liquid Separation—settling ponds
trap precipitated solids.
• pH Adjustment—atmospheric carbon dioxide
lowers the pH.
• Secondary Solid/Liquid Separation—settling
pond retains additional precipitated solids.
Results
The Remote Mine Site Demonstration Project at
the Crystal Mine was conducted in the field for
2 years under all weather conditions.
Construction of buildings, ponds, and associated
mine site infrastructure began in late May 1994
and was completed in early August 1994. Acid
mine drainage from the lower portal of the Crystal
Mine began passing through the system on a full-
time basis in early September 1994. Analytical
data from the project showed a greater than 75%
removal of toxic metals from the mine drainage.
The project was closed out, and the final report
was published.
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ACTIVITY III, PROJECT 2:
CLAY-BASED GROUTING
DEMONSTRATION
Project Overview
Surface and ground water inflow into
underground mine workings becomes a significant
environmental problem when water contacts
sulfide ores, forming acid drainage. Clay-based
grouting, the technology selected for this
demonstration, has the ability to reduce or
eliminate water inflow into mine workings by
establishing an impervious clay curtain in the
formation.
Technology Description
Ground water flow is the movement of water
through fissures and cracks or intergranular
spaces in the earth. With proper application,
grout can inhibit or eliminate this flow.
Grouting is accomplished by injecting fine-grained
slurries or solutions into underground pathways
where they form a ground water barrier. The
Ukrainian clay-based grouting technology was
selected for testing and evaluation because it
offered a potentially long-term solution to acid
mine drainage problems.
Clay-based grouts are visco-plastic systems
primarily comprised of structure-forming cement
and clay-mineral mortar. When compared to
cement-based grouts, clay-based grouts offer the
following advantages: better Theological
characteristics, greater retention of plasticity
through the stabilization period, and less
deterioration during small rock movement.
Results
The Mike Horse Mine near Lincoln, Montana,
was the project site. A major factor in the site
selection was an identified point-source flow from
Mike Horse Creek into the mine causing acid
drainage that could potentially be controlled using
grouting technology.
Approximately 1,600 cubic yards of clay-based
grout were injected into the fracture system
adjacent to the Mike Horse Mine. The grout was
pumped into boreholes using packers to ensure the
proper placement of grout at selected intervals.
Grout injection was initiated in September 1994
and was completed in November 1994. A second
phase of grout injection was planned for the
summer of 1995; however, high water dammed
up within the mine caused extensive damage to
the mine and to the monitoring stations used for
the demonstration. As a result, Phase Two was
discontinued.
From the minimal amount of monitoring data that
was collected, it was determined that the total
discharge from the mine was reduced by
approximately 30%.
The final report was published.
ACTIVITY III, PROJECT 4:
NITRATE REMOVAL
DEMONSTRATION
Project Overview
The presence of nitrates in water can have
detrimental effects on human health and the
environment. Nitrates may be present in mine
discharge water as a result of mining or other
industrial activities.
To comply with federal and state water quality
standards, mining companies have typically used
ion exchange or reverse osmosis to remove
nitrates from discharge water. However, both are
expensive and generate a concentrated nitrate
wastestream requiring disposal.
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Technology Description
Mine Waste Technology Program (MWTP)
personnel undertook an extensive search to
evaluate innovative nitrate removal technologies.
Of the twenty technologies screened, the
following three showed the most promise in
making nitrate removal more economical and
environmentally responsible:
- ion exchange with nitrate-selective resin;
- biological denitrification; and
- electrochemical ion exchange (EIX).
MWTP personnel believed the best solution to the
nitrate problem was some combination of the
three technologies that balanced capital costs with
operating costs, reliability, and minimization of
wastestreams requiring disposal. Each
combination had advantages and disadvantages
that were addressed during the project.
Results
The Nitrate Removal Demonstration Project was
conducted at the TVX Mineral Hill Mine near
Gardiner, Montana. Conventional ion exchange
was used to remove nitrate from the mine water
and produce a concentrated brine for additional
testing. Biological denitrification units and an
EIX unit were used to process both mine water
and concentrated nitrate brine.
The goals of the project were to remove nitrate to
less than 10 milligrams per liter (mg/L) of nitrate-
nitrogen (NO3-N) in the effluent and to minimize
the amount of waste produced. Of all the
technology combinations tested, biological
denitrification of concentrated nitrate brine was
the most successful at meeting these goals.
The nitrate ion exchange (NIX) unit was produced
by Altair, Inc. As expected, the NIX unit worked
well and removed nitrate from the mine water
very effectively. Input levels of 20 to 40 mg/L
NO3-N were typically reduced to less than
1 mg/L. The unit also produced a concentrated
brine with high levels of nitrate and chloride.
Frequent equipment shutdowns and muddy mine
water did not affect the operation of the NIX unit.
Biological denitrification was performed on both
mine water and concentrated brine. This process
worked well to eliminate nitrate in brine. Except
for two process upsets, nitrate was removed to
levels less than 10 mg/L NO3-N. This removal
rate met the project goals and was typically
greater than 99%.
Biological denitrification of the raw mine water
was less successful. A removal rate of
approximately 50% was typically achieved. This
data was taken from an operating denitrification
reactor at the mine. Past data had shown that this
reactor was very effective at nitrate removal.
Apparently, the frequent shutdowns and startups
had a detrimental effect on these reactors.
The electrochemical ion exchange unit was built
be Selentec, Inc. Electrochemical ion exchange
was unsuccessful at removing much nitrate from
the concentrated brine because of the presence of
high concentrations of a competing
anion—chloride.
Electrochemical ion exchange was able to remove
nitrate from the raw mine water more effectively
than from the brine. Nitrate was removed at first;
however, fouling of the resin by dirty water
occurred quickly, and the process was rendered
ineffective after one batch. Filters were installed,
but the nature of the particles made filtration
difficult.
The final report was published.
ACTIVITY III, PROJECT 5:
BIOCYANIDE DEMONSTRATION
Project Overview
The primary use of cyanide in the mining industry
is to extract precious metals from ores. The use
of cyanide has expanded in recent years due to
increased recovery of gold using heap leach
technologies. Cyanide can be an acute poison and
can form strong complexes with several metals,
resulting in increased mobility of those metals.
As such, cyanide in mine wastewater can
contribute to environmental problems.
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These potential problems have led to the
development of several methods to destroy
cyanide and cyanide complexes in mining
wastewater. Most of these processes use
chemicals to oxidize the cyanide and produce
nontoxic levels of carbon dioxide and nitrogen
compounds, which are relatively expensive to
operate.
Technology Description
Biological destruction of cyanide compounds is a
natural process that occurs in soils and dilute
solutions. To take advantage of this natural
destruction, a strain of bacteria was isolated by
researchers at Pintail Systems, Inc. This bacteria
has been tested on cyanide-contaminated mine
waters and has shown degradation rates of over
50% in 15 minutes.
The main goal of this project was to use a strain
of bacteria to destroy cyanide associated with
precious metal mining operations. Another
project goal was to develop a reactor design that
would best use the cyanide-degrading effects of
the bacteria to destroy cyanide from mining
wastewater.
The field demonstration portion of the project was
located at the Echo Bay McCoy/Cove Mine,
southwest of Battle Mountain, Nevada. The
mining rate at the mine exceeds 160,000 tons of
ore per day. Milling of high-grade and sulfide
ores occurs simultaneously with the cyanide
solution heap leaching of lower grade ores. These
cyanide solutions contain 500 to 600 mg/L of
weak acid dissociable (WAD) cyanide with other
contaminants, such as arsenic, copper, mercury,
selenium, silver, zinc, and nitrate.
A bioaugmentation phase was initiated to isolate
organisms and select the ones that degrade
cyanide most effectively. To initiate the project,
Pintail Systems, Inc., collected water samples
from the mine site to isolate indigenous organisms
capable of effectively degrading cyanide and
performed bioaugmentation studies at their
Colorado laboratory. During the bioaugmentation
phase, the bacteria were subjected to increasing
concentrations of cyanide to select the most
capable organisms.
The bacteria selected during the bioaugmentation
process were then placed on fixed growth media
in bench-scale reactors. Next, actual cyanide
mine water was processed through the reactors to
study the kinetics of cyanide degradation. The
results from these tests were used to design the
pilot-scale reactors to be used at the mine. The
process train consisted of tanks where the aerobic
and anaerobic bacteria were grown in large
quantities. The bacteria were then pumped to the
reactors for reinoculation. The cyanide solution
entered the aerobic reactor first where aerobic
organisms degraded a large portion of the
cyanide. The solution then moved through a
series of anaerobic units for further degradation.
Finally, an aerobic polishing step removed the last
traces. Since cyanide is known to degrade by
mechanisms other than biological, a series of
control reactors was installed to run concurrently
with the biological reactors.
Testing of the pilot-scale unit was performed
during the summer of 1997. Cyanide and heavy
metals were substantially removed from the mine
process water. The pH was consistently
neutralized. A preliminary scale-up cost estimate
indicated substantial savings over conventional
technologies. The final report was published.
Results
In fiscal 1996, a field-scale unit was constructed
at the McCoy/Cove Mine to degrade cyanide in
an existing process stream. The unit was
designed to reduce the WAD cyanide
concentration from 500 mg/L to less than
0.2 mg/L at flow rates of approximately 1 gallon
per minute.
ACTIVITY III, PROJECT 6:
POLLUTANT MAGNET
Project Overview
Personnel from the U.S. Environmental
Protection Agency's National Risk Management
Research Laboratory forwarded this project to the
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Mine Waste Technology Program (MWTP). The
concept of the pollutant magnet was to develop,
produce, and test particles that have specific
magnetic properties and have the ability to remove
specific pollutants from a wastestream. After
program personnel reviewed the project, it was
dropped from MWTP due to its similarity with
competing technologies that were more developed
and had a nonmining specific use.
ACTIVITY III, PROJECT 7:
ARSENIC OXIDATION
Project Overview
The Arsenic Oxidation Project was proposed to
demonstrate and evaluate arsenic oxidation and
removal technologies. The technology being
demonstrated during this project was developed
jointly by the Cooperative Research Center for
Waste Management and Pollution Control Limited
and the Australian Nuclear Science & Technology
Organization (ANSTO) from Lucas Heights
Research Laboratories in Lucas Heights, New
South Wales, Australia.
Arsenic contamination in water is often a by-
product of mining and the extraction of metals
such as copper, gold, lead, zinc, silver, and
nickel. This contamination will continue to grow
as high-grade ores with low arsenic content are
being depleted and the processing of sulphide ores
with high arsenic content becomes increasingly
common. In most cases, it is not economical to
recover the arsenic contained in process streams
because there is little demand worldwide for
arsenic. Arsenic can be present in leachates from
piles of coal fly ash, in contaminated ground
waters, in geothermal waters, and in acid drainage
from pyritic heaps resulting from the past
practices of mining metallic ores.
Trivalent arsenic, arsenite, or As+3 compounds
have been reported to be more toxic than the
corresponding pentavalent arsenic, As+5 or
arsenate forms, and much more difficult to
remove from solution. Consequently, there is a
need to convert As+3 to As+5 to achieve effective
arsenic removal from solution.
Technology Description
The small-scale pilot project demonstrated a two-
step process for removing arsenic from
contaminated mine water. The first step and
primary objective of this project was to evaluate
the effectiveness of a photochemical oxidation
process to convert dissolved As+3 to As+5 using
dissolved oxygen as the oxidant. The technology
provides a method for the oxidation of As+3 in
solution by supplying an oxidant, such as air or
oxygen, and a nontoxic photo-absorber, which is
capable of absorbing photons and increasing the
rate of As+3 oxidation to the solution. The photo-
absorber used is economical and readily available.
Ultraviolet oxidation using high-pressure mercury
lamps and solar energy was tested. The second
step of this project resulted in removing As+5
from the solution by using an accepted U.S.
Environmental Protection Agency method,
adsorption using ferric iron.
Results
The field demonstration and final report were
completed. The photochemical oxidation process
was very effective at oxidizing arsenite to arsenate
at optimum conditions in the batch mode for both
the solar tests and the photoreactor tests;
however, design problems with the photoreactor
unit in the continuous mode would not allow
ANSTO to achieve their claim of 90% oxidation
of arsenite in solution. Channeling of the process
waters in the photoreactor unit was the reason for
poor oxidation of arsenite, and steps to correct the
problem during the field demonstration were
unsuccessful. Modifications to the baffle system
are necessary to prevent further channeling.
All work was completed, and the final report was
published.
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ACTIVITY III, PROJECT 9:
ARSENIC REMOVAL
Project Overview
The purpose of the Arsenic Removal Project was
to demonstrate the effectiveness of two innovative
technologies and the best demonstrated available
technology (BDAT) to remove arsenic from
mineral industry effluents to below 50 parts per
billion (ppb). Table AIII, P9-1 shows the
removal and economic analysis of these tests.
Two of the treated effluent streams were from the
ASARCO East Helena lead smelter; the scrubber
blowdown water contained > 3 grams per liter
arsenic and other associated metals, and the water
treatment thickener overflow water contained
approximately 6 parts per million arsenic. A third
stream from the TVX Mineral Hill Mine 1,300-
foot portal ground water contained approximately
500 ppb arsenic.
Alumina Adsorption
In this technology, arsenic is removed from
solution by adsorbing it onto the surface of
aluminum oxide over a specific pH range. After
absorption, reagents are added to the alumina to
desorb the arsenic into a concentrated brine. The
concentrated arsenic brine solution is then treated
using an iron adsorption technology to remove and
stabilize the arsenic. The activated alumina in the
process is recycled following the desorption
process by treatment with sodium hydroxide.
Ferrihydrite Adsorption
Ferrihydrite technology is the BDAT. For
ferrihydrite adsorption to occur, ferric iron (Fe+3)
must be present in the water. Dissolved arsenic is
removed by a lime neutralization process in the
presence of the ferric iron, which results in the
formation of arsenic-bearing hydrous ferric oxide
(ferrihydrite).
Results
Table AIII, P9-1. Removal and economic analysis for Activity
III, Project 9.
Technology
Mineral-
Like
Precipitate
Alumina
Adsorption
Ferrihydrite
Adsorption
Scrubber
Blowdown
(>3g/lAs)
< 10 ppb
_
_
Thickener
Overflow
(~6ppm)
< 10 ppb
200 ppb
< 50 ppb
Portal
Ground
Water (-500
ppb)
< 10 ppb
21 ppb
< 50 ppb
Cost/1000
gallons*
$0.30
$0.70
$0.55
*Cost analysis is based on treating 300 gpm of ground water containing 500 ppb
arsenic. The accuracy of the measurement is +/-30%.
Technology Description
Mineral-Like Precipitation
The concept of this process is to strip arsenic (as
arsenate) from solutions in a manner to produce
mineral-like precipitated salts. The concept is to
substitute arsenate into an apatite structure,
thereby, forming a solid solution compound that
would be thermodynamically stable in an outdoor
storage environment.
All three technologies (iron coprecipitation,
alumina adsorption, and mineral-like
precipitation) showed favorable results for arsenic
removal using ground water; however, using
industrial process wastewater, only two of the
technologies (mineral-like precipitation and
ferrihydrite adsorption) were capable of removing
arsenic to below discharge standards. The
complex chemistry of the industrial wastewater
had a profound effect on arsenic removal using
alumina adsorption.
All work was completed, and the final report was
published.
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ACTIVITY III, PROJECT 11:
CYANIDE HEAP BIOLOGICAL
DETOXIFICATION
DEMONSTRATION
Project Overview
Cyanide is used in the mining industry to dissolve
precious metals from ore but can contribute to
environmental problems. This has led to the
development of technologies to degrade cyanide
and cyanide complexes in mine wastewater and
spent ore heaps. Most of these processes use
chemicals to oxidize cyanide and are expensive to
operate. Therefore, biological detoxification has
been proposed as an alternative to chemical
treatment for decommissioning heap leach
operations.
Three biological technology providers were
contracted to participate in a long-term study in
which the effectiveness of their technology was
compared with hydrogen peroxide and process
rinse water.
Technology Description
This project demonstrated four biological
technologies. Project objectives were to:
- reduce the concentration of the effluent weak
acid dissociable (WAD) cyanide to meet National
and State regulatory standards within a
reasonable period;
- determine final affects of biological treatment on
related discharge parameters (pH, sulfates,
nitrates, metals, and gold recovery); and
- determine technology cost compared to
conventional detoxification methods. Column
testing began on December 3, 1998, and
operated 158 days until May 17, 1999.
Results
The standard hydrogen peroxide rinse column was
demonstrated to have the highest WAD cyanide
degradation rate. The regulatory limit of < 0.2
milligrams per liter was reached in 36 days. The
process rinse water column showed a cyanide
degradation curve of approximately one-third as
high as the hydrogen peroxide rinse column.
One technology provider reached the regulatory
limit in 151 days. The remaining three biological
processors were slightly quicker than the process
rinse water and were approaching the regulatory
limit at termination of the demonstration.
All work was completed, and the final report was
published.
ACTIVITY III, PROJECT 17:
LEAD ABATEMENT
DEMONSTRATION
Project Overview
The foremost cause of childhood lead poisoning in
the United States is the ingestion of lead-based
paint found in older housing. The overall objective
of this demonstration was to obtain cost and
performance data on an innovative set of
technologies capable of removing lead-based paint
from interior decorative wood in residential
housing with minimal damage to the underlying
substrate and no residual hazardous waste.
Technology Description
The technologies evaluated included the paint
removal system PR-40/LEADX™/PR-40AFX™ and
a carbon dioxide blasting technology.
Results
The paint removal system PR-40/LEADX™/ PR-
40AFX™ was demonstrated to effectively remove
lead-based paint and/or lead-based varnish from
interior decorative wood with minimal apparent
damage to the wood substrate within certain
operational limitations. The product proved
effective when previous paint/varnish layers were
between six to eight layers. Other wall coverings
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beneath the paint surface (i.e., wallpaper or wall
texturing) further impacted penetration of PR-
40/LEADX™/PR-40AFX™.
The carbon dioxide blasting technology was
effective in removing the lead-based paint only in
areas where PR-40/LEADX™/PR-40AFX™ had
achieved full penetration of all paint layers.
However, the blasting technology produced an
unsatisfactory erosion of soft wood leaving the
surfaces feathered and/or gouged.
ACTIVITY III, PROJECT 18:
GAS-FED SULFATE-REDUCING
BACTERIA BERKELEY PIT WATER
TREATMENT
Technology Description
Biomet Mining Corporation of Vancouver, British
Columbia, has patented a method utilizing
combustion products from natural gas as nutrients
for SRB, called the Biosulfide process. This cheap
source of nutrients has enabled Biomet to show
favorable economics in recovering copper and zinc
products from AMD at pilot-scale at several
locations in North America. Copper is recovered
directly as copper sulfide using hydrogen sulfide
gas produced by SRB. Following a pH adjustment
using the alkalinity produced by the SRB, hydrogen
sulfide gas is used to recover zinc as zinc sulfide.
Other products, including sodium hydrosulfide and
sulfuric acid, can be produced with downstream
processing if the economics at a specific location
are favorable.
Project Overview
Sulfate-reducing bacteria (SRB) are a well-known,
effective method for treating acid mine drainage
(AMD). With the proper conditions of solution
temperature and oxidation/reduction potential, and
with suitable nutrients available to the SRB, sulfate
is electrochemically reduced to sulfide, which
forms insoluble precipitates with many metals. In
addition, alkalinity is produced that serves to raise
the solution pH. Previous and current Mine Waste
Technology Program projects have successfully
demonstrated SRB in remote locations with the goal
of providing improved water quality at low cost.
Advances have been made in engineered systems
utilizing SRB, particularly in the area of providing
cheap nutrients to the bacteria, which significantly
enhance overall system economics. These
advances increase the possibility of utilizing SRB
as part of an AMD treatment system in which
selected metals are separated and recovered for
resale, offsetting overall treatment costs. This
project demonstrated and evaluated a process with
the potential to profitably recover copper, zinc, and
sodium hydrosulfide from Berkeley Pit water.
Results
Bench-scale miniplant testing began at the MSE
Technology Applications, Inc. (MSE) facility in
October 1998. Biomet performed laboratory tests
to determine initial pH and oxidation/reduction
potential conditions for copper and zinc
separation/recovery from September to November
1998. Biomass development was performed at
MSE with the pilot-scale system between
December 1998 and May 1999. Biomet moved the
pilot system to the Berkeley Pit in May 1999, and
MSE had virtually no involvement in the project
after that time due to budgetary constraints. Pilot-
scale operation continued at the Berkeley Pit until
September 1999, at which time the pilot system
was shut down with tentative plans to restart in
April 2000. Pilot-scale operation was plagued with
operational problems, particularly related to the
performance and reliability of the natural gas
burner and to the sulfate reduction performance of
the bacteria. At the direction of the U.S.
Environmental Protection Agency, MSE terminated
support of the project in December 1999.
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ACTIVITY IV, PROJECT 1:
BERKELEY PIT WATER
TREATMENT
Project Overview
Bench-scale research on treating water from the
Berkeley Pit was performed at Montana Tech of
the University of Montana, in Butte, Montana.
The Berkeley Pit is an abandoned open-pit copper
mine in Butte that has been filling with acidic water
since pump dewatering of adjacent underground
mines ceased in 1982. Flow into the Berkeley Pit
has varied from approximately 7.5 million gallons
per day initially to a current rate of approximately
2.5 million gallons per day.
The water in the Berkeley Pit was chosen for this
project due to its accessibility, abundance, and the
chemical similarities between it and other acidic
mine waters. Studies had been conducted since
1986 on the Berkeley Pit water, and substantial
analytical data had been developed, providing a
foundation for this project.
Technology Description
This project addressed treatability of the acid mine
water that is accumulating in the Berkeley Pit.
Appropriate treatment techniques were identified
and developed. The overall goal was to evaluate
technologies that produce clean water, allow for
safe waste disposal, and recover selected metals for
resale. Technologies were evaluated by
considering their effectiveness, technical
feasibility, and potential for technology transfer to
similar sites.
Experimental testing consisted of four phases:
Physical oxidation, neutralization, and metal
removal—this phase consisted of using alkaline
reagents such as lime, limestone, or soda ash to
neutralize the water and cause metals to precipitate
as hydroxides. During neutralization, the water is
aerated to oxidize Fe+2 to Fe+3, thereby, enhancing
sludge settling characteristics and promoting
adsorption reactions. Metals removal efficiency
and reaction kinetics were studied.
Metals separation and recovery—this phase was a
two-stage hydroxide precipitation process. Sulfide
and hydroxide precipitation were combined for
more complete removal of metals. In other tests,
metal sulfides were precipitated first to recover
metal value, and scrap iron was used to cement
copper before neutralization.
Use of milling waste—this phase consisted of
adding tailings slurry (primarily silicates, clay,
lime, and limestone) directly to the Berkeley Pit
water. This partially neutralized the water and
removed some of the heavy metals. This in situ
neutralization could potentially reduce reagent
consumption and sludge formation for subsequent
processing.
Diversion and treatment of various inflow water
sources—this phase consisted of investigating
numerous water sources to determine the feasibility
of diverting inflow water for treatment. Of the
water that flows into the Berkeley Pit, one-third is
surface water from the Horseshoe Bend area, and
two-thirds is underground water that has penetrated
through the mines and surrounding rocks.
Results
All work for this project was completed, and the
final report was published.
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ACTIVITY IV, PROJECT 2:
SLUDGE STABILIZATION
Project Overview
The Sludge Stabilization Project for mine waste
was a bench-scale research project conducted at
Montana Tech of the University of Montana.
The purpose of this research project was to study
the properties and stability of sludges generated by
remediation of acid mine waters. Results of the
study were used to determine the best methods for
sludge handling and disposal. One source of acid
mine water being studied was from the Crystal
Mine located approximately 7 miles north of Basin,
Montana. The other source was the water from the
Berkeley Pit in Butte, Montana. Besides being
acidic, these waters contain toxic concentrations of
iron, manganese, copper, zinc, arsenic, and
sulfate, which is typical of many hard rock mining
operations throughout the western United States.
Past research on remediating acid mine water has
focused primarily on water treatment techniques,
and little emphasis has been placed on the stability
of the sludge that is generated. To address this
issue, faculty at Montana Tech of the University of
Montana, with expertise in chemistry,
geochemistry, metallurgy, and environmental
engineering, formed a research team to study the
properties and stability of this sludge.
Technology Description
The three types of sludge studied were: base-
initiated sludge, inorganic sulfide-initiated sludge,
and sulfate-reducing bacteria-initiated sludge.
Appropriate solid-liquid separation techniques were
used to isolate the solid phases for chemical
characterization and stability tests.
Chemical characterization studies included
quantifying the various element-solid associations,
i.e., adsorbed, surface-precipitated, and
coprecipitated contaminants. These studies then
identified and quantified the divalent and trivalent
forms of iron and the trivalent, pentavalent, and
methylated forms of arsenic. Once analytical
techniques were verified for each of the sludges,
they were applied to as-generated sludge and
aged sludge.
Based on the chemical properties of these
sludges, various storage environments were
proposed and evaluated. The sludge stability
research included standard regulatory tests and
specifically designed tests, e.g., biostability tests,
based on the selected specific disposal options,
including storage in the natural environment.
The results of these tests were translated into
stability-enhancement studies, including the
effect of aging the sludge in a temporary storage
environment and treating the sludge with
chemical additives before final storage.
The results of this sludge characterization and
stability study identified characterization
techniques and stability procedures that have
application to sludges generated through other
water-treatment procedures.
Results
All work for this project was completed, and the
final report was published.
ACTIVITY IV, PROJECT 3:
PHOTOASSISTED ELECTRON
TRANSFER REACTIONS
RESEARCH
Project Overview
Research efforts under the Mine Waste
Technology Program for the remediation of mine
wastewaters have focused primarily on removing
toxic heavy metal cations from solution.
However, little attention has been given to toxic
anions that can be associated with the heavy
metal cations.
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Results
All work for this project was completed. The final
report was revised and published.
ACTIVITY IV, PROJECT 3A:
PHOTOASSISTED ELECTRON
TRANSFER REACTIONS FOR
METAL-COMPLEXED CYANIDE
Project Overview
Previous research efforts under the Mine Waste
Technology Program for the remediation of mine
wastewaters predominantly focused on removing
toxic heavy metal cations from solution. This was
accomplished with chemical processes that
generated heavy-metal sludges that were then
removed from the water stream by solid-liquid
separation processes. However, many of the
anions associated with the heavy metal cations in
the wastewater are also toxic but remain in solution
even after the sludge is generated and separated.
In this project, the remediation of metal-complexed
cyanide is being investigated using several
photolytic methods with the intent to identify and
enhance naturally occurring remediation processes.
Overwhelming evidence shows that natural
processes occur to heal environmental scars caused
by mining activities. These processes include
electron-transfer reactions that lower the
concentrations of the anionic mobile toxic
constituents in surface and ground waters through
interactions with electromagnetic radiation
(predominantly ultraviolet radiation but some
visible light) from the sun. However, such direct
natural photolytic processes suffer at night, on
cloudy days, and in winter months. During these
periods, artificial radiation sources are needed for
sustainment. Furthermore, because the photolytic
processes usually proceed slowly, catalysts are
used to absorb the radiation and transfer the energy
to the reactants to remediate the water within more
acceptable time frames. Such photocatalysts are
either solid semiconductors (heterogeneous
photocatalysts) or dissolved radicals in solution
(homogeneous photosensitizers).
Technology Description
Background—When electromagnetic radiation is
absorbed, electrons in the absorbing species pass
from a singlet ground state (S0) to an excited
electronic state (SJ. As long as the electron
remains in the excited state, the absorbing
species are more susceptible to their chemical
environment and are, therefore, more apt to
participate in electron-transfer reactions. The
absorbing species undergo photoreduction when
it donates the excited electron. Conversely,
photooxidation occurs when the absorbing
species accept an electron. In either case, the
photoreduction and photooxidation reactions can
lead to the destruction of the mobile toxic
constituent. For metal-complexed cyanide, only
photooxidation can be used and in a reaction
similar to cyanide photooxidation (see
Activity IV, Project 3) where carbon dioxide and
nitrogen gases are reaction products:
M(CN)/-X + xO2 = My+ + (V2)xN2(g) + xCO2(g) + xe~ .
Direct Photolysis—In this process, the mobile
toxic constituent being remediated must absorb
the electromagnetic radiation. Although this
phenomenon is rare, it does occur with some
metal-complexed cyanides but is dependent on
the solution conditions. Research was conducted
to identify these conditions.
Homogeneous Photolysis—In this process,
aqueous photosensitizers absorb the
electromagnetic radiation and then transfer the
photon energy to the mobile toxic constituents
being remediated. Because the process occurs in
bulk solution, its kinetics are dependent on the
solution conditions and the concentrations of the
photosensitizers and the mobile toxic
constituents. When the aqueous photosensitizer
is not consumed during the process, it is referred
to as homogeneous photocatalysis. In this
regard, research is being conducted to identify
the conditions needed for using either
homogeneous photosensitizers or homogeneous
photocatalysts for metal-complexed cyanide
remediation.
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Heterogeneous Photocatalysis—In this process,
solid semiconductors are used to absorb the
electromagnetic radiation and then transfer the
photon energy to the mobile toxic constituent being
remediated. However, electron transfer reactions
can only occur if the mobile toxic constituent is
adsorbed at the surface of the semiconductor.
Thus, reaction kinetics are dependent on the mobile
toxic constituent concentration as well as the rate of
adsorption of the constituent, the available surface
area of the semiconductor, and the rate of
desorption of the reaction products. Consequently,
reaction kinetics can be three orders of magnitude
slower than reactions with homogeneous
photolysis.
Nevertheless, reaction efficiencies are usually
higher with heterogeneous photocatalysis due to the
higher efficiency of photon capture and the
increased life of the electron in the excited state.
This is ultimately attributed to the properties of the
semiconductor. With semiconductors, electrons
are promoted from the valence band and into the
conductance band across a band gap. The photon
energy must be greater than or equal to the band
gap energy. Excited electrons in the conductance
band can then be donated to the mobile toxic
constituent to induce its reduction. Likewise, the
electron vacancy or hole in the valence band can
accept electrons from the mobile toxic constituent
and, thereby, induce its oxidation. The process is
similar to the process described earlier; however, it
is evident that solution conditions must also be
well-defined to control reactant adsorption and
product desorption. In this regard, studies are
being conducted to optimize these conditions for
metal-complexed cyanide oxidation reactions.
Currently, only anatase (TiO2) is being investigated
because it has the highest known efficiency of
semiconductors.
Results
This project was a continuation of the nitrate and
cyanide project (Activity IV, Project 3) but with
the inclusion of photolytic research on metal-
complexed cyanides. The final report was
published.
ACTIVITY IV, PROJECT 3B:
PHOTOASSISTED ELECTRON
TRANSFER REACTIONS FOR
BERKELEY PIT WATER
Project Overview
See Activity IV, Project 3A for Project
Overview.
Technology Description
Background — When electromagnetic radiation is
absorbed, electrons in the absorbing species pass
from a singlet ground state (S0) to an excited
electronic state (SJ. As long as the electron
remains in the excited state, the absorbing
species are more susceptible to their chemical
environment and are, therefore, more apt to
participate in electron-transfer reactions. The
absorbing species undergo photoreduction when
it donates the excited electron. Conversely,
photooxidation occurs when the absorbing
species accept an electron. In either case, the
photoreduction and photooxidation reactions can
lead to the precipitation of mobile toxic
constituents. For example, ferrous cations can
be precipitated as ferri-hydroxide after being
photooxidized to ferric cations:
h- Fe2+ = Fe3+ + e Fe3+ + 3OH = Fe(OH)3 (s) .
This reaction mechanism may account for the
natural precipitation events observed in Berkeley
Pit water. Once the iron is precipitated and
separated, photolysis and/or conventional
hydrometallurgical processes can then be used to
recover the valuable mobile toxic constituents.
On the other hand, a photoreduction reaction is
exemplified by sulfate conversion to elemental
sulfur:
SO42-(aq) + 8H
S(s) + 4H2O .
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Clearly, acid mine waters can be remediated
through photolysis. However, it is important to
note that several competing processes may occur
and must be prevented and/or minimized to
maximize the efficiency of photoassisted electron
transfer reactions.
Nevertheless, reaction efficiencies are usually
higher with heterogeneous photocatalysis due to the
higher efficiency of photon capture and the
increased life of the electron in the excited state.
This is ultimately attributed to the properties of the
semiconductor. With semiconductors, electrons
are promoted from the valence band and into the
conductance band across a band gap. The photon
energy must be greater than or equal to the band
gap energy. Excited electrons in the conductance
band can then be donated to the mobile toxic
constituent to induce its reduction. Likewise, the
electron vacancy or hole in the valence band can
accept electrons from the mobile toxic constituent
and, thereby, induce its oxidation. The process is
similar to the process described earlier; however, it
is evident that solution conditions must be well-
defined to control reactant adsorption and product
desorption. In this regard, studies are being
conducted to optimize these conditions for metal-
complexed cyanide oxidation reactions. For now,
both hematite (Fe2O3) and anatase (TiO2) are being
investigated. Hematite is important because it can
actually be formed by recycling the precipitated
ferrihydrite:
2Fe(OH)3 (s) = Fe2O3
3H2O.
Whereas, the anatase is important because it has
the highest known efficiency of semiconductors.
Results
The final report was published.
ACTIVITY IV, PROJECT 4:
METAL ION REMOVAL FROM
ACID MINE WASTEWATERS BY
NEUTRAL CHELATING
POLYMERS
Project Overview
A bench-scale research project was conducted at
Montana Tech of the University of Montana to
eliminate or minimize some current economic or
technical difficulties that exist in treatment
technologies for acid mine wastewater. The
novel technology was based on neutral chelating
polymers that can have their chelating property
turned on and off. The chelate switch was based
on known electrochemical or photochemical
properties of electrically conducting polymers.
Technology Description
Chelates are chemical substances that have more
than one binding site on the molecule. These
added binding sites attach a molecule to a metal
ion more strongly than a single binding site. The
result is that chelates can be very effective at
removing metal ions from wastewater. Chelates
can be ionic or neutral. Ionic chelates exchange
a cation (H+ or Na+) for the metal ion removed
from the solution. Neutral chelates are
electrically neutral and do not add material to the
solutions when the metal ions are removed.
The removal of metal ions from aqueous
solutions is presently accomplished by a variety
of chemical and electrochemical processes.
These techniques have distinct advantages in the
appropriate situations (pH range, concentration
range, matrix composition, etc.); however, they
may not be practical under less-than-optimum
operating conditions.
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The goal of this project was to develop an alternate
technology that required no additional chemicals,
could produce a marketable product (such as pure
metals), and could reduce costs and waste volume.
The research project was a collaborative effort
between academic and government resources,
including the Haskell Indian Nations Universities'
Haskell Environmental Research Studies Center.
Initially, the project focused on the design of
chelating polymer systems for laboratory study and
for theoretical study (molecular modeling). The
first polymer systems were based on current
literature information. Modeling results were
compared to experimental and literature results as a
means to test the validity of the theoretical data.
The validated modeling procedure was used to
design and test a variety of neutral chelating
systems for their capability to remove metal ions
and associated anions from acid mine wastewater.
The neutral chelating polymers determined to be
most effective for water cleanup by the preliminary
experimentation and the modeling studies were
studied more thoroughly. The polymeric systems
were evaluated for their removal efficiencies,
contaminant capacity, ruggedness, ease of use, and
cost effectiveness. Other important parameters
identified in the preliminary studies were also used
in the systems evaluations.
A more detailed process evaluation procedure was
developed from the results of the refined
experimentation. The selected polymeric system
was then completely studied using a variety of
synthetic and actual mine wastewater.
Results
All work for this project was completed, and the
final report was published.
ACTIVITY IV, PROJECT 5:
REMOVAL OF ARSENIC AS
STORABLE STABLE
PRECIPITATES
Project Overview
The objective of this project was to strip arsenic
from solutions in such a way as to produce
apatite mineral-like precipitated products that are
stable for long-term storage in tailing pond
environments. Substitution of arsenic into an
apatite structure will provide a solid solution
mineral compound that is environmentally stable
for outdoor pond storage.
Technology Description
Earlier research demonstrated that a precipitation
technique is effective in removing arsenic (to low
micrograms per liter concentrations) from
aqueous solutions [U.S. Environmental
Protection Agency (EPA)-supported project].
The precipitation is conducted in a way to form a
solid solution compound containing arsenate and
phosphate in an apatite mineral-like phase. This
solid is stable to EPA's toxicity characteristic
leachate procedure, and more importantly, the
solubility is one to two orders of magnitude less
than calcium arsenate in aqueous solutions over
the pH range of 9 to 12 (the range of pH values
maintained in tailing ponds).
In the early 1980s, it was demonstrated that lime
precipitation of calcium arsenate with subsequent
storage in a tailings pond environment is
unacceptable because at pH levels above
approximately 8.5, calcium arsenate will be
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converted to calcium carbonate (by carbon dioxide
in air) with the release of arsenic into the aqueous
phase. Removal of arsenic by precipitation as
calcium arsenate has been discontinued by industry
and has been replaced by ferric arsenate
precipitation (EPA's Best Demonstrated Available
Technology for arsenic-bearing solutions).
However, even though low concentrations of
arsenic in solutions can be achieved by ferric
precipitation, it has been demonstrated that the
removal from solution is actually an adsorption
phenomena. Therefore, long-term stability of such
residues in tailings pond environments may not be
appropriate, hence, the need for the present study.
Stability of Mineral-Like Residues—Montana Tech
of the University of Montana researcher's approach
to arsenic storage was to form a mineral-like phase
that showed equilibrium-phase stability under
tailings pond environmental conditions. If
equilibrium-phase stability was achieved (for a
given environment), then long-term stability would
be ensured (at least for as long as the
environmental conditions were maintained). This
project was supporting an intensive investigation of
the formation of arsenic precipitates in two
systems, i.e., the calcium-arsenic-phosphate
(apatite-like solid solutions of arsenate and
phosphate) system, and the ferric-arsenic-phosphate
(phosphoscorodite-like solid solutions of arsenate
and phosphate) system. Both of these systems
showed great promise for industrial application, if
long-term stability could be demonstrated.
ACTIVITY IV, PROJECT 7:
BERKELEY PIT INNOVATIVE
TECHNOLOGIES PROJECT
Project Overview
The purpose of the Berkeley Pit Innovative
Technologies Project was to provide a test bed
for high risk/innovative technologies for the
remediation of Berkeley Pit water. The project
focused on bench-scale testing of remediation
technologies to help assist in defining alternative
remediation strategies for the U.S.
Environmental Protection Agency's (EPA) future
cleanup objectives for Berkeley Pit waters.
Individuals, companies, or academic institutions
with existing remediation technologies were
invited to demonstrate their process for the
project and write a report summarizing their
process including the results of their bench-scale
test. A copy of the report from each test was
forwarded for evaluation by the EPA Region VIII
field office, and the EPA National Risk
Management Research Laboratory.
Results
Nine demonstrations were completed and reports
are available.
Results
The precipitation recipe was applied to two
industrially contaminated waters, and the long-term
stability of the resulting products were tested.
Successful demonstrations resulted in a new way to
treat arsenic-bearing wastewaters and mine
drainage solutions.
All work for this project was completed, and the
final report was published.
ACTIVITY IV, PROJECT 8: PIT
LAKE SYSTEM-CHARACTER-
IZATION AND REMEDIATION
FOR THE BERKELEY PIT
Project Overview
An interdisciplinary team of Montana Tech of the
University of Montana researchers undertook a
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preliminary study of several aspects of the Berkeley
Pit to gather specific information about that pit lake
system and to gather information that could be
generally applied to all pit lakes.
In this work, the chemical and biological
characteristics of the water and sediments in the
Berkeley Pit were studied to provide water quality
data that can be used to predict future water
quality, to evaluate the potential for natural
remediation by bacteria such as sulfate-reducers,
and to determine if partial in situ remediation
would be practical prior to the pump and treat
technologies prescribed in the U.S. Environmental
Protection Agency's Record of Decision.
To provide the water and sediment for the
characterizations, the Montana Bureau of Mines
and Geology sampled the water at two locations
and at depths from the surface to the bottom (0 to
1,200 feet) at set intervals. Sampling was also
done in both the spring and the fall to account for
climatic effects on surface water quality.
Results
The water chemistry of the Berkeley Pit lake varies
with the volume of water entering it from various
sources and the changes in the seasons. The
amount of metals precipitated from the surface
water layer depends on the area of the water
surface exposed to the air and the climatic changes
associated with the four seasons. The chemistry of
the deep water is relatively constant throughout the
year.
Organic carbon, a food source for bacteria is
present in the water. The concentration of organic
carbon is relatively that of the natural occurring
springs in the area of the Berkeley Pit.
No sulfate-reducing bacteria activity was detected
in the water or the sediments. However, a number
of fungi and yeasts were isolated, and these will be
further studied.
The report for this study is complete. This work
lead to the more specific research presented in
Activity IV, Projects 9, 10, 11, and 16.
ACTIVITY IV, PROJECT 9: PIT
LAKE SYSTEM-DEEP WATER
SEDIMENT/PORE WATER
CHARACTERIZATION AND
INTERACTIONS
Project Overview
Research under this project involved collecting
various water and solid samples from the
Berkeley Pit to characterize them and formulate a
conceptual environmental model of this well
known pit lake.
The work involved collecting deep water-upper
layer sediment samples (600 to 700 feet below
surface), collecting subsurface sediment/pore
water samples (717 feet below surface),
characterization and speciation of these sediment
solids and pore water, and modeling the system
to understand the controlling sediment forming
reactions.
Results
Significant differences did not appear in the
elemental content of the upper water column and
the deep water (near-sediment) solution. Iron
shows a slight (approximately 5%) increase in
concentration with depth. The ferrous-to-ferric
ratio shows an increase from the surface to
approximately 100 feet; the ratio then remains
constant from 100 to 717 feet. Sulfate showed a
generally increasing concentration as a function
of depth. The dissolved oxygen concentration
was relatively high near the surface, dropped
dramatically from 2 to 18 feet, and then rose to
levels exceeding the surface level. It then
became relatively constant with increasing depth
from approximately 100 feet to near the sediment
surface. The dissolved oxygen data appears to
suggest that surface water turnover may have
occurred down to the 100-foot level; however,
additional data is required to confirm this
conclusion.
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Pore water is the water present within the
sediments. This water was separated as a function
of depth into a series of samples. The pore water
was not clean and had appreciable elemental
content. Pore water had lower concentrations of
aluminum, zinc, manganese, magnesium, arsenic,
potassium, and phosphorus than deep water 3 feet
above the sediments. Ferrous iron concentrations
in the pore water were as much as four times
higher in the upper sediment layers than in the deep
water. The reaction of potassium jarosite and/or
schwertzmannite with organic carbon to form
ferrous species appears to be feasible for the
conditions existing in the sediments, and it is the
likely reaction controlling the ferrous concentration
in the pore water.
Sediment solids showed varying composition
trends. Elements that showed decreasing
concentration with depth include arsenic, calcium,
iron, magnesium, phosphorus, lead and sulfur.
The sediments were composed of detrital and
precipitated compounds. The major precipitated
compounds were jarosite and gypsum. The major
detrital compounds were quartz, biotite and
muscovite, which are predictable wall rock element
at the Berkeley Pit. It was observed that the
precipitated materials had a higher concentration at
the surface of the core, which suggests that the
precipitated solids formed in the water column and
settled to the sediment surface. With time, wall
rock joined the sediments and diluted them with
detrital materials.
All work was completed, and the final report was
published.
ACTIVITY IV, PROJECT 10: PIT
LAKE SYSTEM-BIOLOGICAL
SURVEY OF BERKELEY PIT
WATER
Project Overview
The purpose of this research was to begin to gain
an understanding of the microbial ecology of the
Berkeley Pit lake system and to provide
necessary data for bioremediation studies of this
pit lake and others. The study goals were to
determine species diversity and numbers for
organisms present in the pit lake system and to
begin to understand their potential role in
bioremediation.
Results
The research shows that bacterial abundances are
high throughout the surface water column; on
average, approximately 116,000 bacteria per
milliliter were found, which is only nine times
less than levels in a freshwater lake. Water
samples from a lower depth contain far fewer
bacteria (7,000 per milliliter). Sixteen
morphotypes of heterotrophic protists were
identified. Very few live cells were found in
fresh samples of water and sediments, suggesting
that active populations are rare and most may
exist as cysts, particularly in deeper anaerobic
layers. The sulfate-reducing bacteria that were
expected to be found in the water and sediments
did not exist.
All work was completed, and the final report was
published.
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KEY CONTACTS
U.S. Environmental Protection Agency:
Roger C. Wilmoth
U.S. Environmental Protection Agency
Office of Research and Development
National Risk Management Research
Laboratory
26 W. Martin Luther King Drive
Cincinnati, OH 45268
Telephone: (513) 569-7509
Fax: (513) 569-7471
wilmoth. roger @epa. gov
U.S. Department of Energy:
Madhav Ghate
U.S. Department of Energy
National Energy Technology Laboratory
P.O. Box 880
3610 Collins Ferry Road
Morgantown, WV 26507-0880
Telephone: (304) 285-4638
Fax: (304) 285-4135
mghate@netl. doe. gov
MSE Technology Applications, Inc.
Creighton Barry, Program Manager
MSE Technology Applications, Inc.
P.O. Box 4078
Butte, MT 59702
Telephone: (406) 494-7268
Fax: (406) 494-7230
cbarry @mse-ta. com
Montana Tech:
Karl E. Burgher, Montana Tech MWTP
Project Manager
Montana Tech of the University of Montana
1300 West Park Street
Butte, MT 59701-8997
Telephone: (406)496-4311
Fax: (406) 496-4116
kburgher@mtech.edu
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