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Annual Report 2001

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2001 Annual Report (PDF, 7.2 M, 71pp)

Table of Contents

Vision Statement for the Butte Mine Waste Technology Program

Program Manager's Executive Summary

Introduction

Program Overview

Organizational Structure

Activities

Descriptions, Accomplishments, and Future Direction

Activity I Overview Issues Identification

Activity II Overview Quality Assurance

Activity III Overview Pilot-Scale Demonstrations (Contains large graphics and will take at least 3 minutes to load)

Project 3 Sulfate-Reducing Bacteria Demonstration

Project 8 Underground Mine Source Control

Project 12 Sulfate-Reducing Bacteria Reactive Wall Demonstration

Project 14 Biological Cover Demonstration

Project 15 Tailings Source Control

Project 16 Integrated Passive Biological Treatment Process Demonstration

Project 19 Site In Situ Mercury Stabilization Technologies

Project 21 Integrated Process for Treatment of Berkeley Pit Water

Project 22 Phosphate Stabilization of Mine Waste Contaminated Soils

Project 23 Revegetation of Mining Waste Using Organic Amendments and Evaluate the Potential for Creating Attractive Nuisances for Wildlife

Project 24 Improvements in Engineered Bioremediation of Acid Mine Drainage

Project 25 Passive Arsenic Removal Demonstration Project

Project 26 Prevention of Acid Mine Drainage Generation from Open-Pit Mine Highwalls

Project 27 Remediating Soil and Groundwater with Organic Apatite

Project 29 Remediation Technology Evaluation at the Gilt Edge Mine

Project 30 Acidic/Heavy Metal-Tolerant Plant Cultivars Demonstration, Anaconda Smelter Superfund Site

Project 31 Remote Autonomous Mine Monitor

Project 33 Microencapsulation to Prevent Acid Mine Drainage

Project 34 Bioremediation of Pit Lakes (Guilt Edge Mine)

Project 35 Biological Prevention of Acid Mine Drainage (Gilt Edge Mine)

Activity IV Overview

Project 13 Sulfide Complexes Formed from Mill Tailings Project

Project 14 Artificial Neural Networks as an Analysis Tool for Geochemical Data

Project 16 Pit Lake System Characterization and Remediation for Berkeley Pit Phase III

Project 17 Mine Dump Reclamation Using Tickle Grass Project

Project 18 Investigation of Natural Wetlands Near Abandoned Mine Sites

Project 19 Removing Oxyanions of Arsenic and Selenium from Mine Wastewaters Using Galvanically Enhanced Cementation Technology

Project 20 Algal Bioremediation of Berkeley Pit Water, Phase II

Activity V Overview Technology Transfer

Activity VI Overview Training and Education

Financial Summary

Completed Activities

Key Contacts


Prepared by:

MSE 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


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 combinations of acidity, heavy metals, and sediment have severe detrimental environmental impacts on the delicate ecosystems in the West.

Philosophy / Vision

End-of-pipe treatment technologies, while essential for short-term control of environmental impact from mining operations, are a stopgap 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.

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 for effective environmental protection.

Resource Recovery
In the spirit of pollution prevention, much of the mining wastes, both AMD (e.g., over 25 billion 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. The Bureau of Land Management and Forest Service actively 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. Fortunately, the program has strong cooperation from industry. 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. We have strong interaction, cooperation, and assistance from the mining teams in the EPA Regional Offices, especially Regions 7, 8, 9, and 10. 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 related to kinetics, characterization, and bench-scale tests 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 annually by the Technical Integration Committee (TIC), who technically reviews all ongoing and proposed projects. The TIC is composed of technical experts from the U.S. Environmental Protection Agency and 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 2001 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 11 years, everyone involved with the MWTP can look with pride to the Program's success. Technology development and basic research has proceeded successfully through the efforts of MSE Technology Applications, Inc. (MSE) and its prime subcontractor Montana Tech.

MSE has developed thirty-four field-scale demonstrations, several of which are attracting attention from the stakeholders involved in the cleanup of mine wastes.

Montana Tech has developed twenty bench-scale projects, five of which are ongoing during 2001.

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.

Jeff LeFever
MSE 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 mining impacted 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.

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, $4.3 million in FY00, and $3.9 million in FY01.

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 of the MWTP in FY01.

Table 1. Number and types of sites and abandoned mine lands in Western Region.
State Estimated Number of Sites or Land Areas Classification and Estimated Number
Alaska 10,910 sites mine dumps - 1,000 acres
disturbed land - 27,680 acres
mine openings - 500
hazardous structures - 300
Arizona 95,000 sites polluted water - 2,002 acres
mine dumps - 40,000 acres
disturbed land - 96,652 acres
mine openings - 80,000
California 11,500 sites polluted water - 369,920 acres
mine dumps - 171 acres
mine openings - 1,685
Colorado 20,229 sites covering
26,584 acres
polluted water - 830,720 acres
mine dumps - 11,800 acres
disturbed land - 13,486 acres
mine openings - 20,229
hazardous structures - 1,125
Idaho 8,500 sites covering
18,465 acres
polluted water - 84,480 acres
mine dumps - 3,048 acres
disturbed land - 24,495 acres
mine openings - 2,979
hazardous structures - 1,926
Michigan 400-500 sites Accurate information not available.
Montana 19,751 sites covering
11,256 acres
polluted water - 715,520 acres
mine dumps - 14,038 acres
disturbed land - 20,862 acres
mine openings - 4,668
hazardous structures - 1,747
Nevada 400,000 sites Accurate information not available.
New Mexico 7,222 sites covering
13,585 acres
polluted water - 44,160 acres
mine dumps - 6,335 acres
disturbed land - 25,230 acres
mine openings - 13,666
hazardous structures - 658
Oregon 3,750 sites polluted water - 140,800 acres
mine dumps - 180 acres
disturbed land - 61,000 acres
mine openings - 3,750
hazardous structures - 695
South Dakota 4,775 acres Accurate information not available.
Texas 17,300 acres Accurate information not available.
Utah 14,364 sites covering
12,780 acres
polluted water - 53,120 acres
mine dumps - 2,369 acres
disturbed land - 18,873 acres
mine openings - 14,364
hazardous structures - 224
Wisconsin 200 acres Accurate information not available.
Wyoming 5,000 acres Accurate information not available.

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Program Overview
Fiscal Year 2001 Program

This Mine Waste Technology Program (MWTP) annual report covers the period from October 1, 2000, through September 30, 2001. This section of the report explains the MWTP organization and operation.

Mission

The mission of the 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, the 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, streamside 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.

Activity II: Generic Quality Assurance Project Plan

In 2001, EPA approved the Quality Management Plan for the MWTP. This plan provides specific instructions for data gathering, analyzing, and reporting for all MWTP 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.

MSE continued thirteen field-scale demonstrations during fiscal 2001. One field demonstration, Selenium Treatment, was completed. Ten projects were begun: 1) Passive Arsenic Removal Demonstration; 2) Prevention of Acid Mine Drainage Generation from Open-Pit Mine Highwalls; 3) Remediating Soil and Groundwater with Organic Apatite; 4) Remediation Technology Evaluation at the Gilt Edge Mine; 5) Acidic/Heavy Metal-Tolerant Plant Cultivars Demonstration, Anaconda Smelter Superfund Site; 6) Remote Autonomous Mine Monitor; 7) Microencapsulation to Prevent Acid Mine Drainage; 8) Bioremediation of Pit Lakes (Gilt Edge Mine); 9) Biological Prevention of Acid Mine Drainage (Gilt Edge Mine); and 10) Ceramic Microfiltration System Demonstration.

Activity IV: Bench-Scale Experiments

Montana Tech successfully completed three projects during fiscal 2001: 1) Pit Lake System-Characterization 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) an 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: Technology Transfer

MSE is responsible for preparing and distributing reports for the MWTP. These include routine weekly, monthly, quarterly, and annual reports; technical progress reports; and final reports for all MWTP activities. MSE 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: Educational Programs

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 metallurgical, 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 the MWTP. MSE Technology Applications, Inc. (MSE) 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.

Technical Integration Committee

The Technical Integration Committee (TIC) serves several purposes in the MWTP organization: 1) TIC reviews new proposals and ranks them at a meeting held in Butte, Montana; 2) it reviews progress in meeting the goals of the MWTP and alerts the Interagency Agreement Management Committee to pertinent technical concerns; 3) it provides information on the needs and requirements of the entire mining waste technology user community; and 4) it assists with evaluating technology demonstrations as well as technology transfer. This committee is comprised of representatives from both the public and private sectors.

View - Mine Waste Technology Program Organizational Structure (GIF, 34 Kb)

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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 2001, and future project direction.

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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:

The status of the appendices for approved projects includes:

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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, 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.

The U.S. Environmental Protection Agency approved the MWTP Quality Management Plan in 200l.

View - Mine Waste Technology Quality Management Plan

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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 13: Sulfide COMPLEXES Formed from Mill Tailings Project

Project Overview

A general belief is 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 case of 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 Berkeley Pit. The main goal of this project was to determine the leachability of the tailings produced by Montana Resources during their operation. This research was very timely since Montana Resources, ARCO, and the EPA are presently considering depositing the tailings produced by Montana Resources into the Berkeley Pit Lake.

Status

The following summarizes the data generated during this project.

The initial conditions of the components of the experiment are as follows:

Using a mass balance approach, the total metals leached out of the tailings material was determined. Tailings slurry with lime added deposited in Berkeley Pit water showed a 10% increase in dissolved copper, an 18% increase in dissolved iron, a 65% increase in sulfate, and a 16% decrease in dissolved arsenic. Tailings slurry without lime added deposited in Berkeley Pit water showed a 2% decrease in dissolved copper, a 10% increase in dissolved iron, a 30% increase in sulfate and a 3% decrease in dissolved arsenic. Unlimed tailings were also mixed with distilled water; but because of the low concentrations present, only qualitative statements can be made. Significant increases in dissolved copper, iron, and sulfate can be determined, but the actual percentage of the increase would not be relevant. The pH of the limed tailings/Berkeley Pit water mixture ranged from 4.0 standard units near the top of the column to 3.7 standard units at the bottom. The pH of the unlimed tailings/Berkeley Pit water mixture ranged from 4.5 standard units near the top of the column to 3.7 standard units at the bottom. The pH of the unlimed tailings/distilled water mixture was fairly constant at about 7.0 standard units throughout the column.

The Final report will be completed in FY02.

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Activity IV, Project 14 Artificial Neural Networks as an Analysis Tool for Geochemical Data

Project Overview

The Montana Bureau of Mines and Geology provided inductively coupled plasma (ICP) water quality analysis data from the Berkeley Pit that were used in a neural network approach to modeling Berkeley Pit water chemistry. The available Berkeley Pit data comprise a relatively small data set for neural network analysis and results, though encouraging, are not reliable for substantive predictive modeling.

Artificial neural networks comprise a relatively new approach to modeling complex nonlinear systems. Due to the inherent structure of neural networks, they have the desirable characteristics of being tolerant of noise in data and, more importantly, of not requiring a priority model for parameter prediction. Instead, neural networks learn relationships from data examples.

Neural networks are generally grouped into two main categories: supervised and unsupervised. Supervised neural networks use known data examples consisting of input/desired output pairs and adjust themselves to learn the relationship between input/output data. Unsupervised neural networks use only input data with no known output pairs. Unsupervised neural networks work by detecting clusters and trends in the data with minimal user input. As such, unsupervised neural networks can provide a powerful, unbiased approach to data analysis. Both neural network approaches excel in analyzing large, complex, multidimensional data sets.

Two neural network approaches were used to analyze the available Berkeley Pit data. First, the data matrix was used as input to an unsupervised neural network to determine if any previously unidentified data clusters or trends could be determined. For this sparse data set, this classification or data-mining approach was unsuccessful. Secondly, supervised neural networks were constructed and trained to investigate relationships between the various chemical species, depth, pH, and specific conductivity. Various testing combinations were analyzed and results are encouraging to pursue this approach with a more complete data set.

Status

Results were not verified with a comprehensive testing data set; but because they were validated with small data subsets, indications are that neural networks can analyze sparse, geochemical data with good reliability. In each case, the successful results were repeatable, which is a good indicator of reliability. More data is needed, and the intention of this project is to recommend a good sampling program over the next few years. If complete data were to be collected, a neural network could determine data relationships in a fraction of the time.

The final report will be completed in FY02.

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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.

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 groundwater and a range of ground-water qualities entering the pit: a) contaminated groundwater from the underground workings in the bedrock aquifer west of the pit; b) uncontaminated groundwater from the bedrock aquifer east and southeast of the pit; and c) contaminated alluvial groundwater 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. Groundwater and surface water north of the divide flow into the pit while groundwater 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 groundwater 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

Humic Remediation Potential
The results from the experiments demonstrated that organic amendments can have a positive effect on the remediation of the water in the Berkeley Pit. Of the four organic amendments tested (sawdust, aspen leaves, lawn clippings, and treated sewage sludge), the treated sewage sludge was the most effective at removing the high concentration metal ions from the water and raising the pH of the acidic water. The experimental variables of light versus dark and readily available room air versus exclusion of room air had minimal differences in the sequestering of most metals. Iron was the major exception to this observation.

Algal Remediation of Berkeley Pit Water
In general, Chromulina freiburgensis did not remove metals over a long-term experiment through absorption or adsorption from Berkeley Pit water. Removal was not observed for aluminum, cadmium, chromium, copper, magnesium, manganese, sulfur, and zinc. Significant removal was detected for calcium (12.8%), iron (12.7%), nickel (8.4%), and silicon (56.2%).

Metal removal was not observed, possibly because of the long experimentation time of 90 days. In this time, cultures of Chromulina freiburgensis could have become nutrient starved and formed cysts. It is possible that the metals were adsorbed initially, and rereleased when the cells became stressed. Further discussion is provided in the final report.

Berkeley Pit Aquifer Modeling
Since water-level data for the alluvial wells and the Berkeley Pit continue to be collected, it is possible to continue the calibration process for several years. In 1995, water levels in the alluvial aquifer south of the pit had increased by 1 to 3 feet compared to 1991 water levels; by 1998, water-level rise ranged from 5 to 9 feet compared to 1991 data. In addition to the continued water-level rise in the pit, this period coincides with greater-than-normal precipitation in the area. Thus, calibration in the strictest sense becomes ambiguous: the relative contribution of the pit water-level rise and the increased recharge cannot be determined. Through modeling, however, the increased recharge can be eliminated; modeling can demonstrate if the pit is contributing to the water-level change in the alluvium.

Remediation by Photocatalysis
In summary, iron removal (Stage I) was successful and fairly selective with ultraviolet photo-oxidation in the presence of hydrogen peroxide; was best under high oxidation conditions with 254-nm radiation within the 2-hour time examined; and was essential in this photochemical treatment process (as noted in most other industrial selective-metal recovery processes).

Removal of arsenic (Stage I) was successful and principally followed the ANSTO UV-Process. Manganese removal could be accomplished with photo-oxidation but requires further research to prove. In this regard, it had to be accomplished by permanganate addition resulting in Stage Two. Because permanganate can increase manganese concentrations, other oxidants should be tested. Sulfide precipitation of copper (Stage III) and cadmium (Stage IV) were successful. Zinc removal (Stage IV) appeared to follow wurtzite solubility; thus, ZnS precipitation did not meet the drinking water standard. However, sphalerite seeding of the stage could prove worthy and needs further study. Aluminum precipitation (Stage V) as a hydroxide also nearly met the drinking water standard and could feasibly benefit from seeding as well.

Based on the results and discussions of this study, it is clear that the manganese, zinc, and aluminum removal stages could be improved. As discussed previously, this may simply involve seeding the zinc and aluminum precipitation stages with more stable solids or studying further the manganese photo-oxidation process. Of course, other possibilities could be explored and may involve kinetics and temperature effects. Likewise, all stages in the selective metal recovery process could be improved kinetically, thermally, and/or chemically by using better compounds.

The final report will be completed in FY02.

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Activity IV, Project 17: Mine Dump Reclamation Using Tickle Grass Project

Project Overview

Experiments were conducted to test the reclamation potential of tickle grass in the greenhouse at Montana Tech and on three reciprocal transplant sites with the hypothesis that the Badger Mine (BM) tickle grass population is an ecotype within the species suitable for the reclamation of mine dump materials. Agrostis hiemalis, tickle grass, grows on the dump consisting of acid generating rock and tailings formed about 25 years ago. Tests indicate that this site has a pH of 3.1, and the soil material has high concentrations of heavy metals such as arsenic, copper, iron, lead, nickel, and zinc. The area is located near the Badger Mine site, northeast of Walkerville in Silver Bow County, Montana.

The performance of the BM tickle grass population was compared to populations of tickle grass from the Beaver Pond (BP) site and Yellowstone National Park (YN) growing at the Bridger Plant Material Center in Bridger, Montana. Data analysis was conducted for height, basal area, biomass, vigor, plant appearance, and state of the flower head to determine whether BM tickle grass population is an ecotype adapted to harsh conditions.

Status

The results of height and basal area from the greenhouse study partially validated the hypothesis of the BM tickle grass population being an ecotype within the species, where as the hypothesis of the BM tickle grass population being more suitable to the mine dump material was not completely satisfied. The results of the transplant garden study partially supported the hypothesis of the BM tickle grass population being suitable for the reclamation of mine dump material as compared to the BP and the YN population. Soil characterization of the Badger Mine dump material verified the assumption of the BM tickle grass population surviving harsh conditions of low pH, low nutrient levels, and high concentrations of heavy metals such as arsenic, copper, iron, lead, nickel, and zinc. An on-site reclamation option was favored for the Badger Mine site.

The final report will be completed in FY02.

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Activity IV, Project 18: Investigation of Natural Wetlands near Abandoned Mine Sites

Project Overview

The main objective of this project was to determine how and to what extent metals are being attenuated by natural wetlands at two remote locations in Montana. Sites selected for fieldwork included the Copper Gulch wetland (near Jefferson City, Montana), and the Fisher Creek wetland (near Cooke City, Montana). At both sites, representative samples of soil, groundwater, and surface water were collected for metal analysis. The hydrogeology of each wetland was characterized, with the help of shallow piezometers to monitor water level and to collect groundwater samples. Each site was visited several times throughout the year to determine seasonal changes in hydrology or metal removal efficiency.

Status

At Copper Gulch, discharging groundwater initially had low pH (3.5 to 4) and elevated concentrations of metals, including aluminum, iron, copper, manganese, and zinc. By the time water reached the outlet of the sedge wetland, pH rose to > 5, and concentrations of aluminum, iron, and copper were decreased. Most of the copper appeared to be scavenged by the subsurface wetland soils; whereas, aluminum and iron were precipitated within the surface drainage of the wetland. At Fisher Creek, influent springs were weakly acidic, very dilute, but contained elevated copper concentrations. Although a quantitative water and copper mass balance was not possible, it appeared that most of the influent copper passed through or around the wetland, with only localized attenuation. Nonetheless, copper concentrations in humic wetland soils at this site were extremely high (> 1 wt %), indicating that metal removal, although inefficient, can result in impressive accumulations over very long periods of time.

If natural wetlands are to be used for treating metals or acidity near abandoned mine sites, steps should be taken to create the largest water retention time possible, which may entail enlarging a preexisting wetland or eliminating channeled flow. The potential for metal-rich wetlands to become a source, rather than a sink, for contaminants should also be considered.

The final report will be completed in FY02.

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Activity IV, Project 19: Removing Oxyanions of Arsenic and Selenium from Mine Wastewaters using Galvanically Enhanced Cementation Technology

Project Overview

Many solution species can be effectively removed from mine water by electrochemical reduction of the aqueous species, to a solid elemental species on the surface of a metal (called cementation), e.g., aqueous solution species of copper, arsenic, selenium can be reduced to the solid elemental state on an iron surface. Presently, the industrial use of cementation has been limited to copper recovery. It was proposed that the rate of reduction of arsenic (arsenate, arsenite) and selenium (selenate, selenite) could be increased dramatically by using galvanically coupled substrates (instead of iron).

Galvanically coupled substrates provide greatly enhanced active metal dissolution rates. The enhanced metal dissolution rates (called anodic dissolution) are accompanied by the production of electrons in the substrate (iron). The available electrons in the substrate metal (iron) must be discharged at cathodic sites on the more noble metal surface. The consumption of electrons is characterized as reduction reactions, i.e., reduction of aqueous species in the solution phase to the elemental state on the nobler cathodic surface. Therefore, if the metal dissolution rate is enhanced (increased) then the reduction rate of oxyanions (arsenic and selenium) will also be increased.

Two major experimental studies were conducted during the present investigation, i.e., electrochemical characterization of iron and galvanic couple surfaces and application of iron and galvanic couples for selenium/arsenic removal from synthetic and real solutions. The conclusions drawn from each of the major studies are briefly presented below.

Status

Electrochemical Characteristics of Iron and Galvanic Couple Surfaces

Selenate. The conclusions drawn from the electrochemical studies included:

Arsenate. The conclusions drawn from the electrochemical studies included:

Application of Iron and Galvanic Couples for Selenium/Arsenic Removal

Kettle Reactor Test Work. The conclusions drawn from the kettle treatment test work using synthetic water and industrial water included:

The final report will be completed in FY02.

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Activity IV, Project 20: Algal Bioremediation of Berkeley Pit Water, Phase II

Project Overview

The Berkeley Pit Lake System is one of the largest contaminated sites in North America and is located near the headwaters of the largest superfund site in the United States. The Pit Lake is more than 542 meters deep with a lateral extent of approximately 1.8 by 1.4 kilometers across the rim. The only larger pit mine in the United States is the Bingham Pit in Salt Lake City, Utah. The Berkeley Pit has a water depth of approximately 275 meters and is rising at a rate of about 8 meters per year. This represents roughly 1,140 billion liters of metal laden, contaminated water, with a pH of 2.7, that has been designated a Superfund project for cleanup. The goal of the Mine Waste Technology Program, Activity IV Project, was to continue to gain an understanding of the microbial ecology of the Berkeley Pit Lake System, which will ultimately provide necessary data for bioremediation studies that may apply to other contaminated pit lakes worldwide.

Status

Preliminary lab experiments showed that even getting algae to grow to very eutrophic levels did not significantly remove metals from the water. The only metal that was significantly removed was aluminum, and the final concentration of aluminum under optimal removal in the experiments was 150 mg/L.

Furthermore, under optimal experimental metal removal, the pit water still contained high levels of metals and would need to be treated with lime precipitation as stated in the record of decision. Since the solubility product of Al(OH)3 is 3.8 X 10-9 compared to the solubility product of Cu(OH)2 of 3.5 X 10-7, the aluminum would precipitate before the copper. Therefore, aluminum removal by the algae would not significantly reduce the treatment cost for Berkeley Pit water or significantly reduce the amount of sludge generated.

The final report will be completed in FY02.

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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

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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 2001 Highlights

Future Activities

The following training and educational activities are scheduled for 2002:

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Financial Summary

Total expenditures during the period October 1, 2000, through September 30, 2001, were $3,687,532, including both labor and nonlabor expense categories. Individual activity accounts are depicted on the performance graph in Figure 27.

Contact Diana Bless at 513-569-7674 for explanation.
Figure 27. Mine Waste Technology Program fiscal 2001 performance graph, costs per activity.

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Completed Activities

For information on the following completed Mine Waste Technology Program activities, refer to the web site: http://www.epa.gov/ORD/NRMRL/std/mwt/

Activity III
Project Number Project Name
Project 1 Remote Mine Site Demonstration
Project 2 Clay-Based Grouting Demonstration
Project 4 Nitrate Removal Demonstration
Project 5 Biocyanide Demonstration
Project 6 Pollutant Magnet
Project 7 Arsenic Oxidation
Project 9 Arsenic Removal
Project 10 Surface Waste Piles --- Source Control
Project 11 Cyanide Heap Biological Detoxification Demonstration
Project 12A Calliope Mine Internet Monitoring System
Project 13 Hydrostatic Bulkhead with Sulfate-Reducing Bacteria
Project 17 Lead Abatement Demonstration
Project 18 Gas-Fed Sulfate-Reducing Bacteria Berkeley Pit Water Treatment
Project 20 Selenium Removal/Treatment Alternatives
Activity IV
Project Number Project Name
Project 1 Berkeley Pit Water Treatment
Project 2 Sludge Stabilization
Project 3 Photoassisted Electron Transfer Reactions Research
Project 3A Photoassisted Electron Transfer Reactions for Metal-Complexed Cyanide
Project 3B Photoassisted Electron Transfer Reactions for Berkeley Pit Water
Project 4 Metal Ion Removal from Acid Mine Wastewaters by Neutral Chelating Polymers
Project 5 Removal of Arsenic as Storable Stable Precipitates
Project 7 Berkeley Pit Innovative Technologies Project
Project 8 Pit Lake System Characterization and Remediation for the Berkeley Pit
Project 9 Pit Lake System Deep Water Sediment/Pore Water Characterization and Interactions
Project 10 Pit Lake System Biological Survey of Berkeley Pit Water
Project 11 Pit Lake System Characterization and Remediation for Berkeley Pit Phase II
Project 12 An Investigation to Develop a Technology for Removing Thallium from Mine Wastewaters

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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

MSE Technology Applications, Inc.:
Jeff LeFever, Program Manager
MSE Technology Applications, Inc.
P.O. Box 4078
Butte, MT 59702
Telephone: (406) 494-7358
Fax: (406) 494-7230
jlefever@mse-ta.com

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

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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