United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(5305W)
EPA530-R-01-002
March 2001
www.epa.gov/osw
&EPA Abandoned Mine Site
Characterization and
Cleanup Handbook
Printed on paper that contains 50 percent postconsumer fiber
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Disclaimer
This document provides a reference resource for
Environmental Protection Agency (EPA) and other staff
addressing characterization and cleanup of abandoned mine
sites. The document does not substitute for EPA statutes,
regulations and guidance, nor is it a regulation itself. It
cannot impose legally binding requirements on EPA, the
states, or the regulated community, and may not apply to a
particular situation based on the circumstances. EPA may
change this reference document in the future, as
appropriate. The mention of trade names or company
products does not constitute or imply endorsement or
recommendation for use by either the U.S. Government or
EPA.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 10
1200 Sixth Avenue
Seattle, WA 98101
Reply To
Attn Of:
ECL-117
Handbook Users:
The Abandoned Mine Site Characterization and Cleanup Handbook
(Handbook) is the result of the collective efforts and contributions of a
number of individuals. During the earliest days of Handbook development,
Mike Bishop of EPA Region 8 lead the effort to develop a Superfund Mine
Waste Reference Document for EPA project managers working on mine
site cleanup. That effort evolved into the Handbook in recognition of the
many regulatory and non-regulatory mechanisms that are used today to
manage the characterization and cleanup of mines sites.
Users are encouraged to consider the information presented in the
Handbook against the backdrop of site specific environmental and
regulatory factors. The Handbook has been developed as a source of
information and ideas for project managers involved in the characterization
and cleanup of inactive mine sites. It is not guidance or policy.
The list that follows acknowledges the efforts of writers, reviewers, editors,
and other contributors that made development of the Handbook possible. It
is always a bit risky to develop a list of contributors because it is inevitable
that someone gets left out; to those we have neglected to acknowledge
here we apologize.
Nick Ceto
Regional Mining Coordinator
EPA Region 10
Seattle, Washington
Shahid Mahmud
OSWER
EPAHQ
Washington, D.C.
Printed on Recycled Paper
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Abandoned Mine Site Characterization and Cleanup Handbook Conltributors
Fred Macmillan
Brad Bradley
Shawn Ghose
Mark Dooian
Mike Bishop
Matt Cohn
Carol Russ
Jim Dunn
Elisabeth Evans
Holly Fliniau
Eva Hoffman
Victor Kettelapper
Sonya Pennock
Mike Holmes
Andy Lensink
Ken Wangerud
Sara Weinstock
Chris Weis
Patti Collins
Ken Green berg
Mike Hingerty
Nick Ceto
Bruce Duncan
Earl Liverman
Roseanne Lorenzana
Patty McGrath
Don Metheny
Michelle Pirzadeh
Judy Schwarz
Sean Sheldrake
Bill Riley
Dave Tomten
Shahid Mahmud
Joe Tieger
Steve Hoffman
David Cooper
Steve Ells
Mike Goldstein
Sheila Igoe
Leslie Leahy
Andrea McLaughlin
Tom Sheckells
Gary Lynch
Dave Norman
EPA Region III
EPA Region V
EPA Region VI
EPA Region VII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region VIII
EPA Region IX
EPA Region IX
EPA Region IX
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA Region X
EPA OERR
EPA OSRE
EPA OSW
EPA OERR
EPAOERR
EPA OERR
EPAOGC
EPA OERR
EPA OERR
EPA OERR
State of Oregon
State of Washington
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Table of Contents
Chapter 1 Introduction
1 .1 Introduction ............. ........................................ 1_1
1 .2 Contents of Handbook . ............ .......................... ...... ^-2
Chapter 2 Overview of Mining and Mineral Processing Operations
2. 1 Introduction ............. ......... ..... . ................... ..... 2-1
2. 2 Mining . . . . ............ , ............................ ..... ....... 2-1
2. 2. 1 Types of Mining Processes ................................ 2-2
2. 2. 2 Mining Wastes and Hazardous Materials .......... ............ 2-3
2. 3 Beneficiation: Milling . . . .......................................... 2-5
2. 3. 1 Types of Beneficiation (Milling) Processes . .................... 2-5
2. 3. 2 Beneficiation (Milling) Wastes and Hazardous Materials .......... 2-7
2. 4 Beneficiation: Leaching .............................. . ............ 2-9
2. 4. 1 Types of Processes Associated with Leaching .................. 2-9
2. 4. 2 Leaching Wastes and Hazardous Materials .... ............... 2-12
2. 5 Mineral Processing . . : ................... . .................... 2-12
2. 5. 1 Types of Mineral Processing Operations ..................... 2-13
2. 5. 2 Types of Mineral Processing Wastes and Hazardous Materials .... 2-14
2. 6 Additional Sources of Information ............................ . ..... 2-16
Chapter 3 Environmental Impacts from Mining
3.1 Introduction ....... .............................................. 3_1
3.2 Acid Drainage ........... . ....... : ............. .................. 3-1
3.3 Metal Contamination of Ground and Surface Water, and Associated Sediments 3-3
3.4 Sedimentation of Surface Waters .................... . , ............ . . 3.5
3.5 Cyanide .............. ........ ........ . ....................... . 3_6
3.6 Air Emission and Downwind Deposition ...................... . ........ 3.3
3.7 Physical Impacts from Mine and Waste Management Units ............. ... 3-9
3.8 Sources of Additional Information ...... . ...... ...................... 3-11
Chapter 4 Setting Goals and Measuring Success
4.1 Introduction .................. , . . . , .............................. 4-1
4.2 National and Regional Goals ........................................ 4-1
4.3 State and Local Goals ............................................ 4_2
4.3.1 Human Health Impacts ............. . ............... . ....... 4.2
4.3.2 Environmental Impacts ...... ........ ....... . ............... 4.3
4.3.3 Getting it Done ................................ ........... 4.3
4.3.4 Values and Choices ........ . ................ .............. 4.4
4.4 Measuring Success .............................................. 4.4
4.5 Sources of Additional Information . . . . .................... -. . . .......... 4.5
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ii Table of Contents
Chapters Community Involvement at Mining Waste Sites
5.1 Introduction • • 5~\
5.2 Considerations for Community Involvement at Mine Waste Sites o-i
5.2.1 Community Values and Culture 5-1
5.3 Risk Perception
5.4 Liability
5.5 Economic Impacts °"
5.6 Fiscal Impacts on Local Government - • 5-6
5.7 Federal Land Managers 5-7
5.8 Uncertainty |~£
5.9 Additional Sources of Information • • - 5"B
Chapter 6 Scoping Studies of Mining and Mineral Processing Impact Areas
6.1 Introduction . . jj'J
6.2 Scoping ~. x~!
6.3 Difficulties in Scoprig Abandoned Mine Sites o-^
6.4 Scoping Issues Associated with Mining and Mineral Processing Sites ,6-4
6.4.1 Operable Units 6-4
6.4.2 Interim Actions ; ... r ..... 6-6
6.4.3 Unusual Requirements - 6'°
6.5 Sources of Additional Information ' 6"7
Chapter 7 Sampling & Analysis of Impacted Areas
7.1 Introduction ~L~^
7.2 Sampling and Analysis • - "TO
7.3 Issues for Sampling at Mining and Mineral Processing Sites 7-2
7.3.1 Defining Analytical Data Needs 7-2
7.3.2 Understanding Pre-Mining Conditions 7-2
7.3.3 The Importance of Site Characterization 7-4
7.3.4 Calculating Preliminary Remediation Goals 7-4
7.3.5 Selecting a Qualified Analytical Laboratory 7-5
7.3.6. Determining the Leachability of Contaminants 7-5
7.3.7 Selecting Analytical Methods r . 7-6
Chapters Scoping and Conducting Ecological and Human Health Risk Assessments At
Superfund Mine Waste Sites
8.1 Introduction - " ' f~i
8.2 Supporting Guidance Documents 8-1
8.3 Overview of Mine Waste Site Risk Assessment Features 8-2
8.3.1 Site Characteristics • 8'2
8.3.2 Comprehensive Risk Assessment Considerations 8-3
8.4 Ecological Risk Assessment 8-4
8.4.1 Identification of Potential Chemical and Physical Stressors . 8-b
8.4.2 Problem Formulation - 8-5
8.4.3 Characterization of Ecological Effects < • - • 8-6
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Table of Contents Hi
Chapters Scoping and Conduct ing Ecological and Human Health Risk Assessments At
Superfund Mine Waste Sites (continued)
8.5 Human Health Risk Assessment r .....>. s.; 8-7
8.5.1 Contaminants of Potential Concern 8-7
8.5.2 Exposure Assessment 8-9
8.5.3 Toxicity Assessment ... ....'.'.'.'. 8-10
8.5.4 Health Studies '.'.'.'.'.'.'.'"' 8-10
8.6 Probabilistic Analysis \\ 8-11
8.7 Risk Characterization 3-11
8.8 Risk Communication 3-12
8.9 Removal Actions 312
8.9.1 Health Effects ... ....'.'.'.' 8-12
8.9.2 Risk Management Considerations 8-13
8.10 Sources of Additional Information 8-13
Chapter 9 Site Management Strategies
9.1 Introduction g_1
9.2 Managing for Risk Reductbn 9-1
9.3 Categories of Activities that Address Risk Elements '.'.'.'.'.'.'.'. '.'.'. .9-2
9.4 Time-Based Responses .... 9.3
9.4.1 Time-Critical Actions . " ' 9.4
9.4.2 Interim Responses 9.5
9.4.3 Long-Term Responses 9.7
9.5 Strategic Planning Considerations . . 93
9.5.1 ARARs .'.".".".".".".".'."."."..".".".'.""!'." 9-8
9.5.2 State and Other Agencies 9-9
9.5.3 Brownfield Initiative 9_10
9.5.4 Enforcement Considerations , ••-.-- ^^
9.6. Additional Sources of Information '.'.'.'.'.'.'.'.'. 9-11
Chapter 10 Remediation and Cleanup Options
10.1 Introduction ^0-1
10.2 Background •.'.'/"' 10-1
10.3 Conventional Technologies . ." 10-3
10.3.1 Treatment Technologies 10-3
10.3.2 Collection, Diversbn, and Containment Technologies . 10-5
10.3.3 Reuse, Recycle, Reclaim '.'.'.'.'.'. 10-9
10.4 Innovative/Emerging Technologies ' -jQ-9
10.5 Institutional Controls 1010
10.6 Sources of Information and Means of Accessing Information
Regarding Available Technologies 10-12
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iv Table of Co ntents
Chapter 11 The Regulatory "Toolbox"
11-1
11-1
11-2
11-2
11-2
11-2
11-2
11.1 Introduction •
11.2 Background •
11.3 CERCLA Jurisdiction/Applicability
11.3.1 Jurisdictional Conditions
11.3.2 Media
11.3.3 Constituents
11.4 Implementation Mechanisms ''"'
11.4.1 Permits .'
11.4.2 Review/Approval ""113
11.4.3 Response Authorities
11.4.4 Standard Setting • •
11.4.5 AppBcable or Relevant and Appropriate Requirements
11.5 Compliance/Enforcement
11.5.1 Administrative and Injunctive Authorities
11.5.2 CostRecovery
11.5.3 Civil Penalties
11.5.4 Criminal Penalties
11.5.5 Information Collection - • •
11.6 Other Superfund "Tools" ''"'
11.6.1 Funding •
11.6.2 Natural Resource Damage Provisions ..
11.6.3 Good Samaritan Provisions •
11.6.4 Native American Tribes
11.7 Limitations -
11.7.1 Federally Permitted Release
11.7.2 Pollutants and Contaminants
118 Ability to Integrate with Other Statutes
11.9 Federal Facilities and Other Federal Issues ' '-»
11.10 Other Regulatory Tools •
11.10.1 Clean Water Act ' "
11.10.2 Resource Conservation and Recovery Act ' '-<"
11.10.3 Toxic Substances Control Act \\-\\
11.10.4 Miscellaneous Requirements 1112
11.11 Non-Regulatory Tools • • • • "
11.11.1 Key Characteristics of Non-Regulatory Tools ''-«^
11.11.1.1 Financial I* r*
11.11.1.2 Institutional \*-\A
11.11.1.3 Technical ""™
11.11.2 Other Characteristics }} ^
11.11.3 Limits . . 1V
1-
11-5
11-5
11-5
11-6
11-6
11-6
11-7
11-7
1,1-7
11-8
11-8
11-8
11-8
11-8
11-9
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Table of Contents v
APPENDICES
Appendix A: Acronym List and Glossary of Mining Terms
Appendix B: Acid Mine Drainage
Appendix C: Mining Sites on the NPL
Appendix D: General Discussion of AppDcable or Relevant and
Appropriate Requirements at Superfund Mining Sites
Appendix E: X-Ray Florescence
Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional
Risk Assessment Guidance
Appendix G: Detailed Information on Mine Remediation Technologies
Appendix H: Innovative SITE Technologies
Appendix I: EPA Minfrig Contacts
Appendix J: Internet Resources
Appendix K: Land Disposal Restrictions Overview and Bibliography
Appendix L: Mine Waste Technology Program
Appendix M: Remediation References
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Chapter 1
Introduction
1.1 Introduction
The Abandoned Mine Site Characterization and Cleanup Handbook (Handbook) has been
developed by the Environmental Protection Agency as a resource for project managers working
on addressing the environmental concerns posed by inactive mines and mineral processing
sites. The information contained in the Handbook is not policy or guidance, rather it a
compendium of information gained during many years of experience on mine site cleanup
projects. This information was developed primarily for EPA staff, but may also prove useful to
others working on mine site characterization and cleanup projects, including: states, other federal
agencies, tribes, local government, public interest groups, and private industry. Handbook users
are encouraged to refer to appropriate agency guidance and/or policy during development of site
specific mine site investigation and cleanup projects.
Earlier drafts of this document focused on the tools available for mine site cleanup under the
authorities of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA). However, with the recent release of EPA's National Hardrock Mining Framework, the
agency has stated its preference that a broad range of regulatory and non-regulatory tools be
considered in implementing inactive mine site cleanup projects. Consistent with the recognition
of the need fora more flexible approach, the title Superfund Mine Waste Reference Document,
has been replaced.
This handbook focuses on environmental hazards at abandoned mining sites. At many sites,
however, physical hazards (e.g., open shafts or adits, unstable buildings, unstable slopes, etc.)
present a safety hazard to the investigators and/or general public. These safety hazards also
deserve careful consideratbn in developing site management strategies but are not considered
in this document. • •'•
EPA's National Hardrock Mining Framework emphasizes the need for developing partnerships in
addressing the environmental concerns posed by inactive mines. This manual reflects the same
philosophy. Effective partnerships will assist in dealing with the difficult issues often posed by
mine sites, including: extensive areas of contamination, complex land ownership patterns, liability
issues, overlapping jurisdictions, and long term management considerations. Often in evaluating
cleanup options at mine sites, a watershed approach to assessing environmental impacts will be
required to understand the scope of potential problems and design appropriate solutions.
Partnerships can facilitate the design of cleanup strategies that address multiple interests within
a watershed. Collaborative efforts to set priorities for mine site cleanup, coupled with utilization
of the appropriate mix of regulatory and non-regulatory tools for getting the work done, should
result in successful projects.
Because this handbook was originally written for use by CERCLA program staff there are
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1-2 Chapter 1: Introduction
frequent references to guidance or other references developed under the auspices of Superfund.
This does not suggest that CERCLA authorities are to be applied at each abandoned mine site.
Rather, these references are provided to the reader as resources to be considered in developing
site characterization and cleanup strategies under whatever regulatory or non-regulatory
approach that is appropriate at a particular site. Experience has demonstrated that the
conceptual framework utilized in the CERCLA process is effective in investigating environmental
concerns and identifying appropriate cleanup actions; however users of this Handbook are
encouraged to consider the information provided here in the context of site specific
considerations.
1.2 Contents of Handbook
The Abandoned Mine Site Impact Characterization and Cleanup Handbook is divided into several
chapters, each dealing with an issue that is important in either site investigation, cleanup, or
long-term management.
Chapter 1: Introduction, this chapter, introduces the Handbook to readers.
Chapter 2: Overview of Mining and Mineral Processing Operations introduces users to the
types of operations, related wastes, and waste management practices typical of mine sites and
mineral processing facifities. Knowledge of the historical operations that took place on the site
will aid the project manager during site scoping, site characterization, and the cleanup alternative
selection process.
Chapter 3: Environmental Impacts from Mining introduces site managers to the types of
impacts abandoned mining operations can have on the environment. Knowledge of these
impacts wHI be important during site scoping, characterization, and cleanup alternative selection.
This background information provides valuable insight into the contaminants that maybe
present, potential threats to human health and the environment, and feasibility of response
actions.
Chapter 4: Setting Goals and Measuring Success outlines considerations in setting goals for
mine site cleanup and in assessing the success of mine site cleanup initiatives. The chapter
covers the coordination among federal and state agencies in determining the goals that need to
be met and resolving conflicts between different goals in different agencies. The chapter further
discusses how a site manager can "measure" the success of meeting the goals that were set for
the site.
Chapter 5: Community Involvement at Mining Waste Sites provides information regarding
community involvement planning for site investigation and cleanup work at mining waste sites.
Community involvement planning should parallel all aspects of the site cleanup process from the
onset of scoping to conclusion of site work. While the relevant public participation requirements
of the statutes under which the cleanup is taking place must be met, these activities represent
only a starting point for community involvement at many sites. Additional guidance on Superfund
community involvement requirements and other community involvement activities can be found in
Superfund Community Involvement Handbook & Toolkit.
Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas provides an
overview of the scoping process at abandoned mining and mineral processing sites. The first
section of the chapter presents background information on the scoping process in general. The
individual tasks associated with the scoping process can be found in Chapter 2 of the Guidance
for Conducting Remedial Investigations and Feasibility Studies Under CERCLA. The remainder
of the chapter addresses the problems and issues the site manager should consider when
scoping an abandoned mining or mineral processing site.
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Chapter 1: Introduction 1-3
Chapter 7: Sampling and Analysis of Impacted Areas outlines concepts and issues related to
designing and implementing a sampling and analysis program for characterizing mining and
mineral processing site waste managertfentareas, Th| cK|pter presents general information
about the sampling and analysis process. The individual tlsks associated with sampling and
analysis can be found in Chapters 3 and 4 of the Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA Mining and mineral processing sites
present many problems and issues that are not characteristic of other sites. The chapter
presents unique characteristics of mining and mineral processing sites and briefly discuss how
these characteristics can affect the sampling and analysis program. The remainder of the
chapter addresses issues associated with samplhg and analysis at abandoned mining and
mineral processing sites. ;
Chapter 8: Scoping and Conducting Ecological and Human Health Risk Assessments at
Superfund Mine Waste Sites discusses environmental and human health considerations in risk
assessment development. While not all mine sites will require that a risk assessment be
completed, the process to determine risk will be similar to the CERCLA process that is presented
here. The chapter highlights some of the unique issues related to risk assessments at mine
waste sites and provides some guidance to help address these issues. This chapter furnishes
Remedial Project Managers (RPMs), Site Assessment Managers (SAMs), Removal Managers,
and other federal and state authorities with a summary of key issues relevant to mine waste site
risk assessments as well as a compilation of references to other helpful resources.
Chapter 9: Site Management Strategies discusses options that a site manager may consider
for managing risk at abandoned mining and mineral processing sites. The site manager can be
a state, federal, tribal or local authority, or private landowner and be managing the site under a
number of regulatory or non-regulatory programs. The characterization of the site and the risk
assessment are used to identify the risks at the site. While these risks can be both
environmental or physical, this discussion will focus on the environmental risk. As with any
remediation project, strategic planning is critical in abandoned mine characterization initiatives as
well as clean-up activities.
Chapter 10: Remediation and Cleanup Options identifies remediation and cleanup options to
be considered in designing and implementing inactive mine site cleanup projects. The chapter
will assist the user with a basic understanding of the types and availability of cleanup
technologies for typical mining and mineral processing sites.
This chapter consists of three general sections. The first discusses technologies with
demonstrated effectiveness at mine sites. The second section focuses on emerging or
innovative technobgies. The third section addresses institutional controls. Finally the last
section identifies sources of information regarding available technologies and means of
accessing this information
Chapter 11: The Regulatory "Toolbox" discusses the tools available to project managers in
developing strategies for an abandoned mine site cleanup. Regulation of mining activities occurs
via a complex web of sometimes overlapping jurisdictions, laws, and regulations covering several
environmental media. Land ownership and tenancy issues further complicate regulatory
consideratbns. Each abandoned mine site faces a somewhat unique set of regulatory-
requirements, depending on statute or regulation; whether it is on State, Federal, Tribal, or
private land; local regulations; and the specific environmental considerations unique to the site.
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1-4 Chapter 1: Introduction
The chapter begins with a general discussion of the use of CERCLA for remediating mining and
mineral processing sites, then discusses applicabBity; implementation; enforcement; other
Superfund tools; limitations; ability to interact with other statutes, and interaction with federal
facilities. Finally, this chapter will discuss tools other than CERCLA that may be used at mining
sites, including non-regulatory programs and initiatives.
The appendices provide additional information and references of selected topics.
Users of the Handbook are reminded that mine site cleanup projects are conducted against a
complex backdrop of federal, state, tribal, and local regulations and policies. These often
change. Similarly, considerable effort is now being devoted to developing more cost effective
cleanup technologies for inactive mine sites. Therefore, readers are advised to refer to sources
listed in the references in conjunction with using this manual to be certain to have the most up to
date information available in designing site characterization and cleanup projects. Other sources
of information are Internet web pages, including those that can be reached through the EPA
home page at http://www.epa.gov.
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Chapter 2
Overview of Mining and Mineral Processing Operations
2. 1 Introduction
This chapter introduces users to the types of operations, waste streams, and waste
management practices typical of historic mine sites and mineral processing facilities.
Knowledge of the operating history of the site will be valuable during site scoping, site
characterization, and the cleanup alternative selection process. In addition, this knowledge will
assist in beating potential physical hazards, such as mine openings that may have become
obscured. Knowledge of the wastes and waste management practices will provide additional
insight into the potential threats to human health and the environment, as well as feasibility of
response actions.
The production of minerals for economic use involves a series of physical and chemical
processes. These may occur at any time from excavation of the ore that contains the metal in
mineral form through production of the metal in marketable form. Users should be aware that
mining terms have not been used consistently over the years. This can complicate the process
of identifying site histories and operations. Some particularly noteworthy instances where this
can occur are explained in the text.
The chapter is divided into sections addressing Mining (or "extraction"), Beneficiatipn (e. g. ,
milling and leaching), and Mineral Processing (e.g., smelting and refining). Each section in this
chapter begins with a discussion of processes followed by a discussion of wastes generated. It
is worthwhile to note that the three types of operations may or may not be co-located. For
example, in many mining districts, the beneficiation plant is located at a central location to serve
a number of individual mines with the concentrate being further transported to a remote
smelter. In contrast, other sites, such as Bunker Hill in Northern Idaho, had the mine,
concentrator, and smelter all located together. When mineral processing operations are co-
located with extraction and beneficiation operations, comingiing of relatively small quantities of
mineral processing waste with beneficiation waste often has occurred. This is important due to
the physical characteristics of the waste , as well as the applicable waste management
regulations.
The definition of a mine site may be broad. EPA, in its Clean Water Act effluent limitation
guidelines for discharges from mines, has defined a mine as an area of land upon or under
which minerals or metal ores are extracted from natural deposits in the earth by any methods,
including the total area upon which such activities occur or where such activities disturb the
natural land surface. A mine, under this definition, also includes land affected by ancillary
operations that disturb the natural land surface, and can include adjacent land whose use is
more incidental to mining activities (e. g. , roads, workings, impoundments, dams, ventilation
shafts, drainage tunnels, refuse banks, dumps, stockpiles, overburden piles, spoil banks,
tailings, holes or depressions, structures, or facilities).
s
2.2 Mining
The initial step of the mining and mineral processing operations is the actual removal of the
mineral value in ore from the host rock or matrix. Minerals may be extracted from the earth
using a variety of techniques (note that the term extraction also may be used within the industry
to describe pyrometailurgical and metallurgical processes—that is outside this mining definition).
Most extraction processes result in the removal of ore and associated rock or matrix in bulk
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2-2 Chapter 2: Overview of Mining and Mineral Processing Operations
form from the deposit, using blasting and various mechanical means to break the ore into
pieces of manageable size or to separate the ore minerals from unwanted material.
In the interest of economic efficiency, the extraction process is designed to remove ore of a
predetermined grade or higher, leaving behind as much of the lower grade ore and barren rock
as possible. Because this ideal separation is not always possible in practice, some lower grade
rock is mined while some higher grade ore is left behind. It is important to note that the term
"ore" is an economic one. In general, ore is earthen material that contains minerals of sufficient
value to be extracted economically. Because the value of a mineral can change rapidly and
substantially, the distinction between "ore" and other mined materials (which generally contain
mined values that cannot be economically extracted at the time) is also variable, both from
mine to mine and, for any specific mine, over time.
2. 2.1 Types of Mining Processes
Mining can be categorized as surface mining, underground mining, and in situ mining. Surface
mining is used to excavate ores at or close to the earth's surface; included in surface mining
are open pit mining, highwall or strip mining used to excavate coal or other deposits
(abandoned coal mines are not addressed in this handbook), and dredging to excavate placer
deposits. Underground and in situ mining both remove minerals from deeper deposits, the
former by extracting under the surface and removing the ore and the latter by sinking injection,
and extraction wells and leaching the ore in place.
Open Pit Mining. Surface mining with open pits has become the primary type of mining
operation for most of the major metallic ores in the United States. It is the method of choice
when the characteristics of the ore deposit (e. g. grade, size, location) make removing
overburden (i. e., host rock overlying the mineral laden ore) cost effective. At present, this is
the most economical way of mining highly disseminated (i. e., lower-grade) ores. Open pit
mining involves excavation of an area of overburden and removal of the ore exposed in the
resulting pit. Depending on the thickness of the orebody, it may be removed as a single vertical
interval or in successive intervals or benches. With the larger orebodies common to metals
mining, the orebody typically is mined 'm benches either by drilling vertical holes from the top of
the bench and blasting the ore onto the adjacent lower level or, in less resistant materials, by
excavating with digging/scraping machinery without the use of explosives.
Explosives typically used in open pit mining are comprised of chemicals which, when combined,
contain all the requirements for complete combustion without oxygen supply. Early explosives
consisted chiefly of nitroglycerine, carbonaceous material and an oxidizing agent. These
mixtures were packaged "mto cartridges for convenience in handling and loading into drill holes.
In recent years, fertilizer-grade ammonium nitrate mixed with about six percent fuel oil was
recognized as an explosive capable of being detonated with a high explosive primer. This
application has spread to the point where virtually all open-pit mines use this mixture (called
ANFO) for primary blasting.
Dredging. Dredging is another method of surface mining that has been used to mine placer
deposits, which are concentrations of heavy metallic minerals that occur in sedimentary
deposits associated with current or ancient watercourses. In some mining districts, widespread
stream disturbance by placer mining or dredging may be present alongside the other
disturbances from underground mining, beneficiation, and/or mineral processing. Commercial
dredging has not been widely practiced in the United States in the 1990's, although placer
mining is still an important industry in Alaska. Some abandoned large-scale dredge operations
remain in the western United States, and in some cases the dredges are still present in the
dredge ponds created as part of the operation.
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. Chapter 2: Overview of Mining and Mineral Processing Operations 2-3
Underground Mining. Underground mining has been the major method for the production of
certain metals but in recent years has been increasingly less common in the United States.
The mid-1990's have seen a mild resurgence of underground mining as the depths of several
major open pit mines have reached their economic limit. Underground mining typically has
significantly less impact on the surface environment than do surface methods. This is primarily
the result of reduced surface disturbance (i.e., a smaller facility "footprint") and the much lower
quantities of non-ore materials that must be removed and disposed as waste. Large
underground workings, when abandoned, have sometimes caused subsidence or caving at the
surface, resulting in disturbance to structures, roads, and surface water drainages. In addition,
drainage from underground mines may cause significant alteration to the quality of ground
water and can affect surface water as well. Mine drainage water quality is highly dependent on
the characteristics of host rock and can vary widely.
In Situ Solution Mining. In situ mining is a method of extracting minerals from an orebody
that is left in place rather than being broken up and removed. (Ex situ leaching operations,
discussed as beneficiation in Section 2. 4, operate on the same principal but with excavated
ore.) In general, a series of wells are drilled into the orebody and a solvent circulated through
the formation by injection through certain wells and withdrawal through others. Although in situ
solution mining is not commonly use.d, it has been applied to uranium and copper deposits in
suitable hydrogeologic settings. Although there is little disturbance of the surface and
underground at an in situ operation, the effect of the operation on the groundwater quality can
be significant as the chemistry of the ground water must be drastically altered by the introduced
solvents and the pumping operation. Furthermore, other materials in addition to the target
minerals may be dissolved with the potential for affecting the local ground water, and,
depending on their mobility, surrounding areas.
Surface operations include management of barren solution (i.e., leachate prior to injection) and
pregnant leachate (leachate withdrawn and containing the mineral value) in surface
impoundments or, more recently, tanks.
2. 2. 2 Mining Wastes and Hazardous Materials
The largest quantity of wastes generated by extraction operations are mine water and waste
rock. A third waste material, overburden, is generated at surface mines. Note that the use of
the terms "mining waste" and "waste management unit" in this document do not imply that all
the materials in question are solid wastes as defined by the Resource Conservation and
Recovery Act (RCRA). Wastes from extraction and beneficiation continue to be excluded
broadly from regulation as hazardous waste, although they are regarded as solid waste;
overburden, as noted beiow, has an additional exclusion.
Overburden. Overburden is the surface material (i.e., topsoil and rock) removed during
surface mining operations to expose the ore beneath. In recent years, mine management
plans required by States and by Federal land management agencies require that topsoii be
salvaged and stockpiled for use in reclamation during closure or decommissioning.
Overburden is specifically exempted from being regulated as a RCRA hazardous waste when it
is "returned to the mine site" (40 CFR 26I. 4(b)(3)).
Mine Water. Water entering a surface or underground mine is referred to as mine water.
Sources of this water are groundwater seepage, surface water inflowror direct precipitation. In
the absence of a natural or manmade drainage, active mine operations below the water table
must pump out mine water to access the orebody. Depending on the hydrogeology of the mine
this can be accomplished as simply pumping the water from the mine to grouting the rock in the
mine to prevent inflow to using a series of extraction wells around a mine to create a cone of
gangue to yield a product that has a much higher content of the valued material. Beneficiation
milling operations are functionally categorized as either comminution, in which the mined ore is
crushed and ground to physically liberate the target mineral, or concentration. Concentration is
the separation of the mineral values liberated by comminution from the rest of the ore. These
separation steps, often conducted in series, utilize the physical differences between the
valuable mineral and the host rock to achieve separation and produce a concentrate containing
the valuable minerals and a tailing containing the waste material and reagents. Many physical
properties, including the following, are used as the basis for separating valuable minerals from
gangue: specific gravity, conductivity, magnetic permeability, affinity for certain chemicals, and
solubility in a leachate (leaching is discussed in Section 2. 4). Types of processes that affect
separation include gravity concentration, magnetic separation, electrostatic separation, and
flotation.
Gravity Concentration. Gravity-concentration processes exploit differences in density to
separate ore minerals from gangue. Selection of a particular gravity-based process for a given
ore will be strongly influenced by the size to which the ore must be crushed or ground to
separate values from gangue, as well as by the density difference and other factors, in
general, the first two methods were historically used in the recovery of gold.
Coarse/Fine Concentration. Separation in this step involves particle density rather
than size. Sluices are commonly used in this step, although jigs and screens may also
be employed. The heavy minerals settle within the lining material of the sluice, while the
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2-4 Chapter 2: Overview of Mining and Mineral Processing Operations
depression in the ground water table, thereby reducing infiltration. At some mines enormous
quantities may have to be pumped continuously from the mine during operations. Active mines
may use mine water for dust control and as process water in the mill circuit; otherwise they
typically discharge the flow to surface water under a National Pollutant Discharge Eliminatbn
System (NPDES) permit or similar state permit. Mine water discharge from operating mines is
typically regulated and often does not have the residence time in the ore or mine needed to
create highly acidic waters or waters highly-loaded with dissolved metals. However, the need
to treat mine water prior to discharge is highly site specific.
When a mine closes, dewatering the mine generally ceases. Underground mines often fill;
mine water may be released through openings such as adits, or through fractures and fissures
that reach the surface. If present, man-made gravity drains will continue to flow. Surface
mines that extend below the water table wjil return to that level when pumping ceases, either
forming a lake h the pit or inundating and saturating fill material. Recovery of ground water to
or near pre-mining levels following the cessation of pumping can take substantial amounts of
time, however, and the effects resulting from ground water drawdown may continue to be felt
for decades.
Water from abandoned mines may contain significant concentrations of heavy metals and total
dissolved solids and may have elevated temperatures and altered pH, depending on the nature
of the orebody and local geochemical conditions. These waters may become acidic over time
when exoosed to oxygen ancUfjaresent. pyrites or other^ulfid^^
2-6 Chapter 2: Overview of Mining and Mineral Processing Operations
slurry waste that is discharged to a tailings pond or undergoes further concentration.
After coarse concentration, most waste material has been removed, leaving a
concentrate. The concentrate may then be subjected to fine concentration methods,
including jigs, spiral classifiers, shaking tables, and pinched sluices. The waste at this
stage is a slurry. Amalgamation sometimes followed fine concentration.
Highlight 2-1
Carson River Mercury
The Carson River Mercury Site consists of a 50-mile
stretch of the Carson River, downstream of Carson
City, Nevada. The site has been contaminated by
mercury used in the amalgamation of gold and silver.
In the late 1800s, large amounts of mercury were
used during the milling of the Comstcck Lode near
Virginia City. Gold mining and processing began in
the late 1880's. An estimated 7,500 tons of mercury
were lost during the processing. Mercury has
contaminated the hundreds of tailings piles and the
Carson River sediments.
Amalgamation. Native gold or free
gold can be extracted by using liquid
mercury to form an amalgam. The
gold is then recovered by filtering the
amalgam through a canvas cone to
drain off the excess mercury.
Although the amalgamation process
has, in the past, been used
extensively for the extraction of gold
from pulverized ores and placer
gravels, it has largely been
superseded in recent years by
cyanidatfon processes (i.e. leaching).
The current practice of amalgamation
in the United States is limited to small-scale barrel amalgamation of a relatively small
quantity of high-grade, gravity-concentrated gold ore. The amalgam is then retorted to
separate the gold and mercury. Historically, the methods used to obtain the amalgam
allowed some of the mercury/amalgam to escape the process. Several Superfund sites
(notably Carson River, see Highlight 2-1) have experienced severe mercury
contamination from amalgamation.
Sink/Float Separation. Sink/float separation, also knpwn as heavy media separation,
uses buoyancy forces to separate the various minerals on the basis of density. The ore
is fed to a tank containing a medium whose density is higher than that of the gangue
and less than that of the valuable ore minerals. As a result, the gangue floats and
overflows the separation chamber, and the denser values sink and are drawn off at the
bottom. Media commonly used for sink/float separation in the ore milling industry are
suspensions of very fine ferrosjlicon or galena (PbS) particles. The float material
(waste) may be used for other applications, such as aggregate, since it is already
crushed. ' \l
Magnetic Separation. Magnetic separation is applied in the ore milling industry, especially the
beneficiating ores of iron, columbium and tantalum, and tungsten, both for extraction of values
from ore and for separation of different valuable minerals recovered from complex ores.
Separation is based on differences in magnetic permeability (which, although small, is
measurable for almost all materials) and is effective in handling materials not normally
considered magnetic. The basic process involves transport of ore through a regbn of high
magnetic-field gradient where the most magnetically permeable particles are attracted to a
moving surface, behind which is the pole of a large electromagnet. These particles are carried
out of the main stream of ore and released into a conveyance leading to further processing.
Although dry separators are used for rough separations, drum separators are most often run
wet on the slurry ground in the mill.
Electrostatic Separation. Electrostatic separation is used to separate minerals on the basis of
their conductivity. This process is inherently dry and uses very high voltages. In a typical
application, ore is charged at 20,000 to 40,000 volts, and the charged particles are dropped
-------
. Chapter 2: Overview of Mining and Mineral Processing Operations 2-3
Underground Mining. Underground mining has been the major method for the production of
certain metals but in recent years has been increasingly less common in the United States.
The mid-1990's have seen a mild resurgence of underground minrig as the depths of several
major open pit mines have reached their economic limit. Underground mining typically has
significantly less impact on the surface environment than do surface methods. This is primarily
the result of reduced surface disturbance (i.e., a smaller facility "footprint") and the much lower
quantities of non-ore materials that must be removed and disposed as waste. Large
underground workings, when abandoned, have sometimes caused subsidence or caving at the
surface, resulting in disturbance to structures, roads, and surface water drainages. In addition,
drainage from underground mines may cause significant alteration to the quality of ground
water and can affect surface water as well. Mine drainage water quality is highly dependent on
the characteristics of host rock and can vary widely.
In Situ Solution Mining. In situ mining is a method of extracting- minerals from an orebody
that is left in place rather than being broken up and removed. (Ex situ leaching operations,
discussed as beneficiation in Section 2. 4, operate on the same principal but with excavated
ore.) In general, a series of wells are drilled into the orebody and a solvent circulated through
the formation by injection through certain wells and withdrawal through others. Although in situ
solution mining is not commonly use.d, it has been applied to uranium and copper deposits in
suitable hydrogeologic settings. Although there is little disturbance of the surface and
underground at an in situ operation, the effect of the operation on the groundwater quality can
be significant as the chemistry of the ground water must be drastically altered by the introduced
solvents and the pumping operation. Furthermore, other materials in addition to the target
minerals may be dissolved with the potential for affecting the local ground water, and,
depending on their mobility, surrounding areas.
Surface operations include management of barren solution (i.e., leachate prior to injection) and
pregnant leachate (leachate withdrawn and containing the mineral value) in surface
impoundments or, more recently, tanks.
2. 2. 2 Mining Wastes and Hazardous Materials
The largest quantity of wastes generated by extraction operations are mine water and waste
rock. A third waste material, overburden, is generated at surface mines. Note that the use of
the terms "mining waste" and "waste management unit" in this document do not imply that all
the materials in question are solid wastes as defined by the Resource Conservation and
Recovery Act (RCRA). Wastes from extraction and beneficiation continue to be excluded
broadly from regulation as hazardous waste, although they are regarded as solid waste;
overburden, as noted below, has an additional exclusion.
Overburden. Overburden is the surface material (i.e., topsoil and rock) removed during
surface mining operations to expose the ore beneath. In recent years, mine management
plans required by States and by Federal land management agencies require that topsoil be
salvaged and stockpiled for use in reclamation during closure or decommissioning.
Overburden is specifically exempted from being regulated as a RCRA hazardous waste when it
is "returned to the mine site" (40 CFR 26I. 4(b)(3)).
Mine Water. Water entering a surface or underground mine is referred to as mine water.
Sources of this water are groundwater seepage, surface water inflow^or direct precipitation. In
the absence of a natural or manmade drainage, active mine operations below the water table
must pump out mine water to access the orebody. Depending on the hydrogeology of the mine
this can be accomplished as simply pumping the water from the mine to grouting the rock in the
mine to prevent inflow to using a series of extractbn wells around a mine to create a cone of
-------
2-4 Chapter 2: Overview of Mining and Mineral Processing Operations
depression in the ground water table, thereby reducing infiltration. At some mines enormous
quantities may have to be pumped continuously from the mine during operations. Active mines
may use mine water for dust control and as process water in the mill circuit; otherwise they
typically discharge the flow to surface water under a National Pollutant Discharge Elimination
System (NPDES) permit or similar state permit. Mine water discharge from operating mines is
typically regulated and often does not have the residence time in the ore or mine needed to
create highly acidic waters or waters highly-loaded with dissolved metals. However, the need
to treat mine water prior to discharge is highly site specific.
When a mine closes, dewatering the mine generally ceases. Underground mines often fill;
mine water may be released through openings such as adits, or through fractures and fissures
that reach the surface. If present, man-made gravity drains will continue to flow. Surface
mines that extend below the water table wjll return to that level when pumping ceases, either
forming a lake h the pit or inundating and saturating fill material. Recovery of ground water to
or near pre-mining levels following the cessation of pumping can take substantial amounts of
time, however, and the effects resulting from ground water drawdown may continue to be felt
for decades.
Water from abandoned mines may contain significant concentrations of heavy metals and total
dissolved solids and may have elevated temperatures and altered pH, depending on the nature
of the orebody and local geochemical conditions. These waters may become acidic over time
when exposed to oxygen and, if present, pyrites or other sulfide minerals. The acidic water
may also solubilize metals contained in the mine and mined materials, creating high
concentrations of metals in solution. These acidic metal-laden waters may contaminate down-
gradient ground-water and surface water resources. Neutral and alkaline mine waters may also
contain metals in excess of water quality standards and be of significant concern to human
health and the environment.
Waste Rock. Waste rock consists of non-mineralized and low-grade mineralized rock removed
from, around, or within the orebody during extraction activities. The cutoff grade that
differentiates low-grade waste rock from useable ore is an economic distinction and may vary
over time (see above). Therefore, what may have been disposed as waste rock (or stored as
"sub-ore", "proto-ore" or low grade ore") in the past may be ore at another time.
Waste rock includes granular, broken rock and soils ranging in size from fine sand to large
boulders, with the content of fine material largely dependent on the nature of the formation and
the extraction methods employed during mining. Waste rock is typically disposed in large piles
or dumps adjacent to and/or down-slope of the point of extractbn; waste rock frequently can be
seen in close proximity to old mine shafts and openings. These sites historically were in
locations of natural drainage; surface water run-on and infiltration have caused natural
leaching from the waste rock piles. Waste rock has often been used on the mine site for fill,
tailings dams, or other construction purposes. Current operations frequently use engineering
controls to prevent run-on (e. g., diversion systems) or run-off (drainage systems installed
during construction); retrofitting waste rock sites at abandoned mines with surface water
controls is often necessary for controlling waste rock impacts at abandoned mines.
Waste rock geochemistry varies widely from mine to mine and may vary significantly at
individual mines over time as differing iithotagic strata are exposed and geochemical processes
alter characteristics of the waste. Waste rock at metal mines will contain some concentration of
the target mineral along with other metals. The mobility of any particular constituent of waste
rock is highly dependent on site specific conditions, such as climate, hydrology, geochemistry
of the disposal unit and its foundation, mineralogy, and particle size. Waste rock from metal
mines often contains sulfitic materials as components of the host rock. The concentration of
-------
Chapter 2: Overview of Mining and Mineral Processing Operations 2-5
sulfide minerals and of neutralizing minerals is an important factor in the potential for waste
rock to generate acid drainage.
If prone to acid generation, such uses cati liad to condemn ibout widespread contamination,
acid generation, or other long-term problems. Site scoping activities often includes identifying
and mapping locations where these uses "occurred.
2. 3 Beneficiation: Milling
Following the initial mining step, ore-is reduced in size by the crushing and/or grinding circuit,
and the target mineral is concentrated by various methods. These widely varying concentration
processes are collectively referred to as beneficiatbn. Ore dressing and milling typically refer
to a specific subset of operations under beneficiation and are the focus of this section.
Leaching, also considered by EPA (under the RCRA program) to be beneficiation, is discussed
separately in Section 2. 4.
In general, the criteria established by EPA (under the RCRA program) describe beneficiation as
activities that serve to separate and concentrate the mineral values from waste material,
remove impurities, or prepare the ores for further refinement. Beneficiation activities generally
do not change the mineral values themselves other than by reducing (e. g. , crushing or
grinding) or enlarging (e. g., pelletizing or briquetting) partide size to facilitate processing.
Generally, no chemical changes occur in the mineral value during beneficiation. (Beneficiation
operations may be referred to as "processing" in the older literature and occasionally by
industry today.)
2. 3. 1 Types of Beneficiation (Milling) Processes
Most ores contain the valuable metals disseminated in a matrix of less valuable rock called
gangue The purpose of ore beneficiatbn is the separation of valuable minerals from the
gangue to yield a product that has a much higher content of the valued material. Beneficiation
milling operations are functionally categorized as either comminution, in which the mined ore is
crushed and ground to physically liberate the target mineral, or concentration. Concentration is
the separation of the mineral values liberated by comminution from the rest of the ore. These
separation steps, often conducted in series, utilize the physical differences between the
valuable mineral and the host rock to achieve separation and produce a concentrate containing
the valuable minerals and a tailing containing the waste material and reagents. Many physical
properties including the following, are used as the basis for separating valuable minerals from
gangue: specific gravity, conductivity, magnetic permeability, affinity for certain chemicals, and
solubility in a leachate (leaching is discussed in Section 2. 4). Types of processes that affect
separation include gravity concentration, magnetic separation, electrostatic separation, and
flotation.
Gravity Concentration. Gravity-concentration processes exploit differences in density to
separate ore minerals from gangue. Selection of a particular gravity-based process for a given
ore will be strongly influenced by the size to which the ore must be crushed or ground to
separate values from gangue, as well as by the density difference and other factors. In
general, the first two methods were historically used in the recovery of gold.
Coarse/Fine Concentration. Separation in this step involves particle density rather
than size. Sluices are commonly used in this step, although jigs and screens may also
be employed. The heavy minerals settle within the lining material of the sluice, while the
lighter material is washed through. Most of the material that enters the sluice exits as
-------
2-6 Chapter 2: Overview of Mining and Mineral Processing Operations
slurry waste that is discharged to a tailings pond or undergoes further concentration.
After coarse concentration, most waste material has been removed, leaving a
concentrate. The concentrate may then be subjected to fine concentration methods,
including jigs, spiral classifiers, shaking tables, and pinched sluices. The waste at this
stage is a slurry. Amalgamation sometimes followed fine concentration.
Highlight 2-1
Carson River Mercury
The Carson River Mercury Site consists of a 50-mile
stretch of the Carson River, downstream of Carson
City, Nevada. The site has been contaminated by
mercury used in the amalgamation of gold and silver.
In the late 1800s, large amounts of mercury were
used during the milling of the Comstock Lode near .
Virginia City. Gold mining and processing began in
the late 1880's. An estimated 7,500 tons of mercury
were lost during the processing. Mercury has
contaminated the hundreds of tailings piles and the
Carson River sediments.
Amalgamation. Native gold or free
gold can be extracted by using liquid
mercury to form an amalgam. The
gold is then recovered by filtering the
amalgam through a canvas cone to
drain off the excess mercury.
Although the amalgamation process
has, in the past, been used
extensively for the extraction of gold
from pulverized ores and placer
gravels, it has largely been
superseded in recent years by
cyanidation processes (i.e. leaching).
The current practice of amalgamation
in the United States is limited to small-scale barrel amalgamation of a relatively small
quantity of high-grade, gravity-concentrated gold ore. The amalgam is then retorted to
separate the gold and mercury. Historically, the methods used to obtain the amalgam
allowed some of the mercury/amalgam to escape the process. Several Superfund sites
(notably Carson River, see Highlight 2-1) have experienced severe mercury
contamination from amalgamation.
Sink/Float Separation. Sink/float separation, also known as heavy media separation,
uses buoyancy forces to separate the various minerals on the basis of density. The ore
is fed to a tank containing a medium whose density is higher than that of the gangue
and less than that of the valuable ore minerals. As a result, the gangue floats and
overflows the separation chamber, and the denser values sink and are drawn off at the
bottom. Media commonly used for sink/float separation in the ore milling industry are
suspensions of very fine ferrosilicon or galena (Pb'S) particles. The float material
(waste) may be used for other applications, such as aggregate, since it is already
crushed.
Magnetic Separation. Magnetic separation is applied in the ore milling industry, especially the
beneficiating ores of iron, columbium and tantalum, and tungsten, both for extraction of values
from ore and for separation of different valuable minerals recovered from complex ores.
Separation is based on differences in magnetic permeability (which, although small, is
measurable for almost all materials) and is effective in handling materials not normally
considered magnetic. The basic process involves transport of ore through a regbn of high
magnetic-field gradient where the most magnetically permeable particles are attracted to a
moving surface, behind which is the pole of a large electromagnet. These particles are carried
out of the main stream of ore and released into a conveyance leading to further processing.
Although dry separators are used for rough separations, drum separators are most often run
wet on the slurry ground in the mill.
Electrostatic Separation. Electrostatic separation is used to separate minerals on the basis of
their conductivity. This process is inherently dry and uses very high voltages. In a typical
application, ore is charged at 20,000 to 40,000 volts, and the charged particles are dropped
onto a conductive rotating drum. The conductive particles lose their attractive charge very
-------
Chapter 2: Overview of Mining and Mineral Processing Operations 2-7
rapidly and are thrown off and collected, while the non-conductive particles keep their charge
and adhere by electrostatic attraction. They may then be removed from the drum separately.
Flotation. Flotation is a process by which trie addition of cfiemicals to a crushed ore-water.
slurry causes particles of one mineral or. group of minerals to adhere to air bubbles. When air
is forced through the slurry, the rising |)ubbles carry withtjieprijhe particles of the mineral(s)to
be separated from the matrix. A foaTrrnig^lient is added'IfHf prevents the bubbles from
bursting when they reach the surface; a layer of mineral-laden foam is built up at the surface of
the flotation cell and this is removed to recover the mineral.
Flotation concentration has become-a mainstay of trie metal ore milling industry because it is
adaptable to very fine particle sizes. It afeo allows for high rates of recovery from slimes, which
are generated in crushing and grinding and which are not generally amenable to physical
processing. As a physical- chemical surface phenomenon, this process can often be made
highly specific, thereby allowing production of high-grade concentrates from very low-grade ore
(e. g., more than 95 percent MoS2 concentrate from 0. 3 percent ore). Its specificity also
allows separation of different ore minerals (e. g. , CuS, PbS, and ZnS) where desired, as well
as operation with minimum reagent consumption because reagent interaction typically occurs
only with the particular materials to be floated or depressed.
Details of the flotation process (e. g. , exact type and dosage of reagents, fineness of grinds,
number of regrinds, cleaner-flotation steps) differ at each operation where it is practiced and
may often vary with time at a given mill. A complex system of reagents is generally used,
including five basic types of compounds: pH conditioners (regulators, modifiers), collectors,
frothers, activators, and depressants. At large-capacity mills, the total reagent usage can be
high even though only small quantities are needed per ton of ore, since tens of thousands of
tons of ore per day may be beneficiated. The reagents often remain in the waste water,
allowing the usage to be lowered by recycling the water. The reagents in the waste water may
however impact some of the other steps in the process, prohibiting the water from being
recycled.
Sulfide minerals are all readily recovered by flotation using similar reagents in small doses,
although reagent requirements and ease of flotation do vary throughout the class. Sulfide.
flotation is most often carried out at alkaline pH. Sulfide minerals of copper, lead, zinc,
molybdenum, silver, nickel, and cobalt are commonly recovered by flotation. Non-sulfitic ores
also may be recovered by flotation, including oxidized ores of iron, copper, manganese, the
rare earths, tungsten, titanium, and coiumbium and tantalum. Generally, the flotation
processes for oxides are more sensitive to feed-water conditions than sulfide floats;
consequently, oxidized ores can run less frequently with recycled water. Flotation of these ores
involves very different reagents from suifide flotation. The reagents used include fatty acids
(such as oleic acid or soap skimmings), fuel oil, and various amines as collectors, as well as
compounds (such as copper sulfate, acid dichromate, and sulfur dioxide) as conditioners.
2. 3. 2 Beneficiation (Milling) Wastes and Hazardous Materials
The wastes generated by beneficiatbn milling operations are collectively known as tailings.
Readers should also be aware that unused or discarded chemicals associated with these
beneficiation operations at historic mining sites also may remain onsite and need to be
managed during remediation. These could include: mercury at sites that have used
amalgamation and chemicals used in flotation such as copper sulfate, various amines, and
sodium cyanide.
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2-8 Chapter 2: Overview of Mining and Mineral Processing Operations
Tailings. Tailings are the waste portions of mined material that are separated from the target
mineral(s) during benefia'ation. By far the larger proportion of ore mined in most industry
•sectors ultimately becomes tailings that must be disposed. In the gold industry, for example,
only a few hundredths of an ounce of gold may be produced for every ton of dry taflings
generated. Similarly, the copper industry typically mines relatively low-grade ores that contain
less than a few percent of metal values; the residue becomes tailings. Thus, tailings disposal is
a significant portion of the overall waste management practice at mining and milling operations.
The physical and chemical nature of tailings is a function of the ore being milled and the milling
operations used to beneficiate the ore. The method of tailings disposal is largely controlled by
the water content of the taifings. Generally, three types of tailings may be identified based on
their water content: wet, thickened, and dry. The type of tailing is less important from a
remediation perspective than from an active management perspective, although knowledge of
the type of tailings may help site managers characterize the material and better understand the
potential remediation alternatives.
Although the tailings have much lower concentrations of the target mineral(s) than in the mined
ore, they may be a source of contamination at the site due to the presence of sulfides such as
pyrite (acid generation), metals (available for mobilization in ground or surface waters), and
reagents added during beneficiatbn. Tailings that are fine grained and managed under drier
conditions are especially prone to producing dust. Sulfide tailings oxidized by weathering are
potential generators of acidic runoff.
In the past, and at present in some other countries, tailings often were disposed where
convenient. The tailings were discharged into rivers jf flow was sufficient, held behind dams if
necessary, or placed on land. In the U.S., tailings now are managed, wet or thickened, in
tailings impoundments or dry in disposal piles. In addition to placement in management units,
certain tailings may beslurried as backfill into underground mines.
Tailings impoundments. Wet tailings are slurried to tailings and settling ponds, where excess
liquid is evaporated or drained and the tailings allowed to dry. These impoundments may range
in size from under an acre to up to a thousand acres. While the thickness (I. e. , depth or
height) of these tailings impoundments may in some extreme cases be as much as 1,000 feet,
the thickness most commonly ranges from ten to fifty feet.
Four main types of slurry impoundment layouts are employed: valley impoundments, ring dikes,
in-pit impoundments, and specially dug pits (See Appendix A for Glossary terms). The stability
of tailing dams at abandoned mines represents a remediation concern. Historic methods of
tailings management included disposal into topographically low areas, often streams and
wetlands. To the extent that these areas became diked incidentally by the nature of their
deposition they are considered inactive impoundments for remediation planning.
Tailings Piles. Tailings may be dewatered or dried prior to disposal, thus reducing seepage
volume and the area needed for an impoundment or pile. Dry tailings piles are considerably
different from tailings piles created as a result of thickened tailings disposal. Dry tailings may
be disposed in a variety of pile configurations, including a valley-fill (I. e. , discharged to in-fill a
valley), side hill (disposed of on a side of a hill in a series of piles), and level pile deposition in
lifts that are continually added.
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Chapter 2: Overview of Mining and Mineral Processing Operations 2-9
Mine Backfilling. Slurried tailings may be disposed in underground mines as backfill to
provide ground or wall support, thereby decreasing the above-ground surface disturbance and
stabilizing mined-out areas. (Waste management econpmics may also drive deposition in
underground mines.) For stability reasons, Uneiergrouri backfilling generally requires tailings
that have a high permeability, low compressibility, and the ability to rapidly dewater (I. e., a
large sand fraction). As a result, often only the sand fraction of tailings is used as backfill.
Tailings may be cycloned to separate out the coarse sand fraction for backfilling, leaving only
the slimes to be disposed of iii an impoundment. To increase structural competence, cement
may be added to the sand fraction before backfilling. In the proper geologic setting, this
practice may have significant value to remediation teams looking to fill underground mines and
fissures to stop acidic mine water release while reducing tailings volume on the surface. In
other cases efforts to backfill or seal the mine could increase the risk of generating AMD.
Subaqueous Disposal. Underwater disposal in a permanent body of water, such as a lake,
ocean, or an engineered structure (e. g., a pit or impoundment), has been an historical
management practice and is stil practiced in some other countries (e. g., Canada). The
potential advantage to underwater disposal is the inhibition of oxidation of sulfide minerals in
tailings, thus preventing or slowing acid generation. Substantial uncertainty exists regarding
other short- and long-term effects on the water body into which the tailings may be disposed.
Regulations under the Clean Water Act (e. g. , the effluent limitation guidelines for mills that
beneficiate base and precious metal ores) effectively prohibit subaqueous disposal of tailings in
natural water bodies (i.e., any discharge to "waters of the U. S.").
2. 4 Beneficiation: Leaching
Leaching is the process of extracting a soluble metallic compound from an ore by selectively
dissolving it in a suitable solvent, such as water, sulfuric acid, or sodium cyanide solution. The
target metal is then removed from the "pregnant" leach solution by one of several
electrochemical or chemical means. (Note that digestion, where the ore concentrate is
digested completely or significantly by a strong liquor, is not considered leachnig under RCRA.
The significance of this difference is that wastes from digestipn are not excluded from
management as hazardous waste, while wastes from leaching operations are excluded. )
Specific solvents attack only one (or, at most, a few) ore constituent(s), including the target
metal or mineral. (Note that in situ mining is fundamentally the same leaching operation except
the ore is not excavated.) Ore may be crushed or finely ground to expose the desired mineral
prior to leaching. The taiings from a other beneficiation process, such as flotation, may be
leached to remove additional metal. Ores that are too low in grade to justify the cost of milling
may be recovered by dump or heap leaching.
2.4.1 Types of Processes Associated with Leaching
The leaching process consists of preleaching activities, the actual leaching operation, and the
recovery of the mineral value from the pregnant leach liquor. Each of these efforts is distinct
from the others and generates different types of waste streams.
Preleaching Activities. Depending on the grade of the ore and the type of leaching operation
for which the ore is intended, some preprocessing may be required. Most heap and dump
leach operations use ores that are not preprocessed other than by some comminution (e. g.
crushing). (Note that, under RCRA, EPA has included in the definition of beneficiation the
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2-10 Chapter 2: Overview of Mining and Mineral Processing Operations
activities of roasting, autoclaving, agglomeration, and/or chlorinating, in preparation for leaching;
wastes from these activities currently are exempted from regulation as hazardous wastes. )
Roasting. The activity of roasting ores is discussed because particulate materials from
roasting operations, known as fines, have been found to contribute to the environmental
impacts at several mine sites being remediated under CERCLA. Certain ores are
subjected to heating in roaster furnaces to alter the compound, to drive off impurities,
and/or to reduce water content. For example, roasting is used to treating sulfide gold
ore, to make it more amenable to leaching. The roasting, with sodium, of certain metals
that form insoluble anionic species (e. g., vanadium) convert the ore values to soluble
sodium salts (e. g., sodium vanadate), which, after cooling, may be leached with water.
Roasters do not use the intense heat of the smelters and refineries and the ores are not
processed ri a molten state with chemical changes occurring. Roasting may, however,
drive off sulfur dioxide or other substances and emissions often have significant
particulate content.
Autoclaving. Autoclaves use pressure and high temperature to prepare some ores for
leaching activities. The autoclave is used to convert the ore to an oxide form which is
more amenable to leaching. The ore is generally in a slurry form in the autoclave.
Leaching Operations. Leaching operations may be categorized both by the type of leachant
used as well as the physical design of the operations.
Physical Design. Several types of leaching "operations are used, typically dependant
on the ore-grade, the leachant, and the target material.
Dump Leaching. Piles of low-grade ore are often placed directly on the ground,
leachant added by a spray or drip system, and leachate containing the
solubilized target metal collected from underneath the dump over a period of
months or years. The dumps are dedicated, that is they are designed to leave
the ore in place after leaching operations are complete. Dump leach operations
designed to recover gold more often are being designed with a plastic liner prior
to placing the ore in order to facilitate recovery of pregnant solution as well as to
minimize release to the environment of the cyanide leachant.
Heap Leaching. In heap leach operations the ore is placed on lined pads in
engineered lifts or piles. The pad may be constructed such that heavy
machinery may be used to off load the leached ore for disposal prior to placing
new ore on the pad but more commonly the heap remains in place when
leaching ends. As with dump leaching the leachant may be applied by spray or
portable drip units; recovery is from-beneath the ore on the impermeable pad
(typically designed with a slight grade and a collection system).
Tank Leaching. In vat or tank leaching the milled ore is placed in a container
equipped for agitation, heating, aeration, pressurization, and/or other means of
facilitating the leaching of the target mineral.
In all three cases a solution management system is required, either in surface
impoundments or tanks. Some operatbns use ponds that were designed with a
compacted earthen liner (e. g. , day), but most copper and all gold operations use
synthetic liners with leachate collection systems. Dumps often have a collection pond
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Chapter 2: Overview of Mining and Mineral Processing Operations 2-11
down-gradient from the dump; heap leach units are more likely to have a system for
collecting solution directly off the pad. Tank and vat leaching operations may be
completely closed systems with no ponds incorporated in the design.
Leachants. Leaching also may be characterized by the type of solution being used to
leach the ore and recover the target metal.
Acid Leaching. Certain target metals are particularly receptive to leaching by
acidic solutions. Copper, for example, is leached by a sulfuric acid solution.
Cyanide Leaching. Sodium cyanide has been used extensively to recover gold
from low-grade ores. Continued improvements in cyanidation technology have
allowed increasingly lower grade gold ores to be mined economically.
Dissolution. Water is used to separate certain water-soluble compounds, such
as sodium, boron, potassium, and certain salts (some that may be formed by
roasting). The compounds are dissolved, purified using basic water chemistry
and filtration, then recrystallized.
Recovery Processes. The values contained in the pregnant leach solutbn are recovered by
one or more of several methods, including the following:
Precipitation. In this process, the metals dissolved in the pregnant leachate are forced
into an insoluble solid form and then filtered or settled out for recovery. Methods to
cause precipitates to form may be chemically-treating, evaporating, and/or changing the
temperature and/or pH.
Electrowinning. The pregnant leachate may be placed in an electrolytic cell and an
electric charge applied. The metal plates out of the solution on the cathode. Insoluble
precipitates may settle out as a material referred to as slimes.
Carbon Adsorption. Activated carbon may be used to adsorb the metal values from
the solution. The carbon is then leached to recover the adsorbed metals.
Cementation. In this method, the metal is "cemented" out of solution by replacement
with less active metal. For example, when a copper leachate solution (CuSO4) is
brought into contact with scrap iron plates, the copper replaces the iron on the scrap
plates and the iron goes into solution (FeSO4). The copper is then removed by washing
the scrap plates.
Solvent Extraction. A chemical-specific solvent may be used to selectively extract a
mineral value dissolved in the pregnant leachate. This is often used in the case of
copper ore leaching; a proprietary organic chemical dispersed in a kerosene dilutent is
used. The copper may then be extracted from the organic base with a strong sulfuric
acid which can be etectrowinned.
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2-12 Chapter 2: Overview of Mining and Mineral Processing Operations
2. 4. 2 Leaching Wastes and Hazardous Materials
Dump and Heap Leach Waste. Following leaching, the large piles of spent ore that remain
are usually left in place. These leach piles vary widely in size, the largest may cover hundreds
of acres, may rise to several hundred feet, and may contain tens of millions of tons of leached
ore. Reusable heap leach pad operations typically have a nearby waste unit for disposal of
spent ore. Alternatively, leached ore from pads may be moved to a dedicated dump for
additional and long term dump leaching. Uncollected leachate from these piles is a potential
source of contamination of ground water, surface water, and soil. In addition, other
contaminants (notably, arsenic, mercury, and selenium, but also including many other heavy
metals) that are present in the spent-ore may appear in leachate over time. Acid drainage may
be generated from the oxidation of sulfide ores and require control. For both dump and heap
leaching, transport by wind-blown dust and/or storm-water erosion may result in physical
contamination off site.
Spent Leachate. When the leach operation is decommissioned or the leachate become
necessary for replacement, the spent leachate becomes a waste requiring appropriate
management. Leachate in the piles may continue to be released after operations cease. For
example, where gold extractbn processes use cyanide to leach the metal from the host rock,
the unpurged or untreated cyanide solution may be washed by rain and snowmelt into streams
or ground water systems if recovery and recycling systems are not working properly.
Electrowinning Slimes and Crud. Slimes and crud result from impurities separated from the
metal value in electrowinning. The slimes that settle put typically are recovered and treated to
recover precious metals, such as gold and silver. Crud results from impurities that foam up in
the electrolytic bath used in electrowinning; these typically are vacuumed from the cells and
returned to the leach operations.
Spent Carbon. Spent carbon is the waste product remaining after the desired metals have
been removed from activated carbon. The activated carbon may contain other metals and
chemicals that were in the ore or used in process, including mercury or cyanide. The spent
carbon is often "reactivated" in the mining process.
2. 5 Mineral Processing
Following beneficiatfon (i.e., leaching or milling) to concentrate the mineral value, the
concentrate typically is processed to further extract and/or refine the metal, thus preparing it for
its final use or for incorporation into physical or chemical manufacturing (as noted previously,
mineral processing is often used within the industry to refer to any post-extraction activities,
including beneficiation; EPA, at least under the RCRA program, excludes beneficiation from
mineral processing). At some bcations, post-mineral processing operations may occur, or
have occurred, as wen (note that under RCRA, EPA delineated a regulatory distinction between
mineral processing and post-mineral processing, although the actual regulatory significance of
this is now minimal). An example of post-mineral processing is the alloying process, in which
various alloys are added to, for example, steel (i.e., a product of mineral processing) to make
alloy steel (which is not a product of mineral processing). While this may not.affect how a site
manager approaches the remediatbn if the operations are co-bcated, it may affect the
understanding of ARARS or what potential impacts from various operations may be expected.
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Chapter 2: Overview of Mining and Mineral Processing Operations 2-13
2. 5. 1 Types of Mineral Processing Operations
There are a variety of mineral processing operations^ including the following major categories:
pyrometallurgical operations (e. g. , smelting, refining, toasting ), hydrometallurgicai operations
(e. g., digestion of phosphate in producing phosphoric acid), and electrometallurgical
operations (e. g., electrolytic refining).
Note that mineral processing may be further categorized as primary or secondary. Broadly
defined, primary mineral processing is focused on processing concentrates from extraction and
beneficiation of raw ores whereas secondary processing focuses on recycling metals or
minerals. Primary mineral processing, such as smelting, may, and often does, incorporate into
its charge mineral processing wastes (e. g., flue dust), scrap, and/or other metals/mineral
bearing materials (e. g., sludge or residues). (Note that under RCRA, EPA requires that
feedstocks be at least 50 percent extraction and beneficiation products to be considered
primary; the significance focuses on certain wastes such as lead smelter slag that are exempt
at primary lead smelters but regulated as potentially hazardous waste at secondary lead
smelters).
Smelting. Smelting is the most common pyrometallurgical process and involves the
application of heat to a charge of ore concentrate and flux in a furnace. Smelting produced
separate molten streams of matte (i.e. , molten product), slag and dross, and dust, an important
by-product. Historically, high-grade ore from the mine may have been smelted directly with no
intermediate concentration.
Roasting. Roasting, a relatively low heat pyrometallurgical process, may be used to prepare
ores, especially sulfide ores, for smelting (note that EPA, under the RCRA program, makes a
distinction between roasting prior to leaching, which is beneficiation, and roasting prior to
smelting, which is mineral processing). Roaster furnaces produce particulate matter referred to
as roaster fines, as well as gaseous emissions such as sulfur dioxide. Where sulfur dioxide is
generated, such as the copper smelting sector, the sulfur elements are now often captured in
acid plants and saleable or useable sulfuricacid generated. In the past, sulfur dioxide
emissions, as well as arsenic and other contaminants, were uncontrolled, and in some cases
contaminated wide areas.
Retorting. In processing metals that are relatively volatile, retort furnaces are employed to
heat the ore concentrate and vaporize the metal (e. g., zinc, mercury, phosphorus). The
vaporized metals are then condensed and recovered. The non-volatilized waste material
remaining in the retort is typically referred to as slag (e. g. , zinc slag, ferrophosphorus).
Fire Refining. Fire refining is a pyrometallurgical process that typically involves heating
smelted material (e. g., blister copper) in a furnace. A flux may be added, and air then blown
through the mixture to oxidize impurities. Most of the remaining sulfur and other impurities
vaporize or convert to slag. Copper is fire refined with the molten copper being poured into
molds to form anodes to be used in electrolytic refining if required. Refining in the lead sector,
referred to as softening, generates slags with antimony, arsenic, tin, and copper oxides.
Dressing. In the lead sector, dressing foibws the initial smelting. In this step, the molten lead
is agitated in a dressing kettle and cooled to just above the freezing point, thereby causing
metal oxides, including lead oxide and copper oxide, to solidify and float to the surface as
dross. The dross, predominantly lead oxide, is treated for metals recovery. Other drossing-
refining steps in the lead sector are decopperizing, where sulfur is added rather than oxygen to
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2-14 Chapter 2: Overview of Mining and Mineral Processing Operations
remove cuprous sulfideas dross, and desilverizing, where zinc is added to alloy insolubly with
precious metals that float up as dross.
Electrolytic Refining. Electrolytic refining, a electrometallurgical process typically applied in
the copper and zinc industry, uses an electric current in an electrolytic bath in which the metal
feed is dissolved. In the copper sector, this may occur following fire-refining by using anodes of
copper that dissolve with the copper reforming on the cathode. Zinc concentrates from
leaching also may be refined electrometal|urgically. The leachate is placed in the electrolytic
cell, a current is applied, and the metal is removed on the cathode. Within the cells, impurities
will either dissolve in the electrolyte but not plate on the cathode or precipitate as a material
referred to in the industry as "slimes". Cathodes are removed and melted in a furnace and the
metal cast 'nto saleable shapes.
Digestion. Digestion is a hydrometallurgical process in which the concentrate is reacted with a
strong liquor (typically hot acid) and the metal value is dissolved. This pregnant liquor is then
processed to purify and precipitate the metal or mineral compound. Impurities maybe left
behind as digester solids or precipitated out separately from the mineral value. Primary
examples of digestion operations are phosphoric acid production (i.e., in which phosphate
concentrate is digested with sulfuric acid to produce phosphoric acid and calcium sulfate
otherwise known as phosphogypsum) or production of titanium tetrachloride.
2. 5. 2 Types of Mineral Processing Wastes and Hazardous Materials
Each of the different types of mineral processing operations generate its own specific waste
streams. Note that certain are large volume wastes, and where considered to be of low hazard,
continue to be excluded from regulation as hazardous under EPA's RCRA program. Many of
the mineral processing wastes that are identified below are or were recycled back to the
mineral processing facilities, since they generally contain high levels of metals. Others were
disposed or dispersed at the mine site and are the focus of remedial concern at many
abandoned or inactive mine sites.
Slag and Dross. Slag and dross are partially fused wastes produced when impurities in
metallic ores or concentrates separate from the molten metal during smelting and fire-refining
processes. Slag contains the gangue minerals, such as waste minerals and non-valuable
minerals, and the flux. In some sectors, the slag is processed to recover some portion that may
be of value. In these cases, the portion not recovered is disposed, typically onsite, or sold for
use as fill or base material where regulations allow. Historically, several sites where slag was
used as road bed material have significantly impacted bcal environments.
Dross is the collection of impurities, typically metal oxides, that float on the molten metal in the
furnace. Often, it consists of materials that can be recovered for their mineral value. Dross
often was either recycled or sent on for further processing. Both dross and slag also have
historically been disposed in waste piles. Current regulation, however, calls for prescribed
landfill disposal if not recycled. ,
Spent Furnace (Refractory) Brick. This material, as its name implies, is from the furnace or
refractory liner and is generated in a relatively small quantity. Smelters within some mineral
processing sectors return this material to the blast furnace to recover any accumulated mineral
value; otherwise, this material is placed in disposal units. At some historical sites these brick
remain, creating needs for remediation.
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Chapter 2: Overview of Mining and Mineral Processing Operations 2-"15
Potliner. Potliner is a specialized form of electrolytic cell liner used in the aluminum production
process. Potliners may contain toxic levels of arsenic gnd selenium, as well as detectable
levels of cadmium, chromium, barium, lead, mercury, |ijyer,,sulfates, and cyanide. While
portions of the potliners currently are novtf recovered aril recycled, much of the material is
managed as a listed hazardous waste.
Roaster Fines. Fine paniculate materials maybe generated by roaster furnace operation.
Currently, these materials are typically recycled to the mineral processing operation as
permitted under RCRA. Historically, however, roaster fines, at least at some sites, went
uncollected and were dispersed downwind; in other cases they were collected and disposed in
waste piles. At least one Superfund National Priority List (NPL) site has identified roaster fine
impacts on the mine site.
Stack Emissions. Emissions from the smelter and refiner furnaces are, under current
regulations, treated to remove regulated materials, including particulates, lead, and sulfur
dioxide. In some historic operations, these stack emissions were released unaltered, resulting
in the dispersal of contaminants to a wide area, especially in the predominant downwind area.
Lead contamination by smelter emission has created significant contamination at several of the
NPL mine sites. Today, the dusts in these emissions are collected to meet an- emission
standards, and the resulting air pollution control dusts are managed appropriately.
Pollution Control Sludges. With the advent of wastewater treatment and air pollution control,
sludges have been generated at most mineral processing operations. In the cases of smelter
operations, these sludges are typically recycled to the smelter to recover mineral value. Where
this is not feasible, the sludge is disposed.onsite.
Slimes from Electrolytic Refining. Slimes result from impurities that settle out of the
electrolytic bath used in electrolytic refining or eiectrowinning. Typically, these are recovered
and treated to recover precious metals, such as gold and silver.
Spent Electrolyte. Spent electrolyte (often called bleed electrolyte when it is removed in small
portions rather than at one time) typically is contaminated by a variety of metals and other
compounds. Today, these electrolytes are typically purified and recycled.
Process Wastewater. Various process wastewaters are and have been generated during
various pyrometallurgical operations. Historically, these have been co-managed with tailings if
the smelter or refinery was co-locatecl. In other cases, discharge to surface waters or surface
impoundments was the preferred approach. Today, these wastes are managed under the
Clean Water Act (i.e., under the NPDES program), RCRA (e. g, surface impoundment
regulation and land application), or the Safe Drinking Water Act (e. g., discharge into injection
wells).
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2-16 Chapter 2: Overview of Mining and Mineral Processing Operations
2.6 Additional Sources of Information
For additional comprehensive references to mineral processing and associated wastes, see the
following EPA documents:
USEPA, OSW. 12-95. Identification and Description of Mineral Processing Sectors and
Waste Streams. WDC; and
USEPA, OSWER. 7-90. Report to Congress on Special Wastes from Mineral
Processing. EPA 530-S W-90-070C. WDC.
USEPA, OSWER. 12-85. Report to Congress on Wastes from the Extraction and
Beneficiation of MetalDc Ores, Phosphate Rock, Asbestos, Overburden from Uranium
Mining, and Oil Shale. EPA 530-SW-85-033.
USEPA, OW. 11-82. Development Document for Effluent Limitations Guidelines and
Standards forthe Ore Mining and Dressing Point Source Category, EPA 440/1-82/061.
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Chapter 3
Environmental Impacts from Mining
3.1 Introduction
This chapter introduces site managers to the types of impacts mining and mineral processing
operations can have on the environment. Knowledge of these impacts wiB be important during
site scoping, characterization, and alternative selection. This background information provides
valuable insight into the contaminants that may be present, potential threats to human health
and the environment, and feasibility of response actions. There are thousands of inactive
and/or abandoned mine sites on federal, state, tribal and private land. While the majority of
these sites are not believed to present significant environmental problems, there are,
nonetheless, many sites that do create significant impacts. In addition to the impacts of
individual mine sites, the cumulative impact of multiple sites within a historic mining district
often has the potential to impair beneficial uses of local surface and groundwater.
Highlight 3-1
Major categories of mining impacts:
Acid Drainage
Metals contamination of
ground/surface water and sediments
Sedimentation
Cyanide
Air emissions and deposition
Physical impacts
A variety of environmental impacts may occur at
an abandoned mine site. Highlight 3.1 lists the
major categories of abandoned mine site impacts.
Leading the list is acid generation, which is one of
the largest problems from hardrock metal mining.
This chapter describes those that are specific to
mine sites. Effects from process or waste
management units common to non-mine sites
(e.g., leaking underground storage tanks, solvent
disposal from mechanical shops) or involving
contaminants found at many sites (e.g., PBCs,
solvents, petroleum, chemicals used in
processing); are not addressed in this reference
document.
The following sections describe each of these environmental impacts characteristic of mine
sites requiring remediation.
3.2 Acid Drainage
The formation of acid drainage and the contaminants associated with it has been described as
the largest environmental problem facing the U.S. mining industry (for additional information
regarding acid drainage refer to Appendix B). Commonly referred to as acid rock drainage
(ARD) or acid mine drainage (AMD), acid drainage may be generated from mine waste rock or
tailings (i.e., ARD) or mine structures, such as pits and underground workings (i.e., AMD). Acid
generation can occur rapidly, or it may take years or decades to appear and reach its full
potential. For that reason, even a long-abandoned site can intensify in regard to its
environmental impacts.
The severity of, and impacts from, AMD/ARD are primarily a function of the mineralogy of the
rock material and the availability of water and oxygen. While acid may be neutralized by the
receiving water, some dissolved metals may remain in solution. Dissolved metals in acid
drainage may include lead, copper, silver, manganese, cadmium, iron, and zinc, among other
metals. Elevated concentrations of these metals in surface water and ground water can
preclude their use as drinking water or aquatic habitat.
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3-2 Chapter 3: Environmental Impacts from Mining
Acid Drainage Generation. Acid is generated at mine sites when metal suifide minerals are
oxidized and sufficient water is present to mobilize the sulfur ion. Metal suifide minerals are
common constituents in the host rock associated with metal mining activity.
Prior to mining, oxidation of these minerals and the formation of sulfuric acid is a function of
natural weathering processes. The oxidation of undisturbed orebodies followed by the release
of acid and mobilization of metals is slow. Natural discharge from such deposits poses little
threat to receiving aquatic ecosystems except in rare instances. Mining and beneficiation
operations greatly increase the rate of these same chemical reactions by removing large
volumes of suifide rock material and exposing increased surface area to air and water.
Materials/wastes that have the potential to generate ARD as a result of metal mining activity
include mined material, such as spent .ore from heap and dump leach operations, taflings, and
waste rock units, as well as overburden material. AMD generation in the mines themselves
occurs at the pit walls in the case of surface mining operations and in the underground
workings associated with underground mines.
The potential for a mine or its associated waste to generate acid and release contaminants
depends on many factors and is site-specific. These site-specific factors can be categorized as
generation factors, control factors, and physical factors.
Generation Factors. Generation factors determine the abifity of the material to produce acid
Water and oxygen are necessary to generate acid drainage; certain bacteria enhance acid
generation. Water serves as a reactant, a medium for bacteria, and the transport medium for
the oxidation products. A ready supply of atmospheric oxygen is required to drive the oxidation
reaction. Oxygen is particularly important in maintaining the rapid oxidation catalyzed by
bacteria at pH values below 3.5. Oxidation pf sulfides is significantly reduced when the
concentration of oxygen in the pore spaces of mining waste units is less than 1 or 2 percent.
Different bacteria are better suited to different pH (eve)s and physical factors (discussed below).
The type of bacteria and population sizes change as growth conditions are optimized.
Chemical Control Factors. Chemical control factors determine the products of oxidation
reaction. These factors include the ability of the generation rock or receiving water to either
neutralize the acid (i.e., positive effect) or to change the effluent character by adding metals
ions mobiized by residual acid (i.e., negative effect). Neutralization of acid by the alkalinity
released when acid reacts with carbonate minerals is an important means of moderating acid
production and can serve to delay the onset of acid production for long periods or even
indefinitely. The most common neutralizing minerals are calcite and dolomite. Products from
the oxidation reaction, such as hydrogen ions and metal ions, may also react with other non-
neutralizing constituents. Possible reactions include ion exchange on clay particles, gypsum
precipitation, and dissolution of other minerals. The dissolution of other minerals contributes to
the contaminant load in the acid drainage. Examples of metals occurring in the dissolved form
include aluminum, manganese, copper, lead, zinc, and others.
Physical Factors. Physical factors include the physical characteristics of the waste or
structure, the way in which acid-generating and acid-neutralizing materials are placed, and the
local hydrology. The physical nature of the material, such as particle size, permeability, and
physical weathering characteristics, is important to the acid generation potential. Though
difficult to weigh, each of these factors influences the potential for acid generation and is,
therefore, an important consideration for long term waste management. Particle size is a
fundamental concern because it affects the surface area exposed to weathering and oxidation.
Surface area is inversely proportional to particle size. Very coarse grain material, as is found in
waste rock dumps, exposes less surface area but may allow air and water to penetrate deeper
into the unit, thereby exposing more material to oxidation and ultimately producing more acid.
Air circulation in coarse material is aided by wind, changes in barometric pressure, and possibly
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Chapter 3: Environmental Impacts from Mining 3-3
convective gas flow caused by heat generated by the oxidation reaction. In contrast, fine-grain
material (e.g., tailings) may retard air and very fine material may limit water flow; however, finer
grains expose more surface area to oxidation. d"he relationships among particle size, surface
area, and oxidation play a prominent role! in a'biB pfedftjSri methods and in mining waste
management units. As waste material weathers with time, particle size is reduced, exposing
more surface area and changing physical characteristics of the waste unit. However, this will
be a slower process
A number of studies and publications address
acid drainage. Historically, acid generation
remediation efforts have centered around
acid drainage from coal mines and their
associated spoils. Increasingly, acid
generation is being managed at hardrock
mines. Active treatment (e.g., lime treatment
and settling) has been successfully used and
passive treatment (e.g., anoxic limestone
drains) have been tried with some limited
success and constant improvement.
Highlight 3-2
Eagle Mine
Zinc and other base and precious metals were
produced from ores excavated from the underground
mine in central Colorado from 1878 to 1977. The
resultant wastes consist of roaster piles, tailings
ponds, waste rock piles and acid drainage from the
mine. Percolation from the tailings ponds has
contaminated ground water below and down gradient
of the ponds. The ground water discharges to a
nearby stream. Runoff from the roaster, waste piles
and acid drainage from the mine also discharge
directly to the stream. The main parameters of
concern are pH, arsenic, cadmium, copper, lead,
manganese, nickel, and zinc. In particular,
concentrations of cadmium, copper, and anc exceed
water quality criteria in the stream. In addition, levels
of dissolved solids are also above background
concentrations. At least two private wells previously
used for drinking water haws been contaminated.
The site is currently on the National Priorities List
and various remedial actions have taken place.
3.3 Metal Contamination of Ground
and Surface Water, and Associated
Sediments
Mining operations can affect ground water
quality in several ways. The most obvious
occurs in mining below the water table, either
in underground workings or open pits. This
provides a direct conduit to aquifers. Ground
water quality is also affected when waters
(natural or process waters or wastewaters) infiltrate through surface materials (including
overlying wastes or other material) into ground water. Contamination can also occur when
there is an hydraulic connection between surface and ground water. Any of these can cause
elevated pollutant levels in ground water. Further, disturbance in the ground water flow regime
may affect the quantities of water available for other local uses. In addition, contaminated
ground water may discharge to surface water down gradient of the mine, as contributions to
base flow in a stream channel or springs.
Dissolved pollutants at a mine site are primarily metals but may include sulfates, nitrates, and
radionuciides; these contaminants, once dissolved, can migrate from mining operations to local
ground and surface water (contamination of surface water may also occur as contaminated soil
or waste materials are eroded and washed into water bodies). These are discussed in section
3.4.). Dissolved metals may include lead, copper, silver, manganese, cadmium, iron, arsenic,
and zinc. Elevated concentrations of these metals in surface water and ground water may
preclude their use as drinking water. Low pH levels and high metal concentrations can have
acute and chronic effects on aquatic life/biota. While AMD/ARD can enhance contaminant
mobility by promoting leaching from exposed wastes and mine structures, releases can also
occur under neutral pH conditions.
Dissolution of metals due to low pH is a well known characteristic of each acid drainage. Low
pH is not necessary for metals to be mobilized and to contaminate waters; there is increasing
co'ncern about neutral and high pH mobilization.
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3-4 Chapter 3: Environmental impacts from Mining
Sources. Primary sources of dissolved pollutants from metal mining operations include
underground and surface mine workings,
i overburden and waste rock piles, tailings piles
and impoundments, direct discharges from
conventional milling/beneficiation operations,
leach piles and processing facilities, chemical
storage areas (runoff and spills), and
reclamation activities. Discharges of process
water, mine water, storm and snowmelt
runoff, and seepage are the primary transport
mechanisms to surface water and ground
water.
Highlight 3-3
California Gulch
The California Gulch Superfund site, located in the
upper Arkansas River Valley in Lake County,
Colorado, is an example of a site severely affected by
metal contamination. The study area for the remedial
action encompasses approximately 15 square miles
and includes California Gulch, a tributary of the
Arkansas River, and the City of Leadville. Mining for
lead, zinc, and gold has occurred in the area since
the late 1800's. The site was added to the National
Priority List (NPL) in 1983. A remedial investigation
(Rl) conducted by EPA in 1984 indicated that the
area is contaminated with metals, including cadmium,
copper, lead, and zinc migrating from numerous
abandoned and active mining operatbns. A primary
source of the metals contamination in the Arkansas
River is via the California Gulch. The Yak Tunnel,
built to drain the local mine workings, drains into the
California Gulch. Acid generated in the mine
dissolves and mobilizes cadmium, copper, iron, lead,
manganese, zinc, and other metals. The tunnel and
its laterals and drifts collect this metal-laden acidic
water and discharge it into California Gulch, the
Arkansas River, and the associated shallow alluvial
ground-water and sediment systems. From previous
investigations and sampling data, itwas concluded
that, as of the early 1980fe, the Yak Tunnel
discharged a combined total of 210 tons per year of
cadmium, lead, copper, manganese, iron, and zinc
into California Gulch. Starting in 1990, one of the
PRPs consented to build and operate a treatment
plant for the Yak Tunnel discharge. The treatment
plant operates continuously and has significantly
improved water quality of the Arkansas River, into
which it discharges.
Naturally occurring substances in the site
area are the major source of these pollutants.
Mined ore not only contains the metal being
extracted but varying concentrations of a wide
range of other metals (frequently, other
metals may be present at much higher
concentratbns and can be significantly more
mobile than the target mineral). Depending
on the local geology, the ore (and the
surrounding waste rock and overburden) can
include trace levels of aluminum, arsenic,
asbestos, cadmium, chromium, copper, iron,
lead, manganese, mercury, nickel, silver,
selenium, and zinc.
Chemicals used in mining and beneficiation
are also a potential source of water
contamination. Common types of reagents
include copper, zinc, chromium, cyanide,
nitrate and phenolic compounds, and sulfuric
acid at copper leaching operations. With the
exception of leaching operations and possibly
the extensive use of nitrate compounds in blasting and reclamation, the quantities of reagents
used are relatively small compared to the volumes of water generated. As a result, the risks
from releases of toxic pollutant from reagents not related to leaching are generally limited.
Sediment Contamination. Mining processes can result in the contamination of associated
sediments in receivhg streams when dissolved pollutants discharged to surface waters partition
to sediments in the stream. In addition, fine grained waste materials eroded from mine sites
can become sediments, as described in Section 3.4 below. Specifically, some toxic
constituents (e.g., lead and mercury) associated with discharges from mining operations may
be found at elevated levels in sediments, while not being detected in the water column or being
detected at much lower concentratbns. Sediment contamination may affect human health
through the consumption of fish and other biota that bioaccumulate toxic pollutants. Elevated
levels of toxic pollutants in sediments also can have direct acute and chronic impacts on
macroinvertebrates and other benthic organisms. Finally, sediment contamination provides a
long-term source of pollutants through potential re-dissolution in the water column. This can
lead to chronic contamination of water and aquatic organisms. Currently, no national sediment
standards/criteria have been established for toxic pollutants associated with mining operations.
An ecological risk assessment may be an appropriate tool to evaluate sediment impacts.
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Chapter 3: Environmental Impacts from Mining 3-5
3.4 Sedimentation of Surface Waters t
/: '.> ~fi?.t • -
Because of the large land area disturbed by mining operations and the large quantities of
earthen materials exposed at sites, erosion is a primary concern at mine sites. Erosion may
cause significant loading of sediments and any entrained chemical pollutants to nearby
streams, especially during severe storm events and high snowmelt periods. Historic mining and
mineral processing sites may have discharged wastes directly into surface waters. This has
been particularly the case with tailings, that historically in many areas were deposited directly
into surface waters or placed at the edge of surface waters where erosions would transport the
tailings to the surface waters.
Erosion. Water erosion may be described as the process by which soil particles are detached,
suspended, and transported from their original location. Sedimentation is the byproduct of
erosion, whereby eroded particles are deposited at a different location from their origin.
The factors influencing erosion and sedimentation are interrelated and all relate to either the
impact of precipitation or runoff velocity and volume. Sedimentation is considered the final
stage in the erosion process; thus, the mechanisms affecting erosion also affect sedimentatbn.
The main factors influencing erosion include rainfall/snowmelt runoff, soil infiltration rate, soil
texture and structure, vegetative cover, slope length, and implementation of erosion control
practices.
Sources of Loading. Major sources of
erosion/sediment loadings at mining sites
include open pit areas, heap and dump leach
operations, waste rock and overburden piles,
tailings piles, haul and access roads, ore
stockpiles, exploration areas, and
reclamation areas. The variability in natural
site conditions (e.g., geology, vegetation,
topography, climate, and proximity to and
characteristics of surface waters) combined
with significant differences in the quantities
and characteristics of exposed materials at
mines preclude any generalization of the
quantities and characteristics of sediment
loadings. New sources are frequently
located in areas with other active operations,
as well as historic abandoned mines. Other
non-mining sources also may contribute to
erosion impacts in the watershed. At
smelter sites historic air emissions may have
caused toxicity to focal vegetation,
increasing erosion potential in impacted
areas.
Environmental Impacts. Particulate matter
is detrimental to local fish populations.
Decreased densities of macroinvertebrate
and benthic invertebrate populations have _^____
been associated with increased suspended
solids. Enhanced sedimentation within
aquatic environments also has the effect of inhibiting spawning and the development offish
Highlight 3-4
Mineral Creek and Pinto Creek
The impacts of mines on aquatic resources have
been well documented. For example, a Mineral
Creek fisheries and habitat survey conducted by the
Arizona Game and Fish and the U.S. Fish & Wildlife
Service showed that significant damage was caused
by an active mining activity on the shores of Mineral
Creek. In summary, the upstream control station
showed an overhead cover (undercut bank,
vegetation, logs, etc.) of 50% to 75%. The dominant
substrate was small gravel, and in stream cover
consisted of aquatic vegetation. Rve species offish
were captured for a total of 309 individual fish. In
contrast, the downstream station showed an
overhead cover of less than 25%. The dominant
substrate was small boulders, and in stream cover
consisted of only interstitial spaces and very little
aquatic vegetation. No species offish were captured
and very few aquatic insects were observed or
captured. This Mineral Creek survey shows a
significant degradation of habitat quality below the
mine. Pinto Creek, which received a massive
discharge of tailings and pregnant leach solution from
an active copper mine, was also surveyed. The
tailings had a smothering, scouring effect on the
stream. Pinto Creek is gradually recovering from this
devastating discharge through the import of native
species from unaffected tributaries. However, the
gene pool of the native fish is severely limited as only
one age group of fish has repopulated Pinto Creek. A
second unauthorized discharge of pollutants to the
creek could eliminate that fish species.
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3-6 Chapter 3: Environmental Impacts from Mining
eggs and larvae, as well as smothering benthic fauna. In addition, high turbidity may impair the
passage of light, which is necessary for photosynthetfc activity of aquatic plants.
Contaminated Sediments. Exposed materials from min'mg operations, such as mine
workings, wastes, and contaminated soils, may contribute sediments with chemical pollutants,
including heavy metals. Contaminated sediments in surface water may pose risks to human
health and the environment as a persistent source of chemicals to human and aquatic life and
those non-aquatic life that consume aquatic life. Human exposure occurs through experiencing
direct contact, eating fish/shellfish that have bioaccumulated toxic chemicals, or drinking water
exposed to contaminated sediments. Continued bioaccumulation of toxic pollutants in aquatic
species may limit their use for human consumption. Accumulation in aquatic organisms,
particularly benthic species, can also cause acute and chronic toxicity to aquatic life. Finally,
organic-laden solids have the effect of reducing dissolved oxygen concentration, thus creating
toxic conditions.
Physical Impacts. Beyond the potential for pollutant impacts on human and aquatic life,
physical impacts are associated with the sedimentation, including the filling of deep pools
resulting in the loss of habitat for fish and an increase in temperature. The sedimentation can
also result in the filing of downstream reservoirs reducing the capacity for both flood control
and power generation. The sedimentation can also cause the channel to widen and become
shallower, which may increase the frequency of overbank flow.
3.5 Cyanide
The use of cyanide has a bng history in the
mining industry. For decades, it has been
used as a pyrite depressant in base metal
flotation, a type of beneficiatbn process (see
Section 2.3). It also has been used for more
than a century in gold recovery (see Section
2.4). In the 1950's, technology advances
that allowed large-scale beneficiation of gold
ores using.cyanide (first demonstrated in
Cripple Creek, Colorado) set the stage for
the enormous increase in cyanide usage
when gold prices skyrocketed in the late 1970's and 1980's. Continued improvements in
cyanidation technology have allowed increasingly lower grade gold ores to be mined
economically using leach operations. The use of cyanide in the leaching of gold ores has an
increased potential to impact the environment because of the greater quantity that is used in
leachkig.
Highlight 3-5
The Summitville Mine
The Summitviile Mine is an open-pit, heap-leach gold
mine using cyanide beneficiation. The mine operated
until 1992 when it was shut down by the company h
part due to continued releases of cyanide to the
environment The largest release, caused by pump
failures resulted in a cyanide laden contaminant
plume that killed fish for a distance of 17 miles in the
Alamosa River.
The acute toxicity of cyanide (inhalation or
ingestion of cyanide interferes with an
organism's oxygen metabolism and is lethal)
coupled with impacts from a number of major
incidents have focused attention on the use
of cyanide in the mining industry. Through
the 1980's, as cyanidation operations and
cyanide usage proliferated, incidents were
reported in which waterfowl died when using
tailings ponds or other cyanide-containing
solution ponds. In addition, a number of
major spills occurred, including one in South
Highlight 3-6
Romanian Cyanide Spill
On January 31, 2000, a tailings dam failed at the
Aurul gold mine near the town of Bai Mare in
Romania. The failure released approximately 3.5
million cubic feet of water contaminated with cyanide
and heavy metals into the the Szamos and Tizsa
Rivers in Romania, Hungary, and Yugoslavia,
approximately 800kms of ri\«r, before flowing into the
Danube, impacting approximately 1200 km of river.
The total fish kill was estimated at over 1000 metric
tons offish.
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Chapter 3: Environmental Impacts from Mining 3-7
Carolina in 1990, when a dam failure resulted in the release of more than 10 mfllion gallons of
cyanide solution, causing fish kills for nearly 50 miles downstream of the operation. Regulatory
authorities have responded by developing increasingly stringent regulations or non-mandatory
guidelines which address the design of facilities that use cyanide (e.g., liners), operational
concerns (e.g., monitoring, treatment), or closure/reclamation requirements.
Environmental Impacts. Cyanide can cause three major types of potential environmental
impacts.
Free-standing Cyanide Solution. Cyanide-containing ponds and ditches can present
an acute hazard to wildlife and birds. Taiings pbnds may present similar hazards,
although cyanide concentrations are typically much lower. Rarely in the case of
abandoned mines should acute cyanide toxicity be of concern.
Release (i.e., spills) of Cyanide Solution. Spills can result in cyanide reaching
surface water or ground water and causing short-term (e.g., fish kills) or long-term (e.g.,
contamination of drinking water) impacts. Again, because cyanide solution is not
typically present at abandoned mine sites HI quantities large enough to release as a
spill, this type of impact is unlikely at abandoned mine sites.
Cyanide Leachate from Process or Waste units. Cyanide in active heaps and ponds
and in mining wastes (e.g., heaps and dumps of spent ore, tailings impoundments) may
be released and present hazards to surface water or ground water. In all but a few
major cases, cyanide spills have been contahed onsite, and soils have provided
significant attenuation in most cases. Cyanide may also increase the potential for
metals to go into solution and, therefore, be transported to other locations. •
In general, cyanide is not considered a significant environmental impact concern over the long
term for inactive or abandoned mines. If detoxification and reclamation are effectively
performed, most residual cyanide in closed heaps and impoundments will be strongly
complexed with iron. Although the stability of such complexes over long periods is not well
understood, cyanide is generally considered to be much less of a long-term problem than acid
generation, metals mobility, and other types of environmental impacts.
Types of Cyanide. Some basic knowledge of the different forms of cyanide is necessary to
understand regulatory standards and remediation activities. Cyanide concentrations are
generally measured as one of the following four forms:
Free Cyanide. Free cyanide refers to the cyanide that is present in solution as CN or
HCN and includes cyanide-bonded sodium, potassium, calcium, or magnesium (free
cyanide is very difficult to measure except at high concentrations and its results are
often unreliable, difficult to duplicate, or inaccurate).
Weak Acid Dissociable (WAD) Cyanide. WAD cyanide is the fraction of cyanide that
will volatilize to HCN in a weak acid solution at a pH of 4.5. WAD cyanide includes free
cyanide, simple cyanide, and weak cyanide complexes of zinc, cadmium, sHver, copper,
and nickel.
Total Cyanide. Total cyanide refers to all of the cyanide present in any form, including
iron, cobalt, and gold complexes.
Cyanide Amenable to Chlorination (CATC). CATC cyanide refers to the cyanide that
is destroyed by chforination. CATC is commonly used at water treatment plants.
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3-8 Chapter 3: Environmental Impacts from Mining
Free cyanide is extremely toxic to most organisms, and this form has been most frequently
regulated (i.e., EPA established a maximum contaminant level [MCL] under the Safe Drinking
Water Act and recommended an ambient water quality criterion for protection of freshwater
aquatic life under the Clean Water Act). Mining-related standards and guidelines developed
more recently by states often specify WAD cyanide, largely because of the difficulty in
measuring free cyanide at the low concentrations of regulatory concern. Longer term
environmental concerns with cyanide, those not related to acute hazards from spills, revolve
around the dissociation into toxic free cyanide of complexed cyanides in waste units and the
environment. Unsaturated soils provide significant attenuation capacity for cyanide. Within a
short time and distance, for example, free cyanide can volatilize to HCN if solutions are buffered
by the soil to a pH roughly below 8. Adsorption, precipitation, oxidation to cyanate, and
biodegradation can also attenuate free cyanide in soils under appropriate conditions. WAD
cyanide behavior is similar to that of free, although WAD cyanide also can react with other
metals in soils to form
insoluble salts.
Highlight 3-7
The Bunker Hill Area
The Bunker Hill Mining and Metallurgical Complex Superfund site is an
example of a mining site affected by airborne pollutants. The complex
includes the Bunker Hill Mine (lead and zinc), a milling and
concentration operation, a lead smelter, a silver refinery, an electrolytic
zinc plant, a phosphoric acid and phosphate fertilizer plant, sulfuric acid
plants, and a cadmium plant. EPA has since demolished and capped
the smelter complex. The major environmental problems at the Site
were caused by smelter operations and mining and milling. The smelter
discharged heavy metal particulates and gases, particularly sulphur
dioxide, to the atmosphere. Prior to the I970's, recovery of heavy metal
particulates, such as zinc and lead, was not required from smelter
stacks. Instead, tons of metal particulates were emitted directly from the
stack into the atmosphere. The lead and zinc plant stacks historically
used baghouses and electrostatic precipators to capture particulates for
recovery of valuable metals. Because of a fire and subsequent
problems with the baghouses, the plant continued to emit these
particulates during the early-to-mid 1970's. Significant ecological
damage has occurred in the areas surrounding the site. Soils near the
.smelting complex have been sevsrely impacted by years of sulfur
dioxide impact and metals deposition. The hillsides around the smelter
complex were denuded of vegetation due, in part, to the smelter and
mining activity. In response, 3,200 acres of hillside have been
replanted since 1990.
3.6 Air Emission and
Downwind Deposition
Particulate material (PM) and
gaseous emissions are
emitted during mining,
beneficiation, and mineral
processing (refer to Chapter 2
for details about mining
processes and associated
waste). Gaseous emissions
are generated by process
operations, primarily those
using heat to treat or convert
ores or concentrates (e.g.,
roasting or smelting).
Generally, particulate
releases are flue dusts (e.g.
from sinter, roaster, smelter,
or refinery stacks) or fugitive
dust (e.g. from crushers,
tailings ponds, road use).
The remediation of impacts caused by gaseous and particuiate emissions from process units
typically focuses on contaminated soils associated with downwind deposition. At abandoned
mine sites, the processes that were the source of the emissions typically have either ceased
operation or installed air pollution controls, therefore continued deposition is unlikely. Fugitive
dust may still, however, be emitted from unstabilized waste management units and
contaminated sites or from transportation and remediation activities.
Gaseous Emissions. Pyrometallurgical processes often generate gaseous emissions that are
controlled to some extent under current regulatbns. In the past, these gaseous releases were
typically not weB controlled, and the emissions were blown downwind in the release plume.
Some gaseous emissions, such as sulfur dioxide, affect the downwind environments through
acid precipitation or dry deposition. Metals such as zinc, arsenic, mercury and cadmium are
metals that wil vaporize when heated in a pyrometallurgical process unit. In retort processing,
these metals are captured as gas, then condensed, and the metal processed for use. In the
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Chapter 3: Environmental Impacts from Mining 3-9
absence of capture and condensation, the gaseous metals are released and condensed
downwind from the release plume. Zinc released historically from smelters has had significant
impacts on downwind biota as it is phytotoxic at high concentratbns. Arsenic also has
significant impacts downwind, primarily^onjfaunal receptor^)
Particulate Emissions. In the past, emissions from process operations, such as smelting and
roasting, were not wel controlled and, together with tailings deposition, caused some of the
most widespread contamination. Metal smelting, in the absence of adequate air pollution
controls emitted particulates high in lead and other metal contaminants from smoke stacks that
would then settle out of the air stream. Although deposition at any distance may have been at a
relatively low concentration (particularly as stacks became higher), the tang period of deposition
(i e., from decades in some cases to over a century in others) and the biostabihty of metals
have created soil contamination problems of significant proportions. With the advent of air
pollution regulations and subsequent air pollution controls (ARC), smelter flue residues were
deposited onsite in waste piles or landfills. These wastes often have high metal concentrations,
high enough that, when technically feasible, the dusts may be returned to the smelter to recover
the metal value.
Fugitive Dust Fugitive dust is produced from mining operations (e.g., blasting), transportation
(e g loading equipment, haul vehicles, conveyors), comminution (e.g., crushing and grinding),
and waste management operations (i.e., waste rock dumping). Wind also entrains dust from
dumps and spoil piles, roads, tailings, and other disturbed areas. Dust problems from tailings,
in particular, may not appear until after closure/abandonment, when the waste material dries
out Only then may high levels of metals (arsenic, for example) trigger concerns. Tailings and
waste rock at metal mines usually contain trace concentrations of heavy metals that may be
released as fugitive dust to contaminate areas downwind as coarse particles settle out of
suspension in the air. Stabilization and reclamation efforts are aimed in part at reducing fugitive
dust emissions; remediation often must address the downwind soil contamination.
3.7 Physical Impacts from Mine and Waste Management Units
Mine structures and waste management units pose a unique set of problems for a site manager
in planning and conducting remediations at mine sites. Structural problems with the waste units
and the mines must be considered from a perspective of both ensuring the safety of
remediation workers and alleviating environmental impacts that would result from structural
failure and a subsequent release of contaminants.
Slope Failure. Slopes at mine sites fall into two categories: cut slopes and manufactured or
filled slopes. The methods of slope formation reflect the hazards associated with each. Cut
slopes are created by the removal of overburden and/or ore which results in the creation of or
alteration to the surface slope of undisturbed native materials. Changes to an existing slope
may create environmental problems associated with increased erosion, rapid runoff, changes in
wildlife patterns and the exposure of potentially reactive natural materials. Dumping or piling of
overburden tailings, waste rock or other materials creates manufactured or filled sbpes.
These materials can be toxic, acid forming, or reactive. Slope failure can result in direct release
or direct exposure of these materials to the surrounding environment. Saturation of waste
material can also trigger slope failure.
Structural Stability of Tailings Impoundments. The most common method of tailings
disposal is placement of tailings slurry in impoundments formed behind raised embankments.
Modern tailings impoundments are engineered structures that serve the dual functions of
permanent disposal of the tailings and conservation of water for use in the mine and mill.
Today, many tailings impoundments are lined to prevent seepage, this is rarely the case at
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3-10 Chapter3: Environmental Impacts from Mining
historic mine sites. In addition, modern tailings impoundments are designed to accommodate
earthquake acceleration.
The historic disposal of talings behind earthen dams and embankments raises a number of
concerns related to the stability of the units. In particular, tailings impoundments are nearly
always accompanied by unavoidable and often necessary seepage of mill effluent through or
beneath the dam structure. Such seepage results from the uncontrolled percolation of stored
water or precipitation downward through foundation materials or through the embankment.
Failure to maintain hydrostatic pressure within and behind the embankment below critical levels
may result in partial or complete failure of the structure, causing releases of tailings and
contained mill effluent to surrounding areas. Since most modern mines recycle waste from
impoundments back to the process, the cessation of this recycling at the closure/abandonment
has to be accompanied by other means to maintain safe levels of hydrostatic pressure.
Structural stability depends on the physical characteristics of the waste material (e.g., percent
slimes vs. sands in impoundments), the physical configuration of the waste unit, and site
conditions (e.g., timing and nature of precipitation, upstream/uphill area that will provide
inflows). .
Subsidence. Mining subsidence is the movement of the surface resulting from the collapse of
overlying strata into mine voids. The potential for subsidence exists for all forms of
underground mining. Subsidence may manifest itself in the form of sinkholes or troughs.
Sinkholes are usually associated with the collapse of a portion of a mine void (such as a room
in room and pillar mining); the extent of the surface disturbance is usually limited in size.
Troughs are formed from the subsidence of large portions of the underground void and typically
occur over areas where most of the resource has been removed.
Effects of subsidence may or may not be visible from the ground surface. Sinkholes or
depressions in the landscape interrupt surface water drainage patterns; ponds and streams
may be drained or channels may be redirected. Farmland can be affected to the point that
equipment cannot conduct surface preparation activities; irrigation systems and drainage tiles
may be disrupted. In developed areas, subsidence has the potential to affect building
foundations and walls, highways, and pipelines. However, metal mines are often located in
remote areas where there is a lack of development, minimizing this risk. Subsidence can
contribute to increased infiltration to underground mines, potentially resulting in increased AMD
generatbn and a need for greater water treatment capacity in instances where mine drainage
must be treated. Ground water flow may be interrupted as impermeable strata break down and
could result in flooding of the mine voids. Impacts to ground water include changes in water
quality and flow patterns (including surface water recharge).
Structures. Structures at mining and mineral processing sites can be a physipal hazard for
investigative and remediation workers and contain quantities of contaminates. For example,
buildings at many mining and mineral processing sites were just shut down when the facility
stopped production with the hope that production would be restarted. Because of this many
buildings may contain both chemicals used in the process in containers that are no longer intact
or quantities of material, such as flue dust or feed product that contain high concentrations of
contaminates. In addition to the materials contained in the structure, the structure may be
unsafe due to time, weather, and the exposures that occurred during operations, such as the
heat of a smelting operations or acid spills from an acid plant.
Mine Openings. Mine openings, both horizontal and vertical, can be a significant physical
hazard at an abandoned mine site. In many cases the openings are well known and are a
threat to the general populatbn, since the adventurous want to enter them and explore. These
mine openings may harbor an number of physical hazards that can injure or kill those who
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Chapter 3: Environmental Impacts from Mining 3-11
enter, including unstable ground that could collapse or bad air, either insufficient oxygen or
containing poisonous gases, such as carbon monoxide. The other physical hazard from mine
openings are those that are unknown, particularly vertical shafts. If the opening has been
covered, either by an old collapsed building |>r vegetation, they may pose the threat of falfing,
sometimes hundreds of feet, to individuals of wildfife wlio may get to close to the obscured
opening.
3.8 Sources of Additional Information
To more fully understand the broad environmental impacts found at mining and mineral
processing sites that are on the NPL see Appendix C - Mining Sites on the NPL. Appendix B
provides further discussion of acid rock discharge (ARD) and acid mine discharge (AMD)
including an annotated bibliography.
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3-12 Chapter 3: Environmental Impacts from Mining
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Chapter 4
Setting Goals and Measuring Success
4.1 Introduction
This chapter outlines considerations in setting goals for mine site cleanup and in assessing the
success of mine site cleanup initiatives. It covers the coordination between federal and date
agencies in determining the goals that need to be met and resolving conflicts between different
goals in different agencies. The chapter further discusses how a site manager can measure
the success of meeting the goals that were set for the site.
4.2 National and Regional Goals.
Mining activities have been an integral part of the economy and culture of our nation since the
mid-1800's Mining and mineral beneficiation operations continue today at numerous locations,
largely under the auspices and environmental control of State regulatory agenoes and the
purview of federal land managing agencies (EPA National Hardrock Mining Framework, 1997).
The largest mining-associated environmental response task faced by governmental agencies
today involves the tens of thousands of abandoned mine sites which stem from the»|ntense
mining and industrial development activities that occurred largely between the 1860 s and post-
World War II Since the early 1970's a broad mix of EPA, state and federal natural resource
and land managing agencies have been involved in addressing threats to human health and the
environment at a variety of sites where hardrock mining, milling and smelting activities have
occurred.
Under the auspices of the Superfund program, states and EPA began to address a number of
the largest and most environmentally serious sites (e.g., Bunker Hill, ID; Butte-Silver Bow
Creek MT- California Gufch-Leadville, CO; Iron Mountain, CA). Many of these sites were
slated'for cleanup because the presence of toxic levels of heavy-metal res.dues generated by
mining and industrial operations were a health threat, not only to significant population centers,
but were also severely impacting the surrounding watersheds and drainages where cold-water
fishery resources are highly valued aspects of recreation and tourism.
In addition to the NPL-site activities over the past one and a half decades, site assessment and
inventorying efforts by states, federal land managing agencies and the EPA continue to identify
abandoned mine sites and features consisting of smaller smelter and milling operations,
draining mine adits, impounded and alluvial tailings, waste rock piles, and related contaminated
stream reaches. Comprehensive information has not yet been compiled to completely
ascertain the nature and extent of the environmental problems posed by abandoned mine sites,
but information is being assembled and reviewed by involved agencies and impact indicators
are emerging. Historical databases such as the Minerals Availability System and Mining
Industry Locator System compiled by the former U.S. Bureau of Mines, now ma.ntaned by the
U S Geological Survey, as well as water quality assessment reports conducted by states under
the Clean Water Act indicate the presence of more than 200,000 abandoned mine sites located
within hundreds of watersheds affecting hundreds of miles of streams and fisheries throughout
the western U S. While comprehensive qualitative and quantitative abandoned mine sites site
data and impact information is not yet available, experienced professionals estimate, based on
inventory efforts, remediation studies, cleanup activities and experience to date, that less than
ten percent (10%) of the sites that were actively mined are expected to cause significant
adverse impacts to riparian zones and aquatic habitats of receiving streams. Determining
which sites are the significant sources of metal-leachates and understanding the range of
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4-2 Chapter 4: Setting Goals and Measuring Success
impacts, as well as judging the relative priority, need and basis for response activity, will be an
important aspect of goal-setting for abandoned mine site work at state and local levels.
Under a variety of land management and environmental protection statutes at the federal level,
the U.S. Department of the Interior (through the Bureau of Land Management, the Bureau of
Indian Affairs, the Fish and Wildlife Service, and the Geological Survey), the U.S. Department
of Agriculture (through the Forest Service, and the Natural Resource Conservation Service), the
Environmental Protection Agency, and the U.S. Army Corps of Engineers have significant
responsibilities in coordinating and implementing the activities necessary to accomplish
environmental response to the abandoned mine site problem across the country. States also
play a major role in managing releases from abandoned mine sites through implementation of
federally delegated programs or specific state authorities. The programs and budgets these
federal agencies bring to bear on the abandoned mine site activities will largely occur through
the regional, state and local offices and staffs of the agencies. This will enable and assure that
as environmental response planning and remediation projects occur, they are done in close
collaboration with state and local governments, and meet the goals and needs of the states and
local areas.
4.3 State and Local Goals
While the Environmental Protection Agency, the Department of Interior, and the Department of
Agriculture work to coordinate their respective efforts, dialogue with state natural resource
agencies and local governments needs to be constantly focused on projects which provide the
earliest and most tangible environmental benefits to ecosystems and communities. Under the
auspices of EPA's National Hardrock Mining Framework policies, EPA regional offices will be
participating in discussions between federal, state and local governments to understand the
needs, priorities and objectives of abandoned mine sites activities within states and at particular
localities and watersheds. These discussions will focus attention on short-term and long-term
needs for addressing humart-health and ecosystem issues, including adverse impacts to:
• Homesite and municipal water supplies,
Aquatic resources and improvements,
Recreational uses and approvements,
• Agricultural water users,
Industrial water users,
Residences,
• Workers, and
Wildlife.
4.3.1 Human Health Impacts
Completion of the current NPL-listed sites will have addressed the most serious human health
threats at population centers. However, rising populations and urbanization (both residential
and commercial) underway throughout the western U.S. brings new concerns about mine waste
exposures to new residents, workers, and recreational users as land redevelopment occurs.
States and bcal governments are becoming increasingly concerned about human health
impacts derived from locally-impacted headwater aquifers which are being utilized as well-water
sources for mountain homesites, metal-contaminated surface waters which serve as municipal
water supplies for larger population centers, new development of commercial/industrial sites, as
well as the increased frequency of direct exposures to metal-laden mining residues as people
use these sites and watersheds during recreational activities.
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Chapter 4: Setting Goals and Measuring Success 4-3
4.3.2 Environmental Impacts
As mentioned above, much of the concern f^ith abandoned;mine sites impacts are related to
recreation and fishery resources and downstream agricultural activities. Abandoned mine sites
studies and response actions can occur in the context of drainage basins and watersheds,
beginning in the uppermost and often alpine headwaters, extending through lower reaches of
valley floodplains, and continuing down into mainstem river drainages where agricultural lands
and municipal-industrial users occur. Water quality standards which have been developed by
states are the initial targets for meeting clean water objectives; however, in some cases
protecting human health and meeting environmental improvement goals can mean going
beyond established standards. The process of making these decisions requires considerable
input and can result in a very dynamic and sometimes contentious debate and dialogue
between a variety of resource users and stakeholders. The values and choices of each of
these stakeholders is a very important and necessary part of the goal-setting and decision-
making process as determinations regarding the merits, cost-effectiveness and implementing of
studies and remediation are made.
4.3.3 Getting it Done
An excellent publication is available to support goal-setting efforts, entitled "Watershed
Partnerships: A Strategic Guide for Local Conservation Efforts in the West," prepared for the
Western Governors Association, 1997. The report states:
Watersheds serve as a useful unit of focus for a number of reasons. They can be
aggregated to include large streams and even major rivers or separated into small, local
areas. A watershed is a natural integrator of issues, values, and concerns which are
clear to see as the stream flows along its course. It exhibits clear evidence of
consequences.
Watersheds are a good starting point for people to understand the relationship of
people and natural resources in a management system. The current institutional
boundaries are generally mismatched to the hydrologic, ecologic, geographic, and
economic scope of natural resource problems and the affected communities and
interests. Watershed partnerships can help match societal interests to the resource
base. Over time, watersheds enhance participants' shared knowledge to increase the
collective competence for anticipated and responding to changes in resource goals...
By working together, everyone with an interest in the watershed can solve problems,
ensuring healthy land and water. Typically, partners represent wide interests: local
communities, various groups, and government agencies.
The report was developed to serve existing as well as new and emerging partnerships. The
report includes "collective wisdom from those who have pioneered watershed partnership
concepts" and addresses areas of interest in the following sections:
Foundations for Getting Started,
How to organize
What to Think About — Sooner or Later
External Factors
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4-4 Chapter 4: Setting Goals and Measuring Success
4.3.4 Values and Choices
Indirectly, processes for decision-making about what abandoned mine site work to address
already have been underway for some time. Under the Clean Water Act (CWA), state water
quality regulatory programs have established stream classifications and use attainability
designations for most waterways. Accompanying these stream use and classifications are
water quality standards that establish the goals and requirements for contaminant
concentrations. The CWA also requires the development of Total Maximum Daily Load (TMDL)
calculations to meet water quality standards where ongoing impairments are occurring. Similar
regulatory procedures and standards exist for air, soil, and groundwater contamination. At NPL
sites where CERCLA responses are occurring, not only do projects strive to meet the above
regulatory standards (referred to as Applicable or Relevant and Appropriate Requirements, or
ARARs), but also site-specific data is used in risk assessments to formulate risk estimates.
Subsequent cleanup and remediation decisions are based on selected levels of human health
and environmental risk reduction. Whether associated with CERCLA actions or other
regulatory and non-regulatory activities occurring in watersheds, agencies and programs
undertake a process of reassessing and modifying existing environmental standards.
Modifications to the above "regulatory processes" take considerable effort and are time-
consuming. While these regulatory processes will need to be engaged to varying degrees,
these are probably not the most efficient or productive forums through which Federal and State
agencies and local governments should work to make the strategic environmental response
priorities and decisions for the universe of abandoned mine sites at watershed and drainage-
basin levels.
As mentioned earlier, collaborative watershed partnerships are more likely to be an effective
sounding board for determining the values and choices which will focus abandoned mine site
efforts. Closely related to the WGA watershed partnership strategy mentioned earlier, EPA
strives to accomplish its efforts through a "Data Quality Objectives Process." the data quality
objectives (DQO) process is a systematic planning effort for ensuring that environmental data
will be adequate for their intended use. This process is key to abandoned mine site work in
order to integrate the desired goals and objectives wjth information appropriate for the
necessary decisions, and lastly the abiBty to measure success towards established goals.
These discussions and activities will provide an adequate foundation for planning and making
defensible abandoned mine site project decisions, and will also provide a basis for measuring
success.
4.4 Measuring Success
Much has been said above about establishing national, regional, state, tribal and local goals.
The planning and communication described above establish a basis for determining degrees of
progress towards the stated goals and a means to identify techniques that will be used to know
when the objectives have been met. These results and value-added measurements can
include a variety of discrete indicators, including:
Number of sites or acres that have been addressed,
• How many sources or volume of contaminated media have been remediated,
Water quality measurements,
Biological or aquatic toxicological indicators, and
Budget or schedule compliance.
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Chapter 4: Setting Goals and Measuring Success 4-5
4.5 Sources of Additional Information
For additional information on setting goals and measuring success at mining and mineral
processing sites, see the following documerYts: 'f* •;*
USEPA, OSW. 9-97. EPA's National Hardrock Mining Framework. EPA 833-B-97-003
Western Governors' Association. 2-97. Watershed Partnerships: a Strategic Guide for
Local Conservation Efforts in the West
Western Governors' Association. 1998. Abandoned Mine Cleanup in the West: A
Partnership Report (1998)
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4-6 Chapter 4: Settbig Goals and Measuring Success
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Chapter 5
Community Involvement
5.1 Introduction
The purpose of this chapter is to discuss community involvement planning for restoration and
cleanup work at. mine waste sites. Community involvement plannrig should parallel all aspects
of the site cleanup process from the onset of scoping to conclusion of site work. While the
relevant public participation requirements of the statutes under which the cleanup is taking
place must be met, these activities represent only a starting point for community involvement at
many sites. Additional guidance on'Super-fund community involvement requirements and other
community involvement activities can be found in the Superfund Community Involvement
Handbook & Toolkit1. This chapter presents the role of community involvement based on a
Superfund site, however the information and issues presented here are also relevant at a non-
Superfund mining site.
5.2 Considerations for Community Involvement at Mine Waste Sites
While every community is unique, there are circumstances at many mine waste sites that may
require special consideration when planning community involvement. This section will discuss
these considerations and suggest community involvement approaches for them.
5.2.1 Community Values and Culture
It is important for the site team to learn about
the communities that will be affected by the
site cleanup since the values and unique
culture of each community impact how area
residents react to cleanup efforts. Residents
in many communities located near mine
waste sites either are currently mining as an
occupation or have ties to mining. They are
proud of their mining heritage. They may
view mine wastes not as eyesores or sources
of risk, but as signs of economic vitality—a
reminder of the "good old days". Relics of
mining—tailings piles and ponds, waste rock
piles, cribbing, drainage tunnels-are
considered valuable historical features.
Highlight 5-1
Butte and Walkerville
The Butte Area portion of the Silver Bow Creek/Butte
Area site was added to theNPL in 1987. The people
of Butte were extremely unhappy about Butte and
Walkerville being listed on the NPL. One of the
residents' main concerns was that EPA would
conduct years of study and they would see no action.
Residents believe that EPA comes into a community
and states that there are potenSal health concerns
posed by the presence of heavy metals in residential
areas and then studies the site for several years. The
people of the community, especially parents, ace
thrown into denial and angry stages of the "grieving"
process. However, as EPA conducts the studies and
remediation, particularly expedited response actions,
the communities concerns are reduced and they
begin to cooperate with the Agency and a partnership
between the Agency and the residents can.develop.
Residents in mining communities, like the
residents in many other communities, are
reluctant to trust agencies and individuals
that they are unfamiliar with. It is important
to establish contact with local government and community groups as early as possible and to
maintain clear and candid communications.
'U.S. Environmental Protection Agency (EPA), December 1998. Superfund Community Involvement Handbook and Toolkit.
Washington, D:C. Office of Emergency and Remedial Response.
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5-2 Chapter 5: Community Involvement
Community involvement Tips:
These tips presented in this chapter are important to all communities, whether or not the site is
a Superfund site. Following these tips will help alleviate the community's concerns about any
economic impacts.
Know and Respect the Community. There is no substitute for knowing the community.
Rather than taking an inflexible stance that will increase public alienation, the team should
focus on joint problem-solving with the community. Spend time in the community so residents
get to know team members. Interview residents. Identify the formal and informal opinion-
shapers in the community and pay special attention to them. Appreciate the community's
heritage. Recognize the mining industry's importance to the community and the nation. One
RPM said, "I have memorized the names of all the local mines and read books about local
mining history. I've learned the lingo and even joined 'Women in Mining'."
Establish an Ongoing, Accessible EPA Presence. Because these sites frequently are
located in areas distant from the EPA regional office, serious consideration should be given to
providing for an ongoing EPA presence in the community. At some sites EPA has staffed an
office so that it is easily accessible to area residents.
Maintain Ongoing Communication. While no amount of good communication can make up
for poor technical decisions and project management, communicatbn can prevent
misunderstandings and build credibility when the technical and management decisions are
sound. Early, accurate, balanced, and frequent two-way communication should be planned.
The site team can benefit from the good will and credibility generated by frequent contact, by
the same site manager and other team members, with the community groups, task forces, and
individual residents. Generally, one-to-one and small group discussions work best in small
mining communities. While it is vital to work with local elected officials, it is also important to
identify and communicate through the community's informal networks using unofficial
community caretakers and opinbn-makers. It takes time to identify the networks and the
caretakers that are at their hub, but communicating through these sources is often more
effective than through more formal efforts.
Pay Special Attention to Historic Preservation Concerns. Involve the community from the
onset in designing the historic preservation plan. Encourage them to participate in historic
resource surveys and to prioritize the historic resources identified. Tailor cleanup plans, to the
extent possible, to preserving priority historic resources.
Empower the Community; Use Local Expertise, in most communities there is a vast
untapped resource of knowledge. Former miners know a great deal about the geology,
hydrology and historic mining practices in the area. Staff can profit from this expertise and
should encourage the local community to take advantage of its own experts. At some sites,
local representatives help agency staff design and implement sampling and monitoring plans.
Involve the Community in Planning and Implementing the Cleanup. At NPL listed sites,
encourage residents to apply for a Technical Assistance Grant (TAG). At non-Superfund sites,
stakeholder groups might apply for grants like the Regional Geographic Initiative to help fund
community-based participation. Technical Outreach Services for Communities (TOSC) is also
available for non-Superfund sites. Some communities form Community Advisory Groups (CAG)
that take an active role in deciding whether and how wastes in the area should be addressed. It
is important that EPA demonstrate its willingness to share control with bcal groups and be
responsive to recommendations from these groups. This is the heart of community-based
environmental decisbn-making. At many sites, staff meet regularly with stakeholder groups
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Chapter 5: Community Involvement 5-3
that include representatives from the community, PRPs, state, EPA and other stakeholders to
discuss site plans and reach informal consensus on them.
Conduct a Demonstration Project. The team should consider a demonstration project in
cases where the EPA is proposing soil remediation in residential areas. Residential cleanups
are intrusive. Lawns are torn up, trees are leveled, and prized flowers and gardens are
uprooted. Property owners' fears about the disruptive nature of the project sometimes are even
greater than the reality. They worry about the dust, mud, noise, and mess that the construction
will create. They fear that the end result will be a barren yard. Often a small scale
demonstration can calm some of these fears. Such a trial run may also result in lessons that
can be applied to the full scale cleanup.
Encourage Neighbors to Mentor Neighbors. As residential sofl cleanups progress,
encourage residents whose properties have been cleaned up to serve as mentors to
homeowners whose properties are slated for remediation.
5.3 Risk Perception
At some sites the perceived contradiction between EPA's assessment of a site's potential risk
and health tests, like blood lead tests, causes area residents to be skeptical of EPA's
contention that mining and mineral processing sites pose a threat to human health. These
wastes are familiar, they have been around for years and, in some cases, there is no visible
evidence of negative health effects in the community. Yet, EPA risk assessments indicate the
wastes pose a potential threat. The use of a computer model instead of blood lead tests for
determining the need for remediation is unacceptable to some communities. Residents
contend that EPA refuses to consider real concrete evidence and, instead, focuses on
theoretical abstractions based on assumptions and uncertainty. Sometimes citizens argue that
the proposed cleanup will pose more of a health threat than leaving the soil or wastes
undisturbed.
Community involvement Tips:
Use Skilled Risk Communicators. Good risk communication is especially important at mining
sites. Site staff should be trained risk communicators.
Provide Early Metals-Awareness Education. It is important to inform citizens of precautions
to take in order to reduce exposure to metals, particularly if it will be many years before a
cleanup takes place. It is necessary to take measures to protect the pubic health and to
demonstrate the agency's commitment to reducing health risks forthe local community.
Providing metals-awareness education to local health professionals, educators, day care
providers and parents will both help reduce exposure and remind citizens that mine wastes may
be a potential threat to health. Educational efforts may include workshops, seminars for college
credit, parent-teacher meetings, distribution of flyers to parents and coloring books to children.
At one site, a day-care facility teacher developed a song about being safe around lead and
taught it to the children. '
Work with Local Health Officials. EPA should encourage bcal health departments, health
professionals, and educators to take the lead in educating the community about site risks. In
fact, EPA should collaborate wherever possible with local and state environmental officials.
EPA can assist the effort by providing both general and site-specific information. However, it is
best if local health professbnals actually design the program and disseminate the information.
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5-4 Chapter 5: Community Involvement
Reduce Immediate Risks. Because the Superfund process can take a long time at large and
complicated sites, the time between identification of risk and actual cleanup may be several
years. To deal with the perception that the risk is not real because EPA is slow to begin action
and to reduce immediate health threats, the team should consider some interim actions such as
removals, interim remedial actions, or other expedited cleanups to show tangible results.
Removals have been very effectively used at some of the large mining sites in Montana and
Idaho.
Involve the Community in Assessing Site Risks. Local residents should help design risk
assessments-especially exposure scenarios. They know how their lives might bring them in
contact with mine wastes. Local land use plans may help predict future uses of property where
mine wastes are located. Exposure scenarios must reflect reality or the community will reject
the conclusions of the risk assessment. If health studies have been conducted in the
community, relate them to the risk assessment. There are many communication tools that may
help explain how risk assessments work including workshops, fact sheets, and presentations to
TAG or TOSC groups or CAGs.
5.4 Liability
Fear of liability under the Clean Water Act may prevent stakeholders who are not legally
responsible for cleaning up an abandoned mine waste site including governmental entities
("Good Samaritans") from volunteering to participate in discussions or undertake cleanup
activities that will provide incremental improvements in water quality. They fear that if their
cleanup actions do not result in water quaHty that meets Clean Water Act standards, they will be
held liable. While there is not a legislative remedy for this concern today, the Western
Governors' Association is working with Congress on amendments to the Clean Water Act that
will address the concern.
There may be Superfund liability concerns at mining and mineral processing sites. The law
holds those who generated the wastes potentially liable for cleanup costs. At mining and
mineral processing sites, however, many of the generators of historic wastes cannot be located.
EPA may pursue mining companies that operated the mine in the past as well as the mining
company that currently operates the mine, that may be a major employer in the area, for
cleanup costs. This may not seem fair to local residents.
The uncertainty of who will be responsible for cleanup costs weighs heavily on communities.
Because entire communities may be within the site boundaries, owners of small businesses and
small mining claims may fall within the broad Superfund definition of PRP because they are the
current owners of contaminated property. Local governments may own contaminated land or,
as is the case at some sites, may have moved or used mining and mineral processing wastes,
thus incurring potential liability.
Homeowners may fear that they will be liable for the costs of cleaning up contaminated soils on
their property or ground water under it. Lenders may be reluctant to make loans for fear that if
they foreclose and take over the property, they will be responsible for cleaning it up. It is
prudent to address these concerns up-front.
Community Involvement Tips:
Resolve Liability Quickly. It helps if EPA can resolve the liability question early. Settle as
soon as possible with small waste contributors. Let small mining claim owners and owners of
contaminated property who did not cause the contamination know where they stand at the
onset. The use of prospective purchaser agreements should be considered so that economic
activity can continue.
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Chapter 5: Community Involvement S-S
Address Property Concerns. It is important that project staff be sensitive to the community's
liability concerns and take steps to respondtjiiickly to fiiarify liability issues as they arise.
Information should be provided to local realtors and lenBerl describing the cleanup process,
lender responsibilities and protections, and EPA's ground-water and residential property owner
policies. Staff will need to work with the lending and real estate community at each site to
identify the best ways to address concerns about property values and liability. The team may
want to consider workshops and/or clearly written fact sheets to explain liability issues,
precautions to take before proceeding with property transactions, and options for dealing with
contaminated property in property transactions. At some sites, EPA has used 'comfort letters'
to ease liability concerns.
5.5 Economic Impacts
Superfund frequently is viewed as a threat to the community's economic well-being. If EPA has
named a major employer as a PRP, this contributes to economic concerns. Citizens fear that
the additional burden of Superfund may force the company out of business. Current mining
and mineral processing activities may, in fact, be hindered. Companies may be reluctant to
acquire mining claims and initiate new mining and reprocessing ventures because of the fear of
liability.
Highlight 5-2
Silver Mountain Ski Area
The community of Kellogg, ID, wanted to develop a
gondola base for the Silver Mountain Ski area within
the boundaries of the Bunker Hii Superfund site. The
community was concerned about any future liabilities
they may incur because of their economic
development action for the ski area. EPA negotiated
a prospective purchaser agreementwith the
community that limited their liability and helped
facilitate economic development with the Superfund
site.
Many mining and mineral processing sites
are abandoned facilities which have been
dormant for years. The attention Superfund
brings to them may cause both perceived
and real economic concerns to a currently
thriving community. The perceived stigma
may stifle economic growth in a number of
ways. Contaminated property may not be
desirable for further business development.
Banks may be reluctant to lend money for
development of such properties because of
liability concerns. Federal home mortgage
and lending agencies such as the
Department of Housing and Urban Development (HUD) and Fannie Mae also may be cautious
making loans on contaminated property, contributing to a drop in property values. Proposed
cleanup actions may threaten the historic mining features of the area, thus jeopardizing efforts
to encourage tourism, a fledgling industry in mining areas. These economic concerns
sometimes outweigh EPA's claim that the ultimate remediation of contamination will result in
economic benefit to the community in the future by improving property values and eliminating
threats to waterways and other scenic areas.
Economic concerns can easily become the focus of a great deal of tension between site
remediation teams and the local community. Recognizing and attempting to address economic
concerns can be crucial to carrying out remedial activities. In many communities the concerns
identified above have been addressed by EPA and communities have been able to function
normally, notwithstanding Superfund concerns, but it takes work and commitment by EPA and
the local commu nity.
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5-6 Chapter 5: Community Involvement
Community Involvement Tips:
Use Local Businesses Where Possible. EPA can help local workers get the OSHA 40-hour
Health and Safety at Hazardous Waste Sites training and can show local businesses how to bid
on Superfund contracts if they are not already familiar with the procedure. At some sites
proposed work has been divided up into smaller contracts so that local business can bid
competitively on the work.
Explore Partial Deletions from the National Priorities List (NPL). EPA policy allows sites,
or portions of sites that meet the standard provided in the NCP (i.e., no further response is
appropriate), to be the subject of entire or partial deletion from the NPL (60 FR 55466). A
portion of a site to be deleted may be a defined geographic unit of the site, perhaps as small as
a residential unit, or may be a specific medium at the site such as ground water, depending on
the nature or extent of the retease(s). To reduce the site-wide Superfund "stigma," properties
within the Superfund site that are known to be free of contamination should be publicly
identified.
Resolve Land Use Issues. EPA's Brownfield's Initiative provides mechanisms for removing
some of the bam'ers to economic redevelopment. EPA staff should work with the community to
address and resolve future land use issues as early as possible so that cleanup plans can be
tailored to the projected future tend use.2 Prospective purchaser agreements may be beneficial
both to those who are interested in redeveloping the property and to EPA.3
Establish a Process for Responding Realtors and Lenders. Identify a contact person who
will respond to inquiries from realtors and lenders about specific properties. Whenever
possible, provide comfort letters to property owners whose property has been cleaned up or
will not require remediation. Negotiate prospective purchaser agreements with buyers who are
willing to undertake cleanup work. These activities take time but the return in community good
will is worth it. . .
5.6 Fiscal Impacts on Local Government
A cleanup may put special strains on the budget of local government. Reduced assessed
property valuations lead to decreased property taxes and reduced local government revenues,
while cleanup activities may necessitate the expenditure of local dollars for such things as
street repairs, street cleaning, and institutional controls. Institutional controls such as land use
restrictions are frequently a component of remedies at mining and mineral processing sites.
These restrictions may affect the marketability of local properties. Institutional controls may
also place limits on excavations, require maintenance of grass cover, etc. Such land use
restrictions require long-term public education. Local governments may balk at being
responsible for this long-term outreach.
Community Involvement Tips:
Set Up a Trust Fund. At some sites, EPA has required the company responsible for the
cleanup to establish a trust fund for long-term monitoring and outreach. At other sites, the
agencies have helped establish trust funds to aid the local government.
•- See OSWER Directive 9355.7-04, May, 1995. "Land Use in the CERCLA Remedy Selection Process."
' U. S. Environmental Protection Agency (EPA), Jure. 1989. Guidance on Landowner Liability Under Section 107(a)(1) of
CERCLA. De Minimis Settlements Under Section 122(g)(l)(b) of CERCLA, and Settlements with Prospective Purchasers of
Contaminated Properties.
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Chapter 5: Community Involvement 5-7
Identify Opportunities for Cleanup to Benefit Local Government. At some sites, agency-
generated Geographic Information Systems (GIS) data can also provide maps and other
information that local government can use |pr land Useltplapning and property assessment
purposes. Aerial surveys used for cleartup?*planning have also been useful to local
governments and other stakeholders for purposes unrelated to the cleanup. At one site where
the cleanup called for capping mine wastes, a portion of the cap was used for an asphalt
bicycle trail and another section will be a city-maintained sledding hill.
Meet the Political Needs of Local Officials. Small communities expect that their local
officials will look after their interests. Local officials feel a responsibility for and receive political
benefit from close oversight of agency work. Staff must remember to keep local officials
informed and involved throughout the cleanup process.
5.7 Federal Land Managers
Many abandoned mine waste sites are located on federal lands or a mixture of federal and
private lands—Forest Service, Bureau of Land Management, National Park Service, U.S Fish
and Wildlife Service. When this is the case, federal land managers will be important players in
the cleanup process. Sometimes, in fact, they will be the lead agency responsible for
overseeing all or a portion of the cleanup using CERCLA authority. In other cases, they may be
liable for some of the cleanup work. In still other cases, they are the trustees for natural
resources. Multiplicity of roles for multiple agencies may cause confusion in the community
unless there is a close working relationship among the federal agencies involved at the site and
each agency's role is carefully explained. To gain a better understanding of the authority of
land managing agencies and EPA under CERCLA read Executive Orders 12580 and 13016.
Community Involvement Tips:
Involve Stakeholders in Decisions on the Cleanup Process. When a wide range of options
are available for addressing the cleanup—different laws, different agencies taking the lead, a
combination of private and public responsibilities, etc.—it is important to carefully explain the
options and involve the community in the decisions on the cleanup plan.
Clarify Agencies' Roles. Carefully explain the role each federal agency will play at each step
in the process.
Include Federal Land Managers in Stakeholder Groups. If a stakeholder advisory group is
formed, include federal land managers in the group.
5.8 Uncertainty
The cleanup process can be slow and it may take some time before there is evidence of actual
cleanup. Because property values and marketability are sometimes affected, residents want to
know whether their properties are in or out of the site boundaries. EPA is frequently unable to
give an answer to this question until studies are complete and all data are available.
Citizens want to know if their property will require remediation. They feel they must defer
decisions on remodeling, landscaping, gardening, and other activities until they know whether
their property is contaminated or when it will be remediated. Again, EPA may not have an
immediate answer to their questions. This increases the sense of uncertainty and frustration of
the local community.
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5-8 Chapter 5: Community Involvement
Community Involvement Tips:
Establish Site Boundaries Early. While making it clear that new information may change the
boundaries, the team .should clearly describe the areas that are under investigation and should
provide information on the location of contaminated areas. When information is not available,
residents should be told when it will be collected and made public.
Identify and Reduce Areas of Uncertainty. Staff should clearly identify areas of uncertainty,
whether it be extent of contamination, nature of cleanup planned, site risks or liability. They
should explain how and when uncertainties will be resolved and immediately communicate new
information that will remove uncertainty. Where uncertainties remain, the site team should
explain how cleanup plans will be adjusted to take the uncertainties into account.
5.9 Additional Sources of Information
Additional information concerning EPA's Superfund community involvement programs, including
a list of publications available can be found on the EPA website at:
http://www.epa.gov/superfund/toolsyindex.htm.
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Chapter 6
Scoping Studies of Mining and Mineral Processing Impact Areas
6.1 Introduction
The purpose of this chapter is to discuss the scoping process at abandoned mining and mineral
processing sites. The first section of the chapter will present background information on the
scoping process in general. Details on the individual tasks associated with the scoping process
used under CERCLA can be found in Chapter 2 of the Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA.'1 The terms used in this chapter to
identify scoping and activities are those used in the guidance. These procedures will prove
valuable whether CERCLA or some other authority guides cleanup activities. The remainder of
the chapter will address problems and issues to consider when scoping an abandoned mining
or mineral processing site.
6.2 Scoping
The broad project goals for an investigation at an abandoned mine site are to provide the
information necessary to characterize the site, define site interactions, define risks, and develop
a remedial program to mitigate observed and potential threats to human health and the
environment. The purpose of scoping is to:
Establish a procedure for determining the nature and extent of contamination associated
with the site;
Identify possible response actions that may be requred to address contamination at the
site;
Determine whether interim or removal actions are needed to reduce risks, prevent
damage, or mitigate current threats; and
Divide the broad prq'ect goals into manageable tasks that can be performed within a
reasonable period of time and with a logical sequencing of activities.
Because of these activities, scoping should be conducted for any cleanup project, regardless of
the administrative framework bang considered for the action. While a mine site cleanup may
not require that a traditional RI/FS be developed, the framework provided by that activity may
prove useful in scoping and planning. For example, the RI/FS typically includes preparation of
the following: a project work plan, a sampling and analysis plan (SAP), a health and safety
plan, and a community relations plan.
The Work Plan. The work plan documents the decisions and evaluations made during the
scoping process and presents anticipated future tasks. Five elements are included in the
typical work plan: (1) an introduction, (2) site background and physical setting, (3) initial
evaluation, (4) work plan rationale (including the identification of data needs and data quality
objectives), and (5) tasks to investigate and cleanup the site. The information necessary to
complete the work plan will become available as the tasks associated with scoping are
completed. Additional information on the elements of a work plan can be found in Appendix B
of the Guidance for Conducting Remedial Investigations and Feasibility Studies Under
CERCLA. At many sites, including large mining or mineral processing sites, the work plan may
have to be amended as additional information (data) is acquired. Separate work plans should
1 U.S. Envirormental Protection Agency (EPA), October. 1988. Guidance for Conducting Remedial Investigations and
Feasibility Studies Under CERCLA. Washington. D.C. Office of Emergency and Remedial Response.
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6-2 Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas
be prepared for major elements of the site investigation, analysis of cleanup alternatives, and
design of cleanup actions.
/
The Sampling and Analysis Plan. The Sampling and Analysis Plan (SAP) ensures the
consistency of sampling and data collection practices and activities over time, and ensures that
data needs and quality objectives developed in the work plan are met. A SAP should be
developed concurrently with the work plan. The plan should be prepared before any field
activities begin, and should consist of two parts: (1) a quality assurance project plan (QAPP),
which describes the policies and activities necessary for achieving data quality objectives
(DQOs) for the site; and (2) the field sampling plan (FSP), which provides guidance for all field
work by defining in detail the sampling and data-gathering methods to be used in the project.2
The sampling and analysis process and sampling and analysis issues at abandoned mining and
mineral processing sites are addressed in greater detail in Chapter 7 of this handbook.
The Health and Safety Plan. Health and Safety Plans (HSP) are frequently included as a part
of the work plan, but may be submitted separately. Typical elements of an HSP include: names
of site health and safety officers and key personnel; a health and safety risk analysis for
existing site conditions; employee training assignments; a description of personal protective
equipment used by employees; medical surveillance requirements; a descriptbn of the
frequency and types of air monitoring, personnel monitoring, and environmental sampling
techniques and instrumentation to be used; site control measures; decontamination
procedures; standard operating procedures for the site; a contingency plan that meets the
requirements of 29 CFR 1910.120 (i) (1) and (i) (2); and entry procedures for confined spaces.
Specific HSP issues for mining sites include physical-hazards such as open shafts, subsidence,
steep slopes, landslide potential, remoteness of sites, and chemical hazards from .
contaminants. Structures can present a special hazard at mill sites and abandoned processing
facilities (e.g., buildings may be unsafe for entry, or contain high concentration residues).
Additional information on the Health and Safety Ran can be found in Appendix B of the
Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA.3
The Community Relations Plan. Community relations planning is particularly important when
the extent of contamination and appropriate response actions are being determined at mining
and mineral processing sites where the community is impacted. Community relations activities
keep the community informed of site activities and help Superfund personnel anticipate and
respond to community concerns. The Community Relations Plan, which documents these
activities, should include the following sections: an overview of the plan, a capsule site
description, background information about the community, highlights of the community relations
program, information about community relations activities and timing, a contact list of key
community leaders and "nterested parties, and suggested bcations for meetings and
information repositories. Additional information on community relations can be found in
Chapter 5 of this reference document.
2Guidance for the selectbn of field methods, sampling procedures, and custody samples can be acquired from U.S.
Environments! Protection Agency. Compendium of Superfund Field Operation M&hods. 1987.
3U.S. Environmental ProtecSon Agency (EPA), October 1988. Guidance for Conducting Remedial Investigations and
Feasibility Studies Under CERCLA. Washington.. D.C. Office of Emergency and Remedial Response.
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Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas 6-3
6.3 Difficulties in Scoping Abandoned Mine Sites
There are a variety of characteristics of abandoned -mine sites that make the scoping and
completion of characterization and cleanupfabtivitiesjclBmRlex. The following is a discussion of
some of the issues that can be encountered in scoping an abandoned mining and mineral
processing site.
Size and Location of the Site. Some, although certainly not all, abandoned mine sites have
impacts over large areas, especially if mining areas or districts or impacted watersheds are
considered. In addition, some abandoned mines sites may be more difficult to characterize and
cleanup because of their remote locations, in some cases without road access and/or located at
high altitudes areas. The size and Ideation of abandoned mine sites can make remediation
planning, site characterization, and actual remediation complex.
Volume of Contaminants. Typical of some abandoned mining operations is the removal of
large volumes of waste material during the mining process. Furthermore, beneficiation and
mineral processing operations, which are often co-located with mining operations, typically
generate very large volumes of process waste. As an example, one tailings impoundment in
the now closed Anaconda mine/smelter site near Butte, Montana covers more than 1000 acres
and ranges in depth up to 100 feet. These large volumes make traditional remediation (such as
excavation, stabilization, and landfilling) economically difficult even if technical issues can be
resolved. Furthermore, due to the large volumes, complete removal or remediation of the
problem may not be possible, or remediation may take place in a phased approach.
Type of Wastes. There may be numerous different types of waste at abandoned mining and
mineral processing sites. These wastes could include tailings, slags, overburden, waste rock,
ore stockpiles, and remaining process chemicals. A variety of sampling strategies may be
needed to characterize each waste type.
Persistence of the Contaminants. Metals, often a primary contaminant at abandoned mine
sites, do not readily decompose or biodegrade into less toxic byproducts as do volatiles and -
some organic compounds. Therefore, mine sites abandoned for decades or even centuries
can still have metal concentrations at levels of concern. Furthermore, metals that are not of
toxic concern can generate other problems that can occur for decades, such as acid
generation.
Variety of Media Affected. Contamination at abandoned mine sites often affects many media.
Surface water and ground water are frequently contaminated by metals leached from mining
and mineral processing wastes and by acid generated within the mines or waste units. Soils
are often contaminated onsite by historical waste management practices and offsite by fugitive
dust and smelter emissions. Sediments within surface waters may also contain contaminants.
In addition, the air maybe recontaminated during remediation operations or by fugitive dust
blown from abandoned waste units. The wide dissemination of contamination at some mining
and mineral processing sites generally requires the collection of a large variety of data from
several different sources. Information about sources, migration pathways, and human and
environmental receptors is generally critical to characterizing the site and formulating plans for
possible remediation alternatives.
Historical Mining Areas. Abandoned mine sites are often located in areas where the
remnants of mining activity is considered to be historical. The local population is often deeply
rooted in the mining and mineral processing activities, and environmental investigations
undertaken by site managers must take this into consideration. Historical preservation is an
issue at some sites. Historical artifacts, including old mine buildings, mine openings, and
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6-4 Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas
associated towns now abandoned, may be located on the site and their continued presence, as
well as access to structures, is expected to remain despite remediation activities. Finally, the
long history of mining and mineral processing in these areas often poses problems in
determining levels of metals naturally occurring in the local water and soils prior to mining
activity.
On-going Mining and Mineral Processing. Some abandoned mine sites may be affected by
ongoing mining and mineral processing nearby. Often, mines abandoned as uneconomic
utilizing past technologies have been reopened using new technologies or when prices rise. In
other cases, neighboring claims and associated processing operations continue to operate.
Where these new operations or historical neighboring operations are being conducted,
sampling, risk assessment, and remediation may have to be modified. Any remedial actions on
the site may be affected by ongoing mining and mineral processing operations. Ongoing
mining and mineral processing operations can greatly affect both the data collection process
itself and the quality of the data collected. Isolating the effects of ongoing operations from
waste generated in the past can be challenging. Additional health and safety protocols may
have to be taken into consideration if mining and mineral processing activities are occurring on
the site. Efforts must be coordinated with mining and mineral processing operators to ensure
the safety of remediation teams.
Location in Non-Industrial Areas. Many mining and mineral processing sites are located in
areas that otherwise would be considered non-industrial natural resource areas. The Bunker
Hill site in northern Idaho, for example, is in forested mountain country; however, large areas of
the site have been denuded of most .vegetation. Local governments or other entities
associated with old mining and mineral processing areas may want a total cleanup because
they are seeking an inflow of recreational dollars. They may also, however, want no cleanup
because of their desire to avoid the stigma of a Superfund site or they may want to retain the
historic features.
Because many abandoned mine sites are located in or near non-impacted environments, the
ecological risk assessment can become more important, particularly if the human population
around the sites is small or nonexistent.
6.4 Scoping Issues Associated with Mining and Mineral Processing Sites
Abandoned mining and mineral processing sites can present many challenges and issues
during scoping. Characterizing mining and mineral processing sites and identifying problems
and potential solutions can be very complex, particularly at the large sites where both mining
and mineral processing have occurred. The remainder of the chapter will present important
issues for consideration when scoping a mining and mineral processing site.
6.4.1 Operable Units
The size of abandoned mining and mineral processing sites can create special challenges for
tasks associated with the scoping process. Sites are often far too large to address in a single
response action, and the actions selected may require a longer time frame to undertake than is
common for other smaller or more contained sites., For this reason, mining sites are often
divided into smaller units, which are called Operable Units (OUs), that are then characterized
both individually and as part of the whole site. The term Operable Unit has specific meaning
under CERCLA, which may differ somewhat from the description in this chapter. Also, because
human health may be of critical concern in some areas it may be appropriate to focus on units
that impact human health first, with ecological considerations being investigated as a distinct
unit.
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Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas 6-5
Establishing Operable Units. While there are no definitive criteria for designating units, many
area-specific factors are used: (1) similar contamination of waste material or environmental
media (e.g., soils, flue dust, or ground water); (2) simjjar geographic locations; (3) similar
potential cleanup techniques; (4) potenjiallf similar
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6-6 Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas
Exhibit 6-2
Primary Threats at Superfund Mining and Mineral Processing Sites
Major Contaminants
Naturally Occurring: Lead, Zinc, Copper (and other heavy metals), Arsenic, Cadmium, Mercury, Antimony,
Selenium, and Uranium
Introduced During Extraction, Beneficiation, and Processing: Cyanide, acids, bases, PCBs, asbestos,
and others
Sources of Contamination
Mined Areas: Open pits, mine shafts, and tunnels
Impoundments: Tailings, run-off collection, wastewater treatment, and leaching solution ponds
Piles: Overburden, tailings, slag, air pollution control dust
Sediments: Sediments in river beds, mine pits, and drainage channels
Processing: Slag, air pollution control residues, wastewater, treatment sludges, and deposition of stack
emissions
Exhibit 6-3
Receptors and Pathways
Human Receptors and Pathways
Inhalation of contaminated/radioactive fugitive
dust
Consumption of contaminated drinking water
wells and aquifers
Ingestion of contaminated fish, vegetables, soil,
or wildlife
External exposure to radionuclides _^
Ecological Receptors and Pathways
Potential fish kills and degradation of aquatic
systems from direct contaminant exposure
Riparian vegetation kills along contaminated
streams/rivers
Wildlife exposure to contaminated soils and waters
If an overall site management plan is prepared, it should reflect the relationships between units
and the danger of recontaminating an area where cleanup has been completed. The
excavation or movement of contaminated materials at one area of the site may affect air,
streams, rivers, or ground water, and may affect locations downwind, downstream, or
downgradient. In additbn, remediating a heavily contaminated area without remediating the
source couid result in later recontamination. These considerations should be important ones in
making sequencing decisions for investigating response actions where multiple units exist.
6.4.2 Interim Actions
Interim actions may be appropriate for some units to protect human health and the environment
from an immediate threat in the short term while a final remedial solution is being developed, or
to stabilize a site or units with temporary measures to prevent further migration or degradation.
Examples of interim actbns taken at mining sites include: providing bottled water or temporary
well filters to residents until private wells are reclaimed or water supplies are provided;
relocating contaminated material from one area of a site (i.e., residential yards) to a more
remote area of the site for temporary controlled storage; and temporarily capping waste piles to
reduce fugitive dust until a more permanent remedy can be performed. Interim actions are
discussed further in Chapter 9 of this reference document.
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Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas 6-7
6.4.3 Unusual Requirements
There are many statutes that may be applicable to raining and mineral processing sites but
would not ordinarily be considered apprpprtefl for othlr sites (e.g., Endangered Species Act,
National Historic Preservation Act, the ArcheologicaLand Historic Preservation Act, the Historic
Sites, Buildings, and Antiquities Act, etc.). These statutes may be identified as Applicable or
Relevant and Appropriate Requirements (ARARs) at CERCLA sites.
In addition, there are certain circumstances under which ARARs may be waived; these are
stipulated in the NCP (40 CFR 300.430(f)(1 )(ii)(C). Given the possibility of unusual site
characteristics at abandoned mining and mineral processing sites (e.g., difficulty with
background levels, large size, location, and multimedia effects), waivers may be necessary at
these sites. Chapter 11 of this handbook discusses issues for ARARs at mining and mineral
processing sites in greater detal. In addition, Appendix D of this handbook provide a general
discussion of some of the most common federal ARARs at Superfund mining sites.
6.5 Sources of Additional Information
Additional information on scoping studies can be found in EPA-OERR's October 1988
Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA
Another source of information can be found on the EPA website, including the information at
http://www.epa.gov/sup3rfund/whatissf/sfprocess.h1m.
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6-8 Chapter 6: Scoping Studies of Mining and Mineral Processing Impact Areas
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Chapter 7
Sampling & Analysis of Impacted Areas
7.1 Introduction
The purpose of this chapter is to introduce concepts and issues related to designing and
implementing a sampling and analysis program for characterizing mining and mineral P™e>s,ng
site waste management areas. This part of the planning process provides a path to Pncntang
remedial actions and setting realistic goals, because it may not be possible to completely remove or
remediate areas that may occupy many square miles
Section 7.2 will present general information about the sampling and analysis process The
****** *
.
individual tasks associated with sampling and analysis can be found ,n
Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA . The
terms used in this chapter to identify sampling and analysis activities are those used in the
. guidance. For non-CERCLA actions the site manager is advised to cons.der CERCLA guidance in
the context of site specific needs and circumstances.
Mining and mineral processing sites present many problems and issues that are not characteristic of
other sites Section 7.3 of the chapter will present unique characteristics of mining and mineral
processing sites and briefly discuss how these characteristics can affect the sampling and analys.s
program. The remainder of the chapter will address issues associated with sampling and analysis
at abandoned mining and mineral processing sites.
7.2 Sampling and Analysis
During the scoping process, any data for the site that is available will be collected reviewed and
analyzed and the need for additional data defined. A sampling and analysis effort will likely be
required to provide this additional data. A sampling and analysis plan (SAP) is a necessary part of
the investigation and remediation process. This plan can be revised as sampling and analysis
efforts are implemented.
The SAP is a document that specifies the process for obtaining environmental data of sufficient
duality to satisfy the project objectives. Defining data quality objectives (DQOs) is the most
important preliminary activity in creating an SAP. The DQO process offers site managers a way to
plan field investigations so that the quality of data collected can be evaluated with respect to the
data's intended use.
The outputs of the DQO process feed directly into the development of the two parts of the SAP: the
quality assurance project plan (QAPP) and the field sampling plan (FSP . The FSP describes the
number, type, and location of samples and the typefs) of field and analytical analyses; whereas the
OAPP describes the policy, organizational, and functional activities necessary to collect data that
w^and up tolgal and scientific scrutiny. The SAP integrates the DQOs, FSP and QAPP into a
plan for collecting defensible data that are of known quality adequate for the data s intended use
More information on the tasks associated with generating the SAP can be found in .Chapter 2 of the
Guidance for Conducting Remedial Investigates and Feasibility Stud,es Under CERCLA
Problems and issues that arise while creating and implementing the SAP will be d.scussed in the
remainder of this chapter. .
•'-U S Environmental Protecfon Agency (EPA), October, 1988. Guidance for Conducting Remedial Investigations and
Feasibility Studies Under CERCLA. Washington, D.C. Office of Emergency and Remedial Response.
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7-2 Chapter 7: Sampling & Analysis of Impacted Areas
7.3 Issues for Sampling at Mining and Mineral Processing Sites
There are several important issues to consider in developing a sampling and analysis plan for an
abandoned mining and mineral processing site. Mining sites may pose different sampling and
analysis challenges than other hazardous waste sites contaminated by organic compounds and
metals. The potential forwidespread variable contamination is tremendous and the size of the site
and volume of the contaminants can greatly complicate sampling and analysis efforts.
7.3.1 Defining Analytical Data Needs
This section briefly discusses analytical data needs and sources of analytical services for managing
a sample analysis effort under the Superfund Program. Site managers of non-CERCLA
investigations should select elements appropriate to their specific site. The key component in
defining the analytical program needs for a mining and mineral processing site is to talk with fate
and transport experts and environmental risk assessment experts to determine the forms of metals
and other site contaminates (e.g., cyanide) that should be investigated. A clear understanding of
the mining and mineral processing operations that have occurred on the site wiH greatly contribute
to planning the investigation.
The particular type of data that needs to be generated depends on the project needs. The project
needs are expressed as qualitative and quantitative DQOs which are developed in the project
planning process.
Screening data. Screening data at mining and mineral processing sites can help to reduce
initial sampling costs; analyses are conducted by rapid, less precise methods, with less
rigorous sample preparation. Screening da^a provide anaiyte identification in the absence of
historical site information. The x-ray fluorescence (XRF) analytical method is often used for
screening data to increase the representativeness of the sampling quickly. See Sectbn
7.3.7 of this chapter for more information on analytical methods and Appendix E for more
information on the XRF method.
Definitive data. Definitive data are generated using rigorous analytical methods, such as
approved EPA reference methods. Data are analyte-specific, with confirmation of anaiyte
identity and concentration.
7.3.2 Understanding Pre-mining Conditions
At certain sites, the samplhg plan can provide a useful tool to determine whether a release or
threatened release represents conditions altered by human activity. This information could be used
to determine whether a response action would trigger the exception contained in CERCLA section
104(a)(3)(A). That section restricts in certain respects the authority of the federal government to
take a CERCLA response action in response to a release or threat of release "of a naturally
occurring substance in its unaltered form, or altered solely through naturally occurring processes or
phenomena, from a location where it is naturally found." This narrow exception applies where a
release or threatened release is unaltered by human activity. Quite often, the impacts of mining are
obvious, so a fairly simple sampBng plan or site review can demonstrate that the releases are
altered and therefore not covered by the exception contained in CERCLA section 104(a)(3)(A). If the
exception does not apply, the degree of cleanup is governed by CERCLA section 121 and the NCP.
Neither sections 104, 121, or the NCP require the agency to determine the pre-mining metal levels
as a limit on the CERCLA response action. A review of natural background levels might in some
case be considered in the analysis of ARARs or technical impracticability. In some instances, an
investigation of the natural background condition can also assist the agency to determine the
feasibility of achieving cleanup goals.
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Chapter 7: Sam pling & Analysis of impacted Areas 7-3
At mine sites, determining the pre-mining baseline condition can be a difficult or impossible task
because mining activities often disturb mineralization in profound ways. Mining activities, such as
removing overburden, tunnelling into the ground and removing ore, often expose previously
protected mineralization to accelerated oxidation. These;activities can also change ground water
and surface water flow regimes, which can facilitate the release of metals into the environment.
Other factors also complicate efforts to determine pre-mining conditions at disturbed mineralized
deposits. In many cases, mineralized areas are highly heterogeneous. Highly variable conditions
reduces the ability to determine whether any particular area is undisturbed and representative of
pre-mining site-wide conditions. Moreover, ground water sampling efforts can disturb and expose
the mineralization. This disturbance can elevate metal concentrations in the sample well above the
levels present in an undisturbed condition, causing misleading results regarding the undisturbed
condition Moreover, efforts to associate releases to particular areas through metal ratios is
complicated by seasonal variability and chemical and physical processes that occur as the water
moves from the mineralized area to the sampling point. The unique nature of each mineral deposit
also limits the abifity to rely on undisturbed mineralized areas in other geographic locations as
representative of the pre-mining conditions at the subject site.
Mineral processing activities can also complicate the study of pre-mining conditions. Mineral
processing operations can deposit mine processing dust and waste over areas several square miles
in size.
While statistical methods that rely on site chemistry may not be appropriate at most mine sites, in
some cases non-chemical data can be used to infer pre-mining conditions. For example, evidence
may indicate that prior to mining a stream supported aquatic Hfe while after mining the stream does
not support an aquatic community. This information would indicate that the pre-mining releases
were relatively small relative to the post mining condition. Anecdotal evidence from the pre-mining
period can also provide information regarding metal concentrations.
If chemical analysis will be used to differentiate unaltered naturally occurring releases from altered
releases, it will be important to select appropriate "reference area" locations. A background
sampling location should usually be upwind and upstream of the site. In other cases, a nearby
watershed, unimpacted by mining, may provide an appropriate site for background water samples.
In either case, the site should have soil characteristics and related properties similar to those that
would have existed at an undisturbed portion of the site. If several different types of soil or habitats
are present at the site, the site manager may need to gather more than one set of background data.
The heterogeneous nature of mine sites, coupled with widespread contamination problems
associated with mining, can greatly complicate reliance on a nearby reference site.
In selecting a reference area, the risk assessor should also consider anthropogenic contributors
other than mining. For example, if a busy highway runs through a proposed background sampling
area, the same or a similar highway should be associated with the mine waste site to account for
leaded gasoline deposition. Locations that reflect obvious contributions of human activity, such as
roadsides, drainage ditches, storm sewers, should generally be judged as inappropriate for
collected background samples. .
If background sampling is deemed necessary, it will be important to understand early in the process
the ways in which the data will be used. For example, to ensure that spatially relevant and
statistically significant results can be obtained, the assessor should design a plan to ensure that the
assessor collects an adequate number of samples over an appropriate area and in a relevant
pattern.
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7-4 Chapter 7: Sampling & Analysis of Impacted Areas
7.3.3 The Importance of Site Characterization
Prior to developing an actual sample collection strategy, proper characterization of the mining and
mineral processing site should be conducted including:
Reconstructing pre-mining conditions;
Inventorying what has been deposited above-ground;
Obtaining records to determine the geology of areas where underground mining occurred;
Monitoring the movement of both surface and ground water; and
Estimating the impact of mining and mineral processing disturbances.
A thorough site characterization should include an understanding of the different mining and mineral
processing processes that occurred since mining and mineral processing operations began. This
type of information can be very helpful in anticipating all of the different types of waste that may be
encountered at the site and determining where sampling should occur to obtain accurate data (see
Chapter 2 for a discussion of mining and mineral processfrig processes). For example, milling
operations generate very different wastes from smelting operations; and knowing which processes
occurred at what time will help direct where samples should be taken and how they should be
analyzed. A complete site characterization may also minimize sampling needs, thereby saving time
and money.
There is a great deal of information available regarding historical mining and mineral processing
sites that is helpful in site characterization. Mining companies may have significant background
information from pre-mining exploration as well as information on how the site appeared before
mining activities (This information may be important in developing long-term structurally stable
cleanup plans). The information collected by the U.S. Geological Survey (USGS) and U.S. Bureau
of Mines, now in the Office of Surface Mining (OSM), may be good sources of pre-mining site
characterization data. State geologic or mining divisions also can have extensive historb mining
databases. Historical production records from the mining and mineral processing operations may
be kept by local historical societies. These records could provide tonnages, grades, and
concentration methods. State mine inspector reports may also be used as a source of tonnage,
grade and information on significant changes in the mining and mineral processing operations.
Newspaper articles, books written about the mine or mining district, annual reports of mining and
mineral processing companies, and work by government agencies may also provide information that
will help determine where to sample, what contaminants to expect, and the range of concentration
to anticipate.
Once the history of the mining and mineral processing site is characterized, the sampling strategies
selected should be appropriate, based on pre-specified DQOs. Time consuming or expensive
sampling strategies for some media may prohibit multiple sampling points; consequently it is
important to balance the samping objectives against the time and costs involved.
7.3.4 Calculating Preliminary Cleanup Goals
Preliminary Cleanup Goals (called Preliminary Remediation Goals (PRGs) under CERCLA) at
mining and mineral processing sites can be used to focus cleanup efforts on a risk basis,
concentrating sampling efforts in areas posing the highest risk hazards. Site specific cleanup goals
can be calculated based on the environmental pathway at the site and the potential receptors.
Setting preliminary cleanup goals is useful in focusing early action and site characterization goals
while a site specific risk analysis is undertaken and should be included in large site cleanup projects.
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Chapter 7: Sam piing & Analysis of impacted Areas 7-5
Risk analysis efforts can be scaled back for smaller or more remote sites. PRGs may be useful in
establishing detection limits required for analytical samples.
7.3.5 Selecting a Qualified Analytical Laboratory • •«;
Mining and mineral processing waste samples can pose unique analytical requirements. Samples
often have a low pH level; contain several metals, often at high concentrations and varying
solubilities; and vary widely in particle size. In selecting a qualified analytical laboratory, it is critical
to consider the complexity of the sample matrix which will be analyzed. Site managers should
select a laboratory that can handle the specific needs of their site and meet the established DQOs.
Portable analytical laboratories , if used should be selected with the same criteria.
If an EPA Contract Laboratory Program (CLP) laboratory is selected, it is important to realize that
the lab may not be experienced in analyzing mining and mineral processing waste. The routine
sample preparation procedures and the pre-specified detection limits that the CLP process uses
may not be applicable for mining and mineral processing waste samples. The site specific
conditions will determine if a CLP laboratory is appropriate. These will include the need for
specialized services, such as the acid-base account or humidity cells. In addition, if the
concentration of contaminants in these samples is expected be orders of magnitude above the
detection limit, the sample may not be accurately analyzed with the CLP procedures unless the lab
is advised upfront. These factors are important when the site manager is considering what
laboratory should perform the sample analyses for their specific site.
7.3.6 Determining the Leachability of Contaminants
The first critical step in selecting analytical methods appropriate to mining and mineral processing
sites is the recognition that metal speciation is an important factor affecting the mobility and toxicity
of metals at mining and mineral processing sites. Metals form different chemical compounds on the
basis of their pH and oxidation-reduction potential, as well as the nature of the aqueous chemical
environment. Different metal species form compounds with different solubilities, activities, toxicities,
and environmental fates. Identifying these species at mining and mineral processing sites is
extremely important in understanding a site, making assessments concerning environmental and
human health risks, and arriving at reasonable decisbns concerning cleanup actions. Interpretation
of fate and transport potentials based on static and kinetic tests depends on the nature of the test
(e.g., solvent duration) and the nature of the samples (e.g., tailings [fine particles, more surface
area] versus some slag [coarse material, less surface area]).
The fate and transport of various chemical constituents from mining and mineral processing wastes
can be evaluated by conducting static and kinetic tests. Tests can be used to determine if a waste
is hazardous; the sample results depend upon the material(s) being tested. The most common test
used internationally for mining and mineral processing waste samples is the Acid-Base Account.
Since the 1970's variations of the Acid-Base Account have been used. These methods are based
on measuring the total sulfur content in the sample to determine the amount of acidity that could be
produced if all the sulfur were oxidized to sulfate and comparing the amount of acidity to the total
buffering capacity of the rock. The test results can be used to determine the potential for metal
leaching by computer analysis.
Other test methods are commonly used for conducting mining and mineral processing waste
leachability analyses. These tests, however, may or may not be appropriate since they are
conducted under saturated conditions (i.e., they do not measure the oxidation potential of sulfur
bearing minerals). The primary RCRAtest used to characterize waste samples is the Toxicity
Characteristic Leaching Procedure (TCLP). Three potential alternatives to the TCLP exist: the
Synthetic Precipitation Leaching Procedure (SPLP), which some states reportedly use; the Multiple
Extraction Procedure (MEP); and California's Waste Extraction Test (WET). Some states use other
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7-6 Chapter 7: Sampling & Analysis of Impacted Areas
methods; for example, Nevada uses the Meteoric Waste Mobility Test (MWMT) to assess the
likelihood of acid generation overtime. Additional information on the test methods discussed above
can be found at the following:
TCLP - httD://www.epa.qov/epaoswer/hazwaste/test/131 l.pdf:
SPLC - httD://www.epa.qov.80/epaoswer/hazwaste/test/1313.pdf:
MEP - http://www.epa.aov.80/epaoswer/hazwaste/test/1320.pdf:
WET - can be found in the California Code of Regulations, Title 22, Chapter 11,
Articles).
7.3.7 Selecting Analytical Methods
Many methods are available for the analysis of mining and mineral processing waste samples. The
Guide to Environmental Analytical Method^ provides information on analytical methods, such as
method detection limits, sample preservation requirements, field sample volumes required, and
holding times. Examples of general analytical methods include total constituent analysis, acid
digestion, X-ray fluorescence (XRF), and gas chromatography-mass spectroscopy (GCMS). Most
of the methods mentioned in the Guide are included in SW- 8463 EPA's test methods for evaluating
solid waste. EPA's waste characterization data on Superfupd mining and mineral processing sites4
provides examples of sampling and analysis methods already used at selected mining and mineral
processing sites. Exhibit 7-1 shows examples of analysis methods that have been chosen in the
past.
Exhibit 7-1
Sampling and Analysis Methods
Method
Wet Chemistry/XRF
Acid Digestion
XRF/ (Inductively Coupled Plasma
Emission
Spectroscopy (ICP))
Mining and Mineral Processing Site/Sample Matrix
Cherokee County, KS. Galena Subsite: waste samples analyzed for
metals ,
Cotter Uranium Mill, Canon City, CO: soil and sedment samples
Tex Tin Corporation, Texas City, TX: samples analyzed for lead, iron,
nickel and tin initially using XRF did not show presence of metals;
samples were then extracted with nitric acid and analyzed with ICP to
confirm XRF results. •
X-ray Fluorescence (XRF) Analytical Method
X-ray Fluorescence (XRF) is a non-destructive analytical technique used to determine the elemental
composition of a sample. XRF measures the X-ray fluorescence coming from the inner electron
shells of the atom. This is a systematic method and each element has its own "fingerprint". The
XRF method measures the radiation coming direct from atoms and not from chemical compounds.
The X-ray spectrum generated in the sample will tell which elements are present (wavelength of
X-rays) and the amount of these elements (intensity of X-ray wavelength).
XRF is being applied to sites to increase the representativeness of sampling, expedite the activity
by performing real-time data analysis to support decision making, and decrease both the time and
2Wagner, R.E., W. Kotas, and G.A. Yogis, 1992. Guide to Environmental Analytical Methods
3U.S. Envirormental Protection Agency (EPA), 1986. Test Methods for Evaluating Solid Waste (SW-846): Physical .
Chemical Methods.
4U.S. Envirormental Protection Agency, 1991. Mining Siteson the National Priorities List: Waste Characterization Data.
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Chapter 7: Sampling & Analysis of Impacted Areas 7-7
cost of these activities. Because of this, XRF is being considered at many abandoned mining sites.
As with any method, application of the XRF method depends on the project objectives and
associated DQOs. Representativeness and;completenlss';are two of the major advantages of
using XRF. On-site, real time chemical analysis can document representativeness and allows
critical samples to be collected and analyzed, which typically ensures completeness.
Media that are commonly appropriate for XRF analysis include soils, in particular, but essentially all
solids, as well as liquefied solids, such as sludges and slurries. Detection limits extend from mg/kg
(parts per million) to the 100 percent range for mobile XRF instruments and from tens to hundreds
of mg/kg to 100 percent for field portable instruments.
Field-portable instruments, usually weighing less than 20 pounds (including batteries), can be
carried to the sample location. Mobile instruments, however, require line voltage, and are usually
placed within a specific building or van near or at the site to generate quality data. Decisbns
concerning the attainment of an action level can be made quickly at the site. Coupling the use of a
field portable and moble laboratory instruments at a site would allow for abnost immediate
decisions to be made concerning an action level in the field that can be confirmed by the mobile
laboratory. Typically, a representative composite sample from the site area under cleanup action is
sent to the laboratory for final documentation of the clean up level.
In most instances, an initial set of site samples is required for calibration purposes. The samples
should cover the matrices and concentration range of elements of concern as determined by a total
metals analysis by a laboratory. The samples should be prepared by the laboratory using the same
protocol that will be used with the XRF at the site.
At the sample location, a field-portable instrument is equipped with a probe that allows considerable
flexibility in how a sample is presented to the source. The source may be pressed against the
media of interest (soils, tailings, walls, etc.) or a sample cup of material (soil, slurry, sludge, etc.)
can be placed on top of the source. Samples may be sieved or pulverized but sample preparatbn
is typically minimal. Field-portable instruments are versatile but have the highest detection limits of
the three types of instruments. Typical detection limits with little to no sample preparation are ri the
100 mg/kg range, depending on sample matrix. For mobile instruments, sample preparation is part
of the analytical schedule and includes sieving and pulverizing. A typical detection limit will range
from 5 to 30 mg/kg, depending on the sample matrix. Sample preparation and particle size
variance are major potential sources of error.
High expectations and indiscriminate use of the instruments outside the design limits of the unit has
sometimes led to discouragement in the application of field-portable XRF instruments. Although a
particularly low detection limit may not be achievable in some cases, the instrumentation will usually
determine hot spot areas, document that representative sampling has been accomplished, and
determine that an action-level for a particular element has been reached in real time at the location.
Confirmatory analyses should be performed by a fixed analytical laboratory.
The total extent of XRF application to abandoned mining sites is undoubtedly larger than the
published accounts of such applications. Documented use of field-portable XRF instruments start in
1985 with the Smuggler Mountain Site near Aspen, Colorado.5 The instrument was used to
determine action-level boundaries of 1,000 mg/kg lead and 10 mg/kg cadmium in soils and mine
waste. The same site was used for the evaluation of a prototype field-portable XRF instrument
" Mernitz, S., Olsen, R., and Staible, T., 1985, Use of Portable X-Ray Analyzer and Geostatistical Methods to Detect and
Evaluate Hazardous Materials in Mine/Mill Tailings: Proc. Natl. Ccnf. on Management of Uncontrolled Hazardous Waste Sites,
Washington, DC, pp. 107-11=1.
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7-8 Chapter 7: Sampling & Analysis of Impacted Areas
specifically for hazardous waste screening6. Field-portable instruments have also been used at the
California Guich Site, Leadville, Colorado; Silver Bow Creek and other sites near Butte, Montana;
Bunker Hill Site, near Kellogg, Idaho; and the Cherokee County Site, Tri-State Mining District,
Kansas for screening purposes during site characterization. A field-portable instrument has been
used to screen a large area (21 square miles) to select large, homogeneous volumes of heavily
contaminated soils for treatablity studies and for Site Comparison Samples at the Bunker Hill Site.7
Portability and "real-time" basis data were necessary prerequisites. A mobile XRF instrument was
used for multi-element analysis of lead, arsenic, chromium, and copper in soils.8 Detection limits
with the x-ray-tube-source and Si(Li) detector were as low as 10 mg/kg. The data were used to
map the extent of contamination wjthin a superfund site. Detection limits for field-portable
instruments are not low enough to determine cadmium concentrations as low as 10 mg/kg in some
areas/matrices, but zinc was found to'be a good surrogate indicator element for cadmium in
Cherokee County, Kansas.
6 Raab G A Cardenas, D., Simon, S.J., and Eccles, L.A., 1987, Evaluation of a Prototype Field-Portable X-Ray
Fluorescence System for Hazardous Waste Screening: EMSL. EPA 600/4-87/021, U.s: Environmental Protection Agency,
Washington. DC. 33 p.
7 Barich, III, J.J.. Jones, R.R., Raab, G.A..and Pasmore, J.R., 1988. The Application of X-Ray Florescence Technology
in the Creation of Site Comparison Samples and in the Design of Hazardous Waste Treatment Studes: First Intl. Symposium, Field
Screening Methods for Hazardous Waste Site Investigations, EMSL Las Vegas, NV, pp. 75-80.
8 Perl's. R..and Chapin, M., 1988, LJDW Level XRF Screening Analysis of Hazardous Waste Stes: Frst Intl. Symposium,
Field Screening Methods for Hazardous Waste Site Investigatbns, EMSL, Las Vegas, NV, p. 81-84.
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Chapters
Scoping and Conducting Ecological and Human Health Risk
Assessments At Superfund Mine Waste Sites
8.1 Introduction.
The purpose of this chapter is to highlight some of the unique issues related to risk
assessments at abandoned mine waste sites and to provide some guidance to help address
these issues. Baseline risk assessments for site investigations provide a basis for risk
management decisions. Although risk management decisions help determine the scope of the
risk assessment, they should not influence the analytical process utilized in the evaluation. For
example, scientific elements of the dose-response evaluation will remain consistent throughout
all risk assessment activities. Risk assessments are also conducted to support removal actions
that reduce excess risks to health to acceptable levels. This chapter furnishes Site managers
and other federal, state, and local authorities with a summary of key issues relevant to mine
waste site risk assessments as well as a compJation of references to other helpful resources.
In some cases, cleanup activities can be implemented without conducting a baseline risk
assessment.
8.2 Supporting Guidance Documents.
EPA Risk Assessment Guidance for Superfund (RAGS), including Volume 1 parts A1, B2 and C3
D4, and a supplemental volume5, provide a broad, conceptual framework for conducting human
health risk assessments at CERCLA sites. These concepts, while originally developed to
address risk assessment issues during CERCLA action, are appropriate to consider in
evaluating risk at non-CERCLA sites. Guidance for conducting ecological risk assessments
may be found in the Ecobgical Risk Assessment Guidance for Superfund6 (ERAGS), the EPA
Guidelines for Ecological Risk Assessment7, the field and laboratory reference guide8, and in
Appendix F of this document. EPA's Office of Emergency and Remedial Response supplies
copies of the ECO Update intermittent bulletin series of supplemental ecological risk
assessment guidance on specific technical and procedural issues. General EPA guidance
1 U.S. Environmental Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfund: Volume 1 - Human Health
Evaluation Manual, Part A: Baseine Risk Assessment. EPA/540/1-89/002.
! U.S. Environmental Protection Agency (EPA). 1991. Risk Assessment Guidance for Superfund: Volume 1 - Human Health
Evaluation Manual, PaftB: Development of Risk-based Preliminary Remediation Goals. EPA/540/R-92/003.
' U.S. Environmental Protection Agency (EPA). 1991. Risk Assessment Guidance for Superfund: Volume 1 - Human Health
Evaluation Manual, Part C: Risk Evaluation of Remedial Alternatives. EPA/540/R-92/004.
' U.S. Environmental Protection Agency (EPA). 1998. Risk Assessment Guidance for Superfund: Volume I Human Health
Evaluation Manual, PartD, Standardized Planning, Reporting, and Review of Superfund Risk Assessments. Office of Emergency
and Remedial Response, Publication 9285.7-01 D
* U.S. Environmental Protection Agency (EPA). 1991. Risk Assessment Guidance for Superfund: Volume 1 - Human Health
Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors. OSWER directive 9285.6-03.
"U.S. Environmental Protection Agency(EPA). 1997.Process fordesigning and conducting ecological risk assessments.
EPA/540-R-97-006, June 5, 1997.
? U.S. Environmental Protection Agency (EPA). 1998. Guidelines for Ecological Risk Assessment. EPA/630/R-95/003F.
" U.S. Environmental Protection Agency (EPA). 1989. Ecological Assessment of Hazardous Waste Sites: A Field and
Laboratory Reference. EPA/600/3-89/013.
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8-2 Chapter 8: Scoping and Conducting Risk Assessment
documents that address risk-related issues include Superfund Accelerated Cleanup Model
(SACM) information9, guidance addressing data useability in risk assessments10, data quality
objectives11, and risk characterization12.
Other guidance specific to particular issues or regions may be obtained through regional
offices. Contact the regional EPA office associated with a given site to determine if regional
guidance is available, as well as to determine the appropriateness and applicability of utilizing
guidance documents from other regions on particular issues. For example, OSHA and related
work place regulations (e.g., ACGIH, NIOSH) do not apply to environmental contamination,
exposure to non-workers, or to workers outside of their controlled job setting. EPA and OSHA
have an MOU on this subject and some regions have guidance for handling joint occupational
and environmental exposures and resulting risks. Reference and guidance documents are also
available from other federal agencies (e.g., USGS)and from varbus state agencies (e.g.,
California Environmental Protection Agency).
Contact information and electronic versions of some EPA publications are available online
through the world wide web at http://www.epa.gov and new pub&cations are available from the
U.S. EPA Office of Research and Development at http://www.epa.gov/ORD/whatsnew.htm.
8.3 Overview of Mine Waste Site Risk Assessment Features
Several features of mine waste sites may be unique among hazardous waste sites and should
receive consideration in the baseline risk assessment. This section addresses issues which are
relevant to both ecological and human health risk assessment.
8.3.1 Site Characteristics
Physical Features. Features prevalent at many mine waste sites that may influence the
approaches taken in the risk assessment include the size of the site, current and future land
uses, the number of contaminants present, media contaminated, and the vertical and horizontal
extent of contamination. Mine waste sites may occupy areas comparatively larger than those of
other hazardous waste sites. Two examples of influences on the risk assessment are: (1) A
large area is more likely to include greater portions of a particular terrestrial organism's home
range and to possibly include more than one type of ecosystem and (2) Some former mine sites
are current residential areas while others are very remote and have little likelihood of becomng
residential.
Contaminant Distribution. Contamination is commonly ubiquitous across mine waste sites
and includes a large volume of contaminants. Such widespread contamination often requires
multiple pathway exposure evaluations in the risk assessment. It may be helpful to identify and
focus on contaminants and/or exposure pathways that will drive the risk assessment; however,
* U.S. Envirormental ProtecBon Agency (EPA). 1994. Risk Assessment Tools for the Supetfund Accelerated Cleanup Model.
Office of Solid Waste and Emergency Response. November. PB94963226.
" U.S. Environmental Protection Agency (EPA). 1992. Guidance for Data Useability in Risk Assessment, Parts A and B. Office
of Solid Waste and Emergency Ftesponse. Drective 9285.7-09A&B. (PB92963356 and PB92963362.)
" U.S. Environmental Protection Agency (EPA). 1993. Data Quality Objectives Process for Superfund Interim Final Guidance.
EPA/540/R-93/071.
11 U.S. Environmental Protection Agency (EPA). 1995. Memoranda from Carol Browner regarding EPA Risk Characterization
Program/EPA Risk Characterizatbn Policy and Guidance. Office of the Administrator. March 21.
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Chapter 8: Scoping and Conducting Risk Assessments 8-3
each contaminant of concern must be addressed and associated risks must be characterized to
ensure that planned cleanup activities will be comprehensive. In some cases, this process may
involve a screening-level risk assessment which precedes'a more in-depth risk assessment.
8.3.2 Comprehensive Risk Assessment Considerations
Several issues are comprehensive because they are important in both ecological and human
health risk assessments. This section discusses three such important issues: 1) Background
Contaminant Concentrations, 2) Exposure Pathways, and 3) Bioavailability.
Defining Background. Naturally high background concentrations of metals are an important
consideration at mine sites. Chapter 7 discusses background sampling in the initial sampling
and analysis plan; the EPA Data Useabifity Guidance, cited earlier in this chapter, may also be
consulted for assistance with planning a background sampfing design. To ensure that
appropriate "reference area" locations are chosen for background sampling, risk assessors
must consider both natural and anthropogenic contributors. A background sampling location
should usually be upwind and upstream of the site, and must have soi characteristics and
related properties similar to those at the site. If several different types of soil or habitats are
present at the site, more than one set of background data may need to be gathered to ensure
that appropriate comparisons are made. A nearby watershed, unimpacted by mining, may
provide an opportunity to collect background samples.
Natural background concentrations of metals in mining areas may occasionally be elevated
above risk-based values or regulatory criteria and standards. Risk-based values are those
concentrations at or above which an unacceptable human health or ecological effect may occur.
Regulatory levels, including applicable or relevant and appropriate requirements (ARARs,
discussed in Chapter 7) may or may not be risk-based values. If naturally occurring
background concentrations exceed risk-based or regulatory values, the risk assessment may
separately present risks caused by site contributions from natural background levels. The risk
assessment should always present cumulative risk estimates. This enables risk managers to
gain perspective and make better cleanup decisions.
Anthropogenic contributors to a background sampling site should be similar to those connected
with the mine waste site. Both site samples and background samples should be representative
of the areas under consideratbn. For example, if a busy highway runs through a proposed
background sampling area, the same or a similar highway should be associated with the mine
waste site to account for leaded gasoline depositbn. Locations which reflect obvious
contributions of human activities, such as roadsides, drainage ditches, storm sewers or the like,
could be judged as inappropriate for collecting background samples. These areas may reflect'
secondary sources of contamination and not be representative of the greater area under
consideration. In rare cases, a roadway contaminated during the transport of mining materials
may be an area of concern. It is important that the intended applications of the background
data in the risk assessment are determined early in the process to ensure that an adequate
number of samples over an appropriate area and in a relevant pattern are collected to allow, as
applicable, for spatially relevant and statistically significant results. Usually, per ERAGS
Appendix D (Statistical Considerations), a 1-taii t-test is adequate to compare background with
site concentrations, provided that independent representative samples from proper locations
are evaluated. EPA guidance on the determination of inorganic content in soils and
sediments13 is also available.
"U.S. Environmental Protection Agency (EPA). 1995. Engineering Forum Issue: Determination of Background Concentrations
of Inorganics in Soils and Sediments at Hazardous Waste Sites. Offce of Solid Waste and Emergency Response December
EPA/540/5-96/500. . '
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•4 Chapter 8: Scoping and Conducting Risk Assessment
Exposure Pathways and Sources. Risk assessments at mine waste sites commonly require
evaluation of exposures from multiple sources and exposure via multiple pathways. Multiple
pathway assessments for terrestrial ecological receptors may include surface water mgsstion
incidental ingestion of soil, or ingestion of contaminants taken up by plants. For human health
assessments, multiple exposure pathways may include dermal contact with soil or water,
incidental ingestion of soil or dust, inhalation of dust, and ingestion of ground or surface water.
Multiple contaminant sources, such as nearby off-site tailings piles and roadways constructed of
slag or waste rock may also contribute to risks incurred by mobile populations with large home
ranges as well as human beings that live and play in various areas of the site. Concurrent
occupational and residential exposures are particularly relevant for those contaminants that are
encountered both on the job and at home. Exposure sources may also include exposures from
lead-based household paints and occupational metal exposures. Such analyses may later
support multi-media risk reduction options strategies. EPA recommends the development and
use of a conceptual site model (as described in RAGS, Section 3.6) to link releases from
contaminant sources to environmental media which wil be contacted by potential receptors
under current and future land-use scenarios.
Bioavaliability. When estimating the internal dose of a given contaminant, several factors are
evaluated- source exposure concentration, intake rate, and the fraction of contaminant which is
bioloqically available to that organism. Considerations of the particle size and mineralogy, the
oxidative state of the metal, physical accessibility (e.g., whether or not it is encased by another
compound which is not able to be broken down by an organism's digestive system) can modify
an organism's internal dose. Data for assessing bioavailability may come from animal testing or
from validated laboratory (in vitro) procedures. Only tests with biological systems can provide
bioavaiiabilfty values. Other non-animal experimental procedures may provide information
regarding "bioaccessibBity," or the potential for uptake based on physical or chemical features
TCLP EP-TOX chemical equilibrium computer models and other non-animal tests provide little
useful information about bioavailability in (iving systems. In 1997, industry-initiated research
was begun to evaluate the use of in vitro methods; however, scientific peer review and
validation have not been completed at this writing. For lead exposure estimates, EPA s
Technical Review Workgroup for Lead (TRW) can provide the latest estimates of bioavailabilty.
With respect to human exposure, bioavailability can be defined as "absolute" or "relative". It is
important for the bioavailability units of measure to properly correspond to the toxicity units of
measure. Consult your regional risk assessor for a complete explanation of these terms and
how they affect the risk assessment.
8.4 Ecological Risk Assessment
Understanding the ecological risk posed by a mine site is critical to making sound cleanup
decisions For a CERCLA cleanup Sectjon 300.430(e)(2)(l)(G) of the NCP states that during
Remedial Investigations and Feasibility Studies, "environmental evaluations shall be performed
to assess threats to the environment, especially sensitive habitats and critical habitats of
species protected under the Endangered Species Act." In addition, as described in Chapter 7,
numerous federal and state statutes and regulations concerning environmental protection
contain potential ARARs for Superfund sites.
Mine sites are unique from other sites in ways that can influence the size, scope, and detail to
adequately characterize ecological risks. These sites can cover large areas and often affect
large portions of eco-regions. In historic mining districts mine site impacts can contnbute to
degraded environmental conditions throughout a watershed. Moreover, they may be located in
more remote areas, on federally owned land that is otherwise relatively pristine. Guidance on
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Chapters: Scoping and Conducting Risk Assessments 8-5
the role of natural resource trustees is particularly applicable for mine waste sites14. Mine waste
sites are contaminated primariy with heavy metals and may also be impacted by operational
contaminants including cyanide, acids, and^C.Bs. These sjtes may to be located in areas with
soil and waters containing high background levels of metals and low pH that can complicate
interpretation of soil, sediment, and surface water sampling results. Furthermore, cleanup
options tend to be limited by the magnitude of problems and physical alterations to the land-
scape.
The following sections discuss ecological risk assessment issues associated with mine waste
site investigations. For a more complete discussion of the ecological risk assessment process,
and some suggestions regarding methods for approaching specific situations, consult the
ERAGS, as well as Appendix F of this, handbook. Helpful examples of ecological risk
assessments prepared for large mine sites include: Bunker Hill in Idaho, Kennecott (terrestrial)
in Utah, Sulphur Bank Mercury in California, Carson River Mercury in Nevada, and California
Gulch (aquatic) in Colorado.
8.4.11dentification of Potential Chemical and Physical Stressors
The major threat to the environment from mine sites is heavy metal contamination, including
"acid mine drainage". See also Chapters 2 and 3 for an overview of mine site operations and a
discussion of mine waste site activities that contribute to ecological and human health risk.
Physical habitat alteration may also adversely affect environmental receptors. Sections 8.4.3
and 8.4.4 discuss some of these alterations and potential impacts. Additionally, Section 8.3.2
discusses background concentrations and is relevant to ecological as wey as human health risk
assessment. Background concentrations may be used in the determination of contaminants of
potential concern for a site. Site contaminant concentrations may also be compared to toxicity-
based reference values.
Some metals commonly found at mine waste sites such as zinc, iron, copper, and manganese
are essentialmicronutrients for both wildlife and humans; they can be, however, toxic at higher
levels. Bio-accumulation of metals presents greater problems for fish and wildlife at higher
trophic levels, but this usually only occurs with organic metals such as methyl mercury.
8.4.2 Problem Formulation
Ecological risk assessments require clear definitions of the receptors and transfer pathways
being assessed. Identifying nnpacts common to mine waste sites and placing them into a
Conceptual Site Model facilitates a focused and efficient ecological risk assessment. For each
functional unit, relevant assessment endpoints must consider spatial and temporal issues.
Spatial Issues. The large size and potential ecological complexity of a mine waste site may
require assessment of several functional ecosystems. Both the relative and absolute
magnitude of the contaminated area and of smaller specific areas that are critical to site
ecosystems should be examined. The impacts of small scale contamination on highly valued
habitats (e.g., tailing piles in wetlands or streams) and of broad scale contamination on other-
habitats should each be evaluated. Key elements associated with the spatial scale include
multiple types of releases (e.g., tailings, drainage, smelting dross and emissions) and
associated transport mechanisms. Home ranges are a critical spatial concern. Different types
of home ranges (e.g., hunting areas, roaming areas) may be considered based on the way a
given organism is likely to encounter mine waste contaminants (e.g., food chain exposure or
" U.S. Environmental Protection Agency (EPA). 1992. ECO Update: The Role cf Natural Resource Trustees in the Superfund
Process. Volume 1. Number 3. Office of Emergency and Remedial Responses. PB92963369.
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8-6 Chapter 8: Scoping and Conducting Risk Assessment
incidental soil hgestion). Selected home ranges must be compared with identified
contaminated areas.
Temporal Issues. Ecological parameters are controlled by temporal factors. Seasonal events
such as snowmelt, runoff, and swollen creeks and rivers can serve as major energy inputs that
mobilize contaminants and contribute to higher levels of transported solids. Low flow, high
temperature periods should be evaluated as times of likely contaminant-motivated stress to
organisms, which may result in increases to organism metabolism and contaminant concen-
trations. Receptor foraging behaviors can vary during migration and spawning times. The
analysis should consider receptor behaviors and life stages which may adversely enhance
toxicity. For example, salmon eggs are more sensitive to toxicity from metais than adult fish.
Endpoints. Endpoint selection will direct planning of the ecological risk assessment and help
place results in context. Identification of potential endpoints may be initiated with a description
of the general functional groups in the ecosystem. Environmental media and exposure routes
of mine waste contaminants should be identified during preparation of the Conceptual Site
Model. Toxicological modes of action for site-specific contaminants of concern should also be
considered. Based on this information and the spatial and temporal issues identified above,
species and processes, within identified functional groups, that appear to be most valued, most
sensitive, or that meet other site-related criteria (e.g., organisms that are hunted or fished,
threatened or endangered raptors) can be selected for evaluation in the risk assessment. Final
selection species and process assessment endpoints and measurement endpoints involves
additional considerations.
Careful selection of "assessment endpoints" will help define subsequent supporting
measurements. Each assessment endpoint will associate with one or more measurement
endpoints to facilitate evaluation of exposure and risk. Choice of endpoints should be reflective
of the complexity (e.g., organism interdependence) and diversity (e.g., variety of plants, animal
and aquatic life) of the ecosystem. Risks to threatened and endangered species may be
assessed through their incorporation into the Conceptual Site Model. Other decisions which
should be made prior to data collection include definition of data objectives, explicit measure-
ment selection, establishment of acceptable levels of uncertainty, and data quality control and
analysis procedures. Since background metals concentrations at mine waste sites tend to be
high, it is important to define a "significant risk level".
8.4.3 Characterization of Ecological Effects
Terrestrial Impacts and Risks. At some sites (e.g., Bunker Hill in Idaho), air transport of
particulate matter from smelting operations and acid emissions (SO2, NO2 derived from H2SO4
and HNO3) resulted in widespread contamination of surrounding soils, vegetation loss and
stress, via acid rain and phytotoxicity, over hundreds or thousands of acnes. Soils with high
residual metal levels may not support native vegetation. Sites also may have large areas of
degraded or lost vegetation following massive physical alterations of terrain and subsequent
erosion. Vegetation coverage may serve as one measurement endpoint when evaluating an
area's ability to support herbivorous terrestrial organisms. Vegetative loss may itself serve as
an assessment endpoint for evaluating the overall ecological state of the site with soil metal
concentration as one of its supporting measurement endpoints. Increased levels of zinc in soils
can cause a decrease in microbial levels and in lichen growth. Decreased lichen growth can
indicate the soil's ability to sustain vegetation. Risk to other terrestrial-linked receptors should
be taken into account, even if the receptor's home range extends beyond the site boundaries.
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Chapter 8: Scoping and Conducting Risk Assessments 8-7
Aquatic Impacts and Risks. Extensive degradation of aquatic ecosystems has occurred at
many mine waste sites. Degradation of riparian vegetation has resulted in bank destabilization,
erosion and sedimentation of water bodies* Run-off ffifm failings piles often lowers the pH of
surface waters and increases levels of metals in sedirn^ntSiand the water column. Metal
precipitates are often formed from acid mine drainage which adsorb to sediments and disrupt
the benthic community. Run-off events from snow melt and storms can result in pulses of acids
and toxic substances at critical life stages for resident fish and invertebrates. High acidity from
mine acid drainage or storm water run-off at mine waste sites results in mobilization of metals in
water, potentially causing detrimental effects to the aquatic community including fish kills. If fish
tissue samples are to be used as a measurement, an adequate supply of fish for sampling
should be verified at the time of assembling the sampling and analysis plan. At the older mine
waste sites, tailings sometimes were dumped directly into surface waters or washed into
surface waters in the initial years of mining operations. The concentration of metals in waste
piles tends to be higher at older sites because the older methods of ore processing were not as
efficient. At many mine waste sites, it is difficult to identify the key sources and events which
cause continued contaminatbn of surface waters. Other aquatic issues to consider include
effects on benthic invertebrates and related impacts via the food chain, food chain exposures to
aquatic birds and mammals, bioavailability of contaminants in sediments, chemical, and
physical properties of the water that influence contaminant toxicity.
8.5 Human Health Risk Assessment
The following section discuss human health risk assessment issues associated with mine waste
sites. The intent of this section is to highlight issues not specifically addressed in RAGS and
other guidance.
8.5.1 Contaminants of Potential Concern
Human health risk assessments at mine waste sites focus primarily on issues addressing risks
to humans from heavy metals and process chemicals. Heavy metals such as lead, zinc,
copper, arsenic, cadmium and mercury as well as radionuclides, PCBs, and cyanide have been
identified in soils near mine waste sites. Contamination may occur via wind blown dust, the use
of mine wastes for landscaping, road building or foundations for home building, transport by
surface waters or spillage during mining activities. Comparison of measured contaminant
concentrations to undisturbed background concentrations and preliminary remediation goals
may help to identify site-specific contaminants of potential concern. Some EPA regional offices
have developed fists of preliminary remediation goals based on default assumptions for
screening purposes. Contact your regional risk assessor for more information. There is also a
soil screening levels guidance document available15.
Lead. Up to the current time, lead has been the an important contaminant of concern at
Superfund mine waste sites associated with residential use. EPA guidance16 recommends the
cleanup goal of a soil lead concentration such that a child would have an estimated risk of no
more than 5% of exceeding a bbod lead concentration of 10 g/dl. In August 1998, EPA
issued clarification to the 1994 Revised Interim Soil Lead Guidance for CERCLA sites and
RCRA Corrective Action Facilities. The full text can be found at the following web page:
- http://www.epa.gov/epaoswer/hazwaste/ca/index.htm#p&g.
"U.S. Environmental Protection Agency (EPA). 1994. Soil Screening Guidance. Office of Solid Waste and Emergency
Response. EPA/540/R-94/101.
'" U.S. Environmental Protection Agency (EPA). 1998. Clarification to the 1994 Revised Interim Soil Lead Guidance for
CERCLA Sites and RCRA Corrective Action Facilities (a.k.a. "The Lead Directive"). Office of Solid Waste and Emergency
Response. August. Directive* 9200.4-27. EPA/540/F-96/030.
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8-8 Chapter 8: Scoping and Conducting Risk Assessment
The July 14, 1994 OSWER directive (The Lead Directive) indicates that a level of 400 ppm lead
in soil be used as a level of contamination above which there may be enough concern to
warrant site-specific study of risks. The EPA utilizes the Integrated Exposure Uptake Biokinetic
(IEUBK) Model17 to predict blood lead concentrations in children chronically (longer than 90
days) exposed to lead contaminated sources including soil, food, water, dust, air and drinking
water, and to develop agency guidance. The IEUBK Model is discussed in the following section
on Exposure Assessment, 9.5.2.
EPA has a Technical Review Workgroup (TRW) with expertise in the field of lead risk
assessment. The TRW is comprised of senior scientists from multiple EPA regions and
program offices (e.g., OSWER, NCEA and OPPTS). The TRW is supported by OSWER and
its work is directed by TRW members. The TRW can be contacted through regional risk
assessors and provides support for the use of the IEUBK model as well as assistance in other
lead risk assessment issues.
In addition to the TRW, EPA has established the Lead Site Workgroup (LSW), composed of
risk managers and risk assessors from the Regions and Headquarters, as a resource to
develop agency guidance on risk management issues, and to provide the Regions with site
specific consultations18. Through the efforts of the LSW, the Clarification to the 1994 Revised
Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities was
issued. The Lead Site Consultation Group (LSCG), composed of Division Directors and senior
managers from Regions and Headquarters provides general direction to the LSW. The LSW
and the LSCG can be contacted through regional Mine Sites Coordinators or through regional
OSWER contact persons who address risk issues.
Guidelines regarding lead-based paint hazards in housing are available from HUD19. When
evaluating indoor dust for its potential to contribute to lead exposure it is important to evaluate
the contribution of lead based paint. It is particularly important to evaluate the presence of
lead-based paint in older communities. The LSW is preparing risk management position
papers which also provide guidance for the evaluation of soil and dust exposures when lead-
based paint may be present.
Other Metals. Not all mine waste sites have lead as the primary contaminant of potential
concern. It is not unusual for several metal contaminants to be present. Arsenic, cadmium,
mercury and antimony may also be present. Although not a metal, cyanide may be a
contaminant due to its use as a process chemical.
Radionuclides. Examples of radionuclides and their decay products that may be present at
mine waste sites include thorium, radium, radon, and uranium. The risk assessment should not
include the risk to background levels of radiatbn. Only the incremental risk to the contaminants
must be considered. Further information for determining PRGs for radionuclides is provided in
RAGS part B.
" U.S. Envirormental Protecion Agency (EPA). 1994. Guidance Manual for the IEUBK Model for Lead in Children. Office of
Solid Waste and Emergency Response, Washington, DC. EPA/540/R-93/081.
" U.S. Environmental Protection Agency (EPA). 1996. Memorandum from Stephen D. Luftig regarding Administrative Reforms
for Lead Risk Assessment Office of Solid Waste and Emergency Response. April 17.
" U.S. Department of Housing and Urban Development (HUD). 1995. Guidelines for the Evaluation and Control of Lead-Based
Paint Hazards in Housing. June.
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Chapter 8: Scoping and Conducting Risk Assessments 8-9
Organics. Organics may include VOCs (e.g., TCE), SVOCs (e.g., PAHs), PCBs, and fuel oil
constituents. Volatile organics can introduce the inhalation pathway via exposures directly on
site or from ground water transport to shower water supply. Individuals may be exposed to
organics via ingestion or dermal contacffWifh contamin||ted;water or soil. Although organic
contaminants are not usually dominant at mine waste sites, when they are present they may
introduce significant risks that must be considered in the assessment. PCBs and asbestos may
also be present at abandoned facilities.
8.5.2 Exposure Assessment
This section discusses some unique.issues associated with assessing exposures to humans at
mine waste sites. Exposure pathways and sources include inhalation of fugitive dust, soil
ingestion, dermal contact with soil, indirect exposure through plant and animal uptake (and
subsequent consumption by humans or animals), and ingestion of and dermal contact with
contaminated ground water. Risk assessors may find useful information for assessing indirect
exposures in RCRA guidance20. Mining pits, shafts, and boreholes may provide conduits
through which groundwater contaminants migrate from shallow to deep aquifers that may
contaminate drinking water. Recreational surface waters used for fishing and swimming can be
contaminated from storm water run-off, leaching from waste piles and ground water to surface
water migration routes. Plumbing, occupational exposure, and home hobbies should also be
assessed as potential sources of lead in evaluating overall community exposure potential, as
well as the individual level.
Measurement of Indoor Dust and Outdoor Soil and Dust. Much of the exposure to site-
related metals may occur from contact with indoor dust, and outdoor soil and dust. In sites with
current residential use, site specific characterization of contaminants in indoor dust may provide
valuable information regarding the sources of contamination and significantly influence remedial
or removal activities. For example, the presence of lead-based paint, if determined to a source
of contaminatbn, could affect remedial or removal activities.
The Integrated Exposure Uptake Biokinetic Model (IEUBK). The U.S.EPA uses the 1EUBK
model to predict childhood blood lead concentrations at lead contaminated sites. The IEUBK
uses a predictive, integrated, multi-source and multi-exposure route approach to estmate the
probability of exceeding user-chosen blood lead concentrations. The model results assist the
site manager in developing final cleanup goals which are protective of the typical child. The
model provides soil lead concentrations that represent the 95% upper confidence limit on the
mean soil lead concentration goal. The IEUBK model should not be used for predicting blood
lead concentrations in populations other than children who may be chronically (greater than 90
days) exposed to lead contamination. The TRW (or regional risk assessor) should be
consulted to ensure the consistent and appropriate use of the IEUBK model. The LSW has
prepared risk management position papers to provide guidance to ensure consistent
management at mine waste sites.
The 400 ppm level of concern, presented in the Lead Directive, was derived using the IEUBK
model in conjunction with a set of default assumptions. Site-specific data or default parameters
under appropriate circumstances may be substituted. Contact the TRW (or regional risk
assessor) for assistance.
:" U.S. Environmental Protection Agency (EPA). 1994. Exposure Assessment Guidance for RCRA Hazardous Waste
Combustion Facilities, Draft. April EPA/530/R-94/021.
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8-10 Chapter 8: Scoping and Conducting Risk Assessment
Estimating Adult Exposures. A methodology for assessing adult lead exposures is
available21. In this methodology, soB/dust exposures to the adult female are evaluated and the
blood lead concentration in the fetus of the pregnant adult female are estimated.
8.5.3 Toxicity Assessment
Because mine waste sites can be very large and contaminant concentrations heterogeneous,
several different exposure scenarios may be indicated. Based on current or proposed site use,
it may be appropriate to develop exposure point concentrations which permit evaluation of
acute as well as chronic toxicity. In EPA Superfund risk assessments both cancer and non-
cancer health effects should be evaluated for all contaminants as well as the risks of exposures
to mixtures. Guidance is available for.applying toxicity values from EPA's Integrated Risk
Information System (IRIS)22 on the World Wide Web at the following address:
http://www.epa.gov/iris/.
3.5.4 Health Studies
In addition to baseline risk assessment activities or removal risk assessment activities, mine
waste sites may have coinciding epidemiotogic or human health studies. Such studies do not
replace the need for risk assessment, and are only useful where the data provide sufficient
resolution for documenting both the presence and absence of exposure or adverse health.
Results of human health studies may be used in developing a site cleanup strategy responsive
to the community's health protection needs. Occasionally, the results of community health
studies may reveal an imminent health threat and trigger a removal action. Health studies have
been conducted by the PRP, the Agency for Toxic Substances and Disease Registry (ATSDR),
local health districts, and state health departments.
If a related health study is to be conducted, EPA should be involved in both the design of the
study and the final interpretation of study results. During the scoping of the health study plan,
the community's ability to implement a health program should be taken into consideration. All
technical (but not managerial) analyses associated with the health study should generally
undergo peer review. In lead risk assessments, structural equation modeling of the health
study results may help distinguish the contributions of different sources of human exposure.
However, structural equation modeling is resource and time intensive; it contains variability and
uncertainty, and potential benefits should be carefully weighed against the cost before
proceeding. Structural equation modeling may also discriminate among various activities which
influence human activity patterns and therefore exposures. For example, health intervention
and education, or even an increased awareness of contamination, commonly result in
avoidance behaviors (e.g., increased hand washing and dust removal or using alternate play
areas) which could result in decreased exposure. Although these are neither consistent nor
permanent remedies for reducing or eliminating exposures, such activities can influence the
results of health studies and may be identified by structural equation modeling.
In some cases, results from health studies based on children's blood lead analyses have not
been the same as IEUBK model predictions. There are several adequate scientific
explanations for this observation which the risk manager may choose to verify through further
investigation. The TRW or regional risk assessor can provide assistance in both the design of
blood lead studies and in further investigations. Health studies for lead exposures have been
conducted for the following Superfund mine waste sites: Bunker Hill in Idaho, Coeur d'AIene
-'' U.S. Environmental Protection Agency (EPA). 1996 Methodology for Assessing Risks Associated with Adult Exposure to
Lead in Soil. Technical Review Workgroup for Lead. Office of Solid Waste. October.
:J U.S. Environmental Protection Agency (EPA). 199& Use of IRIS Vafues in Superfund Risk Assessment. PB93963360.
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Chapter 8: Scoping and Conducting Risk Assessments 8-11
Basin in Idaho and California Gulch in Colorado. Health studies for arsenic exposures have
been conducted at Anaconda site in Colorado and Asarco/Tacoma site in Washington state
(these sites included smelters).
8.6 Probabilistic Analysis
All risk assessments, both ecological and human health, should present an analysis of
uncertainties associated with the risk evaluations. One approach to quantitatively address
uncertainties is probablistic analysis. Monte Carlo simulation, a type of probabilistic analysis,
produces multiple risk descriptors instead of single numerical values to provide a range of risk
estimates. Monte Carlo simulation calculates outcomes based on those situations with inherent
variability and informational uncertainty. It also can present the degree of uncertainty
quantitatively. Probabilistic analyses should only be applied when critical parameters have valid
distributions of values available and when the parameters of concern effect a significant impact
(as determined through sensitivity analysis) upon the risk results. A sensitivity analysis of
parameters and range values should be presented. A primary difficulty in using probabilistic
analyses in risk assessment is the ability to identify relevant databases for the development of
appropriate distributions. Some guidance on the use of probabilistic analyses in risk
assessment is available from EPA23 24; regional guidance may also be available.
8.7 Risk Characterization
The risk characterization section of the risk assessment encompasses the presentation of
ecological and human health risks in the context of their magnitude, significance, uncertainty,
and implications for current and future site uses. It is a critical point in directing remedial action
plans and hence, must be comprehensive and clear. The EPA Administrator's 1995
memoranda on risk characterization, cited above, explain these concepts in more detail. These
memoranda also recommend that risks be provided in terms of a range from average
exposures to upper bound exposures.
8.8 Risk Communication
A plan for risk communication should be developed simultaneously with scoping and work plan
development. The plan should not only consider residents, landowners, and trustees, but
should also include other stakeholders in federal, state and local agencies (including EPA
regional offices). Information regarding community relations is provided in Chapter 6 of this
document. Because PRPs may be involved in CERCLA activities in more than one EPA region,
communication among site managers and risk assessors in different regions is important.
Communication strategies should be further coordinated between EPA and the PRPs. In some
cases the PRPs may sponsor a health study on area workers or community residents. In such
situations, it is essential that communication of risk and health information provided
simultaneously by EPA and the PRP should strive to minimize confusion and stress on the
recipients of this information.
:l U.S. Environmental Protection Agency (EPA). 1992. Memorandum from F. Henry Habicht regarding Guidance on Risk
Characterization for Risk Managers and Risk Assessors. Office of the Administrator. Washington, DC. February 26.
:' U.S. Environmental Protection Agency(EPA). 1997. Guiding Principles for Monte Carlo Analysis. EPA/630/R-97-001 March
1997. • '
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8-12 Chapter 8: Scoping and Conducting Risk Assessment
8.9 Removal Actions
Risk assessments that support removal actions are usually separate from the baseline risk
assessment for the longer term cleanup decisions; however, such risk assessments may help
to direct, and possibly become a part of, the baseline risk assessment which supports the
remedial investigation. Because the time frame of a removal action is rapid, so is the
accompanying risk assessment. Consequently it commonly focuses on one or a limited number
of contaminants and exposure pathways. |t may account for only a human receptor group or
only ecological receptors, or it may address both together. For example, risk of a catastrophic
or a large scale event affecting critical ecological habitat may require immediate action,
supported by an abbreviated but adequate risk assessment. For large and complex sites, once
a removal action and supporting risk assessment are completed, in most cases a baseine risk
assessment will be required for the overall site.
The decision to implement a removal action or a remedial (long term) action is a risk
management issue. Although not part of risk assessment, information regarding educational
and health intervention programs are included here because it specifically addresses the
exposure and toxicity issues discussed ri this chapter. Educational and health intervention
programs can be an integral part of site management strategies. If communities are educated
they can help to protect themselves while final cleanup actions are selected and implemented.
Therefore local and state health departments should be consulted early in the process to
recommend strategies for achieving early risk reduction. ATSDR can also be a partner in these
efforts.
8.9.1 Health Effects
The health effect of concern for a removal action may be based on a chronic health effect that
adversely affects a large number of people (or ecological receptors) or a particularly sensitive
group (e.g., young children). It is also possible that the health effect of concern for a removal
action may be based on acute adverse health effects requiring more immediate medical
intervention. In contrast, the baseline risk assessment conducted during the remedial
investigation may need only to focus on a long term health effect. At present, EPA does not
have a database that provides acute human health toxicity criteria analogous to the Integrated
Risk Information System (IRIS), which provides chronic human health criteria. Site managers
and risk assessors should determine if particular acute toxicity criteria have already been
adopted in their region, or may coordinate with regional toxicologists to develop their own
criteria, or consult with the Superfund Technical Support Center at the National Center for
Environmental Assessment in Cincinnati.
8.9.2 Risk Management Considerations
During the initial scoping, work plan development and sampling and analysis plan for the
removal action risk assessment, the site manager and risk assessor should consider needs for
risk evaluations which may follow the removal activity. To the extent possible, removal, site
investigation, and long term cleanup activities should be coordinated and complementary. This
will help to avoid redundancy, promote efficient use of resources, and ensure that no
contaminants or exposures are inadvertently omitted from the risk evaluation.
In planning these efforts, recognize that education and health intervention programs have limits.
They cannot protect everyone, and the protective benefits can be lost if the prog ram should
become ineffective. Such programs are best utilized early in the process of mitigating risk at a
site. In general, EPA recommends that engineering controls be the principal tool for risk
reduction for final site management strategies because it provides a more permanent response
than ordinary reclamation activities or transient behavioral modifications. Local health officials
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Chapter 8: Scoping and Conducting Risk Assessments 8-13
can be instrumental in identifying particular segments of the community that may be the most
vulnerable. They can help focus targeted cleanup actions where education and health
intervention cannot be relied upon to provide the needed protection to vulnerable members of
the community. Health intervention can be :|n importa|| cojnponent of an overall site
management strategy. «
8.10 Sources of Additional Information
Additional information on the risk assessment process can be found at various EPA websites,
including http://www.epa.gov/oerrpage/superfund/programs/risk/index.htm, which discusses risk
assessment in the Superfund program. On this webpage there are inks to webpages that
discuss human health risk assessments, ecological risk assessments, the 'tools of the trade",
and forms to contact EPA with specific questions.
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•14 Chapter 8: Scoping and Conducting Risk Assessment
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Chapter 9
Site Management Strategies
9.1 Introduction
This chapter presents options that a site manager may consider for managing risk at
abandoned mining and mineral processing sites. The site manager may be a State, Federal, or
local authority or a private landowner and is most likely managing the site under a number of
regulatory and non-regulatory programs. As with any remediation project, strategic planning is
critical in abandoned mine characterization initiatives as well as clean-up activities. As part of
this strategic planning, the site manager, depending on the specific statutory authority used, the
level of resources needed to protect human health and the environment from impacts from an
abandoned mine, and the level of resources needed to address those impacts must strike a
thoughtful balance in establishing an effective site management strategy.
9.2 Managing for Risk Reduction
Generally, the ultimate goal of all characterization and clean-up activities at abandoned mine or
mineral processing sites is the reduction of risk. As discussed in Chapter 6-Scoping Studies,
the broad project goals for an abandoned mine-site investigation are to provide the information
required to characterize the site and define the risks, and subsequently to develop a program to
mitigate risks to human health and the environment.
Risk is comprised of three elements: a source, a receptor, and an exposure pathway by which
the receptor is exposed to the hazards from the source. The following describes an example of
these elements at mining sites.
Source. At an abandoned mine site, the source may be a waste unit, such as a tailings
impoundment, an area of contaminated soil or sediment from which contaminants may
be released, or the actual mine pit or underground workings.
Exposure pathways. The classic pathways for exposure at an abandoned mine site
are transport via air (e.g., fugitive dust), ground water (e.g., contaminated plumes), or
surface water (e.g., run-off). There are situations at mine sites wherein the pathway is a
flow of solid (e.g., waste rock pile slump) or semisolid (e.g., tailings released from an
impoundment) waste materials released from a waste unit.
In addition to these types of exposure pathways that take the hazard from the source to
the receptor, the receptor may actually come to the source for exposure (direct contact).
Examples of this include migratory wildfowl landing on C9ntaminated ponds or children
playing in contaminated soils; both situations have been observed at abandoned mine
sites.
Receptors. Historically, the primary receptors of concern at abandoned mine sites
have been humans. This includes people living or working at the mine site, visitors to
the site, and people living downgradient of the site.
Additional receptors now also drive the site manager's response, including aquatic
species (e.g., fish and invertebrates); terrestrial wildlife (e.g.; invertebrates, birds, and
mammals), and floral populations. Often at abandoned mine sites these environmental
receptors have been affected in the past and may no longer be present at the time the
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9-2 Chapter 9: Site Management Strategies
actions are taken. Furthermore a whole new ecosystem may have been created by the
changes at the mine site. In other cases, for example, where a threat of release is
present (e.g., an abandoned tailings dam that about to fail), the floral, terrestrial, and
aquatic populations may be in actual and imminent risk of impact.
The importance of using risk-based goals and objectives in developing the risk reduction strategy
lies in the ability to reduce risk by addressing all or any one of the risk elements. A hazard from
a source that has limited pathways to a distinct receptor population may be controlled simply by
eliminating that pathway. For example, an area of metal-contaminated soil may have only
fugitive dust or direct exposure as its pathway to any receptor; a covering of clean soil and sod
over the soil may virtually eliminate this pathway. While this example does not account for the
potential for soil biota to move the contaminants into the food chain, the reduction of major risk
pathways (i.e.; fugitive dust and direct exposure) may be considered sufficient for the goal of
minimizing risk.
In more complex cases commonly found at abandoned mine sites, the site management strategy
must address the source, pathway, and receptors; and most likely multiples of each. For
example, both a mine pit and a tailings impoundment may be active hazard sources, while
fugitive tailings dust, metal-contaminated groundwater, and acidified surface water may be
moving the hazard offsite, thus impacting human and environmental receptors.
To complicate the strategy more, the historic nature of many abandoned mine sites means that
exposures have been occurring over time and cumulative effects may need to be taken into
account. For example, human populations may have bioaccumulated contaminants. Likewise,
ecological resources may have been severely impacted to a point that they are no longer
present. An example of this is the effect that dusts laden with zinc, a phytotoxin, have had in
eliminating vegetation downwind from certain historically active pyrometalurgical operations.
Other examples may be fish populations eliminated from surface waters impacted by acidic or
toxic runoff from abandoned mines.
9.3 Categories of Activities that Address Risk Elements
In devising a response strategy to minimize risk, site managers should address the different
elements of risk (i.e., source, exposure pathway, and receptor) using one or more of several
broad categories of response actions. A variety of actual technological applications, engineering
controls, or other activities may be used within each of these response categories. These
technologies are discussed in Chapter 10 of this handbook.
Managing the Source. The source of contamination may be addressed by reducing, either in
part or entirely, the actual source material through removal (e.g., excavation and removal of
chemical-containing drums) or certain types of treatment (e.g., reprocessing of tailings).
Because of the large volume of source material (e.g., tailings, waste rock, and smelter slag)
that may be of concern at abandoned mine sites, source removal and/or treatment is often
infeasible, thus requiring the site manager to strategically focus on collection, diversion, and
containment (e.g., capping) activities.
Managing Exposure Pathways. Controlling exposure pathways at abandoned mining and
mineral processing sites maybe performed by implementing a variety of collection, diversion, or
containment activities. These engineering controls often take the form of some sort of capping
(e.g., preventing air release or direct contact), damming (e.g., stopping/diverting surface water
runoff), or constructing slurry wails (e.g., groundwater management).
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Chapter'9: Site Management Strategies 9-3
An additional management strategy and one of particular importance to managing abandoned
mines is control of waste management unitff(e.g., shbjing up taiOngs impoundment dams or
waste rock side dumps that are in danger of failing), thjs effort prevents the transport of waste
materials to new, non-managed locations, as" well as pfSvefiting the contamination of soil and
sediment, wetlands, surface water, and groundwater.
In addition to the control, diversion, and containment responses, exposure pathways may be
managed by cleaning up the contaminated media, especially groundwater and surface water
which are active transport media (certain contaminated media, such as soil and sediment, are
more often considered sources from which air and water may be contaminated and
contaminants subsequently transported).
Managing the Receptor Exposure. Controlling the hazard to receptors, whether human or
environmental, may include a variety of risk abatement or remediation activities. Individuals
may be removed (e.g., evacuated or relocated) if exposure pathways or sources cannot be
addressed, this is uncommon. Typically this actbn is not performed unless extremely high risk
is present, a situation not typical of abandoned mine sites. In fact, at many large Superfund
mine sites, residents live within the sites and are expected to remain. This presence of human
populations, however, may suggest that health intervention and education should be considered
to manage exposure until sources and exposure pathways have been controlled.
Similarly, in the case of environmental receptors, population studies may be performed to
assess the impacts and risk to the local flora and fauna. In cases where the environmental
receptors are significantly reduced or eliminated by historical exposure, the environmental
populations may be reintroduced (e.g., restocking, revegetating) or habitat reestablished such
that natural repopulation may occur. An example of the latter is stream reconstruction, which is
commpn in parts of the West, during which watersheds are returned to their natural states (e.g.,
heavy sedimentation removed, riffles and other structure rebuilt, associated wetlands
reconstructed). Note that certain stabilization and media cleanup activities may be used to
focus on wildlife rather than human health. Examples of this are wildlife fencing to route
migratory mammals around mine areas, or draining or netting contaminated ponds to keep
waterfowl from the water.
9.4 Time-Based Responses
Armed with the understanding of the categories of responses empbyed to address specific risk
elements, the site manager should further develop the strategic management plan by
incorporating the factor of time. In general, site managers should first consider whether any
time-critical actions are necessary. If the time critical actions do not completely minimize the
risk or are not selected, the site manager should then design a long-term response to
remediate the site, and determine whether any expedited response action may be appropriate
in the interim (i.e., while long-term response are studies and selected). These three time
factors are described as follows:
Time-critical actions. These are immediate actions necessary to address an actual or
threatened release. These typically involve removing or stabilizing a threat to human
health or the environment.
Interim responses. These are activities that are not time critical but for various
reasons (e.g., community needs/desires, because of risk abatement, or to address new
findings) need to be performed before a formal study and remediation can be
completed. Typical of an interim action are stabilization activities or health-based
expedited response actbns.
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9-4 Chapter 9: Site Management Strategies
Long-term responses. These responses typically include comprehensive site
characterization and evaluation of a variety of long-term clean-up activities. This type of
action often requires significant time for the characterization step and to address long-
term remediation needs (e.g., permanent reduction of toxicity, mobility and volume of
contamination through treatment).
9.4.1 Time-Critical Actions
The first consideration for addressing contamination is the determination of whether or not any
immediate threats exist at the mining or mineral processing site. Immediate threats maybe an
actual, ongoing, or threatened release. Should some immediate threat be identified, the site
manager should consider taking action to reduce the immediate risks.
Time-critical actions are characterized by a need for a rapid response to address the immediate
threat. Expedited characterization and incremental cleanups are the norm. Under certain
regulatory scenarios, these actions are mandated to be short term. Although generally short
term, under certain circumstances these actions can be extended. States may use time-critical
actions under their own jurisdiction in orderto address an immediate threat to its citizens or
resources.
Characterization activities, while expedited
to address the circumstances, are just as
important in planning for time-critical
actions as for long-term cleanup actions.
The evaluation of threat includes some
form of risk analysis, either formal or
estimated under the auspices of "best
professional judgement." This evaluation
should take into account the potential for
release (a moot point if the release is on-
going), the potential for migration, and the
presence and vulnerability of the receptors.
Characterization activities potentially
include monitoring, assessment,
evaluation, and other information gathering ' '
activities.
Once an immediate threat is identified and/or confirmed, a number of actions may be taken to
reduce the risk posed by that threat. Risk reduction activities may include removal or
stabilization activities such as removal of sources materials (e.g., excavation and disposal of
contaminated materials or waste), removal of contaminated media (e.g., removal of soil
contaminated by metals from smelter emissions), reinforcement of containment units (e.g.,
shoring up taiings dams in danger of failing), or construction of containment structures (e.g,
damming ditches or waterways to create reservoirs to contain contaminated runoff). Highlight
9-1 illustrates the use of removal activities in the Butte and Walkerville mining areas in
Montana.
Highlight 9-1
Butte and Walkerville
CERCLA removal actions have been extensively
used at the Silver Bow/Butte NPL mine sites. Time-
critical removal actions begun at the site in 1988 •
were based on two facts. First, the cities of Butte
and Walkerville are partially located within the site
boundaries so exposure potential was high; second,
elevated levels of lead and aisenic were detected in
the mine waste and in residential yard soils. Based
on the potential health effects from the lead and
arsenic, EPA believed it was essential that the waste
dumps be removed from residential neighborhoods
quickly rather than waiting for the long term
remediation effort to unfold.
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Chapter 9: Site M anagem ent Strategies 9-5
With increasing frequency; site managers are likely to be asked to address impacts from
abandoned mines sites that pose an immediate risk to the environment. Highlight 9-2 is a brief
: '; , discussion of how time-critical action in
the form of release containment was
used at the Talache Mine Site in Idaho.
Highlight 9-2
Talache Mine Site
In May, 1997, a large tailings pile failed at the Talache
Mine in Idaho (last operatbnal in the 1960's), releasing
tailings containing high concentrations of arsenic and
other heavy metals. The tailings washed over and
impacted approximately 45 acres of woodlands, 25 acres
of wetlands, and 3,000 feet of stream bed. IDEQ, initially
took the lead in directing the clean-up of the site, by
entering into a "consent decree" with the landowner.
Among other stipulations, the landowner was required to
immediately implement (during the summer of 1997) a
number of "interim corrective actions" to help prevent the
migration of additional tailings into the creek the following
spring.
It should be noted here that CERCLA
also gives EPA the authority to address
threats at sites that are not cbsed or
abandoned. This may be of particular
importance in the mining sector where
mine sites may be inactive rather than
abandoned because of the economics of
the metals markets. Should a release be
justifiably regarded as imminent or
substantial threat of release (i.e., a
tailings dam failure pending), a Federal
or a State agency may step in and take
time-critical action to mitigate the risk.
9.4.2 Interim Responses
After considering time-critical activities, site managers should consider whether any
opportunities exist for conducting activities that, while not time critical or directed at eliminating
the source of contamination, may temporarily decrease exposure from certain pathways.
Interim response actions may take any number of forms depending on the needs of the site
manager to control or mitigate a situation.
Control, diversion, and containment activities
typically focus on controlling exposures or
the migration of a release. These activities
may be traditional engineering controls (e.g.,
slurry walls, caps) or may utilize less
traditional means (e.g., phytostabilization—
see Highlight 9-3). These actions do not
necessarily result in a facility being returned
to ambient conditions; contamination may
still be present and additional investigations
or remediation may be required. As long as
the containment measures are maintained,
however, stabilized facilities commonly do not present unacceptable short-term risks to human
health or the environment. This allows site managers the opportunity to shift their resources to
health or environmental concerns elsewhere on the site (See Exhibit 9-1 for a review of EPA's
RCRA Corrective Actbn program's Stabilization Initiative).
Highlight 9-3
Phytostabilization
An example of stabilization is phytostabilization, the
planting of tolerant grasses on taiSngs to reduce or
eliminate contaminated fugitive dust emissions. This
process is considered a stabilization activity because
the contaminants are still in the taiings impoundment
and the grass does not serve as an isolating cap.
The impacts on downwind receptors from the fugitive
dust are, however, reduced or eliminated.
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9-6 Chapter 9: Site Management Strategies
Exhibit 9-1. RCRA Perspective
The Program
The Problem
The Need
The Solution
The Goal
EPA Office of Solid Waste Corrective Action program
Early implementation of the RCRA Corrective Action program focused on
comprehensive cleanups at a limited number of facilities. These final cleanups were
difficult and time- consuming to achieve. The emphasis on final remedies at a few
sites diverted limited resources from addressing releases and environmental threats
occurring at many other sites.
EPA sought to achieve an increased overall level of environmental protection by
implementing a greater number of actions across many facilities rather than
following the more traditional process of pursuing final, comprehensive remedies at
a few facilities.
In 1991, the Agency established tie Stabilization Initiative as one of the primary
implementation objectives for the Corrective Action program.
EPA seeks to increase the rate of corrective actions by focusing on near-term
activities to control or abate threats to human health and the environment and
prevent or minimize the further spread of contamination.
Whereas the goal of control, diversion, and stabilization activities is to control or abate threats
to human health and the environment and prevent or minimize the further spread of
contamination, Expedited Response Actions
(ERAs) may go beyond that goal in that they
may include programs to address the actual
health or environmental impacts caused by
the contamination at issue. A leading
example is the lead monitoring and
abatement program put in place as part of
the Superfund response activities at the
Silver Bow/Bulte NPL mine site in Montana
(See Highlight 9-4). In this particular case
one of the potentially responsible parties
(PRPs) funded the program. In other cases
(e.g., in the absence of any established
PRPs), the State or land management
agency may need to establish the funding.
Highlight 9-4
Butte/Walkerville ERA Action
In 1994, EPA, in conjunction with the State of
Montana and the City of Butte, MT, conducted an
Expedited Response Action (ERA) to address
elevated levels of lead in residential areas of the City
of Butte and the Town of Walkerville. The ERA is a
multi-pathway approach which includes: a blood lead
surveillance for children less than 72 months old; a
lead education/ awareness program for the
communities; identification/ monitoring of specific
lead sources including lead paint, indoor dust, soil
and drinking water; abatement/mitigation of identified
sources of lead; establishment of a Lead Advisory
Committee; and the cleanup of source area (waste
rock dumps and other related mine waste) in
residential areas.
This ERA was necessary because a ROD would not
be completed until 2001 and there was concern about
the elevated blood leads in Butte and the potential for
exposure to children from lead sources. This five
year project will be evaluated in the Record of
Decision (ROD) for the site in 2001 to determine if
these actions are addressing the lead sources on this
site.
Because of the nature of ERAs in
addressing health or environmental impacts
during an interim period while final action is
being formulated and evaluated, they may
often run concurrent to risk assessments
done as precursors to full-scale remediation.
It is important that the ERAs be a
.component of, or at least consistent with,
anticipated final remedies.
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Chapter 9: Site Management Strategies 9-7
9.4.3 Long-Term Responses
' . > f- . :;f *
The third strategic consideration for rnnie-site cleanup is long-term remediation and restoration.
These actions are not time-critical and, whilf linked to of consistent with interim measures, they
are not interim in nature. Long-term responses are the final comprehensive cleanup, or if
cleanup is deemed unnecessary or uneconomical, the final stabilization and monitoring efforts.
Long-term responses also include restoration activities such as revegetation, rebuilding of
wildlife habitat, and restocking of fish and wildife.
The framework of the long-term response varies depending on regulatory and programmatic
requirements, the site specific conditions, and the degree of risk posed to human health and the
environment. The following activities are generally undertaken to varying degrees.
Scoping. This is the initial planning phase during which available data is collected and
reviewed, regulatory requirements evaluated, work teams and community involvement
planned and any required health, safety and/or environmental impact plans developed
(see Chapter 6 for more on this subject).
Site Characterization. During this phase additional information may be acquired by
implementing sampling or analysis programs, or more regular long-term monitoring (see
Chapter 7 for additional information regarding sampling and analysis).
Risk Assessment. During this phase the risks to human health and the environment
are evaluated (see Chapter 8 for additional information regarding risk analysis). In
addition, a risk assessment maybe used to evaluate the potential effectiveness of
certain response activities.
Response Selection. During this
phase the types of appropriate
responses, both broadly (see Section
9.3 above), and specifically (See
Chapter 10 for additional information
regarding Remediation and Cleanup
Options) are selected. Typically a
range of responses are available and
should be evaluated. Highlight 9-5
presents the CERCLA evaluation
criteria, some or all of which may be
included in non-CERCLA response
evaluations, depending on legal
requirements or site specific needs.
Response Evaluation. During this
.phase the responses that were
implemented are assessed based on
monitoring of the results.
Note that these elements of a long-term
remediation effort are typical of the Remedial
Investigation and Feasibility Study (RI/FS)
and Record of Decision (ROD) development
conducted under CERCLA NPL site
remediations and the RCRA Facility
Highlight 9-5
CERCLA Evaluation Criteria
CERCLA established specific statutory requirements
for remedial actions; remedial actions must; 1) be
protective of human health and frie environment; 2)
attain Applicable or Relevant and Appropriate
Standards, Limitations, Criteria, and Requirements
(ARARs) or provide grounds for invoking a waiver 3)
be cost-effective; 4) utilize permanent solutions and
alternative treatment technologies or resource
recovery technologies to the maximum extent
practicable; and 5) satisfy the preference for
treatment that reduces toxicity, mobility, or volume as
a principal element or provide an explanation in the
ROD as to why it does not.
EPA, subsequently developed nine evaluation criteria
to address these statutory requirements and the
additional technical and policy considerations that
have proven important forselecting among remedial
alternatives. These criteria are: 1) Overall Protection
of Human Health and the Environment, 2)
Compliance with ARARs, 3) Long-Term Effectiveness
and Permanence, 4) Reduction of Toxicity, Mobility,
and Volume, 5) Short-Term Effectiveness (during
implementation), 6) Implementability, 7) Cost, 8)
State or Support Agency Acceptance, and 9)
Community Acceptance.
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9-8 Chapter 9: Site Management Strategies
Assessment (RFA) and Corrective Measures Study (CMS) conducted under the RCRA
Corrective Action remediations. As an alternative, a NEPA approach maybe considered as
presented in Exhibit 9-2 below.
Exhibit 9-Z Insight from a Similar Review Process
The Program
The
Comparison
Consideration
Issues
The Plan
National Environmental Policy Act of 1969 (NEPA) review process
Because of the broad similarities between the remedial investigation/feasibility study
(RI/FS) process and the NEPA review process, EPA has determined that
CERCLA/SARA is functionally equivalent to NEPA.
Specifically, NEPA requires Federal agencies to consider five issues during the
planning of major actions:
1) the environmental impact of the proposed action;
2) any adverse impacts which cannot be avoided with fie proposed implementation;
3) alternatives to the proposed action;
4) the relationship between short and long-term effects; and
5) any irreversible and irretrievable commitments of resources which would be
involved in the proposed action.
Generally, the NEPA EIS process produces a document that is sinilar to a CERCLA
RI/FS REPORT or Record of Decision (ROD). Both processes result in a decision
document outlining the basis for selection of a preferred alternative
9.5 Strategic Planning Considerations
9.5.1 AFlARs
Throughout any remedial actbn undertaken pursuant to CERCLA at an abandoned mining and
mineral processing site, the site manager must consider compliance with CERCLA ARARs.
ARARs are Federal, State, and local standards that are directly applicable or may be
considered relevant and appropriate to the circumstances on the site. The National .
Contingency Plan, at 40 CFR 300.5, defines ARARs as:
Applicable requirements- Those cleanup standards, standards of control, and
other substantive requirements, criteria, or limitations promulgated under federal
or state environmental or facility siting laws that specifically address a
hazardous substance, poflutant, contaminant, remedial action, location, or other
circumstance found at a CERCLA site. Only those state standards that are
identified by a state in a timely manner and that are more stringent than federal
requirements may be applicable.
Relevant and appropriate requirements- Those cleanup standards, standards of
control, and other substantive requirements, criteria, or limitations promulgated
under federal or state environmental or facility siting laws that while not
'applicable' to a hazardous substance, pollutant, contaminant, remedial action,
location, or other circumstance found at a CERCLA site address problems or
situations sufficiently similar to those encountered at the CERCLA site that their
use is well suited to the particular site.
Only those state standards that are identified by a state in a timely manner and that are more
stringent than federal requirements may be applicable or relevant and appropriate.
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Chapter 9: Site Management Strategies 9-9
These standards are an inherent part of the scoping process, but also affect the long-term
remediation, especially in the setting of cleanup stand.ards, as well as on meeting other
environmental land use regulations (e.g., r
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9-10 Chapter 9: Site Management Strategies
9.5.3 Brownfield Initiative
An emerging management tool that may be available to the site manager is the Brownfield
Initiative. This program encourages the cleanup and reuse of property that may require
environmental cleanup before it can be redeveloped (i.e., brownfields). In the past,
redevelopment of these properties often was avoided due to concern about environmental
liabilities. Under CERCLA's liability structure present and future owners of contaminated
properties can be held iable for cleanup even if they did not cause the contamination. The
Brownfield Initiative is an emerging EPA effort to reduce, wherever possible, the barriers to
redevelopment of contaminated properties. Where abandoned mine sites are in an area in
which the property may have some redevelopment potential (e.g., the city of Butte, Montana
has a number of abandoned mine sites wjthin the city's boundaries), site managers should
explore opportunities to use the Brownfield Initiative to assist their planning and remediation
activities. Additional information can be obtained from the EPA Brownfields website,
http://www.epa.gov/swerosps/bf.
9.5.4 Enforcement Considerations
Storm water runoff and discharge of other drainage from inactive and abandoned mines is often
subject to State or Federal regulatory program requirements. Historically, these programs have
been applied infrequently at inactive or abandoned mines. For example, while adits at inactive
and abandoned mines often have discharges that are technically subject to CWA's NPDES
requirements, most do not have a permit. Similarly, storm water discharge permits are required
at many mines but have never been applied for or issued. In order to develop an effective site
management strategy site managers should evaluate the discharges from a mine in the context
of applicable State and Federal regulations. In those instances where the mine site has
demonstrated contribution to environmental problems, enforcement of existing regulations
should be considered an essential element of mitigating risk. Making owners and operators
accountable for the discharges from their facilities should always be considered early in the site
management strategy devebpment process.
In those instances where current owners or operators are unwilling to comply with provisions of
the CWA (or an applicable State statute) addressing mine-site run-off the site manager may
want to consider enforcement actions to compel private parties to be responsible for the
environmental impacts of their facilities. For those mine sites where the current owner is unable
to meet current regulatory requirements the site manager may want to evaluate the feasibility of
invoking State or Federal statutes that look to the historic site owner or manager to take
responsibility for damaging releases to the environment. CERCLA is the Federal statute that
may be applicable in such instances; many states have similar authorities.
Other regulatory programs (discussed in Chapter 11) may also be. applicable to environmental
concerns at mine sites. Such programs vary considerably among states. The site manager is
advised to develop a site specific enforcement strategy in partnership with other Federal and
State agencies having jurisdiction over releases from the site. Developing an effective
enforcement strategy can be an effective way of meeting the environmental challenges
presented by inactive and abandoned mine sites, and is fundamental to meeting public
expectations that owners and operators take responsibility for their facilities.
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Chapter 9: Site Management Strategies 9-11
9.6 Additional Sources of Information.
Specific procedures and guidance fcjr EPA's rertjoval program are set forth in a ten-
volume series of guidance documents collectively titled, Superfund Removal Procedures
(The chapter on Removals in EPA's Enforcement Project Management Handbook
summarizes this guidance.) These stand-alone volumes update and replace Official
Solid Waste and Emergency Response (OSWER) Directive 360.3B, the single-volume
Superfund Removal Procedures manual issued in February 1988.
More information on the RCRA Stabilization Initiative is available in the 1991 guidance
memorandum, Managing the Corrective Action Program for Environmental Results: The
RCRA Facility Stabilization Effort.
CERCLA Compliance with Other Laws Manual, Part I, Overview, RCRA, Clean Water
Act, and Safe Drinking Water Act. U.S. Environmental Protection Agency (EPA),
August, 1988. Washington, D.C. OSWER Directive 9234.1-01.
CERCLA Compliance with Other Laws Manual, Part II, Clean Air Act and Other
Environmental Statutes and State Requirements CERCLA Compliance With Other Laws
Manual Part II. U.S. Environmental Protection Agency (EPA), August, 1989.,
Washington, D.C. OSWER Directive 9234.1-02.
Guidance for Conducting Remedial Investigations and Feasibility Studies Under
CERCLA. U. S. Environmental Protection Agency (EPA), October, 1988. Washington,
D.C. Office of Emergency and Remedial Response.
EIA Guidelines for Mining, U.S. EPA, September 1994. Washington D.C. Office of
Federal Activities.
Abandoned Mine Lands Preliminary Assessment Handbook, California Environmental
Protection Agency, January 1998, Department of Toxic Substance Control.
Rules of Thumb for Superfund Remedy Selection, U. S. EPA, August 1997, Office of
Solid Waste and Emergency Response
A Guide to Preparing Superfund Proposed Plans, Records of Decision and Other
Remedy Selection Decision Documents, U. S. EPA, July 1999, Office of Solid Waste
and Emergency Response.
Draft EPA and Hard Rock Mining: A Source Book for Industry in the Northwest and
Alaska, U. S. EPA, November 1999, Region 10 Office of Water
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9-12 Chapter 9: Site Management Strategies
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Chapter 10
Remediation and Cleanup Options
10.1 Introduction
The purpose of this chapter is to assist the user with a basic understanding of the types and
availability of remediation technologies for mining and mineral processing sites. An
understanding of the technologies available for mine site cleanup should help the site manager
design a successful and cost-effective site management strategy.
Following a background section (Section 10.2) the chapter addresses four general topics:
conventional technologies (Section 10.3); innovative/emerging technologies (Section 10.4);
institutional (i.e., non-engineering) controls (Section 10.5); and sources of information regarding
available technologies (Section 10.6).
Several appendices address innovative ways to clean up mining and mineral processing sites.
Appendix B includes information and references addressing conventional and innovative
remediation of Acid Mrie/Rock Drainage.
Appendix G provides more specific information regarding conventional mine remediation
technology.
Appendix H contains a discussion of innovative technologies in EPA's SITE Program
that may be applicable at mining and mineral processing sites.
Appendix K includes Information and references to Best Demonstrated Available
Technologies (BDATs) as developed under the RCRA Land Disposal Restriction
program.
Appendix L presents efforts under the Mine Waste Technology program to find
innovative remediatbn techniques.
Appendix M includes additional remediation references, addressing RCRA Corrective
Action program, general groundwater remediation, and remediatbn of cyanide heap
leach operations.
10.2 Background
EPA, other Federal agencies, States, and Tribes have been managing investigations and
cleanup activities at mining and mineral processing sites for over two decades. A large number
of cleanup technologies have been successfully empbyed in the remediation and management
of mining wastes. Because of the unique problems associated with the cleanup of mining and
mineral processing wastes, new technologies, as well as new approaches to utilizing older
technologies, are constantly being developed. Progress in understanding the behavior of
contaminants has led to a series of new technologies being developed to address Superfund
sites in general and mining and mineral processing sites in particular.
It is important that the site manager understand differences in the types of remediation
technologies when evaluating them. Certain emerging technologies may be effective on a
small scale but may not have been tested in a large-scale applicatbn. In other cases, the site
manager needs to be .aware that innovative technologies tested on one type of waste or media
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10-2 Chapter 10: Remediation and Cleanup Options
may not be directly applicable to other types of mining and mineral processing site waste or
media. For the purpose of this discussion, two broad categories of technologies (i.e.,-
conventional and innovative/emerging) characterize the universe of available and applicable
remediation solutions. A third category, institutional controls, will be discussed as it relates to
more traditional non-engineering controls.
Conventional Technologies. These are technologies with a successful track record in mine
site cleanup, or technologies that are considered standard practice for mine site management.
Such approaches have been widely applied to remediation of mining and mineral processing
sites, as well as other waste management units. Lime treatment for acid wastes is an example
of conventiona I technology.
Innovative/Emerging Technologies. Two types of technologies are included in this category.
Innovative technologies include processes or techniques for which cost or performance data is
incomplete and the technology has not yet been widely applied. An innovative technology may
require additional field scale testing before it is considered proven and ready for
commercialization and routine application at mine sites. Emerging technologies typically are
even earlier in the development process. While they are potentially appficable at mine sites,
additional laboratory or pilot-scale testing to document effectiveness is highly recommended.
Current initiatives at EPA and other Federal agencies encourage the consideration of
innovative/emerging technologies in site remediation.
Institutional Controls. For the purpose of this discussion, institutional controls are non-
engineering site management techniques or strategies used to protect human health and the
environment. Examples of institutional controls include fencing, zoning, health education,
easements and other deed restrictions, and interior-cleaning (i.e., removing contaminated dust
from interior of residences). These controls can bean integral part of an overall site
management strategy.
Information addressing the conventional and innovative/emerging technologies includes the
following (described below): a basic description, a relative-cost analysis, and a general
effectiveness evaluation as described below. Exhibit 10-1, found at the end of this chapter,
summarizes this information.
General cost information is presented as well in the form of a comparison to the other
technologies; cost information is based on 1998 data. The costs are presented as low,
medium, high, or very high. These costs do not include site-specific considerations that
may significantly impact the costs, including availability of power, materials, manpower
and/or equipment.
The general effectiveness of the technology at mining and mineral processing sites is
presented. Because the major contaminants of concern at most mining sites are
metals, the effectiveness discussion for each technology on that contaminant class.
Local site conditions can signjficantly impact the actual effectiveness at each mining and
mineral processing site.
In many cases the remediation process will utilize multiple technologies to develop a treatment
train (e.g., a series of technologies used in sequence in the remediation process).
Conventional technologies, innovative/emerging technologies, and institutional controls may all
be used in a integrated management strategy. As an illustration, a contaminated area maybe
bioremediated, with associated contaminated ground-water being pumped and treated
chemically, followed by filtration, and solidification and landfilling of the sludge, utilizing fencing
to restrict access to the landfill and contaminated area and creating an easement to access
certain areas.
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Chapter 10: Remediation and Cleanup Options 10-3
10.3 Conventional Technologies
The fundamentals of conventional treatment, collection and diversion technologies are
discussed in this section. In addition, those_ management techniques that remove the
contaminant from the site, such as the saleSSf useabie^rfiaterials or decontamination of
structures, are included as conventional technologies.
10.3.1 Treatment Technologies
For the purpose of this discussion, treatment technologies are those technologies that either
change the composition of the contaminant to form other compounds that are less dangerous
to human health or the environment, or limit contaminant mobility by physical or chemical
means. • •' .
Chemical Treatment. In chemical treatment, reagents are used to destroy or chemically
modify organic and inorganic contaminants, converting hazardous constituents into less
environmentally damaging forms. Typically, chemical treatment is used as part of a treatment
train, either as a pretreatment technique to enhance the efficiency of subsequent processes or
in post-treatment of an effluent. One of the common uses of chemical treatment at mining and
mineral processing sites is the use of lime to neutralize acid rock drainage (ARD) and to
precipitate the metals. The cost of chemical treatment ranges from tow to high depending site
conditions, including the chemicals that are used and the nature of the products that are
produced by the chemical treatment. As an example, if the sludge that precipitates after the
addition of lime is disposed as a solid waste, the additional cost of disposal would bring the cost
into the high range. In many cases the operating and maintenance (O&M) costs will be
significant over the life of the remediation. •' ' »
Larger chemical treatment operations may benefit from a high density sludge (HDS) treatment
system. A HDS process significantly reduces the volume of sludge compared to a basic lime
treatment by recirculating sludge and lime. For example, at the Iron Mountain Mine site in
California, a HDS treatment system reduced the costs associated with treatment by more than
15 percent while at the same time doubling the expected useful life of the on-site landfill and
producing a more chemically and physically stable sludge.
Stabilization. Stabilization refers to processes that reduce the risk posed by a waste by
converting the contaminants into a less soluble, less mobile, and, therefore, less hazardous
form without necessarily changing the physical nature of the waste. [Site managers should be
aware that the term "stabilization" is also used to describe interim remediation activities (e.g.,
capping) that may be used to stabilize a site in order to minimize further releases prior to actual
clean up.] An example of stabilization as a treatment is the pH adjustment of a sludge which
results in making the contaminants in the sludge less mobile. The cost of stabilization will be in
the medium to high range depending on treatment required for stabilization. The effectiveness
of stabilization is dependent on the nature of the materials to be stabilized and the subsequent
storage or disposal. Cement-based stabilization is often used for many metals to comply with
the treatment requirements of the Land Disposal Restrictions (LDRs).
Solidification. Solidification refers to processes that encapsulate waste in a monolithic solid of
high-structural integrity. Solidification does not necessarily involve a chemical interaction
between the waste and the solidifying reagents, but involves a physical binding of the waste in
the monolith. Contaminant migration is restricted by vastly decreasing the surface area
exposed to leaching and/or by isolating the waste within an impervious capsule. Encapsulation
may address fine waste particles (microencapsuiatfon) or large blocks or containers of wastes
(macroencapsulation). There is, however, inherent risk that the stabilized solidified waste
matrix will break down over time, potentially releasing harmful constituents into the
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10-4 Chapter 10: Remediation and Cleanup Options
environment. An example of the solidification technology involves the use of cement to solidify
contaminants into a large block. The cost of solidification ranges from medium to high
dependhg of the steps required to encapsulate the waste. A simple encapsulation into a large
concrete block would be an example of the medium end of the cost range. The effectiveness of
solidification is dependent on the potential for the solid to break down over time and allow the
encapsulation to be breached.
Thermal Desorption. Thermal desorption refers to treatment alternatives that use heat to
remediate contaminated soils, sediments, and sludge;s. Thermal desorption is used to separate
a contaminant from the containing media. The off-gas from the desorption unit typically must
be further treated. Temperatures utilized for thermal desorption of metals is high enough that
other contaminants, such as volatile-organic compounds, may actually undergo thermal
destruction, as discussed below. Thermal desorption is not commonly used at mining and
mineral processing sites since the common contaminants at these sites, metals, are not easily
heated to their gas-phase. The cost of thermal desorption is in the range of medium to high
and the effectiveness at most sites is poor since there may be only a limited quantity of
chemicals in the soils that can be easily heated to their gas-phase.
Thermal Destruction. Thermal destruction is a treatment alternative that uses heat to
remediate contaminated soils, sediments, and sludges. Thermal destruction typically uses
higher temperatures to actually decompose the contaminants, potentially with no hazardous
contaminant residues requiring further management. Thermal destruction is not commonly
used at mining and mineral processing sites since the process does not destroy metals, the
most common contaminant. The cost of thermal destruction is in the range of medium to high
and the effectiveness is limited to those materials that can be destroyed.
Vapor Extraction. Vapor extraction is an in-situ process that uses vacuum technology and
subsurface retrieval systems to remove contaminant materials in their gas-phase. Vacuum
extraction of vapors from contaminated soils and subsurface strata has been successfully
employed to remove volatile compounds from permeable soils. Typically, sites considered for
vapor extraction-based technologies are those where chlorinated solvents or petroleum
products, such as gasoline and other fuels, have spiled or leaked into the subsurface. Vapor
extraction is not commonly used at mining and mineral processing sites since metals that are
the typical target contaminant are not in a gas-phase in soil. The cost of vapor extraction is in
the range of medium to high and the effectiveness at most sites is poor unless a significant
quantity of chemicals are present within the soils in the vapor phase.
Solvent Extraction. Solvent/chemical extraction is an ex-situ separation and concentratbn
process in which a nonaqueous liquid reagent is used to remove organic and/or inorganic
contaminants from wastes, soils, sediments, sludges, or water. The process is based on well-
documented chemical equilibrium separation techniques utilized in many industries, including
the mining and mineral processing industry. In the mine-site remediation, one type of
solvent/chemical extraction technology (i.e., teaching) is used extensively, primarily because of
the application of accepted mining and beneficiation technologies to the remediation field. The
cost of solvent extraction is in the range of low to high depending on site characteristics, which
include: the media necessary to extract the contaminants, the system to recover the solution
with the contaminants, the process to remove the contaminants from the solution, and the
handling and disposal of the spent waste or soil. The effectiveness of solvent extraction is
good if the contaminants can be extracted by the liquid reagent.
Soil Washing. The ex-situ process of soil washing employs chemical and physical extraction
and separation techniques to remove a broad range of organic, inorganic, and radioactive
contaminants from soils. The process begins with excavation of the contaminated soil,
mechanical screening to remove various oversize materials, separation to generate coarse- and
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Chapter 10: Remediation and Cleanup Options 10-5
fine-grained fractions, and treatment of those fractions. Surficial contaminants are removed
through abrasive scouring and scrubbing action using a washwater that may be augmented by
surfactants or other agents. The soil is then separated from the spent washing fluid, which
carries with it some of the contaminants. The recovered sojls consist of a coarse fraction, sands
and gravels, a fine fraction, silts and days.fitnd an orgafiic*humic fraction, any or all of which
may be contaminated. The washed soil fraction may be suitable for redepositing on site or other
beneficial uses. The fines typically carry the bulk of the chemical contaminants and generally
require further treatment using another remediation prdcess, such as thermal destruction,
thermal desorption, or bioremediaton. The costs of soil washing would range from medium to
high similar to "soil flushing" discussed below, however the costs are impacted by the controlled
method of recovering the liquid and the excavation costs to remove the soil. The effectiveness
of soil washing is determined by the-ability of the washing liquid to remove the contaminants.
Soil Flushing. The in-situ process of soil flushing uses water, enhanced water, or gaseous
mixtures to accelerate the mobilization of contaminants from a contaminated soil for recovery
and treatment. The process accelerates one or more of the same geochemical dissolution
reactions (e.g., adsorption/ desorption, acid/base reactions, and biodegradation) that alter
contaminant concentrations in ground-water systems. In addition, soil flushing accelerates a
number of subsurface contaminant transport mechanisms, including advection and molecular
diffusion, that are found in conventional ground water pumping. The fluids used for soil flushing
can be applied or drawn from ground water and can be introduced to the soil through surface
flooding or sprinklers, subsurface leach fields, and other means. When the contaminants have
been flushed, the contaminated fluids may be removed by either natural seepage or aground
water recovery system. Depending upon the contaminants and the fluids used, the soil may be
left in place after the soi flushing is completed. The cost of soil flushing ranges from medium to
high depending on the means of applying the flushing fluid and the method of recovery of the
fluids used. The effectiveness of sol flushing is dependent on the characteristics of the sofl and
the fluid used for flushing. If the fluid can mobilize the required contaminants and be recovered,
the technology can be effective. There often is a problem, however, with either mobilizing the
contaminants or recovering the fluid that limits the effectiveness. In contrast, another concern
is that contaminants may be highly mobilized with the subsequent possibility of contaminating
ground water.
Decontamination of Buildings. Decontamination of buildings and other structures through
various extraction and treatment techniques may be necessary at certain mining and mineral
processing sites. The purpose of decontaminating the structures may be to meet the
requirements of historical preservation and/or to assist the community in attracting new
industry. Decontamination may be as simple as pressure washing a building or more complex,
involving partial removal techniques. As an illustration, if the contamination is a dust settled
throughout the building, a simple washing may remove the contamination; if, however, the
contaminant saturated wooden members of the structure, some of ail the wood may have to be
removed in order to decontaminate the building. The cost of decontaminating buildings and
other structures is dependent on the techniques needed to complete the decontamination
efforts. The effectiveness of decontamination of buildings is site specific and will be determined
by what the contaminants are being addressed and how effective the technique is in removing
them.
10.3.2 Collection, Diversion, and Containment Technologies
Collection, diversbn, and containment technologies are used at sites where treatment
technologies cannot control the contaminants to an acceptable level. These engineering
controls include technologies that contain or capture the contaminants to reduce or minimize
releases. This section discusses some of the containment technologies available to site
managers.
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10-6 Chapter 10: Remediation and Cleanup Options
Landfill Disposal. Landfills are waste management units, typically dug into the earth, but
including above ground units that are not exposed on the sides (i.e., not freestanding waste
piles), that accept waste for permanent placement and disposal. While landfilling is a
conventional disposal technology, it has had its share of recent innovations. Landfills may be
lined to contain leachate, drained with a leachate collection system, and capped. The cost of
landfills can range from medium to high at mining and mineral processing sites depending on
the site conditions that impact the design, including low permeability cover, bw permeability
liner, leachate collection, and leachate treatment. The O&M costs of leachate treatment or cap
maintenance can be significant. The effectiveness of the landfill is dependent on the design. A
landfill that can isolate the waste is effective. Should the cap or liner be breached, however, the
effectiveness will be greatly diminished. On-site landfills should be designed to meet site
specific cleanup goals and address applicable regulatory considerations.
Cutoff Walls. Cutoff walls are structures used to prevent the flow of ground water from either
leaving an area, in the case of contaminated ground water, or entering a contaminated area, in
the case of clean ground water. Types of cutoff walls include: slurry walls, cement walls, and
sheet piing.
Slurry walls are basically trenches refilled with a material (e.g., bentonite slurry) that
combines low permeabflity and high adsorption characteristics to impede the passage of
ground water and associated contaminants. The cost of slurry wails is in the medium
range, with depth being a factor on the cost due to equipment limitations. The
effectiveness of slurry waBs is dependent on the ability of the wall to get a seal on the
bottom (i.e., by contact with an impermeable soil or rock layer) to keep the ground water
from flowing under the slurry wall. Similarly, effectiveness is affected by constructbn of
the slurry wall with no gaps or other points for by-pass.
Cement walls are similar to the slurry walls, except that instead of a low permeability
clay-type slurry, a cement-based sjurry is used. Construction may be by trench and fill
as with the slurry wall construction. Alternately, construction may utilize a larger
excavation in which forms are constructed to pour a concrete wall after which the
excavated area around the wall is backfilled. The backfill may be with a high
permeability material used to capture and channel the ground water flow (e.g., for
recovery if contaminated, or to prevent its contamination). The cost of the cement walls
is greater than the slurry walls especially if the wall is formed in place, with a cost range
of medium to high. This increased cost however may buy an increase in effectiveness.
Sheet piling is a technology that is often used to install a cutoff wall. Sheet piling has
been used in the past to funnel ground water to a treatment cell for treatment and is
regularly used as a temporary cutoff wall during the remediation period. The cost of the
sheet piling is in the medium to high range, with the high range utilizing a better
mechanism to seal the joints between the sheets. The effectiveness of sheet piling is
similar to the slurry wail, however there is a greater potential of the wall to have leaks at
the joints.
Pumping Groundwater. A pump-and-treat process for addressing groundwater contamination
is a combination of an extraction technology (pumping) and a subsequent treatment
technology; this discussion focuses on the pumping portion of the combination. The treatment,
which can vary by contaminant, could be any of the other technologies discussed above. The
pump-and-treat technology has been the preferred method of remediating contaminated ground
water. The cost of the pumping portion ca:n range from medium to high, including, but not
limited to, the number and spacing of wells, the volume to be pumped, and the depth to ground
water. The long-term effectiveness of this procedure is limited for certain contaminants,
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Chapter 10: Remediation and .Cleanup Options 10-7
especially some metals, in certain soil types. Consideration must be given to such factors as
desorption rates and chemical properties of the contaminants themselves.
Capping. Capping is typically used to coyer a contaminated area or waste unit to prevent
precipitation from infiltrating an area, to p^f Vent coritlttiiriated material from leaving the area
and to prevent human or animal contact with the contaminated materials. An example of
preventing releases is the growing of vegetation on taflings to prevent fugitive dust from blowing
off and being transported downwind. A example of preventing human contact is the removal
and replacement of a specified depth of soil in a residential area which has been used to
protect the residents from the contaminated subsoils.
Capping could include: surface armoring, soilfclay cover, soil enhancement to encourage
growth, geosynthetic or asphaltic cover system, polymetric/chemical surface sealers,
revegetation, concrete and synthetic covers. The cost of caps can range from tow (e.g.,
planting grasses) to high (e.g., synthetic caps) depending on the cap selected. The cap mayor
may not be effective in achieving multiple performance objectives, for example; a cap designed
to minimize erosion, however, may not be an effective cap to minimize infiltration and vice
versa. ~ -
Detention/Sedimentation. Detention/sedimentation controls are used to control erosion and
sediment laden runoff. "Treatment" generally consists of simply stowing the water flow and
reducing the associated turbulence to allow soBds to settle out. Settling may be allowed at
natural rates; in other cases flocculants may be added to increase the settling rate. The settled
sediments may be removed and disposed; if the sediment is contaminated then treatment may
be required. The cost of detention and sedimentation is generally in the range of low to
medium, depending on the O&M costs to remove the settled solids. The
detention/sedimentation basins can be effective if they can be designed to allow the proper
amount of settling time; however, in some cases the solids settle at a very stow rate and a
portion of the solids leave the settling basin.
Settling Basins. Settling basins may be used to contain surface waters so that contaminated
sediments suspended in the water column can be treated, settled, and managed appropriately.
Dissolved contaminants and/or acid waters may be contained as well to allow for treatment or
natural degradation (e.g., contained cyanide will degrade naturally). As the impoundment fills
with the solids that have settled out, solids must be removed and disposed of in order for the
impoundment to continue working effectively. The cost of operating settling basins is in the low
to medium range, depending on the construction of the impoundment and dam. For example, a
lined impoundment will cost more than an unlined impoundment. The O&M costs of the settling
basin could be significant over the life of the basin to remove and dispose of any settled solids.
Properly designed settling basins can be effective in removing suspended solids from surface
waters.
Interceptor Trenches. Interceptor trenches are trenches that have been filled with a
permeable material, such as gravel, that will collect the ground water flow and redirect it for
either in-situ or ex-situ treatment: Interceptor trenches are often used to collect and treat
ground water and prevent it from leaving a containment area, such as a landfill. The initial cost
of interceptor trenches is low to moderate depending on the availability of materials. However,
the O&M cost can be significant if the liquid flowing through the trench precipitates material that
will plug the trench, thus minimizing the permeability and requiring the permeable material to be
cleaned or replaced. Interceptor trenches are effective at capturing ground water flow if the
permeability of the media in the trench is greater than the native material.
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10-8 Chapter 10: Remediation and Cleanup Options
Erosion Controls. Erosion controls are those engineering controls used to eliminate or
minimize the erosion of contaminated soils by either air or precipitatbn (i.e., stormwater or
snow melt). Erosion controls include:
Capping or covers (as discussed above), particularly in the form of revegetation,
polymer/chemical surface seaters, armoring and soil enhancements. The caps or
covers for erosion control, in general, are lower than the costs of caps to limit infiltration.
The cost range of the erosion control caps is |ow to medium. The O&M costs of the cap
could be significant, particularly if the cap or cover can be easily damaged. For
example, if revegetation is selected, then the O&M costs will include revegetating areas
where the vegetation does not grow, or is damaged by factors which could include
natural conditions such as drought or insect invasion. The effectiveness of the caps or
covers to prevent erosion is dependent on site conditions, however the caps or covers
should generally prevent the erosion of soils by either water or air.
Wind breaks are used to minimize the erosion of soils and dusts by the wind and can
include planting of trees and other vegetation to reduce the wind velocity, and/or the
installation offences. The cost of wind breaks is generally in the, low to medium range.
The effectiveness of wind breaks is dependent on the prevailing wind. In general, wind
breaks are not as effective at eliminating airborne dust as the caps or covers.
Diversions (as discussed below) are used to control surface water around areas that
have a high probability of erosion. An example of this would be construction of a
diversion ditch to capture runoff which prevents the flow from reaching a steep slope,
where it could cause erosion.
>
Diversions. Diversions are engineering controls that are used to divert ground water or
surface water from infiltrating waste units or areas of contamination, thereby preventing the
media from being contaminated and pollutants from leaching and migrating. Two types of
diversions are run-on controls and capping:
Run-on controls prevent surface water from entering waste units or areas of
contamination and becoming contaminated. For example, surface waters may be
diverted to avoid contact with stockpiled waste rock. This would prevent the water from
becoming acidified. Examples of run-on controls would include retaining walls, gabion
dams, check dams (both permanent and temporary), and diversion ditches. The costs
of run-on controls are low to medium depending on the method used for. the diversion.
The use of run-on controls to divert surface water away from areas of contamination is
effective in reducing the quantity of water that requires treatment.
Capping is the placement of synthetic liners or impervious earthen materials (typically
clay) to prevent precipitation from infiltrating waste materials or severely contaminated
areas and leaching contaminants into the ground water. This allows water to be
captured and diverted elsewhere. The cost and effectiveness of caps are discussed
above.
Stream Channel Erosion Controls are used to minimize the mobilization-and transport of
contaminated sediments by streams within the site. At many mining and mineral processing
sites, historic transport of contaminated sediment into the stream has occurred. Many sites
have areas where these sediments have been deposited along stream shores and beds.
Stream channel erosion controls can be used to minimize the remobilization and transport of
these sediments, often during periods of high flows. Technologies to control stream channel
erosion often include both erosion controls and diversions such as channelization or lining of
stream channels, diversion dams and channels (construction of diversion dams and or channels
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Chapter 10: Remediation and Cleanup Options 10-9
to reduce flow to contaminated areas arid ground water recharge areas, to reduce water
velocity, trap sediment and divert clean water), riprap, and gabions. The cost of these controls
can range from low (e.g., revegetation of stream banks) to high (e.g., diversion to an
engineered channel) depending on the site Conditions., Some of the technologies may be
temporary until other remediations are completed. The t)&M cost to the erosion controls could
be significant, especially with damage from flood events.
10.3.3 Reuse, recycle, reclaim • '"''
Sale of Useable Materials. Sale of materials that can be utilized by other is another
management approach that the site manager may employ. The useable materials could
include: finished product in the unlikely case that any remains on site; supplies of materials that
remained unused at the site; feedstocks, ore or concentrate that remans on site; demolition
debris for reprocessing; and/orwaste materials for reprocessing. The cost from this technology
may be either low or positive. In evaluating the cost of selling useable materials, the cost
should be compared to the cost of disposal to ensure that the cost of selling the material minus
any money received is actually less than the cost of disposal. Recycling or reusing these
materials is an effective means of eliminating contaminants, although there generally are flmited
materials that should be sold.
Remining/Reprocessing. Remining is the process of taking mine "waste" material and
running it through a process to recover valuable constituents. Remining typically utilizes the
same mining and beneficiation processes discussed in Chapter 3 to extract metal contaminants
from tailings or other waste materials. For example, tailings may be reprocessed to recover
metals that remain, by any or all of the following methods: gravity separation (if there is a
difference in the specific gravity of the desired mineral and the rest of the tailings), flotation, or
leaching.
The cost of remining/reprocessing may range from profitable to high depending on the cost of
the remining/reprocessing minus the value paid for the metals or other materials. The "new
tailings" can be placed in an engineered containment facility which generally is more desirable
than the existing facility, thereby minimizing the potential of releases to the environment. The
"clean tailings" may also have other beneficial uses, depending on the characteristics of the
tailings. The effectiveness of the remining and reprocessing can vary significantly depending
on the site. In general, however, it is very effective for the portion of the waste that is
reprocessed.
10.4 Innovative/Emerging Technologies
The following treatment technologies are considered to be innovative/emerging technologies.
The discussion is intended to provide examples; innovative and emerging technologies are
continually evolving and information addressing these technologies will necessarily be obtained
from individuals and organizations with ongoing characterization and remediation activities,
investigations, or research.
Bioremediation, for the purpose of this discussion, refers to the use of microbiota to degrade
hazardous organic and inorganic materials to innocuous materials. Certain bacteria and fungi
are able to utilize, as sources of carbon and energy, some natural organic compounds (e.g.,
petroleum hydrocarbons, phenols, cresols, acetone, cellulosic wastes) converting these and
other naturally occurring compounds to byproducts (e.g., carbon dioxide, methane, water,
microbial biomass) that are usually less complex than the parent material. At metal
contaminated sites, such as mining and mineral processing sites, the addition of biological
nutrients has been demonstrated to stimulate natural microorganisms to operate a natural
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10-10 Chapter 10: Remediation and Cleanup Options
process for biological attenuation and stabilization of heavy metals. The cost of bioremediation
is in the range of medium to high; as the technology evolves the cost may decrease.
Phytoremediation is the use of plants and trees to extract, stabilize or detoxify contaminants in
soil and water. The phytoremediation process generally describes several ways in which plants
are used to remediate or stabilize contaminants at a site. Plants can break down organic
pollutants or stabilize metal contaminants by acting as filters or traps. The three ways that
phytoremediation works are: phytoextraction, rhizofiltration, and phytodegradation.
Phytoextraction, also termed phytoaccumulation, refers to the uptake of metal
contaminants by plant roots into stems and leaves. Plants that absorb large amounts of
metals are selected and planted at a site based on the type of metals present and other
site conditions that will impact the growth. The plants are harvested and either
incinerated or composted to recycle the metals. The cost of phytoextraction is in the low
to medium range depending on site conditions and the costs of disposal of the
harvested plant material The O&M costs may be significant if the plants need to be
harvested for many years. The effectiveness of phytoextraction has been good for
some metals where there are shallow, low levels of contamination; the technology is,
however, considered innovative for most metals.
Rhizofiltration is used to remove metal contamination in water. The roots of certain
plants take up the contaminated water along with the contaminants. After the roots
have become saturated with metals, they are harvested and disposed. The cost of
rhizofiltration is in the low to medium range depending on site conditions and the cost of
disposal of the harvested plant material. The O&M costs may be significant if the plants
need to be harvested for many years. The effectiveness of rhizofiltration is not yet
determined as the technology is considered innovative.
Phytodegradation is a process in which plants are able to degrade organic pollutants.
Phytodegradation is not currently used for inorganic contaminants.
Vitrification. Vitrification is a sofidification process employing heat to melt and convert waste
materials into glass or other crystalline products. Waste materials, such as heavy metals and
radionuclides, are actually incorporated into the relatively strong, durable glass structure that is
somewhat resistant to leaching. The high temperature also destroys any organic constituents
with byproducts treated in an off-gas treatment system that generally must accompany
vitrification. The cost of vitrification is very high and has not been commonly used at mining
and mineral processing sites. The effectiveness of the vitrification is dependent on the material
that is treated. If a glass like product can be made, the ability to isolate the waste is very
effective.
10.5 Institutional Controls
Institutional controls are non-engineered solutions (e.g., fencing and signing, zoning
restrictions) that are used to protect human health and the environment by controlling actions or
modifying behavior. Institutional Controls are part of risk management and a potential part of
the response. Risk should be evaluated for present site conditions and the various altrnative
future uses. It is in this latter element that the risk levels of specific future land uses and
institutional controls can be evaluated. Where residential exposures do not currently exist and
may not occur in the foreseeable future, institutional controls may be adequate to protect
against human health exposures (though active remediatbn still may be required for
environmental risks). In general, Institutional Controls can include, but not limited, a number
of activities as described below. The user is advised to consult the Institutional Controls: A
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Chapter 10: Remediation and Cleanup Options 10-11
Reference Manual, US EPA Workgroup on Institutional Controls - Workgroup Draft 1998 and/or
Institutional Controls: A Site Manager's Guide to Identifying, Evaluating and Selecting
Institutional Controls at Superfund and RCRA Corrective Action Cleanups, Draft March 2000,
OSWER 9355.0-74FS-P, EPA 540-F-OO for further d'etais on institutional controls.
': ||V .•.•..*•*'
Restricting Access is often used to minimize access to areas where there may be an
exposure. Erecting fenced, posting signs, utilizing guards or security services, and using fines
for unauthorized access all may assist in restricting access. The cost of fencing can be
significant if the area is quite large and O&M costs can also be significant if the fences need
constant maintenance to repair damage, either from natural causes or breaches. Fences can
be effective at restricting access; they may, however, in some circumstances encourage the
curious to trespass, the cost of posting signs is low and maintenance costs are generally low.
Effectiveness of the signs, however, is generally poor. While fining trespassers may be utilized,
the cost of enforcement may be significant if additional guards have to be employed. The
levying of fines generally has a limited effectiveness.
Deed Restrictions/Notices place legal restrictions on the use of and transfer or sale of the
property and provide the prospective purchaser with a notification of any requirements that
must be met on the property. The cost of implementing the deed restrictions/notices is tow.
The effectiveness of any of these deed restrictions/notices depends on the support of the local
government and/or the entity (i.e., easement holder) authorized to enforce controls. In addition,
the motivation to enforce these regulations may diminish as time passes after completbn of the
cleanup.
Zoning or Other Regulations restrict activities that could cause an exposure. The local
government must enact and enforce the regulations.* The cost of implementing the regulation is
low, however the costs of enforcing the regulations can be very expensive, especially to a local
government that may be depressed (i.e., because of a reduced tax base from loss of the mining
enterprise being addressed). The effectiveness of any of these regulations or zoning
requirements depends on the bcal government and community. The motivation to enforce
these regulations may diminish as time passes after the completion of the cleanup. Examples
of regulations include: restricting use of off-road vehicles in an area where the use could
damage the remediation and allow contaminants to be released by erosion (e.g., air or surface
water); speed limits for unpaved roads to limit the amount of dust that would be generated; or
load limits on roads to keep the surface from breaking down. An example of a zoning
regulation would include a regulation that would keep areas of the mining and mineral
processing site industrial or commercial.
Limited Future Development in a remediated area would require that future development not
damage the remedy or increase the exposure. The cost of implementing this is low; as with the
cost of zoning, however, it requires the community and local government to accept the
limitations. The effectiveness of this control is dependant on the local government willingness
to mandate and enforce limitatbns.
Regulatory Requirements are those requirements that are needed to keep the remedy in
place. They can be very important at a mining and mineral processing site that includes a
residential community. Examples of regulatory requirements include drilling permits, excavation
permits, or construction permits in areas where there is contamination at depth. The permits
would ensure that all activities where contaminated soils are exposed would follow certain
procedures to minimize any exposure'or re-contamination of clean soils. The costs of
implementing and managing these procedures would range from medium to high depending on
how the permits are issued and tracked. The effectiveness of this system depends on the
source of funding for the permit process and the willingness of the community and local
government to accept the requirements.
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10-12 Chapter 10: Remediation and Cleanup Options
Procedures for Soil Disposal are a set of procedures to handle and dispose of any
contaminated soils that are removed during normal activities, such as repairs to infrastructure
(e.g., roads and utilities) and development and expansion of existing houses and buildings.
The cost of these procedures will vary depending on requirements for handling and disposal. In
general, the costs would be anticipated to be in the medium to high range. The effectiveness of
these procedures is dependent on the acceptance of the community. If the procedures are
considered to be onerous or difficult, they probably will not be effective.
Health Education Programs are used to inform and educate the community of the risks from
the contaminated media. This can be a difficult task in an established community that does not
perceive a risk. The costs of the health educatbn program can range from low to high
depending on what is included in the program. For example, if health intervention and
monitoring are included as part of the program the costs wii be high. The effectiveness of the
health education program is dependent on community acceptance.
Interior Cleaning is a more effective way to remove contaminated dusts and soils from a
house. However, the cost of the cleaning every home can range from medium to high. If the
sources of the dusts and soils have not been removed, the home can become recontamJnated
in a short time. Programs to encourage interior cleaning can assist in reducing the risk from
contaminated dusts and soils that have entered the home, either via airborne dust or tracked in
by people or animals. An example of such a program was employed at the Bunker Hill
Superfund site in northern Idaho in which the program loaned vacuums with HEPA filters to
local residents. The costs of the programs are generally low, however the effectiveness varies
based on community acceptance.
10.6 Sources of Information and Means of Accessing Information Regarding Available
Technologies
Identifying innovative technologies or cross-applying technologies from conventbnal sites to
mining and mineral processing sites can be difficult as the technologies and their applications
are constantly changing and improving. It is extremely important that the site manager know
how to access information regarding these technologies. One goal of this handbook is to
provide the site manager with a roadmap to this information; the second goal is to encourage
the site manager to build a network of contacts. A network of individuals and organizations that
can answer questions and provide information regarding technologies is critical in the
development of remediation alternatives. This network may include government, academic,
and private sector entities. Former and current mine-site remediation managers are an
extremely valuable source of practical information regarding problems encountered at mining
and mineral processing sites and solutions, including both successful and unsuccessful
methods. Program and enforcement staff at EPA Headquarters and the ten EPA Regional
Offices, as well as State offices can assist site managers with understanding and addressing a
variety of issues related to Superfund, Applicable or Relevant and Appropriate Requirements
(ARARS), other standards, limitations, criteria, and other programs and initiatives. Other
Federal agencies, including the Department of Energy, the Department of Defense, the
Department of Agriculture, and the Department of Interior, are active in developing remediatbn
technologies and assisting mining operations. Universities and university-led centers (e.g.,
combinations of government, academic, and private sector entities) are actively exploring new
opportunities in remediation technologies. Finally, private sector entities are developing
technologies, although the nature of their business may limit easy access to innovative
technologies outside of a business relationship.
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Chapter 10: Remediation and Cleanup Options 10-13
Building these contacts into a network will assist the site manager in addressing ad aspects of
the site investigation and cleanup. To help begin this process, Appendix I of this reference
document includes a fist of contacts for EPA staff working with mining and mineral processing
related issues. ;
•"•'
In addition, the Internet websites identified in Appendix J allows the user to electronically
access a vast amount of data regarding remediation technologies and related topics. Other
sources of information have been analyzed and collected in the appendices as well. These
appendices are intended to provide the user with a guide to the many sources of information
regarding remediation technologies that are currently available. Some of the sources of
information available include: hotlines, libraries, universities and research centers, the Internet,
computerized bulletin boards, and technical documentation.
EPA has developed a large number of areas with information of potential use in identifying
remediation technologies. These include Web pages, a compendium of Superfund guidance
and technical documents, rule-making dockets, and various media- and program-based offices
(e.g., the Office of Water and the Superfund Office).
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Exhibit 10-1
Remediation Technologies Matrix
Technology
Bioremediation
Capping
Capping (Erosion)
Cement Walls
l_
Chemical
Treatment
Decontamination
Deed Restrictions
Detention/
Sedimentation
Fencing
I Fines
] Health Education
I Programs
Interceptor
I Trenches
I Interior Cleaning
Landfill Disposal
Type
I/E
C
C
C
C
C
1C
C
1C
1C
1C
C
1C
C
Media
S
S, sludges,
wastes
S, SW. A
GW
SW, GW
Structures
Land
SW
S.SW,
GW, A
S,A,GW,S
W
GW
S,A
S, Solid
Waste
Cost2
M-H
L-H
L-M
M-H
M-H
L-M
L
L-M
L-M
L
M-H
L-H
M-H
M-H
Effectiveness
Innovative technology.
Effective
Depends on site conditions,
generally effective
Effective
Effective
Depends pn site conditions
and contaminants
Depends pn community
acceptance
Effective
Fencing can be effective at
restricting access if the
fences are maintained.
Depends on community
acceptance
The effectiveness of any
health education program
depends on the community
acceptance.
Effective in capturing GW if
the permeability is greater
than native material
Can be very effective for
removing the exposure to
contaminants in interior
dust.
Effective as long as the cap
or liner are not breached.
„,/
Comments
O&M costs could be
significant if the cap or
cover is damaged.
O&M cost may be
significant.
O&M costs can be
significant, particularly for
long stretches of fence.
Needs local enforcement
and support to be effective.
Significant O&M costs if the
GW materials precipitate
and reduce the
permeability, requiring the
media to be replaced or
cleaned.
Re-contamination is
possible if sources have not
been remediated.
May have significant O&M
costs to maintain cap or
treat leachate.
Type: C - Conventional: I/E - Innovative/Emerging; 1C = Institutional Control
Media: S » Soil: GW = Ground Water; SW = Surface Water: A = Air
Cost: L - Low; M = Medium; H = High; VH = Very High
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Chapter 10: Remediation and Cleanup Options 10-15
Exhibit 10-1
Remediation Technologies Matrix
Technology
jmited Future
Development
3hytoextraction,
Phytodegredation
3rograms to
Encourage
Interior Cleaning
Dump and Treat
Regulatory
Requirements
Remining/
Reprocessing
Rhizofiltration
Run-on Controls
Sale of Useable
Materials
Settling Basins
Sheet Piling
Signs
Slurry Walls
Soil Disposal
Type
1C
I/E
1C
C
1C
I/E
C
C
C
c
c
1C
c
1C
Media
Land
S
S,A
GW
S
S, Wastes
SW, GW
SW
feedstocks,
wastes
SW
GW
S.SW,
Waste
Units
GW
S
Cost2
s&
L
L-M
L
M-H
L-H
L-M
L-M
L
L-H
M-H
L
M
M-H
Effectiveness
Depends on community
acceptance
Has been successful for
some metals
The effectiveness depends
on community acceptance.
Depends on site conditions
and contaminant
characteristics
The effectiveness depends
on community acceptance.
If all the material can be
removed, this is a very
effective tech nology; only a
limited amount of material
may, however, be available
for remining.
Innovative technology
Effective
Good
Effective in removing
suspended solids
Effective
Signs have a very limited
effectiveness
Effective
The effectiveness depends
on community acceptance.
Comments
May be considered
innovative.
Some community members
will not participate.
Needs a source of funding
to implement the permit
issuing and tracking
system.
Depends on the
characteristics of the
material to be reworked.
Recovering salable metal
may offset remediation
costs. The time to
reprocess large amounts of
material could be significant
and may not be acceptable.
Limited to those materials
that there is a market for.
May have significant O&M
costs over the life of the
dam.
May have "leaks" in the wall
O&M costs can be
significant if the signs keep
"disappearing"
May have "leaks" in the
wall.
Greatly depends on the
handing and disposal
requirements
Type: C = Conventional; I/E = Innovative/Emerging; 1C = Institutional Control
Media: S = Soil; GW = Ground Water; SW = Surfare Water; A= Air
Cost: L = Low; M = Medium; H = High; VH = Very High
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10-16 Chapter 10: Remediation and Cleanup Options
Exhibit 10-1
Remediation Technologies Matrix
Technology
Soil Flushing
Soil Washing
Solidification
Solvent Extraction
Speed Limits
Stabilization
Stream Channel
Erosion Control
Thermal
Destruction
Thermal
Desorption
Vapor Extraction
Vehicle Limits
Vitrification
Wind Breaks
Zoning
Type
C
C
C
C
1C
C
C
C
C
C
1C
I/E
C
1C
Media
S
S
S, sludges, '
wastes
S, wastes,
sludges
A,S
S, sludges,
wastes
SW
S, sludges,
wastes
S
S
S
S, Solid
Waste
S
S
Cost2
M-H
M-H
M-H
L-H
L
M-H
L-H
M-H
M-H
M-H
L
VH
L-M
L-M
Effectiveness
Site conditions affect fluid's
ability to mobilize
contaminants
Site conditions affect fluid's
ability to mobilize
contaminants
Depends on the ability of
the solid to break down over
time.
Depends on the solutions'
ability to extract
contaminants
The effectiveness depends
on community acceptance.
Dependent on the nature of
material to be stabilized.
Effective
Poor for metals
Depends on site
characteristics and
contaminants
Depends on site
characteristics and vapor
phase contaminants
The effectiveness depends
on community acceptance.
Effective
Fair to good effectiveness
The effectiveness depends
on community acceptance.
Comments
May be a concern wiih
contamination of ground
water.
Needs local enforcement
and support to be effective.
O&M costs can be
significant.
Not common at most mining
and mineral processing
sites.
Not common at most mining
and mineral processing
sites.
Not common at most mining
and mineral processing
sites.
Needs local enforcement
and support to be effective.
Not common at mining and
mineral processing sites.
Needs local enforcement
and support to be effective.
Type: C = Conventional; I/E = Innovative/Emerging; 1C = Institutional Control
Media: S = Soil; GW = Ground Water: SW = Surface Water; A = Air
Cost: L = Low; M = Medium; H = High; VH = Very High
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Chapter 11
The Regulatory 'Toolbox*
11.1 Introduction :
This chapter discusses the primary tools available to EPA project managers in developing
strategies for investigation and cleanup df an abandoned mine site. These same tools may
also be available to other federal agency and state personnel. In addition, there are a variety of
other tools available to state and federal resource managers and regulators that are not
discussed in this text The site manager is encouraged to refer to additional agency or state
resources to choose the best tools for a given site.
Regulation of mining activities occurs via a complex web of sometimes overlapping jurisdictions,
laws, and regulations covering several environmental media. Land ownership and tenancy
issues further complicate regulatory issues. Each abandoned mine site faces a somewhat
unique set of regulatory requirements, depending on State statutes or regulations; whether it is
on Federal, State, Tribal or private land; local regulations; and the specific environmental
considerations unique to the site. Although this chapter focuses on the various tools provided
by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
and its remediation process, especially as it relates to the unique characteristics of mine site
remediation, the use of other tools should be considered where appropriate. An overview of
some of the other tools available to the site manager are included in the later sections of this
chapter.
11.2 Background
Historically, CERCLA has been used as a tool to implement cleanup activities at a large number
of mining and mineral processing sites across the country. CERCLA authorities have been
used for cleanups ranging from the removal of drums of hazardous substances from long-
abandoned sites, to major privately funded cleanup actions at sites on the National Priorities
List.
The joint and several liability provisions of CERCLA are powerful tools in compelling private
parties to conduct cleanup actions at many sites. The availability of federal money to conduct
work when efforts to induce privately funded cleanups fail allows EPA an independent ability to
respond to public health and environmental threats. The cost recovery provisions of CERCLA
make it possible for the government to be reimbursed for the cleanup costs it incurs.
CERCLA is a very flexible tool for addressing the environmental risks posed by mining and
mineral processing sites. Other chapters of this document discuss technical aspects of
conducting cleanup work at mining and mineral processing sites. Equally important, however,
are the policy and administrative decisions regarding how CERCLA or other authorities can best
be utilized to implement site cleanup. If CERCLA is selected as an administrative tool to
implement site characterization and cleanup, it is critical to develop an overall strategy to
determine how CERCLA can best be utilized for cleanup of a mining or mineral processing site,
or a watershed affected by mining or mineral processing. Other programs at EPA appropriate
state agencies, tribes, local government, and other federal agencies also need to be involved in
determining how best to develop an integrated site management strategy.
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11-2 Chapter 11: The Regulatory "Toolbox"
11.3 CERCLA Jurisdiction/Applicability
11.3.1 Jurisdictional Conditions
CERCLA applies anytime there is a release or threatened release of: 1) a hazardous
substance into the environment or 2) a pollutant or contaminant "which may present an
imminent and substantial endangerment to the public health or welfare." The term "release" is
defined broadly in the statute, including any type of discharging or leaking of substances into
the environment. This also includes the abandonment of closed containers of hazardous
substances and pollutants or contaminants.
The definition of hazardous substance is extremely broad, covering any "substances,"
"hazardous constituents," "hazardous wastes," "toxic pollutants," "imminently hazardous
chemicals or mixtures," "hazardous air pollutants," etc., identified under other federal
environmental laws, as well as any substance listed under Section 102 of CERCLA. The fact
that a substance may be specifically excluded from coverage under one statute does not affect
CERCLA's jurisdiction if that substance is listed under another statute or under Section 102 of
CERCLA. A comprehensive list of these substances is provided in 40 CFR 302.4. From a
mining perspective, certain suifates are not listed, and thus may be excluded from the broad
coverage of "hazardous substances." Contaminants such as suifates, however, can be
covered under the more limited provisions of CERCLA relating to "pollutants and
contaminants," as will be discussed below. It should be noted that although all mineral
extraction and beneficiatbn wastes, and some mineral processing wastes are excluded from
RCRA Subtitle C regulation by the Bevill Amendment, these wastes may be addressed under
CERCLA.
11.3.2 Media
CERCLA is not media-specific. Thus, it may address releases to air, surface water, ground
water, and soils. This multi-media aspect of CERCLA makes it possible to conduct
environmental assessments and design cleanup projects that address site contaminants in a
comprehensive way.
11.3.3 Constituents
CERCLA covers almost every constituent found at mining and mineral processing sites.
Exceptions include petroleum (that is not mixed with a hazardous substance) and responses to
releases of a naturally occurring substance in its unaltered form. It should be noted, however,
that the latter exception does not include any of the releases typically dealt with at mining sites,
such as acid mine drainage, waste rock, or any ore exposed to the elements by man.
11.4 Implementation Mechanisms
11.4.1 Permits
CERCLA does not include any formal permit mechanism. CERCLA was essentially designed
as a tool to address problems in a "relatively short period of time. It was not intended to be an
ongoing "regulatory or permit" authority; thus, an infrastructure was not set up for long-term
regulatory compliance (e.g., more than 30 years).
Section 121 (e) of CERCLA waives any requirement for a federal, state, or local permit for any
portion of a removal or remedial action that is to be conducted entirely on site. Typically,
however, that action must be performed in accordance with the substantive environmental
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Chapter 11: The Regulatory "Toolbox" 11-3
requirements of the regulatory authority for which the permit was required. EPA usually has
taken the position that "on-site" includes a discharge to surface water within the site
boundaries, even though the water eventually flows off site. Some concern has been
expressed regarding the extent to which this waiver is valid after the CERCLA action is
completed. The Section 121(e) exemption is ^ssentiifor ensuring that EPA can carry out
remedial actions in a timely manner.
.11.4.2 Review/Approval
Typically, no review or approval is afforded under Superfund at new or existing facilities unless
there is a release or threat of release addressable under CERCLA. However, once jurisdiction
is established, the Agency has the capacity to review and approve any plans that address or
affect that release (See the Administrative and Injunctive Authorities section bebw).
Section 108(b) of CERCLA does give the Administrator the authority to promulgate regulations
that would require adequate financial assurance from classes of facilities that is consistent with
the degree and duration of risk associated with the productbn, transportation, treatment,
storage, or disposal of hazardous substances. The statute descrbes ways in which the
financial responsibility can be established (insurance, guarantee, surety bond, letter of credit, or
qualification as a self-insurer), and authorizes EPA to specify policy or other contractual terms,
conditions, or defenses for establishing evidence of financial responsibility. EPA has not, as
yet, used this authority.
11.4.3 Response Authorities
CERCLA's main strength is its response authorities. EPA can either use the Superfund (funded
primarily by an industry tax) to perform response (removal or remedial) activities (Section 104)
or require private parties to perform such activities (Section 106). CERCLA gives EPA the
flexibility to clean up sites based upon site-specific circumstances. EPA's cleanup decisions
are based upon both risk assessment and consideration of "applicable or relevant and
appropriate requirements" (ARARs). As long as the jurisdictbnal prerequisites have been met,
CERCLA gives EPA the ability to perform any activity necessary to protect public health and the
environment.
CERCLA provides EPA with the authority to perform "removal" actions, and "remedial" actions.
Assessments evaluate contaminants of concern, exposure pathways, and potential receptors.
The assessment process includes the review of all available information as well as sampling for
any other necessary information. The process is broad in its application and is a powerful tool
in evaluating environmental risks posed by a site. Removal actions can be performed on
mining and mineral processing sites of any size in an emergency situation (eg., implementation
can occur within hours) or over a long period of time. Removal actions are subject to limits on
time (12 months) and money ($2,000,000) under the statute; however, these limits are subject
to broad exceptions. For example, the Agency has implemented removal actbns costing in the
tens of millbns of dollars at mining and mineral processing sites.
Remedial actions are typically long-term responses performed at those sites placed on the
National Priorities List. Remedial actions may be performed at non-NPL sites only if they are
privately financed. Remedial actions are not subject to the time or dollar limitations imposed on
removal actions, but require a more detailed and formal decision process. Unlike removal
actions, however, remedial actbns to be implemented with Superfund dollars (when there are
no viable responsible parties) require a 10% state share in costs and a state assurance of
operation and maintenance before remediation can commence.
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11-4 Chapter 11: The Regulatory "Toolbox"
Land management agencies, such as the Forest Service and BLM have CERCLA response
authority, particularly when the site is not listed on the NPL. The land management agencies
and other natural resource trustees, such as the National Marine Fisheries Service and the Fish
and Wildlife Service, also have Section 106 order authority, to be exercised with EPA
concurrence, when response is needed on federal land or is needed to prevent an adverse
impact on natural resources.
11.4A Standard Setting
Under the current statute, CERCLA has no uniform national standard-setting authorities. The
NCR, at40CFR300.430(e)(9)(ii)(A-H), lists nine criteria, through which EPA can set site-
specific standards for clean-up and maintenance to minimize risk and satisfy ARARs.
ARARs, discussed below in Section 11.4.5, can be a very useful tool, as they give the Agency
the authority to impose standards that would not otherwise be appicable, if those standards are
determined to be relevant and appropriate under the circumstances. Of particular interest in
the mining context, EPA has the authority to use appropriate regulations adopted under RCRA
Subtitle C despite the fact that most mining wastes are excluded from regulation under RCRA
Subtitle C by the Bevill Amendment. Nonetheless, EPA can only require attainment of the
substantive aspects of relevant and appropriate standards, not the procedural requirements.
11.4.5 Applicable or Relevant and Appropriate Requirements
Under Section 121 (d) of CERCLA, remedial actions must comply with substantive provisions of
federal environmental laws and more stringent, timely identified state environmental or facility
siting laws. Removal actions must comply with ARARs also, but only to the extent practicable.
"Applicable" requirements are those federal or state jaws or regulatio'ns that specifically address
a hazardous substance, pollutant, contaminant, remedial action, location, or other circumstance
found at a CERCLA site. "Relevant and appropriate" requirements are not "applicable," but
address problem or situations similar enough to those at the CERCLA site that their use is well
suited to the site. State requirements are not considered ARARs unless they are identified in a
timely manner and are more stringent than federal requirements.
ARARs are contaminant, location, or action specific. Contaminant specific requirements
address chemical or physical characteristics of compounds or substances on sites. These
values establish acceptable amounts or concentratbns of chemicals which may be found in, or
discharged to, the ambient environment.
Location specific requirements are restrictions placed upon the concentrations of hazardous
substances or the conduct of cleanup activities because they are in specific locations. Location
specific ARARs relate to the geographical or physical positions of sites, rather than to the
nature of contaminants at sites.
Action specific requirements are usually technology based or activity based requirements or
limitations on actions taken with respect to hazardous substances, pollutants or contaminants.
A given cleanup activity will trigger an action specific requirement. Such requirements do not
themselves determine the cleanup alternative, but define how chosen cleanup methods should
be performed.
EPA has published a manual outlining all potential federal ARARs that may be requirements at
Superfund sites. Published in two parts, the manual is entitled CERCLA Compliance with Other
Laws Manual, Part I, August 1988, and Part II, August 1989, and is available at EPA libraries.
In addition, Appendix D discusses ARARs that are commonly utilized at mining and mineral
processing sites.
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Chapter 11: The Regulatory "Toolbox" 11-5
11.5 Compliance/Enforcement
11.5.1 Administrative and Injunctive Authorities }
!-:» - - .:ri!
CERCLA Section 106 provides for the issuance of admifiistrative order or injunctive relief under
the following conditions: (1) there may be an imminent and substantial endangerment to the
public health or welfare or the environment; (2) because of a release or threat of a release; (3)
of a hazardous substance; (4) from a faciBty. See GERCLA Section 106. (Note there are
conflicting opinions regarding authority under Section 106 for ordering cleanup of pollutants and
contaminants.) EPA typically only issues orders to parties that are potentially liable under
CERCLA Section 107. The scope of liability under CERCLA is broad. Anyone fitting the
following categories is fiable under CERCLA: 1) current owner (including lessees) or operator of
the facility; 2) past owner or operator at the time of the disposal of hazardous substances in
question; 3) anyone who arranged for the treatment, transportation, or disposal of the
hazardous substances in question; and 4) any transporter of the hazardous substances in
question if the transporter chose the disposal location. Liability is strict. That is, if the party falls
into one of the above four categories, it is liable, regardless of "fault." Liability for the
government's response costs is joint and several so long as the harm is "indivisible," i.e., there
is no rational basis for apportionment. The burden of proof as to whether harm is indivisible is
on the defendant, not on the government. Liability is retroactive, thus CERCLA can reach those
responsible for disposal activities prior to enactment of CERCLA.
Mining and mineral processing sites generally qualify as CERCLA facilities. A facility is defined
as "any building, structure,'installation, equipment, pipe or pipeline...well, pit, pond, lagoon,
impoundment, ditch...or any site or area where a hazardous substance has been deposited,
stored, disposed of, or placed, or otherwise come to be located...." Consequently, nearly any
feature of a mine site fits within the definition of "facility." EPA has the discretion to define
"facility" as broadly or narrowly as necessary to fit site-specific requirements. If the
jurisdictional requirements are met, EPA may either proceed directly with an administrative
order or request the U.S. Department of Justice to seek injunctive relief from a federal District
Court. Historically, the vast majority of work performed under these provisions has been done
administratively. Judicial intervention is relatively rare.
EPA has broad authority under CERCLA to require response actions. At existing facilities, EPA
could enjoin production activities or order changes to those activities (unless the activity is a
discharge pursuant to a federally permitted release). EPA can require the implementatbn of
institutional controls meant to reduce the endangerment posed by the presence of hazardous
substances or the removal of such substances to a more appropriate location (which must meet
ARARs and the off-site rule). EPA has broad discretion to choose response actions most
appropriate for particular sites (See Response Authorities above), provided such actions are
not "inconsistent with" the National Oil and Hazardous Substances Pollution Contingency Plan
(commonly referred to as the National Contingency Plan or NCP).
11.5.2 Cost Recovery
CERCLA Section 107 provides for the recovery of certain costs expended by the government in
responding to environmental contamination from responsible parties (as defined above). These
response costs must be incurred as a result of a release or threatened release of a hazardous
substance from a facility. In order for the United States, a state, or Indian tribe to recover costs
under this provision of CERCLA, the costs incurred have to be "not inconsistent" with the NCP.
Liability for response costs is strict, joint and several, and retroactive. The burden of proof as to
whether harm is indivisible is on the defendant, not oh the government
Section 107(d) of CERCLA provides exceptions to liability for those rendering care or advice at
the directbn of an On-Scene Coordinator (OSC) or in accordance with the NCP. A private
party who is not otherwise liable at the site, and provides advice or care at the direction of an
OSC in accordance with the NCP, will be exempt from liability for any costs incurred as a result
of actions or omissions by that party unless those actions or omissions are negligent.
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11-6 Chapter 11; The Regulatory "Toolbox"
Like most recovery provisions in the law, EPA's cost recovery authority does have a statute of
limitations. For removal actions, EPA must commence its cost recovery action within three
years of completion of the removal action (unless the removal action proceeds hto a remedial
action). For remedial actons, EPA must commence its cost recovery action within six years of
the initiation of physical on-site construction of the remedial action.
11-12 Chapter 11: The Regulatory "Toolbox"
11.11 Non-Regulatory Tools
In addition to the federal regulatory tools previously described in this chapter, there are a
number of non-regulatory tools that may be avaBable to the site manager. Non-regulatory
approaches available to address environmental challenges posed by mining are typically
employed to complement existing regulatory programs in addressing mining impacts; however,
there have been some instances where they have been used independently of any regulatory
framework. While current regulatory programs can often be adapted to address the
environmental problems posed by mining, they can be cumbersome, expensive to administer,
and understaffed. Non-regulatory tools have been developed to take advantage of the
incentives created by a backdrop of enforcement oriented regulatory programs, or to coordinate
these programs to maximize their overall impact. For example, when cleanups precede active
enforcement of regulatory programs they may be easier and less expensive to implement.
While recognizing that each non-regulatory effort is unique, there are certain themes that are
common to the most successful efforts.
The purpose of this discussion of non-regulatory tools include the following:
Illustrate the key traits of effective non-regulatory tools. Sometimes these will be based
on tools that have a regulatory connection, although the emphasis will be on the non-
enforcement aspects of those authorities.
Using specific case examples, point out areas where these tools have filled gaps in the
current regulatory framework.
Highlight model policies and approaches that could be the basis for future regulations or
legislation.
Point out the main limitations or non-regulatory approaches.
While recognizing that each non-regulatory effort is unique, there are certain themes that are
common to the most successful ones, both site specific and non-site specific. They include the
following.
Active participation by principal stakeholders, including a recognition of the environmental
problems and a wiiingness to take on the issues. This typically includes federal, state and bcal
governments, tribes, industry, citizens, and affected landowners. Participation does not
necessarily mean funding, but it does mean cooperation.
Creative use of limited funding resources, promoting coordination and research on mining
issues. While little public money is specifically earmarked for mine site cleanup, other
programs, such as EPA's CWA Section 319 funds, have been successfully used to fund
portions of cleanup projects. State programs, local contributions, and private funding by
responsible parties have all been tapped for assessment and cleanup projects. Technology
demonstrations have sometimes been used to get seed money to develop a new cleanup
approach. These include the University of Montana's Mining Waste Institute, a variety of
groups comprising the Mining Information Network, and the Western Governors' Association
(WGA).
Site specific flexibility, in adapting non-regulatory tools to fit the specifics of the site and the
interest of the stakeholders.
Pollution prevention, efforts supported by federal and state agencies, tribes, and other
stakeholders limiting the generation and use of waste materials.
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Chapter 11: The Regulatory "Toolbox" 11-5
11.5 Compliance/Enforcement
11.5.1 Administrative and Injunctive Authorities
CERCLA Section 106 provides for the issuance of administrative order or injunctive relief under
the following conditions: (1) there may be an imminent and substantial endangerment to the
public health or welfare or the environment; (2) because of a release or threat of a release; (3)
of a hazardous substance; (4) from a facifity. See CERCLA Section 106. (Note there are
conflicting opinions regarding authority under Section 106 for ordering cleanup of pollutants and
contaminants.) EPA typically only issues orders to parties that are potentially liable under
CERCLA Section 107. The scope of liability under CERCLA is broad. Anyone fitting the
following categories is Bable under CERCLA: 1) current owner (including lessees) or operator of
the facility; 2) past owner or operator at the time of the disposal of hazardous substances in
question; 3) anyone who arranged for the treatment, transportation, or disposal of the
hazardous substances in question; and 4) any transporter of the hazardous substances in
question if the transporter chose the disposal location. Liability is strict. That is, if the party falls
into one of the above four categories, it is liable, regardless of "fault." Liability for the
government's response costs is joint and several so long as the harm is "indivisible," i.e., there
is no rational basis for apportionment. The burden of proof as to whether harm is indivisible is
on the defendant, not on the government. Liability is retroactive, thus CERCLA can reach those
responsible for disposal activities prior to enactment of CERCLA.
Mining and mineral processing sites generally qualify as CERCLA faciOties. A facility is defined
as "any building, structure,'installation, equipment, pipe or pipeline...well, pit, pond, lagoon,
impoundment, ditch...or any site or area where a hazardous substance has been deposited,
stored, disposed of, or placed, or otherwise come to be located...." Consequently, nearly any
feature of a mine site fits within the definition of "facility." EPA has the discretion to define
"facility" as broadly or narrowly as necessary to fit site-specific requirements. If the
jurisdictionaI requirements are met, EPA may either proceed directly with an administrative
order or request the U.S. Department of Justice to seek injunctive relief from a federal District
Court. Historically, the vast majority of work performed under these provisions has been done
administratively. Judicial intervention is relatively rare.
EPA has broad authority under CERCLA to require response actions. At existing facilities, EPA
could enjoin production activities or order changes to those activities (unless the activity is a
discharge pursuant to a federally permitted release). EPA can require the implementatbn of
institutional controls meant to reduce the endangerment posed by the presence of hazardous
substances or the removal of such substances to a more appropriate location (which must meet
ARARs and the off-site rule). EPA has broad discretion to choose response actions most
appropriate for particular sites (See Response Authorities above), provided such actions are
not "inconsistent with" the National Oil and Hazardous Substances Pollution Contingency Plan
(commonly referred to as the National Contingency Plan or NCP).
11.5.2 Cost Recovery
CERCLA Section 107 provides for the recovery of certain costs expended by the government in
responding to environmental contamination from responsible parties (as defined above). These
response costs must be incurred as a result of a release or threatened release of a hazardous
substance from a facility. In order for the United States, a state, or Indian tribe to recover costs
under this provision of CERCLA, the costs incurred have to be "not inconsistent" with the NCP.
Liability for response costs is strict, joint and several, and retroactive. The burden of proof as to
whether harm is indivisible is on the defendant, not on the government
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11-6 Chapter 11: The Regulatory "Toolbox"
Like most recovery provisions in the law, EPA's cost recovery authority does have a statute of
limitations. For removal actions, EPA must commence its cost recovery action within three
years of completion of the removal action (unless the removal action proceeds into a remedial
action). For remedial actons, EPA must commence its cost recovery action within six years of
the initiation of physical on-site construction of the remedial action.
EPA has developed a "prospective purchaser" policy which affords a party interested in the
purchase of contaminated properties with protection from CERCLA liability by entering into a
settlement with the United States. Application of the policy can be difficult, as there are many
criteria that must be met, including a federal interest in the contaminated property, substantial
benefit to the Agency, the safety of continued operations, risk to persons at the site, municipal
interest, environmental justice, etc. From a mining site perspective, however, it may be a
worthwhile option to consider.
11.5.3 Civil Penalties
CERCLA imposes a fine of $25,000 per day for failure to comply with an order issued under
CERCLA (Sections 106(b) and 109). In addition, if EPA spends Superfund dollars performing
work where a responsible party has failed to perform such work under order, that party may be
liable for punitive damages in an amount equal to three times the costs incurred by the United
States. (Section 107(c)(3)). When EPA enters into consensual agreements with responsible
parties for the performance of work, it may also require stipulated penalties for the responsible
party's failure to adhere to the requirements of the agreement.
11.5.4 Criminal Penalties
Criminal penalties exist under only two provisions of CERCLA. The first is for failure to provide
notification of a release of a reportable quantity of a hazardous substance (Section 103(b)); the
second is for destruction of records that are supposed to be maintained under the Act (Section
103(d)).
11.5.5 Information Collection
Section 104(e) allows for investigations, monitoring, surveys, testing, and other information
gathering appropriate to identify the existence and extent of a release or threat thereof; the
source and nature of hazardous substances or pollutants or contaminants; and the extent of
danger to public health or welfare or the environment. Studies that may be conducted using the
information gathering authorities of section 109 may include planning, legal, fiscal, economic,
engineering, architectural, or others studies necessary or appropriate for planning and directing
response actions, recovering costs, or enforcement.
Specifically, Section 104(e)(2) requires that parties provide EPA with all information or
documents relating to (A) the identification, nature, and quantity of materials generated, treated,
stored, or disposed of at a facifity; (B) the nature and extent of a release or threatened release
of a hazardous substance, pollutant, or contaminant; and (C) the ability of a person to pay for or
perform cleanup.
Section 104(e)(3) provides the Agency with the authority to enter anyplace where a hazardous
substance or pollutant or contaminant (A) may have been generated, stored, treated, disposed
of, or transported from; (B) or from which there is a release or threatened release of a
hazardous substance; (C) or any place where entry is needed to determhe the need for
response, the appropriate response, or to effectuate a response.
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Chapter 11: The Regulatory "Toolbox" 11-7
Section 104(e)(4) gives EPA the authority to inspect, and obtain samples from, any location or
containers of suspected hazardous substances, or pollutants or contaminants.
If a party refuses to consent to EPA's information collecting activities, the Agency may issue
orders and/or seek court intervention providing for the "collection of information and provision of
access. Access may be granted through a warrant (where short-term access is necessary) or
by court order (for long-term or intrusive access circumstances).
CERCLA Section 103 also requires any person who is in charge of a facifity from which a
hazardous substance is released to report that release if it equals or exceeds the reportable
quantity for that hazardous substance listed pursuant to Section 102 of the Act. Sectbn 103
also requires any owner or operator "of a facility, owner at the time of disposal at a facility, and
transporter who chose to dispose of hazardous substances at a facility to notify EPA of the
existence of such facility if storage, treatment, or disposal of hazardous substances have
occurred at such facility. Thus, Section 103 provides broad authority for requiring the
submission of information necessary to identify the location of sites needing EPA's attention.
11.6 Other Superfund "Tools"
11.6.1 Funding
The Superfund is funded by both a tax on the chemical industry and some smaller contribution
of appropriated funds. The Superfund typically has enough money available to perform
necessary investigatory and cleanup activities. CERCLA does contain fund-balancing criteria to
ensure that the fund does not deplete its resources on any one site. Cost recovery by the
government is a critical element of ensuring the adequacy of Superfund.
11.6.2 Natural Resource Damage Provisions
Highlight 11-1
ARCO Natural Resource Damage Settlement
In November 1998, ARCO settled their Natural
Resource Damage Claims with the Federal
government, State of Montana, and the Confederated
Salish and Kootenai Tribes. The agreement sets
forth terms under which ARCO will pay to remediate
and restore Silver Bow Creek. In addition, ARCO
resolved the State and Tribes natural resource
damage claims for the Clark Fork River Basin.
CERCLA Section 107(a)(4)(C) provides for
the recovery of damages for injury to,
destruction of, or loss of natural resources,
including the reasonable costs of assessing
such injury, destruction, or loss. "Natural
resources" as defined at CERCLA Section
101(16) means "land, fish, wildlife, biota, air,
water, ground water, drinking water supplies,
and other such resources bebnging to,
managed by, held in trust by, appertaining to,
or otherwise controlled by the United '
States...any State or local government, any
foreign government [or] any Indian tribe... ." EPA is not responsible for recovering "natural
resources" damages due the federal government, as this responsibility generally lies with those
agencies that administer federal lands or are resource trustees. (See Section 107(f)(1) and (2)
and 1220)-) '
11.6.3 Good Samaritan Provisions
Section 107(d) of CERCLA provides exceptions to liability for those rendering care or advice at
the directbn of an On-Scene Coordinator (OSC) or in accordance with the NCP. A private
party who is not otherwise liable at the site, and provides advice or care at the direction of an
OSC in accordance with the NCP, will be exempt from liability for any costs incurred as a result
of actions or omissions by that party unless those actions or omissbns are negligent.
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11-8 Chapter 11: The Regulatory "Toolbox"
State and local governments are exempt from liability under CERCLA for actions taken in
response to an emergency created by the release or threat of release of hazardous substances
from a facility owned by another person. Such exemption does not cover gross negligence or
intentional misconduct. As with private parties, the state or local government cannot take
advantage of this provision if it is otherwise liable for the release.
11.6.4 Native American Tribes
Section 126 of CERCLA provides that Indian tribes shall be afforded substantially the same
treatment as states with respect to CERCLA's notification, consultation on remedial actions,
information collection, health authorities, and consultation consistent with the National
Contingency Plan. Section 104(d) of .CERCLA also authorizes the Agency to enter into
cooperative agreements with tribes. Section 107 also gives tribes equivalent authority as given
to states and the federal government to recover response costs and damages to natural
resources.
11.7 Limitations
11.7.1 Federally Permitted Release
EPA's ability to address environmental problems at mining and mineral processing sites may be
limited when a release of concern has been granted a permit under a federal government
program listed in Section 101(10). Even though such a release can be addressed under
Section 104 of CERCLA (i.e., EPA may still perform any necessary remediation), EPA's
authority to recover costs for such activities is removed (Section 107Q)) and its authority to
order others to do the work is questionable.
11.7.2 Pollutants and Contaminants
As described above, some contaminants, such as sulfate, do not fall under the definition of
"hazardous substance." These contaminants can be captured under the definition of "pollutant
and contaminant," but the authority afforded the Agency under Section 104 of CERCLA to
address such contaminants is significantly less than that afforded under Section 106 to address
hazardous substances. EPA may not be able to order responsible parties to address pollutants
and contaminants or be able to recover costs incurred in responding to their releases.
11.8 Ability to Integrate with Other Statutes
CERCLA is a powerful tool for investigation and cleanup of mining and mineral processing
sites. Its applicability at mining and mineral processing sites is broad, and can often be used
when other environmental statutes have failed to address environmental problems. CERCLA
also can provide synergistic effects when combined with other statutes because of its 1)
retroactive, joint, and several liability; 2) remedial capabilities through Superfund financing; and
3) site-specific flexibility through risk assessment and ARARs analysis. When evaluatfng the
use of CERCLA at a site also consider integrating its use with other authorities to achieve the
best mix of cleanup tools for each site.
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Chapter 11: The Regulatory "Tooibox" 11-9
11.9 Federal Facilities and Other Federal Issues
CERCLA Section120 subjects federal agencies (e.g. USFS, BLM, NPS, and DOD) to CERCLA
requirements. CERCLA requirements are similar for federal and private faculties; however,
CERCLA Section120 set out certain additiorlalrequirfrrtents applicable to federal facilities. For
example, Section 120 requires that EPA establish the ^Federal Agency Hazardous Waste
Compliance Docket listing federal facilities that are or may be contaminated with hazardous
substances. EPA then evaluates the facilities on the docket and, where appropriate, places
facilities on the NPL. If a federal facility is placed on the NPL, Section120(c)(1) requires the
federal agency that owns or operates the facility to commence an RI/FS withii six months of the
facilities placement on the NPL. Upon completion of the Rl/FS, Section 120(c)(2) requires the
federal agency to enter into an interagency agreement (IAG) with EPA for completion of all
necessary remedial action at the facility. Under CERCLA Section120(e)(4), lAGs must at a
minimum include the selection of the remedy, the schedule for the completion of the remedy
and arrangements for long-term O&M of the facility.
As a matter of practice, EPA and the responsible federal agency often agree to enter into an
IAG during the initial study phase (RI/FS) or just after the placement of a facility on the NPL.
States are encouraged to become signatories to lAGs where possible.
Funding for remedial actions at federal facilities generally must come from the responsible
federal agency's appropriations because, with limited exceptions, CERCLA Section") 11(e)(3)
prohibits the use of Fund money for remedial actions at federal facilities.
Executive Order 12580 delegates and the President's CERCLA authorities among the various
federal agencies. Under EO 12580, DOD and DOE have been delegated most of the
President's Section104 response authorities for releases or threatened releases of hazardous
substances on or from facilities under their "jurisdiction, custody or control". Other federal
agencies have been delegated Section104 authorities for releases or threatened releases of
hazardous substances on or from facilities under their jurisdiction, custody or control that are
not on the NPL. EPA has been delegated the balance of the President's CERCLA response
authorities (except for releases or threatened releases to the coastal zones, Great Lakes
waters, ports or harbors, which are delegated to the Coast Guard). Executive Order 13016
amended EO 12580 to authorize certain federal agencies (including land manager agencies) to
issue administrative orders under Sections 106 and 122 (with EPA concurrence) for releases or
threatened releases at their facilities.
Thus, federal land manager agencies are authorized to address non-NPL mine sites on their
property much in the same way EPA is authorized to address privately owned mine sites.
Including issuing Section106 orders for response actions or performing response actions
themselves and seeking cost recovery from PRPs. Because of the limitation on the use of
Fund money in Section 111 (d)(3), the federal land manager agencies must rely on its own
appropriations. The federal agencies most often associated with these sorts of actions are the
Department of the Interior through the Bureau of Land Management (BLM) and the Department
of Agriculture through the U.S. Forest Service (USFS). Both of these agencies are moving
forward with a variety of programs to identify and characterize abandoned mines and
processing facilities on lands under their jurisdiction. Mining sites often cross boundaries
between federal and private ownership. Such "mixed ownership" sites require the presence of
EPA since, although agencies other than EPA may issue Section 106 orders Tor response
action on federally owned lands. Federal Land Managers will wish to help make decisions in
devising remediation at mixed ownership sites, especially where long-term operation and
maintenance of a remedy may be required. EPA may also wish to explore having federal land
managers undertake some CERCLA enforcement actions using other authorities.
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11-10 Chapter 11: The Regulatory "Toolbox"
Because of their overlapping authorities, appropriate coordination must occur between EPA and
the applicable federal agencies at mining and mineral processing sites. For a site which is
located partly on federal and partly on privately owned land, a Memorandum of Understanding
(MOU) may be used to define specific roles and responsibilities of each agency. In some cases
it may be appropriate under an MOU to divide responsibilities, focusing CERCLA activity only
on certain prescribed units. Whichever administrative vehicle is utilized, it is important to divide
responsiblities in ways that make technical sense and in order to use federal dollars wisely.
11.10 Other Regulatory Tools
CERCLA is undoubtedly the most flexible and useful regulatory tool for addressing
environmental problems at mining sites: CERCLA is not limited to a particular media, such as
water, but it applies to all media; it provides flexible funding for cleanups, through payment for
or direct implementation of cleanups by responsible parties or by the government; and it
provides for the study and implementation of site-specific approaches to environmental
problems. EPA and other federal agencies will often utilize CERCLA when attempting to
address environmental problems at mining sites. However, in certain situations, other
regulatory tools may also be appropriate. These are discussed briefly, and compared to
CERCLA below. A detailed discussion of these authorities is contained in Appendix C of EPA's
National Hardrock M&iing Framework.
11.10.1 Clean Water Act
After CERCLA the Clean Water Act (CWA) is probably the next most widely used regulatory
tool for addressing environmental problems at mining sites. Section 402 of the CWA
authorizes EPA or delegated states to regulate "point source discharges" of "pollutants" to
"waters of the United States." Each discharge must be permitted. Section 404 of the CWA
provides authority for regulating the discharge of "dredged or fill material." Many mine sites
suffer from the uncontrolled discharge of acidified water, which becomes contaminated as it
flows through abandoned mine workings. Section 402, in particular, may be of use as EPA or
states try to control this flow. Under Section 309 of the CWA, EPA or states may proceed
administratively or judicially against "any person" discharging without a permit or in violation of a
permit. Thus, if a mine site is discharging contaminated waters, and if a responsible person
can be identified, EPA or a delegated state may be able to address the problem.
On the other hand, the utility of the CWA as a regulatory tool is limited compared to CERCLA.
Where CERCLA applies to all media, the CWA applies to water only. Further, the CWA
regulates only "discharges" to "waters of the United States" from "point sources." In 1990, EPA
promulgated fie regulatory definition of industrial activity to include inactive mining operations.-
Under the stormwater program, runoff from mining operations requires a permit if it comes into
contact with overburden, raw material, intermediate products, finished product, byproduct, or
waste products located on the site of such operations. Also, action under the CWA to address
water contamination depends on the existence of owner or operator who is responsible for
obtaining a permit.
11.10.2 Resource Conservation and Recovery Act
RCRA governs the management of solid and hazardous wastes under two regulatory tracks.
RCRA Subtitle D addresses "solid" wastes, while Subtitle C addresses "hazardous" wastes. In
October, 1980, Congress excluded from regulation under Subtitle C "solid wastes from the
extraction, beneficiation, and processing of ores arid minerals" until such time as required
studies were completed and reported to Congress. Referred to as the "Bevill amendment," this
provision effectively excludes "extraction" and "beneficiation" .and 20 specific "processing"
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Chapter 11: The Regulatory '.'Toolbox" 11-11
wastes from regulation as "hazardous" wasted. Most processing wastes continue to be
regulated under Subtitle C, provided they meet the requirement set forth in 40 CFR 261.24 for
consideration as "hazardous" wastes, because they exhibit the toxicity characteristic.
Perhaps more useful for dealing with mining* ft/aiies^afe the requirements of Section 7003 of
RCRA. A "miscellaneous" provision under RGRA, Section 7003 allows EPA to address any
"imminent and substantial endangerment to health or the environment" arising from the past or
present handling, storage, treatment, transportation or disposal of any solid waste or hazardous
waste. The release need not be at a facility otherwise subject to RCRA regulation, and its
applicatbn to solid waste as well as hazardous waste makes it available for mining waste
despite the Bevill exclusion. In many respects, Section 7003 order authority is comparable to
orders under Section 106 of CERCLA and may be issued to current or former handlers, owners,
operators, transporters, and generators. EPA may issue an administrative order or seek an
injunction in federal district court to stop the practice causing the danger and/or take any other
action necessary. Violators of an administrative order under Section 7003 may be penalized up
to $5,000 per day. Although the operation of Section 7003 of RCRA is similar to that of
Section 106 of CERCLA, RCRA does not contain fundhg mechanisms allowing for government
funding of cleanups.
11.10.3 Toxic Substances Control Act
The Toxic Substances Control Act (TSCA) allows EPA to regulate the manufacture (including
import), processing, distribution, use, and disposal of chemical substances. Under TSCA, EPA
may require health and environmental effects testing by manufacturers, importers and
processors of chemical substances, which include organic and inorganic substances occurring
in nature, as well as chemical elements. TSCA also authorizes EPA to require record keeping
and reporting of information that is useful for the evaluation of risk, regulate chemical
substances that present an unreasonable risk of injury to health or the environment, take action
to address imminent hazards, require notification to EPA by prospective manufacturers of new
chemicals, and make inspections or issue subpoenas when needed to implement TSCA
authorities.
In practice, the most useful tool under TSCA has been the regulations pertaining to
polychlorinated biphenyls (PCBs) promulgated under Section 6 of TSCA, as codified in 40 CFR
Part 761. The mining industry has traditionally used high levels of PCBs as the dielectrics in
transformers and capacitors, which are commonly found wherever there is a high electrical
power demand. Transformers and capacitors can be found in any phase of surface or
underground mining operations and the ore beneficiation process. PCB equipment has been
replaced in many mines and all mines built after the ban on production of PCB equipment
should no longer be using electrical equipment containing PCBs.
The disadvantages of TSCA at mining sites as compared with CERCLA are that its applicability
is limited, and it contains no funding mechanisms that may be used where a viable responsible
party is not present.
11.10.4 Miscellaneous Requirements
Other federal regulatory requirements which may be of some use for addressing environmental
problems at mine sites include the Clean Air Act, the Emergency Planning and Right to Know
Act, and the Safe Drinking Water Act. These are not discussed here as they are of relatively
limited use to site managers when they are addressing environmental problems at mining sites.
Although not discussed here, these provisions are discussed in detail in Appendix C of EPA's
National Hardrock Mining Framework. In addition to the federal regulations discussed here,
there are numerous State, Tribal, and local regulations that can be utilized by the site manager.
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11-12 Chapter 11: The Regulatory "Toolbox"
11.11 Non-Regulatory Tools
In addition to the federal regulatory tools previously described in this chapter, there are a
number of non-regulatory tools that may be avaflable to the site manager. Non-regulatory
approaches available to address environmental challenges posed by mining are typically
employed to complement existing regulatory programs in addressing mining impacts; however,
there have been some instances where they have been used independently of any regulatory
framework. While current regulatory programs can often be adapted to address the
environmental problems posed by mining, they can be cumbersome, expensive to administer,
and understaffed. Non-regulatory tools have been developed to take advantage of the
incentives created by a backdrop cf enforcement oriented regulatory programs, or to coordhate
these programs to maximize their overall impact. For example, when cleanups precede active
enforcement of regulatory programs they may be easier and less expensive to implement.
While recognizing that each non-regulatory effort is unique, there are certain themes that are
common to the most successful efforts.
The purpose of this discussion of non-regulatory tools include the folbwing:
Illustrate the key traits of effective non-regulatory tools. Sometimes these will be based
on tools that have a regulatory connection, although the emphasis will be on the non-
enforcement aspects of those authorities.
Using specific case examples, point out areas where these tools have filled gaps in the
current regulatory framework.
Highlight model policies and approaches that could be the basis for future regulations or
legislation.
Point out the main limitations or non-regulatory approaches.
While recogniz'ng that each non-regulatory effort is unique, there are certain themes that are
common to the most successful ones, both site specific and non-site specific. They include the
following.
Active participation by principal stakeholders, including a recognition of the environmental
problems and a wiiingness to take on the issues. This typically includes federal, state and local
governments, tribes, industry, citizens, and affected landowners. Participation does not
necessarily mean funding, but it does mean cooperation.
Creative use of limited funding resources, promoting coordination and research on mining
issues. While little public money is specifically earmarked for mine site cleanup, other
programs, such as EPA's CWA Section 319 funds, have been successfully used to fund
portions of cleanup projects. State programs, local contributions, and private funding by
responsible parties have all been tapped for assessment and cleanup projects. Technology
demonstrations have sometimes been used to get seed money to develop a new cleanup
approach. These include the University of Montana's Mining Waste Institute, a variety of
groups comprising the Minhg Information Network, and the Western Governors'Association
(WGA).
Site specific flexibility, in adapting non-regulatory tools to fit the specifics of the site and the
interest of the stakeholders.
Pollution prevention, efforts supported by federal and state agencies, tribes, and other
stakeholders limiting the generation and use of waste materials.
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Chapter 11: The Regulatory "Toolbox" 11-13
Prioritization of cleanup projects, often on a watershed basis, as a way of allocating limited
resources and focusing on worst cases first.
Regulatory discretion as a tool to promote creative problem solving and early implementation
of cleanup projects. For example, having a site listed as a Superfund site might reduce local
involvement.
11.11.1 Key Characteristics of Non-regulatory Tools
Most non-regulatory approaches contain one or more of the following characteristics.
11.11.1.1 Financial
Financial support often comes from a variety of sources when non-regulatory approaches are
used. Funds are often leveraged, and budgets are typically lean. Examples include the
following.
Staff Resources. Non-regulatory approaches often take a large amount of staff time and
energy to implement.
RCRA 7007 and 8001 Grant Funds. Section 7007 funds are grants for a wide range of
training programs, for either states or individuals. Section 8001 funds cover research, training,
and other studies related to solid and hazardous waste. Funds in both of these sections cover
potentially a wide range of projects and have been used extensively to fund mining research
and technical assistance throughout all EPA media program offices as well as the Office of
Enforcement. Funding in recent years has been as high as $2.5 million, in FY 95 it is expected
to be $500,000. In FY 89 and FY 90 most of the money went to support WGA related activities;
now funds are used for a variety of media related projects. Categories of funding typically
include research at the Colorado School of Mines on mine waste, funding to maintain an
environmental network, and funding to regions on mining related projects.
CWA Section 319 Funds. Section 319(h) established a demonstration grant program to assist
states in implementing specific projects to demonstrate effective NPS control projects.
Approximately $1,000,000 per year is spent through this mechanism on inactive mine projects,
with oversight in the EPA Regional offices. Types of activities funded include: education, staff
development, technical assistance, project demonstration, and ground water protection.
Other Federal Agency Funds. These are often used to either supplement EPA funds or to
support specific pieces of a non-regulatory approach or initiative. In some instances land
management agencies have large budgets devoted to mining related programs. These can be
significantly greater than the EPA funds discusses above.
State/Local Partnerships. Although usually smaller in size than federal monies, support from
state and local stakeholders can often fill financial hdes in geographic based approaches.
Voluntary efforts. Good Samaritan work by private parties can contribute a significant amount
towards cleanup of inactive and abandoned mines.
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11-14 Chapter 11: The Regulatory "Toolbox"
11.11.1.2 Institutional
Institutional support is critical for non-regulatory tods to be successful. These hclude the
following.
Interagency Agreements. MOUs, MOAs, and lAGsare all tods that can be used to deal with
the large number of agencies that regulate mining. When used effectively, they can help clarify
roles and streamline the overall regulatory process. For example, as part of the Coeur d'Alene
Restoration Project a MOA between EPA, the State of Idaho and the Coeur d'Alene Tribe was
instrumental in helping reduce differences among the parties and focusing efforts on restoration
goals.
External/Internal teamwork. At a less formal level, interaqency
11-16 Chapter 11: The Regulatory "Toolbox"
NOTICE
This document provides a reference resource to EPA and other staff addressing abandoned
mine sites. The document does not, however, substitute for EPA statutes, regulations and
guidance, nor is it a regulation itself. Thus it cannot impose legally-binding requirements on
EPA, States, or the regulated community, and may not apply to a particular situation based on
the circumstances. EPA may change this reference document in the future, as appropriate.
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Chapter 11: The Regulatory "Toolbox" 11-13
Prioritization of cleanup projects, often on a watershed basis, as a way of allocating limited
resources and focusing on worst cases first.
Regulatory discretion as a tool to promote creative problem solving and early implementation
of cleanup projects. For example, having a site listed as a Superfund site might reduce local
involvement.
11.11.1 Key Characteristics of Non-regulatory Tools
Most non-regulatory approaches contain one or more of the following characteristics.
11.11.1.1 Financial
Financial support often comes from a variety of sources when non-regulatory approaches are
used. Funds are often leveraged, and budgets are typically lean. Examples include the
following.
Staff Resources. Non-regulatory approaches often take a large amount of staff time and
energy to implement.
RCRA 7007 and 8001 Grant Funds. Section 7007 funds are grants for a wide range of
training programs, for either states or individuals. Section 8001 funds cover research, training,
and other studies related to solid and hazardous waste. Funds in both of these sections cover
potentially a wide range of projects and have been used extensively to fund mining research
and technical assistance throughout all EPA media program offices as well as the Office of
Enforcement. Funding in recent years has been as high as $2.5 million, in FY 95 it is expected
to be $500,000. In FY 89 and FY 90 most of the money went to support WGA related activities;
now funds are used for a variety of media related projects. Categories of funding typically
include research at the Colorado School of Mines on mine waste, funding to maintain an
environmental network, and funding to regions on mining related projects.
CWA Section 319 Funds. Section 319(h) established a demonstration grant program to assist
states in implementing specific projects to demonstrate effective NPS control projects.
Approximately $1,000,000 per year is spent through this mechanism on inactive mine projects,
with oversight in the EPA Regional offices. Types of activities funded include: education, staff
development, technical assistance, project demonstration, and ground water protection.
Other Federal Agency Funds. These are often used to either supplement EPA funds or to
support specific pieces of a non-regulatory approach or initiative. In some instances land
management agencies have large budgets devoted to mining related programs. These can be
significantly greater than the EPA funds discusses above.
State/Local Partnerships. Although usually smaller in size than federal monies, support from
state and local stakeholders can often fill financial holes in geographic based approaches.
Voluntary efforts. Good Samaritan work by private parties can contribute a significant amount
towards cleanup of inactive and abandoned mines.
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11-14 Chapter 11: The Regulatory "Toolbox"
11.11.1.2 Institutional
Institutional support is critical for non-regulatory tods to be successful. These include the
following.
Interagency Agreements. MOUs, MOAs, and lAGsare all tods that can be used to deal with
the large number of agencies that regulate mining. When used effectively, they can help clarify
roles and streamline the overall regulatory process. For example, as part of the Coeur d'Alene
Restoration Project a MOA between EPA, the State of Idaho and the Coeur d'Alene Tribe was
instrumental in helping reduce differences among the parties and focusing efforts on restoration
goals.
External/Internal teamwork. At a less formal level, interagency groups are often an effective
means of focusing attention on certain projects or issues. They provide a way for individuals
with expertise to interact. These coalitions are also and important first step in breaking
regulatory impasses. The WGA Mine Waste Task Force is such an example. Within a Region,
internal EPA teams also help focus efforts on mining issues, such as in Regions 8, 9, and 10,
where most of the staff participation on mining teams is voluntary.
Regional and National Initiatives. These are also a useful way of improving communications
and focusing efforts on addressing mining problems. The site specific approaches described in
more detail in Appendix C of EPA's National Hardrpck Mining Framework are all examples of
such initiatives at the regional level.
Outreach. This ranges from detailed outreach to a local community to simply providing on-site
staffing at critical junctures during a remediation. One type of outreach, involving community
based environmental indicators, can provide an important link with strategically significant
technical tool, watershed planning.
11.11.1.3 Technical
Technical assistance. This would include the dedication of either Agency staff or contractor
hours to providing direct help to a stakeholder. This is often an effective tool in working with
other agencies and states.
Analytic methodologies. These can range from predictive tools to well developed monitoring
and testing standards that help make data analysis consistent. Examples include: resource
assessment and goal setting methods, alternatives devebpment, and cost effectiveness
methodologies. One specific example of this is the State of Montana, which has developed an
MRS type system used for priority setting.
Technical demonstration. Technology demonstration efforts have had a couple of roles in
non-regulatory efforts. One is a traditional means of identifying new and effective treatment
technologies. Another is that non-regulatory approaches themselves have been able to attempt
less proven methods than more regulatory, Superfund type approaches to remediation.
Education and Training. Because of the multimedia nature of mining issues, training is often
necessary to bring key players up to speed on technical or regulatory issues. Education efforts
on a more broader scale have been used to highlight and respond to community concerns
regarding the impacts of mining and regulatory activities.
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Chapter 11: The Regulatory "Toolbox" 11-15
Standardization Analysis and Monitoring WlethocK. Different agencies use different
methods for measurement ranging from simple location data to kinetic testing methodologies.
Efforts to standardize this information make priority sitting and monitoring significantly easier.
11.11.2 Other Characteristics ? -
Enforcement Discretion. Where there is a significant enforcement history in connection with
non-regulatory initiative, enforcement discretion is often a factor in helping to build a working
coalition amongst a variety of players.
institutional Controls. These include a variety of approaches, such as deed restrictions and
other local regulations, that can be useful as part of an overall strategy.
11.11.3 Limits
There are limits to what can be accomplished with non-regulatory tools. These would include
the following.
Staff resources. One of the main drawbacks on non-regulatory tools are the large amount of
staff time needed to make them successful. To some extent, though, this may be a matter of
perception only. Although these approaches can require significant staff resources, they can
avoid a much higher resource cost in the future if properly focused.
Enforcement related issues. As a result of the regulatory backdrop for many of these
examples, enforcement and liability can obstruct or delay non-regulatory, cooperative or Good
Samaritan efforts.
Liability concerns. Sometimes private parties are reluctant to take action under a non-
regulatory framework as such effort often do not address potential liability concerns. Efforts are
underway to address these concerns through amendments to the CWA and CERCLA.
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11-16 Chapter 11: The Regulatory "Toolbox"
NOTICE
This document provides a reference resource to EPA and other staff addressing abandoned
mine sites. The document does not, however, substitute for EPA statutes, regulations and
guidance, nor is it a regulation itself. Thus it cannot impose legally-binding requirements on
EPA, States, or the regulated community, and may not apply to a particular situation based on
the circumstances. EPA may change this reference document in the future, as appropriate.
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APPENDIX A
ACRONYM LIST and
GLOSSARY OF MINING TERMS
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Appendix A: Acronym List and Glossary of Mining Terms
(This Page Intentionally Blank)
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A -2 Appendix A: Acronym List and Glossary of Mining Terms
NFS National Park Service
OSC On-Scene Coordinator
OPPTS Office of Prevention Pesticides and Toxic Substances
ORD Office of Research and Development
O&M Operating and maintenance
OSM Office of Surface Mining
OSHA Occupational Safety and Health Act
OSW Office of Solid Waste
OSWER Office of Solid Waste and Emergency Response
OU Operable Units
OW Office of Water
PAHs Poly Aromatic Hydrocarbons
PCBs Polychlorinated Biphenols
PRG Preliminary Remediation Goals
PRP Potentially Responsible Party
QAPP Qualjty Assurance Project Plan
RAGS , Risk Assessment Guidance for Superfund
RAOs Remedial Action Objectives
RCRA Resource Conservation and Recovery Act
RI/FS Remedial Investigation and Feasibility Study
RFS ' RCRA Facility Assessment
RPMs Remedial Project Managers
ROD Record of Decision
SACM Superfund Accelerated Cleanup Model
SAP Sampling and Analysis Plan
SARA Superfund Amendments and Reauthorization Act
SITE Superfund Innovative Technology Evaluation
SDWA Safe Drinking Water Act
SPLC Synthetic Precipitation Leaching Procedure
SVOCs Semi-Volatile Organic Compounds
TAG Technical Assistance Grant
TCE Trichloroethylene
TCLP Toxicity Characteristic Leaching Procedure
TOSC , Technical Outreach Services for Communities
TSCA Toxic Substances Control Act
TMDL Total Maximum Daily Load
TRW Technical Review Workgroup
USFS US Forest Service
USGS U.S. Geological Survey
USCG U.S. Coast Guard
WET California's Waste Extraction Test
XRF X-ray Fluorescence analytical method
VOCs Volatile Organic Compounds
WGA Western Governors' Association
-------
Appendix A: Acronym List and Glossary of Mining Terms A.-3
PLEASE NOTE: use of these terms does not constitute a regulatory determination under either
RCRA or CERCLA. This glossary may only be uses to assist the user and should not be used to
regulatory purposes
Active treatment systems: Systems that require periodic or continual maintenance or upkeep to
maintain system effectiveness. Examples include treatment plants and alkaline chemical addition.
Adit: A nearly horizontal passage from the surface by which a mine is entered and drained.
Aerobic: In the presence of oxygen. Aerobic wetlands are those in which oxidizing processes
dominate.
Alkalinity: Thecapaciiy of water to accept protons (acidity). Alkalinity is imparted to natural waters
by bicarbonate, carbonate, or hydroxide anions.
Alkalinity producing systems: A type of passive treatment system designed to produce neutral
effluent with excess alkalinity. Typically these alkalinity producing systems combine anoxic
limestone drains with anaerobic wetlands.
Alluvial mining: The use of dredges or hydraulic water to extract ore from placer deposits.
Amalgamation: The use of mercury to catch native gold by sorption, forming a liquid "amalgam"
from which the mercury is later removed by distillation.
AMD: Acid mine drainage, characterized by low pH, high sulfate, and high iron and other metal
species.
Anaerobic: In the absence of oxygen. Anaerobic wetlands are those in which reducing processes
dominate.
Anfo: A free running explosive used in mine blasting made of 94% prilled aluminum nitrate and
6% No. 3 fuel oil.
Anionic species: Ions with a negative charge.
Anode: The negative electrode.
Anoxic limestone drain: A type of passive treatment system consisting of a trench of buried
limestone into which acid water is diverted. Dissolution of limestone increases pH and alkalinity.
Anoxic: In the absence of oxygen.
ARD: Acid Rock Drainage. See AMD
Assay: To determine the amount of metal contained in an ore.
Beneficiation: Physical treatment of crude ore to improve its quality for some specific purpose.
Also called mineral processing. RCRA defines beneficiatbn as: restricted to the following activities:
Crushing; grinding; washing; dissolution; crystallization; filtration; sorting; sizing; drying; sintering;
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A-4 Appendix A: Acronym List and Glossary of Mining Terms
palletizing; briquetting; calcining to remove water and/or carbon dioxide; roasting, autoclaving,
and/or chlorination in preparation for leaching; gravity concentration; magnetic separation;
electrostatic separation; flotation; ion exchange; solvent extraction; electrowinning; precipitation;
amalgamation; and heap, dump, vat, tank, and in situ leaching. See 40 CFR 261.4 (b)7 for more
information
Bioreactor: An engineered container filled with untreated waters and organic matter such as hay
or manure which provides suifate-reducing bacteria and a carbon source to sustain the bacteria.
Block Caving: Large massive ore bodies may be broken up and removed by this method with a
minimum of direct handling of the ore required. Generally, these deposits are of such a size that
they would be mined by open-pit methods if the overburden were not so thick. Application of this
method begins with the driving of horizontal crosscuts below the bottom of the ore body, or below
that portion which is to be mined at this stage. From these passages, inclined raises are driven
upward to the level of the bottom of the mass which is to be broken. Then a layer is mined so as
to undercut the ore mass and allow it to settle and break up. Broken ore descends through the
raises and can be dropped into mine cars for transport to the surface. When waste material
appears at the outlet of a raise it signifies exhaustion of the ore in that interval. If the ore extends
to a greater depth, the entire process can be continued by mining out the mass which contained
the previous working passage.
Cathode: The positive electrode.
Cation exchange: A reverseable exchange process, that uses a resin, mineral or other exchange
medium, in which one cation is removed from solution and replaced by another cation displaced
from the exchange medium without destruction of the exchange medium ordisturbance of electrical
neutrality. The process is accomplished by diffusion.
Cationic species: Ions with a positive charge.
Classification: Separation of particles in accordance with their rate of fall through a fluid (usually
water). The hydrocycbne is the most commonly used classification machine.
Clinoptilolite: A common zeolite mineral that has sodium and potassium as the primary cations
and that commonly forms by alteration of natural volcanic glass by ground water or in a saline lake
environment.
Comminution: Crushing and/or grinding of ore by impact and abrasion. Usually, the word
"crushing" is used for dry methods and "grinding" for wet methods. Also, "crushing" usually
denotes reducing the size of coarse rock while "grinding" usually refers to the reduction of the fine
sizes.
Complexing: The chemical process of forming metal complexes.
Concentrate: The concentrate is the valuable product from mineral processing, as opposed to the
tailing, which contains the waste minerals. The concentrate represents a smaller volume than the
original one.
Crushing: See "Comminution".
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Appendix A: Acronym List and Glossary of Mining Terms A - 5
Cut and Fill Sloping: If it is undesirable to leave broken ore in the stope during mining operations
(as in shrinkage stoping), the lower portion of the stope can be filled with waste rock and/or mill
tailings. In this case, ore is removed as soon as it has been broken from overhead, and the stope
filled with waste to within a few feet of the mining surface. This method eliminates or reduces the
waste disposal problem associated with mining as well-as preventing collapse of the ground at the
surface.
Cyanidation: The process of extracting gold and silver by leaching with cyanide (CN-). Cyanide,
usually added in the form of a salt (e.g.., NaCN, KCN), dissolves gold by the following reaction:
4Au + 8CN-+ O2 + 2H2O = 4Au(CN)2- + 4OH-
Cyclone (hydrocyclone): A classifying (or concentrating) separation machine into which pulp is
fed so as to take a circular path. Coarser and heavier fractions of solids report at the apex of a
long cone while the finer particles overflow from the vortex.
Drift: A horizontal mining passage underground. A drift usually follows the ore vein, as
distinguished from a crosscut, which intersects it.
H
Eh: The redox or oxidation potential. A measure of the ability of a natural environment to bring
about any oxidation or reduction process by supplying electrons to an oxidizing agent or accepting
electrons from a reducing agent.
Extraction: The process of removing ore from the ground.
Extractive metallurgy: The processes of chemically separating the valuable, metal from its
mineral matrix (ore or concentrate) to produce the pure metal. Includes the disciplines of
hydrometallurgy and pyrometallurgy.
Ferric iron: Iron present in its oxidized state, with an ionic charge of +3.
Ferrous iron: Iron present in its reduced state, with an ionic charge of +2.
Flotation: Separation of minerals based on the interfacial chemistry of the mineral particles in
solution. Reagents are added to the ore slurry to render the surface of selected minerals
hydrophobic. Air bubbles are introduced to which the hydrophobic minerals attach. The selected
minerals are levitated to the top of the flotation machine by their attachment to the bubbles and into
a froth product, called the "flotation concentrate." If this froth carries more than one mineral as a
designated main constituent, it is called a "bulk float". If it is selective to one constituent of the ore,
where more than one will be floated, it is a "differential" float. The remaining slurry left after
flotation is called the "flotation tailing." Flotation is the dominant method of mineral concentratbn
currently in use.
Fluvial: Of or pertaining to rivers.
Flux: A component intentionally added to high temperature processing to modify properties (e.g.,
melting point, viscosity, chemical properties) of the slag.
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A -6 Appendix A: Acronym List and Glossary.of Mining Terms
Gangue: The fraction of ore rejected as tailing in a separating process. It is usually the valueless
portion, but may have some secondary commercial use.
Grade: Percentage of a metal or mineral composition in an ore or processing productfrom mineral
processing.
Gravity separation: Exploitation of differences in the densities of particles to achieve separation.
Machines utilizing gravity separation include jigs and shaking tables.
Grinding: See "Comminution".
Hydrometallurgy: A type of extractive metallurgy utilizing aqueous solutions/solvents to extract
the metal value from an ore or concentrate. Leaching is the predominant type of hydrometallurgy.
Ion: An atom, group of atoms, or molecule that has acquired a net electric charge by gaining or
losing electrons from an initially electrically neutral configuration.
Iron hydroxide: A chemical compound composed of iron cation and a hydroxide (oxygen plus
hydrogen) anion, with the chemical formula Fe(OH)3. It is a common precipitate in acidic
environments, with a yellowish, orangish or reddish coloration.
Layered base amendments: Alkaline (base) materials that are interlayered with acid generating
materials in order to provide a measure of neutralizing capacity.
Liberation: Freeing, by comminution, of particles of specific mineralfrom their interlock with other
constituents of the ore.
Limestone: A sedimentary rock formed by chemical precipitation from sea water or fresh water
that is composed primarily of the mineral calcite (calcium carbonate).
Lode: An unusually large vein or set of veins containing ore minerals.
Longwall mining: In level, tabular ore bodies it is possible to recover virtually all of the ore by
using this method (in the United States, only coal is known to have been mined using longwall
methods). Initially, parallel drifts are driven to the farthest boundary of the mine area. The, ore
between each pair of drifts is then mined along a continuous face (the longwall) connecting the two
drifts. Mining proceeds back toward the shaft or entry, and only enough space for mining activities
is held open by moveable steel supports. As the longwall moves, the supports are moved with it
and the mined out area is allowed to collapse. Various methods can be used to break up and
remove the ore. In many cases, the rock stresses that are caused by the caving of the
unsupported area aids in breaking the material in the longwall face.
Magnetic separation: Use of permanent or electro-magnets to remove relatively strong ferro-
magnetic particles from para- and dia-magnetic ores.
Matte: An impure metallic sulfide product obtained from the smelting of sulfide ores of metals such
as copper, lead, and nickel.
Metal complexes: An ion consisting of several atoms including at least one metal cation.
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Appendix A: Acronym List and Glossary of Mining Terms A-7
Metallurgy: The science and art of extracting metals from their ores, refining them, and preparing
them for use. Metallurgy consists of three major disciplines: mineral processing metallurgy,
extractive metallurgy, and physical metallurgy.
Microbial mat: A naturally occurring mat of organic matterfound in wetland environments, typically
composed predominantly of blue-green algae.
Mill: Includes any ore mill, sampling works, concentration, and any crushing, grinding, or
screening plant used at, and in connection with, an excavation or mine.
Mine: An opening or excavation in the earth for the purpose of extracting minerals.
Mineral: A naturally occurrhg, solid, inorganic element or compound, with a definite composition
or range of compositions, usually possessing a regular internal crystalline structure.
Mineral processing: Preparation of ores by physical methods. A subcategory of metallurgy.
Methods of mineral processing include comminution, classification, flotatbn, gravityseparation, etc.
Native metal: A natural deposit of a metallic element in pure metallic form, not combined as a
mineral with other elements.
Open Stope: In competent rock, it is possible to remove all of a moderate sized ore body,
resulting in an opening of considerable size. Such large, irregularly-shaped openings are called
stopes. The mining of large inclined ore bodies often requires leaving horizontal pillars across the
slope at intervals in order to prevent collapse of the walls.
Ore: A natural deposit in which a valuable metallic element occurs in high enough concentration
to make mining economically feasible.
Overburden: Material of any nature, consolidated or unconsolidated, that overlies a deposit of ore
that is to be mined.
Oxidizing: Increasing in oxidation number (valence charge). The process of oxidation involves a
loss of electrons.
Oxyhydroxides: Chemical compounds that contain one or more cations bonded to both oxygen
and hydroxide (OH) anfons.
Passive treatment systems: Systems that do not require periodic or continual mantenance or
upkeep to maintain system effectiveness. Examples include aerobic or anaerobic wetlands, anoxic
limestone drains, open limestone channels, alkalinity producing systems, and limestone ponds.
pH: The negative logarithm of the hydrogen ion concentration, in which pH = -log [H+]. Neutral
solutions have pH values of 7, acidic solutions have pH values less than 7, and alkaline solutions
have pH values greater than 7.
Placer: A sedimentary deposit of unconsolidated material (usually gravel in river beds or sand
dunes) containing high concentrations of a valuable mineral or native metal, usually segregated
because of its greater density.
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A-8 Appendix A: Acronym List and Glossaryof Mining Terms
Porous reactive walls: Trenches constructed to intercept contaminated ground water and which
are filled with materials such as activated charcoal that sorb or precipitate metals from solution.
Pyrometallurgy: A type of extractive metallurgy where furnace treatments at high temperature
are used to separate the metal values from an ore or concentrate. The waste product is removed
as slag and/or gases. Smelting and refining are common pyrometallurgical processes.
Reducing: Decreasing in oxidation number (valence charge). The process of reduction involves
a gain of electrons. .
Reduction-oxidation potential: The redox potential or Eh.
Refining: A high temperature process in which impure metal is reacted with flux to reduce the
impurities. The metal is collected in a molten layer and the impurities in a slag layer. Refining
results in the production of a marketable material.
Riparian: Pertaining to the bank of a natural watercourse.
Roasting: The oxidation of ore or concentrate (usually of sulfide concentrates) at an elevated
temperature to obtain metal oxides. The material is not melted. Roasting is usually used to
change metallic compounds into forms more easily treated by subsequent processing.
Room and Pillar: This method is suitable for level deposits that are fairly uniform in thickness.
It consists of excavating drifts (horizontal passages) in a rectilinear pattern so that evenly spaced
pillars are left to support the overlying material. A fairly large portion of the ore (40%-50%) must
be left in place. Sometimes the remaining ore is recovered by removing or shaving the pillars as
the mine is vacated, allowing the overhead to collapse or making future collapse more likely.
Sedges: Any of numerous plants of the family Cyperaceae, resembling grasses but having solid
rather than hollow stems.
Sequential extraction: A chemical extraction process in which chemical species are removed from
solution for analysis in a sequential manner using laboratory techniques that do not affect the
concentrations of the constituents remaining in solution.
Shaft: An excavation of limited area compared with its depth, made for finding or mining ore or
coal, raising ore, rock or water, hoisting and lowering men and materials, or ventilating
underground workings.
Shrinkage Stoping: In this method, mining is carried out from the bottom of an inclined or vertical
ore body upwards, as in open sloping. However, most of the broken ore is allowed to remain in
the stope in order both to support the stope walls and to provide a working platform for the
overhead mining operations. Ore is withdrawn from chutes in the bottom of the stope in order to
maintain the correct amount of open space for working. When mining is completed in a particular
stope, the remaining ore is withdrawn, and the walls are allowed to collapse.
Slag: A mixture of oxides (sometimes halides) of metals or nonmetals formed in the liquid state
at high temperatures. A flux is usually added to encourage slag production, where the slag
represents the undesirable (waste) constituents from smelting and refining an ore or concentrate.
-------
Appendix A: Acronym List and Glossary of Mining Terms A - 9
Smelting: Obtaining a metal from an ore or concentrate by melting the material at high
temperatures. Fluxes are added that in the presence of high temperatures, reduce the metal oxide
to metal resulting in a molten layer containing the heavy metal values and form a slag layer
containing impurities. Smelting is usually performed in blast furnaces.
Sorption: The process of sorbing as by adsorption or absorption.
Spoil: Debris or waste material from a mine.
Square-set Sloping: Ore bodies of irregular shape and/or that occur in weak rock can be mined
by providing almost continuous support as operations progress. A square set is a rectangular,
three-dimensional frame usually of timber, which is generally filled with waste rock after
emplacement. In this method, a small square section of the ore body is removed, and the space
created is immediately filled by a square-set. The framework provides both lateral and vertical
support, especially after being filled with waste. Use of this method may result in a major local
consumption of timber and/or other materials utilized for construction of the sets.
Stope: An excavation in a
extracting ore.
mine, other than development workings, made for the purpose of
Sublevei Caving: In this method, relatively small blocks of ore within a vertical or steeply sloping
vein are undercut within a stope and allowed to settle and break up. The broken ore is then
scraped into raises and dropped into mine cars. This method can be considered as an
intermediate between block carving and top slicing.
Substrate: An underlayer. In passive treatment systems this refers to a layer of organic or other
matter that underlies ponded acidic water.
Taconite: A chemical precipitate sedimentary rock composed of iron-bearing chert and which can
serve as an ore material for iron.
Tailings:
etc.).
Residue from milling processes (e.g., flotation tailings, gravity tailings, leach tailings,
Top Slicing: Unlike the previously described methods in which mining begins at the bottom of an
ore body and proceeds upward, this procedure involves mining the ore in a series of slices from
the top downward, first removing the topmost layer of the ore and supporting the overhead with
timber. Once the top layer of an area is completely removed, the supports are removed and the
overlying material allowed to settle onto the new top of the ore body. The process is then repeated,
so that as slices of ore are removed from the ore body, the overburden repeatedly settles.
Subsequent operations produce an ever- thickening mat of timber and broken supports. This
method consumes major quantities of timber.
Vein: A mineralized zone having a more or less regular development in length, width, and depth
to give it a tabular form.
Wetlands: A lowland area such as a marsh or swamp that is saturated with moisture. They can
be natural features of an environment or engineered impoundments.
Zeolite: A group of hydrous aluminosilicate minerals containing sodium, calcium, potassium or
other alkali or alkaline earth elements, which typically have an open crystal structure. These
minerals are widely used in chemical processes for their cation exchange capabilities.
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APPENDIX B
ACID MINE DRAINAGE
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Appendix B: Acid Mine Drainage
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Appendix B: AcVd Mine Drainage
Appendix §
Acid Mine Drainage
Table of Contents
B.1 Introduction
B.2 Description
B.3 Environmental Effects .....
B.4 Contacts and References .. .
B.5 AMD Annotated Bibliography
B-1
B-1
B-3
B-4
B-5
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Appendix B: Acid Mine Drainage
(This Page Intentionally Blank)
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Appendix B
Acid Mine Drainage
B.1 Introduction
Acid mine drainage (AMD), also called acid rock drainage (ARD), is a natural occurrence
resulting from the exposure of sulfur and iron bearing materials to erosion and weather.
Percolation of water through these materials results in a discharge with low pH and high metals
concentration. Although AMD is naturally occurring, mining activities may greatly accelerate its
production. AMD production is accelerated since mining exposes new iron and sulfide surfaces
(e.g, underground mine walls, open pit walls, and overburden and mine waste piles) to oxygen.
As such, AMD is one of the primary environmental threats at mining sites.
To efficiently remediate mining sites, project managers must understand the formation of AMD
and those factors that influence its quality and quantity, such as the interaction of sulfide
minerals, air, water, and micro-organisms. This section has been added to introduce the
project manager to these issues.
B.2 Description
AMD results from the oxidation of sulfide minerals inherent in some ore bodies and the
surrounding rocks. Iron sulfide minerals, especially pyrite (FeS2) and also pyrrhotine (FeS)
contribute the most to formation of AMD. Oxygen (from air or dissolved oxygen) and water (as
vapor or liquid) which contact the sulfide minerals directly cause chemical oxidation reactions
which result in the production of sulfuric acid. The primary reactions associated with pyrite are
described below.1
Pyrite is initially oxidized by atmospheric oxygen producing sulfuric acid and ferrous iron (Fe2+)
according to the following reaction:
FeS2 + 7/2 O2 + H2O > Fe2+ + 2SO42- + 2H+ (1)
\
Fe2+ + 1/4 O2 + H+ > Fe3+ + Ya H2O (2)
The ferrous iron may be further oxidized by oxygen releasing more acid into the
environment and precipitating ferric hydroxide.
Fe2+ + 1/4 O2 + 5/2 H2O > Fe(OH)3 + 2H+ (3)
As acid production increases and the pH drops (to less than 4), oxidation of pyrite by
ferric iron (Fe3+) becomes the main mechanism for acid production.
FeS2 + 14Fe3+ + 8H2O > 15Fe2+ + 2SO42- + 16H+ (4)
Singer. P.C. and W. Strumm. 1970. Acid Mire Drainage: the rate-determining step. Science 167:1121-1123.
-------
B-2 Appendix B: Acid Mine Drainage
This reaction is catalyzed by the presence of Thiobacillus ferrooxidans. This bacterium
accelerates the oxidatbn of ferrous iron into ferric iron (reaction 2) by a factor of 106:1. The
sulfuric acid produced in the above reactions increases the solubility of other sulfide minerals in
the solid surfaces. Ferric iron in acidic solutbn can oxidize metal sulfides per the following
reaction:
2Fe3+ > M2+-. .+ S + 2Fe2+
where MS = metal sulfide (galena PbS, sphalerite, ZnS, etc.)
(5)
Metals commonly solubilized from sulfides in AMD include aluminum, copper, lead, manganese,
nickel, and zinc. Metals in the form of carbonates, oxides, and silicates may also be mobilized,
often aided by biological catalysts. AMD may also leach uranium, thorium, and radium from
mine wastes and tailings associated with uranium mining operations. The most common metal
in AMD is iron in the form of soluble ferrous ions, ferrous hydroxide (Fe(OH)2), ferrous sulfate,
and ferric sulfate, as well as suspended insoluble ferric hydroxide precipitate. The iron
hydroxides give AMD a red to orange color.2
The rates of the reactions associated with AMD have important implications, as they influence
the quality (pH and metals content) and quantity of AMD produced. The rate of AMD formation
depends on several factors, including the presence of microorganisms, the type of the sulfide
and non-sulfide minerals present, particle size of the minerals, pH, temperature, and the
amount of oxygen present.
The presence of iron-oxidizing microorganisms as catalysts affects the rate of AMD forming
reactions. These bacteria are indigenous to many environments including sulfide ore bodies.
As discussed above, the iron oxidizing autotrophic bacteria, T. ferrooxidans, greatly increases
the oxidation of ferrous to ferric iron, which causes reactbn 4 to quickly proceed. Reaction 4
produces 16 equivalents of hydrogen ions further lowering pH and causing more ferric iron to
be oxidized. At low pH levels (pH 2 to 4) these bacteria thrive and multiply, further increasing
reaction rates. Sulfide-oxidizing bacteria, such as T. thiooxidans may also increase AMD
formation, although to what extent is less well-known.
Mineral sulfides vary in their reactivity. This is due to the physical and chemical characteristics
of the various sulfide minerals. For example some metal sulfides (i.e., copper, lead, and zinc)
have a tendency to form low solubility minerals which encapsulate them and prevent further
oxidation. The crystal structure of the sulfide minerals is an important factor for two reasons:
(1) certain crystalline structures are more stable and resist weathering (oxidation); and (2) due
to the increased surface area, smaller crystals react faster.3
The. rate of AMD formation depends upon the particle size and surface area of rocks containing
the sulfide minerals. Smaller particles have increased surface area that can contact the
' duMond. Mike. "NewMexico Mne Drainage Treatment" State of New Mexico Energy. Minerals and Natural Resources Department.
Albuquerque. New Mexico. 1987.
' Steffen. Robertson, and Kirsten Inc.. Acid Rock Drainage Draft Technical Guide, Volume 2- Summary Guide, December 1989.
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Appendix B: Acid M ine Drainage B-3
weathering agents. Therefore, rock tailings (very fine particles) will weather faster than large
boulders. Rates of weathering and production of AMD are dramatically increased in processed
materials (e.g, crushed tailings from mineral processing or leaching), due to the increased
amount of surface area.
The rate of AMD formation is also dependent on pH and temperature. The chemical reaction
rate is higher at low phi because the solubility of the metals increases and biological oxidation
peaks at a pH of about 3.5. Therefore, it is generally true that as more sulfuric acid is released
and the pH decreases, more leaching occurs. Both the chemical and biological reaction rates
also increase with increased temperature. This is because of increased solubility of metal
species and increased biological activity at higher temperatures.
It is apparent from the above discussion that the production of AMD is complicated. Due to the
many factors that influence AMD, the short-term and long-term quality and quantity produced
may be difficult to characterize or predict. Section A.4.2 of this document discusses methods
for characterizing the production of AMD from waste solids (sources) associated with mining
processes.
B.3 Environmental Effects
As discussed above, AMD introduces sulfuricacid and heavy metals into the environment. The
environment can naturally assimilate some AMD through dilution, biological activity, and
neutralization, although its capacity to treat AMD may be limited. When this treatment capacity
is exceeded, drainage and surface water flowing out of mining areas can be very acidic and
contain elevated concentrations of metals. The metal-laden acidic drainage and surface water
can lead to ground water contamination.
The ability of the receiving environment to assimilate AMD will depend on site specific
conditions such as drainage patterns and dilution, biological activity, and neutralizing capacity of
the ore, waste material, tailings, and/or surrounding soils. Drainage patterns and dilution
depend largely on the climate and topography of a site. Naturally occurring biological activity
can attenuate the metals concentration by adsorption and precipitation of some metal species
such as sulfates.
Neutralization is the consumption of acidity in which hydrogen ions are consumed according to
the following reactions:
CaCOS + H+
HCO3- + H+
> Ca2+ + HCO3-
> H2O +CO2
(6)
(7)
The neutralization capacity of a soil depends largely on the presence of naturally occurring, acid
consuming minerals. The most common mineral is caicite (CaCOS), a major constituent of
limestone, and dolomite (CaMg(CO3)2). Other neutralizing minerals include other carbonates
of iron and magnesium and aluminum and iron hydroxides. As neutralization occurs, metals
precipitate because of decreased solubility at higher pH.
The impact of AMD can increase over time if the neutralizing capacities of the soil are depleted.
This may occur if the neutralizing minerals have a tendency to form crusts of precipitated salts
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B-4 Appendix B: Acid Mine Drainage
or gypsum which inhibits further reactbn, or if the neutralizing minerals are depleted through
numerous reactions with AMD. The impact of AMD can also change if the rates of AMD
formation change due to the alteration of site conditions. For these reasons, there is often a
time lag after mining activities begin until AMD is detected. The times can range from 1 to 10 or
more years; AMD may not be detected until after surface reclamation occurs. Acid generation,
once it begins, is difficult to control, often accelerates, and can persist for centuries.
AMD may be compounded by othertproblems caused by mining activities. Chemicals or
petroleum products used in equipment and vehicle maintenance can pollute mining sites. Heap
leaching technologies utilize cyanide to extract goid, and the failure of liners can introduce
cyanide into the environment. In addition, mining often leads to higher erosion rates and
increased dissolved salts, sediment loads, and turbidity of run-off. Radionuclides can also be
leached out of the rock. All of these contaminants, as wel as the heavy metals mentioned
earlier can enter the surface water and the ground water. These contaminants, in addition to
the acidic run-off, must all be considered when treating AMD.
If site conditions are conducive to AMD formation and the capacity to assimilate AMD has been
exceeded, environmental impacts can be quite severe. Impacts depend on the nature (strength
and volume) of the AMD and the proximity of aquatic resources. Impacts can include lowering
of water quality, alteration of aquatic and terrestrial ecosystems, potential destruction of aquatic
habitats, and, if the site is near human residences, contamination of drinking water supplies.
Impacts are far reaching, are of concern to regulatory decisionmakers, and must be addressed
during cleanup actions. '
B.4 Contacts and References
Appendix B of this Manual is an annotated bibliography of passive acid mine drainage treatment
technologies. EPA regional and other Federal Land Management Agency contacts with
expertise in acid mine drainage prediction, analysis, and remediation, can be found in Appendix
L The remainder of this document is an annotated bibliography of acid mine dra'nage
references.
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Appendix B: Acid Mine Drainage B-5
B.5 AMD Annotated Bibliography
Ackman, Terry E. and R.L.P. Kleinmann. "In-Line Aeration and Treatment of Acid Mine
Drainage," Avondale, MD, U.S. Dept. of the Interior, Bureau of Mines, 1984.
Reference not available.
Ackman, Terry E. "Sludge Disposal from Acid Mine Drainage Treatment," Avondale, MD, U.S.
Dept. of the Interior, Bureau of Mines, 1982.
Reference not available.
Aljoe, W.W. and J.W. Hawkins, 1991. "Hydrologic Characterization and In-Situ Neutralization
of Acidic Mine Pools in Abandoned Underground Coal Mines," in Proceedings Second
International Conference on the Abatement of Acidic Drainage, September 16-18, 1991,
Montreal, Canada, Volume 1, pp.69-90.
Reference not available.
Alpers, Charles N. and Blowes, David W., 1994. Environmental Geochemistry ofSulfide
Oxidation, ACS Symposium Series 550, American Chemical Society, Washington, D.C.
Contains several papers on acid mine drainage. Reference not available.
Altringer 1991. Altringer, P.B., Lien, R.H., Gardner, K.R., Bidogicai and Chemical Selenium
Removal from Precious Metals Solutions, proceedings of the Symposium on Environmental
Management for the 1990s, Denver, Colorado, February 25-28,1991.
Reference not available.
Balistrieri, Laurie S., 1995. Impacts of acid drainage on wetlands in the San Luis Valley,
Colorado, in USGS Mine Drainage Newsletter, No. 3, March, 1995,
http://water.wr.usgs.gov/mine/mar/luis.html.
Describes metal accumulation in sediments of a natural wetland receiving AMD from the
Summitville gold mine. The wetland, located in the Alamosa River system, exhibits increased
levels of Cu, Cr, and Zn.
Batai, Wafa, Laudon, Leslie S., Wildeman, Thomas R., and Mohdnoordin, Noorhanita, 1988.
Bacteriological tests from the constructed wetland of the Big Five Tunnel, Idaho Springs,
Colorado, in Proceedings of the U.S. EPA's Forum on Remediation ofCERCLA Mining Waste
Sites, April 25, 1989, Ward, Colorado, p. 134-148.
Describes variations in the types and amounts of bacteria found in three different
substrate'materials in constructed wetland test cells following two months of AMD flow through
the cells.
Bhole, A.G., 1994. Acid mine drainage and its treatment, in Proceedings of the International
Symposium on the Impact of Mining on the Environment, Problems and Solutions, A.A.
Balkema, Rotterdam, p. 131-142.
Reference not available.
Bikerman, Jacob Joseph, et al. "Treatment of Acid Mine Drainage" prepared by Horizons Inc.
for Federal Water Quality Administration, Dept. of the Interior. Washington: for sale by the
Superintendent of Documents, U.S. Government Printing Office, 1970.
Reference not available.
-------
B-6 Appendix B: Acid Mine Drainage
Bituminous Coal Research, Inc.. "Studies on Limestone Treatment of Acid Mine Drainage;
Optimization and Development of Improve Chemical Techniques for the Treatment of Coal
Mine Drainage." Washington: Federal Water Pollution Control Administration; for sale by the
Superintendent of Documents, U.S. Government Printing Office, 1970.
Reference not available.
Blowes, D.W., et al. "Treatment of Mine Drainage Using In Situ Reactive Walls," in
Proceedings of the Sudbury '95 Conference, Mining and the Environment. May 28-June 1
1995, Sudbury, Ontario. Vol 3, pp. 979-987, 1995.
Reference not available.
Blowes, D.W., Ptacek, C.J., Waybrant, K.R., and Bain, J.G., 1995. In situ treatment of mine
drainage using porous reactive walls, Proceedings of the BIOMINETEleventh Annual Meeting
January, 1995, Ottawa, Ontario, pp. 119-128.
Describes a system for treating acidified waters that contaminate shallow ground water
by installing screens of organic carbon in an excavated portion of the aquifer. Various carbon
sources were tested down-gradient from mine tailings at Sudbury, ON. The reactive walls
induce bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. Pilot
studies show Fe and SO4 concentrations decreased dramatically while pH and alkalinity
increased.
Blowes, D.W., et al. 1994. In situ treatment of mine drainage water using porous reactive wails.
In: The "New Economy" Green Needs and Opportunities, Environment and Energy Conference
of Ontario, November 15 & 16, 1994, Toronto, Ontario. (Manuscript distributed on diskette.)
Boling, S.D. and Kobyfinski, E.A., 1992. Treatment of metal-contaminated acidic mine
drainage, in 47" Purdue Industrial Waste Conference Proceedings, Lewis Publishers, Chelsea
Ml, p. 669-676.
Reference not available.
Bolis, Judith L., 1992. Bench-scale Analysis of Anaerobic Wetlands Treatment of Acid Mine
Drainage, Unpubl. M.S. thesis, Colorado School of Mines, Golden, CO, 116 pp.
Experimental tests of high-alkalinity organic substrates to evaluate anaerobic treatment
of AMD from the Big Five Tunnel, National Tunnel and Quartz Hill Tunnel in Clear Creek, CO.
Results showed that removal of Cu, Zn, Fe, and Mn exceeded 99 percent and that treatment
raised pH from 2.5-5.6 to greater than 7.0. Experimental results were used to calculate
loadings and can be used in the design of pilot-scale or full-scale wetlands.
Borek S. L., T. E. Ackman, G. P. Watzlaf, R. W. Hammack, J. P. Lipscomb, 1991, "The
Long-Term Evaluation of Mine Seals Constructed in Randolph County, W.V. in 1967," in
Proceedings Twelfth Annual West Virginia Surface Mine Drainage Task Force Symposium
April 3-4,1991, Morgantown, West Virginia.
Reference not available.
Boult. S., Collins, D.N., White, K.N., and Curtis, C.D., 1994. Metal transport in a stream
polluted by acid mine drainage -The Afon Goch, Anglesey, UK, Environmental Pollution v 84
p. 279-284. '
Studies the natural precipitation of metal complexes in a stream contaminated by acid
drainage (pH=2.3) from metal mines caused by the inflow of neutral tributary waters. Discusses
implications for the management and remediation of polluted stream systems.
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Appendix B: Acid M ine Drainage B-7
Bowders, J. and E. Chiado, 1990," Engineering Evaluation of Waste Phosphatic Clay for
Producing Low Permeability Barriers," in Proceedings 1990 Mining and Reclamation
Conference and Exhibition, Volume 1, 11-18pp, West Virginia University.
Reference not available.
Brady, K. B., M. Smith, R. Beam and C. Cravotta III, 1990, "Effectiveness of Addition of Alkaline
Materials at Surface Coal Mines in Preventing and Abating Acid Mine Drainage: Part 2 Mine
Site Case Studies," in Proceedings .of the 1990 Mining and Reclamation Conference and
Exhibition, Volume 1, 227-242pp, West Virginia University.
Reference not available.
Brady K.B., J.R. Shaulis and V.W. Sekma, 1988, "A Study of Mine Drainage Quality and
Prediction Using Overburden Analysis and Paleoenvironmental Reconstructions, Fayette
County, Pennsylvania," in Conference Proceedings, Mine Drainage and Surface Mine
Reclamation, U.S. Bureau of Mines Information Circular 9183, 33-44pp.
Reference not available.
Brodie, G., et al. "Passive Anoxic Limestone Drains to Increase Effectiveness of Wetlands Acid
"Drainage Treatment Systems," Proceedings: 12th Annual NAAMLP Conference, Returning
Mined Land to Beneficial Use, Breckinridge, Colorado, September 16-20, 1990.
Reference not available.
Brodie, G.A., 1993. Staged, aerobic constructed wetlands to treat acid drainage: Case history
of Fabius impoundment 1 and overview of the Tennessee Valley Authority's program, in
Moshiri, Gerald A., ed, Constructed Wetlands for Water Quality Improvement, Lewis
Publishers, Boca Raton, p. 157-165.
Reviews the success of 12 wetland systems operated byTVA and discusses the quality
of effluent from impoundment 1, which has been in operation since 1985.
Brodie, G.A., Britt, C.R., Tomaszewski, T.M., and Taylor, H.N., 1993. Anoxic limestone drains
to enhance performance of aerobic acid drainage wetlands: Experiences of the Tennessee .
Valley Authority, in Moshiri, Gerald A., ed., Constructed Wetlands for Water Quality
Improvement, Lewis Publishers, Boca Raton, p. 129-138.
Reviews the effectiveness of anoxic limestone drains in increasing alkalinity to prevent
pH decreases due to Fe hydrolysis.
Brodie, Gregory A., Hammer, Donald A., and Tomljanovich, David A., 1989. Treatment of acid
drainage with a constructed wetland at the Tennessee Valley Authority 950 Coal Mine, in
Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment, Lewis Publishers,
Ann Arbor, Ml, p. 201-209.
• - Reviews the design, construction, and success of a constructed wetland to treat acidic
drainage from impoundment 3 at the 950 coal mine in AL.
Brodie, Gregory A., Hammer, Donald A., and Tomljanovich, David A., 1988. An evaluation of
substrate types in constructed wetlands acid drainage treatment systems, in U.S. Bureau of
Mines, Mine Drainage and Surface Mine Reclamation, Volume I: Mine Water and Mine Waste,
U.S. Bureau of Mines information Circular 9183, p. 389-398.
Experimentally investigated the effectiveness of 5 substrate types (natural wetland,
acidic wetland, clay, mine spoil, and river pea gravel) in mitigating acidic drainage from the
Fabius coal mine (AL). Study showed that substrate type is less important than the plant-soil-
microbe complex that developed in each cell.
-------
B-8 Appendix B: Acid Mine Drainage
Brookhaven Natbnai Laboratory, Dept of Applied Science. "Treatment of Acid Mine Drainage
by Ozone Oxidation." Washington: EPA Water Quality Office; for sale by the Superintendent
of Documents, U.S. Government Printing Office, 1970.
Reference not available.
Brooks 1992. Reclamation of the Timberline Heap Leach: Tooele County, Utah, USDI Bureau
of Land Management, Technical Note #386, by Steven J, Brooks, 1992.
Reference not available. .
Burnett, MacKenzie and Skousen, Jeffrey G., 1995. Injection of limestone into underground
mines for AMD control, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine Drainage:
Control & Treatment, 2"* edition, National Mine Land Reclamatbn Center, p. 357-362. -(
Describes a project in which a coal mine portal was sealed and backfilled with
limestone. Initially, the seal reduced water flow, increased pH of the remaining effluent, and
created net alkaline effluent with reduced Fe and Al concentrations. Subsequent high flows
changed flow paths so that water no longer contacts the limestone and escapes untreated.
Cambridge, M., 1995. Use of passive systems for the treatment and remediation of mine
outflows and seepages, Minerals Industry International, No. 1024, p. 35-42.
A review of the potential uses of the passive systems available and of their effectiveness
in preventing long-term environmental damage. Cites case studies of the treatment systems
used at the Wheal Jane and Consolidated copper-tin mines (Cornwall, England). Includes a
discussion of general principles that may affect the long-term development of acidity.
Camp, Dresser & McKee, Inc., 1991. Clear Creek Phase II Feasibility Study Report, prepared
for the Colorado Department of Health, Hazardous Materials and Waste Management Division,
Denver, CO, vol. 1, p. 3-77 to 3-179.
Contains sections on passive treatment and combined passive and active systems for
treating metaHaden AMD from precious metal mines in the Clear Creek drainage of Colorado.
Passive treatment technologies include cascade aeration to promote precipitation of iron
compounds and wetland treatment in aerobic and anaerobic environments to reduce metal and
sulfur contents. Passive treatment designs are discussed for the Argo Tunnel, Big Five Tunnel,
National Tunnel, Burleigh Tunnel, Rockford Tunnel, Gregory Incline, Quartz Hill Tunnel, and
McClelland Tunnel. Discusses designs that incorporate disposal of precipitated metals in
accordance with RCRAguidelines and for/n situ fixation of precipitated metals. Active
treatment includes chemical precipitation of metals. Considers treatment of surface and ground
waters.
Caruccio F. T. and G. Gediel, 1989, "Water Management Strategies in Abating Acid Mine
Drainage - Is Water Diversion Really Beneficial?," in Proceedings 1989 Multinational
Conference on Mine Planning and Design, University of Kentucky, Lexington, Kentucky.
Reference not available.
Catalytic, Inc. "Neutradesulfating Treatment Process for Acid Mine Drainage," prepared for the
U.S. Environmental Protection Agency; for sale by the Superintendent of Documents, U.S.
Government Printing Office, 1971.
Reference not available.
-------
Appendix B: Acid M ine Drainage B-9
Chapman, B.M, Jones, D.R.,and Jung, R.Fv, 1983. Processes controlling metal ion attenuation
in acid mine drainage streams, Geochimica et Cosmochimica Acta, v. 47, p. 1957-1973.
Presents detailed analyses of two acid mine drainage streams in Australia to determine
the dominant processes that control heavy metal transport and attenuation under conditions of
chronic high-level pollution. Streams receive AMD input from sulfide-rfch base and precious
metals deposits. Results show that natural processes cause precipitation of metal hydroxides
that lower Fe, Cu, and Al in stream waters as pH rises due to the inflow of higher pH tributary
waters. Concentrations of Cd, Zn, and Mn apparently diminished only by dilution. Presents a
graphical method to delineate the point along a stream channel where chemical removal
mechanisms become effective for each element.
Cliff, John, Sterner, Pat, Skousen, Jeff, and Sexstone, Alan, 1995. Treatment of acid mine
drainage with a combined wetland/anoxic limestone drain: A comparison of laboratory versus
field results, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine Drainage: Control &
Treatment, 2nd edition, National Mine Land Reclamation Center, p. 311-330.
Compares results from the Douglas Highwall project (WV) and greenhouse experiments
conducted at West Virginia University, both of which utilized similar designs. Found that slight
differences in influent flow rate and the hydraulic conductivity of organic substrates used in
anoxic limestone drains greatly affected the ability of the system to reduce and remove Fe,
increase Eh, and neutralize acid.
Cohen, R.H., 1996. The technology and operation of passive mine drainage treatment
systems, in Managing Environmental Problems at Inactive and Abandoned Metals Mine Sites,
U.S. Environmental Protection Agency Seminar Publication No. EPA/625/R-95/007, p. 18-29.
Reference not available.
Colorado Department of Public Health and Environment, Wetlands-based treatment,
http://www.gnet.org/gnet/tech/techdb/site/demongng/cotodepa.htm.
Describes the technology in use and status of studies at metal mines in Colorado.
Concurrent Technologies Corporation, "Recovering Metal Values from Acid Mine Drainage:
Market and Technology Analyses," Summary Report to Southern Alleghenies Conservancy,
March 29, 1996.
Reference not available.
Dames and Moore, 1981, "Outcrop Barrier Design Guidelines For Appalachian Coal Mines,"
prepared for the U.S. Bureau of Mines, Contract J0395069, Bureau of Mines Open File Report
134-81. .
Reference not available.
Dames and Moore, 1981, "Outcrop Barrier Design Guidelines For Appalachian Coal Mines,"
prepared for the U.S. Bureau of Mines, Contract J0395069, Bureau of Mines Open File Report
134-81.
Reference not available.
Davison, J., 1993. Successful acid mine drainage and heavy metal site bioremediation, in
Moshiri, Gerald A., ed., Constructed Wetlands for Water Quality Improvement, Lewis
Publishers, Boca Raton, p. 167-178.
Discusses the Lambda Bio-Carb Process (patent pending) for in situ bioremediation.
The process uses site-indigenous cultures in microecological balance to construct a self-
sustaining system that self-adjusts to variations in influent composition.
-------
B-10 Appendix B; Acid Mine Drainage
Desborough, George A., 1992. Ion exchange capture of copper, lead, and zinc in acid-rock
drainages of Colorado using natural clinoptSolite—Preliminary field studies, U.S. Geological
Survey Open-File Report 92-614, 16 pp.
Study evaluated efficiency of clinoptilolite-rich rock in reducing heavy metal
concentrations in 9 stream sites contaminated by acid mine drainage (pH=2-5) in central CO.
Fe and As deposited as fine particles on zeolite surface, whereas Cu, Pb, and Zn were ion
exchangeable using ammonium chloride solution. Dominant factors influencing ion exchange
rates were dissolved metal concentration, water flow rate, zeolite fragment size, and water
temperature.
Dietz, Jonathan M., Watts, Robert G, and Stidinger, Dennis M., 1994., Evaluation of acidic mine
drainage treatment in constructed wetlands systems, in International Land Reclamation and
Mine Drainage Conference and Third International Conference on the Abatement of Acidic
Drainage, U.S. Bureau of Mines Special Publication, SP 06A-94, vol. 1, p. 71-79.
Conducted and evaluated field tests of 6 constructed wetland treatment systems for a 2
year period. Tests monitored acid and metals removal from stream sites receiving AMD in
central PA.
Donlan, Ron, "Constructed Wetlands for the Treatment of Acid Mine Drainage," Water
Pollution Control Association of Pennsylvania, March-April 1989.
Reference not available.
Donovan, Joseph J. and Ziemkiewicz, Paul F., 1994. Early weathering of pyritic coal spoil piles
interstratified with chemical amendments, in International Land Reclamation and Mine Drainage
Conference and Third International Conference on the Abatement of Acidic Drainage, U.S.
Bureau of Mines Special Publication, SP 06A-94, vol. 1, p. 119-128.
Monitored acidity from eleven 400-ton constructed piles in WV during 1982. Piles had
1) no treatment, 2) layered base amendments (limestone, lime, rock phosphate), and 3) sodium
lauryl phosphate amendment. Acid conditions ensued for all nontreated piles and amended
piles with NP/MPA<1. Acid conditions developed in some amended piles with NP/MPA up to
2.3. Layered amendments were judged to be less effective than piles in which basic materials
were evenly dispersed.
Doyle 1990. Mining and Mineral Processing Wastes, proceedings of the Western Regional
Symposium on Mining and Mineral Processing Wastes, Berkeley, California, May30-June 1,
1990, Society for Mining, Metallurgy, and Exploration, Inc., Doyle, F.M., editor, 1990.
Reference not available.
DuMond, Mike, 1988. New Mexico mine drainage treatment in Proceedings of the U.S. EPA's
Forum on Remediation ofCERCLA Mining Waste Sites, April 25, 1989, Ward, Colorado, p. 65-
94.
Describes a variety of techniques presently being used to treat AMD at coal, metal, and
uranium mines in New Mexico. Both active and passive treatment techniques are discussed.
Durkin, T.V. and Hermann, J.G., 1996. Focusing on the problem of mining wastes: An
introduction to acid mine drainage, in Managing Environmental Problems at Inactive and
Abandoned Metals Mine Sites, U.S. Environmental Protection Agency Seminar Publication No.
EPA/625/R-95/007, p. 1-3.
Reference not available.
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Appendix B: Acid Mine Drainage B-11
Eger, Paul and Lapakko, Kim, 1989. Use of wetlands t<3 remove nickel and copper from mine
drainage, in Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment, Lewis
Publishers, Chelsea, Ml, p. 780-787.
Describes the use of natural wetlands to treat drainage from taconite mines in MN
contaminated with Ni, Cu, Co, and Zn. Also discusses the siting and design of test cells within
existing wetlands.
Eger, P. and Lapakko, K., 1988. Nickel and copper removal from mine drainage by a natural
wetland, Mine Drainage and Surface Mine Reclamation, Volume I: Mine Water and Mine
Waste, U.S. Bureau of Mines Information Circular 9183, p. 301-309.
Reports results of a study of rnetal removal from neutral drainage (pH=7.2) generated
from an open-pit taconite mine in MN. The natural white cedar peatland removed significant
amounts of nickel and copper, most taken up by the peat.
Ellison, R.D. & Hutchison, I.P.G., Mine Waste Management: A Resource for Mining Industry
Professionals, Regulators and Consulting Engineers, Lewis Publishing, INC.,Chelsea, Ml, 1992,
pgs. 127-184.
Reference not available.
Emerick, J.C.,. Huskie, W.W., and Cooper, D.J., 1988. Treatment of discharge from a high
elevation metal mine in the Colorado Rockies using an existing wetland, in Mine Drainage and
Surface Mine Reclamation, Volume I: Mine Water and Mine Waste, U.S. Bureau of Mines
Information Circular 9183, p. 345-351.
Reports inconclusive results of a study in which acidic mine drainage (pH=3.6) was
diverted into a natural wetland. Study found that significant accumulations of metals existed in
the wetland prior to the introduction of mine drainage and that the low hydraulic conductivity of
the peat precluded significant flow of mine drainage through wetland sediments. Study did
confirm that the plant species present had a high tolerance to metals and low pH and could be
used in constructed wetlands throughout the region.
Emerick, JohnC., Wildeman, Thomas R., Cohen, Ronald R.,and Klusman, Ronald W., 1994.
Constructed wetland treatment of acid mine discharge at Idaho Springs, Colorado, in K.C.
Stewart and R.C. Severson, eds., Guidebook on the Geology, History, and Surface-Water
.Contamination and Remediation in the Area from Denver to Idaho Springs, Colorado, U.S.
Geological Survey Circular 1097, p. 49-55.
Investigates factors influencing the effectiveness of wetlands constructed to.treat acid
mine drainage from the Big Five Tunnel over a three year period. Discusses biochemical
processes that lead to effective treatment. Results show that Cu and Zn are effectively
removed, Fe less effectively removed, and pH buffered to 5.5 or higher for the long term.
Concludes that treatment systems incorporating forced vertical flow are more effective than
those relying on lateral flow and that low flow rates permit more metal removal than high flow
rates.
Environmental Research and Applications, Inc. "Concentrated Mine Drainage Disposal Into
Sewage Treatment Systems; the Disposal of Acid Brines from Acid Mine Drainage in Municipal
Wastewater Treatment." Washington: EPA Research and Monitoring, 1971.
Reference not available.
-------
B-12 Appendix B: Acid Mine Drainage
Erickson, B.M., Briggs, P.M., and Peacock, T.R., 1996. Metal concentrations in sedges in a
wetland receiving add mine drainage from St. Kevin Gulch, Leadville, Colorado, in
Morganwalp, David W. and Aronson, David A., eds., U.S. Geological Survey Toxic Substances
Hydrology Program—Proceedings of the Technical Meeting, Colorado Springs, CO, September
20-24, 1993, U.S. Geological Survey Water Resources Investigation Report 94-4015, p. 797-
804.
Characterizes the concentrations of Cd, Cu, Fe, Pb, Mn, and Zn in apparently healthy
sedges from a natural wetland receiving AMD. Finds that baseline concentrations are elevated
above the geometric mean for noncbntaminated areas and that Cd, Pb, and Zn locally exceed
recommended dietary levels for cattle.
Erickson, B.M., Briggs, P.M., and Peacock, T.R., 1994. Metal composition of sedges collected
on the wetland receiving acid mine drainage from St. Kevin Gulch, Leadville, Colorado,
U.S.G.S. Research on Mineral Resources - 1994, U.S. Geological Survey Circular 1103-A, p.
33-34.
Characterizes the content of Cd, Cu, Fe,-Pb, Mn, and Zn in sedges from a wetland
receiving acid mine drainage, in order to determine background values and the amount of
material removed from AMD influent.
Erickson, L.J., and J.H. Deniseger, 1987. "Impact Assessment of Acid Drainage from an
Abandoned Copper Mine on Mt. Washington", in an unpublished report of the British Columbia
Ministry of Environment and Parks, Waste Management Program, Nanaimo.
Reference not available.
Evangelou, V., U. Sainju and E. Portig, 1991, "Some Considerations When Applying ,
Limestone/Rock Phosphate Materials on to Acid Pyritic Spoils," in Proceedings Twelfth Annual
West Virginia Surface Mine Drainage Task Force Symposium , April 3-4, 1991, Morgantown,
West Virginia.
Reference not available.
Faulkner, Ben B. and Skousen, Jeff G., 1995. Treatment of acid mine drainage by passive
treatment systems, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine Drainage:
Control & Treatment, 2"" edition, National Mine Land Reclamation Center, p. 267-274.
Reviews the effectiveness of wetlands and anoxic limestone drains in treating AMD from
coal mines in WV. Studied sites include the Keister, S. Kelly, Pierce, and Z&F wetlands and the
Greendale, Kodiak, Lillybrook, Preston, Lobo Capital, and Benham anoxic limestone drains.
Finds that limestone in wetland substrates does not appear to improve metal removal efficiency,
that hay added to anoxic limestone drains diminishes the ability of limestone to neutralize
acidity, and that maintaining water flow through the drain is critical to the drain's success.
Faulkner, Ben B. and Skousen, Jeff G., 1993. Monitoring of passive treatment systems: An
update, in Proceedings Fourteenth Annual West Virginia Surface Mine Drainage Task Force
Symposium, Morgantown, West Virginia, April 27-28, 1993.
Reports updated monitoring results on the Keister, S. Kelly, Pierce, and Z&F wetlands
and the Benham, Lobo Capital, Kodiak, Lillybrook, and Preston anoxic limestone drains, all of
which are associated with eastern coal mines.
Faulkner, B. (ed.), 1991, "Handbook for Use of Ammonia in Treating Mine Waters," West
Virginia Mining and Reclamation Association, Charleston, West Virginia.
Reference not available.
-------
Appendix B: Acid Mine Drainage B-13
'•>;"-• - .-"'ST '.-,
Filipek, Lorraine H., 1986. Organic-metal interaction irfa stream contaminated by acid mine
drainage, in Donald Carlisle, Wade L. Berry, Isaac R. Kaplan, and John R.Watterson (eds).,
Mineral Exploration: Biological Systems and Organic Matter, Rubey Volume V, Prentice-Hall,
Englewood Cliffs, NJ, p. 206.
Abstract reporting results of a study to examine the effect of pH on the metal
scavenging ability of algae. Concludes that cationic species are less effectively scavanged at
low pH, whereas anionic metal species (e.g., As) are completely removed from solution within a
short distance from the source.
Frostman, T.M., 1993. A peat/wetland treatment approach to acidic mine drainage abatement,
in Moshiri, Gerald A., ed., Constructed Wetlands for Water Quality Improvement, Lewis
Publishers, Boca Raton, p. 197-200.
Reviews the design and operation of a peat/wetland system that could be installed to
treat AMD from an iron mine in MN (pH of 5-6, low metal content).
Fyson, Andrew, Kalin, Margarete, and Adrian, Les, W., 1994. Arsenic and nickel removal by
wetland sediments, in International Land Reclamation and Mine Drainage Conference and Third
International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines Special
Publication, SP 06A-94, vol. 1, p. 109-118.
Laboratory experiments to test the capacity of muskeg sediments to treat mildly acidic
(pH=4), metal-bearing drainage. Alfalfa, potato waste and hydroseed mulch used to simulate
muskeg sediments. Experiments show this treatment can be effective in removing metals and
raising pH, especially if reducing conditions can be maintained.
Ganse, Margaret A., 1993. Geotechnical Design of a Four-stage Constructed Wetland for the
Remediation of Acid Mine Drainage, Unpubl. M.S. Thesis, Colorado School of Mines, Golden,
CO, 133pp.
Develops guidelines for creating effective conceptual designs that utilize knowledge of
wetland chemistry, hydraulic capacity, and structural integrity of treatment components. Applies
guidelines to the redesign of the passive treatment system from the Marshall No. 5 coal mine
near Boulder, CO. System components include an anoxic limestone drain to add alkalinity, a
settling basin to promote aeration of the AMD, a wetland with aerobic and anaerobic function to
raise pH, and a polishing ceil for final aerobic treatment. Preliminary results show pH
increasing from 4.5 to 6.4 and alkalinity increasing from 8 mg/l to 79 mg/l.
Garbutt, K., Kittle, D.L., and McGraw, J.B., 1994. The tolerance of wetland plant species to
acid mine drainage: A method of selecting plant species for use in constructed wetlands
receiving mine drainage, in International Land Reclamation and Mine Drainage Conference
and Third International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines
Special Publication, SP 06A-94, vol. 2, p. 413.
Study exposed five common wetland species to AMD with a range of pH values to test
individual species tolerance. Recommended species are suggested for various pH levels.
Girts, M.A. and Kleinmann, R.L.P., 1986. Constructed wetlands for treatment of mine water, in
American Institute of Mining Engineers Fall Meeting, St. Louis, MO.
Reference not available.
Gormely, L., Higgs, T.W., Kistritz, R.U., and Sobotewski, A., 1990. Assessment of wetlands for
gold mill effluent treatment, report prepared for the Mine Pollution Control Branch of
Saskatchewan Environment and Public Safety, Saskatoon, SK, Canada, 63 pp.
Reference not available.
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B-14 Appendix B: Acid Mine Drainage
Gross, M.A., Formica, S.J., Gandy, L.C., and Hestir, J., 1993. A comparison of local waste
materials forsulfate-reducing wetlands substrate, in Moshiri, Gerald A., ed., Constructed
Wetlands for Water Quality Improvement, Lewis Publishers, Boca Raton, p. 179-185.
Investigates the suitability of locally derived organic materials for their use in sulfate-r
reducing constructed wetlands at a clay mine in AR and presents the results of lab tests.
Groupe de Recherche en Geologic de L'ingenieur, 1992. Acid Mine Drainage Generation from
a Waste Rock Dump and Evaluation of Dry Covers using Natural Materials: La Mine Doyon
Case Study, Quebec, Final Report to Service de la Technologie Miniere Centre de Recherches
Minerales, 22 pp.
Objectives were to characterize the problem of AMD generation in the south mine dump
of the La Mine Doyon and to study the feasibility of using natural materials to construct dry
covers to control air and water circulation in the dump.
Guertin, deForest, Emerick, J.C., and Howard, E.A., 1985. Passive mine drainage treatment
systems: a theoretical assessment and experimental evaluation, Colorado Mined Land
Reclamation Divisbn, Unpubl. Manuscript, 71 pp.
Describes utility of passive AMD systems with application to the Marshall No. 5 coal
mine.
Hammer, D.A., ed., 1989. Constructed Wetlands for Wastewater Treatment, Lewis Publishers,
Ann Arbor, Mi.
Contains numerous papers on passive treatment systems at metal mines and coal
mines, most of which are annotated herein.
Healey, P.M. and Robertson, A.M., 1989. A case history of an acid generation abatement
program for an abandoned copper mine, in Vancouver Geotechnical Society, Geotechnical
Aspects of Tailings Disposal and Acid Mine Drainage, May 26,1989.
Describes rationale for the implementation of an AMD abatement program at an open-
pit copper mine and aspects of the design. The method selected to control AMD consisted of a
low permeability till cover over waste material to reduce oxygen and water infiltratbn to sulfide-
bearing materials, collection and diversion ditches and a limestone-lined channel.
Hedin, Roberts., Hammack, Richard, and Hyman, David, 1989. Potential importance of sulfate
reduction processes in wetlands constructed to treat mine drainage, in Hammer, Donald A., ed.,
Constructed Wetlands for Wastewater Treatment, Lewis Publishers, Chelsea, Ml, p. 508-514.
Discusses the processes by which sulfides are formed and destroyed in wetlands and
the importance of maintaining a sulfide-forming (reducing) environment. Presents
characteristics of an ideal treatment system and discusses it operation.
Hedin, R.S. and Nairn, R.W., 1993. Contaminant removal capabilities of wetlands constructed
to treat coal mine drainage, in Moshiri, Gerald A., ed., Constructed Wetlands for Water Quality
Improvement, Lewis Publishers, Boca Raton, p. 187-195.
Reports measurements of contaminant removal at 11 constructed wetlands in western
PA. Concludes that contaminant removal occurs in a manner consistent with well-known
chemical and biological processes.
Hedin, R.S. and Nairn, R.W., 1990. Sizing and performance of constructed wetlands: Case
studies, in Proceedings of the 1990 Mining and Reclamation Conference and Exhibition,
Charleston, WV, vol. 2, p. 385-392.
Reference not available.
-------
Appendix B: Acid Mine Drainage B-15
Hedin, Robert S., Nairn, Robert W., and Klelnmann, Robert L.P., 1994. Passive Treatment of
Coal Mine Drainage, U. S. Bureau of Mines, Information Circular 9389, 35 pp.
Reviews the construction and operation of passive treatment systems, including
chemical and biological processes, contaminant removal, and system design and sizing.
Considers three types of passive technologies: aerobic wetlands, organic substrate wetlands,
and anoxic limestone drains. Presents a model for design and sizing of passive treatment
systems.
Hedin, Robert S. and Watzlaf, George R., 1994. The effects of anoxic limestone drains on
mine water chemistry, in International Land Reclamation and Mine Drainage Conference and
Third International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines
Special Publication, SP 06A-94, vol. 1, p. 185-194.
Studied construction and water quality characteristics of 21 anoxic limestone drains in
Appalachia to identify and evaluate factors responsible for the variable performance of these
systems. Large changes in acidity were primarily associated with retention of ferric iron and
aluminum. Presents a technique to determine drain size.
Hedin, Roberts, and Robert W. Nairn. "Designing and Sizing Passive Mine Drainage
Treatment Systems," 13th Annual West Virginia Surface Mine Drainage Task Force
Symposium, April 8-9, 1992.
Reference not available.
Hedin, R.S., et al., "Constructing Wetlands to Treat Acid Mine Drainage," Course Notes, 13th
Annual West Virginia Surface Mine Drainage Task Force Symposium, April 8-9, 1992.
Reference not available.
Hedin, R.S., "Passive Anoxic Limestone Drains: A Preliminary Summary," 1990.
Reference not available.
Hedin, R.S. and R.W. Nairn, 'Sizing and Performance of Constructed Wetland: Case Studies,"
Mine and Reclamation Conference and Exhibition^ Charleston, WV, April 23-26, 1990.
Reference not available.
Hedin, R.S., "Treatment of Coal Mine Drainage with Constructed Wetlands," Wetlands,
Ecology and Conservation: Emphasis in Pennsylvania, Pennsylvania Academy of Science,
1989. (Chapter 28)
Reference not available.
Heil, Michael T. and Kerins, Jr., Francis J., 1988= The Tracy wetlands: A case study of two
passive mine drainage treatment systems in Montana, in U.S. Bureau of Mines, Mine Drainage
and Surface Mine Reclamation, Volume I: Mine Water and Mine Waste, U.S. Bureau of Mines
Information Circular 9183, p. 352-358.
Reports results for two constructed wetlands receiving acidic (pH=2.7) coal mine
drainage. Low system retention times and minimal contact time between the peat and mine
drainage precluded effective treatment by these wetlands.
-------
B-16 Appendix B: Acid Mine Drainage
Hellier, William W., Giovannitti, Ernest F., and Slack, Peter f., 1994. Best professbnal
judgment analysis for constructed wetlands as a best available technology for the treatment of
post-mining groundwater seeps, in International Land Reclamation and Mine Drainage
Conference and Third International Conference on the Abatement of Acidic Drainage, U.S.
Bureau of Mines Special Publication, SP Q6A-94, vol. 1, p. 60-69.
Results of an analysis of 73 constructed wetlands to assess removal of acidity, Fe and
Mn from surface coal mines. Develops sizing guidelines and costs to treat seeps for 25 years
with and without anoxic limestone drain pretreatment.
Henrot, Jacqueline, Wieder, R. Kelman, Heston, Katherine P., and Nardi, Marianne P., 1989.
Wetland treatment of coal mine drainage: Controlled studies of iron retention in model wetland
systems, in Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment, Lewis
Publisher, Chelsea, Mi, p. 793-800.
Results of a pilot lab study to evaluate the effects of Fe concentration in influent waters
on Fe retention in wetlands. Concludes that the formation of iron oxides is key control on iron
retention and the effective lifetime of a constructed wetland.
Holm, J. David and Bishop, Michael B., 1985. Passive mine drainage treatment in Randol
International, Ltd., Water Management and Treatment for Mining and Metallurgical Operations,
vol. 3, p. 1593-1602.
Describes natural processes that can be used to passively treat acidic mine drainage.
Includes a description of wetlands constructed to treat AMD from the Delaware Mine, a silver
mine in the Peru Creek, CO dranage and the Schuster Mine and Marshall No. 5 Mine, both of
which are coal mines.
Holm, J.D. and Elmore, T., 1986. Passive mine drainage treatment using artificial and natural
wetlands, in Proceedings of the High Altitude Revegetatbn Workshop, no. 7, p. 4148.
Reference not available.
Holm, Bishop, and Tempo, 1985. Incomplete reference included in Randol International, Ltd.,
Water Management and Treatment for Mining and Metallurgical Operations, vol. 3, p. 1651-
1670.
Briefly describes passive treatment systems in use at the Marshall No. 5 Coal Mine
(CO), U.S. Bureau of Mines Bruceton Research Station, AMAX Buick lead and zinc mill (MO),
New Lead Belt region (MO), and the Pierrepont (NY) lead-zinc mine.
Holm, J.D., 1983. Passive mine dranage treatment: Selected case studies, in Medine A. and
Anderson, M., eds., Proceedings, 1983 National Conference on Environmental Engineering,
American Society of Civil Engineers.
Provides descriptions of case studies of wetlands constructed to treat AMD from non-
coal mines in Colorado. Reference not available.
Holm, J. David, and Guertin, deForest, 1985. Theoretical assessment and design
considerations for passive mine drainage treatment systems, in Randol International, Ltd.,
Water Management and Treatment for Mining and Metallurgical Operations, vol. 3, p. 1603-
1650.
Briefly describes passive treatment mechanisms including pH modulation, catbn
exchange, sorption and coprecipitation, complexing, bblogical extraction, and dilutbn.
Discusses the design of passive treatment systems and evaluation of appropriate sites for their
installation.
-------
Appendix B: Acid Mine Drainage B-17
Howard, Edward A., Emerick, John C., and Wildeman, f homas R., 1989. Design and
construction of a research site for passive mine drainage treatment in Idaho Springs, Colorado,
in Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment, Lewis
Publishers, Chelsea, Ml, p. 761-764.
Describes the design and construction of a wetland in a high mountain climate to treat
AMD from the Big Five Tunnel. Provides information on liner types, drain spacing and size,
organic substrate materials, and vegetation.
Howard, Edward A., Emerick, John C., and Wildeman, Thomas R., 1988. The design,
construction and initial operation of a research site for passive mine drainage treatment in
Idaho Springs, CO, in Proceedings of the U.S. EPA's Forum on Remediation ofCERCLA
Mining Waste Sites, April 25, 1989, Ward, Colorado, p. 122-133.
Describes the design and construction of an artificial wetland to treat AMD from the Big
Five Tunnel precious metal mine. Included are sections that discuss the preparation of plants
and substrate materials and procedures for sample collection.
Howard, Edward A., Hestmark, Martin C., and Margulies, Todd D., 1989. Determining
feasibility of using forest products or on-site materials in the treatment of acid mine drainage in
Colorado, in Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment, Lewis
Publishers, Chelsea, Ml, p. 774-779.
Characterizes the cation exchange capacities and metal removal efficiencies of humus
and forest litter from ponderosa pine, iodgepoie pine, spruce-fir, and aspen forests. Concludes
that ponderosa and aspen litters have the highest bn exchange capacities but that aspen and
spruce-fir materials were the most efficient at removing metals from AMD. These materials are
suitable for passive treatment systems.
Huskie, William W., 1987. Pennsylvania mine drainage diversion study: Site survey and water
quality assessment, in Emerick, John C., Cooper, David J., Huskie, William W., and Lewis, W.
Stephen, eds., Documentation and Analysis of the Effects of Diverted Mine Water on a Wetland
Ecosystem, and Construction of a Computerized Data Base on Acid Mine Drainage in
Colorado, Final Report to the Mined Land Reclamation Division, Department of Natural
Resources, Colorado, p. 13-50.
Evaluated the effects of rerouting AMD from a base and precious metals mine into a
wetland ecosystem. Results showed that only Fe was significantly removed, with little effect on
Al, Mn, orZn levels. Surface water quality below the wetland was not improved significantly.
The natural wetland was found to have a significant metal content prior to diversion that may
have precluded additbnal metal uptake during the experiment.
Huskie, William W., 1987. The Pennsylvania Mine Diversion Drainage Study: Evaluation of an
Existing High Mountain Wetland for Passive Treatment of Metal-Laden Acid Mine Drainage in
Colorado, Unpubl. M.S. Thesis, Colorado School of Mines, Golden, CO.
Reference not available.
Hutchison, Ian P.G., Leonard, Sr., Michael L., and Cameron, David P., 1995. Remedial
alternatives identification and evaluation, in Posey, Harry H., Pendleton, James A., and Van Zyl,
Dirk, eds., Proceedings: Summitville Forum 95, Colorado Geological Sodety Special
Publicatbn 38, p. 109-120. This paper describes how treatment strategies (active and
passive) are being developed for the Summitville (CO) Mine. It provides a brief summary of the
AMD issues at Summitville Mine, identifies the types of remedial technologies and process
operations that could be applied at the site, discusses the basis for evaluating alternative
remedial measures, and describes selected remedial measures and their implementation.
-------
B-18 Appendix B: Acid Mine Drainage
Hyman, D.M. and G.R. Watzlaf, "Mine Drainage Characterizatbn for the Successful Design and
Evaluation of Passive Treatment Systems," presented at the 17th Annual National Association
of Abandoned Mine Lands Conference. Undated.
Reference not available.
Inventory Guiding Principles Group, 1996. Guiding Principles for Inventorying Inactive and
Abandoned Hardrock Mining Sites, The Inventory Guiding Principles Group, Western
Governor's Association and U.S. Bureau of Mines.
Reference not available.
Jones, D.R. and Chapman, B.M., 1995. Wetlands to treat AMD - Facts and fallacies, in
Grundon, N.J.and Bell, L.C., eds., Proceedings of the Second Annual Mine Drainage
Workshop, Queensland, Australia, p. 127-145.
Reference not available.
Kelly, Martyn, 1988, Mining and the Freshwater Environment, Elsevier Science Publishing Co.,
London, pgs. 16-42
Reference not available.
Kepler, D.A., 1988. Overview of the role of algae in the treatment of acid mine drainage, in
U.S. Bureau of Mines, Mine Drainage and Surface Mine Reclamation, Volume I: Mine Water
and Mine Waste, U.S. Bureau of Mines Information Circular 9183, p. 286-290.
Reports preliminary results from a wetland system constructed to treat coal mine
drainage in PA (pH=5.0), which show that algae effectively bioaccumulate metals including Mn
and Fe.
Kepler, Douglas A. and McCleary, Eric C., 1994. Successive alkalinity-producing systems
(SAPS) for the treatment of arid mine dranage, in International Land Reclamation and Mine
Drainage Conference and Third International Conference on the Abatement of Acidic Drainage,
U.S. Bureau of Mines Special Publication, SP 06A-94, vol. 1, p. 195-204.
Study focuses on the ability to create effective anoxic limestone dissolutbn treatment
components for AMD abatement in open atmospheres. Studies 3 SAPS in PA that utilize
wetlands with mixed substrates of organic compost and limestone gravel. This wetland
configuration promotes anoxic conditions, generates alkalinity in excess of acidity regardless of
acidity concentrations, produces quasi-neutral water and decreases treatment area
requirements.
Kim, A., B. Heisey, R. L P. Kleinmann and M. Duel, 1982, "Acid Mine Drainage: Control and
Abatement Research," U.S. Bureau of Mines Informatbn Circular 8905.
Reference not available.
Kimball, Briant A., 1996. Past and present research on metal transport in St. Kevin Gulch,
Colorado, in Morganwalp, David W. and Aronson, David A., eds., U.S. Geological Survey Toxic
Substances Hydrology Program—Proceedings of the Technical Meeting, Colorado Springs, CO,
September 20-24, 1993, U.S. Geological Survey Water Resources Investigation Report 94-
4015, p. 753-758.
Describes the chemical reactions that affect metal transport in AMD in surface waters of
the St. Kevin Gulch drainage near Leadville, CO in the context of hydrologic setting. Results
can be used to design effective remediation measures.
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Appendix B: Acid Mine Drainage B-19
Kleinmann, Robert L.P., 1985. Treatment of acid mine Waters by wetlands, in U.S. Bureau of
Mines, Control of Acid Mine Drainage: Proceedings of a Technobgy Transfer Seminar, U.S.
Bureau of Mines Information Circular 9027, p. 48-52.
Discusses general aspects of passive AMD treatment and provides an update on pilot-
scale and full-scale field evaluations being conducted by the Bureau of Mines.
Kleinmann, R.L.P. and Hedin, R.S., 1993. Treat minewater using passive methods, Pollution
Engineering, vol. 25, no. 13, p. 20-22.
Reference not available.
Kleinmann R.LP., DA Crerarand R.R. Pacelli, 1981, "Biogeochemistry of Acid Mine Drainage
and a Method to Control Acid Formation," Mining Engineering, March 1981. -
Reference not available.
Kleinmann, R.L.P. and R. Hedin, "Biological Treatment of Mine Water: an Update", in Chalkley,
M.E., B.R. Conrad, V.I. Lakshmanan, and K.G. Wheeland, 1989, Tailings and Effluent
Management, Pergamon Press, New York, pgs 173-179.
Reference not available.
Klepper, R.P., R.C Emmett, and J.S. Slottee, "Equipment Selectbn For Tailings and Effluent
Management", in Chalkley, M.E., B.R. Conrad, V.I. Lakshmanan, and K.G. Wheeland, 1989,
Tailings and Effluent Management, Pergamon Press, New York, pgs. 207-214.
Reference not available.
Klusman, R.W. and Machemer, S.D., 1991. Natural processes of acidity reduction and metal
removal from acid mine drainage, in Peters, D.C., ed., Geology in the Coal Resource Utilization,
Tech Books, Fairfax, VA, p. 513-540.
Reference not available.
Knight Piesold, Ltd., 1996. Wheal Jane minewater project: The development of a treatment
strategy for the acid mine drainage, in Minerals, Metals, and Mining, Institution of Mining and
Metallurgy.
Reference not available.
Kolbash, Ronald L. and Romanoski, Thomas L, 1989. Windsor Coal Company wetland: An
overview, in Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment, Lewis
Publishers, Chelsea, Ml, p. 788-792.
Describes the design, construction, and effectiveness of a wetland treatment system at
a coal mine in WV.
Kuyucak, N.and St-Germain, P., 1994. Possible options for/'n situ treatment of acid mine
seepages, in International Land Reclamation and Mine Drainage Conference and Third
International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines Special
Publication, SP 06B-94, vol. 2, p. 311 -318.
Presents results of bench-scale evaluation tests of passive treatment of base metal acid
mine drainage seepages. Assessed methods including: 1) anoxic lime drains (limestone kept
under anoxic conditions); 2) limestone-organic mixture utilizing sulfate-reducing bacteria; 3)
biosorbency in which metals are taken up by wood waste, and 4) a biotrench that utilizes
different nutrients than the limestone-organic mixture. Concludes that a combination of 1 and 2
above is best for treating AMD.
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B-20 Appendix B: Acid Mine Drainage
Kwong, Y.T.J., 1992. Generation, attenuation, and abatement of acidic drainages in an
abandoned minesite on Vancouver, Island, Canada, in Singhal, Raj K., Mehrotra, Anil K., Fytas,
Kostas, and Collins, Jean-Luc, eds., Environmental Issues and Management of Waste in
Energy and Mineral Production, A.A. Balkema, Rotterdam, p. 757-762.
Discusses the potential utility of passive wetlands treatment of AMD from the
abandoned Mount Washington porphyry copper mine. Describes successes and failures of
reclamation activities conducted to date.
Ladwig, K., P. Erickson and R. Kleinrnann, 1985, Alkaline Injection: An Overview of Recent
Work," in Control of Acid Mine Drainage, Proceedings of a Technology Transfer Seminar, U.S.
Bureau of Mines Information Circular 9027.
Reference not available.
Ladwig, K., P. Erickson and R. Kleinrnann, 1985, Alkaline Injection: An Overview of Recent
Work," in Control of Acid Mine Drainage, Proceedings of a Technology Transfer Seminar, U.S.
Bureau of Mines Information Circular 9027.
Reference not available.
LaRosa, et al., Black, Sivalls, and Bryson, Inc. "Evaluation of a New Acid Mine Drainage
Treatment Process," prepared for the U.S. Environmental Protection Agency; for sale by the
Superintendent of Documents, U.S. Government Printing Office, 1971.
Reference not available.
Logsdon, Mark and Mudder, Terry, 1995. Geochemistry of spent ore and water treatment
issues in Posey, Harry H., Pendleton, James A., and VanZyl, Dirk, eds., Proceedings:
Summitville Forum '95, Colorado Geological Society Special Publication 38, p. 99-108.
Describes the design and operation of the cyanide heap leach pad at the Summitville
precious metals mine, a program for decommissioning the leach pad, and a geochemical
evaluation of potential environmental impacts from the pad. Includes brief sections on active
and passive treatment of acid drainage from the leach pad. Passive treatment alternatives
under consideration include wetlands, engineered anoxic systems, and direct land application;
does not include information on design and feasibility of passive systems.
Madel, Robin E., 1992. Treatment of Acid Mine Drainage in Sulfate Reducing Bioreactors:
Effect of Hydraulic Residence Time and Metals Loading Rates, Unpubl. M.S. Thesis, Colorado
School of Mines, Golden, CO.
Study investigated the ability of sulfate-reducing bacteria to treat AMD at bwer
residence times by using multiple stage systems in parallel and series. The test results
determined using samples of AMD from the Eagle Mine have implications for the design of
passive treatment systems.
Meek A., 1991, "Assessment of Acid Preventative Techniques at the Island Creek Mining Co.
Tenmile Site," in Proceedings Twelfth Annual West Virginia Surface Mine Drainage Task Force
Symposium, April 3-4, 1991, Morgantown, West Virginia.
Reference not available.
MEND, "Economic Evaluation of Acid Mine Drainage Technologies," MEND Report 5.8.1,
January 1995.
Reference not available.
MEND, "Acid Mine Drainage - Status of Chemical Treatment and Sludge Management
Practices," MEND Report 3.32.1, June 1994,
Reference not available.
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Appendix B: Acid Mine Drainage B-21
MEND, 1993. Treatment of Acidic Seepages Using Wetland Ecology and Microbiology: Overall
Program Assessment, MEND Report 3.11.1, Natural Resources Canada.
Reference not available.
MEND, "Study on Metals Recovery/Recycling from Acid Mine Drainage," MEND Project
3.21.1(a), July 1991.
Reference not available.
MEND, 1991. Study of Metals Recovery/Recycling from Acid Mine Drainage, MEND Report
3.21.1(a), Natural Resources Canada.
Reference not available.
MEND, 1990. Assessment of Existing Natural Wetlands Affected by Low pH, Metal
Contaminated Seepages (Acid Mine Drainage), MEND Report 3.12.1a, Natural Resources
Canada.
Reference not available.
MEND, MEND Reports Available, Mine Environment Neutral Drainage Program
http://www.NRCan.gc.ca/mets/mend/report-t.htm
Listing of reports available for purchase.
Mills, Chris, An Introduction to Acid Rock Drainage.
http://www.enviromine.com/ard/Eduardpage/ARD.htm
Brief description of the chemistry of acid mine drainage generation and neutralization
and the kinetics of the chemical reactions. Includes links to pages concerning the role of micro-
organisms in AMD.
Morin, Kevin A., 1990. Acid Drainage from Mine Walls: The Main Zone Pit at Equity Silver
Mines, British Columbia Acid Mine Drainage Task Force, 109 pp.
Provides an overview of the generation and migration of acid mine drainage at open-pit
mines, with emphasis on the Equity silver mine in British Columbia. Presents a predictive
model'for acid drainage from pit walls that could be used to design treatment systems.
Mueller, R.F., Sinkbeil, D.E., Pantano, J., Drury, W., Diebold, F., Chatham, W., Jonas, J.,
Pawluk.'o., and Figueira, J., 1996. Treatment of metal contaminated groundwater in passive
systems: A demonstration study, in Proceedings of the 1996 National Meeting of the American
Society for Surface Mining and Reclamation, Knoxville, TN, May 19-25,1996, p. 590-598.
Reference not available.
Noller, B.N., Woods, P.H., and Ross, B.J., 1994. Case studies of wetland filtration of mine
waste'water in constructed and naturally occurring systems in northern Australia, Water
Science and Technology, vol. 29, p. 257-266. .
Reference not available.
Norecol Environmental Consultants, 1989. Wetland treatment, in British Columbia Acid Mine
Drainage Task Force, Draft Acid Rock Drainage Technical Guide, Volume 1 ,p. 8-47 to 8-52.
Provides a general overview of wetlands treatment of AMD, including a discussion of the
advantages and disadvantages of wetland treatment systems.
-------
B-22 Appendix B; Acid Mine Drainage
Novotny, Vladimir and Olem, Harvey, 1994. Water Quality: Prevention, Identification and
Management of Diffuse PoBution, Van Nostrand, New York, 1054 pp.
Contains sections that review the retention of sulfur in wetland environments, the types
of constructed wetlands, design considerations and parameters for constructed wetlands,
constituent loadings in wetlands, and metals and toxic chemicals in wetland environments.
Parisi, Dan, Homeman, Jeffrey, and Rastogi, Vijay, 1994. Use of bactericides to control acid
mine drainage from surface operations, International Land Reclamation and Mine Drainage
Conference and Third International Conference on the Abatement of Acidic Drainage, U.S.
Bureau of Mines Special Publication, SP 06B-94, vol. 2, p. 319-325.
Describes three applications of bacterial inhibitors: 1) surface coal mine with highly
pyritic shale overburden in central PA, 2) refuse disposal area in central PA, 3) silver mine in
Idaho where waste rock is used as pit backfill. All studies were successful fiefd tests indicating
that bacterial inhibitors control acid generation and achieve long-term control through controlled
release systems. ;'
Paschke, Suzanne S. and Harrison, Wendy J., 1995. Metal transport between an alluvial
aquifer and a natural wetland impacted by acid mine drainage, Tennessee Park, Leadville,
Colorado, in Tailings and Mine Waste '95, A.A. Balkema, Rotterdam, p. 43-54.
Describes the effects of percolating AMD carried in a surface stream (St. Kevin Gulch)
on regional ground water quality. Discusses the fate of AMD generated from metal mining in
ground water where both oxidizing and reducing conditions are present.
Pfahl, J.C., 1996. Innovative approaches to addressing environmental problems for the upper
Blackfoot mining complex: Voluntary remedial actions, in Managing Environmental Problems at
Inactive and Abandoned Metals Mine Sites, U.S. Environmental Protection Agency Seminar
Publication No. EPA/625/R-95/007, p. 75-80.
Reference not available.
Phillips, Peter, Bender, Judith, Simms, Rachael, Rodriguez-Eaton, Susana, and Britt, Cynthia,
1994. Manganese and ron removal from coal mine drainage by use of a green algae-microbial
mat consortium, in International Land Reclamation and Mine Drainage Conference and Third
International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines Special
Publication, SP 06A-94, vol. 1, p. 99-108.
Results of a field test of three constructed wetlands using native blue-green algae and
limestone or pea gravel substrates at the Fabius Coal Mine, AL. AMD was pre-treated in an
oxidation pond prior to flow into the wetland. Study evaluated feasibility of microbial mat
treatment and assessed mat performance under environmental conditions (seasonal variation,
day-night conditions, etc.).
Plumlee, G., Smith, K.S., Erdman, J., Flohr, M., Mosier, E., and Montour, M., 1994. Geologic
and geochemical controls on metal mobility from the Summitville mine and its downstream
environmental effects, in Abstracts with Programs, Geological Society of America Annual
Meeting, vol. 26, p. A-434 to A-435.
Abstract describes the geochemisty of metal-rich AMD generated from the Summitville
gold mine (CO) and its downstream distribution in the Alamosa River system.
Posey, Harry H., Pendleton, James A., and VanZyl, Dirk, 1995. Proceedings: Summitville
Forum '95, Colorado Geological Survey Special Publication 38, 375 pp.
Contains numerous articles that describe the geochemistry of AMD from the Summitville
gold mine and its downstream effects on the Alamosa River, Terrace Reservoir, and natural
wetlands.
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Appendix B: Acid Mine Drainage B-23
Powers, Thomas J. "Use of Sulfate Reducing Bacterialh Acid Mine Drainage Treatment." U.S.
EPA Risk Reduction Engineering Laboratory. Undated.
Reference not available.
Ptacek, C.J., Inorganic Contaminants in Groundwater and Acid Mine Drainage.
http://gwrp.cciw.ca/gwrp/studies/ptacek/ptacek.html
Describes the mechanisms controlling the transport of metals in tailings impoundments
and underlying aquifers. Contains g reference to In-situ remediation of metal contaminated
groundwater, which describes the use of porous reactive walls to passively treat metals
contaminated groundwater. Lists numerous AMD abstracts published by the author.
Renton, J., A. H. Stiller and T. E. Rymer, 1988, "The Use of Phosphate Materials as
Ameliorants for Acid Mine Drainage," in Conference Proceedings Mine Drainage and Surface
Mine Reclamation, U.S. Bureau of Mines Information Circular 9183,67-75pp.
Reference not available.
Renton, J., AH. Stiller, and T.E. Rymer, 1988, "The Use of Phosphate Materials as Ameliorants
for Acid Mine Drainage," in Conference Proceeding Mine Drainage and Surface Mine
Reclamation, U.S. Bureau of Mines Information Circular 9183, pp. 67-75.
Reference not available.
Rex Chainbelt, Inc. Technical Center. "Treatment of Acid Mine Drainage by Reverse
Osmosis," prepared for the Commonwealth of Pennsylvania, Dept. of Mines and Mineral
Industries and the Federal Water Quality Administration, U.S. Dept. of the Interior; Washington:
for sale by the Superintendent of Documents, U.S. Government Printing Office, 1970.
Reference not available.
Robertson, AM., Blowes, D.W., and Medine, A.J., 1992. Prediction, Prevention, and Control of
Acid Mine Drainage in the West, Workshop, Breckenridge, CO.
Notes, references, papers and presentations from a workshop on AMD.
Robertson, Emily, 1990. Monitoring Acid Mine Drainage, British Columbia Acid Mine Drainage
Task Force, 72 pp.
Examines current monitoring methods at mines with AMD, reviews statistics as they are
applied to water quality data and emphasizes the importance of flow data, uses a set of data
collected daily to elucidate the range of fluctuations that naturally occur, and presents general
guidelines for monitoring untreated water and the receiving environment.
Rowley, Michael V., Warkentin, Douglas D., Van, Vita T., and Piroshco, Beverly M., 1994. The
biosulfide process: Integrated biological/chemical acid mine drainage treatment- results of
laboratory piloting, in International Land Reclamation and Mine Drainage Conference and Third
International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines Special
Publication, SP 06A-94, vol. 1, p. 205-213.
Biosulfide treatment separates chemical precipitation of sulfides from biological
conversion of sulfate tosulfide to produce saleable products. Objective of study was to operate
and evaluate a continuous, integrated system that depended solely on microbially generated
products for treatment of strongly acid water (pH=2.45). Process was demonstrated to be
effective, reliable, and easy to operate through more than 1 year of operation.
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B-24 Appendix B: Acid Mine Drainage
Russell, Charles W., 1994. Acid rock drainage associated with large storm events at the
Zortman and Landusky mines, Phillips County, Montana, in Abstracts with Programs,
Geological Society of America, vol. 26, no. 7, p. A-34.
Describes use of a reclamation cover to control acid-generating reactions, prevent
flushing of reaction products, and establish lower oxidation states to allow implementation of
effective passive treatment systems.
Schultze, Larry E., Zamzow, Monica'J., and Bremner, Paul R., 1994. AMD cleanup using
natural zeolites, in International Land Reclamation and Mine Drainage Conference and Third
International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines Special
Publication, SP 06B-94, vol. 2, p. 341-347.
Experiments using 3 samples of clinoptilolite with varying Na content and an AMD
sample from the Rio Tinto copper mine in northeastern Nevada. Zeolites had differing cation
exchange capacities but all were able to remove metals to drinking water standards. Zeolites
could be regenerated using NaCI solution.
SCRIP Acid Mine Drainage Remediation Project/Passive Treatment Technologies,
http://ctcnet.net/scrip/passive.htm
Contains an online bibliography of papers related to acid mine drainage remediation and
a discussion of passive treatment technologies including oxidizing and reducing wetlands.
Sellstone, Christopher M., 1990. Sequential Extraction of Fe, Mn, Zn, and Cu from Wetland
Substrate Receiving Acid Mine Drainage, Unpubl. M.S. Thesis, Colorado School of Mines,
Golden, CO, 88 pp.
The study attempts to determine the geochemicai phases into which Fe, Mn, Cu, and Zn
are partitioned in a pilot-scale constructed wetland receiving AMD from the Big Five Tunnel in
Idaho Springs, CO by using a geochemicai technique known as sequential extraction.
Sencindiver, J.C. and Bhumbla, O.K., 1988. Effects of cattails (Typha) on metal removal from
mine drainage, in Mine Drainage and Surface Mine Reclamation, U.S. Bureau of Mines
Information Circular 9183, p. 359-368.
Reference not available.
Shelp, Gene, Chesworth, Ward, Spiers, Graeme, and Liu, Liangxue, 1994. A demonstration of
the feasibility of treating acid mine drainage by an in situ electrochemical method, International
Land Reclamation and Mine Drainage Conference and Third International Conference on the
Abatement of Acidic Drainage, U.S. Bureau of Mines Special Publication, SP 06B-94, vol. 2 p
348-355.
Experimentally proved technical feasibility of electrochemical treatment using a block of
massive sulfide-graphite rock as cathode, scrap iron as anode, and AMD from an open-pit iron
mine in Canada as the electrolyte. Electrolyte pH was raised to a maintained level of 5.5,
reduction-oxidation potential was decreased, and iron sulfate precipitate removed Al, Ca, and
Mg from solution.
Sherlock, E.J., Lawrence, R.W., and Poulin, R., 1995. On the-neutralization of acid rock
drainage by carbonate and silicate minerals, Environmental Geology, vol. 25, p. 43-54.
Provides a detailed discussion of the dissolution and neutralizing capacity of carbonate
and silicate minerals related to equilibrium conditions, dissolution mechanism, and kinetics.
Illustrates that differences in reaction mechanisms and kinetics have important implications for
the prediction, control, and remediation of AMD.
-------
Appendix B: Acid Mine Drainage B-25
Silver, Marvin, 1989. Biology and chemistry of generation, prevention, and abatement of acid
mine drainage, in Hammer, Donald A., ed., Constructed Wetlands for Wastewater Treatment,
Lewis Publishers, Chelsea, Ml, p. 753-760.
Reviews the processes that lead to the formation of acid from sulfide and sulfate
minerals, mechanisms by which acid generation can be prevented, and options for abating
AMD.
Singer, P.O. and W. Stumm, 1970, "Acid Mine Drainage: The Rate Determining Step," Science
167;pps1121-1123.
Reference not available.
Siwik, R., S. Payant,and K. Wheeland, "Control of Acid Generation from Reactive Waste Rock
with the Use of Chemicals", in Chalkley, M.E., B.R. Conrad, V.I. Lakshmanan, and K.G.
Wheeland, 1989, Tailings and Effluent Management, Pergamon Press, New York, pgs.
181-193.
Reference not available.
Skousen, J.G., et al., 1990, "Acid Mine Drainage Treatment Systems: Chemicals and Costs," in
Green Lands, Vol. 20, No. 4, pp. 31-37, Fall 1990, West Virginia Mining and Reclamation
Association, Charleston, West Virginia.
Reference not available.
Skousen, J. G., J. C. Sencindiver and R. M. Smith, 1987, "A Review of procedures For Surface
Mining and Reclamatbn in Areas with Acid-producing Materials," in cooperation with The West
Virginia Surface Mine drainage Task Force, the West Virginia University Energy and Water
Research Center and the West Virginia Mining and Reclamation Association, 39pp, West
Virginia University Energy and Water Research Center.
Reference not available.
Skousen, Jeffrey, and Paul Ziemkiwicz, ed. "Acid Mine Drainage: Control & Treatment,"
National Mine Land Reclamation Center. Undated.
(available from the National Mine Land Reclamation Center for $15: (304) 293-2867
ext. 444)
Reference not available.
Skousen, Jeff, 1995. Anoxic limestone drains for acid mine drainage treatment, in Skousen,
Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine Drainage: Control & Treatment, 2nd edition,
National Mine Land Reclamation Center, p. 261-266.
A general review of the operation and effectiveness of anoxic limestone drains in the
treatment of AMD. Includes steps for building an anoxic limestone drain and discusses
important parameters in design and sizing.-
Skousen, Jeff G., 1995. Douglas abandoned mine project: Description of an innovative acid
mine drainage treatment system, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine
Drainage: Control & Treatment, 2nd edition, National Mine Land Reclamation Center, p. 299-
310.
Reviews the historical development of passive treatment strategies including wetlands,
anoxic limestone drains, and alkalinity producing systems. Describes the design and
constructionjjf a two-phase treatment system employed at the Douglas Highwail mine (WV)
that uses two trenches with varying ratios of organic material and limestone. Preliminary results
show that the system raises pH by 3 log units, increases alkalinity from 0 to 200 mg/l, and
effectively removes dissolved Ai, Fe, and Mn from acidified waters.
-------
B-26 Appendix B: Acid Mine Drainage
Skousen, Jeff, Faulkner, Ben, and Sterner, Pat, 1995. Passive treatment systems and
improvement of water quality, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine
Drainage: Control & Treatment, 2"" edition, National Mine Land Reclamation Center, p. 331-
344.
Reviews the function of different passive treatment technologies including aerobic and
anaerobic wetlands, anoxic limestone drains, alkalinity producrig systems, open limestone
channels, limestone ponds, and reverse alkalinity producing systems and the processes by
which they improve water quality. Discusses the effectiveness of backfilling and revegetating
surface mines in reducing acid loads and improving water quality.
Skousen, J., Sexstone, K., Garbutt, K., and Sencindiver, J., 1995. Wetlands for treating acid
mine drainage, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine Drainage: Control &
Treatment, 2nd edition, National Mine Land Reclamation Center, p. 249-260.
A general overview passive wetlands treatment, including important wetlands processes,
alkalinity generation and anoxic limestone drains, design and sizing parameters, and plant
selection for optimum wetlands effectiveness.
Skousen, J., Sexstone, K., Garbutt, K., and Sencindiver, J., 1994. Acid mine drainage
treatment with wetlands and anoxic limestone drains, in Kent, D.M., ed., Applied Wetlands
Science and Technology, Lewis Publishers, Boca Raton, p. 263-281.
Reference not available.
Skousen, Jeffrey and Ziemkiewicz, Paul, 1995. Acid Mine Drainage: Control & Treatment, 2""
edition, National Mine Land Reclamation Center, 362 pp.
Contains 10 papers that deal with aspects of the design, treatment, and effectiveness of
passive treatment systems, most dealing with coal mine AMD, in additbn to multiple papers on
active treatment systems and AMD prevention.
Smith, K.S., 1991. Factors Influencing Metal Sorption onto Iron-rich Sediment in Acid-Mine
Drainage, Unpubl. Ph. D. Dissertation, Colorado School of Mines, Golden, CO.
Reference not available.
Smith, Kathleen S;, Plumlee, GeoffreyS., and Ficklin, Walter H., 1994. Predicting Water
Contamination from Metal Mines and Mining Wastes, U.S. Geological Survey Open-File Report
94-264.
Notes from a workshop presented at the International Land Reclamation and Mine
Drainage Conference and the Third International Conference on the Abatement of Acidic
Drainage in Pittsburgh, PA.
Smith, Teri R., Wilson, Timothy P., and Ineman, Fredrick N., 1991. The relationship of iron
bacteria geochemistry to trace metal distribution in an acid mine drainage system, NE Ohio,
Geological Society of America Abstracts with Programs, v. 23, no. 3, p. 61.
Investigates the relationship between iron bacteria type, abundance, stream
environment, and water/sediment chemistry in acid drainage from a coal strip mine. Concludes
that bacteria exert significant control over the precipitation of Fe-Mn oxyhydroxides, which affect
the distribution of trace metals in effluent.
Sobolewski, A., 1996. Metal species indicate the potential of constructed wetlands for long-
term treatment of mine drainage, Journal of Ecological Engineering, vol. 6, p. 259-271.
Reference not available.
-------
Appendix B: Acid Mine Drainage B-27
Sobolewski, A., 1995. Development of a Zetland treatment system at United Keno Hill Mines,
Eisa, Yukon Territory, Proceedings of the Twentieth Annual British Columbia Mine Reclamation
Symposium, Kamloops, British Columbia, p. 64-73.
Reference not available.
Soboiewski, Andre, Wetlands for Treatment of Mine Drainage.
http://www.enviromine.com/wetlands/Welcome.htm
Contains links to numerous internet sources on acid mine drainage including
constructed wetlands at base and precious metals mines (/wetlands/metal.htm) and examples
of natural and constructed wetlands that are remediating AMD. Also includes a link to a web
page that briefly describes the UK effort to remediate acid mine drainage from Cornish tin
mines (http://www.intr.net/esw/494/uk.htm).
Staub, Margaret W., 1994. Passive Mine Drainage Treatment in a Bioreactor: The Significance
of Flow, Area, and Residence Time, Unpubl. M.S. Thesis, Colorado School of Mines, Golden,
CO. .
Demonstrated the effectiveness of microbiological treatment on acidic mine drainage
water with high metals concentration. Experiments used pilot scale pioreactors constructed
underground at the Eagle Mane Superfund site in Cobrado. The systems removed 95 to 100
percent of the metals.
Steffen, Robertson, and Kirsten, Inc., 1989. Draft Acid Rock Drainage Technical Guide,
Volumes 1 & 2, prepared for the British Columbia Acid Mine Drainage Task Force, BiTech
Publishers, Richmond, British Columbia.
Reference not available.
Stilwell, C.T., 1995. Stream restoration and mine waste management abng the upper Clark
Fork River, in Tailings and Mine Waste '95, A.A. Balkema, Rotterdam, p. 105-107.
Describes an attempt to attenuate AMD from metal mines in a riparian corridor in
Montana. AMD is generated from tailings that were eroded and fluvially redeposited during
flood events. One design uses in situ lime treatment, in which lime is admixed with tailings,
then recontoured and vegetated.
Tarutis, W.J., Jr., Unz, R.F., and Brooks, R.P., 1992. Behavior of sedimentary Fe and Mn in a
natural wetland receiving acidic mine drainage, Pennsylvania, U.S.A., Applied Geochemistry,
vol. 7, p. 77-85.
Reference not available.
-Taufen, Paul M., 1995. A Geochemical Study of Groundwaters and Stream Waters at Two
Mineralized Sites in the Noranda District, Quebec - Application to Mineral Prospecting, Mine
Development, and Environmental Remediation, Unpubl. M.S. Thesis, Colorado School of
Mines, Golden, CO.
Study examines the controls on metal mobility and transport in subsurface and stream
waters. A conceptual hydrogeochemicai model for the production of AMD is provided for the
base-metal-suifide deposits at the abandoned Waite and Amulet mines.
Taylor, H.N., Choate, K.D., and Brodie, G.A., 1993. Storm event effects on constructed
wetlands discharges, in Moshiri, Gerald A., ed., Constructed Wetlands for Water Quality
Improvement, Lewis Publishers, Boca Raton, p. 139-145.
Examines the effects of storm water drainage through two constructed wetlands by
evaluating effluent water quality (total Fe, total Mn, TSS, pH).
-------
B-28 Appendix B: Acid Mine Drainage
Tetcher, J.J., T.T. Phipps, and J.G. Skousen, "Cost Analysis for Treating Acid Mine Drainage
from Coal Mines in the U.S.," in Proceedings Second International Conference on the
Abatement of Acidic Drainage, September 16-18, 1991, Montreal , Canada, Volume 1, pp. 561-
574.
Reference not available.
Titchenell, Troy and Skousen, Jeff, 1995. Acid mine drainage treatment in Greens Run by an
anoxic limestone drain, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds., Acid Mine Drainage:
Control & Treatment, 2°" edition, National Mine Land Reclamation Center, p. 345-356.
Describes the use of anoxic limestone drains to treat three point sources of AMD from
coal mines in WV. Preliminary water quality analyses indicate that the drain is increasing pH,
adding alkalinity, and removing Fe and Al.
Turner, D. and D. McCoy, "Anoxic Alkaline Drain Treatment System, a Low Cost Acid Mine
Drainage Treatment Alternative," National Symposium on Mining, University of Kentucky,
Lexington, Kentucky, May 14-18,1990. pp. 73-75.
Reference not available.
Tyco Laboratories. "Silicate Treatment for Acid Mine Drainage Prevention; Silicate and
Alumina/SBica Gel Treatment of Coal Refuse for the Prevention of Acid Mine Drainage."
Washington: EPA Water Quality Office; for sale by the Superintendent of Documents, U.S.
Government Printing Office, 1971.
Reference not available.
UN/DTCD, 1991. Environmental aspects of non-ferrous mining, in Mining and the Environment
— The Berlin Guidelines, Mining Journal Books, p. 25-52.
Reference not available.
U.S. Bureau of Mines, 1988. Mine Drainage and Surface Mine Reclamation, Volume I: Mine
Water and Mine Waste, U.S. Bureau of Mines Information Circular 9183.
Proceedings of a Conference held in Pittsburgh, PA, April 19-21, 1988. Contains
sections on biological mine water treatment (6 papers), wetland systems for mine water
treatment: case studies (5 papers), and wetland systems for mine water treatment: process and
design (5 papers).
U.S. Bureau of Mines, 1994. International land Reclamation and Mine Drainage Conference
and Third International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines
Special Publication SP 06A-D-94, 4 volumes.
Proceedings of the conference.
U.S. Department of the Interior, Office of Surface Mining Reclamation and Enforcement,
"Managing Hydrologic Information: A Resource for Development of Probable Hydrologic
Consequences (PHC) and Cumulative Hydrologic Impact Assessments (CHIA)," January 31,
1997.
Reference not available.
U.S. Environmental Protection Agency, 1996. Managing Environmental Problems at Inactive .
and Abandoned Metals Mine Sites, U.S. Environmental Protection Agency Seminar Publication
No. EPA/625'R-95/007.
Reference not available.
-------
Appendix B: Acid Mine Drainage B-29
U.S. Geological Survey, The Summitville Mine and its Downstream Effects: An On-line Update
of Open File Report 95-23. http://helios.cr.usgs.gov/summit.web/summit.htm
An update of a previous open-file report on the environmental effects of the Summitville
gold mine. Provides recent information on the impact of AMD on the Alamosa River system
and wetlands in the San Luis Valley.
U.S. Geological Survey, USGS Mine Drainage Newsletter, Technical Forum, U.S. Geological
Survey, http://water.wr.usgs.gov/mine/archive/forum.htmi
Newsletter with short technical articles pertaining to various aspects of acid mine
drainage.
Updegraff, D.M., Reynolds, J.S., Smith, R.L., and Wildeman, T.R., 1992. Bioremediation of
acid mine drainage by a consortium of anaerobic bacteria in a constructed wetland, Abstracts of
Papers, Part 1, American Chemical Society, 203rd National Meeting, San Francisco, CA, April,
1992, Abstract GEOC 174.
Discusses the operation of a wetland constructed in Idaho Springs, CO to treat acid
mine drainage with low pH and high concentrations of heavy metals.
Vile, Melanie A and Weider, R. Kelman, 1993. Alkalinity generation by Fe(lll) reduction versus
sulfate reduction in wetlands constructed for acid mine drainage treatment. Water, Air and Soil
Pollution, vol. 69, p. 425-441.
Study conducted to determine the extent to which ferric iron reduction occurs and the
extent to which sulfate reduction versus ferric iron reduction contributes to alkalinity generation
in 5 wetlands constructed with different organic substrates. Studies conducted over 18 to 22
month period in KY, using AMD from coal mines. Initial results showed that treatment was
effective. However, monitoring revealed a general pattern of diminished ability to reduce
concentrations of H+, soluble Fe, and SO4 during winter months, with failure to reestablish
effective treatment after the second winter. Successful long-term treatment depends on the
continued ability for biological alkalinity generation to balance influent acid load.
Walton, Kenneth C. and Johnson, D. Barrie, 1992. Microbiobgical and chemical characteristics
of an acidic stream draining a disused copper mine. Environmental Pollution, vol. 76, p. 169-
175. . .
Examines downstream changes in pH, metals concentrations, and iron oxidizing
bacteria in AMD as a result of natural processes. Describes the relationships between stream
chemistry and microbiology.
Walton-Day, Katherine, 1996. Iron and zinc budgets in surface water for a natural wetland
affected by acidic mine drainage, St. Kevin Gulch, Lake County, Colorado, in Morganwalp,
David ,W. and Aronson, David A., eds., U.S. Geological Survey Toxic Substances Hydrology
Program—Proceedings of the Technical Meeting, Colorado Springs, CO, September 20-24,
1993, U.S. Geological Survey Water Resources Investigation Report 94-4015, p. 759-764.
Studies the attenuation of iron and zinc from AMD (pH=3.5-4.5) by natural processes in
a wetland. Study shows that approximately 75 percent of total iron is removed by precipitation
of iron hydroxides from influent but that zinc is not removed.
Weider, R. Kelman, 1994. Diel changes in iron (III)/iron (II) in effluent from constructed acid
mine drainage treatment wetlands. Journal of Environmental Quality, vol. 23, p. 730-738.
Study documents dramatic shifts in Fe+3/Fe+2 abundances in effluent from constructed
wetlands that correlates to time of day (high Fe+3 prior to sunset; high Fe+2 prior to sunrise).
Discusses implications for sampling protocols for assessing Fe retention and release. Study
used coal mine AMD in KY.
-------
B-30 Appendix B: Acid Mine Drainage
West Virginia University, Acid Mine Drainage Treatment,
http://www.wvu.edu/~research/techbriefs/acidminetechbrief.html.
An introduction to treatment of acid mine drainage for the novice. Site is maintained by
Dr. Jeff Skousen.
Western Governor's Association, 1996. Final Report of Abandoned Mine Waste Working
Group, prepared for the Federal Advisory Committee to develop on-site innovative technologies
(DOIT), Western Governor's Association, Denver, CO.
Reference not available.
Wetzel, R.G., "Constructed Wetlands: Scientific Foundations are Critical", in Moshiri, Gerald A.,
1993, Constructed Wetlands for Water Quality Improvement, Lewis Publishers, Ann Arbor, pgs.
3-7.
Reference not available.
Whitesall, Louis B., et al. Continental Oil Company, Research and Development Dept.
"Microbiological Treatment of Acid Mine Drainage Waters," prepared for the U.S. Environmental
Protection Agency. Washington: EPA Reseach and Monitoring; for sale by the Superintendent
of Documents, U.S. Government Printing Office, 1971.
Reference not available.
Wildeman, Thomas R.T Filipek, Lorraine H., and Gusek, James, 1994. Proof-of-principle
studies for passive treatment of acid rock drainage and mill tailing solutions from a gold
operation in Nevada, International Land Reclamation and Mine Drainage Conference and Third
International Conference on the Abatement of Acidic Drainage, U.S. Bureau of Mines Special
Publication, SP 06B-94, vol. 2, p.387-394.
Samples of arsenic- and selenium-bearing AMD (pH=2.5) was treated by precipitating
iron hydroxide to remove As, then passively treated in an anaerobic cell using a manure
substrate to remove heavy metals, As and Se to Federal drinking water standards. Additional
metals were removed in a passive aerobic polishing cell.
Wildeman, Thomas R. and Laudon, Leslie, S., 1989. Use of wetlands for treatment of
environmental problems in mining: Non-coal-mining applications, ,in Hammer, Donald A., ed.,
Constructed Wetlands for Wastewater Treatment, Lewis Publishers, Ann Arbor, Ml, p. 221-231.
Reviews the chemistry of metal mine drainage,-cites differences between metal mine
and coal mine drainage, analyzes the geochemistry of metals removal in wetlands, and briefly
summarizes the results of studies at the Big Five Tunnel (CO), Red Lake (ON), Sudbury(ON),
Danka Mine (MN), and Sand Coulee (MT).
Wildeman, Thomas R. and Laudon, Leslie, S., 1988. The use of wetlands for treatment of
environmental problems in mining: Non-coal mining applications, in Proceedings of the U.S.
EPA's Forum on Remediation ofCERCLA Mining Waste Sites, April25, 1989, Ward, Colorado,
p. 42-62.
Provides brief descriptions of the wetlands treatment systems presently in use at six
base and precious metals mines in the U.S. and a detailed case history of the pilot treatment
project at the Big Five Tunnel in Idaho Springs, CO.
-------
Appendix B: Acid Mine Drainage B-31
Willow, Mark A., 1995. pH and Dissolved Oxygen as Factors Controlling Treatment Efficiencies
in Wet Substrate, Bio-Reactors Dominated by Sulfate-Reducing Bacteria, Unpubl. M.S. Thesis,
Colorado School of Mines, Golden, CO.
Experiments were conducted to determine if pH and dissolved oxygen of influent
wastewaters limited the removal of heavy metals from AMD. Results showed that dissolved
oxygen was not a limiting factor but that reduced pH did bwer sulfate reduction.
Witthar, S.R., 1993. Wetland water.treatment systems, in Moshiri, Gerald A., ed., Constructed
Wetlands for Water Quality Improvement, Lewis Publishers, Boca Raton, p. 147-155.
Describes wetland design criteria used to construct treatment system wetlands,
including physical requirements and v/etland flora.
Ziemkiewicz, Paul, Skousen, Jeff, and Lovett, Ray, 1995. Open limestone channels for treating
acid mine drainage: A new look at an old idea, in Skousen, Jeffrey and Ziemkiewicz, Paul, eds.,
Acid Mine Drainage: Control & Treatment, 2"1 edition, National Mine Land Reclamation Center,
p. 275-280. .
Reviews the effectiveness and practical application of open channels armored with
limestone for treating AMD from coal mines. Studied sites include the Brownton, Dola,
Florence, Webster, and Airport channels, ail located in western PA.
Ziemkiewicz, P.P., Skousen, J.G., Brant, D.L., Sterner, P.L., and Lovett, R.J., 1995. Acid mine
drainage treatment with armored limestone in open limestone channels, in Skousen, Jeffrey
and
Ziemkiewicz, Paul, eds., Acid Mine Drainage: Control & Treatment, 2nd edition, National Mine
Land Reclamation Center, p. 281-298.
Reports the results of field and laboratory studies conducted to assess the extent to
which the neutralizing capability of limestone clasts diminishes as a consequence of armoring
by metal precipitates. Found that armoring reduced neutralizing capabilities by 5 to 50 percent.
Ziemkiewicz, P.J. Renton and T. Ryrner, 1991, "Prediction and Control of Acid Mine Drainage:
Effect of Rock Type and Amendment," in Proceedings Twelfth Annual West Virginia Surface
Mine Drainage Task Force Symposium, April 3-4, 1991, Morgantown, West Virginia.,
Reference not available.
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B-32 Appendix B: Acid Mine Drainage
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APPENDIX C
MINING SITES ON THE NATIONAL PRIORITIES LIST
-------
Appendix C: Mining Sites on the National Priorities List
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Appendix C: Mining Sites on the National Priorities List
Table of Contents
C.1 Purpose C-1
C.2 NPL Mining Sites and Smelters as of May 16, 2000 C-1
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Appendix C: Mining Sites on the National Priorities List
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Appendix C
Mining Sites on the National Priorities List
C. 1 Purpose
This appenidix presents the mine sites and smelters listed on the National Priorities List as of
May 16, 2000. It is hoped that this information will provide the user with an idea of the variety
and geographic regions these sites are located in. For more information on a specific site,
please contact the staff in the particular region (see Appendix I for a list of EPA Mining
Contacts).
C.2 NPL Mining Sites and Smelters as of May 16, 2000
Site Name
Atlas Asbestos Mine
Celtor Chemical Works
Iron Mountain Mine
Johns-Manviile Coalinga Asbestos
Leviathan Mine
Lava Cap Mine
Sulphur Bank Mercury Mine
Vasquez Boulevard and I-70
ASARCO, Inc. (Globe Plant)
Eagle Mine
Central City-Clear Creek
California Gulch
Lincoln Park
Smuggler Mountain
Summitville Mine
Smeltertown Site
Uravan Uranium
Cedartown Industries, Inc.
Bunker Hill Mining & Metallurgical
Blackbird Mine
Eastern Michaud Flats
Monsanto
Circle Smelting Corp
DePue/New Jersey Zinc/Mobil Chem Corp
NL Industries/Taracorp Lead Smelter
U.S. Smelter & Lead Refinery Inc.
Cherokee County
National Southwire Aluminum Co. •
NL Industries/Taracorp/Goiden Auto
Torch Lake
East Helena Site
City
State Region NPL Status
Fresno County
Humbolt County
Redding
Fresno
Markleeville
Nevada City
Lake County
Denver
Denver
Minturn/Red cliff
Idaho Springs
Leadville
Canon City
Pitkin County
Rio Grande County
Salida
Uravan
Cedartown
Smelterville
Lemhi County
Pocatello
Soda Springs
Beckemeyer
DePue
Granite City
East Chicago
Cherokee County
Hawesville
St. Louis Park
Houghton County
East Helena
CA
CA
CA
CA
CA
CA
CA
CO
CO
CO
CO
CO
CO
CO
CO
CO
CO
GA
ID
ID
ID
ID
IL
IL
IL
IN
KS
KY
MN
Ml
MT
9
9
9
9
9
9
9
8
8
8
8
8
8
8
8
8
8
4
10
10
10
10
5
5
5
5
7
4
5
5
8
Final
Final
Final
Final
Final
Final
Final
Final
Proposed
Final
Final
Final
Final
Deleted
"Final
Proposed
Final
Final
Final
Proposed
Final
Final
Proposed
Final
Final
Proposed
Final
Final
Deleted
Final
Final
-------
C-2 Appendix C: Mining Sites on the National Priorities List
Site Name
Anaconda Co. Smelter
Basin Mining Area
Mouat Industries
Upper Tenmile Creek Mining Area
Big River Mine Tailings
Oronogo-Duenweg Mining Belt
Carson River Mercury ' • .
Cimarron Mining Company
Cleveland Mill
Homstake Mining Company
Molycorp, Inc.
United Nudear Corp
Li Tungsten Corp.
Ormet Corp.
National Zinc Corp.
Tar Creek (Ottawa County)
Reynolds Metal Company
Fremont Nat. Forest Uranium Mines
Jacks Creek/Sftkin Smelting and Refinery
Palmerton Zinc
Macalloy Corporation
Annie Creek Mine Tailings
Gilt Edge Mine
Whitewood Creek
Ross Metals Inc
Tex-Tin Corp
TRSR Corp.
Jacobs Smelter
Kennecott (North Zone)
Kennecott (South Zone)
Midvale Slag
International Smelting and Refining
Sharon Steel Corp. (Midvale Tailings)
Murray Smelter
U.S. Titanium
ALCOA (Vancouver Smelter)
Commencement Bay/Nearshore Tideflats
Silver Mountain Mine
Midnite Mine
City
Anaconda
Basin
Columbas
Rimini/Helena
St. Francois County
Jasper County
Lyon & Churchill Co
Carizozo
Silver City ,
Cibola County
Questa
McKinley County
Glen Cove
Hannibal
Bartlesville
Ottawa County
Troutdale
Lake County
Maitland
Palmerton
North Charleston
Deadwood
Lead
Whitewood
Rossville
Texas City
Dallas
Stockton
Magna
Copperton
Midvale
Tooele
Midvale
Murray City
Piney River
Vancouver
Tacoma
Loomis
Wellpinit
State
MT
MT
MT
MT
MO
MO
NV
NM
NM
NM
NM
NM
NY
OH
OK
OK
OR
OR
PA
PA
SC
SD
SD
SD
TN
TX
TX
UT
UT
UT
UT
UT
UT
UT
VA
WA
WA
WA
WA
Region
8
8
8
8
7
7
9
6
6
6
6
6
2
5
6
6
10
10
3
3
4
8
8
8
4
6
6
8
8
8
8
8
8
8
3
10
10
10
10
NPL Status
Final
Final
Deleted
Final
Final
Final
Final
Final
Final
Deleted
Proposed
Final
Final
Final
Proposed
Final
Final
Final
Final
Final
Final
Deleted
Proposed
Deleted
Final
Final
Final
Final
Proposed
Proposed
Final
Proposed
Final
Proposed
Final
Deleted
Final
Deleted
Final
-------
Appendix D
General Discussion of
Applicable or Relevant and Appropriate Requirements
At Superfund Mining Sites
-------
Appendix D: General Discussion of Applicable or Relevant and Apprppriate Requirements at
Sunerfund Mininq Sites -
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Appendix D: General Discussion of Applicable or Relevant and Appropriate Requirements at
Superfund Mining Sites
Table of Contents
D.1 Introduction and Organization of the Appendix D-1
D.2 Resource Conservation and Recovery Act D-1
D.2.1 Prerequisites for Applicability of RCRA Requirements D-2
D.2.2 Relevance and Appropriateness of RCRA Requirements D-5
D.2.3 State RCRA Requirements as ARARS D-6
D.2.4 RCRA Standards D-7
D.3 Statutes and Regulations Governing Radioactive Wastes D-12
D.3.1 Regulatory Program Structure D-12
D.3.2 EPA Program \". D-13
D.3.3 NRC Program •;. D-22
D.3.4 DOE Program : D-23
D.4 Clean Water Act D-24
D.4.1 Regulatory Program D-24
D.4.2 Direct Discharge Requirements D-25
D.4.3 Indirect Discharge Requirements D-28
D.4.4 Storm Water Requirements D-30
D.4.5 Dredge and Fill Requirements D-31
0.4.6 Implementation of CWA Requirements at Superfund Mining Sites D-33
D.5 Safe Drinking Water Act D-33
D.5.1 Regulatory Program D-33
D.5.2 Drinking Water Standards D-34
D.5.3 Underground Injection Control Program (40 CFR Part 144) D-36
D.5.4 Sole-Source Aquifer Program. D-37
D.5.5 Wellhead Protection Program D-37
D.5.6 Implementation of the SDWA at Superfund Mining Sites. D-37
D.6 Clean Air Act '. D-38
D.6.1 National Ambient Air Quality Standards for Criteria Pollutants
(40 CFR Part 50). D-38
D.6.2 National Emissions Standards for Hazardous Air Pollutants
(NESHAPs) (40 CFR Part 61) D-41
D.6.3 New Source Performance Standards (NSPS) D-44
D.6.4 State Programs D-44
D.6.5 Implementation of CAA Requirements D-45
D.7 Surface Mining Control and Reclamation Act D-45
D.7.1 Scope D-45
D.7.2 Implementation. D-45
D.8 Fish and Wildlife Coordination Act '. D-46
D.8.1 Prerequisites for Applicability D-46
D.8.2 Standards D-47
D.8.3 Implementation of the Fish and Wildlife Coordination
Act at Superfund Mining Sites D-53
D.9 Executive Order 11990, Protection of Wetlands and Executive Order 11988, Floodplain
Management D-53
D.9.1 Standards (40 CFR 6.302(a) and (b), 40 CFR Part 6, Appendix A) D-54
D.9.2 Applicability of E.O. 11990 and Other Wetlands Protection Requirements. .. D-56
D.9.3 Implementation of Wetlands Protection Requirements at Mining . D-56
D.10 National Historic Preservation Act D-57
D.10.1 Implementing Historic Preservation Requirements D-57
D.10.2 Complying With the Historic Preservation Laws. D-59
D.10.3 Cultural Resources Discovered After Complying with the NHPA D-64
D.10.4 Summary of RPM's Responsibilities to Ensure Compliance with the NHPA. D-65
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Appendix D: General Discussion of Applicable or Relevant and Appropriate Requirements at
Superfund Mining Sites
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Appendix D
General Discussion of
Applicable or Relevant and Appropriate Requirements
At Superfund Mining Sites
D. 1 INTRODUCTION AND ORGANIZATION OF THE APPENDIX
Throughout any remedial action at an abandoned mining and mineral processing site, the site
manager must consider compliance-.with applicable or relevant and appropriate requirements
{ARARs in CERCLA jargon). ARARs are state, local, and federal standards that are directly
applicable or may be considered relevant and appropriate to the circumstances on the site.
These standards are an inherent part of the scoping process, but will affect the long-term
remediation, especially in the setting of cleanup standards as well as in meeting other land use
regulations (e.g., regulation pertaining to wetlands and water resources, floodplains,
endangered and threatened species/critical habitats, coastal zones, cultural resources, wild and
scenic rivers, wilderness areas, and significant agricultural lands). The site manager must be
aware of all potential ARARs and constantly considering other federal state, and local laws,
regulations, and policies that will impact the actions at the site.
This appendix is organized in a statute-by-statute format providing information on the
ARARs that have typically been selected at Superfund mining sites. It should be noted
that the ARARs presented in this section may or may not apply on a site-specific basis
and there may be additional laws and regulations that need to be considered on an
individual site basis. Users of this handbook are strongly encouraged to refer to the
pertinent CERCLA ARARs guidance documents for additional information and guidance.
The structure of each section may vary according to the nature of the regulatory program under
each statute, but the section will generally provide the following information:
• The nature and structure of the regulatory program and
circumstances/conditions/actions that trigger the regulatory requirements;
• The potential applicability or relevance and appropriateness of a requirement for
mining sites;
• A summary of the standards promulgated under the regulatory program; and
• Examples of how the statute/regulation may be an ARAR at a Superfund mining
site.
Several types of ARARs are not included in this appendix because, although they may be
significant at some sites, they do not appear to be issues at the majority of mine waste sites.
For example, PCBs may be found at some historic mine sites, but are not a threat at most sites.
In addition, EPA has published other guidance that specifically addresses these types of ARAR
issues.
D.2 RESOURCE CONSERVATION AND RECOVERY ACT
Many Superfund mining site managers will be required to analyze whether the requirements of
the Resource Conservation and Recovery Act '(RCRA) are ARARs. RCRA ARAR
determinations require knowledge of the nature of the wastes found at these sites and the types
of actions that have been or will be taken at the sites (e.g., capping, removal, treatment).
RCRA Subtitle D (which regulates "solid wastes" that are not hazardous wastes under RCRA -
see definitions below) and Subtitle C (which regulates hazardous waste) are the RCRA
requirements that are most likely to be applicable or relevant and appropriate.
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D-2 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.2.1 Prerequisites for Applicability of RCRA Requirements. Either Subtitle C or Subtitle D
of RCRA will be applicable if:
• .The wastes at the site are solid wastes; and
• The wastes will be actively managed.1
If these two conditions are met, the wastes are subject to at least RCRA Subtitle D. Subtitle C
(in lieu of Subtitle D) will be applicable if these solid wastes are "hazardous wastes" and they
are actively managed. The determination of whether a solid waste is hazardous is key to
determining which RCRA requirements are applicable. Where RCRA Subtitle D or C
standards are not applicable, ttiey may be relevant and appropriate. This determination is
based on the nature of the wastes, a comparison of the objectives of the Superfund action, and
the circumstances and purposes of the RCRA requirements.
Definitions of RCRA "Solid" and "Hazardous" Waste
Solid Waste
In 40 CFR 261.2 solid waste is defined as any discarded (i.e., abandoned, recycled, or
inherently wastelike) material. The regulations also provide that certain materials are excluded
from the definition of solid waste. The excluded materials that may be present at Superfund
mining sites include: source, special nuclear, or byproduct material (as defined by the Atomic
Energy Act of 1954) and materials subjected to in-situ mining techniques that are not removed
from the ground as part of the extraction process (40 CFR 261.4). No RCRA regulations (i.e.,
those of either Subtitle C or D) willbe applicable or relevant and appropriate to these excluded
wastes.
The definition of solid waste includes wastes from the extraction, beneficiation, or processing of
ores and minerals. These wastes will be subject to RCRA Subtitle D, unless they are subject to
regulation under RCRA Subtitle C. (See Highlight D-1 for more information.)
Hazardous Waste
RCRA hazardous wastes are regulated by Subtitle C. A RCRA solid waste is hazardous if it:
• Is not excluded from regulation under Subtitle C; and
• Exhibits the characteristic of ignitability, corrosivity, reactivity, or toxicity; or
• Is listed in 40 CFR 261 Subpart D; or
• Is a mixture of a solid waste and a listed hazardous waste or a mixture of a solid
waste and a characteristic waste that exhibits the characteristic;2 or
• Is a solid waste generated during the treatment, storage, or disposal of a listed
hazardous waste, or is derived from a characteristic waste and exhibits a
characteristic; or
• Is a listed or characteristic waste contained in a non-solid waste matrix.
1 "Active management" includes generation, transport, recycling, treatment, storage, and disposal. See below for more detail.
: EPA has proposed revisions to the "mixture" and "derived-from" rules. EPA will publish a fact sheet discussing these revisions
once they are promulgated.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate Requirements D-3
at Superfund Mining Sites
Several types of mining wastes are excluded from regulation as hazardous wastes under the
mining waste ("Bevill") exclusion (see Highlight D-1 for .details). Based on a 1986 Report to
Congress, EPA determined that all solid wastes from th% extraction or beneficiation of ores and
minerals are covered by the exclusion, and therefore are regulated only by Subtitle D, and
never by Subtitle C. Most mineral processing wastes were removed from the exclusion by two
rulemakings (54 FR 36592 and 55 FR 2322), and these wastes are now potentially subject to
Subtitle C (see Highlight D-2 for definitions of "extraction," "beneficiation," and "mineral
processing"). Only 20 mineral processing wastes are now covered by the Bevill exclusion. On
May 20, 1991, EPA made a final determination not to regulate these 20 wastes. These wastes
are not subject to Subtitle C, but they are subject to Subtitle D.
Therefore, mineral processing wastes not included in the 20 under study are nor covered by the
Bevill exclusion and are subject to Subtitle C regulation, if they meet one of the criteria for being
hazardous discussed above. The criteria most commonly found in mineral processing wastes
that could lead to a determination that they are hazardous are the characteristics of toxicity and
corrosivity. Mineral processing wastes will seldom, if ever, be ignitable or reactive.
One important remaining issue is whether treatment residuals from excluded mining and
mineral processing wastes are themselves excluded under Beviil, or whether they are subject to
Subtitle C regulation if they exhibit a characteristic. This issue has not been explicitly
addressed and will require consultation with appropriate legal staff.
A mineral processing waste may also be considered hazardous if it is a listed RCRA hazardous
waste. There are six listed mineral processing wastes. However, because five of these listings
were remanded, only the listing for K088 (spent potliners from primary aluminum reduction)
may be enforceable.3
Highlight D-1:
The Mining Waste ("Bevill") Exclusion
Under 40 CFR 261.4(b)(7), "solid waste from the extraction, beneficiation and processing of ores and minerals
(including coal), including phosphate rock and overburden from the mining of uranium ore" is excluded from the
definition of hazardous waste, and therefore is not subject to Subtitle C requirements. These wastes are excluded
because implementation of Subtitle C requirements would be unnecessary, technically infeasible, or economically
impracticable due to the types of waste and conditions commonly found at mining sites. These types and conditions
include high volumes of waste with low toxicity and highly mobile constituents, large areas of contamination, and
the arid climate in which many mining sites are located.
Although most mining wastes are still excluded from regulation as hazardous waste (e.g., all extraction and bene-
ficiation wastes), revisions to EPA's interpretation of the Bevill exclusion have resulted in the removal of all but 20
mineral processing wastes from the exclusion. The wastes removed from the exclusion are now subject to
regulation under Subtitle C. Fora complete discussion of the mining waste exclusion and the wastes covered, see
Siinprfund Guide to RCRA Manaaement Requirements for Mineral Processing Wastes, 9347.3-12aFS. August 1991.
' The five other mineral processing wastes (K064. K065. K066, K090, and K091) were listed following their removal from the
mining waste exclusion, but these listings were remanded by a July 1990 Federal Court of Appeals ruling (AMC v. EPA, 31 ERC
1935). Thus, the listings for these wastes may not be currently enforceable. These five wastes are still subject to Subtitle C
requirements if they exhibit a characteristic.
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D-4 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Highlight D-2:
Definitions of Extraction, Beneficiation, and Mineral Processing
Extraction is the process of mining and removing ores and minerals from the ground.
Beneficiation is defined as crushing; grinding; washing; dissolution; crystallization; filtration; sorting; sizing; drying;
sintering; palletizing; briquetting; calcining to remove water and/or carbon dioxide; roasting, autoclaving, and/or
chlorination in preparation for leaching (except where the roasting (and/or autoclaving and/or chlorination)/leaching
sequence produces a final or intermediate product that does not undergo further beneficiation or processing); gravity
concentration; magnetic separation; electrostatic separation; floatation; ion exchange; solvent extraction;
electrowinning; precipitation; amalgamationrand heap, dump, vat, tank, and in situ leaching. (40 CFR 261.4(b)(7))
Mineral processing operations are operations that:
Follow beneficiation of an ore or mineral (if applicable);
Serve to remove the desired product from an ore or mineral, or enhance the characteristics of ores
or minerals or beneficiated ores or minerals;
Use mineral-value feedstocks that are comprised of less than 50 percenfscrap materials;
Produce either a final mineral product or an intermediate to the final product; and
Do not combine the product with another material that is not an ore or mineral, or beneficiated ore
or mineral (e.g., alloying), do not involve fabrication or other manufacturing activities, and do not
involve further processing of a marketable product of mineral processing. (A listing of criteria is
provided in the preamble to the September 1, 1989 rulemaking, 54 FR 36592.)
Hazardous mineral processing wastes are currently subject to all Subtitle C requirements
except the land disposal restrictions (LDRs), because EPA has not yet set treatment standards
for these wastes. Once the Agency sets treatment standards, these wastes will be subject to
the LDRs.
Active Management
For RCRA regulations to be applicable requirements, a solid or hazardous waste must be
actively managed. Active management includes generation, transport, recycling, treatment,
storage, and disposal. Definitions of these activities are provided below and in the RCRA
regulations.
Generation is defined as the act or process of producing hazardous waste or of causing a
hazardous waste to become subject to regulation.
Transportation is defined as the movement of hazardous waste by air, rail, highway, or water.
Recycle is defined as the use, reuse, or reclamation of a material.
Treatment is defined as any method, technique, or process, including neutralization, designed
to change the physical, chemical, or biological character or composition of any hazardous
waste so as to neutralize such waste, or so as to recover energy or material resources from the
waste, or so as to render such waste nonhazardous, or less hazardous; safer to transport,
store, or dispose of; or amenable for recovery, amenable for storage, or reduced in volume.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate Requirements D-5
at Superfund Mining Sites
Storage is defined as the holding of hazardous waste for a temporary period, at the end of
which the hazardous waste is treated, disposed of, or stored elsewhere.
Disposal is defined as the discharge, deposit, injection, dumping, spilling, leaking, or placing of
any solid waste or hazardous waste into or on any land or water so that such solid waste or
hazardous waste or any constituent thereof may enter the environment or be emitted into the air
or discharged into any waters, including groundwaters. (40 CFR 261.10)
In addition, several requirements (e.g., the land disposal restrictions, closure requirements) are
triggered by the land disposal or placement of the wastes. EPA defines placement as actions
that occur when wastes are:
• Consolidated from different areas of contamination (AOCs) into a single AOC;
• Moved outside of an AOC and returned to the same or a different AOC; or
• Excavated from an AOC, placed in a separate unit, such as an incinerator or tank
that is within the AOC, and redeposited into the same AOC.
Equally important, EPA has determined that placement does not occur when wastes are:
• Treated in-situ, including in-situ stabilization and in-situ land treatment (as long as
the treatment is not preceded or followed by movement of wastes that constitutes
placement);
• Capped in place, including-grading prior to capping;
• Consolidated within the AOC; and
• Processed within the AOC (but not in a separate unit, such as a tank) to improve its
structural stability for closure or for movement of equipment over the area.
RCRA Subtitle C is not automatically applicable to mining wastes that are left in place by
response activities (e.g., wastes in slag piles, impoundments) and that are not managed.
However, if the wastes prove to be hazardous, it often is an indication that some type of active
management will be necessary as part of the remedy.
D.2.2 Relevance and Appropriateness of RCRA Requirements.
• RCRA Subtitle C requirements will generally not be relevant and appropriate for
those wastes for which EPA has specifically determined that Subtitle C regulation is
not warranted (i.e., wastes covered by the Bevill exclusion). As noted earlier, most
mineral processing wastes are subject to RCRA Subtitle C. However, the NCP
provides that if site circumstances differ significantly from those that caused EPA to
decide that Subtitle C regulation is not warranted, Subtitle C may be relevant and
appropriate. (See 40 CFR 300). (The circumstances that caused EPA to decide
that Subtitle C regulation is not warranted for wastes covered by the Bevill exclusion
include: the diversity from one mining site to another; the large quantities of waste
found at individual mining sites, and the high aggregate waste quantities for all
mining sites; the relatively low toxicity of mining wastes; and the high costs
associated with regulating mining wastes under Subtitle C.)
• The NCP states that circumstances in which Subtitle C may be relevant and
appropriate include sites containing low volumes of waste or wastes with high
toxicity or highly mobile constituents, location of the site in an area of heavy
precipitation (which could increase the leaching potential), or relatively small areas
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D-6 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
of contamination at the site. (See the preamble to the National Contingency Plan,
55 FR 8743 and 8763 and the Superfund Guide to RCRA Management
Requirements for Mineral Processing Wastes, OSWER Publication No. 9347.3-
12aFS, August 1991 for more information on the relevance and appropriateness of
RCRA Subtitle C requirements.)
• If Subtitle D requirements are not applicable to the action, it is unlikely that they will
be relevant and appropriate.
Even when not all parts of a Subtitle C requirement are ARARs, certain parts of the requirement
may be evaluated to be relevant and appropriate. Where a site manager determines that
RCRA requirements or parts of requirements are ARARs for a site, remedial actions must
comply with these standards. RCRA closure requirements are often likely to be ARARs at
mining sites. In particular, where soil cleanup is part of the remedy, movement of the soil
containing RCRA hazardous waste across a unit boundary will make the closure requirements
for either clean closure or closure in place applicable or relevant and appropriate to the unit into
which the waste is placed. Where closure requirements are determined not to be applicable,
hybrid closure (i.e., a combination of landfill and clean closure options) may be relevant and
appropriate for these sites. Hybrid closure is particularly appropriate where contamination
remaining at the site has low mobility and low toxicity. These conditions are often found at sites
where mining waste is present.
[For a complete discussion on determining if RCRA requirements are ARARs, see the CERCLA
Compliance with Other Laws Manual, Part I and II, Interim Final, (August 1988 and August
1989, respectively).]
D.2.3 State RCRA Requirements as ARARS. The RCRA Subtitle D program is a wholly
state-managed program.4 In most states .(i.e., authorized states), the Subtitle C program is also
administered by the state in lieu of federal regulation. That is, state authorities are used to
issue the permits and enforce regulations for hazardous waste treatment, storage, and disposal
(TSD) facilities. Until a state receives authorization, RCRA regulations are administered and
enforced under federal jurisdiction. Site managers should determine if the state in which the
mining site is located has an authorized RCRA program, and if state requirements are ARARs.
To be authorized under Subtitle C, state programs must be equivalent to federal programs,
consistent with federal and other approved state programs, and must provide adequate
enforcement of compliance with federal regulations. (See 40 CFR Part 271.) state programs
may always contain elements that are more stringent than federal regulations. When federal
regulations are promulgated under RCRA, there are two types of circumstances that may arise
that are relevant to evaluating whether the requirements are ARARs. For regulations
promulgated under authorities prior to the Hazardous and Solid Waste Amendments of 1984
(HSWA), the regulations are not enforceable as federal law in states with authorized RCRA
programs until the state program adopts those regulations (a process that the state generally
must do within two years, although states may do so sooner or may adopt the requirement
under state law or regulations prior to official authorization).5 Examples of these include wastes
1 EPA has promulgated criteria for design and operation of Subtitle D landfills. Additional Subtitle D requirements may also be
promulgated: however, under RCRA reauthorization. States may acquire the authority to issue their own criteria.
% Many States incorporate Federal RCRA changes by referencing Federal regulations in State regulations and then submitting a
formal authorization request.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-7
Requirements at Superfund Mining Sites
that were excluded originally under the Bevill exclusion, but since were studied by Reports to
Congress. For regulations promulgated under HSWA authorities, EPA enforces the regulations
in all states. If an authorized state adopts these regulations, the state assumes enforcement
authority.
In determining if state RCRA requirements are ARARs, site managers do not need to determine
if the state regulations are promulgated, enforceable, or more stringent than federal regulations
(the normal criteria for evaluating whether state requirements are ARARs - see CERCLA
Compliance with Other Laws Manual, Part II, Chapter 7). If the state has an authorized RCRA
Subtitle C program, its requirements^ are ARARs because of the process states must go
through to become authorized, which evaluates these criteria.
D.2.4 RCRA Standards. Once a site manager has determined that a site meets the conditions
discussed above, the following standards should be examined as potential ARARs.
Subtitle D Standards
The Subtitle D program regulates the management of nonhazardous solid waste and is
administered by the states. Under RCRA, states must develop solid waste management plans
that prohibit waste disposal in open dumps and that provide for the closing or upgrading of all
existing dumps. These plans must be "consistent with the minimum requirements" for approved
state programs. In 40 CFR Part 257, EPA establishes criteria for determining which solid waste
disposal facilities and practices pose a potential threat to human health and the environment.
Currently promulgated criteria include restrictions on contamination of surface and groundwater,
releases to air, and safety considerations. Criteria for municipal solid waste landfills can be
found at 40 CFR Part 258. This section addresses location restrictions, operating criteria,
design criteria, groundwater monitoring and corrective actions, closure and post-closure care,
and financial responsibility criteria at municipal solid waste landfills receiving waste after
October 9, 1991. It should be noted that most states have primacy for solid waste programs.
These programs may differ and should be reviewed to determine the applicability to mine waste
(e.g., Utah solid waste regulations and ground-water protection regulations as applied to mine
waste).
Subtitle C Standards
The Subtitle C program regulates the generation, transportation, treatment, storage, and
disposal of RCRA hazardous waste. The following are the primary types of RCRA
requirements that may be ARARs for mining sites, including the basis for the requirement and
specific standards that must be met.
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D-8 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
40 CFR Part 264 Subpart F: Groundwater Protection Requirements
Where aquifers are potentially contaminated by mining sites, 40 CFR Part 264 Subpart F
requirements could be ARARs. These may include:
• The Regional Administrator must set groundwater protection standards and
concentration limits for Appendix VIII and IX hazardous constituents once they are
detected in the groundwater at a hazardous waste disposal facility.
• Concentration limits are based on:
— The background level of each constituent in the groundwater at the time the
limit is specified in the permit;
— Maximum concentration limits for 14 specified hazardous constituents if
background levels are below these standards; or
— An "alternate concentration limit" that can be set by the Regional
Administrator if it is determined that a less stringent standard will protect
public health and the environment.
40 CFR Part 264 Subpart J: Tank Design and Operating Requirements
RCRA defines a tank as "a stationary device, designed to contain an accumulation of
hazardous waste which is constructed primarily of non-earthen materials (e.g., wood, concrete,
steel, plastic) which provide structural support." This definition can include a wide variety of
structures that can be used to store mining wastes. Specific requirements for tanks include:
• The owner or operator must obtain a written assessment of the structural integrity
and acceptability of existing tanks systems and designs for new tank systems,
reviewed by an independent, qualified, registered professional engineer.
• All new tank systems must be enclosed in a full secondary containment system
that encompasses the body of the tank and all ancillary equipment and can prevent
any migration of wastes into the soil. This secondary containment system must be
equipped with a leak detection system capable of detecting releases within 24
hours of release.
• Facilities with existing tank systems must install secondary containment systems
within specified times based on age and waste type.
• Owners or operators may seek from the Regional Administrator both technology-
based and risk-based variances from secondary containment requirements, based
on either: (1) a demonstration of no migration of hazardous waste constituents
beyond the zone of engineering control; or (2) a demonstration of no substantial
present or potential hazard to human health and the environment.
• Annual leak tests must be conducted on non-enterable underground tanks until
such time as an adequate secondary containment system could be installed.
Either an annual leak test or other type of adequate inspection must also be
conducted on enterable types of tanks that do not have secondary containment.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-9
• Inspection requirements have been upgraded to include regular inspection of
cathodic protection systems" and daily inspictidh of entire tank systems for leaks,
cracks, corrosion, and erosion that may lead to releases.
• The owner or operator must remove a tank from which there has been a leak, spill
or which is judged unfit to use. The owner or operator must then determine the
cause of the problem, remove all waste from the tank, contain visible releases,
notify appropriate parties as required by other laws (i.e., CERCLA reportable
quantity requirements),.and certify the integrity of the tank before further use.
• Closure requirements include removing waste, residues, and contaminated liners,
disposing of them as hazardous waste, and conforming with Subparts G and H
(including post-closure of tank if necessary).
• The owner or operator must also comply with general operating requirement's and
with special requirements for ignitable, reactive, or incompatible wastes.
40 CFR Part 264 Subpart K: Surface Impoundment Design and Operating Requirements
Impoundments are a common type of unit into which mining wastes are disposed during active
operations. When included as part of a Superfund site, the following requirements may be
ARARs:
• Each new surface impoundment, each replacement of an existing surface
impoundment unit, and each lateral expansion of an existing surface impoundment
unit must have two or more liners and a leachate collection system between the
liners. [The Regional Administrator may approve an alternative liner design.]
• Owners or operators must comply with groundwater monitoring requirements
under 40 CFR 264 Subpart F, including corrective action, if necessary.
• impoundments must be removed from service if the liquid level suddenly drops or
the dike leaks.
• A surface impoundment may be closed by removing and decontaminating all
hazardous wastes, residues, liners, and subsoils. If all hazardous wastes cannot
be removed or decontaminated, the facility must be capped and post-closure care
provided. An owner or operator may also close the impoundment as a disposal
facility (i.e., solidify ail remaining wastes, cap the facility, and comply with Part 264
post-closure requirements).
40 CFR Part 264 Subpart L: Waste Pile Design and Operating Requirements
Waste piles are a common type of unit into which mining wastes are disposed during active
operations. A pile is defined as "any non-containerized accumulation of solid, nonflowing
hazardous waste that is used for treatment or storage." When included as part of a Superfund
site, the following requirements may be ARARs:
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D-10 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Super-fund Mining Sites
Waste pile owners and operators must:
• Install a liner under each pile that prevents any migration of waste out of the pile
into the adjacent subsurface soil or ground or surface water at any time during the
active life of the pile.
• Provide a leachate collection and removal syste'm.
• Provide a run-on control system and a run-off management system.
• Comply with Subpart F groundwater protection requirements.
• Inspect liners during construction and inspect the wastes at least weekly
thereafter.
• Close the facility by removing or decontaminating all wastes, residues, and
contaminated subsoils (or comply with the closure and post-closure requirements
applicable to landfills if removal or decontamination of all contaminated subsoils
proves impossible).
40 CFR Part 264 Subpart M: Land Treatment Requirements
Owners or operators of facilities that dispose of hazardous waste by land application must:
• Establish a treatment program that demonstrates to the Regional Administrator's
satisfaction that all hazardous constituents placed in the treatment zone will be
degraded, transformed, or immobilized within that zone.
• Conduct a monitoring program to detect contaminants moving in the unsaturated
zone (the subsurface above the water table).
• Continue all operations during closure and post-closure to maximize the
degradation, transformation, or immobilization of hazardous constituents.
40 CFR Part 264 Subpart N: Landfills
A landfill is defined as "a disposal facility or part of a facility where hazardous waste is placed
in or on land and which is not a pile, a-land treatment facility, a surface impoundment, an
underground injection well, a salt dome formation, a salt bed formation, an underground mine,
or a cave." Landfills, which are often used at Superfund sites for hazardous waste disposal,
must meet the following requirements:
• New landfills, new landfills at an existing facility, replacements of existing landfill
units, and lateral expansions of existing landfill units must have two or more liners
and a leachate collection system above and between the liners.
• A landfill must have run-on/run-off control systems and control wind dispersal of
particulates as necessary.
• A landfill must comply with Subpart F groundwater protection requirements.
• Owners or operators of landfills must close each cell of the landfill with a final
cover and institute specified post-closure monitoring and maintenance programs.
• Disposal of bulk or non-containerized liquid hazardous waste and non-hazardous
liquids in a landfill is prohibited.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-11
Requirements at Supetfund Mining Sites
40 CFR Part 264 Subpart X: Standards for Miscellaneous Treatment Units
V " Gf. -^ f'
A miscellaneous unit is defined as a "hazardous waste management unit where hazardous
waste is treated, stored, or disposed of and that is not a container, tank, surface impoundment,
pile, land treatment unit, landfill, incinerator, boiler, industrial furnace, underground injection
well'with appropriate technical standards under 40 CFR part 146, containment building,
corrective action management unit, or unit eligible for a research, development, and
demonstration permit under §270.65." A miscellaneous unit must be located designed,
constructed, operated, maintained,.and closed in a manner that will ensure protection of
human health and the environment' Permits for these units will contain design and operating
requirements, detection and monitoring requirements, and requirements for releases of
hazardous waste or hazardous constituents from the unit. Disposal units must be maintained
during post-closure to ensure protection of human health and the environment.
40 CFR Part 268: Land Disposal Restrictions (LDRs)
These requirements regulate placement of hazardous waste in landfills, surface
impoundments, waste piles, injection wells, land treatment facilities, salt dome formations, salt
bed formations, or underground mines or caves. At this time, no mining wastes are subject to
the LDRs. The LDRs will be applicable for wastes removed from the mining waste exclusion,
once the Agency sets treatment standards for these wastes. For a detailed discussion of the
LDRs at CERCLA sites, see Superfund Compliance with the LDRs, OSWER Directive No.
9347.3, the LDR Guide fact sheet series (OSWER #9347.3-01 FS - 9347.3-08FS), and
Superfund Guide to RCRA Management Requirements for Mineral Processing Wastes,
OSWER #9347.3-12FS, January 1991.
40 CFR Part 264 Subpart G, 265, 270: Closure Requirements
See Highlight D-5 and RCRA ARARs: Focus on Closure Requirements, OSWER #9234.2-
04FS, October 1989.
Highlight D-5:
RCRA as ARARs: Two Example Sites
A former aluminum processing facility site listed on the NPL contains areas of contamination resulting from
treatment, storage, and disposal at the site, including a landfill near the aluminum reduction building. Significant
waste types in the landfill include metallic wastes and spent cathode waste materials containing arsenic. Wastes
containing arsenic have been found to exhibit the toxicity characteristic, and listed waste K088 (spent potliners from
primary aluminum reduction) has been discovered at the site. Because these processing wastes are not covered
by the mining waste exclusion, RCRA Subtitle C requirements are applicable for this site. The RCRA LDRs do not
apply to these wastes, but other Subtitle C requirements (e.g., disposal in a regulated Subtitle C unit) will apply. In
addition, other RCRA requirements, such as design and closure requirements, may apply to actions at this site.
At the Celtor Chemical site in California, where sulfide ore was processed for copper, zinc, and precious metal
extraction, soil and surface water are contaminated with cadmium, heavy metals, and arsenic. RCRA landfill and
surface impoundment closure requirements were considered relevant and appropriate for this site. Consolidation
of wastes and capping or encapsulation with long-term groundwater monitoring may have met these requirements,
but it was uncertain if interceptor trenches and subsurface drains would be able to prevent all subsurface water from
entering the waste management area. Because of this uncertainty, the site manager chose clean closure (i.e.,
removal of the wastes to site-specific action levels that were protective of human health and the environment).
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D-12 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites •
D.3 STATUTES AND REGULATIONS GOVERNING RADIOACTIVE WASTES6
D.3.1 Regulatory Program Structure. Radioactive wastes are regulated primarily by three
agencies: EPA, the Nuclear Regulatory Commission (NRC), and the Department of Energy
(DOE). When radioactive contaminants are present at a site, site managers should evaluate
the standards set by the appropriate agencies as potential ARARs. As discussed below, the
requirements set by the NRC and DOE will be applicable only at sites within their
respective jurisdictions. (The NRC's jurisdiction includes non-DOE sites; DOE's jurisdiction
includes DOE-controlled sites only.) Therefore, the requirements of these agencies may only
be relevant and appropriate at most'Superfund sites. EPA standards for radioactive waste will
be applicable to response actions only under certain circumstances; in most cases, however,
they will be only relevant and appropriate, because the standards were not intended to
regulate inactive Superfund mining sites. The scope of each agency's program is described
below:
• EPA's authorities to set standards for radioactive waste are based on several
statutes, including the Atomic Energy Act, the Clean Air Act, the Uranium Mill
Tailings Radiation Control Act, and RCRA. The requirements consist mainly of
radiation standards for activities involving radioactive materials at certain types of
facilities (e.g., nuclear power plants, active uranium mines, DOE facilities). The
materials regulated are source, byproduct, special nuclear, and naturally occurring
and accelerator-produced radioactive material (NARM), which include natural
uranium and thorium, uranium and thorium mill tailings, enriched uranium, and
naturally occurring radionuclides other than thorium and uranium, such as radium
or wastes from mineral extraction industries. EPA's standards established under
the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA) regulate
management of uranium and/or thorium mill tailings at certain inactive uranium
processing sites and licensed commercial uranium or thorium processing sites. In
addition, RCRA hazardous waste regulations may-apply to hazardous wastes
containing radioactive contaminants.
• NRC licenses the possession and use of source, byproduct, and special nuclear
material at certain facilities. (NARM is not regulated by NRC standards.) NRC's
regulatory program controls the nuclear material operations of the licensees. In
addition, 29 states have entered into agreements with the NRC, under which the
states adopt the NRC's regulatory authority over source, byproduct, and small
quantities of special nuclear material. These state-implemented regulations are
potential ARARs.
• DOE regulates radioactive wastes through internal orders that establish
requirements for radiation protection and radioactive waste management. These
requirements apply only to facilities within DOE's jurisdiction, such as national
laboratories and certain inactive sites associated with the Formerly Utilized Sites
Remedial Action Program (FUSRAP), the Uranium Mill Tailings Remedial Action
Program (UMTRAP), the Grand Junction Remedial Action Program (GJAP), and
the Surplus Facilities Management Program (SFMP). Because DOE orders are
developed for internal DOE use, they are not promulgated regulations and are not
potential ARARs for Superfund sites, unless the site is under DOE jurisdiction.
* The authority for regulating radioactive wastes is derived from several statutes and regulations. This section discusses the
regulatory program formed by these laws.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-13
Requirements at Superfund Mining Sites
However, where the DOE orders are more stringent or cover areas not addressed
by existing ARARs, they may be considered for Superfund actions as "to-be-
considered (TBC)" information.
In determining which of the requirements listed above are potential ARARs for a mining site
with radioactive contamination, site managers should consider three factors:
• The type of wastes at the site and the operations that occurred at the site to
generate the waste;
• The agency that has jurisdiction over the site; and
• The regulations that establish standards that are most protective, or (if relevant
and appropriate) most appropriate given site conditions.
Highlight D-6 summarizes the potential ARARs for various radioactive waste types and agency
jurisdictions.
D.3.2 EPA Program. EPA regulations for radioactive wastes include those promulgated
under the Clean Air Act (40 CFR Part 61), the Safe Drinking Water Act (40 CFR Part 141), the
Atomic Energy Act (40 CFR Part 190), UMTRCA (40 CFR Part 192), and in 40 CFR Part 440.
These standards may be ARARs for both EPA sites as well as sites that are not under EPA
jurisdiction (e.g., DOE and NRC sites).
40 CFR Part 61: National Emissions Standards for Hazardous Air Pollutants (NESHAPs)
The standards in 40 CFR Part 61, established under the authority of the Clean Air Act,
regulate radionuclide emissions to the air from various sources (i.e., active underground
uranium mines, certain DOE facilities, certain NRC-licensed facilities and non-DOE federal
facilities, and active NRC-licensed uranium mill tailings sites). Each source is addressed in a
different Subpart. As explained below, most of the Subparts will only be relevant and
appropriate to the cleanup of Superfund mining sites.
Subpart B: Standards for Active Underground Uranium Mines
• An owner or operator of an underground uranium mine shall install and maintain
bulkheads (air-restraining barriers) to control radon-222 and radon-222 decay
products from abandoned and temporarily abandoned areas of the mine.
Because Subpart B standards regulate active mines, they are unlikely to be applicable to
Superfund cleanup actions. However, they may be relevant and appropriate if the response
occurs at an underground uranium mine, or a site where radon-222 or radon-222 decay
products are present.
Subpart H: Standards for DOE Facilities
• Emissions of radionuclides to air from all facilities owned or operated by DOE
(except facilities regulated under 40 CFR Part 61 Subpart B, 191, or 192) shall not
exceed those amounts that would cause any member of the public to receive in
any year an effective dose equivalent of 10 mrem/yr.
• Doses from radon-222 and its respective decay products are excluded from these
limits.
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D-14 Appendix D: General Discussion of Applicable or Relevant and Appropriate Requirements at Superfund Mining Sites
Highlight D-6: Radioactive Waste Regulations as ARARs
Waste Type
Radon
Radionuclides
Uranium mill
tailings
Uranium,
radium, and
vanadium ores
Byproduct,
source, and
special nuclear
material
Standard
• 40CFRPart61
Subpart B
• 40 CFR Part 192
Subparts A - E
• 40 CFR Part 61
Subpart H
Subpart I
« 40 CFR Part 141
• 40 CFR Part 190
• 40 CFR Part 61
Subpart W
• 40 CFR Part 192
Subparts A - C
Subparts D and E
• 40 CFR Part 440
Subpart C
• 10 CFR Parts 30,
40, & 70
Summary
Clean Air Act NESHAPs; Standards for active
underground uranium mines
UMTRCA standards
Clean Air Act NESHAPs; Radionuclide emission
standards for DOE facilities
Clean Air Act NESHAPs; Radionuclide emission
standards for NRC and non-DOE federal facilities
SDWA Maximum Contaminant Levels
Radiation dose limits for nuclear power operations
Clean Air Act NESHAPs; Tailings impoundments
disposal standards for active NRC-licensed uranium
mill tailings sites
UMTRCA standards for designated inactive uranium
processing sites
UMTRCA standards for active commercial licensed
uranium or thorium processing sites
Radionuclide concentration limits for surface water
discharges of radioactive waste
NRC licensing requirements for possession and use
of byproduct, source, and special nuclear material,
respectively
Potential Applicability (for sites under all
agency jurisdictions, unless otherwise
noted)
Relevant and appropriate only
Relevant and appropriate only
Applicable for DOE sites, relevant and
appropriate for EPA sites
Applicable for NRC-licensed sites and non-
DOE federal sites, relevant and appropriate
for EPA sites
Applicable
Relevant and appropriate
Relevant and appropriate only
Relevant and appropriate only
Applicable for active commercial processing
sites licensed by NRC or state; otherwise,
relevant and appropriate
Possibly applicable, probably relevant and
appropriate
Applicable for NRC-licensed sites, relevant
and appropriate for non-licensed sites
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Waste Type
Ore-processing
residues
containing > 5
pCi/g radium
Standard
• 40 CFR Part 192
Subparts A - E
Summary
UMTRCA standards
Potential Applicability (for sites under all
agency jurisdictions, unless otherwise
noted)
^SSSSSS
Relevant and appropriate only
Mixed
radioactive and
hazardous
waste
• RCRA Subtitle C
RCRA requirements for management of hazardous
waste (for hazardous components of mixed waste)
Applicable
All radiation
sources
• 10 CFR Part 20
NRG standards for protection against radiation
Applicable for NRC sites, relevant and
appropriate for EPA and DOE sites
10 CFR Part 61
NRC licensing requirements for land disposal of
radioactive waste
Potentially applicable for NRC sites,
relevant and appropriate for EPA sites
• DOE Internal
orders
DOE requirements for radiation protection and
radioactive waste management
Applicable for DOE sites, To-Be-Considered
for sites under other agency jurisdiction
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D-16 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Subpart H standards are potentially applicable at sites with airborne emissions of
radionuclides, where DOE is the lead agency. Where EPA is the lead agency, these
requirements may be relevant and appropriate.
Subpart I: Standards for NRC-Licensed Facilities and Non-DOE Federal (e.g., DOD)
Facilities
• Emissions of radionuclides including iodine to the ambient air from facilities shall
not exceed those amounts that would cause any member of the public to receive in
any year an effective dose equivalent of 10 mrem/yr. Emissions of iodine to the
ambient air from facilities.shall not exceed those amounts that would cause any
member of the public to receive in any year an effective dose equivalent of 3
mrem/yr.
• Doses from radon-222 and its respective decay products are excluded from these
limits.
Subpart I standards are potentially applicable at sites with NRC- (or state-) licensed or non-
DOE federal sites with airborne emissions of radionuclides. Where EPA is the lead agency,
these requirements may be relevant and appropriate.
Subpart W: Standards for NRC-Licensed Uranium Mill Tailings Sites During Their
Operational Period
• Phased or continuous disposal is required for all new tailings impoundments at
licensed uranium mill sites during their operational period.
Because they regulate active uranium mill tailings sites, Subpart W standards are unlikely to
be applicable to Superfund cleanup actions. However, they may be relevant and appropriate if
the response occurs at a uranium mill site.
40 CFR Part 141: Safe Drinking Water Act (SDWA) Maximum Contaminant Levels
(MCLs)
Maximum Contaminant Levels (MCLs) have been set for radionuclides in the form of
radioactivity concentration limits for certain alpha-emitting radionuclides in drinking water and
as an annual dose limit for the ingestion of certain beta/gamma-emitting radionuclides. The
standards are:
Radionuclide
Gross alpha particle
activity
Gross beta particle activ-
ity
Radium 226 and 228 (to-
tal)
MCL
15 pCi/l
4 mrem/yr
5 pCi/l
For remedial actions addressing ground or surface waters that are potential sources of
drinking water and that are contaminated with radionuclides, MCLs may be relevant and
appropriate.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-17
40 CFR Part 190: Environmental Radiation Protection Standards for Nuclear Power
Operations (including uranium mill sites) '
Applicability
These standards apply to normal operations and planned discharges from nuclear power
operations (i.e., uranium milling, production of uranium hexafluoride, uranium enrichment,
uranium fuel fabrication, operations of nuclear power plants using uranium fuel, and
reprocessing of spent fuel), not cleanup actions such as those conducted under CERCLA.
Therefore, they will not be applicable for Superfund mining sites. However, they may be
relevant and appropriate to releases of radionuclides and radiation during the cleanup of
radioactively contaminated sites. The standards address releases to all media and all potential
exposure pathways, but do not apply to doses caused by radon and its daughters.
Standards
• Operations within the uranium fuel cycle (e.g., uranium milling, uranium enrich-
ment) shall be conducted in a manner that limits the annual dose received by any
member of the public to 25 mrem to the whole body, 75 mrem to the thyroid, and
25 mrem to any other organ.
40 CFR Part 192: Health and Environmental Protection Standards for Uranium and
Thorium Mill Tailings
UMTRCA standards govern the stabilization, disposal, and control of uranium and thorium mill
tailings. Site managers at CERCLA mining sites should consider these standards as potential
ARARsif:
• The site is an active commercial uranium or thorium processing site licensed by
the NRG or a state;
• Uranium or thorium mill tailings are present (excluding inactive sites designated
under UMTRCA - see below for further information);
• Radium or radon gas contamination is present; or
• Materials other than, but similar to, uranium or thorium mill tailings (i.e., radium
components of copper, zinc, aluminum, and other ore-processing residues,
contaminated soil, or any other waste containing more than 5 picocuries/gram of
radium) are present.
Applicability
UMTRCA standards, which are promulgated in 40 CFR Part 192 Subparts A - E, regulate two
categories of uranium and thorium processing sites:
• Subparts A, B, and C govern 24 inactive uranium processing sites designated for
remediation by DOE under UMTRCA. These Subparts cover releases of radon
from mill tailings and cleanup of residual radioactive material from land and
buildings, and include supplemental standards.
• Subparts D and E regulate active commercial uranium or thorium processing sites
licensed by the NRC or a state. The standards include requirements for general
design, operation and closure of the sites.
Criteria for applying supplemental standards: (40 CFR 192.21). Supplemental standards
may be applied if any of the following circumstances exists:
• Remedial actions would pose a clear and present risk of injury to workers or to
members of the public notwithstanding reasonable measures to avoid or reduce
risk;
.• Remedial actions would create environmental harm that is long-term, manifest, and
grossly disproportionate to health benefits that may reasonably be anticipated;
• The estimated costs of cleaning up land are unreasonably high relative to the long-
term benefits, and the residual radioactive materials do not pose a clear present or
future hazard;
• The cost of cleaning up a building is clearly unreasonable high relative to the
benefits;
• There is no known remedial action; or
• Radionuclides other than radium-226 and its decay products are present in signifi-
cant quantities and concentrations.
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D-18 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Subparts A, B, and C are never applicable at CERCLA mining sites, because releases of
source, byproduct, or special nuclear material (i.e., natural uranium and uranium mill tailings)
at the 24 designated sites covered by these standards are excluded from CERCLA response
actions by CERCLA section 101(22)(C). Instead, DOE conducts cleanup actions at these sites
under the authority of UMTRCA, Title I, section 102. However, Subparts A, B, and C may be
relevant and appropriate at CERCLA sites if:
• Uranium or thorium mill tailings are present, but the site is not one of the 24
inactive sites designated under UMTRCA;
• The site contains materials other than, but similar to, uranium or thorium mill
tailings (i.e., radium components of copper, zinc, aluminum, and other ore-
processing residues, contaminated soil, or any other waste containing more than 5
picocuries/gram of radium); or
• Radon decay products or gamma radiation are present.
Site managers should be aware, however, that the radon level standards will only be relevant
and appropriate if the elevated radon levels are caused by human activity, because CERCLA
section 104(a)(3)(A) and (B) prohibits Superfund response to releases of a naturally occurring
substance "in its unaltered form" (such as naturally occurring radon).
D-20 Appendix D: General Discussion of Applicable or Relevant and Appropriate
D-22 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.3.3 NRC Program. NRC regulations for radioactive wastes include those found in 10 CFR
Parts 20, 61, 30, 40, and 70. They may be applicable to sites licensed by the NRC to possess
and use source, byproduct, and special nuclear material, and they may be relevant and
appropriate for non-licensed sites.
10 CFR Part 20: Standards for Protection Against Radiation
Applicability
These standards are potentially applicable to CERCLA actions at NRC-licensed facilities.
They may also be relevant and appropriate to CERCLA actions at radioactively contaminated
sites not licensed by the NRC.
Standards
Permissible dose levels, radioactivity concentration limits for effluents, precautionary
procedures, and waste disposal requirements for NRC licensees.
• Protection of workers in restricted areas: a variety of radiation exposure limits,
including dose limit of 1.25 rem/quarter to whole body. (10 CFR Part 20 Subparts
C and G)
• Protection of the public: Radiation exposure is limited to
whole body dose of 0.1 rem/year
— 0.002 rem/hour
— the dose limits in 40 CFR Part 190 for environmental radiation standards.
(10 CFR 20.1301)
• Discharge to air and water: Discharges must meet radionuclide-specific
concentration limits in 10 CFR Part 20, Appendix B.
• Waste treatment and disposal: include concentration limits for disposal into
sewers and for incineration. (10 CFR Part 20, Appendix B)
10 CFR Part 61: Licensing Requirements for Land Disposal of Radioactive Waste
Applicability
Because these standards regulate new NRC-licensed land disposal facilities, they are not
applicable to previously closed low-level waste disposal sites, including existing CERCLA sites
containing low-level radioactive waste. The performance objectives and technical
requirements of 10 CFR Part 61 may be relevant and appropriate to existing CERCLA sites
containing low-level radioactive waste, if the waste will be left on site permanently. However,
radioactive wastes at CERCLA sites often fall outside the definition of wastes covered by Part
61, particularly when naturally occurring and accelerator-produced radioactive material
(NARM) is involved.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-19
Subpart B: Standards for Cleanup of Land and Buildings Contaminated with Residual
Radioactive Materials from Uranium Processing Sites
Concentration limits for cleanup of radium-226 in land at a processing site: (40 CFR
192.12 (a)). Remedial action shall be conducted so as to provide reasonable assurance that,
as a result of residual radioactive materials from any designated processing site, the
concentration of radium-226 in land averaged over any area of 100 m2 does not exceed the
background level by more than:
• 5 pCi/g, averaged over.the first 15 cm of soil below the surface; and
• 15 pCi/g, averaged over 15 cm thick layers of soil more than 15 cm below the
surface.
Concentration limits for cleanup of radon decay products and gamma radiation in
habitable or occupied buildings at a processing site: (40 CFR 192.12(b)). Remedial
action shall be conducted so as to provide reasonable assurance that, as a result of residual
radioactive materials from any designated processing site, in any occupied or habitable
building:
• The objective of remedial action shall be, and reasonable effort shall be made to
achieve, an annual average (or equivalent) radon decay product not to exceed
0.02 WL. In any case, the radon decay product concentration (including
background) shall not exceed'0.03 WL; and
• The level of gamma radiation shall not exceed the background level by more than
20 microroentgens/hour.
Subpart C: Supplemental Standards Thai May Be Applied if Certain Circumstances
Exist At a Site
Criteria for applying supplemental standards: (40 CFR 192.21). Supplemental standards
may be applied if any of the following circumstances exists:
• Remedial actions would pose a clear and present risk of injury to workers or to
members of the public notwithstanding reasonable measures to avoid or reduce
risk;
.• Remedial actions would create environmental harm that is long-term, manifest, and
grossly disproportionate to health benefits that may reasonably be anticipated;
• The estimated costs of cleaning up land are unreasonably high relative to the long-
term benefits, and the residual radioactive materials do not pose a clear present or
future hazard;
• The cost of cleaning up a building is clearly unreasonable high relative to the
benefits;
• There is no known remedial action; or
• Radionuclides other than radium-226 and its decay products are present in signifi-
cant quantities and concentrations.
mixture of RCRA hazardous waste and source, byproduct, or special nuclear material, RCRA
may apply to the non-radioactive component of that waste. The radioactive component is
regulated under the Atomic Energy Act. [See the section on the applicability of RCRA for more
information on RCRA requirements.]
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D-20 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
• The groundwater meets one of the following criteria: (1) the concentration of total
dissolved solids is in excess of 10,000 mg/l, or (2) widespread, ambient
contamination not due to activities involving residual radioactive materials from a
designated processing sites exists that cannot be cleaned up using treatment
methods reasonably employed in public water systems, or (3) the quantity of water
D-22 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.3.3 NRC Program. NRC regulations for radioactive wastes include those found in 10 CFR
Parts 20, 61, 30, 40, and 70. They may be applicable to sites licensed by the NRC to possess
and use source, byproduct, and special nuclear material, and they may be relevant and
appropriate for non-licensed sites.
10 CFR Part 20: Standards for Protection Against Radiation
Applicability
These standards are potentially applicable to CERCLA actions at NRC-licensed facilities.
They may also be relevant and appropriate to CERCLA actions at radioactively contaminated
sites not licensed by the NRC.
Standards
Permissible dose levels, radioactivity concentration limits for effluents, precautionary
procedures, and waste disposal requirements for NRC licensees.
• Protection of workers in restricted areas: a variety of radiation exposure limits,
including dose limit of 1.25 rem/quarter to whole body. (10 CFR Part 20 Subparts
C and G)
• Protection of the public: Radiation exposure is limited to
— whole body dose of 0.1 rem/year
- 0.002 rem/hour
— the dose limits in 40 CFR Part 190 for environmental radiation standards.
(10 CFR 20.1301)
• Discharge to air and water: Discharges must meet radionuclide-specific
concentration limits in 10 CFR Part 20, Appendix B.
• Waste treatment and disposal: Include concentration limits for disposal into
sewers and for incineration. (10 CFR Part 20, Appendix B)
10 CFR Part 61: Licensing Requirements for Land Disposal of Radioactive Waste
Applicability
Because these standards regulate new NRC-licensed land disposal facilities, they are not
applicable to previously closed low-level waste disposal sites, including existing CERCLA sites
containing low-level radioactive waste. The performance objectives and technical
requirements of 10 CFR Part 61 may be relevant and appropriate to existing CERCLA sites
containing low-level radioactive waste, if the waste will be left on site permanently. However,
radioactive wastes at CERCLA sites often fall outside the definition of wastes covered by Part
61, particularly when naturally occurring and accelerator-produced radioactive material
(NARM) is involved.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-19
Subpart B: Standards for Cleanup of Land and Buildings Contaminated with Residual
Radioactive Materials from Uranium Processing Sites
Concentration limits for cleanup of radium-226 in land at a processing site: (40 CFR
192.12 (a)). Remedial action shall be conducted so as to provide reasonable assurance that,
as a result of residual radioactive materials from any designated processing site, the
concentration of radium-226 in land averaged over any area of 100 m2 does not exceed the
background level by more than:
5 pCi/g, averaged over.the first 15 cm of soil below the surface; and
• 15 pCi/g, averaged over 15 cm thick layers of soil more than 15 cm below the
surface.
Concentration limits for cleanup of radon decay products and gamma radiation in
habitable or occupied buildings at a processing site: (40 CFR 192.12(b)). Remedial
action shall be conducted so as to provide reasonable assurance that, as a result of residual
radioactive materials from any designated processing site, in any occupied or habitable
building:
• The objective of remedial action shall be, and reasonable effort shall be made to
achieve, an annual average (or equivalent) radon decay product not to exceed
0.02 WL. In any case, the radon decay product concentration (including
background) shall not exceed ^0.03 WL; and
• The level of gamma radiation shall not exceed the background level by more than
20 microroentgens/hour.
Subpart C: Supplemental Standards That May Be Applied if Certain Circumstances
Exist At a Site
Criteria for applying supplemental standards: (40 CFR 192.21). Supplemental standards
may be applied if any of the following circumstances exists:
• Remedial actions would pose a clear and present risk of injury to workers or to
members of the public notwithstanding reasonable measures to avoid or reduce
risk;
.• Remedial actions would create environmental harm that is long-term, manifest, and
grossly disproportionate to health benefits that may reasonably be anticipated;
• The estimated costs of cleaning up land are unreasonably high relative to the long-
term benefits, and the residual radioactive materials do not pose a clear present or
future hazard;
• The cost of cleaning up a building is clearly unreasonable high relative to the
benefits;
• There is no known remedial action; or
• Radionuclides other than radium-226 and its decay products are present in signifi-
cant quantities and concentrations.
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D-20 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites -
• The groundwater meets one of the following criteria: (1) the concentration of total
dissolved solids is in excess of 10,000 mg/l, or (2) widespread, ambient
contamination not due to activities involving residual radioactive materials from a
designated processing sites exists that cannot be cleaned up using treatment
methods reasonably employed in public water systems, or (3) the quantity of water
reasonably available for sustained continuous use is less than 150 gallons per day.
Supplemental Standards (40 CFR 192.22). On a site-specific basis, supplemental standards
may be applied in lieu of the standards of Subparts A and B, if any of the criteria listed above
applies. The implementing agency.must select and perform remedial actions that come as
close to meeting the otherwise applicable standard as is reasonable. If radionuclides other
than radium-226 and its decay products are present in significant quantities and
concentrations, this residual radioactivity must be reduce to levels that are as low as is
reasonably achievable (ALARA) and conform to the standards of Subparts A and B to the
maximum extent practicable. The implementing agency may make general determinations
concerning remedial actions under this section that will apply to all locations with specified
characteristics, or they may make a determination for a specific location. In certain situations
the implementing agencies shall apply any remedial actions for the restoration of
contamination of groundwater by residual radioactive materials that is required to assure, at a
minimum, protection of human health and the environment. The implementing agencies may
also need to ensure that current and reasonably projected uses of the affected groundwater
are preserved.
Standards for Licensed Commercial Uranium or Thorium Processing Sites
Subpart D (for uranium) and Subpart E (for thorium): Standards for Management of
Uranium and Thorium Byproduct Materials (i.e., mill tailings)
The standards of these Subparts apply to management of uranium and thorium byproduct
materials during and following processing of uranium ores, as well as to restoration of disposal
sites following the use of such sites under section 84 of the Atomic Energy Act (AEA).
The standards (see 40 CFR 192.32 - 192.33) incorporate the general design, construction,
operation, closure, and corrective action requirements of RCRA. The standards supplement
the groundwater protection standards under RCRA by adding molybdenum and uranium to the
list of hazardous constituents in 40 CFR 264.93 and by specifying concentration limits for
radioactivity.
Implementation of UMTRCA Standards
Site managers may find large amounts of wastes for which UMTRCA standards are ARARs in
waste piles at mining sites or in disposal areas near mining sites. Because many of the sites
for which these standards are relevant and appropriate have been abandoned,for many years,
contamination may have migrated to areas surrounding disposal sites. For example, wind may
have blown contaminated material to other locations, or contaminated soil may have been
used as fill or foundation for buildings and residential areas nearby. UMTRCA standards may
be relevant and appropriate for wastes in these areas as well as for the original mining
or mineral processing site.
CERCLA response actions for which Subparts A and B are relevant and appropriate must
bring the levels of the affected wastes below those specified in the standards. Actions for
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-21
which Subparts D and E are ARARs must meet the requirements given in those sections.
Remedies required to meet the standards of 40 CFR 192 may include excavation and of
contaminated material, capping, installation of radon reduction systems (if buildings are
contaminated with radon gas due to the mining wastes), and institutional controls.
Highlight D-7:
UMTRCA Standards (40 CFR Part 192) as ARARs:
Two Example Sites
The MontclairfWest Orange Radium site in.New Jersey is a residential neighborhood contaminated with radioactive
waste materials suspected to have originated from radium processing or utilization facilities located nearby.
Radium-contaminated soil was used for fill and mixed with cement for sidewalks and foundations. The primary
contaminant of concern is radium-226, which decays to radon gas. The requirements of 40 CFR Part 192 Subpart
B, cleanup standards for land and buildings contaminated with uranium mill tailings, are relevant and appropriate
for this site.
The Monticello Vicinity Properties site in Utah is a federally owned, abandoned vanadium and uranium mill site in
a primarily residential area. The site; as part of the Surplus Facilities Management Program, is designated for
remedial action by DOE. It is also included on the NPL and therefore must comply with CERCLA requirements to
meet ARARs. Approximately 100,000 yd3 of contaminated construction debris and wind-blown deposited
contamination is estimated to be within the site. The primary contaminants of concern are thorium-230, radium-226,
and radon-222 contained in vanadium and uranium mill tailings in the construction debris. Although the mill.site is
located on federal government property and is not subject to UMTRCA, the standards promulgated in 40 CFR Part
192 Subparts A, B, and C are relevant and appropriate for remediation of the vicinity properties. Therefore, the
stabilization, disposal, and control requirements of these Subparts must be met.
40 CFR Part 440 Subpart C: Guidelines and New Source Performance Standards for Ore
Mining and Dressing Point Source Category Effluent Limitations
Applicability
Radionuclide concentration limits in 40 CFR Part 440 are applicable to discharges from certain
kinds of mines and mills. They may be relevant and appropriate to CERCLA actions involving
discharges to surface waters of radioactively contaminated waste from other kinds of sites.
These standards are more stringent than the NRC's concentration limits for discharges of
uranium and radium (10 CFR Part 20). Therefore, when both 40 CFR Part 440 and 10 CFR
Part 20 are ARARs for a site, the concentration limits in 40 CFR Part 440 will take precedence.
Standards
Radionuciide concentration limits for liquid effluents from facilities that extract and
process uranium, radium, and vanadium ore.
RCRA Subtitle C: Regulations for the Management of Mixed Hazardous Waste
Source, byproduct, and special nuclear material are excluded from the definition of solid waste
under RCRA. These wastes are regulated by the NRC and DOE. However, if a waste is a
mixture of RCRA hazardous waste and source, byproduct, or special nuclear material, RCRA
may apply to the non-radioactive component of that waste. The radioactive component is
regulated under the Atomic Energy Act. [See the section on the applicability of RCRA for more
information on RCRA requirements.]
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D-22 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.3.3 NRC Program. NRC regulations for radioactive wastes include those found in 10 CFR
Parts 20, 61, 30, 40, and 70. They may be applicable to sites licensed by the NRC to possess
and use source, byproduct, and special nuclear material, and they may be relevant and
appropriate for non-licensed sites.
10 CFR Part 20: Standards for Protection Against Radiation
Applicability
These standards are potentially applicable to CERCLA actions at NRC-licensed facilities.
They may also be relevant and appropriate to CERCLA actions at radioactively contaminated
sites not licensed by the NRC.
Standards
Permissible dose levels, radioactivity concentration limits for effluents, precautionary
procedures, and waste disposal requirements for NRC licensees.
• Protection of workers in restricted areas: a variety of radiation exposure limits,
including dose limit of 1.25 rem/quarter to whole body. (10 CFR Part 20 Subparts
C and G)
• Protection of the public: Radiation exposure is limited to
— whole body dose of 0.1 rem/year
- 0.002 rem/hour
the dose limits in 40 CFR Part 190 for environmental radiation standards.
(10 CFR 20.1301)
• Discharge to air and water: Discharges must meet radionuclide-specific
concentration limits in 10 CFR Part 20, Appendix B.
• Waste treatment and disposal: Include concentration limits for disposal into
sewers and for incineration. (10 CFR Part 20, Appendix B)
10 CFR Part 61: Licensing Requirements for Land Disposal of Radioactive Waste
Applicability
Because these standards regulate new NRC-licensed land disposal facilities, they are not
applicable to previously closed low-level waste disposal sites, including existing CERCLA sites
containing low-level radioactive waste. The performance objectives and technical
requirements of 10 CFR Part 61 may be relevant and appropriate to existing CERCLA sites
containing low-level radioactive waste, if the waste will be left on site permanently. However,
radioactive wastes at CERCLA sites often fall outside the definition of wastes covered by Part
61, particularly when naturally occurring and accelerator-produced radioactive material
(NARM) is involved.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-23
Requirements at Superfund Mining Sites
10 CFR Parts 30, 40, and 70: Licensing Requirements for Possession and Use of
Byproduct, Source, and Special Nuclear Material
Applicability
in 10 CFR Parts 30, 40, and 70, licensing requirements are described for the possession and
use of byproduct, source, and special nuclear material, respectively. These parts may be
applicable to CERCLA actions at sites licensed under the respective parts. They may be
relevant and appropriate for other, non-licensed sites that contain radioactive contamination.
Highlight D-8:
NRC Requirements at CERCLA Mining Sites: Example Sites
The United Nuclear, NM site is an inactive state-licensed uranium mill facility. Off-site migration of radionuclides
and chemical constituents from uranium milling byproduct materials into the groundwater is a principal threat at the
site. Some of the primary contaminants of concern are radioactive substances including radium-226/228 and gross
alpha. The NRC has adopted the standards at 40 CFR Part 192 Subpart D, which set groundwater limits for
combined radium-226 and radium-228 and for gross alpha (excluding radon and uranium), into its regulations at 10
CFR Part 40, Appendix A. Because the site is licensed by the NRC, 10 CFR Part 40 requirements are applicable.
The Homestake Mining Company site in New Mexico, which consists of a uranium processing mill and two tailings
embankments, was found to have elevated radon levels. In New Mexico, the NRC has jurisdiction over urariium
mills, and the NRC issued the Homestake Mining Company a radioactive materials license. Two NRC regulations
were identified as ARARs for this site: 10 CFR Part 20 and 10 CFR Part 40 Appendix A. The 10 CFR Part 20
requirements, which are standards for protection against radiation, are considered relevant and appropriate. The
10 CFR Part 40 Appendix A requirements are applicable for this site, because they apply to mill closure and address
the cleanup and removal of Ra-226 in soil. (Note: At this site, no action was taken, because the radon was
determined to be a result of natural soil concentrations.)
Highlight D-9:
DOE Requirements at CERCLA Mining Sites: Example Site
The Monticello Vicinity Properties site in Utah, which contains thorium, radium, and radon contamination in uranium.
mill tailings, is a designated site under DOE's Surplus Facilities Management Program. It is also listed on the NPL
and therefore must comply with CERCLA requirements. Because the properties are a DOE site, remedial actions
must also comply with the DOE internal orders on radioactive wastes. DOE hot spot criteria from these internal
orders were found to be applicable for actions at this site.
D.3.4 DOE Program. As explained above, DOE's requirements for radioactive wastes are
contained in a series of internal orders that apply only to cleanups at DOE facilities. However,
the requirements are potential "To-Be-Considered" information for non-DOE sites. The most
important DOE order is DOE 5400.5 "Radiation Protection of the Public and the Environment,"
which includes standards and requirements to protect the public from risk from radiation,
concentration guides for liquids discharged to surface waters, and guidelines for residual
radioactive material at certain DOE sites. DOE Order 5400.11 establishes similar
requirements for workers.
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D-24 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
DA CLEAN WATER ACT
D.4.1 Regulatory Program. The Clean Water Act (CWA) regulates the discharge of any
pollutant or combination of pollutants to waters of the U.S. from any point source. The
substantive and/or administrative elements of CWA requirements are potential ARARs for
CERCLA mining response (and other) actions that include an action resulting in:
• Direct discharges to surface water or oceans;
• Indirect discharges to a publicly owned treatment works (POTW);
• Storrn water discharges; or
• Discharge of dredged or fill material into the waters of the U.S. (including wet-
lands).
These regulated discharges commonly occur at Superfund mining sites in the form of
channeled runoff, treated wastewater discharge, and storm water runoff. In addition, many
Superfund mining sites have uncontrolled discharges that are the source of much
contamination and contaminant migration. The CWA-based standards also may be
appropriate for discharges that are causing the contamination (e.g., mine drainage).
Various types of ambient and technology-based standards have been promulgated under the
CWA to control discharges of pollutants to waters of the U.S. These include:
• Technology-based Standards. All direct dischargers must meet these standards.
Requirements include, for conventional pollutants, application of the best conven-
tional pollutant control technology (BCT), and for toxic and nonconventional
pollutants, the best available technology economically achievable (BAT). (See
Highlight D-10 for a description of the three categories of pollutants.) Technology-
based standards are determined through the use of effluent limitation guidelines.
There are no effluent guidelines for CERCLA sites. Therefore, technology-based
treatment standards are determined on a site-specific basis using best profession-
al judgment. Effluent discharge limits are then derived from the levels of perfor-
mance of a treatment technology applied to a wastewater discharge.
Highlight D-10:
Categories of CWA Pollutants
The following are descriptions of the regulatory classes of pollutants regulated under the CWA:
• Toxic pollutants. The 126 individual priority toxic pollutants contained in 65 toxic compounds or
classes of compounds (including organic pollutants and metals) adopted by EPA pursuant to the
CWA section 307(a}{1);
• Conventional pollutants. The pollutants classified as biochemical oxygen demanding (BOD), total
suspended solids (TSS), fecal coliform, oil and grease, and pH pursuant to the CWA section
304(a)(4); and
• Nonconventional pollutants. Any pollutant not identified as either conventional, or toxic in
accordance with 40 CFR 122.21 (m)(2). __^_
Federal Water Quality Criteria (FWQC). FWQC are nonenforceable guidance
established by EPA for evaluating toxic effects on human health and aquatic
organisms. FWQC are used or considered by states in setting their water quality
standards (WQS). In addition, they can be used as a baseline indicator of environ-
mental risk at Superfund sites.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-25
• State Water Quality Standards (WQS). Under CWA section 303, states must
develop water quality standards. State WQSs;may be numeric or narrative. They
consist of designated uses (e.g., fishing, swimming, drinking water) for waters and
criteria for pollutants set at levels that are protective of those uses.
D.4.2 Direct Discharge Requirements. Activities at mine sites that may trigger direct
discharge requirements include:
• Discharge of mine water to a stream;
• Discharge of waters to a wetland or from a wetland to a river;
• Channeling site runoff directly to a surface water body via a ditch, culvert, storm
sewer, or other means;
• On-site waste treatment in which wastewater is discharged directly into a surface
water body in the area of contamination or in very close proximity to this area via
pipe, ditch, conduit, or other means of "discrete conveyance;" and
• Off-site waste treatment in which wastes from the site are piped or otherwise
discharged through a point source to an off-site surface water.
On-site direct discharges must meet technology-based standards (for conventional pollutants)
and result in ambient standards that do not exceed state water quality standards or FWQC (for
priority pollutants).7 Off-site direct discharges must meet these substantive requirements as
well as administrative requirements such as obtaining a permit from the state authority,
reporting, and public participation requirements. (See Highlight D-11 for more detail on
administrative requirements associated with NPDES program.)
The substantive requirements of the NPDES program include the federal water quality criteria
and state water quality standards introduced above. State water quality standards are
generally the applicable cleanup standards for surface water and discharges into surface
waters. Because FWQC are not enforceable, EPA has determined in previous guidance that
they are never applicable for CERCLA actions.8 However, these criteria may be relevant and
appropriate for Superfund actions involving direct discharges to surface water. Under
CERCLA section 121, site managers must determine if a FWQC is relevant and appropriate
"under the circumstances of the release or threatened release" based on:
• The state-designated or potential use of the water;
• The environmental media affected; ,
• The purpose of the criteria; and
• The latest available information.
' For CWA permitting purposes, "on-site" means the area! extent of contamination and all suitable areas in very close proximity
to the contamination necessary for implementation of the response action.
* CERCLA Compliance With Other Laws Manual, Part I. Draft, August 8, 1988. OSWER Directive 9234.1-01.
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D-26 Appendix O: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites ,
Highlight D-1'1:
Administrative Requirements of the NPDES Program
Certification. CWA section 401 requires that any applicant for a federal license or permit to conduct
an operation that may result in any discharge to navigable waters shall provide to the licens-
ing/permitting agency a certification from the state that the discharge will comply with applicable
provisions of CWA sections 301, 302, 303, 306, and 307.
Permit Application Requirements. A discharge from a CERCLA site is considered a "new
discharge" for regulatory purposes under the NPDES program. NPDES regulations (40 CFR 122.29)
require that applications for permits for new discharges be made 180 days before discharges actually
begin. The information required in a permit application will be collected during the RI/FS. States with
NPDES authority may have slightly different permit application requirements for new discharges. .The
NPDES regulations require that pollution control equipment must be installed before the new
discharge begins, and compliance must be achieved within the shortest feasible time, not to exceed
90 days. The substantive requirements of a permit must be achieved by CERCLA action even though
CERCLA actions are not subject to permitting requirements.
Reporting Requirements. The NPDES permit program requires dischargers to maintain records
and to report periodically on the amount and nature of pollutants in the wastewaters discharged (40
CFR 122.44 and 122.48). Reports that are typically required include emergency reports (required
in cases of noncompliance that .are serious in nature) and discharge monitoring reports (routine
monitoring reports).
Public Participation. CERCLA site managers should also be aware that NPDES discharge
limitations and requirements developed for a CERCLA site are subject to public participation
requirements in 40 CFR 124.10. including public notice and public comment.
FWQC for protection of human health identify protective levels for two routes of exposure:
(1) ingestion of contaminated drinking water and contaminated fish; and (2) ingestion of
contaminated fish alone. For example, an FWQC reflecting drinking the water could be
relevant and appropriate for waters designated as a public water supply; the criterion that
reflects fish consumption and drinking the water should generally be used as the relevant and
appropriate standard if fishing is also included in the state's designated use. If the state has
designated a water body for recreation, a FWQC reflecting fish.consumption alone may be
relevant and appropriate if fishing is included in that designation. Generally, FWQC are not
relevant and appropriate for other uses, such as industrial or agricultural use, because
exposures assumed when setting FWQC are not likely to occur. FWQC may be relevant and
appropriate for selecting cleanup levels for groundwater, if they are adjusted to reflect only *
exposure from drinking the water.
Although FWQC may often be ARARs, if a state has promulgated a WQS for the pollutants
and water body at the site, the state standard would generally be the ARAR rather than the
FWQC, because the state standards essentially represent a site-specific adaptation of the
federal criteria.
If a promulgated MCL for a pollutant exists (see the Safe Drinking Water Act section of this
appendix) and the water is a designated or potential drinking water supply, the MCL may
supersede the FWQC as the cleanup standard for that pollutant, state drinking water
standards also may be potential ARARs in this situation.
FWQC may also be used as the baseline against which to assess whether site conditions pose
an environmental risk. The criteria for the protection of aquatic life can be compared to the
ambient concentrations of a chemical as one measure of whether it is necessary to take
actions to reduce contaminant levels. These "exceedances" of FWQC, however, may not fully
reflect environmental risks, and should be used only after consultation with environmental risk
experts.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
. Requirements at Superfund Mining Sites
D-27
Antidegradation Policy (40 CFR131 ;12)! - -
State antidegradation requirements vary widely in their scope and drafting. However, as a
general rule, they are anti-pollution requirements (not cleanup requirements) designed to
prevent further degradation of the surface water or groundwater. Antidegradation
requirements typically accomplish their purpose in one of two ways: (1) by prohibiting or
limiting discharges that potentially degrade the surface water or groundwater (typically action-
specific requirements); or (2) by requiring maintenance of the surface-water or groundwater
quality consistent with current uses:.
Under the Clean Water Act, every state is required to classify all of the waters within its
boundaries according to their intended use. As required by EPA regulation, all states have
established surface-water antidegradation regulations. These requirements may be potential
ARARs for CERCLA remediations involving discharges to surface water. Although not
specifically required by EPA, the majority of states have also established some form of
groundwater antidegradation provisions. These states may have enacted specific groundwater
antidegradation statutes, or they may include groundwater protection provisions within general
environmental statutes. These state provisions for groundwater may constitute potential
ARARs for CERCLA remediations that have an impact upon the groundwater (e.g.,
groundwater reinjection or soil flushing).
State antidegradation requirements are often expressed as general goals. These require-
ments may be potential ARARs if they are: (1) directive in nature and intent; and (2)
established through a promulgated statute or regulation that is legally enforceable. At a
Superfund site, antidegradation requirements are generally action-specific requirements that
may apply during the course of and at the completion of the Agency response action. They
apply prospectively, and generally obligate the Agency only to prevent further degradation of
the water during and at completion of the response action (not prior to it). Although anti-
degradation requirements are not cleanup laws, in some limited cases they may, as relevant
and appropriate requirements, be appropriate for establishing a cleanup level for past
contamination.
Administrative Requirements
Certification (CWA section 401)
• Any applicant for a federal license or permit to conduct an operation that may
result in any discharge to navigable waters shall provide to the licensing/permitting
agency a certification from the state that the discharge will comply with applicable
provisions of CWA sections 301, 302, 303, 306, and 307.
Permit Application Requirements (40 CFR 122.21 and 122.29)
A discharge from a CERCLA site is considered a "new discharge" under the NPDES program.
Although CERCLA actions are not subject to the permitting requirements the substantive
requirements of the permit must be achieved as discussed in Highlight D-12.
Applications for permits for new discharges must be made at least 180 days before
discharges actually begin.
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D-28 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
• The information required in a permit application will be collected during the RI/FS.
• Pollution control equipment must be installed before the new discharge begins,
and compliance must be achieved within the shortest feasible time, not to exceed
90 days.
(States with NPDES authority may have slightly different permit application
requirements.)
Highlight D-12:
CWA Direct Discharge Requirements as ARARs: Example Site
At the California Gulch site in Colorado, tunnel discharge has resulted in cadmium, copper, lead, and zinc
contamination in surface water. The selected remedy for the site will include discharge of treated effluent into
surface water of the California Gulch. Aquatic life in both the California Gulch and the Arkansas River are potential
receptors of contamination. The affected waters are designated for "cold water aquatic'life," secondary contact
recreation, and agriculture. Based on evaluation of the existing and potential uses of the waters, the environmental
media affected, the purposes of the criteria, and the latest information available, EPA determined that water quality
criteria for acute and chronic toxicity to freshwater aquatic life are relevant and appropriate. Certain state of
Colorado water quality standards are also ARARs for the discharge of treated effluent. Finally, Colorado's
antidegradalion standard, which requires that existing uses be maintained and that no further water quality
degradation occur that would interfere with or become injurious to existing uses is applicable.
One component of the selected remedy for the California Gulch site involves the construction of an interim treatment
facility on site. Because the facility will be located on site, no permit is required. However, the facility must comply
with appropriate substantive direct discharge requirements.
Reporting Requirements (40 CFR Part 122)
• Dischargers must maintain records and report periodically on the amount and
nature of pollutants in the wastewaters discharged. Generally, Superfund would
meet these requirements through monitoring that is conducted based on the
selected remedy.
Public Participation (40 CFR 124.10)
• NPDES discharge limitations and requirements developed for a CERCLA site are
subject to public participation requirements, including public notice and public
comment.
D.4.3 Indirect Discharge Requirements.
Applicability
Indirect discharge means the discharge of a waste to a publicly owned treatment works
(POTW), which in turn generally discharges the treated wastewater to receiving waters.
Requirements for indirect discharges include pretreatment standards and the use of control
measures such as permits or orders.
Indirect discharges are always considered an off-site activity. Therefore, CERCLA actions
always must comply with both the substantive and administrative requirements for indirect
discharges. Pretreatment standards for indirect discharges will generally be applicable for
CERCLA activities. However, where pretreatment standards specify quantities or
concentrations of pollutants or pollutant properties that may be discharged to a POTW by
users in specific industrial categories, these standards are not applicable, because CERCLA
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-29
Requirements at Superfund Mining Sites
actions do not fit into any of these categories. However, these standards may be relevant and
appropriate if the consideration underlying the standard (e.g., type and concentration of
pollutant, type of industrial process that produced the waste) are sufficiently similar to the
conditions found at the site.
Standards
Pretreatment Standards (CWA section 307(b), 40 CFR Part 403)
• Pollutants introduced into POTWs by a non-domestic source shall not cause pass
through (i.e., a discharge that exits the POTW in concentrations or quantities that
cause a violation of the POTW's NPDES permit) or interference (i.e., a discharge
that inhibits or disrupts a POTW, its treatment processes or operations, or its
sludge processes, thereby causing either a violation of the POTW's NPDES permit
or prevention of sewage sludge use or disposal in compliance with various
statutory provisions and regulations).
• Pollutants may not be introduced to a POTW if they:
Create a fire or explosion hazard in the sewers or treatment works;
Will cause corrosive structural damage to the POTW (pollutants with a pH
lower than 5.0);
Obstruct flow in the sewer system resulting in interference;
Are discharged at a flow rate and/or concentration that will result in
interference;
Increase the temperature of wastewater entering the treatment plant so as to
inhibit biological activity resulting in interference (in no case shall the
temperature of the POTW increase to .above 104°F (40°C));
Include petroleum oil, certain non-biodegradable oils, or products of mineral
oil origin in amounts that cause interference or pass through;
Result in toxic gases, vapors, or fumes within the POTW that may cause
acute worker health and safety problems; or
Are hauled to any location at the POTW except designated discharge points.
• Some POTWs must develop and enforce specific effluent limitations to implement
the prohibitions specified above.
• POTWs may enforce local prohibitions on wastes with objectionable color, noxious
or malodorous liquids, wastes that may voiatize in the POTW, radioactive wastes,
and other types of wastes that are incompatible with POTW operations.
The national pretreatment standards also specify quantities or concentrations of pollutants or
pollutant properties that may be discharged to a POTW by existing or new industrial users in
specific industrial subcategories. These categorical standards are not applicable requirements
because CERCLA cleanup actions do not presently fit within any industrial category for which
such standards exist. However, they may be relevant and appropriate if the considerations
underlying the categorical standard (e.g., type and concentration of pollutant, type of industrial
process that produced the waste) are sufficiently similar to the conditions of the hazardous
substance found at the site.
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D-30 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
POTW Control Mechanisms (CWA section 403.8(f)(1)(iii))
Control mechanisms (e.g., permits or orders) must be used to regulate indirect discharges to
POTWs. POTWs have the authority to limit or reject wastewater discharges and to require
dischargers to comply with control mechanisms such as permits or orders. These permits or
orders contain applicable pretreatment standards including local discharge prohibitions and
numerical discharge limits. In addition to incorporating pretreatment limitations and require-
ments, the control mechanisms may also include: (1) monitoring and reporting requirements to
ensure continued compliance with applicable pretreatment standards; (2) spill prevention
programs to prevent the accidental-discharge of pollutants to POTWs (e.g., spill notification
requirements); and (3) other requirements.
D.4.4 Storm Water Requirements. EPA promulgated the first of several regulations that
establishes a permitting process and discharge regulations for storm water on November 16,
1990. Storm water is defined under these regulations as "storm water runoff, snow melt
runoff, and surface runoff and drainage" (40 CFR 122.26(b)(13)). Under these regulations, the
following discharges are subject to storm water requirements:
• Discharges associated with an industrial activity (further outlined at 40 CFR
122.26(b)(14)).
• Discharges from municipal separate storm sewer systems serving more than
100,000 people.
• Case-by-case designations: permit may'be required if the Director determines that
a discharge contributes to a violation of a water quality standard or is a significant
contributor of pollutants to the waters of the U.S.
Under storm water requirements, dischargers must obtain a permit, under which the amount of
pollutants in storm water discharged into surface waters (or conveyances leading to surface
waters) will be regulated. "Storm water discharge[s] associated with industrial activity" (which
are the regulated storm water discharges most likely to be found at a Superfund mining site)
are discharges from any conveyance used for collecting and conveying storm water and
directly related to manufacturing, processing or raw materials storage areas at an industrial
plant. Permits for these discharges must cover areas:
• Directly related to an industrial process, (e.g., industrial plant yards, immediate
access roads and rail lines, material handling sites, refuse sites, sites used for the
application or disposal of process wastewaters, sites used for the storage and
maintenance of material handling equipment, known sites that are presently or
have been used in the past for residual treatment, storage, or disposal, shipping
and receiving areas, manufacturing buildings, storage areas (including tank farms)
for raw materials and intermediate and finished products).
• Where industrial activity has taken place in the past and significant materials
remain and are exposed to storm water.
• That are facilities related to the mineral industry, including certain active and
inactive mining operations.
• That are RCRA Subtitle C facilities that contribute to storm water discharges.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-31
Requirements at Superfund Mining Sites
A permit application is required for mining activities when discharges of storm water runoff
from mining operations come into contact with any overburden, raw material, intermediate
product, finished product, byproduct, of wlste product Ic-clted on the site. Determination of
whether a mining operation's runoff is contaminated will be made in the context of the permit
issuance proceedings. If the determination is made that the runoff is not contaminated, a
permit is not required. Mining areas that are no longer being mined but that have an
identifiable owner/operator are included.
NPDES permits are not required for discharges of storm water runoff from mining operations
that are composed entirely of flows:from conveyances used for collecting and conveying
precipitation runoff that are not contaminated by contact with any overburden, raw material,
intermediate product, finished product, byproduct, or waste product located on the site of such
operations.
Permit applications must be submitted within one year from the date of publication of this
notice (i.e., November 16, 1991) but this date was extended for several types of activities in
subsequent rulemakings. Facilities proposing a new discharge of storm water associated with
industrial activity shall submit an application 180 days before that facility commences the
industrial activity. Permits will require compliance with sections 301 and 402 of the CWA
(requiring control of the discharge of pollutants that utilize the Best Available Technology
(BAT) and the Best Conventional Pollutant Control Technology (BCT) and where necessary,
water quality-based controls). General permits will require development of storm water control
plans and practices (the conditions for these permits have not yet been finalized). In addition,
permittees will have to meet effluent guidelines. EPA has established effluent guideline
limitations for storm water discharges for nine subcategories of industrial dischargers,
including cement manufacturing, feedlots, fertilizer manufacturing, petroleum refining,
phosphate manufacturing, steam electric, coal mining, ore mining and dressing, and asphalt.
In an April 2, 1992 rule, EPA published general permit requirements for reporting for
discharges associated with an industrial activity and minimum monitoring requirements. This
rule also presented a strategy for issuing stormwater permits. Among the monitoring
requirements for covered activities are the following:
• Monitoring frequency will be set on a case-by-case basis, but no less than at least
once each year.
• Inactive mining operations can have inspections once every three years when
annual inspections are impracticable.
• Monitoring results will be repeated at least once each year.
Storm water requirements will generally not be applicable at Superfund actions, because the
requirements are intended to regulate active industrial activities. However, the requirements
could be relevant and appropriate at mining sites where storm water runoff is contaminated.
D.4.5 Dredge and Fill Requirements. Dredge and fill activities at CERCLA sites may include
dredging of a contaminated lake or river, disposal of contaminated soil or waste in surface
water, capping of the site, construction of berms and levees to contain wastes, stream
channelization, excavation to contain effluent, and dewatering of the site. Specific
requirements, established under the CWA as well as other statutes, regulate the discharge of
dredged or fill material to waters of the U.S.
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D-32 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Dredge-and-fill activities are regulated under the following authorities:
• Section 10 of the Rivers and Harbors Act prohibits the unauthorized obstruction
or alteration of any navigable water of the United States.
• Section 404 of the Clean Water Act regulates the discharge of dredged or fill
material to waters of the United States. It states that no discharge of dredged or
fill material shall be permitted if there is a practicable alternative to the proposed
discharge that would have less adverse impact on the aquatic ecosystem, as long
as the alternative does not have other significant adverse environmental effects.
"Practicable" is defined by the regulations to mean available and capable of being
done after taking into consideration cost, existing technology, and logistics in light
of overall project purposes.
• Section 103 of the Marine Protection Research and Sanctuaries Act regulates
ocean discharges of materials dredged from waters of the United States.
• 40 CFR Part 6, Appendix A contains EPA's regulations for implementing
Executive Order 11990, Protection of Wetlands, and Executive Order 11988,
Floodplain Management (see the section on these Executive Orders in this
appendix), which require federal agencies to avoid, to the extent possible, long-
and short-term adverse impacts associated with he destruction or modification of
wetlands, to avoid direct or indirect support of new construction in wetlands where
there are practicable alternatives, and to minimize potential harm to wetlands when
there are no practicable alternatives. The proposed plan and selected remedial
action should be evaluated in light of these requirements and the alternative
modified, if necessary, to avoid or minimize adverse impacts.
The Army Corps of Engineers evaluates applications for permits for activities regulated under
section 10 of the Rivers and Harbors Act and section 404 of the CWA. Although section 404
permits are not required for dredge and fill activities conducted entirely on site, the Corps'
expertise in assessing the public interest factors for dredge and fill operations can contribute to
the overall quality of the response action.
Section 404 applies to the discharger of dredged and fill materials and addresses the impacts
caused by such discharges. In some CERCLA response actions, the wetland will already be
severely degraded by virtue of prior discharges of waste. Part of the CERCLA remedy may be
to fill in the wetland, with the intention that the fill would serve an environmental benefit.
Where the function of the wetland has already been significantly and irreparably degraded,
mitigation would be oriented towards minimizing further adverse environmental impacts, rather
than attempting to recreate the wetland's original value on site or off site. That is, there would
be no obligation under CWA section 404 for the lead agency to mitigate those impacts that
preceded the remedial fill operation. Although section 404 is not applicable in such cases,
mitigation, including wetland restoration and creation, may be appropriate in some
circumstances to protect the environmental value of the site. Other provisions, such as 40
CFR 6.302, may require such mitigation (see the section on E.O. 11990, Protection of
Wetlands in this appendix for more information on the mitigation of adverse effects on
wetlands).
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-33
Requirements at Superfund Mining Sites
D.4.6 Implementation of CWA Requirements at Superfund Mining Sites. Certain
conditions commonly found at mining sites may complicates attempts to comply with CWA
requirements. Mine sites often have large areas and rnany sources from which large volumes
of waste flow. Because of these conditions, it may be difficult to achieve water quality criteria
or standards. In some cases, it may be necessary to construct an on-site treatment facility.
Existing sediment contamination may lead to continued exceedances even after discharges
comply and/or streams are diverted or channeled. Likewise, storm water runoff from wide-
spread contamination sources may produce contaminant loading. Other sources may also
cause problems and may require multi-program strategy. Site managers should coordinate
activities regulated by the CWA with the appropriate state agency, particularly if the state has
ah authorized NPDES program.
D.5 SAFE DRINKING WATER ACT
D.5.1 Regulatory Program. The Safe Drinking Water Act (SOWA) establishes regulations to
protect human health from contaminants in current and potential sources of drinking water.
SDWA requirements are potential ARARs for CERCLA sites that contain contaminated
drinking water or where remedial actions will involve discharges to drinking water. In addition,
sites where underground injection will be part of the remedial action may be subject to SDWA
requirements.
Requirements from the following EPA programs established under the SDWA are potential
ARARs for CERCLA actions:
• Drinking Water Standards. EPA has developed two sets of drinking water stan-
dards that may be ARARs for CERCLA actions:
Primary drinking water regulations. These standards consist of
contaminant-specific levels known as Maximum Contaminant Levels (MCLs).
They are based on Maximum Contaminant Level Goals (MCLGs), which are
purely health-based goals.
Secondary drinking water regulations. These standards consist of
Secondary MCLs (SMCLs) for specific contaminants or water characteristics
that may affect the aesthetic qualities (e.g., odor, taste) of drinking water.
States may also establish drinking water standards. Where drinking water
standards cannot be attained, provisions exist for application for variances and
exemptions from compliance with primary MCLs.
• Underground Injection Control (UIC) Program. Requirements under this
program regulate the injection of hazardous waste and other wastewaters into
wells.
• Sole-Source Aquifer and Wellhead Protection Programs. These programs are
designed to protect these vital aspects of the nation's groundwater. ,
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D-34 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.5.2 Drinking Water Standards.
Applicability
MCLs set under the primary drinking water regulations will be applicable where certain
contaminants are found in drinking water that is directly provided to 25 or more people or
supplied to 15 or more service connections. If MCLs are applicable, they must be complied
with at the tap. MCLs are relevant and appropriate as cleanup standards where either surface
water or groundwater is or may be used for drinking water. Where multiple contaminants or
multiple pathways of exposure present extraordinary risks, a standard more stringent than an
MCL may be needed (to reflect the additivity of risks). Site managers should make site-
specific determinations in setting a level more stringent than the MCL.9
SMCLs are nonenforceable limits and therefore generally cannot be applicable to CERCLA
actions. However, they may be relevant and appropriate, or, where a state has adopted
SMCLs as additional drinking water standards, they may be applicable.
Primary Drinking Water Regulations (40 CFR Part 141)
MCLs have been promulgated for the following contaminants commonly found at mining sites.
They are:
Contaminant
Arsenic
Barium
Cadmium
Chromium
Flouride
Lead
Mercury
Nitrate (as N)
Selenium
MCL (mg/l)
0.05
1
0.010
0.05
4
0.05
0.002
10
0.01
For MCLs for radionuclides, see the Radioactive Wastes section of this document.
* In the past, EPA's policy was that, in cases involving multiple contaminants or pathways where the risk exceeded 10"*, MCLGs
were to be considered when determining acceptable exposures. This policy was changed, however, by the NCP (55 FR 8750,
March 8.1990). Underthe revised NCP, where an MCLG establishes a contaminant level above zero, that MCLG is a potential
relevant and appropriate requirement, with determinations to be made on a site-specific basis as to the relevance and appropriate-
ness of meeting that level under the circumstances of the release. Where an MCLG is equal to zero level of contaminants (as for
carcinogens), that MCLG is not "appropriate" for the cleanup of ground or surface water at CERCLA sites. In such cases, the
corresponding MCL will be considered as a potential relevant and appropriate requirement, and attained where determined to be
relevant and appropriate under the circumstances of the release. In cases involving multiple contaminants or pathways where
attainment of chemical-specific ARARs will result in cumulative risk in excess of 10'". criteria in NCP §300.430(e)(2)(l)(A) (55 FR
8848) may also be considered when determining the cleanup level to be attained.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-35
Highlight D-13:
SDWA as ARARs: Example Site
California Gulch, CO
Surface water and groundwater at this site, which are contaminated with cadmium, copper, lead, and zinc, do not
meet the SDWA definition of public water supply, but they connect in the lower California Gulch shallow alluvial
system, which is an existing or potential drinking water source. Therefore, SDWA drinking water standards are
relevant and appropriate for this site.
EPA anticipates that the selected remedy will not achieve a degree of cleanup in lower California Gulch surface
water that attains primary and secondary IVlCLs. Numerous sources contribute to metals loadings in lower California
Gulch, including mine wastes, tailings, and slag in the California Gulch drainage basin and tributaries. The tunnel
plugging and interim treatment facility components of the selected remedy will achieve substantial reductions in
metals loadings. In future operable units, it will be necessary to develop and evaluate additional source control
measures to attain or exceed drinking water ARARs for specific metals.
Secondary Drinking Water Regulations (40 CFR 143)
SMCLs have been promulgated for the following contaminants commonly found at mining
sites. They are:
Contaminant
Aluminum
Chloride
Color
Copper
Corrosivity
Fluoride
Foaming Agents
Iron
Manganese
Odor
pH
Silver
Sulfate
Total dissolved solids
Zinc
Level
0.05 to 0.2 mg/1
250 mg/1
15 color units
1.0 mg/1
Non-corrosive
2.0 mg/1
0.5 mg/1
0.3 mg/1
0.05 mg/1
3 threshold odor #
6.5-8.5
0.1 mg/1
250 mg/1
500 mg/1
5 mg/1
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D-36 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.5.3 Underground Injection Control Program (40 CFR Part 144).
Applicability
In 40 CFR Part 144, five classifications of underground injection wells are established:
• Class I: wells that inject RCRA hazardous or other industrial or municipal waste
beneath the lowermost formation containing, within 1/4-mile of the well bore, an
underground drinking water source. An underground source of drinking water is
defined as any aquifer or its portion that supplies a public water system or contains
fewer than 10,000 mg/l total dissolved solids.
• Class II: injection wells associated with oil and natural gas production, recovery,
and storage.
• Class III: wells that inject fluids for use in extraction of minerals.
• Class IV: wells used to inject RCRA hazardous waste into or above a formation
that within 1/4-mile of the well, contains an underground drinking source.
• Class V: wells not considered to be Class I, II, 111, or IV.
Requirements for Class I, IV, and V wells are most likely to be ARARs for CERCLA actions
when wastes are disposed of into one of these units. The injection of wastes into on-site wells
must meet the substantive requirements of this part; injections into off-site wells must meet
both substantive and administrative requirements.
Certain DIG program standards require compliance with the LDRs before injection can occur.
Mining wastes that are excluded from Subtitle C regulation by the Bevill amendment (see the
RCRA section of this appendix) need not comply with these requirements. Mineral processing
wastes that have been removed from the Bevill exclusion are also not required to meet the
LDRs before injection, at this time. However, once the Agency has set LDR treatment
standards for those wastes now subject to Subtitle C, compliance with the LDRs will be
required.
Substantive Requirements
• No owner or operator may construct, operate, or maintain an injection well in a
manner that results in the contamination of an underground source of drinking
water at levels that violate MCLs or otherwise adversely affect the health of
persons.
• Under the RCRA land disposal restrictions, before RCRA hazardous waste can be
disposed of in a Class I well or contaminated groundwater can be reinjected into a
Class IV well, the wastes or the groundwater must attain .any promulgated
treatment levels for each constituent disposed in the injection well, or obtain a
variance.
• Class I wells must obtain a RCRA permit-by-rule as a condition for injecting
hazardous waste. The owner or operator must comply with RCRA corrective
action for releases from solid waste management units (40 CFR 264.101).
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-37
Requirements at Superfund Mining Sites
• Owners and operators of underground injection wells must prepare and submit a
plugging and abandonment p\ar\.
• Owners and operators of ClaSs I wells are subject to the following additional
requirements:
Construction requirements; '
Operating requirements;
Monitoring requirements.
Administrative Requirements
Off-site CERCLA actions must comply with the following administrative requirements of
the UIC Program:
• Application Requirements. All existing and new underground injection wells
must apply for a permit unless an existing well is authorized by rule for the life of
the well;
• Inventory and Other Information Requirements. Existing underground injection
wells that are authorized by rule are required to submit inventory information to
EPA or an approved state. Other information may be required to determine
whether injection will endanger an underground source of drinking water; and
• Reporting Requirements. Owners and operators of Class I wells are required to
maintain records and report quarterly on the characteristics of injection fluids and
groundwater monitoring wells and various operating parameters (e.g., pressure,
flow rate, etc.).
D.5.4 Sole-Source Aquifer Program. EPA may designate aquifers that are the sole or
principal drinking water source for an area and which, if contaminated, would present a signifi-
cant hazard to human health, as "sole source aquifers." Federal financial assistance may not
be committed for any project that may contaminate a sole source aquifer so as to create a'
significant public health hazard. In general, CERCLA activities will not increase preexisting
contamination of sole source aquifers. Therefore, it is unlikely that CERCLA actions would be
subject to restrictions on federal financial assistance. However, site managers should review
potential problems associated with sole source aquifers as part of the RI/FS.
D.5.5 Wellhead Protection Program. States must develop and implement programs to
protect wells and recharge areas that supply public drinking water systems from contaminants
that flow into the well from the surface and sub-surface. Site managers should identify ARARs
under these state wellhead protection programs.
D.5.6 Implementation of the SDWA at Superfund Mining Sites. Certain conditions
commonly found at mining sites may complicate attempts to comply with drinking, water stan-
dards. Mine sites often have large areas and many sources from which large volumes of
waste flow. Because of these conditions, it may be difficult to achieve drinking water
standards. In these circumstances, close coordination with appropriate regulatory offices is
necessary to devise an acceptable strategy. In some cases, an ARAR waiver may be required
if it is not practicable to meet MCLs. Other approaches to consider may include well head .
treatment, alternate water supplies, and institutional controls.
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D-38 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.6 CLEAN AIR ACT
The Clean Air Act (CAA) places controls on stationary and mobile sources of emissions into
the air. CAA requirements, including those promulgated since the passage of the 1990 Clean
Air Act Amendments, are potential ARARs for emissions of gas or particulate matter (e.g.,
dust) from uncontrolled CERCLA hazardous waste sites both that may occur naturally (i.e.,
without disturbance during remediation) and those that are a result of response activities.
Types of activities likely to result in air emissions problems at mining sites include:
• Slowdown from wastes-, in piles, ponds, or other locations;
• Soil or waste excavation and movement; and
• Activities involving construction and operation of waste management units.
Other types of remedial activities that could result in air emissions are:
• Air stripping (used to volatilize contamination both in groundwater and in soil);
• Thermal destruction (e.g., incineration), which may produce emissions through
volatilization of organic contaminants and through volatilization or suspension of
particulate matter into the stack gases;
• Handling of contaminated soil, which can result in volatilization of organic contam-
inants and wind entrainment of particulates;
• Gaseous waste treatment (e.g., flaring used when capping and venting a site,
usually abandoned or inactive landfills;
• Biodegradation, especially when aeration of liquids is involved; and
• Demolition projects, which may cause emission of contaminants to the air.
Under the Clean Air Act, EPA has established three types of standards: National Ambient Air
Quality Standards (NAAQS), National Emission Standards for Hazardous Air Pollutants
(NESHAPs), and New Source Performance Standards (NSPS). These standards are
chemical- and/or source-specific. In deciding which standards are applicable or relevant and
appropriate for mining sites, site managers should determine:
• If a pollutant regulated by the standards is or will be emitted at the site; and
• If the pollutant is or will be emitted from one of the sources specified by the
standards.
D.6.1 National Ambient Air Quality Standards for Criteria Pollutants (40 CFR Part 50).
Applicability
These standards (listed in Highlight D-14) are national limitations on ambient concentrations of
carbon monoxide, lead, nitrogen dioxide, particulate matter (PM10), ozone, and sulfur oxides.
Although they are not source-specific emissions limitations, they apply only to major sources.
The definition of major source depends on whether the source is located in an attainment or
non-attainment area (designated in 40 CFR Part 81). In general, emissions from CERCLA
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-39
activities do not qualify as major. However, even if a site is not a major source, NAAQS may
be relevant and appropriate. .
Because CERCLA mining sites often contain large volumes of waste, these sites may, when
the aggregate of all source emissions at the site is considered, qualify as a major source. A
major source is:
• For an attainment area: a site that emits 250 tons or more per year of any
regulated pollutant, or a.site that contains certain specific types of facilities, such
as an incinerator or chemical processing plant that emits 100 tons or more per
year.
• For a non-attainment area: a site that emits 100 tons or more per year of the
pollutant for which the area is designated non-attainment.
Each state has the primary responsibility for assuring that NAAQS are attained and
maintained. Each state must submit a State Implementation Plan (SIP) to EPA for approval.
Once approved, the SIP becomes federally enforceable. Thus, state requirements can
become federal requirements through the SIP approval process. Elements of approved SIPs,
which can include more stringent state requirements, are potential ARARs for CERCLA sites.
Pre-construction Review
• New and modified stationary sources of air emissions must undergo a pre-
construction review to determine whether the construction or modification of any
stationary source will interfere with the attainment or maintenance of NAAQS or
will fail to meet other new source review requirements, which would result in a
denial of a permit to construct.
Prevention of Significant Deterioration (PSD) Requirements
PSD requirements for attainment areas apply to new major stationary sources and major
modifications in areas designated as being in attainment of the NAAQS for criteria pollutants.
They also apply in areas where no data exist and the area is defined as unclassified. Part C of
the CAA requires SIPs to contain "adequate provisions" for the prevention of significant
deterioration of air quality in an attainment area.
Under the PSD program, a CERCLA site would not be considered a major source unless it
was expected to emit 250 tons or more per year of any regulated pollutant (or unless the site
contains certain specific types of facilities, such as an incinerator or chemical processing plant,
for which the threshold is 100 tons per year.
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D-40 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites _____
Highlight D-14:
National Ambient Air Quality Standards (NAAQS)
Criteria
Pollutant
Primary
Standards
Averaging
Time
Secondary
Standards
Carbon Monoxide
Lead
Nitrogen dioxide
Particulate Matter
(PM,0)
Ozone
Sulfur oxides
9 ppm
35ppm
1.5 ug/m3 "• •
0.053 ppm
50 pg/m3
150 |Jg/m3
0.12 ppm
0.03 ppm
0.14 ppm
8-hour8
1-hour3
Quarterly average
Annual (arithmetic
mean)
Annual (arithmetic
mean6
24-hour2
1-hour"
Annual (arithmetic
mean)
24-hour3
3-hour3
None
Same as primary
Same as primary
Same as primary
Same as primary
0.5 ppm
* Not to be exceeded more than once per year.
b The standard is attained where the expected annual arithmetic mean concentration, as determined in accordance with
Appendix K (52 FR 24667, July 1. 1987), is less than or equal to 5Q M9/m3.
e The standard is attained when the expected number of days per calendar year with a 24-hour average concentration
above 150 pg/m3 is equal to or less than 1.
* The standard is attained when the expected number of days per calendar year with maximum hourly average
concentrations above 0.12 ppm is equal to or less than 1.
Where there is an existing major stationary source, a Superfund site could trigger a
modification to that source. A major modification is generally a physical or operational change
in a major stationary source that would result in a significant net emissions increase for any
regulated pollutant. Specific numerical cutoffs that define significant increases are identified in
40 CFR 52.21 (b)(23). A Superfund site would be considered a modification to an existing
source only where:
• The site is physically connected to or immediately adjacent to the existing source;
• A responsible party (RP) is conducting the cleanup;
• The RP is also the owner or operator of the existing source; and
• The CERCLA site is somehow associated with the operations of the existing
source.
Fugitive emissions are not to be considered in determining whether a source would be
a major source, except when such emissions come from source categories listed in 40
CFR 52.21 (b)(1)(iii) (see Highlight D-15). Fugitive emissions would not be counted in with
CERCLA site emissions unless the site is considered a modification to one of the listed source
categories. However, operations resulting in emissions are not considered fugitive and would
be subject to the NAAQS standards.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-41
' Requirements at Superfund Mining Sites
D.6.2 National Emissions Standards for Hazardous Air Pollutants (NESHAPs) (40 CFR
Part 61).
Applicability
NESHAPs are emission standards for certain hazardous air pollutants for which no NAAQS
exists. They are promulgated for emissions from specific sources. NESHAPs are generally
not applicable to CERCLA remedial actions because Superfund sites do not usually contain
any of the specific source categories regulated. Furthermore, they are generally not relevant
and appropriate, because the standards of control are intended for the specific type of source
regulated and not all sources of that pollutant.
In general, only NESHAPs for radionuclides and asbestos are likely to be ARARs for
CERCLA sites. NESHAPs for radionuclides, which are discussed in detail in the radioactive
wastes section of this appendix, regulate radionuclide air emissions from active underground
uranium mines, certain DOE facilities, certain NRC-licensed facilities and non-DOE federal
. facilities, and active NRC-licensed uranium mill tailings sites. Most of these NESHAPs will be
only relevant and appropriate for CERCLA mining site actions.
Asbestos NESHAPs govern inactive waste disposal sites for asbestos mills and manufacturing
and fabricating operations, active waste disposal sites, and disposal of asbestos-containing
waste from demolition and renovation operations. Although these requirements are not
applicable to CERCLA sites, they may be relevant and appropriate when they are sufficiently
similar to the site situation and appropriate to the circumstances of the release.
Under the authority of the 1990 amendments to the Clean Air Act, additional NESHAPs will be.
promulgated for certain sources not currently regulated. Several of these NESHAPs, when
promulgated, may be relevant and appropriate for activities at mining sites. The sources
added by the amendments include primary copper smelters, primary lead smelters, zinc
smelting, and other facilities that process nonferrous metals. In addition, under the CAA
amendments, emissions of greater than 10 tons per year of a pollutant will be subject to
NESHAPs. Such quantities could be generated by response activities such as remining at a
Superfund mining site.
Standards
Asbestos NESHAPS (40 CFR Part 61 Subpart M).
• 40 CFR 61.145: Standard for Demolition and Renovation: Procedures for
Asbestos Emission Control
This section sets requirements for removing friable asbestos during building
demolition, including wetting, exhaust systems, and removal procedures.
• 40 CFR 61.150: Standard for Waste Disposal for Manufacturing, Fabricating,
Demolition, Renovation, and Spraying Operations
Owners/operators must deposit all asbestos-containing waste material at
waste disposal sites in accordance with 40 CFR 61.154; and
Discharge no visible emissions to the outside air during the collection,
processing (including incineration), packaging, or transporting of any
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D-42 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
asbestos-containing waste material generated by the source, or use one of
the emission control and waste treatment methods specified in this section.
Highlight D-15:
Source Categories Listed in 40 CFR 52.21 (b)(1)(iii)
Coal cleaning plants (with thermal dryers)
Kraft pulp mills
Portland cement plants :.
Primary zinc smelters
Iron and steel mills
Primary aluminum ore reduction plants
Primary copper smelters
Municipal incinerators capable of charging
more than 250 tons of refuse per day
Hydrofluoric, sulfuric, or nitric acid plants
Petroleum refineries
Lime plants
Phosphate rock processing plants
Coke oven batteries
Sulfur recovery plants
Carbon black plants (furnace process)
Primary lead smelters
Fuel conversion plants
Sintering plants
Chemical processing plants
Secondary metal production plants
Fossil-fuel boilers (or combination thereof)
totaling more than 250 million British thermal
units per hour heat input
Petroleum storage and transfer units with a
total storage capacity exceeding 300,000 bar-
rels
Taconite ore processing plants
Glass fiber processing plants
Charcoal production plants
Fossil fuel-fired steam electric plants of more
than 250 million British thermal units per hour
heat input
Any other stationary source category which, as
of August 7, 1980, was regulated under section
111 or 112 of the Clean Air Act.
40 CFR 61.151: Standard for Inactive Waste Disposal Sites for Asbestos Mills and
Manufacturing and Fabricating Operations
Owners/operators of inactive waste disposal sites for asbestos mills and
manufacturing and fabricating operations must comply with one of the
following:
Discharge no visible emissions to the outside air from an inactive
waste disposal site subject to these requirements;
Cover the asbestos-containing waste material with at least 15 cm (6
inches) of compacted nonasbestos-containing material, and grow and
maintain a cover of vegetation on the area adequate to prevent
exposure of the asbestos-containing material, or in desert areas where
vegetation would be difficult to maintain, place at least 8 additional cm
(3 inches) of well-graded, nonasbestos crushed rock on top of the final
cover instead of vegetation and maintain it to prevent emissions;
Cover the asbestos-containing waste material with at least 60 cm (2
feet) of compacted nonasbestos-containing material, and maintain it to
prevent exposure of the asbestos-containing waste; or
For inactive waste disposal sites for asbestos tailings, apply a resinous
or petroleum-based dust suppression agent that effectively binds dust
to control surface air emissions, using the agent as recommended by
its manufacturer. (Obtain prior written approval of the Administrator to
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-43
Requirements at Superfund Mining Sites
use other equally effective dust suppression agents, excluding any
used, spent, or other waste oil).
Unless a natural barrier adequately deters access by the general public,
install and maintain warning signs and fencing (as directed by 40 CFR
61.151(b)(1) and (2)) or comply with the standards listed above.
With EPA approval, an owner/operator may use an alternative control
method.
Notify the Administrator in writing at least 45 days prior to excavating or
otherwise disturbing any asbestos-containing waste material that has been
deposited at a waste disposal site under this section.
Within 60 days of a site becoming inactive, record a notation on the deed to
the facility property and on any other instrument that would normally be
examined during a title search.
40 CFR 61.154: Standard for Active Waste Disposal Sites
Either there must be no visible emissions to the outside air from any active
waste disposal site where asbestos-containing waste material has been
deposited; or
At the end of each operating day or at least once every 24-hour period while
the site is in continuous operation, the asbestos-containing waste material
that has been deposited during the operating day or previous 24-hour period
should be covered with at least 15 cm (6 inches) of compacted nonasbestos-
containing material or a resinous or petroleum-based dust suppression
agent; or
•i
An alternative control method for emissions is used, with prior EPA approval.
Unless a natural barrier adequately deters access by the general public,
either warning signs and fencing must be installed and maintained or at least
15 cm (6 inches) of compacted nonasbestos-containing material must cover
the asbestos-containing waste material.
Owners or operators of active waste disposal sites must maintain waste
shipment records as specified, send a copy of the signed waste shipment
record to the waste generator, correct discrepancies to the records as
specified, and keep copies of all the records and reports for at least 2 years,
to be made available to the Administrator for inspection upon request.
Upon closure of the site, owners or operators must comply with provisions for
inactive waste disposal sites and submit records of asbestos quantities and
locations to the Administrator.
Owners or operators must notify the Administrator in writing at least 45 days
prior to excavating any asbestos-containing waste material that has been
deposited and covered at a waste disposal site.
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D-44 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Under RCRA, EPA is also regulating air emissions of some organics from process vents and
surface impoundments and tanks in three phases. Phase I, which was promulgated on June
21,1990 (55 FR 25454), limits organic emissions from (1) process vents associated with
distillation, fractionation, thin-film evaporation, solvent extraction, and air or steam stripping
operations that manage hazardous wastes with 10 ppm by weight or greater total organics
concentration, and (2) leaks from equipment that contains or contacts hazardous waste
streams with 10 percent by weight or greater total organics. Phase II, which was proposed
July 22, 1992 (56 FR 33490), consists of air standards for organic air emissions from other
sources not covered or not adequately controlled by existing standards, specifically from
surface impoundments, tanks, containers, and miscellaneous units. Under Phase III, EPA will
assess the residual risk from Phases I and II and will, if necessary, develop further regulations
or guidance to address the effects of organic air emissions.
D.6.3 New Source Performance Standards (NSPS). These standards cover categories of
stationary sources that emit particular pollutants. The purpose of these standards is to ensure
that new stationary sources are designed, built, equipped, operated, and maintained to reduce
emissions to a minimum. The standards affect all new stationary sources, regardless of
whether they are located in an attainment or non-attainment area. Because they are source-
specific, the standards are generally not applicable to Superfund remedial actions. An NSPS
may be applicable if the facility at the Superfund site is a new source subject to an NSPS (e.g.,
an incinerator). An NSPS may be relevant and appropriate if the pollutant emitted and the
technology employed during the remedial action are sufficiently similar to the pollutant and
source category regulated by an NSPS. (As these standards are source-specific, they are
located at various points in the regulations, dependent upon the sources. For example,
NSPS's addressing coal mining, mineral mining and processing, and ore mining and dressing
appear at 40 CFR Part 434, 40 CFR Part 436, and 40 CFR Part 440 respectively).
D.6.4 State Programs. As discussed above, states must adopt a plan to implement,
maintain, administer, and enforce NAAQS. These State Implementation Plans (SIPs) must be
approved by EPA. States also may be authorized to enforce NSPS and NESHAPs. States
have the authority to adopt emissions standards and limitations and control strategies more
stringent than federal standards. State standards are potential ARARs for Superfund sites, as
are Regional or local air program requirements that are a part of a SIP.
In addition, many states have adopted programs to regulate "toxic air pollutants."
Requirements under these programs are likely to be the most significant ARARs for Superfund
activities. These programs differ from state to state in terms of the pollutants and sources
regulated and the safe levels adopted. Site managers should determine if the state in which
the CERCLA site is located has adopted such a program.
A typical state air toxics program will require a source to do the following:
• Identify pollutants of concern by comparing anticipated emissions with the state air
toxics list;
• Estimate emissions of toxic air pollutants using procedures by the state;
• Estimate off-site concentrations, normally by air quality modeling procedures
approved by EPA or the state;
• Compare off-site concentrations to permissible state levels; and
• Require additional controls (beyond what would otherwise be required) if a new
source is likely to exceed the state limits.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-45
Requirements at Superfund Mining Sites
D.6.5 Implementation of CAA Requirements. Where NAAQS are applicable, certain
pollution controls may be required. At CERCLA sites, these may include vapor recovery on air
strippers, controls on emissions of particuiates from incinerators, and controls on sources of
fugitive particulate emissions. Construction and demolition sites are areas of Superfund sites
that are commonly regulated by Clean Air Act requirements.
Highlight D-16:
CAA Requirements as ARARs: Example Site
Anaconda SmelteriMill Creek, MT
Arsenic, cadmium, and lead contamination in several media in Mill Creek, Montana posed an imminent and
substantial danger to human health. The selected remedy for the first operable unit called for relocation of residents
and temporary stabilization of the area, including demolition activities. It was determined that remedial actions were
subject to NAAQS for total suspended particuiates and lead (40 CFR Part 50) and to the Montana Air Quality
Bureau's requirements for particulate matter and construction/demolition sites. Under these requirements, all
buildings had to be wetted with water inside and outside prior to demolition. A dust-suppressing mist had to be
applied at demolition to control airborne particles. In addition, all haul roads and demolition debris had to be watered
to prevent excessive dust. ,
D.7 SURFACE MINING CONTROL AND RECLAMATION ACT
D.7.1 Scope. The Surface Mining Control and Reclamation Act of 1977 (SMCRA) governs
activities associated with coal exploration and mining. Because the standards promulgated
under SMCRA are intended for active coal mines, they will not be applicable to actions at
Superfund mining sites. However, the standards found in 30 CFR Parts 816 and 817, which
govern surface mining activities and underground mining activities, respectively, may be
relevant and appropriate at inactive CERCLA mining sites where activities similar to SMCRA-
reguiated activities occur. This is because SMCRA regulations often address circumstances
that are similar and establish performance objectives that are consistent with the objectives of
a CERCLA investigation.
D.7.2 Implementation.
Under SMCRA, states may be authorized to implement their own programs for controlling coal
mining operations. Regulations passed by an authorized state may be more stringent than
federal requirements. States also have the authority to conduct reclamation programs for
abandoned coal mines, which may be financed using the Abandoned Mine Land Reclamation
Fund (AMLRF), a Fund established by SMCRA. In states where more stringent'standards are
promulgated, these standards (and not the federal requirements) will be ARARs.
Although EPA, under CERCLA, and the Office of Surface Mining Reclamation and
Enforcement (OSMRE) of the Department of the Interior, under SMCRA, both have authority to
clean up abandoned coal mine sites, it has been EPA's policy until this time not to assert its
authority and list coal mine sites on the NPL. EPA's position has been that because the
AMLRF was designed specifically to address reclamation and restoration of land and water
resources adversely affected by past coal mining activities, it is a more efficient use of
resources to allow this Fund to address abandoned coal sites than to clean up these sites
under Superfund. Therefore, coal mining sites will seldom, if ever, be addressed by CERCLA
cleanup actions, and the SMCRA requirements will not be applicable.
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0-46 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Like Superfund requirements, SMCRA performance standards are often established based on
the environmental provisions of other laws. For example, regulations may require compliance
with established numerical standards, such as applicable water quality standards. In other
cases, the standards may be technology-based or may simply require that activities minimize
adverse effects.
SMCRA standards may be relevant and appropriate for CERCLA actions at mining sites if
remedial activities include those covered by these standards. SMCRA will generally be
considered ARARs for activities that are not regulated under other laws. For example, none of
the units regulated under SMCRA is regulated under other environmental laws, nor is
revegetation regulated. In some cases, however, CERCLA requirements for achieving a
protective remedy may be more stringent than SMCRA standards. For example, revegetation
needs at a Superfund mining site may exceed the SMCRA performance standard for
revegetation. In such instances, site managers must ensure that the remedy for the site is
protective of human health and the environment, even after standards determined to be
ARARs are met. A discussion of when each SMCRA requirement in 30 CFR Part 816 may be
relevant and appropriate is included in the table below. (The standards of 30 CFR Part 817,
which cover underground mines, are similar to those in Part 816.)
Although the above table lists only the SMCRA requirements of 30 CFR Part 816, standards
found in Part 817, which govern underground mining activities at coal mines, should also be
considered at Superfund mining sites. In most cases, they will not be ARARs, but they may
offer standards for activities not regulated elsewhere, such as for tunnel plugging. The
standards in Part 817 regulate many of the same activities as Part 816. Additional regulated
activities include sealing of underground openings, use of explosives, and disposal of excess
spoil and coal mine waste.
Highlight D-17:
SMCRA Requirements as ARARs: 2 Example Sites
At the Cherokee Countysite in Kansas, the selected remedial action includes the removal, consolidation, and on-site
placement of surface mine wastes in mine pits, shafts, and subsidences. It also includes diversion and
channelization of surface streams with recontouring and vegetation of land surfaces. The site manager determined
that the SMCRA standards for backfilling and grading, revegetation, postmining land use, and rehabilitation of
sedimentation ponds, diversions, impoundments, and treatment facilities are relevant and appropriate for the site.
At the California Gulch site in Colorado, the selected remedial action includes tunnel plugging and water control
measures. Although EPA and the state identified no ARARs related to tunnel plugging, they considered 30 CFR
Part 817 requirements as guidance to ensure that the tunnel plugging activities were protective. They also
considered 30 CFR Part 817 for guidance to see that activities associated with water control measures are
protective.
D.8 FASH AND WILDLIFE COORDINATION ACT
D.8.1 Prerequisites for Applicability. The Fish and Wildlife Coordination Act is designed to
protect fish and wildlife when federal actions result in the control or structural modification of a
natural stream or body of water. If remedial actions at a CERCLA site will include control or
structural modification of a natural stream or body of water, site managers should consider the
Fish and Wildlife Coordination Act as a potential ARAR.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-47
Fish and Wildlife Coordination Act requirements will generally be applicable to remedial actions
that include:
• Construction of dams, levees, impoundments;
• Stream relocation;
• Water diversion structures; or
• Discharges of pollutants into a body of water or wetlands.
D.8.2 Standards.
• Federal agencies must take into consideration the effect that water-related projects
would have on fish and wildlife and take action to prevent loss or damage to these
resources.
• Agencies must consult with the Fish and Wildlife Service or the National Marine
Fisheries Service as well as the state Wildlife Resources Agency if alteration
occurs as a result of off site actions. Consultation is recommended for on site
actions involving alteration.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-48
Circumstances Under Which Some SMCRA Standards May Be
Relevant and Appropriate at CERCLA Mining Sites
SMCRA Requirement That May
Be Relevant and Appropriate
Summary of SMCRA Requirement
Discussion of When Requirement is Potentially
Relevant and Appropriate for CERCLA
Casing and Sealing of Drilled
Holes (816.15)
Exposed underground openings no longer needed for monitoring or
as water wells, will be capped, sealed, and backfilled.
Permanent closure methods will be designed to prevent access to
mine workings and to keep acid and other toxic drainage from
entering ground/surface waters.
Probably not relevant and appropriate to CERCLA
unless attaining remedial action objectives requires
sealing of drilled holes or other mine openings.
May be relevant and appropriate to CERCLA if
containment of mine drainage is required to meet
remedial action objectives. These requirements
should be considered especially at sites where Acid
Mine Drainage is a source of contamination. They
may be appropriate, for example, if there is a
release or threat of a release of acid that could
mobilize a related release of acid-soluble metals
that could disrupt the hydrologic balance.
Diversions (816.43)
Diversions shall be designed to minimize adverse impacts to
hydrologic balance within permit area.
Diversions shall not be used to divert water into underground mines
without approval of regulatory authority.
Diversions shall:
• be stable;
• provide protection against flooding;
• prevent outside sediment from entering into streamflow; and
• comply with all applicable. local, State, and Federal
regulations.
Temporary diversions shall be replaced with permanent diversions.
Additional requirements may be required of diversions by a
regulatory authority.
When diversions of surface water are used to meet
remedial action objectives, the performance stan-
dards may be relevant and appropriate. These
standards are most likely to be relevant and
appropriate at sites where stream and/or runoff
channelization is part of the remedy.
Sediment
(816.45)
Control Measures
Sediment control measures consist of proper mining and
reclamation methods and sediment control practices.
Sediment control methods include §816.45 (b) (1) - (3):
• disturbing the smallest practicable area at any mining
operation by backfilling, grading, and revegetation;
May be relevant and appropriate to CERCLA. If
remedial action involves sediment control
measures, performance standards should be met,
except for certain elements of §816.45 (b) (1) - (3)
that address active sites (e.g., disturbing smallest
practicable area). These standards are most likely
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D-49 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
stabilizing backfill material to promote a reduction in the rate
and volume of runoff;
• retaining sediment in disturbed area;
• diverting runoff;
• reducing overland velocity, run off volume, and trap
sediment; and .
• treating with chemicals.
Sediment control measures shall be designed, constructed, and
maintained to:
• , prevent additional sediment from entering the streamflow;
• meet more stringent State or Federal effluent limitations; and
minimize erosion.
to be relevant and appropriate for remedial actions
involving runoff diversion and/or slope stabilization
designed to control sedimentation.
Hydrologic Balance:
Structures (816.46)
Siltation Surface drainage from a disturbed area shall be passed through a
siltation structure before leaving permit area.
Siltation structures shaii be maintained until removal is authorized.
The land on which a siltation structure was located shall be
regraded and revegetated.
When sedimentation ponds are used they shall be:
• located as near as possible to the disturbed area;
• designed to:
provide adequate sediment storage volume;
' - meet effluent regulations by State and Federal effluent
limitation;
contain or treat 10-year, 24-hour precipitation events;
and
provide a non-clogging dewatering device adequate to
maintain detention time; and
• contain spillways. ;
When siltation structures (e.g., sedimentation
ponds) are required as part of the remedial action,
these requirements may be relevant and
appropriate and performance standards should be
met.
•*:
Hydrologic Balance:
Structures (816.47)
Discharge To reduce erosion, prevent deepening or enlargements of stream
channels, and minimize disturbance of hydrologic balance,
discharge from sedimentation ponds, coal processing waste dams,
embankments, and diversions shall be- controlled by: energy
dissioators. riprap channels, and other devices.
May be relevant and appropriate to CERCLA when
remedial action involves sedimentation ponds; per-
formance standards should be met.
Post-mining rehabilitation of sedi-
mentation ponds, diversions, im-
poundments, and treatment
facilities (816.56)
Before abandoning a permit area or seeking bond release, all
temporary structures shall be removed and all permanent
sedimentation ponds, diversions, impoundments, and treatment
facilities will meet permanent structure requirements, (in §816.49
(b)), which include:
May be relevant and appropriate to CERCLA when
remedial action involves sedimentation ponds; per-
formance standards should be met.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-50
A permanent impoundment of water may be created, if
authorized by a regulatory authority and the following is
demonstrated:
size and configuration of such impoundment is
adequate for purposes;
quality of water will be suitable for intended use, will
meet applicable State and Federal water quality stan-
dards, discharges will meet applicable effluent
limitations, and will not degrade receiving water below
applicable State and Federal water quality standards;
water level will be sufficiently stable and capable of
supporting use;
final grading will provide adequate safety and access
for water users;
impoundment will not result in diminution of quality
and quantity of water used by surrounding landowners
for commerce or regulation; and
impoundmentissuitableforapproved postmining land
use.
Backfilling and grading (816.102)
Disturbed areas shall be backfilled and graded to:
• achieve original contour;
• eliminate highwalls, spoil piles, and depressions;
• achieve a postmining site that prevents slides;
• minimize erosion and water pollution;
• support approved postmining;
• return spoil to mined-out areas;
• compact spoil and waste materials outside the mined-area in
non-steep slope areas to restore contour;
• dispose of coal processing waste and underground
development waste in accordance with §§816.81 and
816.83; and
• cover exposed coal seams, acid- and toxic-forming
materials, and combustible materials, exposed, used, or
produced during mining with nontoxic and noncombustible
material, or treat these materials to control their impact on
surface and groundwater.
Cut and fill-terraces may be allowed.
If the objectives of the remedial action involve
backfilling and grading, these requirements may be
relevant and appropriate to CERCLA, and SMCRA
performance standards should be met. These
requirements also should be evaluated for remedial
actions involving filling in of mined areas,
excavation pits, etc.
Backfilling and grading: previously
mined areas (816.106)
Remining operations on previously mined areas, containing a
preexisting highwall shall comply with §§816.102 through 816.107,
except as provided:
When remedial action involves remining, CERCLA
should follow performance standards. These are
especially likely to be relevant and appropriate
where remedial actions will involve on-site place-
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D-51 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Requirements of §816.102(a) (1) and (2) requiring the
elimination of highwalls do not apply where the volume of
spoil is insufficient to completely backfill the reaffected or
enlarged highwall.
The highwall shall be eliminated to the maximum extent
technically practical, in accordance with the following:
all spoil by remining operation shall be used to backfill
area and any reasonably available spoil in immediate
vicinity will be included;
backfill shall be graded to a slope which is compatible
with approved postmining land use;
any highway remnant must be stable, not posing a
hazard to safety; and
if moving spoil, placed on the outslope during previous
mining operations, will cause instability to remaining
spoil, it will not be disturbed.
ment of surface mine wastes in mine pits, shafts,
and subsidences, or where previous openings must
be sealed.
Backfilling and grading: steep
slopes (816.107)
Surface mining activities on steep slopes will be conducted to meet
requirements of §§816.102 - 816.106 and requirements of this
section except where mining is conducted on flat or gently rolling
terrain with an occasional steep slope through which mining
proceeds.
The following materials shall not be placed on a downslope:
• spoil;
• waste material of any type;
• debris from clearing and grubbing; and
• abandoned or disabled equipment.
Land above highwall shall not be disturbed unless regulatory
authority finds disturbance will facilitate compliance.
Woody materials shall not be buried in the backfilled area, unless
the regulatory authority determines otherwise.
When remedial action involves backfilling and
grading on steep slopes, performance standards
should be met. Remedial actions affected by these
requirements may include slope stabilization and
other measures to prevent erosion and/or runoff.
Revegetation - general
quirements (816.111)
re- On regraded areas and all other disturbed areas (except water
areas and surface area roads), the permittee shall establish a
vegetative cover that is:
• diverse, effective, and permanent;
• comprised of species native to the area or desirable and
necessary species;
• a cover equal to the natural vegetation of the area; and
• capable of stabilizing surface soil from erosion.
Revegetation requirements may be relevant and
appropriate to CERCLA when standards do not
exist for non-coal mining lands. In some cases,
these requirements may not be sufficient to protect
human health and the environment at a Superfund
site. However, they should be considered for sites
that are subject to erosion and soils are
contaminated as well as for sites where the
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-52
Reestablished plant species shall be:
compatible with approved postmining use;
have same seasonal characteristics as the area;
capable of self-regeneration;
compatible with plant and animal species of the area; and
meet State and Federal seed and plant regulations.
Regulatory authority may grant exceptions.
When regulatory authority approves of cropland postmining, the
authority may grant exceptions.
remedial action involves stream
diversion/channelization or filling of mine shafts.
Timing
Disturbed areas shall be planted during:
• first normal period for favorable plant growth after plant-
growth medium has been replaced; and
• the planting time generally accepted locally for the plant
materials selected.
These timing requirements may be relevant and
appropriate to CERCLA, if remedial action involves
revegetation.
Mulching and other soil stabilizing
practices
Suitable mulch and other stabilizing practices will be used on all
regraded areas, covered with topsoil. •
Regulatory authority may waive this requirement if seasonal, soil,
or slope factors do not require mulching and soil stabilization to
control erosion or maintain an effective cover.
Mulching and other soil stabilizing practices may be
relevant and appropriate to CERCLA, if remedial
action involves revegetation.
Standards for success
Judged on effectiveness of vegetation for postmining land use,
extent of cover vs. natural cover, and implementation of general
requirements. Evaluation requires:
• Valid sampling approach
• Comparison to unmined lands
• Meeting different criteria for grazing, cropping, fish/wildlife,
and industrial/ commercial/residential use
Specifies period of required husbandry, based on average precipi-
tation amounts
Revegetation requirements may be relevant and
appropriate to CERCLA when standards do not
exist for non-coal mining lands.
Superfund may incorporate additional goals into
successful revegetation related to specific plant and
animal conditions, as well as species appropriate
given remaining wastes on site.
Post-revegetation activities are considered
operation and maintenance and would be
addressed accordingly.
Post mining land use (816.133)
AH disturbed areas must be restored in a timely manner to
conditions capable of supporting
« Use capable of supporting before mining; or
• Higher or better uses
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-53
Requirements at Superfund Mining Sites
D.8.3 Implementation of the Fish and Wildlife Coordination Act at Superfund Mining Sites.
Remedial actions at Superfund mining sites will pften require alteration of natural bodies of water, due
to the nature of the sites. For example, at man^ mining site's, tunnel plugging will be necessary, or
surface water may have to be diverted around tailings or away from mine areas.
The RI/FS should describe any reports or recommendations of the FWS. When control or
modification of a water body is involved, the ROD should state whether each alternative will meet
substantive Fish and Wildlife Coordination Act requirements, and should briefly describe requirements
for the remedy selected, including the impacts, if any, of the response alternatives on wildlife and the
mitigation measures that would be employed.
D.9 EXECUTIVE ORDER 11990, PRO TECTION OF WETLANDS AND EXECUTIVE ORDER
11988, FLOODPLAIN MANAGEMENT
E.O.11990, Protection of Wetlands, requires federal agencies conducting certain activities to avoid, to
the extent possible, the adverse impacts associated with the destruction or loss of wetlands and to
avoid support of new construction in wetlands if a practicable alternative exists. The requirements of
this E.O. are spelled out in 40 CFR 6.302(a) and 40 CFR Part 6, Appendix A. E.O. 11988, Floodplain
Management, requires federal agencies to evaluate the potential effects of actions they may take in a
floodplain to avoid, to the extent possible, adverse effects associated with direct and indirect
development of a floodplain. The requirements of this E.O. are spelled out in 40 CFR 6.302(b) and 40
CFR Part 6, Appendix A. CERCLA actions at mining sites must consider these Executive Orders and
comply with the promulgated requirements, where they are determined to be ARARs.
The procedures for meeting the requirements of each Executive Order are similar. There are three
steps to meeting the requirements:
• The site manager must determine if proposed actions will be in or will affect a flood-
plain/wetlands. If it is determined that actions will not be located in or will not affect
a floodplain/wetlands, no further consideration of the requirements of these
Executive Orders is necessary.
• If actions will be in or will affect a floodplain/wetland, the site manager must prepare a
floodplains/wetlands assessment. This assessment will be part of the environmental
assessment.
• The site manager must either avoid adverse impacts or minimize them if no practicable
alternative exists.
Highlight D-18:
Fish and Wildlife Coordination Act as ARARs: Example Site
At the California Gulch site in Colorado, the remedial action included tunnel plugging that would modify streamflow. It also
required surface water diversions and construction of surge ponds that could affect the California Gulch. Because of these
remedial activities and their potential impact on fish and wildlife, EPA was required to consult with the FWS and the Colorado
Department of Natural Resources to determine the means and measures necessary to mitigate, prevent, and compensate
for project-related losses of wildlife resources and to enhance the resources. EPA received and responded to comments
on the FS alternatives and the proposed plan from both the Department of the Interior and the State of Colorado. In addition,
the state was consulted on the ROD.
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D-54 Appendix D: General Discussion of Applicable or Relevant and Appropriate
^ Requirements at Superfund Mining Sites
D.9.1 Standards (40 CFR 6.302(a) and (b), 40 CFR Part 6, Appendix A).
Floodplain/Wetlands Determination
• Before undertaking an action, EPA must determine whether or not the action will be
located in or affect a floodplain or wetlands.
• The Agency shall utilize maps prepared by the federal Insurance Administration of the
federal Emergency Management Agency, Fish and Wildlife Service, and other appropriate
agencies to determine whether a proposed action is located in or will likely affect a
floodplain or wetlands.
• If there is no floodplain/wetlands impact identified, the action may proceed without further
consideration of the remaining procedures set forth below.
Early Public Notice
• When it is apparent that a proposed or potential Agency action is likely to impact a
floodplain or wetlands, the public should be informed through appropriate public notice
procedures.
Floodplain/Wetlands Assessment
• If the Agency determines a proposed action is located in or affects a floodplain or
wetlands, a floodplain/wetlands assessment shall be undertaken.
• For those actions where an environmental assessment (EA) or environmental impact
statement (EIS) is prepared pursuant to 40 CFR Part 6, the floodpiain wetlands
assessment shall be prepared concurrently with these analyses and shall be included in
the EA or EIS. In all other cases, a "floodplain/wetlands assessment" shall be prepared.
• Assessments shall consist of a description of the proposed action, a discussion of its
effect on the floodplain/wetlands, and a description of alternatives.
Public Review of Assessments
• Where an EA/EIS is prepared, opportunity for public review will be provided by EIS
provisions. In other cases, an equivalent public notice shall be made.
Minimize, Restore, or Preserve
• If there is no practicable alternative to locating in or affecting the floodplain or wetlands,
the Agency shall act to minimize potential harm to the floodplain/wetlands.
• The Agency shall act to restore and preserve the natural beneficial values of flood-
plains/wetlands as part of the analysis of alternatives under consideration.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-55
Requirements at Superfund Mining Sites
Agency Decision
• After consideration of alternative action, the agency shall select the desired alternative.
• For all Agency actions proposed to be in or affecting a floodplain/wetlands, the Agency
shall provide further public notice announcing this decision.
• This decision shall be accompanied by a Statement of Findings, which shall include:
The reasons why the proposed action must be located in or affect the floodr
plain/wetlands; .
A description of significant facts considered in making the decision;
A statement indicating whether the proposed action conforms to applicable state or
local floodplain protection standards;
A description of the steps taken to design or modify the proposed action to minimize
potential harm to or within the floodplain or wetlands; and
A statement indicating how the proposed action affects the natural or beneficial
values of the floodplain or wetlands.
• If the provisions of 40 CFR Part 6 apply, the Statement of Findings may be incorporated in
the final EIS or in the environmental assessment. In other cases, notice should be placed
in the Federal Register or other local medium and copies sent to federal, state, and local
agencies and other entities which submitted comments or are otherwise concerned with
the floodplains/wetlands assessment.
Additional Floodplain Management Provisions
• EPA controlled structures and facilities must be constructed in accordance with existing
criteria and standards set forth under the National Flood Insurance Program (NFIP) and
must include mitigation of adverse impacts wherever feasible. Deviation from these
requirements may occur only to the extent NFIP standards are demonstrated as
inappropriate for a given structure or facility.
• If newly constructed structures or facilities are to be located in a floodplain, accepted
floodproofing and other flood protection measures shall be undertaken. EPA shall,
wherever practicable, elevate structures above the base flood level rather than filling land.
• The potential for restoring and preserving floodplains and wetlands so that their natural
and beneficial values can be realized must be considered and incorporated into any EPA
plan or action wherever feasible.
• If property used by the public has suffered damage or is located in an identified flood
hazard area, EPA shall provide on structures, and other places where appropriate,
conspicuous indicators of past and probable flood height to enhance public knowledge of
flood hazards.
• When property in flood plains is proposed for lease, easement, right-of-way, or disposal to
non-federal public or private parties, EPA shall reference in the conveyance those uses
that are restricted under federal, state, and local floodplain regulations and attach other
restrictions to uses of the property as appropriate.
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D-56 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D.9.2 Applicability of E.0.11990 and Other Wetlands Protection Requirements. In addition to
the requirements of 40 CFR Part 6, which requires that EPA initiate activities to avoid, to the extent
possible, long- and short-term adverse impacts associated with the destruction or modification of
wetlands, to avoid direct or indirect support of new construction in wetlands where there are
practicable alternatives, and to minimize potential harm to wetlands when there are no practicable
alternatives, section 404 of the Clean Water Act contains provisions for wetlands protection. Section
404 requires that no discharge of dredged or fill material shall be permitted if there is a practicable
alternative to the proposed discharge that would have less adverse impact on the aquatic ecosystem,
as long as the alternative does not have other significant adverse environmental consequences. (For
more information on CWA section 404, see the CWA section of this appendix.) Also, E.O. 11990
adopts a policy for federal agencies that wherever wetlands are destroyed or lost, wetlands of the
same magnitude will be enhanced or created.
Section 404 requirements and the 40 CFR Part 6 requirements are ARARs for different types of
actions and require different analyses. Section 404 requirements are only applicable when dredged
or fill material is placed into a wetland; therefore, excavation of wastes from a wetland would not
trigger these standards or require any analysis of "practicability." The 40 CFR 6.302 requirements are
potential ARARs whenever wetlands are affected, but E.O. 11990 itself is never an ARAR because it
is not legally promulgated or enforceable against the Agency by the public.
In deciding whether a wetland requirement is an ARAR, there may be some flexibility in determining
the meaning of "minimizing adverse effects to the extent possible" (under 40 CFR 6.302). Some
interpretation may be necessary because, in some cases, a response action at a Superfund site may
involve a discharge that may destroy an undegraded, functioning wetland. Examples of such an
action include the diversion of surface or groundwater through an existing wetland and building
access roads in wetlands. As a further example, a wetland may be contaminated, but if the wastes
are removed, the wetland will become a lake and the wetland will be destroyed. If the waste is left in
place, the wetland will be preserved, but the risk to human health and the environment will remain.
Site managers should try to avoid adverse impacts wherever possible; however, in some cases the
benefits gained by the response action may outweigh the adverse effects to the wetland. In fact,
avoiding the adverse effects may even be more harmful to human health and the environment than
preserving the wetland. In such instances, an ARARs waiver for greater risk to human health and the
environment may be appropriate (see the section on ARARs waivers in this appendix). (Wetlands
creation to replace destroyed wetlands may also be required.)
D.9.3 Implementation of Wetlands Protection Requirements at Mining Sites. An innovative
technology for treating acid mine drainage (AMD) from Superfund mining sites may be affected by
wetlands protection requirements. In this treatment, AMD is allowed to flow through artificial wetlands,
which filter out contaminants. If these artificial wetlands are constructed in a natural wetland, the
requirements of 40 CFR Part 6 may be applicable. Also, if construction involves placing dredged or fill
material into a natural wetland, the site manager should consider CWA section 404 as a potential
ARAR. Finally, if natural wetlands rather than artificial wetlands are used for this type of treatment,
this may also trigger Part 6 requirements.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-57
Requirements at Superfund Mining Sites
D-19: ^ £
Wetlands/Floodplains Requirements as ARARs: Example Site
The Anaconda Smelter/Mill Creek site in Montana is located within the 100-year floodplain of Mill Creek. EPA also
determined that riparian woodland/shrubland at the site is a wetland. Demolition activities will occur within the wetland area.
The following management practices will be utilized during demolition and site stabilization activities:
• Mechanized equipment will be used in a manner that minimized effects to wetland vegetation.
• No new roads will be constructed.
• Following demolition, building foundations will collapsed and filled, and the area regraded and smoothed to
conform to the existing topography and to facilitate drainage.
• Riparian vegetation rendered non-viable during demolition activities will be removed and replaced with like
vegetation.
• Disturbed areas will be mulched with straw and seeded with grasses.
D.10 NATIONAL HISTORIC PRESERVATION ACT
The Historic Sites Act (HSA) of 1935, The National Historic Preservation Act (NHPA) of 1966, and the
Archeological and Historic Preservation Act (AHPA) of 1974 are designed to protect the Nation's
historical heritage from extinction. Because of the CERCLA section 121 mandate to comply with
those requirements of other federal and state environmental laws that are ARARs, Superfund actions
are required to take into account the effects of any response activities on any historic properties or
cultural resources regulated under these laws. If no cultural resources or historic properties are
present at an NPL site, the NHPA and other laws are not considered an ARAR for the proposed
response activity. If a cultural resource on or eligible for inclusion on the National Register of Historic
Places is present at an NPL site, however, the NHPA may be considered an ARAR. In this case, EPA
must determine what effect a Superfund response activity (i.e., a removal or remedial cleanup activity)
will have on an .identified cultural resource. If cultural resources are present, the ROD or removal
action memorandum should identify the NHPA as an ARAR. For each alternative, the ROD should
identify whether the alternative will comply with substantive NHPA requirements. For the selected
remedy, the ROD or action memorandum should also include a brief statement describing what
compliance with the NHPA entails.
This section discusses how to determine whether the NHPA and other historic preservation laws are
ARARs and the steps that must be taken to ensure that remedial activities at mining sites comply with
the NHPA. Highlight D-20 provides more information on the historic preservation laws.
D.10.1 Implementing Historic Preservation Requirements. The Department of Interior has formed
the Advisory Council on Historic Preservation (ACHP) and the National Register of Historic Places to
implement these historic preservation laws. The National Register of Historic Places lists the nation's
cultural resources that should be considered for protection from destruction or impairment. The
National Register is not an all inclusive list (i.e. not every historical site that should be protected has
been included in the National Register at this time). Consequently, historic properties that may be
eligible for inclusion on the National Register must also be protected under these laws. Procedural
requirements for listing properties on the National Register are listed in 36 CFR 60.1. The criteria
applied to evaluate whether cultural resources will be eligible for inclusion on the National Register,
including those found at Superfund sites are found in 36 CFR 60.4 and are summarized in Highlight
D-21. Executive Order 11593, revised on May 13, 1971, "Protection and Enhancement of the Cultural
Environment," requires federal agencies to locate, inventory and nominate all sites, buildings, districts,
and objects under their jurisdiction or control for listing on the National Register of Historic Places.,
Under this Executive Order, EPA must undertake these activities when such sites are addressed as
part of the Superfund program.
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D-58 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Highlight D-20:
Historic Preservation Laws
The Historic Sites Act of 1935 authorizes the Secretary of the Interior to designate areas as national landmarks for listing
on the National Registry of Natural Landmarks. Under this Act, federal agencies, or responsible parties under the direction
of a federal agency, are required to avoid undesirable impacts on such landmarks. Under the Archeological and Historic
Preservation Act, if a federal agency, or responsible party under the direction of a federal agency, conducts an activity that
may cause irreparable loss or destruction of significant scientific, prehistoric, historic, or archeological data, the Secretary
of the Interior is authorized to undertake data recovery and preservation activities. The National Historic Preservation Act
(NHPA) of 1966 established a program forthe preservation of historic properties throughout the nation. The NHPA requires
the federal government to encourage government agencies and individuals undertaking activities to preserve the cultural
foundations of the Nation. The NHPA also requires that the federal government assist state and local governments to
exoand their historic oroqrams and activities. ,
The ACHP oversees the protection of properties of historical, architectural, archeological, and cultural
significance at the national, state, and local level. Under section 106 of the NHPA and Executive
Order 11593, federal agencies must provide the Advisory Council on Historic Preservation a
reasonable opportunity to comment on activities that may affect properties on or eligible for listing on
the National Register of Historic Places. For Superfund, a Memorandum of Agreement (MOA)
between EPA and DOI provides the framework of the actions agreed upon to implement the NHPA at
Superfund sites.
The State Historic Preservation Officer (SHPO) is the official responsible pursuant to section 101(b)(1)
of the NHPA for administering the state historic preservation program within each state or jurisdiction.
For Superfund response actions, the SHPQ serves as a liaison between EPA and the ACHP, and
should be viewed as a technical resource to assist in determining if NHPA requirements are ARARs,
and if so, how EPA must comply. The SHPO participates in the review process established by the
NHPA when a federal agency's proposed activity occurs within the SHPO's jurisdiction. Although
compliance with the NHPA rests with the federal agency implementing the action, EPA staff may not
be as familiar with historic issues as the SHPO. Consequently, the SHPO can and should play an
important role in the ARARs evaluation compliance process for this law. Coordination should be
maintained among EPA, the state environmental protection department, and the SHPO to ensure full
utilization of existing staff expertise in the historic preservation planning process and in the treatment
of historic properties affected by the proposed remedial or removal actions. If mitigation measures
are necessary to comply with the NHPA, they will occur more readily if the SHPO is involved early in
the RI/FS process.
Highlight D-21:
Criteria for Inclusion of a Cultural Resource on the National Register of Historic Places
Cultural resources that may be placed on the National Register include those that:
• Are associated with events that have made a significant contribution to the broad patterns of our history;
• Are associated with the lives of persons significant in our past;
• Embody the distinctive characteristics of a type, period, or method of construction, or that represent the work
of a master, or that possess high artistic values, or that represent a significant and distinguishable entity
whose components may lack individual distinction; or
• Have yielded, or may be likely to yield, information important in prehistory or history.
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-59
D.10.2 Complying With the Historic Preservation Laws. Compliance with the NHPA during
Superfund response action requires that EPA,:the state lefd agency, or the private party taking a
CERCLA section 104 or CERCLA section 106 action:
• Identify cultural resources on or eligible for inclusion on the National Register of Historic
Places;
• Determine the effect a proposed activity will have on the identified cultural resources; and
• Avoid, minimize, or mitigate any adverse effects during implementation of the action.
In order for the Record of Decision (ROD) to be developed in a timely manner, the demonstration of
compliance with the NHPA must be done as part of the Feasibility Study. During the Feasibility Study
the various alternatives being considered must be evaluated for compliance with all ARARs. To
ensure compliance with the NHPA, the EPA site manager should begin working with the SHPO and
ACHP in the very early stages of the Superfund process. If at any point in the compliance process it
is determined that cultural resources are not present or will not be affected by the proposed activity,
no further investigation is required.
Identification of Properties on or Eligible for inclusion on the National Register of Historic
Places
Identification of cultural resources on, or that may be eligible for inclusion on, the National Register of
Historic Places is the first step towards compliance with the NHPA. Identification should be made in
the very early stages of an RI/FS (e.g., scoping), before conducting investigation activities that disturb
the site, (e.g. well drilling). EPA or lead agency consultation with the SHPO is the first stage in the
identification process. EPA in conjunction with the SHPO, is responsible for determining whether the
area of planned remedial action includes any historic properties. "The Agency Official shall consult
the State Historic Preservation Officer, the published lists of National Register and eligible properties,
public records, and other individuals or organizations with historical and cultural expertise, as
appropriate, to determine what historic and cultural properties are known to be within the area of the
undertaking's potential environmental impact" (40 CFR section 800.4(1)). In many cases, mining sites
may be historical landmarks, and when they are subject to remedial actions, it may be necessary to
consider the effects of the actions on the landmark. (See Highlight D-22.)
Highlight D-22:
Examples of the NHPA as an
California Gulch
The Yak tunnel at the California Gulch mining site in Leadville, Colorado is considered a historical landmark due to its
historical association with mining engineering in the 19th and 20th centuries. Therefore, CERCLA must take into account
any adverse effects at this facility.
Clark Fork
Many mining areas along the Clark Fork, including the areas around the city of Butte, Montana, are considered historical
landmarks due to their historical association with mining. Cleanup activities at the Clark Fork sites could alter certain
historical structures within the local community. In order to comply with the NHPA, EPA and the state have produced a
historical film to document historical resources prior to any cleanup activities. ;
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D-60 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
When determining whether the area of planned remedial action includes any historic properties, the
SHPO and EPA should consider the following factors:
• The area of potential effects of the remedial action (i.e., extent of the effects of potentially
disturbing investigation activities and response action);
• Existing information on historic properties already identified that are potentially affected by
the action;
• The likelihood that there are unidentified historic properties within the area of potential
effects; and
• Further actions that may be necessary to identify historic properties that may be affected.
The MOA between EPA and DOI specifies that once contacted, the SHPO will respond to EPA's
request to determine whether the area of planned remedial action includes any historic properties
within 30 days.
After consulting with the SHPO, the lead agency determines what, if any, further actions are
necessary to locate and identify cultural resources. If the SHPO has inadequate information to
document the presence or absence of historic properties in the project area, the SHPO may suggest
that the lead agency conduct a professional cultural resource survey (CRS). The analysis to
determine whether a CRS is necessary should be conducted prior to developing the RI/FS
workplan. In this way, requirements to conduct a CRS can be met during the course of early Rl
activities, allowing a determination to be made whether the detailed analysis of alternatives will have
to evaluate compliance with the historic preservation laws as ARARs. In some cases, cultural
resources may not be discovered until after the RI/FS has started, or until after the ROD or Action
Memo is signed and implementation of the design or action has started. Where the resource is
identified before the ROD is signed, the RI/FS plans should be revised to accommodate and include
the CRS. Where the resource is discovered after the ROD or action memo is signed, the site
manager should work with the SHPO to undertake a CRS. If the CRS shows potential impacts of the
action on the resource, an explanation of significant differences (ESD) may be used to make any
necessary adjustments in the remedy.
The purpose of the CRS is to identify cultural resources within the project area and develop
information required to apply the National Register's criteria for evaluation (see Highlight D-21). The
CRS includes research conducted on each identified resource to determine:
• Whether the resource is eligible for listing on the National Register;
• The effects an activity will have on the cultural resource; and
• Ways to avoid or reduce the effects on any cultural resources.
Highlight D-23 highlights the factors to consider when determining the need for a CRS.
If EPA determines that a CRS is necessary, cultural resource plans outlining the scope of work and
schedule for completion of the CRS should be incorporated into the appropriate RI/FS and/or RD
workplans. Data from the CRS report should be incorporated into the RI/FS environmental evaluation.
The decision whether to undertake a CRS rests with EPA, but SHPO opinions should be strongly
considered in making the final determination.
Stage I of a CRS is designed to determine the presence or absence of cultural resources in the
potential impact area. This process generally requires conducting documentary research and/or a
field investigation (e.g., limited excavation or site surveillance in a potentially affected area, interviews
with knowledgeable resources). The activities of a Stage I investigation should be part of Rl work
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-61
^ Requirements at Superfund Mining Sites
conducted on the site. Stage II of the CRS, if .necessary, is a derailed evaluation of an identified
cultural resource that may be affected by the remedial alternatives being considered. Stage I! of a
CRS is conducted only if it is determined that a proposed response activity will affect resources
identified in Stage I. Highlight D-24 defines in more detail the major components of each stage of a
CRS.
Highlight D-23:
Factors to Consider When Determining the Need for a CRS1
Type and scope of the response activity under preliminary consideration;
Nature and extent of the physical disruption likely to be associated with the undertaking;
Environmental characteristics of the planning area;
Type of direct and indirect impacts anticipated in the planning area;
Data gathered from a field inspection of the proposed planning area, including photo-documentation of any potential
cultural resources that may be directly or indirectly impacted; and
• Recommendations of the SHPO and other appropriate state agencies, and state and local historic preservation
groups, local governments, Indian Tribes, and other parties likely to have knowledge of historic properties in the area.
1 Thp effect of these factors on makina a decision whether to undertake a CRS should be documented in the RI/FS report.
If the lead agency and the SHPO agree that no identified property on, or eligible for inclusion on, the
National Register is located within the area of the proposed activity, the lead agency official should
document this finding in the RI/FS report. Unless the Secretary of the Interior disagrees with this
determination, the response action may proceed with the proposed activities. If the SHPO and
agency official identify a cultural resource in the area of a proposed response, however, the criteria
listed in Highlight D-21 are applied to determine whether the property is eligible for inclusion on the .
National Register (if it is not already being considered or listed): Provided that the SHPO and EPA
agree that a property should be included in the National Register, either the SHPO or EPA site
manager official should forward the following documentation to the Keeper of the National Register:
• A letter signed by EPA stating that EPA and the SHPO agree that the property is eligible
for inclusion on the National Register; and
• A statement signed by the SHPO that in his opinion the property is eligible for the National
Register.
Stage I:
Stage II:
Highlight D-24:
Major Components of a Cultural Resource Survey
Documentary Research activities include researching sources at the State Historic Preservation Office, local
governments, universities, local libraries, museums, and historical societies. The Stage I research survey
should also include a synthesis of land use patterns, and prehistoric and historic cultural development of the
project area.
Field Investigation involves subsurface testing. A record and description of cultural resources including their
location on the site is also completed during the Field Investigation of Stage I.
The Stage II report of the CRS should include information on boundaries, integrity, and significance of the
resource(s), and evaluation of the effect of the proposed project. '
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D-62 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
The Keeper of the National Register will give written notice of his determination to both the SHPO and
the EPA site manager 10 working days of receipt. If the SHPO and agency official disagree about the
eligibility for inclusion on the National Register, the EPA site manager should submit a letter of request
for a determination of eligibility with a description, statement of significance, photographs, and a map
to the Keeper of the National Register. The opinion of the SHPO should also be forwarded with the
request, if available. The Keeper of the National Register will respond in writing to the agency's
request within 45 days of receipt of the request. Only properties subsequently listed on the
National Register will have to comply with the step of the NHPA process that determines if the
proposed activity will affect the resource. For properties not listed at this stage, the NHPA and
other laws are not considered ARARs.
Determination of Effect
Identifying the possible effects of response actions on each cultural resource that is on, or eligible for
inclusion on, the National Register is the second step towards compliance with the NHPA. "A federal
activity is considered to have an effect on a cultural resource whenever the activity causes or may
cause any change, beneficial or adverse, in the quality of the historical characteristics that qualify the
cultural resource for inclusion on the National Register." (36 CFR 800.3(a)) The EPA site manager, in
consultation with the SHPO, will make one of the following determinations of the effect of the
response action for each of the alternatives considered in the RI/FS Detailed Analysis of Alternatives
Stage:
• No effect;
• No adverse effect; or
• Adverse effect
Determination Of No Effect
If the SHPO and agency official agree that a response action will have no effect on historic properties,
the agency official should document this determination which is then made available for public review.
If either the SHPO or the agency official objects, the Executive Director of the ACHP reviews the
determination and notifies the objecting party of his decision within 15 days.
Determination of No Adverse Effect
If the agency official or Executive Director of the ACHP determines that a response action will affect a
cultural resource eligible for inclusion on the National Register, the agency official in consultation with
the SHPO, shall determine whether the effect is an adverse effect. Highlight D-25 provides several
definitions of adverse effects, if the agency official and the SHPO determine that a response action
will have no adverse effect on the cultural resource, the agency official is responsible for submitting
adequate documentation of this determination to the Executive Director of the ACHP which is
available for public review. Highlight D-26 lists the information to be included in the RI/FS report or
action memo to document a no adverse effect finding as required by 36 CFR 800.13(a). The regula-
tion also states that there must be the opportunity for public review and comment on this finding.
Provided that no objection has been made by the public, the SHPO, or any interested party, upon
receipt of the documentation of no adverse effect, the Executive Director of the ACHP will normally
concur without delay. If the Executive Director determines that the documentation of no adverse
effect is inadequate, the Executive Director will notify the agency official within 15 days. Unless the
Executive Director objects within 30 days, the agency official will have satisfied the requirements
under the NEPA and may proceed with the proposed activity. If the Executive Director objects, the
Executive Director will specify conditions that will eliminate the objection. The agency official may
either accept the Executive Director's conditions in writing and proceed with the proposed activity, or
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Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
D-63
reject the Executive Director's conditions, in which case the Executive Director should initiate the
consultation process.
Determination of Adverse Effects
Should the agency official determine that ah activity, including ones designed by Superfund to protect
human health and the environment, will have an adverse effect on an historic property, or the
Executive Director of the ACHP rejects the agency's determination of no adverse effect, the lead
agency should prepare and submit documentation that outlines how the lead agency is going to avoid,
minimize, or mitigate the adverse effects of a remedial activity to the Advisory Council for comments.
This type of documentation is referred to as a Preliminary Case Report. A separate case report does
not need to be prepared for a site. Instead, this information should be incorporated into the RI/FS
Report, Proposed Plan, and the ROD. Highlight D-27 lists the type of information that should be
included in the ROD or action memo to document a finding that the action will have an adverse effect.
Upon receipt of the Council's comments, the lead agency shall take the comments into account when
reaching a final decision regarding the proposed activity. Highlight D-28 provides examples of
mitigation measures the ACHP has suggested in the past. Given the lack of specific guidance in
terms of what mitigation measures might encompass, EPA, PRPs, and the local community should
negotiate with each other to clarify what mitigation measures are and how they should be
implemented. If parties do not identify mitigation measures at appropriate times, mitigation measures
change after the ROD is signed, or financial requests are not within available resources, EPA may not
be able to fund implementation of the measures. Given a lack of funding, other parties (e.g., PRPs,
communities) may be more appropriate to implement certain mitigation measures requested by the
SHPO.
When agreement is reached on how the effects will be taken into account, the Executive Director of
the ACHP will prepare a Memorandum of Understanding (MOU) reflecting such agreement. Typically,
the RPM prepares a proposal for inclusion in the MOU that details the actions agreed upon to avoid,
mitigate, or accept the adverse effects on the property. If the Executive Director determines that the
proposal accurately represents the agreement, the RPM's proposal is forwarded to the Chairman of
the ACHP for ratification.
Highlight D-25:
Definition of Adverse Effects
Adverse effects may include, but are not limited to, the following:
• Physical destruction, damage, or alteration of all or part of the property;
• Isolation of the property from or alteration of the character of the property's setting when that character
contributes to the property's qualification for the National Register;
• Introduction of visual, audible, or atmospheric elements that are out of character with the property or alter its
setting;
• Neglect of the property resulting in its deterioration or destruction; and
• Transfer, lease, or sale of the property.
SOURCE: CERCLA Compliance With Other Laws Manual.
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D-64 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
Highlight D-26:
Information to be Included in Documentation of No Adverse Effect
The requirements of 36 CFR 800.13(a) state the following must be included when documenting a "no adverse effect" finding.
A description of the agency's involvement with the proposed activity with citations of the agency's program
authority and applicable implementing regulations, procedures, and guidelines;
• A description of the proposed activity, including as appropriate, photographs, maps, drawings, and
specifications:
A list of National Register and eligible properties that will be affected by the proposed activity, including a
description of the property's- physical appearance and significance;
A brief statement explaining why the proposed activity will have no adverse effect on the cultural resource;
• Written views of the SHPO concerning the determination of no adverse effect, if available; and
• An estimate of the cost of the proposed activity, identifying federal and non-federal shares.
SOURCE: 36 CFR 800.13(a)
Highlight D-27:
Information Required in the ROD or Action Memo to Document Adverse Effect
The ROD or action memo should include the following information, as required by 36 CFR 800.13(b):
A description of the proposed activity, including, as appropriate, photographs, maps, drawings, and
specifications; .
A description of the National Register or eligible properties affected by the proposed activity, including a
description of the properties' physical appearance and significance;
A brief statement explaining why the proposed activity will adversely affect the cultural resource;
Written views of the SHPO concerning the effect on the property, if available;
The views of other federal agencies, state and local governments, and other groups or individuals, when
known;
A description and analysis of alternatives that would avoid the adverse effects;
A description and analysis of alternatives that would mitigate the adverse effects; and
An estimate of the cost of the proposed activity, identifying federal and non-federal shares.
Highlight D-28:
Examples of Mitigation Measures
Producing historical films;
Videotaping\photographing landscape for documentary purposes;
Designating land to the historical society;
Modifying workplans to preserve historical structures (One mining facility preserved historical wooden pipes by
revising design plans around the pipes); and
Constructing state parks or museums.
D.10.3 Cultural Resources Discovered After Complying with the NHPA. In some cases, a
federal agency may identify a cultural resource eligible for inclusion on the National Register of
Historic Places after completing all its responsibilities under section 106 of the NHPA. Unless the
Secretary of the Interior determines that the significance of the property, the effect, and any proposed
mitigation actions warrant Council consideration, the federal agency may fulfill its responsibilities
under section 106 of the NHPA by complying with the requirements of the Archeological and Historic
Preservation Act. The Archeological and Historic Preservation Act provides for the preservation of
historical and archeological data that might be lost or damaged as a result of a proposed activity. If a
federal activity may cause irreparable loss to significant scientific, prehistoricai, or archeological data,
the Act requires the federal agency to preserve the data or request the Department of the Interior to
do so. The Archeological and Historic Preservation Act mandates only the preservation of the data. If
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Appendix D: General Discussion of Applicable or Relevant and Appropriate D-65
Requirements at Superfund Mining Sites
the Secretary of the Interior determines that the Council's comments are warranted, the agency official
should request the comments of the Council and repeat the procedure discussed in section 3.0.
ft\ "*: •$
If it is determined that the identified cultural resource will not be affected by the remedial activity, EPA
must document this determination. Provided that the Executive Director of the ACHP does not object
to this determination, EPA will have satisfied the requirements of the NHPA. If EPA and the SHPO
determine that a remedial activity will have no adverse effect on a cultural resource, EPA shall
document that determination, carry out any agreed-upon conditions accompanying the SHPO's
concurrence, and provide the Advisory Council on Historic Preservation with the determination.
D.10.4 Summary of RPM's Responsibilities to Ensure Compliance with the NHPA. Compliance
with the NHPA can be broken down into five major steps:
1. Determine whether cultural resources that are on, or eligible for inclusion on the National
Register of Historic Places are located in or near the area under study in the Rl;
2. Determine whether a cultural resource survey is necessary;
3. Determine whether identified resources are on or eligible for inclusion on the National
Register of Historic Places;
4. Determine the effect affect a proposed response activity will have on a property on, or
eligible for inclusion on the National Register of Historic Places; and
5. Develop mitigation measures if proposed activities will have an adverse effect on a cultural
resource.
The RPM should complete the first four steps in the very early stages of an RI/FS, prior to conducting
sampling activities on mine waste NPL sites. The RPM should conduct the fifth and final step during
the Feasibility Study, when the various alternatives are evaluated for compliance with all ARARs. It is
not realistic to select a remedial action and then determine what the appropriate compliance/mitigation
procedures will be during the ROD process. Developing mitigation measures during the Feasibility
Study will ensure that the Record of Decision can be developed in a timely manner.
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D-66 Appendix D: General Discussion of Applicable or Relevant and Appropriate
Requirements at Superfund Mining Sites
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Appendix E
X-Ray Fluorescence
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Appendix E: X-Ray Fluorescence
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Appendix E: X-Ray Fluorescence
Table of Contents
E.1 Introduction
E.2 Elements of Interest and Detection Limits .
E.3 Equipment Options and Turnaround Times
E.4 Special Considerations When Using XRF .
EAA Site-Specific Calibration Samples
E.4.2 Sample Preparation
E.4.3 Interferences
E.4.4 Sample Variance Calibration
E.4.5 Counting Time
E.5 Quality Control
E.6 Examples of Site Projects Using XRF
E-1
E-1
E-2
E-3
E-4
E-4
E-4
E-5
E-5
E-6
E-6
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Appendix E: X-Ray Fluorescence
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Appendix E
X-Ray Fluorescence
The purpose of this appendix is to identify the parameters that must be considered when
applying the x-ray fluorescence (XRF) analytical method at a field site to achieve the necessary
quality of chemical data for soils and other heterogeneous solids to meet project objectives.
This appendix presents information about the use of XRF based on two extremes:
enforcement-quality on-site analysis and field screening analysis. It is a supplement to existing
EPA guidance providing procedures'-for determining a quantifiable degree of certainty upon
which to make site-specific decisions focusing on the use of the XRF method of analysis at the
site. ,
E.1 Introduction
XRF technology has greatly expanded since Moseley discovered the importance of x-ray
spectra in 1913. Instruments with reduced detection limits have been devebped for a broad
spectrum of elements and have become portable. XRF instruments can now be taken to the
sample by a single individual and a screening analysis performed in less than a minute, with
reasonable precision and accuracy.
XRF is being applied to Remedial Investigation/Feasibility Study (Rl/FS) and cleanup sites to
increase the representativeness of sampling, expedite the activity by performing real-time data
analysis to support decisionmaking, and decrease both the time and cost of these activities.
XRF analytical determinations are nondestructive and total analyses of chemical elements
require minimal sample preparation. Consequently, XRF instruments are finding increased use
in environmental studies.
Application of the XRF method depends on the project objectives and associated data quality
objectives. The decision to use XRF at a site may occur during the first stage of devebping the
data quality objectives, but the application is generally defined in the second and third stages.1
As with any method of analysis, precision and accuracy start with the sample collection and
continue through each stage of the analysis until the chemical data are reported. Comparability
of data produced by XRF with data from EPA's Contract Laboratory Program (CLP) has been
established by field tests of XRF instruments. Representativeness and completeness are two
of the major advantages of XRF use. On-site, real time chemical analysis can document
representativeness and allows critical samples to be collected and analyzed, which typically
ensures completeness.
£.2 Elements of Interest and Detection Limits
Radioisotope sources used in field-portable and semi-portable instruments include iron-55,
cadmium-109, americium-241, and curium-244. Different sources are used for different
elements of interest. For example, Cdl09 and Cm244 are typically used for chromium,
manganese, iron, cobalt, nickel, copper, zinc, arsenic, and lead, and Am241 is typically used for
silver, cadmium, antimony, and barium.
; U.S. Environmental Protection Agency, 1987, Data Quality Objectives for Remedial Response Activities, Development
Process: EPA/540/g-87/004 (OSWER Directive 9355.07B).
-------
E-2 Appendix E: X-Ray Fluorescence
EPA's Environmental Monitoring Systems Laboratory (EMSL) has produced a sampling and
analysis protocol for the use of a field portable XRF. Examples of the chemical analysis by a
field portable instrument are documented to produce instrument detection limits of 15 to 90
milligrams per kilogram (mg/kg)for arsenjc (two sites) and 30 to 140 mg/kg for lead, copper,
zinc, and iron.2 Typical method detection limits are not less than 50 mg/kg with a coefficient of
variation between 5 and 10 percent but are often in the 100 to 200 mg/kg range with a
coefficient of variation of 3 to 25 percent The increase in detection limit is a result of using a
lower x-ray source (radioisotopes) and a gas proportional detector in the field portable XRF
instruments.
Prototype ithium drifted silicone (Si(Li)) probes are being developed that have the potential to
lower the detection limit to less than 100 mg/kg for most heavy metals (copper, zinc, arsenic,
lead, etc.).3 A semi-portable unit is currently available that uses sample cups for sample input
rather than a surface probe. The semi-portable XRF instrument probably has an intermediate
detection limit range between the field portable and the mobile unit. However, in selected
instances, the semi-portable instrument may function almost as well as the mobile XRF
instrument for selected elements. Similar to the field portable instrument, the semi-portable
instrument uses a radioisotope as a source.
Mobile laboratory results have well-documented lower limits of detection of 4 mg/kg for
cadmium, 7 for lead, 12 for arsenic, 19 for zinc and iron, 21 for manganese, and 26 for copper.4
In these tests, the samples were sieved and pulverized to a powder. A fundamental
parameters model was used to calculate concentration from measured XRF intensity.
E.3 Equipment Options and Turnaround Times
Media that are commonly appropriate for XRF analysis include soils, in particular, but
essentially all soids, as well as liquefied solids, such as sludges and slurries. Detection limits
extend from mg/kg (parts per million) to the 100 percent range for mobile XRF instruments and
from tens to hundreds of mg/kg to 100 percent for field portable instruments. These detection
limits are not appropriate for typical surface and ground water; therefore, CLP laboratories are
recommended for samples of these media. Samples analyzed by XRF, especially critical
samples, are submitted to a CLP laboratory or equivalent laboratory for calibration and
consultory chemical analysis.
Field portable instruments are more useful than mobile instruments in a site investigation.
Field-portable instruments are those equipped with radioisotope source(s), generally gas
proportional tube detectors, usually weighing less than 20 pounds (including batteries) and can
be carried in one hand to the sample location. Semi-portable instruments are those instruments
' Chappell, R.W.. Davis. A.O., and Olsen. R.L, 1986. Portable X-Ray Fluorescence as a Screening Tool for Analysis of Heavy
Metals in Soils and Mine Wastes: Proc. Natl. Conf. on Management of Uncontrolled Hazardous Waste Sites, Washington, DC. pp.
115-119.
1 Piorek, S.. and Pasmore. J.R.. 1991, A Si(Li) Based High Resolution Portable X-Ray Analyzer for Field Screening of Hazardous
Waste: Second Intl. Symposium, Field Screening Methods for Hazardous Wastes and Toxic Chemicals. EMSL, Las Vegas, NV, 5p.
4 Harding, AR., 1991, Low Concentration Soil Contaminant Characterization Ushg EDXRF Analysis: Second Intl. Symposium,
Field Screening Methods for Hazardous Wastes and Toxic Chemicals. EMSL, Las Vegas. NV, 7p.
-------
Appendix E: X-Ray Fluorescence E-3
that may be equipped with radioisotopes but are equipped with a Si(Li) detector, weighing more
than 20 pounds (including batteries) but canjstill be carried by one person to a site, and
samples are placed in a cup for analysis by the instrument. Mobile instruments use an x-ray-
tube for the x-ray source and, therefore, require line voltage, and are usually placed within a
specific building near or at the site to generate enforcement quality data.- Instruments can also
be installed in a van. They can be moved from site to site but normally would be retained at a
site until analytical data are no longer necessary (potentially months).
An initial field investigation using a field portable XRF involves gridding the site and determining
relative concentrations for a suite of .elements at all points in the grid. Hot spots are identified
and their nature and extent characterized before leaving the field. A suite of representative
samples are collected and sent to a CLP laboratory for a "broad spectrum analysis" that
documents the concentrations of hot spot and peripheral elements for the site. Contaminated
areas of concern within the site are thereby documented from the initial XRF work by converting
field readings to absolute concentrations with a known, documented accuracy and precision.
Mobile XRF instruments are more appropriate for sites undergoing cleanup activities. A mobile
XRF instrument can be installed in a section of a typical room near the site. Samples can be
collected, prepared, brought to the hstrument, and analyzed in a matter of a few hours.
Analytical quality can be comparable to a CLP or equivalent laboratory. Comparability is
documented by split samples sent to a CLP laboratory. Decisions concerning the attainment of
an action level can be made quickly at the site. Coupling the use of a field portable and mobile
laboratory instruments at a site would allow almost immediate decisions to be made concerning
an action level in the field that can be confirmed by the mobile laboratory doing routine remedial
action samples. Ultimately, a representative composite sample from the site area under
remedial action is sent to the CLP or equivalent laboratory for final documentatbn of the clean
up level.
E.4 Special Considerations When Using XRF
All XRF instruments begin with the total counts received by the detector for an energy that is
specific for each element. The detection limit, accuracy, and precision of the measurement is
directly determined by the magnitude of the total counts and resolution width of the peak. The
total counts are expressed as intensity in counts per second.
The analytical capability of an XRF instrument depends on excitation source, source-to-sample
geometry, instrument stability, counting time, and sample matrix. Commerciai instruments are
available for both enforcement and screening analyse. Analysis for enforcement data requiring
low concentrations of a broad spectrum of selected elements (on the order of 10 mg/kg) uses
semi-mobile, x-ray-tube-sourced instruments equipped with crystal detectors (for example,
Si(Li) detectors). Analysis for screening data allows a broad spectrum of elements to be
semiquantitatively determined using radioactive sources that are limited by safety regulations to
5 and 6 orders of magnitude lower x-ray emission than x-ray tubes. This limitation is partially
compensated for by the nearly monochromatic x-ray source with closer source-to-sample
geometry that allows a reasonably low detection limitfor many elements. High resolution gas-
proportional tubes are the niost common detectors but Si(Li) detectors are available for both
semi-portable, and most recently for portable instrumentation.
-------
E-4 Appendix E: X-Rav Fluorescence
E.4.1 Site-Specific Calibration Samples
An initial set of site samples is required for calibration purposes. The samples should cover the
matrices and concentration range of elements of concern as determined by a total metals
(hydrofluoric acid digestion) analysis by a CLP or equivalent laboratory. The samples should be
prepared by the laboratory using the same protocol that will be used at the site. This initial set
of samples is best collected using the field screening instrument to determine that samples are
representative of media (potential for stratification), elements of concern, and concentration
ranges. Similarly, preparation of samples for XRF analysis by the field preparation facility is
preferable to preparation by a fixed laboratory using other equipment and protocols. EMSL has
protocols for the collection, preparation, and analysis of a suite of site-specific calibration
standards.
E.4.2 Sample Preparation
At the sample location, a field-portable instrument is equipped with a probe that allows
considerable flexibflity in how a sample is presented to the source. It may be pressed against
the media of interest (soils, ta'lings, walls, etc.) ora sample cup of material (soil, slurry, sludge,
etc.) can be placed on top of the source. Samples may be sieved or pulverized but sample
preparation is typicaDy minimal. Field-portable instruments are versatile but have the highest
detection limits of the three types of instruments. Typical detection limits with little to no sample
preparation are in the 100 mg/kg range, depending on sample matrix Instruments vary in the
amount of data processing that they provide. Some give minimal processing, reporting in
intensity (total counts or total counts divided by backscatter). Others are capable of processing
the data to report in mg/kg concentration units.
The semi-portable instruments have a potential detection limit equal to that of the larger mobile
instruments. The semi-portable instalment requires the use of a sample cup, therefore, some
preparation may be necessary unless the sample particle size is smal enough to be placed in a
sample cup (soils, slurries, liquids, etc.).
For mobile instruments, sample preparation is part of the analytical schedule and includes
sieving and pulverizing. A CLP level of quality control is used and data are typically processed
through a computer for conversion to nig/kg concentration units. Fundamental parameter
computer models are commonly used. A typical detection limit will range from 5 to 30 mg/kg,
depending on the sample matrix. Sample preparation may include making pressed powder
briquettes for analysis, but does not typically extend to fusing or dissolution. If these more
aggressive techniques are is required to achieve enforcement quality data, commercial
laboratories are better equipped to prepare and analyze the samples.
E.4.3 Interferences
The overlap of fluorescence peaks must be corrected for in both screening and quantitative
XRF analytical work. This effect is responsible for more errors in reporting analytical results
than all the other effects combined. Comparing the peak energy levels of the element of
interest with other peaks for the same or nearly the same energy level is a trivial but extremely
important aspect of using ttie XRF for the analytical determination of any element.
One of the most commonly encountered peak overlaps is that between the k-alpha peak for
arsenic (10.5 keV) with the l-alpha peak of lead (also 10.5 keV). The overlapping peaks for
both elements are the peaks contributing the highest primary fluorescence. If both arsenic and
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Appendix E: X-Ray Fluorescence E-5
lead are present in variably high concentrations at a site, the k-beta peak for arsenic (11.8 keV)
and the l-beta peak for lead (1Z6 keV) are used or the overlap peak is separated by
mathematically subtracting the lead contribution to the overlapped peak intensity. The arsenic
k-beta peak has only about 15 percent of the k-alpha peak intensity. The lead l-beta peak has
about two-thirds of the l-alpha peak. Therefore, even though the l-level peaks are lower in
intensity than that of k-level peaks, the detection limit for lead is less affected by the lower
energy peak than the arsenic. Other elements will involve peak overlap and can usually be
handled in a similar fashion.
£.4.4 Sample Variance Calibration
Sample preparation and particle size variance are major potential sources of error. If enough of
'the original suite of calibration samples has been collected, they are the preferred suite for
determining potential sources of error in sample preparation. If volatile elements are involved
(or mercury and arsenic to a lesser extent) sample drying should be performed at approximately
85 degrees Celsius or less). Air drying versus any other method of drying should be
investigated. If samples are to be split, stored for long periods of time, or transported from one
point to another, they should be homogenized before any other preparatbn procedure.
Complete mixing is imperative if a representative sample is to be prepared or analyzed.
Particle size variance is a two part problem. The first part concerns the field particle size that
potentially contains most of the elements of concern. The second concerns the pulverized
particle size. To determine the field particle size distribution, a suite of approximately 10
samples should be selected that cover the media, elements, and concentration ranges of a
primary metal of concern. Each of the samples should be wet sieved through a minimum of
three sieve sizes. For example, 8, 80, and 200 mesh sieves could be selected. A sample of
the unsieved material (with root mat, pebbles, and extraneous material removed) and each size
fraction is pulverized using the design protocol for pulverization. A split should be analyzed by
both the XRF and a CLP laboratory (using the hydrofluoric acid digestion method for total
metals). In some instances, sieving is preferable to pulverizing.
Particle size is one of the operator-controlled heterogeneity effects that is the most difficult to
deal with without resorting to fusbn or dissolution, both of which are time-consuming laboratory
procedures. Particle size effects are minimized by using a rigidly consistent procedure for both
sample preparation (drying, disaggregating, pulverizing, etc.) and peltetizing a constant volume
of sample. In most instances, pelletizing is necessary for defensible quantitative chemical
analyses. Liquids and properly prepared soils are potential exceptions. Site-specific samples
should be used for the determination of potential particle size effects.
E.4.5 Counting Time
There are two methods of controlling the coefficient of variation or relative percent difference
(RPD) of the analytical results generated by an XRF instrument: fixed count time or fixed count.
Most operators of XRF instruments use a fixed counting time instead of a fixed count because
fixed count may require very long counting times. The fixed count time allows a known RPD to
be calculated and sample turn-around time to be managed. The statistical error is equal to the
inverse of the square root of the total counts. For example, a total count of 1,000 would
produce a relative standard deviation of approximately 3 percent; 100 counts, 10 percent, and
10,000 counts, 1 percent
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E-6 Appendix E: X-Ray Fluorescence
X-ray tubes, with their higher x-ray flux can produce much higher counts than radioisotope
sources, and therefore, the detection limit, precision, and accuracy of instruments equipped
with these sources are, accordingly, comparably higher. Typically, 200 second counting times
are used for enforcement analysis using mobile instruments. On the other hand, screening
analysis using field portable instruments rarely uses counting-times of more than 100 seconds
to make effective use of field time. In addition to the other factors described in this section, the
counting time is one of the major reasons for differences in the quality of analytical data.
E.5 Quality Control
Exceptionally high expectations and indiscriminate use of the instruments outside the design
limits has sometimes led to discouragement in the application of field-portable XRF
instruments. Litigation-defensible quantisation limits are possible for selected elements using
properly applied field-portable instruments. Although a particularly low detection limit may not
be achievable in some cases, the instrumentation will usually determine hot spot areas,
document that representative sampling has been accomplished, and determine that an action-
level for a particular element has been reached in real time at the bcation.
Confirmatory analyses are performed by a CLP or comparable fixed analytical laboratory. A
comparable metals analysis would require the addition of hydrofluoric acid to the normal CLP
digestion. Typically, there are no differences between the methods for most metals but some
metals (for example, chromium) can occur as a refractory phase that is fully digested by the
normal CLP analysis.
Commercial laboratories are an integral part of the use of any of the sampling instruments. The
calibration and verification of analytical data generated by the use of the XRF instruments
depend on laboratory determination of the same elements. Samples sent to the laboratory for
these purposes must be the same samples analyzed by the XRF. Sample splits are acceptable
but duplicate samples should not be used for these purposes without the support of splits.
Homogenization at the laboratory is even more important than for the XRF because a smaller
sample is typically used at the laboratory than for the XRF sample. A total digestion of the
sample is necessary, Involving hydrofluoric acid in the digestion process. EMSL has an
excellent protocol for the preparation of samples for both XRF and specifications for the
laboratory. The laboratory should also analyze a subset of approximately 20 samples covering
the range of elemental concentrations of concern to determine if a difference exists between
normal CLP total metals analysis and hydrofluoric acid digested total metals.
E.6 Examples of Site Projects Using XRF
The total extent of XRF application to abandoned mine sites is undoubtedly larger than the
published accounts of such applications. Documented use of field-portable XRF instruments
start in 1985 with the Smuggler Mountain Site near Aspen, Colorado.5 The instrument was
used to determine action-level boundaries of 1,000 mg/kg lead and 10 mg/kg cadmium in soils
and mine waste. The same site was used for the evaluation of a prototype field-portable XRF
1 Memitz. S.. Olsen. R.. and Staible, T., 1985. Use of Portable X-Ray Analyzer and Geostatistical Methods to Detect and
Evaluate Hazardous Materials in Mine/Mill Tailings: Proc. Natl. Ccnf. on Management of Uncontrolled Hazardous Waste Sites,
Washington, DC. pp. 107-111.
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Appendix E: X-Ray Fluorescence E-7
instrument specifically for hazardous waste screening6. Field-portable instruments have also
been used at the California Gulch Site, Leadville, Colorado; Silver Bow Creek and other sites
near Butte, Montana; Bunker Hill Site, near Kellogg, ldiho;,and the Cherokee County Site, Tri-
State Mining District, Kansas for screening purposes during nature and extent RI/FSs.
A field-portable instrument has been used to screen a large area (21 square miles) to select
large, homogeneous volumes of heavily contaminated soils for treatability studies and for Site
Comparison Samples at the Bunker Hill Site.7 Portability and "real-time" basis data were
necessary prerequisites.
A mobile XRF instrument was used for multi-element analysis of lead, arsenic, chromium, and
copper in soils.8 Detection limits with the x-ray-tube-source and Si(Li) detector were as low as
10 mg/kg. The data were used to map the extent of contamination within a superfund site.
Detection limits for field-portable instruments are not low enough to determine cadmium
concentrations as low as 10 mg/kg in some areas/matrices, but zinc was found to be a good
surrogate indicator element for cadmium in Cherokee County, Kansas. Unlike anthropogenic
organic solvents that can occur as discrete species (with degradation even organics have
multiple compounds), inorganics, particularly metals, share interrelated characteristics of
migration that allow detection through other associated elements that occur at higher,
detectable concentrations.
- Raab, G.A., Cardenas, D., Simon, S.J., and Eccles, L.A, 1987. Evaluation of a Prototype Field-Portable X-Ray Fluorescence
System for Hazardous Waste Screening: EMSL, EPA 600/4-87/021, U.S. Envronmental Protection Agency, Washington, DC, 33 p.
7 Barich, III, J.J., Jones, R.R., Raab. G.A., and Pasmore. J.R., 1988, The Application of X-Ray Fluorescence Technology in the
Creation of Site Comparison Samples and in the Design of Hazardous Waste Treatment Studies: First Intl. Symposium, Field
Screening Methods for Hazardous Waste Site Investigations, EMSL, Las Vegas. NV, pp. 75-80.
". Perlis, R.. and Chapin, M., 1988. Low Level XRF Screening Analysisof Hazardous Waste Sites: First Intl. Symposium, Field
Screening Methods for Hazardous Waste Site Investigations. EMSL. Las Vegas, NV, p. 81-94.
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E-8 Appendix E: X-Ray Fluorescence
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Appendix F
Risk Assessment Scoping, Problem Formulation, and
Additional Risk Assessment Guidance
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
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A,ppend\x F: Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
' Guidance
Table of Contents
F.1 The Ecological Risk Assessment in the RI/FS F1
F.2 Relationship to Overall Remedial Investigation/Feasibility Study (RI/FS) Process F2
F.3 General Principles F6
F.4 RI/FS Scoping and Ecological Problem Formulation F6
F.5 Evaluate Existing Data and Visit the Site F9
F.6 Develop Conceptual Site Model F16
F.7 Identify Initial Project/Operable Unit and Remedial Action Objectives F22
F.8 Initiate Potential Federal/State ARARs Identification F25
F:9 Identify Initial Data Quality Objectives (DQOs) F26
F.10 Prepare Statement of Work for the Site Characterization Phase F27
F.11 Ecological Risk Assessment Guidance F35
F.12 Objectives and Rationale F35
F.13 Exposure Assessment F37
F.14 Ecological Effects Assessment •. , F41
F.15 Risk Characterization F46
F.16 Is Additional Assessment Necessary? F49
F.16.1 Rationale F49
F.16.2 Factors to Consider F49
F.16.3 Consultation with the BTAG F50
Glossary: F52
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
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Appendix F
Risk Assessment Scoping, Problem Formulation, and
Additional Risk Assessment Guidance •
F.1 The Ecological Risk Assessment in the RI/FS
EPA defines ecological risk assessment as "a process that evaluates the likelihood that adverse
ecological effects may occur or are occurring as a result of exposure to one or more
stressors."1 Ecological risk assessments in Superfund can be divided into three main phases
as follows (see Highlight F-1):
Problem Formulation - establishes the goals, breadth, and focus of the ecological
risk assessment. This phase includes qualitative evaluation of contaminant release,
migration, and fate; identification of contaminants of concern, receptors, exposure
pathways, and known ecological effects of the contaminants; identification of
assessment and measurement endpoints (see section F.4 of this appendix for a
definition of assessment and measurement endpoints) for further study; and
development of exposure scenarios.
Analysis - technically evaluates data on the potential exposure and effects of the
contaminants.
Characterization of Exposure - evaluates the interaction of the contaminant
with ecological receptors. This step includes contaminant characterization
(quantifying release, migration, and fate); ecosystem characterization
(characterizing exposure pathways and receptors); and development of an
exposure profile that quantifies the magnitude and spatial and temporal
distributions of exposure for the scenarios developed during problem
formulation (measuring or estimating exposure concentrations).
Characterization of Ecological Effects - analysis of the relationship
between the contaminant and the assessment and measurement endpoints
identified during problem formulation. This step may include literature
reviews, field studies, and toxicity tests to quantify the contaminant-response
relationship and to evaluate evidence for causality.
Risk Characterization - evaluates the likelihood of adverse ecological effects or
impacts occurring as a result of exposure to a contaminant; analyzes and
summarizes uncertainties; and presents weight-of-evidence discussion. This phase
includes risk estimation, risk description, and discussion between the risk assessor
and the risk manager allowing full and clear presentation of the results to the risk
manager.
Although the elements of exposure characterization and of ecological effects characterization
are most pronounced in the analysis phase, aspects of these characterizations are considered
also during problem formulation. This is illustrated in Highlight F-1 by the arrows flowing from
the problem formulation phase to the analysis phase.
: Environments! Protection Agency (EPA). 1997. Process for designing and Conducting Ecofogical Risk Assessments .
EPA/540-R-97/006. June 5. 1997.
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F-2 Appendix F: Risk Assessment Scoping, Problem Formulation,, and Additional Risk
Assessment Guidance
F.2 Relationship to Overall Remedial Investigation/Feasibility Study (RI/FS) Process
The ecological problem formulation step described above occurs during the scoping phase of
the RI/FS. The ecological assessment described in this appendix occurs during site
characterization. HighBght F-2 illustrates the overall RI/FS process and Highlight F-3 provides
an overview of the ecological assessment process at Superfund sites.
Many mining waste sites are divided into different operable units to address different areas or
sources, and RI/FS investigations for each may proceed in a phased manner. The eight-step
process for logical assessments at Superfund sites is described in Process for Designing and
Conducting Ecological Risk Assessments2. More details of the process are described below.
Scoping and ecological problem formulation. RI/FS scoping consists of the components
listed in Highlight F-4. The scoping step includes both human health and ecological concerns,
and coordination is needed among the scoping team members. The outcome of the ecological
problem formulation is a conceptual model of the site. Components of this conceptual site
model, potential ARARs, data quality objectives, and remedial action objectives are likely to
differ for the human health and ecological assessments; therefore, these need to be integrated
throughout scoping. In particular, when identifying operable units and response scenarios, both
sets of concerns must be addressed as thoroughly as possible.
Phased approach to site characterization. For most sites, the project plans for site
characterization should incorporate a phased approach to the ecological assessment with
expert review at each phase. The data or observations from one phase can be used to
determine the most appropriate studies for the next phase. Thus, a goal of the scoping phase
of the assessment is to establish detailed project plans for the first phase of an ecological
assessment. If the results of the first phase so indicate, an additional ecological assessment
may be conducted during the site characterization phase.
Scoping the ecological assessment. Highlight F-5 summarizes the steps in scoping a
remedial investigation. It shows that a primary objective of scoping is to prepare project plans
for the RI/FS, including a work plan (WP), sampling and analysis plan (SAP), and field sampling
plan (FSP)for site characterization, (i.e., determine the data required to characterize both
human health and ecological threats). The RPM is responsible for a scope or statement of
work (SOW). The contractor or other group (e.g., the Potentially Responsible Party (PRP))
performing the field assessment is responsible for project plans that address the elements of
the SOW. Highlight F-6 illustrates the elements of these plans.
Site characterization ecological risk assessment. The three primary goals of the site
characterization phase are:
To conduct a field investigation to define the nature and extent of contamination
(waste types, concentrations, distributions);
To conduct the baseline risk assessment to determine if a site poses a current or
potential threat to the environment; and
To help determine remediation goals for site contaminants.
Followrig the ecological risk assessment, the RPM evaluates whether the data collected are
sufficient to make decisions concerning remedial alternatives and cleanup goals orwhether
additional ecological information is needed.
'U.S. Environmental ProtecSon Agency, (EPA). 1997. Process fordesgining and Conducting Ecological Risk Assessments.
EPA/540-R-97-006. June 5. 1997.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
F-3
Highlight F-1
Ecological Risk Assessment Framework
Integrate Available Infbmatiofl
Ecosystem
Potentially at
RisK
PROBLEM
FORMULAT10
Planning
(Risk Assessor/
RisKManager
Dialogue)
Characterization of Ecological Eftects
Characterization of Expsosure
Measures of
Ecosystem and
Receptor
cnaraaeristics
Ecological Response
Analysis
£ Exposure ^
Profile
RISK
CHARACTERIZATION
Communicating Results
to me Risk Manager
Source: EnuiranmemalProteciioiiAgency(EPA)l998. Guidelines for Ecological RisK Assessment EPWSSCHR-9SWOSF.
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F-4 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Highlight F-2
Remedial Investigation/Feasibility Study Process
SCOPING OF ThERI/FS
Collect and analyze existing data
Identify initial project/operable
unit, likely responses scenarios,
and remedial action objectives
Initiate Federal/State ARAR
identification
Identify initial Data Quality
Objectives (DQOs)
Prepare project plans
Prepare conceptual model
REMEDIAL INVESTIGATION
SITE CHARACTERIZATION
Conduct field investigations
Define nature and extent of
contamination (waste types,
concentrations, distributions)
Identify Federa/State chemical-
and location-specific ARARs
Conduct baseline risk
assessment
TREATABILITY
INVESTIGATIONS
Perform bench or pilot treatability
tests, as necessary
FEASIBILITY
STUDY
DEVELOPMENT AND
SCREENING OF ALTERNATIVES
Identify potential treatment
technologies and containment/
disposal requirements for residuals
or untreated waste
Screen technologies
Assemble technologies into
alternatives
Screen alternatives as necessary
to reduce number subject to
detailed analysis
Preserve an appropriate range of
options
Identify action-specific ARARs
DETAILED ANALYSIS
OF ALTERNATIVES
Further refine alternatives
as necessary
Analyze altenartives against
the nine criteria
Compare alternatives
against each other
TO:
REMEDY SELECTION
RECORD OF DECISION
REMEDIAL DESIGN
REMEDIAL ACTION
Source: Adapted from Environmental Protection Agency, 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies Under
CERCLA. Office of Emergency and Remedial Response, Washington, D,C. OSIAJER Directive No. 9355.3-01.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-5
Assessment Guidance
Highlight F-3
Ecological Risk Assessment Process for Superfund
.22
x
111
.
£ £.
o
O
o
O)
"o
O
o
Q
STEP1: SCREENING LEVEL
• Site Visit
• Problem Formulation
• Toxicity Evaluation
STEP 2: SCREENING LEVEL
• Exposure Estimate
• Risk Calculation
STEP 3: PROBLEM FORMULATION
Toxicity Evaluation
Assessment
Endpoints
Conceptual Model
Exposure Pathways
Questions/Hypotheses
STEP 4: STUDY DESIGN AND DQO PROCESS
• Lines of Evidence
• Measurement Endpoints
Work Plan and Sampling and Analysis Plan
STEP 5: VERIFICATION OF FIELD
SAMPLING DESIGN
STEP 6: SIGHT INVESTIGATION AND
DATA ANALYSIS
STEP 7: RISK CHARACTERIZATION
STEP 8: RISK MANAGEMENT
RiskAssessor
and Risk Manager
Agreement
I
SMDP
SMDP
SMDP
SMDP
[SMDP]
SMDP
Source: Environmental Protection Agency (EPA) 1997
EPAS40-R-97-006
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F-6 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Highlight F-4:
Components of Scoping an RI/FS
Evaluate existing data
Develop conceptual site model
Identify initial project/operable unit, likely response scenarios, and remedial action
objectives
Initiate potential federal/state ARARs identification
identify initial data quality objectives (DQOs)
Prepare statement of work and project plans for the site characterization phase of study
F.3 General Principles
The following three principles can serve as useful guidelines when planning and conducting
ecological risk assessments at Superfund mining sites:
An ecological risk assessment usually requires data in addition to that obtained for
a human health risk assessment. While much of the data obtained for a human
health risk assessment is useful in an ecological risk assessment, additional
information usually is required (e.g., a description of the surrounding habitats and
species of concern, additional chemical sampling locations).
Criteria, standards, or other measures for the protection of human health and
welfare are not always protective of ecological systems. Many ecological receptors
are more sensitive than humans to some chemicals. Moreover, a given
environmental concentration of a chemical may result in a greater level of exposure
for an ecological receptor than for a human.
A detailed ecological risk assessment during site characterization will not be
necessary or appropriate for every site. The level of detail in an ecological risk
assessment should be appropriate to the level of information required to make risk
management decisions. A purpose of the ecological assessment is to. determine
whether additional site investigations will be required before risk management
decisions can be made at a particular site.
F.4 RI/FS Scoping and Ecological Problem Formulation
Highlight F-5 shows the steps involved in scoping the remedial investigation. The first step is to
collect and evaluate existing data in order to develop a conceptual model of the site and to
identify data gaps that will prevent effective formulation of study plans. Highlight F-7 provides a
list of useful data sources. For ecological assessments, a site walk-through with a trained
ecologist/biologist should be performed. It may be determined at this time that a limited field
investigation is required to fully scope the Rl. If this is the case, a field 'sampling plan needs to
be formulated and executed.
After collecting data to scope the Rl, the assessment team should identify chemical- and
location-specific ARARs, preliminary remedial action alternatives, preliminary action-specific
ARARs, data quality objectives, and data needs for evaluating alternative remedial strategies.
Then the assessors can develop sampling strategies, required analytic support, and data
analysis methods for the Rl site characterization.
-------
Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-T
Assessment Guidance
Highlight F-5
Steps in Scoping a Remedial investigation
Collect/Evaluate Existing Data to:
• Develop Conceptual Site Model
• Identify Data Needs
Initiate Discussion of Chemical-
and Location- Specific ARARs
I
Identify Data Quality Objectives:
• Site Characterization
• Risks Assessment
• Treatability Studies
Execute Limited
Studies
Yes
Is Limited Field
Investigation Needed to Plan
Specific Project®?
Plan Limited
Studies
Identify Preliminary Remedial Action
Alternatives:
• Identify Potential Technologies
• Begin Review of Technologies
• Identify Likely Alternatives
• Identify Need for Treatebility Studies
Begin Preliminary Identification
of Action-Specific ARARs
Identify Data Needs for
Evaluation of Alternatives
Develop Sampling Strategies and
Analytical Support, and Health and
Safely Protocols
Describe Data Analysis Methods and
Define Rl and FS Tasks
Prepare RKFS Work Plan
Prepare HSP
Prepare SAP
Source: Adapted mm Environmental Protection Agency (EPA) 1988. Guidance for Conducting Remedial muesligalions
Studies underCERCLA. Office of Emergency and Remedial Response, wiasnington, D.C. OSUUER Directive No. 93SS.S-01.
arm Feasibility
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F-8 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Highlight F-6:
Elements of Project Plans
Elements of a Work Plan (WP)
A comprehensive description of the
work to be performed, the information
needed for each task, the information
to be produced during and after each
task, and a description of work
products submitted to the RPM;
The methods that will be used during
each activity;
A schedule for completing activities;
The rational for performing or not per-
forming an activity;
A background summary and history of
site;
A site conceptual model;
Identification of preliminary site objec-
tives including preliminary remediation
goals;
The need for additional data when fu-
ture site unknowns are identified;
The manner of identifying federal and
state ARARs;
An identification of preliminary alterna-
tives and RI/FS guidance; and
A plan for meeting treatability study
requirements.
Elements of the Sampling and Analysis
Plan (SAP)
Sampling procedures;
Sample custody procedures;
Analytical procedures;
Data reduction, data validation, and
data reporting;
Personnel qualifications;
The qualifications of each laboratory to
conduct work; and
The use of internal controls, such as
unannounced site, performance, and
system audits.
Elements of the Field Sampling Plans
(FSP)
The sampling objectives;
Sample locations;
Sampling frequency and when to
sample;
Sampling equipment and procedures;
Program for sample handling and
analysis.
Note: Project Plans also include a health
and safety plan (HSP) for the personnel
conducting the sampling.
Source: Adapted from Environmental Prelection Agency (EPA). 1991. Guidance on Oversight ofPotentally Resonsble Party Remedial Investigations and
FttsibiHy Studies. Volume 1. Office of Solid Waste and Emergency Response. Washington, DC. OSWER Directive 9835.1 (c). EPA/540/3-91/010a.
At enforcement lead sites, it is crucial to compile documentation for cost recovery and to make
sure that natural resources trustees have been notified of site activities so that they can
conduct their investigations.
EPA has published guidance to help develop a scope of work for Ecological Assessments.3
This guidance provides an overview of the role of the BTAG, points to consider in developing a
scope of work, elements of an ecological assessment scope of work, ensuring contractor
capability to do the work, and a sample work scope. The remainder of this sectbn provides
additional details and sources of information to supplement the existing guidance, emphasizing
elements that are likely to be important for mining sites.
' Environments! Protection Agency (EPA> 1992b. Developing a Work Scope for Ecological Assessments. ECO Update,
Intermittent Bulletin. Volume 1, Number4. Office of Emergency and Remedial Response, Hazardous Site Evaluation Division,
Washington. DC. Publication 9345.0-09.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
F-9
F.5 Evaluate Existing Data and Visit the Site
The first step of scoping for the Rl is evaluating all existing data for the site. As scoping begins
for the Rl, some data already should be available from previous site studies, studies from
similar sites, available aerial photographs, and other sources. Initial site data from the
Preliminary Assessment (PA), Site Investigation (SI), Hazard Ranking System (MRS) Scoring
Package, and supporting materials included in the docket established as part of the NPL listing
process should be obtained. Existing RI/FS studies from similar types of mining waste sites
also may be helpful in identifying background information that can help to devebp hypotheses
about potential problems at the site.. During this process, it is critical for the ecological
assessment team to work with those'conducting the scoping study from the human health
perspective. Ten tasks are outlined below.
Task 1: Contact BTAG, Appropriate Agencies and Experts, and Natural Resource
Trustees
Contact the Biological Technical Assistance Group (BTAG). The role of BTAGs in
ecological assessments at Superfund sites is described in ECO Update Volume 1, Numbers 14
and 45. If a BTAG or equivalent advisory group exists in the Region (or is otherwise
accessible), begin the process of involving group members in the scoping ecological
assessment as early as possible. The BTAG can screen the initial site data (e.g., PA, SI, HRS
data) to recommend the nature and extent of an ecological assessment that is likely to be
needed at the site and to identify the most relevant exposure pathways for further study. BTAG
members also can be extremely helpful throughout the ecological assessment, including:
Assisting the RPM to scope the ecological assessment effort;
Reviewing the conclusions of the scoping phase;
Recommending study objectives, field and laboratory protocols, QA/QC require-
ments, and other elements of the Rl SOW; and
Reviewing draft RI/FS work plans for site characterization.
In some Regions, RPMs present a brief oral description of a site and its history to the BTAG to
begin the consultation process. Eco Update Volume 1, Number 5s discusses this initial briefing.
Contact appropriate state or local fish and game agencies. Other agencies may have
statutory responsibility for involvement in management of the resource(s) of concern (e.g., state
Fish and Game Departments). Personnel from these agencies who are familiar with the area
should be contacted to determine whether any adverse ecological impacts have been reported
that might be attributable to contaminants from the site. Types of impacts that may be
expected include fish kills (particularly following storms), reduced or absent fish or wildlife
populations, and reduced abundance of particular plant species. Note that these types of
impacts may or may not be site-related. It also will be important to determine the state-
designated uses of any potentially affected surface waters, whether the surface water quality
meets the requirements for the designated use, and if not, the possible causes of use
impairment.
1 Environmental Protection Agency (EPA^ 1991b. The Role of BTAGs in Ecological Assessment. ECO Update, Intermittent
Bulletin, Volume 1, Number 1. Office of Emergency and Remedial Response. Hazardous Site Evaluation Division, Washington,
DC. Publication 9345.0-05I.
' Op. Cit. 3.
- Environmental Protection Agency (EPA): 1992. Briefing the BTAG: Initial Description of Setting, History, and Ecology ofa
Site. ECO Update, Intermittent Bulletin, Vdume 1. Numbers. Office of Emergency and Remedial Response. Hazardous Site
Evaluation Division, Washington, DC. Publication 9345.0.051
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F-10 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Highlight F-7:
Useful Sources of Existing Data
Federal Sources of Existing
Data
State Sources of Existing
Data
Local Sources of Existing
Data
Preliminary Assess-
ment/Site Inspection
Hazardous Ranking
Scoring (MRS)
documentation
PRP search — Section
104(e) letters — waste-in
list — data requests to the
PRP
Records on removals and
disposal practices
Permits for discharges —
Toxic Releases Inventory
System (TRIS)
National Pollutant
Discharge Elimination
System (NPDES)
Prior Contract Laboratory
Program (CLP) work
RCRA manifests,
notifications, and permit
applications and Section
3007 information requests
EPA databases (see
Appendix A of source)
EPA-equivalent agency
Planning board
Geological Survey
• Fish and Wildlife Service
Historic Preservation
Office
Natural Resource
Department
Natural Heritage
Program
Department of
Conservation
Public library
Chamber of Commerce
Audubon Society
Planning board
Town/city hall or court
house
Water authority
Sewage treatment facility
Previous site employees/
management
Residents near site
Universities (information
on local areas)
Historical societies
Newspaper files
Source: Adapted from Environmental Protection Agency (EPA). 1991. Guidance on Oversght of Potentally Response/a Party Remedial Investgations and
Fttittiitly Studies. Volume 1. Office of SolidWaste and Emergency Response,Washington, DC. OSWSR Directive 9835.1 (c). £PA/540A3-91/010a.
Contact CERCLA natural resource trustees. The NCP outlines formal notification and
coordination requirements for EPA and the CERCLA natural resource trustees throughout the
RI/FS process. These requirements and recommendations for additional involvement of the
natural resource trustees are described in ECO Update Volume 1, Number 37. In general, it is
important to notify natural resource trustees early and often and always to notify the U.S. Fish
and Wildlife Service (FWS; representing the Department of the Interior (DOI)) and the National
Oceanic and Atmospheric Administration (NOAA; representing the Department of Commerce).
It also may be beneficial to invite trustees' representatives to accompany the assessment team
on site visits. Appropriate personnel from FWS, NOAA, and other natural resource trustees can
be extremely helpful in identifying and describing signs of exposure or impacts or noting the
absence of species expected to be present. In many Regions, natural resource trustee
representatives are members of the BTAG.
' Environmental Protection Agency (EPA). 1992f. The Role of Natural Resource Trustees in the Superfund Process. ECO
Update. Intermittent Bulletin, Volume 1, Numbers. Office of Emergency and Remedial Response, Hazardous Site Evaluation
Division, Washington. DC. Publication 9345.0-09.
-------
Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-11
Assessment Guidance
In accordance with the NCP §300.615(c)(1) and through Memoranda of Understanding
between EPA and both DOl and NOAA, the RPM can request a representative of one of the
natural resource trustees to conduct a Preliminary Natural Resource Survey (PNRS) or another
form of preliminary site survey. A PNRS consists of a site survey and a brief report identifying
the natural resources, habitat types, endangered or threatened species, and any potential
impacts or injuries to trust resources. The PNRS may be funded by EPA and conducted at any
stage of the remedial process, from pre-listing to pre-Record of Decision (ROD). If the PNRS is
conducted before Rl scoping, it may provide information useful for sampling design and other
aspects of the Rl ecological assessment.
Other agencies that represent natural resource trustees at many mining sites include the states
and the Bureau of Land Management (BLM). Given the large size of many mining sites, poten-
tially affecting large proportions of entire watersheds, it can be helpful to establish a cooperative
group to coordinate actions on a watershed basis. The group might be comprised of more than
one EPA Office (e.g., Superfund, Office of Water) and appropriate state and other federal
agencies (see Highlight F-8).
Task 2: Identify the ecological risk assessment team
Once the principal attributes of the site that may need evaluation have been identified, an
ecological assessment team can be identified. Determine which types of technical expertise
are required to evaluate the site. The team may be comprised of EPA Superfund staff and
include representatives from NOAA, the FWS, or state agencies (see Highlight F-9). The
BTAG may be able to recommend appropriate individuals for the team.
Task 3: Map the site
Mapping attributes of the site will assist in formulating a conceptual model for the site. Obtain
all available background information on the site and its setting and begin to prepare a map.
Specific objectives in this step are to identify and map:
(a) Sources of contaminants and areas of suspected contamination (e.g., deposition
areas);
(b) Likely contaminant migration pathways; and
(c) Location and extent of on-site and nearby aquatic, wetland, and terrestrial
habitats.
The first two steps (a and b) should be coordinated with the human health assessment team
when developing the conceptual site model (section H.6). The final step (c) will be the
responsibility of the ecological risk assessment team. For recently listed sites, much of this
information should be described in the HRS materials, although additional investigation may be
required. The initial map should be consulted or updated in all of the following steps.
Task 4: Develop a history of site operations
In conjunction with the human.health assessors, compile information on when mining began,
duration of the mining activities, volumes of materials handled, and technologies used in
excavation, beneficiation, and refining. This information can indicate what types and how much
hazardous waste is present, where it is located on site, and where it has migrated off site.
Historical information helps in identifying locations of past activities at which hazardous wastes
are likely to be found. Site history should be described in some detail in the HRS materials,
. although additional investigations may be required.
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F-12 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Highlight F-8:
Example of a Multi-Agency Task Force for a Superfund Mining Site
Water quality of the Upper Arkansas RiverBasin has been impacted duetomining, benefeiatfon,
post-m ill smelting, farming, and urbanization overthe past century. Water qualify impacts in the Arkansas
drainage have been especially acute in the Leadville mining district, including the California Gulch
Superfund site, the Leadville mine drainage tunneldischarge.and mine discharges from the Cripple Creek
mining district, the Chalk Creek mining district and miscellaneous mines in the watershed. The primary
threat to aquatic life in the Arkansas and its major tributaries is the inflow of dissolved metals (i.e., zinc,
manganese, cadmium, lead, copper, iron, and nickel) at levels exceeding the state water quality
standards. The majorityof theproblemcreeksare acidic (pH between 2.5 and 3.0). In recent years, toxic
metal pollufion of Chalk Creek was noted when over 800,000 trout fingerlings died in the spring of 1985
and spring of 1986 after placement in the Colorado Division of W ildlife's Chalk Creek Fish Rearing Unit.
Given the large number of sources impacting the Arkansas drainage, a multi-agency demonstra-
tion project has been established to reduce, and possibly eliminate, the existing mining-related nonpoint
sources of pollution in Chalk Creek so that the salmonid (i.e., trout) fishery can be returned. EPA has
provided grants to the State of Colorado Water Quality Control Division (CW QCD), Depa rtmen t of Hea Ith
and the State of Colorado Department of Natural Resources, Mine Land Reclamation Division (MLRD)
to conduct the Chalk Creek - St. Elmo Nonpoint Source Water Improvement Demonstration Project. At
the request of CWQCD, a Colorado NonpointSourceTask Force (CNSTF) was formed. The Task Force
is comprised of four subcommittees, including one on mining. The subcommittee on Abandoned and
Inactive Mines is comprised of agencies and individuals involved in efforts to control inactive mine
pollution of the Basin. Groups or organizations that are contributing funds or services to the Chalk Creek
demonstration project include Coors Pure Water, Cyprus Coal Company, the U.S. Bureau of Mines, the
U.S. Bureau of Reclamation, the Soil Conservation Service, and Volunteers for Outdoor Colorado tree
planting, among others.
Highlight F-9:
Ecological Risk Assessment Team
The ecological risk assessment team may include personnel from the following resources:
EPA Regional Offices
Environmental Services Division
Environmental Response Team
Water Division
EPA National Offices
Office of Research and Development
Other Federal Agencies
US Geological Survey
US Fish and Wildlife Service
US Department of Agriculture
National Oceanic and Atmospheric Administration
States
State Fish and Wildlife Service
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Appendix F-. Risk Assessment Scoping, Problem Formulation, and Additional Risk F-13
• Assessment Guidance
Task 5: Evaluate aerial and other photographs of the site
Aerial photographs are helpful to both the ecological aBiJ human health risk assessors for
several purposes:
Verifying the existence and precise location of various site features and
determining the spatial extent of waste piles and other sources;
Identifying erosipn patterns and other topographic features that can influence
contaminant migratio,n pathways and the locatbn of deposition areas;
Locating evidence of past mining operations that are not included in the historical
record (or whose existence is uncertain); and
Documenting and/or verifying the site history, if a time series of aerial
photographs dating from near the beginning of mining operations to the present
is available.
For ecological risk assessors, aerial photographs can provide additional information:
Delineating the location and extent of various on-site and nearby habitats,
although some ground-truthing (i.e., confirming designations by visiting key
locations on the ground) usually is required even at the scoping phase (see Task
7); and
Documenting vegetation loss over time and identifying sources that may have
caused the losses, if a time series of aerial photographs is available.
Task 6: Evaluate infrared aerial photographs of the site
Infrared aerial photography taken during the growing season can be useful in identifying areas
of stressed vegetation. Locating such areas may help identify contaminant sources or areas
where hazardous wastes have migrated that otherwise might be overlooked. Although this step
can be somewhat expensive (e.g., photointerpretation by a skilled expert is essential), a good
series of infrared photographs can save money in the long run by allowing one to identify and
bound areas that might require additional investigation. Some ambiguities are possible,
however, and ground-truthing usually is necessary. These photographs should not.be
considered a substitute for a site visit.
Task 7: Plan a site visit
When scoping an ecological assessment, the site and surrounding areas should be visited at
least once. Site visits allow the RPM to become familiar with the location, size, and general
condition of the site and nearby environments. Some signs of impacts can be observed via
careful examination by a trained ecologist/biofogist. To be effective, site visits require careful
planning, as described in the following paragraphs. The site visit should be coordinated with
any site visits planned for scoping the human health assessment.
Ensure that the right personnel are included in the site visits. Ensure that at least one
person who is familiar with site-specific fauna and flora takes part in all site visits. No written
guidance can replace the expertise of a trained field ecologist/biologist in identifying and
describing signs of exposure or impacts, noting the absence of species expected to be present,
-------
F-14 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
and locating appropriate reference habitats. Such an individual also may be helpful in
characterizing the overall condition of various habitats and in developing or refining specific
hypotheses to be tested. Types of individuals who may be helpful during site visits include:
Representatives of natural resource trustees (e.g., FWS, NOAA) who have
appropriate training and expertise;
Appropriate representatives of state or local wildlife, fish and game, natural
resource, or equivalent agencies; andr
Members of BTAGS (although this is not their usual role).
Prepare a list of areas to visit. Areas to visit should include all man contaminant migration
pathways as well as on-site, nearby, and reference habitats and other specific areas that may
need to be sampled. Specific areas to visit should include habitats that are:
Known to be contaminated;
Located between contaminant sources and areas known to be contaminated;
Located along known or potential contaminant migration pathways; and
Appropriate reference areas.
Reference areas. In general, an appropriate reference area is one that includes similar habi-
tats/ecosystems, yet is relatively unimpacted by contaminants from the site. There are two
approaches to identifying these areas: (1) trying to identify an area upgradient (e.g., upstream)
of the site that is otherwise similar; or (2) trying to locate a similar habitat (e.g., stream order,
surrounding vegetation, altitude) elsewhere in the same drainage basin that has not been
affected by mining activity. The first approach is preferable because the closer the reference
area to the site, the more similar to the site its ecological setting is likely to be. Care must be
taken to establish a reference area sufficiently far upgradient that it is unlikely that site
contaminants have reached the reference area by any means. Sometimes, however, the
upgradient area is significantly different from the area potentially affected by the site (e.g., lower
order streams, different stream bottom type, different cover and temperature). If this is the
case, the second approach may be preferable. A trained biologist is needed to identify
appropriate reference areas or to design alternative studies in the absence of an adequate
reference area.
Determine when to visit each area. Timing can be critical for characterizing the overall
condition or quality of a given environment. Many plants and animals are markedly seasonal in
occurrence or abundance; snow cover and other seasonal events may interfere with observa-
tions. During a given season, activity patterns of most animals exhibit diel (i.e., daily) variability
(e.g., owls and most mammals are active largely at night, birds sing largely in the early
morning, dragonflies are active primarily during the warmer parts of the day). For each area,
determine which areas to visit in early morning, mid-day, late afternoon, and/or night.
Task 8: Conduct the site visit
Visit reference areas and habitats first. It may be helpful to visit all known or potential
reference environments prior to conducting site visits in order to characterize or become familiar
with typical conditions in the area.
Visit all study areas. Visits to each area should include walks down streams or rivers, along
the edge of other surface water bodies, and downwind of tailings piles, open landfills, and other
large areas of surface contamination. During these visits, the bcations of all important habitats
should be noted and any previously uncharacterized areas should be mapped.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
F-15
Document signs of potential impacts. During visits to each area, a trained ecologist/bblogist.
may be able to detect signs of potential impacts and, note the location of these observations on
the site map. When looking for signs of potential impacts, focus first on those portions of each
area that are most likely to be contaminated (e.g., the most likely point at which contaminants
would enter a surface water body or a wetland, the portion of an environment closest to the
source, deposition areas such as river bends where sediments are likely to accumulate).
Subtle indicators of potential impacts (e.g., changes in community structure or species diversity)
may not be evident during relatively brief site visits. However, unusual colors or odors or the
absence of certain characteristic features of healthy environments can be noted during a site
visit and provide evidence of potentiial-impacts. For example, lack of dragonflies or other
insects typically found at or near the edges of rivers and streams or lack of insects typically
associated with leaf litter may indicate ecological impacts. In shalbw streams, fish, crayfish,
snails, and aquatic insects often can be seen if present. If definitive documentation of reduced
abundance or diversity of species is needed, however, it would be necessary to include a
systematic biological survey in the Rl.
Task 9: Modify maps and hypotheses
Subsequent steps in scoping will be facilitated by a scale map that identifies the following:
Location and type of sources (e.g., waste rock piles, taiings piles, tunnel
entrances);
Hazardous wastes and substances known or suspected to be present in each
source;
Potential discharge or release areas (e.g., tunnel discharge areas, groundwater
seeps);
Topographic features that would facilitate migration of contaminants from
sources to nearby habitats (e.g., drainage ditches, creeks, depressions) and
would facilitate deposition of contaminants (e.g., river bend);
Location and area! extent of known adverse impacts that might be site-related
(e.g., locatbns offish kills, areal extent of stressed vegetation).
Location of on-site and nearby habitats; and
Location of potential reference habitats.
It is important to remember that for most mining sites, the large-scale physical disturbances of
the terrain can be responsible for a large proportion of observed impacts on vegetation (e.g.,
once a hilly terrain is stripped of vegetation and top soil, native plants may not be able to
reestablish for decades). Thus, maps also should include indications of where physical
disturbance and erosion may have occurred:
At this time, hypotheses about contamination and threats may need to be refined or otherwise
modified. In certain areas, observation may confirm contamination, indicate that contamination
is unlikely, and/or identify new potential threats.
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F-16 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Task 10: Characterize the ecological setting and potential receptors
Using the results of the previous steps, it now should be possible to identify and characterize
the potentially exposed habitats on or near the site and potential species, communities, or
functions such as wetlands impacted in these habitats. This task includes several steps:
Describing and delineating the terrestrial, wetland, and aquatic habitats;
Identifying the species indicative of the healthy functioning of similar habitats
(e.g., top level carnivore, trout in cold water streams, naturally dominant
vegetation, aquatic insect larvae);
Identifying endangered or threatened species potentially on or near the site; and
Identifying other species protected under federal or state law (e.g., Migratory
Bird Treaty Act, Marine Mammal Protection Act).
If contaminants at the site are known to bioaccumulate (e.g., cadmium, mercury), it is important
to consider trophic relationships among the wildlife species so that the potential for food-chain
effects can be assessed. Descriptions of potentially affected habitats should include as much
detail as is necessary to scope the work. For example, stream aquatic communities vary
considerably depending on depth, width, flow, type of bottom, and types of vegetation in and
adjacent to ttie stream. These attributes affect both the kinds of studies required to evaluate
possible effects and the level of effort needed to conduct the studies.
F.6 Develop Conceptual Site Model
The end product of the ecological problem formulation process is a conceptual site model
(Highlight F-10). The model should identify possible contaminant sources, primary and
secondary release mechanisms, exposure pathways, and environmental receptors. The model
also should identify additional data needs and the analyses to be used. The steps for
developing a conceptual model are listed in Highlight F-10 and discussed in the remainder of
this section.
Task 1: Qualitatively evaluate contaminant release, migration, and fate
Evaluate contaminant release, migration, and fate in conjunction with the human health
assessors. Compile a list of possible contaminants and describe existing information on
contaminated media, contaminant migration, and the geographical extent of current and
potential contamination.
Identify sources that have released contaminants. Information used to support MRS scoring
may include the identity, approximate size, and location of sources known to have released
contaminants. Information obtained when developing the history of site operations might help
to identify other sources that have released contaminants.
Identify contaminant migration pathways. It is important to identify the key contaminant
migration pathways. Considerations at mining sites in particular include the following:
Runoff from and erosion of contaminated soils, tailings piles, orsurficial
materials into rivers, streams, and lakes;
Leaching of contaminants in soils and waste piles to groundwater and
subsequent discharge to surface water and wetlands;
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-17
Assessment Guidance
Collapse of tailings piles into surface waters;
Tunnel surges (e.g., from collapse of a tunnel roof that temporarily dams water
until the water pressure is sufficient to break'through the debris);
Tunnel seepage (often very acidic);
Surface water transport and redistribution of contaminated sediments;
Air transport of contaminated soils or surficial materials (e.g., flue dust from
smelter activities); and.
Bioaccumulation and bbconcentration of contaminants in food chains.
Highlight F-10:
Ecological Problem Formulation (Scoping) Conceptual Model
Qualitatively evaluate contaminant release; migration, and fate
Identify:
contaminants of ecological concern
potential ecological receptors
potential exposure pathways
known effects
Select endpoints of concern
Develop conceptual model; identify:
scope
data needs
For surface water contamination, it also is important to determine the critical conditions
affecting surface water contaminant loading (e.g., is it low flow during the winter or the spring
flush?).
Identify potential or actual areas of contamination. Delineate the spatial extent of known
contamination to the extent possible. Sampling efforts used to determine the HRS score for the
site may have identified at least some areas known to be contaminated above background
levels. For sites scored with the revised HRS, there also maybe information on existing
contamination of sensitive and other nearby habitats. Identify any habitats known to be
contaminated or located within, between, ordowngradient of areas of known contamination.
Also, identify potential deposition areas for contaminated soils and sediments (e.g., bends in
rivers) and other types of hot spots.
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F-18 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Task 2: Identify contaminants of ecological concern
EPA's ECO Update, Volume 1, Number 28 describes factors to consider in identifying contami-
nants of ecological concern. We review those factors here. From the list of possible
contaminants developed in the qualitative evaluation (Task 1), identify those contaminants that
may be of ecological concern, considering the following:
Amount of contaminant:
Environmental concentratbns in media that represent ecological
exposure pathways (i.e., soil, surface water, sediment, and biota);
Known extent of contamination in on-site and off-site media; and
Background levels, indicating contamination that cannot be attributed to
the site.
Attributes of contaminant:
Physical-chemical properties (e.g., volatility, solubility, and persistence);
Bioavailabilfty (i.e., presence in a form that can adversely affect
organisms);
Potential for bbaccumulation or bioconcentration (e.g., log K™ between 3
and 7);
Toxicity (i.e., the amount of toxicant capable of producing adverse effects
in organisms)9;
Time necessary to produce adverse effects (i.e., days, weeks, years);
and
Type of effects (e.g., lethal or sublethal responses).
Task 3: Identify potential ecological receptors
Ecological receptors include individual organisms, populations, or communities that can be
exposed to contaminants. After the fate, migration, and potential release of contaminants have
been reviewed, potential receptors can begin to be identified. Identify potentially exposed
terrestrial, wetland, and aquatic habitats on or near the site and develop lists of species known
or likely to occur in each habitat. Identified receptors should include species on or nearthe site
that are:
Endangered or threatened;
Protected under other federal or state law (e.g., the Migratory Bird Treaty Act);
Rare or unique; or
Considered indicative of the healthy functioning of the community.
The revised Hazard Ranking System (MRS) contains a list of sensitive aquatic and terrestrial
environments as shown in Highlight F-11. For NPL sites listed after March 14, 1991, all
sensitive environments within the HRS target distance limits (generally a 4-mile radius for
terrestrial environments and 15 miles downstream for aquatic environments) should be
identified in the HRS scoring package and related materials. At mining sites, however, further
distances from the site may need to be considered (e.g., entire drainage basins because of the
large quantities of waste present). The HRS scoring package also may provide some
information as to whether or not any sensitive environments are contaminated.
• Op. Cit. 2.
* One source of information on relative toxicity to aquatic organisms can be EPA's ambient water quality criteria (AWQC) for the
protection of aquatic life. See section H.14.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-19
Assessment Guidance
Sources of Information. Several sources of information can be helpful in identifying habitats
and species on or near the site:
Aerial photography and satellite imagery;
Site visits;
MRS guidance materials in Regional offices (may include catalogues, maps, or
other compilations of some types of sensitive environments);
National Wetland Inventory maps;
U.S. Geological Survey topographic maps;
Natural Resource Trustees;
State or local fish and game agencies (e.g., any history of ecological effects from
site);
Water monitoring programs for surface water quality; and
State Natural Heritage Programs.
Task 4: Identify potential exposure pathways
An exposure pathway is the link between a contaminated area and a receptor. Potential
exposure pathways for ecological receptors can be identified from the analysis of contaminant
release, migration, and fate, and from the receptors present. In evaluating exposure pathways,
consider all relevant media (i.e., surface water, sediment, soil, and biota) that are or potentially
could be contaminated. For example, organisms may be exposed by direct contact with
contaminated media or by indirect contact through the food chain. Consider all potential
receptors when identifying exposure pathways. There are several exposure pathways that
often are of concern at mining sites:
Direct contact with contaminated sediments for benthic invertebrates, bottom-
dwelling fish, fish eggs and fry, and amphibian eggs and tadpoles;
Direct contact with water column contaminants for fish;
Ingestion of contaminated, sediments by benthic invertebrates, bottom-dwelling
fish, and waterfowl;
Ingestion of contaminated soils by worms, other invertebrates, and burrowing
mammals;
Ingestion of contaminated soils and forage plants by grazing herbivores (e.g.,
deer, domestic livestock);
Ingestion of contaminated aquatic prey by piscivorous birds and mammals and
by waterfowl; and
Ingestion of contaminated small mammals by raptors and carnivorous mammals.
Task 5: Identify known effects
In contrast to other types of Superfund sites, the contaminants at mining sites typically are
limited to metals and a few other types of substances (e.g., cyanide, sulfuric acid, phosphorus).
For aquatic communities, EPA's ambient water quality criteria (AWQC) for the protection of
aquatic life can be used to identify contaminant levels in the water column below which adverse
effects on aquatic communities are unlikely to occur. It is important to remember that these
criteria are not necessarily protective of benthic aquatic communities (i.e., organisms that live in
close association with sediments). Possible contaminant effects on terrestrial mammalian
species can be identified from the toxicological literature compiled in support of criteria
developed for the protection of human health (e.g., EPA Reference Doses (RfDs)). Data on the
effects of most of these substances on other terrestrial groups (e.g., birds, amphibians) are
available in the published literature.
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F-20 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
In the event that an unusual organic or metal compound is of concern, other sources can be
consulted. For example, the AQUatic Toxicity Information REtrieval (AQUIRE) data base
contains data that can be used to evaluate the effects of contaminants on aquatic organisms.
Where appropriate, data on chemicals similar but not identical to site contaminants can help
characterize likely effects. Modeling techniques, such as Quantitative Structure Activity
Relationships (QSAR), also can be used to estimate the toxicity of untested chemicals. These
methods require specialized expertise to ensure proper interpretation of results.
The RPM also should obtain information from appropriate investigations conducted on or near
the site to help target the ecdogical.assessment toward the most relevant questions. Examples
of useful studies include:
Studies in support offish or wildlife consumption advisories issued by state or
local government agencies;
Corroborative reports of unusual events such as stressed vegetation, fish kills,
other mortality events, or absence of species expected in the habitat; and
Field or laboratory studies from previous investigations of the site (e.g.,
preliminary investigations).
Task 6: Select endpoints of concern
A critical step in selecting endpoints is deciding what effects are important to the remedial
decision-making process (i.e., assessment endpoints-) and what measurements can be used to
evaluate these effects. An assessment endpoint is any specific value to be protected, for
example, a supply of uncontaminated fish for anglers to catch, survival of an endangered
species, or maintenance of a particular population. A measurement endpoint is a quantifiable
characteristic related to an assessment endpoint, such as the chemical concentration in water
that correlates with contaminant levels of concern in fish tissues.
Ideally, measurement and assessment endpoints are the same, but this seldom is possible.
For example, one can't trap endangered species and analyze their organs for contaminants. In
this case, separate measurement endpoints are needed. Usually several measurement
endpoints must be evaluated to determine the status of an assessment endpoint. It must be
possible to link clearly the measurement endpoints to their respective assessment endpoints.
In addition, measurement endpoints should provide informatbn about the source of the effects
on the assessment endpoint. For example, it is not enough to know that eagles are not
reproducing well at a site; a substance that can cause this effect (e.g., DDT) also must be
present at the site, and the eagles must be exposed to it in someway (e.g., through
contaminated fish). In this example, the assessment endpoint is eagle population maintenance,
and the measurement endpoints are DDT residues in site soils and in fish (and perhaps facility
records showing releases).
The linkages between the endpoints are as follows: Eagle population maintenance is of
concern at the site DDT was produced there and released DDT causes reproductive failure
in eagles DDT is found in fish species that the eagles consume within their feeding areas
eagles can reasonably consume enough DDT to cause reproductive effects.
It is not uncommon to redefine measurement endpoints during the analysis phase or after the
scoping process given the heterogeneity of site habitats and the constraints of our knowledge
base. Ratbnale for any changes should be documented.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-21
Assessment Guidance
Highlight F-11:
List of Sensitive Environments in the Hazard Ranking System.5'
Critical habitat for Federal designated endangered or threatened species
Marine Sanctuary
National Park ••..,.
Designated Federal Wilderness Area
Areas identified under the Coastal Zone Management Act
Sensitive areas identified underthe National Estuary Program or Near Coastal Waters Program
Critical areas identified under the Clean Lakes Program
National Monument
National Seashore Recreational Area
National Lakeshore Recreational Area
Habitat known to be used by Federal designated or proposed endangered or threatened species
National Preserve
National or State Wildlife Refuge
Unit of Coastal Barrier Resources System
Coastal Barrier (undeveloped)
Federal land designated for protection of natural ecosystems
Administratively Proposed Federal Wilderness Area
Spawning areas critical for the maintenance of fish/shellfish species within river, lake, or coastal tidal waters
Migratory pathways and feeding areas critical for maintenance of anadromous fish species within river reaches or
areas in lakes or coastal t'rial waters in which the fish spend extended periods of time
Terrestrial areas utilized for breeding by large or dense aggregations of animals
National river reach designated as Recreational
Habitat known to be used by state designated endangered or threatened species
Habitat known to be used by species under review as to its Federal endangered or threatened status
Coastal Barrier (partially developed)
Federal designated Scenic or Wild River
State land designated for wildlife or game management
State designated Scenic or Wild River
Stage designated Natural Areas
Particular areas, relatively small in size, important to maintenance of unique biotic communities
State designated areas for protection or maintenance of aquatic life
''The categories are listed in groups from those assigned higher factor values to those assigned bwer factor values in the HRS.
See Federal Register, Vol. 55, p. 51624 for additional information regarding definitions.
Other examples of assessment endpoints established at some mining sites include the
following:
Reestablishing a self-sustaining trout (or other sport) fishery in affected surface
waters;
Revegetation to control fugitive dust and erosbn and to improve wildlife habitat;
Attainment of designated beneficial use for surface waters (although attainability
analysis can indicate use limitations for a variety of reasons unrelated to the
mining site); and
Attainment of the same level of water quality as upstream of the site.
Examples of measurement endpoints include:
Contaminant concentrations in surface water, sediments, and soils;
Contaminant concentration in fish tissues or other biota;
Toxicity of surface waters using surrogate species (e.g., fathead minnow) or
assessment species (e.g., trout fry);
Plant root and shoot elongation bioassays using site soils; and
Presence/abundance of biological indicators of stream water quality (e.g., insect
larvae).
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F-22 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Task 7: Use flow diagrams and maps to help define a conceptual model
In finaizing the conceptual model for the site, establish the following:
(1) A flow chart depicting how contaminants move from sources to receptors,
including release mechanisms, secondary sources (e.g., contaminated soil),
secondary release mechanisms (e.g., wind erosion), contaminant migration
pathways (e.g., air, surface water), receptors (e.g., aquatic community) and
routes of exposure (e..g., direct contact, food chain);
(2) A flow chart depicting how the proposed measurement endpoints can be used to
infer the status of the assessment endpoints; and
(3) A map of the site depicting contaminant sources, migration pathways, key
habitats, and potential exposure areas for receptors of concern. The map will be
particularly helpful in establishing the spatial aspects of the field sampling plan.
Flow charts and maps can facilitate discussions among members of the site assessment team
and the RPM, help identify, gaps in data or logic, and identify the field sampling needs.
Highlight F-12 provides an example of a flow chart for a conceptual model for the ecological risk
assessment.
F.7 Identify Initial Project/Operable Unit and Remedial Action Objectives
Once the existing site information has been analyzed and a conceptual model of the site
developed, the assessment team can identify the project/operable units, likely response
scenarios, and remedial action objectives. This step requires close coordination of the
ecological and human health assessment teams and is described in detail in EPA's Guidance
for Conducting Remedial Investigations and Feasibility Studies under CERCLA10. For each
contaminated medium:
Identify potential remedial action technologies;
Begin review of technobgies;
Identify likely alternatives; and
Identify need for treatability studies.
This step is particularly important for ecological concerns at mining sites, because restoration to
pristine conditions generally is not possible and options for remediation can be limited by the
magnitude and scope of the environmental contamination. The ecological assessment should
be focused within these constraints; otherwise, more effort may be expended on the
assessment than is necessary or useful.
Many of the adverse impacts of mining waste sites on terrestrial and aquatic habitats result
from non-chemical stressors. The large-scale physical disturbances associated with former
surface mining operations in particular can result in severely degraded landscapes. Once
vegetation is lost and exposed soils erode for many years, decades may be required for
reestablishment of vegetative cover by natural processes. Severe sedimentation of streams
also is a common result of surface mining operations. Loss of trees on river .banks can cause
" Environmental Protection Agency (EPA). 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies
Under CERCLA. Office of Emergency and Remedial Response, Washington, DC. OSWER Directive No. 9355.3-01.
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Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk F-23
Assessment Guidance
bank degradation and increase surface water temperatures. Even for those impacts or
potential impacts that can be attributed to mining-related chemical stressors, options for
remediation can be limited:
Because of the large areas involved, it generally is not possible to reduce
substantially contaminant levels in soils;
Because of residual metal contamination in soils, it often is not possible to
reestablish native vegetation; and
Again, because of the large areas involved, it generally is not possible to
excavate contaminated sediments in affected surface waters.
Sometimes more moderate goals can be met:
Containment of sources of contamination to surface waters usually is possible;
and
Establishing some type of vegetative ground cover maybe possible and
important for control of erosion due to wind and precipitation as part of a
containment strategy.
For older mining sites at which revegetation already has occurred naturally over waste pile
areas, it may be preferable to leave the piles in place rather than to remove or disturb the piles
and eliminate the established vegetation.
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Primary
Source
Appendix D: Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
HisUisMF-12
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-2S
Guidance
F.8 Initiate Potential Federal/State ARARs Identification
CERCLA requires that Superfund remedial action.meet;other federal and state standards,
requirements, criteria, or limitations that are "SpplicaBle or relevant and appropriate" (ARARs).
The on-scene coordinator (OSC) or the RPM must identify potential ARARs for each site.
EPA's R/s/c Assessment for Superfund: Volume 2 - Environmental Evaluation Manual
summarizes ARARs relevant to ecological concerns at Superfund sites.
For mining sites with on-site or nearby surface water or wetlands, state water quality standards
for designated uses of rivers, streams, or lakes are ARARs. These may include narrative free
from toxics and antidegradation standards.' State chemical-specific numeric standards usually
are adopted or modified from EPA's Federal Ambient Water Quality Criteria (AWQC), which are
ARARs in the absence of state standards for a particular contaminant or water conditbn.
EPA's AWQC include criteria to protect fresh and salt water plants and animals and their
habitats from acute and chronic exposures to toxic substances in surface waters (but not in
sediments). EPA AWQC were promulgated pursuant to the Federal Water Pollution Control
Act, as Amended (Clean Water Act). This law also requires protection of wetlands and other
areas and may pertain in several ways to the remediation of mining sites located near wetlands
or surface water bodies.
EPA's Storm Water Regulations (40 CFR Part 122) establish requirements for storm water
discharges associated with "industrial activity", including inactive mining operations that
discharge storm water contaminated by contact with, or that has come into contact with, any
overburden, raw material, or waste products located on the site of such operations (inactive
mining sites are mining sites that are not being actively mined, but which have an identifiable
owner/operator) (40 CFR 122.26(b)(14)). See Appendix E for a further discussion of the
implications of this ARAR to mining Superfund sites.
Other federal environmental statutes and regulations that include ecologically relevant ARARs
are summarized below:
Endangered Species Act of 1973, as reauthorized in 1988. This Act requires
federal agencies to ensure that their actions will not jeopardize the continued
existence of any endangered or threatened species. Many mining sites are
located in otherwise pristine areas that have historically supported a variety of
wild flora and fauna, and the ecological assessment should determine if there is
a possibility of endangered or threatened species in the vicinity of the site. If
there is, EPA must consult with the FWS.
Fish and Wildlife Conservation Act of 1980. This Act requires states to
identify significant habitats and develop conservation plans for these areas. The
OSC or RPM should consult the responsible state agency to determine whether
the mining site is located in one of these significant habitats.
Wild and Scenic Rivers Act of 1972. 0 This Act declares that certain rivers
should be preserved. The ecological assessment should determine whether
there are any designated Wild or Scenic rivers near the mining site.
" Environment^ Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfund: Volume 2 - Environmental
Evaluation Manual. Interim Final. Office of Solid Waste, Office of Emergency and Remedial Response, Washington, DC.
EPA/540/1-8ff001A. . .
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F-26 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Fish and Wildlife Coordination Act, as amended in 1965. This Act states that
the FWS must be consulted when bodies of water are diverted or modified by
another federal agency.
The Migratory Bird Treaty Act of 1972. This statute protects almost all native
bird species in the U.S. from unregulated "taking", which can include poisoning
at hazardous waste sites. This Act would probably apply at many mining sites.
The Surface Mine Control and Reclamation Act of 1977. This Act requires
that excavated surface mines be filled in with the overburden stripped from the
mines, returning the area approximately to its original contour.
In addition to federal regulatbns, other state and local requirements also may be applicable or
relevant and appropriate. Consult the CERCLA Compliance With Other Laws ManuaP for
more detailed information on ARARs and their relevance to Superfund cleanups of mining sites.
Also, consult with the BTAG.
F.9 Identify Initial Data Quality Objectives (DQOs)
Chapter 7, Sampling and Analysis, discusses DQOs. The field data for site characterization
must be accurate and amenable to statistical analysis. Consequently, DQO's reflect the
statistical design of the study and the level of significance heeded to support any conclusion
that might be drawn from the study (see.also ECO Update, Volume 1, Number 413). In
particular, the RPM should ensure that minimum sample sizes to allow statistically valid
analyses are specified for each type of study or each study area. In general, the more variable
the attribute being measured, the more samples will be required to demonstrate significant
differences between control and test groups or between reference and study areas. Data
quality objectives also should address sampling completeness, comparability,
representativeness, precision, and accuracy, as described below.
Completeness. To ensure a complete data set for statistical analysis with acceptable
confidence limits, minimum sampling requirements should be described and contingency plans
established for problems that might occur and affect the completeness of the field data. For
example, some sample locations may be inaccessible, some samples might not be analyzed for
certain substances due to matrix interference, and other samples might be invalid due to
holding time violations. It also is important to identify the environmental data that need to be
collected concurrently with biological or chemical samples (e.g., water temperature, pH,
dissolved oxygen, water hardness).
Representativeness. It is important that the sampling locations be representative of the
media, habitats, and exposure areas at the site, i.e., that the locations are typical or
characteristic of the media/habitat, and not unusual in some way that might bias the results.
Comparability. Combining results from several analytic techniques and sampling events
usually is necessary for the baseline risk assessment. When toxicity tests or communiiy
surveys are conducted on samples from the site, analytic chemistry should be performed on
samples taken from the same location at the same time. If sampling is conducted in more than
one phase and data from different phases of the study are to be combined, special attention to
" Environments! Protection Agency (EPA). 1988. CERCLA Compliance with Other Laws Manual, Parti. Office of Emeigency
and Remedial Response, Washington. DC. OSWER Directive 9234.1-01.
" Op. CM. 3.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
F-27
factors that could affect sample comparability is needed (e.g., detection limits, sample
preparation procedures, season or other time-variable attributes that might affect results).
Precision and Accuracy. The contractor's work plan should establish quality.eontrol
procedures to ensure precision and accuracy for field work and laboratory analyses for activities
including sample handling, controls for tests, and numbers of replicate analyses. Use of
standardized methods, when appropriate, facilitates quality control; standardized protocols can
be found in EPA manuals and are utilized by the contract laboratories that routinely conduct
tests for EPA. As described in ECO.Update, Volume 1, Number 414, some laboratories have
established standard quality control.procedures for aquatic toxicity tests conducted under the
National Pollutant Discharge Elimination System (NPDES) (e.g., with fathead minnows,
Daphnia, algae). Many states have certification programs for these laboratories' tests. For less
standardized procedures, appropriate quality control measures need to be specified. For
example, an independent taxonomist could enumerate and classify the organisms found in a
randomly selected set of benthic invertebrate samples.
F.10 Prepare Statement of Work for the Site Characterization Phase
The project requirements for the RI/FS should be identified and documented in a statement of
work (SOW) developed by EPA. The contractor or PRP performing the field investigation then
develops project plans including the work plan, sampling and analysis plan, and field sampSng
plans (Highlight F-6) that address the SOW. The project plans for the ecological assessment
need to be developed in conjunction with the human health risk assessment team. The RPM
should schedule a review of the contractor or PRP's work plan by the BTAG before field work
begins. In several Regions, BTAGs have prepared example SOWs or other guidance materials
for RPMs. ECO Update, Volume 1, Number 415 explains how to develop a SOW.
Overview. The SOW and project plans for the Rl should define the objectives of the study, the
proposed field or laboratory methods (with appropriate reference to Agency guidelines or other
sources), expected sampling locations and sizes, the statistical methods to be used, and data
quality objectives and control procedures. The success of a work plan for the Rl site
characterization and baseline risk assessment may be enhanced considerably by developing
preliminary hypotheses regarding:
Contaminant sources and migratbn pathways;
The nature and extent of existing contamination at the site;
The potential for future releases and further contamination at the site; and
The number and types of habitats that might be contaminated now or in the
future.
These preliminary hypotheses, in turn, will assist in identifying or determining:
Specific areas at the site and in the surrounding area that need to be sampled or
surveyed; and
The number of chemical samples (and sampling locations) that will be required
to adequately characterize the existing or potential future contamination.
The SOW and work plan also should discuss how decisions will be made about the need for
additional studies.
•' Ibid.
;1 Op. Cit. 3.
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F-28 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance ^__^__
Specific tasks. The remainder of this section outlines specific tasks associated with
developing initial hypotheses about existing and potential future contamination. As a general
rule, it is helpful 0 focus first on areas of known contamination and sources that have released
contaminants, develop hypotheses regarding the magnitude and areal extent of known
contamination, and then develop hypotheses regarding the potential for future contamination.
Task 1: Coordinate with human health assessment team
Usually, the ecological assessors identify areas and types of samples that are needed in
addition to those identified by the human health team. If the human health assessment team
has the lead in developing the field sampling plan, the ecological assessment team must review
the plan to determine if additional samples are required for the ecological assessment.
Task 2: Coordinate with natural resource trustees and the BTAG
The success and efficiency of the site sampling effort will be enhanced considerably by close
coordination with the natural resource trustees and the BTAG. At a minimum, trustees should
be involved in review of the initial and final sampling plans. Because trustees are required to
quantify natural resource injury and damage, they might need to conduct sampling beyond what
EPA needs for a baseline risk assessment. For example, the trustee may need to demonstrate
the areal extent of resource injury, while EPA may need only to demonstrate risk to those
resources. Because BTAGs generally include representatives from natural resource trustees
as well as provide technical assistance for conducting ecological risk assessments, the BTAG
also can help determine which types of samples are likely to be the responsibility of the trustees
and which should be collected by EPA.
Task 3: Delineate potential assessment areas
Often, large mining sites are subdivided into several operable units. The conceptual model of
the site should provide an overview of the relationship among operable units and the entire
watershed. To develop field sampling plans, however, it can be helpful to subdivide the site or
operable units into areas that may require different sampling strategies. Using the site map
developed with the conceptual model of the site, delineate areas on the map that may require
different investigation strategies. Usually, separate "assessment areas" should be delineated
for each combination of the following factors:
Type of medium being sampled (e.g., sediment, water, fish tissues);
Habitat or ecological receptor;
Contaminants of concern;
Level of contamination (e.g., cbse to a source, more distant, deposition area in a
stream);
Type of remediation likely, and
Expected response (either in terms of speed or type of response, e.g., reduced
contaminant concentrations) to potential remedial actbns.
Within each assessment area, determine whether any sampling location within the area could
be considered representative of the area or if a gradient of contamination is expected. To
maximize the efficiency of possible sampling designs, delineate assessment areas that are as
large as possible. Potential assessment areas may be refined based on site visits and as
hypotheses are accepted or new hypotheses are developed.
If more than one medium is to be sampled in a given type of habitat, the size of the assessment
areas may be different for each medium. For example, a set of sediment samples may be
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
F-29
considered representative of only a small portion of the length and width of a river, whereas a
set of tissue residue levels taken from fish captured at the same locations may be considered
representative of a larger section of the rivej. .s
_ "'•*«• *£'
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F-30 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Task 7: Identify specific biological data needs
There are four general types of biological samples that may assist in testing hypotheses about
ecological impacts: tissue residue samples, toxicity tests, biological field surveys, and
biomarkers. We discuss circumstances under which each of the biological sampling methods
might or might not be recommended for an ecological risk assessment below. Note that EPA
does not need to demonstrate conclusively that site contaminants caused existing impacts;
EPA need only demonstrate a risk of these impacts now or in the future to justify remedial
action.
Tissue residue samples offish, invertebrates, or other biota generally should be collected if
there is reason to suspect that these biota have been exposed to contaminants that are likely to
bioconcentrate (i.e., concentrate in tissues of aquatic organisms at levels higher than the
surrounding water). If a contaminant is known or expected to bioaccumulate (i.e., is found at
higher concentrations in organisms at each higher step in a food chain), samples should be
taken from biota at two or more trophic levels (e.g., plant, herbivore, carnivore) along with the
environmental media to which the biota are exposed. This is important because site-specific
conditions influence the magnitude of bioaccumulation, and most estimates of bioaccumulatbn
include a large range of uncertainty. Edible tissues (e.g., fillets) generally are sampled for
human health risk assessments; however, whole-body samples are more appropriate for
ecological risk assessments.
Toxicity tests evaluate the effects of contaminated media oh the survival, growth, behavior,
reproduction, and/or metabolism of test organisms. Toxicity tests conducted in the laboratory
generally use standard laboratory organisms (e.g., Daphnia, fathead minnows). Toxbity tests
conducted in situ (e.g., by caging test animals in the study area) can be used to evaluate
toxicity or bioavailability to the particular organisms of interest at the site. Toxicity tests
generally are recommended if:
The bioavailability of contaminants in particular media (e.g., sediments) is
unknown, which often is the case with contaminants at mining sites;
The contaminants are toxic below quantitation limits;
The toxicity of a particular site-specific mixture of contaminants in a given area
cannot be estimated readily; and
Supporting evidence for a hypothesized link between observed (or potential
future) contamination and adverse impacts is needed to make a remedjal
decision.
Which specific toxicity tests are most appropriate depends on the assessment endpointe.
EPA's Ecological Assessment of Hazardous Waste Sites: A Field and Laboratory Reference16
reviews aquatic, terrestrial, and microbial toxicity test methods, including both "off-the-shelT
methods and innovative procedures. Specific toxicity test protocols continue to be developed,
and the BTAG should be consulted to ensure that the most up-to-date protocols are used.
Biological field surveys need not be extensive, although they do require matching surveys
from an appropriate reference area for their interpretation. Field studies offer direct or
'"• Environmental Protection Agency (EPA). 1989. Ecological Assessment of Hazardous Waste Sites: A Field and Laboratory
Reference. Office of Research and Development, Environmental Research Laboratory, Coivallis, OR. EPA/600/3-89/013.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment-
Guidance
F-31
corroborative evidence of a link between contamination and existing ecological impacts but are
not required for most assessments. For example, field studies can be used to:
•£ i • . .-%•. t '
Document or verify the absence or reduced abundance of key native species;
Evaluate suitability of habitats for wildlife species of concern;
Identify evidence of stress (e.g., stressed or dead vegetation, bare soil and
erosion);
Identify changes in community structure (e.g., reduced biodiversity, altered
species composition);
Illustrate an increased incidence of lesions, tumors, or other pathologies; and
Document the presence or increased abundance of species associated primarily
with contaminated habitats.
If wetlands exist on or near the site, a functional evaluation of wetiands (e.g., value as wildlife
habitat, for pollution abatement/or flood control) might be appropriate. EPA's Ecological
Assessment of Hazardous Waste Sites: A Field and Laboratory Reference™ includes a review
of field survey methods for aquatic ecosystems and terrestrial vegetation, invertebrates, and
vertebrates.
Biomarkers of exposure (e.g., enzyme activity) can be measured to verify that organisms
inhabiting contaminated areas actually have been exposed to site contaminants. Given the
propensity of some metals to bioaccumulate as well as the availability of sensitive and accurate
techniques for routine detection of metals in biological samples, indirect indices for exposure to
metals generally are not needed. Erythrocyte ALAD (defta-aminoievulinic acid deyhdratase, a
cytosolic enzyme), an indicator of lead exposure, is an exception, because it can be measured
in blood samples, which allows non-destructive sampling. The Field and Laboratory
Reference18 gives examples of ALAD's use as an indicator of lead exposure in fish, waterfowl,
and mammals.
Highlight F-13 summarizes general types of chemical and biological studies that might be used
at Superfund mining sites and the information provided by each type.
Task 8: Coordinate data collection efforts with natural resource trustees
At some sites, natural resource trustees might need to use biological surveys to document and
quantify existing damages to trustee resources from site contaminants. It is very important to
coordinate data collection activities with the natural resource trustees:
To avoid duplication of effort;
To maximize the usefulness of each type of data collected; and
To maximize the efficiency of data collection.
EPA has developed a Superfund fact sheet that explains in more detail how to coordinate
ecological data collection activities with natural resource trustees.
:" Ibid.
'" Ibid.
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F-32 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Task 9: Develop initial field sampling plan
In conjunction with the human health assessment team, develop an initial field sampling plan for
the site characterization phase of the Rl. Sampling bcations established in the initial samplrig
plan should address al relevant sources, existing contaminant migration pathways, potential
future contaminant migration pathways, and habitats of concern. Using the conceptual model
of the site as a guide, the initial field sampling plan should include at least the following:
A list of specific hypotheses to be tested with sampling;
For each hypothesis,.the type of information that would support or reject the
hypothesis;
For each hypothesis, thetype(s) of samples or observations that will provide the
required information;
A preliminary delineation of specific assessment areas to be sampled; and
A listing of available sampling information for each assessment area.
For each proposed assessment area and type of sample (e.g., metals in soils), the field
sampling plan should determine the number of samples to collect and the specific bcations for
each sample. This is one of the most difficult tasks in preparing the project plans. A trade-off
exists between the number of samples taken (and hence degree of certainty) versus the time,
effort, and expense involved in obtaining and analyzing each sample. Suggestbns on how to
select the location and number of surface water and sediment samples are contained in the
appendices to EPA's Oversight document19 and in EPA's Standard Operating Procedure
ManuaP0. These documents provide basic rules of thumb for determining number of sampling
locations for rivers, streams, and creeks (examples in Highlight F-14); for lakes and ponds
(examples in Highlight F-15); for impoundments and lagoons; and for estuaries. Some general
suggestions to help in developing a field sampling plan for each assessment area follow.
Hypotheses to test. Begin with the hypotheses identified in Tasks 4 and 6 about contaminant
sources, migration pathways, extent of contamination, bioavailability, and other concerns. It
may help to redefine some of the assessment areas in light of the hypotheses to be tested.
Sample locations. Within each assessment area, begin with the location where contaminant
concentrations are expected to be greatest. These may indude the point(s) at which
contaminants are most likely to enter the assessment area (e.g., the point of groundwater
discharge into surface water), the point(s) in the assessment area closest to key sources, and
points where soils, sediments, tailings, or other debris are likely to accumulate (e.g., bends in
rivers where sediments accumulate). Second, estimate the potential extent of contamination.
Sampling information obtained for HRS scoring and evidence visible in aerial photographs (e.g.,
tailings, sediment deposits) might help determine tentative sampling distance limits. Third,
select sampling locations between the sources and the expected sampling distance limits and
just beyond those limits. Where appropriate, use rules of thumb as shown in Highlights F-14
and F-15. If during the field sampling, contamination attributable to the site is found beyond the
tentative sampling distance limit, it may be necessary to collect more distant samples to
determine the full extent of contamination.
"• Environmental Protection Agency (EPA> 1991. Guidance on Oversight of Potentially Responsible Party Remedial
Investigations and Feasbility Studies. Volume 2. Appendices. Office of Sdid Waste and Emergency Response, Washington, DC.
OSWER Directive 9835.1 (c). EPA/540/G-91/010D.
•'" Environmental Protection Agency (EPA). 1986. Engineering Support Bianch. Standard Operating Procedures and Qualty
Assurance Manual. Region IV. Environmental Services Division.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-33
Guidance
Highlight F-13:
General Types of Studies and the Information They Provide
Type of Study
Information Provided
Samples of abiotic environmental
media (e.g., surface water, soils,
sediments)
Concentrations of specific contaminants in environ-
mental media at sampling point
Elevated concentrations demonstrate that
contaminants have reached sampling point
Concentrations can be compared to
ecological benchmark levels to assess risk
Tissue residue samples of fish,
invertebrates, or other biota (e.g.,
edible tissues, specific tissues such
as liver, whole body)
Concentrations of specific contaminants in specific
tissues and/or whole body of organism
Elevated concentrations demonstrate that
organism has been exposed to contaminants
Concentrations can be compared to predicted
levels to calibrate bioaccumulation and expo-
sure models
Concentrations can be used to directly esti-
mate dietary exposures at the next trophic
level
Toxicity tests (laboratory or in situ)
using soils, sediments, or surface
water from the site
Bioavailability of contaminants in environmental
medium or media
Toxicity of specific mixture of contaminants in envi-
ronmental medium or media
May provide supporting evidence for a link between
contamination and adverse impacts
Biological surveys of population
abundance or community structure
Documentation or verification of altered populations
or communities
Absence, abundance, or density of particular
species
Community structure (e.g., species diversity,
species composition)
Biomarkers of exposure or effects
(e.g., biochemical or physblogical
markers; lesions, tumors, or other
morphological abnormalities)
Specific biochemical or physiological changes may
demonstrate that organism has been exposed to
particular contaminants
Increased incidence of gross pathologies or morpho-
logical changes demonstrates that organisms are
experiencing adverse impacts
May provide supporting evidence for a link between
contamination and adverse impacts.
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F-34 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Task 10: Determine location and number of required samples
Highlight F-14:
Example Rules of Thumb for Sample Collection in Rivers, Streams, and Creeks
To ensure representativeness, samples should be taken immediately downstream of
a turbulent area, or downstream of any marked physical change in the stream channel.
At least three locations between any two points of major change in a stream (such as
waste discharge or tributary) should be sampled to adequately represent the stream.
Typically, sediment deposits' in streams collect most heavily in river bends, downstream
of islands, and downstream of obstructions in the water.
Samples should not be taken immediately upstream or downstream from the confluence
of two streams or rivers because of the possibility of backflow and inadequate mixing.
Highlight F-15:
Example Rules of Thumb for Sample Collection in Lakes and Ponds
If stratification is present in a lake or pond, each layer of the stratified water column
should be sampled separately. Stratification can be determined with temperature,
specific conductance, pH, or dissolved oxygen vertical profiles.
In ponds, a single vertical composite at the deepest point may be representative. In
naturally formed ponds, the deepest point is usually near the center.
In lakes, several vertical composites should be taken along a transect or grid in order
to ensure that the samples are representative.
Sediment samples in lakes, ponds, or reservoirs should be collected approximately at
the center of the water mass where contaminated fine-grained materials are most likely
to collect.
Sample number. EPA's Oversight document21 and Standard Operating Procedure Manual22
provide some rules of thumb for determining a minimu m number of samples to obtain (example
in Highlight F-14). The variability in contaminant concentrations among samples will influence
the number of samples required to characterize an area within specified statistical confidence
limits. Estimate the expected variability among samples. Sampling results from other
Superfund mining waste sites might be helpful in determining how much variability may be
expected and how many samples are needed per unit area.
Sampling times. Determine the times of year or conditional events (e.g., snow melt) when
samples should be collected. It is best to collect media samples during perbds when
environmental conditions favor the concentration of chemicals in environmental media (e.g.,
avoid high-flow conditions unless immediately following a storm event that might increase
contaminant concentrations in the surface water via runoff).
Reference area. Finally, reference samples should be taken from an appropriate reference
area (see section F.5, Task 7) to determine background levels of contamination.
Iterative process. It can be helpful to determine the number and locations of samples
iteratively, starting with an initial, general plan for each assessment area, and refining these
« Op. Cit. 19.
Op. Cit. 20.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
F-35
plans based on the specific sampling requirements for the area and how these relate to the
requirements for other areas. ECO Update Volume 1, Number 423, explains this phased
approach in more details. ' '; ;f *;
Sampling plan. Once the number of samples that are needed for each assessment area is
determined, expected sampling locations (including detailed maps) and sampling dates should
be specified (and time of day if important).
Task 11: If needed, plan further site visit(s) to characterize potential ecological
receptors
If any questions remain concerning the potential ecological receptors of concern (e.g., species
present, habitat characteristics), another site visit with a trained ecologist/biologist(s) should be
planned (see section H.5, Tasks 7 and 8). If a Preliminary Natural Resource Survey (PNRS) is
needed and has not yet been conducted, the natural resource trustees should be encouraged
to conduct the preliminary PNRS at this time.
F.11 Ecological Risk Assessment Guidance
After the initial sampling and studies for the Rl are completed, the data are evaluated to
determine if the baseline ecological assessment can be completed based on the data. This
section describes the steps of the ecological assessment by which this determination is made.
Section H.12 describes the objectives and rationale of the ecological assessment. The
remaining sections describe the assessment in terms of the three components of ecological risk
assessment: exposure assessment (section H.13), ecological effects assessment (section
H.14), and risk characterization (section H.15).
F.12 Objectives and Rationale
As described in section H.4, the baseline ecological risk assessment should provide the
information to answer key questions:
Is there a potential for an adverse effect on ecological receptors; and
If there is, what type of remedy would be needed to be protective?
In addition, the ecological risk assessment should:
Describe the observed or potential magnitude of adverse ecological effects at
the site and the primary cause of the effects; and
Characterize the ecological consequences of the "no further action" remedial
alternative;
Determine if special measures need to be taken during remediation to protect
habitats; and
Determine what monitoring will be-needed to ensure protection of ecological
receptors during and after remediatbn.
During the ecological assessment, the data obtained during the initial Rl site studies are used to
refine information on the extent and magnitude of existing contamination of soils, other surface
:1 Op. Cit. 3.
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F-36 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
substrates, surface waters, and sediments; to determine whether nearby habitats are
contaminated; and to determine whether levels of contamination are sufficiently high to pose a
reasonable likelihood of ecological risk now or in the future. For enforcement lead sites, a key
purpose of the ecological assessment is to determine whether information is sufficient to
establish and to defend an endangerment finding. It is not necessary to prove that impacts are
occurring as a result of site contaminants, however (see Highlight F-16).
Highlight F-16:
Objectives of the Baseline Ecological Risk Assessment
The baseline ecological risk assessment summarizes information on contamination and
observed impacts to determine whether existing contamination is likely to result in significant
risk, and to determine whether additional information is required to identify remedial alternatives
and goals that are protective of ecological receptors. For this assessment, it is not necessary
to conduct detailed studies to demonstrate a definitive causal link between existing
contamination and observed impacts. The ecological risk assessment does not have to prove
that impacts are occurring as a result of contamination; instead, the risk assessment need only
demonstrate that the release poses a risk of impacts.
Although EPA's remedial measures must eliminate, reduce, or control risks to the environment,
it is not necessary for these measures to restore or replace affected natural resources.
Restoration on replacement generally is the responsibility of the natural resource trustees
unless the remedy itself results in injury to natural resources. For example, EPA may need to
replace a wetland that is capped to prevent further contaminant migration, but EPA may not
need to restore a contaminated wetland if the remedy prevents further migration of
contaminants to that wetland.
It can be eaaer to demonstrate that a community (e.g., aquatic community, soB invertebrate
community, terrestrial plant community) is at risk of adverse effects than to demonstrate that a
given wildlife population is at risk. If one can delineate areas of a habitat that are contaminated
at levels that might harm a proportion of the community or a key community species (e.g., the
dominant species of vegetation), one can predict that the portion of the community present
within these areas is at risk of adverse effects. Questions for a community-level assessment
might include:
Are the hot spots at the site sufficiently contaminated to impair the community?
What proportion of the community is contaminated at levels that could result in
chronic adverse effects?
For a population-level (species-specific) assessment, one needs to ask different questions:
If an animal were to obtain a single prey or a single days worth of food from a
hot spot at the site, would it be at risk of acute poisoning?
If an animal is not at risk of acute poisoning, is a large enough proportion of the
home range of a single animal contaminated at sufficient levels that the animal
might suffer chronic effects from longer-term exposures?
How many individuals of a species might be exposed above acute and/or chronic
toxicity benchmarks?
The remainder of this section outlines specific tasks associated with analyzing the field data to
complete the ecological risk assessment (i.e., exposure assessment, ecological effects
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-37
Guidance
assessment, and risk characterization), distinguishing community-level from population-level
considerations.
"3 .-i If . »
F.13 Exposure Assessment
The exposure assessment quantifies the magnitude and type of actual or potential exposures of
ecological receptors to site contaminants. It includes four key elements:
f*
Documenting contaminant release, migration, and fate;
Characterizing receptors;
Measuring or estimating exposure concentrations; and
Analyzing uncertainty.
Quantifying release, migration, and fate For detailed guidance on quantifying contaminant
release, migration, and fate, consult EPA's Risk Assessment Guidance for Superfund: Volumes
124 and 225 and the Exposure Assessment Guidelines^*. In addition, the Exposure Factors
Handbook, Office of Research and Development (ORD), EPA 1996, should be considered as a
source/ Parameters critical for determining the environmental behavior of contaminants,
including transport through the environment (e.g., through air or the food chain), include
physical transformation (e.g., volatilization, absorption, precipitation), chemical transformation
(e.g., photolysis, hydrolysis, oxidation, reduction), bblogical transformation (e.g.,
biodegradation), persistence, and bioaccumulation.
Characterizing receptors Although assessment endpoints and receptors were selected
during the scoping phase of the Rl, new information from the field investigation should be
evaluated to determine whether there may be populations, species, or communities exposed
other than those that were identified initially. Any gaps in information needed to characterize
receptors should be identified. Receptor characterization differs for community-level and
population-level assessments, as described below.
Community-level assessments. If terrestrial, wetland, or aquatic communities are compo-
nents of the assessment endpoint, key attributes of the communities that help define the
measurement endpoints need to be characterized (e.g., dominant vegetation; species
composition of a cold-water fishery).
Population-level assessments. If populations of selected species (e.g., an endangered
species) have been designated as receptors for evaluation, determine the potential relationship
that the animals' foraging, drinking, and other activities have to the spatial extent of contamina-
tion at the site. If contaminants are known or expected to bioaccumulate, identify the trophic
level of the species of concern (i.e., the approximate number of steps in the food chain from
primary producers to the animal in question). Initially, it would be appropriate to assume the
highest trophic level consistent with a species' dietary habits. EPA's Great Lakes Water Quality
'•' Environment^ Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfind: Volume 1 - Human Health
Evaluation Manual. Interim Final. Office of Solid Waste, Office of Emergency and Remedial Response, Washington, DC.
EPA/540/1-89/002.
•" Op. Cit. 11.
" Environmental Protection Agency (EPA). 1992. Guidelines for Exposure Assessment. Science Advisory Board, Washington,
DC.
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F-38 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Initiative has assumed that mink, kingfishers, and ospreys feed at trophic level 3, that otters
obtain half of their diet at trophic level 3 and half at trophic level 4, and that bald eagles feed at
trophic level 4. EPA has not yet developed guidance for determining trophic levels. Consult
with the BTAG for advice.
Measuring or estimating exposure concentrations EPA's Framework for Ecological Risk
Assessment defines exposure as the co-occurrence of or contact between a stressor and an
ecological component. The receptors of concern dictate how one evaluates patterns of
contamination in time and space to predict potential impacts. In this section, we describe
approaches to defining exposure concentrations for community-level and population-level
assessments.
Community-level assessments. Most community assessments require comparison of
chemical concentrations in key media (e.g., surface water, sediments, or soil) to benchmark
levels for these media above which adverse community-level effects might be expected. It may
be useful to overlay a map of the communities of concern at the site with a map of the
contamination pattern found during the field investigation.
The values measured during the initial field sampling of the Rl can be used to estimate current
exposure levels. Fate-and-transport models are needed to predict the movement of
contaminants in the future. In some cases, it may be difficult to measure existing contamination
during site visits (e.g., some areas may be flooded, streams may be in high flow, certain
locations may be physically inaccessible or too dangerous to sample). In these cases,
modeling and estimation techniques can be used in place of field sampling results.
There are two basic options for evaluating current or future environmental concentrations:
Estimating environmental concentrations only at the point of maximum predicted
concentration in each assessment area (or community) to allow a point estimate
of risk; and
Estimating the areal extent of contaminant concentrations in each assessment
area or community to allow an area! estimate of potential impacts (e.g., 10
stream miles or 5 acres exposed above benchmark levels).
The basic information provided by the point estimate of risk is a quantitative estimate of the
number of habitats or areas likely to be contaminated above ecological benchmark levels. The
basic information provided by the area! estimate of risk includes a quantitative estimate of the
total amount (or proportion) of each habitat or area likely to be contaminated above ecological
benchmark levels.
The first of these two options might serve as an initial step to identify assessment areas to
which the second option might apply. The second option might be helpful in comparing relative
risks. For example, chemical concentrations could be measured at the bcation(s) where
contaminatbn is predicted to be maximal (e.g., point where groundwater discharges into
surface water). If these measured concentrations fall below ecological benchmarks, it is
unlikely that further evaluation of the pathway(s) will be needed. In contrast, if the measured
concentrations exceed ecological benchmarks, it may be useful to estimate the areal extent of
the benchmark exceedance. If a benchmark for chronic exposures is exceeded over a small
!' Environmental Protection Agency (EPA). 1992. Great Lakes Water Quality Initiative Procedure for Deriving Criteria for the
Protection of Wildlife. Draft Office of Research and Development. Environmental Research Laboratory, Duluth. MM.
'"Op. Cit. 1.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-39
, Guidance
stream reach (e.g., 10 meters), few impacts on a local fish population might be expected. If, on
the other hand, chronic benchmarks were exceeded for many miles, significant impacts on the
fish population are possible. ^ 1? * •*
Species-level assessments. If one or more species have been designated for evaluation, the
home range size of these species should be used in determining the area over which to
evaluate contaminant concentrations. When assessing risks to wildlife species exposed to
chemicals, potential dose is often the metric used. Potential dose is described as the amount
of chemical in food or water ingested, air inhaled, or material applied to the skin29. Potential
dose is analogous to the administered dose in a toxicity test.
Equation for estimating potential dose. A general equation for estimating potential average
daily dose (ADDpot) for chronic exposures (i.e., at least a few weeks) is
ADDpot = [C x IR] / Wt (equation 1)
where
ADDpot = potential average daily dose (e.g., mg.contaminant/kg body weight-day),
C = P° contaminant concentration in the contacted medium (e.g., mg/kg in food
or water),
IR = ingestion rate measured as mass (wet weight) ingested by an animal per
unit time (e.g., kg/day), and
Wt = fresh body weight of the animal (e.g., in kg).
This simplified equation assumes that C and IR are constant over time, or averaged over the
exposure duration. Highlight F-17 presents two wildlife oral exposure equations corresponding
to two patterns of contamination of water or food:
(1) The animal obtains some of its water or food from a contaminated source and
the remainder from uncontaminated sources; and
(2) The animal consumes water or food from several sources that are contaminated
at different levels.
A frequency term (FR) has been added to the first equation to denote the fraction of time that
an animal is exposed to contaminated media (e.g., is present on the site). The concentration
(C) equals the mean value of the contaminant concentration in a single water or food source.
The second equation can be used when different water or food sources are likely to be
contaminated at different levels. In this case, consumption from different sources is weighted
by the proportion (P,) of the animal's total daily intake obtained from each source. FR and P, in
Highlight F-17 are functions of the degree of overlap of the contaminated resources and the
animal's home range. EPA's Wildlife Exposure Factors Handbook?0 provides a more detailed
discussion of these and other equations that can be used to calculate contaminant intakes for
species that consume more than one type of food.
For substances that bioaccumulate (see Highlight F-18), if measures of contaminant concentra-
tions in potential prey are unavailable, one should include a food-chain transfer model for
receptor species that feed at the higher trophic levels. For piscivorous wildlife (e.g., osprey,
:" Op. Cit. 24.
"' Environments* Protection Agency (EPA). 1992. Wildlife Exposure Factors Handbook. Prepared for the Office of Research
and Development, Office of Emergency and Remedial Response, and Office of Water by ICF Incorporated.
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F-40 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance ^ ^
bald eagle, mink, otter), the contaminant concentration in the prey is the concentration in the
contacted medium in equation 1. For aquatic food chains,
x BAFN
(equation 2)
where
Cproy - contaminant concentration in the prey (e.g., in mg contaminant/kg wet
weight of the prey),
Csw = contaminant concentration in surface water (e.g., in mg/L), and
BAFN = trophic level (N)-spetific bioaccumulation factor (e.g., L/kg).
Thus, the potential dose can be calculated in one step as shown in Highlight F-19.
FR
Wt =
n =
C,=
Highlight F-17:
Recommended Wildlife Exposure Equations for Oral Exposure
One Source of Contamination:
ADDpot = [C x IR x FR] / Wt
Different Sources with Varying Levels of Contamination:
n
ADDpot=[ (CiXPi)xIR]/Wt
= potential average daily dose (e.g., mg contaminant/kg body weight-day).
average contaminant concentration in a single water or food source (e.g., in mg/L or
mg/kg).
ingestfcm rate measured as mass (wet weight) ingested by an anim al per unit time (e.g.,
kg/day).
fraction of intake from contam inated material (unitless).
fresh body weight of the animal (e.g., in kg).
total number of sources.
contaminant concentration in the ith water or food source (e.g., in mg/L or mg/kg).
proportion of water or food consum ed from the ith source (unitless).
Bioaccumulation potential is the measure of the tendency for chem icals to preferentially
concentrate in the tissues of living organisms. There are two general measures: (1) the biocon-
centration factor (BCF), i.e., the equilibrium ratio of the concentration of a chemical in the tissue
and its concentration in ambient water, in situations where the organism is exposed through the
water only; and (2) the bioaccumulation factor (BAF), i.e., the equilibrium ratio of the concentra-
tion of a chemical in the tissue to its concentration in an environmental medium where the
organism and the food chain both are exposed.
The BAFN can be estimated in one of three ways (listed in order of preference):
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-41
Guidance
Highlight F-18:
Metals That May Bioaccumulate
x
Metals for which measured log bioconcentration
factors (BCFs) for one or more chemical species
exceed 3:
Cadmium
Lead
Mercury
Zinc
Copper
Manganese
Selenium
(1) Measured in the field for
organisms at trophic level N;»
(2) A BCF measured in the labora-
tory (preferably on a fish
species) multiplied by an
appropriate food chain
multiplier; or
(3) A BCF estimated from the log
of the octanol-water partition
coefficient (KjJ multiplied by
an appropriate food chain
multiplier. This method will not
work for most metals because
their propensity to btoaccumulate is not a function of the lipophilic properties of
the compound.
For most inorganic substances, BAFs equal BCFs, although bbaccumuiation of some trace
metals is substantially greater in internal organs than in muscle tissue in fish. For example,
BCFs for rainbow trout liver and muscle exposed to cadmium for 178 days were about 325 and
1 respectively.31 A food chain multiplier greater than one is applicable to most lipophilic organic
chemicals with a log K^, of four or more.
BAFs and BCFs can be found in EPA water quality criteria documents, published papers, the
AQUIRE data base, and other reliable sources. An uncertainty analysis is particularly important
for food chain models because the results of the models are highly sensitive to the magnitude
of the BAF used, which may or may not be appropriate for that particular site or prey. The
uncertainty can be reduced substantially by measuring contaminant levels in the prey of the
assessment species. Generally, whole body contaminant levels are needed, not just fillet
contaminant levels as might be measured for the human health assessment.
F.14 Ecological Effects Assessment
Ecological effects assessment consists of quantifying the relationship between exposure
concentrations and adverse effects in ecological receptors. Existing ARARs for the protection
of aquatic life (i.e., state water quality standards, EPA's AWQC), published studies, biological
field studies at the site, and/or toxicity testing can provide the 'dose-response' informatbn. It
usually is not necessary to quantify the full dose-response curve; determining what exposure
level represents a threshold for an adverse effect can suffice. In this appendix, we refer to this
threshold as a toxicity benchmark.
In the remainder of this section, we first discuss both community-level and species-level toxicity
.benchmarks. By comparing exposure levels with benchmark values developed from available
literature, the site assessors can decide whether they need to proceed further with ecological
effects investigations such as toxicity tests or field studies.
" Giles, M.A. 1988. AccumulaSon of cadmium by rainbow trout. Salmo gairdneri, during extended exposure. Canadan Journal
of Aquatic Science 45:1045-1053.
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F-42 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
BAFN =
IR =
Wt =
n =
BAFNi =
Highlight F-19:
Recommended Wildlife Aquatic Food-Chain Exposure Equations
Prey from One Trophic Level:
ADDpot = [Csw x BAFN x IR] / Wt
Prey from More than-One Trophic Level
average daily potential dose (e.g., mg/kg-day).
average contaminant concentration in surface water within the animal's home range
(e.g., mg/L).
trophic level (N)-specific bioaccumulation factor (e.g., L/kg).
ingestion rate measured as mass (wetweight) ingested byan animal perunittime (e.g.,
kg/day).
fresh body weight of the animal (e.g., in kg).
total number of trophic levels.
trophic level (N)-specific bioaccumulation factor (e.g., L/kg) for the ith trophic level.
proportion of prey at the ith trophic level (unitless).
Community-level benchmarks
Water quality standards and criteria for the protection of aquatic life. When available,
state water quality standards for designated uses of surface waters are ARARs (see Section
H.8). When state standards are not available, EPA ambient water quality criteria (AWQC) for
the protection of aquatic life are ARARs. These water-concentration benchmarks for the
protection of aquatic communities are available for most of the hazardous substances found at
mining sites (e.g., metals, cyanide). Most of the state standards have been adopted from or
modified from EPA AWQC. These ARARs are available for acute (1-hour) and chronic (4-day)
exposures. Many of the criteria for metals depend on water hardness, and a few criteria
depend on pH.
Other community-level benchmarks. Highlight F-20 provides examples of community-level
benchmarks in addition to water quality ARARs. There is no EPA consensus at this time on
use of these other benchmarks; consult with the BTAG to determine if any of these benchmarks
are appropriate or if a different approach is needed (e.g.* using toxicity tests).
Species-level benchmarks Highlight F-20 also provides examples of species-level
benchmarks. It is important to remember that EPA's AWQC, and consequently most state
standards, for the protection of aquatic communities are unlikely to be protective of piscivorous
(i.e., fish-eating) wildlife if the substance bioaccumulates (e.g., mercury, selenium, cadmium).
A food-chain model was not used to determine AWQC, even when toxicity to wildlife (e.g., PCB
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
Guidance
F-43
toxicity to mink) was considered in setting the criterion. If any piscivorous species are of
concern in the area, consult with the STAG for an update on available information and
procedures. •• " fi
EPA's Office of Water/Office of Science and Technology (OW/OST) is developing surface
water criteria for the protection of terrestrial piscivorous wildlife. The criteria assume, that the
exposed species obtains all of its diet from the surface water body in question. EPA has not yet
specified what temporal or spatial averaging requirements will apply to the wildlife surface water
criteria. We therefore outline an approach consistent with OW/OST's methodology that can be
used in the interim to develop surface water benchmarks for piscivorous wildlife. The
benchmark is calculated on the basis .of two values: (1) an animal's intake of the contaminant
that can be attributed to the surface water contamination; and (2) a reference dose of contami-
nant above which adverse effects on the animal's growth, development, reproduction, or
survival can be expected.
Section H.13 described how intakes of contaminants that can be attributed to surface water
contamination can be calculated for piscivorous wildlife. For purposes of setting a screening-
level benchmark, one can assume that the animal obtains all of its food from the contaminated
surface water. The second value required to calculate a surface water benchmark protective of
piscivorous wildlife is the reference dose, i.e., a chemical-specific reference toxicity value (TV),
as described in the next paragraph.
Determining a reference toxicity value (TV). Toxicity values (TVs) should be developed by a
terrestrial wildlife toxicologist. A TV can be estimated from a no-observed-adverse-effect level
(NOAEL) multiplied by a species sensitivity factor (SSF), as described below.
From the available iterature, a chronic NOAEL is identified. Peer-reviewed field studies of
wildlife species are used when available. In the absence of field studies, laboratory studies with
surrogate species (e.g., rat, northern bobwhite) can be used. EPA's Great Lakes Initiative32
recommends the following data requirements for chronic studies:
For laboratory mammals, at least one well-conducted subchronic study
consisting of repeated oral exposure for 90 days or longer, or at least one well-
conducted reproductive or developmental effects study consisting of repeated
oral exposures.
For laboratory birds, at least one well-conducted study of 28 days or greater
designed to observe subchronic as well as reproductive or devebpmental
effects.
If a NOAEL is unavailable, it can be extrapolated from a lowest-observed-adverse-effect level
(LOAEL) by dividing the LOAEL value by a factor ranging from one to ten. If chronic data are
unavailable, a subchronic value can be used, dividing by a factor of'up to ten to extrapolate to
the longer exposure duration. Finally, the NOAEL is converted to mg/kg-day (i.e., milligrams
contaminant eaten per kilograms of consumer organism's body weight per day) basis if it is not
already in these units.
'-' Op. Cit. 25.
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F-44 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
Highlight F-20:
Types of Ecological Benchmark Values
Type of Benchmark
Surface water benchmarks for the
protection of aquatic life (i.e., non-
benthic aquatic communities)
Sediment benchmarks for the pro- ' • _
tection of benthic invertebrate com-
munities
Surface water benchmarks forthe
protection of fish-eating wildlife species
Fish flesh benchmarks for the pro-
tection of fish-eating wildlife species
Soil benchmarks protective of plant
communities
Soil benchmarks protective of soil
invertebrate communities
Soil benchmarks protective of ter-
restrial vertebrate species
Ambient air standards protective of
terrestrial plant communities
Examples or Approach
State water quality standards^
EPA ambient water quality criteria (AWQC)-
EPA ambient aquatic life advisory concentrations
(AALAC)
Toxicity values/extrapolation factor(s)&'
EPA interim sediment quality criteria2'
Apparent effects threshold (AET)
Sediment quality triad
Screening-level concentration (SLC)
EPA water quality criteria for the protection of teirestrial
wildlife?
New York State fish flesh criteria^'
Toxicity values from PHYTOTOXdata base
Toxicity values for selected invertebrate species (e.g.,
earthworms, amphipods)
Soil criteria derived from dietary toxicity values and
specific exposure parameters for selected vertebrate
species?
Some secondary National AmbientAir Quality Standards
(NAAQS)
- These ARARs are available for most of the contaminants found atmining sites,
- As an example, a crronic benchmaik may be derived by dividing a LOAEL by a numeric factor b account for variation in species
sensitivity (see text).
• EPA sediment benchmaiks are not avalable for metalsat present. For a review of approaches to de/eloping sediment quality criteria,
see Chapman". The STAG should be consulted t> determine which approach(es) is most appropriate for a partbular site.
- Back'Catculaloa benchmark surface water concentration from bioaccumulalon factor values for aquatic food items and water
consumption, aquatic food consumption, and toxicity (or selected avian and mammalian species".
• BacX*caIcu1atea benchmark fish flesh concentration from fish consumption and toxicity data for selected avian and mammalian species".
? BacX-calculatea benchmark soil concentrator! using body mass, dietary intake, bioaccumilation facers, and dietary toxicily values for
feprosentatvo birds and mammals assuming direct coriact and food chain exposures". Depending on how receptors and endpoints have
been donned (see section 2.2. tasks 3 and 6). one or both of two types of assessm ents typically are useful: community-level assessments
and population-level assessments.
Data rarely are available for the assessment species; therefore, an extrapolation factor to
account for differences in species sensitivities to the substance usually is developed. A species
sensitivity factor (SSF) typically falls between 1 and 0.01 depending on the amount and quality
of data available on the toxicological, physicochemical, and toxicokinetic properties of the
substance. An SSF of one is used if the data are from numerous species or if the data are from
the only species of concern.
" Chapman. P.M. 1989. Current approaches to developing sediment quality criteria. Environ. Tox'col. Chem. 8:589-599.
" Environmental Protection Agency (EPA). 1991. Assessment and Control ,cf Bioconcentiatable Contaminants n Surface
Waters. June 1989 Draft prepared by EPA's National Effluent Toxicity Assessm ent Center, Environmental Research Laboratory -
Duluth. MM: Office of Water Enforcement and Permits. Office of Water Regulations and Standards - Washington, DC; and Office of
Health Effects Assessment - Cincinnati. OH
" New York State Department of Environmental Conservation (NY DEC). 1987. Niagara Riser Biota Contamination Project:
Fish Flesh Criteria forPiscivorous WiUlife. Division of Fish and Wildlife, Bureau of Environmental Protection. DEC Publication,
Technical Report 87-3.
Op. Cit. 28.
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RisK Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-45
Guidance
Estimating a benchmark concentration for surface water (BCSW) for the protection of
piscivorous wildlife. The benchmark contaminant concentration in surface water (BCSJ now
can be estimated as described in equation 3.
Bcsw = [TV x WtA x SSF] / [IR x BAFN](equation 3)
where
Bc,w =benchmark contaminant concentration in surface water (e.g., mg/L).
wildlife chronic toxicity reference value (e.g., mg/kg-day).
consumer animal's fresh body weight (e.g., kg).
species sensitivity factor as defined in text.
food ingestion rate of consumer species (e.g., kg/day).
bioaccumulatidn factor (e.g., L/kg) for the Nth trophic level.
TV =
WtA =
SSF =
IR =
BAFN =
Toxicity tests Toxicity tests on media from the site, in combination with data on chemical
concentrations and field studies, can provide important supporting evidence that observed
effects are attributable to the presence of hazardous substances. Several factors need to be
considered, however, in interpreting (and consequently planning) toxicity tests, as discussed
briefly bebw.
Species sensitivity. Different species show varying sensitivities to different toxic substances.
For a community-level assessment, it would be important to encompass the range of species
sensitivities likely in the community of concern. There are several approaches to this problem.
For some contaminants at some sites, the most sensitive resident species may already be
known from previous work at the site. For aquatic communities, EPA's Office of Water has
suggested a sliding scale of species-sensitivity extrapolation factors depending on the number
of different genera tested.37 Another approach is described in Highlight F-21. Consult the
BTAG for the most appropriate approach for a site.
For a species-level assessment, the choice of number of test organisms and which test
organisms to use depends upon how similar the available test species are to the assessment
species, what is known about the contaminant's toxicity, and other factors. Again, consultation
with the BTAG generally is necessary to ensure that appropriate procedures are applied to plan
toxicity tests and interpret their results.
Duration of test. If chronic exposures are of concern, chronic bioassays should be used. To
reduce the time and expense of testing, however, it may be possible to substitute one of the
short-term (e.g., eight days) tests for estimating chronic toxicity of effluents and receiving
• waters (EPA 198538, 198839, 198940). These tests are only suitable for substances that do not
bioaccumulate, however. The species used in the short-term tests also may not be as
appropriate as other available surrogate test species for a species-level assessment. Again,
". Environmental Protection Agency (EPA). 1987. Guidelines for Derivhg Ambient Aquatic Life Adwsory Concentrations. Office
of Water Regulations and Standards, Washington, DC.
'•" Environmental Protection Agency (EPA> 1985. Short-term Methods for Estimating the Chronic Toxicity of Effluents in
Receiving Waters to Freshwater Organisms. Office of Research and Development. Office of Environmental Monitoring and
Support Laboratory, Cincinnati. OH. EPA/600/4-85/014.
'" Environmental Protection Agency (EPA). 1988. Short-term Methods for Estimating the Chronic Toxicity of Effluents in
Receiving Wafers to Marine and Estuaiine Organisms. Office of Research and Development, Office of Environmental Monitoring
and Support Laboratoiy, Cincinnati, OH. EPA/600/4-87/0928.
- Op. Cit. 16.
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F-46 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance _^^
consult with the BTAG to ensure that appropriate procedures are applied to plan and interpret
toxicity tests.
Highlight F-21:
One Approach to Accounting for Varying Species Sensitivities
Use multiple test species and an uncertainty factor. For example, in the context of EPA's
National Pollutant Discharge Elimination System (NPDES) permits program, at least three test
species (one fish, one invertebrate, and one plant) are required41. For toxicity tests on surface
waters, analysis of species sensitivity ranges found in EPA AWQC documents indicates the
following: If the fathead minnow, Daphnia magna, and the bluegill are used for freshwater, the
results for the most sensitive of the three test species divided by a factor of 10 encompasses
the value for the most sensitive animal species most of the time (i.e., for 71 out of 73 chemicals
with data on 4 or more species; Kimerle42).
Biological field surveys Biological field surveys can provide direct or corroborative evidence
of a link between contamination and ecological effects if an appropriate reference area is
surveyed or if a gradient of contamination correlates with a gradient of impacts. The chemical
and biological data need to have been collected simultaneously to determine if a correlation
exists between contaminant concentrations and ecological effects. These surveys usually are
needed only if a detaied ecological assessment is necessary.
F.15 Risk Characterization
Ecological risk characterization is primarily a process of comparing the results of the exposure
assessment with the results of the ecological effects assessment. The purpose is to answer
the following questions:
Are the ecological receptors of concern currently exposed to site contaminants at
levels that can cause adverse effects or is future exposure at such levels likely?
If adverse ecological effects are observed or predicted, what are the types,
extent, and severity of the effects?
What are the uncertainties associated with the risk characterization, and are they
too large to allow decisions on remedial actions and goals?
All information available by the end of the initial sampling phase of the Rl should be used to
screen for potential ecological impacts at the site, both present and future. The potential for
impacts can be evaluated on the basis of several types of information, considering the weight of
evidence provided by each:
Historical information on impacts (e.g., fish kills following snow melts);
Comparing ecological benchmarks with contaminant concentrations in
environmental media (e.g., surface waters, sediments, soils, plant and animal
tissues);
" Environmental Protection Agency (EPA): 1987. Permit Writer's Guide to Water dually-Based Permitting for Toxic Pollutants.
Office of Water Regulations and Standards. Washington, DC. EPA 440/4-87-005.
'•' Kimerle. R.A.. Werner. A.F., and Adams. W.J. 1984. Aquatic hazard evaluation principles applied to the development of
water qudily criteria. In: Caidwell, R.D.. Purdy, R.. and Bahner. R.C. (eds.). Aquatic Toxicology and Hazard Assessment; Seventh
Symposium. ASTM STP 854. Philadelphia, PA: American Society fa Testing and Materials.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment F-47
Guidance
Evidence of bioaccumulation (e.g., tissue residue samples compared with
exposure media);
Toxicity tests on envirorimental media; ^
Results of bblogical surveys of populations and communities compared with
reference areas; and ,
Biomarkers of exposure or effects.
For any of these evaluations, it generally is helpful to delineate and map areas and habitats
within which measured concentrations exceed ecological benchmarks or for which other
evidence indicates the potential for adverse ecological impacts.
In the remainder of this section, we focus on the interpretation of exceedances of benchmark
levels and species-specific risk estimates. These methods are appropriate for most
assessments.
Exceedance of ecological benchmarks
Quotient method. As described earlier, ecological benchmarks are levels of contaminants in
environmental media (i.e., surface waters, soils, sediments, or organisms at various trophic
levels) that represent a threshold for adverse ecological effects. If an ecological benchmark
concentration (BC) is available for the medium sampled (e.g., surface water), one can compare
measured or estimated environmental concentrations (EC) with that BC. This approach, also
known as the quotient method, assumes that adverse effects are unlikely if the EC is lower than
the BC (i.e., EC/BC < 1) and likely if the EC is greater than or equal to the BC (i.e., if EC/BC >
1)43.
Hazard index (HI). A more common situation, however, is for organisms to be exposed to
more than one contaminant simultaneously. In this situation, EPA's Guidelines for the Health
Effects Risk Assessment of Chemical Mixtures can be applied44. In this approach, the sum of
the quotients developed for individual constituents, is compared with 1. If the sum, known as
the hazard index (i.e., HI = EC/BC,), is less than 1, one assumes that ecological impacts are
unlikely. If the hazard index is greater than 1, it is reasonable to conclude that a potential for
impacts exists, and further study may be required45. The HI approach is most appropriate for
substances that exhibit the same mode of action and target the same organs; it can
underestimate risk if two or more chemicals exert synergistic effects.
Concern level (CL). In applying the quotient or HI approaches, consider the degree of
uncertainty associated with both the EC and the BC values and the consequences of falsely
concluding there is no risk when, in actuality, adverse effects are likely. If both the EC and the
BC have been established using conservative procedures (e.g., upper confidence limits on
average values, to encompass a "true" value 95% of the time), then comparing the EC/BC or HI
values to 1 might be appropriate (i.e., there is a very small chance that an actual impact would
be missed). If, however, both the EC and the BC have been established using "average"
values, then the risk assessor must appreciate that the EC/BC or HI could be slightly less than
1 when in fact there is a good chance (e.g., 50%) that adverse effects would occur. In this
" Environmental Protection Agency (EPA). 1988. Review of Ecological Risk Assessment Methods. Office of Policy, Planning
and Evaluation. Washington, DC. EPA/230-10-88-041.
" Environmental Protection Agency (EPA). 1986. Guidelines for the Health Risk Assessment of Chemical Mixtures. Office of
Health and Environmental Assessment, Washington, DC. EPA/600/8-87/045.
" Environmental Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfund: Volume 1 - Human Health
Evaluation Manual. Interim Final. Office of Solid Waste. Office of Emergency and Remedial Response, Washington, DC.
EPA/540/1-89/002.
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F-48 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
case, the risk assessor should establish a concern level lower than 1 based on (1) the degree
of uncertainty and potential biases in the EC and BC estimates and (2) the consequences of
falsely concluding that there are no impacts likely. Given the lack of guidelines on this topic, it
is important to consult with the BTAG when setting a CL.
Exceedance of wildlife toxicity reference values In those cases where species of concern
can be exposed to contaminants from more than one environmental medium (e.g.,
contaminated soils and surface waters) or can be exposed to different levels of contamination in
different parts of their range, it might be appropriate to estimate a daily average contaminant
intake from all sources rather than attempt to develop benchmarks for the environmental media.
Section EPA/SAO/I-39/002. H.14 described.how average potential daily intakes (ADDpot) can be
estimated for wildlife species of concern, and section H.15 described the development of
wildlife toxicity values (TVs). The quotient and hazard index approaches can be used to
compare ADDpots to TVs. The same considerations apply to determining a concern level (CL)
as described above.
Interpretation of exceedances It is important to consider both the spatial and temporal
applicablity of the benchmark when attempting to compare exposure values to toxbity
benchmarks. For example, EPA's AWQC and similar state water quaity standards are
intended to protect aquatic communities, rather than a specified aquatic population. Thus, if
either an acute or chronic water quality benchmark is exceeded at any point in a surface water
body, the aquatic community at that point can be considered at risk of adverse effects. If often
is possible, therefore, to quantify the areal extent of the surface water bodies for which aquatic
communities are likely to be impacted (i.e., areal extent of the criterion exceedance) either for
acute or chronic exposures. Both the degree of exceedance (i.e., potential severity of the
effects) and the areal extent of exceedances are important considerations for evaluating the
significance of the estimated effects.
If any portion of a river exceeds an acute water quality criterion for the protection of aquatic life,
there is some chance that the mobile members of the aquatic community (e.g., larger fish) will
be adversely affected over an area that is larger than the area of exceedance of the criterion.
For example, if a portion of a river regularly exceeds acute criteria, it may not be possible for
fish to traverse the area without suffering adverse effects. This might divide and isolate the fish
populations on either side of the area of exceedance. If anadromous fish used the river, they
might be blocked from successfully reaching their spawning grounds upstream.
The RPM should consult with the BTAG if there are questions on how to interpret benchmark
exceedances.
F.16 Is Additional Assessment Necessary?
F.16.1 Rationale. When the initial assessment is complete, the RPM needs to evaluate
whether the goals of the ecobgical assessment for the site characterization phase of the RI/FS
have been met, or if further site evaluation is warranted. The operative concern is whether
ecological risks at the site are understood sufficiently to be adequately considered in selecting a
remedial alternative or in establishing remedial goals. At enforcement-lead sites, EPA needs to
be able to defend an endangerment finding.
F.16.2 Factors to Consider. Usually, the initial ecological assessment will be sufficient
Sometimes, however, there are problems that require further evaluation. This section identifies
and describes several factors that.may influence whether further site evaluation is warranted.
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
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F-49
ARARs, other statutory requirements, and public concerns. Remedial actions must ensure
that all ARARs and other statutory requirements are met or waived. This may require that risks
to certain types of environments (e.g., Wetlands) or organisms (e.g., endangered species) be
eliminated, reduced, or controlled. Public concern also may be high for particular environments
or species (e.g., local residents, states, or Native American Tribes may be concerned about
trout streams, eagle populations, unique habitats, or other components of nearby ecosystems).
Additional site investigation may be warranted if it is not clear how ARARs, other statutory
requirements, or public concerns will be addressed by each proposed remedial alternative or
cleanup goal.
Ability to link adverse effects to contaminants. EPA must provide sufficient information to
reasonably conclude whether or not adverse effects are likely as a result of releases of
contaminants from the site. However, EPA need not demonstrate a cause-and-effect linkage
between observed impacts and site contaminants. Demonstrating a reasonable likelihood of
risks to sensitive and other environments generally requires:
Sufficient understanding of all contaminant migration pathways (i.e., the steps,
rates, and processes involved in the migration of contaminants from sources
through environmental media to sensitive or other nearby environments);
Reasonably confident measures or estimates of representative environmental
concentrations at each key point in all contaminant migration pathways; and
Sufficient understanding of the types of adverse effects that may be associated
with observed or estimated environmental concentrations.
For some assessment areas, it may be sufficient to demonstrate that releases can result (or
have resulted) in concentrations above ecological benchmark levels, because there is sufficient
information in the scientific literature linking such concentrations to adverse ecological effects.
AWQC are examples of such ecological benchmark levels. For other assessment areas,
toxicity tests and/or other additional investigations may be required to determine whether
observed contaminant concentrations have the potential to result in adverse ecological effects.
For example, ecological benchmark levels may be below analytic quantitation limits, or
contaminants might not be bioavailable.
Most likely remedial alternatives, cleanup goals, or constraints. Additional information
may or may not be needed to select a remedy or to evaluate its effectiveness. For example, it
may be sufficient to demonstrate that a release has resulted in concentrations above AWQC at
the point that contaminants discharge to a surface water body if all of the reasonable remedial
alternatives will prevent future releases to that surface water body. In contrast, more complete
information on the areal extent of contamination above benchmark levels (or above effect levels
in toxicity tests) may be required when remedial alternatives involve removal, treatment, or
capping of contaminated media such as soil or sediment that serve as nonrpoint sources of
contamination (i.e., it may be necessary to delineate the area that needs to be remediated).
Intended post-remediation uses for assessment areas. The level of information that the
ecological risk assessment must provide may depend partially on the intended post-remediation
uses for each assessment area. For example, little or no information on ecological risk may be
required for areas that are to be capped and revegetated for reasons unrelated to ecological
risk (e.g., because of human health risk or other intended use of the land area).
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F-50 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance
F.16.3 Consultation with the STAG. The RPM should provide the BTAG with the results of
the ecological risk assessment. The BTAG, in turn, should be able to determine if additional
field investigations are necessary, and, if so, what investigations are required.
Highlight F-22:
List of Acronyms
ACRs Acute-to-chronic Ratios
AQUIRE AQUatic Toxicity Information REtrieval
ARARs Applicable or Relevant and Appropriate Requirements
AWQC Ambient Water Quality Criteria
BLM Bureau of Land Management
BTAG Biological Technical Assistance Group
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CLP Contract Laboratory Program
DOI Department of Interior
DQOs Data Quality Objectives
EPA Environmental Protection Agency
FS Feasibility Study
FWS US Rsh and Wildlife Service
MRS Hazard Ranking System,
LOAEL Lowest-observed-adverse-effect level
NCP National Oil and Hazardous Substances Contingency Plan
NOAA National Oceanic and Atmospheric Administration
NOAEL No-observed-adverse-effect level
NPDES National Pollutant Discharge Elinination System
NPL National Priority List
OSC On-scene Coordinator
PA Preliminary Assessment
PNRS Preliminary Natural Resource Survey
PRP Potentially Responsible Party
QA/QC Quality Assurance/Quality Control
QSAR Quantitative Structure Activity Relationships
RCRA Resource Conservation and Recovery Act
Rl Remedial Investigation
ROD Record of Decision
RPM Remedial Project Manager
SI Site Investigation
SOW Statement of Work
SSF Species Sensitivity Factor
TRIS Toxics Release Inventory System
TV Toxicity Value
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Risk Assessment Scoping, Problem Formulation, and Additional Risk Assessment
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F-51
Glossary:
Bioaccumulation potential
Contaminant migration pathway
Ecological benchmark level
Ecological receptor
Environmental medium
Hazard index (HI)
A measure of the tendency for chemicals to preferen-
tially concentrate in the tissues of living organisms; two
general measures are the bioconcentration factor
(BCF), the equilibrium ratio of the concentration of a
chemical in the tissue and its concentration in ambient
water, in situations where the organism is exposed
through the water only; and the bioaccumulation factor
(BAF), the equilibrium ratio of the concentration of a
chemical in the tissue to its concentration in an
environmental medium where the organism and the
food chain both are exposed.
The pathway through which a chemical or non-
chemical stressor travels from a source to a specified
habitat, environment, or ecological receptor; the
contaminant migration pathway includes a source, the
environmental medium or media through which the
stressor moves, and one or more receptor(s).
Concentrations in environmental media (e.g., surface
water, sediment, soils) above which potentially
significant adverse effects to ecological receptors are
expected to occur; usually derived from toxicfty values
(e.g., no-adverse-effect levels, lowest-adverse-effect
levels, LCsos) for either acute or chronic exposures.
An individual organism, population, community,
ecosystem, or ecoregion that may be affected by site
contaminants or other stressors.
A component of the environment through which
contaminants can move; includes both abiotic
components (i.e., soil, groundwater, surface water, air,
sediment) and biotic components (e.g., fish, shellfish,
plants).
The sum of the ratios of the estimated environmental
concentration of each contaminant (EC) to its
ecological benchmark level (EB), calculated using the
following formula:
HI =
where
ECj = the concentration for the fh contaminant
EBj = the benchmark concentration for the fh
contaminant
This approach can also be applied to the ratio of
average daily intake of an animal (ADDpot) to a wildlife
reference toxicity value (TV) for more than one
contaminant
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Nearby habitat
Primary consumers
Primary producers
Reference environment
F-52 Appendix F: Risk Assessment Scoping, Problem Formulation, and Additional Risk
Assessment Guidance '
A terrestrial, surface water, or wetland habitat that is
actually or potentially exposed to site contaminants;
nearby environments maybe located anywhere from
on site to several tens of miles from the site.
Organisms that feed primarily on the primary
producers (e.g., plants) at the base of a food chain.
Organisms (e.g., green plants and some bacteria) that
are autotrophic (i.e., fix energy from the sun or use
'". inorganic compounds forfood)and form thebase of a
food chain or web.
A terrestrial, surface water, or wetland environment
that closely resembles the environment of concern in
terms of its bbtic and abiotic composition and structure
and is known not to be exposed to contaminants from
the site.
Organisms (e.g., carnivores, insecth/ores) that feed
primarily on primary consumers.
Environments or habitats that are rare, unique, relic, or
otherwise have state, regional, and/or Federal
significance or special statutory protection.
Any substance that causes an adverse effect (e.g.,
skin lesions, lethality, decreased growth rate, prenatal
mortality) on ecological receptors; stressors may be
chemical (e.g., metals) or non-chemical (e.g., pH,
turbidity, temperature) and may be natural or
anthropogenic.
Any of the feeding levels through which the passage of
energy through an ecosystem proceeds. For
freshwater aquatic systems, this document assumes
that zooplankton are trophic level 2, small fish trophic
level 3, top carnivorous fish trophic level 4.
Secondary consumers
Sensitive environment
Stressor
Trophic level
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APPENDIX G
DETAILED INFORMATION ON MINE
REMEDIATION TECHNOLOGIES
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Appendix G: Detailed Information on Mine Remediation Technologies
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Appendix G: Detailed Information on Mine Remediation Technologies
Table of Contents
G.1 Engineering Controls G-1
G.1.1 Capping and Surface Reclamation G-1
G.1.2 Collection, Diversbn, and Containment G-4
G.1.3 Treatment of Contaminated Water G-5
G.1.4 Extraction and Removal of Waste G-8
G.1.5 Treatment of Solid Wastes G-11
G.2 Constructed Wetlahds G-13
G.3 Bioremediation and Bioreclamation G-14
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Appendix G: Detailed Information on Mine Remediation Technologies
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Appendix G:
Detailed Information on Remediation Technologies __
The following appendix contains information about the effectiveness, feasibility and cost of
remediation at mine sites. Information on capping and surface reclamation comes largely from
EPA's draft RCRA Guidance Document for Landfill Design-Liner Systems and Final Cover
(1982); information on treatment of contaminated water and solid wastes comes from EPA's
Handbook, Remedial Action at Waste Disposal Sites (1985), and the U.S. Army Engineers'
Handbook for Stabilization/Solidification of Hazardous Wastes (1986).
Note that the information presented'tiere on remediation technologies is dated. As new
technologies are devebped and the current technologies are refined the information presented
here, effectiveness, feasibility, and costs, may change. Whenever possible, current sources
should be utilized.
G.1 Engineering Controls
G.1.1 Capping and Surface Reclamation.
The effectiveness of capping as a disposal alternative at mine waste sites will depend on
several site-specific factors, such as the materials and number of layers used, the mobility of
the covered waste, the size and topography of the site. Considerations related to evaluation of
caps against the nine criteria may include the following:
Capping, in the absence of treatment, does not reduce toxicity or volume of the
waste.
Excessive settlement and subsidence of the cap, caused by consolidation of the
waste, can reduce the effectiveness of the cap, including:
Ponding of surface water on the cap;
Disruption of gas collection pipe systems;
Fracturing of low permeability infiltration layers; and
Failure of geomembranes.
Failure of the cap may result in release of the buried waste, such as leaching or
the escape of fugitive dust.
Freeze-thaw effects may, depending on climate, result in the development of
microfractures or other failures that can increase the hydraulic conductivity of
clays by as much as one order of magnitude.
Infiltration layers may be subject to drying depending on the climate and soil-
water retention in the erosion layer.
Fracture and volumetric shrinking of the clay .due to water loss may increase the
hydraulic conductivity of the infiltration layer.
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Appendix G: Detailed Information on Mine Remediation Technologies
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G-2 Appendix G: Detailed Information on Remediation Technologies
Considerations when determining the feasibility of capping may include the folbwing:
Capping can normally be accomplished with conventional construction
equipment and, in some cases, co-site soils. However, the large areas of mine
sites may pose substantial problems.
The slope angle, slope length and overlying soil load may limit the stability of
component interfaces, such as between the geomembrane with the soil. If the
design slope is steeper than the effective friction angles between the material,
sliding instability may occur.
Capping and revegetation, if used, generally can be accomplished in less time
relative to other alternatives. Capping may be widely available, therefore, to
prevent the near-term spread of contamination.
Treatabiiity tests and research may be required to fully characterize the
practicability of capping at the site, prolonging the remedial action. This is
particularly true for revegetation of capped areas, where extensive research and
testing may be required to find effective, long-term solutions.
Coste associated with capping can vary, depending on the materials and size of the cap,
as well as the ancillary equipment (e.g., monitoring wells) that may be required. Some general
considerations may indude:
Capping may have low capital cost in comparison with other alternatives
addressing similar volumes of waste, such as excavation and offsite removal.
Capping may entail bng-term O&M expenses for monitoring and maintenance,
including:
Inspection of the cap for ponding, failure of the cap, or, deterioration of
the vegetatbn;
If run-on or run-off systems are used, inspection and emptying of
containment systems;
Upkeep of the upper vegetative cover (e.g., replacement of eroded soils
or vegetation);
Periodic application of special surface treatments needed to prolong the
life and effectiveness of asphalt or concrete liners (e.g., top soil to
replaced eroded soil);
Sampling of nearby monitoring wells, if used, to detect any leaching; and
Institutional controls preventing unauthorized access that could affect
long-term effectiveness. .
The use of surface vegetation is recommended for both single- and multi-layered soil caps to
provide for stabilization and erosion control, and improve aesthetics. Careful consideration and
research of site-specific factors should be done to determine the types of vegetation chosen for
revegetation. Depending on site conditions, this may include the following activities:
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Appendix G: Detailed Information on Remediation Technologies G-3
Search for potentially suitable vegetation, and sampling and analysis of the site
conditions affecting growth in the area to be reclaimed. The following
parameters may be relevant to consider:
Climate. Seasonal ambient temperatures can affect the plant's
photosynthesis, respiration, and absorption of minerals. Stronger
consistent prevailing winds can, in certain instances, lead to sandblasting
and dislodging of plants and erosion and dehydration of surface tailings
material. Heavy winter snowfalls and heavy spring rains can delay
access to tailings for planting.
Moisture supply. Certain soils, particularly fine soils like sands and
sandy loams, normally exhibit lower moisture-retention than less fine
soils, like loams and days. The moisture needs of the plants should be
compared to the moisture-retention characteristics of the soil.
Soil reaction. pH levels may affect the ability of the vegetation to take
up essential nutrients from the soil, such as phosphates in acid soils.
Highly acidic soils can potentially be high in concentrations of aluminum,
manganese, and iron. Excessively high concentrations can be phytotoxic
for certain kinds of plants.
Nutrient levels. Nutrient levels in the native soils should be compared
with recommended levels for potential vegetation. If native soils do not
provide adequate nutrients, consider soil treatment or importing non-
native soil.
Conduct bench scale or pilot programs of potentially suitable vegetation. For
new vegetation or sites with unfamiliar contaminants, it may be advisable to test
the selected vegetation in a lab or to cultivate the plants on a small scale at the
site to simulate actual revegetation. Results of the program may help determine
the suitability of the tested plants and the necessary conditions for optimal plant
growth.
Select vegetation. Preferably, selection should be based on observation of
similar plants growing in the area under natural conditions. The species selected
also should be highly adaptable to site-specific conditions and be self-supportive
to the greatest extent possible.
For example, the following plants have been shown to be particularly well-suited for the
revegetation of sulphide tailings areas.1
Red or Tall Fescue
Bromegrass
Red Top
1 Brooks. B.W., T.H. Peters and J.E. Winch. 1989. Manual of Methods Used inthe Revegetation of Reactive Sulphide Tailings
Basins. Canada Center for Mineral and Energy Technology, Energy, Mnes and Resources Canada.
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G-4 Appendix G: Detailed Information on Remediation Technologies
G.I.2 Collection, Diversion, and Containment
Examples of CDC methods are the following:
Prevention of run-on: Examples of diversion technologies for surface water
include interceptor trenches, channels, and drains, channel protection, dikes,
and terraces. These technologies divert surface water so that it does not contact
or infiltrate through sources of contamination.
Control of erosion: '-Erosion control technologies reduce sediment loading to
surface waters and help stabilize the land surface, ultimately reducing the spread
of contaminants. Technologies that control erosion include dikes, terraces,
diversion channels, and surface reclamation techniques.
• Collection of water and control of run-off: Collection technologies may
include a network of pipes, drains, channels, and trenches that direct water to a
central location to aid proper water management. Collection technologies collect
diverted or other surface and ground water so that it can be managed properly.
Collected water is often treated in some manner before discharge, often to meet
ARARs.
Determining the potential effectiveness of CDC methods may need to include the following
considerations:
CDC methods, as a rule, do not reduce the volume or toxicity of the wastes, but
are often used in more comprehensive remediation approaches that are
designed to address these concerns, such as on-site treatment or offsite
removal. As such, CDC methods used for temporary storage may involve a
relatively high risk of recontamination if failure occurs. Therefore, careful
evaluation of effectiveness, including contingencies for failure, may need to be
considered. Some of the risk of a release can be abated if the containment of
waste is held to a minimum period of time and the CDC method is used in
conjunction with treatment or removal.
• Most CDC methods are proven and well-documented. A new application of CDC
methods may, however, warrant a treatability study to characterize their
effectiveness in light of the site-specific conditions.
CDC methods can be an effective option in minimizing the generation of acid
mine drainage by diverting run-off from metal-suifide minerals. For example,
slurry retrenching may be used to form a barrier between an aquifer and tailings
piles.
The effectiveness of CDC methods can potentially be influenced by
unforeseeable factors, such as climate (e.g., rainfall flooding), and as such, their
effectiveness over time may be unpredictable and difficult to evaluate. It may be
advisable to identify reasonable factors that might affect performance and
assess the likelihood that effectiveness can be assured.
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Appendix G: Detailed Information on Remediation Technologies G-5
Implementabmty considerations for CDC methods may include the following:
CDC methods can usually be implemented using readily available construction
equipment and materials (e.g., backhoe, low-permeability soils). However, the
site may need to be surveyed to ensure that implementation is possible given
site-specific conditions.
Some CDC methods (e.g., interceptor or diversion dikes and berms) can be
constructed with minimal design requirements, and thus, can be set up quickly
without specialized oversight. However, innovative or more advanced CDC
methods may require extensive design and testing.
CDC methods may not be feasible for addressing large areas, particularly areas
with non-point source water contamination. For example, at Clear Creek
Operable Unit No. 1, source control and containment were deemed infeasible
because the source of discharge from the tunnels was from percolating ground
water entering the mines through fractures, and intersecting veins, tunnels,
shafts, and cross cuts, while little of the source was due to point source
contributions (e.g., the intersection of adits with surface channels).
Cosf considerations for CDC methods may involve the folbwing:
CDC methods are often simple to install (e.g., man-made trenches, earthen
basins, dikes, or berms) and have low capital costs. These costs, however, can
be unpredictable, and may vary with site-specific conditions. For example, the
number of man-made or purchased structures required, local availability of soil
and equipment, and effective design life of the systems may influence O&M
costs.
CDC methods normally entail monitoring and maintenance expenses over their
operating life. Mulching and seeding, for example, is often necessary to prolong
the useful life of certain earthen CDC methods like berms and dikes. Many of
the methods also are subject to erosion forces and may be difficult to maintain
without rip-rap or gravel to protect them. Other CDC methods, such as settling
or seepage basins, require that debris be routinely removed and disposed of in
order to enable optimum operation. The operating costs for CDC methods,
however, still compare favorably to that of waste treatment technologies.
G.1.3 Treatment of Contaminated Water
Precipitation
The effectiveness of chemical precipitation may be governed by the following
factors:
The solubility product of ionic species will influence the rate at which the
metal can be precipitated. The solubility product can be controlled by the
amount of lime added to the solution. Most metals have a particular pH
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G-6 Appendix G: Detailed Information on Remediation Technologies
level at which precipitation is most effective. For waters containing
multiple metals, it maybe necessary to vary the pH level to ensure
precipitation of all metals.
High levels of total dissolved solids can interfere with precipitation and
inhibit settling of solids.
— Oil and grease in the water can inhibit settling of solids by creating an
emulsion that suspends particles.
Metal complexes h the water have a relatively high solubility limit, and
thus precipitation may be inhibited or infeasible.
• The feasibility of chemical precipitation may be influenced by the following
parameters:
— The amount of the precipitating agent affects the solubility of the metals
and should be regulated closely to ensure a high degree of precipitation.
Controlling dosage rates may be particularly difficult for waters with wide
variations in flow rates and quantities of metals.
Precipitation is generally not feasible for very dilute waters. However, in
addition to solar evaporation of solvents, there may be the possibility in a
given situation of subjecting the water to very bw temperatures. Such
treatment, together with agitation, could cause a fine precipitate to form
that could then be removed by gravity or filtration methods. In waste
treatment processes, it would be expected that precipitation, especially
with any crystal growth, would occur chiefly in lagoons or ponds
subjected to solar evaporation.
— The residence time should be closely regulated to ensure a high degree
of precipitation.
— Precipitation chambers that provide for mixing of the water will help to
ensure that the precipitating agent makes contact with the metals and to
promote the settling of the precipitate.
Primary capital purchases for precipitation include a vessel capable of holding
the water for the appropriate residence time, a means of directing the water into
and out of the vessel, and a device to remove precipitated metals. The major
variable cost in precipitation is the lime or other agent added to the solution to
adjust pH and the electrical costs associated with mixing and removal. The
disposal costs for sludges with higher concentrations of metals, or complex
metals, may be higher, as more lime (or other reagent) is normally needed for
effective precipitation.
Clarification
• Clarification can be effective in removing solids (i.e., large or coagulated solids).
Dissolved pollutants and fine particles may not be conducive to clarification.
• The feasibility of clarification can be influenced by several factors, including the
susceptibility of the pollutants to be coagulated and/or settled given a reasonable
residence time, and the flow rate of the water through the settling chamber.
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Appendix G: Detailed Information on Remediation Technologies G-7
The major capital purchases for clarification include a basin or container of
sufficient capacity to hold the water to be treated, a means of directing water in
and out of the settling ch'amSer, and a device to remove settled particles (and, if
applicable, a scum raker). Monitoring devices for residence times and feed rates
may also be advisable. Power costs involved with clarification tend to be
relatively low because it relies heavily on gravity to remove suspended particles.
These settled particles may require treatment and offsite disposal (e.g., RCRA-
characteristic sludges).
Chemical Oxidation
Factors that may influence the effectiveness of chemical oxidation include:
Concentration of oxidizable compounds other than the contaminants of
concern may consume the oxidizing agent, inhibiting the effectiveness of
the oxidizing agent at treating targeted contaminants.
Metal salts may react with the oxidizing agent to form metal peroxides,
chlorides, hypochlorites, and chlorates. These compounds can consume
the oxidizing agent, potentially interfering with treatment of the targeted
contaminants.
Residence time should enable volatilization of organics. Batch feed or
continuous flow systems should be monitored to allow for adequate
residence times.
The feasibility of chemical oxidation may be influenced by the following
parameters:
Amount of oxidant should enable volatilization of targeted contaminants.
Other constituents in the water (e.g., metal salts) may be oxidized by the
oxidizing agent and thereby reduce the amount of the agent available for
the targeted contaminants. The danger of incomplete oxidation is that
more toxic oxidation products could be formed, such as in the case of the
high-strength, complex waste streams.2
Mixing of the oxidizing agent and water is important in ensuring that
contact is made between the oxidizing agent and contaminants.
Optimal pH is important to efficient volatilization and the prevention of
undesirable reaction byproducts.
Varying the amount and type of catalysts can promote oxygen transfer
and enhance.oxidation.
Primary capital purchases include contact vessels with agitators to provide
suitable contact of the oxidant with the waste, storage vessels, chemical
metering equipment, and monitoring equipment.
USEPA. Handbook. 1985. Remedial Action at Waste Disposal Sites. Office of Research and Development.
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G-8 Appendix G: Detailed Information on Remediation Technologies
Neutralization
Neutralization can be effective in adjusting the pH of most waters. An important
consideratbn in its effectiveness is the amount of feed used to treat the water.
Monitoring devices may be necessary to ensure that the appropriate amount of
feed is added to the water to ensure effective neutralization.
The feasibility of neutralization may be influenced by the quality of the water to
be treated. Waters containing high concentrations of toxic chemicals may result
in the production of toxic air emissions. Acidification of waters containing certain
salts, such as sulfide, may also produce toxic emissions. These emissions can
be controlled using covers on the reactor basins or mixers to disperse the heat
from the reactions. Other consideratbns include:
— Lime must be added dry to the water; however, blockage of the feed
system is a common problem associated with dry lime.
— Lime neutralization of sulfuric acid, or of acidic wastes with sulfates or
sulfites, may produce calcium sulfate or sulfite, which have limited
solubilities.
The primary capital purchases for neutralization include compartmentalized
reaction basins, mixers, and a baffle system to regulate inflow and outflow of the
water. The major variable costs include lime or other agent added to the soiutbn
to adjust pH. Disposal costs for sludges resulting from neutralization are
normally higher for more heavily contaminated waters, as more of the
neutralizing reagent is normally needed.
G.1.4 Extraction and Removal of Waste
Factors to consider when removing wastes include:
Recontamination. The RPM must ensure that the extraction and removal
action does not unintentionally recontaminate other areas of the site (e.g., via
environmental transport routes). Fugitive dust in the soil, for example, can easily
be churned into the air through use of heavy constructbn equipment during
extraction and removal, potentially recontaminating downwind areas or posing an
immediate threat to worker safety.
Capabilities of extraction equipment. An important consideratbn in extraction
of mining waste is using the appropriate equipment given site-specific conditions.
Certain types of source problems (e.g., inaccessible mines like pit mines and
underground mines, large piles) may make use of conventional construction
equipment, such as backhoes and dozers, infeasible.
The feasibility of extraction and on-site containment. The RPM should
weigh the costs and benefits associated with keeping the extracted waste on site
using containment and diversion technologies as well as the use of off site
treatment or disposal. In some cases, it may be more practicable to keep the
extracted waste on site pending development of on-site treatment during
subsequent stages of the site remediatbn. If the wastes are treated on site to
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Appendix G: Detailed Information on Remediation Technologies G-9
meet all federal and state ARARs, RPMs could potentially avoid off-site
transportation and disposal costs. ;
Extraction and off-site removal of mining wastes is often accomplished using casting and
loading excavation, hauling excavation, or both. Loading and casting can be accomplished by a
wide variety of conventional equipment and techniques, including the following:
Backhoes, draglines and crawlers -- trenching and excavation of the waste.
Draglines in particular are very suitable for excavating large areas with loosely
compacted soil.
Cranes — to load and cast, or rehandle the waste.
Bulldozers and loaders — removal of miscellaneous fill or soil overburden, or
relocating earth or compacted wastes from unstable surface areas to more
accessible areas for lifting and loading operations. .
Hauling operations are normally accomplished using the following equipment:
Scrapers — excavation for removal and hauling of surface cover material at
large disposal sites or respreading and compacting of cover soils (e.g., as in
capping of excavated area).
Haulers equipped with large rubber tires — transportation of excavated
wastes and soil for on-or off-road hauling. The waste is normally loaded onto
the hauler with backnoes,- draglines, shovels, and loaders.
Pumps — extraction of liquids and sludges from ponds, lagoons, or underground
mines. Pumped wastes are transported to waiting tanker trucks for
transportation.
Dredges — extraction of contaminated sediment from streams, surge ponds, or
other water bodies.
In addition, dust suppressbn measures may be necessary to protect human or environmental
areas or to comply with ARARS (e.g., NESHAPs) during excavation and removal operations.
Available dust suppression measures include:
Watering of areas prior to and during excavation activities;
Placement of tarps or covers over excavated materials;
Use of tarps or covers over truck beds to reduce blowing dust and spillage
during transportation to the waste repository; and
Daily cleanup of all spilled or tracked soils from sidewalks and roadways.
The RPM should ensure that adequate design and operating plans are developed before
commencement of extraction and offsite removal, including:
Operational plans — These plans should identify hot, transition, and cold zones
for site workers, as well as other important areas for extracting and removing the
waste, and include a site worker safety plan and associated contingent
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6-10 Appendix G: Detailed Information on Remediation Technologies
emergency procedures developed with the local hospital and police and fire
departments.
Environmental controls - The lead agency should develop plans to ensure that
the response action is implemented to mitigate any disturbance to the
surrounding environment. Based on the lead agency's determination of
attainable ARARs, for example, the response action may be required to meet
certain location-specific or other ARARs requiring evaluation and mitigation of
any disturbance to the surrounding environment. For example, the Surface
Mining Control Act requires that the removal of contaminated soils use Best
Available Technologies (BAT) to minimize disturbance to wildlife, fish, and the
environment, and include measures to prevent subsequent erosion or air
pollution.
Excavation and removal procedures — An overall strategy should be
developed to ensure successful excavation and removal, such as the provision
of air or soil monitoring equipment, specific procedures for excavation and
removal, and identification of targeted hot spots.
Extraction and offsite removal may be an effective and permanent method of eliminating
contamination at the site. If, however, the removal action is an interim response action and is
intended to address only a specific area or kind of contaminant of concern (e.g., lead-based
fugitive dust in residential soils), the action may not be a comprehensive solution to the site's
contamination. In such cases, the removal actbn may need to be followed by a more
comprehe.nsive remedial approach, such as treatment. Extracted wastes also would pose a
potential for contamination at the ultimate disposal site, unless treated beforehand.
The following consideratfons may be applicable in considering the feasibility of removal actions:
Excavation and offsite removal is applicable to many mine conditions, but may
be impracticable where site-specific features (e.g., remoteness of the
contamination in an underground mine, size of source) make extraction and
offsite removal cost-prohibitive.
Because the extraction and offsite removal of waste can often be implemented
quickly, the option is often appropriate for addressing immediate contamination
during an interim response action, even before site characterization is complete.
Most extraction and offsite removal options utilize conventional construction
equipment and well-proven construction techniques (e.g., use of backhoes or
dozers).
Cosf considerations for removal actions may include the following:
Extraction and offsite removal may reduce long-term O&M expenses (e.g.,
ground-water monitoring) by eliminating or reducing contamination at the site.
The capital costs of excavation and removal may be less expensive than onsite
treatment and disposal. However, as mentioned above, the RPM should
consider storing the excavated waste onsite pending development of onsite
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Appendix G: Detailed Information on Remediation Technologies G-11
treatment during the subsequent remediation phase, potentially avoiding offsite
transportation and disposal gpsts. ; |,
If the extracted waste is not regulated under RCRA Subtitle C, it may potentially
be managed as a Subtitle D waste. If, however, the waste is subject to RCRA
Subtitle C, it may require manifesting, more frequent transportation offsite under
40 CFR Part 262, and disposal in a Subtitle C disposal unit. For such waste, the
costs of the extraction and offsite removal option may be higher.
Large-scale excavation, or excavation of wastes in remote areas of a mine, can
be cost-prohibitive.
The proximity of a licensed landfill or available disposal site should be
considered in evaluating transportation costs
G.I.5 Treatment of Solid Wastes
Vitrification
Determining the feasibility of vitrification may involve the following
considerations:
Vitrification is generally not feasible for volatile metallic compounds or
wastes containing high levels of constituents that may interfere with the
vitrification process.
High concentrations of chlorides and other habgen salts may interfere
with the glass-making process and corrode equipment.
Halogenated organics are not conducive to oxidation during vitrification.
If halogehated organics are present in the waste, sodium chlorides may
exist in the glass. Because sodium chlorides have a low solubility in
glass, they may not be adequately immobilized.
— Certain constituents, such as carbon or other reducing agents, may
interfere with vitrification. These agents tend to reduce the volatilization
temperature of selenium and arsenates.
The energy resources needed for vitrification may be difficult to establish
at a mining site.
The major capital purchases for vitrification include a vitrification furnace, feed
systems, and air emission controls. Operating expenses include the large
energy resources needed to operate the system.
Soil Vapor Extraction
Variable conditions in the soil may influence the implementabilitv of soil vapor
extraction, including the folbwing:
Low permeability soils may hinder the movement of air through the soil,
inhibiting the volatilization of organics. These and other variable
conditions may cause unpredictable or inconsistent removal rates.
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6-12 Appendix G: Detailed Information on Remediation Technologies
High moisture content of the soil may inhibit movement of air in the soil
and thus interfere with volatilization of organics.
Major capital purchases include extraction wells, an air/water separator, a
blower, and a vapor treatment unit.
Distillation
The effectiveness of distillation methods may vary depending on the technology
used:
Batch distillation is particularly applicable to wastes with a high
concentration of volatile organics.
Fractionation is applicable to wastes containing greater than
approximately seven percent organics. Fractionation can be operated to
produce multiple product streams for recovery of more than one organic
constituent from a waste, while generating a relatively small amount of
residue to be disposed.
Steam stripping is commonly used in wastewater treatment, but may also
be applicable to sludges containing volatile organics.
— Thin film evaporation is normally applicable to wastes with greater than
40 percent organics.
Thermal drying is typically effective at treating wastes with greater than
40 percent organics.
The following factors should be considered when determining the feasibility of
distillation:
The vapor-liquid ratio is an important indicator of the potential
effectiveness of distillation. This ratio refers to the relative temperature at
which different contaminants in the waste are distilled. For waste
constituents with the same vapor-to-iiquid temperatures, distillation would
be impossible. Thus, greater vapor-to-liquid ratbs indicate a more
effective distillation.
— The flow of heat through the waste volatilizes the organic constituents.
Less conductive wastes will make distillation more problematic and may
require additional mixing.
— High concentrations of oil and grease may clog steam stripping and
fractionation equipment, thereby reducing their effectiveness.
The primary capital equipmentfor distillation will vary depending on the type of
distillation used, but may include:
— Batch distillation: a feed system and a batch distillation unit consisting of
a steam-jacket vessel, a condenser, and a product receiver.
Fractionation: a reboiter, feed systems, a stripping and rectification
column, and a condenser.
Steam stripping: a boiler, feed systems, stripping column, a condenser,
and a collection tank.
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Appendix G: Detailed Information on Remediation Technologies G-13
Thin film evaporation: steam-jacketed cylindrical vessel, feed systems,
and a condenser. , >,
Thermal drying: batch or continuous dryers and feed systems.
Cyclonic Separation
The following considerations may be applicable when determining the feasibility
of cyclonic separation:
Cyclones may.be feasible for removing solid particles of over five microns
diameter.
Higher cyclone speeds may increase efficiencies, but may also result in
higher operating costs.
The primary capital purchases include feed systems and the cycbne separator.
Solidification, Stabilization, and Encapsulation
These treatment technologies can be effective at treating contaminants in
sludges, soils, and liquids containing inorganic constituents.
Factors that may influence the feasibility of these options include:
High organic content in the waste can interfere with the bonding of waste
materials; an analysis of volatile and total organic carbon may therefore
be necessary.
Wastes that are low in solids (i.e., 15% solids) may require large volumes
of cement or other agent, increasing operating costs and the weight of
the end product.
Oil and grease in the waste should be less than ten percent since these
constituents may weaken the bonds between particles and cement by
coating the particles.
Sulfates may retard settling and cause swelling and sailing.
• The primary capital purchases include mix tanks, feed systems, monitoring
systems, and leachate collection systems, if applicable.
G.2 Constructed Wetlands
The feasibility of wetland treatment may depend in part on the compatibility of
the organic matter with the contaminants. Phytotoxic contaminants may limitthe
kinds of vegetation applicable for use. Depending on the flow rate and residence
time for treatment, an adequate area of land must be available for establishment
of the wetland.
Construction of the wetland may be accomplished with conventional equipment.
Potential O&M costs may include site monitoring (e.g., ground-water monitoring)
and removal and replacement of the organic matter used to absorb the
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G-14 Appendix G: Detailed Information on Remediation Technologies
contaminants. Depending on the contaminants, the organic matter removed
from the wetland may require treatment and disposal under RCRA Subtitle C or
D.
Wetland treatment technology is still evolving. Site managers are encouraged to consult the
latest literature to find out more about current projects.
6.3 Bioremediation and Bioreclamation
• Factors that may influence the effectiveness of biological treatment include:
The ratio of biological oxygen demand to the total organic carbon
content. Waters with low BOD to TOC ratios may not be feasible for
biological treatment.
— High concentration of surfactants on organic matter may create a barrier
between the microbes and organic matter, precluding effective
metabolism.
— Temperature, pH, and residence time must be carefully monitored to
ensure optimal conditions for microbial activity.
Determining the imDlementabilityof biological treatment methods could
potentially depend on the following considerations:
— A minimal quantity of nitrogen and phosphorus are essential for the
synthesis of new cells, white trace amounts of several other elements
such as potassium and calcium, are also needed to satisfy requirements
for microbiai metabolism.
— Waters containing toxic organic matter may require considerably more
care than nontoxic waters. Toxic organics containing chlorine may, for
example, significantly reduce microbial populations and make biological
treatment virtually infeasible. The microorganisms used in biological
treatment can easily be destroyed by shock loading or rapid increases in
the amount of toxic material fed to the process. In such cases, a
considerable period of time may be needed to reestablish an adequate
population of microorganisms to treat the waste.
Capital costs for biological treatment will vary depending on the specific
technology selected. Common capital equipment may include aeration basins,
air supply equipment, piping, and a blower building.
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APPENDIX H
INNOVATIVE TECHNOLOGIES
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Appendix H: Innovative Technologies
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Appendix H: Innovative Technologies
Table of Contents
H.1 Introduction • H-1
H.2 EPA's Technology Innovation Office and Website H-1
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Appendix H: Innovative Technologies'
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Appendix H
Innovative Technologies
H.1 Introduction
Much progress has been made in recent years in the development and application of innovative
technologies in remediating environmental damage. This appendix provides a description of
the following types of technologies concluding with some selected technologies that may be
applicable to mine site cleanups. EPA does not make any representation of these technologies
but has included them as example o'f-available technology. Selected technologies that ate
available include:
Soil and Water Treatment Technologies.
Bioremediation
Chemical Treatment
Soil Washing/Flushing
Solidification and Stabilization
• • Solvent/Chemical Extraction
Thermal Desorption and Thermal Destruction
Vapor Extraction
Remediation Management Practices
Application of Mining and Beneficiation Techniques
Constructed Wetland Remediation
Reclamation
Contamination Prevention
Monitoring and measurement
Several sources are available to gather information about current technologies available. First
among jthese are EPA's Technology Innovation Office (TIO). Most of the information TIO
generates resides on the Agency's C!ean-L)p Information (CLU-IN) home page at
http://clu-in.com. .
H.2 EPA's Technology Innovation Office and Website
The U.S. Environmental Protection Agency, Technology Innovation Office (TIO) was created in
1990 to act as an advocate for new technologies. TIO's mission is to advance the use of new
technologies for characterization and remediation. To accomplish this mission, TIO works in
concert with states, other federal agencies, professional associations and private companies to
create a marketplace with a rich diversity of cost-effective solutions for the Nation's remediation
needs. TIO produces numerous one-time and periodic publications and electronic information
on technologies and markets for soil and ground water remediatbn. TIO strives to provide
information that is relevant to technology developers, academics, consulting engineers,
technology users, and state and federal regulators.
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H-2 Appendix H: Innovative Technologies
CLU-IN is intended as a forum for all stakeholders in waste remediation and contains
information on policies, programs, organizations, publicatbns and databases useful to
regulators, consulting engineers, technology developers, researchers, and remediation
contractors. The site contains technology descriptions and reports as well as current news on
business aspects of waste site remediation and links to other sites important to managers
interested in site characterization and soil and groundwater remediation technologies.
Information on the TIO Website (http://www.epa.gov/swertio1/index.htm) includes:
Site Remediation Technologies: Technologies Encycbpedia, Descriptions, Technology
Selection Tools, Programs & Organizations, Publications
Site Characterization Technologies and Publications
Regulatory Information: Federal Registers, Regulatory Changes
Supply & Demand for Remediation Technologies: Supply of Technologies, Demand for
Technologies, Marketing of Technologies, Publications
Publications and Software: Alphabetical list and an indexed fist of publications and
software organized by subject area.
Other Internet and Online Resource: Related WWW Sites, Other Environmental WWW
Sites, Mailing Lists (Listservs), Electronic Bulletin Boards.
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APPENDIX I
EPA MINING CONTACTS
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Appendix I: EPA Mining Contacts
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Appendix I: EPA Mining Contacts
Table of Contents
1.1 Introduction • '~1
I.2 EPA Headquarters Offices .- • '-2
I.3 EPA Regional Contacts I-4
1.4 EPA Hardrock Mining Team , '-6
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Appendix I: EPA Mining Contacts
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Appendix I
EPA Mining Contacts
1.1 Introduction
This appendix provides a list of contacts at the Environmental Protection Agency who may be
able to provide assistance with concerns at abandoned mining and mineral processing sites.
The first section provides a list of contacts within various EPA Headquarters Offices. The
second section provides a list of contacts at the EPA Regional Offices. The final sectbn
provides a list of the members of the-EPA Hardrock Mining Team.
This list of contacts was developed in 1998 and will change with time.
-------
Appendix I; EPA M Inlng Contacts 1-2
1.2 EPA Headquarters Offices
Name
Shahid Mahmud
Joe Tieger
Steve Hoffman
Clara Mickles
Steve Silverman
Steve Neugeboren
Keith Brown
Jorge Rangel
Elaine Suriano
Address
Superfund Office
US EPA
1235 Jefferson Davis Highway
Arlington, VA 22202
Superfund
US EPA
401 M St.
Washington, DC 20460
Mining Coordinator
Office of Solid Waste
2800 Crystal Drive
Arlington, VA 221 01
Indian Affairs
US EPA
401 M St.
Washington, DC 20460
Office of General Counsel
US EPA
401 M St.
Washington, DC 20460
Office of Compliance
Manufacturing covering mining
US EPA
401 M St.
Washington, DC 20460
NAFTA
US EPA
401 M St.
Washington, DC 20460
Office of Federal Activities
US EPA
401 M St.
Washington, DC 20460
Phone
703-603-8721
703-603-8755
202-260-3104
703-308-8413
202-260-7519
202-260-7629
202-564-7124
202-260-0259
202-564-7162
Fax
703-603-9104
202-260-9007
703-308-8686
202-260-7702
202-260-9459
202-260-0129
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1.2 EPA Headquarters Offices
Name
Dan Weese
Jennifer Sachar
Mary Kay Lynch
"
US EPA
Office of Water - Nonpoint Source Branch 401 M
St.
Washington, DC 20460
Office of Federal Facilities Compiance
US EPA ; .
401 M St.
Washington, DC 20460
Phone
======
202-260-6809
202-260-1389
202-564-2581
Fax
======
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Appendix I; EPA Mining Contacts 1-4
1.3 EPA Regional Contacts
Region
1
2
3
4
5
6
7
Name
Dennis Huebner
Superfund Branch
Ray Basso
New Jersey Superfund Branch
John LaPadula
New York/Carribbean Superfund
Branch
Abraham Ferdas
Superfund Office
Maria ParisiVickers
RCRA Programs Office
Richard Green
Superfund and Emergency Response
Office
Alan Farmer
RCRA Permit and Compliance Branch
Jody Traub
Superfund Division
Norm Niedergang
RCRA Division
Carl Edlund
Superfund Programs Branch
Arnold Ondarzo
RCRA Programs Branch
Rob ert M orby
Superfund Branch
Address
Waste Management Division
1 Congress Street
Boston, MA 02114
Emergency and Remedial Response
Division
290 Broadway
New York, NY 10007-1866
Hazardous Waste Management Division
1650 Arch Street
Philadelphia, PA 19107
Waste Management Division
61 Forsyth Street
Atlanta, GA 30303-3415
Waste Management Division
77 West Jackson Blvd.
Chicago, IL 60604-3507
Hazardous Waste Management Division
Fountain Place
1445 Ross Avenue
Suite 1200
Dallas, TX 75202
Waste Management Division
726 Minnesota Avenue
Kansas City, KS 66101
Phone
617-918-1203
212-637-4109
212-637-4262
215-814-3143..-
215-814-3149
404-562-8651
404-562-8295
312-353-2147
312-886-7435
214-665-8126
214-665-6790
913-551-7682
Fax
617-573-9662
212-637-4439
215-597-9890
215-597-3150
404-347-0076
312-353-9306
312-353-4788
214-665-6660
214-665-7263
913-551-7060
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1.3 EPA Regional Contacts
Region
8
9
10
Name
PaulArell
Superfund Management Branch
Jim Dunn
Carol Russell
Orville Kiehn
Mike Bishop
Keith Takata - Director
Superfund Program
John Hillenbrand
Rich Vaille
NickCeto
Regional Mining Coordinator
Chris Fie Id
Superfund Response and
Investigations Branch- Emergency
Planning
BillRiley
Office of Water Mining Specialist
Sylvia Kawabata
Program Management - Unit Manager
Cindi Godsey
Dave Tomten
Address
Hazardous Waste Management Division
999 18th Street
Suite 500
Denver, CO 80202-2405
US EPA
Montana Field Office
Helena, MT
Hazardous Waste Management Division
75 Hawthorne Street
San Francisco, CA 94105
Hazardous Waste Division
1200 Sixth Avenue
Seattle, WA 98101
Alaska Operation Office
222 West 7th Ave., #19
Anchorage, AK 99513-7588
Idaho Operation Office
1435 North Orchard Street
Boise, ID 83706
Phone
.. ... . i i iHTT'i i
303-312-6649
303-312-6573
303-312-6310
303-312-6540
406-441-1150
415-744-1730'
415-744-1912
415-744-2090
206-553-1816
206-553-1674
206-553-1412
206-553-1078
907-271-6561
208-378-5763
Fax
--. - - . , „
303-293-1230
415-744-1916
206-553-0124
•flh
206-553-1441
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Appendix I; EPA Mining Contacts 1-6
1.4 EPA Hardrock Mining Team
Region
Name
Address
Phone
Mail Drop
Headquarters Contacts
HQ
HQ
HQ
Ashley Allen
Elaine P. Suriano
Joseph Tieger
USEPA Headquarters
401 M Street, SW
Washington, DC 20460
703-308-8419
202-564-7162
202-564-4276
5306W
2252A
2272A
Regional Contacts
5
6
7
8
9
10
Daneil Cozza
Kathleen Aisling
Pat Costello
James Dunn
Carol Russell
John Hillenbrand
NickCeto
Waste Management Division
77 Jackson Blvd.
Chicago, IL 60604-3507
Hazardous Waste Management Division
Fountain Place
1445 Ross Avenue
Dallas, TX 75202
Waste Management Division
726 Minnesota Avenue
Kansas City, KS 66101
Hazardous Waste Management Division
999 18th Street
Suite 500
Denver, CO 80202-2405
Hazardous Waste Management Division
75 Hawthorne Street
San Francisco, CA 94105
Hazardous Waste Division
1200 Sixth Avenue
Seattle, WA 98101
312-886-7252
214-665-8509
913-551-7939
303-312-6573
303-312-6310
415-744-1912
206-553-1816
WS-15J
6SF-LP
WWPD/RMB
8EPR-EP
80C
WTR-7
ECL-117
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APPENDIX J
INTERNET RESOURCES
-------
Appendix J; Internet Resources
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Appendix J: Internet Resources
Table of Contents
J.1
Introduction J-1
J.2 Environmental Protection Agency Websites J-1
J.2.1 The Office of Solid Waste and Emergency Response (OSWER) J-1
J.2.2 EPA Remedial Technology Information J-2
J.2.3 Other EPA Offices and Data Sources J-3
J.2.4 SLATE (State, Local/and Tribal Environmental Networks) J-3
J.3 Other Federal Agencies J-4
J.3.1 U.S. Department of Energy J-4
J.3.2 U.S. Department of Defense J-4
J.3.3 U.S. Geological Survey J-5
J.3.4 Office of Surface Mining J-5
J.3.5 Bureau.of Land Management J-6
J.3.6 U.S. Forest Service - J-6
J.4.0 State Websites J-6
J.4.1 Colorado - J-6
J.4.2 Montana J-6
J.4.3 Nevada . . . J-7
J.4.4 New Mexico J-7
J.4.5 Utah .. . J-7
J.4.6 Washington • J-8
J.4.7 Florida J-8
J.5 Academic Sites J-8
J.6 Groundwater Sites J-10
J.7 Publications/Journals Sites J-10
J.8 Institutes/Organizations ." J-11
J.9 Other Websites J-13
J.10 Office of Water, Technical Resources Bibliography J-14
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Appendix J: Internet Resources
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APPENDIX J
INTERNET RESOURCES
J.1 Introduction
The purpose of this appendix is to provide the user with information useful to mine site
Cleanups. This includes accessing the Internet to locate data that may be relevant to mine site
remediation activities, information on the technical resources at the Office of Water, and a list of
documents relating to Corrective Action. There is a wealth of information on websites
sponsored by the Environmental Protection Agency, other federal government agencies ,
various state governments, academic institutions, sites pertaining to groundwater, publications
and journals, Institutes an Ogranizations, both public and private).
Each of the website sectbns presents the name, Internet address, and a short descriptbn of
sites containing potentially useful information. The user should note that most of the sites
contain a great deal of information that is not related to remediation but which may be of
indirect interest. Note also that the following list of sites is not comprehensive, but is, rather, a
sampling of the most accessible and useful sites available when this list was prepared.
J.2 Environmental Protection Agency Websites
The EPA homepage provides a map that guides the user to EPA generated information
available on the Internet. Of particular interest to site managers will be the following areas
within the EPA website.
(http://www.epa.gov)
J.2.1 The Office of Solid Waste and Emergency Response (OSWER)
OSWER homepage-provides links to the following offices within OSWER
(http://www.epa.gov/swerrims/index.htm)
Other Wastes - Mining and Oil and Gas Wastes Information about other solid wastes
regulated under RCRA Mining Wastes, Ash and Oil and Gas.
(http://www.epa.gov/epaoswer/osw/other.htm)
Technology Information Office Information about innovative treatment'technologies
to the hazardous waste remediation community. Includes programs, organizations,
publications and othertools for federal and state personnel, consulting engineers,
technology developers and vendors, remediation contractors, researchers, community
groups, and individual citizens.
(http://www.epa.gov/swertio1/index.htm)
Hazardous Waste - RCRA Subtitle C Information, about the hazardous waste program
including identification, generatbn, management and disposal of hazardous wastes.
(http://www.epa.gov/osw/)
Superfund Program - CERCLA Information concerning EPA's program to identify and
clean up abandoned or uncontrolled hazardous waste sites and to recover costs for
parties responsible for the contamination.
(http://www.epa.gov/superfund/)
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J-2 Appendix J: Internet Resources
Underground Storage Tanks Information concerning underground storage tanks
containing petroleum products and other hazardous substances.
(http://www.epa.gov/swerust1/)
Rules and Regulations Federal Register notices concerning EPA's waste programs
are posted daily. In addition, there is a list server available for receipt of these Federal
Register notices daily. Also, links that contain the Code of Federal Regulations (CFR)
and the United States Code (USC).
(http://www.epa.gov/swerrims/rules.htm)
J.2.2 EPA Remedial Technology Information
Technical Information Office/CLU-IN - The Hazardous Waste Clean-up Information
Web Site provides information about innovative treatment technologies to the hazardous
waste remediation community.
(http://clu-in.com/)
Alternative Treatment Technology Information Center (ATTIC) is a comprehensive
computer database system providing up-to-date information on innovative treatment
technologies. ATTIC v2.0 provides access to several independent databases as well as
a mechanism for retrieving full-text documents of key literature. The system provides
information needed to make effective decisions on hazardous waste clean-up
alternatives. ATTIC can be accessed with a personal computer (PC) and modem 24
hours a day, and there are no user fees. Please note, ATTIC access requires the use of
a modem or telnet application within a web browser program.
(http://www.epa.gov/attic)
Treatment and Destruction Branch - conducts bioremediation and thermal and
physical/chemical treatment research. Bioremediation research is focused on using
indigenous microorganisms to degrade hazardous organic chemical contaminants in
soils and sediments. The thermal and physical/chemical treatment research involves the
field-scale evaluation of in-situ and ex-situ vitrification, thermal desorption, soil vapor
extraction, and air stripping.
(http://www.epa.gov/ORD/NRMRL/lrpcd/tdb/)
SITE (Superfund Innovative Technology Evaluation) Program - encourages the
development and implementation of (1) innovative treatment technologies for hazardous
waste site remediation and (2) monitoring and measurement In ttie SITE
Demonstration Program, the technology is field-tested on hazardous waste materials.
At the conclusion of a SITE demonstration, EPA prepares an Innovative Technology
Evaluation Report, Technology Capsule, and Demonstration Bulletin. These reports
evaluate all available information on the technology and analyze its overall applicability
to other site characteristics, waste types, and waste matrices. Testing procedures,
performance and cost data, and quality assurance and quality standards are also
presented.
(http://www.epa.gov/ORD/SITE)
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Appendix J: Internet Resources J-3
Office of Radiation & Indoor Air Radiation Protection Division Remediation
Technology and Tools Center develops guidance for better, faster, and more
cost-effective remedial actions, providing technical support to EPA's Superfund
program, and developing, organizing, and executing Inter-Governmental projects which
foster innovative, effective, and efficient treatment technologies. The Center's main
focus areas include Technology Development, Technobgy Evaluation, Technology
Transfer, and Partner Interaction. This website includes links to past project successes
and public announcements. Access to publication information and other websites is also
included.
(http://www.epa.gov/docs/rpdwebOO)
J.2.3 Other EPA Offices and Data Sources
Office of Research and Development (ORD), is the scientific and technological arm of
the U.S. Environmental Protection Agency (EPA). ORD is organized around a basic
strategy of risk assessment and risk management to remediate environmental and
human health problems. ORD focuses on the advancement of basic, peer-reviewed
scientific research and the implementation of cost-effective, common sense technology.
(http://www.epa.gov/ORD/)
The Office of Water site provides links to a wide variety of information regarding the
nation's surface and groundwater resources. Included in these links are sites related to:
contaminated sediments; ecosystem protection; groundwater protection; monitoring,
data and tods; nonpoint source pollution control; pollution prevention; water quality
models; and watershed management programs.
(http://www.epa.gov/OW/)
EPA - Data Systems and Software provides access to numerous database systems
available for use in understanding the environment. Some of the available systems
include: Comprehensive Environmental Response, Compensation and Liability
Information System (CERCLIS); Resource Conservation and Recovery Information
System (RCRIS); Hazardous Waste Data; and the National GIS Program
(http://www.epa.gov/epahome/Data.html)
EPA National Library Network Program maintains a list of servers providing reference
materials, research documents, and other information for use by RPMs. Sites include a
sorted list of EPA libraries.
(http://www.epa.gov/natlibra/index.html)
The Research Programs site provides information on past, current, and future research
efforts undertaken by the Agency and has links to most of the EPA documents available
on-line.
(http://www.epa.gov/epahome/research.htmSprograms)
J.2.4 SLATE (State, Local, and Tribal Environmental Networks)
(http://www.epa.gov/regional/statelocal/index.htm)
State Governments Home Page provides resources to State Governments involved in
implementing environmental protection programs. This page provides a focal point for
State governments to exchange information with EPA and each other.
(http://www.epa.gov/regional/statelocal/)
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J-4 Appendix J: Internet Resources
Local Governments Home Page provides resources to Local Governments involved in
implementing environmental protection programs. This page provides a focal point for
Local governments to exchange information with EPA and each other.
(http://www.epa.gov/regionai/statelocal/)
The American Indian Environmental Office (AIEO) coordinates the Agency-wide
effort to strengthen public health and environmental protectbn in Indian Country, with a
special emphasis on building Tribal capacity to administer their own environmental
programs.
(http://www.epa.gov/indian/)
Drinking Water and Health Fact Sheets: The U.S. EPA Office of Groundwater and
Drinking Water has introduced fact sheets about chemicals that may be found in some
public or private drinking water supplies. These chemicals may cause health problems if
found in amounts greater that the health standard set by the U.S. EPA. The consumer
version of the fact sheet describes the chemical and how it is used, why the chemical is
being regulated, what the health effects are, how much is released into the environment,
and several other important facts about the chemical, The technical version of the fact
sheets contains similar information plus the chemical and physical properties, trade
names for the chemical and other regulatory information. The versions currently
available include consumer versions for inorganic chemicals and technical versions for
synthetic organic chemicals.
(http://www.epa.gov/OGWDW/dwhintro.html)
J.3 Other Federal Agencies
J.3.1 U.S. Department of Energy
Environment, Safety and Health InfoCenter: Combining information technology and
services, the Office of Information Management seeks to facilitate access to quality
environment, safety and health information. Through the ES&H InfoCenter, an
experienced research staff provides multi-media access to Federal, industry and
international informatbn sources.
(http://tis-hq.eh.doe.gov/)
Labs and Facilities Servers site provides a list of links to all the laboratories, sites, and
facilities maintained by the Department of Energy.
(http://WWW.DOE.GOV/html/servers/labtitls.html)
J.3.2 U.S. Department of Defense
Defense Environmental Network & Information exchange (DENIX):: Provides the
general public with timely access to environmental legislative, compliance, restoration,
cleanup, safety & occupational health, security, and DoD guidance information.
Information on DENIX is updated daily and can be accessed through the series of
menus, the site map, or via the DENIX full-text search engine.
(http://denix.cecer.army.mil/denix/Public/public.html)
Library: A shared library of environmental information covering compliance, restoration,
pollution prevention, natural & cultural resources, occupational safety & health, pest
management, environmental planning, etc.
(http://denix.cecer.army.mil/denix/Public/Library/library.html)
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Appendix J: Internet Resources J-5
Environmental Security Programs: Environmental program information includes:
international activities, pollution prevention, conservation, compliance,
cleanup/installation restoration, education & training, safety & occupational health, and
program integration.
(http://denixcecer.army.mil/denix/Public/ES-Programs/env-sec.html)
J.3.3 U.S. Geological Survey
U.S. Geologic Survey Mine* Drainage Interest Group. The mission of the U.S.
Geological Survey (USGS) Mine Drainage Interest Group (MDIG) is to promote
communication, cooperation, and collaboration among USGS scientists working on
problems related to mining and the environment. The group is interdisciplinary and
includes members from all three program divisions of the USGS: Water Resources,
Geologic, Biological Resources, and National Mapping,
(http://water.wr.usgs.gov/mine/)
Natural Resources Theme Page: USGS activities in the natural resources theme area
inventory the occurrence and assess the quantity and quality of natural resources.
Activities also include monitoring changes to natural resources, understanding the
processes that form and affect them, and forecasting the changes that may be expected
in the future.
(http://www.usgs.gov/themes/resource.html)
Environment Theme Area: Information on this site includes studies of natural physical,
chemical, and biological processes, and of the results of human actions. Activities
include data collection, long-term assessments, ecosystem analysis, predictive
modeling, and process research on the occurrence, distribution, transport, and fate of
contaminants as well as the impacts of contaminants on bbta.
(http://www.usgs.gov/themes/envtron.html)
Publications and Data Products: Provides downbadable files, and links to other sites
with information relevant to site remediation, restoration, and reclamation.
(http://www.usgs.gov/pubprod/)
J.3.4 Office of Surface Mining
Environmental Restoration: All functions that contribute to reclaiming lands affected
by past coal mining practices are included under environmental restoration. The Office
of Surface Mining is developing quantitative on-the-ground measures for performance in
this area. When completed in 1998, statistics will be reported that compare
on-the-ground performance with appropriated funding.
(http://www.osmre.gov/osm.htm)
Technology Development and Transfer: The Office of Surface Mining provides
assistance to enhance the technical skills states and Indian tribes needed to operate
regulatory and reclamation programs.
(http://www.osmre.gov/tech.htm)
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J-6 Appendix J: Internet Resources
J.3.5 Bureau of Land Management
Information on this site includes BLM state office, strategic plan, public contact, 98 fiscal budget
and calender of events. It provides updated information concerning surface management
regulations. (http://www.blm.gov)
J.3.6 U.S. Forest Service
This site contains information about all aspects of the U.S. Forest Service. Information in areas
of software applications, databases, forest health, forest issues, and upcoming events are
available on this site. A directory of-contacts is also available.
(http://www.fs.fed.us)
J.4.0 State Websites
J.4.1 Colorado
Colorado Department of Public Health and Environment (CDPHE). This site
provides information on Colorado hazardous waste regulations and programs, including
research documents. Also contains a list of links to other sites of interest.
(http://www.state.co.us/gov_dir/cdphe_dir/hm/)
Division of Mining, Mine Safety, and Mined Land Reclamation: Contains links to the
Colorado Mined Land Reclamation Board, Coal Regulatory Program Office of Active and
Inactive Mines, and the Minerals Regulatory Program
(http://www.dnr.state.co.us/geology/)
J.4.2 Montana
Remediation Division, Montana DEQ: The Remediation Division is responsible for
overseeing investigation and cleanup activities at state and federal Superfund sites;
reclaiming abandoned mine lands; implementing corrective actions and overseeing
groundwater remediation at sites where agricultural and industrial chemical spills have
caused groundwater contamination. Contains links to the Mine Waste Remediation
Bureau, and Hazardous Waste Remediatbn Bureau, were not functional at the time of
publication. (http://www.deq.mt.gov/rem/index.htm)
Remediation Division - Information Systems: The Division maintains two information
systems of potential interest to RPMs. The: Superfund Site Tracking System (SSTS) -
contains information relating to the 278 Montana Superfund sites, including locational
information, contaminant information, and agency action information. The Clark Fork
Data Management System (CFDMS) serves as a point of assimilation for all
chemical/physical/biological analytical information relating to the Upper Clark Fork River
Basin. The CFDMS is closely associated with the Natural Resource Information System
(NRIS) Geographic Information System (GIS), located at the Montana State Library.
(http://www.deq.rnt.gov/rem/infosys.htm)
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Appendix J: Internet Resources J-7
J.4.3 Nevada
Nevada Department of Environmental Protection, Department of Conservation and
Natural Resoruces: This page is the homepage for the state agencies reponsibie for
mining regulation and reclamation.
(http://www.state.nv.us/ndep/)
The Nevada Division of Minerals: The Nevada Division of Minerals administers
programs and activities to further the responsible development and production of
Nevada's mineral resources: minerals produced from mines; geothermal; and oil and
gas. The division regulates drilling operations of oil, gas, and geothermal wells;
administers a program to identify, rank, and secure dangerous conditions at abandoned
mines; and manages the state reclamation performance bond pool.
(http://www.state.nv.us/b&i/minerals/)
The Nevada Bureau of Mines and Geology (NBMG): The Nevada Bureau of Mines
and Geology (NBMG) is a research and public service unit of the University of Nevada
and is the state geological survey. NBMG is part of the Mackay School of Mines at the
University of Nevada, Reno. NBMG scientists conduct research and publish reports on
mineral resources, engineering geology, environmental geobgy, hydrogeology, and
geologic mapping. Current activities in geologic mapping and mineral resources include
detailed geologic mapping and stratigraphic studies in Nevada, comparative studies of
bulk-mineable precious-metal deposits, geochemical investigations of mining districts,
metallic and industrial mineral resource assessments, igneous petrobgic studies,
hydrothermal experiments, and research on the origin of mineral deposits.
(http://www.nbmg.unr.edu/)
J.4.4 New Mexico
Bureau of Mines and Mineral Resources: The Bureau is non-regulatory, and serves
as the state geological survey to conduct studies and disseminate information on
geology, mineral and energy resources, hydrology, geobgic hazards, environmental
problems, and extractive metallurgy.
(http://geoinfo.nmt.edu/)
Mining and Minerals Division: The Mining and Minerals Division is responsible for
implementing the programs which regulate and support development of mining
operations in New Mexico. The divisbn also works on safeguarding abandoned mines
which pose a danger to people or the environment. Publications are produced by the
division which provide information on the mining industry and permitting requirements
for development of mining in New Mexico.
(http://www.emnrd.state.nm.us/mining/)
J.4.5 Utah
Division of Environmental Response and Remediation contains information on
Underground Storage Tanks, Superfund and Emergency Response.
(http://www.eq.state.ut.us/eqerr/errhmpg.htm)
Division of Water Quality provides information regarding the quality of Utah's lakes
and rivers, water quality permitting and regulations.
(http://www.eq.state.ut.us/eqwq/dwq_home.ssi)
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J-8
Appendix J: Internet Resources
J.4.6 Washington
Washington State Department of Ecology: Links to information on site cleanup
responses, standards, and regulations; watershed assessments; environmental reviews;
hazardous waste sites; and State initiatives. Also contains links to other sites.
(http://vyww.wa.gov/ecology/)
J.4.7 Florida
Florida Department of Environmental Quality: The mission of Florida's DEQ protect
public health and the environment through promotion of waste management practices
that minimize waste generation, encourage reuse and recycling, ensure proper
management of generated waste, prevent discharges of chemicals and petroleum
products contained in storage tank systems, and ensure adequate and timely cleanup of
the environment from contamination caused by discharges of hazardous substances
and petroleum products.
(http://www2.dep.state.fl.us/waste/)
J.5 Academic Sites
Information on Laurentian University Mining and Environment Databases: It has
been developed at Laurentian University Sudbury Ontario, and contains 13,000 journal
articles, books and government reports on mining reclamation. Topics include
abandoned mines and land use planning, land reclamation, acid mine drainage,
leaching, sulphide-based tailings, design and costs, mine closure techniques, and a
wide variety of other related topics.
(http://laurerttian.ca/www/library/medlib.htm)
Remediation and Restoration at UCLA's Center for Clean Technology. The mission
of the Center for Clean Technology's thrust in the area of remediation and restoration is
to discover and develop efficient remediation technologies that can achieve acceptable
levels of risk and cost for both mankind and the environment.
(http://cct.seas.ucla.edu/cct.rr.html)
Pacific Institute for Advanced Study. The Environmental Group of the PIAS has
acquired a broad spectrum of technical capabilities in contaminant characterization,
environmental management services, air pollution control using advanced technology
biofiltration, innovative soil washing technologies, design and construction of biopiles
and biofilters, site and ground water bioremediation, environmental policy and planning,
and computer simulation of area migration of contaminants including free phase light
hydrocarbons, multicomponent organic liquids, dissolved transport in unconfined
aquifers and estimating hydrocarbon recovery by in situ vacuum extraction. The
Institute's linkages with a large network of researchers assure that solutions can be
quickly and efficiently found to difficult and/or unusual problems that have resisted
solutions by traditional means.
(http://www.sway.com/~pacific)
Water Resources Research - Environmental Information Systems Laboratory @
McMaster University. Hydrodynamic Pollutant Transport Simulation ~ Education and
Training, Air / Water Interaction ~ GIS and Remote Sensing ~ Municipal Hydraulics,
Surface and Groundwaterflow. Includes extensive book lists and bibliographical lists
with abstracts.
(http://water.eng.mcmaster.ca/home.htm)
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Appendix J: Internet Resources J-9
Arizona State University's Center for Environmental Studies. The Center conducts
research on risk assessment focusing on hazardous materials transportation,
contamination and mitigation; social jmpact assessments; vegetation research focusing
in riparian plant ecology, restoration, and effects of anthropogenic disturbances on
native plant communities; hazard studies.focusing hazardous waste facilities, nuclear
waste policy, soOd and hazardous waste management, emergency management, and
public perception. The site is searchable.
(http://www.asu.edu/ces/)
University of Nevada, The Mlackay School of Mines. Provides information and
expertise in earth science arid engineering. Site provides links to research libraries,
Academic departments, and a number of laboratories and research facilities focused on
Nevada mines and mining issues.
(http://www.seismo.unr.edu/ftp/pub/unr/board.html)
Colorado School of Mines: Colorado School of Mines is a public university devoted to
engineering and applied science related to resources. It is one of a very few institutions
in the world having broad expertise in resource exploration, extraction, production and
utilization which can be brought to bear on the world's pressing resource-related
problems. As such, it occupies a unique position among the world's institutions of higher
education. (http://www.mines.colorado.edu/)
EH Library Bulletin, University of Washington. The online EH Library Current
Contents Bulletin indudes new EH Library acquisitions, on-line information, general
environmental health news, grant information, and news items that review Web sites,
USENET and email groups, and more.
(http://weber.u-washington.edu /-dehlib/textindex.html)
The Research Center for Groundwater Remediation Design, or (RCGRD). The
Center conducts research to reduce the costs, risks, and uncertainties associated with
groundwater systems. Soils, water-saturated aquifers, the unsaturated zone, and
DNAPL are all within the scope of RCGRD's conceptual, computational, and
mathematical research activities. Site is under construction, so data may or may not be
available. (http://www.rcgrd. uvm.edu/)
University of Alabama, Hydrogeology Group. The Hydrogeology Program is actively
engaged in research on a wide range of issues of both scientific and practical
implications on the nation's groundwater resources. Current Research Topics include:
multi-species contaminant fate and transport modeling, simulation-optimization^
framework for remediation design, global optimization approach for parameter
identification; influence of aquifer heterogeneity on groundwater remediation; numerical
simulation of tracer tests at the MADE site; and abnormal fluid pressures in sedimentary
basins. (http://hydro.geo.ua.edu/)
Surfactants Virtual Library at MIT. This site contains links to interesting surfactant
and detergent related websites, with information on surfactant phenomena such as
foaming, detergency, micelles, surface tension, emulsions, microemulsions, as well as
surfactant applications such as cleaning, cosmetics, environmental remediation, etc.
The.library is broken down into the following categories: companies, publishers,
professional societies, conferences, universities and research centers with interfacial
phenomena or surfactant research programs, people involved in surfactant research,
surfactant related articles and abstracts published on the Internet, and surfactant
applications.
(http://www.surfactants.net)
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J-10 Appendix J: Internet Resources
The Hydrogeoiogy program, Stanford University. This site provides limited access to
research on groundwater remediation and research. Current Research Topics include:
aquifer heterogeneity; coupled inversion; geologic simulation; inrwell VOC removal;
optimal aquifer remediation; and rate-limited mass transfer. Contacts and links to other
sites are provided.
(http://pangea.stanford.edu/hydro/)
UIC Thermodynamics Research Laboratory. This site provides abstracts of
presentations and bibliography for the following topics: statistical mechanics, equations
of state, phase equilibria arid non-equilibria, asymmetric mixtures characterization,
surface and interfacial properties, solubilities in liquids and supercritical gases.
(http://www.u|c.edu/~mansoori/TRL_html)
J.6 Groundwater Sites
THE GROUNDWATER REMEDIATION TECHNOLOGIES ONLINE RESOURCE
GUIDE. The purpose of this guide is to present a selection of online resources that
describe the methods, designs, and effectiveness of various groundwater remediation
technologies. Although that is the emphasis of the guide, many of the resources
mentioned herein wii be useful for researching other matters peripheral to groundwater
remediation. Resources include references to web sites; electronic bulletin boards, file
servers, subscriber services, and newsgroups.
(http://gwrp.cciw.ca/lnternet/online.html)
Mine,Environmental Neutral Drainage Program (MEND): Acidic drainage is the
largest single environmental problem facing the Canadian mining industry today.
Technologies to prevent or substantially reduce acidic drainage from occurring in waste
rock piles and tailings sites, and on walls of open pits, need to be developed and
proven. These new technologies will substantially reduce the long term financial
liabilities facing public agencies at abandoned mine waste sites. In response to this
need, in 1989, the M'ne Environment Neutral Drainage (MEND) program was
established in Canada to initiate and co-ordinate research efforts. Because of special
technical needs concerning large waste rock piles, a compatible research program was
established in British Columbia, the BC Acid Mine Drainage Task Force.
(http://www.nrcan.gc.ca/mets/mend/)
The Water Librarians' Home Page. This page contains links to resources that
developed by a librarian in a California water agency. Topics include: water agencies,
water reference databases, comprehensive water pages, water mailing lists; science
and technology: earth sciences, engineering, environmental science; and law and
government agencies.
(http://www.wco.com/~rteeter/waterlib.html)
J.7 Publications/Journals Sites
Journal of Soil Contamination. This journal provides access to publications of the
Association for the Environmental Health of Soils (AEHS). It provides a link between the
association's membership and those disciplines concerned with the technical,
regulatory, and legal challenges of contaminated soils. The journal will be a quarterly,
internationally peer-reviewed publication focusing on scientific and technical information,
data, and critical analysis in analytical chemistry, site assessment, environmental fate,
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Appendix J: Internet Resources J-11
environmental modeling, remediation techniques, risk assessment, risk management,
regulatory issues, legal considerations a subscription is required to obtain copies of the
journal. (http://www.crcpress.com/jour/sss/soilhome.htm)
The Northern Miner: a weekly newspaper covering the activities of North
American-based mining companies wherever they are working. Content includes
exploratbn results, onsite reports, company profiles, international projects, property
acquisitions, mergers, joint ventures, mine development, stock market activity, complete
mining stock table listings and more. Each week our editorial team reports on the latest
North American and international developments from such mining hot spots as Chile,
Argentina, Peru, Mexico, North America, Australia and Africa. Our reporters have
experience in the mining business and know what's important for readers. Our team
includes geologists, mining engineers and seasoned editors.
(http://www.northernminer.com)
The Mining Journal: The Mining Journal Ltd is one of the world's leading mining and
related construction industry publishers. We have a wide range of publications, many of
them leaders in their own particular field, a management consultancy division, and also
one of the most comprehensive company and mining databases available. All of our
products and services are written, edited and managed by experts from the mining,
metallurgical, geological and construction industries.
(http://www.mining-journal.com/mj/)
EPP Publications specializes in the fields of land contamination and reclamation,
property development, waste and recycling, and environmental law and policy. Reports
must be ordered, and each report must be purchased. This site provides a short
abstract of papers that can be ordered, and subscription information to the various
journals they publish.
(http://www.btinternet.com/~epppublications/)
Soil and Groundwater Cleanup Online Magazine. This site provides back issues of
their magazine. Items of interest include information on: bioremediation; groundwater;
in-situ technologies; ex-situ technologies; mixed wastes; site assessment; innovations;
industry links; and news on new state and federal regulations.
(http://www.sgcleanup.com/)
J.8 Institutes/Organizations
Eastern Oregon Mining Association: Eastern Oregon Mining Association (EOMA) is a
nonprofit organization representing and advocating for the role of mining in the Pacific
Northwest. Its membership is primarily made up of operators of small mines,
prospectors, and others interested in mining. EOMA is dedicated as well to the
preservation of American mineral independence and proper stewardship of the
environment. Headquartered in Baker City, Oregon, it has membership from the
Cascades to the Rockies and from Washington to Nevada. It routinely provides
assistance to Oregon state agencies in mining matters, and is in the forefront of policy
making and consultation on multiple use and environmental matters.
(http://www.oregontrail.net/~eoma/)
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J-12 Appendix J: Internet Resources
The Minerals, Metals & Materials Society: Headquartered in the United States but
international in both its membership and activities, The Minerals, Metals & Materials
Society (TMS) is a professional organization ttiat encompasses the entire range of
materials and engineering, from minerals processing and primary metals production to
basic research and the advanced applications of materials. Included among its members
are metallurgical and materials engineers, scientists, researchers, educators, and
administrators from more than 70 countries on six continents.
(http://www.tms.org/)
The Institute of Mining and Metallurgy: The IMM, founded in 1892, is a
professional/learned body for engineers in the minerals industry and has its headquarters
in London, UK. The IMM is a member of the Council of Mining and Metallurgical
Institutions and of Eurominerals, and is a nominated body of the Engineering Council.
The aims of the IMM maybe summarized as: To advance the science and practice of
operations within the minerals industry; To acquire, preserve and communicate
knowledge of the industry. The IMM supports the professions involved with most sectors
of the industry and technical disciplines include exploration, engineering and mining
geology, mining engineering, petroleum engineering, mineral processing and extractive
metallurgy as well as health and safety, management and environmental aspects of the
industry.
(http://www.imm.org.uk)
The National Mining Association: The National Mining Association (NMA) is the voice
of one of America's great basic industries- mining. It was created in 1995 as a result of
the merger of two major organizations representing the mining industry at the national
level: the National Coal Association and the American Mining Congress. While NMA is a
relatively new organizatbn, its predecessor organizations have a long history and
tradition. The National Coal Association was founded in 1917 and the American Mining
Congress was founded in 1897.
(http://www.nma.org/)
The Gold Institute: The United States is the world's second largest gold producer,
capable of meeting all of its domestic gold needs, while exporting 36% of its production.
While gold is widely used in jewelry and as a store of value, its importance has
increasingly derived from a combination of properties that makes it vital to some of our
most advanced technologies.
(http://www.goldinstitute.com)
American Institute of Mining, Metallurgical and Petroleum Engineers: AIME was
founded,in 1871 by 22 mining engineers in Wilkes-Barre, PA. Just as when it was
founded, the goal of AIME today is to advance the knowledge of engineering and the arts
and sciences involved in the productbn and use of minerals, metals, materials and
energy resources, while disseminating significant developments in these areas of
technology.
(http://www.idis.com/aime/)
Northwest Mining Association: NWMA is a regional association representing our
members throughout the United States and Canada. NWMA serves in the role of the
state mining association for Oregon and Washington, working closely with sister
organizations representing the aggregate industry. We also work closely with the
National Mining Association, state mining associations in the western United States, as
well as provincial and regional mining associations throughout Canada.
(http://www.nwma.org)
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Appendix J: Internet Resources J-13
The Society for Mining, Metallurgy and Exploration, Inc.: a member society of AIME
- is an international, nonprofit association of some 17,000 professionals working in the
mineral industries. SME members have the technical expertise acquired through training
and experience and the innovative ability to enhance their industry.
(http://www.smenet.org/)
Rocky Mountain Mineral Law Foundation: Organized in 1955, the Rocky Mountain
Mineral Law Foundation is an educational organization which studies the legal issues
surrounding mineral and water resources. The Foundation encourages the scholarly and
practical study of the law relating to oil and gas, mining, water, public lands, mineral
financing and taxation, land use, environmental protection, and related areas. Its
programs include institutes, shortcourse.s, and workshops in various U.S. and Canadian
locations; the development and publication of treatises, books, forms, substantive
newsletters, and specialized multi-volume looseleaf services; the administration of
scholarships and research grants; and programs for natural resources law teachers.
(http://www.rmmlf.org/)
Nevada Mining Association: This site contains a newsletter on materials in the mining
industry.
(http://www.nevadamining.org)
American Academy of Environmental Engineers. This site provides information on
most aspects of environmental engineering. Contains an online list of publications
relating to site remediation, pollution control, pollution prevention, and other environmental
engineering topics.
(http://www.enviro-engrs.org/)
J.9 Other Websites
Waste Prevention World: The California Integrated Waste Management Board's Waste
• Prevention World site focuses on "doing more with less". It's about efficiency and
rethinking daily activities. The site features specific tips on reducing waste at home, in
the business place, and when landscaping. It also offers an online database for a topical
search, as well as recycling coordination information.
(http://www.ciwmb.ca.gov/mrt/wpw/wpmain.hlm)
Mining USA: The staff of Mining Internet Services, Inc. (MISI) is comprised of mining
professionals with many years of engineering and industry experience. MISI was created
solely to provide Internet services tailored to the mining community. We believe that the
Internet is an exciting medium that can be developed into a platform to educate the public
about mining. Our goal is to establish the premier mining home page that will set the
standard for the industry. Therefore, we are offering extremely competitive rates to those
companies and individuals that participate in achieving our goal.
(http://www.miningusa.com/)
INFO - MINE contains some of the most informative mining information on the Internet.
Contents include: a daily news service; publications, technical information; company
profiles; employment opportunities; and more. Some services require a subscription.
(http://www.info-mine.com/)
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J-14 Appendix J: Internet Resources
MINE-NET an information resource for the mining industry providing information on
specific companies; products offered; scientific discoveries; sources of government,
academic, professional publications. Contains some remediation data. The site is
searchable and contains links to other sites.
(http://www.microserve.net/%7Edoug/index.html)
ENVIRO-LINK is a non-profit organization that is dedicated to providing you with the
most comprehensive, up-to-date environmental resources available. Contains some site
remediation information, and-links to many other sites throughout the world.
(http://www.envirolink.org/)
The AI-GEOSTATS Homepage. Provides a searchable bibliography of geo-statistical
information, on-line list of references, and a large list of geo-science publications that
deliver subscriber information and data via e-mail.
(http://curie.ei.jrc.it/biblio/index.html)
The Environmental Health Clearinghouse: The site provides an easily accessible,
free source of information on environmental health effects. The purpose of the EHC is to
help the public get answers to their questions about environmental health and related
issues. The EHC can provide information on an assortment of environmental topics
including worker exposure, hazardous waste sites, chemical spills and releases,
information for schools and students and other environmental health topics. The
Clearinghouse uses environmental health technical information specialists to handle
inquiries and provide online computer searches, mailing NIEHS publications, conducting
research on inquiries, and/or referring the public to appropriate governmental agencies or
to private sector organizations.
(http://www.infoventures.com/e-hlth/)
Pacific Northwest Laboratory Protech Online: The Protech Online Web Site is an
resource for researching innovative groundwater remediation technologies.
(http://texas.pnl.gov:2080/webtech/menu.html)
J.10 Office of Water, Technical Resources Bibliography
The U.S. Environmental Protection Agency's (EPA) Office of Water serves to protect the nations
surface water, groundwater, and drinking water resources. As part of that mission, the Office of
Water has prepared a large number of technical documents relating to the remediation of waters
contaminated by mining wastes. A selection of these documents are provided below.
Two Internet web pages provide a great deal of information related to the protection of water
resources. These include the USEPA Office of Water home page, at:
(http://www.epa.gov/ow)
and Minelnfo, a privately operated resources for individuals interested in the mining industry, at
(http://www.info-mine.com)
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APPENDIX K
LAND DISPOSAL RESTRICTIONS OVERVIEW AND
BIBLIOGRAPHY
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Appendix K: Land Disposal Restrictions Overview and Bibliography.
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Appendix K: Land Disposal Restrictions Overvfew and Bibliography
Table of Contents
K.1 Introduction K-1
K.2 History of the Land Disposal Restrictions K-1
K.2.1 LDR Treatment Standards K-1
K.2.2 LDR Rutemakings K-3
K.3 Bibliography of Selected Documents K-4
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Appendix K: Land Disposal Restrictions Overview and Bibliography
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Appendix K
Land Disposal Restrictions Overview and Bibliography
K.1 Introduction .
The purpose of this appendix is to provide the user with an understanding of RCRA's Land
Disposal Restrictions program and ruiemakings and to present a bibliography of related
documents that may assist the user in evaluating remediation options at Superfund mine sites.
K.2 History of the Land Disposal Restrictions
Hazardous waste managed under the'auspices of RCRA are addressed by a two-part
regulatory strategy. The first involves technical standards for management units and is
intended to ensure that hazardous waste is contained within the units in which it is managed.
Undermining this first part of the strategy, however, is the assumption that land-based units are
incapable of long-term containment. The LDR program grew out of the second piece of the
strategy, which is to treat the wastes going into these management disposal units to ensure that
should containment fail the waste will have little impact on human health and the environment.
In the 1984 Hazardous and Solid Waste Amendments (HSWA) to RCRA, Congress specified
that land disposal of hazardous waste be prohibited unless the waste meets treatment
standards established by EPA. HSWA requires that treatment standards substantially diminish
the toxicity or mobility of the hazardous waste, so that short- and long-term threats to human
health and the environment are minimized.
K.2.1 LDR Treatment Standards
A waste identified or listed as a RCRA hazardous waste becomes subject to LDR when the
Agency establishes treatment levels that the waste must meet before it can be land disposed.
RCRA Section 3004(g) requires that EPA prohibit hazardous wastes from land disposal within
six months of promulgating a new listing or characteristic. Until the Agency does so, however,
newly listed or identified wastes are not subject to LDR and they may continue to be land
disposed. Once EPA promulgates final treatment levels for a waste, handlers must manage it
in accordance with all the requirements of Part 268 and the waste cannot be land disposed until
it meets the treatment level.
Technology-based Treatment Standards: HSWA requires EPA to promulgate treatment
standards that reduce the toxicity or mobility of hazardous constituents so that short-and
long-term threats to human health and the environment are minimized. To implement this
mandate EPA chose to base treatment standards on technical practicability instead of, risk
assessment. To this end, EPA conducts extensive research into available treatment
technologies. Of all the proven, available technologies, the one that best minimizes the mobility
and/or toxicity of hazardous constituents is designated as the Best Demonstrated Available
Technology (BOAT) for that waste. The Agency then establishes-a waste code-specific
treatment standard based on the performance of the BOAT. These LDR treatment standards
are expressed as either concentration levels or required technologies.
Concentration levels--When treatment standards are set as concentration levels,
treatment is not limited to the BOAT used to establish the treatment standard; instead
the Agency uses BOAT to determine what is the appropriate level of treatment for each
hazardous constituent commonly found in the waste. The regulated community may
then use any method or technology (except for impermissible dilution) to meet the
treatment standard. After treatment, waste analysis or application of knowledge must
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K-2 Appendix K: Land Disposal Restrictions Overview and Bibliography
be used to determine if the applicable concentration-based standards in Section 268.40
have been met.
Required Technologies— When a treatment standard is a required technology, that
technology must be used, unless it can be demonstrated that an alternative method can
achieve a level of performance equivalent to the required technology. Whenever
possible, EPA prefers to use numeric treatment standards in order to stimulate
innovation and development of alternative treatment technologies.
Since the physical and chemical composition of a waste significantly impacts the effectiveness
of a given treatment technology, EPA'divided the treatment standard for each waste code into
two categories: wastewaters and non-wastewaters. The Agency defines these two categories
based on the percentages of total organic carbon (TOC) and total suspended solids (TSS)
present in a waste (Section 268.2), since these factors commonly impact the effectiveness of
treatment methods.
Universal Treatment Standards: Use of BDATs to set treatment standards for hazardous
wastes gave rise to an unintended consequence: the numeric treatment standard applied to an
individual hazardous constituent, like benzene, could vary depending on the performance of the
BOAT on each listed or characteristic wastestream that was evaluated (e.g., non-wastewater
forms of the listed wastes FOOSand U019 both require treatment for benzene; however, the
treatment standard originally set for benzene in the spent solvent was 3.7 mg/kg, while the
standard originally set for unused, discarded benzene was 36 mg/kg, an order of magnitude
difference). To simplify the LDR program and eliminate this lack of consistency between
standards, the Agency examined the range of numeric standards applied to each hazardous
constituent found in restricted hazardous wastes. Based on the range, EPA assigned a single
numeric value to each constituent and listed its two treatment standards (wastewater and non-
wastewater) in Sectbn 268.48. These standards are known as the Universal Treatment
Standards (UTS). Applying these universal treatment standards has not changed the
hazardous constituents that must be treated in a particular waste, as only the numeric
standards were amended. As a result, a common constituent found in multiple, different wastes
will nonetheless carry the same numeric treatment level (e.g., treatment standards for FOOSand
U019 non-wastewaters continue to address benzene, but the level for each has been adjusted
to 10 mg/kg).
Creation of the UTS significantly simplifies the process of assigning treatment standards to
wastes that are newly identified or listed in the future. When a new waste contains hazardous
constituents that have already been addressed in the UTS, the Agency will be able to apply the
existing BDAT-based numeric standards for those particular constituents. Constituents not
already included in the UTS can be evaluated individually and then added to Section 268.48.
Hazardous Debris Standards: Section 268.45 contains alternate treatment standards for
manufactured items and environmental media that are contaminated with hazardous waste.
These alternative standards were developed because materials such as rocks, bricks, and
industrial equipment (known generically as debris) contaminated with hazardous waste may not
be amenable to the waste code-specific treatment standards in Section 268.40. Section 268.45
allows an owner/operator to choose among several types of treatment technologies, based on
the type of debris and the waste with which it is contaminated. The alternative treatment
standards for debris can be divided into three categories: extraction, destruction, and
immobilization technologies. When using an alternate debris treatment standard, the waste
handler must ensure that the treatment process meets the design and operating requirements
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Appendix K: Land Disposal Restrictions Overview and Bibliography K-3
established in Section 268.45. In order to be eligible for land disposal, the debris must meet
the specified performance standards in Table 1 of Section 268.45. Once hazardous debris has
been treated according to the specification "bi one of thlse technologies, it may be land
disposed in a hazardous waste unit. If hazardous debris no longer exhibits any characteristic
following treatment with an extraction (e.g., sandblasting) or destruction (e.g., incineration)
technology, it is eligible for land disposal and can be disposed of as nonhazardous or simply
returned to the environment (Section 261.3(f)).
K.2.2 LDR Rulemakings
Due to the large number of hazardous waste codes that existed prior to HSWA, LDR treatment
standards were developed in stages. In HSWA, Gongress set a time frame for the
implementation of treatment standards for ail wastes listed or identified as hazardous on or-
before November 8, 1984. Congress set specific prohibition dates for certain high-risk and
high-volume wastes and established a three-part schedule with specific deadlines for EPA to
develop treatment standards for the remaining listed and characteristic wastes. Wastes
identified subsequent to HSWA are considered newly identified or listed; additional
rulemakings, promulgated in "phases," have since begun to address these new wastes. This
section highlights some especially pertinent parts of those rulemakings and identifies and
explains certain complex areas;
Solvent and Dioxin-containing Waste. The solvent and dioxin-containing wastes were the
first wastes EPA addressed under the LDR program. Congress set a statutory deadline for
EPA to establish treatment standards for these wastes because they are generated either in
high volumes (solvent wastes) or are considered highly toxic (dioxin- containing wastes). The
final rule published November 7, 1.986 (51 FR 40572) established treatment standards for
F001-F005 solvent wastes and F020-F023 and F026-F028 dioxin- containing wastes. The rule
also established the basic framework for the land disposal restrictions program.
California List Waste: A second group of hazardous wastes for which Congress set a specific
LDR deadline is known as the California list as it was compiled from a California Department of
Health Services' program. The California list, effective July 8, 1987, prohibited the land
disposal of liquid hazardous wastes containing certain toxic constituents or exhibiting certain
properties unless subjected to prior treatment (52 FR 25760). The targets of the list included
cyanides, pH, polychlorinated biphenyls (PCBs), halogenated organic compounds (HOCs), and
metals. Certain HOC-containing wastes were also prohibited even when in solid form. As
waste code-specific treatment standards subsequently have been issued, the California list
prohibitions have been superseded by treatment standards specific to the RCRA waste code
addressing the constituent (or property) of concern.
Thirds: Congress required EPA to meet a schedule for establishing treatment standards for
all hazardous wastes identified or listed prior to HSWA. EPA was required to rank the listed
wastes from high to low priority, based on the wastes' intrinsic hazard and volume generated.
High-volume, high-intrinsic hazard wastes were scheduled to be addressed first, while
low-volume, lower-hazard wastes, including characteristic waste, were to have treatment
standards established last. Wastes with treatment standards promulgated in the first portion of,
the three-part schedule are known as First-Third wastes (53 FR 31138; August 17,
1988),foilowed by the Second-Third wastes (54 FR 26594; June 23, 1989), and Third-Third
wastes (55 FR 22520; June 1, 1990).
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K-4 Appendix K: Land Disposal Restrictions Overview and Bibliography
Treatment Standards for Newly-identified or Newly-listed Wastes: HSWA further requires
EPA to establish treatment standards for all hazardous wastes listed or identified after
November 8,1984. EPA is devebping treatment standards for these wastes in phases.
The Phase I rule, the first of these rulemakings, was published in the Federal Register
on August 18, 1992 (57 FR 37194). In addition to promulgating restrictions for certain
new wastes, Phase I finalized the alternative treatment standards for hazardous debris.
The Phase II rule was finalized in the Federal Register on September 19, 1994 (59 FR
47982). This final rule consolidated the exist'mg treatment standards into Section
268.40, created the UTS, and 'promulgated treatment standards for toxicity
characteristic organic wastes, coke by-products, and chforotoluenes.
The Phase III rule was finalized in the Federal Register on April 8,1996 (61 FR 15566
and 15660). These final rules modified treatment standards for reactive wastes and
decharacterized wastewaters, and promulgated new treatment standards for carbamate
wastes and spent aluminum potliners.
The Phase IV rule was published on May 26, 1998 and is important to remediation
efforts at mine sites as it addresses the previously exempt Bevill wastes (i.e., wastes
from mineral processing facilities that were not among the 20 wastestreams retained in
the Bevill exemptbn) and adjusts the treatment standards applicable to wastes that
exhibit the toxicity characteristic for a metal constituent.
K.3 Bibliography of Selected Documents
The following is a bibliography of selected documents published in the dockets supporting Land
Disposal Restrictions (LDR)Best Demonstrated Available Technobgy (BOAT) Phase I through
Phase IV Rulemakings that may provide information on how Universal Treatment Standards
(UTS) can be met at Superfund Mining sites. For ease of reading, the bibliography has been
divided into five sections for documents:
Specific to Toxicity Characteristic (TC) Metals,
Specific to Mineral Processing,
Specific to Treatment Technologies ,
Other BOAT Background Documents (Corrosive Wastes and General), and
Publications by Other EPA Office or Outside Groups Included in the LDR Dockets.
The bibliography also includes the docket-document number, which identifies the docket and is
followed by the document number (i.e., for document num ber F-96-PH4A-S0054, F-96-PH4A is
the docket for the first supplemental Phase IV proposed rule, and -S0054 is the document
number). The rule and its status also is indicated, since information in proposed rule dockets
may not be finalized or may change prior to promulgation.
A review of history helps in understanding the utility of the documents listed. EPA established
treatment standards for Extraction Procedure (EP) metals in the LDR Third Third rule finalized
in 1990. In 1992, EPA established treatment standards for hazardous waste contaminated
debris, including inherently hazardous debris such as lead pipe. Some remedial wastes may be
debris-like and may be subject to debris standards. In 1994, EPA finalized the Universal
Treatment Standards and established standards for electric arc furnace dust (K061). In
establishing the K061 standard and UTS for metals, EPA changed the basis of the BOAT for
-------
Appendix K: Land Disposal Restrictions Overview and Bibliography K-5
many metals to High Temperature Metals Recovery (HTMR). This has not necessarily resulted
in a real change in actual waste treatment technologies,used.
EPA staff confirmed that stabilization remains the most common treatment method for non-
wastewater forms of metal-bearing wastes. Stabilization data appear in documents supporting
the Third Third final rule and the Phase IV proposed and final rule. For wastewater forms of
metal-bearing wastes, various technobgies can be used. These are best described in the UTS
background document for wastewaters and the Phase IV proposed rule background
documents. Debris is addressed as a separate waste form with unique alternative treatment
standards that apply.
None of the BOAT background documents listed in the bibliography are available online.
However, in developing BOAT, EPA uses various sources of data, some of which are available
to the public via the Internet. While not included in the bibliography, two databases are
available through EPA's Alternative Treatment Technology Information Center (ATTIC): the
Treatment Technology Database and the Treatability Study Database. ATTIC is available at
http//:www.epaigov/attic/accessattic.html. Other online sources of treatment technology and
treatability data are available and have been accessed to support LDR rulemakings.
-------
K-6
Appendix K: Land Disposal Restrictions Overview and Bibliography
LAND DISPOSAL RESTRICTIONS (LDR)
BEST DEMONSTRATED AVAILABLE TECHNOLOGY (BOAT)
APPLICATION BIBLIOGRAPHY
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
U.S. EPA/Office of Solid Waste LDR Publications
Specific to TC Metals
F-96-PH4A-
S0054,
F-95-PH4P-
S0285
F-95-PH4P-
S0289
F-94-CS2F-
S0021
Phase IV
First
Supplement
al,
Phase IV
Proposed
Phase IV
Proposed
Phase II
Final
Proposed Best Demonstrated
Available
Technology (BOAT) Background
Document
for Toxicity Characteristic Metal
Wastes
D004-D011, U.S. EPA, with
Attachments
A and B
Metal Treatment Performance Data
From
Comments to the Phase III Proposed
Rule
(Excerpts from Public Comments),
U.S.
EPA, OSW, WTB, with Attachments
A
through G
Memorandum to Lisa Jones, U.S.
EPA,
Regarding Final Report of Treatment
Data
for Nickel-Containing Wastes, From
Radian Corporation, with Attachments
A through J
Provides waste
characterization
data and
information on
treatment
technologies for
developing BOAT
standards for
wastewater and
nonwastewater
forms of the eight
TC metal wastes
(D004-D011)
Contains metals
treatment
performance data
from commenters
on the Phase III
Proposed Rule.
Provides a
compilation of
HTMR treatment
performance data
used to develop
previously
promulgated BOAT
standards for nickel
wastes including
K061, F006, K048-
K052 and F024.
-------
Appendix K: Land Disposal Restrictions Overview and Bibliography K-7
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-94-CS2F-
S0023
Phase II
Final
Memorandum to Lisa Jones, U.S.
EPA,
Regarding Comparison of Chromium
Data,
From Radian Corporation
Contains a
comparison of
waste treatment
data used to
develop proposed
UTSs for chromium
waste with
treatment data
submitted by
Occidental Corp. in
their comment
(CS2P-00143) to
the Proposed Phase
LDR. Includes
treatment
technobgy
information and
performance data
for nonwastewater
chromium wastes
(K061).
F-94-CS2F-
S0024
Phase
Final
Memorandum to the Administrative
Record
for Universal Standards for Metals,
Regarding
the Report on Chromium Treatment
and the Development/Derivation of
the Universal Standard for Chromium,
with Attachments A and B
Provides detailed
discussion of the
HTMR and
stabilization
technologies
specifically for the
K061 rulemaking.
F-95-PH4P-
S0190
F-95-PH4P-
S0275
Third Third
Final
Final Best Demonstrated Available
Technology (BOAT) Background
Document for K031, K084, K101,
K102, Characteristic Arsenic Wastes
(D004), Characteristic Selenium
Wastes (D010), and P and U Wastes
Containing Arsenic and Selenium
Listing Constituents, U.S. EPA [From
Third Third]
Provides treatment
technobgy
information,
performance data,
and explains the
determination of
BOAT for arsenic-
and selenium-
containing wastes:
K031, K084, K101,
K102, D004, D010
and P and U
wastes.
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K-8
Appendix K: Land Disposal Restrictions Overview and Bibliography
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-95-PH4P-
S0274
Third Third
Final
Final, Best Demonstrated Available
Technology (BOAT) Background
Documents for D006 Cadmium
Wastes, U.S., EPA
Contains waste-
specific information,
treatment
technology
information, and
performance data
for cadmium-
containing wastes
(D006).
F-95-PH4P-
S0279
Third Third
Final
Final, Best Demonstrated Available
Technology (BOAT) Background
Documents for Barium Wastes (D005
and P013), U.S. EPA
Contains treatment
technobgy
information and
performance data
for barium-
containing wastes
(D005). Also details
the development of
the treatment
standards for
barium cyanide
wastes (P013).
F-95-PH4P-
S0280
Third Third
Final
Final, Best Demonstrated Available
Technology (BOAT) Background
Documents for Chromium Wastes
D007 and U032, U.S. EPA with
Attachment A and B
Provides treatment
technology
information,
performance data,
and performance
data analyses for
chromium wastes
(D007). Also details
the development of
the treatment
standards for
calcium chromate
wastes (U032).
-------
Appendix K: Land Disposal Restrictions Overview and Bibliography K-9
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-95-PH4P-
S0281
Third Third
Final
Final, Best Demonstrated Available
Technology (BOAT) Background
Documents for D008 and P and U
Lead Wastes, U.S. EPA, with
Attachments A and B
Provides treatment
technobgy
information,
performance data,
and performance
data analyses for
lead-containing
wastes (D008).
Also discusses lead-
containing P- and
U-code wastes and
details the
development of
treatment standards
for these wastes.
F-95-PH4P-
S0282
Third Third
Final
Final, Best Demonstrated Available
Technology (BOAT) Background
Document for Mercury-Containing
Wastes D009, K106, P065, P092,
and U151, U.S. EPA, With
Attachments A and B
Provides treatment
technobgy
information,
performance data,
and performance
data analyses for
the mercury-
containing wastes
K106, K071
(nonwastewaters),
P065, P092, U151,
and mercury TC
wastes (D009).
F-95-PH4P-
S0283
Third Third
Final
Final, Best Demonstrated Available
Technology (BOAT) Background
Document for Silver-Containing
Wastes
Provides treatment
technobgy
information and
performance data
for silver-containing
wastes (D011).
Also discusses
associated silver-
containing P-code
wastes and details
development of
treatment standards
for these wastes.
Specific to Mineral Processing
-------
K-10 Appendix K: Land Disposal Restrictions Overview and Bibliography
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes ait
end of table)
F-96-PH4A-
S0036
Phase IV
First
Supplement
al
Best Demonstrated Available
Technology (BOAT) Background
Document for Mineral Processing
Wastes, U.S. EPA
Contains a review of
several applicable
treatment and
recovery
technologies,
comparative
analysis, and
performance data
for mineral
processing wastes
characteristic for
corrosivity (D002)
and/or reactivity
(D003)
Specific to Treatment Technologies
F-96-PH4A-
S0033
Phase IV
First
Supplement
al
Letter to Anita Cummings, U.S. EPA,
Regarding the Preliminary
Assessment of Available Data on
Metal Recovery Performances, ICF
Inc., including Appendix A: Metal
Recovery Technology Performance
Summaries
Presents
performance data
from recovery of the
14 BOAT metals
from mineral
processing wastes.
Focuses on electric
arc furnace dusts
from steel
production (K061).
Describes what
types of waste
INMETCO's
recovery processes
can handle, i.e.,
K061, K062, F006,
D002, D006, D007,
D001 and other
wastes.
-------
Appendix K: Land Disposal Restrictions Overview and Bibliography K-11
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-96-PH4A-
S0037
Phase IV
=irst
Supplement
al
Profiles of Metal Recovery
Technologies for Mineral Processing
Wastes and Other Metal-Bearing
Hazardous Wastes, U.S. EPA
Contains
information on
characteristics and
performance of 30
metal recovery
technologies.
Provides a
preliminary
assessment of
whether a particular
technology is suited
for a specific waste
(focused on mineral
processing waste).
F-96-PH4A-
S0038
Phase IV
First
Supplement
al
Review Sheets for Literature on Metal
Recovery Technologies for Mineral
Processing Wastes, U.S. EPA
Contains review
sheets for articles
related to mineral
processing.
Specific information
provided includes: if
article is applicable
to mineral
processing wastes;
level of
development of
technology; type of
waste; specific
waste application;
type of process;
metals or other
products recovered;
and if the article
contains generation
or characterization
data on a mineral
processing waste.
F-95-PH4P-
S0256
Phase IV
Proposed
Treatment Technology Background
Document, U.S. EPA, OSW, with
Attachments A through E
Contains treatment
performance data
and treatment
technology
information that may
be used to treat
wastewaters and
nonwastewaters
subject to the LDR.
-------
K-12 Appendix K: Land Disposal Restrictions Overview and Bibliography
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-95-PH4P-
S0259
F-94-CS2F-
S0025
F-94-CS2F-
S0027
F-94-CS2F-
S0030
Phase IV
Droposed
Phase 1 1
Final
Phase II
Final
Phase II
Final
Proposed Data Document for
Characterization and Performance of
High Temperature Metals Recovery
Treatment and Stabilization for Metal-
Bearing Nonwastewaters, U.S. EPA,
with Attachments A through Q
Memorandum to the Administrative
Record for Universal Standards for
Metals, Regarding the Report on High
Temperature Metal Recovery
Processes and Stabilization
Considered in the Development of
Land Disposal Restrictions for K061
Nonwastewaters, U.S. EPA, 1994
Final Data Document for
Characterization and Performance of
High Temperature Meta|s Recovery
Treatment and Stabilization for Metal
Bearing Nonwastewaters, U.S. EPA
Memorandum to the Record,
Regarding HTMR versus
Stabilization, U.S. EPA, 1994
Contains
performance and
characterization
data of HTMR
treatment and
stabiliztion for
metal-bearing
nonwastewaters
including K061,
K062, F006, F024,
K048-K052, K046,
K002, K003, K004,
K006, K031 , D007,
D009, and K106.
Provides detailed
discussion of the
HTMR and
stabilization
technologies
specifically for the
K061 rulemakings.
Presents
characterization
data and treatment
performance data
for metals in the
Universal Standards
Final Rule.
Contains statement
saying that
stabilization of
metals achieves
levels slightly higher
than recovery of
metals via HTMR.
-------
Appendix K: Land Disposal Restrictions Overview and Bibliography K-13
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
Other BDAT Background Documents (Corrosive Wastes and General)
F-93-CS2P-
S0156
Third Third
Final
Final Best Demonstrated Available
Technology (BDAT) Background
Document for Characteristic Ignitable
Wastes (D001), Characteristic
Corrosive Wastes (D002),
Characteristic Reactive Wastes
(D003), and P and U Wastes
Containing Reactive Listing '
Constituents, (Title Page Only)
Contains applicable
treatment
technologies,
characterization,
and performance
data for ignitable
wastes (D001),
corrosive wastes
(D002), reactive
wastes (D003) and
P- and U-code
wastes containing
reactive listing
constituents.
F-94-CS2F-
S0028
Phase II
Final
Final Best Demonstrated Available
Technology (BDAT), Background
Document for Universal Standards,
Volume A: Universal Standards for
Nonwastewater Forms of Listed
Hazardous Wastes, U.S. EPA, July
1994.
Provides rationale
and technical
support including
treatment
technobgy
information and
performance data
for selecting
constituents for
regulation under
UTS and for
developing UTS for
nonwastewater
forms of listed
hazardous waste.
F-94-CS2F-
S0046
Phase
Final
Final, Best Demonstrated Available
Technology (BDAT), Background
Document for Universal Standards,
Volume B: Universal Standards for
Wastewater Forms of Listed
Hazardous Wastes, U.S. EPA, July
1994.
Contains descriptive
text and tables
showing
performance data
for treatment of
metals in
wastewater.
-------
K-14 Appendix K: Land Disposal Restrictions Overview and Bibliography
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-95-PH4P-
S0284
F-92-CD2F-
S0113
F-92-CD2F-
S0118
Phase IV
Proposed
Phase I
Final
Phase I
Final
Draft, Compilation and Examination
of Metai Information, U.S. EPA, with
Attachment A through D
^
•
Memorandum to Mark Mercer
Regarding Information on
Immobilization of Hazardous Debris
and Highly Contaminated Debris,
Radian Corporation, Including
Attachments A through E regarding
organics interferences.
Hazardous Debris Final Rule
Technical Support Document, U.S.
EPA, 1 992, with Attachments A
through C.
Discusses treatment
technologies and
alternative
technologies for
metal wastes (D004
-D011).
Information is also
presented for non-
TC metals such as
antimony, beryllium,
nickel, thallium,
vanadium and zinc.
Contains
information on
immobilization of
hazardous debris
and examples of
highly contaminated
hazardous debris.
Contains detailed
descriptions of each
treatment
technology listed as
BOAT for hazardous
debris and a
description of the
performance
standards
applicable to each
technology.
Publications by Other EPA Offices or Outside Groups Included in LDR Dockets
F-95-PH4P-
S0026
Phase IV
Proposed
Physical/Chemical Treatment
Technology Resource Guide,
EPA/542-B-94-008, U.S. EPA, TiO.
Provides sources of
physical/chemical
treatment
technology
information and
technical assistance
such as bulletin
boards, catalogs,
databases, dockets
and hotlines.
-------
Appendix K: Land Disposal Restrictions Overview and Bibliography K-15
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
F-95-PH4P-
S0222
Phase IV
Proposed
Superfund Innovative Technology
Evaluation Program: Technology
Profiles, Seventh Edition, U.S. EPA,
ORD.
Provides
descriptions of
innovative
technologies and
what waste they
treat (mostly organic
but includes heavy
metals).
F-92-CD2F-
S0061
Phase I
Final
Review of In-Place Treatment
Techniques for contaminated Surface
Soils, Volume 1: Technical
Evaluation, U.S. EPA, OSWER,
OERR, MERL, and ORD.
Presents
information on in-
situ treatment
technologies
applicable to
contaminated soils
less than 2 feet
deep. Includes
treatment of heavy
metals.
F-92-CD2F-
S0062
Phase I
Final
Review of In-Place Treatment
Techniques for Contaminated
Surface Soils, Volume 2: Background
Information for In-Situ Treatment,
U.S. EPA, OSWER, OERR, MERL,
and ORD.
Presents
information on in-
situ treatment of
hazardous waste
contaminated soils.
Information
presented on
monitoring to
determine treatment
effectiveness.
F-92-CD2F-
S0064
Phase
Final
Handbook on In-situ Treatment of
Hazardous Waste-Contaminated
Soils, U.S. EPA, ORD, RREL
Provides an
analysis oiin-situ
treatment of
hazardous waste
contaminated soils.
-------
K-16 Appendix K: Land Disposal Restrictions Overview and Bibliography
Document
No.
Rule/Status
Title
Notes
(Description of
waste codes at
end of table)
Description of Waste Codes
D001
D002
D003
D004
0005
D006
D007
D008
D009
D010
D011
• Characteristic for ignitability
• Characteristic for corrosivity
• Characteristic for re activity •
• Toxicity characteristic (TC) for arsenic
• TC for barium
- TC for cadmium
- TC for chromium
- TC for lead
• TC for mercury
- TC for selenium
- TC for silver
F006 - Treatment sludge from electroplating operations
F024 - Process wastes including distillation residues, heavy ends, tars, and reactor clean-out wastes,
From the productbn of certain chlorinated aliphatic hydrocarbons by free radical catalyzed processes.
K002 - Wastewater treatment sludge from production of chrome yelbw and orange pigments.
K003 - Wastewater treatment sludge from production of molybdate orange pigments.
K004 - Wastewater treatment sludge from production of zinc yellow pigments.
K006 - Wastewater treatment sludge from production of chrome oxide green pigments (anhydrous and
hydrated).
K031 - By-product salts generated in the productbn of MSMA and cacodylic acid.
K046 - Wastewater treatment sludge from manufacturing, formulation and loading of lead-based
initiating compounds.
K04 8-Dissolved air floatation (DAF) float from the petroleum refining industry.
K049 - Slop oil em ulsion solids from the petroleum refining industry.
K050- He at exchanger bundle cleaning sludge from the petroleum refining industry.
K051 -API separator sludge from the petroleum refining industry.
K052-Tank bottoms (leaded) from the petroleum refining industry.
K061 - Emission control dust/sludge from the primary production of steel in electric furnaces.
K062 - Spent pickle liquor generated by steel finishing operations of facilities within the iron and steel
industry (SIC Codes 331 and 332).
K071 - Brine purification muds from the mercury cell process in chlorine production, where separately
prepuriffed brine is not used.
K084-Wastewater treatment sludge generated during the production of veterinary Pharmaceuticals
from arsenic or organo-arsenic compounds.
K101 - Distillation tar residues from distillation of aniline-based compounds in the production of
veterinary Pharmaceuticals from arsenic or organo-
arsenic compounds.
K102 - Residue from the use of activated carbon for decolorization in the production of veterinary
Pharmaceuticals from arsenic or organo-arsenic compounds.
K106 - Wastewater treatment sludge from the mercury cell process in chlorine production.
P013 - Barium cyanide
P065- Mercury fulminate (R,T)
P092- Mercury, (aceto -o) phenyl-
U032 - Calcium chrom ate
U151-Mercury
-------
APPENDIX L
MINE WASTE TECHNOLOGY PROGRAM
-------
Appendix L: Mine Waste Technology Program
(This page intentionally left blank)
-------
Appendix L: Mine Waste Technology Program
Table of Contents
L.1 Introduction L-1
L.2 Information Management , L-1
L.3 Demonstration Projects L-2
Project 1: Remote Mine Site Demonstration L-2
Project 2: Clay-Based Grouting Demonstration L-2
Project 3: Sulfate-Reclucing Bacteria Demonstration L-3
Project 4: Nitrate Removal Demonstration L-4
Project 5: Biocyanide Demonstration L-4
Project 6: Arsenic Oxidatbn L-5
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Appendix L: Mine Waste Technology Program
(This page intentionally left blank)
-------
APPENDIX M
REMEDIATION REFERENCES
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Appendix M: Remediation References
(This page intentionally left blank)
-------
Appendix L
Mine Waste Technology Program (MWTP)
L.1 Introduction
The purpose of this appendix is to provide the user with information and contacts for the Mine
Waste Technology Program (MWTP). This program was created to provide engineering
solutions to national environmental issues resulting from the past practices of mining and
smelting of metallic ores. The MWTP has developed and implemented a program that
emphasizes treatment technology development, testing and evaluation at bench- and pilot-
scale, and an education program emphasizing training and technology transfer. Evaluation of
the treatment technologies focuses on reducing the mobility, toxicity, and volume of waste;
implernentability; short- and long-term effectiveness; protection of human health and the
environment; community acceptance; and cost reduction.
This program was formed through an interagency agreement between the United States
Environmental Protection Agency (EPA) and the Department of Energy (DOE). The program is
being implemented by MSE Technology Applications, Inc. (MSE) of Butte, Montana. Montana
Tech of the University of Montana (Montana Tech) also located in Butte, Montana, currently
provides analytical and computer support to MSE.
L.2 Information Management
As part of MWTP, Montana Tech is documenting mine waste technical issues and innovative
treatment technologies. These issues and technologies are then screened and prioritized in
categories related to a specific mine waste! problem. Technical issues of primary interests are:
Mobile toxic constituents in water, including acid generation issues;
Mobile toxic constituents in air;
Cyanide;
Nitrate;
Arsenic; and
Pyrite.
Waste forms 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 conjunction with the data collection, Montana Tech has prepared a generic quality assurance
project plan that provides specific instructions on how data will be gathered, analyzed, and
reported for aO activities of the MWTP. Features of both the EPA and DOE quality
requirements are incorporated into this plan. Project-specific quality assurance project plans
are developed by MSE; in addition, MSE provides oversight for all quality assurance activities
performed by Montana Tech.
-------
L-2 Appendix L: Mine Waste Technology Program
L.3 Demonstration Projects
As of 1996, MSE had undertaken seven pilot-scale demonstrations of innovative technologies
for remediation of mining waste. Brief descriptions of six of the seven pilot projects follow this
introduction; Project 6, the Pollution Magnet project, was dropped from the MWTP for reasons
related to its similarity with competing technologies that were more developed and had a use
that was non-mining-specific. The demonstrations were chosen after a thorough investigation
of the technical issue is performed, the specific waste form to be tested is identified, and a
sound engineering and cost determination of the innovative technology is formulated.
In addition to the pibt scale programs conducted by MSE, Montana Tech is conducting bench-
or small plot-scale research on several innovative techniques that show promise for cost--
effective remediation of mine waste. One major criteria for these projects is the potential for
scaling to demonstration pibt plants. One example, the Berkeley Pit Innovative Technologies
Project, was initiated to focus on bench-scale testing of remediation technologies to help assist
in defining alternative remediation strategies for EPA's future cleanup objectives for the
Berkeley Pit waters. The Berkeley Pit is an inactive, open-pit copper mine that has been filling
with acidic water since pump dewatering of adjacent underground mines ceased in 1982.
Project 1: Remote Mine Site Demonstration
EPA asked MSE to develop a treatment facility to treat acidic metal-laden water. Due to the
remote nature of some mine sites, this facility must operate for extended periods of time on
water power alone, without operator assistance.
An example of a remote mine site with a point-source aqueous discharge is the Crystal Mine.
Located seven miles north of Basin, Montana, the Crystal Mine was an ideal site for this
demonstration. In addition, the site has 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.
The Remote Site Demonstration Project at the Crystal Mine was to be conducted in the field for
a minimum of 1 year under ai weather conditions. 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. Initial analytical data from the project showed a greater than 90% removal of toxic metals
from the mine drainage. The system was operated and data was collected for 2 years.
Project 2: Clay-Based Grouting Demonstration
Surface and groundwater inflow into underground mine workings becomes a significant
environmental problem when water contacts sulfide ores, forming acid drainage. Clay-based
grouting has the ability to reduce or eliminate water inflow into mine workings by establishing an
impervious clay curtain in the formation. Groundwater 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 groundwater barrier. The Ukrainian
clay-based grouting technobgy was selected for testing and evaluation because it offered a
potentially long-term solution to acid mine drainage problems. , .
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Appendix L: Mine Waste Technology Program . L-3
The project was finalized at the Mike Horse Mine near Lincoln, Montana. This site was selected
because of its geologic characteristics. A major factor in the selection was an identified point-
source inflow from Mike Horse Creek into the mine causing acid drainage that could potentially
be controlled using a grouting technology. Grout injectbn began September 20, 1994, and
was completed November 1,1994.
Approximately 1,600 cubic yards of grout were injected during the initial phase. A second
phase of grout injection was planned for the summer of 1995; however, high water damned up
within the mine caused extensive damage to the mine and to the monitoring stations for the
demonstration. As a result, Phase Two was discontinued.
. Project 3: Sulfate-Reducing Bacteria Demonstration
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 retard or prevent acid generation at affected mine sites. Biological sulfate reduction
is being demonstrated at an abandoned hard-rock mine site where acid production is occurring
with associated metal mobility.
For aqueous waste, the 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.
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 comprised mainly of cow manure 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 7'4-foot level. Acid mine water historically discharged from the portal associated with this
level. Pilot-scale work at the Western Environmental Technology Office (WETO) in Butte was
performed in 1994. The objective of these tests was to determine how well bacterial sulfate
reduction bwers the concentration of metals in mine water at the shaft temperature (8?C) and
pH (3.0).
During 1996, the field demonstration was again monitored on a regular basis. The data
generally demonstrated a decrease in metals concentrations. An increase in metals was
observed during spring runoff; however, the levels decreased when flow rates returned to
normal. Monitoring of the field demonstration will continue for an additional year.
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L-4 Appendix L: Mine Waste Technology Program
Project 4: Nitrate Removal Demonstration
The presence of nitrates in water can have detrimental effects on human health and the
environment. As a result, regulatory agencies have limited the allowable concentration of
nitrates in effluent water. Nitrates may be present in mine discharge water as a result of the
following mining activities: residuals from ammonium nitrate and fuel oil (ANFO) used in
blasting; cyanide breakdown from leaching; and leaching of ANFO contamination from waste
rock. 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. Both,
however, are expensive and generate a concentrated wastestream requiring disposal.
Of the 20 technologies screened, the following 3 showed the most promise in making nitrate
removal more cost effective and environmentally responsible: ion exchange with nitrate-
selective resin; biological denitrification; and electrochemical ion exchange (EIX).
The best solution to the nitrate problem may be some combination of the three technologies
that balances capital costs with operating costs, reliability, and minimization of wastestreams
requiring disposal. Each combination has advantages and disadvantages that will be
addressed during the project. A test process train was developed that is flexible and optimizes
equipment capital white acquiring value-added test data. The demonstration induded the
following innovative technologies: ion exchange combined with biological denitrification for
destruction of the concentrated brine; ion exchange combined with EIX for destruction of the
concentrated brine; biological denitrification as a stand-alone process; and EIX as a stand-
alone process.
The Nitrate Removal Demonstration Project was conducted at the TVX Mineral Hill Mine near
Gardiner, Montana, where a building to house the equipment was constructed. Conventional
ion exchange was used to remove nitrates 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. Of all the technology combinatbns tested,
biological denitrification of concentrated nitrate brine was the most successful at meeting these
goals.
Biological denitrification was performed on both mine water and concentrated brine. This
removal rate met the project goals and was typically greater than 99%. Biological denitrification
of the raw mine was less successful. A removal rate of approximately 50% was typically
achieved.
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 to alleviate the problem, but the size and nature of the particles made filtration
difficult.
Project 5: Biocyanide Demonstration
The primary use of cyanide in the mining industry is to extract precious metals from ores, and
the use of cyanide has expanded in recent years due to increased recovery of gold using heap
leach technologies. Most processes use chemicals to oxidize the cyanide and produce
nontoxic levels of carbon dioxide and nitrogen compounds. These are relatively expensive to
operate.
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Appendix L: Mine Waste Technology Program L-5
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. The 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 is to use a strain of bacteria to destroy cyanide associated with precious metal
mining operations. Another project goal is to develop a reactor design that will best use the
cyanide-degrading effects of the bacteria to destroy cyanide from mining wastewater.
The field demonstration portion of the project is 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.
Actual cyanide mine water was processed through the reactors to study the kinetics of cyanide
degradation. The results from the tests were then used to design the pilot-scale reactors to be
used at the mine. The final process train consists of tanks where both aerobic and anaerobic
cyanide-degrading organisms are grown in large quantities. The bacteria are then pumped to
the reactors for reinoculation. The cyanide solution enters the aerobic first where aerobic
organisms degrade a large portion of the cyanide. The solution then moves through a series of
anaerobic units for further degradation. Finally, an aerobic polishing step removes 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.
Project 6: Arsenic Oxidation
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 (CRC-WMPC) and the Australian Nuclear Science & Technology Organization
(ANSTO) from Lucas Heights, New South Wales, Australia.
Arsenic contamination in water is often a by-product of mining and the extractbn of metals such
as copper, gold, lead, zinc, silver, and nickel. In most cases, it is not economical to recover the
arsenic contained in process streams because there is littie demand worldwide for arsenic.
The small-scale pilot prq'ect 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 arsenic(lll) to
arsenic(V) using dissolved oxygen as the oxidant. The technology provides a method for the
oxidation of arsenic(lll) 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
arsenic(lll) 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 the removal of arsenic(V) from the solution
by using an accepted EPA method, adsorption using ferric iron.
The photochemical oxidation process was very effective at oxidating arsenite to arsenate at
optimum conditions in the batch mode for both the solar tests and the photoreactor tests.
Design problems with the photoreactor unit in the continuous mode, however, 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
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L-6 Appendix L: Mine Waste Technology Program
to correct the problem during the field demonstration were unsuccessful. Modifications to the
baffle system are necessary to prevent further channeling.
For further information on any of these demonstration projects, contact:
MSB TECHNOLOGY APPLICATIONS. INC.
200 Technology Way
P.O. Box 4078
Butte, MT 59702
(406)494-7268
E-mail: mseta@buttenet.com
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Appendix M: Remediation References
Table of Contents
M.1 Introduction
M.2 Groundwater Remediation References
M.3 Cyanide References ,
M.4 Corrective Action References
M-1
M-1
M-1
M-1
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Appendix M: Remediation References
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Appendix M
Remediation References
M.1 Introduction
The purpose of this appendix is to provide the user with a list of references related to EPA's
Groundwater Remediation Program, Cyanide Treatment, and EPA's Corrective Action Program.
M.2 Groundwater Remediation References
Aral, Mustafa M., ed. Advances in Groundwater Pollution Control and Remediation. Dordrecht;
Boston: Kluwer Academic, c1996.
Charbeneau, RandallJ., Philip B. Bedient, Raymond C. Loehr. Groundwater Remediation.
Lancaster, PA: Technomic Pub. Co., c1992.
Gavaskar, Arun R., Permeable Barriers for Groundwater Remediation. Columbus, Ohio:
Battelle Press, 1997.
Gillham, R.W., et al., 1994. "Use of zero-valent metals in in-situ remediaiton of contaminated
ground water." in In Situ Remediation: Scientific Basis for Current and Future Technologies,
Gee, G.W. and Wing, N.R. (Eds.), Battelle Press, Columbus, WA, Part 2, pp. 913-930.
Miller, Richard K. and Marcia E. Rupnow, ed. Survey on Groundwater Remediation. Lilburn,
GA: Future Technology Surveys, 1991.
Mudder and Whitlock 1984. 'Biological Treatment of Cyanidation Waste Waters," Mudder, T.I.
and J.L. Whitlock, in Mineral and Metallurgical Processing, Society for Mining, Metallurgy, and
Exploration, Inc., August, 1984.
Nyer, Evan K. Practical Techniques for Groundwater and Soil Remediatbn. Boca Raton:
Lewis Publishers, c1993.
M.3 Cyanide References
SAIC, "Cyanide Heap Leach and Tailings Impoundments Closure and Reclamation (Draft),"
May, 1993.
Van Zyl, 1988. Introduction to Evaluation, Design, and Operation of Precious Metal Heap
Leaching Projects, Society for Mining, Metallurgy, and Exploration, Inc., D.J.A. Van Zyl, I.P.G.
Hutchinson, and J.E. Kiel, editors, 1988.
Ahsan 1989. "Detoxification of Cyanide in Heap Leach Piles Using Hydrogen Peroxide," Ahsan,
M. Q., et al., in World Gold, proceedings of the First Joint SMA/Austraiian Institute of Mining
and Metallurgy Meeting, R. Bhappu and R. Ibardin (editors), 1989.
M.4 Corrective Action References
Presumptive Remedies: Site Characterization and Technology Selection for CERCLA Sites with
Volatile Organic Compounds in Soils. EPA/540-F-930-48.
Use of Risk-Based Decision-Making in UST Corrective Action Programs. 9610.17
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M-2
Appendix M: Remediation References
Technical Resource Document - Solidification/Stabilization and its Application to Waste
Materials. June 1993. EPA/530/R-93/012.
Soil Screening Guidelines. EPA/5407R-94/101.
Recent Developments for In-Situ Treatment of Metals Contaminated Soils. March 1997.
EPA/542/R-97/004.
Superfund Groundwater Issue: Ground Water Sampling for Metals Analysis Fact Sheet.
EPA/540/4-89/007.
Retech Inc., Plasma Centrifugal Furnace: Applications Analysis Report. EPA/540/a5-91/007.
Emerging Technology Bulletin: Constructed Wetlands Treatment for Toxic Metal Contaminated
Wastes; Colorado School of Mines Fact Sheet. EPA/540/f-92/001.
Miscellaneous Information on Metals Recycling: Catalytic Extraction Processing, Molten Metal
Technology Inc., Report.
Assessment of Environmental Impact of the Mineral Mining Industry Report. USEPA, ORD.
Innovative Technology: Best Solvent Extraction Process Fact Sheet. Dir 9200-253fs. USEPA,
OSWER.
*
Presumptive Remedy for CERCLA Municipal Landfill Sites. EPA/540-F-93-035.
Land Use in the CERCLA Remedy Selection Process. 9355.7-04
A Guide to Principal Threat and Low Level Threat Wastes. 9380-06FS
Subsurface Characterization and Monitoring Techniques: A Desk Reference Guide. 2 vols.
May 1993. USEPA/ORD. EPA/625/R-93/003s.
Engineering Bulletin: In-Situ Soil Vapor Extraction Treatment Report. EPA/540/2-91/006
Engineering Bulletin: In-Situ Steam Extraction Treatment Report. EPA/540/2-91/005
Innovative Treatment Technobgies, Semi-annual Status Report (Forth Edition). EPA/542-r-92-
011.
Risk Assessment Guidance for Superfund Volume I, Human Health Evaluatbn Manual, Part A.
EPA/540/1-89/002.
Risk Assessment Guidance for Superfund Volume I, Human Health Evaluatbn Manual, Part B.
EPA/540/1-89/002.
Risk Assessment Guidance for Superfund Volume I, Human Health Evaluatbn Manual, Part C.
EPA/540/1-89/002.
Risk Assessment Guidance for Superfund Volume II, Environmental Evaluation Manual.
EPA/540/1-89/001.
Best Management Practices for Soil Treatment-Technologies. May 1997. EPA/530-R-97-007.
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