EPA AND HARDROCK MINING:
A SOURCE BOOK FOR INDUSTRY IN THE NORTHWEST AND ALASKA
January 2003
U.S. Environmental Protection Agency
Region 10
1200 6th Avenue
Seattle, Washington 98101
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
TITLE AND DISCLAIMER
Title
Title: EPA andHardrock Mining: A Source Book for Industry in the Northwest and
Alaska
Prepared by: EPA Region 10 with the technical assistance of Science Applications
International Corporation
Date: January 2003
Disclaimer
This document is not intended, nor can it be relied on, to create any rights enforceable by any
party in litigation with the United States. Any mention of company or product name is not to be
considered an endorsement by the U.S. Government or by the Environmental Protection Agency.
This document describes information needed by EPA to evaluate and make regulatory decisions
on hardrock mines; as a result, the document is general in nature and applicants should not view
anything in this guidance as 'mandatory' or prescriptive. A draft of this document was made
available for review by Federal and State agencies, by public interest groups, and by interested
members of the public. EPA then revised the draft and prepared this final document by
addressing those comments as deemed appropriate by EPA. Commenters are identified, and
both comments and EPA responses to those comments, are presented in Appendix J.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
TABLE OF CONTENTS
Section Page
TABLE OF CONTENTS i
LIST OF TABLES ii
LIST OF FIGURES ii
LIST OF APPENDICES iii
1.0 INTRODUCTION 1
1.1 Purpose of this Document 1
1.2 Problem Statement 1
1.3 General Suggestions for Completing the Permitting Process 2
1.4 Organization of this Source Book 4
2.0 INTRODUCTION TO NPDES PERMITTING (CWA SECTION 402) 4
2.1 When is an NPDES Permit Needed? 8
2.2 Technology-based National Effluent Limitation Guidelines 10
2.3 Water Quality Standards and Water Quality-Based Permitting 11
2.4 Storm Water 17
2.5 Information Needs for NPDES Permitting 18
3.0 DISCHARGE OF DREDGED OR FILL MATERIAL TO WATERS OF THE U. S. (SECTION 404)... 20
4.0 THE NATIONAL ENVIRONMENTAL POLICY ACT 22
4.1 EPA's NEPA Role 23
4.2 EPA Requirements for Environmental Review Under NEPA and the CWA 24
4.3 When is an EIS Required? 26
5.0 OTHER AUTHORITIES 28
5.1 Clean Air Act 28
5.1.1 New Source Performance Standards 29
5.1.2 Specific Sources 30
5.2 Endangered Species Act 31
5.3 Resource Conservation and Recovery Act 35
5.4 Coastal Zone Management Act 36
5.5 State Authorities 36
TABLE OF CONTENTS
(continued)
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
6.0 EPA EXPECTATIONS FOR MINING IMPACT ASSESSMENT 39
6.1 Impacts to Surface and Ground Water Hydrology 39
6.1.1 Surface Water Hydrology 40
6.1.2 Ground Water Hydrogeology 43
6.2 Impacts to Water Quality 45
6.2.1 Background and Existing Water Quality 47
6.2.2 Regional Hydrology and Hydrogeology 47
6.2.3 Hydrology of Mines and Waste Facilities 47
6.2.4 Solid Waste and Materials Characterization and Management 48
6.2.5 Wastewater Quality and Management 50
6.2.6 Post-Closure Mine and Waste Facility Water Quality 51
6.2.7 Closure and Reclamation Effects 51
6.3 Impacts to Aquatic Resources 52
6.4 Impacts to Wetlands 54
7.0 REFERENCES 56
LIST OF TABLES
Table 1. Categories of Discharges from Mines 9
Table 2. Industry Sectors and Types of Applicable Limits 40 CFRPart 440 12
Table 3. Selected Definitions and Provisions in 40 CFR Part 440 12
Table 4. EPA Forms Required for NPDES Application 19
Table 5. Overview of Information Needs for NPDES Permitting 20
Table 6. Potential Emission Sources at Mine Sites 30
Table 7. Delegation and Authorization of Federal Environmental Programs
to States in EPA Region 10 37
Table 8. Data Needs for NEPA Review and CWA Permits 41
Table 9. Testing Needs for NEPA Review and CWA Permits 42
Table 10. Preliminary Design Needs for NEPA Review and CWA Permits 43
Table 11. Data Analysis Needs for NEPA Review and CWA Permits 44
LIST OF FIGURES
Figure 1. NPDES Permitting Process 6
Figure 2. Example of Discharge Classification Depending on Wastewater
Source and Management 13
Figure 3A. Informal Consultation Under the Endangered Species Act 33
Figure 3B. Formal Consultation Under the Endangered Species Act 34
LIST OF APPENDICES
A Hydrology
B Receiving Waters
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
C Characterization of Ore, Waste Rock, and Tailings
D Effluent Quality
E Wastewater Management
F Solid Waste Management
G Aquatic Resources
H Erosion and Sedimentation
I Wetlands
J Comments on Draft Source Book
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
1.0 INTRODUCTION
1.1 Purpose of this Document
This 'Source Book' was prepared by the Environmental Protection Agency (EPA) Region
10 to provide guidance on the Clean Water Act (CWA) permitting processes and associated
National Environmental Policy Act (NEPA) environmental review requirements for new metal
mining operations in Alaska, Idaho, Oregon, and Washington.1 This guidance has three specific
purposes. First, it is intended to explain the specific requirements of the CWA as they may
pertain to new mines. It is hoped that a better understanding of EPA's mandates and authorities
will provide a basis for understanding why certain information is often requested as part of the
CWA permitting processes. Second, this document describes the types of information that EPA
Region 10 generally needs to process permit applications and perform environmental reviews in
an efficient and timely manner. By articulating these information needs, EPA hopes that the
mining industry will realize time and cost savings during the permitting process by avoiding
surprises, false starts, and the need for additional gathering and/or analysis of technical data.
Finally, the guidance is intended to promote predictability and consistency within Region 10 to
ensure mine development, operation, and closure occur in an environmentally sound manner.
Given the unique character of each mining operation and the wide variety of environments
in which they may operate, it is impractical for the Region to develop specific detailed
instructions that would apply to all sites. Consequently, this document is general in nature and
applicants should not view anything in this guidance as 'mandatory' or prescriptive. However,
there are several questions that follow naturally from the discussions contained herein and that
will be asked of most applicants. Among the most important are: Will there be a discharge of
wastewater during operations and/or closure? Will the discharge meet water quality standards?
What is the long-term risk of surface and ground water contamination? Will reclamation restore
the integrity of aquatic and terrestrial ecosystems affected by the project? How can unacceptable
environmental impacts be avoided or mitigated?
1.2 Problem Statement
There is general agreement among interested parties that it is becoming increasingly
difficult to permit new mines. Mining operations typically are complex undertakings that may
be situated in or near complex and sensitive environments. Predicting how a particular mine
may affect the environment during its active life and following closure is no simple task. In EPA
Region 10, new mines present a significant challenge for those who develop CWA Section 402
National Pollutant Discharge Elimination System (NPDES) permits, review public notices and
mitigation plans for CWA Section 404 Dredge and Fill permits, and review or prepare
Environmental Impact Statements (EISs) pursuant to the National Environmental Policy Act
(NEPA). Common pitfalls and problems at mines in Region 10 include water balances that do
lrThis Source Book is intended to address "hardrock" mines but not placer mines or sand and
gravel operations.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
not properly bracket high and low flows, underestimating water treatment needs, using
laboratory detection limits that are too high, using inappropriate modeling approaches, failure to
consider temporary shutdowns and post-closure scenarios, and overall data quality problems
(e.g., non-representative samples). The challenge lies largely in determining with a reasonable
degree of certainty what measures are needed to assure that a technically complex operation,
which is often highly exposed to the variable forces of nature, will remain in compliance with
applicable laws and regulations throughout active mining as well as during and following
closure.
EPA Region 10 encompasses Alaska, Washington, Oregon, and Idaho, states with
environments that range from temperate coastal rainforest to alpine mountain tundra to semi-arid
high plateau to Arctic Ocean. Methods to characterize such diverse environments vary widely,
often depending on how much information is readily available for a particular location. Also,
these environments provide habitat to a range of threatened, endangered, and sensitive species,
including several species of anadromous fish (e.g., salmon, steelhead). As such, the CWA
permitting processes often require consultation pursuant to the Endangered Species Act (ESA)
with the U.S. Fish and Wildlife Service (USFWS) and/or the National Marine Fisheries Service
(NMFS). This can be a time-consuming process. Since much of the mining that occurs in
Region 10 is located on Federal lands administered by the U.S. Forest Service, Bureau of Land
Management, and National Park Service, proper coordination with these Federal land
management agencies, who more often than not have the lead for EIS preparation, is also
necessary to ensure a smooth process. Mining also may occur on State land and Tribal land in
any of the states in Region 10. Regardless of land ownership and mineral or other land use
rights, there are often numerous authorities at these levels that must be integrated into the overall
permitting of any proposed mine. It is hoped that this document will be helpful to these agencies
in understanding EPA's authorities, information, and coordination needs in order to reach permit
decisions in a timely manner.
1.3 General Suggestions for Completing the Permitting Process
Many applicants may feel that CWA permitting and associated NEPA processes are tests
of endurance. This does not have to be the case. In EPA Region 10's experience, many
applicants who encounter delays in acquiring mine permits have either not provided the types of
data and analyses to demonstrate how their proposed operation may affect the environment
during and after operation and/or they have not adequately considered feasible options that may
be more "environmentally friendly." A common problem is that applicants do not collect data
that satisfy the environmental permitting process. For example, metal constituents in surface
water samples may be measured using methods with detection limits that are higher than water
quality criteria values. Other examples would be when geochemical or hydrological and
hydrogeological studies are conducted only to satisfy objectives associated with mine
development and not to help evaluate potential environmental impacts as well.
Applicants can help to minimize delays during NEPA and CWA permit application
processes by considering the following general suggestions:
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Evaluate possible environmental data requirements and initiate environmental
planning on the front end.
• Collect data to meet specific environmental objectives or requirements, and collect
them at the required levels of detail and precision.
• Provide adequate data and analyses for all proposed alternatives.
Be flexible when choosing facility designs, locations, and technologies.
Propose use of treatment, disposal, and reclamation technologies with demonstrated
records of success.
• Use appropriately conservative and justifiable assumptions and interpretations.
• Be pro-active in resolving potential environmental problems.
Establish open lines of communication with the federal and state regulatory and land
management agencies that will oversee the processing of the permit application(s)
very early in the process, not after data are collected and planning is near completion.
Maintain these lines of communication throughout the review and permitting process,
and then throughout the life of the mine as well as through the closure phase.
Review data collection plans and data quality objectives with the appropriate
regulatory agency prior to gathering the data.
Because the CWA permitting and NEPA review processes typically require an applicant to
provide a variety of data at different levels of detail and precision, applicants are likely to realize
cost savings by evaluating their potential data needs from the outset of a proposed project. This
will enable a complete and coherent set of data to be collected efficiently and at the required
levels of precision, while avoiding data gaps or overlap. In order to specifically evaluate
potential impacts to surface and ground water resources, applicants may need to study an area
larger than that required for the mining operation; a common approach is to use a watershed
perspective.
Applicants are encouraged to evaluate different mine layouts, facility designs, and
technologies in an effort to minimize the potential for environmental impact during and
following operation. If newly developed or unproven treatment or disposal technologies are
proposed to be used, applicants can expect to be asked to provide the results of bench- or pilot-
scale tests conducted to evaluate the effectiveness of the technology and to institute more
detailed monitoring to demonstrate their effectiveness.
Finally, applicants will find that impact analyses often require assumptions of future
conditions, waste behavior, and land uses. This is especially true for interpretations,
extrapolations, and modeling of geochemical test results and site hydrology evaluations (e.g.,
water balances). In all cases, applicants should aim to be conservative in their judgment of
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
future conditions and waste behavior and be able to justify their assumptions and interpretations.
As with data collection, applicants are strongly encouraged to discuss sampling and data analysis
plans, including assumptions and uncertainties, with the appropriate regulators prior to
performing the analyses.
1.4 Organization of this Source Book
The remainder of the main text of the source book describes the major environmental
programs that apply to hardrock mining, and the types of information that EPA needs in order to
issue permits, conduct reviews, and otherwise fulfill its legal obligations. Sections 2.0 and 3.0
describe Clean Water Act programs: section 2.0 provides an overview of NPDES permitting,
including many of the major components of the NPDES program, and section 3.0 describes the
§404 program, under which dredge and fill activities are permitted. Section 4.0 covers the
National Environmental Policy Act, which requires an analysis of the environmental impacts of
proposed Federal actions, including the issuance of permits. Section 5.0 covers the requirements
of the Clean Air Act and the Endangered Species Act. Finally, section 6.0 summarizes the types
of effects that mining can have, and the types of analyses and information that EPA expects from
project proponents in applications for permits and in documents and other materials that have to
be reviewed and/or approved by EPA.
The Source Book includes nine technical appendices that describe the major issues that
must be understood and addressed in order to understand and control the impacts from mining
operations. Technical appendices include the following:
Appendix A: Hydrology
Appendix B: Receiving Waters
• Appendix C: Characterization of Ore, Waste Rock, and Tailings
• Appendix D: Effluent Quality
• Appendix E: Wastewater Management
• Appendix F: Solid Waste Management
Appendix G: Aquatic Resources
Appendix H Erosion and Sedimentation
Appendix I Wetlands
2.0 INTRODUCTION TO NPDES PERMITTING (CWA SECTION 402)
The objective of the Clean Water Act is to "restore and maintain the chemical, physical,
and biological integrity of the Nation's waters" (§101(a)). This is to be accomplished through
the control of both point and nonpoint sources of pollution (§101(a)(7)). A number of
interrelated provisions of the Act establish the structure by which the goals of the Act are to be
achieved. Within this overall structure, a variety of Federal and State programs are implemented
to meet the Act's requirements. Under Section 402 of the Clean Water Act, all point source
discharges (see Section 2.1 for definitions) of pollutants to navigable waters of the United States
must be permitted under the National Pollutant Discharge Elimination System (NPDES).
NPDES permits are issued by EPA or authorized states. In Region 10, Oregon and Washington
are currently authorized to implement the NPDES program, and these states issue NPDES
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
permits that are subject to EPA review. EPA is responsible for issuing NPDES permits in Idaho
and Alaska.
Figure 1 shows the NPDES permitting process. The process is summarized in the
following text. The time required to complete each step in Figure 1 varies widely and depends
on a number of factors, notably the timeliness and completeness of information provided by the
applicant. Readers are referred to the U.S. EPA NPDES Permit Writers' Manual (EPA 1996) for
more information. The primary regulations developed by EPA to implement and administer the
NPDES Program are found in 40 CFR Part 122.
The NPDES application process formally begins upon submission of the application to
EPA Region 10 and proceeds through a number of steps required by 40 CFR 122. Prospective
applicants are encouraged to correspond with and, if appropriate, meet with Region 10 staff prior
to preparing and submitting the application. Application requirements are prescribed in 40 CFR
122.21, but it is always beneficial if an open dialogue is established early to ensure that
information needs are fully met, particularly information that supports both the NPDES program
and NEPA. This is especially true for large complex operations, proposed operations in sensitive
environments or on water quality-limited waters, or where there may be special concerns by EPA
or other agencies.
In general, applicants must submit an application at least 180 days prior to discharge or
permit expiration, or if a new source, prior to construction (see Section 2.1 for definition of a
new source). Section 2.5 provides a summary of the information EPA typically expects to be
submitted with the application. Upon receipt of an NPDES permit application, EPA conducts an
initial review for completeness. In the past, EPA has found that initial applications found to be
significantly incomplete inevitably result in delays in the permitting process.
Upon finding that an NPDES permit application is complete, EPA begins determining draft
permit limits and conditions. The following summarizes the major components included in
NPDES permits.
Identification and authorization of the discharge.
Effluent limitations. Effluent limitations are restrictions on the quantity, rates, and/or
concentrations of pollutants that are discharged from point sources. Effluent limits are
either technology-based (based on technology-based effluent limitation guidelines) or
water quality-based (based on water quality standards). In determining the need for
effluent limits, EPA assesses the applicable technology-based limits and the potential
for exceedances of water quality standards. Because data supplied by the permittee is
critical in developing effluent limitations and most of the permit writer's time is spent
in developing effluent limitations, the processes for developing effluent limitations are
described in Sections 2.3 (technology-based limits) and 2.4 (water quality-based
permitting).
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Figure 1. NPDES Permitting Process
Receive Application
Review Application for completeness and accuracy.
Request additional information as necessary.
Using application information and other data sources,
develop technology-based effluent limitations
Using application information and other data sources,
develop quality-based effluent limitations
Develop monitoring requirements for each pollutant
Develop special and standard conditions
Prepare draft permit and fact sheet that explains
permit conditions
Issue public notice for the draft permit and fact sheet
Respond to comments on the draft permit
and issue the final permit
Implement Permit Requirements
Compare water quality-based
effluent limits and technology-based
effluent limits for each pollutant.
Choose more stringent of the two.
ant
is *-
leet
X
^^
t ' '
Consider other applicable
regulations [e.g. ESA, § 401
certification, CZMA]
Source: U.S. EPA NPDES Permit Writers Manual
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
• Monitoring and reporting requirements. Permittees are required to monitor waste
streams and receiving waters to allow EPA (and/or states) to monitor changes in water
quality, to evaluate wastewater treatment efficiency, and determine compliance with
permit limits.
• Special Conditions. Conditions are developed to supplement effluent limitations.
Examples include best management practices (BMPs), additional monitoring
activities, ambient stream surveys, etc.
Standard Conditions. Pre-established conditions are included in all NPDES permits.
These conditions delineate the legal, administrative, and procedural requirements of
the NPDES permit.
To accompany each draft permit, EPA prepares a fact sheet that provides facility
background information, describes anticipated discharge composition and flow, describes
receiving waters, and provides the basis for the proposed effluent limitation(s), monitoring
requirements, and other permit conditions. The fact sheet also documents that the permit
complies with other applicable statutes (e.g., the Endangered Species Act and Coastal Zone
Management Act).
Draft permits are subject to a public comment period of at least 30 days. If requested by
interested parties, EPA may hold a public hearing. At the end of the public comment period,
EPA prepares a final permit along with supplementary documentation that responds to public
comments. The final permit then includes an effective date after which the permittee must
comply with all permit requirements. NPDES permits, whether issued by EPA or an authorized
state, have a clear expiration date, which may be up to five years after issuance. Prior to the
expiration date, permittees need to apply for new permits.
Before EPA can issue a permit in Idaho or Alaska, the state must certify that the discharge
authorized in the permit will comply with state water quality standards (this is known as a 401
certification after the CWA section that requires it). Section 2.3 discusses state water quality
standards provisions important to permitting.
EPA is not obligated to issue an NPDES permit to any mine operator. EPA may reject a
permit application if the agency believes that discharges would not comply with Clean Water
Act provisions and/or anticipated permit conditions. For example, EPA would not issue a permit
to facility where proposed discharges are not expected to meet technology- or water quality-
based effluent limitations (see 40 CFR 122.4 Prohibitions).
The following sections describe key aspects of the NPDES permitting process for mining
discharges. Section 2.1 describes when an NPDES permit is needed. Section 2.2 discusses the
technology-based effluent limitation guidelines which are national standards that apply to
effluent discharges from hardrock mines. Section 2.3 summarizes key aspects of water quality
standards related to NPDES permitting and describes how water-quality based effluent limits are
developed. Section 2.4 describes storm water permitting and Section 2.5 provides an overview
of the information that EPA needs in order to issue an NPDES permit.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Because of the complexities and site-specific factors associated with projecting NPDES
permit requirements, EPA strongly recommends that mine operators coordinate with EPA and
states early in the planning process. This will assist in evaluating options for wastewater
management practices and identifying NPDES information needs.
2.1 When is an NPDES Permit Needed?
As noted in Section 2.0, NPDES permits are required for any discharge of pollutant from a
point source to waters of the U.S. The term "point source" is defined very broadly under the
Clean Water Act, in part because it has been refined through over 25 years of litigation. It means
any discernible, confined and discrete conveyance, such as a pipe, ditch, channel, tunnel,
conduit, discrete fissure, or container (see 40 CFR 122.2). Similarly, the term "water of the
U.S." is defined very broadly under the Clean Water Act and through years of litigation. It
means navigable waters, tributaries to navigable waters, interstate waters, the oceans out to 200
miles, and intrastate waters which are used by interstate travelers for recreation or other
purposes, as a source offish or shellfish sold in interstate commerce, or for industrial purposes
by industries engaged in interstate commerce.
Given these broad definitions, nearly any discharge from a mine could be considered a
point source. In general, three discrete categories of discharges from mining operations require
NPDES permits: process wastewater, mine drainage, and storm water. Definitions of each are
provided in Table 1. Notably, tailings may not be discharged into water of the U.S., including
marine waters. NPDES permit applicants are encouraged to communicate with EPA or an
authorized state to determine how to categorize discharges and to discuss the permitting process.
For new dischargers, EPA's NPDES regulations [40 CFR § 122.21(a)] require prospective
dischargers (in States without an approved NPDES program) to submit, prior to beginning onsite
construction, information to the EPA Region that will allow a determination by EPA of whether
the facility is a "new source". "New source" is defined as any building, structure, facility, or
installation from which there is or may be a discharge of pollutants, the construction of which
commenced after promulgation of applicable new source performance standards (see Section 2.2
for discussion of new source performance standards). Specific criteria that EPA uses to
determine whether or not a discharge is a new source are in 40 CFR § 122.29. In general, most
new mining operations are defined as new sources. Construction at existing facilities may
represent a new source depending upon the age of the facility.
If the facility is determined to be a new source, 40 CFR 122.29(c) provides that the
issuance of the NPDES permit is subject to the environmental review requirements of NEPA,
and thus to EPA's NEPA regulations at 40 CFR Part 6 Subpart F. In cases where NEPA applies,
EPA expects the permit applicant to begin the environmental review process by preparing an
Environmental Information Document (EID) with the NPDES permit application (see Section
4.0). In preparing a draft new source NPDES permit, the administrative record on which the
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Table 1. Categories of Discharges from Mines
Process wastewater
"...any water which, during manufacturing or processing, comes into direct
contact with or results from the production or use of any raw material,
intermediate product, finished product, byproduct, or waste product." (40
CFR 122.22)
See Section 2.3 for discussion of effluent limitation guidelines applicable to
process wastewaters.
Mine drainage
"...any water drained, pumped, or siphoned from a mine." (40 CFR
440.132) [See Table 3 for definition of "mine."]
See Section 2.3 for discussion of effluent limitation guidelines applicable to
mine drainage.
Storm water (associated
with industrial activity)
"... the discharge from any conveyance which is used for collecting and
conveying storm water and which is directly related to manufacturing,
processing or raw materials storage areas at an industrial plant. ...[T]he
term includes, but is not limited to, storm water discharges from industrial
plant yards; immediate access roads and rail lines used or traveled by
carriers of raw materials, manufactured products, waste material, or
byproducts used or created by the facility; material handling sites; refuse
sites; sites used for the application or disposal of process waste waters (as
defined at 40 CFR part 401); sites used for the storage and maintenance
of material handling equipment; sites used 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; and areas where industrial activity has taken place in the
past and significant materials remain and are exposed to storm water....
For the purposes of this paragraph, material handling activities include the
storage, loading and unloading, transportation, or conveyance of any raw
material, intermediate product, finished product, byproduct or waste
product. The term excludes areas located on plant lands separate from the
plant's industrial activities, such as office buildings and accompanying
parking lots as long as the drainage from the excluded areas is not mixed
with storm water drained from the above described areas." (40 CFR
122.26(b)(14). Note that a permit is NOT required for "...discharges of
storm water runoff from mining operations ... which are not contaminated
by contact with or that has not come into contact with, any overburden, raw
material, intermediate products, finished product, byproduct or waste
products located on the site of such operations." (40 CFR 126(a)(2))
See Section 2.4 for a discussion of storm water permitting.
draft permit is based must include the EID prepared by the applicant, the environmental
assessment (and, if applicable, the FNSI) prepared by EPA, and/or the environmental impact
statement (EIS) or supplement, if applicable. In addition, public notice for a draft new source
NPDES permit for which an EIS must be prepared cannot take place until the draft EIS is issued
[40 CFR Part 124.10(b)]. It is also important for applicants to recognize that 40 CFR 122.4(1)
prohibits issuance of a NPDES permit to a new source or a new discharger if the discharge from
its construction or operation will cause or contribute to the violation of water quality standards.
Thus EPA places a very strong emphasis on demonstrating within the NEPA process that the
proposed mining operation will be able to comply with applicable water quality standards during
construction, operation and through closure.
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2.2 Technology-based National Effluent Limitation Guidelines
Section 301(b)(2) of the Clean Water Act requires technology-based controls on effluents.
These technology-based controls are established in effluent limitation guidelines (ELGs).
Section 304(b) of the Clean Water Act requires EPA to promulgate regulations providing ELGs
that set forth the degree of effluent reduction attainable through the application of the "best
practicable control technology currently available" (BPT) and the "best available technology
economically achievable" (BAT). For new industrial dischargers (new sources), §§304(c) and
306 require EPA to promulgate "new source performance standards" (NSPS) based on "best
available demonstrated technology." To move toward the Act's goals of eliminating the
discharge of all pollutants, existing industrial discharges were required to achieve these ELGs by
specific dates: BPT ELGs by 1977 and BAT by 1983. All new sources are required to meet
NSPS from their inception.
The current ELGs for the ore mining and dressing industry were promulgated by EPA in
1978 (BPT) and 1982 (BAT and NSPS). The ELGs for the ore mining and dressing industry are
found at 40 CFR Part 440, which applies generally to facilities classified with Standard
Industrial Classification (SIC) code 10; this includes and is limited to the mining and milling of
metalliferous ores (this discussion does not include placer gold mines, for which the ELGs at 40
CFR Part 440 Subpart M were promulgated in 1989 and take a somewhat different form than the
rest of Part 440). Other than gold placer mining, EPA has divided the ore mining and dressing
category into 11 subcategories based on the type of ore mined and milled. The subcategories for
which EPA has established ELGs for one or more types of discharges are shown in Table 2.
For the various subcategories, there are ELGs for two types of discharges: "mine drainage"
and "process" wastewater. The latter generally includes effluent from mills (such as water
contained in tailings) and other concentration (or, in RCRA terms, "beneficiation") operations,
such as dump and heap leach operations. See Table 1 for definitions of mine drainage and
process wastewater. The ELGs specify numeric limitations, and contain various applicability
conditions and exemptions. For certain mills in some subcategories, the NSPS ELGs allow no
discharge except in net precipitation areas, where so-called "zero discharge" facilities may
discharge only the volume of water that represents the excess of annual precipitation over annual
evaporation. Under certain conditions, Part 440 provides a "storm exemption" from applicable
ELGs for discharges from qualifying facilities in all subcategories. Tables 2 and 3 provide an
overview of the requirements of Part 440. Table 2 shows the types of ELGs that have been
promulgated for the various subcategories and the types of limits established for these categories.
Table 3 presents certain definitions (e.g., of "mine") as well as a summary of the storm
exemption.
It is worth noting that ELGs are established for only a limited number of the pollutants that
are likely or known to be present in the discharge from metal mines and mills (for example, the
ELGs establish concentration limits for only one or a few metal pollutants, although a suite of
heavy metals may generally co-occur in discharges). Compliance with the ELGs is intended to
ensure that other metals present in the discharge are adequately treated. The ELGs' technology-
based concentration levels are considered the baseline for discharges.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
A semantic distinction is also worth noting. Although the ELGs establish technology-
based limits, neither the ELGs nor other regulations require the use of any particular technology,
and this fact is often misunderstood. Rather, the ELGs require that discharges achieve at least a
comparable level of treatment as the technology on which the limit is based.
Any applicable limitations and conditions that are specified in the ELGs must be
incorporated into the NPDES permit. Therefore, it is critical that permit applicants adequately
characterize their operations and discharges so that it can be determined which ELGs apply.
Predicting a water balance and maintaining proper water management are critical to ensuring
compliance with the "zero discharge" provisions of certain of the ELGs. Water balance issues
are discussed in more detail in Appendices A and E. As noted throughout this document, early
consultation with EPA is strongly recommended. With the advent of the storm water program
(section 2.4), consultation with EPA to ensure discharges are correctly characterized has become
even more important.
Figure 2 gives an example of the care with which discharges must be examined and
characterized in order to determine their regulatory classification. As can be seen, both the
source of discharge and the ways in which discharges are managed (segregated versus mixed, for
example) affect the regulatory classification and thus the applicable standards and requirements.
For discharges or pollutants not covered by the ELGs, EPA uses Best Professional
Judgement (BPJ) to develop technology-based limits. In addition, when technology-based limits
cannot be defined or will not ensure compliance with applicable water quality standards for the
receiving waters, permit writers develop more stringent water quality-based limits (see section
2.3).
Information on implementation of ELGs in permits can be found in the Permit Writers
Manual. More information on the development of ELGs for the ore mining and dressing
industry is found in The Development Document for Effluent Limitations Guidelines and
Standard for the Ore Mining and Dressing Point Source Category (EPA 440/1-82/061).
2.3 Water Quality Standards and Water Quality-Based Permitting
In addition to the technology-based limits discussed in the previous section, EPA evaluates
proposed discharges to determine compliance with Section 301(b)(l)(C) of the CWA. This
section of the Act requires the establishment of limitations in permits necessary to meet water
quality standards. In deciding whether or not water quality-based effluent limits are needed,
EPA first determines whether the discharge would cause, has the reasonable potential to cause,
or would contribute to an excursion of water quality criteria. If a "reasonable potential" exists,
then
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Table 2. Industry Sectors and Types of Applicable Limits 40 CFR Part 440
Industry sectors covered by subparts
Types of limits placed on discharges
Subpart (Subcategory):
A Iron ore
B Aluminum ore (bauxite)
C Uranium, Radium, and Vanadium ores
D Mercury ore
E
F
G
Titanium ore
Tungsten ore
Nickel ore
H Vanadium ore (when mined alone)
I Antimony ore-reserved
J Copper, Lead, Zinc, Gold, Silver, and
Molybdenum ores (except gold/silver
placer, which is in subpart M)
K Platinum ores
Subparts A, B, C, D, E, F, G, H, J, K: Numeric limits
on mine drainage.
Subparts A, C, E, F, G, H, J, K: Numeric limits on
process waste water discharges from certain mills
Subparts A, C, D, J: Zero discharge allowed from
certain mills except, if precipitation exceeds
evaporation on annual basis. Such facilities may
discharge the difference (net precipitation) and
discharges must meet mine drainage limits.
Subpart J: Zero discharge allowed from certain mills,
except that discharge may be allowed if
contaminant buildup in recycle water interferes with
ore recovery; this requires operator to make such a
demonstration.
Table 3. Selected Definitions and Provisions in 40 CFR Part 440
Selected Definitions
§440.132
"Active mining area"
"a place where work or other activity related to the extraction, removal, or recovery of metal ore is
being conducted, except with respect to surface mines, any area of land on or in which grading has
been completed to return the earth to desired contour and reclamation work has begun."
"Mine"
Active mining area, including "all land...used in or resulting from the work of extracting metal ore or
minerals from their natural deposits by any means or methods,..."
Selected Provisions
§440.131(b)and(c)
Storm exemption for discharge and no discharge facilities in subcategories A,B,C,D,E,F,G-H,J,K:
Facilities designed/constructed/maintained to contain or treat normal process water and 10-year/24-
hour precipitation may qualify for exemption from ELG limits. 10-year/24-hour volume includes runoff
from all active mine areas that is not diverted. Development document provides details on qualifying
for "excursion:"
12 other paragraphs describing meaning of "contain" and "treat" and further explaining the scope of
storm exemption.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Yes
Do discharges from waste rock 01
overburden piles combine with
"mine drainage"?
Total Discharge, including
storm water runoff, subject to
40 CFR 440
Is there a dry weather point
source discharge from the pile?
Individual permit required to
discharge (include BPJ
technology-based limits)
No
Coverage tentatively allowed
under multi-sector general
storm water permit
1. Implement BMPs
2. Initial screen
3. Twice yearly monitoring for metal:
Are pollutants discharged at
levels well below benchmark
threshold values?
Yes
Would the discharge cause or
contribute to a water quality
standards violation?
Individual permit required to
discharge (include water
quality-based limits)
Yes
No
No
Coverage
under an
individual
NPDES permit
Individual permit required
to discharge (include BPJ
technology-based limits)
Yes
Discharges solely composed
of storm water covered by
multi-sector general storm
water permit
Figure 2. Example of Discharge Classification Depending on Wastewater
Source and Management
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
water quality-based effluent limits are calculated for that parameter. The permitted effluent
limit for a particular pollutant will be the more stringent of either the technology-based or water
quality-based limit.
Where there is a "reasonable potential", EPA also develops water quality-based effluent
limits for whole effluent toxicity (WET). WET is defined as the total toxic effect of an effluent
measured directly with a toxicity test. WET is a useful parameter for assessing and protecting
against impacts upon water quality caused by the aggregate effect of a mixture of pollutants in
the effluent. EPA develops water quality-based effluent limits according to the guidance in
Technical Support Document for Water Quality-Based Toxics Control (EPA 1991; also called
the "TSD"). More general information on water quality-based permitting can be found in the
Permit Writers Manual. Information used to determine the need for and to develop water
quality-based effluent limits includes:
• Applicable receiving water quality standards
• Characteristics and variability of the effluent
Characteristics and variability of the receiving water
• Where appropriate, dilution of the effluent in the receiving water (mixing zone)
Because the receiving water quality standards are key to developing water quality-
based effluent limits, a brief discussion of water quality standards and mixing zones is presented
below. Various provisions of water quality standards are also discussed in Appendices B and D.
Water Quality Standards. Under Section 303(c) of the Clean Water Act, States are required to
develop water quality standards to protect public health, enhance the quality of water, and serve
the purposes of the Clean Water Act. EPA's regulations for State development of water quality
standards are at 40 CFR Part 131. All 50 states have developed water quality standards that EPA
has approved.
EPA has found that correctly identifying applicable water quality standards often poses
significant challenges for mine project proponents. Since many projects will include direct or
indirect discharges to surface waters, knowing the applicable standards is essential to
determining whether a project will adversely affect the environment and whether there is a need
for water quality-based effluent limits. Baseline monitoring programs and evaluation of
potential impacts to surface water should be tailored towards being able to determine whether
standards will be met.
Water quality standards consist of three major components:
Designated Uses: All water bodies in a State are classified based on expected
designated uses. Typical designated uses include public water supply, recreation, and
propagation offish and wildlife. Different segments of a water body may have
different uses. This is important because both impact predictions and water quality-
based effluent limits must consider downstream uses.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
• Water Quality Criteria: Section 303 of the Clean Water Act requires states to adopt
criteria sufficient to protect the designated uses for State waters. These criteria may be
numeric or narrative. Numeric water quality criteria are typically expressed as levels,
constituent concentrations, or toxicity units. Narrative criteria are statements that
describe water quality goals, e.g., "free of objectionable color, taste, or odor" or "free
from toxics in toxic amounts." EPA requires States to develop mechanisms to
implement narrative criteria. For water bodies with multiple designated uses, multiple
criteria also apply. The most stringent of the applicable criteria is used to develop
water quality-based effluent limits.
Of note for mining sites is that water quality criteria for some metals are hardness
dependent. Also, some state water quality criteria for metals are presented in different
forms (total, total recoverable, or dissolved). However, NPDES regulations require
that permit limits be expressed as total recoverable. Where the criteria are different,
EPA uses default translators to translate between total and dissolved. EPA uses
default translators unless the permittee develops approvable site-specific translators
(see Appendix B).
Anti-degradation: Each State must adopt an anti-degradation policy. State policies
must incorporate three components. First, existing uses must be maintained and
protected. Second, where water quality is higher than necessary to protect designated
uses, that quality must be maintained and protected unless degradation is shown to be
necessary for social and economic reasons and other alternatives are not available.
Third, waters that are designated as Outstanding Resource Waters may not be
degraded. In states that have approved NPDES permit programs the states will
incorporate compliance with their anti-degradation policy as a part of the permitting
process. For states without an approved NPDES program, where EPA will be issuing
the permit, EPA will require the affected state to determine compliance with the state's
anti-degradation policy and provide EPA with certification of compliance. Applicants
should consult with the appropriate state agency and be prepared to demonstrate that
the proposed project will comply with the state's anti-degradation policy.
Mine operators should initially obtain the applicable State water quality standards and
regulations. These can be obtained directly from State agencies. Most are also now available
from State government websites on the Internet. Each State must review its water quality
standards every three years, although more frequent changes to standards and regulations are
common. Operators must obtain the most recent standards and remain up-to-date on changes
throughout the permitting process. This further emphasizes the need for frequent communication
with State agency personnel to anticipate potential standard modifications that could affect
project planning and evaluation.
Mixing Zones. Mixing zones allow for concentrations of pollutants to exceed water quality
criteria in small areas immediately around discharge points prior to full mixing of effluent and
the receiving waters. Under the Clean Water Act, States have the authority to determine whether
they will allow mixing zones and under what conditions. As such, each State has different
mixing zone provisions. The sizes of mixing zones are often determined based on low flow
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stream conditions, i.e., when the least dilution is available in the receiving water. In addition,
available dilution is dependent on background constituent concentrations. A discharger must
apply to the appropriate state agency for a mixing zone and the state must certify the mixing
zone for EPA to use it in developing permit limitations. A mass balance, modeling, or other
mixing zone assessment is generally required to support a mixing zone application. In addition,
some states may require a biological assessment to support the mixing zone. EPA consults with
states early on in the NEPA process, and NEPA documents generally display effluent criteria
based on various dilution scenarios. EPA also generally sends preliminary draft permits to states
for pre-certification. Mixing zones are discussed in more detail in Appendix B.
Site-specific Criteria andReclassification. States typically have provisions for establishing site-
specific criteria for individual constituents in a specific water body. Such criteria often allow for
higher constituent concentrations than state-wide criteria because the individual water body can
be demonstrated to achieve designated uses at the higher levels. Mine operators who elect to
pursue site-specific criteria will be required to provide extensive chemical and biological testing
for the water body. They need to work closely with State agencies in developing any requests
for site-specific criteria. In addition, EPA needs to be consulted because site-specific criteria
require EPA approval since they represent changes to the State water quality standards.
Modifications to state standards also require public involvement.
If a water body is not being used for a designated use, mine operators can pursue re-
classification. The criteria under which a designated use may be removed are generally defined
at 40 CFR Part 131.10(g). Requests for re-classification are also complex and require close
coordination with State agencies and EPA. In addition, 40 CFR Part 131.10(h) specifies where
designated uses cannot be removed. Specifically, designated uses cannot be removed if they are
existing uses, unless more protective uses are applied.
Total Maximum Daily Load (TMDL). Section 303(d) of the CWA requires States to identify
water bodies that are not meeting their assigned designated uses (e.g., water bodies that exceed
the water quality criteria). Section 303(d) also requires states to develop TMDLs (total
maximum daily loads) for these water quality-limited water bodies. A TMDL is a determination
of the amount of a pollutant, or property of a pollutant, from point, nonpoint, and natural
background sources, including a margin of safety, that may be discharged to a water-limited
water body. The TMDL defines waste load allocations for point sources that discharge to the
water body. These waste load allocations are developed into permit limits. New mine
proponents should ascertain whether surface waters in the project vicinity have been included on
the 303(d) list and, if that is the case, the reasons for not attainting the water body's designated
uses. If there are listed water bodies, coordination with EPA and State agencies is essential to
determine the status of any TMDLs and how the listing could affect NPDES permit
requirements.
2.4 Storm Water
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
In addition to the development of effluent limits and conditions for discharges of
wastewater, the NPDES Program also includes provisions for control of storm water discharges.
As indicated in section 2.1, storm water associated with industrial activity includes any
discharges from conveyances directly related to manufacturing, processing or raw materials
storage areas at industrial facilities. On August 7, 1998, EPA published in the Federal Register
a further clarification of the applicability of the effluent guideline requirements for mine
drainage and the applicability of EPA's storm water regulations to runoff from waste rock and
overburden piles (63 FR 42533-42548). Figure 2 illustrates how discharge from a waste rock
pile may be classified as either wastewater (i.e., mine drainage) or storm water. In summary,
EPA's storm water regulations generally apply to most storm water discharges from active and
inactive mine sites where the storm water discharges are not commingled with process/mill water
or mine drainage.
Storm water associated with industrial activity at mine sites may be permitted in two ways,
either by an individual facility-specific NPDES permit or by a general permit. Facilities may be
required to or may request to be covered under an individual permit. For example, the facility
may wish to consolidate the control of both process water and storm water discharges under a
single comprehensive individual NPDES permit. In other cases, EPA or a delegated state may
require an individual permit to address facility-specific conditions (e.g., the necessity for water
quality-based limits for discharges to streams in certain cases.)
Unlike discharges of process wastewater where numerical effluent limits (technology-
based and/or water quality-based) are used to control the discharge of pollutants, the primary
permit condition used to address discharges of pollutants in a facility's storm water is a site-
specific pollution prevention plan or best management practices (BMP) plan. All individual
permits for storm water discharges issued by EPA will include a requirement to develop a BMP
plan. BMPs are defined in 40 CFR 122.2 as "... schedules of activities, prohibitions of practices,
maintenance procedures, and other management practices to prevent or reduce pollution of
'waters of the United States.' BMPs also include treatment requirements, operating procedures,
and practices to control plant site runoff, spillage or leaks, sludge or waste disposal or drainage
from raw material storage." See Appendix E and H for more information on development of a
BMP Plan. Beyond the BMP plan, permits may include other requirements (such as monitoring)
based on the Best Professional Judgment (BPJ) of the permit writer and as necessary to ensure
compliance with water quality standards.
EPA has determined that certain categories of discharges, including many categories of
storm water discharges, are more appropriately controlled by a "general" permit rather than by
individual permits for each discharge. General permits are issued under the provisions of 40
CFR 122.28 and contain eligibility requirements as well as the specific requirements that
applicants must follow in order to have their discharges authorized under the permit. A mining
facility may elect to have any storm water discharges authorized under an EPA or State NPDES
permitting authority-issued general permit (depending on the mine's location). Mining sites
within EPA's jurisdiction may seek permit coverage under the Multi-Sector General Permit for
Storm Water Discharges Associated with Industrial Activities, following the sector-specific
requirements for Mining Activities. This EPA permit is commonly referred to as the MSGP, and
the most recent version issued by EPA is referred to as the MSGP-2000. The sections of the
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MSGP-2000 applicable to hardrock mining facilities primarily include requirements for a site-
specific Storm Water Pollution Prevention Plan (SWPPP) which incorporates BMPs and
applicable monitoring provisions. As required by the August 7, 1998 Federal Register, storm
water discharges from waste rock and overburden must be more extensively tested prior to
submitting an application as well as during the permit term (i.e., during years two and four of
the five-year permit coverage). This includes sampling and analysis for metals.
EPA's MSGP includes three types of monitoring: analytical or chemical monitoring,
compliance monitoring for effluent guidelines compliance, and visual examinations for storm
water discharges. The analytical monitoring requirements contained in the MSGP include
"benchmarks," that is, pollutant concentrations which EPA has determined represent a level of
concern. The level of concern is a concentration at which a storm water discharge could
potentially impair, or contribute to impairing water quality or affect human health from ingestion
of water or fish. The benchmarks are also viewed by EPA as a level that, if below, a facility
presents little potential for water quality concern. As such, the benchmarks also provide an
appropriate level to determine whether a facility's storm water pollution prevention measures are
being successfully implemented. The benchmarks are not effluent limitations and should not be
interpreted or adopted as such. These values are merely levels which EPA has used to determine
if a storm water discharge from any given facility merits further monitoring to ensure that the
facility has been successful in implementing a SWPPP. For more detail on the monitoring
requirements for hardrock mining facilities, refer to Part 6.G of the MSGP-2000, and the EPA
discussion of the monitoring requirements for industrial storm water discharges published in the
Federal Register (65 FR 64766 - 64773, October 30, 2000).
In areas where EPA is the permitting authority (e.g., Idaho and Alaska), the MSGP
authorizes storm water discharges from the actual ore processing operation at the mine site. In
contrast, any clearing, grading and excavation activities conducted as part of the exploration and
construction phase of a mining operation must be permitted under the most recent issuance of the
EPA Construction General Permit if the area disturbed is one or more acres, because discharges
from such areas are best managed under the construction-related BMPs and requirements
contained in the Construction General Permit. Exploration/construction operations of less than
one acre can be covered by the Multi-Sector General Permit. See Part 6.G.5 of the MSGP and
the most current EPA-issued Construction General Permit for further details.
Most general permits contain eligibility restrictions—that is, the permit prohibits certain
discharges from coverage (see Part 1.2 of the EPA-issued MSGP-2000 for further details).
EPA (and authorized states) also have the discretion to deny general permit coverage to any
discharge and require an individual permit. Therefore, the Agency recommends that mine
operators coordinate with EPA or their state NPDES permitting authority prior to submitting an
application or request for permit coverage.
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2.5 Information Needs for NPDES Permitting
In order to issue an NPDES permit, EPA and authorized States need extensive information
about the proposed facility and the anticipated discharges. Application and information
requirements are specified in the following sections of the regulations:
• 40 CFR 122.21(f): Information requirements for all applicants.
40 CFR 122.21(g): Application requirements for all existing dischargers.
• 40 CFR 122.21(h): Application requirements for facilities that discharge only non-
process wastewater.
• 40 CFR 122.21(k): Application requirements for new sources and new discharges.
40 CFR 122.26(c): Application requirements for facilities that discharge storm water
associated with industrial activity.
Table 4 identifies the various forms that these sections require to be submitted and the
types of information required by each. Copies of the forms may be obtained from EPA and
authorized states2.
Table 4. EPA Forms Required for NPDES Application
Form number
EPA 351 0-1 (Forml)
EPA 351 0-2C (Form 2C)
EPA 351 0-2D (Form 2D)
EPA3510-2E(Form2E)
EPA 351 0-2F (Form 2F)
EPA 35 10-6
Applicant
All new permits and renewals
Existing dischargers
New sources and discharges
Discharges of non-process
wastewater
Storm water associated with
industrial activity (individual
permit)
Storm water associated with
industrial activity (general
permit)
Information type
Basic information on the facility, location,
owner, etc.
Detailed information on discharge
sources, locations, volumes, sources,
treatment, characterization.
Similar to Form 2C, but some data may
have to be estimated.
Information on discharge, chemistry,
treatment, etc
Detailed information on storm water
sources and characteristics.
Notice of Intent for discharge(s) to be
covered under multi-sector general permit
(see section 2.4)
2 Forms also are available via the Internet at http://www.epa.gov/owm/npdes.htm or
http://www.epa.gov/owm/swlib.htm.
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Table 5 provides an overview of the types of information generally needed to develop an
NPDES permit. The table references the Source Book appendices where additional details
regarding information needs may be found. The magnitude and extent of the information needs
described in Table 5 may depend on site-specific factors. Permit applicants should consult with
EPA and the certifying State agency early in the planning process to ensure that appropriate data
is collected. This is particularly the case where the permittee applies for a mixing zone, elects to
develop translators or site-specific criteria, or where threatened or endangered species may be
present.
Table 5. Overview of Information Needs for NPDES Permitting
Information Type
Description of wastewater
management and water balance
Effluent characteristics and
variability
Receiving water characteristics
and variability
Storm water characterization
Determination of available
dilution
Site-specific assessments
Data Needs
Outfall locations and topographic
map
Identification of sources of pollutants
and sources of wastewater
Hydrologic characterization, water
balance
Description of wastewater treatment
Flow, chemical, physical and WET
characterization
Flow, chemical, physical, and
biological characterization
Topographic map
Flow, chemical analysis, physical
analysis
Description of BMPs
Mixing zone assessment, modeling
Aquatic resources characterization
Development of translators
Development of site-specific criteria
Source Book Appendix
n/a
Appendix E and F
Appendix A
Appendix E
Appendix D
Appendix B
Appendix D
Appendix E
Appendix B
Appendix G
Appendix B
Appendix B
3.0 DISCHARGE OF DREDGED OR FILL MATERIAL TO WATERS OF THE U.S. (SECTION 404)
Section 404 of the Clean Water Act addresses the placement of dredged or fill material into
waters of the U.S. and has become the principal tool in the preservation of wetland ecosystems.
Wetlands subject to regulation under Section 404 are those areas that meet the criteria defined in
the 1987 Corps of Engineers' Wetland Delineation Manual. Section 404 regulatory authority is
shared between the EPA and the Corps of Engineers (COE or Corps). Section 404(a) establishes
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the authority for the COE to issue permits for discharges of dredged or fill materials into "waters
of the U.S." at specified disposal sites. Permitted disposal sites must comply with EPA's
§404(b)(l) guidelines. In addition, §404(c) gives EPA "veto" authority to prevent or reverse
COE permit issuance at specified disposal sites. In practice, EPA only exercises its veto power
in rare instances where the proposed disposal site is of significant resource value, and where
EPA and the COE cannot resolve disputes through the normal public notice review process.
Section 404(e) establishes that the Corps may issue general permits on a State, regional, or
National basis for categories of activities that the Secretary of the Army deems similar in nature,
cause only minimal adverse environmental effects, and have only a minimal cumulative adverse
effect on the environment. General permits may be issued following public notice and a period
for public comment; the permits must be based on the §404(b)(l) guidelines and establish
conditions that apply to the authorized activity. Exceptions to §404 requirements are established
in §404(f) and conditionally include the construction of temporary roads for moving mining
equipment. Applicants are strongly encouraged to check with the local COE District office
regarding general permits and special conditions that may be in effect in the area in which they
propose to mine. Often there are state-specific conditions imposed, particularly with respect to
Nationwide Permits.
The process of issuing an individual §404 permit begins with a permit application. The
application typically contains information describing the project, project area, and project
purpose; wetlands and other "waters of the U.S." that could potentially be directly or indirectly
impacted; and mitigation, monitoring and maintenance plans. The §404(b)(l) Guidelines
require the proponent to demonstrate that the selected project alternative is the least
environmentally damaging practicable alternative. It is important to note that the preferred
alternative selected during the NEPA analysis may not be the least environmentally damaging
practicable alternative. In addition, it should be noted that an alternative does not necessarily
have to involve only land currently owned or controlled by the proponent. It can involve actions
(mitigation, for example) on land that could be easily obtained by the proponent.
It is thus important to avoid and/or minimize all impacts to wetlands and other waters of
the U.S. to the fullest extent possible. For proposed fill in 'special aquatic sites', which include
wetlands, there is a rebuttable presumption against the need to fill for non-water dependent
activities. A Memorandum of Agreement (MOA) between the COE and EPA, dated February 6,
1990, establishes the policy and procedure in determining the type and level of mitigation
necessary to comply with the §404(b)(l) Guidelines. The MOA sets 'no net loss' of wetland
functions and values as a national goal and defines the types of mitigation, for practical
purposes, as minimization and compensatory. Although compensatory mitigation is often the
focus of project proponents, from a regulatory perspective, avoidance and minimization should
be the focus of any project with the potential to impact wetlands and other waters of the United
States. A project description submitted as part of an environmental impact assessment or permit
application should clearly demonstrate how avoidance and minimization have been addressed.
The COE evaluates the application based on requirements of the CWA, including the
§404(b)(l) guidelines, and based on comments received from public notice reviewers, which
typically includes EPA. Since the issuance of §404 permits are subject to NEPA review, the
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COE then prepares an environmental assessment or, in some cases, an EIS (or contributes to
another agency's EIS as a cooperating agency) and issues a statement of finding. A permit is
then issued or denied based on the finding. EPA may exercise its veto authority (§404(c)) at
anytime during the permit application process, or even prior to a permit application being filed.
It should be noted that the §404(b)(l) guidelines limit issuance of §404 permits for non-water
dependent projects (including mines) to the "least environmentally damaging practicable
alternative." The term "practicable" is defined [40 CFR230.3(q)] as "available and capable of
being done after taking into consideration cost, existing technology and logistics in light of
overall project purposes."
As was recommended above for NPDES permit applications, it is highly advisable for
applicants for §404 permits to consult with the Corps of Engineers and other appropriate
regulatory and resource agencies prior to submission of the application. This facilitates a mutual
understanding of the resource issues of concern and can enable early identification of
alternatives that avoid and/or minimize impacts and allows for early input on mitigation
requirements and design. This early consultation can significantly reduce the time that might
otherwise be necessary. If the proposed project involves siting a tailings impoundment where
there are or may be wetlands or other waters of the U.S., applicants should consult with both the
Corps and EPA regarding procedures for authorization to site a non-jurisdictional waste
treatment system in waters of the U.S. Also, in May 2002 EPA and the Corps promulgated a
final rule [Federal Register: May 9, 2002 (Volume 67, Number 90)] regarding the definition of
fill material that includes certain mining wastes that are not subject to NPDES effluent
guidelines (e.g., waste rock). Applicants are strongly encouraged to consult with the Corps and
EPA regarding the proper regulatory tool (404 permit vs. NPDES permit) for authorizing the
placement of such material in wetlands or other waters of the U.S.
The Corps has released a number of Regulatory Guidance Letters that were most recently
published in the Federal Register on March 22, 1999 (61 FR 13783-13788). These can be
accessed through the COE website at http://www.usace.army.mil, which also includes extensive
information on COE regulatory programs. Appendix I - Wetlands contains information related
to wetlands terminology, characterization, and impact assessment.
Enforcement authority is divided between the Corps and EPA: the Corps provides
enforcement action for operations discharging in violation of an approved permit while EPA has
primary authority over any operation discharging dredged or fill materials without a §404 permit.
4.0 THE NATIONAL ENVIRONMENTAL POLICY ACT
The National Environmental Policy Act (NEPA) of 1969 became law on January 1, 1970
(Pub. L. 91-190, 42 U.S.C. 4321 et seq.). NEPA serves as the basic national charter for
environmental protection. The law requires every federal agency to analyze and describe
potential environmental effects that could arise from any action or legislation proposed by that
agency. NEPA provides for public participation through public notices of intent, the solicitation
of public comment, and as appropriate, public hearings. A key element of public participation is
scoping, at which time the public can identify the key issues of concern.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
The general framework for implementing NEPA requirements is presented in regulations
issued by the Council on Environmental Quality (CEQ) which may be found at 40 CFR Parts
1500-1508. In general, the analysis and identification of the impacts of proposed federal
actions, and alternatives to those actions, are presented in environmental assessments (EAs)
and/or, for "major federal actions significantly affecting the quality of the human environment,"
in Environmental Impact Statements (EISs). Each of these terms is defined in CEQ's regulations
(40 CFR Part 1508). Over the past 25 years, the NEPA framework for environmental review of
proposed Federal actions has been substantially refined, based on further congressional
directives, action by CEQ, and an extensive body of case law.
Each federal agency has developed its own rules for NEPA compliance that are consistent
with the CEQ regulations but address its own specific missions and program activities. EPA's
NEPA regulations can be found at 40 CFR Part 6.
4.1 EPA's NEPA Role
Under NEPA, EPA can serve as a lead agency, cooperating agency, or reviewing agency.
Most EPA decisions and actions are not subject to NEPA, or the decision making process that
leads to proposed EPA actions has been determined to be functionally equivalent to that required
by NEPA. The major exception to this in the case of mining is the issuance by EPA of NPDES
permits subject to new source performance standards (see section 4.2). The decision whether to
issue such a permit is subject to NEPA, and thus the potential environmental impacts of permit
issuance must be analyzed and documented in an EA and/or EIS. Where an EIS is required,
EPA is either the lead or, more commonly, a cooperating agency in preparing the EIS. EPA
recognizes that many other federal, state, and local authorities have jurisdiction over various
components of a mine's location, construction, operation, and closure. Regardless of EPA's role
under NEPA, EPA tries to work collaboratively with other involved agencies.
Lead Agency. In some instances, delineated at 40 CFR 1501.5, more than one agency's action
is subject to NEPA. In such cases, one of the agencies becomes the lead agency (or there are co-
lead agencies). When an EPA action is subject to NEPA, EPA generally serves as the lead
agency for proposed projects that do not involve federal lands but that include actions over
which EPA has jurisdiction by law. For example, EPA would likely be the lead agency under
NEPA for a proposed project on private lands that requires a new source NPDES permit in a
State where EPA is the NPDES permitting authority (see 40 CFR, Part 6, Subpart F). EPA can
also serve as a lead agency when tribal lands and public lands are involved and where EPA's
permitting authority is broader in scope than another agency's. In addition, EPA is responsible
for NEPA review to support proposed legislation that significantly affects environmental quality
as outlined in 40 CFR 6.102(b). As described in 40 CFR 6.604(g), EPA may prepare NEPA
documentation using agency staff, by contracting with a consulting firm, or by using a 'third
party agreement' between the applicant, EPA, and a contracting firm. The 'third party' approach
is most often used for large mine projects where EPA is the lead agency. Under this approach,
the EPA is responsible for directing the contracting firm while the applicant pays the costs. The
responsibilities of lead agencies are outlined in 40 CFR § 1501.5.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Cooperating Agency. Federal agencies that have jurisdiction by law, but that are not lead
agencies, may be cooperating agencies upon request by the lead agency (40 CFR 1501.6). As a
cooperating agency, EPA participates in the scoping process and, upon request of the lead
agency, may assume responsibilities for developing information and preparing portions of NEPA
documents pertaining to the agency's areas of expertise. For example, EPA generally serves as a
cooperating agency whenever a mine that is proposed on National Forest Service or Bureau of
Land Management land requires an EPA NPDES permit. Depending on the types of expertise
available to the Forest Service, EPA may play a significant role in efforts to predict effluent
quality and evaluate potential water quality impacts.
Reviewing Agency. Under Section 309 of the Clean Air Act, EPA is required to review and
comment in writing on all major Federal actions. The Agency reviews and prepares written
comment on every draft EIS prepared by other agencies, and assigns a rating to the
environmental impact of the proposed action and to the adequacy of the draft EIS (see section
4.3). The comments are available to the public, and the ratings and a synopsis of the comments
are published in the Federal Register. When EPA has serious concerns about the impacts of the
proposal or the adequacy of the EIS, the Agency consults with the lead agency. EPA also
reviews final EISs, particularly ones where significant issues were raised in earlier comments.
EPA comments on final EISs, but not its ratings, are made available to the public and a synopsis
of comments is published in the Federal Register.
If EPA's review of a final EIS determines that a proposed action is or remains
"unsatisfactory from the standpoint of public health or welfare or environmental quality," EPA
may refer the matter to the Council on Environmental Quality in accordance with 40 CFR Part
1504.
4.2 EPA Requirements for Environmental Review Under NEPA and the CWA
40 CFR Part 6 outlines EPA's policies and processes for identifying and analyzing the
environmental impacts of EPA-related activities and for preparing and processing EISs. Subpart
A of the Procedures provides an overview of the Agency's purpose and policy, institutional
responsibilities, and general procedures for conducting reviews. Subpart A outlines EPA's basic
hierarchy of NEPA compliance documentation as follows:
• Environmental Information Document (EID): a document prepared by applicants,
grantees, or permittees and submitted to EPA. This document should be sufficient in
scope to enable EPA to prepare an environmental assessment.
• Environmental Assessment (EA): a concise document prepared by EPA, or by a
contractor under EPA's direction, that provides sufficient data and analysis to
determine whether an EIS or finding of no significant impact is warranted.
• Notice of Intent (NOI): announces the Agency's intent to prepare an EIS. The NO I,
which is published in the Federal Register, reflects the Agency's finding that the
proposed action may result in "significant" adverse environmental impacts on the
human environment.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Environmental Impact Statement (EIS): a formal and detailed analysis of
alternatives including the proposed action, undertaken according to CEQ
requirements and EPA procedures. Guidelines that describe the focus and intent of
EISs are provided in 40 CFR 1502.2. EISs must provide rigorous, unbiased analyses
of potential impacts from the proposed action and its alternatives, determine whether
unavoidable adverse environmental impacts would occur, and describe any irreversible
and irretrievable commitments of resources. The treatment of environmental impact,
which generally receives close scrutiny, must consider connected actions, cumulative
actions, and similar actions (40 CFR 1508.25).
Finding of No Significant Impact (FNSI): a concise document that presents EPA's
finding that the action analyzed in an EA (either as proposed or with alterations or
mitigating measures) will not result in significant impacts. The FNSI is made
available for public review, and is typically attached to the EA and included in the
administrative record for the proposed action.
• Record of Decision (ROD): a statement published in the Federal Register that
describes the course of action to be taken by an Agency following the completion of
an EIS. The ROD typically includes a description of those mitigating measures that
will be taken to make the selected alternative environmentally acceptable.
• Monitoring: EPA is responsible for assuring that decisions on any action where a
final EIS is prepared are properly implemented.
Subpart B of EPA's Procedures provides a detailed discussion of the contents of EISs.
This subpart specifies the format and contents of an executive summary, the body of the EIS,
material incorporated by reference and a list of preparers.
Subpart C of the Procedures describes requirements related to coordination and other
environmental review and consultation requirements. NEPA compliance involves addressing a
number of particular issues, including: (1) landmarks, historical, and archaeological sites; (2)
wetlands, floodplains, important farmlands, coastal zones, wild and scenic rivers, fish and
wildlife, and endangered species; and (3) air quality. Formal consultation with other agencies
may be required, particularly in the case of potential impacts to threatened and endangered
species and potential impacts on historic or archaeological resources. Section 5.2 discusses the
Endangered Species Act consultation process.
Subpart D of the Procedures presents requirements related to public and other Federal
agency involvement. NEPA includes a strong emphasis on public involvement in the review
process. Requirements are very specific with regard to public notification, convening of public
meetings and hearings, and filing of key documents prepared as part of the review process.
Subpart F presents environmental review procedures for the New Source NPDES Program.
This Subpart specifies that the requirements summarized above (Subparts A through D) apply
when two basic conditions are met: (1) the proposed permittee is determined to be a new source
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under NPDES permit regulations (see Section 2.1); and (2) the permit would be issued within a
State where EPA is the permitting authority (i.e., that State does not have an approved NPDES
program in accordance with section 402(b) of the CWA. In EPA Region 10, Alaska and Idaho
do not have approved NPDES programs). This Subpart also states that the processing and
review of an applicant's NPDES permit application must proceed concurrently with
environmental review under NEPA. Procedures for the environmental review process are
outlined. Subpart F also provides criteria for determining when EISs must be prepared, as well
as rules relating to the preparation of RODs and monitoring of compliance with provisions
incorporated within the NPDES permit. Additional information that is not relevant to the
New Source process can be found in Subparts E, G, H, I, and J of the Procedures.
Of particular importance to new source NPDES permit applicants is preparing the
Environmental Information Document (EID). It is highly recommended that applicants confer
with EPA regarding the scope of the EID as a well prepared EID will make the ensuing NEPA
process run much more smoothly. In general, an EID should address the following (adapted
from EPA Region 6, EID Handbook, 1995):
An effective description of the project, with an emphasis on project features which
cause environmental changes, and with alternatives to those features.
A concise description of the environmental setting where the project takes place,
with an emphasis on resources which are highly valued, very sensitive to change
and/or certain to be affected by the project.
• Evidence that the project has been designed and located, and will be built and
operated, to reasonably minimize adverse environmental changes and to improve
environmental benefits.
• The applicant's own assessment of environmental impacts or changes.
• Discussion of cumulative environmental effects which would result from interaction
with other activities in the same watershed, same airshed or same economic region.
Documentation that necessary coordination regarding special resources has taken
place with certain Federal and state agencies (e.g., Corps of Engineers, U.S. Fish and
Wildlife Service, State Historic Preservation Officer).
Section 6 of this Source Book provides guidance on information needs related to NEPA
analyses.
4.3 When is an EIS Required?
The determination of whether or not an EIS is required is important as it impacts the nature
and extent of data that needs to be collected and analyses that need to be performed to determine
the environmental impacts of a proposed project (and project alternatives). NEPA requires that
an EIS be prepared for "major" Federal actions "significantly affecting the quality of the human
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
environment." Generally, the determination of the need for an EIS hinges on finding that the
proposed action would result in significant adverse impacts.
EPA's procedures provide general guidelines and specific criteria for making this
determination (40 CFR 6.605). General guidelines are (40 CFR 6.605(a)):
• EPA shall consider both short- and long-term effects, direct and indirect effects, and
beneficial and adverse environmental impacts as defined in 40 CFR § 1508.8.
• If EPA is proposing to issue a number of new source NPDES permits within a limited
time span and in the same general geographic area, EPA must consider preparing a
programmatic EIS. In this case, the broad cumulative impacts of the proposals would
be addressed in an initial comprehensive document, while other EISs or EAs would be
prepared to address issues associated with site-specific proposed actions.
EPA's specific criteria for preparing EISs for proposed new source NPDES permits are
found in 40 CFR 6.605(b):
The new source will induce or accelerate significant changes in industrial,
commercial, agricultural, or residential land use concentrations or distributions, which
have the potential for significant effects. Factors that should influence this
determination include the nature and extent of vacant land subject to increased
development pressure as a result of the new source, increases in population that may
be induced, the nature of land use controls in the area, and changes in the availability
or demand for energy.
The new source will directly, or through induced development, have significant
adverse effects on local air quality, noise levels, floodplains, surface water or ground
water quality or quantity, or fish and wildlife and their habitats.
• Any part of the new source will have significant adverse effect on the habitat of
threatened and endangered species listed either Federally or by the State.
The issuance of the new source permit would result in a significant direct adverse
impact on a property listed or eligible for listing in the National Register of Historic
Places.
• The issuance of the new source permit would result in significant adverse efforts on
parklands, wetlands, wild and scenic rivers, reservoirs or other important water bodies,
navigation projects, or agricultural lands.
The determination of significance can be challenging. CEQ provides some guidance in the
form of a two-step conceptual framework which involves considering the context for a proposed
action and its intensity (40 CFR 1508.27). Context can be considered at several levels, including
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
the region, affected interests, and the locality. Intensity "refers to the severity of the impact."
CEQ lists a number of factors to be considered when judging severity, including:
Effects on public health and safety
• Unique characteristics of the geographic area
• The degree to which effects are likely to be controversial
• The degree to which effects are uncertain or involve unique or uncertain risks
• Cumulative effect of the action
Whether the action would threaten a violation of Federal, State, or local law or
regulation
The nature of the mining industry can make it particularly difficult to assess significance.
Potential impacts are often uncertain, they often are delayed in time from the permitting action,
and they can be quite controversial. In addition, impacts may occur in environments previously
degraded by mining or other activities, or environments where naturally occurring pollutants
contribute to environmental degradation. It is also important to note that impacts may be both
beneficial and adverse. There may be a significant effect even if, on balance, the effect will be
beneficial.
In general, it is essential for applicants to coordinate with EPA early in the planning
process to determine the data needed in order for EPA to prepare an EIS. Section 6 describes the
general information needed for EISs on new mining proposals.
5.0 OTHER AUTHORITIES
5.1 Clean Air Act
Clean Air Act (CAA) provisions apply to a wide range of emissions sources from mine
sites, including stack/point sources and fugitive sources. Fugitive emissions are generally
defined as sources that are not easily controlled (e.g., conveyors can be controlled while open
piles cannot). CAA requirements are generally applied through several different types of
programs. These requirements can be described by three categories: (1) new source permits,
including prevention of significant deterioration (PSD) and non-attainment permits, (2) new
source performance standards (NSPSs), and (3) State Implementation Plan (SIPs) requirements
for non-attainment areas. Title V of the 1990 CAA Amendments provides for consolidation of
different CAA requirements into single facility permits. EPA's permitting authority is generally
limited to "major" sources. States generally have exclusive permitting authority under CAA
Section 110A(2)c for minor sources. Beyond permitting, EPA must evaluate compliance with
applicable air quality requirements for all new or modified sources associated with proposed
actions that are subject to NEPA.
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Where an operator proposes a new point source or modifications to an existing point
source, the entire facility must be reviewed for air quality impacts. Separate requirements apply
to major and minor sources. Major source determinations are based on the emissions of six
parameters from point sources, including: NOX, SO2, CO, VOCs, particulates, and lead. Most
facilities are major sources if they emit more than 250 tons per year of any of these pollutants.
Comparison of source emissions with these threshold values includes expected reductions to be
provided by proposed control measures. Mines with complex oxidation processes or smelters
generally trigger at least one of the threshold values for the six parameters and are typically
sources subject to the PSD program.
There are two categories of new source reviews/permits: PSD analyses/permits for
facilities in attainment areas, and non-attainment analyses/permits for facilities located in non-
attainment areas. Non-attainment is measured through compliance with the National Ambient
Air Quality Standards (NAAQS) for the six pollutants. A facility in a non-attainment area may
undergo a combination of both PSD and non-attainment analyses: PSD for pollutants that are
achieving ambient air quality standards and non-attainment analyses for specific pollutants that
are causing the non-attainment designation.
PSD requirements include the use of Best Available Control Technology (BACT) for all
emissions sources, stack/point source emissions and fugitives. In addition, total emissions from
a site must not cause exceedances of NAAQS. EPA ensures compliance with NAAQS through
pollutant "increments." The applicable increments for a site depend on facility location. There
are nationwide increments for "Class I" and "Class II" areas. Class I areas lie within 50
kilometers of federally protected lands such as National Parks. More stringent increments may
be established on an airshed-specific basis depending on background air quality and number and
types of sources. In general, facilities that only affect Class II areas do not present issues related
to BACT not meeting the increments. However, facilities located within or that can affect Class
I areas often present difficulties, because the national Class I increments are very stringent and
individual areas can establish even more stringent air quality related values (AQRVs). Modeling
is used under PSD to determine compliance with Class I and II increments.
5.1.1 New Source Performance Standards
As noted above, the PSD and minor source programs address facility-wide air emissions.
Under CAA Sections 111/112, EPA has also established minimum national new source
performance standards (NSPSs) for emissions of certain pollutants discharged from specific
types of industrial units and operations. This includes metallic mineral processing (40 CFR Part
60 Subpart LL) and non-metallic mineral processing (40 CFR Part 60 Subpart 670). Mineral
processing is generally defined as extraction and beneficiation operations associated with
transport and beneficiation of ore, including conveyor belt transfer points, screens, crushers,
storage bins, thermal dryers, and truck and railroad loading and unloading. Underground
operations are excluded. The NSPSs include opacity and particulate matter limits from each
point source. In addition, there is an opacity standard for particulate matter that escapes from
containment systems.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
5.1.2 Specific Sources
Table 6 summarizes the applicability of specific Clean Air Act programs to individual
sources at mining operations, generally in the context of whether emissions are fugitive or stack
emissions, and mobile or stationary sources.
Table 6. Potential Emission Sources at Mine Sites
Source
Overburden, Waste
Rock, Tailings, and
Spent Ore
Land Application
Waste Materials
Re-use
Chemical Storage
Ore Handling and
Piles
Heap and Dump
Leaches
Process Ponds
Mine Pit
Underground
Workings
Blasting
Vehicle Use
Construction
Applicability/A uthorities
Fugitive and mobile sources (vehicles); except for Hazardous Air Pollutants
(HAPs), EPA has limited authority to control fugitives unless there is a major
point source; for major new sources, can require BACT, LAERs, and other
controls needed to comply with PSD/non-attainment requirements; emissions
from uranium mill tailings, asbestos mine wastes, and phosphate rock
(radionuclides) specifically covered by National Emission Standards for
Hazardous Air Pollutants (NESHAPs).
Wet process, little or no CAA applicability
Primary CAA applicability is NES HAP) requirements for asbestos and
radionuclides emissions related to re-use of waste materials containing
asbestos; phosphate rock containing radionuclides; etc.
For wet storage, little or no CAA applicability; for dry, considered fugitives as
discussed under waste rock, tailings, and spent ore above
Open piles - fugitives; Covered storage piles/areas and conveyors - point
sources; conveyor transfer points, covered storage areas, truck and railroad
unloading areas covered by NSPS (opacity and particulates)
Mostly wet and not relevant; where dry, fugitives
Wet - little or no applicability
Major source of fugitive and vehicle emissions, new technology-based
standards for off-road vehicles to be established under Title II; two current
interpretations for vehicles - (1) national - subject to stationary source
permitting as point source, EPA authority largely dependant on major/minor
determination, and (2) Region X - mobile source, exempted from permitting,
but considered by EPA under NEPA.
EPA policy decision that all vents from underground mines are stationary
sources and must be evaluated under NEPA and CAA; permitted as point
sources; uncertain how widely applied
Above ground - fugitives, underground - see underground workings
See mine pits above, haul roads also major sources of fugitives
Exempted from permitting as temporary activity; SIPs typically have generally
applicable requirements (e.q., must not cause nuisance)
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Table 6. Potential Emission Sources at Mine Sites
Source
Reclamation/Post-
reclamation
Inactive/Abandoned
Mines
Generators
Applicability/A uthorities
Theoretically should be covered under new source permitting, major/minor
source issue effects authority; could also be addressed as part of permit
modification; may not be being considered
Except under CERCLA, ongoing activity should be same regulatory and
permitting requirements as active operations; CERCLA actions exempted
from permitting but still must meet standards (PSD, NSPS, etc.)
Point sources, may bring some entire mine sites into major source
requirements; also lower major source threshold for PSD/non-attainment
analysis may arise if greater than about 75 Mw
Note: Some fugitive sources (overburden, land application, etc.) are generally only evaluated when
making a major source determination.
5.2 Endangered Species Act
The Endangered Species Act of 1973 (ESA) requires Federal agencies to "insure that any
action authorized, funded, or carried out by such agency is not likely to jeopardize the continued
existence of any listed species or result in the destruction or adverse modification of critical
habitat of such species." The purpose of the Act is "to provide a means whereby the ecosystems
upon which endangered species and threatened species depend may be conserved" and "to
provide a program for the conservation of such endangered species and threatened species . . ."
Section 7 of the Act, as amended, outlines procedures for interagency cooperation to
conserve Federally listed species and designated critical habitats. Section 7(a)(l) requires
Federal agencies to use their authorities to further the conservation of listed species. Section
7(a)(2) requires Federal agencies to consult with the U.S. Fish and Wildlife Service (FWS)
and/or National Marine Fisheries Service (NMFS; hereafter referred to together as the Services)
to ensure that they are not undertaking, funding, permitting, or authorizing actions likely to
jeopardize the continued existence of listed species or adversely modify designated critical
habitat. For example, EPA will consult with the Services in the issuance of NPDES permits as
well as preparation of NEPA documentation.
The roles and responsibilities of the Services in implementing the Act were described by
the Department of the Interior and the Department of Commerce in a 1974 Memorandum of
Understanding. NMFS is responsible for listed species that occur in marine environments,
including anadromous fish species such as salmon and steelhead that migrate from freshwater to
marine environments during a portion of their life cycle. The FWS is responsible for listed
species that are inland or nonmarine species. If listed salmon and trout species (e.g., bull trout)
occur within a project study area, both Services would be responsible for completing Section 7
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
procedures. The Services also have joint jurisdiction over some listed species (FWS and NMFS,
1998).
The Section 7 consultation process is designed to assist Federal agencies in complying
with the Act. Figures 3 A and 3B describe typical steps in the consultation process. Most
consultation is undertaken informally. First, a general description of the proposed action and a
formal request for a list of proposed, candidate and listed endangered and threatened species
potentially affected by the proposed action are submitted to the Services by the lead Federal
agency. The Services respond with a list of proposed, candidate, and listed species and/or
habitat that occur within the project study area. Although the inclusion of candidate species is
not required by law, the Services consider candidates when making natural resource decisions.
If no species or habitat are present, consultation ends. If species and/or habitat are present and a
project involves major construction activity, a Biological Assessment (BA) must be prepared by
the Federal Agency. The BA identifies the project, summarizes the biology of the listed species,
analyzes the impacts of the proposed action, and determines if there is likely to be an effect
(either beneficial or adverse) on any listed species. The BA is then filed with the Services. If
species and/or habitat are present and the project involves actions other than "major construction
activity," the Federal agency must still evaluate the potential for adverse effects and consult with
the Services. This may consist of preparing a Biological Evaluation (BE) or other type of report
to evaluate these effects.
If the BA or BE concludes that the proposed agency action "is likely to adversely affect"
any of the T&E species, formal consultation with the Services is required.
Formal consultation involves a more detailed review of the proposed action by the
Services. The formal consultation process determines whether a proposed agency action(s) is
likely to jeopardize the continued existence of a listed species or destroy or adversely modify
critical habitat. It also determines the amount or extent of anticipated incidental take of a listed
species. After collecting the best available scientific and commercial information on the listed
species, and reviewing the Federal Agency's BA or BE, the Services prepare a Biological
Opinion (BO) that analyzes the impacts of the proposed action on the listed species. Three
possible conclusions are made in the BO: the proposed action (1) may promote the continued
existence of the species; (2) is not likely to jeopardize the continued existence of the species; or
(3) is likely to jeopardize the continued existence of the species. When the Services make a
determination that the proposed action is likely to jeopardize the continued existence of the
species, reasonable and prudent alternatives must be included in the BO. Reasonable and
prudent alternatives are alternative actions that can be implemented in a manner consistent with
the scope of the Federal agency's action, that are economically and technologically feasible, and
that the Services believe would avoid jeopardy or adverse modification to the listed species, or
critical habitat, respectively. The BO may also include reasonable and prudent measures to
minimize impacts (i.e., amount or extent, or incidental take).
Concurrent with planning for permitting and NEPA review, it is essential that proposed
mine operators work with the lead agency and the Services to plan for ESA compliance.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Biological surveys need to fully address the presence of proposed, candidate, threatened, and
endangered species and/or their habitat. Potential impacts need to be considered in preparing
plans of operations and permit applications. The lead agency will be responsible for ensuring
that final plans of operations/permitted activities are consistent with the findings of the
Biological Opinion. Specific reasonable and prudent measures and alternatives as well as
monitoring requirements identified in the Biological Opinion may be incorporated directly into
NPDES or other permits and Records of Decision issued by EPA.
Non-Federal representatives (e.g., proposed mine operators) may participate in the
informal consultation process, including preparing draft B As. The lead agency must designate
such representatives in writing to the Services. Regardless, ultimate responsibility for
compliance with Section 7 requirements remains with the lead agency (e.g., assuring that draft
BAs are technically sound). More information about the Act and consultation process is found
in the Endangered Species Consultation Handbook published by the Services in March 1998.
This document is available from the USFWS website^
5.3 Resource Conservation and Recovery Act (RCRA)
Under the provisions of RCRA §3001(b)(l), solid waste from the extraction,
beneficiation, and processing of ores and minerals is exempt from regulation as hazardous waste
under RCRA Subtitle C. This section was added to RCRA in 1980 and is known as the "Mining
Waste Exclusion" or the "Bevill Amendment"- several other categories of wastes were also
excluded, and collectively these wastes are known as "special wastes." This provision
precluded EPA from regulating these wastes until the Agency had performed a study and
submitted a Report to Congress, as directed by §8002(f) and (p), and determined either to
promulgate regulations under Subtitle C (that is, to regulate the wastes as hazardous wastes) or
that such regulations were unwarranted (that is, to continue the Exclusion of the wastes from
such regulation). EPA subsequently modified its final hazardous waste regulations to reflect this
new
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Federal
Action
>
t
Action agency requests or
prepares species list
Service prepares list or
concurs with list prepared
by action agency
<-YES-
,30 Calendar Days
Major
Construction
Activity?
-NO->
Service prepares list or
concurs with list
prepared by action
agency
Species/Critical
Habitat Present?
• NO ^
End
Consultation
NO
YES
Biological
Assessment [180
days for action
agency to complete]
Species/Critical
Habitat Present?
Optional
YES
May affect species or critical
habitat?
OR—-
30 Days for Service to respond to
agency Biological Assessment finding
YES
YES
Optional discussions
between parties resulting
in "no effect"
determination
,NO
Likely to adversely affect species
or critical habitat?
YES-
YES
•NO—>
Written
Service
Concurrence
/
^
y>
End Informal
Consultation
Figure 3A. Informal Consultation Under the Endangered Species Act
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Action Agency determines
proposed action may affect
listed species or
designated critical habitats
Action Agency
requests initiation
of formal
consultation
\f
Within 30 days
notify Agency of
missing 50 CFR
402.14(c) data
Information
is complete
— YES-
Consultation
clock starts from
date of receipt
Data is
received and
complete
90 Days
Service formulates Biological
Opinion and incidental take
statement in conjunction with
Agency/Applicant
45 Days
I
90 Days
Review of draft biological
opinion by Action Agency and/or
applicant, if any
Delivery of final biological opinion and
incidental take statement to Action Agency
end formal consultation
Figure 3B. Formal Consultation Under the Endangered Species Act
(USFWS and NMFS, Endangered Species Consultation Handbook, 1998)
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
exemption, and issued a preliminary interpretation of the scope of the exemption. Over the next
decade, there followed litigation, Reports to Congress, and rulemakings. These are not described
in detail here, but rather only the key decisions are highlighted.
In 1985, EPA submitted the first Report to Congress, which addressed wastes from
mineral extraction and beneficiation. On July 3, 1986 (51 FR 24496), EPA published the
regulatory determination for these wastes, which stated that regulation of these wastes as
hazardous wastes was unwarranted.
In the late 1980s, EPA proposed and promulgated a series of rules that redefined the
boundaries of the Exclusion for mineral processing wastes. These rulemaking notices provided
explicit criteria for making key distinctions between mineral beneficiation and processing and
for determining whether specific mineral processing wastes met certain other criteria and were
thus eligible for the Exclusion. The full rulemaking process was completed with the
promulgation of final rules on September 1, 1989 (54 FR 36592) and January 23, 1990 (54 FR
2322).
Of all mineral processing wastes, only 20 were found to meet the newly promulgated
special waste criteria; all other mineral processing wastes were removed from the Mining Waste
Exclusion. On July 30, 1990, EPA submitted a Report to Congress on these 20 wastes.
Subseqently, EPA made a regulatory determination that regulation of these wastes as hazardous
wastes was unwarranted.
As a result of the rulemaking process, all but 20 mineral processing wastes lost their
special waste status, and assumed the same regulatory status as any other industrial solid waste.
Therefore, if they exhibit one or more characteristics of hazardous waste, or are listed as
hazardous waste, they must be managed in accordance with RCRA Subtitle C or equivalent State
standards.
EPA considers these wastes to be "newly identified" since they were brought into the
RCRA Subtitle C system after the date of enactment of the Hazardous and Solid Waste Act
(HSWA) Amendments on November 8, 1984. EPA declined to include newly identified wastes
within the scope of the Land Disposal Restrictions (LDR) for Subtitle C characteristic hazardous
wastes (the "Third Third" rule) published on June 1, 1990, deciding instead to promulgate
additional treatment standards (Best Demonstrated Available Technology, or BOAT) in several
phases that would be completed in 1997 (55 FR 22667). EPA subsequently developed BDAT
treatment standards that must be met for characteristic hazardous mineral processing wastes.
5.4 Coastal Zone Management Act
For mining operations proposed in areas that lie within a particular state's coastal zone, a
consistency determination with respect to that state's Coastal Zone Management Plan (CZMP)
will likely be required. The state agency responsible for implementing the federal Coastal Zone
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Management Act in that particular state must concur that the proposed operation is consistent
with the state's CZMP. The state's concurrence with the consistency determination may in turn
require coordination with other state permitting agencies as well as at the local level where
elements of such plans are often developed. Prospective mine operators are encouraged to
identify and contact the appropriate state officials early in the mine planning process so that the
CZMP consistency determination can run concurrent with other regulatory processes. State
government websites are a good source of information for state regulatory programs, including
coastal zone planning requirements.
5.5 State Authorities
EPA is not responsible for implementing all or even most environmental programs. All Federal
environmental programs, including the Clean Water Act, the Clean Air Act, and many other
statutes, provide for State assumption of implementation authority upon passage of conforming
laws, development of appropriate regulations, and establishment of adequate mechanisms for
implementation. Table 7 shows the delegation status of all the major Federal environmental
programs in EPA Region 10, as of early 2003. Because NEPA is not a regulatory program but
rather places an obligation on Federal agencies to comply, there is no "authority" that can be
delegated under NEPA.
Table 7. Delegation and Authorization of Federal Environmental Programs
to States in EPA Region 10 (see note 1)
Statute/Program
Alaska
Idaho
Oregon
Washington
Clean Mr Act
NSPS
NESHAPS
NSR
PSD
MACT NESHAPS
Acid Rain
Title V (note 2)
SIPS (note 3)
Partial delegation
Partial delegation
Full delegation
Full delegation
Partial delegation
n/a
Interim approved
Ongoing approvals
Partial delegation
Partial delegation
Full delegation
Full delegation
Partial delegation
Full delegation
Interim approved
ongoing approvals
Partial delegation
Partial delegation
Full delegation
Full delegation
Partial delegation
Full delegation
Full delegation
Ongoing approvals
Partial delegation
Partial delegation
Full delegation
Partial delegation
Partial delegation
Full delegation
Full delegation
Ongoing approvals
Clean Water Act
NPDES permitting
Pretreatment
Sludge
Not delegated
Not delegated
Not delegated
Not delegated
Not delegated
Not delegated
Full delegation
Full delegation
Not delegated
Full delegation
Full delegation
Not delegated
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Table 7. Delegation and Authorization of Federal Environmental Programs
to States in EPA Region 10 (see note 1)
Statute/Program
Federal facilities
Wetlands
Alaska
Not delegated
Not delegated
Idaho
Not delegated
Not delegated
Oregon
Full delegation
Not delegated
Washington
Not delegated
Not delegated
Emergency Planning and Community Right-to-know Act
§§311 &312
Not delegated
Not delegated
Not delegated
Not delegated
Federal Insecticide, Fungicide, and Rodenticide Act
Enforcement (note 4)
Full delegation
Full delegation
Full delegation
Full delegation
Resource Conservation and Recovery Act
Base program (note 5)
Corrective action
Boilers & Industrial
Furnaces
Toxicity
Characteristics Rule
Land Disposal
Restrictions
Underground Storage
Tanks
Not delegated
Not delegated
Not delegated
Not delegated
Not delegated
Not delegated
Full delegation
Full delegation
Full delegation
Full delegation
Partial delegation
Not delegated
Full delegation
Full delegation
Full delegation
Full delegation
Partial delegation
Not delegated
Full delegation
Full delegation
Not delegated
Full delegation
Partial delegation
Full delegation
Safe Drinking Water Act
UIC Class II wells
UlCCIassI, III, IV, V
PWS
Full delegation
n/a
Full delegation
n/a
Full delegation
Full delegation
Full delegation
Full delegation
Full delegation
n/a
Full delegation
Full delegation
Toxic Substances Control Act
Lead
Not delegated
Not delegated
Full delegation
Not delegated
Notes:
n/a = not applicable
1 Partial and full delegations of programs to States do not apply in Indian Country, where EPA retains full
responsibility
2 Generally, States are implementing and carrying out a majority of the program but are constantly
updating their rules and EPA must approve before the State can fully implement.
3 Interim approved means EPA has approved the State to implement but some revisions are needed
before the final/full approval can be given.
4 FIFRA delegation is for use violations only. Other Federal violations are referred to EPA.
5 pre-HSWA program
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Besides Federal programs that may be delegated to States, many States implement
programs specific to mining operations that have no direct EPA nexus. These generally require
State permits for various aspects of mining operations and closure, oversight of most or all
aspects of mining operations, and reclamation of mine sites to State- and site-specific standards.
All States in EPA Region 10 have laws that require hardrock mining reclamation, and that
require some sort of financial assurance that reclamation can be achieved at the end of active
operations.
These programs are not described in this Source Book, since EPA has no direct role in
their implementation. Most States have placed detailed information on these programs on their
websites.
EPA notes, however, that state permit programs, including bonding programs, can be an
important factor in providing mitigation for predicted impacts, and can be crucial in ensuring
that proposed mitigation measures will actually be implemented. For these reasons, EPA
considers State regulatory and permit requirements, as well as bonding requirements, to be
important factors in its evaluation of potential impacts under NEPA
6.0 EPA EXPECTATIONS FOR MINING IMPACT ASSESSMENT
As discussed in Section 4, EPA's primary direct responsibilities in Region 10 typically
relate to NPDES new source permitting of mines under the CWA and associated NEPA review.
At the same time, many of the most significant issues regarding potential environmental impacts
from new mining operations involve water resources, aquatic habitat, jurisdictional wetlands and
other waters of the U.S. Consequently, EPA expects applicants to have a thorough
understanding of the hydrological and aquatic environment in which they are proposing to work.
The NEPA review and CWA permitting processes will require that an applicant collect a variety
of data, conduct different types of analyses, and develop preliminary facility and operational
designs to define potential consequences on water resources. Examples of the types of data,
testing, and analysis that may be required are given in Tables 8 through 11. Tables 8 through 11
in turn refer to the technical appendices for more details. A general discussion of information
needs related to predicting impacts to surface water, ground water, and wetlands resources are
presented in the following sections.
6.1 Impacts to Surface and Ground Water Hydrology
Applicants need to address whether and to what extent their proposed project will affect
the surface water and ground water hydrology at the mine site and within the watershed. To
determine potential hydrological impacts will require collection and analyses of a variety of
meteorological and hydrological data (see Table 8), preparation of operation phase and closure
phase water balances (see Table 11), and wastewater and storm water management plans.
Information regarding surface water discharge, precipitation, and the duration and intensity of
storm events are especially critical to this process. This is because most proposed sites are
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located in mountainous, coastal, or subarctic areas where there are significant annual and
seasonal variations in climate that make it difficult to develop data sets that are representative
and statistically significant. To overcome the problems associated with high short-term data
variability requires a long-term record. However, most sites are likely to be proposed in remote
areas for which long-term records of discharge and climate are unlikely to be available either for
the watershed of interest or for nearby watersheds possessing similar physical characteristics.
Consequently, in order to gather data for as long as possible, applicants should establish stations
to monitor stream discharge and meteorological conditions during the early stages of site
exploration. Information and analyses necessary to determining impacts to surface water and
ground water hydrology is discussed in the following sections and in more detail in Appendix
A, Hydrology.
6.1.1 Surface Water Hydrology
A proposed mining project can impact the quantity and velocity of surface water flow by
altering natural drainage patterns and the infiltration/runoff relationships in a watershed;
discharging storm water and wastewater; impounding water; changing the character of gaining
and losing stream reaches through mine dewatering; mining through stream channels and flood
plains; and by diverting, re-routing, and channelizing streams. Importantly, many mining
activities have the potential to alter the equilibrium balance between flow and sediment transport
in streams (Johnson, 1997). Altering this equilibrium causes stream gradients, channel
geometries, channel patterns, and stream banks to adjust to new equilibrium conditions that
reflect new erosion and sediment transport characteristics (Johnson, 1997). Such changes can
disrupt aquatic habitats both upstream and downstream of a mine. The creation of waste dumps,
tailings impoundments, mine pits and other facilities that become permanent features of the post-
mining landscape can cause fundamental changes in the physical characteristics of a watershed
(O'Hearn, 1997). Consequently, applicants may be required to assess the effect of these changes
on the post-mining hydrological environment.
Most applicants will be required to complete hydrological studies and a site water
balance in order to predict impacts to surface water hydrology. These studies and their
associated data needs are summarized below and are described in more detail in Appendix A,
Hydrology.
The hydrological study should provide a baseline from which to measure or predict
relevant changes that might occur as a consequence of the proposed action and its alternatives.
In order to place the project within the context of its watershed, the study should have a scope
that extends beyond the boundaries of the proposed mine site. As part of the study, applicants
should:
Characterize both surface and subsurface flow regimes and surface-ground water
interactions on a seasonal or monthly basis. Identify critical low flow conditions.
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Table 8. Data Needs for NEPA Review and CWA Permits
Resource Area
Climate
Geology and Soils
Surface Water
Hydrology
Ground Water
Hydrogeology
Surface Water and
Ground Water
Quality
Effluent Quality
Wetlands & Waters
of the U.S.
Aquatic
Data Needs
Average annual precipitation; Monthly precipitation distribution;
Mean monthly temperature; Mean monthly evaporation; Storm
characteristics (precipitation rates); Orographic effects.
Lithology and mineralogy of rocks, soils, and alluvial deposits;
Rock unit distribution; Structural relations; Fracture distribution &
characteristics; Alteration and mineralization, including vertical
and lateral changes; Surface-subsurface relationships;
Topography and slopes; Soil cover (depth and type).
Watershed delineation; Flood plain delineation; Identification of
special designation waters; Stream gradient, channel
morphology, channel pattern; Stream flow/sediment transport
relations; Stream flows (average monthly flow, critical low flows);
Flood frequency; Precipitation/infiltration/ runoff relations;
Gaining/losing reaches; Surface water usage.
Aquifer delineation; Aquifer characterization (storage, direction
of flow, gradient, permeability, transmissivity); Water table
elevation and its variability; Recharge zones; Confining layers;
Seeps & springs; Depth of permafrost thaw; Ground water
usage.
Background surface and ground water quality; Existing surface
and ground water quality; Relationship of surface water quality to
changes in flow
Expected quality of effluents and variability of effluent quality
over range of operating conditions; Expected flow of effluent and
variability of flow over range of operating and climatic conditions
Delineation of wetlands & waters of the U.S.; Wetlands
classification; Designation of riparian habitat & corridors;
Narrative descriptions that include nature, extent, functions, and
value.
Fish and macroinvertebrate population and diversity data;
Aquatic habitat characterization; aquatic mammals and
amphibians; Threatened, endangered, or sensitive species.
Appendix
A
C
A, B
A, F
A,B
D
1
G
Distinguish the effects that any current or historic activities, including mining
activities, have had on the hydrology of the project area
Determine the extent to which different physical variables within the watershed
control hydrological processes
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• Prepare an analysis of meteorological records that describes the seasonal
variability, frequency, and intensity of storm events.
The baseline study should provide adequate data to evaluate whether the proposed mine
operation and considered alternatives could alter the hydrology of a watershed. This analysis
requires characterization of several watershed geomorphological and other characteristics, such
as basin slope, vegetative cover, soil type and land use conditions. In addition, applicants need
to demonstrate how construction of the proposed mine and its associated facilities might alter
runoff responses to both average and extreme precipitation events. Impacts to seasonal flow
regimes and channel morphology (i.e., channel bed and bank erosion and sediment transport
capacity) that can be caused by stream diversions, channelization, and altered drainage patterns
need to be defined. Effects on surface water discharge, and impacts to spring-fed wetlands or
stream reaches from mine dewatering activities should also be quantified.
Applicants must determine whether their proposed operation will result in discharges to
waters of the U.S.. An accurate assessment is accomplished by developing a thorough
understanding of local and regional hydrology and formulating a reliable water balance. An
adequate water balance superimposes the flow of process system waters (i.e., the process circuit)
on the natural hydrology within the watershed and describes the management of storm runoff,
flood flows, and process and storm water discharges on a seasonal or monthly basis. The water
balance should cover the range of hydrologic conditions (extreme and average) and potential
variations or disruptions in process flows (e.g., temporary suspension of operations as well as
closure). The site water balance is used to determine whether a proposed mine would have a net
gaining system that may require continual or periodic discharges.
Table 9. Testing Needs for NEPA Review and CWA Permits
Resource Area
Solid waste
characterization (e.g.,
Waste Rock, spent
heap leach & Tailings)
Rock, Soils &
Sediment
Characterization
Water Quality
Characterization
Hydrologic
Characterization
Testing Needs
Grain-size distribution; mineralogy, Total and sulfide sulfur
content; Acid generating potential; Acid neutralizing potential;
Kinetic test; leach tests; Total metals content; Leachate
compositions; Tailings water compositions.
Proctor moisture/density; Atterberg limits; Grain-size analysis;
Direct shear; Permeability; Total metals content; Acid
generating potential; Acid neutralizing potential; leach tests.
Major cation and anion concentrations; Metals concentrations
(total and dissolved); pH; conductivity; Redox potential;
Temperature; Total hardness; Total alkalinity; TDS; TSS;
Dissolved oxygen, Whole effluent toxicity (WET) tests.
In situ hydraulic conductivity; Monitor well logs; Drawdown
studies; Aquifer transmissivity and storage.
Appendix
C
C,F
A,B, D
A
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Table 10. Preliminary Design Needs for NEPA Review and CWA Permits
Resource Area
Mine Operation
Infrastructure
Beneficiation
Waste Disposal
Process Water
Management
Storm Water
Management
Closure and
Reclamation
Preliminary Design Needs
Mine plan; Facilities layout.
Road locations and construction; Stream crossings; Fuel
storage; Borrow areas; Water and wastewater treatment plants.
Mineral processing methodology; Reagent storage; Facility
construction; Conveyance systems; Ore and concentrate
stockpiles.
Tailings impoundments and piles; Waste rock and spent ore
dumps; Overburden storage areas.
Process water flow chart; Storage ponds; Conveyance
structures; water balances
Diversion structures; Conveyance structures; Retention ponds.
Best Management Practices; Heap leach neutralization and
rinsing; Revegetation mixes; Grading and recontouring; Natural
and synthetic covers; Facility removal; Pit wall or mine tunnel
stabilization.
Appendix
-
-
-
F
D,E
E
E, F, H
Methods to measure and predict hydrological impacts and develop a site water balance
are described in Appendix A, Hydrology. Region 10 recognizes that many mines proposed in
northern and central Alaska are likely to be situated in areas underlain by permafrost. In these
terrains, stream flow and precipitation-infiltration-runoff relations vary seasonally due to winter
freeze. Applicants proposing to work in these areas should give special consideration to their
unique hydrological characteristics and to seasonal variations.
6.1.2 Ground Water Hydrogeology
A proposed mining operation can impact the availability and flow of ground water by
locally lowering the water table through dewatering operations; disrupting aquifers; locally
removing confining layers; and altering zones of natural recharge (Brown, 1997). Mining
activities also create opportunities for ground water contamination by exposing aquifers and
puncturing aquitards. Alteration of ground water flow direction or reduction in the water table or
potentiometric surface can potentially impact wetlands, aquatic habitats, and stream discharge
characteristics.
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
Most applicants will be required to submit a detailed hydrogeologic study of the region in
which they are proposing to operate. This study and its associated data needs are summarized
below and described in detail in Appendix A, Hydrology.
Table 11. Data Analysis Needs for NEPA Review and CWA Permits
Resource Area
Waste Rock & Tailings
Disposal Impact
Surface Water &
Ground Water Quality
Impact
Hydrological Impacts
Wetlands & Aquatic
Life Impact
Data Analysis Needs
Predict short- and long-term acid generating potential and
metals leachability; rates of seepage and run-off; predict
stability of piles, impoundments, and backfill
Statistical analysis of water quality data; Estimated effluent
discharge composition; Estimated seepage composition;
Projected effects of discharge on ground and surface water
quality; Estimated pit-lake water quality; Projected likelihood of
ground and surface water quality impacts from spill events.
Ground-water models used to assess impacts should be
updated annually through operations and the impacts
determination should be modified if the model changes
significantly.
Facility water balance; Design storm models; Watershed model
(e.g., HEC-1); Flow duration curves; Pit lake development
model; Ground water flow model (e.g., MODFLOW); Storm
water flow model; Sediment erosion and transport model;
Dewatering, drawdown, and recovery; Changes in recharge
characteristics.
Calculated impacted acreage by wetland type, loss of function
and value. Potential impacts on fish and macroinvertebrate
populations through toxicity, reduced flow, and habitat loss.
Appendix
C,F
A,B,D
A,H
B,I,G
The hydrogeological study should provide a baseline from which to measure or predict
changes that might occur as a consequence of the proposed action and its alternatives. The
boundaries of the study have to be defined on site specific basin, and may need to encompass the
entire watershed. As part of the study, applicants should:
Identify aquifers and confining layers and their vertical and lateral extent
Determine the types of aquifers (confined or unconfmed), aquifer characteristics
such as hydraulic conductivity, primary and secondary porosity, storage
coefficients, and hydraulic gradient, and hydraulic communication, if any, with
surface water or other ground waters
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• Characterize each confining layer and its physical properties
Determine the depth to water, the configuration of the water table or
potentiometric surface, and the hydraulic gradient and flow direction
• Where required, quantify the seasonality of ground water flow in permafrost
terrains
• Distinguish the effects that any current or historic activities, including mining
activities, may have had on the hydrogeology of the project area.
Region 10 expects applicants to provide analyses of potential impacts to ground water
resources caused by water use and mine dewatering. Dewatering of surface and underground
mines can deplete aquifers, impact ground water recharge and discharge, and locally change the
direction of ground water flow. For these reasons, data collected for hydrogeological studies
should be used to conduct an analysis of the potential impacts of drawdown. This analysis
should determine the extent that ground water levels or specific yield would be affected and
whether lowering of the water table or reducing the potentiometric surface would impact spring
flow, wetlands, gaining stream reaches, or other ground water users. In some cases, an analysis
of geotechnical effects caused by drawdown may be required to adequately design mine
facilities, impoundments, embankments, and foundations. For example, dewatering a
comparatively thick, unconsolidated alluvial aquifer that overlies an undulating bedrock surface,
could cause differential compaction, consolidation, and uneven surface subsidence. These
effects could threaten the geotechnical stability of facilities such as tailing dams and the integrity
of engineered structures such as process pond liners. Data collected during dewatering
operations should also be used to predict the rate at which the ground water system is expected
to recover following active operations.
Hydrogeologic studies conducted in terrain underlain by permafrost will need to
characterize the conditions unique to this sensitive environment. Included are the seasonality of
ground water flow in the near surface environment, the depth of annual thaw, potential
connections between shallow and deep (below the permafrost layer) ground waters, the
importance of vegetative layers, and the potential for mining-induced thawing of frozen
materials (either by excavation of insulating vegetation or rock layers or construction of
permanent facilities such as tailings impoundments).
The hydrogeologic study should provide a basis for assessing the recovery of the ground
water regime following mining. This includes estimating the rate at which ground water levels
would recover and describing potential effects caused by the formation of pit lakes, the
disruption of recharge zones (especially those associated with confined aquifers), the influx of
seepage waters from permanent mine facilities (e.g., tailings impoundments), the removal of
confining layers, the disruption of aquifer continuity, and the back-filling of mine pits (Siegel,
1997).
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6.2 Impacts to Water Quality
Impacts to surface and ground water quality can occur from discharges of storm water,
mine drainage, and process water. This section summarizes information needs regarding
potential impacts to water quality. Appendices A and B provide detailed guidance for
characterizing hydrology and receiving water quality at the appropriate watershed scale.
Two issues that applicants will be required to address during the NEPA review and CWA
permitting processes are whether the proposed project is expected to lead to a discharge of
wastewater and whether the proposed project would create short- or long-term impacts to surface
or ground water quality. EPA places great emphasis on evaluations of potential wastewater
discharges because once mining operations have been initiated, discharges often cannot be
stopped or reduced if the effluent does not meet water quality standards. Historically, the most
problematic discharges occur from major mine components that are exposed to the atmosphere,
such as mine pits, waste rock dumps, tailings impoundments, and leach facilities. Because mine
wastes will be exposed to the elements long after mine closure, the potential for the release of
metals, acid, cyanide, sediment, or other contaminants from a mine site must be accurately
analyzed. Evaluating the potential for long-term risk from waste disposal practices is a difficult
task but it is of primary importance to demonstrating compliance with the CWA and in
disclosing accurate information to the public. Factors associated with evaluating long-term
impacts include:
• Characteristics of waste rock, tailings, and other waste materials
Facility design and construction
Beneficiation and processing methods
• Local meteorological and hydrological conditions
Solid waste and wastewater management methods
• Closure and reclamation methods.
Determining potential impacts to water quality typically requires applicants to collect a
variety of data, conduct numerous geochemical tests, develop preliminary mine plans and facility
designs, and perform different types of data analyses. In general, applicants should anticipate
that they may be required to provide studies that characterize:
• Background surface and ground water quality within the watershed hosting the
proposed operation
Background surface water hydrology and ground water hydrogeology in the
watershed of interest
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• Expected hydrologic, physical, and geochemical behavior of waste rock piles,
heap leach piles, and tailings impoundments, and other waste materials during
operation and following closure
Chemical compositions of process waters, mine drainage, and treated and
untreated effluent
• Effectiveness of rinsing, neutralization, and closure and reclamation methods
employed for these facilities
Each of these items are discussed in the following subsections.
6.2.1 Background and Existing Water Quality
Methods to determine background and existing water quality in a watershed are discussed
in Appendix B, Receiving Waters; testing needs and data analyses are summarized in Tables 9
and 11, respectively. As described in the appendix, applicants should employ robust statistical
techniques to analyze background metals and other constituent concentrations in different
portions of a potentially impacted watershed, quantify the magnitude of seasonal variability in
water quality and variation associated with high and low stream flow conditions, and evaluate
water quality under the conditions of highest risk (i.e., reasonable worst-case conditions).
Adequate quality assurance and quality control should be demonstrated. For example, analytical
methods employed must be sensitive enough to measure the parameters of concern at levels at or
below the water quality criteria.
6.2.2 Regional Hydrology and Hydrogeology
The hydrology and hydrogeology studies described in Section 6.1 should provide data to
evaluate potential future water quality impacts. Applicants for NPDES permits should develop a
surface water management plan and site water balance that also can be used when evaluating
potential water quality impacts.
6.2.3 Hydrology of Mines and Waste Facilities
Predictions of whether and when a mine or waste disposal facility may begin to generate
acidic water or to release metals or other constituents are related to the flow of fluids through the
facility, the compositions of these fluids, the compositions of the materials with which the fluids
are in contact, and the chemical environment in which the fluids exist. Accurate predictions of
effluent flow rate and discharge composition require knowledge of waste characteristics, surface
and ground water hydrology, effectiveness of proposed surface water and ground water controls,
final unit construction and closure methods, climate, geochemical equilibrium, and other
variables that may be difficult to determine during the permitting process. Consequently,
applicants for mines that could generate acid or mobilize metals should employ facility designs
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that minimize infiltration and seepage and use conservative estimates for acid generation
potential, rainfall, and leachate composition to determine future impacts.
In general, the hydrological and hydrogeological studies described in Section 6.1, and in
more detail in Appendix A, will provide data to determine the likelihood that lakes will form in
open pits and that underground workings will flood when mining ceases. Although the rate at
which lake filling or underground flooding is expected to occur can be estimated from
knowledge of pre-mining ground water flow, data collected during actual dewatering operations
can be used to provide a clearer picture of the expected post-closure conditions.
The long-term hydrological behavior of waste rock dumps and tailings impoundments
depends on factors such as construction method, grain size and sorting of the waste materials,
secondary mineral formation, and closure and reclamation methods (Blowes et al., 1991; MEND,
1995; Swanson et al., 1998). Predicting seepage rates can be difficult, especially for facilities
that are likely to be partially saturated, such as those located in dry climates (Swanson et al.,
1998). Generating acceptable model simulations is even more complicated for facilities
constructed in such a way that they are physically heterogeneous (e.g., discontinuous layers of
coarse and fine waste rock) (Swanson et al., 1998) or within which layers of secondary mineral
cements formed during weathering (Blowes et al., 1991). More detail regarding the prediction of
hydrologic impacts of waste rock dumps and tailings impoundments is provided in Appendix F,
Solid Waste Management and Appendix A, Hydrology.
6.2.4 Solid Waste and Materials Characterization and Management
Applicants will need to demonstrate that they have adequately characterized their waste
materials and the potential for these materials to contribute to discharges to surface waters and
groundwater. Tests commonly used to characterize bulk chemical and physical composition,
metals teachability, and acid-generating potential are summarized in Tables 9 and 11 and
described in Appendix C, Characterization of Ore, Waste Rock, and Tailings. Because there are
many different tests available to determine teachability and acid-generating potential and no
single accepted way of interpreting test results, applicants should consult with federal and state
regulatory agencies to enquire whether specific test methods are preferred.
Applicants should demonstrate that the samples characterized are representative of
material that will be produced during operations. There are no set guidelines for determining the
number of samples that should be tested. Recent studies suggest that the number of tested
samples should be determined by the compositional variability of the materials that will be
disposed of (Shields et al., 1998) — this has long been understood in terms of characterizing ore
grade, and applicants should apply the same care in characterizing environmental samples.
Applicants are expected to describe the variability inherent in different lithological units across
the project area (e.g., homogeneous, unzoned granite vs. heterogeneous colluvium) and that may
have been imparted to a lithological unit through weathering, hydrothermal alteration, and
mineralization. Applicants will need to consider how vertical and lateral changes in the intensity
and style of mineralization and host rock alteration affect the acid generating characteristics and
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metals leachability of each geologic unit at the proposed mine site. Because compositional
variability equates primarily to mineralogical variability, applicants can use inexpensive
examinations (e.g., mineralogical analysis by x-ray diffraction, possibly followed by
petrographic microscope) to quantify the range and median proportions of acid-forming, acid-
neutralizing, and metal-bearing constituents in the various lithological units that will be
encountered. Testing programs can then focus on characterizing the expected behavior across
the compositional range identified for each rock type.
For many large-scale operations, it may be appropriate to formulate composite test
samples which represent waste rock and overburden materials as they are likely to be excavated
and handled during the mining operation. It is important that composite samples be created in a
manner representative of the proposed operation.
Tailings test samples should be taken from pilot-scale metallurgical tests representative
of the operation that will be employed during full-scale operation. Applicants should test ore
samples that capture the range of ore grades that will be processed during the life of the mine.
Of particular concern to EPA and the public is the potential for waste rock, tailings, and
heap leach materials to generate acidity and release metals after protracted exposure to the
environment. Tests of several years duration conducted on mine materials indicate that
acidification may occur after periods of neutral drainage lasting one to two years (Lapakko et al.,
1998), even in the accelerated weathering environment of the lab. Applicants should recognize
that static acid-base accounting tests provide information only on the relative proportions of
acid-forming and acid-neutralizing components in a sample and provide no information
regarding the rates at which these reactions are expected to occur. Information regarding the
latter can only be obtained by kinetic tests that are conducted for a sufficiently long time.
Kinetic tests typically are conducted for 20-week periods; however, there is a trend toward using
longer test times (Price et al. [1997] advocate 40-week tests) that would be viewed favorably by
Region 10.
The results of static and kinetic tests are particularly sensitive to the test method and
laboratory technique. EPA Region 10 encourages applicants to conduct all tests using the same
test method and testing laboratory. In addition, although not specifically stated in most kinetic
test procedures, Mills (1998) points out that it is typical for splits of the starting kinetic sample
and final leached product to be tested for static acid-base properties and total metals.
Mineralogical analyses also should be conducted on these samples because these data can
provide important constraints to assist the interpretation of test results.
Interpreting the results of leach tests, static acid-base accounts, and kinetic tests is not
straightforward and there are no generally accepted criteria for doing so (see Appendix C). This
is because the conditions simulated by the tests inevitably will deviate from the environment in
which wastes will be disposed and because many test methodologies require that samples be
crushed or ground to particle sizes significantly finer than produced by the mining operation
(Doyle et al., 1998; Lapakko et al., 1998). Changes in particle size are particularly important,
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because crushing alters the exposed surface areas of both acid-forming and acid-neutralizing
materials, which in turn affects reaction rates and availability (Lapakko et al., 1998). To ensure
that interpretations of geochemical test results are appropriately conservative, applicants should
carefully consider the representativeness of the tested samples, the similarities and differences
between the test conditions and site environment, and the significance of any temporal changes
in leachate compositions noted over the course of the tests. In addition, specialized knowledge is
required for proper evaluation of the characterization results, and applicants need to ensure that
their data are evaluated by individuals with this knowledge.
Applicants should also provide information useful for predicting impacts on water
quality. These include information on the effects of previous mining, pre-mining water quality,
and relevant geologic factors (e.g. rock type, effects of surface weathering). This type of
information can be particularly valuable in identifying the potential for metals leaching in the
absence of acidic conditions.
Management of solid wastes and information needs related to NEPA analyses of potential
impacts due to solid waste are discussed in Appendix F, Solid Waste Management. Applicants
proposing operations that will produce acid- or metals-generating waste rock or tailings should
provide design elements that will limit potential environmental impacts from these materials.
These could include steps to minimize the production of potentially reactive wastes, separation
and special handling of these materials, blending acid-generating and neutralizing materials,
and/or reclamation designed to isolate these wastes from the environment.
6.2.5 Wastewater Quality and Management
The NPDES permit process requires applicants to identify sources of wastewater and
storm water, describe wastewater and storm water management, provide water balances, and
estimate the quantities and compositions of effluents that would be discharged through permitted
outfalls throughout the year (see Table 5). Applicants must demonstrate that the wastewater
characterization is representative of discharges that will occur over the full range of operating
conditions and closure and that any effluent proposed for discharge will not result in water
quality standards exceedences in the receiving water. In order to accomplish this, applicants will
need to estimate the quantities and compositions of process solutions, tailings water, runoff
waters, mine drainage, and treated effluent at the proposed operation and the effectiveness of
wastewater management measures (such as treatment).
Wastewater quality and quantity from tailings impoundments and operating heap leach
facilities may be determined from analysis of process solutions and tailings waters obtained from
pilot-scale metallurgical tests that simulate the proposed processing operations. Discharges from
waste rock piles and mine drainage may be predicted based on geochemical testing and
modeling. For operations proposed in areas of historic mining activity, samples of mine
drainage should be collected from pit lakes, underground workings, tailings ponds, or seeps
emanating from existing waste disposal facilities. Where wastewater treatment is proposed, the
quality of treated effluent should be determined from pilot-scale tests of the proposed treatment
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technology. Wastewater management, including discussions of treatment processes, treatability
studies, methods for disposal, and data needs for NEPA analyses are discussed in Appendix E,
Wastewater Management. Methods to predict discharge effluent quality are described in
Appendix D, Effluent Quality.
6.2.6 Post-Closure Mine and Waste Facility Water Quality
Predictive assessments of post-mining pit lake or underground water quality and tailings
impoundment water quality will likely be required by the NEPA process. Predictions may be
made based on results of geochemical testing and modeling. There may be a high degree of
uncertainty associated with predictive modeling. Stochastic models, those containing
information regarding parameter uncertainty, are gaining wider acceptance as predictive tools
(Schafer and Lewis, 1998). Where models are used, assumptions and uncertainties associated
with the model and input parameters must be identified. It is also beneficial for the Applicant to
make sure in advance that the model will be accepted by the regulatory agencies.
Mining activities that disrupt ground water geochemical systems can spur mineral
dissolution or precipitation reactions that can alter pre-mining ground water quality in ways that
may be difficult to predict (Lewis-Russ, 1997). Mine pits that are backfilled with waste rock and
underground workings that are abandoned following ore extraction increase the opportunity for
contamination by exposing ground water to fresh rock surfaces that are not in equilibrium with
the existing geochemical system. In these situations, applicants should provide an assessment of
potential ground water quality impacts in these settings.
More detail regarding predictive water quality models is provided in Appendix D and
Appendix A.
6.2.7 Closure and Reclamation Effects
The methods used for facility closure and reclamation can play an important role in
determining the potential for long-term contamination. Residual leach fluids or soluble metal
complexes that remain in inadequately rinsed or neutralized heaps can lead to seepage of metals-
laden acidic or cyanide-rich fluids. However, low permeability caps, covers, and capillary
barriers installed following recontouring can lower the risk of long-term contamination by
helping to reduce infiltration and chemical flux through the embankment. In addition,
adequately established vegetation cover would reduce erosion and aid in the evapotranspiration
of water from surface layers. Caps and covers also can help to limit oxygen diffusion into
sulfide-bearing waste materials. Grading and recontouring of facility slopes can reduce the
potential for long-term erosion, slope failure, and sedimentation in surface waters. Other Best
Management Practices (BMPs) may be employed to minimize contamination due to
sedimentation and erosion (see Appendix H). Applicants will be required to develop preliminary
closure and reclamation plans for NEPA review which should address whether or not an NPDES
permit will be required for any post-closure discharges. Closure considerations and related
NEPA disclosure needs are discussed in more detail in Appendix F, Solid Waste Management
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and Appendix H, Erosion and Sedimentation. In addition, information on expected post-mining
water quality should be provided for the NEPA analysis.
6.3 Impacts to Aquatic Resources
Freshwater aquatic resources represent an important component of the environment that
must be analyzed for NEPA review and CWA permitting processes. Considerable overlap exists
between studies analyzing aquatic resources and those characterizing surface water and ground
water quality and hydrology. Many impacts to aquatic resources, including riparian areas, are
related to mine construction and the location of facilities. Road construction, logging, and
clearing of areas for buildings, mills, and process facilities can reduce infiltration and increase
the amount of surface runoff which reaches streams and other surface water bodies while
potentially reducing stream base flows. This can increase the peak flow and the total amount of
stream discharge which occurs from a given storm event. Unusually high peak flows can cause
erosion of stream banks, widening of primary flow channels, erosion of bed materials,
channelization, and alteration of the slope of the channel. These impacts can affect and degrade
aquatic habitats, including riparian zones. Channelization (i.e., straightening) can increase flow
velocities in a channel reach, potentially affecting fish passage to upstream reaches during
moderate to high stream flows. Increased erosion and downstream sedimentation can impact
spawning gravels, egg survival, and frye emergence, as well as degrade benthic food sources and
riparian cover. Flooding can create high velocity flows, scour stream banks and erode or bury
gravel substrates. The destruction of cover created by large woody debris and stable banks can
impact rearing and resting habitat for fishes. In addition, removing riparian vegetation can
reduce shading. The resulting increase in sunlight can raise the temperature at the surface and
through the entire water column, and this in turn can have a profound impact on the entire
aquatic ecosystem.
Water quality issues associated with mine exploration, operation, and abandonment
activities typically involve the potential discharge of mine water and process solutions, increased
loads of metals and other toxic pollutants, acid generation from waste rock, spent ore, and mine
workings. If these pollutants reach surface waters, toxic conditions could affect important
aquatic species.
Studies that are typically required for NEPA review and often CWA §404 permitting
include analyses offish, benthic macroinvertebrates, and the physical parameters, including the
riparian zone, that define habitat for aquatic communities. In the NEPA process, aquatic
resources, especially fish, often represent significant issues for the proposed action being
evaluated. This is because resident and anadromous fisheries represent a concern to the public
and governmental agencies such as NMFS, BLM, USFWS, U.S. Forest Service (USFS), Tribal
governments, and state wildlife agencies. Many fish species, particularly salmonids (trout and
salmon), have important recreational and/or commercial fishery values. Numerous species also
are Federally or state-listed species that require protection under the Endangered Species Act.
For these reasons, applicants should complete analyses to determine potential impacts to aquatic
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resources. Appendix G, Aquatic Resources provides detailed discussion of data needs and
outlines methods to design appropriate studies for aquatic resources.
The aquatic resources study should provide a baseline from which to measure or predict
relevant changes that might occur as a consequence of the proposed action and its alternatives.
As required under NEPA regulations, an impact assessment must analyze both direct, indirect
and cumulative impacts to important aquatic resources located within the project study area
(Council on Environmental Quality, 1986). The study should have a scope that extends beyond
the boundaries of the proposed mine site. Applicants should anticipate that they could be
required to provide studies that characterize or evaluate:
• Potential effects of water quality changes on aquatic communities and their
habitat that may result from mine operations, including point and non-point
source discharges, and changes in flow regimes. Parameters of concern may
include heavy metals, pH, total dissolved solids, cyanide and cyanide breakdown
products (e.g., ammonia, nitrogen compounds), and overall effluent toxicity.
• Potential effects of sedimentation on aquatic communities and their habitat as a
result of construction and operational activities.
Potential effects of physical disturbance or removal of aquatic habitat and
associated riparian area on aquatic biota.
Potential effects to aquatic biota from spills that occur during the transport or
storage of fuel, process chemicals, and other hazardous materials.
• Potential effects of stream flow changes on aquatic habitat and biota that result
from water withdrawals (both of ground and surface water), stream diversions, or
discharges.
Potential effects of physical blockages or barriers created by mine construction or
operation activities on fish movements. These evaluations should include
potential velocity barriers that can be created in diversions, culverts, or road
crossings which can affect fish passage through a stream reach.
These types of impact evaluations would normally include background studies that define
fish distribution, abundance and species composition, and critical habitat for spawning, frye
emergence, and juvenile rearing. These studies need to focus especially on game and species
listed as threatened and endangered (T&E) or special status. Fishery habitat studies should
include, among other factors, characterization of stream gradients, widths, depths, pool
frequency, substrate composition, instream and riparian vegetation, and the presence of large
woody debris. Background studies to characterize macroinvertebrate communities should define
species composition and abundance and provide community metric data, such as species richness
and species diversity.
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6.4 Impacts to Wetlands
Studies to define, delineate and determine potential impacts to wetlands and other waters
of the U.S. typically have more rigorous requirements than studies conducted to evaluate non-
wetlands because jurisdictional wetlands (and other waters of the U.S.) are regulated under
Section 404 of the CWA. In general, wetlands are aquatic areas within the landscape that
include swamps, marshes, fens, bogs, vernal pools, playas, prairie potholes, and riparian zones.
These features are considered to be "jurisdictional wetlands" if they exhibit specific conditions
of wetland hydrology, hydric soils and the presence of hydrophytic vegetation, as defined by the
accepted delineation method. The regulatory definition of wetlands and the criteria and
indicators used to identify them are discussed in detail in Appendix I, Wetlands and Other
Waters of the United States. Regulatory requirements as specified under §404 of the CWA are
discussed in section 3.0.
Wetlands may perform a variety of important physical, chemical and biological functions
including ground water recharge or discharge, flood storage, peak flood flow attenuation,
shoreline and channel bank anchoring, dissipation of erosive forces, sediment trapping, and
nutrient trapping and removal. Wetlands may also provide habitat for numerous plant, wildlife,
and fish species, including some that are listed as threatened and endangered (T&E).
Impacts to wetland areas can result from the construction and operation of mine and
facilities including construction and use of roads; site preparation for buildings, mills and
ancillary facilities; and the construction, use and maintenance of waste and storage facilities,
such as tailings impoundments and waste rock dumps. Impacts can occur either directly or
indirectly. Direct impacts include the removal or destruction of wetlands through dredging,
filling, or draining. Indirect impacts are those associated with increased runoff and erosion from
disturbed areas, increased sedimentation, and increased loadings of metals and other toxic
pollutants. Mining operations also can impact riparian areas, which may be destroyed or lost by
the construction of stream diversions or by altering drainage patterns within a watershed. Mine
dewatering activities may impact wetland hydrology and wetland functions by altering regional
ground water recharge and discharge characteristics.
Any proposed project or activity with a potential to impact wetlands, either directly or
indirectly, will be required to fully characterize this resource to establish baseline conditions, and
determine potential impacts. It is important to note that state and local governments may also
place restrictions on projects that could impact wetlands, regardless of their jurisdictional status
under CWA §404.
The wetland study should provide a baseline from which to measure or predict changes
that might occur as a consequence of the proposed action and its alternatives. Studies to
determine potential impacts to wetlands should be described in terms of acreage of absolute loss
(acres filled or drained) and in loss of wetland function. Applicants should anticipate that they
may be required to provide studies that characterize or determine:
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EPA andHardrock Mining: A Source Book for Industry in the Northwest and Alaska
• The classification of wetlands and their function both within and near the project
area
• The acreage of wetlands that will be directly impacted by fill or draining activities
The extent that changes in hydrology, drainage patterns, or stream discharges
would affect the hydrology of identified wetlands and the composition of
associated plant species
• The extent to which dewatering activities or ground water withdrawals would
affect wetland hydrology and function
Potential increased sediment loading to identified wetlands
Fate and transport of spilled process chemicals or hazardous wastes and the
potential for spills to impact wetlands
• Potential effects to aquatic and terrestrial wildlife habitat and habitat values from
impacted wetlands.
In conducting studies, applicants should specifically evaluate different mine layouts,
facility designs, and technologies to study the avoidance and minimization of environmental
impacts to wetlands. The Section 404(b)(l) guidelines indicate that 404 permits can only be
issued when no practicable alternatives exist that would have fewer adverse impacts to wetlands.
Where proposed activities cannot avoid impacts to wetlands, studies must demonstrate that
practicable steps have been taken to minimize potential adverse impacts. In some cases,
operators have been able to offset lost wetland acreage with developed wetlands, or by
upgrading/improving other wetlands.
7.0 REFERENCES
Blowes, D.W., Reardon, E.J., Jambor, J.L., and Cherry, J.A., 1991. The Formation and Potential
Importance of Cemented Layers in Inactive Sulfide Mine Tailings, Geochimica
Cosmochimica et Acta, vol. 55, pp. 965-978.
Brown, A., 1997. Groundwater Quantity. In: Marcus, J.J., ed., Mining Environmental
Handbook, Effects of Mining on the Environment and American Environmental Controls
on Mining, Imperial College Press, London, pp. 244-248.
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Council on Environmental Quality, 1986. Regulations for Implementing the Procedural
Provisions of the National Environmental Policy Act, Executive Office of the President,
40 CFR Parts 1500-1508.
Doyle, T.A., Murphy, S.F., Klein, S.M., and Runnels, D.D., 1998. A Comparison of Batch and
Column Leaching Tests of Mining Wastes, Society for Mining, Metallurgy, and
Exploration, Inc., Preprint 98-103, 5 pp.
Johnson, S.W., 1997. Surface Water Quality - Sediment. In: Marcus, J.J., ed., Mining
Environmental Handbook, Effects of Mining on the Environment and American
Environmental Controls on Mining, Imperial College Press, London, pp. 149-150.
Lapakko, K., Haub, J., and Antonson, D., 1998. Effects of Dissolution Time and Particle Size on
Kinetic Test Results, Society for Mining, Metallurgy, and Exploration, Inc., Preprint 98-
114,9pp.
Lewis-Russ, A., 1997. Ground Water Quality. In: Marcus, J.J., ed., Mining Environmental
Handbook, Effects of Mining on the Environment and American Environmental Controls
on Mining, Imperial College Press, London, pp. 162-165.
MEND, 1995. Hydrology of Waste Rock Dumps, Natural Resources Canada and the Mining
Association of Canada Mine Environment Neutral Drainage Program, MEND Associate
ProjectPA-1, July 1995.
Mills, C., 1998. Kinetic Testwork Procedures, Report posted on the Enviromine website,
http://www.enviromine.com/ard/Kinetic%20Tests/kinetic%20procedures.htm, viewed
October 14, 1998.
O'Hearn, J., 1997. Surface Water Quantity. In: Marcus, J.J., ed., Mining Environmental
Handbook, Effects of Mining on the Environment and American Environmental Controls
on Mining, Imperial College Press, London, pp. 221-225.
Price, W.A., Morin, K., and Hurt, N., 1997. Guidelines for the Prediction of Acid Rock
Drainage and Metal Leaching for Mines in British Columbia: Part II. Recommended
Procedures for Static and Kinetic Testing. Proceedings - Fourth International
Conference on Acid Rock Drainage, Vancouver, B.C., Canada, May 31 -June 6, 1997.
Schafer, W.M. and Lewis, M., 1998. Evaluating the Environmental Risk of Water Quality
Impacts at Mining Sites, Society for Mining, Metallurgy, and Exploration, Inc., Preprint
98-182, 9pp.
Shields, M.J., Runnells, D.D., and Jones, R.L., 1998. Methodology for Adequacy of Sampling
Mill Tailings and Mine Waste Rock, Society for Mining, Metallurgy, and Exploration,
Inc., Preprint 98-23, 2 pp.
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Siegel, J., 1997. Ground Water Quantity. In: Marcus, J.J., ed., Mining Environmental
Handbook, Effects of Mining on the Environment and American Environmental Controls
on Mining, Imperial College Press, London, pp. 165-168.
Swanson, D.A., Kempton, J.H., Travers, C., and Atkins, D.A., 1998. Predicting Long-Term
Seepage from Waste-Rock Facilities in Dry Climates, Society for Mining, Metallurgy,
and Exploration, Inc., Preprint 98-135, 7 pp.
U.S. Environmental Protection Agency, Office of Wastewater Management, 1996. NPDES
Permit Writers'Manual. EPA 833-B-96-003.
U.S. Environmental Protection Agency, Office of Water, 1982, The Development Document for
Effluent Limitations Guidelines and Standard for the Ore Mining and Dressing Point
Source Category. EPA 440/1-82/061.
U.S. Environmental Protection Agency, Office of Water, 1991. Technical Support Document for
Water Quality-based Toxics Control. EPA 505/2-90-001.
U.S. Environmental Protection Agency, Region 6, EID Handbook Guidance to Applicants for
New Source NPDES Permits. 1995
U.S. Fish and Wildlife Service and National Marine Fisheries Service, Endangered Species
Consultation Handbook. 1998
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