EPA/ROD/R08-02/068
2002
EPA Super fund
Record of Decision:
UPPER TENMILE CREEK MINING AREA
EPA ID: MTSFN7578012
OU04
HELENA, MT
06/28/2002
-------
Record of Decision
Upper Tenmile Creel Mining Area Site
Lewis & Clark County, Montana
June 2002
U.S. Environmental
Protection Agency
Federal Building
10 West 15 a, Street, Suite 3200
Helena, Montana 59626
Montana Department of
Environmental Quality
2209 Phoenix Avenue
Helena, Montana 59620
-------
Record of Decision
Preface
Upper Tenmile Creek Mining Area Site
Lewis and Clark County, Montana
The U. S. Environmental Protection Agency (EPA) and the Montana Department of
Environmental Quality (DEQ), in consultation with the U. S. Forest Service (USFS), present
this Record of Decision (ROD) for the Upper Tenmile Creek Mining Area National Priorities
List (NPL) Site (the "site") in Lewis and Clark County, Montana. The ROD is based on the
administrative record for the site, including the remedial investigation (RI), the
feasibility study (FS) , the RI/FS addenda, the human health risk assessment (HHRA), the
ecological risk assessment (ERA), the proposed plan, the public comments received, and EPA
responses to the comments. The ROD presents a brief summary of the RI and FS, actual and
potential risks to human health and the environment as identified in the HHRA and ERA, the
major alternatives considered by EPA, and the selected remedy. EPA has followed the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended
(42 United States Code [USC] §9601 et seg.), the National Contingency Plan (NCP [40 Code
of Federal Regulations Part 300] ) , and EPA guidance (EPA 1999a) in preparation of the ROD.
The purposes of the ROD are to:
• Certify that the remedy selection process was carried out in accordance with the
reguirements of CERCLA and, to the extent practicable, the NCP
• Outline the engineering components and remediation reguirements of the selected
remedy
• Provide the public with a consolidated source of information about the history,
characteristics, and risks posed by the conditions of the site, as well as a summary
of the cleanup alternatives considered, their evaluation, the rationale behind the
selected remedy, and the agencies' consideration of and responses to the comments
received
The ROD is organized into three distinct sections:
1. The Declaration section serves as an abstract for the key information contained in
the ROD and is signed by the EPA Regional Administrator or his designee and any
concurring agencies.
2. The Decision Summary section provides an overview of the site characteristics, the
alternatives evaluated, and the analysis of those options. The Decision Summary
also identifies the selected remedy and explains how the remedy fulfills statutory
reguirements.
3. The Responsiveness Summary section addresses public comments received on the
draft and final proposed plans and other information contained in the
administrative record.
-------
Declaration
This part of the Record of Decision (ROD) summarizes key information and contains the
formal authorizing signature page for the ROD.
Site Name and Location
This decision document has been prepared for the Upper Tenmile Creek Mining Area Site (the
"site") in Lewis and Clark County, Montana. The national Superfund database (i.e.,
CERCLIS) identification number for the site is MTSFN7578012. The site, southwest of
Helena, Montana, includes the upper Tenmile Creek drainage basin south of U.S. Highway 12.
The site covers about 53 sguare miles and contains 150 known abandoned or inactive mine
sites within or near the historic Rimini Mining District in the upper Tenmile Creek
watershed. The watershed serves as the primary source of water for the City of Helena.
Statement of Basis and Purpose
This decision document presents the selected remedy for the Upper Tenmile Creek Mining
Area Site in Lewis and Clark County, Montana. This document is issued by the U. S.
Environmental Protection Agency (EPA) , the lead agency for site activities, and the
Montana Department of Environmental Quality (DEQ), the support agency, in consultation
with the U. S. Forest Service (USFS). EPA and DEQ, in consultation with the USFS, selected
the remedy in accordance with the Comprehensive Environmental Response, Compensation, and
Liability Act, 42 USC §9601 et. seg., as amended by the Superfund Amendments and
Reauthorization Act (collectively, CERCLA), and EPA's Superfund regulations, the National
Contingency Plan (NCP [40 CFR Part 300] ) . DEQ concurs with the selected remedy.
The decision is based on the administrative record file for this site. The administrative
record and key documents are available for review at the EPA Montana Office, located at 10
West 15th Street, Suite 3200 in Helena, Montana. Copies of key documents are also
available for review at the Lewis and Clark Public Library, located at 120 S. Last Chance
Gulch in Helena, Montana.
Assessment of the Site
The response action selected in this ROD is necessary to protect public health or welfare
or the environment from actual or threatened releases of hazardous substances, pollutants,
or contaminants from the site, which may present an imminent and substantial endangerment
to public health or welfare.
Description of Selected Remedy
This ROD encompasses all aspects of the site, including all removal and remedial response
actions. The site includes contaminated waste rock and tailings, acid mine drainage (AMD),
groundwater, surface water, stream sediments, yard soils at permanent residences and
occasional-use recreational cabins, roadway materials, and water supply. This is the only
ROD that EPA intends to issue for the site.
The selected remedy is Alternative 5, as modified, for mine wastes and Alternative D for
the Rimini community water system, as described in the proposed plan, with the exception
that all accessible contaminated yard soils and roadway materials in Rimini (rather than
only the uppermost 18 inches) will be excavated and removed to the Luttrell repository.
The selected remedy also provides for the design and construction of a small community
wastewater system, if necessary to replace existing individual septic systems that may be
damaged during the removal of contaminated yard soils in Rimini. The selected remedy
contains elements that address each of the contaminated media at the site. The remedy was
selected after the development, screening, and evaluation of potential remedial
alternatives in the FS, and after review and consideration of public and agency comments
received on both a preliminary draft proposed plan and the final proposed plan.
-------
The selected remedy will consist of the following elements:
Waste Rock and Tailings
• Excavate and dispose in the Luttrell repository contaminated materials from 70 high
priority mine sites. No action would be taken at the remaining 80 lower priority
mine sites. Backfill the excavated areas with clean soils to appropriate slope
contours and revegetate.
Acid Mine Drainage
• Cap and regrade collapsed shafts/adits and construct drainage features to prevent or
reduce storm water and snowmelt from entering mine workings and contributing to AMD.
Conduct a four-phase program to develop and implement cost-effective control
measures to eliminate metals loading from existing mine adit discharges. The
program, conducted by EPA in consultation with DEQ (and the USFS, for sites on
national forest lands), will include (1) initial design investigations to map mine
site features and identify sites where source control and flow reduction technigues
could be potentially successful; (2) additional detailed studies and pilot tests of
flow segregation, grouting, or other source control/ flow reduction technigues; (3)
full scale flow reduction actions at sites where they are deemed appropriate; and
(4) evaluation, design, and construction of AMD treatment facilities, if necessary
to meet state ambient water guality standards.
• EPA anticipates that treatment for many of the AMD sites, which are remotely located
and have low flow rates and loadings, will consist of low cost, low maintenance
biological treatment systems (probably utilizing enhanced sulfate- reducing
bacteria, oxidation, and constructed wetlands, with additional treatment polishing
components) or other in-situ treatment systems.
Groundwater
• Source control actions for waste rock and tailings and AMD are expected to reduce
groundwater contaminant levels. Implement institutional controls to prevent the use
of new drinking water wells where contaminated aguifers exist.
Surface Water
• Augment stream flow in Tenmile Creek during low-flow periods by constructing
improvements to Chessman Reservoir and the Red Mountain flume to provide for
additional water storage in the reservoir and/or implementing other water management
actions in the upper Tenmile Creek watershed. The additional stored water would be
available to the City of Helena to offset water allowed to bypass the City of Helena
Tenmile Creek intake structure to augment stream flow in and below Rimini during the
late summer and early fall low-flow periods. Flow augmentation would complement
EPA's cleanup activities and improve Tenmile Creek water guality to levels that
approach established performance standards.
• Source control actions for waste rock and tailings and AMD, augmented stream flows
during low-flow periods, and natural attenuation of contaminants in surface water
are expected to achieve surface water remedial action goals within a reasonable
time.
Stream Sediments
• Monitor water guality and sediment guality in Tenmile Creek after waste rock/
tailings and AMD cleanup actions are complete. After additional monitoring and
evaluation, if sediments in specific stream reaches are determined responsible for
unacceptable loading to surface water, then excavate those sediments, with disposal
at the Luttrell repository.
-------
Contaminated Yard Soils
• Excavate, transport, and dispose of contaminated yard soils from residences and
occasional-use recreational cabins. Contaminated soils will be disposed in the
Luttrell repository. Backfill with clean soils and replace yard vegetation, fences,
and other features to pre-removal conditions.
• The remedy includes a contingency for EPA to design and construct a small community
wastewater collection and treatment system, if necessary, to replace individual
septic systems that may be damaged or removed during the removal of contaminated
yard soils.
Contaminated Roadway Materials
• Excavate, transport, and dispose of contaminated roadway materials underlying Rimini
Road. Approximately 5,000 feet of roadway through the community of Rimini will be
addressed. Backfill the road with clean fill and appropriate road subbase and
surface gravel.
Pi mini Water Supply
• Build a new community water system for Rimini residents. The source of water for the
community system will be new deep wells installed near Rimini. The system will
include water storage and distribution and have the capacity to serve approximately
50 residences.
Protectiveness of Selected Remedy
The selected remedy is protective of human health and the environment through the
following:
Waste Rock and Tailings
Removal and disposal of waste rock and tailings from high priority mine sites in a secure
repository will protect human health and the environment through the prevention of direct
contact with those contaminants at the site. It will effectively isolate the most
significant waste piles at the site by placing them in a lined regional repository with
effective leachate control and monitoring. Waste rock piles will be left in place only at
those sites exhibiting limited human access, thereby preventing or minimizing the
potential for human exposure, and limited potential for directly impacting surface water
or the aguatic ecosystem.
Acid Mine Drainage
The combination of reducing surface water inflow to mine workings and implementing a
four-phased approach to reduce metals loading from AMD to surface water, including the
treatment of AMD waters prior to the waters entering the watershed streams, will ensure
that impacts from AMD on the source water for the City of Helena potable water system and
on the aguatic ecosystem are reduced seguentially in a cost-effective manner. Contaminant
loadings to surface water will be reduced in the near term by reducing the flows
discharging from mine adits and in the long term by constructing appropriate treatment
facilities to remove contaminants from residual mine adit discharge flows that cannot be
eliminated.
Groundwater
The selected remedy will not directly remediate the groundwater underlying the community
of Rimini or in other areas. Protectiveness will be achieved in the Rimini area through
the construction of a reliable community water system drawing water from deep wells
unimpacted by mining-related contamination. The community water system will replace
current residential wells that supply contaminated groundwater to individual residences.
Additionally, institutional controls, probably a controlled groundwater area in parts of
-------
the site known to have contaminated groundwater, will ensure that full-year and part-time
residents outside of the community water system service area do not use wells drawing
contaminated groundwater for drinking water purposes.
Surface Water
The selected remedy will not directly remediate surface water. Protectiveness of human
health and the environment will be achieved by the removal of near-stream waste rock and
tailings contaminant sources to eliminate leaching and erosion of contaminants into
surface water, reduction of AMD loading of contaminants into surface water, and augmenting
Tenmile Creek flows during low flow periods when water guality is significantly degraded.
These actions will improve the guality of water currently supplied to the City of Helena
water system, as well as water left in the stream and used by the aguatic ecosystem. The
selected remedy would also improve stream flow suitable for fish in Tenmile Creek below
Rimini during low flow periods of late summer and early fall.
Negotiations are progressing whereby the City of Helena could apply its first priority
water rights to waters stored and released to Tenmile Creek, ensuring that the enhanced
flow would pass downstream to the lower reaches of Tenmile Creek. In addition, the city is
also considering the implementation of a sixth diversion from Tenmile Creek (near Walker
Creek) to allow for the release of additional water during the late fall and winter months
to complement EPA's remedy.
The City of Helena has indicated it will support EPA's long-term remedy by agreeing to
own, operate, and maintain the Banner Creek diversion and the Chessman Reservoir as
necessary to augment stream flow. Actual releases of stored water for flow augmentation
could be from the city-owned Scott Reservoir.
The USFS and the City of Helena are striving to accomplish land exchanges under USFS
removal authorities that would facilitate EPA's CERCLA action. USFS may exchange ownership
and/or control of the Chessman Reservoir and portions of the Banner Creek diversion for
city-owned inholdings that could include the high value Travis wetlands and the impaired
Banner Creek wetlands. Logically, EPA's mitigation for wetlands inundated by the expanded
Chessman Reservoir could involve the impaired Banner Creek wetlands.
Stream Sediments
The selected remedy provides for long-term monitoring of sediment guality, followed by
refinements in cleanup activities as necessary. The remedy will not immediately remove
stream sediments that may be impacting surface water guality and aguatic organisms.
However, source control actions removing near-stream waste rock and tailings and
addressing AMD are expected to significantly reduce loadings to Tenmile Creek and its
tributaries and improve sediment guality. The selected remedy provides for the monitoring
of contaminant concentrations in stream sediments and surface water in the Rimini area to
determine if stream sediments are a limiting factor in attaining water guality goals. If
sediments are determined to be a significant source of continuing metals loading to the
stream, then the selected remedy reguires that those sediments be removed.
Contaminated Yard Soils
The selected remedy will meet protectiveness standards for contaminated yard soils at
residences and occasional-use recreational cabins by removing and disposing in the
Luttrell repository the soil in those yards, or portions of yards, found to exceed EPA's
site- specific target excavation concentration levels for arsenic and lead. The yards will
be backfilled with clean soil and revegetated. Institutional controls, such as deed
notices or a building permit process, will be put in place for those locations of the site
where contaminated waste rock/tailings or yard soils are inaccessible and cannot be
removed. Property owners conducting future excavation in contaminant- impacted areas will
be reguired to manage the waste materials in accordance with county- reguired controls,
with disposal in the Luttrell repository or another appropriate disposal facility.
Contaminated Roadway Materials
Potential direct contact exposure to contaminated roadway materials in the community of
-------
Rimini will be addressed by excavating, transporting, and disposing of the contaminated
materials at the Luttrell repository. The road will be replaced to approximate existing
grade and condition with clean fill and road base and surface materials.
Pi mini Water Supply
Protectiveness will be achieved in the Rimini area through the construction of a reliable
community water system drawing water from deep wells unimpacted by mining-related
contamination and implementation of institutional controls to prevent the consumption of
contaminated groundwater. The community water system will replace current residential
wells that supply contaminated groundwater to individual residences; however, the existing
wells may continue to be used for irrigation purposes.
Statutory Determinations
The selected remedy attains the mandates of CERCLA Section 121 and, to the extent
practical, the NCP. Specifically, the selected remedy is protective of human health and
the environment, complies with federal and state reguirements that are applicable or
relevant and appropriate to the remedial action (unless a waiver is ultimately determined
necessary and appropriate), is cost effective, and utilizes permanent solutions and
alternative treatment technologies to the maximum extent practicable. This remedy also
satisfies the statutory preference for treatment as a principal element of the remedy
(i.e., reduces the toxicity, mobility, or volume of hazardous substances, pollutants, or
contaminants as a principal element through treatment). Because this remedy will result in
hazardous substances, pollutants, or contaminants remaining on site at concentrations
greater than those that would be protective for unlimited use and unrestricted exposure,
reviews will be conducted five years after initiation of remedial action and every five
years thereafter to ensure that the remedy continues to provide adeguate protection of
human health and the environment. This remedy is acceptable to the State of Montana, Lewis
and Clark County, the City of Helena, and residents of the Rimini community.
-------
Data Certification Checklist
The following information is included in the Decision Summary section of this ROD.
Additional information can be found in the administrative record file for this site.
• Chemicals of concern (COG) and their respective concentrations
• Baseline risk presented by the COCs
• Cleanup levels established for COCs and the basis for these levels
• Documentation of how the remedy uses treatment to address source materials
constituting principal threats
• Current and reasonably anticipated future land use assumptions and current and
potential future beneficial uses of groundwater used in the baseline risk assessment
and ROD
• Potential land and groundwater use that will be available at the site as a result of
the selected remedy
• Estimated capital, annual operation and maintenance, and total present worth costs,
discount rate, and the number of years over which the remedy cost estimates are
projected
• Key factors that led to selecting the remedy
Max H. Dodson Date
Assistant Regional Administrator
Office of Eeosystems Protection and Remediation
U- S> Environmental Protection Agency, Region VIII
n P. Sensibaugh ~O /Date
Director
Montana Department of Environmental Quality
-------
Decision Summary
This section of the Record of Decision (ROD) provides an overview of the site
characteristics, alternatives evaluated, and the analysis of these options. This section
also identifies the Selected Remedy and explains how this remedy fulfills statutory and
regulatory requirements.
-------
Contents
Preface
Declaration
Decision Summary
Tables iv
Figures vi
Acronyms vii
Section 1 - Site Name, Location, and Description 1-1
Section 2 - Site History and Enforcement Activities 2-1
Section 3 - Community Participation 3-1
Section 4 - Scope and Role of Operable Unit 4-1
Section 5 - Summary of Site Characteristics 5-1
5 .1 Site Overview 5-1
5.2 Site Conceptual Model 5-1
5.3 Known and Suspected Sources of Contamination 5-3
5.4 Investigation and Sampling Approach 5-4
5.4.1 Waste Source Areas 5-5
5.4.2 Surface Water 5-5
5.4.3 Sediment 5-5
5.4.4 Groundwater 5-6
5.4.5 Residential Yards and Roadway Areas 5-6
5.5 Types of Contamination and Affected Media 5-6
5.5.1 Mine Site Waste Rock and Tailings 5-8
5.5.2 Acid Mine and Acid Rock Drainage 5-8
5.5.3 Surface Water Quality and Contaminant Loading 5-8
5.5.4 Stream Sediment Quality and Potential Impacts to Surface Water . 5-12
5.5.5 Groundwater Quality 5-13
5.5.6 Residential Yards 5-13
5.5.7 Contaminated Roadways 5-14
5.6 Contamination Location and Routes of Migration 5-14
5.6.1 Lateral and Vertical Extent of Contamination 5-14
5.6.2 Contamination Migration 5-15
5.6.3 Exposure Pathways 5-16
Section 6 - Current and Potential Future Land and Water Use 6-1
6.1 Land Use 6-1
6.2 Water Use 6-2
Section 7 - Summary of Site Risks 7-1
7.1 Human Health Risks 7-1
7.1.1 Media and Chemicals of Concern 7-1
7.1.2 Exposure Assessment 7-1
7.1.3 Toxicity Assessment 7-3
7.1.4 Risk Characterization 7-6
7.1.5 Human Health Risk Conclusions 7-14
7.2 Ecological Risks 7-15
7.2.1 Chemicals of Concern 7-15
7.2.2 Exposure Assessment 7-16
-------
7.2.3 Ecological Effects Assessment 7-18
7.2.4 Ecological Risk Characterization 7-23
7.2.5 Ecological Risk Assessment Conclusions 7-27
7.3 Risk- Based, Preliminary Remediation Goals 7-28
7.4 Basis of Action 7-29
Section 8 - Remedial Action Objectives 8-1
Section 9 - Description of Alternatives 9-1
9.1 Media-Specific Alternatives 9-1
9.1.1 Waste Rock and Tailings 9-1
9.1.2 Acid Mine Drainage 9-23
9.1.3 Contaminated Surface Water 9-25
9.1.4 Contaminated Stream Sediments 9-25
9.1.5 Contaminated Groundwater 9-25
9.1.6 Contaminated Yards 9-26
9.1.7 Contaminated Roadway Materials 9-26
9.2 Development and Evaluation of Sitewide Remedial Alternatives 9-27
9.2.1 Description of Comprehensive Alternatives for Mine Site
Remediation 9-27
9.2.2 Description of Rimini Water Supply Alternatives 9-32
Section 10 - Summary of Comparative Analysis of Alternatives 10-1
10.1 NCP Evaluation and Comparison Criteria 10-1
10.1.1 Threshold Criteria 10-1
10.1.2 Primary Balancing Criteria 10-2
10.1.3 Modifying Criteria 10-2
10.2 Evaluating the Alternatives with the NCP Criteria 10-2
10.2.1 Comprehensive Sitewide Mine Site Alternatives 10-2
10.2.2 Rimini Water Supply Alternatives 10-9
Section 11 - Principal Threat Wastes 11-1
Section 12 - Selected Remedy 12-1
12.1 Rationale for Selected Remedy 12-1
12.2 Description of Selected Remedy 12-2
12.3 Estimated Remedy Costs 12-6
12.4 Operations and Maintenance Reguirements 12-17
12.5 Expected Outcome of the Selected Remedy 12-20
12.6 Performance Standards 12-33
12.7 Remedy Contingencies 12-35
Section 13 - Statutory Determinations 13-1
13.1 Protection of Human Health and the Environment 13-1
13.2 Compliance with ARARs 13-2
13.3 Cost Effectiveness 13-4
13.4 Utilization of Permanent Solutions and Alternative Treatment Technologies (or
Resource Recovery Technologies) to the Maximum Extent Possible 13-4
13.5 Preference For Treatment as a Principal Element 13-7
13.6 Five-Year Review Reguirements 13-7
Section 14 - Documentation of Significant Changes 14-1
Section 15 - References 15-1
Responsiveness Summary
Appendices
Appendix A - Identification and Description of Applicable or Relevant and
Appropriate
-------
Requirements
Appendix B - Mine Site Scoring and Capital Costs for Selected Remedy
Appendix C - Responses to Comments
Appendix D - Basin Creek Mine Reclamation Responsibilities
Tables
Table 5-1 Summary of Contamination and Affected Media
Table 5-2 Representative Baseflow Water Quality in Tenmile Creek and Key Tributaries
Table 5-3 Ranked Top 25 Mine Site Sources of Loading to Surface Water
Table 7-1 Summary of Chemicals of Concern for Human Health
Table 7-2 Exposure Pathways Evaluated for Residents, Workers, and Recreationists
Table 7-3 Summary Statistics for Chemicals of Concern for Human Health
Table 7-4 Cancer Slope Factors for Chemicals of Concern
Table 7-5 Reference Doses for Chemicals of Concern
Table 7-6 Summary of Site- Related Lifetime Risk Estimates - Residents
Table 7-7 Summary of Site- Related Lifetime Risk Estimates - Workers
Table 7-8 Summary of Site- Related Lifetime Risk Estimates - Recreationists
Table 7-9 Summary of Chemicals of Concern for Ecological Risk
Table 7-10 Summary of Statistics for Chemicals of Concern for Ecological Risk
Table 7-11 Toxicity Reference Values for Surface Water Chemicals of Concern
Table 7-12 Toxicity Reference Values for Sediment Chemicals of Concern
Table 7-13 Toxicity Reference Values for Surface Soil Chemicals of Concern
Table 7-14 Toxicity Reference Values for Piscivorous and Insectivorous Birds and
Piscivorous Mammals (Major Surface Water Chemicals of Concern)
Table 7-15 Hazard Quotients for Chemicals of Concern in Surface Water, Sediment, and Soil
Table 7-16 Estimated Risks (Hazard Quotients) for Representative Birds and Mammals
Table 7-17 Preliminary Remediation Goals for Potential Exposure Through Ingestion of
Solid Media (Waste Rock, Tailings, and Surface Soil)
Table 9-1 Mine Site Category and Adit Discharge Summary
Table 9-2 Summary Description of Sitewide Alternatives
Table 9-3 Summary Description of Rimini Water Supply Alternatives
Table 10-1 Comparative Analysis of Sitewide Alternatives
Table 10-2 Comparative Analysis of Rimini Water Supply Alternatives
Table 12-1 Summary of Estimated Capital Costs for Sitewide Selected Remedy
Table 12-2 Summary of Estimated Post- Construction Costs for Sitewide Selected Remedy
Table 12-3 30-Year Present Value Analysis for Sitewide Selected Remedy
Table 12-4 Summary of Estimated Capital and Post- Construction Costs for Rimini Community
Water System Selected Remedy
Table 12-5 30-Year Present Value Analysis for Rimini Community Water System Selected
Remedy
Table 12-6 Summary of Estimated Capital and Post-Construction Costs for Rimini Community
Wastewater System Contingency Remedy
Table 12-7 30-Year Present Value Analysis for Rimini Community Wastewater System
Contingency Remedy
Table 12-8 Soil Cleanup Levels and Initial Excavation Criteria
Table 12-9 Cleanup Levels for Key Chemicals of Concern in Surface Water and Groundwater
Table 13-1 Cost-Effectiveness Evaluation for Sitewide Alternatives
Table 13-2 Cost-Effectiveness Evaluation for Rimini Community Water System Alternatives
-------
Figures
Figure 1-1 Site Location
Figure 1-2 Subareas and Helena Water System Features
Figure 5-1 Site Conceptual Exposure Model
Figure 7-1 Effects Concentrations/Level of Protection - Dissolved Cadmium in Surface
Water
Figure 7-2 Effects Concentrations/Level of Protection - Dissolved Copper in Surface Water
Figure 7-3 Effects Concentrations/Level of Protection for Dissolved Zinc in Surface Water
Figure 9-1 Upper Tenmile Creek/Monitor Creek Subarea
Figure 9-2 Banner Creek/Ruby Creek Subarea
Figure 9-3a Tenmile Creek Near Rimini Subarea
Figure 9-3b Tenmile Creek Near Rimini Subarea Detail
Figure 9-4 Beaver Creek Subarea
Figure 9-5 Minnehaha Creek Subarea
Figure 9-6 Bear Gulch/Walker Creek Subarea
Figure 9-7 Tenmile Creek Mainstem Subarea
Figure 12-1 Rimini Community Water System Selected Remedy Costs Estimated annual O&M Costs
and Revenues
Figure 12-2 Arsenic in Tenmile Creek Measured vs Modeled Preferred Alternative
Figure 12-3 Cadmium in Tenmile Creek Measured vs Modeled Preferred Alternative
Figure 12-4 Copper in Tenmile Creek Measured vs Modeled Preferred Alternative
Figure 12-5 Lead in Tenmile Creek Measured vs Modeled Preferred Alternative
Figure 12-6 Zinc in Tenmile Creek Measured vs Modeled Preferred Alternative
-------
Acronyms
aka also known as
AMD acid mine drainage
amsl above mean sea level
ARARs applicable or relevant and appropriate requirements
ARD acid rock drainage
ATSDR The Agency for Toxic Substances and Disease Registry
AWQC ambient water quality criteria
BCM Basin Creek Mine
BLM Bureau of Land Management
BMP best management practice
GDI chronic daily intake
COM CDM Federal Programs Corporation
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
cfs Cubic Feet per Second
COG chemicals of concern
CSF cancer slope factor
CTE central tendency exposure
DEQ Montana Department of Environmental Quality
DFWP Montana Department of Fish Wildlife and Parks
DNRC Montana Department of Natural Resources and Conservation
DSL Montana Department of State Lands
EA environmental assessment
ERA ecological risk assessment
EPCs exposure point concentrations
EPA U. S. Environmental Protection Agency
FS feasibility study
gpm gallons per minute
HHRA human health risk assessment
HI hazard index
HQ hazard quotient
HRS hazard ranking system
IRIS integrated risk information system
IEUBK Integrated Exposure Uptake Biokinetic
km kilometer
LC50 lethal concentrations to 50 percent
MCL maximum contaminant level
mgd million gallons per day
mg/kg milligrams per kilogram
mg/L milligrams per liter
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NPL National Priorities List
OSWER Office of Solid Waste and Emergency Response
OU operable unit
O&M operations and maintenance
POU point-of-use
PRG preliminary remediation goal
PRP potentially responsible party
RAO remedial action objectives
RBT rainbow trout
RfD reference dose
RI remedial investigation
RME reasonable maximum exposure
ROD Record of Decision
site Upper Tenmile Creek Mining Area National Priorities List Site
TMDL total maximum daily load
TRVs toxicity reference values
UCL upper confidence limit
USFS U. S. Forest Service
-------
ug/dL micrograms per deciliter
ug/L micrograms per liter
USC United States Code
USFWS U. S. Fish and Wildlife Service
WUA weighted usable area
-------
Section 1
Site Name, Location, and Description
Upper Tenmile Creek Mining Area Site
Lewis and Clark County, Montana
CERCLIS Number MTSFN7578012
The Upper Tenmile Creek Mining Area Site (site) is located primarily within Lewis and
Clark County, southwest of Helena, Montana (Figure 1-1). The site extends from U.S.
Highway 12 south to the drainage divide adjoining the Basin Creek, Cataract Creek, and
Telegraph Creek watersheds. To the west, the site is bounded by the Continental Divide.
The Tenmile Creek basin is the primary watershed in the site. The site covers
approximately 53 sguare miles and is located primarily in Township 8 North, Range 5 West
(T8N R5W) and T9N R5W in Lewis and Clark County. The easternmost portions of T8N R6W and
T9N R6W and the southernmost portion of T10N R5W are also located in the site.
The U.S. Environmental Protection Agency (EPA) is the lead agency for the site and the
Montana Department of Environmental Quality (DEQ) and the U.S. Forest Service (USFS) are
support agencies. The City of Helena and Lewis and Clark County have significant interests
in the site, since the upper Tenmile Creek watershed is the main source of potable water
for the City of Helena. The primary source of funding for cleaning up for the site will be
the Superfund trust fund. Before remedial action utilizing the Superfund trust fund can
begin, CERCLA reguires that a state provide assurances to EPA that the state will be
responsible for financing 10 percent of the remedy construction and 100 percent of the
remedy operation and maintenance (O&M). The state's assurances are to be provided in
Superfund state contracts executed by the state and EPA prior to the start of each
construction season for the work to be performed that season. Any cleanup actions,
including both construction and O&M, taken on public land managed by the USFS would be
financed by the USFS.
The headwaters of Tenmile Creek are about 6 miles upstream of the community of Rimini,
which is located in the approximate center of the site. From its headwaters, Tenmile Creek
flows for 28 miles before entering Lake Helena. Only the uppermost 13 miles are located in
the site. The site lies within the Northern Rocky Mountain physiographic province, which
is characterized by a succession of distinct mountains and valleys. The upper Tenmile
Creek drainage basin is mountainous with high and sharp relief. Red Mountain, southeast of
the community of Rimini, rises to an elevation of 8,150 feet above mean sea level (amsl)
and represents the highest point in the watershed. Tenmile Creek originates at the
Continental Divide at an elevation of approximately 7,200 feet amsl and drops to 4,380
feet amsl at the northern boundary of the site near the confluence with Sweeney Creek. Lee
Mountain is directly west of Red Mountain and rises above the valley to an elevation of
7,064 feet amsl.
-------
TENNILE WATER
TREATMENT PLANT
D> Helena
ButteQ
COMMUNITY
OF fUMINI
; Upper Tenrnle Creek i
Area Site i
Figure 1-1
Site Location
Upper Tenmlle Creek Mining Area Site
Upper Termite Creek Mining Area Site
in Creek Mine Area
LUTTRELL
REPOSITORY
0 1
Teira Tech EM Inc. COM
The City of Helena has relied upon the upper Tenmile Creek watershed as a source of
potable water for over 100 years. A thorough understanding of the Helena water supply
system is necessary in developing a cleanup plan for this site. Stream reaches below the
city water system diversions often have very low flows, which exacerbate the water guality
degradation caused by the mine wastes at the site. The city possesses senior water rights
totaling approximately 8.9 million gallons per day (mgd). Natural stream flow in the
Tenmile Creek watershed is less than Helena's allowable water right for much of the year.
To increase the guantity of water from the Tenmile Creek watershed available for use by
the city, two water storage reservoirs have been constructed in the basin. Chessman
Reservoir, located in the headwaters of Beaver Creek, has a capacity of 550 million
gallons (1,688 acre-feet). Scott Reservoir, located in the headwaters of Ruby Creek, has a
capacity of 194 million gallons (595 acre-feet).
By court decree, only surplus waters flowing in Banner Creek and Ruby Creek prior to the
commencement of irrigation season in the lower watershed downstream of the Tenmile Water
Treatment Plant can be diverted into the two reservoirs (Chessman Reservoir is partially
filled by an inter-drainage diversion from Banner Creek using the Red Mountain flume).
Raw water is supplied to the Tenmile Water Treatment Plant via a gravity pipeline that
collects water from an intake structure located on Tenmile Creek just above the community
of Rimini and from intake structures located on Beaver Creek, Minnehaha Creek, Moose
Creek, and Walker Gulch just above their confluences with Tenmile Creek. Features of the
Helena Tenmile Creek water supply system are shown on Figure 1-2.
-------
To facilitate the evaluation of mine site and tributary contaminant loadings during the
remedial investigation (RI) and feasibility study (FS) , the site has been divided into
seven subareas, including two subareas that subdivide the upper Tenmile Creek mainstem and
five subareas that encompass the primary tributaries to the mainstem. These seven subareas
are: (1) Tenmile Creek Near Rimini (mainstem from the Ruby Creek confluence to the
Minnehaha Creek confluence), (2) Tenmile Creek Mainstem (mainstem from the Minnehaha Creek
confluence downstream to Helena's Tenmile Water Treatment Plant), (3) Upper Tenmile Creek/
Monitor Creek, (4) Banner Creek/Ruby Creek, (5) Beaver Creek, (6) Minnehaha Creek, and (7)
Bear Gulch/ Walker Creek. The seven subareas are shown in Figure 1-2.
Mining within the Upper Tenmile Creek watershed has resulted in uncontrolled releases of
metal contaminants to local streams from waste rock, tailings (waste material from
processing of mineral ore), and contaminated mine discharge water. The major threat posed
by the abandoned mines is the release of potentially harmful concentrations of arsenic,
copper, lead, zinc, and other metals from mine wastes. These mines and their associated
waste piles and tailings contribute to the contamination of surface water, groundwater,
and stream sediments throughout the drainage basin of upper Tenmile Creek and its
tributaries. There have been documented catastrophic releases of mining wastes during
periods of intense thunderstorms or other mass failures of waste material piles.
Concentrations of arsenic and metals in site media often exceed risk-based protectiveness
criteria and therefore pose a current and potential threat to human health and the
environment. The upper Tenmile Creek watershed supplies about 70 to 80 percent of the City
of Helena's drinking water. Approximately 13 residences in Rimini receive untreated water
directly from Tenmile Creek.
Low flow rates in Tenmile Creek are also of concern. RI data indicate that human health
and aguatic life water guality criteria are exceeded most often during low flow. Low flow
occurs primarily during late summer when the public's demand for water increases. During
this time, both the guality and the guantity of water in Tenmile Creek are insufficient to
maintain healthy fish populations in all stream reaches.
-------
LEOEND
A City of Helena Water Intakes
^~ Flume
•I Water Storage Reservoirs
•I Tenmlle Water Treatment Plant
!~~l Subarea Boundary
^3 TenmSte Creek NPL Boundary
I I Wetland Areas
0,5 0 0.5 1 1,5 Miles
CIS by Ed MMftj l'De/C2
Figure 1-2
Su bare as and
Helena Water System Features
Upper Tenmlle Creek Mining Area Site
Tetra Tech EM Inc. CDM
-------
Section 2
Site History and Enforcement Activities
The site includes 150 abandoned or inactive mine sites within or near the historic Rimini
Mining District in the upper Tenmile Creek watershed. Most historic mining activity in the
watershed took place within the Rimini Mining District and included hard rock mining for
gold, lead, zinc, and copper. Active hard rock mining began in the 1870s and continued
through the 1930s. Limited intermittent mining activities were conducted during and after
World War II. The last active commercial mining in the Rimini Mining District ended in
1953. The site also includes the properties of the defunct Basin Creek Mine (BCM), an open
pit gold mine that operated under a DEQ permit until the mid- 1990s. The BCM is being
reclaimed by the bankruptcy trustee for the former operator of the mine using money from a
reclamation bond forfeited by the operator to DEQ upon bankruptcy. Since the Luttrell Pit
and various haul roads at the BCM are being used to facilitate the EPA remedies for this
site and the Basin Mining Area site, EPA will manage final reclamation for those parts of
the BCM properties. A detailed breakdown of EPA's reclamation responsibilities at the BCM
is presented in Appendix D. EPA will not be responsible for BCM water discharge outfalls
from Leach Pad 1, Leach Pad 3, or the SSMS spring.
EPA, USFS, and DEQ (formerly the Department of State Lands [DSL]) have been involved in
evaluating and conducting abandoned mine reclamation and cleanups at the site since the
late 1980s. In October 1999, the Upper Tenmile Creek Mining Area Site was added to EPA's
National Priorities List (NPL) for Superfund cleanup.
The major investigations and activities conducted at the site since the 1980s include:
1987-1990: DSL removed waste rock and tailings materials from the following abandoned
mines and disposed of the materials at an active mine in Jefferson County:
• Avon Mill
Ballou
• Bunker Hill (also known as [aka] Daniel Stanton)
• Evergreen Reclamation (aka Lower Evergreen)
• Justice
Kelly Mill
• Lee Mountain
Little Lily
• Little Sampson
• Lower Tenmile Mill (aka Engstrom Millsite)
• Susie
At each of the mines, DSL recontoured, stabilized in place, covered, and revegetated
residual mine wastes. DSL was not able to collect or treat mine adit discharges.
1993-1994: DSL conducted thorough investigations of 17 historic mining complexes within
the upper Tenmile Creek watershed. The following sites were inventoried:
• Armstrong
Bear Gulch
• Beatrice
Bunker Hill (aka Tenmile)
• Lower Tenmile Mill
• Monitor Creek Tailings
• Monte Cristo
• National Extension
• Peerless Jenny
• Peter
• Queensbury
• Red Mountain
-------
• Red Water
SE SE S13
• Susie (aka Valley Forge/Susie)
• Upper Valley Forge
• Woodrow Wilson
DSL issued two reports summarizing waste material and water quality analytical data, site
mapping, and reconnaissance information for each site inventoried.
1995: EPA conducted a removal of waste materials in a residential area near the Lower
Tenmile Mill site.
October and November 1997: EPA conducted a removal action at the Red Water Mine.
Approximately 5,700 cubic yards of waste rock were excavated and moved to the northern end
of the mine site, and 1,800 cubic yards of contaminated material from the wooded area
north of the waste rock pile and from an area adjacent to the on-site residence were
placed on top of the waste rock. A bench was placed on the existing original surface;
large rocks (rip rap) were placed on the bench to add support. No clay liner was placed on
the bench or the original slope. The repository was covered with clean fill material and
revegetated. Drainage controls to prevent run on of storm water and snowmelt were also
constructed.
April 7, 1998: The Lewis and Clark County Water Protection District requested assistance
from DEQ and EPA in undertaking a cleanup at the Bunker Hill Mine. On two occasions,
hydraulic pressure built up behind the collapsed mine adit and "blew out" the collapsed
materials, eroding both mine waste and previous reclamation cover materials and causing a
mass loading problem in the Tenmile Creek. Although water quality samples were not
collected during these events, contaminant concentrations in sediments deposited
downstream indicate that the quality of Helena's water was threatened.
Fall 1998: The Montana Department of Fish, Wildlife, and Parks (DFWP) collected brook
trout fish tissue samples from Tenmile Creek, which showed elevated levels of arsenic.
April 28, 1999: EPA issued requests for access for sampling, characterization, and
response activities at properties in the Upper Tenmile Creek watershed. About 20 letters
were sent to property owners requesting access.
May 10, 1999: A Hazard Ranking System (HRS) scoring package was prepared for the site to
evaluate potential relative risks to public health and the environment from releases or
threatened releases of hazardous substances. The site received an HRS Site Score of 50 (a
score above 28.5 makes a site eligible for listing on the NPL).
June 7, 1999: EPA prepared an Action Memorandum to initiate a time-critical removal action
at the Red Mountain and Bunker Hill/Tenmile mines, and to request exemptions from the $2
million and 12-month statutory limits.
June 24, 1999: DEQ, pursuant to the Montana Environmental Policy Act, prepared an
Environmental Assessment (EA) describing a proposed change in land use at the currently
permitted BCM to provide for use of the Luttrell Pit as a mine waste repository. EPA, in
consultation with USFS and DEQ, established the Luttrell repository, located at the
bankrupt Basin Creek Mine (BCM), as the repository for mine wastes excavated from the
Upper Tenmile Creek Mining Area and Basin Mining Area Superfund sites. Wastes are
deposited in accordance with an agreement signed by EPA, USFS, Bureau of Land Management
(BLM), the owner of BCM, and Lewis and Clark County for use of the Luttrell repository.
The repository will also be available to receive similar mine wastes from EPA, USFS, BLM,
or State of Montana sites in other nearby watersheds.
July 22, 1999: EPA proposed the Upper Tenmile Creek Mining Area Site for listing on the
NPL.
-------
Summer 1999: EPA's Superfund Removal Program conducted mine waste removals at the Red
Mountain and Bunker Hill/Tenmile mine sites. About 50,000 cubic yards of waste rock were
removed from the Red Mountain Mine and deposited in the Luttrell repository.
October 22, 1999: The Upper Tenmile Creek Mining Area Site was placed on the NPL.
Summer 2000: At the reguest of the Upper Tenmile Watershed Steering Committee, Lewis and
Clark County Water Quality Protection District, and the State of Montana, EPA conducted
additional waste removal actions at the Peerless Jenny/King complex, Susie, and Red
Mountain sites. USFS conducted three mine site waste removals in the Minnehaha Creek
drainage: the Armstrong, Beatrice, and Justice sites. All wastes removed from mine sites
by EPA and USFS during 2000 were transported to the Luttrell repository for disposal.
2000-2001: EPA conducted an RI/FS to investigate site contamination and evaluate
remediation alternatives for the site. Environmental samples were collected and analyzed
in 2000. The draft RI report was issued in February 2001 and draft FS report in March
2001. The final ecological risk assessment (ERA) was issued in April 2001 and the final
human health risk assessment (HHRA) in October 2001. An addendum to the RI/FS, responding
to comments received on the draft RI and FS documents, was issued in December 2001.
January 2001: EPA conducted additional sampling of tap water from residential wells at the
site and provided replacement bottled water for site residents whose well water exceeded
maximum contaminant levels (MCLs) for drinking water. EPA recognized the need for interim
potable water supply for Rimini prior to the final remedial action and installed
individual reverse osmosis treatment systems in homes with contaminated well water.
Summer 2001: EPA conducted additional waste removal actions at the Bunker Hill and
Queensbury sites and completed surface reclamation work at the Red Mountain, Bunker Hill,
Susie, Peerless Jenny/King, and Queensbury sites. USFS conducted a mine site waste removal
at the Upper Valley Forge site. All wastes removed from mine sites by EPA and USFS during
2001 were transported to the Luttrell repository for disposal.
July 2001: EPA released a preliminary draft proposed plan for public review and comment.
October 22, 2001: The proposed plan for the site was issued for public comment.
Significant changes were made to the proposed plan in response to comments provided on the
preliminary draft proposed plan. The 30-day public comment period extended from October
22, 2001 to November 21, 2001.
No potentially responsible party (PRP) has been identified that is deemed to have the
financial resources or technical capability to conduct a response action. PRP searches
have been conducted with respect to the following mining sites:
• Tenmile Creek residential time critical removal
• Redwater mine
• Susie mine
• Red Mountain mine
• Bunker Hill/Tenmile mines
• Peerless Jenny/King mining complex
Information reviewed for each of these mine sites corroborated similar findings by DEQ,
who conducted previous cleanup actions at a number of mine sites addressed in this ROD,
and USFS, who conducted cleanups at the Beatrice, Justice, Armstrong and Upper Valley
Forge mine sites. Final decisions on pursuing cost recovery from certain parties have not
been made. EPA will continue to evaluate the potential to identify responsible parties on
a yearly basis prior to conducting cleanups at the individual mine sites.
-------
Section 3
Community Participation
Public participation in the remedy selection process is required by CERCLA Sections 113
and 117 and NCP Section 300.430(f)(3). These actions require that before adoption of any
plan for remedial action to be undertaken by EPA, the State, or an individual (e.g.,
potentially responsible party), the lead agency must:
• Publish a notice and make the proposed plan available to the public
• Provide a reasonable opportunity for submission of written and oral comments and an
opportunity for a public meeting at or near the site regarding the proposed plan and
any proposed findings relating to cleanup standards
• Keep a transcript of the meeting and make such transcript available to the public
• Include in the proposed plan sufficient information to provide a reasonable
explanation of the preferred remedy and alternative proposals considered
Additionally, notice of the final remedial action plan set forth in the ROD must be
published and the plan must be made available to the public before commencing any remedial
action. Such a final plan must be accompanied by a discussion of any significant changes
to the preferred remedy presented in the proposed plan along with the reasons for the
changes. A response (Responsiveness Summary) to each of the significant comments,
criticisms, and new data submitted in written or oral presentations during the public
comment period must be included with the ROD.
The Upper Tenmile Creek watershed has many stakeholders, including landowners, local
communities, state and local government, and special interest groups, as well as EPA and
several other federal agencies. These stakeholders include the following:
• Upper Tenmile Watershed Steering Committee
• Upper Tenmile Technical Subcommittee
• Lewis and Clark County
• City of Helena
• Rimini Caucus
DFWP
• Montana Department of Natural Resources and Conservation (DNRC)
DEQ
• Montana Bureau of Mines and Geology
• U. S. Geological Survey
USFS
U. S. Fish and Wildlife Service (USFWS)
EPA
In October 1996, at the request of the Upper Tenmile watershed steering committee, the EPA
remedial project manager for the site began attending the committee's monthly meetings.
-------
The meetings were held in Rimini during the summer and in Helena in the winter. The
meetings, which were initiated in 1996 and are currently ongoing, provide a forum for
stakeholders to voice their issues and concerns and for EPA to respond to these comments
in a meaningful way. These meetings also enable EPA to inform stakeholders of its Removal
and Remedial Program opportunities and activities in the upper Tenmile Creek watershed.
Initially, the meetings focused on the need for information about contaminant loading and
the availability of funding for investigation and cleanup. EPA funded water quality and
quantity monitoring studies under a Section 309 grant and then under site investigation
funding. The water monitoring included a detailed loading analysis to identify point
sources and help prioritize cleanup efforts.
The Agency for Toxic Substances and Disease Registry (ATSDR) has also been active in
communicating information about site risks to the general public. ATSDR conducted a public
health assessment for the site, which was released in April 2001. In preparing and
discussing the public health assessment, ATSDR held public meetings in Rimini on May 25,
2000, and June 21, 2001.
November 1998: EPA met with a reporter from the Helena Independent Record, which resulted
in a front-page article on November 17, 1998. Increased interest led EPA and DEQ to meet
with many entities of the upper Tenmile Creek watershed and the adjacent Basin Creek/
Cataract Creek watersheds.
December 7, 1998: The Lewis and Clark County Water Protection District sent a memorandum
to EPA Superfund Branch Chief Robert L. Fox compiling public comments regarding proposed
mine waste cleanup activities in the Upper Tenmile Creek watershed. On February 25, 1999,
Mr. Fox responded with a letter to the Lewis and Clark County Water Protection District,
stating that Mike Bishop of the EPA Montana Office and Paul Peronard of the EPA Denver
Office had held numerous meetings with various potentially affected interests. Relevant
information was distributed to the Upper Tenmile Watershed Steering Committee at its
February 25, 1999 meeting.
March 22 and 24, 1999: EPA held joint public availability sessions with the USFS in Helena
and Basin regarding the proposal to use the Luttrell Pit for mine waste disposal for the
Upper Tenmile Creek Mining Area and Basin Mining Area sites.
Spring 1999: EPA met with the communities of Rimini and Basin, local watershed groups,
County Commissioners, and the Lewis and Clark County Board of Health during its
preparation of a HRS scoring package to discuss possible NPL designation. EPA held public
meetings in Helena and Rimini to discuss the NPL process. Both meetings were advertised in
a public notice in the Helena Independent Record. EPA also notified the public of the
availability of its proposed HRS scoring package (prepared on May 10, 1999). The public
was given an opportunity to voice their concerns during a public comment period held in
conjunction with the proposed listing.
Summer 1999: EPA prepared a document to provide responses to public comments on the EA
prepared by DEQ on June 24, 1999. The EA dealt with a proposed land use change at the BCM
to provide for the use of the Luttrell Pit as a mine waste repository.
July 22, 1999: EPA published in the Federal Register its proposal to add the Upper Tenmile
Creek Mining Area Site to the NPL. The announcement began a 60- day public comment period.
EPA also issued a press release regarding the proposal.
October 22, 1999: The final rule listing the site on the NPL was published in the Federal
Register.
October 28, 1999: The Upper Tenmile Watershed Steering Committee met in Rimini to hear the
concerns of residents and property owners of the watershed regarding the summer 1999 field
season of the EPA's Removal Program project. The Upper Tenmile Watershed Steering
Committee also sent a letter to Mr. Fox on November 30, 1999, which outlined concerns of
residents regarding the 1999 field season.
-------
November 1999: EPA Region VIII prepared a fact sheet which provided information on the
site history, upcoming activities, environmental progress, EPA contact persons, and
information repository locations.
December 1999: EPA conducted interviews with affected residents, local officials, and
other interested parties to assess community members' issues and concerns about the site.
In addition, EPA briefed the community about the upcoming RI.
August 2000: EPA facilitated a series of meetings with the City of Helena, DFWP, and
representatives of the community of Rimini to discuss options to augment stream flow
within Tenmile Creek below Rimini. The city agreed to temporarily allow part of
Minnehaha Creek stream flow to bypass the city's water intake structure on that tributary
and augment Tenmile Creek flows. Flow was bypassed for approximately six weeks.
September 2000: EPA issued a fact sheet summarizing site information and describing
potential remedial options being considered at the site.
December 2000: EPA sent letters to site residents providing the sample analytical results
for those residential wells that had been sampled. On January 11, 2001 EPA held a public
meeting in Rimini to explain and discuss the results of the sampling of the residential
groundwater wells, to recommend that additional tap water samples be collected and
analyzed, and to offer replacement bottled water to those residents whose tap water from
residential wells exceeded EPA's maximum contaminant level (MCL) concentrations for
drinking water.
February 21, 2001: EPA released the draft RI report for public comment.
March 23, 2001: EPA released the draft FS report for public comment.
May 3, 2001: EPA met with a joint session of the City of Helena and Lewis and Clark County
commissioners to discuss project issues and the remedial alternatives that EPA was
considering.
July 2001: EPA provided a preliminary draft of the proposed plan to agencies and site
residents to obtain public comment and feedback regarding several of the remedial options
being considered by EPA. The public expressed considerable support for providing
additional water storage and Tenmile Creek flow augmentation, although concern was
expressed over the potential loss of valuable wetlands habitat if the Travis location were
selected for a new water storage reservoir. As a result of the public comment on the draft
proposed plan, EPA identified and evaluated possible alternative locations for additional
water storage capacity in the watershed.
October 22, 2001: EPA released the proposed plan for public comment. Public hearings on
the proposed plan were held in Rimini on November 8, 2001 and in Helena on November 13,
2001. A formal public comment period was open from October 22, 2001 to November 21, 2001.
The RI, FS, and proposed plan were made available to the public in the Administrative
Record, located at the EPA Montana Office in Helena and at the Lewis and Clark Public
Library.
EPA's responses to public comments received during the public comment period are included
in the Responsiveness Summary of this ROD.
-------
Section 4
Scope and Role of Operable Unit
The Upper Tenmile Creek Mining Area Site covers a wide geographical area and exhibits a
complex array of interrelated environmental and land use factors that determine the fate
and transport of chemicals of concern (COG) with the watershed and their impact on human
and environmental receptors. To address the site contamination in a logical manner, EPA
established the following operable units (OUs) at the site:
QUO Sitewide
OU1 Red Mountain Mine
OU2 Bunker Hill Mine
OUS Luttrell Pit
OU4 Watershed
OUS Susie Mine
OU6 National Extension Mine
OU7 Peerless and Queensbury Mines
OUS Upper Valley Forge Mine
OU1, OU2, OUS, OUS, OU7, and OUS have been the subject of specific removal actions over
the last five years. At these OUs, mine waste materials have been excavated and disposed
of at the onsite Luttrell repository. Post-removal reclamation has included backfilling of
excavated areas, placement of cover soil and vegetation, including trees for soil
stabilization. AMD generally has not been addressed by the removal actions. Removal action
has been considered, but not yet taken at OU6, the National Extension Mine.
Watershed OU4 encompasses all of the other site OUs and includes all historic inactive or
abandoned mine sites located at the Upper Tenmile Creek Mining Area site. In addition to
the mine sites, OU4 also includes all other media known to be impacted by mine-related
contamination, including AMD, groundwater, surface water, stream sediments, residential
yards, and contaminated roadways. Since it addresses all mine sites and all media at the
site, this ROD is expected to be the only ROD for the site. The selected remedy for the
site includes provisions to conduct ongoing long-term monitoring of removal actions taken
at the removal OUs and to take additional remedial action at those OUs if necessary to
meet site performance standards.
-------
Section 5
Summary of Site Characteristics
5.1 Site Overview
The Upper Tenmile Creek Mining Area Site comprises approximately 53 square miles of the
uppermost portion of the Tenmile Creek watershed (refer to Figure 1-2), which extends from
U. S. Highway 12 south to the drainage divide adjoining the Basin Creek, Cataract Creek,
and Telegraph Creek watersheds. To the west, the site is bounded by the Continental
Divide. Upper Tenmile Creek flows from its headwaters to the northeast and then north
through a deep gorge between Red Mountain and Lee Mountain until it enters a relatively
wide alluvial valley as it exits the site near Highway 12. The headwaters of upper Tenmile
Creek are about five miles upstream of the community of Rimini, which is located in the
approximate center of the site. From its headwaters, Tenmile Creek flows for approximately
25 miles before entering Lake Helena. Only the uppermost 13 miles of Tenmile Creek are
located in the site.
The site lies within the Northern Rocky Mountain physiographic province, which is
characterized by a succession of distinct mountains and valleys. The upper Tenmile Creek
drainage basin is mountainous with high and sharp relief. Red Mountain, southeast of the
community of Rimini, rises to an elevation of 8,150 feet amsl and represents the highest
point in the watershed. Upper Tenmile Creek originates at an elevation of approximately
7,200 feet amsl and drops to 4,380 feet amsl at the northern boundary of the site. Lee
Mountain, directly west of Red Mountain, rises above the valley to an elevation of 7,064
feet amsl.
5.2 Site Conceptual Model
As shown in the site conceptual exposure model (Figure 5-1), contaminants may be released
from mine waste rock piles and tailings piles through surface water runoff, wind and water
erosion, infiltration/ leaching to groundwater, biotic uptake, or waste transport by human
activity. Adits may discharge contaminants to surface water or leach them to groundwater.
These releases may result in contamination of media, such as surface soil, surface water,
stream sediment, and groundwater, that then become secondary sources. The secondary
sources release contaminants in a number of ways. Contaminants in surface water may be
released to sediments (through precipitation, deposition, and adsorption), biota (through
uptake), and groundwater (through infiltration). Contaminants in soil are released
primarily to biota (through uptake), air (wind-generated dust), or interior dust
(tracking). Contaminants in groundwater may discharge to surface water, and contaminants
in sediment may be released to surface water (through adsorption/desorption) and biota
(through uptake). Cycling of contaminants among site media will also occur. For example,
metals may partition between surface water and sediments and migrate between surface water
and groundwater in gaining and losing stream reaches.
Potential human receptors include site residents, workers, and recreationists. Biota
receptors are terrestrial and aguatic species, including piscivorous birds and mammals.
Key potential exposure pathways are ingestion of groundwater and surface water, ingestion
of home-grown produce or contaminated fish/prey, direct contact or incidental ingestion of
soils, sediments, and dust inhalation, ingestion, or direct contact.
5.3 Known and Suspected Sources of Contamination
Investigations at the site have documented releases of hazardous substances containing
elevated concentrations of arsenic and metals (cadmium, copper, lead, zinc, and others)
that may pose risks to human health and the environment. COCs have been observed to exceed
established human health or environmental standards, including EPA MCLs for drinking water
and state water guality criteria for aguatic life. These COCs are derived primarily from
uncontrolled sources of waste rock, tailings, AMD and acid rock drainage (ARD) , and
-------
Primary
Sources
Primary
Release
Mechanisms
Secondary
Sources
Second any
Release
Mechanisms
Exposure
Pathway
Figure 5-1
Site Conceptual Exposure Model
Potential
Receptors
Human
33
in
a.
3
5
0
*
*
3D
i
o
3i
*"•
Biota
>
fi'
is
1
S"
VI
-t
I
Of
"i
f>
*
DO 2
S K
eg —
3 1
S 0
ST w
S
f%
**
Acid Mloa
Drainaga
Tailings
r
»*
< — k
U«hinty
Surface- Water
Runoff
Waste Erosion
OAW
Waste Erosidfi
(Wind)
Waste Transport :
(Human Activity)
1
!
^
..
_^
0,»^,
Surface Watw
fstneams, creeks,
ponds
J
i
pools)
AdSOnUtiOrt/
Ossorption/
Prttiuitation
,
Instr
S&to
(slreams
Suriac
*
•nent
, ponds)
Btotic Uplaka
Deposition
^
Tracking/
Wind Transport
^
Ik
Ingesliwof
^nM?
Direcl Cmtacv
Ingestign
(Surface water)
(ngastton of
Produce
ingnttonof
Diced Conlad/
(soli/sediments}
Duat inhalation'
Dwect Contact
p
•
9
•
•
•
•
*
0*
•
*
*
•
*
•
*
*
Fig 5-1 .ppt
"Open circle indicates qualitative assessment only
-------
contaminated groundwater, surface water, soil, and stream sediments.
Mining Wastes
Mining wastes at the site are a principal source of contamination and are generally
composed of waste rock and tailings. Waste rock material consists of rocks excavated or
removed from the ground during mining operations, but not processed for mineral recovery.
Composition of this material can vary greatly depending upon specific mine operations and
geology. Some waste rock may contain COCs similar to that of background or host rock not
associated with the mineralized ore bodies. Other waste rock may be highly mineralized,
ore-grade materials with high concentrations of metals and arsenic. Waste rock can also
vary greatly in size, from fine-grained to cobble or larger-size material.
Tailings are solid-matrix waste products from ore processing or concentrating operations.
Tailings are typically fine-grained material deposited hydraulically in impoundments or
settling ponds. There are only a few tailings deposits at the site because the abandoned
mines typically did not utilize ore processing facilities. Most of the abandoned mine
sites exhibit primarily waste rock materials.
Exposure of sulfide-bearing waste rock and tailings materials to oxygen and water-rich
environments can result in the production of AMD and ARD, which are discussed in more
detail below. Waste rock and tailings deposits are usually unvegetated or sparsely
vegetated, in part because elevated metals concentrations and low pH, and may be
susceptible to erosion by wind, precipitation, and surface water. In addition, when
subject to precipitation and surface water flow, COCs in these wastes may also be leached
into surface water, groundwater, sediments, and soil.
Acid Mine and Acid Rock Drainage
AMD is metal-bearing acidic water discharged from underground mine workings through adits,
tunnels, or shafts. ARD is a similar discharge of metal-bearing acidic water resulting
from water seeping or flowing through and from acid-generating materials, such as waste
rock, tailings piles, or mineralized rock formations. When host rock bearing sulfide
minerals become exposed to water, the sulfide undergoes an oxidation reaction that
produces sulfuric acid (H2S04). AMD and ARD occur when the amount of sulfuric acid
generated is greater than the acid neutralizing capacity of the host rock. The decreased
pH of AMD/ARD increases the solubility of many metals; thus, AMD and ARD waters can have
highly elevated concentrations of metals. These waters freguently discharge directly into
surface water and are significant sources of metal loading to surface waters.
Contaminated Surface Waters
Contaminated surface water (including adit discharges) at the site may flow directly into
tributaries under normal flow conditions or under storm or snowmelt runoff conditions.
Storm events transport released contaminants and waste rock materials to the tributary
drainage channels that convey these contaminants downstream to upper Tenmile Creek. The
deposited waste material may continue to contribute to metals loading through leaching.
Contaminated Stream Sediments
Contaminated stream sediments are typically the result of waste rock and tailings
materials deposited in streams through erosional mechanisms and the adsorption and
precipitation of metals from the water column. This deposited waste material can
contribute to metals loading through leaching. In addition, contaminated stream sediments
can become a source of contaminant releases to surface water when precipitated COCs become
remobilized due to dissolution and resuspension.
5.4 Investigation and Sampling Approach
EPA relied on the use of historical data to the extent practicable and limited the
collection of RI data during the 2000 field season to only those data necessary to support
the FS evaluation, risk assessment, and cleanup decision-making process. Historic data
sets were evaluated in the data summary and usability report (COM Federal Programs
-------
Corporation [CDM] 2000).
5.4.1 Waste Source Areas
To fully delineate the nature and extent of mining-related contamination at the site, it
was determined necessary to document environmental conditions at all historic mine sites
in this watershed. EPA determined that a reconnaissance would be conducted at all known
and previously unknown mine sites, but that the degree or intensity of each mine survey
would be based on the level of existing knowledge of the site and on a field assessment of
potential human health or environmental impacts. A total of 150 mine sites were identified
at the site.
The focus of the 2000 investigation was to:
• Identify and document the location of unknown mine sites.
• Verify the location of all known mine sites.
• Conduct a survey at all mine sites to determine if sampling was reguired (this was
based on the completeness of the historic data set for each mine site and an
evaluation in the field of potential human and environmental health risks).
• Sample, as necessary, to complete the data set for the key mine sites (a sampling
decision logic was used to determine sampling intensity).
5.4.2 Surface Water
EPA determined that additional surface water monitoring in the watershed was needed to
better define specific contaminant loadings from selected areas of waste sources. EPA
collected additional surface water guality samples from the streams, adit discharges,
seeps, and springs within the vicinity of Rimini and at selected sites in the other
subareas (Upper Tenmile Creek/Monitor Creek, Banner Creek/Ruby Creek, Beaver Creek,
Minnehaha Creek, Bear Gulch/Walker Creek, and the Tenmile Mainstem).
EPA also determined that it would be desirable to collect surface water samples during
storm events in order to gather data with respect to COG loading that can occur during
these storms. However, the summer of 2000 was one of the driest on record at the site. The
only substantial rainfall event occurred over the July 4th holiday weekend when field
crews were not on site. Thus, a major rainfall runoff event was not sampled. Several
smaller rainfall or snowmelt events were sampled in late September and early October 2000.
5.4.3 Sediment
EPA sampled stream sediment in depositional areas near the mouths of Beaver Creek, Bear
Gulch, and Walker Creek and downstream of identified waste source areas in these
tributaries. EPA also collected additional sediment samples in the vicinity of
Rimini to bracket known source areas and perform grain size analysis on select sediment
samples from the Tenmile Creek mainstem. Mercury was analyzed in sediment at a number of
locations to better understand the extent of mercury contamination, primarily near the
Banner Creek Tailings, which was suspected because of the historical use of mercury for
amalgamating gold in placer mining operations.
5.4.4 Groundwater
To accurately establish the nature and extent of groundwater contamination and groundwater
impact on the surface water guality in Tenmile Creek, EPA located, documented condition
of, and sampled pertinent existing residential and water supply wells within the site. EPA
also sampled numerous springs and seeps within each subarea to get a better understanding
of both background groundwater conditions throughout the site and to identify any
potential areas of concern downgradient of individual mine sites.
-------
5.4.5 Residential Yards and Roadway Areas
EPA sampled soil from residential yards to determine potential risks to residents in the
community of Rimini and in the Landmark Subdivision (near the Tenmile Water Treatment
Plant). EPA also sampled roadway materials at select locations along Rimini Road in Rimini
to investigate the significance of prior use of mine waste materials for road repair work.
5.5 Types of Contamination and Affected Media
Contamination in Tenmile Creek is primarily related to the residual waste rock/ tailings
piles and discharging mine adits at many of the approximately 150 abandoned hard rock mine
sites located in the watershed. Environmental data gathered from these mine sites
demonstrate the release of arsenic, cadmium, copper, lead, zinc, and other hazardous
substances that pose unacceptable risks to human health and the environment. These COCs,
which are present in the groundwater, surface water, stream sediments, mine waste
material, and residential soils, often exceed established regulatory standards for
drinking water and aquatic life, and exceed levels in soil considered protective of public
health and terrestrial ecological receptors such as plants and animals. Since these mine
wastes may potentially contaminate drinking water supplies for local residents and the
City of Helena, they pose a potential health threat. Tissue samples from Tenmile Creek
fish have shown elevated levels of arsenic. Table 5-1 provides information about
the principal COCs at the site, noting their average and maximum concentrations in site
media, as well as estimated quantities of media impacted.
5.5.1 Mine Site Waste Rock and Tailings
RI data indicate that the waste material at most historic mine sites present risks to
human health and the environment. Some sites would pose risks to human health if they were
developed for residential use, but do not pose risks to recreational users. Additionally,
some sites do not pose risks for any type of human use, but pose risks to terrestrial
ecological receptors. In the Tenmile Creek Near Rimini, Beaver Creek, and Minnehaha Creek
subareas, nearly all mine sites present a potential risk to human health (under either
residential or recreational exposure scenarios) and to terrestrial ecological receptors.
The RI identified 31 mine sites that pose a potential risk to aquatic receptors during
runoff or high stream flow conditions.
Analytical results from excavated soil pits at selected mine sites indicate that, in
general, COG concentrations in the relic soils beneath waste material are elevated
relative to background soil concentrations and risk-based human health preliminary
remediation goals (PRGs) and ecological toxicity reference values (TRVs). This enrichment
of the relic soil indicates a downward migration, or leaching, of the COCs. Although
trends vary between mine sites and among the COCs, the 6-to 12-inch soil interval
generally has a greater degree of COG accumulation than the 24-to 30-inch interval.
Because background soil conditions vary throughout the site, the depth to which
contaminated soil may need to be removed during cleanup will be determined on a
site-by-site basis during remedial design. Additionally, the degree to which COCs in soil
could migrate from a site (e.g., soil to groundwater migration) will need to be determined
during the design phase and factored into the remedial design.
5.5.2 Acid Mine and Acid Rock Drainage
The investigation for AMD/ARD was concurrent with the investigation for surface water. The
RI reconnaissance noted 37 discharging adits in the site. These adit waters, frequently
with acidic pH and elevated metal concentrations, are significant sources of COG loading
to the Tenmile Creek watershed. This is covered more thoroughly in the next section.
5.5.3 Surface Water Quality and Contaminant Loading
Seasonal surface water flow in the mountainous watershed containing Tenmile Creek and its
-------
Table 5-1
Summary of Contamination and Affected Media
Media
Primary COCs
COC Concentration
Quantity/Volume of
Waste
Water
Surface Water
Acid Mine
Drainage
Groundwater
Aluminum3
Arsenic
Cadmium
Copper3
Iron
Lead
Manganese
Zinc
Arsenic
Cadmium
Iron
Lead
Manganese
Zinc
Arsenic
Cadmium
Iron
Lead
Manganese
Zinc
Average1
(M9/L)
15.9-779
2.7-345
1.1 -37
2.0-42.1
230-4,256
1.1 -46
25 - 786
26-2,821
5.4-2,870
2.8-126
436-39,075
3.0-120
71 -5,802
33-14,861
5.1 -54
0.3-18.4
901 -13,838
1.4-131
70-5,699
36-6,499
Maximum
(M9/L)
46.5004
10,000
7024
8604
147,000
1,394
30.7704
82,500
27,700
724
374,000
2,150
31,500
93,500
3.4902
237
24.9002
2.4602
11.5002
50.1002
About 7 miles of Tenmile Creek
moderately to severely degraded
Discharges from approximately
35 adits, with combined flow
totaling about 75 gallons per
minute
Shallow aquifer near Rimini
severely degraded
Solid
Waste Rock
and Tailings
Residential
Yards
Roadways
Stream
Sediment
Arsenic
Cadmium
Lead
Mercury
Zinc
Arsenic
Lead
Arsenic
Lead
Arsenic
Cadmium
Lead
Zinc
Average
(mg/kg)
62-12,350
0.4-85
42-7,090
0.2-9.3
59-1,450
193-407
157-494
2,668
2,373
26.9-3,482
0.8-45
43 - 593
104-2,235
Maximum
(mg/kg)
121,000
620
48,700
112
82,456
1,250
1,258
6,485
6,769
68,300
666
3,050
68,600
340,000 cubic yards of waste at
150 mine sites
Estimated 63 of 82 residences
affected and 20,000 cubic yards
of contaminated soil
Approximately 5,000 linear feet
of roadway in Rimini containing
waste rock
About 4,500 feet of stream
channel degraded
Note:
1 Range shown is of average concentrations by subarea.
2 Includes data from shallow piezometers in waste materials at Lee Mountain site.
3 Summary statistics for aluminum and copper in surface water are based upon dissolved
concentrations reported in the ecological risk assessment (COM 2001 a).
4 Maximum surface water concentrations reported are for the dissolved fraction, not the total
recoverable fraction.
Table 5-1 .wpd
-------
tributaries is highly variable. Flow predictions, based on hydrologic modeling and 30-year
flow trends, indicate that the estimated average monthly natural flow in Tenmile Creek at
the downgradient end of the site (without subtracting the Helena water supply system
withdrawals) would range from approximately 3.9 cubic feet per second (cfs) in January to
122 cfs in May. For seven months of a typical year, flow in Tenmile Creek leaving the site
is predicted to be less than 10 cfs under natural conditions (i.e., without the water
system withdrawals). Actual flow rates in Tenmile Creek are considerably less than the
estimated natural flows because of the Helena water supply system withdrawals. During mid-
to late-summer, measured flow rates in Tenmile Creek are often less than 5 cfs, with
certain reaches dewatered completely. DFWP has determined that a stream flow rate of
approximately 4 cfs in Tenmile Creek would provide habitat suitable for rainbow and brook
trout. As stream flows drop below 4 cfs, fish habitat and fish production are reduced
proportionally. Stream reaches downstream of the Helena water supply system Tenmile Creek
intake structure in Rimini have very poor water guality because, in addition to the low
flow of less than 4 cfs, AMD and discharge of contaminated groundwater adds significant
contaminant loading to the stream.
Helena' s water supply system includes Chessman Reservoir and Scott Reservoir with storage
capacities of 350 and 196 million gallons of water, respectively. Diversion structures for
city water are located on Banner Creek, Beaver Creek, Tenmile Creek, Minnehaha Creek,
Moose Creek, and Walker Creek. Once captured, this water is conveyed via underground pipe
to the Tenmile Creek water treatment plant. The treatment plant was constructed in 1990
and has a maximum treatment capacity of 9 mgd.
Table 5-2 summarizes water guality in Tenmile Creek and key tributaries for the synoptic
sampling event that occurred June 20-22, 2000 for the RI. Surface water guality is highly
variable, but generally water guality is good in the uppermost tributaries of the site and
degrades in the downstream direction. In the lower portion of the watershed near the
city's water treatment plant, concentrations of COCs often exceed or are very near chronic
aguatic life standards for aluminum, cadmium, copper, lead, and zinc and are near human
health standards for arsenic. Impacts in Tenmile Creek are greatest near the community of
Rimini, where COG concentrations greatly exceed aguatic life standards for aluminum,
cadmium, copper, lead, and zinc. In this area, human heath standards have been exceeded
for arsenic, cadmium, iron, lead, and manganese, indicating a risk to public health if
this water is used for drinking.
Contaminant loading calculations were presented in the RI (CDM2001b) and RI/FS addendum
(CDM2001c). For individual mine sites, when possible, net loads were calculated based upon
discharge and water guality measurements from immediately upstream and downstream of the
mine site. This method accounted for contributions of COCs from different media (adit
discharge, surface water gains from groundwater, and contaminated waste material and
sediment). If only adit discharge data were available, the loading from the adit was
calculated. Loading calculations for the top 25 overall sources of COG loading to surface
water are summarized in Table 5-3.
Mine sites contributing significantly to the contamination of surface water via the
discharge of adit water and/or contaminated groundwater include the Susie, Lee Mountain,
National Extension, Red Water, Red Mountain complex, Armstrong, Little Sampson, and Bunker
Hill. The two largest contributors of arsenic to surface water in the upper Tenmile Creek
watershed are the Susie mine site adit and the Lee Mountain site. The Susie adit, the Lee
Mountain site, and the Armstrong site are the largest contributors of cadmium to Tenmile
Creek or its tributaries. The largest mine site contributors of copper are the Red
Mountain complex and the Armstrong site. The largest contributors of lead are the Red
Mountain complex, Bunker Hill, National Extension, Little Sampson, and the Lee Mountain
sites. The Little Sampson, Armstrong, and Susie mine sites contribute the largest zinc
loads in the basin. Waste removal and reclamation work has been conducted on the Red
Mountain complex, the Susie site, and the Armstrong site in the last two years, although
none of the cleanup actions addressed adit discharges.
-------
Table 5-2
Representative Baseflow Water Quality in Tenmile Creek and Key Tributaries
June 20-22, 2000
Station
Tenmile Creek above Monitor Creek
Monitor Creek at Mouth
Tenmile Creek above Ruby Creek
Ruby Creek at Mouth
Banner Creek at Mouth
Poison Creek at Mouth
Tenmile Creek above City Diversion
Spring Creek at Mouth
Tenmile Creek below Spring Creek
Moore's Spring Creek at Mouth
Beaver Creek above City Diversion
Minnehaha Creek above City Diversion
Tenmile Creek above Minnehaha Creek
Tenmile Creek at Moose Creek
Campground
Tenmile Creek above Bear Gulch
Bear Gulch at Mouth
Tenmile Creek above Walker Creek
Walker Creek above City Diversion
Tenmile Creek at Water Treatment Plant
Date
6/22/2000
6/22/2000
6/22/2000
6/22/2000
6/22/2000
6/20/2000
6/20/2000
6/21/2000
6/20/2000
6/20/2000
6/21/2000
6/21/2000
6/21/2000
6/21/2000
6/20/2000
6/20/2000
6/20/2000
6/20/2000
6/20/2000
Discharge
(cfs)
2.263
1.367
3.153
1.26
3.53
0.06
7.9
0.09
1.6
-
1.9
1.6
1.58
3.484
3.216
0.02
3.828
0.38
4.6
Arsenic
DISS TOTAL
U>g/L) (pg/L)
1.40 2.1
0.68 0.77
1.10 1.3
2.7 3.2
0.85 1.1
13. 9.
4. 4.
10.9 11.1
22. 29,
46. 58,
4 4.8
3. 3.
22.5 27.1
21.6 24
23.2 25.8
2.4 2.7
22 24.9
0.99 1.2
18 2^
Cadmium
DISS TOTAL
tel/L) (pg/L)
1U 0.06
0.15 0.18
0.05 0.06
0.36 0.26
0.04 0.04
34. 33.
0.63 1.
0.94 1.
2.8 3.
4.6 5.
0.12 0.14
1.5 2.
1.7 1.8
1.40 1.5
0.88 0.96
1U 1U
0.83 0.9
1U 1U
0.62 1 .
Copper
DISS TOTAL
toa/L) U>g/L)
1 .00 1 .6
1 .40 2.
3.60 1.8
2. 2.3
1.9 2.2
362. 330.
4.8 6.
8.5 9.1
8.2 10.
7.4 7.
17 22.9
5.8 6.
7.1 6.5
4.2 4.9
4 4.6
0.33 0.68
129 4.3
1.30 1.6
3.3 4.
Lead
DISS TOTAL
toa/L) U>g/L)
0.15 0.97
0.17 0.69
0.76 0.49
1.0U 1.4
0.12 0.51
82. 87.
1U 2.
0.07 0.25
2.9 5.
1.7 7.
0.08 0.58
1U 1.
1.3 2.4
0.69 1.6
0.32 0.81
1U 0.56
5.5 0.66
0.091 0.11
1U 1U
Zinc
DISS TOTAL
toa/L) toa/L)
5.60 8.5
22.9 26.2
12.8 11.1
51 .4 45.3
12.2 16.2
4410. 4400.
130. 140.
89. 85.2
442. 450.
742. 690.
21.5 25.2
246. 230.
358. 384.
31 1 322.
159 169.
11.2 5.2
210 148.
4.20 4.5
143 140.
Hardness as
CaCo3
(mg/L)
20
12
24
17
32
62
18
28
26
89
24
20
56
48
40
88
52
68
46
Notes:
Values in bold exceed aquatic chronic water quality criteria
Underlined values exceed human health criteria
Table 5-2 Water Quality.xls
-------
Table 5-3
Ranked Top 25 Mine Site Sources of Loading to Surface Water
Ranked Mine Site
Lee Mountain
Red Mountain Complex
Susie
Bunker Hill
National Extension
Little Sampson
Red Water
Upper Valley Forge
Peerless Jenny Adit #2
Queensbury
Peerless Jenny Adit #1
Former Stanton
Armstrong
Alley Fraction
Bunker Mile
Atlas
Castle Rock
Banner Creek Tailings
Johny #2
Evergreen #3 and S.P. Bassett
Jumbo
Helena
1900
Johny #1
W.A. Allev
Subarea
TR
TR
TR
TR
BC
TR
TR
TR
RC
RC
RC
TR
MC
TR
TR
RC
TR
RC
TR
TR
TR
RC
UT
TR
RC
Adit
Discharge?
Y
Y
Y
Y
Y
N
Y
Y
Y
Y
Y
N
Y
N
N
Y
N
N
Y
N
N
Y
Y
Y
Y
Total Top 25 Mine Site Loads
Background Load
Total Basin Load (measured at water treatment plant)
Unaccounted Load
Arsenic
LOAD % of
(Ibs/day) TOTAL
0.18 29.13%
0.01 1 1 .78%
0.41 66.45%
0.013 2.10%
0.045 7.34%
0.032 5.18%
0.021 3.33%
0.0018 0.30%
0.00005 0.01%
0.00013 0.02%
0.0002 0.03%
0.00032 0.05%
-0.002 -0.32%
0.00076 0.12%
0.00086 0.14%
0.00043 0.07%
0.00065 0.11%
0.00064 0.10%
0.0013 0.22%
0.00029 0.05%
-0.0012 -0.19%
0. -0.01%
0.000009 0.00%
0.00030 0.05%
0.0010 0.16%
0.718 116.24%
0.0676 10.95%
0.62 100.00%
-0.168 -27.19%
Cadmium
LOAD % of
(Ibs/day) TOTAL
0.011 14.49%
0.0061 7.98%
0.014 17.78%
0.0058 7.64%
0.00093 1 .22%
0. 0.00%
0.0053 6.95%
0.00012 0.15%
0.0006 0.79%
0.000077 0.10%
0.00004 0.05%
0.000044 0.06%
0.013 17.12%
-0.00072 -0.95%
0.0 0.00%
0.000045 0.06%
0.000017 0.02%
0.00011 0.14%
0.000018 0.02%
0.000016 0.02%
0.00059 0.78%
0.0000014 0.00%
0.000013 0.02%
0.0000095 0.01%
0. 0.00%
0.057 74.47%
0.018 23.83%
0.08 100.00%
0.001 1 .70%
Copper
(ibs°/2aDy) % °f TOTAL
0.015 2.40%
0.051 8.29%
0.0065 1 .05%
0.0097 1 .57%
0.0067 1 .09%
0.007 1 .05%
0.0011 0.18%
0.00045 0.07%
0.0072 1.17%
0.00035 0.06%
0.0003 0.05%
0.00019 0.03%
0.03 4.86%
0.0053 0.86%
0.00086 0.14%
0.000094 0.02%
0.00016 0.03%
-0.00062 -0.10%
0.000084 0.01%
0.000034 0.01%
0.0011 0.17%
0.0022 0.35%
0.000057 0.01%
0.00001 1 0.00%
-0.00072 -0.12%
0.144 23.24%
0.11 17.11%
0.62 100.00%
0.368 59.66%
Lead
LOAD % of
(Ibs/day) TOTAL
0.0065 5.78%
0.037 32.74%
0.00076 0.67%
0.025 22.22%
0.022 19.26%
0.016 14.22%
0.000097 0.09%
0.00082 0.73%
0.0004 0.36%
0.00072 0.64%
0.0007 0.62%
0.00018 0.16%
-0.0065 -5.78%
0.0012 1.11%
0.00017 0.15%
0.00029 0.25%
0.00013 0.12%
0.00016 0.14%
0.0000019 0.00%
0.00039 0.35%
-0.00065 -0.58%
0.00015 0.13%
0.00020 0.18%
0.00013 0.12%
0.00022 0.19%
0.106 93.86%
0.013 11.25%
0.11 100.00%
-0.006 -5.11%
Zinc
LOAD % of
(Ibs/day) TOTAL
1.6 14.45%
0.75 6.78%
1.84 16.59%
1 .26 11 .38%
0.12 1.04%
3.11 28.10%
1.22 10.99%
0.020 0.18%
0.083 0.75%
0.015 0.13%
0.01 0.09%
0.0085 0.08%
2.56 23.13%
0.0034 0.03%
0.011 0.10%
0.00089 0.01%
0.0020 0.02%
0.0037 0.03%
0.0018 0.02%
0.0015 0.01%
0.095 0.86%
0.0044 0.04%
0.0015 0.01%
0.0020 0.02%
0.0062 0.06%
12.719 114.91%
0.36 3.27%
11.07 100.00%
-2.012 -18.18%
Note:
UT = Upper Tenmile Creek/Monitor Creek Subarea
RC = Banner Creek/Ruby Creek Subarea
TR = Tenmile Creek Near Rimini Subarea
BC = Beaver Creek Subarea
MC = Monitor Creek Subarea
Table 5-3 Load Accounting.xls
-------
As was discussed in Section 5.4.2, because 2000 was one of the driest years on record at
the site, storm water data for a major storm event were not collected. During storm
events, erosion of contaminated mine wastes and soils can enter surface water drainages,
substantially increasing the loading of COCs to surface water. Storm water can also
infiltrate into mine waste piles and leach contaminants into subsoils and groundwater.
Storm water can also infiltrate into mine workings, and increase adit discharge amounts.
5.5.4 Stream Sediment Quality and Potential Impacts to Surface Water
Sediment data from the 2000 RI were scored based on the number of exceedances of risk-
based ecotoxicity criteria. These were then grouped into three gualitative classes: poor
guality, moderate guality, and good quality. Stream reaches with the best sediment quality
are located in the headwaters of Tenmile Creek. Sediment quality in Tenmile Creek
deteriorates immediately upgradient of Poison Creek; sediment quality is either moderate
or poor from this point downgradient to the water treatment plant. Sediment sampling
stations with the worst sediment quality are located near Rimini and in the Tenmile Creek
Mainstem Subarea (i.e., downgradient of Minnehaha Creek). Poor sediment quality occurs
within Tenmile Creek above the Red Water adit, below Moore's Spring Creek, and above
Minnehaha Creek. Nearly all of the sediment samples collected in Tenmile Creek have poor
quality from below Moore's Spring Creek to above Minnehaha Creek. Poor sediment quality in
Tenmile Creek was observed below Moose Creek (probably not from Moose Creek) and below
Bear Gulch within the Tenmile Creek Mainstem Subarea. Most tributaries between Poison
Creek and Walker Creek had moderate sediment quality; however, Spring Creek and Moore's
Spring Creek had poor sediment quality, and Moose Creek and Walker Creek (above the city
diversions) had good quality sediment. Sediment in Beaver Creek was of moderate quality
due primarily to copper, but also due to high concentrations of arsenic, cadmium, and
zinc.
5.5.5 Groundwater Quality
Groundwater data used for the RI included historic data for wells as well as data for
wells, seeps, and shallow piezometers sampled during the 2000 investigation. Groundwater
data were evaluated for residential wells located in the community of Rimini and in
developed northern portions of the site.
Data indicated that groundwater contamination from historic mine sites is most severe in
the Rimini area and on the northwestern flank of Red Mountain, downgradient of the Red
Mountain complex. Groundwater contamination is also apparent in the upper portions of the
Monitor Creek and Upper Tenmile Creek tributaries (downgradient of the BCM) and locally at
specific mine sites scattered throughout the site.
Contaminated groundwater beneath the community of Rimini and in the areas where
recreational cabins are located on the northwestern flank of Red Mountain pose the
greatest threat to human health. From a human health perspective, sites considered high
priority relative to groundwater are the Susie, Lee Mountain, and the Red Mountain
complex. Groundwater contamination at more remote mine sites will not impact human health
unless these areas are developed in the future. Local groundwater contamination at remote
mine sites, however, may impact aquatic life if the groundwater discharges to surface
water and results in exceedances of aquatic water quality criteria.
Elevated arsenic concentrations are pervasive in the groundwater in the Rimini area and in
the northern portion of the Tenmile Creek Mainstem Subarea. Concentrations of arsenic were
frequently detected in samples collected in these areas at concentrations above the state
human health standard. High arsenic concentrations in the Rimini area are indicative, in
some cases, of AMD from historic mine sites. However, elevated arsenic concentrations in
groundwater (less than about 100 micrograms per liter [ug/L]) also may be a product of
natural mineral dissolution. In the northern portions of the site, pervasive arsenic
concentrations appear to be a product of the local mineralogy.
-------
5.5.6 Residential Yards
The RI also characterized the surface soil contamination at residences in the community of
Rimini relative to possible threats to human health as a result of contaminated soil and
dust ingestion. Surface soil samples were collected in 2000 from 26 residential yards in
Rimini and in the Landmark Subdivision at the mouth of the Tenmile Creek canyon. This
sampling included both general yard sampling and the collection of samples from children's
play areas. Yard samples were also collected from selected cabin sites outside the
community of Rimini. Analytical data from the residential yard samples indicate that
surface soil contamination occurs at a majority of the residences in Rimini and at
Landmark Subdivision residences near two historic mill sites. All play areas sampled had
surface soil arsenic concentrations that exceeded the residential PRG for arsenic,
indicating a potential health risk to children who play in these areas.
5.5.7 Contaminated Roadways
Soil samples were collected from below the road surface at two locations on Rimini Road to
confirm that contaminated mine waste material had been used to repair road sections washed
out during a major flood in 1981. The analytical data from these samples indicate that
portions of the roadbed contain mine waste material that exceeds residential PRGs for
soils. This material is not an immediate threat to residents since it is currently buried
beneath the surface of the roadbed; however, EPA is concerned that future exposure may
occur as the road surface erodes from use and is graded for routine maintenance, and that
this material could be washed into the stream during significant flood events.
5.6 Contamination Location and Routes of Migration
5.6.1 Lateral and Vertical Extent of Contamination
Waste rock and tailings contamination is generally limited in lateral and vertical extent
to discrete waste areas in the general vicinity of waste rock piles at individual mine
sites. The density of these mine sites is greatest in the vicinity of Rimini.
Surface water contamination is extensive through the site. Water guality in headwater
tributaries is generally good when each enters Tenmile Creek; however the headwaters of
Tenmile Creek and Monitor Creek exhibit poor water guality from close proximity to the
BCM. The most severely impaired reach of Tenmile Creek is below Poison Creek and through
the Community of Rimini because of the high density of mine sites contributing significant
contaminant loads to the creek and decreased flows due to City of Helena water diversions.
Surface water guality generally improves downstream in the Tenmile Creek Mainstem Subarea,
but still shows exceedances of human health and aguatic standards. Surface water on
tributary drainages may also be impacted locally by individual mine sites depending on the
mine site mineralogy, the proximity of waste materials to tributaries, and the volume and
guality of adit discharges.
Sediment contamination generally follows trends similar to surface water contamination,
with extensive contamination in Tenmile Creek below Poison Creek and throughout the reach
flowing through Rimini.
Groundwater contamination is extensive near Red Mountain and in Rimini, with
concentrations exceeding human health criteria. Arsenic contamination is pervasive
throughout the Tenmile Creek Mainstem Subarea, most likely due to local mineralogy.
Otherwise, groundwater contamination is limited to localized impacts from individual mine
sites.
The extent of residential soil and play yard contamination is generally limited to
residences in the Community of Rimini; however, contamination was found at some
residential yards in the Landmark Subdivision at the mouth of the Tenmile Creek canyon.
-------
The extent of roadway contamination is limited to portions of the road repaired following
the 1981 flood.
5.6.2 Contamination Migration
The mobilization of COCs is dependent upon several factors, including: (1) media type, (2)
chemical concentration, (3) reaction rate, (4) rate of surface and subsurface water flow
removing contaminants and allowing the reactions to continue towards completion, (5)
erosion of soil-bound contaminants via storm water runoff and soils/sediments carried by
such flow, (6) sorption coefficients; and (7) uptake and accumulation of contaminants by
plants and animals.
COCs can be transported from waste rock and tailings through surface water or wind
erosion, mass wasting, or to groundwater through leaching.
Contaminated surface water (including adit discharges) discharged at the site may flow
directly into tributaries under normal flow conditions or under storm runoff conditions.
Storm events transport released contaminants and waste rock materials to the drainage
channels that convey these contaminants downstream to upper Tenmile Creek. The deposited
waste material may contribute to metals loading through leaching. In addition,
contaminated stream sediments can become a source of contaminant releases to surface water
when precipitated COCs become re-mobilized due to dissolution and resuspension. In
general, iron-arsenic complexes that remove arsenic from solution are not subject to
dissolution unless low pH or reducing environments (e. g., wetlands) are encountered.
Contaminated surface waters also seep into the subsurface, contaminating the subsurface
soils and groundwater at the site. Contaminated groundwater migrates downgradient mostly
within fractured bedrock and within alluvium. Regional groundwater flow is generally
toward the north. At higher elevations, groundwater moves through fractures, fissures, and
other voids in competent bedrock toward the valley bottoms where it discharges to
unconsolidated alluvial material along the stream channels and may subseguently resurface
as a contaminant source to the surface water.
5.6.3 Exposure Pathways
Human exposure to COCs at the site is primarily via three routes. These routes are
incidental ingestion of contaminated soils and dust, including waste rock or tailings,
ingestion of contaminated surface water, and ingestion of contaminated groundwater.
Contaminant exposure to aguatic life is primarily via direct contact and ingestion of
dissolved metals in surface water and contaminated bottom sediments. Exposure pathways are
discussed more fully in Section 7 and detailed information is presented in the final human
health risk assessment (CDM 2001d) and ERA (CDM 2001a).
-------
Section 6
Current and Potential Future Land and Water Use
6.1 Land Use
The majority of land in the upper Tenmile Creek watershed is publicly owned and managed by
the USFS. However, the valley bottoms of the Tenmile Creek mainstem and several of the
major tributaries are privately owned through the patented mining claims associated with
the numerous historical mine sites in the watershed. Patented mining claims are also
located above the valley bottoms in mineralized areas of the Banner Creek/Ruby Creek,
Beaver Creek, Minnehaha Creek, Tenmile Creek Near Rimini, and Upper Tenmile Creek/Monitor
Creek Subareas. The highest density of patented claims are on the northern and western
slopes of Red Mountain, on the eastern slope of Lee Mountain, and near the bankrupt BCM.
Residential development is located primarily in the immediate Rimini area and in the
northern portion of the site near U. S. Highway 12. Recreational or occasional-use
residential cabins are located in numerous tributary drainage basins, but are concentrated
predominantly in the vicinity of Rimini. Several ranches are located where the topography
is relatively gentle and livestock are grazed throughout the watershed, either on private
lands or USFS grazing leases. Future residential development is expected to follow current
trends. Properties near Highway 12 are being subdivided and developed, but, with the
exception of a handful of parcels near the Lower Tenmile Mill and Kelly Mill sites, most
are not near historic mining facilities. New houses and cabins are being built and
occupied, particularly on a part-time basis, on mining claims in and near Rimini. The
possible pavement of Rimini Road by the Federal Highway Administration and construction of
a community water system for Rimini may increase the pressure for additional residential
development. Current residents, preferring the rural nature of the community, generally
are not supportive of significant future development.
There is no current commercial land use at the site. Historically, numerous commercial
mining operations and a rail line existed at the site. The only commercial mine to operate
after the mid-1950s was the BCM, which closed in about 1995. Commercial logging sales also
are conducted occasionally, but the site has not been intensively logged. EPA is not aware
of any plans for future commercial development at the site.
The land in the upper Tenmile Creek watershed is used for a variety of recreational
purposes such as hunting, hiking, camping, four- wheeling, mountain biking, snowmobiling,
recreational mining, and fishing. Increased recreational use is anticipated as new
residential homes and recreational cabins are built in the future and as site cleanup
activities improve water guality, fish habitat, and environmental conditions at the site.
6.2 Water Use
The upper Tenmile Creek watershed is the primary source of potable water for the City of
Helena. Approximately 70 to 80 percent of Helena's potable water comes from the watershed.
The city withdraws water from Tenmile Creek and its tributaries at five locations. In
addition, the city operates two water storage reservoirs in the basin. Chessman Reservoir,
located in the headwaters of Beaver Creek, has a capacity of 550 million gallons (1,688
acre-feet). Scott Reservoir, located in the headwaters of Ruby Creek, has a capacity of
194 million gallons (595 acre-feet). Chessman Reservoir is partially filled by an inter-
drainage diversion from Banner Creek using the Red Mountain flume. The location of the
city's water diversion, storage, and treatment facilities at the site are shown on Figure
1-2.
Thirteen residences within the community of Rimini are connected by pipeline to the city's
water intake structure on Tenmile Creek, providing direct access to untreated surface
water from the creek. EPA does not know the extent to and purpose for which residents use
this water, or whether the water is treated by individual users prior to use. Most other
-------
residences within the site have individual wells to extract groundwater for drinking water
purposes. Much of the groundwater within the immediate Rimini area is contaminated with
arsenic and metals from historic mining operations. Some of wells in the subdivisions at
the north end of the site appear to draw groundwater with slightly elevated arsenic
concentrations, probably naturally occurring. Many of the recreational cabins have wells.
Some of the cabins rely on local springs for water supply.
Future water use is expected to follow current trends. The City of Helena has implemented
voluntary water conservation measures that appear to be successful, although the
increasing number of connections are expected to result in increased overall city water
consumption over time. The city prefers to obtain as much of its water from the Tenmile
Water Treatment Plant system as possible because it is entirely gravity fed and is
relatively inexpensive to operate. Most new residential homes and recreational cabins in
the upper Tenmile Creek watershed are expected to rely on wells for potable water, except
for newly developed parcels in the immediate vicinity of Rimini that may be able to
connect to the proposed community water system.
-------
Section 7
Summary of Site Risks
EPA completed human health and ecological risk assessments for the site (CDM 2001d and
CDM 2001a, respectively), and summaries of those assessments are presented in this
section. Based on the assessments, EPA has determined that contaminants from historic
abandoned and inactive mining operations at the site are found in the site media at
concentrations that exceed acceptable risk levels. Key contaminants at the site are
arsenic, cadmium, copper, lead, and zinc.
7.1 Human Health Risks
The final HHRA (CDM 2001 d) quantitatively evaluated potential human health risks from
exposure to chemicals of potential concern (COPCs) associated with historical mining
activities. Potential exposures to COPCs in soil, groundwater, surface water, sediment,
interior dust, airborne particulates (i.e., respirable dust), and fish were evaluated and
discussed in detail in the HHRA. The following is a summary of the scope and findings of
that document, with a focus on the chemicals of concern (COCs) and the exposure pathways
that were identified as presenting a substantial threat to human health.
7.1.1 Media and Chemicals of Concern
COPCs in surface water, adit discharge, groundwater, waste rock/ tailings, surface soil
and sediment were quantitatively evaluated in the HHRA risk characterization using
standard methodologies. Of the original 17 COPCs, only four were carried through as COCs.
These COCs are presented in Table 7- 1 by appropriate media.
Table 7-1
Summary of Chemicals of Concern for Human Health
Chemical
Arsenic
Cadmium
Lead
Zinc
Surface Soil
/
/
Groundwater
/
/
/
Surface Water
/
/
/
/
Sediment
/
/
Note: Surface soil includes waste rock/tailings; surface water includes adit discharge.
7.1.2 Exposure Assessment
The site is comprised of several potential exposure units, corresponding to the watershed
subareas defined in the RI. Most full-year residents live in the Tenmile Creek Near Rimini
Subarea (most within the community of Rimini itself) or the Tenmile Creek Mainstem,
Subarea. In addition, a number of cabins are located on private in-holdings within the
Helena National Forest, mostly in the Tenmile Creek Near Rimini Subarea, that are used for
part-year recreational activities. Recreational use of the site by non- resident visitors
is common; activities include hunting, fishing, hiking, camping, biking, four-wheeling,
and snowmobiling. Currently, no industrial or commercial land use is found within the
site. Site workers are assumed to be associated with mine reclamation work or operation of
the Helena water system facilities.
HHRA exposure units, based on the site subareas, encompass large geographic areas. Since
the focus of the risk assessment was on development of risk-based PRGs for the entire
site, additional effort to define and evaluate exposure units on a smaller scale was not
considered necessary. Interpretation of risks and hazards within large exposure units is
discussed in detail in the HHRA.
-------
Based on current and potential future land uses for the site, the primary populations of
concern are residents (adults and children), recreational visitors, and workers. Complete
exposure pathways for these receptors are described in Table 7-2.
Table 7-2
Exposure Pathways Evaluated for Residents,
Workers, and Recreationists
Exposure Medium
Air (suspended
particulates)
Soil/Mine Waste
Interior Dust
Surface Water
(domestic purposes)
Surface Water
Groundwater
(domestic purposes)
Sediments
Residents
Inhalation
Incidental Ingestion
Incidental Ingestion
Ingestion
NA
Ingestion
NA
Workers
Inhalation
Incidental Ingestion
Incidental Ingestion
Ingestion
NA
Ingestion
NA
Recreationists
Inhalation
Incidental Ingestion
NA
NA
Incidental Ingestion
NA
Incidental
Exposure point concentrations (EPCs) were estimated for COCs for each medium using site
data from the RI citation. The EPCs were used to calculate estimated chemical-specific
chronic daily intake (GDI - the amount of chemical contacted per unit of body weight per
unit of time) by combining them with pathway-specific exposure assumptions, such as
freguency and duration of exposure. GDIs were estimated for each exposure pathway, and
separate risk calculations were performed for each exposure unit.
Exposure assumptions were based on regional or site-specific data, when available, or
selected from EPA default values. Regional exposure assumptions included estimates of
arsenic and lead bioavailability in soil and soil-to-indoor dust transfer for these two
contaminants. Assumptions are discussed in detail in the HHRA citation (CDM 2001d) .
Both reasonable maximum exposure (RME) and central tendency exposure (GTE) estimates of
risk were developed in the HHRA. To consider the full range of potential exposures at the
site, the 95th percentile of the entire data set was used to represent RME estimates and
the 95 percent upper confidence limit (UCL) of the arithmetic mean was used for the GTE
estimates. The RME uses EPA default parameters for bioavailability and soil-to-indoor dust
transfer, while the GTE uses conservative estimates for those factors taken from regional
data from the Butte and Anaconda mining sites. The PRGs are calculated using both the RME
and GTE, providing a range of PRGs that can be used to guide risk management decisions at
the Upper Tenmile site. Concentrations of the COCs by subarea are presented in Table 7-3.
A complete summary of the statistical analysis for all COPCs is presented in the HHRA.
7.1.3 Toxicity Assessment
The toxicity assessment evaluates the potential for each COG to cause adverse effects in
exposed individuals. Such effects are generally dependent on route of exposure (e.g.,
ingestion), duration and freguency of exposure, chemical concentration at the exposure
point, and sensitivity of exposed individuals. Adverse health effects may manifest after
exposure that is acute (exposure of a short duration, usually days to weeks), subchronic
(intermediate exposure period, usually months to a few years), or chronic (long-term
exposure, usually many years).
Chemical toxicological information is used to estimate toxicity criteria, which are
numerical expressions of the relationship between dose (exposure) and response (adverse
-------
Table 7-3
Summary Statistics for Chemicals of Concern for Human Health
Subarea
Upper Tenmile
Creek/
Vlonitor Creek
Banner Creek/
Ruby Creek
fenmile Creek
"-fear Rimini
Beaver Creek
Vtinnehaha Creek
Bear Gutch/
Walker Creek
fenmile Creek
Vlainstem
Statistic
Min.
Max
95%UCL
Court
Min.
Max
95%UCL
Court
Min.
Max
95%UCL
Court
Min.
Max
95%UCL
Court
Min.
Max
95%UCL
Court
Min.
Max
95%UCL
Court
Min.
Max
95% UCL
Court
Soil
Arsenic
(mg/kg)
4.5
77.4
45.8
11.0
3.1
7,759
1,782
16.0
13.9
18,935
3,130
62.0
13.3
2,203
1,199
8.0
—
-
-
—
-
-
-
—
15.2
534
594
3.0
Lead (mg/kg)
29.1
957
412.3
11.0
18.0
5,569
1,576
16.0
62.2
20,100
4,019
62.0
37.2
4,845
2,429
8.0
-
-
-
—
-
-
-
—
19.7
516
573
3.0
Waste Rock/
Tailings
Arsenic
(mg/kg)
3.7
93.0
72.1
18.0
31.7
726
312
23.0
13.9
121,000
16,217
101
2,245
6,699
5,515
10.0
41.0
4,356
1,250
22.0
81.6
108
-
2.0
2,539
3,861
3,812
4.0
Lead
(mg/kg)
35.9
51.9
53.8
3.0
22.7
3,748
1,118
36.0
32.1
48,700
4,908
101
235
13,971
9,628
11.0
19.9
22,968
8,330
29.0
59.0
452
419
4.0
1,765
2,410
2,404
4.0
Surface Water
Arsenic
(pg/L)
0.2
40.0
20.6
47.0
0.2
147
9.0
97.0
0.4
10,000
508
205
0.6
78.8
14.2
35.0
0.0
1,660
93.8
51.0
0.3
40.9
3.9
23.0
0.3
78.2
20.9
70.0
Cadmium
(Ag/L)
0.0
40.0
19.9
76.0
0.0
33.1
2.7
55.0
0.0
702.0
49.2
197
0.1
20.3
3.5
35.0
0.0
57.8
6.6
54.0
0.0
10.6
3.0
12.0
0.0
7.0
1.8
66.0
Lead (//g/L)
0.1
180
47.2
72.0
0.1
94.6
8.4
71.0
0.0
1,395
60.8
225
0.1
50.0
15.8
34.0
0.1
1,324
83.8
45.0
0.0
9.0
1.9
22.0
0.0
13.0
3.4
52.0
Zinc(Ag/L)
0.9
2,800
510
109
1.3
3,510
92.0
170
3.7
82,500
3,596
369
9.5
2,490
382
43.0
1.7
4,854
438
105
2.1
220.0
44.4
22.0
1.5
898
289
122
Adit Discharge
Arsenic (fjgIL)
0.2
25.1
13.8
6.0
0.2
416
43.9
31.0
0.1
27,700
457
51.0
1.5
659
307
10.0
0.2
396
152
8.0
1.1
12.8
14.1
3.0
-
-
-
-
Cadmium
(Ag/L)
1.3
3.6
4.5
3.0
0.0
19.0
6.1
21.0
0.2
724
188
33.0
12.2
114
114
8.0
0.0
1.3
1.4
3.0
0.1
8.1
9.0
3.0
-
-
-
-
Lead
(Ag/L)
0.1
123.0
78.3
18.0
0.1
35.1
6.5
28.0
0.1
2,150
210
47.0
0.2
454
237
10.0
1.3
10.4
7.9
6.0
0.3
8.2
9.1
3.0
-
-
-
-
Zinc (yUg/L)
5.0
1,390
915
17.0
5.0
2,390
541
32.0
4.8
93,500
21,574
44.0
1,660
13,600
5,898
10.0
5.0
95.5
60.5
8.0
7.8
121
134
3.0
-
-
-
-
Groundwater
Arsenic
(Ag/L)
1.4
8.2
8.2
5.0
4.6
207
106
6.0
1.2
3,490
170
43.0
67.6
67.6
-
1.0
19.5
19.5
-
1.0
0.3
6.7
-
2.0
0.2
77.0
25.5
21.0
Cadmium
(/vg/L)
0.0
19.5
11.5
12.0
0.2
4.3
1.9
6.0
0.0
237
30.8
37.0
0.5
0.5
-
1.0
2.7
2.7
-
1.0
0.3
0.5
-
2.0
0.0
1.3
0.5
11.0
Lead
(/vg/L)
0.6
80.0
39.5
14.0
1.7
34.0
21.2
6.0
0.0
2,460
280
29.0
0.5
0.5
-
1.0
8.3
8.3
-
1.0
0.1
80.2
-
20.0
0.0
5.1
2.2
17.0
Sediment
Arsenic
(Ag/L)
4.5
144
39.5
21.0
3.8
225
61.0
32.0
16.6
68,300
5,521
62.0
53.2
866
779
5.0
11.0
253
110
14.0
5.3
122
116
4.0
1.7
1880
502
35.0
Lead (//ig/L)
11.2
87.0
55.6
20.0
10.3
544
107
30.0
24.8
3,050
736
63.0
33.5
1,092
1,035
5.0
14.0
430
247
14.0
7.1
118
97.8
4.0
2.5
1,760
491
34.0
Notes:
Bold indicates the lower of the maximum and 95% UCL, which was used as the EPC for the CTE risk assessment.
UCL = upper confidence limit
EPC = exposure point concentration
Surface soilTable 7 -3.xls
-------
health effects) . Separate toxicity criteria are developed for assessment of carcinogenic
and systemic (noncancer) health effects. These toxicity criteria are used in conjunction
with estimates of exposure to quantify risks to exposed individuals.
7.1.3.1 Carcinogens
Toxicity criteria for carcinogens are provided as cancer slope factors (CSFs) in units of
milligrams of chemical per kilogram of body weight per day (mg/kg-day)-1 . These factors
are based on the assumptions that no threshold for carcinogenic effects exists and that
any dose is associated with some finite carcinogenic risk. Actual risks are unlikely to be
higher than those estimated using EPA CSFs, but they could be substantially lower. CSFs
for site COCs are presented in Table 7-4.
Table 7-4
Cancer Slope Factors for Chemicals of Concern
Chemical
Name
Arsenic
Cadmium
Lead
Cancer Class
Oral
A
Bl
B2
Inhalation
A
Bl
B2
Oral
CSF
(mg/kg-day) -1
1.50E+ 00
NA
NA
Reference
1
NA
NA
Inhalation
CSF
(mg/kg-day) -1
1.50E+ 00
6.30E+ 00
NA
Reference
1
1
NA
Notes:
C - carcinogen
CSF - cancer slope factor
I - IRIS (Integrated Risk Information
System)
NA - not available/not applicable
7.1.3.2 Noncarcinogens
Cancer Class:
A - Human carcinogen
Bl- Probable human carcinogen - limited human
data are available
B2 - Probable human carcinogen - indicates
sufficient evidence in animals
and inadequate or no evidence in humans
C - Possible human carcinogen
Toxicity criteria for noncarcinogens, or for significant systemic effects caused by
carcinogens, are provided as reference doses (RfDs) in units of mg/ kg- day. The RfD is an
estimate of the daily exposure to a chemical that could occur continuously over a lifetime
without adverse effects. RfDs may be interpreted as thresholds below which adverse effects
are not expected to occur, even in the most sensitive populations. Separate RfDs are often
developed by EPA for chemicals exhibiting systemic effects after oral and inhalation
exposure. RfDs for COCs are provided in Table 7-5.
-------
Table 7-5
Reference Doses for Chemicals of Concern
Chemical Name
Arsenic
Cadmium (Water)
Cadmium (Food)
Lead
Zinc
Target Organ
or System
CV/BL
GI/LV, KID
GI/LV, KID
CNS/PNS, KID
CV/BL, GI/LV
Oral
RfD
(mg/kg-day)
3.0E-04
5.0E-04
1. OE-03
IEUBK
3.0E-01
Reference
1
1
1
1
1
Inhalation
RfD
(mg/kg-day)
NA
NA
NA
NA
NA
Reference
NA
NA
NA
NA
NA
Notes: CV/BL =Cardiovascular/Blood I = IRIS (Integrated Risk Information System)
CNS/PNS =Central or peripheral nervous systems IEUBK = Integrated Exposure Uptake Biokinetic
model
GI/LV =Gastrointestinal or liver NA = not available/applicable
KID =Kidney
EPA has not published toxicity criteria for lead. As described in the HHRA, the Integrated
Exposure Uptake Biokinetic (IEUBK) model was used to evaluate risks to children from
exposure to lead in soil. The model estimates blood- lead levels for children using
default EPA assumptions, regional assumptions, and site specific data. These estimates are
compared to target blood- lead concentrations to assess possible risks. The IEUBK model is
intended for use in evaluating exposure in children up to the age of seven in a
residential setting. The HHRA did not assess lead in adults.
7.1.4 Risk Characterization
Risk characterization and hazard assessment for the site were focused on providing
order-of-magnitude estimates for relatively large subareas. Both RME and CTE estimates
were calculated to define a range of possible human health risks at the site. Therefore,
interpretation of risk and hazard estimates cannot be directly applied to any given mining
site or other smaller areas with significant historical mine waste.
7.1.4.1 Risk Calculation
For carcinogens, risk is generally expressed as the incremental probability of an
individual developing cancer over a lifetime as a result of exposure to the carcinogen.
Excess lifetime cancer risk is calculated from the following eguation:
Risk = GDI X CSF
where: Risk = a unitless probability of an individual developing cancer
GDI = chronic daily intake average over 70 years (mg/kg-day)
CSF = cancer slope factor, expressed as (mg/kg-day)-1
These risks are probabilities typically expressed in scientific notation (e.g., 1x10-6 or
l.OE-06). An excess lifetime cancer risk of 1x10-6 indicates that an individual
experiencing the assumed exposure estimate has a 1 in 1,000,000 chance of developing
cancer as a result of site-related exposure. This "excess lifetime cancer risk" is in
addition to risks of cancer an individual would face from other causes, such as smoking or
sun exposure. The chance of an individual developing cancer from all other causes has been
estimated to be as high as one in three. EPA's generally acceptable range for excess
cancer risk due to site related exposures (i.e., risk management range) is 10-4 to 10-6.
At the Upper Tenmile site, arsenic is the only known human carcinogen. Cadmium is a
probable human carcinogen, but its primary exposure route (inhalation) is not considered
-------
significant at this site. Thus, all cancer risk estimates are based on potential exposure
to arsenic.
The potential for noncarcinogenic effects is evaluated by comparing an exposure level over
a specified time period (e.g., a lifetime) with a RfD derived for a similar exposure
period. A RfD represents a level that an individual may be exposed to that is not expected
to cause any deleterious effect. The ratio of the exposure to toxicity is called a hazard
guotient (HQ). An HQ less than 1.0 indicates that a receptor's dose of a single
contaminant is less than the RfD, and that toxic noncarcinogenic effects from that
chemical are unlikely.
The HQ is calculated as follows:
HQ = CDI/RfD
where: GDI = chronic daily intake
RfD = reference dose
GDI and RfD are expressed in the same units and represent the same exposure period (i.e.,
chronic, subchronic, or short-term).
The hazard index (HI) is calculated by adding HQs for all COCs to which an individual may
reasonably be exposed that affect the same target organ or that act through the same
mechanism within a medium or across all media. An HI less than 1.0 indicates that, based
on the sum of HQs from different contaminants and exposure routes, toxic noncarcinogenic
effects are unlikely. An HI greater than 1.0 indicates that site-related exposures may
present a risk to human health.
7.1.4.2 Summary of Cancer and Noncancer Results
In general, estimated cancer risks are generally higher within the Tenmile Creek Near
Rimini Subarea (including the community of Rimini) than in the six other subareas. Risks
for recreational users are significantly lower than those for other users. In most
subareas, exceedances of EPA's acceptable range for recreational users are relatively
small.
The highest risks (both cancer and noncancer) for all user groups are generally associated
with incidental ingestion of waste rock by residents from the Tenmile Creek Near Rimini
Subarea. Risk estimates for the Tenmile Creek Near Rimini Subarea and the remaining
subareas are summarized for each user group (residents, workers, recreationalists) in the
following text and in Tables 7-6, 7-7, and 7-8, respectively.
Risks to Residents
• RME vs CTE. The more conservative RME estimates exceed EPA's acceptable range for
excess cancers in 23 of 30 instances, with a maximum risk estimate of 3.42x10-2
(waste rock). CTE estimates, which are more likely to be representative of actual
risk, exceed EPA's acceptable range in 10 of 30 instances, with a maximum of 1.89
xlO-3 (waste rock). For noncancer risks, the RME estimates are excessive (> 1.0) in
21 of 30 instances vs. 16 of 30 instances for CTE estimates. The maximum noncancer
risk using RME was 180, while the maximum noncancer risk using CTE was 33.6, both
for waste rock.
• Significant Pathways. Using the RME estimates, three ingestion pathways (waste rock,
soil, and groundwater) exceed EPA's acceptable range for excess cancer risk in every
instance where data are available. Excess cancer risks for surface water ingestion
exceed the acceptable range only slightly less freguently. In general, these trends
are also seen in the noncancer risks. Risks for air inhalation are acceptable in all
subareas for both cancer and noncancer risks. The highest residential risks (cancer
and noncancer) are associated with the ingestion of waste rock pathway.
-------
Table 7-6
Summary of Site-Related Lifetime Risk Estimates - Residents
Exposure Pathway
Cancer Risk
RME
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
Total Excess Cancer Risk by Subarea
CTE
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
Total Excess Cancer Risk by Subarea
Noncancer Hazard Indices
RME
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
CTE
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
Subarea
Tenmile
Creek Near
Rimini
3.42E-02
1 .09E-03
9.10E-06
6.50E-03
1.22E-02
5.40E-02
1 .89E-03
6.03E-05
1.51E-06
8.02E-04
1.51E-03
4.26E-03
1.80E+02
6.20E+00
5.77E-05
4.73E+01
7.81 E+01
3.36E+01
1.23E+00
3.18E-05
1.70E+01
3.27E+01
Beaver
Creek
8.59E-03
3.43E-03
3.68E-06
4.39E-04
1.90E-03
1.44E-02
4.73E-04
1.89E-04
6.09E-07
5.42E-05
2.34E-04
9.52E-04
4.52E+01
1.89E+01
6.52E-05
3.52E+00
1.00E+01
8.43E+00
3.69E+00
3.59E-05
1.37E+00
4.13E+00
Minnehaha
Creek
1.95E-03
5.25E-04
5.63E-07
5.99E-04
-
3.07E-03
1.07E-04
2.89E-05
9.36E-08
7.38E-04
-
2.10E-04
1.21 E+01
3.10E+00
2.28E-05
4.44E+00
-
2.59E+00
6.29E-01
1 .25E-05
1.67E+00
-
Tenmile Creek
Mainstem
6.17E-03
8.32E-04
8.92E-07
1.71E-03
7.17E-04
9.43E-03
3.32E-04
4.59E-05
1 .48E-07
2.14E-04
8.85E-05
6.80E-04
3.19E+01
4.37E+00
2.28E-05
9.56E+00
5.47E+00
5.99E+00
8.14E-01
1 .25E-05
3.87E+00
2.25E+00
Upper
Tenmile Creek/
Monitor Creek
1.41E-04
-
7.65E-08
9.63E-05
2.31 E-04
4.68E-04
7.77E-06
-
1 .43E-08
1.19E-05
2.84E-05
4.81 E-05
8.86E-01
-
6.55E-05
4.72E+00
3.18E+00
1.91E-01
-
3.61 E-05
1.45E+00
1.34E+00
Bear
Gulch/
Walker
Creek
1.68E-04
-
-
1.72E-04
1.88E-04
5.29E-04
9.27E-06
-
-
2.12E-05
2.32E-05
5.37E-05
9.14E-01
-
-
1.86E+00
1.16E+00
1.75E-01
-
-
7.13E-01
4.77E-01
Banner
Creek/
Ruby
Creek
2.21 E-03
1.08E-04
2.97E-06
2.45E-04
-
2.57E-03
1.22E-04
5.97E-06
4.93E-07
3.02E-05
-
1.59E-04
1.30E+01
7.57E-01
5.43E-05
2.20E+00
-
2.67E+00
1.74E-01
2.99E-05
8.33E-01
-
RME = reasonable maximum exposure CTE = central tendency exposure
* Drinking water exposure
Risks are based on arsenic
Bold indicates the value exceeds EPA's 10-4 to 10-6 acceptable range for excess cancer risks or has a hazard index greater than 1.0.
Table 7-6.xls Tbl ES-1 -all areas
-------
Table 7-7
Summary of Site-Related Lifetime Risk Estimates - Workers
Exposure Pathway
Cancer Risk
RME
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
Total Excess Cancer Risk by
CTE
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
Total Excess Cancer Risk bv
Noncancer Hazard Indices
RME
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
CTE
Water rock - ingestion
Surface soil - ingestion
Air - inhalation
Surface water - ingestion
Groundwater - ingestion*
Subarea
Tenmile
Creek Near
Rimini
7.50E-03
2.40E-04
6.61 E-06
2.72E-03
5.12E-03
1.56E-02
4.45E-04
1 .42E-05
8.23E-07
3.82E-04
7.20E-04
1.56E-03
4.75E+01
1.66E+00
5.03E-05
2.07E+01
3.88E+01
1.09E+01
4.08E-01
2.37E-05
7.42E+00
2.13E+01
Beaver
Creek
1.88E-03
7.52E-04
2.68E-06
1.84E-04
7.94E-04
3.62E-03
1.12E-04
4.47E-05
3.33E-07
2.58E-05
1.12E-04
2.95E-04
1.19E+01
5.06E+00
5.68E-05
-
4.98E+00
2.85E+00
1.25E+00
2.68E-05
6.47E-01
2.69E+00
Minnehaha
Creek
4.27E-04
1.15E-04
4.11E-07
2.50E-04
-
7.92E-04
2.53E-05
6.84E-06
5.12E-08
3.52E-05
-
6.74E-05
3.31 E+00
8.31 E-01
1 .98E-05
2.04E+00
-
9.53E-01
3.77E-01
9.36E-06
7.56E-01
-
Tenmile
Creek
Mainstem
1.32E-03
1.82E-04
6.50E-07
7.14E-04
3.00E-04
2.52E-03
7.83E-05
1 .08E-05
8.09E-08
1.01E-04
4.22E-05
2.32E-04
8.43E+00
1.15E+00
1 .98E-05
4.72E+00
1.90E+00
1.96E+00
2.69E-01
9.36E-06
1.57E+00
1.47E+00
Upper
Tenmile Creek/
Monitor Creek
3.09E-05
-
6.28E-08
4.02E-05
9.64E-05
1.68E-04
1 .83E-06
-
7.83E-09
5.67E-06
1 .36E-05
2.11E-05
2.43E-01
-
5.70E-05
1.76E+00
1.16E+00
6.65E-02
-
2.69E-05
8.87E-01
8.70E-01
Bear
Gulch/
Walker
Creek
3.69E-05
-
-
7.20E-05
7.86E-05
1.88E-04
2.19E-06
-
-
1.01E-05
1.11E-05
2.34E-05
2.43E-01
-
-
8.69E-01
5.26E+01
6.30E-02
-
-
3.68E-01
3.11E-01
Banner
Creek/
Ruby
Creek
4.84E-04
2.37E-05
2.17E-06
1 .OOE-04
-
6.10E-04
2.88E-05
1.41 E-06
2.70E-07
1 .44E-05
-
4.49E-05
3.52E+00
2.11E-01
4.73E-05
1.02E+00
-
8.95E-01
3.75E-01
2.23E-05
4.05E-01
-
RME = reasonable maximum exposure
"Drinking water exposure
Risks are based on arsenic
Bold indicates the value exceeds EPA's 10-4 to
CTE = central tendancy exposure
10-6 acceptable range for excess cancer risks or has a hazard index greater than 1.0.
Table 7-7.xls Workers
-------
Table 7-8
Summary of Site-Related Lifetime Risk Estimates - Recreationists
Exposure Pathway
Cancer Risk
RME
Water rock - ingestion
Surface soil - ingestion
Adit discharge - inhalation
Air - inhalation
Sediment - ingestion
Surface water - ingestion*
Total Excess Cancer Risk by
CTE
Water rock - ingestion
Surface soil - ingestion
Adit discharge- ingestion
Air - inhalation
Sediment - ingestion
Surface water - ingestion*
Total Excess Cancer Risk by
Noncancer Hazard Indices
RME
Water rock - ingestion
Surface soil - ingestion
Adit discharge - ingestion
Air - inhalation
Sediment - ingestion
Surface water - ingestion*
CTE
Water rock - ingestion
Surface soil - ingestion
Adit discharge - ingestion
Air - inhalation
Sediment - ingestion
Surface water - ingestion*
Subarea
Tenmile
Creek Near
Rimini
3.04E-03
9.72E-05
2.72E-03
7.04E-07
9.35E-04
2.27E-05
6.72E-03
1.53E-04
-
2.04E-04
2.98E-08
2.34E-05
1 JOE-06
3.82E-04
1.61E+01
5.62E-01
1.43E+01
4.46E-06
4.91 E+00
1.44E-01
1 .95E+01
6.70E-01
3.59E+00
6.30E-07
4.13E-01
Beaver
Creek
7.64E-04
3.05E-04
3.01 E-05
2.85E-07
9.23E-05
1 .53E-06
1.19E-03
3.38E-05
1 .53E-05
2.26E-06
1.21E-08
2.31 E-06
1.15E-07
5.83E-05
4.04E+00
1.71 E+00
1.79E-01
5.04E-06
5.71 E-01
1.17E-02
4.89E+00
2.05E+00
4.67E-02
7.12E-07
5.24E-02
Minnehaha
Creek
1.73E-04
4.67E-05
3.89E-05
4.38E-08
1.17E-05
2.09E-06
2.72E-04
8.68E-06
2.34E-06
2.91 E-06
1 .86E-09
2.93E-07
1.57E-07
1 .44E-05
1.12E+00
2.81 E-01
2.08E-01
1 J6E-06
8.66E-02
1 .42E-02
1.31 E+00
3.33E-01
5.21 E-02
2.49E-07
8.55E-03
Tenmile
Creek
Mainstem
5.35E-04
7.40E-05
1.27E-07
6.92E-08
2.02E-04
5.96E-06
8.17E-04
2.68E-05
3.71 E-06
9.57E-09
2.93E-09
5.07E-06
4.47E-07
3.61 E-05
2.85E+00
3.90E-01
1 .06E-02
1 J6E-06
1.06E+00
3.28E-02
3.45E+00
4.71 E-01
2.64E-04
2.49E-07
8.91 E-02
Upper
Tenmile Creek/
Monitor Creek
1 .25E-05
-
2.46E-06
6.69E-09
4.21 E-06
3.36E-07
1 .95E-05
6.29E-07
-
1 .85E-07
6.49E-11
1 .06E-07
2.52E-08
9.44E-07
8.21 E-02
-
1 JOE-02
5.06E-06
2. 41 E-02
1 .23E-02
9.58E-02
-
4.37E-03
7.15E-07
2.12E-03
Bear
Gulch/
Walker
Creek
1 .50E-05
-
1 .26E-06
-
1 .30E-05
6.01 E-07
2.98E-05
7.50E-07
-
9.42E-08
-
3.26E-07
4.51 E-08
1.22E-06
8.21 E-02
-
1 J8E-02
-
7.49E-02
6.05E-03
9.89E-02
-
4.75E-03
-
6.64E-03
Banner
Creek/
Ruby
Creek
1.97E-04
9.64E-06
5.64E-06
2.30E-07
7.80E-06
8.56E-07
2.20E-04
9.86E-06
4.83E-07
4.23E-07
9.77E-09
1 .96E-07
6.42E-08
1.10E-05
1.19E+00
7.15E-02
3.33E-02
4.20E-06
4.45E-02
7.07E-03
1.41 E+00
8.18E-02
8.62E-03
5.93E-07
3.92E-03
RME = reasonable maximum exposure
* Drinking water exposure
Risks are based on arsenic
Bold indicates the value exceeds EPA's 10-4 to 10-6 acceptable range for excess cancer risks or has a hazard index greater than 1.0.
CTE = central tendency exposure
Table 7-8.xls TBL ES -all areas
-------
• Subareas. Estimated risks (cancer and noncancer) for residents are most excessive,
in terms of frequency and magnitude, in the Tenmile Creek Near Rimini Subarea. The
lowest residential risks are found in the Upper Tenmile Creek/Monitor Creek and Bear
Gulch/Walker Creek Subareas.
Risks to Workers
• RME vs CTE. The RME estimates exceed EPA's acceptable range for excess cancers in 16
of 30 instances, with a maximum risk estimate of 7.50x10-3 (waste rock). CTE
estimates exceed EPA's acceptable range in 5 of 30 instances, with a maximum of
7.20x10-4 (groundwater). For noncancer risks, the RME estimates are excessive (>1.0)
in 15 of 30 instances vs. 9 of 30 instances for CTE estimates. The maximum noncancer
RME was 47.5 (waste rock) vs. a CTE of 21.3 (groundwater).
• Significant Pathways. As with residential risk, the highest level of worker risk
(cancer and noncancer) is associated with the ingestion of waste rock pathway. Using
the RME estimates, risk for incidental ingestion of waste rock exceeds EPA's
acceptable range for excess cancer risk in five of seven subareas. Risks for
ingestion of groundwater and surface water are less than those for waste rock, and
they are roughly an order of magnitude higher (10-3) in the Tenmile Creek Near
Rimini Subarea than the remaining subareas. Risks for all ingestion pathways are
unacceptable in most subareas for RME and are slightly less for CTE. In general,
these trends are also seen in the noncancer risks. As with residential users, risks
for air inhalation are acceptable in all subareas for both cancer and noncancer
risks using either RME or CTE.
• Subareas. As with residents, estimated risks (cancer and noncancer) for workers are
most excessive, in terms of frequency and magnitude, in the Tenmile Creek Near
Rimini Subarea followed by the Beaver Creek Subarea. The lowest risks are found in
the Bear Gulch/Walker Creek Subarea, followed closely by Upper Tenmile Creek/
Monitor Creek and Banner Creek/Ruby Creek Subareas.
Risks to Recreationists
• RME vs CTE. RME estimates exceed EPA's acceptable range for excess cancer risk in 9
of 39 instances, with a maximum value of 3.04x10-3 (waste rock). CTE estimates
exceed EPA's acceptable range in only 2 of 39 instances, with a maximum of 2.04 x
10-4 (adit discharge). For noncancer risks, the RME estimates exceed 1.0 in 9 of 39
instances vs. 7 of 39 instances for CTE estimates. The maximum noncancer RME was
16.1x1 , while the maximum noncancer CTE was 19.5, both waste rock.
• Significant Pathways. As with the other user groups, the RME risk estimates indicate
that incidental ingestion of waste rock is the pathway that most frequently exceeds
EPA's acceptable range for excess cancer risk (5 of 7 subareas). Risks associated
with air inhalation and surface water ingestion are acceptable in all subareas, and
all other pathways have only one to two exceedances. This trend is also seen in the
noncancer risk estimates. The highest residential risks (cancer and noncancer) are
associated with the ingestion of waste rock pathway.
• Subareas. As with residents and workers, estimated risks (cancer and noncancer) for
recreational users are most excessive, in terms of frequency and magnitude, in the
Tenmile Creek Near Rimini Subarea. The lowest risks are again associated with the
Upper Tenmile Creek/Monitor Creek and Bear Gulch/Walker Creek Subareas, which had no
unacceptable risks for recreational users.
Elevated cancer risks for surface soil and waste rock suggest that frequent contact with
these materials may present unacceptable levels of risk. However, actual current or future
risk is dependent on the location of wastes, land ownership, and other local conditions.
Actual risks for individual waste sources cannot be discerned readily from risk estimates
based on data pooled from relatively large regions within the upper Tenmile Creek
watershed. Risk estimates for exposure to other media (air, surface water, and
-------
groundwater) are likely to be more representative of actual risks throughout the site,
since exposures are not as location specific. For instance, dust blown from waste piles
can be carried to people living, working, or recreating in their general vicinity, even if
people do not actually freguent source areas. Similarly, surface water guality data are
likely to represent stream reaches rather than individual points along streams.
Exposures and risks within the Tenmile Creek Near Rimini Subarea, which includes the
community of Rimini, are of particular concern because:
• Data were collected during the RI specifically to provide a more complete
characterization of possible exposure concentrations in this subarea.
• Waste materials may have been redistributed in this subarea by human activities
(e.g., use of waste materials for fill).
• Human activity and potential for human contact with waste materials is probably
greatest in this area.
7.1.4.3 Estimates for Lead Impacts
EPA has established a goal of no more than 5 percent of children potentially having blood
lead levels greater than 10 micrograms per deciliter (ug/dL). Conservative estimates
(i.e., using default rather than more site-specific assumptions and exposure point data
from waste piles rather than yards) indicate that in all subareas, many children exposed
to lead would have a high probability of having blood lead levels greater than 10 ug/dL.
Generally, high blood lead levels are predicted for all residential areas where soil lead
concentrations exceed 950 milligrams per kilogram (mg/kg). Unacceptable lead exposure is
likely only when children contact contaminated media on a daily or almost daily basis.
Results also suggest that children who drink contaminated surface water and groundwater
may have a high probability of having blood lead levels greater than 10 ug/dL. This
conclusion holds true for all subareas. Again, the potential for lead exposures would be
greatest in the Rimini area.
7.1.4.4 Risk Characterization Uncertainty
Uncertainties are inherent in the estimation of potential risks, as guantitative risk
estimates are based on site-specific information, national default assumptions,
toxicologic literature and professional judgment. Uncertainties exist with all of these
sources. Uncertainties evaluated and discussed in the HHRA include the following:
• Biased Sampling Locations. Locations are biased due to a focus on the small fraction
of land within the site that contains mining wastes; however, EPA considers this
bias appropriate for developing conservative estimates of potential overall risks
from exposure at impacted mining sites. The primary focus was to develop PRGs that
would be useful in determining appropriate remediation strategies for the mining
sites. Biases are highest for surface soils and waste rock/tailings.
• Exposure Units. Modified definitions of RME and CTE are used to address possible
concerns with the large exposure units and to allow use of regional exposure
information. Thus, RME and CTE risks are interpreted somewhat uniguely. RME-based
risks probably represent upper-bound or ceiling values that may overestimate maximum
risks at the site. CTE-based risks are probably more realistic estimates, although
they are conservative due to a of lack of site-specific data. The upper range risks
for the site may lie close to those using CTE assumptions, while "'average" risks
are probably lower.
• Acute Exposure to Arsenic. EPA has proposed an interim "subchronic RfD" for
evaluation of short-term exposure to arsenic. However, toxicity information is not
sufficient to determine if short-term exposures might result in arsenic-induced
-------
effects. Thus, setting remediation goals based on acute exposure is highly uncertain
and is not attempted in the HHRA.
• Bioavailability. Bioavailability is an important factor in exposure. Site-specific
bioavailability factors are not available, so regional estimates of arsenic and lead
bioavailability were used and these regional estimates may differ significantly from
site wastes.
• Default Exposure Assumptions. Default exposure assumptions and professional judgment
are used to estimate potential GDIs. Assumptions made were conservative (i.e.,
unlikely to underestimate possible exposures), but probably do not result in
substantial overestimation.
• Dust Loading Factor. The dust loading factor used in the assessment is based on wind
erosion. Human activities could greatly increase dust generation. Risk and hazards
could be somewhat underestimated by not adjusting dust loading to account for human
activity. However, such underestimation is probably not significant.
• Lack of Interior Dust Data. Historical data were not available to characterize
chemical concentrations in interior dust. Thus, an estimated transfer coefficient of
the contribution of exterior soil to chemical concentrations in interior dust was
used to estimate chemical concentrations in interior dust. Over-or underestimation
of the transfer coefficient could impact estimates of exposure and risk.
7.1.5 Human Health Risk Conclusions
The following conclusions can be drawn from the HHRA:
• COCs for the HHRA are arsenic, cadmium, lead, and zinc, and arsenic is the only
known human carcinogen among the COCs.
• RME-based risks are expected to represent upper-bound or ceiling values that may
overestimate maximum risks at the site. CTE-based risks are probably more realistic
estimates, although they are conservative due to a of lack site-specific data. The
upper range risks for the site may lie close to those using CTE assumptions, while
"average" risks are probably lower.
• Excess cancer risk estimates are generally an order of magnitude higher in the
Tenmile Creek Near Rimini Subarea than in other subareas. This area is of particular
concern because of the high potential for contact with human receptors and the
possibility of human redistribution of the contamination. Also, the accuracy of the
estimates is greater, because the area was the most aggressively sampled area.
• Incidental ingestion of waste rock is the pathway that most freguently exceeds EPA's
acceptable range for excess cancer risks. The magnitude of exceedance is also
greater for this pathway in most instances. This trend is also seen for noncancer
risks.
• Risks (cancer and noncancer) are elevated for potential future use of surface water
and groundwater for drinking water purposes by residents and workers. In addition,
risks for incidental ingestion of sediment and adit discharge water by
recreationists were elevated within the Tenmile Creek Near Rimini Subarea.
• In subareas other than Tenmile Creek Near Rimini, excess cancer risks from
recreational exposure are within or below EPA's acceptable range, and any
exceedances are relatively insignificant. Because the primary land use (both present
and future) of this land is likely to be mainly recreational, the actual excess
cancer risk for the majority of the site may be within, or only slightly above,
EPA's acceptable range.
-------
• Children exposed to lead in all subareas may have a high probability of having blood
lead levels greater than 10 ug/dL. Generally, high blood lead levels are predicted
for all areas where soil lead concentrations exceed 950 mg/kg. Even adult exposure
to lead in surface soils and waste piles could be significant if exposure is
chronic. Children in all subareas who might drink contaminated surface water and
groundwater may also have a high probability of unacceptably high blood lead levels.
• Although many uncertainties are associated with the risk estimates, these estimates
are expected to be conservative.
7.2 Ecological Risks
Ecological risk assessment (ERA) is a process that evaluates the likelihood that adverse
ecological effects are occurring or may occur as a result of exposure to one or more
stressors. The ERA for the site was issued by EPA in April 2001 (CDM 2001a).
7.2.1 Chemicals of Concern
A total of 17 COPCs were identified in the ERA, based on several established criteria.
Table 7-9 lists the eight chemicals identified as COCs for surface water, sediment, and
soils.
Table 7-9
Summary of Chemicals of Concern for Ecological Risk
Chemical
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Zinc
Surface Soil
/
/
/
/
/
/
/
/
Surface Water
/
/
/
/
/
/
/
Sediment
/
/
/
/
/
/
/
Note: Surface soil includes waste rock; surface water includes adit discharge.
Although aluminum concentrations are elevated at several locations, it is not included in
the list of COCs because concentrations across the United States commonly exceed water
guality standards, but rarely pose a significant ecological risk. The exception is where
pH is significantly lower than naturally occurring conditions, as in areas impacted by
acid rain. Levels of pH at the site are not low enough to warrant the inclusion of
aluminum as a COG.
7.2.2 Exposure Assessment
The potential for the identified COCs to adversely affect ecological receptors is based on
concentration and the potential, frequency, and duration of exposure. For ecological
receptors, frequency and duration of exposure often cannot be quantified accurately.
Therefore, best professional judgment and information obtained from the literature are
often used to assess these exposure criteria.
-------
Table 7-10
Summary Statistics for Chemicals of Concern for Ecological Risk
coc
Upper Tenmile
Creek/
Monitor Creek
mean
Surface Water (|jg/L)
Arsenic
Cadmium
Copper
Iron
Lead
Manganese
Zinc
2.3
1.3
17.3
120
18.1
54.4
161
Sediment (mg/kg)
Arsenic
Cadmium
Copper
Iron
Lead
Manganese
Zinc
21.8
1.0
11.7
8120
45.6
408
114
max
18.4
6.9
140
709
180
269
700
144
1.6
28.9
13600
87.0
1140
345
U95
3.1
2.8
28.5
177
26.6
82.3
371
32.5
1.4
14.8
9480
53.8
543
160
Banner Creek/
Ruby Creek
mean
4.8
0.65
3.1
383
4.6
60
32
44.2
1.3
38.0
18564
71.0
861
189
Surface Soil & Other Solid Media (mg/kg)
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Zinc
55.3
5.6
9.1
35.7
11093
217
540
108
93.0
14.4
28.3
93.6
39620
957
1604
362
63.1
7.2
12.9
46.5
13454
351
763
139
533
6.0
9.0
143
30356
817
1087
286
max
21.5
8.1
81.7
10900
22.6
703.0
456
225
5.1
310
90000
544
2650
537
7759
31.5
18.1
595
111347
5569
3942
2065
U95
5.7
0.8
4.3
NA
5.6
130.0
40.0
59.7
1.6
54.1
22991
99.3
1079
224
912
8.6
11.3
197
36809
1090
1299
362
Beaver
Creek
mean
4.6
1.2
36.4
73.3
2.5
44.9
191
189
6.4
201
9137
382
2064
437
2219
5.8
20.7
233
33852
4088
764
308
max
19.8
10.9
210
200
3.7
397
2070
486
14.2
293
11900
991
3320
716
6699
14.3
52.0
600
66005
13971
1997
746
U95
5.9
1.8
52.8
94.7
NA
78.3
308
402
11.8
277
NA
836
3121
645
2975
8.2
28.8
320
40129
5725
980
392
Upper Tenmile
Creek
Near Rimini
mean
149
19.5
42.1
3028
15.6
726
2470
3532
16.9
125
35504
586
1842
2261
9022
52.0
9.6
165
38772
3613
2651
1433
max
7600
702
860
143000
379
30770
79860
68300
666
631
486000
3050
49000
68600
108204
620
38.8
1813
93570
20100
138322
82456
U95
NA
25.1
NA
NA
19.0
2261
4266
9114
14.6
224
43498
902
2081
2503
20029
70.0
12.1
182
40979
6405
NA
NA
Minnehaha
Creek
mean
38.0
3.2
30
1436
20.3
74.3
345
34.0
10.5
180
18013
140
792
1139
704
101
10.0
304
39676
5280
751
823
max
1660
57.8
660
75300
1324
93.4
4854
52.8
42.6
300
26500
340
1430
2850
4356
198
20.0
1514
61704
22968
1559
3350
U95
NA
3.8
NA
NA
50.3
1670
1081
40.0
17.7
221
21010
185
985
1606
1071
160
16.0
410
43497
7386
943
1064
Tenmile Creek
Mainstem
mean
19.2
1.1
4.9
86.4
0.9
38.8
202
369
6.8
97.2
32012
344
1123
945
1615
4.4
14.0
60.9
25783
1109
767
424
max
68.0
7.0
129
3670
7.0
942
898
1880
30.4
239
334000
1760
2940
3470
3861
5.0
16.2
91.2
35607
2220
922
879
U95
38.0
1.8
NA
161
1.1
NA
320
484
8.8
119
48735
460
1347
1195
2657
NA
15.7
70.9
29472
1627
846
624
Bear Gulch/
Walker Creek
mean
1.6
0.2
2.0
71.5
0.6
7.5
31.0
36
1.8
47.3
22725
42.8
1406
164
NA
-
-
187
46269
254
960
129
max
8.4
0.7
7.8
207
1.1
24.6
220
122
3.8
61.0
29800
118
3220
494
108
-
-
234
62646
452
1141
129
U95
2.6
0.3
3.2
103
0.9
11.0
49.0
78.0
2.8
55.6
28820
85.2
2386
312
NA
-
-
229
58523
396
1058
NA
Bold denoted the exposure point concentration (EPC— sually the UC95, unless the UC95>max, and/or max< calculated mean)
NA = UC95 is not applicable as EPC (see above)
EPC = exposure point concentration
Surface water data are dissolved.
— = no data
max = maximum detected value
Table 7-10.wpd
-------
7.2.2.1 Exposures Based on COC Concentration
The 95 percent UCL of the arithmetic mean is often used to represent a RME. Complete
summaries of concentration data for all COPCs are presented in the ERA. Table 7- 10
presents the minimum, maximum, and 95 percent UCL concentrations for the eight COCs
relevant to risk characterization. The EPCs used in the assessment are identified in bold.
If available, the 95 percent UCL values were used for the EPC. Means and maximums were
used where 95 percent UCL values were considered inappropriate.
7.2.2.2 Exposures Based on Estimated Daily Dose
Ingestion of contaminated water and prey can also adversely affect ecological receptors.
At sites contaminated with mining-related metals, the ingestion exposure pathway is
generally of less concern than direct effects on aguatic biota. However, certain receptors
or receptor groups can be at substantial risk if sufficiently exposed to contaminated
water and prey. Generally, piscivorous and insectivorous predators are at most risk if the
COCs in surface water and sediments accumulate to a significant level in fish and aguatic
invertebrates. The ERA estimated dose-based risks to these receptors using belted
kingfisher, marsh wren, and mink. The input factors and resulting doses are detailed in
the ERA.
7.2.3 Ecological Effects Assessment
Published literature indicates that most of the COCs identified for this site have
substantial potential to adversely affect exposed ecological receptors. Several different
types of data are used to assess COC toxicity or the potential of COCs to cause adverse
effects in exposed receptors. These different types of data are used in a
weight-of-evidence approach to assess risk.
The weight-of-evidence approach for the ERA was based on multiple lines of evidence. One
was the HQ method, where comparisons are made between COC concentrations in various media,
and COC-and media-specific measurement endpoints that are applicable to representative
receptors. Other fines of evidence include guantitative and gualitative site-specific
information on key receptor groups, such as benthic macroinvertebrates, periphyton, and
fish.
Multiple effects concentrations (e.g., water guality criteria or other selected toxicity
reference values [TRVs]) from several sources were compiled for each media- specific COC.
Some of the evaluated data sources did not provide relevant effects data for certain COCs,
but in most cases several relevant TRVs were identified. A preferred TRV was selected from
these for each COC and media type. These TRVs specifically relate to key receptors,
receptor groups, or assessment endpoints. Tables 7-11, 7-12, and 7-13 present the TRVs for
COCs in surface water, sediment, and surface soil, respectively. The values presented in
each of these tables were considered for use as preferred TRVs in the ERA. Final or
preferred TRVs for the site were selected from the values presented in these tables.
TRVs for assessing risks to piscivorous and insectivorous birds and piscivorous mammals
were based on dose or concentration of COC ingested via exposure to the major surface
water COCs via drinking water and consumption of fish and aguatic invertebrates. The dose-
based TRVs are presented on Table 7-14.
7.2.4 Ecological Risk Characterization
This section summarizes guantitative risk estimates based on HQs and provides an
evaluation of risk based on other supporting studies or data. The evaluation was conducted
for each subarea of the site.
7.2.4.1 Quantitative Risk Estimates
-------
Table 7-11
Toxicity Reference Values for Surface Water Chemicals of Concern
coc
Arsenic
Cadmium
Copper
Iron
Lead
Manganese
Zinc
Surface Water Toxicity Reference Values (TRVs, u/L)
Chronic
AWQC1
150
0.097
4.1
1,000
0.9
NA
54
Secondary
Chronic
AWQC2
NA
NA
NA
NA
NA
120
NA
Lowest EC20
Fish3
2,130 (As III)
1,500 (As V)
1.8
5
NA
22
1,270
47
Lowest EC20
Daphnids 3
633 (As III)
>932 (As V)
0.75
0.205
NA
NA
<1,100
NA
Rainbow Trout
Chronic TRV4
2,953
2.3
20 estimated
NA
55
NA
285
Daphnid
Chronic TRV 5
914
0.6
4.2 estimated
NA
18.0
NA
42.1
1 Dissolved ambient water quality criteria (AWQC); standards for cadmium, copper, lead, and zinc are based on a hardness of the water (the values shown assume a hardness of 25
mg/LasCaCO3)
2 Alternative chronic AWQC (Suter and Tsao 1996)
3 Highest tested concentration causing less than 20% reduction in growth or reproductive endpoints (Suter and Tsao 1996)
4 Species-specific TRV (dissolved), adjusted to hardness of 40 mg/L, Clark Fork River Ecological Risk Assessment (EPA 1999) (Copper values based on Clark
Fork River site-specific toxicity studies)
5 Species-specific TRV (dissolved), adjusted to hardness of 40 mg/L, Clark Fork River Ecological Risk Assessment (EPA 1999) (Copper values based on revised
EPA database which resulted in chronic value for daphnids exceeding acute value at some hardness levels. Chronic value for copper therefore considered
unacceptable)
NA - Not available (no value established or derived)
Bold type indicates preferred TRV, used to derive HQs
mg/L = micrograms per liter
COC = chemical of concern
Table 7-1 Lwpd
-------
Table 7-12
Toxicity Reference Values for Sediment Chemicals of Concern
coc
Arsenic
Cadmium
Copper
Iron
Lead
Manganese
Zinc
Sediment Toxicity Reference Values (TRVs, mg/kg)
Ingersoll
NOAEL TRV 1
13
0.7
41
NA
53
NA
110
Ingersoll
LOAEL TRV 2
50
3.9
190
NA
99
NA
550
Regional
NOAEL TRV 3
115
4.93
1,125
NA
86.5
NA
1,385
Regional
LOAEL TRV 4
230
9.86
2,250
NA
173
NA
2,770
EPA ARCS
TEC5
12.1
0.592
28
NA
34.2
NA
159
EPA ARCS
PEC6
57
11.7
77.7
NA
396
NA
1,532
OMELEL7
6
0.6
16
20,000 (2%)
31
460
120
EPA
Region IV
SV9
7.24
1
18.7
NA
30.2
NA
124
1 No Observed Adverse Effect Level-based sediment TRV (Effects Range-Low or ERL) derived by Ingersoll et al. (1996)
2 Lowest Observed Adverse Effect Level-based sediment TRV (Effects Range-Median or ERM) derived by Ingersoll et al. (1996)
3 NOAEL-based sediment TRV using the results of Hyalella toxicity tests, from the Clark Fork River ERA (EPA 1999b)
4 LOAEL-based sediment TRV using the results of Hyalella toxicity tests, from the Clark Fork River ERA (EPA 1999b)
5 Threshold effects Concentration (TEC), Assessment and Remediation of Contaminated Sediments Program (ARCS) (EPA 1996 in Jones, Suter, and Hull 1997)
6 Probable effects concentration (PEC), Assessment and Remediation of Contaminated Sediments Program (EPA 1996 in Jones, Suter, and Hull 1997)
7 Ontario Ministry of Environment Lowest Effect Level (Persaud et al. 1993)
8 Ontario Ministry of Environment Open Water Disposal Guideline (Persaud et al. 1993)
9 EPA Region IV Screening Value (EPA Region IV 1995 in Jones, Suter, and Hull 1997)
NA - Not available (no value established or derived)
Bold type indicates preferred TRV, used to derive HQs
COC = chemical of concern
Table 7-12.wpd
-------
Table 7-13
Toxicity Reference Values for Surface Soil Chemicals of Concern
coc
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Zinc
Surface Soil Toxicity Reference Values (TRVs, mg/kg)
Phyotoxicity TRV
1
136-315
5.1-2.0
-
236-750
-
92-250
-
-
196-240
2
224-315
8.6-40
-
1 ,062-
1,636
-
179-250
-
-
379-500
3
100
100
-
100
-
1,000
-
5
500
4
10
4
-
100
-
50
-
35
50
5
200
5
-
400
-
-
-
-
6
15-50
3-5
-
60-125
-
100-400
-
-
70-400
Earthworm TRV 7
60
20
0.4
50
-
500
-
0.1
200
Microorganism
TRV7
100
20
10
100
50
900
100
30
100
Interim
Remediation
Criteria
(agricultural
use)8
20
3
750
150
-
375
-
0.8
600
1CDM 1997(pH<6.5)
2 COM 1997(pH>6.5)
3CH2MHill 1987aand 1987b
4 Efroymson, Will, Suter, and Wooten 1997
5 Rice and Ray 1984
6 Kabata-Pendias and Pendias 1992
7 Efroymson, Will, and Suter 1997
8 Canadian Council of Ministers of the Environment (CCME) 1991
Bold type indicates preferred TRV, used to derive HQs
COC = chemical of concern
Table 7-1 S.wpd
-------
Table 7-14
Toxicity Reference Values for Piscivorous and Insectivorous Birds and Piscivorous Mammals
(Major Surface Water Chemicals of Concern)
uuu
Cadmium
Copper
Lead
Zinc
Belted Kingfisher
Dose (mg/kg-d)
0.68
(mallard and
chicken -
reported 200
mg/kg diet)
6.0
(great blue heron
and American
kestrel)
1.32
(American
robin)
39
(great blue heron
and American
kestrel)
Effect
Dietary NOAEC
for birds and
other wildlife
Estimated
dietary + water
NOAEL
Estimated
dietary + water
NOAEL
Estimated
dietary + water
NOAEL
Reference
Eisler1985
Clark Fork
River ERA,
EPA 1999
Clark Fork
River ERA,
EPA 1999
Clark Fork
River ERA,
EPA 1999
Marsh Wren
Dose (mg/kg-d)
0.13
(American
robin)
6.0
(American
robin)
1.32
(American
robin)
39
(American
robin)
Effect
Estimated
dietary + water
NOAEL
Estimated
dietary + water
NOAEL
Estimated
dietary + water
NOAEL
Estimated
dietary + water
NOAEL
Reference
Clark Fork
River ERA,
EPA 1999
Clark Fork
River ERA,
EPA 1999
Clark Fork
River ERA,
EPA 1999
Clark Fork
River ERA,
EPA 1999
Mink
Dose (mg/kg-d)
0.028
(mink- reported
200 mg/kg diet)
3.6
(mink - estimated
from21-d LD50,
35.7 mg/kg-d,
from reported
5.0 mg/kg BW,
single dose)
0.32
(dog)
470
(mink)
Effect
Dietary
NOAEC1 for
birds and other
wildlife
Estimated
chronic
threshold from
LD50/10
Chronic
Toxicity Level
Estimated
dietary + water
NOAEL
Reference
Eisler1985
Aulerich et al.
1982
Demayo et al.
1982 in Eisler
1988
Clark Fork
River ERA,
EPA1999b
Note:
NOAEC = No observed adverse effects concentration
NOAEL = No observed adverse effects level
LD50 = lethal dose to 50 percent
COC = chemical of concern
Table 7-14.wpd
-------
Table 7-15 shows all HQs greater than 1.0 for COCs in surface water, sediment, and surface
soil, respectively. HQs less than 1.0, indicating low or insignificant risk, are not
shown. Table 7-16 summarizes the estimated risks for representative piscivorous mammalian
(mink) and piscivorous/insectivorous avian (belted kingfisher/marsh wren) predators. These
risk estimates are based on total daily doses (diet + water) divided by appropriate TRVs.
This calculation is analogous to the HQ approach. The data presented on these tables are
summarized below, by exposure media and for each of the seven subareas.
The HQ data reveal that the major contributors to ecological risk for surface water are
cadmium, copper, and zinc. Arsenic, cadmium, lead, manganese, and zinc are major COCs for
sediments. Major COCs for surface soils include arsenic, chromium, iron, lead, manganese,
mercury, and zinc.
The identification of major COCs is not intended to minimize the importance of potential
toxicity of other COCs with HQs greater than 1.0, but rather is to focus the risk
assessment on the primary contributors to adverse ecological effects. The major COCs
include those chemicals that are most toxic and are most widely distributed throughout the
site. The major COCs also have been detected at higher concentrations than nonmajor COCs,
relative to ecotoxicity benchmarks, thresholds, or criteria.
Remedial actions will reduce ecological risks by removing or reducing concentrations of
major COCs in site media. Remedial actions also concurrently will remove or reduce
concentrations of other COCs associated with the contaminant source materials, further
reducing ecological risks from nonmajor COCs. The major COCs will serve as indicator
chemicals for monitoring remedial success.
7.2.4.2 Flow-Related Effects
The ERA focused on assessing the impacts of chemical contamination, primarily mining
related, on aguatic and terrestrial receptors. However, the dewatering of Tenmile Creek
below Rimini for much of the year is also an important stressor for aguatic biota. Since
this reach is highly contaminated with a variety of toxic metals, low stream flow and the
lack of water for extended periods of time exacerbate water guality degradation during or
near these periods.
Additional flow in Tenmile Creek during base flow is necessary to maintain water guality
improvements in the creek. DFWP estimates that additions of flow up to approximately 3 to
4 cfs would allow a distribution of all age classes of fish in reaches previously
determined to be lethal to fry and older fish.
7.2.4.4 EPA Site-Specific Toxicity Studies
EPA conducted flow-through aguatic toxicity tests with Tenmile Creek waters in August 2001
using the EPA Region VIII Mobile Bioassay Laboratory. The purpose of these tests was to
evaluate the acute toxicity of Tenmile Creek water on young rainbow trout, considered
representative of sensitive aguatic receptors at this site.
The test methods and results are detailed in the ERA. In brief, they included 48-hour flow
through tests using surface water from three sites (High, Low, and Control). Mean lethal
concentrations to 50 percent of test organisms (LC50) were determined for High and Low
site exposures. For dissolved zinc, the mean Low site LC50 corresponds to an estimated
dissolved zinc concentration of 454.5 jlg/L, and the mean site LC50 corresponds to a zinc
concentration of 1,086 ]lg/L.
DFWP also conducted caged fish studies in Tenmile Creek in 1999 and 2000. Those results
are presented in the ERA and confirm the greater sensitivity of rainbow trout to dissolved
zinc compared to brook trout. Significant short term mortality as well as chronic effects
in rainbow trout may be expected at concentrations at or exceeding about 455-475 jlg/L.
-------
Table 7-15
Hazard Quotients for Chemicals of Concern in Surface Water, Sediment, and Soil
coc
Upper Tenmile
Creek/Monitor Creek
Banner Creek/
Ruby Creek
Beaver Creek
Upper Tenmile Creek
Near Rimini
Minnehaha
Creek
Tenmile Creek
Mainstem
Bear Gulch/
Walker Creek
Surface Water
Arsenic
Cadmium
Copper
Iron
Lead
Zinc
0.003
4.7
7.0
0.18
1.5
8.8
0.006
1.3
1.0
0.3(m) 10.9(M)
0.31
0.95
0.006
3.8
12.9
0.09
0.14(m) 0.12(M)
7.3
0.1 6(m) 8.3(M)
41.8
10.3(m) 210(M)
3.0(m) 143(M)
1.1
101
0.04(m) 1.8(M)
6.3
7.3(m) 161(M)
1.4(m) 75.3(M)
2.8
25.7
0.4
3.0
1.2(m) 31.5(M)
0.16
0.06
7.6
0.002
0.5
0.8
0.10
0.05
1.2
Sediment
Arsenic
Cadmium
Copper
Iron
Lead
Manganese
Zinc
0.7-2.5
0.4-2.0
0.1-0.4
0.5
0.5-1.0
1.2
0.3-1.5
1.2-4.6
0.4-2.3
0.3-1.3
1.1
1.0-1.9
2.3
0.4-2.2
8.0-31
3.0-17
1.5-6.8
0.5(m) 0.6(M)
8.4-16
6.8
1.2-5.9
182-701
3.7-21
1.2-5.5
2.2
9.1-17
4.5
4.6-23
0.8-3.1
4.5-25
1.2-5.4
1.1
1.9-3.5
2.1
2.9-15
9.7-37
2.3-13
0.6-2.9
2.4
4.6-8.7
2.9
2.2-11
1.6-8
0.7-4.0
0.3-1.4
1.4
0.9-1.6
5.2
0.6-2.8
Soils
Arsenic
Cadmium
Chromium
Copper
Iron
Manganese
Zinc
0.2-1.1
0.4-1.4
1.3-32
0.06-0.9
269
7.6
0.6-0.7
2.9-15
0.4-1.7
1.1-28
0.3-3.9
736
13
1.5-1.8
9.4-50
0.4-1.6
2.9-72
0.4-6.4
803
9.8
1.6-2.0
64-339
3.5-14
1.2-30
0.2-3.6
820
27(m) 138(M)
6.0-7.3(m) 344-421 (M)
3.4-18
8.0-31
1.6-40
0.5-8.2
870
9.4
4.4-5.4
8.4-44
0.2-0.9(m) 0.3-1. 0(M)
1.6-39
0.09-1.4
589
8.5
2.6-3.2
0.3-1. 8(M)
-
-
0.3-4.6
1170
11
0.5-0.7 (m&M)
Bold = HQ>1 (significant risk)
Unless otherwise noted, the HQ is calculated using the UC95 as the EPC.
m or M = mean or Maximum. These concentrations were used to calculate the HQ if the UC95 was not applicable (the UC95>max det and/or Max det< calculated mean [inc. ND])
A range of values indicates more than one TRV was used to generate the HQ. The range generally spans the no-effect to low-effect range.
Table 7-1 S.wpd
-------
Table 7-16
Estimated Risks (Hazard Quotients) for Representative Birds and Mammals
Species
coc
Upper Tenmile
Creek/ Monitor
Creek
Estimated
Dose
(mg/kg-d)
HQ
Banner Creek/
Ruby Creek
Estimated
Dose
(mg/kg-d)
HQ
Beaver Creek
Estimated
Dose
(mg/kg-d)
HQ
Tenmile Creek Near
Rimini
Estimated
Dose
(mg/kg-d)
HQ
Minnehaha
Creek
Estimated
Dose
(mg/kg-d)
HQ
Tenmile Creek
Mainstem
Estimated
Dose
(mg/kg-d)
HQ
Bear Gulch/
Walker Creek
Estimated
Dose
(mg/kg-d)
HQ
Mink
Copper
Cadmium
Lead
Zinc
0.0007
0.0001
0.0005
0.0037
<1
<1
<1
<1
0.0001
0.0001
0.0001
0.0007
<1
<1
<1
<1
0.0014
0.0001
0.0001
0.0044
<1
<1
<1
<1
0.0016
0.0016
0.0004
0.0571
<1
<1
<1
<1
0.0011
0.0003
0.0006
0.0080
<1
<1
<1
<1
0.0002
0.0001
<0.00001
0.0047
<1
<1
<1
<1
0.0001
<0.00001
O.00001
0.0007
<1
<1
<1
<1
Belted Kingfisher
Copper
Cadmium
Lead
Zinc
0.0163
0.0021
0.0087
0.0680
<1
<1
<1
<1
0.0029
0.001 1
0.0022
0.0135
<1
<1
<1
<1
0.0343
0.0020
0.0012
0.0806
<1
<1
<1
<1
0.0397
0.0319
0.0075
1 .0425
<1
<1
<1
<1
0.0283
0.0052
0.0097
0.1456
<1
<1
<1
<1
0.0046
0.0018
0.0004
0.0853
<1
<1
<1
<1
0.0019
0.0003
0.0003
0.0131
<1
<1
<1
<1
Marsh Wren
Copper
Cadmium
Lead
Zinc
0.3019
0.2018
1 .2589
8.5448
<1
1.6
<1
<1
0.0541
0.1009
0.3200
1.6984
<1
<1
<1
<1
0.6352
0.1863
0.1739
10.1370
<1
1.4
<1
<1
0.7346
3.0269
1 .0851
131.09
<1
23.3
<1
3.4
0.5235
0.4967
1.4120
18.31
<1
3.8
1.1
<1
0.0855
0.1707
0.0626
10.721
<1
1.3
<1
<1
0.0349
0.0310
0.0417
1.6453
<1
<1
<1
<1
Estimated doses are based on mean concentrations of dissolved COCs in surface water. HQ is calculated as estimated dose divided by TRV. TRVs are presented in Table 7-14.
COC = chemical of concern
HQ = hazard quotient
Table 7-16.wpd
-------
7.2.4.5 Specific Issues Related to Canada Lynx Exposures
The USFWS expressed concerns about potential Canada lynx (Lynx canadensis) exposures to
mining-related metals. Specifically, USFWS was concerned that Canada lynx may be exposed
to elevated levels of cadmium via a specific food chain involving willows (Salix spp.) and
consumers of willows, such as ptarmigan. Evidence suggests that concentrations of cadmium
could bioaccumulate in Ptarmigan (Lagopus leucurus) kidneys at levels 3000 times the soil
concentration.
These concerns were addressed in the ERA with the conclusion that cadmium in the Tenmile
Creek watershed terrestrial environment posed little or no risk to top predators, such as
red fox. The prey species of these predators are mostly herbivorous, and significant
accumulation of mining-related contaminants via the terrestrial plant- to- herbivore
pathway is not expected. To date areas having both elevated cadmium in soil and dense or
abundant willows have not been identified on site, and lynx are not expected to be at
significant risk from ingestion of cadmium-contaminated prey. In addition, there is no
evidence that conifers, grasses, and forbs, the likely preferred diet of snowshoe hares,
take up and concentrate cadmium to the same degree found in the willow study.
7.2.5 Ecological Risk Assessment Conclusions
The following conclusions were drawn from the ERA:
• Site surface waters, sediments, surface soils and other solids media, and sensitive
receptors associated with these media are currently being impacted by elevated
concentrations of metals. For aguatic environments, this is also supported by site-
specific studies using fish, benthic macroinvertebrates, and periphyton.
• Dissolved cadmium, copper, lead, and zinc are the most important stressors for
aguatic biota throughout most of the site, as represented by salmonid fish,
daphnids, benthic macroinvertebrates, and periphyton.
• Arsenic, cadmium, lead, manganese, and zinc in site sediments are the major
stressors for benthic invertebrates. These metals in sediment also probably
contribute to the cumulative toxicity experienced by fish and other aguatic biota.
Stream sediments also impair physical habitat, especially in depositional areas.
• For significant portions of the year, the very low flow or complete absence of water
in Tenmile Creek below Rimini is an important stressor for aguatic biota within that
portion of the site. DFWP has recommended maintaining a flow rate of up to
approximately 3 to 4 cfs in Tenmile Creek.
• Arsenic, chromium, iron, lead, manganese, mercury, and zinc in site surface soils
and other solids media are the major stressors for terrestrial organisms, as
represented by terrestrial plants and earthworms. There is more uncertainty with
risk estimates for iron, manganese, and possibly mercury than for the other soil
COCs because of toxicity data limitations.
• Piscivorous mammalian and piscivorous avian predators, represented by mink and
belted kingfisher, are not at risk from consumption of fish and aguatic
invertebrates contaminated with cadmium, copper, lead, or zinc. Insectivorous birds,
represented by marsh wren, may be at risk from cadmium, lead, and zinc in the most
contaminated areas.
• Carnivorous mammals, represented by lynx, do not appear to be at risk from ingestion
of contaminated prey based on (1) expected low bioaccumulation of COCs, (2) limited
use of disturbed habitat, (3) assumption of incomplete exposure pathway associated
with cadmium in soil, willows, and cadmium-contaminated prey, and (4) the results of
dose estimations for predator species identified as being at the greatest risk
(e.g., mink).
-------
• Throughout much of the site, greatly reduced concentrations of metals in surface
water, sediment, and surface soils are needed to protect sensitive organisms
inhabiting or using these media.
• The Tenmile Creek Near Rimini Subarea exhibits the highest risks from all media.
This area is also a continuing source of toxic water and sediments for downstream
reaches.
• In general, risks associated with the Beaver Creek, Minnehaha Creek, and Tenmile
Creek Mainstem Subareas are lower than Tenmile Creek Near Rimini Subarea, but higher
than the Upper Tenmile Creek/Monitor Creek, Banner Creek/Ruby Creek, and Bear Gulch/
Walker Creek Subareas.
7.3 Risk-Based Preliminary Remediation Goals
Human Health PRGs
Table 7-17 presents risk-based PRGs for arsenic and lead in solid media for residents and
arsenic in solid media for workers and recreationists. For residents, the RME exposure
PRGs for lead and arsenic are exceeded in all subareas. The CTE exposure PRGs are exceeded
in five subareas for arsenic and in six subareas for lead. For workers, the arsenic PRG is
exceeded in five subareas for RME exposure and four subareas for CTE exposure. For
recreationists, the arsenic PRG is exceeded for five subareas for RME exposure and one
subarea for CTE exposure.
Potential PRGs were calculated for other exposure pathways in the HHRA. However, they have
not been used in the ROD to establish cleanup standards because (1) other appropriate
cleanup standards are established (ARARs for surface water and groundwater), (2) no action
is the current selected remedy (for sediments), or (3) all site concentrations were lower
than the potential PRGs (air).
Ecological PRGs
Concentrations of dissolved cadmium, copper, and zinc in surface water are compared to
specific effects concentrations or levels of protection. Figures 7-1 through 7-3 present
several effects concentrations associated with specific receptors (e.g., rainbow trout,
brook trout, and daphnids) or levels of protection directly related to important
ecological goals for this site (e.g., trout survival). These figures reveal a range of
concentrations of dissolved metals in surface water that would represent significant
improvements in the condition of the aguatic ecosystem of Tenmile Creek. Established PRGs
for surface water are the aguatic life standards established in DEQ Circular WQB-7 (see
Section 12.6), which also consider food chain and sediment effects.
The data presented reveal that significant ecological benefits related to trout and
aguatic invertebrate populations can be realized by implementing the selected remedy. This
assumption is supported by recent findings (DFWP 2001) that suggest that large decreases
in numbers or mass of trout per lineal reach of stream were found only in the most highly
contaminated areas (near Rimini). It is recognized that population or total mass of trout
may not reflect trout growth rates or reproductive success, but these are considered some
indication of the suitability of Tenmile Creek waters for trout. In spite of limited
regional data on sublethal or indirect effects on trout, increased numbers of trout and
aguatic invertebrates appear to be attainable by implementing the selected remedy.
7.4 Basis of Action
The response action for the site selected in this ROD is warranted to protect the public
health or welfare or the environment from actual or threatened releases of hazardous
substances into the environment and of pollutants or contaminants that may present an
imminent and substantial endangerment to public health or welfare.
-------
Table 7-17
Preliminary Remediation Goals
For Potential Exposure Through Ingestion of Solid Media
(Waste Rock, Tailings, and Surface Soil)
Risk Level
Carcinogenic Risk
1.00E-06
1.00E-05
1.00E-04
Noncarcinogenic Risk (HQ = 1)
Residential Exposure
Arsenic
(mg/kg)
RME
0.6
6.0
60.0
CTE
12.0
120.0
1,200.0
Lead
(mg/kg)
RME
-
-
-
CTE
-
-
-
124.0
674.0
400.0
950.0
Industrial Worker Exposure
Arsenic
(mg/kg)
RME
2.9
29.0
290.0
CTE
49.0
490.0
4,900.0
Lead
(mg/kg)
RME
-
-
-
CTE
-
-
-
471.0
2,092.0
-
-
Recreational User Exposure
Arsenic
(mg/kg)
RME
7.2
72.0
720.0
CTE
144.0
1 ,440.0
14,400.0
Lead
(mg/kg)
RME
-
-
-
CTE
-
-
-
1,397.0
8,330.0
-
-
Site Concentrations (Min and Max) Compared with RME and CTE PRGs for Each Exposure Scenario
Subarea
Tenmile Creek Near Rimini
Beaver Creek
Minnehaha Creek
Tenmile Creek Mainstem
Upper Tenmile Creek/Monitor Creek
Bear Gulch/Walker Creek
Banner Creek/Ruby Creek
Arsenic
(mg/kg)
min
13.9
13.3
41.0
15.2
4.5
816
3.1
max
121,000
6,669
4,356
3,861
93.0
108
729
Lead
(mg/kg)
min
32.1
37.2
19.9
19.7
29.1
59.0
18.0
max
48,700
13,971
22,968
2,410
957
452
5,569
Arsenic
(mg/kg)
min
13.9
13.3
41.0
15.2
4.5
81.6
3.1
max
121,000
6,669
4,356
3,861
93.0
108
729
Lead
(mg/kg)
min
-
-
-
-
-
-
-
max
-
-
-
-
-
-
-
Arsenic
(mg/kg)
min
13.9
13.3
41.0
15.2
4.5
81.6
3.1
max
121,000
6,669
4,356
3,861
93.0
108
726
Lead
(mg/kg)
min
-
-
-
-
-
-
-
max
-
-
-
-
-
-
-
RME = reasonable maximum exposure
CTE = central tendency exposure
HQ = hazard quotient
PRG = preliminary remediation goals
- = Not applicable. Lead risks are noncancer and are relevant only to residential exposure scenarios.
Italic indicates concentration exceeds the RME exposure scenario for excess cancer risk of 10E-04 or noncancer criteria ofHQ> 1.
Table xlssoi!7-17
-------
Figure 7-1
Effects Concentrations/Level of Protection - Dissolved Cadmium in Surface Water
g
-
6
ft
8 -
a .
"C. J
c.
D
a.
1
I3:
g .
'•
1
o -
"a
Protects daphrtld from sublethal effects, and expect*
rated olher sensitive aquatic biola (CFR ERA, E PA 1
Is
H it'
0.6
Protects a wide variety of frssfiwgter fistx
water column and benUiic invertebrates, amtf
aquatic plants from subleihsl effects (£PA i ?Q5aj
1.1
Pretocts survival of a wide variety of freshwater
Ish, water column and benthie invertebrates,
arttf aquatic plants (EPA I985a)
1.6
Species Mean Chronic Value (SMCV)
proteas brook (rout from subtelhal
sBerts, hirtrwis <50 (EPA l9S5a)
2 04
1 m
IB a
^3 t- fll
3 S" 9
d lo protect rainbow trout survival. Calculated
value is less than chronic value; CFR ERA
t>t fully applicable to hartfnass less than 50 rng/L
22
Protects rainbow trout from sublethal
sRteeii (CFR ERA, EPA 1999)
2.3
7.1
i
Proteds daphnld survrval. and expedei:
other sefisHlve ^ooptanMon (CFR ERr\
rn ^
u
4fi Sf
Jg 0
•".^r
j
Oaphnid Chronic Chronic AWQC(1) Acute AWQC(1)
TRV
Brook Trout Geo
SMCV
Rainbow Trout
Acute TRV
Rainbow Trout
Chronic TRV
Daphnid Acute
TRV
Effects Value/Endifwint/TRV
Note: (1) When the ERA evaluation for cadmium was completed in 2001, the AWQC was at the concentration noted. In January 2002, DEQ lowered the aquatic life standards for cadmium.
-------
25
20
15
5-
Figure 7-2
Effects Concentrations/Level of Protection - Dissolved Copper in Surface Water
fb
c *z
Protects a wid« variety of fresh*
vater column and benihic Jnvtrtei
alic plants from sublelhal effeds
f"1™"" SL
a
"*" « 31
« I*3"
2
4,1
•'
•• H«Q
Q ft
aft
-i S
« ii
mhl from subtethal effects, and e:
tnsWvB aquatic bigta {CFR ERA,
m€
TJ Jf
3* 3
Is
4.2
Q-
9 M
u «
laplinid survival, and expected ta
stive zwjpIinNton (CFR ERA, EF
> TJ
i 13
so S-
"— '
5
f a
a 1
Is &
5 c «
Bt n e
ruivfll of a wide variety of freshvirt
in and benthic invertebrates, am:
from suWethal effects (EPA 198
^7 fi* ®
e d«
DI tn
eft 3"
fl -
6
.•"
m "D ^
3! 3 1
| S 3
ill
|g =»
m f O
hronic Val ue (SMC V) ^
Iroul from sublathal *-
»ss «5O f EPA 1 iB55 **
20
•o
3
. Al x
3 a
79 , 3
.mi-
•>|
'ii
s'g-
•&'
ZQ.BQ
•M--
u. -3P j
i "Co
, •fl .
o §'•'
•'S 1'
-S
4(5 "CT"
-'.m.
23.!
TJ .
'I- '
. s .
'.1
•OJ
o.
»
?
*s
• — h,'
J
ChronieAWQC
Daphnid
Chronic TRV
Daphmd Acute
TKV
Aojte AWQC
Brooh Trout Geo
SMCV
RBT Chronic
TRV
Whit©
SMCV
RBT Acute TRV
Effects Vaiue/Endpofnt/TRV
Fig 7-1 thru Effects Conc.xIsCu
-------
Figure 7-3
Effects Concentrations/Level of Protection for Dissolved Zinc in Surface Water
iJW
2000-
5. 1500
Br
1
|
*
a.
£ 1000 •
SOD
n -
9> »
3 2.
f»
*»
T S S
3 i1!
!| if | If.
5.— CB 73 55! Hf .m Q -*• jr-'
SB 1 2 •§ | w S. -B * iff
w- ""^ ~* 3l! P31 j^, 5 S*'0 St 5 jj^ c"
JJ. &" 3 E" «? "^nS1 ? ^H. Sp rrt W"0
f * i3§ »|a l^- E| g* "1
|§ y=| f|S | = || | ^J
11 111 fit *i, s f I f?
n& §-§"» «S< t£ 55 " >1
a-J 25 1. &»S i " 5^ ' "*^
i" S ^ s" < ^S1? ?5 3. m 5 5 ^ 1
OQ ^Sa, — — . -» sjx >3 "
jj S a'*"ji- SiS? rn"2 '*w ?f
fa Cfl n* ** T Sft j^ O arj CT" Ji BEK
3s •mil & ft i -s a s | J 855
"'S. "^ 8 ^ S3" US 'A^Mft
285 ^^ ^'^^
i n • ^^^"^^»™ , _^^ Jdt'»'_'^.
^, :W^r|' 'B»M^ lffp^
42,1 54 54 ff-°
1996
&&*. , KC .
-^p
-Sil
5WSJ A
life
I , ^r,«.< , , ,,. „! , rial , 1. .»nr> -«,.„ ,„ "" "m*"*' | — ' — |
Diphnict Acute AWQC Chronic AWQC Oaphnid Acute RUT Chronic RST Acute TRV Brook Trout Brook Trout
CtironicTRV TRV TRV SMCV SMAV
Effects Vilua/Endpoint/TRV
Fig 7-1 thru 7-3 Effects Conc.xIsZn
-------
Section 8
Remedial Action Objectives
The remedy outlined in this ROD is intended to be the final remedial action for the site.
Remedial action objectives (RAO) are media- specific (e.g., mine waste, surface water,
etc.) statements of what needs to be accomplished to protect human health and the
environment.
To meet the RAOs for the site, EPA has established remediation, or cleanup levels, that
the selected remedy must meet. The site cleanup levels are identified and discussed in
Section 12.
EPA has established the following RAOs for the site:
Mine Wastes, Soils, and Sediment
• Achieve acceptable exposure risks for residents and visitors
• Achieve acceptable exposures risks for terrestrial and aguatic species
Surface Water
• Protect current and reasonably anticipated future source waters for the Helena water
supply system
• Achieve acceptable exposure risks for residents and recreational visitors through
attainment of surface water guality standards
• Achieve acceptable exposure risks to terrestrial and aguatic species through
attainment of surface water guality standards
Groundwa ter
• Protect current and reasonably anticipated future users of groundwater
• Control groundwater contaminant plumes at mine adits and waste source areas through
the use of source control measures
• Prevent or minimize contaminant loading from the near-stream groundwater underlying
mine waste source areas to surface water
-------
Section 9
Description of Alternatives
The remedial alternatives for the site evaluated in the FS (CDM 2001e) and RI/FS (CDM
2001c) addenda are presented in this section. The selected remedy for the site is the
preferred alternative identified in the proposed plan (comprehensive mine site Alternative
5 and Rimini water supply Alternative D), modified to include excavation of additional
contaminated yard soils and roadway materials.
A full range of potential alternatives for remediating each contaminated medium was
evaluated in the FS in accordance with EPA evaluation reguirements. Process technologies
evaluated in the screening stage were assembled into alternatives and the alternatives
were analyzed during the evaluation stage. Certain alternatives were then carried forward
and subjected to detailed and comparative analysis in the FS. These alternatives were
analyzed on a media- specific and subarea-specific basis utilizing seven of the NCP
evaluation criteria. The media-specific alternatives were also assembled into
comprehensive sitewide alternatives for mine site cleanup. Alternatives for establishing a
source of uncontaminated drinking water for Rimini were evaluated separately. Descriptions
of the media- specific, comprehensive sitewide mine site, and Rimini water supply
alternatives are provided in the following sections.
9.1 Media-Specific Alternatives
9.1.1 Waste Rock and Tailings
Four alternatives for remediating waste rock and tailings were considered. These
alternatives included no action (WR1); surface controls (WR2), which would consist of
waste consolidation, regrading, reconstructing surface water drainages, adding
neutralizing amendments to the waste surface, and vegetating the disturbed area;
containment (WR3), which is the same as surface controls, but also includes capping wastes
with either a soil cover alone or with a geomembrane liner; and excavation and onsite
disposal at the Luttrell repository (WR4).
During the preparation of the FS, the mine sites containing waste rock and tailings were
grouped into five categories, based on the relative potential of the waste materials to
present exposure risks and to impact surface water and groundwater resources. Category A
sites have the least potential for causing adverse impacts, while Category E sites have
the greatest potential. The category of each mine site, based on existing information, is
shown in Table 9-1. Site scores used to group the sites by category, are presented in
Appendix B. The locations of the mine sites, by category, are shown on Figures 9-1 through
9-7. EPA will collect additional data during the detailed design of specific mine site
cleanups. Sites will be reevaluated and the relative ranking and categories of some sites
may change as the more detailed design data become available.
9.1.2 Acid Mine Drainage
Five alternatives for remediation of AMD were considered in the FS. They included no
action (ADI); natural attenuation (AD2), which would consist of allowing natural
processes, such as weathering, dilution, and chemical/biological reactions, to reduce
contaminant toxicity and mobility over time, with confirmation monitoring; source controls
(ADS), which would include regrading, capping, and blocking pathways for surface water to
enter underground mine workings to reduce the volume of AMD; biological treatment (AD4),
which would consist of source controls to reduce the volume of AMD, plus the construction
of wetlands and other reactive cells for the treatment of the AMD, with wetlands substrate
or sludges periodically removed and placed at the Luttrell repository; and physical/
chemical treatment (ADS), which would include source controls to reduce the volume of AMD,
plus construction of mechanical treatment plants, probably using lime precipitation and
activated alumina or reverse osmosis filtration, for treating the adit discharges.
-------
Table 9-1
Mine Site Category and Adit Discharge Summary
Site Name
1900
Alice Lode
Alley Fraction
American Flag
Armstrong
Atlas
Avon Mill
Ballou
Banner Creek Placer
Banner Creek Tailings
Bear Gulch
Beatrice
Beatrice East
Beatrice North
Beatrice South
Belle
Black Hawk
Blue Boy
Bunker Hill
Bunker Mile
Cappolis
Carlson Mine
Castle rock
Catherine
Chessman
Clontart/Carp
Close Shave
Colorado
Comstock
Conflict
Coon Creek Mill
Copper Dyke
Site Number
MS117
MS075
MS316
MS044
MS070
MS334
MS110
MS072
MS330
MS023
MS043
MS071
MS308
MS309
MS062
MS076
MS002
MS067
MS098
MS319
MS036
MS118
MS077
MS305
MS320
MS078
MS079
MS306
MS339
MS111
MS124
MS003
Subarea
UT
TR
TR
TR
MC
RC
TR
TR
RC
RC
BG
MC
MC
MC
MC
TR
RC
MC
TR
TR
TR
UT
TR
TR
BC
TR
TR
BC
UT
TR
UT
RC
Site Category
B
B
C
C
A
B
A
A
A
A
B
A
A
C
A
C
B
A
E
D
B
A
C
B
A
D
B
A
C
D
C
A
Discharging
Adit?
/
/
/
/
/
/
/
UT = Upper Tenmile Creek/Monitor Creek Subarea
RC = Banner Creek/Ruby Creek Subarea
TR = Tenmile Creek Near Rimini Subarea
BC = Beaver Creek Subarea
MC = Minnehaha Creek Subarea
BG = Bear Gulch/Walker Creek Subarea
TM = Tenmile Mainstem Subarea
Table 9-1 Mine Site Categories.doc
-------
Table 9-1 (Continued)
(Continued) Mine Site Category and Adit Discharge Summary
Site Name
Danley
Dan Kim
Daniel Stanton
Eureka
Evergreen
Evergreen #2
Evergreen #3
Evergreen Reclamation
Fairview #23
Fairview#25
Former Stanton
Free Speech #1
Garfield
General
Gold Coin
Gold Coin Trench
Gold Crown
Gold Hill
Green Grove
Green Tree
Green Tree North
H. Davis
H. Grattan
Hamlet
Helena
Hidden Treasure
Horsefly Adit
Isabelle Placer
Jackson Lode
Jill
Site Number
MS045
MS004
MS080
MS112
MS324
MS089
MS133
MS136
MS135
MS081
MS323
MS046
MS005
MS099
MS006
MS119
MS040
MS007
MS332
MS025
MS313
MS315
MS082
MS100
MS026
MS321
MS055
MS333
MS307
MS120
Subarea
BC
RC
TR
TR
TR
TR
TR
TR
TR
TR
TR
TR
RC
TR
UT
UT
BG
RC
TR
RC
RC
TR
TR
TRT
RC
TR
BC
UT
BC
UT
Site Category
E
B
C
A
E
C
E
A
C
C
D
A
C
B
A
A
A
B
A
D
B
B
B
C
D
E
C
A
C
A
Discharging
Adit?
/
/
/
/
/
UT = Upper Tenmile Creek/Monitor Creek Subarea
RC = Beaver Creek/Ruby Creek Subarea
TR = Tenmile Creek Near Rimini Subarea
BC = Beaver Creek Subarea
MC = Minnehaha Creek Subarea
BG = Bear Gulch/Walker Creek Subarea
TM = Tenmile Mainstem Subarea
Table 9-1 Mine Site Categories.doc
-------
Table 9-1 (Continued)
(Continued) Mine Site Category and Adit Discharge Summary
Site Name
Jimmy
JJ Hill Claims
Johny#1
Johny#2
Jolly Roger
Jumbo
Justice
Kelly Mill
Knight of Gwinnie
L&H.
Lady Hennessy
Lady Washington
Last Resort 2
Lee Mountain
Lexington
Lexington East
Little Giant
Little Lily
Little Sampson
Little Sampson East
Lode
Louise Lode
Lower Tenmile Mill
Lucky Joe
Lucky Linda
Lulu
Mary Aloys
May Day
May Lillie
Micawber
Site Number
MS008
MS058
MS064
MS134
MS009
MS090
MS068
MS073
MS083
MS335
MS033
MS304
MS327
MS091
MS092
MS301
MS331
MS084
MS101
MS329
MS041
MS328
MS074
MS065
MS011
MS012
MS013
MS121
MS014
MS093
Subarea
RC
BC
TR
TR
RC
TR
MC
TM
TR
RC
UT
TR
TR
TR
TR
TR
BC
TR
TR
TR
BG
BC
TM
MC
RC
RC
RC
UT
RC
TR
Site Category
A
A
E
E
A
E
A
A
C
E
A
C
C
E
C
C
C
A
B
C
A
B
B
E
B
A
C
A
A
E
Discharging
Adit?
/
/
/
/
/
UT = Upper Tenmile Creek/Monitor Creek Subarea
RC = Beaver Creek/Ruby Creek Subarea
TR = Tenmile Creek Near Rimini Subarea
BC = Beaver Creek Subarea
MC = Minnehaha Creek Subarea
BG = Bear Gulch/Walker Creek Subarea
TM = Tenmile Mainstem Subarea
Table 9-1 Mine Site Categories.doc
-------
Table 9-1 (Continued)
Mine Site Category and Adit Discharge Summary
Site Name
Mineral Deposit
Monitor Creek Mill
Monitor Creek Placer
Monitor Creek Tailings
Monte Cristo
National Extension
NENWS16
NE NW S23
NE NW S4
NE NW S34
New Castle
NO Name
North Pacific
NWNES16
NW NW S34
NW NW S9
NW NW S3
Omaha South
Puapers Dream
Paupers Dream Camp
Peerless Jenny
Peerless King
Perseverance
Peter
Pilgrim
Pocahontas
Porphy Dike
Queenbury
Queenbury North
Red Mountain
Red Mountain East
Site Number
MS032
MS125
MS126
MS130
MS034
MS060
MS015
MS122
MS056
MS061
MS016
MS102
MS094
MS027
MS086
MS028
MS048
MS338
MS128
MS310
MS035
MS018
MS036
MS029
MS057
MS066
MS123
MS037
MS314
MS114
MS303
Subarea
TR
UT
UT
UT
RC
BC
RC
UT
BC
BC
RC
TR
TR
RC
TR
RC
BC
RC
UT
UT
RC
RC
RC
RC
BC
MC
UT
RC
RC
TR
TR
Site Category
E
D
A
C
E
E
A
A
B
A
A
B
A
A
B
C
A
E
B
C
A
A
B
C
D
C
B
C
B
A
C
Discharging
Adit?
/
/
/
/
/
/
/
/
/
/
/
UT = Upper Tenmile Creek/Monitor Creek Subarea
RC = Beaver Creek/Ruby Creek Subarea
TR = Tenmile Creek Near Rimini Subarea
BC = Beaver Creek Subarea
MC = Minnehaha Creek Subarea
BG = Bear Gulch/Walker Creek Subarea
TM = Tenmile Mainstem Subarea
Table 9-1 Mine Site Categories.doc
-------
Table 9-1 (Continued)
Mine Site Category and Adit Discharge Summary
Site Name
Red Mountain Tunnel
Red Water
Rob Roy
Ruby Fraction
S.P. Bassett
SESES10
SESES13
SE SE S3
Silver Chief
Silver Cresent
Silver Wave
South Pacific
Susie
SW SE S5
Teal Lake
Treasury #1
Tunnel Lode
Unknown (Beaver Creek)
Unnamed
Upper Tenmile Shaft
Upper Valley Forge
Virginia
W. Coyne
WA Alley
WA Alley 2
Wolftone
Woodrow Wilson
Site Number
MS104
MS115
MS087
MS019
MS105
MS051
MS132
MS059
MS322
MS021
MS317
MS052
MS116
MS107
MS108
MS022
MS326
MS053
MS042
MS129
MS097
MS337
MS318
MS031
MS311
MS109
MS038
Subarea
BC
TR
TR
RC
TR
BC
UT
BC
TR
RC
TR
TR
TR
TR
TR
RC
TR
BC
BG
UT
TR
UT
TR
RC
TR
TR
RC
Site Category
B
A
B
C
E
C
A
B
D
A
C
D
A
D
C
C
C
A
A
A
E
A
C
C
E
C
C
Discharging
Adit?
/
/
/
/
/
/
UT = Upper Tenmile Creek/Monitor Creek Subarea
RC = Beaver Creek/Ruby Creek Subarea
TR = Tenmile Creek Near Rimini Subarea
BC = Beaver Creek Subarea
MC = Minnehaha Creek Subarea
BG Bear Gulch/Walker Creek Subarea
TM = Tenmile Mainstem Subarea
Table 9-1 Mine Site Categories.doc
-------
Cdmstoci/Momtnr Creek Tailings'
' ^Virginia
Paupen Dream Cam
Paypere Dream
Legend
02 R* fli OJ
Figure 9-1
Upper Tenmlle Creek/Monitor Creek Subarea
Upper Tenmlle Creek Mining Area Site
Te-nT. .t, CM
COM
-------
Peerless Ki
Ptertess Jenpy
O Silver Cr««t
Lagwitt
O Mm mm Otoe»iHilB» **i
oj ct
Figure 9-2
Banner Creek / Ruby Creek Subarea
Upper Tenmlle Creek Mining Area Site
ITetra Tern EJifl Inr
-------
Upper Valley Forge
*H. Gmttan
^
SEE FIGURE »-38 '
FOR CLOSEUP I
Figure 9-3a
Tenmile Creek Near Rimini Subarea
Upper Tenmile Creek Mining Area Site
C5WWI Federal
-------
ALastRestttZ
RIRad Wrttr
Mom
Frw Speech #1
Bella A
Lfflte Sampson
Utti*£
Sampson Ea
orth Paofic
ARed Mountain East
C»tU* Rock A
-------
Wm«y Us**
o
C.uoory D Mlnni
Figure 9-4
Beaver Creek Subarea
Upper Tenmile Creek Mining Area Stte
Tech EM ire
FoVtal Froytaiiw i-^ffxarrt
-------
Mi™ Wt» Ourt,iri)li.(i Aatl
•ir t**sor, B Mr™
A Cilmgorj C Mm-
Cal^jiirv I Minn
. a*»*i» wnA^i
D.J8
OJO
Figure 9-5
Minnehaha Creek Subarea
Upper Tenmile Creek Mining Area Site
iTtsliu Tach EM Inc.
COM
-------
L»o*nd
O >*n« Wl* Ol.ctiiroiiB *
-------
-------
In consultation with DEQ, EPA developed a modified AMD alternative (Modified AD4/5) in an
effort to minimize the costs of long- term O&M for treating AMD. Modified AD4/5 is a
phased approach that first attempts to reduce adit discharge flows and then provides for
subseguent treatment of discharge waters if necessary to meet state water guality
standards. The approach is based on EPA's commitment to implement a comprehensive cleanup
of mine waste sources so that long-term O&M needs can be minimized. The primary remedy
feature that may entail considerable O&M costs is the long- term treatment of AMD from the
mine adits. Alternative AD4/5, which EPA would implement in full consultation with DEQ, is
described in the following paragraphs.
Phase 1 - Initial Design Investigations
This phase consists of an overall assessment of the potential to achieve significant 0& M
cost savings through source controls to reduce the volume of AMD from individual mines. It
includes the following elements:
• Investigate mine maps, records, and geology of specific mine workings
• Evaluate and map potential surface water inflows to mine workings
• Identify mine sites where flow reduction technigues could be potentially successful
• Conduct sampling and/or tracer studies to determine water inflow and contaminant
release locations
Phase 2 - Source Control and Flow Reduction Design Studies
Phase 2 consists of detailed design investigations and pilot studies at certain mine sites
to demonstrate source control and flow reduction technigues. It includes the following
components:
• Open portals and adits where possible to gain access to mine workings
• Conduct additional detailed sampling or tracer studies if necessary
• Conduct pilot studies of flow segregation, grouting, mine plugging, or other
technigues
Phase 3 - Source Control and Flow Reduction Implementation
This phase consists of full-scale implementation of source control and flow reduction
measures at specific mine sites. It includes the following components:
• Implement full scale flow reduction actions at mine sites where it is deemed
appropriate
• Continue to monitor success of flow reduction actions
Phase 4 - Design and Construction of AMD Treatment Facilities
Phase 4 consists of the design and construction of appropriate treatment facilities
(either passive biological or physical/chemical systems) where necessary to meet State of
Montana ambient water guality standards. Phase 4 components include:
• Evaluate treatment needs and options to address adit discharges remaining after
source control/flow reduction efforts
• Design treatment facilities appropriate for each discharging adit of concern
• Construct appropriate treatment facilities
-------
The implementation of Alternative AD4/5 would take a number of years. EPA would begin the
adit discharge flow reduction effort at the beginning of remedial design, but the timing
of subseguent action would be dependent on the results of the initial studies. To address
mine sites with substantial adit discharge flow rates and loadings, such as those in the
Rimini area, would reguire several years of investigation and pilot studies.
Although EPA and DEQ are hopeful that flow reduction will significantly reduce or
eliminate the need for long-term treatment at many mine sites, in preparing the proposed
plan and this ROD, EPA has conservatively assumed, for evaluation and cost estimating
purposes, that either passive biological or physical/chemical treatment will be necessary
at all mine sites with AMD. This was done so that the relative effectiveness,
implementability, and cost differences between passive biological systems and
physical/chemical systems could be evaluated.
Mine sites exhibiting acid mine drainage were identified in Table 9-1. All discharging
adits will be evaluated in detail during remedial design. In addition to determining
treatment needs, after collecting additional adit discharge data and considering potential
flow reduction options, EPA, in consultation with DEQ, will reevaluate the contaminant
loadings from small adit discharges relative to potential adverse environmental impacts
from constructing treatment facilities. At that time, EPA may determine, in consultation
with DEQ, USFS, and property owners, that adit discharges at remote, roadless locations
with minimal loadings to the streams may appropriately be left undisturbed.
9.1.3 Contaminated Surface Water
Five alternatives for remediating contaminated surface water were evaluated. They included
no action (SW1) ; natural attenuation (SW2); additional water storage (SW3), which would
consist of constructing additional water storage capacity in the upper Tenmile Creek
drainage to allow larger in-stream flows that would improve water guality downstream,
biological treatment (SW4); and physical/chemical treatment (SW5). Three potential
additional storage approaches were considered: constructing new reservoirs at the Travis
location or the Banner Creek location, or increasing the capacity of the existing Chessman
Reservoir. The locations of the three reservoir options were shown on Figure 1-2.
9.1.4 Contaminated Stream Sediments
Three alternatives for remediating contaminated stream sediments were considered. They
included no action (SD1); natural attenuation (SD2); and excavation and onsite disposal at
the Luttrell repository (SD3) , which would consist of excavating (mechanical or hydraulic
dredging) and dewatering the removed sediments, and transporting and placing the wastes at
the Luttrell repository.
9.1.5 Contaminated Groundwater
Nine alternatives for addressing contaminated groundwater were considered. The primary
focus of remedial action for groundwater will be to prevent exposure to contaminants via
drinking of impacted groundwater. The first three alternatives were no action (GW1);
natural attenuation (GW2); and groundwater use controls (GW3), such as deed restrictions
or establishment of a controlled groundwater area. The remaining six alternatives
addressed the establishment of an alternative source of potable water for the community of
Rimini. They included shallow wells (GW4), whereby existing individual wells would be
replaced with a minimum of two shallow community wells in the alluvial deposits along
Tenmile Creek or a tributary, and a water tank, distribution, and disinfection system for
the community; deep wells (GW5), which would be the same as alternative GW4, except using
deeper bedrock wells instead of shallow alluvial wells, which would not reguire a
disinfection system; surface water (GW6), which would include the community distribution
system, but would reguire full treatment of the source water in addition to disinfection;
Spring Creek source (GW7), which would be similar to alternatives GW4 and GW5, but would
tap into the uncontaminated groundwater source at Spring Creek; treated groundwater (GW8),
which would utilize the treated groundwater from alternative ADS as the source water and
-------
would require construction of the community storage, distribution, and disinfection
system; and physical/chemical treatment (GW9) using individual point-of-use (POU)
treatment systems at residences within the community of Rimini.
9.1.6 Contaminated Yards
Four alternatives were considered for remediating contaminated yards at residences and
recreational cabins. These included no action (RY1); capping (RY2), which would consist of
consolidating contaminated yard soil where appropriate, regrading, adding neutralizing
amendments to the upper layer of soil surface, capping the area with 12 inches of fill and
6 inches of topsoil, and vegetating or sodding the soil cap; excavation and onsite
disposal at the Luttrell repository (RY3), which would consist of excavating contaminated
yard soil to a depth of 18 inches, transporting and placing waste at the Luttrell
repository, and reclaiming the excavated yards with clean backfill, topsoil, and sod; and
excavation and disposal of all accessible contaminated yard soils (RY3B). Alternative RY3B
was developed and evaluated in the ROD to address the state's desire to minimize the
volume of contaminated soils left in place and the need to rely on institutional controls
to control potential future exposure to residual contaminants on site.
EPA has also added a contingent element to the contaminated yards removal alternative to
provide for the replacement of individual wastewater treatment septic systems that may be
damaged or otherwise have to be removed during the excavation of contaminated yard soils.
Many of the existing septic systems in Rimini are located near Tenmile Creek or in the
100-year floodplain and cannot be replaced in compliance with current design standards.
Contingent Alternative RY3CS consists of a small community wastewater collection and
treatment system to replace individual septic systems removed during the excavation of
yard soils.
9.1.7 Contaminated Roadway Materials
Five alternatives were considered for remediating contaminated roadway materials. These
included no action (RD1); capping with gravel (RD2), which would consist of regrading and
capping the roadway with 18 inches of clean road base material; capping with asphalt
(RD2B) , which would consist of regrading and capping the roadway with approximately 6
inches of gravel and 2.5 inches of asphalt; excavation and onsite disposal at the Luttrell
repository (RD3), which would consist of excavating contaminated roadway material to a
depth of 12 inches, transporting, and placing waste at the Luttrell repository, and
backfilling the excavated areas with 12 inches of clean road base material; and excavation
of all accessible contaminated roadway materials (RD3B), which would consist of removing,
transporting, and disposing (at the Luttrell repository) of all accessible contaminated
roadway materials. Alternative RD3B was developed and evaluated in the ROD to address the
state's desire to minimize the volume of wastes left in place and the potential for
release of contaminants in the future.
9.2 Development and Evaluation of Sitewide Remedial Alternatives
This section presents the development and evaluation of remedial alternatives being
considered for comprehensive, sitewide cleanup and alternatives considered to address the
water supply for the community of Rimini. Representative groupings of media- specific and
subarea-specific alternatives were assembled into comprehensive sitewide alternative
packages to allow for evaluation of the interaction of alternatives for different media
and comparison of the estimated costs of implementing potential sitewide actions. The
alternatives that follow are the comprehensive sitewide alternatives. This evaluation
gives an overall comparison of the cost and effectiveness of potential sitewide remedies.
Active treatment of surface water, which is considered cost prohibitive, is not included
in any of the comprehensive sitewide alternatives. Improvements in surface water quality
would be achieved through the implementation of other source control measures, or through
construction of additional water storage for flow augmentation.
-------
Table 9-2
Summary Description of Sitewide Alternatives
Remedy
Component
Waste Rock/Tailings
Acid Mine Drainage
Surface Water
Groundwater
Sediments
Residential Yards
Roadway Materials
O&M Requirements
Monitoring Requirement
Estimated Total Cost
Schedule
Alternative 1
No Action (WR1)
No action (AD1)
No action (SW1)
No action (GW1)
No action (SD1)
No action (RY1)
No action (RD1)
None
None
$0
None
Alternative 2
Category A and B sites - no
action (WR1)
Category C sites - surface
controls (WR2)
Category D sites - cap in place
(WR3)
Category E sites - remove to
Luttrell repository (WR4)
Source control and flow
reduction, followed by treatment
of adit discharges (Modified
AD4/5)
No action (SW1)
Groundwater use controls (GW3)
No action (SD1)
Remove to Luttrell repository
(RY3)
No action
Long-term treatment of AMD;
annual O&M of reclaimed sites;
maintain institutional controls
Long-term monitoring of surface
water, groundwater, and AMD
$15,158,000
Construction for 10 years; O&M in
perpetuity
Alternative 3
Category A and B sites -no
action (WR1)
Category C sites - cap in place
(WR3)
Category D and E sites - remove
to Luttrell repository (WR4)
Source control and flow
reduction, followed by treatment
of adit discharges (Modified
AD4/5)
No action (SW1)
Groundwater use controls (GW3)
No action (SD1)
Remove to Luttrell repository
(RY3)
No action
Long-term treatment of AMD;
annual O&M of reclaimed sites;
maintain institutional controls
Long-term monitoring of surface
water, groundwater, and AMD
$15,648,000
Construction for 10 years; O&M in
perpetuity
Alternative 4
Category A and B sites - no
action (WR1)
Category C, D, and E sites -
remove to Luttrell repository
(WR4)
Source control and flow
reduction, followed by treatment
of adit discharges (Modified
AD4/5)
No action (SW1)
Groundwater use controls (GW3)
No action (SD1)
Remove to Luttrell repository
(RY3)
Remove to Luttrell repository
(RD3)
Long-term treatment of AMD;
annual O&M of reclaimed sites;
maintain institutional controls
Long-term monitoring of surface
water, groundwater, and AMD
$18,195,000
Construction for 10 years; O&M in
perpetuity
Table 9-2.wpd
-------
Table 9-2 (continued)
Summary Description of Sitewide Alternatives
Remedy Component
Waste Rock/Tailings
Acid Mine Drainage
Surface Water
Groundwater
Sediments
Residential Yards
Roadway Materials
O&M Requirements
Monitoring Requirement
Estimated Total Cost
Schedule
Alternative 5
(as modified)
Category A and B sites - no action
(WR1) Category C, D, and E sites -
remove to Luttrell repository (WR4)
Source control and flow reduction,
followed by treatment of adit
discharges (Modified AD4/5)
Construct additional water storage in
Chessman Reservoir for Tenmile
Creek flow augmentation (SW3)
Groundwater use controls (GW3)
No action (SD1)
Remove to Luttrell repository (RY31B)
and contingency for Rimini
community sewer system (RB3CS)
Remove to Luttrell repository (RD2B)
Long-term treatment of AMD; annual
O&M of reclaimed sites; maintain
institutional controls
Long-term monitoring of surface
water, groundwater, and AMD
$22,204,000
Construction for 10 years; O&M in
perpetuity
Alternative 6
Category A sites - no action (WR1)
Category B sites - cap in place
(WR3) Category C, D, and E sites -
remove to Luttrell repository (WR4)
Source control and flow reduction,
followed by treatment of adit
discharges (Modified AD4/5)
Construct additional water storage in
Chessman Reservoir for Tenmile
Creek flow augmentation (SW3)
Groundwater use controls (GW3)
Remove Tenmile Creek sediments
(SD3) for Rimini area only; no action
for other stream reaches (SD1)
Remove to Luttrell repository (RY3)
Remove to Luttrell repository (RD3)
Long-term treatment of AMD; annual
O&M of reclaimed sites; maintain
institutional controls
Long-term monitoring of surface
water, groundwater, and AMD
$24,657,000
Construction for 10 years; O&M in
perpetuity
Alternative 7
Category A sites - no action (WR1)
Category B, C, D, and E sites -
remove to Luttrell repository (WR4)
Source control and flow reduction,
followed by treatment of adit
discharges (Modified AD4/5)
Construct additional water storage in
Chessman Reservoir for Tenmile
Creek flow augmentation (SW3)
Groundwater use controls (GW3)
Remove Tenmile Creek sediments
for Rimini area and the mainstem
below Rimini to Walker Creek (SD3)
Remove to Luttrell repository (RY3)
Remove to Luttrell repository (RD3)
Long-term treatment of AMD; annual
O&M of reclaimed sites; maintain
institutional controls
Long-term monitoring of surface
water, groundwater, and AMD
$35,311,000
Construction for 10 years; O&M in
perpetuity
Table 9-2.wpd
-------
Likewise, active treatment of groundwater in situ, which is considered cost prohibitive
and perhaps technically impracticable, is not included in any of the comprehensive
sitewide alternatives. It is anticipated that mine site source controls will improve
ambient groundwater quality in currently impacted areas. All comprehensive sitewide
alternatives, except no action, include the implementation of groundwater use controls,
such as the establishment of controlled groundwater areas in areas with currently impacted
groundwater, to prevent the consumption of contaminated groundwater.
9.2.1 Description of Comprehensive Alternatives for Mine Site Remediation
The media-specific components of the comprehensive sitewide alternatives are listed in
Table 9-2 and discussed in the following paragraphs.
Alternative 1
The no action alternative is the baseline against which other alternatives are evaluated.
Under Alternative 1, no action would be taken by EPA at the site.
Alternative 2
Alternative 2 addresses mine waste/tailings by excavating and removing, to the Luttrell
repository, all wastes/tailings at category E sites (those sites predicted to present the
greatest threat to human health and the riparian ecosystem). In addition, this alternative
would cap in place all category D sites and provide surface controls to reduce erosion of
mine wastes at category C sites. Capping would involve consolidating waste piles (where
appropriate), grading to prevent runon of storm water onto the waste piles, constructing
an earthen cap over the waste materials, and revegetating the disturbed areas to prevent
soil erosion. The upper layer of the waste materials may be amended with lime, if
necessary, to prevent acid generation and enhance long-term vegetative growth. Surface
controls would include in- situ reclamation, with amendment and revegetation of waste
materials, but would not provide a soil cap. Institutional controls would be necessary to
prevent or guide future development on or near the reclaimed waste piles.
Alternative 2 addresses AMD sites by taking measures to control sources and reduce adit
discharge flows, followed by evaluation, design, and construction of treatment facilities.
This alternative assumes that passive biological treatment systems would be built at mines
where additional treatment is required to meet water quality standards. The treatment
systems would probably consist of shallow basins containing substrates of grassy and woody
materials, manure, and limestone to attenuate metals. Up to approximately 80 percent
removal of zinc and other contaminants would be expected, although additional biological
treatment components may be necessary. The substrate would have to be removed and replaced
periodically, with the removed substrate disposed of in the Luttrell repository.
In addition, Alternative 2 would include removal of the upper 18 inches of contaminated
residential yards, with disposal of the removed material in the Luttrell repository, and
replacement of the yards with clean soil and sod.
No action would be implemented for waste rock/ tailings at category A, B, and C mine
sites, stream sediments, and roadway materials.
Alternative 3
Alternative 3 is similar to Alternative 2, except that it would include the removal of
waste rock/tailings from category D sites, with disposal at the Luttrell repository, and
the capping of waste materials at category C sites. For other media, Alternative 3 is the
same as Alternative 2.
Alternative 4
Alternative 4 would address mine waste/ tailings by excavating and hauling to the Luttrell
repository mine wastes from category C, D, and E sites. Efforts would be implemented for
source control and flow reduction at all sites to reduce the production of AMD, followed
by design and construction of appropriate treatment facilities necessary to meet water
quality standards. This alternative assumes that the discharges from adits at three sites
-------
in the immediate Rimini area, which are major contaminant load contributors to Tenmile
Creek, would require active treatment using a physical/chemical treatment process
(probably lime precipitation and activated alumina or reverse osmosis filtration).
Biological treatment, such as that described under Alternatives 2 and 3, is assumed at
remote mine sites.
Initially, no action would be taken to remove contaminated stream sediments. Sediment
contaminant levels and the interaction between sediments and water quality would be
monitored as mine site source control were constructed to better define potential water
quality impact from the sediments. The upper 18 inches of contaminated yard soils at
residences and occasional-use recreational cabins would be removed, disposed in the
Luttrell repository, and replaced with clean yard soil and sod. Approximately 4,300 cubic
yards of contaminated roadway materials in the Rimini area would also be removed and
disposed in the Luttrell repository, with the road reconstructed to current grade.
Alternative 5 (as modified)
Alternative 5 (as modified) is the same as Alternative 5 in the proposed plan, except that
all accessible contaminated yard soils and roadway materials would be removed and a
contingency small community wastewater treatment system would be built if necessary to
replace individual septic systems damaged or removed during the yard remediation.
Alternative 5 (as modified) is the same as Alternative 4, except for contaminated yard
soils, roadway materials, and surface water. It provides additional water storage
(approximately 500 acre-feet) by increasing the capacity of Chessman Reservoir. The new
reservoir capacity would be used to store excess water during spring runoff to allow for
release of water later in the summer to maintain a minimum instream flow during dry
periods when Tenmile Creek historically has been dewatered. The reservoir upgrade would
also include an upgrade of the Red Mountain flume to increase the rate at which the
reservoir could be filled each spring. The upgraded Chessman Reservoir would be able to
provide additional water to the City of Helena water system during the low-flow period,
offsetting water that would be released past the city's Tenmile Creek water intake. The
bypassed water would come from both the natural flows of upper Tenmile Creek/Banner Creek
and stored water in Scott Reservoir. Adding approximately 3 cfs in additional flow, in
combination with mine site source control actions, would improve Tenmile Creek water
quality significantly.
Alternative 6
Alternative 6 is similar to Alternative 5, except that it also would include the capping
of an additional 28 category B sites and the excavation and removal of contaminated
Tenmile Creek stream sediments in the Rimini area. The excavated sediments would be
disposed of in the Luttrell repository. Like Alternatives 4 and 5, this alternative
assumes that treatment of AMD at three Rimini area mines would be by physical/chemical
methods and treatment of remote site AMD would be by biological treatment. The capacity of
Chessman Reservoir would be enlarged and contaminated residential/recreational yards and
roadways would be removed.
Alternative 7
Alternative 7 would include excavation and removal of mine waste/tailings at all category
B, C, D, and E sites. After removal, the sites would be backfilled, as necessary,
recontoured to approximate pre-mining conditions, and revegetated for erosion protection
and slope stability.
This alternative assumes that, after the implementation of source control and flow
reduction efforts at all discharging adits, physical/chemical treatment facilities
(probably lime precipitation and reverse osmosis) would be constructed to treat all AMD
sites, including the remote sites on Tenmile Creek tributaries. The locations of the
treatment units would be determined during remedial design. It is assumed that one
facility would be constructed in each subarea containing sites with AMD and that
discharges from individual mine sites would be piped to the subarea treatment plant for
treatment. For the remote physical/chemical treatment plant sites, power would have to be
provided via constructed transmission lines from the Rimini area.
-------
Alternative 7 would remove all contaminated sediments in the Tenmile Creek mainstem
adjacent to and downgradient of Rimini to approximately Walker Creek. The capacity of
Chessman Reservoir would be enlarged to provide flow augmentation during low flow periods.
All contaminated residential and recreational yards would be removed, replaced with clean
fill, and sodded. Contaminated roadway materials would be removed and replaced with clean
road base material.
9.2.2 Description of Rimini Water Supply Alternatives
The draft FS evaluated a no action and six action alternatives for providing potable water
to the community of Rimini. The action alternatives included various water sources and
associated treatment facilities. Four of the action alternatives are presented below. The
other two alternatives (water supply from shallow alluvial wells and from surface water
sources) are not included because they would be considerably more expensive than the other
four alternatives (at least 50 percent greater total cost), but would not provide
additional benefits.
The Rimini water supply system alternatives are listed in Table 9-3 and are discussed in
the following paragraphs.
Pi mini Water Supply Alternative A
The no action alternative is the baseline against which other alternatives are evaluated.
Under this alternative, no action would be taken by EPA to provide an alternate source of
water for the community of Rimini.
Pi mini Water Supply Alternative B
Under this alternative, small POU treatment systems would be installed in individual
residences and recreational houses/cabins where wells draw contaminated groundwater. The
system components installed in a particular residence or house would be determined during
remedial design. System components would be included as necessary to treat the specific
water used at the residence. They would likely include reverse osmosis treatment units,
but may also be supplemented by other filtration components to handle certain water
constituents present in the water from each particular source. Most systems would be sized
to treat only the water consumed for drinking and cooking, estimated to be approximately
50 gallons per day.
Pi mini Water Supply Alternative C
This alternative would involve replacing contaminated groundwater supplies with
uncontaminated groundwater from the groundwater source of Spring Creek on the Lee Mountain
hillside west of Rimini. A minimum of two horizontal well collectors with a combined
capacity of approximately 35 to 50 gallons per minute (gpm) would be installed. In
addition to the well collectors, this alternative would reguire the installation of a
transmission main from the collectors to the community, a water storage tank, and a
distribution system within the community. It is assumed that groundwater from Spring Creek
would not reguire disinfection. If design investigations determine that there was a
possible connection between surface water and groundwater at the Spring Creek source, then
disinfection might be reguired.
Pi mini Water Supply Alternative D
Alternative D would involve replacing contaminated groundwater supplies with
uncontaminated groundwater from deep (more than 200 feet) wells. A minimum of two new
wells, with a combined capacity of approximately 35 to 50 gpm, would be installed. The
wells would be developed in bedrock fractures within 1 mile of Rimini. The final location
of the wells would be determined through a program of test drilling in and around the
community. Similar to Alternative C, this alternative would reguire the installation of a
transmission main from the wells to the community, a distribution system within the
community, and a water storage tank. It is assumed that groundwater from deep wells would
not reguire disinfection.
-------
Table 9-3
Summary Description of Rimini Water Supply Alternatives
Description
O&M Requirements
Monitoring
Requirements
Estimated Total Cost
Schedule
Alternative A
No action
None
None
$0
None
Alternative A
Provide POU treatment
systems for individual
residences
Long-term O&M would
be the responsibility of
individual users
Long-term water quality
monitoring
$400,000
Construction in 3 years;
O&M in perpetuity
Alternative C
Community water
system using the
groundwater of Spring
Creek as the water
source
Long-term O&M would
be the responsibility of
users connected to
system
Long-term water quality
monitoring
$344,000
Construction in 3 years;
O&M in perpetuity
Alternative D
Community system
using new deep wells
as the water source
Long-term O&M would
be the responsibility of
users connected to
system
Long-term water quality
monitoring
$495,000
Construction in 3 years;
O&M in perpetuity
Alternative E
Community system
using treated Rimini
groundwater from
Alternative ADS as the
water source
Long-term O&M would
be the responsibility of
users connected to
system
Long-term water quality
monitoring
$281,000
Construction in 5 years;
O&M in perpetuity
Table 9-3.wpd
-------
Rimini Water Supply Alternative E
Alternative E would involve replacing contaminated groundwater supplies with treated
groundwater from the EPA water treatment facility constructed under Alternative ADS. Thus,
Alternative E cannot be implemented if Alternative ADS is not constructed. This
alternative would take treated water from the EPA groundwater treatment facility and
provide additional treatment (disinfection, pH control), as necessary. In addition to the
intake-treatment facility, this alternative would require the installation of a
transmission main from the facility to the community, a storage tank, and a distribution
system within the community.
-------
Section 10
Summary of Comparative Analysis of Alternatives
Section 300.430(e)(9) of the NCP requires that EPA evaluate and compare the remedial
cleanup alternatives based on the nine criteria listed below. The first two criteria, (1)
overall protection of human health and the environment and (2) compliance with applicable
or relevant and appropriate requirements (ARARs), are threshold criteria that must be met
for the selected remedy. The selected remedy must then represent the best balance of the
remaininq primary balancinq and modifyinq criteria.
10.1 NCP Evaluation and Comparison Criteria
10.1.1 Threshold Criteria
Overall protection of human health and the environment addresses whether or not a remedy
provides adequate protection of human health and the environment and describes how risks
posed throuqh each exposure pathway are eliminated, reduced, or controlled.
Compliance with ARARs addresses whether or not a remedy will comply with identified
federal and state environmental and facility sitinq laws and requlations and/or provide
qrounds for a waiver. Applicable requirements are those cleanup standards, standards of
control, and other substantive requirements, criteria, or limitations promulqated under
federal environmental or state environmental or facility sitinq laws that specifically
address a hazardous substance, pollutant, contaminant, remedial action, location, or other
circumstance found at a CERCLA site. Only those state standards that are identified by a
state in a timely manner and that are more strinqent than federal requirements may be
applicable.
Relevant and appropriate requirements are those cleanup standards, standards of control,
or other substantive requirements, criteria, or limitations promulqated under federal
environmental or state environmental or facility sitinq laws that, while not applicable to
a hazardous substance, pollutant, contaminant, remedial action, location, or other
circumstance at a CERCLA site, address problems or situations sufficiently similar to
those encountered at the CERCLA site that their use is well suited for the particular
site. Only those state standards that are identified in a timely manner and are more
strinqent than federal requirements may be relevant and appropriate.
10.1.2 Primary Balancing Criteria
Long-term effectiveness and permanence refers to expected residual risk and the ability of
a remedy to maintain reliable protection of human health and the environment over time,
once cleanup levels have been met. This criterion includes the adequacy and reliability of
remedial controls.
Reduction of toxicity, mobility, and volume refers to the preference for a remedy that
reduces health hazards, the movement of contaminants, and/ or the quantity of contaminants
at the site throuqh treatment.
Short-term effectiveness addresses the period of time needed to complete the remedy and
any potential adverse effects to human health and the environment that may be caused
durinq the construction and implementation of the remedy.
Implementability refers to the technical and administrative feasibility of the remedy,
includinq the availability of materials and services needed to carry out the remedy and
coordination of federal, state, and local qovernments to work toqether to clean up the
site.
Cost evaluates the estimated capital cost, O&M costs, and present value costs of each
alternative in comparison to other, equally protective measures.
-------
10.1.3 Modifying Criteria
State acceptance indicates whether the state, based on its review of the information,
concurs with, opposes, or has no comment on the alternatives considered or the selected
remedy.
Community acceptance includes determining which components of the alternatives interested
persons in the community support, have reservations about, or oppose.
10.2 Evaluating the Alternatives with the NCP Criteria
This section summarizes the evaluation of the sitewide alternatives against the nine NCP
criteria. Additional details of the evaluation of alternatives are presented in the FS and
the RI/FS addenda.
10.2.1 Comprehensive Sitewide Mine Site Alternatives
This section summarizes the comparative analysis of sitewide alternatives for all media at
the site, including waste rock/tailings, surface water, groundwater, stream sediments,
residential and recreational yards, and roadway materials. The Rimini community water
system alternatives are discussed in Section 10.2.2. Table 10-1 provides a brief summary
of the comparative analysis of the comprehensive remedial alternatives.
10.2.1.1 Alternative 1
Alternative 1 consists of the following components:
No action for all media (WR1, ADI, SW1, SD1, GW1, RY1, RD1)
Alternative 1 would not meet the threshold remedy selection criteria of overall
protectiveness and compliance with ARARs. It would have no long-or short-term
effectiveness and would not reduce contaminant toxicity, mobility, or volume.
10.2.1.2 Alternative 2
Alternative 2 consists of the following components:
• Remove mine wastes to Luttrell repository for category E sites (WR4), cap in place
category D sites (WR3), surface controls for category C sites (WR2), and no action
for category A and B sites (WR1)
• Source control and flow reduction, followed by treatment of adit discharges
(Modified AD4/5)
• Implement groundwater use controls (GW3)
• Remove contaminated residential yards (RY3)
• No action for surface water (SW1), stream sediments (SD1), and roadways (RD1)
Excavation and removal of the contaminated waste rock/ tailings, with disposal at the
Luttrell repository, is considered the most protective approach for dealing with waste
rock/ tailings. This would provide a very protective remedy for category E sites. Capping
in place is considered to be protective for category D sites. Surface controls are
expected to be protective for category C sites, although there is some uncertainty because
of the potential for re- acidification of the wastes (if they are not properly amended)
and elimination of the erosion- protecting vegetation. This alternative would also
effectively remedy all contaminated residential yards at the site. Biological treatment of
AMD would accomplish major reductions of contaminant loading to Tenmile Creek and its
-------
Table 10-1
Comparative Analysis of Sitewide Alternatives
Evaluation Criteria
Overall Protection of
Human Health and the
Environment
Compliance with ARARs
Long-Term Effectiveness
and Permanence
Reduction of Toxicity,
Mobility, and Volume
through Treatment
Short-term Effectiveness
Implementability
Total Present Worth Cost
State Acceptance
Community Acceptance
Alternative 1
No protection of human
health or the
environment from
existing risk.
Standards currently
exceeded in some
surface water and
groundwater.
Not effective.
No reduction in toxicity,
mobility or volume of
waste.
No increase in short-
term risk to
environment or
workers.
No implementation
required.
$0
No comment provided.
No specific comment
provided, although
throughout project the
Upper Tenmile
Watershed group has
recommended cleanup
action.
Alternative 2
Protective of human health and environment for category D and E sites and residential yards.
Protection uncertain for category C and B sites, stream sediments, and groundwater. For surface
water, not fully protective of human health and the environment over the short term; may be
protective over the long term.
May not comply with ARARs. Biological treatment of AMD would accomplish reduction of
contaminant loading to Tenmile Creek and major tributaries, although its ability to meet surface
water quality ARARs is doubtful. Alternative 2 would not remediate the groundwater underlying the
community of Rimini or achieve ambient groundwater standards. May require ARARs waiver.
Effective for category D and E sites and residential yards. Moderately effective for category C
sites. Low to moderate effectiveness for surface water. Long-term effectiveness at category D and
C sites would depend upon proper maintenance. Not effective for roadways. Sediment
effectiveness uncertain. Would require long-term monitoring and institutional controls to maintain
protection as residential or recreational development occurs at sites where wastes are left in place
or with contaminated groundwater.
Moderate reduction in toxicity, mobility and volume over the long term. Biological treatment of
AMD would reduce contaminant loading to Tenmile Creek and major tributaries. Treatment
residual waste disposed in Luttrell repository.
Moderate short-term risk to environment and workers during construction.
Moderately difficult to implement. Acquiring 5 acres of level property in the Rimini area for
biological treatment of adit discharge is uncertain.
$15,158,000
No comment provided.
No comment provided.
Alternative 3
Same as Alternative 2, except greater
protection for category C and D sites.
Same as Alternative 2. May require
ARARs waiver.
Same as Alternative 2, except more
effective for category C and D sites.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
$15,648,000
No comment provided.
No comment provided.
Upper Tenmile Creek ROD.wpd
10-3
-------
Table 10-1 (continued)
Comparative Analysis of Sitewide Alternatives
Evaluation
Criteria
Overall Protection
of Human Health
and the
Environment
Compliance with
ARARs
Long-Term
Effectiveness and
Permanence
Reduction of
Toxicity, Mobility,
and Volume
through Treatment
Short-term
Effectiveness
Implementability
Total Present
Worth Cost
State Acceptance
Community
Acceptance
Alternative 4
Same as Alternative 3, except more protective for
surface water because physical/chemical treatment of
Rimini adits would be more effective than biologic
treatment (contaminant removal efficiencies of 99
percent and discharge compliance with surface water
quality standards). More protective for roadways.
Same as Alternative 3, except more likely to
achieve ARARs since physical/chemical treatment
of AMD in the Rimini area would be effective at
removing contaminants and the treatment plant
discharge would meet all surface water quality
standards. However, uncertain length of time to
achieve surface water ARARs throughout Tenmile
Creek because of additional nonpoint source
contaminant loads (from contaminated groundwater
and stream underflow). May require ARARs waiver.
Same as Alternative 3, except more effective for
roadways. Moderately effective for surface water.
Greater reduction in toxicity, mobility, or volume
than Alternatives 2 or 3 because AMD near Rimini
would be treated using physical/chemical system.
Same as Alternative 3.
More difficult to implement than Alternative 3.
Design studies required to determine best AMD
physical/chemical treatment train. Locating 4 acres
of sludge drying beds near Rimini may be difficult.
$18,195,000
No comment provided.
No comment provided.
Alternative 5, as modified
(Selected Remedy)
Same as Alternative 4, except more
protective for surface water because it would
provide increased volume of clean water
during low flow periods in Tenmile Creek,
when water quality currently is significantly
degraded.
Similar to Alternative 4, except may be
more able to meet surface water quality
ARARs in the Tenmile Creek within a
reasonable time frame because it would
provide increased volume of clean water
during low flow periods, when water quality
currently is significantly degraded. May
require ARARs waiver.
Similar to Alternative 4, except moderately
to highly effective for surface water and
more effective for yard soils and roadway
materials because more materials are
removed.
Same as Alternative 4.
Similar to Alternative 4, except greater
disruption during construction in Rimini
because of greater excavation depth.
More difficult to implement than Alternative
4. Requires development of flow
augmentation protocols for Tenmile Creek.
$22,204,000
Concurrence with selected remedy.
Support for selected remedy; support for
additional water storage component.
Alternative 6
Same as Alternative 5, except also
protective for category B sites.
However, the incrementa
improvement in protectiveness is
not considered significant because
of the relative lack of size and
limited access of the category B
sites.
Same as Alternative 5.
Same as Alternative 5, except also
effective for category B sites.
Same as Alternative 5.
More short-term risk than
Alternative 5 because more sites
addressed.
Slightly more difficult to implement
than Alternative 5 since more mine
sites addressed.
$24,657,000
No comment provided.
No comment provided.
Alternative 7
Same as Alternative 5, except more
protective for surface water because
physical/chemical treatment of all AMD
would be more effective than biologic
treatment (contaminant removal
efficiencies of 99 percent and
discharge compliance with surface
water quality standards).
Same as Alternative 6, except would
provide the highest level of compliance
with ARARs. May require ARARs
waiver.
Same as Alternative 6, except highly
effective for surface water.
Greater reduction in toxicity, mobility,
or volume than other alternatives
because all AMD would be treated by
physical/chemical systems.
Same as Alternative 6.
More difficult to implement than
Alternative 6, since more
physical/chemical treatment systems
built.
$35,31 1 ,000
No comment provided.
No comment provided.
Upper Tenmile Creek ROD.wpd
10-4
-------
major tributaries, although its ability to meet surface water quality ARARs is uncertain.
There would be substantial O&M costs to dispose and replace substrate materials from the
biological treatment systems. Alternative 2 would not remediate the groundwater underlying
the community of Rimini or achieve ambient groundwater standards. It would also not
directly reduce contamination in surface water or instream sediments, although contaminant
levels in these media are expected to be reduced due to the other remedial actions. This
alternative would not be effective for contaminated roadway material.
10.2.1.3 Alternative 3
Alternative 3 consists of the following components:
• Remove mine wastes to Luttrell repository for category D and E sites (WR4), cap in
place category C sites (WR2), and no action for category A and B sites (WR1)
• Source control and flow reduction, followed by treatment of adit discharges
(Modified AD4/5)
• Implement groundwater use controls (GW3)
• Remove contaminated residential yards (RY3)
• No action for surface water (SW1), stream sediments (SD1), and roadways (RD1)
Alternative 3 would provide increased protectiveness relative to mine wastes/ tailings in
comparison to Alternative 2. Category C sites would require long- term monitoring and
institutional controls to ensure that the caps remain effective over time and that
material is excavated and disposed of appropriately if residential or recreational cabin
development occurs. As in Alternative 2, this alternative assumes that biological
treatment of AMD would be implemented, which would be effective at reducing loading to
Tenmile Creek and its tributaries, but may not comply with surface water quality ARARs at
all locations. Alternative 3 would not directly remediate surface water, sediment, roadway
material or the groundwater underlying the community of Rimini or achieve ambient
groundwater standards.
10.2.1.4 Alternative 4
Alternative 4 consists of the following components:
• Remove mine wastes to Luttrell for category C, D, and E sites (WR4) and no action
for category A and B sites (WR1)
• Source control and flow reduction, followed by treatment of adit discharges
(Modified AD4/5)
• Implement groundwater use controls (GW3)
• Remove contaminated residential yards (RY3)
• Remove contaminated roadways (RD3)
• No action for surface water (SW1) and stream sediments (SD1)
Alternative 4 would provide a protective remedy, relative to mine waste/tailings, that
would be effective in both the long-and short-term. It would effectively isolate the most
significant waste piles at the site (wastes at category C, D, and E sites) by placing them
in a lined regional repository with effective leachate control and monitoring.
Physical/chemical treatment of AMD in the Rimini area would be very effective at removing
contaminants; the treatment facility would remove approximately 99 percent of the
-------
contaminant load and the treatment plant discharge would meet all surface water quality
standards. Contaminated stream sediments in the Rimini area that may contribute to
degradation of surface water would be monitored over time and potentially removed, if
determined to be a significant source of metals loading to the stream. However, it is
uncertain how long it would take to achieve surface water ARARs throughout Tenmile Creek,
because there are additional nonpoint source contaminant loads (from contaminated
groundwater and stream underflow) that would still not be addressed. Alternative 4 would
not remediate surface water or sediment directly, or the groundwater underlying the
community of Rimini or achieve ambient groundwater standards. Protectiveness goals for
residential and recreational yards would be met with implementation of Alternative 4. This
alternative would effectively eliminate threats due to contaminated roadway material.
10.2.1.5 Alternative 5 (As Modified)
Alternative 5 (as modified) consists of the following components:
• Remove mine wastes to Luttrell for category C, D, and E sites (WR4) and no action
for category A and B sites (WR1)
• Source control and flow reduction, followed by treatment of adit discharges
(Modified AD4/5)
• Implement groundwater use controls (GW3)
• Construct additional water storage in Chessman Reservoir for flow augmentation (SW3)
• Remove all accessible contaminated yard soils (RY3B), which would likely include
construction of a Rimini community wastewater collection and treatment system
(RY3CS) to replace individual septic systems damaged during the soil excavation
• Remove accessible contaminated roadway materials in Rimini (RD3B)
• No action for stream sediments (SD1)
For mine wastes, AMD, and sediments, Alternative 5 (as modified) would provide the same
level of protection as Alternative 4. Alternative 5 (as modified) would be better able to
meet surface water quality ARARs in Tenmile Creek because it would provide increased
volume of clean water during low flow periods when water quality currently is
significantly degraded, thereby helping to increase fish populations in Tenmile Creek
below Rimini. Like the other alternatives, Alternative 5 would not directly remediate the
instream sediments or groundwater underlying the community of Rimini or achieve ambient
groundwater standards. Protectiveness goals for yard soils and roadway materials would be
met with implementation of Alternative 5 (as modified). At $22,204,000 (assuming that the
contingent Rimini community wastewater system would be required), this alternative is
approximately 25 percent more expensive than Alternative 4 and approximately 45 percent
more expensive than Alternatives 2 and 3. This alternative is acceptable by the State of
Montana, Lewis and Clark County, the City of Helena, and has a high level of support from
the Rimini community.
10.2.1.6 Alternative 6
Alternative 6 consists of the following components:
• Remove mine wastes to Luttrell repository for category C, D, and E sites (WR4), cap
in place category B sites (WR3), and no action for category A sites (WR1)
• Source controls and flow reduction, followed by treatment of adit discharges
(Modified AD4/5)
• Implement groundwater use controls (GW3)
-------
• Remove Tenmile Creek sediments (SW3) for Rimini area only, with no sediment action
for other stream reaches (SD1)
• Construct additional water storage in Chessman Reservoir for flow augmentation (SW3)
• Remove contaminated residential yards (RY3)
• Remove contaminated roadways (RD3)
This alternative would comply with most ARARs and would provide increased protectiveness
by addressing the additional category B sites. However, the incremental improvement in
protectiveness is not considered significant because of the relative lack of size and
limited access to the category B sites. Removing contaminated sediments in the Rimini area
would be expected to improve water guality in Tenmile Creek in that area, but the degree
of improvement is difficult to guantify because the other contaminant sources in Rimini
currently dominate the loading to the creek. Alternative 6 would not remediate the
groundwater underlying the community of Rimini or achieve ambient groundwater standards.
10.2.1.7 Alternative 7
Alternative 7 consists of the following components:
• Remove mine wastes to Luttrell repository for category B, C, D, and E sites (WR4)
and no action for category A sites (WR1)
• Source control and flow reduction, followed by treatment of adit discharges
(Modified AD4/5)
• Implement groundwater use controls (GW3)
• Remove Tenmile Creek sediments for Rimini area and the mainstem below Rimini to
Walker Creek (SD3)
• Construct additional water storage in Chessman Reservoir for flow augmentation (SW3)
• Remove contaminated residential yards (RY3)
• Remove contaminated roadways (RD3)
Alternative 7 provides the highest level of protection and compliance with ARARs of all
the alternatives. By excavating and removing mine wastes/tailings at all Category B, C, D,
and E sites, nearly all significant waste materials at the site would be placed in the
secure Luttrell repository. Physical/chemical treatment of all AMD would be very effective
(contaminant removal efficiencies of 99 percent and discharge compliance with surface
water guality standards) , but the costs would be high. Long-term operation and maintenance
costs would be significant. Alternative 7 would not remediate the groundwater underlying
the community of Rimini or achieve ambient groundwater standards. Alternative 7 would be
protective for residential yard and roadway materials cleanup. Stream sediments would be
removed, eliminating this potential pathway for loading to Tenmile Creek surface water.
10.2.2 Rimini Water Supply Alternatives
This section summarizes the comparative analysis of the alternatives considered for
developing a community water system in Rimini. Table 10- 2 provides a brief summary of the
comparative analysis of the mine site remedial alternatives.
10.2.2.1 Rimini Water Supply Alternative A
Alternative A consists of the following components:
-------
Table 10-2
Comparative Analysis of Rimini Water Supply Alternatives
EVALUATION CRITERIA
Overall Protection of Human
Health and the Environment
Compliance with ARARs
Long-Term Effectiveness
and Permanence
Reduction of Toxicity, Mobility,
and Volume through Treatment
Short-term Effectiveness
Implementability
Total Present Worth Cost
State Acceptance
Community Acceptance
ALTERNATIVE
Alternative A
No protection of
human health or
the environment
from existing risk.
Standards
exceeded in some
drinking water
supplies.
Not effective.
No reduction in
toxicity, mobility or
volume of waste.
No change in
short-term risk to
environment or
workers.
No
implementation
required.
$0
No comment
provided.
No support.
Alternative B
Protective of human health.
Complies with drinking water system
ARARs.
Long-term effectiveness uncertain.
Effectiveness relies on individual
homeowners conducting routine
maintenance on their systems, such as
regularly replacing filters. No effective
mechanism for EPA to ensure that all
POU systems are maintained by
homeowners.
Same as Alternative A. Contaminants
removed from the drinking water supply
at an individual house would be returned
to the site soils and groundwater during
system backwash, using the individual
wastewater disposal system for the
house.
Minimal increase in short-term risk to
environment or workers.
Minimally difficult to implement.
$400,000
No comment provided.
Acceptable to community.
Alternative C
Same as Alternative B. Would eliminate
exposure pathway for contaminated
groundwater for all residences
connected to the community system.
Same as Alternative B.
Effective in the long term. More
effective than Alternative B.
Does not treat contaminated
groundwater.
Moderate increase in short-term risk to
environment and workers during
construction.
Moderately difficult to implement. It
may not be possible to obtain water
rights to use Spring Creek water.
$344,000
No comment provided.
No comment provided.
Alternative D
Selected Remedy
Same as Alternative C.
Same as Alternative C.
Same as Alternative C.
Same as Alternative C.
Same as Alternative C.
Same as Alternative C.
Design study required to
locate adequate water
source.
$495,000
Concurs with selected
remedy.
Supports alternative.
Alternative E
Same as Alternative D.
Same as Alternative D.
Same as Alternative D. Although
there may be variations in the
discharge flows being produced by
the EPA treatment plant, the
projected flows would always be
adequate to meet the source flow
requirements for the community of
Rimini.
Contaminants are removed from
groundwater during treatment for
the Rimini water system and then
placed in the secure Luttrell
repository.
Same as Alternative D.
Same as Alternative D. Depends
upon construction of Rimini
groundwater treatment system.
Has highest O&M costs for system
users of any alternative.
$281 ,000
Does not support alternative.
No comment provided.
Note:'
be part of EPA's remedial action.
Upper Tenmile Creek ROD.wpd
10-10
-------
• No action
Alternative A would not meet the threshold remedy selection criteria of overall
protectiveness and compliance with ARARs. It would have no long- or short- term
effectiveness and would not reduce contaminant toxicity, mobility, or volume.
10.2.2.2 Rimini Water Supply Alternative B
Alternative B consists of the following components:
• Provide POU treatment systems for individual residences
Alternative B would treat the water to standards reguired for consumption, so it would be
protective of human health. If maintained reliably, the POU systems would be effective in
the long-term. However, effective application of this technology reguires that individual
homeowners conduct routine maintenance on their systems, such as regularly replacing
filters. There is no effective mechanism to ensure that all POU systems are reliably
maintained by the homeowners. From an environmental viewpoint, there would be no reduction
in overall toxicity, mobility, and volume of contaminants because all contaminants removed
from the drinking water supply at an individual house would be returned to the site soils
and groundwater during system backwash (through the individual wastewater disposal system
for the house).
10.2.2.3 Rimini Water Supply Alternative C
Alternative C consists of the following components:
• Construct a community water system and use the groundwater of Spring Creek as the
source of water
This alternative would be protective of human health. It would eliminate the exposure
pathway for consuming contaminated groundwater for all residences connected to the
community system. There would be moderate short-term risks during construction of the
system, but in the long-term it would be effective. The cost for this alternative is
moderately high.
10.2.2.4 Rimini Water Supply Alternative D
Alternative D consists of the following components:
• Construct a community water system using deep wells as the source of water
Alternative D would be protective of human health; it would eliminate the exposure pathway
for consuming contaminated groundwater for all residences connected to the community
system. There would be moderate short-term risks during construction of the system, but,
in the long term, it would be effective. This alternative has the highest cost of any of
the Rimini water supply alternatives because it is expected to reguire considerable
exploratory drilling to locate a water source of adeguate guality and guantity.
10.2.2.5 Rimini Water Supply Alternative E
Alternative E consists of the following components:
• Construct a community water system using treated Rimini groundwater from alternative
ADS as the source of water
Alternative E would be protective of human health and is expected to be effective in the
long-term. Although there may be variations in the discharge flows being produced by the
EPA treatment plant, the projected flows would always be adeguate to meet the source flow
reguirements for the community of Rimini. There would be some adverse short-term impacts
-------
during construction, but those impacts are not expected to be major. This alternative is
less costly than Alternatives C and D because it does not require construction of
facilities to develop a water source, but rather relies on water already treated in the
community of Rimini as its water source.
-------
Section 11
Principal Threat Wastes
The NCP establishes an expectation that EPA will use treatment to address the principal
threats posed by the site wherever practicable (NCP §300.430 (a)(1)(iii)(A)). Identifying
principal threat wastes combines concepts of both hazard and risk. In general, principal
threat wastes are those source materials considered to be highly toxic or highly mobile
that generally cannot be contained in a reliable manner or that would present a
significant risk to human health or the environment should exposure occur. Conversely,
non-principal threat wastes are those source materials that generally can be reliably
contained and that would present less risk in the event of exposure. The manner in which
principal threats are addressed typically will determine whether the statutory preference
for treatment as a principal element is satisfied.
The source materials identified at the site include contaminated waste rock, tailings, and
adit discharge waters at historic abandoned or inactive mine sites. Contaminated media at
the site include waste rock/tailings, groundwater, surface water, stream sediments, yard
soils at residences and occasional-use recreational cabins, and roadway materials within
the community of Rimini. Most of the source materials and media at the site (including all
of the contaminated solid media ) do not present principal threats and are therefore
considered non-principal threat wastes. Containment of the solid media source materials
using a repository and soil covers is a reliable remedy.
However, several adits in the Rimini area (Susie, Lee Mountain, and Red Water) discharge
waters that are highly contaminated with arsenic, lead, or zinc. Those waters could be
considered highly mobile and toxic, and it is likely that not all of these discharges can
be contained in a reliable manner. EPA considers these specific adit discharges to be
principal threat wastes. All sitewide alternatives discussed in Sections 9 and 10 would
address these wastes through the four-phase remedy for AMD. EPA's initial effort will be
to reduce the volume of wastes through source control and adit discharge flow reduction
technigues. EPA will subseguently employ appropriate treatment technologies, determined in
consultation with DEQ, to further reduce loading from these sources. The four- phase
remedy of source control and treatment of the Rimini-area adit discharge waters fulfills
the reguirement for use of treatment for principal threat wastes at the site.
-------
Section 12
Selected Remedy
Based upon consideration of CERCLA requirements, the detailed analysis of alternatives,
and public comments, EPA has determined that the preferred remedial alternatives presented
in the proposed plan, sitewide Alternative 5 (as modified) and Rimini water supply
Alternative D are the appropriate remedies for the site.
12.1 Rationale for Selected Remedy
This selected remedy, which is supported by the State of Montana, Lewis and Clark County,
the City of Helena, and residents of the community of Rimini, will reduce risk to human
health and the environment through the following:
• As required, the selected remedy will meet the threshold cleanup evaluation criteria
(overall protection of human health and the environment and compliance with ARARs,
unless an ARAR waiver is ultimately determined necessary and appropriate). Overall
protection of human health and the environment is accomplished through removal of
contaminated mine wastes, yard soils, and roadway materials, reduction of flow and
treatment of AMD to human health-and ecological-based concentrations, implementation
of institutional controls to prevent the use of contaminated aquifers for drinking
water purposes, and construction of a reliable deep well water supply system for the
community of Rimini. The selected remedy is more protective for surface water than
other alternatives because it would provide the increased volume of clean water
during low flow periods in Tenmile Creek. This would complement the cleanup of
contaminated mine waste and AMD in order to achieve water quality improvements
sufficient to support the Tenmile Creek trout fishery.
• The selected remedy removes or addresses the principal contaminant sources at the
site.
• The selected remedy provides very good long- term effectiveness and permanence
because excavated wastes will be permanently isolated in a secure engineered
repository. Long-term reductions in AMD metals loading will be achieved through a
four-phase approach using source control and flow reduction, followed by treatment
if necessary to meet ambient surface water quality ARARs. The water supply system
for the community of Rimini will provide a long- term and reliable source of
uncontaminated drinking water.
• The selected remedy is readily implementable. The remediation technologies selected
for this alternative have been successfully employed at other Superfund sites.
Design studies will be required to determine the best methods (technologies) to
control contaminant sources, reduce AMD flows, and provide for passive biological or
physical/ chemical treatment of residual AMD flows, where flow reduction and source
controls cannot address the discharges adequately.
The selected remedy best meets the entire range of selection criteria and achieves, in
EPA's determination, the appropriate balance considering site-specific conditions and
criteria identified in CERCLA and the NCP (additional documentation is provided in Section
13) .
12.2 Description of Selected Remedy
The selected remedy is outlined below. Details of the selected remedy may be modified
somewhat as a result of the remedial design and construction processes. Minor design
changes will be documented using technical design memoranda. Any substantive modifications
to the selected remedy would be documented through an explanation of significant
differences or ROD amendment, in accordance with the NCP and EPA guidance.
-------
Waste Rock and Tailings
• Approximately 245,000 cubic yards of contaminated material will be excavated from 70
category C, D, and E high priority mine sites. Excavated wastes will be disposed of
in the Luttrell repository. Excavated areas will be backfilled with clean soils to
appropriate slope contours and revegetated. No action is expected to be taken at the
remaining 80 Category A and B mine low priority sites (which contain approximately
95,000 cubic yards of waste rock materials).
• During detailed remedial design, EPA will collect additional site data for specific
mine sites. Each site will be reevaluated and rescored based on all current data;
the relative ranking and categories of some sites may change if new site data
indicate changes in site conditions.
• Institutional controls will be implemented using mechanisms available through Lewis
and Clark County to provide information to current and future property owners
regarding any inaccessible wastes that may remain on site with concentrations of
contaminants above cleanup action levels. The property owners will be provided
information about requirements for excavating and maintaining remediated properties.
• The Luttrell repository could continue to be used for the disposal of wastes from
the site. A portion of the repository may remain available in the long- term for
disposal of nonhazardous water treatment sludges/spent media and mining wastes
excavated to accommodate future residential, recreational, or commercial
development.
• Consistent with the need to provide continued wildlife security in Tenmile Creek
watershed, EPA will minimize the construction or widening of access roads necessary
to implement its waste rock and tailings removal actions. All road improvements will
be designed in consultation with the USFS, DFWP, and local property owners and will
be consistent with overall land management and traffic plans of the USFS, to the
extent practicable. After remedial construction is complete, EPA will return access
roads to pre-remedial conditions to the extent possible, while retaining drainage
improvements. Where new access roads are necessary, EPA will generally remove them
after implementation of the remedial action.
Luttrell Repository
• The Luttrell repository, which will receive all solid media mining wastes from the
site, incorporates both cover and bottom liners. The cover consists of a
geosynthetic clay liner (GCL), a 60-mil textured high density polyethylene
geomembrane, 12-inch drainage, 24-inch thermal barrier, and 6-inch vegetation
support layers, and vegetation. The bottom liner consists of 60-mil geomembrane and
a GCL to minimize infiltration through the bottom of the pit.
• The first three of an estimated six repository cells have been constructed and
partially filled during prior removal actions at the site. The overall repository
conceptual design can accommodate approximately 2.5 million cy of mine wastes, but
the repository has the flexibility to receive and be closed with as little as
600,000 cy. At the former capacity, the maximum depth of wastes in the repository
would be approximately 120 feet. The final closure configuration of the repository
will depend on the final volume of waste deposited. The final configuration will be
contoured to allow for natural drainage of precipitation runoff from the repository.
• Leachate from the repository will be collected by a leachate collection, treatment,
and discharge system. The collection system includes a 12-inch thick permeable
drainage layer and leachate collection pipes above the bottom liner. Collected
leachate will be treated in either a passive biological or conventional treatment
system (depending on the results of ongoing treatability tests) prior to land
application disposal (LAD) on forested land southeast of the repository or will be
-------
treated or disposed in another appropriate manner in accordance with ARARs.
Acid Mine Drainage
• Collapsed shafts/adits will be capped and regraded and drainage features will be
constructed to prevent or reduce storm water and snowmelt from entering mine
workings and contributing to AMD. Design investigations will be conducted to
determine potential effectiveness of additional measures, such as the grouting of
mine workings, to reduce the guantity of AMD.
• All discharging adits will be evaluated in a four-phase program to develop and
implement practicable cost-effective control measures to eliminate AMD from existing
mine adits and attain compliance with state water guality standards in Tenmile Creek
and its tributaries. The program, conducted by EPA in consultation with DEQ, will
begin with full evaluation and pilot studies of source control and flow reduction
technologies to minimize the need for and size of long-term AMD treatment
facilities.
After all appropriate efforts to implement source controls and flow reduction have been
implemented, EPA, in consultation with DEQ, will evaluate and select appropriate
facilities to treat residual mine adit dischargesbased on specific flow rates and water
chemistries. EPA will then design and build the AMD treatment facilities necessary to meet
state ambient water guality standards.
• In addition to determining treatment needs for major sources of AMD (described
above), and after collecting additional adit discharge data and considering
potential flow reduction options, EPA, in consultation with DEQ, will reevaluate the
contaminant loadings from small adit discharges relative to potential adverse
environmental impacts that would result from developing access and constructing
treatment facilities. At that time, EPA may determine, in consultation with DEQ,
USFS, and property owners, that adit discharges at remote, roadless locations with
minimal loadings to the streams may appropriately be left undisturbed.
• EPA anticipates that treatment for many of the AMD sites, at remotely located sites
having low flow rates and loadings, will consist of low cost, low maintenance
biological treatment systems (probably utilizing enhanced sulfate- reducing
bacteria, oxidation, and constructed wetlands, with additional treatment polishing
components) or other in- situ treatment systems.
Groundwater
• The selected remedy, including removal of waste rock/tailings source areas and the
four-phase program to reduce loading from AMD, is expected to result in significant
improvements in overall groundwater guality. The time frame reguired to attain
ambient groundwater standards is uncertain. EPA will monitor groundwater guality
improvements relative to the performance standards identified in this ROD through
several five-year review cycles, conduct additional source control actions as
appropriate, and then make a determination whether waiver of the state ambient
groundwater standards is necessary and appropriate, in accordance with Section 12.7,
Remedy Contingencies.
• The selected remedy provides for the implementation of institutional controls to
prevent the installation and use of new drinking water wells where contaminated
aguifers exist. Under Montana Code Annotated §85-2-501, a controlled groundwater
area may be designated if 1) excessive groundwater withdrawals would cause
contaminant migration, 2) groundwater withdrawals are occurring or likely to occur
that adversely affect groundwater guality within the groundwater area, or 3)
groundwater guality within the groundwater area is not suited for a specific
beneficial use. DNRC may designate either a permanent or a temporary controlled
groundwater area. EPA will coordinate with the Lewis and Clark County health
-------
department and DNRC in establishing an appropriate controlled groundwater area. EPA
does not expect that the controlled groundwater area will prohibit new irrigation
wells or reguire discontinuation of the use of existing wells for irrigation
purposes.
Surface Water
• EPA will augment flows in Tenmile Creek by constructing improvements to Chessman
Reservoir and the Red Mountain flume to provide for an additional 500 acre-feet of
storage in the reservoir. EPA, in consultation with DEQ, will negotiate with water
right holders to find appropriate water management approaches to augment stream flow
in critical reaches of Tenmile Creek. The additional stored water would be available
to the City of Helena to offset water the city would allow to bypass the Helena
intake structure in Tenmile Creek above Rimini. The bypassed water could augment
stream flow in Tenmile Creek in and below Rimini during the late summer and early
fall low-flow periods in order to improve water guality. The bypassed water could
come from both the natural flows of upper Tenmile Creek and Banner Creek and stored
water in Scott Reservoir.
• Source control actions for waste rock and tailings and AMD, augmented stream flows
during low-flow periods, and natural attenuation of contaminants in surface water
are expected to achieve surface water remedial action goals within a reasonable time
frame. Because there are nonpoint source contaminant loads at several locations in
the watershed (for example, from contaminated groundwater) that will not be
addressed directly by the selected remedy. EPA will establish and operate a long-
term program for monitoring surface water guality at key locations within the
watershed. At each five-year review period, EPA will evaluate improvements in
surface water guality relative to the performance standards identified in this ROD
and make a determination whether additional source control measures are necessary or
warranted to attain the surface water ARARs. If, after several five-year review
cycles, EPA determines that it is not possible to attain surface water ARARs for
certain parameters (for example, for cadmium or zinc), then EPA, in consultation
with DEQ, will at that time consider waiving pertinent surface water ARARs in
accordance with Section 12.7, Remedy Contingencies.
Stream Sediments
• Water guality and sediment guality will be monitored in Tenmile Creek after waste
rock/tailings and AMD cleanup actions are complete. After additional monitoring and
evaluation, if sediments in specific stream reaches are determined responsible for
unacceptable metal loading to surface water, then those sediments will be excavated
and disposed of at the Luttrell repository.
Contaminated Yard Soils
• All accessible soils in yards at residences and occasional-use recreational cabins
containing contaminant concentrations above cleanup levels will be excavated and
disposed of in the Luttrell repository. Excavated areas will then be restored to
pre-removal conditions by backfilling with clean soils, reseeding or sodding, and
fencing. Shrubs, trees, and other residential yard features will be maintained or
replaced in consultation with the landowner. A contingency remedy element of
constructing a community wastewater collection and treatment system to replace
individual septic systems damaged or removed during the excavation of contaminated
yard soils is discussed in Section 12.7 below (see subsection "Rimini Community
Wastewater System").
• Institutional controls will be implemented through Lewis and Clark County to provide
information to current and future property owners regarding any inaccessible wastes
that may remain on site with concentrations of contaminants above cleanup action
levels. The property owners will be provided information about reguirements for
-------
excavating and maintaining remediated properties.
Contaminated Roadway Materials
• Contaminated roadway materials will be excavated and disposed of in the Luttrell
repository. Approximately 5,000 feet of roadway through the community of Rimini will
be addressed.
Pi mini Water Supply
• EPA will construct a new community water system for Rimini residents. The source of
water for the community system will be new deep wells installed near Rimini. The
system will include water storage and distribution and will have the capacity to
serve approximately 50 residences. With 35 connections, the cost of water to Rimini
community system users would be comparable to the costs borne by rate payers on the
Helena water system. Contingencies for this aspect of the remedy are discussed in
Section 12.7 below (see discussion under "Rimini Community Water System").
12.3 Estimated Remedy Costs
A summary of the capital, operations and maintenance, and periodic costs for the sitewide
selected remedy is provided in Tables 12-1 and 12-2. The 30-year present value analysis is
summarized in Table 12-3. Detailed summaries of the estimated capital costs of the
selected remedy are presented in Appendix B. A summary of the capital, O&M, and periodic
costs for the Rimini water supply selected remedy is provided in Table 12-4 and the
30-year present value analysis is summarized in Table 12-5. Figure 12-1 provides EPA's
estimate of the yearly revenue necessary to operate and maintain the Rimini community
water system and the projected annual cost to individual water users connected to the
system. Yearly revenue is based on the current City of Helena water rate of $2.14 per 100
cubic feet (748 gallons) and $2.00 per month basic service fee. It is assumed that the
average household has three people. Costs and revenues shown in Figure 12-1 are based on
an assumed average household consumption of either 50 or 100 gallons per day per
person. Typical water consumption in Helena ranges from 100 to 200 gallons per day per
person. Assuming that many residents in Rimini would choose to limit water consumption,
EPA has estimated somewhat lower average consumption. A summary of the capital, O&M, and
periodic costs for the contingent Rimini community wastewater treatment system is provided
in Table 12-6 and the 30-year present value analysis is summarized in Table 12-7. Yearly
revenue necessary to operate the community wastewater system and the annual cost to users
connected to the system are expected to be similar to the costs estimated for the
community water system.
The net present value of the estimated capital and operating cost for a 30-year period is
approximately $21,511,000 for the sitewide remedy, $495,000 for the Rimini community water
system, and $693,000 for the contingent Rimini community wastewater system. Therefore, if
all elements of the remedy for the site are constructed, including the contingency
wastewater system, the total remedy present value would be approximately $22,699,000. The
time frame to implement the remedy is anticipated to be 5 to 10 years. These cost
estimates are based on the best available information regarding the anticipated scope of
the remedial alternative. This is a feasibility-level engineering cost estimate expected
to be within +50 to -30 percent of the actual project cost. Changes in the cost elements
are likely to occur as a result of new information and data collected during the
engineering design of the remedial alternative.
12.4 Operations and Maintenance Requirements
The selected remedy includes a number of components that will reguire either short- term
or long-term O&M. This section defines the O&M reguirements of the remedy. CERCLA and the
NCP specify that Fund- financed remedial actions cannot be undertaken unless affected
states provide assurances to EPA to provide 10 percent of the costs for remedial action
-------
Section 12
Selected Remedy
Table 12-1
Summary of Estimated Capital Costs for Sitewide Selected Remedy
Remedy Component
Waste Rock
Category A and B sites (no action)
Category C sites (remove to Luttrell repository)
Category D sites (remove to Luttrell repository)
Category E sites (removal to Luttrell repository)
Subtotal
AMD
Four-phase program, assumed physical/chemical treatment
for 3 Rimini-area adits, biological treatment for all other adits
Cost
$4,151,508
$867,365
$3,306,162
$8,325,034
$8,546,557
Sediments
No action
Surface Water
Expand Chessman Reservoir
Ground Water
Ground Water Use Controls
Residential Yards
Remove to Repository
Roadway Materials
Remove to Repository
Total Capital Costs
$4,232,017
$15,000
$2,123,194
$1,121,631
$24,363,434
Upper Tenmile Creek ROD.wpd 12-8
-------
Section 12
Selected Remedy
Table 12-2
Summary of Estimated Post-Construction
Costs for Sitewide Selected Remedy
Item Unit Unit
Waste Rock (EPA, years 1-9 [prorated]; State of Montana, years 10-30)
Category C site inspections hr $
Category D site inspections hr $
Category E site inspections hr $
Site maintenance Is $ 7,
Cost Quantity Cost
25.00 80 $2,000
25.00 22 $550
25.00 38 $950
000.00 1 $7,000
Sample analysis ea $ 250.00 15 $3,750
Subtotal
O&M contingencies 25%
Waste Rock Annual Post-Construction
Cost
$14,250
$3,563
$17,813
Acid Mine Drainage (EPA, years 7-19 [prorated]; State of Montana, years 20-30)
Site inspections hr $
Site maintenance Is $ 7,
Lime softening gpm $
Reverse osmosis treatment facility gpm $
Substrate removal and disposal at Luttrel cy $
Replace substrate (1/15 per year) ac $48,
Sludge removal and disposal at Luttrell cy $
Sludge stabilization cy $
25.00 656 $16,400
000.00 1 $7,000
315.36 35 $11,038
525.60 35 $18,396
15.00 516 $7,744
000.00 0.11 $5,120
15.00 154 $2,315
37.35 154 $5,764
Sample analysis ea $ 250.00 166 $41,500
Subtotal
O&M contingencies 25%
Acid Mine Drainage Annual Post-
Construction Cost
Luttrell Repository (EPA, years 1-9 [prorated]; State of Montana, years
10-30)
Repository inspections hr $
Leachate treatment gal $
Repairs and supplies Is $10,
Subtotal
O&M contingencies 25%
Luttrell Repository Annual Post-
Construction Cost
Sediment (EPA, annually years 1-9, then years 15, 20, 25, 30)
Sediment sampling hr $
$115,000
$28,819
$144,096
25.00 48 $1,200
0.31 12754 $3,915
000.00 1 $10,000
$15,115
$3,779
$18,894
25.00 32 $800
Sample analysis Is $ 250.00 10 $2,500
Subtotal
O&M contingencies 25%
Sediment Annual Post-Construction Cost
$3,300
$825
$4,125
Upper Tenmile Creek ROD.wpd
12-9
-------
Section 12
Selected Remedy
Table 12-2 (continued)
Summary of Estimated Post-Construction
Costs for Sitewide Selected Remedy
Item Unit Unit
Surface Water (EPA, annually years 1-9, then years 15, 20, 25, 30)
Stream sampling hr $
Cost Quantity Cost
25.00 64 $1,600
Sample analysis Is $ 250.00 20 $5,000
Subtotal
O&M contingencies 25%
Surface Water Annual Post-Construction
Cost
Groundwater (EPA, annually years 1-9, then years 15, 20, 25, 30)
Inspections and sampling hr $
$6,600
$1,650
$8,250
25.00 8 $200
Sample analysis ea $ 250.00 10 $250
Subtotal
O&M contingencies 25%
Groundwater Monitoring Annual Post-
Construction Cost
Residential Yards and Roadway Materials
Included in Waste Rock and Luttrell
Repository Categories
Five-Year Reviews (EPA)
$2,700
$675
$3,375
Five-Year Review Is $50,000.00 1 $50,000
Contingencies 25%
Total EPA Five-Year Review Costs
$12,500
$62,500
Upper Tenmile Creek ROD.wpd
12-10
-------
Section 12
Selected Remedy
Table 12-3
30-Year Present Value Analysis for Sitewide Selected Remedy
Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Totals
PV:
Capital
Costs
$5,092,329
$3,948,512
$3,948,512
$1 ,832,503
$1 ,832,503
$1 ,832,503
$1,469,143
$1,469,143
$1,469,143
$1,469,143
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$24,363,434
$19,979,536
Montana
O&M Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$36,707
$36,707
$36,707
$36,707
$36,707
$36,707
$36,707
$36,707
$36,707
$36,707
$180,803
$180,803
$180,803
$180,803
$180,803
$180,803
$180,803
$180,803
$180,803
$180,803
$180,803
$2,355,903
$515,090
EPA
Post-
Construction
Costs
$0
$18,791
$21 ,832
$24,873
$27,913
$30,954
$33,995
$73,060
$112,125
$151,190
$144,096
$144,096
$144,096
$144,096
$144,096
$144,096
$144,096
$144,096
$144,096
$144,096
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$1 ,935,693
$866,425
Periodic
Costs
(EPA)
$0
$0
$0
$0
$0
$62,500
$0
$0
$0
$0
$62,500
$0
$0
$0
$0
$78,250
$0
$0
$0
$0
$78,250
$0
$0
$0
$0
$78,250
$0
$0
$0
$0
$78,250
$438,000
$149,605
Total Annual
Expenditures
$5,092,329
$3,967,303
$3,970,344
$1,857,376
$1,860,417
$1,925,958
$1,503,138
$1,542,203
$1,581,268
$1,620,333
$243,303
$180,803
$180,803
$180,803
$180,803
$259,053
$180,803
$180,803
$180,803
$180,803
$259,053
$180,803
$180,803
$180,803
$180,803
$259,053
$180,803
$180,803
$180,803
$180,803
$259,053
$29,093,182
$21,510,655
Discount
Factor
(7%)
1.0000
0.9346
0.8734
0.8163
0.7629
0.7130
0.6663
0.6227
0.5820
0.5439
0.5083
0.4751
0.4440
0.4150
0.3878
0.3624
0.3387
0.3166
0.2959
0.2765
0.2584
0.2415
0.2257
0.2109
0.1971
0.1842
0.1722
0.1609
0.1504
0.1406
0.1314
Present
Value
$5,092,329
$3,707,841
$3,467,698
$1,516,176
$1,419,312
$1 ,373,208
$1 ,001 ,541
$960,330
$920,298
$881 ,299
$123,671
$85,900
$80,277
$75,033
$70,115
$93,881
$61 ,238
$57,242
$53,500
$49,992
$66,939
$43,664
$40,807
$38,131
$35,636
$47,718
$31,134
$29,091
$27,193
$25,421
$34,040
$21,510,655
Present Values
Years 0-10
Years 11 -30
Total
$19,979,536
$0
$19,979,536
$95,166
$419,924
$515,090
$689,518
$176,907
$866,425
$104,689
$44,916
$149,605
$20,868,908
$641 ,747
$21,510,655
Notes:
1 Capital Costs for waste rock are assumed to occur over a 10-year period
2 Total annual expenditures is not discounted
3 Present value is calculated using a 7 percent discount rate
Upper Tenmile Creek ROD.wpd
12-11
-------
Section 12
Selected Remedy
Table 12-4
Summary of Estimated Capital and Post-Construction Costs
for Rimini Community Water System Selected Remedy
Remedy Component Unit Unit
Cost Quantity Cost
Capital Costs
Community water supply wells each $15,000.00 2 $30,000
Community well pump and pitless adapter each $8,000.00 2 $16,000
Electric power line If $10.00 500 $5,000
4" transmission main If $5.87 1000 $5,870
50,000 gallon storage tank Is $50,000.00 1 $50,000
6" distribution main If $7.77 3000 $23,310
Service connection including meters each $1 ,000.00 35 $35,000
Site fencing If $20.35 400 $8,140
Subtotal $173,320
Mobilization/Demobilization, Bonding, and Insurance 8.00%
Construction Contingencies 30.00%
Subtotal
Project Management 8.00%
Additional Source Water Investigation Is
Remedial Design 15.00%
Construction Management 10.00%
Subtotal
Total Capital Costs
$13,866
$51 ,996
$239,182
$19,135
$150,000
$35,877
$23,918
$228,930
$468,112
Annual O&M Costs (System users, years 0-30)
System Operation hr $25.00 208 $5,200
Power kwh $0.12 9609 $1,153
Materials and Supplies Is $2,000.00 1 $2,000
Sample Analysis Is $1,500.00 1 $1,500
Subtotal $9,853
O&M Contingencies 25.00% $2,463
Total Annual O&M Costs
$12,316
Five-Year Review Costs (EPA)
Five-Year Review Is $10,000.00 1 $10,000
Contingencies 25.00% $2,500
Total EPA Five-Year Costs
$12,500
Notes:
1. System users' O&M identified for information only; not considered part of present worth of remedial action.
Upper Tenmile Creek ROD.wpd
12-12
-------
Section 12
Selected Remedy
Table 12-5
30-Year Present Value Analysis for Rimini
Community Water System Selected Remedy
Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Totals
Present Value
Capital
Costs
$468,112
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$468,112
$468,112
System
User O&M
Costs 1
$0
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$12,316
$369,489
$152,828
EPA
Post-
Construction
Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
Five Year
Review
Costs
(EPA)
$0
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$75,000
$26,971
EPA
Total Annual
Expenditures
$468,112
$12,500
$12,500
$12,500
$12,500
$12,500
$12,500
$543,112
Discount
Factor (7%)
1.0000
0.9346
0.8734
0.8163
0.7629
0.7130
0.6663
0.6227
0.5820
0.5439
0.5083
0.4751
0.4440
0.4150
0.3878
0.3624
0.3387
0.3166
0.2959
0.2765
0.2584
0.2415
0.2257
0.2109
0.1971
0.1842
0.1722
0.1609
0.1504
0.1406
0.1314
Present
Value
$468,112
$8,913
$6,354
$4,530
$3,230
$2,303
$1 ,643
$495,085
$495,085
Notes:
1. System users' O&M identified for information only; not considered part of present worth of remedial action.
Upper Tenmile Creek ROD.wpd
12-13
-------
Section 12
Selected Remedy
Figure 12-1
Rimini Community Water System Selected Remedy Costs
Estimated Annual O&M Costs and Revenues
Estimated Yearly O&M Cost and Revenue
Consumption R»te= 50 Gallon* per PtrwnperDiy
15 ZO 25 30 35 40
Nymber of Hookups
- Yearly O&M Cosl I
i
- Yearly Revenue at City Rate,
$15--Q5 pet
I
45 50
Estimated Yearly Q&M arid R»vsnua
Consumption Raw * 100 Gallons per Person per Day
15 20 25 30 35 40
Number of Hookups
-Yearly OfiM Cost
1
45
50
Rfi«nue at City Rale
$25,10 per month) j
Upper Tenmile Creek ROD.wpd
12-14
-------
Section 12
Selected Remedy
Table 12-6
Summary of Estimated Capital and Post-Construction Costs
for Rimini Community Wastewater System Contingency Remedy
Remedy Component Unit Unite
Capital Costs
Connect to existing household sewer each
4" sewer service If
8" gravity sewer If
Dost Quantity Cost
$500.00 352 $17,800
$25.00 3500 $87,500
$25.00 3500 $87,500
48" manholes ea $2,000.00 10 $20,000
8,000 gallon septic tank Is $8,000.00 1 $8,000
1,800 ft2 sand filter system (with tank/pump) Is $70,000.00 1 $70,000
Pressure dosed drainfield If
Creek crossing Isum $
Tree removal Is $
Mobilization/Demobilization, Bonding, and
Insurance 8.00%
Construction Contingencies 30.00%
Project Management 8.00%
Additional Pre-Design Investigation Is
Remedial Design 15.00%
Construction Management 10.00%
Total Capital Costs
Annual Operation and Maintenance Costs (System Users years 1-30) 1
System Operation hr
Power kwh
$20.00 3000 $60,000
2,000.00 1 $2,000
5,000.00 1 $5,000
SUBTOTAL $357,800
$28,900
$107,250
SUBTOTAL $493,350
$39,468
$10,000
$74,003
$49,335
SUBTOTAL $172,806
$666,156
$25.00 208 $5,200
$0.12 10000 $1,200
Materials and Supplies Is $2,000.00 1 $2,000
Sample Analysis Is $1,000.00 1 $1,000
O&M Contingencies 25.00%
Total Annual O&M Costs
Periodic Costs (EPA)
SUBTOTAL $9,400
$2,350
$11,750
Five-Year Review Is $10,000.00 1 $10,000
Contingencies 25.00%
Total EPA Five-Year Costs
$2,500
$12,500
Notes:
1. System users' O&M identified for information only; not considered part of present worth of remedial action.
Upper Tenmile Creek ROD.wpd
12-15
-------
Section 12
Selected Remedy
Table 12-7
30-Year Present Value Analysis for Rimini
Community Wastewater System Contingency Remedy
Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Totals
Present Value
Capital
Costs
$666,156
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$666,156
$666,156
System
User O&M
Costs 1
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$11,750
$352,500
$145,802
EPA
Post-
Construction
Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
-
$0
Five Year
Review
Costs
(EPA)
$0
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$0
$0
$0
$0
$12,500
$75,000
$26,971
EPA
Total Annual
Expenditures
$666,156
$12,500
$12,500
$12,500
$12,500
$12,500
$12,800
$741,156
$693,129
Discount
Factor (7%)
1.0000
0.9346
0.8734
0.8163
0.7629
0.7130
0.6663
0.6227
0.5820
0.5439
0.5083
0.4751
0.4440
0.4150
0.3878
0.3624
0.3387
0.3166
0.2959
0.2765
0.2584
0.2415
0.2257
0.2109
0.1971
0.1842
0.1722
0.1609
0.1504
0.1406
0.1314
Present
Value
$666,156
$8,913
$6,354
$4,530
$3,230
$2,303
$1 ,643
$693,129
$693,129
Notes:
1. System users' O&M identified for information only: not considered part of present worth of remedial action.
Upper Tenmile Creek ROD.wpd
12-16
-------
(construction of the remedy components) and 100 percent of O&M. The specific assurances
are provided in a Superfund state contract to be executed by EPA and the state prior to
commencement of remedial action. At this site, because of the numerous complexities and
contingencies in implementing the selected remedy, the agencies will use a seguence of
Superfund state contracts. Each contract shall serve as the authorization to proceed with
construction of the remedial elements covered in that particular agreement.
The NCP also defines the conditions under which remedial action is determined to be
complete and O&M begins. In general, for Fund-financed remedial actions, the NCP specifies
that O&M activities begin after the remedy has achieved the site remediation goals and has
been determined to be operational and functional (with the exception of groundwater or
surface water restoration actions) , usually one year after completion of construction. See
NCP, 40 CRF §§ 300.435(f) (2) , 300.510(c), and 300.515(g). Treatment systems for
groundwater or surface water restoration can be operated for up to 10 years after
determined to be operational and functional before remedial action is complete and O&M
begins. The state's O&M obligation, which will be defined in detail in the Superfund state
contract, is triggered after the remedy has been completed.
The O&M activities for each remedial element are described below.
Waste Rock and Tailings
The selected remedy includes removal of waste rock/ tailings, disposal of the removed
material at the Luttrell repository, placement of fill material, construction and removal/
reduction of access roads, and revegetation of the disturbed areas. An expected five to 10
mine sites will be addressed each year, so it will take approximately 10 years to clean up
all of the category C, D, and E sites reguiring waste rock/ tailings removal. O&M for
revegetated areas will reguire observation of vegetative success, occasional reseeding as
necessary, weed control, and maintenance of drainage/ runoff control features.
Luttrell Repository
The Luttrell repository consists of a lined repository for mine wastes and a leachate
collection and treatment system. Wastes from the Upper Tenmile Creek Mining Area and Basin
Creek Mining Area sites and other nearby sites will be placed in the repository over a
period of approximately 10 years. Five or six cells will be constructed at the repository,
all served by a single leachate collection and treatment system. As specific repository
cells are brought to final grade, final cover and vegetation will be placed on the top of
each cell. O&M for the repository will consist of maintenance of the vegetative cover and
runoff control features and O&M of the leachate collection and treatment system. The O&M
phase of the action for the Luttrell repository will not commence until after completion
of all remedial actions (except treatment of surface water and groundwater) for the Upper
Tenmile Creek Mining Area and Basin Mining Area NPL sites, including closure of the
repository into a final naturally-draining configuration. Temporary, interim, or partial
closures of the repository will not be deemed to trigger O&M obligations on
the part of the state.
The state may determine that it would be beneficial to leave a small area of the Luttrell
repository available (with a temporary cover) for future disposal of limited guantities of
site wastes, such as water treatment system sludge or contaminated soils from currently
undeveloped areas or inaccessible locations. A decision to leave a small repository cell
open for long-term state use shall not impact the closure of the Luttrell repository and
transition to repository O&M defined above.
Acid Mine Drainage
The AMD remedy consists of a four-phase approach to first reduce the guantity of AMD and
then treat the residual discharge if necessary. Remedy components are expected to include
surface water inflow controls, adit discharge flow reduction controls (may include
grouting, plugging, or flow segregation features), and AMD treatment facilities. EPA
expects the initial effort to evaluate and implement flow reduction/source control actions
and conduct pilot treatability studies to take approximately six years. Subseguent design
and construction of AMD treatment facilities would be done over the next four years, so
-------
the implementation of the AMD remedy is anticipated to take about 10 years. O&M activities
will include vegetation/erosion control inspections and maintenance for surface water
inflow controls (conducted concurrently with waste rock/ tailings O&M), maintenance of
shaft caps and plugs, inspection and O&M of flow reduction facilities, and O&M of AMD
treatment facilities, including sludge disposal or substrate removal/disposal. Long-term
operational sampling and analysis would be reguired for operation of the AMD treatment
facilities. The NCP provides for a 10-year operational prove-out period for treatment
facilities designed to restore groundwater or surface water. At the end of the 10-year
prove-out, O&M would commence.
Groundwater
The groundwater remedy will be accomplished through the source control measures
implemented for the other media and the establishment of institutional controls to prevent
consumption of contaminated groundwater. The ROD assumes that institutional controls will
consist of a controlled groundwater area under State of Montana laws. Groundwater O&M will
include maintenance of the institutional controls, in coordination with the county, and a
limited amount of groundwater sampling to confirm the continuing protectiveness of the
remedy. Specific reguirements of the controlled groundwater area will not be known until
the area is established.
Surface Water
Surface water remedy components include improvements to the existing Chessman Reservoir
and Red Mountain flume in order to increase water storage capacity and/or other approaches
to augmentstream flow in Tenmile Creek to improve water guality during seasonal dry
periods. Routine operation of the reservoir facilities includes adjusting reservoir and
flume flow and stage parameters and routine inspection, maintenance, and reporting of the
dam facilities. O&M reguirements and responsibilities for the reservoir and flume
improvements would be defined in consultation with the current operator of the facilities.
The remedy also reguires long-term monitoring of surface water guality throughout the
watershed. This long-term monitoring program will be conducted by EPA, DEQ, DFWP, and
USGS. It will include monitoring for chemical and biological parameters to demonstrate
water guality improvements and compliance of the remedy with performance standards.
Sediment
No action will be taken for sediments under the selected remedy. Sediment guality will be
monitored over time as other source control actions are completed. Sediment removal would
occur only if sediments are determined to cause continuing unacceptable loading of
contaminants to Tenmile Creek. Currently, the only remedy activity for sediments is
monitoring. Monitoring of sediments will be part of the overall long-term monitoring
program for surface water.
Contaminated Yard Soils
Soils in yards at residences or occasional-use recreational cabins with concentrations of
arsenic or lead exceeding the target action levels will be removed and placed in the
Luttrell repository. Some contaminated material will be left in place because it is
inaccessible (such as under sidewalks or driveways). The yards will be backfilled with
clean soils and revegetated. Institutional controls will be necessary to ensure that
excavation during future development is done in a manner that does not release
contaminants left in place. Maintenance of the reclaimed yards will be the responsibility
of the property owners. Institutional controls are assumed to include establishment and
utilization of a building permit process that informs and reguires property owners to
dispose of any excavated mine wastes/tailings or contaminated soils at the Luttrell
repository or another appropriate disposal facility.
A contingency remedy component includes the design and construction of a small community
wastewater system, if necessary, to replace individual septic systems that are damaged or
removed during the excavation of contaminated yard soils in Rimini. The community
wastewater system would reguire O&M for the pumps, sand filtration system, sewer lines,
and leach field. O&M would be borne by the system users.
-------
Contaminated Roadway Materials
The remedy includes excavating, transporting, and disposing of all accessible contaminated
materials in Rimini Road within the community of Rimini. The excavated portions of the
road would be backfilled with clean fill and gravel road subbase and surface materials.
Inaccessible materials near building foundations, utility poles, and other structures will
be left undisturbed. EPA anticipates that no long-term maintenance relative to the
contaminated materials will be necessary because nearly all of the contaminated material
will be removed.
Pi mini Water System
The remedy includes construction of a new public water system for the community of Rimini.
Residents currently having wells impacted by contaminated groundwater have been provided
individual POU treatment systems. Operation of the POU systems reguires routine monitoring
and changeout of filter cartridges. O&M of the community water system will reguire routine
sampling and servicing of system eguipment. Treatment will be limited to chlorination
only, so no treatment sludge will be produced. O&M would be the responsibility of the
system users.
12.5 Expected Outcome of the Selected Remedy
For solid media, the remedial action for the site will achieve acceptable exposure risks
through a combination of contaminant source removal and institutional measures to control
access to and potential remobilization of waste materials. The remedy for the site is
expected to remove all major sources of waste rock/tailings contamination from the
abandoned and inactive mine sites (category C, D, and E) located in the upper Tenmile
Creek watershed, contaminated soils at residences and occasional- use recreational cabins,
and contaminated roadway materials in the community of Rimini. Risks to human health from
direct contact and incidental ingestion of contaminated soils and sediments will be
eliminated or reduced to acceptable levels. Exposure to contaminated media at low priority
mine sites (category A and B) will be controlled by limited access to these sites and, if
necessary, institutional controls to address potential future development at the sites.
Upper Tenmile Creek watershed surface waters are used currently as the primary water
supply for the City of Helena. In addition, a number of residences in Rimini and
recreational cabins have piped connections to untreated surface water that may be used for
drinking water. Under both RME and CTE exposure assumptions, current and future potential
exposures exceed risk-based acceptable levels. In addition, state human health and aguatic
life standards for surface water for a number of parameters are exceeded at numerous
stream locations throughout the site. The remedial action will reduce exposure risks over
time and protect Helena's water supply system primarily by removing major contaminant
source loadings. All mine sites in direct contact with surface water (including those with
AMD) will be remediated by source control methods, which should minimize contaminant
loading from the mine sites to Tenmile Creek and its tributaries and to the watershed's
aguatic ecosystem. With source removals completed and AMD addressed through the four-
phase approach, natural attenuation over time is expected to allow Tenmile Creek and
tributary surface waters to attain state water guality standards. The remedial action will
also provide an alternate source of drinking water for any residents in Rimini that
currently use untreated surface water.
Constructing reservoir improvements or otherwise providing for the ability to augment
stream flow in Tenmile Creek during low flow periods will improve water guality in the
stream. Anticipated improvements to water guality are depicted in Figures 12-2 through
12-6. These figures provide the results of computerized modeling of contaminant load
reduction and flow augmentation improvements specified in the selected remedy. They were
developed during the evaluation of various alternative remediation strategies in the
technical memorandum modeling fate and transport of COCs in Tenmile Creek (COM 2001f). The
figures show that concentrations of all COCs in Tenmile Creek, particularly in the Rimini
area, should be substantially reduced by the selected remedy. Water guality standards in
Tenmile Creek for arsenic, cadmium, lead, and zinc may not be attained initially, but
-------
Figure 12-2
Arsenic in Tenmile Creek
Measured vs. Modeled Preferred Alternative
45
Note: chronic aquatic life standard = 150 ug/L
acute aquatic life standard = 340 ug/L
• human health
standard
-*—- measured tot, 2000
nli— modeled preferred
alternative
+ mabistem locations
2000
%
S
4000 Js 6000
is *
Q£
8QOOffl 10000 12000 14000
H Distance downstream (meters)
16QQQ
1SOOO
20000
Fig 12-2 through 12-6 WASP.xls, 'As chart'
-------
Figure 12-3
Cadmium in Tenmile Creek
Measured vs. Modeled Preferred Alternative
- - - human hesHh standard
chronic standard (2000)
acute standard [2000)
chronic standard (2001)
acute standard {2001)
measured tot, 2000
modeled preferred
alternative
matn&fcim
18000
20000
.c Distance downstream (meters)
Fig 12-2 through 12-6 WASP.xls, 'Cd chart'
-------
Figure 12-4
Cadmium in Tenmile Creek
Measured vs. Modeled Preferred Alternative
14,000
12,000
10000
Illl III,
s
,3
^ SQOQ
1
c
o
»
e
o
V
6,000
4.000
2,000
0.000
Note; human health standard = 1,300 ug/L
chronic standard
-—acute standard
» measured tot, 2000
-*—mode ed preferred alternative
•4* mainstem locations
-c Olsiancs downMraam
49
C
1BOOO
20000
Fig 12-2 through 12-6 WASP.xls, 'Cu chart'
-------
Figure 12-5
Cadmium in Tenmile Creek
Measured vs. Modeled Preferred Alternative
20
18
16
14
12
e
a
=3
c
o
u
a
(L
™ " human health standard
""•"""" ""chronic standard
- — ~~ tjcute standard
— *— measured tot, 2000
— A — modeled preferred
sltemitiw
T rHainstem locations
2000
4000 ^ 6000
£>
BQOQ_ 10000 12000 14000
Dlctance downttrvant (meters)
ra
c
ra
16000
18000
20000
Fig 12-2 through 12-6 WASP.xls, 'Pb chart'
-------
Figure 12-6
Cadmium in Tenmile Creek
Measured vs. Modeled Preferred Alternative
1,000
500
Note: human health standard = 2,100 u
•acute and chronic standard
• measured tot, 2000
*-*— mode et! pnefenrecf alternative
0
16000
tsooo
20000
£ DJaUnce downstream {nwters)
Fig 12-2 through 12-6 WASP.xls, 'Zn chart'
-------
concentrations of these parameters are expected to be sufficiently reduced to allow a
distribution of all age classes of fish throughout reaches of Tenmile Creek previously
determined to be lethal to older fish (Rimini area) and fish fry (Rimini to Moose Creek
Campground). As fish experience a lower level of stress following cleanup and fish are
able to move through these stream reaches, fish populations are expected to recover. Water
guality in the watershed will be monitored over time and additional remedial action, such
as sediment removal, may be implemented if necessary.
By accomplishing significant reductions in metals loading in Tenmile Creek and key
tributaries through source controls, the implementation of the selected remedy will enable
the State of Montana to achieve at least a portion of its total maximum daily load (TMDL)
allocation plan for the Upper Tenmile Creek watershed. The TMDL must address metals,
habitat alteration, and turbidity in the stream reach above Rimini and metals and flow
alteration in the reach from Rimini to the Helena water treatment plant. In addition to
addressing metals load reduction, the selected remedy secondarily will provide for
augmentation of stream flows in currently dewatered reaches and will help reduce sediment
loads from unpaved roads.
Wells are currently the primary source of drinking water at most residences and
recreational cabins at the site. Near the community of Rimini and at a number of remote
mine site locations, the groundwater has been contaminated by historical mining activity.
The remedial action will protect Rimini-area residents by implementing a community water
system to replace contaminated wells and by implementing institutional controls to prevent
the use of contaminated groundwater for drinking water purposes. The remedy will also
implement source controls, such as mine waste removals, AMD flow reduction, and
potentially AMD treatment, to reduce contaminant loading to groundwater.
12.6 Performance Standards
Arsenic is the primary COG with respect to carcinogenic and noncancer health effects from
solid media, surface water, sediment, and groundwater. The risk assessment indicated that
incidental ingestion of solid media and ingestion of surface water and groundwater for
drinking water consumption pose threats to current and potential future residents and
workers. In addition, incidental ingestion of solid media and sediment poses a threat to
recreationists. Arsenic and lead are the major COCs for sediment and surface soils. The
major COCs presenting a potential for adverse ecological effects relative to surface water
are cadmium, copper, lead, and zinc.
The list of applicable or relevant and appropriate reguirements (ARARs) with which the
selected remedy must comply is contained in Appendix A. A number of key ARARs are
discussed in the following paragraphs. In addition, risk-based cleanup levels have been
developed to address potential risks from exposure to solid media (waste rock/tailings and
soils) , since there are no contaminant-specific ARARs for solid media. The solid media
cleanup levels are also discussed below.
Solid Media.
Cleanup levels and excavation levels are presented in Table 12-8 for select solid media at
mine sites and residential and recreational yards. Yards with contaminant concentrations
higher than the excavation levels shown in the table and category C, D, and E mine sites
are proposed for remediation. The excavation levels are set at concentrations 20 percent
lower than the acceptable risk levels (cleanup levels) to account for the variability in
contaminant concentrations in the soil and ensure that the final remedial (i.e., cleanup)
levels are met. For residential yards, the excavation level for arsenic is 96 mg/kg and
for lead is 800 mg/kg. For yards at part-year recreational cabins, the excavation level
for arsenic is 1,150 mg/kg. No excavation level for recreational exposure to lead is
proposed because lead is of concern primarily for children under 6 years of age with
continual exposure in a residential setting.
-------
Table 12-8
Soil Cleanup Levels and Initial Excavation Criteria
Contaminant
Cleanup Levels
(mg/kg)
Excavation Criteria
(mg/kg)
Residential
Arsenic
Lead
120
1,000
96
800
Recreational
Arsenic
1,440
1,150
The cleanup levels for arsenic identified in Table 12-8 are equivalent to an estimated
excess cancer risk level of approximately 1.0x10-5 under the CTE exposure scenario (refer
to Section 7, Table 7-17) . Under the RME exposure scenario, the cleanup level for arsenic
would equate to an estimated excess cancer risk of approximately 2x10-4. Backqround
arsenic concentrations at the site are rouqhly equivalent to a risk level of 1x10-4 ,
assuminq RME exposure. For lead, the cleanup level is equivalent to a hazard quotient
approximately equal to one under the CTE exposure scenario. EPA believes the CTE exposure
scenario better predicts potential exposure at the site than the RME scenario and has
therefore used CTE to quide its risk manaqement decision for arsenic and lead in soils.
The waste rock/tailinqs removal at cateqory C, D, and E mine sites and disposal of removed
materials at the Luttrell repository must comply with a number of action-specific ARARs
reqardinq solid waste manaqement and reclamation of mininq-disturbed areas. Those ARARs
require desiqn and implementation of appropriate drainaqe, topoqraphy, veqetation, and
other features to minimize sedimentation and erosion and provide for successful lonq-term
reclamation of the disturbed areas. The specific desiqn requirements for reclamation will
be identified durinq remedial desiqn.
Groundwater
Cleanup levels for qroundwater, set at human health standards established by the EPA and
the State of Montana, are presented in Table 12- 9. Ambient qroundwater standards apply
throuqhout the entire site. The time frame required to attain ambient qroundwater
standards is uncertain. EPA will monitor qroundwater over several five- year review
cycles, conduct additional source control actions as appropriate, and then make a
determination, in consultation with DEQ, whether waiver of the state ambient qroundwater
standards in certain locations should be considered, in accordance with Section 12.7,
Remedy Continqencies.
-------
Table 12-9
Cleanup Levels for Key Chemicals of Concern
in Surface Water and Groundwater
Contaminant
Aluminum
(Ug/L)
Arsenic
(Ug/L)
Cadmium
(Ug/L)
Copper
(Ug/L)
Lead
(ug/L)
Mercury
(Ug/L)
Zinc
(Ug/L)
Surface Water (1)
Human Health
Standard (2)
Acute Aquatic Life
Standard (2,3)
Chronic Aquatic
Life Standard (2,4)
NA
750
87
10 (5)
340
150
5
0.52 (6)
0.10 (6)
1,300
3.8 (6)
2.8 (6)
15
14 (6)
0.54 (6)
0.05
1.7
0.91
2,100
37 (6)
37 (6)
Groundwater
Human Health
Standard (2)
na
10 (5)
5
1,300
15
2
2,100
Notes:
(1) Surface water cleanup level is shown in bold and is lowest of human health and aquatic standards.
(2) Montana Numeric Water Quality Standards (Circular WQB- 7), Montana Department of Environmental
Quality, January 2002.
(3) No sample concentrations shall exceed the acute aquatic life standard.
(4) No four-day or lonqer period averaqe concentration shall exceed the chronic aquatic life standard.
(5) The standard shown is the federal MCL, published on October 31, 2001.
(6) The aquatic life standards for cadmium, copper, lead, and zinc are based on hardness of the water,
the values shown assume hardness of 25 mq/L.
Surface Water
Cleanup levels for surface water are set at the lower of either the human health or
aquatic standards presented in Table 12-9. Surface waters within the site upstream of the
Helena water supply intake on Tenmile Creek are classified as "A-l" streams by the State
of Montana. Waters downstream of the intake are classified "B-l" streams. State ambient
surface water quality standards (Circular WQB- 7) apply at all locations in the site. EPA
will monitor surface water quality over time. If, after a number of five- year review
cycles, EPA, in consultation with DEQ, determines that it is not possible to attain
surface water standards for certain parameters (for example, cadmium or zinc) , then EPA
will at that time consider waivinq pertinent surface water ARARs in accordance with
Section 12.7, Remedy Continqencies.
12.7 Remedy Contingencies
Successful implementation of several components of the selected remedy will require
commitments and actions by other parties, such as the formation of a Rimini community
water and sewer district to take ownership of, operate, and maintain the community water
and sewer systems constructed by EPA, the acquisition of water riqhts to facilitate flow
auqmentation in Tenmile Creek, and the establishment of institutional controls (by Lewis &
Clark County and DNRC) to prevent the consumption of contaminated qroundwater. In this
section, EPA describes continqent remedial actions that will be taken by EPA if inaction
by other parties prevents the implementation of an element of the selected remedy or if
actions by other parties are inconsistent with the requirements of the selected remedy.
Rimini Community Water System
Under the selected remedy, EPA will construct a community water system to provide a source
of potable water for those residences in Rimini whose well water currently is impacted by
mininq-related contaminants. EPA will construct the water system only if the community or
potential users of the system aqree to take ownership of the facilities and provide for
onqoinq O&M of the system. The community has bequn the process of forminq a local water
-------
and sewer district for that purpose, which, under Montana law, requires a vote of the
property owners in the affected area. If the formation of a district (or some other legal
entity to own and maintain the system) is not successful, then EPA will not construct the
community system, and the remedy will instead rely on individual POU treatment systems for
all residences in Rimini with well water exhibiting contaminant concentrations greater
than human health standards.
Pi mini Community Wastewater System
The selected remedy includes a contingency for EPA to construct a small community
wastewater system to replace individual septic systems removed during the excavation of
contaminated yard soils. The wasterwater system contingency is necessary because many of
the septic systems in Rimini cannot be replaced in their existing locations because of
current design standards and code restrictions for septic/drainfield systems. If the
community is unable to form a local water and sewer district or another legal entity to
own and operate the community wastewater system, then EPA will not be able to conduct
contaminated soil removal in yards where there is a possibility of damaging the owner's
existing septic systems. EPA will make attempts to locate individual systems and avoid
excavating in those areas. In the vicinity of existing individual septic systems, EPA will
implement Alternative RY2 (cap with 18 inches of soil cover and vegetation). The cover
soil will be graded as necessary to create appropriate drainage and grade continuity with
surrounding features.
Chessman Reservoir/Red Mountain Flume Upgrades and Flow Augmentation
EPA's selected remedy for surface water provides for augmentation of stream flow in
Tenmile Creek within and below Rimini by constructing an upgrade of Chessman Reservoir and
the Red Mountain flume. The additional stored water would be available to the City of
Helena to offset water allowed to bypass the city's Tenmile Creek intake structure in
Rimini during the late summer and early fall low-flow periods. Although this component of
the remedy has been supported by all commenters, there are a number of water rights and
water system operational issues that must be resolved before it can be constructed. EPA
will not construct the reservoir and flume improvements until water rights or leases (or
other appropriate mechanisms to ensure agency access to water for flow augmentation) have
been obtained and binding agreements have been reached among EPA, state agencies, and the
City of Helena outlining how the reservoirs and watershed streams would be managed to meet
the city's water supply system demands, while also attaining desired flow augmentation
goals. During discussions regarding water rights and water system operations, other
appropriate and effective alternative methods of augmenting Tenmile Creek flows in and
below Rimini, such as constructing a new water system diversion structure lower in the
watershed, may be identified and evaluated. If EPA, in consultation with DEQ, determines
that an alternate flow augmentation approach will cost effectively provide protectiveness
similar to that provided by the Chessman/Red Mountain flume upgrade and will be more
easily implemented, then EPA may select the alternative approach as a contingent component
of the surface water remedy.
Groundwater Remedy
The selected remedy for contaminated groundwater includes the establishment of a
controlled groundwater area to ensure that new water wells do not provide contaminated
groundwater for drinking water purposes. Controlled groundwater areas are established by
DNRC in response to applications by local health departments or water and sewer districts.
If the state and local agencies do not establish a controlled groundwater area, then EPA
will develop and distribute maps of the existing extent of groundwater contamination and
will work with Lewis and Clark County planning officials to provide appropriate notice
with respect to properties within the impacted areas. In this manner, current and
prospective property owners will be notified of the need to treat groundwater at certain
properties if the water is to be used for drinking water purposes.
Compliance With Water Quality ARARs
A primary goal of the remedial action is to fully attain water quality standards. If,
after full implementation of the remedial action and several five- year review cycles, it
has not been possible to attain the water quality standards in specific areas, EPA will,
-------
in consultation with DEQ, evaluate whether a waiver of the water quality standards is
necessary to allow exceedance of specific standards in particular reaches of stream or
specific areas of groundwater based on the Fund-balancing waiver. Since this is a Fund-
financed remedy, an ARAR may be waived if the additional expense of further treatment of
the particular discharge would not provide an appropriate balance between the need for
protection at this site and the availability of the Fund to respond to other sites, taking
into account the relative immediacy of the threats. See CERCIA § 121(d)(4)(F), 40 CFR
300.430(f) (1) (ii) (C) (6), Preamble to the NCP, 55 Fed. Reg. 8749-8950 (March 8,1990), and
Office of Solid Waste and Emergency Response (OSWER) Publication No. 9234 2-13/FS (January
1, 1991) .
-------
Section 13
Statutory Determinations
Under CERCLA Section 121, EPA must select a remedy that is protective of human health and
the environment, complies with ARARs, is cost effective, and utilizes permanent solutions
and alternative treatment technologies or resource recovery technologies to the maximum
extent practicable. In addition, CERCLA includes a preference for remedies that include
treatment that permanently and significantly reduces the volume, toxicity, or mobility of
hazardous wastes as a principal element.
13.1 Protection of Human Health and the Environment
The selected remedy will protect human health and the environment through actions designed
to address all identified sources of contamination at the site, including waste rock,
tailings and contaminated soil; contaminated residential and recreational yards; AMD; and
contaminated roadways. The remediated areas will be monitored and maintained through a
comprehensive program using institutional controls, monitoring, and maintenance.
Soils and Solid Media
The selected remedy will protect human health and the environment through the prevention
of direct contact with contaminants at the site. It will effectively isolate the most
significant waste piles (wastes at category C, D, and E sites) , contaminated yard soils,
and contaminated roadway materials by placing them in a lined onsite repository with
leachate control and monitoring. The selected remedy uses vegetative covers for excavated
areas to control erosion. Protectiveness goals for residential and recreational yards will
be met with implementation of the selected remedy. All accessible yard soils with
contaminant concentrations above EPA's health-based excavation criteria will be removed.
Institutional controls will be reguired if any waste is inaccessible and must be left in
place (for example, under residential structures).
Surface Water and Acid Mine Drainage
The selected remedy will protect human health and the environment from exposures to
contaminated surface water through a combination of remedial actions. These actions
include implementing a four-phased approach to reduce metals loading to surface water from
AMD. The remedy includes flow reduction actions, removing solid media source areas to
reduce surface water loading from leaching and erosion, and augmenting Tenmile Creek flows
during low flow periods in order to improve water guality.
Stream Sediments
The selected remedy will not directly remediate sediments; however, source control
actions, including removal of near-stream waste rock and tailings and remediation of AMD
will result in significant improvements to stream sediment guality.
Contaminated stream sediments in the Rimini area that may contribute to degradation of
surface water will be monitored over time and potentially removed, if determined to be a
significant source of metals loading to the stream.
Groundwater
The selected remedy will not directly remediate the groundwater underlying the community
of Rimini or in other areas. Groundwater users in the Rimini area will be protected
through the construction of a reliable deep-well groundwater supply for the community and
institutional controls, such as establishment of a controlled groundwater area, if
necessary. The implementation of a controlled groundwater area will ensure that future
development of residential and recreational property will reguire monitoring of any
installed wells, the use of treatment systems, or connection to the community system as
necessary or possible.
-------
13.2 Compliance with ARARs
EPA's final determination of ARARs is set forth in Appendix A of this ROD.
Contaminant-Specific ARARs
The selected remedy is expected over a reasonable time frame to attain the surface water
standards for Tenmille Creek as designated under Montana law. Administrative Rules of
Montana 17.30.622 and 17.30.623 specify the standards for the "A-l" and "B-l"
classifications applicable to Tenmile Creek and its tributaries and, for each contaminant,
requires attainment of the more restrictive of the aquatic life standard or the human
health standard set forth in Montana DEQ Circular WQB-7. The four-phase approach for
addressing AMD will reduce metal loading to surface waters first through flow reduction
and source isolation techniques and then through passive or active water treatment.
Physical/chemical treatment of AMD in the Rimini area will be very effective at removing
contaminants; the treatment facility will remove approximately 99 percent of the
contaminant load and the treatment plant discharge will meet all surface water quality
standards. Passive treatment systems constructed at remote AMD sites will attain cleanup
standards at points of compliance to be defined by EPA during remedial design.
Although there is no basis for nor need to waive surface water ARARs at this time, there
is some uncertainty regarding how long it will take or whether it will be possible to
attain surface water ARARs for arsenic, cadmium, lead, and zinc throughout the Tenmille
Creek watershed because there are additional nonpoint source contaminant loads (for
example, from contaminated groundwater) that will not be addressed directly by the
selected remedy. However, as noted in Figures 12-2 through 12-6, the remedy will achieve
significant reductions in the concentrations of these parameters and should meet the
remedial action objectives of achieving acceptable exposure risks for residents,
recreational visitors, and terrestrial and aquatic species by attaining water quality
standards.
A determination will be made following implementation of the remedy whether the state
surface water quality standards can be met throughout the site in a reasonable time frame.
In consultation with DEQ, EPA will establish a long-term program for monitoring surface
water quality at key locations within the watershed. At each five-year review period, EPA,
in consultation with DEQ, will evaluate improvements in surface water quality and will
make a determination whether additional source control measures are necessary or warranted
to attain the surface water ARARs. If, after a number of five-year review cycles, EPA, in
consultation with DEQ, determines that it is not possible to attain surface water ARARs
for certain parameters (for example, cadmium or zinc) , then EPA will at that time consider
waiving pertinent surface water ARARs in accordance with Section 12.7, Remedy
Contingencies.
For groundwater, the contaminant-specific ARARs for this remedial action include the MCLs
and non-zero maximum contaminant level goals, established under the federal Safe Drinking
Water Act, and the human health standards specified in Montana DEQ Circular WQB-7. The
selected remedy will not remediate directly the groundwater underlying the community of
Rimini or in other contaminant source areas. The selected remedy, including removal of
waste rock/tailings source areas and a four phase program to reduce loading from AMD, is
expected to result in significant improvements in overall groundwater quality. However,
the time frame required to attain ambient groundwater standards is uncertain. EPA will
monitor groundwater standards through several five-year review cycles, conduct additional
source control actions as appropriate, and then, in consultation with DEQ, make a
determination whether waiver of the state ambient groundwater standards should be
considered, in accordance with Section 12.7, Remedy Contingencies.
Location-Specific ARARs
Location-specific ARARs establish requirements or limitations based on the physical or
geographic setting of the site or the existence of protected resources in the operable
unit. The selected remedy will attain all location-specific ARARs and no waivers are
-------
necessary.
Action-Sped fie ARARs
Action-specific ARARs generally provide guidelines for the manner in which specific
activities must be implemented. Compliance with action-specific reguirements will be
ensured through appropriate design and implementation of the selected remedy.
The selected remedy is to be designed and implemented in accordance with dust suppression
and air guality regulation, certain reclamation reguirements which have been determined to
be relevant and appropriate to this action, and other action- specific ARARs identified in
Appendix A.
13.3 Cost Effectiveness
Section 300.430(f) (ii) (D) of the NCP reguires evaluation of cost effectiveness. Overall
effectiveness, which is determined by evaluating long-term effectiveness and permanence;
reduction of toxicity, mobility, and volume through treatment; and short-term
effectiveness, is then compared to cost to ensure that the remedy is cost effective. Based
on these comparisons, EPA has determined that the selected remedy is cost effective in
mitigating the principal risks posed by mine wastes, contaminated soils and AMD.
The relevant considerations for cost effectiveness of the selected remedy are presented in
Tables 13-1 and 13-2. The estimated cost of the selected remedy, and the other
alternatives, are presented.
Sitewide Alternatives
Alternative 1 (No Action) is not considered to be cost effective. While Alternatives 2, 3,
and 4 are considered cost effective, Alternative 5 provides a proportionally greater
return on investment. The additional cost is reasonably related to the additional benefits
in long-term effectiveness and permanence and reduction of toxicity and mobility of the
contaminants through the waste excavation/disposal and treatment to be used. The
additional costs of Alternatives 6 and 7 do not provide proportionally greater or more
cost- effective risk reduction. The selected remedy meets the criteria and provides for
overall effectiveness in proportion to its cost.
Rimini Water Supply Alternatives
All action alternatives for the Rimini community water system are considered cost-
effective, although there is considerable uncertainty about the long-term effectiveness of
Alternative B (POU treatment systems). Alternative E (community system with treated Rimini
groundwater as source) provides the greatest proportional return on investment, providing
significant increased effectiveness at small additional costs. However, Alternative E has
considerably higher O&M costs, which must be borne by residents of the community of
Rimini, that makes its overall implementability uncertain. Although the selected remedy
(Alternative D - community system with deep well groundwater as source) is cost-
effective, it is not the most cost- effective alternative.
13.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies (or Resource Recovery Technologies) to the Maximum
Extent Possible
EPA has determined that the selected remedy represents the maximum extent to which
permanent solutions can be used in a cost effective manner at the site. The selected
remedy removes waste from contaminated mine sites, yards at residences and occasional-use
recreational cabins, and roadways and transports the waste to an existing repository. The
remedy implements a four-phase approach to reducing metal loading to surface water from
AMD and uses alternative and innovative technologies for flow reduction (e.g., grouting
and flow segregation) and water treatment, including passive, biological systems. The
remedy also implements an innovative remedial strategy that could improve the existing
City of Helena reservoir system so that Tenmile Creek flows can be augmented during
-------
Table 13-1
Cost-Effectiveness Evaluation for Sitewide Alternatives
Alternative
1
2
3
4
5, as modified
(Selected
Remedy)
6
7
Present Worth
Cost
$0.00
$15,158,000
$15,648,000
$18,195,000
$22,204,000
$24,657,000
$35,31 1 ,000
Cost
Increment
from Prior
Alternative
—
$15,158,000
$490,000
$2,547,000
$4,009,000
$2,453,000
$10,654,000
Long-term Effectiveness and
Permanence
No reduction in long-term risks to human
health and the environment.
Long-term risks reduced to acceptable
levels for category D and E sites,
residential yards, and groundwater. Long-
term risks above acceptable levels may
continue to exist for category C sites,
surface water, roadways and stream
sediments.
Same as Alternative 2, except long-term
risks reduced to acceptable levels at
category C sites and more permanence
for category D sites.
Same as Alternative 3, except risks
reduced to acceptable levels for
roadways. Greater effectiveness for
surface water but long-term risks may still
exceed acceptable levels.
Same as Alternative 4, except risks
reduced to acceptable levels for surface
water and more permanence for category
C sites.
Same as Alternative 5, except risks
reduced to acceptable levels for category
B sites.
Same as Alternative 6, except further risk
reduction for surface water.
Reduction of Toxicity, Mobility, or
Volume Through Treatment
No reduction in toxicity, mobility or
volume of waste.
Moderate reduction in toxicity, mobility
and volume over the long term.
Same as Alternative 2.
Greater reduction in toxicity, mobility, or
volume than Alternative 2 or 3.
Same as Alternative 4.
Same as Alternative 5.
Greater reduction in toxicity, mobility, or
volume than other alternatives.
Short-term Effectiveness
No increase in short-term risk to
community, environment or
workers.
Moderate short-term risk to
environment and workers during
construction. Low short-term risk
to community.
Same as Alternative 2.
Same as Alternative 3.
Same as Alternative 4.
More short-term risk than
Alternative 5 because more sites
addressed.
Same as Alternative 6.
Table 13-1 and 13-2.wpd
-------
Table 13-2
Cost-Effectiveness Evaluation for Rimini Community Water System Alternatives
Alternative
A
E
C
B
D
(Selected
Remedy)
Present Worth
Cost
$0.00
$281,000
$344,000
$400,000
$495,000
Cost
Increment
from Prior
Alternative
-
$281 ,000
$63,000
$56,000
$95,000
Long-term Effectiveness and
Permanence
No reduction in long-term risks to human
health and the environment.
Would provide much more certain long-
term effectiveness than Alternative B. The
ability of the community to financially
support the long-term operation of the
system is uncertain.
Increased effectiveness over Alternative E
because its source water is
uncontaminated and does not need a
water treatment facility.
Long-term effectiveness is uncertain
because it depends on individual residents
conducting routine maintenance on the
treatment systems, such as replacing the
filters. There is no effective mechanism for
EPA to ensure that all POU systems are
maintained properly.
Similar to Alernative C, but greater long-
term effectiveness. Deep wells in a
fractured bedrock system at the mouth of
a major watershed would be more reliable
(could provide adequate water during
various hydrologic conditions, inluding
drought) than the spring source in the
headwaters of Spring Creek.
Reduction of Toxicity, Mobility, or
Volume Through Treatment
No reduction in toxicity, mobility or
volume of contaminants.
Same as Alternatives A and B for the
community water system components.
However, the AMD treatment system
from which source water would be
obtained (sitewide remedy component
AD4/5) would remove contaminants with
treatment and dispose of them in the
secure Luttrell repository.
No reduction in toxicity, mobility, or
volume of contaminants.
Exposure to residents is prevented by
treatment of contaminated groundwater.
However, contaminants removed by
treatment would be returned to the
environment (soils and groundwater)
during treatment system backwash
because all residences use individual
wastewater disposal systems. There is
no net reduction in toxicity, mobility, or
volume of contaminants in the long-term.
Same as Alternative C.
Short-term Effectiveness
No increase in short-term risk
to community, environment or
workers.
Increased, though still not
significant, risk to workers and
residents during construction
because it would require
trenching, pipe laying, and
erection of an elevated tank.
Same as Alternative E.
Minimal increase in short-term
risks.
Same as Alternative C.
Table 13-1 and 13-2.wpd
-------
periods of low flow to achieve water quality requirements. This combination of remedial
options attempts to maximize the use of both permanent solutions and alternative treatment
technoloqies and provides the hiqhest effectiveness at the least cost.
13.5 Preference For Treatment as a Principal Element
Various treatment options for contaminated soils and mine wastes were considered in the FS
process; however, due to the nature and volume of the contaminated soils and mine wastes,
these wastes are not considered to be principal-threat wastes and the treatment options
were determined to be either technically impracticable, not necessary, or not cost-
effective.
For AMD, physical/chemical treatment of the Rimini-area adits and passive bioloqical
treatment of remote adits were found to be the most technically practical and cost
effective methods for achievinq remediation qoals for these sources. These treatment
options are included as the final phase of a four-phase proqram to address AMD. The first
phases of the proqram will evaluate and implement appropriate and innovative AMD source
control and flow reduction actions to minimize the loadinq from AMD sources and the amount
of treatment required. The last phase of the proqram, treatment of AMD with physical/
chemical or passive bioloqical systems, will be implemented if necessary to meet surface
water quality standards. The four-phase proqram of source control, flow reduction, and
treatment meets the statutory preference for treatment as a principal element of the
remedy.
13.6 Five-Year Review Requirements
Since some contaminated soils and mine wastes will remain on site, the selected remedy
requires five-year reviews as provided for under Section 121 of CERCLA and Section
300.430(f)(4)(ii) of the NCP. Each five-year review will include a review of the
qroundwater and surface water monitorinq data and an evaluation as to how well the
selected remedy is achievinq the RAOs and ARARs that it was desiqned to meet.
-------
Section 14
Documentation of Significant Changes
The proposed plan for the site was issued for public comment on October 22, 2001. Based on
comments received on the proposed plan, EPA has made the following change to the proposed
plan preferred alternative in establishing the selected remedy:
Contaminated Roadway Materials
The preferred alternative in the proposed plan called for excavating and replacing with
clean material the top 18 inches of the road for approximately 2,500 feet in Rimini. The
selected remedy in this ROD provides for removing all accessible contaminated materials
from Rimini Road within the community of Rimini. This portion of the road was largely
washed away during a major flood in 1981. When the road was rebuilt after the flood, waste
materials from the Susie mine site were used. In some locations as much as 10 feet of
waste material was placed as subgrade road material. Although the road has generally been
capped with a few inches of clean fill during routine maintenance over the years, RI
sampling confirmed the presence of contaminated waste materials that might be prone to
release into the residential area of Rimini as the road surface wears away. Based on
comments from the state expressing concern over the potential erosion and redistribution
of contaminated materials during severe flooding events in the future, EPA has decided to
remove all contaminated materials that can be accessed without danger to nearby building
foundations or other property features.
Contaminated Yard Soils
The preferred alternative in the proposed plan called for the excavation, removal, and
disposal of the uppermost 18 inches of contaminated yard soils at residences and
occasional-use recreational cabins, followed by backfill with clean soils and
revegetation. This element of the remedy is intended to eliminate current and potential
future human health risks from direct contact with the contaminated soils. The selected
remedy in this ROD includes the removal of all accessible contaminated yard soils rather
than only the top 18 inches. This change was made to address concerns by the State of
Montana over the potential need to rely on institutional controls to guide excavation and
development in the future and to maintain an open repository in perpetuity to accommodate
future removals of contaminated soils from the yards. Removing as much of the contaminated
soil as possible now will minimize the need to handle contaminated soils in the
future and costs associated with future work.
The selected remedy also includes a contingency for constructing a Rimini community
wastewater system, which was not envisioned in the proposed plan. This contingency is
intended to address the possibility that a number of existing individual septic/drain
field systems in Rimini may be irreparably damaged during the removal of contaminated yard
soils. Because current design standards prevent the installation of new or upgraded septic
systems within 100 feet of the 100-year floodplain, many of the current systems may not be
replaceable in their existing locations or within the existing property boundaries. The
contingency for this part of the remedy provides that EPA would construct a small
community wastewater collection and treatment system (intermittent sand filter and
pressure-dosed drainfield) to replace those septic systems removed during the yard
removals. The community system would be owned and operated by the local sewer and water
district.
-------
Section 15
References
Auerlich, R. J. , R. K. Ringer, M. R. Bleavins, and A. Napolitano. 1982. Effects of
Supplemental Dietary Copper on Growth, Reproductive Performance, and Kit Survival of
Standard Dark Mink and the Acute Toxicity of Copper to Mink. Journal of Animal Science.
V55 (2): 37-343.
CCME (Canadian council of Ministers of the Environment), 1991. Interim Canadian
Environmental Quality Criteria for Contaminated Sites. Environmental Quality Guidelines
Division. Water Quality Branch. Environment Canada. Ottawa, Canada.
CDM Federal Programs Corporation (CDM). 1997. Final Baseline Ecological Risk Assessment.
Anaconda Regional Water, Waste, and Soils Operable Unit, Anaconda Smelter NPL Site.
CDM. 2000. Draft Data Summary and Usability Report, Upper Tenmile Creek Mining Area
Superfund Site, Lewis and Clark County, Montana. March.
CDM. 2001a. Ecological Risk Assessment Report for Upper Tenmile Creek Mining Area
Superfund Site, Lewis and Clark County, Montana. March.
CDM. 2001b. Draft Remedial Investigation Report for Upper Tenmile Creek Mining Area
Superfund Site, Lewis and Clark County, Montana. February.
CDM. 2001c. RI/FS Addenda Report, Upper Tenmile Creek Mining Area Site, Lewis and Clark
County, Montana. December.
CDM. 2001d. Final Human Health Risk Assessment Report for Upper Tenmile Creek Mining
Area Superfund Site, Lewis and Clark County, Montana. October.
CDM. 2001e. Draft Feasibility Study Report Upper Tenmile Creek Mining Area Superfund Site,
Lewis and Clark County, Montana. March.
CDM. 2001f. Technical Memorandum Modeling Metals Fate and Transport in Tenmile Creek,
Upper Tenmile Creek Mining Area Site, Lewis and Clark County, Montana. October.
CH2M Hill. 1987a. Assessment of the Toxicity of Copper, Mercury, Selenium, Silver, and
Thallium in the Soil and Plants in the Helena Valley of Montana. Prepared for EPA. May.
CH2M Hill. 1987b. Assessment of the Toxicity of Arsenic, Cadmium, Lead, and Zinc in Soil,
Plants, and Livestock. Prepared for EPA. November.
Department of Environmental Quality (DEQ). 2002. Montana Department of Environmental
Quality. Montana Numeric Water Quality Standards. Circular WQB-7. January 2002.
Department of Fish, Wildlife, and Parks (DFWP). 2001. Personal Communication with Don
Skaar regarding unpublished 1998/99 data.
Efroymson, R. A., M. E. Will, and G. W. Suter II. 1997. Toxicological Benchmarks for
Screening Potential Contaminants of Concern for Effects on Soil and Litter Invertebrates
and Heterotrophic Process: 1997 Revision. Oak Ridge National Laboratory. Oak Ridge, TN.
Efroymson, R. A., M. E. Will, G. W. Suter II, and Wooten. 1997. Toxicological Benchmarks
for Screening Potential Contaminants of Concern for Effects on Terrestrial Plants: 1997
Revision. Oak Ridge National Laboratory. Oak Ridge, TN.
-------
Eisler, R. 1985. Cadmium Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review.
Biological Report 85(1.2). Contaminant Hazard Reviews Report No. 2. Patuxent Wildlife
Research Center. U. S. Fish and Wildlife Service, Laurel, MD.
Eisler, R. 1988. Lead Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review.
Biological Report 85(1.14). Contaminant Hazard Reviews Report No. 14. Patuxent Wildlife
Research Center. U. S. Fish and Wildlife Service, Laurel, MD.
U. S. Environmental Protection Agency (EPA). 1985a. Ambient Water Quality Criteria for
Cadmium - 1984. EPA 440/5-84-032. Office of Water. Regulations and Standards. Washington,
DC.
EPA. 1985b. Ambient Water Quality Criteria for Copper - 1984. EPA 440/5-84-031. Office of
Water. Regulations and Standards. Washington, DC.
EPA. 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies Under
CERCLA. EPA/540/6-89/004. Office of Emergency and Remedial Response. Washington, D. C.
EPA. 1988a. Ambient Water Quality Criteria for Aluminum - 1988. EPA 440/5-86-008. Office
of Water. Regulations and Standards. Washington, DC.
EPA. 1991. Risk Assessment Guidance for Superfund, Volume 1. Human Health Evaluation
Manual. Part B, Development of Risk- Based Preliminary Remediation Goal. Interim. Office
of Emergency and Remedial Response. Washington, D. C. September 29.
EPA. 1992. Framework for Ecological Risk Assessment. EPA/630/R-92-001. Risk Assessment
Forum. Washington, D. C.
EPA. 1999. Clark Fork River Ecological Risk Assessment. EPA Region VIII. December
EPA. 1999a. A Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other
Remedy Selection Decision Documents. July 1999.
Ingersoll, C. C., P. S. Haverland, E. L. Bruson, T. J. Canfield, F. J. Dwyer, C. E. Henke,
N. E. Kemble, D. R. Mount, and R. G. Fox. 1996. Calculation Evaluation of Sediment Effect
Concentrations for the Amphipod Hyallela azteca and the Midge Chironomus riparius. Great
Lakes Res. 23:602-623.
Jones, D. S., G. W. Suter, and R. N. Hull. 1997. Toxicological Benchmarks for Screening
Potential Contaminants of Concern for Effects on Sediment-Associated Biota: 1997 Revision.
Oak Ridge National Laboratory. Oak Ridge, TN.
Kabata-Pendias, A. and H. Pendias. 1992. Trace Elements in Soils and Plants (2nd Edition).
CRC Press, pp. 365.
Larison, J. R., G. E. Likens, J. W. Fitzpatrick, and J. G. Crock. 2000. Cadmium Toxicity
Among Wildlife in the Colorado Mountains. Nature Magazine Vol. 406. July 13.
Persaud, D., R. Jaagumagi, and A. Hayton. 1993. Guidelines for the Protection and
Management of Aquatic Sediment Quality in Ontario. Queen's Printer for Ontario. Ontario,
Canada.
Rice, P. M. and G. J. Ray. 1984. Floral and Faunal Survey and Toxic Metal Contamination
Study of the Grant-Kohrs Ranch National Historic Site. Report prepared by Gordon
Environmental Studies Laboratory, Botany Department, University of Montana, Missoula, MT.
May, 1984.
-------
Suter, G. W. II and C. L. Tsao. 1996. Toxicological Benchmarks for Screening Potential
Contaminants of Concern for Effects on Aquatic Biota: 1996 Revision. Oak Ridge National
Laboratory. Oak Ridge, TN.
-------
Responsiveness Summary
This section of the ROD provides a summary of all comments received on the draft and
final proposed plans and EPA's responses to those comments.
EPA has received comments on a number of documents prepared for the project. Comments on
the draft RI and draft FS reports, which were received from staff from reviewing agencies
and were primarily technical in nature, were addressed in the RI/FS addenda report.
Comments from the general public, as well as staff from other agencies, were received on
the preliminary draft proposed plan( presented to agency representatives and local Rimini
residents in July 2001) and the final proposed plan (released to the general public in
October 2001) are addressed in this responsiveness summary. A brief review of the major
comments and EPA's responses to those comments is provided in this section of the ROD.
Copies of the comments and point-by-point responses are provided in Appendix C.
Overall Support for Proposed Plan
In response to both the preliminary draft proposed plan and the final proposed plan, the
comments expressed overwhelming support for EPA's overall remedy approach. Although a
number of comments identified concerns with, or suggested alternative approaches to,
particular remedy components, all emphasized overall support for the planned cleanup of
mining wastes within the upper Tenmile Creek watershed. One commenter recommended that EPA
place more emphasis on the treatment of acid mine drainage (AMD) because that is the most
significant source of metals loading to Tenmile Creek. The commenter suggested that the
major waste rock/tailings sources have already been addressed by removal actions over the
last five years.
EPA appreciates the overwhelming public support for its cleanup action. EPA agrees that
AMD is a significant loading source. However, EPA has developed a remedy that is intended
to address more than just current metals loading to Tenmile Creek. That remedy must
include elements to address near stream waste rock/tailings piles that may, over time,
erode into Tenmile Creek or its tributaries and increase loading to both sediment and
surface water. In addition, potential risks to human health at easily-accessible mine
sites must also be addressed. EPA believes that its selected remedy has the appropriate
balance for addressing all media and potential exposure routes in a comprehensive and
cost-effective manner.
Water Storage and Tenmile Creek Flow Augmentation
All comments supported the development of additional water storage within the upper
Tenmile Creek watershed, with the stored water to be used to augment stream flow within
Tenmile Creek below the Helena water system diversion structure in Rimini. Several
alternatives considered in the preliminary draft proposed plan included the construction
of a new reservoir at the Travis location along the headwaters of Tenmile Creek, near the
BCM. Based on comments received about potential impacts on wetlands and wildlife from
building a reservoir at the Travis location (refer to "wetlands" discussion below), EPA
researched and identified two alternatives for obtaining additional water storage in the
watershed. One possible alternative was to build a new reservoir on Banner Creek in a
location known as the Banner Creek tailings. This alternative would have entailed
constructing a new dam of approximately 65-foot height and relocating existing roads that
would have been inundated when the reservoir was filled. The other possible alternative
was to enlarge the City of Helena's existing Chessman Reservoir by approximately 500 acre-
feet, which would require raising the current dam and emergency spillway by about 5 feet.
Chessman Reservoir is filled each spring primarily by diverting water from Banner Creek
through the Red Mountain flume. Water diversions into the flume can occur only for a short
time in early spring prior to the first call for irrigation water downstream. To fill an
enlarged Chessman Reservoir in the allowable time frame each year, improvements to the Red
Mountain flume to increase its capacity also would be necessary. Since the discharge from
Chessman Reservoir is used to supply water to the Helena water system, the additional
stored water in Chessman would not be available to augment Tenmile Creek flows directly.
-------
Flow augmentation would be accomplished by having the city release additional water from
Scott Reservoir and allow that water to bypass the Tenmile Creek intake structure in
Rimini.
The City of Helena expressed support for any of the additional water storage/flow
augmentation alternatives. The city indicated a preference for the Travis location because
that alternative would have the least impact on how the city operates its current water
collection system. However, given the concerns over the potential impacts on wetlands, the
city indicated that any of the alternatives would be acceptable. The selected remedy
includes the alternative of increasing the capacity of Chessman Reservoir. In its
comments, the city noted a willingness to manage Scott Reservoir so that additional water
would be released and allowed to remain in Tenmile Creek for flow augmentation during dry
periods.
Potential Impacts on Wetlands and Mitigation of Impacts
In response to the preliminary draft proposed plan, numerous comments expressed concern
over potential adverse impacts of constructing a new reservoir at the Travis location in
the upper Tenmile Creek headwaters. The Travis location, which was historically the site
of a small impoundment presumably to support early mining operations, contains a large
meadow (approximately 40 acres) of high quality wetlands. A new reservoir at this site
would have flooded almost all of the existing wetlands.
In response to the concerns over wetlands at the Travis location, EPA investigated and
developed other possible alternatives additional water storage and flow augmentation. The
selected remedy could increase the capacity of Chessman Reservoir by approximately 500
acre-feet. Doing so would inundate approximately 15 acres of wetlands that are not as high
quality as those at the Travis location. Other wetlands within the site may also be
impacted by EPA's remedial action. Waste rock/tailings removals at near-stream locations,
remediation of mine adit discharges, and other project actions may cause loss of wetlands
or reduce wetlands value. During remedial design, EPA will work with USFWS to evaluate the
loss of wetlands and develop appropriate wetlands mitigation. The loss will be mitigated
by creation of additional wetlands values elsewhere in the watershed. The prime candidate
location for wetlands mitigation will be the Banner Creek tailings, which is an historical
wetlands location that lost value over time because the stream was channelized and the
wetlands dried out. Both the USFS and USFWS have expressed an interest in reworking the
Banner Creek tailings to reestablish the original wetlands conditions.
Potential Impacts on Wildlife from Improved Road Access
Numerous comments expressed concern over potential adverse impacts on wildlife that may
result from improved human access to the remote locations of the site. The comments noted
that implementation of the remedial action will require the construction of new roads or
the improvement of existing roads to allow large construction equipment to access the
historic mine sites for remediation. The comments suggested that removal actions by both
EPA and USFS over the past three years have provided evidence of the potential for adverse
impacts from improved access. The comments also suggested that once access roads are
improved, the tendency is for them to remain improved and for there to be increased
development pressure because of improved access. Cumulatively, the increased development
can have major impacts on wildlife habitat, movement patterns, and productivity. The
comments expressed special concern because much of the site is part of a major wildlife
corridor in the northern Rocky Mountains.
EPA is very cognizant of the concern about potential wildlife impacts. However, EPA is
charged with cleaning up the site so that current and potential human health and
environmental risks from exposure to hazardous substances are eliminated or reduced to
acceptable levels. Accomplishing that cleanup and meeting site performance standards will
require that many waste rock/tailings piles be excavated and removed and that AMD be
addressed. Roads will have to be improved or constructed for that purpose. EPA believes
that necessary water quality improvements and reduction of site risks can be accomplished
without significant unavoidable adverse impacts on wildlife.
-------
EPA recognizes that there are potential short-term (during construction) and long- term
risks to wildlife that may result from the construction and maintenance of access and haul
roads necessary to implement the selected remedy. There is also the potential for
increased sediment loading from the access roads to watershed streams. EPA intends to
address those potential risks during the remedial design phase of the project, which will
occur over a period of years as detailed plans and specifications for the various elements
of the selected remedy are prepared. EPA will work closely with USFS, wildlife resource
managers, DEQ, private property owners, and other interested parties to ensure that
wildlife resources are appropriately considered in the design process.
EPA's overall design approach will be to restrain construction disturbance to the minimum
amount necessary to complete the remedy. Road improvements, road width, tree removal, and
the excavation footprint area will be minimized to the degree possible. Most of the high-
priority mine sites at which action will be taken have relatively good access at present.
One of the key factors in scoring the sites as high priority was ease of excess, allowing
for easy exposure to site contaminants. EPA's action will attempt to minimize the need for
long- term O&M so that maintenance access roads will be unnecessary or minimal. EPA will
generally reclaim roads to pre-remedial conditions. Gated road closures and other travel
restrictions may also be appropriate to control use on roads that must remain in place.
EPA does not believe that its remedial action will determine the fate of private property
assets and future use of lands within the upper Tenmile Creek watershed. Superfund is not
the proper vehicle for defining, evaluating, discussing, and deciding future land
management and land use issues. Land and resource management decisions are appropriately
the responsibility of federal land managers, state wildlife managers, local governmental
entities, and private landowners. Those decisions, reguiring extensive public
participation and public comment and considering a wide range of issues, are beyond the
limited scope of Superfund. EPA will coordinate its actions with those parties to be
consistent with current and likely future land management uses and restrictions.
Potential Land Exchanges
Comments from the USFS and the City of Helena expressed an interest in consummating
ongoing efforts to effect a land exchange whereby the ownership of land currently owned by
the respective parties would be exchanged. National forest lands currently used under
permit by the city for its water collection and transmission system would be transferred
to the City of Helena. Property of egual value owned by the city within the watershed, but
not used by the city, would be transferred in exchange to the USFS. Key properties under
consideration in the exchange are the national forest lands on which the city's Chessman
Reservoir and the Red Mountain flume are located and the city's properties at the Banner
Creek tailings and Travis reservoir locations. The parties are proceeding with the land
exchange. EPA supports the effort.
Pi mini Community Water System
Numerous comments were received in support of the development of a community water system
for Rimini. Currently, most Rimini residences are served by individual wells, many of
which draw water from the contaminated alluvial aguifer underlying the community. Most
residents either treat the water with individual POU treatment systems or rely on bottled
water. On an interim basis until a final remedy can be implemented, EPA has provided
treatment systems to individual residences where maximum contaminant level concentrations
are exceeded. EPA's proposed plan recommended the construction of a new water system to
include deep wells, water tank storage, and new transmission and distribution piping.
EPA would construct the facility and the community would be responsible for operating and
maintaining it. Even though there was general support for the community water system, most
comments expressed concern over the potential costs of long term operation and maintenance
that the system users would have to bear, especially if few users were actually connected
to the system.
EPA indicated in the proposed plan and during community meetings that it would be willing
to construct a community water system for the Rimini area only if the community would
assume responsibility for the operation and maintenance of the system. Representatives of
-------
the community have met with various entities to gather information about forming a rural
water and sewer district and have formed an ad hoc committee to pursue the matter.
EPA has evaluated several alternatives for a community water system at the feasibility
study level, which includes estimation of system construction and O&M costs. Details for
the cost estimates for the different alternatives were presented in the FS and have since
been refined in the RI/FS addenda report. The purpose of the feasibility-level evaluation
is to compare a reasonable range of possible alternatives. The analysis assumed a
reasonable number of connections, given EPA's knowledge of the community, so that the
alternatives could be eguitably compared. Capital and O&M costs were estimated using sound
engineering costing principles and professional judgment.
EPA' s has selected the community water system alternative with the lowest long-term O&M
costs, since it is believed to be the most preferable system from the community's
perspective and the most likely alternative to be implementable and successful.
Detailed cost estimates for the remedy will be prepared during remedial design. EPA will
work with Rimini residents who are proceeding with plans to form a rural water and sewer
district to ensure that the designed system is appropriate for the community's need and
that the community can afford to operate and maintain the system. If the community is not
able to form a rural water district or determines that it cannot otherwise afford a
community water system, then EPA will have to implement remedy contingencies to provide
for individual POU treatment systems, which is considered to be a less protective remedy.
Institutional Controls and Controlled Groundwater Area
The selected remedy includes provisions for the establishment of institutional controls to
(1) provide for long-term protectiveness at locations where contaminated materials and
residual risks remain on site and (2) prevent the consumption of drinking water from
contaminated aguifers. For protection from residual risks from solid media, institutional
controls typically take the form of some sort of deed notice or restriction, permit
reguirement, or property easement that prevents or guides actions that might disturb or
remobilize waste materials or contaminants. To prevent consumption of contaminated
groundwater, a controlled groundwater area (CGWA) is usually established. EPA received a
number of comments addressing institutional controls.
Lewis and Clark County suggested that the ROD include provisions for institutional
controls so the county could enact specific controls for future development that would
prevent inappropriate disturbance of remediated mine sites and potential remobilization of
contaminants. The ROD includes such provisions, but also emphasizes the removal of
contaminated yard soils (to the full depth of contamination rather than only the uppermost
18 inches) to minimize the amount of residual contamination left in yards at residences
and occasional-use recreational cabins. Only inaccessible yard soils, such as those
underneath sidewalks, driveways, and buildings or near large trees, will be left in place.
Several comments reguested information about CGWA designations, such as the size of the
controlled areas, types of restrictions, etc. It is important to note that there is wide
latitude in establishing well restrictions under a CGWA. The final location, size, and
restrictions of the CGWA would be determined by the Montana Department of Natural
Resources and Conservation through a technical application and public review process.
Additional sampling and/or monitoring well installation may be necessary to establish the
CGWA. A CGWA does not necessarily mean that a "well ban" will be put in place; it may
simply reguire that newly installed wells be sampled and the water be treated or not
consumed for drinking water purposes if found to be contaminated. EPA expects that Rimini
residents would be able to use their current wells, or even drill new wells, for
irrigation purposes. From EPA's perspective, the importance of the CGWA is to prevent
uncontrolled drilling of wells in contaminated aguifer zones and the consumption of
contaminated groundwater.
-------
Acid Mine Drainage Flow Reduction and Treatment
The State of Montana, through DEQ, has consistently expressed concern over the potential
costs of long-term O&M of treatment facilities for AMD and emphasized the need to
implement source control and flow reduction actions. In the final proposed plan and ROD,
EPA has identified and included a new alternative AD4/5 to incorporate a four-phase
approach for remediating acid mine drainage. The approach, developed in consultation with
DEQ, contains the essential AMD remedy elements reguested by DEQ, primarily that all
appropriate efforts for source control and flow reduction be taken prior to implementation
of adit discharge treatment components, in order to minimize long- term O&M costs for
treatment. EPA agrees with that approach. However, EPA also believes that source control
and flow reduction alone will not be able to address all contaminant loading from AMD to
site streams. Current data indicate that some treatment of AMD will be reguired to meet
state ambient water guality standards. The ROD therefore recognizes that treatment of
residual adit discharge flows will be necessary and includes assumed treatment costs in
the remedy cost estimates. Specific details about treatment processes and reguirements
will not be developed until after all reasonable source control and flow reduction efforts
are exhausted.
Cleanup Action Levels for Lead
In the proposed plan, EPA's proposed remediation level for lead was 1,000 mg/kg, with a
target cleanup level of 800 mg/kg. Lewis and Clark County recommended that EPA reduce the
cleanup level to 400 mg/kg, to be consistent with EPA's Toxic Substances Control Act
(TSCA) Section 403 guidance lead cleanup and provide better long-term protection for
children within the site community.
The EPA TSCA guidance is not CERCLA-related and is intended for application where site
information or contaminant concentration data are not available. It was developed using
national default input parameters in the IEUBK model for lead exposure. For this site,
EPA's proposed remediation and target cleanup levels were developed also using the IEUBK
model, but refining its use with regional input parameters thought to be more appropriate
for the site. Conseguently, EPA has not changed the remediation levels for lead.
EPA also notes that the residential yard component of the selected remedy will be driven
primarily by the concentrations of arsenic in the yard soils. Preliminary remedial design
sample results for approximately 30 yards in Rimini indicate that nearly all yards will
have to be remediated because arsenic concentrations are greater than the cleanup level of
96 mg/kg.
Contaminated Roadway Materials Cleanup
Comments from one Rimini property owner and from Lewis and Clark County recommended that
EPA pave Rimini Road in Rimini to create an impermeable cap over the road waste materials,
instead of excavating and removing the wastes as proposed in the proposed plan. One
comment also suggested that EPA consider paving Rimini Road between the community of
Rimini and the turnoff to the Beaver Creek road (also known as the Chessman road).
Based on these comments, EPA reevaluated the alternatives for remediating the contaminated
roadway materials. EPA developed and evaluated alternatives that included paving either
5,000 feet or 7,000 feet of Rimini Road within the residential area of Rimini instead of
removing the uppermost 18 inches of the contaminated roadway materials. Paving would
essentially cap the contaminated materials with an impermeable layer of asphalt. EPA
considers the paving option to be a cost-effective approach for exposure control. However,
DEQ expressed concern over the potential for large flood events to wash out the road again
and redistribute the contaminated materials. To minimize the O&M needs and costs, EPA
developed an alternative consisting of removing all accessible contaminated roadway
material, estimated to be 8 to 10 feet deep in places. The selected remedy will include
removal of an accessible contaminated roadway material, with disposal in the Luttrell
repository. After the removal of contaminated materials, the road will be reconstructed
with appropriate clean subbase, base, and surface road materials.
-------
EPA does not believe that the portion of the road from the Beaver Creek road turnoff to
Rimini proper (approximately 2,500 feet) exhibits significant potential risk from
contaminated subsurface roadway materials. The potential risk is limited because the road
is on national forest lands that will not be residentially developed, effectively
preventing the potential for future residential setting exposure. Therefore, EPA does not
propose to either pave or remove road materials from that portion of the road. Paving of
that section of the road might be considered as part of a proposed Federal Highway
Administration project for paving Rimini Road south of U. S. Highway 12. That project,
however, has nothing to do with EPA's CERCLA action.
-------
APPENDIX A
Identification and Description of
Applicable or Relevant and Appropriate Requirements
Upper Tenmile Creek Mining Area Site
Lewis and Clark County, Montana
June 2002
-------
TABLE OF CONTENTS
SECTION PAGE
1. 0 INTRODUCTION A-l
2 . 0 TYPES OF ARARs A-3
3.0 CONTAMINANT-SPECIFIC ARARs A-5
3.1 Federal A-5
3.1.1 Safe Drinking Water Act A-5
3.1.2 Clean Water Act A-6
3.1.3 National Ambient Air Quality Standards A-6
3.2 State A- 6
3.2.1 Groundwater Protection A-6
3.2.2 Montana Water Quality Act A-8
3.2.3 Montana Ambient Air Quality Regulations A-ll
4.0 LOCATION-SPECIFIC ARARS A-13
4 .1 Federal A-13
4.1.1 National Historic Preservation Act A-13
4.1.2 Archaeological and Historic Preservation Act A-13
4.1.3 Historic Sites Act of 1935 A-13
4.1.4 Protection and Enhancement of the Cultural Environment A-13
4.1.5 The Archaeological Resources Protection Act of 1979 A-14
4.1.6 American Indian Religious Freedom Act A-14
4.1.7 Native American Graves Protection and Repatriation Act A-14
4.1.8 Fish and Wildlife Coordination Act A-14
4.1.9 Endangered Species Act A-14
4.1.10 Floodplain Management Regulations A-15
4.1.11 Protection of Wetlands Regulations A-15
4 .1.12 Clean Water Act A-15
4 .1.13 Migratory Bird Treaty Act A-15
4.1.14 Bald Eagle Protection Act A-15
4 .1.15 Resource Conservation and Recovery Act A-15
4.2 State A-16
4.2.1 Montana Antiguities Act A-16
4.2.2 Montana Human Skeletal Remains and Burial Site Protection Act A-16
4.2.3 Montana Floodplain and Floodway Management Act A-16
4.2.4 Montana Stream Protection Reguirements A-19
4.2.5 Montana Solid Waste Management Act A-20
5.0 ACTION-SPECIFIC ARARS A-21
5.1 Federal and State Water Protection Reguirements A-21
5.1.1 Clean Water Act A-21
5.1.2 Montana Pollutant Discharge Elimination System Reguirements A-21
5.1.3 Water Quality Statutes and Regulations A-21
5.1.4 Stormwater Runoff Control Reguirements A-22
5.2 Federal and State RCRA Subtitle C Reguirements A-23
5.3 Federal and State RCRA Subtitle D and Solid Waste Management Reguirements
A-24
5.3.1. Federal Reguirements A-24
5.3.2. State of Montana Solid Waste Reguirement A-25
5.4 Federal and State Mine Reclamation Reguirements A-26
5.4.1 Surface Mining Control and Reclamation Act A-26
5.4.2 Montana Statutory and Regulatory Reguirements A-21
5.5 Air Reguirements A-30
5. 6 Noxious Weeds A-30
-------
6.0 TO BE CONSIDERED (TBC) DOCUMENTS A-31
7.0 OTHER LAWS (NON-EXCLUSIVE LIST) A-33
7.1 Other Federal Laws A-33
7.2 Other State Laws A-33
-------
1.0 INTRODUCTION
Section 121 (d) of the Comprehensive Environmental Response, Compensation, and Liability
Act (CERCLA), 42 U. S. C. § 9621(d), the National Oil and Hazardous Substances Pollution
Contingency Plan (the "NCP") , 40 CFR Part 300 (1990), and guidance and policy issued by
the U. S. Environmental Protection Agency (EPA) reguire that remedial actions under CERCLA
comply with substantive provisions of applicable or relevant and appropriate standards,
reguirements, criteria, or limitations (ARARs) from State of Montana and federal
environmental laws and state facility siting laws during and at the completion of the
remedial action. These reguirements are threshold standards that any selected remedy must
meet, unless an ARAR waiver is invoked.
This document identifies final ARARs for the activities to be conducted under the Upper
Tenmile Mining Area Site remedial action. The following ARARs or groups of related ARARs
are each identified by a statutory or regulatory citation, followed by a brief explanation
of the ARAR and how and to what extent the ARAR is expected to apply to the activities to
be conducted under this remedial action.
Substantive provisions of the reguirements listed below are identified as ARARs pursuant
to 40 Code of Federal Regulations (CFR) § 300.400. ARARs that are within the scope of this
remedial action must be attained during and at the completion of the remedial action. 1 No
permits are anticipated for the remedial action for the Upper Tenmile Creek Mining Area
Site in accordance with Section 121 (e) of CERCLA.
1 40 CFR Section 300.435 ( b) (2); Preamble to the National Oil and Hazardous Substances
Pollution Contingency Plan, 55 Federal Register (FR) 8755-8757 (March 8,1990).
-------
2.0 TYPES OF ARARs
ARARs are either "applicable" or "relevant and appropriate." Both types of requirements
are mandatory under CERCLA and the NCP. 2 Applicable requirements are those cleanup
standards, standards of control, and other substantive requirements, criteria or
limitations promulqated under federal environmental or state environmental and facility
sitinq laws that specifically address a hazardous substance, pollutant, contaminant,
remedial action, location, or other circumstance found at a CERCLA site. Only those state
standards that are identified by a state in a timely manner and that are more strinqent
than federal requirements may be applicable. 3
Relevant and appropriate requirements are those cleanup standards, standards of control,
and other substantive requirements, criteria or limitations promulqated under federal
environmental or state environmental or facility sitinq laws that, while not "applicable"
to hazardous substances, pollutants, contaminants, remedial actions, locations, or other
circumstances at a CERCLA site, address problems or situations sufficiently similar to
those encountered at the CERCLA site that their use is well suited to the particular site.
Only those state standards that are identified in a timely manner and are more strinqent
than federal requirements may be relevant and appropriate. 4
The determination that a requirement is relevant and appropriate is a two- step process:
(1) determination if a requirement is relevant and (2) determination if a requirement is
appropriate. In qeneral, this involves a comparison of a number of site- specific factors,
includinq an examination of the purpose of the requirement and the purpose of the proposed
CERCLA action; the medium and substances requlated by the requirement and the proposed
requirement; the actions or activities requlated by the requirement and the remedial
action; and the potential use of resources addressed in the requirement and the remedial
action. When the analysis results in a determination that a requirement is both relevant
and appropriate, such a requirement must be complied with to the same deqree as if it were
applicable. 5
ARARs are contaminant, location, or action specific. Contaminant specific requirements
address chemical or physical characteristics of compounds or substances on sites. These
values establish acceptable amounts or concentrations of chemicals which may be found in
or discharqed to the ambient environment.
Location specific requirements are restrictions placed upon the concentrations of
hazardous substances or the conduct of cleanup activities because they are in specific
locations. Location specific ARARs relate to the qeoqraphical or physical positions of
sites, rather than to the nature of contaminants at sites.
Action specific requirements are usually technoloqy based or activity based requirements
or limitations on actions taken with respect to hazardous substances, pollutants or
contaminants. A qiven cleanup activity will triqqer an action specific requirement. Such
requirements do not themselves determine the cleanup alternative, but define how chosen
cleanup methods should be performed.
2 CERCLA § 121(d)(2)(A), 42 U.S.C. § 6921(d)(2)(a). See also, 40 CFR § 300.430(f)(1)(I)(A).
3 40 CFR § 300.5.
4 40 CFR § 300.5.
5 CERCLA Compliance with Other Laws Manual, Vol. I, OSWER Directive 9234.1-01, Auqust 8, 1988,
p. 1-11.
-------
Many requirements listed as ARARs are promulgated as identical or near identical
requirements in both federal and state law, usually pursuant to delegated environmental
programs administered by EPA and the state. The Preamble to the NCP provides that such a
situation results in citation to the state provision and treatment of the provision as a
federal requirement.
Also contained in this list are policies, guidance or other sources of information which
are "to be considered" in the selection of the remedy and implementation of the record of
decision (ROD). Although not enforceable requirements, these documents are important
sources of information which EPA and the State of Montana Department of Environmental
Quality (MDEQ) may consider during selection of the remedy, especially in regard to the
evaluation of public health and environmental risks; or which will be referred to, as
appropriate, in selecting and developing cleanup actions. 6
This Appendix constitutes EPA' s and MDEQ's formal identification and detailed description
of ARARs for the implementation of the remedial action at the Upper Tenmile Creek Mining
Area Site. Final ARARs will be set forth as performance standards for any and an remedial
design or remedial action work plans.
6 40 CFR Section 300.400(g)(3); 40 CFR Section 300.415(1); Preamble to the NCP, 55 Fed. Reg.
8744-8746 (March 8,1990).
-------
3.0 CONTAMINANT-SPECIFIC ARARs
3.1 Federal
3.1.1 Safe Drinking Water Act
Safe Drinking Water Act. 42 U.S.C. § 300f. et seer.. National Primary and. Secondary
Drinking Water Regulations. 40 CFR Parts 141 and 142 (relevant and appropriate) . The
National Primary and Secondary Drinking Water Regulations (40 CFR Parts 141 and 143)
establish maximum contaminant levels (MCL) for chemicals in drinking water distributed in
public water systems. These are enforceable in Montana under the Public Water Supplies,
Distribution, and Treatment Act and corresponding regulations, MCA § 75-6-101, et sea. ,
and ARM § 17.38.203. Safe Drinking Water Act MCLs are relevant and appropriate to the
Upper Tenmile Creek Mining Area Site remedial action because the aguifers found beneath
the Town of Rimini are currently a source for public water supplies. These standards may
be applicable in the future should EPA detect an exceedance at a public water outlet.
The determination that the drinking water standards are relevant and appropriate for
portions of the Upper Tenmile Creek Mining Area Site remedial action is fully supported by
the regulations and guidance. The Preamble to the NCP clearly states that the MCLs are
relevant and appropriate for groundwater that is a current or potential source of drinking
water. See 55 Fed. Reg. 8750, March 8, 1990, and 40 CFR § 300.430(e)(2)(I)(B). MCLs
developed under the Safe Drinking Water Act generally are ARARs for current or potential
drinking water sources. See, EPA Guidance On Remedial Action For Contaminated Groundwater
at Superfund Sites, OSWER Dir. #9283.1-2, December 1988.
In addition, maximum contaminant level goals (MCLG) may also be relevant and appropriate.
See 55 Fed. Reg. 8750-8752. MCLGs are health- based goals which are established at levels
at which no known or anticipated adverse effects on the health of persons occur and which
allow an adeguate margin of safety. According to the NCP, MCLGs that are set at levels
above zero must be attained by remedial actions for ground or surface waters that are
current or potential sources of drinking water. Where the MCLG for a contaminant has been
set at a level of zero, the MCL promulgated for that contaminant must be attained by the
remedial actions.
The MCLs and MCLGs for contaminants of concern are:
Contaminant MCL (mcr/L) MCLG a hng/L)
Antimony 0.006 0.006
Arsenic 0.01 NE
Cadmium 0.005 b 0.005 b
Copper 1. 3 c 1. 3 c
Iron 0.3 d NE
Lead 0.015 c 0
Manganese 0.05 d NE
Mercury 0.002 b 0
Silver NE NE
Thallium 0.002 b 0.0005
Zinc 5.0 d NE
NE - Not Established
a 40 CFR § 141.51(b)
b 40 CFR § 141.62(c)
c 40 CFR § 141.80(c) - No MCL, but specifies BAT to be applied.
d 40 CFR § 141.3 - Secondary MCL
3.1.2 Clean Water Act
Federal Surface Water Quality Recruirements, Clean Water Act, 33 USC § 1251, et seq.
-------
(applicable). As provided under Section 303 of the Clean Water Act, 33 U. S. C. § 1313,
the State of Montana has promulgated water quality standards. See the discussion
concerning State surface water quality requirements.
3.1.3 National Ambient Air Quality Standards
National Ambient Air Quality Standards. 40 CER § 50.6 (PM-10); 40 CFR § 50.12 (lead)
(applicable). These provisions establish standards for PM-10 and lead emissions to air.
(Corresponding state standards are found at ARM § 17.8.222 [lead] and ARM § 17.8.223
[PM-10].)
3.2 State
3.2.1 Groundwater Protection
ARM § 17.301005 (applicable) explains the applicability and basis for the groundwater
standards in ARM § 17.30.1006, which establish the maximum allowable changes in
groundwater quality and may limit discharges to groundwater.
ARM § 17.30.1006 (applicable) provides that groundwater is classified I through IV based
on its present and future most beneficial uses, and states that groundwater is to be
classified according to actual quality or use, whichever places the groundwater in a
higher class. Class I is the highest quality class; class IV the lowest. Based upon its
use as a public and private drinking water supply, groundwater throughout the entire Upper
Tenmile Creek Mining Area Site is considered Class I groundwater.
ARM § 17.30.1006 also sets the standards for the different classes of groundwater.
Concentrations of dissolved substances in Class I or II groundwater may not exceed the
human health standards listed in department Circular WQB-7. 7 These levels are listed
below for the primary contaminants of concern. Levels that are equal to or more stringent
than the MCL or MCLG identified in the federal portion of the ARARs are set out in
boldface type.
Contaminant WQB-7 Standard (ucr/L) a
Antimony 6
Arsenic 20
Cadmium 5
Copper 1,300
Iron NE b
Lead 15
Manganese NE b
Mercury 2
Silver 35
Thallium 2
Zinc 2,100
NE- Not Established
a WQB-7 standards for metals and arsenic in ground water are based on the dissolved
portion of the sample (after filtration through a 0.45 um membrane filter).
b Concentrations of iron and manganese must not reach values that interfere with the
uses specified in the surface and groundwater standards (ARM § 17.30.601 et seq.
and ARM § 17.30.1001 et seq.). The secondary maximum contaminant levels of 300
ug/L and 50 ug/L, respectively, may be considered guidance to determine levels that
will interfere with the specified uses.
7 Montana Department of Environmental Quality, Water Quality Division, Circular WQB- 7, Montana
Numeric Water Quality Standards (January 2002).
ARM § 17.30.1006 requires that concentrations of other dissolved or suspended substances
-------
must not exceed levels that render the waters harmful, detrimental or injurious to public
health. Maximum allowable concentrations of these substances also must not exceed acute or
chronic problem levels that would adversely affect existing or designated beneficial uses
of groundwater of that classification.
ARM § 17.30.1011 (applicable)
This section provides that any groundwater whose existing guality is higher than the
standard for its classification must be maintained at that high guality in accordance with
MCA § 75-5-303 and ARM Title 17, Chapter 30, Subchapter 7.
An additional concern with respect to ARARs for groundwater is the impact of groundwater
upon surface water. If significant loadings of contaminants from groundwater sources to
Tenmile Creek contribute to the inability of the stream to meet A-l and B-l class
standards, respectively, then alternatives to alleviate such groundwater loading must be
evaluated and, if appropriate, implemented. Groundwater in certain areas may have to be
remediated to levels more stringent than the groundwater classification standards in order
to achieve the standards for affected surface water. See Compliance with Federal Water
Quality Criteria, OSWER Publication 9234.2-09/FS (June 1990) (" Where the ground water
flows naturally into the surface water, the ground-water remediation should be designed so
that the receiving surface-water body will be able to meet any ambient water-guality
standards [such as State WQSs or FWQC] that may be ARARs for the surface water.")
3.2.2 Montana Water Quality Act
State of Montana Surface Water Quality Requirements, Montana Water Quality Act,
MCA § 75-5-101, et seer., and implementing regulations (applicable). General. The Clean
Water Act, 33 U.S.C. § 1251, et sea., provides the authority for each state to adopt water
guality standards (40 CFR Part 131) designed to protect beneficial uses of each water body
and reguires each state to designate uses for each water body. The Montana Water Quality
Act, MCA § 75-5-101, et seg. , establishes reguirements for restoring and maintaining the
guality of surface and groundwater. Montana's regulations classify State waters according
to guality, place restrictions on the discharge of pollutants to State waters, and
prohibit degradation of State waters. Pursuant to this authority and the criteria
established by Montana surface water guality regulations, ARM § 17.30.601, et seg.,
Montana has established the Water- Use Classification system. Under ARM § 17.30.610,
tributaries to the Missouri River have been classified "B-l". The Tenmile Creek drainage
to the Helena water supply intake has been classified under the more restrictive "A-l"
category. Ditches and certain other bodies of surface water must also meet these
reguirements. 8 Certain portions of the A-l and B-l standards, codified at ARM § 17.30.622
and ARM § 17.30.623, as well as Montana's nondegradation reguirements, are presented
below.
ABM § 17.30.622 (applicable). Waters classified A-l are, after conventional treatment for
removal of naturally present impurities, suitable for drinking, culinary and food
processing purposes. These waters are also suitable for bathing, swimming and recreation,
growth and propagation of salmonid fishes and associated aguatic life, waterfowl and
furbearers, and use for agricultural and industrial purposes. This section provides also
that concentrations of carcinogenic, bioconcentrating, toxic or harmful parameters which
would remain in water after conventional water treatment may not exceed standards set
forth in department circular WQB-7. WQB-7 provides that "whenever both Aguatic Life
Standards and Human Health Standards exist for the same analyte, the more restrictive of
these values will be used as the numeric Surface Water Quality Standard." For the primary
Contaminants of Concern the Circular WQB-7 standards are listed below.
8 As provided under ARM § 17.30.602(25), "' surface waters' means any waters on the earth's
surface, including but not limited to, streams, lakes, ponds, and reservoirs; and irrigation
and drainage systems discharging directly into a stream, lake, pond, reservoir or other surface
water. Water bodies used solely for treating, transporting or impounding pollutants shall not
be considered surface water."
-------
Montana WQB-7 Surface Water Quality Standards
Aquatic Life Standards
Human Health
Contaminant Acute Chronic Standards
(ug/L) (ug/L) (ug/L)
Aluminum a 750 87 NE
Antimony NE NE 6
Arsenic 340 150 18
Cadmium 2.lb/1.lc/0.52d 0.27b/0.16c/0.lOd 5
Copper 14b/7.3c/3.8d 9.3b/5.2c/2.8d 1,300
Iron e NE 1,000 NE
Lead 82b/34c/14d 3.2b/l.3c/0.54d 15
Manganese e NE NE NE
Mercury 1.7 0.91 0.05
Silver 4.1b/1.2c/0.37d NE 35
Thallium NE NE 1.7
Zinc 120b/67c/37d 120b/67c/37d 2,100
NE Not Established
a The aluminum standard is based on the dissolved fraction. All other parameters are
based on the total recoverable fraction.
b The aquatic life standard is based on hardness. Value shown is for a hardness of 100
mg/L as CaC03.
c The aguatic life standard is based on hardness. Value shown is for a hardness of 50
mg/L as CaC03.
d The aguatic life standard is based on hardness. Value shown is for a hardness of 25
mg/L as CaC03.
e Concentrations of iron and manganese must not reach values that interfere with the
uses specified in the surface and groundwater standards (ARM § 17.30.601 et seg.
and ARM § 17.30.1001 et seg.). The secondary maximum contaminant levels of 300 ug/L and 50
ug/L, respectively, may be considered guidance to determine levels that will interfere with
the specified uses.
The A-l classification standards at ARM § 17.30.622 also include the following criteria:
1) dissolved oxygen concentration must not be reduced below the levels given in department
circular WQB-7; 2) induced variation of hydrogen ion concentration (pH) within the range
of 6.5 to 8.5 must be less than 0.5 pH unit. Natural pH outside of this range must be
maintained without change. Natural pH above 7.0 must be maintained above 7.0; 3) no
increase above naturally occurring turbidity is allowed except as permitted in ARM §
17.30.637; 4) temperature increases must be kept within prescribed limits; 5) no increases
above naturally occurring concentrations of sediment, settleable solids, oils, floating
solids, which will or are likely to create a nuisance or render the waters harmful,
detrimental, or injurious to public health, recreation, safety, welfare, livestock, wild
animals, birds, fish or other wildlife are allowed; 6) true color must not be increased
more than two units above naturally occurring color.
ARM § 17.30.623 (applicable). Waters classified B- 1 are, after conventional treatment for
removal of naturally present impurities, suitable for drinking, culinary and food
processing purposes. These waters are also suitable for bathing, swimming and recreation,
growth and propagation of salmonid fishes and associated aguatic life, waterfowl and
furbearers, and use for agricultural and industrial purposes. This section provides also
that concentrations of carcinogenic, bioconcentrating, toxic or harmful parameters which
would remain in water after conventional water treatment may not exceed standards set
forth in department circular WQB-7. WQB-7 provides that "whenever both Aguatic Life
Standards and Human Health Standards exist for the same analyte, the more restrictive of
these values will be used as the numeric Surface Water Quality Standard.". These numerical
standards for the contaminants of concern are the same as for waters classified A-l.
-------
The B-l classification standards at ARM § 17.30.623 also include the following criteria:
1) dissolved oxygen concentration must not be reduced below the levels given in department
circular WQB-7; 2) induced variation of hydrogen ion concentration (pH) within the range
of 6.5 to 8.5 must be less than 0.5 pH unit. Natural pH outside of this range must be
maintained without change. Natural pH above 7.0 must be maintained above 7.0; 3) the
maximum allowable increase above naturally occurring turbidity is 5 nephelometric
turbidity units except as permitted in ARM § 17.30.637; 4) temperature increases must be
kept within prescribed limits; 5) no increases above naturally occurring concentrations of
sediment, settleable solids, oils, floating solids, which will or are likely to create a
nuisance or render the waters harmful, detrimental, or injurious to public health,
recreation, safety, welfare, livestock, wild animals, birds, fish or other wildlife are
allowed; 6) true color must not be increased more than five units above naturally
occurring color.
ARM § 17.30.637 (applicable). Provides that surface waters must be free of substances
attributable to industrial practices or other discharges that will: (a) settle to form
objectionable sludge deposits or emulsions beneath the surface of the water or upon
adjoining shorelines; (b) create floating debris, scum, a visible oil film (or be present
in concentrations at or in excess of 10 milligrams per liter) or globules of grease or
other floating materials; (c) produce odors, colors or other conditions which create a
nuisance or render undesirable tastes to fish flesh or make fish inedible; (d) create
concentrations or combinations of materials which are toxic or harmful to human, animal,
plant or aguatic life; (e) create conditions which produce undesirable aguatic life.
ARM § 17.30.637 also states that no waste may be discharged and no activities conducted
which, either alone or in combination with other waste activities, will cause violation of
surface water guality standards; provided a short term exemption from a surface water
guality standard may be authorized by the department for "emergency remediation
activities" under the conditions specified in § 75-5-308, MCA.
ARM § 17.30.705 (applicable). Existing and anticipated uses of surface water and water
guality necessary to support those uses must be maintained and protected.
3.2.3 Montana Ambient Air Quality Regulations
Montana Ambient Air Quality Regulations. ARM §§ 17.8.206.-. 222.-. 220. and -. 223
(applicable). The following provisions establish air guality standards.
ARM § 17.8.206. This provision establishes sampling, data collection, and analytical
reguirements to ensure compliance with ambient air guality standards.
ARM § 17.8.222. Lead emissions to ambient air shall not exceed a ninety (90) day average
of 1.5
micrograms per cubic liter of air.
ARM § 17.8.220. Settled particulate matter shall not exceed a thirty (30) day average of
10 grams per sguare meter.
ARM § 17.8.223. PM-10 concentrations in ambient air shall not exceed a 24 hour average of
150 micrograms per cubic meter of air and an annual average of 50 micrograms per cubic
meter of air.
4.0 LOCATION-SPECIFIC ARARS
The statutes and regulations set forth below relate to solid waste, floodplains,
floodways, streambeds, and the preservation of certain cultural, historic, natural or
other national resources located in certain areas that may be adversely affected by the
Upper Tenmile Creek Mining Area Site remedial action.
-------
4.1 Federal
4.1.1 National Historic Preservation Act
National Historic Preservation Act. 16 USC § 470. 40 CFR § 6.301(b). 36 CFR Part 63. Part
65, and Part 800 (NHPA) (applicable). This statute and implementing regulations reguire
Federal agencies to take into account the effect of this response action upon any
district, site, building, structure, or object that is included in or eligible for the
Register of Historic Places. Compliance with NHPA reguirements will be attained through
agreements entered into with EPA, the State of Montana, and the Town of Rimini during the
implementation of the remedial action.
4.1.2 Archaeological and Historic Preservation Act
Archaeological and Historic Preservation Act, 16 USC § 469, 40 CFR 6.30K c) (applicable).
This statute and implementing regulations establish reguirements for the evaluation and
preservation of historical and archaeological data, which may be destroyed through
alteration of terrain as a result of a Federal construction project or a federally
licensed activity or program. This reguires EPA or potentially responsible parties (PRP)
to survey the site for covered scientific, prehistorical or archaeological artifacts. The
results of this survey will be reflected in the Administrative Record. Preservation of
appropriate data concerning the artifacts is hereby identified as an ARAR reguirement, to
be completed during the implementation of the remedial action.
4.1.3 Historic Sites Act of 1935
Historic Sites Act of 1935. 16 USC § 461. et seer.. 40 CFR 6.310(a) (applicable). This
statute and implementing regulations reguire federal agencies to consider the existence
and location of land marks on the National Registry of National Landmarks and to avoid
undesirable impacts on such landmarks.
4.1.4 Protection and Enhancement of the Cultural Environment
Executive Order 11593 Protection and Enhancement of the Cultural Environment, 16 USC
§ 470 (applicable). Directs federal agencies to institute procedures to ensure programs
contribute to the preservation and enhancement of non- federally owned historic resources.
Consultation with the Advisory Council on Historic Preservation is reguired if remedial
activities should threaten cultural resources.
4.1.5 The Archaeological Resources Protection Act of 1979
The Archaeological Resources Protection Act of 1979. 16 USC §§ 470aa- 47011 (relevant
and appropriate). Reguires a permit for any excavation or removal of archeological
resources from public lands or Indian lands. Substantive portions of this act may be
relevant and appropriate if archeological resources are encountered during remedial action
activity.
4.1.6 American Indian Religious Freedom Act
American Indian Religious Freedom Act, 42 U.S.C. § 1996, et seq. (applicable). This Act
establishes a federal responsibility to protect and preserve the inherent right of
American Indians to believe, express and exercise the traditional religions of American
Indians. This right includes, but is not limited to, access to sites, use and possession
of sacred objects, and the freedom to worship through ceremonials and traditional rites.
The Act reguires Federal agencies to protect Indian religious freedom by refraining from
interfering with access, possession and use of religious objects, and by consulting with
Indian organizations regarding proposed actions affecting their religious freedom.
4.1.7 Native American Graves Protection and Repatriation Act
-------
Native American Graves Protection and Repatriation Act, 25 U.S.C. § 3001, et seq.
(applicable). The Act prioritizes ownership or control over Native American cultural
items, including human remains, funerary objects and sacred objects, excavated or
discovered on Federal or tribal lands. Federal agencies and museums that have possession
or control over Native American human remains and associated funerary objects are required
under the Act to compile an inventory of such items and, to the extent possible, identify
their geographical and cultural affiliation. Once the cultural affiliation of such objects
is established, the Federal agency or museum must expeditiously return such items, upon
request by a lineal descendent of the individual Native American or tribe identified.
4.1.8 Fish and Wildlife Coordination Act
Fish and Wildlife Coordination Act. 16 USC § 661. 40 CFR 6.302 (applicable). This statute
and implementing regulations require that Federal agencies or federally funded projects
ensure that any modification of any stream or other water body affected by any action
authorized or funded by the Federal agency provides for adequate protection of fish and
wildlife resources. Compliance with this ARAR requires EPA to consult with the U. S. Fish
and Wildlife Service and the Montana Department of Fish, Wildlife, and Parks. Further
consultation will occur during remedial design and remedial action.
4.1.9 Endangered Species Act
Endangered Species Act. 16 USC § 1531. 50 CFR Parts 17 and 402 (applicable). This statute
and implementing regulations provide that federal activities not jeopardize the continued
existence of any threatened or endangered species. The remedy selection process, including
the Feasibility Study, should identify whether the proposed remedial actions will impact
threatened and/or endangered species and/or their habitat, and what avoidance or
mitigative measures are necessary.
4.1.10 Floodplain Management Regulations
Floodplain Management Recrulations, Executive Order No. 11988 and 40 CFR § 6.302(b)
(applicable). These require that actions be taken to avoid, to the extent possible,
adverse effects associated with direct or indirect development of a floodplain, or to
minimize adverse impacts if no practicable alternative exists.
4.1.11 Protection of Wetlands Regulations
Protection of Wetlands Recrulations, 40 CFR Part 6, Appendix A, and Executive Order No.
11990 (applicable). This ARAR requires avoidance of the adverse impacts associated with
the destruction or loss of wetlands to the extent possible and avoidance of new
construction in wetlands if a practicable alternative exists. Wetlands are defined as
those areas that are inundated or saturated by groundwater or surface water at a frequency
and duration sufficient to support, and that under normal circumstances do support, a
prevalence of vegetation typically adapted for life in saturated soil conditions.
Compliance with this ARAR will be achieved through consultation with the U. S. Fish and
Wildlife Service and the U. S. Army Corps of Engineers, to determine the existence and
category of wetlands present at the site, and any avoidance or mitigation and replacement
which may be necessary.
4.1.12 Clean Water Act
Section 404. Clean Water Act. 33 USC §§ 1251 et seq.. 33 CFR Part 330 (applicable).
Regulates discharge of dredged or fill materials into waters of the United States.
Substantive requirements of portions of Nationwide Permit No. 38 (General and Specific
Conditions) are applicable to the Upper Tenmile Creek Mining Area Site remedial activities
conducted within waters of the United States.
4.1.13 Migratory Bird Treaty Act
-------
Migratory Bird Treaty Act, 16 USC § 703, et seq. (applicable). This requirement
establishes a federal responsibility for the protection of the international migratory
bird resource and requires continued consultation with the USFWS durinq remedial desiqn
and remedial construction to ensure that the cleanup of the site does not unnecessarily
impact miqratory birds. Specific mitiqative measures may be identified for compliance with
this requirement.
4.1.14 Bald Eagle Protection Act
Bald Eagle Protection Act, 16 USC § 668, et seq. (applicable). This requirement
establishes a federal responsibility for protection of bald and qolden eaqles, and
requires continued consultation with the U. S. Fish and Wildlife Service durinq remedial
desiqn and remedial construction to ensure that any cleanup of the site does not
unnecessarily adversely affect the bald and qolden eaqles. Specific mitiqative measures
may be identified for compliance with this requirement.
4.1.15 Resource Conservation and Recovery Act
Resource Conservation and Recovery Act and regulations, 40 CER § 264.18 (a) and (b)
(relevant and appropriate). These requlations provide seismic and floodplain restrictions
on the location of a waste manaqement unit.
4.2 State
4.2.1 Montana Antiquities Act
Montana Antictuities Act, MCA § 22-3-421, et seq., (relevant and appropriate). The
Montana Antiquities Act addresses the responsibilities of State aqencies reqardinq
historic and prehistoric sites includinq buildinqs, structures, paleontoloqical sites,
archaeoloqical sites on state owned lands. Each State aqency is responsible for
establishinq rules reqardinq historic resources under their jurisdiction which address
National Reqister eligibility, appropriate permitting procedures and other historic
preservation qoals. The State Historic Preservation Office maintains information related
to the responsibilities of State Aqencies under the Antiquities Act.
4.2.2 Montana Human Skeletal Remains and Burial Site Protection Act
Montana Human Skeletal Remains and Burial Site Protection Act (1991). MCA § 22-3-801
(applicable). The Human Skeletal Remains and Burial Site Protection Act is the result of
years of work by Montana Tribes, State aqencies and orqanizations interested in assurinq
that all qraves within the State of Montana are adequately protected. If human skeletal
remains or burial site are encountered durinq remedial activities at the Upper Tenmile
Creek Mininq Area Site, then requirements will be applicable.
4.2.3 Montana Floodplain and Floodway Management Act
Montana Floodplain and Floodwav Management Act and Regulations, MCA § 76-5-401, et
seq., ARM § 36.15.601, et seq.. (applicable). The Floodplain and Floodway Manaqement Act
and requlations specify types of uses and structures that are allowed or prohibited in the
desiqnated 100-year floodway 9 and floodplain. 10 Since the Upper Tenmile Creek Mininq
Area Site may lie partially within the 100-year floodplain of Tenmile Creek, these
standards are applicable to all actions within these floodplain areas.
9 The "floodway" is the channel of a watercourse or drainway and those portions of the
floodplain adjoininq the channel that are reasonably required to carry and discharqe the
floodwater of the watercourse or drainway. ARM § 36.15.101(13).
10 The "floodplain" is the area adjoininq the watercourse or drainway that would be covered by
the floodwater of a base (100-year) flood except for sheetflood areas that receive less than
one foot of water per occurrence. The floodplain consists of the floodway and flood frinqe.
-------
A. Allowed uses. The law recognizes certain uses as allowable in the floodway and a
broader range of uses as allowed in the floodplain. Residential use is among the possible
allowed uses expressly recognized in both the floodway and floodplain. "Residential uses
such as lawns, gardens, parking areas, and play areas," as well as certain agricultural,
industrial-commercial, recreational and other uses are permissible within the designated
floodway, provided they do not reguire structures other than portable structures, fill or
permanent storage of materials or eguipment. MCA § 76-5-401; ARM § 36.15.601 (Applicable).
In addition, in the flood fringe (i.e., within the floodplain but outside the floodway),
residential, commercial, industrial, and other structures may be permitted subject to
certain conditions relating to placement of fill, roads, floodproofing, etc. MCA §
76-5-402; ARM § 36.15.701 (Applicable). Domestic water supply wells may be permitted, even
within the floodway, provided the well casing is watertight to a depth of 25 feet and the
well meets certain conditions for floodproofing, sealing, and positive drainage away from
the well head. ARM § 36.15.602(6).
B. Prohibited uses. Uses prohibited anywhere in either the floodway or the floodplain are:
• solid and hazardous waste disposal; and
• storage of toxic, flammable, hazardous, or explosive materials.
ARM §§ 36.15.605(2) and 36.15.703 (Applicable); see also ARM § 36.15.602(5)(b)
(Applicable).
In the floodway, additional prohibitions apply, including prohibition of:
• a building for living purposes or place of assembly or permanent use by human
beings;
• any structure or excavation that will cause water to be diverted from the
established floodway, cause erosion, obstruct the natural flow of water, or
reduce the carrying capacity of the floodway; and
• the construction or permanent storage of an object subject to flotation or
movement during flood level periods.
MCA § 76-5-402 (Applicable).
C. Applicable considerations in use of floodplain or floodwav. Applicable regulations also
specify factors that must be considered in allowing diversions of the stream, changes in
place of diversion of the stream, flood control works, new construction or alteration of
artificial obstructions, or any other nonconforming use within the floodplain or floodway.
Many of these reguirements are set forth as factors that must be considered in determining
whether a permit can be issued for certain obstructions or uses. While permit reguirements
are not directly applicable to remedial actions conducted entirely on site, the
substantive criteria used to determine whether a proposed obstruction or use is
permissible within the floodway or floodplain are applicable standards. Factors which must
be considered in addressing any obstruction or use within the floodway or floodplain
include:
• the danger to life and property from backwater or diverted flow caused by the
obstruction or use;
• the danger that the obstruction or use will be swept downstream to the injury
of others;
• the availability of alternate locations;
• the construction or alteration of the obstruction or use in such a manner as
to lessen the danger;
-------
• the permanence of the obstruction or use; and
• the anticipated development in the foreseeable future of the area which may be
affected by the obstruction or use.
See MCA § 76-5-406; ARM § 36.15.216 (Applicable, substantive provisions only). Conditions
or restrictions that generally apply to specific activities within the floodway or
floodplain are:
• the proposed activity, construction, or use cannot increase the upstream
elevation of the 100-year flood a significant amount (% foot or as otherwise
determined by the permit issuing authority) or significantly increase flood
velocities, ARM § 36.15.604 (Applicable, substantive provisions only); and
• the proposed activity, construction, or use must be designed and constructed
to minimize potential erosion.
For the substantive conditions and restrictions applicable to specific obstructions or
uses, see the following applicable regulations:
Excavation of material from pits or pools - ARM § 36.15.602(1).
Water diversions or changes in place of diversion - ARM § 36.15.603.
Flood control works (levees, floodwalls, and riprap must comply with specified
safety standards) - ARM § 36.15.606.
Roads, streets, highways and rail lines (must be designed to minimize increases in
flood heights) - ARM § 36.15.701(3)(c).
Structures and facilities for liguid or solid waste treatment and disposal (must be
floodproofed to ensure that no pollutants enter flood waters and may be allowed
and approved only in accordance with Montana Department of Environmental
Quality (MDEQ) regulations, which include certain additional prohibitions on
such disposal) - ARM § 36.15.701 (3) (d) .
Residential structures -ARM § 36.15.702(1).
Commercial or industrial structures - ARM § 36.15.702(2).
4.2.4 Montana Stream Protection Requirements
Montana Natural Streambed and Land Preservation Act and Recrulations, MCA § 75-7-101, et.
seq., and ARM §§ 36.2.401, et. seq., (applicable). Applicable if this remedial action
alters or affects a streambed or its banks. The adverse effects of any such action must be
minimized.
ARM 36.2.410 (Applicable) establishes minimum standards which would be applicable if a
response action alters or affects a streambed, including any channel change, new
diversion, riprap or other streambank protection project, jetty, new dam or reservoir or
other commercial, industrial or residential development. Projects must be designed and
constructed using methods that minimize adverse impacts to the stream (both upstream and
downstream) and future disturbances to the stream. All disturbed areas must be managed
during construction and reclaimed after construction to minimize erosion. Temporary
structures used during construction must be designed to handle high flows reasonably
anticipated during the construction period. Temporary structures must be completely
removed from the stream channel at the conclusion of construction, and the area must be
restored to a natural or stable condition. Channel alterations must be designed to retain
original stream length or otherwise provide hydrologic stability. Streambank vegetation
must be protected except where removal of such vegetation is necessary for the completion
-------
of the project. When removal of vegetation is necessary, it must be kept to a minimum.
Riprap, rock, and other material used in a project must be of adequate size, shape, and
density and must be properly placed to protect the streambank from erosion. The placement
of road fill material in a stream, the placement of debris or other materials in a stream
where it can erode or float into the stream, projects that permanently prevent fish
migration, operation of construction equipment in a stream, and excavation of streambed
gravels are prohibited unless specifically authorized by the district. Such projects must
also protect the use of water for any useful or beneficial purpose. See § 75-7-102, MCA.
While the administrative/procedural requirements, including the consent and approval
requirements, set forth in these statutes and regulations are not ARARs, the party
designing and implementing the response action is encouraged to continue to consult with
the Montana Department of Fish, Wildlife and Parks and any conservation district or board
of county commissioners (or consolidated city/county government) as provided in the
referenced statutes, to assist in the evaluation of factors discussed above.
MCA §§ 87-5-502 and 504 (Applicable — substantive provisions only). provide that a state
agency or subdivision shall not construct, modify, operate, maintain or fail to maintain
any construction project or hydraulic project which may or will obstruct, damage,
diminish, destroy, change, modify, or vary the natural existing shape and form of any
stream or its banks or tributaries in a manner that will adversely affect any fish or game
habitat. The requirement that any such project must eliminate or diminish any adverse
effect on fish or game habitat is applicable to the state in approving remedial actions to
be conducted. The Natural Streambed and Land Preservation Act of 1975, MCA § 75-7-101, et
seq., (Applicable -- substantive provisions only) includes similar requirements and is
applicable to private parties as well as government agencies.
Consultation with the Montana Department of Fish, Wildlife and Parks, and any conservation
district or board of county commissioners (or consolidated city/county government) is
encouraged during the designing and implementing of the remedial action for the Upper
Tenmile Creek Mining Area Site.
4.2.5 Montana Solid Waste Management Act
Montana Solid Waste Management Act and recrulations, MCA § 75-10-201, et seq., ARM §
17.50.505 (applicable). Sets forth requirements applying to the location of any solid
waste management facility. Among other things, the location must have sufficient acreage,
must not be within a 100-year floodplain, must be located so as to prevent pollution of
ground, surface, and private and public water supply systems, and must allow for
reclamation of the land. These standards apply to any facility for the treatment, storage,
or disposal of mine wastes, including, for example, any mine waste repository, tailings
deposit, or waste rock pile that is actively managed as part of a response action.
5.0 ACTION-SPECIFIC ARARS
5.1 Federal and State Water Protection Requirements
5.1.1 Clean Water Act
Clean Water Act, Point Source Discharges recruirements, 33 USC § 1342 (applicable,
substantive provisions only). Section 402 of the Clean Water Act, 33 USC § 1342, et sea.,
authorizes the issuance of permits for the "discharge" of any "pollutant." This includes
storm water discharges associated with "industrial activity." See, 40 CFR § 122.1 ( b) ( 2) (
iv). "Industrial activity includes inactive mining operations that discharge storm water
contaminated by contact with or that has come into contact with any overburden, raw
material, intermediate products, finished products, byproducts or waste products located
on the site of such operations, see, 40 CFR § 122.26(b) (14) (iii) ; landfills, land
application sites, and open dumps that receive or have received any industrial wastes
including those subject to regulation under RCRA subtitle D, see 40 CFR §122.26(b)(14)(v);
and construction activity including clearing, grading, and excavation activities, see, 40
-------
CFR § 122.26 (b) (14) (x) . Because the State of Montana has been delegated the authority to
implement the Clean Water Act, these requirements are enforced in Montana through the
Montana Pollutant Discharge Elimination System (MPDES). The MPDES requirements are set
forth below.
5.1.2 Montana Pollutant Discharge Elimination System Requirements
Substantive MPDES Permit Requirements. ARM §§ 17.30.1342-1344 (applicable). These set
forth the substantive requirements applicable to all MPDES and National Pollutant
Discharge Elimination System (NPDES) permits. The substantive requirements, including the
requirement to properly operate and maintain all facilities and systems of treatment and
control are applicable requirements.
Technology-Based Treatment. ARM §§ 17.30.1203 and 1344 (applicable). Provisions of 40
CFR Part 125 for criteria and standards for the imposition of technology-based treatment
requirements are adopted and incorporated in MDEQ permits. Although the permit requirement
would not apply to on-site discharges, the substantive requirements of Part 125 are
applicable, i.e., for toxic and nonconventional pollutants treatment must apply the best
available technology economically achievable (BAT) ; for conventional pollutants,
application of the best conventional pollutant control technology (BCT) is required. Where
effluent limitations are not specified for the particular industry or industrial category
at issue, BCT/BAT technology- based treatment requirements are determined on a case by
case basis using best professional judgment (BPJ). See CERCLA Compliance with Other Laws
Manual, Vol. I, August 1988, p. 3-4 and 3-7.
5.1.3 Water Quality Statutes and Regulations
Causing of Pollution, MCA § 75-5-605 (applicable). This section of the Montana Water
Quality Act prohibits the causing of pollution of any state waters. Pollution is defined
as contamination or other alteration of physical, chemical, or biological properties of
state waters which exceeds that permitted by the water quality standards. Also, it is
unlawful to place or caused to be placed any wastes where they will cause pollution of any
state waters. Any permitted placement of waste is not placement if the agency's permitting
authority contains provisions for review of the placement of materials to ensure it will
not cause pollution to state waters.
Nondegradation, MCA § 75-5-303 (applicable). This provision states that existing uses of
state waters and the level of water quality necessary to protect the uses must be
maintained and protected. Section MCA § 75-5-317 provides an exemption from nondegradation
requirements which allows changes of existing water quality resulting from an emergency or
remedial activity that is designed to protect the public health or the environment and
that is approved, authorized, or required by the department. Degradation meeting these
requirements may be considered nonsignificant. In determining that remedial actions are
protective of public health and the environment and in approving, authorizing, or
requiring such remedial activities, no significant degradation should be approved.
ARM § 17.30.705 (applicable). This provides that for any surface water, existing and
anticipated uses and the water quality necessary to protect these uses must be maintained
and protected unless degradation is allowed under the nondegradation rules at ARM §
17.30.708.
ARM § 17.30.1011 (applicable). This provides that any groundwater whose existing quality
is higher than the standard for its classification must be maintained at that high quality
unless degradation may be allowed under the principles established in MCA § 75-5-303, and
the nondegradation rules at ARM § 17.30.701, et sea.
5.1.4 Stormwater Runoff Control Requirements
ARM § 17.24.633 (applicable). All surface drainage from a disturbed area must be treated
by the best technology currently available.
-------
General Permits (applicable). Under ARM § 17.30.601, et sea., and ARM § 17.30.1301, et
sea., including ARM § 17.30.1332, the Water Quality Division has issued general storm
water permits for certain activities. The substantive reguirements of the following
permits are applicable for the following activities: for construction activities - General
Permit for Storm Water Discharge Associated with Construction Activity, Permit No.
MTR100000 (June 8, 2002); for mining activities - General Discharge Permit for Storm Water
Associated with Mining and with Oil and Gas Activities, Permit No. MTR300000 (September
10, 1997) ; 11 and for industrial activities - General Permit for Storm Water Discharge
Associated with Industrial Activity, Permit No. MTROOOOOO (October 1, 2001) . 12
Generally, the permits reguire the permittee to implement best management practice (BMP)
and to take all reasonable steps to minimize or prevent any discharge which has a
reasonable likelihood of adversely affecting human health or the environment. However, if
there is evidence indicating potential or realized impacts on water guality due to any
storm water discharge associated with the activity, an individual MPDES permit or
alternative general permit may be reguired.
Surface Water, ARM § 17.30.637 (applicable). Prohibits discharges containing substances
that will: (a) settle to form objectionable sludge deposits or emulsions beneath the
surface of the water or upon adjoining shorelines; (b) create floating debris, scum, a
visible oil film (or be present in concentrations at or in excess of 10 milligrams per
liter) or globules of grease or other floating materials; (c) produce odors, colors or
other conditions which create a nuisance or render undesirable tastes to fish flesh or
make fish inedible; (d) create concentrations or combinations of materials which are toxic
or harmful to human, animal, plant or aguatic life; or (e) create conditions which produce
undesirable aguatic life.
5.2 Federal and State RCRA Subtitle C Requirements
Federal and State RCRA. Subtitle C Requirements, 42 U. S. C. Section 6921, et seq.
(relevant and appropriate for solid wastes, applicable for hazardous wastes). The
presentation of RCRA Subtitle C reguirements in this section assumes that there will be
many solid wastes at the Upper Tenmile Creek Mining Area Site and that some of these may
be left in place in "waste management areas" as a result of a remedial action. Because of
the similarity of these waste management areas to the RCRA "' waste management unit,"
certain discrete portions of the RCRA Subtitle C implementing regulations will be relevant
and appropriate for the Upper Tenmile Creek Mining Area Site remedial action. RCRA
Subtitle C and implementing regulations are designated as applicable for any hazardous
wastes that are actively "generated" as part of the Upper Tenmile Creek Mining Area Site
remedial action or that were "placed" or "disposed" after 1980. Also, should hazardous
wastes be discovered as part of any remedial design or remedial action, EPA reserves the
right to identify RCRA Subtitle C reguirements in more detail at a later date. All federal
RCRA Subtitle C reguirements set forth below are incorporated by reference as State of
Montana reguirements as provided for under ARM § 17.54.112( 6) unless mentioned otherwise
below.
11 This permit covers point source discharges of storm water from mining and milling activities
(including active, inactive, and abandoned mine and mill sites) including activities with
Standard Industrial Code 14 (metal mining).
12 Industrial activities are defined as all industries defined in 40 CFR §§ 122, 123, and 124,
excluding construction, mining, oil & gas extraction activities and storm water discharges
subject to effluent limitations guidelines. This includes wood treatment operations, as well as
the production of slag.
-------
40 CER Part 264 Subpart F.
General Facility Standards. These are potentially relevant and appropriate for solid
wastes at this site. Any waste management unit or similar area would be required to comply
with the following requirements.
40 CFR § 264.92, .93. and .94. Prescribes groundwater protection standards.
40 CFR § 264.97. Prescribes general groundwater monitoring requirements.
40 CFR § 264.98. Prescribes requirements for monitoring and detecting indicator
parameters.
Closure requirements.
40 CFR § 264.111. This provides that the owner or operator of a hazardous waste
management facility must close the facility in a way that minimizes the need for
further maintenance, and controls or eliminates the leaching or escape of hazardous
waste or its constituents, leachate, or runoff to the extent necessary to protect
human health and the environment.
40 CFR § 264.117. This provision incorporates monitoring requirements in Part 264,
including those mentioned at Part 264.97 and Part 264.303. It governs the length of
the post-closure care period, permits a lengthened security period, and prohibits
any use of the property which would disturb the integrity of the management
facility.
40 CFR § 264.310. This specifies requirements for caps, maintenance, and monitoring
after closure.
40 CFR § 264.301. Prescribes design and operating requirements for landfills.
40 CFR § 264.301(a). This provides for a single liner and leachate collection and
removal system.
40 CFR § 264.301(f). This requires a run-on control system.
40 CFR § 264.301 (cr) . This requires a run-off management system.
40 CFR § 264.301(h). This requires prudent management of facilities for collection
and holding of run-on and run-off.
40 CFR § 264.301(i). This requires that wind dispersal of particulate matter be
controlled.
5.3 Federal and State RCRA Subtitle D and Solid Waste Management Requirements
40 CFR Part 257 establishes criteria under Subtitle D of the Resource Conservation and
Recovery Act for use in determining which solid waste disposal facilities and practices
pose a reasonable probability of adverse effects on health or the environment. See 40 CFR
§ 257.1(a). This part comes into play whenever there is a "disposal" of any solid or
hazardous waste from a "facility." "Disposal" is defined as "the discharge, deposit,
injection, dumping, spilling, leaking, or placing of any solid waste or hazardous waste
into or on any land or water so that such solid waste or hazardous waste or any
constituent thereof may enter the environment or be emitted into the air or discharged
into any waters, including ground waters." See 40 CFR § 257.2. "Facility" means " any land
and appurtenances thereto used for the disposal of solid wastes." Solid waste requirements
are listed herein because mine wastes to be addressed in the remedial action are
considered solid waste.
-------
5.3.1. Federal Requirements
40 CFR § 257 (applicable). Criteria for Classification of Solid Waste Disposal Facilities
and Practices. The activities to be performed for the Upper Tenmile Creek Mining Area Site
remedial action are expected to comply with the following requirements.
40 CFR § 257.3-1. Washout of solid waste in facilities in a floodplain posing a
hazard to human life, wildlife, or land or water resources shall not occur.
40 CFR § 257.3-2. Facilities shall not contribute to the taking of endangered
species or the endangering of critical habitat of endangered species.
40 CFR § 257.3-3. A facility shall not cause a discharge of pollutants, dredged or
fill material, into waters of the United States in violation of Sections 402 and 404
of the Clean Water Act, as amended, and shall not cause non- point source pollution,
in violation of applicable legal requirements implementing an area wide or statewide
water quality management plan that has been approved by the Administrator under
Section 208 of the Clean Water Act, as amended.
40 CFR § 257.3-4. A facility shall not contaminate an underground source of drinking
water beyond the solid waste boundary or beyond an alternative boundary specified in
accordance with this section.
40 CFR § 257.3-8(d). Access to a facility shall be controlled so as to prevent
exposure of the public to potential health and safety hazards at the site.
5.3.2. State of Montana Solid Waste Requirements.
The Montana Solid Waste Management Act § 75-10-201 et seq. , MCA, and regulations are
applicable to the management and disposal of all solid wastes, including mine wastes at
sites that are not currently subject to operating permit requirements.
ARM § 17.50.505(1) and (2)(applicable). Sets forth standards that all solid waste disposal
sites must meet, including the requirements that (1) Class II landfills must confine solid
waste and leachate to the disposal facility. If there is the potential for leachate
migration, it must be demonstrated that leachate will only migrate to underlying
formations which have no hydraulic continuity with any state waters; (2) adequate
separation of group II wastes from underlying or adjacent water must be provided; and (3)
no new disposal units or lateral expansions may be located in wetlands. ARM § 17.50.505
also specifies general soil and hydrogeological requirements pertaining to the location of
any solid waste management facility.
ARM § 17.50.506 (applicable). Specifies design requirements for landfills. Landfills must
either be designed to ensure that MCLs are not exceeded or the landfill must contain a
composite liner and leachate collection system which comply with specified criteria.
ARM § 17.50.510 (applicable). Sets forth general operational and maintenance and design
requirements for solid waste facilities using land filling methods. Specific operational
and maintenance requirements specified in ARM § 17.50.510 that are applicable are run- on
and run-off control systems requirements, requirements that sites be fenced to prevent
unauthorized access, and prohibitions of point source and nonpoint source discharges which
would violate Clean Water Act requirements.
MCA § 75-10-212 and ARM § 17.50.523 (applicable). For solid wastes, MCA § 75-10-212
prohibits dumping or leaving any debris or refuse upon or within 200 yards of any highway,
road, street, or alley of the State or other public property, or on privately owned
property where hunting, fishing, or other recreation is permitted. ARM § 17.50.523
specifies that solid waste must be transported in such a manner as to prevent its
discharge, dumping, spilling or leaking from the transport vehicle.
-------
MCA § 75-10-206 (applicable). Provides for a variance from certain solid waste
requirements where such variance would not result in a danger to public health or safety.
Certain of the solid waste regulations regarding design of landfills, ARM 17.50.506,
operational and maintenance requirements, ARM 17.50.510, and landfill closure requirements
and post-closure care, ARM 17.50.530-531 may be subject to variance, if the requirements
of § 75-10-206, MCA, are met.
ARM § 17.50.530 (applicable). Sets forth the closure requirements for landfills. Class II
landfills must meet the following criteria: (1) install a final cover that is designed to
minimize infiltration and erosion; (2) design and construct the final cover system to
minimize infiltration through the closed unit by the use of an infiltration layer that
contains a minimum 18 inches of earthen material and has a permeability less than or equal
to the permeability of any bottom liner, barrier layer, or natural subsoils or a
permeability no greater than 1 X 10-5 cm/sec, whichever is less; (3) minimize erosion of
the final cover by the use of a seed bed layer that contains a minimum of six inches of
earthen material that is capable of sustaining native plant growth and protecting the
infiltration layer from frost effects and rooting damage; (4) revegetate the final cover
with native plant growth within one year of placement of the final cover.
ARM § 17.50.531 (applicable). Sets forth post closure care requirements for Class II
landfills. Post closure care must be conducted for a period sufficient to protect human
health and the environment. Post closure care requires maintenance of the integrity and
effectiveness of any final cover, including making repairs to the cover as necessary to
correct the effects of settlement, subsidence, erosion, or other events, and preventing
run- on and run- off from eroding or otherwise damaging the cover and comply with the
groundwater monitoring requirements found at ARM Title 17, chapter 50, subchapter 7.
5.4 Federal and State Mine Reclamation Requirements
5.4.1 Surface Mining Control and Reclamation Act
Surface Mining Control and Reclamation Act. 30 USC §§ 1201- 1326 (relevant and
appropriate). This Act and implementing regulations found at 30 CFR Parts 784 and 816
establish provisions designed to protect the environment from the effects of surface coal
mining operations, and to a lesser extent non- coal mining. These requirements are
relevant and appropriate to the covering of discrete areas of contamination. The
regulations require that revegetation be used to stabilize soil covers over reclaimed
areas. They also require that revegetation be done according to a plan which specifies
schedules, species which are diverse and effective, planting methods, mulching techniques,
irrigation if appropriate, and appropriate soil testing. Reclamation performance standards
are currently relevant and appropriate to mining waste sites.
5.4.2 Montana Statutory and Regulatory Requirements
Montana Strip and Underground Mine Reclamation Act, MCA § 82-4-201, et seq. (relevant
and appropriate). Certain portions of the following statutory or regulatory provisions, as
identified below, are relevant and appropriate requirements.
MCA § 82-4-231. Requires operators to reclaim and revegetate affected lands using most
modern technology available. Operators must grade, backfill, topsoil, reduce high walls,
stabilize subsidence, control water, minimize erosion, subsidence, land slides, and water
pollution.
MCA § 82-4-233. Operators must plant vegetation that will yield a diverse, effective, and
permanent vegetative cover of the same seasonal variety native to the area and capable of
self-regeneration.
Montana Metal Mining Reclamation Act, MCA § 82-4-301, et seq. (relevant and appropriate).
Certain portions of the following statutory or regulatory provisions, as identified
below, are relevant and appropriate requirements.
-------
MCA § 82-4-336. Disturbed areas must be reclaimed to utility and stability comparable to
areas adjacent.
ARM § 17.24.501. Provides general backfilling and grading requirements. Backfill must be
placed so as to minimize sedimentation, erosion, and leaching of acid or toxic materials
into waters, unless otherwise approved. Final grading must be to the approximate original
contour of the land and final slopes must be graded to prevent slope failure, may not
exceed the angle of repose, and must achieve a minimum long term static safety factor of
1:3. The disturbed area must be blended with surrounding and undisturbed ground to provide
a smooth transition in topography.
ARM § 17.24.519. Requires monitoring of settling of regraded areas, and potential
modification of reclamation, spoiling and grading techniques to alleviate uneven settling
problems. Pertinent areas of the Upper Tenmile Creek Mining Area Site where excavation
will occur will be regraded to minimize settlement.
ARM § 17.24.631(1).(2).(3)(a) and (b). Requires minimization of disturbances to the
prevailing hydrologic balance. Changes in water quality and quantity, in the depth to
groundwater and in the location of surface water drainage channels will be minimized, to
the extent consistent with the selected remedial alternatives. Other pollution
minimization devices must be used if appropriate, including stabilizing disturbed areas
through land shaping, diverting runoff, planting quickly germinating and growing stands of
temporary vegetation, regulating channel velocity of water, lining drainage channels with
rock or vegetation, mulching, and control of acid-forming, and toxic-forming waste
materials.
ARM § 17.24.633. Surface drainage from a disturbed area must be treated by the best
technology currently available (BTCA). Treatment must continue until the area is
stabilized.
ARM 17.24.634. Requires disturbed drainages be restored to the approximate pre-disturbance
configuration, to the extent consistent with the selected remedial alternatives. Drainage
design must emphasize channel and floodplain dimensions that approximate the pre-mining
configuration and that will blend with the undisturbed drainage above and below the area
to be reclaimed. The average stream gradient must be maintained with a concave
longitudinal profile. This regulation provides specific requirements for designing the
reclaimed drainage to: (1) approximate an appropriate geomorphic habit or characteristic
pattern; (2) remain in dynamic equilibrium with the system without the use of artificial
structural controls; (3) improve unstable premining conditions; (4) provide for floods and
for the long-term stability of the landscape; and (5) establish a premining diversity of
aquatic habitats and riparian vegetation.
ARM § 17.24.638. Sediment control measures must be implemented during operations.
ARM § 17.24.639. Sets forth requirements for construction and maintenance of sedimentation
ponds.
ARM § 17.24.640. Discharges from sedimentation ponds, permanent and temporary
impoundments, must be controlled to reduce erosion and enlargement of stream channels, and
to minimize disturbance of the hydrologic balance.
ARM § 17.24.641. Practices to prevent drainage from acid or toxic forming spoil material
into ground and surface water will be employed.
ARM §§ 17.24.643 through 17.24.646. Provisions for groundwater protection, groundwater
recharge protection, and groundwater and surface water monitoring.
ARM §§ 17.24.701 and 702. Requirements for redistributing and stockpiling of soil for
reclamation. Also, outline practices to prevent compaction, slippage, erosion, and
deterioration of biological properties of soil will be employed.
-------
ARM § 17.24.703. When using materials other than, or along with, soil for final surfacing
in reclamation, the operator must demonstrate that the material (1) is at least as capable
as the soil of supporting the approved vegetation and subseguent land use, and (2) the
medium must be the best available in the area to support vegetation. Such substitutes must
be used in a manner consistent with the reguirements for redistribution of soil in ARM §
17.24.701 and 702.
ARM § 17.24.711. Reguires that a diverse, effective and permanent vegetative cover of the
same seasonal variety and utility as the vegetation native to the area of land to be
affected must be established. This provision would not be relevant and appropriate in
certain instances, for example, where there is dedicated development.
ARM § 17.24.713. Seeding and planting of disturbed areas must be conducted during the
first appropriate period for favorable planting after final seedbed preparation but may
not be more than 90 days after soil has been replaced.
ARM § 17.24.714. Mulch or cover crop or both must be used until adeguate permanent cover
can be established.
ARM § 17.24.716. Establishes method of revegetation.
ARM § 17.24.717. Relates to the planting of trees and other woody species if necessary, as
provided in § 82-4-233, MCA, to establish a diverse, effective, and permanent vegetative
cover of the same seasonal variety native to the affected area and capable of self-
regeneration and plant succession at least egual to the natural vegetation of the area,
except that introduced species may be used in the revegetation process where desireable
and necessary to achieve the approved land use plan.
ARM § 17.24.718. Reguires soil amendments, irrigation, management, fencing, or other
measures, if necessary to establish a diverse and permanent vegetative cover.
ARM § 17.24.721. Specifies that rills or gullies in reclaimed areas must be filled, graded
or otherwise stabilized and the area reseeded or replanted if the rills and gullies are
disrupting the reestablishment of the vegetative cover or causing or contributing to a
violation of water guality standards for a receiving stream.
ARM § 17.24.723. States that operators shall conduct approved periodic measurements of
vegetation, soils, water, and wildlife during the period of liability.
ARM 17.24.724. Specifies that revegetation success must be measured against approved
unmined reference areas or by comparison with technical standards from historic data. More
than one reference area or historic record must be established for vegetation types with
significant variation due to a number of factors. Reguired management for these reference
areas is set forth.
ARM § 17.24.726. Reguires standard and consistent field and laboratory methods to obtain
vegetation production, cover, diversity, density and utility data, and sets out the
reguired methods for measuring and documenting productivity.
ARM § 17.24.728. Sets performance standards for native species and introduced species in
revegetated areas.
ARM §§ 17.24.730 and 17.24.731. Provide that the revegetated area must furnish palatable
forage in comparable guantity and guality during the same grazing period as the reference
area or as compared to a technical standard derived from historic records. If toxicity to
plants or animals on the revegetated area or the reference area is suspected due to the
effects of the disturbance, comparative chemical analyses may be reguired.
ARM § 17.24.733. Provides performance standards for composition and stocking of trees,
shrubs and half-shrubs on the revegetated area and for measurement of revegetation
-------
success.
ARM § 17.24.751. Measures to protect and enhance fish and wildlife habitat will be
employed.
ARM § 17.24.824. If land use is to be other than grazing land or fish and wildlife
habitat, areas of land affected by mining must be restored in a timely manner to higher or
better uses achievable under criteria and procedures set forth.
5.5 Air Requirements
Remedial activities will comply with the following reguirements to ensure that existing
air guality will not be adversely affected by a Tenmile Creek Mining Area Site remedial
action.
ARM § 17.8.220 (applicable). Settled particulate matter shall not exceed a 30 day average
of 10 grams per sguare meter.
ARM § 17.8.222 (applicable). The concentration of lead in ambient air shall not exceed a
90 day average of 1.5 micrograms per cubic meter of air.
ARM § 17.8.223 (applicable). The concentration of PM-10 in ambient air shall not exceed a
24 hour average of 150 micrograms per cubic meter of air and an annual average of 50
micrograms per cubic meter of air.
ARM § 17.8.308 (applicable). Airborne particulate matter. There shall be no production,
handling, transportation, or storage of any material, use of any street, road, or parking
lot, or operation of a construction site or demolition project unless reasonable
precautions are taken to control emissions of airborne particles. Emissions shall not
exhibit an opacity exceeding 20% or greater averaged over 6 consecutive minutes.
ARM § 17.8.304(2) (applicable) . Visible Air Contaminants. Emissions into the outdoor
atmosphere shall not exhibit an opacity of 20% or greater averaged over 6 consecutive
minutes.
ARM § 17.24.761(2) (a) .(e) .(h) .(n) . and (k) (applicable) . Fugitive dust control measures
such as 1) watering, stabilization, or paving of roads, 2) vehicle speed restrictions, 3)
stabilization of surface areas adjoining roads, 4) restriction of travel on other than
authorized roads, 5) enclosing, covering, watering, or otherwise treating loaded haul
truck, 6) minimizing area of disturbed land, and 7) revegetation, must be planned and
implemented, if any such measure or measures are appropriate for this remedial action.
5.6 Noxious Weeds
Noxious Weeds, MCA § 7-22-2101(8) (a) and ARM § 4.5.201, et seg. MCA § 7-22-2101(8) (a)
defines "noxious weeds" as any exotic plant species established or that may be introduced
in the state which may render land unfit for agriculture, forestry, livestock, wildlife,
or other beneficial uses or that may harm native plant communities and that is designated:
(I) as a statewide noxious weed by rule of the department; or (ii) as a district noxious
weed by a board, following public notice of intent and a public hearing. Designated
noxious weeds are listed in ARM § 4.5.201 through 4.5.204 and must be managed consistent
with weed management criteria developed under MCA § 7-22-2109(2)(b).
6.0 TO BE CONSIDERED (TBC) DOCUMENTS
A list of TBC documents is included in the Preamble to the NCP, 55 Fed. Reg. 8765 (March
8, 1990). Those documents, plus any additional similar or related documents issued since
that time, were considered by EPA and MDEQ during the conduct of the remedial
investigation (RI)/feasibility study (FS) , and will be further considered during remedy
selection and during remedy implementation.
-------
7.0 OTHER LAWS (NON-EXCLUSIVE LIST)
CERCLA defines as ARARs only federal environmental and state environmental and siting
laws. Remedial design, implementation, and operation and maintenance must nevertheless
comply with all other applicable laws, both state and federal, if the remediation work is
done by parties other than the federal government or its contractors.
The following "other laws" are included here to provide a reminder of other legally
applicable reguirements for actions being conducted at the Upper Tenmile Creek Mining Area
Site. They are not intended to be an exhaustive list of such legal reguirements, but are
included because they set out related concerns that must be addressed and, in some cases,
may reguire some advance planning. They are not included as ARARs because they are not
"environmental or facility siting laws." As applicable laws other than ARARs, they are not
subject to ARAR waiver provisions.
Section 121(e) of CERCLA exempts remedial or remedial actions conducted entirely on- site
from federal, state, or local permits. This exemption is not limited to environmental or
facility siting laws, but applies to other permit reguirements as well.
7.1 Other Federal Laws
Occupational Safely and Health Regulations. The federal Occupational Safety and Health Act
regulations found at 29 CFR § 1910 are applicable to worker protection during conduct of
RI/FS or remedial activities.
7.2 Other State Laws
Groundwater Act. MCA § 85-2-505, precludes the wasting of groundwater. Any well producing
waters that contaminate other waters must be plugged or capped, and wells must be
constructed and maintained so as to prevent waste, contamination, or pollution of
groundwater.
Public Water Supply Regulations. If remedial action at the site reguires any
reconstruction or modification of any public water supply line or sewer line, the
construction standards specified in ARM § 17.38.101(4) must be observed.
Groundwater Act. MCA § 85-2-516 states that within 60 days after any well is completed a
well log report must be filed by the driller with the DNRC and the appropriate county
clerk and recorder.
Water Rights. MCA § 85-2-101 declares that all waters within the state are the state= s
property, and may be appropriated for beneficial uses. The wise use of water resources is
encouraged for the maximum benefit to the people and with minimum degradation of natural
aguatic ecosystems.
Parts 3 and 4 of Title 85, MCA, set out reguirements for obtaining water rights and
appropriating and utilizing water. All reguirements of these parts are laws which must be
complied with in any action using or affecting waters of the state. Some of the specific
reguirements are set forth below.
MCA § 85-2-301 provides that a person may only appropriate water for a beneficial use.
MCA § 85-2-302 specifies that a person may not appropriate water or commence construction
of diversion, impoundment, withdrawal or distribution works therefor except by applying
for and receiving a permit from the Montana Department of Natural Resources and
Conservation. While the permit itself may not be reguired under federal law, appropriate
notification and submission of an application should be performed and a permit should be
applied for in order to establish a priority date in the prior appropriation system.
MCA § 85-2-306 specifies the conditions on which groundwater may be appropriated, and, at
-------
a minimum, requires notice of completion and appropriation within 60 days of well
completion.
MCA § 85-2-311 specifies the criteria which must be met in order to appropriate water and
includes requirements that:
1. there are unappropriated waters in the source of supply;
2. the proposed use of water is a beneficial use; and
3. the proposed use will not interfere unreasonably with other planned uses or
developments.
MCA § 85-2-402 specifies that an appropriator may not chanqe an appropriated riqht except
as provided in this section with the approval of the DNRC.
MCA § 85-2-412 provides that where a person has diverted all of the water of a stream by
virtue of prior appropriation and there is a surplus of water, over and above what is
actually and necessarily used, such surplus must be returned to the stream.
Occupational Health Act. MCA § 50-70-101. et seq. ARM § 17.74.101 addresses occupational
noise. In accordance with this section, no worker shall be exposed to noise levels in
excess of the levels specified in this requlation. This requlation is applicable only to
limited cateqories of workers and for most workers the similar federal standard in 29 CFR
§ 1910.95 applies.
ARM § 17.74.102 addresses occupational air contaminants. The purpose of this rule is to
establish maximum threshold limit values for air contaminants under which it is believed
that nearly all workers may be repeatedly exposed day after day without adverse health
effects. In accordance with this rule, no worker shall be exposed to air contaminant
levels in excess of the threshold limit values listed in the requlation.
This requlation is applicable only to limited cateqories of workers and for most workers
the similar federal standard in 29 CFR § 1910.1000 applies.
Montana Safely Act. MCA §§ 50-71-201, 202 and 203 state that every employer must provide
and maintain a safe place of employment, provide and require use of safety devices and
safequards, and ensure that operations and processes are reasonably adequate to render the
place of employment safe. The employer must also do every other thinq reasonably necessary
to protect the life and safety of its employees. Employees are prohibited from refusinq to
use or interferinq with the use of safety devices.
Employee and Community Hazardous Chemical Information Act. MCA §§ 50-78-201, 202, and 204
state that each employer must post notice of employee riqhts, maintain at the work place
a list of chemical names of each chemical in the work place, and indicate the work area
where the chemical is stored or used. Employees must be informed of the chemicals at the
work place and trained in the proper handlinq of the chemicals.
-------
Appendix B
Mine Site Scoring and Capital Costs for
Selected Remedy
-------
Appendix B
Mine Site Scoring and Capital Costs for Selected Remedy
Contents
Table
Mine Site Scoring Summary B-l
Capital Cost Tables for Selected Remedy by Subarea:
Waste Rock and Tailings Excavation with Disposal in Luttrell Repository
Upper Tenmile Creek/ Monitor Creek B-2
Banner Creek/ Ruby Creek B-3
Tenmile Creek Near Rimini B-4
Beaver Creek B-5
Minnehaha Creek B-6
Treatment at Individual Mine Adits
Upper Tenmile Creek/ Monitor Creek (Biological Treatment) B-7
Banner Creek/ Ruby Creek (Biological Treatment) B-8
Tenmile Creek Near Rimini (Biological Treatment minus three Rimini adits) .... B-9
Tenmile Creek Near Rimini (Reverse Osmosis with Sludge Drying Beds for three
Rimini adits) B-10
Beaver Creek B-ll
Minnehaha Creek B-12
Bear Gulch/Walker Creek B-13
Surface Water: Additional Water Storage in Chessman Reservoir ,
Residential and Recreational Yard Soil Excavation with Disposal in Luttrell Repository
Tenmile Creek Near Rimini B-15
Tenmile Mainstem B-16
Contaminated Roadway Materials: Excavation with Disposal at Luttrell Repository .... B-17
-------
Table B-1
Mine Site Scoring Summary
Site Name
Armstrong
Avon Mill
Ballon
Banner Creek Placer
Banner Creek Tailings
Beatrice
Beatrice East
Beatrice South
Blue Boy
Carlson Mine
Chessman
Colorado
Copper Dyke
Eureka
Evergreen Reclamation
Free Speech #1
Gold Coin
Gold Coin Trench
Gold Crown
Green Grove
Isabella Placer
Jill
Jimmy
JJ Hill Claims
Jolly Roger
Justice
Kelly Mill
Lady Hennessy
Little Lily
Lode
Lulu
May Day
May Lillie
Monitor Creek Placer
Site
Number
MS070
MS110
MS072
MS330
MS023
MS071
MS308
MS062
MS067
MS118
MS320
MS306
MS003
MS112
MS 136
MS046
MS006
MS119
MS040
MS332
MS333
MS120
MS008
MS058
MS009
MS068
MS073
MS033
MS084
MS041
MS012
MS121
MS014
MS 126
Subarea
MC
TR
TR
RC
RC
MC
MC
MC
MC
UT
BC
BC
RC
TR
TR
TR
UT
UT
BG
TR
UT
UT
RC
BC
RC
MC
TM
UT
TR
BG
RC
UT
RC
UT
Direct
Contact
Total
14
1
2
4
4
0
0
63
0
1
2
19
34
7
25
27
1
1
11
2
4
1
36
0
39
3
2
2
8
4
24
3
55
4
Surface
Water
Total
5
4
1
0
10
0
0
22
59
13
88
63
22
20
38
43
10
8
5
29
0
9
12
12
18
1
0
35
1
2
15
50
35
0
Groundwater
Total
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
0
0
0
0
0
0
1
0
2
0
0
0
0
0
1
0
3
0
Total
Score
19
5
3
5
15
1
1
86
59
14
91
83
56
28
63
70
10
9
15
31
5
9
49
12
59
4
2
38
10
5
41
53
93
5
Site
Category
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
Notes:
Score >=750, Category E
500 - 750, Category D
250 - 500, Category C
100-250, Category B
<= 100, Category A
App BTableB-1.xls
Page 1 of 5
-------
Table B-1
Mine Site Scoring Summary
Site Name
NENWS16
NENWS23
NESWS34
New Castle
North Pacific
NWNES16
NW SW S3
Peerless Jenny
Peerless King
Red Mountain
Red Water
SESES13
Silver Cresent
Susie
(Unknown) Beaver Creek
Unnamed
Upper Tenmile Shaft
Virginia
1900
Alice Lode
Atlas
Bear Gulch
Black Hawk
Cappolis
Catherine
Close Shave
Dan Kim
General
Gold Hill
Green Tea North
H. Davis
H. Grattan
Little Sampson
Louise Lode
Site Number
MS015
MS 122
MS061
MS016
MS094
MS027
MS048
MS035
MS018
MS114
MS115
MS 132
MS021
MS116
MS053
MS042
MS129
MS337
MS117
MS075
MS334
MS043
MS002
MS063
MS305
MS079
MS004
MS099
MS007
MS313
MS315
MS082
MS 101
MS328
Subarea
RC
UT
BC
RC
TR
RC
BC
RC
RC
TR
TR
UT
RC
TR
BC
BG
UT
UT
UT
TR
RC
BG
RC
TR
TR
TR
RC
TR
RC
RC
TR
TR
TR
BC
Direct
Contact
Total
21
1
6
29
7
22
29
1
2
1
7
4
30
1
34
17
1
0
3
121
0
11
94
134
121
70
58
100
39
37
108
59
84
27
Surface
Water
Total
14
17
17
19
1
14
19
20
12
3
20
0
19
3
22
78
15
0
161
22
176
233
140
36
76
85
183
104
95
101
128
80
119
77
Groundwater
Total
1
0
0
0
0
1
2
0
0
0
1
1
0
0
0
1
0
0
14
1
0
1
1
1
4
3
3
3
2
1
5
3
2
2
Total
Score
36
18
23
48
8
37
50
21
14
4
28
5
48
4
56
95
16
0
178
143
176
245
235
172
201
159
245
207
136
139
242
142
206
106
Site
Category
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
Notes:
Score >=750, Category E
500 - 750, Category D
250 - 500, Category C
100-250, Category B
<= 100, Category A
App BTableB-1.xls
Page 2 of 5
-------
Table B-1
Mine Site Scoring Summary
Site Name
Lower Tenmile Mill
Lucky Linda
NESES4
No Name
NW NW S34
Paupers Dream
Perseverance
Porphry Dike
Queensbury North
Red Mountain Tunnel
Rob Roy
SESES3
Alley Fraction
American Flag
Beatrice North
Belle
Castle Rock
Comstock
Coon Creek Mill
Daniel Stanton
Evergreen #2
Fairview #23
Fairview #25
Garfield
Hamlet
Horsefly Adit
Jackson Lode
Knight of Gwinne
Lady Washington
Last Resort 2
Lexington
Lexington East
Little Giant
Little Sampson East
Site Number
MS074
MS011
MS056
MS 102
MS086
MS 128
MS036
MS123
MS314
MS 104
MS087
MS059
MS316
MS044
MS309
MS076
MS077
MS339
MS 124
MS080
MS089
MS 135
MS081
MS005
MS 100
MS055
MS307
MS083
MS304
MS327
MS092
MS301
MS331
MS329
Subarea
TM
RC
BC
TR
TR
UT
RC
UT
RC
BC
TR
BC
TR
TR
MC
TR
TR
UT
UT
TR
TR
TR
TR
RC
TR
BC
BC
TR
TR
TR
TR
TR
BC
TR
Direct
Contact
Total
2
55
59
14
91
1
4
1
31
24
104
37
73
280
54
103
103
1
1
125
127
75
125
19
111
25
40
23
121
154
202
78
104
202
Surface
Water
Total
228
181
95
156
24
151
210
169
127
152
65
144
303
139
223
238
288
381
344
258
271
179
287
289
235
334
213
381
345
128
232
176
195
242
Groundwater
Total
0
3
2
0
5
0
0
0
1
0
3
1
2
2
6
2
4
0
0
3
5
3
5
3
6
2
0
4
4
6
1
3
4
11
Total
Score
230
239
157
171
120
152
215
170
159
177
172
183
378
420
283
343
395
382
345
385
404
258
416
311
353
361
254
408
470
287
435
257
303
454
Site
Category
B
B
B
B
B
B
B
B
B
B
B
B
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
Notes:
Score >=750, Category E
500 - 750, Category D
250 - 500, Category C
100-250, Category B
<= 100, Category A
App BTableB-1.xls
Page 3 of 5
-------
Table B-1
Mine Site Scoring Summary
Site Name
Mary Aloys
Monitor Creek Tailings
NW NW S9
Paupers Dream Camp
Peter
Pocahontas
Queensbury
Red Mountain East
Ruby Fraction
SESES10
Silver Wave
Teal Lake
Treasury #1
Tunnel Lode
W. Coyne
WA Alley
Wolftone
Wood row Wilson
Bunker Mile
Clontart/Carp
Conflict
Former Stanton
Green Tree
Helena
Monitor Creek Mill
Pilgrim
Silver Chief
South Pacific
SW SE S5
Bunker Hill
Dalney
Evergreen
Evergreen #3
Hidden Treasure
Site Number
MS013
MS 130
MS028
MS310
MS029
MS066
MS037
MS303
MS019
MS051
MS317
MS 108
MS022
MS326
MS318
MS031
MS 109
MS038
MS319
MS078
MS111
MS323
MS025
MS026
MS 125
MS057
MS322
MS052
MS107
MS098
MS045
MS324
MS 133
MS321
Subarea
RC
UT
RC
UT
RC
MC
RC
TR
RC
BC
TR
TR
RC
TR
TR
RC
TR
RC
TR
TR
TR
TR
RC
RC
UT
BC
TR
TR
TR
TR
BC
TR
TR
TR
Direct
Contact
Total
79
5
44
1
6
70
11
106
39
34
73
289
62
122
78
24
181
14
142
359
90
158
0
162
25
85
24
229
210
477
136
153
104
415
Surface
Water
Total
230
418
386
264
425
272
340
243
407
274
268
208
205
201
305
246
274
256
380
233
608
495
551
462
683
466
586
315
337
1062
1899
938
847
694
Groundwater
Total
4
0
2
0
0
6
2
4
4
0
3
3
4
6
3
0
1
1
4
26
10
6
0
3
6
6
2
1
6
25
17
8
3
21
Total
Score
313
424
432
266
431
349
354
353
450
308
343
499
271
329
387
271
456
271
526
618
708
659
552
627
714
557
612
546
552
1564
2050
1100
954
1130
Site
Category
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
D
D
D
D
D
D
D
D
D
D
D
E
E
E
E
E
Notes:
Score >=750, Category E
500 - 750, Category D
250 - 500, Category C
100-250, Category B
<= 100, Category A
App BTableB-1.xls
Page 4 of 5
-------
Table B-1
Mine Site Scoring Summary
Site Name
Johny #1
Johny #2
Jumbo
L. &H.
Lee Mountain
Lucky Joe
Micawber
Mineral Deposit
Monte Cristo
National Extension
Omaha South
S.P. Bassett
Upper Valley Forge
WA Alley 2
Site Number
MS064
MS 134
MS090
MS335
MS091
MS065
MS093
MS032
MS034
MS060
MS338
MS 105
MS097
MS311
Subarea
TR
TR
TR
RC
TR
MC
TR
TR
RC
BC
RC
TR
TR
TR
Direct
Contact
Total
180
129
109
87
88
32
231
465
144
450
74
144
286
297
Surface
Water
Total
609
699
978
982
703
915
509
1478
2199
3250
1157
863
1747
517
Groundwater
Total
5
6
7
5
8
3
14
32
11
50
12
5
32
10
Total
Score
794
834
1093
1074
800
950
754
1975
2354
3750
1243
1012
2065
824
Site
Category
E
E
E
E
E
E
E
E
E
E
E
E
E
E
Notes:
Score >=750, Category E
500 - 750, Category D
250 - 500, Category C
100-250, Category B
<= 100, Category A
App BTableB-1.xls
Page 5 of 5
-------
Table B-2
Estimated Capital Cost for Selected Remedy
Waste Rock and Tailings
Alternative WR4: Excavation with Disposal in Luttrell Repository
Subarea: Upper Tenmile Creek/Monitor Creek
Item
Access road
Site preparation and storm water control
Excavate mine waste
Transport mine waste
Spread and compact mine waste
Luttrell Repository disposal
Backfill and close mine openings
6" coversoil on excavated areas
Organic amendment
Fertilize and seed
Mulch
Erosion control mat
Fence reclaimed areas
Reclaim Access roads
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit |
if
acre
cy
cy-mile
cy
cy
each
cy
acre
acre
acre
sy
If
If
8%
20%
8%
15%
10%
Is
Unit Cost
$ 3.20
$ 13,900.00
$ 1.98
$ 0.60
$ 3.14
$ 5.00
$ 5,000.00
$ 7.90
$ 300.00
$ 1,137.00
$ 980.00
$ 1.11
$ 2.18
$ 3.20
$ 400.00
Category C
Quantity |
6,523
0.71
110,414
154,623
110,414
110,414
4
570
0.71
0.71
0.56
705
781
6,523
4
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Sites
Cost
20,874
9,810
218,620
92,774
346,700
552,070
20,000
4,499
500
802
549
783
1,703
20,874
1,290,558
103,245
258,112
1,651,914
132,153
247,787
165,191
545,131
1,600
2,198,645
Category D Sites Categor
Quantity | Cost Quantity |
326 $ 1,043 0
1.0 $ 13,854 0
16,080 $ 31,838 0
14,472 $ 8,683 0
16,080 $ 50,491 0
16,080 $ 80,400 0
1 $ 5,000 0
804 $ 6,354 0
1.0 $ 500 0
1.0 $ 1,133 0
0.80 $ 784 0
952 $ 1,057 0
913 $ 1,991 0
326 $ 1,043 0
$ 204,173
$ 16,334
$ 40,835
$ 261,342
$ 20,907
$ 39,201
$ 26,134
$ 86,243
1 $ 400 0
$ 347,985
y E Sites
Cost Source of Cost Data
$ - ECHOS 2000; 17-03-0101
$ - ECHOS 2000;17-01-0105, 33-05-0802
$ - Means 2000; 02315-400-0260,
$ - EPA Cost Estimate
$ - ECHOS 2000; 17-03-0422
$ - EPA Cost Estimate
$ - Engineering Estimate
$ - ECHOS 2000; 17-03-0423
$ - Engineering Estimate
$ - Means 2000; 02920-51 0-4500,
$ - Means 2000; 0291 0-500-0350
$ - Means 2000; 02370-550-0010
$ - ECHOS 2000; 18-04-0110
$ - ECHOS 2000; 17-03-0101
$
$ - Engineering Estimate
$ - 15% Scope, 5% Bid
$
$ - EPA Cost Guidance
$ - EPA Cost Guidance
$ - EPA Cost Guidance
$
0020 (loading)
02920-510-7000
$ - 4 hours per property @ $100/hr legal fees
$
Cost Tables B-2 to B-17.xlsWR4 UT
-------
Table B-3
Estimated Capital Cost for Selected Remedy
Waste Rock and Tailings
Alternative WR4: Excavation with Disposal in Luttrell Repository
Subarea: Banner Creek/Ruby Creek
Item
Access road
Site preparation and storm water control
Excavate mine waste
Transport mine waste
Spread and compact mine waste
Luttrell Repository disposal
Backfill and close mine openings
6" coversoil on excavated areas
Organic amendment
Fertilize and seed
Mulch
Erosion control mat
Fence reclaimed areas
Reclaim Access roads
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit
if
acre
cy
cy-mile
cy
cy
each
cy
acre
acre
acre
sy
If
If
8%
20%
8%
15%
10%
Is
Unit Cost
$ 3.20
$ 13,900.00
$ 1.98
$ 0.60
$ 3.14
$ 5.00
$ 5,000.00
$ 7.90
$ 300.00
$ 1,137.00
$ 980.00
$ 1.11
$ 2.18
$ 3.20
$ 400.00
Category C
Quantity
22,466
2.5
12,005
66,248
12,005
12,005
9
2,007
2.5
2.5
2.0
2,407
1,397
22,466
9
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Sites
Cost
71,891
35,574
23,770
39,749
37,696
60,025
45,000
15,857
746
2,828
1,950
2,672
3,045
71,891
41 1 ,693
32,935
82,339
526,967
42,157
79,045
52,697
1 73,899
3,600
704,467
Category D Sites
Quantity
218 $
0.24 $
2,525 $
14,754 $
2,525 $
2,252 $
2 $
193 $
0.24 $
0.24 $
0.19 $
236 $
488 $
218 $
$
$
$
$
$
$
$
$
2 $
$
Cost
698
3,319
5,000
8,852
7,929
12,625
10,000
1,522
500
500
500
500
1,064
698
53,705
4,296
10,741
68,743
5,499
10,311
6,874
22,685
800
92,228
Category E Sites
Quantity
218
0.24
8,264
14,754
8,264
8,264
3
193
0.24
0.24
0.19
236
488
218
3
$
Cost
$ 698
$ 3,319
$ 16,363
$ 8,852
$ 25,949
$ 41,320
$ 15,000
$ 1 ,522
$ 500
$ 500
$ 500
$ 500
$ 1 ,064
$ 698
$ 116,784
$ 9,343
$ 23,357
$ 149,484
$ 1 1 ,959
$ 22,423
$ 14,948
$ 49,330
$ 1 ,200
200,013
Source of Cost Data
ECHOS2000; 17-03-0101
ECHOS 2000;17-01-0105, 33-05-0802
Means 2000; 02315-400-0260,
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
ECHOS 2000; 17-03-0423
Engineering Estimate
Means 2000; 02920-510-4500,
Means 2000; 02910-500-0350
Means 2000; 02370-550-0010
ECHOS 2000; 18-04-0110
ECHOS 2000; 17-03-0101
Engineering Estimate
15% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
0020 (loading)
02920-510-7000
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17.xlsWR4 RC
-------
Table B-4
Estimated Capital Cost for Selected Remedy
Waste Rock and Tailings
Alternative WR4: Excavation with Disposal in Luttrell Repository
Subarea: Tenmile Creek Near Rimini
Item
Access road
Site preparation and storm water control
Excavate mine waste
Transport mine waste
Spread and compact mine waste
Luttrell Repository disposal
Backfill and close mine openings
6" coversoil on excavated areas
Organic amendment
Fertilize and seed
Mulch
Erosion control mat
Fence reclaimed areas
Reclaim Access roads
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit
if $
acre $
cy $
cy-mile $
cy $
cy $
each $
cy $
acre $
acre $
acre $
sy $
If $
If $
8%
20%
8%
15%
10%
Is $
Unit Cost
3.20
13,900.00
1.98
0.60
3.14
5.00
5,000.00
7.90
300.00
1,137.00
980.00
1.11
2.18
3.20
400.00
Category C Sites
Quanity
21,641
2.6
12,598
90,500
12,598
12,598
21
2,077
2.6
2.6
2.1
2,487
1,419
21,641
21
Cost
$ 69,251
$ 35,775
$ 24,943
$ 54,300
$ 39,556
$ 62,988
$ 105,000
$ 16,408
$ 772
$ 2,926
$ 2,019
$ 2,760
$ 3,094
$ 69,251
$ 489,044
$ 39,124
$ 97,809
$ 625,976
$ 50,078
$ 93,896
$ 62,598
$ 206,572
$ 8,400
$ 840,948
Category D Sites
Quanity
4,611 $
1.3 $
6,361 $
51,319 $
6,361 $
6,361 $
7 $
1 ,068 $
1.3 $
1.3 $
1.1 $
1,278 $
1,041 $
4,611 $
$
$
$
$
$
$
$
$
7 $
$
Cost
14,755
18,404
12,595
30,791
19,974
31,805
35,000
8,441
500
1,505
1,039
1,418
2,269
14,755
193,251
15,460
38,650
247,361
19,789
37,104
24,736
81,629
2,800
331 ,791
Category E Sites
Quanity
16,564
11
61,173
511,420
61,173
61,173
13
8,946
11
11
9
10,723
2,860
16,564
13
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Cost
53,005
154,089
121,123
308,852
192,083
305,865
65,000
70,674
3,326
12,604
8,693
1 1 ,903
6,234
53,005
1 ,364,455
109,156
272,891
1,746,502
139,720
261,975
174,650
576,346
5,200
2,328,048
Source of Cost Data
ECHOS2000; 17-03-0101
ECHOS 2000;17-01-0105, 33-05-0802
Means 2000; 02315-400-0260,
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
ECHOS 2000; 17-03-0423
Engineering Estimate
Means 2000; 02920-510-4500,
Means 2000; 02910-500-0350
Means 2000; 02370-550-0010
ECHOS 2000; 18-04-0110
ECHOS 2000; 17-03-0101
Engineering Estimate
15% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
0020 (loading)
02920-510-7000
4 hours per property @ $100/hr legal fees
Cost Tables B-12to B-17.xlsWR4 TR
-------
Table B-5
Estimated Capital Cost for Selected Remedy
Waste Rock and Tailings
Alternative WR4: Excavation with Disposal in Luttrell Repository
Subarea: Beaver Creek
Item
Access road
Site preparation and storm water control
Excavate mine waste
Transport mine waste
Spread and compact mine waste
Luttrell Repository disposal
Backfill and close mine openings
6" coversoil on excavated areas
Organic amendment
Fertilize and seed
Mulch
Erosion control mat
Fence reclaimed areas
Reclaim Access roads
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit
if $
acre $
cy $
cy-mile $
cy $
cy $
each $
cy $
acre $
acre $
acre $
sy $
If $
If $
8%
20%
8%
15%
10%
Is $
Unit Cost
3.20
13,900.00
1.98
0.60
3.14
5.00
5,000.00
7.90
300.00
1,137.00
980.00
1.11
2.18
3.20
400.00
Category C Sites
Quanity
19,547
0.47
1,884
16,170
1,884
1,884
4
376
0.47
0.47
0.37
464
650
19,547
4
Cost
$ 62,550
$ 6,477
$ 3,730
$ 9,702
$ 5,916
$ 9,420
$ 20,000
$ 2,971
$ 500
$ 530
$ 500
$ 516
$ 1,417
$ 62,550
$ 186,778
$ 14,942
$ 37,356
$ 239,076
$ 19,126
$ 35,861
$ 23,908
$ 78,895
$ 1 ,600
$ 319,571
Category D Sites
Quanity
1 ,953 $
0.22 $
2,132 $
15,350 $
2,132 $
2,132 $
1 $
178 $
0.22 $
0.22 $
0.18 $
195 $
472 $
1 ,953 $
$
$
$
$
$
$
$
$
1 $
$
Cost
6,250
3,062
4,221
9,210
6,694
10,660
5,000
1,405
500
500
500
500
1,029
6,250
55,781
4,462
11,156
71,400
5,712
10,710
7,140
23,562
400
95,361
Category E Sites
Quanity
16,053
2.2
14,690
171,566
14,690
14,690
2
1,743
2.2
2.2
1.7
2,082
1,307
16,053
2
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Cost
51,370
30,027
29,086
102,940
46,127
73,450
10,000
13,772
648
2,456
1,695
2,311
2,849
51,370
418,101
33,448
83,620
535,169
42,814
80,275
53,517
176,606
800
712,575
Source of Cost Data
ECHOS2000; 17-03-0101
ECHOS 2000;17-01-0105, 33-05-0802
Means 2000; 02315-400-0260,
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
ECHOS 2000; 17-03-0423
Engineering Estimate
Means 2000; 02920-510-4500,
Means 2000; 02910-500-0350
Means 2000; 02370-550-0010
ECHOS 2000; 18-04-0110
ECHOS 2000; 17-03-0101
Engineering Estimate
15% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
0020 (loading)
02920-510-7000
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17 .xlsWR4 BC
-------
Table B-6
Estimated Capital Cost for Selected Remedy
Waste Rock and Tailings
Alternative WR4: Excavation with Disposal in Luttrell Repository
Subarea: Minnehaha Creek
Item
Access road
Site preparation and storm water control
Excavate mine waste
Transport mine waste
Spread and compact mine waste
Luttrell Repository disposal
Backfill and close mine openings
6" coversoil on excavated areas
Organic amendment
Fertilize and seed
Mulch
Erosion control mat
Fence reclaimed areas
Reclaim Access roads
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit
if
acre
cy
cy-mile
cy
cy
each
cy
acre
acre
acre
sy
If
If
8%
20%
8%
15%
10%
Is
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Unit Cost
3.20
13,900.00
1.98
0.60
3.14
5.00
5,000.00
7.90
300.00
1,137.00
980.00
1.11
2.18
3.20
400.00
Category C Sites Catego
Quanity Cost Quanity
2,688 $ 8,602 0
0.32 $ 4,439 0
872 $ 1,727 0
9,072 $ 5,443 0
872 $ 2,738 0
872 $ 4,360 0
2 $ 10,000 0
258 $ 2,036 0
0.32 $ 500 0
0.32 $ 500 0
0.26 $ 500 0
287 $ 500 0
552 $ 1,203 0
2,688 $ 8,602 0
$ 51,149
$ 4,092
$ 10,230
$ 65,471
$ 5,238
$ 9,821
$ 6,547
2 $ 800 0
ry D Sites Category E Sites
Cost Quanity Cost
$ - 750 $ 2,400
$ - 0.23 $ 3,171
$ - 1,324 $ 2,622
$ - 12,313 $ 7,388
$ - 1,324 $ 4,157
$ - 1,324 $ 6,620
$ - 1 $ 5,000
$ - 184 $ 1,454
$ - 0.23 $ 500
$ - 0.23 $ 500
$ - 0.18 $ 500
$ - 233 $ 500
$ - 479 $ 1,044
$ - 750 $ 2,400
$ - $ 38,255
$ - $ 3,060
$ - $ 7,651
$ - $ 48,967
$ - $ 3,917
$ - $ 7,345
$ - $ 4,897
$ 16,159
$ - 1 $ 400
Source of Cost Data
ECHOS2000; 17-03-0101
ECHOS 2000;17-01-0105, 3-05-0802
Means 2000; 02315-400-0260,
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
ECHOS 2000; 17-03-0423
Engineering Estimate
Means 2000; 02920-510-4500,
Means 2000; 02910-500-0350
Means 2000; 02370-550-0010
ECHOS 2000; 18-04-0110
ECHOS 2000; 17-03-0101
Engineering Estimate
15% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
020 (loading)
2920-510-7000
4 hours per property @ $100/hr legal fees
$ 87,877 $ - $ 65,526
Cost Tables B-2 to B-17 .xlsWR4 MC
-------
Table B-7
Estimated Capital Cost for Selected Remedy
Acid Mine Drainage
Alternative ADB4: Biological Treatment at Individual Mine Adits
Subarea: Upper Tenmile Creek/Monitor Creek
Item
Access road to treatment site
Clear and grub treatment site
Wetlands facility earthwork
Substrate
Discharge pipeline
Grass Ditching
Rough Grading
Fertilize and seed
Mulch
Site fencing
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Additional AMD Source Control
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit |
If $
acre $
ac $
ac $
If $
If $
Is $
acre $
acre $
If $
8%
30%
10%
Is
20%
15%
Is $
Unit Cost |
3.20
836.95
10,000.00
48,400.00
7.41
15.61
5,000.00
1,137.00
980.00
20.35
400.00
Quanity I
5,439
0.03
0.03
0.01
200
800
2
2
2
179
SUBTOTAL
SUBTOTAL
SUBTOTAL
2
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Cost |
17,405
500
500
676
1,482
12,488
10,000
2,274
1,960
3,636
50,920
4,074
15,276
70,270
7,027
500,000
14,054
10,541
531 ,662
800
602,692
Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
Engineering Estimate
Engineering Estimate
ECHOS2000; 19-02-0126;
ECHOS 2000; 33-05-0802;
Engineering Estimate
Means 2000; 02920-510-4500, 02920-510-7000
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering Estimate
EPA Cost Guidance
EPA Cost Guidance
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17 .xlsAD4B UT
-------
Table B-8
Estimated Capital Cost for Selected Remedy
Acid Mine Drainage
Alternative ADB4: Biological Treatment at Individual Mine Adits
Subarea: Banner Creek/Ruby Creek
Item
Access road to treatment site
Clear and grub treatment site
Wetlands facility earthwork
Substrate
Discharge pipeline
Grass Ditching
Rough Grading
Fertilize and seed
Mulch
Site fencing
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Additional AMD Source Control
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit |
If
acre
ac
ac
If
If
Is
acre
acre
If
8%
30%
8%
Is
15%
10%
Is
$
$
$
$
$
$
$
$
$
$
$
Unit Cost |
3.20
836.95
10,000.00
48,400.00
7.41
15.61
5,000.00
1,137.00
980.00
20.35
400.00
Quanity I
22,733
0.23
0.23
0.13
200
4,800
12
12
12
378
SUBTOTAL
SUBTOTAL
SUBTOTAL
12
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Cost |
72,746
500
2,293
6,166
1,482
74,928
60,000
13,644
1 1 ,760
7,692
251,211
20,079
75,363
346,671
27,734
2,000,000
52,001
34,667
2,114,402
4,800
2,465,873
Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
Engineering Estimate
Engineering Estimate
ECHOS 2000; 19-02-0126;
ECHOS 2000; 33-05-0802;
Engineering Estimate
Means 2000; 02920-510-4500, 02920-510-7000
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering Estimate
EPA Cost Guidance
EPA Cost Guidance
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17 .xlsAD4B RC
-------
Table B-9
Estimated Capital Cost for Selected Remedy
Acid Mine Drainage
Alternative AB: Biological Treatment at Adit (All except 3 Rimini adits)
Subarea: Tenmile Creek Near Rimini
Item
Access road to treatment site
Clear and grub treatment site
Wetlands facility earthwork
Substrate
Discharge pipeline
Grass Ditching
Rough Grading
Fertilize and seed
Mulch
Site fencing
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Additional AMD Source Control
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit |
If $
acre $
ac $
ac $
If $
If $
Is $
acre $
acre $
If $
8%
30%
6%
Is
12%
8%
Is $
Unit Cost |
3.20
836.95
10,000.00
48,400.00
7.41
15.61
5,000.00
1,137.00
980.00
20.35
400.00
Quanity I
14,070
2.1
2.1
1.2
200
6,000
15
15
15
991
SUBTOTAL
SUBTOTAL
SUBTOTAL
15
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Cost |
45,024
1,793
21,420
57,596
1,482
20,161
147,476
1 1 ,798
44,243
203,516
12,211
24,422
16,281
52,914
6,000
262,431
Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
Engineering Estimate
Engineering Estimate
ECHOS2000; 19-02-0126;
ECHOS 2000; 33-05-0802;
Engineering Estimate
Means 2000; 02920-510-4500, 02920-510-7000
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering Estimate
EPA Cost Guidance
EPA Cost Guidance
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17 .xlsAD4B TR
-------
Table B-10
Cost Estimate for Acid Mine Drainage
Alternative AD5B: Physical-Chemical Treatment
(3 Rimini Adits Only - Reverse Osmosis with Sludge Drying Beds)
Subarea: Tenmile Creek Near Rimini
Item
Access road to treatment site
Clear and grub treatment site
AMD collection piping
Lime Softening
RO facility
Treatment Component Installation
Sludge Drying Beds
Treatment Building
Electrical Supply
Discharge pipeline
Grass Ditching
Rough Grading
Fertilize and seed
Mulch
Site Fencing
Mobilization/Demobilization, Bonding, and
Insurance
Construction Contingencies
Project Management
Additional AMD Source Control
Remedial Design
Construction Management
Proprietary Controls for Mine Waste Areas
TOTAL CAPITAL COSTS
I Unit | Unit Cost
If $
acre $
If $
gpm $
gpm $
Is $
sy $
sf $
Is $
If $
If $
Is $
acre $
acre $
If $
8%
30%
6%
Is
12%
8%
Is $
3.20
836.95
7.41
1,428.57
3,000.00
23,249.99
10.00
25.00
20,000.00
7.41
15.61
5,000.00
1,137.00
980.00
20.35
400.00
Quanity
500
5
6,000
35
35
1
19,355
3,000
1
3,000
6,000
15
15
15
500
SUBTOTAL
SUBTOTAL
SUBTOTAL
3
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Cost
1,600
4,185
44,460
50,000
105,000
23,250
193,550
75,000
20,000
23,230
93,660
75,000
17,055
14,700
10,175
749,865
59,989
224,959
1,034,813
62,089
2,000,000
124,178
82,785
2,269,051
1,200
3,305,065
Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
ECHOS2000; 19-02-0126;
Vendor Estimate
Vendor Estimate
Engineering estimate (15% of component cost)
Engineering Estimate
ECHOS 2000; 18-02-032, Means 13128-700-2100
Engineering Estimate
ECHOS 2000; 19-02-0126;
ECHOS 2000; 33-05-0802
Engineering Estimate
Means 2000; 02920-510-4500,
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering Estimate
EPA Cost Guidance
EPA Cost Guidance
02920-510-7000
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17 .xlsADS TR
-------
Table B-11
Estimated Capital Cost for Selected Remedy
Acid Mine Drainage
Alternative AD4B: Biologicial Treatment at Individual Mine Adits
Subarea: Beaver Creek
Item Unit Unit C
Access road to treatment site If $
ost Quantity Cost
3.20 14,618 $ 46,778
Clear and grub treatment site acre $ 836.95 0.23 $ 500
Wetlands facility earthwork ac $ 10,000.00 0.23 $ 2,293
Substrate ac $ 48,400.00 0.13 $ 6,166
Discharge pipline If $
Grass Ditching If $
7.41 200 $ 1,482
15.61 800 $ 12,488
Rough Grading Is $ 5,000.00 2 $ 10,000
Fertilize and seed acre $ 1,137.00 2 $ 2,274
Mulch acre $ 980.00 2 $ 1,960
Site fencing If $
Mobilization/Demobilization, Bonding, and
Insurance 8%
Construction Contingencies 30%
Project Management 10%
Additional AMD Source Control Is
Remedial Design 20%
Construction Management 15%
20.35 378 $ 7,692
SUBTOTAL $ 91,633
$ 7,331
$ 27,490
SUBTOTAL $ 126,454
$ 12,645
$ 500,000
$ 25,291
$ 18,968
SUBTOTAL $ 556,904
Proprietary Controls for Mine Waste Areas Is $ 400.00 2 $ 800
TOTAL CAPITAL COSTS
$ 684,158
| Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
Engineering Estimate
Engineering Estimate
ECHOS 2000; 19-02-0126;
ECHOS 2000; 33-05-0802;
Engineering Estimate
Means 2000; 02920-510-4500, 02920-510-7000
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering estimate
EPA Cost Guidance
EPA Cost Guidance
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17.xlsAD4B BC
-------
TableB-12
Estimated Capital Cost for Selected Remedy
Acid Mine Drainage
Alternative AD4B: Biologicial Treatment at Individual Mine Adits
Subarea: Minnehaha Creek
Item Unit Unit C
Access roads If $
ost Quantity Cost
3.20 1,842 $ 5,894
Clear and grub treatment site acre $ 836.95 0.02 $ 500
Wetlands facility earthwork ac $ 10,000.00 0.02 $ 500
Substrate ac $ 48,400.00 0.009 $ 500
Discharge pipline If $
Grass Ditching If $
7.41 200 $ 1,482
15.61 2,000 $ 31,220
Rough Grading Is $ 5,000.00 5 $ 25,000
Fertilize and seed acre $ 1,137.00 5 $ 5,685
Mulch acre $ 980.00 5 $ 4,900
Site fencing If $
Mobilization/Demobilization, Bonding, and
Insurance 8%
Construction Contingencies 30%
Project Management 10%
Additional AMD Source Control Is
Remedial Design 20%
Construction Management 15%
20.35 159 $ 3,227
SUBTOTAL $ 78,908
$ 6,313
$ 23,672
SUBTOTAL $ 108,893
$ 10,889
$ 500,000
$ 21,779
$ 16,334
SUBTOTAL $ 549,002
Proprietary Controls for Mine Waste Areas Is $ 400.00 5 $ 2,000
TOTAL CAPITAL COSTS
$ 659,895
Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
Engineering Estimate
Engineering Estimate
ECHOS 2000; 19-02-0126;
ECHOS 2000; 33-05-0802;
Engineering Estimate
Means 2000; 02920-510-4500, 02920-510-7000
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering estimate
EPA Cost Guidance
EPA Cost Guidance
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17.xlsAD4B MC
-------
TableB-13
Estimated Capital Cost for Selected Remedy
Acid Mine Drainage
Alternative AD4B: Biologicial Treatment at Individual Mine Adits
Subarea: Bear Gulch/Walker Creek
Item Unit Unit C
Access road to treatment site If $
ost Quantity Cost
3.20 4,446 $ 14,227
Clear and grub treatment site acre $ 836.95 0.004 $ 500
Wetlands facility earthwork ac $ 10,000.00 0.004 $ 500
Substrate ac $ 48,400.00 0.002 $ 500
Discharge pipline If $
Grass Ditching If $
7.41 200 $ 1,482
15.61 400 $ 6,244
Rough Grading Is $ 5,000.00 1 $ 5,000
Fertilize and seed acre $ 1,137.00 1.0 $ 1,137
Mulch acre $ 980.00 1.0 $ 980
Site fencing If $
Mobilization/Demobilization, Bonding, and
Insurance 8%
Construction Contingencies 30%
Project Management 1 0%
Additional AMD Source Control Is
Remedial Design 20%
Construction Management 15%
20.35 120 $ 2,435
SUBTOTAL $ 33,005
$ 2,640
$ 9,901
SUBTOTAL $ 45,547
$ 4,555
$ 500,000
$ 9,109
$ 6,832
SUBTOTAL $ 520,496
Proprietary Controls for Mine Waste Areas Is $ 400.00 1 $ 400
TOTAL CAPITAL COSTS
$ 566,443
| Source of Cost Data
ECHOS2000; 17-03-0101;
ECHOS2000; 17-01-0105;
Engineering Estimate
Engineering Estimate
ECHOS 2000; 19-02-0126;
ECHOS 2000; 33-05-0802;
Engineering Estimate
Means 2000; 02920-510-4500, 02920-510-7000
Means 2000; 02910-500-0350
ECHOS 2000; 18-04-0107;
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
Engineering estimate
EPA Cost Guidance
EPA Cost Guidance
4 hours per property @ $100/hr legal fees
Cost Tables B-2 to B-17.xlsAD4B BG
-------
Table B-14
Estimated Capital Cost for Selected Remedy
Surface Water
Alternative SW3C: Additional Water Storage (Chessman Reservoir)
Subarea: Beaver Creek
Item Ur
it Unit Cost
Land acre $ 2,000.00
Clearing and grubbing acre $ 5,370.00
Raise/modify shoreline berms cy $ 7.90
Main Dam - raise 6 feet
Raise Cutoff Wall cy $ 350.00
Modify inlet/access/control structures Is $ 50,000.00
Imprevious Fill cy $ 25.98
Salvage/supplement riprap cy $ 20.00
Saddle Dam - raise 6 feet
Raise Core Wall cy $ 350.00
Impervious and Unclassified Fill cy $ 25.98
Salvage/supplement riprap cy $ 20.00
Filter Fabric sy $ 1.04
Replace flume with pipeline If $ 73.96
Erosion control mat sy $ 1.11
Fencing If $ 2.18
Mobilization/Demobilization, Bonding, and
Insurance
8%
Quantity
16
16
3,400
94
1
13,000
2000
40
2,000
1,000
4,500
25350
5,000
250
SUBTOTAL
Construction Contingencies 30%
Project Management
Remedial Design
Construction Management
TOTAL CAPITAL COSTS
5%
8%
6%
SUBTOTAL
SUBTOTAL
Cost
$ 32,000
$ 85,920
$ 26,860
$ 32,900
$ 50,000
$ 337,740
$ 40,000
$ 14,000
$ 51,960
$ 20,000
$ 4,680
$ 1,874,886
$ 5,550
$ 545
$ 2,577,041
$ 206,163
$ 773,112
$ 3,556,317
$ 177,816
$ 284,505
$ 213,379
$ 675,700
$ 4,232,017
| Source of Cost Data
Engineering Estimate
Means 2000; 02230-200-0200 & 0250
ECHOS2000; 17-03-0423
Engineering Estimate
Engineering Estimate
ECHOS 2000; 17-03-0428 (30 mile haul)
Engineering Estimate
Engineering Estimate
ECHOS 2000; 17-03-0428 (30 mile haul)
Engineering Estimate
ECHOS 2000; 33 08 0532
City of Helena Estimate
Means 2000; 02370-550-0010
ECHOS 2000; 18-04-0110
Engineering Estimate
20% Scope, 10% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
Cost Tables B-2 to B-17.xlsSW3C Chessman
-------
Table B-15
Estimated Capital Cost for Selected Remedy
Residential and Recreational Yard Soil
Alternative RY3B: Excavation with Disposal in Luttrell Repository
Subarea: Tenmile Creek Near Rimini
Item Unit
Site preparation and storm water control acre $
Excavate yard soil (ave depth = 4 feet) cy $
Transport waste cy-mile $
Spread and compact waste cy $
Luttrell Repository disposal cy $
Utility Relocation ea $
Unclassified fill cy $
Place 12" coversoil cy $
Install Sod sf $
Mobilization/Demobilization, Bonding, and
Insurance 8%
Construction Contingencies 15%
Project Management 6%
Remedial Design 12%
Construction Management 8%
TOTAL CAPITAL COSTS
Unit Cost Quantity
13,900.00 7.03
1.98 45,347
0.60 421,727
3.14 45,347
5.00 45,347
500.00 23
5.00 34,010
12.00 11,337
0.25 306,092
SUBTOTAL
SUBTOTAL
SUBTOTAL
Cost
$ 97,674
$ 89,787
$ 253,036
$ 142,389
$ 226,735
$ 1 1 ,500
$ 170,051
$ 136,041
$ 77,747
$ 1,204,961
$ 96,397
$ 180,744
$ 1,482,102
$ 88,926
$ 1 77,852
$ 118,568
$ 385,346
$ 1,867,448
| Source of Cost Data
ECHOS 2000; 17-01-0105, 33-05-0802
Means 2000; 02315-400-0260, 0020 (loading)
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
Engineering Estimate
Engineering Estimate
Means 2000; 02920-600-0010
Engineering Estimate
10% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
Cost Tables B-2 to B-17.xlsRY3B TR
-------
TableB-16
Estimated Capital Cost for Selected Remedy
Residential and Recreational Yard Soil
Alternative RY3B: Excavation with Disposal in Luttrell Repository
Subarea: Tenmile Creek Mainstem
Item Unit
Site preparation and storm water control acre $
Excavate yard soil to 30 inch depth cy $
Transport waste cy-mile $
Spread and compact waste cy $
Luttrell Repository disposal cy $
Utility Relocation ea $
Unclassified fill cy $
Place 12" coversoil cy $
Install Sod sf $
Mobilization/Demobilization, Bonding, and
Insurance 8%
Construction Contingencies 20%
Project Management 8%
Remedial Design 15%
Construction Management 10%
TOTAL CAPITAL COSTS
Unit Cost Quantity
13,900.00 1.1
1.98 4,413
0.60 69,725
3.14 4,413
5.00 4,413
500.00 4
5.00 2,648
12.00 1,765
0.25 47,656
SUBTOTAL
SUBTOTAL
SUBTOTAL
Cost
$ 15,207
$ 8,738
$ 41,835
$ 13,857
$ 22,065
$ 2,000
$ 13,240
$ 21,180
$ 12,105
$ 150,227
$ 12,018
$ 30,045
$ 192,290
$ 15,383
$ 28,844
$ 19,229
$ 63,456
$ 255,746
| Source of Cost Data
ECHOS 2000; 17-01-0105, 33-05-0802
Means 2000; 02315-400-0260, 0020 (loading)
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
Engineering Estimate
Engineering Estimate
Means 2000; 02920-600-0010
Engineering Estimate
15% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
Cost Tables B-2 to B-17.xlsRY3B TM
-------
TableB-17
Estimated Capital Cost for Selected Remedy
Contaminated Roadway Materials
Alternative RD3B: Excavation with Disposal at Luttrell Repository (5,000 Feet)
Subarea: Tenmile Creek Near Rimini
Item Unit
Site preparation and storm water control acre $
Excavate roadway cy $
Transport waste cy-mile $
Spread and compact waste cy $
Luttrell Repository disposal cy $
Utility Relocation Is $
Replace 24 inch city water line If $
Unclassified fill cy $
Place 12" base course cy $
Place 6" top course cy $
Mobilization/Demobilization, Bonding, and
Insurance 8%
Construction Contingencies 15%
Project Management 8%
Remedial Design 15%
Construction Management 10%
TOTAL CAPITAL COSTS
Unit Cost Quantity
13,900.00 4
1.98 23,328
0.60 216,948
3.14 23,328
5.00 23,328
5,000.00 1
81 .00 800
5.00 17,031
10.00 6,296
15.00 3,148
SUBTOTAL
SUBTOTAL
SUBTOTAL
Cost
$ 54,247
$ 46,189
$ 130,169
$ 73,249
$ 116,639
$ 5,000
$ 64,800
$ 85,157
$ 62,963
$ 47,222
$ 685,636
$ 54,851
$ 102,845
$ 843,332
$ 67,467
$ 126,500
$ 84,333
$ 278,300
$ 1,121,631
| Source of Cost Data
ECHOS 2000; 17-01-0105, 33-05-0802
Means 2000; 02315-400-0260, 0020 (loading)
EPA Cost Estimate
ECHOS 2000; 17-03-0422
EPA Cost Estimate
Engineering Estimate
Means 2000; 02510-810-3010
Engineering Estimate
Engineering Estimate
Engineering Estimate
Engineering Estimate
10% Scope, 5% Bid
EPA Cost Guidance
EPA Cost Guidance
EPA Cost Guidance
Cost Tables B-2 to B-17.xlsRD3B(5000) TR
-------
Appendix C
Page Proposed Plan Comments and Responses C-l
Draft Proposed Plan Comments and Responses C-52
Public Hearing Comments and Responses C-104
-------
Proposed Plan Comments and Responses
-------
Comment Letter on Proposed Plan from John Arrigo - November 20,
2001
Response
November 20, 2001
Mike Bishop
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, MT 59626
RE: Upper Tenmile Proposed Plan
Dear Mr. Bishop:
Overall I believe EPA has done an excellent job evaluating the extent of
contamination and has been creative and thoughtful in its design of
remediation proposals. However I do have some specific comments and
concerns. My comments on the proposed remediation plan for the Upper
Tenmile Creek Mining Area Site are as follows
1. On several occasions in the recent past, storm water runoff from the
Chessman Road has flowed into Beaver Creek and ultimately resulted
in the discharge of extremely turbid water into Tenmile Creek. This
periodic, historic discharge contributes suspended and dissolved
solids and other pollutants to Tenmile Creek that may have caused or
will cause impacts. The enclosed copies of color photos were taken
on July 30, 1998 while I was driving up the drainage during one of
these runoff events. The upper right picture shows a clear Tenmile
Creek before I encountered the slug of turbid runoff. The picture on
the middle right shows Tenmile Creek after the turbid slug had mixed
with the stream flow. The other photos on the left show evidence of
runoff from the
EPA notes that the runoff from Chessman Road can be a source of
sediment loading to Beaver Creek and to Tenmile Creek. EPA did not
sample Chessman Road during the RI because there has been no
indication that parts of the road might be constructed of mine wastes.
In Rimini, sampling of the roadway was conducted because there was
a record that mine wastes from the Susie mine were used to rebuild
the road after the 1981 flood. The Rimini road sampling confirmed
the presence of mine wastes. In the case of the Chessman Road, the
sediment load into the creek would be expected to be similar in
chemical composition to that form storm erosion from any
unimproved road within the watershed. The increase is suspended
solids being
Upper Tenmile Creek ROD
C-1
-------
Comment Letter on Proposed Plan from John Arrigo - November 20,
2001
Response
Chessman Road. Has EPA considered the Chessman Road as a source
area for metals addition to the Tenmile Creek drainage system? Has
EPA collected soil samples from the Chessman Road to verify the
presence or absence of metals? Would EPA work with the Forest
Service to improve drainage on this road? If you would like to view
other photos, please contact me.
2. The proposed plan recommends institutional controls to prevent the
installation of new wells. To what degree will EPA better define the
nature and extent of ground water contamination and tailor the
boundaries of the ground water control area to the contaminated
zones? Ground water in the vicinity of my well at 3604 Rimini Road
is below levels of concern. However, with the institution of a control
area that covers the general Rimini area, I may not be able to drill a
new well to access the existing "clean" ground water beneath my
property.
2.
transported into Beaver Creek are of concern to aquatic life, but
suspended sediments resulting from non-mining sources cannot be
addressed under Superfund. Remedial actions by EPA taken to
address mining-related contamination will involve road
improvements for specific mine sites. In accordance with reclamation
ARARs, EPA will implement best management practices to control
stormwater runoff and erosion during remedial action. For those
actions that involve use of the Chessman Road, such as the Upper
Valley Forge removal by USFS, appropriate drainage and erosion
control will be implemented for those portions of the road affected.
DEQ is beginning to develop a total maximum daily load (TMDL)
allocation plan for the upper Tenmile Creek watershed, which will
address sediment loads in the watershed streams. EPA has developed
a water quality model for Tenmile Creek that will be available for use
during TMDL analysis
The RI relied on water quality data from existing wells to
characterize the nature and extent of the groundwater contamination
in Rimini and at other locations of the site. New monitoring wells
were not drilled. Although the depth and spacing of the existing wells
was not adequate to definitively model the exact extent and possible
movement of the groundwater contamination in and near Rimini,
EPA believes that the prevalence of groundwater contamination in
Rimini and the need for a controlled groundwater area were well
established by the existing data. There were wells
Upper Tenmile Creek ROD
C-2
-------
Comment Letter on Proposed Plan from John Arrigo - November 20,
2001
Response
located in all directions from the referenced well that exhibited
various levels of contaminated ground-water, so the extent of the
"clean" zone around that well is uncertain.
Without expending considerable time and expense to define the
Rimini groundwater situation more precisely, EPA has chosen to use
a three-step process for addressing contaminated groundwater
currently used by Rimini residents. The first step, temporarily
providing bottled water or individual treatment systems to residents
with groundwater contamination above maximum contaminant levels
(MCLs) is already in place. The second and third steps are contained
in the selected remedy. A community water system, using a clean
groundwater source, will be constructed by EPA and turned over to
the community of Rimini for operation. The community water system
would replace the need for individual wells within the immediate
Rimini vicinity, to be used for drinking water. The third step will be
the creation of a controlled groundwater area to ensure that
contaminated groundwater is not used for drinking water purposes.
It is important to note that there is wide latitude in establishing well
restriction s under a controlled groundwater area (CGWA). A CWGA
does not necessarily mean that a "well ban" will be put in place; it
may simply require that newly installed wells be sampled and the
water be treated or not consumed for drinking water purposes if
found to be contaminated. Additional sampling and/or monitoring
well installation may be necessary to establish the CWGA. From
Upper Tenmile Creek ROD
C-3
-------
Comment Letter on Proposed Plan from John Arrigo - November 20,
2001
Response
How many of the new haul roads will be reclaimed and to what
condition? I am concerned about the number, size and length of any
new roads that must be installed to remove mine waste from the
proposed 70 Category C, D and E sites. Does the risk posed by these
waste sites justify the construction of a road to each site for removal?
4. I and other residents are concerned about the lack of specificity given
for the proposed public water supply system operation and
maintenance costs. I recognize that it is early in the process to
formally evaluate and quantify these costs. The normal process a
water district would follow to design, fund, construct and operate a
public water supply system would include an initial needs analysis
and a facility planning process that evaluates several options and
quantifies anticipated construction, operation and
EPA's perspective, the importance of the CGWA is to prevent
uncontrolled drilling of wells in contaminated aquifer zones.
The mine site scoring and ranking procedure took into account the
level of access to the sites. Low priority sites were often scored as
low priority because there was no current access and therefore
reduced potential for exposure to site contaminants. However, most
of the high priority mine sites (category C, D, and E) are relatively
close to substantial roads and have some level of current access road
directly to the sites. It will generally be necessary to upgrade the
existing roads to allow construction equipment to access the mine
sites. EPA will work with each property owner affected by the road to
define the road dimensions and specifications. EPA's preferred
approach will be to reclaim the new roads, after site remediation, to
the general condition of the road prior to cleanup. Additional
discussion of access roads is provided in the response to the comment
letter from the Montana Department of Fish Wildlife and Parks.
Consistent with Superfund guidance, the FS and proposed plan
evaluated and summarized several alternatives for developing a
community water system for Rimini, including a feasibility-level
evaluation of system construction and operation and maintenance
(O&M) costs. Details for the cost estimates for the different
alternatives were presented in the FS, and have since been refined in
the addendum to the draft RI and draft FS reports. The purpose of the
feasibility-level evaluation is to compare a reasonable range of
possible
Upper Tenmile Creek ROD
C-4
-------
Comment Letter on Proposed Plan from John Arrigo - November 20,
2001
Response
maintenance costs. EPA should contact each resident individually and
attempt to quantify who wants to be connected to the new supply,
who might want to be connected and who does not want to be
connected. This would be better than just stating EPA will construct a
system to serve up to 50 connections. It may be that less than 20
homes will realistically be connected. In this case, would it be wise to
size a system to serve 50 connections? Although I know EPA
contractors will design a system that meets existing standards, I am
not confident that multiple options and associated costs will be
analyzed and presented to the residents for consideration. The
residents will likely be unwilling to form a county water district if
they are not confident in the anticipated costs of operating and
maintaining the system. Can EPA provide funding to task a
contractor to better quantify the required size and anticipated
operation and maintenance costs? Another method to facilitate the
formation of a county water district would be for EPA to fund a
contractor to assist the residents in
formation of a district.
alternatives. The analysis assumed a reasonable number of
connections, given EPA's knowledge of the community, so that the
alternatives could be equitably compared. Capital and O&M costs
were estimated using sound engineering costing principles and
professional judgment.
Detailed cost estimates will be prepared during remedial design. EPA
will work with Rimini residents who are proceeding with plans to
form a rural water and sewer district to ensure that the designed
system is appropriate for the community's need and that the
community can afford to operate and maintain the system.
Thank you for the opportunity to comment on the plan. Your personal
involvement and dedication through this tedious process is appreciated. If
you would like to discuss any of my comments further, please feel free to
contact me.
Sincerely,
John Arrigo
3604 Rimini Road
Helena, MT 59601
Upper Tenmile Creek ROD
C-5
-------
Comment E-mail on Proposed Plan from Craig French, Montana
Department of Environmental Quality - November 20, 2001
Response
Upper Tenmile Proposed Plan Comments
From DEQ
November 20, 2001
A. Table 2, page 16, Implementability, Alternative 4:
Talks about "locating four acres of sludge drying beds near Rimini..."
and since there is not a discussion of sludge beds in Alternative 4, this
looks like an artifact from earlier discussions involving treatment.
B. Since operating biological/ wetland treatment facilities is a
challenging undertaking, the DEQ would like to be involved in all
design activities. Perhaps a thorough design with
A. Alternative 4 addresses acid mine drainage with a four-phase
program to first implement source controls and flow reduction actions
at discharging adits and then implement water treatment actions if
EPA determines, in consultation with DEQ, that treatment is
necessary to meet state ambient water quality standards. In order to
develop appropriate cost estimates for the proposed plan, based on its
current knowledge of the contaminant loading for the three key adit
discharges in the Rimini area (Red Water, Susie, and Lee Mountain),
EPA assumed that physical/ chemical treatment would be the Rimini
adit discharges. The treatment would probably involve lime
precipitation and activated alumina or reverse osmosis, which would
create a sludge byproduct that would have to be dried and disposed of
in the Luttrell repository. The least expensive method of handling the
treatment sludge is dewatering in sludge drying beds. Approximately
4 acres would be necessary for the drying bed if adit flow rates and
contaminant loading is similar to present conditions. If the effort to
control sources and reduce flows is successful, then treatment may
not be necessary or the size of the treatment facility, and associated
sludge drying beds, may be reduced.
B. EPA expects DEQ to be an integral partner in the implementation of
all aspects of the four-phase program to address acid mine drainage,
including the monitoring,
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-6
-------
Comment E-mail on Proposed Plan from Craig French, Montana
Department of Environmental Quality - November 20, 2001
measurable parameters that indicate the efficiency and longevity of the
treatment facility would aid in the operation of said facilities. Such
parameters that could be evaluated to indicate the health of the sulfate
reducing bacteria (SRB) population, that is, if SRB are required, would
be helpful. Also, DEQ is looking forward to learning the intricacies of
biological treatment systems operation during the shakeout period.
Response
evaluation, development/ implementation of bench scale and
pilot-scale tests, and design/ construction of full scale passive/
biological treatment systems.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-7
-------
Comment Letter on Proposed Plan from Michael Korn, Montana
Department of Fish, Wildlife and Parks- October 30, 2001
Response
October 30, 2001
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, MT 59626
Dear Mr. Bishop:
Please consider this letter is Montana Fish, Wildlife and Parks comments
on the Proposed Plan for the Upper Tenmile Creek Mining Area under
provisions of Section 117(a) of the comprehensive Environmental
Response, Compensation and Liability Act of 1980, 42 USC Section
9601 et seq. (CERCLA or Superfund) and Section 200.430(f)(2) of the
National Oil and Hazardous Substance Pollution Contingency Plan.
Comments here address fish and wildlife issues, although, for the record,
we support the cleanup efforts to improve drinking water and soil
conditions for residents of the Rimini area.
A. We applaud the long-term, coordinated efforts to re-water Tenmile
Creek as described in the Proposed Plan. We endorse the decision to
substitute improved storage capacity of Chessman Reservoir instead
of reservoir development of Tenmile Meadows. However, no
discussion was provided about dewatering of drainages that will
provide water to Chessman, and the consequences that the diversion
will have on local hydrology, vegetation and wildlife. We
recommend that this be addressed in the final document. It is not
clear whether some water would remain in tributaries that are
providing water to Chessman via the Red Mountain flume,
A. The primary source of water to fill Chessman Reservoir currently is
surplus snowmelt and spring runoff water diverted from the Banner
Creek drainage to Chessman through the Red Mountain flume. Under
a court decree for water rights, the City of Helena is allowed to divert
this water each year only prior to the first call for irrigation water
downstream. Since diversion through the Red Mountain flume occurs
only during the late spring and early summer when there is excess
water, there is no dewatering of Banner Creek during this period. The
proposed capacity improvements to both Chessman Reservoir and the
Red
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-8
-------
Comment Letter on Proposed Plan from Michael Korn, Montana
Department of Fish, Wildlife and Parks- October 30, 2001
Response
and if so how much. Please provide this information.
In our correspondence of September 25, 2001, we raised several issues
that we hoped would be addressed in the Proposed Plan, including:
B. The importance of factoring in impacts to wildlife from the clean-up
procedure itself, particularly impacts of upgraded roads. We realize
that this must be a coordinated effort with the Helena National Forest.
We asked that an evaluation be conducted, and measures taken to
assure that increased motorized access to the Tenmile Watershed not
be encouraged. Improved road conditions will lead to increased
public use post-clean up, and this issue should be taken into account
in planning which roads would remain on the landscape. While the
current plan is to bring some of the haul roads back to a certain width,
road surfaces already are better than they were pre-project. We
recommend coordination between the EPA (to provide necessary
funding) and the Helena National Forest (to provide travel
management) to minimize secondary motorized impacts to wildlife
and their habitat.
Mountain flume are intended to allow the city to divert and store
additional water, but the diversion would still occur during the period
of excess runoff water and would not dewater Banner Creek. In
addition, the proposed improvements to the flume are expected to
reduce current losses from the flume that result from the ditch being
unlined. Additional information regarding the availability of water
under the three reservoir alternatives is provided in the addendum to
the draft RI and draft FS reports.
B. EPA received a number of comments on the issue of potential impact
to wildlife caused by upgrading and improving access roads to
implement the remedial action for the site. EPA is committed to
implementing the mine site cleanups in a manner that holds impacts
on wildlife to a minimum. As with any construction action,
short-term impacts during construction are expected. It is EPA's
intent to reclaim access roads after cleanup and leave mine site access
in a condition similar to that before the cleanup. During the design
process, there will be ample discussion with affected landowners,
USFS, DFWP, and other parties to determine the appropriate road
specifications for each mine site and each area of the Tenmile Creek
watershed. EPA plans to defer to USFS regarding potential area
closures and travel restriction plans within the Helena National
Forest; EPA will prepare its design plans to be consistent with USFS
plans.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-9
-------
Comment Letter on Proposed Plan from Michael Korn, Montana
Department of Fish, Wildlife and Parks- October 30, 2001
Response
C. Recognition that a six-mile segment of the Continental Divide
wildlife movement corridor has seriously disturbed as a result of
mining activity and now Superfund Cleanup procedures.
D. Protection of the less suitable but alternate wildlife movement
corridor that appears to have developed from near Jericho Mountain
on the Divide, across Tenmile Creek and into the Black Mountain
road-less area, to the Park Lake-Occidental Plateau-Cataract Basin
area, and across the Boulder Divide to the Elkhorn Mountains.
Critical to protection of this corridor is assurance that the Beaver
Creek road not be upgraded in any way that would increase
motorized traffic over pre-project levels.
C. The comment is noted.
E. Not widen and pave the Rimini road as proposed for Route 98 (a
scenic forest highway.) That highway is proposed to end at the mouth
of the Beaver Creek Road. This road should not have additional
traffic if the alternate wildlife movement corridor is to be protected.
F. Commitment by the Forest Service to enforcing off-road vehicle use
restrictions in the watershed for at least 5 years.
G. These issues were not addressed in the Plan that was issued
in late October. In addition, we feel that the solicitation on
D. The comment is noted. There are several high priority mine sites that
will probably require use of the Beaver Creek road (referred to as the
Chessman Road in other comments) for transport of mine wastes to
the Luttrell repository. The specifications for any improvements to,
and post-project reclamation of, the Beaver Creek road necessary for
the waste haul will be developed during remedial design in full
consultation with MDFWP and USFS. It would be premature at this
time, without considering all haul road options and their relative
impacts on the success of mine site cleanups in the Beaver Creek
drainage, to make a commitment that the Beaver Creek road would
"not be upgraded in any way."
E. The referenced scenic forest highway improvement to Route 98 has
no connection to EPA Superfund action.
F. EPA will work closely USFS to coordinate its actions with USFS
land management requirements. Management of those public lands
remains the responsibility of USFS.
G. As noted earlier, detailed road specifications will be developed in
consultation with all affected parties during the
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-10
-------
Comment Letter on Proposed Plan from Michael Korn, Montana Response
Department of Fish, Wildlife and Parks- October 30, 2001
page 23 requesting points of view regarding access to the watershed remedial design process.
does not sufficiently address wildlife habitat issues. We believe that
coordination between the EPA and the Helena National Forest is
essential to achieve these objectives. Forest Service standards for
road densities currently exist (less than 1.8 miles of road per square
mile) and we believe that they should be utilized in this project. We
also wish to see that analysis include all motorized uses, including
non-system and user created routes as well as system roads.
We offer our assistance as this process moves forward and hope that we
can bring together both the objectives of the clean up while at the same
time considering the needs offish and wildlife in the area.
Sincerely,
Michael Korn
Helena Area Coordinator
c: Larry Peterman, FWP Chief of Field Operations
Pat Flowers, Supervisor FWP Region 3
Tom Clifford, Helena National Forest Supervisor
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C-11
-------
Comment Letter on Proposed Plan from Tom and Caroline Hattersley •
November 21, 2001
Response
Tom and Caroline Hattersley
71 Highland Meadow Road
Clancy, MT 59634
November 21,2001
Via U.S. Mail and E-Mail (bishop.mike@epa.gov)
Mr. Mike Bishop
U.S. Environment Protection Agency
301 South Park
P.O. Box 1006
Helena, MT 59626
Re: Ten Mile Creek Watershed
Dear Mr. Bishop:
I am writing to you concerning an article I read recently in the Helena
Independent Record which discussed certain cleanup efforts planned for
the Ten Mile Creek Watershed. The article only vaguely referenced plans
to capture runoff in the "Travis Creek" area, and hold it in a proposed
reservoir. I live in the Travis Creek area (and watershed), in Jefferson
County, and my wife and I are vitally concerned about any activity which
may jeopardize or otherwise impact the Travis Creek watershed. I might
add that neither my wife nor any of our neighbors with whom we have
discussed this recent article have ever been notified or made aware in any
way of the fact that the Travis Creek watershed may be affected by any
cleanup plans for Ten Mile Creek. That area is not within the
Independent Record circulation zone and delivery is not available to us.
The Travis reservoir site referred to in the proposed plan is located at the
headwaters of Tenmile Creek, near the continental divide, southwest of
the community of Rimini. Figure 2 in the proposed plan accurately
depicted the location of the potential reservoir location. The site was
presumably named after the individual who historically developed it as a
small reservoir. The proposed Travis reservoir site is not located in the
Travis Creek watershed, noted to be of concern in the Hattersley letter.
Additionally, neither the preferred alternative in the proposed plan or the
selected remedy in this ROD included the development of a reservoir at
the Travis location on upper Tenmile Creek. Rather, in both documents
the proposed action is to upgrade Chessman Reservoir to allow for
additional water storage.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-12
-------
Comment Letter on Proposed Plan from Tom and Caroline Hattersley - Response
November 21, 2001
Today, I phoned your office and learned that you were out for the day,
but I did speak with your colleague Jim Harris. Mr. Harris gave me your
name and address and suggested that we write to you with our concerns.
Mr. Harris also arranged for me to obtain a copy of the "Proposed Plan,"
which I picked up this afternoon. We briefly reviewed that plan, which
makes reference only to possible construction of a reservoir at one of two
potential locations, "Travis (on Upper Terunile Creek) or Banner Creek."
We are not familiar with a separate "Travis Creek" near the location
depicted for a potential "Travis Reservoir Site" on Figure 2 in the Plan
document.
The Travis Creek which is the subject of our concern lies to the north of
Chessman Reservoir, and flows east out of Black Hall Meadows, which
lies directly north of Chessman Reservoir.
The Travis and Banner Creek proposed reservoir location, on the other
hand, appears to lie west of Scott Reservoir. We would appreciate
clarification of which "Travis Creek" is involved. Our comments are
specifically focused on the Travis Creek which has its headwaters in the
mountains surrounding Black Hall Meadows.
We have resided in the Travis Creek area for close to 20 years. In fact,
Travis Creek runs through our property. We have several wells on our
property, and have livestock water rights in the creek. Over the many
years we have lived in this area, we have regularly hiked, and ridden our
horses, and bicycles, throughout it. We are very familiar with Colorado
Mountain, Black Hall
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C-13
-------
Comment Letter on Proposed Plan from Tom and Caroline Hattersley - Response
November 21, 2001
Meadows, Travis Creek, and the North Fork of Travis Creek.
Our greatest concern is that any activity in the Travis Creek watershed, in
particular planning designed to capture and divert sources of additional
water for Helena, will have a dramatic adverse impact on that watershed.
The last four or five years of drought have already significantly impacted
this area. The water table appears to have dropped significantly, springs
have dried up, and the creek stopped flowing for a period of time.
Travis Creek is an important part of the main creek flow running all the
way down Travis Creek Road and Lump Gulch to Clancy. There are a
number of homes with more being constructed all the time, within the
Travis Creek drainage, particularly as the creek makes it way to Clancy.
Aside from the obvious importance of the water table and aquifer to the
many residents within the watershed, the creek and the numerous springs
in the area are also an important water source for livestock and wildlife.
The Travis Creek watershed area is perhaps as beautiful as any land in
this State. It is virtually all either a roadless area or within a motor
vehicle restricted area. Blackball Meadows is now a roadless area, and is
a favored area for hikers and other recreationalists throughout the greater
vicinity.
This watershed in its entirety is host to a significant wildlife population,
including everything from hawk, owl, and eagle populations to deer and a
large number of moose, among other
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C-14
-------
Comment Letter on Proposed Plan from Tom and Caroline Hattersley - Response
November 21, 2001
animals.
We are not aware of any details concerning the plan for the Ten Mile
cleanup. However, we don t need to know very much about any plan to
capture and divert snow melt or other runoff and water sources in the
Travis Creek watershed to realize that any such plan will jeopardize and
perhaps severely affect the watershed and its inhabitants, human or
otherwise.
If the Plan affects the Travis Creek we are describing, please add us to
your list and provide us with any information you can which bears upon
that Travis Creek area.
We have spoken with neighbors and acquaintances in the area after
seeing the recent article. None of them were aware of any activity which
would affect the Travis Creek watershed. Hopefully, some effort can be
made to inform the people who will be most impacted as residents of the
area so they can comment and provide input.
For purposes of responding or placing us on your notice list please use
the following contact address and phone number:
Tom and Caroline Hattersley
71 Highland Meadow Road
Clancy, MT 59634
Phone No. (406) 449-2547
I can also be reached at my office address and phone number:
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C-15
-------
Comment Letter on Proposed Plan from Tom and Caroline Hattersley - Response
November 21, 2001
Gough, Shanahan, Johnson & Waterman
33 South Last Chance Gulch
P.O. Box 1715
Helena, MT 59624
Phone No. (406) 442-8560
Again, if we are describing concerns over a separate, and unaffected area,
please let us know and disregard these comments. Thank you, Mr.
Bishop.
Very truly yours,
Tom and Caroline Hattersley
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C-16
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20,2001
November 20, 2001
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, Montana 59626
Dear Mr. Bishop,
Re: Comments concerning Proposed Plan Upper Tenmile Creek
Mining Area Site, Lewis & Clark County, Montana.
Thank you for allowing us the opportunity to comment on the Proposed
Plan Upper Tenmile Creek Mining Area Site, Lewis Clark County,
Montana (October 2001) and the Preferred Alternative (October 2001).
Lewis & Clark County's (County) comments from the Planning, Health,
and Public Works Departments have been consolidated in this letter for
your consideration. Comments are in the order of the layout of the
Preferred Alternative as presented on page 4 of the Proposed Plan.
A. Waste Rock and Tailings
The County supports the Preferred Alternative approach of removal
of waste rock and tailings from the higher priority mine sites with
disposal in the Luttrell repository.
B. Acid Mine Drainage
The County supports the concept of a phased effort to minimize
drainage of storm water and snowmelt into mine workings by capping
and regrading collapsed shafts/ adits
Response
A. The comment is noted.
B. The comment is noted. During remedial design, EPA will continue to
consult with the Lewis & Clark City-County Health Department
regarding the protection of water quality and the protection of public
health.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-17
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20,2001
Response
and constructing drainage diversions at mine workings, followed by
design and construction of treatment facilities for acid mine drainage.
The County supports the collaborative effort of the EPA and State of
Montana in the operation of these treatment facilities to ensure that
the acid mine drainage will be brought in compliance with the state
ambient water quality standards. The County requests that as the
phased program proceeds into the design and planning of the
treatiment facilities that the EPA would continue to consult with the
Lewis & Clark City-County Health Department regarding water
quality protection and protection of public health in that planning
process.
C. Groundwater
The establishment of institutional controls is necessary to prevent
installation of new drinking water wells in the contaminated aquifers
of the Rimini area. However, the County is concerned that the
Proposed Plan does not address institutional controls to prevent the
ongoing use of the existing contaminated wells and the potential for
this use of water from the contaminated wells to contribute to
spreading contaminant metals to surface waters and the clean yard
soil through irrigation and other future uses. The County believes it
may be necessary to provide for the capping and/or abandonment of
existing wells that are contaminated, once an alternative water supply
system is provided, to prevent this cross contamination problem.
EPA has conducted brief conservative mass balance loading
calculations for arsenic to evaluate if there is potential for significant
build-up of arsenic in soils from watering with contaminated
groundwater. Using conservative assumptions (watering 0.25 inches
per day for 90 days, groundwater arsenic concentration =100 j^g/L,
all applied arsenic remains in the top 2 inches of soil [i.e., there is no
flushing of arsenic from the soil profile from uncontaminated rainfall
or snowmelt], "clean" yard soil conditions are similar to sitewide
background [arsenic concentrations start at 50 mg/kg]), EPA
estimates it would take approximately 200 years of watering for the
arsenic to approach levels that would be of concern to human health.
With the expectation that some flushing would occur and that yards
replaced with clean soils imported from outside of the site would
have much lower arsenic concentrations to begin with, EPA has
concluded that there is very slight risk of arsenic building up
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-18
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20,2001
Response
D. Surface Water
The County supports the Proposed Plan's Preferred Alternative of
expanding Chessman Reservoir and improving the Red Mountain
flume, thereby allowing the City of Helena to release stored water
into Tenmile Creek during the low flow summer season. The
augmentation of stream flow will have beneficial effects on water
quality and the fish habitat potential of the entire Tenmile Creek
system. Water rights issues must also be addressed to ensure that the
additional flows remain in the stream beyond the limits of the Upper
Tenmile Creek Mining District Area.
We believe that increased streamflow will benefit water quality in the
Lower Tenmile Creek stream reaches. Flow augmentation will also
benefit residents and other users of both the Tenmile Creek and the
lower Prickly Pear Creek
in the soils to concentrations of concern and that there is no reason to
restrict use of groundwater for irrigation.
The final location, size, and restrictions of the controlled groundwater
area would be determined through a technical application and public
review process. The controlled groundwater area may not require a
ban on groundwater wells. At other contaminated groundwater sites,
it has been possible to allow new wells to be installed as long as the
groundwater is sampled and not used for drinking water if found to be
contaminated. Rimini residents may be able to use their current wells,
or even drill new wells, for irrigation purposes.
D. The comment is noted. EPA is coordinating with DFWP and the City
of Helena to encourage the execution of an instream flow reservation
by DFWP for fisheries enhancement that would ensure that the water
remained in lower Tenmile Creek.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-19
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20,2001
Response
watersheds. This action will enhance local efforts to ensure that these
streams meet the state and federal requirements for water quality and
beneficial uses, uses that are currently impaired by historic mining
activities within the Upper Tenmile Creek Mining Area Site.
E. Stream Sediments
The County agrees with Proposed Plan to evaluate the stream
sediments after the waste rock and acid mine drainage cleanups to
determine the future need for removal and disposal in the Luttrell
repository.
F. Residential and Recreational Yard Soil
The County supports the Proposed Plan for removal and replacement
of contaminated soils within residential and recreational yards.
However, because this is a one-time effort in a small community, the
County requests that the EPA reconsider the proposed excavation
level for lead. The County supports the reduction of the excavation
level for lead to 400 parts per million (ppm) to match the recent
TSCA Section 403 Residential Lead Hazard Standard. We believe a
one-time cleanup to this more stringent standard will be the best
protection for future generations of residents and users of the land
and will be protective of the children within the community.
The County recommends that once EPA completes the yard
replacement effort, institutional controls be implemented
drainage-wide to prevent or minimize future land use actions that
would reintroduce contaminated subsurface soils to
E. The comment is noted.
F. The referenced Toxic Substances Control Act (TSCA) Section 403
standard is a two-part standard that recommends an excavation level
of 400 ppm for child play areas with bare soil and an average level of
1,200 ppm for bare areas within the remainder of the yard. The EPA
TSCA guidance is not Superfund-related and is intended for
application where site information or contaminant concentration data
are not available. It was developed using national default input
parameters in the IEUBK model for lead exposure. For this site,
EPA's proposed remediation and target cleanup levels were
developed also using the IEUBK model, but refining its use with
regional input parameters thought to be more appropriate for this site.
EPA also notes that the residential yard component of the selected
remedy will be driven primarily by the concentrations of arsenic in
the yard soils. Preliminary remedial design sample results for
approximately 30 yards in Rimini indicate that nearly all yards will
have to be remediated because arsenic
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-20
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20, 2001
Response
remediated areas. Institutional controls should include ongoing
education about the potential health risks of contaminated soils;
notification of previous remediation and notification of required
permit process prior to subsequent surface disturbances. All
notifications should be done in writing and recorded in the Lewis and
Clark County's Clerk and Recorder's Office. Future landowners
excavating basements or foundations for new buildings or performing
other land disturbance actions must do so in a manner that avoids
creating a new contamination problem. The institutional controls
could be similar to the permit system implemented in East Helena
that requires a permit for land disturbance. This system allows the
landowner to be informed of the risks and the appropriate methods of
handling the excavated soils.
G. Contaminated Roadway Materials
The County believes that other alternatives beyond the three
considered in the Proposed Plan should be evaluated. We specifically
support paving the existing road, thus encapsulating the waste rock
and tailings used to repair the road after the 1981 flood damage.
Although this alternative may have a higher initial capital cost, the
long term operational and maintenance costs, which are the
responsibility of the County, would be substantially reduced with a
paved roadway. Also paving will abate road dust problems for the
community and minimize detrimental impacts to the stream.
G.
concentrations are greater than the cleanup level of 96 mg/kg.
EPA agrees that institutional controls should be established by the
county to inform landowners about property conditions and prevent
the release of contaminated subsurface soils. Since the Rimini area
has such a small population, it may be possible to conduct an
educational and permitting program without significant cost. In
consultation with the state, EPA has determined that the remedy for
contaminated yard soils will require the excavation and disposal of all
accessible soils, not just the uppermost 18 inches. This approach
should effectively remove most contaminated soils in the Rimini
community and minimize the need for long-term institutional controls
to prevent contaminant remobilization and potential future exposure.
Based on this and other comments, EPA reevaluated the alternatives
for remediating the contaminated roadway materials. Including the
potential paving of that portion of the roadway in the residential area
of Rimini. Based largely on concerns expressed by the State of
Montana over the long-term maintenance of alternatives that would
leave contaminated roadway materials in place, EPA has selected
total removal and disposal of accessible contaminated materials as
the remedy for roadways. The remedy addresses approximately 5,000
feet of roadway within the community of Rimini. Excavation to depth
is expected to have greater short-term impacts to the community
during construction, but will provide a more secure and easy-to-
maintain remedy in the long-term.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-21
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20, 2001
Response
The 1998 Road Evaluation Report prepared by the Lewis & Clark
County Public Works Department provides estimates of the cost of
road paving. To lay 6 inches of crushed gravel and 2.5 inches of
asphalt overlay cost approximately $250,000 per mile. The projected
test area for the roadbed from the Chessman Reservoir turnoff to the
Martin residence or the City of Helena Tenmile Creek water intake is
a distance of approximately 1.5 miles. If paving is selected, project
planning should consider beginning the paving effort at the Chessman
Reservoir turnoff to link to the U.S. Forest Service and Federal
Highway Administration improvement project, which proposes to
pave Rimini Road to the Chessman Reservoir turnoff from the
conjunction with Highway 12.
The County is also concerned that the Preferred Alternative of the
Proposed Plan requiring excavation of the contaminated roadbed
materials to a depth of 18 inches with the transport of the waste to the
Luttrell repository and reconstruction of the road with clean material
having to be mined and trucked in would cause substantial disruption
of the community and have potentially more detrimental impacts to
the stream from the construction effort, then the current perceived
problem. Paving of the current roadbed would be the best long term
solution to the contaminated road base problem and minimize future
road maintenance and storm water runoff problems.
However, if paving of the roadbed is not the selected remedy the
County supports the RD2 alternative of regrading and
EPA does not believe that the portion of the road from the Beaver
Creek road turnoff to Rimini proper (approximately 2,500 feet)
exhibits significant potential risk from contaminated subsurface
roadway materials. The potential risk is limited because the road is on
national forest lands that will not be residentially developed,
effectively preventing the potential for future residential setting
exposure. Therefore, EPA does not propose to remove road materials
from that portion of the road. Paving of that section of the road could
be considered as part of the Federal Highway Administration project.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-22
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of
Commissioners - November 20, 2001
capping the roadway with 18 inches of clean road base material.
H. Rimini Water Supply
The County supports the Proposed Plan's objective to develop a
community water supply system for the residents of the Rimini area
to replace the contaminated groundwater supply wells. The new
groundwater source must be of sufficient quantity to meet the needs
of the current residents and must incorporate design capacity for
future growth and development. The County agrees with EPA that
this community water supply system must be owned and operated by
the users of the system.
The creation of a local water district would be an appropriate
mechanism to ensure fiscal responsibility for operational and
maintenance costs of the system and will provide the financial
mechanism to generate reserves to replace major equipment in the
future. The County strongly recommends that the formation of a
water and sewer district be undertaken at the beginning of this
process. This allows the new district to be in a position to deal with
the numerous wastewater issues of the community that must be
addressed in the future (i.e. outdated and failing septic systems and
floodplain restrictions). Creation of a water and sewer district
originally is much easier then trying to change a water district into a
water and sewer district later.
The County would like to commend the U.S. EPA for moving forward
with this cleanup effort in a timely fashion. We hope the
Response
H. The comment is noted. Rimini residents are currently attempting to
form a rural water and sewer district.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-23
-------
Comment Letter on Proposed Plan from Lewis & Clark County Board of Response
Commissioners - November 20, 2001
implementation of the final plan will progress as quickly as possible. The
County asks that the U.S. EPA continue to collaborate and consult with
Lewis & Clark County Health Department, Water Quality Protection
District, Planning Department, and Public Works Department in planning
and implementation efforts for this cleanup as appropriate.
Sincerely,
Lewis and Clark County
Board of Commissioners
Karolin J. Loendorf, Chair
Michael A. Murray
Anita L. Varone
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C - 24
-------
Comment Letter on Proposed Plan from Jim Posewitz, Orion/the
Hunters Institute - October 24, 2001
October 24, 2001
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, MT 59626
Dear Mike,
I have reviewed the "Proposed Plan, Upper Tenmile Creek Mining Area
Site, Lewis and Clark County, Montana October 2001 (The Plan). This
commentary is provided as part of the public participation response
required under Section 117(a) of the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, 42 USC Section
9601 et sea. (CERCLA or Superfund).
General Commentary
A. The project to clean up abandoned mine wastes and other
contamination in the Tenmile drainage is supported. Likewise the
preferred alternative is supported and we are pleased to note that
Chessman Reservoir and improvements to the Red Mountain flume
are part of the preferred alternative.
B. Page 1. "In a nutshell: EPA's Proposed Cleanup Plan"
We appreciate the decision to enhance water storage and stream flow
by expanding Chessman Reservoir and improving the Red Mountain
flume. This selection
Response
A. The comment is noted.
B. The comment is noted. EPA's identification and adoption of the
Chessman upgrade option for additional water storage was in large
part based on the need to find an alternative that would have less
impact on wetlands and wildlife than a new reservoir at the
headwaters of Tenmile Creek.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-25
-------
Comment Letter on Proposed Plan from Jim Posewitz, Orion/the
Hunters Institute - October 24, 2001
contributes to preserving terrestrial wildlife, amphibian and aquatic
values at the alternative Travis Dam site. Thank you for being
responsive to earlier comments on that issue.
C. We support improvement of the Rimini water supply system. This
feature could contribute to increased residential development of the
private lands in Rimini and perhaps it would be appropriate to
consider waste treatment circumstances and options as part of this
package. Recognition of this possibility, if it is relevant, would be
appropriate.
Response
The comment appropriately notes that development of a community
water system may promote residential growth in Rimini and may
therefore indirectly increase the likelihood that Rimini may have to
install a community wastewater treatment facility in the future. Small
lot sizes and inadequate soil conditions may limit the ability of
residents to utilize individual septic systems as the community grows.
EPA has encouraged the establishment of a rural water and sewer
district as it develops its water system. EPA will fund the
construction of the community water system because it is necessary
to provide a source of potable water to replace the groundwater
source contaminated by mining-related releases of hazardous
substances into the Rimini-area aquifers. EPA has also included a
contingency in the remedy for contaminated yard soils whereby EPA
will construct a wastewater collection and treatment system, if
necessary, to replace existing individual septic systems that may be
damaged during the removal of contaminated soils. Many systems in
Rimini may not be replaceable as individual systems in their current
locations because of stringent design criteria currently in place.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-26
-------
Comment Letter on Proposed Plan from Jim Posewitz, Orion/the
Hunters Institute - October 24, 2001
D. Page 2. "Site Background"
Since the 'site' of this project includes 70 abandoned mines scattered
throughout the drainage other resource values in the drainage are
going to be impacted by the cleanup. We believe a description of
those resources and values needs to be included in the site
background and description. Wildlife and recreation throughout the
drainage have become valued public resources. In addition, the site's
relevance to wildlife conservation corridors mentioned in our August
30, 2001 letter to EPA and the USFS should be addressed. The
Tenmile drainage is positioned in a very vulnerable portion of the
wild land habitat corridor connecting the Glacier/ Bob Marshall
complex to wildlands in the Yellowstone area. This geographic
position alone suggests the need to recognize the importance of
retaining, or at least restoring, Tenmile's wildlife habitat security
while cleaning up its toxic legacy. Likewise, as a component of a
continental wildlife corridor the welfare of listed (grizzly, lynx, wolf)
species are necessary considerations.
E. Page 6. "Ecological Risk Assessment"
Comments offered above in the "Site Background" section apply as
well to this section. The network of upgraded access and haul roads
and their future disposition represent a significant ecological risk for
wildlife in Tenmile. The roads likewise represent a potential source
of sediment contamination unless they are obliterated and reclaimed.
It is a risk that this Proposed Plan must acknowledge and deal
Response
D. The comment is noted. EPA recognizes the importance of recreation
and wildlife resources throughout the upper Tenmile Creek
watershed. EPA intends to implement the selected remedy to achieve
remedial action objectives, but to do so in a manner that minimizes
adverse impacts on wildlife and recreational values. For this project,
EPA must balance the need to take action to protect human health
and the environment with potential impacts caused by and the costs
of the actions taken. Wildlife is one, but not the only, resource that
EPA must factor into its evaluation of project benefits and impacts.
Other factors include the fishery and aquatic environment of Tenmile
Creek and its tributaries, groundwater, surface water used as the
source for 70 percent of the City of Helena's potable water supply,
property rights of the owners of private mining claims within the
watershed, various recreational uses (motorized and non-motorized),
and costs that must be borne by EPA, the State of Montana, and local
residents.
E. EPA recognizes that there are potential short-term (during
construction) and long-term risks to wildlife that may result from the
construction and maintenance of access and haul roads necessary to
implement the selected remedy. There is also the potential for
increased sediment loading from the access roads to watershed
streams. EPA intends to address those potential risks during the
remedial design phase of the project, which will occur over a period
of years as detailed plans and specification for the various elements
of the
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-27
-------
Comment Letter on Proposed Plan from Jim Posewitz, Orion/the
Hunters Institute - October 24, 2001
Response
with in the planning process. The roads are real, many already in
place, more to be built or upgraded and no plan seems to be in place
for their final disposition. Likewise, the fate of the private property
assets being upgraded and accessed at public expense should be
addressed. Decisions made as to the future use of these lands could
have lasting ecological impacts that should be acknowledged. It
would seem that the public investment should warrant some
consideration for public values we seek to preserve in this drainage.
selected remedy are prepared. EPA will work closely with USFS,
wildlife resource managers, DEQ, private property owners, and other
interested parties to ensure that wildlife resources are appropriately
considered in the design process. EPA's overall design approach will
be to restrain construction disturbance to the minimum amount
necessary to complete the remedy. Road improvements road width,
tree removal, and the excavation footprint area will be minimized to
the degree possible. EPA's action will attempt to minimize the need
for long-term O&M so that maintenance access roads will be
unnecessary or minimal. EPA will generally reclaim roads to
pre-remedial conditions. However, EPA recognizes that most of the
high-priority mine sites at which action will be taken have relatively
good access at present. One of the key factors in scoring the sites as
high priority was ease of excess, allowing for easy exposure to site
contaminants.
EPA's does not believe that its remedial action will determine the
fate of private property assets and future use of lands within the upper
Tenmile Creek watershed. Superfund is not the proper vehicle for
defining, evaluating, discussing, and deciding future land
management and land use issues. Land and resource management
decisions are appropriately the responsibility of federal land
managers, state wildlife managers, local governmental entities, and
private landowners. Those decisions, requiring extensive public
participation and public comment and considering a wide range of
issues, are beyond the limited scope of Superfund. EPA will
coordinate its actions with those parties to be
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-28
-------
Comment Letter on Proposed Plan from Jim Posewitz, Orion/the
Hunters Institute - October 24, 2001
Response
consistent with current and likely future land management uses and
restrictions.
F. Page 7. "Upper Tenmile Creek Watershed Group"
Item number 4) in this section needs to be expanded to include
'habitat security for resident wildlife and protection of wildlife
conservation corridor connections.' These issues were raised at the
August 23rd Watershed Group meeting by Montana Department of
Fish, Wildlife and Parks, and again during the August 29th field trip
into the area.
Sincerely,
Jim Posewitz
Director At Large
CC
Tom Clifford, USFS
Mike Korn, MDFW&P
The comment is noted. Please refer to the responses to comments D
andE.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-29
-------
Comment Letter on Proposed Plan from Anthony Perpignano •
November 7, 2001
Response
Mike Bishop
U.S. EPA
301 S. Park, Drawer 10096
Helena, Mt 59601
November 7, 2001
Dear Mr. Bishop:
I was very interested by the recent article in the Independent Record on
Saturday, November 3, 2001. As a board member of the Pat Barnes/
Missouri River Chapter of Trout Unlimited and as a concerned citizen of
the Helena Valley, I would like to discuss with you the issue of water in
the lower section of Ten Mile Creek.
I would like to suggest that a water study be done for the section of Ten
Mile Creek from the Blue Cloud area though the valley to its mouth at
the Prickly Pear just south of Lake Helena. I would be willing to gather
the names of several land owners who own water rights on this section of
the creek and work toward seeing if there is a solution that might allow
this beaten down stream to retain water throughout the year. Being
optimistic, I wonder if we could involve several conservation groups like
the Prickly Pear Land Trust, Trout Unlimited, and perhaps some local
organizations that might be interested in "green spaces," such as parks or
conservation easements.
As an architect with an eye toward planning, I see the potential to
maintain and nurture this drainage so that one day, (in the near future) as
the growth expands into the valley, Ten Mile
The comments in this letter are noted. Since EPA's Superfund selected
remedy addresses only the upper Ten Mile Creek watershed, south of
Highway 12 and upgradient of the Helena Tenmile Water Treatment
Plant, the actions suggested in the letter, while valid, can not be
undertaken as part of this EPA Superfund project.
However, EPA's plan to conduct mine site cleanups and increase storage
capacity in Chessman Reservoir to allow for more water to augment the
instream flows in Tenmile Creek should translate to benefits from
improved water quality and increased flow in lower Tenmile Creek
downstream of the Superfund site.
The Lewis and Clark County Water Protection District is in the beginning
stages of developing a watershed improvement program for lower
Tenmile Creek. EPA recommends that Mr. Perpignano contact Mr. Jim
Wilbur at the Water Protection District to obtain more information about
and provide input to the district's plans.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-30
-------
Comment Letter on Proposed Plan from Anthony Perpignano - Response
November 7, 2001
becomes the main back bone to future development. A linear park with
green spaces and conscious development to compliment it s physical
features.
The way I see It, we can take one of two approaches to Ten Mile Creek.
First, and in my opinion the least desirable solution would be to do what
was done in Los Angeles. Ignore the drainage as a migratory route for
Salmonoids and build concrete culverts to control water flow. Build up
around the culverts and forget about it. The second involves less
resources, but a little more imagination, and that would be to work with
land owners, concerned citizen groups, city and county planners and
develop a solution that embraces the creek, while allowing development
to occur throughout the area. This can and has been done successfully,
and as a result, the whole community benefits.
In good water years, I have been fortunate enough to stalk trout in the
early fall only a block away from my house on McHugh Drive. I have
wrestled 16" brown trout and rainbows. After fishing this creek for a
dozen years, I know where the resident fish are. I know the best sections,
and I know the sections to avoid. I can say with some level of confidence
that some of these larger fish are not residents. When there is water in
this creek, the fish migrate through Hauser Lake, into Lake Helena, and
up the Prickly Pear. Some actually make it as far as McHugh Drive and
some push towards Green Meadow.
All I'm saying is that there is potential here, and we won t get a second
chance. I would be very grateful if we could set up a convenient time to
further discuss these issues,
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C - 31
-------
Comment Letter on Proposed Plan from Anthony Perpignano - Response
November 7, 2001
Thank you,
Anthony Perpignano AIA,
Board Member of the Pat Barnes/Missouri River Chapter of Trout
Unlimited
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C - 32
-------
Comment Letter on Proposed Plan from John Rundquist, City of Response
Helena - November 21, 2001
City of Helena
316 N. Park Avenue
Helena, Montana 59623
November 21,2001
Mike Bishop
EPA Project Manager
US Environmental Protection Agency
301 South Park Avenue - Drawer 10096
Helena, Montana 59626
Subject: Proposed Plan Upper Tenmile Creek Mining Area Site
Dear Mike,
Thank you for the opportunity to comment on the proposed plan. We
appreciate that this is the culmination of a huge amount of work and
cooperation between differing interests. As you know, the Ten Mile
Basin is the primary water supply for the City of Helena and has been for
more than 100 years. The City has a major investment in supply, storage
and treatment facilities in the basin and an obligation to preserve and
protect the quantity and quality of water for the benefit of Helena
residents and customers.
A. A historical effect of the City's priority allocation of the basin's water A. The comment is noted. EPA appreciates the City of Helena's
is that lower reaches of the stream below the City's diversion can be cooperation and support of the preferred alternative and of the efforts
nearly dewatered for extended periods during the summer months. by many parties to augment stream flows and improve water quality
This effect is exacerbated by drought when the City has difficulty in Tenmile Creek during seasonal low flow periods. Successful
meeting implementation of the selected remedy will
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C - 33
-------
Comment Letter on Proposed Plan from John Rundquist, City of
Helena - November 21, 2001
demand and stream flows are low anyway. As noted in the plan, the
low flows accumulate toxic levels of mine waste contaminants in the
stream reach below the City's diversion to the detriment offish and
aquatic life.
The Alternative 5, 6 and 7 include provisions for augmentation of
flow in Tenmile Creek. This would be accomplished by increasing
the volume of storage in the City's Chessman Reservoir and by
increasing the delivery of spring runoff water to Chessman with
improvements to the Red Mountain flume. The added volume of
water in City's reservoirs would then be managed to release flow
from Scott Reservoir during seasonal low flow periods. This
approach would both preserve the City's water storage capacity and
provide increased flow in the contaminated reaches of Ten Mile
Creek.
Although there are numerous technical, financial, permitting and
legal issues to work through before the plan can become a reality, the
preferred alternative #5 as well as #6 and #7 are all supported in
concept by the City. We look forward to continuing to work and
support the efforts of the USEPA and Tenmile Creek stakeholders in
advancing the selected alternative.
B. The City is a large landowner in the Tenmile watershed with the
acquisition of the original water supply system and various mining
properties over the years. With respect to the Chessman Reservoir,
the City leases this property from the US Forest Service. A land trade
between the USFS and City
Response
require long-term commitment by the city to manage water releases
from Scott reservoir and allow the released water to bypass the
existing water system intake structure on Tenmile Creek in Rimini.
EPA will work closely with the city and other parties to address the
technical, financial, legal, and permitting issues that must be resolved
to implement that portion of the remedy.
B . The comment is noted. EPA will work closely with USFS and the
city to help facilitate the suggested land exchange.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-34
-------
Comment Letter on Proposed Plan from John Rundquist, City of Response
Helena - November 21, 2001
has been discussed many times to acquire the Chessman site and
flume. Transfer of this property to City ownership with a land
exchange will be integral to the Chessman improvements and will
also help the USFS consolidate land holdings along the Continental
Divide. The City would strongly support the facilitation of this
exchange with the CERCLA process.
Thank you again for the opportunity to comment and for participation in
a potential solution which will improve the health of the watershed and
protect this resource for all stakeholders.
Sincerely,
John Runquist, P.E.
Public Works Director
c: Tim Burton
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C - 35
-------
Comment Letter on Proposed Plan from Diane Tipton - no date
Response
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, MT 59626
Dear Mr. Bishop:
Thank you for the opportunity to comment on the proposed mine waste
clean up alternatives for the Upper Tenmile Watershed. I've bulleted my
comments for the record below.
Expansion of Chessman Reservoir and improvement of the flume
system is an economically feasible solution that is significantly more
environmentally sensitive than other options suggested, in my
opinion. Thank you for listening and making this adjustment.
Town of Rimini needs drinkable water, but I'm glad to see residents
will be the primary ones to decide how it will be done and managed.
Without their full support, involvement and commitment to long-term
maintenance whether that is by actively managing it or simply paying
the bills, it will be a rough road. This is a new level of commitment
and interaction for that community and it isn't clear to me whether
they have the leadership and unity to pull this off, but I remain
hopeful. Since I'm not personally affected, I don't have strong
feelings on this but appreciate EPA's flexibility in trying to assist the
residents.
The comment is noted.
The comment is noted.
Any new roads created or improved to handle the hauling of the mine
waste and reclamation of adit discharges and other
EPA's intent is to improve access roads only to the extent necessary to
conduct its remedial action, and then to reclaim the roads.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-36
-------
Comment Letter on Proposed Plan from Diane Tipton - no date
Response
related work should, I think, be built in the future to the lowest
standard workable, as this project progresses through the next five to
ten years. In addition, all roads impacted by the EPA need to be
reclaimed back to their original width and condition, and/or
eliminated where new roads were created. I'd like a standard similar
to the 1 mile of road per square mile of area recommended by
Montana Fish, Wildlife & Parks to the USFS explored. Roads
shouldn't be built until funds are secured to do the entire job. The
bottom line is that as a resident of this area I don't want to have the
high country opened to further public access by default because EPA
built these roads and didn't reclaim them to their original condition.
Funds to reclaim the roads associated with hauling waste and access
to a particular mine should be factored into the total cost of that
segment of the total work so road reclamation isn't and after thought.
No additional projects or changes in the Upper Tenmile Watershed
should be initiated by the EPA directly or indirectly that increase
recreational opportunities and public access in the Upper Tenmile.
The EPA's job is to focus on the mine waste clean up and the water
quantity and quality issues. Incidental recreational concerns,
increases in recreational access to the area, or other "improvement"
projects are not on the EPA's agenda.
Habitat protection is by default on the EPA agenda. No matter how
the EPA work is handled it will have a significant impact on the
wildlife species in this area. I want to see EPA take every measure
and show every willingness to work with Montana Fish, Wildlife &
Parks, the US Forest
During remedial design, EPA will work with federal and state land and
resource managers, property owners, and other affected parties to
determine detailed access and haul road specifications and plans for road
reclamation.
The comment is noted.
EPA will coordinate closely with federal and state land and wildlife
managers to minimize potential impacts on wildlife.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-37
-------
Comment Letter on Proposed Plan from Diane Tipton - no date
Response
Service and US Fish and Wildlife Service to protect species from the
impacts of this work.
• Wildlife impacts include noise, traffic patterns throughout the gulch,
increased exposure to humans etc. I would like to see FWP work as
an active team member with the EPA in monitoring and proposing
wildlife-friendly alternatives throughout the clean up process and in
assisting in advising and implementing any land deals or other habitat
restoration or preservation that might become necessary or
advantageous as a result of the work being done in the watershed.
• Some of the adit discharges are associated with very small mine
waste dumps in hard to reach areas where reclamation and cleanup
will do more harm to the environment that improvement to water
quality. I would like to see environmentally friendly alternatives
considered for these locations which would not require the building
of new roads or road improvements and which would allow little or
no disturbance in the area. With funding as tight as it is, the projects
in this overall clean up effort should be very carefully prioritized and
the associated environmental disturbance that would result should be
considered as an intrinsic "cost" weighed against any potential
benefit.
Again, thank you for the opportunity to comment.
Diane Tipton
1968 Rimini Road
Helena, Montana 59601
EPA will coordinate with DFWP closely during remedial design to
develop mine-specific cleanup plans that minimize impacts to wildlife.
EPA will evaluate all adit discharges during remedial design. The
evaluation will consider relative contaminant loading to Tenmile Creek
and tributary streams, as well as adverse impacts that would result from
construction and operation of remedial actions. Superfund requirements
for compliance with state surface water quality standards will also be
considered.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-38
-------
Comment Letter on Proposed Plan from R. Mark Wilson, U.S. Fish and
Wildlife Service - November 21, 2001
Response
November 21,2001
Mike Bishop
Remedial Project Manager
U.S. Environmental Protection Agency
301 South Park, Drawer 10096
Helena, MT 59626
Dear Mr. Bishop:
The U.S. Fish and Wildlife Service (Service) has reviewed the document
entitled, "Proposed Plan, Upper Tenmile Creek Mining Area Site, Lewis
and Clark County, Montana" under a technical assistance Interagency
Agreement with EPA. The Service concurs with the selection of
Alternative 5 as the preferred alternative. The implementation of the
preferred alternative will result in significant water quality improvement
and substantial water flows in the Upper Tenmile Creek. I commend
EPA s efforts in successfully addressing this difficult task. In addition,
the Service has the following comments on the document.
A. Chessman Reservoir Expansion
The Service agrees with the proposed plan for enlarging Chessman
Reservoir as a means to increase stream flows in Upper Tenmile
Creek. However, increasing the size of Chessman Reservoir will
inundate at least a portion of a 61.2 acre wetland located on the
southern shore of the Reservoir (see inclosed map). Further, wetland
areas not directly impacted from construction or inundation could be
impacted from hydrologic changes associated with fluctuating water
A. EPA appreciates the comments and suggestions by the USFWS. A
preliminary conceptual drawing showing the revised pool of
Chessman Reservoir can be found in the addendum to the draft RI
and draft FS reports. EPA estimates that the proposed expansion of
Chessman will inundate approximately 15 to 20 acres of current
wetlands. During remedial design, EPA will consult with the USFWS
in determining, wetland losses and establishing appropriate
mitigation approaches and wetland replacement for those
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-39
-------
Comment Letter on Proposed Plan from R. Mark Wilson, U.S. Fish and
Wildlife Service - November 21, 2001
Response
levels, as well as copper sulfate treatment. Once plans for the
Chessman Reservoir expansion have been drafted, potential wetland
loss could be determined. The Service could then calculate wetland
mitigation acres needed based on the Habitat Equivalency (HEA)
model in order to insure compliance with wetland Applicable or
Relevant and Appropriate Requirements (ARARs). Depending on the
mitigation acres needed, Banner Creek wetland could provide a
suitable site for mitigation.
B. Utilization of the HEA model will provide an accurate estimate of the
acres needed for mitigation based on productivity of the natural and
the mitigated wetland. The Service has concerns about mitigating a
high altitude wetland because of the time required for the wetland to
become fully functional under short growing seasons. In the HEA
model, mitigation acreage, the Service recommends that mitigation
be completed prior to the loss of the Chessman Reservoir wetland.
This would reduce the amount of lost wetland services, and thus the
mitigation acreage required. The Service is available to assist with
wetland delineation and evaluation during remedial design.
Thank you for the opportunity to review and comment on the
aforementioned document. The Service looks forward to participating in
the remediation of the Upper Tenmile Creek Mining Area Site and is
ready to assist in the development and implementation of any
post-remedy biological monitoring plans. Should you have any questions
concerning these comments or
B.
loses. EPA agrees that a prime candidate site for wetlands mitigation
would be to improve the impaired wetlands along Banner Creek. EPA
also recommends that EPA and USFWS jointly conduct detailed
evaluation of the current baseline wetlands conditions at both the
Chessman location and the Banner Creek location prior to remedial
design.
In consultation with USFWS, EPA will incorporate wetlands
mitigation into its overall remedial action planning, design, and
construction process. The timing of wetlands mitigation will be
dependent on where and when other site construction activities are
occurring and on funding considerations.
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd
C-40
-------
Comment Letter on Proposed Plan from R. Mark Wilson, U.S. Fish and Response
Wildlife Service - November 21, 2001
require additional information, please contact Ms. Karen Nelson of this
office at (406) 449-5225 extension 210.
Sincerely,
R. Mark Wilson
Montana Field Supervisor
Enclosure
cc: USEPA, R-8, Denver, CO (Attn: Dr. Dan Wall)
Q:\Tenmile\Record of Decision\Final ROD (for real) June 2002\Append C - Respons Summ\C-l\Final ROD C-l.wpd C-41
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest Response
Service - January 7, 2002
Mr. Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Ave., Drawer 10096
Helena, MT 59626
Dear Mike:
This letter is in regards to U.S. EPA-Region VUI's Proposed Plan - Upper
Tenmile Creek Mining Area Site, Lewis and Clark County, Montana. We
appreciate your efforts to continue with substantive water quality
improvements in the Tenmile basin and your efforts to maintain the spirit
cooperation between agencies, interested groups, and landowners. Thank
you for this opportunity to provide our comments. We look forward to
the good work that is still to come.
Our comments are grouped into several sections for clarity which
include: I. General Comments on the Proposed Plan, II. Resource specific
comments on the Proposed Plan; HI. Followup comments to our joint
meeting regarding roads on November 27, 2001; and IV. Identification of
a conceptual process for proceeding with a land exchange between the
City of Helena and the Forest Service to resolve issues regarding
enlargement of Chessman Reservoir.
I. General Comments on the Proposed Plan
We have identified several items in the Plan that will likely occur in
whole or in part on National Forest System lands. These include removal
and disposal of contaminated materials to the Luttrell
Upper Tenmile Creek ROD C-42
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest
Service - January 7, 2002
Response
repository, source controls and treatment facilities of acid mine
drainages, enlargement of the Chessman reservoir, and removal of
contaminated roadway materials. The Chessman reservoir item will be
discussed below. As always, we are looking for solutions that minimize
long term operations and maintenance, minimize potential conflicts with
landowners and Forest Service permits, and retain the inherent character
of National Forest System lands within the framework of meeting
Remedial Action Objectives. At some future juncture, we would like to
have a joint meeting with you as the Remedial Project Manager and
Steve Way, the Removal Project Manager regarding the transition of
duties and responsibilities for the Luttrell Pit Repository and ancillary
facilities.
It is our understanding that the specifics of design and execution of many
of the proposed cleanup items will be done with our followup
involvement through the process identified in the Memorandum of
Understanding (MOU) between the USDA Forest Service, Northern
Region and Environmental Protection Agency Region VIE Regarding
Abandoned Mine Land Response Actions in the Basin, Cataract, Tenmile
and Nearby Watersheds within Jefferson, Powell, and Lewis and Clark
Counties, Montana. I expect the MOU will be signed early in January of
2002. Will you be preparing a Work Plan or similar document that lays
out a proposed overall schedule for completing the items identified in the
Record of Decision? Possibly we could set up an annual joint meeting in
the early fall that identifies the work items to be developed in that year so
that my staff can plan their involvement accordingly. We should also
schedule a joint
EPA will work closely with the USFS during remedial design and
remedial action. An early step in EPA's remedial design process will be
to establish an overall project design and implementation schedule. When
a draft of that schedule is prepared, EPA will provide copies to DEQ, the
USFS, and other involved parties for review and comment. EPA agrees
that meetings every fall, prior to design, and spring, prior to construction,
would be valuable coordination tools. One agenda item for the spring
2002 meeting should be the overall project priorities and schedule. It is
important to note, however, that availability of funding may be a major
determinant in setting the final cleanup schedule.
Upper Tenmile Creek ROD
C-43
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest
Service - January 7, 2002
meeting in early spring prior to the upcoming field season to ensure any
lingering issues are resolved.
II. Resource Specific Comments
The MOU referenced above provides a broad general framework for the
EPA and Forest Service to coordinate actions. The following resource
specific comments are especially applicable on the Helena National
Forest for your consideration during project planning stages.
Heritage
The EPA's acknowledgment in the proposed plan of its historic
preservation obligations under the National Historic Preservation Act is
commendable. The EPA is further commended for completing in 2001 a
baseline analysis of long term preservation and interpretation
opportunities for historic mining ruins in the Rimini Mining District. This
document will be very useful for identifying heritage resources worthy of
protection early in the project specific planning stages. In this regard, we
are interested in closely coordinating with EPA to identify, evaluate and
actively protect significant historic mining ruins or features, particularly
those on or adjoining National Forest land.
We strongly encourage the EPA to develop a Memorandum of
Agreement now with the State Historic Preservation Office (SHPO) and
with the Forest Service as a supporting agency, that clearly identifies the
procedures that will be invoked to facilitate
Response
The comment is noted. EPA will continue to involve USFS staff in
discussions and evaluations regarding historic resources at the site.
EPA intends to pursue development of a memorandum of agreement with
the Montana SHPO. EPA will keep the USFS informed of and involved
in that process.
Upper Tenmile Creek ROD
C-44
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest
Service - January 7, 2002
protection of significant ruins and features during implementation of the
cleanup items in the Record of Decision. We also encourage you to work
with the Forest Service and community of Rimini in developing
interpretive signing for historically significant, but cleanup affected
mining ruins.
Wildlife
As you are aware, wildlife issues have been raised internally and from
members of other agencies and the public. The prominent issues include
road improvements and effects on the connectivity of wildlife habitat as
well as increased future motorized access, and the potential for increased
private land development associated with improvements in the roads
infrastructure, intentionally or otherwise. While these issues normally are
outside the scope of consideration in analyzing remedial actions, we
appreciate your willingness to explore opportunities to respond to them
within the context of the proposed CERCLA actions for the Tenmile. We
are committed to working with you to the extent possible to respond to
these issues in a timely manner to minimize impacts to wildlife and other
National Forest resources in the upper Tenmile watershed.
Recreation
Road restrictions or road closures associated with EPA actions have the
potential to impact recreation opportunities on public land in the Tenmile
watershed. Our management interests also include roads where we may
incur a long term maintenance, custodial or permit management
responsibility. We would like to
Response
The comment is noted.
During remedial design, EPA will work closely with the USFS, USFWS,
DFWP, DEQ, affected property owners, and other interested parties to
develop site-specific access road construction and removal/ reclamation
specifications. EPA's
Upper Tenmile Creek ROD
C-45
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest
Service - January 7, 2002
emphasize our involvement during the planning stages of removal or
remedial projects where roads may be impacted.
Watershed
It is important that as part of the design for individual projects on the
Forest that the desired condition of the mine site be agreed upon. This
includes drainage, vegetation, access, etc. We are interested in pursuing
the development of the desired conditions as part of project planning.
We are interested in being involved in the identification of adit
discharges that will be selected for some kind of treatment system. We
would also like you to consider the discharge from the Paupers pit site at
the head of Monitor Creek for a similar evaluation.
Lands/Roads
As the Proposed Plan has identified, there are approximately 70 priority
mine waste sites that are recommended for removal to the Luttrell
repository. Based on our understanding of the issues associated with
upgrading new roads and potential for private land development, perhaps
there are some sites where onsite, low impact reclamation practices could
be implemented where road improvements and access are not needed. We
are assuming we can explore that possibility during development of the
site specific project plans.
Response
general approach will be to maintain post-remediation road conditions
similar to pre-remediation conditions.
The comment is noted. EPA will work closely with the affected parties to
define desired post-remediation conditions during the remedial design
process.
Last fall, EPA began the initial stage of the ROD-mandated four-phase
approach to addressing acid mine drainage at the site. An inventory of
adit discharges at 37 mine sites was conducted. The inventory included
evaluation of water inflow potential to the mine workings, measurement
of adit discharge flow, and collection of water quality samples. EPA will
provide the USFS and other parties with the draft report when available.
The referenced discharge from the Paupers Pit site is responsibility of
DEQ and has not been included in EPA's analysis.
EPA will evaluate access road needs during remedial design. Based on
information gathered during the RI/FS process, EPA determined that
removal of waste materials and disposal of the wastes at the Luttrell
repository is the most appropriate remedy for the 70 noted sites. A key
factor in that determination was the fact that long-term effectiveness of
the cleanup is enhanced if the wastes are removed to the secure Luttrell
repository. If additional information obtained during remedial design
indicates that other remediation approaches may be more
Upper Tenmile Creek ROD
C-46
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest
Service - January 7, 2002
III. Followup Comments to the Joint Roads Meeting
I appreciate your coordination of the joint roads meeting for the Tenmile
that occurred on November 27th. While we are mostly familiar with the
issues and positions identified, there were some new points brought up
that will be beneficial to our considerations and project specific input to
you regarding roads. As you are aware, there is no more contentious area
of public land management than roads. The private land inholding pattern
and development activity in the Tenmile basin add additional issues and
complexity. The coordination process identified in the MOU should
provide for the Forest Service to be fully involved during planning stages
of individual projects so that any private land permitting, or other
management activities on our part can be accomplished in a timely
fashion.
I would like to briefly reinterate the commitments made by the Forest
Service at that meeting.
1) The Forest Service did not make any site specific road decisions in the
meeting nor did we determine a "one size fits all" solution for any new
road construction that may be needed. However, we will be providing our
input regarding individual new or improved roads, road use permits,
gates, signs etc. during the site specific planning that will occur as
identified in our MOU. Currently I do not plan on initiating the travel
planning process for the overall Tenmile watershed before 2004.
Response
effective, while causing less short-term construction impacts, then EPA
will consider that information at that time. EPA will work closely with
the USFS and other interested parties during remedial design.
The comment is noted. EPA appreciates the efforts of the USFS in
helping to address the issue of access roads and potential impacts on
wildlife resources for this project.
Upper Tenmile Creek ROD
C-47
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest
Service - January 7, 2002
2) We agreed to put together a general picture of the roads and entities
owning/ responsible for them for the Tenmile basin and a description of
the maintenance standard of the road (McKenna).
3) Duane Harp agreed to take the lead with the Tenmile Watershed
Steering Group and others to define a Desired Future Condition for the
watershed.
4) We agreed to work with the other agencies and interested groups
during development of cleanup projects to ensure that project specifics,
including road development, are understood. This also applies to the long
term management implications for Chessman Reservoir with regard to
fish and wildlife.
Response
IV. Land Exchange Process
The City of Helena approached the Helena Forest several years ago
regarding an inter agency land exchange in the Tenmile watershed so that
the city could more efficiently manage its municipal water supply
infrastructure, instead of work through complex and costly permits with
the Forest Service. It also became very apparent during the development
of the Remedial Plan for the Tenmile that the proposed improvements to
the Chessman Reservoir would further complicate the management and
permitting of the City's infrastructure and possibly lead to delays to
implementing EPA's Plan.
In order to facilitate the response action involving the enlargement of
Chessman Reservir, the Regional Forester will make a time critical
CERCLA decision including the exchange of
The comment is noted. EPA appreciates that efforts of the USFS and the
City of Helena in consummating a land exchange that will help facilitate
implementation of EPA's remedial action and
Upper Tenmile Creek ROD
C-48
-------
Comment Letter on Proposed Plan from Tom Clifford, U.S. Forest Response
Service - January 7, 2002
these lands. You have stated that this exchange would be consistent with improvement of water quality and stream flow conditions in Tenmile
the Record of Decision for the Tenmile NPL site. We will be initiating Creek.
our CERCLA action for the exchange early in 2002.
We look forward to working with you on the future cleanup actions in the
Tenmile. If you have any questions or need further clarification regarding
this letter, please contact me at (406) 449-5201 ext. 275 or contact
Helena District Ranger Duane Harp at (406) 449-5490.
Sincerely,
TOM CLIFFORD
Helena Forest Supervisor
Cc: USDA Forest Service-Bob Kirkpatrick, Ray Tesoro, Al
Christophersen, Duane Harp, Kurt Cuneo, Beth Ihle, Carl Davis, Charlie
McKenna, Denise Pengeroth, Brent Costain, Sharlene Larance, Bo Stuart,
Archie Harper, Tom Fox
MDFWP-Mike Korn, Gayle Joslyn, Don Skaar
Montana DEQ-Vic Andersen, Craig French
Jim Posiwitz
Chuck Watters
Montana DNRC- Jesse Aber
Prickly Pear Water Quality Protection District - Jim Wilbur
City of Helena- Tim Burton
Lewis and Clark County Commission
Lewis and Clark County Planning
Upper Tenmile Creek ROD C-49
-------
Draft Proposed Plan Comments and
Responses
-------
Comment Letter from Thomas Clifford to Robert Fox, USEPA - July 20, Response
2001
July 20, 2001
Robert L. Fox, Superfund Program Manager
U.S. Environmental Protection Agency
Region 8, Montana Office
Federal Building, 301 S. Park, Drawer 10096
Helena, MT 59626-0096
Dear Bob:
Thank you for sending us the draft proposed plan for the Upper Ten Mile
Creek Mining Area Superfund Site.
My staff has given the document a preliminary review and thinks the The comment is noted. EPA met with the USFS on November 8, 2001 to
range of alternatives you have identified is adequate and that the discuss USFS comments on the final proposed plan.
proposed plan can be released to the public. Rather than respond with any
questions or comments on the proposed plan at this time, we would like
to arrange a meeting with your staff for that purpose. Please contact
Forest Minerals Geologist Beth Dile (266-3425) or Helena District
Ranger Duane Harp (449-5490) to arrange such a meeting.
I appreciate the high level of coordination and cooperation our two staffs
have shared in the Ten Mile drainage in the past and look forward to
working with you on this new plan.
Sincerely,
THOMAS J. CLIFFORD
Forest Supervisor
Cc: B. Ihle
D. Harp
Upper Tenmile Creek ROD C-51
-------
Comment Letter from Montana Department of Environmental Quality
on Draft Proposed Plan (no date)
Requested changes to the Upper Tenmile Proposed Plan
Earlier comments submitted by DEQ regarding the Feasibility Study have
not been responded to yet. Comments were made requesting references of
successful implementations of biological treatment systems in this part of
the country. Please provide these documents.
DEQ does not wish to determine the method of water treatment before
source control methods have been explored thoroughly. The second and
third bullets under Acid Mine Drainage on page 2 would be a good place
to use language that emphasizes source control. Treatment would not be
considered until after source control methods have been evaluated.
Perhaps these two bullets could be used as replacements:
• Implement those source control methods that demonstrate potential to
reduce the quantity of acid mine drainage on a larger scale.
• Physical/chemical or biological treatment systems will not be
designed and implemented to remove contaminants from any adit
discharges until EPA and DEQ determine water treatment is
necessary and appropriate under Phase 4 of the Reducing Operation
and Maintenance Costs (page 12).
EPA and DEQ will determine what level of water treatment is necessary
as part of the Remedial Design/ Remedial Action phases (see revised text
box "Reducing Long-term Operation and Maintenance Costs," page 12
attached).
Under Groundwater on page two, the second bullet should be:
Response
References to biological treatment systems were provided in the RI/FS
addenda report.
The final proposed plan and the ROD have incorporated the essence of
the requested revisions.
The text of the final proposed plan was clarified to emphasize flow
reduction.
Upper Tenmile Creek ROD
C-52
-------
Comment Letter from Montana Department of Environmental Quality
on Draft Proposed Plan (no date)
• Source control actions for waste rock and tailings and acid mine
drainage would be expected to reduce groundwater^/7ow and
contaminant levels over time.
Response
EPA considers source control to include all surface and subsurface
actions to reduce both contaminant loading and discharge flow rates.
Under Surface Water on page two, the bullet should be rewritten as:
• Source control actions such as run-on and run-off storm water controls
and grouting, for waste rock and tailings and acid mine drainage, ...
Under Stream Sediments on page two, replace the word "with" in "with
disposal at the Luttrell Repository." to^br.
Page 5, the second column, first sentence under Ecological Risk
Assessment, define COCs. Page 9, the second column, the first
paragraph, Add this phrase to the end of the third sentence: and minimize
infiltration.
Page 9, the second column, in the second paragraph, replace "remedy"
with remediate in the fourth sentence and replace "Accomplish major
reduction of " with significantly reduce in the fifth sentence.
Page 10, the second paragraph under Alternative 3, the third sentence,
replace "comply" with result in compliance.
On page 10 where Alternative 4 is discussed, DEQ recommends
removing the references of ADS and AD4 throughout the discussion and
replacing those with references to the revised
Editorial corrections were made in the final proposed plan consistent with
the comments noted.
In the final proposed plan and ROD, EPA has identified and included a
new alternative AD4/5 to incorporate the four-phase approach for
remediating acid mine drainage. The approach,
Upper Tenmile Creek ROD
C-53
-------
Comment Letter from Montana Department of Environmental Quality
on Draft Proposed Plan (no date)
Response
O&M reduction discussion on page 12. Alternative 4's narrative could be
revised to reflect DEQ's suggested approach as follows:
Alternative 4
PREFERRED ALTERNATIVE
Remove mine wastes to Luttrell for category C, D, and E sites (WR4) and
no action for category A and B sites (WR1); water inflow reduction at all
mines with adit discharges, follow the four phase plan that leads to
determining the best method of controlling acid drainage (AD?);
implement groundwater use controls (GW3); remove contaminated
residential yards (RY3); remove contaminated roadways (RD3); no
action for surface water (SW1); and stream sediments (SD1).
Alternative 4 is EPA's preferred alternative. It would provide a protective
remedy for mine waste/tailings by excavating and hauling to the Luttrell
repository mine wastes from category C, D, and E sites. Efforts would be
implemented to reduce inflow of water into mine workings at all sites to
reduce the production of acid mine drainage. Source control methods will
be evaluated according to the four-phased plan on page 12 before
physical/chemical water treatment methods will be considered.
There are no changes in second paragraph.
Alternative 4 would provide a protective remedy, relative to mine waste/
tailings, that would be effective in both the long and short-term. It would
effectively isolate the most significant waste piles at the site (wastes at
category C, D, and E sites) by placing
developed in consultation with DEQ, contains the essential elements of
DEQ's comments here, primarily that all appropriate efforts for flow
reduction be taken prior to implementation of adit discharge treatment
components, in order to minimize long-term O&M costs for treatment.
EPA has agreed with that approach. EPA does not believe that all loading
from AMD can be addressed by source control and flow reduction alone.
Current data indicate that some treatment of AMD will be required to
meet state ambient water quality standards. The ROD recogizes that some
treatment of residual adit discharge flows will be necessary and treatment
costs are factored into the remedy cost estimates.
Upper Tenmile Creek ROD
C-54
-------
Comment Letter from Montana Department of Environmental Quality
on Draft Proposed Plan (no date)
them in a lined regional repository with effective leachate control and
monitoring. Contaminated streams...
Page 12, Table 2, Comparison of Alternative Number of Sites and Flow
Rates of Acid Mine Drainage, should be removed since the form of water
treatment will not be determined until the four phased O&M reduction
plan reaches that point.
Please replace the text in the text box on page 12 with the following
language:
Reducing Long- term Operations and Maintenance Costs
EPA is committed to implementing a comprehensive cleanup of mine
waste sources so that long-term operation and maintenance (O&M)
needs can be minimized The State of Montana is responsible for the costs
of all long-term O&M of the completed remedy The primary remedy
feature that may entail considerable O&M costs is the long-term
treatment of acid mine drainage from the mine adits. EPA andDEQ will
evaluate and implement the remedy for acid mine drainage in a
four-phased approach. The first phase will consist of overall assessment
of the potential to achieve remedial objectives and significant O&M cost
savings through source controls to reduce the volume of acid mine
drainage from individual mines. The second phase will include detailed
design investigations and pilot studies at certain mine sites to
demonstrate source control techniques. Taking into consideration the
information generated from the investigations and studies, and, after
evaluating the net effect of source removal(s) upon water quality, the
third phase would include full-scale implementation of source control
measures at specific mine sites. If EPA andDEQ agree that water
Response
EPA incorporated the substance of the recommended changes into the
final proposed plan and ROD.
Upper Tenmile Creek ROD
C-55
-------
Comment Letter from Montana Department of Environmental Quality Response
on Draft Proposed Plan (no date)
treatment facilities are required to remove contaminants from the
residual adit discharge flows, EPA will design and implement
construction of water treatment facilities necessary and appropriate to
meet remedial objectives in the final phase.
I. Phase 1-Remedial Design
• Investigate mine maps, records and geology of specific mine
workings
• Evaluate and map potential surface water inflows to mine workings
• Identify mine sites where flow reduction or other source control
techniques could be potentially successful
• Conduct sampling and tracer studies to determine water inflow and
contaminant release locations
II. Phase 2- Remedial Design
• Open portals and adits where possible to gain access to mine
workings
• Conduct additional detailed sampling and tracer studies if necessary
• Conduct pilot studies of flow reduction, segregation, grouting, mine
plugging, or other source control techniques
III. Phase 3-Remedial Action
• Implement full-scale source removal and source control actions at
mine sites where necessary
• Continue to monitor success of source control actions
IV. Phase 4- Remedial DesignlRemedial Action
• Begin design and construction of facilities to treat residual adit
discharge where EPA and DEQ agree a treatment facility is (or
treatment facilities are) necessary and appropriate
Upper Tenmile Creek ROD C-56
-------
Comment Letter from Montana Department of Environmental Quality
on Draft Proposed Plan (no date)
EPA will begin the adit flow reduction effort at the beginning of remedial
design It is anticipated that two years of investigation, design and
evaluation of source control techniques would be required prior to
implementing a full-scale source control action for the Site. Evaluation of
water treatment options would begin in the third year. EPA will conduct
all phases of the design and implementation of the appropriate source
control measures, as well as any water treatment facilities necessary and
appropriate to remove contaminants from the residual adit discharges, in
full consultation with DEQ.
Please explain each of the O&M categories in Table 3 with more detail.
Where do these numbers come from? What is the Waste Rock/Tailings
cost? Please provide the number crunching used to estimate the Luttrell
Repository O&M cost.
Please include DEQ's share of the estimated O&M costs of the preferred
Rimini Community Water System Alternative with the total O&M costs
for the site.
Page 18, the second line from the top, "mining related" should be
mining-related.
Page 18, number 3, the last sentence should be rewritten as: Should an
alternative with such high operation and maintenance be implemented?
Response
Detailed cost estimates have been included in the RI/FS addenda report.
The O&M costs for the Rimini community water system would be borne
by the users of the system, not DEQ.
Upper Tenmile Creek ROD
C-57
-------
Comment Letter from Stan Fraiser on Draft Proposed Plan - August 2, Response
2001
August 2, 2001
Mike Bishop, Administrator
U.S. Environmental Protection Agency
301 South Park Rm 192
Helena, MT 59626
Dear Mr. Bishop,
The Helena Hunters and Anglers Association would like to express its
interest in preserving the wild land character of the Ten Mile Creek
watershed while supporting the goal of improving the stream's water
quality and reclaiming associated mine sites in the watershed. The
Association's Board of Directors met on July 31, 2001 and approved of
expressing our organization's concern in the enclosed resolution.
Our concern is presently focused on maintaining critical wildlife
wetlands in the watershed along with preserving backcountry hunting
opportunity. In addition, we believe the issue of maintaining wildlife
corridors between associated wild lands in the Northern Rockies is a
valid biological concern. All of these issues are relative to the Ten Mile
Watershed project and we believe, with the proper attention in planning,
they can all be retained and possibly be enhanced.
Please take time to consider our resolution and we would appreciate
being included in the review of alternatives being considered in this
watershed.
Upper Tenmile Creek ROD C-58
-------
Comment Letter from Stan Fraiser on Draft Proposed Plan - August 2, Response
2001
Sincerely,
Stan Frasier
President
THE HELENA HUNTERS AND ANGLERS ASSOCIATION
RESOLUTION #2
TEN MILE WATERSHED PROJECT
Whereas: The Ten Mile Creek watershed is a key resource supporting
multiple uses of public forest lands including fish, wildlife, and the
drinking water supply of the Helena community, and
Whereas: Helena Hunters and Anglers endorse the efforts of the Ten
Mile Watershed Group to protect and restore the integrity of the
watershed including resolving stream flow depletion problems and
addressing abandoned mine impacts, and
Whereas: The Ten Mile Creek Watershed has long supported dispersed
hunting recreation for animals secure in defacto wildlands, and
Whereas: International conservation efforts are working to maintain
wildlife habitat corridors between the wild lands of the Northern Rockies
and the Greater Yellowstone Ecosystem. In this context, the relatively
remote areas of the headwaters of Ten
Upper Tenmile Creek ROD C-59
-------
Comment Letter from Stan Fraiser on Draft Proposed Plan - August 2,
2001
Mile Creek watershed are now or are expected to be habitat for the
natural expansion of grizzly bears extending their range south from the
Bob Marshall Wilderness complex, and
Whereas: The wetlands of the headwaters of Ten-Mile Creek are a
critical habitat type for elk, moose, bear and a variety of other species of
birds and mammals.
Now therefore be it resolved: The Helena Hunters and Anglers
Association, while supporting these reclamation efforts, urge the Ten
Mile Watershed Group to explore alternatives to the creation of a
reservoir that minimize wildlife impacts, and
Be it further resolved: That hunters and anglers be included in the
planning process for the reclamation of this watershed.
ADOPTED BY THE HELENA HUNTERS AND ANGLERS
ASSOCIATION
Response
In response to public comment, EPA has rejected the alternative of
constructing a reservoir at the Travis location to avoid potential wetlands
and wildlife impacts. Additional water storage capacity will be obtained
by upgrading Chessman Reservoir.
The Helena Hunters and Anglers have been invited by EPA to participate
in the ongoing facilitated discussions regarding wildlife issues and access
roads necessary for the Superfund cleanup.
Upper Tenmile Creek ROD
C-60
-------
Comment Letter from Michael Korn on Draft Proposed Plan - Response
September 25, 2001
September 25, 2001
930 Custer Avenue W
Helena, MT 59620-0701
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, MT 59626
Tom Clifford, Supervisor
Helena National Forest
2880 Skyway Drive
Helena, MT 59602
Janette Kaiser, Supervisor
Beaverhead-Deerlodge NF
420 Barrett Street
Dillon, MT 59725-3572
Dear Mr. Bishop, Supervisor Clifford, and Supervisor Kaiser:
Montana Fish, Wildlife and Parks appreciates that the EPA and The reservoir considered for upper Tenmile Creek was not included in
participating agencies / organizations have agreed to reconsider EPA's selected remedy.
construction of a reservoir in the meadows of upper Tenmile Creek. This
area is virtually irreplaceable wet meadow habitat that is of vital
importance to wildlife of the drainage.
We remain concerned, however, about road development and upgrades
for the purpose of hauling toxic mine waste. While we recognize the
practical necessity of hauling the materials and
Upper Tenmile Creek ROD C-61
-------
Comment Letter from Michael Korn on Draft Proposed Plan -
September 25, 2001
Response
thus, roads on which to haul must exist, we must stress the importance
of wildlife habitat that is being compromised in the process of the
Super Fund cleanup. The cleanup is currently taking place in the
Tenmile drainage (Helena National Forest) and is about to begin on the
Occidental Plateau and other sites within the Boulder River drainage
(Helena National Forest and Beaverhead-Deerlodge National Forest).
I have included with this correspondence a memo and a letter from the
Fish, Wildlife and Parks wildlife biologist for this area itemizing a
variety of wildlife concerns that have arisen as a result of the clean up
procedure.
While we certainly agree that toxic mine waste must be cleaned up, we
also believe that part of the cost of that clean up lies in reclaiming
impacts that have resulted from the clean up. One of the unavoidable
results of the cleanup will be improved roads, and even though the plan
is to return some of the roads to their original width, the standard of
those roads will certainly be improved compared to their pre-haul
condition. This improvement to road standard translates into more
human usage and greater wildlife habitat fragmentation. We would
urge that a road density of 1 mile of road per square mile be adopted by
the Forest Service to compensate for improved road standards and
increased traffic.
We are also quite concerned about the plan to develop a high standard,
30 foot, 6.1 mile paved highway (proposed as Montana Forest Highway
Route 98) beginning at Highway 12 and "...ending at Chessman
Reservoir intersection, just north of the
EPA has committed to reclaiming or removing roads to the pre-removal
conditions to the extent practicable. During remedial design, road
construction and reclamation/ removal specifications for each mine site
will be developed by EPA in consultation with federal and state land
and wildlife resource management agencies, affected property owners,
and other interested parties.
The proposed paving of Montana Forest Highway Route 98 is being
considered by the Federal Highway Administration and has nothing to
do with the EPA Superfund project.
Upper Tenmile Creek ROD
C-62
-------
Comment Letter from Michael Korn on Draft Proposed Plan -
September 25, 2001
Response
community of Rimini." We have reason to believe that certain species
of wildlife have been displaced from their normal movement corridor
along the Continental Divide and are using the country between a point
on the Continental Divide roughly at Jericho Mountain in a
southeasterly direction through the Black Mountain Roadless Area
(Beaver Creek drainage), through the Chessman Reservoir-Park Lake
area onward to the Occidental Plateau and the Boulder Divide, and then
to the Elkhorn Mountains. Thus, a highway ending at Beaver Creek
would clearly draw traffic into making the loop route from Tenmile
Creek up Beaver Creek, and over to Park Lake and back to Interstate
15. However, because Beaver Creek acts as a conduit for wildlife, the
existing low standard, rough road should remain as it is, or even
removed.
In addressing these issues we urge you to:
• Commit EPA funding for the cost of reclaiming roads associated
with clean up, factoring in increased traffic as a result of higher
standard roads as soon as the project is completed;
• If Route 98 is constructed, build to a lower standard, using chip
sealing and wildlife crossings;
• Avoid upgrading any additional roads unless those roads are
removed and reclaimed post cleanup, in particular the Beaver Creek
road (between Red Mountain and Black Mountain);
• Remove other roads that compromise the proposed new standard of
1 mile of road per square mile;
• Commit to the cost of intense enforcement of off-road vehicle use
of the clean up areas for at least 5 years.
Reclamation/ removal of access roads will be part of EPA's remedial
action and will be funded the same as other remedy components.
Improvements to Rimini Road north or the Chessman Road (Route 98)
are not part of EPA's action.
Specifications for particular access roads will be determined during
remedial design.
EPA can not be responsible for reclaiming/ removing roads other than
those used to access mine sites for cleanup purposes. EPA can not fund
land management enforcement activities, since these appropriately are
the responsibility of other agencies.
Upper Tenmile Creek ROD
C-63
-------
Comment Letter from Michael Korn on Draft Proposed Plan - Response
September 25, 2001
We are willing to participate and provide wildlife habitat expertise for EPA appreciates the consultative support of DFWP in this project.
the duration of the clean up process. Because the process is well
underway and moving rapidly, we request written correspondence in a
timely manner relative to the points raised here.
Again, thank you for considering wildlife in you re evaluation of the
reservoir, and we look forward to helping to minimize wildlife habitat
fragmentation in this project.
Sincerely,
Michael Korn
Helena Area Coordinator
c: Pat Flowers, Supervisor FWP Region 3
Mack Long, Supervisor, FWP Region 2
Upper Tenmile Creek ROD C-64
-------
Comment Letter from Gayle Joslin to Mike Korn - September 4, 2001 Response
TO: Mike Korn DATE: September 4,2001
FROM: Gayle Joslin
UPPER TENMILE WATERSHED TOUR
August 29, 2001
The Helena Ranger District and the Environmental Protection Agency
hosted a tour of the mine waste clean up project for approximately 20
individuals from the City of Helena (water treatment and planning),
Lewis and Clark County (commissioners and planners), local residents,
the Helena Hunters and Anglers Association, and Montana Fish,
Wildlife & Parks. Several photos were taken.
There are approximately 150 mine sites in the area, 70 of which will be
cleaned up. Toxic mine waste clean up is viewed as a positive step.
However, from a wildlife habitat and population perspective the
following points are problematic:
• This project has been underway for about 2 years. The Tenmile
Watershed group has been meeting for about 4 years.
• Wildlife was not considered in the planning process of this project.
• High standard roads have been and will continue to be built to
accommodate hauling of mine waste.
• Once the cleanup has been completed in the Upper Tenmile
watershed, the project will move into the Upper Little Blackfoot
and the Cataract Meadows areas - both very important wildlife
areas.
• The Continental Divide Wildlife Corridor has been severely
Upper Tenmile Creek ROD C-65
-------
Comment Letter from Gayle Joslin to Mike Korn - September 4, 2001
Response
compromised, and may not be functioning for wildlife movement in
the vicinity of the defunct Pegasus Mine and the Luttrell Pit mine
waste repository. This area now has the appearance of an industrial
site.
If road systems are to be removed, reduced or reclaimed, then
funding through the EPA process must be factored into the cost of
their removal as part of this project. The Helena District Ranger
indicated that the Forest Service intends to address these newly
created, high-standard roads "in the future" during the Roads
Analysis process, or even later in the Watershed Management plans
(up coming is the Little Blackfoot). The Roads Analysis process
will NOT address anything smaller than system roads (OHV routes
and old pioneered roads will not be addressed). Funding must be
secured now, to remove the roads that are being created from this
EPA project and are compromising wildlife habitat (habitat
effectiveness, security).
A Cumulative Effects analysis addressing wildlife, habitat, and
security must be prepared with respect to the cleanup project, and
must be factored in as a part of the project - probably a task to be
undertaken by the Forest Service. This analysis will reveal needed
accommodations to retain wildlife habitat (road and area closures).
A 30' wide highway is planned for construction up the Tenmile
drainage, which will end just short of the town of Rimini, at the
Beaver Creek road.
FWP has systematically opposed upgrading the Beaver Creek road
in order to minimize habitat fragmentation for wildlife.
Many of the mine sites that are being cleaned up are in the Black
Mountain Roadless Area, which are accessed by the Beaver Creek
road.
EPA will be responsible for and will fund reclaiming/ removing roads
that it has constructed or improved for access for its cleanup actions to
the extent practicable. The comment appears to imply that EPA should
be responsible for other roads in the road system, such as OHV routes
and old pioneered roads). EPA can not be responsible for reclaiming or
removing roads that it did not use in its cleanup.
A cumulative effects evaluation may be useful or necessary in making
land management decisions, but is not required in a Superfund ROD.
EPA will continue to consult with resource managers, land owners, and
interested parties in considering wildlife issues during remedial design.
The proposed highway is not part of EPA's action.
The comment is noted.
The only site in the Black Mountain Roadless Area proposed for
cleanup is the Upper Valley Forge; cleanup there is complete except for
potential additional actions addressing the adit
Upper Tenmile Creek ROD
C-66
-------
Comment Letter from Gayle Joslin to Mike Korn - September 4, 2001
Response
The issue of Potentially Responsible Parties (PRPs) has not been
resolved, yet roads are being upgraded to these properties for
cleanup.
There are 18 mine waste dumps in the Black Mountain Roadless
Area. Adit discharges are also an issue. They are burying the adits
(photo). The FS says that roads must remain to private lands even if
they are PRPs. Weed control will occur for 4-5 years (then what?).
Several of these mine sites will retain the upgraded road to private
lands, thus creating a collective additional impact from the cleanup
process. In addition, leveled "staging" areas that are now being
used for the clean up will remain for the use of the landowner -
convenient and accessible home sites. Pressure will be brought to
bear by these landowners to upgrade the Beaver Creek road.
Instead of being able to use the Continental Divide as a movement
corridor due to the development of 15' wide haul roads and the
industrial complex on the crest of the divide between Tenmile
Creek and Basin Creek, wildlife are most likely to use (and
apparently are using) an alternative corridor from Jericho
Mountain, across Tenmile Creek, through the Black Mountain
Roadless area, into the Chessman Reservoir-Park Lake country and
on to the Occidental Plateau and the Boulder Divide. From the
Boulder Divide, the Elkhorns likely become the conduit for
movement for grizzly bears (12 reports in my data base along the
Continental Divide), wolverine, wolves, and other wide-ranging
species, as well as serving as seasonal home ranges for big game
species (elk, moose, deer).
There will be a push to up-grade the Beaver Creek road. This
discharges.
EPA has conducted initial PRP searches and has not identified viable
PRP's for the site. Road improvements have been necessary for cleanup
irrespective of PRP status.
The referenced waste dumps were at the Upper Valley Forge site. Weed
control actions will continue as part of site O&M until no longer
necessary.
Most of the access roads at the Upper Valley Forge site have been
completely removed. Staging areas for construction support were
reclaimed similar to pre-construction conditions.
The comment is noted.
The comment is noted.
Upper Tenmile Creek ROD
C-67
-------
Comment Letter from Gayle Joslin to Mike Korn - September 4, 2001
Response
must be resisted in order to retain what connection still remains to
mountain range movement corridors to the east of the Continental
Divide and toward the Yellowstone Ecosystem. Mine waste hauling
work in this area will end in October 2001 theoretically.
• Discussion of where to build a reservoir to re-water Tenmile Creek
continues. During the tour we viewed the Banner Creek site,
adjacent to where the haul road already exists on its way to the
Luttrell Pit. The Peerless, Jenny and King adits are currently
bleeding into Banner Creek. The cost would be $6 million to build
the Banner Creek site vs. $4 for the Travis Reservoir site, or $4 to
upgrade Chessman Reservoir.
• The issue is: The Forest Service took the EPA money to upgrade
roads, but will not have any EPA money to reclaim or
decommission roads in the future unless they act now.
• Preference seems to be to upgrade the existing Chessman Reservoir
rather than build a new reservoir, although efforts must be taken to
assure that the Beaver Creek road will not be upgraded between
Tenmile and Chessman.
• When asked whether a Wildlife Report of any kind exists for this
project, Mr. Bishop indicated he didn't think so. I have not been
able to find one. I called Brent Costain at the Helena Ranger
District and learned that he has not yet written a wildlife report but
thinks that perhaps the time is ripe.
• Mr. Bishop contends that FWP has had representation in the form
of fisheries. I content that this was not Wildlife representation.
Clear correspondence should be written to both the Helena National
Forest and the Beaverhead-Deerlodge National Forest
The selected remedy will upgrade Chessman Reservoir.
USFS Superfund removal actions have been conducted with USFS
funding. EPA did not provide funding to USFS for road improvements.
The comment is noted.
Preparation of a wildlife report or inventory is beyond the scope of
Superfund.
EPA provided reports to and kept the DFWP representative informed
about all aspects of the ongoing Superfund project.
Upper Tenmile Creek ROD
C-68
-------
Comment Letter from Gayle Joslin to Mike Korn - September 4, 2001 Response
asking that MFWP wildlife concerns be addressed immediately, and
prior to the onset of any further mine cleanup.
Upper Tenmile Creek ROD C-69
-------
Comment Letter from Gayle Joslin to Duane Harp, USFS - August 20, Response
2001
August 20, 2001
Duane Harp, District Ranger
Helena Ranger District
2001 Poplar Street
Helena, MT 59601
Dear Ranger Harp:
I am following up on our conversation of August 17 regarding the
reconstructed road that circumscribes the Tenmile watershed, along the
ridgeline of the Continental Divide from Bullion Parks to the Basin
Creek mine.
During our discussion you indicated that the decision process followed
a format other than NEPA. Please provide reference to that process,
along with guidelines that address wildlife. I would appreciate
receiving a copy of the decision document that authorized this road,
along with analysis of impacts to natural resources -1 am particularly
interested in the discussion regarding wildlife and whether mitigation
features were factored into the decision and whether a BE was done.
The road certainly is an imposing presence, and has changed the
character of the Continental Divide from Minnehaha Creek to the
headwaters of Basin Creek.
This road opens the door to significant motorized usage during all
seasons of the year, and will have a significant impact upon the
integrity of wildlife habitat. The Continental Divide is a nationally
recognized wildlife movement corridor, and provides habitat to some of
the most esteemed and rare wildlife in North
The comment is noted. The improvements to the road along the
Continental Divide to the Luttrell repository were made under USFS
Superfund authorities. EPA will need to utilize that road for cleaning
up mine sites in the Minnehaha Creek subarea for which EPA has
responsibility. EPA will work with the land and resource management
agencies, property owners, and other interested parties to determine the
final disposition of that road.
Upper Tenmile Creek ROD
C-70
-------
Comment Letter from Gayle Joslin to Duane Harp, USFS - August 20, Response
2001
America, including lynx and grizzly bears.
If in fact there are no reclamation or mitigation measures associated
with the decision notice that authorized this road, it is recommended
that once the road has served its purpose, that it be removed from the
Continental Divide to restore wildlife security and habitat integrity that
has historically been present in this fragile, high elevation environment.
Please consider these comments in your Roads Analysis.
Thank you.
Sincerely,
Gayle Joslin
Helena Area Resource Office
Wildlife Biologist
c: Joel Peterson
Mike Korn
Upper Tenmile Creek ROD C-71
-------
Comment Letter from Gayle Joslin to Mike Bishop - July 26, 2001
Response
July 26, 2001
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, Montana 59626
Dear Mr. Bishop:
I was pleased to be able to attend a field tour this week (July 25) of the
wet meadow-marshes in T8N R6W SW 13 where a reservoir is
proposed in 3 of the alternatives listed in the Draft Proposed Plan for
the Upper Tenmile Creek Mining Area. Enclosed please find a series of
photos that I took with my digital camera. While the quality leaves a bit
to be desired, the nature of the meadows is at least partially captured.
Although I have flown over the area many times in the last two
decades, this was the first time I had been to the site on the ground. I
was immensely impressed with the productivity and vegetative
diversity of the area. The meadows are wet, deep sponge carpets of
grasses, sedges and forbs, with a couple of beaver ponds near the
center. Importance of the site for wildlife was evident with elk beds
throughout and abundant droppings of elk, moose, deer, and bear.
The site is less than one-half mile from the Continental Divide, which
is recognized as a critical wildlife movement corridor through the state,
between ecosystems. In the past 7-8 years, reports of grizzly bear have
increased in the area from MacDonald Pass to Boulder Hill, with a
female grizzly and offspring reported in this area in the past three years.
The most extensive use of this area is made by elk, with the Upper
Tenmile
The descriptive comments provided in the letter are noted. No response
is necessary.
Upper Tenmile Creek ROD
C-72
-------
Comment Letter from Gayle Joslin to Mike Bishop - July 26, 2001 Response
watershed providing crucial high nutrition summer range for several elk
herds. Elk that winter in several dispersed wintering areas converge in
the upper Tenmile Creek area to calve, and spend summer and fall,
regaining body condition subsequent to the demands of winter,
pregnancy, birthing, and lactation. Although somewhat diminished over
the past 10 years with improved access to the Basin Creek mine and
now transportation upgrades for Superfund cleanup, security for big
game in this area has been excellent, and thus the area has been
instrumental in providing secure habitat for big game during the fall
hunting season. Upper Tenmile Creek is the largest area of relatively
undisturbed wildlife habitat within Hunting District 335. As security
diminishes, hunting seasons also decline, resulting in increased
restrictions and ultimately reduced hunting opportunities. The wet
meadows in upper Tenmile that are proposed for inundation, support
distinct wintering elk herds from lower Tenmile Creek along the Mount
Helena - Black Mountain Ridge, the Little Blackfoot, upper Basin
Creek, and the Lump Gulch drainages of Prickly Pear Creek.
Moose reside throughout the meadow area, and may be able to utilize
this high, wet basin yearlong, at least during winters with lower
precipitation. Utilization by moose as well as other big game is
probably continuous for 75% of the year, during the period April
through December.
Threatened, endangered or sensitive species likely to occur in the
area include grizzly bear, gray wolf, lynx, wolverine, Northern
goshawk, and Northern bog lemming. The lynx was recently listed as a
threatened species under the Endangered Species Act,
Upper Tenmile Creek ROD C-73
-------
Comment Letter from Gayle Joslin to Mike Bishop - July 26, 2001
Response
and the extent of their habitat includes the Continental Divide and
upper Tenmile Creek area.
The expanded and upgraded tailings haul road that partially
circumscribes the headwaters of Tenmile Creek from the top of
Minnehaha Creek south and east to the Luttrell pit, will not only
experience a high level of use compared to its pre-upgraded status, but
will continue to provide motorized disturbance down the center of one
of the most important wildlife travel corridor in North America: the
Continental Divide; unless of course, the Helena National Forest
determines that this road is in a crucial location and should ultimately
be removed.
The road, together with flooding of the wet meadows in Sections 13
and 14 would be a certain impact upon a wide variety of wildlife, not
only for the Tenmile watershed, but also for wildlife of upper Basin
Creek, the northern reaches of the Little Blackfoot south of Highway
12, and for wildlife using the headwaters of Prickly Pear Creek.
How and where would these wetlands that are proposed for inundation,
be replaced with wetlands of similar quality and quantity? I am quite
familiar with the greater Helena area, being a native of Helena and
having worked as a biologist here for the past 16 years, but I cannot
recall a potential wetland site of equal extent and quality in this area,
that has not been severely disturbed.
If other alternatives can be devised that would not rely on flooding the
wet meadows of the Tenmile drainage, wildlife habitat and intrinsic
values would be maintained to a
The selected remedy includes the upgrade of existing Chessman
Reservoir to achieve additional water storage for flow augmentation in
Tenmile Creek, rather than construction of a
Upper Tenmile Creek ROD
C-74
-------
Comment Letter from Gayle Joslin to Mike Bishop - July 26, 2001 Response
substantially greater degree. If the options that include reservoir new reservoir. That change from the draft proposed plan was made to
construction are considered in the final proposal, wildlife populations address concerns over impacts on wetlands and wildlife at the potential
and habitats need to be thoroughly analyzed as a trade-off. Travis Reservoir location.
Thank you for this opportunity to comment, and please do not hesitate
to call if you have questions.
Sincerely,
Gayle Joslin
Wildlife Biologist
Helena Area Resource Office
444-4720
cc: Duane Harp, Helena Ranger District
John Rundquist, Public Work Director City County Building
Don Skaar, Pollution Control Biologist, FWP
Jesse Aber, Tenmile Watershed Group, DNRC
Karen Nelson, Toxicologist, FWS, Liason to Superfund Project
Joel Peterson, Wildlife Manager Region 3, FWP
Mike Korn, Resource Program Manager, Helena Area Resource
Office, FWP
Upper Tenmile Creek ROD C-75
-------
Comment Letter from Chuck Parrett on Draft Proposed Plan - July 9,
2001
Response
July 9, 2001
Mike Bishop, Remedial Project Manager
EPA
310 S. Park, Room 192
Helena, Montana 59626
Dear Mike,
I am writing in response to the DRAFT proposed plan for cleanup of
the Upper Tenmile Creek watershed. My comments represent my
personal opinions only and should not be considered as any kind of
official position or opinion of my employer, the U.S. Geological
Survey. As you know, I am a landowner in the Upper Tenmile Creek
Watershed, and I welcome efforts by the EPA to mitigate water-quality
problems in the Tenmile Creek watershed. I do, however, question
whether the proposed plan, particularly the preferred alternative 4, is
the most efficient and cost-effective way to take care of the problem.
The bulk of the work outlined in preferred alternative 4 is the removal
of mine waste rock and tailings to the Luttrell Pit. As evidenced by the
clean-up activities so far undertaken, this requires a substantial amount
of new road work or substantial upgrades to existing roads. This kind of
massive road work has its own environmental and social cost, and I
question whether the long-term benefits of clean-up of the 70 or so
additional mine sites proposed in alternative 4 will outweigh those
environmental and social costs. While I strongly support the removal of
mine waste from the sites that provide the greatest
The comment is noted. Based on its site scoring and ranking process,
EPA believes that numerous mine sites still exist that have potential to
significantly degrade Tenmile Creek and its tributaries. While the
continual loading and impact from key adit discharges in the Rimini
area are the most important sources to Tenmile Creek, EPA remains
concerned about intermittent loading from waste material erosion
during storm and runoff events. EPA has tried to concentrate its efforts
on those mine sites that are located nearest to and present the greatest
risk to Tenmile Creek. EPA has strived to develop a balanced remedy
Upper Tenmile Creek ROD
C-76
-------
Comment Letter from Chuck Parrett on Draft Proposed Plan - July 9,
2001
Response
threat to Tenmile Creek, it seems to me that clean-up efforts already
underway will largely take care of the problem sites.
I believe that the greatest contributors of contamination to Tenmile
Creek are the mine adit discharges just above Rimini and within
Rimini. Treatment of those adit discharges will do far more to improve
water quality than removal of all waste rock piles, I suspect.
Finally, one very significant aspect of impaired water quality in
Tenmile Creek that alternative 4 does not address is the dewatering of
the mainstem by withdrawals for municipal water supply. As you
know, complete cleanup of all mine waste and mine adit discharges
will do little to restore Tenmile Creek to a healthy stream condition if
there is no flow. Accordingly, I believe that the proposed Travis Creek
reservoir is the key element for any significant long-term improvement
in Tenmile Creek water quality and that the reservoir should be the
cornerstone of any preferred alternative.
My idea of a preferred alternative, which would cost substantially less
than alternative 4 and offer more improvement to the overall quality
and health of the Tenmile Creek watershed, includes the following
elements:
that addresses all aspects of contaminant source loading; the solid
media removal effort is but one aspect of the entire remedy.
EPA agrees that three adit discharges in the immediate Rimini area are
the primary contaminant loaders to Tenmile Creek. EPA has proposed a
phased approach to dealing with those adit discharges. The phased
approach will attempt first to control contaminant sources and reduce
discharge flow rates, so that the need for and cost of long-term O&M
for treatment facilities can be minimized. This approach has been
developed in cooperation with the State of Montana, which will be
responsible for operating the adit discharge treatment facilities in
perpetuity, after an initial 10 years of EPA-funded operation.
EPA agrees that augmentation of flows in Tenmile Creek during
low-flow periods is critical to success of the remedy. The selected
remedy provides for flow augmentation through construction of
additional storage capacity in Chessman Reservoir rather than through
construction of a new reservoir at the Travis location.
These comments, which summarized and repeat the previous
comments, are noted.
Upper Tenmile Creek ROD
C-77
-------
Comment Letter from Chuck Parrett on Draft Proposed Plan - July 9, Response
2001
(1) Removal of mine waste at only the sites currently being
worked on,
(2) Treatment of all mine adit discharge water, and
(3) Construction of Travis Reservoir.
In conclusion, I thank you and EPA for your efforts to include everyone
in the decision-making process. I also commend EPA for being so
considerate of landowners during the current cleanup activities, and I
thank you for the opportunity to respond to the proposed clean-up plan.
Sincerely,
Chuck Parrett
Upper Tenmile Creek ROD C-78
-------
Comment Email from Mark Poors on Draft Proposed Plan - July 17, Response
2001
To: Mike Bishop/ MO/ R8/ USEPA/ US@EPA
Subject: Alternatives for Rimini Cleanup
07/17/01 04:49 AM
Dear Mike.
I have looked at all the alternatives for the for the Rimini cleanup and I The comment is noted. Alternative 5, with minor modifications made in
feel that the alternative that may suit the community the most would be both the final proposed plan and the ROD, is the remedy selected by
alterative 5. The information was forwarded to me by friends who EPA.
attended the meeting. The cleaning up the adits and making good use of
the water is important! I feel a delivery system should also be
developed for the residents of Rimini even though some may not
connect to it in the near future. Cost to the residents is also an important
consideration.
Thank you for your time!
Kind Regards,
Mark A. Poore
Upper Tenmile Creek ROD C-79
-------
Comment Letter from Jim Posewitz on Draft Proposed Plan - August Response
30, 2001
August 30, 2001
Mike Bishop, EPA Project Manager
U.S. Environmental Protection Agency
301 South Park Avenue, Drawer 10096
Helena, MT 59626
Duane Harp, District Ranger
Helena Ranger District
2001 Poplar
Helena, MT 59601
Dear Mike and Duane,
Following the field tour of the Upper Tenmile Creek Mining Area Site
(the 'site' ) on August 29, 2001: and a review of the "DRAFTProposed
Plan, Upper Tenmile Creek Mining Area Site, Lewis and Clark County,
Montana, my concern for protection of existing wildlife values has
grown considerably. The concern includes the following items: (1) the
assessment process, (2) habitat security for resident elk and other
wildlife, (3) the Tenmile watershed's value as a wildlife corridor, and
(4) the long term cumulative impacts of federally sponsored,
authorized, or accommodated activities. This commentary is provided
as part of the public participation response required under Section
117(a) of the Comprehensive Environmental Response, Compensation
and Liability Act of 1980, 42 USC Section 9601 et se^. (CERCLA or
Superfund).
(1) THE ASSESSMENT PROCESS
Upper Tenmile Creek ROD C-80
-------
Comment Letter from Jim Posewitz on Draft Proposed Plan - August
30, 2001
Response
While I am totally in favor of cleaning up abandoned mines I was
surprised to see the amount of activity and disturbance already underway
in this project. This activity seems to be occurring while questions
relative to what it is impacting, what the final disposition of its roads and
other features will be, and what the requirements of potentially
responsible partners will be. Likewise, in the draft proposed plan there is
not a single word or acknowledgement of the existence of terrestrial
wildlife resources dependent on affected public lands. Those of us
accustomed to addressing public resource values have an expectation that
those resources will be inventoried, documented and addressed in a
written planning process that we can respond to. Having now been
introduced into the watershed community meeting approach we will
participate when possible, however, we must begin with a written
understanding of how the features of this project will address our specific
concerns. In addition, we feel it the responsibility of the project to
provide us a valid inventory and description (written) of the affected
environment, including terrestrial wildlife.
(2) HABITAT SECURITY FOR RESIDENT ELK AND OTHER
WILDLIFE
As mentioned on the field tour of August 29th area sportsmen and
women have a major concern for the habitat security of the elk herd in
this watershed. For at least half a century these public lands have had
sufficient habitat security to allow the herd to prosper and for hunted
animals to reach a mature condition that provided older aged bulls for
hunters to pursue. Your expanding network of upgraded roads is a clear
and direct
The proposed plan is a brief summary of key elements of the RI/FS, risk
assessments, and other key project studies and an identification and
explanation of EPA's preferred alternative for remedial action at the site.
As a brief summary or general public review, it cannot include a full
inventory of environmental conditions at the site. More detailed
information about environmental resources is included in the ecological
risk assessment. However, it is important to recognize that the intent of
Superfund is to remediate releases of hazardous substances, so the focus
of the ecological risk assessment and other RI/FS documents is on
identifying the nature and extent of contamination and the impact of that
contamination on human and ecological receptors. Under Superfund,
cleanup action is warranted if an imminent and substantial risk to humans
or the environment is documented. A full inventory of potentially
affected species is not necessary. However, EPA will work to reduce the
impacts of cleanup activities in relation to the wildlife resource.
EPA's intent is to not increase the amount of access in the watershed as a
result of its cleanup actions. EPA will make improvements to current
roads or build new roads, as necessary, to gain access to waste sites for
cleanup. Unless there are compelling reasons to do otherwise, EPA will
return or remove new roads to approximate pre-cleanup conditions.
During remedial design, EPA will work closely with federal and state
Upper Tenmile Creek ROD
C-81
-------
Comment Letter from Jim Posewitz on Draft Proposed Plan - August
30, 2001
Response
threat to that habitat security. In addition, parts of the program under
consideration pose a severe threat to habitat features conducive to elk
well being. Likewise, other activities being conducted or allowed by
other federal land managers have the potential to degrade elk habitat
quality. All of these direct threats to elk and other wildlife must be
addressed as part of the federal action that is creating the impact and not
deferred to some future analysis. Many of the features now being
federally imposed on habitats may not be reversible and must be
addressed. For example: the status and future of the expansive network of
roads to private holdings being constructed by the federal government
across the national forest lands must be clearly described and their future
public use addressed.
(3) TENMILE WATERSHED'S VALUE AS A WILDLIFE
CORRIDOR
land and wildlife resource managers and private property owners to
define road construction and reclamation/ removal specifications. EPA
does not believe it will be necessary to construct new permanent roads or
expand significantly the current network of roads to private holdings
within the national forest; most mine sites targeted for cleanup currently
are accessible by unimproved roads.
There has been considerable effort invested in the concept of wildlife
habitat corridors that connect fragmented populations of important
wildlife species. These concepts have considerable support within the
scientific community and among some federal wildlife agencies. The
Tenmile watershed is a part of the corridor identified as essential to
connect important North American wildlife species. One example would
be the grizzly bear and maintaining a viable habitat connection with bear
populations of Yellowstone National Park to those of the Bob Marshall
Wilderness Complex and other bear populations further north. This
project and other federal land management decisions in this watershed
are crucial to maintaining a suitable corridor environment. A review of
corridor identifications that
The comment is noted. EPA believes that its cleanup actions can be
conducted with minimal impact on wildlife populations in the Tenmile
Creek watershed.
Upper Tenmile Creek ROD
C-82
-------
Comment Letter from Jim Posewitz on Draft Proposed Plan - August
30, 2001
Response
have been described indicates this general area to be extremely narrow
and thus vulnerable. There is a responsibility to address this issue and
plan the final outcome of this reclamation effort to be compatible with
corridor conservation and integrity.
(4) LONG TERM CUMULATIVE IMPACTS
The impact of this reclamation seems to include permanent intrusions
into the wild character of this watershed. While maintaining and restoring
a wild nature to the watershed would be conducive to long term water
quality maintenance, it is not addressed. Rather, it is compromised with
the extensive material hauling network and no clear plan to eliminate all
the haul roads being upgraded or constructed across the federally
administered public lands. Here again, these are items that should have
been addressed before the work began and now, at best, must be
addressed while this project is underway, not deferred to some future date
when project funding and interest are gone.
Concluding Comments
It must be reiterated that the clean up effort is needed and supported.
However, the ancillary impacts must not be allowed to create an entire
new set of environmental problems to contaminate the watershed in a
variety of other ways. That contamination might well include: an
excessive and unmanageable road and off highway vehicle (OHV)
network; sustainable and effective elk habitat compromised or destroyed;
elk security habitat diminished, and critical wildlife corridors ruptured
and fragmented. This project literally screams for a
Water quality within Tenmile Creek and some tributaries is severely
degraded by contamination from historic abandoned and inactive mine
sites. Without substantial cleanup of mine wastes and acid mine drainage,
restoring the "wild nature to the watershed" would do nothing to improve
long-term water quality. EPA will work closely with land and wildlife
resource managers and private property owners in designing,
construction, and reclaiming appropriate access roads over which to
conduct the necessary cleanup actions. EPA believes that mine site
cleanup can occur without significantly impacting the ""wild character"
of the watershed.
The comment is noted. EPA has already begun the process of addressing
wildlife issues associated with this project by facilitating an initial set of
meetings with affected parties to develop appropriate strategies for access
road implementation and reclamation/removal and land management and
development constraints. The coordination process on this issue will
continue through remedial design and remedial action.
Upper Tenmile Creek ROD
C-83
-------
Comment Letter from Jim Posewitz on Draft Proposed Plan - August Response
30, 2001
cumulative effects analysis and to date we have a federal project building
roads and hauling dirt with no written analysis that addresses the
concerns of terrestrial wildlife.
In summary, this is not a request or suggestion to stop cleaning up the
physical damage done by mining in this watershed. It is an urgent plea to
immediately begin an effort to address the present and future needs of
wildlife on these public lands. We believe in the final analysis the
protection of wildlife and wild land values will contribute to the
long-term quality of the Tenmile watershed and water supply.
Sincerely,
Jim Posewitz
CC
Torn Clifford, USFS
Mike Korn, MTFW&P
Upper Tenmile Creek ROD C-84
-------
Comment Letter from John Rundquist on Draft Proposed Plan - July
19, 2001
Response
July 19, 2001
United States Environmental Protection Agency
Robert L. Fox
Superfund Program Manager
Region 8, Montana Office
Federal Building, 301 South Park, Drawer 10096
Helena, Montana 59626-0096
Subject: Draft Proposed Plan for the Upper Ten Mile Creek
Mining Area Superfund Site
Dear Robert;
In behalf of the City of Helena thank you for the opportunity to comment
on the Draft Proposed Plan date July 2, 2001. As you know, Helena is
very interested in the solutions for the mine waste cleanup because of the
watershed's importance to the City of Helena's municipal water supply.
The Ten Mile drainage is Helena's original water supply and has been
used for this purpose for more than a century. The city has much invested
in the continued reliability of this source. In addition to a safe and cost
effective water supply, Helena is very interested in sharing the watershed
in partnership with all the affected interests including recreation, fish,
wildlife, residents, and landowners. We are very appreciative of the
efforts to date to contain and treat the hazardous waste generated by past
mining activity.
Of the alternatives presented in the draft, we strongly support alternatives
5, 6 and 7 because they all include the Travis
The city's support for an additional water storage reservoir at the Travis
location is noted. The preferred alternative in the final
Upper Tenmile Creek ROD
C-85
-------
Comment Letter from John Rundquist on Draft Proposed Plan - July
19, 2001
Response
Reservoir option. The reservoir option can allow a base maintenance flow
to be managed in the stream without impacting Helena's water supply in
any major way. This is important for the reasons that follow.
Water for city use is presently diverted above the town of Rimini and
above most of the mine adits of concern to stream water quality. The
City's use of the water means higher concentrations of mine waste in the
streamflow below the diversion. Treating new adit waste and removal of
tailings will help to relieve this problem, but water quality in the stream
may continue to have high concentrations of undesirable contaminants
during low flows below the diversion due to mine wastes already released
from more than a century of mining activity. A managed maintenance
flow can help maintain water quality in Ten Mile Creek during periods of
low flow. We understand that this has a great potential to restore, protect
and enhance aquatic habitat within that reach of Ten Mile Creek
downstream of the City's diversion. From the City's perspective this adds
water to the stream during low flow that would not impact City water
rights.
The City may be able to assist with the success of alternatives 5, 6 or 7
and Rimini Water Supply Alternatives C, D or E by operation of the new
reservoir and Rimini's water treatment. This seems prudent and feasible
as the City already has certified water treatment operators and operates
two other reservoirs in the watershed. Of course, this would require
approval of the Helena City Commission but could be supported by staff
providing that O&M expenses would be fully recovered.
proposed plan and the selected remedy provide for additional water
storage by upgrading Chessman Reservoir and the Red Mountain flume.
EPA chose the Chessman upgrade option to reduce the project's potential
adverse impacts on wetlands and wildlife security, in response to other
comments. EPA understands that the City of Helena considers the
Chessman upgrade option acceptable, but less preferable than a new
reservoir at Travis.
The comment is noted and the city's willingness to consider operation of
the water storage reservoir and Rimini community water system,
provided that city O&M expenses are recovered, is appreciated by EPA.
Upper Tenmile Creek ROD
C-86
-------
Comment Letter from John Rundquist on Draft Proposed Plan - July Response
19, 2001
Thank you again for the opportunity to comment. We look forward to
continuing partnership with the Ten Mile Watershed Committee and a
successful solution to Ten Mile mine waste cleanup efforts.
Sincerely,
John Rundquist, P.E.
Public Works Director
c. Tim Burton, City Manager
Ten Mile Watershed Steering Committee, c/o Jess Aber,
DNRC
Upper Tenmile Creek ROD C-87
-------
Comment E-mail from Don Skaar to Mike Bishop - July 12, 2001
Response
To: Mike Bishop/ MO/ R8/ USEPA/ US@EPA
Subject: Tenmileplan
07/12/01 01:41PM
Mike: Just a few comments on this morning's meeting. Two issues that I
believe you need to take into account when doing your ranking for the
nine criteria for each alternative. First, keep in mind the point I made that
alternative 4 does not appear to totally eliminate acute toxicity to fish.
This should reduce it's score under Overall Protection of Human Health
and the Environment, at least relative to the reservoir alternatives.
Secondly, without flow augmentation, the high water temperatures and
low dissolved oxygen that occur in late summer will exacerbate or
compound the detrimental effects resulting from metals. This should also
serve to reduce the Overall Protection score. If you need citations for
these effects, let me know.
Lastly, given the obvious benefits of flow augmentation to water quality,
I would hate to see this approach not explored to its fullest. We all know
that changing the point of diversion for the city down to the Treatment
Plant would improve water quality as well, and would cost much less
than building a reservoir. Therefore, I believe the analysis of alternatives
should include one for changing the point of diversion. The only
justification for not doing so is if you think that we really are going to
build the reservoir. I also don't ever remember John Rundquist saying
The comment is noted. EPA agrees that Alternative 5 is preferable in
terms of flow augmentation, water quality improvement, and protection
of the fishery and aquatic environment. EPA's selected remedy,
Alternative 5, contains components for additional water storage and
Tenmile Creek flow augmentation.
EPA agrees that flow augmentation is critical to the successful cleanup of
Tenmile Creek. Additional storage will allow EPA to achieve flow
augmentation with little effect on the manner in which the City of Helena
operates its water supply system. Relying on a lower diversion structure
on Tenmile Creek (presumably near Walker Creek or the Tenmile Water
Treatment Plant), without additional flow augmentation, would cause the
city to receive water with poorer quality than present, as a result of
unavoidable degradation of water quality in the Rimini vicinity. The
additional storage/flow augmentation alternative
Upper Tenmile Creek ROD
C-8
-------
Comment E-mail from Don Skaar to Mike Bishop - July 12, 2001
Response
"no" to the change in diversion idea, just that there were issues to work
through.
Let me phrase this argument a little differently. I know you are including
the reservoir alternative rather than the change in point of diversion
alternative because it is the preferred alternative of the city. I am OK with
that approach as long as we actually choose it! Otherwise, you are
shortchanging the flow augmentation idea by not considering all
possibilities. Are we really sure the city wont consider the diversion
change—even as a paper exercise?
Don Skaar
Water Pollution Biologist
Montana Fish, Wildlife and Parks
1420 East 6th Ave.
Helena, MT 59620
406-444-5686 (voice)
406-444-4952 (fax)
dskaar@state.mt.us
would allow the city to generally intercept tributary water prior to its
exposure to the main degradation sources in Rimini, maintaining similar
input water quality to what it has currently. Although it is not an aspect of
EPA's selected remedy, the city is evaluating a possible lower diversion
structure on Tenmile Creek. The loading model developed by EPA can
be used by the city and the upper Tenmile Watershed group to work out
refinements in the management of Tenmile Creek diversions that would
complement EPA's cleanup actions and provide additional benefit to the
fishery.
Q:\Tenmile\Record of DecisiorAFinalROD (for real) June 2002\Append C - Respons Summ\C-11\DonSkaar Columns.wpd
C-89
-------
Comment E-mail from Sam Stewart on Draft Proposed Plan - July 24,
2001
To: Mike Bishop/ MO/ R8/ U SEP A/ US@EPA
Subject: Upper Ten Mile Creek Mining Area Superfund Site
07/24/01 12:24 PM
Response
July 24, 2001
RE: Draft Proposed Plan for the Upper Ten Mile Creek Mining Area
Superfund Site dated July 2001 (US EPA)
Upper Tenmile Creek Mining Area Rimini, Lewis and Clark
County, Montana EPA Facility ID: MTSFN 0801699 dated April
24, 2001 (U.S. Department of Health and Human Services, Agency
for Toxic Substances and Disease Registry)
Rimini Community Meeting with other Agencies 11 July 2001
Helena Independent Record article "Rimini, Tenmile Creek area
considered "public health hazard""
Dear Mike,
As per 1st reference I would like to provide comments.
At the referenced Rimini Community Meeting a potable water source
was discussed and I believe it was generally agreed upon that the
community supported a water source if it could be economically
managed by the City of Helena or some other
The comment is noted. EPA estimates that costs to users of a community
water system can be kept in line with Helena water costs if a suitable
groundwater source relatively close to Rimini can be located and if
approximately 35 connections can be made
Upper Tenmile Creek ROD
C-90
-------
Comment E-mail from Sam Stewart on Draft Proposed Plan - July 24,
2001
Response
qualified entity. Also, the cost of the water to individuals needed to be in
line with the Helena water costs. Obviously, the final determination will
be dependent on currently unanswered questions.
I support the principal of a central water system dependent on these
unanswered questions. Building a reservoir to augment stream flow in
Ten Mile Creek was also discussed. I support this concept to improve the
watershed and fishery in Ten Mile Creek but it became apparent to me
that this reservoir was not necessary for a water supply to Rimini
residents. I believe the money used to build a reservoir could be better
utilized to eliminate other health hazards.
to the system. The City of Helena has expressed interest in operating the
system for the community of Rimini if its costs for operating the system
can be recovered.
The comment is noted.
The EPA and Dept of Health and Human Services currently agree that the
Ten Mile Creek road to Rimini has hazardous waste which is toxic and
poses an immediate threat to exposed people. The Agency for Toxic
Substances and and Disease Registry are quoted in part to say that
"Rimini and the surrounding Tenmile Creek area is designated a public
health hazard because of the arsenic or cadmium in road dust."
The comment is noted.
Currently, Magnesium Chloride is being used to abate the dust on the
road to Rimini. I propose that this is not a satisfactory dust control
method. Magnesium Chloride has been documented to be extremely
corrosive in nature and it kills plant life. If it kills plant life, how toxic is
it to humans? Some of the Magnesium Chloride has to be leaching into
Ten Mile Creek. How does this effect the fishery? Continuous treatment
of Magnesium Chloride is needed to keep dust down. This is not
EPA has reviewed potential human health and ecological risks associated
with magnesium chloride and concluded that its use does not present
significant risk. Magnesium is an essential and plentiful element in the
human diet and the body is equipped to absorb and use it efficiently.
Intake of extremely high concentrations over long periods, such as
overuse of antacids containing magnesium, can have toxic effects.
However, those concentrations would not be reached by incidental
contact with
Upper Tenmile Creek ROD
C-91
-------
Comment E-mail from Sam Stewart on Draft Proposed Plan - July 24,
2001
being done and dust is still a problem to Rimini residents and those
residents who live near the road. It is a double edged sword because if
you put more Magnesium Chloride on the road you are just aggravating
the toxic characteristics. It appears to me the most satisfactory method of
dust control would be to pave those areas which have had mine tailings
used to build the road. I would rather see money put into paving the road
than building a reservoir.
These are the comments that immediately come to my mind. Sorry that I
missed the deadline date but hope my comments are taken into your
consideration.
Response
road or dust particles. Acute toxicity from magnesium chloride in aquatic
species occurs at concentrations greater than 1,000 mg/L. Instream
concentrations are very unlikely to approach anything near those levels,
so potential impact on the fishery is considered insignificant. EPA has
selected a remedy for roadways that requires excavation of all accessible
contaminated materials. After the removal of contaminated materials is
complete, the potential for road dust to contain mining-related
contaminants is eliminated and dust control related to the Superfund
action will not be necessary.
Sam Stewart
3474 Rimini RD
Helena, MT 59601
Upper Tenmile Creek ROD
C-92
-------
E-Mail from Diane Tipton to Mike Bishop - August 6, 2001
August 6, 2001
Mike Bishop
EPA
Mike -
I have some questions and comments that I've decided are best shared
with you by email. The informal discussions in meetings and by phone
are not being productive. In cases where you think I should read
particular documents, you may indicate which documents you'd
recommend. However, my questions are simple and I, and most private
citizens, appreciate your time in providing simple, direct answers rather
than being referred to documents that we then need to track down.
1.1 want to know when the draft Upper Tenmile Project Plan is expected
to be final, what the expected timeframe and dates are for public
comment and what "publics" will have the opportunity to comment. Will
the EPA ask for comment from people in the City of Helena, just in
Rimini, in Helena and the surrounding area?
Response
1. The draft proposed plan was provided to agencies and
Rimini-area individuals to obtain informal public input on the
remedial options being considered by EPA. The formal proposed plan
was issued on October 22, 2001. The general public, including Helena
and the surrounding area, was invited to comment. Public hearings on the
proposed plan were held in Rimini and Helena.
2.1 want to know what the City of Helena's relationship to the Travis
Reservoir will be, if any. Would water stored in the proposed reservoir be
part of, or separate from, the City's existing water right on Tenmile
Creek? What agency would manage the proposed reservoir?
2. The Travis location is not part of EPA's current plan. Additional
storage is now planned for Chessman Reservoir, which is managed by the
City of Helena. The City of Helena would continue to manage Chessman
for its water supply. The city has agreed in principle to release additional
water from Scott Reservoir during low flow periods and to allow that
water to bypass its diversion structure on Tenmile Creek above Rimini.
Upper Tenmile Creek ROD
C-93
-------
E-Mail from Diane Tipton to Mike Bishop - August 6, 2001
Response
3. I'd recommend that there be a physical description of the estimated
size and scope of the proposed reservoir included in the copy of the plan
that the public reviews. It is difficult to comment on a proposed reservoir
when there is no quantitative information to help us evaluate the size,
scope, environmental impact etc. of such a reservoir.
4. How will the document be presented? Will there be a meeting
explaining the various alternatives and their relative merits? A public
presentation on the comparative merits of the different water quantity
solutions would be valuable when your full plan is presented to the public
for comment.
5. When will the environmental impact study EPA is required to prepare
under the NEPA process going to be completed and available for public
review?
My comments are as follows. My interest is in doing what I can to keep
the public discussion and work undertaken in the Upper Tenmile focused
on what is necessary to do the clean up job. I want to minimize as much
as possible impacts on the forest and on wildlife, to minimize the amount
of land involved in the clean up to the degree possible, and to avoid
significant changes in land use or in the nature of this area. I strongly
oppose any move that will increase recreation into the Upper Tenmile
Watershed, widen roads and further open up the wildlife habitat here. I
also oppose moves that will change the character of the gulch or the life
style of those who live here.
3. Additional details about the Chessman Reservoir upgrade and other
reservoir options are included in the RI/FS addenda report. The Travis
reservoir location is not part of EPA's selected remedy.
4. The alternatives were discussed and presented at a number of monthly
public meetings of the Upper Tenmile Watershed Steering Committee
and at the two public hearings on the proposed plan.
5. EPA's Superfund RI/FS process, which includes scoping meetings,
evaluation of alternatives relative to specified protectiveness and
effectiveness criteria, and full public comment, has been determined to be
the functional equivalent of the NEPA process. No separate NEPA
analysis is required.
These comments are noted. EPA has attempted to prioritize proposed
cleanup actions to address only those sites that are considered significant
contaminant sources and has committed to conducting its cleanup in a
manner that minimizes access road improvement and impacts on the
forest and wildlife.
Upper Tenmile Creek ROD
C-94
-------
E-Mail from Diane Tipton to Mike Bishop - August 6, 2001
Response
The EPA's work is to clean up the environment and it should be
restricted to that goal, in my personal opinion. The residents of this area
should not have to deal with a whole host of outside agencies in making
decisions that affect our homes, the level of recreation around us, the
quality of the wildlife habitat here etc. Those issues were never on the
table and have no place in a discussion about a clean up effort.
The City and the EPA signed on as cooperators for the Upper Tenmile
Watershed Noxious Weed Grant when I took on the job of being the
resident coordinator. As the coordinator I expect both the City and the
EPA to spray for noxious weeds in 2001 everywhere weeds occur on
lands owned by the City or disturbed by the EPA. Our verbal agreement
was that the EPA would also spray where needed last fall. The City has
sprayed some of their lands but has not sprayed the leased pasture or the
hillsides that are the worst offenders.
For the EPA, I don't think I should have to call someone in Denver to
find out if your group sprayed here in Montana last fall or will again this
year. I expect you as project manager and spokesperson to provide that
information to me and to Jesse Aber. My offer to help you or your people
identify weeds in the work areas was genuine, even though it will require
my personal time, which is extremely valuable to me. I also wrote the
state noxious weed grant for the Upper Tenmile in my personal time and
I take my personal time to attend the watershed group meetings. The cat
and mouse game you put me through at the last watershed group meeting
wastes my time and the groups and is not acceptable to me.
Under this project, EPA and the State of Montana are assuming
responsibility for cleaning up contaminant releases from abandoned or
inactive historic mining operations. EPA will work with the land and
wildlife management agencies and the city and county planning
departments regarding land use, recreation, and wildlife habitat issues.
EPA will continue to require that weed-free borrow soils and vegetative
matter be used at its Superfund cleanup sites and will implement a weed
control program, as needed, at EPA's reclaimed sites. Following cleanup
and reclamation activities, the state will assume responsibility for
ongoing maintenance. EPA cannot require that the City of Helena spray
for weeds on city property.
EPA appreciates all of the time that you devote to the control of noxious
weeds in the upper Tenmile Creek watershed and to the assistance you've
provided throughout the Superfund project.
Upper Tenmile Creek ROD
C-95
-------
E-Mail from Diane Tipton to Mike Bishop - August 6, 2001
My concern about the proposed Travis Reservoir is that I want to see the
EPA do what it can to ensure the public discussion of this proposal stays
on track. It is a "water quantity" solution and, I think, should be presented
as such. It will color the public's input to suggest that the proposed
reservoir will increase recreational opportunities down the road. In fact,
I'd like to see the EPA state that recreation is not the purpose or intention
of the reservoir. I'd also like it stated for the public whether or not the
proposed reservoir will also be available to the City of Helena as a water
supply at some future date.
Response
EPA is proposing the creation of additional water storage in the upper
Tenmile Creek watershed to allow for improved water quality and stream
habitat in Tenmile Creek during the annual periods of low flow. EPA is
not proposing additional recreational opportunities, although increased
fishing opportunities will be a benefit of improved water quality and flow
conditions. Chessman Reservoir currently is not used for recreational
purposes. EPA assumes that it would continue to be closed to recreation
after the upgrade.
Mike, I want you to know that I appreciate and respect your work on the
draft plan and that of your agency. I also am aware that this is a very
complex project with many aspects I don't understand and that are
beyond my time and in some cases my ability to understand. As a private
citizen I can not attend all of the meetings. I appreciate these facts every
time I ask questions. Brief, bulleted responses will be sufficient. Please
enter my comments as appropriate. I assume there will be an additional
public comment period when I can send in any additional comments. If
some things are unknown at this time, you could just indicate that and tell
me when you think you might know.
Thanks very much for your time.
Diane Tipton
Upper Tenmile Creek ROD
C-96
-------
Comment Letter from Diane Tipton on Draft Proposed Plan - July 23,
2001
July 23, 2001
United States Environmental Protection Agency
Attn: Mike Bishop
Federal Building
301 S. Park
Drawer 10096
Helena, Montana 59626-0096
Dear Mr. Bishop:
I have reviewed the Draft Proposed Plan for the Upper Tenmile Creek
Mining Area Site in Lewis and Clark County. The proposed alternatives
address adit discharges in a variety of ways including physical/ chemical
treatment of three adits in the Rimini area, water inflow reduction and/or
biological treatment of all adit discharges. It appears that in all cases all
adits would be treated in some way.
I would like to see greater flexibility in the plan to characterize or
categorize the adits. Some adits are in remote areas surrounded by fragile
habitat where there would be no other reason to disturb the environment
and they are having very little if any measurable impact on the
environment. The plan takes the time to assess the mine waste dumps
based on how much of a contributor they are to the problem. I think there
should be similar approach to rating the adits.
The treatment plan for certain adits that do not significantly contribute to
the pollution problem in and around the town of
Response
EPA has added provisions to the final proposed plan and ROD whereby
EPA will evaluate and weigh further during remedial design the water
quality improvements achievable at specific adits vs. the potential
adverse impacts of constructing and operating treatment facilities at those
adits. The primary reason EPA expects that some treatment would be
required at all adits is that the adit discharge waters typically exceed state
ambient water quality standards for some parameters. In order for the
remedy to comply with state water quality standards, which it must under
the Superfund law, unless the standard is waived, EPA anticipated that
treatment would be required. During
Upper Tenmile Creek ROD
C-97
-------
Comment Letter from Diane Tipton on Draft Proposed Plan - July 23,
2001
Rimini should also be flexible. If there is little appreciable impact on
surface or ground water quality in the area, minimal or no treatment
should be an option. Also, in cases where the local community requests it
for specific environmental, wildlife habitat or other concerns, the plan
should allow for a assessment of the environmental damage incurred by
treating the area as compared to performing minimal or no treatment.
As we've discussed before, the planned clean up of the Upper Tenmile
area is extensive and very pricey for taxpayers. It is only reasonable that
the plan be as flexible as possible so that in cases where a site has little or
no overall impact we aren't bound to "over" treat it.
I also believe that the local community should be allowed to have input
and influence on whether "noncontributing" sites are treated and how.
Response
remedial design, EPA will, in consultation with DEQ, consider both
relative overall contaminant loading and compliance with state water
quality standards for individual adit discharges.
The comment is noted.
The public is offered the opportunity to comment and have input on all
components of the site remedial plan. However, under Superfund, public
comment is a '"modifying criteria." Remedies are required to meet the
two threshold criteria of "protectiveness of human health and the
environment" and "compliance with ARARs."
Thank you for the opportunity to have input. If you have any questions,
don't hesitate to call me on 444-3079.
Sincerely,
Diane M. Tipton
Upper Tenmile Creek ROD
C-98
-------
Comment Letter from R. Mark Wilson on Draft Proposed Plan - August
2, 2001
August 2, 2001
Mike Bishop
Remedial Project Manager
U.S. Environmental Protection Agency
301 South Park, Drawer 10096
Helena, MT 59626
Dear Mr. Bishop:
The U.S. Fish and Wildlife Service (Service) has reviewed the document
entitled, "Draft Proposed Plan, Upper Tenmile Creek Mining Area Site,
Lewis and Clark County, Montana" under a technical assistance
Interagency Agreement with EPA. The Service has several comments on
the draft document.
Travis Reservoir Site
The proposed site for Travis Reservoir is located on an 84 acre wetland
(see enclosure). During a site visit to this wetland the Service noted its
high functional value, and its apparent pristine condition. Inundation of
this area and construction of the dam would result in a loss of nearly all
of the present wetland. Further, wetland areas not directly impacted from
construction or inundation could be impacted from hydrologic changes
associated with fluctuating water levels. Compliance with wetland
Applicable or Relevant and Appropriate Requirements (ARARs) would
require mitigation of this wetland.
Mitigation of a wetland this large within the Tenmile site will be
difficult. The Service is not aware of a mitigation site (i.e., an
Response
EPA concurs with the U.S. Fish and Wildlife Service opinion that
mitigation of the lost wetlands at the potential Travis Reservoir location
would be difficult. Largely for that reason, EPA has selected a remedy
that includes the upgrade of existing Chessman Reservoir to provide
additional water storage for flow augmentation. The loss of wetlands will
be substantially reduced at the Chessman location.
Upper Tenmile Creek ROD
C-99
-------
Comment Letter from R. Mark Wilson on Draft Proposed Plan - August
2, 2001
area with suitable topography) that does not currently contain a wetland.
For example, if Banner Creek wetland was chosen as a mitigation site, it
would most likely not satisfy all the mitigation requirements. Although
similar in size, the Banner Creek site is currently a wetland, and although
impaired, still has some function. Compliance with ARARs would result
in improvement of all the Banner Creek wetland, as well as wetland
creation, restoration and enhancement at another site(s).
The Service estimated the number of mitigation acres needed for the loss
of Travis Reservoir wetland using the Habitat Equivalency Analysis
(HEA) model. This model estimates the acres needed for mitigation, and
results ranged from 111 acres (if the mitigated wetland has the same
productivity as a natural wetland) to 183 acres (if the mitigated wetland
has only half the productivity as a natural wetland). The Service has
concerns about mitigating a high altitude wetland because of the time
required for the wetland to become fully functional under short growing
seasons. In the HEA, increases in time for a wetland to become fully
functional result in increased mitigation acres required. In order to
minimize that recovery periods and thus reduce the loss of wetland
services, and the required mitigation acreage, the Service recommends
that mitigation be completed prior to the loss of the Travis Reservoir
wetland, to reduce the amount of lost wetland services, and thus the
mitigation acreage required.
Biological Treatment Wetlands
Currently the preferred alternative includes the use of constructed
wetlands for treatment of adit discharges. These
Response
EPA concurs that the constructed wetlands envisioned for treatment of
acid mine drainage would not constitute wetlands
Upper Tenmile Creek ROD
C-100
-------
Comment Letter from R. Mark Wilson on Draft Proposed Plan - August Response
2, 2001
wetlands would likely not meet the dual role of a treatment wetland and a for mitigation.
mitigation wetland. The treatment wetlands (as the Service understands
they would be constructed) would likely not meet the jurisdictional
wetland criteria and as such, would not be appropriate wetlands for
mitigation.
Thank you for the opportunity to review and comment on the
aforementioned document. The Service looks forward to participating in
the remediation of the Upper Tenmile Creek Mining Area Site. Should
you have any questions concerning these comments or require additional
information, please contact Ms. Karen Nelson of this office at (406)
449-5225, extension 210.
Sincerely,
R. Mark Wilson
Montana Field Supervisor
Enclosure
cc: USEPA, R-8, Denver, CO (Attn: Dr. Dan Wall)
Upper Tenmile Creek ROD C-101
-------
Public Hearing Comments and Responses
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
BEFORE THE ENVIRONMENTAL PROTECTION AGENCY
PUBLIC HEARING ON THE PROPOSED PLAN
UPPER TENMILE CREEK MINING AREA SITE
LEWIS AND CLARK COUNTY, MONTANA
TRANSCRIPT OF THE PROCEEDINGS
Heard Before Mike Bishop, EPA Project Manager
Rimini School House, Rimini, Montana
November 8, 2001
7:10 p.m.
REPORTED BY: CHERYL ROMSA
CHERYL ROMSA COURT REPORTING
P.O. BOX 1278
HELENA, MONTANA 59624
(406)449-6380
Upper Tenmile Creek ROD C-103
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
INDEX
PAGE
Discussion on the road and paving versus
removal 3
Discussion of the meeting re wildlife issues 5
Discussion about funding 9
Discussion on the Luttrell Respository 15
Discussion on the sampling of yards 21
Discussion about the road 24
COURT REPORTERS CERTIFICATE 30
Upper Tenmile Creek ROD C-104
-------
Proposed Plan Public Hearing, Rimini, MT- Novembers, 2001
Response
1 WHEREUPON, the following proceedings were had:
2 (An overview of the plan was presented by
3 Mike Bishop.)
4 MR. BISHOP: Now we would like to hear from you.
5 We have a court reporter here, and she'll record your
6 concerns.
7 Mike.
8 MR. McHUGH: Michael McHugh. The 18 inches of
9 road material you're going to take out, what segment of
10 the road are you talking about? Is it just in the town
11 site, or are you looking all the way down to —
12 MR. BISHOP: Our thought is primarily in the
13 town site, but we want to have some sensitivity to
14 locations where there could be some additional
15 development. But as you're probably aware, those areas
16 are portions of the road that were washed out during the
17 flood event of 1981, and so that's where we'll be
18 looking.
19 MR. STEWART: Has there been a cost comparative
20 study as to digging out the 18 inches versus capping,
21 let's just say an asphalt or something like that?
22 MR. BISHOP: We actually just kind of rehashed
23 that this week.
24 MR. MARSH: My recollection of that number is
25 that it was about 150,000 more dollars to do the paving
The format of this meeting was primarily open discussion and
question and answer. EPA's responses to most comments are provided
directly in the discussion and are not repeated in this column.
Clarifications are noted in this column if necessary.
The contaminated road material is believed to extend
approximately from the road adjacent to the Helena water
system intake structure north to junction with the Beaver Creek
road. EPA plans to address that portion of the road adjacent to the
residential area of Rimini. The road north of Rimini crosses
national forest service land that will not be residentially developed, so
EPA does not plan on removing that portion of the road.
EPA has reevaluated the alternative of capping the road with
asphalt. New estimates, based on conversations with county
road maintenance personnel involved in the rebuild of the road
in 1981, indicate that approximately 5,000 feet of roadway will
have to be remediated. At this length of road requiring
remediation, EPA has determined that capping/paving would be
a cost-effective alternative. However, EPA has also consulted
with the State of Montana regarding the remedy for roadways.
The state has expressed concern about the need to maintain
either a paved cap or a gravel cover over time and the potential
remobilization of contaminants left in place during major flood events,
such as the flood of 1981. EPA has therefore included the
Upper Tenmile Creek ROD
C-105
-------
Proposed Plan Public Hearing, Rimini, MT- Novembers, 2001
Response
1 than to do the removal, if I remember right.
2 MR. STEWART: And does that include the
3 follow-on maintenance of what it would cost to maintain
4 a dirt road versus a paved road, as far as the County is
5 concerned?
6 MR. MARSH: Yeah, those numbers were the — it
7 was the present worth that included the capitalization
8 of the maintenance over a 30-year period.
9 MR. STEWART: I would sure like to see that
10 study, if possible.
11 MR. MARSH: And Sam, we got the cost estimate
12 for the paving directly from the County. We basically
13 asked the County what they would require in terms of the
14 paving alternative, and that cost estimate assumed
15 paving from approximately Martins' house down to below
16 Moores' house, basically all the way through the part of
17 town where there are houses.
18 MR. BISHOP: Yeah, I've got to smile about that,
19 because I made one phone call, and the first person
20 said, "I would certainly be in favor of that, and I
21 can't imagine anybody being opposed to it." Then I
22 spoke to the next person, and they said, "Well, I'm
23 opposed to it, and I can't imagine anybody being in
24 favor of it." So you know you're in trouble.
25 MS. TIPTON: Diane Tipton. Can you tell me a
removal of all accessible contaminated roadway materials in
Rimini as part of the selected remedy for the site.
The revised cost estimates for alternatives to address
contaminated roadway materials are provided in the RI/FS
addenda report.
EPA's response was provided by Mr. Bishop at the meeting.
Refer to his response following the comment.
Upper Tenmile Creek ROD
C-106
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 little more about — You mentioned that you hired a
2 facilitator to talk about the wildlife issues, and some
3 additional mediums. Could you just elaborate on that?
4 MR. BISHOP: Sure. And, you know, initially,
5 we've invited Chuck to that meeting, but other
6 landowners, I guess, are certainly welcome. And I guess
7 I'd see this potentially being more than one meeting.
8 But the groups that we've received the strongest
9 comment from are Fish, Wildlife & Parks, there's the
10 Helena Hunters and Anglers Group, and there's a group
11 called Orion. And they basically, I think, try to
12 represent the concern of hunters and fishermen. And
13 their concern has been, which I would imagine that
14 you've heard on some of our trips and so forth, that the
15 increased capacity of our roads for these trucks
16 encourages additional people to utilize the area. It
17 encourages people that have parcels of land to develop
18 them, and possibly to increase the pressure on the
19 wildlife and decrease the security that these bands of
20 elk would otherwise have here.
21 So what we're going to try to do — and our
22 facilitator is a really interesting person that's really
23 talented at doing this sort of thing. We're going to
24 try and bring everybody together and kind of talk about
25 what the issues are and different views among the
Upper Tenmile Creek ROD C-107
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 different parties, recognizing that many of these things
2 are not necessarily simply, you know, addressed under
3 the law that we deal with.
4 But as we have these folks together, I think
5 everybody has something potentially to contribute. And,
6 you know, certainly from our perspective, I wouldn't
7 have a problem diminishing the size of some of these
8 roads, if that's the way that we want to go when we' re
9 done, and commit to a minimum standard for the trucks
10 that we would utilize and so forth. We could line out
11 those sort of obj ectives and that sort of a path for the
12 work that we do.
13 But conversely, the groups that we're dealing with
14 also have some resources available to them. And I don't
15 know if you're familiar with conservation easements, but
16 some of these parcels of land up here are absentee
17 landowners, some of them haven't seen the parcels that
18 they own. They were doctors or attorneys or whatever
19 that were paid. And I really don't think they have an
20 interest necessarily in developing them, and we might be
21 able to bring some of these other groups to the table to
22 acquire some easements to close up some of those areas
23 as well.
24 You know, frankly, another area that has some
25 promise, you're aware that the City owns the
Upper Tenmile Creek ROD C-108
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 Travis Reservoir location and there was serious concern
2 about wildlife values there. And I don't know if you
3 know it, but the Forest Service actually owns the
4 Chessman Reservoir site. And there's been a land
5 exchange that's been discussed for a decade, I bet, and
6 I would be delighted if this process could help
7 facilitate that land exchange. The City also owns the
8 impaired Banner Creek wetlands at the head of the road
9 where it splits and goes to Scott Reservoir, and that
10 could also be involved in that exchange. And those are
11 some of the sort of things that we want to talk about.
12 But under our development of Chessman Reservoir, we
13 do impair about 14 acres of wetlands that are there
14 right now, and we have a responsibility to mitigate
15 that. Our thought is that we might be able to improve
16 some of the wetland conditions up in the Banner Creek
17 wetlands, if you're familiar with those. They were
18 inundated by overburden from the placer mining. It's
19 not really a contaminated material, but it's affected
20 the stream in such a way that it's not really a healthy
21 wetland at this point in time.
22 So those are the sort of things that we're talking
23 about.
24 MS. CANNON: Helenann Cannon. This is kind of
25 related, and you may just want to address it at the
Upper Tenmile Creek ROD C-109
-------
Proposed Plan Public Hearing, Rimini, MT- Novembers, 2001
Response
1 wildlife meeting more. I've heard scuttlebutt about a
2 road going right through Bonner Meadows, and that would
3 be a big concern to elk habitat.
4 MR. BISHOP: Well, that's on the Prickly Pear
5 side.
6 MS. CANNON: The back side of Red Mountain.
7 MR. BISHOP: See, that would not be ours. Well,
8 yeah, it might be —
9 MS. CANNON: There's another road going up
10 through into Lutrell.
11 MR. BISHOP: You're right. There is a mine
12 that's very remote.
13 Do you want to address that, Neil? Is it
14 Valley Forge or -
15 MR. MARSH: No, it's the National Extension.
16 MR. BISHOP: National Extension, I'm sorry.
17 MR. MARSH: And the most direct route from the
18 National Extension would be on the ridge above
19 Bonner Meadows there. But I'm not quite sure what the
20 status of the Forest Service's thoughts is on the
21 National Extension.
22 MR. BISHOP: And your comment is that there
23 would be —
24 MS. CANNON: That's big elk habitat up there.
25 I've been up there.
The National Extension site is a priority site for which waste
rock/tailings would be removed and disposed of at the Luttrell
repository. The route of transporting the wastes and the access
road specifications will be determined during remedial design
through consultation with the USFS, DFWP, the property
owners, and other interested parties.
Upper Tenmile Creek ROD
C-110
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 MR. BISHOP: Okay, everybody make a note.
2 MR. MARSH: I'll check it out this weekend.
3 MR. LEWIS: Dave Lewis. I'm curious about the
4 money. Now, DEQ has to go to the Legislature for the
5 State match. DEQ does not have the State match at this
6 time; I'm fairly certain of that.
7 MR. FRENCH: We have a portion of it.
8 MR. LEWIS: You have some portion of it, okay.
9 It's already appropriated?
10 MR. FRENCH: It's not appropriated. We have
11 money through credit. It's not real money, it's credit
12 that we have to use through this for ongoing operations
13 of the Basin Creek Mine.
14 MR. LEWIS: Oh, okay.
15 MR. BISHOP: EPA has given the State credit for
16 the bond money that they're spending up there. And
17 actually, there's enough credit to cover this entire
18 action.
19 MR. LEWIS: But you're still going to need
20 appropriation.
21 MR. FRENCH: Well, we'll still need money to run
22 the operation and maintenance.
23 MR. BISHOP: That's right.
24 MR. FRENCH: There is also the town of Basin
25 site and there is the Basin watershed site that we'd
Upper Tenmile Creek ROD C-111
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 like to spread this money and make last as long as we
2 can, because we foresee eventually running out of this
3 credited money somewhere.
4 MR. LEWIS: But you're not going to be able to
5 make a commitment to match the project without an
6 appropriation or some legislative authorization to do
7 so, are you?
8 MR. FRENCH: Are you asking if we have to wait
9 for the Legislature come back in session before we can
10 agree to this?
11 MR. LEWIS: Urn-hum.
12 MR. FRENCH: We can agree to it before that.
13 MR. LEWIS: But can you pay the bills, I guess?
14 MR. FRENCH: We'll pay the bills.
15 MR. BISHOP: Something that would be good for
16 you to know is that many of the cleanup activities, and
17 I guess specifically those that deal with these mine
18 adits, the way the program is set up, EPA will operate
19 those for ten years before we turn it over to the State.
20 So there is some leeway there. Also, when the State
21 would take over the responsibility for the Lutrell
22 Repository, it would be after we close that. And we
23 recognize that there's going to be some period of
24 time — five or ten years is our best guess at this
25 point — where we will continue to bring in materials.
10
Upper Tenmile Creek ROD C-112
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 So that would not be required at that point in time.
2 And also, there's a state Superfund contract that we
3 need to enter into with the State before we actually
4 initiate the cleanups. And we have agreed to work with
5 the State on a year-by-year basis where we strive to
6 meet their concerns with respect to these mines by
7 diminishing the amount of discharge from them before we
8 go into the design and construction of these water
9 treatment plants.
10 So again, that commitment will be sought on a
11 year-by-year basis. It's not like we're asking for an
12 overwhelming —
13 MR. FRENCH: 2.4 million, like you said for O&M.
14 MR. LEWIS: But you still are going to need some
15 portion.
16 MR. FRENCH: We are going to eventually have to
17 pay it. But in the beginning, no, we won't pay it.
18 MR. LEWIS: As the representative, I'm the vice
19 chairman of the Appropriations Committee at the present
20 time, and I'm in line to move up if I get elected back
21 next time. But I think that due to my position there,
22 that this group up here has some pretty major leverage
23 on this, I guess. You know, you can let me know. And
24 I'm sure it will be just like every other project we
25 deal with in this part of the world; there isn't going
11
Upper Tenmile Creek ROD C-113
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 to be a consensus, but at least I can have, through the
2 appropriation process, quite a bit to say about what
3 happens with this. Because if nothing else, I control
4 their operational budget.
5 But, you know, don't feel like you don't have some
6 leverage through the legislative process on this as this
7 moves along. And I know these guys have done a great
8 job. It certainly seems to me that they've done a great
9 job of trying to bring everyone together and work
10 together and everything else. But, you know, there's
11 one final hurdle here: The State's share of this thing
12 has to be authorized in some substance by the
13 Legislature. And that's where you can certainly let me
14 know what you're thinking about and what you're hoping
15 to happen here. Because I know we can put some
16 conditions on appropriations and those kinds of things.
17 Now, the rest of the question was, so how about the
18 federal money? Now, you have to go to Congress to get
19 the 20 million?
20 MR. BISHOP: No, it would be through our agency,
21 and we are competing on a national basis. This is a
22 national priority site. And certainly, we're aware that
23 Libby has a high level of concern, and we don't disagree
24 that they should be in line before we are. And the way
25 our agency is working right now is, they are trying not
12
Upper Tenmile Creek ROD C-114
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 to commit to new cleanup — cleanup of new sites until
2 they have funds that are available. And right now,
3 there's more requests going in than there are funds
4 available.
5 For example, the town of Basin, the record of
6 decision was done last year. They did not receive
7 funding to initiate that cleanup this past field season.
8 But, you know, you might — my supervisor, Bob Fox, is
9 here. He probably knows more about this than I do, but
10 we just know it's going to be tight for a while. But I
11 feel that it's coming, it's just a matter of waiting for
12 our opportunity.
13 MR. FOX: There's one point, if I could make a
14 comment. You know, we are in a pretty good situation
15 here by being able to look at some credit for that State
16 match, but we have other Superfund sites that have been
17 listed that don't have responsible parties and there
18 will be more need for the State match; and, of course,
19 Libby has that issue. And I do feel that it's good to
20 begin thinking about a process to go through some,
21 probably some legislative mechanism that would have some
22 funding available for matching the federal funds. If
23 not here, other places.
24 MR. LEWIS: It's an opportunity to do that. I
25 mean, we have something called the Resource Indemnity
13
Upper Tenmile Creek ROD C-115
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 Trust in Montana, where there's a tax on various mining
2 and oil and gas production, those kind of things, that
3 goes into the trust fund. Once it hits $100 million,
4 then that money is available to be used for other
5 purposes, and it's going to hit $100 million this year.
6 So there's going to be some money on the table to use
7 for these purposes.
8 I think most legislators, certainly myself, it's
9 going to be wanting to make sure this is what the
10 community wants.
11 MR. BISHOP: Sure. The thing that would be
12 important to me, and that you can carry back, it's not a
13 bad deal in the sense that the match is 10 percent and
14 the O&M starts after 10 years of water treatment and so
15 forth.
16 So I hope the State feels like we're trying to put
17 them on a pretty good footing from the very beginning.
18 MR. LEWIS: Again, as long as that's what the
19 community —
20 MR. BISHOP: I understand.
21 MR. LEWIS: If they say, "Gee, you know, we're
22 not real sure about that," then we're going to be — I'm
23 going to be in a position to say, "Well, maybe we need
24 to go back to the drawing board," just because of the
25 unique situation.
14
Upper Tenmile Creek ROD C-116
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 MR. BISHOP: Sure.
2 Steve.
3 MR. RIETEMA: My questions and concern are about
4 the Lutrell Pit. Will you cap that after your cleanup
5 is finished?
6 MR. BISHOP: Yes.
7 MR. RIETEMA: It won't be an ongoing waste site
8 where other materials from different parts of the state
9 are hauled up there and dumped, will it?
10 MR. BISHOP: Well, when that site was initially
11 evaluated by the State, they did an economic evaluation
12 of what distance would it be economically feasible to
13 bring waste from other mine sites to that location, and
14 there's about 2 million cubic yards of capacity within
15 that pit. And I prefer to call it a repository, because
16 we have engineered a lot of improvements to it.
17 But from all over the state, no. From the
18 Little Blackfoot, Travis Creek, or some of these
19 adjoining watersheds, yes. And we're trying to
20 accommodate waste from the Forest Service, potentially
21 waste from the State, and so forth, to bring it into
22 this one secure location where the maintenance at one
23 site is easier, in our opinion, than it would be to have
24 these located throughout. And I think the risk would go
25 up if we had them located at a variety of sites as well.
15
Upper Tenmile Creek ROD C-117
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 So this has been our choice, and it was a difficult
2 one, to put it in one place.
3 MR. RIETEMA: But is there a time frame attached
4 to that, then, so that at some point it will be capped?
5 MR. BISHOP: Yes, absolutely.
6 There is an underliner and there's an overliner, and
7 the idea is that, you know, just like with the mines, if
8 we can control the amount of water going through those
9 materials, we have created significant more securtity.
10 So we plan to cover it actually with a heavy-duty
11 plastic liner and to recover it with suitable rooting
12 material and revegetate it.
13 MR. RIETEMA: You mentioned that there may be
14 some overflow from this —
15 MR. BISHOP: Yes.
16 MR. RIETEMA: — during these years while it's
17 being filled? Because actually, it's going to be lake
18 or a pond for a while.
19 Where is that on the watershed divide up there? I
20 mean, would that waste that comes out of there flow into
21 this drainage or to the, you know, other side?
22 MR. BISHOP: First of all, it's not a lake;
23 because they have a separate storm water system that
24 takes any water that's impounded, that doesn't come in
25 contact with the waste and discharges, from the area.
16
Upper Tenmile Creek ROD C-118
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 So there's no water that's impounded there. And they
2 put an interim cover on each wintertime, so we're
3 minimizing the amount of water that goes in there.
4 The repository actually straddles the drainage
5 divide, and it's in two counties. It's in a horseshoe
6 shape, and the open side of it is towards Basin Creek.
7 But it really wouldn't flow. I mean, if you look at it,
8 you can see that it's not going to go anywhere.
9 MR. RIETEMA: I wish we could have visited that
10 the day we went up on tour.
11 MR. BISHOP: We could have. As a matter of
12 fact, next summer, if you're still here, I'd be happy to
13 go up and show it to you. And I do have photos and so
14 forth that we could show you, as well.
15 MR. RIETEMA: So that will be capped at the end.
16 MR. BISHOP: Urn-hum.
17 MR. RIETEMA: I was worried about future use,
18 you know, and having trucks hauling material from gas
19 stations and you-name-it.
20 MR. BISHOP: No. No.
21 MS. CANNON: What's the timeline on capping
22 that? Are we talking 5 years, 20 years, 50 years?
23 MR. BISHOP: That's a good question. You know,
24 if you look at the estimate of the number of cubic yards
25 that we have to remove, 245,000 cubic yards, our track
17
Upper Tenmile Creek ROD C-119
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 record here from our existing projects has been about
2 40- to 60,000 cubic yards a year from this watershed.
3 And if we were to go at that rate, we could clean up
4 this site in about 5 years. Recognizing our budget
5 problems, in our document we say five to ten years.
6 But as Craig mentioned, too, we're also - when we
7 sited the Lutrell Repository, the folks in Basin asked
8 that we also clean up their watersheds, if this thing is
9 going to be straddling the divide, and so we have a
10 similar project that's not as far along on that side of
11 the basin. And so next year, we will be at this point
12 where we'll be discussing this sort of a decision
13 process. And again, you know, there are actually more
14 mines on that side than there are on this side. And we
15 will move as rapidly as we can, given both our physical
16 equipment constraints and also our budget constraints.
17 MS. CANNON: So you're saying it will be
18 15 years on the outside, 10 for this side and an
19 additional 5 to catch them up maybe, ballpark?
20 MR. FOX: Maybe ballpark.
21 MS. CANNON: Maybe ballpark, okay.
22 My concern, too, like Steve's, is how long before we
23 actually say, "We're pretty much done, let's cover it up
24 now and vegetate."
25 MR. BISHOP: Well, part of what we want to do is
18
Upper Tenmile Creek ROD C-120
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 do some of that covering and revegetating as we go
2 along. So as we finish up the estimate of the volume of
3 materials that we expect to remove from those mines, we
4 will come up with a final design for the final elevation
5 for that repository, and then from the areas that have
6 been filled up to that point ahead of it, we would close
7 that out. So the idea is we actually move from the
8 furthest-out portion of the repository and move back.
9 And so this revegetation should have a number of
10 years to be in good shape before we actually walk away
11 from it. And again, the State would be backing us up
12 there.
13 MR. FRENCH: Craig French. I wanted to say that
14 the DEQ supports this proposed plan, that we're very
15 much in favor of the four phases of the acid mine
16 drainage treatment, or treatment/ source control plan
17 that EPA has proposed, and we're looking forward to
18 working together to deal with the water issues.
19 MR. BISHOP: You know, if people are going to be
20 shy, one thing, recognizing the State's severe concern
21 about this, and it's been their concern since before we
22 actually listed the site, when we were talking about
23 proposing this site as a national priorities list site,
24 they identified this concern. There's a mine waste
25 technology program that Congress funds to the tune of
19
Upper Tenmile Creek ROD C-121
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 about $5 million a year in Butte, and that program has
2 agreed to, at least for this next year, have as their
3 priority the investigation of techniques that would
4 mitigate these discharges in these small back-country
5 sort of situations.
6 So right now, on their website, they're inviting
7 researchers to move in that direction, and they're
8 inviting them to come and talk to the agency, so that
9 they're resolving problems that are real problems in the
10 field. They're trying to invite processes that are
11 full-scale processes, not just those that would be
12 tested in a laboratory or whatever. And I would think
13 that there would be potential that we would have some of
14 those investigations actually conducted within these
15 watersheds that are here.
16 In addition, in the design work that CDM is
17 initiating, we provided for two demonstrations of some
18 of these treatment technologies. So even though these
19 may not be the final action for a discharge from a mine
20 opening, we're providing funds to at least at two sites
21 to look at some approaches of dealing with it in a
22 low-cost sort of manner. And again, our hope is that we
23 would get into a circumstance where these could be
24 maintained, materials could be changed out maybe every
25 15 years or so. But it's using a variety of approaches
20
Upper Tenmile Creek ROD C-122
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 to using bacteria and so forth to help us knock down the
2 concentrations of metals and try and stay away, to the
3 extent that we can, from the more expensive real package
4 treatment plan sort of circumstances.
5 MR. STEWART: I've got one other thing that I'm
6 curious about. You know, my lawn was sampled last year,
7 and there was a determination on one side that it needed
8 to be replaced. And people came back and now they're
9 re-sampling again, and I don't understand why they
10 couldn't use the samples — I mean, they just dug more
11 holes and more holes, and now they're going up and down
12 the streets and sampling everybody's yards again. And
13 I'm hearing that there's different standards now as to
14 why lawns should be replaced versus others.
15 The other was supposedly a catastrophic, "let's get
16 rid of it now," and now it's more of a "well, we need to
17 look at this again." But I don't know where these
18 standards are coming from. What are the new standards
19 and who establishes those and why?
20 MR. BISHOP: There's a little difference between
21 the programs that we're working with, and the removal
22 program conducts initial cleanups that are the worst
23 sort of circumstances first so that we alleviate those
24 severe threats to either human health or to the stream.
25 And in the circumstance that you are in, the
21
Upper Tenmile Creek ROD C-123
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
1 community — when we were looking at the different mine
2 sites that we were prioritizing, the community had more
3 concern about the Susie Mine, which is right in town,
4 than they did about some of the other mine sites that we
5 were looking at. And so we actually changed that
6 priority to clean up the Susie Mine, and your property
7 is a portion of that mine site. So that's why it was
8 initially undertaken.
9 Our program is meant to be the final cleanup action
10 that occurs. If anything, what we're trying to do is
11 just to make sure that there is no additional cleanup
12 that's needed. And we try to coordinate as best we can
13 with the removal program to have them get in and get out
14 and to be as complete as possible in the cleanups that
15 they do. But our program has — it's not that the
16 standards are necessarily different, it's that — for
17 example, down at the old mill site in the lower part of
18 the canyon, there were some wastes that were left down
19 there, and we're the last program that comes through and
20 tries to see if there's additional work that might need
21 to be done before we leave the area.
22 So that's what's going on.
23 MR. STEWART: What I was told, I was told that
24 the standards are a little different. And what I'm
25 concerned about is that while they were there, they
Upper Tenmile Creek ROD C-124
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
22
1 could have done the whole thing, if it needed to be
2 done, and now they're saying, well, now that we're back,
3 we may need to do it —
4 MR. BISHOP: Well, the only standard that's
5 changed, and I was going to address this, I don't know
6 if you read in your papers the last week or so, the
7 arsenic standard changed. If you'll recall, last
8 January or February, the Clinton Administration, on
9 their way out, changed it and then the Bush
10 Administration decided to take a second look at it.
11 Well, it actually went — and this is the water
12 standard — from 50 micrograms per liter for public
13 drinking water systems down to 10, and I believe that's
14 over a 6-year period.
15 Regardless of the time frame that they're
16 implementing that, our program will implement it right
17 up front, so we have a more difficult standard to meet
18 in terms of water quality in the stream. And I will
19 tell you when we're dealing with this contaminated
20 ground water, it's very difficult to achieve the
21 improvements that we're looking for to actually see
22 those improvements in the stream. So we've got to be
23 pretty thorough about our work.
24 You know, my hope is that we're not going to tear
25 your yard up again. But we're trying to be as complete
Upper Tenmile Creek ROD C-125
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
23
1 as possible, is all I can say.
2 MR. MARSH: Let me just add a little bit about
3 that, Sam. The sampling that we did a year and a half
4 ago, as part of the remedial investigation, was
5 essentially a screening sampling, where we took one,
6 sometimes a couple of samples per yard, just to see what
7 the levels of lead and arsenic were in the yard
8 primarily.
9 What we're doing now is going back in as part of our
10 design effort, and from the initial sampling we did, we
11 found that, yes, there were levels of concern in
12 approximately 80 percent of the houses. We didn't
13 sample that many houses then. Now we're trying to go
14 back in and sample all the yards, and we're sampling
15 quadrants of yards or parts of yards to see actually
16 what would have to be removed in order to achieve the
17 cleanup standards that EPA will be setting in the record
18 of decision.
19 So it's really kind of a two-phase process, and
20 we're in the second phase of that process now. That's
21 why we're going back to some of the same yards.
22 MR. STEWART: I guess I've got to go back to the
23 road thing again, sorry. But there is a $150,000
24 difference between digging up 18 inches and capping it.
25 And I guess my concern is, what's $150,000 worth of
Upper Tenmile Creek ROD C-126
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
24
1 aggravation when somebody comes in here and tears up the
2 road and there's dust everywhere, and it just makes a
3 mess out of the town of Rimini while they're doing this?
4 And I hope that that is a part of the consideration in
5 the remedial action that is necessary.
6 MR. BISHOP: It is, and, you know, your concern
7 specifically has been a discussion of considerable — or
8 a topic of considerable discussion, and we will share
9 those cost figures with you. But again, as you guys
10 meet together as a community, please let us know before
11 this comment period closes, you know, if you can come to
12 some common recommendation —
13 MR. STEWART: Well, I haven't seen any Rimini
14 meetings in the near future, and especially by the time
15 that your November 21st date is up. And I'm coming on
16 record now saying that I feel that this is a real
17 aggravation, and I personally would rather see a capping
18 rather than going through this big process of tearing
19 through the town.
20 And I don't know — What concerns me is that all of
21 a sudden, decisions are made, and I like to be a part of
22 them, if I can. And I want to be a part of it now and
23 go on the record, and if other people in this community
24 are in disagreement, I hope that they'll say it now.
25 Because I don't know what's said over the Internet to
Upper Tenmile Creek ROD C-127
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
25
1 you on your e-mail. And if you want me to, I will go on
2 the e-mail record as well. But I just want to say that
3 I don't see a community forum before that. And if there
4 is, good. I hope so.
5 But if people have a difference of opinion, then,
6 you know, I'd like to hear it now.
7 MR. BISHOP: Chuck.
8 MR. WAITERS: Chuck Walters. On that issue, May
9 and I have been talking, and we are going to call a
10 community meeting, and hopefully we're going to —
11 hopefully it is going to be before our due date of the
12 21st, because we have a lot of issues to discuss. We
13 have to discuss, as a community, this potable water
14 system, and the paving of this lower road and the paving
15 trough town is an issue that we're going to discuss. I
16 mean, if we really want to go on the record now, I've
17 been talking with some people in town, and right now,
18 people aren't sure what they want. I've only talked to
19 a few. But there's several people that are completely
20 against paving in town and, of course, completely
21 against paving the lower road, too.
22 But we are going to have a meeting, and that's one
23 of the things May and I are going to discuss tonight.
24 MR. BISHOP: I want to make sure people realize,
25 the lower portion of the valley paving up to Chessman
Upper Tenmile Creek ROD C-128
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
26
1 Reservoir is nothing to do with our work.
2 MS. CANNON: So how will that be assessed? Is
3 that a RID?
4 MR. BISHOP: No.
5 MS. CANNON: Who is going to cover that one?
6 MR. BISHOP: I believe federal highway funds.
7 And you might talk to the Forest Service. It's a forest
8 improvement road of some sort. But there were funds
9 obtained by Congress to cover that. And if you have
10 concerns about that, and I know people do, you need to
11 be speaking with, I think, Department of Transportation
12 and probably Federal Highway Administration.
13 MR. WAITERS: Well, Eric Griffin, the County
14 Road Supervisor, we had a meeting on this road here
15 about a month ago, and he was going to hold - call and
16 hold some public meetings up here to discuss that paving
17 job. And I think it's maybe time we call him and get a
18 meeting going on, because they're already serving it.
19 But what it was, when we had this meeting, he said
20 even if it goes through, it's going to be like five
21 years from now. But the main guy from the Federal
22 Highway Department that was there said, because I asked
23 the question what's driving this and how do you
24 substantiate it, and he says, "Well, one thing is it's
25 traffic count." Well, when they got to talking, there
Upper Tenmile Creek ROD C-129
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
27
1 is no traffic count. So they're supposed to put in
2 traffic counters.
3 And he also made the comment, he says, "Now, if the
4 people in this area don't want this," and I can quote
5 this from him, he says, "we want to know because we
6 don't want to waste our time doing all this engineering
7 if the whole community is against it."
8 Originally when they proposed this, I think the
9 people in the community thought it was just going to be
10 a paving like Colorado Gulch. But now what's really
11 happening is this is going to be a major highway.
12 Because what it is, it's federal funds that were tagged
13 to build a highway that could be used for fire control
14 access. The problem is it has to be built to this high
15 state standard.
16 MR. STEWART: Well, you know, this is not an EPA
17 issue and we shouldn't be discussing it tonight, but I
18 do think that we definitely need a meeting of the Rimini
19 residents to discuss this, and it's very important. And
20 when you say "we discussed this with Eric Griffin," I
21 don't know who "we" were. And this is something that
22 I'm concerned about -
23 MR. WATTERS: That's why we're going to have
24 this meeting here, Sam.
25 MR. STEWART: Great.
Upper Tenmile Creek ROD C-130
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
28
1 MR. WAITERS: You're on the list to be called.
2 MR. STEWART: Cool.
3 MR. BISHOP: I don't want to keep people here
4 any longer than they want to be here. Things are kind
5 of winding down.
6 I appreciate everybody's willingness to come out
7 tonight, and if you think about things between now and
8 Tuesday, please come to our meeting at the Holiday Inn
9 downtown at 6:30 in the evening. If you have any
10 questions, give me a call. We will be at that location
11 at 5:30 again, if people have questions that you want to
12 talk over. And also, you know, letters, e-mails,
13 whatever other means you want, too, we' d be happy to
14 receive those.
15 So thank you.
16 (The proceedings were concluded at 7:50 p.m.)
jy *********
18
19
20
21
22
23
24
25
Upper Tenmile Creek ROD C-131
-------
Proposed Plan Public Hearing, Rimini, MT- November 8, 2001 Response
29
COURT REPORTER'S CERTIFICATE
STATE OF MONTANA )
ss.
COUNTY OF JEFFERSON )
I, CHERYL ROMSA, Court Reporter, Notary Public
in and for the County of Jefferson, State of Montana, do
hereby certify:
That the foregoing proceedings were reported by
me in shorthand and later transcribed into typewriting;
and that the -29- pages contain a true record of the
proceedings to the best of my ability.
IN WITNESS WHEREOF, I have hereunto set my hand
and affixed my notarial seal this 19th day of November 2001.
CHERYL ROMSA
Court Reporter - Notary Public
My Commission Expires 8/4/03
Upper Tenmile Creek ROD C-132
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
BEFORE THE ENVIRONMENTAL PROTECTION AGENCY
PUBLIC HEARING ON THE PROPOSED PLAN
UPPER TENMILE CREEK MINING AREA SITE
LEWIS AND CLARK COUNTY, MONTANA
TRANSCRIPT OF THE PROCEEDINGS
Heard Before Mike Bishop, EPA Project Manager
Holiday Inn, Elkhorn Room, Helena Montana
November 13, 2001
7:13 p.m.
REPORTED BY: CHERYL ROMSA
CHERYL ROMSA COURT REPORTING
P.O. BOX 1278
HELENA, MONTANA 59624
(406)449-6380
Upper Tenmile Creek ROD C-133
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
INDEX
PAGE
Discussion of meeting with lower watershed
residents 5
Discussion of education and restrictions re
developing reclaimed land 6
Discussion of meeting re wildlife issues 13
COURT REPORTER'S CERTIFICATE 21
Upper Tenmile Creek ROD C-134
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001
Response
1 WHEREUPON, the following proceedings were had:
2 (An overview of the plan was presented by
3 Mike Bishop.)
4 MR. BISHOP: At this point, feel free to
5 comment. And again, the format that we had last time
6 was kind of a question-and-answer, and we don't
7 necessarily have to do that if you just want to comment.
8 But if you do want to ask questions, I'd be happy to
9 answer them, to the extent I could, as well.
10 MR. POSEWITZ: Mike, if we've already sent a
11 written comment in, there's no real need to repeat any
12 of that.
13 MR. BISHOP: That's right. But we can have a
14 discussion, if you'd like, you know, about any of your
15 comments.
16 For example, comments that we've heard from Jim and
17 his group deal with these aspects of the roads and the
18 access and the effect on the wildlife. And we do have a
19 meeting set up for the 27th that would be facilitated,
20 and it will include many of the agencies and the hunter
21 and wildlife groups to try and sit down and dialogue on
22 this issue.
23 And frankly, in the responsiveness summary, I'm not
24 quite sure how to respond to their concerns. Because
25 our program allows us to create these developments in
The format of this meeting was primarily open discussion and
question and answer. EPA's responses to most comments are
provided directly in the discussion and are not repeated in this
column. Clarifications are noted in this column if necessary.
Upper Tenmile Creek ROD
C-135
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 order to do the cleanup work that we need to do, but by
2 the same token, I think all of the agencies involved
3 recognize some of the concerns that these groups are
4 identifying. And I think if we all come together and
5 try and identify our roles, we can contribute different
6 aspects to deal with the concerns that they have. And
7 frankly, from our perspective, to the extent that they
8 could possibly help with conservation easements and
9 those sorts of things to close up some of these areas
10 where property owners may be amenable to allowing that
11 sort of ongoing use to be inserted, I think we would
12 like to work with these groups as well.
13 And many of the landowners that we're dealing with
14 are in absentia. Many of them haven't seen the
15 properties that they own. Some of them, their ancestors
16 developed them, and I doubt very much they have an
17 interest in developing them. And so I think by bringing
18 many of our ideas and our abilities together, we can
19 address some of these concerns as we go through the
20 Superfund process.
21 And I guess the message that I would like to leave
22 you guys with, whether now or in the later stages of
23 this process, is that Superfund is an open process and
24 we try to be as reactive as we can. Our law does allow
25 us to be fairly responsive, so we don't have to go
Upper Tenmile Creek ROD C-136
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 through some of the permitting hoops that you might
2 otherwise have to go through. Our process is meant to
3 be a surrogate for the National Environmental Policy
4 Act, so we don't do impact statements and those sorts of
5 things. So if you do have concerns, continue to bring
6 them to us and we'll do our best to try and bring some
7 attention to them.
8 Kathy, I was just curious, I know you must be here
9 to some extent representing the Lower Tenmile folks
10 there. Do they seem to be out of the loop as far as
11 what's going on and do they have concerns and a desire
12 to meet with us?
13 MS. LEIK: Well, actually, I actually just met
14 with your representative Friday, and I haven't talked to
15 any of the other neighbors. I just couldn't go up to
16 Rimini that night, so I just came to give myself some
17 background before we had the local meeting.
18 MR. BISHOP: Right.
19 MS. LEIK: So I'm not a very good resource as to
20 how the other people feel.
21 MR. BISHOP: And just so we have some record,
22 our dialogue with Helen Cannon at the last meeting was
23 that we would try to get together a small neighborhood
24 meeting with the lower watershed group to just give them
25 the courtesy of explaining in more detail, just like we
Upper Tenmile Creek ROD C-137
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 did this evening, what we're up to and trying to hear
2 their specific concerns, if there are some.
3 MS. LEIK: One of the concerns I had, when the
4 EPA did the initial, say, reclamation, they removed, in
5 the Lower Tenmile — like in the land adjoining mine,
6 there was an old mill. I'm not probably stating the
7 correct name for it, but they had dams, you know.
8 MR. BISHOP: Tailings impoundments, right.
9 MS. LEIK: It looked like, you know, Mammoth up
10 at Yellowstone Park, that whole gully. So they dug it
11 out and replaced it with beautiful — and it looks —
12 they did a very nice job. This was about '89, "90. And
13 everybody really welcomed that because of the
14 contamination. It was a large area.
15 But what concerned me, then afterward, when the
16 people that own that — It was private land that was
17 reclaimed, and then a few years ago when that came up
18 for sale, another neighbor and I commented, you know, to
19 the County Land Board that we had concerns about them
20 dividing that land up and somebody building over this
21 waste site. Because, you know, a person coming in
22 there, not knowing, would think it looked like perfectly
23 good land. But if they dug a well there, you can
24 imagine, into that old dredge, you know, where there was
25 arsenic, cadmium, and lead, and there was no vegetation,
Upper Tenmile Creek ROD C-138
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 etcetera, well, if somebody dug a well in there.
2 And then on the side hills, they pointed out to me
3 when they did the reclamation — I was concerned about
4 my land being contaminated, so I had some conversations
5 with them at the time, and they pointed out to me how
6 the wind, being in a westerly direction, had blown this
7 waste up on the side hills of that gully, and there was
8 no vegetation there. Well, kids playing in that, again,
9 would be playing, you know, just like in East Helena,
10 where it's contaminated soil.
11 But what I found out when they were dividing that
12 land from the County Planning, that there were no
13 riders on that land. I mean, there was nothing that
14 told anybody what was under it.
15 In fact, one person on another piece close to me
16 actually bought a piece of the reclaimed land and then
17 built a house, and they didn't realize, because of
18 course, the person selling the land didn't tell them.
19 And then they found out, when you came back with the
20 second study there, that their land was contaminated.
21 And again, they have little kids. And, you know, they
22 weren't rich people or, say, people that could really
23 afford to do very much with this few acres that they
24 had.
25 So anyway, all this time, we've been concerned as to
Upper Tenmile Creek ROD C-139
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 if you can't put riders, or whatever you would do —
2 that's probably not the right term for it, but when the
3 people bought the land when it came up for sale, that
4 they would know what was under there.
5 MR. BISHOP: Sure.
6 MS. LEIK: For their health.
7 MR. BISHOP: We have had discussions with the
8 County about having some mechanism to accomplish what
9 you're concerned about.
10 Mike, I don't know if you want to respond.
11 MR. McHUGH: It was the Department of State
12 Lands, the Abandoned Mine Bureau, that did the
13 reclamation on that site, and at that time, they could
14 have placed covenants or notification requirements on
15 it. The County had nothing to do with the division of
16 that land. All that was exempt, using the 20-acre
17 exemption and the family transfer.
18 We're very aware of the problems that you're talking
19 about. I know at least one case where people came and
20 dug up everything and put in a basement; now their kids
21 have elevated lead levels.
22 MS. LEIK: Right. That's the one place I was
23 mentioning.
24 MR. McHUGH: And we've tried to - We've had
25 several other proposed subdivisions in that area, and
Upper Tenmile Creek ROD C-140
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 the people have actually withdrawn their subdivision
2 application because of all the notification requirements
3 and building site restrictions that the County was going
4 to place on them; and then they've utilized other
5 exemptions, like family transfer exemptions, that the
6 County has no way to place — It would be nice to place
7 institutional controls at least that would require
8 property owners — you have to rely on the integrity of
9 the realtors and the integrity of the developers and the
10 landowners right now.
11 MS. LEIK: Right. And there's about six parcels
12 there that were 20-acre parcels that the back side goes
13 from Elk Trail. You're probably familiar with it.
14 MR. McHUGH: Yeah.
15 MS. LEIK: And of course, these are long,
16 rectangular 20-acre parcels. And so the only the
17 logical way to divide that, by covenants, they can
18 divide into 10.1 know which one you're talking about,
19 where they used the family — because the County did
20 stop them from another, from the road issue. But
21 there's about six more parcels there that could all be
22 divided in half. And of course, the half that the
23 people would want — they're all built on that
24 Deer Meadow, so of course, where they would want to
25 build an access is from Elk Trail, and that would all be
Upper Tenmile Creek ROD C-141
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 right in the —
2 MR. McHUGH: The tailings ponds area.
3 MS. LEIK: -- with that tailing ponds.
4 MR. McHUGH: I know. We're very worried about
5 it, but unless they come in for subdivision review, the
6 County has very limited things to do. I mean, we try to
7 work with the homeowners association in doing
8 notifications and trying to establish some institutional
9 controls, but we can't force them to do it. So it's
10 buyer beware.
11 MS. LEIK: Like I say, there's six or seven, and
12 then with the land —
13 MR. BISHOP: That is something, though, that I
14 think we can help institute, Mike.
15 And I had mentioned to him that our attorney in
16 Denver, some of her colleagues had just been to one of
17 these seminars on institutional controls, what's the
18 best way to do this, do we put a notification on the
19 deed, do we — you know, I'm not sure what the best
20 method would be. But we do want to engage in some
21 conversations about this so that we try to prevent that
22 circumstance where people would dig into it and unearth
23 it and create a problem all over again.
24 And also, with respect to water, when we put in a
25 ground water control area, we will have to do it in such
10
Upper Tenmile Creek ROD C-142
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 a way that people are aware of the concerns in the
2 general area and that at a minimum, they analyze their
3 waters before they begin to use them as a potable water
4 supply and are aware that there may be some need for
5 water treatment and that sort of thing.
6 But you're right, we can't just walk away and hope
7 that it will remain effective.
8 MS. LEIK: Fortunately, that land hasn't been
9 divided up, except for that one plot, but, you know,
10 with the price of land, I can see it's just a matter of
11 a few years before people do split their land.
12 MR. McHUGH: There is an effort under way right
13 now to do a Lower Tenmile watershed group similar to the
14 Upper Tenmile. And I think if we can bring the
15 information to people, they'll be more aware of the
16 problems that you have in that area. So that may be a
17 good thing.
18 The Health Department is thinking, in conjunction
19 with the remediation work that the EPA is doing in the
20 Rimini area, about having an education liaison that
21 would come up to people and hand out — you know, go
22 door to door and hand out pamphlets, offer testing, and
23 things like that. So that may be another mechanism that
24 could bring up the knowledge level there.
25 MS. LEIK: Right.
11
Upper Tenmile Creek ROD C-143
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 And it's kind of like East Helena, even though I
2 know that one place that was divided, you know, those
3 kids could play on that side hill where there is no
4 vegetation, and it looks perfectly fine. But that
5 gentleman didn't seem concerned at all when Mike Cannon
6 and I talked to him about it at one of our association
7 meetings. It was kind of like, oh, well.
8 I mean, to us there was a real threat to his
9 children.
10 MR. McHUGH: Well, that's part of the reason the
11 County recommended denial of that subdivision, but then
12 they took the end run on it.
13 MS. LEIK: Right.
14 I guess there's nothing you can do about the people
15 if they don't recognize the problem.
16 I'm sorry to take so much time on that one issue,
17 but it really bothered me. Because I was so grateful
18 the EPA came and reclaimed that area. I mean, it was
19 wonderful, because it was blowing all over and
20 contaminating everything and contaminating
21 Tenmile Creek. So I was thankful that they reclaimed
22 it. I just assumed that there would be riders on the
23 land or some...
24 MR. BISHOP: And that sort of thing is left to
25 our program, and that's the difference between our
12
Upper Tenmile Creek ROD C-144
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 removal and remedial program. So we will be striving to
2 try and deal with that. And you didn't take too much
3 time.
4 I was just thinking that we haven't been hearing
5 very much here, and we've taken the time to assemble
6 this meeting.
7 Jim, I was going to put you on the hot seat a little
8 bit. This upcoming meeting that we have on the 27th,
9 can you lead us in some direction as to how you think
10 that might be organized or—
11 MR. POSEWITZ: Okay. I think, first of all, for
12 the record, we certainly appreciate the way EPA has
13 responded to everything that we have brought up as far
14 as an issue or a commentary. And the meeting on the
15 27th is to continue to address our concerns about
16 preserving as much wildlife habitat and wildlife habitat
17 security in the Tenmile Drainage as is possible when we
18 go through this process.
19 Our concern was further heightened by realizing that
20 we're talking about a lot of public land ownership in a
21 watershed and that the ultimate road configuration, road
22 density, and road standards are going to be the
23 long-term responsibility, purview of the United States
24 Forest Service. And so what we wanted to talk about on
25 the 27th of November was to see if we had a common goal
13
Upper Tenmile Creek ROD C-145
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 for what — or a common objective for what we wanted the
2 Tenmile watershed to look like when EPA was finished and
3 when it was going into the long-term custodial care of
4 the National Forest Service. And why we wanted to
5 address that while the EPA was still active and present
6 is because of the resources EPA brings to the landscape.
7 And those are resources that can leave us with problems
8 or those are resources that can become part of the
9 solution.
10 So I think the meeting of the 27th will be a key one
11 for us to see if we can come to a consensus on what we
12 want the ultimate future long-range condition of the
13 Tenmile watershed to look like. It's something that we
14 deal with in the forest planning process. It's
15 something that for species like elk, we have a very
16 strong database to know what is conducive for elk
17 habitat, elk security, and the kind of elk seasons that
18 have been traditionally part of the Montana hunting
19 heritage. And so we don't want to be left with a future
20 condition for a lot of activity up there. And this
21 activity again focuses, in our minds, a lot on roads and
22 what might be — what we might construe as excessive
23 access to properties that, by virtue of time and just
24 the natural evolution of things, became isolated tracts
25 that did not have a lot of human activity in them.
14
Upper Tenmile Creek ROD C-146
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 MR. BISHOP: Right.
2 MR. POSEWITZ: Now they're being accessed again,
3 and thus our concern.
4 The other item, on the Travis site, again, we're
5 quite pleased with the EPA's response to looking for
6 alternatives to sacrificing that meadow for a water
7 supply augmentation component. And we feel that that
8 particular site, even though it's not an aboriginal
9 circumstance, it certainly is a circumstance conducive
10 to a lot of wildlife species and a lot of vegetation
11 diversity. And again, in this context, we look at the
12 Tenmile watershed as part of a larger wildlands resource
13 that basically stretches from the Yellowstone on up into
14 Glacier and into Canada. And here, I guess calling
15 EPA's and the Forest Service's attention to this
16 evolving body of science that said you need connecting
17 corridors between isolated components of critical
18 wildlife habitat; and one of the connecting corridors
19 that is normally identified in these scientific reports
20 has to do with coming down the Continental Divide.
21 And if you look at the juxtaposition of
22 Tenmile Creek, the Boulder reclamation that's also in
23 the future, the new planning start that's been initiated
24 on the Little Blackfoot side, that is a very fragile
25 component of a wildlife corridor reaching from Glacier
15
Upper Tenmile Creek ROD C-147
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 to Yellowstone, for example. So we think it has got
2 wildlife values and wildlife importance that go beyond
3 just the local circumstance of us elk hunters liking to
4 have isolated tracts of wild land to hunt in.
5 And again, I guess concluding with the fact that we
6 appreciate how responsive EPA has been to our raising
7 these issues.
8 MR. BISHOP: Something that I would like to
9 maybe pry out of you is, there seems to be some history
10 of previous discussion on this topic that, you know, I
11 think recognizing the concerns that you've stated is one
12 thing, but there seems to be a political aspect or
13 something to this issue that I feel maybe a little naive
14 going into this meeting on the 27th.
15 MR. POSEWITZ: I don't think there's anything
16 hidden here. I mean, if you're looking at —
17 MR. BISHOP: I don't mean anything hidden. Are
18 there issues that have been previously — bridges that
19 have been crossed that would give us some insight as to
20 how to approach this topic at this point?
21 MR. POSEWITZ: Well, I guess previous
22 discussions that involve this particular landscape, if
23 you look at the forest plan, road density
24 recommendations that are in the forest plan, if there is
25 some residual baggage from those discussions and
16
Upper Tenmile Creek ROD C-148
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 planning processes, it would be that the forest road
2 network is not consistent with the forest plan. And
3 that has to do with a lot of things, like the way
4 Congress appropriates money for reading and logging
5 where Congress didn't appropriate money for other
6 things. And there's probably a long and, oh, diverse
7 history to some of those areas, and not just in Tenmile
8 Creek. I mean, that would be the headwaters of Little
9 Blackfoot and it would be Travis Creek and Lump Gulch.
10 I mean, any part of Helena National Forest, there are
11 components of that that are inconsistent with the forest
12 plan.
13 We are engaged with the Forest Service, talking
14 about motorized recreation. And that particular Tenmile
15 watershed has got a lot of old mining roads that are
16 being used for motorized recreation, and there's
17 discussions on what, if any, degree we want the
18 Forest Service to address that. We realize that's not
19 part of the EPA issue at all. I mean, that's the
20 residual problem, and it doesn't have much to do with
21 your remedial program.
22 You go over the ridge on Black Mountain, and there
23 is a wilderness candidate, wilderness study area. It's
24 sort of in protective custody now, but that will be
25 another big public issue when that rolls around. But
17
Upper Tenmile Creek ROD C-149
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 the reality is that you ball these things together, some
2 areas with struggles and some with some degree of
3 security, you represent an exceptional wildlife
4 resource.
5 MR. BISHOP: There's no legal challenge or
6 anything that's clouding the issue at this point, is
7 there?
8 MR. POSEWITZ: No, there's none clouding the
9 issue, but now the Forest Service also has got to come
10 out with lynx guidelines. And so all of the sudden,
11 you're into the question of T&E species, with lynx,
12 wolves, wolverines, grizzly bears. And if you ascribe
13 to the corridor importance, all those things become
14 relevant.
15 We have not raised those as issues because of - we
16 think we're getting a good response with the simple
17 approach of trying to preserve elk habitat, quality
18 hunting environments, relatively wild lands; and that if
19 we can hold onto that concept — I mean, I think the
20 other idea of bringing in a T&E argument would be not
21 conducive to the process where we have repeatedly stated
22 we are in sync with your objectives.
23 We think what you're doing up there for Rimini and
24 for the water supply and for the mine cleanup is very
25 important stuff, and we're satisfied with the response
18
Upper Tenmile Creek ROD C-150
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 we're getting to our concerns. And granted, those other
2 issues are sitting out there like in a fog bank or a
3 cloud, but speaking for the Helena Hunters & Anglers, I
4 don't think we're going to raise those issues, because
5 we don't want to complicate the process. We want to see
6 that this continues to do what we think is a good idea:
7 Cleaning up as much of that as we can afford to clean
8 up, and do it now without a great delay getting into
9 some kind of a litigative cycle over grizzly bears, for
10 example.
11 MR. BISHOP: No. The Fish & Wildlife Service
12 has raised concerns about lynx, and we have tried to be
13 somewhat sensitive to them. And we are actually looking
14 to some extent about the potential for cadmium to
15 accumulate in them from some of these materials. We can
16 talk about that some other time.
17 But I just — since we're all out tonight, I thought
18 I would try and use your time effectively.
19 MR. POSEWITZ: Sure. I appreciate that.
20 MR. BISHOP: Are there other comments or
21 concerns?
22 And we let a gentleman slip away here. I'm not even
23 sure who that was, that was over in the corner there. I
24 meant to ask him as well.
25 I would like to thank you for coming out tonight.
19
Upper Tenmile Creek ROD C-151
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
1 And again, I do look forward to working with you and the
2 groups that you represent in a forward-looking sense.
3 To the extent that you continue to have concerns, let's
4 get together and see if we can deal with them.
5 Thank you very much.
6 (The proceedings were concluded at 7:40 p.m.)
7 *********
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
20
Upper Tenmile Creek ROD C-152
-------
Proposed Plan Public Hearing, Helena, MT- November 13, 2001 Response
COURT REPORTER'S CERTIFICATE
STATE OF MONTANA )
ss.
COUNTY OF JEFFERSON )
I, CHERYL ROMSA, Court Reporter, Notary Public
in and for the County of Jefferson, State of Montana, do
hereby certify:
That the foregoing proceedings were reported by
me in shorthand and later transcribed into typewriting;
and that the -20- pages contain a true record of the
proceedings to the best of my ability.
IN WITNESS WHEREOF, I have hereunto set my hand
and affixed my notarial seal this 19th day of November
2001.
CHERYL ROMSA
Court Reporter - Notary Public
My Commission Expires 8/4/03
21
Upper Tenmile Creek ROD C-153
-------
Appendix D
Basin Creek Mine Reclamation
Responsibilities
-------
Basin Creek Mining, Inc.
P.O. Box 180
Basin, MT 59631
March 4, 2002
Department of Environmental Quality
Permitting and Compliance Division
P.O. Box 200901
Helena, MT 59620-0901
Mr. Pat Plantenberg
Re: Minor Revision 01- 001, Operating Permit 00132
Additional Revisions to Reclamation Status Map for the Record of Decision
Dear Mr. Plantenberg:
Per our recent conversation, I have again revised the Reclamation Status Map and
corresponding Reclamation Status Spreadsheet. These revisions are additional to the
revisions on the February 6, 2002 correspondence between BCMI and the DEQ. There
were two changes to the Reclamation Status Map and Spreadsheet as listed below:
Area Acreage Description of Change
38.1 0.5 Historic mining road from SP08 to a gate on the NW
portion of the Operating Permit Boundary.
Reclamation responsibility transferred from EPA to
BCMI.
66 0.8 Access road in the Fisher Park area. Reclamation
responsibility transferred from EPA to BCMI.
Total 1.3 acres
The changes were made after consultation with the Trustee (Kelvin Buchanan), the
DEQ (Pat Plantenberg), the EPA (Steve Way and Mike Bishop), and BCMI (Dan
Adams). The primary reason for the reclamation responsibility transfer is that the EPA
has now rejected these areas as possible haul routes for historic mine waste. At the
inception of the Repository, the EPA was considering these areas as possible haul
routes.
d:\02regag\rclrev1 .wpd
-------
Also included on the Reclamation Status Map are the locations of the current MPDES
Outfalls and the proposed MPDES Outfalls. The Map and Spreadsheet are now
accurate and will suffice as Exhibits to the Record of Decision.
If you have any questions or require further information please contact me at 459-0546.
Sincerely,
Daniel B. Adams
BCMI Site Manager
Enclosure: Reclamation Status Map
Reclamation Status Spreadsheet
cc: Kelvin Buchanan (Trustee)
Steve Way (EPA)
Mike Bishop (EPA)
-------
March 4, 2002
BASIN CREEK MINE
OPERATING PERMIT No. 00132
Area
1
2
2.1
3
3a
3.1
3.2
4
5
5.1
6
7
8
9
10
11
11.1
11.2
12
12.1
12a
12b
13
14
15
16
17
BCMI
Reclamation
Completed
Acres
2.5
14.3
0.2
30.6
1.3
0.4
3.8
0.4
0.4
6.2
9.7
2
4.1
1.1
9.5
1.3
0.4
0.6
EPA
Reclamation Completed by
BCMI Prior to Repository Startup
Acres
4
15.7
0.3
0.1
0.1
BCMI
Reclamation
Not Completed
Acres
EPA
Reclamation
Responsibility
Acres
0.8
21.7
0.5
0.4
0.3
Minesite Location
Luttrell Peak
Block B
Block B North
Upper Waste Repository Removal Area
Middle Waste Repository Removal Area
Columbia Tailings
Malf. Jet. Monitor Well Road
Luttrell Ridge
Luttrell Ridge
Luttrell Ridge
Luttrell Ridge
Luttrell Pit
West Luttrell Ridge
West Luttrell Ridge
Malfunction Junction
Luttrell Pit East
Luttrell Pit East
Rimini Road below Repository
South Luttrell Ridge
South Luttrell Ridge
South Luttrell Ridge
South Luttrell Ridge
Haul Road
Haul Road
Haul Road/Drill Road
Lower Venus
Mine Entrance
02regag/bndsum3.wk4
-------
March 4, 2002
BASIN CREEK MINE
OPERATING PERMIT No. 00132
Area
18
19
20
21
22
22a
23
24
25
26
26a
26.1
27
27.1
27.2
28
29
30
30.1
31
31.1
32
32.1
33
34
35
BCMI
Reclamation
Completed
Acres
0.7
0.1
0.3
0.2
0.5
0.4
1
5.5
3.9
0.3
2.6
25.4
4.5
5.7
5
1
3.9
0.4
0.5
0.3
EPA
Reclamation Completed by
BCMI Prior to Repository Startup
Acres
BCMI
Reclamation
Not Completed
Acres
1.5
0.5
0.6
EPA
Reclamation
Responsibility
Acres
0.5
1.4
0.9
Minesite Location
Mine Entrance
Administration Building
Administration Building
Mine Entrance
Mine Entrance
Water Tank Access Road
Bypass Road
LP3/Bypass Road
Process Pond Impoundment
LP1 Impoundment
LP1 Overflow
LP1 Impoundment
LP1
LP1 Perimeter Road
Rimini-Elliston Wagon Road
Fisher Park East
Fisher Park West
LP1 North
Haul Road by Truck Shop
Truck Shop North
P. Pit Upper Access Road
Paupers Peak
Paupers Peak
Paupers Peak Road
Paupers Peak Road
Paupers Peak Road
02regag/bndsum3.wk4
-------
March 4, 2002
BASIN CREEK MINE
OPERATING PERMIT No. 00132
Area
35.1
35.2
36
36.1
37
37.1
38
38.1
39
40
41
42
43
43.1
44
45
47
47.1
48
48a
48 b
48.1
48.2
48.3
49
49.1 a
BCMI
Reclamation
Completed
Acres
0.1
0.8
0.8
1.7
0.6
0.7
0.3
28.9
7.2
13.1
10
0.2
3.9
14.4
0.9
EPA
Reclamation Completed by
BCMI Prior to Repository Startup
Acres
BCMI
Reclamation
Not Completed
Acres
0.1
0.8
0.5
1.9
0.3
0.9
1.8
EPA
Reclamation
Responsibility
Acres
0.2
n/a
0.8
20.7
Minesite Location
Paupers Pit North
Paupers Pit North
Monitor Creek Headwaters
Monitor Creek Headwaters
SP8 Entrance
SP8 Road
Monitor Creek Restoration
Monitor Creek Road
OpenCut Permit # 00598
T5 Entrance
Solution Corridor
LP3 North
SP9 West
LP3 West Ditch
LP3 Ginset
LP3 North
LP3
LP3 Cover Area
Upper Paupers Pit
Middle Paupers Pit
Upper Paupers Pit
P. Pit Haul Road
Upper Paupers Pit
Lower Paupers Pit
Lower Waste Repository Removal Area
Waste Repository Removal Area Toe
02regag/bndsum3.wk4
-------
March 4, 2002
BASIN CREEK MINE
OPERATING PERMIT No. 00132
Area
50
50. b
50.1
51
51a
52
53
53.1
54
55
55.1
56
57
58
58.1
58.2
59
60
60.1
61
62
62.1
63
64
64.1
65
66
66.1
BCMI
Reclamation
Completed
Acres
1.7
5.8
3.9
2.7
0.4
0.1
0.5
5
0.3
EPA
Reclamation Completed by
BCMI Prior to Repository Startup
Acres
BCMI
Reclamation
Not Completed
Acres
0.2
1.2
0.9
5
1
0.5
0.1
0.4
0.8
EPA
Reclamation
Responsibility
Acres
2.7
0.6
2.7
6
0.7
0.4
3.2
1.6
0.3
0.5
Minesite Location
SP02 Dike
LP3 East Perimeter Ditch
LP3 East Perimeter Road
Haul Road; SP2, SP3, SP4 roads
Haul Road above Switchback
SP1/Admin
T1-Topsoil Stockpile Area
LP1 East Access Road
T2 Topsoil Stockpile
T5 Topsoil Stockpile
T5 Topsoil Stockpile
SP5 East
Truck Shop
Malfunction Junction
Malfunction Junction
Malfunction Junction
SP8 Impoundment
Boneyard
Bioreactor Pilot Test
Paupers Peak
Paupers Peak
Paupers Peak
Paupers Peak
ISS2 Access Road
Paupers Peak
Fisher Park
LP1 East Road
02regag/bndsum3.wk4
-------
March 4, 2002
BASIN CREEK MINE
OPERATING PERMIT No. 00132
Area
67
67a
68
68.1
69
70
71
72
73
74
75
75.1
76
77
78
79
80
80.1
81
81.1
82
83
84
TOTAL
BCMI
Reclamation
Completed
Acres
1.2
0.3
0.2
0.5
1.2
258.4
EPA
Reclamation Completed by
BCMI Prior to Repository Startup
Acres
20.2
BCMI
Reclamation
Not Completed
Acres
0.7
2
0.8
1.2
2
25.7
EPA
Reclamation
Responsibility
Acres
1.0
0.7
1.4
0.6
1.8
0.3
0.4
0.4
0.3
0.5
0.2
0.2
0.2
0.5
74.5
378.8
Minesite Location
LAD2 Road
Luttrell Ridge Road
Luttrell Pit West Road
Luttrell Pit Haul Road
Luttrell Pit Haul Road
Luttrell Pit Haul Road
Luttrell Pit Haul Road
Admin
SP2
SP3
SP3 and SP4 Impoundments
SP4
SP5
SP6
SP8
SP9
SP9 Access Road
SP10
SP10 Access Road
East Process Pond
West Process Pond
Paupers Pond
TOTAL
Total Acreage Disturbed
02regag/bndsum3.wk4
------- |