EPA/ROD/R10-02/032
2002
EPA Superfund
Record of Decision:
BUNKER HILL MINING & METALLURGICAL
COMPLEX
EPA ID: IDD048340921
OU 03
SMELTERVILLE, ID
09/12/2002
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THE BUNKER HILL MINING AND
METALLURGICAL COMPLEX
OPERABLE UNIT 3
Record of Decision
September 2002
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PART 1
DECLARATION
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 1
PART 1
DECLARATION
1.0 SITE NAME AND LOCATION
The Bunker Hill Mining and Metallurgical Complex Superfund Facility, located in the Coeur
d'Alene Basin (the Basin), was listed on the National Priorities List (NPL) in 1983. The NPL
facility has been assigned CERCLIS identification number IDD048340921. The facility includes
mining-contaminated areas in the Coeur d'Alene River corridor, adjacent floodplains,
downstream water bodies, tributaries, and fill areas, as well as the 21-square-mile Bunker Hill
"Box" located in the area surrounding the historic smelting operations.
The United States Environmental Protection Agency (EPA) has identified three operable units
(OUs): the populated areas of the Bunker Hill Box (OU 1); the non-populated areas of the Box
(OU 2); and mining-related contamination in the broader Coeur d'Alene Basin (OU 3). This
Record of Decision (ROD) is focused largely on the floodplain and river corridor of OU 3, which
is also referred to as the Coeur d'Alene Basin in this ROD.
2.0 STATEMENT OF BASIS AND PURPOSE
This decision document selects a remedy for OU 3, which was chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as
amended by the Superfund Amendments and Reauthorization Act (SARA), and, to the extent
practicable, the National Oil and Hazardous Substances Contingency Plan (NCP). The decision
is based on the Administrative Record file for this operable unit.
In accordance with the NCP, including 40 CFR 300.430(b)(7), EPA has consulted with states,
tribes, and natural resource trustees during development of the Selected Remedy and sought
concurrence of states and tribes for remedial actions selected within their respective jurisdictions.
Letters reflecting concurrence or support from these governments are attached to this
Declaration.
3.0 ASSESSMENT OF THE SITE
The remedial action selected in this ROD is necessary to protect the public health or welfare or
the environment from actual or threatened releases of hazardous substances into the
environment. Such a release or threat of release may present an imminent and substantial
endangerment to public health, welfare, or the environment.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 2
4.0 DESCRIPTION OF SELECTED REMEDY
Overall Site Cleanup Strategy
The Selected Remedy includes remedial actions for (1) protection of human health in the
communities and residential areas, including identified recreational areas, of the Basin upstream
of Coeur d'Alene Lake (the Upper Basin and Lower Basin), (2) protection of the environment in
the Upper Basin and Lower Basin, and (3) protection of human health and the environment in
areas of the Spokane River.
The Selected Remedy includes a complete remedy for protection of human health in the
communities and residential areas, including identified recreational areas, of the Upper Basin and
Lower Basin. Certain potential exposures outside of the communities and residential areas of the
Upper Basin and Lower Basin are not addressed by this ROD and will continue to present risks
of human exposure to hazardous substances. These potential exposures impacting human health
include:
• Recreational use at areas in the Upper Basin and Lower Basin where cleanup
actions are not implemented pursuant to this ROD
• Subsistence lifestyles, such as those traditional to the Coeur d'Alene and Spokane
Tribes
• Potential future use of groundwater that is presently contaminated with metals
For protection of the environment, the Selected Remedy identifies approximately 30 years of
prioritized actions in areas of the Basin upstream of Coeur d'Alene Lake. During this period,
EPA will evaluate the effectiveness and protectiveness of these remedial actions, as well as the
technical practicability of attaining applicable or relevant and appropriate requirements
(ARARs), in particular, the ambient water quality standards for lead, zinc, and cadmium and
compliance with the Endangered Species Act (ESA) and Migratory Bird Treaty Act (MBTA).
During the five-year review processes and at the end of this approximately 30-year period, EPA
will evaluate and decide whether any additional CERCLA remedial actions are necessary to
attain ARARs or to provide for the protection of human health and the environment, and whether
any ARAR waivers should be applied.
EPA expressly recognizes that after the selected remedial actions are implemented, conditions in
the Upper Basin and Lower Basin may differ substantially from EPA's current forecast of those
future conditions, which is solely based on present knowledge. The tremendous amount of
additional knowledge that will have been gained by the end of this period through long-term
monitoring and five-year review processes may provide bases for future ARAR waivers. In
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 3
addition, this new information and advances in science and technology may allow for additional
actions to achieve ARARs and protect human health and the environment in a more cost-
effective manner.
For the Spokane River, the Selected Remedy includes a complete remedy for protection of
human health upstream of Upriver Dam and a complete remedy for protection of the
environment between Upriver Dam and the Washington/Idaho border. Characterization of the
risks to persons, including Spokane tribal members, and others who may practice a subsistence
lifestyle in the Spokane River area, was not part of the RI/FS investigations. EPA and the
Spokane Tribe are cooperating in planning additional testing and studies that will be
implemented to evaluate the potential exposures to subsistence users. The results of those tests
and studies will determine appropriate future response actions to be taken, if any.
EPA recognizes that the State of Idaho has not concurred in the selection of any remedial action
beyond those selected in this ROD. Furthermore, after implementation of the remedies selected
by this ROD, EPA commits not to take or select any additional remedial actions in the Upper
Basin or Lower Basin without first consulting with the State of Idaho. EPA will continue to
work with the regulatory stakeholder group, which was instrumental in developing the actions
selected in this ROD. Land management agencies may elect to implement cleanup actions on
properties within their management jurisdiction toward achieving the overall goals of the
Selected Remedy.
State legislation under the Basin Environmental Improvement Act (Title 39, Chapter 81)
established the process for the formation of the Basin Environmental Improvement Project
Commission. This commission includes federal, state, tribal, and local governmental
involvement. EPA anticipates working as a member of this commission for implementation of
the ROD and development of priorities and sequencing of cleanup activities.
During development of the Selected Remedy in this ROD, EPA worked with the natural
resources trustees as required by the NCP (40 CFR 300.430(b)(7)) and will continue to work
with the trustees during implementation of the Selected Remedy.
The Bunker Hill Box is a part of the Basin and a major source of metals in surface water. A
ROD was signed for the populated areas of Bunker Hill Box (OU1) in 1991, and a ROD was
signed for the non-populated areas of the Box (OU2) in 1992. Additional remedies for the
Bunker Hill Box have not been selected in the OU2 ROD because the Box is already the subject
of ongoing remedial actions. EPA will integrate actions selected for the Box with those selected
for OU3.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 4
Principal Threat Wastes
Principal threat wastes are those source materials considered to be highly toxic or highly mobile
that generally cannot be reliably contained and/or would present a significant risk to human
health or the environment should exposure occur.1 Principal threat materials in the Coeur
d'Alene Basin may include, for example, metal concentrates spilled during mill operations or in
transport to smelters. A time-critical removal action was conducted in 1999 to address all known
metal surface concentrates associated with rail transport along the Wallace-Mullen Branch of the
Union Pacific Railroad (UPRR). If additional concentrates or other materials that meet the
definition of principal threat waste are encountered during remedy implementation, these
materials would be managed in a manner that is protective of human health and the environment
and consistent with the NCP2 The NCP establishes an expectation that EPA will use treatment
to address the principal threats posed by a site wherever practicable
(NCP§300.430(a)(l)(iii)(A)). Where EPA determines that it is not practicable to use treatment
to address principal threat waste, such waste may be transported off-site, consistent with the Off-
Site Disposal Rule (40 CFR 300.440) or managed safely on-site, consistent with all ARARs
identified in Section 13.2 of this ROD.
Major Components of the Selected Remedy
Figures 1, 2, and 3 show the remedial actions selected for the Upper Basin, Lower Basin, and
Spokane River, respectively. For protection of human health in the community and residential
areas of the Upper Basin and Lower Basin, the major components of the Selected Remedy
include:
Information and intervention programs for residential and recreational users
Partial excavation and replacement of residential soils with lead concentrations
above 1,000 milligrams per kilogram (mg/kg), a barrier such as a vegetative
barrier to control or limit migration of soils with lead concentrations between 700
and 1000 mg/kg, and a combination of removals, barriers, and access restrictions
at commercial and undeveloped properties and recreation areas.
1 Additional information for defining principal threat wastes can be found in U SEP A (199 lb) A Guide to Principal
Threat and Low Level Threat Wastes.
2
Concentrations used to identify principal threat waste within the "Bunker Hill Box" were: 127,000 ppm antimony;
15,000 ppm arsenic; 71,000 ppm cadmium; 84,600 ppm lead; 33,000 ppm mercury (Source: Bunker Hill Non-
Populated Areas ROD, ROD ID: EPA/ROD/R10-92/041, Date: 09/22/1992). Additional factors (e.g., mobility,
repository waste acceptance criteria, etc.) should be evaluated on a site-specific basis prior to disposal of material
associated with implementing the Selected Remedy.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 5
• Vacuum loan program/dust mats and interior source removals and controls to
reduce individual house dust lead concentrations and loadings, as necessary.
(This would be coordinated with paint abatement programs.)
• Multiple alternative drinking water sources (wellhead or point-of-use treatment,
connection to the public drinking water system, or a new well) for residences
using groundwater having metals at concentrations exceeding maximum
contaminant levels (MCLs).
• Property owners in the Basin will be able to request soil sampling necessary for
lead disclosures required for property transactions, and the results will be made
available to them in a timely manner.
For protection of the environment in the Upper Basin and Lower Basin, the major components of
the remedy include:
• Upper Basin. The Selected Remedy includes excavation and disposal,
containment, bioengineering, and surface water treatment actions to reduce
dissolved metals in rivers and streams. The remedy will promote development of
innovative technologies, potentially including surface water treatment in Canyon
Creek and Ninemile Creek. Waste dumps and stream banks that are major
sources of particulate metals will be stabilized to reduce erosion.
• Lower Basin Floodplains. A combination of capping and excavation will be
conducted in high-priority floodplain areas (areas with high use by waterfowl,
high levels of lead in sediments, availability of site access, and relatively low
potential for recontamination during flood events). Soil treatment to reduce lead
bioavailability may be applied in selected areas if effective treatment technologies
are identified.
• Lower Basin Beds and Banks. Excavation of contaminated bank sediment and
bank stabilization will be used for river banks that are highly susceptible to
erosion. A pilot river bed sediment removal program will be conducted in the
Coeur d'Alene River near Dudley. Splay areas where sediments naturally collect
during floods will be engineered to act as traps for collection of contaminated
sediments.
The Selected Remedy does not include remedial actions for Coeur d'Alene Lake. State, tribal,
federal, and local governments are currently in the process of implementing a lake management
plan outside of the Superfund process using separate regulatory authorities.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 6
For shoreline sediment depositional areas along that reach of the Spokane River within the State
of Washington upstream of the Spokane Indian Reservation, the Selected Remedy consists of a
combination of access controls, capping, and removals. The remedy for the contaminated
sediments behind Upriver Dam will be established following further study and engineering
evaluation. Dredging or capping are the options anticipated for sediments behind the dam.
5.0 STATUTORY DETERMINATIONS
Consistent with 40 CFR 300.430(a)(i)(B) and 40 CFR 300.430(f)(l)(ii)(C)(l), the remedial
action selected by this ROD is an interim measure and will neither be inconsistent with nor
preclude implementation of the final remedy that will be identified in subsequent decision
documents.
The measures selected in this remedy will provide an adequate level of protectiveness of human
health and the environment; comply with federal, state, and tribal requirements that are
applicable or relevant and appropriate within the scope of the Selected Remedy; result in a cost-
effective action; utilize permanent solutions and alternative treatment (or resource recovery)
technologies to the maximum extent practicable; and satisfy the statutory preference for
treatment as a principal element of the remedy (i.e., reduce the toxicity, mobility, or volume of
hazardous substances, pollutants, or contaminants as a principal element through treatment).
The remedial actions selected in this ROD are not intended to fully address contamination within
the Basin. Thus, achieving certain water quality standards, such as state and federal water
quality standards and criteria and maximum contaminant levels for drinking water, are outside of
the scope of the remedial action selected in this ROD and are not applicable or relevant and
"3
appropriate at this time. Similarly, special status species protection requirements under the
MBTA and ESA are only applicable or relevant and appropriate as they apply to the remedial
actions included within the scope of the Selected Remedy. The Selected Remedy is designed to
provide prioritized actions towards meeting the statutory requirement of protectiveness of human
health and the environment. Accordingly, the Selected Remedy, by its nature, need not be as
protective as the final remedy is required to be under the statute. Here, the Selected Remedy is
sufficiently protective in the context of its scope, even though it does not, by itself, meet the
statutory protectiveness standard that a final remedy would have to meet.
3 The water quality ARARs apply to point source discharges to surface water created as a result of implementation
of the Selected Remedy. Similarly, maximum contaminant levels are applicable or relevant and appropriate at
residences where an alternate drinking water supply is provided or drinking water is treated.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 1, Declaration
Page 7
In addition, because this remedy will result in hazardous substances, pollutants, or contaminants
remaining on-site above levels that allow for unlimited use and unrestricted exposure, statutory
reviews will be conducted at least every five years after initiation of remedial action to ensure
that the Selected Remedy is, or will be, protective of human health and the environment.
6.0 DATA CERTIFICATION CHECKLIST
The following information is included in the Decision Summary (Part 2) of this ROD.
Additional information can be found in the Administrative Record file for this operable unit.
• Chemicals of concern and their respective concentrations (See Section 7.1.1
Identification of COCs, Tables 7.1-1 through 7.1-5, Tables 7.1-21 and 7.1-22, and
Tables 7.2-2 through 7.2-5).
• Baseline risk represented by the chemicals of concern (See Sections 7.1.1 Risk
Characterization and 7.1.1 Total Subsistence Scenarios and Tables 7.1-12 through
7.1-19).
• Cleanup levels established for chemicals of concern and the basis for these levels
(See Section 8, Section 12.1.1, Section 12.1.3, Section 12.2.3, and Section
12.4.3). For protection of ecological receptors, numerical cleanup criteria have
not yet been established for all chemicals of concern in all media. It is
anticipated, however, that they will be established during implementation of this
ROD and documented in an Explanation of Significant Differences (ESD).
• A discussion of source materials constituting principal threats (See Section 11.0).
• 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 (See Section 6, Section 7.1.1 Exposure Assessment, and
Section 7.1.1 Subsistence Scenarios).
• Potential land and groundwater use that will be available at the site as a result of
the Selected Remedy (See Section 12.1.3, Section 12.2.3, and Section 12.4.3).
• Estimated capital, annual operation and maintenance (O&M), and total present
worth costs, discount rate, and the number of years over which the remedy cost
estimates are projected (See Section 12.1.3, Section 12.2.3, and Section 12.4.3).
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RECORD OF DECISION Part 1, Declaration
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002 Page 8
• Key factor(s) that led to selecting the remedy (i.e., how the Selected Remedy
provides the best balance of tradeoffs with respect to the balancing and modifying
criteria, highlighting criteria key to the decision (See Section 10).
Authorizing Signature
©ate
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Interstate Mine
Cleanup of all
Metals-Adding Sources
Above Success Mine
Rex Mine and Mill
Success Mine and Mill
interstate Mill
South Fork Coeur d'41
Potential Treatment
of Flow from East Fork
terville
Gorpe Gulch
5 Oom Paul
inehurst
Standard- flgfe#
~
Bureau of Impoundment J Da^ro^^Lwi^lj^
amarack
Improve Stream
Riparian Zone
(Pine Creek + East Fork)
Stabilize Sediment Sources in Canyon Creek
*$t Star Mine
Sediment "Hot Spot" Removals
and Bank Stabilization
(South Fork Wallace to Elizabeth Park))
Little Pittsbur
iahl
Highland Surprise Mine and Millsit
Nevada-Stewart Mine
-ifercul*
/K,
Uooer/lower Constitution
LEGEND
Potential Treatment Pond Location
(5 to 10 acres: location to be determined during remedial design)
mi Cleanup actions at dispersed streambank locations
Golconda Mining-related site identified for cleanup.
A Underline denotes site has potential for human health exposures
Note: Of an estimated 4,597 residential yards in the Upper Basin and
Lower Basin, an estimated 907 residences will require partial soil removal
and a soil barrier (lead concentration > 1,000 mg/kg) and an estimated
472 residences will require a barrier (lead concentration = 700 -1000 mg/kg)
Scale In Miles
f,EPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 1
Upper Coeur d'Alene Basin Cleanup Actions
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LEGEND
•jS Riverbank Stabilization
RV Park across from Blackrock Gulch
East of Blackrock Gulch Marsh Beach upstream from Quarry
Blackrock Gulch Beach Quarry Beach
Beachln °'d,Ml£si°n
Mission Flats State Park
. Boat Launch
I Recreation Area Targeted for Cleanup
~ Splay Area Sediment Trap
Lake or Wetland Identified
for Cleanup
Thompson
Lake
uly Marsh
Beach below\
Ward Ridge
seylake
71
Killarney
BoatLaiiiK
South o
Mission Flats
Peter
Slough
7
/ Beach n§af Cqnal
\ Jo KiUarney Laki
West Beach
nearMedimo
•'*V\
BullRun
Park Beach
Old Mission $keel
State Park QUich
Beach
Near East End
of Killarney lake
Hldde
J
RM145 i
Thornpso
Lake
Thompson
Marsh w Bare
i" .iX^Marsh
r m..i
-1 ,
Meqimonr%
\\MfctI
Cave ^1 WA ,
Lalfe 4^% » Medicate Lake
neBeach
r Conduct Removal of up to
2.6 million cubic yards of Riverbed
Sediment after Identifying Priority
Area and Disposal Options
son
TV 4.
I. Villi Camputg Area Medimont
Rainy Hill Fishing Area
Rainy Hill Picnii Area
MedimqntBoat Rqmp
Harrison
l^acon
West of
Blue Lake
RM13S Long Beach/Sprmgston
Springston Beach Site
Across River from Springston
Trestle area next
to Route 97
Harrison
Delta
Note: Of an estimated 4,597 residential yards in the Upper Basin and
Lower Basin, an estimated 907 residences will require partial soil removal
and a soil barrier (lead concentration > 1,000 mg/kg) and an estimated
472 residences will require a barrier (lead concentration = 700-1000 mg/kg)
Scale In Miles
AEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 2
Lower Coeur d'Alene Basin Cleanup Actions
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Murray Rd Bar Complex
(Depositional Area 9)
Replacement of shoreline
deposit and vegetation
Barker Rd, N. Shore
(Common Use Area 204)
Donkey Island Bar
(Depositional Area 24)
Island Complex Floodplain
and Banks
(Depositional Areas 5,6,7, and 8)
Replacement and capping
of impacted shoreline
Replacement and/or capping
of shoreline and bar
Replacement or capping and
bank bioengineering
Harvard Rd Access, N. Bank
(Common Use Area 202)
Upriver Dam Site
Plante Ferry Park Area
(Depositional Area 21)
Replacement of impacted
gravel spawning beds
Dredge or cap impacted
sediments behind dam
Replacement of impacted
shoreline sands
Post Falls
State Line
Spokane
Riv«r ^
Coeur d'Alene Lake
Millwood
"O
Q_
Barker Rd, S. Shore
(Depositional Area 16)
Replacement of impacted
shoreline area
Centennial Bridge/Islands, S. Shore
(Depositional Area 23)
Star Rd Gravel Bar Complex
(Common Use Area 201)
Replacement of impacted
shoreline sands
Flora Rd, S. Shore
(Common Use Area 205)
Replacement of impacted
shoreline area
Replacement of shoreline
deposit and vegetation
Scale In Miles
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 3
Spokane River Cleanup Actions
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
SEPA
REGION 10
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Contents
Page i
TABLE OF CONTENTS
PART 2 DECISION SUMMARY
ABBREVIATIONS AM) ACRONYMS xv
1.0 SITE LOCATION AM) DESCRIPTION 1-1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 2-1
2.1 MINING HISTORY 2-1
2.2 REGULATORY HISTORY 2-2
2.3 PAST REMOVAL ACTIONS IN THE BASIN 2-4
2.3.1 Human Health 2-4
2.3.2 Ecological 2-6
2.4 SITE INVESTIGATION ACTIVITIES 2-6
3.0 COMMIMTY PARTICIPATION 3-1
4.0 SCOPE AND ROLE OF THE SELECTED REMEDY 4-1
4.1 DESCRIPTIONS OF OPERABLE UNITS 4-1
4.1.1 Operable Unit 1 (Populated Areas of the Bunker Hill Box) 4-1
4.1.2 Operable Unit 2 (Non-Populated Areas of the Bunker Hill Box) 4-2
4.1.3 Operable Unit 3 (Coeur d'Alene Basin) 4-4
4.2 SITE CLEANUP STRATEGY 4-6
5.0 SITE CHARACTERISTICS 5-1
5.1 GEOGRAPHY AM) TOPOGRAPHY 5-1
5.1.1 Geographical Organization of the Human Health Alternatives 5-1
5.1.2 Geographical Organization of the Ecological Alternatives for the
Upper Basin and Lower Basin 5-1
5.1.3 Coeur d'Alene Lake 5-2
5.1.4 Spokane River 5-2
5.2 NATURE AND EXTENT OF CONTAMINATION 5-3
5.2.1 Nature and Extent of Contamination Affecting Human Health in
the Community and Residential Areas of the Upper Basin and
Lower Basin 5-3
5.2.2 Nature and Extent of Contamination Affecting Ecological Receptors
in the Upper Basin and Lower Basin 5-5
5.2.3 Nature and Extent of Contamination in Coeur d'Alene Lake 5-8
5.2.4 Nature and Extent of Contamination in the Spokane River Upstream
of the Spokane Indian Reservation 5-9
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Part 2, Decision Summary
Contents
Page ii
TABLE OF CONTENTS (Continued)
6.0 CURRENT AND POTENTIAL FUTURE LAND AND RESOURCE USES 6-1
6.1 CURRENT LAND USE 6-1
6.2 ANTICIPATED FUTURE LAND USES 6-2
6.3 SURFACE WATER AND GROUNDWATER USES 6-2
7.0 SUMMARY OF RISKS 7-1
7.1 SUMMARY OF HUMAN HEALTH RISK ASSESSMENTS 7-1
7.1.1 Baseline Risk Assessment, Harrison to Mullan 7-3
7.1.2 Summary of Screening Level Risk Assessment, Coeur d'Alene
Lake 7-11
7.1.3 Summary of Screening Level Risk Assessment, Spokane River,
Washington State 7-12
7.1.4 Basis for Remedial Action 7-15
7.2 SUMMARY OF ECOLOGICAL RISKS 7-17
7.2.1 Habitat Types 7-19
7.2.2 Ecological Receptors 7-21
7.2.3 Ecological Management Goals and Assessment Endpoints 7-22
7.2.4 Chemicals of Potential Ecological Concern 7-23
7.2.5 Analysis of Ecological Risk 7-25
7.2.6 Characterization of Ecological Risk 7-29
7.2.7 COEC Concentrations Protective of Receptors 7-31
7.2.8 Ecological Goals for Physical and Biological Characteristics 7-33
7.2.9 Conclusions 7-33
8.0 REMEDIAL ACTION OBJECTIVES 8-1
8.1 III MAN III1AL III 8-1
8.2 ECOLOGICAL 8-1
9.0 DESCRIPTIONS OF ALTERNATIVES 9-1
9.1 HUMAN HEALTH ALTERNATIVES FOR THE COMMUNITY AND
RESIDENTIAL AREAS 9-2
9.1.1 Soil Alternatives 9-2
9.1.2 Drinking Water Alternatives 9-4
9.1.3 House Dust Alternatives 9-5
9.1.4 Aquatic Food Sources Alternatives 9-6
9.2 ECOLOGICAL ALTERNATIVES FOR THE UPPER BASIN AND
LOWER BASIN 9-7
9.3 COEUR D'ALENE LAKE 9-10
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RECORD OF DECISION Part 2, Decision Summary
Bunker Hill Mining and Metallurgical Complex OU 3 Contents
September 2002 Page iii
TABLE OF CONTENTS (Continued)
9.4 SPOKANE RIVER 9-11
10.0 COMPARATIVE ANALYSIS OF ALTERNATIVES 10-1
10.1 HUMAN HEALTH ALTERNATIVES 10-1
10.2 ECOLOGICAL PROTECTION IN THE UPPER BASIN AND
LOWER BASIN 10-2
10.3 COEURD'ALENELAKE 10-6
10.4 SPOKANE RIVER 10-6
10.5 CONCLUSIONS FROM COMPARATIVE ANALYSIS 10-6
11.0 PRINCIPAL THREAT WASTE 11-1
12.0 SELECTED REMEDY 12-1
12.1 HUMAN HEALTH PROTECTION IN THE COMMUNITY AND
RESIDENTIAL AREAS OF THE UPPER BASIN AND
THE LOWER BASIN 12-4
12.1.1 Description of the Selected Remedy 12-5
12.1.2 Estimated Remedy Costs 12-12
12.1.3 Expected Outcomes of Selected Remedy 12-14
12.2 ENVIRONMENTAL PROTECTION IN THE UPPER BASIN
AND LOWER BASIN 12-15
12.2.1 Description of the Selected Remedy 12-16
12.2.2 Estimated Cost of the Selected Remedy 12-36
12.2.3 Expected Outcomes of the Selected Remedy 12-38
12.3 COEUR D'ALENE LAKE 12-43
12.4 SPOKANE RIVER 12-44
12.4.1 Description 12-44
12.4.2 Estimated Remedy Costs 12-45
12.4.3 Expected Outcomes of Selected Remedy 12-46
12.5 SITING AND DESIGN OF REPOSITORIES FOR MATERIAL
GENERATED BY CLEANUP ACTIVITY 12-48
12.6 MONITORING AND ADDITIONAL DATA NEEDS 12-52
12.7 STATE AND TRIBE ACCEPTANCE 12-54
12.7.1 State of Idaho Acceptance 12-55
12.7.2 State of Washington Acceptance 12-56
12.7.3 Coeur d'Alene Tribe Acceptance 12-57
12.7.4 Spokane Tribe Acceptance 12-58
12.7.5 Department of Interior 12-59
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September 2002
Part 2, Decision Summary
Contents
Page iv
TABLE OF CONTENTS (Continued)
12.7.6 Department of Agriculture 12-59
12.8 COMMUNITY ACCEPTANCE 12-59
13.0 STATUTORY DETERMINATIONS 13-1
13.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT 13-3
13.1.1 Protection of Human Health in the Community and Residential
Areas of the Upper Basin and the Lower Basin 13-3
13.1.2 Protection of the Environment in the Upper Basin and Lower
Basin 13-4
13.1.3 Spokane River 13-6
13 .2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND
APPROPRIATE REQUIREMENTS 13-7
13.3 COST-EFFECTIVENESS 13-17
13.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE
TREATMENT (OR RESOURCE RECOVERY) TECHNOLOGIES TO
THE MAXIMUM EXTENT PRACTICABLE 13-19
13.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT 13-20
13.6 FIVE-YEAR REVIEW REQUIREMENTS 13-20
14.0 DOCUMENTATION OF SIGNIFICANT CHANGES 14-1
15.0 REFERENCES 15-1
PART 3 RESPONSIVENESS SUMMARY
1.0 OVERVIEW AND BACKGROUND ON COMMUNITY INVOLVEMENT 1-1
2.0 GENERAL COMMUNITY CONCERNS AND THEMES 2-1
2.1 HOW COMMUNITIES AND STAKEHOLDERS HAVE SHAPED THE
CLEANUP PLAN 2-7
2.1.1 Pre-Proposed Plan Responses to Community Input 2-7
2.1.2 Some Ways That the Proposed Plan and ROD are Responsive to
Community Concerns 2-7
2.2 COMMUNITY INVOLVEMENT ACTIVITIES CARRIED OUT BY EPA
IN RESPONSE TO REQUESTS 2-9
3.0 OVERVIEW RESPONSIVENESS SUMMARY 3-1
3.1 COMMUNITY RELATIONS AND COMMUNITY CONCERNS 3-1
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TABLE OF CONTENTS (Continued)
3.1.1 Community Participation in Remedy Selection Process 3-1
3.1.2 Relationship Between Selected Remedy and Basin Environmental
Improvement Project Commission 3-2
3.1.3 Control of Cleanup Work 3-2
3.1.4 Role of Ombudsman 3-3
3.1.5 Job Opportunities 3-3
3.1.6 Need for Certainty and Closure 3-4
3.2 SITE DEFINITION AND FUNDING 3-5
3.2.1 Description of the Superfund Site 3-5
3.2.2 Funding for Cleanup in the Coeur d'Alene Basin 3-5
3.3 REMEDY SELECTION PROCESS 3-6
3.3.1 Description of an "Interim Measure" 3-6
3.3.2 Length of Time, Size, and Complexity of an Interim Measure 3-6
3.3.3 Relationship Between Remedy Selection Requirements and EPA
Guidance Documents 3-7
3.3.4 The Selected Remedy in Relationship to Ecological Alternative 3 3-8
3.3.5 The Selected Remedy in Relationship to a Natural Resource Damages
Restoration Plan 3-8
3.4 BACKGROUND METALS CONCENTRATIONS 3-9
3.4.1 Background Metal Concentrations Absent Mining Effects 3-9
3.4.2 Mining-Related Sources of Metals 3-10
3.5 REMEDIAL INVESTIGATION/FEASIBILITY STUDY 3-10
3.5.1 Scientific Adequacy of RI/FS, Including Risk Assessments, Versus
Need for Independent Study 3-10
3.5.2 Adequacy of Data Collected During RI/FS to Select and Design
Remedy 3-11
3.6 REMEDY EFFECTIVENESS AND IMPLEMENTATION ISSUES 3-12
3.6.1 Remedy Effectiveness Estimates for Surface Water Quality 3-12
3.6.2 Remedy Performance for Ecological Protection 3-12
3.6.3 Estimated Times to Achieve AWQC and the Role of Natural
Recovery 3-13
3.6.4 Idaho TMDL for the Coeur d'Alene Basin 3-15
3.6.5 Relationship of Forest Management Practices to Recontamination
and Water Quality 3-16
3.6.6 Long-Term Protectiveness and Permanence of the Remedy 3-17
3.6.7 Scope of Lower Basin Sediment Removal 3-17
3.6.8 Scope of Remedies for Water Quality and Fish Habitat 3-18
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TABLE OF CONTENTS (Continued)
3.6.9 Siting and Design of Repositories for Material Generated by Cleanup
Activities 3-19
3.6.10 Treatment of Surface Water from Canyon Creek 3-20
3.6.11 Effects of Nonmining Impacts on the Environment 3-22
3.7 SELECTED REMEDY FOR HUMAN HEALTH 3-22
3.7.1 Development of the Human Health Selected Remedy and EPA
National Guidance 3-22
3.7.2 Use of Blood Lead Observations in the HHRA and Development of
the Proposed Plan 3-24
3.7.3 The 2000-2001 Lead Health Intervention Program Blood Lead
Screening Results 3-27
3.7.4 Lead Based Paint and the Relationship to House Dust and Blood
Lead 3-29
3.7.5 Comparison of National Declines in Blood Lead Levels and
Site-Specific Conditions 3-30
3.7.6 Soil Lead Sampling and Particle Size 3-30
3.7.7 Bioavailability, Speciation, and the HHRA 3-31
3.7.8 Subtle Health Effects of Lead Exposure 3-36
3.7.9 Community Support for the Selected Human Health Remedy 3-37
3.8 ECOLOGICAL IS SUES 3-38
3.8.1 Cleanup Criteria 3-38
3.8.2 Waterfowl Issues 3-39
3.8.3 Fish Issues 3-40
3.8.4 Special-Status Species 3-41
3.8.5 Bull Trout 3-42
3.9 ("01T R D'ALENE LAKE 3-42
3.9.1 Relationship Between Selected Remedy and Coeur d'Alene Lake 3-42
3.9.2 Lake Management Plan 3-43
3.9.3 Potential for Release of Metals from Coeur d'Alene Lake Bottom
Sediments 3-43
3.10 BUNKER HILL BOX 3-44
3.10.1 Bunker Hill Box as Source of Metal Contamination 3-44
3.10.2 Relationship Between the Bunker Hill Box and the Selected
Remedy 3-44
3.11 UNION PACIFIC RAILROAD 3-45
3.11.1 UPRR Cleanup in Relationship to the Selected Remedy 3-45
3.12 SPOKANE RIVER 3-46
3.12.1 Anticipated Water Quality Conditions in the Spokane River 3-46
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TABLE OF CONTENTS (Continued)
3.12.2 Sole-Source Spokane Valley-Rathdrum Aquifer 3-46
3.12.3 Cleanup Method for Sediments Behind the Upriver Dam 3-47
3.12.4 Remedies for Contaminated Sediments in Shoreline and Depositional
Areas 3-48
3.12.5 Protectiveness of Shoreline Remedies 3-48
3.12.6 PCBs in Sediments 3-49
3.13 MONITORING 3-50
3.13.1 Monitoring as Part of the Selected Remedy for Ecological
Improvement 3-50
3.13.2 Monitoring of Fish in Coeur d'Alene Lake and the Spokane River 3-50
4.0 RESPONSES TO INDIVIDUAL COMMENTS 4-1
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Contents
Page viii
TABLE OF CONTENTS (Continued)
FIGURES
1 Upper Coeur d' Alene Basin Cleanup Actions
2 Lower Coeur d'Alene Basin Cleanup Actions
3 Spokane River Cleanup Actions
1.0-1 Basin Study Area
5.2-1 Range of Lead Concentrations in Surface Soils and Sediments in the Coeur d'Alene
River Basin
5.2-2 Average Metal Concentrations in Soil, Sediment, and Surface Water
5.2-3 Estimated Average Values of Dissolved Zinc Loads and Concentrations (1991-1999
Data)
5.2-4 Estimated Sources of Dissolved Zinc Load in the Upper Basin (not including the
Bunker Hill Box)
5.2-5 Dissolved Zinc Loads in Canyon Creek at Woodland Park, September 17, 18, and 19,
1999
5.2-6 Discrete and Non-Discrete Sources of Dissolved Zinc Load in South Fork
5.2-7 Estimated Average Values of Total Lead Loads and Concentrations (1991-1999 Data)
5.2-8 Total Cadmium Concentrations in Spokane River Sediments
5.2-9 Lead Concentrations in Spokane River Sediments
5.2-10 Zinc Concentrations in Spokane River Sediments
7.1-1 Average Child's Basin-Wide Lead Exposure
7.1-2 Total RME Noncancer Hazard - Modern and Traditional Subsistence Exposure
Scenarios, All Chemicals (Child Age 0 to 6 Years)
7.1-3 Total RME Noncancer Hazard - Modern and Traditional Subsistence Exposure
Scenarios, All Chemicals (Adult/Child)
7.1-4 Total RME Cancer Risk - Modern and Traditional Subsistence Exposure Scenarios
(Adult/Child)
7.2-1 CSM Unit 1 Boundaries
7.2-2 CSM Unit 2 Boundaries
7.2-3 CSM Unit 3 Boundaries
7.2-4 CSM Unit 4 Boundaries
7.2-5 CSM Unit 5 Boundaries
7.2-6 Ecological Effects Characterization
10.2-1
10.2-2
Estimated Relative Time to Reach AWQC Without Bunker Hill Box Loading
Estimated Time to Reach AWQC Without Bunker Hill Box Loading
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Page ix
TABLE OF CONTENTS (Continued)
10.2-3 Comparison of Expected Value of Zinc AWQC at Pinehurst Without Bunker Hill Box
Loading
10.2-4 Comparison of Expected Value of Zinc AWQC at Harrison Without Bunker Hill Box
Loading
12.1-1 Smelterville Soil and Dust Lead Geometric Means 1990-2001
12.1-2 Lower Basin Recreation Areas
12.1-3 Flow Diagram of Dust Mat Monitoring Protocol
12.2-1 Ninemile Creek Cleanup Actions and Fisheries Status After Implementation of the
Selected Remedy
12.2-2 East Fork Ninemile Creek Cleanup Locations
12.2-3 Probability of Achieving Various AWQC Ratios as a Function of the
Remediation Factor R - Ninemile Station NM305
12.2-4 Comparison of Selected Remedy to Alternative 3, Ninemile Creek
12.2-5 Pine Creek Cleanup Actions and Fisheries Status After Implementation of Selected
Remedy
12.2-6 Comparison of Selected Remedy to Alternative 3, Pine Creek
12.2-7 Treatment Pond Conceptual Design
12.2-8 Lower Canyon Creek Cleanup Actions
12.2-9 Canyon Creek Cleanup Locations
12.2-10 Comparison of Selected Remedy to Alternative 3, Canyon Creek
12.2-11 South Fork Cleanup Locations
12.2-12 Upper South Fork Cleanup Locations
12.2-13 Comparison of Selected Remedy to Alternative 3, South Fork
12.2-14 Lower Basin Cleanup Actions
12.2-15 Comparison of Selected Remedy to Complete Remedy
12.2-16 Upper Basin Fishery Status After Implementation of Selected Remedy
12.2-17 Expected Value of Zinc AWQC Ratio at Pinehurst: Selected Remedy
12.2-18 Expected Value of Zinc AWQC Ratio at Harrison: Selected Remedy
12.4-1 Spokane River Cleanup Actions
TABLES
2.1-1 History of Tailings Disposal Practices in the Coeur d'Alene Basin
2.1-2 Preliminary Estimate of Mill Tailings Produced in the Coeur d'Alene Mining District
2.3-1 Removal Actions for Protection of Human Health By Year (Not Including the Bunker
Hill Box)
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TABLE OF CONTENTS (Continued)
2.3-2 Past Cleanup Actions for Ecological Protection
5.2-1 Summary of Lead Concentrations in the Upper and Lower Basin
5.2-2 Summary of Analytical Results for Metals in Soil
5.2-3 Summary of Analytical Results for Metals in House Dust
5.2-4 Summary of Analytical Results for Metals in Drinking Water
5.2-5 Summary of Estimated Basin Ecological Source Quantities
5.2-6 Estimated Average (Expected) Values of Metals Concentrations in Surface Water in the
Basin, 1991-1999 Data
5.2-7 Estimated Average (Expected) Values of Metals Loads in Surface Water in the Basin,
1991-1999 Data
5.2-8 Summary of Floodplain Areas Affected by Lead, by Wetland Unit
5.2-9 Metals Loads and Retention in Coeur d'Alene Lake
6.3-1 Surface Water Designated Beneficial Uses in Idaho
6.3-2 Coeur d'Alene River Basin Public Drinking Water Systems
6.3-3 Estimated Number of Residences with Private, Unregulated Drinking Water Sources
7.1-1 Summary of Chemicals of Concern and Medium-Specific Exposure Point
Concentrations Current/Future Residential Exposure Scenario
7.1-2 Summary of Chemicals of Concern and Medium-Specific Exposure Point
Concentrations Current/Future Neighborhood Recreational Exposure Scenario
7.1-3 Summary of Chemicals of Concern and Medium-Specific Exposure Point
Concentrations Current/Future Public Recreational Exposure Scenario
7.1-4 Summary of Chemicals of Concern and Medium-Specific Exposure Point
Concentrations Future Residential Use of Tap Water
7.1-5 Summary of Chemicals of Concern and Medium-Specific Exposure Point
Concentrations Future Subsistence Scenario in the Lower Basin
7.1-6 Selection of Exposure Pathways Baseline Risk Assessment, Harrison to Mullan
7.1-7 Residential Exposure Factors for Non-Lead Chemicals
7.1-8 Neighborhood Recreational Exposure Factors for Non-Lead Chemicals
7.1-9 Public Recreational Exposure Factors for Non-Lead Chemicals
7.1-10 Occupational Exposure Factors for Non-Lead Chemicals
7.1-11 Toxicity Data Summary
7. l-12a Predicted Lead Risk for a Typical Child Upper Basin, Side Gulches, and Kingston
7.1-12b Predicted Lead Risk for a Typical Child Lower Basin
7.1-13 RME Risk Characterization Summary - Carcinogens Residential Exposure Scenario -
Child/Adult
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Part 2, Decision Summary
Contents
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TABLE OF CONTENTS (Continued)
7.1-14
7.1-15
7.1-16
7.1-17
7.1-18
7.1-19
7.1-20
7.1-21
7.1-22
7.2-1
7.2-2
7.2-3
7.2-4
7.2-5
7.2-6
7.2-7
7.2-8
7.2-9
7.2-10
7.2-11
7.2-12
8.1-1
8.1-2
8.2-1
RME Risk Characterization Summary - Non-Carcinogens Residential Exposure
Scenario - Child
RME Risk Characterization Summary - Non-Carcinogens Residential Exposure
Scenario - Child/Adult
RME Risk Characterization Summary - Non-Carcinogens Public Recreational
Exposure Scenario - Child
RME Risk Characterization Summary - Carcinogens Subsistence Exposure Scenario -
Child/Adult
RME Risk Characterization Summary - Non-Carcinogens Subsistence Exposure
Scenario - Child
RME Risk Characterization Summary - Non-Carcinogens Subsistence Exposure
Scenario - Child/Adult
Potential Soil Cleanup Levels for Arsenic Using Various Target Risk Goals and
Scenarios
Summary of Chemicals of Concern and Exposure Point Concentrations in Spokane
River CUA Sediment
Summary of Chemicals of Concern and Exposure Point Concentrations in Spokane
River Fish Tissue
Summary of Representative Species Evaluated in Coeur d'Alene Basin
Concentrations of Chemicals of Potential Ecological Concern, Soil-Sediment
Combined
Chemicals of Potential Ecological Concern, Aquatic Sediments
Chemicals of Potential Ecological Concern, Aquatic Surface Water - Dissolved Metals
Chemicals of Potential Ecological Concern, Aquatic Surface Water - Total Metals
COEC Concentrations for Soil (mg/kg) Protective for Terrestrial Biota
COEC Concentrations for Sediment (mg/kg) Protective for Aquatic Birds and
Mammals
COEC Concentrations for Surface Water Protective for Aquatic Organisms
COEC Concentrations for Sediment Protective for Aquatic Organisms
Protective Goals for Physical and Biological Characteristics
Summary of Results from the Coeur d'Alene Basin Ecological Risk Assessment
Summary of Results from the Measures of Ecosystem and Receptor Characteristics
Analysis in the Coeur d'Alene Ecological Risk Assessment
Remedial Action Objectives for Protection of Human Health
ARARs for Drinking Water
Remedial Action Objectives for Protection of Ecological Receptors
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TABLE OF CONTENTS (Continued)
8.2-2
8.2-3
8.2-4
9.2-1
9.2-2
9.2-3
9.2-4
9.2-5
9.2-6
9.2-7
9.2-8
9.2-9
9.2-10
10.0-1
10.1-1
10.1-2
10.1-3
10.1-4
10.2-1
10.3-1
10.4-1
12.0-1
12.1-1
12.1-2
Water Quality Standards and Criteria for Protection of Aquatic Life in Surface Water in
the Upper Basin (CSM Units 1 and 2)
Water Quality Standards and Criteria for Protection of Aquatic Life in the Lower Basin,
Coeur d'Alene Lake, and Spokane River Within Idaho (CSM Units 3, 4 and 5)
Water Quality Standards and Criteria for Protection of Aquatic Life in Surface Water in
the Spokane River Within Washington (CSM Unit 5)
Summary of Ecological Alternatives Developed for the Upper and Lower Basins
Descriptions of Typical Conceptual Designs (TCDs) Used with Alternatives 2, 3, and 4
Summary of Estimated Unit Costs for Removal, Containment, and Treatment TCDs
Alternatives 2, 3, and 4
Summary of Estimated Bioengineering TCD Unit Costs, Alternatives 2, 3, and 4
Summary of Estimated Unit Costs for Lower Basin TCDs, Alternatives 2, 3, and 4
Description of Alternative 5 (State of Idaho) TCDs and Estimated Unit Costs
Alternative 6 (Mining Companies) TCDs and Estimated Unit Costs
Summary of Basin Source Quantities Addressed by Alternative
Contaminated Habitat Area Remediated by Alternative
Estimated Effectiveness of the Ecological Alternatives for the Upper Basin and Lower
Basin for Reducing Dissolved Metals Loads in the Coeur d'Alene River
Evaluation Criteria for Superfund Remedial Alternatives
Comparison of Soil Alternatives for Protection of Human Health in Residential and
Community Areas
Comparison of House Dust Alternatives for Protection of Human Health in Residential
and Community Areas
Comparison of Drinking Water Alternatives for Protection of Human Health in
Residential and Community Areas
Comparison of Aquatic Food Sources Alternatives for Protection of Human Health
Comparison of Ecological Alternatives for the Upper Basin and Lower Basin
Comparison of Alternatives for Coeur d'Alene Lake
Comparison of Alternatives for the Spokane River
Summary of Feasibility Study Alternatives Used and Estimated Costs of the Selected
Remedy
Estimated Number of Residential Yards Exceeding Lead Cleanup Levels in the Upper
Basin and Lower Basin
Summary of the Selected Remedy for Human Health Protection in Community and
Residential Areas
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Contents
Page xiii
TABLE OF CONTENTS (Continued)
12.1-3 1996 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
12.1-4 1997 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
12.1-5 1998 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
12.1-6 1999 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
12.1-7 2000 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
12.1-8 2001 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
12.1-9 Blood Lead Screening Results for the Basin by Year (Ages 0-6 Only)
12.1-10 Estimated Number of Residences With Drinking Water MCL Exceedances in the Upper
Basin and Lower Basin
12.1-11 Estimated Costs for Residential Soil
12.1-12 Estimated Costs for Street Rights-of-Way, Commercial Properties, and Common Areas
12.1-13 Summary of Estimated Costs for Recreation Areas
12.1-14 Summary of Estimated Costs for House Dust
12.1-15 Summary of Estimated Costs for Drinking Water
12.1-16 Summary of Estimated Costs for Aquatic Food Sources
12.2-1 Summary of the Selected Remedy for Ecological Protection in the Upper Basin and
Lower Basin
12.2-2 Summary of Anticipated Fisheries Status After Implementation of the Selected Remedy
12.2-3 Summary of Estimated Costs for Ninemile Creek
12.2-4 Summary of Estimated Costs for Pine Creek
12.2-5 Summary of Estimated Costs for Canyon Creek
12.2-6 Summary of Estimated Costs for the South Fork
12.2-7 Summary of Estimated Costs for Lead in Floodplains
12.2-8 Summary of Estimated Costs for Particulate Lead in Surface Water
12.4-1 Summary of the Selected Remedy for the Spokane River
12.4-2 Summary of Estimated Cost Range for the Spokane River
PART 3 TABLES
3.7-1 Summary Statistics for Environmental Variables for Two Data Sets
3.7-2a IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic
Area, Ages 9-84 Months: Default and 40:30:30 - with repeat observations
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TABLE OF CONTENTS (Continued)
3.7-2b IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic
Area, Ages 9-84 Months: Default and 40:30:30 - without repeat observations
3.7-3a IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-60 Months: Default and 40:30:30 - with repeat observations
3,7-3b IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-60 Months: Default and 40:30:30 - without repeat observations
3,7-4a IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-24 Months: Default and 40:30:30 - with repeat observations
3,7-4b IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-24 Months: Default and 40:30:30 - without repeat observations
3,7-5a General Linear Model and Regression Coefficients for Blood Lead and
Environmental Sources - with repeat observations
3,7-5b General Linear Model and Regression Coefficients for Blood Lead and
Environmental Sources - without repeat observations
3.7-6 Blood Lead Declines in National Surveys, Smelterville, and Kellogg
4-1 Individual Comments and Responses Organized by Name of Person Providing
Comment
4-2 Referenced Responses Organized in Numerical Order
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Part 2, Decision Summary
List of Abbreviations and Acronyms
Page xv
LIST OF ABBREVIATIONS AND ACRONYMS
ALAD
delta-aminolevulinic acid dehydratase
AMD
acid mine drainage
AOC
administrative order on consent or area of contamination
ARARs
applicable or relevant and appropriate requirements
ARPA
Archeological Resources Protection Act
AT SDR
Agency for Toxic Substances and Disease Registry
AWQC
ambient water quality criteria (national recommended water quality criteria)
BLM
Bureau of Land Management
CAC
Citizen's Advisory Committee
CDA
Coeur d'Alene
CDC
Centers for Disease Control
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act
CERCLIS
Comprehensive Environmental Response, Compensation, and Liability
Information System
CFR
Code of Federal Regulations
cfs
cubic feet per second
CIA
Central Impoundment Area
CIP
community involvement plan
COC
chemical of concern
COEC
chemical of environmental concern
COPC
chemical of potential concern
COPEC
chemical of potential environmental concern
CSM
conceptual site model
CTP
Central Treatment Plant
CUA
common use area
CV
coefficient of variation
cy
cubic yard
DA
depositional area
DOI
Department of Interior
DOJ
Department of Justice
ED20
effective dose (corresponding to a 20% increase in an adverse effect, relative to
the control response)
EE/CA
engineering evaluation/cost analysis
EPA
Environmental Protection Agency
EPC
exposure point concentration
ESA
Endangered Species Act
ESD
explanation of significant differences
FS
feasibility study
FSPA
field sampling plan amendment
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Part 2, Decision Summary
List of Abbreviations and Acronyms
Page xvi
HEPA
HHRA
HI
HQ
ICP
IDAPA
IDEQ
IDHW
IEUBK
LDR
LHIP
LOAEL
LOEC
MBTA
MCL
MCLG
Hg/L
(J-g/dL
[j,m
mg/kg
MTCA
NAAQS
NAGPRA
NCP
NHANES
NHPA
NOAEL
NOEC
NPDES
NRD
O&M
OSWER
OU
PHD
PRG
PRP
RAO
RBC
RCRA
RfD
LIST OF ABBREVIATIONS AND ACRONYMS (Continued)
high efficiency particulate arresting
human health risk assessment
hazard index
hazard quotient
Institutional Controls Program
Idaho Administrative Procedures Act
Idaho Department of Environmental Quality
Idaho Department of Health and Welfare
integrated exposure uptake biokinetic model
land disposal restriction
Lead Health Intervention Program
lowest observed adverse effects level
lowest observed effects concentration
Migratory Bird Treaty Act
maximum contaminant level
maximum contaminant level goal
micrograms per liter
micrograms per deciliter
micrometer
milligrams per kilogram
Model Toxics Control Act
National Ambient Air Quality Standards
Native American Graves Protection and Repatriation Act
National Oil and Hazardous Substances Contingency Plan
National Health and Nutrition Examination Survey
National Historic Preservation Act
no observed adverse effects level
no observed effects concentration
National Pollutant Discharge Elimination System
natural resources damage
operation and maintenance
Office of Solid Waste and Emergency Response
operable unit
Panhandle Health District
preliminary remediation goal
potentially responsible party
remedial action objective
risk-based criteria
Resource Conservation and Recovery Act
reference dose
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List of Abbreviations and Acronyms
Page xvii
RI
RME
ROD
ROW
SAB
SARA
scs
SVNRT
TBC
TCD
TMDL
TRV
TT
UCL95
UPRR
USD A
USFS
USFWS
USGS
WAC
LIST OF ABBREVIATIONS AND ACRONYMS (Continued)
remedial investigation
reasonable maximum exposure
Record of Decision
right-of-way
Service Advisory Board
Superfund Amendments and Reauthorization Act
Supplemental Control System
Silver Valley Natural Resources Trustees
to be considered
typical conceptual design
total maximum daily load
toxicity reference value
treatment technique
95 percent upper confidence level
Union Pacific Railroad
United States Department of Agriculture
United States Forest Service
United States Fish and Wildlife Service
United States Geological Survey
Washington Administrative Code
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PART 2
DECISION SUMMARY
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RECORD OF DECISION
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September 2002
Part 2, Decision Summary
Section 1.0
Page 1-1
1.0 SITE LOCATION AND DESCRIPTION
The Bunker Hill Mining and Metallurgical Complex Superfund Facility, located in the Coeur
d'Alene Basin, was listed on the National Priorities List (NPL) in 1983. The NPL facility has
been assigned CERCLIS identification number IDD048340921. The facility includes mining-
contaminated areas in the Coeur d'Alene River corridor, adjacent floodplains, downstream
waterbodies, tributaries, and fill areas, as well as the 21-square mile Bunker Hill "Box" located
in the area surrounding the historic smelting operations.
The United States Environmental Protection Agency (EPA) has identified three operable units
(OUs): the populated areas of the Bunker Hill Box (OU 1); the non-populated areas of the Box
(OU 2); and mining-related contamination in the broader Coeur d'Alene Basin (OU 3). This ROD
is focused largely on the floodplain and river corridor of OU 3, which is also referred to as the
Coeur d'Alene Basin (the Basin) in this ROD.
EPA is the lead agency for this decision document. The support agencies for those remedial
actions selected within the boundaries of the respective state or tribal jurisdiction are the Idaho
Department of Environmental Quality (IDEQ), the State of Washington Department of Ecology
and the Coeur d'Alene Tribe. EPA will seek concurrence by the Spokane Tribe of Indians for
future remedial actions selected within the boundary of the Spokane Indian Reservation, if any.
The Selected Remedy in this decision document was chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as
amended, and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).
This decision is based on the administrative record for the Operable Unit 3.
Within the Basin, historic mining practices, beginning in the late 1880s, have resulted in
widespread contamination. This contamination threatens both human health and the
environment. The site contaminants are primarily metals, and the metals considered of principal
concern include lead and arsenic for protection of human health, and lead, cadmium, and zinc for
protection of ecological receptors.
Figure 1.0-1 presents a map of the study area. The study area includes four geographic areas.
• The Upper Basin, the location of former and current mining, milling, and
processing activities. (The mining-related waste materials in the Basin were and
are released during these activities. The Upper Basin includes the South Fork and
the Canyon Creek, Ninemile Creek, Big Creek, Moon Creek, and Pine Creek
watersheds.)
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 1.0
Page 1-2
• The Lower Basin, which includes the Coeur d'Alene River, adjacent lateral lakes,
floodplain, and associated wetlands
• Coeur d'Alene Lake
• Depositional areas of the Spokane River, which flows from Coeur d'Alene Lake
-------
Franklin D. Roosevelt Lake
(Columbia River)
INfM
Bonner County
Kootenai County
Tribe Reservation
Wellpinit
Long Lake
Post Falls
Uoriver
Coeur dAlene
Spokane-1
Bunker
UPPER
BASIN
JkW LOWER
BASIN
Kingst
^lene Rivf
08bu*rS=\//$>uih Fork
Wallace MuUan
Harrison
v •«. Kootenai^County'
I I. M rUBB ¦ I HI
r Benewah (County
CpeurdAlene
Tribe Reservation
Seattle
Spokane
Washington
Portland
Montana
Bo se
Approximate Scale In Miles NORTH
SEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 1.0-1
Basin Study Area
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Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 MINING HISTORY
Mining within the Coeur d'Alene Basin began more than 100 years ago. The Basin has been one
of the leading silver, lead, and zinc-producing areas in the world, with production of
approximately 1.2 billion ounces of silver, 8 million tons of lead, and 3.2 million tons of zinc
(Long 1998). The region surrounding the South Fork has produced over 97 percent of the ore
mined in the Basin (SAIC 1993). The Bureau of Land Management (BLM) has identified nearly
900 mining or milling-related features in the region surrounding the South Fork (BLM 1999).
Table 2.1-1 provides an overview of the history of milling and tailings disposal practices in the
Basin.
Mining-related activities generated tailings (the part of the ore from which metals cannot be
recovered economically, usually 80 to 90 percent of the ore), waste rock (non-ore rock excavated
from a mine), concentrates, and smelter emissions. In addition, the water that drains from many
abandoned adits contains elevated levels of metals. These are the sources of metals
contamination in the Basin.
Until 1968, most tailings were discharged directly into the South Fork or its tributaries. Since
1968, tailings produced have generally been impounded or placed back in the mines. Current
mining practices contribute relatively little contamination to the river system compared to the
existing contamination resulting from pre-1968 practices. An estimated 62 million tons of
tailings were discharged to streams prior to 1968. These tailings contained an estimated 880,000
tons of lead and more than 720,000 tons of zinc. Table 2.1-2 summarizes the quantities of
tailings and metals disposed of by various methods.4
Most of the tailings were transported downstream, particularly during high flow events, and
deposited as lenses of tailings or as tailings/sediment mixtures in the bed, banks, floodplains, and
lateral lakes of the Upper Basin and Lower Basin and in Coeur d'Alene Lake. Some fine-
grained material washed through the lake and was deposited as sediment within the Spokane
River flood channel. The estimated total mass and extent of impacted materials (primarily
sediments) exceeds 100 million tons dispersed over thousands of acres.
4 Minerals are the source of metals (e.g., lead, cadmium, and zinc) released to the environment from historic mining
activities. However, although the "mineral form" of these metals may influence their mobility and toxicity (i.e.,
bioavailability), the metals are hazardous substances under CERCLA. In the context of the CERCLA statute and the
NCP regulations that implement CERCLA, "metal" as a hazardous substance generally means "total metals," and
does not depend on the mineral it may be associated with.
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Bunker Hill Mining and Metallurgical Complex OU 3
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Part 2, Decision Summary
Section 2.0
Page 2-2
In addition to transport in water, mining waste accumulated along the railroad lines as a result of
spillage of ore and concentrates from railroad cars during transport, was used as fill material for
construction of roads, railroads, and structures, and was transported as airborne dust.
2.2 REGULATORY HISTORY
The following is a history of CERCLA-related regulatory actions within the Basin.
• 1983, Bunker Hill Mining and Metallurgical Complex placed on the National
Priorities List (NPL).
• 1986, Idaho settles natural resource damages (NRD) claim against the mining
companies for $4.5 million.
• 1991, Bunker Hill Mining Company files for Chapter 11 bankruptcy. EPA
subsequently resolved its claims against Bunker Hill Mining Company as part of
the bankruptcy proceedings.
• 1991, Coeur d'Alene Tribe files a NRD lawsuit against Gulf Resources &
Chemical Corporation, Pintlar Corporation, ASARCO, Inc. (ASARCO),
Government Gulch Mining Company, Ltd., Federal Mining and Smelting
Company, Hecla Mining Company (Hecla), Sunshine Mining Company
(Sunshine Mining), Callahan Mining Corporation (Callahan), and Union Pacific
Railroad Company (UPRR). That year, the Tribe settled with Callahan (prior to its
merger with Coeur d'Alene Mines Corporation).
• July 1992, Bunker Limited Partnership (BLP) files for Chapter 11 bankruptcy.
EPA subsequently resolved its claims against BLP as part of the bankruptcy
proceedings.
• 1994, Gulf Resources files for Chapter 11 bankruptcy. EPA subsequently
resolved its claims against Gulf Resources as part of the bankruptcy proceedings.
• May 1994, EPA and Idaho enter into a consent decree with the Upstream Mining
Group (ASARCO, Coeur d'Alene Mines Corporation, Callahan, Hecla, Sunshine
Precious Metals, and Sunshine Mining) for remedial work inside the Bunker Hill
Box.
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Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-3
• 1995, potential responsible parties (PRPs), including UPRR and Stauffer
Chemical, sign consent decree to implement Non-Populated Areas remedial
actions, including:
Remediation of UPRR right-of-way through the Box (UPRR)
Closure of A-4 gypsum pond (Stauffer Chemical)
• March 1996, the Department of Justice (DO J), on behalf of EPA, U.S.
Department of Agriculture, and U.S. Department of the Interior, files a complaint
in U.S. District Court for the District of Idaho against the ASARCO, Hecla,
Sunshine Mining Company, and Coeur d'Alene Mines Corporation, seeking:
- Declaration of mining company liability for response costs outside the Bunker
Hill Box
- Payment of natural resource damages inside and outside the Bunker Hill Box
• The case filed by DOJ is consolidated with a pending claim by Coeur d'Alene
Tribe.
• September 1997, EPA and ASARCO sign an Administrative Order on Consent
(AOC) for an engineering evaluation/cost analysis (EE/CA) to examine use of
wetland treatment systems to address mine adit discharge in Canyon Creek.
• 1998, EPA initiates a remedial investigation and feasibility study (RI/FS) for the
Coeur d'Alene Basin.
• August 1999, EPA issues a Unilateral Administrative Order for a removal action
to address spillage of metal concentrates along the UPRR right-of-way.
• March 2000, EPA, the U.S. Forest Service (USFS), and ASARCO sign an AOC
for an EE/CA at the Jack Waite Mine Site in the watershed of the North Fork of
Coeur d'Alene River.
• June 2000, 9th Circuit Court of Appeals vacates the decision by U.S. District
Court that limited the scope of the NPL facility to the 21-square-mile Bunker Hill
Box. The mining companies are given the opportunity, but fail to appeal. The
decision confirms that the NPL facility includes all areas of the Coeur d'Alene
Basin where mining contamination has come to be located.
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Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-4
• August 2000, U.S. District Court approves the consent decree among Union
Pacific, State of Idaho, Coeur d'Alene Tribe, and the United States for the railroad
right-of-way. A $30 million settlement will provide for cleanup of mining
contamination within the right-of-way and conversion of right-of-way for use as a
recreational trail, consistent with the federal Rails-To-Trails Act. The trail will be
operated by the State and Tribe, and the cleanup will be maintained in perpetuity
by funding from Union Pacific.
• January 2001, U.S. District Court approves the consent decree between Sunshine
Mining Company, the United States, and the Coeur d'Alene Tribe.
• May 2001, U.S. District Court approves the Consent Decree between the United
States and defendants Coeur and Callahan. Settlement requires payment of $3.8
million plus conduct of removal action on Coeur's property and transfer of the 74-
acre parcel.
• Between January and July 2001, the first phase of the trial regarding liability was
conducted in district court in Boise, Idaho, with ASARCO and Hecla as principal
defendants. The U.S. District Court has not yet ruled on the liability of ASARCO
or Hecla.
2.3 PAST REMOVAL ACTIONS IN Till BASIN
Some of the most highly impacted source materials have been contained under CERCLA
removal actions, mostly in the Upper Basin, to reduce human health and environmental risks.
These removal actions are summarized in this section. In addition, extensive remedial actions
have been conducted within the Bunker Hill Box in accordance with the OU 1 and OU 2 RODs.
These response actions are described in Section 9.0.
2.3.1 Human Health
Ongoing actions to protect human health have included intervention programs and removal
actions. The Lead Health Intervention Program, administered by the Panhandle Health District
(PHD), provides personal health and hygiene information to help reduce exposure to metals.
Services include educational programs, health monitoring programs, yard and home sampling,
and nursing follow-up services.
The strategy for Basin removal actions is consistent with the 1998 clarification (USEPA 1998a)
of the 1994 Lead Directive (USEPA 1994a). The response strategy also is consistent with
actions taken in the Bunker Hill Box from 1989 through 2001, where intervention and soil
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-5
cleanup actions have contributed to a 69 percent decline in average blood lead levels among
Kellogg children (from 10.8 to 3.4 micrograms per deciliter [j_ig/dL]). Actions are first targeted
at homes where pregnant women reside and homes where families have children 6 years of age
and under. Schools, day care facilities, and other common areas typically used by children also
are in the first tier of response. Basin removal actions have included both soil removals and
treatment of drinking water or municipal hook-up for homes on contaminated private wells.
Basin soil removal actions have been conducted at 91 residential yards, 7 schools and day cares
and 6 recreational areas and common-use areas from 1997 through 2001. Drinking water
treatment, municipal hook-up, or bottled water have been provided to approximately 28
residences. The residential yard removals represent approximately 10 percent of the estimated
total number of yards with lead concentrations greater than 1,000 milligrams per kilogram
(mg/kg) in the Basin. In addition, the high-risk yard removals have reduced exposures to a
significant percentage of children in the Basin since most of the remediated yards have children
in residence. A summary of time-critical removal actions conducted to protect human health is
presented in Table 2.3-1.
Union Pacific Railroad is conducting a cleanup within the 72-mile railroad right-of-way for the
main line track and related sidings of Union Pacific Railroad's Wallace-Mullan Branch. This
line extends from Mullan to Plummer Junction, Idaho. In 1999, UPRR conducted a time-critical
removal action to prevent exposures to metal concentrates located within the railroad right-of-
way. Current cleanup activities are mandated by a consent decree between the United States, the
Coeur d'Alene Tribe, the State of Idaho, and UPRR. This 2000 consent decree followed an
extensive engineering evaluation/cost analysis (EE/CA) which was performed under CERCLA
removal authority. Considerable soil sampling characterization was performed as part of the
EE/CA as well as during implementation of the consent decree. As delineated in the consent
decree's statement of work (SOW) and its attachments, the cleanup uses combinations of
removals and disposal/consolidation, protective barriers, and institutional controls. The cleanup
includes removal of shallow contaminated soil and placement of an asphalt cap over part of the
right-of-way for conversion to a recreational trail as part of the federal Rails-To-Trails Act. The
trail will be operated by the State of Idaho and Coeur d'Alene Tribe, and the cleanup maintained
in perpetuity by UPRR funding.
The UPRR cleanup is not designed, in and of itself, to clean up all portions of the right-of-way.
EPA recognizes that additional actions may be warranted in portions of the right-of-way,
particularly in floodplain areas that are susceptible to recontamination. As cleanup is
implemented under the UPRR cleanup and the Selected Remedy, results may indicate additional
actions are warranted within portions of the right-of-way. These actions will be conducted using
appropriate regulatory authorities.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-6
2.3.2 Ecological
Many cleanup actions have been conducted at source areas and at depositional areas throughout
the Basin. These actions have occurred from 1989 to the present and have been conducted by the
mining companies, UPRR, various state and federal agencies, and the Coeur d'Alene Tribe. The
mining companies and government agencies have worked in concert on many of these actions.
For example, the Silver Valley Natural Resource Trustees (SVNRT), a cooperative effort of the
IDEQ and the mining companies, has conducted significant cleanup activities. However, given
the extensive contamination present, the bulk of the mining-related wastes that are deposited
throughout the river and floodplain still remain.
Most of the cleanup actions have focused on source areas within Canyon Creek, Ninemile Creek,
Moon Creek, Pine Creek, and the South Fork Coeur d'Alene River in the Osburn area. Other
minor actions have been conducted in the Upper South Fork watershed and in the lower Coeur
d'Alene River and lateral lakes areas. A summary of past cleanup actions for ecological
protection is presented in Table 2.3-2.
2.4 SITE INVESTIGATION ACTIVITIES
The first comprehensive study of human health effects outside of the Box was conducted in 1996
by the Idaho Department of Health and Welfare (IDHW) and the Agency for Toxic Substances
and Disease Registry (IDHW 2000). The study indicated excessive levels of lead absorption by
children. Elevated blood lead levels were associated with lead loading in dust mats and bare soil
in outdoor play areas (IDHW 2000). In 1997, EPA collected samples of soil, sediment,
groundwater, surface water, and other environmental media (e.g., indoor dust, lead-based paint,
garden produce) in the Basin. In 1998, EPA began the RI/FS process. To guide field sampling
efforts, a generic field sampling plan and quality assurance project plan were prepared that
included descriptions of methods that would be used to collect and analyze samples, conduct
field measurements, and manage data (USEPA 1997a). Numerous project-specific sampling
plans were developed as field sampling plan addenda (FSPAs) to the base plan (USEPA 1999b,
USEPA 1999c, USEPA 1999d). Each FSPA was developed to address specific data gaps
identified after reviewing available historical data and results of previous field sampling and
analysis efforts. FSPAs were developed in general accordance with EPA's data quality
objectives process (USEPA 1994b). Detailed descriptions of the investigations are presented in
Section 4.2 of Part 1 of the RI (USEPA 2001b).
More than 10,000 samples were collected to support the remedial investigation. These samples,
combined with the 7,000 additional samples collected independently by IDEQ, United States
Geological Survey (USGS), United States Fish and Wildlife Service (USFWS), the mining
companies, EPA under other regulatory programs (e.g., National Pollution Discharge
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
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Part 2, Decision Summary
Section 2.0
Page 2-7
Elimination System [NPDES]), and others provide a solid basis to support informed risk
management decisions for Coeur d'Alene Basin mining waste contamination. However, the
large geographic area of the Basin made it impractical to collect all the data needed to fully
characterize each source area or watershed. Further data collection will be necessary to support
remedial design for areas identified as requiring cleanup. This may include areas where previous
cleanup actions have taken place, such as floodplain areas of the UPRR right-of-way (ROW) or
other areas where previous removal actions have addressed some, but not all, contamination
present.
A human health risk assessment (HHRA) and an ecological risk assessment (EcoRA) were
conducted for the Basin. The HHRA and the EcoRA are described in Sections 7.1 and 7.2,
respectively. EPA funded the State of Idaho to be the technical lead for preparation of the
HHRA, consistent with EPA lead guidance documents, through a Memorandum of Agreement
between EPA and IDEQ (USEPA and IDEQ 1999). The lead risks portion of the HHRA was
prepared by IDEQ, with oversight provided by EPA staff and a review board appointed by the
governor of Idaho. The non-lead risks portion of the HHRA was prepared by EPA.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
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Part 2, Decision Summary
Section 2.0
Page 2-8
Table 2.1-1
History of Tailings Disposal Practices in the Coeur d'Alene Basin
Diilc
Mik'slnnc
1886
Processing of ore initiated using jigging.
1891
Six mills operating, with a total capacity of 2,000 tons per day
1901-1904
Construction of plank dams on Canyon Creek near Woodland Park and on the South Fork near
Osburn and Pinehurst to control tailings movement. Large volumes of tailings accumulate
behind the dams.
1905
Jig tailings from the Morning mill contained about 8% lead and 7% zinc.
1900-1915
Recovery of zinc initiated during this period. Previously, zinc was not recovered, and mills
primarily processed low-zinc ores.
1906
Total milling capacity in the basin was 7,000 tons per day
1910
Flotation introduced in the basin at the Morning mill. Increased metals recoveries were
achieved using flotation. Flotation tailings were finer grained than jig tailings and were
transported greater distances by streams.
1917
Plank dams at Woodland Park and Osburn breached by flood waters.
1918
Flotation had been adopted at most mills by this time.
mid-1920s
Tailings observed in Spokane River.
1925
Flotation tailings from the Morning mill contained <1% each of lead and zinc.
1926-1928
Bunker Hill mills began placing tailings at Page Pond and the present-day location of the
Central Impoundment Area.
1932
Dredging operations initiated in Lower Coeur d'Alene below Cataldo. Dredging continued
until 1967. Dredge spoils were placed at Mission Flats.
1933
Plank dam near Pinehurst breached by flood waters.
1940-1942
Addition of 12 new mills with a combined capacity of 2,000 tons per day. Total milling
capacity in the basin was 12,000 tons per day.
1940s
A portion of the tailings that had accumulated behind the Osburn and Woodland Park plank
dams were reprocessed for metals recovery.
Late 1950s
Reuse of tailings as stope fill initiated.
1960s
Start of 1-90 construction. Tailings from Mission Flats and Bunker Hill tailings pond used in
embankment construction.
1968 to present
Tailings produced during this time have generally been impounded or used as stope fill.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-9
Table 2.1-2
Preliminary Estimate of Mill Tailings Produced in the Coeur d'Alene Mining District
Moliils Coiiliiinod in Tiiilin^s
Disposiil
Tiiilin^s
(Ions)
Method'
Dill os
(Ions)
Sil\er
l.i'iiri
Zinc
To creeks
1884-1967
61,900,000
2,400
880,000b
>720,000
To dumps
1901-1942
14,600,000
400
220,000
>320,000
Mine backfill
1949-1997
18,000,000
200
39,000
22,000
To impoundments
1928-1997
26,200,000
300
109,000
180,000
Total
1884-1997
120,700,000
3,300
1,248,000
>1,242,000
aLong (1998) defines dumps as unsecured stockpiles of tailings. Impoundments are secured by dams or other
structures. Many impoundments were built over and from older tailings dumps.
bBookstrom, et al. (2001) report that an additional 57,000 ±5,500 tons of lead were contained in slimes lost
indirectly to the South Fork.
Source: Long (1998)
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 2.0
Page 2-10
Table 2.3-1
Removal Actions for Protection of Human Health By Year
(Not Including the Bunker Hill Box)
1 (Mill
Ihrouiih
Aclions
l')«>7
rm
I'm
2000
2001
2001
Residential yards
7
11
23
25a
25
91
Schools/day cares
lb
-
3
2
1
7
Recreational and
_d
-
4
1
1
6
common-use areas
Educational signage
-
-
9
-
-
9
Bottled water
-
-
10
1
-
11
Start of end-of-tap
-
-
4
1
-
5
water treatment0
Municipal water
hookup
-
-
6
6
-
12
Cubic yards of
1,935
1,500
20,000
12,000
6,400
41,835
contaminated soil
removed
Cost
$149,000
$249,000
$2,100,000
$2,300,000
$2,300,000
$6,998,000
a 2000 yard tally includes 2 homes with exterior lead-based paint that were pressure-washed prior to removal of
contaminated soil.
b Silver Hills Middle School was started in 1997 and completed in 1998 due to extremely large size and coordination
with school schedules.
0 Once started, end-of-tap water treatment has been provided each year and will continue until a more permanent
solution (e.g., municipal water hookup) is made available.
d In 1997, BLM addressed health concerns at the Killarney Lake Boat Ramp (cleanup was not conducted under
removal action authorities).
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Bunker Hill Mining and Metallurgical Complex OU 3
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Part 2, Decision Summary
Section 2.0
Page 2-11
Table 2.3-2
Past Cleanup Actions for Ecological Protection
Site Niimo
Responsible
Aticncv/r.nlilv
Diilcs of
Action
Description ol' Action
I |)|RT South l-ork
Morning Mine No. 6
Hecla
1989 and
2000
Adit drainage directed to subsurface flow, rock-bed filter treatment system.
Slaughterhouse Gulch was lined to reduce infiltration through the waste rock pile.
(illlVOII (reek
Standard Mammoth Tacilit}
ASARCO
1W~-199X
Rcniov al of tailings \\ nh disposal al Woodland Park Repository. Rcgradcd, stabilized,
capped and revegetated waste rock pile. Removed railroad grade and crossing
Canyon Creek from Tamarack to
below Gem
SVNRT
1997-1998
Time-critical removal of-127,000 cy of tailings and contaminated sediment with
disposal at the Woodland Park Repository. Soils at removal areas were amended with
organic materials, then revegetated. The stream channel of Canyon Creek was
stabilized withbioengineering techniques.
Gem Millsite
SVNRT
2000-
present
Pilot system (10 gallons per minute (gpm)) for treatment of drainage from the Gem
Portal.
Lower Canyon Creek Floodplain
SVNRT
1997-1998
Time-critical removal of 472,000 cy of tailings and contaminated materials with
disposal at the Woodland Park Repository. Soils at removal areas were amended with
organic materials, then revegetated. The stream channel of Canyon Creek was
stabilized withbioengineering techniques.
Woodland Park Repository
SVNRT
1997-1998
Construction of an unlined repository for disposal/consolidation of removals along
Canyon Creek. Repository contains approximately 600,000 cy of contaminated
materials. Repository capped with native soils and revegetated.
Nine-mile (rock
liileiMale Tailings Roniov ul
llccla
1992-1993
Rcniov al of tailings adjacent to Last l-'ork Niiicnulc Crock (LI'WIC) with
consolidation to a nearby uphill area. Installation of straw bales along perimeter of
tailings for erosion control.
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Section 2.0
Page 2-12
Table 2.3-2 (Continued)
Past Cleanup Actions for Ecological Protection
Site Niimo
Responsible
.\iieiie\/r.n(i(\
Diiles of
Action
Description of Action
Interstate Millsite
SVNRT, IDEQ,
Hecla
1998
Non time-critical removal of -60,000 cy of tailings, mill debris, and contaminated
sediments from the mill site and from EFNMC for 1000 feet downstream. Disposal at
an on-site repository. EFNMC stabilized with bioengineering structures in removal
areas.
Success Mine/Mill Tailings and Waste
Rock
EPA, IDEQ
1993
Time-critical removal action included relocation and riprap armoring for -1,600 feet
of EFNMC channel; relocation of streamside tailings; placement of in-stream
structures for energy dissipation; capping of tailings pile with 1-foot thick overburden
rock; installation of upgradient groundwater and surface water diversions.
Success Mine Site Passive Treatment
IDEQ
2000-
present
Contaminated groundwater diverted by a subsurface grout wall (approximately 1,350
feet in length) to a treatment vault. Groundwater treated using apatite.
East Fork Ninemile Creek Floodplain
IDEQ, Hecla
1994
Time-critical removal of -50,000 cy of flood plain tailings and contaminated
sediments with disposal at the Day Rock Repository. Stream reconstruction, riparian
stabilization, and revegetation.
Ninemile Creek Floodplain near
Blackcloud
SVNRT
1994
Time-critical removal of -44,000 cy of flood plain tailings and contaminated
sediments with disposal at the Day Rock Repository. Stream reconstruction, riparian
stabilization, and revegetation.
Day Rock Repository
SVNRT, IDEQ,
Hecla
1994
Approximately 94,000 cy of materials from the floodplain removals were placed on
top of the existing Day Rock repository and capped with native soils and growth
media.
Moon Creek
Silver Crescent and Charles Dickens
USFS
1998-2000
Non-time-critical removal of-130,000 cy of tailings, waste rock, contaminated soils,
and mill structures, with disposal at an on-site repository. Closure of four adits.
Stream relocation and habitat reconstruction along approximately 3,300 feet of Moon
Creek, and 10 acres of riparian revegetation.
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Bunker Hill Mining and Metallurgical Complex OU 3
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Part 2, Decision Summary
Section 2.0
Page 2-13
Table 2.3-2 (Continued)
Past Cleanup Actions for Ecological Protection
Site Niimo
Ki-spnnsihk-
.\»eiic\/r.nli(>
Diilcs of
Action
Di'MTiplion of Action
Pi lie ( ivok
Constitution Mine and Millsite
BLM
1998-
Present
Non-time-critical removal included removal of contaminated soils around the mill
with disposal at the Central Impoundment Area (CIA), and realignment of East Fork
Pine Creek (EFPC) away from the toe of the tailings pile. Most of the tailings and
waste rock dump are on private land and have not been addressed to date.
Denver Cr.
BLM
1996-2000
Time-critical removal of -5,200 cy of tailings and contaminated soils. No actions
have been conducted on the private portion of the pile. Stream channel stabilization.
Douglas Mine and Millsite
EPA
1996-1997
Time-critical removal of two existing tailings impoundments from the flood plain of
the EFPC. 25,000 cy of contaminated materials were removed and placed into a
temporary repository constructed east of Pine Creek Rd. near the mine.
Highland Creek Floodplain
BLM
1999
Time-critical removal of 8,100 cy major discrete tailings deposits along Highland
Creek on public lands.
Highland-Surprise
BLM
1999
Diversion of Highland Cr. to reduce erosion of the lower waste rock dump. Most of
the facilities at this site are on private land, thus no other actions have been taken to
date.
Sidney (Red Cloud)
BLM
1998-2000
Non-time-critical removal of contaminated soils around the mill foundations with
disposal at the CIA; run-on and run-off controls; and improvements to the upstream
culvert on Red Cloud Creek to control flow through the site and reduce downstream
erosion. Passive treatment of adit drainage with inflow prevention at the Sidney Shaft
in Denver Creek. Rock dump regraded and hydroseeded in 2000 to minimize erosion.
Amy-Matchless Millsite
BLM
1996-2000
Time-critical removal of -9,600 cy of tailings and contaminated soils in 1996 and
1997. In 1998, a non-time-critical removal action removed an additional 420 cy of
residual tailings. Disturbed area covered with soil and revegetated. Mine adit was
closed by backfilling. Waste rock dump regraded and revegetated.
Liberal King
BLM
1996-2000
Time-critical removal of -9,400 cy of tailings and contaminated soils in 1998, 99 cy
of millsite tailings and mill wastes were removed from the mill area. In 1999, non
time-critical removal of an additional 1,800 cy of tailings, regrading backfill of a dry
adit, import of growth medium, and revegetation. The 2000 actions included
extensive grading and planting of riparian vegetation.
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September 2002
Part 2, Decision Summary
Section 2.0
Page 2-14
Table 2.3-2 (Continued)
Past Cleanup Actions for Ecological Protection
Site Niimo
Responsible
.\iienc>/r.n(i(>
Diilcs of
Action
Description of Action
Nabob
BLM
1994-2000
Soil cover over the tailings pile and a portion of mill area; fence to limit access to the
millsite and tailings; channel improvements along Nabob Creek stabilize the channel
and prevent erosion of the tailings pile embankment.
Sou 111 l-'ork
South Fork Floodplain Removals
SVNRT
1998
Non-time-critical removals at several areas in the floodplain totaling about 128,000 cy
of tailings and contaminated soils.
South Fork above Elizabeth Park
SVNRT
1995
Tailings removal and construction of an armored levee with rock grade-control
structures to stabilize bank.
Moon Creek at Mouth (Elk Creek
Pond)
SVNRT;
USACE, EPA
1994;
2000
Limited tailings removal in 1994. Clean sand was imported for a recreational beach at
this swimming hole.
Time-critical removal of 28,000 cy of contaminated sediments and tailings in 2000.
I.omci- Cocur d'Alcnc Ri\cr
Cataldo Mission
CDA Tribe
1995
Removal of -700 cy of tailings and contaminated soils from traditional campground
areas in the vicinity of the Cataldo Mission.
Cataldo Boat Ramp
IDEQ
1996-1997
Placement of cabled log bank protection and brush wattling to reduce erosion and
planting of bushes in the vicinity of contaminated soils to discourage human contact
with the soils.
Dudley
SVNRT
1999
Pilot bank erosion project to evaluate effectiveness of rock berms in reducing bank
erosion cased by piping, or undercutting by boat wake. The project included minor
bank regrading and shaping along 750 feet of a straight portion of the river channel
near Dudley, with installation of riprap channel bank armoring and rock berms along
the overbank.
Medimont
IDEQ/Soils
Conservation
Service
1994
Placement of four types of bank erosion control: two with hay bales, two with riprap.
Subsequent monitoring indicated that the hay-bale methods were not effective in this
portion of the river.
Source: Compiled from Tables 1.5-20 through 1.5-26 of the Final Feasibility Study (USEPA 2001c).
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Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 3.0
Page 3-1
3.0 COMMUNITY PARTICIPATION
Throughout EPA's RI/FS activities leading up to this ROD, extensive efforts have been made to
inform and involve the public. EPA conducted the activities summarized in this section because
the agency believes that community involvement is a key element in developing a successful
cleanup plan.
In addition to the many activities discussed below, EPA has complied with the specific
requirements for public participation under CERCLA by publishing a Proposed Plan for public
comment in October, 2001. The Proposed Plan public comment period ran from October 29,
2001 to February 26, 2002. During the comment period, EPA held four public meetings.
Complete transcripts of these public meetings are included in the Administrative Record and are
available for public review in local information repositories. A Notice of Availability
summarizing the Preferred Alternative was mailed to approximately 1,000 Basin residents. EPA
also published newspaper advertisements in the Coeur d'Alene Press, the Idaho and Washington
editions of the Spokesman Review, the Shoshone News Press, and the St. Maries Gazette
announcing the availability of the Proposed Plan, the comment period and the public meetings.
The advertisements also briefly described the Preferred Alternative.
EPA released a draft Community Involvement Plan (CIP) for public review in October 1998 and
finalized the plan in early 1999. It described how EPA would share information about its
activities and how people could become involved and provide input as the cleanup plan was
being developed. In response to input from people in the Basin, EPA enhanced its community
involvement efforts by adding more information sharing and public input opportunities than
originally described in the CIP. A summary of EPA's community involvement activities is
provided below.
Community Liaison. In early 1999, EPA hired a full-time community liaison based in Coeur
d'Alene. The liaison is an on-scene resource who answers questions, acts as a conduit of
information from the community back to EPA staff and managers in Seattle, WA, makes
presentations to local organizations about EPA's work in the Basin and provides staff support to
the Citizens' Advisory Committee (CAC) RI/FS Task Force.
Comment Periods. Rather than having one public comment period when the Proposed Plan was
released, EPA provided four additional public comment periods on drafts of four documents
prior to the release of the Proposed Plan. The four documents were the draft HHRA, the draft
EcoRA, the draft RI and the draft FS. The comment period for each of these documents was
extended beyond 30 days upon request and EPA provided a written response to comments on
each of these documents. To make these documents easier for people to understand, EPA also
prepared executive summaries for each of these documents.
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September 2002
Part 2, Decision Summary
Section 3.0
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Progress Report. In April 2001, the governments involved in developing the Basin cleanup
plan distributed a progress report that was intended to give the public a sense of the priorities and
cleanup approaches that were likely to be included in the Proposed Plan. EPA conducted four
public meetings to update the public at the time the progress report was released.
Fact Sheets. During the RI/FS, EPA sent 10 fact sheets that announced major project milestones
to a mailing list of approximately 1,000 people. In addition, two fact sheets were included as
newspaper inserts in the Coeur d'Alene Press and Shoshone News Press. EPA also produced
and mailed a Notice of Availability that summarized the Preferred Alternative in the Proposed
Plan and provided information on the public meetings.
NewsBriefs. Beginning in fall 2000, EPA produced and either mailed or e-mailed 35 monthly
"NewsBriefs" to more than 200 people each. NewsBriefs is now being sent to a longer mailing
list of about 1,000 people. NewsBriefs provides updates from EPA and the many other state,
tribal, and local agencies doing work in the Basin. It also provides a calendar of events for
upcoming agency and community group meetings related to the Basin cleanup activities, and
lists documents recently added to information repositories.
Briefing Sheets. EPA provided eight "briefing sheets" which described environmental sampling
events in the Basin and the results of the sampling.
Resource manual. EPA provided about 100 resource manuals to citizen advisory group
members and local elected officials to help them understand the various elements of the cleanup
process and keep track of the written material they received from EPA.
Public Meetings, Workshops, Briefings with Elected Officials, and Meetings with Local
Organizations. EPA hosted or participated in more than 200 meetings with the general public,
elected officials, citizen groups, or community organizations since early 1999 (66 in 1999, 63 in
2000, 55 in 2001, and 15 so far in 2002). These include:
• 16 general public meetings or workshops, including three educational workshops
on the HHRA, EcoRA, and FS; and four workshops to preview the Proposed Plan
nearly three months prior to its release, in addition to the four formal public
meetings on the Proposed Plan
• 41 meetings with local elected officials and congressional staff
• 24 meetings with the CAC RI/FS Task Force and/or the CAC "core" membership
• 16 meetings with the Washington CAC
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Part 2, Decision Summary
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• EPA's Regional Administrator or EPA officials from Washington D.C. visited the
Basin 8 times and participated in 23 separate meetings
RI/FS Task Force. EPA supported the formation of the CAC's RI/FS Task Force and provided
staff support to this group for more than two years. This group assisted EPA in making sure
people in the Basin were well informed and knew how and when to get involved. The group also
provided valuable input during the RI/FS and development of the Proposed Plan.
Washington CAC. EPA worked with the Washington CAC in its effort to provide input on the
testing of Spokane River beaches and other elements of the RI/FS and Proposed Plan process.
State of Idaho's Consensus Building Process. EPA participated in and supported the State of
Idaho's Consensus Building Process. This intensive six-month process brought diverse interests
together to develop a range of common-ground recommendations on the priority areas for
cleanup in the Basin.
Information Repositories. EPA established five information repositories in Basin communities
where citizens can review detailed information about the cleanup work. The information at the
repositories includes documents available for public review and comment and many other
technical documents. The repositories were frequently advertised in fact sheets and newspaper
notices as well as in NewsBriefs.
Basin Website. EPA has maintained a website for the Basin project that allows people to access
technical documents, fact sheets, NewsBriefs, newspaper clippings and other resources directly
from their computers.
Cooperative Agreements. EPA provided more than $100,000 in grant money via two separate
cooperative agreements to counties and cities in the Basin. The grants were intended to allow
the communities in the Upper Basin and Lower Basin to hire technical experts to help them
provide input throughout the RI/FS process.
In addition to the above activities coordinated by EPA's Regional Office in Seattle, WA, during
2001, EPA's Community Involvement and Outreach Center in Washington D.C. hired a
contractor to conduct public surveys at several Superfund sites around the country. The Coeur
d'Alene Basin was one of the sites chosen to survey. The surveys were intended to gauge the
effectiveness of EPA's community involvement programs. Approximately 1,800 Basin residents
received the survey and 27 percent of those people returned the survey.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 4.0
Page 4-1
4.0 SCOPE AND ROLE OF THE SELECTED REMEDY
This section describes the scope and role of this Selected Remedy in relation to the overall site
cleanup strategy. Section 4.1 describes the relationship of the Coeur d'Alene Basin (OU 3) to
the Bunker Hill Box (OUs 1 and 2) and provides a description of each of the three OUs. Section
4.2 describes the relationship of the Selected Remedy to the long-term cleanup needs.
4.1 DESCRIPTIONS OF OPERABLE UNITS
EPA has identified three operable units in the Basin: the populated areas of the Bunker Hill Box
(OU 1); the non-populated areas of the Box (OU 2); and mining-related contamination in the
broader Coeur d'Alene Basin (OU 3). This ROD is focused on OU 3. Descriptions of the three
operable units are provided in this section.
RODs have been signed in 1991 and 1992. The 1991 ROD addressed the residential soils
component of OU 1. The 1992 ROD addressed OU 2 and the remaining components of OU 1.
In November 2001, an amendment to the OU 2 ROD was signed to address the long-term
management of acid mine drainage (AMD) from the Bunker Hill mine. In 1998, EPA initiated
an RI/FS for OU 3. A Proposed Plan for OU 3 was released for public comment in October 2001
(USEPA 200 le).
4.1.1 Operable Unit 1 (Populated Areas of the Bunker Hill Box)
The populated areas operable unit of the Bunker Hill Box (OU 1) includes residential and
commercial properties, ROWs, and public use areas in the towns of Kellogg, Wardner,
Smelterville, Pinehurst, and several smaller unincorporated communities. Cleanup activities
began in OU 1 as this was the area of greatest concern for human health exposure. In 1985, a
Lead Health Intervention Program (LHIP) was initiated by the Centers for Disease Control and
Prevention (CDC) and the Agency for Toxic Substances and Disease Registry (ATSDR) to
minimize blood lead levels in children through health education, parental awareness, and
biological monitoring. This ongoing program is administered by the Panhandle Health District
in conjunction with the Idaho Department of Health and Welfare (IDHW).
In 1986, 16 public properties (including city parks and school playgrounds) were cleaned up as
part of a CERCLA time-critical removal action. The yard soil removal program was initiated in
1989 as a CERCLA time-critical removal action to replace contaminated soils in yards of young
children at highest risk of lead poisoning. Since 1994, the yard soil removal program has been
implemented by the PRPs pursuant to the 1991 and 1992 RODs and 1994 Consent Decree. The
PRPs are scheduled to remediate at least 200 residential yards each year until all yards,
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Part 2, Decision Summary
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commercial properties, and ROWs with contaminated soils containing greater than or equal to
1,000 mg/kg of lead have been remediated to achieve a community-wide geometric mean of 350
mg/kg lead.
Remediating at least 200 residential yards each year is important because the pace of remediation
affects the potential for remediated parcels to be recontaminated by soil and dust from parcels
that have not been remediated.
House dust, long recognized as a primary source of lead exposure among children, is being
monitored through the LHIP. Should house dust lead levels remain elevated following
completion of yard soil remediation, homes with dust lead concentrations greater that 1,000
mg/kg will be evaluated for interior remediation. EPA, the State of Idaho, and the U.S. Army
Corps of Engineers are conducting a House Dust Pilot Study. The purpose of the study is to
evaluate three methods of cleaning homes to determine the most effective method for reducing
contaminated dust in homes. Eighteen homes in Smelterville were cleaned and sampled in 2000
and 2001. The analysis of the study results is ongoing. If cleanup of home interiors is deemed
necessary after completion of remediation, the results from the study will be considered when
selecting the most effective cleaning method and to estimate cleaning costs (IDEQ 2001).
A five-year review of OU 1 was completed in 2000, which further describes OU 1 cleanup
activities.
4.1.2 Operable Unit 2 (Non-Populated Areas of the Bunker Hill Box)
The non-populated areas operable unit of the BHSS (OU 2) includes the former industrial
complex and mine operations area, river floodplain, hillsides, various creeks and gulches, surface
water and groundwater, the Central Impoundment Area (CIA), and the Bunker Hill Mine and
associated acid mine drainage (AMD). Site PRPs performed various removal activities pursuant
to several orders prior to the 1992 ROD, including smelter stabilization efforts from 1989 to
1993, and hillsides revegetation and fugitive dust control efforts from 1990 to 1992.
Following completion of the ROD in 1992, PRPs signed a consent decree with EPA to perform
cleanup activities in limited areas of OU 2, including the UPRR ROW, and the A-4 gypsum
pond. In 1995, EPA and the State of Idaho entered into a State Superfund Contract to perform
the remaining site remedial actions. Cleanup actions addressed in the ROD included a series of
source removals, surface capping, reconstruction of surface water creeks, demolition of
abandoned milling and processing facilities, engineered closures for waste consolidated on site,
revegetation efforts, and surface water and groundwater controls in the Bunker Hill Box and
treatment in a constructed wetlands treatment system.
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Part 2, Decision Summary
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There have been two ROD amendments (September 1996 and November 2001) and two
Explanation of Significant Differences (January 1996 and April 1998) since the ROD was
completed in 1992. A five-year review of OU 2 was completed in 2000. The review document
further describes OU 2 cleanup activities.
In the 1995 Bunker Hill State Superfund Contract, EPA and the State of Idaho agreed to a two-
phased site implementation strategy. Phase I largely addresses source removals aimed at
consolidating extensive contamination from various areas of the site. Phase I cleanup activities
were mostly complete in 2001. Phase II will address site surface water and groundwater cleanup
and will be implemented following completion of source control and removal activities and
evaluation of the effectiveness of these activities in meeting water quality improvement
objectives.
OU 2 also includes the Bunker Hill Mine and associated AMD. The AMD contains very large
loads of metals. The existing central treatment plant (CTP) has not been significantly upgraded
since it was built in 1974, is not capable of consistently meeting current water quality standards,
and requires repair and replacement to prevent equipment failure.
The 1992 non-populated areas ROD did not select response actions for the mine water. The
ROD, therefore, did not address control of AMD from the Bunker Hill Mine or operation of the
CTP in any significant way. The ROD briefly addressed the mine water by requiring that it
continue to be treated in the CTP prior to discharge to a wetlands treatment system for removal
of residual metals. During studies conducted between 1994 and 1996 by the United States
Bureau of Mines, the wetlands treatment system was found to be incapable of meeting the
treatment levels established in the ROD. The 1992 ROD did not contain or otherwise identify
any plans for the control or long-term management of the mine water flows. The ROD also did
not address the long-term management of treatment residuals (sludge) from the CTP, which are
currently pumped into an unlined pond on the CIA. At current disposal rates it is estimated that
the pond will be filled in 3 to 5 years.
Additional remedies for the Bunker Hill AMD were selected in the November 2001 amendment
to the OU 2 ROD. These remedies include:
• AMD source control to reduce the quantity of surface water entering the mine and
AMD generated within the mine
• Temporary AMD storage in an existing lined surface pond located at the CTP or
within the mine (for times when the treatment plant is shut down for maintenance
or repairs or when the mine water flow exceeds treatment capacity)
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Part 2, Decision Summary
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Page 4-4
• AMD treatment in an upgraded treatment plant
• Management of treatment residuals (sludge)
4.1.3 Operable Unit 3 (Coeur d'Alene Basin)
At the time the 1992 non-populated areas ROD was written, it was widely recognized that
mining-related contamination in the Basin was not limited to the areas within the Bunker Hill
Box. Actions selected in the ROD did not address sources of contamination outside of the Box.
To address contamination and water quality issues in the broader Coeur d'Alene Basin, EPA, the
State of Idaho, the Coeur d'Alene Tribe, and other federal, state and local agencies formed the
Coeur d'Alene Basin Restoration Project. The purpose of this project was to integrate water
quality improvement programs in the Basin through coordination of the federal regulatory
authorities under the Clean Water Act, CERCLA, RCRA, and other state, local, and tribal
programs. However, the Coeur d'Alene Basin Restoration Project had limited success as a
systematic approach to addressing contamination in the Basin.
The first comprehensive study of human health effects outside of the Box was conducted in 1996
by the IDHW and the ATSDR (IDHW 2000a). The study indicated excessive levels of lead
absorption by children.
In September 1996, the United States District Court for the Western District of Washington
ordered EPA and the State of Idaho to develop a schedule for completion of total maximum daily
loads (TMDLs) for all water-quality impaired streams identified by the state, including the Coeur
d'Alene River Basin. TMDL development was initiated in 1998. In August 2000, a TMDL for
dissolved cadmium, lead, and zinc in surface waters of the Basin was jointly released by EPA
and the State of Idaho.5 The TMDL establishes waste load allocations for discrete point sources
and load allocations for non-discrete sources. It has long been recognized that non-discrete
sources are the primary sources of metals in surface water in the Basin. The CERCLA remedial
process was identified as the most effective tool to address these non-discrete sources.
Because of the presence of environmental and human health impacts in areas outside of the Box
and the limitations of the existing authorities to deal with these impacts, EPA initiated a RI/FS
for the Coeur d'Alene Basin in 1998. The final EcoRA was released in May 2001, and the final
HHRA was released in July 2001. In October 2001, the final RI and FS were released. Also in
October 2001, the Proposed Plan was released for public comment. The public comment period
ended on February 26, 2002.
5 On September 4, 2001, a district court judge for the State of Idaho invalidated the TMDL on the procedural
grounds that the IDEQ had not engaged in formal rulemaking when adopting the Basin TMDL. The impact of this
court decision on TMDL implementation is currently unclear, and the final status of the TMDL has not yet been
determined.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 4.0
Page 4-5
The Selected Remedy for OU 3 includes remedial actions for 1) protection of human health in
the communities and residential areas, including identified recreational areas, of the Basin
upstream of Coeur d'Alene Lake (the Upper Basin and Lower Basin), 2) protection of the
environment in the Upper Basin and Lower Basin, and 3) protection of human health and the
environment in areas of the Spokane River. At present, the risks to persons, including Spokane
tribal members, and others who may practice a subsistence lifestyle in the Spokane River area
have not been quantified. EPA and the Spokane Tribe are cooperating in planning additional
testing and studies that will be implemented to evaluate the potential exposures to subsistence
users. The results of those tests and studies will determine appropriate future response actions to
be taken, if any.
The Selected Remedy includes a complete remedy for protection of human health in the
communities and residential areas, including identified recreational areas, of the Upper Basin and
Lower Basin. Certain potential exposures outside of the communities and residential areas of the
Upper Basin and Lower Basin are not addressed by this ROD, and will continue to present risks
of human exposure to hazardous substances. These potential exposures impacting human health
include:
• Recreational use at areas in the Upper Basin and Lower Basin where cleanup
actions are not implemented pursuant to this ROD
• Subsistence lifestyles, such as those traditional to the Coeur d'Alene and Spokane
Tribes
• Potential future use of groundwater that is presently contaminated with metals.
For environmental protection, the Selected Remedy identifies approximately 30 years of
prioritized actions in areas of the Basin upstream of Coeur d'Alene Lake. During this period,
EPA will evaluate the effectiveness and protectiveness of these remedial actions as well as the
technical practicability of attaining applicable or relevant and appropriate requirements
(ARARs), in particular ambient water quality standards for lead, zinc, and cadmium. During the
five-year review process and at the end of this approximately 30-year period, EPA will evaluate
and decide whether any additional remedial actions are necessary to attain ARARs or to provide
for the protection of human health and the environment, and whether any ARAR waivers should
be applied.
EPA expressly recognizes that after the selected remedial actions are implemented, conditions in
the Upper and Lower Basin may differ substantially from EPA's current forecast of those future
conditions, which is solely based on present knowledge. The tremendous amount of additional
knowledge that will be gained by the end of this period through long-term monitoring and five-
year review processes may provide bases for future ARAR waivers. In addition, this new
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Part 2, Decision Summary
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information and advances in science and technology may allow for additional actions to achieve
ARARs and protect human health and the environment in a more cost-effective manner.
The Selected Remedy does not include remedial actions for Coeur d'Alene Lake. State, tribal,
federal, and local governments are currently in the process of implementing a lake management
plan outside of the Superfund process using separate regulatory authorities.
For the Spokane River, the Selected Remedy includes a complete remedy for protection of
human health upstream of Upriver Dam and a complete remedy for protection of the
environment between Upriver Dam and the Washington/Idaho border.
4.2 SITE CLEANUP STRATEGY
The remedy for OU 3 selected in this ROD is consistent with the overall cleanup strategy for the
Basin. Cleanup activities began in OU 1, the area of the most imminent public health threats.
The second priority for cleanup was OU 2. Cleanup activities in OU 2 are being implemented in
two phases. Phase I addresses consolidating extensive contamination from various areas of the
site. Phase II will address site surface water and groundwater cleanup.
This ROD extends the cleanup into the broader Basin (OU 3) and selects priority cleanup actions
that will take approximately 30 years to implement. EPA recognizes that the State of Idaho has
not concurred in the selection of any remedial action beyond those selected in this ROD.
Furthermore, after implementation of the remedies selected by this ROD, EPA commits not to
take or select any additional remedial actions in the Upper Basin or Lower Basin without first
consulting with the State of Idaho. EPA will continue to work with the regulatory stakeholder
group, which was instrumental in developing the actions selected in this ROD.
State legislation under the Basin Environmental Improvement Act established the process for the
formation of the Basin Environmental Improvement Project Commission. The Commission
includes federal, state, tribal, and local governmental involvement. EPA anticipates working as a
member of the Commission. Actions selected in this ROD will be integrated with those selected
in the Box to effectively clean up the Coeur d'Alene Basin.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-1
5.0 SITE CHARACTERISTICS
This section describes the geography, topography, and nature and extent of contamination in the
Coeur d'Alene Basin.
5.1 GEOGRAPHY AND TOPOGRAPHY
The Coeur d'Alene Basin RI/FS study area includes the Coeur d'Alene River Basin, Coeur
d'Alene Lake, and the Spokane River. The contamination is mostly limited to floodplain areas,
discrete mine and mill sites, and fill areas.
Based on the results of the RI (USEPA 2001b), the HHRA (IDHW 2001a), and the EcoRA
(USEPA 2001a), the FS study area focused on the areas with the greatest human health and
ecological risks. The study areas for development of human health and ecological alternatives
are organized differently and are defined in the following sections.
5.1.1 Geographical Organization of the Human Health Alternatives
For development of the human health alternatives, eight major areas were identified based on
projected human exposure scenarios and public use patterns. These specific areas are defined in
the HHRA. For the purposes of this ROD, these areas have been consolidated into two principal
geographic areas where the selected human health remedy will be implemented: the Upper
Basin and the Lower Basin.
The Upper Basin generally includes mining-contaminated areas within the South Fork of the
Coeur d'Alene River and its tributaries east of Cataldo.
The Lower Basin includes all of the Coeur d'Alene River west of Cataldo to Harrison, at the
mouth of Lake Coeur d'Alene.
5.1.2 Geographical Organization of the Ecological Alternatives for the Upper Basin and
Lower Basin
For development of ecological alternatives, two areas of the Basin upstream of Coeur d'Alene
Lake were identified based on geomorphology, habitats, types of waste sources, mechanisms of
release and transport of waste, and the natural resources affected by the release of wastes: the
Upper Basin and the Lower Basin.
The Upper Basin encompasses the steep mountain canyons of the South Fork and its tributary
gulches. The Upper Basin is the source area for most of the mining-related waste materials and
includes the Canyon Creek, Ninemile Creek, Big Creek, Moon Creek, and Pine Creek tributary
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Bunker Hill Mining and Metallurgical Complex OU 3
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Part 2, Decision Summary
Section 5.0
Page 5-2
watersheds. The Upper Basin drains an area of 300 square miles. The channel and riparian zone
of the South Fork and certain of its tributaries have undergone extensive channelization and other
alterations as a result of mining-related activities and other anthropogenic activities, including
the construction of the 1-90 freeway.
The Lower Basin includes the lower Coeur d'Alene River, the lateral lakes, and extensive
floodplain wetlands. Below Cataldo, the river flows into a broad, flat valley and takes on a
meandering, depositional character with a fine sediment bottom. From Rose Lake downstream,
the river surface elevation is controlled by Post Falls Dam on the Spokane River near the outlet
from Coeur d'Alene Lake. Much of the tailings released to streams in the Upper Basin were
transported to and deposited within the river channel and floodplains in the Lower Basin, largely
during flood events.
For the purposes of the RI/FS, the Upper Basin and Lower Basin were further subdivided into
one or more segments based on geomorphology, habitats, types of waste sources, mechanisms of
release and transport of waste, and the natural resources affected by the release of wastes.
Individual mining-related source areas in the Upper Basin were also identified based on mapping
conducted by the BLM.
5.1.3 Coeur d'Alene Lake
Coeur d'Alene Lake encompasses 49.8 square miles at its normal full-pool elevation (2,128 feet
above sea level), with a maximum water depth of 209 feet. The 2,128-feet elevation is the level
defined by Avista's FERC license as the maximum permitted lake level. Its principal tributaries
are the St. Joe's River and the Coeur d'Alene River. The lake has a drainage area of 3,741
square miles. The discharge from the lake forms the Spokane River. Coeur d'Alene Lake is a
natural lake, but its elevation is controlled by the Post Falls Dam. The lake is classified as
oligotrophic. A large volume of metals-contaminated sediment has been deposited on the lake
bottom.
5.1.4 Spokane River
The Spokane River flows from Coeur d'Alene Lake and is dammed at six locations above its
terminus at Lake Roosevelt. The river bed primarily consists of coarse gravel and cobbles, and
the floodplain and riparian zone are relatively narrow. Metals contamination is present in
depositional areas within the river's floodway. Priority depositional areas have been identified
by the Washington Department of Ecology between the Washington-Idaho state line and Upriver
Dam for environmental protection and upstream of Upriver Dam to the lake for human health
protection.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-3
At present, the risks to persons, including Spokane tribal members, and others who may practice
a subsistence lifestyle in the Spokane River area have not been quantified. EPA and the Spokane
Tribe are cooperating in planning additional testing and studies that will be implemented to
evaluate the potential exposures to subsistence users. The results of those tests and studies will
determine appropriate future response actions to be taken, if any.
5.2 NATURE AND EXTENT OF CONTAMINATION
Metals related to mining, milling, and smelting activities are present in soil, sediment, surface
water, groundwater, and vegetation in the Basin. Sections 5.2.1 through 5.2.4 describe the nature
and extent of contamination in the community and residential areas of the Upper Basin and
Lower Basin, in non-community areas of the Upper Basin and Lower Basin, in Coeur d'Alene
Lake, and in the Spokane River floodway upstream of the Spokane Indian Reservation.
5.2.1 Nature and Extent of Contamination Affecting Human Health in the Community
and Residential Areas of the Upper Basin and Lower Basin
The primary media of concern for human health are:
• Contaminated soil where it occurs in residential yards, street rights-of-way,
commercial and undeveloped properties, and common areas, and airborne dust
generated at these locations
• Contaminated house dust, originating primarily from contaminated soil; interior
house paint is also a potential source of lead
• Drinking water from local wells or surface water
• Contaminated aquatic food sources (e.g., fish)
• Contaminated homegrown vegetables
• Contaminated floodplain soil, sediments, and vegetation
People in the Basin can be exposed to chemicals of potential concern (COPCs) by ingesting soil,
breathing dust, drinking water, and eating contaminated fish or homegrown vegetables. The
COPCs for protection of human health are:
• Seven metals in soil: antimony, arsenic, cadmium, iron, lead, manganese, and zinc
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-4
• Seven metals in house dust: antimony, arsenic, cadmium, iron, lead, manganese,
and zinc
• Five metals in groundwater: antimony, arsenic, cadmium, lead, and zinc
• Five metals in surface water: arsenic, cadmium, lead, manganese, and mercury
• Two metals in tap water: lead and arsenic
Although fish and vegetables were not screened for COPCs, indicator metals were selected for
these based on toxicity and presence in the Basin. The selected indicator metals for fish
consumption were cadmium, lead, and mercury; and for vegetable consumption were arsenic,
cadmium, and lead. Although not considered a primary medium of concern in the HHRA,
interior and exterior lead-based paint contributes to lead concentrations in yard soil and house
dust. These are potentially important sources that are addressed on a case-by-case basis.
Exposures to lead in soil and dust from the home and surrounding communities are the primary
human health concerns in the Basin. Table 5.2-1 shows geometric mean, arithmetic mean,
minimum, and maximum lead concentrations in sampled yard soil and house dust in the Upper
Basin and Lower Basin. Tables 5.2-2 and 5.2-3 present minimum, maximum, arithmetic mean,
and geometric mean results for the seven COPCs in soil and house dust, respectively.
The identification of chemicals of concern (COCs) for protection of human health is described in
Section 7.1. Minimum, maximum, and exposure point COC concentrations for various exposure
scenarios and exposure points are also summarized in Section 7.1.
Drinking water obtained from private, unregulated sources is a potential exposure route. Table
5.2-4 presents the results of first-draw and flushed-line samples collected from private,
unregulated drinking water sources in the Basin. Although groundwater contamination is
observed in the Basin, an insufficient number of monitoring wells have been installed to fully
characterize the nature and extent of groundwater contamination.
Soil, sediment, and surface water are impacted at beaches and recreational areas. Figure 5.2-1
shows graphically the widespread distribution of lead concentrations above EPA's emergency
action level (2,000 mg/kg) for protection of human health in soil and sediment samples in the
Basin. The figure shows four concentration ranges:
• 0 to 175 mg/kg (175 mg/kg equals the 90th percentile of the Upper Basin
background soil lead concentration [Gott and Cathrall 1980].)
175 mg/kg to 500 mg/kg
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-5
• 500 mg/kg to 2,000 mg/kg
• Greater than 2,000 mg/kg
Figure 5.2-2 shows average metal concentrations in surface soil and sediment and average metal
loads and concentrations in surface water in the Upper Basin and Lower Basin.
5.2.2 Nature and Extent of Contamination Affecting Ecological Receptors in the Upper
Basin and Lower Basin
Contaminated media that potentially affect ecological receptors are surface water, soil, and
sediment. In addition, groundwater is important as a pathway for migration of metals to surface
water. The chemicals of ecological concern (COECs) for ecological protection are:
• Cadmium, copper, lead, and zinc in surface water
• Arsenic, cadmium, copper, lead, and zinc in soil
• Arsenic, cadmium, copper, lead, mercury, silver, and zinc in sediment
The identification and concentrations of COECs for protection of ecological receptors are
described in Section 7.2. Cadmium, lead, and zinc are pervasive in all environmental media and
generally present higher risks to ecological receptors than arsenic, copper, mercury, and silver.
Therefore, cadmium, lead, and zinc are the focus of the discussion of the nature and extent of
contamination presented in this section of the ROD.
To help characterize the nature and extent of contamination and to develop remedial alternatives,
the contaminated media were grouped by "source type" in the FS. These source types are based
on the mining-related primary sources (tailings, waste rock, and adit drainage) and the secondary
sources, or impacted media (floodplain sediments, river banks and beds, wetlands, lateral lakes,
dredge spoils, and lake bottom sediments) present in the Basin. Table 5.2-5 presents an
overview of the quantities of impacted materials by source type in the Basin.
Upper Basin
The Upper Basin is the primary source of dissolved metals in the river system. Tables 5.2-6 and
5.2-7 show estimated average (expected) values of concentrations and loads (the amount of metal
transported in a stream, in pounds per day), respectively, for dissolved cadmium, total lead, and
dissolved zinc at sampling locations in the Basin. The estimated average values were calculated
from surface water data collected during the period of 1991 to 1999 (USEPA 2001c).6 The
estimated average dissolved zinc load in the South Fork just above the confluence with the North
6 At each sampling location, the metals concentrations and loads vary in time. A coefficient of variation (CV) is
used to measure that variability. A high CV indicates relatively high variability relative to sampling mean.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-6
Fork (South Fork at Pinehurst) is about 79 percent of the load that discharges to the lake (Lower
Coeur d'Alene River at Harrison). Figure 5.2-3 shows the estimated average concentrations and
loads of dissolved zinc in the river and tributaries in the Basin. The figure shows that zinc
concentrations are substantially greater than 10 times the AWQC7 in parts of the South Fork and
some of its major tributaries.
The estimated average concentrations of dissolved cadmium, total lead, and dissolved zinc in the
South Fork at Pinehurst are 9.1 (J,g/L, 56 (J,g/L, and 1,430 (J,g/L, respectively. Based on the
estimated average values, about 1,550 pounds per day of dissolved zinc (53 percent of the total
Upper Basin load) comes from sources inside the Bunker Hill Box and about 1,370 pounds per
day of dissolved zinc (47 percent of the total Upper Basin load) comes from sources in the Upper
Basin outside of the Bunker Hill Box.
Impacted sediments and associated groundwater in the valley fill aquifers of the Upper Basin are
the largest sources of dissolved metals loading in the river and streams. Figure 5.2-4 shows the
estimated proportions of the dissolved zinc load in the South Fork at Pinehurst (not including
sources within the Bunker Hill Box) that are derived from impacted sediments and associated
o
groundwater, tailings, waste rock, and adit drainage. An estimated 71 percent of the load is
derived from impacted sediments and associated groundwater. Surface water and groundwater
percolates through the tailings-impacted sediments and dissolves metals. The water discharges
into the streams and rivers, carrying the dissolved metal load with it. Metals loading is enhanced
by the relatively large degree of surface water/groundwater interaction that occurs in some parts
of the Upper Basin. In areas where the valley floor widens, streams lose water to the valley fill
aquifer ("losing reach"). In areas where the valley floor constricts, groundwater discharges back
into the streams ("gaining reach"), carrying additional metals load. The USGS studied the
surface water/groundwater interaction (Barton 2000). Figure 5.2-5 shows the results of the study
in lower Canyon Creek in September 1999. These studies show that most of the dissolved zinc
load in the study areas was discharged to the streams in the gaining reaches.
An estimated 7 million cubic yards (cy) of tailings-impacted sediments are present in the Upper
Basin (CSM Units 1 and 2), including an estimated 3 million cy of sediments that potentially
cannot be accessed for excavation because they are beneath the 1-90 embankment, other roads, or
residential or commercial structures. In addition to the estimated 7 million cy of sediments
directly impacted by tailings, analysis of deeper sediments samples indicates metals
7 The national recommended water quality criteria, or ambient water quality criteria (AWQC), were used in the
RI/FS as metrics to quantify existing surface water quality characteristics and the effectiveness of remedial actions
for surface water. The values of AWQC used in the RI/FS are the EPA-approved Idaho and Washington water
quality standards (Tables 8.2-2, 8.2-3, and 8.2-4). The national recommended water quality criteria have been
updated for zinc (in 1999) and cadmium (in 1999 and 2000).
8 Percentages of dissolved zinc load were estimated by combining the estimated volumes of source materials with
the relative loading potentials of the source materials, as described in U SEP A 200 If, Probabilistic Analysis of Post-
Remediation Metal Loading.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-7
concentrations generally exceed background concentrations to depths of 10 to 30 feet. These
deeper sediments are potentially an important secondary source of metals.
Relatively little of the dissolved metals in the river system comes from discrete sources. Discrete
sources include NPDES-permitted discharges (including the treatment plant for the Bunker Hill
mine-water discharge) and unpermitted discrete discharges (adit and seep discharges). As shown
in Figure 5.2-6, the estimated loads from the discrete discharges account for only about 8 percent
of the estimated dissolved zinc load in the South Fork at Pinehurst.
Based on mapping conducted by BLM (BLM 1999), approximately 2,850 acres of land have
been disturbed by mining-related activities or deposition of mining-related wastes in the Upper
Basin (not including areas within the Bunker Hill Box). Approximately 295 acres of disturbed
area were identified by BLM as riparian. Approximately 1,200 acres of other impacted
floodplain areas were identified by BLM.
Lower Basin
In the Lower Basin, erosion of river banks and beds is a major source of metals, particularly lead,
entering the Coeur d'Alene River. There are an estimated 1.8 million cy of impacted bank
materials and an estimated 20.6 million cy of impacted bed sediments (including an estimated 3
million cy of bed sediments in the river delta downstream of Harrison) subject to erosion. The
average concentration of lead in over 2,000 non-random sediment samples within the floodplain
collected in the Lower Basin is 3,100 mg/kg.
The increase in total lead load below the confluence of the North Fork and South Fork is about
1,040 pounds per day, or about 69 percent of the load that discharges to the lake (Figure 5.2-7).
Lead tends to bind more strongly to soil particles than does zinc, and the lead load is largely due
to erosion of soil and sediment, particularly during high-flow periods. As a result, the total lead
loads display a large variability with time. During low-flow periods, total lead loads as low as
30 pounds per day have been measured in the Coeur d'Alene River at Harrison. By contrast,
during the 100-year flood event in February 1996, an estimated 1,400,000 pounds of lead were
discharged to Coeur d'Alene Lake in a single day. The estimated average concentrations of
dissolved cadmium, total lead, and dissolved zinc in the Coeur d'Alene River at Harrison,
calculated from surface water data collected during the period of 1991 to 1999, are 1.9 (J,g/L, 52
[j,g/L, and 344 (J,g/L, respectively.
Lower Basin wetlands, 100-year floodplains, and lateral lake sediments are the major sources of
metals ingested by waterfowl and other animals. Based on geostatistical analysis, there are about
18,300 acres of floodplain sediments that contain more than 530 mg/kg of lead in the surficial
sediments, the lowest observed adverse effects level (LOAEL) for waterfowl. The area
containing more than 530 mg/kg of lead represents an estimated 95 percent of the 19,200 acres
of floodplain habitat present in the Lower Basin. There are about 15,400 acres of floodplain
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-8
sediments that contain more than 1,800 mg/kg of lead, the mortality threshold concentration for
waterfowl. The area containing more than 1,800 mg/kg of lead represents an estimated 80
percent of the 19,200 acres of floodplain habitat present in the Lower Basin. Table 5.2-8 shows
the total areas and lead-impacted areas of wetland, lake, and riparian habitat in 27 wetland units
identified by the USFWS in the Lower Basin.
The Lower Basin includes the Cataldo/Mission Flats area, where tailings were dredged from the
river and placed within the 100-year floodplain from 1932 to 1967. An estimated 13 million cy
of tailings-impacted dredge spoils cover about 680 acres at this location.
5.2.3 Nature and Extent of Contamination in Coeur d'Alene Lake
The beaches and wading areas adjacent to Coeur d'Alene Lake were sampled in 1998 and were
found to be safe; i.e., concentrations of metals did not exceed risk-based levels for recreation.
The only exception is Harrison Beach, which has been remediated as part of the UPRR removal
action. Based on existing information, EPA has no reason to believe that mining contamination
is present in the residential and commercial areas in the cities of Coeur d'Alene, Post Falls, and
Harrison.
The water in Coeur d'Alene Lake meets the safe drinking water standards for metals, except
when discharge from the Coeur d'Alene River is high (e.g., during high spring run-off or during
flood events), which causes short-term lead concentrations that exceed the drinking water
standard. The water in the lake exceeds the water quality standards for protection of aquatic life,
which are more stringent than the drinking water standards, for cadmium and zinc and
intermittently for lead.
A large volume of metals-impacted sediment has been deposited in Coeur d'Alene Lake. There
are an estimated 44 to 50 million cy of contaminated sediments at the bottom of the lake.
Studies by the USGS suggest that, under current lake conditions, there may be some movement
of the metals from the sediment into the water column in the dissolved phase. The rate of release
of metals in the sediments into the water column could increase if the lake water quality
deteriorates due to nutrient enrichment. Currently, however, more metals enter the lake annually
from the Coeur d'Alene River than flow out of the lake into the Spokane River. Table 5.2-9
shows the net retention of metals in the lake, where retention is the difference between the metal
load into the lake and the load out of the lake, expressed as a percentage of the load into the lake.
Cadmium retention ranged from 47 to 56 percent and averaged 52 percent. Lead retention
ranged from 82 to 92 percent and averaged 89 percent. Zinc retention ranged from 31 to 43
percent and averaged 38 percent.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-9
5.2.4 Nature and Extent of Contamination in the Spokane River Upstream of the
Spokane Indian Reservation
Contaminated media that potentially affect humans are soil and sediment at shoreline and
sediment depositional areas. The COCs for protection of human health are arsenic and lead. The
identification and concentrations of COCs for protection of human health are described in
Section 7.1.
The beaches and wading areas adjacent to the Idaho portion of the Spokane River were sampled
in 1998 and were found to be safe; i.e., concentrations of metals did not exceed risk-based levels
for recreation. Sediment depositional areas in the State of Washington portion of the Spokane
River were sampled in 1998 and 1999 (Groisbois 1999), summer/fall 1999 (USEPA 2000d), and
August/September 2000 (USEPA 2001i). Several depositional areas were found to contain lead
and/or zinc at concentrations exceeding the risk-based levels. These areas are discussed in
Section 7.1.3.
The water in the Spokane River meets the safe drinking water standards for metals.
Contaminated media that potentially affect ecological receptors are surface water, soil, and
sediment. The COPECs for protection of ecological receptors are:
• Cadmium, copper, lead, and zinc in surface water
• Arsenic, cadmium, copper, lead, and zinc in soil
• Arsenic, cadmium, copper, lead, mercury, silver, and zinc in sediment
The identification of COECs for protection of ecological receptors is described in Section 7.2.
Figures 5.2-8, 5.2-9, and 5.2-10 present concentrations of cadmium, lead, and zinc, respectively,
measured in 63 Spokane River sediment samples. Based on these data, about 25 percent of
samples contained cadmium above the upper background concentration, about 82 percent of
samples contained lead above the upper background concentration, and about 90 percent of
samples contained zinc above the upper background concentration.9 The average concentration
of lead in 265 sediment samples collected in the Spokane River floodway between Coeur
d'Alene Lake and Long Lake is 400 mg/kg.
Because there are relatively few depositional areas along the Spokane River, the volume of
contaminated sediments is small compared to the Upper Basin and Lower Basin. An estimated
volume of 260,000 cy of contaminated sediments are present upstream of Upriver Dam.
9 90th percentile upper background concentrations were estimated by Ecology using the 2 millimeter and finer
fraction of upland soil samples (WDOE 1994).
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-10
Additional contaminated sediments are present downstream of Upriver Dam, but have not been
quantified.
Surface water in the Spokane River has been impacted by metals including particulate lead
transported into the Spokane River, particularly during winter storm events and spring runoff. In
total metals analysis of samples from the Spokane River analyzed for the RI, 21 percent
contained cadmium exceeding a screening level of 0.9 |ig/L, 48 percent contained lead exceeding
a screening level of 0.66 |ig/L, and 68 percent contained zinc exceeding a screening level of 30
|ig/L,10 The estimated average concentrations of total lead and dissolved zinc in the Spokane
River at Post Falls, calculated from surface water data collected during the period of 1991 to
1999, are 2.1 |ig/L, and 58 |ig/L, respectively. Dissolved cadmium was not detected.
Transport of particulate lead into the Spokane River, particularly during winter storm events and
spring runoff, has resulted in deposition of lead-contaminated sediments in shoreline and
subaqueous depositional areas and periodic exceedances of lead AWQC.
10 The screening levels for lead and cadmium are equal to the federal AWQC for these metals for a hardness equal to
30 mg CaC03/L. The screening level for zinc is a risk-based concentration for protection of aquatic plants.
-------
\
4.
y \
Figure 5.2-1
Range of Lead Concentrations
in Surface Soils and Sediments
in the Coeur d'Alene River Basin
Legend
~ CITIES
STREAMS
¦¦ RIVERS/LAKES
'> FLOOD PLAIN
Lead Concentration Ranges
(inpptn)
~ 0-175
A 175 - 500
O 500-2000
+ >2000
Idaho
Location Map
Notes:
1) Base map coverages obtained
from the Bureau of Land Management
(BLM) and The Coeur d' Alene Indian Tribe.
2) Lead concentrations obtained
from the following sources:
McCully Frick and Gilman
RCG Hagler, Bailly Sampling Data
URS Greiner WoodwaraClyde
USGS
USFW
SCALE: 1:300000
N
+
5 Miles
027-RI-C9-102Q
Coeur d' Alene Basin RI/FS
RECORD OF DECISION
oERA
REGION 10
Document Control Number
4162500.07099.05 a
EPA No. 2.9
Project: n:\projectsVrod\rod-01 03.apr
VIEW: Pb sediments
LAYOUT: Fig 5.2-4B-Size
05/02/02
This map is based on Idaho
State Plane Corrdinates West Zone,
North American Datum 19B3
Date of Plot May 02,2002
-------
SR50
Pb 2.12 156
Zn 57.6 3,640
MidGradSeg04
Qty
Avg
Surface Soil (mg/kg)
Total Lead
7
61800
Total Zinc
7
2140
Sediment (mg/kg)
Total Lead
23
3640
Total Zinc
23
2880
MidGradSeg02
Qty
Avg
Surface Soil (mg/kg)
Total Lead
20
12600
Total Zinc
16
6650
Sediment (mg/kg)
Total Lead
87
9330
Total Zinc
87
5960
NMSeg02
Qty
Avg
Surface Soil (mg/kg)
Total Lead
60
8520
Total Zinc
63
11800
Sediment (mg/kg)
Total Lead
6
2320
Total Zinc
6
21900
LCDRSeg03
Qty
Avg
Surface Soil (mg/kg)
Total Lead
43 '
3660
Total Zinc
36
4480
Sediment (mg/kg)
Total Lead
233
4000
Total Zinc
234
3830
Pb 56
Zn 1430
2.920
^wfef
LCDRSeg05
Qty
Avg
Surface Soil (mg/kg)
Total Lead
46
3020
Total Zinc
31
2840
Sediment (mg/kg)
Total Lead
433
2000
,TotalZinc
433
1540
LC55
Pb 35.1 1,750
Zn 263 4,200
LC50
Pb 20.9
Zn 354
708
3,488
PC305
Pb 4.6 12
Zn 112 90
S .
-0.
Later#
NMSeg04
Qty
Avg
Surface Soil (mg/kg)
Total Lead
5
3990
Total Zinc
5
2630
Sediment (mg/kg)
Total Lead
13
6000
Total Zinc
13
5070
SF268
Pb 32 30
Zn 976 1,204
ij LC60
] Pb 51.6 1,510
I Zn 344 3,736
LCDRSegOl
Qty
Avg
Surface Soil (mg/kg)
Total Lead
47
2350
Total Zinc
39
1510
Sediment (mg/kg)
Total Lead
85
2770
Total Zinc
85
1590
LCDRSeg06
Qty
Avg
Surface Soil (mg/kg)
Total Lead
3
2810
Total Zinc
NA
NA
Sediment (mg/kg)
Total Lead
92
4050
Total Zinc
92
3160
NM305
Pb 92.1
13
Zn 3411
275
PineCrkSeg03
Qty
Avg
Surface Soil (mg/kg)
Total Lead
9
2940
Total Zinc
9
579
Sediment (mg/kg)
Total Lead
22
198
Total Zinc
22
298
CC287 / CC288
Pb 174 49
Zn 2996 556
NMSegOl
Qty
Avg
Surface Water (pg/L)
Total Lead
6
403
Dissolved Zinc
6
6080
Surface Soil (mg/kg)
Total Lead
NA
NA
Total Zinc
NA
NA
Sediment (mg/kg)
Total Lead
NA
NA
Total Zinc
NA
NA
CCSeg02
Qty
Avg
Surface Soil (mg/kg)
Total Lead
8
776
Total Zinc
13
378
Sediment (mg/kg)
Total Lead
3
184
Total Zinc
3
213
CCSeg04
Qty
Avg
Surface Soil (mg/kg)
Total Lead
75
7010
Total Zinc
77
5370
Sediment (mg/kg)
Total Lead
7
7200
Total Zinc
7
6210
SF228
Pb 9.2
Zn 188
CCSeg05.
Qty
Avg
Surface Soil (mg/kg)
Total Lead
44
6260
Total Zinc
45
2140
Sediment (mg/kg)
Total Lead
9
11300
Total Zinc
9
43100
LCDRSeg04
Qty
Avg
Surface Soil (mg/kg)
Total Lead
62
2880
Total Zinc
59
3060
Sediment (mg/kg)
Total Lead
853
3230
Total Zinc
853
2300
LCDRSeg02
Qty
Avg
Surface Soil (mg/kg)
Total Lead
131
3640
Total Zinc
130
3620
Sediment (mg/kg)
Total Lead
611
3310
Total Zinc
611
2990
\
PineCrkSegOl
Qty
Avg
Surface Soil (mg/kg)
Total Lead
7
3280
Total Zinc
7
2390
Sediment (mg/kg)
Total Lead
52
1020
Total Zinc
52
1200
MidGradSegOl
Qty
Avg
Surface Soil (mg/kg)
Total Lead
264
2920
Total Zinc
237
1150
Sediment (mg/kg)
Total Lead
36
3120
Total Zinc
36
2560
UpperSFSegOl
Qty
Avg
Surface Soil (mg/kg)
Total Lead
35
11900
Total Zinc
20
5380
Sediment (mg/kg)
Total Lead
19
4060
Total Zinc
19
2970
Legend
River / Stream Sampling Locations
River / Stream
Leader line points to the
center of the river segment.
Number of
Samples in
River Segment
River Segment \ Expected Average
! \ Concentration
Leader line points to a
river / stream Sampling Location
Lake
N
LCDRSeg06
Qty
Avg
Surface Soil (mg/kg)
Total Lead
3
2810
Total Zinc
NA
NA
Sediment (mg/kg)
Total Lead
92
4050
Total Zinc
92
3160
^River/Stream Sampling Location
LC60 Cone Load
Total Pb 51.6 pg/L 1,510 #/d
Dissolved Zn 344 pg/L 3,736 #/d
2.5
10
9 Miles
Note: Average concentration data for river segments
taken from the Remedial Investigation Report, Sept., 2001
pg/L = micrograms per liter
mg/kg = milligrams per kilogram
Note: Estimated average concentrations and loads in surface
water at a river/stream sampling location from the Feasability
Study, Oct., 2001 and Probabilistic Analysis of Post-Remediation
Metal Loading (USEPA 2001f)
pg/L = micrograms per liter
#/d = pounds per day
Figure 5.2-2
Average Metal Concentrations
in Soil, Sediment and Surface Water
027-RI-CO-102Q
Coeur d'Alene Basin ROD
&EPA
REGION 10
Document Control: 4162500.07099.05.a
N:\envlmntr\maps\cdaexpected3.mxd
bookmark: 11x17 II
This map's projection is based on
Idaho State Plane West Zone,
NAD 1983.
Date of Plot: August 15, 2002
-------
¦ Dissolved zinc load
~ Dissolved zinc concentration
Concentration equal to
= 10x AWQC*
Concentration equal to
AWQC* (at hardness
of 50 mg/L CaC03) = 58 ug/L
The ambient water quality criterion
(AWQC) is proportional to the water
hardness. As a result, the AWQC varies
with location in the Basin. 50 mg/L is
a typical hardness value.
Note: Estimates based on analysis of available data from 1991 -1999
oEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 5.2-3
Estimated Average Values of Dissolved Zinc Loads and Concentrations (1991-1999 Data)
-------
7.4%
Adit Drainage
4.4%
Upland and Floodplain
Waste Rock
5.2%
Unimpounded Tailings
7%
Tailings in Active
Impoundments
5%
Tailings in Inactive
Impoundments
71%
Floodplain Sediments
Note: Percentages of dissolved zinc load were estimated by combining the estimated
volumes of source materials with the relative loading potentials of the source materials,
as described in USEPA 2001f, "Probabilistic Analysis of Post-Remediation Metal Loading"
SEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 5.2-4
Estimated Sources of Dissolved Zinc Load in the Upper Basin (not including the Bunker Hill Box)
-------
Woodland Park
Boundary of
Valley-fill Aquifer
EXPLANATION
I jaj I Average dissolved zinc load exiting
\c 1' I study area, pounds per day
Average dissolved zinc load entering
J study area, pounds per day
A Average gain in dissolved zinc load
in reach, pounds per day
River reach gaining water due to
the underlying aquifer discharging
ground water to the river
River reach losing water due to
the river discharging to the
underlying aquifer
Tailings pond
Reference: Barton 2000
0 2500
5000
C
Scale In Feet
NORTH
Doc. Control: 4162500.07099.05.a
SEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
EPA No. 2.9
Figure 5.2-5
Dissolved Zinc Loads in Canyon Creek at Woodland Park, September 17,18, and 19,1999
-------
Basin Non-Permitted
Discrete Load
135 lb/day
Basin Permitted
Discrete Load
13 lb/day
Box Non-Discrete
Load
1465 lb/day
Basin Non-Discrete
Load
1221 lb/day
Basin Total Load
1370 lb/day
Box Permitted
Discrete Load
85 lb/day
Box Total Load
1550 lb/day
Notes:
~ 1. Non-discrete loads include waste piles and nonpoint sources (mining wastes that were disposed directly into
~ ~ the receiving water in the past).
~ 2. Total dissolved zinc loads in Basin and Box equal to estimated average loads based on 1991 to 1999 data (USEPA 2001c).
~ ~ Loads from the Box are expected to decrease with time as a result of capping ofthe CIA, source removals in Smelterville
~ ~ Flats and the gulches (2.0 million cy), discontinuation of discharge of mine water on the CIA, and other actions. Monitoring
~ ~ will be conducted to evaluate the effectiveness of these actions.
~ 3. Permitted loads based on data provided by EPA Office of Water (USEPA 2000c)
~ 4. Basin non-permitted discrete loads from Feasibility Study (USEPA 2001c), Part 3, Appendix D, Table D-26)
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 5.2-6
Discrete and Non-Discrete Sources of Dissolved Zinc
Load in the South Fork
-------
¦ Total lead load
~ Total lead concentration
o>
=3
o
2
-4—•
c
0)
o
c
o
o
>»
<0
¦a
a>
a.
T3
C
3
O
a.
1600
1400
1200
1000
800
600
400
200
0
1510
I
1
1
708
¦
1
369
1
1
174
1
1
156
8.2 9.2
4^~
92
13J-]
130
¦_32
12 4.6
[56
99
fc
L
B 52
[3.9
,
-------
Franklin D. Rooaevelt Lake
(Columbia River)
2
D)
E,
c
o
c
-------
c
8
c
o
O
TO
TO
<13
1400
1200 ¦
1000
o>
"Sj
E,
c
o
.2 800 -
600
400 "
200
Franklin D. Roosevelt Lake
(Columbia River)
*
¦V
IDAHO
Post Falls
Spokana
il
MI-..II1
Id.
U.S.G.S. Sediment Sampling Locations from Lake Roosevelt, Washington, to Post Falls, Idaho
v>EPA
REGION 10
Doc. Control: 4162500.07099.05.a
027-RI-CO-102Q
EPA No. 2.9
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Figure 5.2-9
Lead Concentrations in Spokane River Sediments
-------
Franklin D. Roosevelt Like
(Columblt River)
IDAHO
Post Falls
COMVdAWW
Spokane1;
WASHINGTON
0
U.S.G.S. Sediment Sampling Locations from Lake Roosevelt, Washington, to Post Falls, Idaho
SEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc Control: 4162500.07099.05.a
EPA No. 2.9
Figure 5.2-10
Zinc Concentrations in Spokane River Sediments
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-23
Table 5.2-1
Summary of Lead Concentrations in the Upper and Lower Basin
Minimum.
Miiximiim.
ArillinuMic
(lOOIlHMl'ic
Medium
No. (>l'S;ini|)k's
£
£
Mciin.
Mciin. m«i/kii
Low oi
ISiisin
^ aid Soil
l(>()
15
'5n
4S~
1 lu
1 louse 1 )usi
'1
4<>
VI4H
5i:
'U|
I PIH'I
ISiisin
Yard Soil
834
22
20,218
821
460
House Dust
268
23
29,725
997
659
Notes:
House dust lead concentrations were measured from vacuum bag samples
Source: Human Health Risk Assessment (IDHW 2001a)
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-24
Table 5.2-2
Summary of Analytical Results for Metals in Soil
No. of
Perccn(;i*ie of
ISiick^i'oiind
No. of Di'lcdions
M ;i\iniii in
Doled ions
Siiniplcs
( oncen-
l'.\m'dinii
No. of
No. of
(oiKTiili'iilion
PRC
I'AtX'cdinii
I-Acc'c'dinii
li'iilion
ISiick^i'oinul
( homiciil
Doled ions
Siimplos
diiii/k")
(niii/kji)
PRC;
PRC;
(niii/kii)1'
CoiK'onli'iilions
Antimony
2,966
4,029
623
30
313
7.8
5.8
1,239
Arsenic3
4,186
4,208
3,610
0.38
4,186
99
22
1,346
Cadmium
3,939
4,208
194
37
184
4.4
2.86
2,290
Iron
3,980
3,980
256,000
22,000
1,527
38
65,000
369
Lead
4,208
4,208
67,100
400
1,336
32
175
3,065
Manganese
4,002
4,002
26,400
3,100
500
12
3,600
450
Zinc
4,208
4,208
25,800
22,000
3
0.07
280
2,806
a Carcinogen; PRG are protective of cancer health effects
b 90th percentile from Gott and Cathrall (1980).
Notes:
COPC - chemical of potential concern
NA - not available
PRG - preliminary remediation goal (from tables in EPA Web site at http://www.epa.gov/region09/waste/sfund/prg)
SV - screening value (0.1 times EPA PRGs for noncarcinogens and same as PRGs for carcinogens)
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-25
Table 5.2-3
Summary of Analytical Results for Metals in House Dust
M;i\iiiin in
Poroonl
No. <»r
No. of
(oneonlnilinn
Soil piu;
No. of Dcli'clions
Doled ions
( homiciil
Doled ions
S;iiii|)k's
(mg/kgj
ijng/kiy
K.xm'ri.ing PRC;
l-'.ym'riiiig PU(.
Antimony
160
160
318
30
29
18
Arsenic3
160
160
635
0.38
160
100
Cadmium
159
160
375
37
5
3.1
Iron
160
160
60,800
22,000
115
72
Lead
160
160
59,500
400
134
84
Manganese
160
160
5,460
3,100
3
1.9
Zinc
160
160
57,500
22,000
2
1.3
a Carcinogen; the PRG for arsenic is protective of cancer health effects at a target risk of 1 in 1 million.
b Samples collected from vacuum bags and floor mats.
Notes:
There are no background values available for house dust.
COPC - chemical of potential concern
NA - not available
PRG - preliminary remediation goal for residential soil (from tables in EPA Web site at: http://www.epa.gov/region09/waste/sfund/prg)
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-26
Table 5.2-4
Summary of Analytical Results for Metals in Drinking Water
Miiximiini
No. of
Pereenliiiie
No. or
Coneen-
Deleelions
of Siimples
Deleelions
No. of
No. of
li'iilion
PRC
l'.\eeeilin;i
I'.xeeedinti
MCI.
H\eee(lin*i
( hemie;il
Deled ions
Siimples
(pji/l.)
(fiii/l.)
PRC
PRC
(pii/l.)
MCI.
l-'ii'sl Di'iiw Siimples
Arsenic3
45
102
7.6
0.045
45
44
10
0
Cadmium
45
102
33.6
18
1
1.0
5
5
Lead
101
102
78.5
4
36
35
15
11
Flushed l.inc Samples
-VlijClUC
45
loo
y.2
0.045
45
45
10
0
Lead
83
100
9.5
4
2
2.0
15
0
a Carcinogen; PRGs are protective of cancer health effects
Notes:
COPC - chemical of potential concern
MCL - Maximum Contaminant Level
PRG - preliminary remediation goal (from tables in EPA Web site at http://www.epa.gov/region09/waste/sfund/prg)
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-27
Table 5.2-5
Summary of Estimated Basin Ecological Source Quantities
Source T\nc
I nils
(JiiiinliM
I |)|KT Biisill
Floodplain Sediments3
cy
7,100,000
Tailings'3
cy
11,000,000
Waste Rock0
cy
11,700,000
Adit Drainaged
#Zn/d
101
Lowci' ISiisiu
River bed Sediments, including the Harrison Delta6
cy
20,600,000
Bank Wedgese
cy
1,780,000
Wetland Sediments6
cy
5,900,000
Lateral Lake Sediments6
cy
5,900,000
Floodplain Sediments6
cy
10,200,000
Cataldo/Mission Flats Dredge Spoils
cy
13,600,000
Cocur (I'Alcnc l.iikc
Lake Bottom Sediments
cy
44,000,000 to
50,000,000
Spokiinc Ki\cr'
Shoreline and River bed Sediments
cy
260,000
a Impacted sediment present in the current and historic 100-year floodplain. Total volume does not include either
less impacted, generally deeper and more dispersed sediments that are potential source of zinc loading or impacted
materials within fills or embankments (e.g., 1-90 and UPRR rights-of-way); these additional sediment volumes may
be as high as approximately 20,000,000 cy.
b Tailings volumes include unimpounded tailings and impounded tailings in both inactive and active facilities.
0 Waste rock volumes include waste rock in floodplains and uplands, as well as waste rock at active facilities.
d Data used to calculate average zinc loading are available for only 53 of 114 discharging adits in the upper basin.
Although data are available for the largest loaders, the cumulative average zinc load from all discharging adits may
exceed the amount shown in this table.
e Volumes estimates for all impacted media in the lower basin, CSM Unit 3, are based on lead concentrations
exceeding 1,000 mg/kg. Additional volumes of impacted sediments that are potential sources of zinc loading are
not included in these estimates.
f Contaminated sediments upstream of Upriver Dam. Additional contaminated sediments are present downstream of
Upriver Dam, but have not been quantified.
Notes:
This is a condensed summary with approximate quantities—for a detailed accounting of sources and remedial
actions see the FS Part 3, Sections 5 and 6 and appendices as referenced therein (USEPA 2001c). Quantities of
source materials within the BHSS are not included in this table.
cy - cubic yards
#Zn/d - pounds of zinc per day
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-28
Table 5.2-6
Estimated Average (Expected) Values of Metals Concentrations in Surface Water in the Basin, 1991-1999 Data
l)issol\od ( ;i«l mill in
Tulill I.OiK
l)issol\ed Xilie
Siiinpliii^ l.nciilinn
l-'.sliniiilod
r.\|)oc(cd
\ illllC
i" HSi/1-
(V
Number of
Siimplos
I'.sliniiilcd
l.\|KTk'd
Value
i" MSi/l-
(V
Number ol'
Samples
r.slimnled
l.\|K'CU'd
Value
in .
(V
Number ol'
Samples
South l-'oi'k iiiul Trihiiliirics
SF220 (below Mullan)
0.7
0.55
41
11.1
0.59
41
130
0.68
41
SF228 (below Trowbridge
Gulch)
1.1
0.46
46
9.2
0.90
46
188
0.74
47
SF239 (Silverton)
7.2
0.70
56
43
1.13
56
1,080
0.74
56
SF249 (Osburn)
7.45
0.48
37
27
0.66
37
1,110
0.52
37
SF259 (SF at above Big Creek)
8.1
0.45
38
25
0.71
38
1,200
0.48
38
SF268 (near Elizabeth Park)
6.8
0.61
67
32
1.58
67
976
0.59
67
SF270 (Smelterville)
11.3
0.52
45
43
1.26
45
1,674
0.55
45
SF271 (Pinehurst)
9.1
0.63
108
56
1.34
69
1,430
0.63
111
( iiinnn ( ivck
cc:
NA
NA
NA
3.2
1.5"
Jo
2o.2
(143
i(l
CC276
0.7
0.23
41
11.9
1.53
41
122
1.41
41
CC278
2.5
0.67
38
13.3
0.4
38
378
0.67
38
CC291
3.9
0.51
35
20.4
0.35
35
650
0.65
35
CC282
7.1
0.55
23
114
1.8
23
1,100
0.52
23
CC284
8.4
0.51
42
72.6
1.46
42
1,370
0.56
42
CC285
10.8
0.85
38
213
2.45
39
1,460
0.8
38
CC287 and CC288
21.9
0.74
92
174
1.99
93
2,996
0.71
93
Niiiomik' ( ivck
NM291
1.1
0.48
32
I.Jo
32
318
1.5o
32
NM293
17.3
0.76
24
24.6
0.69
24
4,670
2.16
23
NM295
15.8
0.68
18
23.2
0.50
18
3,000
0.61
18
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-29
Table 5.2-6 (Continued)
Estimated Average (Expected) Values of Metals Concentrations in Surface Water in the Basin, 1991-1999 Data
l)issol\i'(l ( ;i«l mill in
l olill I.OiK
l)issol\ed Zinc
l-'.sliniiilod
I.N(ini;iU'd
r.slimnled
r.\|)oc(c(l
\ illllC
Number of
l.\|K'Ck'd
Value
Number ol°
r.xpecled
Value
Number of
Siiinpliii^ Locution
i" HSi/1-
(V
Siimplos
i" MSi/l-
(V
Samples
in .
(V
Samples
NM296
33.2
0.55
54
587
7.2
54
6,070
0.53
54
NM298
42.7
0.66
50
234
0.88
50
7,140
0.69
50
NM303
27.7
0.42
42
99.4
0.43
42
4,590
0.8
42
NVP05
21 i
0 48
96
92 1
0.80
98
\411
0 47
96
Pi lie ( ivck
PC307
2.6
0.21
39
4.5
1.19
39
974
0.237
39
PC308
11.7
0.27
33
9.6
0.54
33
4,430
0.269
33
PC '05
0 54
: (.s
i:
4 <>
1 '
'8
1i:**
0 45**
'8
IJi» ( reck
BC260 (mouth of Big Creek)
1 (max.
detected)*
NA
NA
28 (max.
detected)*
NA
NA
6.9 (max.
detected)*
NA
NA
Moon (reck
\1('2(>2 (iikm1111 of \Kh>ii ( reek)
0 (iS
0 V,
58
1
/
i:
5"
i:i
0
58
Miiin Siom
LC50 (Cataldo)
3.2
1.3
101
20.9
1.43
44
354
0.61
102
LC55 (Rose Lake)
2.3
1.02
71
35.1
1.34
35
263
0.88
12
T.C60 rHarrisonN)
1 9
n "37
91
51 6
1 08
^2
^44
0 48
Q1
Spokiino Ui\i*r
SR50 (Post Falls, ID)
NA
NA
9
2.12
0.87
9
57.6
0.48
10
SR55 (near Otis Orchard, WA)
NA
NA
7
2.31
0.77
7
50.7
0.52
7
SR60 (Greenacres)
NA
NA
7
2.41
0.92
7
51.2
0.47
7
SR65 (near Trentwood)
NA
NA
7
2.41
0.97
7
50.7
0.61
7
SR70 (Spokane)
NA
NA
7
2.21
1.13
7
53.1
1.22
7
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-30
Table 5.2-6 (Continued)
Estimated Average (Expected) Values of Metals Concentrations in Surface Water in the Basin, 1991-1999 Data
Siiinpliii^ l.nciilinn
1)
l-'.sliniiilod
r.\|K'CK'd
Value
i" H!i/I
ssnltcri Ciid
(V
ilium
Number of
Siimplos
I'.sliniiilcd
l.\|K'Ck'(l
Value
i" MSi/l-
l olill I.OiK
(V
Number of
Samples
r.slimaled
l.\|K'CU'd
\ illlK'
in .
l)issol\cd /
(A
IIC
Numhor ol'
Siimpk's
SR75 (Spokane)
NA
NA
10
2.72
1.02
9
50.1
0.58
9
SR85 (Long Lake)
NA
NA
13
1.45
0.50
8
27.3
1.74
13
Notes:
* Data-based value from USEPA (2001b), Part 2, Big Creek
** Without two outliers
CV - coefficient of variation
NA - not applicable
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-31
Table 5.2-7
Estimated Average (Expected) Values of Metals Loads in Surface Water in the Basin, 1991-1999 Data
Dissolved C ;i(lniiiiin
Tohil l.e:id
Dissolved Zinc
S;illl|>lill!! l.oi;ilion
l!slim;iled
K\peeled \ ;ilill-
ill pollllds/d;i>
( V
Number of
Samples
l!slim;iled
l".\peiled Y;ilue
ill pounds/d;i>
( V
Number of
Samples
l!slim;iled
K\peeled Value
ill pouilds/d;i>
C V
Number ol'
S;i mples
Sou 111 lork ;iihI Tribukiries
Sl'220 (below Mullan)
0.22
1.11
41
5
1.65
41
35
0.67
41
SF228 (below Trowbridge
Gulch)
0.50
1.05
46
8.2
3.9
46
89.4
1.23
47
SF239 (Silverton)
7.8
0.88
56
140
4.9
56
1,110
0.83
56
SF249 (Osburn)
5.9
0.75
37
39.4
2.25
37
877
0.77
37
SF259 (SF above Big
Creek)
8.3
0.88
38
49.5
2.64
38
1,200
0.85
38
SF268 (near Elizabeth Park)
8.9
0.68
67
130
5.89
67
1,280
0.691
67
SF270 (Smelterville)
16.4
0.90
45
116
3.43
45
2,100
0.64
45
SF27I (Pinehursl)
20.9
0.87
108
369
5.53
69
2.920
0.61
1 1 1
(;in\on (reek
CC276
0.1
0.73
41
1.2
2.16
41
8.2
1.29
41
CC278
0.2
0.58
38
1.5
0.83
38
34
1.06
38
CC291
0.5
0.67
35
3
1.04
35
75
0.57
35
CC282
1.5
0.71
23
40.1
3.46
23
239
0.77
23
CC284
1.4
0.81
42
13.4
1.99
42
227
0.7
42
CC285
2.9
1.1
39
98.1
5.08
38
400
0.82
38
CC287 and 288 combined
ro
1.20
92
48.6
3.14
93
556
0.67
93
Ninemile Creek
NM291
0.03
1.34
32
0.3
4.2
32
33.1
0.84
32
NM293
0.5
1.06
24
0.8
1.37
24
99.6
11.86
23
NM295
0.6
0.91
18
1.3
1.3
18
125
1.74
18
NM296
1.3
0.7
54
3.7
0.69
54
251
0.88
54
NM298
1.3
0.77
50
8.6
1.41
50
210
0.72
50
NM303
1.3
0.74
42
5.3
1.07
42
203
0.79
42
NM305
1.6
0.86
96
13.1
2.63
98
275.5
0.92
96
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-32
Table 5.2-7 (Continued)
Estimated Average (Expected) Values of Metals Loads in Surface Water in the Basin, 1991-1999 Data
Dissolved C ;i(lniiiiin
Tol;il l.e:id
Dissolved Zinc
S;illl|>lill!! l.ui;ili(iii
l!siim;iled
K\peeled \ ;ilill-
ill pouilds/d;i>
( V
Number of
Samples
l!slim;iled
l".\peiled Y;ilue
ill pollllds/d;i>
( V
Number of
Samples
l!slim;iled
ll\pecled Value
ill pouilds/d;i\
C V
Number of
Samples
Pi ill- (reek
PC307
0.07
1.18
39
0.2
7.51
39
26.1
1.21
39
PC308
0.05
0.92
33
0.04
1.36
33
18.5
0.99
33
PC305
5.4
96.4
12
12.3
19.9
38
90.2**
2.93**
36
IJi» (reek
BC260 (nioiilh of 1 Jig
Check)
Not delected to
0.03*
NA
NA
l.7lo9l.1
(measured)*
NA
0.9 lo 4.7
(measured)*
NA
NA
Mhoii Creek
MC262 (mouth of Moon
Creek)
0.05
2.24
58
0.42
6.00
57
9.9
3.06
58
Miiin Sli'iii
LC50 (Cataldo)
26.9
1.32
101
708
6.78
44
3,220
0.73
102
LC55 (Rose Lake)
28.1
1.34
71
1,750
6.89
35
4,260
0.69
12
LC60 (Harrison)
29
1.39
91
1,510
4.11
32
3,736***
1.02
91
S|)uk;iiU' Rixer
SR50 (Post Falls, ID)
NA
NA
9
156
3.86
9
3,640
3.67
10
SR55 (near Otis Orchard,
WA)
NA
NA
7
247
5.68
7
5,000
4.65
7
SR60 (Greenacres)
NA
NA
7
380
9.19
7
5,560
5.06
7
SR65 (near Lrentwood)
NA
NA
7
434
10.4
7
7,030
6.7
7
SR70 (Spokane)
NA
NA
7
278
6.45
7
7,110
7.24
7
SR75 (Spokane)
NA
NA
10
285
3.81
9
4,310
2.41
9
SR85 (Long Lake)
NA
NA
13
110
0.99
8
2,210
3.12
13
* Data-based value from USEPA (2001k), Part 2 Big Creek Notes:
** Without two outliers CV - coefficient of variation
*** Updated value; see Section C.4.3 of USEPA 2001f "Probabilistic Analysis of Post-Remediation Metal Loading." TMDL - total maximum daily load
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-33
Table 5.2-8
Summary of Floodplain Areas Affected by Lead, by Wetland Unit
Wclliiml I nil
Wclhiml AiVii. Acres
l.iilci'iil l.iiko Arc.i. iicivs
Kipiiriiin Arciis. Acivn
ToCil
l.c;i(l>530'
niii/kii
Tnliil
l.cii(l>530'
mii/kii
Tnliil
l.cii(l>530;l
nifi/kii
Harrison Slough
41
40
679
669
34
30
Harrison Marsh
59
58
157
157
35
34
Thompson Marsh
60
59
125
122
21
16
Thompson Lake
303
299
260
256
32
25
Anderson Lake
47
44
527
505
39
36
Bare Marsh
165
160
0
0
17
17
Blue Lake
57
53
320
316
37
37
Black Lake
40
17
379
368
64
272
Swan Lake
367
362
475
471
210
205
Cave Lake
196
190
753
746
123
116
Medicine Lake
210
198
242
230
85
83
Blessing Slough
178
168
0
0
76
76
Moffit Slough
114
114
146
146
66
66
Campbell Marsh
174
173
107
106
135
129
Hidden Marsh
436
418
204
199
44
38
Killarney Lake
155
152
491
482
48
42
Strobl Marsh
275
269
0
0
79
77
Lane Marsh
430
425
0
0
82
80
Black Rock Slough
235
232
204
201
169
166
Bull Run
16
16
114
106
8
8
Rose Lake
436
409
362
357
142
135
Porter Slough
135
126
0
0
0
0
Orling Slough
58
49
54
52
16
15
Canyon Marsh
101
50
25
25
22
19
Cataldo Slough
151
114
325
314
246
228
Mission Slough
284
280
151
150
115
108
Whiteman Slough
177
171
0
0
43
32
27 units
4,901
4,646
6,100
5,979
1,986
1,844
Source: U.S. Fish and Wildlife Service, Upper Columbia Fish and Wildlife Office (July 2001)
a - 530 mg/kg represents the Lowest Observable Effect Level (LOEL) for waterfowl (Beyer et al. 2000)
References:
Kern, J.W. 1999. Statistical Model for the Spatial Distribution of Lead Concentration in Surficial Sediments in the Lower Coeur
d'Alene River Floodplain with Estimates of Contaminated Soils and Sediments. Draft (August 26, 1999). Prepared for the U.S.
Fish and Wildlife Service, Spokane, Washington.
Beyer, W. N., D. J. Audet, G. H. Heinz, D. J. Hoffman, and D. Ray. 2000. "Relation of Waterfowl Poisoning to Sediment Lead
Concentrations in the Coeur d'Alene River Basin". Ecotox. 9: 207 - 218.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 5.0
Page 5-34
Table 5.2-9
Metals Loads and Retention in Coeur d'Alene Lake
I'm
l')95
i«>«>7
1')')')
Piii'iimolcr
(low (lisdiiii'uc)
(;i\er;iiie disdiiirtii'l
(liiiili (lischiMiio)
(120" n of ;i\or.iiie disdi;ii'^c)
Anniiiil moiin disdi;iruc ids)
2.To
(i. 'DO
|o. ^00
7.530
Zinc
Total Inflow (kg)
460,000
880,000
1,400,000
1,570,000
Total Outflow (kg)
260,000
580,000
860,000
1,080,000
Percent Retained
43
35
41
31
l.ciid
Total Inflow (kg)
88,000
470,000
1,300,000
590,000
Total Outflow (kg)
16,000
37,000
100,000
51,300
Percent Retained
82
92
92
91
( iidmium
Total Inflow (kg)
3,800
7,200
11,000
10,400
Total Outflow (kg)
1,700
3,600
5,800
4,940
Percent Retained
56
51
47
53
Note: Refers to whole-water recoverable metals loads
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-1
6.0 CURRENT AND POTENTIAL FUTURE LAND AND RESOURCE USES
This section describes current and anticipated future land, groundwater, and surface water uses.
6.1 CURRENT LAND USE
The Basin includes areas within Shoshone, Kootenai, and Benewah counties in Idaho and
Spokane and Stevens counties in Washington. The majority of the population of the Basin lives
in the cities of Spokane, Coeur d'Alene, and Post Falls, which have populations exceeding
177,000, 24,000, and 7,000 people, respectively. All other communities in the Basin have
populations less than 2,000. In Kootenai and Shoshone counties, over 38 percent of the total
population is in rural areas.
Land use includes residential, commercial, light industrial, agriculture, mining, and recreation.
The 1-90 freeway generally parallels the South Fork of the Coeur d'Alene River from Cataldo
east to the Idaho/Montana border. The UPRR right-of-way parallels the entire length of the river
as well as a portion of the southern lake shore. This inactive rail line is currently being
addressed and converted to a recreational trail.
Much of the Basin is rural, undeveloped land, a large part of which is federally or state-managed.
These undeveloped lands and the numerous streams in the Basin provide a variety of recreation
opportunities. Undeveloped areas include upland forest habitats and lowland floodplains with
riverine, riparian, wetland, and lake habitats. The quality of these habitats and their ability to
support natural populations of flora and fauna has been impacted to varying degrees by historic
mining activity in the Basin.
The Basin is the ancestral home of the Coeur d'Alene and Spokane Tribes. Coeur d'Alene
reservation lands are present in the Lower Basin, and Spokane reservation lands are adjacent to
the lower Spokane River. Historically, the Coeur d'Alene and several other tribes, including the
Spokanes, relied solely on resources of the Basin for sustenance. Subsistence lifestyles are a
current land use and are a potential future land use in the contaminated areas of the Lower Basin;
however, this lifestyle cannot currently be safely practiced in these areas due to the extent of this
contamination. The Coeur d'Alene Tribe currently advises its members not to use these
contaminated resources for subsistence.
Risks to persons, including Spokane tribal members, and others who may practice a subsistence
lifestyle in the lower Spokane River now or in the future have not been quantified. EPA and the
Spokane Tribe are cooperating in planning additional testing and studies that will be
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-2
implemented to evaluate the potential exposures to subsistence users. The results of those tests
and studies will determine appropriate future response actions to be taken, if any.
When compared to conditions statewide, a number of indicators show that socio-economic
conditions in the Basin upstream of Coeur d'Alene Lake are depressed. These indicators
include:
• Higher unemployment
• Higher percentages of persons living below the poverty level
• Lower rates of high school and college graduation
• Higher per capita welfare payments
• Generally decreasing tax base
The socio-economic status of families has been noted to be a significant factor affecting
children's blood lead levels in numerous studies (Pirkle et al. 1998, Brody et al. 1994, Clark
et al. 1985, Bornschein et al. 1985). In the Basin, young children often have limited places to
play, and when not at their home or at school are often found on commercial properties or other
common areas.
6.2 ANTICIPATED FUTURE LAND USES
It is anticipated that future land use will be similar to current or reasonably foreseeable future
land use. Although population levels in the Basin have declined in recent years, the City of
Coeur d'Alene has experienced substantial population growth, and it is possible that population
growth could expand into the Basin. It is not anticipated that areas of the Lower Basin
floodplains that are currently undeveloped or used for agriculture could be developed for
residential use due to regulatory restrictions on residential development in the floodplain.
Increased recreational use of beaches may occur as a result of several factors: 1) increasing
tourism in the Basin; 2) easier access due to the conversion of the UPRR right-of-way, which
parallels the river, into a trail; and 3) increased population.
6.3 SURFACE WATER AND GROUNDWATER USES
The State of Idaho has identified designated beneficial uses for the surface water of the Idaho
portion of the Basin. All waters are designated by statute for agricultural and industrial water
supply, wildlife habitat, and aesthetics. In addition, all waters in the Basin are designated for
cold water aquatic life and secondary contact recreation, although the cold water aquatic life use
is not attained or only partially attained in some waters. Less-impacted waters may be
designated for salmonid spawning, primary contact recreation, and drinking water supply;
however, these uses are limited in some parts of the area of mining impacts. The designated uses
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-3
are shown in Table 6.3-1. The lateral lakes in the Lower Basin, which are not listed in Table 6.3-
1, are all designated for agricultural and industrial water supply, wildlife habitat, aesthetics, cold
water aquatic life, and primary or secondary contact recreation.
The use designations do not reflect pre-mining use and condition of the stream. The designated
uses generally reflect current surface water uses, with some exceptions where the designated uses
are not currently attained. For example, Ninemile Creek, from and including East Fork Ninemile
Creek to its mouth, is designated for cold water aquatic life and salmonid spawning. These uses
are not currently attained in Ninemile Creek downstream of mining impacts. Similarly, cold
water aquatic life is not attained in Canyon Creek downstream of mining impacts. The
designated uses and areas of current non-attainment or partial attainment are presented in
In addition to its designations for cold water aquatic life, drinking water supply, primary contact
recreation, and salmonid spawning, Coeur d'Alene Lake is designated as a special resource
water. Special resource waters are those specific segments or bodies of water which are
recognized as needing intensive protection to preserve outstanding or unique characteristics or
maintain current beneficial use (IDAPA 58.01,02§003). The lake is important to the economy of
the region. Its aesthetic qualities and the recreation opportunities it affords enhance the area as a
place to live and promote tourism.
The flowing water sections of the Spokane River in Washington are classified as Class A
(excellent) (WAC 173-201 A). The Spokane River from Long Lake Dam to Ninemile Bridge is
classified as Lake Class. The characteristic uses of these classes include, but are not be limited
to:
Water supply (domestic, industrial, agricultural)
Stock watering
Fish and shellfish migration, rearing, spawning, and harvesting
Wildlife habitat
Recreation (primary contact recreation, sport fishing, boating, and aesthetic
enjoyment)
Table 6.3-1.
Commerce and navigation
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-4
East of Coeur d'Alene Lake, groundwater and surface water are used as drinking water sources.
Within the Upper Basin and Lower Basin, about 57 percent of residences obtain water from a
public source and 43 percent obtain water from a private source. Table 6.3-2 describes the
public drinking water systems in these areas, and Table 6.3-3 shows the estimated number of
residences using private drinking water sources within the human health alternatives study area.
Although groundwater data are limited, future use of groundwater from shallow, unconfined
aquifers within the area of mining impacts in the Upper Basin and Lower Basin as drinking water
may be limited by concentrations of cadmium, lead, and zinc that exceed maximum contaminant
levels (MCLs) until cleanup is implemented. Although the Selected Remedy is expected to
result in improvements to groundwater quality, it is not intended to satisfy the groundwater
protection strategy for returning beneficial uses of groundwater as outlined in the NCP.
In addition to the beneficial use of groundwater as a drinking water supply, groundwater may
influence surface water quality. In some parts of the Basin, surface water is in communication
with groundwater. The interaction between surface water and groundwater is a route for
migration of metals between these two media. The South Fork and its tributaries are important
areas of interaction between surface water and groundwater. As described in Section 5.2.2, a
significant load of metals is conveyed from groundwater to surface water is this area. This
loading affects the ability to achieve surface water quality standards in the Basin. Because the
groundwater protection strategy is also intended to protect critical environmental systems, such
as fisheries in the Upper Basin, loading of metals from groundwater to surface water will be
evaluated as the Selected Remedy is implemented.
The Spokane Valley-Rathdrum Prairie Aquifer, a sole source aquifer, underlies an area of about
327 square miles, including 125 square miles in Washington and 202 square miles in Idaho.
Groundwater from the aquifer provides most of the water used in Spokane County for domestic,
municipal, and industrial (other than aluminum production) purposes, and a large part of the
irrigation supply. The total amount of groundwater pumped from the Spokane Valley portion of
the aquifer in 1977 was about 164,000 acre-feet, of which about 70 percent was withdrawn for
municipal and domestic use (Molenaar 1988). The Spokane Valley-Rathdrum Prairie Aquifer in
western Idaho and eastern Washington receives an estimated 30 percent of its water from Coeur
d'Alene Lake and the upper Spokane River (Wyman 1993).
On the Spokane Reservation, large terrace deposits of glacial outwash serve as aquifers near the
Spokane River.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-5
Table 6.3-1
Surface Water Designated Beneficial Uses in Idaho
\\ iiloi-s
\(|iiiilic Life
KociViilion
Oilier
South Fork Coeur d'Alene River - Canyon Creek to mouth
COLD
SCR
Pine Creek - East Fork Pine Creek to mouth
COLD; SS
SCR
Pine Creek - source to East Fork Pine Creek
COLD; SS
PCR
DWS
East Fork Pine Creek - source to mouth3
Government Gulch - source to mouth
COLD; SS
SCR
Big Creek - source to mining impact area
COLD; SS
PCR
DWS
Big Creek - mining impact area to mouth
COLD; SS
SCR
Shields Gulch - source to mining impact area
COLD; SS
PCR
DWS
Shields Gulch - mining impact area to mouth
SCR
Lake Creek - source to mining impact area
COLD; SS
PCR
DWS
Lake Creek - mining impact area to mouth
COLD; SS
SCR
Placer Creek - source to mouth3
South Fork Coeur d'Alene River - from and including
Daisy Gulch to Canyon Creek
COLD
SCR
Willow Creek - source to mouth3
South Fork Coeur d'Alene River - source to Daisy Gulch
COLD; SS
PCR
DWS
Canyon Creek - from and including Gorge Gulch to mouth
COLD
SCR
Canyon Creek - source to Gorge Gulch
COLD; SS
PCR
DWS
Ninemile Creek - from and including East Fork Ninemile
Creek to mouth
COLD; SS
SCR
Ninemile Creek - source to East Fork Ninemile Creek
COLD; SS
PCR
DWS
Moon Creek - source to mouth3
West Fork Moon Creek - source to mouth3
Bear Creek - source to mouth
COLD; SS
PCR
DWS
Coeur d'Alene River - Latour Creek to mouth
COLD
PCR
Coeur d'Alene Lake
COLD; SS
PCR
DWS
SRW
Spokane River - Coeur d'Alene Lake to Post Falls Dam
COLD; SS
PCR
DWS
Spokane River - Post Falls Dam to Washington/Idaho
border
COLD; SS
PCR
DWS
Source of designated uses: IDAPA 58.01.02, Section 110
a These waters, although undesignated, are protected for cold water aquatic life and primary or secondary contact
recreation (IDAPA 58.01.02, Section 101-Undesignated Uses)
Notes:
All waters are designated for agricultural and industrial water supply, wildlife habitat, and aesthetics.
COLD - Cold water aquatic life
DWS - Drinking water supply
PCR - Primary contact recreation
SCR - Secondary contact recreation
SRW - Special resource water
SS - Salmonid spawning
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-6
Table 6.3-2
Coeur d'Alene River Basin East of Coeur d'Alene Lake Public Drinking Water Systems
Wilier
ol' Sjsicm
Sou rce
Population
('onni'Clions
( oin men Is
Community public water
Wells
4,490
1,875
system
Surface
water
7,013
3,446
Central Shoshone Water District
(population = 4,052, connections = 2,293)
is temporarily using surface water while
well undergoes corrosivity evaluation.
Unknown
574
226
Non-community
Wells
385
120
transient public water
Unknown
500
1
system
Non-transient, non-
Wells
445
2
community public water
Surface
490
13
system
water
Unknown
170
2
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 6.0
Page 6-7
Table 6.3-3
Estimated Number of Residences with Private, Unregulated Drinking Water Sources
r.siim;iied
Number ul'
Number ol'
A\ ;iil;ibilil\ of
Residences
l'ri\ ;ile.
Sllihible
Area ill'
Number ul"
it hill \\ ;iler
I iiiv^uhiled
Allern;ili\e
liiM'sli^iiliun
Residences'1
Disiriil
Si nines1'
Neiiresi Wider Disiriil
A(|uiler
I |>|KT li;isin
Upper Basin
4,633
3,417
1,216
East Shoshone County, Central
Shoshone County, Kingston, and
Pinehurst Water Districts
None to medium
l.m\er li;isin
Cataldo
1,642
842
400
Cataldo Water District
Medium
Harrison
400
Harrison Water District
High
aBased on site reconnaissance and demographic data from the human health risk assessment (IDHW 2001a).
bAssumes 100 percent of residences outside water district service boundaries have private, unregulated sources.
cOsburn has a moratorium on new well construction.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-1
7.0 SUMMARY OF RISKS
This section provides a summary of the pertinent information from the human health and
ecological risk assessments, focusing on the chemicals of concern (COCs) and other pertinent
issues that are the basis for the response actions at the site. COCs are defined as "those
chemicals of potential concern (COPCs) and media/exposure points that trigger the need for
cleanup (the risk drivers)" (USEPA 1998c). This section does not provide a complete summary
of the entire baseline risk assessment or other screening assessments conducted for the site but
focuses on the information that is driving the need for the specific remedial actions described in
this ROD.
7.1 SUMMARY OF HUMAN HEALTH RISK ASSESSMENTS
This section of the ROD summarizes the results of the baseline HHRA completed for the
Harrison to Mullan portion of the site (CSM Units 1, 2, and 3) (IDHW 2001a). Also
summarized are the results of two screening level risk assessments completed for Coeur d'Alene
Lake (CSM Unit 4) and the Spokane River, Washington State (CSM Unit 5) (Appendix B of
IDHW 2001a and USEPA 2000d). Unlike the baseline risk assessment, these screening level
risk assessments did not estimate risks; rather, site-specific "safe" levels of COPCs were
calculated and site concentrations were compared to the calculated levels. Locations within
CSM Units 4 and 5 with chemicals at concentrations above the specified levels were further
evaluated and are the subject, in some cases, of remedial action.
Typically, a baseline risk assessment estimates site risks if no action was taken. It provides the
basis for taking action and identifies the contaminants and exposure pathways that need to be
addressed by the remedial action. However, current conditions in the Basin are reflective of
ongoing actions taken to reduce lead exposure. These efforts include the Lead Health
Intervention Program (LHIP), which includes annual blood lead screening conducted by the
PHD, and high-risk removal actions completed by EPA since 1997.
The lead section of the HHRA was prepared in accordance with EPA national guidance applying
the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK). The national
guidance recommends using the IEUBK Model for "setting site-specific residential risk-based
preliminary remediation goals (PRGs) at CERCLA sites" and describes the model as the "best
tool currently available for predicting the potential blood lead levels of children exposed to lead
in the environment" (USEPA 1998c). The HHRA also has been peer-reviewed by EPA
Technical Review Workgroup for Lead (USEPA Technical Review Workgroup for Lead 2000).
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-2
For the HHRA, the IEUBK was used in two ways: (1) using the EPA recommended default
parameters and site-specific soil and house dust concentrations and (2) using site-specific
parameters derived from conditions observed within the Bunker Hill Box. The default approach
is representative of conditions assuming no action has occurred. The site-specific analysis
reflects local conditions including ongoing actions taken to reduce childhood lead exposure. The
site-specific model (hereafter referred to as the Box model) was calibrated using paired blood
lead and environmental data collected from ongoing remedial activities in the Box. The Box
data included more than 10 years of information regarding lead in blood, soil, and dust.
Approximately 4,000 children have participated in annual blood lead surveys in the Box since
Specifically, the Box model differed from the default model in two ways: (1) the Box model
reduced the bioavailability input from 30 percent to 18 percent and (2) accounted for exposure to
"neighborhood" soil in addition to yard soil and house dust. The results of the Box model are the
basis for the 700 mg/kg soil action level described in this ROD. If the default model were used,
a soil action level of 400 mg/kg would have been required to meet the target risk of a typical
child having no more than a 5 percent probability of a blood lead level of 10 |ag/dL or higher.
The results of the Box model are supported by the quantitative analysis of the paired blood lead
and environmental data. The regression analysis, which related blood lead levels to soil, dust,
and paint lead exposure variables, indicated that blood lead levels are most strongly influenced
by lead in house dust. Both contaminated soils and lead-based paint were identified as
contributors to house dust lead levels in the Basin.
There are many uncertainties in assessing risks to people from chemicals occurring in the
environment. These are described in more detail in Chapter 7 of the HHRA. Uncertainty
reflects limitations in knowledge and simplifying assumptions that must be made in order to
quantify health risks. Risk assessments involve several components, including analysis of
toxicity and exposure, each with inherent uncertainty. The major uncertainties include
representing chemical concentrations in environmental media, quantifying how people come in
contact with chemicals, interpreting the toxicological significance of the exposure, and
predicting how conditions may change in the future. In the case of lead, uncertainties related to
exposure to adverse health effects are reduced by reliance on blood lead as a measure of risk.
For example, the uncertainties of the Box model were less than those typically encountered at
CERCLA sites due to the use of the extensive Box database, which includes comprehensive
environmental air, soil, and dust data, paired with blood lead screenings conducted annually
since 1988. The screenings consistently recruited 50 percent or more of the eligible children
living in the Box. In addition, for both lead and arsenic, the understanding of toxicity is better
than most based on epidemiological and laboratory studies that have been subjected to multiple
scientific reviews (NAS 1993, 1999, and 2001).
1988.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-3
7.1.1 Baseline Risk Assessment, Harrison to Mullan
There are four primary tasks in a baseline risk assessment: (1) identification of COPCs;
(2) exposure assessment; (3) toxicity assessment; and (4) risk characterization. Risk
characterization is the summarizing step of risk assessment. The risk characterization integrates
information from the preceding components of the risk assessment and synthesizes an overall
conclusion about risk that is transparent, reasonable, and useful for decision-makers. The risk
assessment process identifies COCs that represent an ongoing or potential threat to human health
for particular groups of people at particular locations. As previously noted, this section focuses
on the COCs identified as the risk drivers for response actions described in this ROD, and does
not summarize the entire risk assessment.
Due to the large geographical area involved, the study area (from Harrison to Mullan) was
divided into eight principal subareas for the HHRA. These sub-areas were defined around
existing communities, including consideration of identified routes of potential human exposure,
public use patterns, and the results of environmental annual blood lead screening in each area.
The geographic areas are described in Section 5.1.1 of this ROD.
Identification of COCs
A total of eight metals were initially selected as COPCs and evaluated in-depth in the HHRA.
Two metals - lead and arsenic - have been identified as the COC's for the response actions
described in this ROD. Lead is the primary COC because lead exposures are predicted to exceed
target health goals at the largest number of locations and blood lead levels above 10 |ig/dL are
observed in the Basin. Arsenic is identified as a COC because concentrations exceeded target
health goals the second most frequently, although significantly less often than lead. Other metals
with media-specific concentrations exceeding health goals, such as cadmium and iron, were
limited to isolated locations or were co-located with lead and arsenic, and therefore are not a
primary concern. However, under certain circumstances, actions may be taken to address
cadmium in drinking water in private wells where cadmium may not be co-located with arsenic
and/or lead. Cadmium in drinking water was not found to be a concern in the majority of the
Basin; only five homes out of 100 had water concentrations exceeding cadmium's MCL. Only
one of these five homes also exceeded cadmium's health-based PRG in tap water. All of these
homes were on private wells and alternate sources of water have been provided to residents.
Cadmium is a COC under a future drinking water scenario if groundwater near source areas in
the vicinity of Ninemile and Canyon Creek were ever used as a drinking water source. Based on
cadmium MCL exceedances in groundwater, both in current drinking water from private wells
and future drinking water scenarios, cadmium in private wells will be addressed by the Selected
Remedy described in this ROD.
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Tables 7.1-1 through 7.1-4 present all chemicals and scenarios with risks and hazards above
target health goals that will be addressed by the Selected Remedy. These tables provide
exposure point concentrations (EPCs) for each of the chemicals detected in each media and
scenario for each of the evaluated areas. The EPCs were used in the risk equations to calculate
cancer risks and non-cancer hazards. The table includes the range of concentrations detected for
each COC, the EPC, and how the EPC was derived. Lead and arsenic concentrations are shown
in these tables as are cadmium, iron, and zinc in the limited places where exposure to these
additional chemicals resulted in hazards exceeding target health goals.
The majority of the COPCs were COCs for one of the two Lower Basin subsistence scenarios
evaluated in the HHRA, referred to as the traditional scenario. For the modern subsistence
scenario, the COCs were lead and arsenic. Subsistence scenarios are discussed separately in
Section 7.1.1 Subsistence Scenarios because the Selected Remedy does not address risks/hazards
from Lower Basin subsistence lifestyles. The chemicals and media exceeding target health goals
for subsistence receptors are shown on Table 7.1-5.
Exposure Assessment
The exposure pathways reviewed, including pathways evaluated qualitatively and quantitatively
evaluated are presented in Table 7.1-6, which presents the conceptual site model for human
health in tabular form. The receptors and pathways evaluated are in the following five current
exposure scenarios:
• Residential—evaluated for children and adults who live in the Basin. This
evaluation was conducted for a variety of pathways with potential exposure to
affected media in the home, in the yard and community, and from homegrown
vegetables. In addition, a potential future drinking water evaluation for shallow
groundwater in the Burke/Nine Mile area was performed. In general, EPA default
exposure factors for residential exposures were used to quantify risks. The
exposure factors are presented on Table 7.1-7.
• Neighborhood recreational—evaluated, in addition to the residential scenario, for
community soils (lead only), and incremental exposures for elementary-aged
school children at play in neighborhood creeks (exposure to sediments and
surface water) and waste piles. Site-specific exposure factors were generally used
for this scenario and are presented in Table 7.1-8.
• Public recreational—evaluated for children and adults who use developed parks
and playgrounds, and undeveloped recreational areas, whether they are residents
or visitors. Exposure scenarios included the incidental ingestion of soils,
sediments, and surface water and the ingestion of fish by sport fishermen.
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Site-specific exposure factors were generally used for this scenario and are
presented in Table 7.1-9.
• Occupational—evaluated for adult construction workers who would have
relatively short-term exposures to surface and subsurface soils during construction
projects. EPA default exposure factors for occupational exposures were used to
quantify risks, see Table 7.1-10.
• Subsistence—evaluated for two scenarios for both children and adults practicing a
subsistence lifestyle, traditional and modern. All subsistence scenarios were
assumed to take place within the confines of the Lower Basin. The traditional
subsistence lifestyle assumed people live in the flood plain of the lower Coeur
d'Alene River and practice an aboriginal lifestyle. The modern subsistence
lifestyle assumed people migrate to the flood plain during the summer and engage
in subsistence activities. In either scenario, people were assumed to consume
native vegetation and fish containing metals, although consumption rates for the
modern subsistence scenario were lower.
The risks from the presence of lead and other metals were evaluated separately for each of the
scenarios.
Toxicity Assessment
Table 7.1-11 provides cancer and non-cancer risk information relevant to the eight COPCs
evaluated in the risk assessment for soil, sediment, fish, and vegetables. Arsenic is the only
carcinogen.
Lead is evaluated by comparing predicted blood lead levels from site exposures with blood lead
levels known to be a health concern. The toxicity of lead is well understood and a wealth of
human data is available from many years of study that links specific health effects to levels of
lead in the blood. Lead induced neurological effects and decrements in IQ have been affirmed
by multiple consensus reviews prepared by EPA, the National Academy of Sciences (NAS), the
CDC, and the Agency for Toxic Substances Disease Registry (USEPA 1986, NAS 1993, CDC
1991, DHHS 1999).
The 1993 NAS lead review concluded the following:
The toxic effects of lead range from recently revealed subtle, subclinical
responses to overt serious intoxication. It is the array of chronic effects of low-
dose exposure that is of current public-health concern... We have several reasons
for emphasizing low-dose exposure. As recently noted by (Landrigan 1989), the
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subtle effects of lead are bona fide impairments, not just inconsequential
physiologic perturbations or slight decreases in reserve capacity.
The NAS has received a request and is considering a peer review of the scientific information
and risk analysis that forms the basis of the Selected Remedy described in this ROD.
While lead is a systemic poison (i.e., it adversely affects many systems and organs in the body),
the effect of greatest concern at blood lead levels observed in the Basin is lead's potential to
cause neurological developmental effects in children. Pregnant women also are a sub-population
sensitive to the effects of lead. Recognition of low-dose health effects and the need for primary
prevention is accepted among mainstream medical groups (see the American Academy of
Pediatrics Statement at: http://www.aap.org/policy/re9815.html or the CDC Lead Prevention
Fact Sheet http://www.cdc.gov/nceh/lead/factsheets/leadfcts.htm). Recent studies have
suggested that clinical treatment (chelation therapy), which effectively lowers blood lead levels
in treated children, is unable to prevent subtle neurological health effects (Rogan et al. 2001).
Furthermore, subtle health effects may occur at blood lead levels below 10 |ig/dL. Correlation
and regression analyses of data on blood lead levels and various health outcomes point to a
spectrum of undesirable effects that become apparent in populations having a range of blood lead
levels from 10 to 15 |ig/dL. These include effects on heme metabolism and erythrocyte
pyrimidine nucleotide metabolism, serum vitamin D levels, mental and physical development of
infants and children, and blood pressure in adults (USEPA 1990a and b; Wasserman et al. 1994;
Rothenberg et al. 1999). Although correlations between blood lead levels persist when examined
across a range of blood lead levels below 10 |ig/dL, the risks associated with blood lead levels
below 10 |ig/dL are less certain (Schwartz 1994). More recent literature further supports the
possibility of adverse consequence of exposures that result from blood lead levels below 10
|ig/dL (Lanphear et al. 2000).
The toxicity criteria for arsenic also are based on human data. Both the slope factor and the
reference dose for arsenic are derived from human epidemiological studies of long-term
exposure to arsenic in drinking water. The arsenic health effects of concern are skin, lung, and
bladder cancers and adverse non-cancer effects on the skin and circulatory system (NAS
1999, 2001).
EPA's reference dose (RfD) for iron is provisional at this time. Because iron is an essential
nutrient, the RfD must be protective of both iron deficiency and iron toxicity. Iron's provisional
RfD is the upper limit of mean dietary iron intakes (dietary plus supplemental) from the second
National Health and Nutrition Examination Survey (NHANES II) database, which contains
information from 20,000 individuals. This upper limit is the highest available value that ensures
sufficient iron to protect against iron deficiency and is not associated with adverse health effects
for the American population aged 6 months to 74 years, i.e., lifetime exposures. However,
certain sub-populations such as infants, pre-adolescent children, and pregnant women require
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higher intakes than the RfD for less than lifetime exposures (as long as 12 years for children).
As a result, there is insufficient information at this time to quantify the dose that is associated
with toxic effects and it is not known how much higher the provisional RfD could be and still not
be associated with toxicity. Iron toxicity to children in the United States has been associated
primarily with poisoning incidences from iron supplements where relatively large amounts of
iron were ingested (Berkovitch et al 1994; Morse et al 1997). Consequently, iron exposures in
the Basin that were up to two times iron's RfD are not likely to present a serious health concern.
Since Basin exposures to iron are below two times the RfD, iron exposures are unlikely to
present a health concern and are not the focus of remedial actions described in this ROD.
Risk Characterization
Lead health risks are discussed separately from non-lead risks because the methodologies for
assessing risk are different.
Lead Risk Summary. Lead health risk methods are unique owing to the ubiquitous nature of
lead exposures and the reliance on blood lead concentrations to describe lead exposure, toxicity,
and risks. Lead risks are characterized by predicting blood lead levels with computer models and
guidance developed by EPA (USEPA 1994c and 1998c).
In contrast to risk assessment methodologies for cancer or non-cancer risks, lead risk
assessments use central tendency exposure values to predict a central tendency (geometric mean)
blood lead level, rather than the reasonable maximum exposure values used in non-lead risk
assessments. The predicted geometric mean blood lead level is then used in conjunction with a
modeled log-normal distribution to estimate the probability of exceeding a blood lead level of 10
|ig/dL. This emphasis on blood lead integrates exposure, toxicity, and risk, which are separated
in other types of risk assessment. For other chemicals, risk is described in terms of an external
dose (e.g., mg/kg-day).
As previously mentioned, the EPA IEUBK Model was used to evaluate lead risks and to develop
soil action levels to achieve target health goals for reducing lead exposure pathways for children.
These goals are described in EPA national guidance (USEPA 1998c), which recommends that a
"soil lead concentration be determined so that a typical child or group of children exposed to lead
at this level would have an estimated risk of no more than 5 percent of exceeding a blood lead of
10 ng/dL." The guidance recommends that risks be assessed using an exposure unit defined as
the individual residence and other areas where routine exposures are occurring. The guidance
also recommends the evaluation of blood lead data where available, while noting that blood lead
data should "not be used alone to assess risk from lead exposure or to develop soil lead cleanup
levels." The HHRA was developed consistent with national guidance.
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Tables 7.1-12a and 7.1-12b show the results of the default risk model and the Box model, and
present the lead soil concentrations that would result in more than a 5 percent probability that a
typical child would exceed a blood lead level of 10 |ig/dL. The results of the Box model, which
was the better predictor, indicate that children in the Upper Basin are predicted to have a greater
than 5 percent risk of exceeding the 10 jag/dL blood lead level of concern for the baseline
residential exposure scenario. Lower Basin children from homes located in the flood plain, or
those that engage in extended recreational activities in flood plain areas, also are at a greater than
5 percent risk of experiencing elevated blood lead levels based on estimated soil concentrations
in those areas.
Site-specific analysis of blood lead data paired with environmental lead data suggests exposure
pathways that reflect exposures at both individual residence and neighborhood levels. The
analysis showed that, for most children, the home is the largest source of lead exposure. Blood
lead levels appear to be most closely related to lead in house dust (Figure 7.1-1) followed by
effects of lead in yard soil, the condition of interior lead-based paint, and the lead content of
exterior paint. House dust lead concentrations are total lead in dust and thus include all sources
of lead, such as lead dust from yard and neighborhood soils and paint.
The HHRA concluded that both lead in soils and paint will need to be addressed to effect
sufficient reductions in house dust lead concentrations. Site-specific analysis of alternative risk
reductions scenarios, summarized in Tables 7-12a and 7-12b, indicate that reduction of soil lead
concentrations to less than 700 mg/kg will be necessary to achieve the 5 percent risk criteria.
Programs for paint abatement and stabilization would be developed and implemented
concurrently with the soil remediation activities to mitigate exposure and minimize
recontamination.
Significant exposures also may result from recreation in areas with high lead concentrations in
the Upper Basin and throughout the floodplain areas west of the Box. This is a likely reason for
the higher than predicted blood lead levels observed among Lower Basin children. Currently
signs are posted at various Lower Basin recreational areas describing the hazards of lead and
providing information on how lead exposures can be prevented during recreational activities.
Additionally, swimming and water sport activities in disturbed sediment-laden surface water can
result in substantial increases in intake and lead absorption. Potential exposures to neighborhood
stream sediments in the Burke/Ninemile area and at public swimming areas in the Lower Basin
are of particular concern.
Non-Lead Metals Risk Summary. Summaries of the non-lead metal pathway/exposure
scenarios that exceed target risk goals are presented in Tables 7.1-13 through 7.1-19.
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Health risks for chemicals that cause cancer are calculated differently than those for chemicals
that cause non-cancer health effects. For non-cancer risks, if a person is exposed to a chemical
dose equal to or less than the "threshold," no adverse effects are expected. The "hazard
quotient" for a chemical is the exposure dose from the site (mg/kg-day) divided by the RfD
(mg/kg-day). If the hazard quotient is near 1, then no adverse effects are anticipated. Cancer
risks are calculated assuming that carcinogens, at any non-zero dose, contribute to cancer risk.
Cancer risks are presented as the incremental increase in the likelihood of developing cancer. A
cancer risk level of 1 x 10"6 describes an incremental increased risk of one in a million for a
given individual. EPA uses the general excess order of magnitude risk range of (10~6 to 10"4)
(1/1,000,000 to 1/10,000) as a "target range" within which risks are managed as part of a
Superfund cleanup. Cancer risks exceeding 10"4 and hazard quotients greater than 1 are
discussed below. Note that all final risk and hazard estimates are presented to one significant
figure only in the summary tables as recommended by EPA (USEPA 1989a) to reflect the
uncertainty and imprecision of the estimates. Therefore, a hazard quotient of 1 could range
between 0.95 and 1.4 and a risk of 2 x 10"5 could range between 1.5 x 10"5 and 2.4 x 10"5.
The results of the risk characterization for non-lead metals reported in the human health
risk assessment indicate that some exposure areas could pose an unacceptable threat of
non-cancer effects for some individuals and exposure media under Reasonable Maximum
Exposure (RME) conditions. The RME is defined as the highest exposure that is
reasonably expected to occur at a site (USEPA 1989a).
Hazards are greatest for children up to 84 months of age exposed to metals in yard soils, and
arsenic was the chemical with the highest hazards. Other media/scenarios with exceedances
above target health goals are young children and children/adults in the Burke/Ninemile area who
could ingest cadmium and zinc in groundwater in the future (groundwater in the Burke/Ninemile
area is not currently used as a drinking water source), and children/adults ingesting cadmium in
homegrown vegetables. Since lead and cadmium are co-located in garden soils (r = 0.9), the
Selected Remedy will address risks associated with cadmium in homegrown vegetables through
the remediation of lead-contaminated garden soils. Iron hazards also exceeded one or
contributed significantly to the total hazard exceeding one in a number of areas. However, iron
is not a focus of the Selected Remedy because (1) it is co-located with lead and arsenic in the
limited areas where its hazard quotient exceeded one, and (2) there are uncertainties surrounding
its toxicity because it is an essential nutrient.
Arsenic is the only carcinogen evaluated at the site. Only cancer risks estimates for residential
exposures in the Lower Basin and the Side Gulches were equal to or exceeded 10"4. All other
individuals in all other exposure areas had cancer risks within EPA's acceptable cancer risk
range. Cancer risks are summarized on Tables 7.1-13 and 7.1-19 for residential and subsistence
scenarios, respectively. For the residential scenarios, yard surface soil contributed the most to
cancer risk and, in the Side Gulches, tap water in private wells also contributed significantly to
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cancer risk (see Table 7.1-13). The HHRA concluded that arsenic concentrations in some Basin
yard soils may need to be addressed, independently of lead, to reduce risks and hazards. Table
7.1-20 provides various potential soil cleanup levels for arsenic based on a variety of target risk
goals and exposure scenarios. In general, arsenic risks did not exceed target risk goals in
drinking water, however, high concentrations of arsenic in a few scattered private wells may be a
health concern (no arsenic concentrations in any tap water sampled thus far exceeded the new
MCL of 10 ng/L).
No single neighborhood recreational cancer risks or non-cancer hazards exceeded target health
goals in the Upper Basin or Lower Basin; therefore, this scenario is not included on the
risk/hazard summary tables in this document. However, the Lower Basin, Kingston area, Side
Gulches, and Burke/Ninemile area presented hazards near the target hazard index of one and
risks were in the low 10"5 range. Thus, some combinations of child/adult residential plus
neighborhood recreational scenarios could result in hazard/risk estimates that are higher than
those discussed in this summary (other combinations than these two could also result in higher
risks).
There were no exceedances of target health goals for the occupational scenario viewing the Basin
as a whole; however, individual projects in specific locations where high-concentration materials
might be disturbed would need to ensure workers are not over-exposed.
Subsistence Scenarios
While subsistence exposures could not be evaluated using the IEUBK Model because the
magnitude of these exposures exceeded constraints of the Model, estimates of subsistence lead
intake were evaluated. For subsistence lifestyles practiced in the Lower Basin, blood lead levels
significantly above 10 |ag/dL would be likely, which is of particular concern for children and
pregnant women as discussed above. These exposures include but are not limited to, recreating
on contaminated beaches, swimming in the Coeur d'Alene River, gathering and eating water
potatoes and other tribal cultural plants throughout the wetlands, and eating large amounts of
All populations and pathways for subsistence lifestyles, including fish and water potatoes,
exceeded target risk goals for non-lead metals, see Figures 7.1-2 through 7.1-4 and Tables 7.1-17
through 7.1-19. For the Modern Subsistence scenario, arsenic and iron were the only chemicals
with hazard quotients greater than 1, similar to residential hazards. For the Traditional
Subsistence scenario, methylmercury in fish, manganese in soil and sediment, and cadmium in
water potatoes also had hazard quotients greater than 1 in addition to arsenic and iron.
fish.
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Surface soil and sediment contributed the most to cancer risks for the subsistence scenarios.
Cancer risks were higher than residential risks for the Modern Subsistence scenario, but similar
to those for the highest residential exposures. Risks for the Traditional Subsistence scenario
were an order of magnitude higher than those for the residential scenario.
7.1.2 Summary of Screening Level Risk Assessment, Coeur d'Alene Lake
Unlike the HHRA, risks were not estimated for the Coeur d'Alene Lake screening level risk
assessments. Rather, site-specific "safe" levels of COPCs were calculated based on recreational
usage. The calculated levels are referred to as risk-based concentrations (RBCs), and site
concentrations were compared to the calculated levels. A screening approach was selected for
this area (CSM Unit 4) to expeditiously determine if recreational use presented an unacceptable
risk to people frequenting the beaches.
Twenty-four beaches and wading areas adjacent to Coeur d'Alene Lake and the Idaho portion of
the Spokane River were included in the screening level evaluation. EPA, the local health
department, and BLM personnel familiar with the area selected the 24 beaches and parks most
frequently used by the public as areas of concern. Sampling activities were conducted at these
common use areas (CUAs) to collect surface soil, sediment, and water. Analytical results for
seven COPCs (the same as in the HHRA, except manganese and iron, which were excluded
because concentrations were sufficiently low, and copper, which was included because it was a
concern in the Box) were compared to RBCs considered protective of human health under
recreational use conditions. CUAs identified as exceeding a RBC were further evaluated in the
HHRA. In contrast, sites with concentrations below the health-protective RBCs were considered
to pose no public health risks and were excluded from further consideration.
Because children are the most sensitive population group, RBCs were developed to ensure
protection of children and these RBCs would also be protective of adults. The RBC for soil and
sediment assumes children will be exposed to beach sand through ingestion and dermal contact
and will ingest more soil (i.e., eat more dirt) than they would in their home setting on a daily
basis. The RBC for water assumes children will play in the near-shore area and be exposed to
site chemicals through incidental ingestion of disturbed (or stirred-up) sediments in water and
through dermal absorption of chemicals. Children are assumed to play in soil/sediment and
water two days per week (all day, 10+ hours) for four months of the year.
Lead RBC values were calculated using the IEUBK Model for lead. RBCs were calculated using
EPA's target risk goal of a typical child having no more than a 5 percent risk of a blood lead
level above 10 |ig/dL. An initial soil/sediment RBC of 1,400 mg/kg was identified as protective
at beaches if soil at the homes contained no greater than 200 mg/kg of lead. If lead
concentrations in soil or sediment exceeded 1,400 mg/kg, then the CUA was retained for further
evaluation. After screening soil, a second step involved combining sediment and surface water
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exposures. If combined exposures resulted in a predicted risk of a typical child having greater
than a 5 percent risk of exceeding a blood lead level of 10 |ig/dL, then the site was retained for
further evaluation.
For chemicals other than lead, RBCs were calculated using standard EPA risk equations and
solving for a concentration. Target risk goals were established at 1 x 10"5 for carcinogens and a
hazard quotient of 0.1 for non-carcinogens (one-tenth of the EPA RfD). Arsenic was the only
carcinogen evaluated in this assessment. Arsenic has both carcinogenic and non-carcinogenic
potential effects. The RBC for arsenic was selected based on non-carcinogenic potential in
children because this RBC was lower than the RBC based on the cancer endpoint. Furthermore,
because arsenic's soil RBC is below an estimate of its natural background concentration of 35
mg/kg for the Lake Coeur d'Alene area, site soil and sediments were screened against the
background level rather than the RBC.
Once calculated, RBCs were compared to an upper 95th confidence limit of the arithmetic mean
for non-lead chemical concentrations in soil, sediment, and surface water at each site. For lead,
the arithmetic sample mean was used as the exposure point concentration. Drinking water
concentrations (only two locations had a drinking water source) were compared to drinking
water MCLs.
The comparison of RBCs to site concentrations revealed that only two of the 24 sites evaluated
had chemicals in soil and sediment exceeding their respective RBC, Harrison Beach North and
Blackwell Island. Lead and arsenic were present in concentrations above the RBC and were
identified as COCs at Harrison Beach North and at Blackwell Island in soil and sediment. In
addition, lead in drinking water at the Harrison Beach Campground was found to be
approximately equal to the tap water action level for lead (lead does not have an MCL; instead,
tap water levels requiring differing "actions" are set based on certain criteria). These two areas
were retained for further evaluation in the HHRA. The other 22 sites required no action. The
HHRA concluded that Blackwell Island did not have risks above target health goals (see
Section 7.1.1); therefore, no actions are required at that location. Harrison Beach was evaluated
in the HHRA as part of the Lower Basin area and has been remediated as part of the UPRR
removal action.
The HHRA recognized fish consumption in Coeur d'Alene Lake as a data gap; therefore, a
comprehensive fish sampling field effort was started in 2002.
7.1.3 Summary of Screening Level Risk Assessment, Spokane River, Washington State
The Spokane River screening evaluation followed the methodology for the Coeur d'Alene Lake
screening evaluation—RBCs were developed and CUA concentrations were compared to the
RBC values. CUAs with metal concentrations in sediment below the RBCs were considered to
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require no further actions, while CUAs with concentrations over RBCs were further evaluated.
The same COPC metals that were identified in the HHRA were evaluated along the Spokane
River.
Eighteen CUA sites located on public and private lands along the banks of the Spokane River,
from the Washington/Idaho border to the confluence with the Columbia River were selected for
sampling (CSM Unit 5). As with the Coeur d'Alene Lake sites, CUA selection involved
personnel from local agencies (Washington Department of Ecology, Spokane Regional Health
District, USFS) and local stakeholders providing information to the EPA on the areas most
frequently used by people where the largest amounts of fine-grained sediment were regularly
deposited. The rocky and boulder-dominated beach areas along the upper river are generally not
a health concern because it is the finer-grained shore-line sediments that stick to children's hands
and are ingested. Finally, because the northern side of the lower Spokane River near the
confluence with the Columbia River is tribal land, the Spokane Tribe of Indians provided
information to EPA on the areas most frequently used by the Tribe.
The RBCs developed for the Spokane River, Washington were similar to those developed for the
Idaho Lake sites in that they were based on recreational river use and child exposures two days
per week for four months a year. However, because of requests made in public participation
forums by concerned residents and differing regulations in Washington State than in Idaho,
different lead model inputs and target health goals were used to develop the Spokane RBCs. In
addition, the Spokane area has different background concentrations of metals than the area
surrounding Coeur d'Alene Lake. Therefore, the RBCs developed for the Spokane sites were not
the same as those developed for Coeur d'Alene Lake. Lead in particular is lower, 700 mg/kg
rather than 1,400 mg/kg. Although the screening levels differed in the two screening
assessments, the final lead action levels along the Coeur d'Alene River, Lateral Lakes, and the
Spokane River are consistent at 700 mg/kg.
Assumptions regarding the amount of soil, dust, and beach sediment ingested were different for
the Spokane River than those used for Coeur d'Alene Lake. The Spokane assessment did not
include suspended sediment ingestion as was done for Coeur d'Alene Lake and the Spokane
RBC was based on differential weighing of exposures between river and the residence. For the
Spokane River assessment, the weighting was reversed to give two-thirds weight to the River
exposure during exposure days. For Coeur d'Alene Lake, during each of the two days per week
of exposure, two-thirds of the exposure came from the residence and one-third came from the
Lake.
The arsenic RBC is lower because of the target health goal of 1 x 10"6 required for use in
Washington State rather than the 1 x 10"5 goal used in Idaho and because background arsenic
concentrations in the Spokane area are also lower. The selected RBC for arsenic of 10 mg/kg is
a local natural background concentration for the metal as identified by the Washington State
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Department of Ecology (Ecology 1994). This background value is based on upland soil analysis,
not sediment sampling.
For each metal except lead, the RBC was compared to a 95 percent upper confidence limit
(UCL95) of the mean concentration in sediment at each CUA. The lead RBC was compared to
the mean concentration. Generally, measured concentrations of the metals were highest
upstream of the Upriver Dam pool (that is, approximately river mile 84) and were considerably
lower downstream of this area. For most locations downstream of Upriver Dam, sediment
concentrations were only slightly elevated above background concentrations. While the RBCs
were developed to be protective only of recreational-type exposures, the beach concentrations
downstream of Upriver Dam indicate no use restrictions for other types of exposures that would
be required to protect public health.
Of the 18 CUAs evaluated, only one, River Road 95, had both lead and arsenic concentrations
exceeding the RBCs. Three additional CUAs (Harvard Road North, Barker Road North, and
North Flora Road) had arsenic concentrations over the arsenic RBC of 10 mg/kg. Arsenic
concentrations at these locations represent cancer risks in the 10"5 range, above Washington
State's target risk goal of 1 x 10"6 for the general public. Therefore, these four areas were
retained for further evaluation. Arsenic and lead concentrations at these four locations are
presented on Table 7.1-21.
Arsenic concentrations exceeded the RBC at 6 of the 18 sites: Harvard Road S., Plante's Ferry
Park, People's Park, Riverside Park at W. Fort George Wright Bridge, Jackson Cove, and
Horseshoe Point Campground. However, for these sites, there are additional areas of uncertainty
that may warrant consideration. These are:
• The concentrations of arsenic were only marginally greater than the natural
background concentration of 10 mg/kg.
• The arsenic concentrations at the six beaches ranged from 12 to 16 mg/kg, which
may be within the natural background range for fine particles of river sediments.
(The Spokane arsenic background concentration of 10 mg/kg is based on particles
of a larger size than the sampled particles, and the larger-size particles sampled
from the Spokane River had lower concentrations.)
• The additional cancer risk from exposures to arsenic concentrations of 2 to
6 mg/kg greater than the background concentration is not significantly greater
than the risk due to naturally occurring levels of arsenic (an increase in the chance
of developing cancer of 1 to 2 in 1,000,000). Note that there are risks above 1 x
10"6 from exposures to the natural background concentration of 10 mg/kg.
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The screening-level risk assessment did not evaluate fish consumption along the river; however,
the USGS sampled fish for the State of Washington Department of Ecology in the area and
analyzed them for several metals, including lead. The lead data from whole fish was evaluated
in the HHRA for the subsistence scenarios and some lead concentrations in the whole fish data
were found to be a potential concern (contributing to blood lead levels above the target health
goal) for children and pregnant women if they ingested large amounts of fish. Lead
concentrations in filet and whole fish are presented on Table 7.1-22.
In response to metals contamination, the Washington State Department of Health and Spokane
Regional Health District have issued two health advisories for the upper reaches of the Spokane
River. The first advisory alerts visitors to the presence of elevated lead in shoreline and beach
sediments frequented by river and park users. The second alerts visitors to elevated lead
concentrations in fish. Recommended fish consumption limits for children and adults have been
established, with particular emphasis toward children and pregnant women or women
considering pregnancy.
The locations identified in the screening level risk assessment as above RBCs or background
levels were further assessed by EPA in coordination with the State of Washington Department of
Ecology. Additional sampling was performed in depositional areas upstream of Upriver Dam.
Analysis of these additional data resulted in 10 beaches selected for cleanup (the four identified
in the screening level risk assessment, plus six additional depositional areas identified in
subsequent sampling events, see Figure 12.4-1 for locations). These 10 beaches were identified
for cleanup in accordance with the State of Washington Model Toxics Control Act (WAC 173-
340-740).
7.1.4 Basis for Remedial Action
The response actions selected in this ROD are necessary to protect human health and the
environment from both ongoing and threatened releases of hazardous substances into the
environment. Such a release or threat of release may present an imminent and substantial
endangerment to public health, welfare, or the environment. A summary of risks to human
health is presented below.
Specifically for the Upper Basin and Lower Basin:
• The Box model predicts lead risks above target risk goals for approximately 25
percent of the residential yards in the Basin.
• Analyses show that lead in house dust is the primary pathway of exposure for
children, and that yard and community soils and lead paint contribute lead to
house dust.
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• Lead exposure in other areas, recreational soils and sediments, whole fish, and
waste piles may contribute significantly to children's blood lead levels.
• Predicted arsenic exposures from yard soils in the Upper Basin and Lower Basin
and from drinking water in selected private wells exceed target health goals.
Generally, arsenic exposure occurs in yards requiring remediation for lead
exposure.
• A small number of private wells exceed the MCL for cadmium.
• Cadmium and zinc levels in shallow groundwater near Canyon Creek and
Ninemile Creek are predicted to result in hazards above target health goals if the
water is used as a drinking water source in the future.
• Cadmium levels in homegrown vegetables result in hazards above target health
goals.
• Risks above target health goals are predicted for all chemicals and media if
subsistence lifestyles are practiced in the Lower Basin.
Specifically for Coeur d'Alene Lake:
• No sites exceeded target health goals; thus, actions are not required around the
lake to protect human health except at Harrison Beach, which has been
remediated as part of the UPRR removal action.
• Fish species caught for human consumption are being sampled in 2002.
Specifically for Spokane River, Washington:
• Four locations between Upriver Dam and the Idaho border exceeded background
concentrations for arsenic, equating to an incremental increase in cancer risks
from recreational use in the 10"5 range, above Washington State's target cancer
goal of no more than a 1 x 10"6 additional chance of contracting cancer for
exposure from a site.
• One of the above four locations exceeded the RBC for lead, indicating potential
risks to children of exceeding the 10 |ig/dL level of concern.
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• Lead concentrations in fish, both whole and filet, could potentially contribute to
blood lead levels above the 10 |ig/dL level of concern.
• Further assessment of additional beaches (not evaluated in the initial screening
level assessment) by Washington State under the State's Model Toxics Control
Act (MTCA) regulations resulted in six additional beaches selected for cleanup
due to concentrations above RBCs and/or background concentrations under
MTCA protocols. These six beaches plus the four locations identified in the
screening level risk assessment were selected as requiring actions to protect
human health.
At present, the risks to persons, including Spokane tribal members and others who may practice
a subsistence lifestyle in the Spokane River area, are not fully understood. EPA and the Spokane
Tribe are cooperating in planning additional testing and studies that will be implemented to
evaluate the potential exposures to subsistence users. The results of those tests and studies will
determine appropriate future response actions to be taken, if any.
As previously mentioned, the Selected Remedy includes a complete remedy for protection of
human health in the communities and residential areas of the Upper Basin and Lower Basin.
Certain potential exposures outside of the communities and residential areas of the Upper Basin
and Lower Basin are not addressed by this ROD, and will continue to present risks of human
exposure to hazardous substances. These potential exposures impacting human health include:
• Recreational use at areas in the Upper Basin and Lower Basin where cleanup
actions are not implemented pursuant to this ROD
• Subsistence lifestyles, such as those traditional to the Coeur d'Alene and Spokane
Tribes
• Potential future use of groundwater that is presently contaminated with metals
7.2 SUMMARY OF ECOLOGICAL RISKS
The EcoRA for the Coeur d'Alene Basin (USEPA 2001a) was prepared as part of the Coeur
d'Alene Basin RI/FS. The report characterized risks for aquatic and terrestrial organisms (i.e.,
plants and animals) exposed to hazardous substances associated with mining activities in the
Coeur d'Alene River Basin in Idaho and the (downstream) Spokane River in Washington. The
EcoRA evaluated potential threats to the environment in the absence of any remedial action
under current and future land uses (which are assumed to be similar to current land uses for the
purpose of assessing ecological risks). It identified and characterized the toxicity of chemicals of
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potential ecological concern (COPECs), possible exposure pathways, ecological receptors,
assessment and measurement endpoints, and a range of possible risks under current conditions.
These aspects of the document are explained in the various sections of the EcoRA and are
summarized below.
EPA established the Coeur d'Alene Basin Ecological Risk Assessment Work Group (EcoRA
Work Group) to provide an avenue for stakeholder input during development of the EcoRA.
Membership in the EcoRA Work Group was open to any parties who expressed an interest and
asked to be included. Using regularly scheduled teleconferences and milestone meetings, the
EcoRA Work Group provided a forum by which interested parties could be involved early and
often in the evaluation process. Groups to which information was provided include the State of
Idaho, State of Washington, Coeur d'Alene Tribe, Spokane Tribe, Colville Tribe, USFWS, and
other governmental partners, public interest group members, newspaper reporters, legislative
staffers, mining company representatives, and other parties.
The EcoRA study area was the same as the RI/FS study area, which is described in Section 1.0
(Figure 1.0-1). It included the Coeur d'Alene River and associated tributaries, Coeur d'Alene
Lake, and the Spokane River downstream to the Washington State Highway 25 bridge at Fort
Spokane on the Spokane Arm of Lake Roosevelt. Collectively, this area is referred to as the
Coeur d'Alene Basin. The specific portion of the study area upstream of Coeur d'Alene Lake is
usually referred to as the Upper Basin and Lower Basin.
The study area was divided into five units (called conceptual site model [CSM] units) that were
differentiated based on geomorphology, mixes of hazardous substances, and habitats (Figures
7.2-1 through 7.2-5). As a result of differences in habitats among the CSM units, the ecological
receptors also vary, as discussed below in the next section (Habitat Types). The CSM units are
briefly described here.
CSM Unit 1 (Figure 7.2-1) contains many of the primary sources for mining-related hazardous
substances (metals) including mine workings, waste rock and other mining waste, mine tailings,
concentrates, and other process wastes, and artificial fill (tailings and waste rock in roads,
railroads, and building foundations). CSM Unit 1 includes the upper watershed of the South
Fork (above Wallace) and associated creeks (Canyon Creek and Ninemile Creek). It also
includes Prichard Creek, Beaver Creek, Moon Creek, Big Creek, and Pine Creek, all of which
discharge to the North Fork or into the South Fork downstream of Wallace.
CSM Unit 2 (Figure 7.2-2) contains the remainder of the primary sources of mining-related
hazardous substances within the surface water and sediments of mid-gradient streams and small
tributaries within the main stem watershed downstream to Cataldo. Most of the Bunker Hill
Superfund Site is in CSM Unit 2. The primary sources within this CSM unit are similar to those
in CSM Unit 1.
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CSM Unit 3 (Figure 7.2-3) consists of the low-gradient part of the main stem of the Coeur
d'Alene River, from the Old Highway Bridge at Cataldo to Coeur d'Alene Lake. It includes the
lateral lakes that occur within the floodplain of the river. Mining-related hazardous substances
within this CSM unit are found in the beds and banks of the river, contaminated floodplain soils,
surface water, groundwater, and biota (plants and animals) that have accumulated metals.
CSM Unit 4 (Figure 7.2-4) consists of Coeur d'Alene Lake, where mining-related hazardous
substances include contaminated sediments and surface water. In addition, nutrients are of
significant concern because they can change the trophic status of the lake and can cause
secondary releases of metals from contaminated sediments.
CSM Unit 5 (Figure 7.2-5) consists of the Spokane River. Mining-related hazardous substances
are found mainly in contaminated sediments and surface water.
The EcoRA included three main components, including Problem Formulation, Analysis, and
Risk Characterization. These phases are presented in various sections of the EcoRA report, and
key portions are briefly summarized here.
7.2.1 Habitat Types
Within the Basin, ecological risks associated with mining-related hazardous substances were
evaluated within six habitat types. The occurrence of these habitats within different portions of
the Basin varies, and the typical species associated with the habitats also vary from one portion
of the Basin to another. The habitats and a few typical species include the following:
• Riverine habitat includes the wetlands and deepwater habitats within the channels
of creeks and rivers of CSM Units 1, 2, 3, and 5. Typical fish expected to occur
in this habitat include westslope cutthroat and bull trout, sculpin, mountain
whitefish, and, in some portions of the Basin, introduced species such as rainbow,
brook, and brown trout. In lower-elevation areas, typical fish species include
chinook salmon, smallmouth bass, northern squawfish, and sucker. Characteristic
wildlife species include salamanders, common merganser, osprey, bald eagle,
spotted sandpiper, American dipper, water shrew, raccoon, mink, and river otter.
• Lacustrine habitat includes wetlands and deepwater habitats that occur in
depressions (such as the lateral lakes and Coeur d'Alene Lake) or in dammed
river channels (such as the Spokane River upstream of Post Falls Dam). Most
plants occur as phytoplankton or as submerged vegetation. Typical fish include
many of the same ones as in riverine habitat, in addition to largemouth bass,
yellow perch, and northern pike. Characteristic birds and mammals include
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tundra swan, lesser scaup, common goldeneye, common merganser, osprey, bald
eagle, tree swallow, little brown myotis (bats), and river otter.
• Palustrine habitat includes wetlands that are dominated by trees, shrubs, and other
persistent emergent wetland plants. This habitat occurs in smaller areas within
CSM Units 1, 2, 4, and 5, relative to larger areas within CSM Unit 3. Typical
plants include wild rice, water potato, equisetum (horsetail), cattail, cottonwood,
and willow. Characteristic wildlife species include spotted frog, salamanders,
great blue heron, Canada goose, tundra swan, wood duck, mallard, bald eagle,
common snipe, little brown myotis (bats), raccoon, mink, beaver, muskrat, and
white-tailed deer.
• Riparian habitat is terrestrial habitat that is associated with one of the previously
mentioned wetland habitats, most often the riverine habitat. It occurs along
stream channels and around lakes within CSM Units 1, 2, 4, and 5, but is much
more extensive in CSM Unit 3. Typical plants include reed canary grass, cow-
parsnip, spiraea, cottonwood, alder, and willow. Common wildlife include
salamander, spotted frog, northern harrier, American kestrel, wild turkey, great
horned owl, Swainson's thrush, American robin, song sparrow, shrew, long-
legged myotis (bats), raccoon, mink, white-tailed deer, muskrat, mice, and vole.
• Agricultural habitat includes portions of CSM Unit 3 that are used mostly for
pasture and hay fields. Redtop, reed canary grass, oats, and barley are typical
plants in this habitat, which may be seasonally flooded and used by waterfowl and
other wetland species. Common wildlife species include Canada goose, northern
harrier, wild turkey, common snipe, American robin, shrew, white-tailed deer,
mice, and vole.
• Upland habitat occurs outside the floodplains of the creeks and the South Fork
within CSM Units 1 and 2. Typical plants include grasses, shrubs, pine, hemlock,
red cedar, Douglas-fir, and Rocky Mountain maple. Representative birds and
mammals include American kestrel, ruffed grouse, wild turkey, great horned owl,
Swainson's thrush, shrew, mule deer (which also serves as a surrogate for elk),
mouse, and vole.
The bird species listed above, except for ruffed grouse and wild turkey, are protected under the
Migratory Bird Treaty Act (MBTA). This statute protects almost all species of native birds in
the United States from unregulated "take," which can include poisoning at contaminated sites.
The MBTA is the primary tool of the USFWS and other federal agencies in managing migratory
birds.
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Some of the species mentioned above are considered to be "special-status species" for the
EcoRA. These include federally listed endangered or threatened species, those identified by the
USFWS as species of concern, state-listed sensitive plant species, and culturally significant plant
species. Examples include the bald eagle, black tern, gray wolf, lynx, bull trout, westslope
cutthroat trout, spotted frog, Ute ladies'-tresses, and water potato.
7.2.2 Ecological Receptors
Although more than 80 different species were evaluated in the risk assessment, it is not feasible
to evaluate ecological risks to every plant, animal, and microbial species that may be present and
potentially exposed within the Coeur d'Alene Basin. Consequently, receptors of high ecological
or societal value or those believed to be representative of broader groups of organisms were
selected for evaluation. Representative ecological receptors were selected on the basis of current
information on habitat types present and potential for exposure in the Basin. Each receptor was
chosen to represent a trophic category and particular feeding behaviors (e.g., diving birds versus
shorebirds) that would represent different modes of exposure to COPECs. Thus, the species that
were chosen for evaluation represent numerous trophic levels including hundreds of similarly
exposed species in the Basin. The following criteria were used to select potential receptors:
• The receptor does or could use habitats present in the Basin.
• The receptor is important to either the structure or function of the ecosystem.
• The receptor is statutorily protected (i.e., threatened or endangered species,
migratory birds) or is otherwise highly valued by society (i.e., species of cultural
importance).
• The receptor is reflective and representative of the assessment endpoints for the
Coeur d'Alene Basin.
• The receptor is known to be either sensitive or highly exposed to COPECs in the
Coeur d'Alene Basin.
Where appropriate, the same receptors were used for more than one CSM unit to increase
efficiency and consistency of the EcoRA and to allow for the comparative evaluation of CSM
units (Table 7.2-1). Many of the receptors selected for evaluation are listed above for the
different habitat types.
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7.2.3 Ecological Management Goals and Assessment Endpoints
Ecological management goals, assessment endpoints, and measures for the Coeur d'Alene
EcoRA were developed through consultation with the EcoRA Work Group and are consistent
with the NCP and EPA guidance. The ecological management goals are:
• Maintenance (or provision) of soil, sediment, water quality, food source, and
habitat conditions capable of supporting a "functional ecosystem" (as defined
below) for the aquatic and terrestrial plant and animal populations in the Coeur
d'Alene Basin
• Maintenance (or provision) of soil, sediment, water quality, food source, and
habitat conditions supportive of individuals of special-status biota (including
plants and animals) and migratory birds, protected under the MBTA, likely to be
found in the Coeur d'Alene Basin
These ecological management goals include the need to reduce the toxicity and/or toxic effects
of hazardous substances released by mining activities to ecological receptors within the Basin,
and also the need to provide habitat conducive to the recovery of special-status species. By
protecting the integrity of the food chain, water, and other natural resources, as well as habitat
structure, the ecological management goals should be fulfilled. The ecological endpoints to
evaluate these objectives are summarized below.
Assessment endpoints for the Coeur d'Alene Basin were developed in collaboration with the
EcoRA Work Group, and are consistent with the NCP and EPA guidance. The selection of the
assessment endpoints is crucial to the EcoRA because they define the important ecological
values that are to be protected. They are developed on the basis of known information
concerning the contaminants present, the receiving site, and the risk management goals. The
assessment endpoints for the Coeur d'Alene Basin were based on the following principal criteria:
• Ecological relevance
• Political and societal relevance
• Susceptibility to known or potential stressors
• Consistency with ecological management goals
The protection of assessment endpoints for the Coeur d'Alene Basin as a whole will be
considered to result in a "functional ecosystem" if soil, sediment, water quality, food source, and
habitat conditions are capable of supporting natural populations of plants and animals; there are
no direct adverse effects on migratory birds or special-status species; and habitat conditions are
conducive to recovery of special-status species. Assessment endpoints were developed for four
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levels of biological organization: individual; population; community; and habitat, ecosystem, and
landscape. Assessment endpoints for each level are described in the following text.
Assessment endpoints were identified on the basis of potential effects on individuals of
migratory birds and threatened or endangered species within the Coeur d'Alene Basin. The
effect levels for these endpoints were established to eliminate adverse effects to individuals by
considering no-effect or minimal-effect levels of metals for the receptor species.
Assessment endpoints that pertain to potential effects on populations of species that are
characteristic of natural habitats within the Basin were identified for the following: fish,
amphibians, birds, mammals, and special-status plants (e.g., those that have cultural significance
and those that are of special concern to state or federal agencies). Effect levels for these
endpoints were established to eliminate adverse effects that may be experienced by greater than
20 percent of the naturally occurring populations.
Assessment endpoints also were identified that pertain to potential effects within the Basin on
aquatic and terrestrial plant and invertebrate communities that are characteristic of natural
habitats in the region. The effect levels for these endpoints were established to eliminate adverse
effects to organisms that make up aquatic and terrestrial plant and invertebrate communities.
In addition, assessment endpoints were identified that pertain to potential direct and indirect
effects of mining-related hazardous substances on habitats, ecosystems, and the landscape within
the Coeur d'Alene Basin for the following: soil processes (based on viability and sustainability
of the soil microbial community to support nutrient cycling and other ecosystem processes
necessary for higher plants and animals), and physical and biological characteristics (landscape
attributes necessary for sustaining plant and animal communities).
These assessment endpoints were evaluated through a series of measures (sometimes referred to
as measurement endpoints) that are described below in the Analysis of Ecological Risk section.
7.2.4 Chemicals of Potential Ecological Concern
The media evaluated in the EcoRA included soil, sediment, and surface water. Groundwater,
although contaminated in the Basin, was not evaluated. Animals do not come into contact with
it, and the exposure of plants could best be evaluated through concentrations of COPECs in the
soil (i.e., reference toxicity data are not available for evaluation of plant exposures to
groundwater). Furthermore, groundwater interacts with surface water, which was evaluated in
the EcoRA. The COPECs for the Coeur d'Alene Basin were tentatively identified during the
evaluation of nature and extent of contamination in the draft Technical Work Plan for the RI/FS
(USEPA 1998b). The following COPECs were carried forward to the EcoRA and were the focus
of all subsequent evaluations in that report:
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• Soil - arsenic, cadmium, copper, lead, and zinc
• Sediment - arsenic, cadmium, copper, lead, mercury, silver, and zinc
• Surface water - cadmium, copper, lead, and zinc
The EcoRA relied on numerous sets of historical data that included concentrations of COPECs in
both abiotic media (soil, sediment, and surface water) and biological media (plant and animal
tissue) collected by EPA, USGS, USFWS, BLM, University of Idaho, and other investigators.
Additionally, URS Greiner, Inc., USGS, and CH2M HILL collected additional soil, sediment,
groundwater and surface water samples on behalf of EPA beginning in 1997.
The abiotic media data (including soil, sediment, and surface water) were evaluated initially
using general data qualification review and reduction protocols (presented in Appendix A of the
EcoRA). The data were then further reduced for the specific uses of the EcoRA. The data
qualification review served as a mechanism to apply consistent rules for qualification of data
independent of the laboratories or individual data validators, and then to resolve multiple values
within a given sample to arrive at a single value per chemical per sample. Following data
qualification, the data set was reduced using an automated data selection processor. The data
reduction routine was used to select the best value for each analyte or group of analytes.
For evaluation of terrestrial receptors, the data for soil and sediment were combined within a
given habitat type and were evaluated as a single medium. The basis for evaluating soil and
sediment as a single medium was that, in many cases, soils from either the same sampling
location or from sampling locations very close to each other were labeled "soil" in some
sampling events and "sediment" in others. This occurred predominantly in the agricultural
floodplain areas and was a result of the condition of the site during sampling. When the ground
was dry during sampling, the samples were typically identified as "soil," whereas when it was
wet or flooded, the samples were identified as "sediment." Similarly, the same substrate material
represents soil for terrestrial receptors during dry periods and sediment for waterfowl during
flooded periods. In either case, the soil-sediment originated from the same source material so the
approach for evaluating them together was considered valid.
For evaluation of aquatic receptors, the surface water and sediment data were reduced to those
samples occurring in lakes, rivers, and wetlands. Sediments were not combined with soils for
aquatic receptors because the evaluation was limited to specific habitat types that are typically
wet year-round (lakes, rivers, wetlands).
Section 2.4 and Appendix A of the EcoRA provide a discussion of the data quality objectives
(DQOs) as well as the data qualification and reduction procedures used to create the final
database that was used for risk evaluations.
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Tables 7.2-2 through 7.2-5 provide a summary of the occurrence and distribution of COPECs by
medium (soil-sediment, sediment, and surface water) in various portions of the Basin. The tables
show the frequency of detection as well as minimum, maximum, mean, and UCL95 of the mean
concentrations. Analyses in subsequent portions of the EcoRA were conducted to determine
which of the COPECs posed risks to ecological receptors; these chemicals vary by receptor and
medium and are referred to as COECs.
7.2.5 Analysis of Ecological Risk
Three categories of measures were evaluated during the analysis phase: measures of exposure,
measures of effects, and measures of ecosystem and receptor characteristics. The measures are
described in the following text.
Exposure Analysis
The exposure analysis evaluated the contact or co-occurrence of mining-related hazardous
substances and the assessment endpoint receptors. The measures of exposure used in the EcoRA
were developed for each of the assessment endpoints and habitats within each of the CSM units.
They included concentrations of COPECs in soil-sediment, surface water, and biota (plants and
animals) to which the receptors could be exposed.
Many studies have been conducted in the Coeur d'Alene Basin to characterize exposures of
plants and animals to mining-related hazardous substances, as summarized in Section 2.4 of the
EcoRA. These include measurements of chemical concentrations in both abiotic media (soil-
sediment, and surface water) and biological media (plant and animal tissue). COPEC
concentrations in abiotic media are summarized in Tables 7.2-2 through 7.2-5. Data from the
numerous studies of accumulation of metals in biota in the Coeur d'Alene Basin may be
segregated into three groups based on their potential usability in the exposure estimates. Some
data were used to estimate food-web exposures to consumer species (e.g., results from whole-
body analyses of fish, invertebrates, and small mammals; analyses of plant tissues). Other data
were used for estimating metals exposure of the species from which the tissues were obtained
(e.g., metal concentrations in target organs [liver, kidney, and blood]; measures of delta-
aminolevulinic acid dehydratase [ALAD] inhibition in blood). The last group of data, including
metal concentrations in mammal hair, bird feathers, and fish fillets, were not readily usable in
EcoRAs because of limitations on interpretability of their relation to ecological effects.
The potential routes of exposure indicate the means by which chemicals are transferred from a
contaminated medium to ecological receptors. The routes by which ecological receptors may be
exposed to COPECs in the Coeur d'Alene Basin include:
• Birds and mammals - ingestion of soil-sediment, surface water, and food
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• Fish - ingestion and direct contact with sediment and surface water
• Benthic invertebrates - ingestion and direct contact with sediment or surface water
• Aquatic plants - root uptake and direct contact with sediment and surface water
• Amphibians - direct contact with surface water and soil-sediment
• Terrestrial plants - root uptake from soil-sediment
• Terrestrial invertebrates - ingestion and direct contact with soil-sediment
• Soil processes - direct contact of microbes with soil-sediment
Birds and mammals experience exposure through multiple pathways including ingestion of
abiotic media (soil, sediment, and surface water) and biotic media (food) as well as inhalation
and dermal contact. To address this multiple pathway exposure, modeling was required.
Exposure estimates for each representative species were generated based on model assumptions,
life history parameters, and estimated concentrations in exposure media (soil, sediment, and
surface water) and food sources as described in Section 3.1 of the EcoRA. The end product or
exposure estimate for external exposures for birds and mammals is a dosage (amount of chemical
per kilogram receptor body weight per day [mg/kg/d]) rather than a media concentration as is the
case for the other receptor groups (fish and other aquatic organisms, terrestrial plants, terrestrial
invertebrates, and soil [microbial] processes). This is a function of both the multiple pathway
approach as well as the typical methods used in toxicity testing for birds and mammals (as
described in Section 3.2 of the EcoRA). Summaries of total (i.e., sum over all pathways) and
partial (pathway-specific) exposure estimates are presented and compared to toxicity values in
Section 4.1 of the EcoRA.
Exposure-point concentrations for soil-sediment and surface water incorporated into the
exposure model for birds and mammals were the upper UCL concentrations. These values were
selected to provide a conservative representation of exposures most likely to be experienced by
birds and mammals within the Coeur d'Alene Basin. Because wildlife are mobile and their
exposure is best represented by the average concentration within areas they inhabit, UCL95 is the
measure traditionally used for estimation of exposure for wildlife.
Internal exposures consist of concentrations of COPECs in tissues of receptor species. These
concentrations were measured directly from certain field-collected birds and/or mammals; for
others, they were modeled using site-specific or literature-derived information. They were then
compared to available literature information for concentrations of chemicals in specific tissues
that are associated with adverse effects. This provided another measure of the potential nature
and magnitude of effects birds and mammals may experience in the Coeur d'Alene Basin.
Fish and other aquatic organisms can also have both external and internal exposures, although
they are not typically described as separate pathways. External exposure occurs as a
consequence of living in a contaminated medium. Uptake of metals can be through the skin
(dermal), through the gills, or through the diet, including ingestion of contaminated food, water,
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and possibly sediment. Internal exposures, which provide absolute evidence of exposure, were
measured as concentrations of chemicals in tissues including whole body, muscle, kidney, and
liver. Those data were presented separately in the EcoRA because information is available that
allows the estimation of risks based on tissue concentrations.
Exposure estimates for amphibians consisted of external exposure only. These receptors are
similar to aquatic organisms in that exposure is measured using concentrations of contaminants
in abiotic media (e.g., surface water). Although amphibians are also exposed to sediment, these
exposures were not estimated because corresponding toxicity data for sediment were not
available for this receptor group. Exposure for amphibians was evaluated by considering the full
distribution of dissolved COPEC concentrations in surface water from each CSM unit and/or
watershed.
Exposures estimated for soil-associated biota (terrestrial plants, terrestrial invertebrates, and soil
microbial processes) consisted of external exposure only. These receptors are similar to aquatic
organisms and amphibians in that exposure is measured using concentrations of contaminants in
abiotic media (e.g., soil-sediment). Exposure for soil-associated biota was evaluated by
considering the full distribution of COPEC concentrations in soil-sediment from each CSM unit
and/or watershed. Exposure for soil-associated biota was only evaluated based on soil-sediment
samples from terrestrial habitat types (i.e., agricultural, riparian, and upland). Exposure
evaluations were performed separately for each terrestrial habitat type within a CSM unit and/or
watershed.
Ecological Effects Analysis
Two kinds of measures were evaluated for ecological effects: (1) measures of effects and
(2) measures of ecosystem and receptor characteristics. Measures of effects are the quantifiable
changes in an attribute of an assessment endpoint in response to a stressor. As with the measures
of exposure, the measures of effect were developed for each of the assessment endpoints and
habitats within each of the CSM units. The measures of effects also are defined according to the
potential exposure media within each of the habitats in each CSM unit. The measures of effects
are briefly stated as:
• Effects on health, survival, or reproduction of migratory birds or on special-status
animal species at the individual level
• Effects on survival, reproduction, or abundance for fish, amphibian, avian,
mammalian, or special-status plant species at the population level
• Effects on aquatic or terrestrial plant community composition, density, species
diversity, or community structure
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• Effects on aquatic or terrestrial invertebrate community composition, abundance,
density, species diversity, or community structure
The ecological effects characterization consists of an evaluation of available toxicity or other
effects information that can be used to relate the exposure estimates to a level of adverse effects.
Stressor-response (i.e., effects) data that may be used to evaluate ecological risks resulting from
chemical exposures fall into three general categories: (1) literature-derived or site-specific
single-chemical toxicity data, (2) site-specific ambient media toxicity tests, and (3) site-specific
field surveys (Suter et al. 2000). All three categories of data were available for the assessment of
ecological risks in the Coeur d'Alene Basin and are summarized below.
• Single-chemical toxicity data consist of results of toxicity tests with single
chemicals (or materials) as reported in published literature or performed on a site-
specific basis. These data may also be represented as summaries of literature
toxicity data (e.g., water quality criteria). Single-chemical toxicity data developed
for use in the Coeur d'Alene Basin EcoRA are summarized in Section 3.2 of the
EcoRA, while Appendix E of the EcoRA presents further details of the individual
studies.
• Site-specific toxicity tests have been done in the Coeur d'Alene Basin. This
testing provides important information on the toxic effects that have been
observed in site-relevant organisms exposed to site media (soil, sediment, and/or
surface water). The toxicity testing done in the Basin also is summarized in
Section 3.2 of the EcoRA for each receptor group, and Appendix E of the EcoRA
presents details for the primary studies.
• Site-specific field surveys have been conducted on most of the receptor groups.
These surveys also provide vital information concerning effects observed in the
Basin. A summary of the site-specific field surveys is presented in Section 3.2 of
the EcoRA for each receptor group, while Appendix E of the EcoRA provides
further details of primary surveys.
The relationship between the various receptor groups and ecological effects information
available for each measure of effect are shown in Figure 7.2-6. The end-product of the
ecological effects characterization is a range of toxicity reference values (TRVs) that was
combined with the exposure estimates (birds and mammals) or the EPCs (fish and other aquatic
organisms, amphibians, terrestrial plants, terrestrial invertebrates, and soil microbial process) to
estimate potential risks in the risk characterization. Measures of ecosystem and receptor
characteristics were also evaluated for their potential effects on identified receptors, including
habitat for special-status or other species. These are factors that influence the behavior and
location of ecological entities of the assessment endpoint (such as fish), the distribution of a
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stressor (such as water temperature), and the life-history characteristics of the assessment
endpoint (such as reproduction) that may affect exposure in response to the stressor. Examples
of these measures include bank stability, substrate composition and mobility, water temperature,
spatial distribution and connectivity of habitat, riparian vegetation habitat quality, sediment
deposition rate, and turbidity (total suspended solids). Evaluation of these measures was based
on results from a number of studies conducted within the Basin, primarily CSM Units 1, 2,
and 3. It focused on the relationships between mining-related hazardous substances and the
indirect effects those stressors have had on physical and biological conditions within the Basin.
7.2.6 Characterization of Ecological Risk
The risk characterization phase of the EcoRA combined the results of the exposure analysis with
those from the ecological effects analysis to determine which stressors posed risks to which
receptors (assessment endpoints).
Potential risks to the representative species were quantified for each exposure pathway for which
data were available. For single-chemical toxicity data, chemical-specific risk estimates were
derived using a combination of methods. For birds, mammals, and aquatic biota, the HQ method
was used whereby point estimates of exposure were compared to point estimates of effects.
(Note that the "point estimates" for birds and mammals are the UCL95 of the mean.) For
amphibians, terrestrial plants, soil invertebrates, and soil processes, full distributions of exposure
and effects were compared, with risk being represented by the percent overlap of the two
distributions. The magnitudes of the estimated risks for each receptor group are discussed with
other lines of evidence in the risk description section (4.2) of the EcoRA. Because receptors
were evaluated at differing levels of ecological organization (i.e., individual-, population-, and
community-level), risk estimation was based on measures of exposure and effects appropriate for
each level of ecological organization.
Risk estimates were also made based on available site-specific toxicity tests and field surveys.
These risk estimates were derived by following the decision processes outlined in Suter et al.
(2000). Results from site-specific toxicity tests were judged supportive of a conclusion of risk if
statistically significant toxicity relative to controls or dose-response relationships for exposure of
test species to site media were observed. Results from field survey data were judged supportive
of a conclusion of risk if observations differed significantly from appropriate reference
observations, or if measured parameters (such as ALAD activity of waterfowl blood) were
outside of bounds assumed to be representative for that species. Wherever possible, correlation
between observed responses in toxicity tests and field surveys with field concentrations of
COPECs was made to provide information concerning causation of observed responses. The
results of the risk estimation for each line of evidence and receptor group are presented in
Section 4.1 of the EcoRA.
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Determination of risk to receptors was performed by weight-of-evidence evaluation. The
strengths, weaknesses, and relative power of each piece of available information (i.e., line of
evidence) were considered individually and in combination to develop conclusions concerning
the presence or absence of risks. For the chemical stressors, the results were presented as tables
and graphs that show the frequency at which COPEC concentrations exceed the various potential
effect levels for the different receptors. Based on the potential risks of adverse effects to those
ecological receptors (and similarly exposed species), the EcoRA identifies the final COECs.
For physical and biological stressors, the evaluation of effects of mining-related hazardous
substances relied on comparison of assessment areas within the Basin to reference areas with
similar exposure to non-mining-related stressors (e.g., forestry, roads, development). This
process served to isolate a level of effect attributable to mining-related hazardous substances.
Several lines of evidence (i.e., measures of ecosystem and receptor characteristics) were used to
assess adverse effects on the physical and biological characteristics endpoint. Examples of these
measures include riparian habitat suitability index, streambank stability, substrate composition
and mobility, and water temperature. Analysis of these lines of evidence included field
observations and interpretation of aerial photographs to assess the spatial distribution and
connectivity within riverine and riparian habitats. Fragmentation of these habitats can affect
receptors by limiting the ability to migrate, acting as barriers to biotic interactions, and/or
increasing susceptibility to predation. The detailed evaluation of secondary effects on physical
and biological ecosystem characteristics is presented in Appendix K of the EcoRA. The results
described were considered to represent adverse effects that are secondarily related to hazardous
substances occurring within various portions of the Basin.
Uncertainties are inherent in all risk assessments, and the EcoRA (Section 4.3 of the EcoRA)
presented a discussion of various uncertainties and limitations associated with the risk
assessment process, or with the available data, that may result in under- or over-estimation of
risks. The nature and magnitude of uncertainties depend on the amount and quality of data
available, the degree of knowledge concerning site conditions, and the assumptions made to
perform the assessment.
Uncertainties associated with problem formulation include use of historical data that may not
completely meet EPA data usability criteria, inconsistent labeling of sample location types or
lack of labeling for some data, and pooling of soil and sediment data by habitat type for
terrestrial evaluations. However, despite the uncertainties described here, there is a very large
volume of chemical and biological data for the Coeur d'Alene Basin that is suitable for
evaluation of risks to ecological receptors. Data that were found to be questionable through the
general review and evaluation were not used.
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The uncertainties associated with the exposure characterization include exposure pathways not
retained for quantitative evaluation, identification of ecological receptors, selection of
representative species, exposure route assumptions, regression modeling, and speciation of
metals. Uncertainties associated with the ecological effects characterization include evaluation
of chemical toxicity (selection and use of toxicity reference values), and assumptions regarding
use of bioassay test organisms or test results, and allometric scaling factors.
Uncertainties and limitations associated with the risk characterization include use of HQs as an
indicator of potential ecological risk, lack of data for some multi-pathway risk estimates, joint
multi-chemical toxicity, lack of multiple lines of evidence for certain receptor groups, treatment
of estimated exposures that exceeded no observed adverse effect levels but not lowest observed
adverse effect levels, and use of risk estimates for representative species to characterize risks to
other plants and wildlife.
Results of the risk characterization are summarized below in the Conclusions section (7.2.9).
7.2.7 COEC Concentrations Protective of Receptors
Concentrations of COECs in environmental media (soil, sediment, and water) were identified
that preserve the desired attributes of the assessment endpoints, and below which adverse effects
are expected either to be absent or to be within defined limits of effects levels. These
concentrations are often determined by levels of contaminants that would be protective of the
most sensitive ecological receptor that is exposed to a particular medium.
These COEC concentrations need to account for the presence of special-status species and
protected migratory birds where the level of protection should be higher (i.e., the acceptable
effect threshold is lower) than that sought for population-level, community-level, or landscape-
level endpoints. This is accomplished by considering the relative sensitivity of special-status
species and migratory birds to metals compared to sensitivity of other species in their group,
selecting toxicity test endpoints that offer protection at the individual level as a basis for TRVs,
or applying a safety factor to TRVs developed using surrogate species. The availability of site-
specific information for migratory birds has allowed the selection of TRVs or exposure
parameters that reflect the protection of individuals. The availability of site-specific comparative
toxicity testing with bull trout has allowed the evaluation of the relative sensitivity of bull trout
to metals, compared to the sensitivity of other aquatic organisms.
The protective-level COEC concentrations are presented as ranges for the various receptor
groups that were evaluated (i.e., birds and mammals combined, soil biota combined, etc.),
segregated by the level of assessment (e.g., individual- or population-level) and the medium
(e.g., soil or sediment). The protective-level COEC concentrations for aquatic organisms are set
to cover the group as a whole, with consideration of possible effects on special-status species.
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Protective-level COEC concentrations for birds and mammals that were evaluated at the
individual level are based on no observed adverse effect level (NOAEL) values, whereas the
lowest observed adverse effect level (LOAEL) or dose causing effects in 20 percent of test
animals (ED20) (i.e., a less restrictive value) was used for receptors evaluated at the population
level. Because soil is not the most appropriate source medium for evaluation of risks for all
wildlife species, protective-level COEC concentrations were developed for representative species
on the basis of the habitat types in which they predominantly occur. Species that occur in
riparian, agricultural, or upland habitats were identified as "terrestrial" and protective-level
COEC concentrations were calculated for soil (Table 7.2-6). Species that occur in riverine,
lacustrine, and palustrine habitats were identified as being "aquatic" and protective-level COEC
concentrations were calculated for sediment (Table 7.2-7).
Protective-level COEC concentrations for soil-associated biota (e.g., plants, invertebrates, and
microbial processes) were based on toxicity data from the published literature and were based on
no observed effect concentrations (NOECs) and lowest observed effect concentrations (LOECs)
for each receptor group (Table 7.2-6).
Table 7.2-8 lists protective-level COEC concentrations for surface water based on the national
AWQC, adjusted for hardness for specified metals. The national chronic criteria are estimates of
the highest concentrations of materials in surface water to which an aquatic community can be
exposed indefinitely without resulting in an unacceptable effect.
EPA published an update to the AWQC for cadmium (66 FR 18935; April 12, 2001) at about the
same time as final changes were being incorporated into the EcoRA, and it was not feasible to re-
analyze risks to aquatic organisms in time to make corresponding changes in the final EcoRA.
Revised protective concentrations for cadmium are, however, shown in Table 7.2-8 and in later
sections of the ROD. In relatively soft waters of the Basin, the updated cadmium AWQC is
lower than the 1998 cadmium AWQC used in the EcoRA, and use of the 2001 criterion would
result in larger estimated cadmium risks to aquatic biota than the risks identified in the EcoRA if
the risks were recalculated.
All median values for background surface water were below the national chronic criteria AWQC
(assuming hardness of 30 mg/L as CaC03). Background values for metals are described in
EPA's Final Technical Memorandum (USEPA 2001h). The 95th percentile of the background
dissolved lead concentrations exceeded the national chronic criteria calculated at hardness of 30
mg/L as CaC03 in the following areas: the Upper South Fork, the Page-Galena mineral belt
area, and the South Fork basin as a whole ("entire South Fork"). The 75th percentile of the data
exceeded the national chronic criteria in the Page-Galena mineral belt area. These results imply
that the national criteria AWQC would only be exceeded in a very limited number of mineralized
locations in the stated drainages at some times if mining-related impacts did not exist. All of the
calculated values for zinc and cadmium, including the 95th percentile (assuming hardness of 30
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mg/L as CaC03), were well below the national criteria. Therefore, the AWQC are generally
protective for surface-water biota. However, in areas of low hardness (e.g., 10 mg/L as CaC03)
the AWQC may not be protective, particularly with respect to individuals of special-status
species such as bull trout and cutthroat trout.
Protective-level COEC concentrations for sediment are either toxicity-based or regional
background concentrations of metals in sediment in the Basin (Table 7.2-9). The higher value of
either background or the toxicity screening value is recommended as the protective-level COEC
concentration. On the basis of the determinations of regional variations in soil and sediment
upper background values (USEPA 200 lh), separate background values for sediment were
determined for CSM Units 1 and 2, CSM Units 3 and 4, and CSM Unit 5.
7.2.8 Ecological Goals for Physical and Biological Characteristics
Qualitative goals were developed for physical and biological characteristics (assessed as
measures of ecosystem and receptor characteristics, such as stream bank stability, water
temperature, etc.) that have been adversely affected by releases of mining-related hazardous
substances (Table 7.2-10). The goals for these characteristics describe either a range of
conditions found in the Coeur d'Alene Basin prior to mining activities or the range of conditions
in these characteristics currently found in selected reference areas. These ecological goals are
applicable to those CSM units that showed unacceptable risks for the specific physical
characteristic, and are considered to be the equivalent of the protective-level COEC
concentrations identified for hazardous substances (previous section).
7.2.9 Conclusions
A large volume of data regarding the impacts of mining-related hazardous substances is available
for the Coeur d'Alene Basin and, while some data gaps may exist, there is more than adequate
evidence to demonstrate the magnitude of the impacts to the ecosystem. High concentrations of
metals are pervasive in the soil, sediment, and surface water in the Basin, and these metals pose
substantial risks to the plants and animals that inhabit the Basin. The risk assessment evaluated
impacts to more than 80 different species (see Table 7.2-1). The species evaluated represent
numerous trophic levels, including hundreds of species that are similarly exposed. Species
evaluated include "special-status species," such as those listed as endangered or threatened under
the ESA, those listed by the USFWS as species of concern, state-listed sensitive plant species,
and culturally significant plant species. The National Marine Fisheries Service has indicated that
no anadromous fish species are present in the Coeur d'Alene Basin because the Grand Coulee
Dam blocks passage of anadromous fish into the Basin. Examples of the special-status species
evaluated in the EcoRA include the bald eagle, black tern, gray wolf, lynx, bull trout, Ute
ladies'-tresses, and the water potato.
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The results of the EcoRA indicate that most watersheds in which mining has occurred and a large
portion of the Basin downgradient of mining areas are ecologically degraded as a direct or
secondary effect of mining-related hazardous substances. This ecological degradation has
resulted in demonstrated, observable effects in the Basin. In addition, the results of the EcoRA
show that, if remediation is not conducted in the Basin, effects can be expected to continue for
the foreseeable future. These demonstrated effects and the future risks predicted in the EcoRA,
which are summarized below, were used as the basis for identifying remedial actions in the FS
and this ROD.
Conclusions concerning the nature and extent to which mining-related hazardous substances
present risks to ecological receptors within the Coeur d'Alene Basin were based on the weight-
of-evidence analyses. The general conclusion is that heavy metals, primarily lead and zinc,
present significant ecological risks to most ecological receptors throughout the Basin
(Table 7.2-11). Few receptors were identified for which no ecological risks are estimated. In all
receptor classes, ecological risks from at least one COEC in at least one area of the Basin were
identified. Because multiple lines of evidence were available for evaluation of risks for some
receptors in all receptor classes (except soil invertebrates and soil microbial processes), the
strength of many risk conclusions is considered to be high. Brief summaries of the available
lines of evidence and risk conclusions for each receptor class are presented below.
Birds
Conclusions for effects on birds are as follows:
• Risks to health and survival from at least one metal in at least one area were
identified for 21 of 24 avian representative species.
• No risks were identified for ospreys, bald eagles, and northern harriers in the
Lower Basin, Coeur d'Alene Lake, and Spokane River areas. Additional data
obtained after finalization of the EcoRA have identified potential risks to fish-
eating birds in the Upper Basin.
• Lead and zinc present the greatest risks to birds in the Coeur d'Alene Basin, with
risks to at least one avian receptor estimated for 11 (for lead) and 10 (for zinc) of
13 areas, that were evaluated in the Coeur d'Alene Basin. Risks from these
COECs are not only spatially widespread, but also are broadly distributed
taxonomically and of great magnitude. For example, the HQ for exposure of
spotted sandpipers to lead in Ninemile Creek was 387, based on a LOAEL for
toxic effects.
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• There is extensive documentation of lead poisoning among waterfowl due to
contaminated sediments in the Lower Basin that is not associated with hunting
(from lead shot) or fishing (from lead sinkers). Lead poisoning has been
documented in Basin waterfowl year-round in the floodplain stretching from
Smelterville to Coeur d'Alene Lake.
• Waterfowl deaths due to lead poisoning associated with the ingestion of
contaminated sediments have been reported for decades. Ninety-five percent of
available habitat in the Lower Basin has lead concentrations above the LOAEL
for waterfowl (530 mg/kg), and 80 percent has lead concentrations that are lethal
to waterfowl (greater than 1,800 mg/kg).
• In the Coeur d'Alene River basin, lead poisoning (primarily due to ingestion of
contaminated sediments) is responsible for 96 percent of the total tundra swan
mortality, compared to 20 to 30 percent (primarily due to ingestion of lead shot)
at the Pacific flyway and national level.
• Members of 12 species of migratory birds and mammals have been killed through
ingestion of lead-contaminated soils and sediments. Since 1981, a total of 27
species of wildlife have been documented with various degrees of lead exposure
that exceed background.
• The number of waterfowl carcasses found in 1997 represented the largest
documented die-off in the Coeur d'Alene River Basin since 1953. This and other
wildlife data collected over the past 20 years are supportive of the fact that lead
concentrations in soil and sediment in the Coeur d'Alene Basin still occur at toxic
levels. Therefore, animal deaths by lead poisoning from the ingestion of
contaminated soils and sediment are expected to continue.
• Risks from cadmium, copper, and mercury were spatially and taxonomically
much less broadly distributed and of lower magnitude, although they presented
risks to at least one bird receptor in 5 for cadmium, 3 for copper, and 1 for
mercury of the 13 areas.
• Arsenic did not present a risk to any avian receptor in any location in the Basin.
• Strength of risk conclusions, as determined by the abundance, quality, and
concurrence of available lines of evidence, was high for eight avian species
(Canada goose, tundra swan, wood duck, mallard, osprey, bald eagle, northern
harrier, and great horned owl), moderate for five (American kestrel, spotted
sandpiper, American dipper, American robin, and song sparrow), and low for
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eleven species (great blue heron, lesser scaup, common goldeneye, common
merganser, ruffed grouse, wild turkey, common snipe, black tern, belted
kingfisher, tree swallow, and Swainson's thrush).
Mammals
Conclusions for mammals are as follows:
• Risks to health and survival from at least one COEC in at least one area were
identified for 12 of 18 mammalian receptor species.
• No risks were identified for fisher, wolverine, river otter, gray wolf, lynx, or
beaver.
• No single COEC stands out as a predominant risk driver for mammals. Zinc,
lead, and arsenic were the most common risk drivers, presenting risks within at
least one CSM unit or segment in the Coeur d'Alene Basin for 9 of 18 receptors
for zinc, 8 of 18 receptors for lead, and 7 of 18 receptors for arsenic. For
example, HQs of 20 or higher were found for zinc for the masked shrew and long-
legged myotis in Canyon Creek watershed, and the HQ for arsenic was 4.4 for
muskrats in CSM Unit 3.
• Cadmium, copper, and mercury presented risks within at least one CSM unit or
segment in the Coeur d'Alene Basin to 2, 4, and 3 species, respectively. Only in
CSM Unit 3 did any COEC (zinc) present a risk to 50 percent or more of all
mammalian receptors. Arsenic, cadmium, copper, and mercury did not present a
risk to more than 25 percent of receptors in any area.
• Spatially, risks from zinc were most widespread (9 of the 13 areas) and copper the
least widespread. Lead, cadmium, arsenic, and mercury posed risks in 8, 6, 5, and
5 areas, respectively.
• With the exception of receptors for which no risks were identified, the strength of
risk conclusions, as determined by the abundance, quality, and concurrence of
available lines of evidence, was generally low for most mammalian receptors.
This is because few lines of evidence were available for most mammals and,
when multiple lines of evidence were available, there was generally little
concurrence. Conversely, given the generally conservative nature of the exposure
models, risk conclusions for receptors estimated not to be at risk (fisher,
wolverine, river otter, gray wolf, lynx, and beaver) are considered strong.
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Fish and Other Aquatic Organisms
Review of the available evidence of risks to aquatic receptors (fish, invertebrates, and plants)
leads to the following conclusions:
• Approximately 20 miles of the South Fork and 13 miles of tributaries are unable
to sustain reproducing fish populations. Species density and diversity are reduced
throughout the Basin, and the Ninemile and Canyon Creeks are essentially devoid
of fish and other aquatic life in the area of mining impacts. Impacted species
include the native bull trout, which is listed as "threatened" under the ESA.
• Some fish species (e.g., sculpins) are absent from areas of high metals
concentrations.
• Exposure of aquatic organisms to metals was confirmed by the presence of
elevated concentrations of metals in the tissues of fish, invertebrates, and plants in
many portions of the Basin.
• Based upon comparison of metals concentrations to acute AWQC, surface waters
are commonly lethal to some aquatic life in the following areas: upper Beaver
Creek, Big Creek, Canyon Creek, Ninemile Creek Segments 2 and 4, Pine Creek
Segments 1 and 3, Prichard Creek Segments 1 and 2, the entire South Fork Coeur
d'Alene River, and the Coeur d'Alene River down to Harrison (see Figures 7.2-1
through 7.2-5 for stream and segment locations). For example, HQs for acute
zinc exposure exceed 10 in more than 90 percent of the water samples from lower
Canyon Creek and from lower Ninemile Creek. In addition, acute cadmium and
lead HQs also are commonly greater than 10 in those areas.
• Toxicity testing using water from heavily contaminated portions of Canyon Creek
and the South Fork indicated that substantial dilution with clean water (10-fold or
more) is required to eliminate acute toxicity, consistent with the findings of the
surface water-to-AWQC comparisons listed above.
• Based upon comparison of metals concentrations in surface waters to chronic
AWQC, growth and reproduction of surviving aquatic life would be substantially
reduced in the following areas: Big Creek; Canyon Creek Segments 3, 4, and 5;
Ninemile Creek Segments 2 and 4; Pine Creek Segment 1; Prichard Creek
Segments 1 and 2; the entire South Fork Coeur d'Alene River; and the Coeur
d'Alene River down to Harrison.
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• Site-specific toxicity testing and/or biological surveys indicate lethal effects of
waters or reduced populations of aquatic life in lower Canyon Creek, lower
Ninemile Creek, and the South Fork from Canyon Creek to Enaville.
• Because the bull trout and westslope cutthroat trout are evaluated on an individual
level due to ESA coverage, and toxicity for some individuals can occur at levels
below the AWQC, there may be areas where the AWQC is not protective of these
species. This is particularly true in areas where there may be low hardness.
• Concentrations of metals in water exceed chronic AWQC by some amount in
virtually all areas assessed that are downstream of sources of mining waste,
indicating some adverse effects on growth and reproduction of aquatic life in all
areas.
• Biological surveys in the Spokane River have suggested that metals toxicity
contributes to high mortality rates of trout.
• Toxic effects of contaminated sediment are believed to contribute to adverse
effects on aquatic life in Big Creek Segment 4, Canyon Creek, Ninemile Creek,
Pine Creek, Prichard Creek Segment 3, the entire South Fork, the Coeur d'Alene
River, the Spokane River, and, possibly, some parts of Coeur d'Alene Lake.
• Physical disturbances caused by land alterations, and modifications of stream
channels caused by construction of infrastructure, adversely affect the ability of
streams to support aquatic organisms in some portions of the Coeur d'Alene
Basin. Those factors were considered, in part, by using reference areas as a
comparison when evaluating biological surveys and habitat conditions.
• The strength of risk conclusions, as determined by exceedances of criteria, site-
specific toxicity tests, and biological surveys, is moderate to high in many CSM
units and segments.
Amphibians
Conclusions for amphibians are as follows:
• Risks to health and survival from heavy metals are present for three of the four
amphibian species evaluated.
• Available lines of evidence suggest that COPECs in the Coeur d'Alene Basin do
not present a significant risk to long-toed salamanders.
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• Cadmium, lead and/or zinc present risks to both Idaho giant salamanders and
Coeur d'Alene salamanders throughout CSM Unit 1 (except for Big, Moon, and
Prichard Creeks and the Upper South Fork) and CSM Unit 2. These salamander
species do not occur in CSM Units 3, 4, or 5.
• Cadmium, lead and/or zinc present risks to spotted frogs in CSM Units 1 and 2.
No risks were identified for the spotted frogs in CSM Unit 3 and they do not
occur in CSM Units 4 or 5.
The strength of risk conclusions, as determined by the abundance, quality, and concurrence of
available lines of evidence, is considered moderate for spotted frogs, Idaho giant salamanders,
and Coeur d'Alene salamanders; and high for long-toed salamanders.
Risks to health and survival from heavy metals are present for three of four species. Cadmium,
lead, or zinc (singly or in combination) present risks to spotted frogs, Idaho giant salamanders,
and Coeur d'Alene salamanders throughout most of CSM Unit 1 (except for Big, Moon, and
Prichard creeks, and the Upper South Fork), and in CSM Unit 2. These salamander species do
not occur in CSM Units 3, 4, or 5; no risks were identified for the frogs in CSM Unit 3. More
than 10 percent of the measured concentrations of dissolved cadmium or zinc in the CSM Unit 1
and 2 watersheds exceeded the LOEC for amphibian embryos. In addition, there was more than
10 percent overlap in the range of soil-sediment concentrations of COPECs and the LOEC,
indicating that toxic effects are likely to occur.
The strength of risk conclusions, as determined by the abundance, quality, and concurrence of
available lines of evidence, is considered moderate for spotted frogs, Idaho giant salamanders,
and Coeur d'Alene salamanders; and high for long-toed salamanders.
Terrestrial Plants
Review of available evidence of risks for plants leads to these conclusions:
• Available information suggests that exposure to arsenic, cadmium, copper, lead,
and/or zinc in CSM Units 1, 2, 3, 4, and 5 may present significant risks to
populations of selected plant receptors and to the plant community in general.
More than 20 percent of the measured COPEC concentrations in soil exceeded
ecological effects levels for plants in many areas, and biological surveys
documented adverse effects on vegetation in some of those same areas.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-40
• The strength of risk conclusions, as determined by the abundance, quality, and
concurrence of available lines of evidence, is considered moderate for Ute ladies'-
tresses, Cottonwood, willow, and Rocky Mountain maple; low for porcupine
sedge and prairie cordgrass; and high for the plant community.
Soil Invertebrates
Conclusions for soil invertebrates are as follows:
• Arsenic, cadmium, copper, lead, and/or zinc present risks to the soil invertebrate
community in CSM Units 1, 2, 3, and 5. More than 20 percent of the measured
COPEC concentrations in soil exceeded ecological effects levels for soil
invertebrates in many areas.
• The strength of risk conclusions, as determined by the abundance, quality, and
concurrence of available lines of evidence, is considered low because only a
single line of evidence was available.
Soil Processes
Conclusions for risks to soil processes are as follows:
• Arsenic, cadmium, copper, lead, and/or zinc present risks to soil processes in
CSM Units 1, 2, and 3. More than 20 percent of the measured COPEC
concentrations in soil exceeded ecological effects levels for soil processes in
many areas.
• The strength of risk conclusions, as determined by the abundance, quality, and
concurrence of available lines of evidence, is considered low because only a
single line of evidence was available.
Physical and Biological Characteristics
Risks to plants and animals also are associated with physical and biological characteristics
evaluated in this assessment. Increased bank instability, changes in stream substrate composition
and mobility, increased water temperature (from the loss of riparian vegetation along streams),
and habitat fragmentation pose a risk to aquatic organisms in affected riverine habitat of the
South Fork and its tributaries (Table 7.2-12). Elevated levels of suspended solids pose a risk to
aquatic organisms in the Coeur d'Alene River. Increased sediment deposition rates pose risks to
aquatic organisms in affected portions of Coeur d'Alene Lake. Decreased spatial distribution
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-41
and connectivity of riparian habitat, and habitat suitability, pose risks to wildlife using the
affected riparian habitat on the South Fork and its tributaries.
Selection of Remedial Action
The remedial action selected in this ROD is necessary to protect the public health or welfare or
the environment from actual or threatened releases of hazardous substances into the
environment. Such a release or threat of release may present an imminent and substantial
endangerment to public health, welfare, or the environment.
-------
Sport Fishing 1%
Public Beaches 15%
Upland Parks 6%
Waste Piles 5%
i
Neighborhood 5%
51% Home
Homegrown
Vegetables 18%
NOTE: Percentages are for a hypothetical average child,
~ and exposures for individual children would be
~ determined by the characteristics of their yard
~ and that child's activities. Data were compiled
~ from the Human Health Risk Assessment,
~ IDHW2001.
W
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 7.1-1
Average Child's Basin-Wide Lead Exposure
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-43
Figure 7.1-2
Total RME Noncancer Hazard - Modern and Traditional Subsistence Exposure Scenarios, All
Chemicals (Child Age 0 to 6 Years)
~ Surface Soil
~ Sediment
Undisturbed Surface Water
EB Disturbed Surface Water
Modern
Traditional
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-44
Figure 7.1-3
Total RME Noncancer Hazard - Modern and Traditional Subsistence Exposure Scenarios, All
Chemicals (Adult/Child)
30 i
25
20
T3 15
(5
N
(5
X
10
5
1
0 -
Modern Traditional
~ Fish
~ Water Potatoes
H Surface Soil
0 Sediment
EB Undisturbed Surface Water
ED Disturbed Surface Water
¦ Total
Note: The fish ingestion pathway was evaluated for the Adult only receptor age group, all other pathways were evaluated for the combined
Adult/Child receptor age group.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-45
0.1
0.01
(/)
0)
o
c
TO
o
0.001
0.0001
0.00001
Figure 7.1-4
Total RME Cancer Risk - Modern and Traditional Subsistence Exposure Scenarios
(Adult/Child)
~ Surface Soil
~ Sediment
S Undisturbed Surface Water
M Disturbed Surface Water
Modern
Traditional
-------
Duthie
PrichCrkSeg03
PrichCrkSeg02
PrichCrk
Seg01
Pricha
Murray
~
MidGradSeg03
oonCrk
Seg01
BvrCrkSegOl
Enavill
CataUl/. K,ngst
NM
Seg01
MidGrad
Seg04
Pinehur^t MidgradSeg02 Kellogg
Wardner
~
Seg03 ^
Bunn r Gem
Burke CCSegOl
CCSeg02
LCDRSegOl
PineCrk
Sed03
CCSeg04
CSM UNIT 1
BigCrk
Seg04
ilverton
MIDGradSeg
M UNIT 1
BigCrkSeg03
Larson
Wallace
UpperSFCDRSegOl
PineCrkSeg02
PineCrkSegOl
BigCrkSegOl
Figure 7.2-1
CSM Unit 1 Boundaries
~
~
LEGEND
City
CSM Unit Boundary for FS
Bunker Hill Superfund Site Boundary
Interstate 90
Lakes and Rivers
Segment Boundary
Washington
Location Map
NOTES
1) Base map coverages obtained
from the Coeur d* Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management
SCALE 1:170,000
0
4 Miles
N
+
027-RI-C0-102Q
Coeur tf Alene Basin RI/FS
RECORD OF DECISION
Document Control Numbers:
URS DCN: 4162500.07099.05 a
EPA No. 2.9
CH2M HILL DCN: WKP0032
Generation 1
n:\Projects\RI_FS\csm_urifts11-16 050102apr
V: CSM1 "
E: 1
LCSM1
3/18/02
&EBV
REGION 10
This map is based on Idaho
State Plane Cooidinates West Zone,
North American Datum 1983.
Date of Plot: August 14,2002
-------
CS;v IhiiT
Duthie
~
\ \
\ \
/
CiEai
*
MidGradSeg03
PrichCrkSeg03
Murray
PrichCrkSeg02
f ¦/
CSM UNIT 2
MoonCrk
Seg01
/"
PrichCrk
BvrCrkSegOl
LMn ¦-
jVKin
MidGradSeg04
\
X
MidgradSeg02
jnehurst\ ^
1
bnelterville ~ .
3 ~
-koInhb
^ineCrkSAotm^
Wardner
~
MoonCrkSeg02
6 /
NMSeg02
NMSegOl
"¦ CCSeg03
f
PineCrkSeg02
BigCrkSeg03
rkSegol
tefv UNIT 1
CCSegOl
Gen
CCSeg02
BigCrkSeg04
Osbum
MIDGradSegOl
CCSeg04
Silverton
CSM UNIT 2
Mullan,
Larson
UpperSFCDRSegOl
BigCrkSegOl BigCrkSeg02
C> . , /
? o i
O
Figure 7.2-2
CSM Unit 2 Boundaries
LEGEND
City
CSM Unit Boundary for FS
Bunker Hill Superfund Site Boundary
Interstate 90
I I Lakes and Rivers
I I Segment Boundary
Washington
Location Map
NOTES
1) Base map coverages obtained
from the Coeur d" Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management
SCALE 1:170,000
4 Miles
N
.+
027-RI-CO-102Q
Coeur cf Alene Basin RI/FS
RECORD OF DECISION
&ERA
REGION 10
Document Control Numbers:
URSG DCS: 4162500.07099.05.8
EPA No. 2.9
CH2M HILL DCN: WKP0032
Generation 1
n:\Projeds\RLFS\csm unrts11-16 050102.apr
V:VCSM2 "
E: 2
LLCSM2
05/01/02
This map is based on Idaho
State Plane Coordinates West Zone,
North American Datum 1983.
Date of Plot: August 14,2002
-------
* */>%•
jjjpssss
LCDRSeg03
CSM UNIT 3
LCDRSeg05
/$>•*
Conkling Park '
CQALakeSegOl
Figure 7.2-3
CSM Unit 3 Boundaries
CSM UNI1
EnayHfe
LCDRSeg02
MidGradSeg04
LCDRSegOl
PineCrkSeg02
LEGEND
* City
~ CSM Unit Boundary for FS
/\/ Interstate 90
I I Lakes and Rivers
I I Segment Boundary
Washington
Location Map
1)
NOTES
Base map coverages obtained
from the Coeur d' Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management.
SCALE 1:140,000
0 2 Miles
N
+
027-RI-C0-102Q
Coeur cf Alene Basin RI/FS
RECORD OF DECISION
&ERA
REGION 10
Document Control Numbers:
URSG DON: 4162500.07099.05ji
EPA No. 2.9
CH2M HIU. DCN: WKP0032
Generation 1
n:\Prqject$\RI_FS\csm_unlt8l1-16 050102.apr
V: VCSM3
E:3
LLCSM3
05/01/2002
This map is based on Idaho
State Plane Coordinates West Zone,
North American Datum 1983.
Date of Plot: May 01,2002
-------
Figure 7.2-4
CSM Unit 4 Boundaries
LEGEND
/V Stream
Road
Interstate 90
* City
Coeur d'Alene Lake Watershed
River Segment
I 1 Lake/River
Idaho
d'Alene
Location Map
NOTES
1) Base map coverages obtained
from the Coeur d'Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management.
SCALE 1:72,000
0.5 Miles
027-RI-C0-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
5ERA
REGION 10
Document Control 4162500.07099.05^
EPA No. 2.9
Generationl
AMects\watersheds\
t4_h2oShed_8-2W)0 050102.apr
VCDAtake
E:C0Alake
This map is based on Idaho
State Plane Coordinates West Zone
North American Datum 1983.
Date of Plot; September 4,2002
L: F^Part 3 8.0-1
-------
Figure 7.2-5
CSM Unit 5 Boundaries
O
I—
0
z
1
CO
<
o
X
<
Q
SpokaneRSeg03
Long. Lake Dam
t:SM UNIT 5
- » * S ' . '
iline Mile Dam ^Fairwood
SpokaneRSegOZ '
Monroe Street I
~ Country Homes
Tjpwn and Country
5pokaneUpriver
Mauser
SpokaneRSegOl
Post Falls
Trentwood
rooa
if Otis Orcharas-I
. ~. „ Post Falls uam
Plebsant View
Upper Falls Dam opportunity VeradaE®" Acres*L,bjrt* Lake
y *
CSM UNIT 4
CDALakeSeg02
Bellgrove
J
Rockford Bay
~
'Setters
•-a*,
~
~
LEGEND
City
CSM Unit Boundary for FS
Interstate 90
Lakes and Rivers
Segment Boundary
Washington
Location Map
NOTES
1) Base map coverages obtained
from the Coeur d' Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management
SCALE 1: 400,000
0 5 Miles
N
+
027-RI-CO-102Q
Coeur tf Alene Basin RI/FS
RECORD OF DECISION
SERA
REGION 10
Document Control Numbere:
URSG DCN: 4162500.07099.05.3 TKIc . . , „„ ...
EPA No 2.9 map is based on Idaho
CH2M hill DCN: WKP0032 State Plane Coordinates West Zone,
Generation 1 North American Datum 1983.
n:\Proiecls\RLFS\csm_units11-16_050102.apr
P"5 Date of Plot: May 01,2002
L: Part 3 Fig 1.0-6
05/01/02
-------
Analysis
Exposure Characterization
1
Receptors
Ecological Effects Characterization
Effects Measures
Fish and Other
Aquatic Organisms
Primarily
Salmonlds and Waterfowl
Invertebrates
:y Frogs
Only
Amphibians
Multiple
Species
Terrestrial Plants
Oral Dosages and
Tissue
Concentrations .
Media and Tissue
Concentrations
* Media
Concentrations
Only
Terrestrial Invertebrates
and Soil Processes
Site-specific
Field Surveys
Literature-derived
Single-chemical
Toxicity Data
Site-specific Toxicity
Tests with Ambient
Media
SEPA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 7.2-6
Ecological Effects Characterization
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-58
Table 7.1-1
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Current/Future Residential Exposure Scenario
Scenario Timeframe: Current/Future
Aiv;i
l!\|)iisuiv Pninl'1
ill' Co mi- rn
CiiiHi'iilnilii
Mill
n Dikikd
M:i\
I nils
l-'iv(|ik'iii'\ ill'
IK'k'i'liiui
l;.\|)IIMIIV Pllilll
CiiiHviilniliiiii
l!\|)iisiiiv Piiim
CiiiHi'iilniliiin
I nils
Sl;ilislk;il Mi-iisuiv1'
Lower Basin
l'\|)osuii' M<.'(1 inm: Soil
Yard Soil - Direct Contact
arsenic
4.3
115
mg/kg
28/28
48.53
mg/kg
95% UCL
iron
9,710
93,000
mg/kg
25/25
37,703
mg/kg
95% UCL
lead
15
7,350
mg/kg
160/160
110
mg/kg
geometric mean
House Dust - Direct Contact
lead
49
3.140
nm/ksi
31/31
301
nm/ksi
ueometric mean
Upper Basin0
l'\|)osuiv Mi-riiiim: Soil
Yard Soil - Direct Contact
arsenic
2.9-6.9
66.1-1150
mg/kg
53 53
308/309
21.46-50.74
mg/kg
95% UCL
iron
5,910-13,000
46,700 -
123,000
mg/kg
54/54 -
282/282
20,198-27,190
mg/kg
95% UCL
lead
22-94
3,356-
20,218
mg/kg
70/70 -
262/262
257-771
mg/kg
geometric mean
House Dust - Direct Contact
lead
23 - 429
1,750-
29,725
mg/kg
26/26 - 35/35
466- 1,004
mg/kg
geometric mean
r.\|)osuiv M id in in: (.niiiii(l\\;ik'r (ouiivnlniliiins ivpivsuil lukil mi-liils in xkiUt)
Tap Water - Ingestion | arsenic | 0.19 | 9.2 | ug/L | 11/16 | 8.4'1 | mg/kg | Max
All Areas
l.\|>osiiiY Mi-dium: Phinl Tissue
Homegrown Vegetables -
Ingestion
cadmium
0 02
1.85
mg/kg
0.319
mg/kg
95% UCL
lead
0.48
48.6
mg/kg
24/24
7.8
mg/kg
arithmetic mean
Notes:
Min - minimum
Max - maximum
Exposure Point Concentration: Estimate of the average concentration a person would encounter at the location where the exposure occurs.
Statistical Measure: The statistical measure describes how the exposure point concentration was calculated from the data.
95% UCL: 95 percent upper confidence limit of the mean
aThe exposure point concentration for lead in house dust that was used in the lead model is the geometric mean of vacuum bag data.
bThe exposure point concentration for lead in yard soil that was used in the Lead Model is the geometric mean.
cThe Upper Basin was divided into seven sub-areas, the ranges of values presented for the Upper Basin represent the ranges of the seven sub-areas.
dThis concentration is the average of static (first-draw water) and purged (flushed line water) samples.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-59
Table 7.1-2
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Current/Future Neighborhood Recreational Exposure Scenario
Scenario Timeframe: Current/Future
(>cn^r;i|)hk';il
AiVii
(hcniiciil of
I'1\|)omiiv Point 1 Concern
('niKTiilmlinn
IKMcclod
Min M;i\
I'1\|)osiiiv Point
l m|iK'iio ol' I xposniT Point (oneenlnilion S(iilis(ic;il
I nils 1 Deled ion 1 (oneenliiilion1 1 I nils 1 Men sine
1 pper' liasiii
r.xpoMiiv Medium: Soil/Sediment
Neighborhood Stream
Sediments - Direct
Contact
lead
88
67,100
mu ku
17/17
29,500
mg/kg
95th percentile
I'1\|)omiiv Medium: Sniinee \\ ;Kcr (eoneenli nlions ;irc lolnl nieliils)
Surface Water - Direct
Contact
lead
0.3
1,650
Hg/L
79/80
296
Hg/L
95th percentile
I'1\|)omiiv Medium: Soil
Waste Piles - Direct
Contact
lead
83
63,700
mg/kg
27/27
49,800
mg/kg
95th percentile
Notes:
Min - minimum
Max - maximum
Exposure Point Concentration: Estimate of the average concentration a person would encounter at the location where the exposure occurs.
Statistical Measure: The statistical measure describes how the exposure point concentration was calculated from the data.
"Not used directly in the lead model, used to assess incremental increases in blood lead over residential blood lead levels.
bConcentrations only exceeded for the Burke/Ninemile sub-area of the Upper Basin.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-60
Table 7.1-3
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Current/Future Public Recreational Exposure Scenario
Scenario Timeframe: Current/Future
( onconl ml ion IK'kckd
I'1\|)osiiiv I'oinl
(ico^i'iiphiciil
ClH'ink'iil of
I- IV(|IK'IIO
Kxposmv I'oinl
Concentration
Sliiiisliciil
Aiv.i
l'l\|)OSIIIV Point
Concern
Min
Msix
I nils
of IH'K'Clion
Conconlriilion
I nils
Measure
Lower Basin
Medium: SoiI/Sodimoiil
Floodplain Soil/Sediment near
arsenic
2
492
mg/kg
388/388
119
mg/kg
95% UCL
the Lower CDAR - Direct
iron
4,450
256,000
mg/kg
388/388
105,451
mg/kg
95% UCL
Contact
manganese
92
26,400
mg/kg
388/388
9,886
mg/kg
95% UCL
lead
15
29,200
muku
388/388
5,750a
mg/kg
95th Percentile
.Medium: Surl'sicc \\ siut (concenIr;i(ions ;ii
c loliil iiKMiils in wiilcr)
Disturbed Surface Water -
lead
11"
S 1,5(1(1
ii- 1.
122. i::
31, "(in
Hg/L
''5lli Percentile
Direct Contact
Upper Basin
Mod in in: Soil/Sediment
Surface Soil and beach
arsenic
73
266
uiu ku
l<> l<>
163
mg/kg
95% ILL
sediments near confluence of
iron
39,900
174,000
mg/kg
19/19
100,621
mg/kg
95% UCL
North and South Forks CDAR
Direct Contact (only location
manganese
3,000
14,800
mg/kg
19/19
8,585
mg/kg
95% UCL
exceeding)
Notes:
CDAR - Coeur d'Alene River
Min - minimum
Max - maximum
Exposure Point Concentration: Estimate of the average concentration a person would encounter at the location where the exposure occurs.
Statistical Measure: The statistical measure describes how the exposure point concentration was calculated from the data.
95% UCL: 95 percent upper confidence limit of the mean
aNot used directly in the lead model. This value is the 95th percentile for sediment only, used in the lead evaluation to estimate incremental increases in children's blood lead in
combination with lead in Lower Basin soils and disturbed surface water samples.
'Not used directly in the lead model. Used to assess incremental increases in blood lead in combination with lead in Lower Basin soils and sediment.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-61
Table 7.1-4
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Future Residential Use of Tap Water
Scenario Timeframe: Future
Medium: Groundwater
Exposure Medium: Groundwater
loliil Mcliil
I'1\|)omiiy Point
( hciniciil of
(oihtiiI union Dclcck'd
l'lT(|IK'IIC\ of K\|)OSIIIV Poillt
( oniTiili'iilion
Sliiiisliciil
l-lxposinv Point
( oncern
Min
Msi\
I nils
Ik'kTlion
( oniTiilr;ilion
I nils
Mc;isiiro
Nine Mile
Tap Water - Ingestion
Cadmium
0.1
996
Hg/L
70/80
130.85
mg/kg
95% UCL
Zinc
2.8
145,000
Hg/L
79/80
19,756
mg/kg
95% UCL
Notes:
Min - minimum
Max - maximum
Exposure Point Concentration: Estimate of the average concentration a person would encounter at the location where the exposure occurs.
Statistical Measure: The statistical measure describes how the exposure point concentration was calculated from the data.
95% UCL: 95 percent upper confidence limit of the mean
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-62
Table 7.1-5
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Future Subsistence Scenario in the Lower Basin
( oueeiili'iilioii
Mxposure Point
( hemie;il of
Deleeled
l"re(|iiene\ of
I'ApoMire Point
(oneentintion
l'l\|)OMIIV PoilK
('niieeru
Mill
Msi\
I nils
Delect ion
('niieeiili'iilinn
I nils
Sliiiislieiil Mensure
.Medium: Soil
Floodplain Surface Soil - Direct Contact
Antimony
1.2
58.6
mg/kg
142/155
21.16
mg/kg
95% UCL
Arsenic
5.4
492
mg/kg
155/155
124.44
mg/kg
95% UCL
Cadmium
0.21
86.4
mg/kg
155/155
30.45
mg/kg
95% UCL
Iron
12,700
222,000
mg/kg
155/155
97,440
mg/kg
95% UCL
Manganese
511
25,200
mg/kg
155/155
8,960
mg/kg
95% UCL
Lead
15.3
7,250
mg ku
155/155
4,900
mg/kg
95th Percentile
Medium: Sediment
Floodplain Sediment - Direct Contact
Antimony
1
73.7
mg/kg
211/233
25.2
mg/kg
95% UCL
Arsenic
1.5
375
mg/kg
233/233
120.96
mg/kg
95% UCL
Cadmium
0.24
105
mg/kg
228/233
39.33
mg/kg
95% UCL
Iron
4,450
256,000
mg/kg
233/233
113,073
mg/kg
95% UCL
Manganese
92.3
26,400
mg/kg
233/233
10,700
mg/kg
95% UCL
Lead
18.3
29,200
mg/kg
233/233
5,750
mg/kg
95th Percentile
Medium: Phinl Tissue
Water Potatoes (\\ uli skin; - Ingestion
Cadmium
(MX."
3.71
mg/kg
88/95
0.489
mg/kg
95% UCL
Lead
0.33
127
mg/kg
95/95
94
mg/kg
95th Percentile
Water Potatoes (without skin) - Ingestion
Lead
0.25
1.98
mg/kg
93/93
0.53
mg/kg
95th Percentile
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-63
Table 7.1-5 (Continued)
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Future Subsistence Scenario in the Lower Basin
( oncenlriilion
Kxposurc Point
( hemiciil of
Dclcclcd
l"rc(|iicnc\ of
l-Aposurc Point
(oncenlriilion
I'ApoSIII'C PoilK
Concern
Min
Msix
I nils
Deled ion
(oncenlr;i(ion
I nils
Sliiiisliciil Mensure
Medium: SuiTiicc Wilier
Undisturbed Surface Water at Lower
Arsenic
7
20
Hg/L
4/9
20
Hg/L
Max
CDAR - Direct Contact
Lead
2
430
Hg/L
91/93
110
Hg/L
95th Percentile
.Medium: \nim;il Tissue
Species
Fish Fillets from
CdA Lateral Lakes -
Ingestion
Northern Pike
Methylmercury
0.025
0.48
mg/kg
63/63
0.133
mg/kg
95% UCL
Bullhead
Lead
0.03
0.69
mg/kg
126/126
0.1
mg/kg
geometric mean
Northern Pike
Lead
0.03
0.15
mg/kg
63/63
0.03
mg/kg
geometric mean
Perch
Lead
0.09
2.41
mg/kg
123/123
0.34
mg/kg
geometric mean
Notes:
Min - minimum
Max - maximum
CdA - Coeur d'Alene
Exposure Point Concentration: Estimate of the average concentration a person would encounter at the location where the exposure occurs.
Statistical Measure: The statistical measure describes how the exposure point concentration was calculated from the data.
95% UCL: 95 percent upper confidence limit of the mean.
"The exposure point concentrations for lead were not used in the Lead Model, but rather were used to calculate potential lead intake rates. These rates were compared
to residential intakes derived from the Lead Model. Various concentrations were compared to the residential intakes, the highest values are presented in this table.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-64
Table 7.1-6
Selection of Exposure Pathways
Baseline Risk Assessment, Harrison to Mullan
Scenario
1 iiiK'fr;iiiK'
Medium
l'l\|)OMIIV
Medium
I'ApONII IV
Point
Km*|)lor
Population
Km'plor
\»e
l'l\pOMIIV
Koulo
Oii-Siic/
orr-siu-
Tj pe of
An;il\sis
Kiilioiiidc I'or Soled ion or Kxclusion
of l-'.\posurc P;i(h\\;i\
C urreiil
Tailing
Deposits and
Slag Piles
(Soil)
Surface Water
Stream and Ri\ or
Water
Reaealioiial
Cliild Adult
IllgCbllOll
Dermal
NA
NA
Quant.
Quant.
Cluldien adulb nia\ be in direct contact
with surface water during intermittent
recreational activities; therefore, the
ingestion and dermal pathways were be
quantitatively evaluated.
Stream and River
Sediment
Recreational
Child/Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
Children/adults may be in contact with
impacted sediments during intermittent
recreational / tribal activities (e.g.,
swimming and beach play).
Native Plants *
Subsistence
Child/Adult
Ingestion
NA
Quant.
Water potatoes growing in surface
water/sediments were evaluated as a
surrogate for other food plants for which
there was insufficient data.
Cattle" *
Residential
Child/Adult
Ingestion
NA
Qual.
Children and adults eat potentially affected
cattle that graze on grasses growing in
impacted sediment.
Wild Fowl" *
Recreational
Child/Adult
Ingestion
NA
Qual.
Children and adults hunt and eat potentially
affected wild fowl that are found in
floodplain.
Fish from lower
CdA River0
Recreational
Child/Adult
Ingestion
NA
Quant.
Children and adults may collect fish that
are potentially affected by impacted surface
water and sediments; therefore, this
pathway will be quantitatively evaluated.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-65
Table 7.1-6 (Continued)
Selection of Exposure Pathways
Baseline Risk Assessment, Harrison to Mullan
Scenario
l'l\|)OMIIV
l'l\|)OMIIV
Km*|)lor
Km'plor
l'l\pOMIIV
Oii-Siic/
Tj pe of
Kiiliniiiilc I'or Selection or I-'\clusion
1 iiiK'fr;iiiK'
Medium
Medium
Point
Population
\»e
Koulo
orr-siu-
An;il\sis
of l-'.\posurc P;i(h\\;i\
C urreni
Surface Soil
Surface Soil
KeiideiUial
Child Adult
Ingestion
v\
Quani.
Children and adulb nia\ poleiuialh be in
(continued)
Recreational
Dermal
NA
Quant.
direct contact with impacted surface soils
during outdoor activities at their homes
and/or parks; therefore, the ingestion and
dermal pathways will be quantitatively
evaluated.
Vegetables *
Residential
Child/Adult
Ingestion
NA
Quant.
Children and adults eat vegetables from
Native Plants'5*
Subsistence
Child/Adult
Ingestion
NA
Qual.
gardens potentially containing impacted
soils; therefore, this pathway will be
evaluated quantitatively. Susistence
populations may collect native plants
growing in impacted soils.
Game8 *
Subsistence
Child/Adult
Ingestion
NA
Qual.
Game animals (e.g., deer, beaver, and
muskrats), except for water fowl, are
unlikely to contain significant levels of
metals, see text.
Groundwater1
Tap Water
Residential
Child/Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
Residents currently use groundwater for
drinking and for household activities;
therefore, this pathway will be
quantitatively evaluated if elevated
concentrations are observed.
Air
Resuspended
Particulates from
Surface Soils
Residential
Recreational
Child/Adult
Inhalation
NA
Qual.
The inhalation pathway is likely negligible
at the site as compared to the ingestion and
dermal contact pathways for soil, except air
exposures were quantified for lead.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-66
Table 7.1-6 (Continued)
Selection of Exposure Pathways
Baseline Risk Assessment, Harrison to Mullan
Scenario
1 iiiK'fr;iiiK'
Medium
l'l\|)OMIIV
Medium
l'l\|)OMIIV
Point
Km*|)lor
Population
Km'plor
\»e
l'l\pOSIIIV
Koulo
Oii-Siic/
orr-siu-
Tj pe of
An;il\sis
Kiiliniiiilc lor Solccliou or I'.xclusion
ol° r.\|)osiirc
Tulure
Tailing
Deposits Slag
Piles (Soil)
Grouiidw aler.
Surface Soil
Subsurface Soil
KvMdeuiial
Child. Adult
IllgCbUOll
Dermal
\A
NA
Qual.
Qual.
If affecled boilb below ground surface
remain undisturbed, exposures are not
likely to occur. Residential subsurface soil
disturbance is likely minimal. Where there
are risks to residents from surface soil,
subsurface soil is also considered a risk and
will be remediated.
Occupational
Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
If affected soils below ground surface
remain undisturbed, occupational exposures
are likely to be minimal. The occupational
exposure pathway under a future, short-
term construction scenario with intensive
soil contact was quantitatively addressed.
Inhalation
NA
Quant.
Surface Water3
Stream and River
Water
Subsistence
Recreational
Child/Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
Children and adults may be in direct
contact with surface water during
intermittent recreational activities;
therefore, the ingestion and dermal
pathways will be quantitatively evaluated.
Stream and River
Sediment
Subsistence
Recreational
Child/Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
Children/adults may be in contact with
impacted sediments during intermittent
recreational / tribal activities (e.g.,
swimming and beach play).
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-67
Table 7.1-6 (Continued)
Selection of Exposure Pathways
Baseline Risk Assessment, Harrison to Mullan
Scenario
1 iiiK'fr;iiiK'
Medium
l'l\|)OMIIV
Medium
l'l\|)OMIIV
Point
Km*|)lor
Population
Km'plor
\»e
l'l\pOMIIV
Koulo
Oii-Siic/
orr-siu-
Tj pe of
An;il\sis
Kiilioiiidc I'or Selection or l-'.\clusinii
of r.xposui'o P;i(h\\;i\
lulure
(continued)
1'ibli from low or
CdA River0
Subsistence
Recreational
CMd Adult
Illge;>U011
NA
Quani.
Children and adullb nia\ collect li^li dial
are potentially affected by impacted surface
water and sediments; therefore, this
pathway will be quantitatively evaluated.
Surface Soild
Surface Soil
Residential
Subsistence11
Recreational
Child/Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
Children and adults may potentially be in
direct contact with impacted surface soils
during outdoor activities at their homes
and/or parks; therefore, the ingestion and
dermal pathways will be quantitatively
evaluated.
Groundwater1
Tap Water
Residential
Child/Adult
Ingestion
Dermal
NA
NA
Quant.
Quant.
Groundwater for future scenario is not
currently being used as a drinking water
source; groundwater identified under the
current scenario is being used and will
continue to be used. Future groundwater
use near Canyon Creek and Ninemile Creek
was quantified.
Air
Resuspended
Particulates from
Surface Soils
Residential
Subsistence
Recreational
Child/Adult
Inhalation
NA
Qual.
The inhalation pathway is likely negligible
at the site as compared to the ingestion and
dermal contact pathways for soil, only lead
was quantified for air exposures.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-68
Table 7.1-6 (Continued)
Selection of Exposure Pathways
Baseline Risk Assessment, Harrison to Mullan
NA - Not applicable to CdA site; Quant. = quantitative analysis in the risk assessment; Qual. = qualitative analysis in the risk assessment; SW = surface water
aIn addition to impacts from surface soil erosion / stormwater runoff / impacted sediment, surface water is also affected by surface seepage of the groundwater.
bCattle graze in floodplain on grasses that grow in contaminated sediment. Wild fowl, also found in floodplain, are hunted and eaten by people.
°In addition to impacts from contaminated surface water, fish are also affected by contaminated sediments.
dIn addition to direct contact with tailing deposits and waste piles, other soils have been impacted by depositions from water- and air- transported materials.
"Terrestrial plant pathways were qualitatively discussed, data insufficient to evaluate risks (e.g., data from Hawthorne berries).
fIn addition to impacts from soil leachate, groundwater is also affected by surface water infiltration.
8Limited samples have been collected from a variety of terrestrial game animals, e.g., muskrat, beavers, and deer; however, data is insufficient for quantification,
qualitatively discussed in the risk assessment.
hNo subsistence populations have homes on impacted soils; however, subsistence exposures to surface soil were quantified under future conditions, assuming
populations live in the floodplain in the Lower Basin.
Note:
* Pathway also complete under a future exposure scenario
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-69
Table 7.1-7
Residential Exposure Factors for Non-Lead Chemicals
l'l\|)OMIIV Pill'illlH-U'l'
KMI. Value
Referenee
CT Value
Kel'erenee
l-lxposiire Assumptions lor Ingestion ol'('lu'inic;ils in Yiirri Soil
IRa: Ingestion rate - adult (mg/day)
100
USEPA 1991b
50
USEPA 1993
IRch: Ingestion rate - child (mg/day)
200
USEPA 1991b
100
USEPA 1993
EF: Exposure frequency (days/yr)
350
USEPA 1991b
260
A
EDa: Exposure duration - adult (years)
24
USEPA 1991b
7
USEPA 1993
EDch: Exposure duration - child (years)
6
USEPA 1991b
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
l-lxposure Assumptions for Dermal Conliiel with Chemienls in Yiirri Soil
SAa: Skin surface area - adult (cm2)
2,500
USEPA 1998b
2,500
USEPA 1998b
SAch: Skin surface area - child (cm2)
2,200
USEPA 1998b
2,200
USEPA 1998b
AFa: Adherence factor - adult (mg/cm2-event)
0.1
USEPA 1998b
0.1
USEPA 1998b
AFch: Adherence factor - child (mg/cm2-event)
0.2
USEPA 1998b
0.2
USEPA 1998b
EF: Exposure frequency (events/year)
350
USEPA 1991b
260
A
ED: Exposure duration - adult (years)
24
USEPA 1991b
7
USEPA 1993
ED: Exposure duration - child (years)
6
USEPA 1991b
2
USEPA 1993
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
ABS: Dermal absorption factor (unitless)
chem. specific
USEPA 1998b
chem. Specific
USEPA 1998b
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
I'lxposuiv Assumptions lor Ingestion of Tap Waler
IRa: Ingestion rate - adult (L/day)
2
USEPA 1991b
1.4
USEPA 1993
IRch: Ingestion rate - child (L/day)
1
USEPA 1999f
1
USEPA 1999f
EDa: Exposure duration - adult (years)
24
B
7
USEPA 1993
EDch: Exposure duration - child (years)
6
B
2
USEPA 1993
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
EF: Exposure frequency (days/yr)
350
USEPA 1991b
234
USEPA 1993
CF: Conversion factor (mg/|ig)
1.0E-03
NA
1.0E-03
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-70
Table 7.1-7 (Continued)
Residential Exposure Factors for Non-Lead Chemicals
l'l\|)OMIIV Pill'illlH-U'l'
KMI. Value
Kelerenee
CT Value
Rel'erenee
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
I'1\|)omiiv .Assiimplions lor Ingestion of Homegrown Vegetables
IRveg: Intake rate of homegrown vegetables
(g/kg-day)
5.04
C
0.492
C
EF: Exposure frequency (days/yr)
365
D
365
D
ED: Exposure duration (years)
30
USEPA 1991b
9
USEPA 1993
CF: Conversion factor (kg/g)
1.0E-03
NA
1.0E-03
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
Notes:
aExposure frequency was based on 3 months limited soil exposure due to snow-covered/frozen ground.
bUSEPA 1991b recommends an adult/child exposure duration of 24/6 years for ingestion of soil; for consistency, an
exposure duration of 24/6 years was selected for ingestion of tap water.
Ingestion rate is seasonally adjusted and incorporates the body weights of all participants in the study (children and
adults) from USEPA 1997b.
ingestion rate of vegetables is an average daily consumption rate, therefore 365 days/year was selected as the frequency
of exposure for both the RME and CT cases.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-71
Table 7.1-8
Neighborhood Recreational Exposure Factors for Non-Lead Chemicals
Exposure Paramclcr
U.MI'. Value
Ucl'crcnce
( T Value
Ucl'crcnce
Exposure Assumptions lor Ingestion of Chemicals in Waslc Pile Soil
IR: Ingestion rate (mg/day)
300
A
120
A
EF: Exposure frequency (days/yr)
17
B
8.5
B
ED: Exposure duration (years)
7
C
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
25,500
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Exposure Assumptions for Dermal Contact with Chemicals in Waste Pile Soil
SA: Skin surface area (enr)
5,080
USEPA 1997b
5,080
USEPA 1997b
AF: Soil to skin adherence factor
(mg/cm2-event)
0.2
USEPA 1998b
0.2
USEPA 1998b
AB S: Dermal absorption factor (unitless)
chem-specific
USEPA 1998b
Chem-specific
USEPA 1998b
EF: Exposure frequency (events/year)
34
E
17
E
ED: Exposure duration (years)
7
C
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Exposure Assumptions for Ingestion of Chemicals in I
>land Soil (Parks/Schools/Elk ( rock Area)
IR: Ingestion rate (mg/day)
300
A
120
A
EF: Exposure frequency (days/yr)
34
F
17
F
ED: Exposure duration (years)
7
C
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
25,500
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Exposure Assumptions for Dermal Contact with Chemicals in Upland Soil (Parks/Schools/Ell
i Creek Area)
SA: Skin surface area (cm2)
5,080
USEPA 1997b
5,080
USEPA 1997b
AF: Soil to skin adherence factor
(mg/cm2-event)
0.2
USEPA 1998b
0.2
USEPA 1998b
AB S: Dermal absorption factor (unitless)
chem-specific
USEPA 1998b
Chem-specific
USEPA 1998b
EF: Exposure frequency (events/year)
68
G
34
G
ED: Exposure duration (years)
7
C
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Exposure Assumptions for Ingestion of Chemicals in Hoodplain Soil/Sedimenl
IR: Ingestion rate (mg/day)
300
A
120
A
EF: Exposure frequency (days/yr)
21
H
10
H
ED: Exposure duration (years)
7
C
2
USEPA 1993
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-72
Table 7.1-8 (Continued)
Neighborhood Recreational Exposure Factors for Non-Lead Chemicals
I'.xpoSlirc I'ill'illlKMOl'
U.MI'. Value
Ucl'crcncc
( T Value
Ucl'crcncc
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
25,500
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Exposure Assumptions for Dermal Contaet with Chemicals in Floodplain Soil/Sediment
SA: Skin surface area (cm2)
5,080
I
5,080
I
AF: Soil to skin adherence factor
(mg/cm2-event)
0.2
USEPA 1998b
0.2
USEPA 1998b
AB S: Dermal absorption factor (unitless)
chem-specific
USEPA 1998b
Chem-specific
USEPA 1998b
EF: Exposure frequency (events/year)
96
J
48
J
ED: Exposure duration (years)
7
C
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Exposure Assumptions lor Ingestion of Surface Walcr
IR: Ingestion rate (mL/hour)
30
USEPA 1998d
30
USEPA 1998d
ET: Exposure time (hours/day)
1
USEPA 1997b
1
USEPA 1997b
EF: Exposure frequency (days/yr)
96
I
I
ED: Exposure duration (years)
7
C
2
USEPA 1993
CF 1: Conversion factor (mg/|ig)
0.001
NA
0.001
NA
CF2: Conversion factor (L/mL)
0.001
NA
0.001
NA
BW: Body weight (kg)
28
D
28
D
ATc: Averaging time - cancer (days)
2.6E+04
USEPA 1989c
2.6E+04
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Reference Notes:
aThe RME value of 300 mg/day is the 90th percentile soil intake from van Wijnen (1990); the CT value of 120 mg/day
is the mean soil intake from the same study, as cited in USEPA 1999f.
bExposure frequency is calculated as: 34 weeks/year x 7 hours/day x 1 day/week /14 hours/day = 17 days/year for the
RME; 34 weeks/year x 7 hours/day x once every other week, 0.5 /14 hours/day = 8.5 days/year.
Neighborhood exposure assumes children between the ages of 4 and 11 are playing in the waste piles.
Value is the 50th percentile for boys and girls, ages 4 to 11.
"Exposure frequency is calculated as: 34 weeks/year x 1 event/week = 34 events/year for RME; 34 weeks/year, once
every other week = 17 events/year for CT.
fThe exposure frequency is calculated as: 34 weeks/year x 7 hours/day x 2 days/week /14 hours/day = 34 days/year
for the RME; this assumes weekend outdoor exposure. For the CT, exposure frequency is 34 weeks/year x 7
hours/day x 1 day/week /14 hours/day =17 days/year.
8Exposure frequency is calculated as 34 weeks/year x 2 events/week = 68 events/year for RME, and 34 weeks/year x 1
event/week = 34 events/year.
hExposure frequency is calculated as 24 weeks/year x 3 hours/day x 4 days/week /14 hours/day = 21 days/year for the
RME case; 3 hours/day is the high end of the 50th percentile range (1 to 3 hours/day) from USEPA 1997b. For the
CT case, exposure frequency is 24 weeks/year x 3 hours/day x 2 days/week /14 hours/day = 10 days/year.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-73
Table 7.1-8 (Continued)
Neighborhood Recreational Exposure Factors for Non-Lead Chemicals
'Exposure frequency is calculated as 24 weeks/year x 4 events/week = 96 events/year for RME; and 24 weeks/year x 2
events/week = 48 events/year for the CT case.
JAt Lower Basin and Kingston (north-south confluence), a skin surface area of 7,960 cm2 was used to reflect the
possibility that swimming and therefore exposure of the entire body to contaminants in sediment could occur at these
locations. It was assumed that swimming would occur during 16 weeks of the year (the warmest months), while
wading and playing along the shoreline without swimming would occur during 8 weeks of the year. The median skin
surface area for male children age 4 to 11 is 9,400 cm2 (USEPA 1997b). The skin surface area was calculated as
follows: ((16 weeks x 9,400 cm2) + (8 weeks x 5,080 cm2)) / 24 weeks = 7,960 cm2
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-74
Table 7.1-9
Public Recreational Exposure Factors for Non-Lead Chemicals
lAposuiv Piiiiimolcr U.MI-! \ 'siluc Reference (TYiiliie Reference
r.\|)osiirc Assnmplions lor Ingestion of C"hemiciils in I phinri Soil (Piirks/Schools)
IRa: Ingestion rate - adult (mg/day)
100
USEPA 1991b
50
USEPA 1993
IRch: Ingestion rate - child (mg/day)
300
A
120
A
EFa: Exposure frequency - adult (days/yr)
30
B
15
B
EFch: Exposure frequency - child (days/yr)
34
B
17
B
EDa: Exposure duration - adult (years)
24
USEPA 1991b
7
USEPA 1993
EDch: Exposure duration - child (years)
6
USEPA 1991b
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
I'1\|)omiiv Assumptions for Dorniiil (ont;ict with (hcniiciils in I plnnri Soil (Piirks/Schools)
SAa: Skin surface area - adult (cm2)
2,500
USEPA 1998b
2,500
USEPA 1998b
SAch: Skin surface area - child (cm2)
2,200
USEPA 1998b
2,200
USEPA 1998b
AFa: Adherence factor - adult (mg/cm2-event)
0.1
USEPA 1998b
0.1
USEPA 1998b
AFch: Adherence factor - child (mg/cm2-event)
0.2
USEPA 1998b
0.2
USEPA 1998b
EF: Exposure frequency (events/year)
68
C
34
C
ED: Exposure duration - adult (years)
24
USEPA 1991b
7
USEPA 1993
ED: Exposure duration - child (years)
6
USEPA 1991b
2
USEPA 1993
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
AB S: Dermal absorption factor (unitless)
chem. Specific
USEPA 1998b
chem. Specific
USEPA 1998b
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
l-lxpoMiiv Assumptions for Ingestion of (hcniiciils in l-'looriphiin Soil/Sediment
IRa: Ingestion rate - adult (mg/day)
100
USEPA 1991b
50
USEPA 1993
IRch: Ingestion rate - child (mg/day)
300
A
120
A
EF: Exposure frequency (days/year)
32
D
16
D
EDa: Exposure duration - adult (years)
24
USEPA 1991b
7
USEPA 1993
EDch: Exposure duration - child (years)
6
USEPA 1991b
2
USEPA 1993
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-75
Table 7.1-9 (Continued)
Public Recreational Exposure Factors for Non-Lead Chemicals
i:\posiiro Parameter
U.MI'. Value
Uel'erenee
CT Value
Uel'erenee
l.\posurc Assumptions lor Dermal ( onlael willi Chemieals in Hnnriphiin Snil/Seriinieni
SAa: Skin surface area - adult (cm2)
18,000
USEPA 1998b
18,000
USEPA 1998b
SAch: Skin surface area - child (cm2)
6,500
USEPA 1998b
6,500
USEPA 1998b
AFa: Adherence factor - adult (mg/cm2-event)
0.1
USEPA 1998b
0.1
USEPA 1998b
AFch: Adherence factor - child (mg/cm2-event)
0.2
USEPA 1998b
0.2
USEPA 1998b
EF: Exposure frequency (events/year)
32
D
16
D
ED: Exposure duration - adult (years)
24
USEPA 1991b
7
USEPA 1993
ED: Exposure duration - child (years)
6
USEPA 1991b
2
USEPA 1993
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
AB S: Dermal absorption factor (unitless)
chem. Specific
USEPA 1998b
chem. Specific
USEPA 1998b
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
l-lxposiire Assumptions for In^eslinn ol'Surl'aee Waler
1R: Ingestion rate (mL/hour)
30
USEPA 1998d
30
USEPA 1998d
ET: Exposure time (hours/day)
1
USEPA 1997b
1
USEPA 1997b
EDa: Exposure duration - adult (years)
24
E
7
USEPA 1993
EDch: Exposure duration - child (years)
6
E
2
USEPA 1993
BWa: Body weight - adult (kg)
70
USEPA 1991b
70
USEPA 1991b
BWch: Body weight - child (kg)
15
USEPA 1991b
15
USEPA 1991b
EF: Exposure frequency (days/yr)
32
D
16
D
CF: Conversion factor (mg/|ig)
1.0E-03
NA
1.0E-03
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer, child/adult (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
ATnc: Averaging time - noncancer, child (days)
2,190
USEPA 1989c
730
USEPA 1989c
l'l\poMiiv Assumptions for In^eslinn of l-'isli
1R: Ingestion rate of fish (g/day)
46
ATSDR 1989c
25
USEPA 1997b
EF: Exposure frequency (days/yr)
365
F
365
F
ED: Exposure duration (years)
30
USEPA 1991b
9
USEPA 1993
CF: Conversion factor (kg/g)
1.0E-03
NA
1.0E-03
NA
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
10,950
USEPA 1989c
3,285
USEPA 1989c
Reference Notes:
aThe RME value of 300 mg/day is the 90th percentile soil intake from van Wijnen (1990); the CT value of 120 mg/day is the mean soil
intake from the same study, as cited in USEPA 1999f.
^RME exposure frequency for adult: 34 weeks/year x 7 hours/day x 2 days/week / 16 hours/day = 30 days/year; for child: 34 weeks/year
x 7 hours/day x 2 days/week / 14 hours/day = 34 days/year. Two days/week assumes weekend outdoor exposure. The CT exposure
frequency for adults is: 34 weeks/year x 7 hours/day x 1 day/week / 16 hours/day =15 days/year; for a child, 34 weeks/year x 7
hours/day x 1 day/week / 14 hours/day =17 days/year.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-76
Table 7.1-9 (Continued)
Public Recreational Exposure Factors for Non-Lead Chemicals
cExposure frequency is calculated as: 34 weeks/year x 2 events/week = 68 events/year for the RME case; 34 weeks/year x 1
event/week = 34 events/year for the CT case.
Professional judgment
eUSEPA 1991b recommends an adult/child exposure duration of 24/6 years for ingestion of soil; for consistency, an exposure duration of
24/6 years was selected for ingestion of tap water,
ingestion rate of fish is an average daily consumption rate, therefore 365 days/year was selected as the frequency of exposure for both
the RME and CT cases.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-77
Table 7.1-10
Occupational Exposure Factors for Non-Lead Chemicals
I'lxposuiv Piii'iimeler
KMI. Value
Referenee
(1 Value
Referenee
r.xposuro Assumptions lor Ingestion of ('hemie;ils in ('nnslruelinn Silo Soil
IR: Ingestion rate (mg/day)
300
USEPA 1999f
200
USEPA 1999f
EF: Exposure frequency (days/yr)
195
A
43
A
ED: Exposure duration (years)
25
USEPA 1991b
6.6
USEPA 1997b
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
70
USEPA 1991b
70
USEPA 1991b
ATc: Averaging time - cancer (days)
25,500
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
9,125
USEPA 1989c
2,409
USEPA 1989c
I'1\|)ommv Assumptions for Derniiil Conlncl with ('hemie;ils in ('nnslruelinn Silo Soil
SA: Skin surface area (cm2)
2,500
USEPA 1998b
2,500
USEPA 1998b
AF: Soil to skin adherence factor (mg/cm2-event)
0.1
USEPA 1998b
0.1
USEPA 1998b
ABS: Dermal absorption factor (unitless)
Chem-specific
USEPA 1998b
chem-specific
USEPA 1998b
EF: Exposure frequency (events/year)
195
A
43
A
ED: Exposure duration (years)
25
USEPA 1991b
6.6
USEPA 1997b
CF: Conversion factor (kg/mg)
1.0E-06
NA
1.0E-06
NA
BW: Body weight (kg)
70
USEPA 1991b
70
USEPA 1991b
ATc: Averaging time - cancer (days)
25,550
USEPA 1989c
25,550
USEPA 1989c
ATnc: Averaging time - noncancer (days)
2,555
USEPA 1989c
730
USEPA 1989c
Reference Note:
A-Professional judgment
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-78
Table 7.1-11
Toxicity Data Summary
\OVt AM 1 K TOXK'ITN DA 1 A—OKAI./DI KMAI.
('lK-lllk;il
ol'
(lllH'lTIl
C'h roil it/
Siilu'liriuik'
Or.il KID
Value
Oral KID
I nils
l)erm;il
KID
Di'i'niiil
KID
I nils
l-'lldpiiilll/I'l-illl;! l'\
T;ir»i-I Or»;in
CiinihiiU'd
I iKii'l;iinl\/
MuililX ini;
l'":iiliirs
Siuirivs ul'
KID/
T;ir»i-I Or»:in
I);ik's ul' KID:
Or»;in
(MM/DD/^ )
Antimony
Chronic
4.00E-04
mg/kg-day
NA
mg/kg-
day
LOAEL/longevity,
blood chemistry
1,000
IRIS
10/25/99
Arsenic
Chronic
3.00E-04
mg/kg-day
NA
mg/kg-
day
NOAEL/skin
pigmentation
3
IRIS
10/25/99
Cadmium (food)
Chronic
1.00E-03
mg/kg-day
2.50E-05
mg/kg-
day
NOAEL/proteinuria
10
IRIS
10/25/99
Cadmium (water)
Chronic
5.00E-04
mg/kg-day
NA
NA
NOAEL/proteinuria
10
IRIS
10/25/99
Iron
NS
3.00E-01
mg/kg-day
NA
mg/kg-
day
NS
1
Region III
RBCs &
NCEA
10/25/99
Leada
Manganese (food)
Chronic
1.40E-01
mg/kg-day
NA
mg/kg-
day
NOAEL/Central
Nervous System
1
IRIS
10/25/99
Manganese (water)
Chronic
4.70E-02
mg/kg-day
NA
mg/kg-
day
NOAEL/Central
Nervous System
3
IRIS
10/25/99
Methylmercury
Chronic
1.00E-04
mg/kg-day
NA
mg/kg-
day
prenatal
developmental
effects
10
IRIS
10/25/99
Zinc
Subchronic
(10 weeks)
3.00E-01
mg/kg-day
NA
mg/kg-
day
LOAEL/enzyme-
level effects
3
IRIS
10/25/99
t'AMT'K TOXIC i n DA 1 A—OKAI./DI KMAI.
(Iiimii;il
ul'
ClIIHlTIl
Oliil
('ink-it
Slope
1'iKinr
l)erm;il
ClIIHlT
Slope
l-'iiiliir1'
I nils
\\ei»hl ul'
ll\ kleme/
C'lllUlT
Gukleline
Description
Si ill riv
D;ik-
(MM/DD/^^ )
-
-
-
Arsenic
1.50E+00
NA
(mg/kg-d)"1
A
IRIS
10/25/99
-
-
-
"Toxicity criteria not applicable for lead; see discussion in text
bThe oral slope factor will be used to evaluate dermal exposures (USEPA Region 9 PRG Tables)
Notes:
N/A - Not Applicable
NS - Not Specified
— no value available
NOAEL - No observed adverse effect level
LOAEL - Lowest observed adverse effect level
IRIS - Integrated Risk Information System
NCEA - National Center for Environmental Assessment
Weight of Evidence/Cancer Guideline Description
A - Human carcinogen
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-79
Table 7.1-12a
Predicted Lead Risk for a Typical Child
Upper Basin, Side Gulches, and Kingston
Predicted Risk (Percent) of Attaining ;i Blood Lead l.e\el of 10 n«/dl. for a Topical 'J-X4
Month Child
Soil Action Level
EPA Default Model
Box Model
2,000 mg/kg
64-70%
24-31%
1,500 mg/kg
50-58%
14-20%
1,000 mg/kg
32-46%
7-12%
800 mg/kg
30-36%
6-7%
600 mg/kg
20-33%
3-4%
400 mg/kg
5-6%
1
Note:
Adapted from HHRA Figures 8-8a-g
Predicted risks are ranges of all subareas excluding the Lower Basin. Lower Basin risks are presented separately
because exposures associated with elevated blood lead levels are associated with exposures to Coeur d'Alene River
sediments rather than residential soil. Lower Basin exposure patterns were described in the HHRA based on PHD
LHIP follow-up investigations of children with elevated blood lead levels.
Table 7.1-12b
Predicted Lead Risk for a Typical Child
Lower Basin
Predicted Kisk (Percent) of Attaining
A Blood Lead l.c\cl of III u^/dl. Tor a Topical V-S4 Month Child
Soil Action Level
EPA Default Model
Box Model
2,000 mg/kg
59%
16%
1,500 mg/kg
48%
11%
1,000 mg/kg
38%
7%
800 mg/kg
31%
5%
600 mg/kg
17%
2%
400 mg/kg
-
-
Note:
Adapted from HHRA Figures 8-8a-g
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-80
Table 7.1-13
RME Risk Characterization Summary - Carcinogens Residential Exposure Scenario -
Child/Adult
Scenario Timeframe: Current/Future
Receptor Population: Residents
Receptor Age: Child/Adult
( ;irciiio;ic'iiic Risk
Medium
Kxposuiv
Medium
l'l\|)OMIIV
Point
( hcmiciil
of Concern
Ingestion
Inhidiilinn
l)erm;il
Kxposuiv
Routes
lol;il
Lower ISiisiu
Soil
Surface Soil
Yard Soil
Arsenic
7E-05
N/A
8E-06
8E-05
Groundwater
Groundwater
Tap Water
Arsenic
2E-05
N/A
N/A
2E-05
Total Risk: 1E-04
I |)|HT liiisill''
Soil
Surface Soil
Yard Soil
Arsenic
7E-05
N/A
8E-06
8E-05
Groundwater
Groundwater
Tap Water
Arsenic
2E-04
N/A
N/A
2E-04
Total Risk: 3E-04
aOnly the Side Gulches area had cancer risks exceeding 10"4.
Notes:
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-81
Table 7.1-14
RME Risk Characterization Summary - Non-Carcinogens
Residential Exposure Scenario - Child
Scenario Timeframe: Current/Future
Receptor Population: Residents
Receptor Age: Child (0 to 6 years)
Mi-ilium
l'A|)OMIIV
Medium
Pllilll
('lli-lllii;d
of
( OIlllTIl
PrimiiiA
T;ir»i-l
()r»;iir'
Inui'sliim
Nuii-(':iriiin»»i
liihiihiliuii
nil' 1 l;i/.;ird Quol
l)i-rm;d
i'ii is/I mlii'i-s'1
l'\|)osuiv Kouli's Tohil
l.mn-r li.isin
Soil
Surface Soil
Yard Soil
Arsenic
Skin
1
N/A
0.14
1
[ron
Blood
2
N/A
N/A
2
Total Soil Hazard Indexb
3
I |)|K'I' li;isill'
Soil
Surface Soil
Yard Soil
Arsenic
Skin
1
o
N/A
0.06-0.1
0.6-1
[ron
Blood
©
vo
1
N/A
N/A
0.9-1
Total Soil Hazard Index
2-3
Groundwater
Groundwater
Tap Water
Arsenic
Skin
2
N/A
N/A
2
Total Tap Water Hazard Index
2
Groundwater
Groundwater
Future
Drinking
Water
Cadmium
fCidney
17
N/A
N/A
17
Zinc
Blood
4
N/A
N/A
4
Total Future Groundwater Hazard Index
21
All Aiv;is
Soil
Plant Tissue
Homegrown
Vegetables
Cadmium
fCidney
2
N/A
N/A
2
Total Soil Hazard Index
2
aNone of the chemicals within one media/receptor group have similar target organ endpoints; therefore, separate total
summaries by target organ are not provided.
''Note that all hazard quotients and indices are rounded to one significant figure per EPA guidance, and a hazard of 1, for
example, could range between 0.95 and 1.4. Therefore, totals may not look as if they add up correctly.
°The Upper Basin was evaluated as seven separate sub-areas; consequently hazards for soil are provided as ranges based on
the results from the seven areas. For groundwater, current tap water, only the Side Gulches area had concentrations
exceeding target health goals. For groundwater, future drinking water, only the Burke/Ninemile area had shallow
groundwater evaluated.
Notes:
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-82
Table 7.1-15
RME Risk Characterization Summary - Non-Carcinogens Residential Exposure Scenario -
Child/Adult
Scenario Timeframe:
Current/Future
Receptor Population:
Residents
Receptor Age:
Child/Adult
Priniiin
\on-(
iiivino"cnic ll;i/;ird (Junlk-nls/lndiiTs''
Medium
|-l\|)OMMV
Medium
|-A|)OMIIV
Point
Chcmk-iil
of Concern
'hiriicl
()r»;inh
Ingestion
1 n h;i hi lion
Dcrniiil
l'l\|)OSIIIV
Ron It's 1 oliil
I |)|HT IS;isin'
Soil
Surface Soil
Yard Soil
Arsenic
Skin
0.4
N/A
0.04
0.4
Iron
Blood
0.3
N/A
N/A
0.3
Total Soil Hazard Index
0.7
Groundwater
Groundwater
Tap Water
Arsenic
Skin
1
N/A
N/A
1
Total Tap Water Hazard Index
1
Total Receptor Hazard Index
2
Groundwater
Groundwater
Future
Cadmium
Kidney
9
N/A
N/A
9
Drinking
Water
Zinc
Blood
2
N/A
N/A
2
Total Tap Water Hazard Index
11
All Aivsis
Soil
Plain Tissue
Homegrown
Kjadimum
Kidney
Vegetables
2
N/A
N/A
2
Total Soil Hazard Index
2
aNote that all hazard quotients and indices are rounded to one significant figure per EPA guidance, and a hazard of 1, for
example, could range between 0.95 and 1.4. Therefore, totals may not look as if they add up correctly.
''None of the chemicals within one media/receptor group have similar target organ endpoints; therefore, separate total
summaries by target organ are not provided.
°The Upper Basin was evaluated as seven separate sub-areas; consequently hazards for soil are provided as ranges based on
the results from the seven areas. For groundwater, current tap water, only the Side Gulches area had concentrations
exceeding target health goals. For groundwater, future drinking water, only the Burke/Ninemile area had shallow
groundwater evaluated.
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-83
Table 7.1-16
RME Risk Characterization Summary - Non-Carcinogens Public Recreational Exposure Scenario - Child
Scenario Timeframe: Current/Future
Receptor Population: Visitor
Receptor Age: Child (0 to 6 years)
\on-( iircinoiicnic ll;i/;ird Quotients/Indices'
l'l\|)OMIIV
( lu'iniciil of
Priniiin
l'l\|)OSIIIV
Medium
Mod in ill
I'.xposiiiv Point
( niiccrn
Tsirgcl ()r»;inh
Ingestion
Inhiihilion
l)i'i'iii;il
Ron It's loliil
Low ci' liiisiu
Soil. Sediment
Soil. Sediment
I loodplain Soil. Sediment in
Arsenic
Skin
0.4
\.A
0.1
0 s
Lower CDAR
Iron
Blood
0.6
N/A
N/A
0.6
Manganese
Central Nervous
System (CNS)
0.4
N/A
N/A
0.4
Total Soil Hazard Index
2
I niter liiisin
Soil Sediment
Soil Sediment
Surface Soil and Beach Sedinienb
Arsenic
Skin
U.fc>
N/A
u.l
U.7
near confluence of North and
Iron
Blood
0.6
N/A
N/A
0.6
South Forks CDAR was only
Manganese
Central Nervous
0.3
N/A
N/A
0.3
location with exceedances
System (CNS)
Total Soil Hazard Index
2
aNote that all hazard quotients and indices are rounded to one significant figure per EPA guidance, and a hazard of 1, for example, could range between 0.95 and
1.4. Therefore, totals may not look as if they add up correctly.
bNone of the chemicals within one media/receptor group have similar target organ endpoints; therefore, separate total summaries by target organ are not
provided.
Notes:
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
CDAR - Coeur d'Alene River
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-84
Table 7.1-17
RME Risk Characterization Summary - Carcinogens Subsistence Exposure Scenario -
Child/Adult
Scenario Timeframe:
Future
Receptor Population:
Subsistence Residents
Receptor Age:
Child/Adult
(iircinoiicnic Risk
Medium
l'l\|)OMire
Medium
l'l\|)OMire Point
( hemiciil
of Concern
Ingestion
Inhibition
Derniiil
l'l\|)OMire
Routes
To(;il
11'iidilioiiiil Subsistence
Soil
Surface Soil
Floodplain Surface
Soil
Arsenic
6E-04
N/A
2E-04
8E-04
Sediment
Sediment
Floodplain
Sediment
Arsenic
4E-04
N/A
7E-04
1E-03
Undisturbed
Surface Water
Undisturbed
Surface
Water
Lower CDAR
Arsenic
1E-03
N/A
N/A
1E-03
Total Risk
3E-03
Modern Subsistence
Soil
Surface Soil
Floodplain Surface
Soil
Arsenic
1E-04
N/A
7E-05
2E-04
Sediment
Sediment
Floodplain
Sediment
Arsenic
1E-04
N/A
2E-04
3E-04
Undisturbed
Surface Water
Undisturbed
Surface
Water
Lower CDAR
Arsenic
2E-04
N/A
N/A
2E-04
Total Risk
7E-04
Notes:
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
CDAR - Coeur d'Alene River
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-85
Table 7.1-18
RME Risk Characterization Summary - Non-Carcinogens
Subsistence Exposure Scenario - Child
Scenario Timeframe: Future
Receptor Population: Subsistence Residents
Receptor Age: Child (0 to 6 years)
\iiii-(';iriiin»»i-nii- 1 hi/.uid Qiioiii-iils/lndiii-s''
r.\|)usinv
r.\|)osinv
C'lu'inii'iil
Priniiirx T;ir»i-l
r.\|»>Miri- kuuii's
Medium
Mi-dium
Poim
of Co mi-rn
Or»;in
lii^i'slion
lllll;il;iliiili
l)i'l'lll;il
Tohil
l r;idilinii;il Siihsisk-ni'i-
Soil
Surface Soil
Floodplain
Antimony
Blood
1
N/A
N/A
1
Surface Soil
Arsenic
Skin
5
N/A
2
7
Cadmium
Kidney
0.6
N/A
0.14
0.8
Iron
Blood
7
N/A
N/A
7
Manganese
Central Nervous
System (CNS)
4
N/A
N/A
4
Total Soil Hazard Index
19
Sediment
Sediment
Floodplain
Antimony
Blood
0.7
N/A
N/A
0.7
Sediment
Arsenic
Skin
3
N/A
2
5
Cadmium
Kidney
0.5
N/A
0.3
0.8
Iron
Blood
4
N/A
N/A
4
Manganese
CNS
3
N/A
N/A
3
Total Sediment Hazard Index
14
Undisturbed
Undisturbed
Lower
Arsenic
Skin
7
N/A
N/A
7
Surface Water
Surface Water
CDAR
Total Undisturbed Surface Water Hazard Index
7
Total Receptor Hazard Index
39
Blood Hazard Index
13
Skin Hazard Index
18
Kidney Hazard Index
2
CNS Hazard Index
6
Modi-ni
Soil
Surface Soil
Floodplain
Arsenic
Skin
0.8
N/A
0.3
1
Surface Soil
Iron
Blood
1
N/A
N/A
1
Manganese
CNS
0.6
N/A
N/A
0.6
Total Soil Hazard Index
3
Sediment
Sediment
Floodplain
Arsenic
Skin
1
N/A
0.7
2
Sediment
Iron
Blood
1
N/A
N/A
1
Manganese
CNS
0.8
N/A
N/A
0.8
Total Sediment Hazard Index
3
Undisturbed
Undisturbed
Lower
Arsenic
Skin
1
N/A
N/A
1
Surface Water
Surface Water
CDAR
Total Undisturbed Surface Water Hazard Index
1
Total Receptor Hazard Index
7
Blood Hazard Index
2
Skin Hazard Index
4
CNS Hazard Index
1
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-86
Table 7.1-18 (Continued)
RME Risk Characterization Summary - Non-Carcinogens
Subsistence Exposure Scenario - Child
aNote that all hazard quotients and indices are rounded to one significant figure per EPA guidance, and a hazard of 1, for example,
could range between 0.95 and 1.4. Therefore, totals may not look as if they add up correctly.
Notes:
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
CDAR - Coeur d'Alene River
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-87
Table 7.1-19
RME Risk Characterization Summary - Non-Carcinogens
Subsistence Exposure Scenario - Child/Adult
Scenario Timeframe: Future
Receptor Population: Subsistence Residents
Receptor Age: Child/Adult
l'.\|)OSUIV
Medium
l!\|)osuiv
Point
('Ik-mk;il ill'
(uihitii
P|-illl:i|->
T;ir»i-I ()r»;ui
\iiii-(';iriiiiii»i-iik- 1 l;i/.;ird Qiiiilk-nls/liidkiV'
Medium
lii"i'sliiin
lllll;il:iliiill
l)i'l'lll;il
r.\i>iisiiiv Koiiu-s
||||;||
Tr;i(lilion;il
Soil
Surface Soil
Floodplain
Arsenic
Skin
1
N/A
0.5
2
Surface Soil
Iron
Blood
2
N/A
N/A
2
Manganese
Central
Nervous
System (CNS)
1
N/A
N/A
1
Total Soil Hazard Index
5
Floodplain
Sediment
Arsenic
Skin
0.8
N/A
2
2
Sediment
Sediment
Iron
Blood
1
N/A
N/A
1
Manganese
CNS
0.7
N/A
N/A
0.7
Total Sediment Hazard Index
4
Undisturbed
Surface Water
Undisturbed
Surface
Water
Lower CDAR
Arsenic
Skin
3
N/A
N/A
3
Total Undisturbed Surface Water Hazard Index
3
Surface
Water/Sediment
Plant Tissue
Water Potato
(with skin)
Cadmium
Kidney
4
N/A
N/A
4
Total Water Potato (with skin) Hazard
4
Surface
Water/Sediment
Animal
Tissue
Northern Pike
in Lower
CDAR
Methylmercury
CNS
10
N/A
N/A
10
Total Northern Pike Hazard Index
10
Total Receptor Hazard Index
26
Blood Hazard Index
3
Skin Hazard Index
7
CNS Hazard Index
12
Kidney Hazard Index
4
Modern
Soil
Surface Soil
Floodplain
Arsenic
Skin
0.2
N/A
0.2
0.4
Surface Soil
Iron
Blood
0.3
N/A
N/A
0.3
Total Soi
Hazard Index
0.7
Sediment
Sediment
Floodplain
Arsenic
Skin
0.2
N/A
0.4
0.7
Sediment
Iron
Blood
0.4
N/A
N/A
0.4
Total Sediment Hazard Index
1
Undisturbed
Undisturbed
Lower CDAR
Arsenic
Skin
0.5
N/A
N/A
0.5
Surface Water
Surface
Water
Total Unc
isturbed Surface Water Hazard Index
0.5
Surface
Water/Sediment
Animal
Tissue
Northern Pike
in Lower
CDAR
Methylmercury
CNS
3
N/A
N/A
3
Total Northern Pike Hazard Index
3
Total Receptor Hazard Index
5
Blood Hazard Index
0.7
Skin Hazard Index
2
CNS Hazard Index
3
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-88
Table 7.1-19 (Continued)
RME Risk Characterization Summary - Non-Carcinogens
Subsistence Exposure Scenario - Child/Adult
aNote that all hazard quotients and indices are rounded to one significant figure per EPA guidance, and a hazard of 1, for example,
could range between 0.95 and 1.4. Therefore, totals may not look as if they add up correctly.
Notes:
RME - reasonable maximum exposure
N/A - Route of exposure is not applicable to this medium
CDAR - Coeur d'Alene River
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-89
Table 7.1-20
Potential Soil Cleanup Levels for Arsenic Using Various Target Risk Goals and Scenarios
Kcsidcnliiil Soil
Inji. And
Dcrniid
(child )
niii/kji
Kcsidcnliiil
Soil ln;i. ;ind
Dcrniid
(child/iidull)
m»/k»
Public Kccrciilioiiiil
Soil/Scd Inji. iind
Dcrniid
(child <>-(>)
mji/kli
Public Kccrciilioiiiil
Soil/Scd Inji. iind
Dcrniid
(child/iidull)
mii/kii
Neighborhood
Kccrciilioiiiil
Wsislc Pile 1 ii}».
And Dcrniid
(child 4-11)
in*i/kii
Neighborhood
Kccrciilioiiiil Soil/Scd
Inii. And Dcrniid
(child 4-11)
Lowci' ISiisin iind
Kingston
mii/kii
Neighborhood
Kccrciilioiiiil Soil/Scd
Inji. And Dcrniid
(child 4-11)
All oilier iirciis
m*i/kii
Arsenic - Cancer
(10~4 risk)
64
420
1,663
815
1,016
Arsenic - Cancer
(10~5 risk)
6
42
166
81
102
Arsenic - Cancer
(10~6 risk)
1
4
17
8
10
Arsenic -
Noncancer
(Hazard goal of
one)
35
123
234
810
748
367
457
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-90
Table 7.1-21
Summary of Chemicals of Concern and Exposure Point Concentrations in Spokane River
CUA Sediment
Scenario Timeframe: Current
Medium: Sediment
Exposure Medium: Sediment
( oneenl r
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-91
Table 7.1-22
Summary of Chemicals of Concern and Exposure Point Concentrations in Spokane River
Fish Tissue
( homiciil
( nniTiili'iilinii
Dok'Ck'd (Wei WoiiilKI
l"lV(|IK'IIC\ (if
r.\|)osiMV Point
or
(miiTi'ii
Mill
(nili/kiil
M:i\
(mji/kii)
IkMi'Clion
(iiiii/kii)
Mxposuiv Point
( OIKTIIIl'illioil
Sliiiisiiciil
Mi'.ismv
Fillet Fish from
Spokane River -
Ingestion
Wild Rainbow
Trout
Lead
0.03
0.48
19/19
0.12
geometric mean
Hatchery Rainbow
Trout
Lead
0.02
0.23
5/5
0.11
geometric mean
Large Scale Sucker
Lead
0.02
0.28
20/20
0.07
geometric mean
Mountain
Whitefish
Lead
0.02
0.07
10/10
0.03
geometric mean
Whole fish from
Spokane River -
Ingestion
Wild Rainbow
Trout
Lead
0.6
1.14
3/3
0.79
geometric mean
Hatchery Rainbow
Trout
Lead
1.59
1.59
1/1
1.59
Max
Large Scale Sucker
Lead
1.77
4.34
4/4
2.56
geometric mean
Mountain
Whitefish
Lead
0.56
0.65
2/2
0.6
geometric mean
Notes:
Min - minimum
Max - maximum
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-92
Table 7.2-1
Summary of Representative Species Evaluated in Coeur d'Alene Basin
Sin-iir- 1 c\ el nl liinln^k jl ()r:Miii/:iliiiii In lie \--r--ril
11 '¦ lli|.l1 ll;iliil;il l\ pr- mill < S\| 1 nil-'1
( iiiiiiiiiin \ainr | Siiinlilii Niiinr | lmli\iilu:il-lr\cl | 1 '• >pnLil!• »-l | ( iiiiiiiiunil\-li\il | IcmI ||{i\rrinr| 1 naMiinr |l':iln»lriiit-|ui|mri:iii| 1 |il:iinl| Wriailliiral
liii.K
Great blue heron
Ardea herodias
X
X
3
3,4,5
Canada goose
Branta canadensis
X
X
5
3,4,5
3
Tundra swan
Cygnus columbianus
X
X
3
3,4
Wood duck
Aix sponsa
X
X
3,4,5
Mallard
Anas platyrhynchos
X
X
5
1,2,3,4,5
Lesser scaup
Aythya affinis
X
X
3,4,5
Common goldeneye
Bucephala clangula
X
X
5
3,4,5
Common merganser
Mergus merganser
X
X
2,3,5
3,4,5
Osprey
Pandion haliaetus
X
X
2,3,5
3,4,5
Bald eagle (T&E)
Haliaeetus leucocephalus
X
X
3
3,4,5
3
Northern harrier
Circus cyaneus
X
X
3,4
3,5
3
American kestrel
Falco sparverius
X
X
3,5
3
Ruffed grouse
Bonasa umbellus
X
1,2
Wild turkey
Meleagris gallopavo
X
1,2,3,5
1,2
3
Spotted sandpiper
Actitis macularia
X
X
1,2,3,5
Common snipe
Gallinago gallinago
X
X
2,3,4
3
Black tern (species of concern)
Chlidonias niger
X
X
3,4
3,4
Great horned owl
Bubo virginianus
X
X
1,2,3,5
3
Belted kingfisher
Ceryle alcyon
X
X
3,4,5
Tree swallow
Tachycineta bicolor
X
X
1,2,3,5
3,4,5
American dipper
Cinclus mexicanus
X
X
1,2
Swainson's thrush
Catharus ustulatus
X
X
1,2
1,2
American robin
Turdus migratorius
X
X
1,2,3,5
3
Song sparrow
Melospiza melodia
X
X
1,2,3,5
Mammals
Water shrew
Sorex palustris
X
1,2
Masked shrew
Sorex cinereus
X
1,2
Vagrant shrew
Sorex vagrans
X
2,3,5
3
Long-legged myotis (species of
concern)
Myotis volans
X
X
1,2,3,5
1,2
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-93
Table 7.2-1 (Continued)
Summary of Representative Species Evaluated in Coeur d'Alene Basin
S|HTir-
1 CW'I I
1 IJiiiliiUKiil < )l!Mlli/;lli(ill In lie
Ihiliiim
ll;iliil;il l\ pr- mill < S\| 1 nil-'
llllivwlrlll-
( nmmiiii \miir
Siirlllilk' Niillic
lmli\ iilihil-lcw-l
rii|iiil:ilinii-lc\cl
( i Hiiiiiuiiil \ -11-\ t l
ll'M'l
kiMiinr
l.iKiMrinc
l';iliMiinc
|{i|i;iriiin
1 plmiil
Auriailliirnl
Little brown myotis
Myotis lucifugus
X
3,5
3,4,5
2,3,4,5
Raccoon
Procyon lotor
X
1,2,3,5
1,2,3,4,5
1,2,3,5
1,2
3
Fisher (species of concern)
Martes pennanti
X
X
1,2
1,2
Wolverine (species of concern)
Gulo gulo luscus
X
X
1,2
1,2
Mink
Mustela vison
X
1,2,3,5
1,2,3,4,5
1,2,3,5
River otter
Lontra canadensis
X
3,5
3,4,5
Gray wolf (T&E)
Canis lupus
X
X
3
1,2,3
1,2
3
Lynx (T&E)
Lynx canadensis
X
X
1,2
White-tailed deer
Odocoileus virginianus
X
4
1,2,3,5
3
Mule deer
Odocoileus hemionus
X
1,2
Beaver
Castor canadensis
X
1,2,3,4,5
1,2,3,5
Muskrat
Ondatra zibethicus
X
1,2,3,4,5
1,2,3,5
Deer mouse
Peromyscus maniculatus
X
1,2,3,5
1,2
3
Meadow Mile
snnsylvanicus
X
1.2.3.5
3
1 Mi
Bull trout (T&E)
Salvelinus confluentus
X
1,2,3,5
3,4,5
Westslope cutthroat trout (species of
concern)
Oncorhynchus clarki lewisi
X
1,2,3,5
3,4,5
Chinook salmon
Oncorhynchus tshawytscha
X
2,3
4
Rainbow trout
Oncorhynchus mykiss
X
2,3,5
Mountain whitefish
Prosopium williamsoni
X
2,3
Large-scale sucker
Catostomus macrocheilus
X
3,5
Brown bullhead
Ameiurus melas
X
3
Northern pike
Esox lucius
X
3
3,4
Sculpins
X
1,2
Smallmouth bass
Micropterus dolomieu
X
3
Largemouth bass
Micropterus salmoides
X
3
Yellow perch
Perca flavescens
X
3
Walleye
Stizostedion vitreum
X
5
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-94
Table 7.2-1 (Continued)
Summary of Representative Species Evaluated in Coeur d'Alene Basin
Specie- 1 e\ el nl liinln^K jl ()r:Miii/:ilipiilali<>n-lc\cl | < niiiiiiuiiil\-li\il | level ||{i\crinc| l.aciMrinc |raliMriiic|l{iparian| 1 |il;iml |A
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-95
Table 7.2-1 (Continued)
Summary of Representative Species Evaluated in Coeur d'Alene Basin
Spriir-
1 I'M'I I
riiinlii"U:il ()i ";iiii/;iliini In lie
Ihiliiim
ll;iliil;il l \pro mill ( S\| 1 nil-'
llllivwll-lll-
( nmmiiii \miir
Viinlilii Niiinc
lnili\ iilihil-lrM'l
rii|iiil:ilinii-lc\cl
( iHiiiiiiiiiil \ -11-\ t l
ki\irinr
l.iKiMrinc
riiliMrinc Uipuriiin
1 plmiil
•E
zi
1 filialii;il liiMrU'lirnlc"
Mixed inverlebrales
1.2.3.5
1.2
Soil microbial processes
1.2.3.5
1.2
Sllil I'll
1.2.3.5
1.2
1 miiKi'iipc < kinuliThliiv
1.2.3
1.2.3
" The numbers in these columns refer to individual CSM Units (1, 2, 3, 4, or 5)
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-96
Table 7.2-2
Concentrations of Chemicals of Potential Ecological Concern
Soil-Sediment Combined
Minimum
Miiximum
Number of
Number of
Di'U'Clcd.
Dok'Ck'd.
Mciin.
*>5% 1(1.
CSM I nil
("hem ic;i 1
Siimplcs
Ik'lcclions
niii/kji
mii/kji
mii/kji
of Mo;iii. niii/kii
1 &2
Arsenic
327
322
1.40
3,610
82.2
102
1 &2
Cadmium
410
311
0.113
543
27.0
32.1
1 &2
Copper
364
335
5.79
3,100
153
174
1 &2
Lead
482
403
5.16
67,100
6,865
7,800
1 &2
Mercury
259
212
0.011
51.5
3.93
4.78
1 &2
Silver
256
221
0.170
347
23.1
27.5
1 &2
Zinc
420
337
10.0
83,900
3,792
4,480
3
Arsenic
1,269
1,152
1.00
634
111
116
3
Cadmium
1,401
1,291
0.210
200
25.2
26.1
3
Copper
804
771
2.10
554
119
123
3
Lead
1,483
1,404
9.00
35,600
3,665
3,802
3
Mercury
703
644
0.010
23
2.57
2.699
3
Silver
680
635
0.269
97.9
17.8
18.6
3
Zinc
1,408
1,327
7.70
21,800
3,269
3,405
4
Arsenic
345
220
0.710
275
18.1
22.4
4
Cadmium
345
301
0.130
148
7.2
9.09
4
Copper
219
219
5.60
283
35.6
40.0
4
Lead
345
345
4.80
12,100
269
351
4
Mercury
218
102
0.020
4.8
0.562
0.718
4
Silver
218
101
0.240
22.8
2.26
2.83
4
Zinc
345
345
10.2
9,100
612
717
5
Arsenic
59
59
5.90
83.4
33.3
37.4
5
Cadmium
59
59
2.10
28
14.2
15.6
5
Copper
59
59
17.3
144
46.5
51.5
5
Lead
59
59
54.7
3,500
624
730
5
Mercury
59
36
0.110
0.78
0.333
0.385
5
Silver
59
33
0.540
4.7
1.72
2.02
5
Zinc
59
59
265
6,500
2,375
2,628
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-97
Table 7.2-3
Chemicals of Potential Ecological Concern
Aquatic Sediments
Minimum
Miiximum
Number of
Number ol'
Di'U'Clcd.
Dok'Ck'd.
Mciin.
*>5% 1(1.
CSM I nil
(hi-miciil
Siimplcs
lkkc lions
niii/kji
mii/kji
mii/kji
ol' Mo;iii. niii/kii
1 &2
Arsenic
74
72
2.00
384
107
124
1 &2
Cadmium
68
61
0.560
177
26.6
33.5
1 &2
Copper
74
73
16.0
706
143
173
1 &2
Lead
74
74
9.00
40,500
6,039
7,983
1 &2
Mercury
64
52
0.030
25.1
4.57
6.10
1 &2
Silver
71
51
1.00
120
23.592
30.1
1 &2
Zinc
74
74
22.0
9,900
2,574
3,031
3
Arsenic
1,110
993
1.00
634
111
116
3
Cadmium
1,110
1,083
0.280
200
25.7
26.7
3
Copper
562
562
2.10
554
129
134
3
Lead
1,117
1,116
14.8
35,600
3,834
3,998
3
Mercury
533
503
0.020
23.0
2.71
2.87
3
Silver
560
520
0.269
97.9
18.3
19.2
3
Zinc
1,117
1,117
14.3
21,800
3,268
3,416
4
Arsenic
330
206
0.710
275
18.5
23.1
4
Cadmium
330
289
0.130
148
7.381
9.35
4
Copper
204
204
5.60
283
36.7
41.4
4
Lead
330
330
4.80
12,100
276
361
4
Mercury
204
96
0.020
4.80
0.588
0.753
4
Silver
204
94
0.240
22.8
2.25
2.86
4
Zinc
330
330
10.2
9,100
626
736
5
Arsenic
52
52
5.90
83.4
35.8
40.1
5
Cadmium
52
52
2.10
28.0
15.2
16.6
5
Copper
52
52
21.4
144
48.9
54.3
5
Lead
52
52
54.7
3,500
660
777
5
Mercury
52
29
0.110
0.780
0.362
0.423
5
Silver
52
33
0.540
4.70
1.72
2.02
5
Zinc
52
52
441
6,500
2,574
2,825
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-98
Table 7.2-4
Chemicals of Potential Ecological Concern
Aquatic Surface Water - Dissolved Metals
Minimum
Miiximum
Number of
Number ol'
Di'U'Clcd.
Dok'Ck'd.
Mciin.
<)>'•/„ i( i.
CSM I nil
(hi-miciil
Siimplcs
lkkc lions
MS/1-
HK/I.
HB/I.
of Mi'iin. usi/l.
1 &2
Cadmium
2,321
1,878
0.020
408
10.7
11.3
1 &2
Copper
486
153
0.100
260
5.18
8.02
1 &2
Lead
2,304
1,825
0.001
578
21.4
22.8
1 &2
Zinc
2,342
2,195
0.101
17,300
1,487
1,561
3
Cadmium
182
178
0.020
4.80
1.96
2.05
3
Copper
3
2
1.10
14.0
7.550
48.3
3
Lead
181
178
1.50
22.0
6.64
7.06
3
Zinc
182
181
78.0
920
342
360
4
Cadmium
31
4
2.70
3.20
2.95
3.19
4
Copper
7
6
1.70
18.0
12.2
17.0
4
Lead
26
4
1.00
1.01
1.00
1.01
4
Zinc
31
9
1.00
13.0
5.18
7.93
5
Cadmium
72
21
0.120
1.00
0.784
0.917
5
Copper
6
3
0.560
1.50
1.02
1.81
5
Lead
73
38
0.340
1.20
0.949
0.992
5
Zinc
72
68
1.00
92.0
48.5
53.8
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-99
Table 7.2-5
Chemicals of Potential Ecological Concern
Aquatic Surface Water - Total Metals
Minimum
Miiximum
Number of
Number ol'
Di'U'Clcd.
Dok'Ck'd.
Mciin.
<)>'•/„ i( i.
CSM I nil
(hi-miciil
Siimplcs
lkkc lions
MS/1-
HK/I.
HB/I.
ol' Mi'iin. usi/l.
1 &2
Cadmium
2,179
1,809
0.050
407
11.0
11.6
1 &2
Copper
460
173
0.160
310
6.92
10.5
1 &2
Lead
2,217
1,946
0.060
4,260
74.0
82.9
1 &2
Zinc
2,213
2,083
0.940
18,000
1,568
1,646
3
Cadmium
89
88
0.890
21.0
2.64
3.14
3
Copper
7
5
1.40
11.0
7.28
10.7
3
Lead
89
88
2.50
430
39.1
50.6
3
Zinc
88
87
120
690
354
378
4
Cadmium
27
4
4.00
6.00
4.50
5.68
4
Copper
7
1
2.40
2.40
2.40
NM
4
Lead
24
2
0.170
4.80
2.49
17.1
4
Zinc
28
19
1.10
60.0
20.1
27.4
5
Cadmium
34
9
0.160
0.460
0.284
0.361
5
Copper
6
3
0.790
2.30
1.60
2.88
5
Lead
65
63
0.510
8.00
2.24
2.56
5
Zinc
60
60
7.20
100
51.1
56.8
NM - not measured
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-100
Table 7.2-6
COEC Concentrations for Soil (mg/kg) Protective for Terrestrial Biota"
Ansilt Ics
Soil liiolii1'
Population/
C oniinnnit\
ln(li\ idiiiil/
NOAF.I.-hsisecl
Wildlife1'
Populiilion/
I.OAl.l.-biisi'd
Populiilion/
l.l)2ll-h;iso(l
'Xllli Perec
1 ppcr IJiisin'
mile of Soil-Sediiiieiil 1
Lowei' liiisiu'1
tiickui'oiiud
Spokiiuc Ri\cr'
Arsenic
16.8
14
67
40
22
12.6
9.34
Cadmium
10
9.8
105
386
2.7
0.678
0.72
Copper
100
496
751
1,021
53
25.2
23.9
Lead
450
2.5
159
522
171
47.3
14.9
Zinc
106
27
434
261
280
97.1
66.4
a Birds and mammals occurring in upland, agricultural, and riparian habitats; terrestrial plants and invertebrates; and soil processes.
b Based on various lines of evidence available for evaluation (such as comparisons to single-chemical laboratory toxicity studies;
toxicity testing using soil, sediment, or water from the Coeur d'Alene Basin; and field studies in the Basin).
0 Gott and Cathrall (1980)
dUSEPA (200 lh)
e WDOE (1994)
Notes:
ED20 - effective dose - 20 percent response
LOAEL - lowest observed adverse effect level
NOAEL - no observed adverse effect level
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-101
Table 7.2-7
COEC Concentrations for Sediment (mg/kg) Protective for Aquatic Birds and Mammals"
Aiiiil.Mcs
l.\;ilu;ik'(l
lndi\ idiiiil/
NOAII.-hiisod
Wildlife1'
Population/
1.OA I.I.-bused
Population/
l-:i)20-hiised
Sile-speeifie
liuli\ idiiiil-le\el
Proleeli\e ( one.
for W iilei'low I1'
Willi Pereei
I pper IJ;isin'
ilile of Soil-sediiiienl
Lower IJiisin'1
liiiekui'ound
Spokiine Ri\er'
Arsenic
54
222
138
NA
22
12.6
9.34
Cadmium
11.7
173
664
NA
2.7
0.678
0.72
Copper
1,606
2,157
2,209
NA
53
25.2
23.9
Lead
3.65f
249f
718f
93.3s
171
47.3
14.9
Mercury
0.2
2.5
7
NA
0.3
h
0.032
Zinc
5.3
519
390
NA
280
97.1
66.4
a Birds and mammals occurring in palustrine, lacustrine, and riverine habitats.
b Based on various lines of evidence available for evaluation (such as comparisons to single-chemical laboratory toxicity studies;
toxicity testing using soil, sediment, or water from the Coeur d'Alene Basin; and field studies in the Basin).
0 Gott and Cathrall (1980)
dUSEPA (200 lh)
e WDOE (1994)
f For comparison, Beyer et al. (2000) derived a waterfowl no-effect concentration of 24 mg/kg and a lowest-effect concentration of 530 mg/kg and concluded
that waterfowl mortality would occur if concentrations exceed 1,800 mg/kg.
810th percentile of individual-level sediment PRGs calculated for tundra swans, Canada geese, mallards, and wood ducks.
h Mercury was not measured in lower Basin sediment samples. Therefore, a background concentration could not be calculated.
Notes:
ED20 - effective dose - 20 percent response
LOAEL - lowest observed adverse effect level
NOAEL - no observed adverse effect level
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-102
Table 7.2-8
COEC Concentrations for Surface Water Protective for Aquatic Organisms
An;il\Ics
Acnlc Conccn(r;i(inns (u^/l.)1'
Chronic Cnnccnlriilinns u
Si/1.)1'
A(|iiiilic I'liinl - Lowest
Chronic Y;ilnc
IhirdiK'ss-iidjusk'd \ ;ilncs
Iliii'dncss-iKljiislcd \ .lines
10
25
30
50
100
10
25
30
50
100
Cadmium
0.21a
0.52
0.62
1.0
2.0
0.049a
0.094a
0.1 la
0.15a
0.25a
2
Copper
1.5a
3.6
4.3
7
13
1.3a
2.7
3.2
5.0
9.0
1
Lead
4.9
13.9
17
30
65
0.2a
0.54a
0.66a
1.2
2.5
500
Zinc
16.7a
36.2
42
65
117
16.7a
36.2
43
66
118
30
a Background surface water concentrations are greater than the hardness-adjusted protective values in certain locations and selected background statistical
percentiles. See Table 2-14 of USEPA (2001a) for specific areas where background concentrations may exceed the protective concentration.
National Ambient Water Quality Criteria for copper, lead, and zinc as published in the National Recommended Water Quality Criteria - Correction, EPA
822-ZZ-99-001, April, 1999. The National Ambient Water Quality Criteria for cadmium as published on April 12, 2001, 66 FR 18935.
Note:
Hardness values (10, 25, 30, 50, and 100) are mg/L CaC03
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-103
Table 7.2-9
COEC Concentrations for Sediment Protective for Aquatic Organisms
AiiiiMcs
l.\;ilu;ik'(l
COr.C Conmilriilions (nig/kg (l\\)
( SM I nils 1 iind 2
( SM I nils 3 iind 4
( SM I nil 5
Arsenic
22
13
9.3
Cadmium
2.7
0.68
0.72
Copper
53
28a
28a
Lead
171
47
35a
Mercury
0.3
0.17a
0.17a
Silver
1.1
0.73a
0.73a
Zinc
280
00
as
00
as
a Concentrations based on toxicity reference values; other protective concentrations default to background
concentrations for those portions of the Basin.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-104
Table 7.2-10
Protective Goals for Physical and Biological Characteristics
Ph\siciil
Chiii'iiclci'islic
(SMI nil
r.coloiik'ill (lOills
Kipiiriiin ll;il)il;il
llabiial sinlabilil\ index
1
llabiial sinlabilil\ index lor die riparian liabilal llial is cillicr wiihin
the range of historical conditions prior to mining activities or within
the range of conditions currently found in selected reference areas
Spatial distribution and
connectivity
1
Spatial distribution and connectivity of riparian habitat that is either
within the range of historical conditions prior to mining activities or
within the range of conditions currently found in selected reference
areas
Ki\i-riiH- lliihiliil
Bank stability
1 and 2
Bank stability that is either within the range of historical conditions
prior to mining activities or within the range of conditions currently
found in selected reference areas
Substrate composition
and mobility
1 and 2
Substrate composition and mobility that is either within the range of
historical conditions prior to mining activities or within the range of
conditions currently found in selected reference areas
Water temperature
1 and 2
Water temperature that is either within the range of historical
conditions prior to mining activities or within the range of conditions
currently found in selected reference areas
Spatial distribution and
connectivity
1 and 2
Spatial distribution and connectivity of riverine habitat that is either
within the range of historical conditions present in the basin or within
the range of conditions currently found in selected reference areas
Total suspended solids
3
Total suspended solids that are either within the range of historical
conditions prior to mining activities or within the range of conditions
currently found in selected reference areas
l.iicuslriiK* lliihiliil
Sediment deposition
rate
4
Sediment deposition rate that is either within the range of historical
conditions prior to mining activities or within the range of conditions
currently found in selected reference areas
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-105
Table 7.2-11
Summary of Results From the Coeur d'Alene Basin Ecological Risk Assessment
Rm-plor
T\ |H'
Number of
Rm-plors
I-.\;iIii;iK'(I
Lines of l'.\ idciico
Risk lo Receptors
COPK.C Posin» Risk
<(OPIX s = As. ( (1. ( u. Ph. Il». /id
Rcceplors
with No
Idcnliried
Risk
Arciis « illi No
Iriciilirk'ri
Risk
Birds
24
Single-chemical external
exposure, single-chemical
internal exposure (blood),
single-chemical internal
exposure (liver or kidney),
ambient toxicity tests,
biological surveys
21 of 24 receptors showed risk
from at least one metal,
maximum LOAEL-based HQ for
Pb=387 (spotted sandpiper), HQ
forZn=35 (song sparrow), HQ
for Cd=6.12 (song sparrow)
Pb followed by Zn, then Cd and Cu
pose greatest risks; risks from Hg are
minimal; risks from As are absent; at
least one COPEC in almost every CSM
Unit or segment presented a risk for all
but three avian species
Osprey, bald
eagle,
northern
harrier
Beaver and
Prichard
Creeks in CSM
Unit 1
Mammals
18
Single-chemical external
exposure, single-chemical
internal exposure (liver or
kidney), ambient toxicity test
12 of 18 receptors showed risk
from at least 1 metal; maximum
ED20-based HQ for Zn=25.5
(masked shrew), HQ for As=4.4
(muskrat), HQ for Cu=1.55
(masked shrew)
Although no one COPEC was the
dominant risk driver, risks from Zn and
Pb were most widely distrbuted,
followed by Cd, As, Hg, and Cu
Fisher,
wolverine,
river otter,
gray wolf,
lynx, beaver
Beaver and
Prichard
Creeks in CSM
Unit 1
Fish and
Other Aquatic
Organisms
13+
Single-chemical toxicity
testing, site-specific toxicity
testing, biological surveys
Risks to survival, growth, and
reproduction of fish and benthic
invertebrates because of
concentrations of metals 10
times that of acute and chronic
ambient water quality criteria in
more than 25 and 50 percent of
samples, respectively, from some
areas
Cd, Cu, Pb, and Zn pose a risk in
surface water to fish and other aquatic
organisms; As, Cd, Cu, Pb, and Zn in
sediment pose a potential risk to fish
and other aquatic organisms
None
identified
No areas
identified
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-106
Table 7.2-11 (Continued)
Summary of Results from The Coeur d'Alene Basin Ecological Risk Assessment
Rm-plor
T\ |H'
Number of
Rm-plors
I-.\;iIii;iK'(I
Lines of l'.\ idciico
Risk lo Receptors
COPK.C Posin» Risk
<(OPIX s = As. ( (1. ( u. Ph. Il». /id
Rcceplors
with No
Idcnliried
Risk
Arciis « illi No
Iriciilirk'ri
Risk
Amphibians
4
Single-chemical toxicity data,
ambient media toxicity tests,
biological surveys
Risk posed to three of four
receptors
Cd, Cu, Pb, and Zn pose risks; Cd and
Pb present individual risk to three
receptors in four locations; Cu presents
individual-level risks at six locations;
Zn presents individual-level risk at
seven locations; Pb presents greatest
risk in upper basin, Cd presented
greatest risk in lower basin, Zn
presents risks throughout
Long-toed
salamander
Big, Moon,
and Prichard
Creeks in CSM
Unit 1
Terrestrial
Plants
6
Single-chemical toxicity data,
ambient media toxicity tests,
biological surveys
All six plant receptors at risk
As, Cd, Pb, Zn, and Cu pose risk to
plants at community or population
level; As, Cd, Pb, and Zn pose risk to
Ute ladies'-tresses in CSM Units 1,2, 3
and 5
None
identified
Beaver and
Prichard
Creeks in CSM
Unit 1
Soil
Invertebrates
1
Single-chemical toxicity data
Receptors at risk
Pb and Zn pose risk in CSM Units 1, 2,
3, and 5; Cd poses risk in Canyon
Creek and Upper South Fork in CSM 1
and all segments of 2, 3, and 5; Cu
poses risk in Big, Canyon, and
Ninemile Creeks and the Upper South
Fork in CSM Unit 1, and in all
segements of Units 2 and 3; As poses
risk in Pine Creek and Upper South
Fork in CSM Unit 1 and in all of CSM
Units 2 and 3
None
identified
Beaver and
Prichard
Creeks in CSM
Unit 1
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-107
Table 7.2-11 (Continued)
Summary of Results from The Coeur d'Alene Basin Ecological Risk Assessment
Rm-plor
T\ pi-
Niimhi-i' of
Km-plors
l-'.\;ilu;ili-(l
l.ini-s of l-'.\ idi-niT
Risk lo Km-plors
COPK.C Posiii" Risk
l(OPIX s = As. Cel. ( u. Ph. II}•. /.id
Km-plors
with No
l(k-nlirii-(l
Risk
Ari-iis « ill) No
l(li-nlirii-(l
Risk
Soil processes
1
Single-chemical toxicity data
Receptors at risk
Pb and Zn pose risk in all segments of
CSM Units 1, 2, and 3; Cd poses risk
in five of six segments in CSM Unit 3;
Cu poses risk in Canyon and Ninemile
Creeks and the Upper South Fork in
CSM Unit 1 and in 2 segments of CSM
Unit 3; As poses risk in CSM Unit 3
None
identified
Beaver and
Prichard
Creeks in CSM
Unit 1
Notes:
NA - not applicable
No soil data were available from the Beaver or Prichard Creek watersheds.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-108
Table 7.2-12
Summary of Results from the Measures of Ecosystem and Receptor Characteristics Analysis in the Coeur d'Alene Ecological
Risk Assessment
\\ IlUTslU'd
Moiisuiv
l.l'M'l Ol
A(l\erso
l.riWMs
Niiluiv ol'SocoikI;m\ 1. fleets
i:\lcnl of A
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-109
Table 7.2-12 (Continued)
Summary of Results from the Measures of Ecosystem and Receptor Characteristics Analysis in the Coeur d'Alene Ecological
Risk Assessment
\\ IlUTslU'd
Moiisuiv
l.l'M'l Ol
A(l\erso
I.ITccls
Niiluiv ol'Si'cnnriiin I.ITccls
lAlcnl of A(l\crso HITccls - \;uT;i(i\c
Ninemile
Creek
Riparian HSI
None to High
Similar conditions to the Canyon Creek watershed
Loss of channel structure inNMSegOl, NMSeg02, and
NMSeg04 due to historic inputs of bedload and tailings
material. Degraded riparian vegetation structure and
high stream temperatures due to lack of shade in
downstream areas of watershed. Ecological
connectivity fragmented by degraded conditions within
the watershed and downstream in Mid-Gradient
SFCDR watershed.
Bank Stability
None to
Moderate
Substrate Composition
and Mobility
Moderate
Temperature
High
Spatial Distribution
and Connectivity
High
Big Creek
Riparian HSI
None to
Moderate
• Historic inputs of contaminated bedload and mine
tailings material to the stream channel.
• Channel destabilization due to inputs of bedload
material and loss of bank vegetation.
• Recovery of riparian vegetation limited in some areas
by tailings pond development and potentially
phytotoxic soils.
• Ecological connectivity fragmented due to extensive
degradation in downstream segments.
Limited mining related impacts in BigCrkSegOl,
BigCrkSeg02, and BigCrkSeg03. More extensive
mining related impacts in lower half of BigCrkSeg04,
including milling facilities and wastepiles, tailings
pond development, and floodplain deposits of
contaminated material. Degraded riparian vegetation
structure in tailings pond areas. Ecological
connectivity of intact headwaters habitats fragmented
by degraded conditions in BigCrkSeg04 and the Mid-
Gradient SFCDR watershed.
Bank Stability
Low
Substrate Composition
and Mobility
Low
Temperature
Low
Spatial Distribution
and Connectivity
High
Moon Creek
Riparian HSI
None to Low
• Historic inputs of contaminated bedload and mine
tailings material to the stream channel.
• Floodplain deposits of hazardous substances in
downstream areas.
Historic mining activities impacted the stream channel
and riparian habitats of the mainstem of Moon Creek
along most of its length. However, stream channel and
riparian vegetation structure appears to have recovered
in many areas. Ecological connectivity of intact
habitats inMoonCrkSegOl and MoonCrkSeg02
Bank Stability
None to Low
Substrate Composition
and Mobility
None
• Bank instability and deposition of fine grained
material in the stream channel.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-110
Table 7.2-12 (Continued)
Summary of Results from the Measures of Ecosystem and Receptor Characteristics Analysis in the Coeur d'Alene Ecological
Risk Assessment
\\ IlUTslU'd
Moiisuiv
l.l'M'l Ol
A(l\erso
I.ITccls
Niiluiv ol'Si'cnnriiin I.ITccls
lAlcnl of A(l\crso HITccls - \;uT;i(i\c
Moon Creek
(continued)
Temperature
None
• Ecological connectivity fragmented due to extensive
degradation in downstream segments.
fragmented by degraded conditions in the Mid-
Gradient SFCDR watershed.
Spatial Distribution
and Connectivity
High
Pine Creek
Riparian HSI
High
• Historic inputs of contaminated bedload and mine
tailings material to the stream channel.
• Floodplain deposits of hazardous substances in
downstream areas.
• Channel destabilization due to inputs of bedload
material and loss of bank vegetation.
• Impaired recovery of riparian vegetation.
• Ecological connectivity fragmented due to extensive
degradation in downstream segments.
Historic mining activities impacted the stream channel
and riparian habitats of PineCrkSegOl (East Fork Pine
Creek) along much of its length, and PineCrkSeg03
below the East Fork. Extensive floodplain and
riparian zone impacts present in these segments.
Remedial actions to reduce contamination and
rehabilitate riparian and channel structure have been
conducted by BLM. Ecological connectivity of intact
habitats fragmented by degraded conditions in the
Mid-Gradient SFCDR watershed.
Bank Stability
None to High
Substrate Composition
and Mobility
Low to
Moderate
Temperature
None
Spatial Distribution
and Connectivity
High
Beaver
Creek
No Measures
Evaluated
~
Insufficient Information available to evaluate risks for
all receptors.
Prichard
Creek
Riparian HSI
Moderate
Bank Stability
Low
Substrate Composition
and Mobility
Low
Temperature
Low
Spatial Distribution
and Connectivity
Moderate
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-111
Table 7.2-12 (Continued)
Summary of Results from the Measures of Ecosystem and Receptor Characteristics Analysis in the Coeur d'Alene Ecological
Risk Assessment
\\ IlUTslU'd
Moiisuiv
l.l'M'l Ol
A(l\erso
I.ITccls
Niiluiv ol'Si'cnnriiin I.ITccls
lAlcnl of A(l\crso HITccls - \;uT;i(i\c
MidGradient
SFCDR
Riparian HSI
High
• Extensive deposits of contaminated jig and floatation
mining tailings material present in floodplains and
riparian areas.
• Channel destabilization due to inputs of bedload
material and loss of bank vegetation.
• Recovery of riparian vegetation limited in some areas
by phytotoxic levels of hazardous substances in
mining related floodplain deposits.
• Degraded riparian and riverine habitat conditions
throughout MidGradSegOl and MidGradSeg02
contribute to fragmented ecological connectivity.
Floodplain deposits of jig and floatation era mine
tailings present in depositional areas throughout the
mid-gradient SFCDR. Loss of stabilizing riparian
vegetation from phytotoxic effects, and large historic
inputs of bedload material contribute to channel and
substrate instability in the stream system. Degraded
riparian and riverine structure and physical function
throughout MidGradSegOl and MidGradSeg02
contribute to fragmented ecological connectivity
throughout the watershed.
Bank Stability
Moderate to
High
Substrate Composition
and Mobility
Moderate
Temperature
High
Spatial Distribution
and Connectivity
High
North Fork
Coeur
d'Alene
River
Riparian HSI
None
Bank Stability
Not Rated
Substrate Composition
and Mobility
Not Rated
Temperature
Moderate
Spatial Distribution
and Connectivity
None
Mainstem
Coeur
d'Alene
River
Riparian HSI
None
Bank Stability
None
Substrate Composition
and Mobility
Not Rated
Temperature
None
Spatial Distribution
and Connectivity
Not Rated
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-112
Table 7.2-12 (Continued)
Summary of Results from the Measures of Ecosystem and Receptor Characteristics Analysis in the Coeur d'Alene Ecological
Risk Assessment
\\ IlUTslU'd
Moiisuiv
l.l'M'l Ol
A(l\erso
1. fleets
Niiluiv ol'Si'cnnriiin I.ITccls
lAlcnl of A(l\crsc HITccls - \;uT;i(i\c
Lower
Coeur
d'Alene
River
Riparian H SI
Not Rated
• Extensive deposits of contaminated jig and floatation
mining tailings material present in sediments on the
river bottom and in lateral lakes and wetlands, and on
the river bank and floodplain.
• Degraded channel stability due to extensive bedload
inputs.
• Recovery of bank and riparian vegetation possibly
limited by phytotoxic effects.
• Recovery of bank and riparian vegetation possibly
limited by phytotoxic effects.
• Extensive bank erosion contributes to high levels of
suspended solids and elevated sediment deposition
rates.
Deposits of contaminated material along 260,000 feet
(49 miles) of shoreline, averaging approximately 90
feet in width (CSM segments LCDRSeg02-
LCDRSeg06). Actively eroding streambank
identified along 57,900 feet (11 miles) of shoreline in
all CSM segments, the majority associated with
contaminated deposits.
Bank Stability
Not Rated
Suspended Solids
Moderate
Sediment Deposition
Rate
Low to High
Coeur
d'Alene
Lake
Sediment Deposition
Rate
None to High
Core sampling locations at the mouth of the Coeur
d'Alene River and approximately 2.25 miles to the
NW (CDALakeSeg02) indicate deposition rates
corresponding to moderate to high adverse effects.
All other locations throughout CDALakeSeg02
indicate no adverse effects. One location at the
northern end of CDALakeSegOl indicated deposition
rates having a low level of adverse effects. The
southern end of CDALakeSegOl and CDALakeSeg03
were used as reference areas.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 7.0
Page 7-113
Table 7.2-12 (Continued)
Summary of Results from the Measures of Ecosystem and Receptor Characteristics Analysis in the Coeur d'Alene Ecological
Risk Assessment
\\ IlUTslU'd
Moiisuiv
l.l'M'l Ol
A(l\erso
I.ITccls
Niiluiv ol'Si'cnnriiin I.ITccls
lAUiil of A«l\crso K.ITciis - \;uT;i(i\c
Upper
Spokane
River
Sediment Deposition
Rate
None
Due to lack of adverse effects in areas of Coeur
d'Alene Lake away from the mouth of the Coeur
d'Alene River, no adverse effects are expected in the
Spokane River
Notes:
HSI - Habitat Suitability Index
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-1
8.0 REMEDIAL ACTION OBJECTIVES
Remedial action objectives (RAOs) provide a general description of the goals of the overall
cleanup. RAOs have been developed for the protection of human health and ecological
receptors. The Selected Remedy provides prioritized actions toward achieving the RAOs.
8.1 HUMAN HEALTH
The RAOs for human health protection are shown in Table 8.1-1. The primary RAOs for the
selected human health remedy are designed to:
• Reduce human exposure to lead-contaminated soils, sediments, and house dust
exceeding health risk goals particularly in children up to 84 months of age
• Reduce human exposure to soils and sediments that would exceed a cancer risk of
one in ten thousand
• Reduce ingestion of groundwater or surface water withdrawn or diverted from a
private, unregulated source that contains COCs exceeding drinking water
standards and risk-based levels11 (The drinking water standards are shown in
Table 8.1-2.)
8.2 ECOLOGICAL
The RAOs developed for ecological protection are shown in Table 8.2-1. Overall, the RAOs are
designed to:
• Return the rivers and tributaries to conditions that will fully support healthy fish
and other aquatic receptors, with an emphasis on native species, including
sensitive native fish such as the westslope cutthroat trout and the bull trout (listed
as "threatened" under the ESA).
• Return the wetland, lake, riparian, riverine, and upland areas to conditions
protective of waterfowl, migratory birds, and other plants and animals that live in
these areas.
11 The State of Idaho has adopted the federal drinking water standards for the chemicals of potential concern by
reference (IDAPA 58.01.08.050).
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-2
The RAOs are long-term goals that were used to develop the comprehensive ecological
alternatives that are described in Section 9, but are not the objectives of the remedy selected in
this ROD. The Selected Remedy establishes benchmarks (actions and criteria), which are near-
term objectives that will serve as landmarks and measurements to evaluate the progress of the
remedy toward achievement of the long-term goals. The Selected Remedy identifies prioritized
actions to address environmental risks in the Upper Basin and Lower Basin. The benchmarks
identified for the Selected Remedy are discussed in Section 12 and shown in Table 12.2-1.
Potential cleanup criteria for surface water are set forth in the Idaho Water Quality Standards and
Wastewater Treatment Requirements, the Washington Water Quality Standards, tribal standards,
or federal criteria, which have been established through the Clean Water Act to protect aquatic
organisms. These standards and criteria were drivers for development of the comprehensive
alternatives and for identification of the priority actions included in the Selected Remedy. State,
tribal, and federal standards and criteria for protection of aquatic life in surface water are listed in
Tables 8.2-2, 8.2-3, and 8.2-4.12
40 CFR 131.11 provides states the opportunity to adopt site-specific water quality criteria (SSC)
that are "...modified to reflect site specific conditions." The State of Idaho promulgated SSC for
cadmium, lead, and zinc in the flowing waters of the Upper Basin as a permanent rule in March
2002 (IDAPA 58.01.02.284). The status of the SSC as potential ARARs for cleanup in the Basin
is discussed in Section 13.2.
Table 7.2-8 presents concentrations of metals in surface water that represent the lowest chronic
effects levels of metals that may affect aquatic plants. However, these effects levels for plants
are screening-level benchmarks. The AWQC also take into account the protection of aquatic
plants. Therefore, the AWQC are considered adequately protective for aquatic plants and
animals.
Protection of certain species is required by the MBTA and the ESA. In order to comply with
these ARARs, cleanup criteria will be protective of these species within the areas where they
may occur. Based on the EcoRA, 19 of 22 migratory bird species evaluated are at risk. These
species are representative of hundreds of species that are similarly exposed. Protection of
MBTA and ESA species was a driver for development of the comprehensive alternatives and for
identification of the priority actions for soil, sediment, and surface water included in the Selected
Remedy.
12 Cleanup levels would not be less than background concentrations of metals in surface water.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-3
As described in Section 12.2.3, Benchmark Cleanup Criteria, a benchmark cleanup criterion of
530 mg/kg for lead in Lower Basin soil and sediment has been selected for implementation of the
Selected Remedy. This criterion may be revised as additional information becomes available to
ensure protectiveness of the remedy.
In riparian areas where remedial actions are conducted (e.g., banks and tributaries), risks to
riparian receptors will be mitigated using removal and replacement with clean soil or capping
with clean soil to isolate contaminants and reduce or eliminate exposure pathways.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-4
Table 8.1-1
Remedial Action Objectives for Protection of Human Health
l-'n\ irnnmcnliil
Mi'rii.i
KciiK'riiiil Action ()hjcc(i\os
Soils, Sediments
and Source
Materials
Reduce mechanical transportation of soil and sediments containing unacceptable levels of
contaminants into residential areas and structures.
Reduce human exposure to soils, including residential garden soils, and sediments that have
concentrations of contaminants of concern greater than selected risk-based levels for soil. (As
described in Sections 7 and 12 of this ROD.)
House Dust
Reduce human exposure to lead in house dust via tracking from areas outside the home and
air pathways, exceeding health risk goals.
Groundwater and
Surface Water as
Drinking Water
Reduce ingestion by humans of groundwater or surface water withdrawn or diverted from a
private, unregulated source, used as drinking water, and containing contaminants of concern
exceeding drinking water standards and risk-based levels for drinking water.
Aquatic Food
Sources
Reduce human exposure to unacceptable levels of contaminants of concern via ingestion of
aquatic food sources (e.g., fish and water potatoes).
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-5
Table 8.1-2
ARARs for Drinking Water
M cl ill
MCI." or II \ Hii/I.
Arsenic
10
Cadmium
5
Lead
TT3;
Action Level =15
1 Max i inn in Contaminant Level (MCL) - The highest level of a contaminant that is allowed in drinking water. MCLs
are set as close to MCL goals as feasible using the best available treatment technology and taking cost into
consideration.
treatment technique (TT) - A required process intended to reduce the level of a contaminant in drinking water.
3Lead is regulated by a treatment technique that requires systems to control the corrosiveness of their water. If more
than 10% of tap water samples exceed the action level, water systems must take additional steps.
Note:
(ag/L - micrograms per liter
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-6
Table 8.2-1
Remedial Action Objectives for Protection of Ecological Receptors
Suhjocl
Kcmodiiil Action ()hjccli\c
Ecosystem and
physical structure
and function
Remediate soil, sediment, and water quality and mitigate mining impacts in habitat areas to
be capable of supporting a functional ecosystem for the aquatic and terrestrial plant and
animal populations in the Coeur d'Alene Basin.
Maintain (or provide) soil, sediment, and water quality and mitigate mining impacts in
habitat areas to be supportive of individuals of special-status biota that are protected under
the Endangered Species Act and the Migratory Bird Treaty Act.
Soil, sediment, and
source materials
Prevent ingestion of arsenic, cadmium, copper, lead, mercury, silver, and zinc by ecological
receptors at concentrations that result in unacceptable risks.
Reduce loadings of cadmium, copper, lead, and zinc from soils and sediments to surface
water so that loadings do not cause exceedances of potential surface water quality ARARs.
Prevent transport of cadmium, copper, lead, and zinc from soils and sediments to
groundwater at concentrations that exceed potential surface water quality ARARs.
Prevent dermal contact with arsenic, cadmium, copper, lead, mercury, silver, and zinc by
ecological receptors at concentrations that result in unacceptable risks.
Mine water,
including adits,
seeps, springs, and
leachate
Prevent discharge of cadmium, copper, lead, and zinc in mine water, including adits, seeps,
springs, and leachate to surface water at concentrations that exceed potential surface water
quality ARARs.
Surface water
Prevent ingestion of cadmium, copper, lead, and zinc by ecological receptors at
concentrations that exceed potential surface water quality ARARs.
Prevent dermal contact with cadmium, copper, lead, and zinc by ecological receptors at
concentrations that exceed potential surface water quality ARARs.
Groundwater
Prevent discharge of groundwater to surface water at concentrations of cadmium, copper,
lead, and zinc that exceed potential surface water quality ARARs.
Note:
The Selected Remedy is designed to achieve the benchmarks (actions and criteria) shown in Table 12.2-1. The
Selected Remedy for ecological protection provides prioritized actions toward achieving the RAOs.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-7
Table 8.2-2
Water Quality Standards and Criteria for Protection of Aquatic Life in Surface Water in the Upper Basin
(CSM Units 1 and 2)
Metal
IIPA-Annrowd Idaho Water Qualil\ Standards'"
Idaho Site-Specific Criteria'1'1
National Ambient \\ ater OnalilN Criteria1'1'
Acute
Ch ronic
Acute
Ch ronic
Acute
Chronic
1 lardness1'
30
50
100
30
50
100
30
50
100
30
50
100
30
50
100
30
50
100
Cadmium
1.0
1.7
~
0.42
0.62
1.0
0.61
1.0
2.1
0.42
0.62
1.0
0.62
1.0
2.0
0.11
0.15
0.25
Copper
5.5
8.9
17
4.1
6.3
11
5.5
8.9
17
4.1
6.3
11
4.3
7.0
13
3.2
5.0
9.0
Lead
17
30
65
0.66
1.2
2.5
80
129
248
9.1
15
28
17
30
65
0.66
1.2
2.5
Zinc
41
64
114
38
58
105
88
123
195
88
123
195
42
65
117
43
66
118
'Standards and criteria in micrograms per liter (ng/L)
bHardness in milligrams of calcium carbonate per liter (mgCaC03/L)
cEPA-approved Idaho Water Quality Standards, IDAPA 58.01.02.210, as submitted by Idaho to EPA by May 30, 2000.
¦"Idaho site-specific criteria (SSC) for cadmium, lead, and zinc, IDAPA 58.0102.284, as adopted by Idaho on March 15, 2002. Copper criteria apply statewide (IDAPA
58.0102.210).
'National Ambient Water Quality Criteria for copper, lead, and zinc as published in the National Recommended Water Quality Criteria - Correction, EPA 822-ZZ-99-001, April 1999. The National
Ambient Water Quality Criteria for cadmium as published on April 12, 2001, 66 FR 18935.
Notes:
Idaho and national guidelines set a maximum hardness to be used in calculating the criteria at 400 mg/L.
Equations used to calculate water quality standards and criteria
Melal
Aculc criteria equation
Chronic criteria equation
Cadmium (EPA-Approved State Standard)
{1.136672-(ln(H)*0.041838)} *{exp(1.128*ln(H)-3.828)}
{1.101672-(ln(H)*0.041838)} * {exp(0.7852 *ln(H)-3.49)}
Cadmium (State SSC)
0.973 *exp( 1.0166 *ln(H)-3.924)
{1.101672-(ln(H)*0.041838)}*{exp(0.7852*ln(H)-3.49)}
Cadmium (National AWQC)
{1.136672-(ln(H)*0.041838)} *{exp(l.0166 *ln(H)-3.924)}
{1.101672-(ln(H)*0.041838)}*{exp(0.7409*ln(H)-4.719)}
Copper (EPA-Approved State Standard and State
SSC)
0.96 *exp(0.9422 *ln(H)-1.464)
0.96 *exp(0.8545 *ln(H)-1.465)
Copper (National AWQC)
0.96 *exp(0.9422 *ln(H)-1.700)
0.96 *exp(0.8545 *ln(H)-1.702)
Lead (EPA-Approved State Standard and National
AWQC)
{1,46203-(ln(H)*0.145712)} *{exp(l .273 *ln(H)-l .46)}
{1,46203-(ln(H)*0.145712)} * {exp(l ,273*ln(H)-4.705)}
Lead (State SSC)
exp(0.9402*ln(H)H. 1834)
exp(0.9402 *ln(H)-0.9875)
Zinc (EPA-Approved State Standard)
0.978 *exp(0.8473 *ln(H)4-0.8604)
0.986 *exp(0.8473 *ln(H)+0.7614)
Zinc (State SSC)
exp(0.6624 *ln(H)4-2.223 5)
Same as acute
Zinc (National AWQC)
0.978 *exp(0.8473 *ln(H)+0.884)
0.986*exp(0.8473*ln(H)H).884)
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-8
Table 8.2-3
Water Quality Standards and Criteria for Protection of Aquatic Life in the Lower Basin, Coeur d'Alene Lake,
and Spokane River Within Idaho (CSM Units 3, 4, and 5)
Metal
r.PA-Approw'd Idaho Water Qu;ilil\ Standards'"'
Coeur d'Alene Tribe Water Qu;ilil\ Standards1'1
National Ainhient W ater Qu;ilil\ Criteria ''1'
Acute
Chronic
Acute
Chronic
Acute
Chronic
1 lardness1'
20
30
50
20
30
50
20
30
50
20
30
50
20
30
50
20
30
50
Cadmium
0.82
1.0
1.7
0.37
0.42
0.62
0.65
1.0
1.7
0.31
0.42
0.62
0.42
0.62
1.0
0.080
0.11
0.15
Copper
4.6
5.5
8.9
3.5
4.1
6.3
3.7
5.5
8.9
2.9
4.1
6.3
2.9
4.3
7.0
2.3
3.2
5.0
Lead
14
17
30
0.54
0.66
1.2
11
17
30
0.42
0.66
1.2
11
17
30
0.42
0.66
1.2
Zinc
35
41
64
32
38
58
29
41
64
27
38
58
30
42
65
30
43
66
Standards and criteria in micrograms per liter (ng/L)
bHardness in milligrams of calcium carbonate per liter (mgCaC03/L)
cEPA-approved Idaho Water Quality Standards, IDAPA 58.01.02.210, as submitted by Idaho to EPA by May 30, 2000.
dTribal water quality standards apply only within reservation lands and water bodies.
TSTational Ambient Water Quality Criteria for copper, lead, and zinc as published in the National Recommended Water Quality Criteria - Correction, EPA 822-ZZ-99-001, April
1999. The National Ambient Water Quality Criteria for cadmium as published on April 12, 2001, 66 FR 18935.
Notes:
Idaho, Coeur d'Alene Tribe, and national guidelines set a maximum hardness to be used in calculating the criteria at 400 mg/L. Statewide Idaho water quality standards also set a
minimum hardness to be used in calculating the criteria at 25 mg/L. If hardness is <25 mg/L within reservation lands and water bodies, tribal standards are more stringent.
Equations used to calculate water quality standards and criteria
Metal
Acule criteria equation
Chronic criteria equation
Cadmium (EPA-Approved State Standard and
Tribe)
{1.136672-(ln(H)*0.041838)} *{exp(1.128*ln(H)-3.828)}
{1.101672-(ln(H)*0.041838)} * {exp(0.7852 *ln(H)-3.49)}
Cadmium (National AWQC)
{1.136672-(ln(H)*0.041838)} *{exp(1.0166*ln(H)-3.924)}
{1.101672-(ln(H)*0.041838)}*{exp(0.7409*ln(H)-4.719)}
Copper (EPA-Approved State Standard and Tribe)
0.96 *exp(0.9422 *ln(H)-1.464)
0.96 *exp(0.8545*ln(H)-l.465)
Copper (National AWQC)
0.96 *exp(0.9422 *ln(H)-1.700)
0.96 *exp(0.8545 *ln(H)-1.702)
Lead (EPA-Approved State Standard, Tribe, and
National AWOC")
{1,46203-(ln(H)*0.145712)} * {exp(l ,273*ln(H)-l .46)}
{1.46203-(ln(H)*0.145712)} *{exp(l.273 *ln(H)-4.705)}
Zinc (EPA-Approved State Standard and Tribe)
0.978 *exp(0.8473 *ln(H)+0.8604)
0.986*exp(0.8473*ln(H)H).7614)
Zinc (National AWQC)
0.978 *exp(0.8473 *ln(H)4-0.884)
0.986 *exp(0.8473 *ln(H)+0.884)
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 8.0
Page 8-9
Table 8.2-4
Water Quality Standards and Criteria for Protection of Aquatic Life in Surface Water in the Spokane River
Within Washington (CSM Unit 5)
Metal
F.PA-Appnued Washington Water Qu;ilil\
Standards1'1'
Spokane Tril>c Walcr Qualil\ Standards'1''1
National Amhicnt Waler Qualil\ Criteria11'1'
Acute
Chronic
Acute
Chronic
Acute
Chronic
1 lardness1'
30
50
100
30
50
100
30
50
100
30
50
100
30
50
100
30
50
100
Cadmium
1.0
1.7
3.7
0.42
0.62
1.0
1.0
1.7
3.7
0.42
0.62
1.0
0.62
1.0
2.0
0.11
0.15
0.25
Copper
5.5
8.9
17
4.1
6.3
11
4.3
7.0
13
3.2
5.0
9.0
4.3
7.0
13
3.2
5.0
9.0
Lead
17
30
65
0.66
1.2
2.5
17
30
65
0.66
1.2
2.5
17
30
65
0.66
1.2
2.5
Zinc
41
64
114
38
58
105
41
64
114
38
58
105
42
65
117
43
66
118
Standards and criteria in micrograms per liter (|xg/L)
^Hardness in milligrams of calcium carbonate per liter (mgCaC03/L)
cEPA-approved Washington Water Quality Standards, WAC 173-201A-040, as submitted by Washington to EPA by May 30, 2000.
dTribal water quality standards apply only within reservation lands and water bodies.
National Ambient Water Quality Criteria for copper, lead, and zinc as published in the National Recommended Water Quality Criteria - Correction, EPA 822-ZZ-99-001, April
1999. The National Ambient Water Quality Criteria for cadmium as published on April 12, 2001, 66 FR 18935.
Equations used to calculate water quality standards and criteria
Melal
Aculc criteria equation
Chronic criteria equation
Cadmium (EPA-Approved Stale Standard
and Tribe)
[I.I 36672-(ln(l lfO.041838)} * [e\p( 1.128*ln(I l)-3.828)j
[ 1.101672-(ln(l lfO.041838)! * !e\p(0.7852*ln(I I)-3.49)j
Cadmium (National AWQC)
{1.136672-(ln(H)*0.041838)} *{exp(l.0166 *ln(H)-3.924)}
{1.101672-(ln(H)*0.041838)}*{exp(0.7409*ln(H)-4.719)}
Copper (EPA-Approved State Standard)
0.96 *exp(0.9422 *ln(H)-1.464)
0.96 *exp(0.8545 *ln(H)-1.465)
Copper (Tribe and National AWQC)
0.96 *exp(0.9422 *ln(H)-1.700)
0.96 *exp(0.8545 *ln(H)-1.702)
Lead (EPA-Approved State Standard,
Tribe, and National AWQC)
{1,46203-(ln(H)*0.145712)} *{exp(l .273 *ln(H)-l .46)}
{1,46203-(ln(H)*0.145712)} * {exp(l ,273*ln(H)-4.705)}
Zinc (EPA-Approved State Standard and
Tribe)
0.978 *exp(0.8473 *ln(H)4-0.8604)
0.986 *exp(0.8473 *ln(H)+0.7614)
Zinc (National AWQC)
0.978 *exp(0.8473 *ln(H)+0.884)
0.986 *exp(0.8473 *ln(H)4-0.884)
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9.0 DESCRIPTIONS OF ALTERNATIVES
This section describes the comprehensive alternatives for protection of human health and the
environment that were developed and evaluated in the FS. Human health and ecological
alternatives for the basin were developed, analyzed, and compared following EPA guidance
(USEPA 1988). This section summarizes the components of each of the alternatives, which are
organized as follows:
• Section 9.1. Alternatives for protection of human health in the residential and
community areas of the Upper Basin and Lower Basin
• Section 9.2. Alternatives for protection of ecological receptors in the Upper
Basin and Lower Basin
• Section 9.3. Alternatives for Coeur d'Alene Lake
• Section 9.4. Alternatives for protection of human health and ecological receptors
for the Spokane River between the Washington-Idaho state line and Upriver Dam
The Selected Remedy is described in Section 12. The alternative development process for both
human health and ecological protection included identification of all potentially applicable
technologies and process options; screening of technologies and process options on the basis of
technical implementability only; and evaluation and screening of retained technologies and
process options based on effectiveness, implementability, and cost. The retained process options
were then assembled into alternatives that cover a range of remedial options, including "no
action," as required by the NCP.
The remedial alternatives are not mutually exclusive choices and do not limit the choice of a
remedy. The Selected Remedy can combine elements of the various alternatives, refine or
modify those elements, or add to them. Alternatives are developed and evaluated in the remedy
selection process to the level of detail appropriate to provide information needed to support a
Proposed Plan and ROD. This level of detail is considered a planning level, not a design level.
Remedial actions require appropriate site-specific remedial designs, which may generally include
collection of site-specific chemical, hydrologic, hydraulic, and geotechnical data from areas
identified as requiring cleanup. These areas may include those where previous cleanup actions
have taken place, such as floodplain areas of the UPRR right-of-way or other areas where
previous removal actions have addressed some, but not all, contamination present. Remedial
design and construction (remedial action) are post-ROD activities that are based on the remedy
selected in the ROD.
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Cleanup plans for the Basin have also been developed by the State of Idaho (State of Idaho
Cleanup Plan) and the mining companies (Mining Companies Cleanup Plan). Because the
ecological components of these plans enhance the range of remedial options available to decision
makers, these plans are presented as ecological Alternatives 5 (State of Idaho Cleanup Plan) and
6 (Mining Companies Cleanup Plan), based on interpretation of available documentation. The
human health alternatives include the human health components of these plans, with minor
exceptions, and the State Plan and Mining Companies Plan are not presented as distinct
alternatives for protection of human health.
9.1 HUMAN HEALTH ALTERNATIVES FOR THE COMMUNITY AND
RESIDENTIAL AREAS
Human health alternatives were developed for the primary potential exposure media:
• Soil
• Drinking water
• House dust
• Aquatic food sources
Risk from eating homegrown vegetables is addressed by the yard soil alternatives. The ultimate
effectiveness of the aquatic food sources alternatives would be highly dependent on the
reductions of fish uptake of metals achieved through implementation of ecological remedies.
9.1.1 Soil Alternatives
Soil Alternative SI—No Action
This alternative would leave contaminated soil in place with no change in existing conditions. It
would not remove contaminated soil from residential yards and gardens in the Basin, it would
provide no information, education, or counseling for residents with contaminated yards, and it
would not monitor blood lead levels to evaluate the impacts of continued exposure. The no
action alternative provides a baseline from which to compare the action alternatives.
Soil Alternative S2—Information and Intervention
This alternative would include deed notices, pamphlet distribution, press releases, public
meetings, publicly posted notices, and advisory signs in public areas to both inform the public of
risk mitigation and new risk information and solicit public input and involvement. This
alternative also would include a program similar to the PHD's Lead Health Intervention
Program, which provides personal health and hygiene information to help mitigate exposure to
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contaminants. Services also include biological monitoring, yard and home sampling, and
nursing follow-up services. An institutional controls program that would include local
construction regulations (developed and implemented in conjunction with local zoning, building,
or planning commissions) may also be considered in certain areas if risk conditions warrant.
Soil Alternative S3—Information and Intervention and Access Modifications
In addition to information and intervention, this alternative would include constructing fences or
other barriers around certain areas and providing maintenance to prevent or limit access to
certain areas where risk level and persistency warrant. This alternative is not intended for use at
residential properties.
Soil Alternative S4—Information and Intervention and Partial Removal and Barriers
In addition to information and intervention, this alternative would include removing a limited
amount of contaminated soil and placing clean barriers. Contaminated yards would be excavated
to a typical depth of about 1 foot. Garden areas would be provided with a minimum of 2 feet of
clean fill. In order to mitigate potential exposure pathways, the excavated areas would be
backfilled with clean soils and/or capped. Where appropriate, structure exteriors would be
pressure-washed before remedial measures are performed, to reduce the potential for
recontamination from lead-based paint. Risk would be further reduced by installing visual
markers to delineate the limits of soil removal. In addition to residential yards, common use
areas such as streets, alleys, rights-of-way, and playgrounds would also be candidates for
remediation if soil contamination and exposure risks warrant. This alternative would also
include revegetation and interim dust control during soil excavation. For recreational areas, this
alternative would include site improvements to reduce exposure risks. These would be specific
to individual recreational areas and, in addition to partial soil removal and access restrictions,
could include stabilizing river banks, constructing paved boat ramps and parking areas,
excavating or capping day-use and overnight camping areas, and providing picnic tables.
Soil Alternative S5—Information and Intervention and Complete Removal
In addition to information and intervention, this alternative would include complete removal and
disposal of soil that exceeds action levels. The depth of contaminated soil is expected to vary
considerably within the Basin, but complete removal is considered to be excavation of residential
yard and garden areas to a depth of 4 feet. If warranted, structure exteriors would be pressure-
washed to reduce the potential for recontamination from lead-based paint. This alternative
would include backfilling the properties with clean soil to re-establish site grades and
revegetating the reclaimed ground surface. It would also include interim dust control during soil
excavation. This alternative is not envisioned for recreational areas.
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9.1.2 Drinking Water Alternatives
Drinking Water Alternative W1—No Action
This alternative would leave contaminated drinking water sources in place with no changes in
existing use. It would take no action to prevent exposure to COCs in drinking water, and would
provide no information or education to exposed residents. The no action alternative provides a
baseline from which to compare the action alternatives.
Drinking Water Alternative W2—Public Information
This alternative would include pamphlet distribution, press releases, public meetings, and
publicly posted notices to inform the public of risk mitigation and new risk information and
solicit public input and involvement. This alternative would require an ongoing effort and would
be intended primarily for use at the community level. It is generally not considered feasible for
individual residences, except for raising general awareness of risks.
Drinking Water Alternative W3—Public Information and Residential Treatment
In addition to public information, this alternative would include wellhead filtration (if applicable)
and point-of-use filtration. Filters would be placed at each tap or other point of use in
residences. If possible, a single filter would be placed on the main residence service line to
avoid potential confusion and change-out costs for multiple filters. A change-out program would
be required to ensure that filters are changed on the required schedule.
Drinking Water Alternative W4—Public Information and Alternative Source, Public Water
Utility
In addition to public information, this alternative would include constructing drinking water
conveyances from public water utilities to residences or common-use areas. Information
programs would be used to better inform residents about lead risks from in-home plumbing.
Drinking Water Alternative W5—Public Information and Alternative Source, Groundwater
For properties currently supplied by contaminated water wells or other unregulated sources this
alternative would include (in addition to public information) constructing new wells into a
suitable alternative aquifer, installing necessary appurtenances, and abandoning existing
contaminated wells. The suitability of the alternative aquifer (for example, water yield and
quality) would need to be evaluated before drilling any new wells. After well construction,
groundwater sampling would be conducted to verify that new wells supply water capable of
achieving the RAOs. Subsequent monitoring would also be conducted to ensure continual
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achievement of RAOs. Information programs would be used to better inform residents about
lead risks from in-home plumbing.
Drinking Water Alternative W6—Public Information and Multiple Alternative Sources
This alternative would include public information, in addition to one of the above-described
alternatives, depending on geographic issues. For areas inside water districts, the alternative
would provide individual residences or common areas with a hookup to the existing public
conveyance system. For areas outside water districts (mostly in the tributary gulches), it is
assumed that public water utilities will not be able to provide an alternative water source because
of the annexation and engineering issues of constructing distribution systems; therefore, the
assumed alternative for these areas would be to provide either point-of-use treatment or new
groundwater wells. Alternative W6 would include a survey of residences during remedial design
to determine whether they were served by public water utilities, and to determine residences at
which COCs in drinking water exceed maximum contaminant levels.
9.1.3 House Dust Alternatives
House Dust Alternative D1—No Action
The No Action alternative would leave contaminated house dust in place and would not change
existing conditions. It would take no action to prevent exposure, and provide no information or
education to exposed residents. The no action alternative provides a baseline from which to
compare the action alternatives.
House Dust Alternative D2—Information and Intervention and Vacuum Loan Program/Dust
Mats
This alternative has three major components. First, information and intervention for house dust
would include pamphlet distribution, press releases, public meetings, and publicly-posted notices
to inform the public of remedial actions and to provide exposure education. In addition, public
input and involvement would be sought. This program has been administered as part of the
PHD's Lead Health Intervention Program in the Bunker Hill Box for approximately 15 years and
throughout the basin since 1996. The second component of this alternative would be initiation of
a Vacuum Loan Program similar to the one used in the Bunker Hill Box, which allows residents
to use a heavy-duty vacuum cleaner equipped with high-efficiency particulate air (HEPA) filters.
The third component would be free dust mats for entryways, which would be provided to
residents to reduce tracking exterior dust into the home. Monitoring would also be conducted to
ensure continued achievement of RAOs.
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House Dust Alternative D3—Information and Intervention, Vacuum Loan Program/Dust
Mats, Interior Source Removal, and Contingency Capping/More Extensive Cleaning
In addition to the components of Alternative D2, this alternative would include interior cleaning,
and removing and replacing some household items that are either difficult to clean effectively or
which provide a source for recontamination. Interior cleaning would include a one-time cleaning
of hard surfaces and heating and cooling systems and removal and replacement of major interior
dust sources such as carpet and some soft furniture. In addition, this alternative would consider
crawl spaces, attics, and basements. Contaminated crawl spaces would be capped with a sand or
synthetic cover to prevent generation of dust and tracking of soil into the home. Accessible
attics and basements would also be cleaned. The exact scope of this alternative will depend on
the conditions of each residence. These activities would occur only after exterior sources of
contamination had been permanently remediated, to ensure cost-effectiveness and prevent
recontamination. Based on observations from yard remediation in the Bunker Hill Box, once
exterior yard soil is cleaned up, relatively few homes (a maximum of 20 percent of the homes
that required yard cleanup, or about 100 to 200 homes) are expected to require the additional
interior cleaning provided by Alternative D3. Temporary relocation of residents might be
required during cleaning to protect their safety. Monitoring would also be conducted to ensure
that RAOs continue to be achieved after the Selected Remedy is implemented.
9.1.4 Aquatic Food Sources Alternatives
Aquatic Food Sources Alternative F1—No Action
This alternative would take no action to address the potential human health risk to residents and
tribal members of eating contaminated fish. It would take no action to prevent exposure and
provide no information or education to people likely to consume contaminated fish. The no
action alternative provides a baseline from which to compare the action alternatives.
Aquatic Food Sources Alternative F2—Information and Intervention
In addition to the information and intervention efforts of other alternatives, this alternative would
educate fishermen and other recreational users of the potential health risk of consuming
contaminated fish caught in waterways and wetlands. All printed materials, press releases, and
public meetings developed to inform the public of basin metals issues would include information
about the fish risks, how to reduce exposure, prevention, and other pertinent issues. Fish hazard
information programs would be expanded to the Coeur d'Alene Indian Reservation communities,
as appropriate, to ensure that tribal members are kept informed. Targeted community education
programs would be implemented in Benewah, Kootenai, and Shoshone Counties. A well-
maintained signage program to educate fishermen and other water users of metals hazards would
be implemented at all river/lake access sites and common use areas, including the Coeur d'Alene
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River Trail system corridor. Idaho Department of Fish and Game, Idaho State Parks, USFS, and
BLM field personnel who regularly contact basin fishermen and recreational users would be
trained in metals risk management and supplied with appropriate pamphlets and signs.
Aquatic Food Sources Alternative F3—Information and Intervention and Monitoring
This alternative would build on the efforts of informing and educating fishermen of risks from
consumption of metals-contaminated fish included under Alternative F2. An effort to gain more
fish metals load data from each of the lateral lakes, the South Fork, lower Coeur d'Alene River,
and Coeur d'Alene Lake is the keystone of this alternative. The current limited fish flesh data
from three lateral lakes would be expanded so that lake-specific recommendations and
intervention can be accurately provided to the public. Surface waters and fish species that are
totally free of metals risks would be identified and highlighted. As basin cleanup and mitigation
efforts proceed, periodic resampling would provide valuable effectiveness monitoring data for
biological response to cleaner waters, sediment, and upstream soils. A trained seasonal "river
ranger" program would be instituted to make daily contacts with fishermen and boaters to inform
and educate them of metals hazards and prevention methods. Fishermen would be directed to
lakes or rivers where fish metals risks are known to be the lowest.
9.2 ECOLOGICAL ALTERNATIVES FOR THE UPPER BASIN AND LOWER
BASIN
Six ecological alternatives were developed for the Upper Basin and Lower Basin. These are:
Alternative 1—No Action
Alternative 2—Contain/Stabilize with Limited Removal and Treatment
Alternative 3—More Extensive Removal, Disposal, and Treatment
Alternative 4—Maximum Removal, Disposal, and Treatment
Alternative 5—State of Idaho Cleanup Plan
Alternative 6—Mining Companies Cleanup Plan
Remedial actions were identified for various contamination sources under each of the
alternatives. Table 9.2-1 describes the generalized approach each alternative takes to
remediating source types.
Each alternative consisted of typical conceptual designs (TCDs) that are applied on a site-by-site
basis. Table 9.2-2 presents descriptions of TCDs used with Alternatives 2, 3, and 4. Tables 9.2-
3, 9.2-4, and 9.2-5 present unit costs for these TCDs. Tables 9.2-6 and 9.2-7 present descriptions
and unit costs of TCDs used with Alternatives 5 and 6, respectively. The TCDs associated with
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these alternatives vary in design details from the TCDs used to develop Alternatives 2, 3, and 4.
As a result, the unit costs are different.
Table 9.2-8 presents a summary of the volumes of waste material addressed by each of the
alternatives. Table 9.2-9 summarizes the numbers of acres of waterfowl feeding area
contaminated with lead at concentrations exceeding the LOAEL for waterfowl (530 mg/kg) that
are addressed by each of the alternatives.
For the purpose of comparing the effectiveness of the six alternatives, estimates were made of
the reduction in zinc loads at the completion of remedy implementation (USEPA 2001f). The
estimates were made for the South Fork at Pinehurst and the Coeur d'Alene River at Harrison,
and do not include sources within the Bunker Hill Box. The results are shown in Table 9.2-10.
Alternative 4 is estimated to result in the greatest reduction in zinc load following remedy
implementation: a 73 percent reduction at Pinehurst and a 64 percent reduction at Harrison.
Alternative 3 is predicted to result in about 15 and 11 percent smaller reductions in zinc loads
compared to Alternative 4 at Pinehurst and Harrison, respectively. Alternative 2 is predicted to
result in about a 59 percent smaller reduction in zinc load compared to Alternative 4 at both
Pinehurst and Harrison. Alternatives 5, 6, and 1 result in increasingly smaller reductions in zinc
load.
Alternative 1—No Action
Alternative 1 includes no actions to control exposures of ecological receptors to contaminants.
Risks to fish and other aquatic receptors, birds, and terrestrial receptors would continue to exist
for the foreseeable future.
Alternative 2—Contain/Stabilize with Limited Removal and Treatment
Actions are generally aimed at controlling sources having the highest metal loadings to
groundwater and surface water and the highest levels of ecological exposure. Limited removals
and in-place and on-site waste containment would be used to control ecological and human
exposures and metal transport via erosion and leachate loading to groundwater and surface water.
Bioengineering would be used to provide bank and stream stabilization, control erosion of
contaminated sediments, and support natural recovery of riverine and riparian habitat. Chemical
treatment would be limited to passive treatment of drainage from the adits that are the major
metals loaders and of groundwater collected as part of hydraulic isolation (limited to the Hecla-
Star tailings pounds in Canyon Creek and the Cataldo/Mission Flats dredge spoil area). Residual
risks would be associated with contaminated media left in place or only partially contained.
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Alternative 3—More Extensive Removal, Disposal, and Treatment
Alternative 3 would extend the level of cleanup included under Alternative 2 through the use of
more extensive and effective removal, containment, and treatment, including:
• Regional repositories for disposal of contaminated materials excavated from
source areas in the Upper Basin
• A regional active water treatment plant for treatment of collected groundwater,
leachate, and adit drainage water
• More extensive use of hydraulic isolation, including inaccessible current and
historic 100-year floodplain sediments and additional tailings impoundments in
the Upper Basin
• Comprehensive removal of river bed and bank sediments
A passive treatment pond near the mouth of Canyon Creek is also included as part of
Alternative 3. The pond would be used to reduce metal loadings to the South Fork before
upstream source control was accomplished.
Disposal of materials removed from the Lower Basin (including river banks, levees, and beds;
wetlands; and lateral lakes) would be at a regional repository or by confined aquatic disposal
(CAD).
Alternative 4—Maximum Removal, Disposal, and Treatment
Alternative 4 would include removal of sources to the maximum practical extent with disposal in
regional repositories. It would extend the use of active water treatment, and employ hydraulic
isolation to contain metals within floodplain sediments. Residual risks resulting from
contaminated materials left in place or only partially contained would be minimized to the
greatest extent practicable.
Alternative 5—State of Idaho Plan
Alternative 5, developed by IDEQ, would focus on containing or stabilizing the largest sources
of metals loading to surface water. Alternative 5 includes measures similar to Alternatives 2 and
3; it includes regional repositories and passive water treatment, but does not include an active
water treatment plant. In developing the alternative, IDEQ sought to achieve a balance between
benefit, cost, and impact to the environment in both the long term and short term.
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Alternative 6—Mining Companies Plan
Alternative 6 consists of prioritized actions primarily focused on regrading or removing source
material from water courses to reduce erosion and the potential for contact with surface and
groundwater that could result in leaching and surface water loading. Local areas of
bioengineered and vegetative stream bank stabilization are included. Mine water management
and/or passive treatment are included for four major adits. Regional repositories and active
water treatment plants are not included.
9.3 COEUR D'ALENE LAKE
Two alternatives were developed for Coeur d'Alene Lake. These are:
• Alternative 1—No Action
• Alternative 2—Institutional Controls
As described in Sections 5.2.3 and 7.1.2, Harrison Beach, which is the subject of cleanup as part
of the UPRR action, is the only area evaluated that had risks exceeding target health goals.
Consequently, alternatives were not developed for protection of human health.
As described in the FS (USEPA 2001c), active remediation (e.g., dredging, capping) of lakebed
sediments was not retained for alternative development based on technical implementability and
cost. Although a large volume of contaminated sediments are present in the lake bottom, under
current conditions, more metals enter the lake annually from the Coeur d'Alene River than flow
out of the lake into the Spokane River.
Alternative 1—No Action
The no action alternative is developed to provide a basis for comparing existing and future
environmental impacts that would be present if no remedy is implemented in Coeur d'Alene
Lake. Alternative 1 would include monitoring.
Alternative 2—Institutional Controls
This alternative includes institutional controls such as signage, monitoring, and implementation
of the Lake Management Plan (Coeur d'Alene Tribe, et al. 1996). The latter is summarized in
the following paragraphs.
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A lake management study was initiated in 1991. One of the objectives of this study was to
develop a lake management plan that would identify actions needed to achieve water quality
goals. It was not deemed appropriate to apply a single water management strategy to the entire
lake, therefore, the lake was divided into the following four water quality management zones:
• Nearshore (water depths less than 20 feet)
• Shallow, southern lake (south of the mouth of the Coeur d'Alene River and
including the shallow lakes such as Benewah, Chatcolet, Hidden, and Round)
• Lower rivers (lower reaches of the St. Joe and Coeur d'Alene Rivers that are
affected by backwater from the lake)
• Deep, open water (north of the mouth of the Coeur d'Alene River)
Management goals for the nearshore zone primarily involve implementation of best management
practices to control erosion from watersheds that feed the lake. Residential and municipal sewer
systems will also be addressed to reduce nutrient loadings entering the lake from these sources.
In the shallow, southern lake, best management practices would also be employed to reduce
sediments entering the lake through erosion from littoral areas of the lake, riverbanks, and
watersheds. Where necessary, municipal water treatment plants would be upgraded to reduce
nutrient contributions to the lake. Establishment of "no wake" zones was suggested in the Lake
Management Plan for erosional stream banks.
The principal focus of the Lake Management Plan in the lower Coeur d'Alene River is to reduce
riverbank erosion. This would be accomplished through bank stabilization.
In the deep, open water zone, management practices to improve water and sediment quality
would primarily be those employed in the other three zones. Deep waters in the lake would be a
beneficiary of actions taken to reduce erosion and nutrient loading from within the Basin.
9.4 SPOKANE RIVER
Five alternatives have been developed for the Spokane River upstream of the Spokane Indian
Reservation. These are:
• Alternative 1—No Action
• Alternative 2—Institutional Controls
• Alternative 3—Containment with Limited Removal and Disposal
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• Alternative 4—More Extensive Removal, Disposal, and Treatment
• Alternative 5—Maximum Removal and Disposal
The State of Idaho and the Mining Companies did not develop cleanup plans for the Spokane
River.
Alternatives for the Spokane River address both human health and ecological protection and
were developed based on specific input from the State of Washington. The scope of the
alternatives is limited to sites from the Washington/Idaho border downstream to Upriver Dam.
The Washington State Department of Ecology, EPA, the Spokane Tribe, and the U.S.
Department of Interior are continuing to evaluate the river downstream of Upriver Dam, and the
need for actions in these areas will be considered in the future.
Alternative 1—No Action
Alternative 1 includes no actions to control exposures of humans and ecological receptors to
contaminants. Risks to humans, fish and other aquatic receptors, birds, and terrestrial receptors
would continue to exist for the foreseeable future.
Alternative 2—Institutional Controls
Institutional controls would include the maintenance of the existing health postings and
advisories at beaches and restriction of vehicular access at certain key locations. Although
pedestrian access to the sites would not be restricted, the postings and advisories may encourage
some individuals to reduce their exposure to the contaminated deposits. Restricting vehicular
access would help reduce erosion of the contaminated deposits and allow vegetation to naturally
re-establish.
Alternative 3—Containment with Limited Removal and Disposal
Alternative 3 includes actions focused on addressing potential human health risks. Containment
actions, supplemented by removals where necessary, would be used to reduce or eliminate the
direct contact and ingestion human health exposure pathways. Beach material posing potential
human health risks would generally be left in place and covered with a clean layer of imported
beach material. In locations where habitat may be adversely affected by the grade changes
created by a cover, other actions such as excavation and disposal, or excavation and on-site
consolidation, would be used. In these areas, the excavated areas would be backfilled with
suitable material to restore desired grades and elevations. In-stream sediments would receive no
action under Alternative 3.
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Alternative 4—More Extensive Removal, Disposal, and Containment
Alternative 4 includes actions to address potential human health risks and ecological risks.
Actions for beach and bank deposits would include all areas addressed under Alternative 3, as
well as critical habitat areas that may pose significant ecological risks. The affected beach and
bank materials would be excavated and disposed of off-site, permanently eliminating the human
health and ecological exposure pathways of concern. All excavated areas would be backfilled
with suitable material, to restore desired grades and elevations. In-stream sediments (behind
Upriver Dam) exceeding PRGs would be capped to minimize direct ecological exposures.
Alternative 5—Maximum Removal and Disposal
Alternative 5 includes more extensive beach and in-stream sediment cleanup actions to remove,
where practicable, all materials posing significant human health or ecological risks. The affected
beach and bank materials would be excavated and disposed of off-site, permanently eliminating
the human health and ecological exposure pathways of concern. All excavated areas would be
backfilled with suitable material, to restore desired grades and elevations. In-stream sediments
behind Upriver Dam that exceed PRGs would be dredged and disposed of off-site, eliminating
the ecological exposures of concern.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-14
Table 9.2-1
Summary of Ecological Alternatives Developed for the Upper and Lower Basins
Source/.\iv;i
.\llcrn;ili\c 2
( nnl;iiii/M;il)ili/i- willi
l.imik'd UcmoMil iind
1 IVillllKMll
.\lu-rn;ili\i- 3
More l'.\(oiisi\c Kcmn\;il.
Disnosiil. iind 1 iviilimwil
Allcrn;ili\i- 4
Miixiiniiin Rcino\;il.
Disposiil. iind
1 rciilmcnl
Alloriiiil i\ c 5
Sliilc of 1 thilio
( k'iiniip I'liin
AIU'rn;ili\i' ft
Mining ( oni|);ink's
( loiiniii) Phi it
I |)|KT Biisill
Floodplain Sediment
Removals of tailings-
impacted deposits in the
current 100-year floodplain
(excluding in-stream
deposits) with disposal in
local repositories; bank and
stream stabilization using
bioengineering methods
Same as Alternative 2 plus
removal of accessible
tailings-impacted deposits on
the channel-side of 1-90, with
disposal in regional
repositories;3 selected areas
of hydraulic isolation with
treatment of groundwater in a
regional water treatment
plant;b and passive treatment
of Canyon Creek surface
waterd
Same as Alternative 3
but with maximum
removal of tailings-
impacted deposits
and maximum use of
hydraulic isolation
with treatment of
groundwater at a
regional water
treatment plant0
Selected removals from
the 100-year floodplain,
with capping;
bioengineering and
vegetative stabilization of
selected stream banks and
floodplains; selected use
of riprap.
Limited removals;
bank and stream
stabilization using
bioengineering
methods
Tailings Piles/
Impoundments
Regrading and capping in
place, as practical; otherwise,
removal with disposal in on
site or local repositories.
Hydraulic isolation used for
the Hecla-Star tailings
impoundments in Canyon
Creek
Similar to Alternative 2 but
greater use of removals with
disposal in on-site, local, or
regional repositories; and
greater use of hydraulic
isolation
Maximum excavation
and use of regional
repositories
Removal from the 100-
year floodplain with
disposal in local or
regional repositories; in-
place closure of existing
impoundments
Soil cover in place;
limited removal
(Hecla-Star complex
at Burke) with
disposal in an offsite
repository
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-15
Table 9.2-1 (Continued)
Summary of Ecological Alternatives Developed for the Upper and Lower Basins
Source/.\iv;i
.\llcrn;ili\c 2
( onl;iin/M;il>ili/i- willi
Limited Kcmo\;il :iikI
1 IVillllKMll
.\lu-rn;ili\i- 3
More l'.\(oiisi\c Kcmo\;il.
Disnosiil. iind Tiv;ilim-nl
Allcrn;ili\i- 4
Miixiiniiin Rcino\;il.
Disposal, iind
1 rciilmcnl
Alloriiiil i\ c 5
Slide of Idnlio
( k'iiniip I'liin
AIU'rn;ili\i* ft
Mining Conipiinios
( k'iiniip Phi it
I pper Biisin (Con I i niiod)
Waste Rock Piles
Within the 100-year
floodplain, in-place regrading
and capping, as practical, or
removal; no action otherwise
Similar to Alternative 2 but
with more removal and less
regrading
Removal from the
100-yr floodplain
with disposal in
regional repositories;
regrading and
vegetative cover
otherwise.
Regrading or relocation
out of the 100-year
floodplain, with selected
capping
Removal from the
100-yr floodplain; no
action otherwise
Adits
Major load sources—
Treatment using passive, on-
site technologies
Minor load sources—No
action
Major Load Sources—
Collection and conveyance to
a regional water treatment
plant
Minor Load Sources—
Treatment using passive, on-
site technologies
Major load sources—
Same as Alternative
3, but applied to more
adits
Minor load sources—
Same as Alternative
3, but applied to more
adits
Major load sources (14
total)—Treatment using
passive, on-site
technologies
Minor load sources—No
action
Major load sources—
Infiltration and water
level control
followed by wetland
treatment if necessary
Minor load sources—
No action
Low or ISiisin
1 liver Banks and
Levees
Partial removal of
contaminated "bank wedges"
with disposal in a regional
repository at Cataldo/Mission
Flats
Complete removal of
contaminated "bank
wedges;" disposal in a
regional repository at
Cataldo/Mission Flats or
consolidation using CAD
(confined aquatic disposal) in
one or more of the lateral
lakes
Same as Alternative 3
Partial removal and
stabilization by grading
and bioengineering.
Implementation of a river
management plan to
prevent unacceptable
erosion of the banks.
Revegetation,
bioengineering, and
limited removals
based on
susceptibility of
banks to erosion.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-16
Table 9.2-1 (Continued)
Summary of Ecological Alternatives Developed for the Upper and Lower Basins
Source/.\iv;i
.\llcrn;ili\c 2
( nnl;iiii/M;il)ili/i- willi
l.imik'd Ui'iiio\;il iiiid
1 IVillllKMll
.\lu-rn;ili\i- 3
More l'.\(oiisi\c Kcmn\;il.
Disnosiil. iind Tiv;ilim-nl
Allcrn;ili\i- 4
Miixiiniiin Rcino\;il.
Disposiil. iinri
1 rciilmcnl
Alloriiiil i\ c 5
Sliilc of 1 thilio
( k'iiniip I'liin
AIU'rn;ili\i' ft
Mining ( oni|);ink's
( loiiniii) Phi it
Lowoi- ISiisin (CunliniK'd)
River Bed
No action
Complete removal of affected
sediments; same disposal
options as for river banks and
levees
Same as Alternative 3
Partial removal and
disposal of contaminated
sediments to eliminate hot
spots and create hydraulic
capacity as needed.
No action
Wetlands
Strobl Marsh and Thompson
Marsh—Limited removals,
capping and protective dikes
to control potential re-
contamination from flood
events
Strobl Marsh, Campbell
Marsh, Orling Slough,
Hidden Marsh, Moffit
Slough, Thompson Marsh,
Lane Marsh, and wetland
areas of Thompson,
Killarney, Swan, and
Medicine Lakes—Sediment
removal; same disposal
options as for river removals;
revegetation with native
plants and soil amendments
Maximum sediment
removal; revegetation
with native plants and
soil amendments;
disposal same as for
Alternative 3
Spot removals, capping
and/or chemical
treatments and re-
vegetation in areas with
high lead concentrations
and high use by water
fowl, including within or
surrounding Orling
Slough, Strobl Marsh,
Lane Marsh (including
seven splay areas),
Hidden Marsh, Campbell
Marsh, Thompson Marsh,
Moffit Slough; Medicine
Lake, Swan Lake, and
Thompson Lake.
Habitat shifting
techniques, and
consideration of
selective in situ
chemical stabilization
and/or capping with
biosolid material of
some of the most
lead-enriched
sediments
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-17
Table 9.2-1 (Continued)
Summary of Ecological Alternatives Developed for the Upper and Lower Basins
Source/.\iv;i
.\llcrn;ili\c 2
( nnl;iiii/M;il)ili/i- willi
l.imik'd UcmoMil iiiid
1 IVillllKMll
.\lu-rn;ili\i- 3
More l'.\(oiisi\c Kcmn\;il.
Disnosiil. iind Tiv;ilim-nl
Allcrn;ili\i- 4
Miixiiniiin Rcino\;il.
Disposiil. iinri
1 rciilmcnl
Alloriiiil i\ c 5
Sliilc of 1 thilio
( k'iiniip I'liin
AIU'rn;ili\i' ft
Mining ( oni|);ink's
( loiiniii) Phi it
Lowoi- ISiisin (CunliniK'd)
Lateral Lakes
Thompson Lake—Dredging
from the shore to a water
depth of approximately 6 feet
with disposal in a repository
adjacent to the lake
Thompson, Killarney, Swan,
and Medicine Lakes—
Dredging from the shore to
water depths of about six
feet; same disposal options as
for river removals
Maximum dredging;
disposal same as for
Alternative 3
Included with wetlands
Similar to wetlands
Other Floodplain
Areas
Soil amendments to promote
vegetation for erosion control
and chemical stabilization to
reduce metal availability to
ecological receptors and
transport to surface water
Sediment removal; disposal
in a local repository at
Cataldo/Mission Flats;
revegetation with native
plants and soil amendments
Same as wetlands
Soil treatment and re-
vegetation for highly
contaminated areas
Similar to wetlands
Cataldo/Mission
Flats
Hydraulic isolation (using a
groundwater cutoff wall with
a reactive barrier for passive
in situ treatment of
groundwater); surface water
diversion structures, as
needed; amend soils to
provide a suitable growth
medium combined with
planting of suitable
vegetation. Construction of
an engineered repository for
disposal of river bank, levee,
and wetland removals.
Same as Alternative 2 except
treatment of groundwater at a
regional water treatment
plant
Removal and disposal
in an on-site regional
repository
Groundwater cutoff walls;
spot removals, soil
treatment and re-
vegetation
No action
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-18
Table 9.2-1 (Continued)
Summary of Ecological Alternatives Developed for the Upper and Lower Basins
"Regional repositories in Canyon Creek, Ninemile Creek, and along the South Fork Coeur d'Alene River, in addition to the Lower Basin
b Active water treatment assumes high-density sludge hydroxide precipitation with media filtration, processes that are similar to what is being used for the BHSS
Central Treatment Plant. It is assumed that the regional treatment plant would be located near Pinehurst. Pipelines would be used in Canyon Creek, Ninemile
Creek, and the South Fork Coeur d'Alene River to transport collected adit discharge and groundwater to the regional treatment plant. Collected groundwater
from the Cataldo/Mission Flats dredge disposal area would be pumped to the regional treatment plant.
0 One plant located near Pinehurst as for Alternative 3
dPassive treatment of surface water diverted from lower Canyon Creek. Assumed capacity of 60 cfs, and flows greater than 60 cfs would be bypassed.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-19
Table 9.2-2
Descriptions of Typical Conceptual Designs (TCDs) Used with Alternatives 2, 3, and 4
1(1)
I'll rpose
Application ( i ik'i i;i
Excavation
Removal of materials from areas where they are
subject to erosion or leaching.
Tailings, waste rock mixtures, contaminated floodplain sediments, and waste rock piles
that are potentially erodable or significant sources of metals loading.
Regrade/Consolidate/
Vegetative Cover
Isolate waste from human or ecological contact
Decrease potential for erosion of waste
Doesn't significantly decrease infiltration
Erodable or otherwise unstable waste rock piles without significant leaching potential
under Alts 2 and 3. Waste rock with minimal leaching potential under Alt 4.
Low Permeability Cap
Significantly reduce infiltration
Contaminated sediments, tailings, waste rock and waste rock/tailings mixtures that are
potentially significant sources of metals loading under Alt 2.
Waste rock and waste rock/tailings mixtures that are not potential significant sources of
metals loading under Alts 3 and 4.
Low Permeability Cap
with Erosion Protection
Significantly reduce infiltration + minimize
erosion of waste below the nominal 100-year
flood level at sites where relocation above the
flood level could not be implemented due to
steep ground slopes.
Waste rock or waste rock/tailings mixtures that are not significant sources of metal
loading under Alt 2. Waste rock piles subject to erosion that are remotely located or
relatively small sources of metals loading under Alt 3. Would not be used under Alt 4.
Local Repository Above
Flood Level
Provide a relatively high degree of
protectiveness for wastes that are potentially
significant sources of metals loading.
Used for contaminated sediments, tailings, and tailings/waste rock mixtures under Alt 2.
Used for tailings and tailings/waste rock mixtures under Alt 3. Used for waste rock with
erosion or leaching potential under Alt 4.
Regional Repository
Provide the highest level of protection among
the containment TCDs.
Used for tailings and contaminated sediments under Alt 3. More general use under Alt 4,
including all tailings, all tailings/waste rock mixtures that are potentially significant
sources of metals loading, all floodplain sediments containing levels of metals above
PRGs, and all tailings currently contained in abandoned tailings impoundments. May also
be used for some lower-level wastes where it is the most cost effective TCD.
Tailings Impoundment
Closure
To address the closure of abandoned tailings
impoundments or cells under Alternatives 2 and
3.
All abandoned tailings impoundments and cells under Alts 2 and 3.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-20
Table 9.2-2 (Continued)
Descriptions of Typical Conceptual Designs (TCDs) Used with Alternatives 2, 3, and 4
1(1)
I'll rposi*
Application (rik'riii
Hydraulic Isolation
Using Slurry Wall
To minimize the discharge of contaminated
groundwater to the surface water system,
thereby reducing the dissolved metals loading to
the surface water system.
Areas where metals impacts to groundwater are not controlled by removal and
containment of source materials under Alts 3 and 4.
Hydroxide Precipitation
with Media Filtration
To remove heavy metals from an aqueous
stream using active treatment.
Active treatment used to provide relatively high metals removal rates and treatment
reliability for water containing high metals loads. It would also be used for treating flow
rates in excess of those that could practically be treated using passive treatment.
Active treatment used under Alts. 3 and 4 for adits identified as major loaders, leachate
from regional repositories, and contaminated groundwater.
Permeable Reactive
Barrier
To remove metals through
adsorption/precipitation reactions using apatite
or another chemical reagent within a permeable
reactive barrier or treatment bed. Typically for
oxidizing or low iron conditions.
Generally applicable for lower flow volumes such as drainage from adits, seeps, leachate
from repositories, and runoff from waste piles.
Used under Alt 2 for adits identified as major loaders. Used under Alts 3 and 4 for adits
not identified as major loaders, but discharging metals at levels of concern. Potentially
used for leachate from repositories and contaminated groundwater under Alternatives 3
and 4.
Passive Treatment Pond
To remove metals from surface water using
passive treatment
Used to treat moderate to high surface water flow rates under Alternative 3. Storm flows
would typically not be treated. Used where source-by-source treatment is very costly
and/or difficult to implement.
Current Deflector
Directs stream energy away from erodable
areas, or uses series of deflectors to dissipate
stream energy. Creates scour holes, pools and
other habitat features. May be oriented to serve
as sediment traps.
Apply throughout Upper Basin where stream bank and bedload stabilization, and
dissipation of stream energy is desirable.
Bank Stabilization
Using Bioengineered
Revetments
Protects eroding streambanks or rehabilitates
banks after excavation.
Applicable in low to high energy stream environments in Upper Basin
Vegetative Bank
Stabilization
Stabilizes eroding streambanks or reconstructs
them after excavation and removal of bank
material. Rock toe prevents undermining.
Applicable in low energy stream environments in Upper Basin and Lower Basin. May be
used in higher-energy stream environments in conjunction with current deflectors.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-21
Table 9.2-2 (Continued)
Descriptions of Typical Conceptual Designs (TCDs) Used with Alternatives 2, 3, and 4
1(1)
I'll rposi*
Application (rik'riii
Floodplain/Riparian
Planting
Stabilize exposed floodplains, or floodplains
disturbed by remedial activities.
Applicable in floodplain areas in the Upper Basin and Lower Basin.
Off-Channel Hydrologic
Features
Attenuate stream energy during high flow
periods; improve habitat for aquatic and riparian
species.
Applicable in floodplain areas in Upper Basin where extensive remedial excavation
occurs.
Channel Realignment
Alter stream channel to form a more stable
morphology
Primarily applicable in lower-gradient stream reaches in the Upper Basin.
Soil Amendment
Modify surface soil so that it will support
vegetative growth by using nutrients and other
amendments.
Apply in non-wetland floodplain areas such as existing or historical agricultural and
grazing lands.
Subaqueous Disposal
Contain dredge spoils in an area where they are
isolated from the environment and from
potential receptors including fish and diving
waterfowl.
Applicable to lacustrine sediments and potentially to wetland sediments. Need sufficient
water depth and area for volume of dredge spoils and sufficient material for a clean cap.
Need community acceptance of subaqueous disposal as an option.
Dredge and Barge
Remove contaminated sediment from lacustrine
and palustrine environments and transport the
material to a disposal facility.
Dredging is applicable to sediment with concentrations exceeding an action level in
locations that are accessible to dredging equipment. This TCD could be applied to all
sediment or to a subset such as sediments within a depth window accessed by diving
waterfowl.
Dredge and Pipeline
Same as above
Same as above (dredging). Selection of conveyance equipment would be based on
economic and material availability and suitability to a particular site.
Sediment Trap
Remove contaminated bedload and suspended
load from the river to prevent it from spreading
to downstream locations.
Applicable to areas where the river has historically left its banks. Used to collect
sediment in a controlled manner before it spreads over the floodplain.
Hydraulic Control
Structure
Control flow of water and sediments between
the river and adjacent lakes and wetland areas.
Applicable to existing or proposed connections between the river and adjacent water
bodies where water flow or sediment transport could lead to re-contamination prior to
complete source control in upstream source areas.
Local Repository
(Lower Basin)
Contain dredge spoils in an area where they are
isolated from the environment and from
potential receptors including fish and diving
waterfowl.
Applicable to lacustrine sediments and potentially to wetland sediments. Need sufficient
water depth and area for volume of dredge spoils and sufficient material for a clean cap.
Need community acceptance of subaqueous disposal as an option.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-22
Table 9.2-2 (Continued)
Descriptions of Typical Conceptual Designs (TCDs) Used with Alternatives 2, 3, and 4
1(1)
I'll rposi*
Application (rik'riii
Dike/Levee
Enhancement
To heighten a levee system to protect back-
levee areas from flooding.
Applicable prior to source control to protect back-levee areas. Applicable when the
existing levee, if any, is too low, or where no levee exists.
Wetland Cap
To isolate contaminated materials in place.
Applicable to wetland or floodplain areas where installing a cap provides a sufficient level
of protectiveness and leaching of contaminants to groundwater is not a significant
concern. Applicable in relatively quiescent areas that are protected from recontamination.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-23
Table 9.2-3
Summary of Estimated Unit Costs for Removal, Containment, and Treatment TCDs
Alternatives 2, 3, and 4
Diivil
liidiivi'l
(;i|)il;il
(;i|>il;il
Amiiiiil
Kl)
Disiiinliim
I nil
ClISlS
Cusls
(MM Cusls
;iikI ( iiiiliiiiiiiK-iil TCDs
CI
Excavation
CY
$2.70
$1.60
$0
Cla
Excavation Below Water Table
CY
$26.00
$16.00
$0
Clb
Sediment Excavation
CY
$10.00
$6.00
$0
C2a
Regrade/Consolidate/Revegetate
AC
$56,000
$34,000
$565
C2b
Regrade/Consolidate/Revegetate
AC
$110,000
$66,000
$1,100
C2c
Erosion Protection
AC
$11,000
$6,600
$200
C3
Low Permeability GCL Cap
AC
$151,000
$91,000
$1,500
C4
Low Permeability GCL Cap w/Seepage Coll & Trmt
AC
$170,000
$100,000
$3,100
C5
Low Permeability GCL Cap w/Erosion Protection
AC
$170,000
$100,000
$3,100
C6*
Local Repository w/Erosion Protection
CY
$10.40
$6.20
$0.19
CT
Local Repository Above Flood Level
CY
$9.70
$5.80
$0.18
C8a*
Regional Repository, 1 million cy
CY
$13.10
$7.90
$0.24
C8b*
Regional Repository, 10 million cy
CY
$7.70
$4.60
$0.11
C8c*
Regional Repository, 50 million cy
CY
$6.20
$3.70
$0.07
C9
Tailings Impoundment Closure
AC
$170,000
$100,000
$2,700
CIO
Adit Drainage Collection
LS
$6,200
$3,700
$88
Cll
Hydraulic Isolation Using Slurry Wall
LF
$280
$168
$9
C12
Hydraulic Isolation Using Lined Channel
LF
$500
$300
$16.10
OTHER
HAUL-1
Haul to Repository
CY-MI
$0.89
$0.53
$0
ACC-1
Temporary Access Road
MI
$200,000
$120,000
Assume road will
not be maintained.
.\ili\i- Tiv;ilMK'iil TCDs
CONVEYANCE
PIPE-1
Conveyance Pipeline-6"
LF
$39
$23.00
$0.24
PIPE-2
Conveyance Pipeline-12"
LF
$58
$35
$0.35
PIPE-3
Conveyance Pipeline-24"
LF
$94
$56
$0.57
PIPE-4
HDPE Conveyance Pipeline Cost Factor, $/dia- in.
DIAIN
$5.10
$3.10
$0.03
PRIMARY ACTIVE TREATMENT: HIGH DENSITY SLUDGE HYDROXIDE PRECIPITATION
Variations with Media Filtration
TRMT-la
5,000 gpm
GPM
$2,180
$1,640
$352
TRMT-lb
45,000 gpm
GPM
$1,190
$893
$192
TRMT-2a
w/Sulfide Feed - 5,000 gpm
GPM
$2,270
$1,700
$366
TRMT-2b
w/Sulfide Feed - 45,000 gpm
GPM
$1,230
$923
$198
Variations with Micro filtration
TRMT-3a
5,000 gpm
GPM
$3,550
$2,660
$573
TRMT-3b
45,000 gpm
GPM
$2,580
$1,940
$416
TRMT-4a
w/Sulfide Feed - 5,000 gpm
GPM
$3,650
$2,740
$589
TRMT-4b
w/Sulfide Feed - 45,000 gpm
GPM
$2,620
$1,970
$423
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-24
Table 9.2-3 (Continued)
Summary of Estimated Unit Costs for Removal, Containment, and Treatment TCDs
Alternatives 2, 3, and 4
Diivil
liuliivii
(;i|)il;il
(;i|>il;il
Aniiiiiil
Kl)
Disiiinliim
I nil
ClISlS
(usls
(MM ( usls
I'iissiw ;ind lii-Silu Tiv;iliiK'iil TCDs
PASSIVE I kr \T\1I NT
PT-la
Penneable Reactive Trench w/Apatite
CY
$440
$264
$213
PT-lb
Permeable Reactive Trench w/Organic Mixture
CY
$51
$31
$45
PT-2a
Permeable Reactive Bed w/Apatite
CY
$530
$318
$256
PT-2b
Permeable Reactive Bed w/Organic Mixture
CY
$53
$32
$47
PT-3
Aerobic Wetland
MSF
$2,700
$1,600
$436
PT-4
Anaerobic Wetland
MSF
$7,700
$4,600
$5,800
IN-SITU TREATMENT
PT-5a
Shallow Soil Mixing
CY
$12
$7.20
$0.20
PT-5b
Deep Soil Mixing w/Deep Tiller
CY
$16
$9.60
$0.30
PT-5c
Deep Soil Mixing w/Excavator
CY
$22
$13
$0.40
PT-5d
Deep Soil Mixing w/Auger
CY
$52
$31
$1.10
PT-6a
Underwater Applied with Barge
MSF
$840
$504
$16.90
PT-6b
Underwater Applied with Spreader or Diffuser
MSF
$850
$510
$17
PT-6c
Underwater Applied w/ Spray Equipment from Shore
MSF
$820
$492
$16.50
1 Iiiiii;iii 1 kiilth TCDs
HH1
Access Restrictions (Fence)
LF
$25
$15
$0.20
HH2
Upland Waste Pile Soil Cover
AC
$43,000
$26,000
$433
HH3
Millsite Decontamination
LS
$100,000
$60,000
$403
HH4
Millsite Demolition/Disposal
CY
$120
$72
$1.20
* Does not include haul costs
Notes:
AC - acre
CY - cubic yard
CY-MI - cubic yard - mile
DIA INCH - diameter inch
EA - each
GPM - gallons per minute
LF - linear foot
LS - lump sum
MI - mile
MSF - thousand square feet
TCD - typical conceptual design
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-25
Table 9.2-4
Summary of Estimated Bioengineering TCD Unit Costs, Alternatives 2, 3, and 4
Dirccl
Inriirccl
I nil Price
( iipiliil
(iipiliil
Anniiiil (hV:M
(mlc/TCI)
Description
I nil
Cnsls
Cnsls
Cnsls
( unvnl Dcl'lcclors
CD-I
Current Deflector-Groynes (Spur Dikes, Spurs)
EA
$1,330
$798
$31
CD-2
Current Deflector-Bank Deflector with Root
Wad
EA
$1,160
$696
$28
CD-3
Current Deflector-Riprap Groynes
EA
$1,260
$756
$31
CD-4
Current Deflector-Log Weir & Dam Structure
EA
$1,850
$1,100
$45
CD-5
Current Deflector-Angled Vortex Rock Weir
w/Rootwads
EA
$1,260
$756
$31
CD-6
Current Deflector-Riprap Turning Rock Wall
EA
$1,470
$882
$36
CD-7
Current Deflector-Riprap Tieback
EA
$1,350
$810
$33
CD-Avg
Current Deflector Average Cost
EA
$1,380
$828
$33
\ ciic(iili\c Bunk M;ihili/;iiion
VBS-1
Brush Mattress w/Rock Toe
LF
$37
$22
$0.90
VBS-2
Brush Layer
LF
$19
$11
$0.50
VBS-3
Live Stake, Live Post & Joint Planted Fascines
LF
$53
$32
$1.30
VBS-Avg
Category Average
LF
$36
$22
$0.88
liiink Si;ihili/;ilion I sinji liiucn^inccml Rc\clmcnls
BSBR-1
Vegetated Geogrid
LF
$75
$45
$1.90
BSBR-2
Live Cribwall
LF
$140
$84
$3.40
BSBR-3
Low Energy Tree Revetment
LF
$41
$25
$0.99
BSBR-4
Moderate Energy Tree Revetment
LF
$70
$42
$1.70
BSBR-5
Tree Deflector
LF
$62
$37
$1.50
BSBR-6
Woody Debris & Vegetated Geogrid System
LF
$110
$66
$2.70
BSRB-Avg
Category Average
LF
$80
$50
$1.90
lloo(l|)l;iin/Ri|
iii'iiin Pkinlinii
FP/RP-1
Floodplain/Riparian Planting
SF
$0.39
$0.20
$0.01
FP/RP-2
Floodplain Planting
SF
$1.49
$0.89
$0.02
FP/RP-Avg
Category Average
SF
$0.94
$0.56
$0.01
OIT-Chiinncl ll>ri miotic l-'ciiinrcs
OFFCH-1
Groundwater-Fed Side Channel
SY
$17
$10
$0.20
OFFCH-2
Surface-Fed Side Channel
SY
$29
$17
$0.40
OFFCH-3
Off-Channel Pond
SY
$42
$25
$0.59
OFFCH-Avg
Category Average
SY
$29
$17
$0.40
( hiiiinol Kciili^nmcnl
CHREAL-1
Channel Realignment
SY
$29
$17
$0.40
Notes:
EA - each SY - square yard
LF - linear foot TCD - typical conceptual design
SF - square foot
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-26
Table 9.2-5
Summary of Estimated Unit Costs for Lower Basin TCDs, Alternatives 2, 3, and 4
I nil Price
Tnliil
(iiilc/id)
Description
I nil
I nil ( osl
Anniiiil (kV:M Costs
LB-1
Excavate Coeur d'Alene River banks
(barge-based excavator)
CY
$ 4.92
0
LB-2
Soil amendment
AC
$ 1,636
$23
LB-3a
Subaqueous disposal in lateral lake
CY
$ 5.23
$0.32
LB-3b
Subaqueous disposal in Coeur d'Alene
Lake
CY
$ 6.20
$0.38
LB-4a
Dredge and barge
CY
$ 8.81
0
LB-4b
Dredge and pipeline
CY
$ 7.59
0
LB-5
Sediment trap
EA
$ 270,000
$109,000
LB-6
Hydraulic control structure
EA
$ 57,200
$920
LB-7a
Dike/levee construction
LF
$ 151
$2.40
LB-7b
Dike/levee enhancement
LF
$ 97
$1.60
LB-8
Wetland cap
CY
$ 8.02
$0.13
LB-9
Local repository
CY
$ 6.96
$0.42
Notes:
AC - acre
CY - cubic yard
EA - each
LF - linear foot
TCD - typical conceptual design
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-27
Table 9.2-6
Description of Alternative 5 (State Of Idaho) TCDs and Estimated Unit Costs
Is
lim;ik(l I nil Costs ''
1)1 Q
l)i-si»n
Action
Diivil
C;i|)il;il Costs
liidiivii
Ciisls
Aniiu;il OiKM
Cusls
Assumptions
1
Excavate waste and dispose
locally
$8.50/cy
$5.10
$0
Consists of $3.50/cy for excavation of dry materials and $5/cy for a 1-hr rt haul.
2
Excavate waste or soil and
dispose in region landfill
$18.50/cy
$11
$0
Consists of $3.50/cy for excavation of dry materials and $15/cy for a 3-hr rt haul.
3
Excavate stream sediments or
banks and dispose
$19.50/cy
$12
$0
Consists of $3.50/cy for excavation of wet materials and $15/cy for a 3-hr rt haul plus
$l/cy for access improvements and dewatering or water controls.
4
General grading
$2/cy
$1.20
$0.02
Assumes regrade an average 3' depth over area.
5
Relocate
$6/cy
$3.60
$0.06
Consists of moving waste from drainages onto high ground, soil cover, rip-rap toe
protection and stream stabilization.
6
Toe stabilization
$50 If
$30
$0.91
Assumes rip-rap 10' up slope w/ 3' diameter rock.
7
Cap - general
$16.50/cy
$9.90
$0.17
Includes $15/cy delivered material and $1.50/cy for spreading and grading.
8
Cap - low permeability
$20.50/cy
$12
$0.21
Includes $18.50/cy delivered material and $2.50/cy for spreading, grading and
compacting.
9
Cap - geocover system
$45,000
$27,000
$820
Consists of 6" subgrade @ $2/cy, geosynthetic liner @ $3/sy, 12" drain layer @
$6/cy, surface water control @ $0.25/sy, and soil and vegetation @ $11/cy.
10
Upland vegetation
$5,000/ac
$3,000
$50
Mechanical planting for erosion control.
11
Wetland vegetation
$ll,000/ac
$6,600
$160
Hand/mechanical planting for stabilization, biofiltration and habitat.
12
Streamwork - Riprap
$ 13/lf
$7.80
$0.21
Assumes 3' up the slope or river bank if for erosion control. In-stream rock structures
for habitat improvement.
13
Bioengineering streambanks
$40/lf
$24
$0.97
Includes a combination of plantings, soil wraps, root wads, matting, rip-rap, sills,
barbs and other hydraulic features @ $30/lf plus streambank preparation @ $ 10/lf.
14
Excavate river bed, bank
wedges and floodplain by
barge
$50/cy
$30
$0.81
Consists of excavation from a barge @ $30/cy, dewatering and access improvements
@ $2/cy and a three hours haul @ $18/cy. Wedges assumed as 1 cy/lf.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-28
Table 9.2-6 (Continued)
Description of Alternative 5 (State of Idaho) TCDs and Estimated Unit Costs
Is
lilll;ik-d I nil Cusls ¦'
1)1 Q
l)i-si»n
Ailiun
Diivil
( ;i|)il;il Cusls
liidiivii
Cusls
Aniiu;il OiKM
Cusls
Assumptions
15
Bioengineering streambank
wedge after excavation
$30/lf
$18
$0.73
Includes a combination of plantings, soil wraps, root wads, matting, rip-rap, sills,
barbs and other hydraulic features. Assumes that excavation prepared banks.
16
Bioengineering streambank
w/o excavation
$60/lf
$36
$1.50
Includes grading of banks @ $30/lf plus a combination of plantings, soil wraps, root
wads, matting, rip-rap, sills, barbs and other hydraulic features @ $30/lf. Assumes
difficult access or access by barge.
17
Adit Closure
$62,000
$37,000
$880
Includes gate or barrier and water collection and conveyance system.
18
Adit Water Treatment
$1,000,000
$600,000
$60,000
Unit cost is based upon bid specifications for the Success treatment project and scaled
up to a lcfs adit discharge.
19
Groundwater Cutoff
$150/lf
$90
$4.80
Unit cost is EPA's estimate for LB-3C.
20
Soil Amendment
$20,000/ac
$12,000
$400
Unit cost is based upon EPA's estimate of $ 1,600/cy assuming mixing of the top one
foot.
21
Subaqueous
Capping/Treatment
$37,000/ac
$22,000
$750
Equivalent to EPA's $850/1,000 sf. Capping material may include soil, biosolids, or
chemical amendment
22
Mill Site Demolition
$250,000
$150,000
$2,500
Based upon Bunker Hill industrial complex demolition costs for buildings. Costs for
minor structures such as crib walls are some fraction.
23
Repository Construction
$5.50/cy
$3.30
$0.10
Generally equivalent to EPA's 1,000,000 cy repository but with only a single liner
system and cover. DEQ includes a passive treatment to immobilize metals in leachate
during dewatering. Hauling material to repository is included in DEQ excavation unit
costs. Construction of access road included in DEQ infrastructure allowance.
a The State of Idaho was a source of the estimated direct capital costs.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-29
Table 9.2-7
Alternative 6 (Mining Companies) TCDs and Estimated Unit Costs
1(1)
Description
Diivcl
( iipiliil I nil ( osf'
Indirect Com1'
Aniiiiiil
(Mi.M Cosl
PRP01
General Grading
$10,400/acre
$6,250
$100
PRP02
Slope Regrade
$10.30/cy
$6.20
$0.10
PRP03
Toe Pullback at Stream
$210/lf
$130
$2.10
PRP04
Capping
$67,000/acre
$40,000
$680
PRP05
Revegetation
$2,000/acre
$1,200
$2
PRP06
Material Removal and Disposal at Repository
$18/cy
$10.80
$4.10
PRP07
Stream Cleanout/Disposal at Repository
$89/lf
$53
$20
PRP08
Stream Stabilization
$36/lf
$22
$0.73
PRP09
Adit Source Control
$1,100,000/ea
$660,000
$13,000
PRP10
Adit Discharge Drain Piping
$38/lf
$23
$0.23
PRP11
Block Access
$9,100/ea
$5,500
$130
PRP12
Treatment Wetland Construction
$3,900/gpm
$2,300
$240
PRP13
Riparian enhancement
$5/lf
$3
$0.12
PRP14
Bioengineering BMPs
$42/lf
$25
$1.00
PRP15
Tailings removal
$58/lf
$35
$1.40
PRP16
Streambank actions
$53/lf
$32
$1.30
a The mining companies were the source of estimated direct capital costs.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-30
Table 9.2-8
Summary of Basin Source Quantities Addressed by Alternative
Aivsi/Soiiiti' T\ |H'
I nils
loliil
Qu;ui(i(\
(Jiiiinlil> of Source M;ileri;il Addressed. In I pper ISiisin ;iihI Lower Biisin
l.colotiicnl Al(crn;i(i\c
2
3
4
5
(.
I |)|HT ISiisin
Floodplain Sediments3
cy
7,100,000
2,000,000
5,700,000
7,100,000
195,000
170,000
Tailingsb
cy
11,000,000
3,800,000
8,600,000
9,300,000
2,800,000
3,500,000
Waste Rock0
cy
11,700,000
5,600,000
7,000,000
9,800,000
2,500,000
5,300,000
Adit Drainaged
#Zn/d
101
89
101
101
94
65
Lower liiisin
River bed Sediments6
cy
20,600,000
0
20,600,000
20,600,000
350,000
0
Bank Wedgese
cy
1,780,000
610,000
1,780,000
1,780,000
180,000
27,000
Wetland Sediments6
cy
5,900,000
480,000
2,000,000
5,900,000
240,000
0
Lateral Lake Sediments6
cy
5,900,000
67,000
570,000
5,900,000
94,000
0
Floodplain Sediments6
cy
10,200,000
430,000
2,300,000
10,200,000
2,300,000
0
Cataldo/Mission Flats Dredge Spoils
cy
13,600,000
10,900,000
10,900,000
10,900,000
10,900,000
25,000
(„)iiiinlil> of Source M;ilerhil Addressed. In Spuk;ine Ri\cr AI(crn;i(i\c
Spokiino Ri\er'
2
3
4
5
No! used
Beach/Bank Deposits and In-Stream Sediments
cy
260,000
0
20,000
110,000
260,000
aSediment total volume does not include either less-impacted, generally deeper and more dispersed sediments that are potential source of zinc loading or impacted materials within
fills or embankments (e.g., 1-90 and UPRR rights-of-way); these additional sediment volumes may be as high as approximately 20,000,000 cy.
bTailings volumes include unimpounded tailings and impounded tailings in both inactive and active facilities.
cWaste rock volumes include waste rock in floodplains and uplands, as well as waste rock at active facilities.
dData used to calculate average zinc loading are available for only 53 of 114 discharging adits in the upper basin. Although data are available for the largest loaders, the
cumulative average zinc load from all discharging adits may exceed the amount shown in this table.
eVolumes estimates for all impacted media in the lower basin, CSM Unit 3, are based on lead concentrations exceeding 1,000 mg/kg. Additional volumes of impacted sediments
that are potential sources of zinc loading are not included in these estimates.
fThe study area for the Spokane River ecological alternatives is limited to selected sites identified by the Washington State Department of Ecology between the Washington-Idaho
state line and Upriver Dam.
Notes:
This is a condensed summary with approximate quantities—for a detailed accounting of sources and remedial actions see the FS Part 3, Sections 5 and 6 and appendices as
referenced therein. Quantities of source materials within the BHSS are not included in this table.
Quantities of source material potentially addressed by institutional controls (e.g., access restrictions) or bioengineering actions (e.g., floodplain/riparian zone revegetation or bank
stabilization) are not included.
Alternative 1 is no action. Alternatives 2 through 6 are integrated alternatives for the Upper Basin and Lower Basin. Alternatives 2 through 5 were developed separately for the
Spokane River.
cy - cubic yards #Zn/d - pounds per day of zinc
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-31
Table 9.2-9
Lower Basin Contaminated Habitat Area Remediated by Alternative
WiMliiml I nil
('onliimiiiiik'ri Aivsi. Acres'
Tnl.il lliihiliil AiVii RcnudLikd In
Allcrn;ili\c. Acivs
WiMliiml
l.iike
Ki|)
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 9.0
Page 9-32
Table 9.2-10
Estimated Effectiveness of the Ecological Alternatives for the Upper Basin and Lower
Basin for Reducing Dissolved Metals Loads in the Coeur d'Alene River
l.sliiiiiik'd IViron( Zinc l.ond Reduction ;il Completion olRcmcdv lniplcnicn(;i(ion
Allcrn;ili\c
I'iiichui'sl
lliii'i'ison
4
73
64
3
62
57
2
30
26
5
13
12
6
8
9
1
0
0
Note: estimates of dissolved zinc load reductions do not include consideration of loads from the Bunker Hill Box.
Reference: USEPA (2001f). Probabilistic Analysis of Post-Remediation Metal Loading.
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RECORD OF DECISION Part 2, Decision Summary
Bunker Hill Mining and Metallurgical Complex OU 3 Section 10.0
September 2002 Page 10-1
10.0 COMPARATIVE ANALYSIS OF ALTERNATIVES
This section describes the evaluation of the comprehensive alternatives for protection of human
health and the environment using the CERCLA criteria. EPA uses nine criteria to evaluate the
remedial alternatives individually and against each other in order to select a remedy. These
criteria are shown in Table 10.0-1. The purpose of the comparative analysis is to evaluate the
relative performance of the alternative with respect to the nine evaluation criteria so that the
advantages and disadvantages of each are clearly understood. The Selected Remedy is described
in Section 12.
The results of the comparative analysis are organized in four sections. These are:
Section 10.1
Section 10.2
Section 10.3
Section 10.4
Human Health in Community and Residential Areas
Environmental Protection in the Upper Basin and Lower Basin
Coeur d'Alene Lake
Spokane River
The results are also summarized in a series of tables. In these tables, each of the alternatives is
given a rating (lowest, low, medium, or highest) for each evaluation criterion. The tables also
provide the basis for each rating.
the evaluation of the balancing criteria (state and tribe acceptance and community acceptance)
for the Preferred Alternative in the Proposed Plan is presented in section 12.7.
10.1 HUMAN HEALTH ALTERNATIVES
Based on the comparative analysis, EPA believes the best balance of tradeoffs is represented by
Alternative S4 for soil, Alternative D3 for house dust, Alternative W6 for drinking water, and
Alternative F3 for aquatic food sources.
For soil, Alternatives S4 and S5 are the only alternatives believed likely to meet the human
health RAOs. Consequently, Alternatives SI, S2, and S3 are not considered adequately
protective. The increased implementability, fewer short-term impacts to the community, and
lower cost of the partial removals under Alternative S4 outweigh the somewhat greater reduction
of residual risk resulting from complete removals under Alternative S5. A summary of the
13
comparison of alternatives for soil is presented in Table 10.1-1.
13 Costs for soil alternative S4 differ from those presented for the Selected Remedy because the analysis of
Alternative S4 in the FS included 10 recreational areas and the Selected Remedy included 31 recreational areas.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-2
For house dust, both Alternatives D2 and D3 are expected to achieve the human health RAOs at
most homes where residents participate in the programs. Alternative D1 is not considered
protective for risks from house dust. Alternative D3 provides for additional cleaning at some
homes where exterior soil remediation, dust mats, and vacuum loan programs do not provide
sufficient reductions in exposure to contaminated house dust. The greater reduction in residual
risk and greater long-term reliability of extensive cleaning under Alternative D3 outweigh the
lower cost of the vacuum loan and dust mat programs under Alternative D2. A summary of the
comparison of alternatives for house dust is presented in Table 10.1-2.
For drinking water, Alternatives W3, W4, W5, and W6 are all potentially protective and ARAR-
compliant. Alternatives W1 and W2 are not expected to be protective or ARAR-compliant
where MCLs are exceeded. Alternative W6 provides the best balance of tradeoffs because the
most appropriate technology at each site would be used. Protectiveness and compliance with
ARARs could be achieved at all sites, including those where no suitable alternative aquifer exists
and connection to a public water source would not be feasible. Where a suitable alternative
aquifer does exist or connection to a public water source is feasible, these actions would be taken
and would be expected to have greater long-term reliability than point-of-use treatment
(Alternative W3). A summary of the comparison of alternatives for drinking water is presented
in Table 10.1-3.
For aquatic food sources, Alternative F3 is expected to more effectively limit exposures to
metals than Alternatives F1 or F2. The use of monitoring is expected to more reliably identify
areas of potential exposures and be more likely to result in reduced consumption of aquatic food
sources in areas of exposure. A summary of the comparison of alternatives for aquatic food
sources is presented in Table 10.1-4.
10.2 ECOLOGICAL PROTECTION IN THE UPPER BASIN AND LOWER BASIN
Some of the key issues for evaluating the ecological alternatives identified through the
comparative analysis using the nine CERCLA criteria are discussed below.
Impacted Sediments
Over 100 million tons of impacted sediments are distributed over thousands of acres in the Upper
Basin and Lower Basin. As described in Section 7, the impacted sediments are a major source of
metals exposures for ecological receptors, as well as humans engaged in recreation and
subsistence practices. Impacted sediments are believed to be the major source of metals loading
in the Basin. In the Upper Basin, tailings-impacted floodplain sediments and associated
groundwater are the major sources of dissolved metals to the rivers and streams. In the Lower
Basin, erosion of river bank and bed sediments is the major source of particulate lead. This
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-3
particulate lead is a continuing source of contamination for the Coeur d'Alene River, Coeur
d'Alene Lake, and the Spokane River. Lead transported in the river system has impacted
recreational areas in the Lower Basin and the Spokane River, resulting in posted health advisory
signs at beaches and swimming areas. During flood events, lead transported by the river also
impacts the wetlands and floodplains. The potential exists for future particulate lead transport
and recontamination of recreation and feeding areas cleaned up as part of the Selected Remedy.
Therefore, addressing impacted sediments is a key issue for protection of human health and the
environment.
Large-scale cleanup of impacted sediments, however, would be difficult and costly, presenting
major technical and administrative challenges, as well as significant adverse short-term impacts.
Likely impacts to the local communities and natural environment include increased truck traffic,
dust and noise generation, potential disruption of services and recreation opportunities, and
reduced aesthetic quality. Much of the sediment in the Upper Basin is not considered accessible
due to its location beneath 1-90 and other infrastructure. Private property ownership issues must
also be addressed as a component of cleanup.
The alternatives vary in the degree to which they address the contaminated sediments, with
Alternatives 3 and 4 addressing the sediments to a greater degree than Alternatives 1, 2, 5, and 6.
As summarized in Table 9.2-9, Alternatives 1 through 6 include cleanup of 0 acres, 1,123 acres,
5,358 acres, 12,469 acres, 4,682 acres, and 0 acres, respectively, of contaminated sediments in
wetland, lake, and riparian feeding areas in the Lower Basin. As summarized in Table 9.2-8,
Alternatives 1 through 6 include dredging of 0 cy, 0 cy, 20,600,000 cy, 20,600,000 cy, 350,000
cy, and 0 cy, respectively, of river bed sediments, which are a potential source of particulate lead
in surface water. Alternatives 1 through 6 include removal of 0 cy, 610,0000 cy, 1,780,000 cy,
1,780,000 cy, 180,000 cy, and 27,000 cy, respectively, of contaminated sediments in Lower
Basin riverbanks, which also are a potential source of particulate lead in surface water. The
greater use of removals under Alternatives 3 and 4 would improve the long-term effectiveness
and permanence of these alternatives compared to alternatives that rely more heavily on in-place
bank stabilization measures. In addition, Alternatives 3 and 4 include bioengineering measures
to stabilize remediated banks, which would promote the return of a fully-functioning ecosystem
to a greater degree than alternatives that include armoring to stabilize the banks. Bank armoring,
while potentially effective for stabilizing the banks, uses materials such as riprap and therefore
does not employ materials, such as plants and woody debris, that would promote the return of a
fully-functioning ecosystem.
Time to Achieve Overall Cleanup Goals
The time needed to achieve overall cleanup goals, including AWQC and risk-based sediment
cleanup goals, will be lengthy and require a period of natural recovery for all the alternatives.
The probable time period decreases dramatically with the aggressiveness and completeness of
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-4
the alternative. As noted in Table 9.2-10, the estimated percent zinc load reductions at the
completion of remedy implementation at Pinehurst are approximately 0, 30, 62, 73, 13, and 8 for
Alternatives 1 through 6, respectively. The estimated percent reductions at Harrison are
approximately 0, 26, 57, 64, 12, and 9 for Alternatives 1 through 6, respectively. These
pronounced differences result in considerable differences in the estimated length of time
necessary to achieve AWQC, and hence, protectiveness of aquatic life. As noted in Table 10.2-1
and graphed in Figure 10.2-1, the expected lengths of time to achieve AWQC, on average, at
Pinehurst is estimated to be approximately 225, 161, 46, 198, and 205 percent longer for
Alternatives 1, 2, 3, 5, and 6, respectively, compared to Alternative 4. At Harrison, the expected
lengths of time to achieve AWQC, on average, are approximately 278, 195, 45, 239, and 253
percent longer for Alternatives 1, 2, 3, 5, and 6, respectively, compared to Alternative 4. These
longer periods are particularly noteworthy when considering that the estimated lengths of time to
achieve AWQC, even under the aggressive Alternative 4, are lengthy. While it is not presently
possible to estimate the time to achieve AWQC due to uncertainty with respect to the
effectiveness of remedial actions to be implemented in the Box, modeling of Alternative 4
suggests the expected time to achieve AWQC, on average, will be on the order of approximately
280 and 210 years at Pinehurst and Harrison, respectively, as graphed in Figure 10.2-2.
Benefits to aquatic life begin long before the point in time when AWQC are finally met. As
remedies are implemented, resulting in reduced metals concentrations, aquatic conditions begin
to improve and benefits accrue as concentrations drop further over time. Such benefits will
occur much sooner with the more aggressive alternatives (i.e., Alternatives 3 and 4). As graphed
in Figures 10.2-3 and 10.2-4, water quality conditions at completion of remediation (Time 0 on
the graphs), as represented by multiples of AWQC, will be considerably better under
Alternatives 3 and 4 than the other alternatives. Although the resulting conditions will not be
fully supportive of aquatic life, the reduced dissolved metals concentrations will allow a
substantial improvement to the fisheries and ecosystem, as described in more detail in
Section 12.2.1 Dissolved Metals in Rivers and Streams and the Interim Fishery Benchmarks
Technical Memorandum (URS 2001d). The population and species diversity of fish and aquatic
organisms will continue to improve as cleanup progresses in the Basin.
Availability of Materials
The availability of materials for covering, backfilling, and revegetating waste piles, removal
areas, and repositories is limited. These materials include topsoil (either natural or
manufactured) and uncontaminated fill. Mining of native topsoil could create adverse
environmental impacts at borrow locations. Larger quantities of these materials would be
required to implement alternatives that include more comprehensive levels of cleanup, such as
Alternatives 3 and 4.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-5
Repository Siting
There are limitations on the availability of suitable sites for large engineered repositories for
disposal of excavated or dredged contaminated media. A larger number and capacity of
repositories would be required to implement alternatives that include more comprehensive levels
of cleanup, such as Alternatives 3 and 4.
Long-Term Management and Associated Costs
An effective remedy would likely require substantial long-term management with associated
costs. Institutional programs to protect human health and the environment would be needed.
Depending on the remedy, long-term management may include operation and maintenance of
engineered controls, such as repositories, and water treatment systems. Required periodic
cleanups of remediated areas that are recontaminated by subsequent flood events would add to
long-term management costs, as would the long-term monitoring and periodic site reviews
required under Superfund.
Balance of Tradeoffs
Based on the comparative analysis, EPA believes Alternative 3 represents the best balance of
tradeoffs for a long-term cleanup approach, as summarized in Table 10.2-1. Alternatives 3 and 4
provide substantially greater protection of the environment and shorter times to achieve
compliance with ARARs than Alternatives 1, 2, 5, and 6. Alternatives 3 and 4 would result in
more than twice the reduction of metals loads in surface water relative to the other alternatives,
as shown in Table 9.2-10. Alternatives 3 and 4 also would provide more safe feeding area for
waterfowl and other receptors than Alternatives 1, 2, 5, and 6, as summarized in Table 9.2-9.
Finally, as a result of the greater extent of bed and bank removals included under Alternatives 3
and 4, these alternatives would provide for more comprehensive and permanent reductions in
particulate lead transported in the river system than Alternatives 1, 2, 5, and 6.
Although Alternative 4 would provide greater long-term effectiveness than Alternative 3, this
consideration is outweighed by the greater implementability, fewer short-term impacts to the
communities and the environment, and the lower cost of Alternative 3 compared to Alternative 4.
Alternative 3 relies more on groundwater and surface water treatment to reduce dissolved metals
loads from the Upper Basin and Mission Flats than Alternative 4, which relies more heavily on
removals. In addition, Alternative 4 includes actions in areas (for example, waste rock piles that
are not located near streams) that pose relatively little risk. Because it relies on extensive
removals, Alternative 4 would likely be more difficult to implement than Alternative 3. As a
result, Alternative 3 would be more cost effective, have fewer community and environmental
impacts from excavation and trucking, and require less repository space and topsoil or growth
media than Alternative 4. Since Alternative 3 includes more treatment than Alternative 4, it
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-6
satisfies CERCLA's preference for reduction of toxicity, mobility, or volume through treatment
to a greater extent than Alternative 4.
10.3 COEUR D'ALENE LAKE
Based on the comparative analysis, the best balance of tradeoffs is represented by Alternative 2.
Alternative 2 contains measures to reduce the likelihood of an increased rate of metals release
from the 44 to 50 million cubic yards of contaminated sediments in the lake. Alternative 1
contains no measures to control metals release from sediments. The increased long-term
effectiveness of Alternative 2 outweighs its marginal increase in cost and marginal reduction in
implementability relative to Alternative 1. Table 10.3-1 summarizes the comparative analysis of
the alternatives for Coeur d'Alene Lake. The details of the evaluation can be found in Part 3
Section 8 of the FS.
Alternative 2 provides for implementation of the Lake Management Plan. The Plan was
developed by local regulatory stakeholders. It has not been fully implemented to date. However,
those entities have expressed an interest in implementing the Plan under their independent
authorities.
10.4 SPOKANE RIVER
Based on the comparative analysis, the best balance of tradeoffs is represented by a combination
of Alternatives 3, 4, and 5. The best balance of tradeoffs at each individual site would depend on
site-specific characteristics including the potential risks to human and ecological receptors,
potential for recontamination and other long-term maintenance requirements, and cost.
Alternatives 3, 4, and 5 are all potentially protective and ARAR-compliant. Alternatives 1 and 2
are not expected to be protective or comply with sediment ARARs. Table 10.4-1 summarizes
the comparative analysis of the alternatives for the Spokane River. The details of the evaluation
can be found in Section 7 of Part 3 of the FS.
10.5 CONCLUSIONS FROM COMPARATIVE ANALYSIS
Based on the comparative analysis, EPA determined that Alternatives S4, D3, W6, and F3 for
protection of human health and Ecological Alternative 3 for protection of the environment
represent the best balance of tradeoffs in the Upper Basin and Lower Basin and that a
combination of Alternatives 3, 4, and 5 represents the best balance of tradeoffs for the Spokane
River.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-7
Implementation of the human health remedy in the community and residential areas can be
achieved within a reasonable timeframe. However, given the amount of work to be performed
under Ecological Alternative 3, the vast area involved, and the broad variety of media and source
types to be addressed, EPA, in consultation with stakeholders, has determined that an adaptive
management strategy is a more reasoned approach to implement the environmental cleanup of
the Basin. This approach starts with existing information and progressively incorporates lessons
learned from experience as remedial actions are implemented, monitored, and refined. During
implementation, EPA will learn which remedial actions are most effective. This process can
help assure that as progress toward the long-term cleanup goals for the Basin is made, actions
could be prioritized within available funds and be cost-effective. EPA recognizes that combined
improvements from cleanup activities and natural recovery will be required to achieve ARARs.
The Selected Remedy, which is described in Section 12.0, is an interim measure and represents a
significant remedial response toward meeting the goal of full protection of human health and the
environment in the Basin. The Selected Remedy includes the full remedy needed to protect
humans from exposures that currently occur in the community and residential areas, including
identified recreational areas, of the Upper Basin and Lower Basin, as well as at Spokane River
recreational sites upstream of Upriver Dam. For environmental protection, the Selected Remedy
identifies approximately 30 years of prioritized actions in areas of the Basin upstream of Coeur
d'Alene Lake. It also includes cleanup of Spokane River sites between the Washington/Idaho
border and Upriver Dam.
Specifically, EPA has selected a remedy that will:
• Provide a cost-effective remedial action
• Allow cleanup activities for human health and environmental protection to
proceed concurrently
• Prioritize remediation of upstream sources while beginning actions in selected
downstream areas
• Provide measurable, tangible benefits to humans and environmental receptors
(e.g. fish, birds) within a relatively short time in the areas addressed
• Balance priorities identified by stakeholders (states, tribes, federal trustees, and
the public)
• Build upon past remedial work performed by others
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-8
• Expend a level of effort annually that would allow the cleanup to efficiently move
forward while applying the experience gained
• Moderate short-term environmental and socioeconomic impacts
• Take advantage of innovative, more cost-effective technologies as they emerge
The Selected Remedy meets the criteria established in the NCP and EPA guidance. EPA's
threshold criteria in selecting a final remedy include overall protection of human health and the
environment and compliance with ARARs. The Selected Remedy includes the complete remedy
for human health in the communities and residential areas, including identified recreational
areas, of the Upper Basin and Lower Basin and along the Spokane River upstream of Upriver
Dam. It would be protective of human health and comply with human health ARARs in these
areas. Although the Selected Remedy is not anticipated to be fully protective of the environment
and achieve environmental ARARs, it represents what EPA believes is a significant step toward
these goals. The Selected Remedy would comply with those ARARs that are included within the
scope of the proposed work. Compliance with ARARs would be achieved as work is planned
and performed.
The Selected Remedy should neither be inconsistent with nor preclude implementation of the
final remedy (see 40 CFR 300.430(a)(l)(ii)(B)). The Selected Remedy for environmental
protection includes prioritized Upper Basin and Lower Basin actions derived from FS Ecological
Alternative 3, which is the level of cleanup EPA believes, based on existing information, is
necessary to achieve long-term cleanup goals, as well as the full remedy for the Spokane River
between the state line and Upriver Dam.
The Selected Remedy has therefore been determined by EPA to represent the best balance of
tradeoffs using the CERCLA balancing criteria. The Selected Remedy would achieve long-term
effectiveness by reducing residual risks resulting from exposure to lead in soil, house dust,
drinking water, and aquatic food sources to acceptable levels. An institutional controls program
and follow-up health services would be used to maintain remedy effectiveness over time. The
Selected Remedy would go a long way towards achieving long-term effectiveness and
permanence by beginning to control the sources and reduce ecological exposure in high-use
areas. It would achieve substantial reductions in residual risks to aquatic receptors resulting
from metals in surface water and to waterfowl and other animals resulting from metals in
wetland and lateral lake sediments. The Selected Remedy includes treatment of surface water in
the Canyon and Ninemile Creek areas, which is consistent with EPA's preference to reduce
toxicity, mobility, or volume through treatment.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-9
The Selected Remedy would provide short-term effectiveness through prioritizing human health
actions and focusing environmental emphasis on dissolved metals in rivers and streams, lead in
floodplain soil and sediment, and particulate lead in surface water, while limiting adverse
impacts on the communities and ecosystems. As construction is completed at individual sites,
RAOs for those soils, sediments, and source materials addressed by the Selected Remedy would
be achieved. Implementation of the human health remedies is a top priority, and it is anticipated
the human health RAOs would be achieved within a relatively short time. The Selected Remedy
includes sequenced cleanup actions that would be both technically and administratively
implementable. Requirements for repository space and relatively scarce materials such as topsoil
or growth media would be spread out over time to enhance implementability. The Selected
Remedy achieves a significant reduction in residual risk relative to its cost. It would be cost
effective as its costs are proportional to its overall effectiveness.
-------
South Fork at Pinehurst
Coeur d'Alene River at Harrison
a>
>
re
c
a>
a>
O)
re
-4-i
C
a>
a
a>
a.
aT
E
400%
300%
200%
100%
378%
261%
146% 145%
100%
Alt4
Alt3
Alt2
Alt5
Alt6
Alt1
Alternative
»E PA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 10.2-1
Estimated Relative Time to Reach AWQC Without Bunker Hill Box Loading
-------
South Fork at Pinehurst
Coeur d'Alene River at Harrison
1000
750
re
0)
>-
a)
E
- 500
250 —
Alt4
Alt3
Alt2 Alt5
Alternative
Alt6
Alt1
»E PA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 10.2-2
Estimated Time to Reach AWQC Without Bunker Hill Box Loading
-------
South Fork at Pinehurst
Coeur d'Alene River at Harrison
1000
750
re
0)
>-
a)
E
- 500
250 —
Alt4
Alt3
Alt2 Alt5
Alternative
Alt6
Alt1
»E PA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 10.2-2
Estimated Time to Reach AWQC Without Bunker Hill Box Loading
-------
• Alternative 1:
-H—Alternative 5:
-Alternative 2:
-Alternative 6:
-Alternative 3:
¦ Fishery Tiers
—Alternative 4:
250
500
750
1,000
10
o
a
O 5
o
" XV X
A
Fishery Tier 2
r
\ X.
i
k
Fishery Tier 3 -
r
- ¦ ¦ -A -TTTTra
I
^
k
Fishery Tier 4 -
I Fishery Tier 5
i i i i
i i i i
i i i i I i i i i T
250 500 750
Time t (Years After Remediation)
1,000
Note:
If historic loadings from the Box were
included without any future reduction,
AWQC multiple would increase by a
factor of approximately:
~
Alt 1 ~
2.1
~
Alt 2D
2.6
~
Alt 3D
4.0
~
Alt AD
5.2
~
Alt 5D
2.3
~
Alt 6D
2.2
Fishery Tier Definitions
Tier 0: CNo migrating or resident fish observed
~ (concentrations generally >20X chronic AWQC)
Tier 1:DPresence of migrating fish only, no fish observed during resident fish surveys
~ (concentrations below <20X acute AWQC)
Tier 2: ~ Presence of resident salmonids (trout) of any species, sculpin absent
~ (concentrations from 7X to 10X chronic AWQC)
Tier 3: ~ Presence of 3 or more classes of resident salmonids, including young of the year (YOY)
~ sculpin absent (concentrations from 3X to 7X chronic AWQC)
Tier 4: ~ Presence of 3 or more classes of resident salmonids, including YOY and sculpin
~ (concentrations from 1X to 3X chronic AWQC)
Tier 5: ~ Presence of 5 salmonid age classes, including YOY, sculpin, and bull trout. Fauna dominated
~ by native species at high densities (0.1 to >0.3 fish/m2)
~ (least impacted watersheds with concentrations <1X chronic AWQC)
~
SEM
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 10.2-3
Comparison of Expected Values of Zinc AWQC Ratio at Pinehurst Without Bunker Hill Box Loading
-------
¦Alternative 1:
-Alternative 5:
250
¦Alternative 2:
-Alternative 6:
¦Alternative 3:
¦ Fishery Tiers
¦Alternative 4:
1,000
Fishery Tier 3
Fishery Tier 4
Fishery Tier 5
250 500
Time, Years After Remediation
750
1,000
Note:
If historic loadings from the Box were
included without any future reduction,
AWQC multiple would increase by a
factor of approximately:
~
Alt 1 ~
1.7
~
Alt 2D
2.0
~
Alt 3D
2.6
~
Alt AD
3.0
~
Alt 5D
1.8
~
Alt 6D
1.8
Fishery Tier Definitions
Tier 0: CNo migrating or resident fish observed
~ (concentrations generally >20X chronic AWQC)
Tier 1 :~ Presence of migrating fish only, no fish observed during resident fish surveys
~ (concentrations below <20X acute AWQC)
Tier 2: ~ Presence of resident salmonids (trout) of any species, sculpin absent
~ (concentrations from 7X to 10X chronic AWQC)
Tier 3: ~ Presence of 3 or more classes of resident salmonids, including young of the year (YOY)
~ sculpin absent (concentrations from 3X to 7X chronic AWQC)
Tier 4:~ Presence of 3 or more classes of resident salmonids, including YOY and sculpin
~ (concentrations from 1X to 3X chronic AWQC)
Tier 5:~ Presence of 5 salmonid age classes, including YOY, sculpin, and bull trout. Fauna dominated
~ by native species at high densities (0.1 to >0.3 fish/m2)
~ (least impacted watersheds with concentrations <1X chronic AWQC)
~
SEM
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 10.2-4
Comparison of Expected Values of Zinc AWQC Ratio at Harrison Without Bunker Hill Box Loading
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-14
Table 10.0-1
Evaluation Criteria for Superfund Remedial Alternatives
('riU'riun
DcMTiplinn
Threshold
criteria
Overall protection of
human health and the
environment
Determines whether an alternative eliminates, reduces, or controls threats to
public health and the environment through institutional controls,
engineering controls, or treatment.
Compliance with ARARs
Evaluates whether the alternative meets federal, state, and tribal
environmental statutes, regulations, and other requirements that pertain to
the site, or whether a waiver is justified.
Balancing criteria
Long-term effectiveness
and permanence
Considers the ability of an alternative to maintain protection of human
health and the environment over time.
Reduction of toxicity,
mobility, or volume
through treatment
Evaluates an alternative's use of treatment to reduce a) the harmful effects
of principal contaminants, b) their ability to move in the environment, and
c) the amount of contamination remaining after remedy implementation.
Short-term effectiveness
Considers the length of time needed to implement an alternative and the
risk the alternative poses to workers, residents, and the environment during
implementation.
Implementability
Considers the technical and administrative feasibility of implementing the
alternative, including factors such as the availability of materials and
services.
Cost
Includes estimated present worth capital and operations and maintenance
(O&M) costs. O&M costs are estimated for a 30-year period using a
discount rate of 7%.
Modifying
criteria
State/tribal acceptance
Considers whether the States and Tribes agree with the EPA's analyses and
recommendations, as described in the RI/FS and the Proposed Plan.
Community acceptance
Considers whether the local community agrees with the EPA's analyses and
the Selected Remedy. Comments received on the Proposed Plan during the
public comment period are an important indicator of community
acceptance.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-15
Table 10.1-1
Comparison of Soil Alternatives for Protection of Human Health in Residential and Community Areas
Criterion
AlHTiiali\c SI
No Action
Allcrnali\c S2
Inloi'iiialion and Inlcncnlion
Allcrnali\c S3
Access Modifications
Allcrnali\c S4
Parlial Kcmo\al
Allcrnali\c S5
Complete Kcmo\al
Overall Protection of
Human Health and the
Environment
Lowest
Would not be protective. Unlikely to
achieve health risk goals.
Low
Limited reduction in exposure from behavior
modification, would not achieve full
protection. Not preventative- intervention
would occur only after child exhibits
elevated blood lead. Unlikely to achieve
health risk goals.
Low
Access would be limited at recreation areas,
but exposures at the home would be the same
as Alternative S2. Unlikely to achieve health
risk goals.
Highest
Removal and replacement of top layer of
contaminated soil with clean cap would
result in a large increase in protectiveness
relative to Alternative S3. Addresses
exposures at recreational areas. Expected to
achieve health risk goals.
Highest
Most protective for yards and community areas
where all contaminated soil would be
removed; however, does not address exposures
at recreational areas. Expected to achieve
health risk goals, with possible exception of
frequent recreational users.
Compliance with ARARs
Not applicable
No ARARs apply to Alternative SI.
Not applicable
No ARARs apply to Alternative S2.
Not applicable
No ARARs apply to Alternative S3.
Highest
Could be implemented in compliance with
action and location-specific ARARs.
Highest
Could be implemented in compliance with
action and location-specific ARARs.
Long-Term Effectiveness
and Permanence
Not evaluated
Alternative does not meet the threshold
criteria.
Low
Residual risks would be associated with
contaminated soil left in place. Long-term
reliability of institutional controls would rely
on voluntary compliance and participation.
Low
Residual risks would be associated with
contaminated soil left in place. Long-term
reliability of institutional controls would rely
on voluntary compliance and participation.
Medium
Large reduction in residual risk and
reliability of controls relative to Alternative
S3 because contaminated soil would be
removed. Some residual risk from potential
exposure to deeper contaminated soils not
removed.
Medium
Complete soil removal would result in least
residual risk and greatest reliability for yards
and community areas. Residual risks would
remain in recreational areas.
Reduction of Toxicity,
Mobility, or Volume
through Treatment
None of the alternatives include treatment
Short-Term Effectiveness
Short-term impacts to
community and
environment
- Time to achieve RAOs
Low
Few impacts to community and environment;
however, would not achieve human health
RAOs because yard soil is not addressed.
Low
Relatively few impacts to community and the
environment; however, would not achieve
human health RAOs because yard soils are
not addressed.
Highest
Would achieve human health RAOs after the
completion of remedial actions in all areas.
Some impacts to community from traffic and
dust generation.
Medium
Would achieve human health RAOs after the
completion of remedial actions in all areas
except recreational areas. Most impacts to
community from increased truck traffic and
dust generation.
Implementability
Highest
Few implementability considerations.
Highest
Relatively few implementability
considerations.
Medium
Availability of topsoil for capping of yards
may be limited. Some limitations may be
encountered siting repositories for
contaminated soil.
Lowest
Availability of topsoil for capping of yards may
be limited. Most limitations for siting
repositories for contaminated soil. Complete
removal more difficult than partial removal.
Cost
Total estimated present worth cost =
$5,400,000
Estimated present worth O&M cost = $0
Total estimated present worth cost =
$2,900,000
Estimated present worth O&M cost =
$110,000
Total estimated present worth cost =
$81,000,000
Estimated present worth O&M cost =
$640,000
Total estimated present worth cost =
$123,000,000
Estimated present worth O&M cost = $740,000
State/Tribal Acceptance
Evaluated for the selected remedy in Section 12.7
Community Acceptance
Evaluated for the selected remedy in Section 12.8
Note:
Costs for Alternative S4 differ from those presented for the selected remedy because the analysis of Alternative S4 in the FS included 10 recreational areas and the selected remedy includes 31 residential areas.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-17
Table 10.1-2
Comparison of House Dust Alternatives for Protection of Human Health in Residential and Community Areas
('riU'riiiii
AIUTliali\e 1)1
No Ailion
Alk-rnaliM- 1)2
1 iiliii-iiiiiliiiii Ink-n I'll lion and Yauiiim Loan
Program/Dusl Mais
AlU-rnaliM' 1)3
r.\U-nsiw Cleaning
Overall Protection of
Human Health and the
Environment
Lowest
Unlikely to achieve health risk
goals.
Medium
Likely to be protective where contamination
moderately exceeds action levels and residents
participate in program. Expected to achieve health
risk goals where residents participate in program.
Highest
Most protective alternative. Expected to achieve
health risk goals.
Compliance with ARARs
Not applicable
No ARARs apply to Alternative D1.
Highest
Could be implemented in compliance with ambient
air quality regulations.
Highest
Could be implemented in compliance with ambient
air quality regulations.
Long-Term Effectiveness
and Permanence
Not evaluated
Alternative does not meet the
threshold criteria
Medium
Would be less effective at reducing residual risks
than extensive cleaning. Long-term reliability of
vacuum loan program would depend on participation
of residents.
Highest
Greatest reduction of residual risk. Long-term
reliability would depend on participation of
residents.
Reduction of Toxicity,
Mobility, or Volume
through Treatment
None of the alternatives include treatment
Short-Term Effectiveness
- Short-term impacts to
community and
environment
- Time to achieve RAOs
Low
Short-term impacts to residents and workers could
be limited using health and safety precautions.
Expected to achieve RAOs where residents
participate in program.
Medium
Short-term impacts to residents and workers could
be limited using health and safety precautions.
Expected to meet human health RAOs when
cleaning is implemented.
Implementability
Highest
Administrative and technical feasibility has been
demonstrated in Basin.
Medium
No significant administrative or technical
feasibility difficulties anticipated.
Cost
Total estimated present worth cost = $l,400,000a
Estimated present worth O&M cost = $0
Total estimated present worth cost = $4,300,000
Estimated present worth O&M cost = $0
State/Tribal Acceptance
Evaluated for the Selected Remedy in Section 12.7
Community Acceptance
Evaluated for the Selected Remedy in Section 12.8
aCost for monitoring
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-19
Table 10.1-3
Comparison of Drinking Water Alternatives for Protection of Human Health in Residential and Community Areas
Criterion
Alternate e \\ 1
No Action
Alternate e \\ 2
Public Infnrmalinn
Alternate e \\3
Public Infnniialinii and Residential
Treatment
Alternate e \\4
Public Inrnrmalinn and Alternate e
Source. Public Water I lilil\
Alternate e \\5
Public Inrnrmalinn and
Alternati\e Source, (irnundwaler
Alternate e \\(>
Public Inrnrmalinn and Multiple*
Alternati\e Sources
Overall Protection of
Human Health and the
Environment
Lowest
Would not be protective where
MCLs are exceeded.
Low
Least protective of action-oriented
alternatives.
Medium
Potentially protective, but long-term
effectiveness would be limited by
reliability and maintenance of
treatment units.
Highest
A reliable source of clean water would
be provided at most locations where
MCLs are exceeded. Implementability
would be a limitation at locations far
from a public water source.
Highest
A source of clean water would be
provided at most locations where
MCLs are exceeded.
Implementability would be a
limitation in some areas where no
suitable alternative aquifer exists.
Highest
Clean water would be provided at all
locations where MCLs are exceeded.
Most appropriate technology would
be selected for each site.
Compliance with ARARs
Lowest
Would not comply with ARARs
where MCLs are exceeded.
Lowest
Would not comply with ARARs
where MCLs are exceeded.
Medium
Would usually comply with action-
specific ARARs at locations where
maintenance of treatment units is
conducted, but would not address
groundwater contamination.
Highest
Would comply with action-specific
ARARs in all areas where connection
to a public water source is feasible, but
would not address groundwater
contamination.
Highest
Would comply with action-specific
ARARs in all areas where a suitable
alternative aquifer is present, but
would not address groundwater
contamination.
Highest
Would comply with action-specific
ARARs at almost all locations, but
would not address groundwater
contamination.
Long-Term Effectiveness
and Permanence
Not evaluated
Alternative does not meet the
threshold criteria
Low
Includes no actions to permanently
reduce residual risks where MCLs
are exceeded. Long-term reliability
of institutional controls would be
limited.
Medium
Long-term effectiveness would be
limited by reliability and
maintenance of treatment units.
Highest
Would be very effective and reliable
all areas where connection to a public
water source is feasible.
Medium
Long-term reliability of groundwater
wells may be less than public water
supply.
Highest
Most appropriate technology would
be selected for each site.
Reduction of Toxicity,
Mobility, or Volume
through Treatment
No treatment included
Highest
Most reduction of toxicity using
point-of-use treatment units
No treatment included
No treatment included
Medium
Reduction of toxicity would occur at
locations where point-of-use
treatment units are used.
Short-Term Effectiveness
- Short-term impacts to
community and
environment
- Time to achieve RAOs
Low
Unlikely to achieve RAOs for
drinking water
Highest
Relatively short period to implement,
which would be followed almost
immediately by achievement of
drinking water RAOs.
Medium
Relatively long period to implement in
areas outside of water district, which
would be followed almost immediately
by achievement of drinking water
RAOs.
Medium
Relatively long period to implement
completely, which would be
followed almost immediately by
achievement of drinking water
RAOs.
Highest
Relatively short period to implement,
which would be followed almost
immediately by achievement of
drinking water RAOs.
Implementability
Highest
Few implementability considerations.
Highest
Relatively few implementability
considerations.
Medium
Potential administrative considerations
and limitations on capacity in areas
within water districts. Numerous
administrative and technical
considerations related to designing and
constructing water systems outside of
water districts.
Low
Implementability would be very
limited in areas where no suitable
aquifer exists. Moratoriums on
construction of new wells exist in
some areas.
Highest
Most implementable technology
could be selected.
Cost
Total estimated present worth cost =
$430,000
Estimated present worth O&M cost =
$0
Total estimated present worth cost =
$1,400,000
Estimated present worth O&M cost =
$530,000
Total estimated present worth cost =
$10,000,000
Estimated present worth O&M cost =
$90,000
Total estimated present worth cost =
$2,900,000
Estimated present worth O&M cost =
$160,000
Total estimated present worth cost =
$2,200,000
Estimated present worth O&M cost =
$100,000
State/Tribal Acceptance
Evaluated for the selected remedy in Section 12.7
Community Acceptance
Evaluated for the selected remedy in Section 12.8
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-21
Table 10.1-4
Comparison of Aquatic Food Sources Alternatives for Protection of Human Health
( rilerion
Allernali\e I I
No Action
Allcrnali\c l"2
1 nTonii;ition and Inlem-nlion
Allernali\e l"3
Information and Inlcncnlion and
Monitoring
Overall Protection of
Human Health and the
Environment
Lowest
No reduction in potential
exposure and not protective
Medium
Anticipated to produce some reduction of
exposure. Long-term protectiveness would
primarily depend on reductions of metals in
environmental media.
Highest
Monitoring would be expected to result in a
greater reduction of exposure than Alternative
F2. Long-term protectiveness would primarily
depend on reductions of metals in
environmental media.
Compliance with ARARs
No ARARs specifically address consumption of aquatic food sources.
Long-Term Effectiveness
and Permanence
Not evaluated
Alternative does not meet the
threshold criteria
Medium
Long-term effectiveness primarily depends on
reductions of metals in environmental media.
Program anticipated to last for 30 years.
Medium
Long-term effectiveness primarily depends on
reductions of metals in environmental media.
Program anticipated to last for 30 years.
Reduction of Toxicity,
Mobility, or Volume
through Treatment
None of the alternatives include treatment
Short-Term Effectiveness
- Short-term impacts to
community and
environment
- Time to achieve RAOs
Medium
Remedy could be implemented rapidly;
however, reduction of fish consumption
anticipated to be limited. Minimal impacts to
community or environment.
Highest
Remedy could be implemented rapidly;
monitoring is anticipated to result in greater
reduction of fish consumption in areas of
exposure. Minimal impacts to community or
environment.
Implementability
Highest
Could be readily implemented.
Highest
Could be readily implemented.
Cost
Total estimated present worth cost = $230,000
Estimated present worth O&M cost = $0
Total estimated present worth cost = $910,000
Estimated present worth O&M cost = $0
State/Tribal Acceptance
Evaluated for the Selected Remedy in Section 12.7
Community Acceptance
Evaluated for the Selected Remedy in Section 12.8
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-23
Table 10.2-1
Comparison of Ecological Alternatives for the Upper Basin and Lower Basin
( Million
\llcniiili\c 1
Nil Wliiin
\llcni:ili\c 2
( oiiiiiiii Maliili/c wiih I imil i d
|{cmii\al anil 1 ivalinriil
\llcrnali\r
More l-Ali'iiviM' l{cmii\al. I)K|hin;iI and
1 ivalinriil
\llrrnali\c 4
Maximum l{cmn\al. Divpnval
and Irralmcnl
\llrrnali\r 5
Male nl'Idaho ( Iraniip I'lan
\llrrnali\r (>
Mining < iimiianic" ( lc;inu|> I'lan
Overall Protection of Human
Health and the Environment
Lowest
Not protective
Medium
Intermediate level of long-term effectiveness and
time to achieve RAOs, including ARARs.
Potential short-term impacts and implementability
problems.
Highest
Slightly lower long-term effectiveness and slightly
longer time to achieve RAOs, including ARARs,
compared to Alternative 4 balanced by lesser short-
term impacts and greater implementability.
Highest
Slightly greater long-term effectiveness and
slightly shorter time to achieve RAOs,
including ARARs, compared to Alternative 3
balanced by greater short-term impacts and
reduced implementability.
Low
More protective than Alternative 6, particularly
in 1he Lower Basin, but less protective than
Alternative 2. Lower protectiveness relative to
Alternative 2 balanced by fewer short-term
impacts and implementability concerns.
Low
Least protective of action alternatives.
Compliance with ARARs
Lowest
Would not comply with ARARs
within a reasonable timeframe
Medium
Intermediate time to achieve ARARs compliance.
Estimated times to achieve AWQC 161% and
195% longer than Alternative 4 at Pinehurst and
Harrison, respectively.
Highest
Second shortest time to achieve ARARs
compliance. Estimated times to achieve AWQC
46% and 45% longer than Alternative 4 at Pinehurst
and Harrison, respectively.
Highest
Shortest time to achieve ARARs compliance.
Low
Second longest time to achieve ARARs
compliance. Estimated times to achieve AWQC
198% and 239% longer than Alternative 4 at
Pinehurst and Harrison, respectively.
Low
Longest time to achieve ARARs compliance
among action alternatives. Estimated times to
achieve AWQC 205% and 253% longer than
Alternative 4 at Pinehurst and Harrison,
respectively.
Long-Term Effectiveness and
Permanence
Not evaluated
Alternative does not meet the
threshold criteria
Low
Residual risk includes moderate potential for
future erosion of impacted bed and bank sediments
in Lower Basin and loading from sediments in
Upper Basin. Most wetlands unremediated.
Estimated reductions of dissolved metals load of
30% and 26% at Pinehurst and Harrison,
respectively, at completion of remedy
implementation. Passive water treatment used,
which may be less reliable than active treatment.
Includes cleanup of 1,123 acres of wetland and
lateral lake feeding area. Effectiveness of soil
treatment in Lower Basin is uncertain.
Medium
Substantially greater long-term effectiveness than
Alternatives 2, 5, and 6 due to more extensive
actions to control metals loads from sediments and
river beds. Estimated reduction of dissolved metals
load of 62% and 57% at Pinehurst and Harrison,
respectively, at completion of remedy
implementation. Hydraulic isolation used to limit
loading from inaccessible sediments in Upper Basin,
which may be less reliable than removals. Includes
cleanup of 5,358 acres of wetland and lateral lake
feeding area. Active water treatment used, which
may be more reliable than passive treatment.
Highest
Fewest residual risks. Greatest long-term
effectiveness and permanence as a result of
most widespread use of removal and disposal.
Estimated reduction of dissolved metals load of
73% and 64% at Pinehurst and Harrison,
respectively, at completion of remedy
implementation. Most extensive remediation of
wetlands and lateral lakes. Includes cleanup of
12,469 acres of wetland and lateral lake feeding
area.
Low
Residual risks result from limited actions to
address sediments and associated dissolved
metals loads in Upper Basin. Generally similar
level of long-term effectiveness in Lower Basin
as Alternative 2. Estimated reduction of
dissolved metals load of 13% and 12% at
Pinehurst and Harrison, respectively, at
completion of remedy implementation. Passive
water treatment used, which may be less
reliable than active treatment. Includes cleanup
of 4,682 acres of wetland and lateral lake
feeding area. Effectiveness of soil treatment in
Lower Basin is uncertain.
Lowest
Highest residual risks among action
alternatives, resulting from fewest actions to
address sediments in Upper Basin and
contaminated banks, beds, and wetlands in
Lower Basin. Estimated reduction of dissolved
metals load of 8% and 9% at Pinehurst and
Harrison, respectively, at completion of remedy
implementation. Relies primarily on
institutional controls to reduce waterfowl
exposure to metals. Uses passive water
treatment, which may be less reliable than
active treatment.
Reduction of Toxicity,
Mobility, or Volume through
Treatment
Medium
Drainage from major adits using passive treatment;
no groundwater treatment. Total reduction through
treatment similar to Alternative 5.
Highest
Maximum reduction of water toxicity through
treatment of adit drainage, groundwater, and surface
water.
Highest
Maximum reduction of water toxicity through
treatment of adit drainage and groundwater.
Medium
Drainage from major adits using passive
treatment; no groundwater treatment. Total
reduction through treatment similar to
Alternative 2.
Low
Wetlands treatment of drainage from four adits.
Least reduction of toxicity through treatment of
action alternatives.
Short-Term Effectiveness
- Short-term impacts to
community and
environment
Medium
Intermediate level of potential short-term water
quality impacts. Moderate potential for short-term
habitat loss. Greater potential risks to community
from increased truck traffic and dust generated by
remedial activities than Alternatives 5 and 6.
Low
Substantial potential for short-term water quality
impacts, especially from river bed dredging, and for
short-term loss of habitat. Second greatest potential
risks to community from increased truck traffic and
dust generated by remedial activities among
alternatives.
Lowest
Greatest potential for short-term water quality
impacts and short-term loss of habitat. Greatest
potential risks to community from increased
truck traffic and dust generated by remedial
activities among alternatives.
Medium
Relatively little potential for short-term water
quality impacts. Moderate potential for short-
term habitat loss. Relatively few risks to the
community from remedy implementation.
Highest
Relatively little potential for short-term water
quality impacts or habitat loss. Relatively small
risks to the community from remedy
implementation.
- Time to achieve RAOs
Low
Longer implementation period than Alternative 5,
but shorter period of natural recovery would be
needed to achieve surface water RAOs.
Medium
Relatively long implementation period, but
soil/sediment RAOs would be achieved at most
locations, and a relatively short period of natural
recovery would be needed to achieve surface water
RAOs.
Medium
Longest implementation period, but
soil/sediment RAOs would be achieved at the
largest number of locations, and the shortest
period of natural recovery would be needed to
achieve surface water RAOs.
Low
Relatively short implementation period, but
soil/sediment RAOs would be achieved at a
limited number of locations, and a long natural
recovery period would be needed to achieve
surface water RAOs.
Lowest
Relatively short implementation period, but
soil/sediment RAOs would be achieved at
relatively few locations, and the longest natural
recovery period would be needed to achieve
surface water RAOs.
Implementability
Medium
Potential concerns with availability of topsoil (or
other growth media) and clean fill needed for
revegetation of removal areas and repositories.
Siting of repositories with 2.5 million cy capacity
may be feasible. Potential problems with feasibility
of sediment removals.
Low
Limited availability of topsoil (or other growth
media) and clean fill needed for revegetation of
removal areas and repositories. Substantial siting
problems associated with 26 million cy of repository
capacity. Potential problems with feasibility of
sediment removals and hydraulic isolation.
Lowest
Greatest implementability problems related to
availability of materials, technical feasibility,
and siting of repositories with 67 million cy of
capacity.
Highest
Relatively small materials requirements. Siting
of repositories with 1.4 million cy capacity
should be feasible.
Highest
Least materials requirements. Siting of
repositories with 260,000 cy capacity should be
feasible.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-25
Table 10.2-1 (Continued)
Comparison of Ecological Alternatives for the Upper Basin and Lower Basin
( rili-iion
Allcniuliw' 1
No Wliiin
\llcni:ili\c 2
( niiiiiiii si;iliili/r willi 1 imilcil
UciikimiI mill 1 iv;ilmi-ill
Allcrii:ili\('
Miuv l \li-nvi\r UciiiiimiI. l)i<.|niMil mill
1 n-;il nil-ill
AllcnimiM' 4
M:i\iiiiiiin UriiKiMil. l)i»|io»:il
mill 1 iviilinriil
Allcrnmi\c 5
Nliilr <>t" IiLiIio ( Irmiup I'lmi
Allcrnmi\c (>
Mining ( Miii|Kinii-N < li-mni|> I'lmi
Cost
Total estimated present worth cost 70.000.000
Estimated present worth O&M cost = $44,000,000
I'olal eslimaled present worth cost $1,300,000,000
Estimated present worth O&M cost = $133,000,000
I'olal eslimaled present worth cost
$2,600,000,000
Estimated present worth O&M cost =
$200,000,000
I'olal eslimaled present worth cosl
$257,000,000
Estimated present worth O&M cost =
$25,000,000
Total estimated present worth cost =
$194,000,000
Estimated present worth O&M cost =
$21,000,000
State/Tribal Acceptance
Evaluated for the selected remedy in Section 12.7
Community Acceptance
Evaluated for the selected remedy in Section 12.8
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-27
Table 10.3-1
Comparison of Alternatives for Coeur d'Alene Lake
( rilciiciii
\llcniilli\c 1
Nil U'linii
\llcni:ili\c 2
Impli-mcnl 1;ikr Miiiiiigrmciil I'Liii
Overall protection of human health
and the environment
Low
Potentially not protective of human health and the environment. Includes
no measures to control nutrients, which may affect the rate of release of
metals from the lake bed sediments.
Medium
Potentially protective of human health and the environment. Includes measures
to control nutrients, which may reduce the rate of release of metals from the
extremely large volume of contaminated lake bed sediments compared to no
action.
Compliance with ARARs
Low
Potentially higher rate of release of metals compared to Alternative 2
may result in longer time to achieve AWQC.
Medium
Potentially lower rate of release of metals compared to Alternative 1 may result
in shorter time to achieve AWQC.
Long-term effectiveness and
permanence
Lowest
Includes no actions to reduce residual risk
Medium
Includes measures to potentially reduce release of metals from lake bed
sediments. Long-term reliability would depend on continued enforcement of
institutional controls designed to reduce nutrient loads.
Reduction of toxicity, mobility, or
volume through treatment
Lowest
No treatment included
Medium
Although specific sources have not been identified, the Lake Management Plan
contains provisions for treatment of sources of nutrients.
Short-term effectiveness
Protection of community, workers,
environmental impacts
Time to achieve RAOs
Highest
No impacts to community, workers or environment
Low
Includes no actions to reduce the time to meet surface water RAOs
Medium
Actions identified under the Lake Management Plan may result in risks to
community and workers and environmental impacts.
Medium- Reductions in nutrient loads would potentially reduce time to achieve
surface water RAOs.
Implementability
Highest
No implementability considerations
Low
Implementation may require passage of new ordinances and coordination
between agencies. There may be private property ownership issues for some
actions.
Cost
Total estimated present worth cost = $1,300,000 (see note)
Estimated present worth O&M cost = $1,300,000 (see note)
Total estimated present worth cost = $8,800,000
Estimated present worth O&M cost = $8,800,000
State/Tribal Acceptance
Evaluated for the Selected Remedy in Section 12.7
Community Acceptance
Evaluated for the Selected Remedy in Section 12.8
Note: Estimated costs for Alternative 1 include costs for monitoring.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 10.0
Page 10-29
Table 10.4-1
Comparison of Alternatives for the Spokane River
Criterion
Alternate e 1
No Action
Allcrnali\c 2
1 list il ii (iona 1 Controls
Alternate e 3
Containment with Limited Kcmo\al
and Disposal
Alternate e 4
More K\tcnsi\e Kemo\al. Disposal,
and Containment
Alternate e 5
Maximum Kemo\ aland Disposal
Overall Protection of
Human Health and the
Environment
Lowest
Would not be protective.
Lowest
May be ineffective in reducing risks to
humans. Would not reduce risks to
ecological receptors.
Medium
Would effectively contain sediments posing
risks to humans, and would effectively
contain some, but not all, sediments posing
risks to ecological receptors.
Medium
Removal and disposal of sediments would
provide more reliable protection of humans
as well as ecological receptors in critical
habitat areas compared to Alternative 3.
Highest
Removal and disposal of all sediments
posing significant human health and
ecological risks would provide the most
reliable protection.
Compliance with ARARs
Lowest
Would not comply with ARARs for
sediments.
Lowest
Would not comply with ARARs for
sediments.
Medium
Would comply with ARARs for sediments.
Medium
Would comply with ARARs for sediments.
Complies with MTCA, including MTCA
requirement to use permanent solutions to
the maximum extent practicable.
Highest
Would comply with ARARs for sediments.
Complies with MTCA, including MTCA
requirement to use permanent solutions to
the maximum extent practicable.
Long-Term Effectiveness
and Permanence
Not evaluated
Alternative does not meet the threshold
criteria.
Not evaluated
Alternative does not meet the threshold
criteria.
Low
Moderate residual risks to ecological
receptors. Low residual risks to humans.
Moderate maintenance requirements. Some
additional actions due to recontamination
could be needed.
Medium
Low residual risks to humans and ecological
receptors. Moderate maintenance
requirements. Some additional actions due
to recontamination could be needed.
Highest
Very low residual risks to humans and
ecological receptors. No long-term
maintenance requirements. Some additional
actions due to recontamination could be
needed.
Reduction of Toxicity,
Mobility, or Volume
through Treatment
None of the alternatives include treatment
Short-Term Effectiveness
- Short-term impacts to
community and
environment
- Time to achieve RAOs
Highest
Limited short-term impacts to community
and environment resulting from hauling and
construction activities within the floodplain.
Low
Longest time to achieve RAOs among the
action-oriented alternatives.
Medium
Limited short-term impacts to community
from hauling, but potentially significant
impacts to the environment from
construction activities within the floodplain.
Medium
Second shortest time to achieve RAOs.
Low
Limited short-term impacts to community
from hauling, but most significant impacts to
the environment from construction activities
within the floodplain.
Highest
Shortest time to achieve RAOs
Implementability
Highest
No significant technical or administrative
feasibility concerns. Services and materials
readily available.
Highest
No significant technical or administrative
feasibility concerns. Services and materials
readily available.
Medium
Potentially somewhat greater feasibility
considerations due to larger scope of actions.
Potential limitations on local landfill
capacity.
Cost
Total estimated present worth cost =
$900,000
Estimated present worth O&M cost =
$890,000
Total estimated present worth cost =
$1,800,000
Estimated present worth O&M cost =
$940,000
Total estimated present worth cost =
$6,500,000
Estimated present worth O&M cost =
$1,300,000
Total estimated present worth cost =
$28,000,000
Estimated present worth O&M cost =
$1,700,000
State/Tribal Acceptance
Evaluated for the selected remedy in Section 12.7
Community Acceptance
Evaluated for the selected remedy in Section 12.8
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 11.0
Page 11-1
11.0 PRINCIPAL THREAT WASTE
Principal threat wastes are those source materials considered to be highly toxic or highly mobile
that generally cannot be reliably contained and/or would present a significant risk to human
health or the environment should exposure occur.14 Principal threat materials in the Coeur
d'Alene Basin may include, for example, metal concentrates spilled during mill operations or in
transport to smelters. A time-critical removal action was conducted in 1999 to address all known
surface concentrates associated with rail transport along the Wallace-Mullen Branch of the
UPRR. If additional concentrates or other materials that meet the definition of principal threat
waste are encountered during remedy implementation, these materials would be managed in a
manner that is protective of human health and the environment and consistent with the NCP.15
The NCP establishes an expectation that EPA will use treatment to address the principal threats
posed by a site wherever practicable (NCP§300.430(a)(l)(iii)(A)). Where EPA determines that
it is not practicable to use treatment to address principal threat waste, such waste may be
transported off-site, consistent with the Off-Site Disposal Rule, 40 CFR 300.440, or managed
safely on-site, consistent with all ARARs identified in Section 13.2 of this ROD.
14 Additional information for defining principal threat wastes can be found in U SEP A (199 lb) "A Guide to Principal
Threat and Low Level Threat Wastes."
15 Concentrations used to identify principal threat waste within the Bunker Hill Box were: 127,000 ppm antimony;
15,000 ppm arsenic; 71,000 ppm cadmium; 84,600 ppm lead; 33,000 ppm mercury (Source: Bunker Hill Non-
Populated Areas ROD, ROD ID: EPA/ROD/R10-92/041, Date: 09/22/1992). Additional factors (e.g., mobility,
repository waste acceptance criteria, etc.) should be evaluated on a site-specific basis prior to disposal of material
associated with implementing the Selected Remedy.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-1
12.0 SELECTED REMEDY
This section presents the rationale, description, estimated costs, and expected outcomes of the
Selected Remedy, which includes interim measures. The Selected Remedy is identified in
Table 12.0-1.16 The Selected Remedy in accordance with 40 CFR 300.430(a)(i)(B) includes
final remedial actions for human health in the community and residential areas, including
identified recreational areas, of the Basin upstream of Coeur d'Alene Lake (the Upper Basin and
Lower Basin) as well as final remedial actions for all of the human health remedy upstream of
Upriver Dam and all of the environmental remedy from the Idaho/Washington border to Upriver
Dam. The remedial action selected by this ROD for environmental protection in the Upper Basin
and Lower Basin will neither be inconsistent with nor preclude implementation of the final
remedy which will be identified in subsequent decision documents. The remedy selected by
EPA was developed through comprehensive discussions among EPA, states, tribes, federal
trustees, and the public, including the Idaho-led Consensus-Building Process.
State legislation under the Basin Environmental Improvement Act established the process for the
formation of the Basin Environmental Improvement Project Commission. This commission
includes federal, state, tribal, and local governmental involvement. EPA anticipates working as a
member of this commission for implementation of the ROD and development of priorities and
sequencing of cleanup activities.
The Selected Remedy is described in four parts:
Section 12.1: Protection of Human Health in the Community and Residential Areas of the
Upper Basin and the Lower Basin
The Selected Remedy includes all of the remedy for protection of human health in the
community and residential areas, including identified recreational areas. No further actions for
protection of human health in community and residential areas are anticipated. Certain potential
exposures outside of the community and residential areas of the Upper Basin and Lower Basin
are not addressed by this ROD, and will continue to present risks of human exposure to
hazardous substances. These potential exposures impacting human health include:
16 The estimated costs in this table and in subsequent detailed cost estimate tables are based on the best available
information regarding the anticipated scope of the remedial alternative. 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.
Changes may be documented in the form of a memorandum in the Administrative Record file, an ESD, or a ROD
amendment. This is an order-of-magnitude engineering cost estimate that is expected to be within +50 to -30
percent of the actual project cost, consistent with RI/FS guidance.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-2
• Recreational use at areas in the Upper Basin and Lower Basin where cleanup
actions are not implemented pursuant to this ROD
• Subsistence lifestyles, such as those traditional to the Coeur d'Alene and Spokane
Tribes
• Potential future use of groundwater that is presently contaminated with metals
Section 12.2: Environmental Protection in the Upper Basin and Lower Basin
For environmental protection, an adaptive management strategy has been adopted for the Upper
Basin and the Lower Basin. The Selected Remedy consists of approximately 30 years of
prioritized actions designed to achieve benchmarks for environmental protection. These actions
will be implemented concurrently with the human health actions.
The Selected Remedy includes benchmarks for ecological protection; however, the long-term
goals are to provide full protection of the environment as well as to return the opportunity for
individuals to practice subsistence lifestyles without limits from mining contamination. During
the five-year review process and at the end of this approximately 30-year period, EPA will
evaluate and decide whether any additional remedial actions under CERCLA are necessary to
attain ARARs and to provide for the protection of human health and the environment, and
whether any ARAR waivers should be applied.
Section 12.3: Coeur d'Alene Lake
The Selected Remedy does not include remedial actions for Coeur d'Alene Lake. State, tribal,
federal, and local governments are currently in the process of implementing a Lake Management
Plan outside of the Superfund process using separate legal authorities.
Section 12.4: Spokane River
The beaches and wading areas adjacent to the Idaho portion of the Spokane River were sampled
in 1998 and were found to be safe; i.e., concentrations of metals did not exceed risk-based levels
for recreation. The Selected Remedy for the Spokane River includes all of the human health
remedy upstream of Upriver Dam and all of the environmental remedy from the
Idaho/Washington border to Upriver Dam. Additional sampling is included in the Selected
Remedy to determine the need to address areas upstream of the state line for environmental
protection and downstream of Upriver Dam for human health and environmental protection.
Quantification of risks to persons, including Spokane tribal members, and others who may
practice a subsistence lifestyle in the Spokane River area, was not part of the RI/FS
investigations. EPA and the Spokane Tribe are cooperating in planning additional testing and
studies that will be implemented to evaluate the potential exposures to subsistence users. The
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-3
results of those tests and studies will determine appropriate future response actions to be taken, if
any.
Management of materials generated by cleanup activities is described in Section 12.5, and
monitoring is described in Section 12.6.
The cleanup actions selected in this ROD will be sequenced during the approximately 30 years
of cleanup. Some of the considerations for the sequencing of the cleanup include the following:
• Cleanup of community and residential areas, including the identified recreational
areas, to minimize human health exposure is a top priority. Input from local
community residents will be considered as the remedy is implemented. It is
anticipated that cleanup of these areas will be conducted concurrently with the
ecological remedy.
• Some cleanup actions related to ecological protection will require additional
information to fill data needs prior to initiating the cleanup.
• Downstream areas subject to recontamination will generally be cleaned up after
upstream sources of contamination have been stabilized; however, cleanup in
some downstream areas will be conducted prior to completion of upstream source
stabilization. Examples include river bank stabilization and waterfowl feeding
areas with high use and relatively low recontamination potential.
• The level of funding available will influence the rate and extent of cleanup
actions.
• The sequencing of remedial actions will consider the need to limit short-term
impacts to the communities and provide certainty to communities for commerce
and economic stability.
As the Selected Remedy is implemented, additional information will become available, and the
specific actions taken could differ from those currently envisioned, based on this additional
information. If changes to the remedy are selected, the changes can be documented in one of
three ways. Examples of the changes and documentation requirements are given on page 6-58 of
the EPA guidance document (USEPA 1999a).
• Non-significant or minor changes will be documented in the site file. Depending
on the nature of the change, EPA may also prepare a fact sheet for public
distribution. Non-significant or minor changes do not undergo formal public
review and comment.
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• Significant changes will be documented in an ESD. A notification and
description of the ESD will be published in major local newspapers. The ESD
will be made available to the public by placing it in the Administrative Record file
and information repository. Although not required, EPA may elect to hold an
additional public comment period or public meeting on the planned ESD.
• Fundamental changes will be documented in a ROD Amendment. A revised
Proposed Plan will be published that highlights the proposed changes. The
portion of the ROD being amended will be evaluated using the nine CERCLA
evaluation criteria. EPA will conduct the public participation and documentation
procedures specified in the NCP. The final decision to amend is not made until
after consideration of public comment.
The following sections describe the Selected Remedy for protection of human health and the
environment in the Coeur d'Alene Basin.
12.1 HUMAN HEALTH PROTECTION IN THE COMMUNITY AND RESIDENTIAL
AREAS OF THE UPPER BASIN AND THE LOWER BASIN
Exposures to lead in soil and dust from the home, surrounding communities, and recreational
areas are the primary human health concerns in the affected communities in the Basin. In
particular, preventing excessive lead exposures in young children and pregnant women is a top
priority. Table 12.1-1 shows the estimated number of residences in the Basin with lead
concentrations in yard soil that require remediation. Additional human health concerns include
arsenic in residential soils, lead in fish from the lateral lakes, and metals such as cadmium,
arsenic, and lead in shallow drinking water wells in the side gulches and main valley of the
Upper Basin and floodplain areas of the Lower Basin.
EPA has selected a remedy for protection of human health in the community and residential
areas that consists of the following elements, which are summarized in Table 12.1-2:
• Soil and house dust: Alternatives S4 (Information and Intervention and Partial
Removal and Barriers) and D3 (Information and Intervention, Vacuum Loan
Program/Dust Mats, Interior Source Removal, and Contingency Capping/More
Extensive Cleaning)
• Drinking water: Alternative W6 (Public Information and Multiple Alternative
Sources)
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• Aquatic food sources: Alternative F3 (Information and Intervention and
Monitoring)
The Selected Remedy is the complete human health remedy in the community and residential
areas, including identified recreational areas. This remedy also was the Preferred Alternative in
the Proposed Plan. It is the most appropriate remedy because:
• The remedy satisfies the CERCLA threshold criteria and provides the best
balance of tradeoffs with respect to the CERCLA balancing and modifying
criteria
• The remedy satisfies the statutory requirements outlined in CERCLA §121
12.1.1 Description of the Selected Remedy
This section describes the Selected Remedy for soil and house dust, drinking water, and aquatic
food sources, including institutional controls.
Soil and House Dust
Young children are primarily exposed to lead in dust on the floors of their homes (CDC 1991,
Manton et al. 2000, Succop et al. 1998, Lanphear et al. 1998). Lead in house dust reflects
contaminated soil from the yard, neighborhood, and surrounding community (IDHW 2001a,
IDHWDG 1999). Preventative actions include source removal and containment inside and
outside the home. Remedies that do not include source removal and containment would not
adequately prevent exposure. A long-term basin-wide institutional controls program, as well as
actions to prevent recontamination, will be implemented to maintain the integrity of the human
health remedy.
The Selected Remedy, which is consistent with the remedy developed by the State of Idaho,
incorporates experience from successful cleanup actions within the Bunker Hill Box. For
example, removal of contaminated yard soil has been shown to be effective in reducing house
dust concentrations in the Box for a large number of homes. Figure 12.1-1 shows Smelterville
soil and dust lead geometric means for the years 1990 to 2001 in homes with children
participating in the LfflP.
Soil Action Levels. As described in Section 7.0 of this ROD, the Box model was used to
develop the action level for lead in soil, which was established to reduce exposure pathways so
that a typical child would have a 5 percent or less probability of a blood lead level greater than
10 |ig/dL and a 1 percent or less probability of a blood lead level greater than 15 |ig/dL. A tiered
approach to lead soil cleanup levels was developed based on the results of the model. The Box
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model supported a soil remediation level for lead starting at approximately 700 mg/kg.
Therefore, for soil with lead concentrations between 700 mg/kg and 1,000 mg/kg, a barrier (such
as vegetation) will be required to prevent direct exposure to soil and migration of soil to dust in
homes. For soil with lead concentrations above 1,000 mg/kg, partial removal and a soil barrier
will be required. This tiered approach was developed after considering a number of factors, such
as protectiveness, implementability, cost-effectiveness, and community acceptance.
Section 7 of this ROD also evaluated human health risks from arsenic in residential soils. A
number of factors were considered to select a soil arsenic cleanup level for this site, including the
nature and extent of site contamination, the nature of human health risks, the exposure pathways,
and the potential impacts and costs associated with physical remediation activities in the
community. A range of arsenic soil concentrations from 64 mg/kg (1 in 10,000 cancer risk) to
123 mg/kg (non-cancer risk) was identified as protective of human health based on a residential
soil ingestion and dermal exposure scenario. EPA selected an arsenic soil cleanup level of 100
mg/kg, which is within the acceptable human health risk range and represents a balancing of
factors for an arsenic soil remediation level at which engineering actions (e.g., soil removal)
should begin at this site. It is estimated that a small percentage of residential yards in the Basin
have arsenic soil concentrations above 100 mg/kg that are not co-located with lead above
700 mg/kg. Recreational areas with arsenic levels in excess of 100 mg/kg will be prioritized for
cleanup based on use.
In addition, Section 7 also discussed cadmium concentrations in some homegrown vegetables
that exceed target health goals. Since lead and cadmium are co-located in garden soil, the
Selected Remedy will address risks associated with cadmium levels in homegrown vegetables
through the cleanup of lead-contaminated garden soil.
Remedy Components. The Selected Remedy for soil and house dust is composed of the
following components:
Sampling
Remediation of residential yards
Remediation of street rights-of-way
Remediation of commercial properties and common use areas
Remediation of recreational areas
Dust suppression during remedial activities
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• Disposal of contaminated materials
• Health intervention program
• Remediation of interior house dust, if necessary
• Relocation, if necessary
Sampling. Prior to initiating remedial actions on a specific property, soil sampling will be
completed. House dust sampling will be initiated for homes with young children or pregnant
women in residence (as part of the health intervention services described in this section). Soil
sampling will be conducted in accordance with established sampling procedures for the site, and
will occur on a yard-by-yard basis. Property owners in the Basin will be able to request soil
sampling and the results will be made available to them in a timely manner. Only those
properties with soil sampling results above the soil action levels will require remediation.
Residential Yards. Yard soil with lead concentrations between 700 mg/kg and 1,000 mg/kg will
require a barrier, such as vegetation, that will need to be continuous and sustainable with no bare
soil exposed. The barrier will also need to reduce direct exposure to contaminated soil and
migration of soil to dust in homes. In general, yard soil with lead concentrations greater than
1,000 mg/kg or arsenic concentrations greater than 100 mg/kg will be removed to a depth of one
foot and backfilled with clean soils. For those yards with contamination at depth, a visual
marker will be placed prior to backfilling. In contaminated garden areas, clean soil will be
provided to a depth of two feet.
For each residential yard, the exact nature of the remediation (e.g., depth of excavation, which
bushes to remove) will be considered on a case-by-case basis. However, for consistency, the
following areas will generally be remediated within each yard:
Sod areas
Road shoulders (if curb and gutter are not present) to asphalt or pavement and to
the lateral extension of property lines
Alleys (if unpaved) to the extension of the lot lines
Landscaped areas
Garden areas
Unpaved driveways
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• Play areas
• Garages with dirt floors
• Storage areas
During the excavation process, all existing sod and soil coverings will be removed and disposed
of along with the soil. Larger trees and shrubs generally will be left in place. After soil removal
and backfilling, the yard will be revegetated. Lawn areas of remediated yards will generally be
revegetated with sod. Steep hillsides not currently planted with vegetation will be stabilized and
hydroseeded with native grasses. To the extent practicable, all yard landscaping will be returned
to its original condition. The maintenance of barriers will be the responsibility of the property
owners.
The cleanup of residential yards includes drainage improvements to ensure that contaminated
material from areas yet to be cleaned is not transported to remediated areas. These drainage
improvements will improve the long-term protectiveness of the partial removals.
Where appropriate, the exteriors of structures will be pressure-washed before remedial measures
are performed to reduce the potential for recontamination from lead-based paint. This will be
coordinated with the Department of Housing and Urban Development paint abatement programs.
Programs for paint abatement and stabilization will be coordinated with the soil cleanup and
sequenced to mitigate exposures as quickly as possible while limiting the possibility of
recontamination.
Street Rights-of-Way. All ROWs within the Site will be managed to minimize exposure and
contaminant migration. The remedial action determinations for ROWs will be based on location,
use, and contaminant concentrations. In general, all contaminated ROWs will be addressed by a
combination of access controls, capping (barriers consistent with land use), or
removal/replacement. ROWs include all state, county, local, and private roads.
Commercial Properties and Common Use Areas. Commercial properties and common use
areas include public buildings, parks, playgrounds, churches, and commercial buildings. Risks
posed by commercial properties and common use areas are similar to those in residential
settings; therefore, the cleanup actions for these properties will be similar to those proposed for
residential yards. A combination of removals, barriers, and access restrictions will be used at
commercial properties and common use areas based on location, use, and contaminant
concentrations. Barriers will include vegetation, a minimum of six inches of clean soils or
gravel, or a paved surface. Final decisions regarding barrier performance standards will be
developed during remedial design or as a component of the institutional controls program.
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Commercial properties used predominantly by sensitive populations will require a 12-inch soil
barrier.
Recreational Areas. Formal recreational areas such as boat ramps, picnic areas, and
campgrounds with surface soil containing lead concentrations greater than 700 mg/kg will be
capped. Recreational areas with arsenic levels above 100 mg/kg will be prioritized for cleanup
based on use. Vegetative barriers will not be used at formal recreational areas due to
maintenance concerns related to the high traffic and use of these areas. Soils in recreational
areas also may be excavated, if appropriate. Figure 12.1-2 shows the locations of the 31
recreational areas in the Lower Basin that have been prioritized for cleanup. Other recreational
areas may be evaluated for cleanup based on factors such as risk of exposure, location, and use.
It is important to note that there are other areas identified in this ROD, specifically mine and mill
sites in the Upper Basin and recreational areas along the Spokane River in Washington State, that
include cleanup activities to protect human health. These areas and the estimated costs
associated with their cleanup activities are summarized in Sections 12.2 and 12.4, respectively.
Dust Suppression for Remedial Activities. Dust suppression measures will be implemented
throughout the remediation process to reduce exposure of workers and residents to airborne
contaminants. Dust suppression will include, but not be limited to:
• Watering of residential yard areas prior to excavation activities
• Watering during excavation, as necessary
• Placement of tarps or covers over excavated materials
• Use of tarps or covers over truck beds to reduce blowing dust and spillage during
transportation to the waste repository
• Daily cleanup of all spilled or tracked soils from sidewalks, roadways, etc.
Disposal of Contaminated Materials. Contaminated materials will generally be disposed of in
repositories located within the Basin. A process for evaluating repository locations and design
requirements is described in Section 12.5 of this ROD. EPA and the State of Idaho will work
with affected citizens and other Basin stakeholders in the development and selection of
repository locations.
Health Intervention Program The Selected Remedy will include a lead health intervention
program similar to the Bunker Hill Box LHIP, which provides personal health and hygiene
information and vacuum cleaner loans to help mitigate exposure to contaminants. The
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intervention program will include monitoring dust levels and lead concentrations in homes with
young children or pregnant women during implementation of the Selected Remedy. The
monitoring data will be used to direct nurse visits before lead exposure and blood lead
concentrations peak in the late summer. This targeted education effort will be an added measure
to mitigate exposure while the cleanup process is ongoing. The decision process for evaluating
homes that will require intervention activities is described in Figure 12.1-3. The process is based
on dust mat monitoring results, and includes consideration of the rate of dust entering homes
(dust loading rate g/m /day) and the concentration of lead in the dust entering the homes
(mg/kg). The HHRA identified lead loading rates as a strong predictor of blood lead levels.
Along with age, lead loading rates accounted for 50 percent of the variability in blood lead levels
observed in the Basin. The lead loading rate is the product of the dust loading rate and the dust
lead concentration. Considering both dust loading rate and dust lead concentration provides
more information than using lead loading rates alone.
The LHIP also provides a voluntary, annual blood-lead screening program that is funded by
ATSDR. The results of the annual screening are evaluated to identify and serve children with
elevated blood lead levels. The results of the blood lead screening program indicate that average
blood lead levels, and the percentage of children in the Basin with elevated blood leads, have
remained fairly stable from 1996 through 2000 despite varying participation rates. In 2001, the
screening results showed declines in both the average blood lead levels and the percentage of
children with elevated blood lead levels. It is important to note that only about 2 percent to
25 percent of eligible children, depending on the year, have been tested annually in the Basin
over the last 5 years. This compares to more than 50 percent of eligible children who have been
tested in the Box since 1988. More than 4,000 children in the Box have participated in blood
lead surveys since 1988, compared to approximately 420 children in the Basin since 1996.
Blood lead screening will continue to be offered to identify and treat families with excessive lead
exposures, and it is hoped that annual participation rates will increase. The results of the blood
lead screening program are shown by year on Tables 12.1-3 through 12.1-8 for 1996 - 2001 and
summarized for all years on Table 12.1-9.
Interior House Dust. It is expected that soil remediation, including covers of one foot of clean
soil or barriers, will substantially reduce lead concentrations inside each home. However, once
yard cleanups are completed and lead soil concentrations have been reduced at all contaminated
properties, it is possible that some homes will have dust lead levels requiring interior cleaning.
For these homes, a contingency of interior cleaning and paint abatement (available via a state
program) will be available (FS Alternative D3). Several factors will be considered to determine
if interior house dust cleaning is required, such as an evaluation of the concentration of lead in
the dust entering homes (dust lead concentrations), the amount of dust entering homes (dust
loading rate g/m /day), and lead loading rates. Currently, these measurements are based on dust
mat monitoring results. As previously mentioned, the lead loading rate is the product of the dust
loading rate and the dust lead concentration. Cost estimates for dust abatement of these homes
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are based on the Smelterville house cleaning pilot study (IDEQ 2001). The unit costs are
expected to decrease if a lower level of cleaning proves to be effective, and as a result of the
economy of scale of cleaning a larger number of homes.
Relocation. Relocation is proposed as a last resort for homes with contamination above action
levels, where extensive recontamination is likely, or where adequate cleanup would be extremely
difficult. For the vast majority of homes that fall above the action level, every effort will be
made to find a way to ensure that the preferred soil alternative is effective in the long term. The
governments will work with individual families and property owners to find the best solution.
Drinking Water
Prior to initiating drinking water response actions, drinking water sampling will be completed for
homes on private wells. Basin property owners on private wells will be able to request drinking
water sampling, and the results will be made available to them in a timely manner. To reduce
current exposure to metals in drinking water, an alternate water supply will be provided to
residences or areas where the existing water supply contains metals at concentrations greater
than the drinking water standards shown in Table 8.1-2. Residences with affected private wells
within water districts will be connected to the existing public water supply system. For
residences outside of water districts (mostly in the tributary gulches), the alternate water supply
will most likely consist of point-of-use treatment or new groundwater wells installed into a
suitable aquifer. The estimated numbers of residences with drinking water containing metals at
concentrations exceeding one or more MCL are shown in Table 12.1-10.
Actions for protection of groundwater and potential future drinking water supplies are not
addressed as part of the Selected Remedy.
Aquatic Food Sources
The potential for lead exposure by consumption of fish and other aquatic food sources (e.g.,
water potatoes) will be managed through educational resources available to fishermen and other
recreational users and health advisories for subsistence fishing. The educational resources and
advisories will be issued by the IDHW and include information about the potential health risk of
consuming contaminated fish caught from lateral lakes. IDHW and ATSDR will review the
levels of metals in aquatic food sources to determine if education or consumption advisories are
warranted. A fish consumption advisory already exists in the Lower Basin and along part of the
Spokane River. The Selected Remedy also includes monitoring of metals in fish tissue from fish
caught in Coeur d'Alene Lake to determine if fish are safe to eat by simulating tribal and
recreational fish consumption. Reductions in the levels of metals in fish are expected to occur as
a result of implementation of the ecological remedies but may not be sufficient to adequately
reduce human health risks in the short term.
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Institutional Controls
Institutional controls will be required to limit future exposures to contaminated soil that is left in
place and groundwater not addressed by the Selected Remedy. It is anticipated that the existing
Institutional Controls Program (ICP) in the Box will be used as a model for the Basin. The ICP
includes records maintenance, permitting, surveillance, inspections, and local construction
regulations developed and implemented in conjunction with local zoning, building, or planning
commissions. For drinking water, expansion of the Bunker Hill "area of drilling concern" will
advise drillers of the nonpotable nature of contaminated aquifers. For commercial and
residential development, permitting will ensure that a local entity could evaluate the area for
development and require standardized measures to prevent exposure to contaminants.
Implementation of the Selected Remedy
As implementation of the human health remedy moves forward, EPA and the State of Idaho,
along with other stakeholders, will continue to work together to develop innovative and common
sense approaches that meet the remedial action objectives. For example, the State of Idaho has
developed a pilot program that will: (1) conduct a review of potential residential lead exposures
(including interior and exterior lead sources), (2) develop remedial plans tailored to specific
residential conditions, (3) increase involvement of homeowners in the remediation of their yards,
and (4) create business opportunities for local contractors and workers. The first step will be to
coordinate with property owners to request access for sampling of residential properties to better
assess the need and locations for residential remedial actions. EPA is supportive of cleanup
approaches that increase community support and participation while also meeting the goals of
protection of human health and the environment. EPA and the State of Idaho will continue to
work together to ensure that these shared goals are met during implementation of the Selected
Remedy.
12.1.2 Estimated Remedy Costs
The estimated remedy costs are summarized in the following tables:
• Tables 12.1-11 through 12.1-14: Summaries of Estimated Costs for Soil and
House Dust. The total estimated present worth cost for the Selected Remedy for
soil and house dust, including yards, infrastructure, repositories, rights-of-way,
commercial properties, and recreation areas, is $89,000,000. The net present
worth of 30 years of operation and maintenance (O&M) is $920,000.
The total estimated present worth cost includes $21,000,000 for vegetative
barriers and partial soil removals, $1,400,000 for information and
intervention, $970,000 for drainage improvements, $3,200,000 for potential
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recontamination, $2,700,000 for repositories, $2,100,000 for mobilization,
$2,300,000 for administration, and $10,000,000 for contingencies. The
estimated present worth O&M cost for repositories is $200,000. The total
estimated present worth cost for cleanup of residential soils is $44,000,000.
The total estimated present worth cost for street rights-of-way, commercial
properties, and common areas is $35,000,000. The estimated present worth
O&M cost is $0.
The total estimated present worth cost for recreation areas is $5,900,000. The
estimated present worth O&M cost for recreational areas is $720,000.
The total estimated present worth cost for house dust programs is $4,300,000.
The estimated present worth O&M cost of the house dust programs is $0.
• Table 12.1-15: Summary of Estimated Costs for Drinking Water. The total
estimated present worth cost for the Selected Remedy for drinking water is
$2,200,000. The net present worth of 30 years of O&M is $100,000.
• Table 12.1-16: Summary of Estimated Costs for Aquatic Food Sources. The total
estimated present worth cost for the Selected Remedy for aquatic food sources is
$910,000. The net present worth of 30 years of O&M is $0.
The estimated total present worth cost for the human health Selected Remedy is $92,000,000.
The estimated net present worth of 30 years of O&M is $1,000,000.17
The costs presented are present worth costs. The present worth cost is the sum of the present
value of the capital costs and the present value of the O&M costs over the period of performance.
Consistent with current CERCLA guidance, estimates of present worth costs assume a discount
rate of 7 percent (USEPA 2000b).
The estimated costs in these detailed cost estimate tables are based on the best available
information regarding the anticipated scope of the remedial alternative. 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. Changes may be documented in the form of a
memorandum in the Administrative Record file, an ESD, or a ROD amendment. This is an
order-of-magnitude engineering cost estimate that is expected to be within +50 to -30 percent of
the actual project cost, consistent with RI/FS guidance.
17 Costs for cleanup at mine and mill sites with potential human health exposures are included in the estimated costs
for the Selected Remedy for protection of the environment in the Upper Basin and Lower Basin.
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12.1.3 Expected Outcomes of Selected Remedy
This section describes the expected outcomes of the Selected Remedy in terms of cleanup levels
and residual risks, land uses, groundwater uses, and socio-economic and community impacts.
Cleanup Levels and Residual Risks
A tiered approach to lead soil remediation will be implemented. Soil with lead concentrations
between 700 mg/kg and 1,000 mg/kg will require a barrier, such as vegetation, to prevent
exposure and distribution of dust. Soil with lead concentrations above 1,000 mg/kg will require
partial removal and a soil barrier on residential yards and common use areas. The Selected
Remedy is expected to reduce the residual risk from lead in soil and house dust such that a
typical child has no more than a 5 percent probability of having a blood lead level above 10
[j,g/dL and no more than a 1 percent probability of having a blood lead level above 15 (j,g/dL.
The 100 mg/kg soil action level for arsenic, which is often co-located with lead, is expected to
result in a residual lifetime RME excess cancer risk for a residential exposure scenario that is
within EPA's target range of 10"6 to 10"4. In addition, soil removals in garden areas are expected
to reduce the residual risk from cadmium in homegrown vegetables such that the hazard quotient
is less than 1. As previously mentioned, this will be accomplished through the removal of lead-
contaminated soil, which is co-located with cadmium in garden soil.
The drinking water action levels are equal to the MCLs, as defined in Table 8.1-2.
Implementation of the Selected Remedy is expected to reduce exposures to metals in drinking
water such that the residual lifetime RME excess cancer risk for a residential exposure scenario
is within EPA's target range of 10"6 to 10"4 and the residual risk from cadmium is less than a
hazard quotient of 1.
Implementation of the Selected Remedy will allow residential land use. Commercial properties
that are remediated may be redeveloped for residential land use.
The remedy does not address risks associated with practicing subsistence lifestyles, therefore,
implementation of the Selected Remedy will not enable the practice of subsistence lifestyles in
those areas of the Upper Basin and Lower Basin. Institutional controls programs will be used to
limit exposures to contaminated fish and other aquatic food sources. The long-term goal is to
create areas that support the practice of subsistence lifestyles.
Land Uses
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Groundwater Uses
The remedy does not address potential future groundwater use. Additional available uses of
groundwater will not result from implementation of the Selected Remedy.
Socio-Economic and Community Impacts
Implementation of the Selected Remedy is expected to improve the socio-economic conditions of
the Coeur d'Alene Basin. Basin-wide sampling, analysis, and remediation of soil in residential
properties will provide property owners the information necessary for lead disclosures required
for property transactions. In addition, the increased protection of human health, focused on
children, may create the certainty needed for many families. Soil remediation of selected
recreational areas (picnic areas, beaches, and campgrounds) also will provide more certainty
about lead exposure and will enhance recreation by visitors and local users. Other aspects of the
remedy, such as establishing vegetative cover, remediating schoolyards, rights-of-way and
commercial property, and providing drainage improvements to protect the remedy, will be
coordinated with paint abatement programs and community redevelopment projects and should
make the communities a more attractive place to locate business. The work associated with
implementation of the Selected Remedy may provide additional jobs for the local labor force and
contractors, including local supply contractors. Additionally, remediation dollars spent in the
Silver Valley may create other opportunities for local businesses.
12.2 ENVIRONMENTAL PROTECTION IN THE UPPER BASIN AND LOWER
BASIN
The remedial actions selected for environmental protection in the Upper Basin and Lower Basin,
18
which are summarized in Table 12.2-1, will take approximately 30 years to implement. During
this period, EPA will evaluate the effectiveness and protectiveness of these remedial actions as
well as the technical practicability of attaining ARARs, in particular ambient water quality
standards for lead, zinc, and cadmium and compliance with the ESA and MBTA. During the
five-year review process and at the end of this approximately 30-year period, EPA will evaluate
and decide whether any additional remedial actions under CERCLA are necessary to attain
ARARs and to provide for the protection of human health and the environment, and whether any
ARAR waivers should be applied. Accordingly, consistent with 40 CFR 300.430(f)(l)(ii)(C),
the remedial action selected by this ROD for environmental protection in the Upper Basin and
Lower Basin is an interim measure and will become part of a final remedial action that will attain
ARARs, unless an ARAR waiver is invoked at that time.
18 The remedial actions described in this section include actions to protect human health at former mine and mill
sites in the Upper Basin.
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EPA expressly recognizes that after the selected remedial actions are implemented, conditions in
the Upper and Lower Basin may differ substantially from EPA's current forecast of those future
conditions, which is solely based on present knowledge. The tremendous amount of additional
knowledge that will be gained by the end of this period through long term monitoring and five-
year review processes may provide future bases for ARAR waivers. In addition, this new
information and advances in science and technology may allow for additional actions to achieve
ARARs and protect human health and the environment in a more cost-effective manner.
EPA recognizes that the State of Idaho has not concurred in the selection of any remedial action
beyond those selected in this ROD. Furthermore, after implementation of the remedies selected
by this ROD, EPA commits not to take or select any additional remedial actions in the Upper
Basin or Lower Basin without first consulting with the State of Idaho. EPA will also continue to
work with the regulatory stakeholder group, which was instrumental in developing the actions
selected in this ROD.19 Land management agencies may elect to implement cleanup actions on
properties within their management jurisdiction toward achieving the overall goals of the
Selected Remedy.
The Selected Remedy for environmental protection in the Upper Basin and Lower Basin consists
of priority cleanup actions that could be implemented within an approximately 30-year period
and would make significant progress toward protection of human health and the environment,
ARAR compliance, effectiveness, implementability, and cost effectiveness. This remedy was
also the Preferred Alternative in the Proposed Plan.
The priority actions included in the remedy were selected to achieve benchmarks, which are
near-term objectives that will serve as landmarks and measurements to evaluate the progress of
the remedy toward achievement of the long-term goals. The identification of benchmarks and
prioritization of actions were based on knowledge gained during the RI/FS process and extensive
discussions with stakeholders in meetings and weekly conference calls. Key areas of focus
included identification of benchmarks that would be achievable within the time period of the
Selected Remedy, appropriate measures of success, and actions necessary to achieve the
benchmarks. These discussions drew heavily on the large amount of environmental data
collected over time (e.g. water quality data and fish surveys) and the extensive experience of
stakeholders in the Basin. The benchmarks are shown in Table 12.2-1.
12.2.1 Description of the Selected Remedy
The Selected Remedy is a prioritization of the numerous actions needed for protection of human
health and the environment. As discussed in Section 7.2 of this ROD, the Coeur d'Alene Basin
19 The regulatory stakeholder group that participated in the development of the Selected Remedy included the states
of Idaho and Washington, the Coeur d'Alene and Spokane Tribes, U.S. Fish and Wildlife Service, U.S. Bureau of
Land Management, and U.S. Forest Service. The U.S. Geological Survey provided technical assistance.
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EcoRA evaluated data regarding the impacts of mining-related hazardous substances on the
environment. The EcoRA determined that sufficient information exists to demonstrate the
presence of high concentrations of metals in the soil, sediment, and surface water in the Basin.
These metals pose substantial risks to the animals and plants that inhabit the Basin. The results
of the EcoRA indicate that most Basin watersheds in which mining has occurred and a large
portion of the Basin down gradient of mining areas are ecologically degraded by mining-related
hazardous substances. This ecological degradation has manifested itself in observable effects in
the Basin plants and animals. Furthermore, if remediation is not conducted, the effects will
continue for the foreseeable future.
These demonstrated effects and future risks predicted in the EcoRA provide the basis for
identifying ecological remedial actions in the ROD. Given the extensive area of contamination,
EPA worked with Basin stakeholders to identify priority actions for protecting the environment.
Priority issues were grouped into three areas as an initial primary focus with respect to
environmental protection:
• Dissolved metals (particularly zinc and cadmium) in rivers and streams.
High concentrations of these metals have harmful effects on fish and other aquatic
receptors, as described in Section 7.2. Some native fish, including the cutthroat
trout, bull trout, and sculpin, are particularly sensitive to dissolved metals.
• Lead in floodplain soil and sediment. Existing lead contamination has harmful
effects on waterfowl and other ecological receptors, as described in Section 7.2.
• Particulate lead in the surface water.20 Lead transported downstream in the
river system is a continuing source of contamination for the Coeur d'Alene River,
Coeur d'Alene Lake, and the Spokane River. Lead transported in the river system
has impacted recreational areas in the Lower Basin and the Spokane River,
resulting in posted health advisory signs at beaches and swimming areas. During
flood events, lead transported by the river also impacts the wetlands and
floodplains. The potential exists for future particulate lead transport and
recontamination of recreation and feeding areas cleaned up as part of the Selected
Remedy.
These three priority issues represent the primary environmental problems in the Basin. The
prioritized actions of the Selected Remedy were identified based on their potential to achieve
benchmarks for reduction of environmental impacts related to these three priority issues. These
actions were incorporated into the selected remedies for Ninemile Creek, Canyon Creek, Pine
20Particulate lead is associated with sediment particles transported in surface water. Particulate lead is subject to
deposition in quiescent areas, whereas dissolved and colloidally-bound lead are not deposited in quiescent areas.
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Creek, the South Fork, and the lower Coeur d'Alene River, as well as associated riparian areas,
lateral lakes, wetlands, and agricultural areas in the Lower Basin.
Protection of riparian and riverine resources is an important environmental consideration in the
Basin. Based on the results of the risk assessment, toxic conditions exist for migratory birds,
other wildlife, and vegetation in the riparian and riverine corridor throughout the Basin. Actions
taken within the riparian and riverine zones will also be designed to increase protection of
receptors in these habitats. These actions will constitute an important step toward a fully
functional riparian and riverine corridor.
In addition to environmental protection, the actions described in the following sections would
have significant human health benefits, particularly for children who recreate in the Lower Basin
and individuals who would choose to practice a subsistence lifestyle. The potential exposure
pathways include ingestion or dermal contact with soil and sediment at beaches and other
common use areas; ingestion of native vegetables; ingestion of fish caught in Basin waters;
exposure to soil at waste piles; and ingestion of untreated surface water. The PHD has identified
children with elevated blood lead levels whose exposure was traced to use of beaches and
recreational areas in the Lower Basin.
Based on current estimates of remedy effectiveness, the Selected Remedy would be expected to
achieve about 50 to 70 percent of the dissolved metals load reduction in the Upper Basin (URS
2002a), measured in the South Fork at Pinehurst, that would be anticipated from full
implementation of Ecological Alternative 3 for about 19 percent of the estimated cost of
Ecological Alternative 3. Table 12.2-1 summarizes the Selected Remedy for environmental
protection in the Upper Basin and Lower Basin.
Dissolved Metals in Rivers and Streams
High levels of dissolved metals, particularly zinc and cadmium, exist in the river system in the
Basin. The Upper Basin is the primary source of dissolved metals. Dissolved metals
concentrations and impacts from mining currently prevent the river system from fully supporting
aquatic receptors, including native fish.
The widespread occurrence of tailings-impacted sediments will make it difficult to reduce
dissolved metals concentrations throughout the entire Basin to levels that comply with federal
and state water quality standards and fully support some sensitive native fish species. However,
further improvements to the ecosystem can begin in the short term through implementation of the
Selected Remedy and continue for many decades when remedial actions are combined with
natural recovery. Implementing the Selected Remedy will allow some localized portions of the
impacted areas to return to levels that would greatly improve the ecosystem.
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The benchmark of the Selected Remedy is reduction of dissolved metals to concentrations that
allow substantial improvement to the fisheries and the ecosystem of the South Fork and some of
its tributaries. Fish and aquatic organisms that are more tolerant of metals than native fish could
return more quickly. The population and species diversity of fish and aquatic organisms are
expected to continue to improve as cleanup progresses in the Basin. To the degree practical, as
actions affecting surface water quality are implemented, adjacent riparian and riverine areas
would be addressed in order to protect species that inhabit these areas. Re-establishment of fish
populations using stocking is not anticipated.
As part of the development of the fisheries benchmarks, EPA and others examined fisheries
conditions throughout the Coeur d'Alene River Basin (USEPA 2001d). The fisheries conditions
were grouped into tiers based on fish populations, types of species present, and other factors.
The tiers range from Tier 0 (no fish present) to Tier 5 (fully-functional native fishery, including
the presence of sensitive species). Water chemistry and habitat conditions associated with each
tier were compiled based on observed conditions in the Basin. The fishery tier definitions are
provided in Table 12.2-1. These water chemistry and habitat conditions are based on the current
understanding of the conditions consistent with the fisheries tiers. As fishery conditions are
monitored during and after cleanup, the benchmark chemistry and habitat conditions may need to
be modified.
EPA coupled the data characterizing existing water quality conditions and fish populations with
a probabilistic model that examined anticipated outcomes of conducting varying amounts of the
response actions comprising Alternative 3. Through this means, EPA was able to prioritize
cleanup areas for the Selected Remedy and estimate outcomes in terms of anticipated water
quality conditions and consequent fish populations. Priority areas for the Selected Remedy have
been identified based upon where the most load reduction can be practically achieved and where
the best opportunities exist for re-establishing a sustainable trout fishery, with an emphasis on
native fish. Implementation of the Selected Remedy will result in progress toward compliance
with state and federal water quality standards and criteria. An example of this analysis is
provided in the subsequent description of the Selected Remedy for Ninemile Creek.
Table 12.2-1 identifies the benchmarks and summarizes the remedial actions for Upper Basin
areas, including Canyon Creek, Ninemile Creek, Pine Creek, and the South Fork. Ninemile
Creek and Pine Creek are initial priority areas for fisheries improvements. The discharge from
Canyon Creek is a priority for reducing metals loads to the South Fork.
Table 12.2-2 summarizes the fisheries benchmarks, the water chemistry and physical conditions
that exist currently, and those that would be needed to achieve the fisheries benchmarks. The
Selected Remedy includes those actions that, based on existing information, would be needed to
achieve the fisheries benchmarks. These actions were used to develop the estimated costs
presented in Section 12.2.2. As the remedy is implemented and monitored, the cleanup actions
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ultimately taken could differ, based on the additional knowledge gained, from those currently
identified.
Ninemile Creek. Ninemile Creek was identified as a focus of the Selected Remedy for the
following reasons:
• Ninemile Creek is essentially devoid of fish in the area of mining impacts
• Habitat conditions for aquatic receptors and other animals are good compared to
other highly-impacted areas, such as Canyon Creek
• Water quality impacts largely stem from a few large sources in unpopulated areas
of the East Fork
• The Selected Remedy could build upon removal actions already completed or
underway
• The experience gained in Ninemile Creek could be applied to other highly-
impacted drainages, such as Canyon Creek
The description of the Selected Remedy for Ninemile Creek is organized by three stream
reaches. These are:
• East Fork above the Success mine site
• East Fork from Success to its confluence with the mainstem
• Mainstem Ninemile Creek
Areas identified for cleanup during implementation of the Selected Remedy are shown in
Figure 12.2-1.
East Fork Above the Success Mine Site. The benchmark for this reach is to improve conditions
to allow natural re-establishment of a salmonid fishery, with an emphasis on native species
(Tier 3 fishery). The fishery would not necessarily include the presence of metals-sensitive
species (such as the bull trout), reproduction, or the presence of juveniles. It is estimated that a
reduction of metals loads of greater than 80 percent will be needed to achieve dissolved metals
concentrations of less than 7 times the zinc chronic AWQC, which is the target concentration
range for a Tier 3 fishery.
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In addition to reductions in metals concentrations in the creek water, the cleanup would be
designed to mitigate mining impacts on the riverine and riparian zone to protect fish, migratory
birds, and other animals. An additional 1.7 miles of low-risk riverine and riparian area would be
gained from the cleanup.
Initial actions in the East Fork of Ninemile Creek will include cleanup of dissolved metals
sources in the reach from the headwaters area to the Success mine site. The source areas within
the East Fork drainage identified for cleanup are shown in Figure 12.2-2. This cleanup has been
initiated through removal actions by the mining companies and the State of Idaho at the Success
and the Interstate Mill Site, as well as the planned cleanup actions at the Rex Mine and Mill site.
Surface water monitoring data show that, historically, the Interstate and Success sites are the
largest sources of metals loads to Ninemile Creek. Specific performance goals for the removal
actions at these source areas have not been established. As part of the Selected Remedy,
performance goals will be established based on the benchmarks for this reach. Should the
performance goals not be achieved as a result of the removal actions, additional actions will be
undertaken as part of the Selected Remedy. Initial monitoring results for the Interstate and
Success sites are presented in Harvey (undated) and Golder Associates (2001), respectively.
East Fork from Success to Its Confluence with the Mainstem. Because current metals
concentrations are higher in this reach, it is not anticipated that re-establishment of a resident
fishery would occur as a result of implementation of the Selected Remedy. The benchmark for
this reach is to improve conditions to enable migration of fish between the upstream reaches and
the mainstem (Tier 1 fishery).
The State of Idaho is conducting a removal action at the Success site that consists of groundwater
collection and treatment and surface water run-on controls. Depending on how successful the
removal action is, additional actions in this reach could include scale-up to full-scale treatment at
the Success site, relocation of the Success tailings pile, or construction of a treatment pond to
remove metals from the creek water. The Selected Remedy would include monitoring of the
removal action to ensure the actions are consistent with the benchmarks established for the
Selected Remedy.
The treatment pond, if needed to achieve the benchmarks for the mainstem of Ninemile Creek,
would treat creek water collected from the East Fork upstream of its confluence with the
mainstem. The location of the treatment pond and its design capacity would be selected during
remedial design, dependent on the results of treatability testing and siting considerations.
Conceptually, the treatment pond would be very similar to the treatment pond identified for
Canyon Creek. The treatment pond is described in further detail in the subsequent section that
describes the Selected Remedy for Canyon Creek. It is anticipated that initial design studies
would be implemented in Canyon Creek, and the experience gained would be applied in
Ninemile Creek, if surface water treatment is needed. Preliminary estimates indicate a treatment
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pond with a design capacity of 10 cubic feet per second could remove 60 to 70 percent of the
annual load of zinc that discharges from the East Fork into the mainstem of Ninemile Creek.
The load reductions and estimated costs for the treatment pond are based on the assumption that
all remedial actions in the East Fork have been implemented.
Mainstem Ninemile Creek. The benchmark for this reach is to improve conditions to enable
migration of fish between the South Fork of the Coeur d'Alene River and the East Fork of
Ninemile Creek (Tier 1 fishery). The Selected Remedy does not include cleanup actions within
this reach to improve water quality. Improvements in water quality would result from cleanup
actions implemented in the East Fork. At the mouth of Ninemile Creek, a culvert currently
impedes fish passage. This would also need to be addressed, but is not included in the Selected
Remedy.
The actions implemented in the Ninemile Creek watershed during the Selected Remedy would
also include measures to address protection of human health at the Day Rock mine and mill site.
The potential exists that some or all of the site may be preserved for its historical value. Any
remedial design/action would be conducted in accordance with the National Historic
Preservation Act (NHPA), 16 U.S.C. § 470f, 36 CFR Parts 60, 63, and 800 as described in
Section 13.
EPA used a probabilistic analysis that predicted water quality conditions that would result from
conducting varying amounts of the response actions comprising Alternative 3 to establish
fisheries benchmarks and evaluate the scope of cleanup needed to achieve the benchmarks. An
example of this analysis for the mainstem of Ninemile Creek follows.
Figure 12.2-3 illustrates the use of the probabilistic analysis to predict the probability of
achieving the water quality conditions (expressed as multiples of the zinc AWQC) consistent
with various fisheries tiers as a function of the cleanup effectiveness. Under complete
implementation of Alternative 3, the probabilistic analysis predicted less than a 25 percent
probability of achieving water quality conditions consistent with a Tier 3 fishery (less than 7
times the chronic AWQC) for the mainstem of Ninemile Creek. Further, the analysis predicted
approximately a 50 percent probability of achieving water quality conditions consistent with a
Tier 2 fishery (less than 10 times the chronic AWQC), and greater than a 90 percent probability
of achieving water quality conditions consistent with a Tier 1 fishery (less than 20 times the
acute AWQC) under Alternative 3.21
21 For a Tier 1 fishery (migratory corridor), the water quality benchmark is based on the acute AWQC because the
fish would be present in the stream reach for only a limited time.
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EPA and stakeholders recognized several tradeoffs associated with complete implementation of
Alternative 3 in Ninemile Creek.
• High concentrations of metals in the reach of the East Fork from Success
downstream to the confluence of the East Fork and the mainstem would limit re-
establishment of a resident fishery throughout Ninemile Creek.
• There would be concerns with the implementability of Alternative 3 in the
mainstem due to the presence of private development.
• Significant short-term impacts would be associated with complete implementation
of Alternative 3.
• The estimated present worth cost of complete implementation of Alternative 3 in
Ninemile Creek is $59 million. The additional actions for full implementation of
Alternative 3 were considered less effective than actions to reduce dissolved
metals from other impacted tributaries, e.g., Canyon Creek.
Because of these tradeoffs, EPA and stakeholders elected to establish a benchmark for the
mainstem of achieving a migratory corridor for fish from the South Fork to the East Fork of
Ninemile Creek. The probabilistic analysis was used to evaluate the scope of Alternative 3
response actions needed to achieve the benchmark, as follows.
For complete implementation of Alternative 3 above Success together with the removal actions
at the Success, Interstate, and Rex sites, the probabilistic analysis predicted a 35 percent
probability of achieving water quality conditions consistent with a Tier 1 fishery (20 times the
acute AWQC) in the mainstem as a result of implementation of the Selected Remedy, as shown
in Figure 12.2-3. There is evidence for fish migration at concentrations greater than 20 times
AWQC, and the Selected Remedy may achieve the benchmark despite an estimated probability
of achieving less than 20 times the acute AWQC that is less than 50 percent. However, should
monitoring indicate the benchmark would not be achieved, the Selected Remedy includes a
contingency for construction of a treatment pond to treat the discharge from the East Fork, in
addition to the cleanup actions described above. For an estimated average removal of 69 percent
of the dissolved metals load in the East Fork by the treatment pond, the estimated probability of
achieving water quality conditions consistent with a Tier 1 fishery would increase to
approximately 80 percent.
Figure 12.2-4 depicts the anticipated results of the Selected Remedy in Ninemile Creek
compared to Alternative 3. This figure indicates the Selected Remedy will remove
approximately 84 percent of the dissolved metal load, remediate approximately 62 percent of the
volume of contaminated material, take up 87 percent of the regional repository requirements, and
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represent 61 percent of the cost relative to full implementation of Alternative 3. These
percentages were calculated assuming all actions contemplated under the Selected Remedy,
including additional actions at the Interstate, Rex, and Success sites and construction of a
treatment pond near the confluence of the East Fork and the mainstem, will need to be
implemented to achieve the water quality benchmarks.
The long-term goals for Ninemile Creek include the return of a fully-functional native fishery
and full protection of riparian and riverine zone birds and other animals. EPA believes that
additional cleanup actions on the mainstem and an extended period of natural recovery would be
needed to achieve the long-term goals in Ninemile Creek.
Pine Creek. Considerable cleanup work has already been conducted in the Pine Creek
watershed, particularly by the BLM. Pine Creek currently supports an adult fishery, including
brook trout and a smaller population of native cutthroat trout. However, populations and
reproduction in some reaches of the creek are limited, primarily by stream structure and riparian
zone conditions that have been degraded by mining impacts, with metals concentrations being a
secondary limiting factor. The benchmark for Pine Creek is to improve conditions to allow
natural increases in salmonid populations, with an emphasis on native fish, and to improve
conditions to allow for spawning and rearing.
Areas identified for cleanup during the Selected Remedy are shown in Figure 12.2-5. The
actions implemented in the Pine Creek watershed would build on the work already conducted by
the BLM. Actions would include bank and bed stabilization and riparian zone revegetation to
mitigate the effects of mining impacts. The actions would also include hot spot removals within
the stream and at former mine and mill sites, including the Upper and Lower Constitution,
Highland-Surprise, Nevada-Stewart, Hilarity, Little Pittsburg, Sidney (Denver Creek), and
Nabob. Several of these sites (Upper and Lower Constitution, Highland Surprise, Nevada-
Stewart, Hilarity, and Nabob) are also a concern for protection of recreational users. As with
work in Ninemile Creek, lessons learned while implementing the Selected Remedy in Pine Creek
can be applied to other areas in the Basin requiring additional cleanup.
During the development of the priority actions included in the Selected Remedy for Pine Creek,
EPA, in consultation with stakeholders, evaluated other potential response actions anticipated in
Alternative 3 in light of what they would accomplish over an approximately 30-year time period.
Dissolved metals concentrations in Pine Creek are currently generally much lower than in
Ninemile Creek and Canyon Creek, and it was concluded that the cleanup of sites that are
smaller sources of metals discharges than those included in the Selected Remedy would not be
necessary at this time to achieve the benchmarks of increasing salmonid populations and
improving spawning and rearing conditions.
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Conversely, it was concluded that a lower level of cleanup would be ineffective in reducing
metals concentrations from current conditions (10 to 20 times the AWQC in the East Fork of
Pine Creek) to conditions needed to achieve the fisheries benchmarks (less than 7 times the
chronic AWQC to support a salmonid fishery). Mitigation of mining impacts would be needed
to provide stream structure and riparian zone conditions supportive of the benchmarks for
fisheries improvements, as well as to provide protection of riparian zone animals. A lower level
of cleanup would also not be protective of recreational users at former mine and mill sites.
Figure 12.2-6 depicts the anticipated results of the Selected Remedy in Pine Creek compared to
Alternative 3. This figure indicates the Selected Remedy will remove approximately 29 percent
of the dissolved metal load, remediate approximately 26 percent of the volume of contaminated
material, take up less than 1 percent of the regional repository requirements, and represent 32
percent of the cost relative to full implementation of Alternative 3.
The long-term goals for Pine Creek include the return of a native fishery and full protection of
riparian and riverine zone birds and other animals. EPA believes that additional cleanup actions
and a period of natural recovery would be needed to achieve the long-term goals in Pine Creek.
Canyon Creek. Canyon Creek is essentially devoid of fish below Burke as a result of high
metals concentrations and severely degraded riverine and riparian conditions. Canyon Creek
contributes more dissolved metals load to the South Fork than any other tributary, approximately
20 to 25 percent of the load in the South Fork at its confluence with the North Fork. The
benchmark for Canyon Creek is to reduce dissolved metals loads discharging from the creek into
the South Fork by at least 50 percent.
Implementation of a source-by-source cleanup in Canyon Creek, as is anticipated under
Alternative 3, would be very difficult, costly, and time consuming. The Selected Remedy for
approximately 30 years of work in Canyon Creek will focus on identifying cost-effective
technologies for improving downstream water quality in the South Fork and mainstem Coeur
d'Alene River and, ultimately, in Coeur d'Alene Lake and the Spokane River.
One potentially cost-effective approach that will be evaluated is to intercept the creek water in
lower Canyon Creek and remove metals using passive treatment. Under this approach, the
individual metals sources in the Canyon Creek watershed would not be addressed during the
Selected Remedy. Should creek water treatment prove effective after pilot studies, full-scale
treatment would be implemented as part of the Selected Remedy in Canyon Creek. The
development of innovative and potentially cost-effective water treatment in Canyon Creek would
be effective in achieving desired reductions and potentially have application in other parts of the
Basin (e.g., Ninemile Creek). If passive treatment does not prove effective, alternative treatment
and control systems to achieve the benchmark of at least 50 percent reduction of dissolved
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metals loads would be evaluated. Alternative actions may be used based on an evaluation
against CERCLA remedy selection criteria.
Because this approach is not anticipated to achieve the long-term goal of ecosystem recovery
within Canyon Creek, EPA believes additional work would be necessary in Canyon Creek.
Source control efforts conducted elsewhere in the Basin (e.g., Success and Interstate in Ninemile
Creek) will be monitored and evaluated such that subsequent efforts in Canyon Creek can be
performed in a cost-effective manner.
A conceptual drawing of a passive treatment system using a treatment pond is depicted in Figure
12.2-7 (USEPA 2001g). Creek water would be diverted into the treatment pond at flow rates up
to the treatment design capacity. At higher flows, the creek flow above the design capacity
would be bypassed without treatment. The diverted water would percolate through a bed of
reactive media, which would remove metals from the water. The treated water would be
discharged back into the creek.
Because groundwater containing relatively high concentrations of metals discharges to surface
water throughout the reach downstream of the Hecla-Star tailings ponds, a diversion location as
far downstream as is feasible would maximize removal of metals. The location of the treatment
pond and its design capacity would be selected during remedial design, dependent on the results
of treatability testing and siting considerations. A possible location of the treatment pond is
shown in Figure 12.2-8.
The expected value of the dissolved zinc load in Canyon Creek after remedy implementation is
estimated to be 234 pounds per day, a reduction of 322 pounds per day compared to the expected
value calculated from surface water data collected from 1991 to 1999. The expected value is
based on a probabilistic analysis of potential treatment pond performance and considers potential
load reductions from removal actions conducted by SVNRT and stabilization of sediment
sources that will be conducted as part of the Selected Remedy. The analysis of potential
treatment pond performance is based on an assumed design capacity of 60 cfs. The sediment
stabilization measures are described later in this section.
The Hecla-Star Tailings Ponds in lower Canyon Creek are a potentially significant source of
dissolved metals to groundwater and surface water. The nature and extent of metals loading
from the tailings ponds may affect placement and sizing of the treatment pond, and additional
characterization of the loading may be conducted during design and siting studies for the
treatment pond.
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Disposal of treatment residuals (spent media and collected sediment) will be evaluated during
remedial design. For the purpose of estimating costs, it was assumed the residuals will be
disposed of in a solid waste repository. Regeneration of spent media is an option that will be
evaluated during remedial design.
Selected remedies in Canyon Creek also include stabilization of dumps and stream banks that are
sources of sediment and particulate metals in the creek, the South Fork, and the lower Coeur
d'Alene River. The locations identified for stabilization are Tamarack, Omaha, Standard-
Mammoth Loading Area, Standard-Mammoth mill, Hercules No. 5, Oom Paul, Ajax No. 3,
Hecla (Burke), Tiger-Poorman, West Star, Gertie, and Gorge Gulch. The locations of these
sources areas are shown in Figure 12.2-9.
The actions implemented in the Canyon Creek watershed during the Selected Remedy would
also include protection of human health at two former mine and mill sites where potential
exposures were identified (Standard-Mammoth mill and Sisters mine). Areas identified for
cleanup in the Selected Remedy are shown in Figure 12.2-9.
Additional actions may also be needed at the Burke concentrator. This site is currently fenced to
limit access. The potential exists that some or all of the site may be preserved for its historical
value. Should people be allowed on the site as a result of the historical preservation, or should
access otherwise become available, cleanup actions would be needed to limit exposures to
metals. The location of the Burke concentrator is shown in Figure 12.2-9.
During the development of the priority actions included in the Selected Remedy for Canyon
Creek, EPA, in consultation with stakeholders, evaluated other potential response actions
anticipated in Alternative 3 in light of what they would accomplish over an approximately 30-
year time period. Canyon Creek is the source of 20 to 25 percent of the dissolved metals load in
the South Fork, and a relatively large reduction of metals load from Canyon Creek would be
needed to meet the benchmark for improvements in the South Fork fish migration corridor, as
well as to meet benchmarks for reductions in dissolved metals concentrations in the Spokane
River. A source-by-source cleanup in Canyon Creek was considered; however, this approach
would require extensive removals and thus be difficult to implement within the 30-year
timeframe of the Selected Remedy. The effectiveness of this approach would be uncertain, and
the cost would be high.
Not controlling the metals loading from Canyon Creek was also considered. Not controlling the
metals loading from Canyon Creek would result in continued significant and unacceptable metals
discharges to downstream waters and would not contribute to achieving the benchmark of
improving the fisheries and ecosystem of the South Fork or reducing dissolved metals
concentrations in the Spokane River.
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Figure 12.2-10 depicts the anticipated results of the Selected Remedy in Canyon Creek compared
to Alternative 3. This figure indicates the Selected Remedy will remove approximately 73
percent of the dissolved metal load, take up approximately 13 percent of the regional repository
requirements, and represent 23 percent of the cost relative to full implementation of
Alternative 3. The low percentage of regional repository space required reflects the Selected
Remedy's focus on reducing metal loading to the South Fork, not Canyon Creek.
The long-term goals for Canyon Creek include the return of a native fishery and full protection
of riparian and riverine zone birds and other animals. EPA believes that additional cleanup
actions and an extended period of natural recovery would be needed to achieve the long-term
goals for Canyon Creek.
South Fork. The fisheries benchmark for the South Fork22 is to improve conditions to support a
higher fish density (Tier 2+ to 3 fishery). Improvements in conditions would result largely from
implementation of the selected remedies for Canyon Creek, Ninemile Creek, and Pine Creek. In
the floodplain of the South Fork (in areas outside of the Bunker Hill Box), tailings "hot spots"
would be excavated and disposed of. Under separate regulatory authorities, BLM is also
evaluating the need for excavation and/or capping of BLM-owned lands in this area. These
activities would be consistent with the overall goal of protection of human health and the
environment. Streamside actions would include stabilization and bioengineering of the stream
channel and banks. These actions would enhance the South Fork as a migratory corridor for fish
by increasing the amount of pools and shade and would provide initial protection of animals that
inhabit the riparian zone. Locations of tailings hot spots are shown in Figure 12.2-11.
The remedy in the South Fork watershed would also include cleanup at six sites that have been
selected because of potential human health exposures, but also have ecological impacts:
• National Millsite
• Morning No. 6 Mine and Millsite
• Golconda
• Hercules Millsite in Wallace
• U.S. Bureau of Mines Impoundment
• Silver Dollar Mine
The locations of the National, Morning, and Golconda sites are shown in Figure 12.2-12. The
locations of the Hercules, U.S. Bureau of Mines, and Silver Dollar sites are shown in Figure
12.2-11.
22 For the purposes of describing the Selected Remedy, this area includes the South Fork from its headwaters to its
confluence with the North Fork and all tributaries except Canyon Creek, Ninemile Creek, Pine Creek, and tributaries
within the Bunker Hill Box.
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During the development of the priority actions included in the Selected Remedy for the South
Fork, EPA, in consultation with stakeholders, evaluated other potential response actions
anticipated in Alternative 3 in light of what they would accomplish over an approximately 30-
year time period. Sediments and associated groundwater are the primary sources of dissolved
metals originating from the South Fork floodplain. More extensive metals reductions would
involve additional removal or containment of sediments (with or without treatment of associated
groundwater). The additional removal or containment and treatment actions would involve
sediments that are generally lesser sources of metals or more difficult to access due to the depth
of the sediment or their location beneath infrastructure or private property. It was concluded that
these additional actions would contribute less to achieving the benchmark of improving the
South Fork as a fish migration corridor, would be less implementable, and would be more costly
compared to the "hot spot" removal actions included in the Selected Remedy.
Conversely, removal of the remaining accessible floodplain hot spots, as is planned during the
Selected Remedy, would be readily implementable and cost-effective for reducing dissolved
metals load and increasing protection of humans and other animals that use these areas. A lower
level of cleanup than is proposed for the Selected Remedy would also not be protective of
humans potentially exposed to metals at the seven former mine and mill sites identified for
cleanup.
As with Ninemile, Canyon, and Pine Creeks, lessons learned while implementing the Selected
Remedy in the South Fork can be applied to other areas in the Basin requiring cleanup.
Figure 12.2-13 depicts the anticipated results of the Selected Remedy in the South Fork
compared to Alternative 3. This figure indicates the Selected Remedy will remove
approximately 7 percent of the dissolved metal load, remediate approximately 6 percent of the
volume of contaminated material, take up 2 percent of the regional repository requirements, and
represent 5 percent of the cost relative to full implementation of Alternative 3. The low
percentages reflect that cleanup in the tributaries is more cost effective than cleanup in the South
Fork at this time.
The long-term goals for the South Fork include the return of a native fishery and full protection
of riparian- and riverine-zone birds and other animals. EPA believes that additional cleanup
actions and an extended period of natural recovery would be needed to achieve the long-term
goals for the South Fork.
Other Upper Basin Areas. Improvements in water quality in the river system will be strongly
dependent on reductions in metals loading achieved in areas along the South Fork, including the
Bunker Hill Box. Approximately one-half of the dissolved metals load in the South Fork above
the North Fork confluence comes from the river reach that includes the Bunker Hill Box.
Actions taken to date within the Bunker Hill Box are expected to result in improvements in water
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quality; however, it is anticipated that additional actions will be needed to meet cleanup goals.
These additional actions would likely include control of metals loading from groundwater to
surface water, including the reach adjacent to the CIA. As described in Section 4.1.2,
implementation of Phase II of the Non-Populated Areas ROD will address site surface water and
groundwater cleanup. EPA anticipates surface water and groundwater cleanup actions to be
implemented through future RODs, amendments to RODs, or ESDs for the Bunker Hill Box and
to parallel implementation of the Selected Remedy.
Lead in Floodplains Soil and Sediment
Soil and sediment throughout the floodplains of the lower Coeur d'Alene River Basin are
contaminated with lead that has washed downstream over the years from Upper Basin mining
activities. Sediments are also remobilized and transported into Coeur d'Alene Lake and the
Spokane River. Lead-contaminated sediments in the floodplains (including wetlands, bottom
sediment of the lateral lakes, and low-lying upland areas) have caused adverse effects to wildlife.
Notably, waterfowl (e.g., tundra swan and ducks) ingest highly contaminated sediment to the
extent that many have suffered toxic effects or died from ingestion of lead. The USFWS has
documented numerous deaths among waterfowl and small mammals in the South Fork and
Coeur d'Alene River floodplain.
A long-term goal is to reduce metals exposure of plants, wildlife, and fish throughout these areas
to levels that are protective of the ecosystem. Because the total contaminated floodplain area in
the Lower Basin is so large, it is important to prioritize areas to improve specific, priority areas
within the ecosystem. For example, one benchmark is to reduce waterfowl mortality by
providing additional safe feeding areas. Site-specific data from waterfowl feeding studies
indicate a lead cleanup level of 530 mg/kg in sediment for protection of waterfowl.
It was recognized that all areas needing long-term cleanup could not be addressed effectively in
the Selected Remedy. Resource agencies have identified high-priority areas in the Lower Basin
based on potential for contributing to lead poisoning of wildlife, high use by waterfowl, high
levels of lead in sediments, availability of site access, and relatively low potential for
recontamination during flood events. The areas identified as top priorities are:23
• Thompson Lake (300 acres of wetland area and 256 acres of lake area)
• Thompson Marsh (59 acres of wetland area and 122 acres of lake area)
• Bare Marsh (165 acres of wetland area)
23 The acres of lake area shown are the entire areas of the lakes. To develop estimated costs, it is anticipated
contaminated sediments will be cleaned up to a water depth of six feet (which represents an average of
approximately 25% of the total lake area). These water depths represent the highest use feeding areas and,
consequently, the areas of greatest exposure to waterfowl and other animals.
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• Medicine Lake (198 acres of wetland area and 230 acres of lake area)
• Lane Marsh (213 acres of wetland area)
• Cave Lake (190 acres of wetland area and 746 acres of lake area)
• Anderson Lake (44 acres of wetland area and 505 acres of lake area)
The areas identified for cleanup during the Selected Remedy are shown in Figure 12.2-14. An
additional goal of the Selected Remedy is to increase the amount of safe feeding areas by
identifying and cleaning up some areas that are currently used for agriculture. These actions
would be taken in cooperation with the current owners. It is estimated an additional 1,500
agricultural acres may be cleaned up. In total, about 4,500 acres of safe waterfowl feeding areas
could be provided by the cleanup actions taken under the Selected Remedy.
A combination approach is envisioned for these areas, depending on the specific conditions (e.g.,
depth of contaminated sediments) within a given wetland or lake. Contaminated materials would
be excavated from some areas and transported to an upland repository or consolidated within the
lateral lake being cleaned up. Other areas would be capped with a layer of clean soil to prevent
feeding birds from becoming exposed to metals. Excavation depths and cap thicknesses will be
selected to prevent direct exposure of waterfowl, fish, and other animals to contaminated
sediments. Excavation depths and cap thicknesses are anticipated to average approximately one
foot. If feasible, capping materials could be obtained from clean subsurface sources within the
wetland unit, with the possible result of creating deeper ponded areas to increase feeding
opportunities for waterfowl and fish. Soil treatment to reduce lead bioavailability may be
applied in selected areas if effective treatment technologies are identified in pilot tests underway
at this time.
The Selected Remedy focuses on cleaning up sediments in the portions of the lateral lakes where
the water depth is six feet or less. These water depths represent the highest use feeding areas
and, consequently, the areas of greatest exposure to waterfowl and other animals. Monitoring of
the effects of the cleanup would include measuring the concentrations of lead in brown bullhead
fish. The brown bullhead has been identified by the USFWS as the best indicator species for the
ecological health of the lakes. Should lead concentrations in the brown bullhead remain elevated
following completion of cleanup and waterfowl mortalities continue, the need for additional
actions would be evaluated. Monitoring of blood lead concentrations in floodplain animals such
as migratory birds is also a primary biomonitoring tool that may be used in evaluating cleanup
activities.
Although the areas identified for cleanup during the Selected Remedy have relatively low
recontamination potential, some recontamination potential does exist. Hydraulic controls
(floodgates) and levees could be used to limit recontamination of treated areas. These structures
could have effects on the overall hydrology of the river/floodplain system. The need for these
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types of structures and their effect on the hydrology of the river/floodplain system would be
evaluated during remedial design.
During the development of the priority actions included in the Selected Remedy for mitigation of
the impacts of lead in floodplain areas, EPA, in consultation with stakeholders, evaluated other
potential response actions anticipated in Alternative 3 in light of what they would accomplish
over an approximately 30-year time period. Cleanup at additional areas was evaluated,
including:
• Harrison Slough
• Blue Lake
• Black Lake
• Swan Lake
• Blessing Slough
• Moffit Slough
• Hidden Marsh
• Campbell Marsh
• Killarney Lake
• Strobl Marsh
• Lane Marsh (only partially addressed in the Selected Remedy)
• Black Rock Slough
• Bull Run
• Porter Slough
• Rose Lake
• Orling Slough
• Cataldo Slough
• Mission Slough
Although cleanup of these wetlands may be needed to protect migratory birds under the MBTA,
they were not included in the Selected Remedy because of higher recontamination potential and
poorer access. The scope of actions that could be implemented in the approximately 30-year
response timeframe was also limited by the need to further develop and verify effective,
implementable methods of reducing lead exposure and recontamination. The use of management
techniques to discourage waterfowl feeding at contaminated areas also was also considered.
These techniques were not included in the Selected Remedy because of concerns about reliability
and the limited extent of alternative uncontaminated feeding areas for waterfowl.
The Selected Remedy includes remediation of 4,528 acres of wetland and lateral lakes in the
lower basin. Studies conducted during the remedial investigation indicate that over 18,000 acres
of waterfowl habitat exceed adverse effect levels and over 15,000 acres exceed lethal thresholds.
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Over 13,000 acres that exceed the adverse effect levels are not targeted for cleanup in the
Selected Remedy.
The scope of cleanup included in the Selected Remedy reflects a reasonable amount of
implementable work, for an approximately 30-year timeframe, toward achieving protection of
waterfowl and other animals, as well as a first step toward protection of birds covered under the
MBTA. The work will be sequenced to ensure that current land uses (e.g., recreational) will be
available throughout the period of cleanup.
It is expected that sediments deposited in these wetlands during future floods would generally
decrease in metals content over time as a result of cleanup of the Upper Basin, the river banks of
the mainstem Coeur d'Alene River, and, to a lesser extent, the bed of the river. If the metals
content of sediments decreases with time, recontamination would be less important for these
future wetlands cleanup efforts.
An important goal is full return of cultural resources and recreational uses in the Basin.
Remedies that address wetland risks to waterfowl would also address potential human exposures
at water potato grounds and recreational beaches. Institutional controls, such as warning
signage, will remain in place in the Lower Basin until they are no longer needed to protect
human health, but are not preferred as the long-term solution.
Particulate Lead in Surface Water
Lead-bearing sediment in surface water is transported downstream to Coeur d'Alene Lake and
the Spokane River, and washes across and contaminates the floodplain in the Lower Basin
during flood events. Three sources are suspected to contribute the major particulate lead load in
the Lower Basin: sediments derived from the Upper Basin, contaminated river bank sediments in
the Lower Basin, and river bed sediments in the Lower Basin. The banks in many areas of the
Lower Basin are steep and actively eroding into the river. River bed sediments have become
contaminated from materials transported from upstream and from the eroding river banks. A
portion of this sediment is entrained during high flow events, transported downstream in the
river, and deposited over the floodplain.
One goal of the Selected Remedy is to reduce the lead load in sediment transported and
deposited in downstream areas of the lateral lakes, Coeur d'Alene Lake, and Spokane River.
Reduction of lead-bearing sediment in surface water is necessary to minimize recontamination of
cleaned areas, prevent the occasional exceedances of drinking water standards in Coeur d'Alene
Lake, protect wildlife from exposure, and reduce lead concentrations and AWQC exceedances in
the Spokane River. During high flow in 1999, the dissolved lead concentration at the outlet from
Coeur d'Alene Lake exceeded the chronic AWQC for lead by a factor of approximately two
(USEPA 2001b, Table 5.7-8), which suggests a reduction in load of at least 50 percent may be
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needed during high-flow events to reduce year-round dissolved lead concentrations to below the
chronic AWQC in the Spokane River.
Initially during implementation of the Selected Remedy, cleanup actions would focus on areas
with the most actively eroding river banks. The reaches for bank stabilization will be prioritized
based on the degree of erosion occurring and the concentrations of metals in the riverbank
sediments. Remedial actions would include a combination of bioengineering and removals, as
appropriate, to allow re-establishment of a sustainable river ecosystem. The extent of removal of
contaminated material would be determined by the concentrations of metals in the river bank
material, the likelihood that stabilized banks will remain stable in the future, site accessibility,
and the presence of infrastructure. A total of about 33 miles of river banks24 that are highly
susceptible to erosion are targeted for stabilization during the Selected Remedy. In addition to
reducing particulate lead loading to the river, these actions would increase the area of low-risk
riparian area adjacent to the river in these reaches. Potential redeposition of metal-enriched
sediment onto remediated river banks after high-flow events would be evaluated as part of the
remedial actions.
Cost-effective methods for river-bed sediment removal will also be evaluated and conducted
during the Selected Remedy. The natural depositional areas around Dudley and the Cataldo
Mission have been identified as the potential sites for sediment removal or management
operations. The Dudley area is the location of relatively thick deposits of sediment containing
high concentrations of lead and other metals. Fine-grained sediment from the South Fork and
North Fork accumulates at this location. Upstream of the Dudley area, the area around the
Cataldo Mission acts as a natural trap for coarser-grained sediment, which usually contains less
lead, from the North and South Forks. Other sediment management techniques that may be
viable alternatives to sediment removals for reducing particulate lead transport and providing
long-term protection will also be evaluated during remedial design.
Sediments naturally accumulate in areas where the river leaves its bank during flood events.
During implementation of the Selected Remedy, the feasibility of engineering these areas
(referred to as "splays") as natural traps for sediment transported during flood events would be
evaluated through pilot studies.
Monitoring and evaluation of the potential improvements resulting from pilot-scale and full-scale
remedial actions during the Selected Remedy will be used to help guide the continuing and
future implementation of cost-effective remedies for the Lower Basin.
24 Measured as length of bank on one side of the river, not as river miles.
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During the development of the priority actions included in the Selected Remedy for particulate
lead in surface water, EPA, in consultation with stakeholders, evaluated other potential response
actions anticipated in Alternative 3 in light of what they would accomplish over an
approximately 30-year time period. Additional removal or stabilization actions, including banks
less susceptible to erosion, was evaluated, but was considered to provide less overall protection
of the environment compared to removal or stabilization of banks with high erosion
susceptibility. More extensive removal of river-bed sediment was also evaluated, but was not
included in the Selected Remedy because of the following considerations:
• Beginning with smaller scale removals to refine cost-effective sediment removal
or management techniques
• Confirming that removal can be conducted in a manner that will not exacerbate
lead movement downstream
• Limiting uncertainty with respect to repository capacity for disposal of the
contaminated sediment removed from the river beds
• Limiting the area of removal work to natural sediment deposition areas, thereby
limiting the effects of potential recontamination and effects on boating activities,
while enhancing cost-effectiveness
• Insuring that the entire depth of contaminated sediment is excavated at the
selected location(s) to eliminate the potential for adverse impacts as a result of
exposing deeper, more contaminated sediments than those present on the surface
of the river bed
EPA, in consultation with stakeholders, also evaluated a narrower scope of remedies. No action
for river-bed sediments was evaluated; however, the bed sediments are a large source of
particulate lead, which, when deposited in the lateral lakes during flood events, has had severe
effects on wildlife. It was considered necessary to begin removing some of the most highly-
contaminated sediments to reduce future downstream effects, as well as to begin developing
cost-effective, implementable methods of sediment removal. Removal or stabilization of less
length of contaminated river bank was also evaluated; however, removal of banks that are highly
susceptible to erosion, as is proposed under the Selected Remedy, would be relatively
implementable, could be conducted at a reasonable cost, and would increase protection of birds
and animals in riparian areas. In addition, stabilization of a smaller amount of erosion-
susceptible bank would likely result in a greater risk of downstream recontamination compared
to the Selected Remedy.
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12.2.2 Estimated Cost of the Selected Remedy
Detailed cost estimates are presented in the tables listed here.
• Table 12.2-3: Ninemile Creek. Cost estimates were developed both with and
without costs for the contingent actions at removal action sites (Interstate,
Success, and Rex) and the treatment pond. Assuming none of the contingent
actions will be required, the total estimated present worth cost for the Selected
Remedy for Ninemile Creek is $13,500,000. The net present worth of 30 years of
O&M is $1,500,000. The estimated average annual O&M cost is $120,000.
The costs for the contingent actions at removal action sites (Interstate, Success,
and Rex) and the treatment pond are:
Contingent actions at removal action sites: $16,500,000
Treatment pond: $6,000,000
These actions would be conducted if needed to achieve the benchmarks for
Ninemile Creek. Assuming all remedial actions described in the previous section
will be necessary to achieve the benchmarks (including contingent actions), the
total estimated present worth cost for the Selected Remedy for Ninemile Creek is
$36,000,000. The net present worth of 30 years of O&M is $6,000,000. The
estimated average annual O&M cost is $480,000.
• Table 12.2-4: Pine Creek. The total estimated present worth cost for the Selected
Remedy for Pine Creek is $14,000,000. The net present worth of 30 years of
O&M is $2,100,000. The estimated average annual O&M cost is $170,000.
• Table 12.2-5: Canyon Creek. The total estimated present worth cost for the
Selected Remedy for Canyon Creek is $35,000,000. The net present worth of 30
years of O&M is $18,000,000. The estimated average annual O&M cost is
$1,500,000.
• Table 12.2-6: South Fork. The total estimated present worth cost for the Selected
Remedy in the South Fork is $16,000,000. The net present worth of 30 years of
O&M is $1,400,000. The estimated average annual O&M cost is $110,000.
• Table 12.2-7: Lead in floodplains. The total estimated present worth cost for the
Selected Remedy for lead in the Lower Basin floodplains is $81,000,000. The net
present worth of 30 years of O&M is $7,200,000. The estimated average annual
O&M cost is $580,000.
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• Table 12.2-8: Particulate lead in surface water. The total estimated present worth
cost for the Selected Remedy for particulate lead in surface water is $71,000,000.
The net present worth of 30 years of O&M is $5,100,000. The estimated average
annual O&M cost is $400,000.
The total estimated present worth cost of the Selected Remedy for protection of the environment
in the Upper Basin and Lower Basin is $250,000,000, including costs for contingent actions.
The total estimated net present worth of 30 years of O&M is $40,000,000. The estimated
average annual O&M cost is $3,200,000.
The estimated costs in these detailed cost estimate tables are based on the best available
information regarding the anticipated scope of the remedial alternative. 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. Changes may be documented in the form of a
memorandum in the Administrative Record file, an ESD, or a ROD amendment. This is an
order-of-magnitude engineering cost estimate that is expected to be within +50 to -30 percent of
the actual project cost, consistent with RI/FS guidance.
The costs presented are present worth costs. The present worth cost is the sum of the capital
costs and the present value of the O&M costs over the period of performance. Consistent with
current CERCLA guidance, estimates of O&M present worth costs assume a discount rate of 7
percent and a 30-year period of performance (USEPA 2000b). O&M costs will vary from year to
year. The estimated average annual O&M cost was calculated by dividing the net present worth
of O&M by the 30-year present worth factor (12.4).
Because the remedial actions have not been staged or phased over time, all capital costs are
considered present worth costs assuming year 2000 dollars.25 The effect of remedy staging over
an approximately 30-year implementation period would be to reduce the present worth cost of
both capital and O&M costs.
Some components of the remedy are expected to have O&M requirements that extend beyond
the assumed 30-year period of performance. The added incremental cost of O&M in perpetuity
compared to 30 years of O&M is 15 percent for a 7 percent discount rate. The potential increase
of the present worth cost of the remedy resulting from O&M beyond the 30-year performance
period is expected to be less than the potential reduction of the present worth cost of the remedy
resulting from remedy staging.
25 The costs in this ROD are based on costs presented in the Feasibility Study (FS), which were developed using
year 2000 cost data.
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12.2.3 Expected Outcomes of the Selected Remedy
This section describes the expected outcomes of the Selected Remedy in terms of benchmark
cleanup criteria, anticipated benefits to human health and the environment, land uses,
groundwater uses, and socio-economic and community impacts.
Benchmark Cleanup Criteria
Benchmark cleanup criteria for surface water are based on target levels of fisheries. The
benchmark water quality conditions are expressed as multiples of the AWQC, based on the
current understanding of the conditions consistent with the targeted fisheries (USEPA 2001d).
As fisheries conditions are monitored during and after cleanup, the benchmark cleanup criteria
may need to be modified. The benchmark cleanup criteria for dissolved metals in surface water
are:
• Tier 1: Migration corridor. Expected to be achieved at dissolved metals26
concentrations less than 20 times the acute AWQC.
• Tier 2: Resident salmonid fishery of any species. Expected to be achieved at
dissolved metals concentrations between 7 times and 10 times the chronic
AWQC.
• Tier 3: Resident salmonid fishery with three or more age classes, including
young-of-the-year. Expected to be achieved at dissolved metals concentrations
between 3 times and 7 times the chronic AWQC.
• Tier 4: Resident salmonid fishery with three or more age classes, including
young-of-the-year, and sculpin. Expected to be achieved at dissolved metals
concentrations between 1 times and 3 times the chronic AWQC.
• Tier 5: Resident salmonid fishery with five or more age classes, including young-
of-the-year, sculpin, and bull trout. Fauna dominated by native species at high
densities (0.1 to >0.3 fish per square meter). Least impacted watershed with
dissolved metals concentrations less than the chronic AWQC.
The benchmark fisheries tiers are shown in Table 12.2-1.
26 For the definitions of fisheries tiers, AWQC are equal to the EPA-approved State of Idaho water quality standards
for cadmium and zinc (see Tables 8.2-2 and 8.2-3). The concentration ranges are unaffected by the 2001 update to
cadmium criteria.
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There are no promulgated cleanup criteria or standards that are ARARs for the soil or sediment
of the Upper Basin and Lower Basin. Lead is the main risk driver in the soil and sediment and
accordingly, EPA has identified lead as the preferred metal to be used as a benchmark.
Background lead concentrations in the soil and sediment of the Lower Basin are estimated to be
47.3 mg/kg (see Table 7.2-7), whereas lead concentrations in soil and sediment in the impacted
areas are typically 3,500 to 4,000 mg/kg.
To establish a benchmark cleanup criterion for sediment, EPA examined site-specific data and all
other available relevant information. For sediment in the wetlands and lateral lakes areas of the
Lower Basin, a site-specific lead level of 530 mg/kg has been identified by the USFWS as the
LOAEL for waterfowl (Beyer et al. 2000). The USFWS has noted that soil and sediment in 95
percent of the floodplain habitat area the Lower Basin has lead concentrations greater than 530
mg/kg. Using all available lines of evidence, the EcoRA also estimated a range of sediment lead
concentrations protective of aquatic birds and mammals. The lead concentrations potentially
protective of aquatic birds and mammals include (see also Table 7.2-7):
• 3.65 mg/kg - NOAEL for protection of individuals
• 249 mg/kg - LOAEL for protection of populations
• 718 mg/kg - based on an ED2o for populations
Given the absence of promulgated criteria for metals in soil and sediment, EPA made a risk
management decision to use the site-specific protective value of 530 mg/kg lead as the
benchmark cleanup criterion for the soil and sediment in the Lower Basin. This value is based
upon data recently collected in the Coeur d'Alene Basin. It is also within the range of potentially
protective values from the literature and other sites. While 530 mg/kg lead in soil/sediment may
not be fully protective of aquatic birds and mammals, it will address 95 percent of the habitat
area. Only 5 percent of the impacted area in the Lower Basin is estimated to have lead
concentrations between 530 mg/kg and background. For these reasons, EPA believes that
selection of 530 mg/kg lead as the benchmark cleanup criterion for soil and sediment is
technically the best alternative available at this time.
In riparian areas where remedial actions are conducted (e.g., banks and tributaries), risks to
riparian receptors will be mitigated using removal and replacement with clean soil or capping
with clean soil to isolate contaminants and reduce or eliminate exposure pathways.
It is important to recognize that numerical cleanup criteria for soil and sediment may be revised
as additional information becomes available. For example, EPA anticipates conducting studies
to evaluate soil and sediment cleanup criteria that are protective of migratory birds in riparian
and riverine habitats. As part of this effort, EPA Region 10 and USFWS are currently assessing
concentrations in soil and sediment that would be protective of riparian songbirds. Any revisions
to criteria would be documented in future decision documents.
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A reduction of dissolved metals loads in the Spokane River of approximately 16 percent is
estimated to result from implementation of the Selected Remedy. Additional load reductions
would result from implementation of remedies in the Box. The estimated reduction needed in
high-flow particulate lead load is at least 50 percent to reduce year-round lead concentrations to
below chronic AWQC in the Spokane River.
Anticipated Benefits
The remedy selected in this ROD is anticipated to result in significant benefits for protection of
the environment, as well as benefits for recreational and subsistence users. Although it would
not achieve all long-term goals, it makes a significant step toward achieving those goals.
Figure 12.2-15 illustrates the relationship between the Selected Remedy and the long-term
remedy that, based on current information, EPA believes is needed for full protection of human
health and the environment and compliance with ARARs. Some of the specific benefits
anticipated include:
• Providing varying levels of fisheries (adult fisheries, areas capable of supporting
spawning and rearing) connected with migratory corridors to allow increased
movement between the tributaries and the river. This would include re-
establishment of fisheries in Ninemile Creek, improvements of spawning and
rearing fisheries in Pine Creek, and improvements in the fisheries, migratory
corridors, and water quality in the South Fork and Lower Basin. Figure 12.2-16
shows the benchmarks for improvements in fisheries conditions in the Upper
Basin. Table 12.2-2 summarizes the fisheries benchmarks for the Selected
Remedy, current water chemistry and physical conditions, and the water
chemistry and physical conditions that the Selected Remedy is expected to
achieve. The Selected Remedy is not anticipated to provide conditions that would
allow re-establishment of the bull trout, which is listed as "threatened" under the
ESA.
• A reduction of about 580 pounds per day of dissolved zinc loads from the Upper
Basin and Lower Basin (URS 2002b). The reduction in load will result in
reduced concentrations of metals in the river system. Figures 12.2-17 and 12.2-18
show the expected values of dissolved zinc concentrations (expressed as multiples
of the AWQC) at Pinehurst and Harrison, respectively, after implementation of
the Selected Remedy is completed (time = 0 on the graph). A range of
concentrations is shown because the effectiveness of remedial actions to be
implemented in the Box is not currently known. The expected values of dissolved
metals concentrations after implementation of the remedy are consistent with a
Tier 1 to Tier 3 fishery in the South Fork at Pinehurst and a Tier 3 fishery in the
Coeur d'Alene River at Harrison.
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• Additional protection of recreational and subsistence users through cleanup of 31
recreational areas in the Lower Basin.
• An addition of 2,669 acres of safe wetland feeding area and 1,859 acres of safe
lake feeding area in the Lower Basin.27 In these areas soils and sediments with
lead exceeding 530 mg/kg would be remediated to provide protection of
waterfowl and other birds protected under the MBTA. These actions are expected
to result in a reduction in waterfowl mortalities.
• Biostabilization of 33 miles of Coeur d'Alene River bank that is a source of
particulate lead to reduce downstream lead loading and recontamination. This
action would include cleanup of the adjacent riparian zone, thereby providing
additional safe habitat for ecological receptors and additional protection for
recreational and subsistence users.
• Cleanup of riparian habitat, including riparian buffer zones along an estimated 33
miles of the Coeur d'Alene River in the Lower Basin; 1.7 miles of East Fork
Ninemile Creek, 2.6 miles of East Fork Pine Creek; riparian areas within or
adjacent to Thompson Lake, Thompson Marsh, Anderson Lake, Cave Lake, Bare
Marsh, Medicine Lake, and Lane Marsh; and oases of riparian habitat at
streamside removal areas along the South Fork. The cleanup would provide safe
habitat for birds protected under the MBTA and other riparian zone plants and
animals.
• Removal of 1,300,000 cy of river bed sediments from natural depositional areas
over the duration of the Selected Remedy to reduce downstream lead loading and
recontamination. This 1,300,000 cy represents 6 percent of the 20,500,000 cy of
contaminated river bed sediments in the Lower Basin.
• Improvements to water quality conditions in the Spokane River. Based on
probabilistic modeling and current estimates of remedy effectiveness, the Selected
Remedy is anticipated to reduce the dissolved metals load in the Coeur d'Alene
River at Harrison by approximately 16 percent. Assuming a consistent rate of
dissolved metals retention in Coeur d'Alene Lake, it is anticipated that
implementation of the Selected Remedy would result in a reduction of dissolved
metals loads in the Spokane River of approximately 16 percent. Additional
reductions of dissolved metals load would occur as a result of remedial actions
27 The acres of lake area shown are the entire areas of the lakes. To develop estimated costs, it is anticipated
contaminated sediments will be cleaned up to a water depth of six feet (which represents an average of
approximately 25 percent of the total lake area). These water depths represent the highest use feeding areas and,
consequently, the areas of greatest exposure to waterfowl and other animals.
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that have been implemented within the Box, as well as future Phase 2 remedial
actions within the Box.
Available Land Uses
Most of the area addressed by the Selected Remedy consists of riparian, wetland, and lake
habitat within the 100-year floodplain in the Lower Basin and remote sites and areas within the
100-year floodplain in the Upper Basin. The anticipated future land uses in these areas are
wildlife habitat, recreational use, and subsistence use.
Some former mine and mill sites within the Upper Basin that are not within the 100-year
floodplain have the potential for redevelopment for commercial or residential use. At sites
where contaminated materials are left on site, institutional controls would be required to manage
potential exposures and maintain the integrity of the remedy. Institutional controls to prevent
development of groundwater as a drinking water source would be needed at most sites.
Institutional controls will be needed in the Upper Basin and Lower Basin to ensure the continued
effectiveness of the Selected Remedy and to prevent land uses that are inconsistent with the level
of protection achieved by the Selected Remedy. These institutional controls could include:
• Physical measures, such as fences and signs, to limit activities that may interfere
with the cleanup action or result in exposure to hazardous substances at the site
• Legal and administrative controls, such as zoning restrictions, environmental
protection easements, restrictive covenants, or equitable servitudes used to ensure
such measures are maintained
Implementation of the Selected Remedy will require some land for management of waste
materials that are generated by the cleanup activities. Management of waste materials is
discussed in Section 12.5.
Available Groundwater Uses
The Selected Remedy does not address groundwater use. It is not anticipated that additional
available uses of groundwater would result from implementation of the Selected Remedy.
Socio-Economic and Community Impacts
Implementation of the Selected Remedy is expected to improve the socio-economic conditions of
the Coeur d'Alene Basin. The elements of the remedy focusing on water quality improvements
and the subsequent increase in fish populations and diversity will likely expand the recreational
use of this resource. Remediation of the riverbanks will slow erosion and improve the riparian
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corridor for greater recreational use. Cleanup of easily accessible abandoned mine sites will
allow redevelopment of these properties and increase tax revenues. The work associated with
implementation of the Selected Remedy may provide additional jobs for the local labor force and
contractors. The long duration of the work should encourage investment in training and
development of the local labor force to establish the necessary skills and expertise that can pay
off for the workers and contractors for many years. This should result in growth of the tax base
for local economic benefit. The work may also provide opportunities for local supply
contractors. Additionally, remediation dollars spent in the Silver Valley may create other
opportunities for local businesses.
12.3 COEUR D'ALENE LAKE
Coeur d'Alene Lake is not included in the Selected Remedy. State, tribal, federal, and local
governments are currently in the process of implementing a lake management plan outside of the
Superfund process using separate regulatory authorities.
The sediments at the bottom of the lake contain mining contamination, and the rate of release of
metals in the sediments into the water column could increase if the lake water quality
deteriorates due to nutrient enrichment. Currently, however, more metals enter the lake annually
from the Coeur d'Alene River than flow out of the lake into the Spokane River. This and other
information indicate that the lake sediments are a smaller source than riverine inputs. Based on
currently available information, active remediation (e.g., removal, capping) of lakebed sediments
is not warranted.
The lake management plan would focus on reducing riverine inputs of metals and nutrients that
continue to contribute to contamination of the lake and the Spokane River. Activities included in
the plan are (Coeur d'Alene Tribe, et al. 1996):
• Best management practices to control erosion from littoral areas of the lake and
watersheds that feed the lake
• Residential and municipal sewer systems improvements to reduce nutrient
loadings entering the lake from these sources
• Where necessary, upgrading of municipal water treatment plants to reduce
nutrient contributions to the lake
• Bank stabilization to reduce erosion of river banks. Establishment of "no wake"
zones has also been suggested to reduce erosion of river banks
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The Coeur d'Alene Tribe, IDEQ, and EPA, along with others, plan to coordinate a
comprehensive lake monitoring program to evaluate the effects of upstream cleanup, potential
sources of contamination, and potential impacts to the lake and the Spokane River. If conditions
change or new information that modifies the current understanding becomes available, additional
actions will be evaluated. Evaluation of lake conditions will be included in the five-year review
process.
Some questions have been raised regarding the need to further evaluate potential risks to humans
who eat whole fish or fillets taken from fish in the lake. Previous fish tissue sampling efforts did
not include whole fish from Coeur d'Alene Lake, and only a limited number of fillets were
sampled. As a result, some uncertainty remains about the potential risks resulting from eating
fish from the lake. Additional fish sampling was conducted in 2002, and results of the sampling
should be available in early 2003.
12.4 SPOKANE RIVER
Cleanup of community and residential areas, including the identified recreational areas, to
minimize human health exposure is a top priority. For the Spokane River in Idaho, the Selected
Remedy does not include any remedial actions. The beaches and wading areas adjacent to the
Idaho portion of the Spokane River were sampled in 1998 and were found to be safe; i.e.,
concentrations of metals did not exceed risk-based levels for recreation.
At present, the risks to persons, including Spokane tribal members, and others who may practice
a subsistence lifestyle in the Spokane River area have not been quantified. EPA and the Spokane
Tribe are cooperating in planning additional testing and studies that will be implemented to
evaluate the potential exposures to subsistence users. The results of those tests and studies will
determine appropriate future response actions to be taken, if any.
For the Spokane River in Washington, the Selected Remedy includes all of the remedy for
protection of human health upstream of Upriver Dam and protection of the environment between
the Washington/Idaho state line and Upriver Dam. The Selected Remedy consists of a
combination of access controls, capping, and removals from Spokane River Alternatives 3, 4,
and 5. This remedy was also the Preferred Alternative in the Proposed Plan.
The Selected Remedy for the Spokane River is summarized in Table 12.4-1.
12.4.1 Description
For the Washington portion of the Spokane River, a limited number of sediment and soil sites in
and adjacent to the Spokane River have been identified for cleanup on the basis of potential
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human and ecological exposures. The sites are located along a 16-mile reach of the river
between the Idaho/Washington state line and Upriver Dam, which is upstream of the city of
Spokane. The identified areas include 10 shoreline sites and a subaqueous site where
contaminated sediments have accumulated directly behind Upriver Dam. The areas are shown in
Figure 12.4-1.
The Selected Remedy to protect human health and the environment at these areas draws from
Spokane River Alternatives 3, 4, and 5. The Selected Remedy includes a combination of access
controls, capping, and removals for the shoreline sites.
The remedy for the contaminated sediments behind Upriver Dam will be established following
further study and engineering evaluation. Dredging or capping are the options anticipated for
sediments behind the dam. The sediments behind the dam are contaminated with PCBs, in
addition to metals. The PCBs are currently being investigated under the State of Washington
MTCA. The Washington State Department of Ecology (Ecology) is working with the
responsible parties to conduct a RI/FS of the sediment behind the dam. EPA and Ecology intend
to coordinate remediation to minimize unnecessary duplication and cost.
There is some potential for recontamination of the shoreline cleanup sites. Fine-grained, metal-
rich sediments coming from the Coeur d'Alene River Basin and metal-rich sediments previously
deposited along the upper river may come to rest on remediated locations. Because of this
concern, a phased approach may be used. The locations initially remediated can be monitored
for recontamination and cleanup work modified as necessary. If recontamination is a problem,
the location involved may undergo periodic follow-up contaminant removal or maintenance of
the clean-soil cover.
Other actions along the Spokane River include water-quality monitoring, aquatic-life monitoring,
remedial-performance monitoring of sediments, and contingencies for additional or follow-up
cleanups. Other than the cleanup actions for impacted shorelines and sediments, measurable
improvements to water quality in the river must rely primarily on actions performed upstream.
Thus, the degree and duration of potential recontamination and the measurement of
improvements to ambient surface-water quality will be closely tied to the pace and scope of the
cleanup actions in the Lower Basin and Upper Basin, as well as to the long-term retention of
metals in Coeur d'Alene Lake sediments. As described in Section 12.2.3 Anticipated Benefits, a
reduction of dissolved metals loads of approximately 16 percent is anticipated to result from
implementation of the Selected Remedy.
12.4.2 Estimated Remedy Costs
The estimated remedy costs for the Spokane River are summarized in Table 12.4-1. A range of
estimated costs was developed. The lower range was developed based on capping of
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contaminated sediments. The upper range was developed based on excavation and disposal of
contaminated sediments. The lower range total estimated present worth cost is $4,500,000 with
a net present worth of 30 years of O&M of $1,400,000. The estimated average annual O&M
cost is $110,000. The upper range total estimated present worth cost is $11,000,000 with a net
present worth of 30 years of O&M of $1,300,000. The estimated average annual O&M cost is
$100,000.
The estimated costs in this table are based on the best available information regarding the
anticipated scope of the remedial alternative. 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. Changes may be documented in the form of a memorandum in the Administrative
Record file, an ESD, or a ROD amendment. This is an order-of-magnitude engineering cost
estimate that is expected to be within +50 to -30 percent of the actual project cost, consistent
with RI/FS guidance.
The costs presented are present worth costs. The present worth cost is the sum of the capital
costs and the present value of the O&M costs over the period of performance. Consistent with
current CERCLA guidance, estimates of O&M present worth costs assume a discount rate of 7
percent and a 30-year period of performance (USEPA 2000b). O&M costs will vary from year to
year. The estimated average annual O&M cost was calculated by dividing the net present worth
of O&M by the 30-year present worth factor (12.4).
Because the remedial actions have not been staged or phased over time, all capital costs are
considered present worth costs assuming year 2000 dollars.28 The effect of remedy staging over
an approximately 30-year implementation period would be to reduce the present worth cost of
both capital and O&M costs.
Some components of the remedy may have O&M requirements that extend beyond the assumed
30-year period of performance. The added incremental cost of O&M in perpetuity compared to
30 years of O&M is 15 percent for a 7 percent discount rate. The potential increase of the
present worth cost of the remedy resulting from O&M beyond the 30-year performance period is
expected to be less than the potential reduction of the present worth cost of the remedy resulting
from remedy staging.
12.4.3 Expected Outcomes of Selected Remedy
This section describes the expected outcomes of the Selected Remedy in terms of cleanup levels
and residual risks, land uses, groundwater uses, and socio-economic and community impacts.
28 The costs in this ROD are based on costs presented in the Feasibility Study (FS), which were developed using
year 2000 cost data.
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Cleanup Levels and Residual Risks
The sediment lead cleanup level is 700 mg/kg for recreational use. For children's exposure to
lead, it was assumed that 92 percent of the total exposure occurs at the home and 8 percent
occurs during recreation. The total exposure was established such that the probability is 5
percent or less of a typical child having a blood lead level exceeding 10 (j,g/dL and 1 percent or
less of a typical child having a blood lead level exceeding 15 (j,g/dL. The sediment cleanup level
will reduce children's exposure to lead such that the recreational component of the total lead
exposure is not exceeded. The 10 shoreline sites shown in Figure 12.4-1 exceed State of
Washington regulations for cleanup standards, as defined in WAC 173-340-740, for protection of
human health based on lead or arsenic risk-based concentrations. Critical ecological habitat
goals will be addressed concurrently with the human health actions in those areas where they are
co-located.
Sediments accumulated behind Upriver Dam will be cleaned up to levels that will not pose an
unacceptable risk to aquatic organisms and will reduce to acceptable levels the potential for
exposure of recreational users to contaminated sediment resulting from mobilization and
redeposition of the contaminated sediments in areas downstream of the dam.
Cleanup of critical habitat areas identified by Ecology will reduce risks to waterfowl and other
ecological receptors to generally safe levels. The critical habitat areas identified by Ecology are:
• CUA201 (StarRd)
• DA06/07/08 (Island Complex)
• DA10 (Murray Rd)
• CUA202 (Harvard Rd, N Bank)
Implementation of the Selected Remedy for the Spokane River is not anticipated to result in
significant reductions of metals concentrations in surface water, which will be closely tied to the
pace and scope of the cleanup actions in the Lower Basin and Upper Basin, as well as the long-
term retention of metals in Coeur d'Alene Lake sediments.
The anticipated future land uses of the shoreline and sediment depositional areas addressed by
the Selected Remedy are wildlife habitat, recreational use, and subsistence use. Future
commercial or residential use is not anticipated.
Land Uses
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Groundwater Uses
The Spokane Valley aquifer is a designated "sole source" aquifer. The aquifer is recharged, in
part, by surface water from the upper Spokane River; however, use of groundwater is not limited
by the presence of metals. Therefore, the remedy does not address potential future groundwater
use. The concentrations of metals in Spokane River water are well below drinking water
standards. In addition, a surface water groundwater interaction study in the upper Spokane River
indicated that dissolved metals entering the aquifer from the river in this area are not migrating
far beyond the river bank or are being diluted by aquifer water (Marti and Garrigues 2001).
Socio-Economic and Community Impacts
Implementation of the remedy will reduce the potential for exposure to metals at beach and
shoreline recreational areas and may enhance human uses of ecological resources. It is
anticipated the Upper Spokane River health advisory regarding ingestion of beach and shoreline
sediments could be lifted. There is also a fish consumption health advisory for the Spokane
River from the state line to Nine Mile Dam. It is likely that lead concentrations in whole fish
will not decline substantially until the amount of lead that reaches the Spokane River from
upstream sources in reduced. These reductions will be closely tied to the pace and scope of the
cleanup actions in the Lower Basin and Upper Basin, as well as the long-term retention of metals
in Coeur d'Alene Lake sediments.
12.5 SITING AND DESIGN OF REPOSITORIES FOR MATERIAL GENERATED BY
CLEANUP ACTIVITY
Implementation of the remedy will require construction of repositories for disposal of metals-
contaminated soils, sediments, debris, and treatment residuals. All disposal locations will be
evaluated using the same process and criteria. All locations will also be subject to long-term
institutional controls and monitoring (if necessary) to ensure the integrity of the remedy.
Waste consolidation areas designed and constructed in the Coeur d'Alene Basin pursuant to this
ROD will only be able to receive material generated by the cleanup activity associated with the
Selected Remedy in this ROD, including material generated through the Basin Institutional
Controls Program and related CERCLA removals in the Basin. This material will include soils,
house dust, debris, alluvial and fluvial soils, and sediment contaminated by mining extraction
and beneficiation waste released from historic mining facilities in the Coeur d'Alene Basin. This
material, along with tailings and waste rock that may be consolidated in repositories as well, is
exempt from Resource Conservation and Recovery Act (RCRA) Subtitle C hazardous waste
management requirements pursuant to the Bevill Amendment (42 U.S.C. §6921(b)(3)(A)(ii).
Repositories constructed pursuant to this ROD will be designed to reliably contain waste
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material and prevent the release of contaminants to surface water, groundwater, or air in
concentrations that would exceed state and/or federal standards.
Principal threat wastes (such as metal concentrates) and non-Bevill-exempt hazardous waste will
be disposed of at an off-site facility or may be disposed of on-site with additional treatment
and/or additional engineering measures. Treatment may consist of stabilization of waste
materials. Engineering measures may consist of construction of an enhanced cap to prevent
leaching or a lined principal threat materials cell to contain highly concentrated and/or highly
mobile material.
A four-step process will generally be used to evaluate potential repository locations and specify
design requirements.
1. Site Identification. A list of potential repository sites will be prepared in conjunction with
other Basin stakeholders. Additional locations will be identified where local governments and/or
property owners have an interest in receiving material generated from cleanup actions.
2. Technical Evaluation. Potential repository sites will be evaluated using site-specific data
and the repository location and design guidelines described below.
Repositories will be located and designed to:
• Prevent adverse human health or ecological impacts and result in improvements
wherever possible
• Prevent additional groundwater and/or surface water impacts
• Integrate with past or nearby cleanup efforts
• Comply with all ARARs
• Be appropriate for the characteristics of the waste that will be disposed of there
• Be cost-effective
• Minimize long-term operation and maintenance (O&M) costs
Additional considerations include:
• Transportation impacts and costs
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• Economic development or future reuse of the site where feasible
• Absence or presence of mining-related contaminants
• Geotechnical stability
• Availability of clean cover material
• Community acceptance
3. Public Input/Notification. Concurrent with the technical evaluation, a public outreach effort
will be initiated. Affected citizens and stakeholders will be given an opportunity to comment on
the proposed repository location and design.
4. Decision Documentation. Upon completion of the public outreach efforts, remedial design
documents will be prepared that include, but are not limited to, the following issues for each
repository:
• Rationale for Repository Selection. For example:
- Evaluation of repository location with respect to surrounding environmental
conditions
- A summary of public outreach efforts
• Design Requirements and Rationale. For example:
- Description of selected cover system (or systems if multiple cells) and
liner/leachate collection requirements, if any
- Construction configuration and ultimate final grading and geometry of
repository including stormwater management and terracing
- Results of hydrogeologic and hydrologic modeling/characterization of the
cover system and repository and surrounding environment
- Special considerations, if any, due to repository location such as proximity to
floodplain or surface water bodies or geotechnical concerns
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- Identification and rationale for compliance with any applicable or relevant and
appropriate requirements as well as any other guidance identified as "To Be
Considered" as outlined in Section 12 of this ROD
• General Operating Requirements During Remedial Action. For example:
- Standard operating procedures for site including hours of operation, site
access, dust control, decontamination, and record-keeping requirements
- Waste acceptance criteria including allowable chemical concentrations,
moisture content, percent allowable debris, and dimensions of material
- Sampling requirements for characterization of incoming waste
- Any pretreatment requirements (e.g., stabilization, de-watering) prior to waste
disposal
- Waste placement requirements including lift thickness and compaction
requirements
• Post-Closure O&M Requirements. For example:
- Post-closure monitoring of groundwater and surface water runoff
- Institutional controls and limitations on future land use
- Maintenance plan for the final cover
It is not known, at this point in time, how many repositories will be needed to support the
Selected Remedy in this ROD. The estimated volumes of material that may require excavation
and disposal are about 500,000 to 900,000 cy in the Upper Basin and about 2,600,000 cy in the
Lower Basin (including approximately 1,300,000 cy of river bed sediments, 500,000 cy of river
bank and splay material, and 800,000 cy of wetland and lateral lake sediment). By comparison,
there are currently about 2,100,000 cy of tailings in the Hecla-Star Tailings Ponds in lower
Canyon Creek and about 26,000,000 cy of waste material in the Central Impoundment Area.
Exact repository locations and design requirements will be developed, with community input,
using the four-step process outlined above.
Where there are two or more noncontiguous contaminated areas that are reasonably related on
the basis of geography, or on the basis of the threat, or potential threat, to the public health or
welfare or the environment, CERCLA section 104(d)(4) and the preamble to the NCP (40 CFR
8690) allows EPA to treat these related areas as one area of contamination (AOC) for response
purposes and, therefore, allows the lead agency to manage waste transferred between such
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noncontiguous areas without having to obtain a permit. Within the Coeur d'Alene Basin, the
repositories and material generated by the cleanup activity associated with the Selected Remedy
in this ROD will be related on both the basis of geography and on the basis of the threat to public
health or welfare and the environment. In addition, these wastes will be compatible with the
selected disposal approach in the repositories. Thus, consolidation of these wastes in a
repository will not require permits even if the waste site and repository location are determined
to be noncontiguous.
No lakes will be sacrificed as repositories. However, some cleanup projects may involve
consolidation and capping of contaminated materials within a wetland or lake area to reduce
ecological impacts (e.g., subaqueous capping). Other projects may involve the consolidation and
stabilization of contaminated sediments and river bank material. Remedies that involve
consolidation and capping of materials "in place" are not subject to the same siting requirements
as remedies that involve removing material from one location and consolidation of that material
in a repository.
12.6 MONITORING AND ADDITIONAL DATA NEEDS
EPA is currently working with Coeur d'Alene Basin stakeholders to collaboratively develop a
Basin environmental monitoring program. Organizations involved with EPA in development of
the monitoring program include IDEQ, Ecology, CDA Tribe, Spokane Tribe, USFWS, USGS,
and BLM. The aforementioned parties were involved in the development of the remedy
identified in this ROD and are knowledgeable about the remedy, Basin conditions, and
monitoring needs. The program will be established as part of the Selected Remedy and is critical
to the successful implementation and evaluation of the remedy.
The primary goals of the human health monitoring activities will be to evaluate the effectiveness
of remedial actions in the residential and community areas and provide data for EPA to conduct
CERCLA-required five-year reviews of the progress made on remedy implementation. For
example, soil sampling will be conducted to document post-cleanup concentrations of lead and
arsenic, and drinking water monitoring will be conducted for those homes on contaminated
private wells that are not connected to public drinking water systems due to annexation and
engineering issues (e.g., homes where point-of-use treatment is implemented).
The key goals of the environmental monitoring program will be to evaluate the effectiveness of
remedial actions, evaluate progress toward achievement of benchmarks, and gain a better
understanding of Basin processes and data variability. The monitoring will also provide data for
EPA to conduct future CERCLA-required five-year reviews of progress on remedy
implementation. Five-year reviews will need to address the progress toward achieving the
ecological focuses for remedial action (e.g., dissolved zinc and cadmium in surface water,
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particulate lead in surface water, and lead in flood plain soils and sediments) and progress toward
the benchmarks (see Table 12.2-1). To the extent feasible, the long-term monitoring is expected
to integrate with monitoring conducted by other entities (e.g., IDEQ, Ecology, USGS, etc.) as
part of other program requirements. Given the scope of the project, the long time frame, and
difficult budget forecasts, every effort will be made to ensure that the monitoring be effective,
streamlined and targeted to answer key questions.
The environmental monitoring program is envisioned to have two main components. The first
component would provide an overarching status and trends assessment of the surface water, soil,
sediment, and biological resources conditions in the Basin. The status and trends monitoring is
expected to continue for many years, but would be implemented at a manageable frequency and
intensity. Some monitoring parameters may be triggered by events (e.g., high flow events may
trigger flood plain sediment monitoring). Other monitoring may occur on a periodic frequency
(e.g., quarterly, annually, once every five years, etc.) and at locations which represent key nodes
or points of significant chemical or ecological importance. The monitoring is anticipated to have
surface water, soil/sediment, and biological aspects. Since groundwater is not addressed in this
ROD, groundwater monitoring will likely be limited to the situations in which groundwater data
is needed to address specific surface water questions.
The second component of the monitoring program is action-specific monitoring which will be
linked with the overarching status and trends monitoring program. The remedial action-specific
effectiveness monitoring will be developed as part of the design of each remedial action.
The basin-wide status and trends environmental monitoring program, as well as the remedial
action-specific effectiveness monitoring, will be structured to provide data needed to evaluate the
following issues:
Trends in dissolved zinc and cadmium concentrations in surface water
Trends in particulate lead loads and concentrations in surface water
Trends in lead concentrations in the flood plain soils/sediment, levees, and river
bed sediment
Progress toward achieving the benchmarks of the Selected Remedy
Potential unwanted impacts to the system (e.g., recontamination, nutrient loading,
excess sedimentation, etc.) resulting from implementation of the remedy
Changes or trends in biotic benchmarks (e.g., population/diversity, chemical
exposure, bioavailability, etc.)
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• Trends in water quality, sediments, and biological resources in Coeur d'Alene
Lake
• Trends in groundwater quality, where appropriate to evaluate impacts to surface
water
In addition to monitoring needs, EPA recognizes that some areas of the Basin have not been fully
characterized, and additional data collection will be needed. These efforts will include:
• Metals loading sources and pathways in the South Fork from Wallace to
Pinehurst, focused on the Bunker Hill Box and Osburn areas, including the
contribution of metals sorbed/precipitated within aquifer as a limiting factor to the
effectiveness of sediment removals
• The dissolved metals loads originating from the reach from the confluence of the
North Fork and South Fork to Cataldo and from the Mission Flats dredge spoils
area
• The relative magnitude of lead loads originating from the beds and banks in the
Lower Basin
• Recontamination potential of various Lower Basin areas
• Identification of long-term metals flux from Coeur d'Alene Lake
• Identification of cleanup criteria for ecological receptors, including risks to
songbirds in riparian habitats
• Characterization of metals loading to groundwater and surface water from the
Hecla-Star Tailings Ponds
• Additional testing and studies to evaluate the potential exposures to subsistence
users by resources in and along the Spokane River on the Spokane Indian
Reservation
12.7 STATE AND TRIBE ACCEPTANCE
This section evaluates state, tribe, and natural resource trustee acceptance of the Selected
Remedy based on comments on the Proposed Plan submitted by the States of Idaho and
Washington, the Coeur d'Alene and Spokane Tribes, and the Departments of the Interior and
Agriculture. The statements included in Sections 12.7.1 through 12.7.6 were compiled by EPA
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-55
from submittals of the entity referenced in each section heading and reflect the views of the
entity. The full comments submitted by these entities, and EPA's responses to these comments,
are presented in the Responsiveness Summary (Part 3 of this ROD).
For issuance of this ROD, EPA sought formal concurrence from states and tribes only within
their individual jurisdictional boundaries. Because no remedial actions have been selected that
would be implemented within the jurisdictional boundaries of the Spokane Tribe, EPA did not
seek to obtain formal concurrence from the Spokane Tribe. However, EPA recognizes the
concerns of the tribes with respect to contamination within traditional cultural areas that are not
within their jurisdictional boundaries. In addition, EPA recognizes the concerns of the State of
Washington with respect to contamination entering the state through the Spokane River.
12.7.1 State of Idaho Acceptance
As it pertains to work in Idaho, the State of Idaho generally concurs with the Selected Remedy
and agrees with the majority of the final ROD.
Idaho is opposed, however, to any identification of the Lake as part of a "Superfund site" and
will pursue administrative actions to make clear that the Lake is not presently nor in the future
ever identified as part of a "CERCLA site." The Sate of Idaho has similar concerns about
including the Idaho portion of the Spokane River where no remedial actions are identified. The
State believes that the Lake Management Plan process for the Lake and state and local
management mechanisms for the Idaho portion of the Spokane River will provide the appropriate
level of protection to maintain water quality.
The State of Idaho does not believe it is reasonable to speculate in the ROD about the cleanup
work after implementation of the Selected Remedy. Prediction of the environmental situation 30
years into the future is impossible given the unknowns about the effectiveness of remedial
actions and natural attenuation. The State believes that, after full implementation of the Selected
Remedy, environmental conditions must be evaluated and a determination made as to whether
"Applicable or Relevant and Appropriate Requirements" (ARARs) in place at that time have
been met or if waivers will be applied.
Idaho supports the continued development and implementation of innovative treatment
technologies. Idaho supports the adaptive approach outlined in the ROD to take advantage of
new information and technologies.
Idaho insists on and appreciates EPA's support of the Basin Environmental Improvement
Commission as the implementing entity for the ROD.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-56
Idaho believes that there is no health emergency of any kind in the Basin, but there are prudent
voluntary measures to take to assure that individuals are not exposed to contaminants.
Idaho is concerned that removal actions be accomplished in a manner that does not contribute to
additional contamination or disrupt viable ecosystems that currently exist. Idaho's support for
the Selected Remedy is conditional upon its implementation not impacting the rapid completion
of the Phase I and Phase II actions in the "Box" and subsequent deletion actions.
12.7.2 State of Washington Acceptance
While the State of Washington (the State) believes that the Selected Remedy will make progress
towards protection of human health and the environment, the State continues to have concerns
about the scope of the Selected Remedy in Idaho. The State believes additional measures should
have been identified as part of the remedy.
The State believes that measurable water quality improvements in the Spokane River can be
achieved or selected ambient water quality criteria (AWQC) reached if EPA and Idaho were to
establish water quality improvements in the river as a primary interim remedial objective. The
State sought assurances for a remedy cleanup level that would assure at least a 20 percent
reduction in the annual zinc load to the Spokane River, along with achieving total and dissolved
lead AWQC during winter melt or spring runoff events. The State believes these goals are
feasible and justified and could be achieved under an appropriately scoped interim remedy along
with deliberate actions in the Bunker Hill Box. In particular, the State continues to seek
additional or enhanced actions to reduce metals loads in the following areas:
• Canyon Creek. The State continues to seek assurances that the anticipated
passive treatment systems will not be built unless there is a clear indication they
will perform over the long term and represent the best available technology. If
the passive systems are not feasible, if system designs cannot be assured to
perform in a desired fashion or to meet performance goals, then conventional
active treatment system aspects should be incorporated and applied.
• Bunker Hill Box. The State continues to seek commitments from the EPA and
Idaho to pursue vigorous remedies in the Bunker Hill Box with the objective of
significantly reducing dissolved metals reaching surface water and also to assure
the central treatment plant (CTP) is upgraded (avoiding potential catastrophic
releases of metals to the South Fork). Thus, treatment or management of
groundwater impacting the South Fork should clearly be a basin priority, aspects
of which might also potentially be integrated with the CTP reconstruction.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-57
• Mission Flats. The State believes the ROD should clearly include a
hydrogeologic evaluation followed by the design and construction of passive or
active hydraulic/water quality remedial actions to reduce dissolved metals loading
to the Coeur d'Alene River from the dredge spoils at this location.
• Lower Coeur d'Alene River bed sediments. The State concurs that the Dudley
reach should be prioritized as part of the first increment of remedial action
defined in this remedy. The State strongly supports the increase in riverbed
sediment remediation defined in Section 14.0 and appreciates EPA's response to
Washington's citizen concerns. However, the State believes the sediment
removal actions included in the selected remedy are inadequate to definitely
assure long-term, permanent protection of the Spokane River.
• Lake Coeur d'Alene. The State believes EPA should apply all available
regulatory and legal authorities to assure implementation of measures to protect
water quality in the lake and minimize future releases of metals from the lake.
The State believes that for the Lake Management Plan to be successful it must
have the long-term financial and regulatory support of the associated local, state,
tribal, and federal entities in Idaho.
12.7.3 Coeur d'Alene Tribe Acceptance
The Coeur d'Alene Tribe generally supports the Selected Remedy, but has identified areas of
concern.
The tribe does not believe that adequate levels of protectiveness will be achieved once the
ROD is implemented. Other concerns identified by the tribe include:
• The Tribe believes the Selected Remedy does not address the risks to recreational
and subsistence users in the Upper Basin and Lower Basin.
• The Tribe recognizes that additional cleanup actions will be evaluated during and
after implementation of the Selected Remedy, but is concerned that the overall
protectiveness and long-term effectiveness of these actions cannot be evaluated.
• The Tribe is also concerned that the Selected Remedy identifies no sources of
funding for implementation of the Lake Management Plan. The Tribe believes
the Lake Management Plan should be implemented under CERCLA authorities
and be fully funded as an institutional control under CERCLA.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-58
• The Tribe expects CERCLA funding to continue monitoring in Coeur d'Alene
Lake.
12.7.4 Spokane Tribe Acceptance
• The Spokane Tribe generally supports the cleanup activities included in the
Selected Remedy. The Spokane Tribe believes, however, that the Selected
Remedy does not maximize the protection of human health and the environment,
and that additional measures should be implemented during the term of the
remedy's first increment.
• The Tribe believes the Selected Remedy incorporates too many uncertainties and
leaves too many things undone for ARARs to be complied with and human health
and the environment protected. The Tribe believes the time frame contemplated
under the Selected Remedy for achieving ARARs is excessive, and that more
cleanup work should be conducted now.
• The Tribe does not believe the Selected Remedy provides adequate protection of
current and future subsistence users who reside and/or practice subsistence
lifestyles within or near areas scheduled for remediation. Additional testing and
studies to evaluate the potential exposures to subsistence users by resources in and
along the Spokane River on the Spokane Indian Reservation are necessary.
Threats to human health and the environment identified by those tests and studies
should be addressed by future response actions.
• The Tribe believes that EPA's future involvement in the management of Lake
Coeur d'Alene is legally necessary to ensure the long-term enforceability of the
Lake Management Plan.
• The Tribe believes that EPA's approach of employing different remediation goals
based on protection of different uses (e.g., beach goers versus subsistence users)
within different political boundaries will not result in the necessary reduction of
cumulative risk to downstream interests.
• Section 13.2 outlines ARARs and TBCs for this Selected Remedy. Future
evaluations may find threats to the environment and the health of subsistence
users by resources in and along the Spokane River on the Spokane Indian
Reservation, in which case additional ARARs may be identified as appropriate
response actions are considered.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-59
12.7.5 Department of Interior
The Department of Interior (DOI) is concerned that species protected under the ESA and MBTA
will not be fully addressed once the ROD is implemented. Other concerns identified by the DOI
include:
• The DOI would like EPA to select Alternative 3 (at a minimum) and possibly
Alternative 4 (for some areas) as the Selected Remedy for this ROD.
• The DOI would like all contaminated wetlands and lakes to be addressed.
• The DOI is concerned that the remedy is not protective of riparian wildlife.
• The ROD should include language recognizing that work by others may be
conducted consistent with the long-term goals of the remedy.
12.7.6 Department of Agriculture
The Department of Agriculture generally concurs with the Selected Remedy, but has identified
the following areas of concern:
• The interim response action is only a first phase of the necessary actions and as
such, USD A would like EPA to continue to pursue Alternative 3 remedial actions
as the final remedy for the basin.
• The ROD should include language recognizing that work by others may be
conducted consistent with the long-term goals of the remedy.
• Cleanup actions and their effectiveness are iterative processes and, as such,
continued coordination with the Natural Resource Trustees and others needs to be
maintained.
12.8 COMMUNITY ACCEPTANCE
EPA's work in the Coeur d'Alene Basin has been the subject of considerable controversy and
scrutiny. Given the large geographic area encompassed by the study and cleanup activities,
community concerns are numerous and wide-ranging. Public opinion has been sharply divided
about such overarching issues as whether cleanup is needed in the Basin, how much cleanup is
needed, who should be in charge of the cleanup, and the boundaries of the Superfund
designation.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-60
EPA led a collaborative process in developing the Proposed Plan and ROD. All of the regulatory
and land management agencies with jurisdiction in the Basin have been "at the table" for more
than four years and have been directly involved in shaping the cleanup plan. In addition, EPA
coordinated an extensive community involvement program that included four public comment
periods on draft documents prior to the release of the Proposed Plan, participating in more than
200 meetings in a three-year period, monthly newsletter updates, and hiring a local community
liaison (a more detailed description of community involvement activities can be found in
Section 3). By engaging the public and regulatory stakeholders early during the RI/FS and
providing opportunities for input far beyond those required by CERCLA, EPA has been able to
respond to issues and concerns in "real time" as the cleanup plan was being developed.
During the comment period on the Proposed Plan, EPA received more than 1,300 individual
submissions that contained a total of more than 3,300 separate comments. EPA has responded to
each individual comment and has provided a summary of the major comments and responses.
Both the general and detailed comments and responses can be found in Part 3 of this ROD.
As with the four earlier comment periods, a broad range of opinions was represented in the
public comments on the Proposed Plan. Many comments were very general and expressed lack
of support for EPA and other government agencies or expressed the belief that no cleanup is
needed in the Basin. Other comments either generally supported EPA's plan or expressed a
desire for a more aggressive cleanup approach. In developing the Selected Remedy, EPA has
attempted to strike a balance between addressing community and stakeholder concerns and
meeting its legal obligations under CERCLA. Below is a brief summary of the major
community concerns expressed during the comment period for the Proposed Plan.
• Some people continued to express concern about the way the State of Idaho and
EPA assessed the human health risks in the Basin and believe that the risks have
been overestimated. Many of these people therefore believe that residential
cleanups in the Upper Basin are not necessary.
• Some people believe that the risks to the environment have been overestimated, or
they believe that the Basin environment should be allowed to recover on its own
without any active cleanup work.
• Some people expressed concern about the boundaries of the Superfund site and
EPA's plan to "expand" the cleanup in the Basin. Many of these people are
concerned that the stigma associated with Superfund sites stands in the way of
economic progress in the Basin.
• Many people expressed a desire for state and local governments to have a major
role in making cleanup decisions.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-61
• Some people were concerned about how long cleanup will take and EPA's
proposed "incremental approach." These people were concerned that the
incremental approach provides no certainty about when the cleanup will be
finished and when the Superfund designation can be removed from the Basin.
• Many people in Washington State and some in Idaho felt that the cleanup plan
should be more aggressive in order to be more protective of human health and the
environment.
• Some people felt EPA should be in charge of implementing the cleanup because
the contamination crosses a state line and affects tribal lands.
EPA has tried to work closely with people in the communities to understand and address these
concerns. Some of the things people in the Basin continue to be most concerned about, such as
the boundaries of the Superfund site and whether EPA is involved in the cleanup, are outside of
the scope of EPA Region 10's decision-making authority. In the case of the boundaries of the
Superfund site, EPA has applied the CERCLA definition of a Superfund site, not expanded the
boundaries. Because of this, some people feel that EPA has not listened to them, and they are
not satisfied that the cleanup plan addresses their concerns.
Despite the fact that on many issues there are widely divergent opinions, there has steadily been
a growing recognition in the Basin communities that some cleanup work is needed. People agree
that the work should be done as quickly as possible and with as little disruption as possible.
People generally agree that the states, tribes, local governments and citizens should be directly
involved in planning and implementing the cleanup activities that affect them.
EPA has made no assumptions about specific work beyond this Selected Remedy. The Selected
Remedy allows for significant improvements for human health and the environment.
EPA looks forward to working together with all of the people in the Basin to make sure the
cleanup plan is carried out in a way that is acceptable to the communities so that, ultimately, both
the Basin environment and the local economies are improved for this and future generations.
-------
2,500
O)
O)
E
c
o
ro
c
0
o
c
o
O
"D
CD
0
_J
C
CO
0
o
0
E
o
0
0
2,000
1,500
1,000
500
-X- Smelterville Vacuum Dust
- - x- - - Upper and Lower 90th Percentile Confidence Limits for Vacuum Dust
—&— Smelterville Soil
—*— Upper and Lower 90th Percentile Confidence Limits for Yard Soil
Smelterville House Dust from Vacuum Bags
k x
% \
J*--
Smelterville Yard Soil
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
&ERA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.1-1
Smelterville Soil and Dust Lead Geometric Means (1990-2001)
From homes with children participating in the Lead Health Intervention Program
-------
Beach Upstream from Quarry
RV Park across from Blackrock
Blackrock Gulch Beach
Beach below Ward
Lane Beach
Old Mission State Park-
Old Mission State Park Boat Launch -
Beach in Mission Flats —
Killarney Lake Boat Launch
West Beach near Medimont
West of Blue Lake
RM135 Long Beach/Springston
Across River from Springston-
Springston Beach Site
Thompson Lake
Harrison
Dol:o
Thompson
Bare Marsh
Thompson Marsh
bpringston
Anderson Lake
/
Harrison Marsh
v Harrison
C3*
i
N/ ,¦
$
Blue Lake
Harrison Slough
\ / Swan Lake
\
N \v
Trestle Area next to Route 97
Cataldo'
Slough
Laconia
NORTH
0 0.8
of 4th of July Marsh
West of Rose Lake
Porter
Slough
Oiling
Slough
I
amey
Strob
Hidden Marsh
Quarry Beach
RM145
blessing
Slough
Campbel
Slough
Medimont
MediclKe Lake
Medimont Boat Ramp
Dudley
Bull Run Peak Beach
East of Rose Lake
East of Blackrock Gulch Marsh
Wfiiteman s Sflough
Cataldo
*
Mission ^
Slough
Near East End of Killarney Lake
Beach near Canal to Killarney Lake
Hill Camping Area Medimont
Rainy Hill Fishing Area
Rainy Hill Picnic Area
Skeel Gulch Beach
South of Mission Flats
1.6 Miles
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.1-2
Lower Basin Recreation Areas
-------
Pick up mat 3 weeks later
Calculate dust loading rate (g/m2/day)
Collect census and identify homes with young children
(<6 years old) or pregnant women (door-to-door survey)
Sample yard and/or place dust mat
(dust mat monitoring on a yearly basis)
Vacuum mat within 3 working days from
date of collection
No further \ j'es
action for dust ~!
is dust loading rate <0.80 g/m2/day?
Send dust sample to
lab for testing
!s dust loading rate between
0.80 - 2.99 g/m2/day?
Is concentration
<1500 mg/kg?
Intervention
activities occur
No further
action for dust
No k
Dust loading rate is
r
>3.0 g/m2/day
-*s
w
Intervention
activities occur
Yes ^^-"Lead-basedpaim^\_
1=\kJentified as source?^--*5*
jTno
State lead-based paint
program initiated
Yard sample and other
information from intervention
activities will be used to
develop an action plan
\Wentified as source"'-^
j"No
State lead-based paint
program initiated
Yard sample and other
information from intervention
activities will be used to
develop an action plan
Reference: IDIQ (2001)
Wt
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.1-3
Flow Diagram of Dust Intervention Protocol
(based on dust mat monitoring)
-------
Ninemile Creek
Basin Boundary
Goal
Re-establish Fish
in Areas Currently
Devoid of Fish
(Downstream of
Interstate Mine)
is •**
? &
Ninemile
Creek Basin
Reconstruct Stream
Channel at Mouth
to Enable Fish Passage
UPPER »
BASIN
Bunker Hill
Box
Kellogg
Wood ana
Wallace
NORTH
o"Alene
Approximate Scale In Miles
Wa ace
Interstate Mine
Interstate I
Rex Mine and I
Cleanup of all
Metals-Adding Sources
Above Success Mine (See Figure 12.2-2)
Success Mine and Mill
Groundwater Treatment or
Removal of Tailings Pile
Potential Treatment of
Flow from East Fork
(Location to be determined
during remedial design)
oERA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-1
Ninemile Creek Cleanup Actions and Fisheries Status After Implementation of the Selected Remedy
-------
— SUNSET MINE
BUR051
LITTLE SUNSET MINE
BUR052
UNIDENTIFIED DISTURBANCE
GUELPH MINF BUR082
BUR081
AMBERGRIS MINE
BUR083
INTERSTATE-CALLAHA
MINE/ROCK DUMPS
BUR053
HERCULES NO. 2 (NINEMILE) .
BUR084 O
LACLEDE MINE
BUR077
/INTERSTATE-CALLAHAN LOWER ROCK DUMPS
/ BUR160
TAMARACK 400 LEVEL
UR170
CANYON CK IMPACTED
FLOODPLAIN
BUR140
TAMARACK MILLSITE
BUR173
TAMARACK UNNAMED ADJACENT ROCK DUMP
BUR205
INTERSTATE MILLSITE
BUF
MEDICO CLAIM UNNAMED ADIT
BUR197
REX N0.1
BUR139 V
TAMARACK UNNAMED ADIT
BUR172
REX NO.2 / SIXTEEN-TO-ONE Ml N
BUR054
TAMARACK NO. 4
BUR057
INDUS CLAIM UNNAMED ADIT
BUR196
TAMARACK NO.1 & N<^(CUSTER MINE)
BUR059
TAMARACK
ROCK DUMPS
BUR056
TAMARACK NO.5
BUR171
TAMARACK NO.3
BUR058
/ EF NINE
OSB056
MPACTED R PAR AN
SUCCESS MINE ROCK DUMP
OSB044
East Fork Ninemile Creek Basi
Kellogg
Osburn
Mu an
Wa ace
COLLECT CREEK WATER FOR TREATMENT
IF NEEDED TO ACHIEVE INTERIM BENCHMARKS
FOR MAINSTEM NINEMILE GREEK. LOCATION TO BE
DETERMINED DURING REMEDIAL DESIGN
Figure 12.2-2
East Fork Ninemile Creek
Cleanup Locations
LEGEND
Stream
~ City
l~~l Ninemile Creek Watershed Boundary
I I Source Area, Name, and Number
I—I No Action
I—I Remedial Action Selected in this ROD
I I Removal Action by Others
Idaho
Location Map
NOTE
1)
Base map coverages obtained
from the Coeur d'Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management.
SCALE 1:24,000
N
+
0.5 Miles
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
€irERftt
REGION 10
Doc Control: 4162500.07099.05.a
EPA No. 2.9
Generation 1
n:\Projects\Proposed Plan\
PP-NM Source Areas_01.apr
V: NM SEGS1-2 RA
E:SA
L: NM SEGS1-2
05/01/02
This map is based on Idaho
State Plane Coordinates West Zone,
North American Datum 1983.
Date of Plot: August 14, 2002
-------
Alternative 3
(R=0.20)
&
0
1
Selected Remedy With
Treatment Pond ( R=0.29)
Selected Remedy Without
Treatment Pond ( R=0.40)
AWQC ratio = 20
r>0.90
P-OM
P = 0.90
P = 0.50
P = 0.75
P = 0.25
AWQC ratio =10
r-OM
P
-------
CO
0
>
'-4-»
ro
c
0
-i—'
<
4—
o
0
O)
CO
-t—'
c
0
o
0
CL
100%
80%
60%
$59,000,000
2,100,000
460,000
/inn nnn
$36,000,000
(see note)
.300.000
40%
20%
1 Selected Remedy
1 Alternative 3
Cost
Total Volume of
Waste Addressed, cy
Zinc Load Reduction
lb/day
Regional Repository
Volume, cy
Note:
Cost including all contingent remedies. Estimated
cost without contingent remedies = $13,500,000.
oERV
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-4
Comparison of Selected Remedy to Alternative 3, Ninemile Creek
-------
F0/^ Coeur d'Alene River
Kingston
Pinehurst
Goal
Improve Salmonid
Populations
Action:
Improve Stream
Riparian Zone
Little Pittsburg
Nevada-Stewart Mine
Nabob Mine
and Millsite
Highland Surprise Mine and Millsite
Hilarity Mine
Upper/Lower Constitution
Pine
Creek Basin
UPPER\
BASIN
Bunker Hill
Box
Kellogg <3*-
¦South Fork
„1 OsburrT^;
Wallace
NORTH
0 1
Approximate Scale In Miles
oE PA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-5
Pine Creek Cleanup Actions and Fisheries Status After Implementation of Selected Remedy
-------
CO
0
>
'-4-»
ro
c
L_
0
o
0
O)
ro
-i—'
c
0
o
L_
0
CL
100%
80%
60%
40%
20%
0%
$41,000,000
1,000,000
84
120,000
$14,000,000
260,000
Selected Remedy
Alternative 3
Cost
Total Volume of
Waste Addressed, cy
Zinc Load Reduction
lb/day
Regional Repository
Volume, cy
AERA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-6
Comparison of Selected Remedy to Alternative 3, Pine Creek
-------
Overflow for
Peak Flows
Diversion _f
Structure
Floodplain
Limits
Base Flow
Piped to Pond
Floodplain 7s
Limits
Armored
Berm
Potential Groundwater
Passive Treatment
Treatment Pond
(2 or more cells)
Treated Effuent -
Plan View
50 year Flood Level
Liner
Treatment Pond Cross-Section
Sandfilter Layer
Reactive Medium
Geotextile
Gravel/Perf. Pipe
Drainage Layer
Treated Effluent
Note: This typical conceptual design was developed for feasibility-level
analysis of remedial alternatives. Actual designs would be developed during
remedial design based on the remedy selected in the ROD and site-specific
conditions and requirements.
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-7
Treatment Pond Conceptual Design
-------
Standard-Mammoth
~ Boundary of
Valley-fill Aquifer
Hecla-Star
Tailings Ponds
Sisters Mine
Woodland Park>^
Potential Treatment Pond Location
(5-10 acres; location to be determined during remedial design)
Goal:
Reduce estimated average
zinc load from 556 pounds
per day to approximately
234 pounds per day
Scale In Feet
NORTH
Canyon
Creek Basin
PPER \
BASIN
Bunker Hill
rBox
Kellogg
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.3
EPA No. 2.9
Figure 12-2-8
Lower Canyon Creek Cleanup Actions
-------
OOM PAUL NO. 1
BUR109
GORGE GULCH IMPACTED RIPARIAN
BUR146
AJAX NO
BUR107
HERCULES NO
BUR098
STANDARD-MAMMOTH LOADING AREA
BUR144
GERTIE MINE
urke BUR132
BURKE CONCENTRATOR
HECLA-STAR MINE & MILLSITE COMPLEX
BUR128
t
TAMARACK NO.7 (1200 LEVEL)
BUR067,
OMAHA MINE
BUR124
Mace
WEST STAR MINE
BUR114
HECLA-STAR
TAILINGS PONDS
Approximate Boundary of
Valley -Fill Aquifer
Canyon Creek Watershed
S STERarM NE
Potential Treatment Pond Location
(5 to 10 acres; location to be determined
during remedial design)
STANDARD-MAMMOTH
MILLSITE
Figure 12.2-9
Canyon Creek Cleanup Locations
LEGEND
Stream
City
l~~l Canyon Creek Watershed Boundary
I—i Approximate Location of
Valley Fill Aquifer
Idaho
Location Map
NOTE
1)
Base map coverages obtained
from the Coeur d'Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management.
SCALE 1:24,000
N
+
0.5 Miles
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
€irERftt
REGION 10
Doc Control: 4162500.07099.05.a
EPA No. 2.9
Generation 1
n:\Projects\Proposed Plan\
PP-NM Source Areas_01.apr
V: View 2
E:
L: Fig 12.2-4
This map is based on Idaho
State Plane Coordinates West Zone,
North American Datum 1983.
Date of Plot: May 01, 2002
-------
CO
0
>
'-4-»
ro
c
L_
0
o
0
O)
ro
-i—'
c
0
o
L_
0
CL
100%
80%
60%
40%
20%
0%
$150,000,000
442
140,000
$35
322
17,500
Selected Remedy
Alternative 3
Cost
Zinc Load Reduction, lb/day
Regional Repository
Volume, cy
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-10
Comparison of Selected Remedy to Alternative 3, Canyon Creek
-------
Figure 12.2-11
South Fork Cleanup Locations
LEGEND
Stream
A/ Road
10,000 CY
Elizabeth Park^
SPOT SEDIMENT REMOVALS
TOTALLING 15,000 CY
SPOT SEDIMENT REMOVALS
TOTALLING 15,000 CY
SEDIMENT REMOVAL
8,000 CY
Idaho
SPOT sediivjEnt removals
TOTALLING 15,OOjQCY
Silver Dollar
Mi lie
Osburn
SEDIMENT
REMOVAL
10,000 CY
Bureau of /
Mines Impoundment
Location Map
NOTE
Silverton
1) Base map coverages obtained
from the Coeur d'Alene Tribe,
URS Greiner Inc., CH2M HILL, and the
Bureau of Land Management.
SPOT SEDIMENT REMOVALS
TOTALLING 15,000 CY /
Woodland
Park
SJEDIMENT REMOVAL
2,OOOCY
Wallace
SCALE 1:70,000
Hercules
Millsite
1 Miles
RECORD OF DECISION
Thlo 11 lup I!, UdcUU ull IUcJIIu
n\Pro|ects\Proposed Plan\
PP-NM Source Areas_01 apr
Date of Plot May 2,3302
L Layout 1
-------
V ,
Bunn
/$¦
/$ * y
^ Woodland Park/
Golconda Minesite /
X"""" MUL001
Golconda Millsite
MUL002
Morning No
MUL019
Figure 12.2-12
Upper South Fork
Cleanup Locations
LEGEND
Stream
A/ I-90
~ City
£3 Source Area, Name,
and Number
Idaho
Location Map
NOTES
1) Base map coverages obtained
from the Coeur d' Alene Indian Tribe,
URS Greiner, CH2M Hill, and the BLM.
SCALE 1:66,000
2000 0 2000 4000 Feet
N
+
027-RI-CO-102Q
Coeur d1 Alene Basin RI/FS
RECORD OF DECISION
SEPA
REGION 10
Doc Control 4162500 07099 05 a
EPA No 2 9
n \Pro|ects\ROD\
areasjusfcdar apr
VIEW USFCDAR Soill
EXTENT West
LAYOUT USFCDAR Soil West
0510212002
This Map is based on Idaho
State Plane West Zone,
North American Datum 1983
DateofPlot August 14, 2002
-------
CO
0
CO
c
0
o
0
O)
ro
-i—'
c
0
o
0
CL
100%
80%
60%
$280,000,000
12,000,000
288
2,000,000
14.000
660,000
$17,000,000
40%
20%
Selected Remedy
Alternative 3
Cost
Total Volume of
Waste Addressed, cy
Zinc Load Reduction
lb/day
Regional Repository
Volume, cy
A ERA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-13
Comparison of Selected Remedy to Alternative 3, South Fork
-------
Pilot Removal of
Riverbed Sediment
Blue Lake
Hiiiisoii
Delta
Thompson Lake
Bare Marsh
Thompson Marsh
bs'nqston
Anderson Lake
Harrison Slough
- Harrison Marsh
^ X Harrison
•>.
%
%
<9
I aeon
NORTH
"tK
I
><&"
,o
\ \
-J V'.
CJ/
'J ,
V
i
x( "
Killamey Lake
\ \
Rose Lake
\\ \i*y Black Rut k
sioogi-
Cataldo
\ Sloiifif"
Porter
Slough
Bull Run Lake
Oiling /
Stouigh / Dudley
¦... 1/ /C^S
Q.
&
Swan Lske
Hidden Marsh
Blessing
Slough
^ Campbell Marsh
:[¦ /*> Mrjffit Slmirth
Strobl
Marsh
Lane Marsh
Splay AreaI
Sediment Trap
Medjmont
1
Whiteman's Slough
Mission
Sl0U9h.
Medicine Lake
Legend
Cave Lake
Cataldo
1J8 Miles
s—~1 Lake and wetland areas identified for cleanup
s in the selected remedy
Riverbank areas identified for removals and
stabilization
.J
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-14
Lower Basin Cleanup Actions
-------
3(o
Q wmm
ts
^ ° s
m a £3
O <2 ^
o ^ 2
73 cl
a >
o
o® °
""no
O w
CO =
o ^
^ =rl
CO
o
o
"O
fi>
o
to
.
Q. -»¦
*< CXI
$360,000,000
$1,500,000,000
1,379 yards
1,379 yards
580 lbs zinc/day
1-8.8.
1,200 lbs zinc/day
pi
&S> DO
|1§.
Q- «/> 3
jalo
3 ® ~ ^
S 3 § S
® & &
Q. ® 3 3
C/> Q.
PO hC
3|^
Sh n. §
ss ss «a
ST 2. 8?
2
ffgr
2. t/> w
SZ -O 3"
i o i
i & !¦
— 2-
d>
^W-nO
fsji
O. 3 "" m
»'S S?»
S»*8-
33 miles
49 miles
4,528 acres
10,454 acres
3.5 million cubic yards
(does not include mdte ri dl s effectively
addressed by interim measures in Canyon Creek)
21 million cubic yards
3.6 to 4.0 million cubic yards
29 million cubic yards
1.3 million cubic yards
20.6 million cubic yards
KEY
>
¦o
> «
¦o E
0) 0)
£ *
ft) 0)
* 1
* t
8 o
1 °
Note Quantities
do not include the
Bunker Hill Box
-------
Currently No Fish
Present in This Part of the
East Fork and Main Stem
Ninemile Creek
Smelterville
E hzabethiPark
Canyon Creek
>eJ
Canyon Creek
Fishery Not Addressed
in Selected Remed
Larson
SEM
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-16
Upper Basin Fisheries Status after Implementation of Selected Remedy
-------
No Box Loading
Box Loading Undiminished at End of Remediation
Fishery Tiers
250
500
750
15 -
O
a
< 10
M—
o
03
Q.
1,000
- 15
Undiminished Box
loading at end of remediation
represents a practical uppei
bound to the true AWQC ratio
Fishery Tier 1
Fishery Tier 2
Fishery Tier 3
Fishery Tier 4
Fishery Tier 5
Estimated Range
of AWQC ratio
1,000
Time, Years After Remediation
AERA
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-17
Expected Value of Zinc AWQC Ratio at Pinehurst: Selected Remedy
-------
No Box Loading
Box Loading Undiminished at End of Remediation
Fishery Tiers
250
500
750
1,000
O
a
O
03
a.
Undiminished Box
loading at end of remediation
represents a practical upper
bound to the true AWQC ratio
Fishery Tier 3
Fishery Tier 4
Estimated Range
of AWQC ratio
Fishery Tier 5
250 500 750
Time, Years After Remediation
1,000
AERA
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
Figure 12.2-18
Expected Value of Zinc AWQC Ratio at Harrison: Selected Remedy
-------
Murray Rd Bar Complex
(Depositional Area 9)
Barker Rd, N. Shore
(Common Use Area 204)
Replacement of shoreline
deposit and vegetation
Donkey Island Bar
(Depositional Area 24)
Island Complex Floodplain
and Banks
(Depositional Areas 5,6,7, and 8)
Replacement and capping
of impacted shoreline
Replacement and/or capping
of shoreline and bar
Replacement or capping and
bank bioengineering
Harvard Rd Access, N. Bank
(Common Use Area 202)
Upriver Dam Site
Plante Ferry Park Area
(Depositional Area 21)
Dredge or cap impacted
sediments behind dam
Replacement of impacted
gravel spawning beds
Replacement of impacted
shoreline sands
Post Falls
State Line
Spokane
Spokan« RlvCr
Coeur d'Alene Lake
Millwood
CL
Barker Rd, S. Shore
(Depositional Area 16)
CD
Replacement of impacted
shoreline area
Centennial Bridge/Islands, S. Shore
(Depositional Area 23)
Star Rd Gravel Bar Complex
(Common Use Area 201)
Replacement of impacted
shoreline sands
Flora Rd, S. Shore
(Common Use Area 205)
Replacement of shoreline
deposit and vegetation
Replacement of impacted
shoreline area
Scale In Miles
Doc. Control: 4162500.07099.05.a
EPA No. 2.9
REGION 10
027-RI-CO-102Q
Coeur d'Alene Basin RI/FS
RECORD OF DECISION
Figure 12.4-1
Spokane River Cleanup Actions
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-88
Table 12.0-1
Summary of Feasibility Study Alternatives Used and Estimated Costs of the Selected Remedy
Area
Seleck'd Ucnudv
I'lMimali'ri
Pivsenl
Worth
( apilal Cost
I'.slimalcd Pivscnl
Worth ol'OWr1
I'lMimali'd
Total Cost
Human health protection in
the community and residential
areas of the Upper Basin and
Lower Basin
Full remedy, including
Soil and house dust, including yards, infrastructures, repositories,
rights-of-way, commercial properties, and recreation areas.
Alternatives S4 (Information and Intervention and Partial Removal
and Barriers) and D3: (Information and Intervention, Vacuum Loan
Program/Dust Mats, Interior Source Removal, and Capping/More
Extensive Cleaning)
$91,000,000
$88,000,000
$2,100,000
$1,000,000
$920,000
$100,000
$92,000,000
including
$89,000,000b
$2,200,000
Drinking water: Alternative W6 (Public Information and Multiple
Alternative Sources)
$910,000
$0
$910,000
Aquatic food sources: Alternative F3 (Information and Intervention
and Monitoring)
Ecological protection in the
Upper Basin and Lower Basin
Approximately 30 years of prioritized actions
Upper Basin tributaries
Lower Basin river banks and bed
Lower Basin floodplains
$210,000,000
$74,000,000
$66,000,000
$74,000,000
$39,000,000
$27,000,000
$5,300,000
$7,200,000
$250,000,000,
including
$100,000,000°
$71,000,000
$81,000,000
Coeur d'Alene Lake
Not included in the Selected Remedy
Spokane River
Combination of elements of Spokane River Alternatives 3, 4, and 5
$9,300,000
$1,300,000
$ll,000,000d
Monitoring
Basin-wide monitoring
$0
$9,000,000
$9,000,000
Total Cost6
$310,000,000
$50,000,000
$360,000,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-89
Table 12.0-1 (Continued)
Summary of Feasibility Study Alternatives Used and Estimated Costs of the Selected Remedy
Note: Costs are rounded to two significant figures.
a O&M = operations and maintenance. Estimated costs are the present worth costs of 30 years of O&M calculated using a discount rate of 7%.
b Includes costs for residential soil (Table 12.1-11), street rights of way, commercial properties, and common areas (Table 12.1-12), 31 recreational areas in the
Lower Basin (Table 12.1-13), and house dust (Table 12.1-14).
0 Includes costs forNinemile Creek (Table 12.2-3), Pine Creek (Table 12.2-4), Canyon Creek (Table 12.2-5), and South Fork (Table 12.2-6). Includes actions at
mine and mill sites with human health concerns, as well as ecological concerns. Ninemile Creek costs include contingent actions, which have an estimated
total cost of $23,000,000 (including $18,000,000 capital cost and $4,500,000 O&M)
d Upper bound estimate for Spokane River. Lower bound total estimated cost = $4,500,000.
e Total costs are the sums of the bolded values, rounded to two significant figures.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-90
Table 12.1-1
Estimated Number of Residential Yards Exceeding Lead Cleanup Levels in the Upper
Basin and Lower Basin
MsliiiiiiU-d Tnliil
Msliniiilcd IVrccnCiiic of Y;irds
1-1 Mim;ilcd Number of Y;irds
Kcsidcnlhil
lAcmlinji Clciiniii) l.e\olh
r.xcmliiiii ( Iciiiiiii) Loi'l'
Aivsi
Yank'
700 m»/k»
1.000 m»/kti
700 m»/k»
1.000 nig/kg
Upper Basin
3,776
34
21
1,272
800
Lower Basin
821
13
13
107
107
Total
4,597
30
20
1,379
907
a Total numbers of yards estimated on the basis of the total yards for investigation areas reported in Table 3-18 of the
Human Health Risk Assessment (IDHW 2001a), except for Kingston and the Lower Basin. The total numbers of
yards in Kingston and the Lower Basin were reduced by 50 percent to account for upland yards not exposed to
potential contamination.
b The percentage of yards exceeding 1,000 mg/kg lead concentration was estimated on the basis of the percentage of
yards exceeding 1,000 mg/kg lead in Tables 6-1 la - 6-1 lj of the Human Health Risk Assessment; the percentage
of yards exceeding 700 mg/kg lead concentration was estimated on the basis of the average of the percentage of
homes remediated as listed in Tables 6-6 Id and 6-6 le of the Human Health Risk Assessment.
0 Estimated by multiplying the estimated total number of yards by the estimated percentage of yards exceeding the
corresponding lead concentration.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-91
Table 12.1-2
Summary of the Selected Remedy for Human Health Protection in Community and Residential Areas
Area
Remedial Action OI>jcc(i\e
Actions
Soil and House Dust
Reduce mechanical transportation of soil and
sediments containing unacceptable levels of
contaminants into residential areas and structures.
Reduce human exposure to soils, including
residential garden soils, and sediments that have
concentrations of contaminants of concern greater
than selected risk-based levels for soil. (As
described in Sections 7 and 12 of this ROD.)
Reduce human exposure to lead in house dust via
tracking from areas outside the home and air
pathways, exceeding health risk goals.
Alternative S4: Reduce soil concentrations using information and
intervention, community greening, partial removal, and barriers. Includes
partial removal and replacement of residential soils with lead concentrations
above 1,000 mg/kg (an estimated 907 residences), vegetative barriers to
control or limit migration of soils between 700 and 1000 mg/kg (an estimated
472 residences), and a combination of removals, barriers, and access
restrictions at commercial and undeveloped properties and recreation areas.
Alternative D3: Reduce individual house dust lead concentrations and
loadings using information and intervention, vacuum loan program/dust mats,
interior source removals and controls, if necessary. An estimated maximum
of 252 residences would require this additional cleaning. This would be
coordinated with paint abatement programs (see Figure 12.1-3).
Institutional Controls Manage contaminated material by protecting barriers
put in place through establishment of an institutional controls program, which
would include locally developed and enforced rules and regulations, disposal
areas, clean fill sources, control of contaminated source areas and other
considerations.
Drinking Water
Reduce ingestion by humans of groundwater or
surface water withdrawn or diverted from a private,
unregulated source, used as drinking water, and
containing contaminants of concern exceeding
drinking water standards and risk-based levels for
drinking water.
Alternative W6: Public information and multiple alternative sources.
Aquatic Food Sources
Reduce human exposure to unacceptable levels of
contaminants of concern via ingestion of aquatic
food sources (e.g., fish and water potatoes).
Alternative F3: Information and intervention and monitoring
l-lslimalcri Tolal Prcscnl Worth Cos! = sy2.000.000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-92
Table 12.1-3
1996 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
Number of
A\cr;iiii'
(icnimMrk'
IVrcenl of
IVrcenl of
Arc
Children
lilood l oud
M Oil n lilood
Children
( hildivn
(\ oil rs)
IVsk'd
iili/dl.
l.oiid fiii/dl.
> fili/dl.
> 15 ii^/d 1
1
8
6.6
5.2
25.0
12.5
2
10
5.7
4.6
10.0
10.0
3
8
4.8
3.7
12.5
0.0
4
10
3.4
3.0
0.0
0.0
5
11
6.5
5.5
27.3
9.1
6
11
4.3
3.5
9.1
0.0
All
58
5.2
4.2
13.8
5.2
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-93
Table 12.1-4
1997 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
Number of
A\cr;iiii'
(icnimMrk'
IVrcenl of
IVrcenl of
Arc
Children
lilood l oud
M Oil n lilood
Children
( hildivn
(\ oil rs)
IVsk'd
iili/dl.
l.oiid fiii/dl.
> fili/dl.
> 15 ii^/d 1
1
2
—
—
—
—
2
1
—
—
—
—
3
4
6.8
6.2
25.0
0.0
4
3
—
—
—
—
5
2
—
—
—
—
6
1
—
—
—
—
All
13
6.0
4.9
15.4
7.7
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-94
Table 12.1-5
1998 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
Number of
A\cr;iiii'
(icnimMrk'
IVrcenl of
IVrcenl of
Arc
Children
lilood l oud
M Oil n lilood
Children
( hildivn
(\ oil rs)
IVsk'd
iili/dl.
l.oiid fiii/dl.
> fili/dl.
> 15 ii^/d 1
1
9
8.7
8.0
33.3
11.1
2
9
6.6
5.5
11.1
11.1
3
10
7.1
5.7
20.0
10.0
4
18
5.5
4.8
11.1
0.0
5
13
5.0
4.6
0.0
0.0
6
11
6.3
5.4
7.1
7.1
All
70
6.3
5.4
12.92
5.7
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-95
Table 12.1-6
1999 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
Niimhor of
A\emtio
Coomolrio
Poroonl of
Poroonl of
Alio
Children
mood Lend
M on it Blood
Child ron
( hildren
(\ oil rs)
Tested
HB/ill.
l end fiii/dl.
> HI fiii/dl.
> I5,u»/dl.
1
21
6.6
6.0
14.3
0.0
2
26
9.0
7.1
34.6
19.2
3
30
6.8
5.5
20.0
10.0
4
26
6.5
4.8
19.2
11.5
5
36
5.3
4.5
5.6
2.8
6
23
4.5
3.9
4.3
0.0
All
162
6.4
5.2
16.0
7.4
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-96
Table 12.1-7
2000 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
Numhi-r of
A\emtio
Ceomelrie
Pereenl of
Pereenl of
Alii-
Children
mood l.e;id
M on it Blood
Children
( hildivn
(\oiirs)
Tested
HJi/dl.
l end fiii/dl.
> I0.iiii/dl.
> I5,u»/dl.
1
18
6.3
4.5
16.7
11.1
2
13
6.4
5.5
15.4
0
3
18
6.1
5.4
11.1
5.6
4
14
6.6
5.4
21.4
7.1
5
14
5.8
5.1
21.4
0
6
25
4.4
3.8
4.0
0
All
102
5.8
4.8
13.7
3.9
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-97
Table 12.1-8
2001 Blood Lead Levels in 1- to 6-Year-Old Children in the Affected Communities
in the Coeur d'Alene Basin, Excluding the Bunker Hill Box
Nil in her of
A\ ci'iiiio
(icnnu'iric
IVrcenl of
IVrcenl of
Alio
Children
mood l end
Moiin Blood
Children
Children
(u'sirs)
TcsU'd
uii/dl.
l.i'iid jiii/dl.
> l<> fiii/dl.
> 15 fiu/dl.
1
28
3.8
3.2
3.6
0
2
17
4.4
3.7
5.9
0
3
18
5.7
4.7
11.1
5.6
4
19
5.6
4.6
15.8
5.3
5
16
3.5
3.1
0
0
6
19
4.2
3.7
0
0
All
117
4.5
3.7
6.0
1.7
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-98
Table 12.1-9
Blood Lead Screening Results for the Basin by Year (Ages 0-6 Only)
Yi'iir
Number of
(hildivn
Tesk'd
A\crsi}»c Blood
Iv.id fiii/dl.
Pmvnl of
(hildivn
>10 n}»/cll.
Pmvnl of
(hildivn
> 15 fili/dl.
1996
58
5.2
14
5
1997
13
6.0
15
8
1998
70
6.3
13
6
1999
162
6.4
16
7
2000
102
5.8
14
4
2001
117
4.5
6
2
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-99
Table 12.1-10
Estimated Number of Residences With Drinking Water MCL Exceedances in the Upper Basin and Lower Basin
AiVii
No. <.r
Residences'1
Assumed Number
of Pri\iik\
I nrciiiihilcd
Sou rccs1'
l-'.sliuiiilcd l"rc(|iicnc\ ol°
MCI. l'.\cccd;inccsl
r.slim;ik'd Nunihil- of
Residences \\ i(h MCI.
r.\eeed;uiees
A\iiiliil>ilil\ of Siiil;il)lc Aquifer
Upper Basin
4,633
1,216
7%
91
None to medium
Lower Basin
1,642
800
10%
80
Medium to high
Notes:
" Based on site reconnaissance and demographic data from the human health risk assessment (IDHW 2001a).
b Assumes 100 percent of residences outside water district service boundaries have private, unregulated sources.
0 See Table 4-6 of the FS Part 2 (USEPA 2000c) for actual observed MCL exceedances. Lower Basin value applied to Kingston area because of small Kingston
data set.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-100
Table 12.1-11
Estimated Costs for Residential Soil
Tol;il Ysinls
Harriers/ Partial Kemo\als
\dminis-
Repository
Cost
Drainage
I parades
Keeon lam-
Total Present
Area
to Remediate
No. of Y;irds
Kstimaled Cost
Mohili/ation
Comingi'iicy1
(ration
ination
Worth Costh
Upper Basin
1,272
1,233
$18,578,816
$1,857,882
$9,093,509
$2,043,670
$2,031,597
$450,036
$2,552,828
$36,608,338
Lower Basin
107
102
$2,256,100
$225,610
$1,119,513
$248,171
$452,191
$518,903
$648,629
$5,469,116
Totals
1,379
1,335
$20,834,916
$2,083,492
$10,213,022
$2,291,841
$2,483,788
$968,938
$3,201,457
$42,077,454
Information and Intervention0
$1,358,000
Repository O&M Subtotal"1
$200,000
Total
$43,635,454
a Contingency includes costs for potential relocation, which are estimated assuming 5% of homes to be remediated will be relocated at an average cost of $50,000
per residence plus costs for mobilization, contingency, and administration.
bTotal estimated cost includes costs for 91 residences where soil cleanup has been completed, including 3 in Kingston area, 8 in Mullan, 22 in Osburn, 6 in
Silverton, 40 in Wallace, and 12 in Canyon Creek area.
Information and Intervention costs for residential areas are assumed to be equivalent to $1,358,000 of the total available funds for Information and Intervention
for the Basin ($3,580,000).
dAssumes five Upper Basin and one Lower Basin repositories will be operational for 10 years, with one Upper Basin and one Lower Basin repositories remaining
operational for 20 years following completion of cleanup actions. Costs for the repositories remaining operational for 10 years were assumed to be 10% of
capital + mobilization costs for year 1, 5% for years 2-5, and 2.5% for years 6 -10. Costs for continued operation were assumed to be 10% per year of the
capital + mobilization costs for each of the two repositories for 20 years followed by a 10-year operation and maintenance period with costs estimated as 10% of
capital + mobilization costs for year 21, 5% for years 22 - 25, and 2.5% for years 26 - 30.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-101
Table 12.1-12
Estimated Costs for Street Rights of Way, Commercial Properties, and Common Areas
Aivsi
Description
r.Miniiili'ri 1'resell (
\\ oi'lh Cost
Street Rights of Way
Assumes 1 foot depth of excavation and soil removal/replacement for $2/SF for approximately
8,000,000 SF of right-of-way (250 miles of road with 3-foot wide rights-of-way on both sides.
$16,000,000
Commercial Properties
Assumes 0.5 foot depth of excavation (1 foot depth next to sensitive receptors) and soil
removal/replacement from 150 properties at a cost of $115,000/property.
$17,000,000
Common Areas
Assumes 1 foot depth of excavation and soil removal/replacement from 15 properties at a cost
of $100,000/property.
$1,500,000
Information and intervention
Assume 6% of basin-wide Lead Health Intervention Program and 20% of basin-wide
institutional controls program.
$310,000
Total Estimated Cost
$35,000,000
Notes:
All costs rounded to two significant figures.
O&M costs are assumed to be minimal for street rights of way, commercial properties, and common areas.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-102
Table 12.1-13
Summary of Estimated Costs for House Dust
l-'.slimaled
l-'.slimaled
Presenl Worth
Presenl Worth
lislimaled
Kecrealion Area
( apilal (osl
oKKViM
Tolal Present Worth ( osl
Skeel Gulch Beach
$176,000
$16,500
$192,500
Old Mission State Park
$176,000
$16,500
$192,500
Old Mission State Park Boat Launch
$176,000
$16,500
$192,500
Beach in Mission Flats
$176,000
$16,500
$192,500
South of Mission Flats
$176,000
$16,500
$192,500
Mouth of 4th of July Marsh
$176,000
$16,500
$192,500
Bull Run Peak Beach
$176,000
$16,500
$192,500
Rose Lake Access Area (includes East of Rose
Lake and West of Rose Lake)
$254,800
$83,500
$338,300
East of Blackrock Gulch Marsh
$176,000
$16,500
$192,500
Beach Upstream from Quarry
$176,000
$16,500
$192,500
Quarry Beach
$176,000
$16,500
$192,500
RV Park across from Blackrock Gulch
$176,000
$16,500
$192,500
Blackrock Gulch Beach
$176,000
$16,500
$192,500
Beach below Ward Ridge
$176,000
$16,500
$192,500
Near East End of Killarney Lake
$176,000
$16,500
$192,500
Lane Beach
$176,000
$16,500
$192,500
Killarney Lake Boat Launch
$176,000
$16,500
$192,500
Beach near Canal to Killarney Lake
$176,000
$16,500
$192,500
RM 145
$176,000
$16,500
$192,500
Medimont (includes Boat Ramp, West Beach, and
Hill Camping Area)
$233,300
$76,000
$309,300
Rainy Hill (includes Fishing Area and Picnic
Area)
$233,300
$76,000
$309,300
West of Blue Lake
$176,000
$16,500
$192,500
RM 135 Long Beach/Springston
$176,000
$16,500
$192,500
Across River from Springston
$176,000
$16,500
$192,500
Springston Beach Site
$143,600
$47,000
$190,600
Thompson Lake
$217,300
$72,000
$289,300
Trestle Area next to Route 97
$176,000
$16,500
$192,500
Information and Intervention
$243,000
$0
$243,000
Total Estimated Present Worth Cost for
Recreation Areas
$5,200,000
$720,000
$5,900,000
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-103
Table 12.1-14
Summary of Estimated Costs for House Dust
1 dial
Residences
Direct
Mobili/ation
Admin.
Contingency
Total Present
Area
Residences
Affected
Cosf'1'
io";.
1
3ov;.
Worth Cost'
Information and Intervention and Vacuum Loan Program/Dust Mats
Lower Basin
1,642
575
$ 34,500
$ 3,450
$ 3,795
$11,385
$ 53,130
Upper Basin
4,633
3,180
$190,800
$19,080
$20,988
$62,964
$293,832
Subtotal
6,275
3,755
$225,300
$22,530
$24,783
$74,349
$346,962
Real-Time Monitoring Equipment
$ 7,400
Vacuum Loan Program
$ 16,000
35% of Lead Health Intervention Program costs. NPV« 15 vears. 7%.
$1,008,000
Subtotal, Information and Intervention and Vacuum Loan Program/Dust Mats
$1,380,000
Interior Source Removal/More Extensive Cleaning
Lower Basin
1,642
39
$ 276,900
$ 27,690
$ 30,459
$ 91,377
$ 426,426
Upper Basin
4,633
227
$1,611,700
$161,170
$177,287
$531,861
$2,482,018
Subtotal
6,275
266
$1,888,600
$188,860
$207,746
$623,238
$2,908,444
Subtotal, Interior Source Removal/More Extensive Cleaning
$2,908,444
Total Estimated Cost for House Dust
$4,288,000
11 Direct Cost for Information and Intervention and Vacuum Loan Program/Dust Mats = Number of residences affected times estimated cost for dust mats ($20)
and testing ($40) for a total of $60 per residence. Testing costs assume sampling once per year for 5 years, every other year to 10 years, and only 1/5 of the total
costs shared with other options.
b Direct Cost for Interior Source Removal/More Extensive Cleaning = The average of the average cost per house for HUD cleaning ($9,609) and the average cost
per house for commercial cleaning ($4,548) as described in the Interim Data Summary Report for Pre- and Post-Cleaning Results House Dust Pilot Project
2000, prepared for the Idaho State Department of Environmental Quality by TerraGraphics Environmental Engineering, Inc., May 2001.
0 Total Cost = Direct Cost (D) + Mobilization (M) + (D+M) times 10% + (D+M) times 30%.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-104
Table 12.1-15
Summary of Estimated Costs for Drinking Water
Inside oi* onlside
l-'.slim;iled no. of
l-'.sliniiiled present
llsliiiiiiled present
Ksliniiiled lol;il
Area
\\;i (or (lisirki
residences
worth e:ij)il
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-105
Table 12.1-16
Summary of Estimated Costs for Aquatic Food Sources
r.Miniiili'ri Presenl Worlli
r.sliniiileri 1'resell! Worlli
r.sliniiileri l oliil Present
Description
(
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-106
Table 12.2-1
Summary of the Selected Remedy for Ecological Protection in the Upper Basin and Lower Basin
Area
Benchmark
Actions
Upper Basin
Reduce potential for recontamination of downstream
remedies and reduce metals load to Coeur d'Alene Lake
and the Spokane River
Reduce metals and nutrient loads from groundwater
to the South Fork
Stabilize stream beds and banks and dumps subject to erosion,
implement runon/runoff controls, and construct sediment traps.
Includes actions in Canyon Creek, Ninemile Creek, Pine Creek,
and the South Fork.
Construct improvements to sewer and storm drain systems to
reduce infiltration of contaminated groundwater.
Estimated costs for stabilization actions are included under the watershed where the action would take place. Costs for sewer and storm drain improvements
would not be eligible for funding under CERCLA unless necessary to conduct or maintain remedy (the estimated cost for these improvements = $12,000,000)
Canyon Creek
Reduce metals toxicity to downstream aquatic receptors
Reduce dissolved metals load discharging to the South
Fork by at least 50%a
Reduce particulate lead and sediment loading during
high flows
Protect recreational users at mine and mill sites
Pilot and demonstration projects for treatment of creek water
and groundwater near the mouth (permeable reactive barrier
(PRB) or other technology, potentially including active
technology components). Implement water treatment or other
technology based on outcome of demonstration project.
Conduct stabilization of stream banks and dumps (e.g.,
Tamarack, Omaha, Standard-Mammoth Loading Area, Hercules
No. 5)
Address mine/mill sites with human health exposures (Standard-
Mammoth Mill, Sisters Mine, and Burke concentrator) using a
combination of access controls, capping and removals
Estimated Total Present Worth Cost = $35,000,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-107
Table 12.2-1 (Continued)
Summary of the Selected Remedy for Ecological Protection in the Upper Basin and Lower Basin
Area
lienchmark
Aclinns
Ninemile
Creek
East Fork
headwaters to
above Success
Improve conditions to allow natural reestablishment
of a salmon id fishery
Tier 2 to 3+ fishery (see fishery tier definitions at end of
table). Reestablish fishery in 1.7 miles of 13 miles of
streams in the Basin that are devoid of fish. Reduce
dissolved metals concentrations to less than 7 times
chronic AWQC with mitigation of mining impacts on
riverine areas. (AWQC are shown in Table 8.2-2)
Protect riverine and riparian receptors
Mitigate mining impacts on riparian areas along 1.7
miles of stream. Risks to riparian receptors will be
mitigated using removal and replacement with clean soil
or capping with clean soil to isolate contaminants and
reduce or eliminate exposure pathways.
Implementation of a remedy upstream of the Success based on
Alternative 3:
• All significant loading sources would be removed,
contained, or treated (all exceot lid land waste rock without
erosion or leaching potential and adits discharging metals at
concentrations
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-108
Table 12.2-1 (Continued)
Summary of the Selected Remedy for Ecological Protection in the Upper Basin and Lower Basin
Area
lienchmark
Aclinns
Ninemile
Creek
Mainstem
Ninemile Creek.
Improve conditions to allow natural reestablishment
of an adult salmonid fishery
Tier 1 fishery. Reduce dissolved metals concentrations
to less than 20 times acute AWQC. (AWQC are shown
in Table 8.2-2)
Protect recreational users at mine and mill sites
Benchmarks would be achieved through actions taken upstream
in East Fork.
Bioengineering actions may be implemented by other agencies
under other programs. Costs for these actions are not included
in the estimated costs for Ninemile Creek.
Remediate Day Rock mine and mill site using a combination of
access controls, capping and removals
Estimated Total Present Worth Cost = $13,500,000 to $36,000,000 (upper range includes additional actions at Success, Rex, and Interstate and treatment of
East Fork creek water)
Pine Creek
Improve conditions to allow natural increases in
salmonid populations and improve spawning and
rearing
Tier 3+ fishery.
Protect riverine and riparian receptors
Mitigate mining impacts on riparian areas at locations of
hot spot removal/capping. Risks to riparian receptors
will be mitigated using removal and replacement with
clean soil or capping with clean soil to isolate
contaminants and reduce or eliminate exposure
pathways.
Protect recreational users at mine and mill sites
including Upper and Lower Constitution Mine and Mill,
Highland Surprise Mine and Mill, Nevada Stewart
Mine, Hilarity Mine and Mill
Bank and bed stabilization and riparian zone revegetation, with
remaining hot spot removals, including Upper and Lower
Constitution Mine and Mill, Highland Surprise Mine and Mill,
Nevada Stewart Mine, Hilarity Mine and Mill, and Little
Pittsburg, Sidney on Denver Creek, and Nabob. Based on
results of monitoring, remedy may include treatment of Denver
Creek near its mouth to reduce metals load. Improve stream to
mitigate environment impacts from mining, including regrading
of stream reaches that go dry in the summer months.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-109
Table 12.2-1 (Continued)
Summary of the Selected Remedy for Ecological Protection in the Upper Basin and Lower Basin
Area
lienchmark
Aclinns
Estimated Total Present Worth Cost = $14,000,000
South Fork (above Elizabeth
Park)
Improve conditions to support a higher fish density
Tier 2+ to 3+ fishery at >0.1 fish/square meter
Initial protection of riverine and riparian receptors
Mitigate mining impacts on riparian areas at locations of
hot spot removal/capping. Risks to riparian receptors
will be mitigated using removal and replacement with
clean soil or capping with clean soil to isolate
Stabilize and bioengineer stream channel and banks to protect
riverine and riparian receptors, with associated hot-spot
removals in upper floodplain.
Address mine/mill sites with human health exposures (National
contaminants and reduce or eliminate exposure
Mill, Morning No. 6, Golconda, Hercules Mill, Coeur d'Alene
pathways.
Mill, USBM impoundment, and Silver Dollar Mine ) using a
combination of access controls, capping, and removals
Protect recreational users at mine and mill sites
Estimated Total Present Worth Cost = $16,000,000
South Fork (Elizabeth Park to
confluence including the Bunker
Hill Box)
Reduce metals loading to surface water
Hydrogeologic investigation: surface water and groundwater
monitoring and modeling.
Coordination with remedial activities within the Box, which
includes actions such as controlling loads to surface water from
the CIA area and upgrading the central treatment plant (CTP)b
Development of groundwater remedy alternatives.
Future actions in the Box are not part of this Selected Remedy.
b Remedial actions for Bunker Hill Box are addressed in the separate Records of Decision (RODs) for this area.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-110
Table 12.2-1 (Continued)
Summary of the Selected Remedy for Ecological Protection in the Upper Basin and Lower Basin
Area
lienchmark
Aclinns
Lower Basin Stream Banks and
Beds, including the Harrison
Delta (Riparian and Riverine)
Reduce particulate lead loading in the river
Reduce lead load entering into Lake Coeur d'Alene and
the Spokane River, with emphasis on peak discharge
events. Estimated reduction in high-flow load needed is
at least 50% to reduce year-round lead concentrations to
below chronic AWQC in the Spokane River.
Reduce soil toxicity for songbirds, small mammals,
and riparian plants
Mitigate risks to riparian receptors along 33.4 miles of
river by removing contaminated bank wedges from a
30-foot wide zone (122 acres). Remove contaminated
bank wedges and cap with clean topsoil to enhance
vegetation establishment and isolate contaminants from
receptors.
Reduce human exposure (recreational and
subsistence users)
Same as goals for soil and dust under communities and
residential areas
The goal is to implement complete removal of contaminated
bank wedges from highly-erosive areas.0 Where complete
removal is not feasible, partial removal may be followed by
capping with clean topsoil to enhance vegetation establishment
and isolate contaminants from receptors.
Stabilize banks and revegetate removal areas to protect riparian
zone ecological receptors and humans.
Construct and operate sediments traps at four splay areas where
the river overflows its banks during high flow conditions
(Frutchey's field, Black Rock Slough, Strobl Marsh, and
Medicine Lake) after implementing pilot study at one area.
Implement periodic removal of river bed sediments in Dudley
reach or other natural depositional areas identified during
remedial design.d
Estimated Total Present Worth Cost = $71,000,000
0 Areas identified as requiring aggressive actions. Costs based on 176,383 If (33.4 miles) with 2.3 cy/lf (approximately 30-feet wide).
d Assumes 500,000 cy initial removal and 200,000 cy after 5, 10, 15 and 20 years (total of 1.3 million cubic yards). It is EPA's intent to increase the removal of
riverbed sediments in the Dudley reach of the Coeur d'Alene River to up to 1,000,000 cy initial removal and 400,000 cy after 5, 10, 15, and 20 years for a total of
up to 2.6 million cubic yards. Based on current unit costs, this would increase the estimated total cost by approximately $26 million.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-111
Table 12.2-1 (Continued)
Summary of the Selected Remedy for Ecological Protection in the Upper Basin and Lower Basin
Area
lienchmark
Actions
Lower Basin Floodplain
Wetlands: Reduce sediment toxicity and waterfowl
mortality
Increase feeding area with lead concentration
<530 mg/kg by 1,169 acres (of a total of 5,829 wetland
acres with lead exceeding 530 mg/kg). Potentially
increase feeding area by an additional 1,500 acres
through conversion of agricultural land.
Lakes: Reduce sediment toxicity to diving ducks,
dabbling ducks, and warm- and cold-water fishes
Reduce lead concentration in whole brown bullhead fish
(as an indicator species) by remediating 1,859 of
5,979 acres of lake with lead exceeding 530 mg/kg.
Riparian: Reduce soil toxicity for riparian receptors
Reduce human exposure (recreational and
subsistence users)
Same as goals for soil and dust under communities and
residential areas.
Reduce exposure using a combination of removals, capping, and
soil amendments in areas of high waterfowl use, high lead, road
access, and relatively low recontamination potential. Human
health concerns would also be addressed in identified areas.
These areas are:
Lane Marsh (south of railroad ROW) (wetland: 213 acres)
Medicine Lake (wetland: 198 acres, lake: 230 acres)
Cave Lake (wetland: 190 acres, lake: 746 acres)
Bare Marsh (wetland: 165 acres)
Thompson Lake (wetland: 300 acres, lake: 256 acres);
Thompson Marsh (wetland 59 acres, lake: 122 acres)
Anderson Lake (wetland 44 acres, lake: 505 acres).
Identify agricultural and other areas (subject to landowner
approval and further sampling) with lower levels of lead for
cleanup to provide additional clean feeding areas (6 areas =
1500 acres).
Estimated Total Present Worth Cost = $81,000,000
Fishery Tier definitions:
Tier 0: No migrating or resident fish observed.
Tier 1: Presence of migrating fish only, no fish observed during resident fish surveys (expected to be achieved at concentrations below 20x acute AWQC).
Tier 2: Presence of resident salmonids (trout) of any species, sculpin absent (expected to be achieved at concentrations from 7x to lOx chronic AWQC).
Tier 3: Presence of 3 or more year classes of resident salmonids, including young of the year (YOY), sculpin absent (expected to be achieved at concentrations
between 3x and 7x chronic AWQC).
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-113
Table 12.2-2
Summary of Anticipated Fisheries Status After Implementation of the Selected Remedy
('iirmil Wilier (hemisln ;ni(l Ph\sic;il
Conditions
Wsiler ( hemisln :iikI Ph\sic;il ( ondhions Neeessiin In
Achie\e Benehniiirk
Ami
I'ishen Benehniiirk
z
5
0"
4*
C. _
^ -
•z
is
~
T
s _
— - Js
: l!
P'B
I
i_
? i!
H:
2
t
=
Z
2.
=
i
5
***
—
=.
-i
_ =
_ v
•=
z s M
z i =
I
ifi
t
=
Z
2.
=
Noles
East Fork
Ninemile Creek
above Success
Improve conditions to allow
natural reestablishment of an
adult salmonid fishery (Tier
3+)
50x
21 to 35
1,600
35
30 to 50
NR
<7x
10 to 15
>3,500
>60
30 to 50
3
• Rehabilitation of physical features needed to support fishery achieved
under the selected remedy.
• Marginal evidence for persistence of native trout populations at lOx
chronic AWQC. Probability of success increases if concentrations are
reduced below 7x chronic AWQC.
• Evidence of native trout populations present above the Interstate Mill
site as of 1995.
East Fork
Ninemile Creek
from confluence
with mainstem to
Success
Improve conditions to allow
establishment of a migratory
corridor for adult and
juvenile fish (Tier 1).
lOOx
21 to 35
1,600
35
30 to 50
NR
20x
None*
None*
None*
None*
None*
• No physical conditions issues are addressed by the remedy in this area of
the watershed. However, minimal improvements are necessary to
provide a migratory corridor.
• Other agencies may take additional actions under other programs that are
consistent with the overall goals of the selected remedy.
• Adult fish migration observed at high flow concentrations exceeding 20x
acute AWQC in Canyon Creek
• High flow bypass of any reactive barrier would need to allow fish
passage.
Mainstem
Ninemile Crk.
Improve conditions to allow
establishment of a migratory
corridor (Tier 1)
50x
15
1,600
15
NR
Oto 1
20x
None*
None*
None*
None*
None*
• No physical conditions issues are addressed under remedy. Summer
temperatures reduced somewhat by bioengineering actions above
Success.
• Physical constraints are limiting to establishment of a resident.
• Other agencies may take additional actions under other programs that are
consistent with the overall goals of the selected remedy.
East Fork Pine
Creek below
Douglass Creek
• Improve conditions to
allow natural increases
in salmonid populations
(Tier 3+ fishery).
• Improve spawning and
rearing habitat
10 to
20x
64
2,200
34
42
3*
<7x
18
>6,000
>60
40 to 50
3
• Existing physical conditions issues have been partially addressed by
BLM cleanup actions. Additional bioengineering with riparian
revegetation should remediate physical conditions
• Fishery is currently Tier 2, dominated by introduced brook trout.
• Existing densities are generally low (<0.05 fish/m2).
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-115
Table 12.2-2 (Continued)
Summary of Anticipated Fisheries Status After Implementation of the Selected Remedy
( urrenl Wilier (hemisln ;ind Ph\sic;il
Conditions
Wilier ( hemisln ;ind Ph\sic;il ( nndilinns Necesssin In
\ehie\e Benehniiirk
Noles
Aresi
l-ishen ISeiK'hniiii'k;|
i
Z
5
0"
t
-i
f *
•—
T
-
— S —
J 5 =
7 ^ r
I
>
¦='
H \
-1
2
t
=
a
£
—
i
*
5
i
- •=
•—
C -r —>
- - J:
111
fjb
V
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I
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Hi
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t
=
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—
Mainstem Pine
Creek
Same as above
lxto
3x
42
13,00
0
16
NR
3
<7x
NR
NR
>33
NR
3
• Floodplain removals include limited bioengineering. Some physical
conditions issues may not be fully addressed.
• Fishery is currently Tier 3+, dominated by introduced brook trout.
• Much of mainstem in Pinehurst is channelized which will limit fishery
productivity.
• Limiting stream temperatures were not observed during monitoring on
mainstem.
South Fork -
Improve conditions to
lOxto
34 to 64
1,500
16
<1
1
<7x
<50
>100,00
>30
>80
2
• Hot-spot removal with associated bank stabilization and riparian
Wallace to
support a higher fish density
20x
0
planting will address <10% of river length.
Elizabeth Park
(Tier 2+ to 3+ at >0.10
• Trout are present at Tier 2 to Tier 3 levels in the South Fork, but at low
fish/m2)
densities (<0.01 fish/m2).
• Physical conditions are limiting to fish populations throughout this area.
• AWQC ratio reductions will primarily be achieved by actions in
Ninemile and Canyon Creeks.
a Fishery Tier definitions:
Tier 0: No migrating or resident fish observed.
Tier 1: Presence of migrating fish only, no fish observed during resident fish surveys (concentrations below 20x acute AWQC).
Tier 2: Presence of resident salmonids (trout) of any species sculpin absent (Expected to be achieved of concentrations from 7x to lOx chronic AWQC).
Tier 3: Presence of 3 or more year classes of resident salmonids, including young of the year (YOY), sculpin absent (Expected to be achieved of concentrations between 3x and 7x chronic AWQC).
Tier 4: Presence of 3 or more year classes of resident salmonids, including YOY, and sculpin (Expected to be achieved of concentrations between lx and 3x chronic AWQC).
Tier 5: Presence of 5 salmonid age classes, including YOY, sculpin, and bull trout. Fauna dominated by native species at high densities (0.1 to >0.3 fish/m2) (least impacted watersheds with concentrations 150mm).
b AWQC ratios are the measured concentrations of cadmium and zinc rounded to multiples of chronic Ambient Water Quality Criteria (AWQC). Chronic AWQC thresholds are calculated based on a hardness of 70 mg/L as CaC03. For the definition of
fisheries tiers, AWQC are equal to the EPA-approved State of Idaho water quality standards for cadmium and zinc (see Tables 8.2-2 and 8.2-3). The concentration ranges are unaffected by the 2001 update to the cadmium criteria.
0 Width to depth ratio is the ratio of wetted channel width to wetted channel depth.
d Residual pool volume data has not been resolved due to discrepancies in the available data for assessment and reference areas.
"Percent shade measured as average percent channel canopy closure (IDEQ 1998).
fLarge woody debris defined as pieces at least 1 m long and 10cm diameter (IDEQ 1998).
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-117
Table 12.2-2 (Continued)
Summary of Anticipated Fisheries Status After Implementation of the Selected Remedy
g Temperature Rating definitions:
0: Temperatures exceed high adverse effects level threshold.
1: Temperatures exceed moderate adverse effects level threshold.
2: Temperatures exceed low adverse effects level threshold.
3: Temperatures do not exceed adverse level thresholds.
Source: Coeur d'Alene Basinwide Ecological Risk Assessment, Appendix K
Notes:
NR: Indicates data are available but discrepancies have not been resolved.
Indicates data are not available.
*: No area-specific actions for this parameter are believed necessary to achieve benchmark.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-119
Table 12.2-3
Summary of Estimated Costs for Ninemile Creek
SllilllV II)
Silt- Villlr
\\;i-lr l\ iii-
DcMTilllinll
<.)ll:illlil\
1 nil
1 nil Diml
( ;i|iil;il
( on|
Diml
( iipilnl
( on|
luilim-l
( :i|iil:il
( ll\|
Vl I'llMllI
\ nine III'
()\M
i:\SI l()l(kMM \llli: \li()\IM<< |;\\
ACCESSXM01
Access roads SegOl
Temporary Access Road
0.5
MI
$200,000
S100,000
$60,000
$0
ACCESSNM02
Access roads Seg02
Temporary Access Road
1.25
MI
$200,000
$250,000
$150,000
$0
BUR051
Sunset Mine
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
BUR051
Sunset Mine
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
BUR052
Little Sunset Mine
Waste Rock
Excavation
800
CY
$2.70
$2,160
$1,296
$0
BUR052
Little Sunset Mine
Waste Rock
Low Permeability Cap
0.16
AC
$151,000
$24,160
$14,496
$3,020
BUR053
Interstate Rock Dumps
Waste Rock
Low Permeability Cap
8.45
AC
$170,000
$1,436,500
$861,900
$323,213
BUR053
Interstate Rock Dumps
Waste Rock
Excavation
138,400
CY
$2.70
$373,680
$224,208
$0
BUR054
Rex No. 2
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
BUR054
Rex No. 2
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
BUR056
Tamarack Rock Dump
Waste Rock
Regrade/Consolidate/Revegetate
13.34
AC
$110,000
$1,467,400
$880,400
$183,425
BUR058
Tamarack No. 3
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
BUR058
Tamarack No. 3
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
BUR139
Rex No. 1
Waste Rock
Low Permeability Cap
1.31
AC
$151,000
$197,810
$118,686
$24,726
BUR140
Impacted riparian
Floodplain Sediments
Sediment Excavation
10,000
CY
$10
$100,000
$60,000
$0
BUR140
Impacted riparian
Floodplain Sediments
Regional Repository
10,000
CY
$16
$160,000
$96,000
$40,000
BUR 160
Interstate Lower Dump
Waste Rock
Low Permeability Cap
4.2
AC
$170,000
$714,000
$428,400
$160,650
BUR170
Tamarack 400 Level
Waste Rock
Low Permeability
0.95
AC
$151,000
$143,450
$86,070
$17,931
BUR170
Tamarack 400 Level
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
BUR170
Tamarack 400 Level
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
BUR171
Tamarack No. 5
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
BUR171
Tamarack No. 5
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
BUR171
Tamarack No. 5
Waste Rock
Low Permeability Cap
0.66
AC
$151,000
$99,660
$59,796
$12,458
BUR172
Tamarack Unnamed Adit
Waste Rock
Low Permeability Cap
0.43
AC
$151,000
$64,930
$38,958
$8,116
OSB056
Impacted riparian
Floodplain Sediments
Sediment Excavation
1,600
CY
$10
$16,000
$9,600
OSB056
Impacted riparian
Floodplain Sediments
Regional Repository
1,600
CY
$16
$25,600
$15,360
$6,400
OSB039
Day Rock
Upland Tailings
Excavation
11,000
CY
$2.70
$29,700
$17,820
$0
OSB039
Day Rock
Floodplain Sediments
Sediment Excavation
11,000
CY
$10
$110,000
$66,000
$0
OSB039
Day Rock
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
OSB039
Day Rock
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
OSB039
Day Rock
Floodplain Sediments
Regional Repository
11,000
CY
$16
$176,000
$105,600
$44,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-120
Table 12.2-3 (Continued)
Summary of Estimated Costs for Ninemile Creek
Sllllliv II)
Silt- Villlr
Wa-lr 1 \ |)C
Di'Miijilinii
<.)liaillil\
1 nil
1 nil Diml
( apilal
( on|
Diml
( apilal
( on|
Inilim'l
( 'apilal
( lis)
Vl I'llMllI
\ aluc ill'
O&M
OSB039
Day Rock
Upland Tailings
Local Repository Above Flood Level
11,000
CY
$9.70
$106,700
$64,020
$24,008
OSB039
Day Rock
Buildings & Structures
Decon Millsite
1
LS
$100,000
$100,000
$60,000
$5,000
LHAULNM02
Haul to local repository, Seg02
Haul to Local Repository
7,000
CY-MI
$0.89
$6,230
$3,738
$0
NM01-1
Headwaters to Interstate millsite reach
Current Deflector Sediment Traps
5
EA
$1,380
$6,900
$4,140
$40,020
NM01-1
Headwaters to Interstate millsite reach
Vegetative Bank Stabilization
4,011
LF
$36
$144,396
$86,638
$43,319
NM01-1
Headwaters to Interstate millsite reach
Bank Stabilization via Revetments
4,011
LF
$83
$332,913
$199,748
$99,874
NM01-1
Headwaters to Interstate millsite reach
Floodplain & Riparian Replanting
200,531
SF
$0.94
$188,499
$113,099
$32,987
NM01-1
Headwaters to Interstate millsite reach
Current Deflector
48
EA
$1,380
$66,240
$39,744
$19,872
NM02-1
Interstate millsite to Success reach
Current Deflector
45
EA
$1,380
$62,100
$37,260
$18,630
NM02-1
Interstate millsite to Success reach
Vegetative Bank Stabilization
3,777
LF
$36
$135,954
$81,572
$40,786
NM02-1
Interstate millsite to Success reach
Bank Stabilization via Revetments
3,777
LF
$83
$313,450
$188,070
$94,035
NM02-1
Interstate millsite to Success reach
Floodplain & Riparian Replanting
188,828
SF
$0.94
$177,498
$106,499
$31,062
NM02-1
Interstate millsite to Success reach
Off-Channel Hydrologic Feature
188,828
SY
$29
$5,032
$3,019
$881
NM02-1
Interstate millsite to Success reach
Current Deflector Sediment Traps
10
EA
1,380
$6,900
$4,100
$40,020
RHAULNMOl
Haul to Regional Repository, SegO 1
Haul to Regional Repository
81,200
CY-MI
$0.89
$72,268
$43,361
$0
Capital Cost S 12,000,000
O&M Cost S 1,500,000
Total Cost S 13,000,000
< <>\iim;i:\< ^ < osis
Rex
BUR055
Rex
Waste Rock
Low Permeability Cap
5
AC
$151,000
$755,000
$453,300
$94,375
BUR055
Rex
Upland Tailings
Tailings Impoundment Closure
6.5
AC
$170,000
$1,105,000
$663,000
$221,000
Capital $ 2,976,300
O&M $ 315,375
Total $ 3,291,675
Interstate Millsite
BUR055
Interstate Millsite
Floodplain Sediments
Regional Repository
5500
CY
$16
$88,000
$52,800
$22,000
BUR055
Interstate Millsite
Upland Tailings
Local Repository Above Flood Level
14000
CY
$9.70
$135,800
$81,400
$30,555
BUR055
Interstate Millsite
Floodplain Sediments
Sediment Excavation
5500
CY
$10
$55,000
$33,000
$0
Capital $ 446,080
O&M $ 52,555
Total $ 498,635
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-121
Table 12.2-3 (Continued)
Summary of Estimated Costs for Ninemile Creek
1 nil hired
Direct
Inilirecl
\el I'rcM'iil
SllillCC II)
Silt- Name
Wa-le l\pe
l)c>cripli<>ll
(.)ll:illlil\
1 nil
( apilal
( on|
( apilal
( on|
( apilal
( lis)
\ aluc ill'
O&M
Success
OSB044
Success
Floodplain Sediments
Regional Repository
10,000
CY
$16
$160,000
$96,000
$40,000
OSB044
Success
Upland Tailings
Excavation
360,000
CY
$2.70
$972,000
$583,200
$0
OSB044
Success
Waste Rock
Regrade/Consolidate/Revegetate
0.45
AC
$56,000
$25,200
$15,120
$3,150
OSB044
Success
Upland Tailings
Regional Repository
360,000
CY
$16
$5,760,000
$3,456,000
$1,440,000
OSB044
Success
Floodplain Sediments
Sediment Excavation
10,000
CY
$10
$100,000
$60,000
$0
Capital
O&M
$ 11,227,520
$ 1,483,150
Total
$ 12,710,670
liust lurk Ninemile Treatment Pond (See Note 1)
Ninemile Treatment Pond (10 cfs)
Reagent
1,603
TON
$600
$961,696
$577,018
$1,906,005
Ninemile Treatment Pond (10 cfs)
Other Construction and Monitoring
1
LS
$1,123,089
$1,123,089
$673,853
$762,402
Capital
O&M
$ 3,335,656
$ 2,668,407
Total
$ 6,004,063
Total Contingency Capital Cost
Total Contingency O&M Cost
Total Contingency Cost
$18,000,000
$ 4,500,000
$23,000,000
TOTAL CAPITAL COST
$30,000,000
TOTAL O&M COST
$ 6,000,000
TOTAL COST
$36,000,000
Note 1: Estimated costs for treatment pond are based on the assumption that 70% of the upstream metal load in Ninemile Creek is removed by source-specific remedial actions.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-122
Table 12.2-4
Summary of Estimated Costs for Pine Creek
1 nil
1 >iiril
Diml
Inilim'l
Nil
I'lr-rlll
Sllillir II)
siu- \iinn-
WiMr l\|ir
l>f>iTi|ili
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-123
Table 12.2-4 (Continued)
Summary of Estimated Costs for Pine Creek
SllilllV II)
siu- \iinn-
WiMf l\|lf
l>c>ci'i|iliiiii
(.)ll:illlil\
1 nil
1 nil
l)im'l
( :i|iil:il
( lis|
Diml
( ;l|)il;ll
( on|
Imliml
( :i|iil:il
( On|
Nil
I'lr-rnl
\ illllc III'
OWI
Capital $ 4,800,000
O&M $ 1,000,000
Total $ 5,800,000
Ecological Protection at Mine and Mill Sites
MAS015
Little Pittsburg Lower Mine
Upland Waste Rock
Local Repository Above Flood Level
1,000
CY
$9.70
$9,700
$5,820
$2,183
MAS015
Little Pittsburg Lower Mine
Upland Waste Rock
Excavation
1,000
CY
$2.70
$2,700
$1,620
$0
MAS015
Little Pittsburg Lower Mine
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
MAS015
Little Pittsburg Lower Mine
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
MAS016
Little Pittsburg Lower Mine
Adit Drainage
Permeable Reactive Trench
1
LS
$4,400
$4,400
$2,640
$26,400
MAS016
Little Pittsburg Lower Mine
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
MAS016
Little Pittsburg Lower Mine
Upland Waste Rock
Local Repository Above Flood Level
23,280
CY
$9.70
$225,816
$135,490
$50,809
MAS016
Little Pittsburg Lower Mine
Upland Waste Rock
Excavation
23,280
CY
$2.70
$62,856
$37,714
$0
MAS017
Sidney (Denver)
Upland Waste Rock
Excavation
62,640
CY
$2.70
$169,128
$101,477
$0
MAS017
Sidney (Denver)
Upland Waste Rock
Local Repository Above Flood Level
62,640
CY
$9.70
$607,608
$364,565
$136,712
MAS020
Sidney Mine/Millsite
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
MAS020
Sidney Mine/Millsite
Adit Drainage
Permeable Reactive Trench
4.2
LB/DAY
$13,903
$58,838
$55,421
$147,790
Flaul to Local Repository
96,095
CY-MI
$0.89
$85,525
$51,315
$0
Capital $ 2,000,000
O&M $ 400,000
Total $ 2,400,000
Bioengineering
PC03-1
E.Fork/W.Fork conf to unnamed
Bank Stabilization via Revetments
2,032
LF
$83
$168,656
$101,194
$50,597
PC03-2
unnamed to unnamed
Bank Stabilization via Revetments
1,649
LF
$83
$136,867
$82,120
$41,060
PC03-3
unnamed to Little Pine Creek
Bank Stabilization via Revetments
1,000
LF
$83
$83,000
$49,800
$24,900
PC03-1
E.Fork/W.Fork conf to unnamed
Floodplain and Riparian Replanting
232,739
SF
$0.94
$218,775
$131,265
$38,286
PC03-2
unnamed to unnamed
Floodplain and Riparian Replanting
181,335
SF
$0.94
$170,455
$102,273
$29,830
PC03-3
unnamed to Little Pine Creek
Floodplain and Riparian Replanting
284,463
SF
$0.94
$267,395
$160,437
$46,794
PC03-1
E.Fork/W.Fork conf to unnamed
Vegetative Bank Stabilization
2,032
LF
$36
$73,152
$43,891
$21,946
PC03-2
unnamed to unnamed
Vegetative Bank Stabilization
1,649
LF
$36
$59,364
$35,618
$17,809
PC03-3
unnamed to Little Pine Creek
Vegetative Bank Stabilization
1,000
LF
$36
$36,000
$21,600
$10,800
PC01-3
Constitution to unnamed
Floodplain and Riparian Replanting
137,280
SF
$0.94
$129,043
$77,426
$22,583
PC01-4
unnamed to Douglas
Floodplain and Riparian Replanting
203,280
SF
$0.94
$191,083
$114,650
$33,440
PC01-5
Douglas to Dry
Floodplain and Riparian Replanting
1,24,080
SF
$0.94
$116,635
$69,981
$20,411
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-124
Table 12.2-4 (Continued)
Summary of Estimated Costs for Pine Creek
Sllillir II)
siu- \iinn-
WiMf l\|lf
DiMiipliiiii
(.)ll:illlil\
1 nil
1 nil
1 >iiril
( :i|iil:il
( lis|
Diml
( ;l|)il;ll
( on|
Inilim'l
( :i|iil:il
( On|
Nil
1 'iVM'lll
\ aliir ill'
OWI
PCO 1-6
Dry lo Blue Eagle
Floodplain and Riparian Replanting
47,520
SF
SO. 94
S44,669
S26,801
$7,817
PCO1-7
Blue Eagle to Highland
Floodplain and Riparian Replanting
126,720
SF
$0.94
$119,117
$71,470
$20,845
PCO1-8
Highland to Denver
Floodplain and Riparian Replanting
166,320
SF
$0.94
$156,341
$93,804
$27,360
PCO 1-9
Denver to Hunter
Floodplain and Riparian Replanting
163,680
SF
$0.94
$153,859
$92,316
$26,925
PC01-10
Hunter to unnamed
Floodplain and Riparian Replanting
36,960
SF
$0.94
$34,742
$20,845
$6,080
PC01-11
unnamed to Nabob
Floodplain and Riparian Replanting
47,520
SF
$0.94
$44,669
$26,801
$7,817
PC01-12
Nabob to West Fork
Floodplain and Riparian Replanting
343,200
SF
$0.94
$322,608
$193,565
$56,456
Bioengineering (Continued)
PCO 1-3
Constitution to unnamed
Current Deflector
37
EA
$1,380
$51,060
$30,636
$15,318
PCO 1-4
unnamed to Douglas
Current Deflector
54
EA
$1,380
$74,520
$44,712
$22,356
PCO 1-5
Douglas to Dry
Current Deflector
33
EA
$1,380
$45,540
$27,324
$13,662
PCO 1-6
Dry to Blue Eagle
Current Deflector
13
EA
$1,380
$17,940
$10,764
$5,382
PCO 1-7
Blue Eagle to Highland
Current Deflector
34
EA
$1,380
$46,920
$28,152
$14,076
PCO 1-8
Highland to Denver
Current Deflector
44
EA
$1,380
$60,720
$36,432
$18,216
PCO 1-9
Denver to Hunter
Current Deflector
44
EA
$1,380
$60,720
$36,432
$18,216
PC01-10
Hunter to unnamed
Current Deflector
10
EA
$1,380
$13,800
$8,280
$4,140
PC01-11
unnamed to Nabob
Current Deflector
13
EA
$1,380
$17,940
$10,764
$5,382
PC01-12
Nabob to West Fork
Current Deflector
92
EA
$1,380
$126,960
$76,176
$38,088
Capital $ 4,900,000
O&M $ 700,000
Total $ 5.600,000
Capital S 12,000,000
O&M S 2,100,000
Total S 14,100,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-125
Table 12.2-5
Summary of Estimated Costs for Canyon Creek
Si hi n i- II)
Sile Name
Wask- T\ pi-
Di-siripiiiiii
Qiianlil\
I nil
I nil
l)iri-ii
('apilal
( IISl
Din-il
(apilal
C iisi
liidiri-i'l
Capital
( IISl
Nil
Pivsi-nl
Yalui- ill'
O&M
Human Health at Mine and Mill Sites
WAL039
SM Mill
Upland Tailings
Excavate/Dispose in Regional Landfill
12,500
CY
$18.50
$231,250
$138,750
$0
WAL039
SM Mill
Upland Tailings
General Grading
10,000
CY
$2
$20,000
$12,000
$2,500
WAL039
SM Mill
Upland Tailings
Cap - General
3,500
CY
$16.50
$57,750
$34,650
$7,219
WAL039
SM Mill
Upland Tailings
Upland Revegetation
2
AC
$5,000
$10,000
$6,000
$1,250
WAL039
SM Mill
Floodplain Sediments
Wetland Vegetation
3
AC
$11,000
$33,000
$19,800
$5,775
WAL039
SM Mill
Floodplain Sediments
Upland Revegetation
1
AC
$5,000
$5,000
$3,000
$625
WAL039
SM Mill
Floodplain Sediments
Bioengineering Streambanks
2,300
LF
$40
$92,000
$55,200
$27,600
WAL008
Sisters
Upland Waste Rock
Excavate/Dispose in Regional Landfill
5,000
CY
$18.50
$92,500
$55,500
$0
WAL008
Sisters
Upland Waste Rock
Upland Revegetation
0.6
AC
$5,000
$3,000
$1,800
$375
WAL008
Sisters
Upland Waste Rock
General Grading
2,000
CY
$2
$4,000
$2,400
$500
BUR128
Burke Concentrator
Buildings & Structures
No Actions identified
$0
$0
$0
Capital $ 880,000
O&M $ 50,000
Total $ 930,000
Dump and Bank Stabilization
BUR067
Tamarack 7YWRP
Upland Waste Rock
Bioengineering Steambanks
1,000
LF
$40
$40,000
$24,000
$12,000
BUR067
Tamarack 7YWRP
Upland Waste Rock
General Grading
35,000
CY
$2
$70,000
$42,000
$0
BUR067
Tamarack 7YWRP
Upland Waste Rock
Upland Vegetation
14
AC
$5,000
$70,000
$42,000
$8,750
BUR098
Hercules No. 5
Upland Waste Rock
Bioengineering Steambanks
500
LF
$40
$20,000
$12,000
$6,000
BUR098
Hercules No. 5
Upland Waste Rock
General Grading
12,000
CY
$2
$24,000
$14,400
$0
BUR098
Hercules No. 5
Upland Waste Rock
Upland Vegetation
3
AC
$5,000
$15,000
$9,000
$1,875
BUR107
AjaxNo. 3\WRP
Upland Waste Rock
Bioengineering Steambanks
500
LF
$40
$20,000
$12,000
$6,000
BUR107
AjaxNo. 3\WRP
Upland Waste Rock
General Grading
12,000
CY
$2
$24,000
$14,400
$0
BUR107
AjaxNo. 3 \WRP
Upland Waste Rock
Upland Vegetation
2.4
AC
$5,000
$12,000
$7,200
$1,500
BUR109
Oom PaulYWRP
Upland Waste Rock
Bioengineering Steambanks
300
LF
$40
$12,000
$7,200
$3,600
BUR109
Oom PaulYWRP
Upland Waste Rock
General Grading
5,000
CY
$2
$10,000
$6,000
$0
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-126
Table 12.2-5 (Continued)
Summary of Estimated Costs for Canyon Creek
Shu ni- II)
Sik- Name
Wask-T\pi-
IK'siripiiiiii
Quanlil\
I nil
I nil
Diivii
Capital
Cosi
Diivii
Capital
Ciisl
In diivii
Capital
Chsi
Nil
PlVSl'Ill
Yalui- ill'
(WsM
Dump and Bank Stabilization (Continued)
BUR109
Oom PaulYWRP
Upland Waste Rock
Upland Vegetation
1
AC
$5,000
$5,000
$3,000
$625
BUR114
West StarYWRP
Upland Waste Rock
Bioengineering Steambanks
300
LF
$40
$12,000
$7,200
$3,600
BUR114
West Star\WRP
Upland Waste Rock
General Grading
300
CY
$2
$600
$360
$0
BUR114
West Star\WRP
Upland Waste Rock
Upland Vegetation
1
AC
$5,000
$5,000
$3,000
$625
BUR 124
OmahaVFP
Floodplain Sediments
Bioengineering Steambanks
1,770
LF
$40
$70,800
$42,480
$21,240
BUR 124
OmahaVFP
Floodplain Sediments
General Grading
1,000
CY
$2
$2,000
$1,200
$0
BUR 124
OmahaVFP
Floodplain Sediments
Upland Vegetation
0.6
AC
$5,000
$3,000
$1,800
$375
BUR128
Hecla Star
Upland Waste Rock
Bioengineering Steambanks
1,000
LF
$40
$40,000
$24,000
$12,000
BUR128
Hecla Star
Upland Waste Rock
General Grading
1,000
CY
$2
$2,000
$1,200
$0
BUR128
Hecla Star
Upland Waste Rock
Upland Vegetation
1
AC
$5,000
$5,000
$3,000
$625
BUR132
GertieYWRP
Upland Waste Rock
Bioengineering Steambanks
300
LF
$40
$12,000
$7,200
$3,600
BUR132
Gertie\WRP
Upland Waste Rock
General Grading
8,000
CY
$2
$16,000
$9,600
$0
BUR 144
Standard MammothYWRP
Upland Waste Rock
Bioengineering Steambanks
300
LF
$40
$12,000
$7,200
$3,600
BUR 144
Standard Mammoth\WRP
Upland Waste Rock
General Grading
6,000
CY
$2
$12,000
$7,200
$0
BUR 144
Standard Mammoth\WRP
Upland Waste Rock
Upland Vegetation
2.5
AC
$5,000
$12,500
$7,500
$1,563
BUR146
Gorge Gulch/FP
Floodplain Sediments
Bioengineering Steambanks
1,500
LF
$40
$60,000
$36,000
$18,000
BUR146
Gorge Gulch/FP
Floodplain Sediments
General Grading
CY
$2
$0
$0
$0
BUR146
Gorge Gulch/FP
Floodplain Sediments
Upland Vegetation
2
AC
$5,000
$10,000
$6,000
$1,250
WAL039
Strd MammothVFP
Floodplain Sediments
Bioengineering Steambanks
2,300
LF
$40
$92,000
$55,200
$27,600
WAL039
Strd MammothVFP
Floodplain Sediments
General Grading
1,000
CY
$2
$20,000
$12,000
$0
WAL039
Strd MammothVFP
Floodplain Sediments
Upland Vegetation
3
AC
$5,000
$15,000
$9,000
$1,875
Capital $ 1,160,000
O&M $ 140,000
Total $ 1,300,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-127
Table 12.2-5 (Continued)
Summary of Estimated Costs for Canyon Creek
I nil
Nil
Direil
Direil
Indiivil
Pivsenl
Capital
Capital
Capital
Value ill'
Shu ni- II)
Sile Name
Wasle T\pe
Desiripliiin
Quanlil\
I nil
Cosi
Ciisl
Ciisl
(WsM
Treatment Pond
Canyon Creek Treatment
Reagent
6,411
TON
$600
$3,846,784
$2,308,071
$10,478,910
Pond (60 cfs)
Canyon Creek Treatment
Pond (60 cfs)
Construction/Monitoring
LS
$5,511,929
$5,511,929
$3,307,157
$7,223,034
Capital
O&M
$15,000,000
$18,000,000
Total
$33,000,000
TOTAL CAPITAL COST
$17,000,000
TOTAL O&M COST
$18,000,000
TOTAL COST
$35,000,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-128
Table 12.2-6
Summary of Estimated Costs for South Fork
Shu ni- II)
Sili- Name
Waste T\pe
Description
Quanlil\
I nil
I nil
Direct
Capital
Cost
Direct
Capital
Cost
Indirect
Capital
Cost
Vl
Present
Value ill'
(WsM
South Fork Human Health
WAL037
Hercles
Upland Tailings
Excavation
12,000
CY
$3
$32,400
$19,440
$0
WAL03
Hercles
Upland Tailings
Local Repository Above Flood Level
12,000
CY
$10
$116,400
$69,840
$26,190
KLE062
USBM Imp.
Floodplain Sediments
Sediment Excavation
26,000
CY
$10
$260,000
$156,000
$0
KLE062
USBM Imp
Floodplain Sediments
Regional Repository
26,000
CY
$16
$416,000
$249,600
$104,000
KLE034
Silver Dollar
Floodplain Waste Rock
Excavation
4,400
CY
$2.70
$11,880
$7,128
$0
KLE034
Silver Dollar
Floodplain Waste Rock
Low Permeability Cap
2.29
AC
$151,000
$345,790
$207,474
$43,224
Capital $ 1,900,000
O&M $ 170,000
Total $ 2,070,000
South Fork Hot Spot
WAL004
Floodplain Sediments
Excavate Sediments
17,000
CY
$10.00
$170,000
$102,000
$0
WAL004
Floodplain Sediments
Regional Repository
17,000
CY
$16.00
$272,000
$163,200
$68,000
WAL004
Floodplain Sediments
Hauling
34,000
CY-Mt
$0.89
$30,260
$18,156
$0
OSB120
Floodplain Sediments
Excavate Sediments
33,000
CY
$10.00
$330,000
$198,000
$0
OSB120
Floodplain Sediments
Regional Repository
33,000
CY
$16.00
$528,000
$316,800
$132,000
OSB120
Floodplain Sediments
Hauling
66,000
CY-Mt
$0.89
$58,740
$35,244
$0
OSB065
Floodplain Sediments
Excavate Sediments
42,000
CY
$10.00
$420,000
$252,000
$0
OSB065
Floodplain Sediments
Regional Repository
42,000
CY
$16.00
$672,000
$403,200
$168,000
OSB065
Floodplain Sediments
Hauling
84,000
CY-Mt
$0.89
$74,760
$44,856
$0
KLE049
Floodplain Sediments
Excavate Sediments
10,000
CY
$10.00
$100,000
$60,000
$0
KLE049
Floodplain Sediments
Regional Repository
10,000
CY
$16.00
$160,000
$96,000
$40,000
KLE049
Floodplain Sediments
Hauling
20,000
CY-Mt
$0.89
$17,800
$10,680
$0
Capital $ 4,500,000
O&M $ 410,000
Total $ 4,910,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-129
Table 12.2-6 (Continued)
Summary of Estimated Costs for South Fork
Shu ni- II)
Sile Name
Waste T\pe
Description
Quanlil\
I nil
I nil
Direii
Capital
Cusi
Direii
Capital
( IISl
Inriireii
Capital
(usl
\el
Present
Value ill'
O&M
Upper South Fork Human Health
MUL002
Golconda
Upland Tailings
Excavation
23,000
CY
$2.70
$62,100
$37,260
$0
MUL002
Golconda
Upland Tailings
Local Repository Above Flood Level
23,000
CY
$9.70
$223,100
$133,860
$50,198
MUL001
Golconda
Floodplain Waste Rock
Excavation
75,360
CY
$2.70
$203,472
$122,083
$0
MUL001
Golconda
Floodplain Waste Rock
Local Repository Above Flood Level
75,360
CY
$9.70
$730,992
$438,595
$164,473
MUL019
Morning No. 6
Floodplain Tailings
Excavation
85,000
CY
$2.70
$229,500
$137,700
$0
MUL019
Morning No. 6
Floodplain Tailings
Local Repository Above Flood Level
85,000
CY
$9.70
$824,500
$494,700
$185,513
MUL019
Morning No. 6
Floodplain Waste Rock
Excavation
67,260
CY
$2.70
$181,602
$108,961
$0
MUL019
Morning No. 6
Floodplain Waste Rock
Low Permeability Cap
17.65
AC
$151,000
$2,665,150
$1,599,090
$333,144
MUL019
Morning No. 6
Adit Drainage
Permeable Reactive Trench
33.5
CY
$440
$14,740
$8,844
$88,441
MUL019
Morning No. 6
Adit Drainage
Adit Drainage Collection
1
LS
$6,200
$6,200
$3,720
$1,085
MUL019
Morning No. 6
Buildings & Structures
Decon Millsite
1
LS
$100,000
$100,000
$60,000
$5,000
MUL131
National Mill
Upland Tailings
Excavation
6,600
CY
$2.70
$17,820
$10,692
$0
MUL131
National Mill
Upland Tailings
Local Repository Above Flood Level
6,600
CY
$9.70
$64,020
$38,412
$14,405
MUL132
National Mill Adj. Tailings
Upland Tailings
Excavation
1,800
CY
$2.70
$4,860
$2,916
$0
MUL132
National Mill Adj. Tailings
Upland Tailings
Local Repository Above Flood Level
1,800
CY
$9.70
$17,460
$10,476
$3,929
Capital $ 8,600,000
O&M $ 850,000
Total $ 9,450,000
TOTAL O&M COST $1,400,000
TOTAL CAPITAL COST $15,000,000
TOTAL COST $16,000,000
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-130
Table 12.2-7
Summary of Estimated Costs for Lead in Floodplains
Sili- Vimi-
\\;isk- l \ pi-
1(1)
Di-siiipliim
Qll;illlil>
I nil
I nil
Din-ii
(;ipil:il
( IISl
Din-il
(;ipil;il
C iisl
Indiri-i'l
(;ipil;il
( IISl
Nil
Pivsi-ni
Yiilui- ill'
OiKM
Lane Marsh (south of UPRR)
Wetland Pond
C01
Excavation
48,000
CY
$2.70
$ 129 600
$77,760
$0
Lane Marsh (south of UPRR)
Wetland Pond
HAUL-1
Haul 10 miles one-way
48,000
CY
$8.90
$427,200
$256,320
$0
Lane Marsh (south of UPRR)
Wetland Pond
C08
Regional Repository
48,000
CY
$10.31
$494,880
$296,928
$98,976
Lane Marsh (south of UPRR)
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Lane Marsh (south of UPRR)
General
LB-07a
Construct New Levee
14,000
LF
$151
$2,114,000
$1,268,400
$422,800
Lane Marsh (south of UPRR)
Wetland Sediment
LB-08
Place Sand Cap
340,000
CY
$8.02
$2,726,800
$1,636,080
$545,360
Medicine Lake
Wetland Pond
C01
Excavation
32,000
CY
$2.70
$86,400
$51,840
$0
Medicine Lake
Wetland Pond
HAUL-1
Haul 10 miles one-way
32,000
CY
$8.90
$284,800
$170,880
$0
Medicine Lake
Wetland Pond
C08
Regional Repository
32,000
CY
$10.31
$329,920
$197,952
$65,984
Medicine Lake
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Medicine Lake
General
LB-07a
Construct New Levee
9,000
LF
$151
$1,359,000
$815,400
$271,800
Medicine Lake
Wetland Sediment
LB-08
Place Sand Cap
320,000
CY
$8.02
$2,566,400
$1,539,840
$513,280
Medicine Lake
Lake Sediment
LB-04b
Dredge and Pipeline
110,000
CY
$7.59
$834,900
$500,940
$0
Medicine Lake
Lake Sediment
C08
Regional Repository
110,000
CY
$10.31
$1,134,100
$680,460
$226,820
Cave Lake
Wetland Pond
C01
Excavation
32,000
CY
$2.70
$86,400
$51,840
$0
Cave Lake
Wetland Pond
HAUL-1
Haul 10 miles one-way
32,000
CY
$8.90
$284,800
$170,880
$0
Cave Lake
Wetland Pond
C08
Regional Repository
32,000
CY
$10.31
$329,920
$197,952
$65,984
Cave Lake
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Cave Lake
General
LB-07a
Construct New Levee
14,000
LF
$151
$2,114,000
$1,268,400
$422,800
Cave Lake
Wetland Sediment
LB-08
Place Sand Cap
310,000
CY
$8.02
$2,486,200
$1,491,720
$497,240
Cave Lake
Lake Sediment
LB-04b
Dredge and Pipeline
180,000
CY
$7.59
$1,366,200
$819,20
$0
Cave Lake
Lake Sediment
C08
Regional Repository
180,000
CY
$10.31
$1,855,800
$1,113,480
$371,160
Bare Marsh
Wetland Pond
C01
Excavation
32,000
CY
$2.70
$86,400
$51,840
$0
Bare Marsh
Wetland Pond
HAUL-1
Haul 10 miles one-way
32,000
CY
$8.90
$284,800
$170,880
$0
Bare Marsh
Wetland Pond
C08
Regional Repository
32,000
CY
$10.31
$329,920
$197,952
$65,984
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-131
Table 12.2-7 (Continued)
Summary of Estimated Costs for Lead in Floodplains
Sili- \:uili-
\\;isk- l \ pi-
1(1)
l)i-siri|)iiiiii
Qll;illlil\
I nil
I nil
Din-il
(;i|)il;il
( IISl
Din-il
C;i|)il;il
( IISl
Indiri-i'l
C';i|)il;il
( IISl
Nil
I'n-si-nl
Y;ilui- ill'
(WsM
Bare Marsh
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Bare Marsh
General
LB-07a
Construct New Levee
8,000
LF
$151
$1,208,000
$724,800
$241,600
Bare Marsh
Wetland Sediment
LB-08
Place Sand Cap
270,000
CY
$8.02
$2,165,400
$1,299,240
$433,080
Thompson Lake
Wetland Pond
C01
Excavation
48,000
CY
$2.70
$129,600
$77,760
$0
Thompson Lake
Wetland Pond
HAUL-1
Haul 10 miles one-way
48,000
CY
$8.90
$427,200
$256,320
$0
Thompson Lake
Wetland Pond
C08
Regional Repository
48,000
CY
$10.31
$494,880
$296,928
$98,976
Thompson Lake
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Thompson Lake
General
LB-07a
Construct New Levee
8,000
LF
$151
$1,208,000
$724,800
$241,600
Thompson Lake
Wetland Sediment
LB-08
Place Sand Cap
480,000
CY
$8.02
$3,849,600
$2,309,760
$769,920
Thompson Lake
Lake Sediment
LB-04b
Dredge and Pipeline
61,000
CY
$7.59
$462,990
$277,794
$0
Thompson Lake
Lake Sediment
C08
Regional Repository
61,000
CY
$10.31
$628,910
$377,346
$125,782
Thompson Marsh
Wetland Pond
C01
Excavation
16,000
CY
$2.70
$43,200
$25,920
$0
Thompson Marsh
Wetland Pond
HAUL-1
Haul 10 miles one-way
16,000
CY
$8.90
$142,400
$85,440
$0
Thompson Marsh
Wetland Pond
C08
Regional Repository
16,000
CY
$10.31
$164,960
$98,976
$32,992
Thompson Marsh
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Thompson Marsh
General
LB-07a
Construct New Levee
11,000
LF
$151
$1,661,000
$996,600
$332,200
Thompson Marsh
Wetland Sediment
LB-08
Place Sand Cap
95,000
CY
$8.02
$761,900
$457,140
$152,380
Thompson Marsh
Lake Sediment
LB-04b
Dredge and Pipeline
29,000
CY
$7.59
$220,110
$132,066
$0
Thompson Marsh
Lake Sediment
C08
Regional Repository
29,000
CY
$10.31
$298,990
$179,394
$59,798
Anderson Lake
Wetland Pond
C01
Excavation
16,000
CY
$2.70
$43,200
$25,920
$0
Anderson Lake
Wetland Pond
HAUL-1
Haul 10 miles one-way
16,000
CY
$8.90
$142,400
$85,440
$0
Anderson Lake
Wetland Pond
C08
Regional Repository
16,000
CY
$10.31
$164,960
$98,976
$32,992
Anderson Lake
Wetland Sediment
LB-06
Hydraulic Controls
3
EA
$57,200
$171,600
$102,960
$34,320
Anderson Lake
General
LB-07a
Construct New Levee
16,000
LF
$151
$2,416,000
$1,449,600
$483,200
Anderson Lake
Wetland Sediment
LB-08
Place Sand Cap
71,000
CY
$8.02
$569,420
$341,652
$113,884
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-132
Table 12.2-7 (Continued)
Summary of Estimated Costs for Lead in Floodplains
Sili- \:iiik-
\\;isk- l \ |K-
1(1)
Disiiipliim
Qll;illlil\
I nil
I nil
Diivil
(;i|)il;il
( IISl
Diivil
C;i|)il;il
( IISl
In diivil
C';i|)il;il
( IISl
Nil
1'ivsi-ni
\';ilui' ill'
(WsM
Anderson Lake
Lake Sediment
LB-04b
Dredge and Pipeline
120,000
CY
$7.59
$910,800
$546,480
$0
Anderson Lake
Lake Sediment
C08
Regional Repository
120,000
CY
$10.31
$1,237,200
$742,320
$247,440
Other (Ag-lands)
Wetland Sediment
N/A
Allowance for cleanup
6
LS
$1,000,000
$6,000,000
$0
$0
TOTAL CAPITAL COST $74,000,000
TOTAL O&M COST $ 7,200,000
TOTAL COST $81,000,000
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-133
Table 12.2-8
Summary of Estimated Costs for Particulate Lead in Surface Water
Siniriv II)
\i ra
Wj-lr l\ iii-
DcMTiiilion
(.)iiiinlil\
1 nil
1 nil
Dim-I
( iipiliil ( ¦>•.!
1 >i led
( ;i|iil;il
( on|
Iniliml
( ;i|iil;il
( o\|
N.I
I'llMllI
\ aliic ill'
O&M
BNKWDG
Lower Coeur d'Alene River
Bank Wedge
Excavate CDR Banks
405,681
Li
$4.92
SI,995,951
SI,197,570
$0
BNKWDG
Lower Coeur d'Alene River
Bank Wedge
Haul 10 miles one-way
405,681
CY
$8.90
$3,610,561
$2,166,337
$0
BNKWDG
Lower Coeur d'Alene River
Bank Wedge
Regional Repository
405,681
CY
$10.36
$4,202,855
$2,521,713
$840,571
BNKWDG
Lower Coeur d'Alene River
Bank Wedge
Vegetative Bank Stabilization
89,383
LF
$36.00
$3,217,788
$1,930,673
$643,558
BNKWDG
Lower Coeur d'Alene River
Bank Wedge
Bank Stabilization via Revetments
87,000
LF
$83.00
$7,221,000
$4,332,600
$1,444,200
BNKWDG
Lower Coeur d'Alene River
Bank Wedge
Floodplain/Riparian Replanting
5,362,980
SF
$0.39
$2,091,562
$1,254,937
$418,312
Capital $36,000,000
O&M $ 3,300,000
Total $39,300,000
Splay Areas
FPSED
Lower Coeur d'Alene River
Floodplain Sediments
Sediment Trap
4
EA
$270,020
$1,080,080
$648,048
$0
FPSED
Lower Coeur d'Alene River
Floodplain Sediments
Dredge & Pipeline
100,000
CY
$7.59
$759,000
$455,400
$0
FPSED
Lower Coeur d'Alene River
Floodplain Sediments
Regional Repository
100,000
CY
$10.36
$1,036,000
$621,600
$207,200
Capital $ 4,600,000
O&M $ 210,000
Total $ 4,810,000
Dredging
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Dredge & Pipeline
500,000
CY
$7.59
$3,795,000
$2,277,000
$0
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Regional Repository
500,000
CY
$10.36
$5,180,000
$3,108,000
$1,036,000
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Dredge & Pipeline
200,000
CY
$7.59
$1,082,334
$649,400
$0
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Regional Repository
200,000
CY
$10.36
$1,477,336
$886,402
$295,467
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Dredge & Pipeline
200,000
CY
$7.59
$771,599
$462,960
$0
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Regional Repository
200,000
CY
$10.36
$1,053,198
$631,919
$210,640
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Dredge & Pipeline
200,000
CY
$7.59
550,123
$330,074
$0
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Regional Repository
200,000
CY
$10.36
$750,893
$450,536
$150,179
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-12-134
Table 12.2-8 (Continued)
Summary of Estimated Costs for Particulate Lead in Surface Water
N.I
1 nil
1 >i reel
Indiml
I'llMllI
Dirri'l
( ;i|)il;il
( ;i|)il;il
\ llllIC III'
Siniriv II)
\i r:i
Wil-lf l\|lf
DrMiipliiin
(.)iiiinlil\
1 nil
( iipilnl ( iM
( on|
( o\|
O&M
Dredging (Continued)
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Dredge & Pipeline
200,000
CY
$7.59
$392,251
$235,351
$0
SED-BED
Lower Coeur d'Alene River near Dudley
Sediment Bed Load
Regional Repository
200,000
CY
$10.36
$535,405
$321,243
$107,081
Note: 500,000 cy in year 0 and 200,000 cy in years 5, 10, 15, 20.
Capital
$25,000,000
O&M
$ 1,800,000
Total
$26,800,000
TOTAL CAPITAL COST
$66,000,000
TOTAL O&M COST
$ 5,300,000
TOTAL COST
$71,000,000
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-135
Table 12.4-1
Summary of the Selected Remedy for the Spokane River
Area
IScnchmark
Actions
Spokane River upstream of
Upriver Dam
Reduce human health and ecological exposures at
selected shoreline sediment depositional areas.
Clean up sediment containing lead at concentrations
greater than 700 mg/kg (sites with human health
exposure). Clean up sediment resulting in unacceptable
risks to ecological receptors (sites with ecological
exposure).
Reduce concentrations of metals in surface water,
moving toward achievement of AWQC
A reduction of dissolved metals loads of approximately
16% is estimated to result from implementation of the
Selected Remedy. Additional load reductions would
result from implementation of remedies in the Box. The
estimated high flow reduction in particulate lead load
needed is at least 50% to reduce year-round lead
concentrations to below chronic AWQC in the Spokane
River.
Shoreline sites. Use a combination of capping, removals, and
performance monitoring.
Upriver Dam sediments. Remediate contaminated sediments
stored behind Upriver Dam and conduct performance
monitoring.
Remedial actions directed at surface water load reductions in the
Basin to reduce metals transport. Key remedial actions
expected to reduce metals entering the Spokane River include
the implementation of a Coeur d'Alene Lake water quality
protection program, lower Coeur d'Alene River bed and bank
remediation, and South Fork of the Coeur d'Alene River
groundwater remediation actions, particularly within the Box
near Kellogg.
Estimated Total Present Worth Cost = $4,500,000 to $11,000,000
Spokane River within
reservation
Reduce concentrations of metals in surface water,
moving toward achievement of tribal water quality
standards
Quantify risks to tribal members practicing
traditional subsistence lifestyles and to ecological
receptors
Remedial actions directed at surface water load reductions in the
Basin to reduce metals transport (see Spokane River actions
above).
Perform Tribal-Specific Human Health Risk Assessment.
No remedial actions included within the reservation under the Selected Remedy
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-136
Table 12.4-2
Summary of Estimated Cost Range for the Spokane River
Description
I nil
Qii2X
s:.(,5".(44
Monitoring
Beach monitoring
Is
1
$0
$0
$0
$420,000
$420,000
Surface water monitoring
Is
1
$0
$0
$0
$470,000
$470,000
TOTAL LOWER RANGE COST
ESTIMATEb
$2,000,000
$1,200,000
$1,400,000
$4,500,000
LOW I K R.WCI. I S 1 IMA I I.
Shoivlini- Silos
Excavate
cy
28,000
$2.70
$75,600
$45,360
$0
$120,960
Backfill
cy
28,000
$18.00
$504,000
$302,400
$0
$806,400
Disposal (Subtitle D)
cy
28,000
$36.40
$1,019,200
$0
$0
$1,019,200
Haul to landfill
cy-mi
840,000
$0.63
$525,000
$315,000
$0
$840,000
Revegetation
ac
2
$41,000
$82,000
$49,200
$0
$131,200
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 12.0
Page 12-137
Table 12.4-2 (Continued)
Summary of Estimated Cost Range for the Spokane River
Description
I nil
(.)ii;inlil\
I nil (osl
Dirccl
( iinil.il ( osl
Indirect ( ;i|)il;il
(osl'
O&M ( osl
(30 Yr. P rcscn 1
Wo rlli)
l oliil ( osl
Shoreline Sites (continued)
1 !e;ich iikiiiiiiiriiiu
Is
1
$0
so
so
Surface ualcr iiK
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-1
13.0 STATUTORY DETERMINATIONS
This section describes how the Selected Remedy, which is an interim measure, satisfies the
statutory requirements of CERCLA§121 (as required by NCP§300.430(f)(5)(ii)). This section
also describes the five-year review requirements for the Selected Remedy. The following is an
overview of the five statutory requirements.
• Protection of human health and the environment. This section describes how the
Selected Remedy will adequately protect human health and the environment
through treatment, engineering controls, and/or institutional controls
(NCP§300.430(f)(5)(ii)(A)). Within its scope, the Selected Remedy protects
human health and the environment from the exposure pathway or threat it is
addressing and the waste material being managed.
• Compliance with ARARs specific to the Selected Remedy. This section describes
the federal and state ARARs the Selected Remedy will attain. This section also
describes the waiver invoked, if any, and the justification for invoking the waiver
(NCP§§300.430(f)(5)(ii)(B) and (C)) for any ARARs the remedy will not attain.
This section also describes other available information that does not constitute an
ARAR (e.g., advisories, criteria, and guidance that are useful in selecting,
designing, and implementing the remedy).
• Cost-effectiveness. This section describes how the Selected Remedy meets the
Superfund program definition of a cost-effective remedy as one whose "costs are
proportional to its overall effectiveness" (NCP§300.430(f)(l)(ii)(D)). The
"overall effectiveness" of a remedy is determined by evaluating the following
three of the five balancing criteria used in the detailed analysis of alternatives:
1) long-term effectiveness and permanence; 2) Reduction in toxicity, mobility,
and volume through treatment; and 3) short-term effectiveness.
• Utilization of permanent solutions and alternative treatment (or resource
recovery) technologies to the maximum extent practicable. This section describes
the rationale for the remedy selected, explaining how the remedy provides the
best balance of tradeoffs among the alternatives with respect to the balancing
criteria set out in NCP§300.430(f)(l)(i)(B), such that it represents the maximum
extent to which permanence and treatment can be practicably utilized at this site.
The remedy selected is not designed or expected to be final, but represents the
best balance of tradeoffs among alternatives with respect to pertinent criteria,
given the limited scope of the action.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-2
• Preference for treatment as a principal element. This section describes treatment
components that support the statutory preference for treatment. The Selected
Remedy satisfies the statutory preference because it contains treatment within its
scope.
Within the scope of this remedial action, as is more specifically described in the remainder of
this section, the Selected Remedy will: 1) provide an appropriate level of protectiveness of
human health and the environment; 2) comply with federal and state requirements that are
applicable or relevant and appropriate within its scope; 3) result in a cost-effective action;
4) utilize permanent solutions and alternative treatment (or resource recovery) technologies to
the maximum extent practicable; and 5) satisfy the statutory preference for treatment as a
principal element of the remedy (i.e., reduce the toxicity, mobility, or volume of hazardous
substances, pollutants, or contaminants as a principal element through treatment).
The remedial actions selected in this ROD are not intended to fully address contamination within
the Basin. Thus, achieving certain water quality standards developed under the Clean Water Act
and the Safe Drinking Water Act, such as water quality standards and MCLs, are outside of the
scope of the remedial action selected in this ROD and are not applicable or relevant and
appropriate at this time.29 Similarly, special status species protection requirements under the
MTBA and ESA are only applicable or relevant and appropriate as they apply to the remedial
actions included within the scope of the Selected Remedy. Although these requirements are not
ARARs throughout the Basin for this Selected Remedy, the priority cleanup actions included in
the remedy were selected to progress towards the compliance with surface water quality
standards and special status species protection requirements.
At present, the risks to persons, including Spokane tribal members, and others who may practice
a subsistence lifestyle in the Spokane River have not been quantified. EPA and the Spokane
Tribe are cooperating in planning additional testing and studies that will be implemented to
evaluate the potential exposures to subsistence users. The results of those tests and studies will
determine appropriate future response actions to be taken, if any.
The Selected Remedy is designed to provide remedial actions toward meeting the statutory
requirement of protectiveness of human health and the environment (see 40 CFR
300.430(a)(i)(B) and 40 CFR 300.430 (f)(l)(ii)(c)(l)). Accordingly, such a remedy, by its nature,
need not be as protective as the final remedy is required to be under CERCLA. Hence, the
Selected Remedy is sufficiently protective in the context of its scope, even though it does not, by
itself, meet the statutory protectiveness standard that a final remedy would have to meet. In
29 The state water quality standards and some federal water quality criteria are applicable or relevant and appropriate
to point source discharges to surface water created as a result of implementation of the Selected Remedy. Similarly,
maximum contaminant levels are relevant and appropriate at residences where an alternate drinking water supply is
provided or drinking water is treated.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-3
addition, because this remedy will result in hazardous substances, pollutants, or contaminants
remaining on-site above levels that allow for unlimited use and unrestricted exposure, statutory
reviews will be conducted at least every five years after initiation of remedial action to ensure
that the remedy is, or will be, protective of human health and the environment.
13.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The Selected Remedy will adequately protect human health and the environment through
treatment, engineering controls, and/or institutional controls (NCP§300.430(f)(5)(ii)(A)) within
its scope, which includes:
• All of the remedy for protection of human health in the community and residential
areas of the Upper Basin and Lower Basin, including identified recreational areas
• Approximately 30 years of prioritized actions for protection of the environment in
the Upper Basin and Lower Basin
• All of the Spokane River human health remedy upstream of Upriver Dam and all
of the environmental remedy from the Idaho/Washington border to Upriver Dam
13.1.1 Protection of Human Health in the Community and Residential Areas of the Upper
Basin and the Lower Basin
The Selected Remedy will be protective of human health. The Selected Remedy will reduce
exposure to lead in soil and house dust using a combination of vegetative barriers for soil lead
concentrations between 700 mg/kg and 1,000 mg/kg and partial excavation and disposal for soil
lead concentrations greater than 1,000 mg/kg such that there is a 5 percent or less probability of a
typical child having a blood lead level of greater than 10 (j,g/dL and a 1 percent or less
probability of a typical child having a blood lead level of greater than 15 (j,g/dL. Actions to
reduce exposure to arsenic in soil, which is often co-located with lead, will result in a lifetime
RME excess cancer risk for a residential exposure scenario within EPA's target range of to 10"6
to 10"4
The Selected Remedy will achieve compliance with drinking water standards established for
protection of human health through a combination of hookups to public water supply systems,
installation of new wells in uncontaminated aquifers, and point-of-use treatment. The Selected
Remedy does not address potential future use of groundwater as a drinking water supply.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-4
The Selected Remedy will reduce human exposure to lead and other metals in fish and other
aquatic food sources. The degree of reduction achieved will depend on the extent individuals
voluntarily reduce their consumption of affected food sources. In the long term, protection
would be achieved through reductions in the levels of metals in whole fish and other aquatic food
sources that would occur through implementation of the ecological cleanup actions over time.
The Selected Remedy for protection of human health in community and residential areas is not
expected to fully protect traditional or modern subsistence lifestyles. In the long term, protection
for subsistence lifestyles would be achieved through reductions in the levels of metals in surface
water, sediment, and aquatic food sources that would occur through implementation of the
ecological cleanup actions.
The Selected Remedy will not pose unacceptable short-term risks or cross-media impacts. There
is some short-term risk to the community associated with materials hauling; however, these risks
are acceptable in relation to the overall long and short-term risk reduction that would result from
implementation of the remedy. No significant cross-media impacts are anticipated.
Certain potential exposures outside of the community and residential areas of the Upper Basin
and Lower Basin are not addressed by this ROD, and will continue to present risks of human
exposure to hazardous substances. These potential exposures impacting human health include:
• Recreational use at areas in the Upper Basin and Lower Basin where cleanup
actions are not implemented pursuant to this ROD
• Subsistence lifestyles, such as those traditional to the Coeur d'Alene and Spokane
Tribes
• Potential future use of groundwater that is presently contaminated with metals
13.1.2 Protection of the Environment in the Upper Basin and Lower Basin
Within its scope, the Selected Remedy protects human health and the environment in the Upper
Basin and Lower Basin from the exposure pathway or threat it is addressing and the waste
material being managed.
The Selected Remedy for protection of the environment in the Upper Basin and Lower Basin
will result in substantial reductions of exposures of humans and ecological receptors to metals in
the areas the Selected Remedy addresses; however, full protection of human health and the
environment would not be achieved by the Selected Remedy. The anticipated benefits of the
Selected Remedy are listed below.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-5
Risks to aquatic receptors will be reduced through surface and adit water treatment and
engineering controls (removal and containment) to reduce metals loads and concentrations. A
reduction of about 580 pounds per day of dissolved zinc from the Upper Basin and Lower Basin
is anticipated. The dissolved metals reductions, combined with measures to clean up the effects
of mining practices on riverine and riparian areas, are expected to result in an overall
improvement in the fishery. Reaches that support adult fisheries will be connected with reaches
capable of supporting spawning and rearing through migratory corridors to allow increased
movement between the tributaries and the river. This would include re-establishment of fisheries
in Ninemile Creek, improvements of spawning and rearing fisheries in Pine Creek, and
improvements in the fisheries and water quality in the South Fork and Lower Basin.
Risks to waterfowl and other plants and animals in the Lower Basin floodplains would be
reduced through sediment removals and capping in wetland and lake feeding areas.
Approximately 2,669 acres of wetland feeding area and 1,859 acres of lake feeding area with
sediment containing lead at concentrations exceeding 530 mg/kg, the LOAEL for waterfowl,
would be cleaned up.30 The potential for recontamination of these areas during future flood
events would be limited through use of hydraulic controls, stabilization of contaminated
sediment sources in the Upper Basin, stabilization of 33 miles of contaminated river banks in the
Lower Basin, and limited removals of contaminated bed sediments from the lower Coeur
d'Alene River.
Risks to riparian and riverine receptors would be reduced through cleanup of 33 miles of
contaminated river bank and adjacent riparian zone in the Lower Basin and cleanup of the
riverine and riparian zone in Upper Basin areas where cleanup is conducted.
Risks to recreational and subsistence users would be reduced through cleanup of contaminated
metals at 33 miles of river bank in the Lower Basin and at recreational use areas of Lane Marsh,
Medicine Lake, Cave Lake, Bare Marsh, Thompson Lake, Thompson Marsh, and Anderson
Lake.
The risk of recontamination of Lower Basin floodplain areas and Spokane River shoreline areas
would be reduced through removal and containment of many of the waste piles that are sediment
sources, through bioengineering of unstable stream and bank sediments in the Upper Basin,
through stabilization of 33 miles of erodable river bank in the Lower Basin, and through removal
of 1.3 million cubic yards of contaminated bed sediments from the lower Coeur d'Alene River.
30 The acres of lake area shown are the entire areas of the lakes. To develop estimated costs, it is anticipated
contaminated sediments will be cleaned up to a water depth of six feet (an average of approximately 25% of the total
lake area). These water depths represent the highest use feeding areas and, consequently, the areas of greatest
exposure to waterfowl and other animals.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-6
The Selected Remedy will not pose unacceptable short-term risks or cross-media impacts.
Where the potential exists for unacceptable short-term risks or cross-media impacts, it will be
mitigated using engineering controls. Actions included in the Selected Remedy are generally
focused on unpopulated areas and use remedial actions that employ limited waste hauling,
thereby minimizing the associated short-term risks to the community. Cross-media impacts
would be limited to potential short-term increases in sediment levels in surface water resulting
from soil or sediment removal actions conducted in or adjacent to streams or lakes. These
sediment removals would be conducted in accordance with Clean Water Act requirements.
These risks are acceptable in relation to the overall long and short-term risk reduction that would
result from implementation of the remedy. The work will be sequenced to ensure that current
land uses (e.g., recreational) will be available throughout the period of cleanup.
13.1.3 Spokane River
The Selected Remedy for the Spokane River will protect human health upstream of Upriver Dam
and the environment from the Idaho/Washington border to Upriver Dam by reducing exposures
to metals, principally lead, arsenic, and zinc, at shoreline sites used for recreation by humans and
feeding by wildlife. The Selected Remedy will reduce exposure to lead at shoreline sites with
lead concentrations exceeding 700 mg/kg using a combination of removals and capping such that
there is a 5 percent or smaller probability of a typical child having a blood lead level exceeding
10 (j,g/dL and a 1 percent or smaller probability of a typical child having a blood lead level
exceeding 15 (j,g/dL. These same actions would reduce the exposure to arsenic, which is co-
located with lead.
The Selected Remedy for the Spokane River will reduce the exposure of waterfowl and other
wildlife to sediment contaminated with lead and zinc through a combination of sediment
removals and capping in critical habitat areas identified by the Washington Department of
Ecology.
The Selected Remedy for the Spokane River will not pose unacceptable short-term risks or cross-
media impacts. There is a marginal short-term risk to the community associated with materials
hauling. Cross-media impacts would be limited to potential short-term increases in sediment
levels in surface water resulting from soil or sediment removal actions conducted in or adjacent
to the river. These sediment removals would be conducted in accordance with Clean Water Act
requirements. These risks are acceptable in relation to the overall long and short-term risk
reduction that would result from implementation of the remedy.
The long-term protectiveness of the remedy will be strongly influenced by remedial activities
conducted in the Upper Basin and Lower Basin. These areas are the sources of the metals-
impacted sediments that have been deposited within the Spokane River floodway in the past and
are potential future sources of recontamination. These areas are also the primary sources of
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 2, Decision Summary
Section 13.0
Page 13-7
metals in surface water in the Spokane River. Water quality standards for zinc are currently
exceeded, and standards for lead are periodically exceeded. These conditions are expected to
continue in the future unless sources in the Upper Basin and Lower Basin are remediated.
13.2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS
The Selected Remedy will comply with those federal, state, and tribal requirements that are
applicable or relevant and appropriate to the scope of the response action. Background
information on these ARARs can be found in Parts 2 and 3 of the Final FS Report. No ARARs
waivers are being invoked at this time.
ARARs for the remedy are discussed below under these categories:
• Waste Management and Repository Design
• Air Quality
• Surface Water Quality
• Drinking Water Quality
• Native American Concerns and Cultural Resources Protection
• Special Status Species
• Sensitive Environments
• Other Requirements
Guidance and other nonpromulgated materials to be considered (TBC) are described in the last
subsection.
Waste Management and Repository Design
Idaho Solid Waste Management Rules regulations, IDAPA 58.01.05. Idaho regulations define
the siting, design, operational, and closure requirements for solid waste management facilities.
"Tier II" and "Tier III" facilities include landfills for non-municipal solid wastes, with Tier III
facilities generally for management of solid wastes where leachate or gas may be formed. These
regulations explicitly do not apply to "waste dumps, . . . tailings and other materials uniquely
associated with mineral extraction, beneficiation or processing operation" and thus are not
applicable. However, Tier II non-municipal solid waste landfill requirements are relevant and
appropriate to the design, operation, and closure of mine waste repositories in the upper and
lower Coeur d'Alene Basin. Sections of Tier III non-municipal solid waste landfill requirements
may be relevant and appropriate to the design, operation, and closure of some repositories,
including repositories that contain principal threat materials (e.g., metal concentrates). The
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particular provisions of these regulations that are relevant and appropriate for discrete remedial
actions will be identified through the remedial design process.
RCRA Subtitle C: Hazardous Waste Management, IDAPA 58.01.05. Pursuant to the RCRA
Bevill Amendment, 42 USC§6921(b)(3)(A), solid wastes from the extraction, beneficiation, and
some processing of ores and minerals are excluded from the RCRA Subtitle C requirements for
managing hazardous wastes. In the Coeur d'Alene Basin, such excluded wastes include waste
rock, mill tailings, and metal concentrates. However, elements of Subtitle C may be relevant and
appropriate to ensure the safe management of some solid wastes, including principal threat
materials (e.g., metal concentrates). RCRA Subtitle C elements that may be relevant and
appropriate may include, for example, selected portions of the requirements for design and
operation of a hazardous waste landfill, 40 CFR Part 264, Subpart N, IDAPA 58.01.05.009, and
selected portions of the requirements for landfill closure and post-closure, 40 CFR Part 264,
Subpart G, IDAPA 58.01.06.012-.013. For the management of RCRA hazardous wastes that are
not Bevill-exempt, applicability of Subtitle C provisions depend on whether the wastes are
managed within the Area of Contamination (AOC). 55 FR 8760 (Mar. 8, 1990). Applicable
requirements of RCRA Subtitle C (or the state equivalent) may be satisfied by off-site disposal,
consistent with the Off-Site Disposal Rule, 40 CFR 300.440. RCRA Subtitle C also provides
treatment standards for debris contaminated with hazardous waste ("hazardous debris"),
40 CFR 268.45, IDAPA 58.01.05.011, although the lead agency may determine that such debris
is no longer hazardous, consistent with 40 CFR 261.3(f)(2), IDAPA 52.01.05. These
requirements will be applicable for debris contaminated with hazardous waste that will be
managed outside the AOC. The particular provisions of Subtitle C that are applicable or relevant
and appropriate for discrete remedial actions will be identified through the remedial design
process.
RCRA Subtitle D: Criteria for Classification of Solid Waste Disposal Facilities and Practices, 40
CFR Part 257, Subpart A. These regulations are applicable for management and disposal of
material generated by cleanup activity pursuant to the Selected Remedy in this ROD. Written for
non-municipal non-hazardous waste disposal units, the regulations require that facilities in
floodplains not restrict the flow of the base flood, nor reduce the temporary water storage
capacity of the floodplain, nor result in washout of solid waste; and not cause or contribute to the
taking of any endangered or threatened species. Facilities must not cause a discharge of
pollutants into waters of the U.S. that violates the requirements of the National Pollutant
Discharge Elimination System and must not contaminate an underground drinking water source
beyond the solid waste boundary.
Idaho Land Remediation Rules, IDAPA 58.01.18.027. The Idaho Land Remediation Rules are
only applicable to persons who wish to enter voluntary remediation agreements with the State of
Idaho. However, EPA has concluded that the Institutional Controls provisions of these
regulations are relevant and appropriate for managing waste in locations within the Basin where
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metals concentrations remain above risk or regulatory levels after remediation. These provisions
describe a range of institutional controls, including legal use restrictions, that may be available in
certain situations.
Idaho Exploration and Surface Mining regulations, IDAPA 20.03.02. These regulations apply to
"surface mining operations," as defined to mean the activities performed in an area where
minerals are extracted from the ground. "Minerals" include clay, stone, sand, gravel, "and any
other similar, solid material or substance of commercial value to be excavated from natural
deposits on or in the earth." IDAPA 20.03.02.010. Substantive requirements of these
regulations apply to borrow sources for soil, gravel, and similar clean materials for residential
yards, landfill caps, and other areas requiring fill or barriers to underlying contamination.
Provisions of IDAPA 20.03.02.140 are not mandatory, but may be relevant and appropriate to
the placement and consolidation of contaminated material generated by cleanup activity pursuant
to the Selected Remedy. Best management practices are listed for nonpoint source sediment
control, clearing and grubbing, placement of topsoil conducive to the growth of vegetation,
backfilling and grading, and erosion control.
Washington Hazardous Waste Management Act (Dangerous Waste) regulations, Ch. 173-303
WAC. These regulations are applicable to remedial actions in the State of Washington along the
Spokane River. They provide requirements for the identification, accumulation, transport,
treatment, and disposal of dangerous (including federally hazardous) wastes. (Note that the
Bevill Exemption from RCRA Subtitle C requirements does not apply in the State of
Washington.)
Washington Solid Waste Management Act regulations, Ch. 173-304 WAC. These regulations are
applicable for the management and disposal of soils and sediments that are not State of
Washington dangerous wastes and are excavated from Spokane River beaches within the State of
Washington. They provide minimum functional standards for solid waste handling.
Clean Air Act regulations, National Primary and Secondary Ambient Air Quality Standards
(NAAQS'), 40 CFR Part 50. These regulations are relevant and appropriate to soil removal
operations which may generate fugitive emissions. NAAQS have been promulgated for fine and
coarse particulates and for lead.
Idaho Rules for Control of Fugitive Dust, IDAPA 58.01.01.650-651. These regulations are
applicable to soil removal operations which may generate fugitive emissions. They require that
reasonable precautions be taken to prevent particulate matter from becoming airborne, including
using water or chemicals to control dust, covering trucks for transporting materials, and promptly
removing excavated materials.
Air Quality
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Idaho Pollution Control regulations: Toxic Air Pollutants, IDAPA 58.01.01.585-586. These
regulations provide screening emission levels and acceptable ambient concentrations (AAC) for
designated noncarcinogens and for carcinogens including arsenic. If a remedial action under
CERCLA causes an emission exceeding the ACC, Best Available Control Technology (BACT)
must be applied until the emission level falls below the AAC. ID APA 58.01.01.16. These
regulations are applicable to elements of the Selected Remedy, such as soil removal, having the
potential for creating excessive air emissions. Remedial actions will be carried out to minimize
air emissions, and BACT will be applied if necessary to remain below acceptable ambient levels.
Washington Clean Air Act regulations, Ch. 173-400 WAC, Ch. 173-460 WAC. These
regulations are relevant and appropriate to remedial activities that could generate fugitive dust
containing metals. They require that discharges from treatment units must meet acceptable
source impact levels (ASILs) at the property boundary. Generation of fugitive emissions is also
regulated.
Surface Water Quality
Clean Water Act Storm Water Multi-Sector General Permit for Industrial Activities. 65 FR
64746-64880 and 40 CFR 122.26. These regulations provide that discharges of storm water
associated with "industrial activities" require an NPDES permit. "Industrial activities" include
inactive mining facilities, hazardous waste treatment units, and RCRA Subtitle D landfills. The
substantive requirements of the Storm Water Multi-Sector General Permit for Industrial
Activities (Oct. 30, 2000) apply to elements of the Selected Remedy that result in discharges of
storm water, including constructing and operating mine waste repositories. Best management
practices (BMPs) must be used, and appropriate monitoring performed, to ensure that storm
water runoff does not exceed state water quality standards. It is not an ARAR for seepage or
mine drainage.
Clean Water Act Section 304—Federal Ambient Water Quality, 66 FR 18935-18936 (April 12,
2001). Section 304(a)(1) of the Clean Water Act requires EPA to develop, publish, and revise
criteria for water quality accurately reflecting the latest scientific knowledge. CERCLA Section
121(d)(2)(B)(i) provides that, "In determining whether or not any water quality criteria under the
Clean Water Act is relevant and appropriate under the circumstances of the release or threatened
release, the President shall consider the designated or potential use of the surface or groundwater,
the environmental media affected, the purposes for which such criteria were developed, and the
latest information available." On April 12, 2001, EPA notified the public of revised Ambient
Water Quality Aquatic Life Criteria for cadmium. These revised criteria are relevant and
appropriate to point source discharges to surface water, where those point sources are established
as part of the selected remedial action. These values are relevant and appropriate for the
Selected Remedy because they represent the latest scientific knowledge, as determined by EPA's
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Health and Ecological Criteria Division, Office of Science and Technology. They are also
relevant and appropriate for the Selected Remedy because these criteria were developed to better
protect aquatic organisms such as bull trout, a threatened species, that may be found within the
Coeur d'Alene Basin. The Selected Remedy will satisfy this ARAR by ensuring that point
source discharges established by the remedy do not cause exceedances of the Water Quality
Criteria for cadmium in receiving surface waters.
Idaho Water Quality Standards and Wastewater Treatment Requirements, IDAPA 58.01.02.
The Idaho water quality standards (WQS) that were submitted to EPA prior to May 30, 2000,
and any changes adopted by Idaho and approved by EPA between May 30, 2000 and the date of
this ROD are applicable to point source discharges to Idaho surface water, where those point
sources are established as part of the selected remedial action. Except as noted above concerning
federal AWQC for cadmium, WQS that have been adopted by Idaho but not yet submitted to or
approved by EPA, and are more stringent than the standards submitted to EPA prior to May 30,
2000, if any, are relevant and appropriate to point source discharges to Idaho surface water,
where those point sources are established as part of the selected remedial action. Idaho WQS for
protection of human health and aquatic life incorporate the National Toxics Rule (40 CFR
131.36) by reference for waters designated for aquatic life, recreation, and domestic water supply
(Section 210). Turbidity standards for protection of aquatic life (cold water biota) are also
applicable (Section 250). Variances can be granted for individual pollutants if the standard is
unattainable, based on the criteria in the rule (Section 260). Short-term exemptions allow
exceedances of the water quality standards under certain circumstances that are identified in the
regulation (e.g., dredge and fill activities) (Section 080). Where Idaho WQS are applicable or
relevant and appropriate to the Selected Remedy, point source discharges established by the
remedy, such as those from a water treatment plant, must not cause exceedances of WQS in the
receiving water body.
Idaho Stream Channel Alteration regulations, IDAPA 37.03.07. These regulations are
applicable to any alteration of stream channels. "Alteration" means to change the natural shape
of a stream channel, including by removing or placing any material or structures with potential to
affect the flow within the channel. The substantive requirements of these regulations are
applicable to elements of the Selected Remedy, such as streambank stabilization, with potential
to affect stream flows in the upper and lower basins. Substantive requirements include standards
for placement of rock riprap and for construction of cofferdams and temporary stream crossings.
Clean Water Act, Section 404—Dredge or Fill Requirements, 33 USC§1344, 33 CFR Parts 320-
330; 40 CFR Part 230. These requirements are applicable to work in or near navigable waters.
They establish requirements that limit the discharge of dredged or fill material into navigable
waters and associated wetlands. EPA guidelines for discharge of dredged or fill materials in 40
CFR Part 230 specify consideration of alternatives that have less adverse impacts and prohibit
discharges that would result in exceedance of surface water quality standards, exceedance of
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toxic effluent standards, and jeopardy of threatened or endangered species. Special consideration
is required for "special aquatic sites," which are defined to include wetlands.
Washington Water Quality Standards, Ch. WAC 173-201A. Washington's toxics standards for
protection of aquatic life (Section 070), as submitted to EPA by May 30, 2000, and any changes
adopted by Washington and approved by EPA between May 30, 2000 and the date of this ROD
are applicable to point source discharges to surface water in Washington State (with the
exception of tribal lands). These regulations are applicable to the Selected Remedy to the extent
the Selected Remedy results in a point source discharge to surface water in Washington State.
The Washington State regulations for human health protection incorporate the National Toxics
Rule (40 CFR 131.36) by reference. The regulations also provide for short-term modifications of
standards for specific water bodies during the performance of essential activities or to otherwise
protect the public interest (Section 110). For example, the turbidity criteria established under
Section 030 of the regulation can be modified to allow a temporary mixing zone during and
immediately after in-water or shoreline construction activities that may result in the disturbance
of in-situ sediments.
Washington Hydraulics Project Approval regulations, Ch. 220-110 WAC. Substantive
requirements of these regulations are applicable to remedial actions along and within the
Spokane River that could affect fish life. They provide actions required for riverbank protection,
temporary culvert construction, and dredging, for example.
Drinking Water Quality
Idaho Drinking Water Regulations, IDAPA 58.01.08.050; Safe Drinking Water Act, National
Primary Drinking Water regulations, 42 USC§300f, 40 CFR Part 141. These regulations are
applicable to all public drinking water systems supplying residents of the Coeur d'Alene Basin
and are relevant and appropriate to the provision of alternate water supplies, including the
installation of new groundwater wells or treatment at the tap. The regulations require that
contaminant concentrations in drinking water remain below MCLs and non-zero MCL goals
(MCLGs). By final rule effective February 22, 2002, EPA lowered the MCL for arsenic from
0.05 mg/L to 0.01 mg/L (66 FR 7061). While community water systems have until January 2006
to comply with the new MCL for arsenic, EPA has determined that the new MCL is relevant and
appropriate presently for ensuring that drinking water as provided by the Selected Remedy is
protective of human health.
Native American Concerns and Cultural Resources Protection
Native American Graves Protection and Repatriation Act (NAGPRA), 25 USC§3001 et seq.
43 CFR Part 10. NAGPRA and implementing regulations are intended to protect Native
American graves from desecration through the removal and trafficking of human remains and
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"cultural items" including funerary and sacred objects. To protect Native American burials and
cultural items, the regulations require that if such items are inadvertently discovered during
excavation, the excavation must cease and the affiliated tribes must be notified and consulted.
This program is applicable to ground-disturbing activities such as soil grading and removal.
American Indian Religious Freedom Act, 42 USC§1996 et seq. This statute is applicable to soil
excavation in areas of the Coeur d'Alene Basin. It protects religious, ceremonial, and burial sites
and the free practice of religions by Native American groups. If sacred sites are discovered in
the course of soil disturbances, work will be stopped and the Coeur d'Alene and/or Spokane
Tribes will be contacted. The statute has no implementing regulations; following the NAGPRA
process should meet with the intent of the law.
National Historic Preservation Act (NHPA), 16 USC§470f, 36 CFR Parts 60, 63, and 800. The
NHPA and implementing regulations require agencies to consider the possible effects on historic
sites or structures of actions proposed for federal funding or approval. Historic sites or structures
are those included on or eligible for the National Register of Historic Places, generally older than
50 years. If an agency finds a potential adverse effect on historic sites or structures, such agency
must evaluate alternatives to "avoid, minimize, or mitigate" the impact, in consultation with the
State Historic Preservation Office (SHPO). The NHPA and implementing regulations are
applicable to selected remedial activities such as mill building, demolition, and soil excavation
which could disturb historical sites or structures. In consultation with the SHPO, unavoidable
impacts on historic sites or structures may be mitigated through such means as taking
photographs and collecting historical records.
Archaeological Resources Protection Act (ARPA), 16 USC§470aa et seq., 43 CFR Part 7. ARPA
and implementing regulations prohibit the unauthorized disturbance of archaeological resources
on public and Indian lands. Archaeological resources are "any material remains of past human
life and activities which are of archaeological interest," including pottery, baskets, tools, and
human skeletal remains. The unauthorized removal of archaeological resources from public or
Indian lands is prohibited without a permit, and any archaeological investigations at a site must
be conducted by a professional archaeologist. ARPA and implementing regulations are
applicable for the conduct of any selected remedial actions that may result in ground disturbance.
Special Status Species
Endangered Species Act (ESA), 16USC 1531 etseq., 50 CFRParts 17, 402. TheESAand
implementing regulations make it unlawful to "harass, harm, pursue, hunt, shoot, wound, kill,
trap, capture, or collect" any federally-designated threatened or endangered species. The ESA
and implementing regulations are applicable to activities of the Selected Remedy (for example,
soil removal or repository construction) that could affect federally-designated threatened or
endangered species that may be present within the Coeur d'Alene Basin. Such species may
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include bull trout, bald eagle, lynx, and gray wolf. Consistent with ESA Section 7, if any
federally designated threatened or endangered species are identified in the vicinity of
remediation work, EPA will consult with the U.S. Fish and Wildlife Service to ensure that
remedial actions are conducted in a manner to avoid adverse habitat modification and jeopardy to
the continued existence of such species.
Migratory Bird Treaty Act (MBTA), 16 USC 703 et seq. The MBTA makes it unlawful to "hunt,
take, capture, kill" or take various other actions adversely affecting a broad range of migratory
birds, including tundra swans, hawks, falcons, songbirds, without prior approval by the USFWS.
(See 50 CFR 10.13 for the list of birds protected under the MBTA.) Under the MBTA, permits
may be issued for take (e.g., for research) or killing of migratory birds (e.g., hunting licenses).
The mortality of migratory birds due to ingestion of contaminated sediment is not a permitted
take under the MBTA. The MBTA and its implementing regulations are relevant and
appropriate for protecting migratory bird species identified within the Coeur d'Alene Basin. The
Coeur d'Alene Basin is located within the Pacific migratory flyway and provides important
habitat for migratory waterfowl. The selected remedies will be carried out in a manner that
avoids the taking or killing of protected migratory bird species, including individual birds or
their nests or eggs.
Idaho Classification and Protection of Wildlife regulations, IDAPA 13.01.06. These regulations
are relevant and appropriate to remedial activities that could affect wildlife species protected by
the State of Idaho, including species listed by state regulation as endangered, threatened, species
of special concern, and protected nongame species.
Washington Game Code, Ch. WAC 232-12. These regulations are relevant and appropriate to
beach cleanup activities and provide a list of state endangered, threatened, sensitive, and other
protected species.
Sensitive Areas
Rivers and Harbors Act, Section 10 regulations, 33 CFR Parts 320 through 330. These
regulations are applicable to activities in or near navigable waters. They prohibit unauthorized
obstruction or alteration of navigable waters.
Protection of Wetlands, Executive Order 11990; 40 CFR 6.302(a); 40 CFR Part 6, Appendix A.
This executive order and regulations apply to remedial activities in wetlands. They require
federal agencies to avoid adversely impacting wetlands, minimize wetland destruction, and
preserve the value of wetlands.
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Protection of Floodplains, Executive Order 11988, 40 CFR 6.302(b) and Appendix A. This
executive order and implementing regulations are applicable to the remedial actions within the
floodplain of the Coeur d'Alene River and its tributaries. Federal agencies are required to
evaluate the potential effects of actions that take place in floodplains and to avoid adverse
impacts.
Idaho Lakes Protection Act regulations, IDAPA 20.03.04. These regulations are applicable to
remedial work within the beds or waters of navigable lakes of the State of Idaho. They require
that the protection of property, navigation, fish and wildlife habitat, aquatic life, recreation,
aesthetic beauty and water quality be given due consideration.
Washington Shoreline Management Act and regulations, Ch. 90.58 RCW; Ch.173-18, Ch. 173-
22, and Ch. 173-27 WAC. This program is applicable to activities within 200 feet of a shoreline
of the State of Washington. Applicable activities should be conducted to protect the natural
character of the streamway. Shoreline protection measures (such as riprap) should be located,
designed, and constructed to avoid the need for channelization of a stream flow, consistent with
substantive provisions of the regulations.
Other Requirements
Hazardous Materials Transportation Act regulations, 49 CFR Parts 171-180. These regulations
apply to the movement of contaminated soils along public highways and require packaging,
documentation, and placarding appropriate to the materials being transported.
Washington Model Toxics Control Act regulations, Ch. 173-340 WAC. These regulations are
applicable to the remediation of beach sites between the State line and the Upriver dam. They
set soil remediation levels for protection of human health and the environment.
To Be Considered (TBC)
Responsibilities of Federal Agencies to Protect Migratory Birds, Executive Order 13186 (66 FR
3853, Jan. 17, 2001). This executive order encourages federal agencies to integrate migratory
bird conservation principles into agency plans and activities. Such efforts may include
preventing or abating pollution for the benefit of migratory birds or restoring or designing
migratory bird habitat. Substantive elements of this executive order are TBCs for the
implementation of the selected remedial actions.
Centers for Disease Control and Prevention (CDC) Statement on Preventing Lead Poisoning in
Young Children, 1991. This statement is a TBC providing an intervention level of 10 (J,g/dL
blood lead concentration.
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EPA Strategy for Reducing Lead Exposures, 1991. This strategy is a TBC for reducing the
amount of lead introduced into the environment and for significantly reducing the blood lead
level incidence above 10 (j,g/dL in children.
Revised Interim Lead Guidance for CERCLA Sites, EPA OSWER Directive 9355.4-12, 1994.
This guidance is a TBC that recommends a 400 ppm lead screening level and describes how to
develop site-specific remediation goals and a management strategy for lead contamination at
sites with multiple lead sources. OSWER Directive 9200.4-27P was issued in 1998 to clarify the
1994 policy of OSWER Directive 9355.4-12.
Integrated Exposure Uptake Biokinetic Model (IEUBK) for Lead in Children, PB 93 9635121.7-
15-2. This model was used to develop the 400 ppm lead screening level in OSWER Directive
Design and Construction of RCRA/CERCLA Final Covers, EPA/625/4-91/025, May 1991. This
publication provides guidelines for the design and construction of these covers.
Guidelines for Mine Tailings Repositories Coeur dAlene Basin Restoration Project, April 27,
1995. This TBC provides guidelines for location, design, construction, and management of a
mine waste repository.
Best Management Practices for Soils Treatment Technologies (EPA OSWER, 1997). This TBC
provides technologies for controlling cross-media transfer of contaminants during materials
handling activities.
Mine and Mill Waste Remedial Guidelines and Best Management Practices (CDA Basin
Restoration Project). Under this TBC, design and implementation of selected response actions
should consider a number of factors and techniques for protecting water quality, fish, and
wildlife habitat, while minimizing potential for human exposure.
Considering Wetlands at CERCLA Sites, EPA OSWER 9280.03, 1994. This guidance is a TBC
that discusses the consideration of potential impacts of response actions on wetlands at CERCLA
sites.
Idaho Non-Point Source Management Plan, 1999. This plan is a TBC for remedial activities that
disturb soils and sediments. The plan requires activities to be consistent with the state's goal of
restoration, maintenance, and protection of the beneficial uses of both surface water and
groundwater. Long-term goals include design and implementation of BMPs for surface water
and groundwater.
9355.4-12.
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13.3 COST-EFFECTIVENESS
In EPA's judgment, the Selected Remedy is cost-effective and represents a reasonable value for
the money to be spent. In making this determination, the following definition was used: "A
remedy shall be cost-effective if its costs are proportional to its overall effectiveness." (NCP
§300.430(f)(l)(ii)(D)). This was accomplished by evaluating the "overall effectiveness" of those
alternatives that satisfied the threshold criteria (i.e., were both protective of human health and the
environment and ARAR compliant). Overall effectiveness was evaluated by assessing three of
the five balancing criteria in combination (long-term effectiveness and permanence; reduction in
toxicity, mobility, and volume through treatment; and short-term effectiveness). Overall
effectiveness was then compared to costs to determine cost-effectiveness. The overall
effectiveness of this remedy was determined to be proportional to its costs and hence the remedy
is cost-effective.
To the extent that the costs of the alternatives that comprise the Selected Remedy exceed the
costs of other alternatives, the additional cost is proportional to the additional benefits in long-
term effectiveness and permanence, reduction in toxicity, mobility, and volume through
treatment, and short-term effectiveness.
Long-Term Effectiveness and Permanence. Within its limited scope, the Selected Remedy
will achieve overall effectiveness with respect to long-term effectiveness and permanence. The
Selected Remedy for protection of human health in the community and residential areas of the
Upper Basin and Lower Basin will achieve long-term effectiveness and permanence by reducing
residual risks resulting from exposure to lead in soil, house dust, drinking water, and aquatic
food sources to acceptable levels. An institutional controls program and follow-up health
services would be used to maintain remedy effectiveness over time.
The Selected Remedy for protection of the environment will achieve substantial reductions in
residual risks to aquatic receptors resulting from metals in surface water and to waterfowl and
other animals resulting from metals in wetland and lateral lake sediments. Overall, the Selected
Remedy would be expected to achieve about 50 to 70 percent of the dissolved metals load
reduction in the Upper Basin that would be anticipated from full implementation of Ecological
Alternative 3 for about 19 percent of the estimated cost of Ecological Alternative 3. The long-
term effectiveness and permanence would be enhanced through measures to limit the release of
contaminated sediments to surface water that could recontaminate remediated areas.
The Selected Remedy for the Spokane River upstream of the Spokane Indian Reservation will
achieve overall effectiveness with respect to long-term effectiveness and permanence. A
combination of removals and capping will result in low residual risks. Removals will be used at
sites where maintaining the long-term integrity of capping would be difficult. The potential
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exists for some recontamination of sites from upstream sources. Recontamination would be
addressed through monitoring and periodic maintenance.
Reduction in Toxicity, Mobility, or Volume Through Treatment. The Selected Remedy will
achieve overall effectiveness with respect to reduction in toxicity, mobility, or volume through
treatment. The Selected Remedy includes treatment to reduce the toxicity of drinking water and
surface water and, should amendments to limit the bioavailability of metals prove feasible,
treatment to reduce the toxicity of soil and sediment.
Short-Term Effectiveness. Within its limited scope, the Selected Remedy will achieve overall
effectiveness with respect to short-term effectiveness. Implementation of the Selected Remedy
for protection of human health in the community and residential areas of the Upper Basin and
Lower Basin is a top priority, and the Selected Remedy will achieve human health RAOs within
a relatively short time after completion of the remedial actions.
The Selected Remedy for protection of the environment will provide short-term effectiveness
through prioritizing actions and focusing environmental emphasis on the more serious problems,
including dissolved metals in rivers and streams, lead in floodplain soil and sediment, and
particulate lead in surface water, while limiting adverse impacts on the communities and
ecosystems. Examples of the problems the high priority actions will target include the most
highly erodable banks, wetlands with high waterfowl mortality, highly contaminated river bed
sediments in natural sediment deposition areas, and water with very high loads of dissolved
metals in Canyon Creek, where source-by-source removal and containment actions would be
costly and take a long time to implement. As construction is completed at individual sites, RAOs
for those soils, sediments, and source materials addressed by the Selected Remedy would be
achieved. Short-term impacts to the communities will be limited through generally focusing
actions in unpopulated areas and through use of remedial actions that employ limited waste
hauling.
The Selected Remedy for the Spokane River upstream of the Spokane Indian Reservation will
achieve overall effectiveness with respect to short-term effectiveness. RAOs at shoreline and
depositional areas would be achieved immediately after implementation of the remedy. Potential
short-term impacts to the community from material hauling and to the ecosystem from release of
contaminated sediments during construction will be limited.
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13.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE
TREATMENT (OR RESOURCE RECOVERY) TECHNOLOGIES TO THE
MAXIMUM EXTENT PRACTICABLE
EPA has determined that the Selected Remedy represents the maximum extent to which
permanent solutions and treatment technologies can be utilized in a practicable manner at the
site. Of those alternatives that are protective of human health and the environment and comply
with ARARs, EPA has determined that the Selected Remedy provides the best balance of
tradeoffs in terms of the five balancing criteria, while also considering the statutory preference
for treatment as a principal element and bias against off-site disposal without treatment and
considering State and community acceptance. EPA's balancing criteria in selecting a remedy
include: 1) long-term effectiveness and permanence; 2) reduction of toxicity, mobility, or
volume through treatment; 3) short-term effectiveness; 4) implementability; and 5) cost.
Engineering controls employed in the Selected Remedy, including removal and containment, are
appropriate for metals-contaminated soil, sediments, and house dust because these materials can
be reliably controlled in place. These engineering controls provide for long-term effectiveness
and permanence, achieve short-term effectiveness, and are implementable. As described in
Section 13.3, the overall effectiveness of the Selected Remedy was determined to be proportional
to its costs and hence the Selected Remedy is cost effective. As described in Section 13.5, the
Selected Remedy achieves the statutory preference for treatment as a principal element.
Initially, surface water treatment in Canyon Creek provides a better balance of tradeoffs than
more permanent removal and containment actions. Although surface water treatment would not
result in ecological improvements within Canyon Creek, it provides a better balance of tradeoffs
with respect to short-term effectiveness for the river system as a whole because:
• it can be implemented more rapidly than the comprehensive scope of removal and
containment actions that would be required to achieve an equivalent metals load
reduction
• it would result in fewer short-term impacts to the community from excavation,
hauling, and repositories of contaminated materials
• it would result in fewer short-term impacts to the environment from release of
contaminated sediment to surface water during construction
Surface-water treatment is also potentially much less costly than comprehensive removal and
treatment actions and achieves a reduction of toxicity through treatment. Surface-water treatment
will not result in achieving AWQC within Canyon Creek. Further characterization and source-
by-source cleanup would be required to achieve this goal.
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13.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The NCP establishes an expectation that EPA will use treatment to address the principal threats
posed by a site wherever practicable (40 CFR 300.430(a)(l)(iii)(A)). EPA has also established an
expectation for use of engineering controls, such as containment, for waste that poses a relatively
low, long-term threat or where treatment is impracticable (40 CFR 300.430(a)(l)(iii)(B)).
Principal threat wastes are those source materials considered to be highly toxic or highly mobile
that generally cannot be reliably contained, or would present a significant risk to human health or
the environment should exposure occur. Engineering controls employed in the Selected
Remedy, including removal and containment, are appropriate for metals-contaminated soil,
sediments, and house dust because these materials can be reliably controlled in place.
Although the Selected Remedy is not intended to fully address the statutory mandate for
permanence and treatment to the maximum extent practicable, the Selected Remedy does utilize
treatment, and thus supports that statutory mandate. A comprehensive evaluation for preference
for treatment will be conducted in subsequent decision documents. Treatment of surface water
to reduce toxicity is included in the Selected Remedy for the Upper Basin, as described in
Section 12.2. Treatment of drinking water at private wells is included in the Selected Remedy,
as described in Section 12.1. Treatment using amendments to reduce the toxicity of soil and
sediment will be evaluated as part of remedial design.
13.6 FIVE-YEAR REVIEW REQUIREMENTS
Because this remedy will result in hazardous substances, pollutants, or contaminants remaining
on-site above levels that allow for unlimited use and unrestricted exposure, statutory reviews will
be conducted at least every five years after initiation of remedial action to ensure that the
Selected Remedy is, or will be, protective of human health and the environment.
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14.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The Selected Remedy contains limited significant changes from the Preferred Alternative
identified in the Proposed Plan.
• The fisheries benchmark for the reach of Ninemile Creek identified as "mainstem
from East Fork confluence to 0.75 mile downstream of Blackcloud Creek" has
been changed from a Tier 2 fishery to a Tier 1 fishery. No changes were made to
the cleanup actions included in the Selected Remedy for Ninemile Creek.
• Cleanup of the Nabob Mine site in the East Fork of Pine Creek watershed has
been added to the Selected Remedy.
• The Coeur d'Alene Millsite has been cleaned up and has been deleted from the
Selected Remedy.
• The estimate of dissolved zinc load reduction in the Coeur d'Alene River at
Harrison has been revised from 660 pounds per day to 580 pounds per day, based
primarily on revisions to the projected effectiveness of passive treatment in
Canyon Creek.
• State legislation under the Basin Environmental Improvement Act established the
process for the formation of the Basin Environmental Improvement Project
Commission. This commission includes federal, state, tribal, and local
governmental involvement. EPA anticipates working as a member of the
commission for implementation of the ROD and development of priorities and
sequencing of cleanup activities.
It is EPA's intent to increase the removal of riverbed sediments in the Dudley reach of the Coeur
d'Alene River from 1.3 million cubic yards to up to 2.6 million cubic yards if the pilot removal
project is demonstrated to be compliant with ARARs and cost-effective. This would increase the
sediment removal from 6 percent of contaminated riverbed sediments to approximately 12
percent of the total contaminated sediments. The increased volume is intended to further reduce
downstream particulate lead movement during high flow events. This change will make
additional progress toward reducing potential recontamination and compliance with ARARs in
the Spokane River in the State of Washington. Based on current unit cost estimates, the cost of
this additional riverbed sediment removal is estimated at $26 million. This change is reflected in
Table 12.2-1, but the description of the Selected Remedy in the remaining sections of the ROD
has not been changed.
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Que Hee, S.S., B. Peace, C.S. Clark, J.R. Boyle, R.L. Bornschein, and P.B. Hammond. 1985.
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to Alternative 3 (Alt3)." Memo to Coeur d'Alene project file. URS Document Control
No. 4162500.07074.04.Z EPA 4.2.5. July 17.
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URS. 2002b. "Draft Selected Remedy and Ecological Alternatives 1 through 6; Updated
Probability Estimates for the SFCDR at Pinehurst (SF271) and the CDR at Harrison
(LC60)." Memo to Coeur d'Alene project file. URS Document Control No.
4162500.06998.04.z. May 29.
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Lead. U.S. Department of Health and Human Services. Atlanta, GA. 1999.
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of Solid Waste and Emergency Response. EPA/540-K-01-003. March 2001.
. 2001a. Coeur d'Alene Basin RI/FS, Basinwide Ecological Risk Assessment. May
2001.
. 2001b. Coeur dAlene Basin RI/FS, Remedial Investigation Report, Final. October
2001.
. 2001 c. Coeur d'Alene Basin RI/FS, Feasibility Study Report, Final. October 2001.
. 200 Id. Technical Memorandum, Interim Fisheries Benchmarks for the Initial
Increment of Remediation in the Coeur d'Alene Basin, Final. September 2001.
. 2001e. Coeur d'Alene Basin Proposed Plan. October 29, 2001.
. 2001f. Coeur d'Alene Basin RI/FS Technical Memorandum (Revision 1). Probabilistic
Analysis of Post-Remediation Metal Loading. September 20, 2001.
. 200 lg. Technical Memorandum: Stream Flow Treatment in Treatment Ponds. Coeur
d'Alene Basin RI/FS. Preliminary Draft. August 2001.
. 2001h. Final Technical Memorandum (Rev. 3): Estimation of Background
Concentrations in Soil, Sediment, and Surface Water in the Coeur d'Alene and Spokane
River Basins. Prepared by URS Greiner, Seattle, WA, and CH2M HILL, Bellevue, WA,
for EPA Region 10. October 5, 2001.
. 200 li. Final Field Sampling Plan Addendum No. 18, Fall 2000 Field Screening of
Sediment in Spokane River Depositional Areas, Summary of Results. January 2001.
. 2000a. Summer 2000 Drinking Water Standards and Health Advisories. EPA 822-B-
00-001.
. 2000b. A Guide to Developing and Documenting Cost Estimates During the Feasibility
Study. EPA 540-R-00-002. Prepared by the U.S. Army Corps of Engineers. July 2000.
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2000c. Human Health Alternatives Technical Memorandum, Coeur d'Alene Basin,
Idaho, Public Comment Draft. Prepared for USEPA Region 10 by CH2M HILL, under
subcontract to URSG. Work Assignment No. 069-RI-CO-102Q. Bellevue, Washington.
October 2000.
-. 2000d. Draft Final Screening Level Human Health Risk Assessment for Nonresidential
Receptors, Revision 2, Spokane River, Washington, Coeur d'Alene Basin RI/FS. Prepared
for USEPA Region 10 by URS Greiner Inc. Seattle, Washington. September 2000.
-. 2000e. TRW Recommendations for Sampling Soil at Lead (Pb) Sites. USEPA Technical
Review Workgroup for Lead. Washington, D.C.
-. 2000f. Comments and Responses on the Human Health Risk Assessment for the Coeur
d'Alene Basin. Vols. A and B. Prepared for the Idaho Department of Health and Welfare,
Division of Health, Idaho Department of Environmental Quality, and USEPA Region 10
by URS Greiner, Seattle, WA.
-. 1999a. A Guide to Preparing Superfund Proposed Plans, Records of Decision, and
Other Remedy Selection Decision Documents. EPA 540-R-98-031. OSWER. July 1999.
-. 1999b. Field Sampling Plan and Quality Assurance Project Plan Addenda for the
Bunker Hill Basin-wide RI/FS, Addendum 07, Residential Sampling to Support the
Human Health Risk Assessment. Prepared for USEPA by URS Greiner Inc. Seattle,
Washington. September 1999.
-. 1999c. Field Sampling Plan and Quality Assurance Project Plan Addenda for the
Bunker Hill Basin-wide RI/FS, Addendum No. 12. Prepared for USEPA by URS Greiner
Inc. Seattle, Washington. 1999.
-. 1999d. Field Sampling Plan and Quality Assurance Project Plan Addenda for the
Bunker Hill Basin-wide RI/FS, Addendum No. 13, School Yard/Daycare Sampling to
Support the Human Health Risk Assessment/Removal Actions. Prepared for USEPA by
URS Greiner Inc. Seattle, Washington. March 25, 1999.
-. 1999e. Short Sheet: IEUBKModel Bioavailability Variable. USEPA Technical Review
Workgroup for Lead. EPA 540-F-00-006, OSWER No. 9285.7-32. October 1999.
http://www.epa.gOv/superfund/programs/lead/prods.htm#short
. 1999f. National Recommended Water Quality Criteria-Correction. EPA 822-Z-99-
001. Office of Water. April 1999.
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1998a. Clarification to the 1994 Revised Interim Soil Lead Guidance for CERCLA Sites
andRCRA Corrective Action Facilities. EPA 540-F-98/030. OSWER Directive No.
9200.4-2P. August 1998.
-. 1998b. Draft Technical Work Plan for the Bunker Hill Basin-Wide RI/FS Panhandle
Region of Idaho Including Benewah, Kootenai, and Shoshone Counties. Prepared for the
USEPA Region 10 by URS Greiner, Seattle, WA, and CH2M HILL, Bellevue, WA. June
1998.
-. 1998c. Risk Assessment Guidance for Superfund: Volume 1 - Human Health Evaluation
Manual, Part D: Standardized Planning, Reporting, and Review of Superfund Risk
Assessments. Interim. EPA 540-R-97-033. January 1998.
-. 1998d. EPA Region 10 Interim Final Guidance: Developing Risk-based Cleanup
Levels at Resource Conservation and Recovery Act Sites in Region 10. EPA 910-R-98-
001. January 1998.
-. 1997a. Generic Field Sampling Plan and Generic Quality Assurance Project Plan for
the Bunker Hill Basin-wide RI/FS. Prepared for USEPA Region 10 by URS Greiner Inc.
Seattle, Washington.
-. 1997b. Exposure Factors Handbook. Volumes I—III. An Update to Exposure Factors
Handbook EPA 600/8-89/043. May 1989. EPA 600-P-95-002Fa. August 1997.
-. 1994a. Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective
Action Facilities. EPA 540/F-94/043. OSWER Directive No. 9355.4-12. Washington DC.
-. 1994b. Guidance for the Data Quality Objectives Process. EPA QA/G-4. September
1994.
-. 1993. Risk Assessment Guidance for Superfund. Volume I: Human Health Evaluation
Manual - Supplemental Guidance, Standard Default Exposure Factors for Central
Tendency and Reasonable Maximum Exposure. Draft.
-. 1992. Record of Decision (ROD) - Bunker Hill Mining and Metallurgical Complex,
Shoshone County, Idaho. September 1992.
-.1992. Community Relations in Superfund: A Handbook. Office of Emergency and
Remedial Response. EPA/540/R-92/009. January 1992.
-. 1991a. Record of Decision for Bunker Hill Superfund Site Populated Areas. U SEP A
Region 10, Kellogg, Idaho.
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Section 15.0
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. 1991b. A Guide to Principal Threat and Low Level Threat Wastes. OSWER 9380.3-
06FS.
. 1990a. Risk Assessment Data Evaluation Report (RADER) for the Populated Areas of
the Bunker Hill SuperfundSite. Prepared by TerraGraphics under USEPA Contract No.
68-W9-0008, WA #C10012: for USEPA Region 10 and Idaho Department of Health and
Welfare Division of Environmental Quality, Moscow, ID. October 1990.
. 1990b. Technical Support Document on Lead. Preparedfor Office of Solid Waste and
Emergency Response, Final Draft. Environmental Criteria and Assessment Office, Office
of Health and Environmental Assessment, Cincinnati, OH. ECAO Cin-747.
. 1990c. Air Quality Criteria for Lead: Supplement to the 1986 Addendum. Office of
Health and Environmental Assessment. Washington, DC. EPA 600/8-89/049F.
. 1989a. Human Health Risk Assessment: Protocol for the Populated Areas of the Bunker
Hill Superfund Site. Technical Enforcement, Support IV Contract Work Assignment
CI,0002. Contract No. 68-01-7351. Prepared by Jacobs Engineering, ICAIR, Life
Systems, Inc., and TerraGraphics Environmental Engineering.
. 1989b. Guidance Concerning Soil Lead Cleanup Levels at Superfund Sites. USEPA
Office of Solid Waste and Emergency Response. OSWER Directive No. 9355.4-02.
Washington, DC.
. 1989c. Risk Assessment Guidance for Superfund: Volume 1 — Human Health
Evaluation Manual. Part A. Interim Final. USEPA Office of Emergency and Remedial
Response. Washington, DC. EPA 540/1-89/002.
. 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies under
CERCLA. Interim Final. EPA 540/G-89/004. October 1988.
. 1986. Air Quality Criteria for Lead. Research Triangle Park, N.C.
U.S. Environmental Protection Agency and Idaho Division of Environmental Quality (USEPA
and IDEQ). 2000. Final Coeur d'Alene Basin Total Maximum Daily Load (TMDL)
Package. August 21, 2000.
. 1999. Memorandum of Agreement between the State of Idaho and the Environmental
Protection Agency for the Human Health Risk Assessment. Coeur dAlene Basin
Remedial Investigation and Feasibility Study. Prepared for USEPA Region 10. Seattle,
WA.
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Section 15.0
Page 15-11
U.S. Environmental Protection Agency Technical Review Workgroup for Lead. 2000. Review of
Human Health Risk Assessment for the Coeur d'Alene Basin. Washington, D.C.: USEPA,
OSWER, October 2000.
. 1999. Short Sheet: IEUBKModel Bioavailability Variable. EPA No. 540-F-00-006.
OSWER No. 9285.7-32.
von Lindern, I.H. 1982. A Modeling Technique to Simultaneously Evaluate In-Plant and Off-Site
Lead Emissions at a Primary Lead Smelter. National Institute of Occupational Safety and
Health, R.A. Contract Document No. 82-20. Taft Laboratory, Cincinnati, Ohio. June
1982.
. 1980. An Empirical Air Quality Analysis Utilizing Computer-Assisted Cartographic
Modeling Techniques. Ph.D. Dissertation, Yale University. 1980. Department of Forestry
and Environmental Studies. New Haven, CN.
van Winjen, J.H., et al. 1990. "Estimated Soil Ingestion by Children." Environmental Research
51:147-162, as cited in USEPA 1997b.
Washington State Department of Ecology Toxics Cleanup Program (Ecology). 1994. Natural
Background Soil Metals Concentrations in Washington State. Olympia, WA. Publication
No. 94-115. October 1994.
Wasserman, G.A., J.H. Graziano, P. Factor-Litvak, D. Popovac, N. Morina, A. Musabegovic, N.
Vrenezi, S. Capuni-Paracka, V. Lekic, E. Preteni-Redjepi, et al. 1994. "Consequences of
Lead Exposure and Iron Supplementation on Childhood Development at Age 4 Years."
Neurotoxicology and Teratology 16:233-40.
Wyman, S.A. 1993. The Potential for Heavy Metal Migration from Sediments of Lake Coeur
dAlene into the Rathdrum Prairie Aquifer Kootenai County, Idaho. Idaho Department of
Health and Welfare, Panhandle Health District, Coeur d'Alene. November 1993.
Yankel, A.J., I.H. von Lindern, and S.O. Walter. 1977. "The Silver Valley Lead Study: The
Relationship between Childhood Blood Lead Levels and Environmental Exposure."
Journal of Air Pollution. Control Association. 27:764-767.
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PART 3
RESPONSIVENESS SUMMARY
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Contents
Page iii
TABLE OF CONTENTS
1.0 OVERVIEW AND BACKGROUND ON COMMUNITY INVOLVEMENT 1-1
2.0 GENERAL COMMUNITY CONCERNS AND THEMES 2-1
2.1 HOW COMMUNITIES AND STAKEHOLDERS HAVE SHAPED THE
CLEANUP PLAN 2-7
2.1.1 Pre-Proposed Plan Responses to Community Input 2-7
2.1.2 Some Ways That the Proposed Plan and ROD are Responsive to
Community Concerns 2-7
2.2 COMMUNITY INVOLVEMENT ACTIVITIES CARRIED OUT BY
EPA IN RESPONSE TO REQUESTS 2-9
3.0 OVERVIEW RESPONSIVENESS SUMMARY 3-1
3.1 COMMUNITY RELATIONS AND COMMUNITY CONCERNS 3-1
3.1.1 Community Participation in Remedy Selection Process 3-1
3.1.2 Relationship Between Selected Remedy and Basin Environmental
Improvement Project Commission 3-2
3.1.3 Control of Cleanup Work 3-2
3.1.4 Role of Ombudsman 3-3
3.1.5 Job Opportunities 3-3
3.1.6 Need for Certainty and Closure 3-4
3.2 SITE DEFINITION AND FUNDING 3-5
3.2.1 Description of the Superfund Site 3-5
3.2.2 Funding for Cleanup in the Coeur d'Alene Basin 3-5
3.3 REMEDY SELECTION PROCESS 3-6
3.3.1 Description of an "Interim Measure" 3-6
3.3.2 Length of Time, Size, and Complexity of an Interim Measure 3-6
3.3.3 Relationship Between Remedy Selection Requirements and EPA
Guidance Documents 3-7
3.3.4 The Selected Remedy in Relationship to Ecological Alternative 3 3-8
3.3.5 The Selected Remedy in Relationship to a Natural Resource
Damages Restoration Plan 3-8
3.4 BACKGROUND METALS CONCENTRATIONS 3-9
3.4.1 Background Metal Concentrations Absent Mining Effects 3-9
3.4.2 Mining-Related Sources of Metals 3-10
3.5 REMEDIAL INVESTIGATION/FEASIBILITY STUDY 3-10
3.5.1 Scientific Adequacy of RI/FS, Including Risk Assessments, Versus
Need for Independent Study 3-10
3.5.2 Adequacy of Data Collected During RI/FS to Select and Design
Remedy 3-11
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3.6 REMEDY EFFECTIVENESS AND IMPLEMENTATION ISSUES 3-12
3.6.1 Remedy Effectiveness Estimates for Surface Water Quality 3-12
3.6.2 Remedy Performance for Ecological Protection 3-12
3.6.3 Estimated Times to Achieve AWQC and the Role of Natural
Recovery 3-13
3.6.4 Idaho TMDL for the Coeur d'Alene Basin 3-15
3.6.5 Relationship of Forest Management Practices to Recontamination
and Water Quality 3-16
3.6.6 Long-Term Protectiveness and Permanence of the Remedy 3-17
3.6.7 Scope of Lower Basin Sediment Removal 3-17
3.6.8 Scope of Remedies for Water Quality and Fish Habitat 3-18
3.6.9 Siting and Design of Repositories for Material Generated by
Cleanup Activities 3-19
3.6.10 Treatment of Surface Water from Canyon Creek 3-20
3.6.11 Effects of Nonmining Impacts on the Environment 3-22
3.7 SELECTED REMEDY FOR HUMAN HEALTH 3-22
3.7.1 Development of the Human Health Selected Remedy and EPA
National Guidance 3-22
3.7.2 Use of Blood Lead Observations in the HHRA and Development
of the Proposed Plan 3-24
3.7.3 The 2000-2001 Lead Health Intervention Program Blood Lead
Screening Results 3-27
3.7.4 Lead Based Paint and the Relationship to House Dust and Blood
Lead 3-29
3.7.5 Comparison of National Declines in Blood Lead Levels and Site-
Specific Conditions 3-30
3.7.6 Soil Lead Sampling and Particle Size 3-30
3.7.7 Bioavailability, Speciation, and the HHRA 3-31
3.7.8 Subtle Health Effects of Lead Exposure 3-36
3.7.9 Community Support for the Selected Human Health Remedy 3-37
3.8 ECOLOGICAL IS SUES 3-38
3.8.1 Cleanup Criteria 3-38
3.8.2 Waterfowl Issues 3-39
3.8.3 Fish Issues 3-40
3.8.4 Special-Status Species 3-41
3.8.5 Bull Trout 3-42
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TABLE OF CONTENTS (Continued)
3.9 COEUR D'ALENE LAKE 3-42
3.9.1 Relationship Between Selected Remedy and Coeur d'Alene Lake 3-42
3.9.2 Lake Management Plan 3-43
3.9.3 Potential for Release of Metals from Coeur d'Alene Lake Bottom
Sediments 3-43
3.10 BUNKER HILL BOX 3-44
3.10.1 Bunker Hill Box as Source of Metal Contamination 3-44
3.10.2 Relationship Between the Bunker Hill Box and the Selected
Remedy 3-44
3.11 UNION PACIFIC RAILROAD 3-45
3.11.1 UPRR Cleanup in Relationship to the Selected Remedy 3-45
3.12 SPOKANE RIVER 3-46
3.12.1 Anticipated Water Quality Conditions in the Spokane River 3-46
3.12.2 Sole-Source Spokane Valley-Rathdrum Aquifer 3-46
3.12.3 Cleanup Method for Sediments Behind the Upriver Dam 3-47
3.12.4 Remedies for Contaminated Sediments in Shoreline and
Depositional Areas 3-48
3.12.5 Protectiveness of Shoreline Remedies 3-48
3.12.6 PCBs in Sediments 3-49
3.13 MONITORING 3-50
3.13.1 Monitoring as Part of the Selected Remedy for Ecological
Improvement 3-50
3.13.2 Monitoring of Fish in Coeur d'Alene Lake and the Spokane River 3-50
4.0 RESPONSES TO INDIVIDUAL COMMENTS 4-1
TABLES
3.7-1 Summary Statistics for Environmental Variables for Two Data Sets
3.7-2a IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic
Area, Ages 9-84 Months: Default and 40:30:30 - with repeat observations
3.7-2b IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic
Area, Ages 9-84 Months: Default and 40:30:30 - without repeat observations
3.7-3a IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-60 Months: Default and 40:30:30 - with repeat observations
3,7-3b IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-60 Months: Default and 40:30:30 - without repeat observations
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3,7-4a IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-24 Months: Default and 40:30:30 - with repeat observations
3,7-4b IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area,
Ages 9-24 Months: Default and 40:30:30 - without repeat observations
3,7-5a General Linear Model and Regression Coefficients for Blood Lead and
Environmental Sources - with repeat observations
3,7-5b General Linear Model and Regression Coefficients for Blood Lead and
Environmental Sources - without repeat observations
3.7-6 Blood Lead Declines in National Surveys, Smelterville, and Kellogg
4-1 Individual Comments and Responses Organized by Name of Person Providing
Comment
4-2 Referenced Responses Organized in Numerical Order
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1.0 OVERVIEW AND BACKGROUND ON COMMUNITY INVOLVEMENT
On October 29, 2001, EPA released the Coeur d'Alene Basin Proposed Plan for public review.
The plan described EPA's Preferred Alternative for cleaning up mine waste contamination in the
Basin. The plan described a suite of activities aimed at protecting human health and the
environment. The activities in the plan are estimated to take 30 years and cost $359 million. The
comment period was extended twice in response to public requests, for a total of 120 days, and
officially closed on February 26, 2002. EPA also held four public meetings in the Basin during
the comment period to allow people to make oral comments for the record. The meetings were
held in Wallace, Idaho on November 13, 2001, Cataldo, Idaho on November 14, 2001,
Coeur d'Alene, Idaho on November 15, 2001, and Spokane, Washington on November 19, 2001.
EPA's preparation of the Responsiveness Summary conforms to the intent of EPA guidance,
including: OSWER Directive No. 9230.0-06, SuperfundResponsiveness Summaries and
Community Relations in Superfund: A Handbook, and the Superfund Community Involvement
Handbook. The Responsiveness Summary provides information about the views of the public,
government agencies, the support agencies, and potentially responsible parties (PRPs) regarding
the proposed remedial action and other alternatives. Further, it documents how comments have
been considered during the decision-making process and provides answers to all significant
comments. Section 1 presents an overview and background on community involvement.
Section 2 provides an overview of the general community concerns and themes expressed during
the comment period and EPA's responses. Section 3 presents an overview responsiveness
summary that addresses the commenters' major issues and concerns, by subject, including those
raised by the local communities. Section 4 presents comprehensive responses to each of the
individual comments that EPA received on the Proposed Plan.
In total, EPA received more than 3,300 comments on the Proposed Plan from approximately
1,300 commenters. EPA sent copies of all comments received to the states of Idaho and
Washington, the Coeur d'Alene and Spokane tribes, and the federal natural resource trustees.
EPA reviewed all the comments, in consultation with the regulatory stakeholders, to determine
what, if any, changes were appropriate to the Preferred Alternative identified in the Proposed
Plan. Based on this evaluation of the comments, both minor changes and significant differences
from the Preferred Alternative are reflected in the Selected Remedy of the ROD.
This Responsiveness Summary is a continuation of EPA's extensive efforts to involve
stakeholders and community members in the remedy selection process. EPA's community
involvement efforts during the remedial investigation/feasibility study (RI/FS) far exceed those
required by the National Contingency Plan (NCP). One of the ways EPA worked to ensure early
community input was to provide four public review periods at various stages of the Proposed
Plan in addition to the required comment period on the Proposed Plan. People in the Basin
reviewed and commented on the remedial investigation, the human health risk assessment, the
ecological risk assessment, and the feasibility study for the Basin as summarized below.
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Document
Public Re\ie\\
Dsile <>l' l-'iiiiil Report
Draft Lcological Risk draft
Assessment
August 2UUU lo \o\cmlvr 2UUU
Ma) 2UU1
Draft Human Health Risk
Assessment
July 2000 to October 2000
July 2001
Draft Remedial Investigation
October 2000 to March 2001
October 2001
Draft Feasibility Study
December 2000 to April 2001
October 2001
EPA also prepared written responses to comments on each of these documents. These responses
are included in the Administrative Record for the site. Additional information on public
involvement in the remedy selection process is presented in Section 3 of Part 2 of this ROD.
Because EPA worked intensively to involve community members and all levels of government
affected by the cleanup throughout the RI/FS process and during the development of the
Proposed Plan, input from these groups was incorporated into the Preferred Alternative prior to
the Proposed Plan being released for public comment. Therefore, the Selected Remedy in this
ROD is not substantially different from the Preferred Alternative. Since the release of the
Proposed Plan, EPA has been working with the governments and communities to address
remaining concerns, but these have been largely related to clarifying the scope and cost of the
Selected Remedy, not specific cleanup actions or alternatives.
References used in this Responsiveness Summary are listed in Part 2, Section 15.0 of this ROD.
Acronyms and abbreviations are also listed in Part 2 of this ROD.
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2.0 GENERAL COMMUNITY CONCERNS AND THEMES
As with the four earlier review periods, a broad range of opinions was represented in the public
comments on the Proposed Plan. Many of the more than 3,300 comments on the Proposed Plan
were a result of organized efforts by citizen groups, and came in the form of postcards, form
letters, a paid newspaper multiple choice survey and e-mail campaigns. A breakdown of the
1,317 individual submissions received follows:
l.cller
lliiiiiil
Newspaper
Sii r\ e\
PoslCiinl
Public
Teslimnm
loliil
368
89
221
568
71
1,317
Many of these comments addressed general, overarching concerns about the cleanup and about
EPA, though some of the form letters did address specific cleanup alternatives. Most of these
general comments were similar to comments EPA received during the four earlier review
periods.
Some of the general comments expressed a lack of trust and support for EPA and other
government agencies. Other comments generally expressed the belief that cleanup is not needed
in the Basin and stated a desire for EPA to stop work and leave the Basin. Other comments
generally supported EPA's plan and expressed a desire for an even more aggressive cleanup
approach.
EPA worked with community residents, including local elected officials and community leaders,
over the last several years to understand and address these overarching concerns during the study
and cleanup planning process. However, the things some people are most concerned about, such
as the boundaries of the Superfund site and EPA's statutory obligation to protect human health
and the environment are outside the scope of EPA Region 10's authority. These issues are
matters of statute or regulation and include some that have been the subject of court decisions.
Because EPA could not address these issues in the RI/FS or Proposed Plan, some people feel that
EPA has not listened to them, and they are not satisfied that the cleanup plan addresses their
concerns.
Below is a brief summary of some of these general community concerns and how EPA has tried
to address these concerns if possible.
General comment: Concern that the human health risks (particularly in the residential
areas of the Upper Basin) have been overestimated and that residential cleanups are not
necessary.
Some people expressed concern about the way the State of Idaho and EPA assessed the human
health risks in the Basin and believe that the risks have been overestimated. Many of these
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people believe that because they have not seen children who appear to have lead poisoning, they
believe no health emergency exists and therefore cleanup in residential areas is not necessary.
However, other people have stated they feel that EPA's cleanup plan doesn't go far enough to
protect children and that more should be done.
Response: EPA and the State of Idaho have been working with the communities in the Upper
Basin on human health issues for several years. These communities will be the most affected by
the cleanups in residential areas. It is understandable that people living in these communities
may question the need for cleanup of residential soils containing lead since the effects of lead
exposure in children are usually not obvious. People are understandably concerned that their
communities may be unfairly stigmatized as unsafe or unhealthy and that people from outside the
area will not want to visit or relocate to these communities.
This has been a difficult issue to address. EPA and the State of Idaho have stated that a primary
goal for cleanup in the Basin is preventing children from being exposed to lead. This is a
fundamentally different approach from treating children and conducting cleanups after children
exhibit elevated blood-lead levels or other obvious symptoms of lead exposure. EPA and the
State of Idaho followed existing national protocols for conducting risk assessments and
establishing soil cleanup standards that are protective of children living in the area now, and
those that may live there in the future. The risk assessment clearly indicates that the mining-
related waste continues to be a health hazard, especially for young children and pregnant women.
Early on in the RI/FS process, in response to public requests, EPA transferred the lead for
conducting the human health risk assessment for the Basin to the State of Idaho. The State
followed national guidelines and policies for conducting lead risk assessments and establishing
soil cleanup levels. The risk assessment was extensively peer reviewed by national experts.
EPA and the State believe the science used in the risk assessment is sound. In April 2001, in
response to requests from the communities and in an attempt to address questions and concerns,
EPA participated in a "Science Summit" sponsored by the Shoshone Natural Resources
Coalition's Science Committee. To support the Science Summit, EPA arranged for local,
regional, and national lead remediation experts to attend and present information and respond to
questions. The Science Summit helped the agencies understand the communities' questions and
concerns.
Recently, the Idaho congressional delegation requested a National Academy of Sciences (NAS)
review of the scientific and technical analyses that form the basis of the ROD's Selected
Remedy. The NAS agreed to conduct the review if it receives an estimated $840,000
appropriation to do so. If the NAS conducts a review, EPA will evaluate the results of the
review and determine if changes to the ROD are needed.
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General comment: Concern about government actions on private property and disruption
to the communities during cleanup.
Some people expressed concern about government actions on private property and cleanup work.
Response: EPA cannot access or take action on private property without permission from the
owner or explicit legal authority to do so. For example, the ROD calls for sampling and cleanup
of residential properties in the Upper Basin. Before any work occurs, EPA or the appropriate
state or local agency will talk with each property owner and request written permission to sample
and/or conduct cleanup work on their property.
In response to concerns about large-scale removal of contaminated material, the ROD calls for
more limited removals of "hot spots" of contamination and focuses on treatment technologies
that will be less invasive and disruptive to communities. In addition, EPA and other agencies will
work closely with individual property owners and local governments to minimize disruption of
normal day-to-day activities during cleanup. Whenever possible, work will be scheduled so that
it does not interfere with community activities or with an owner's plans for the property. In
addition, at residential properties, EPA and the State of Idaho will attempt to protect existing
landscaping or will replace trees, shrubs, and plants that may be damaged during cleanup work.
General comment: Concerns about the local economy.
Some people expressed serious concerns about the economic conditions in the Basin and
potential negative effects of a Superfund cleanup.
Response: EPA shares the concern for the economy in the Basin. In the long-run, however,
EPA and the State of Idaho anticipate that cleanup will improve socioeconomic conditions in the
Basin. Basin-wide sampling, analysis, and remediation of soil in residential proprieties will
provide property owners the information necessary for lead disclosures required for property
transactions. Other aspects of the remedy, such as establishing vegetative cover, remediating
schoolyards, rights-of-way and commercial property, and providing drainage improvements to
protect the remedy, will be coordinated with paint abatement programs and community
redevelopment projects and will have the potential to make the communities more attractive
locations for business. The work associated with implementation of the Selected Remedy may
provide additional jobs for the local labor force and contractors, including local supply
contractors. Additionally, remediation dollars spent in the Silver Valley may create other
opportunities for local businesses.
Of $95 million federal contract dollars spent on cleanup in the Bunker Hill Box between 1995
and 2000, $42 million were spent locally. This includes local labor, materials, rentals, taxes and
utilities. In addition, EPA has provided $200,000 in grant monies for economic redevelopment
in the Silver Valley, and will continue to provide this kind of support when possible. Cleanup
work will be coordinated with local land use planning and community infrastructure needs. In
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addition, the Basin Environmental Improvement Project Commission will work to ensure that as
many local people and businesses as possible are involved in the cleanup work within the bounds
of federal contracting and procurement rules.
General comment: Concerns about the boundaries of the Superfund site.
Some people expressed concern and confusion about the extent of the boundaries of the
Superfund site in the Basin. Some people believe that EPA has illegally expanded the
boundaries of the Superfund site. People are also concerned about the possible stigma associated
with being part of a Superfund site.
Response: Such issues have been major community concerns in the Basin throughout
development of the RI/FS and Proposed Plan. These have been very difficult for EPA to address
to some people's satisfaction. The definition of a Superfund site provided by the CERCLA
statute includes areas where hazardous substances are found or have come to be located. In
conducting its work in the Basin, EPA has complied with this definition.
However, some people in the Basin communities believed that the cleanup work in the Basin
would be limited to the area near Kellogg and Smelterville, referred to as the Bunker Hill "Box"
(the Box). Given this, it is understandable that people would be concerned when the
investigation and cleanup work began in areas outside the Box. Unfortunately, the mine waste
contamination in the Basin extends far beyond the boundaries of the Box, both upstream and
downstream. The contamination outside the Box continues to pose significant risks to both
people and the environment. While the mine waste contamination does exist in areas outside the
Bunker Hill Box, the contamination is not present, as some people apparently believe, over the
entire 1,500 square-mile watershed. The areas where contamination exists are primarily near
historical mining operations; in some of the residential and commercial areas of the Upper Basin;
in and near the affected parts of the Coeur d'Alene River system; and other downstream areas
where contamination exists. Consequently, areas such as those above the floodplain where
contamination does not exist are not included in the site. For example, the residential areas of
the cities of Coeur d'Alene, Post Falls, and Harrison are not considered part of the site.
While EPA cannot change the definition of a Superfund site, EPA is trying to address "stigma"
concerns in two ways. One way is to better define the areas where cleanup work is needed and
where it is not needed. The ROD describes the cleanup actions in each part of the Basin and
provides a map showing these areas. In addition, EPA is committed to removing the Superfund
designation from clean areas as quickly as possible. Communities will not have to wait until all
of the cleanup work in the Basin is complete in order to be removed from the site. Specifically,
the goal is to complete cleanup work in the Upper Basin communities first, so that these areas
can be removed from the Superfund site as quickly as possible.
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The Selected Remedy does not include remedial actions for Coeur d'Alene Lake. State, tribal,
federal, and local governments are currently in the process of implementing a Lake Management
Plan outside of the Superfund process using separate regulatory authorities.
General comment: State and Local governments should have control of cleanup work.
Some people expressed the desire for the State of Idaho and the new Coeur d'Alene Basin
Environmental Improvement Project Commission (the Basin Commission) to have the lead role
in implementing the cleanup plan for the Basin. Other commenters felt that because the
contamination and cleanup work cross the Washington state line and affect tribal land, the
federal government should have the lead role in making sure an effective cleanup is carried out
across these jurisdictions.
Response: EPA recognizes that in order to have a successful and sustainable cleanup in the
Basin, all the governments affected will need to be directly involved in implementing the
cleanup actions outlined in the ROD. Starting early on in the RI/FS process, EPA worked
closely with state, tribal and local governments, as well as the other federal agencies with
authorities in the Basin. EPA has provided significant funding to many of these governments to
allow them to fully participate in the process.
EPA will continue to work in a collaborative way with all levels of government during the next
phases of cleanup. State legislation under the Basin Environmental Improvement Act
established the process for the formation of the Basin Commission. The Basin Commission
includes federal, state, tribal, and local governmental involvement. EPA will participate as a
member of the Basin Commission for implementation of the ROD and development of priorities
and sequencing of cleanup activities. Although the Commission will have an important role in
implementing the cleanup in Idaho, EPA will continue to have overall responsibility to ensure
that cleanup meets the requirements of the ROD and of CERCLA. EPA also has a legal
obligation to work with the State of Washington to implement the cleanup actions outlined for
the Spokane River.
General comment: Concern about contamination migrating downstream and re-
contaminating clean areas.
People expressed concern about the continued movement of contamination from the Upper Basin
to the Lower Basin and from Idaho into the State of Washington. People were also concerned
about the potential for cleanup activities to cause contaminants to move downstream and re-
contaminate clean areas.
Response: Much of the work described in the ROD is intended to significantly reduce the
amount of contamination moving downstream. When implementing the cleanup, EPA will work
with the Commission to evaluate which cleanup work should be done first and how to reduce the
possibility of re-contaminating clean areas. The ROD calls for removing up to 12 percent of the
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total of contaminated riverbed sediments in the Basin. EPA and any other party doing work in
the river or lakes must comply with existing environmental laws and minimize downstream
movement of contaminants.
General comment: Concern that EPA should select a more aggressive cleanup alternative.
Some people commented that EPA should select a more aggressive cleanup approach which
would provide additional protection of human health and the environment.
Response: The Selected Remedy includes prioritized actions to provide significant
improvements both for human health and the environment in the Basin. The Selected Remedy
will be evaluated for its protectiveness at least every five years as required by CERCLA. If the
remedy is not found to be adequately protective, measures will be evaluated and implemented to
ensure the remedy is protective, consistent with the ROD.
General comment: Concern about the cost of cleanup and the estimated length of time
needed to clean up the Basin.
People were concerned about how long cleanup will take and EPA's proposed "incremental
approach." These people were concerned that the incremental approach provides no certainty
about when the cleanup will be finished and when the Superfund designation can be removed
from the Basin. People were also concerned that the estimated cost for complete cleanup in the
Basin, as estimated in the Proposed Plan, was over $1 billion.
Response: It is true that given the amount and extent of mine waste contamination remaining in
the Basin, cleanup will be costly and will take many years. The work described in the ROD is
estimated to cost $359 million and take approximately 30 years to complete. Cleanup work to
protect human health in the communities and residential areas is a top priority for completion.
Cleanup of these areas will be conducted concurrently with the ecological remedy. EPA's
expectation is that the human health remedy will be completed well before the approximately 30-
year timeframe for completing the ecological remedy. EPA is not proposing a cleanup plan that
costs in excess of $1 billion. However, EPA has indicated that it is likely that additional work
beyond that described in the ROD will be needed.
EPA estimated, based on existing information, that environmental cleanup work under
Alternative 3 in the Proposed Plan would cost $1.3 billion. However, no decision has been made
regarding specific future work, and any additional work beyond that described in this ROD will
have to undergo a public process including another Proposed Plan and a public review and
comment period.
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2.1 HOW COMMUNITIES AND STAKEHOLDERS HAVE SHAPED THE
CLEANUP PLAN
EPA involved all of the various levels of government and the affected communities in the Basin
throughout the process. Because of this inclusive and collaborative approach, EPA was able to
incorporate the suggestions made in public comments in "real time" as the studies were
happening, while documents were being written and as the Preferred Alternative and Selected
Remedy were being developed. Below is a list of some of the ways EPA was able to respond to
community concerns during the RI/FS, Proposed Plan, and ROD development process.
2.1.1 Pre-Proposed Plan Responses to Community Input
• Expedited sampling of Coeur d'Alene Lake beaches was conducted in 1998 (on
request from the mayor of Coeur d'Alene). Result: beaches were declared safe)
• The method for drawing children's blood was changed from venous to finger stick
• Voluntary sampling and cleanups have been conducted since 1998 in the Upper
Basin (104 residences and common areas cleaned up, 37 residences provided with
clean source of water, and more than 300 residences sampled)
• The list of plants and animals evaluated in the ecological risk assessment was
changed based on local landowners input, thus changing the scope of the
assessment and making it more site-specific
• EPA provided direct funding to Coeur d'Alene, Post Falls, Harrison, and
Kootenai County, as well as Shoshone County so that those localities could hire
technical consultants to review EPA's work and provide input prior to the release
of the Proposed Plan
• EPA provided direct funding for economic development in the Silver Valley
• EPA gave the State of Idaho the lead role in conducting the human health risk
assessment for the Basin
• EPA tailored the screening risk assessment for the Spokane River beaches to the
community's specified uses
2.1.2 Some Ways That the Proposed Plan and ROD are Responsive to Community
Concerns
• The Proposed Plan actions are closely in line with the recommendations from the
State of Idaho's Consensus Building Process
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The cleanup plan will minimize disruption to communities during cleanup by
limiting the amount of "digging and hauling" of material in a given year and
emphasize treating contamination in place where possible
EPA is supporting the State of Idaho's YES program for yard cleanups
EPA has been working with local agricultural landowners on creative wetland
cleanup options which will benefit the landowner and assist with the cleanup
(Lower Basin)
No relocation of residents is currently planned for Burke Canyon based on input
from local residents
The cleanup plan includes more flexibility in reaching cleanup standards in
residential areas, i.e., "community greening," by using barriers such as vegetation
on contaminated yards between 700 and 1,000 parts per million (ppm) lead
instead of excavating and replacing soil between 700 and 1,000 ppm lead. This
will result in less disruption and fewer yards having soil removed and replaced
The cleanup plan will include improvements to protect the remedy (e.g., drainage
improvements) and cleanup work will be coordinated with local land use planning
efforts
Cleanup in communities will be a top priority so that clean areas can be removed
from the Superfund list as quickly as possible
EPA will participate as a member of the Basin Environmental Improvement
Project Commission to implement the ROD
The Selected Remedy does not include remedial actions in Coeur d'Alene Lake.
State, tribal, federal, and local governments are currently in the process of
implementing a Lake Management Plan outside of the Superfund process using
separate legal authorities
No wetlands in the Lower Basin will be used as disposal sites
No disposal of material or dredging in Coeur d'Alene Lake is included in the
plan.
The cleanup plan will be tailored to minimize long-term operations and
maintenance costs which will result in less cost to the states
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• Local waste repositories have been and will continue to be sited and designed
with local community input
• Spokane River cleanup areas are based on input from State of Washington,
Spokane Tribe, community, and other interested parties
2.2 COMMUNITY INVOLVEMENT ACTIVITIES CARRIED OUT BY EPA IN
RESPONSE TO REQUESTS
Below is a list of community involvement activities carried out by EPA in response to requests:
• Monthly NewsBriefs
• Executive Summaries of documents
• Weekly technical conference calls open to the public
• Four educational workshops on Human Health and Ecological Risk Assessments,
Remedial Investigation and Feasibility Study
• Public review periods and comment responses provided on the HHRA, Ecological
Risk Assessment, and RI/FS (all review periods were extended upon request)
• Extended Proposed Plan comment period to 120 days on request
• Supported the "Science Summit" by bringing national and regional experts on
lead risks and cleanups to the Silver Valley
• Provided support for a "health fair" in the Silver Valley
• Staff support for CAC RI/FS Task Force for two and a half years
• Top regional and national EPA managers have visited the Basin at least 16 times
on request
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3.0 OVERVIEW RESPONSIVENESS SUMMARY
3.1 COMMUNITY RELATIONS AND COMMUNITY CONCERNS
3.1.1 Community Participation in Remedy Selection Process
Comment Summary:
Some comments questioned whether EPA has done enough to ensure community participation in
the technical investigation and remedy selection processes and whether community input was
used as opposed to merely being noted.
EPA response:
Community acceptance is one of nine criteria that EPA considers, by regulation, in its remedy
selection process. Community acceptance played an early and significant role in selecting the
remedy. As described in detail in Section 3.0 of Part 2 of the ROD, EPA has provided a wide
range of opportunities for community participation in the investigation and remedy selection
processes within the Coeur d'Alene Basin including four additional public review periods. EPA
is required by CERCLA to provide opportunities for community participation, and the extensive
efforts in the Coeur d'Alene Basin go far beyond the required activities and rival any that have
ever been taken in the United States by EPA.
As noted previously, some of the community comments and concerns are outside of EPA's
authority. EPA has worked with the communities in the Basin to respond to these concerns, but
some people still do not feel EPA has listened or adequately addressed all of their concerns.
Part of the community participation effort in the Basin was the State of Idaho's Basin Consensus
Building Process. This effort was initiated in September 2000 and continued until March 2001,
with the State of Idaho in the lead role and EPA in a support role. A wide variety of stakeholder
entities, both governmental and community, participated. The purpose of the process was to
identify "common ground" or points of divergence for EPA to use in developing a cleanup plan.
Considerable discussion focused on four prominent issues for cleanup:
• Tailings along the South Fork and its tributaries in the floodplain and on uplands that
are major sources of zinc in the water
• Banks and beds of the Coeur d'Alene River that are a major source of lead in the
water
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• Floodplains along the river from Cataldo to Harrison that are a source of lead
exposure to wildlife
• Sources of lead, including soil, indoor dust, and house paint, in communities that may
be an exposure source to children
Because this process occurred while EPA was developing remedial alternatives as part of the
Feasibility Study, EPA had the benefit of considering and incorporating the outcome of the
consensus building process into the development of the Proposed Plan.
3.1.2 Relationship Between Selected Remedy and Basin Environmental Improvement
Project Commission
Comment Summary:
Some comments supported the formation of the Basin Environmental Improvement Project
Commission or some form of local control over cleanup and recommended EPA turn over
control of cleanup to that group.
EPA response:
EPA anticipates working as a member of the new Basin Environmental Improvement Project
Commission and looks forward to finding innovative means to cleanup the Basin and create job
opportunities, while meeting statutory requirements for cleanup.
3.1.3 Control of Cleanup Work
Comment Summary:
Some comments questioned who would be in control of cleanup, ranging from support for EPA
control to turning over control to others, and questioned what EPA's role would be in the
cleanup.
EPA response:
EPA recognizes that in order to have a successful and sustainable cleanup in the Basin, all the
governments affected will need to be directly involved in implementing the cleanup actions
outlined in the ROD. EPA is fully committed to working cooperatively with the States of Idaho
and Washington, the Coeur d'Alene and Spokane Tribes, the Federal Natural Resource Trustee
Agencies, and the local governments in the Basin to implement the cleanup. In addition, EPA is
supportive of the appropriate state, tribal and local entities taking the lead in implementing parts
of the ROD in a manner consistent with the statutory obligations EPA has under Superfund.
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3.1.4 Role of Ombudsman
Comment Summary:
Several comments expressed the opinion that the Office of the National Superfund Ombudsman
should be allowed to complete its work and continue to conduct its duties during the Basin
cleanup action.
EPA response:
EPA has cooperated and will continue to cooperate with the Office of the National Superfund
Ombudsman in its investigation. In September and October 2001, Region 10 provided written
responses to Ombudsman interrogatories related to the Bunker Hill/Coeur d'Alene Basin
investigation, and has made sure that the Office of the Ombudsman was aware of the schedule
for the Proposed Plan and the ROD. To date, EPA has received no recommendations or reports
from the Ombudsman. On December 18, 2001, the Ombudsman office sent a 2-page document
entitled "Working Findings for Discussion and Comment" to the "Service List for National
Ombudsman Investigation" and the local press. The December 18 memo was not sent to EPA
Region 10, nor was a response requested by the Ombudsman. However, EPA has reviewed the
memo and has determined that it contains no specific recommendations regarding this Selected
Remedy. EPA responded to the working findings in a July 16, 2002 letter to U.S. Senator Mike
Crapo. If EPA receives final recommendations from the Office of the Ombudsman, it will
evaluate them and take appropriate actions. If EPA determines that substantial changes to the
ROD are appropriate based on the Ombudsman recommendations, such changes would be
subject to additional public review and comment.
3.1.5 Job Opportunities
Comment Summary:
Many comments questioned what economic impact the Selected Remedy will have on local areas
of the Basin and stressed the need for a healthy economy and local hiring in the cleanup.
EPA response:
EPA shares the concern for the economy in the Basin. Of the $95 million in federal contract
dollars spent on cleanup in the Bunker Hill Box between 1995 and 2000, $42 million were spent
locally. This includes local labor, training materials, rentals, taxes and utilities. To date, EPA
has provided $200,000 in grant monies for economic redevelopment in the Silver Valley. EPA
will continue to provide this kind of support when possible and will make sure that cleanup work
is coordinated with local land-use planning and community infrastructure needs. EPA is
required to comply with Federal Acquisitions Requirements, including providing for full and
open competition. EPA encourages local businesses to be involved with the cleanup work and
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believes the cleanup work of the Selected Remedy will provide a significant number of jobs to
local residents while benefiting the local economy. EPA is committed to assisting with
economic development to the extent possible, and supports local hiring whenever and wherever
possible.
3.1.6 Need for Certainty and Closure
Comment Summary:
Many comments stated that "certainty" and/or "closure" related to the cleanup is needed for the
economic well-being of the Basin. People were concerned about effects on business
development, the ability to complete property transactions, and property values. The comments
called for clear identification of the duration of cleanup, of which areas require cleanup and
which do not, and of cleanup costs.
EPA response:
The Selected Remedy does include certainty regarding human health protection within
community areas and those recreational areas prioritized for cleanup. Cleanup of these areas is a
top priority and will be completed well before the 30-years described for the ecological portion
of the Selected Remedy. Property owners in the Basin will be able to request soil sampling
necessary for lead disclosures required for property transactions, and the results will be made
available to them in a timely manner. The length of time required for cleanup in the
communities will depend on the availability of funding and the participation of property owners.
Although future funding is not a certainty to date, the Bunker Hill/Coeur d'Alene Basin work has
been a priority for funding.
As described extensively in the Proposed Plan and the ROD, complete certainty with respect to
the environmental cleanup is not possible at this time. Sufficient information exists to support
the Selected Remedy. However, insufficient information exists to characterize all the specific
sources of metals contamination impacting the streams and floodplains, as well as the anticipated
effectiveness of certain remedial actions, in some areas of the Basin. The Selected Remedy
includes prioritized cleanup actions that are expected to take approximately 30 years to
implement. During the five-year review process and at the end of this approximately 30-year
period, EPA will evaluate and decide whether any additional CERCLA remedial actions are
necessary to attain ARARs or to provide for the protection of human health and the environment,
and whether any ARAR waivers should be applied.
Although complete certainty is not possible at this point for the environmental protection portion
of the Selected Remedy, actions taken will be in defined locations and will be designed to
achieve specific benchmarks. Areas included in the cleanup are specifically identified in maps
included in the ROD. These areas are in and near historical mining operations, the affected parts
of the Coeur d'Alene River system, and other downstream areas where contamination has come
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to be located. Consequently, areas such as those above the floodplain where contamination does
not exist, and where most economic development opportunities exist, are not included in the
environmental cleanup.
The estimated present worth cost of the Selected Remedy is $359 million. Consistent with EPA
RI/FS guidance, the accuracy of this cost estimate is -30 to +50 percent.
3.2 SITE DEFINITION AND FUNDING
3.2.1 Description of the Superfund Site
Comment Summary:
Some comments questioned what the Superfund site is, whether EPA has illegally expanded it,
and whether the definition of the site means EPA will be taking actions in all parts of the Basin.
EPA response:
The term "site" is derived from the CERCLA definition of a "facility." Section 101 (9) of
CERCLA states that "[T]he term 'facility' means.. .any site or area where a hazardous substance
has been deposited, stored, disposed of, or placed, or otherwise come to be located." The site
was listed on the National Priorities List (NPL) in 1983 and has a CERCLIS identification
number IDD048340921. The listing of the site reflected widespread contamination caused by
mining and mining-related activity. Consistent with EPA policy, the listing did not set forth any
site boundaries. In June 2000, the United States 9th Circuit Court of Appeals vacated a site
decision by the U.S. District Court limiting the scope of the NPL facility to the 21-square miles
known as the Bunker Hill Box. This decision left standing the EPA position that the NPL
facility includes all areas of the Coeur d'Alene Basin where mining contamination has come to
be located. Hence, consideration of cleanup actions outside the Box does not constitute
expansion of the site. Areas where mining contamination has come to be located, some of which
are addressed in this ROD, are primarily near historic mining operations; in some of the
residential and commercial areas of the Upper Basin; parts of the Coeur d'Alene River system;
and other downstream areas where contamination has come to be located. Consequently, areas
such as those above the floodplain which are unaffected by contamination from mining are not
included as part of the site.
3.2.2 Funding for Cleanup in the Coeur d'Alene Basin
Comment Summary:
Some comments questioned what source(s) of funding will be available for the cleanup.
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EPA response:
The CERCLA statute and the NCP regulations provide EPA with the authority to take actions to
protect human health and the environment. EPA's ability to carry out this mandate is subject to
the availability of funds. EPA will consider all funding sources available, including the
Superfund and judgments against responsible parties to carry out necessary cleanup actions.
Currently, EPA's Superfund budget is appropriated annually from Congress.
3.3 REMEDY SELECTION PROCESS
3.3.1 Description of an "Interim Measure"
Comment Summary:
Some comments questioned what an "interim action" (referred to in the ROD as an "interim
measure") is in the context of CERCLA.
EPA response:
EPA implements CERCLA cleanups (response actions) through removal and remedial actions.
The regulation that governs the implementation of CERCLA is the National Contingency Plan
(NCP). The Selected Remedy in this ROD for the Coeur d'Alene Basin is a "remedial" action.
The "threshold criteria" set forth in the NCP at Sec.300.430(f)(l)(i)(A) for selection of remedies
are "overall protection of human health and the environment and compliance with ARARs
(unless a specific ARAR is waived)." A remedial action, such as the one selected in this ROD,
which does not meet ARARs, but will become part of a total remedial action that will attain
ARARs, is defined as an "interim measure" by the NCP (Sec. 300.430(f)(l)(ii)(C)(l)). Because
EPA cleanups are termed "response actions" by the NCP, EPA often uses the term "interim
action," such as it did in the Proposed Plan and as the NCP does, to refer to an interim measure
such as the Selected Remedy.
3.3.2 Length of Time, Size, and Complexity of an Interim Measure
Comment Summary:
Some comments questioned whether it was appropriate for EPA to use an interim measure
approach to cleanup, considering the lengthy estimated time for cleanup, the size of the site, and
its complexity.
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EPA response:
CERCLA does not place restrictions on the use of interim measures based on the time necessary
to remediate a site or its size or complexity. Instead, the NCP provides discretion to EPA to
determine where interim measures are appropriate. As described in the ROD, an adaptive
management strategy or incremental approach using interim measures makes sense for cleanup
of the Coeur d'Alene Basin. Although overall cleanup times are estimated to be lengthy, the
Selected Remedy will produce ongoing incremental human health and environmental
improvements over the estimated 30 years. Cleanup work to protect human health in the
communities and residential areas is a top priority. Cleanup of these areas will be conducted
concurrently with the ecological remedy. EPA's expectation is that the human health remedy
will be completed well before the approximately 30-year timeframe of the ecological remedy.
Conversely, reduction of dissolved metals until Ambient Water Quality Criteria (AWQC) are
met, will occur over long periods of time. The geographic extent of areas requiring cleanup and
the complexity of the sources of contamination support the use of an adaptive management
approach to cleanup. By using information from CERCLA-required five-year reviews and other
processes, the effectiveness of any future increments of cleanup can be optimized.
3.3.3 Relationship Between Remedy Selection Requirements and EPA Guidance
Documents
Comment Summary:
Some comments questioned whether EPA strictly adhered to its guidance document in
developing the Proposed Plan and selecting a remedy.
EPA response:
EPA's selection of remedies is governed by the requirements of CERCLA and the NCP
regulations that implement CERCLA. EPA complied with these requirements in selecting a
remedy in this ROD. EPA's guidance document for preparing remedy selection decision
documents is "A Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other
Remedy Selection Decision Documents" which was published in July 1999. The "Notice" on
the first page of this document states: "This document provides guidance to EPA and State
staff..." The document does not, however, substitute for statutes EPA administers nor their
implementing regulations, nor is it a regulation itself. Thus it does not impose legally-binding
requirements on EPA, States, or the regulated community, and may not apply to a particular
situation based upon the specific circumstances." EPA used the guidance, as appropriate, to
assist it in preparing the Proposed Plan and the ROD.
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3.3.4 The Selected Remedy in Relationship to Ecological Alternative 3
Comment Summary:
Some comments questioned whether EPA is selecting Ecological Alternative 3 as the remedy in
this ROD.
EPA response:
The Selected Remedy in this ROD is not Ecological Alternative 3. EPA is using an adaptive
management strategy to implement cleanup. The Selected Remedy includes the complete
remedy needed to protect people from exposure to contamination that currently occurs in the
community and residential areas and identified recreational areas of the Upper Basin and Lower
Basin, as well as at Spokane River recreational sites upstream of Upriver Dam. For
environmental protection, the Selected Remedy includes approximately 30 years of prioritized
actions from Ecological Alternative 3 in areas of the Basin upstream of Coeur d'Alene Lake. It
also includes cleanup of Spokane River sites between the Washington/Idaho border and Upriver
Dam.
3.3.5 The Selected Remedy in Relationship to a Natural Resource Damages Restoration
Plan
Comment Summary:
Some comments questioned the relationship of the Selected Remedy to actions taken by the
natural resource trustees and whether development of the Selected Remedy was motivated by a
desire to assist the natural resource trustees in their natural resource damage litigation.
EPA response:
EPA initiated the RI/FS for Operable Unit 3 because of the threats to human health and the
environment created by releases of hazardous substances, not to assist other agencies in
litigation. EPA's selection of remedies is governed by the requirements of CERCLA and the
NCP. EPA complied with these requirements in selecting a remedy in this ROD. The Selected
Remedy is not a restoration plan in support of a natural resource damages lawsuit. While the
CERCLA remedial process has certain similarities to the NRDA process in that both address the
environmental effects of mining pollution, the two processes are distinct and do not necessarily
have the same environmental objectives.
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However, EPA does have, and has met, regulatory obligations regarding coordination with
natural resource trustees. For example, NCP Section 300.430(b)(7) states that the lead agency
shall: . . . "[I]f natural resources are or may be injured by the release, ensure that state and
federal trustees of the affected natural resources have been notified in order that the trustees may
initiate appropriate actions, including those identified in Subpart G of this Part. The lead agency
shall seek to coordinate necessary assessments, evaluations, investigations, and planning with
such state and federal trustees." EPA, the lead agency here, has satisfied this coordination
responsibility during the conduct of the RI/FS and the selection of the remedy. As discussed
previously, EPA worked with a wide spectrum of entities including local governments, federal
agencies, state agencies, and Indian tribes in developing the Selected Remedy.
3.4 BACKGROUND METALS CONCENTRATIONS
3.4.1 Background Metal Concentrations Absent Mining Effects
Comment Summary:
Various comments questioned EPA's estimates of background concentrations for metals (i.e.,
metal concentrations absent mining effects) and asserted that metals concentrations in the Basin
are naturally elevated because of geologic conditions in the Basin.
EPA response:
EPA conducted extensive analyses and evaluations of background conditions as part of the
RI/FS. These analyses and evaluations conclusively demonstrated that the dominant source of
metals is from mining-related activities, not natural sources.
A comprehensive analysis of background concentrations, representing more than 10,000
samples, can be found in the RI/FS Technical Memorandum (Revision 3): "Estimation of
Background Concentrations in Soils, Sediments, and Surface Water in the Coeur d'Alene and
Spokane River Basins," USEPA 2001. Because metal concentrations are naturally variable, the
analysis quantified the range of background concentrations for each metal and selected the 90th
percentile for soils and sediments and the 95th percentile for surface water as the representative
background concentrations. The background concentrations identified for the Upper Basin
represent the most mineralized conditions and are different from background sediment
concentrations for the Lower Basin, Coeur d'Alene Lake, and Spokane River. The background
soil/sediment and surface water metal concentrations are far below, indeed are small fractions of
the existing concentrations in the mining-impacted media targeted for cleanup by the Selected
Remedy. Furthermore, the background soil and sediment lead levels are far below the
soil/sediment benchmark (530 milligrams/kilogram) reflected in the Selected Remedy. As
described in the ROD, the numerical cleanup criteria for soil and sediment may be revised as
additional information becomes available.
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3.4.2 Mining-Related Sources of Metals
Comment Summary:
Several comments questioned EPA's conclusion that the overwhelming sources of metals that
create environmental and human health risks in the Basin are from historic mining-related
practices and, in particular, that tailings-impacted sediments are the primary source of metal
loadings to Basin streams.
EPA response:
EPA's analyses and the historic record make clear that mining-related practices in general and
tailings-impacted sediment in particular are the dominant sources of metals in the Basin. The
historic record has been analyzed in USGS Open-File Report 98-595 "Production and Disposal
of Mill Tailings in the Coeur d'Alene Mining Region, Shoshone County, Idaho; Preliminary
Estimates." The USGS estimates indicate that 62 million tons of tailings containing 880,000
tons of lead and more than 720,000 tons of zinc were discharged to streams prior to 1968. As
documented in the FS, these historic releases of metal-rich tailings have mixed with Basin
sediments to create a present condition with hundreds of millions of tons of tailings-impacted,
metal-rich sediments in the floodplains (including wetlands and lakes) of the Basin and
Coeur d'Alene Lake. The 2001 USGS Open-File Report 01-140 "Lead-Rich Sediments,
Coeur d'Alene River Valley Idaho: Area, Volume, Tonnage, and Lead Content," provides
detailed estimates for lead. EPA's RI/FS Technical Memorandum (Revision 3) "Estimation of
Background Concentrations in Soils, Sediments, and Surface Water in the Coeur d'Alene and
Spokane River Basins" makes clear that metal concentrations from natural sources are small
fractions of the existing concentrations in mining-impacted soils, sediments, and surface water.
3.5 REMEDIAL INVESTIGATION/FEASIBILITY STUDY
3.5.1 Scientific Adequacy of RI/FS, Including Risk Assessments, Versus Need for
Independent Study
Comment Summary:
Some comments questioned the scientific adequacy of the RI/FS, including the risk assessments,
and called for an independent study of the Basin to determine what remedy is warranted.
EPA response:
EPA's conduct of the Basin-wide RI/FS is governed by and was consistent with CERCLA and
the NCP. The findings are based on accepted scientific and engineering principles. The RI/FS
was reviewed by a wide variety of stakeholders, including federal, state, tribal, local, and
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community entities. As described in detail in Section 3.0 of Part 2 of the ROD, EPA has
provided a wide range of opportunities for community participation in the investigation and
remedy selection processes within the Coeur d'Alene Basin. The RI/FS had a "full, scientific
review" and EPA is confident that it is scientifically defensible.
The Idaho congressional delegation has requested that the National Academy of Sciences (NAS)
review the scientific and technical analyses that form the basis of the Selected Remedy. EPA
will cooperate fully with any NAS review and will seriously consider new information or
recommendations resulting from a review. If EPA determines that substantial changes to the
ROD are appropriate based on the NAS recommendations, such changes would be subject to
additional public review and comment.
3.5.2 Adequacy of Data Collected During RI/FS to Select and Design Remedy
Comment Summary:
Some comments questioned whether sufficient data were available to select a remedy.
EPA response:
More than 10,000 samples were collected to support the RI/FS. These samples, combined with
the 7,000 additional samples collected by IDEQ, USGS, the mining companies, EPA under other
regulatory programs (e.g., the National Pollutant Discharge Elimination System), and others,
provide a solid basis to support informed risk management decisions for Coeur d'Alene Basin
mining waste contamination. EPA has made data available to the public through its website,
reports, public repositories, meetings, and specific requests.
Section 300.430 of the NCP sets out the process that EPA follows when conducting a remedial
investigation and feasibility study and selecting remedies. Section 300.430(d) provides that
"[T]he purpose of the remedial investigation (RI) is to collect data necessary to adequately
characterize the site for the purpose of developing and evaluating effective remedial
alternatives." Section 300.430(e) provides that "[T]he primary objective of the feasibility study
(FS) is to ensure that appropriate remedial alternatives are developed and evaluated such that
relevant information concerning the remedial action options can be presented to a decision-
maker and an appropriate remedy selected."
Once a remedy is selected in a ROD, the process moves into the Remedial Design phase,
followed by implementation in the Remedial Action phase. Where necessary, additional data are
collected to support design of the remedy. Data collected during the RI/FS are not intended to be
sufficient to provide all necessary data to fully design the Selected Remedy. This principle is
recognized in the NCP and in EPA guidance, and is common in implementing CERCLA
remedies nationwide. Hence, the anticipated need for additional design data to implement the
Selected Remedy is not unique to the Coeur d'Alene Basin.
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3.6 REMEDY EFFECTIVENESS AND IMPLEMENTATION ISSUES
3.6.1 Remedy Effectiveness Estimates for Surface Water Quality
Comment Summary:
Some comments questioned EPA's estimates of post-remediation metal loadings and
concentrations in Basin surface water and raised specific questions regarding the effect of
possible metal loading to surface water from precipitated zinc in aquifers or from deep
groundwater not associated with identified mining sources.
EPA response:
Quantitative estimates of post-remediation dissolved metal (zinc) loadings and concentrations in
Basin surface waters upstream of Coeur d'Alene Lake are the subject of EPA's RI/FS Technical
Memorandum "Probabilistic Analysis of Post-Remediation Metal Loading." Recognizing the
inherent uncertainty in post-remediation conditions, these estimates were based on a rigorous
probabilistic approach that quantified the uncertainty consistent with available information. In
particular, the potential loadings from precipitated zinc in deep aquifer material and from deep
groundwater not associated with identified mining sources were quantified, to the extent
practical, and conservatively assumed to be unreduced by remedial action.
The probabilistic approach was used to predict aggregate effects associated with the Preferred
Alternative upstream of the lake, as presented in EPA's RI/FS Technical Memorandum "Interim
Fishery Benchmarks for Initial Increment of Remediation in the Coeur d'Alene River Basin."
The ROD discusses how these probabilistic results were used to support the Selected Remedy.
The probabilistic analysis provides one sound technical basis to support the Selected Remedy
that is consistent with the CERCLA statute and the NCP.
To date, the probabilistic analysis has not considered the interactive effects of relevant processes
in Coeur d'Alene Lake or effects of flooding events, and so is not applicable to conditions along
the Spokane River. Enough information regarding the Spokane River does exist, however, to
develop and support the Selected Remedy.
3.6.2 Remedy Performance for Ecological Protection
Comment Summary:
Many comments expressed concern regarding the ecological protectiveness of the Selected
Remedy, including questions of long-term performance, recontamination, and the role of
potential new technology.
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EPA response:
As explained in the ROD, within its scope, the Selected Remedy protects human health and the
environment from the exposure pathway or threat it is addressing and the waste material being
managed. The effectiveness of the Selected Remedy in improving surface water quality has been
estimated to the extent practical given existing information. EPA recognizes that after the
selected remedial actions are implemented, conditions in the Upper Basin and Lower Basin may
differ substantially from EPA's current forecast of those future conditions, which is solely based
on present knowledge. Although no ARAR waivers are being invoked at this time, the
additional knowledge that will be gained by the end of this period through long-term monitoring
and five-year review processes may provide a basis for ARAR waivers in the future. In addition,
this new information and advances in science and technology may allow for additional actions to
achieve ARARs and fully protect human health and the environment in a more cost-effective
manner.
EPA also recognizes that recontamination is a major factor affecting ecological protectiveness,
particularly in the Lower Basin. The Selected Remedy was developed recognizing that a
majority of Lower Basin sediments contain lead concentrations posing a risk to ecological
receptors. One of the criteria used to select wetland areas for remediation was relatively low
potential for recontamination during flood events. Remedies implemented in the Upper Basin
and beds and banks in the Lower Basin are expected to reduce lead in sediments that may be
deposited in wetland units during future floods. Additionally, ongoing performance evaluation
of remedial efforts will provide useful data for refining remedies. EPA will review this
information during implementation of the Selected Remedy, including during five-year review
cycles, to determine the need for and the priority of remedies, not currently described in the
ROD, that may be appropriate in the future.
EPA also recognizes that development of new remedial technologies that are potentially more
cost-effective and have fewer short-term impacts than conventional technologies is an important
potential benefit of the adaptive management approach. Examples of efforts to develop new
technologies include ongoing pilot studies of chemical treatment of soil in the Lower Basin and
planned studies of passive treatment of surface water in Canyon Creek.
3.6.3 Estimated Times to Achieve AWQC and the Role of Natural Recovery
Comment Summary:
Some comments questioned EPA's estimated time period to achieve water quality standards,
with some believing this supports doing more now and some believing this supports doing much
less and relying on natural recovery.
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EPA response:
The Selected Remedy for protection of the environment in the Upper Basin and Lower Basin
will result in substantial reductions of exposures of humans and ecological receptors to metals in
the areas the remedy addresses. Full protection of human health and the environment will not be
achieved until the final remedy is implemented. The anticipated benefits of the Selected Remedy
are described in Sections 12.1.3, 12.2.3 and 12.4.3 of the ROD.
The time needed to achieve overall cleanup goals, including AWQC and risk-based sediment
cleanup goals, will be lengthy and require a period of natural recovery for all alternatives. The
probable time period decreases with the aggressiveness and completeness of the alternative.
These differences in time to achieve water quality standards are described in Section 10.2 of the
In EPA's experience at complex sites such as in the Coeur d'Alene Basin, the expectation that
considerable time will be necessary to achieve cleanup is not uncommon. For such complex
sites, EPA typically examines the magnitude and extent of contamination, selects and
implements remedies, and then collects empirical data over time to examine the efficacy of the
remedies. Once sufficient data are available, an analysis is conducted to determine if ARAR
waivers are appropriate. Although it is possible that such future data may indicate that ARAR
waivers are appropriate in the Coeur d'Alene Basin, it is not appropriate to attempt to invoke
them now.
Benefits to aquatic life begin much sooner than when AWQC are finally met. As remedies are
implemented, resulting in reduced metals concentrations, aquatic conditions begin to improve
and benefits accrue as concentrations drop further over time. Such benefits will occur much
sooner with the more aggressive alternatives (i.e., Ecological Alternatives 3 and 4). As graphed
on Figures 10.2-3 and 10.2-4 of the ROD, water quality conditions at completion of remediation
(Time 0 on the graphs), as represented by multiples of AWQC, will be considerably better under
Ecological Alternatives 3 and 4 than the other alternatives. Although the resulting conditions
will not be fully supportive of aquatic life, the reduced dissolved metals concentrations will
allow a substantial improvement to the fisheries and ecosystem, as described in more detail in
Section 12 of the ROD and the "Interim Fishery Benchmarks Technical Memorandum" (URS
200Id). The population and species diversity of fish and aquatic organisms will continue to
improve as cleanup progresses in the Basin.
Differences between the alternatives in anticipated benefits are not restricted to time to achieve
water quality standards. Section 10.2 of the ROD also describes the differences between the
alternatives in their anticipated effects on impacted sediments in the Basin, and presents a
comparative analysis which supports Ecological Alternative 3 as the best balance of tradeoffs for
a long-term cleanup approach in the Upper Basin and Lower Basin.
ROD.
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Overall, the Selected Remedy would be expected to achieve about 50 to 70 percent of the
dissolved metals load reduction in the Upper Basin (above Pinehurst) that would be anticipated
from full implementation of Ecological Alternative 3 for about 19 percent of the estimated cost
of Ecological Alternative 3.
3.6.4 Idaho TMDL for the Coeur d'Alene Basin
Comment Summary:
Some comments questioned the relationship of Idaho total maximum daily loads (TMDLs) to the
Selected Remedy.
EPA response:
The TMDL establishes waste load allocations for discrete point sources and load allocations for
non-discrete sources. It has long been recognized that non-discrete sources are the primary
sources of metals in surface water in the Basin. The CERCLA remedial process was identified
as the most effective tool for addressing these non-discrete sources. In September 1996, the
United States District Court for the Western District of Washington ordered EPA and the State of
Idaho to develop a schedule for completion of TMDLs for all water quality impaired streams
identified by the State, including the Coeur d'Alene River Basin. TMDL development was
initiated in 1998. In August 2000, a TMDL for dissolved cadmium, lead, and zinc in surface
waters of the Basin was jointly released by EPA and the State of Idaho. On September 4, 2001, a
state court judge for the State of Idaho invalidated the TMDL on the procedural grounds that the
IDEQ had not engaged in formal rulemaking when adopting the Basin TMDL. The impact of
this court decision on TMDL implementation is currently unclear, and the final status of the
TMDL has not yet been determined.
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3.6.5 Relationship of Forest Management Practices to Recontamination and Water
Quality
Comment Summary:
A number of comments noted the relationship between forest management practices on national
forest land in the North Fork Coeur d'Alene River watershed and the magnitude of flood events,
particularly those caused by rain-on-snow events. These comments stated that large flood events
result in erosion of large amounts of lead-contaminated sediment from the beds, banks, and
floodplains, particularly in the Lower Basin. The large lead loads carried by the river during
these events can result in recontamination of floodplain areas and have resulted in temporary
exceedances of the lead drinking water standard in Coeur d'Alene Lake.
EPA response:
Remedial actions for effects unrelated to releases of hazardous substances, such as deforestation
effects associated with logging practices or development, are not addressed by CERCLA unless
such effects contribute to a release of hazardous substances or potentially compromise the
effectiveness of an implemented response action.
EPA evaluated the Basin on a watershed level, therefore, the potential effects of sediment
movement associated with North Fork discharges (and other sources) were considered in
developing the RI/FS and the Selected Remedy. The available database used to develop the
Selected Remedy includes loadings in the Coeur d'Alene River, including loadings to
Coeur d'Alene Lake, during high flow events (including rain-on-snow events) that reflect large
discharges from both the North Fork and the South Fork. To increase the available database,
further field data are being collected on extreme flow events (including rain-on-snow events) by
USGS as part of ongoing monitoring for the Coeur d'Alene Basin cleanup. Additional data will
likely be collected as part of (post-ROD) remedial design. The collective data—including data
from the USGS, COE/FEMA, and USFS—will be analyzed and interpreted during remedial
design to implement the remedy selected in the ROD.
EPA anticipates that the Lake Management Plan will include measures intended to reduce
sediment loading resulting from timber harvesting. EPA will consult with state and federal
agencies on timber harvest activities in the North Fork to reduce the likelihood of adverse effects
on proposed cleanup activities.
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3.6.6 Long-Term Protectiveness and Permanence of the Remedy
Comment Summary:
A number of comments expressed a concern over the long-term protectiveness of the remedy and
a preference for more permanent solutions, such as removals. A few comments questioned the
long-term reliability of synthetic liners used in waste containment systems.
EPA response:
The long-term effectiveness and permanence of remedial actions is one of the criteria EPA
weighs when selecting remedial actions. Using permanent solutions and alternative treatment (or
resource recovery) technologies to the maximum extent practicable is a statutory requirement for
remedies selected under CERCLA. When weighing capping of contaminated materials in place
against a potentially more permanent remedy, such as disposal in an engineered repository, EPA
considers several factors, including the long-term maintenance requirements of capping, the
potential for recontamination, and cost. In some cases, the long-term maintenance requirements
of capping can be reduced by consolidating the material above the flood elevation. The decision
to cap or remove waste materials will be made during remedial design on a site-by-site basis.
The synthetic liners available today are highly effective at isolating contaminated waste, if
installed properly. The remedial design will include development of quality assurance
requirements for proper installation of liners and other remedy components.
3.6.7 Scope of Lower Basin Sediment Removal
Comment Summary:
A number of comments called for increased removal of impacted sediments in the Lower Basin.
Some of these comments cited the potential for adverse effects to waterfowl and the potential for
recontamination of downstream areas from these sediments.
EPA response:
The Selected Remedy is focused on cleaning up the highest priority upstream sources. The
remedy includes removal of up to 2.6 million cubic yards of some of the most highly
contaminated riverbed sediments. These sediments are located in the area around Dudley, where
the gradient of the main stem of the Coeur d'Alene River flattens and fine-grained sediments
containing relatively high concentrations of metals are deposited. EPA and stakeholders elected
not to include more extensive riverbed removal because of the following considerations:
• Beginning with smaller scale removals to refine cost-effective sediment removal
or management techniques
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• Confirming that removal can be conducted in a manner that is compliant with
ARARs and will not exacerbate lead movement downstream
• Uncertainty regarding repository capacity for disposal of the contaminated
sediment removed from the river beds
• Limiting the area of removal work to natural sediment deposition areas, thereby
limiting the effects of potential recontamination and the effects on boating
activities, while enhancing cost-effectiveness
• Insuring that the entire depth of contaminated sediment is excavated at the
selected location(s) to eliminate the potential for adverse impacts as a result of
exposing deeper, more contaminated sediments than those present on the surface
of the river bed
Implementation of the Selected Remedy will provide additional safe feeding area for waterfowl
and other animals through a combination of removals and capping in Lower Basin wetlands and
lateral lakes. Cleanup of some areas currently used for agriculture is also anticipated to provide
additional safe feeding area. In total, about 4,500 acres of safe waterfowl feeding areas could be
provided by the cleanup actions taken under the Selected Remedy. Implementation of the
Selected Remedy will help determine what additional actions are warranted.
3.6.8 Scope of Remedies for Water Quality and Fish Habitat
Comment Summary:
A number of comments expressed the concern that EPA could be doing more to restore water
quality and fish habitat in the watershed.
EPA response:
The Selected Remedy contains actions to reduce the concentrations of dissolved metals,
particularly zinc and cadmium, that adversely affect fish. It is estimated that the amount of
dissolved zinc entering the river system will be reduced by 580 pounds per day. This represents
26 percent of the zinc load from Basin sources outside of the Bunker Hill Box. Monitoring of
the Selected Remedy will help determine what additional actions are necessary to further reduce
zinc loadings. Additional improvements will result from remedial actions implemented within
the Bunker Hill Box.
The Selected Remedy will result in improvements to fish habitat. In areas where stream and
bank cleanups are conducted, stream and bank stabilization will also be conducted. Where
feasible, bioengineering stabilization techniques will be used. Bioengineering techniques use
natural materials such as large woody debris, native vegetation, and biodegradable materials to
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protect riverine and riparian areas from flood damage and erosion. Use of these techniques is
anticipated to result in improved fish habitat. Areas where cleanup and stabilization will occur
under the Selected Remedy include the East Fork of Ninemile Creek, Pine Creek, the South
Fork, 33 miles of banks along the lower Coeur d'Alene River, and the Spokane River, including
critical habitat areas.
3.6.9 Siting and Design of Repositories for Material Generated by Cleanup Activities
Comment Summary:
Some comments questioned how many repositories will be required as a result of this ROD.
EPA response:
EPA anticipates that the implementation of the remedy will require the construction of several
mine-waste repositories for the disposal of metals-contaminated soils, sediments, source
materials, and treatment residuals. The estimated volumes of material that may require
excavation and disposal are about 500,000 to 900,000 cubic yards in the Upper Basin and about
3,900,000 cubic yards in the Lower Basin (including up to 2,600,000 cubic yards of river bed
sediments, approximately 500,000 cubic yards of river bank and splay material, and
approximately 800,000 cubic yards of wetland and lateral lake sediment).
The number and size of repositories to accommodate the estimated volumes will be determined
during the Remedial Design Phase. It is anticipated that some of the repositories will be small
and some will be larger. Some will be used to service nearby cleanup projects (i.e., local
repositories) and some will be able to service area-wide cleanup efforts (i.e., regional
repositories). All disposal locations will be evaluated using the same process and criteria
identified in Section 12.5 of the ROD. All locations will also be subject to long-term
institutional controls and monitoring, if necessary, to ensure the integrity of the remedy.
Comment Summary:
Some comments questioned how repositories would be sited and designed.
EPA response:
EPA anticipates that a four-step process will generally be used to evaluate potential repository
locations and specify design requirements. (1) A list of potential repository sites for further
evaluation will be prepared in conjunction with local governments, property owners, and other
Basin stakeholders; (2) A technical evaluation for each specific site will be performed to assess
basic environmental and engineering issues; (3) Concurrent with the technical evaluation, a
public outreach effort will be initiated so that affected citizens are given an opportunity to
comment on the proposed repository location and design; (4) Finally, a remedial design
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document for each specific site will be prepared that summarizes design requirements, waste
acceptance criteria, and other key information associated with the short-term and long-term
management of the repository. Repositories constructed pursuant to this ROD will be designed
to reliably contain waste material and prevent the release of contaminants to surface water,
groundwater, or air in concentrations that would exceed state and/or federal standards.
3.6.10 Treatment of Surface Water from Canyon Creek
Comment Summary:
Some comments questioned the feasibility or potential effectiveness of passive treatment of
surface water from Canyon Creek, citing concerns about the availability of suitable sites with
adequate size, the feasibility of treating relatively large flows (up to 60 cubic feet per second),
the volume of treatment residuals that would be produced, the loads of metals in water that
would bypass the treatment system during high flow periods, and the potential for
recontamination of treated water after it is discharged into the South Fork Coeur d'Alene River.
Other comments sought assurances that a conventional active treatment system would be
constructed if the passive treatment system did not achieve metals removal goals. Finally, one
comment questioned whether the levels of metals in the treatment system discharge would meet
typical permit limits.
EPA response:
Each of the issues raised will be addressed during remedial design, which will include pilot
testing to evaluate the effectiveness of passive water treatment. Passive treatment would only be
implemented if the pilot testing demonstrates it will effectively remove metals from Canyon
Creek water. Responses to the individual issues raised in the comments are presented in the
following paragraphs.
Availability of suitable sites. Siting of the treatment facility or facilities will be accomplished
during the remedial design phase and will consider public input. The land area required is
anticipated to be about 5 to 10 acres. The facility or facilities would be located in areas of flat
ground in the Woodland Park area or near the South Fork in the Wallace area. The facility
would not be located immediately adjacent to the mouth of Canyon Creek.
One comment suggested the area needed would be about 4,000 acres, based on the size of a
passive wetlands treatment system. Some passive wetlands treatment systems can require long
retention periods to accomplish metals removal and hence require a relatively large area to treat a
given flow. Passive treatment with reactive media typically does not require long retention
periods, and hence a larger flow can be treated within a given footprint. Treatability testing will
further evaluate the required retention times for the various passive treatment methods.
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Feasibility of treating relatively large flows. The feasibility of treating relatively large flows (60
cfs) will be evaluated during remedial design using pilot studies. As stated in the ROD, "if
passive treatment does not prove effective, alternative treatment and control systems to achieve
the benchmark of at least a 50-percent reduction of dissolved metals loads would be evaluated.
Alternative actions may be used based on an evaluation against CERCLA remedy selection
criteria."
Volume of treatment residuals. The passive treatment would use a reactive medium, such as
apatite, that does not generate the large amounts of sludge that are associated with conventional
hydroxide precipitation-based treatment systems.
Loads of metals in water that would bypass the treatment system during high flow periods.
The expected (estimated average) value of the dissolved zinc load in Canyon Creek after remedy
implementation is estimated to be 234 pounds per day, a reduction of 322 pounds per day
compared to the expected value calculated from surface water data collected from 1991 to 1999.
The estimated load reduction is based on a design flow of 60 cfs and has taken into account the
untreated peak flows and associated loads.
Potential for recontamination of treated water. It is recognized that additional metals are added
to the South Fork as a result of surface water/groundwater interactions (i.e., river water infiltrates
into the aquifer, dissolves metals associated with the solid phase of the aquifer, and returns to the
river containing metals at higher concentrations). However, the re-dissolution of metals by
treated water is not anticipated to negate the load reductions resulting from treatment.
Geochemical modeling does not suggest that solid-phase zinc and cadmium control the
concentrations of the metals in groundwater. Hence, there is no evidence that treated water in
the South Fork that enters the groundwater system (which would be a fraction of the total treated
water) would subsequently be discharged to the South Fork at the same concentration as it would
had it not been treated.
Alternative treatment and control (including active treatment) systems. The benchmark for
Canyon Creek is to reduce dissolved metals loads discharging from the creek into the South Fork
by at least 50 percent. If passive treatment does not prove effective, alternative treatment and
control systems to achieve the benchmark of at least a 50 percent reduction of dissolved metals
loads would be evaluated. Alternative actions may be used based on an evaluation against
CERCLA remedy selection criteria. At this time, it is noted that active treatment could
potentially cost more than the $150 million estimated for source removals in Canyon Creek, and
thus active treatment is not anticipated to be cost-effective for treating large surface water flows
such as in Canyon Creek.
Levels of metals in the treatment system discharge. The expected (estimated average) value of
the dissolved zinc load in Canyon Creek after remedy implementation is discussed above. The
majority of the untreated load would not be in the treatment system discharge, but rather is
associated with two other factors. First, peak flows of Canyon Creek (e.g., flows greater than a
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design flow of 60 cubic feet per second) would not be treated, and hence daily loads would be
higher than average during peak flow periods. Second, depending on the siting of the treatment
facility, a significant load associated with groundwater may not be intercepted or treated by the
treatment system. The discharge requirements for the treated effluent are defined by the ARARs
as outlined in Section 13 of the ROD for this point-source discharge.
3.6.11 Effects of Nonmining Impacts on the Environment
Comment Summary:
Some comments suggested that non-mining impacts (e.g. urbanization, transportation corridors,
introduction of non-native fish species) have adversely affected the Basin environment and have
not been taken into account by EPA.
EPA response:
The ROD is focused on the effects of historic mining activities on the environment of the Basin.
These mining effects, which are substantial, are documented in the RI/FS (and supporting human
health and ecological risk assessment reports) and summarized in the Proposed Plan and ROD.
EPA acknowledged in its supporting technical documents that physical habitat conditions are
limiting to fish and wildlife populations, and that non-mining related modifications of habitats
for these species have had a significant effect. However, it is also apparent that secondary
effects from mining-related metals contamination have also contributed to the degradation of
physical habitat conditions in the Basin (e.g. metals can damage or eliminate vegetation, which
promotes erosion and destroys habitat). Such degradation falls under the purview of CERCLA
and was considered in the Selected Remedy.
3.7 SELECTED REMEDY FOR HUMAN HEALTH
3.7.1 Development of the Human Health Selected Remedy and EPA National Guidance
Comment Summary:
Some comments, many from the areas where residential cleanups may be conducted, questioned
the basis for the selected human health remedy and EPA's determination that human health
cleanup activities should be initiated in the Basin. These comments included questions about the
use and effectiveness of the model EPA uses to determine site-appropriate soil cleanup levels for
residential areas (the IEUBK model).
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EPA response:
The Selected Remedy for human health was developed in a manner consistent with EPA's 1994
Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities
and the 1998 clarification to the 1994 Guidance (USEPA 1994a, 1998a). These documents
describe a strategy for managing lead contamination at CERCLA sites that have multiple sources
of lead. The guidance also recommends use of the Integrated Exposure Uptake Biokinetic
(IEUBK) model and blood lead studies and ways to determine appropriate response actions at
residential lead sites.
Using the IEUBK model. The IEUBK model is the best available tool for predicting blood lead
levels in children exposed to lead in the environment. EPA's guidance also recommends the
"evaluation of blood lead data, where available," but suggests that "blood lead data not be used
alone to assess risk from lead exposure or to develop soil lead cleanup levels," recognizing that
blood lead levels below 10 |ig/dL are not "necessarily evidence that a potential for significant
lead exposure does not exist or that such potential could not occur in the future." The guidance
indicates that cleanup actions should be designed to address both current and potential future
risk, and that actions should be taken to limit exposure to soil lead levels such that a typical child
or group of similarly exposed children would have an estimated risk of no more than 5 percent of
exceeding a 10 |ig/dL blood lead level. Under a Memorandum of Agreement, the State of Idaho
took the lead in preparing the Basin Human Health Risk Assessment (HHRA) and developed the
HHRA in a manner consistent with these EPA guidance documents (USEPA 1999a).
While EPA guidance documents are not binding and do not represent final agency action,
national guidance is generally followed unless facts or circumstances related to a particular
matter indicate compliance with the guidance is inappropriate. EPA guidance documents
provide a recommended decision framework for EPA staff and consistent application of these
recommendations helps provide greater certainty to the EPA and its stakeholders, including the
regulated community. Based on the totality of circumstances, EPA believed it was appropriate to
follow national guidance in developing the Basin HHRA.
EPA and IDEQ used the IEUBK model to assist in evaluating human health risks in the Basin for
several reasons. Because EPA focuses on preventing elevated blood lead levels in children, EPA
believes it is necessary to use a tool that predicts blood lead levels in children exposed to lead in
the environment. The IEUBK model is the best tool currently available for this purpose and it
has been peer reviewed by the EPA Science Advisory Board (SAB), an independent panel of
scientific experts. The SAB concluded that the model approach is sound. EPA is not currently
aware of an alternative tool that can be used for a similar purpose, and during the course of the
RI/FS, the HHRA, and the remedy selection process (including the associated public comment
periods) no alternative was identified. In addition, exposure conditions in the Box and Basin are
similar and a substantial database on lead exposure and its subsequent effects in children is
available from many years of cleanup in the Bunker Hill Box. The amount of data related to lead
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exposure and its subsequent effect in children is unique to the Bunker Hill site. Therefore, the
Box database was used to calibrate the IEUBK Model, and the calibrated model (referred to as
the Box Model) was used in the Basin HHRA. The Bunker Hill Box database is large enough
and sufficiently representative of environmental conditions and characteristics of the exposed
population to provide a sound basis for the Box Model.
Basin Selected Remedy Compared to Box Record of Decision. The recommendations in the
1994 and 1998 EPA guidance were used to develop the Selected Remedy in this ROD, as
compared to the Selected Remedy in the 1991 residential soils ROD for the Bunker Hill Box
(USEPA 1991a). The Selected Remedy in the 1991 ROD included a community blood lead goal
of no more than 5 percent of children in each community exhibiting a blood lead level greater
than 10 |ig/dL and less than 1 percent exhibiting a blood lead of 15 |ig/dL or greater. This
approach was consistent with EPA national policy at that time (USEPA 1989b). In more recent
guidance, EPA recommends that risks be assessed at lead-contaminated residential sites using an
exposure unit defined as the individual residence and other areas where routine exposures are
occurring. Accordingly, the Selected Remedy focuses the response actions on the individual
property level to reduce lead exposure pathways, such as soil and dust, and ensure that a typical
child has no more than a 5 percent risk of exceeding a 10 |ig/dL blood lead level. This approach,
by targeting cleanup actions at the individual property level, ensures cleanup of all contaminated
residential properties in a community, thereby protecting current as well as future residents.
This difference in approach does not substantially change the soil cleanup strategy (both
remedies include partial soil removal for lead soil concentrations above 1,000 mg/kg); however,
it does affect the way that annual blood lead screening results are evaluated. While the 1991
ROD includes a community-level blood lead goal for children, the Selected Remedy in the Basin
ROD is based on reducing lead exposure pathways to reduce risks to children at the individual
property level.
3.7.2 Use of Blood Lead Observations in the HHRA and Development of the Proposed
Plan
Comment Summary:
Several comments refer to the use of blood lead screening results from the Panhandle Health
District's Lead Health Intervention Program to assess or characterize lead health hazards in the
Basin. Most of the comments refer to the nonrepresentative nature of the blood lead screenings
with respect to the overall population of the Basin, and question the appropriateness of using
blood lead observations in the site-specific analysis.
EPA response:
The HHRA takes great care to discuss the limitations of the blood lead observations in the Basin
for uses in the risk assessment, including representativeness of the results, sampling bias, and the
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potential effect of intervention on blood lead levels. Blood lead observations from the Basin
were used in the HHRA (1) to characterize age-related and geographic patterns of blood lead
concentrations among the population sampled, (2) to compare IEUBK Model predictions to
observed blood lead concentrations, and (3) in site-specific quantitative analysis to evaluate
relationships between environmental lead levels and blood lead levels. These uses do not depend
on the blood lead concentrations being statistically representative of the Basin population as a
whole.
National EPA guidance, issued in 1994 and 1998, recommends evaluation of blood lead data but
does not recommend that these data be used alone when assessing risk from lead exposure or
developing soil lead cleanup levels. The guidance recognizes that blood lead levels below 10
|ig/dL are not necessarily evidence that a potential for significant lead exposure does not exist or
that such potential could not occur in the future. The HHRA, consistent with national guidance,
evaluated the blood lead screening results in conjunction with environmental sampling data, and
follow-up investigations performed under the Lead Health and Intervention Program (LHIP) by
the Panhandle Health District (PHD).
Observed blood lead levels used in the HHRA were obtained from the PHD annual screening
program, which is conducted as a public health service to Basin residents. PHD uses the annual
screening results to provide advice and assistance to families with children exhibiting elevated
blood lead levels. These screening efforts are not intended as a research investigation.
Individuals were not randomly selected nor were they compelled to participate in a study. It has
been State policy for the last three decades to conduct blood lead screenings to identify
individual children with elevated blood levels and to provide follow-up intervention services to
identify and reduce lead exposure pathways. The Idaho Department of Health and Welfare has
not supported blood lead studies for the purpose of acquiring population-based data for academic
or experimental purposes. Instead, the State prefers to offer the voluntary program as a service
to families with young children. In the past, research studies met with resistance from local
families, which reduced participation in screening and cooperation in follow-up programs. As a
result, risk assessment and health assessment analysis is limited to the screening results of the
voluntary participants and must operate within the constraints of the overriding health response
priorities. Nevertheless, used within these limitations, these data have been useful in
characterizing lead exposure pathways and developing the Selected Remedy described in the
Information from the Bunker Hill Box also was used in the HHRA. Paired environmental and
blood lead observations collected from the Bunker Hill Box were analyzed to calibrate the
IEUBK Model. The calibrated model, referred to as the Box Model, was subsequently used in
the Basin HHRA to assess lead risks and to develop the lead soil action levels described in the
ROD. The Bunker Hill Box data spanned 11 years, included more than 4,000 pairs of blood and
environmental results, and have represented more than 50 percent of all children residing in the
Box during every year, since 1988. The Bunker Hill Box database is large enough and
ROD.
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sufficiently representative of environmental conditions and characteristics of the exposed
population to provide a sound basis for the Box Model.
Participation rates in the Basin annual blood lead screening have not been as high as those in the
Box. This may be due to a number of factors, including the absence of door-to-door solicitations
in the Basin. It is estimated that there are between 1,000 and 1,100 children from 9 months to 9
years of age in the Basin area. In 1999, the most successful year for participation, 272 children
or approximately 25 percent of eligible children participated with a $40 dollar payment ($20
each from the state and local mining companies). In other years, with payments limited to $20,
fewer than 20 percent of eligible children participated.
Different opinions have been expressed regarding potential selection bias in the annual screening
results. One argument suggests the incidence of elevated blood lead levels is biased low because
families who participated were more likely to be attentive to lead health concerns and were more
likely to have benefited from the LHIP's assistance in helping parents reduce exposures in the
home. A counter argument suggests the incidence of elevated blood lead levels is biased high
because the financial incentives for participation favored economically-disadvantaged families,
and poverty is generally associated with higher than average blood lead levels. Others requested
that the socio-economic co-factors and environmental exposures describing the sampled
population be compared to the overall population. The environmental data were compared in
Table 3.7-1 and results indicate that the environmental lead concentrations for participants in the
1996 to 1999 blood lead screenings are similar to those of the general population. There is not,
however, a complete socio-economic database for Basin children that would allow for a
comparison of risk co-factors. An additional consideration is the geographic representation of
participants in the blood lead screening program. In recent years, areas with higher lead health
risks have been under-represented in the screenings. Whether biased high or low, selection bias
relates to behavior of the participants and not the environmental conditions in which they reside.
The HHRA did not draw a conclusion relative to these different viewpoints, as there are not
sufficient data to test the competing hypotheses. These issues are discussed in Sections 6.2.2 and
7.4.1, 8.8, and 8.11.2 of the HHRA. As a result, the screening results must primarily be
interpreted as information regarding the children and families who desired screening and it may,
or may not, be representative of the majority of children who did not participate in the screening
programs. In any case, questions of the representativeness of the blood lead screening
observations to blood lead concentrations in the population as a whole are largely irrelevant since
the data demonstrates that there is a serious risk to the health of the people who exhibit elevated
blood lead levels and a clear need to address excessive lead exposure pathways.
Several individuals also questioned the use of repeat blood lead measures in the batch mode runs
for the paired data. That is, blood lead levels from the same child in successive years were
included. All available observations were utilized in the model runs presented in the HHRA, as
was used in the site-specific quantitative analysis. Similar runs also were accomplished using
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only the initial observation for each child. Both runs, with and without repeat observations, are
summarized in Tables 3.7-2a and 3.7-2b (children ages 9 to 84 months), 3.7-3a and -3b (children
ages 9 to 60 months), and 3.7-4a and -4b (children ages 9 to 24 months). The analysis showed
similar results regardless of whether the repeat observations were included.
3.7.3 The 2000-2001 Lead Health Intervention Program Blood Lead Screening Results
Comment Summary:
Several comments questioned the absence of a discussion of the 2001 annual blood lead
screening results in the Proposed Plan, noting that the data indicate a substantial reduction when
compared to the blood lead data from 1996 to 1999, which were used in the HHRA. These
individuals also state that these apparent declines in blood lead levels call into question EPA's
need to initiate human health cleanup activities in the Basin.
EPA response:
The 2001 annual Basin blood lead screening results were made available to EPA after it had
issued the Proposed Plan in October 2001. EPA has included the 2000 and 2001 blood lead
results in the ROD, and both EPA and the State of Idaho are encouraged by the improvements.
However, as noted in Sections 3.7.1 and 3.7.2, data on blood lead levels do not demonstrate that
a potential for significant lead exposure does not exist. Because of the limitations of the blood
lead data (see response to 3.7.2 above), EPA considered several environmental factors and did
not use blood lead data alone to develop the Selected Remedy for human health.
The apparent improvement in blood lead levels may be due to a number of factors
including: intervention services to families with children identified as having elevated blood
lead levels; cleanup actions at daycares, school, and homes occupied by young children; and the
reduced participation in blood lead screening by families from areas with higher environmental
lead exposures areas. There is no reason to believe that the reduction in blood lead is the result
of any natural attenuation of the risks presented by lead contamination in the environment. The
apparent success of previous efforts argues for continued intervention and cleanup efforts to
further reduce the risks of lead in the environment.
The 1996 to 1999 blood lead results indicated that about 15 percent of children 6 months to six
years of age tested had blood lead levels of 10 |ig/dL or greater and 7 percent were greater than
or equal to 15 |ig/dL. In 2000 and 2001, 13 percent and 6 percent, respectively, of children had
blood levels 10 |ig/dL or more and 4 percent and 2 percent, respectively, had levels of 15 |ig/dL
or more. Annual screening results indicate that blood lead levels differ by age and geographic
area, as shown in Tables 12.1-3 through 12.1-8 of the ROD and described in the HHRA.
The difficulties of extending the 2000-2001 results to the overall population remain the same as
with previous years (discussed in Section 7.2), with some additional complications. These
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complications include less specific information regarding environmental exposures for these
participants and significantly reduced participation by families from some geographic areas. For
example, there has been a notable decline in participation among residents of the more
contaminated residential areas east of Osburn, where mean blood lead levels remain higher than
in the remainder of the Basin. Prior to 1999, 39 children were tested in the Burke/Ninemile area
and 23 percent showed blood levels greater than 10 |ag/dL and 15 percent were greater than 15
|_ig/dL. Since 1999, parents of only 3 children from these areas have availed themselves of
testing. Another important factor that may affect blood lead screening results are the
intervention activities and cleanup actions that have been undertaken in the Basin since 1996.
Through 2001, the LHIP has provided follow-up investigations and consultation to families of 72
Basin children identified with elevated blood lead levels. As the total number of participants in
the intervention program increases, more families will benefit from home visits that provide
information to reduce exposures to lead. The continuing intervention efforts, through annual
blood lead screenings, follow-up health programs, and public and school education efforts, have
increased general community knowledge. Awareness of lead health issues also has increased
since the release of the HHRA and the RI/FS, and residents may be exercising more care in their
activities.
In addition to intervention activities, cleanup actions in Basin communities and residential areas
have been conducted since 1997. Yard soils from ninety-one homes, resident to an estimated
150 to 200 children, have been remediated as part of EPA's high-risk removal program. Seven
schools and six recreation areas have also been remediated as part of the removal program. As a
result, nearly 20 percent of all children in the Basin and, at least the 5 percent at greatest risk of
exposure, have received direct remediation and/or intervention. Twenty percent is a significant
fraction of the children at risk, considering that only about 25 percent of the Basin residential
yards are estimated to require remediation. The precise degree of exposure reductions or
decrease in lead intake rates associated with these efforts have not been quantified, but
experience in the Bunker Hill Box indicates that marked decreases in the percent of children with
elevated blood lead levels followed introduction of the aggressive intervention program,
common areas cleanup, and high-risk yard remediation programs. For example, in the first two
years of the high-risk yard cleanup in the Box (from 1989 to 1991), the incidence of children
with blood lead levels greater than 10 |ig/dL was reduced from 52 percent to 20 percent in
Kellogg and from 78 percent to 23 percent in Smelterville. However, while early intervention
and removal actions contribute to reductions in blood lead levels, remediation of all
contaminated properties is needed to ensure that children are protected from excessive exposures
both now and in the future.
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3.7.4 Lead Based Paint and the Relationship to House Dust and Blood Lead
Comment Summary:
Several comments raised concerns about the effect of interior lead-based paint on children's
blood lead levels and stated that lead-based paint, not mine waste, is the primary source of lead
in house dust.
EPA response:
The site-specific analysis in the HHRA found correlations between paint condition, paint lead
content, soil lead, and dust lead with elevated blood lead levels in children (see HHRA Section
6.4.1). The HHRA analyzed the prevalence of elevated blood lead levels among children who
were, or were not, exposed to a paint lead hazard (in the analysis, a hazard is defined as paint in
poor condition with an X-Ray Fluorescence (XRF) loading of at least 1.0 mg of lead/cm ). Of
the 524 blood lead observations in children, 58 (11 percent) had blood lead levels greater than or
equal to 10 |ig/dL and 20 of these observations were associated with an XRF paint measurement.
Analysis of these 20 observations revealed that 70 percent (14/20) of the children with elevated
blood lead levels were not associated with an interior lead paint hazard and the remaining 30
percent (6/20) of the children were associated with an interior lead paint hazard. Thus, the
majority of children with elevated blood lead levels (who resided in homes where paint was
measured) were from homes without a lead paint hazard.
It is clear that children who live in the Basin and who have elevated blood lead levels tend to be
exposed to significantly higher soil and dust lead concentrations and dust lead loading rates than
children with blood lead levels less than 10 |ig/dL. Measurements of lead loading rates have
been obtained by placing a floor mat in the home's main entrance, retrieving the mat after a
prescribed period of time, measuring how much dust and lead has accumulated, and adjusting the
lead mass to a per area per day rate (mg of lead per m of mat per day). The HHRA supports the
conclusion that both lead paint sources and soils from the yard and community contribute to
house dust lead and blood lead levels. However, lead in paint affects fewer children than lead in
soil based on available data.
These findings are consistent with the follow-up reports from PHD nurses investigating children
with elevated blood lead levels and results from other areas, including the Bunker Hill Box.
Exposures were characterized in nearly all of the children identified with elevated blood lead
levels during follow-up activities by the PHD. Potential paint exposures were noted for a few
children, and housing renovation was recommended in a small number of cases. However,
follow-up reports of children identified as having elevated blood lead levels continue to indicate
that contaminated soils and dusts are the most significant sources for the majority of children.
Some commenters have criticized the use of repeat observations for the same children in
successive years in the database used to assess the paint lead contribution. In developing the
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paint analysis protocol, EPA, IDEQ, and technical representatives to the mining companies
agreed to maximize the number of observations in the analysis. Dr. Robert Bornschein, the
consultant to the mining companies, recommended that a minimum of 150 observations be
included in the analysis. Several potential combinations of exposure and response variables were
considered. The largest available database was found to have 126 observations relating blood
lead to select environmental variables. It was agreed to use this database, which included the
repeat measurements of individuals to maximize the number of observations. Tables 3.7-5a and
3.7-5b show the analysis conducted with and without the repeat observations included. The
analysis showed similar results regardless of whether the repeat observations were included.
3.7.5 Comparison of National Declines in Blood Lead Levels and Site-Specific Conditions
Comment Summary:
Several comments suggest that the declines in children's blood lead levels in the Silver Valley
are the same as the national declines in blood lead levels and that, therefore, local declines
cannot be attributed to the aggressive cleanup of contaminated residential areas.
EPA response:
The State of Idaho compared blood lead levels collected in the Bunker Hill Box since 1974 with
the results of the National Health and Nutrition Evaluation Surveys (NHANES) for the periods
1976 to 1994 (Pirkle et al. 1994; Pirkle et al. 1998; IDHW 2000b, 2001b). Because the
NHANES studies were conducted over several years, the midpoint of each study period was used
to compare results with the Bunker Hill Box and to compute the time elapsed between
consecutive studies. Declines in blood lead levels from the Silver Valley have been substantially
greater than declines in national averages. The national reduction in overall blood lead levels
(i.e., geometric mean) was approximately 13 |ig/dL from 1976 to 1999; the Bunker Hill Box data
show a reduction of more than 30 |ig/dL during the same period of time, as seen in Table 3.7-6.
3.7.6 Soil Lead Sampling and Particle Size
Comment Summary:
Some comments questioned the sampling method used to measure lead in soil for the HHRA.
Specifically, some comments were critical of the use of soil samples sieved to 175 micrometer
(80 mesh) and recommended the use of the larger 250 micrometer sieve (60 mesh) particle size,
which has been recommended in recent EPA guidance, and other comments suggested a finer
sieve used for sediment characterization by the U.S. Geological Survey in ecological/transport
evaluations. Other comments suggested that the whole soil fraction should be used without
sieving.
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EPA response:
The 175 micrometer (fam) soil sampling technique used in the Bunker Hill Box and Basin was
adopted in 1974 during the original lead health studies and has been used for all residential soil
and dust samples collected in the Basin RI/FS. The procedure was developed to represent the
size range of particles most likely to adhere to children's hands and be ingested during normal
hand-to-mouth activities. The selection of this standard pre-dates recent recommendations from
EPA. However, subsequent research has shown that this size-range represents inadvertent soil
ingestion of particles most likely to adhere to skin (Driver et al. 1989; Kissel et al. 1996; Que
Hee et al. 1985; U.S. Environmental Protection Agency Technical Review Workgroup for Lead,
2000). While some questions remain as to the precise size fraction to use in risk assessment
protocols, the studies support an upper size-range limit between 150 and 250 [am. EPA
recommendations currently identify 250 |_im as a maximum particle size to standardize sieving
techniques, but acknowledge that site-specific differences may exist (USEPA 2000e). In the
absence of compelling evidence to support modifying the existing protocol, the State of Idaho
has decided to continue using the under 175 [am size fraction to maintain consistency in risk
characterization for the Bunker Hill Box and Coeur d'Alene Basin. EPA has concurred with the
State's approach.
Evidence from other sites suggests that larger particle size fractions are likely to exhibit lower
concentrations of lead and other metals (USEPA 1999e, 2000e). The HHRA analysis derived a
site-specific dose-response by relating observed blood lead levels to paired soil and dust lead
concentrations. This site-specific relationship was used to determine the proposed soil action
levels. Assuming that any concentration effect due to sieving is proportional, use of a larger
particle size (resulting in a lower soil or dust concentration) would have been compensated with
an increased dose-response coefficient in the Basin analysis. That is, the per unit effect of soil or
dust lead concentration on blood lead levels would have been greater. The reduced
concentration of lead would have been interpreted as a higher bioavailability of soil and dust or a
higher ingestion rate of soil and dust. EPA and the State believe that the same sieving
methodology used historically to characterize soil and dust exposure and to develop the action
levels should be used to implement the cleanup.
3.7.7 Bioavailability, Speciation, and the HHRA
Comment Summary:
Several comments refer to the chemical species of lead in Basin soils and suggest that the
relationship between blood lead and lead in soils and dusts observed in the Bunker Hill Box is
not applicable to the Basin. Some also suggest that Bunker Hill Box soil and dust contamination
is predominantly lead oxide due to the smelter, that there was limited impact of smelter
emissions "outside the Box," and that soil contamination in the Basin is lead sulfide due to mine-
related activities releasing lead as native galena ore. Because lead sulfide has low solubility,
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these comments suggest that this lead cannot be dissolved in the digestive tract and is not
absorbed by children. In addition, some commenters stated that EPA and the State of Idaho
should have conducted site-specific swine studies and speciation analyses to support the Basin
HHRA.
EPA response:
The State of Idaho and EPA have found no compelling reason to conduct swine studies and
speciation analyses for the Basin HHRA due to the vast amount of site-specific historical
emissions research and analyses relating environmental lead exposures to blood lead levels in the
Silver Valley. Extensive review and analysis of information on historic emissions from the
smelter and mining operations in the Silver Valley, including the smelter owners' own analyses,
suggest that exposures in both the Bunker Hill Box and in the Basin are likely to be a mixture of
lead oxides and lead sulfides. Analysis of airborne particulate in the 1970s indicate the ratio of
lead oxides and sulfides in Basin and Box soils are of a similar average magnitude (von Lindern
1980; von Lindern 1982). It is unlikely that all smelter-related soil and dust lead is in an oxide
form and equally unlikely that the soil and dust particles ingested by children, that originated as
mining releases, are purely a sulfide form. This conclusion is consistent with the results of the
mineralogical investigations conducted in EPA Region 8 (Casteel et al. 1996a, 1996b, 1996c,
1997a, 1997b, 1998, and 2001).
Results Summary of Swine Soil Bioavailability Studies Conducted at Other Lead Sites
The EPA Region 8 investigations concluded that samples from tailings, sulfide ore wastes, and
surface soils had relative bioavailabilities (compared to lead acetate) ranging from 1 percent (un-
weathered galena) to 90 percent for soil with iron manganese lead oxides (Casteel et al. 1996a,
1996b, 1996c, 1997a, 1997c, 1998, and 2001). The average relative bioavailability of all soils
tested (15 samples from 9 sites) was approximately 60 percent (USEPA 1999e).
The bioavailability results were reported as relative to a lead acetate control standard. Relative
bioavailabilities are computed as the ratio of soil bioavailability to lead acetate bioavailability.
Standardizing results to lead acetate facilitates comparisons of study results from different sites.
A relative bioavailability of 60 percent equates to the default bioavailability values used by the
IEUBK for soil and dust; this is equivalent to an absolute bioavailability of 30 percent (USEPA
1999e). For simplicity, bioavailability values discussed in the following paragraph refer to
absolute bioavailability (e.g. the ratio of the mass of lead absorbed divided by mass of lead
administered).
Derivation of Bioavailability at the Bunker Hill Box for the Basin Human Health Risk
Assessment
In the Bunker Hill Box, studies have evaluated concentrations of lead in soils and house dust and
subsequent effects on children's blood lead levels for more than 20 years (Landrigan et al. 1976;
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Yankel et al. 1977). The vast amount of data on children's blood lead levels in the Bunker Hill
Box has provided valuable information about how exposure to lead in the environment is
absorbed by children, as measured in their blood. This data includes more than 4,000 blood lead
measurements taken every year (since 1988) for more than a decade from the majority of
children living in the communities within the Bunker Hill Box. Each blood lead measurement
was paired with available soil and house dust lead measurements from the homes of the children
who participated in the annual blood lead screening. The availability of such a large number of
blood lead measurements, combined with a large number of environmental samples, provides a
complete picture of lead exposure and its impact on children. The amount of lead exposure data
and its subsequent effect in children is unique to the Bunker Hill site. Typically, when the site-
specific impact of lead on children is unknown, default average values for bioavailability are
used in the IEUBK Model or bioavailability is estimated by feeding soil to juvenile swine and
measuring its absorption into the blood (USEPA 1999e). Juvenile swine are believed to
represent lead absorption in children better than other species or adult animals, but there is some
uncertainty associated with using animal models for human inference (Mushak 1998; USEPA
Extensive review and analysis of historic emissions data provided substantial information about
lead speciation in the Silver Valley. Bioavailability is affected by the chemistry and physical
state of lead that is being analyzed, and by the person (or animal) exposed. For example, lead
sulfide is dissolved slowly by the digestive tract, which makes it difficult to be absorbed by the
human body. In contrast, lead oxides are more readily absorbed by the human body and are,
therefore, more bioavailable. Additionally, particles with more exposed lead at the surface are
more bioavailable than particles with lead inclusions occurring beneath the surface (Brown et al.
1999). Children absorb lead more readily than adults and people who have fasted absorb more
lead than people who have recently eaten (Maddaloni et al. 1998). Extensive analysis of dose-
response relationships between soils/dust lead content and blood lead levels were conducted in
the late 1980s, prior to the initiation of the soils cleanup in the Bunker Hill Box. These studies
suggest that both the bioavailability of lead and the contribution to blood lead levels per unit of
soil/dust lead concentration (i.e., dose-response) have been remarkably consistent throughout the
last 25 years, both before and after the smelter closure (in 1980) and during remedial activities.
No compelling evidence exists to indicate that these conclusions are not applicable to the Basin
(USEPA 1989a; USEPA 1990a).
The studies of dose-response relationships observed in the Bunker Hill Box assumed a typical
daily soil/dust ingestion rate of 100 mg and the estimated lead intake included air, diet, and
drinking water. An absorbed dose (i.e., lead uptake rate, |ag/day) was calculated that yielded the
observed blood lead levels, assuming the biokinetic parameters estimated by Kneip (Kneip et al.
1983). The parameters estimated by Kneip are used in the IEUBK Model. The result was a
coefficient relating the estimated lead intake and uptake that represents the lead bioavailability
from soil/dust. By solving for bioavailability in this way, any errors in the estimates of soil/dust
lead concentration or soil/dust ingestion rates would proportionally change the bioavailability
1999e).
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estimate because the mass of absorbed lead is the product of the lead concentration in soil/dust,
the ingestion rate of soil/dust, and bioavailability.
Therefore, if the lead concentration or ingestion rate is overestimated, then this calculation would
underestimate bioavailability proportionally.
This approach was applied to the exposure and blood lead data collected in the Bunker Hill Box
from 1974 to 1989, which yielded estimates of lead bioavailability that ranged from 14 percent to
18 percent. These estimates formed the basis for using a value of 14 percent for bioavailability
in developing the 1,000 mg/kg individual yard and 350 mg/kg community geometric mean
threshold cleanup criteria for residential soils in the Bunker Hill Box (USEPA 1991a). This
analysis was updated with an estimate of the geometric mean bioavailability (18 percent) for the
data collected from 1988 to 1998. This value was used in the Five-Year Review of the Bunker
Hill Box, and was the basis for the 18 percent value in the Box Model used in the Basin HHRA
(IDHW 2000b, 2001a). The bioavailability of soil and dust are discussed at length in the HHRA,
HHRA Response to Comments, Appendix Q to the HHRA, the 1999 Five-Year Review for the
Populated Areas of the Box, and the Extended Response to Comments for the Five-Year Review
(IDHW 2000b, 2001a, 2001b; USEPA 2000f).
Distribution of Lead Minerals Based on Historic Smelter Emissions Data
The meteorological effects on the dispersion of smelter emissions were extensively studied by
the smelter owners in their development of the supplemental control system (SCS) for the
complex. The difference between upwind and downwind impacts in the Silver Valley was small
and the impacted area extended beyond the Bunker Hill Box in both directions. In addition to
smelter emissions, other significant sources of airborne lead included transport of ore,
concentrates, and tailings and use of large-scale mechanized materials handling equipment.
Passive fugitive dust sources included windblown dust from exposed surfaces and inactive
storage piles. Geographic and terrain-related phenomena had important effects on the source
strength and the dispersion and deposition of particulate lead. Estimates of various source
impacts also were developed to assess potential compliance strategies for the smelter prior to the
time of closure. These analyses showed that different sources were dominant at different
locations. Combining the estimated relative impacts with the oxide/sulfide content of the sources
results in an estimate of the relative constituency at various locations. Airborne lead levels were
estimated to range from 57 percent to 72 percent oxides and 28 percent to 43 percent sulfides
between Cataldo and Wallace (IDHW 2001a; von Lindern 1980; and 1982). The data indicate
that the ratio of lead oxides and sulfides in historic airborne particulate matter was comparable
among the Bunker Hill Box and Basin communities.
Processes Affecting Speciation of Tailings-Derived Lead Minerals
Other contaminant migration processes were operating to mix, redistribute, and abrade lead
particulate in soils and dusts throughout the valley, including releases of mine and mill tailings.
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Prior to 1968, large masses of mine-related releases were discharged to local streams or flood
plain locations in predominantly lead sulfide form. However, oxidized ores were also likely
released because milling and extraction practices were primarily designed to capture galena from
sulfide ore. Oxidized lead minerals present in the original ores also were likely discharged to
tributaries of the Coeur d'Alene River. These waste materials were redistributed by the river,
flood events, construction activities, or mineral recovery operations. During movement and
weathering, the lead in mill tailings was subject to physical and chemical transformation through
abrasion, pH changes, and exposure to the atmosphere and aerobic hydrologic environments.
These conditions promoted decreased particle size and increased surface area, and enhanced
oxidation and the transition from lead sulfide to oxidized species. As an example of the large
quantity of lead released into the environment, between 48,000 and 90,000 tons of lead were
removed from the 300-acre Smelterville Flats area in 1998 and 1999 (IDHW 2001b).
These transformation processes are important for lead sources of greatest concern to children's
exposure. The soil and dust particles that adhere to skin are generally small, in the <150 micron
range, and more available for ingestion because of frequent hand-to-mouth activity (Driver et al.
1989; Kissel et al. 1996). That is, smaller particles adhere to hands and are more likely to be
ingested. Lead in mine tailings can occur as complexes adsorbed on particle surfaces, which are
potentially more bioavailable than the underlying lead bearing minerals which may be otherwise
poorly soluble (Brown et al. 1999). Common oxidation products of galena (lead sulfide PbS)
include cerussite (lead carbonate PbCCb), hydrocerussite (Pb3(CC>3)2(OH)2), anglesite (lead
sulfate PbSC>4), lead-bearing jarosites (iron hydroxy sulfates), and lead-bearing iron
oxyhydroxides (Roussel et al. 2000). Weathering, which increases with surface area, favors
oxidation products which can become more bioavailable over time compared to galena
(Roussel et al. 2000).
In summary, the ratio of lead oxides and sulfides in Basin and Box soils are likely similar. It is
unlikely that all smelter-related soil and dust lead is in an oxide form and equally unlikely that
the soil and dust particles ingested by children, that originated as mining releases, are purely a
sulfide form (Brown et al. 1999; von Lindern 1980; and 1982). This conclusion is consistent
with the results of micro-probe analyses studies conducted in EPA Region 8 (Casteel et al.
1996a, 1996b, 1996c, 1996d, 1997a, 1997c, 1998, and 2001). Several tailings and sulfide ore
wastes were found to be bioavailable. The results of the investigations suggest that the average
(absolute) bioavailability ranged from 1 percent to 45 percent with the average of all wastes and
soils tested being consistent with the 30 percent bioavailability default value used by EPA
(USEPA 1999e). The 18 percent used in the Basin HHRA is on the low side of bioavailability
observed across the range of potential sources and should be regarded as a minimum. The true
value could be higher if ingestion rates are less than the IEUBK default or if lead concentrations
in the 175 |am size fraction are biased high relative to the 250 [am size fraction.
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3.7.8 Subtle Health Effects of Lead Exposure
Comment Summary:
Several comments expressed the opinion that there have been no observed cases of lead
poisoning in the Basin since the Bunker Hill Smelter closed in 1981 and consequently that no
public health emergency exists in the Basin.
EPA response:
EPA and IDEQ agree that lead exposures in the Basin are not a public health emergency. The
health effect of greatest concern at blood lead levels observed in the Basin is lead's potential to
cause subtle neurologic developmental effects in children. These effects are based on systematic
observations of groups of children and would not be visibly apparent in any individual child.
Lead induced neurological effects and decreases in intelligence quotient (IQ) have been affirmed
by multiple consensus reviews undertaken by the EPA, the NAS, the Centers for Disease Control
and Prevention (CDC), and the Agency for Toxic Substances Disease Registry (CDC 1991; NAS
1993; DHHS 1999; USEPA 1986). The 1993 NAS committee report states:
The toxic effects of lead range from recently revealed subtle, subclinical
responses to overt serious intoxication. It is the array of chronic effects of low-
dose exposure that is of current public-health concern and that is the subject of
this chapter. Overt, clinical poisoning still occurs, however, and is also discussed
here. We have several reasons for emphasizing low-dose exposure. As recently
noted by (Landrigan, 1989), the subtle effects of lead are bona fide impairments,
not just inconsequential physiologic perturbations or slight decreases in reserve
capacity.
Recognition of low-dose health effects of lead and the need for primary prevention is accepted
among mainstream medical groups (see the American Academy of Pediatrics Statement
at: or the CDC Lead Prevention Fact Sheet
). Recent studies have suggested that
clinical treatment (chelation therapy), which effectively lowers blood lead levels in treated children,
is unable to prevent subtle neurological health effects (Rogan et al. 2001). Furthermore, subtle
health effects may occur at blood lead levels below 10 |ig/dL. Correlation and regression analyses
of data on blood lead levels and various health outcomes point to a spectrum of undesirable effects
that become apparent in populations having a range of blood lead levels extending upward from 10
-15 |ig/dL. These include effects on heme metabolism and erythrocyte pyrimidine nucleotide
metabolism, serum vitamin D levels, mental and physical development of infants and children, and
blood pressure in adults (Rothenberg et al. 1999; USEPA 1990a, 1990b; Wasserman et al. 1994).
Although correlations between blood lead levels and various health outcomes persist when
examined across a range of blood lead levels extending below 10 |ig/dL, the risks associated with
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blood lead levels below 10 |ig/dL are less certain (Schwartz 1994). More recent literature lends
further support to the possibility of adverse consequence of exposures that result from blood lead
levels below 10 |ig/dL (Lanphear et al. 2000). Although excessive lead exposure has been shown to
adversely affect neurological development, lead is not the only determinant of IQ. Research has
suggested that a developmentally enriched environment can combat lead-induced deficits
(Schneider et al. 2001).
3.7.9 Community Support for the Selected Human Health Remedy
Comment Summary:
Several comments suggested that there is widespread community opposition to the human health
remedy.
EPA response:
A wide range of community leaders and local citizens have participated in the various public
forums throughout the development of the Basin RI/FS and Proposed Plan and submitted comments
during the extended public comment period. While some local citizens, including some elected
officials and community leaders, have expressed their opposition to the cleanup plan for residential
areas in public forums, others have expressed their support and, in some cases, have requested a
more aggressive cleanup plan. EPA and the State of Idaho have found that many Basin
homeowners, when presented with specific information about residential cleanup, are receptive to
participating in cleanup programs.
For example, since 1997, EPA has been conducting removal actions to address lead exposures to
young children and pregnant women in the Basin. The removal program is voluntary and EPA
notified community residents about the soil and drinking water sampling that was available through
the program. From 1997 to 2001, approximately 275 Basin residents contacted EPA to have their
homes sampled for potential cleanup. Those homeowners who met the removal program criteria
were sampled, and those homes that exceeded the lead soil action level and drinking water action
levels (for homes on private wells) were remediated. From 1997 to 2001, soil at approximately 223
residential properties was tested and cleanup actions were conducted at 91 residential yards, 7
schools and daycares, and 6 recreational areas. Drinking water treatment, municipal hook-up, or
bottled water has been provided to approximately 28 residences. These yard removals represent
approximately 10 percent of the estimated total number of yards with lead concentrations greater
than 1,000 mg/kg in the Basin. In addition, the high-risk yard removals have reduced exposures to
a significant percentage of Basin children because this program was focused primarily on homes
where children or pregnant women reside.
Similarly, in the fall of 2000, IDEQ commissioned a telephone survey of residents in Kootenai and
Shoshone counties that found that 51 percent of those surveyed agreed that lead contamination in
residential yards is a serious health problem, 29 percent disagreed, and 20 percent were undecided.
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A total of 488 residents were interviewed. More recently, during the Spring of 2002, a door-to-door
survey conducted by IDEQ in the towns of Osburn and Wallace found that approximately 66
percent of the residents surveyed (176 out of 266) wanted their yards sampled to provide
information regarding potential cleanup.
3.8 ECOLOGICAL ISSUES
3.8.1 Cleanup Criteria
Comment Summary:
Some comments questioned the basis at the 530 mg/kg lead benchmark for cleanup of Lower
Basin soils/sediments.
EPA response:
There are no promulgated cleanup criteria or standards that are ARARs for the soil or sediment
of the Upper Basin or Lower Basin. Lead is the main risk driver in the soil and sediment and
accordingly, EPA has identified lead as the preferred metal to be used as a benchmark.
Background lead concentrations in the soil and sediment of the Lower Basin are estimated to be
47.3 mg/kg while the mean concentrations of lead in soil and sediment in the impacted area of
the Lower Basin are approximately 3500 to 4000 mg/kg.
To establish a benchmark cleanup criterion for sediment, EPA examined site-specific data and all
other available relevant information. For sediment in the wetlands and lateral lakes areas of the
Lower Basin, a site-specific lead level of 530 mg/kg has been identified by the United States
Fish and Wildlife Service (USFWS) as the lowest observed adverse effects level (LOAEL) for
waterfowl (Beyer, et al. 2000). The USFWS has noted that soil and sediment in 95 percent of
the floodplain habitat area of the Lower Basin have lead concentrations greater than 530 mg/kg.
Using all available lines of evidence, the EcoRA also estimated a range of sediment lead
concentrations protective of aquatic birds and mammals. The lead concentrations potentially
protective of aquatic birds and mammals include:
• 3.65 mg/kg - no observed adverse effects level (NOAEL) for protection of individuals
• 249 mg/kg - LOAEL for protection of populations
• 718 mg/kg - based on an ED2o for populations
Given the absence of promulgated criteria for metals in soil and sediment, EPA made a risk
management decision to use the site-specific protective value of 530 mg/kg lead as the
benchmark cleanup criterion for the soil and sediment in the Upper Basin and Lower Basin. This
value is based upon recent data collected in the Coeur d'Alene Basin. It is also within the range
of potentially protective values from the literature and other sites. While 530 mg/kg lead in
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soil/sediment may not be fully protective of all aquatic birds and mammals, it will address 95
percent of the habitat area. Only 5 percent of the impacted area in the Lower Basin is estimated
to have lead concentrations between 530 mg/kg and background. For these reasons, EPA
believes that selection of 530 mg/kg lead as the benchmark cleanup criterion for soil and
sediment is technically the best alternative available at this time.
It is important to recognize that numerical cleanup criteria for soil and sediment may be revised
as additional information becomes available. For example, EPA anticipates conducting studies
to evaluate soil and sediment cleanup criteria that are protective of migratory birds in riparian
and riverine habitats. As part of this effort, EPA Region 10 and USFWS are currently assessing
concentrations in soil and sediment that would be protective of riparian songbirds. Any revisions
to criteria would be documented in future decision documents.
3.8.2 Waterfowl Issues
Comment Summary:
Some comments expressed the belief that waterfowl populations in the Basin are increasing and
questioned the need to take actions to protect waterfowl.
EPA response:
Waterfowl mortality in the Lower Basin due to ingestion of contaminated soil/sediment remains
a concern, despite fluctuations in regional population size, because EPA is responsible under
CERCLA for protecting the environment and because waterfowl mortality represents
unacceptable "take" under terms of the Migratory Bird Treaty Act (MBTA). The MBTA is an
ARAR for the Basin cleanup and requires EPA to consider both individuals and populations of
waterfowl and other migratory birds.
There are many causes of mortality in animal populations, and population numbers vary from
year to year due to many factors in addition to poisoning of adult animals. The Ecological Risk
Assessment (EcoRA) and ROD (Section 7.2 of Part 2) focus on observed and expected effects of
mining-related hazardous substances on health or reproduction of waterfowl and other ecological
receptors. Waterfowl mortalities associated with the ingestion of contaminated sediments have
been reported for decades. Nearly 80 percent of all waterfowl (including many swans) found
dead or dying in the Coeur d'Alene River Basin were affected by lead poisoning due to the
ingestion of lead-contaminated soil/sediment. While it is difficult to precisely count the number
of impacted waterfowl because these birds are often scavenged by predators or hidden by
vegetative cover, there were 13 times more tundra swans found sick or dead in the
Coeur d'Alene Basin than in an adjacent reference area. Wildlife mortality information is
presented in the report by Audet et al. (1999 [cited as 1999a in the EcoRA; the report was
considered a "working draft" at the time it was referenced, but it is now available as a final
report]), and in the Report of Injury Assessment and Injury Determination: Coeur d'Alene Basin
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Natural Resource Damage Assessment, prepared for USFWS, USFS, and the Coeur d'Alene
Tribe by Stratus Consulting (2000). Species in which lead poisoning has been documented in the
Basin include mallard, wood duck, northern pintail, American wigeon, tundra swan, trumpeter
swan, Canada goose, canvasback, redhead, common goldeneye, common merganser, and
meadow vole. Chemical of concern (COC) concentrations protective for waterfowl are
presented in Section 7.2 of Part 2 of the ROD.
Waterfowl species are at greater risk than many other kinds of wildlife because they obtain much
of their food from among the contaminated sediments in the Basin, and they continue to die as a
result of their exposure, especially to lead, as summarized in Section 7.2 of Part 2 of the ROD.
The modeling done for the EcoRA estimated risks in various portions of the Basin and then
provided estimates for soil/sediment concentrations that represented NOAEL-, LOAEL-, and
ED20-based preliminary remedial goals (PRGs). These endpoints represent both individual- and
population-based protective concentrations of metals. The estimates were based on multiple
lines of evidence, including extensive field data (especially for waterfowl) and laboratory
studies. Bioavailability of lead from sediment to waterfowl was measured in the laboratory
study and was factored into the EcoRA exposure estimates.
Although remediation of contaminated areas in the Lower Basin will cause short-term disruption
of the ecosystem, the long-term benefits of reducing waterfowl and other wildlife mortality due
to lead poisoning support the decision to remediate the floodplain soil/sediment in some areas.
Among the goals of remediation are the reduction of waterfowl exposures to contaminated
sediments in the Lower Basin and the minimization of recontamination of those areas after they
are remediated. Thus, actions are proposed for both the Lower Basin and upstream source areas.
3.8.3 Fish Issues
Comment Summary:
A number of comments expressed the opinion that fish populations were increasing and
questioned the need to do additional cleanup work to protect fish.
EPA response:
While there are indications of slow recovery in some portions of the Coeur d'Alene Basin, other
areas are still severely affected and recovery is not expected to occur within many years. Fish
populations at various locations in the South Fork Coeur d'Alene River and its tributaries have
been observed over a limited period of time. This information is documented in the EcoRA and
the Technical Memorandum: Interim Fishery Benchmarks for the Initial Increment of
Remediation in the Coeur d'Alene Basin (Final) (USEPA 2001d), and it is summarized in
Section 7.2 of Part 2 of the ROD.
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During the period for which data are available, fish population abundance and composition
fluctuated due to the influence of natural and human-related influences. Nevertheless, fish
population data for the South Fork and its tributaries show a clear abundance gradient between
contaminated and uncontaminated areas. For example, fish populations on the South Fork are
much lower below the confluence with Canyon Creek, where concentrations of hazardous
substances are much higher than in the South Fork above the confluence. Similarly, fish
populations in Canyon Creek above Burke are much higher than below Burke, where metal
concentrations are higher. Exposure of aquatic organisms to metals was confirmed by the
presence of elevated concentrations of metals in the tissues of fish and invertebrates in many
portions of the Basin. Some species expected to be present (e.g., sculpin) are absent from areas
of high metals contamination. In general, areas supporting the healthiest fish populations tended
to have the highest abundance even in years when numbers on the whole were depressed.
Conversely, areas with depressed fish populations continued to support very low numbers during
years of both low and high abundance. Several available sources of invertebrate index data used
in the EcoRA indicate that macroinvertebrate diversity is depressed in areas of the
Coeur d'Alene Basin affected by mining contamination. For example, as many as 50 species of
invertebrates were observed in surveys of the non-contaminated headwaters areas, whereas only
9 or 10 metals-tolerant species were observed in downstream areas. Long-term monitoring of
aquatic populations will be required to identify trends in fish and invertebrate abundance in
response to remediation, and is proposed in association with the ROD.
3.8.4 Special-Status Species
Comment Summary:
Several comments questioned the identification of certain special-status species.
EPA response:
In accordance with the Endangered Specifies Act (ESA), special-status species have been
identified by USFWS. Risks to special status species (including federally listed endangered or
threatened species, those identified by the USFWS as species of concern, state-listed sensitive
plant species, and culturally significant plant species) were evaluated at the individual level as
well as the population level, because these species are to be more stringently protected under the
ESA or some other statute/policy guidance. Briefly, the EcoRA indicated no significant risks to
several of these species (including the bald eagle, fisher, wolverine, gray wolf, or lynx), but some
level of risk was determined to exist for several other wildlife species in at least one portion of
the Basin (as summarized in Section 7.2 of Part 2 of the ROD).
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3.8.5 Bull Trout
Comment Summary:
Several comments questioned whether bull trout are present in the Basin and suggested that it is,
therefore, inappropriate to use bull trout as a species of concern.
EPA response:
Under the ESA, the USFWS has identified bull trout as a listed threatened species and the
westslope cutthroat trout as a species of concern in the entire project area (as described in
Section 7.2 of Part 2 of the ROD). Although bull trout are rare, they have been identified in parts
of the Coeur d'Alene Basin. The affected area falls within the historic range of this species and
remains accessible to existing populations. Bull trout populations are known to exist in the St.
Joe River and Coeur d'Alene Lake, and bull trout have been observed in the North Fork
Coeur d'Alene River. These fish have access to the South Fork Coeur d'Alene River and its
tributaries, and could potentially re-colonize these habitats if limiting habitat and water
chemistry conditions are addressed. Therefore, it was appropriate to examine risks to bull trout
in the Basin from this perspective. Although the AWQC are generally protective for surface-
water biota, in areas of low hardness (e.g., 10 mg/L as CaCCb) the AWQC may not be fully
protective of individuals of special-status species such as bull trout and cutthroat trout. EPA
published an update to the AWQC for cadmium (66 FR 18935; April 12, 2001) at about the same
time as final changes were being incorporated into the EcoRA, and it was not feasible to re-
analyze risks to aquatic organisms in time to make corresponding changes in the final EcoRA.
Revised protective concentrations for cadmium are, however, shown in Section 7.2 of Part 2 and
in later sections of the ROD. In relatively soft waters of the Basin, the updated cadmium AWQC
is lower than the 1998 cadmium AWQC used in the EcoRA, and use of the 2001 criterion would
result in larger estimated cadmium risks to aquatic biota than the risks identified in the EcoRA if
the risks were recalculated.
3.9 COEUR D'ALENE LAKE
3.9.1 Relationship Between Selected Remedy and Coeur d'Alene Lake
Comment Summary:
Some comments questioned why Coeur d'Alene Lake is not included in the Selected Remedy or
mistakenly assumed it is.
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EPA response:
The selected remedy does not include remedial actions for Coeur d'Alene Lake. State, tribal,
federal, and local governments are currently in the process of implementing a Lake Management
Plan outside of the Superfund process using separate regulatory authorities.
3.9.2 Lake Management Plan
Comment Summary:
A number of comments questioned whether the Lake Management Plan will be an enforceable
and effective tool for maintaining and improving water quality in the lake. A number of
comments expressed support for implementation of the Lake Management Plan, but questioned
whether adequate funding would be available. Some viewed the lake management plan as an
unfunded institutional control.
EPA response:
EPA is looking toward implementation of the Lake Management Plan by state, tribal, and local
agencies under separate legal authorities outside of the Superfund process to reduce the
probability of additional metals movement from the sediments at the lake bottom into the lake
water. The Lake Management Plan was developed by the Coeur d'Alene Tribe, the State of
Idaho Department of Environmental Quality, and the Clean Lakes Coordinating Council, the
commissions of Kootenai, Benewah, and Shoshone Counties, Idaho, the U.S. Geological Survey,
the Coeur d'Alene Basin Restoration Project, and the Panhandle Health District to protect the
water quality of the lake.
The mechanism for funding of the Lake Management Plan is still under development. EPA will
support the efforts of state, tribal, and local agencies to obtain funding for implementation of the
plan. Funding will likely come from several sources, including the states, tribe, local agencies,
and the federal government. The Lake Management Plan, however, is not an unfunded
institutional control under Superfund because no Superfund action is being taken at this point
(see response to comment 9.1 in Table 4-1).
3.9.3 Potential for Release of Metals from Coeur d'Alene Lake Bottom Sediments
Comment Summary:
A number of comments questioned whether the chemical processes controlling metals movement
in the lake were fully understood and raised questions regarding what process(es) would lead to
increased metals mobility in lake bed sediments.
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EPA response:
The geochemistry within Coeur d'Alene Lake is complicated. The basin-wide monitoring plan
will be used as a tool to evaluate conditions in the lake and elsewhere over time.
Based on available information, the association of heavy metals (e.g., cadmium, lead, and zinc)
with metal (e.g., iron) oxides within the hypolimnion and shallow sediments is a very important
process controlling metals movement in the lake. If oxygen within the lake becomes depleted,
the metal oxides may be reduced (i.e., transformed into non-oxide forms), and the heavy metals
associated with the oxides could be released into the water column. Nutrient enrichment would
be the process most likely to cause oxygen depletion in the lake.
3.10 BUNKER HILL BOX
3.10.1 Bunker Hill Box as Source of Metal Contamination
Comment Summary:
A number of comments supported removal of dissolved metals to protect fish and identified the
Bunker Hill Box as a major source that requires cleanup.
EPA response:
The Selected Remedy contains actions to reduce the concentrations of dissolved metals,
particularly zinc and cadmium, that adversely affect fish. It is estimated the load of dissolved
zinc entering the river system will be reduced by 580 pounds per day. This represents 26 percent
of the zinc load entering Coeur d'Alene Lake from Basin sources outside of the Box.
Monitoring of the Selected Remedy will help determine what additional actions are necessary to
further reduce zinc loads. The Bunker Hill Box is a major source of dissolved metals; it
represents about half the dissolved metals load in the South Fork at its confluence with the North
Fork. Extensive remedial actions have been conducted within the Bunker Hill Box beginning in
1995 and are ongoing.
As discussed under 3.11.2 below, the Bunker Hill Box is not part of the Selected Remedy for
Operable Unit 3.
3.10.2 Relationship Between the Bunker Hill Box and the Selected Remedy
Comment Summary:
Some comments questioned whether the Bunker Hill Box would be cleaned up as part of this
ROD.
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EPA response:
Although the Bunker Hill Box is part of the Basin and, as discussed in Section 10.2 of Part 2, is a
major source of dissolved metals, the Box is not part of the Selected Remedy because it is
already the subject of ongoing remedial actions selected in existing RODs for this area. EPA is
approaching cleanup of the non-populated areas in the Bunker Hill Box in two phases. Phase 1
is focused on cleaning up known source areas. Phase 2, which is underway, includes evaluating
the efficacy of Phase 1 and determining what additional remedies, including, for example,
potential groundwater collection and treatment, are necessary. EPA will integrate actions in the
Bunker Hill Box with those described in the Selected Remedy to effectively clean up the
Coeur d'Alene Basin.
3.11 UNION PACIFIC RAILROAD
3.11.1 UPRR Cleanup in Relationship to the Selected Remedy
Comment Summary:
Some comments questioned whether the UPRR cleanup was intended to address all potential
problems within the railroad right-of-way (ROW), and, if not, what will be done to address these
problems.
EPA response:
As discussed in Section 2.3.1 of the Part 2 of the ROD, UPRR cleanup activities are continuing
as mandated by the 2000 consent decree between the United States, the Coeur d'Alene Tribe, the
State of Idaho and the Union Pacific Railroad (UPRR). This consent decree resulted from the
engineering evaluation/cost analysis (EE/CA) conducted under CERCLA removal authority.
UPRR has substantial obligations, including long-term obligations that extend in perpetuity.
Furthermore, the United States has reserved its rights against UPRR in the event that previously
unknown conditions or information arise.
The cleanup uses combinations of removal and disposal/consolidation of hazardous substances,
placing protective barriers over hazardous substances, and institutional controls. Oversight of
the UPRR cleanup is carried out by representatives of EPA, the Coeur d'Alene Tribe, and the
State of Idaho.
The UPRR cleanup was intended to protect human health. In particular, the cleanup was
intended to protect users of the recreational trail being constructed along the ROW, as well as
protect trail maintenance workers and residents in proximity to the ROW. The UPRR cleanup
was not intended to and does not cleanup all portions of the ROW. Additional actions may be
warranted in portions of the ROW, particularly in floodplain areas that are susceptible to
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recontamination. As cleanup is implemented under the UPRR consent decree, the Selected
Remedy of this ROD for the Coeur d'Alene Basin and any subsequent actions, results may
indicate additional actions may be warranted in the ROW to protect against risks to human health
and the environment. Such actions will be taken with the appropriate regulatory authority which,
depending on the circumstances, may include the UPRR consent decree, another removal action,
a remedial action, or some other action.
3.12 SPOKANE RIVER
3.12.1 Anticipated Water Quality Conditions in the Spokane River
Comment Summary:
Some comments questioned what degree of cleanup will be accomplished in the Spokane River
and why more actions are not included for the Spokane River.
EPA response:
The long-term goal is to achieve AWQC in the Spokane River. Improvements to ambient
surface-water quality will be closely tied to the pace and scope of the cleanup actions in the
Lower Basin and Upper Basin as well as the long-term retention of metals in Coeur d'Alene
Lake sediments. Although the remedial actions of the Selected Remedy will result in improved
conditions in the Spokane River, the reality is there is some uncertainty in predicting exact cause
and effect relationships for water quality improvements in the Spokane River. This argues for
the adaptive management approach to cleanup under the Selected Remedy.
3.12.2 Sole-Source Spokane Valley-Rathdrum Aquifer
Comment Summary:
A number of comments were received expressing concern about potential contamination of the
sole-source Spokane Valley-Rathdrum Prairie Aquifer (which has been designated as a sole-
source aquifer) by metals. The comments noted that this aquifer is recharged by Coeur d'Alene
Lake and parts of the upper Spokane River. Many of the comments requested monitoring of the
recharge areas and plans to mitigate potential impacts, including those that might occur from
sediment-rich floodwaters.
EPA response:
EPA recognizes the tremendous importance of the Spokane Valley-Rathdrum Prairie Aquifer to
eastern Washington. EPA is developing a long-term monitoring plan that will include
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monitoring of Coeur d'Alene Lake and the Spokane River and their potential effects on the
aquifer.
The Spokane Valley-Rathdrum Prairie Aquifer is recharged, in part, by infiltration from
Coeur d'Alene Lake and the upper Spokane River. According to a study by Wyman (1993),
about 30 percent of the recharge to the aquifer is from the lake and the river; although not
quantified, the lake contributes most of the recharge via underflow.
While Coeur d'Alene Lake and the Spokane River contain levels of some metals that are
potentially harmful to sensitive fish and aquatic organisms, the levels are well below the drinking
water standards established under the Safe Drinking Water Act for protection of human health.
Drinking \\;iKt
Kiinuc of (lissoKod imM.ils conconlriilions. iii»/l.
Mel ;il
sliindiii'd. nii/l.
Spnkiini' Ui\er
Coeur d*.Mimic l.sikc
Lead
15
0.3 to 1.2
0.2 to 4
Zinc
5,000
30 to 90
40 to 100
Cadmium
5
0.1 to 1
0.22 to 0.34
Arsenic
10
0.4 to 1.1
No data
The Lake Management Plan that will be pursued for Coeur d'Alene Lake is in part predicated on
actions that are designed to minimize remobilization of metals from the bottom of the lake into
the overlying water. Successful implementation of this plan will reduce the possibility that
metals from the bottom of the lake will adversely affect downstream areas.
A surface water/groundwater interaction study in the upper Spokane River indicated that
dissolved metals entering the aquifer from the river in this area are not migrating far beyond the
river bank or are being quickly diluted by aquifer water (Marti and Garrigues, 2001).
Concentrations of metals in the aquifer are substantially lower than the concentrations in the
water of the lake and the river.
Floodwaters can transport relatively large amounts of sediment from the Coeur d'Alene River to
the Spokane River. This sediment contains elevated levels of metals, such as lead, that bind to
sediments, and some of the sediment typically is deposited in slack water areas along the
Spokane River. Because the sediment-associated lead is relatively insoluble, it is not expected to
pose a threat of contaminating the aquifer at levels of concern. As a part of remedy monitoring,
EPA anticipates sampling depositional areas along the Spokane River after floods.
3.12.3 Cleanup Method for Sediments Behind the Upriver Dam
Comment Summary:
Comments were received from local government and utility representatives and the public
expressing concern about the possible impacts of excavating sediments that have accumulated
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-48
behind Upriver Dam. The comments postulated that existing sediments may limit infiltration of
river water at this location. Possible adverse effects of sediment excavation, and the resulting
potentially increased river water infiltration and short-term sediment mobilization, included:
• Impacts on dam integrity
• Impacts on nearby water supply wells
EPA response:
The ROD selects a combination of access controls, capping and sediment removals for this area;
however, it does not specify the exact cleanup methods that will be used. These will be
established following further study and engineering evaluation. The Washington Department of
Ecology (Ecology) also has concerns about PCBs in the sediments behind Upriver Dam. EPA
will coordinate with Ecology in the cleanup of the sediments. The engineering evaluation of
sediment cleanup will include consideration of the potential effects of cleanup actions on dam
stability and nearby water supply wells.
3.12.4 Remedies for Contaminated Sediments in Shoreline and Depositional Areas
Comment Summary:
A number of comments expressed concern about the remedies for contaminated sediments in
shoreline and depositional areas of the Spokane River and indicated a preference for maximum
removal of contaminated sediments.
EPA response:
The Selected Remedy identifies a combination of removals and capping of contaminated
sediments on Spokane River beaches and accumulated behind Upriver Dam. Each of these areas
will be the subject of a remedial design prior to implementation of the remedial action. The
details of the remedial action will be determined during remedial design. In making that
determination, a number of factors will be considered, including:
• the long-term maintenance requirements of capping
• the potential for recontamination
• cost
3.12.5 Protectiveness of Shoreline Remedies
Comment Summary:
A number of comments stated that the cleanup of the impacted shoreline areas in Washington
needs to fully protect the public health and environmental health. Many of these comments
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-49
further stated that, in case of recontamination, remedial action should be triggered by the same
criteria triggering the initial cleanup. Many of the comments also expressed that cleanup of the
Spokane River beaches should be a priority.
EPA response:
The Selected Remedy includes cleanup of beach areas upstream of Upriver Dam where lead is
present in soil or sediment at a concentration exceeding 700 mg/kg. Based on the Spokane River
screening-level risk assessment, this cleanup level, and therefore the remedy, will be protective
of public health. The Selected Remedy also will achieve protection of environmental health
through cleanup of shoreline areas that have been identified by the Washington State Department
of Ecology as critical habitat areas and include sediments that contain metals at concentrations
exceeding risk-based levels.
Cleanup of areas for protection of human health have been identified by EPA and stakeholders as
a top priority for implementation of the Selected Remedy. Should shoreline areas in Washington
become recontaminated, these areas would be addressed to ensure that human health continues to
be protected.
3.12.6 PCBs in Sediments
Comment Summary:
A number of comments identified human health and environmental concerns related to the
presence of PCBs in Spokane River sediments. Some comments suggested that risks related to
PCBs were as great as or greater than those related to metals. Some comments called for EPA to
coordinate cleanup for metals with any cleanup conducted for PCBs.
EPA response:
The RI/FS (including supporting risk assessments and technical memoranda) and Proposed Plan
addressed mining contamination in the Coeur d'Alene Basin and Spokane River. The PCB
contamination in the Spokane River sediments is not mining related and thus not part of the
Proposed Plan or ROD.
Ecology is evaluating options for cleanup of PCBs. EPA will work with Ecology as practicable
to ensure a coordinated cleanup of the Spokane River sediments that jointly addresses the PCB
and mining-related metals contamination.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-50
3.13 MONITORING
3.13.1 Monitoring as Part of the Selected Remedy for Ecological Improvement
Comment Summary:
A number of comments emphasized the importance of monitoring in the Basin and requested
clarification of the role of monitoring in the Selected Remedy. The focus of these comments
appeared to be on the ecological portions of the remedy.
EPA response:
Monitoring is a key part of the Selected Remedy for ecological improvement in the Basin. EPA,
with stakeholder input, is in the process of developing the scope and details of a long-term
monitoring program, which will be finalized after the ROD and coordinated with remedial
design. As part of this process, EPA intends to balance the wide range of viewpoints on
monitoring while meeting the legal requirements of CERCLA. Goals of the Basin-wide
monitoring are to ensure that adequate data are collected to evaluate the effectiveness of remedial
actions, progress towards the benchmarks and areas for improvement, and gain a better
understanding of Basin processes and data variability. Some of this monitoring will be
conducted routinely to examine the efficacy of the remedies over time; other portions will be
tailored to specific parts of the remedies. The monitoring will provide data for EPA to conduct
the CERCLA-required five-year reviews of the progress of remedy implementation.
3.13.2 Monitoring of Fish in Coeur d'Alene Lake and the Spokane River
Comment Summary:
A number of comments called for monitoring of fish in Coeur d'Alene Lake and the Spokane
River. Many of these comments emphasized potential risks to persons, particularly low-income
and subsistence users, that consume relatively large quantities of fish caught in these water
bodies.
EPA response:
EPA agrees that further study is needed to evaluate potential risks to persons that consume large
amounts of fish caught in the Spokane River or the Lake. EPA and the Spokane and Coeur
d'Alene Tribes are cooperating in planning additional testing and studies to evaluate these
exposures. Sampling of fish in Coeur d'Alene Lake was conducted in the spring and summer of
2002, and it is anticipated the results of testing will be available in early 2003.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-51
Table 3.7-1
Summary Statistics for Environmental Variables for Two Data Sets
(all environmental data versus the subset of environmental data paired with blood lead measurements)
Area 1 SUil
M:il 1 i-.nl i mil' Ll'i || 1 i-.nl 1 '•JHliiiL' ¦ ml* in. d.i* ¦ || Soil I c.id hiil* Ll'i || N :iriiiiin 1 c.nl ¦ mi: k«i || Inli-i Mi-.iii I'.iinl 1 i-.nl uni' rni.i || 1 \li-i km Mi-.iii I'.iinl 1 i-.hI uiii' i-iii-i
Ml llniniN | \|| < liihli i-ii || MIIIiiiiii-n | Ml( lulili i-ii || Mlllmurx | Ml < liihli i-ii || Mlllmiu-x | Ml ( liihli i-ii || Ml 1 l"iin-\ | Ml ( lulili i-ii || Mlllmurx | Ml ( liihlu-n
klM.su >\
\
IS
1 1
12
10
oo
ii
30
2S
3"
-
10
MIX
o3
Lis
O.Oo
0.1 o
22
S"
102
102
0.00
0.00
0.00
MAX
1 SS()()
3 so s
o.3 1
3"S
°22S
"S3
rsn
1 ~ so
0.S"
O.Oo
S.oO
ui:o\ii:.\\
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ooO
0." 1
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2S"
20"
loo
32o
0.02
0.02
0.03
uSI)
2.o°
2.0o
3.2o
3.32
3.3 1
2.3 s
2.0"
LSI
-.23
S.I s
1 S.oS
1 n\\ | K |S\N|\
\
1 i)
IS
1 00
IS
1 oO
38
31
1 s
10 1
23
1 02
MIX
22
ss
0.02
0.0 1
1 s
1 s
10
oS
0.00
0.00
0.00
MAX
ISOS
ISOS
2°."S
22. S2
"3^0
"3S0
31 10
31 10
".ss
0.12
0.°3
ui:omi:a\
3 X
2o3
0. IS
O.So
1 0
10 1
301
221
0.0 1
0.01
0.0 1
0.03
uSI)
3.2o
3.2 1
1. II
o. r
1.20
o.O 1
2.SI
3.so
o.2S
3.20
S.I2
Ml 1 1 W
X
r
10
10
0
los
2"
32
1 1
13
13
13
13
MIX
2"S
S02
0. 13
O.oo
10
21 s
120
SS"
0.00
0.00
0.00
MAX
1 lot)
2800
10. r
-l.'O
2021"
So20
I0o0
IOoO
().—2
0.2"
2.83
2. S3
ui:o\ii:ax
12 12
1301
I.S2
1.3 1
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030
OHS
13S s
0.03
0.03
0.10
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l."8
Lis
2.0 1
2.13
2.° 1
2.10
l.'O
2.03
o.o°
S.S8
".03
III KM
MM Mil 1
X
S 1
33
3"
2"
SS
"0
3S
33
38
38
30
38
MIX
1 "3
o0|
0.30
0.°o
32
3"
S3
S3
0.00
0.00
0.00
MAX
So |os
2 ~o01
s".r
-l\"0
^ 11 0
s 110
ssoo
SSOO
2.1 1
2.1 1
l."0
ui:omi:ax
rsi
20 1 1
I.2S
o.O"
o"o
o2S
S"o
O0o
0.02
0.0 1
o.os
uSI)
2.So
2.o0
1. 13
3.SI
3.2 ^
1.0 1
2.o3
2"2
1 0.1 s
1 I.S"
1 2.°2
nsill |<\
X
°S
3S
"3
2o2
OS
S 1
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SI
lo
-0
MIX
202
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0.1 o
0.3^
33
"o
23
82
0.00
0.00
0.00
MAX
120 |S
o020
o(i. 1 o
3.° 1
1 2SS3
I2S|
2I°2
13 10
0.3 S
0.2S
I.2S
ui:o\ii:ax
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ooo
O.SS
1,0o
11°
\32
l°3
32S
0.02
0.02
O.Oo
uSI)
1." 1
LSI
2. 1"
|o I
2. 1^
2.3 1
2.1"
2.2o
o.3S
o.S|
8.8"
MIH (.1 KINS
X
S3
1°
r
1 0
100
IS
2d
1 I
S?
28
S3
MIX
lo-
2SI
0.1 -
0.1'
2S
31
1 lo
1 o2
0.00
0.00
0.00
MAX
SS 10
2103
2 1.3"
s.~3
33^o
1200
302°
1 o lo
0.3 1
0.2 S
l.o"
ui:omi:ax
S 12
oS|
1.13
LIS
3oS
10-
oos
|03
0.02
0.03
0.0 1
0.03
uSI)
2.1 1
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2.ss
I.Oo
2.3S
2.oS
2.21
l.'S
".S3
"o"
".|0
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::
2S
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2"
-o
oo
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3"
23
3S
2 1
3 s
MIX
32o
3" 1
0.2S
0.12
o 1
o 1
"S
"S
0.00
0.00
0.00
MAX
3oSS
1 |SS
1^
2.oO
oOOS
loOO
3300
33O0
o.s-
0.28
1 .S3
ui:omi:ax
So3
8 SO
1.1 0
1.21
3S2
3 So
SS"
ooO
0.0 s
0.1 1
O.OS
uSI)
1.03
I.SS
2. 12
2.2 s
2.2 1
2.S2
2.23
o.So
3."o
S.2 1
U \l 1 \( 1
X
12
12
33
0
1 0
So
3S
|o
3"
2o
3"
MIX
oO 1
~ 1 o
0.3 S
i.r
S 1
oS
2 so
oSI
0.00
0.01
0.01
MAX
l~o2 1
3 II0
1 SS.2"
l.'S
1 o02_
3020
20"2 1
3300
1.23
1.20
°.on
3.10
ui:omi:ax
1" 1
2.o3
2.31
1
100 1
o.os
0.22
uSI)
2.S 1
3.1 1
1 ,o0
2. r
2.33
S.2o
".So
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-52
Table 3.7-2a
IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-84 Months: Default and 40:30:30 - with repeat observations
Miilhui
liiirkc Nun- Mill-
U iilhu'i'
S||\ 1-rlnli
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
()bsen ed
(] )elault)
(40:30:30)
()bseived
(Default)
(40:30:30)
()bseived
(J )elault)
(40:30:30)
()bseived
(Default)
(40:30:30)
N
15
15
15
46
46
46
39
39
39
55
55
55
Minimum (ug/dl)
2
5
4
1
4
3
1
6
4
2
2
2
Maximum (ug/dl)
12
16
9
21
27
17
19
21
13
23
19
11
Arithmetic Mean (ug/dl)
5.5
10.2
6.4
7.8
10.2
6.6
6.1
10.0
6.5
5.5
7.3
4.7
Geometric Mean (ug/dl)
4.7
9.7
6.1
6.3
9.2
6.1
5.2
9.6
6.3
4.6
6.7
4.5
Geometric Standard Deviation
1.75
2.08
1.73
1.98
1.76
1.78
1.82
1.64
1.70
1.81
1.86
1.79
%> 10 ug/dl
13%
48%
19%
22%
44%
20%
13%
47%
19%
11%
26%
8%
%> 15 ug/dl
0%
22%
5%
15%
22%
7%
5%
20%
5%
5%
10%
2%
IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-84 Months: Default and 40:30:30 (continued)
< Khiini
Side < iiiklu-s
kllll>sln||
l.nUlT lisiMII
1 nl;il
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
()bserved
(] )elault)
(40:30:30)
(>bserved
(Default)
(40:30:30)
Obseived
(I )efault)
(40:30:30)
()bserved
(Default)
(40:30:30)
(Jbseived
(Default)
(40:30:30)
N
62
62
62
30
30
30
36
36
36
28
28
28
311
311
311
Minimum (ug/dl)
1
3
2
1
2
2
1
2
2
1
2
2
1
2
2
Maximum (ug/dl)
11
14
8
9
14
8
16
9
5
18
28
16
23
28
17
Arithmetic Mean (ug/dl)
4.6
6.2
4.2
4.0
6.1
4.2
5.7
5.0
3.4
6.9
7.0
4.5
5.7
7.6
5.0
Geometric Mean (ug/dl)
4.0
5.7
4.0
3.6
5.7
4.0
4.3
4.7
3.3
4.9
4.5
3.2
4.6
6.6
4.5
Geometric Standard Deviation
1.77
1.86
1.74
1.64
1.79
1.73
2.17
1.83
1.72
2.40
2.68
2.81
1.93
2.02
1.90
%> 10 ug/dl
5%
19%
5%
0%
17%
5%
17%
11%
2%
32%
21%
14%
13%
28%
11%
%> 15 ug/dl
0%
6%
1%
0%
5%
1%
17%
2%
0%
11%
16%
7%
7%
12%
3%
Note: observed levels are for children 9-84 months or 0-7 years old as opposed to community mode showing observed levels for 0-9 year olds.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-53
Table 3.7-2b
IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-84 Months: Default and 40:30:30 - without repeat observations
NO REPEATS
Miilhui
liiirkc Nun- Mill-
U iilhu'i'
S||\ i-l'lbserved
(Default)
(40:30:30)
(ibscived
(] )efault)
(40:30:30)
Observed
(Default)
(40:30:30)
N
15
15
15
j:
37
j:
35
35
35
Ju
36
Ju
Minimum (ug/dl)
2
5
4
1
4
3
1
6
4
2
3
2
Maximum (ug/dl)
12
16
9
20
27
17
19
21
13
23
17
10
Arithmetic Mean (ug/dl)
5.5
10.2
6.4
7.4
10.5
6.7
6.1
10.2
6.6
6.1
7.4
4.8
Geometric Mean (ug/dl)
4.7
9.7
6.1
6.1
9.5
6.2
5.1
9.8
6.4
5.1
6.8
4.6
Geometric Standard Deviation
1.75
2.08
1.73
1.90
1.72
1.80
1.85
1.60
1.70
1.81
1.87
1.77
%> 10 ug/dl
13%
48%
19%
19%
46%
21%
14%
48%
20%
14%
27%
8%
%> 15 ug/dl
0%
22%
5%
11%
24%
8%
6%
22%
6%
8%
10%
2%
IEUBK Batch Mode Overall Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-84 Months: Default and 40:30:30 (continued)
< Khiini
Side < iiiklu-s
kllll>sln||
l.nUlT lisiMII
Inl;il
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
()bseived
(J )elault)
(40:30:30)
()bseived
(Default)
(40:30:30)
()bseived
(I )elault)
(40:30:30)
()bseived
(Default)
(40:30:30)
()bseived
(Default)
(40:30:30)
N
52
52
52
23
23
23
32
32
32
26
26
26
256
256
256
Minimum (ug/dl)
1
3
2
1
2
2
1
2
2
1
2
2
1
2
2
Maximum (ug/dl)
11
14
8
9
14
8
16
9
5
18
28
16
23
28
17
Arithmetic Mean (ug/dl)
4.7
6.4
4.3
4.2
6.2
4.3
5.9
4.9
3.4
6.6
6.0
3.9
5.8
7.6
5.0
Geometric Mean (ug/dl)
4.1
5.9
4.1
3.7
5.8
4.1
4.4
4.6
3.3
4.7
3.98
2.9
4.7
6.6
4.5
Geometric Standard Deviation
1.75
1.88
1.75
1.75
1.81
1.73
2.24
1.83
1.71
2.42
2.45
2.62
1.94
2.06
1.91
%> 10 ug/dl
6%
20%
5%
0%
18%
5%
19%
10%
2%
31%
15%
10%
14%
28%
11%
%> 15 ug/dl
0%
7%
1%
0%
5%
1%
13%
2%
0%
12%
12%
6%
6%
12%
3%
Note: observed levels are for children 9-84 months or 0-7 years old as opposed to community mode showing observed levels for 0-9 year olds.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-54
Table 3.7-3a
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-60 Months: Default and 40:30:30 - with repeat observations
Mnlhin
linrkc Nun- Mill-
U iilhicc
Sil\ i-r l < hi
(>bservcd
Predicted
(Default)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
()bserved
Predicted
(Delimit)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
N
8
8
8
31
31
31
26
26
26
46
46
46
Minimum (ng/dl)
2
8
5
2
4
4
2
7
5
2
3
2
Maximum (jxg/dl)
12
13
8
21
27
17
19
21
13
23
19
11
Arithmetic Mean (ng/dl)
6.8
10.9
6.9
7.9
11.1
7.2
7.0
10.9
7.2
6.0
7.8
5.0
Geometric Mean (jxg/dl)
5.8
10.7
6.8
6.3
10.0
6.7
6.0
10.6
7.1
5.0
7.2
4.8
Geometric Standard Deviation
1.87
1.64
1.65
1.98
0.98
1.77
1.79
1.79
1.66
1.78
1.81
1.75
%> 10 jig/dl
25%
56%
22%
23%
48%
24%
19%
54%
25%
13%
29%
10%
%> 15 fig/dl
0%
25%
6%
16%
26%
9%
8%
25%
7%
7%
12%
2%
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-60 Months: Default and 40:30:30 (continued)
< Khiini
Sldr < iiiklu-s
klll^slnli
l.nuiT lisiMII
1 nl;il
()bserved
Predicted
(Delimit)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
(>bser\ ed
Predicted
(Default)
Predicted
(40:30:30)
()bser\ ed
Predicted
(Default)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
N
43
43
43
23
23
23
27
27
27
18
18
18
m
in
% % %
Minimum (ug/dl)
1
3
3
1
3
2
1
3
2
1
2
2
1
2
2
Maximum (ug/dl)
11
14
8
9
14
8
16
9
5
18
28
16
23
28
17
Arithmetic Mean (ng/dl)
5.0
6.5
4.4
4.2
6.6
4.5
6.7
5.6
3.8
8.2
9.3
5.7
6.3
8.2
5.4
Geometric Mean (ug/dl)
4.3
6.1
4.3
3.8
6.3
4.4
5.4
5.3
3.7
6.2
5.7
4.1
5.1
7.2
4.9
Geometric Standard Deviation
1.80
1.83
1.71
1.61
1.75
1.69
2.03
1.79
1.68
2.31
3.27
3.11
1.90
1.96
1.86
%> 10 fig/dl
7%
20%
6%
0%
20%
6%
22%
14%
3%
39%
32%
21%
16%
31%
13%
%> 15 fig/dl
0%
7%
1%
0%
6%
1%
15%
3%
0%
17%
25%
11%
8%
14%
4%
Note: observed levels are for children 9-60 months or 0-5 years old.
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RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-55
Table 3.7-3b
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-60 Months: Default and 40:30:30 - without repeat observations
XO RFPF\TS
Miilhui
liiirkc Niiii- Mill-
U iilhicc
Sil\ i-r l < hi
(>bservcd
Predicted
(Default)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
()bserved
Predicted
(Delimit)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
N
8
8
8
24
24
24
23
23
23
31
31
31
Minimum (ng/dl)
2
8
5
2
4
4
2
8
6
2
3
2
Maximum (jxg/dl)
12
13
8
20
27
17
19
21
13
23
17
10
Arithmetic Mean (ng/dl)
6.8
10.9
6.9
7.1
11.6
7.5
7.0
11.2
7.4
6.5
7.9
5.1
Geometric Mean (jxg/dl)
5.8
10.7
6.8
6.0
10.4
6.9
5.9
10.9
7.3
5.4
7.4
4.9
Geometric Standard Deviation
1.87
1.64
1.65
1.81
1.88
1.79
1.83
1.75
1.65
1.80
1.82
1.73
%> 10 jig/dl
25%
56%
22%
17%
51%
26%
22%
56%
26%
16%
31%
10%
%> 15 fig/dl
0%
25%
6%
8%
28%
11%
9%
27%
8%
10%
12%
2%
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-60 Months: Default and 40:30:30 (continued)
< Khiini
Sldr < iilli'lii'N
klll^slnli
I.IIMIT IfclMII
1 nl;il
()bserved
Predicted
(Delimit)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
(>bser\ ed
Predicted
(Default)
Predicted
(40:30:30)
()bser\ ed
Predicted
(Default)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
N
38
38
38
19
19
19
25
25
25
16
16
16
184
184
184
Minimum (ug/dl)
1
3
3
1
3
2
1
3
2
1
2
2
1
2
2
Maximum (ug/dl)
11
14
8
9
14
8
16
9
5
18
28
16
23
28
17
Arithmetic Mean (ng/dl)
5.1
6.7
4.5
4.4
6.6
4.6
6.9
5.4
3.7
7.9
7.9
5.0
6.3
8.2
5.4
Geometric Mean (ug/dl)
4.4
6.2
4.4
3.9
6.3
4.4
5.5
5.1
3.6
5.8
4.9
3.6
5.2
7.2
4.9
Geometric Standard Deviation
1.74
1.85
1.72
1.68
1.77
1.70
2.07
1.78
1.68
2.38
2.79
2.88
1.88
2.01
1.88
%> 10 fig/dl
8%
22%
6%
0%
21%
6%
24%
12%
2%
38%
24%
17%
17%
32%
13%
%> 15 fig/dl
0%
7%
1%
0%
6%
1%
16%
3%
0%
19%
19%
9%
8%
14%
4%
Note: observed levels are for children 9-60 months or 0-5 years old.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-56
Table 3.7-4a
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-24 Months: Default and 40:30:30 - with repeat observations
Mulhin
liiirki' Niiii- Mill-
U iilhu'i'
S||\ i-l'l 10 jLlo/dl
25%
65%
30%
30%
67%
42%
38%
59%
29%
19%
35%
13%
%> 15 jLig/dl
0%
33%
8%
30%
44%
20%
13%
28%
8%
19%
15%
3%
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-24 Months: Default and 40:30:30 (continued)
< Khiini
Side < iiiklu-s
kllll>sln||
l.nUlT lisiMII
1 nl;il
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
Predicted
(observed
(Default)
(40:30:30)
C )bserved
(Default)
(40:30:30)
(>bserved
(Delimit)
(40:30:30)
(observed
(Delimit)
(40:30:30)
C)bserved
(Delimit)
(40:30:30)
N
14
14
14
9
9
9
7
7
7
7
7
7
75
75
75
Minimum (ug/dl)
2
3
3
2
5
4
2
3
2
3
2
2
2
2
2
Maximum (jig/dl)
11
12
8
9
14
8
15
9
5
18
25
15
23
27
17
Arithmetic Mean (ng/dl)
6.5
6.2
4.5
5.2
7.4
5.0
7.7
6.5
4.3
8.7
8.9
5.6
7.5
9.2
6.1
Geometric Mean (jig/dl)
6.0
5.7
4.3
4.8
7.0
4.9
6.3
6.1
4.2
7.1
5.5
4.0
6.2
7.9
5.5
Geometric Standard Deviation
1.55
1.87
1.73
1.55
1.72
1.69
2.03
1.82
1.67
2.04
2.88
3.07
1.82
2.08
1.91
%> 10 fig/dl
14%
18%
6%
0%
26%
9%
29%
20%
4%
43%
29%
21%
23%
37%
17%
%> 15 jig/dl
0%
6%
1%
0%
9%
2%
14%
5%
1%
14%
23%
12%
12%
19%
6%
Note: observed levels are for children 9-24 months or 0-2 years old.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-57
Table 3.7-4b
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-24 Months: Default and 40:30:30 - without repeat observations
NO REPEATS
Mnlhin
liiirki' Niiii- Mill-
U iilhu'i'
S||\ i-l'lbserved
Predicted
(Delimit)
Predicted
(40:30:30)
(observed
Predicted
(Default)
Predicted
(40:30:30)
\
4
4
4
9
9
9
8
8
8
15
15
15
Minimum (ug/dl)
5
10
7
2
8
6
3
8
6
3
4
3
Maximum (jig/dl)
11
13
8
20
27
17
16
15
9
23
17
10
Arithmetic Mean (ng/dl)
7.8
12.1
7.8
8.0
14.9
9.6
8.1
11.4
7.7
7.8
8.7
5.6
Geometric Mean (jig/dl)
7.4
12.1
7.8
5.9
13.4
8.9
7.0
11.2
7.6
6.4
8.1
5.4
Geometric Standard Deviation
1.44
1.61
1.61
2.31
2.09
1.70
1.83
1.64
1.64
1.84
1.88
1.75
%> 10 jLlo/dl
25%
65%
30%
22%
66%
41%
38%
59%
29%
20%
37%
13%
%> 15 jLig/dl
0%
33%
8%
22%
42%
20%
13%
28%
8%
20%
16%
3%
IEUBK Batch Mode Observed vs. Predicted Blood Lead by Geographic Area, Ages 9-24 Months: Default and 40:30:30 (continued)
< Khiini
Side < iiiklu-s
kllll>sln||
I.II\\(T IfclMII
1 nl;il
()bserved
Predicted
(Delimit)
Predicted
(40:30:30)
C)bserved
Predicted
(Delimit)
Predicted
(40:30:30)
()bserved
Predicted
(Delimit)
Predicted
(40:30:30)
()bserved
Predicted
(Default)
Predicted
(40:30:30)
C )bserved
Predicted
(Default)
Predicted
(40:30:30)
N
13
13
13
9
9
9
7
7
7
7
7
7
72
72
72
Minimum (ng/dl)
2
3
3
2
5
4
2
3
2
3
2
2
2
2
2
Maximum (jig/dl)
11
12
8
9
14
8
15
9
5
18
25
15
23
27
17
Arithmetic Mean (ng/dl)
6.5
6.3
4.5
5.2
7.4
5.0
7.7
6.5
4.3
8.7
8.9
5.6
7.4
9.2
6.1
Geometric Mean (jig/dl)
5.9
5.8
4.4
4.8
7.0
4.9
6.3
6.1
4.2
7.1
5.5
4.0
6.2
7.9
5.5
Geometric Standard Deviation
1.57
1.88
1.73
1.55
1.72
1.69
2.03
1.82
1.67
2.04
2.88
3.07
1.81
2.08
1.90
%> 10 fig/dl
15%
19%
7%
0%
26%
9%
29%
20%
4%
43%
29%
21%
22%
38%
17%
%> 15 jLig/dl
0%
7%
1%
0%
9%
2%
14%
5%
1%
14%
23%
12%
11%
19%
6%
Note: observed levels are for children 9-24 months or 0-2 years old.
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-58
Table 3.7-5a
General Linear Model and Regression Coefficients for Blood
Lead and Environmental Sources - with repeat observations
Dependent Variable: BLPB
R-Square=0.597 (P<0.0001)
N=126
Yariahle
llslimale
l»i>l
Standardized IMimale
Intercept
2.8644
0.0032
0.0000
AGE
-0.3351
0.0007
-0.2056
SOILPB
0.0007
0.0012
0.2249
LEADLD
0.1638
0.0006
0.3212
EXTMED
0.5176
0.0005
0.2742
INTCCMIN
1.9230
0.0008
0.2313
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-59
Table 3.7-5b
General Linear Model and Regression Coefficients for Blood Lead and Environmental
Sources - without repeat observations
Dependent Variable: BLPB
R-Square=0.598 (P<0.0001)
N=97
\ ariahle
r.slimale
Pr>F
Siaiulardi/ed l-lslimale
Intercept
3.0020
0.0072
0.0000
AGE
-0.3261
0.0056
-0.1907
SOILPB
0.0005
0.0435
0.1635
LEADLD
0.1895
0.0006
0.3803
EXTMED
0.4572
0.0083
0.2365
INTCCMIN
2.0071
0.0023
0.2401
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 3.0
Page 3-60
Table 3.7-6
Blood Lead Declines in National Surveys, Smelterville, and Kellogg
Annuali/ed Decline using
niid-poinis of slud\ periods
Time Period
Ccomclric mean ug/dl.
Ug/dl. per >ear
National Blood Lead Levels
1976-80
15.0
--
1988-91
3.6
1.0 (Annestetal. 1983)
1991-94
2.7
0.3 (Brodyetal. 1994)
1999
2.0
0.1 (Pirkleetal. 1998)
1978-99
0.6 (CDC 2000)
Smelterville Blood Lead Levels
1975
44.8
--
1989-90 midpoint
11
2.3 (IDHW 2000b)
1992-93 midpoint
6.6
1.5 (IDHW 2000b)
1999
3.6
0.5 (IDHW 2000b)
1975-99
1.7 (IDHW 2000b)
Kellogg Blood Lead Levels
1975
37.4
--
1989-90 midpoint
8.8
2.0 (IDHW 2000b)
1992-93 midpoint
6.1
0.9 (IDHW 2000b)
1999
3.7
0.4 (IDHW 2000b)
1975-99
1.4 (IDHW 2000b)
-------
RECORD OF DECISION
Bunker Hill Mining and Metallurgical Complex OU 3
September 2002
Part 3, Responsiveness Summary
Section 4.0
Page 4-1
4.0 RESPONSES TO INDIVIDUAL COMMENTS
In Section 4.0 of the Responsiveness Summary, EPA's responses to individual comments are
presented. The comments and responses are organized alphabetically by the last name of the
person providing the comment in Table 4-1. Each comment was assigned a unique comment
number. Many commenters submitted more than one comment, and an individual comment
number was assigned to each of these comments.
Many comments addressed similar issues. In this case, the response for a given issue is provided
once, and additional comments addressing the same issue are referenced to the comment number
where this response is provided. These referenced responses are organized in numerical order by
comment number in Table 4-2. When using Table 4-2, the user should be aware that in some
cases the reference responses may address more issues than those raised in the user's comment.
In these cases, it is expected that the user will be able to identify those parts of the referenced
response applicable to his or her comment. In other cases, a comment may raise multiple issues.
In such a case, a user may be referred to multiple reference responses for a complete response to
all issues raised. An overview of issues raised and EPA's responses is provided in Section 3.0.
A small number of written comments were illegible and some oral comments were inaudible.
EPA has included these comments in this section and has attempted to respond to such
comments where possible. As provided in the CERCLA statute, Section 117(b), EPA is only
responsible for providing responses to each of the "significant" comments, criticisms, and new
data. Comments not meeting this statutory criterion have nonetheless been recorded in this
section.
Following Table 4-2 is a list of references used in the responses to comments related to the
human health remedy.
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