United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R10-92/041
September 1992
vc/EPA Superfund
Record of Decision:
Bunker Hill Mining & Metallurgical
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NOTICE
The appendices listed in 1M index that are not found in this document have been removed at 1M request of
the issuing agency. They contain material which supplement. but adds no fur1her appIIc:abIe information"to
the content of the document. All supplementai material is, hoWever. con1Bin8d In the administrative record
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50272.101
REPORT DOCUMENTATION II. REPORTNO. I ~ 3. Aoc/fIIenI'. A~on No.
PAGE EPA/ROD/R10-92/041
4. TIlle.nd Sublllle 5. Report DIlle
SUPERFUND RECORD OF DECISION 09/22/92
Bunker Hill Mining and Metallurgical Complex, ID
6.
Second Remedial Action - Final
7. Aulhor{.) 8. Perfonnfng Org.niz8lion RepI. NO'
9. Perfo",ling Org8lniz8lion N8me end Add..... 10. ProjecllTuklWork Unil No.
11. ConIncl(C) or Gnanl(G) No.
(C)
(G)
12. Sponeonng Org.niZ8lion N8me - -- 13. Type of Reporl & Period CoV8r8d
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. SUpplemenlary Note.
PB93-964611
16. Abstr.ct (Umll: 200 word.)
The Bunker Hill Mining and Metallurgical Complex site, a 21-square-mile area centered
around an inactive industrial mining and smelting site, includes the Cities of Kellogg,
Page, Pinehurst, Smelterville, Wardner, Shoshone County, Idaho. The inactive several
hundred acre industrial complex includes the Bunker Hill mine and mill, a lead and zinc
smelter, and a phosphoric acid fertilizer plant. Other site features include the South
Fork of the Coeur d'Alene Rive r; an alluvial floodplain bordered by mountains, valleys,
and gulches; and vegetated residential areas. In 1886, the first mill for processing
lead and silver ore was constructed at the site. In later years, operations were
expanded with the addition of a lead smelter; a blast furnace; and electrolytic zinc,
sulfuric acid, phosphoric acid, and fertilizer plants. Onsite operations and disposal
practices have caused the deposition of metals to offsite areas throughout the valley
via airborne particulate deposition; alluvial deposition of tailings dumped in the
river; and migration from onsite sources. Initially, most solid and liquid residue
from the complex was discharged into the river. When the river flooded, these
materials were deposited onto the valley floor and were leached into onsite soil and
ground water. Although some industrial wastes were removed and disposed of offsite,
(See Attached Page)
17. DGCUnI8nl An8Jyei. L OncripIG..
Record of Decision - Bunker Hill Mining and Metallurgical Complex, ID
Second Remedial Action - Final
Contaminated Media: soil, sediment, debris, gw, sw
Key Contaminants: organics (PCBs) I metals (arsenic, lead), inorganics (asbestos)
b. IdenlifienlOpenoEncled TerT118
c. COSA T1 FleklfGroup
18. Ann.b/Wly SI8Iemenl 19. Secuity aa.. (This Report) 21. No. 01 P8ge8
None 168
20. Secuity a... (Th18 Page) ~ PrIce
None
See ANSl-Z39.18 272 (4-77)
SH IMtruC~OM on Re-
(Formerly NnS-3S)
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EPA/ROD/R10-92/041
Bunker Hill Mining and Metallurgical Complex, ID
Second Remedial Action - Final
Abstract (Continued)
thousands of tons of sludge, tailings, flue dust, and other wastes still remain onsite.
In 1973, a baghouse fire severely reduced air pollution control capacity at the lead
smelter. A 1974 public health study and concurrent epidemiologic and environmental
investigations concluded that atmospheric emissions of particulate lead from the active
smelter were the primary sources of elevated blood lead levels in local children. In
1977, two tall stacks were added to disperse contaminants from the complex. Smelter
operations ceased in 1981, but limited mining and milling operations continued onsite
from 1988 to 1991. In 1989, EPA began a removal program to excavate lead-contaminated
soil from affected residential properties. Several additional removal actions for source
materials were also completed by various PRPs from 1989 to 1991. The site has been
divided into several sections for remediation based on population levels: the Hillside
Area; Smelterville Flats; Central Impoundment Area (CIA), Page Pond, Smelter Complex;
mine operations area, right-of-way within nonpopulated areas, and future development
areas. A 1991 ROD addressed contaminated residential soil within the populated areas of
the site, as OU1; provided for the excavation of soil with lead contamination above 1,000
mg/kg at 1,800 residential properties with disposal at an onsite repository, which was
subsequently capped; and provided clean soil and sod to residents. This ROD addresses a
final remedy for OU2, the nonpopulated areas of the site and those aspects of the
populated areas not addressed by the 1991 ROD. The primary contaminants of concern
affecting the soil, sediment, debris, ground water, and surface water are organics,
including PCBs; metals, including arsenic and lead; and inorganics, including asbestos.
The selected remedial action for this site includes revegetating the Hillside Area with
less than 50 percent cover; contour terracing eroded hillsides and installing
erosion-control structures; re-establishing riparian habitat and mitigating eroding
tailings in Smelterville Flats; consolidating jig tailings into CIA; establishing soil
barriers in contaminated areas; relocating the A-I gypsum pond sediment to CIA; capping
the A-4 gypsum pond or consolidating it within CIA; removing materials from the 1982
smelter cleanup and consolidating these within the smelter closure; relocating the slag
pile to either the CIA or Smelter Complex; removing tailings from the West Page Swamp and
consolidating these in Page Pond and capping the pond with residential soil; improving
the channels for Humboldt and Grouse creeks; reprocessing, recycling, or treating all
principal threat materials, including copper flue dust using cement-based stabilization;
=emoving and recycling salvageable items; demolishing and decontaminating onsite
structures; capping the CIA, Lead Smelter, and Zinc Plant with low permeability caps;
collecting and treating the CIA, Lead Smelter, and Zinc Plant leachate; treating,acid
~ine drainage from the Bunker Hill mine in the Central Treatment Plant prior to discharge
to the wetlands treatment system; closing the onsite solid waste landfills; continuing
blood level monitoring for lead and high-efficiency vacuum loan program to site
residents; cleaning all homes exceeding 1,000 ppm lead house dust after remedial actions
are completed, and developing and implementing an interior dust monitoring program;
recovering and treating the ground water in Government Gulch; constructing a passive
wetland treatment system in Smelterville Flats and Pinehurst narrows to treat CIA seeps,
pretreated acid mine drainage, and ground water and surface water from Government Gulch,
as well as leachate from the lead and zinc closure areas, using absorption and
precipitation of metals within an anaerobic substrate; constructing a second ground water
system and passively treating upper zone ground water to meet discharge limits;
abandoning and closing potentially contaminated wells, and providing an alternative
source of water for any affected residences not serviced by the municipal water system;
continually monitoring the air, surface water, ground water, and biological parameters at
:he site; and implementing institutional controls including land use restrictions to
control future land use, and site access restrictions such as fencing. The estimated
present worth cost for this remedial action is $52,035,000, which includes an annual O&M
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EPA/ROD/R10-92/041
Bunker Hill Mining and Metallurgical Complex, ID
Second Remedial Action - Final
Abstract (Continued)
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific soil excavation goals, which are based on health-risk levels,
include lead 1,000 mg/kg. Soil will be stabilized to meet RCRA LDR standards prior
to disposal in CIA, which will be capped. Clean replacement soil will contain less
than arsenic 100 mg/kg; cadmium 5 mg/kg; and lead 100 mg/kg. Chemical-specific
sediment and debris clean-up levels were not specified; however, materials that cannot
be reprocessed or recycled will be stabilized onsite prior to disposal in CIA.
Chemical-specific ground water clean-up goals are based on SDWA MCLs and state
standards and include arsenic 0.05 mg/l; cadmium 0.005 mg/l; lead 0.05 mg/l; and zinc
5 mg/l. Chemical-specific surface water clean-up goals are based on federal water
quality criteria under the CWA and include cadmium 0.0011 mg/l; lead 0.0032 mg/l; and
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. RECORD OF DECISION
Hunker Hill Mining cmd Met.allu.rgical Complex
Shoshone County, Idaho
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Section
2
3
T ABLE OF CONTENTS
Page
SITE DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
SITE HISTORY AND ENFORCEMENT ACTIVITIES. . . . . . . . . . . . . . . . . 2-1
2.1
2.2
2.3
2.4
2.5
SITE HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
INITIAL INVESTIGATIONS. . . . . . . . . . . . . . . . . . ','. . . . . . . . . .2-5
REMEDIAL INVESTIGATION/FEASIBILITY STUDY. . . . . . . . . . . . 2-6
HISTORY OF CERCLA ENFORCEMENT INVESTIGATIONS. . . . . , . . 2-9
REMOV AL AND RESPONSE ACTIONS. . . . . . . . . . . . . . . . . . . . 2-10
2.5.1 Residential Area Removal Actions. . . . . . . . . . . . . . . . . . . 2-11
2.5.2 Non-populated Area Response Actions. . . . . . . . . . . . . . . .. 2-12 '
2.5.3 U.S. EPA CERCLA Cost7Recovery .' .
and Enforcement Litigation. . . . . ... . ',. . . . . . . . . . . . "'. . 2-14
HIGHLIGHTS OF COMMUNITY PARTICIPATION' ,. . '. .. . . . . .'. . ... . .. .3-1
4
SCOPE AND ROLE OF OPERABLE UNIT. . . '. . . . . . . . . . ". .. . . . . . ...4-1
5
5.1
5.2
6
SITE CHARACTERISTICS. . ~ . , . . '. . . . . . . . . . . . . . .,' . , . . . . . . ... . .5-!
PHYSICAL SETTING. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . 5-1
NATURE AND ,EXTENT .oF CONTAMINATION, .. . ". . ; . . . . : ~ . . .5-4
5.2.1 Contaminan~ of Concern. . . . . . . . . . . . . . . . ': , . . . . . . . ,5-4
5.2.2 Contaminant Sources. . . . . . . . . . . . . . . . . . . . . . , . . : . .5-5
SUMMARY_OF SITE RISKS.. ... . . . . . . . . . . . . .'.. . . . . . . . . . ... .6-1
6.1
6.2
7
HUMAN HEALTH RISKS. . . . . . . . . . ~ . . . '. . . . " . . . . , . . . . . .6-1
ENVIRONMENTAL. RISKS. . . . . . . . . .'. . .'. . . . . . . . . . . . . . . . . 6-7
DETAILED DESCRIPTION OF ALTERNATIVES. . . . . . . . .. . . . . . . . . . .7-1
7.1
.7.2
7.3
7.4
ALTERNATIVE 1 NO ACTION. . . . . . . . . . " . . . . . . . , . . . . . . ,.7-2
ALTERNATIVE 2 SOURCE AND INSTITUTIONAL CONTROLS. . , . . 7-3
ALTERNATIVE 3 SOURCE CONTROLS AND TREATMENT. . . . . . . 7-3
ALTERNATIVE 4 REMOVAL, SOURCE CONTROLS,
AND TREATMENT. . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . .7-3
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Section
8
9
.
.
TABLE OF CONTENTS (Continued)
Pa2e
COMPARATIVE ANALYSIS OF ALTERNATIVES. . . . . . . . . . . . . . . . . . .8-1
8.1
INDIVIDUAL ANALYSES. . . . . . .. . . . . . . . . . . . . . . . . . . . . . .8-1
8.1.1 Alternative 1: No Action. . . . . . . . . . . . . . . . . . . . . . . . . 8-1
8.1.2 Alternative 2: Source and Institutional
Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~ . .8-1
Alternative 3: Source Controls and
Treatment. . . . . . . . . . . . . . . . . . . . . . . . '. . . . . . . . . ...8-3
.8.1.4 . Alternative 4: Removal, Source Controls;
. and Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
COMP ARA TIVE ANALYSIS. . . . . . . . . . . . . . . . . . . .". . . . . . . . . 8-6
. 8.2.1 Protecti()n of Human Health and Environment . . . . . . . . '. '.' . . 8-6 ..
8.2~2 . Compliance with Applicable or Relevant and . .
Appropriate Requirements. . . . ;.. . . . . '." ... . . . . . :.. .. .8-6
Long-Term Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . .8-7
Reduction of Toxicity, Mobility. Volume, ." . .
and Persistence.. .. .. .. . .. ... . . . . . . ... . . . . . . . .. . 8-7
8.2.5. Shon-Term. Effectiveness. . . . . ..". . . . .... . ~ . . . .. . . . . .8-7
8.2.6 Implememability, Reliability, a.,d . .
Constructability . . . . . . . . ... . . . . . . . . . . . . . . . . . . . ; . . 8-8
Cost. . . .' . . . . . . . . . . . . '.' . . . . . . . . . . . .... . . . . . . . .8-8
State Acceptance.. . . . . . . ~. . . . . . . : . '.' . . . . . . . . . . . . .8-8
Community Acceptance. ... . . . . . . . '.' . . . . . . . . . . . .. . . . 8-8
Tribal Acceptance. . . . . . . . . . . ..... . . . .. .. . . . . ~ . . .. 8-8
8. 1.3
8.2
8.23
8.2.4
8.2.7
8.2.8
8.2.9
8.2.10
THE SELECTED REMEDY. . . . . . . . ... . . . . . .' . . . . . . . . ... . . . . . . . .9-1
9.1
9.2
INTRODUCTION. . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .9-1
REMEDIAL ACTIONS BY SUBAREAS. . . . . . . . . . . . . . . . . . . . . . 9-1
9.2, 1 Hillside Remedial Actions. . . . . . . . . . . . . . . . . . . . . . . .. 9-2.
9.22 Smelterville Flats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-3
9.2.3 Central Impoundment Area. . . . . . . . . . . . . . . . . . . . . . . . . 9-4
9.2.4 Page Pond. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-5
9.2.5 Smelter Complex and Mine Operations Area. . . . . . . . . " . . . 9-5
9.2.6 RightS-of..Way. .. . . . . . . - . . . . " " . . . " . . . . . . . . . . . 9-11
9.2.7 Commercial Buildings 3:nd Lots. . . . . . . . . . . . . . . . . . . . . 9-12
9.2.8 Residential [ntenors . . . . . . . - . . " . . . . . . . . " . . . . . . . . 9-12
9.2.9 Future Development in Non-populated Areas. . . . . . . . . .. . . 9-13
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TABLE OF CONTENTS (Continued)
Section
Page
9.2.10
9.2.11
9.2.12
9.2.13
Constructed Wetland Treatment Systems. . . . . . . . . . . . 9-13
Public Water Supply Considerations. . . . . . . . . . . . . . . 9-14
Soil Action Levels. . . . . . . . . . . . . . . . . . . . . . . . . . 9-15
Operations and Maintenance Requirements. . . . . . . . . . . 9-15
Institutional Controls. . . . . . . . . . . . . . . . . . . . . . . . 9-16
Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . : . . . 9-18
General Remedial "Design/Remedial Action
Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19 "
CHANGES TO PROPOSED PLAN. . . . . . . . . . . . . . . . . . . . . . 9-20
QUANTITY OF MATERIALS REMOVED, CONTAINED, AND
TREATED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20
9.5 COST. . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .9-29
9.6" PERFORMANCE REQUIREMENTS. . . . . . - . . . . . .. . . . . . . . 9-35
9.2.14
9.2.15
9.2.16
9.3
9.4
10
STATUTORY DETERMINATIONS. . . . . . . .". . . . ". . . ~ . . . . . . . . . . 10-1
10."
PROTECTION OF HUMAN HEALTH AND THE:
ENVIRONMENT. . . . . . . . . - . . . . . . . . . . . . " . . . . . . . . . . 10-1
COMPLIANCE WITH APPLICABLE OR ......"."......... 10-1
COST-EFFECTIVENESS. . . . . . . . . . . . . . . . . . . . . . . . . .. 10-35
UTILIZATION OF PERMANENT SOLUTIONS "
AND ALTERNATIVE TREATMENT TECHNOLOGIES TO
THE MAXIMUM EXTENT PRACTICABLE. . . . .". . . . .". . . " 10-35
PREFERENCE FOR TREATMENT
AS A PRINCIPAL ELEMENT. . . . . . . . . . . . . . . . . . . . . . " 10-36
10.2
10.3
"10.4
10.5
11
REFERENCES AND ACRONYMS. . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
APPENDIX A BUNKER HILL RESPONSIVENESS SUMMARY
APPENDIX B DEPARTMENT OF THE INTERIOR COMMENTS
APPENDIX C COEUR d'ALENE TRrBE OF IDAHO COMMENTS
ON THE PROPOSED PLAN
APPENDIX D COEUR d'ALENE TRIBE OF IDAHO COMMENTS ON THE RI/FS
APPENDIX E COMMENTS FROM THE POTENTIALL Y RESPONSIBLE PARTIES
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Figure
1-1
1-2
1-3
6-1
9-1
Table
2-1
2-2.
5-1
5-2
5-3
5-4
5-5
5-6
5-7
6-1
6-2
6-3
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LIST OF FIGURES
Page
Bunker Hill Superfund Site Location in Idaho. . . . . . . . . . . . . . . . . . . . . 1-3
The Bunker Hill Superfund Site. . . . . . . . . . - - . . . . . . . . . . . . . . . . . . 1-4
Bunker Hill Superfund Site General Features with
Five Major Non-populated Subareas,
Industrial Facilities, and Subunits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Major Areas Containing Meta! Concentrations
That May Induce Toxicological Effects .on Plants,
Soil, Invertebrates, and Small Mammals. . . . . . . " . . . . . - . . . . . . . . . 6-10
Material Accumulation Flow Chart. . . . . . . . . . . . . . . . . . . . . . - . . . . . 9-7 ,
LIST OF TABLES
Major Features and Investigation Emphasis . ~ . - . '. . . . . . . . .'. :' .'. .'. . . - 2-8
Potentially Responsible Parties Identified for the' , "
Bunker Hill Superfund Site - . - . . . . . ". . . . - - . . . . - . . . . . . . . .'. . . 2-10
Ma:
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Table
6-4
7-1
8-1
8-2
9-1
9-2
9-3
10-1
10-2
10-3
10-4
10-5
10-6
, LIST OF TABLES (Continued)
Page
Soil Toxicity Reference Concentrations That May Induce
Toxicological Effects on Plants, Soil Invertebrates,
and Small Mammals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-9
Summary of Site Wide Remedial Action Alternatives
by Subarea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4
Comparative Analysis of Altematiaves . . . . . .". . . . . . . . . . . . . . . . . . . . 8-2
Summary of Costs. . . . .'. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-9
Principal Threat Action Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
, Estimated Quantities Area-Specific Remedial Actions "
for Selected Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-21
Summary of Estimated Costs for Selected Remedy. . . . . . .' . . . . . . . . . . . 9-30
Federal Chemical-Specific ARARs .;......................... 10-8
Federal Location-Specific ARARs . . . . . . . . . . . . ; . . . . . . . . . . . . :'. 10-13
Federal Action-Specific ARARs .......... . . . . .. . . . .". . . . .. .. 10-18
State of Idaho Chemical-Specific ARARs """"""""""" 10-29
State of Idaho Location-Specific ARARs . . . . . . . . . . . . . . . . . . . . . . . 10-30
State of Idaho Action-Specific ARARs . . . . . . . '. . . . . . . . . . . . . . . . . 10-32
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME
Bunker Hill Mining and Metallurgical Complex Site
WCATION
The Site is a lwenly-one square miie area located in Shoshone County, Idaho. The cities'
of Kellogg, Smelterville. Wardner and Pinehurst are located within the Site.
STATEMENT OF BASIS AND PURPOSE.
This decision document presents the remedial actions selected by the U.S.' Envirohmental
Protection Agency (EPA) and the Idaho Department of Health and Welfare (lDHW) for
the Non-populated Areas of the Bunker Hill Mining and MetallurgiCal Complex Site, as . .
well as those aspects of the Populated Areas that were not addressed in the Residential
Soils Record of Decision (August, 1991). The remedy was chosen in .accordance with
CERCLA, as amended by SARA,. and, to the extent-practicable. the National
Contingency. Plan. This decision is based on the Bunker Hill Sitewide Administrative
Record file for this Site. The Administrative Record Index is.available.in the EPA
Region 10 Records Center and the Kellogg Public Library- . .
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by .
implementing the response actions selected in this Record of'Decision (ROD), may
present an imminent and substantial endangerment to public health, welfare, or the
environment. .
DESCRIPTION OF THE REMEDY
The remedial actions described below will eliminate, or reduce to acceptable levels, the'
exposure pathways at the Site. Together this ROD, and the Residential Soils ROD,
prescribe a protective site-wide remedy for the Bunker Hill Mining and Metallurgical
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The highlights of the selected remedial actions are presented below by Subarea:
.
.
.
.
.
Hillside Remedial Actions
.
Revegetation of Hillside areas with less than 50% cover
Contour terracing of eroded Hillsides
Erosion control structures
Re-establish riparian habitat
.
.
.
Smelterville Flats
.
Mitigation of eroding tailings in the SFCDR flood way
Consolidation of selected jig tailings into the CIA
Establish soil barriers in contaminated areas and revegetate
.
.
Central Impoundment Area (CIA)
.
Consolidation of jig tailings removed during other -remedial actions
Closure with a low permeability cap -
Remove material accumulations from 1982 Smelter cleanup and consolidate-
within the Smelter Closure. - .
Relocate slag pile to either CIA or Smelter Complex
Collection and treatment of "CIA seeps"
.
.
.
.
Page Pond
.
Move tailings from West Page Swamp to Page Pond and cap
Cap Page Pond benches with residential soils
Maintain access controls (fencing)
Channel improvements to Humboldt and Grouse Creeks
.
.
.
Smelter Complex and Mine Operations Area (MOA)
.
Reprocess, recycle or treat all Principal Threat materials
Removal and recycling of salvageable items -
Demolish structures
Decontaminate structures not demolished
Cap Lead Smelter and Zinc Plant with low permeability cap
Collect and treat Lead Smelter and Zinc Plant closure leachate
Place contaminated material under caps (phosphoric acid plan debris,
boneyard materials, contaminated soils, etc.)
.
.
.
.
.
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.
I
.
.
.
.
.
Treat acid mine drainage from the Bunker Hill Mine in the Central Treatment
Plant prior to discharge to Wetlands treatment system
Recover and treat ground water in Government Gulch
Relocate A-I gypsum pond to CIA
Cap A-4 gypsum pond, or consolidate within the CIA
Close solid waste landfills
.
Rights-of-Way
.
Implement access controls, and provide for a barrier consistent with land use
or removal/replacement
.
Commercial Buildings and Lots
.
Barriers, or removals, consistent with land use on all property with lead
concentrations over 1000 ppm
.
Residential Interiors
. Continue blood lead monitoring
. . Continue high efficiency vacuum loan program
. Clean all homes exceeding 1000 ppm lead house dust after remedial actions
are completed , '
. Home interiors of children identified through health screening will be
evaluated, and if needed, site specific remediation implemented' ..'
. Develop and implement interior dust monitoring prpgram
.
Future Development in Non-populated Areas
.
Implement remedial actions based upon current land use
Through institutional controls, install necessary barrier wheR' iand use changes
.
.
Constructed Wetland Treatment Systems
.
Collected Water Wetland in Smelterville Flats for treatment of selected
surface water sources, CIA seeps, and Government Gulch groundwater, 74
acres in size
Ground water wetland in Pinehurst narrows for treatment of ground water,'34
acres in size
.
.
Public Water Supply Considerations
.
Abandon and close potcntially contaminated wells ,
Provide an alternative source of water for any well used for drinking water
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.
.
r
.
Operations and Maintenance Requirements
.
Provide for long-term O&M of selected remedial actions
.
Institutional Controls
Environmental Health Code
Performance standards
Educational programs.
Testing and monitoring
Monitoring
.
.
.
.
.
.
Air
Surface water
Ground water
Biological Parameters
.
.
.
STATUTORY DETERMINATIONS
. .
. .
The selected remedy is protective of human health and the. environment, will. comply with
federal and state requirements that are legally applicable or relevant and appropriate:
(unless the contingent waiver discussed in Section 10.2 is invoked), and is cost..effective.
The selected remedy utilizes' alternative treatment and. resource recovery technologies to
the maximum extent practicable. Because this remedy will.result in h~dous supstances.
remaining onsite above health-based levels, a review will be conducted within the . .
five-years after commencement of remedial actions to ensure ~at. the remedy continues to
provide adequate protection .of human health and the environment..
~~op([2e---
Richard P. Donovan
Director
Idaho Department of Health and Welfare
k;/ d- /, /'1",;t-
Date /
~~
Dana A. Rasmussen
Regional Administrator
U.S. EPA Region 10
0;/22../97..
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II
...
RECORD OF DECISION SUMMARY
Site Name:
Bunker Hill Mining and MetallurgiCal Complex Site
Location:
Shoshone County, Idaho
I SITE DESCRIPTION
The Bunker Hill Mining and Metallurgical Complex Superfund Site (Site) is located in
Shoshone County, in northern .Idaho, at 47"5' north latitude and 116°10' west longitude
(Figure I-I). The Site lies in the Silver Valley of the South Fork of the Coeur d'Alene River
(SFCDR). The Silver Valley is a steep mountain valley that trends from east. to west
approximately 2,250 feet above mean sea level. Interstate Highway 90 crosses through the
valley, approximately parallel to the SFCDR.
The U.S. Environmental Protection Agency (U.S. EPA) and Idaho Department of Health and
Welfare (IDHW) (the agencies), have designated a 21-square-mile study area as the Site for
purposes of conducting the Remedial Investigation/Feasibility Study (RIIFS), which has been
divided into Populated Areas and Non-populated Areas. This Record. of Decision (ROD)
addresses {;ontaminated Non-populated Areas of the Site and those aspects of the P9Pulated
Areas not covered under the Residemiai SoiJ ROD (August 30, 1991). .The Site includes the.'
town of Pinehurst on the west and the town of Kellogg on the east (Figure 1-2) an~ is centered
on the Bunker Hill industrial complex. The Site has been impacted by over 100 years of
mining and.65 years of smelting activity.
Soils, surface water, ground water, and air throughout the Site have been con~minated by
heavy metals, to varying degrees, through a combination of airborne particulate deposition,
alluvial deposition of tailings dumped into the river by mining activity, past waste disposal
practices, and contaminant migration from onsite sources. Onsite sources include the industrial.
complex, tailings and other waste piles, material accumulation sites, barren hillsides, and
fugitive .dust source areas located throughout the Site. Other contaminants include
Polychlorinated Biphenyls, PCBs, and Asbestos. The industrial complex consists of:
. The mine, milling, and concentrating operations (This area is designated
"A" on Figure 1.3)
.
A large tailings impoundment area (B)
.
A lead smelter (C)
.
A phosphate fertilizer platH (D)
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..
""
. Three sulfuric acid plants (E)
.
An electrolytic zinc plant (F)
.
Several large hazardous materials accumulation sites created throughout
the Site's history to store both mine and mill tailings, smelter wastes,
and by-products
Other onsite sources of contamination will be discussed later in the text.
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.
IDAHO
S H 0 S H 0 NEe 0 U N T Y
(B
...
I
w
COEUR
D'ALENE .
.0 BOISE
Sourco: Adapted USEPA 1990a
BUNKER HILL SUPERFUND SITE LOCATION IN IDAHO
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~
f~
. :-;
"
~.
~
....
~\-
::::
.;::::
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E:-
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SOUTH HILLSIDES
. .
ihrcc..milc by seven-mile boundnrles
--
~ NOR"rH HIL~'t1~
,~ ~. ~-~
., ~ ~ J
SUELTERVn.LEFLATS ~ ~ ~ ~ ~'\..'\..'\..~
. L --d... '\... '\.. ~ ~
. CENTRAl.. ,,~ &
. T f/dPOVNDMEHT) ~
- S)l.ELTERVtLL~r .~ A~ .--/, ~.
':$:. 'I r LEAD""""" ;'
SYELfER I(1lJ. r ~ .
ZINC.
: SMELTER . KELLOCC
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PAGE,
.
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Source: Horhon, Inc, Dlella' ).lap Dab. Aerie.! Pbolo Dall ,7/8~
THE 'BUNKER' HILL SUPER~lJND SITE
FIGURE L 2.
. '
,
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.
.
-
I
U1
NORTH HILLSIDES'
(II) M"UI.. Millln,. II.IId C"CCIIIn~on
Opc~~...
(8) T.Uinp I mp"""dmeo. """'"
(C) Lcd Sm."',
(D) !'hoop"" F.l'Iilhc, Pbnt
(I!) Throe Sultuno Acid Pion"
(P) An BI......lydo 2lac Pe'
8
PIMCHURS I
~
N
I
SOUTH HILLSIDES'
ApproLirnd. Throe-mil. by' aoyon-mllo Doundule.
.. . t .
Sourcel Horl~oDa IDe;" DIKILoI "\lap DalA, A.rI.1 Pbot.o Dolt 7/a~
BUNKER HILL SUPERFUND SITE GENERAL FEATURES
WITH FIVE MAJOR* NON-POPULATED SUBAREAS,
INDUSTRIAL FACILITIES, AND SUBUNITS
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2 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 SITE HISTORY
The Bunker Hill Superfund Site encompasses 21 square miles along Interstate 90 in the Silver
Valley area of Northern Idaho (Figure 1-2). The Site encompasses the now inactive Bunker
Hill Mining Complex and former metallurgical and smelting facility (the Bunker Hill
Complex); the cities of Kellogg, Pinehurst, Smelrerville, and Wardner; and the residential
areas of Page, Elizabeth Park, and Ross Ranch. .
The Bunker Hill Site is part of the Coeur d' Alene Mining District located in northern Idaho
and western Montana. Mining for lead, zinc, silver, and other metals began in 1883. The
first mill for processing lead and silver ores at the Bunker Hill Complex was constructed in
1886 and had. a capacity of 100 tons of raw ore per day. Other mills subsequently were built
at the Bunker Hill Complex and the milling capacity ultimately reached 2;500. tons per day.
Before the widespread use of ponds to contain milling waste. products, tailings were often
. disposed of in local surface waters. The South Fork of the Coeur d'Alene River received
tailings in this .manner from numerous mines. and. mills in the. Silver Valley both in and
upstream of the Site. Dams conStructed to retain tailings witliin the floodplain of the SFCDR, .
as well as subsequent flooding caused the tailings to be spread throughouuhe valley.floor. .
The first tailings impoundments ir. the Silver Valley were located at the Bunker Hill Complex.
The Bunker Hili mine taiHngs impoundment, known as the Central Impoundment Area (CIA)
was originally constructed .in 1928. The CIA is contained in a ring dike structure. built on
mine waste rock and other materials. It is presently 60 to 70 feet high, divided into three
major cells, including the east cell, the gypsum pond and -the slag pile.. A small portion of the
east cell is presently in use and 'receives acid mine drainage from the Bunker Hill mine which
is subsequently pumped to the Central Treatment .Plant (CTP) for pH adjustment and, metals
removal prior to di~charge to Bunker Creek~ In 1926, the 70 acre Page. Pond .tailings
impoundment, located within the Site, began operation. . It is currently closed, although a
wastewater treatment plant, including four unlined lagoons and a 17 acre stabilization pond,
was constructed on the impounde9 tailings and is in operation. Upstream mines were using
tailings ponds by the 1960s. . .
From 1886 until 1917, .the lead and silver concentrates produced at the Bunker Hill Complex
were shipped to offsite smelters for processing. Construction of the lead smelter began in
1916 and the first blast furnace went online in 1917 producing lead, cadmium, silver, and
alloys of these heavy metals. Over the years, the smelter was expanded and modified. At the
time of its closure in 1981, the lead smelter had a capacity of over 300 tons of metallic lead
per day. Smelting operations resulted in fugitive and stack emission of metals and. sulfur
dioxide which were deposited throughout the Site.
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An electrolytic zinc plant was put into production. at the Site in 1928. The zinc plant was
owned and operated by the Sullivan Mining Company; until 1955, both the Bunker Hill and
Sullivan Mining Company and Hecla Mining Company had a 50% interest in the Sullivan
Mining Company. By 1956, the zinc plant was.wholly owned by Bunker Hill. Two sulfuric
acid plants were added to the zinc facilities in 1954 and 1966, and one sulfuric acid plant was .
added to the lead complex in 1970. When it was closed in 1981, the zinc plant's capacity was
approximately 310..tons per day of cast zinc. A phosphoric acid plant was constructed at the
Site in 1960 and a Jertilizer plant wasbuUt in 1965. The primary products from these plants
were phosphoric acid and pellet.;type fertilizers composed of varying mixtures of nitrogen and
phosphorus. The industrial complex ceased operation in 1981 except for limited mining and
milling operations which resumed from 1983 through 1986, and later from 1988 until 1991, as
described below.
The Kellogg-based Bunker Hill and. Sullivan Mining Company, incorporated in 1887, was the .
original owner and operator .of the Bunker llill Complex. . In 1956, the. Bunker Hill and
Sullivan Mining Company changed its name to the Bunker Hill Company and in. 1968, Gulf
Resources & Chemical Company (Gulf) of Houston, Texas, merged ~th the company. Gulf.
operated the Bunker Hill mine and smelter facilities until1ate 1981, whel). it shut down the
entire facility. .
As a result of damming the river to impound tailings from flowing downstream~. the reworking .
of jig tailings, historic smelter romplex waste diScharge and runoff as well ~ the periodic
flooding of the river, waste rnaterial1aden with lead, zinc, cadmium, arsenic and other heavy .
metals was deposited onto the valley floor. Surface water, ground water,. and soils have all .
been impacted by metals contamination. . .
By the early 1970s~ emissions from the lead smelter .and zinc plant, including sulfur dioxide,
total suspended particulates, lead and other heavy metals,. contributed significantly to
contamination of the surrounding area. Although both the lead smelter stacks utilized. a
baghouse to capture I@l1iculates, stack lead emission rates at the facility averaged from lO.to08
per month to about 15 tons per month through the 1960s. After a September, 1973 fire in the
. baghouse at the lead smelter main stack,. air .pollutioncontrol capacity was severely reduced
and there was a dramatic increase in emissions. Total particulate emissions of about 25 to
over 140 tons per month, containing 50 to 70 percent lead, were reported from the time of the
fire through November 1974. During the first three months of 1974, approximately 73 tons of
lead per month were emitted into the environment, with airborne lead .levels as high as 30
micrograms per cubic meter on a monthly average being reported. The baghouse was
reconstructed in mid-1974.(Interim Site Characterization Report, 1986.) .
The immediate health effects of increased total lead emissions following the baghouse fire we:~
observed in 1974 and 1975 U.S. EPA-Silver Valley Lead Health Studies. These
comprehensive public health studies documented elevated blood lead levels in a significant
number of children. Ninety-eight percent of 179 one to nine year old children living in the
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,.
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highest exposure area near the smelter had blood lead levels above 40 micrograms per deciliter
(J-Lg/dl), while forty percent exceeded 80 ",g/dl. One of the children tested, who had a blood
lead level of 164 ",g/dl, subsequently sued the Bunker Hill Company in 1977 for lead
. poisoning and related injuries. Other children with high blood lead levels also were plaintiffs' 0
in that lawsuit as well as a later similar action. 00 Ultimately, the cases were settled. In October
1981, Gulf Resources & Chemical Corporation agreed to pay several of these children
approximately $8.8 million through an ongoing trust fund. Voss et a!. v. The Bunker Hill
Company et aI., Civ. No. 77-2030 (D. Idaho, 1981). Blood lead testing has continued at the 0
Site with the results summarized in numerous U.S. EPA and IDHW reports, as described in
Section 2.2 below.
In 1977, a 715 foot tall stack was constructed at the lead smelter and a 610 foot tall stack was
installed at the zinc plant in an effort to disperse contaminants from the complex. The stacks
decreased sulfur dioxide concentrations in the late 1970s, although building ventilation and
fugitive emissions were estimated to be at least as great as thesta~k emissions. The smelter
and other Bunker Hill Company activities ceased operation in late 1981. At that time, portions
of the smelter complex were salvaged for various materials, and scrap.
On November 1, 1982, the Bunker Limited' Partnership (BLP) purchased "the Bu'nker Hill
.Complex and related real property from Gulf. . At that time G,:,lf changed the name of the
-Bunker Hill Company to the Pintlar Corporation, which remains in existence to this date.
Bunker Hill Properties, Inc., a Delaware' corporation,' is the general. partner of BLP. There.
were originally four limited partners of .BLP: H, F. Magnuson, Simplot Development
Corporation, Hagadone-Idaho; Inc. and Jack W. Kendrick, .ali of whom also owned val)'ing .
amounts of stock in Bunker Hill Properties, Inc. . Simplot Development Co~ration
subsequently withdrew from BLP. Since 1984, there have been several transfers of the Jimited
parinership interests in BLP. and exchanges of stock in Bunker Hill. Properties, Inc. to several
newly created corporations of the original limited partners as well as to other related or
affiliated entities. 0
. .
BLP's 1982 acquisition from Gulf included the Bunker Hill mine and related smelter complex
facilities, a 50% interest in the Star Unit Area (with Hecla Mining Company controlling the
other 50%), the Crescent Silver Mine, approximately 24,500 acres of timberland in Shoshone
County and Kootenai County, Idaho and Pend Oreille County, Washington, and approximately
9,500 acres of real property in and around Kellogg, Idaho. including the 350 acre Bunker Hill
Complex and mountainous property it leases to the City of Kellogg for the Silver Mt. Ski
Area. BLP also took over the former Bunker Hill Company headquarters offices in Kellogg.
BLP reopened the Crescent Silver Mine ion late 1983, and operated it until mid-1986. BLP
incorporated Crescent Silver Mines, Inc. on July 20, 1984, and Syringa Minerals Corporation
(Syringa) on March 21, 1986, as wholly-owned subsidiaries. BLP subsequently transferred
certain mining and real property holdings to Syringa, including the Bunker Hill Mine, the
smelting and refining facilities, concentrator, and wastewater treatment plant. BLP transferred
the Crescent Mine to Crescent Silver Mines, Inc. On August II, 1987, Syringa incorporated
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Minerals Carporatian .of Idaha (MCI), a Washingtan carporatian, ta which it transferred
numeraus smelter camplex haldings, including but nat limited ta the lead smelter, zinc plant,
silver refinery, cadmium plant, phaspharic acid and phasphate fenilizer plant, sulfuric acid
plant, and part .of the Central Impoundment Area,. while distributing MCI stock ta BLP. . On
December 31, 1987, Crescent Silver Mines, and Syringa merged inta the Bunker Hill Mining
Campany (U.S.), Inc., a whally-awned subsidiary .of the Bunker Hill Mining C.ompany, a
Canadian c.orporati.on inc.orporated in British C.olumbia an June 25, 1987.
The Bunker Hill Mining C.ompany (U.S.), Inc. (BHMC) reopened the Bunker Hill mine in
September 1988, with financing .obtained thr.ough the sale .of $7.2 millian .of public shares .of
stock sold .on the Vanc.ouver Stock Exchange in May 1988. As L'1e price .of zinc rase in 1989,
BHMC sold additianal shares .of stock and raised mare capital far a planned expansi.on .of the
mine. F.oll.owing a 1990 drop in prices far zinc, silver, and lead, BHMC could n.o l.onger meet
financial .obligati.ons. 00 January 17, 1991, BHMC filed far relief under Chapter 11 .of the
U.S. Bankruptcy Code and ceased .operati.ons. .
BLP filed far Chapter 11 Bankruptcy protecti.on an June 28, 1991. . Alth.ough BLP.continued t.o
contr.ol. aver $20 milli.on in timberlands (in part encumbered by am.ortgage .of appr.oximately
$10 milli.on) and ather assets at the Bunker Hill C.omplex and thr.ough.out n.orthern Idah.o, it
filed far. bankruptcy as a result .of litigatian commenced in 1987 .byGulf Resources &
Chemical C.orporatian aver liability far the .medical and.pq1si.on benefits..of the. farmer Bunker
Hill warkers. Pintlar Carooratian and Gulf Res.ources & ChemicalCaq>oratian. v.Bunker .
Limited Partnership etal., No. 90976 (Faurth Judicial District .of Idaho). On June 13;1992,
Gulf succeeded in .obtaining prejudgmerit attachment liens on 24,500 acres .of BLP's
timberlands based an. its $60. millian claim against BLP far warkers' pensian and medical
payments which Gulf alleged BLP was liable far as a result .of its breach .of the 1982 purchase
contract with Gulf. BLP filed far bankruptcy pratectian shartly thereafter. .
BLP and BHMC are presently in the process .of liquidating their assets and selling all .of their.
remaining praperty pursuant ta naw final Bankruptcy Plans. . As described in Sectian 2.5.3
belaw," a substantialportian .of bath BHMC's and BLP's assets are being used far cleanup .of
the Bunker Hill Camplex pursuant ta Administrative Orders issued by U.S. EPA..
The Bunker Hill Camplex is still largely awned, .operated, and con traIled by'BLP as the debt.or
in possessi.on alang with. its general partner BH Praperties, Inc. and whaUy-.owned subsidiary,
Minerals Carparatian .of Idaha, and by BHMC as the debtar in possessian .of the Bunker .Hill
mine .operating area. BHMC has saId several properties at the mine aperatians area ta variaus
entities and individuals. including the Bunker HiU mine partal. BLP has said certain ather
praperty at the Bunker Hill Camplex and in and araund Kellagg t.o variaus entities and
individuals. In additian. certain property .of Minerals Carporatian was acquired by the Pintlar
Carparatian pursuant ta BLP's cantirmed Chapter 11 Bankruptcy Reorganizatian Plan. . BLP
has alsa executed several .optians with Pintlar C.orporatian ta sell property awned by it and its
subsidiary Minerals Carparation .of Idaha, including property surraunding the lead smelter and
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zinc plant. . There are currently no known active mining or other mineral production activities
at the Bunker Hill Complex.
Over the past 10 years, BLP, BHMC and their subsidiaries and predecessors have shipped a.
variety of wastes offsite for salvage, recycling, and disposal. Thousands of tons of sludge,
tailings, flue ~ust, and other wastes remain at the complex.
Contamination at the Site was characterized during Remedial Investigation/Feasibility Studies
(RI/FS) conducted from 1987 to 1992. Risks to human health were evaluated through the Risk
Assessment Data Evaluation Report (RADER), October 1990, and the Human Health Risk
Assessmem (HI-IRA), May 1992. Risks to the environment w~re evaluated in the Ecological
Risk Assessment (ERA), November 1991. .
2.2 INITIAL INVESTIGATIONS
Contaminated air, soils, and dusts have been identified as contributors to elevated blood lead.
levels in children living in the Populated Areas of Site. Environmental media concentrations of
Site contaminants of concern in the Populated Areas are strongly dependent on distance .from
the smelter facility and industrial complex~ Residential areas nearest the smelter complex have
shown the greatest air, soil; and dust lead concentrations; the highest childhood blood lead.
levels; and the greatest. incidence of excess absorption in each of the studies conducted in the
last decade.. .., .
He.alth effects of environmental contamination were first documented following the .,smelter .
baghouse fire in 1973 and associated smelter emissions in .1973 and .1974. 1n an August .1974 ..
survey, 98 percent of the 1- to 9-year-old children living within I mile of the: .smelter ..were' . .
found to have blood lead levels in excess of 40 J.'gtdl. . The. -frequency. of abnormal lead
absorption (defined at the time as.greater than or equal to 40 ILg/dl) was found to'decrease with.
increasing distance from the smelter. Several local children were diagnosed with clinical lead
poisoning and required hospitalization. Lead health surveys conducted throughOut the rest. of
the 1970s confirmed that excess blood lead absorption was endemic to this community. . .
Concurrent epidemiologic and environmental investigations conduded that atmospheric
emissions of particulate lead from the active smelter were the primary sources of.
environmental lead that affected children's blood lead levels prior to 198 L' Contaminated soils
were also found to be a significant, secondary source of lead to children ~n the 1 970s.
Following lead poisoning incidents in 1973-74, a number of activities were instituted to
decrease lead exposures and uptakes in the community. Emergency measures were initiated to
reduce the risk of lead intoxication. These measures included: chelation of children with
blood lead over 80 J.'g/dl, purchase and. destruction of as many homes as possible within 0.5
mile of the smelter, distribution of "clean" soil and gravel to cover highly contaminated areas,
initiation of a hygiene program in the schools, and reduction of ambient air lead levels through.
reduction of smelter emissions. Street cleaning and watering in dust-producing areas occurred
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during several periods in the late 1970s. Subsidies were provided by the Bunker Hill
Company to residents for the purchase of clean top soil, sand, gravel, grass seed, and water;
thereby promoting some yard cover in the community- '
, An analysis of historical exposures to children who were two years old in 1973 suggests a high
risk to normal childhood development and metal accumulation in bones because of extreme
exposures; these exposures could pose a continuing lead body burden in these children because
of its long physiologic half life. Females who were two years of age during 1973 are now of
childbearing age and, even with maximum reduction in current exposure to lead,the fetus may
be at risk because of resorption of bone lead stores in the young women. A TSDR is currently
evaluating the feasibility of reconstructing this cohort of individuals to determine their past
health experience. If accomplished this might lead to improved health care through education
of both patient and physician.
Following smelter closure in late 1981, airborne lead contamination decreased by a factor of
about 10, from approximately 5 p,g/m3 to 0.5 p.g/m3. A 1983 .survey of children's blood lead
levels demonstrated a significant decrease in community exposures to lead contamination;
however, 'the survey also found that several children, including. some born since 1981,
continued to exhibit blood lead levels in' excess of recommended' public health criteria.
Accompanying epidemiological analyses suggested that contaminated soils and, dusts
represented the most accessible sources of environmental lead in the community. , . .
Childhood mean blood lead levels have continued to decrease since 1983. These decreases are
iikely related to a nation wide reduction in dietary lead; reduced 'soil, dust, and air levels in the'
community; inrake reductions achieved through denying access to source~; and the increase in
family and personal hygiene practiced in the community. The latter is. ,reflected in the
implementation of a comprehensive Community Health ~nterVention Program in 1984 that
encourages improved hygienic (housekeeping) practices. parental, awareness, and special,'
consultation on individual source control practices such as lawn care. The Community HeaLth, '
Intervention Program was initiated specifically to reduce the potential for excess absorptions
. and minimize total absorption in the population. Total blood lead absorption among the.com-. .
munity's children has been reduced nearly 50 percent since 1983. The incidence of lead
toxicity (blood lead> 25 p.g/dl) has fallen from 25 percent to less than 5 percent for children
in the highest exposure area.s. Recent blood lead monitoring has shown approximately 20.
percent of area children surveyed exceed the blood lead level of 10 p,g/dl.
2.3 REMEDIAL INVESTIGA TION/FEASIBILITY STUDY (RifFS)
The Site was placed on the National Priorities List (NPL) in September 1983 (48 FR 40658).
RIIFS activities were initiated in late 1984 following completion of the 1983 Lead Health
Study.
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The Bunker Hill Site Characterization Report (SCR) was the tirst step in the RI process., The
objective of the SCR was to describe and analyze existing information. The existing
information included files from federal, state, and local' agencies, as well as information
obtained from past and present owners and operators of the industrial complex. The SCR was
then used to identify data gaps and deyelop wor~ plans for the remedial investigation., '
In recognition of the history and complexity of this Site, and the continuing need for active
health intervention efforts, the U.S. EP A and IDHW developed an integrated project structure
for RIfFS activities. The Site was divided into two study areas, the Populated Areas and the
Non-populated Areas. The Populated Areas include four cities, residential and commercial
properties located within those cities, and other residential properties. The Non-populated
Areas include the smelter complex, river floodplain, barren hillsides, ground water, surface
water, air, and industrial waste components of the Site. '., ",:","
While separate RIIFS efforts were initiated for each portion of the Site, U.S. ,EPA retained
oversight and risk assessment. responsibilities for both portions. IDHW' performed' the
Populated Areas RIfFS. The Non'-populated' Areas RIfFS was performed by Gulf Resources &
Chemical Corporation (Gulf U.S.A. CorporationfPintlar) ,under a 'May: J987 U;S. EPA
Administrative Order on, Consent ,(1085-09-09-104). Subsequently, additional PRPs; including:'
, Asarco Incorporated, Callahan Mining Company, Coeur d' Alene Mines Corporation, Hecla,
Mining Company, ,Stauffer Management Company, Sunshine Mining Company, Sunshine
Precious Metals Company, and Union Pacific Railroad participated in developing deliverables
for theFS. Table 2-1 lists the major geographic features and investigation emphases.' ,
In order to thoroughly investigate the contamination of Site wide soils, surface water, ground
water, and air,. the Non-populated Rl/FS Work Plan subdivided the Site into'five major areas:
Hillside Areas, Smelterville Flats, Page Pond, Central. Impoundinent .Area (CIA), and' ,the,
Smelter Complex., Based upon a proposal by the PRPs to develop' a comprehensive FS.
portions of the Popu'lated Areas not covered in the Residentia! Soil Feasibility Study (RlIFS)
prepared by CH2M Hill for the lDHW were addressed in the' Non-populated RIIFS. These
modifications included: the addition of areas 'nOt previously defined' as separate, areas,
including rights-of-way (ROW) within the Populated areas of the Site; currently undeveloped
areas which are likely to be developed; commercial buildings and lots; and, residential house
interiors. An additional modification was the separation of the Smelter Complex into two
areas delineated in the RIIFS Work Plan 'as the Smelter Complex, and the Mine Operations
Area (MOA). The identified subareas within the Non-populated areas of the Site include:
1.
2.
3.
4.
5.
6.
7.
8.
Hillside Area;
Smelterville Flats;
Central I mpoundment Area;
Page Pond;
Smelter Complex;
Mine Operations Area;
ROW within the Non-populated Areas; and.
Future Development.
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.
. Pinehurst
. Page
. Smelterville
. Kellogg
. Wardner
. Ross Ranch
. Elizabeth Park
Populated Areas
.. Contaminated Soils and Dust
. Residential Properties
. Commercial Properties
. Roadways/Railways
. Fugitive Dust Sources
. House Dust
~ Airborne Contamination
. Hillsides
. Bunker Hill Smelter Complex Area
. Central Impoundment Area (CIA)
. S mei terville Fiats
. Mine Operation Area
. River Channel Area
. East Page Swamp
. West Page Swamp
. Page Pond
Non-populated Areas
. . Soil and Surface Materials
. Surface Water
. Ground Water
. Air! Atmospheric Transport
.. Vegetation. . .
. BuildingsiProcess Equipment
. Material Accumulation Site
. Contamination at Depth
. Contaminant Migration
The three populated areas of the Site added to the Non-populated RIIFS include:.
9. Commercial Buildings and Lots;
10. ROW within the Populated Areas; and,
11. Residential house interiors.
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2.4 HISTORY OF CERCLA ENFORCEMENT INVESTIGATIONS
Since the beginning of mining in 1885.and smelting operations in 1917, large quantities of a
variety of waste products, including process tailings, flue dust, slag, and airborne emissions
have been released into the environment at the Site. These wastes contain lead, cadmium,
zinc, copper, arsenic, antimony, mercury, silver, and other metal elements. Large quantities
of these waste products remain in the environment in and around the Bunker Hill Superfund
Site, including in the residential soils within the populated areas of the Site.
. "
u.S. EPA began its CERCLA enforcement investigations at the Site in 1983. Since that time,
U.S. EPA has conducted numerous investigations regarding those persons or parties which
may be responsible for the payment or response costs pursuant to Section 107(a) of the
_<::~mprehensive Environmental Response, Compensation and Liability Act (CERCLA)., 42
, U.S.C. 9 9607(a). Several companies have been identified by U.S. EPA as potentially
responsible parties (PRPs) for the Site. The U.S. EPA is continuing to investigate additional
parties which may be liable for the cleanup costs at the Site. Table 2-2' lists the current PRPs
for the Site and the dates they were notified.
"
.' .'
The PRPs represent a combination of past and present property owners, .owners and operators
, of the various smelting, processing, and production facilities located within th.e' industrial
complex, and upstream mining companies responsible for discharges of mine a.nd mill tailings
into the' South Fork of the Coeur d' Alene River that have contributed' to the 'con~mlnatl<;m of ,
,the Site. ' ., ,
The current upstream mining companyPRPs include Asarco, Jnc., Hecia Mining Company,
(also named as a PRP on the basis of 50% ,interest in the Sullivan, Mining Company, which
owned and operated the zinc plant), Coeur d' Alene Mines Corporation and Callahan Mining
Company (which merged in 1991), Sunshine Mining Company and its 'wh()lly-owned 'subsidiary
Sunshine Precious Metals, Inc. (currently ili Chapter II Bankruptcy reorganization)" Silver
Bowl, Inc., and Highland Surprise Consolidated-Mining Company.
U.S. .EP A 'is also continuing to investigate a number of other mining companies which
previously conducted mining activities upstream of, or within, the Bunker Hill Site. In
addition to investigating the potential liability of these companies, U. S. EP A is investigating
the potential liability of other owners, operators and generators at the Site.
u.S. EPA has determined that selection or initiation of remedial action for the Site should not
be d.elayed pending an investigation of additional PRPs. '
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Table 2-2
Potentially Responsible Parties Identified for the
Bunker Hill Superfund Site
Name of Company . Notification Date
Gulf Resources and Chemical Corporation 10-18-84
Bunker Limited Partnership 10-18-88 and 1O-Q4-89
Minerals Corporation of Idaho 10-04-89
Bunker Hill Mining Company (U.S.), Inc. 1O-Q4-89
BH Properties, Inc. 1"0-04-89
Syringa Minerals Corporation 1O-Q4-89
Hecla Mining. Company 1O-Q4-89
Stauffer Chemical Company 10-04-89
ASARCO, Inc. 02-07-90
Callahan Mining Corporation '.. 02-o7~90 ..
. .
Highland Surprise Consolidated-Mining Company 02.,Q7-90
i S' I 02-07-90
I liver Bowl, Inc.
Sunshine Precious Metals, Inc. 02-07-90
Union Pacific Railroad 02-07-90
Coeur d' Alene Mines Corporation 02-07-90
Sunshine Mining Company 06-07-91
2.5 REMOVAL AND RESPONSE ACTIONS
The presence of elevated levels of metals, such as lead, zinc, cadmium, and arsenic in the soil,
ground water, and surface water, is a result of the historic mining, milling, and smelting
activities in the valley. In order to minimize or eliminate contaminant exposures and uptakes.
U.S. EPAhas developed and implemented several removal and emergency response actions for
the community within the Site. .
Pursuant to U.S. EPA's removal action authority under Sections 104 and I06(a) ofCERCLA.
42 U.S.c. ** 9604 and 9606(a), U.S. EPA has performed. required. and overse~n the
performance of five residential area removal actions. including removal of contaminate;;:: soils
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from residential yards and dust control in the residential areas of the Site. U.S. EPA also
issued two Administrative Orders, pursuant to Section 106(a) of CERCLA, 42 U.S. C. 9
9606(a), in 1989 and 1991; to several of the Bunker Hill PRPs{or performance of removal
activities at the Bunker Hill Complex. .
2.5.1 Residential Area Removal Actions
U.S. EPA performed two removal actions at the Site, in 1986 and 1989. In 1990, 1991, and
1992, the PRPs jointly funded additional residential area removal actions, with U.S. EPA and
IDHW performing oversight activities.
In 1986, 16 public properties (parks, playgroun~s, and road shoulders) were selected for an
immediate removal action because these properties contained high concentrations of lead and
were frequented by many area children. This action, conducted by U.S. EPA, consisted of
placing a barrier between children and the underlying .contaminated soil., Six inches of
contaminated materials were excavated, and clean soil, sod 'and/or. gravel were iniporteO for
replacement. Excavated material was temporarily stored within ,Site boundaries at property
owned by the Idaho Transportation Department (ITD).' . . ' .
In 1989, U.S~ EPAand IDHW conducted the first . residential soil. removal 'action at the 'Site,
beginning a program of four consecutive years of- residential soil removal actions performed '
during the summer months each year. The program prioritized yards that had a lead,
concentration greater than or equal to 1,000 ppm and housed 'either a young child or a
pregnant woman. This action consisle.d of removing 6 to ! 2 inches of contaminated material
from yards and replacing it with clean material. Contaminated soils were again stored at the'
ITD property within Site boundaries. 'In 1989, yard soil replacement was completed at 81 .
homes and 2 apartment complexes within the Populated Areas of the Site.' .
.In 1990, U.S. EPA began discussions with a number of the PRPs for continuation of the
residential soil removal program and related response actions. U.S. EPA requested that the
PRPs jointly fund and perform the removal aetioR under U.S. EPA and IDHW oversight.
.' Though negotiations continued for several months, no agreement was' reached. On May 15,
1990, U.S. EPA issued the PRPs an Administrative Order (U.S. EPA Docket No~ 1090-05-25- :
. 106), which ordered the PRPs to perform this work. U.S. EPA subsequ'entl.y negotiated an
Administrative Order on Consent (U.S. EPA Docket Number 1090-05-35-106) with eight of
the PRPs (Gulf Resources & Chemical Corporation, Hecla Mining Company, ASARCO, [nc:, ,
Stauffer Chemical Company, Callahan Mining Corporation, Coeur d' Alene Mines Corporation,
Sunshine Precious Metals, Inc., and Union Pacific Railroad) for payment of approximately
three million dollars to U.S EPA for performance of the 1990 residential soil removal action.
Yard soil removal and replacement for an additional 130 yards were performed in 1990.
Excavated soils from this removal action were stored'at the Page Ponds tailings impoundment.
In July of 1991, an Administrative Order on Consent (U.S. EPA Docket No. 1091-06-17-
106(a» was entered into between U.S. EPA and nine PRPs (Gulf Resources & Chemical
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Corporation, Hecla Mining Company, ASARCO, Inc., Stauffer Chemical Company, Callahan
Mining Corporation, Coeur d' Alene Mines Corporation, Sunshine Precious Metals, Inc."
Sunshine Mining Company, and Union Pacific Railroad) that required the PRPs to perform the
residential soil removal program. Approximately 100 yards were cleaned up under the Order
during the summer and fall of 1991, and the PRPs also agreed to undertake Site wide dust con-
trol actions; monitor air, ground water and surface water; enhance the fire fighting capability
at the industrial complex; and provide funding to purchase high-efficiency vacuums for loan as
part of the Health Intervention Program. As in 1990, excavated soils were stored at the Page
Ponds tailings impoundment. '
On July 29, 1992, U.S. EPA entered into a Administrative Order on Consent (U.S. EPA
Docket No. 1092-04-14-106) with the same nine PRPs, requiring these PRPs to perform the
fourth consecutive residential soil removal action at the Site. This Order also requires the
PRPs to remove and relocate contaminated soil tempOrarily stored on ITD property from
previous removal actions to the Page Pond Tailings impoundment, ,undertake dust cpntrol
activities, perform monitoring activities, provide up 'to $20,000.00 to fund' the Panhandle
Health District's lead intervention program, conduct repair work at properties cleaned up under
the July 1991 AOC, and provide disposal and transportation services (and replacement soil) for
contaminated soil excavated from residential and commercial properties within, the. Site.
2.5.2 Non-populated Area Response Actions
On October 24, 1989, U.S.EPA issued an Administrative Unilateral Otder (U.S. EPADocket
Number 1089-10-21-106) pursuant to CERCLA fi 106(a) against B.unker Limited Partnership,.
Minerals Corpordtion of Idaho, Bunker Hill Mining Co. (U.S.), Inc., and Gulf Resources. &
Chemical Corporation. U.S. EPA ordered these parties to immediately respond to releases and
threats of releases of h3zardoussubstances at the Bunker Hill Complex which the U.S. EPA '
determined were required to protect the public health or welfare or the environment, and to
address risks to the public health or welfare or environment which. the Agency for Toxic
Substances and Disease Registry had identified from its investigation of the Site. ' Actions
required by the Order included immediate cessation of salvaging activities onsite, establishment
of site access restrictions,' development of a dust control plan, and stabilization and.,
containment of the copper dross flue dust pile and other hazardous substances at the. Bunker' "
Hill Complex. '
On October 1, 1990,. U.S. EPA entered into an Administrative Order on Consent with Gulf
Resources & Chemical Corporation, and Hecla Mining Company (U.S. EPA Docket No.
1090-10-0 I-I 06) for the performance of hillside stabilization and revegetation work.' The
Order requires erosion control by reestablishing a native, coniferous forest and understory
vegetative cover to approximately 3,200 acres of barren hillsides and to perform terrace repair
and construction of detention basins, and repair of the eroding hillside areas in Wardner and
Smelterville.
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To control contaminated sediment transport from the hillside areas. and to facilitate
establishing vegetation, over forty miles of terraces have been constructed to date. A total of
one half million trees have been planted on barren hillside slopes during 199.1 and 1992.
Approximately 350,000 trees are scheduled to be planted in 1993~. . .
17,000 square yards of geotextile blankets have been installed along the Smelterville Slopes
and 6,000 square yards along the Wardner slopes. The blankets help stabilize the soil and
slows erosion. A number of large detention basins have. been constructed in Deadwood Gulch,
Magnet Gulch, Government Gulch, and the Page Mine area to control erosion and sediment
loadings from those areas to SFCDR.
Several abandoned mine dumps in the hillside area have been regraded and planted with
adapted vegetation. In June, 1992, work to recontour and revegetate the SiLver Bowl area was
completed. Approximately 40 acres of barren hillside were revegetated 'with grass, trees and
shrubs. Approximately 60% of the Page Mine Area was revegetated with grass and.
approximately 10,000 trees were 'planted. The remainder of the Page 'Mine area will' be
revegetated during the 1993 planting season.
To protect certain residential properties from erosion a 2,600 foot .rock-lined diversion channel
and 600 feet of sediment retention structures have been constructed in the Smelterville area..
Cribbing walls and other sediment retention structures.have also been installed in Wardner and'
Kellogg.
On September 27, 1991, U.S. EPA issued an Administrative Unilateral Order to the Bunker'
Limited Partnership, Minerals Corporation of Idaho, and Bunker Hill Mining Co. (U.S.),ln.c. .
(U.S. EPA Docket No. 1092-09-15-106) which directed immediate act~ons to cleanup and, .
prevent releases of hazardous substances at the Bunker Hill Complex, including the .topper .
dross flue dust pile, mercury sludge-and acid tanks, PCB-contaminated electrical transformers,
acid mine drainage, lead tailings and dust, and other waters continuing to be released. at .the .
complex. The Order also prohibits salvage activities, responsible for a serious fire on
September 23, L 991, which destroyed the mine rock house and concentrator conveyor system
and damaged other mine buildings. .
Work under this Order has proceeded with funding coming primarily from the bankruptcy
estates of the Bunker Limited Partnership (BLP) and Bunker Hill Mining (BHM)(U.S.). In
addition, certain portions of the work at the Bunker Hill Complex are being funded or
performed by Pintlar and Gulf. To date, approximately 935,500 pounds of mercury acid
sludge were removed from a large storage tank while about 360 drums' containillg such
materials were also removed and taken to a hazardous waste landfill in Arlington., Oregon.
Approximately 130 transformer carcasses that had been stored .in the phosphate plant were
recently taken to an approved facility for disposal. Transformers and electrical equipment
containing PCB oil were removed from the Bunker Hill mine in the spring of 1991, prior to
shut down and tlooding of the mine. The transformers were drained and properly disposed of..
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In addition, 40 drums of PCB oil stored in the compan¥ warehouse were removed ~nd
incinerated at an offsite facility.
Work to relocate 25,000 cubic yards of Copper Dross Flue Dust (CDFD) from Magnet Gulch
to an area in the Smelter Complex protected from runoff commenced in April 1992, and was
completed in June, 1992. The machine shop at the lead smelter was demolished and the
CDFD was moved to the machine shop's concrete pad. The CDFD contains about 40% lead,
11 % arsenic and 9% zinc, and will undergo further treatment and stabilization before final
disposal. Treatability studies are being performed on the CDFD in order to determine an
appropriate cement based stabilization mixture for treatment.
Following removal of the CDFD from Magnet Gulch, temporary pipes were installed on the
east side of Magnet Gulch to carry runoff from the A-I Gypsum Pond to a diversion ditch and
into Deadwood Gulch.
Actions taken to control contaminated windblown dust include thiny-six acres stabilized with .
rock surface armoring and 142 acres stabilized by chemical polymer sealing, including portions
of the CIA. Other areas have .received approximately 6 inches of organic amendments to .
promote revegetation efforts. .
2.5.3 U.S. EPA CERCLA Cost-Recovery and Enforcement Utigation
As discussed above, U.S. EPA has undertaken a variety of investigatory, response, and .
enforcement actions regarding the release of hazardous substances at the Bunker Hill.Superfund
Site.. Although certain response actions have been funded by the PRPs, U.S. EPA has
incurred approximately $21 million in response costs through August 1992. U.S. EPA has
rec~)Vert::d over $6.27 million from the PRPs as follows: ..$1.44 million from a 1989 Partial.
Consent Decr~ with G.ulf and from Gulfs repayment of over $1.65 million of U :5.. EP A's
RIfFS oversight costs. In addition, U.S. EPA received $3.18 million as a cashout payment.
from eight PRPs pursuant to the 1990 Administrative Order on Consent discussed previously.
In 1989, U.S. EPA recovered $1.44 million (included in the totals above) from Gulf for the
Agency's performance of the 1986 Fast Track removal action to remove and replace lead
contaminated soil from public playgrounds, road shoulders. and other public areas accessible. to
young children. These funds were recovered through a Partial Consent Decree entered on
DecemberS, 1989, in a cost recovery action filed in the United States District Court for the
District of Idaho. United States v. Gulf Resources & Chemical Corporation et aI., Civil No.
89-3067 (D. Idaho).
U.S. EPA al50 receives yearly oversight payments from Gulf under the 1987 Administrative
Order on Consent issued by U.S. EPA for performance of the remedial investigation and
feasibility study (RIIFS) for the Non-populated Areas of the Site. Through February 1992.
these payments have amounted to $1.65 million (included in the totals above). The Non-
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populated Areas RI/FS was completed in May 1992, and U.S. EPA issued the Proposed Plan
for remedial action of the Non-populated Areas on June 12, 1992. The Populated Area RI and
the Residential Soils FS were completed in 1991. U.S. EPA issued a ROD in August 1991
. which set forth the selected remedial action for cleanup of residential yard soils; at an
estimated cost of $40 million.
On July 2, 1990, the U.S. District Court in Idaho granted U.S. EPA's December 1988 petition
to unseal the court files in Yoss v. Bunker Hill Company et aI., Civ. No. 77-2030 (D. Idaho).
See In the Matter of a Petition by the United States of America to Unseal The File in Yoss v.
Bunker Hill Company et aI., Civ. No. 77-2030 (D. Idaho, Case No. MS-3505, July 2, 1990).
U.s. EPA subsequently copied and reviewed the files in this 1977 chiid lead poisoning case,
- which contain a variety of documents and materials pertaining to the September 1973 bag
house fire at the Bunker Hill lead smelter. U.S. EPA also subsequently obtained the parties'
trial exhibits from this case, discovery materials and other relevant .documents, which U.S.
EPA has used in developing a variety of reports and documents pertaining to the Site.
. .
From January to March, 1991, U.S. EPA filed liens on properties owned by BLP and MCI
within the Site, to help secure U.S. EP A's claims against these companies fOJ .past cleanup.
costs. The liens were filed. pursuant to Section 107(1) of CERCLA, 42 .V.S.C. ~ 9607(1):
On July 13, 1992, the U.S. Bankruptcy Court in Spokane entered an Order confirming the
Bunker Limited Partnership's (BLP) Chapter II Reorganization .Plan. In Re Bunker Limited
Partnership, No. 91-02087Kll (Spokane, Wa). The final Plim required BLP to deposit
additional funds (approximately $5 million) into its "EPA Remediation Account" .to bring the
tota! in the account to $7 million. In January 1992, the Bankruptcy. Court ord~red. BLP to
deposit $2 million into this account. These funds will be used by BLP .to perform cleanup.
activities pursuant to the September 27, 1991, Administrative Order issued by. U.S. EPA.
After payments to certain other creditors, BLP is required to deposit an .additional $6 million
into the account as part of-U.S. EPA's post-confirmation claim.
The Chapter 11 Reorganization Plan also requires BLP .to liquidate its remaining assets,.
inCluding 3,700 acres of timberland not yet sold, 9,500 acres of land in and around Kellogg,. .
Idaho; 6,000 acres of which are within the Site, and .upon which U.S. EPA previously filed
liens. From the proceeds of these future sales, BLP is required to deposit $6 million into the.
U.S. EPA Remediation Account (in addition to the $7 million) to be used to perform response
actions at the Site. To the extent the liquidation of BLP's estate generates additional funds,
there will be a pro rata distribution to the unsecured creditors, of which U.S. EP A is the
largest creditor ($100 million Allowed Unsecured Claim).
U.S. EPA is currently overseeing BlP's cleanup activities pursuant to the September 27, 1991,
Administrative Order. Several million dollars have been spent since January 1992 from BLP's
U.S. EPA Remediation Account. As described in Section 2.5.2 above, these funds have been
used for relocation of a large copper dross tlue dust pile in Magnet Gulch. removal of mercury
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sludge barrels, treatment of acid mine drainage, disposal of acid wastes and contaminated
equipment at the Bunker Hill complex, and dust suppression work.
U.S. EPA also issued the September 1991 Section 106 Order to the Bunker Hill Mining
Company (U.S.), Inc. (BHMC), owner and operator of the Bunker Hill and Crescent Mines.
After BHMC declared bankruptcy, U.S. EPA negotiated the removal of PCB transformers
from the mine before it flooded when power to the dewatering pumps was turned off.
BHMC's Liquidation Plan was confirmed by the Idaho Federal District Bankruptcy Coun in
August 1991. Bunker Hill Minim! Company (U.S.). Inc., (Chapter 11 Bankruptcy, Civ. No.
91-00 161, Coeur d' Alene, Idaho).
BHMC's Liquidation Plan provides that, after payment of taxes, all proceeds will go as an
administrative expense toward response actions performed by U.S. EPA for the Site. Although
there are few valuable assets in BHMC's banlauptcy estate, U.S. EPA is continuing to receive
a portion of the proceeds from the sale ofBHMC's property. BHMChas thus far generated
over $100,000 from the sale of assets that will be used to fund U.S. EPA cleanup activities at
the mine complex. Additional funds wi1l be generated as BHMC continues to sell its assets.
As a result of several recent sales, including ,the sale of the' mine portal. rock house; and ore
concentrator, BHMC is funding the disposal of PCB oil and equipment and dust control
activities. '
. , .
Sunshine Precious Metals, Inc. (SPMI), also filed for bankruptcy. protection .00 March 20,
1992. SPMl, one of the PRPs for the Site, is currently in Chapter 1'1 Bankruptcy an9 is
seeking confirmation of its Reorganization Plan. This Pian" as currentiy drafted for court
approval, provides that U.S. BPA's claim will not be discharged. Although SPMI disputes'
U.S. EPA's claim" it has agreed that U.S. EPA's claim will not be impaired and will survive,
confirmation with whatever rights existed prior to March 20., 1992. This will enable U.S. '
EPA to reach a settlement with SPMI regarding its liability for the Site, or if necessary.
litigate such claims in coun.
U.S. EPA will continue to oversee BLP's and BHMC's cleanup activities with funds obtained '
pursuant to the two final Bankruptcy Plans. U.S. EPA is continuing to closely monitor the
various bankruptcy proceedings and prepare for other necessary enforcement' actions at the
Site, including consent decree settlement negotiations with the PRPs for the performance of
remedial actions and reimbursement of past and future costs incurred by U.S. EPA. '
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3 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The specific requirements for public participation at the Site include releasing theRIIFS and'
Proposed Plan to the public. This was done on June 15, 1992. Both documents were placed'
in the Administrative Record and information repositories. NotiCes of the availability of these'
documents, a public meeting on the Proposed Plan and a public comment period was published
in the Spokesman-Review and Shoshone News Press on June 13, 1992; reminders of the
public meeting were placed in the Shoshone News Press on June 20, 21,23, 24, and 25, 1992.
The initial public comment period was from June 15 to July 15, 1992; it was extended to
August 14, 1992 after a July 10 citizen request to extend the com mer.! period was received. A
-public meeting was held on June 25, 1992. Comments from the public were taken and are
summarized in the Responsiveness Summary portion of this document along with all written
comments that were submitted during the ,comment 'period. '
There has been a long history of community relations activities in the Silver Valley. 'Since
discovery of elevated blood leads in children in 1974, the IOHW, Panhandle Health District,
(PHO), and the COC have continually worked with area residents to reduce exposures, to lead.
I,n 1985 the Shoshone County Commissioners selected a' nine member Task Force to serve as
a citizen's advisory group to the, Bunker Hill' Superfund Project Team (comprised of
representatives of U.S. EPA and IDHW and contractors). The PHD was contracted by IDHW ,:
to perform community relations tasks for the Site. A ,full time IDHW staff person has also
been stationed onsite from mid 1987 to present. ' Part of the Task Force's duties is tcr assi:st. in
community relation activities when needed.
Community relations activities have focussed on maintaining effecti~e communication between
the citizens living on the Site and the agencies. Actions taken have been' tailored to ~t
community needs and are consistent with the, requirements of the' federal 'law.' They have
provided an ongoing forum for citizen involvement in reaching the remedial action decisions
prescribed in this ROD. '
Between May 1985, and July 1991, the following meetings and community outreach activities
were cond uded:
Description
Count
Task Force Meetings
37
Meetings with Groupsl
Civic Organizations
79
Meetings with Fair SharelICN
18
Fact Sheets
25
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Health Intervention Program
Screenings
9
Information repositories have been created for the public to have access to minutes of task
force meetings, all major project documents, fact sheets, orders, and other peninent
information. These repositories are located at the Kellogg Public Library, Ketlogg City HaIl,
Pinehurst/Kingston Public Library, and Smelterville City Hall.
Generally, meetings were well attended. Task force meetings typically were composed of 20 -
50 community members. Proposed plan meetings were attended by over 150 citizens. Smaller
group meetings were intended to get information to interested groups.
Specific Community Relations Activities at the Site are listed below. For those activities prior
to May 1991 , only the dales have been listed. For further details on th~se acti vi ties, refer to
the Record of Decision on the Residential Soils (August 1991). -,
July 15,
16, 17, 1992
Notice ran in the Shoshone News Press "
announcing the extension of the Public Comment Period.,
July 10, 1992
U.S. EPA released a Public Comment Period extension notice. to
people on the .mailing list. .
June 25, 1992
U.S.EPA conducted the Proposed Plan Pul>lic Meeting
June 20, 21, 23,
24,.25, 1992
A reminder of the public- meeting ran
in the Shoshone News Press.
June 13, 1992
Ad ran in the Shoshone News Press and the Spokesman Review,
announcing the date and time of the public meeting and the public.
comment dates. The ad also briefly described the preferred
alternative and encouraged comments on all alternatives from the
proposed plan. Also explained where people could pick up copies
of the entire plan.
June 13, 1992
The Agencies distributed the. Proposed Plan fact sheet door to
door in Smelterville, Wardner, Kellogg, Pinehurst, and the rest of
the Superfund Site.
June 13, 1992
U.S. EPA mailed the Proposed Plan [0 the mail list and provided
additional copies to the following locations: Superfund Project
Office, Kellogg Library, P:anhandle Health District Office,
Pinehurst/Kingston Library, Kellogg City Hall, and Smelterville
City Hall.
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June 4, 1992
May 28, 1992
May 1992
April 30, 1992
March 19, 1992
February 26, 1992
September 5, 1991 '
August 12, ,1991
May 23, 1991
April 26, 1991
February '28, 1991
February 21, 1991
January 18, 1991
October 25, 1990
October 2, 1990
Regional Administrator and other representatives of U.S. EPA
met with several community .groups including the Task Force and
the Kellogg Chamber of Commerce.
Task Force Meeting to discuss institutional control and interior
dust remediation alternatives.
Newspaper article ran in the Silver Valley Voice, which explained
in detail the alternatives that were being considered for the Site.
.
Task Force Mce~ing to discuss the cleanup alternatives proposed
for ground water and surface water.
Task Force Meeting to discuss CIA, smelter complex, MOA and
Smelterville Fiats cleanup alternatives.
Door to door distribution by the Agencies of a fact sheet, which
outlined the project accOmplishments from 1991' and announced
the activities expected to Occur over the spring and summer arid'
project accomplishments that had taken place in 1991. ' '
Door. to door distribution by the agencies of a Fact Sheet
, announcing the cleanup plan for Residential Soils.
Door to door distribution by the Agencies of an updated Fact'
Sheet on the H iIlsides Project.
Proposed Plan Public Meeting on Residential Soils Cleanup
The Proposed Plan for Cleanup of the Residential Soils Within
the Site
Door to door distribution by the agencies of a Fact Sheet Update.
Task Force Public Meeting.
Fact Sheet explaining the 1990 accomplishments.
Task Force Public Meeting and Summary of Findings Risk
Assessment/Data Evaluation Report (RADER) Populated Areas.
Fact Sheet released by U.S. EPA which discussed the Hillside
Stabilization and Revegetation Order.
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September 1990
July 24, 1990
July 19, 1990
April 12, 1990
March 19, 1990
February 26, 1990
December 1989
November 16, 1989
September 1989
August 24, 1989
May 18, 1989
March 1989
February 16, 1989
December 15, 1988
October 19, 1988
September 8, 1988
September 1988
July 28, 1988
July 1988
June 30, 1988 .
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u.S. EP A released a fact sheet which explained the CERCLA
Process at Bunker Hill.
u.S. EPA released a general update on activities at the Site.
Task Force Public Meeting.
Task Force Public Meeting.
u.S. EPA released a fact sheet update on the proposed Page Pond
disposal
Bunker Hill Superfund Site Fact Sheet
Bunker Hill SUp'erfund Site Fact Sheet
Task Force Public Meeting.
Bunker Hill 1989 Residential Soil Removal Action Cost Summary
through 9/29/89 .
Task Force Public Meeting.
Task F,?rce Public Meeting.
Panhandle Health District I:. Notice .of Engineering Evaluation
for Phased Clean-up commem.
Task Force Public Meeting.
Task Force Public Meeting. .
Task Force Public Meeting.
Task Force Public Meeting.
Bunker Hill Superfund Fact Sheet
Task Force Public Meeting.
Bunker Hill Superfund Project Update
Task Force Public Meeting.
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May 12, 1988
February 26, 1988
December 10, 1987
December 1987
August 13, 1987
August 11, 1987
June 1987
June 18, 1987
May 1987
April 16, 1987
March 9, 1987
March 1987
February 5, 1987
January 1987
Qecember 11, 1986
September 18, 1986
August 7, 1986.
July 1986
May 29, 1986
April 10. 1986
March 20, 1986
Task Force Public Meeting.
Letter to Silver Valley Task Force chairman concerning how U.S.
and IDHW will proceed with the RIIFS process.
Task Force Public Meeting.
Bunker Hill Superfund Project Update.
Task Force Public Meeting.
Letter to Interested Parties regarding RIIFS
Superfund Site
Bunker HilI
Memo to Silver Valley Bunker HilI Superfund Task Force
Task Force Public Meeting.
Status Report: Bunker Hill Superfund Project
Task Force Public Meeting.
. Task Force Public Meeting.
Bunker Hill Superfund Site Update
Task Force Public Meeting:
U.S. EPA released a fact sheet explaining the Superfund Process.
Task Force Public Meeting.
Task Force Public Meeting.
Task Force Public Meeting.
Memo to Silver Valley Superfund Task Force regarding Silver
Valley Superfund Project
Task Force Public Meeting.
Task Force Public Meeting.
Task Force Public Meeting.
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February 13, 1986 Task Force Public Meeting.
January 9, 1986 Task Force Public Meeting.
December 5,1985 Task Force Public Meeting.
October 24, 1985 Task Force Public Meeting.
September 19, 1985 Task Force Public Meeting.
August I. 1985 Task Force Public Meeting.
June 27, 1985 Task Force Public Meeting.
May 16, 1985 Task Force Public Meeting.
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4 SCOPE AND ROLE OF OPERABLE UNIT
The rationale for separating the Bunker Hill RifFS into two parts involved data availability and
confidentiality issues associated with investigation of private residential properties within the
Populated Areas. Both environmental and human health related data were collected as part of
the epidemiological studies. Because of this the agencies believed that the Populated Areas
RIIFS could best be completed by the agencies in order to honor confidentiality agreements
with individuals and individual property owners.
The residential soH component of the Populated Areas was the first operable unit to be
addressed in a ROD (August 1989). The other components related to the Populated Areas
investigation that have not been addressed in a decision document include: residential
interiors, commercial properties, and rights-of-way. The agencies originally expected to
address these issues in a second ROD in 1992; however, the Potentially Responsible Parties
(PRPs) proposed to the U.S. EPA and IDHW a Site Wide cleanup plan that comprehensively
addresses concerns in both the Populated and Non-populated Areas. Subsequently, the
Agencies decided to complete the Residential Soils ROD as scheduled, because soils are a
primary risk to the' residents;, however, all remaining issues (see Table 2-1) were consolidated
into a comprehensive FS performed by the PRPs with U:S. EPA oversight representing a
second Operable Unit for the Site. That FS supports this second ROD for the Site.
Elements addressed in this ROD include:
. Hillsides
. Smelterville Flats
. Central Impoundment Area
. Page Pond
. Smelter Complex and Mine Operations Area
. Rights-of-Way .
. Commercial J3uildings and Lots
. Residential Interiors
. Future Development in Non-populated Areas
. Constructed Wetland Treatment Systems
. Public Water Supply Considerations
. Soil Action Levels
. Institutional Controls
. Monitoring
. Operations and Maintenance
The consolidation of these elements for investigative and remedy selection purposes recognizes
the interrelationships among the geographic areas of the Site, transport media considerations,
and the need to develop an integrated remedial action for the Site. Throughout the FS process,
every effort was made to consider how remedial actions' for each area would impact an overall
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remedial action for the Site. Development of the FS by the cooperating PRPs involved
considerable dialogue with the agencies. Numerous meetings were held to focus technical
evaluations of site contamination and evaluate cleanup options.
This ROD considers both the interrelated nature of the various Non-populated Areas, and .the
need to integrate residential areas into a site wide remedial action. For example the decision
in the Residential Soils ROD to utilize removal and replacement of contaminated residential
soils to a depth of one foot has impacts on site ground water that must be considered in
evaluating that resource in subsequent investigations. The residential soils ROD also sets the
stage for the utilization of institutional controls as a component of site wide remedial actions
and appropriare remedies for onsite disposal of contaminated residential soils. Actions selected
in this ROD complement the remedial actions selected in the Residential Soils ROD. Together
this ROD and the Residential Soils ROD serve to prescribe a protective site wide remedy for
the Bunker Hill Site. Studies conducted during the Residential Soils RIlFS, including the
RADER, were factored into the decisions in this ROD. Response actions required by the
existing U.S. EPA Orders for the Site are components of this ROD .and are hereby
incorporated into this ROD. .
Actions selected in this Record of Decision do not address sources of contamination upgradient
of the Bunker Hill Superfund Site, and while onsite actions. are expected to: have significant.
benefits to downgradient SFCDR water quality conditions over time, active remediation of the .
SFCDR is beyond the scope of actions specified in this ROD. The NCP gives U.S. EPA
broad discretion to use not only CERCLA but. also other appropriate" authorities, to address
releases of hazardous substances in the Coeur d'Alene Basin. Recently U.S. EPA, the State of
Idaho, the Coeur d' Alene Tribe of Idaho and other federal, state and local agencies have.
initiated efforts to integrate water quality improvement programs in the Coeur d' Alene Basin.
The Coeur d' Alene Basin Restoration .Project efforts are expected to complement- actions-- -
selected in this ROD in improving overall water quality conditions in the Basin. The Coeur
d' Alene Basin Project is being designed to integrate and coordinate the activities within the
Coeur d' Alene Basin which are being undertaken by the local landowners, local governments,
state agencies;. the Coeur d' Alene Tribe, the Federal Trustees and U.S. EP A. This includes
coordination of regulatory authorities under the Clean Water Act (CW A), CERCLA, and
RCRA. Other state, local and Tribal programs will also be integrated into this Project. The
Clean Water Act provides a mechanism for developing water quality standards, evaluating
discharge permits and establishing nonpoint source controls within the Coeur d' Alene Basin. .
CERCLA provides a mechanism for investigation and controlling the release of hazardous
substances through the exercise of removal authorities.
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5 SITE CHARACTERISTICS
5.1 PHYSICAL SETTING
The Bunker Hill Superfund Site consists of a seven-mile by three-mile section of the east-to-
west trending valley of the South Fork of the Coeur d'Alene River (SFCDR). The topography
of the valley, known as the Silver Valley, consists of an alluvial floodplain bordered on the
north and south by steep mountains or hillsides. Floodplain width varies from about 0.1 mile
east of Kellogg to approximately 0.9 miles near Smelterville. The elevation of the valley floor
ranges from 2, 160 f~t above mean sea level at the west end of the Site to 2,320 feet at the
eastern end of the Site. Typically, the valley floor is nearly level, with most slopes less than
one percent. Mountains rising from the valley range from 500 to 2,500 feet above the valley
floor. The mountainsides typically exhibit slopes of 45 to 90 percent and at some points
exceed 110 percent. Numerous valleys and gulches cut through the mountains and generally
trend north to south, intercepting the valley of the South Fork Coeur d' Alene River (SFCDR):
The major drainages of the Site are on the south side of the Valley. These include Milo,'
Deadwood, and Government Gulches.
SOILS
Soils within the Site vary from poorly developed native colluvium and slope-wash materials on
the hillsides to largely alluvial soils on the SFCDR vaHey floer. .
Hiilside area soils with slopes greater than 35 percent were generally formed in volcanic ash
and metasedimentary rocks. Surface layers are typically 14 to 16 inches of gravelly silt loam
with very cobbly loam .subsoils extending more than 60 inches to weathered bedrock. In the
Smelter Complex area, terrace deposits occur near the base of the hillsides and are formed in
glacial and alluvial deposits. Thesesoils typically have exposed subsoils consisting of silt loam
and heavy silt loam underlain by very cobbly or very gravelly heavy silt loam and silty clay
loam. . .
Hillsides in the immediate vicinity of the Smelter Complex are generally devoid of vegetation,
resulting in conditions favorable to sheet, rill, and gully erosion. This erosion has resulted in
substantial loss of material from the upper soil horizons.
Soils and surface materials on the SFCDR valley floor (including Smelterville Flats) v.ary in
their physical characteristics and genesis from those on the hillsides. with some evidence of
regional loess contribution.. The valley floor soils and surface materials were impacted by the
construction of a plank and pile dam at the west end of Smelterville Flats in the early 19lOs
which retained sedimentS, including tailings, until its failure in the 1930's. The tailings have
been reworked and redistributed by the river since that time. Flooding of ihe SFCDR together
with excavation of the tailings/alluvial mixture (jig tailings) for reprocessing has redistributed
jig tailings and smelter emissions throughout most of the valley flood plain.
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SURFACE WATER
The SFCDR below Wallace, located 12 miles east of Kellogg, is a relatively shallow stream
with a gradient of about 30 feet per mile. Since mining activities in the area began, the
SFCDR and some tributary streams in"theSite vicinity or the Site, as well as upstream, and
downstream areas, have received .a sediment load which included mine/mill tailings.
Flow variations of the SFCDR are affected by spring snowpack melt. In a typical year, peak
average monthly flows occur in April, May, and June, tapering off in later summer and early
fall. In winter, flows are low unless an early snow melt or a large rainfall event occurs.
The drainage network of the Coeur d' Alene River (CDR) Basin includes Canyon Creek, above
Wallace; Big Creek (including its east and west forks), between Osburn and Kellogg;
Montgomery Creek; and, Pine Creek (including its east, middle, and west forks); near
Pinehurst. There has been extensive mining activity in many of the tributaries upstream ofthe
Site, in particular Canyon Creek, Nine Mile Gulch, and Big Creek. Tributaries within the
Superfund Site include Milo, Italian, Jackass, Portal, Deadwood, Magnet, Government,
Humboldt, Grouse, and Pine Creek Gulches. .
GROUND WATER
Water bearing materials in the Site include: . upper, confining, and lower zones. This system
is important . because of its hydraulic linkage with the SFCDR. relatively large ground wate;.
discharge rates and flow velocities, and potential to receive- contaminants from overlying and'
integrated sources as well as upstream areas. Ground water' is also known to be present, at
least seasonally, in colluv.ial/alluvial deposits in tributary valleys and locally in .terrace deposits
along the south wall of the SFCDR Valley. Ground water sysiems are probably present in the
hillsides along the bedrock/soil interface, particularly after precipitation and snow melt events.
It is probable that a fracture-flow. dominated ground water system exists within the bedrock
underlying the Site (RI, 1992).
Major tributary valleys at the 'Site include Milo, Jackass, Italian,. Deadwood, Magnet,
Government, Grouse, Humboldt, and Pine Creek Gulches. Ground water in these gulches
probably occurs in shallow, unconfined systems with steep hydraulic gradients; an exception to
this is the Pine Creek drainage, which is relatively large with a flat floor. Potential recharge
sources to these ground water systems include infiltration of precipitation and snow melt,
leakage from streams, leakage from surface impoundments, and potential contribution from.
'bedrock sources, Discharge from the tributary gulch ground water systems primarily enters.
the upper zone of the valley fill aquifer system.
From an environmental impact perspective, Government Gulch is one of the more important
tributaries entering the SFCDR Valley because of numerous contaminant sources. resulting
from the Zinc and Phosphoric Acid Plants, Water levels in Government Gulch are typically
highest in April and lowest in January and October. Although water levels varied by as much
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as seven feet, the horizontal hydraulic gradient tends to be relatively constant, indicating that
water level fluctuations are fairly uniform within the Gulch. Relatively constant ground water
flow gradients are expected in other tributary gulches. The estimated ground water gradient in
Government Gulch is about nine times that noted in the upper zone of the SFCDR Valley.
VEGETATION
Forests in the Bunker Hill Superfund Site area are characteristic of the northern region of the
Rocky Mountains, extending from southern Montana and Idaho to Jasper. National Park in
Alberta. Typical forest area species in the Site area include: western hemlock, western red
cedar, mountain hemlock, and subalpine larch which arc interspersed among ponderosa pine,
lodgepole pine, douglas-fir, and subalpine fir.
Much of the Site vegetation has been modified by past disturbances and, consequently, forests
on the Site are typically restricted to the upper elevations of the hillsides and areas near the
perimeter of the Site (Pinehurst, Elizabeth Park, etc.). In general, vegetative cover increases
with increasing distance from the Smelter Complex. The present site area includes barren
areas (near the Smelter Complex), sparsely vegetated shrub land (peripheral to barren areas),
natural forested areas (upper hillsides near the boundaries), swamps (southwestern portion of
SmelterviHe Flats), plantations of young conifers (areas planted by the -Bunker Hill Company),
and urban vegetation (residential areas).
CUMA TJ;
The meteorology of the Site is dominated by mountain/valley drainage winds related to the
local topography. Wind patterns in the SFCDR Valley generally follow.a daily recurring.
upvalley/downvalley (easterly/westerly) flow regime. Typically, night cooling of the ground
layer leads to a surface-based atmospheric temperature inver.sion, producing a down-valley
flow of air. After sunrise, heating of the valley floor and hillsides causes a reversal of the
earlier wind pattern,. although not as strong. During the transition period between the two
wind directions, winds are generally calm in the valley. At other ~imes, because of the
. sheltering effects of the SFCDR Valley location, wind speeds are typically lower in the va11ey
than more exposed areas such as hillsides. Construction. of a wind frequency
distribution/magnitude plot shows the influence of strong regional west to east winds (see
Figure 3-31 of RI, Volume 1).
The Bunker Hill Site receives some of the highest levels of precipitation in Idaho. Normal
annual precipitation in the SFCDR valley floor area (Kellogg) is approximately 30.4 inches.
Total annual precipitation at Kellogg typically has a relatively small range of 20 to 40 inches,
with extremes of 47.6 inches in water year 1974 to 17.4 inches in water year 1973. Mean
annual snowfall for the period of record in Kellogg was 69.9 inches. Average annual
precipitation at higher hillside elevations can exceed 50 inches (RI, 1992). An average of 70
percent of the annual precipitation at Kellogg occurs from October to April, mainly as
snowfall.
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At higher elevations, snow normally persists from late fall to late spring. The Bunker Hill Site.
. area is positioned to receive straight zonal flow of warm Pacific. moisture from. the west.
Resulting precipitation from this system in combination with a melting snowpack have
produced some of the largest floods in the SFCDR Basin; these have occurred during the
winter months. .
The Bunker Hill Site is in the climate region termed "highland climates", and is dominated by
mountain-valley climate characteristics such as upvalley/downvalley wind regimes. This is
accompanied by considerable variation in snowfall with elevation and location. The mean
annual temperature for the period 1951 to 1980 was 47.2°F. The record extreme temperatures
were 1lioF (August 5, 1961) and -36"F (December 30, 1968). On the average, 28 days per
year reach a maximum temperature of 900F or greater, and 143 days reach a minimum of 32°F
or lower (RI, 1992).
CULTURAL SETTING
The Bunker Hill Superfund Site encompasses four incorporated cities (Kellogg, Pinehurst,
Smelterville, and Wardner) and three communities (Elizabeth Park, Page. and Ross' .Ranch). .
About 5,000 .residents live within the Site. Settlement of the valley was associated with the
development and growth of the metal mining and smelting industries.. Homes and .business
were constructed throughout the valley floor and side gulches. As a result, local populations
live to varying degrees in close proximity to contaminated media and sometimes contaminant
sources. For example, many valley floor residences have been constructed on tailings,
resulting in contaminated yard soil. Smelter emissions also ca:lse.d widespread contaminant
dispersion, resulting in contaminated yard soils and interior dusts. . The pervasive nature. of.
Site contamination and the close association of the resident population requires remedial actions
that retain the integrity of the residential community while addressing contaminant exposure
pathways.
5.2 NATURE AND EXTENT OF CONTAMINATION
5.2.1 Contaminants of Concern
Adverse environmental impacts have and continue to occur from heavy metals and other
contaminants associated. with mining, milling, and mineral beneficiation and processing.
activities. The Site Characterization Report (SCR) listed thirteen contaminants of concern
based on preliminary investigations including the following:
. Antimony
. Arsenic
. Beryllium
. Cadmium
. Cobalt
. Mercury
. Selenium
. Silver
. Zinc
. Asbestos
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. Copper
. Lead
. Polychlorinated Biphenyls
(PCBs)
. Work conducted subsequent to the SCR and as proposed by the Non~populated . RIfFS Work
Plan addressed these principal contaminants along with an extensive screening program for the
presence of other 'conta'minants of concern, including organic compounds. Task 0 of the RI .
sampled for the priority pollutant list and 10 other constituents. Task 0 activities entailed
collection of solid and liquid samples for broad-spectrum contaminant screening at the onset of
the RI. Evaluation of the analytical results was completed in conjunction with a review of
field records, historical records, and process, product, and by-product material information.
During the RI, no additional contaminants of concern were identified. Manganese is listed as
a contaminant of concern in the Ecological Risk Assessment (ERA) because of the potential
impact to small mammals from localized soils; additionally, manganese was identified in the.
Risk Assessment Data Evaluation Report (RADER) as exceeding Secondary Drinking Water
Stand~rds (DWS) in some instances. Some contaminants of concern were not detected in
. surface or ground water during the screening process and thus were eliminated from further
water analyses. Beryllium, PCBs, and asbestos analyses were .not routinely conducted on
surface or ground water samples," and antimony and copper analyses were not routinely
conducted on ground water samples since screening determined these constituents to be below.
levels of concern.
5.2.2 Contaminant Sources
The presence of contaminants at the Site was traced to the following contaminant s9urces and' .
. source areas identitied during the RJ:
~ Ji~ Tailings - In the early years of operation, mills within the Site and,. for a longer
period, mills upstream of the Site, released tailings, a waste product from the ore .'
concentrating process, which were deposited on the vall~y floor. During flood events,
these tailings were transported by the SFCDR, mixed with alluvium, and deposited on.
the flood plain. The valley floor throughout the Site is currently mantled with a mixture.
of jig tailings, flotation tailings, and alluvium, as well as air dispersed contaminants from'
the Smelter Complex. The mixture is referred to as "jig .tailings" for the purpose of the
RI/FS. Jig tailings were identified as a source of Site wide metals contamination in soil,
air, surface water, and ground water. .
. Flotation Tai]iO!~s - Crude flotation ore concentration methods were used at the Site as
early as 1913. Froth flotation was the predominant method of ore concentration after
approximately 1930. The byproducts of this ore concentration prQcess are called
flotation tailings. The. release of tailings fr<;>m the. Page Mi"ll to the Page tailings
impoundment began in 1926. Flotation tailings for the Bunker Hill Mill were deposited
on the valley tloor until the West Mill began discharging to the Central Impoundment
Area (CIA) in 1928. Uncontrolled releases of tlotation tailings in upstream areas
continued until as late as 1968; these tailings comprise a portion of the alluvium/tailings
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mixture (jig tailings) on the SFCDR Valley floor. Flotation tailings impounded in the
CIA and Page Pond were recognized as sources of metals contamination in air, surface
water, and ground water.
. Inflow of Contaminants at the Upstream Site Boundary :.. Mining and milling operations
were conducted upstream of the eastern site boundary during the same period as those'
conducted within the Site. The Rl documented the degradation of surface and ground
water quality upgradient of the Site, and identified the influxes of metals in surface and
ground water at the eastern Site boundary as sources of contamination within the Site.
. Air Emissions - The Lead Smelter began operations in 1917, and Zinc Plant productiQn
began in 1928. Particulate controls were employed to capture and recycle the Lead
Smelter and Zinc Plant flue dusts, but sulfur dioxide emissions were not directly
addressed until sulfuric acid. plants were constructed in 1954 and 1965 (Zinc Plant) and
1970 (Lead Smelter). Emission controls were not consistently effective, and operational
. upsets occurred, in particular aiterthe 1973 baghouse fire. Smelter Complex air
emissions, including fugitive emissions;" were identifi~ as sources of lowered pH and
heavy-:metal concentrations in soils throughout the Site, anQ contributed to vegetation
damage and erosion on hillside slopes..
. Smelter Complex Materials' and Residuals - Ores, concentrates, flue dusts, sinter and'
calcine (products of roasting concentrates), lead residues, slag, gypsum, other materials,
and wastes were stored, transported, and occasionally"spilled in and around the Smelter'
Complex. Material accumulations and residual materials within the complex were
identified as sources of air, surface water, and ground water contamination. The Smelter
Complex had the highest concentrations of contaminants of any area within the Site.
. Gypsum and Slag - Gypsum generated during phosphoric acid production wa.s disposed in
three impoundments that were identified as sources of blowing dusts and inorganic non-
metal contaminants in surface and ground water. Large quantities of granulated slag
were deposited i~ the CIA west cell.. The granulated slag was produced by the zinc
fuming process wherein most of the zinc was removed as zinc oxide. Small quantities Of
ungranulated slag were deposited adjacent to the lead smelter. The ungranulated slag
was not subjected to the zinc fuming process and therefore contains a greater abundance
of zinc than the granulated slag. The remaining metals in the granulated and
. ungranulated slag are relatively immobile in their current state due to "their incorporation
in a silicate matrix.
. Acid Mine Drainage - Dewatering of the Bunker Hill Mine has contributed acidic,
metals-laden mine water to the east cell of the CIA. Most. dewatering was curtailed in
early 1991; however, it is likely that full scale dewatering will resume in the future.
Seepage from the east cell was idemitied as the largest source of metals loading to Site
ground water during the RI. .
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Full-scale smelting operations at the Site ceased in 1981, although salvage'efforts, including
sporadic open-pot smelting, were reported in the mid-1980s. Mining and milling operations
have operated at the Site intermittently since 1981, but were curtailed in early. 1991.
Therefore, new contaminants are no longer being generated onsite with the exception of
continued mine discharge. However, contaminants continue to enter.ground.watet and surface
water at the upstream Site boundary. Additional contaminants will be generated onsite and
will increase if dewatering of the Bunker Hill Mirie is resumed or when water flows naturally
from the mine. The redistribution of contaminants from existing sources by air, surface water,
ground water and anthropogenic activities continues to impact onsite and offsite areas.
A description of the nature and extent of contamination by media and current contaminant
transport pathwa}s as characterized during the RI are provided in the following sections.
SOILe:; AND SURFICIAL MATERIALS
Soil contamination exists in most areas'of the Site. Contaminant concentrations in Site soils
are generally highest in and adjacent to the Smelter Complex. Table 5-1 summarizes
maximum soil metals concentrations exhibited within the Bunker Hill Superfund Site. Soil
. metals concentrations were compared .with background 'Ievels established for the .Coeur.' d' Alene'
Mining District by the U.S. Geological Survey (Gott and Cath~ll, 1980). "Threshold levels"
were established as a basis for locating ore deposits.
HILLSIDES .
Metal concentrations in undisturbed hillside soiis throughout the Site were generally elevated
above the threshold levels. The highest metals concentrations in the hillside soils occurred in
the uppermost few inches of soil profile; metais concentrations generally.decreased sharply
with depth. Table 5-2 summarizes average metal concentrations for ~l1zones ~t 0-1" depth in
the Hillsides and the vicinity around the Smelter Complex area. Sources of hillside soil
contaminants included historical Lead Smelter and Zinc Plant air emissions, wind-mobilization
and subsequent deposition of fugitive dust from material accumulations and. residuals. in' tHe
Smelter Complex, and deposition of wind-blown tailings. Erosion of contaminated soils was
identified as a contaminant transport mechanism during the RI and has resl1lted in a reduction
of surface .soil concentrations in some areas.
SMEL TERVILLE FLATS
Jig tailings were widely distributed on the valley floor throughout the Site; these deposits
contain elevated metals concentrations compared to threshold levels. The largest accumulation
of jig tailings within the project area is on Smelterville Flats, where contamination ranges to
depths of three to seven feet, with local accumulations approaching ten feet in thickness. Jig
tailings also underlie the CIA and portions of the Page Swamps. In general, concentrations in .
the jig tailings are dependent on the relative quantities of tailings and alluvium in the mixture.
Maximum concentrations of 504 mg/kg arsenic, 78.2 mg/kg cadmium, 30.000 mg/kg lead. arid
15,600 mg/kg zinc were measured in valley floor jig tailings samples.
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Areas Arsenic Cadmium Lead Zinc
Hillsides. 300 245 14,400 16,100
Smelterville Flats 504 78.2 30,000 15,600
CIAb 692 51.8 7,760 23,600
Pag~t 202 38.7 4,350 4,260
Smelter Complexd 160,000 127,000 860,000 754,000
MOA 44,300 3,630 651,000 170,000
Background. -< 10 0.8 43 9$
a -includes areas around the Smelter Complex.
b includes the CIA East. Middle. and, West cells.
c average concentra,tions. - -
d . includes Lead Smeller area. Mag:'!el GlIh.:h/Dcadwood Galel: arcn~-. Phosphun.: A;:llIiFerlilizer Pj~n! arc...".
and Zinc Plan! area. - -
e S9urcc: Gott and Cathrall. 1980.
Table 5-2
Soil Average Concentrations (mg/kg) for All Zones at 0-1'" Depth
ARSENIC CADMIUM LEAD ZINC
AREAS
AVE. RANGE AVE. RANGE AVE. RANGE AVE. RANGE
Hillside Zon~ 43.3 <3,0, 10.7 4.3, 1.376.9 I:!~, 456 166,
(1.39) :!07.0 36.0 15.600 1.110
Hillside Zones'" 117.6 46.6 - 57.8 13.0, 5.356 1.890, 4.055 94)',
(40-49) 300.0 181.0 13.700 16.100
.:I i'AJllt""S I tJuough .'~ indud,,' ':'1"1,:41:<0 will.... \lh," liun",," HIli Seh:.
h :I'(lIt~:i 4U lhruu:h 4';1 meiutlc: ttws.,. :ar,:..s ~r()Und Uk." defunct Smelter Complex.
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It-ILiNGS IMPOUNDMENTS
The CIA and the Page Pond tailings. impoundments contain a total of approximately 18 million
cubic yards of flotation tailings. For the CIA flotation tailings, maximum measured arsenic.
and cadmium concentrations (692 mg/kg and 45.2 mg/kg, respectively) occurred in surficial
dust samples. Maximum measured lead and zinc concentrations (7,760 mg/kg and 7,990
mg/kg, respectively) occurred in composite core samples. IDHW characterized Page Pond as
a dust source by averaging concentrations from individual dust samples. A verages of
measured concentrations from Page Pond surface samples were 202 mg/kg arsenic, 38.7 mg/kg
cadmium, 4,350 mg/kg lead, and 4,260 mg/kg zinc.
GYPSUM
Gypsum (calcium sulfate) generated during the production of phosphoric acid was disposed in
impOundments in upper Magnet Gulch, on the valley floor near the mouth of Magnet Gulch,
and in the CIA middle cell. The gypsum contains relatively low metals concentrations but was
found to be readily soluble and was identified as a source of sulfates, fluoride, and other
inorganic non-metal constituents (Table 5-3). The A-4 and A-5 Gypsum ponds are 'potential
source areas for fluoride although it was not analyzed during the RI.. .
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T bl 53
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a e - I
Maximum Concentration(in rng/kg)
for Selected Parameters in Gypsum Samples
Parameter A-4 Mean Value A-5 Mean Value Background"
Arsenic 4.8 4.8 <.10
Cadmium 5.4 6.9 0,8
Lead 39.7 128 43
Zinc 33.6 216 95
Carbonate 6,190 6,090 --
Sulfate 395.000 405.000 --
Sulfur-Total 159.000 164.000 --
. Source: Gott and Cathrall, 1980
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SLAG
Granulated slag in the CIA west cell contains highly elevated concentrations of metals.
However, these metals are generally regarded as being immobile and unavailable for transport
due to their incorporation in a silicate matrix, which limits leaching, and the relatively large
particle size of the slag, which limits wind transport. Maximum metals concentrations
measured in the granulated slag were 172 mg/kg arsenic, 51.8 mg/kg cadmium, 5,850 mg/kg
lead, and 23,650 mg/kg zinc.
MATERIAL ACCUMULATIONS
Discrete accumulations of various high-concentration' products, by-products, residues, and
wastes are present in indoor and outdoor areas within the Smelter Complex. Indoor
accumulations are sheltered and subject t~ .'limited dispersal, except where structures are in
poor condition. Outdoor material accumulation sites have contributed to soil, surface water,
and ground water contamination. . Soil contamination is generally greatest adjacent to and
underlying the various sites and may extend to depths of several feet where infiltration and
earthwork have occurred.. The largest. material accumulation pile in the Smelter (:omplex
noted during the RI was the copper dross flue dust pile (CDFDP) in lower Magnet Gulch; The
CDFD was sprayed with surface sealant during the RI to reduce its potential as a wind-blown'
dust source; the CDFD was subsequently relocated to the Lead Smelter. duririg Spring 1992.
Salvage of contaminated materials from. the Smelter Complex with subsequent transport to
offsite areas was identified during the RI as 2 contaminant dispersal mechanism. as was
transport (If contaminated dust and mud on vehicles. -Imminent threats associated with the
. Smelter Complex are currently being addressed .by the Smeller Complex owners;' as required
by the September 1991, Administrative Order. .
Some isolated occurrences of oil-stained soils in the Smelter Complex contained PCBs in.
concentrations ranging from non-detectable to' as high as 2 I 8 mg/kg near the Lead Smelter's
water softening building. Numerous pieces of -PCB-containing electrical equip men! wer.e
remov~ and disposed of from the Bunker Hill Mine. Asbestos containing materials (ACM)
were identified in some Smelter Complex buildings and equipment (e:g., insulations, roofing,
and siding materials). Most of the loosened and damaged ACM at the Smelter Complex was
removed during a 1989 CERCLA removal action.
A[R
Wind-mobilization and redistribution of contaminants from soils and surficial materials was
identified as a major site wide transport pathway impacting the Populated areas of the Site.
Historical data collected by IDHW indicated that prior to the lead smelter and. zinc plant
closures, airborne lead was the primary contributor to elevated blood lead levels in human
populations at the Site. Construction of the sulfuric acid plants and tall stacks (1977) resulted
in significantly decreased sulfur dioxide and lead concentrations in onsite air. Lead and total
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.
..
suspended particulates (TSP) concentrations decreased further, following closure of the Smelter
Complex. However, sources of wind-blown contaminants remaining at the Site include the
CIA, Smelterville Flats, the Mine Operations Area (MOA), Smelter Complex facilities and,
properties, Page Pond, parking lots, railroad ,ROW, and other public and commercial facUities.
RI air quality data were collected from the Smelterville and Kellogg Middle School areas
between November 1987 and November 1988. Maximum daily TSP concentrations were
measured at the two school stations during a September 1988 dust storm. Weekly TSP
concentrations at the two stations averaged 69.5 p.g/m3 and 40.8 p.g/m3, respectively. Weekly
maximum and mean lead concentrations at the Smeltervil~e station were reported at 1.35 and
0.312 I-Lg/rn3, respa:tively; and the weekly maximum and mean iead concentrations at the
Kellogg Middle School were reported at 0.310 and 0.095 p.g/m3, respectively. In general,
higher lead concentrations in air correlate with higher TSP concentrations, and the highest TSP
and metal concentrations were occasionally reported during the winter months.' The National
Ambient Air Quality Standard (NAAQS) for TSP (150 I-Lg/m3) was occasionally exceeded auhe
Smelterville and Kellogg Middle School stations during high-wind events. The NAAQS for
lead (1.5 p.g/m3 and 0.5 p.g/m3 proposed) is based on the three-month average of daily lead
concentration measurements. This standard was not. exceeded at either monitoring station
during the RI.
Fugitive dust model (FDM) predictions' indicate' that .air transport pathways impact the,
populated areas of the'Site. Dust source data from the summer of 1988 were used to prediCt
the contributions to airborne lead concentrations 'during wind-blown dust events at six
populated area receptor zones from specific sources within the Site. The resu!ts of the mOdel.
simulations are discussed below. " . , ,
. Smeiterville Flats Sources -'Receptor sites in Smelterville and lower Government G,ulch'
were predicted 'to receive 88 percent and 53 percent, respectively. of their airbor:ne lead
concentrations from dust sources in Smelterville Flats. Approximately 28 and 23 percent
of the lead transported to the receptor zones of northwest, and northeast ,~ellogg,
respectively, was also attributed to this source area.
. CIA Sources - CIA dust sources were predicted to contribute approximately 21 percent of
the airborne lead concentrations in northwest Kellogg and less than .10 percent to oth.er '
receptor zones within the Site.
. Smelter ComDlex Sources - Sources in the MOA were predicted to contribute
approximately 65 percent of the airborne lead in west and south Kellogg and Wardner.
Southeast Kellogg may receive over 30 percent of its airborne lead concentrations from
the MOA. The Lead Smelter lead contribution to lower Government Gulch .was estimated
at approximately '22.5 percent. Other Smelter Complex sources accounted for less than
10 percent of the predicted lead levels at the other receptor zones.
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..
~
. Hillside Sources - FDM predictions indicated that source areas on hillside slopes
contributed approximately 26 percent and 16 percent of the total airborne lead
concentrations at receptor sites in southeast and northeast Kellogg. respectively. The
hillsides were predicted to contribute less than 10 percent of the total airborne lead in the
other receptor zones. . '
Dusts that are dispersed from the sources described above may ultimately be resuspended and
redistributed to other areas of the Site or offsite areas.
Since completion of RI field investigations, an increase in Site vegetative cover has been
observed and measures have been taken to reduce potential fugitive dust generation that may
result in an overall reduction of wind-blown contaminant transport.
SURFACE WATER
During the RI, baseline and runoff surface water quality samples were collected. from stations
along the SFCDR, perennial tributary gulches, and other locations throughout the Site. The
collected data show that surface water entering the Site. is Of poor CJuality and is further
degraded by a variety of inputs within the Site boundaries. Comparison of baseline data
collected by U.S. EPA during the early and mid-1980s with those collected during the RI
indicate an overall improvement in the water quality of the SFCDR within the Site. .
The RI surface water data were compared. with. Federal. Primary and Secondary Drinking.
Water Standards (DWS) and Aquatic Life Criteria (ALC; both Chronic. and. Acute). . . Surface
water transport pathways were quantified in the RI Report in . terms .ofcombined metals.
loadings (CML) expressed in pounds per day (lb/day).CML was defined as the sum .of the
reported concentrations of arsenic, cadmium, cobalt, lead, and zinc multiplied by. the
volumetric flow rate and appropriate unit conversion. factors. .
The DWS and/or Chronic ALC for lead, cadmium, and zinc were commonly exceeded under
baseline flow conditions at stations upgradient and within the Site. Table 5-4 compares ALC
to both low flow and high flow concentrations for zinc, cadmium,. and lead at various
locations. Maximum baseline cadmium, lead, and zinc concentrations recorded at Elizabeth
Park upstream from the Site boundary were 0.015. mgll, 0.057. mg/I. and 2.22 mg/I,
respectively, whereas the maximum concentrations of those metals reponed at the downstream
Site boundary were 0.017 mg/I, 0.188 mg/l, and 2.76 mgll, respectively. In general, most
constituent concentrations were higher during baseline low-flow conditions in . late summer and
fall than during higher flow conditions. During storm runoff events, maximum concentrations
of total arsenic, cadmium, lead, and zinc in the SFCDR at the western (downstream) Site
boundary were 0.045 mg/l, 0.047 mg/l, 0.931 mg/I, and 4.09 mg/I, respectively. Nearly all
SFCDR runoff samples exceeded the DWS and Chronic ALC for cadmium, lead, and zinc,
while arsenic concentrations were generally below Chronic ALC and DWS. levels. Increased
metal concentrations in the rising limb of the discharge hydrograph were attributed to the
scouring of metal-laden materials frOI11 [he stream bed and other source areas during the initial
phases of runoff events.
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LOW AND HIGH FLOW CONCENTRATIONS OF METAL
STREAM STATION ~:ONTAMINANTS, 1987 - 1988 [Total, mg/l]
LOCATION ZINC CADMIUM LEAD
LOW HIGH LOW HIGH LOW HIGH
SFCDR Elizabeth Park (SF2) 2.17 0.731 0.015 0.005 0.012 0.022
SFCDR Valley (S F5) 2.52 0.936 0.012 0.007 0.035 0.021
SFCDR Below Pine Creek (SF8) 2.39 0.668 0.010 0.006 0.039 0.188
"',
I Government Gulch Near Mouth (GG3) . 5.92 3.8 0.293 0.153 0.036 0.022
-
w
Milo Creek At Mouth (MC2) 0.357 0.882 < 0.002 0.005 0.061 0.240
Grouse Creek Above East Swamp 0.086 1.38 0.001 0.008 0.007 0.060
(GCI)
Humboldt Creek Above West Swamp 0.523 1.40 0.004 0.007 0.005 0.025
(GCI)
Pine Creek Near Mouth. (PC2) 0.110 0.071 < 0.002 <0.004 <0.019 < 0.005
FEDERAL WATER QUALITY CRITERIA
(chronic), mg/l ! '. 0.110 0.0011 0.0032
aquatiC life [100 mg/l hardness]
"
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.
l'
Surface water transport was identified asa major migration pathway for contaminants in the
. dissolved and solid phases within and exiting the Site. Although concentrations of
contaminants do not vary greatly between the upgradient and downgradient. Site boundaries, a
combination of contaminant contributions and increased flow significantly increase the metal
loadings leaving the Site. Baseline CML estimates for the SFCDR at the western
(downstream) Site boundary under low-flow conditions (September 1987) and under high-flow
conditions (May 1988) were 959 Ib/day and. 7.200 Ib/day, respectively. CML sources to the
SFCDR identified during the RI included the following: .
. Inflows from upstream of the eastern Site boundary. CML estimates ranged from 633 to
3,420 Ib/day;
. Upper zone ground water inflows in gaining reaches of the SFCDR. The estimated. net
CML from ground water to the river was 657 Ib/day in September of 1987; over 400
Ib/day of this loading was estimated from seeps in the south bank of the SFCDR near the
CIA;
. Erosion,transport, and dissolution of contaminants in stream-bed .and bank f1Iaterials..
contaminated .soils. and material accumulations and residuals within the Site;
. Perennial tributary streams impacted by mining, milling, or smelting operations.
Estimated CML under baseline conditions were 1.96 to 68. T lb/day for Milo. Creek, 2.46
to 67.7 Ib/day for Bunker Creek. 2.02 to 101 Ib/day for Government Creek, and 3.52 to
153 Ib/day for Pine Creek;
. Discharges from the Page Pond and Smelterville wastewater treatment plants.
estimates were 2.03 to 6.86 Ib/day and 0.045 to 7.15 Ib/day, respectively; and
CML
. Stormwater runoff from the Smelter Complex a!1d hillsides was identified as contributing
large pulses of contaminants to the surface water system. Some of this runoff is routed to
the CIA through drainage pipes and channels; however, a portion of the runoff from
Government, Magnet, and Deadwood Gulches, .MOA, Lead Smelter, Zinc Plant, and
Phosphoric Acid/Fertilizer Plant enters Bunker or Government Creeks and ultimately the
SFCDR.. .
GROUND WATER
A water well inventory indicates that a few residences rely on well water; most of the
residences within the Site receive potable water from a municipal supply obtained from areas
upgradient of contamination. Therefore. ground water at the Site is generally not used as a
source of drinking water, and industrial use of Site ground water currently occurs infrequently.
Rl data indicate that the Site ground water has been contaminated by the previously described
sources. Ground water quality data were compared with Federal Primary and Secondary
Drinking Water Standards as a means of interpreting monitoring results and evaluating the
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..
~
impacts of Site contamination to the ground water system. CMLs for ground water were'
estimated as a means of assessing the relative contributions of specific .source areas to the
upper wne of the SFCDR Valley ground water system. RI data indicate that the DWS for
Cadmium and zinc were exceeded in most monitored areas of the upper zone; the cadmium
DWS was exceeded near the east Site boundary, indicating an impact from upgradient sources.
Exceedances of arsenic and lead in the upper zone were localized in the CIA and Page Pond
areas. The DWS for cadmium was exceeded in lower zone ground water in the Kellogg and
Smelterville Flats areas. The zinc secondary standard was exceeded in the lower zone in a
small area near Portal Gulch and in the area from the mouth of Magnet Gulch to Pinehurst
Narrows. . .
Measured concentrations of arsenic, cadmium, cobalt, lead, and zinc in all monitoring well
samples were averaged over four' sampling periods. The maximum average values are
summarized in Tables 5-5 and 5-6 as follows:
Analyte
Primary (I) I II
and Average
SecondarJ (2) Cone.' W~II
DWS mgll Number Well Location
mg/l
0.05 (I) 0.154 GR-S . SW Corner. CIA Middle.Celi
0.005 (I) 0.539 GR.S SW Corner. CIA MiddleCdl
NS. 0.067 GR-] North of CIA West Cell
0.005 (2) 0.403 GR-52U Concentrator Area
5 (I~ 50.5 GR-60 SE Corner. CIA Middle Cell
Arsenic
Cadmium
Cobal!
Lead
Zine
a Concentration data coll~w;h:d from ~ach monitoring w..:ll during Lh~ RI w..:r..: averaged over four sampling. p..:riod~. -Maxintul11
Avcrag..: Conccnlnation- indical~s the lart!csi avcrag~ conc:..:ntt'8lion nOI~d ror any of Ih..: w..:lIs 5ampl..:d.
b NS: Nb Siandard fur Cobalt.
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.,
....
Anal yte
Primary (I) Maximum
and . Average
Secondary (2) Conc:."
DWS. mg/l
mg/l
0.05 (I) NO"
0.005 (I) 0.307
N~ NO
0.005 (2) NO
5 (I) 18.7
Well
Number
Well Location
Arsenic:
Cadmium
GR-ILSlLD
Mouth of Government
Gulc:h
Cobalt
Lead
Zinc:
GR-ILS/LD
Mouth of Government
Gulc:h
a Conc~ntralion data ~ull..:c,,:d fn)n, ~.,;h fn(.nilorin~ w-:II during th..: RI w.:r..: o1Iv":r1Ig~d oVt:r {our $a111(tling p.:rioda...
"Maximum Avera!,!e Concentration- indicateHhc largel! average concentration noted for any oflbe wells sampled.
" ND: NO! D.:lccled Durin:: .h.. RI. .
I c N:5: Nc :5land...d lor Coca II. .
II
~
DWS for cadmium, lead, zinc, fluoride, and sulfate were exceeded in one or more monitoring
weIIs in Government Gulch and orher wells in the Smelter Complex (See Table 5~ 7). The
poorest ground water quality observed at the Site occurred in upper Government Gulch south
of the Zinc Plant and was probably associated with leaching' of metals from a former materials
storage area. .
CMLs for ground water were estimated as a means of assessing the relative contributions of
specific source areas to the upper zone of the SFCDR Valley ground water system.. The
estimated ground water CML at the western (downgradient) Site boundary was approximately
208 Ib/day based on September 1987 RI data. The sum of the CMLs entering the SFCDR
Valley system from upgradient and from on site sources was estimated at approximately 986
Ib/day. However, the surface and ground water systems in the SFCDR valley are linked by
three identified gaining river reaches and two losing reaches. The net effect of these multiple
losing and gaining reaches is a CML transfer from the ground water system to the SFCDR;
this transfer was estimated at 657 Ib/day based on September 1987 data presented in the Task
3 Data Evaluation Repon. .
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..
..
Maximum Concentrations in mg/L
Sample Location Cadmium Lead Zinc Fluoride Sulfate
GR-IUS 0.25 <0.025 17.4 10.9 853
GR-IUD 0.462 <0.025 24.1 9.57 917
GR-ILS 0.615 0.017 31.7 4.74 333
GR-ILD 0.086 0.012 11.1 1.01 279
GR-32S 0.648 0.451 20.50 1.09 166
GR-32D 0.008 0.006 0.347 0.10 94.1
GR-36 27.8 0.017 662 0.698 1350
. Drinking
Water 0.01 (I) 0.05. (I) 5.0 (2) 4.0 (I) 250 (2)
Standards
I (I) D~nol~' Primary Siandards
(2) D.:r.OIC" Secondary Slen.larcb
Approximately 75.8 Ib/dayof CML was transported in ground water across the eastern Site
boundary from upgradient source areas based on September. 1987 data. . The largest onsite
ground water loading source was seepage from the ponded area of the CIA east cell through
flotation tailings; the CML in this seepage was estimated at 683 Ib/day. Site wide infiltration
through jig tailings deposits was estimated to be the second largest loading source at 168
Ib/day. Discharge from the Government Gulch tributary system to the upper and/or lower
zones of the valley system was estimated at 14.5 Ib/day. and all other sources were each
estimated to contribute less than 10 Ib/day to the valley fill upper and lower zone aquifers.
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"
.~
6 SUMMARY OF SITE RISKS
6.1 HUMAN HEALTH RISKS
Risks to human health associated with exposures in the Non-populated Areas Site media were
evaluated in the Human Health Risk Assessment (June 1992) (HHRA). This evaluation was
third in a series of risk assessment efforts addressing both the Populated and Non-populated
portions of the Site. All exposures for this Site were evaluated either as baseline or
incremental. Baseline refers to exposure resulting from activities common to all members of
the resident population. Incremental exposures result from potentially high risk activities by
some members of the local population or visitors to the area. Risk associated with baseline
activities of the resident population were addressed in the RADER (October 18, 1990).
Potential baseline exposures evaluated in the RADER included ingestion of residential surficial
yard soils and house dusts, inhalation of particulate matter, and consumption of water from
local public supplies. Incremental activities evaluated in the RADER included potential
consumption of local ground water, ingestion of soils from severely contaminated areas,
extreme ingestion rates of soils/dusts by children (pica-types behavior), consumption. of local
fish and garden vegetables, and inhalation of outdoor airborne particulate mauer during
episodic high wind conditions. . .
Unacceptable risk levels in the populated area were associated with sev.eral of these exposures.
Actio11s addressing cleanup of residential soils, houc;e dusts. and fugitive dusts were developed.
in the Residential Soils ROD and the 1991 and 1992 Administrative Orders.
Risks associated with potential exposures in the Non-populated Areas were evaluated as
incremental to assumed post-remedial baseline exposures in.the Populated Areas. .
Contamination of Site media is extensive throughout the Non-populated Areas. Contaminants
of concern in.all media include antimony, arsenic, cadmium, copper, lead, mercury, and zinc.
Additional concerns may be expressed with respect to asbestos, cobalt, (PCB), and particularly
mercury compound exposures to workers in the abandoned industrial complex. Potentiahisks
resultant from the latter exposures were not quantified in the HHRA because they were
detected only in localized areas within the individual complexes.
Contaminated media in the Non-populated Areas include soils and dusts, sediments, surface
water, air, and ground water. The highest contaminant concentrations are noted in residual
material accumulation piles, buildings, and process facilities throughout the Smelter Complex.
Ground.water and surface water contaminant concentrations exceed drinking water maximum
contaminant levels (MCLs) and aquatic life criteria (ALC) throughout many areas of the non-
populated areas.
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.
,..
Contaminant migration is ongoing throughout the Non-populated Areas. Airborne, surface and
ground water, and mass movement pathways are all active and continue to redistribute residual
metals across the Site.
Potential risks were addressed in two major categories including:
8 Risks associated with contaminant migration from Non-populated Areas sources into the
residential portions of the Site where the general population is exposed; and,
8 Incremental risks associated with direct contact with contaminated media by members
of the population engaged in specific activities. .
With respect to human health issues, the most significant contaminant transpon phenomena
are:
8 Airborne dusts that result in excess respiratory cancer risk from arsenic and 'cadmium,
and redistribute particulate lead to residential soils and house dusts that are: a source of
excess lead absorption in the.resident population.
.8
Contaminated ground water that exceeds MCLs and' presents excessive carcinogenic and
non-carcinogenic risk through. potential ingestion of arsenic, cadmium, manganese,
lead, and zinc.
. Surface water transport of dissolved metals and 'contaminated sediments that can
redistribute lead and other metals [0 areas accessible by the local population.' ,.
With respect to direct contact with contaminated, media, the most significant concerns, are
associated with exposures related to potential land use in the Non-populated Areas. Risk,
scenarios ,were evaluated for future residential, recreational, 'and occupational use of the Non-
populated Areas. Both carcinogenic and (chronic and sub-chronic) non-carcinogenic risks were
evaluated. The Non-populated Areas were divided into geographic sub-divisions for the
HHRA analysis. Those sub-divisions were:
8
.
Hillsides
Smelterville Flats
Smelter Complex
Mine Operations Area
Page Ponds
CIA
.
.
.
.
Table 6-1 summarizes route specitic carcinogenic risk for the baseline population. Incremental
carcinogenic risks exceeding acceptable criteria were obserVed for arsenic in ground water, in
soils for children exhibiting pica-type behavior in several areas, and for adult occupational
scenarios in the industrial complex and other highly contaminated areas of the Site.
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..
..
Unacceptable Chronic non-carcinogenic risks (i.e., those exceeding Hazard Indices (HI) of 1.0
per U.S. EPA 1989) are summarized in Table 6-2.
Sub-chronic non-carcinogenic risk was evaluated for lead exposures to children and pregnant
women. For children a biokinetic modeling methodology was employed. That analysis
identified soil lead levels exceeding 1000 mg/kg as a threshold cleanup level for residential
soils (CH2M HILL 199 I). Geographic sub-units of the Non-populated Areas were evaluated
against the criteria as shown in Table 6-3.
Summary risk assessment findings for future use scenarios for the Non-populated Areas sub-
units follow:
. With respect to potential residential development, some hillside areas remote from the
industrial complex meet. the soil le2d cleanup criteria established in the Residential Soi!
ROD. No other areas were suitable for residential development at current contaminant
levels. ..
. Any portion of the Non-populated Areas not suitable for residential uses are also
considered inappropriate for recreational development that. would attract preschool
children (e.g., picnic areas or playgrounds).
. Regarding potential recreatiorial. activities, the- majority of hillsides outside of the.
immediate vicinity of the Smelter Complex are. suitable for unrestricted activities under
current conditions~ The entire SmeltervilIe Flats; Mine- Operations Area, abandoned
Smelter Complex, - the adjacent hillsides, and gulches are currenl!y unsuitable for-
recreational activities for either children or adults. The most significant risks are
associated - with potential sub-chronic lead poisoning due to contact with contaminated
soils, dusts, and sediments. Chronic non-carcinogenic disease could also result from
continued cons!Jmption of surface waters during recreational activities.
. With respect to potential occupational uses of the Non-populated Areas, women of
reproductive age that may become pregnanC are the -population of concern. - Common
occupational activities by pregnant women could more than double prenatal-exposures to
lead in all areas except the general hillsides. Especially severe exposures could occur on
a short-term basis within the abandoned complex, the CIA area, or the Mine Operation
Areas. Within these latter areas, workers are potentially at-risk for both carcinogenic
and chronic non-carcinogenic disease under a 35-year occupational scenario.
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LOCATION
Smdlc:rvillc:
0-
I
I.'
Kdlogg/
Wardn~r/
Pag~
Pin~hllrsl
Had;!;l"lJuOlJ
HOUSE OTHER
CONTAMINANT INHALATION YARD SOIL DUST SOIL/DUST DRINKING
INGESTION INGESTION INGESTION WATER
Arsc:nic
Cadmium
....Total
Arsenic
Cadmium
.To.hil
Ars~nic
Cadmium
Tolal
Ars~nic
Cadmium
.:1'otal
..
...
7.8 x 10'~
MARKET
BASKET
FOOD
8.6 x 10"
1.0 x 10'~
TOTAL
ORAL
TOTAL
ALL
ROUTES
I. I x 10')
2.8 x 10')
5.7 x 10"
1.2 x 10"
8.1 x 10"
5.8 x IO'~
:. . ./. \\4:1;':t~~l!;:;'I::,z;~:;xIM'
3.8 x 10" 2.2 x 10'.'
1.8 X 10"
'....5. 7"'~';:1Q\~:';:.::::::I:!:i.:~':;~.;~':i:')~~':j.. .:. :.8;) '..x"..t:o;~:il!:::.;:'::i:!;ill.i'~::i'li'.~i,~:.!:i:.:'i.ij::i';:i'~;'~.'i::::'i:~i:'.::!:::::.;::l'~'il::;!".:r.~~~.'.
5.8 X 10') 9.5 X 10.6 8.1 X 10" 8.6 X 10'- 1.0 x W). 1.1 x 10')
....::5~.~."'~:':'~;~:~;:':":!:::::'.::i:~';?:'~::.l.Q'~{:.:': ...: 5. 8:~":']0;'!':::.::::::;.~jj!~;~:::~Ji.::!V~'i:;!::'.:,;.:;::,ilj:;'::!O~j!i.I!I!!lllit.Ij[~II::I.~!~i!!i!!::!!!:!:ii!jl:I:I:I:{~%:.::!i:jii:i:.;.:j:;!j::'I~.;:.:{~!~:.:;
4.7 x 10.6 1.3 x io') 7.2 X 10.6 5.4 x'IO'6 8.1 x 10" 8.6 x W' 9.6 x 10" 9.8 x 1'0'-
1.4 x 10'~
..... ...
. . . . .
I ~ Q '!~\TQ:f":
.'. ",. '..'
:l;~:::;' 10"
5.1 x'IO.6
7. 2: :~"'I u~':;';':::::":;:i;::~04':~::ii:ti~'.:"8.'i""Jt 'i.O;~::::!::,,'::':;:i:I.!:~':iRI.'lQj~:::;::;':::;:::;~';:~'.i~:'i6'4':;:.:';::';,,:'~:jg:.'i'::::I~~~:'.
2.4 ,10') 2.2 X 10.6 8.lx 10" 8.6 x 10'4 9.6 x 10'. 9.8 x 10'.
4.7 X 10.6
5.7 X JO.6
2.4j!j~:!~i1~]iiiij!:I~I~I:ii:;li~~~i!lllir':'::~J~!I~:;:!jf:.~~fi;lil!II~III'I(I~:llilrjli:'il.I:III~i!:lllli1~1~II:I::i!il!IIIII.~~~!ijl:!lli~~;1.llj!
Cuntanllnanls :nlll l11~lIia lilr which risk is nol ~slil11al~d is lIu~ 10 lack of an appropriate CPF and/or media concentrations from which intakes
~an h.: .:stimal.:lI. CPFs art: available only for ars~nic'{oral and inhalation) and cadmium (inhalation only). 1990 value CPFs utilized.
BackgnHlI1d carcinogenic risk associaled with market baskel foods was assessed using arsenic oral Cancer Potency Factor (CPF) found in 1989
U.S. EPA.YEAST Tahles and contt:mporaneuus FDA estimalt:s of ars~nic in food. A significant portion of arsenic intakes from the market
haskd is assu~ial~d wilh st:afood consumption. may b~ 'rapidly ahsorbed and excreted. apd may not pose the same level of risk as inorganic
ilrs.:ni~ ingestion. . . .
(a)
(h)
..
-------
..
.
:.;..::::?::.:'
..
, ': .' :::::"::~';::-
..
...
...
...
.: .;:'.
..
..
...
...
..
...
'::~:;\~\~~j~~~~t~~~:~~~:~?:. . '.;.:~~~:~.:' .
':~::.::.::::.:::: .:.: :~:::::':.:::'.::.:..: ::;',:: .
.. .. . ..' .
.. . .......
","'''',',','''',",', . ..'
...
Due: to arsenic cxposun:s:
Smo:llo""illo Rosidential
S"",lIo""illo Flats
CIA, Industrial Complex
Min.:/Mill Arca
Lead Smelter
..
ba""line plus ground water .:"nsumption, HI ~ 1.1
basolin.: plus ground water c"nsumption, HI ~ 1.9?
b..""lino plus ground water consumption. HI ~ 2.St!"
basoline plus occupational dust. HI ~ 1.0
baseline plus occupational dust, HI ~ 1.3
. Magnet Gulch . baseline plus occupational dust, HI ~ 1.2
Due to zinc (and lead-) expo.......:s:
Smclle""illo Residential
Kellogg/
Wardner/Plge Rcsidential
haseline plus ground water .:"nsumption. HI ~ ~.I
baseline plu~ .8.ro."!:,d watcr consumption. .HI ~ 1.5
.' .
Smel1c",illo 'Flals. CIA: ha..,lino plu:i ground wator~onsumption. HI ~ l.5e
Mine/Mill. Industrial ba...line plus ground wator .:".....mplion. HI ~ 1.1"
'~111~~~I.IJ}:[:~::[:~:~::::j:::::;:;i;,[[i:*::;~~:::~:M:::~1:~;1::~:;~)~:::~:!:::i!:i:;;:j::::~;:;:i;~:;;ij::::;:,::::,::;::,:::~t'::::;:::::;;;:::~,::::::',;:.::,,:::;,:":~::j,::,::,:::::i;i~;'~::;',,,,: ., .....'. . ,"". ,
Due to antimony and copper
exposures:
Lead Smelter
Residential An:1S
Smdle!'Vilie Flats. CIA,
InduSI""1 Complex
. '.'.'.'~' .: ":-. :.....:,', "'.',~ .",:".:-:.:..,:...'.:.::. : :.:.:..:;. ,..,.,-;:. ':" :'.' ...
':'$~'J#@il!W1~!iM::;:~:i.:i,,:j,}\{>'.: ,.
. Due to cadmium and In.:rcury (amI'
lcad.) exposu
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..
'.
Table 6-3
Non-populated Areas Geographic Units
That Exceed the Residential Areas Soil Lead Action Level of 1000 ppm
SOIL LEAD CONCENTRATIONS (ppm)
LOCA nON
mean extreme
HILLSIDES 1,015 2,360
CIA- T AIUNGS POND 1,675 13,400
PHOSPHATE PLANT 1,752 14,000
LANDFILL 2,104 2,730
MINE DUMPS 2,977 16,300
ACID TANK FARM 3.299 73,200
LOWER GOVT. GULCH 3.641 6,930
DEADWOOD GULCH & SLOPES 4.201 37,400 ",
PAGE POND SWAMPS 4,302 6,000
, SMELTER HEIGHTS 6,084 104,000
CIA-GYPSUM POND 6,112 85,210
I S.FLATS NORTHEAST ,8.285 15,900
I S.FLATS N.FLOODPLAIN 10,672 I 17 , 700
i
CIA--SLAG PILE 10.855 29~ 100
ZINC PLANT 17,605 132,000
M/M-BOULEV ARD 18.692 79,500
S. FLATS IND. CORRIDOR 18,867 29,000
UPPER GOVT. GULCH 24,629 133,000
M/M-CEN.TREAT. PLANT 36.369 48.700
M/M ACTIVE MINE 36,956 242.000
MAGNET GULCH 48,796 143.000
LEAD SMELTER 48.796 178.000
Source:: RI Data
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.
,
, I
1
. Acute exposures representing an immediate threat to life and health could result from
"short-term exposures in the Smelter Complex or Mine/Mill Areas. While" no specific
criteria or thresholds have been identified in the two areas for short-term exposures it is
nonetheless prudent to avoid even minimal" contact" with the high con"taminant
" concentrations exhibited in these locations. In these" areas, exceedance of 10,000 mg/kg
concentration levels (10 times the Populated areas cleanup level) for lead are common.
Antimony, arsenic, cadmium, and mercury are also highly elevated. Excessive risk of
acute toxic effects could also result from heavy metals and arsenic exposure in the CIA
Area, the Smelterville Flats, and Hillsides adjacent to the industrial complex. (SAIC,
1992). "
6.2 ENVmONMENT AL RISKS
Soil, sediment, surface water," and ground water within the Site exhibit elevated levels of
antimony, arsenic, cadmium, copper, lead, manganese, mercury, silver, and" zinc. Lack of "
vegetative cover over much of the Site has resulted in the loss of wildlife" habitat "and increased
soU erosion. "Concentrations of metals over large areas" of the Site adversely impact both
aquatic and terrestrial biota." "
Current levels of cadmium, lead; and zinc" in surface water adversely". affect resiqent
populations of benthic organisms, fish, and aquatic plant species. Acute" and "chronic "ambient
water quality crite"ria for these metals are substantially exceeded in" the SFCDR.. Low frO\V "
contaminant loading information in the RI indicates that approximately 700 Ibs/day" o.r zinc, "
eight Ibs/day of lead, and four Ibs/day of cadmium enter the SFtDR from ~ithin the Site.. "
A verage cadmium and zinc concentrations in the SFCDR within" the Site exceed" acute" water
quality criteria by approximately three and fifteen times, "respectively. "In" addition, cadmium
and zinc upstream of the site (SF-2) exceed" acute aquatic life criteria by approximately four"
and twenty-one times, respectively. In the Coeur d'Alene River at Cataldo, ~pproximately ten
miles downstream from the Site, cadmium and zinc exceed acute criteria values by aboul two "."
and eleven times, respectively. Contamination upstream of the Site contributes to excessive
metal loadings found in the river and are combined with metal loadings: within" the Site "via
surface water runoff and ground water contamination. An environmentally significant threat
exists to aquatic populations and trophic diversity in the Coeur d'Alene River"as a result of the
South Fork water quality.
Although tolerant species of fish and benthic organisms appear to be re-establishing within the
Site, toxicity tests on rainbow trout and water fleas conducted during the RI show that lethal
conditions for less tolerant species currently exist in the SFCDR. Persistent contamination"in
the" SFCDR and natural processes such as erosion and flooding continue to alter water and
sediment quality upstream, within the Site, and in the lower reaches of the Coeur d'Alene
River.
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II
.
Average concentrations of antimony, arsenic, cadmium, copper, lead, mercury, silver, and
zinc in hillside soils exceed reference (background) concentrations by as much as 50 times for
lead, 25 times for cadmium, and 12 times for zinc. These elevated levels are also a source of '
contamination in the surface water, ground water, and sediments and are poteJ:]tially toxic to'
terrestrial biota. The following Table 6-4 shows soil toxicity reference concentrations that may
induce toxicological effects on plants, soil invertebrates, and small mammals; it also provides
the approximate acreage that may exceed the reference levels. .
Estimated intake levels for mice, deer, and waterfowl compared with toxicological reference
values indicate that current arsenic and zinc levels in localized areas are likely to cause adverse
effects in small mammals. Lead and silver levels are also expected to have sublethal effects 011
small mammals, while antimony, copper, and manganese concentrations in soil may have
sublethal effects on less tolerant individuals. Figure 6-1 shows major Site areas where soil
metal concentrations exceed projected toxic levels. Approximately 850 acres in the vicinity 'of
the Lead and Zinc Smelters< and ,450 acres in Smelterville Flats ,have soil concentrations
capable of inducing adverse toxicological effects on. plants" soil invenebrates, ,and . small'
mammals. Other localized areas of the Site have contaminant-levels that could produce long
term sublethal effects on such organisms.
Waterfowl are particularly at .risk of toxic effects from ingestion of lead in. soil and plants;
however, waterfowl exposure within the Site is limited by the 'general' lack of attractive habitat., '
, The assessment of lead hazards to waterfowl in the Coeur d~ Alene River ,Basin are. complicated' '
by the ingestion of lead shot. Impacts include docume,nted periodiC' acute poisoning, as well as
uncertain chronic effects such as enhanced susceptibility to disease. predation, and repr:oductive "
impairment. Tissue analyses detected elevated lead levels inaH,' samples' analyzed.
Concentrz.~ions of metals in soil and sediments in some'locaJizedareas.of the basin are 'similar
to those found within the Blinker HiII'Site; however, major differences. exist in their physical
characteristics. Habitat differences between the Site and basin also obscure comparisons 'of.
similar risks.
Impaired tlOphic communities and structural habitat exist throughout the Site and are especially
evident by the barren and sparsely vegetated areas on the hillsides and flats. Elevated metal
concentrations continue to disrupt the interaction and interdependence between soil, plants, 3nd
terrestrial fauna, which are integral components in soil stability, wildlife habitat, food chain
pathways, and nutrient cycling.
Contamination of localized areas alter species composition and occurrence. Soil structure is
deteriorated and the integrity of the organic matter and litter layers are severely reduced. The
maintenance of biogeochemical processes and cycles are also ,altered. Water retention and
erosion control by major water sheds are dysfunctional and can not moderat~, environment41
extremes.
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.
.
Table 6-4
Soil Toxicity Reference .Concentrations
That May Induce Toxicological Effects on
Plants, Soil Invertebrates, and Small Mammals
Soil Toxicity Reference
Concentrations. (mg/kg) Approximate Acreageb
Contaminants '. ...- Exceeding Minimum Reference
Plants and Soil Small Concentration
Invertebrates Mammals
Arsenic 40 78 2500
Cadmium 20 1875 1000
Copper. 60 1350 1800
Lead 1000 2250 7800
Mercury 5 NA 400
.' .
Silver 8 17 8QO
I 2500'.' . '.,
Zinc 500 1260
'.
a As described in the. Ecological Risk Assessment "
b Includes acreage from hillsides, smelter complex area. and Smelterville Flats (north of highway)
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C'
I
.-
c;
t.,~
Q;tv
v
tv .
~e,
o
04:
Note: Other localized areas not shown may induce
. toxic effects to either plants or animals.
MAJOR AREAS CONTAINING MEtAL CONCENTRATIONS THAT MAY
INDUCE TOXICOLOGICAL EFFECTS.ON'PLANTS, SOIL,
. INVERTEBRATES, 'AND SMALL MAMMALS
FIQURE.6..1 ,
.
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.
~
Terrestri.J! and aquatic communities, however, have exhibited some naLural succession, and
several areas have demonstrated signs of recovery. An evaluation of ecosystem indicators at
the Site show a capacity for adjustments and adaptation.
Remedial actions at the Site can. have a significant beneficial impact on the re-establishment of
native terrestrial and aquatic communities within the Site and are expected to cpntribute to
improvements to water quality in lower reaches of the Coeur d'Alene River. Establishment of
vegetative cover in areas impacted by past mining, milling, and smelting operations; control of
wind and water erosion; and minimization of metals loading to surface and ground water will
enhance. recovery of the local environment. .
However remediation of the Site will not restore the Coeur d' Alene Basin, as a whole, to a
condition that existed prior to the advent of mining in the region. Remediation of the Bunker
Hill Site is only one component of what will be a basin wide approach to addressing impacts
from decades of mining, forestry, agriculture, and development in the Coeur d'Alene Basin.
Recently, federal, state, tribal, and local interests have held discussions to build upon past
efforts in understanding basin environmental problems in order to develop a Coeu.r.. d'Alene
Basin Restoration Project. Successful efforts by these groups, coupled with remedial actions at
the Site, have the potential to enhance recovery of .many of the environmental features of the
Coeur d'Alene Basin that have been compromised over the past 100 years. .
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..
"
7 DETAILED DESCRIPTION OF ALTERNATIVES
This proposed cleanup action involves the Non-populated Areas of the Site and those areas
within the Populated areas not covered under the Residential Soils ROD. . These are areas that
are typically used for many different activities and purposes. While it is important that the
cleanup actions block or remove the routes by which people and organisms come in contact
with contaminants, it is also important that the remedial actions allow for continued growth of
the community.
.,'" Remedial actions selected must eliminate, or reduce to acceptable conditions, the routes by
which people and environmental receptors come in contact with or are affected by
contaminants in soil, dust, and water. It is also important that the remedial action not unduly
interfere with resident or community activities during and after the remediation prOcess. The
remedial alternatives were developed with these factors in mind and with consideration given
to present and anticipated land use activities. Institutional controls that assure the integrity of .
remedial actions selected for the Site are an important component of all alternatives presented.
Continued development of the area will. be possible if undertaken consis~ent with .remedial
actions specified in this ROD and managed through the Institutional Control Program (IC?).
, Institutional controls were also an .important component of the Residential Soils ROD, (August,
1991). Previous public comment on the Residential Soils ROD indicated that the community.
would only support an ICP if there were no costs to local citizens or governments.
To achieve an acceptable ievel of protectiveness, the remediai alternatives were' designed' to
attain site wide and sub-area specific Relnedial Action Objectives (RAOs). RAOs are general
cleanup objectives that are established early in the FS process to guide the development of:.
cleanup alternatives. The selected RAOs reflect consideration of risk management principles
and available information identifying contaminants, media of concern and potential exposure
pathways. They represent preliminary judgements regarding acceptabie ,exposures to site
contaminants, from a variety of routes, that are adequately protective of hu~an health and the
environment. . , ,
Biological monitoring is an important component of all alternatives with respect to evaluating
potential impacts on environmental receptors. While each alternative includes extensive efforts
to contain or manage contaminants posing an environmental threat, certain areas of the S.ite,
particularly hillsides adjacent to the smelter complex, may have a potential to impact sensitive
species of plants and animals after implementation of remedial actions. No specific soil
cleanup goals (ARARs) have been established to evaluate risk to environmental receptors,
however, the ecological risk assessment has developed soil toxicity reference concentrations
which are intended to serve as an indicator of potential impact.
While residual contamination may pose a potential threat to environmental receptors at the Site
the FS determined that remediation of all hillside areas to levels below soil toxicity reference
contamination was infeasible. Habitat establishment was, however, determined to be both
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.
.
feasible, and desirable, and is a component of all alternatives presented in theFS. As habitat
is established, and environmental receptors are exposed to residual soil contamination,
monitoring will be conducted to evaluate actual impacts to resident populations.
RAOs are expected to be attained through achievement of remedial action-specific performance
standards. The reliance on performance standards for individual remedial actions is intended'.
to provide a realistic measure of success for the specific actions proposed. They have been
developed to achieve overall cleanup objectives for the Site. Performance standards for the
selected remedial actions are discussed in greater detail in Section 9.2. The performance
attributed to other alternatives is discussed in detail in the FS and supporting Technical
Memoranda.
General response actions (GRAs) and technologies were selected and evaluated based on
effectiveness, implementability, and costin reaching their respective RAOs. Alternatives, or
combinations of 'reme4ial technologies, were then developed for each media and subarea.
Finally, comprehensive site wide alternatives were developed to address the site wide RAOs
for the four principal site media: soil/source materials, ground water, surface water, and air.
As a result, the FS Rqx>rtproposed four. site wide r:emediation alternatives. Except for the No.
Action Alternative which served as a baseline comparison alternative only, all of the site wide.
alternatives, are able to satisfy, to varying degrees; the nine evaluation, criteria, (discussed in
detail in Section 8), required by the NCP to be used when comparing' various, remediation
alternatives.
The proposed alternatives'have been described in the Proposed Plan as 'follows: '
Alternative 1:
Alternative 2:
Alternative 3:
Alternative 4:
No-Action
Source and Institutional Contrors
Source Controls and Treatment,
Removal, Source Controls and Treatment
7.1 ALTERNATIVE I
NO ACTION
Alternative I is the No Action Alternative required for evaluation under the NCP; This'
alternative incorporates those removal actions and Orders already implemented or underway
which were summarized under "Site History" - The determinations made in the Residential
Soils ROD have also been considered in the development of Site-wide remedial alternatives
presented here. As a result of these response actions, transport ot' contaminants via surface
water and air from various onsite sources have been reduced. Additionally. human exposures
to soil/source materials have also been reduced in the Hillside. Smelterville Flats, CIA. ROW.
and Smelter Complex subareas. Alternative I serves as a baseline lor comparison and
evaluation of the other alternatives.
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~
..
. 7.2 ALTERNATIVE 2
. SOURCE AND INSTITUTIONAL CONTROLS
. .
Alternative 2, the Source Containment and Institutional Controls Alternative, was developed as
a potentially effective ~lution. to address Site-wide RAOs, primarily through the use of
containment (barrier) technologies. It is comprised of components that include
containment/stabilization, drainage and erosion controls, and institutional controls. As
compared to the No Action Alternative, Alternative 2 would further reduce the mobilization of
contaminants via surface water and air and prevent human contact. Active ground water
controls are not included in this alternative; however, significant ground water and surface
water improvements are expected over time due to source containment aspects of this
alternative and the considerable efforts being undertaken to establish vegetation on over 3,200
acres of the Site which are currently eroding at excessive rates.
7.3 ALTERNATIVE 3
SOURCE CONTROLS AND TREATMENT
Alternative 3, the Source Controls and Treatment Alternative, addresses the Site wide RAOs
by utilizing a combination of: source containment (in-place caps); selective source removal;
drainage and erosion controls; innovative treatment of ground water and surface water;..
treatment of selected source materials; and, institutional controls. Alternative 3 was developed .
to utilize a combination of innovative and conventional engineering controls and treatment
options with respect to ground .water and surface water in particular. This alternative will also
use cement-based stabilization to treat aU Principal Threat materials (defined in Section 9.2.5)
before they are contained when they are not recycled or reprocessed. This alternative would
reduce and/or eliminate the mobilization of soil/source materials, surface wat~r, ground water,
and air-borne dusts.
'7.4 ALTERNATIVE 4
REMOV AL, SOURCE CONTROLS, AND TREATMENT
Alternative 4 is the Source Controls and Removal Alternative which relies upon: sourc~
removals with disposal in engineered repositories; treatment of ground. water and surface
water; conventional engineering controls; and. institutional controls. . This alternative is
distinguished from Alternative 3 through its reliance on source removal and conventional water
treatment technologies instead of innovative treatment technologies. This alternative would
significantly decrease the impacts of soil/source material contaminants and further reduce
surface water, ground water, and air-borne contaminant transport.
Each of the alternatives (except for the No Action Alternative) has been developed to
specifically address human health and environmental concerns and has identified. specific
remedial actions for soils/source materials, ground water, surface water, and air associated
with each of the subareas. Site wide subarea remedial action alternatives are presented in
Table 7-1. These tables outline the remedial action components designed to address media-
specific and subarea contamination individually. They also delineate the combinations of
actions comprising each specitic site wide remedial alternative proposed. Detailed descriptions
of each subarea and site wide remedial action alternative are provided in the Bunker Hill
Superfund Site Final Feasibility Study Report (May I, 1992) and associated Technical
Memoranda. These documents are. all available as part of the Administrative Record.
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.'"
.
Subarea
Remedial Actions
Alternatives
1 2 3 ,
Hi llsides
Current actions in hillsides including contouring/terracing on barren
areas and revegetation of areas with less than 50% cOYer.
It
x
It
It
Erosion control structures and surface water treatment for sediment
reduction in detention ponds in Deadwood. Magnet, and Governnent
Gulches.
x
x
x
It
Institutional Controls. x x It
Spot re-vegetation of areas with less than 50 percent cOYer within 50. x It
85 percent cover class.
Surface armor or soil cover on selected mine waste rock ~. x x x It
Channelize upper Milo Creek. x x It
Enforce existing controls on access. x x It
Maintain existing fencing. x x It
Slnel tervi lie
Flats
Rock/vegetation barriers on truck. stop and RV park.
Revegetate as
I ::::~utional
Soil or rock barriers on exposed contaminated soils and tail ings that
cannot be revegetated.
practicable; temporary dust control on unvegetated
x x x It
X X X X
X X It
X X
.x
x
x
x
x
Controls.
RemOve selected jig tail.ings"for South Fork' Coeur d'Alene River
chamelization.
Remove selected jig tailings as necessary for wetland and floodway
construction.
Construct ground water wetland ups'tream of Pinehurst Narrows (34
acres) .
Construct collected water wetland treatment system (74 acres).
Construct floodway for South Fork Coeur d'Alene River.
'Collect upper zone ground water at western Smelterville Flats for
w~tland treatment.
Remove all accessible jig tailings for onsite disposal in CIA.
x
Collect upper zone ground water at western Smelterville Flats for
conventional treatment.
x
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..
.
Subarea
Remedial Actions
Al ternatives
1 2 3 "
x x x
X x x
x X
x
x
x
x
x
x x
Central
Impoundment Area
Temporary dust control measures.
Institutional Controls.
Institutional controls to restrict access (fencing).
Regrade, improve drainage and vegetate CIA dikes.
Seal CIA tailings using soil or chemical agents.
Permanent dust control through containment, soil/rock barriers and
revegetation.
Rock and/or soil barrier on A.4 Gypsum Pond.
Collection of upper zone ground water in CIA seep area for wetland
treatment.
Close CIA, soil/clay cap, and revegetate after removal of Smelter
accumutation materials from CIA for onsite disposal and emplacement of
jig tailings from Smelterville Flats.
Collection of upper zone ground water in CIA seep area for
conventional treatment.
x
Page Pond
Temporary dust control.
x
x
x
x
Institutional Controls.
x
x
x
Improve drainage and vegetate Page Pond dikes. .
x
Permanent dust 'control measures (soil/rock) on Page Pond.
x
Rock or soil barriers on exposed jig tailings in Uest Page Swamp.
x
Channelize lower HumbOldt and Grouse Creeks.
x
x x
x x
x X"
x X
Move exposed jig tailings (up to 18 acres) in ~est Page Swamp to Page
Pond.
Regrade, soil cover and revegetate Page Pond tailings impoundment and
dikes after emplacement of ~est Swamp jig tailings.
Enhance existing wetlands in ~est Page Swamp using hydraulic controls.
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*
.
Subarea
Remedial Actions
Smelter CCIq)lell
Fire controls and amual structural inspection.
Temporary dust control on material accumulation sites.
Remove PCB transfonmers and PCB-contaminated soils.
, Repair or remove asbe>itcs matedals.
Chamel i ze and line Governnent Creek.
Institutional Controls.
Move material accumulations and contaminated soi Is to engineered
repository.
Demolish Lead 'Smelter. and Zinc,Plant structures in place and contain
with soil/clay caps.
Relocate Boneyard materials 'Under Smel ter Cap.
Soil/clay cap on landfill.
Reprocess'ing of principal threat and other ,recyclable materials,to
minimize the volume of materials which would be capped.
Cement-baSed stabilization/filiation of the remaining principal threat
materials, with disposal of treated materials under the Lead Smelter
Cap.
Place c~t-off wall in upper Gover~ent,Gclch to divert-~l~an water
away from contaminated areas; place cutoff wall ion lower Go'~arnnent
Gulch to collect ground water for-treatment in the collected water
wetland.
Revegetate disturbed areas.
Relocate A-1 Gypsum Pond to CIA.
Relocate A-4 Gypsum Pond to CIA.
Place demolition debris from Smelter Complell buildings and structures,
soils from under the structures, Boneyard materials, and lanclfi II '
materials in an ellpanded engineered repository. '
Place cutoff wall in lower Government Gulch to collect ground' water
for conventional treatment.
7-6
Al ternatives
1 2 3 4
II
II II II II
X X II II
:< .< II II
II II II
II p X
II II
II X
Ie. II
II II
II
II
_I x'
II x II
II
X
X
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..
.
Subarea
Remedial Actions
Al ternatives
, 2 3 ,
Mine Operations
Area
Remove PCB transformers and PC8-contaminated soils.
x
x
x
x
Repair or remove asbestos materials.
x
x
x
x
Maintain fire controls and inspect structures annually.
x
x
x
x
1~5tituti~l C~trols.
x
1.
x
Move material accumulations and source materials to engineered
repository.
Treat mine water, if discharging, in a CTP.
x
x
x
x
'Reprocess or treat principal threat material accumulations when
appropriate and' relocate remaining materials (such as those in the
Boulevard Area) under the Smelter cap.
x
Treat mine water, if discharging, in collected water wetland following
conventional pretreatment.
x
Clean buildings.
x
x
Channelize and line Bunker Creek.
x
x
Treat Bunker Creek in cOllected water wetland
x
Maintain storm-drainage system and close mill settling pond.
x
x
Install barr;ers consistent with land-use in r~ining areas.
x
x
1.
Treat mine water, if disch~rging, in 2n upgraded CTP O~ new
conve~tional treatme~t plant.
I x
Rights-Of-\Iay
(RO\Is) within
Non-populated
Areas
Temporary dust control on.railroad RO\Is and gravel roads.
x
x
x
x
Enforce existing controls on access.
.x
x
x
x
Hainta;n existing fencing.
Institutional Controls-.
x
x
x
It
x
x
It
Permanent dust control through containment, "hot spot" r.emoval,
soil/rock barriers and revegetation.
x
x
x
Rights-of-llay
(ROU) within
Populated Areas
Temporary dust control on railroad ROUs, gravel roads, and undeveloped
property in residential areas.
x x x
x x x
x x x
x
x
x
Enforce existing controls on access.
Haintain existing fencing.
Institutional Controls.
x
Permanent dust control through containment, soil/rock barriers and
revegetation.
x
During remedial construction, temporary surface sealer application on
roads.
x
Remove exposed source materials and tailings on ROUs-
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'.
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Subarea
Remedial Actions
Alternatives
1 23"
Conmercial
Sui ldings and
Lots
T~rary dust control on conmercial lots and undeveloped property in
residential areas.
II
II
II
II
Institutional Controls.
II
II
II
Revegetate or cover ellposed source materials and tail ings on
cQmmercial lots.
II
II
II
Educational programs to encourage interior cleaning in commercial
bui ldings.
II
II
II
Insti:utional controls ~~ repl6cement of carpe:s, fl~rs, and attic
insulation.
II
II
Jo.
Provide onsite disposal site for soils excavated during future
construction.
II
x
II
Plug ellisting wet Is and provide alternate water supplies.
Institutional 'controls on future development (including measures
mandated in the residential.soils ROD), access restrictions, and
future land use practices. .
II
x
II
II'
II
II
Remove ellposed source materials and tailings on commercial lots.
II
Residential
I nted ors
Continued blood lead monitoring.
x
II
II
x
Provide HEPA vacuum Cle~n~rs for public use.
Educational programs to encourage interior cleaning.
x
x
x'
x
x
x
.X
x
Institutional controls/procedures for normal replacement of carpets,
floors, and attic insulation.
x
x
x
Plug existing wells and provide alternate water supplies. .
x
x
x
One time cleaning of residential interiors after completion of site
wide remedial actions, if interior dust sampling program indicates
that house dust lead concentrations exceed program objectives.
x
II
Carpet removal and replacement after completion of site wide remedial
actions.
II
Future
Development in
Non-populated
Areas
Existing development requirements.
x
Institutional Controls.
x
II
Remediation will occur to address current human health and
environmental concerns.
x
x
II
Remediation activities specific to conditions at future land-use
locations will be implemented, as appropriate, as development occurs;
the remediation activities will be consistent with in.place
institutional controls and intended land use.
x
x
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1.
.
8 COMPARATIVE ANALYSIS OF ALTERNATIVES
A comparative analysis of alternatives using each of the nine evaluation criteria, as required by
the NCP, is presented in this section. These criteria are set forth in Table 8-1. This analysis
has been undertaken in a two-tiered fashion. First, an individual assessment was made o( each
alternative's ability to meet each of nine evaluation criteria delineated in the NCP. Secondly,
a comparative analysis was undertaken to determine the relative performance of the alternatives
and to identify major trade-offs (i.e., the relative advantages and disadvantages) among them.
The purpose of this analysis is to identify the advantages and disadvantages of each alternative
relative to the other alternatives.
8.1 INDIVIDUAL ANALYSES
8.1.1 Alternative 1: No Action
The no action alternative serves as a baseline to evaluate all other alternatives. .While it
incorporates all previous and. planned response actions taken at the Site, the No Action
Alternative fails to fully address contaminant pathways on a site wide.basis. ARAR~and site
wide RAOs established to ensure protectiveness of human health and the environment are not
met. Therefore, the no action alternative fails to satisfy the regulatory threshold requirements
of protection of human health and the environment, and compliance with ARARs. In addition,
tliis alternative fails to utilize permanent and alternative treatment technoJogies,ranks poorly
with regard to long-term effectiveness and permanence in reducing risk, fails to substantially
reduce the toxicity. mobility. or volume of hazar.dous waste associated with the Site, and is not
considered short-term effective. Because it provides a baseline for .comparison,
implementability and .cost are not considered.
8.1.2 Alternative 2: Source and Institutional Controls
The combination of engineering, source, and institutional controls proposed under Alternative
2 achieves the threshold criteria of protectiveness of human. health and the environment. It is .
expected that this alternative would meet .ARARs and RAOs identified for soils and source
materials as well as air. RAOs developed to protect environmental receptors will not be met in
all areas of the Site in the near term; however,as discussed in the Ecological Risk Assessment,
current wide'spread habitat destruction limits actual exposure of environmental receptors to
potentially toxic soil conditions. Seepage reduction and control at the CIA, Page Ponds, and
the Smelter Complex sources are expected to promote significant improvements to Site wide
ground water quality and to substantially achieve ground water RAOs pertaining to onsile
sources over time. Also, loadings reductions to surface water expected under this alternative
would provide significant water quality improvement in' the SFCDR and would substantially
achieve surface water RAGs pertaining to onsite sources. Offsite seeps and
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TABLE 8-1
COMPARATIVE ANALYSIS OF ALTERNATIVES
These are the evaluation aiteria that are required by the NCP to use when comparing the various
cleanup alternatives.
I) Overall protection of human health and the environment: Addresses whether a remedy provides
adequate protection and describes how risks posed through each pathway are eliminated, reduced, or
controlled through treatment, engineering controls, or institutional controls.
2) Compliance with federal and state environmental standards: Addresses whether a remedy will meet
all of the applicable or relevant and appropriate requirements (ARARs) of other federal and state
environmental statutes andfor provide grounds for requ~ting a waiver. '
3) Long-term effectiveness and permanence: Refers to the magnitude of remaining risk and th~ ability of
a remedy to maintain reliable protection of human health and the c=nvironment over time once cleanup
goals have been met.
4) Reduction of toxicity, mobility, and volume: Addresses the anticipated performance 'of the' treatment
technologies that may be employed ina remedy" in terms ,of eliminating or controlling risks posed by
the toxicity, mobility, or volume 'of hazardous substances.
5) Short-term effectiveness: Refers to the speed with which the remedy achieves protection. as'well as
the remedy's potential. to create adverse impacts on human health and the environment during the
construction and implementation period.
6; Implement2bility: Addresses the !c:chni~i and administrdtiv~ feasibility of a remedy including the I
availability, of rru£lerials aad services needed to' implement' the chosen solution.
7} Cost: Includes capital costs; operating and maintenance (O&M) costs (including Institutional
Controls), and evaluates the cost-effectiveness of each alternative."
8) Slate acceptance: Indicates whether the !:tate concurs with, oppo~, or has no comment on the
preferred alternative.
9) Community acceptance: Assessed following a review of public comments, both ol"'.il and written,
received on the RifFS and supporting technical memoranda documents.
loadings and the widespread existence of jig tailings onsite may inhibit immediate compliance
with cenain ground water ARARs in some areas of main valley aquifer. Ultimate attainment
of Federal Water Quality Criteria (FWQc) in the SFCDR, and Maximum Contaminant Level
(MCL) and Maximum Contaminant Level Goals (MCLGs) promulgated under the Safe
Drinking Water Act (SDW A) in portions of the valley aquifer system, will depend on the
implementation and effectiveness of o(fsite programs to reduce or control contaminant transport
and on the ability of onsite remedies to meet performance standards over time. Separate
offsite programs to restore the Coeur d' Alene River Basin are currently being formulated by a
multi-disciplinary group of Federal, State, Tribal, and local governments in an effort to
coordinate programs to restore water quality in the Basin to its maximum beneficial use.
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A contingent waiver for chemical-specific ARARs within the main valley aquifer'system will
be granted only after technical impracticability has been demonstrated, consistent with the'
procedure outlined in Section 10 of this ROD: All alternatives will rely on institutional control
of water use to be adequately protective of human health. Five year reviews will be'relied
upon to evaluate the effectiveness of the selected remedy and compliance with ARARs.
The overall long-term effectiveness of Alternative 2 is rated moderate based on the degree to
which site wide RAOs are addressed, the degree to which the Principal Threats are reduced,
the reduction of risks to humans, and the need to rely on long-term institutional controls to
achieve protectiveness for contaminants remaining onsite. Because Alternative 2 does not
propose treatment of Principal Threat materials, it does not meet the statutory preference for
remedial actions that employ treatment technologies that significantly reduce the toxicity,
mobility, or volume of hazardous waste. However, the removal and on site containment of
source materials contemplated under Alternative 2 would substantially decrease the magnitude
of residual risk and provide long-:term effectiveness by decreasing the volume of uncontrolled
waste sources which can. contribute to exposure pathways of concern. Capping and cover
requirements contemplated under this 'alternative would also contribute to a reduction in "
mobility of contaminants of concern.
Alternative 2 is readily implementable and would not result in excessive risk to workers or the
community, if properly implemented; therefore, it is considered short-term effective. Total
capitaIcosts are estimated to be $31.3 million, while O&M costs are estimated at $11.5
million. Total costs are significantly less .than costs for Alternatives 3 and 4; but, the
alternative does not provide comparable site wide improvements. .
8.1.3. Alternative 3: Source Controls and Treatment
By combining containment, treatment, and institutional controls, Alternative 3 addresses all
onsite pathways and is p:-otective of human health and the environment onsite. In addition, it
effectively contributes to improvements in downstre<\.m water quality. This alternative provides
a high level of protectiveness, would minimize exposure pathways identified for soils, source'
material, and air, and would attain soil and air RAOs site wide for human health protection.
RAOs developed to protect environmental receptors will not be met in all areas of the site in
the near term; however, as discussed in the Ecological Risk Assessment, current wide-spread
habitat destruction limits actual exposure of environmental receptors to potentially toxic soil
conditions. As habitatonsite is re-established environmental receptors will be monitored to
evaluate potential impacts. Actions specified in Alternative 3 are expected to have significant
water quality benefits, limit direct exposure to the most contaminated soils onsite, and re-
establish vegetative cover over exposed areas of the Site. Although FWQC in the SFCDR are
not expected to be met in the near term, Alternative 3 adequately controls onsite sources to
the river and substantially improves water quality and aquatic conditions both on and down
gradient of the Site. Most Site-wide surface and ground water RAOs are expected to be met
under this alternative. However, ~ertain chemical-specific ground water ARARs in the main
valley aquifer may not be achieved by' onsiteremedial actions.
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8.1.4 Alternative 4: Removal, Source Controls, and Treatment
Alternative 4 addresses all pathways and is protective of human health and the environment.
Site wide RAGs and ARARs for soils/source materials and air would be met for human health
. protection. RAGs developed to protect environmental receptors will not be met in all areas of
the Site in the near term; however, as discussed in the Ecological Risk Assessment, current
wide spread habitat destruction limits actual exposure of environmental receptors to potentially
toxic soil conditions. Although ground water ARARs in the valley aquifer system and FWQC
in the SFCDR are not expected to be met in the near term, Alternative 4 adequately controls
these pathways on site and would substantially improve water quality and aquatic conditions
both on site and down gradient of the Site, thus providing the iargest practicable improvement
in water quality and aquatic conditions of the four alternatives. It relies to a moderate degree
on institutional controls to eliminate or reduce ground water and surface water exposures and
to ensure the long-term reliability and. effectiveness of other treatment and source control
measures.
Most .Site wide ground water and surface water RAGs are. expected to be met under this
alternative. However, as was noted in Alternatives 2 'and 3 specific conditions for a contingent
. ARAR waiver in the main'valley aquifer are outlined in Section 10. Altemative.4 is expected
to be more successful in achieving ARARS onsite than Alternative 2, as it is more.effective in
controlling sources of ground water and surface water contamination. Action specific ARARs '. .
and ARARs for air, soil/source materials will be achieved. .
The overall long-term effectiveness of this alternative is expected to be high based 'on the.
degree to which it addresses Site-wide RAOsand on the. permanence and reliability of the. .
prescribed controls. However, this effectiveness is tempered by the generation of potentially
hazardous water treatment sludges over an indefinite time period. RAOs would be addressed .
and Principal Threats in soil and source material reduced through reliance on removal, .
containment and conventional water treatment. Loading reductions to ground water, surface
water, and air would also be realized. A.!t~rnative 4 would significantly reduce the mobility of
contaminants across the Site; however, only proposed water treatment remedial actions result.
in a reduction of volume or toxicity of contaminants. .
Due to its reliance on extensive removal actions, Alternative 4 presents a higher level of
potential human health and environmental risks and thereby negatively influences short-term
effectiveness. These risks can be minimized by appropriate controls, but would require more
intensive management compared to other alternatives.
lmplementability of this alternative is considered readily feasible based on its utilization of
standard technologies. However, implementability concerns do exist because of the large
scale removal to be undertaken. Total capital costs are estimated at $90.2 million, while O&M
COStS are estimated at $87.9 million.
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8.2 COMPARATIVE ANALYSIS
The subsequent sections summarize a comparative analysis of each of the nine evaluation
criteria (fable 8-1) to determine the relative performance of the alternatives and identify major
trade-offs. .
8.2.1 Protection of Human Health and Environment
Alternatives 3 and 4 provide superior site wide protection relative to Alternative 2, which
provides 'a relatively large increase in protectiveness over Alternative l. Specifically,
Alternative 2, 3, 2nd 4 would all be protective with regard to soil, source, and air pathways.
Alternative 2, however, provides adequate, but comparatively less, protection and improvement
of ground and surface water pathways than Alternatives 3 and 4 as it relies more heavily on
institutional controls to control potential exposure pathways. Alternatives 3 and. 4 provide
comparable net improvementS and protectiveness site wide. . All alternatives . rely to various
degrees on i~stitutionaJ controls to be protective of Human Health & the Environment both in .
the near and long term. .
8.2.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Alternatives 2, 3, and 4 meet ARARs identified. for soils, source materiaJs, and air as well as
action specific ARARs. Whether or not any of the alternatives. would meet groundwater'
ARARs throughout the main valley aquifer is uncertain.. . Contamination attributable to
dispersed and largely inaccessible jig tailings throughout the river valley may make attainment
of certain of these ARARs impracticable. Section 10 includes.a discussion. of the basis for
making the technically impracticability determination and waiving chemical-specific ARARs in
areas of main valley aquifer system continuing to exceed ARARs. after successful
implementation of the remedy and contingent measures. Institutional controls w.ill continue to
protect against utilization of the aquifer umil all Drinking Water Standards are met.
With respect to the attainment of FWQC in site surface water, these ARARs are expected to be
achieved in onsite tributaries to the SFCDR upon the successful implementation of remedial
actions specified in this ROD. The attainment of FWQC in the SFCDR has been determined
to be beyond the scope of this ROD and is therefore not an ARAR for this action. Protection
of the SFCDR from FWQC exceedances due to onsitesources, however, continues to be an
objective of the remedial actions in this ROD. U.S.. EPA is currently working with State,
Tribal, and local government, as well as other federal agencies and ]ocalinterest groups to
develop and implement cleanup strategies Jor the Coeur d'Alene Basin which are expected to
significantly improve water quality conditions both upstream and downstream of the Site.
Five year reviews will be relied upon to evaluate the effectiveness of the selected remedy and
compliance with ARARs. . .
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RCRA LDRs (40 CF:R 268) are not applicable to the utilization of cement-based stabilization
of Principal Threat wastes in Alternative 3, since LDRs for mineral processing wastes are not
scheduled for promulgation until 1994. However, for the purposes of this . action, percent. ,
reduction and/or extract concentration criteria goals of the LDRs will be considered. to be
relevant and appropriate for this treatment component of the remedial action. Treated
Principal Threat waste would be consolidated within the Smelter Complex.
8.2.3 Long- Tenn Effectiveness
Alternatives 2, 3, and 4 are all effective and reliable remedies with respect to riskS and
conditions assodatcri with onsite sources. However, Alternatives 3 and 4 provide additional
improvements through treatment of surface and ground water. The treatment plant proposed in
Alternative 4 would require. more long-term maintenance than that anticipated under
Alternative 3. This may affect effectiveness in the long-run.
In addition, Alternative 3 provides enhanced effectiveness relative to other Alternatives through
treatment of Principal Threat wastes. . The removal of all accessible jig taHings in Alternative
4 would increase the long-term effectiveness compared'to Alternative 3. Alternative 3, utilizes
institutional controls and the constructed wetland ground water system to mitigate the iinpa~ts
of this contaminant source.
8.2.4 Reduction of Toxicity" Mobility, Volume, and Persistence through. Treatment;
Other than treatment actions for sediment reduction in tributary sedimentati,on basins"
Alternative 2 -does not incorporate treatment as a component of;, the remedy . It therefore
compares poorly with respect to the statutory mandate for treatment. Alternatives 3 and 4
utilize treatment of ground and surface water to the same extent; ,and, b
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8.2.6 Implementability, Reliability, and Constroctability
Alternatives 2, 3, and 4 are implementable using standard construction/remediation techniques. .
Long term monitoring efforts under Alternatives 2 and 3 may be greater than for Alternative 4.
Alternative 4 would involve a sizable loss of developable land along the 1-90 corridor due to
extensive tailings excavation in Smelterville Flats and would necessitate obtaining onsite or
near offsite landfill space to handle a continuing stream of treatment sludge generated by the
water treatment plant.
8.2.7 Cost
A summary of estimated capital, 0 & M, and net present worth costs is provided in Table 8-2.
Alternative 2 is significantly lower in capital and net present worth costs, but is also lower in
overall long-term effectiveness. Although Alternative 3 is significantly lower in costs than
Alternative 4, it provides comparable net protection and provides substantial improvements due
to innovative surface and ground water treatment methods and the utilization of
reprocessing/recycling technologies.
8.2.8 State Acceptance
IDHW.and U.S. EPA have worked together throughout the developmeni of the Bunker Hill.
Superfund project. The State of Idaho concurs with the selection of Alternative 3 as the
remedial action for the Site.
8.2.9 Community Acceptance
The results of the public comment period and the discussion during the Proposed Plan Public
Meeting indicate that the majority of the community supports the proposed alternative. . The
community expressed overwhelming desire to get the cleanup moving as soon as possible; See
the Responsiveness Summary for additional details of community response.
8.2.10 Tribal Acceptance
The Coeur d' Alene Tribe has been participating in the Site activities since 1990. The Coeur
d'Alene Tribe in their letter of August 1992, to U.S. EPA continues to express concern with
the Proposed Plan for the Site. These concerns are addressed in the-Responsiveness Summary
Section. .
Individual concerns about various aspects of th~ Proposed Plan are responded to -in the attached
Responsiveness Su m mary.-
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TABLE 8-2
SUMMARY OF COSTS ...
Alternalive Capital O&M Total Present Worth COSI
Number Cost Cost Cost (5 % discount rate)
I $ $ $ $
2 $31,218,000 $11,547,000 S42.825,OOO $31,549,000.
3 $56,571,000 $11,096,000 $67,667,000 S52,035,ooo
4 $99,589,000 S87,929,OOO ~187,518.000 $120,291,000
... Costs do not include the COsl of hillside work currenlly ongoing, the cosi of additional planting .in
the 50 - 85 % cover class on the hillside. and costs to remediaie ROW. commercial buildings and lotS.
and residential interiors. However. costs do include demolition of the zinc plant and lead smeller tall
stacks. which are nOI requirc:d by this ROD. The eslimaled costs for stack demplition are expected to
be adequate to cover the majority of the costs nOI included in this.tab1e. The overdll cost for the
Remedial Action is consistent with the: cosl estimaling guidelines in U.S. EPA RIIFS'Guidance.
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9. THE SELECTED REMEDY
9. I INTRODUCTION
u.s. EPA and IDHW have'selected Alternative 3 for cleanup of the Bunker Hill Superfund
Site. This selection is based on the Administrative Record for the Site. These actions.
coupled with actions required in the Residential Soils ROD and U.S. EPA directed response
, actions, constitute the Site wide remedial actions selected by the U.S. EPA and IDHW. The
remedial actions are developed to address the subareas RAOs as well as media-specific
concerns in that subarea. '
9.2 REMEDIAL ACTIONS BY SUBAREAS
Remedial actions specified below were presented in Table 7-1 ; however, this section provides
a more thorough discussion of the selected remedy and includes performance standards for
remedial actions where appropriate. The discussion is presented in the following sections: .
. Hillsides
. Smelterville Flats
. Central Impoundment Area (CIA)
. Page Pond
. Smelter Complex and Mine Operations Area
. ' Rights-of-Way (ROW) .
. Commercial Buildings and Lots
. Residential Interiors
. Future Development in Non-populated Areas
. Constructed Wetland Treatment Systems
. Public Water Supply Considerations
. Soil Action Levels
. Operation and Maintenance
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. Institutional Controls
. Monitoring
. General Remedial Design Considerations
9.2.1
Hillside Remedial Actions
U.S. EPA is currently overseeing implementation of an Administrative Order on Consent
(ACC) for Revegetation and Stabilization of hillside areas within the Site. This AGC was
signed in October, 1990 by U.S. EPA, Gulf Resources & Chemical Co. and Hecla Mining.
The .AGC calls for the revegetation of 3,200 acres of eroding hillsides having less than 50%
cover within the Site. contour terracing of steep slopes to control erosion and increase
infiltration, erosion control and sedimentation retention structures, and control of Water and
wind erosion of selected mine dumps.. U.S. EP A approved workplan for Hillsides Stabilization
and Revegetation provide for achievement of 85 % ground cover on existing barren hillsides.
within approximately 8 to 12 years. ..
Zero gradient. contour terraces. are being constructed on the selected barren. and sparsely. .
vegetated hillside to the south, east, and west of the Smelter Complex. Sediment retention
treatment basins are being constructed in the.major tributaries within 'the Smelter Complex area.
for the purpose of reducing the suspended sediment/contaminant loadings in surface runoff. to .
the SFCDR. These detention structures receive £torm flows from Deadwood, Magnet. and.
Government Gulches. Additional details of the work to be. performed are found in the AOe
work plan which is available in the Administrative. Record repository at the Kellogg library..
In addition to the revegetation actions specified on approximately'3200 acres in the Hillsides
AOC workplan, U .5. EPA is requiring that severely eroding hillside areas having less than
50% cover, within areas of greater cover (50% +), are also revegetated consistent with the
methodology outlined in the AOC.. . The revegetation efforts apply to areas where there is a
high potential for contaminant transport and the net impact of planting access is not greater
than the .benefit. Specific areas to be added to the revegetation efforts will be determined by
additional field investigations conducted during the Remedial Design phase; however, the
additional acreage is expected to be less than 500 acres. Additional emphasis is also placed on
re-establishment of riparian habitatand stream corridor vegetation under this action, although
establishment of runoff filtering areas adjacent to stream corridors and drainage ways is an
integral component of the Hillsides ACe. In general, efforts will be undertaken to establish a
vegetated stream corridor of 100 feet width at a minimum. Specitic plans for each stream
corridor beingremediated will be developed during Remedial Design in conjunction with
development of Hillsides ACe workplans. Respondents to the AOe have established Test.
Plots to determine which revegetation strategies will be most effective on the hillside areas.
The results of the test plots will be used to determine the best revegetation applications.
Monitoring of the performance and maintenance of erosion control measures and sedimentation
structures will continue until revegetation efforts have been successful in controlling erosion
and sedimentation of the hillside areas. Future work will be consistent with action taken to
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date in accordance with the October 1990 AOC. Detailed design and construction documents
for hillside actions have been prepared as required by the AOC and are available for review in
the Administrative Record. Also included in the AOC work plans are'site specific plans for
.closure of mine rock dumps identified as posing a direct contact or erosion hazard. "
In order to minimize contact betw~n Milo Creek surface water and tailings and mine waste
rock on the Milo Gulch floor, and reduce contaminant transport to the SFCOR as suspended
sediment during runoff events, Milo Creek will be' channelized and lined from the Wardner
Water System intake to the culvert which directs stream flow beneath Wardner and Kellogg.
Lining of Milo Creek may also reduce recharge to the Bunker Hill Mine workings.
Operation and Management plans will be developed during remedial design for ali hillside
actions in order to assure continued effectiveness.
9.2.2 Smelterville Flats
Remedial actions for Smelterville Flats consist of actions to control migration, of windblown
dust, minimize direct contact risk" and control contaminant migration to surface and, ground
water. Consistent with other, remedial actions to treat contaminated surface and ground water
at the Site, over 100 acres of jig tailings-contaminated alluv.ium will, be rem'O}/ed from the', ,
northwestel11 portion of the flats adjacent to the SECOR' for, the creation of'. constructed,',
wetlands for the treatment of surface and ground water.; this material will be 'consolidated in'
the CIA. Additional details on' the conceptual design of this system' are ,provided in the
Constructed Wetland Technical Memorandum available', at the Administrative 'Rec.ord
repository. ' ,
Along with the construction of the wetlands, a flood way with a' protective dike. will he' ' ,
constructed on the south side of the SFCDR. 'The 'floodway will be a minimu'ffi of SOO f~t'
wide and the dike will be designed to protect Smelterville Flats and, the wetlands treatment'
system from a 100 'year, 2.4 hour storm event. Accessible tailings in those portions of the
floodplain of the SFCDR being modified for flood way construction will also be removed and
disposed of in the CIA. Additionally, all exposed' tailIngs ,along ,the banks of,the SF-COR
within the Site will be stabilized to prevent erosion; or removed for consoiidation within the
CIA. Remedial design for any modificatioris within the floodway, and all bank stabilization
measures, will incorporate aquatic habitat considerations. Appropriate State and, Federal
natural resource agencies will be consulted in developing site specific habitat considerations.
For example, stream corridor configuration and revegetation of river banks can be designed to
maximize benefits to aquatic resources.
Implementation of these measures will result in improvements to ground water and surface,
water quality due to the removal of these materials to an area that will' be reSiSlar.ll to
intiltration and isolated from contact with ground water and surface water.
The jig tailings/alluvium mixture that will remain in Smelterville Flats will be capped with a
minimum of six inches of soil to enhance revegetation efforts and minimize direct contact risk.
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Alternatively, contaminated surfaces will be covered with a more permanent barrier, consistent
with current land use (revegetation is the preferred remedial action and will be required unless
land use necessitates a more durable barrier). As with other areas of the Site, if land use
conversions occur in Smelterville FlatS a barrier consistent with the new land' use will be
required in those locations where lead concentrations in the top foot of soil.exceeds 1,000.
ppm. This cleanup goal is consistent with the remedial action level in the Residential Soil
ROD. An institutional controls system will be the mechanism used to ensure that appropriate
barriers are installed and maintained on Smelterville FlatS as land use conversions occur.
Approximately 500 acres of Smelterville FiatS will be removed or capped. Jig
tailings/alluvium removed from Smelterville FiatS will be placed in the CIA prior to its
closure.
Additional remedial actions specified for Smelterville FlatS include a system for capturing and
treating ground water being discharged to the SFCDR in L'te areas immediately..east of
Pinehurst Narrows. This system is discussed in greater detail in section 9.2.10 - Constructed
Wetlands Treatment System. .
9.2.3 Central Impoundment Area
The remedial actions proposed for the CIA focus on minimizing releases from this source b:y
installation of a cap designed to minimize infiltration through jig tailings and Central Treatment.. .
. Plant sludges disposed of in this area. The CIA will also serve: as a repository for
consolidation of jig tailings/alluvium, gypsum .and slag remo.ved as a component of other
remedial actions. The cap will be designed to have a hydraulic conductivity of less than, 10-6 .
em/sec. After grading of the CIA surfac.e and dikes' to promote runoff.. the cap will be
composed of a minimum of twelve inches of low permeability material overlain by a minimum
of six inches of clean soil suitable for revegetation. Other engineering designs meeting these
criteria will be considered. Cap design and revegetation requirements will be consiStent with
potential future land use. Prior. to closure of the CIA, material accumulations originating from
the 1982 Smelter Complex cleanup will be removed and returned to the Smelter Complex.. A
d~termination will be made regarding whether the material will be recycled, reprocessed, or
treated via cement based stabilization prior to being capped in the Smelter Closure. The'
process for making this determination is detailed in Figure 9-1. Surficial soils on the. CIA. .
dikes and areas surrounding the CIA will be capped, as appropriate, consistent with. current
land use. At a minimum,six inches of clean soil will be placed to enhance revegetation. The
slag pile on the west end of the CIA will be relocated either to the Smelter Complex or the
east cell of the CIA prior to capping.
Included in the CIA closure is installation of a system to recover and treat contaminated
ground water surfacing north of the CIA. This recovery system will be designed to maximize
the efficient interception of contaminated ground water from the "CIA Seeps". Water collected
from the seeps will be conveyed to the constructed wetlands treatment system before release to
the SFCDR. . The performance standards for the constructed wetland treatment system are
discussed in section 9.2.10.
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9.2.4
Page Pond
Page Pond is a former tailings disposal area resulting from mineral mining and concentrating
activities at the former Page Mine. This area contains tailings that contribute to localized
contamination of surface and ground water and serves' as a source of windblown dust. The
Page Pond currently serves as a repository for soils removed from residential properties as
well as the site for the South Fork Sewer District Water Treatment Plant. The remedy for
Page Ponds calls for the removal of approximately 40-60 thousand cubic yards of jig tailings
accumulations from the West Page Swamp area and the subsequent placement of this material
on the Page Pond benches as a sub-base for a vegetated cap. The final extent of material ~o be
removed from West Page Swamp will be determined during Remedial Design and will considc::r
current vegetated status, surficial soil contaminant concentrations, water levels, and habitat.
The regrading and capping of Page Tailings Impoundment with residential soils will serve as a
barrier to direct contact with tailings within this impoundment and will facilitate revegetation
efforts in that area. In addition, the cap will decrease the leachate generation of the' Page Pond
area by' promoting runoff' and evapotranspiration compared, to current conditions.
Impoundment dikes will also be regraded and then vegetated after placem'ent of a minimum of
, six inches of clean soil. Existing fencing will be maintained to limit access. Wetlands
associated .with the Page Pond areas will be evaluated for water quality, habitat considerations;-
and biomonitoring in order to assess environmental conditions resulting from remedial 'actions. '
U.S. EPA and IDHW will work with the appropriate state and federal natural 'resource
management agencies to determine appropriate management and operations of the area.
Under this alternative Humboldt and Grouse Creeks will be isolated, tathe degree practicable,
from contact with Page tailings accumulations by the' use of diversions and channel
modifications. The objective is to minimize the contamination of these surface streams by
preventing contact with jig tailings. Some benefits' will also accrue to grourid water as the
diversions can be designed to minimize surface water contributions to the ground water system, .
underlying Page Ponds. Final configurations of any channel modifications will be determined
, ,during Remedial Design and will include habitat considerations. Appropriate State and Federal
natural resource management agencies will be consulted in determining the most appropriate
design. ' '
9.2.5
Smelter Complex and Mine Operations Area (MOA)
The Smelter Complex and Mine Operations Area include those areas of the Site that comprise
the former active mining, milling, and material processing areas of the Site. This area
typically contains the most highly contaminated areas of the Site with metal concentrations of
material accumulations and soils well into the percentage range'in many instances. The
Remedial Investigation (RI) Repon includes summary tables documenting material
accumulations found within the Smelter Complex and MOA. In addition to material
accumulations, the Smelter Complex and MOA contain numerous contaminated struclllres in an .
advanced state of deterioration, The Smelter Complex and MOA present a continuing threat to
the community due to the risk of Ii re and the threats posed to trespassers on the property,
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the community due to the risk of fire and the threats posed to trespassers on the property.
Contaminant migration via wind and water' is also a major concern. Acid mine drainage from
the Reed and Kellogg tunnels or other mine portals where the drainage from the Bunker Hill
Mine is collected will also require collection and treatment. .
Remedial actions selected for the Smelter Complex and MOA focus on limiting direct contact
with contaminants and controlling migration of contaminants to surface and ground water.
Following removal and reprocessing, recycling, or cement-based stabilization of Principal
Threat (threshold concentrations provided in the table below) material accumulations and soils
within the Smelter Complex and MOA, the Lead Smelter and the Zinc Plant structures will be
demolished in place and prepared for capping after removal of salvageable items, such as steel,
timber, and equipment. Salvage material will be decontaminated consistent with the proposed
rule for Best Demonstrated Available Technology (BDA T) treatment technologies for
contaminated debris published in the Federal Register, January 9, 1992. Recycling and
reprocessing of material accumulations and demolition debris will be utilized to .the extent
practicable in order to minimize material in the Smelter closure. MOA structures will be
decontaminated consistent with intended use. and maintained for future utilization, where
feasible, or demolished. Prior to demolition,PCB-containing equipment':wilI. be managed
consistent with applicable Toxic Substance Control Act (TSCA) regulations. Asbestos
containing materials will also be. managed consistent with applicable regulations during all
closure activities. Demolition of the Lead and Zinc tall stacks are not required as pan of this
action; however, they must be decontaminated. .
. The Smelter Complex is composed of three principal -areas for the purpose' of this discussion;.
the Lead Smelter, Zinc Plant, and Mine Operations Area. .Associated material storage si.tes .
and related areas are also considered part of the Smelter Complex. The following discussion
focuses on these three principal areas. Materials accumulation 'sites and associated soils that
have been impacted by contamination from mineral processing facilities (e.g.. lead 'smelting,
zinc refining, etc.) are slated for removal and consolidation within the Lead Smelter and Zinc
Plant closures since these wastes are generally of higher concentration and require a greater
level of management in order to insure a protective remedy. A subset .of these materials'
comprises the Principal Threat materials of the Site. The parameters of this subset are outlined
in a separate. Principal Threat Technical Memorandum which 'is pan of the Administrative
Record for the Site. Table 9-1 lists the ac£ion levels for the Principal Threat materials.
Principal Threat materials will be reprocessed, recycled, or treated via cement-based
stabilization under this remedial action to address the statutory preference for treatment of
Principal Threat Wastes (Figure 9-1). .
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Figure 9-1
Material Accumulation flow Chart
MATERIAL ACCUMULATION
.'
" '. .
RECYCLE OR REPROCESS
'if 1
~ I
I NO
,
I OFF~ITE I
PRINCIPAL THREAT
,. 1r
YES-Treat NO-Under Cap
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I TABLE 9-1 I
Principal Threat Action Levels.
Metal ppm Percent
Antimony 127,000 12.7%
Arsenic 15,000 1.5%
Cadmium 7i,OOO 7.1 %
Lead 84,600 8.5%
Mercury 33,000 3.3%
. Material accumulations or soils are considered to be Principal Threat Wastes if th~ concenmttion of any.
constitu~nts exceeds the levels.
Lead Smelter
. Other materials within the Smelter Complex to be consolidated in the Lead Smel.ter closure
include:
. contaminated materials and soils from the "boneyard area" south of the.
Lead Smelter;
. some slag from the west cell of the CIA to aid in preparation of the Site
for the final cap; .
.
residential soils collected during other remedial actions may be
consolidated within the smelter closure as needed to facilitate preparation
of the Site for capping and revegetation;
. Smelter Complex cleanout material (removed from the Smelter Complex
by Gulf in 1982) currently located in the CIA, approximalely 31,000
cubic yards;
. material removed within the MOA during remediation of thaI area,
including the "boulevard area";
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treatment in the constructec;! wetland treatment system to be located in Smelterville Flats.
During remedial design the adequacy of the existing CTP to pretreat mine water. will be
evaluated to determine if modifications to this facility are needed to meet water-quality-based
effluent limits which will be imposed on the constructed wetland treatment system outfall.
This remedial action is consistent with the requirements of a U.S. EPA Administrative Order.
issued in 1991. The order requires that a closure plan for the Bunker Hill Mine be developed
and implemented which addresses acid mine drainage from the mine as well as other
environmental considerations.
Closure Considerations
Upon demolition of the Lead Smelter and Zinc Plant, and consolidation of material
accumulations and contaminated soBs, including treated Principal Threat materials, both of
these facilities will be closed. The Principal Threat materials remaining after recycling and
reprocessing options have been implemented: will be' treated via cement-based stabilization
fixation.
The objective .of cement-based stabilization/fixation is to reduce the mobility of contaminants. .
Relevant and appropriate requirements of RCRA. Land Disposal Restrictions (LDRs) for
cement-based stabilization of Principal Threat waste are expected' to be. attained... While LDRs
for mineral processing wastes have not been promulgated (and therefore are not applicable),.. .
U.S. EPA has determined that it is appropriate to achieve the percent reduction and/or extract
concentration criteria goals set forth in the LDRs for immobilization of inorganic compounds.
Treatability tests for cement-based s()lidificaticn of one of the major' Principal Threat. waste..
material accumulations onsite (the Cop~r Dross Flue DUSl' recently moved from Magnet Gulch
to the Smelter Complex) indicates that attainment of percent reduction .goals based upon TCLP
protocols is likely. However, due to the varying solubilities. of contaminants of concern .
through a range of pH'values, U.S. EPA has determined that the acid leaching aspects of the
TCLP test protocol are not . appropriate for wastes consolidated in the Lead'Smelter Closure.
and has elected to design a stabilization mixture that will achieve LOR percent reduction goals
and/or extract concentration criteria at a pH reflective. of actual onsite conditions. A rain
water leach test which approximates.onsite conditions has been determined to be.appropriate;
a modification of U.S. EPA Method 1320 will be used. Treated Principal Threat materials
will be consolidated in concrete substructures (basements, storage bins, etc.) within the Lead
Smelter Complex unless other areas are determined to be appropriate by U.S. EPA during
Remedial Design.
Closure of the Lead Smelter and Zinc Plant will consist of a minimum of one foot of low
permeability material or a soil/geosynthetic cap (or an appropriate combination of the two) that
will have an in place hydraulic conductivityof less than or equal to 10.7 cm/sec to minimize
water infiltration and subseql.1ent contaminant migration. Other appropriate RCRA 40. CFR
Part 264, Subpart G requirements for closure of existing facilities will be incorporated into the
closure design, including: leachate collection and treatment, runoff and runon controls,
.monitoring, and operation and maintenance considerations.
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. material accumulations and contaminated soils, including former waste
disposal or holding ponds sediments within the Smelter Complex; . .
. cleanup material from MOA buildings decontaminated to allow for future.
industrial utilization; . .
. Magnet Gulch cleanup material accumulations and contaminated soils;
. treated Principal Threat material, including the Copper Dross Flue Dust
Pile which was recently removed from Magnet Gulch for temporary
storage in the Lead Smelter Complex where it awaits cement based
stabilization; and,
. other materials/soils determined during Remedial Design lobe.
appropriate to consolidate in this area.
Zinc Plant
The Zinc Plant closure will. include material from the Zinc Plant; Phosphori.c Acid/Fertilizer
Plant areas (excluding the fertilizer warehouse),.. contaminated soils in the vicinity of the. Zinc
Plant and upper Government Gulch, and material, debris, and contaminated soils . from the
fertilizer plant. Any of the materials destined for the Zinc Plant closure could also be placed .
'in the Lead Smelter Closure if the Zinc Plant closure is at capacity.
Mine Operations Area
Surface soils and material accumulations within the MOA will' either be removed for
consolidation within the lead smelter closure,. treated as Principal.. Th~~t . wastes. and
consolidated within the lead smelter closure, or capped in place with a barrier consistent with
land use. Remooiation of the MOA is 'expected to include considerable removal. of material.
due to high levels of contamination found in this area and the anticipated future'land.use. In'
determining whether soils in the MOA and Smelter Complex (outside of the capped area) 'are'
removed to be consolidated in the Lead Smelter and Zinc Plant closures, an evaluation of,the.
characteristics of material accumulations will be conducted during Remedial Design. . All
material accumulations and associated soils will be removed and consolidated in the Lead or
Zinc Plant closures if they exhibit concentrations in ex.cess ofwlJat would typically be .
attributed to mine waste rock or tailings. Remedial Design will include a process for
determining the extent of excavation in areas impacted by material accumulations. In all cases.
a minimum of six inches of clean sailor other barrier appropriate to .land use, will be applied
as a cover where surface concentrations exceed 1,000 ppm lead.
Currently, a portion of the acid mine drainage from the Bunker Hill Mine is conveyed from
the Kellogg Tunnel to the CIA for subsequent treatment in lhe Central Treatment Plant (CTP).
All acid mine drainage will be conveyed to the CTP for pre-treatment followed by further
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will receive one or more of the following treatments: access control, capping (i.e., barrier
consistent with land use), or removal/replacement. Capping will be the predominant action
utilized in Non-populated Areas; however, in areaS within the Smelter Complex/MOA removal
and replacement will be favored. Where caps are determined to be appropriate during RD,
they will be consistent with land use and will have suitable durability; for example, in the case
of overhead power lines the method of remediation will be consistent with the other areas
around the ROW. Within residential areas, ROWs adjacent to residential properties will be
treated consistent with the remedial action selected in the Residential Soils ROD. In a11 cases,
ROWs contributing to contaminant migration via air or water will be addressed. ROWs
include a11 state, cOunty, local and private roads.
9.2.7 Commercial Buildings and Lots
Commercial buildings and lots include public buildings, parks, churches, as. well as
.commercial properties. Risks posed by commercial buildings and lots. are similar to those in
residential settings. While the duration ~f exposure in commercial settings may be less, on the
average, than a residential setting, the most sensitive portion of the population must still be
protected. Consequently, this action requires remedial actions similar to those for residential
areas. In existing commercial settings soils exceeding a lead concentration of 1,000 ppm in the
top. I foot, must receive a protective barrier consistent with land use. Barriers. may include a
minimum of six inches of clean soils or gravel, or.a paved" surface. Final decisions regarding
barriers performance standards .will be developed during Remedial Design or as a component
of the institutional control program. Commercial properties used predominantly by sensitive
. populations wili require a 12 inch soil barrier. As new commercial uses are undertaken the
same approach .to barrier management wil1 be required. The institutional control program
planned for the Site will provide specific performance standards for various barrier systems. .
Proper disposal of material excavated during commercial development is a key component of
this remedy; Soils. may be consolidated within the Page Pond tailings impoundment, or the
Smelter Complex, until closure of Smelter Complex is complete. .
With respect to interiors of commercial properties, the institutional controls program will
encourage interior cleaning of propenies and provide guidelines for replacement of carpets,
floors, and insulation of existing structures.
9.2.8 Residentiallnteriors
The remedial actions presented here are intended to complement actions selected in the
Residential Soils ROD issued by U.S. EPA in August of 1991. To provide a protective
remedy for Site residents the following components are included: .
. Continuation of blood lead monitoring in conjunction with educational
programs currently provided by the Panhandle Health District.
. Continuation of the high efficiency vacuum loan program.
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Other Smelter Complex Remedial Actions
The surface water actions selected for the Smelter Complex include channelizing and lining of
Government Creek, with. diversion and treatment. of base flows in the Collected Water
Wetland. A cutoff wall will be constructed south of the Zinc Plant in order to divert relatively
uncontaminated water around the closed industrial complex. A second cutoff wall will be
. constructed at the northern end of the gulch to faci~itate the collection of contaminated ground
water and surface water within the area. This water will be shunted to the constructed wetland
treat.ment system planned for Smelterville Flats under this alternative. The Remedial Design
for these components of the remedial action will seek to maximize recovery of base flow
contaminated ground water and surface water for treatment and divert uncontaminated surface
. water and ground water around. the closed industrial complex to the SFCDR. Bunker Creek
base flows will also be conveyed to the wetland treatment systems if water quality sampling
indicates exceedances of FWQC.
The existing storm water drainage system in the MOA will be maintained and the mill settling
pOnd (Concentrator Reservoir) will be closed. Any sludge remaining in the bottom of the mill
settling pond will be consolidated in the Lead Smelter closure.
The A-I Gypsum Pond sediments located in Magnet Gulch will be removed and relocated to
the CIA prior to closure of that .area. The. A-4 Gypsum Pond sediments, located north of
McKinley Avenue at the mouth of Magnet Gulch, will either be capped in place or moved to
the CIA along with the A-I Gypsum Pond. The final determination regarding this aspect of
the selecte-.d remedy will be based upon the engineering feasibiiity of closing the A-4 Gypsum
Pond in place and additional consideration of ground water and surface water hydrology in that
area. If a cap is selected it must minimize infiltration through the A-4 Gypsum Pond and. be of
low maintenance. Relocation the A-4 Gypsum Pond sediments within the CIA closure would
have the additional benefit cif making an area available in the former A-4 Gypsum P()nd.
location for. construction of a sedimentation basin for detention of runoff from the Smelter
Complex, Bunker Creek, and Deadwood Gulch.
Other existing solid waste landfills within the Smelter Complex will be closed consistent with
appropriate RCRA 40 CFR Pan 264 requirements (Subpart N). A low permeability soil cover
system will be constructed over the solid waste landfills located on the east side of Deadwood
Gulch south of the mine/mill crusher plant in order to reduce surface infiltration through
potential source materials. Capping the landfills is expected to reduce potential ground water
loadings from these sources. Upon completion of remedial activities, all disturbed areas will
be re-vegetated or other appropriate permanent barrier installed.
9.2.6 Rights-of-Way
All rights-of-way (ROW) within the Site will be managed to minimize contaminant migration
and direct contact risk. The ROWs remedial action determinations will necessarily be site
specitic based upon location. utilization. and contaminant concentralions. In general all ROWs
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acid mine drainage, contaminated surface and ground water from Government Gulch, leachate
from the Lead and Zinc Plant closures, and other selected'surface water flows. The U.S. EPA
is selecting this system based upon information. presented in theFS, supporting Technical
Memoranda, an independent review of the literature. The system would operate by adsorption
and precipitation of metallic sulfides within an anaerobic wetlands substrate. The contaminants
would remain' bound in the wetland as long as the substrate remains anaerobic and saturated.
This system will be designed to maximize removal of contaminants from treated waste streams
as early as practicable. After source control remedial actions are in place and the system
operation has been optimized, it is U.S. EPA's expectation that the constructed Collected
Water Wetland treatment system will treat approximately eight CFS of contaminated water to
a minimum of 90% removal efficiency and will meet water-quality-based effluent limits prior
to discharge to the SFCDR. Currently the SFCDR is a water quality limited stream segment;
however, the IDHW, U.S. EPA, the Coeur d'Alene Tribe, and other interested state federal
and local agencies are considering developing a Total Maximum Daily Load (fMDL) for the
SFCDR, as required by the .Clean Water Act. Discharge limits for the Collected Water
Wetland and Ground Water Wetland effluents will. be determined as this process evolves as .
part of the Coeur d' Alene Basin Restoration Project. Should the Collected Wetland Treatment
System not meet both 90 percent reduction criteria and water-quality-based effluent limits
meeting the substantive requirements of an NPDES permit, pretreatment of influent
contaminant streams or modifications. to the treatment systems will be required.
. The second system, the 34. acre Ground Water Wetland' system selected for treatment of.
ground water is described in greater detail in the FS and supporting Technical Memoranda. In
general, this system is intend~ !otreat upper zone ground water flowing towards the SFCDR
in the western portion of Smelterville Flats: This'system will be'designed to' maximize the
efficiency of contaminated ground water capture in this area and maximize removal of
contaminants from ground water early as practicable. After.source control remedial actions
are in place and the system operation .has been optimized, it is U.S. EPA's expectation that the
constructed Ground Water Wetland treatment system will treat approximately. three CFS of'
contaminated water to a minimum of 90% removal efficiency and will meet water-quality- .
based effluent limits prior to discharge to the SFCDR. Should passive collection of ground,
water for. treatment not prove effective, active collection (i.e., pumping). will be required to
achieve recovery of contaminated ground water. Modifications to the treatment process will be .
required if performance standards noted above are not achieved. .
For both systems, long term management of wetland substrate and operations and management
considerations will be an integral part of the Remedial Design.
. 9.2.11 Public Wate.. Supply Considerations
The current availability of an offsite potable water supply for most Site residents effectively
limits the use of onsite water for domestic purposes; however, adequate supplies of suilable
water rilllst continue lO be available to minimize exposure to onsite surface and ground water.
Should offsite potable water become unavailable, additional actions may be required to assure
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. Development of institutional control programs for home remodeling
activities, including the normal replacement of carpets, floors, and attic
insulation. . .
. All homes with house dust lead concentrations equal to or exceeding
1000 ppm lead will have a one time cleaning of residential interiors after
completion of remedial actions that address fugitive dust. If subsequent
interior house dust sampling indicates that house dust lead concentrations
exceed a site wide average of 500 ppm lead the need. for additional
cleaning will be evaluated.
. Home interiors of children identified through health screening will be evaluated and
if needed site specific remediations will be performed.
. Additional interior dust studies will be developed during remedial design to identify
sampling and decision making criteria for the one. time cleaning. ...
9.2.9 Future Development in Non-populated Areas
With the exception of certain areas within the Site' that are integral components of. the remedial .
actions (e.g., Lead Smelter cap and constructed wetland systems), currently undevel9ped areas .
of the Site may be utilized in the future, consistent with local land use controls.
The institutional controls program will guide: the establishment of effective barriers in a!"eas
where surficial (top one foot) soil lead concentrations exceed. 1,000 pprn lead. In' areas where
lead concentrations are below 1,000' ppm lead. no special considerations will. be .required"
beyond those typically required for new developments. The exception to this would be
creation of a new residential development in a currently undeveloped area of the Site. Such a
development would have to have an average residential yards lead concentration less than 350 .
ppm lead, with no property exceeding 1,000 ppm lead, and would. need to be 'effectively
isolated from nearby areas that would expose residents to surficial lead soil levels exceeding
1,000 ppm. New developments not meeting. these criteria will require remediation prior to
residential use as described in the Residential Soils ROD.
Non-populated Areas with the potential for future development will be remediated to address
current human health and .environmental concerns as discussed in this section. Remediation
activities specitic to conditions at future land use locations will be implemented, as
appropriate, as development occurs via institutional controls (see Section 9.2.14).
9.2.10 Constructed Wetland TI.catmcnt S~'stCnlS
Two constructed wetland treatment systems are selected for the innov~Hive treatment of surface
water and ground water. The tirst system (Collected Water Wetland) will occupy.
approximately 74 acres in Smelterville Flats and ~s intended to treat CIA seeps, pre-treated
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9.2.14 Institutional Controls
Institutional controls, which include a variety of legal restrictions and regulations on the use of
land where potentially hazardous levels of contamination will remain after completion of this
remedy, are an important component of remedial actions for the Bunker Hill Superfund Site.
The Residential Soils ROD issued in 1991 requires the use 'Of institutianal controls for
maintenance of residential soil barriers ta prevent human contact with cantaminated soils after
removal and replacement of contaminated surficial sail.
This remedy also relies upon institutional contrals ta assure the protectiveness 'Of selected
remedial actions, including ceitain hillside areas within the Site which have surface soii
cancentratians that' exceed residential soil cleanup gaals far lead, and which are likely to be
developed in the future. Institutianal controls will guide the future development 'Of these areas
to ensure that apprapriate remedial actians are taken, including the. use 'Of protective barriers
an cantaminated sails, ta protect future residents. and users 'of. such areas from exposure
presenting unacceptable risks. In additian, institutianal controls will assist landawners wha.
undenake prajects by praviding guidance and certification of compliance with the institutional
,cantrals regulatary program.
The NCP sets aut U.S. EP A's ,expectatian that institutional contrals "shall not substitute for' ,
active response measures [that actually reduce, minimize, 'Or eliminate contamination] as' the ' , '
sole remedy unless such measures are determined not to be practicable. ~ 40CFR ,Pan
300.430(a)(I)(iii)(D). Nevertheless, where active remediation is not practicabl~, institutional'
contrais may be "the only means available to provide for ,protection of human, health." 55
Fed. Red. 8666, 8706 (r-...tarch 8, 1990). In addition, institutianal controls may be ','a necessal')'
supplement where waste is left in place as it is in most response actians. ',' , Id.
Accordingly, U.S. EPA has determined that institutional ,controls are both an acceptable and
integral camponent 'Of remedial actions for bath the Residential Sail ROD and this :Nan- . .
papulated Areas ROD. Institutional controls have, been identitied and evaluated in the
Residential Soil Feasibility Study and RADER, and U.S. EPA and IDHW have partiCipated in'
the development 'Of the Panhandle Health District's evaluation of such cantrols in the Papulated ' "
Areas. Institutianal controls were alsa evaluated in the Nan-papulated Area FS.
The January 25, 1991; Draft" Evaluation of Institutianal Controls for the, Populated Areas of
the Bunker Hill Superfund Site," prepared far the Panhandle Health District 'Outlines the need
far and purpose of a comprehensive Institutianal Cantrols Program (ICP) far the Bunker Hill
Site. There are faur main companents of the ICP, including:
I. An Environmental Health Cade:
2. Performance Standards far remedial actians (e.g.. specificatians far barriers):
3. An educational program far residents and contractors (0 familiarize themselves with
ICP requirements;
4. A testing and monitoring program ta evaluate the effectiveness 'Of the (CP.
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a safe drinking water supply until onsite sources are restored to a suitable quality. As
discussed previously, restoratiQn of onsite water resources is dependent upon control of
upgradient sources of contamination to surface and ground water as well as onsite remedial
actions.
Except as noted below, all ground water wells within the Site that are in the main valley
aquifer, either upper zone, lower zone, or other contaminated wells within the Site will be
closed or abandoned according to the State of Idaho requirements. Existing domestic wells
selected for closure will be replaced by an existing alternative water supply if the residence is
not already serviced by a municipal water system. Industrial wells will be replaced by an
alternative water supply as needed. Monitoring and. aquifer test wells wili not require
replacement with an alternative water supply. Monitoring wells will be closed if they are not
required for continued monitoring. Approximately 48 domestic wells, 43 industrial wells, and
317 monitoring wells will be closed. .
9.2.12 Soil Action Levels
Remedial actions for specific areas of the Bunker Hill .Superfund Site .are outlined earlier. in
this Section. Additional details on these remedial actions are provided in the FS description of
. Alternative 3.and supporting Technical. Memoranda. In general~ the decision regarding how a..
particular area of surface contamination is' addressed is' a . function of the area it is within.
Areas that are primarily impacted bya mixture of tailings.and. alluvium (soil) . are suitable for
capping. These areas represent a high volume, low concentration source that is appropriately.. .
managed by a combination of containment technologies and institutional controls. This
approach is consistent with U.S. EPA's previousiy issued Residential Soils ROD... .
Areas that have been impacted by contamination from mineral processing facilities (e.g., lead
smelting, zinc refining, etc.) are slated for removal since .these wastes are generally 'of higher
concentration and require a greater level. of management in order to insure a' protective.
remed y. .. . . .
For the purposes of this ROD, clean replacement soils are considered to contain less than 100
ppm lead, 100 ppm arsenic and 5 ppm cadmium.. .. .
9.2.13 Operations and Maintenance Requirements
Specific Operations and Maintenance (O&M) requirements for all remedial actions .selected in
this Record of Decision will be developed during the Remedial Design process. 0 & M
requirements are an integral component .of remedial actions and must be planned and
implememed to ensure the long term effectiveness of selected measures. Long term protection.
of human health and the environment is dependent upon the successful maintenance of barriers,
facility closures (i .e., CIA, Smelter Complex), erosion control structures, channel liners, and
contaminant treatment systems. 0 & M requirements must also be designed to complement
institutional control and Monitoring programs which are discussed below.
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intervention response. Outlined below are specitic response actions for blood concentration
ranges.
I!Wli
Follow Up ResDonse
10-14 Provide rescreening and community-wide childhood lead poisoning prevention
activities. . These prevention activities will be pan of the Institutional Control
education program.
15-19 Response as listed for 10-14 JLg/dl plus home visits by health professional and
provide nutritional and educational intervention. If appropriate, recommend a
special education evaluation for school age children by the local school district.
20-44 Responses as listed for 15-19JLgldl plus recommend a visit to a family physician.
Children between the ages of 9 months to 9 years will be included in the program. The
program will continue to offer incentives to children for having their blood. tested. A house
dust sampling program will be continued. . Home visits would include environmental
evaluations which examine house dust, residential soils, vegetable gardens and paint.
Pregnant women will also be screened. However, no incentives would be'provided, as is the
case Jor children. Women with blood lead levels greater than 10 Ilg/dl would be referred .to
their physician fQr medical evaluation. Additionally; a .home visit would be cQnducted and the
expectant mother provided with nutritional and intervention information. .
Once remedial actions are completed and .bloodlead levels have decreased to meet the RAO . .
described above, .the health' intervention program will be scaled back' to provide blood lead
testing. upon request only. The same follow up responses for children and pregnant.women
with elevated blood lead levels will be activated. However; the number of individuals needing
follow up would be low. .
The Panhandle Health District has stated that it will only manage and administer the ICP for as
long as it is fUl)ded, as the Panhandle District Board of Health has not, and will not, authorize
funding for any of the Institutional Controi Program activities. Community acceptance of.the
ICP program, as expressed during the .public comment .period, is also conditioned on such
controls being self-sustaining with no additional costs to Site residents or local governments.
9.2.15 Monitoring
Extensive monitoring of soil, water, and air is an important component of the remedial actions
outlined in the ROD. Monitoring is required for the following purposes, in addition to those
that may be required during Remedial Design.
. To evaluate compliance with ARARs in surface and ground water
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The Panhandle Health District held numerous meetings with local elected ofticials regarding
the development and implementation of the ICP. On February 24, 1992, the Panhandle
District Board of Health formally approved the Panhandle Health District's involvement as the
management entity for the Institutional Control Program and their commitment to amend the
existing Environmental Health Code to include specific Contaminant Management Regulations
and performance standards. In May 1992, the Panhandle Health District completed a draft of
an Environmental Health Code, also known as Contamination Management Regulations.
Once finalized and adopted, the Contaminant Management Regulations will be incorpqrated
into the Panhandle Health District's Environmental Health Code, and are expected to govern
all excavations, building, development, grading and renovations within the Site and potentially
other areas affected by heavy metal contamination within the Panhandle Health District's
jurisdiction in Shoshone County.
The Environmental Health Code will also include specific performance standards to regulate
and provide guidance for all activities encompassed by the ICP. The performanCe standards
will establish minimum requirements when barriers are to be established or breached and will
govern the following activities: .. .
I. Building Inter~or Construction/Modification
2. Exterior Construction
3. Subdivision Development
4. Transportation
5. Di sposal
6. Clean Materials Supply Program
After adoption of the Environmental Health Code and performance standards; the Panhandle' .
Health District will then develop an educational program component of the ICP, based on the
final ICP performance standards. The Panhandle Health District. will then administer and '.
oversee the testing and monitoring component of the ICP.
In addition, the Health Intervention Program, as described below, will be continued 'at least.
through the completion of remedial action. This program identifies children and pregnarit.
women who are being impacted by lead exposures and provide intervention activities to
mitigate such exposures.' . .
Blood lead screening should continue as it is currently being performed until the Remedial
Action is completed and the blood lead concentrations Remedial Action Objective is met. This
RAO requires that blood lead levels decrease until 95 % of the children tested-have blood lead
levels below 10 ILg/dl with less than I % of children having blood lead levels above 15 ILg/dl.
The objective of the screening program will continue to be the identitication of children who
have elevated blood lead levels and need follow up to reduce lead exposures. The Centers for
Disease Control guidelines for follow up activities will be used to determine appropriate
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areas prior to these activities, having fire extinguishers at hand, and providing a fire watch for
an appropriate period after all ignition sources have been abated.
The management of the release of contaminants during remedial construction activities will also
be performed. This' will include the management of high flow runoff to minimize sediment-
transport in surface water. Storm water management during remedy implementation will be
consistent with all State and local requirements. Best Management Practices employed during
remedial action implementation will include extensive use of storm water detention facilities to
minimize impacts from runoff events until monitoring of remedial actions have demonstrated
their effectiveness in mitigating contaminant loading from runoff events.
Any repairs required to community infrastructure, such as roads and utilities, due to the
implementation of remedial actions required in this ROD, will be implemented as appropriate.
9.3 CHANGES TO PROPOSED PLAN
Residential soils were originally intended to be consolidated on Page Pond or another. suitable
area onsite. For clarification, it is also appropriate to utilize residential soils as. a sub-base.
material for the closure of the Lead Smelter and Zinc Plant, or as a component of the final
cover of these closures if surface' concentrations are below 1000 ppm. lead and access is
controlled.
Language has been added to Section !O of this ROD to cJarify when the contingent waiver. of
ground water ARARs in the main valley aquifer would become effective based upon technical
impracticability. It has been further clarified that, while remectial actions outlined in this ROD.
seek to limit the impacts of site contaminant sources on the SFCDR, achievement of FWQC in
the river is beyond the scope of this ROD and attainment of FWQC in the SFCDRis not an
ARAR for this ROD.
Preliminary results of treatability testing of Principal Threat material accumulations indicate
that a rain water leach test is more appropriate under the circumstances of this release. than the
acid leach test typically utilized for design of stabilization mixtures meeting LDR requirements.
Therefore, a rain water leach test will be used in lieu of an acid leach test to design' the
cement-based stabilization mixture for treatment of Principal Threat waste. This test will be. a
modification of U.S. EPA Method 1320 utilizing water with a pH representing local
conditions, rather than acidified water.
9.4 QUANTITY OF MATERIALS REMOVED, CONTAfNED, AND TREATED
Table 9-2 provides a summary of quantity of materials removed, capped, and treated.
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"
.
. To assess the status of environmental receptors (i.e., biological monitoring)
. To evaluate the performance of specific remedial actions and their respective 0 &
M programs
. To evaluate success in meeting. public health protection goals (i.e., continuation of
blood lead screening program)
. To evaluate the adequacy of control measures instituted during implementation of
remedial actions.
Monitoring programs will be utilized to evaluate the success of remedial actions in protecting
human health and the environment and will serve to assist U.S. EPA in determining the
adequacy of remedial actions selected in this ROD.
9.2.16 General Remedial Design/Remedial Action Considerations
During remedial actions certain activities will have to be maintained or implemented. to protect
human health and environment. These activities include; dust control, access control, fire
control, and the management of the release of contaminants during remedial construction
activities.
DuriJ1g remedial construction activities, dust control measures will be implemented site wide to
prevent the tnmspon of contaminated material. The dust control activities can include the use
of water to wet down areas or polymeric, chemical, oj'" physical surface sealers fpr temporary
dust control. Some of the areas that wi1\ receive .temporary dust control include Page Pond.
and CIA surfaces and dikes, roads in the populated and non-populated ROW, Smelterville
Flats, the Smelter Complex, and other source areas that generate fugitive dust. Institutional
controls will also be applied to restrict access to potential source areas to control transport .of
contaminantS within the site and exposures to contaminants of concern.
Access control will be maintained in' all areas where it currently exists lintil the remediation in
that area is completed. Access controls wi1\ also be used to prevent exposures during remedial
actions. Access controls will include fencing, signs, and security patrols and guards. .
Fire control will be in place until remedial actions are completed in the Smelter Complex and
MOA. Fire control will include quarterly inspections of all structures until they are either.
demolished or decontaminated. The necessary fire protection materials, including the
necessary water supplies, will be maintained as long as the potential for release of
contaminants through fire exists. This will include coordination with the local tire district to
provide the necessary information for safe access should it be necessary to tight a fire. Also
included in tire control is the use of tire protection during all activities involving potential
ignition sources. such as cutting and welding activities. These activities include wetting down
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.
...
ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
AREA/SUBAREA
DESCRIPTIONS
ColI~cted water. wetland treatment
8 efs
REMOV ALb TO
CONT AINMENT8 OFF.IONSITE OTHER'
CLOSURES
228 acres
380 acres
74 acres
34 acres
36,000 cy
334 acres
TREAT OR
RECYCLEI
REPROCESS
COl1taminat~d alluvium and jig tailings will be removed for constru"cted
\vdland systems and tloodway construction.
6" of soils or permanent barrier to cov~r remaining Jig
Tailingsl Alluvium mixtures then revegetale.
\D
I
N
N
GJ'OUJIlJ \Val~r w~lland treatment
3 efs
Pr.:lrc:almc:nt pond
8 cfs
R~v~g~lal~ accessible ar~a not olherwise remediated
..
..,.,".",".";-,,
12" of low permeabililY materials, overlain by a 6" clean soil
(including the CIA dikes IInd surround areas), and vegetate.
ColI~cl and tr~at seepages from the CIA closure
280 acrljs
371,670 ey
3 efs
Ex\:aval~ material accumulations in the Easl cell to Ihe Smelter closure.
31,000 cy
DlI~ to the complexity of the remedial actions and the fact that many remedial actions are difficult to include in the above categories, the
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ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
AREA/SUBAREA
DESCRIPTIONS
TREAT OR
RECYCLEI
REPROCESS
. .CONTAINMENT'
OTHER'
Reveg~tate eroding hillsides with areas having less than 50% cover.
R~v~g~late eroding hillsides with areas having less thAn 50% cover
within 50 + % cover. .
3,200 acres
500 acres
R~pair Riparian hahitat and slr~am corridor
al minimum, 100
ft. width
>D
I
1-.)
S~I~,'I~d M ill" Jumps
17 acres or 5 mine
dumps
Gullies identiti~d for remediaillclions
12,000 lin. fl.
Terra""" l'!>lllplekJ
42 miles
"nlp",,,d n"w ("rnll:e"
160,000 lin. fl.
42,000 lin. fl.
T.:rra,',:" in n.:ed of r.:pair
5.:tlil11.:nl tI.:t~nlion Basin
6 @ 10 fl. deep
Due to the complexity of the ,'emedinl actions and the fact that many remedial actions are difficult tu include in the above categories, the
IIIllIlhl:rs repol1ed here !lI'e intended only for general information. .
#
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4
..
..
..
..
..
ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
AREA/SUBAREA
DESCRIPTIONS
TREAT OR
RECYCLE/
REPROCESS
CONTAINMENT'
REMOV ALb TO
OFF-/ONSITE
CLOSURES
OTHER"
Tro:al Pril1l:ipal Thr.:al Mat.:rial al:cumulations and solis
Channdil.e: und 11I1e: Gov.:rnm.:nl und Bunker Creeks with diversion und
Ire:alme:nl of base flows
NQ
319,000 cy
80,000 cy
3,500 fI piping
319,000 cy
Upper Milu Creek ':Xl:aVUlll/n und I:hanndiz.atiun
20,000 cy
-
CUlOff wulls will he constructed al upper and lower Government Gulch
14,000 sq. fl.
-D
I
N
~
Governmenl GuidI surface wule:r Ire:alme:nl
I I cfs
Bunk"r Cr.,eI. ~urfae" waleI' Ir"alm.:nl
3 4 crs
Guve:rnmt:nt Gukh t:xcavalion und chunneliz.alion
40,000 cy
Close Ihe mill st:llhng pond
NQ
RO:l11ove: and disposo: of uny sludge: re:maining in Ihe: nollum of Ihe mill
selliing pond
1.200 cy
Re:l11ovo: or l'ar in place the: A.4 Gypsum pond
19 acres
115,000 cy
485,000 cy
({cnIO"., Ihe A I Gypsum pond
3 7 acn:s
Clo~e: olht:r t:xislmg solid wuste: landlills
23 acres
94,000 cy
Due 10 Ihe complexity of the remcdial actions and the fact that many remedial actions are difficult to include in the above categories~ the
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....."
ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
A R EAtS CJ SA REA
DESCRIPTIONS
T c::mporar)' Dust Control
TREAT OR REMOV ALb TO
RECYCLEI CONTAINMENT' OFF.IONSITE OTHER'
REPROCESS CLOSURES
245 acres
40.60,000 cy
6 acres 25,000 cy 8,000 ft
87,500 cy
40 acres
40 acres
Jig lailing accumulations from Wt:sl Page Swamp will be removell anll
placc::lI on Page: Ponll
Crt:t:k channels excavation anll revegeiatioo
~
I
N
W
Regralle and cap Page Tailing Impoundment with residential yard soils
Re\'egdalt! after placement of 6" cle:an soils
T c::mporar)' Dust Contrul.
s'M:g4ifg~.qgMg~gx.~~~.MtN£:::~~gBi.ii2m~..~~~A:;~N1~I)liii!:::::::...:::.i::,....::..:j:;::::n:;:::::::t!::(.: .... ... ...
..
...
SMELTER COIVIPLEX
T emporar)' lIust control me:asure:s
NQ
PCB-containing t:quipl11t:nt
88 units
Ashc::s!os Containing Matc:rials (ACM) to bt: removed anll repairell
NQ
NQ
Dc::hris frol11l1C::l11o. of struc!ures/llecontaminate salvageable materials
23-225,000 cy
Due tu the complexity of the remedial actions and the fact that many remedial actions are difficult to include in the above categories, the
IllJlllhers repurted here are intended only fOl' general information.
..
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.
.
\0
I'
,,,
Q'I
,
..
ESTI M AT ED QU A NTITI ES PERTA I N I NO TO T Y PES OF REM ED Y
A R EA/S U B A R EA
D ES C R I PT I 0 N S TR EAT OR R EM OVALb TO
R EC YCLEI CONTAIN M ENT" OFF-IONS ITE OTH E R'
R E PROCESS CLOS U RES
Ot h~ r l1Iakria Is/~oi I s dd~nni n~d 0 u ri n g Remed ial Design NQ
P I u g ex i st i n g wel Is 70 wel I s
Com mun i I Y wate r lank pu rc h ase N Q
P mv ioe al lernate wale:r su pp I i es 28 , 200 ft
,
V anao i u m ealal ySI 0 i sposa I 78 cy
Roao ano stag i ng ree I a ma I Ion 25 acres
Lon g t e rill pI 1110 ex L'ilval i un I acre I 7 . 500 cy
1\-1 I N E 0 PE R AT I ONS A R EA
CI ealIU I' materi a I from M OA Ilu i I 0 i I1gs decon laminated NQ N Q
s II rr.KC ~OI I s a 110 male n a I ace u I1IlI I at iOl1s w it hi n the M OA 22 ,000 cy
R~1111 IV~ h i !! h level s u f l'Ul1ta 1111 l1al IIIn materia Is consist en I wi 1 h flit lire NQ
I.. I 1.1 I IS\."
-
A ml 11 i mu m of 6 " of c lean SOl 1 or other appropriate barrier wi I 1 be NQ
appl ieo whe rt' su rfaet' coneen I rat ions exceed I 000 ppm lead
Due tu the cumplexity of the remedial actions and the fact that many remedial actions are difficult to include In the above categories, .the
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AREA/SUBAREA
DESCRIPTIONS
D~l11ulish Zinc Plants and cap and r.:vegetate
Dell1l!li~h L~ad Sl11dler and cap and revegetale
Dell10lish (I) uno rell10ve (2) Pho~phoric Acid/Fertilizer Plant
Surface waste diversion ditch
\!)
I
1-.)
VI
Addilional plant area~ revegdation
L.:al'hat~ clIlkctilln for closur.: Slrlll'tUres
Cllnlul11inal~dl11alerials and soils from the "boney,ard area"
SlIlI1" Slag from Ih" west cell of the CIA till under Ihe final cap
R.:~idenlialsoils collected during oth.:r remediaillclions to facilitate
c'apping and rev.:g~tat ion .
~vlah:rial removed within the MOA incluuinglh.: houlevard ar.:a during
remed ialion,
Ma~nd Gukh de:tnup n1:lterial accumulations and contaminated spits
ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
TR~AT OR
RECYCLE/
REPROCESS
NQ
CONTAINMENT'
53 acres
50 acres
20 acres
150 lIen:s
REMOV ALb TO
OFF-/ONSITE
CLOSURES
491,000 sq. ft.
400,900 sq, 1'1.
90,100 sq.ft. (I)
2,700 cy (2)
44,000 cy
NQ
NQ
"
NQ
NQ
OTHER"
2,350 ft.
Dill' to the COl11plexity of the I'cmedinl actions and the fact that many' remedial actions are difficult to include in the above categories, the
IIIllIIbel's .ocported here arc intended only for general inforn'iation.' .
.
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m~~~~~~i:ties:'~II~alf1:",
..
ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
AREA/SUBAREA
DESCRIPTIONS
REMOY ALb TO
OFF-IONSITE
CLOSURES
TREAT OR
RECYCLEI
REPROCESS
CONT AINMENT"
OTHER"
5"",,,,; Hllnk,r Hill 5111,...1'111111 Si" F':lSihility Study Report, Volun". I II III (App~ndices B, E. nnd KJ. Executive Summary. and Technical Memoranda
:1 C,uUainm(nl indull..:s.: h:II'I'i~..!O. r~v~~~talion. caps.
b T" b~ pl:2-:(rl in dlHUlr~ ..:..:11
",' Olh~1" indlltl~s: r~l':lir. r~gr3tl~ div..:rsinns! inl~rior hotls,,: cI..:aning!
Nlll-:: CUIUIUI1:\ al'~ 11\11 iu.hliliv..: ~UI11": IUllnh..:r:4 on: lish:d O1ur..: Ih:.o on.:..:
Fur .xnll1p" Ih. 3 cr. rrom the CIA ."p. will be pD.1 or the 8 cr. IreDted in the collected water wetland
'"
I
N
ex>
NV 1= J NUl ~1I"lIlili",1
Duc tn the complexity of the remedial actions and the fact that many remedial actions are difficult to include in the above categories, the
IIIllI1bers rep0l1ed here are intended only for general information.
.
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'"
ESTIMATED QUANTITIES PERTAINING TO TYPES OF REMEDY
AREA/SUBAREA
DESCRIPTIONS
REMOV ALb TO
OFF-!ONSITE
CLOSURES
TREAT OR
RECYCLE!
REPROCESS
CONTAINMENT'
OTHER"
\D
I
N
-.J
Pr~-tr~atment of acid min~ drainag~ in the CTP
Capping in th~ NOlI-populated Arc:as
T ~l1Iporary dust control m~asures
Prok.:tiw harri~r (6" <.:I.:an soils or grav.:!, or a paved surface::
fur scnsitive area) 011 surf
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Table 9-3
Summary of Estimated Costs for Selected Remedy
CAPI'.rAL COS'.r ANNUAL O&M COS'.r
I'.rEM is\ is \
COLLECTED WATER WETLAND
Excavation and Construction Work 2 344 558
Coarse & Fine Gravel (onsite and 1,899,005
offsite\
Purchase and Place Liner 2 092.974
Place Gravel 501.424
Hvdraulic C':Jl':trols 11 385
Bunker and Government Creek Pinina 70 000
SumDS and Controls 6 325
Pretreatment Pond 194 760
Haul Road UDarades 63 250
Reveaetation and Fencina 337 116
Subtotal S 7 520 796 S 1 612 000
SFCDR CHANNEL ENHANCEMENT
Exca,,-ation 2 OOS 330
Levee Construction and Riorao 1 801 270
Reveaetation 49 145
Subtotal S 3 855 745 S 335 000
GROUND WATER WETLAND
Excavation and Construction Work 2 374 054
Coarse and Fine Gravel 5'52 336
Place Gravel 230 384
Hvdraulic Controls 2 530
Road, UDarades 31 625
Reveaetati-on and Fencina 150 538
Subtotal S 3 341.467 S 961 000
ENHANCED WE'.rLAND S 316 250 S 116.000
SMEL'.rERVILLE FLA'.rS REVEGE'.rA'.rION S 1 628 470 S 704.000
PAGE SWAMP JIG TAILINGS REMOVAL/WETLAND IMPROVEMENT
Excavation 608 044
Channels Reveaetation 10 816
Outlet Controls 2 530
PWTP Ou" - et Diversion 18.360
Subtotal S 639,750 S 178.000'"
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9.5 COST
Cost evaluations, including the assumptions used, are presented in the Non-populated Areas
Feasibility Study (FS) report. A summary of estimated capital, both direct and indirect, and
O&M, and net present worth costs associated with the selected remedy is outlined in Table 9-
3. Contingency allowances have been included in the estimates, consistent with the extent of
the uncertainties. . The accuracy of the estimates is expected to fall within the acceptable range
of +50 percent to -30 percent, as outlined in the NCP.
Capital costs are those required to initiate and construct the remedial action. Typical capital
costs include construction equipment, labor, and material expenditures, engineering, aCId
construction management. The total estimated capital, including direct and indirect costs, is
$56.6 million (Table 9-3). .
An implementation period of six years for the selected remedy was assumed for cost estimation
purposes. The exact duration of initial implementation and corresponding capital cost
distribution is dependent on the results .of the Remedial Design Phase. The capital cost for
each year is converted to 1991 dollars. Using a three, five, and ten percent discount rates and
a 30-year estimated project life, the present worth cost for the selected remedy is $57.2, $52.0,
and $42.4 million, respectively (Table 9-3). Capital costs and long-term annual O&M costs .
are included in the total present worth cost.
Estimates for the cost of O&M activities are prepared for operations expected to be performe.d
for the 30-year period following site remediation. Site wide monitoring costs, a contingency
fund for unpredicte.cl events, and allowance for periodic site reViews are not included. These
costs are necessary to ensure the continued effectiveness of the remedial action. .
The feasibility study cost estimates have been prepared for guidance in project evaluation and
implementation from the inform~tion available at the time of the estimate. The final costs of
the project will depend on actual labor and material costs, actual site conditions, productivity, .
competitive market conditions, final project scope and schedule,and other variable factors. As
a result, the final project costs will vary from the estimates presented here. .
The cost esti mates as presented in the FS do not include costs for the Hillside work that is
required by a 1990 Hillsides AOC or additional cost of revegetation in the 50 - 85% cover
class. The costs for commercial buildings and lots, Tights-of-way, interior dust remediations.
and compliance with National Historic Preservation Act were also not estimated. . However,
the cost estimate does include the cost of demolishing the two tall stacks which is. not a
required component of this ROD and the solidification of the copper dross flue dust (CDFD)
which has already been relocated to the Lead Smelter in preparation for stabilization as
required by a 1991 UAO issued by the U.S. EPA. .
[n addition to thc costs specified in this ROD, site wide cleanup also includes an estimated $40
million dollars to implement the Residential Soils Rccord of Dccision, and approximately $20
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.
.,
Table 9-3
Summary of Estimated Costs for Selected Remedy
CAPITAL COST ANNUAL O&M COST
ITEM (S\ (5\
ZINC PLANT DEMOLITION AND CAP
Demolish Buildinas and Stacks 1 723 900
Construct Soil Cover 302 000
TODsoil Purchase and Placement 878 940
Reveaetation 100 570
Surface Water Diversion Ditch 65 510
Fencina 50 600
Subtotal s 3 121 520 s 588.000
PHOSPHORIC ACID/FERTILIZER PLANT DEMOLITION AND REMOVAL
Demolish Buildinas 200 880
Remove Foundations 170 800
TODsoi1 Purchase and Ren1acement 331 633
Reveoetation 37 950
Subtotal s 741 263
I-H;ATERIALS REMOVAL AND TREATMENT
CODDer Dross Flue Dust :i 200 000
Acid Tank Bottom Sludoe 60.000
Other Wastes 1 320 000
Subtotal S 2 580 000
HAUL ACCUMULATED MATERIAL TO SMELTER " $ 2,087,250
CLOSURE AREA
IMPOUNDMENTS CLOSURE S 109 994
INDUSTRIAL LANDFILL CAP
Earthworks 891 120
Monitorina Wells 150 875
Reveaetation 43 643
Subtotal $ 1,085,638 $ 907,000 ""'
CAP A-4 GYPSUM POND
Construct Cae lonsite materials\ 93 620
Purchase and Soread Tonsoil 318 680
Reveaetation 36 053
Subtotal S 448 353 S 330 000
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..
~
Table 9-3
Summary of Estim,ated Costs for Selected Remedy
CAPITAL COST" ANNUAL O&M COST
ITEM i~\ is\
HUMBOLDT AND GROUSE CREEKS CHANNELIZATION S 60 000
PAGE POND CAP iSDreadina & Reveaetation\ S 223 775
CIA TAILINGS CLOSURE (East Ce 11 \
Excavate Plant Wastes for Renositorv 388 355
I
Grades SloDes 557 700
Clav CaD Excavation and Placement 1 575 662
Purchase and SDread TODsoil 2 819 455
Access Roads 273 564
Reveaetate 322.575
Haul Road Unarades 31 625
Subtotal S 5.968 936
GYPSUM A-5 POND CLOSURE (Middle Cell\
Cut Drains 123.057
Plua Drains 22 342
Pice to CTP 54 000
Grade 51.00<"5 I 400 067
Clav CaD Excavation and Placement 695 145
Purchase and 5nread TODsoil 1 243 880
Reveaetate 142 313
Haul Road UDarades 12 650
Subtotal S 2.693 454
" .
CIA SEEP COLLECTION
Trench . Construct wi Gravel Placement 253 000
Picina 140 000
Subtotal $ 393,000 $ 795 t 000 .",
LEAD SMELTER DEMOLITION AND CAP
Demolish Buildinas and Stacks 1 402 340
Construct Soil Cover 720 000
Tocsoil Purchase and Placement 828.568
Reveaetation 94.880
Surface Water Diversion Ditch 115.950
Fencina 75 900
Subtotal $ 3.237 638 $ 633 000
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;
.-
Table 9-3
Summary of Estimated Costs for Selected Remedy
CAPITAL COST ANNUAL O&M COST
ITEM (5 \ 15\
HEALTH AND SAFETY
Worker Costs 797.160
H&S Staff 676.775
Air Honitorina 632 500
Supplies and Support 442.750
Subtotal !: 2 549 185
I i
COSTS SUMMARY TOTAL COSTS TOTAL O&H COSTS
TOTAL DIRECT COST 547 293.000
ENGINEERING 5 4 550.000
CONTINGENCY 5 4 729.000
TOTAL INDIRECT COSTS 5 9 279.000
TOTAL COSTS 556 571 000 511 096 000
GRAND TOTAL .. 567 667.000
TOTAL PRESENT WORTH (3% Discount Rate\ 550 556.000 S 6.676 000
TOTAL PRESENT WORTH (5% Discount Rate\ 547 049 000 5 4 986 000
TOTAL PRESENT WORTH 110% Discount Rate\ 539 694 000 S..2 727 000
(al O&M C:IISIS ror Ille r:q;e I'mld areas.
(hi O&M c:osts ror tbe CIA ur.,.dS.
(c:1 O&M c:osL~ r..r botll G....enlluental Culch ch,uIIIl!lizatitlu and CoY~mlU",..IIIIIIIL:er Cr...,L: W;ller <:0111.<1;.111.
(d) O&M C:I~~IS ror both ludustn." LaudliU ulld lIi;;1I Le"d Repository..
Noles:
I. All c:n!>1.~ ",port4
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.
J
Table 9-3
Summary of Estimated Costs for Selected Remedy
CAPITAL COST ANNUAL O&M COST
ITEM (5\ ($\
A-I GYPSUM POND
Excavate and Haul to Middle Cell 437,000
Reveaetation 7,021
subtotal S 444,021 ~.9 ,000
ADDITIONAL PLANT AREAS REVEGETATION $ 284,625 $ 71,000
GOVERNMENT GULCH CHANNELIZATION
Excavation 57,200
Erosion Protection 240000
Cutoff Walls 88 200
Subtotal .$. 385,400 $ .527,000 (dl
UPPER MILO CREEK CHANNELIZATION ..
Excavation 28,600
Erosion Protection 120,000
Subtotal $ 14:8 600.
I EXISTING WELL PLUGGING $ 132..000 ..
COMMUNITY WATER TANK PURCHASE S 225 000
PROVIDE ALTERNATIVE WATER SUPPLIES .S 348 930
CLEAN MINE OPERATION BUILDINGS S 437,778
CIA WEST CELL REGRADING
Grade Slones 70 417 ."
Clay CaD Excavation and Placement 157 566
Purchase and Soread TODsoil 281 939
Reveaetate 32 258
Subtotal $ 542 180
VANADIUM CATALYST DISPOSAL. S 15 600
LONG TERM POND
Excavation 77 525
Liner Purchase 30 240
Fencino 10 753
Subtotal $ 118 518 $ 281 000
ROAD AND STAGING AREA RECLAMATION S 47 438
PCB DISPOSAL $ 1 509,344
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~
Jf.
million dollars which has been incurred to date for site investigations, removal actions, and
oversight of PRP investigations and response actions. To date, approximately 400 residential
properties have been remediated and numerous response action have been taken across the Site
to protect human health and the environment. These actions are discussed in Section 2 of this
ROD.
It is anticipated that although cost estimates presented in the FS and summarized in this ROD
do not include a specific itemization of every item of the selected remedial action, as noted
above, these omissions are offset by inclusion of other elements in the FS cost estimates that
are currently being addressed under U.S. EPA Orders. In any case, the overall cost estimate
is expected to ue consistent with RIIFS Guidance (U.S. EPA 1988).
9.6 PERFORMANCE REQUIREMENTS
Performance requirements for specific remedial actions are included in Section 9.2 of this
ROD, Remedial Actions by Subarea. During remedial design, monitoring programs will be
developed to evaluate performance of each remedial action. Additionally, 0 & M
requirements will provide for continued achievement of performance standards over time.
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~
'i
at least attains legally applicable or relevant and appropriate federal standards, requirements,
criteria, 'or limitations, or any proinulgated s~ndards, requirements, criteria, or limitations'
under a state environmental or facility siting law that is more stringent than any federal
standard (ARARs). In instances where the remedial actions do not achieve ARARs the basis
for a waiver must.be provided by U.S. EPA. .
The federal and state ARARs for this remedy, identified by U.S. EPA' and roHW,
respectively, are presented in Tables 10. I through 10-6. These tables cite the requirements
. identified, state whether the requirementS are applicable or relevant and appropriate.
summarize the substantive standards to be met, and specify where in this ROD the
requirements mu~t be met. It is expected that this remedy wili satisfy all ARARs identified,
except in the instance where the contingencies outlined below for attainment of groundwater
ARARs in the main valley aquifer demonstrate the technical impracticability of achieving
chemical-specific ARARs for certain areas of the aquifer. Because of the complexity of this
remedy, the applicability of certain of the ARARs'is discussed below. Additional analyses of .
ARARs is presented in Section 8 of the Non-populated Feasibility Study and Section 2 of the
Residential Soils Feasibility Study. . .
Ground and Surface Water ARARs
Section I21(d) of CERCLA, 42 U.S.C. ~ 9621(d), specifically states that remedial actions
shall attain a level or standard of control established under the Safe Drinking Water Act
(SDW A). where slich level or control is applicable or relevant and appropriate to any
hazardous substance, pollutant or cont.aminant that will remain onsite. The enforceabie
standards under the SDW A are m'aximum contaminant levels (MCLs) which r~present the
maximum permissible level of a contaminant which may be delivered to any user of a public
water system. Section l"21(d) of CERCLA also states that remedial actions shall attain
maximum contaminant level goals (MCLGs) where such goals are relevant and appropriate.
(MCLGs are health-based goals set at levels at which no adverse health effects may arise, with
a margin of safety.)
MCLs are only legally applicable under the SDWA to the quality.ofdrinking water at the tap.
Therefore, MCLs are not applicable with regard to remediation of surface or ground water
which is not used or intended for drinking water purposes. They are, therefore, not applicable.
standards with regard to this remedy. In addition, because the riparian surface water onsite is
classified by the State for agricultural and non-contact recreational purposes, and not drinking
water, MCLs and MCLGs are not relevant and appropriate for remediation of onsite, riparian
surface waters. However. MCLs and MCLGs are relevant and appropriate for ground water
onsite since it is possible that the aquifer could be used for drinking water purposes in the
future. .
One goal of site-wide remedial actions is to restore ground water to its maximum beneficial
use. Currently. onsite ground water is utilized for domestic consumption only in limited
circumstances and primarily in areas outside of the contaminated valley aquifer system. Public
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.Ii
...
10 STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the' environment, will comply with
federal and state requirements that are legally applicable or relevant and appropriate (unless the
contingent waiver discussed in Section 10.2 of this ROD is invoked), and is cpst-effective.
The selected remedy utilizes alternative treatment and resource recovery technologies to the
maximum extent practicable. Because this remedy will result in hazardous substances
remaining onsite above health-based levels, the five-year review provisions of Section 121(c)
of CERCLA, 42 V.S.C. ~9621(c), 'will apply to this action. The following sections discuss
how the selected remedy meets the statutory requirements.
10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The remedy selected is protective of human health and the environment by. inhibiting the
significant exposure pathways through removals, containment, and treatment. The transport. of
'contaminants by air and direct exposure to contaminated soils will be controlled by removal of
contaminated materials or barriers. Base flow surface water' from contaminated onsite "
tributaries entering the SFCDR will 'be treated prior to. entering the river. Revegetation and
erosion control efforts on the hillsides will help control the transport of soils by surface water
runoff during' storm events. . A ponion of the ground water that enters the SFCDR in the
vicinity of Pinehurst Narrows and the CIA seeps will be collected and treated prior to entering
the river, as will the ground water in the Government Gulch. Infiltration through the Smelter
Complex and CIA caps will be minimized by implementation of effective clos!Jre methods,
therefore the impact to ground water from the-se areas will be reduced. PrincipaJ Threat soils
and source' materials will be treated prior to consolidation within the Lead Smelter closure.
This wiU effectively limit the potential of a release of Principal Threat material if. the .cap 'is
ever breached. .
The analysis presented in the FS demonstrates that the remedy sele.cted will reduce the
significant exposure pathways. When the remedial actions are completed and the Institutional
Controls Program is implemented, the risks associated with metal .contamination will be
reduced to acceptable levels: Therefore, V.S. EPA has concluded that the selected remedy
will be protective of human health and the environment.
10.2 COMPLIANCE WITH APPLICABLE OR
RELEV ANT AND APPROPRIATE REQUIREMENTS (ARARs)
Pursuant to Section 121(d) of CERCLA, 42 U.s.e. ~ 9621(d), remedial'actions shall attain a
. degree of cleanup of hazardous substances, pollutants, and contaminants released into the
environment and control of further release which, at a minimum, assures protection of human
health and the environment. In addition, remedial actions shall, upon their completion, react,
a level or standard of control for such hazardous substances, pollutants, or contaminants which
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;.
~
a.
augmentation of passive ground water collection at the Smelterville Flats ground
water wetland by active recovery of ground water (i.e., pumping) to increase
capture efficiency if RAOs for protection of SFCDR water quality due to onsite
sources are not. met due to ground water contributions to this segment of the
nver;
b.
modifications to the ground water (seep) collection system to be constructed north
of the CIA to increase contaminated ground water capture efficiency if RAOs for
protection of SFCDR water quality due to onsite sources are not met due to
ground water contribution~ to this segment of the river;
c.
active collection and treatment of contaminated ground water in Deadwood Gulch
and Magnet Gulch if source control measures in those areas are not successful in
controlling the continued release of contaminants of concern to the ground water
system at concentrations exceeding ARARs
d.
removal, containment, or treatment of discrete ground water contamin';j.nt sources
when it can be determined that additional benefits to ground water:;may be
achieved by such.actions.
If it 'is determined, based on the successful implementation of the selected remedy (Le.,
performance standards are met), and the above specified modifications, that certain areas of the.
vaHey aquifer system cannot be expected to meet ARARs. nOiwithsi3nding whatever additional
efforts which may .be made, independently of the actions required by this ROD to improve
upgradient ground water quality entering the Site, the following measures involving long-tenn
management may occur, for an indefinite period of time. as a. modification to the existing
system:
a.
a long-term program. will be developed and funded to insure the continued
operation of containment systems, (such as source contr:ol measures and ground
water recovery and. treatment components of the remedial actions) to limit the
continued release or migration of contaminants of concern;
b.
chemical-specific ARARs wi11 be waived for those limited portions of the valley
aquifer system not meeting drinking water ARARs. based upon the technical
impracticability of achieving further contaminaf)t reductions, as demonstrated by
implementation of the selected remedy and the modifications discussed above:
c.
institutional controls will be continued to restrict access to those portions of the
aquifer which remain above remediation goals:
d.
monitoring of ground water to evaluate changes in ground water quality and
insure the adequacy of institutional controls in limiting exposure to contaminated
ground waler;
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.
"
water supplies within the Site come from surface water sources that are unimpacted by Site
contamination. While domestic use of ground water is limited, there are some wells within the
valley aquifer system operated by individuals utilizing ground water for landscaping or other
non-consumptive purposes.
Remedial actions specified in this ROD will limit exposure to co~taminated ground water by
abandoning potentially contaminated wells and connecting additional users to the public water
supply system. These actions, in conjunction with the use of institutional controls to limit
future utilization of contaminated ground water, provide adequate protection of human health.
from this exposure pathway.
Notwithstanding the effectiveness of these actions in minimizing exposure of the resident
population to contaminated ground water, it is also a goal of this remedial action to improve
ground water quality, both for potential use as a water supply ,and to ensure that it does not
contribute to surface. water quality degradation.
Based on information obtained during the Remedial Investigation, and the analysis of remedial
alternatives,. U.S. EPA and IDHW believe that the selected remedy may be able to achieve the
water quality improvement objectives stated above. However, ultimate attainment of federal
Drinking Water Standards in the valley aquifer system will in pan depend upon the success of
upstream water quality improvement initiatives in controlling contaminant loading to the valley
aquifer system, as well as onsite actions. Ground water contamination may be especially
persistent in the immediate vicinity of contaminant sClurces, and in ponions of the valley
aquifer system most strongly influenced by upgradient surface and 'ground water contamination.
The ability to achieve cleanup goals (DWS ARARs and protection of surface water quality) at
all points throughout the valley aquifer system cannot be determined until the remedial actions
outlined in this ROD have been effective in meeting their individual performance standards
(specitied in. Section 9), and upgradient efforts to improve water quaiity have been
implemented. If the selected remedy cannot meet DWS throughout the valley aquifer system,
notwithstanding upgradient efforts that may be implemented independently of the actions'
required by this ROD; to improve ground water quality entering the Site, the contingency
measures described in this section may replace the selected remedy and ground water cleanup
goals. T~ese contingency measures will include refinement of ground water recovery and
treatment system components of the remedial action, and continuation of institutional controls.
The seLected remedy will include ground water extraction and treatment from the western
portion of Smelterville Flats, areas Nonh of the CIA, and Government Gulch for an estimated
period of no less than 10 years after the completion of site wide source control remedial
actions. Overall system performance will be carefully monitored on a ongoing basis and
adjusted as warranted to maximize system efficiency. r\'lodifications may include any or all of
the following: .
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.
.,
processing wastes) have been excluded from RCRA regulation pursuant. to section
. 3001 (b)(3)(A)(ii) of RCRA, 42 U.S.C. fi 6901(b)(3)(A)(ii) (these excluded wastes are referred
to as " Bevill-exempt"). Further, LDR treatment standards have not been promulgated for.
mineral processing wastes. Although LDRs are not applicable to any of the actions specified
in this ROD, U.S. EPA has determined that certain aspects. of RCRA LDRs may be relevant
and appropriate for the treatment of Principal Threat soil and material accumulations. As was
discussed previously, the relevant and appropriate aspects of LDRs for treatment of Principal
Threat waste will be attained through design of a. cement-based stabilization mixture that will
meet percent reduction goals andlor . extract concentration criteria outlined in the RCRA LDRs
for inorganic materials using a rain water leach test to simulate onsite conditions. Those
percent reduction standards are a minimum of; 90% for arsenic, 90% for mercury; 95% for
cadmium, 90% for antimony, 95% for nickel, and 99% for lead. Extraction concentration
criteria. are 1.0 ppm for arsenic, 0.008 ppm for mercury, 2.0 ppm for cadmium, 0.2 ppm for
antimony, 1.0 ppm for nickel; and 3.0 ppm for lead. .
. RCRA LDRs are . not applicable or relevant and appropriate at the Page Pond, CIA, Hillside,
mine dump, or Smelterville Flats portions of the Site because wastes in these areas are Bevill- .
exempt andlor their placement constitutes. consolidation within the AOC. While not applicable.
at the MOA, LDRs are relevant and appropriate there for wastes which will. be treated..
Finally, LDRs are not applicable or relevant and appropriate at the Wetlands System because
wastes there are being consolidated for in situ treatment. .
In addition to LDRs, RCRA can impose closure (40 CFR Pa..'1 264, Subpart G) and ground
water monitoring requirements (40 CFRPart 264 Subpart F). For purposes of tlns ROD,
RCRA. 40 CFR Part 264, SubpartG closure requirements are relevant and appropriate to the
Smelter Complex. With regard to potential wastes which may remain onsite as treatment.
residuals at the Wetland Systems, relevant and appropriate aspects of RCRA 40 CPR Part 264,
Subpart X will apply. At these areas of the Site, RCRA's substantive closure requirements
will be met. In addition, certain provisions of RCRA 40 CFR Part 264, Subpart G are
relevant and appropriate at the CIA and Page Pond. Compliance with the substantive
requirements for protectiveness under these sections will be achieved through. capping and
institutional controls as further described in Section 9.2 of this document.
Requirements for ground water monitoring under RCRA 40 CFR Part 264, Subpart F are
relevant and appropriate for RCRA wastes located at the Smelter Complex and the Wetlands
System. Although not applicable based on Bevill-exempt status, RCRA 40 CFR Part 264,
Subpart F requirements are relevant and appropriate at the Smelterville Flats, Page Pond, CIA,
MOA, and Hillside portions of the Site. The substantive requirements for ground water
monitoring will be achieved under the Site wide monitoring program established for the overall
remedy. .
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..
.
e.
periodic review will be performed of the success of upgradient water quality
improvement initiatives in enhandng onsite water quality; long-term
improvements may influence the requirements of the institutional control system.
The decision to invoke any or all of these measures will occur during periodic reviews of the
remedial action, which will occur at least every 5 years, in accordance with CERCLA section
l21(c) of CERCLA, 42 U.S.C. ~ 9621(c).
U.S. EPA has determined that the human health water quality criteria for ingestion of
o:rganisms (fish) and the chronic aquatic life water quality criteria (FWQCs) under the Clean
Water Act are applicable with regard to onsite tributaries to the SFCDR. With respect to the
SFCDR, the RI demonstrates that SFCDR water quality within the Site is substantially
controlled by loadings from sources upstream of the Site to a degree that even with total
elimination of loadings from onsite _sources, the FWQC for cadmium, lead, and zinc would
still be exceeded (See Section 5.2 of the Technical Memorandum: Post Remediation Water
Quality Projections for Feasibility Study Alternatives 2, 3, and 4). Because this ROD does not
address remediation of the SFCDR (except for the contribution from onsite sources),
attainment of FWQC in the SFCDR is not an ARARwith respect to this remedial action.-
Currently the SFCDR is a water quality limited stream segment; however, IDHW, U.S. EPA,
the Coeur d' Alene Tribe, and other interested state federal and local agencies are considering
development of a Total Maximum- Daily Load (TMDL) for the SFCDR, as required by the
Clean Water Act. Discharge limits for the- Collected Water Wetland and Ground - Water
Wetland treatment systems effluents wi!! be determined as this process evolves as part of -the
Coeur d' Alene Basin Restoration Project. - It is also expected that- control- and abatement of
onsite sources of contaminants will be effective in reducing metal loading to both ground and
surface water.
Five year reviews, at. a minimum., will be relied upon to evaluate .the effectiveness of the
selected remedy and compliance with ARARs. In addition, until the ARARs can be met, the
remedy will rely on the institutional control of water use to be adeq~lately protective-of human
health.
RCRA ARARs
RCRA imposes a number of requirements on remediation involving the disposal and/or
placement of wastes and therefore contains a number of provisions which may be ARAR at a
Site. Land Disposal Restrictions (LDRs) place specific restrictions on certain RCRA
hazardous wastes prior to their placement in a land disposal unit. Under CERCLA, placement
occurs when wastes are moved from one "area of contamination" (AOC) to another.
Therefore, wastes left in place or consolidated within one AOC are not subject to the
regulations. For purposes of this ROD, the entire Bunker Hill Site has been identified as one
AOe. LDRs. therefore, are generally not applicable. In addition. cenain wastes prodl1ced
through the extraction and beneticiation of minerals (and some speci fically identitied mineral
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.
.
I:L'~it~;~i~~~~1i~.t:iiw&, ...::~~~~:;,;:,j\~~j
Chemical-Specific Citation Prerequisite Requirement Location
I Air
A Applicable
Requirement
I Clcan Air Act
National Ambient
Air Quality
Standards
(NAAQS)
42 U.S C.
Section 740 I et
seq; 40 CFR
Part 50
Establishes
ambient au
quality standards
for emissions of
chemicals and
particulate
matter.
Emissions of
particulates and
chemicals which
occur during
remedial activities
will meet the
applicable NAAQS
which are as follows.
ISite Wide
..
Particulate Matter:
150 p.g/m3 24-hour
average
concentration, 50
J.Lg/m3 annual
arithmetic mean
Lead I 5 p.g Pb/m3
(.5 p.g Pb/m3 is
proposed)
B. Relevant and
Appropriate
Requirement
C To Be Considered
Materials
II. Soil and Dust
None
None
A Applicable
Requirements
B. Relevant and
Appropriate
Requirement
None
None
-------
..
.
Ashestos and PCB ARARs
The substantive standards of 40 CFR * 61 regarding management and disposal of asbestos and
40 CFR * 700 regarding PCB management and disposal are applicable at the Smelter Complex
and MOA portions of the Site. Before and during demolition, asbestos and PCB containing
materials will be properly managed pursuant to these regulations. Asbestos management
during remedial actions will also be consistent with U.S. EPA's policy regarding disposal
onsite.
Executive Orders
Executive Order 11990, 40 CFR Part 6, Appendix A, regarding wetlands protection is
applicable for the West Page Swamp remedial actions and certain portions of the Smelterville
Flats area. These areas will be managed to avoid adverse effects, to minimize harm, and, to
the extent practicable, to enhance wetlands in keeping with this Executive Order. In addition,
Executive Order 11988, 40 CFR Part 6, Appendix A regarding floodplain protection is
applicable at the West Page Swamp, Smelterville Flats, and Wetlands System portions of the
Site. Pursuant to the terms of this Executive Order, these areas will be evaluated for-potential
effects from flood hazards.
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"
.
Chemical-Specific
3. u.S. EPA Interim
Guidance
Concerning Soil
Lead Cleanup
Levels at Superfund
Sites
4. U.S. EPA Strategy
for Reducing Lead
Exposures
Citation
Office of Solid
Waste and
Emergency
Response
(OSWER)
Directive
#9355.4-02,
September 1989
Environmental
. Protection
Agency
October 3 I ,
1990
Prerequisite
Establishes an
interim soil
cleanup level for
total lead in
residential
settings.
Presents a
I strategy [0
i reduce lead
exposure,
particularly to
young children.
10-10
.. ", .
~ ".
',' :':'.:.
. A.k:AR~'.:.<"
...
Requirement
This guidance adopts
the recommendation
contained in the 1985
CDC statement on
childhood lead
poisoning (an interim
soil cle
-------
IW_'_i.!"!_!!"'....!1OC!.!
:[::::::::::IJI:I::I:i:::;:::::":,,
:. " .' . ..; ;"':':';';':',' ~.' : .y.-. ..::..-:;. ".' . . .:-; .' ",. " . '. "".
'.> . ,'C".,' -',,::::::';:;,,::,::::,::;::':,:,::;,:,'-";:;..-:::.':::;"'.::::~ .::;, ".:: :,::' :.:::::,',
:::::" . ,'. .','.'. ~::.:.:;:;::;::::::: ;:;::';:::;:;:::::::;::";'- ;';':::;:;.;:;:;.::;.;:;.;: ;.;: ;':;.; ;:::':.:::,:, :;.:.:.; .
[[[";::.::
Chemical-Specific
C. To Be Considered
Materials
I Risk Assessment
Data Evaluation
Report (RADER)
for the Non-
populated Areas of
the Bun ker Hill
Superfund Site
2. Soil/Dust Lead
Contamination
Advisory
,....
"""':"';':';';';'::':';'.';.':';':':':':':';':';';'.':';'.':
::-'<:;::;:::;::;:-:::;'.:-'.:.:;......:.:.;.;...;.;.;:.
.........,.........
..................
.. .. ..... ........
. .. '" ...... ........... ..
.. ..... . ...... ...
. .......... .... ............
.. .... ...... ......... ...
"Tible'lO'1..
. .~~~!..~~A~~~'"
.......
..,
Citation
Technical
Enforcement
Contract Work
Assignment
C 10002
Prepared by:
Jacobs
Engineering
Group, Inc. and
TerraGraphics,
Inc.
Centers for
Disease
Control',s
statement on
childhood blood
lead levels,
1985.
Prerequisite
Evaluates
baseline health
risk due to
current site
exposllres and
establishes
contaminant
levels In
environmental
media at the Site
for the protection
of public health.
Removal of
contaminated
.1
SOlaS.
10-9
Requirement
The ARARs for soils
may not proyide
adequate protection
to human health;
therefore a risk
assessment approach
usmg these guidances
should be 1.lsed m
determining cleanup
levels.
Lead m soil/dust
appears to be
responsibie for blood
lead levels In
children increasing
above background
levels when the
concentrations In the
soil/dust exceed 500-
1,000 ppm. This
concentration IS
based upon the
established CDC
blood lead level of
25 J-Lg Pb/dl m
children. When
soil/dust lead
concentrations
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.
.
1~;:;G~~~t~~I~~i~ii_.fu\0S;"~
Chemical-Specific Citation .Prerequisite Requirement Location
A Applicable Toxic Substance Establishes a PCB contaminated Smelter
Requirement Control Act PCB spill pohcy material must be Complex and
40 CFR ~761, and regulates managed and MOA
Subpan G PCBs at disposed of at TSCA
concentrations of facilities.
50 ppm or
greater,
procedures for
storage and
disposal of
PCBs, and PCB-
containing
materials
B Relevant and
Appropriate
Requirement
C To Be Considered
40 CFR ~61
None
"A Guide on
Remedial
Actions at
Superfund Sites
with PCB
Contamination"
U S EP A
Directive
9355 4-0 I FS
Establishes
regulations
governmg
management and
disposal of
asbestos
Asbestos must be
removed, managed,
and disposed In
accordance with
speci tied standards.
Establishes
guidehnes for
management and
remediation of
PCB/PCB
contaminated
material
10-12
Smelter
Compi~x and
MOA
II
I
Smelter
Complex and
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.
"
II('X~:'(,"~~" "- ....
I ..."......""";';':';".",.'",:""
......
(~([J.0S . 11
:::':::i.::~:::::~::::..
.......
...... ...... .
..."..............,....
m::~18iI.~.~I.I.
Chern ical-Speci fic
Ground Water
Applicable
Requirement
B. Relevant and
Appropriate
Requirement
III
A.
C. To Be Considered
IV Surface Water
A. Applicable
Requirement
B. Relevant and
Appropriate
Requirement
1 CW A-NPDES 40 CFR
*440
C To Be Considered
V Debrisll3uildlngs
..
P'"
...
Citation Prerequisite Requirement Location
None
Safe Drinking MCLs, MCLGs, Maximum Site Wide
Water Act for arsenic, permissible level of
40 CFR *141 copper, lead, contaminant which
mercury, PCBs, may be delivered to
selenium, silver, user of public water
ZinC, and nitrate system
None
Clean Water Establishes FWQC for antimony, Onsite source
Act - FWQC 40 acceptable arsemc, beryllil,lm, contributions
CFR contaminant cadmium, copper, only and
levels for lead, ZtnC, mercury, SFCDR
I Ilnges~ion of and PC Bs tlibutaries I
I
aquatIc onslte ,
organisms and
for intake by
aquatic
orgamsms In
surface water
Discharges to
waters of U S
must meet
standards
established under
NPDES
Treatment of water
to meet new permit
reqUirements
Onsite surface
water servIces,
CIA wetland
system
program
None
-------
.
..
. ..: "':'::::::'';';::':\::'::'"'':'''
Location-Specific Citation Prerequisite Requirement Location
4. Site located within a Protection of Remedial action The remedial action WesJ Page
floodplain Floodplains, will take place will be designed to Swamp,
Executive within a 100- avoid adversely Smelterville
Order 11988; year floodplain. impacting the Flats, and
40 CFR 6, floodplain wherever Wetlands
Appendix A. . possible to ensure that System
the actjon'~ planning
and budget reflects
consideration of the
flood hazards and.
floodplain
managemen t.
5. Wetlands located in Protection of . Remedial actions The remedial action West Page
and around the site. Wetlands; may affect will be designed to Swamp and
Executive wetlands. av~id adversely Smelterville
Order 11990; impacting wetlands Flats
140 CFR 6, I wherever possible, I
Appendix A. including minimizing
wetlands destruction
and preserving
wetland values.
5a. Structures in Rivers Harbors Placement of The remedial action Site Wide
. waterways Act 33 CFR structures in will comply with
~320-330 waterways is these requirements.
restricted to pre-
approval of
Corps of
Engineers
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.
..
Location-Sped fic
1. Federal
A. Applicable
Requirement
1. Historic proje!:t owned
or controlled by a
Federal Agency
2. Site within an area
where action may
cause irreparable
harm, loss, or
destruction of artifacts.
3. Site located in area of
critical habitat upon
which endangered or
threatened species
depend.
Citation
Nationa1
Historic
Preservation
Act; 16 V.S.C.
470 ~; 40
CFR 6.301(b);
36 CFR Part
800.
Archeological
and Historic
Preservation
Act; 16 V.S.C.
469;40 CFR
6.301(c)..
Endangered .
Species Act of
1973; 16
U.S.c. 1531-
1543; 50 CFR
Parts 17. 40 I ;
40 CFR
6.302(b).
Federal
Migratory Bird
Act; 16 U.S.C.
703-712.
Prerequisite
Requirement
Property within The remedial action
areas of the Site ~ill be designed to
is included in or minimize the effect on
eligible for the historic landmarks.
National Register
of Historic
Places.
Property within
area of the Site
contains
historical and
archcologicGi
d~.~
a.Ld.
The remedial action
will be designed to
minimize the effect on
historical and
. 'archeological data.
Determination of The remedial action
presence of will be designed to
endangered or conserve endangered
threat~ned or threatened species
. species. an their habitat,
including consultation
with the Department
of Interior if such
areas are affected.
10-1 :I
Location
Site Wide
Site Wide
'I
-------
.
..
lili~i"~i~:("
Location-Sped fic
6. Waters In and around
the Site. (Continued)
7. Area containing fish
and wildlife habitat.
...
::..
',',
Fed~~'k~~~~~~~;~~C A~;~~S
"'" .. ..
.....
""...,
Citation
Fish and
Wildlife
Conservation
Act of 1980: 16
V.S.C..2901
50 CFR Part
83.
Fish and
Wildlife
Conservation
Act, 16 V.S.e.
~661 et seq.
Federal
Migratory Bird
Act, 16 use.
703
...
... .
. .....
""',".'
Prerequisite
Requirement
No discharge shall
be perm i tted that
will cause or
contribute to
~ignificant
degradation of the
w~ter.
-
-
Appropriate steps
to minimize
adverse effects
must be taken.
Determine long- and
short-term effects on
physical, chemical,
and biological
componems 01 the
aquatic ecosystem.
Activity affecting Remedial action will
wildlife and non- conserve and promote
game fish. conservation of non-
game fish and wildlife
and their habitats.
10-16
..oi;";';;;:]
Location
-------
.
..
Prerequisite
Clean Water Capping, dike
Act (Section stabilization,
404)- Dredge or construction of
Fill berms and
Requirements; levees, and
33 U.S. Co disposal of
1251-1376; 40 r.ontamina.tt".d
CFR 230, 231 soil, waste
materia] or
dredged material
are examples of -
activities that
may involve a
discharge of
dredged or fill
material.
6. .Waters in and around
the Site.
10-15
Requirement
The four conditions
that must be satisfied
. before dredge and fill
is an allowable
alternative are:
There must be no
practical
alternati ve.
Discharge of
dredged or fill
material must not
cause a violation
of State water
quality standards,
vio:ate
-------
.
4
Action-Specific
A. Applicable Requirement
1. Disposal of Solid
. Waste
Citation
RCRA 42
U.S.C. ~6901
et ~; 40 CFR
257
Prerequisite
Maintenance of -
a facility at
which solid
wastes are
disposed of.
10-18
Requirement
Facility or practices
in floodplains will
not restrict flow of
basic flood, reduce
the temporary water
storage capacity of
the floodplain or
otherwise result in
a wash-out of solid
waste.
Facility or practices
shall not cause or
contribute to taking
of any endangered
or threatened
specIes.
Facility or practices
shall not result in
the destruction or
abuse of critical
habitat.
Location
CIA, Page
Pond, and solid
-------
.
.
Location-Speci fic
B. Relevant and
Appropriate
Requirement
1. I DO-year floodplain.
Citation
None
Prerequisite
Requirement
Location
Location
Standard for
Hazardous
Waste Facilities
- RCRA; 42
U.S.C. 6901;
40 CFR
264.18(b).
RCRA hazardous
waste treatment
and disposal.
Facility located in a
lOO-year floodplain
must be designed,
constructed, operated,
and maintained to
prevent washout
during any 100-
year/24 hour flood.
Site Wide
C. To Be Considered
None
-------
.
.
Action-Specific
1. Disposal of Solid
Waste (Continued)
Citation
Prerequisite
Requirement
The concentration
of explosive gases
generated at the
facility shall not
exceed: (1) 25 % of
the lower explosive
limit for the gases
in facility
structures; (2) the
lower explosive
limit for the gases
at the boundary.
Facility or practices
shall not pose a
hazard to the safety
of j:".erSOilS or
pro~rty from fire.
Facility or practices
shall not allow
uncontrolled public
access so as to
expose the public to
potential health and
safety hazards.
10-20
Location
CIA, Page
Pond, and solid
-------
.
.
Action-Speci fic
1. Disposal of Solid
Waste (Continued)
Citation
Prerequisite
Requirement
Facility or practices
shall not cause
discharge of
pollutants into
waters of the U.S.
in violation of a
NPDES permit.
Location
CIA, Page
Pond, and solid
waste landfills
Facility' or practices
shall not cause
discharge of
dredged or fill
material into waters
of the U.S.
Facility or practices
shaH not
contamir,ate
underground
drinking source
beyond facilities
boundary.
-------
.
'.
1{;~~j1~i~J~J;~~'jil..f~.~;:flili
Action-Specific Citation Prerequisite Requirement Location
1 Removal of lOO-Contemporaneous Site Wide
contaminated soils reclamation mcluding,
(Continued) but not limited to back
regrading, topsoil
replacements at
revegetation Achieve
approximate origina!
contours, eliminate all
high spoil piles, and
depressions.
102-Achieve a post
action slope not
exceeding ang'le of
repose or such slope as
IS necessary to achieve
a long-term static
safery facLor of 1.0 to I
prevent slides i
,
-------
..
...
Action-Specific
B. Relevant and Appropriate
Requirement
1. Removal of
contaminated soils
Citation
Prerequisite
Requirement
. Location
Surface Mining
Control and
Reclamation
Act of 1977; 25
U.S.C. ~~1201
~; 30 CFR
Parts 816.11,
.95, .97. .100, ,
.102, .107,
.111, .113,
.114, .116
Removal of
contaminated
soils.
. II-Posting signs and
markers for
reclamation, including
top soil markers and
perimeter markers.
Site Wide
.9S-Stabilization of all
exposed surface areas
to effectively control
erosion pollution
attendant to erosion.
.97-Use of best
. technology currently
lavailable to minimize
disturbance, adverse
impacts on fish,
wildlife, related
environmental values
and enhancement of .
such if possible; no
activity which would.
jeopardize continued
existence of endangered
or likely destroy or
adversely effect critical
habitat; avoid habitat
disturbance & enhance
where practicable,
restore, replace,
wetlands, riparian.
vegetation habitats for
fish and wildlife.
-------
"
'.
Action-Specific
2. Threshold Limit
Values (rLVs)
(Continued)
Citation
Prerequisite
3. Treatment, Storage, or 40 CFR ,
Disposal of Hazardous 264.13, .14
Waste
The treatment,
storage, or
disposal of
RCRA
'I iegulated
wastes.
10-24
Requirement
150 ILg/m3
Lead
Mercury
alkyl == 10 ILg/m3
Except Alkyl:
vapor=50 ILg/mJ
inorganic = 100
ILg/m3
Zinc
ZnCI = 1,000 ILg/mJ
Zinc Oxide:
fume=5,OOO ILg/m3
dust= 10,000 ILg/mJ
Prevent unknowing
entry and minimize the
possibility of
unauthorized entry 'of
persons or livestock to
the active portion of
the facility. Includes:
artificial or natural
barrier completely
surrounding the
active area
a means to control
entry
a sign stating
'Danger,
UnauThorized
PeJ:\'onncl Keep
Ow'
Location
Site Wide
CIA, Page
Pond, MOA,
and
Smeltervilie
-------
.
~
Action-Sped fic
2. Threshold Limit
Values (TLVs)
Citation
Established by
American
Conference of
Governmental
Industrial
Hygienists
(ACGIH)
Prerequisite
Releases of
airborne
contaminants
during remedial
activities.
10-23
Requirement
TL V s are based on the
time weighted average
(TW A) exposure to an
airborne contaminant
over an 8-hour work
day or a 40-hour work
week. Identifylevels
of airborne
contaminants with
which health risks may
be associated. Since
there are no ARARs
for several of the
contaminants of
concern- arsemc,
antimony, copper,
c~dmium, merc~ry, I
IZlnc-the TLVs snould . I
be considered ARARs
for airborne emission
of such chemical TL VS
for the contaminants of
concern as follows:
Location
Site Wide
Antimony 500 p.g/m3
Arsenic 200 p.g/m3
Cadmium 50 p.g/m3
Copper
fume= 200 p.g/m3
-------
,
.
Action -S peci fie
8. Closure requirementS
9. Ground Wa~r
Monitoring
10. NPDES Storm Water
Discharge
II
c. To Be Cor.sidered
Materials
Citation
RCRA/HWMA
40 CFR ~264,
Subpart G
RCRA/HWMA
40 CFR ~264,
Subpan F
40 CFR Part
122.26
Prerequisite Requirement
Closure of Protectiveness will be
hazardous waste achieved through
repositories capping and
must meet institutional controls.
protective
standards.
Establishes
standards for
detection and
compliance
monitoring.
Establishes .
permitting
process and
discharge
regulations for
storm water.
10-26
Site wide monitoring
will accommodate
specific ground water
monitoring
requirements.
Relevant and
appropriate for
alternatives where min~
material comes into
contact with storm
water or si'lowmei!.
Location
CIA, Page
Pond
Smelterville
FiatS, Page
Pond, CIA,
MOA, and
Hillsides
-------
-J.
.
Prerequisite Requirement
Closure of. . Regulations to
hazardous waste minimize contaminant
repositories migration, provide
must meet leachate collection and
protective prevent contaminant
standards. exposure will be met.
RCRA/HWMA Hazardous Protectiveness will be
40 CFR ~264. waste landfil1s achieved through
Subpart N must meet capping and
minimum institutional controls.
design.
standards.
Action-Specific Citation
4. Closure Requirements RCRA/HWMA
40 CFR ~264,
Subpart G
5. Landfill Design and
Construction
6. Ground Water
. Monitoring
7. Land Disposal
Restrictions (LDRs)
RCRA/HWMA
. 40 CFR *264,
Subpart F
40 CFR *264,
Subpart X
RCRA/HWMA
40 CFR *268
Establishes
standards for
detection and
compliance
monitoring.
LORs plaee
speci fic
restrictions
(cone or trtmt)
on RCRA
hazardous
wastes prior to
their placement
in a land
disposal unit.
10-25
Site wide monitoring
will accommodate
specific ground water
monitoring
requirements.
Relevant and.
appropriate LOR
requirements will be
met if any material
accumulations are
treated ex situ.
Location
Smelter
Complex
Smelter
Complex
Smelter
Complex
Wetlaoos
System
MOA and
Smelter
-------
t
.
Action -5 peci fic
I. Estimated Limit
Values (ELVs)
(Continued)
Citation
Prerequisite
10-28
Requirement
Mercury
alkyl= 0.2 ILg/m3
Except alkyl:
vapor= 1.0 ILg/m3
inorganic =
. 2.0 ILg/m3
Zinc
ZnCI= 20.0 ILg/m3
Zinc Oxide:
fume = 120 ILg/m3
dust = 200 ILg/m3
-------
~
.
Action-Specific
1. Estimated Limit
Values (ELVs) .
Citation
Established by
American
Conference of
Governmental
Industrial
Hygienists
(ACGIH).
Prerequisite
Releases of
airborne
contaminants
during remedial
activities.
10-27
Requirement
EL Vs are based on
Threshold Limit Values
(TLVs) and converted
to reflect exposure to
contaminants on a 24-
hour/day basis. The
calculation of an EL V
does not take into
consideration the
additive and synergistic
effects of contaminants
and additional.
exposures from media
other than air. ELVs
are not expected to be
completely protective
o~ the potential em~cts I
ot exposures to
contaminants; however,
they do provide some
indication of airborne
contaminant levels at
which adverse health
effects could occur.
Since there are no
ARARs for several of
the contaminants of
concern-arseniC,
antimony, copper,
cadmium, mercury,
and zinc-the EL Vs
should be considered
TBC for remedial
activities which will
calise airborne emission
oi such chemicals.
The EL V s ior the
contaminants of
-------
.
f
Location-Specific Citation Prerequisite Requirement Location
I. Air
II. Soil
A. Applicable
Requi re!11ent
1. Areas Adjacent to IDAPA Storage or The remedial action
or in the Vicinity ~ 16.01.2800 disposal of will be designed with
of State Waters hazardous or adequate measures and
deleterious controls to ensure
materials in the stored or disposed
vicinity of, or contaminated soils will
adjacent to, not enter state waters
state waters. as ,a result of high
water, precipitation,
runoff, wind, facility
failure. accidents or
third-party activities. I
2. Preservation of LC. Property within The remedial action Site wide
Historic Sites ~ 67-4601 to areas of the Site will be designed to
4619 is included in, minimize the effect'on
the National historic landmarks.
Register of
Historic places
-------
;
~
Chemical-Specific
I. Air
A. Applicable
Requirement
1. Toxic Substances
B. Relevant and
I Appropriate
C. To Be Considered
~ II. Soil
Citation
IDAPA .
~16.01.1011,
01
None
None.
INone
Prerequisite
Emission of air
contaminants
that are toxic to
human health,
animal life, or.
vegetation.
10-29
""""""';""""';':':"';"".
Requirement
Location
Emissions of air
contaminants which
occur during remedial
activities will not be in
such quantities or
concentrations with
other contaminants,
injure or unreasonably
affect human health, .
animal life or
vegetation.
Site Wide
II
-------
_'_~.mmm"~~"',=c~~,
Action-Specific Citation Prerequisite Requirement Location
I Air
A Applicable
Requirement
I. Fugitive Dust
.
f
IDAPA
U6.01 1251-
16.01.1252
Emission of
airborne
particulate
matter.
II. Soil
A Applicable
Requirement
I. Management of
Solid Waste
.IDAPA Management of
~~16.0l 5000 et solid waste
~. including
storage,
collection,
transfer,
transport,
processing,
separation,
treatment and
disposal
10-32
The remedial action
will be designed to take
all reasonable
precautions to prevent
particulate matter from
becoming airborne
including but not
limited to, as
appropriate, the use of
water or chemicals as
dust suppressantS, the
covenng of trucks and
the prompt removal
and handling of
excavated materials.
The remedial action
wi1\ be designed to
manage solid waste to"
prevent health hazards,
public nuisances and
pollution to the
envIronment In
accordance with the
applicable solid waste
management
reqUirements No
permit IS required for
-------
.
"
Location-Specific
B. Relevant and
Appropriate
1. Siting of Hazardous I.c. ~~39-5801
Waste Disposal ~.
Facility
Citation
2. Endangered Species I.c.
* 36-201
Prerequisite
Requirement
Location
Siting of a The remedial action
hazardous waste will be designed to
disposal satisfy some of the
facility. technical criteria in the
Idaho Hazardous Waste
Siting Management
Plan as adopted by the
Idaho Legislature.
Consideration will be
given in remedy design
to general
consideration s
referenced by the
Hazardous Waste
I'FacilitY Siting Act.
However, a siting
license for an onsite
hazardous waste .
disposal facility is not
required. .
10-31
I
II
I
Determination
of presence of
endangered of
threatened
species.
Remediation will be .
designed to conserve
endangered or
threatened species, and
their habitat.
-------
~
t
Action-Specific
1. Management of
Hazardous Waste
II
I
2. Land Disposal
Restrictions
C. To Be Considered
Citation Prerequisite.
1.C. ~~39-4401 Generation,
~., IDAPA transportation,
~~16.01.5000 et storage or
gg. disposal of
hazardous
waste.
IDAPA
* 16.01.5011
None
LDRs place
specific
restrictions
(com.: or trtmt)
on RCRA
hazardous
wastes prior to
their placement
in a land
disposal unit.
10-34
. Requirement
The remedial action
. will be designed to
manage any hazardous
waste that may be
generated by the
remedial action in
ac('.()rdance with the
relevant and
appropriate generation,
transportation. storage
and disposal
requirements for such
waste. Onsite actions
are exempt from some
requirementS, and.
permitS are not
required for clIsite
activities.
Relevant and
appropriate LDR
requirements will be
met if any material
accumulations are
treated ex situ.
-------
t
.,
Action-Sped fic
2. Activities
Generating Non-
point Discharges to
Surface Waters
B. Relevant and
Appropriate
Citation
IDAPA
~U6.01.2050,
06 and
16.01.2300,04
Prerequisite
Construction
and other
activities which
may lead to
non-point
source
discharges to
surface waters.
10-33
Requirement
The remedial action
will be designed to
utilize best
management practices
or knowledgeable and
reasonable efforts in
constmction activities
to minimize adverse
water qualily impacts .
and provide full
protection or
maintenance of
beneficial uses of
. surface waters.
-------
~
.,
demolition debris. will be evaluated for reprocessing or recycling before disposal onsite.
Innovative treatment was selected for both ground and surface water in a constructed wetlands
treatment systems to remove metals. Principal Threat materials that cannot be reprocessed or
recycled will be treated by cement based stabilization. The treatment process will reduce the
mobility of the contaminants by stabilizing them in a solid matrix.
10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The selected remedy satisfies the statutory preference for treatment as a principal element.
The recycling and reprocessing of all malelials practicable, cement-based stabilization
treatment of remaining Principal Threat materials, and the treatment of both surface and
ground water in the wetlands treatment system are all principal elements of the selected
remedy. The treatment, along with the engineering controls, is consistent with the Superfund
program expectations stated in the NCP (40 CFR ~430(a)(1)(iii)(B)).
-------
f
l'
10.3 COST-EFFECTIVENESS
u.s. EPA believes the selected remedy is c.ost-effective in mitigating risks P.osed by
c.ontaminated seils, ground water, surface water, and material accumulatiens at the Bunker .HilI
Site. Secti.on 300.430(f)(ii)(D) .of the NCP requires an evaluatien .of cest-effectiveness by
c.omparing all the alternatives that meet the thresh.old criteria (pr.otectien .of human health and
the environment) against three ariditienal balancing criteria (l.ong-term effectiveness and
permanence; reductien .of texicity, m.obility, .or v.olume through treatment; and sh.ort-term
effectiveness). The selected remedy meets these criteria and prevides .overall effectiveness in
proportien te its cost.
The selected remedy includes seurce controls and treatment. Institutienal contrels will ensure
leng-term maintenance .of the physical and institutienal barriers that protect against centaminant
exposures. Tbis alternative is attractive because .of the relatively lew cest (approximately
$52.0 millien net present worth) and expected effectiveness.
The principal difference between the selected remedy and the ether twe alternatives is the.
ameunt .of treatment. One alternative relies primarily en seurce centainment. Altheugh less
expensive that the selected remedy, seurce centainment weuld previde a less effective means .of
protecting human health and the envirenment since ne water.. treatment, either surface .or
ground, is included in this alternative. Altheugh Alternative 4 weuld remeve mere
centaminated materials fer censelidatien ensite, the asseciated cest .of $120.3 millien was
sllbstantial1y higher tha:1 that far the se!e.cted remedy, the added effectiveness wauld be.
marginal with respect te the additional cost. The selected alternative was therefare determint:d
t.o be mere cost-effective.
10.4 UTILIZATION OF PERMANENT SOLUTIONS AND
ALTERNATIVE TREATMENT TECHNOLOGIES TO THE MAXIMUM
EXTENT PRACTICABLE
u.s. EPA has determined that the selected remedy represents the maximum extent ta which
permanent seluti.ons and treatment technelegies can be utilized in a cest-effective manner at the
Site. Of the three alternatives pretective .of human health and the environment and in
cempliance with ARARs, the selected remedy provides the best balance in terms .of leng term
effectiveness; implementability; and cest. Alse, the selected remedy c.onsiders the statutery
preference fer treatment as a principal element and considers cemmunity acceptance.
Long-term effectiveness was the primary reason fer selecting Alternative 3 ever Alternative 2.
The treatment included in the selected remedy provides mere permanent cantrols. The cost .of
remavals in Alternative 4 was taa high compared ta Alternative 3. censidering the associated
incremental imprevement in perfermance.
The selected remedy utilizes alternative treatment and resaurce recavery technelegies ta the
maximum extent practicable. All materials, including Principal Threat materials and
-------
,
,
12.
U.S. EPA. 1988. Guidance for Conducting Remedial Investigations and Feasibility
Studies Under CERCLA. Interim Final. October 1988. Office of Emergency and'
Remedial Response.
13.
Chapter 11 Bankruptcy Plan of Reorganization, In Re Bunker Limited Partnership. No.
91-02087Kli (July 13, 1992, D. Wash. ).
14.
Chapter II Bankruptcy Plan of Liquidation, In Re Bunker Hill Minim~ Company'
, (U.S.). Inc.. No. 91-00161 (August 22, 1991, D. Idaho).
15.
Evaluation of Institutional Controls for the Populated Areas of the Bunker Hill
Superfund Site (Draft), January 25, 1991, For Panhandle Health District by Gale Allen
and Jerry Mason.
16.
Human Health Risk Assessment Protocol For the Populated Areas of the Bunker Hill
Superfund Site, U.S. EP A Contract No. 68-01-7351, Jacobs Engineering Group, Inc., '
ICAIR, Life Systems, Inc., and TerraGraphics, Inc. (September 1989). .
17.
Interim Site ,Characterization Report for the Bunker Hill Site, U:S. EPA Contract No. '
68-01-6939, Woodward-Clyde Consultants and TerraGraphics (August 4.. 1986).'
18.
In the Matter of a Petition by the United States of America to Unseal The File in VOSS
v. Bunker Hill Company et a1.; Civ. No. 77-2030 (D. Idaho, ,Case ' No. MS-3S0S, July
2, 1990).
-------
7.
8.
9.
f
i
II REFERENCES AND ACRONYMS
All referen.ces may be found in the Administrative Record for (he Sileo or orherwise
publicly available. . .
1.
Bunker Hill Superfund Site Feasibility Study Report (FS). May I, 1992. Prepared by
McCulley, Frick, and Gilman, Inc. Volumes I, II, III, and associated Technical
Memoranda. .
2.
Bunker Hill Superfund Site Remedial Investigation Report (RI). May I, 1992.
Prepared by McCulley, Frick, and Gilman, Inc. Volumes I, II, and Ill.
3.
CH2M Hill. 1991. Residential Soil Feasibility Study for The Bunker Hill CERCLA
Site Populated Areas RIIFS (RIIFS). Document Number BHPA-RSFS-F-RO-041991.
4.
Ecological Risk Assessment for The. Bunker Hill Superfund Site (ERA). November.
1991. Prepared by Science Applications International Corporation, Technolo&y
Service Company (SAIC, 1991). . . . . .
5.
Final Human Health Risk Assessment for The Non-populated Areas of The Bunker..
Hill NPL Site (HHRA). June 1992. Prepared by Science Applications International
Corporation, Technology Services Company (SAIC, 1992). . . ... .
6.
Gott, G.B. and 1.B. Cathrall. 1980. Geochemical Expioration Studies in The Coeur
d' Alene District, Idaho and Montana. Geological Survey Professional Paper .1.l16, .
U.S. Department of Interior. U.S. Government Printing Office. WaShington D.C.
1980.
Record of Decision (ROD). Bunker Hill Mining and Metallurgical Complex
Residential Soils Operable U nit. Shoshone Coumy, Idaho. August 1991. Prepared by
Idaho Department of Health and Welfare (IDHW).
Risk Assessment Data Evaluation Report (RADER) for The Populated Areas of The
Bunker Hill Superfund Site. October 18, 1990. Prepared by Terragraphics
Environmental Engineering.
Technical Memorandum Evaluating Regulatory Requirements for The Bunker Hill Site.
June 1992. Document Number: TZ4- CIOOIO-EP-I0748.
10.
The Revised Final National Contingency Plan (NCP). April 1990.
11.
U.S. EPA. 1992.
-------
~
,
gm
HEPA
HHRA
HWMA
IC
ICN
ICP
IDAP A
IDHW
lOT
LDRs
Un. ft.
MCI
MCLs
MCLGs
MOA
mg/kg
mg/mg
m3
MTR
NAAQS
NCP
NPDES
NPL
NQ
OSWER
Pb
PCBs
PHD
ppm
PRP
PWTP
RADER
RAO
RCRA
RI
gram
High Efficiency Particulate Analyzer
Human Health Risk Assessment
Hazardous Waste Management Act
Institutional Controls
Idaho Citizens Network
Institutional Control Program
Idaho Administrative Procedures Act
Idaho Heallhand Welfare.
Idaho Department of Transportation
Land Disposal Restrictions
linear feet
Minerals Corporation of Idaho
Maximum Contaminant Levels
Maximum Contaminant Level Goals
Mine Operations Area
milligram per kilogram
. microgram per milligram
cubic meter
Minimum Technology Requirements
National Ambient Air Quality Standard
National Oil and Hazardous Substances Pollution Contingency Plan
National Pollutant Discharge Elimination System
National Priority List
Not Quanti fied
Office of Solid Waste Emergency Response
Lead
Polychlorinated Biphenyls
Panhandle Health District
parts per million
Potentiall y Responsible People
Page Water Treatment Plant
Risk Assessment Data Evaluation Report
Remedial Action Objective
Resource Conservation Recovery Act
Remedial Investigation
-------
ACGIH
ACM
ALC
AOC
ARARs
As
A TSDR
BDAT
BH
BHMC
BLP
Cd
CDC
CDFD
CDFDP
CDR
CERCLA
CFR
cfs
CIA
CMCs
CMLs
CPFs
CTP
CWA
cy
dl
DWS
ELVs
ERA
FDM
FEMA
FR
FS
FWQC
.
1
ACRONYMS AND ABBREVIATIONS
American Conference of Governmental Industrial Hygienists
Asbestos Containing Materials
Aquatic Life Criteria
Area Of Contamination
Applicability or Relevant and Appropriate Requirements
Arsenic. .
Agency for Toxic Substances and Disease Registry
Best Demonstrated Available Technology
Bunker Hill
The Bunker Hill Mining Company (U.S.), Inc.
Bunker Limited Partnership
Cadmium
Center for Disease Control
Copper Dross Flue Dust
Copper qross Flue Dust Pile
Coeur d' Alene River
Cornprehensive Environmental.Response, Compensation, and Liability Act
Code of Federal Regulations
cubic feet per second
Central Impoundment Area
Combined Metal Concentrations
Combined Metal Loadings
Cancer Potency Factors
Central Treatment Plant
Clean Water Act
cubic yard
deciliter
Drinking Water Standards
Estimated Limit Values
Ecological Risk Assessment
Fugitive Dust Model
Federal Emergency Management Act
Federal Register
Feasibility Study
Federal Water Quality Criteria
-------
i
,
RI/FS
ROD
ROW
RSFS
SAIC
SARA
SCR
SDWA
SFCDR
SPMI
sq. ft.
TCLP
TLV
TMDL
TSCA
TWA
UAO
U.S. EPA
U.S. FWS
U.S.c.
Zn
ZnCI
Remedial Investigation/Feasibility Study
Record of Decision
Rights-of-Way
Residential Soils Feasibility Study
Science Application International Applications
Superfund Amendment Reauthorization Act
Site Characterization Report
Safe Drinking Water Act
South Fork of Coeur d' Alene River
Sunshine Precious Metals, Inc.
square feet
Toxicity Characteristic Leaching Procedure.
Threshold Limit Value
Total Maximum Daily Load
Toxic Substance Control Act
Time Weighted Average
Unilateral Administrative Order
United States Environmental Protection Agency
United States Fish and Wildlife Services
United States Code
Zinc
Zinc Chloride
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