EPA Superfund
Record of Decision:
PB98-964402
EPA 541-R98-077
October 1998
California Gulch OU 4
Leadville, CO
3/31/1998
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ADMINISTRATIVE RECORD
(< •', -^ v
U U
FINAL
RECORD OF DECISION
UPPER CALIFORNIA GULCH
OPERABLE UNIT 4
CALIFORNIA GULCH SUPERFUND SITE
LEADVILLE, COLORADO
March 1998
U.S. Environmental Protection Agency
999 18th Street, Suite 500
Denver, Colorado 80202
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RECORD OF DECISION
UPPER CALIFORNIA GULCH OPERABLE UNIT 4
CALIFORNIA GULCH SUPERFUND SITE
LEADVILLE, COLORADO
The U.S. Environmental Protection Agency (EPA), with the concurrence of the Colorado
Department of Public Health and Environment (CDPHE), presents this Record of Decision
(ROD) for the Upper California Gulch Operable Unit 4 (OU4) of the California Gulch Superfund
Site in Leadville, Colorado. The ROD is based on the Administrative Record for OU4, including
the Remedial Investigation/Feasibility Study (RI/FS), the Proposed Plan, the public comments
received, including those from the potentially responsible parties (PRPs), and EPA responses.
The ROD presents a brief summary of the RI/FS, actual and potential risks to human health and
the environment, and the Selected Remedy. EPA followed the Comprehensive Environmental
Response, Compensation, and Liability Act, as amended, the National Contingency Plan (NCP),
and appropriate guidance in preparation of the ROD. The three purposes of the ROD are to:
1. Certify that the remedy selection process was carried out in accordance with the
requirements of the Comprehensive Environmental Response, Compensation, and
Liability Act, 42 U.S.C. 9601 et seq., as amended by the Superfund Amendments
and Reauthorization Act (collectively, CERCLA), and, to the extent practicable,
the National Contingency Plan (NCP);
2. Outline the engineering components and remediation requirements of the Selected
Remedy; and
3. Provide the public with a consolidated source of information about the history,
characteristics, and risk posed by the conditions of OU4, as well as a summary of
the cleanup alternatives considered, their evaluation, the rationale behind the
Selected Remedy, and the agencies' consideration of, and responses to, the
comments received.
The ROD is organized into three distinct sections:
1. The Declaration section functions as an abstract for the key information
contained in the ROD and is the section of the ROD signed by the EPA Regional
Administrator and the CDPHE Director.
2. The Decision Summary section provides an overview of the OU4 characteristics,
the alternatives evaluated, and the analysis of those options. The Decision
Summary also identifies the Selected Remedy and explains how the remedy
fulfills statutory requirements; and
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3. The Responsiveness Summary section addresses public comments received on
the Proposed Plan, the RI/FS, and other information in the Administrative Record.
Record of Decision
Upper California Gulch OU4
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DECLARATION
Record of Decision
Upper Crtforai* Gulch OU4
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DECLARATION
SITE NAME AND LOCATION
Upper California Gulch Operable Unit 4
California Gulch Superfund Site
Leadville, Colorado
STATEMENT OF BASIS AND PURPOSE
This decision document presents the Selected Remedies for waste rock and fluvial tailing
material for OU4 within the California Gulch Superfund Site in Leadville, Colorado. EPA, with
the concurrence of CDPHE, selected the remedies in accordance with CERCLA and the NCP.
This decision is based on the Administrative Record for OU4 within the California Gulch
Superfund Site. The Administrative Record (on microfilm) and copies of key documents are
available for review at the Lake County Public Library, located at 1115 Harrison Avenue in
Leadville, Colorado, and at the Colorado Mountain College Library, in Leadville, Colorado. The
complete Administrative Record may also be reviewed at the EPA Superfund Record Center,
located at 999 18th Street, 5th Floor, North Terrace, in Denver, Colorado.
The State of Colorado concurs with the Selected Remedies, as indicated by concurrence letter.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances at and from OU4, if not addressed by
implementing the response action selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
The Selected Remedies for the waste rock and fluvial tailing material is the third response action
to be taken at OU4 of the California Gulch Superfund Site. Two Engineering Evaluation/Cost
Analyses (EE/CAs) (TerraMatrix/SMI, 1995a and 1996a) were performed to identify removal
actions for the waste rock contained within the Garibaldi and the Upper Whites Gulch mine
areas. An Action Memorandum was issued by the EPA on August 4,1995, which selected the
removal actions for the Garibaldi Mine area (EPA, 1995a). On July 19, 1996, the EPA issued an
Action Memorandum which selected the removal actions for the Agwalt Mine site (EPA, 1996a).
Implementation of the Removal Action for Garibaldi Mine site was initiated during the fall of
1995, and included a portal collection system for the collapsed Garibaldi Mine portal,
approximately 1,960 linear feet of concrete-lined channel, and two groundwater interception
trenches constructed to intercept and divert surface and groundwater flow around the Garibaldi
waste rock pile. Similarly, the Removal Action conducted for the Agwalt Mine site in the fall of
1996 included a portal collection system for the collapsed Agwalt Mine portal and approximately
Record of Decision
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1,000 linear feet of concrete-lined channels to intercept and divert surface water runon and portal
flow away from the Agwalt waste rock pile. The two removal actions (Garibaldi and Agwalt) are
consistent with the Selected Remedies for the waste rock and fluvial tailing material which are
described below.
The Final Focused Feasibility Study for Upper California Gulch Operable Unit 4
(TerraMatrix/SMI, 1998) evaluated and screened remedial alternatives retained in the Site-Wide
Screening Feasibility Study (EPA, 1993) for the waste rock and fluvial tailing material within
OU4. The Focused Feasibility Study (FFS) used a comparative analysis to evaluate alternatives
for the waste rock (Garibaldi Sub-basin, Printer Girl, Nugget Gulch, AY-Minnie, Iron Hill and
California Gulch) and Fluvial Tailing Site 4 and identified the advantages and disadvantages of
each.
For the Garibaldi Sub-basin Waste Rock, EPA has selected Alternative 2: Diversion of Surface
Water and Selected Removal as the preferred alternative. Diversion ditches would be
constructed to reduce surface water runon to the UCG-109A (McDermith) waste rock pile and
reduce leaching and erosional releases associated with surface flow. The stream channel will be
reconstructed around UCG-109A.
For the Printer Girl Waste Rock, EPA has selected Alternative 4: Waste Rock Removal as the
preferred alternative. The lowermost portion of the waste rock would be excavated and
consolidated onto waste rock pile UCG-71 (Colorado No. 2). The remaining disturbed areas will
be regraded to increase stability and promote non-erosive runoff. Two diversion ditches would
be constructed to control surface water runon to the regraded disturbed areas.
For the waste rock within Nugget Gulch, EPA has selected Alternative 4: Diversion Ditches,
Consolidation, and Cover as the preferred alternative. Waste rock piles UCG-74 (Rubie), UCG-
76 (Adirondack), UCG-77 (Colorado No. 2 east), and UCG-85 (North Mike) would be excavated
and consolidated onto waste rock pile UCG-71 (Colorado No. 2). UCG-71 would be regraded
and a simple cover placed over the consolidated material. The surface material will be
revegetated or have rock placed upon it. Disturbed areas which were cleared of waste rock
would be terraced, soils amended and revegetated. Diversion ditches would be constructed to
control surface water runon.
For the AY-Minnie Waste Rock, EPA has selected Alternative 4: Diversion Ditches and Road
Relocation as the preferred alternative. Diversion ditches would be constructed to reduce surface
water runon to the AY-Minnie waste rock pile and reduce leaching and erosional releases
associated with surface flow. Lake County Road 2 will be realigned to provide area for
construction of a sediment pond and further add protection from stability failures of the timber
cribbing without destroying the mining heritage and cultural resources of this mining area.
For the was'e rock west of Iron Hill, EPA has selected Alternative 3: Regrade and Cover as the
preferred alternative. Waste rock pile UCG-12 (Mab) Castle View will be regraded. A simple
cover will be placed on UCG-12 along with revegetation of the surrounding disturbed areas. The
Record of Decision
Upper California Gulch OU4
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surface material will be revegetated or have rock placed upon it. Implementation of this
alternative will minimize infiltration at UCG-12, reduce leaching, increase stability of the
regraded waste rock and promote non-erosive runoff from the regraded waste rock pile surfaces.
For the waste rock within California Gulch, EPA has selected Alternative 2: Stream Channel
Reconstruction as the preferred alternative. The upper California Gulch stream channel would be
reconstructed and stabilized. Implementation of this alternative would stabilize the stream
channel for the 500-year flood event and reduce contact of waste rock with surface flows in
upper California Gulch, minimizing leaching and erosional releases associated with surface flow.
For the fluvial tailing within Fluvial Tailing Site 4, EPA has selected Alternative 5: Channel
Reconstruction, Revegetation, Sediment Dams, Wetlands and Selected Surface Material
Removal as the preferred alternative. The upper California Gulch stream channel would be
reconstructed and channel spoil material and selected fluvial tailings areas would be regraded and
removed (if necessary). Eight sediment dams and approximately 1.5 acres of wetlands would be
constructed along the channel. Implementation of this alternative would stabilize the site to
convey the 500-year flood event, reduce contact of surface water with fluvial tailings, promote
non-erosive flow, and minimize leaching.
The Selected Remedies are protective of human health and the environment through the
following:
1. The covers will eliminate airborne transport of waste rock particles and limit the
potential for contact of precipitation and surface water with waste material;
2. Ponding of water on the tailings surface will be minimized through selected
regarding and revegetation.
3. Infiltration through the waste rock piles will be greatly reduced due to the runon
controls and engineered covers;
4. Erosion and transport of tailings and waste rock will be eliminated or reduced by
diversion ditches and reconstructed channels;
5. Stability of the side slopes will be increased by regrading to flatten existing slopes
prior to constructing the covers.
STATUTORY DETERMINATIONS
The Selected Remedies are protective of human health and the environment, comply with federal
and state requirements that are legally applicable or relevant and appropriate to the remedial
action, and are cost effective. Given the type of waste present at this site, these remedies use
permanent solutions (e.g., diversion ditches) to the maximum extent practicable and satisfy the
preference for remedies that reduce toxicity, mobility, or volume as a principal element. Because
Record of Decision
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these remedies may result in hazardous substances remaining on site above health-based levels, a
review will be conducted within five years after commencement of remedial action to ensure that
these remedies continue to provide adequate protection of human health and the environment.
These remedies are acceptable to both the State of Colorado and the community of Leadvillc.
Max H. Dodson Date
Assistant Regional Administrator
Ecosystems Protection and Remediation
U.S. Environmental Protection Agency, Region VIII
Record of Decition
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TABLE OF CONTENTS
SECTION
1.0 SITE NAME, LOCATION, AND DESCRIPTION DS-1
2.0 HISTORY AND ENFORCEMENT ACTIVITIES DS-3
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION DS-8
4.0 SCOPE AND ROLE OF OPERABLE UNIT DS-10
5.0 SUMMARY OF SITE CHARACTERISTICS DS-12
5.1 PHYSICAL CHARACTERISTICS DS-12
5.2 NATURE AND EXTENT OF CONTAMINATION DS-13
5.2.1 GARIBALDI SUB-BASIN DS-13
5.2.1.1 Garibaldi Waste Rock Pile DS-13
5.2.1.2 Waste Rock Pile (UCG-109A and -116) DS-13
5.2.1.3 Surface Water : DS-14
5.2.1.4 Groundwater DS-15
5.2.1.5 Stream Sediment DS-15
5.2.2 WHITES GULCH SUB-BASIN DS-15
5.2.2.1 Waste Rock Piles. DS-15
5.2.2.2 Surface Water DS-16
5.2.2.3 Groundwater DS-17
5.2.2.4 Stream Sediment DS-17
5.2.3 NUGGET GULCH SUB-BASIN DS-18
5.2.3.1 Waste Rock Piles DS-18
5.2.3.2 Surface Water DS-19
5.2.3.3 Groundwater DS-21
5.2.3.4 Stream Sediment DS-21
5.2.4 AY-MINNIE SUB-BASIN DS-21
5.2.4.1 Waste Rock Pile DS-22
5.2.5 IRON HILL SUB-BASIN DS-22
5.2.5.1 Waste Rock Piles DS-22
5.2.6 FLUVIAL TAILING SITE 4 AND SOUTH AREA SUB-BASIN . DS-23
5.2.6.1 Waste Rock Piles/Fluvial Tailing DS-24
5.2.6.2 Surface Water DS-26
5.2.6.3 Groundwater DS-28
5.2.6.4 Stream Sediment DS-28
5.3 HISTORIC AND CULTURAL RESOURCES DS-28
6.0 SUMMARY OF SITE RISKS DS-31
Record of Decision
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TABLE OF CONTENTS (Continued)
SECTION PAGE
6.1 HUMAN HEALTH RISKS DS-31
6.1.1 CONTAMINANT IDENTIFICATION DS-31
6.1.2 EXPOSURE ASSESSMENT DS-32
6.1.3 RISK CHARACTERIZATION DS-33
6.2 ECOLOGICAL RISKS DS-33
6.2.1 CONTAMINANT IDENTIFICATION DS-34
6.2.2 EXPOSURE ASSESSMENT DS-34
6.2.3 RISK CHARACTERIZATION DS-35
7.0 DESCRIPTION OF ALTERNATIVES DS-37
7.1 GARIBALDI MINE SITE (UCG-121) DS-37
7.2 GARIBALDI SUB-BASIN WASTE ROCK (UCG-109A) DS-39
7.3 AGWALT (UCG-104) DS-40
7.4 PRINTER GIRL (UCG-92A) DS-41
7.5 NUGGET GULCH (UCG-71, -74, -76, -77, -79, -80, -85) DS-42
7.6 AY-MINNIE (UCG-81) DS-44
7.7 IRON HILL (UCG-12) • DS-45
7.8 CALIFORNIA GULCH WASTE ROCK (UCG-33A, -65, -75, -82A, -93,
-95 AND -98) DS-46
7.9 FLUVIAL TAILING (SITE 4) DS-48
7.10 NON-RESIDENTIAL SOILS DS-50
8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES DS-51
8.1 NCP EVALUATION AND COMPARISON CRITERIA DS-51
8.1.1 THRESHOLD CRITERIA DS-51
8.1.2 PRIMARY BALANCING CRITERIA DS-51
8.1.3 MODIFYING CRITERIA DS-52
8.2 WAMP PERFORMANCE CRITERIA DS-52
8.3 EVALUATING THE ALTERNATIVES WITH THE NCP CRITERIA
DS-55
8.3.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE
ENVIRONMENT DS-55
8.3.2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND
APPROPRIATE REQUIREMENTS (ARARs) DS-57
8.3.3 LONG-TERM EFFECTIVENESS AND PERMANENCE DS-57
8.3.4 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME
THROUGH TREATMENT DS-59
8.3.5 SHORT-TERM EFFECTIVENESS DS-60
8.3.6 IMPLEMENTABILITY DS-62
8.3.7 COST DS-63
Record of Derition
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TABLE OF CONTENTS (Continued)
SECTION PAGE
8.3.8 STATE ACCEPTANCE DS-66
8.3.9 COMMUNITY ACCEPTANCE DS-66
8.4 EVALUATING THE ALTERNATIVES WITH THE WAMP CRITERIA
-. DS-67
8.4.1 SURFACE EROSION STABILITY DS-67
8.4.2 SLOPE STABILITY DS-68
8.4.3 FLOW CAPACITY AND STABILITY DS-70
8.4.4 SURFACE WATER AND GROUNDWATER LOADING
REDUCTION DS-71
8.4.5 TERRESTRIAL ECOSYSTEM EXPOSURE DS-72
8.4.6 NON-RESIDENTIAL SOILS DS-74
9.0 SELECTED REMEDY DS-75
9.1 REMEDIES FOR THE WASTE ROCK AND FLUVIAL TAILING
WITHIN OU4 DS-76
9.1.1 REMEDY FOR THE GARIBALDI SUB-BASIN WASTE ROCK
DS-76
9.1.2 REMEDY FOR THE PRINTER GIRL WASTE ROCK DS-76
9.1.3 REMEDY FOR THE NUGGET GULCH WASTE ROCK DS-77
9.1.4 REMEDY FOR THE AY-MINNIE WASTE ROCK DS-77
9.1.5 REMEDY FOR THE IRON HILL WASTE ROCK ..: DS-77
9.1.6 REMEDY FOR THE CALIFORNIA GULCH WASTE ROCK
DS-77
9.1.7 REMEDY FOR FLUVIAL TAILING SITE 4 DS-77
9.2 CONTINGENCY MEASURES AND LONG TERM MONITORING
DS-78
10.0 STATUTORY DETERMINATIONS DS-79
10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
DS-79
10.2 COMPLIANCE WITH ARARs DS-81
10.3 COST EFFECTIVENESS DS-81
10.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE
TREATMENT TECHNOLOGIES (OR RESOURCE RECOVERY
TECHNOLOGIES) TO THE MAXIMUM EXTENT POSSIBLE DS-82
10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
DS-82
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES DS-83
Record of Decision
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TABLE OF CONTENTS (Continued)
SECTION P_A££
12.0 REFERENCES DS-84
APPENDIX A APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS (ARARs)
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LIST OF FIGURES
FIGURE
1 CALIFORNIA GULCH SUPERFUND SITE GENERAL LOCATION MAP
LEADVILLE, COLORADO
2 CALIFORNIA GULCH SUPERFUND SITE AND OPERABLE UNITS LEADVILLE,
COLORADO
3 UPPER CALIFORNIA GULCH OPERABLE UNIT 4 LEADVILLE, COLORADO
4 GARIBALDI SUB-BASIN AND VICINITY
5 WHITES GULCH AND VICINITY
6 NUGGET GULCH AND VICINITY
7 IRON HILL AND VICINITY
8 FLUVIAL TAILING SITE 4 AND SOUTH AREA
9 FLUVIAL TAILING SITE 4 FLUVIAL TAILING GEOCHEMICAL SAMPLE
LOCATIONS
10 WASTE ROCK PILE UCG-109A ALTERNATIVE 2
11 PRINTER GIRL MINE SITE ALTERNATIVE 4
12 NUGGET GULCH MINE SITE ALTERNATIVE 4
13 AY-MINNIE MINE SITE ALTERNATIVE 4
14 IRON HILL WASTE ROCK PILE UCG-12 ALTERNATIVE 3
15 CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 2
16 FLUVIAL TAILING SITE 4 ALTERNATIVE 5
Record of Decision
Upper California Gulch OU4
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LIST OF TABLES
TABLE
1 SUB-BASINS AND CONTAMINATED WASTE ROCK PILES - OU4
2 GARIBALDI SUB-BASIN WASTE ROCK GEOCHEMICAL DATA
3 SURFACE WATER COC LOADINGS
4 GEOCHEMICAL DATA FOR WASTE ROCK SOURCES IN WHITES GULCH
5 GEOCHEMICAL DATA FOR WASTE ROCK IN THE NUGGET GULCH AND AY-
MINNIE SUB-BASINS
6 WASTE ROCK PILE UCG-12 GEOCHEMICAL DATA
7 FLUVIAL TAILING SITE 4 - FLUVIAL TAILING GEOCHEMISTRY DATA
8 GEOCHEMICAL DATA FOR WASTE ROCK SOURCES SAMPLED IN FLUVIAL
SITE 4 AND SOUTH AREA
9 CULTURAL RESOURCES
10 COMPARISON OF ALTERNATIVES FOR THE GARIBALDI SUB-BASIN WASTE
ROCK - NCP CRITERIA
11 COMPARISON OF ALTERNATIVES FOR THE PRINTER GIRL WASTE ROCK -
NCP CRITERIA
12 COMPARISON OF ALTERNATIVES FOR THE NUGGET GULCH WASTE ROCK -
NCP CRITERIA
13 COMPARISON OF ALTERNATIVES FOR THE AY-MINNIE WASTE ROCK - NCP
CRITERIA
14 COMPARISON OF ALTERNATIVES FOR THE IRON HILL WASTE ROCK - NCP
CRITERIA
15 COMPARISON OF ALTERNATIVES FOR THE CALIFORNIA GULCH WASTE
ROCK - NCP CRITERIA
16 COMPARISON OF ALTERNATIVES FOR FLUVIAL TAILING SITE 4 - NCP
CRITERIA
17 COST SUMMARY: GARIBALDI SUB-BASIN WASTE ROCK ALTERNATIVE 2 -
SURFACE WATER DIVERSION, STREAM CHANNEL RECONSTRUCTION
18 COST SUMMARY: GARIBALDI SUB-BASIN WASTE ROCK ALTERNATIVE 3 -
SURFACE WATER DIVERSION, SELECTED REMOVAL
19 COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 2 - STREAM
CHANNEL RECONSTRUCTION
20 COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 3 - STREAM
CHANNEL RECONSTRUCTION AND REGRADING
21 COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 4 - WASTE
ROCK REMOVAL
22 COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 2 -
DIVERSION DITCHES
23 COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 3 -
DIVERSION DITCHES AND WASTE ROCK REGRADING
Record of Deo lion
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LIST OF TABLES (Continued)
24 COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 4 -
DIVERSION DITCHES, CONSOLIDATION AND COVER
25 COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE 2 - DIVERSION
DITCHES
26 COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE 3 - DIVERSION
DITCHES AND REGRADING
27 COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE 4 - DIVERSION
DITCHES AND ROAD RECONSTRUCTION
28 COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 2 - DIVERSION
DITCHES
29 COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 3 - REGRADING
AND COVER
30 COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 4 - WASTE ROCK
CONSOLIDATION
31 COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 2 -
CHANNEL RECONSTRUCTION
32 COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 3 -
SELECTED REGRADING
33 COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 4 -
SELECTED WASTE ROCK REMOVAL
34 COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 2 - CHANNEL
RECONSTRUCTION AND REVEGETATION
35 COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 3 - CHANNEL
RECONSTRUCTION, SEDIMENT DAMS AND WETLANDS
36 COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 4 - CHANNEL
RECONSTRUCTION, REVEGETATION, SEDIMENT DAMS AND WETLANDS
37 COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 5 - STREAM
CHANNEL RECONSTRUCTION, SURFACE STABILIZATION, SELECTED
REMOVAL, SEDIMENT DAMS AND WETLANDS
38 COMPARISON OF ALTERNATIVES FOR THE GARIBALDI SUB-BASIN WASTE
ROCK - WAMP CRITERIA
39 COMPARISON OF ALTERNATIVES FOR THE PRINTER GIRL WASTE ROCK -
WAMP CRITERIA
40 COMPARISON OF ALTERNATIVES FOR THE NUGGET GULCH WASTE ROCK -
WAMP CRITERIA
41 COMPARISON OF ALTERNATIVES FOR THE AY-MINNIE WASTE ROCK -
WAMP CRITERIA
42 COMPARISON OF ALTERNATIVES FOR THE IRON HILL WASTE ROCK -
WAMP CRITERIA
43 COMPARISON OF ALTERNATIVES FOR THE CALIFORNIA GULCH WASTE
ROCK - WAMP CRITERIA
44 COMPARISON OF ALTERNATIVES FOR THE FLUVIAL TAILING SITE 4 -
WAMP CRITERIA
Record of Decision
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LIST OF ACRONYMS AND ABBREVIATIONS
ABA
AMSL
AOC
ARD
AWQC
BARA
BMP
CD
CDPHE
CERCLA
CFS
COCs
CPT
CTE
CZL
EE/CA
EPA
ERA
ESI
FFS
HI
HQ
NCP
NPL
NRHP
OU4
PRPs
RA
RAO
RI/FS
RME
ROD
RUSLE
SFS
SHPO
SPLP
SPT
TBV
TDS
TSS
UAO
UCL
Acid-Base Accounting
Above Mean Sea Level
Administrative Order on Consent
Acid Rock Drainage
Ambient Water Quality Criteria
Baseline Aquatic Ecological Risk Assessment
Best Management Plan
Consent Decree
Colorado Department of Public Health and Environment
Comprehensive Environmental Response, Compensation and Liability Act
Cubic Feet per Second
Contaminants of Concern
Cone Penetrometer Test
Central Tendency Exposure
Colorado Zinc-Lead
Engineering Evaluation/Cost Analysis
Environmental Protection Agency
Ecological Risk Assessment
Engineering Science, Inc.
Focused Feasibility Study
Hazard Index
Hazard Quotient
National Oil and Hazardous Substances Pollution Contingency Plan
National Priorities List
National Register of Historic Places
Operable Unit 4
Potentially Responsible Parties
Risk Assessment
Remedial Action Objective
Remedial Investigation/Feasibility Study
Reasonable Maximum Exposure
Record of Decision
Revised Universal Soils Loss Equation
Screening Feasibility Study
State Historic Preservation Office
Synthetic Precipitation Leaching Procedure
Standard Penetration Test
Toxicity Benchmark Values
Total Dissolved Solids
Total Suspended Sediment
Unilateral Administrative Order
Upper Confidence Limit
Rccocd of Decision
Upper Califonu* Gulch
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LIST OF ACRONYMS AND ABBREVIATIONS (Continued)
WAMP Work Area Management Plan
WCC Woodward-Clyde Consultants
WWL Water, Waste, and Land, Inc.
Record of Deciiion
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1.0 SITE NAME, LOCATION, AND DESCRIPTION
Upper California Gulch Operable Unit 4 (OU4)
California Gulch Superfund Site
Leadville, Colorado
The California Gulch Superfund Site is located in Lake County, Colorado, in the upper Arkansas
River basin, approximately 100 miles southwest of Denver (see Figure 1). The Site encompasses
approximately 16.5 square miles and includes the towns of Leadville and Stringtown, a portion
of the Leadville Historic Mining District, and the portion of the Arkansas River from its
confluence with California Gulch downstream to the Lake Fork Creek confluence. Upper
California Gulch is a V-shaped valley with an intermittent stream that flows in a westerly
direction. California Gulch extends about 7.8 miles from its headwaters, at an elevation of about
11,300 feet above mean sea level (AMSL), to the confluence with the Arkansas River, at an
elevation of about 9,500 feet AMSL. Several sub-basins drain into upper California Gulch,
including Whites Gulch and Nugget Gulch. The California Gulch Superfund Site has been
organized into 12 operable units. Figure 2 shows the Site boundaries and the location of OU4
within the California Gulch Superfund Site.
OU4 covers an area of approximately 2.4 square miles and contains waste rock piles and fluvial
tailing and is divided into six sub-basins, as shown in Figure 3. Resurrection Mining Company
(Resurrection) identified 131 waste rock piles within OU4 (SMI/TerraMatrix, 1994a). Screening
reduced the total number of waste rock piles to 22 piles based on location, geochemistry, remote
sensing data, water quality, and physical characteristics. The total volume of waste rock
included in 22 piles identified in the screening process is approximately 431,000 cubic yards
impacting a total area of approximately 28.3 acres. Supplemental evaluation indicated that two
piles were not significant. Consequently, 20 piles were evaluated.
The deposition of fluvial tailings along upper California Gulch is neither uniform nor continuous
and the site appears to be divided into several distinct pockets. Fluvial Tailing Site 4 extends for
a distance of approximately 1.5 miles along upper California Gulch, from slightly upstream of
the Yak Tunnel portal to the upstream end of the Printer Boy Mine area. In general, the site
covers a total area of approximately 10 acres with the fluvial tailings material extending 20 to
100 feet across the valley floor. The estimated volume of fluvial tailings is 102,000 cubic yards.
The sources of metal contamination within OU4 identified in the Work Area Management Plan
(WAMP), which is an appendix to the Consent Decree (CD), include the following mine waste
rock piles and fluvial tailings material:
• Waste rock near the Garibaldi mine which may contribute to surface water and
sediment contamination;
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• Waste rock in Upper Whites Gulch which may contribute to surface water and
sediment contamination;
• Waste rock and fluvial tailings near the AY-Minnie and Printer Boy mining area
which may contribute to surface water and sediment contamination;
• Waste rock piles at North Moyer/North Mike which may contribute to surface
water and sediment contamination; and
• Mine waste rock piles located near the Minnie pump shaft extending into
California Gulch which may contribute to stream sediment contamination.
Lake County is relatively small (380 square miles) and is predominately rural, with a 1990
population of 6,007 (U.S. Department of Commerce, 1990). About half of this population
resides within the City of Leadville. The population of Lake County has fluctuated with the
mining industry. The population increased to about 9,000 between 1960 and 1981 and then
declined throughout the 1980's. About two-thirds of the land in Lake County is federally owned
and is either part of San Isabel National Forest or managed by the Bureau of Land Management.
OU4 is primarily privately owned with land surrounding and within California Gulch
predominately dedicated to mining, commercial, and residential uses (TerraMatrix/SMI, 1998).
County Road 2 parallels the Upper California Gulch drainage channel for approximately 1.5
miles from the catchment outlet to the road switchback that climbs to the topographic divide
separating California and Iowa Gulches. Several dirt roads extend from County Road 2 to
historic mine sites within OU4. These access roads are generally utilized by residents and
tourists during the summer and fall months.
The climate of Lake County is semi-arid continental, characterized by long, cold winters and
short, cool summers. The average annual maximum temperature in the Leadville area is 50.5
degrees Fahrenheit and the average annual minimum temperature is 21.9 degrees Fahrenheit,
with an annual mean temperature of 36.2 degrees Fahrenheit. The annual climatological normal
precipitation for Leadville is 18.48 inches. Prevailing winds in the Leadville are largely from the
west-northwest and to a lesser extent to the northeast, with wind speeds typically ranging from 0
to 20 miles per hour (mph). Populated areas of Leadville are predominantly upwind of OU4
(TerraMatrix/SMI, 1998).
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2.0 HISTORY AND ENFORCEMENT ACTIVITIES
The California Gulch Superfund Site is located in the highly mineralized Colorado Mineral Belt
of the Rocky Mountains. Mining, mineral processing, and smelting activities have produced
gold, silver, lead, and zinc for more than 130 years in the Leadville area. Mining and its related
industries continue to be a source of income for both Leadville and Lake County. The Leadville
Historic Mining District includes an extensive network of underground mine workings in a
mineralized area of approximately 8 square miles located around Breece Hill. Mining in the
District began in 1860, when placer gold was discovered in California Gulch. As the placer
deposits were exhausted, underground workings became the principle method for removing gold,
silver, lead, and zinc ore. As these mines were developed, waste rock was excavated along with
the ore and placed near the mine entrances. Ore was crushed and separated into metallic
concentrates at mills, with mill tailings generally slurried into tailings impoundments.
The California Gulch Site was placed on the National Priorities List (NPL) in 1983, under the
authority of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) of 1980. The Site was placed on the NPL because of concerns about the impact of
mine drainage on surface waters in the California Gulch and the impact of heavy metals loading
in the Arkansas River. Several subsequent investigations have been conducted within the
California Gulch Superfund Site that have addressed Upper California Gulch (OU4).
Resurrection entered into a Consent Decree (CD) (USDC, 1994) with the United States, the State
of Colorado (State), and other potentially responsible parties (PRPs) at the California Gulch Site
on May 4, 1994. In the CD, Resurrection agreed to perform certain remediation work in three
operable units (OU4, OU8, and OU10). The Work Area Management Plan (WAMP), included
as Appendix D to the CD (USDC, 1994), defines the scope of work to be performed by
Resurrection.
Engineering Science, Inc. (ESI) prepared the Yak Tunnel/California Gulch Remedial
Investigation (ESI, 1986) for the State. This RI evaluated the human health and environmental
impacts due to historic mining activities. Waste rock piles were selected for sampling based
upon their potential to impact surface water systems. Waste rock and fluvial tailing material
samples (from 0 to 6 inches) were collected at 14 sites in OU4. Waste rock and/or tailing
samples were collected in the Iron Hill drainage, at the Garibaldi, Agwalt, Printer Girl, and AY-
Minnie mine sites, and along Fluvial Tailing Site 4.
In 1986 and 1987, EPA conducted additional RI investigations within California Gulch and
prepared the Draft Phase II Remedial Investigation Technical Memorandum 1986-1987 (Phase II
RI)(EPA, 1989a). The Phase II RI evaluated mine-related wastes and surface water and
groundwater quality to further characterize contaminant sources at the California Gulch Site.
EPA sampled two locations in OU4 during the Phase II RI. These locations were associated with
the Printer Girl and the AY-Minnie mine sites.
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Water, Waste, and Land, Inc. (WWL) conducted a hydrologic investigation of the California
Gulch drainage for Resurrection in 1989 and prepared the California Gulch Hydrologic
Investigation, Leadville, Colorado (WWL, 1990). The study included surface water,
groundwater, and sediment sampling; laboratory analysis of samples; and an inventory of mine
and mineral waste. The primary objectives of the investigation were to characterize the surface
and groundwater quality and flow patterns, and to identify sources of contaminant loading in
California Gulch. Approximately 11 surface water samples were collected along Upper
California Gulch and its tributary drainages (Nugget Gulch and Whites Gulch). Groundwater
was sampled in the spring and fall of 1989 at monitoring wells previously installed by the EPA
in the fall of 1984.
Woodward-Clyde Consultants (WCC) conducted a site-wide surface water RI for Asarco, Inc. in
1991 and 1992. The Final-Surface Water Remedial Investigation Report (Surface Water
RI)(Golder, 1996a) describes the results of the investigation. The study involved surface water
and sediment sampling in the Arkansas River and its tributaries, including California Gulch. The
Upper California Gulch basin was sampled at one site (CG-1), located immediately upstream of
the Yak Tunnel portal.
WCC conducted a Hydrogeologic RI at the California Gulch Site for Asarco, Inc. from the fall of
1991 through the winter of 1992. The Final-Hydrogeologic Remedial Investigation Report
(Hydrogeologic RI)(Golder, 1996b) describes the results of the investigation. The study included
well and piezometer installation and monitoring, and'groundwater sampling and analysis.
Objectives of the study were to investigate groundwater quality and flow directions, evaluate
potential impacts to water users and surface water receptors, and to characterize background
groundwater quality. Four monitoring well sites (one alluvial and three bedrock monitoring
wells), two mine portals, and three springs were sampled in Upper California Gulch.
WCC conducted a remedial investigation of the five major tailing impoundments and seven
fluvial tailing deposits at the California Gulch Site for Asarco, Inc. in the fall of 1991. The
Final-Tailings Disposal Area Remedial Investigation Report (Tailings RI) was issued in 1994
(WCC, 1994a). The primary objectives of the investigation were to characterize the physical
nature of the tailing materials and to evaluate the tailing's potential impacts on surface and
groundwater. The Tailings RI included an evaluation of Fluvial Tailing Site 4 within Upper
California Gulch. Five boreholes were drilled and sampled, and 10 surface samples were
collected along the reach of Upper California Gulch extending from the Printer Boy mining area
to the Yak Tunnel portal. The 10 surface samples were composited into a single sample for
laboratory analysis. Surface water samples were also collected in conjunction with the Tailings
RI.
SMI and TerraMatrix conducted a field reconnaissance survey of waste rock piles in the Upper
California Gulch basin on behalf of Resurrection during August 1993. The Draft Final-Field
Reconnaissance Survey of Mine Waste Piles Located Within the Upper California Gulch
Drainage was issued in 1994 (SMI/TerraMatrix, 1994a). The investigation identified 131
individual waste rock piles within the Upper California Gulch basin. The survey included a field
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reconnaissance of the waste rock piles to document the physical, geographical, mineralogical,
vegetative, and potential contaminant release characteristics of each waste rock pile. As part of
the reconnaissance survey, an identification system was created to label each waste rock pile with
a unique identification number (e.g. UCG-#). Each pile was sequentially numbered from 1 to
131, beginning at the western edge of the operable unit.
Each waste rock pile was ranked for two criteria: 1) potential physical instability which may
expose or spread materials, and 2) minerals contained on the surface of the pile. Ranking of the
piles consisted of assigning a rank from 0 to 2 to each pile for each criteria based on the pile
characteristics with 0 indicating a lower potential risk and 2 indicating the highest potential risk
(TerraMatrix/SMI, 1998).
In addition to the site investigations, selected areas within OU4 were surveyed for cultural
resources in 1990,1994, and 1995. The 1990 cultural resource investigation included a survey of
the Garibaldi mine site in OU4 (Martorano, 1990). FEC conducted cultural resources surveys at
the North Moyer mine site on August 3 and 4, 1994 and June 20, 1995; at the Agwalt mine site
on July 11 an 12, 1994 and October 25,1994; and at the North Mike mine site on July 22, 1990
and July 19, 1994 (FEC, 1996). In September and October of 1995, P-III conducted a cultural
resource inventory of waste rock pile UCG-92A at the Printer Girl mine site located in Whites
Gulch and several potential access road corridors in OU4 (P-III, 1996a). In September and
October of 1995, P-III also conducted cultural resource inventories of several additional waste
rock piles and fluvial tailing areas within OU4 where remedial activities are anticipated (P-III,
1996b).
TerraMatrix and SMI, on behalf of Resurrection, conducted additional field investigation
activities within the Upper California Gulch basin during the fall of 1994. Field activities
included surface sampling of mine waste piles for geochemical analysis, a spring and seep
survey, installation of shallow groundwater monitoring wells, and the further characterization of
fluvial tailing material. Seventeen mine waste rock piles were sampled for geochemical analysis.
The primary objectives of the sampling program was to evaluate the potential risk of the waste
rock piles to generate acid rock drainage (ARD) and leach metals, and to provide supplemental
information for use in EE/CAs and the FFS.
Three shallow groundwater monitoring wells were installed as part of the groundwater
investigation. Two of the wells were installed at the Garibaldi mine site and the third was
installed at the Agwalt mine site. The wells were installed to assess groundwater conditions at
these mine sites, and to evaluate whether groundwater contributes to seepage observed at the
base of the waste rock piles (TerraMatrix/SMI, 1998).
A groundwater, surface water, and stream bed sediment field sampling program was performed
by SMI and TerraMatrix on behalf of Resurrection in October 1993; May, June and October
1994; January, May, June, July, August, and September 1995; and May, June, July, and
September 1996. The purpose of the program was to obtain additional groundwater, surface
water, and stream bed sediment data for California Gulch, its tributaries, and the Arkansas River.
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Sampling in Upper California Gulch included four groundwater monitoring wells and 28 surface
water sampling sites.
TerraMatrix, on behalf of Resurrection, conducted additional field investigation activities within
the Upper California gulch basin during the spring and fall of 1995. Field activities included
measuring surface water field parameters, surface sampling of waste rock piles, stream bed
sediment sampling, and a geotechnical investigation of selected waste rock piles. At the request
of CDPHE, additional waste rock samples were also collected by TerraMatrix at waste rock piles
UCG-109A and -116 (Garibaldi Sub-basin) during July, 1997. The objectives of the field
activities were to further define conditions within OU4 and supplement existing RI information
with additional physical, chemical, and geotechnical data to facilitate the completion of OU4
EE/CAs and the FFS.
The Garibaldi Mine Site (located in the upper most reaches of Upper California Gulch) and the
Agwalt Mine Site (located in upper Whites Gulch) were addressed through non-time critical
removal actions in the fall of 1995 and 1996, respectively. Engineering Evaluations/Cost
Analyses (EE/CAs) were prepared to identify and evaluate removal action alternatives for these
source areas (TerraMatrix/SMI, 1995a and 1996b). Action Memoranda were issued by the EPA
on August 4, 1995 for the Garibaldi mine site (EPA, 1995a) and on July 19,1996 for the Agwalt
mine site within Whites Gulch (EPA, 1996a), presenting the selected removal action alternatives.
Final Removal Action Design Reports (TerraMatrix/SMI, 1995b; TerraMatrix/SMI, 1996b) were
submitted to the EPA on August 28, 1995 for the Garibaldi mine site and on September 13, 1996
for the Agwalt mine site. Removal Action Work Plans (TerraMatrix/SMI, 1995c;
TerraMatrix/SMI, 1996c) providing implementation plans were submitted on September 8, 1995
and September 13, 1996, respectively, for the Garibaldi and Agwalt mine sites. A Removal
Action Completion report for the Garibaldi mine site and Agwalt (Resurrection, 1996) describing
the construction process, design changes, costs, and results was issued by Resurrection in
January 1996.
The selected removal actions for these locations in Upper California Gulch represent interim
responses contributing to the efficient performance of the remedial actions for OU4. As such,
these removal actions are included in the analysis of remedial alternatives presented in the FFS
report for OU4 (TerraMatrix/SMI, 1998).
In January of 1998, Resurrection submitted the Final Focused Feasibility Study for Upper
California Gulch Operable Unit 4 (TerraMatrix/SMI, 1998), according to the terms of the
Consent Decree. The FFS provided a detailed analysis for the following waste rock piles and
fluvial tailing material:
• Waste rock near the Garibaldi Mine;
• Waste rock in Upper Whites Gulch;
• Waste rock and fluvial tailing near the AY-Minnie and Printer Boy mining areas;
• Waste rock piles at North Moyer/Noith Mike; and
• Mine waste rock piles located near the Minnie pump shaft.
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A Proposed Plan describing the EPA's preferred alternatives was issued on January 15, 1998.
The preferred cleanup alternatives for the waste rock and fluvial tailing material located within
OU4 consist of:
Garibaldi Sub-basin Waste Rock: Alternative 2 - Diversion of Surface Water and Selected
Removal
Printer Girl Waste Rock:
Nugget Gulch Waste Rock:
AY-Minnie Waste Rock:
Iron Hill Waste Rock:
California Gulch Waste Rock:
Fluvial Tailing Site 4:
Alternative 4 - Waste Rock Removal
Alternative 4 - Diversion Ditches, Consolidation and Cover
Alternative 4 - Diversion Ditches and Road Relocation
Alternative 3 - Regrade and Cover
Alternative 2 - Stream Channel Reconstruction
Alternative 5 - Channel Reconstruction, Revegetation,
Sediment Dams, Wetlands and Selected Material Removal
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3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
Public participation is required by CERCLA Sections 113 and 117. These sections require that
before adoption of any plan for remedial action to be undertaken by EPA, the State, or an
individual (PRP), the lead agency shall:
1. Publish a notice and brief analysis of the Proposed Plan and make such plan
available to the public; and
2. Provide a reasonable opportunity for submission of written and oral comments
and an opportunity for a public meeting at or near the site regarding the Proposed
Plan and any proposed findings relating to cleanup standards. The lead agency
shall keep a transcript of the meeting and make such transcript available to the
public. The notice and analysis published under item #1 above shall include
sufficient information to provide a reasonable explanation of the Proposed Plan
and alternative proposals considered.
Additionally, notice of the final remedial action plan set forth in the ROD must be published and
the plan must be made available to the public before commencing any remedial action. Such a
final plan must be accompanied by a discussion of any significant changes to the preferred
remedy presented in the Proposed Plan along with the reasons for the changes. A response
(Responsiveness Summary) to each of the significant comments, criticisms, and new data
submitted in written or oral presentations during the public comment period must be included
with the ROD.
EPA has conducted the required community participation activities through the presentation of
the RJ/FS and the Proposed Plan, a 30-day public comment period, a formal public hearing, and
the presentation of the Selected Remedy in th:^ ROD. No written comments were received
during the public comment period. Verbal comments received at the public meeting are
addressed in the Responsiveness Summary.
The Proposed Plan for Upper California Gulch OU4 was released for public comment on January
15, 1998. The Rl/FS and the Proposed Plan were made available to the public in the
Administrative Record located at the EPA Superfund Records Center in Denver and the Lake
County Public Library and Colorado Mountain College Library in Leadville. A formal public
comment period was designated from January IS through February 13, 1998.
On January 29, 1998 the EPA hosted a public meeting to present the Proposed Plan for Upper
California Gulch OU4 of the California Gulch Superfund Site. The meeting was held at 7:00
p.m. in the Mining Hall of Fame in Leadville, Colorado. Representatives from the Resurrection
Mining Company presented the Proposed Plan. The alternatives were discussed for the waste
rock (Garibaldi Sub-basin, Printer Girl, Nugget Gulch, AY-Minnie, Iron Hill and California
Gulch) and the Fluvial Tailing Site 4. A portion of the hearing was dedicated to accepting formal
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oral comments from the public. Community acceptance of the Selected Remedies is discussed in
Section 8.0, Summary of Comparative Analysis of Alternatives of this Decision Summary.
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4.0 SCOPE AND ROLE OF OPERABLE UNIT
The California Gulch Superfund Site covers a wide area (Figure 2). EPA has established the
following OUs for the cleanup of geographically-based areas within the Site. The OUs are
designated as:
OU1 Yak Tunnel/Water Treatment Plan
OU2 Malta Gulch Fluvial Tailings/Leadville Corporation Mill/Malta Gulch Tailings
Impoundment
OU3 D&RGW Slag Piles/Railroad Easement/Railroad Yard and Stockpiled Fine Slag
OU4 Upper California Gulch
OUS ASARCO Smelter/Slag/Mill Sites
OU6 Starr Ditch/Penrose Dump/Stray Horse Gulch/Evans Gulch
OU7 Apache Tailings Impoundment
OUS Lower California Gulch
OU9 Residential Populated Areas
OU10 Oregon Gulch
OU 11 Arkansas River Valley Floodplain
OU12 Site Water Quality
The purpose of the Upper California Gulch OU4 RI/FS was to gather sufficient information to
support an informed risk management decision on which remedies are the most appropriate for
the sources within OU4 (waste rock piles and fluvial tailing material). The RI/FS was performed
in accordance with the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP), 40 Code of Federal Regulations (CFR) Part 300, and CERCLA Section 104,42 U.S.C. §
9604.
The objectives of the RI/FS were to:
• Characterize the physical nature of the waste rock piles, fluvial tailings material and
stream sediments, and to evaluate the potential impacts of the waste rock piles, tailings
material and stream sediments to the surface water and groundwater.
• Define the potential pathways along which metals can migrate, as well as the physical
processes and, to the extent necessary, the chemical processes that control these
pathways;
• Determine risk assessment information including potential receptors, exposure patterns,
and food chain relationships;
• Develop, screen, and evaluate remedial alternatives and predict the consequences of each
remedy;
Analyze each of the FS alternatives against the NCP (40 C.F.R. 300.430) criteria and
WAMP criteria; and
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• Compare the relative performance among each alternative with respect to the evaluation
criteria.
Based on the findings of previous investigations, the contamination at the Upper California
Gulch has been adequately delineated to evaluate alternatives in the RI/FS.
This ROD was prepared according to EPA guidance (EPA, 1989). The remedy outlined in this
ROD is intended to be the final remedial action for OU4. Preliminary qualitative remedial action
objectives (RAOs) for waste rock were developed in the SFS (EPA, 1993). The following
qualitative RAOs were presented in the Screening Feasibility Study (SFS) (EPA, 1993):
• Control wind and water erosion of waste rock materials from the source locations;
• Control leaching and migration of metals from waste rock into surface water; and,
Control leaching and migration of metals from waste rock into groundwater.
To achieve the goals of this FFS, the effectiveness of the remedial action alternatives for waste
rock were evaluated with respect to these RAOs (TerraMatrix/SMI, 1998).
The qualitative RAOs presented in the SFS for fluvial tailing include the following (EPA, 1993):
• Control erosion of contaminated materials into local water courses;
• Control leaching and migration of metals from contaminated materials into
surface water; and,
• Control leaching and migration of metals from contaminated materials into
groundwater.
The effectiveness of the remedial action alternatives for fluvial tailing were evaluated with
respect to these objectives. In addition to these RAOs, the remedial alternatives were also
evaluated with respect to the compatibility of the alternative with anticipated remedial actions in
other operable units of the California Gulch Site. This California Gulch Site-wide compatibility
was defined as controlling erosion and metal loading to surface water and groundwater that may
adversely affect other operable units, and minimizing any potential adverse effects to other
operable units caused by implementing the remedial alternative in OU4 (TerraMatrix/SMI,
1998).
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5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 PHYSICAL CHARACTERISTICS
The upper California Gulch watershed drains approximately 2.4 square miles (1,540 acres).
Major tributaries to the California Gulch within OU4 include: the reach of upper California
Gulch in the vicinity of the Garibaldi mine site (upper California Gulch upstream of Lake County
Road 2), Whites Gulch, Nugget Gulch, and gulch between Iron Hill and Carbonate Hill (Iron
Hill). Surface water flow in upper California Gulch and its tributaries is generally intermittent,
typically occurring only as the result of snow-melt runoff and high intensity summer
precipitation events.
In order to facilitate the discussion of the nature and extent of contamination within OU4, the
Operable Unit has been subdivided into the following six areas:
• Garibaldi Sub-basin;
Whites Gulch Sub-basin;
• Nugget Gulch Sub-basin;
• AY-Minnie;
• Iron Hill; and
• Fluvial Tailing Site 4 and South Area.
Five mining areas in OU4 were originally identified (in the WAMP [USDC, 1994] and other
studies [ESI, 1986; EPA, 1989a; WWL, 1990]) as containing waste rock piles that potentially
contribute to human health and environmental risks including:
Garibaldi (UCG-121);
Upper Whites Gulch (UCG-92A);
North Moyer (UCG-79) and North Mike (UCG-85);
AY-Minnie (UCG-81); and
Minnie pump shaft (UCG-75).
Additional waste rock piles identified during supplemental investigations as sources of
contamination include:
• Waste rock piles UCG-109A and -116 in the Garibaldi Sub-basin;
• Waste rock pile UCG-104 in the upper Whites Gulch drainage;
Waste rock piles UCG-71, -74, -76, -77 and -80 in upper Nugget Gulch;
• Waste rock piles UCG-12 in the upper Iron Hill drainage; and
Waste rock piles UCG-33A, -65, -82A, -93, -95, and -98 along Fluvial Tailing
Site 4.
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The sub-basins and waste rock piles identified as sources of contamination are shown in Figure
3. The surface areas and volumes for each of the waste rock piles are presented in Table 1.
5.2 NATURE AND EXTENT OF CONTAMINATION
Media evaluated include waste rock, surface water, groundwater and stream sediments within
and downgradient of OU4. The following sections summarize the nature and extent of
contamination for each of these media found within each of the six sub-basins.
5.2.1 GARIBALDI SUB-BASIN
The Garibaldi Sub-basin is the upstream most tributary basin to upper California Gulch (Figure
3). The basin is defined as the area hydraulically drained from where Lake County Road 2
crosses upper California Gulch to the topographic divide on Ball Mountain. Figure 4, Garibaldi
Mine Site and Upper California Gulch Vicinity, displays the sub-basin boundary and shows the
locations of surface water, groundwater and sediment monitoring stations. Surface water
monitoring site CG-1G is located at the catchment outlet.
Surface water flow has been measured at CG-1G fourteen times between June 1989 and
September 1996. Flow at CG-1G generally ceases in late-summer/early-fall and measured flows
ranged from 0.006 cubic feet per second (cfs) to 6.85 cfs.
5.2.1.1 Garibaldi Waste Rock Pile
The Garibaldi waste rock pile (Figure 4) is the primary source of contamination within the
Garibaldi Sub-basin. The Garibaldi waste rock pile (UCG-121) occupies two upper California
Gulch headwater channels. Waste rock is primarily coarse to fine-grained weathered porphyry
(WWL, 1990) with no vegetation present on the pile. Erosion and gullying were observed on the
waste rock pile surface (WWL, 1990). The waste rock pile reconnaissance survey identified
staining of the waste rock and noted that surface material contained greater than one percent
sulfides (SMI/TerraMatrix, 1994a). An evaluation of total metals concentrations measured in the
waste rock surface sample indicate elevated (as compared to background) concentrations of
arsenic, cadmium, and lead. A summary of the laboratory results of the metals analyses and
acid-base accounting (ABA) tests for the Garibaldi waste rock sample is presented in Table 2,
Garibaldi Sub-basin Waste Rock Geochemical Data. Analyses of EPA Method 1312 leachate
from the Garibaldi waste rock composite sample were also performed. The analyte
concentrations are presented in Table 2, and include: arsenic, 0.0015 mg/1; cadmium, 0.034
mg/1; lead, 4.59 mg/1; zinc, 6.24 mg/1; and sulfate, 345 mg/1. The pH of the leachate was 2.9
standard units (s.u.).
5.2.1.2 Waste Rock Pile fUCG-109A and -1161
In response to CDPHE's concerns that waste rock pile UCG-109A (McDermith) and -116
(Figure 4) may be potential sources of contamination, composite samples of each waste rock pile
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were collected in July, 1997. The waste rock from these piles is coarse to fine-grained porphyry
and weathered, with minor amounts of sulfides. A summary of the laboratory analyses for total
metals, ABA and EPA Method 1312 for these samples is summarized in Table 2. '
5.2.13 Surface Water
An evaluation of surface water quality data downstream of the Garibaldi mine site indicates that
the Garibaldi waste rock pile is the major contributor to surface water total suspended solids
(TSS), sulfate, and metals loading in the Garibaldi Sub-basin. Surface water runon, portal
discharge runon, and groundwater inflows upgradient of the Garibaldi waste rock pile generally
account for less than 2 percent of contaminants of concern (COC) loadings detected at sampling
station CG-1G. Prior to 1996, surface water COC loadings attributed to lateral flow from the
waste rock pile (surface water monitoring site GM-1) generally accounted for almost 100
percent, or greater, of the COC loadings detected at CG-1G (TerraMatrix/SMI, 1998).
During the fall of 1995, Resurrection completed a removal action (TerraMatrix/SMI, 1995a) at
the Garibaldi mine site. The major component of the removal action was the construction of
diversion ditches and collection systems which reduced surface water and groundwater contact
with the Garibaldi waste rock pile.
Ten water quality samples were collected from the toe of the waste rock pile (GM-1) between
June 1989 and June 1996. The pre-removal action spring flow average loadings at GM-1
accounted for: 96 percent of the sulfate loading; 1,700 percent of the dissolved arsenic loading;
205 percent of the total arsenic loading; 113 percent of the dissolved cadmium; 128 percent of
the total cadmium loading; 92 percent of the dissolved copper loading; 89 percent of the total
copper loading; 11 percent of the dissolved lead loading; 3 percent of the total lead loading; 98
percent of the dissolved zinc loading; and 96 percent of the total zinc loading of the associated
loadings detected at sampling station CG-1G. CG-1G is located downstream of the sub-basin
boundary, just below the McDermith pile (UCG-109A).
Following the Garibaldi removal action, the 1996 spring flow average loading data at GM-1
indicate a reduction in COC loadings. The post-removal action spring flow average loadings at
GM-1 generally accounted for less than two percent of the associated loadings at CG-1G.
Dissolved and total arsenic loadings are the exception, however, the percentage of the dissolved
arsenic loading from GM-1 was reduced from 1,700 percent to 11 percent and the percentage of
the total arsenic loading was reduced from 205 percent to 5 percent.
Comparison of the 1995 and 1996 data shows the decrease in loadings downstream of the
Garibaldi mine site as the result of the Garibaldi removal action. Upstream of the Garibaldi mine
site, the loading data indicates that surface water flow generally does not contribute to sub-basin
loadings. A comparison of the 1995 peak flow loadings versus the 1996 peak flow loadings
downstream of the Garibaldi mine site shows that loadings of sulfate and dissolved copper and
zinc decreased from 1995 to 1996. Surface water monitoring at the toe of the waste rock pile at
monitoring site GM-1 indicates that the Garibaldi removal action resulted in a significant
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decrease in sulfate and dissolved copper and zinc loadings attributed to lateral flow from the
Garibaldi waste rock pile. In addition, the sulfate and dissolved copper and zinc loadings at CG-
1G were reduced in half between the 1995 and 1996 peak flow events (TerraMatrix/SMI, 1998).
5.2.1.4 Groundwater
Two alluvial monitoring wells (GMW-1 and GMW-2) are located upgradient of the Garibaldi
mine site, the locations of these wells are shown in Figure 4. Groundwater samples collected
.from these wells indicated unimpacted conditions. Groundwater samples from GMW-1 and
GMW-2 had near neutral pH values (approximately 6 s.u. to 7.1 s.u.) and generally metals
concentrations, except for dissolved zinc, were at or below the analytical method detection limits.
Dissolved zinc concentrations at GMW-1 ranged from 0.13 mg/1 to 0.41 mg/1, while the
dissolved zinc concentrations detected at GMW-2 ranged from 0.03 mg/1 to 0.13 mg/1. These
monitoring wells are screened between 5 feet and 11 feet below ground surface.
5.2.1.5 Stream Sediment
The average spring flow TSS loading at CG-1G prior to the Garibaldi removal action was 1,689
Ibs/day and the post-removal action spring flow average TSS loading at CG-1G was 364 Ibs/day.
The peak flow TSS loading at CG-1G in 1995 was 9,238 Ibs/day and the 1996 peak flow TSS
loading was 1,278 Ibs/day. The water quality data from the Garibaldi Sub-basin, as monitored at
CG-1G, indicate that the Garibaldi removal action resulted in a significant reduction in the
contribution of the Garibaldi Sub-basin TSS concentrations and loads.
5.2.2 WHITES GULCH SUB-BASIN
Downstream of the Garibaldi Sub-basin, to the north of upper California Gulch, is the Whites
Gulch Sub-basin (Figure 3). Whites Gulch drains a portion of the south and south-west facing
slopes of Breece Hill. The catchment is defined as the area hydraulically drained from where
Lake County Road 2 crosses Whites Gulch to the topographic divide of Breece Hill which
separates upper California Gulch from upper Evans Gulch. The Garibaldi Sub-basin lies to the
east of the White Gulch Sub-basin, while Nugget Gulch drains the topography immediately to
the west. Figure 5, Whites Gulch and Vicinity, displays the sub-basin boundary and shows the
locations .of surface water, groundwater and sediment monitoring stations. Surface water
monitoring site WG-1 is located at the catchment outlet (TerraMatrix/SMI, 1998). Measured
flows at WG-1 ranged from 0.005 cfs to 2.4 cfs. Field observations noted that during several
OU4 low-flow sampling events there was no flow in Whites Gulch at WG-1.
5.2.2.1 Waste Rock Piles
The Agwalt (UCG-104) and Printer Girl (UCG-92A) waste rock piles (Figure 5) are the primary
sources of contamination within the Whites Gulch Sub-basin. The Agwait waste rock, pile is
primarily coarse to fine-grained, highly weathered porphyry with no vegetation present on the
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pile. The surface is highly oxidized, with greater than one percent sulfide minerals present
(SMI/TerraMatrix, 1994a).
The Printer Girl waste rock is primarily coarse to fine-grained weathered porphyry, with pyrite
and galena mineralization present (WWL, 1990). Erosion and gullying were observed on the
waste rock pile surface (WWL, 1990; SMI/TerraMatrix, 1994a).
Resurrection collected one composite sample from the Agwalt and two composite samples from
the Printer Girl waste rock pile during October 1994. A summary of the laboratory results of the
metal analyses, ABA tests, and leachate analyses using EPA Method 1312 for these samples are
presented in Table 4.
5.2.2.2 Surface Water
Eight surface water monitoring stations are located within the Whites Gulch Sub-basin. Figure 5
shows the location of the surface water sampling sites. The 1995 and 1996 peak flow loadings
and 1995/1996 spring flow average loading values for the COCs are summarized in Table 3,
Surface Water COC Loadings. The COC loadings from each headwater catchment were
expressed as a percentage of the corresponding loadings at WG-1.
Surface runoff from headwater areas in the Whites Gulch Sub-basin include:
• east Agwalt headwater catchment, monitored at surface water sampling location
AG-2E; and,
• north Agwalt headwater catchment, monitored at surface water sampling location
AG-2N.
In general the data indicate that water flowing from the east head wall catchment (AG-2E) was a
major contributor of COC loadings to Whites Gulch during 1995 and 1996, particularly for
cadmium and copper. Flow from the north head wall'catchment (AG-2N) is not a major
contributor of metals loading to Whites Gulch (TerraMatrix/SMI, 1998).
Two abandoned mine portals have been identified discharging portal flow to Whites Gulch. One
portal is located at the Agwalt mine site and the second portal is at the Printer Girl mine site.
Based on limited portal discharge data, it appears that the Agwalt portal discharge (AP-1) is a
contributor to COC loadings in Whites Gulch, especially for sulfate, dissolved cadmium and
dissolved zinc. Flow from the collapsed portal at the Printer Girl mine site is not considered a
major contributor of metal loads to Whites Gulch, however, during base flow the seepage from
Printer Girl mine site becomes a contributor to the COC loadings detected at WG-1
(TerraMatrix/SMI, 1998).
Seepage from the Agwalt waste rock pile appears to be a major contributor to COC loadings in
White Gulch. Lateral flow through the Agwalt waste rock piles has been observed from late
spring through late fall. The lateral flow through the waste rock pile emerges at the toe of the
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waste rock pile as two seeps. Monitoring station AG-1 A is the surface water sample site at the
upgradient of the two seeps, while AG-1B is the surface water site at the downgradient seep. The
lateral flow is the result of surface runon, portal discharge, groundwater inflows, and direct
precipitation infiltrating through the waste rock pile.
The base flow loadings from AG-1A accounted for less than 10 percent of the corresponding
loads at WG-1, except sulfate (22 percent) and dissolved and total zinc (13 and 12 percent,
respectively). During base flow, the percentage of the loadings at WG-1 associated with the
loading at AG-1B generally increased. The base flow average sulfate load at AG-1 B accounted
for 73 percent of the associated loading at WG-1. Dissolved cadmium, copper, and zinc base
flow loadings at AG-1B represented 32 percent, 24 percent, and 43 percent, respectively, of the
corresponding loadings at WG-1. In general the flow from the toe of the Agwalt waste rock pile
was a major contributor of sulfate and metals loading to Whites Gulch. There was no
comparison of pre- and post removal data (e.g. percent loading reduction) for the Agwalt mine
site, that evaluation is being conducted as part of the removal action.
Surface water monitoring station WG-3 is located on Whites Gulch upstream of the Printer Girl
mine site. The water quality data at WG-3 was compared against the water quality data at WG-1
to evaluate the contaminant contribution from the Printer Girl waste rock pile. The loading data
indicate that during the spring flow season, the Printer Girl waste rock piles is a major
contributor of cadmium and lead loads detected at WG-1 (TerraMatrix/SMI, 1998).
5.2.2.3 Groundwater
In August 1994, Resurrection excavated four test pits at the Agwalt mine site during a
groundwater investigation. The test pits were excavated to either the point of refusal or the
equipment limit. Water was observed in only the test pit immediately adjacent to the collapsed
portal. A groundwater monitoring well, identified as AMW-1, was installed, and groundwater
samples have been collected at AMW-1 five times between October 1994 and June 1996. The
average concentrations of TSS, sulfate, and metals of concern are generally below the average
concentrations at WG-1 (TerraMatrix/SMI, 1998).
5.2.2.4 Stream Sediment
Water quality data from Whites Gulch generally indicate that Whites Gulch is not a major
contributor to the TSS loads in upper California Gulch. The spring flow average TSS load at
WG-1 accounted for less than one percent of the spring flow average TSS load at CG-1.
However, the 1995 peak flow load at WG-1 was 9,408 Ibs/day and the associated TSS load at
WG-1 accounted for 19 percent of the detected 1995 peak flow TSS load at CG-1
(TerraMatrix/SMI, 1998).
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5.23 NUGGET GULCH SUB-BASIN
The Nugget Gulch Sub-basin is tributary to upper California Gulch immediately downstream of
the Whites Gulch Sub-basin (Figure 3). The catchment drains the east and south-east facing
aspects of Iron Hill and a portion of the south facing hillslope that separates upper California
Gulch from Stray Horse Gulch. The Nugget Gulch drainage is defined as the area hydraulically
drained from where Lake County Road 2 crosses Nugget Gulch to the topographic divide which
separates Nugget Gulch from Stray Horse Gulch and along Iron Hill. Figure 6 shows the sub-
basin boundary and the locations of surface water, groundwater and sediment monitoring
stations.
Monitoring station NG-1 is the sub-basin outlet surface water monitoring site on Nugget Gulch.
Surface flow has only been observed during the snow-melt runoff season and has been measured
ten times during the spring snow-melt season between 1989 and 1996. Measured flows at NG-1
ranged from 0.002 cfs to 1.1 cfs, and flow at NG-1 generally ceases in early- to mid-summer
(TerraMatrix/SMI, 1998).
5.2 J.I Waste Rock Piles
The primary sources of contamination found within the Nugget Gulch Sub-basin are shown in
Figure 6 and include the following waste rock piles; UCG-71 (Colorado No. 2), UCG-74
(Rubie) UCG-76, UCG-77, UCG-79 (North Moyer), UCG-80 (Moyer) and UCG-85 (North
Mike).
The waste rock at UCG-71 (Colorado No. 2) is primarily coarse-grained weathered porphyry,
with no vegetation present on the pile. The surface is highly oxidized, with greater than one
percent sulfide minerals present (SMl/TerraMatrix, 1994a). Analyses of paste pH and paste
conductivity measured in the waste rock surface sample collected from UCG-71 indicated that
the material was slightly acidic (pH of 5.8 s.u.) with a conductivity measurement of 3,450 micro
mhos per centimeter (^mhos/cm). Observations in the 1995 noted seepage from the collapsed
portal at the toe of the waste rock pile.
The waste rock at UCG-74 (Rubie) is primarily coarse-grained weathered porphyry, with less
than 10 percent of the pile covered with vegetation. The surface is moderately oxidized, with
greater than one percent sulfide minerals present (SMI/TerraMatrix, 1994a). Paste pH and paste
conductivity measurements of the waste rock surface sample collected from UCG-74 indicated
the surface material was near neutral (pH of 6.8 s.u.) with a conductivity measurement of 2,580
^mhos/cm.
The waste rock at UCG-76 and UCG-77 is primarily coarse- to fine-grained weathered porphyry,
with no vegetation present on either pile. The surfaces of both piles are moderately oxidized,
with greater than one percent sulfide minerals present (SMI/TerraMatrix, 1994a). Paste pH
measurements of waste rock piles UCG-76 and -77 surface samples indicated the surface
materials at both UCG-76 and -77 have the potential to generate ARD and leach metals, with pH
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values of 3.8 s.u. and 2.1 s.u., respectively. Paste conductivity measurements were recorded at
13,300 ^mhos/cm and 14,600 /^mhos/cm, respectively.
The waste rock at the North Mover (UCG-79) and Mover (UCG-80) mine sites is primarily
coarse- to fine-grained weathered porphyry with visible pyrite mineralization present (WWL,
1990). Erosion and gullying were observed on each waste rock pile surface (WWL, 1990;
SMI/TerraMatrix 1994a). Both waste rock piles extend into Nugget Gulch. The surfaces are
moderately oxidized, with greater than one percent sulfide minerals present (SMI/TerraMatrix,
1994a).
Resurrection collected a waste rock composite surface sample from both the North Moyer and
Moyer waste rock piles in October 1994. An evaluation of total metals concentrations indicated
elevated concentrations of arsenic, cadmium, lead, and zinc as shown in Table 5. Analyses of
leachate extracted from the waste rock composite sample using EPA Method 1312 were also
performed. The analyte concentrations for the North Moyer and Moyer waste rock pile leachates
are presented in Table 5.
The North Mike Waste Rock is primarily coarse-grained, highly weathered porphyry with no
vegetation present on the pile. The surface is highly oxidized, with greater than one percent
sulfide minerals present (SMI/TerraMatrix, 1994a). Moderate gullying exists on the waste rock
pile and in the denuded area downgradient of the waste rock pile. A collapsed shaft appears to be
located along the eastern edge of the waste rock pile. Seasonal field observations noted seepage
discharging from the toe of the waste rock pile at the downgradient edge of the denuded area
along the Nugget Gulch access road (TerraMatrix/SMI, 1998).
An evaluation of total metals concentrations measured in a North Mike waste rock surface
sample indicated elevated concentrations of arsenic, cadmium, and lead as presented in Table 5.
Analyses of leachate extracted from the waste rock sample using EPA Method 1312 were also
performed and are presented in Table 5.
5.23.2 Surface Water
Eight surface water monitoring stations are located with the Nugget Gulch Sub-basin. Figure 6
shows the location of the Nugget Gulch surface water sampling sites. The spring flow average
1995 and 1996 peak flow loading values for the COCs are summarized in Table 3. The COC
loadings from each headwater catchment were expressed as a percentage of the spring flow
average and 1995 and 1996 peak flow loadings at NG-1.
Surface runoff from headwater catchments in the Nugget Gulch Sub-basin include:
• headwater catchment, east and upgradient of the North Mike waste rock pile,
monitored at surface water sampling location NM-2; and
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• headwater catchment, east and upgradient of the North Moyer waste rock pile,
monitored at surface water sampling location NG-3.
Water quality at each of the surface water monitoring stations was compared against water
quality at NG-1, the sub-basin outlet.
In general, surface water downgradient of the North Mike waste rock pile was a major
contributor of metals loading to Nugget Gulch, particularly for sulfate and dissolved and total
cadmium, copper, and zinc. The 1995/1996 spring flow average sulfate load at NM-1
represented 22 percent of the corresponding 1995/1996 spring flow sulfate load at NG-1. The
1995/1996 spring flow average dissolved and total cadmium loadings at NM-1 accounted for 29
and 297 percent, respectively, of the associated cadmium loadings at NG-1. dissolved and total
spring flow average copper loads represented approximately 22 percent of the corresponding
copper loads at NG-1. Spring flow average loadings for dissolved and total zinc accounted for
approximately 24 percent of the corresponding zinc loadings at NG-1.
The 1996 data also indicated surface water downgradient of waste rock piles UCG-71, -74, -76,
and -77 was a contributor of metals loading to Nugget Gulch. Field water quality parameters,
including pH and specific conductivity were only measured at surface water monitoring site NC-
SA, located immediately downgradient of UCG-76. The field pH of 2.69 s.u. and conductivity
measurement of 2,200 ^mhos/cm indicate that the surface runoff downgradient of waste rock
pile UCG-76 may have contained elevated levels of metals and sulfate. A surface water sample
for laboratory analysis was collected downgradient of waste rock pile UCG-74 at monitoring site
NG-5. The 1996 peak flow measured at NG-5 accounted for less than one percent of 1996 peak
flow measured at NG-1. Consequently, the peak flow COC loadings from NG-5 generally
accounted for less than five percent of the .associated loadings at NG-1 (TerraMatrix/SMI, 1998).
The water quality data at NG-4A and NG-4B indicate that surface runoff, and potentially lateral
flow, from the North Moyer and Moyer waste rock contributes to COC loadings in Nugget
Gulch. Surface water monitoring stations NG-4A and NG-4B are located downgradient of the
North Moyer and Moyer waste rock piles. A single surface water sample was collected in June
1995 at both monitoring sites NG-4A and NG-5B.
Loading calculations were performed on the 1995 water quality data collected at NG-4A and
NG-4B. The loading values were then compared against the loading at NG-1 for that date.
Measured flows at NG-4A and NG-4B both accounted for approximately 8 percent of the flow
measured at NG-1 on that date. Sulfate loadings at NG-4A and NG-4B represented 88 and 62
percent, respectively, of the sulfate loading detected at NG-1. Metal loadings at NG-4A
accounted for: dissolved arsenic, 192 percent; total arsenic, 14 percent; dissolved and total
cadmium, 153 percent; dissolved copper, 13 percent; dissolved lead, 12 percent; total lead, 5
percent; dissolved zinc, 178 percent; and total zinc, 174 percent of the associated loadings at NG-
1. Metal loading at NG-4B represented approximately: dissolved arsenic, 1,697 percent; total
arsenic, 127 percent; dissolved cadmium, 80 percent; total cadmium, 96 percent; dissolved
copper, 26 percent; dissolved lead, 45 percent; total lead, 32 percent; dissolved zinc, 67 percent;
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and total zinc, 68 percent of the corresponding loadings detected at NG-1 (TerraMatrix/SMI,
1998).
The water quality data at NG-2 indicates that the waste rock piles at the North Moyer/Moyer, and
the North Mike, and in the vicinity of UCG-71 represent a major contributor to the metal loading
in Nugget Gulch. The spring flow average COC loadings at NG-2 generally accounted for 50 to
60 percent of the corresponding COC loadings at NG-1. In 1995, the peak flow loading at NG-2
generally represented over 100 percent of the associated peak flow loadings at NG-1. The 1995
dissolved cadmium peak flow load represented 97 percent, the 1995 dissolved copper peak flow
load represented 121 percent, the 1995 dissolved lead peak flow load accounted for 73 percent,
and the 1995 dissolved and total zinc peak flow loads represented approximately 78 percent of
the corresponding loads detected at NG-1 (TerraMatrix/SMI, 1998).
5.2.3.3 Groundwater
One Yak Tunnel bedrock monitoring well (BBW-1) is located in the northeastern comer of the
Nugget Gulch Sub-basin (Figure 6). Quarterly bedrock groundwater sampling results indicate
that this well is uncontaminated (Colder, 1996b). Although there are no alluvial monitoring
wells located in the Nugget Gulch Sub-basin, COC loadings from the seep downgradient of the
North Mike waste rock pile (NM-1) indicate that the shallow groundwater contributes to surface
water contamination in the Nugget Gulch Sub-basin.
5.2.3.4 Stream Sediment
Generally, Nugget Gulch is also not a major contributor to the TSS loads in upper California
Gulch. The average spring flow TSS load at NG-1 represents approximately four percent of the
average spring flow TSS load at CG-1. However, Nugget Gulch peak flow TSS load measured
at NG-1 during 1995 and 1996 were 5,115 Ibs/day and 3,095 Ibs/day, respectively, which
indicates that Nugget Gulch does contribute TSS to upper California Gulch surface waters
(TerraMatrix/SMI, 1998).
5.2.4 AY-MINNIE SUB-BASIN
The AY-Minnie waste rock pile, identified as waste rock pile UCG-81 during the waste rock
reconnaissance survey (SMI/TerraMatrix, 1994a), is located on the lower hillside of the south
facing slope of Iron Hill, immediately adjacent to Fluvial Site 4 (Figure 3). The AY-Minnie
mine site is generally not hydrologically connected with Nugget Gulch. However, Nugget Gulch
does flow through the eastern most portion of the AY-Minnie mine site. Figure 6 shows the AY-
Minnie Sub-basin boundary and the drainage area upgradient of the mine site. There are no
surface water, groundwater or sediment monitoring locations specifically associated with the
AY-Minnie Sub-basin.
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5.2.4.1 Waste Rock Pile
The AY-Minnie waste rock is primarily coarse-grained, highly weathered porphyry with no
vegetation present on the pile. The surface is high oxidized, with greater than one percent sulfide
minerals present (SMI/TerraMatrix, 1 994a). Erosion and moderate gullying were observed on
the waste rock pile (WWL, 1990).
Resurrection collected a waste rock surface composite sample in October 1994. total metals
concentrations measured in the waste rock surface sample indicated elevated concentrations of
arsenic, cadmium, and zinc as presented in Table 5. Analyses of leachate extracted from the
waste rock composite sample using EPA Method 1312 were also performed, and are shown in
Table 5.
5.2.5 IRON HILL SUB-BASIN
Immediately downstream of the Yak Tunnel portal, the Iron Hill Sub-basin, draining the west
slope of Iron Hill and the east slope of Carbonate Hill, discharges to California Gulch. Figure 7
shows the sub-basin boundary and the location of surface water monitoring stations. There are
no groundwater or sediment monitoring locations specifically associated with the Iron Hill Sub-
basin.
Surface water monitoring station IHW-1 is located at the catchment outlet immediately upstream
of the confluence with California Gulch. Flow at IHW-1 was monitored on six occasions in the
springs of 1 995 and 1 996. Measured flow at IHW-1 ranged from 0.2 cfs to 4 cfs. Based on the
1995 and 1996 data, flow at IHW-1 begins in early- to mid-May and ceases by late June
(TerraMatrix/SMI, 1 998). In addition, the Iron Hill sub-basin has been identified as a possible
significant contaminant source to California Gulch during snowmelt and thunderstorms.
5.2.5.1 Waste Rock Piles
The primary source of contamination found with the Iron Hill Basin as shown in Figure 7, is the
UCG-12 (Mab/Castle View) waste rock pile.
The UCG-12 waste rock pile is located in the upper reach of the Iron Hill drainage, on the
northeast slope of Carbonate Hill just below the topographic divide that separates the Iron Hill
drainage from Stray Horse Gulch, and it is approximately 2,500 feet upstream of Lake County
Road No. 2. The waste rock at UCG-12 is primarily coarse-grained weathered porphyry, with
limited vegetation present on the pile. The surface is highly oxidized, with greater than one
percent sulfide minerals present (SMI/TerraMatrix, 1994a).
Resurrection collected a waste rock surface composite sample in October 1994. An evaluation of
total metals concentrations measured in the waste rock surface sample indicated elevated
concentrations. Total concentrations of arsenic, cadmium, lead, and zinc, ABA test results, and
leachate analyses using EPA Method 1312, are presented in Table 6.
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Three surface water monitoring stations are located in the Iron Hill Sub-basin. Figure 7 shows
the location of the Iron Hill surface water sampling stations. The spring flow average and 1995
and 1996 peak flow loading values for the COCs are summarized in Table 3. The COC loadings
from the headwater catchment (IHW-3) is expressed as a percentage of the spring flow average
and 1995 and 1996 peak flow loadings at IHW-1.
Tributary inflows to the Iron Hill Sub-basin have been observed during 1995 and 1996 from
OU6 along a historic road grade in the vicinity of waste rock pile UCG-86. The waste rock pile
is located immediately north of the topographic divide which separates the Iron Hill catchment
from Stray Horse Gulch located in OU6. Resurrection collected a single surface water sample in
1996, identified as IHW-3, downgradient of UCG-86 where the flow entered the Iron Hill
drainage. Loading values calculated at IHW-3 indicates that surface runoff from OU6
contributed to COC loadings in the Iron Hill drainage during 1996. The TSS loading at IHW-3
accounted for 234 percent of the TSS loading detected at IHW-1. Metal loadings at IHW-3
generally accounted for 30 to 45 percent of the associated constituent loading at IHW-1. The
dissolved and total copper loadings at IHW-3 represented 86 and 84 percent, respectively, of the
associated copper loadings at IHW-1 (TerraMatrix/SMI, 1998).
A single surface water sample has been collected downgradient of the two identified waste rock
contaminant sources in the Iron Hill catchment. Surface water monitoring site IHW-2 is located
downstream of the flow paths which convey surface runoff from waste rock pile UCG-12. The
loadings for the May 1996 IHW-2 sample were expressed as a percentage of the associated .
loadings on that day at IHW-1.
With the exception of arsenic which was reported as below the analytical detection limit and total
lead, COC concentrations at IHW-2 for the May 1996 sample were generally slightly elevated
when compared to the corresponding sample at IHW-1. The flow measurement at IHW-2
accounted for 26 percent of the flow measured at IHW-1. However, the data does not
differentiate if the contaminant concentrations and corresponding loadings at IHW-2 can be
attributed to surface runoff from OU6 or to surface runoff from either waste rock pile UCG-12 or
UCG-54 (TerraMatrix/SMI, 1998).
5.2.6 FLUVIAL TAILING SITE 4 AND SOUTH AREA SUB-BASIN
The Fluvial Tailing Site 4 and South Area Sub-basin drains the hillslope which separates OU4
from Iowa Gulch and includes the reach of upper California Gulch stretching from the Yak
Tunnel portal to monitoring station CG-1G. While the topography to the north of Fluvial Tailing
Site 4 is generally defined by a series of tributary drainages, the portion of OU4 to the south of
Fluvial Tailing Site 4 is generally not defined by tributary drainages. Eureka Gulch, which
separates Printer Boy Hill and Rock Hill is the only well defined South Area tributary drainage.
In addition to the identified tributary drainages, flow has been observed discharging to upper
California Gulch from three springs located along the main reach of upper California Gulch
(TerraMatrix/SMI, 1998). Figure 8 shows the sub-basin boundary and the locations of surface
water, groundwater and sediment monitoring stations.
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The downstream outlet of the OU4 watershed is defined as the Yak Tunnel portal (USDC, 1994).
Surface water monitoring site CG-1 is located on upper California Gulch immediately upstream
of the Yak Tunnel portal. Flow at CG-1 varies from year to year, but generally flow begins in
early May, peaks around the beginning of June, and ceases in late summer.
5.2.6.1 Waste Rock Piles/Fluvial Tailing
The primary sources of contamination found within the Fluvial Tailing Site 4 and South Area are
shown in Figure 8 and include Fluvial Tailing Site 4 and the following waste rock piles; UCG-
33A, UCG-65, UCG-75 (Minnie Pump Shaft), UCG-82A, UCG-93, UCG-95 and UCG-98
(Lower Printer Boy).
Fluvial Tailing Site 4 extends for a distance of approximately 1.5 miles along upper California
Gulch, from slightly upstream of the Yak Tunnel portal to the upstream end of the Printer Boy
mine area. The total volume of fluvial tailings and fluvial tailings intermixed with alluvial
sediments within Fluvial Tailing Site 4 is estimated to be 102,000 cy.
Fluvial tailings and mixed tailings/alluvium thickness at Fluvial Tailing Site 4 range from less
than 1 foot to 16 feet with alluvial sands, gravels, and cobbles and organic soils underlying the
fluvial tailings. Grain sizes of the fluvial tailings material typically range from fine- to coarse-
grained sands. Vegetation on the fluvial tailings is limited with approximately 75 percent of the
fluvial site unvegetated. The remaining 25 percent is vegetated with grasses and lodgepole pine;
wetlands exist along the upper California Gulch channel within Fluvial Tailing Site 4
(TerraMatrix/SMI, 1998).
Several investigations collected fluvial tailing samples which were submitted for geochemical
analysis. Geochemical samples were also collected from the five boreholes drilled in October
1991 as part of the Tailings RI (WCC, 1994a). In addition, one surface composite sample was
obtained from 10 locations along the site during the RI investigation (WCC, 1994a).
Resurrection collected surface soil samples at four locations within Fluvial Tailing Site 4,
downstream of the AY-Minnie, in 1994 in conjunction with the OU4 terrestrial ecological risk
assessment (Stoller, 1996). The locations where fluvial tailings samples were collected for
geochemical analysis are shown on Figure 9. Metals concentrations measured in fluvial tailing
samples collected during the Tailing RI indicate elevated concentrations. Arsenic, cadmium,
copper, lead, and zinc total metals concentrations were elevated in the surficial tailings sample.
Arsenic, cadmium, lead, and zinc concentrations were generally elevated in subsurface tailing
samples. Foundation soils beneath the tailings material contained elevated concentrations of
cadmium, lead, and zinc (WCC, 1994a). A summary of the Tailings RI (WCC, 1994a) metals
analysis laboratory results are presented in Table 7.
The UCG-33A waste rock is primarily coarse-grained, highly weathered porphyry with limited
vegetation present on the pile. The surface is moderately oxidized, with no visible sulfide
minerals present (SMI/TerraMatrix, 1994a). The waste rock pile reconnaissance survey
indicated considerable staining of the UCG-33A waste rock pile.
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The UCG-65 waste rock is primarily coarse-grained, weathered porphyry with limited vegetation
present on the pile. The surface is moderately oxidized, with less than one percent sulfide
minerals present (SMI/TerraMatrix, 1994a). Resurrection collected a waste rock surface
composite sample in October 1994. An evaluation of total metals concentrations indicate
elevated concentrations of arsenic, cadmium, lead, and zinc as presented in Table 8. Analyses of
leachate extracted from the waste rock composite sample using EPA Method 1312 were also
performed, and are presented in Table 8.
The waste rock pile UCG-75 (Minnie Pump Shaft) is primarily coarse to fine-grained, highly
weathered porphyry with limited vegetation present on the pile. The surface is highly oxidized,
with greater than one percent sulfide minerals present (SMI/TerraMatrix, 1994a). Resurrection
collected a waste rock surface composite sample irr October 1994. An evaluation of total metals
concentrations indicated elevated concentrations of arsenic, cadmium, lead, and zinc as presented
in Table 8. Analyses of leachate extracted from the waste rock composite sample using EPA
Method 1312 were also performed and are presented in Table 8.
The UCG-82A waste rock is primarily coarse-grained, highly weathered porphyry with limited
vegetation present on the pile. The surface is high oxidized, with greater than one percent sulfide
minerals present (SMI/TerraMatrix, 1994a). Staining of the waste rock and adjacent,
downgradient areas was observed during several OU4 field investigations.
The UCG-93 waste rock is primarily coarse to fine-grained, high weathered porphyry with no
vegetation present on the pile. The surface is highly oxidized, with less than one percent sulfide
minerals present (SMI/TerraMatrix, 1994a). Staining of downgradient adjacent areas was
observed during OU4 field investigations.
The UCG-95 waste rock is primarily coarse to fine-grained, weathered porphyry with limited
vegetation on the pile. The surface is moderately oxidized, with less than one percent sulfide
minerals present (SMI/TerraMatrix, 1994a). Staining of the waste rock and adjacent areas was
not observed during OU4 field investigations.
The UCG-98 waste rock is primarily coarse to fine-grained, highly weathered porphyry with
limited vegetation present on the pile. The surface is highly oxidized, with less than on percent
sulfide minerals present. Staining of the waste rock and adjacent areas was minimal during OU4
field investigations. The toe of the waste rock pile intercepts the upper California Gulch channel.
An evaluation of total metals values measured in the waste rock surface samples collected during
October 1994 indicate concentrations are not elevated with the exception of cadmium and lead.
Total metal concentrations, EPA Method 1312 leachate analyses, and ABA test results are
presented in Table 8.
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5.2.6.2 Surface Water
Several surface water monitoring sites were established along Fluvial Tailing Site 4 to allow for
the evaluation of changes in water quality and flow through the main reach of upper California
Gulch. The monitoring stations are generally located upstream and downstream of major
tributary catchment inflows and Fluvial Tailing Site 4 source areas. Figure 8 shows the locations
of the monitoring sites located along the main reach of upper California Gulch. Tributary inflow
surface water monitoring sites are also shown on Figure 8.
Three surface water monitoring locations (CG-1C, CG-1D and CG-1E) were established along
the main reach of upper California Gulch between CG-1G, the monitoring site which serves as
the outlet from the Garibaldi Sub-basin, and CG-1, the OU4 watershed outlet where OU4
discharges to OU8. These three monitoring sites and CG-1G provide control points along
Fluvial Tailing Site 4 upstream and downstream of contaminant source areas and tributary
inflows. The spring flow average and the 1995 and 1996 peak flow loading values for the COCs
are summarized in Table 3, Surface Water COC Loadings. The COC loadings from each
monitoring site were expressed as a percentage of the spring flow average and 1995 and 1996
peak flow loadings at CG-1.
The three surface water monitoring stations are located along Fluvial Tailing Site 4 and include:
• Surface water sampling location CG-1C, located downstream of the Printer Boy
mining area and upstream of Whites Gulch;
• Surface water sampling location CG-1D, located downstream of Whites Gulch
and upstream of Nugget Gulch and the AY-Minnie mine site; and,
• Surface water sampling location CG-1 E, located downstream of the AY-Minnie
mine site and approximately 1,700 feet upstream of CG-1.
Water quality samples have been collected at CG-1C seven times between October 1991 and
September 1996. The spring flow measured at CG-1C accounts for approximately 69 percent of
the spring flow measured at CG-1. The CG-1C spring TSS flow average loading accounts for 18
percent of the spring flow average TSS loading detected at CG-1. The spring flow average
sulfate load at CG-1C represents 41 percent of the sulfate load at CG-1. Spring flow average
loadings of cadmium, copper, and zinc at CG-1C represent between 19 percent to 35 percent of
the corresponding metals spring flow average loadings detected at CG-1 (TerraMatrix/SMI,
1998).
Water quality samples have been collected at CG-1D five times between June 1989 and June
1996. The spring flow measured at CG-1D accounts for approximately 88 percent of the spring
flow measured at CG-1. The CG-1 D spring flow average TSS loading accounts for 24 percent of
the spring flow TSS loading detected at CG-1. The sulfate load at CO-ID represents 64 percent
of the sulfate load at CG-1. Spring flow average loadings of cadmium at CG-ID represents 31
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percent and 28 percent of the corresponding dissolved and total cadmium loadings detected at
CG-1. The spring flow average dissolved and total copper loadings at CO-ID accounted for 69
percent and 54 percent of the associated copper loadings at CG-1. Lead loadings at CG-1D,
while less than ten percent of the lead loadings at CG-1 were three to four times greater at CG-
1D than the corresponding lead loadings at CG-1C. The spring flow average zinc loadings at
CG-1D represented 37 percent and 33 percent of the corresponding spring flow dissolved and
total zinc loading detected at CG-1 (TerraMatrix/SMI, 1998).
Water quality samples have been collected five times at CG-1E between June 1989 and July
1996. The spring flow measured at CO-IE accounts for approximately 112 percent of the spring
flow measured at CG-1. Also, the 1995 and 1996 peak flows measured at CG-1E represented
106 and 117 percent of the corresponding peak flows measured at CG-1. The flow data indicate
that upper California Gulch between CG-1E and CG-1 may be a losing system. The CG-1E
spring flow average TSS loading accounts for 37 percent of the spring flow average TSS loading
detected at CG-1. The spring flow average sulfate load at CG-1E represents approximately 90
percent of the spring flow average sulfate load at CG-1. Spring flow loadings of cadmium at
CG-IE represents 61 percent and 53 percent of the corresponding spring flow average dissolved
and total cadmium loadings detected at CG-1. The average spring flow dissolved and total
copper loadings at CG-1E accounted for 93 percent and 75 percent of the associated copper
loadings at CG-1. Lead loadings at CG-1E represented 31 and 11 percent of the corresponding
dissolved and total lead loadings at CG-1. The spring flow average zinc loadings at CG-1D
represented 66 percent and 63 percent of the corresponding springs flow average dissolved and
total zinc loading detected at CG-1 (TerraMatrix/SMI, 1998).
Inflows to the main reach of upper California Gulch include:
• Garibaldi Sub-basin, monitored at surface water sampling location CG-1 G;
• Eureka Gulch, a South Area tributary gulch, monitored at EUG-1;
• Whites Gulch Sub-basin, monitored at surface water sampling station WG-1;
• Nugget Gulch Sub-basin, monitored at surface water sampling station NG-1; and,
• Iron Hill Sub-basin, monitored at surface water sampling site IHW-1.
Inflow water quality at the tributary catchment outlets were compared to water quality at CG-1.
The COC loadings from each tributary catchment outlets was compared to the water quality at
CG-1.
A comparison of pre-removal action and post-removal action water quality data indicate that the
Garibaldi removal action resulted in an improvement in water quality leaving the Garibaldi Sub-
basin. Whites Gulch is a major contributor to upper California Gulch surface water sulfate and
copper loadings. Concentration and loading data for Nugget Gulch indicate that Nugget Gulch is
a major contributor to upper California Gulch surface water contamination, especially for sulfate
and metals. Average metals concentrations at NG-1 are generally two to four times greater than
the concentrations measured at CG-1. While the percentage of flow at CG-1 attributed to Nugget
Gulch is less than 10 percent, the average COC loadings from Nugget Gulch generally account
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for 17 percent to 82 percent of the loading detected at CG-1. Surface water from the Iron Hill
drainage also contributes to California Gulch surface water contamination. Landscapes
upgradient of historic mine activities do not appt to contribute to OU4 COC loadings
(TerraMatrix/SMI, 1998).
5.2.63 Groundwater
Groundwater inflows to the main reach of upper California Gulch have been observed from three
springs, SPR-15, -17, and -18. Field observations indicate that the springs flow from late spring
through late fall. Figure 8 shows the locations of the three springs. Water quality at the three
springs was compared against the water quality at CG-1.
In general, the COC concentrations detected from the three springs are less than the COC
concentrations detected at CG-1. In addition, the average flow from the springs accounts for less
than one percent of the average flow measured at CG-1. Groundwater inflow was not a major
contributor of metals loading to the main reach of upper California Gulch (TerraMatrix/SMI,
1998).
5.2.6.4 Stream Sediment
Stream sediment geochemistry samples for laboratory analyses were collected at selected water
monitoring sites in OU4 in 1989, these samples were analyzed for total metals concentrations.
The following observations were made following analysis of laboratory results from the 1989
sediment sampling episode:
• Total metals concentrations in stream sediments from tributary catchments, as
measured at surface water sampling site CG-1G, WG-1, and NG-1, were generally
less than total metals concentrations measured at CG-1;
• Total metals concentrations from the Garibaldi Sub-basin, as measured at CG-1 G,
were generally high than corresponding total metals concentrations measured at
WG-1 or NG-1;
• The highest total arsenic concentrations in OU4 stream sediments were measured
immediately downstream of the Garibaldi mine site; and,
• Total metals concentrations in the stream sediment samples increased in a
downstream direction along the main reach of upper California Gulch.
5.3 HISTORIC AND CULTURAL RESOURCES
Historic sites considered eligible for listing on the National Register of Historic Places or
contributing to the Leadville Historic District are indicated in Table 9. The sites listed in Table 9
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were identified after consultation with the Colorado State Historical Preservation Officer
(SHPO). The table also indicates which sites may be adversely affected by the remedial action.
Avoidance and minimization of adverse effects to historic properties was considered during the
remedy selection process. A Cultural Resources Plan will be developed during the remedial
design.
Cultural resource inventories were performed for areas within OU4 where remedial action may
occur. The inventories were conducted by P-III Associates, Inc. on behalf of Resurrection
Mining Company in order to assist the company in fulfilling its responsibilities under Section
106 and Section 110(f) of the National Historic Preservation Act (NHPA). The specific
mechanisms for fulfilling these responsibilities are identified in the "First Amended
Programmatic Agreement among the U.S. EPA, the Advisory Council on Historic Preservation,
and SHPO regarding the California Gulch Superfund Site, Leadville, Colorado". This amended
Programmatic Agreement was executed in 1994.
The inventory reports contain information about sites identified as having historical significance.
Site surveys were performed in these areas in accordance with the Identification and Evaluation
Plan (Martorano et al.1994). Individual sites were identified that were considered either eligible
for the National Register of Historic Places or contributing to the Leadville Historic District.
The Lake County Historic Preservation Board, SHPO, and other interested parties were offered
the opportunity to comment on all inventory reports. All comments were considered in
analyzing the inventory reports and are reflected in Table 9. The table represents the final
determination of historical significance for each site. However, changes to these designations
may be made at a later date if additional information is discovered.
As cleanup alternatives in the Focused Feasibility Study were developed, consideration was
given to avoid or minimize adverse effects to landscape features that may present historical
significance. The alternatives provided for varying levels of adverse affects to the historical
properties. By complying with the NHPA, potential adverse affects to historical properties were
evaluated when determining which alternative would be the preferred remedy. In addition to
evaluating the potential for adverse effects, criteria such as cost and the ability of the alternative
to offer protection to human health and the environment were also evaluated against each
alternative. Some alternatives were rejected from further consideration if the alternative did not
provide for acceptable protection of human health and the environment. All the criteria used in
the remedy selection process are identified in Section 8 of this ROD.
The preferred remedy was then identified in the Proposed Plan. The public was offered a 30-day
period to comment on the Proposed Plan. SHPO was also offered an additional comment period.
Recommendations from the public and SHPO were taken into account when making the final
remedy selection as described in this ROD.
The Cultural Resources Plan will describe efforts to avoid, minimize, and mitigate for adverse
effects to historic sites. If adverse effects to historical properties are unavoidable, any needed
mitigation efforts will depend upon the historical significance and importance of the site affected.
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Mitigation is not needed in many situations because alternatives were selected that would avoid
adverse effects to historic properties. For example, instead of regrading the site, surface water
diversions will be constructed around the A-Y Minnie area to minimize surface water contact
with mine waste, avoiding adverse effects. However, some historic properties will be adversely
affected. Efforts to mitigate adverse effects due to cleanup activities will be required. A Cultural
Resources Plan will be developed during the remedial design phase of the project. SHPO will be
offered the opportunity to comment on the draft plan as well as the design. A final plan will be
developed in consultation with SHPO.
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6.0 SUMMARY OF SITE RISKS
Baseline human health and ecological risk assessments (RAs) characterize potential site risks
present at a site if no action were taken. The presence of human health or ecological risks
provides the basis for remedial action; the RA indicates the media and exposure pathways to be
addressed. RA information describing exposure pathways, contaminants, and potential risks at
OU4 is summarized below.
6.1 HUMAN HEALTH RISKS
Human health RAs pertinent to OU4 consist of the following:
Weston. 1995a. Baseline Human Health Risk Assessment for the California Gulch Superfund
Site. Part C. Evaluation of Recreational Scenarios.
Woodward-Clyde Consultants (WCC). 1994a. Final - Tailings Disposal Area Remedial
Investigation Report, California Gulch Site, Leadville, Colorado.
Woodward-Clyde Consultants (WCC). 1994b. Final - Mine Waste Pile Remedial Investigation
Report, California Gulch Site, Leadville, Colorado.
A brief summary of these RAs is presented below, including contaminant identification
information, exposure assessment information, and risk characterization results. Although
information presented in all three reports (Weston 1995a; WCC 1994a; and WCC 1994b) was
reviewed and is summarized below, decisions presented in this ROD are based only on
information presented in Weston (1995a) prepared by EPA. Conclusions presented in WCC
(1994a and 1994b) did not constitute the basis for risk management decisions.
6.1.1 CONTAMINANT IDENTIFICATION
In response to concerns raised by Leadville officials and business leaders, EPA committed to
performing an "expedited" risk assessment to quickly determine whether environmental
contamination was of concern at commercial, industrial, or recreational areas. The results of the
expedited risk assessment are presented in Weston (1995a). Weston (1995a) evaluates risks
resulting from recreational exposure to contaminated surface soils (i.e., to depths of 6 inches
below ground surface). Exposures to other media (e.g., waste piles and surface tailings) are
considered to be minimal (Weston 1995a). This assumption is corroborated by results of WCC
(1994a) and WCC (1994b) which evaluate risks to recreational users from exposure to surface
tailings (0-2 inches) and waste piles (0-2 inches), respectively.
Arsenic and lead were used as indicator contaminants for risk (Weston 1995a). Selection of
these chemicals was based on the results of preliminary RAs (WCC 1994b, Weston 1991) which
indicated that arsenic and lead are responsible for the majority of human health risks at the Site.
The Weston (1991) report evaluates risks to residents and workers, hence, it is not discussed
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herein other than in terms of contaminant selection in the later Weston (1995a) report. The WCC
(1994a) report provides cumulative risk estimates from exposure to all contaminants.
Contaminants evaluated in the tailings RA (WCC 1994a) consisted of antimony, arsenic,
beryllium, cadmium, chromium (VI), copper, lead, manganese, and zinc. The waste rock RA
(WCC 1994b) evaluated health risks resulting from exposure to arsenic, cadmium, copper, lead,
manganese, silver, and zinc.
Chemical concentrations in waste rock and tailings are discussed in Section 5.2, Nature and
Extent of Contamination. Surface soil concentrations of lead and arsenic are discussed in the
Weston (1995a) RA; the RA noted that average lead concentrations in and around Leadville are
generally below 7,000 mg/kg (Weston 1995a). Average arsenic concentrations generally do not
exceed 50 mg/kg in the main section of Leadville and do not exceed 1,400 mg/kg anywhere at
the Site (Weston 1995a).
6.1.2 EXPOSURE ASSESSMENT
Residential, commercial, and industrial uses do not occur in OU4, nor are these uses anticipated
to occur in the future at OU4. Therefore, commercial workers, industrial workers, and residents
are not exposed to contaminated media in OU4. Recreation is the most likely land use scenario
for OU4. Therefore, recreational visitors were selected as the receptors of concern for OU4
(WCC 1994a, WCC 1994b, Weston 1995a).
Each RA selected exposure pathways through which receptors were most likely to contact
contaminated media. Both the tailings RA (WCC 1994a) and the waste rock RA (WCC 1994b)
evaluated health risks to visitors and recreational users through ingestion and inhalation of
contaminated media. The Weston (1995a) RA determined that, although several pathways were
complete, ingestion of soil was the only significant exposure pathway. Therefore, Weston
(1995a) only evaluated risks associated with ingestion of soil during recreational activities.
In both the tailings and waste rock RAs, WCC (1994a, 1994b) used the 95th percent upper
confidence limit of the arithmetic mean (95% UCL) as the contaminant exposure point
concentration to calculate the reasonable maximum exposure (RME). RME is defined as an
exposure well above the average but within the range of those possible (EPA 1992). WCC
(1994a, 1994b) used the average contaminant concentration as the exposure point concentration
to calculate central tendency exposure (CTE) to contaminants of concern. CTE uses exposure
assumptions that predict an average or best estimate exposure to an individual and provide the
risk manager with a range of risk estimates for the site. EPA (1992) indicates that only the 95%
UCL should be used as the exposure point concentration, unless that value is greater than the
maximum concentration. In those instances, the maximum concentration should be used should
be used as the exposure point concentration.
Risk-based action levels for lead and arsenic were developed rather than calculating risks for all
areas of recreational land use in the Weston (1995a) RA.
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6.13 RISK CHARACTERIZATION
Results of the tailings RA (WCC 1994a) indicated that risks to recreational visitors and other
visitors from exposure to contaminants in surface tailings did not exceed EPA levels of concern
for carcinogenic and systemic risks. Likewise, results of the waste rock RA (WCC 1994b)
indicated that risks to recreational visitors and other visitors resulting from exposure to waste
rock did not exceed EPA levels of concern for carcinogenic and systemic risks.
Weston (1995a) developed risk-based action levels for lead and arsenic rather than calculating
risks for all areas of recreational land use. The action levels represent risk-based concentrations
protective of human health and may be used to identify soils of potential concern to recreational
visitors.
For lead, action levels ranged from as low as 5,000 mg/kg to 85,000 mg/kg, depending upon
which input parameters were used (Weston 1995a). A lead concentration of 16,000 mg/kg was
selected for comparison to soil concentrations of lead (Weston 1995a). For arsenic, action levels
ranged from 1,400 to 3,200 mg/kg based on carcinogenic and systemic effects, respectively
(Weston 1 995a). An arsenic concentration of 1 ,400 mg/kg was selected for comparison to soil
arsenic concentrations, based on the potential for carcinogenic health effects (Weston 1995a).
Average concentrations of arsenic and lead in exposure areas where recreational use is
considered likely were less than these action levels, indicating that health risk is unlikely to result
from recreational exposure to lead or arsenic in surface soils (Weston 1995a).
6.2 ECOLOGICAL RISKS
Baseline RAs characterizing ecological risks at OU4 consist of:
Weston. 1 995b. Final Baseline Aquatic Ecological Risk Assessment, California Gulch NPL Site
(BARA).
•
Weston. 1997. Ecological Risk Assessment for the Terrestrial Ecosystem, California Gulch
NPL Site, Leadville, Colorado (ERA).
Stoller. 1996. Screening Level Ecological Risk Assessment for Operable Unit No. 4, California
Gulch Superfund Site. Leadville. Colorado (SLERA).
Impacts of mine waste contamination on the aquatic ecosystem at the California Gulch NPL Site
are characterized in the BARA (Weston 1995b). The ERA (Weston 1997) identifies potential
risks to the terrestrial ecosystem from mine wastes within the California Gulch NPL Site. The
SLERA was performed to provide additional, OU4-specific, data to augment the ERA. The
SLERA is equivalent to the preliminary risk calculation step recommended for ecological RAs.
Results of these ecological RAs are summarized below. Conclusions presented in the SLERA
(Stoller 1996) did not constitute the basis for any risk management decisions; decisions presented
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in this ROD are based on information presented in the ERA (Weston 1997) and the BARA
(Weston 1995b).
6.2.1 CONTAMINANT IDENTIFICATION
The BARA (Weston 1995b) identifies the impact of mine waste contamination on the aquatic
ecosystem at the California Gulch Superfund Site. The media of concern evaluated in the BARA
(Weston 1995b) were surface water and sediments. Contaminants evaluated in the BARA
(Weston 1995b) consist of aluminum, antimony, arsenic, barium, cadmium, copper, iron, lead,
manganese, nickel, selenium, and zinc.
Media evaluated in the ERA (Weston 1997) include soil, slag, waste rock, and tailings in uplands
areas, and fluvial tailings and sediment in riparian areas. Only data from the top two inches of
these media were evaluated in the ERA. Adverse impacts on the terrestrial ecosystem from
exposure to contaminants in surface water were also evaluated. Contaminants evaluated in the
ERA (Weston 1997) consist of arsenic, antimony, barium, beryllium, cadmium, chromium,
copper, lead, nickel, manganese, mercury, silver, thallium, and zinc.
The SLERA evaluated terrestrial risks associated with exposure to contaminants in OU4 soils
and surface water. Contaminants evaluated consist of pH, arsenic, cadmium, copper, lead,
magnesium, mercury, selenium, silver, and zinc (Stoller 1996).
Contaminant concentrations in waste rock, tailings, surface water, and sediments are described in
Section 5.2, Nature and Extent of Contamination.
6.2.2 EXPOSURE ASSESSMENT
The BARA (Weston 1995b) evaluated ecological receptors typical of those present or historically
present at the Site, consisting of aquatic plants, benthic macroinvertebrates, and fish (primarily
trout species). The potential exposure pathways for aquatic receptors were ingestion of surface
water, sediments, and dietary items, and direct contact with surface water, sediments, and
modeled concentrations of dissolved contaminants in sediment pore water. Only the direct
contact pathways were evaluated quantitatively.
Receptors evaluated in the ERA (Weston 1997) were representative of those found at OU4:
upland and riparian vegetation communities, birds, and herbivorous and predatory mammals.
Contaminant intakes were estimated for these receptors based on assumptions regarding
exposure, such as food ingestion rates and body weight. Exposure pathways evaluated in the
ERA were as follows: direct exposure to contaminated media, ingestion of ponded water or
surface runoff contaminated by primary source media, incidental ingestion of contaminated
media, and indirect exposure through the food chain.
The SLERA evaluated terrestrial ecosystem exposure pathways. Exposure routes evaluated in
the ERA were evaluated in the SLERA.
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The BARA used the 95% UCL as the exposure point concentration for chronic exposure. If the
95% UCL was greater than the maximum contaminant concentration, the maximum was used as
the chronic exposure point concentration. The maximum contaminant concentration was used to
represent acute exposure (Weston 1995b).
The ERA used the 95% UCL as the exposure point concentration to evaluate risks by OU. If the
maximum contaminant concentration was less than the 95% UCL, the maximum was used as the
exposure point concentration. Risks were also characterized by sampling station in the ERA;
maximum contaminant concentrations were used to calculate risks at individual sampling
stations due to limited data quantities per station.
6.2.3 RISK CHARACTERIZATION
The BARA used EPA AWQC as well as standards developed by the State of Colorado to
evaluate the toxicity of contaminants in surface water to aquatic receptors. Sediment toxicity
values were derived from the toxicological literature. The BARA compared sediment and
surface water toxicity criteria to contaminant exposure point concentrations to determine risk to
aquatic receptors. The resulting value is termed a hazard quotient (HQ). An HQ less than one
indicates there is little potential for adverse effects to occur. An HQ greater than one indicates a
potential for risk but does not necessarily mean that adverse effects will occur. The sum of the
HQs is the hazard index (HI). As stated previously, only direct exposure pathways were
evaluated, therefore, contaminant intake was not calculated for aquatic receptors.
HQs and His specific to OU4 were not presented in the BARA; therefore, this summary does not
provide quantitative risks associated with surface water in OU4. Results of the BARA (Weston
1995b) indicate that mine waste poses potential risk to all aquatic species. The BARA states that
Girabaldi Mine, North Mike, and fluvial tailing, as well as other sources such as high metal
waste rock piles, contribute to the metals entering California Gulch and, ultimately, the Arkansas
River.
The ERA (Weston 1997) reviewed toxicological literature to derive acceptable contaminant
intake values for birds and mammals. Resulting benchmark values, termed Toxicity Benchmark
Values (TBV), were compared to calculated contaminant intakes for upland and riparian
receptors.
To estimate terrestrial risks, the ERA calculated HQs for all contaminants for each receptor by
dividing estimated intake by the TBV. Results of the ERA indicated that the abundance of small
mammals and breeding bird species were generally similar between OU4 and reference areas.
Risk to the mountain bluebird, a songbird, exceeded EPA acceptable levels for exposure to
contaminants in solid surficial material (i.e., tailings, soil). Predatory birds and some mammals
were also at risk at some locations. Cadmium, lead, and zinc frequently contributed to the
elevated risk levels. His specific to terrestrial receptors in OU4 are presented below. Results of
the ERA indicate that surface water ingestion may present a risk to all ecological receptors in
OU4. Action levels were not developed for terrestrial receptors.
Record of Decision
Upper California Gulch OU4
32698 PA32KM)I3\OU4\NEWROD\RODOU4-2.WPD
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Hazard Indices for Receptors Exposed to All Solid Surficial Media in OU4
Blue
Grouse
12
Mountain
Bluebird
296
American
Kestrel
8
Red-tailed
Hawk
4
Bald
Eagle
5
Least
Chipmunk
20
Mule
Deer
1
Red
Fox
6
Source: Weston 1997
The SLERA used a screening level approach to evaluate whether localized disturbances or metal
sources, such as waste rock, have impacted vegetation community quality and wildlife habitat.
Risks were assessed using a HQ approach. The SLERA concluded that vegetation communities
and wildlife habitat in non-waste areas of OU4 show signs of physical impacts from human
activity but do not appear to be adversely impacted by chemical toxicity. Vegetation growth
tests indicated that metal concentrations in soil may inhibit vegetation growth in test species but
that low pH was the most important factor affecting vegetation. Preliminary risk estimates in the
SLERA indicated negligible risk to mammalian and avian predators.
Response actions are necessary at OU4 to control the release of contaminants and acidic water
into the environment. These releases currently present a risk to aquatic and terrestrial ecological
receptors.
Record or Decision
Upper California Gulch OU4
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7.0 DESCRIPTION OF ALTERNATIVES
A wide range of remedial action alternatives for waste rock, fluvial tailings and non-residential
soils were considered in the Screening Feasibility Study (SFS) (EPA, 1993). Some of the
alternatives were eliminated during preliminary screening because they would not effectively
address contamination, could not be implemented, or would have had excessive cost. Remedial
action alternatives for OU4 that were retained after screening alternatives from the SFS were
evaluated in the FFS. These alternatives are designed to meet the RAOs of: 1) controlling wind
and water erosion of waste rock materials, and 2) controlling leaching and migration of metals
from waste rock into surface water and groundwater. In general, the alternatives meet these
RAOs through the use of surface water controls, engineered covers, slope stabilization, and
selected removal of waste rock. All of the alternatives were evaluated using the nine criteria
required by the NCP and six additional performance criteria required by the WAMP as a part of
the CD. This evaluation is described in the next section.
This section provides a description of the remedial action alternatives for the waste rock source
areas in OU4 and the Fluvial Tailing Site 4. In addition, the following paragraphs also
summarize the alternatives for the two removal actions (Garibaldi mine site and Agwalt) as
presented in the EE/CAs (TerraMatrix/SMI, 1995a and 1996b). These removal actions have
been completed.
7.1 GARIBALDI MINE SITE fUCG-1211
The Garibaldi mine site (UCG-121) is located near the headwaters of California Gulch in a small
tributary drainage (Garibaldi Sub-basin). The following four alternatives described below were
analyzed for the Garibaldi mine site waste rock pile. The removal action has been completed.
Garibaldi Mine Site Alternative 1 - No Action
Estimated capital and operating cost: $0'
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated. Baseline conditions at the Garibaldi mine site indicate that the waste rock pile is
susceptible to leaching of metals, acid drainage and erosion of surface material.
Garibaldi Mine Site Alternative 2 (Selected Alternative) - Diversion of Surface Water,
Portal Flow and Groundwater Interception
Estimated capital and operating cost: $208,039
Implementation time: 1 year
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper C*lifon>i« Gulch OU4 p.o 77
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This alternative consists of construction of surface water diversions, shallow alluvial
groundwater interception trenches, and a portal flow collection system. Specifics of this
alternative are described below:
Approximately 1,960 feet of diversion ditches;
• Two groundwater interception trenches;
• Portal flow collection system;
• Energy dissipating channel outlet apron; and,
Approximately 500 feet of access road improvement by regrading.
Garibaldi Mine Site Alternative 3 - Flow Diversion Regrading and Simple Cover
Estimated capital and operating cost: $324,232
Implementation time: 1 year
This alternative would consist of surface water diversion ditches, shallow alluvial groundwater
interception, a portal flow collection system, regrading of the waste rock, and construction of a
simple cover. Details of this alternative are described below:
• Approximately 1,960 feet of diversion ditches;
• Energy dissipating channel outlet aprons;
Two groundwater interceptor trenches;
• Portal flow collection system;
Regrading of the pile to maximum 3H:1V side slopes (approximately 3,100 cy);
• Construction of a 12-inch simple soil cover and revegetation; and,
• Approximately 500 feet of access road improvement by regrading.
This alternative is similar to Alternative 2, but includes regrading the pile and construction of a
simple cover in addition to diversion ditches, shallow groundwater interception and a portal
collection system.
Garibaldi Mine Site Alternative 4 - Removal, Transport and Consolidation
Estimated capital and operating cost: $531,190
Implementation time: 1 year
This alternative consists of removal of waste rock and consolidation at a preselected location.
Specific elements of this alternative include:
• Removal of waste rock (approximately 27,900 cy);
Amendment and revegetation of the site following removal;
Construction of approximately 1,600 feet of haul road; and,
• Improvement of approximately 500 feet of access road as in Alternatives 2 and 3.
Record of Decision
Upper California Gulch OU4
32698 PA32«W)I3\OIM\NEWROD\RODOU4.2.WPD
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7.2 GARIBALDI SUB-BASIN WASTE ROCK rUCG-109Ai
Waste rock pile UCG-109A (McDermith) is located along the lower reach of upper California
Gulch in the Garibaldi Sub-basin. The following three alternatives have been analyzed for waste
rock pile UCG-109A:
Garibaldi Sub-basin Waste Rock Alternative 1 - No Action
Estimated capital and operating cost: $0
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated. Baseline conditions at the waste rock pile UCG-109A indicate that it is susceptible to
leaching of metals, acid drainage and erosion of surface material.
Garibaldi Sub-basin Waste Rock Alternative 2 (Selected Alternative) - Diversion of Surface
Water and Stream Channel Reconstruction
Estimated capital and operating cost: $130,510
Implementation time: 1 year
This alternative would include construction of runon diversion ditches and reconstruction of the
adjacent stream channel to decrease erosion from the waste rock pile. Specific elements of this
alternative include:
• Approximately 850 feet of diversion ditches;
• Improvement of approximately 475 feet of roadway side ditch;
• Installation of one culvert;
• Energy dissipating channel outlet apron; and
• Reconstruction and stabilization of approximately 225 feet of stream channel to
prevent erosion from the waste rock pile.
Garibaldi Sub-basin Waste Rock Alternative 3 - Diversion of Surface Water and Selected
Removal
Estimated capital and operating cost: SI 38,413
Implementation time: 1 year
This alternative would include construction of runon diversion ditches and selected waste rock
removal. Specific elements of this alternative include:
• Approximately 850 feet of diversion ditches;
• Improvement of approximately 475 feet of roadway side ditch;
• Installation of one culvert;
• Energy dissipating channel outlet apron;
Record of Decision
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• Selected removal of approximately 1,000 cubic yards of waste rock material and
consolidation within OU4; and,
• Stabilization of removal area.
73 AGWALT (UCG-104^
The Agwalt waste rock pile and portal are located in the Whites Gulch Sub-basin, a tributary to
Upper California Gulch. The following four alternatives described below were analyzed for
Agwalt waste rock piles. The removal action has been completed.
Agwalt Alternative 1 - No Action
Estimated capital and operating cost: $0'
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
Agwalt Alternative 2 (Selected Alternative) - Diversion Ditches and Portal Diversion
Estimated capital and operating cost: $162,506
Implementation time: 1 year
This alternative would include construction of runon diversion ditches and a portal collection
system to divert portal flow. Specific elements of this alternative include:
• Construction of approximately 1,000 feet of diversion ditches to prevent surface
runon to the pile;
Portal discharge collection system;
Energy dissipating channel outlet aprons; and,
• Improvements to approximately 1,000 feet of access road (i.e., regrading,
widening and blading with heavy equipment).
Agwalt Alternative 3 - Diversions, Regrading and Simple Cover
Estimated capital and operating cost: $259,524
Implementation time: 1 year
This alternative would include construction of runon diversion ditches and a portent collection
system to divert portal flow, as presented for Alternative 2, but would also include regrading of
the pile and placement of a simple cover. Specific elements of this alternative include:
'Incidental administrative costs are incurred under the No Action Alternative
Recent of Decision
Upper California GukhOU4
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• Construction of diversion ditches, a portal collection system, and an outlet apron
as in Alternative 2;
• Pile regraded to 3H: 1V to increase stability and promote non-erosive runoff;
• Construction of a simple cover and establish vegetation to decrease infiltration
from direct precipitation; and,
• Improvements to approximately 1,000 feet of access road (ie., regrading,
widening and blading with heavy equipment).
Agwalt Alternative 4 - Waste Rock Removal
Estimated capital and operating cost: $228,590
Implementation time: 1 year
This alternative would consist of complete waste rock removal with revegetation of the disturbed
area. Specific details of this alternative are described below:
Waste rock would be removed to UCG-71 in Nugget Gulch for remediation under
Alternative 4, Nugget Gulch;
• Stream channel would be reconstructed (approximately 450 feet);
Disturbed areas would be revegetated (-1 acre); and,
• Approximately 1,000 feet of access road would require improvements such as
regrading and blading.
7.4 PRINTER GIRL rUCG-92Ai
The Printer Girl waste rock pile is the second source area retained in Whites Gulch Sub-basin.
As previously described, Whites Gulch is a tributary to upper California Gulch. The following
four alternatives have been analyzed for the Printer Girl waste rock pile.
Printer Girl Alternative 1 - No Action
Estimated capital and operating cost: SO1
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
Printer Girl Alternative 2 - Stream Channel Reconstruction
Estimated capital and operating cost: $54,937
Implementation time: 1 year
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper California Gulch OlM
32698 P:VJ280-OIJ\OU4\NEWROD\RODOU4-2.WPD
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This alternative consists of stream channel reconstruction for the main stem of Whites Gulch
upstream and adjacent to the Printer Girl waste rock pile. Specific elements of this alternative
include:
Re-construction of approximately 420 feet of stream channel;
• Lining of the re-constructed channel with rip-rap; and,
• Minor grading of approximately 700 feet of access road.
Printer Girl Alternative 3 - Stream Channel Reconstruction and Regrading
Estimated capital and operating cost: $55,453
Implementation time: 1 year
Stream channel reconstruction and regrading are the main features of this alternative at the
Printer Girl mine site. Specific elements of this alternative include:
• Regrading of all waste rock adjacent to the stream channel;
• Re-construction of approximately 420 feet of stream channel;
• Approximately 700 feet of access road would require minor improvement.
Printer Girl Alternative 4 (Selected Alternative) - Waste Rock Removal
Estimated capital and operating cost: $99,288
Implementation time: 1 year
For this alternative the waste rock located along the channel of Whites Gulch would be removed,
the disturbed area above the access road would be regraded and channels would be constructed to
minimize impacts of runon and runoff. Specific elements of this alternative include:
Waste rock from pile UCG-92A would be removed to the UCG-71 for
remediation under Alternative 4, Nugget Gulch;
Remaining material would be regraded to increase stability and promote non-
erosive runoff;
• Approximately 300 feet of lined diversion ditch would be constructed;
• Approximately 250 feet of unlined diversion ditch would be constructed and
armored with riprap as necessary;
• Disturbed areas would be revegetated (-1.1 acres); and,
• Approximately 700 feet of access road would require minor blading.
7.5 NUGGET GULCH OJCG-71. -74. -76. -77. -79. -80. -85^
The Nugget Gulch source area is characterized by the waste rock piles retained from the
screening process within the Nugget Gulch Sub-basin. These waste rock piles include; UCG-71
(Colorado No. 2), UCG-74 (Rubie), UCG-76, UCG-77, UCG-79 (North Moyer), UCG-80
(Moyer) and UCG-85 (North Mike). The following alternatives have been analyzed for the
Nugget Gulch Sub-basin waste rock piles:
Record of Deciwon
Upper California Gulch OlM
32698 P:\32KW13\OU4\NEWROD\RODOU4-2.WPD
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Nugget Gulch Alternative 1 - No Action
Estimated capital and operating cost: SO1
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
Nugget Gulch Alternative 2 - Diversion Ditches
Estimated capital and operating cost: $299,026
Implementation time: 1 year
This alternative would include construction of surface water diversion ditches and a groundwater
interception trench. Details of this alternative are described below:
• Approximately 5,700 linear feet of diversion ditches would be constructed;
• Groundwater interception trench would be installed upgradient of North Mike
waste rock;
• Three culverts would be installed, and
• Selective revegetation would be performed as required.
Nugget Gulch Alternative 3 - Diversion Ditches and Waste Rock Regrading
Estimated capital and operating cost: $369,702
Implementation time: 1 year
This alternative would include diversion ditches and regrading waste rock piles (UCG-71, -74, -
76, -77 and -85) to enhance stability. Specific details of this alternative are described below:
Diversion ditches, groundwater interception trench and culverts would be
constructed, the same as Alternative 2;
Waste rock piles UCG-71, -74, -76, -77, and -85 (approximately 14,200 cy) would
be regraded; and,
• Terraces would be added and disturbed areas revegetated.
This alternative is similar to Alternative 2, but includes regrading of selected piles in addition to
the diversion ditches.
Nugget Gulch Alternative 4 (Selected Alternative) - Diversion Ditches, Consolidation and
Cover
Estimated capital and operating cost: $800,012
Implementation time: 1 year
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper California Gulch OU4
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This alternative incorporates diversion ditches, consolidation of waste rock at UCG-71,
placement of a simple cover to reduce infiltration, and revegetation of disturbed areas. Details of
this alternative are described below:
• Diversion ditches and culverts as described for Alternative 3;
Haul waste rock piles UCG-74, -76, -77, and -85 to UCG-71 for consolidation
(19,250 cy);
• Regrading and placement of a simple cover over the consolidated material at
UCG-71 (the surface will be revegetated or covered with rock);
Amendment and revegetation of disturbed areas; and,
• Addition of terraces to waste rock removal/disturbed areas.
7.6 AY-MINNIE fUCG-8n
The AY-Minnie waste rock (UCG-81) is located north of County Road 2, along both sides of
lower Nugget Gulch. The following four alternatives have been analyzed for the AY-Minnie
waste rock pile:
AY-Minnie Alternative 1 - No Action
Estimated capital and operating cost: SO1
Implementation time: Immediately
No remediation would take place under this alternative. This is the "no" action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
AY-Minnie Alternative 2 - Diversion Ditches
Estimated capital and operating cost: $169,081
Implementation time: 1 year
This alternative would consist of constructing diversion ditches. Details of this alternative are
described below:
Construction of 2,000 feet of unlined channel; and,
• Installation of one culvert.
AY-Minnie Alternative 3 - Diversion Ditches and Regrade
Estimated capital and operating cost: $ 184,131
Implementation time: 1 year
This alternative includes diversion ditches, removal of cribbing, and limited regrading of waste
rock. Specific elements of this alternative include:
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper California Gulch OU4
32698 P:\3280-OIJ\OLU\NEWROD\RODOLH-2.WPD
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Diversion ditches and culvert as in Alternative 2;
• Removing cribbing along County Road 2; and
Regrading waste rock.
AY-Minnie Alternative 4 (Selected Alternative) - Diversion Ditches and Road Relocation
Estimated capital and operating cost: $240,820
Implementation time: 2 years
This alternative consists of realigning County Road 2, constructing diversion ditches, and adding
a sediment pond to capture sediment from the AY-Minnie during runoff events. Specific
elements of this alternative include:
• Diversion ditches and culvert as in Alternative 2;
• Construction of a sediment retention pond; and,
• Realignment of County Road 2.
7.7 IRON HILL (UCG-12)
The Iron Hill drainage is located southeast of, and is the closest OU4 sub-basin to, the populated
areas of Leadville. Waste rock pile UCG-12 (Mab) has been identified as a potential source of
contamination within the Iron Hill Sub-basin. The following alternatives have been evaluated for
the Iron Hill Sub-basin waste rock pile:
Iron Hill Alternative 1 - No Action
Estimated capital and operating cost: $0'
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
Iron Hill Alternative 2 - Diversion Ditches
Estimated capital and operating cost: $117,189
Implementation time: 1 year
This alternative would consist of constructing diversion ditches around the waste rock pile to
reduce mnon of surface water. Specific elements of this alternative include:
Construction of 500 feet of lined diversion channel at UCG-12,
Amendment application and revegetation of disturbed area below UCG-12 (~3.0
ac).
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper Califomii Gulch DIM
32698
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Iron Hill Alternative 3 (Selected Alternative) - Regrading and Simple Cover
Estimated capital and operating cost: $159,776
Implementation time: 1 year
This alternative consists of regrading the waste rock pile (UCG-12) and the placement of a
simple cover over the pile to eliminate ponding of surface water on the waste rock and reduce
infiltration of surface water through the waste rock pile. Specific elements of this alternative
include:
• Minor grading to improve surface runoff (approximately 1,000 cy at UCG-12);
Placement of a simple cover on UCG-12 (~ 1,700 cy of material); and,
• Revegetation of surrounding areas (~ 3.0 ac) and revegetation of the cover surface
or placement of rock on the cover surface.
Iron Hill Alternative 4 - Waste Rock Consolidation
Estimated capital and operating cost: $227,759
Implementation time: 1 year
This alternative consists of consolidating the waste rock pile (UCG-12) with waste rock pile
UCG-71. The area disturbed by waste rock removal will be revegetated. Specific elements of
this alternative include:
• Removal and haulage of approximately 5,500 cy of waste rock from UCG-12 to
UCG-71; and,
• Amendment and revegetation of disturbed area at UCG-12.
7.8 CALIFORNIA GULCH WASTE ROCK OJCG-33A. -65. -75. -82A. -93. -95 AND -
28}
The remaining waste rock piles in Upper California Gulch requiring remediation are located in
the South Area Sub-basin. These waste rock piles include; UCG-33A, UCG-65, UCG-75
(Minnie Pump Shaft), UCG-82A, UCG-93, UCG-95 and UCG-98 (Lower Printer Boy). The
following alternatives have been analyzed for the South Area Sub-basin (California Gulch) waste
rock piles:
California Gulch Waste Rock Alternative 1 - No Action
Estimated capital and operating cost: $0'
Implementation time: Immediate
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper California Gulch OU4
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No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
California Gulch Waste Rock Alternative 2 (Selected Alternative) - Stream Channel
Reconstruction
Estimate capital and operating cost: $548,341
Implementation time: 1 year
This alternative would prevent contact of waste rock with Upper California Gulch surface water
flows. The reconstructed stream channel would be sized to provide stability for the 500-year
flood event. Specific elements of this alternative include:
• Reconstruction and stabilization of approximately 2,150 feet of stream channel to
prevent erosion from the waste rock piles.
California Gulch Waste Rock Alternative 3 - Selected Regrading
Estimated capital and operating cost: $67,085
Implementation time: 1 year
This alternative consists of regrading selected waste rock piles to enhance slope stability and
reduce surface erosion. Specific element of this alternative include:
• Grading to improve surface runoff and erosional stability (-7,500 cy of material).
California Gulch Waste Rock Alternative 4 - Selected Waste Rock Removal
Estimated capital and operating cost: $425,731
Implementation time: 1 year
This alternative consists of the removal of selected waste rock piles and consolidation at a
selected location. The area disturbed by waste rock removal will be revegetated. Specific
elements of this alternative include:
• Removal and haulage of selected waste rock (~15,000 cy); and,
• Amendment and revegetation of disturbed area (3.7 acres).
Record of Decision
Upper California Gulch OU4
32698 P:\32SO-OIJ\OU4\NEWROD\RODOU4-2.WPD
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7.9 FLUVIAL TAILING fSITE 41
The Fluvial Tailing Site 4 and the South Area Sub-basin drains the hillslope which separates
OU4 from Iowa Gulch. The following four alternatives have been analyzed for the Fluvial
Tailing Site 4.
Fluvial Tailing Site 4 Alternative 1 - No Action
Estimated capital and operating cost: $0'
Implementation time: Immediate
No remediation would take place under this alternative. This is the "no action" alternative
required under CERCLA and is used as a baseline against which the other alternatives are
evaluated.
Fluvial Tailing Site 4 Alternative 2 - Channel Reconstruction with Revegetation
Estimated capital and operating cost: $2,393,933
Implementation time: 1 year
This alternative includes reconstruction of the stream channel and adjacent floodplain to provide
stability under a 500-year flood event and revegetation of disturbed areas to increase erosional
stability. Specific elements of this alternative include the following:
• Channelization of approximately 8,600 feet of upper California Gulch;
• Regrading and blending of channelization spoil material into adjacent areas;
• Regrading side slopes along the channel;
• Minor surface regrading to enhance positive runoff; and,
• Amending and revegetating approximately 16 acres (selective revegetation).
Fluvial Tailing Site 4 Alternative 3 - Channel Reconstruction with Sediment Dams and
Wetlands
Estimated capital and operating cost: $2,226,929
Implementation time: 1 year
This alternative consists of reconstruction of the stream channel and adjacent floodplain to
provide stability under a 500-year flood event. Sediment check dams and wetlands will be
constructed to control sediment discharge. Specific elements of this alternative include:
• Channelization of approximately 8,600 feet of upper California Gulch;
• Regrading and blending of channelization spoil material into adjacent areas;
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper California Gulch OU4 r-c .„
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• Regrading side slopes along channel to 2H: 1V (13,500 cy);
• Minor surface regrading to enhance positive runoff;
• Construction of approximately eight sediment control dams; and,
• Construction of approximately 1.5 acres of wetlands.
Fluvial Tailing Site 4 Alternative 4 - Channel Reconstruction, Revegetation, Sediment
Dams and Wetlands
Estimate capital and operating cost: $2,544,293
Implementation time: 1 year
This alternative is similar to Alternative 3 plus revegetation of disturbed areas is added to further
reduce sediment generation and discharge. Specific elements of this alternative include:
• Channelization of approximately 8,600 feet of upper California Gulch;
• Regrading and blending of channelization spoil material into adjacent areas;
• Regrading of side slopes along channel to 2H: 1V (13,500 cy);
• Minor surface regrading to enhance positive runoff;
• Amending and revegetating approximately 16 acres (selective revegetation);
• Construction of approximately eight sediment dams; and,
• Construction of approximately 1.5 acres of wetlands.
Fluvial Tailing Site 4 Alternative 5 (Selected Alternative) - Channel Reconstruction,
Revegetation, Sediment Dams, Wetlands and Selected Surface Material Removal
Estimate capital and operating cost: $2,653,493
Implementation time: 1 year
This alternative combines selected surface material removal with Fluvial Tailing Site 4
Alternative 4. Specific element of this alternative include:
• Channelization of approximately 8,600 feet of upper California Gulch;
• Regrading and blending of channelization spoil material into adjacent areas;
• Minor surface regrading to enhance positive runoff;
• Amending and revegetating approximately 16 acres (selective revegetation);
• Construction of approximately eight sediment dams;
• Selected removal of one foot of surface material (depth to be determined during
implementation) from the floodplain of upper California Gulch from immediately
upstream of the confluence with Nugget Gulch to immediately upstream of the
Minnie Pump Shaft (waste rock pile UCG-75) and replacement with one foot of
imported borrow material (removal of one foot of material over the entire area has
been assumed for costing purposes);
• Material removed from Fluvial Site 4 will be consolidated within OU4;
Record of Decision
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• Construction of one sediment retaining structure along the toe of waste rock pile
UCG-82A; and,
• Construction of approximately 2.5 acres of wetlands.
7.10 NON-RESIDENTIAL SOILS
Due to the lack of ecological risk posed by non-residential soils in OU4, the only alternative
retained is the No Action alternative.
Non-Residential Soils Alternative 1 - No Action
Estimated capital and operating cost: SO1
Implementation time: Immediate
'Incidental administrative costs are incurred under the No Action Alternative
Record of Decision
Upper California Gulch OU4 nc
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8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Section 300.43 0(e)(9) of the NCP requires that the EPA evaluates and compares the remedial
cleanup alternatives based on the nine criteria listed below. The first two criteria, (1) overall
protection of human health and the environment and (2) compliance with applicable or relevant
and appropriate requirements (ARARs) in Appendix A, are threshold criteria that must be met
for the Selected Remedy. The Selected Remedy must then represent the best balance of the
remaining primary balancing and modifying criteria. In addition the cleanup alternatives were
evaluated using six performance criteria specified in the WAMP (USDC, 1994) to assist in
evaluating the effectiveness of each alternative.
8.1 NCP EVALUATION AND COMPARISON CRITERIA
8.1.1 THRESHOLD CRITERIA
1. Overall protection of human health and the environment addresses whether or not a
remedy provides adequate protection and describes how potential risks posed through
each pathway are eliminated, reduced, or controlled through treatment, engineering
controls, or Institutional Controls.
2. Compliance with ARARs addresses whether or not a remedy will comply with identified
federal and state environmental and siting laws and regulations.
8.1.2 PRIMARY BALANCING CRITERIA
3. Lone-term effectiveness and permanence refers to the ability of a remedy to maintain
reliable protection of human health and the environment over time.
4. Reduction of toxicity. mobility and volume through treatment refers to the degree that the
remedy reduces toxicity, mobility, and volume of the contamination.
5. Short-term effectiveness addresses the period of time needed to complete the remedy and
any adverse impact on human health and the environment that may be posed during the
construction and implementation period until cleanup goals are achieved.
6. Implementability refers to the technical and administrative feasibilities of a remedy,
including the availability of materials and services needed to carry out a particular option.
7. Cost evaluates the estimates capital costs, operation and maintenance (O&M) costs, and
present worth costs of each alternative.
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8.13 MODIFYING CRITERIA
8. State acceptance indicates whether the State (CDPHE), based on its review of the
information, concurs with, opposes, or has no comment on the preferred alternative.
9. Community acceptance is based on whether community concerns are addressed by the
Selected Remedy and whether or not the community has a preference for a remedy.
8.2 WAMP PERFORMANCE CRITERIA
Additional site-specific criteria beyond the required NCP criteria have been developed for
evaluating remedial alternatives for OU4. These criteria are described in the WAMP attached as
Appendix D to the Consent Decree for the California Gulch Site. The six WAMP (USDC, 1994)
criteria described below have assisted in the evaluation of the effectiveness of each proposed
alternative:
1. Surface Erosion Stability: Remedial alternatives for source material will ensure surface
erosion stability through the development of surface configurations and implementation
of erosion protection measures. The remedial design will meet the following criteria:
a. Erosional releases of waste material are predicted by use of all or some of the
following procedures: the Revised Universal Soils Loss Equation (RUSLE), wind
erosion soil loss equation (Woodruff and Siddoway, 1965), and the procedures set
forth in the U.S. Nuclear Regulatory Commission's Staff Technical Position,
Design of Erosion Protection Covers for Stabilization of Uranium Mill Tailings
Sites (NRC, 1990) for site-specific storm flow conditions set forth in l.b below.
b. Remediated surfaces located within the 500-year floodplain will be stable under
500-year, 24-hour, and 2-hour storm events. Remediated surfaces located outside
the 500-year floodplain will be stable under 100-year, 24-hour, and 2-hour storm
events. On source embankments or where the slope of the reconstructed source is
steeper than 5:1 (Horizontal:Vertical), surface flow will be concentrated by a
factor of 3 for purposes of evaluating erosion stabi lity.
2. Slope Stability: Source remediation alternatives will ensure geotechnical stability
through the development of embankments or slope contours. The remedial design will
meet the following criteria:
a. Impounding embankments will be designed with a Factor of Safety (Safety
Factor) of 1.5 for static conditions and 1.0 for pseudo-static conditions.
b. Recontoured slopes will be designed with a Safety Factor of 1.5 for static
conditions and 1.0 for pseudo-static conditions.
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c. Analysis of geotechnical stability will be performed using an acceptable computer
model. Material and geometry input parameters will be obtained from available
data.
3. Flow Capacity and Stability: Remedial alternatives utilizing retaining structures,
diversion ditches, or reconstructed stream channels will ensure sufficient capacity and
erosional stability of those structures. The remedial design will meet the following
criteria:
a. Capacity: Diversion ditches will be sized to convey the 100-year, 24-hour, and 2-
hour storm events. Reconstructed stream channels will be sized to convey flow
equal to or greater than the flow capacity immediately upstream of the
reconstruction.
b. Stability: Erosional release of waste material from ditches, stream channels, or
retaining structures will be determined by either or both of the following models:
U.S. Army Corps of Engineers Hydrologic Engineering Center HEC-1 (COE,
1991) and HEC-2 (COE, 1990) models.
1) Diversion Ditches and Reconstructed Stream Channels: Remedial
surfaces located within the California Gulch 500-year floodplain will be
designed to be stable under flows resulting from 500-year, 24-hour, and 2-
hour storm events. Remedial construction outside the 500-year floodplain
will be designed to withstand flows resulting from the 100-year, 24-hour,
and 2-hour storm events. Reconstructed stream channels will be
configured to the extent practicable to replicate naturally occurring
channel patterns.
2) Retaining Structures: Structures such as gabions, earth dikes, or riprap
will be designed to be stable under the conditions stated above under item
S.b.l for the diversion ditch or stream channel with which the structure is
associated. If riprap is to be placed in stream channels or ditches, the
riprap will be sized utilizing one of the following methods:
U.S. Army Corps of Engineers (COE, 1991);
Safety Factor Method (Stevens and Simons, 1971);
Stephenson Method (Stephenson, 1979);
Abt/CSU Method (Abt, et. al., 1988).
Selection of one of these methods will be based on the site-specific flow
and slope conditions encountered.
4. Surface and Groundwater Loading Reduction: Remedial alternatives will ensure
reduction of mass loading of COCs (including TSS and sulfate), as defined in the Draft
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Final Terrestrial Risk Assessment (see WAMP [USDC, 1994]), and change in pH,
resulting from runon, runoff, and infiltration from source areas. The FFS will incorporate
the following:
a. For each source of contamination evaluated in the FFS, the present mass loading
of COCs (including TSS and sulfate) will be calculated for both surface and
groundwater using scientifically accepted methods. Present pH measurements
will be used.
b. For each source of contamination evaluated in the FFS, the net loading reduction
of COCs (including TSS and sulfate) and change in pH resulting from
implementation of each remedial alternative shall be calculated for surface and
groundwater using scientifically accepted methods.
5. Terrestrial Ecosystem Exposure: Evaluation of remedial action alternatives with respect
to reduction of risk to the terrestrial ecosystems within each OU should be based on area-
wide estimates of risk to receptor populations. Exposure estimates for assessing this risk
should consider factors that affect the frequency and duration of contact with
contaminated media, such as: (1) the concentrations and area! extent of contamination,
and (2) the effect of home range on the amount of time a given species will spend in
contact with contaminated media. For each source of contamination evaluated in the
FFS, the reduction of the potential exposure predicted to result from the implementation
of each remedial action alternative will be compared to the present potential exposure
predicted by the terrestrial ecosystem risk assessment, as follows:
a. For each source of contamination evaluated in the FFS, the present risk due to
exposure as defined in the terrestrial ecosystem risk assessment will be estimated
for soil, each source of contamination, and ponded surface water associated with
each source of contamination.
b. For each source of contamination evaluated in the FFS, reduction of exposure and
ecological risk resulting from the implementation of each remedial alternative will
be estimated for soil and the media types above. The potential exposure predicted
to result from implementation of each remedial alternative will be compared to the
present potential baseline exposure predicted by the terrestrial ecosystem risk
assessment.
6. Non-residential Soils: Non-residential soils will be addressed in the FFS. These non-
residential soils are in areas zone agricultural/forest, highway/business, and
industrial/mining. The non-residential areas within the OU will be evaluated in the FFS
consistent with current and likely future land use.
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83 EVALUATING THE ALTERNATIVES WITH THE NCP CRITERIA
A comparative analysis of the Garibaldi and AgwaJt mine site removal action alternatives were
performed in the EE/CAs (TerraMatrix/SMI, 1995a and 1996a) and subsequently summarized in
their respective Action Memorandum (EPA, 1995a and 1996a). The EE/CAs found that the
selected alternatives for the Garibaldi Mine site (Alternative 2 - Diversion of Surface Water,
Portal Flow and Groundwater Interception) and the Agwalt Mine site (Alternative 2 - Diversion
Ditches and Portal Diversion) would both achieve RAOs and comply with ARARs.
The following is a brief summary of the evaluation and comparison of the alternatives for the
waste rock (Garibaldi Sub-basin, Printer Girl, Nugget Gulch, AY-Minnie, Iron Hill and
California Gulch) and the Fluvial Tailing Site 4 located within OU4. Additional details
evaluating the alternatives are presented in the FFS. This section evaluates each alternative with
the nine NCP criteria. Tables 10 through 16 provide a comparison of the remedial alternatives
and the nine NCP criteria for the waste rock and fluvial tailing. Information for this section was
obtained from the FFS for Upper California Gulch (OU4) (TerraMatrix/SMI, 1998).
8.3.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The criterion is based on the level of protection of human health and the environment afforded by
each alternative.
Garibaldi Sub-basin Waste Rock (UCG-109a)
Because Alternative 1 (No Action) is not protective of human health and the environment, it is
not considered further in this analysis as an option for this site. Alternatives 2 and 3 would
reduce the erosion of waste rock soils through the construction of diversion ditches. Alternative
3 potentially adds further protection to human health at the selected source removal locations.
Printer Girl Waste Rock
Because Alternative 1 (No Action) is not protective of human health and the environment, it is
not considered further in this analysis as an option for this site. Alternatives 2 and 3 would
reduce erosion and releases to surface water and groundwater through channel reconstruction and
regrading. However, neither alternative would reduce the potential for leaching contaminants to
surface and groundwater due to meteoric water that falls directly on the waste rock. By
removing the source Alternative 4 would provide the best protection of human health and the
environment and meet the RAO's defined for waste rock.
Nugget Gulch Waste Rock
Because Alternative 1 (No Action) is not protective of human health and the environment, it is
not considered further in this analysis as an option for this site. Alternatives 2 and 3 would
reduce the erosion of waste rock soils through regrading and the construction of diversion ditches
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by diverting runon away from the waste rock. Erosion and leaching due to the precipitation that
falls directly onto the waste rock would not be addressed. Alternative 4 would provide
protection to human health and the environment by meeting RAO's for waste rock. Alternative 4
would offer the greatest reduction in erosion, transport and airborne emissions of waste rock
through the placement of a simple cover.
AY-Minnie Waste Rock
Because Alternative 1 (No Action) is not protective of human health and the environment, it is
not considered further in this analysis as an option for this site. Alternatives 2, 3 and 4 would
reduce the erosion of waste rock soils through the construction of diversion ditches and regrading
by diverting runon away from the waste rock. Erosion and leaching due to the precipitation that
falls directly onto the waste rock would not be addressed. Alternative 4 adds further protection
by realigning County Road 2 to allow timber cribbing to fail naturally, while not providing an
adverse effect to the historic site.
Iron Hill Waste Rock
Because Alternative 1 (No Action) is not protective of human health and the environment, it is
not considered further in this analysis as an option for this site. Alternative 2 would reduce the
erosion of waste rock soils through the construction of diversion ditches by diverting runon away
from the waste rock. Erosion and leaching due to the infiltration of precipitation that falls
directly onto the waste piles would not be addressed. Alternatives 3 and 4 would provide the
best protection of human health and the environment by meeting the RAO's for waste rock
through the placement of a simple cover.
California Gulch Waste Rock
Because Alternative 1 (No Action) is not protective of human health and the environment it is
not considered further in this analysis as an option for this site. Alternatives 2 and 3 would
reduce erosion and infiltration to surface and groundwater through channel reconstruction and
selected regrading. However neither alternative would reduce the leaching of contaminants due
to the precipitation that falls directly on the waste rock. Alternative 4 would provide protection
of human health and the environment at the selected source removal locations by meeting the
RAO's defined for waste rock.
Fluvial Tailing Site 4
Because Alternative 1 (No Action is not protective of human health and the environment, it is not
considered further in this analysis as an option for this site. Alternatives 2, 3,4 and 5 would
reduce erosion and releases to surface water and groundwater associated with stream flow
through channel reconstruction. Alternatives 3,4 and 5 would further reduce the transport of soil
and meet the RAOs defined for fluvial tailing by the construction of sedimentation dams and
wetlands.
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83.2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS (ARARs)
This criterion is based on compliance with the ARARs presented in Appendix A.
Garibaldi Sub-basin Waste Rock
Alternatives 2 and 3 would comply with all ARARs.
Printer Girl Waste Rock
Alternatives 2 through 4 would comply with all ARARs.
Nugget GuJch Waste Rock
Alternatives 2 through 4 would comply with all ARARs.
AY-Minnie Waste Rock
Alternatives 2 through 4 would comply with all ARARs.
Iron Hill Waste Rock
Alternatives 2 through 4 would comply with all ARARs.
California Gulch Waste rock
Alternatives 2 through 4 would comply with all ARARs.
Fluvial Tailing Site 4
Alternatives 2 through 5 would comply with all ARARs.
8.3.3 LONG-TERM EFFECTIVENESS AND PERMANENCE
Garibaldi Sub-basin Waste Rock
For Alternatives 2 and 3 the construction of diversion ditches would reduce leaching and erosion
with stream flow. Effectiveness and permanence would be achieved through the use of design
and construction methods that have proved to be effective at other sites. Alternative 3 would
potentially provide the highest level of permanence and long term effectiveness through selected
waste rock removal.
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Printer Girl Waste Rock
For Alternatives 2 and 3 the effectiveness and permanence of channel reconstruction would be
achieved through use of design and construction methods that have proved effective at other
sites. However, through removal of the source (Alternative 4), both long-term-effectiveness and
permanence would be assured.
Nugget Gulch Waste Rock
For Alternatives 2 and 3 the construction of diversion ditches and waste rock regrading would
reduce leaching and erosion with stream flow. Effectiveness and permanence would be achieved
through the use of design and construction methods that have proved to be effective at other
sites. Alternative 4 would provide the highest level of permanence and long term effectiveness
through construction of a cover.
AY-Minnie Waste Rock
For Alternatives 2, 3 and 4 the construction of diversion ditches would reduce erosion and
leaching with stream flow. Effectiveness and permanence would be achieved through use of
proven design and construction methods by designing the alternative to meet WAMP criteria for
flow capacity and stability. Alternative 4 would provide the highest level of permanence and
long term effectiveness through the realignment of County Road 2, allowing the timber cribbing
to fail naturally, while not adversely affecting the historic site.
Iron Hill Waste Rock
For Alternative 2 the construction of diversion ditches would reduce erosion, leaching and
transport of contaminants associated with stream flow. Alternatives 3 and 4 would provide the
highest level of permanence and long term effectiveness through the construction of a cover.
California Gulch Waste Rock
For Alternative 2 the effectiveness and permanence of channel reconstruction would be achieved
through use of design and construction methods that have proved effective at other sites.
Selected regrading of waste piles (Alternative 3) would enhance slope stability and reduce
erosion. Through removal of the source (Alternative 4) both long term effectiveness and
permanence would be assured.
Fluvial Tailing Site 4
Channelization of upper California Gulch (Alternatives 2, 3,4 and 5) would reduce erosion,
infiltration, leaching and transport of contaminants. Effectiveness and permanence would be
achieved for the stream channel through the use of design and construction methods that have
proven to be effective at other sites. Alternatives 3 and 4 provide additional long term
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stabilization through construction and maintenance of sediment dams and by regrading tailing
surfaces to promote positive drainage. Alternative 5 would provide a slightly higher level of
permanence and long term effectiveness through revegetation and selected surface material
removal.
8.3.4 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH
TREATMENT
This criterion is based on the treatment process used; the amount of contamination destroyed or
treated; the reduction of toxicity, mobility, and volume; the irreversible nature of the treatment;
the type and quantity of residuals remaining; and the statutory preference for treatment.
Garibaldi Sub-basin Waste Rock
The mobility of contaminants would be decreased by a reduction of runon to the piles through
diversion ditches (Alternatives 2 and 3). A reduction in toxicity, mobility, and volume at this
site would be achieved by implementation of Alternative 3 (selected removal of waste rock),
however treatment is not applicable for this alternative.
Printer Girl Waste Rock
For Alternatives 2 and 3 the mobility of waste rock soils (contaminants) would be reduced by the
prevention of erosion from the pile through the construction of diversion ditches. Toxicity and
volume of waste rock would be unaffected by these alternatives. Treatment is not applicable for
these alternatives. A reduction in toxicity, mobility, and volume at this site would be achieved
through implementation of Alternative 4 (Waste Rock Removal), however treatment is not
applicable for this alternative.
Nugget Gulch Waste Rock
The mobility of contaminants would be decreased by a reduction of runon to the piles through
diversion ditches and regrading (Alternatives 2 and 3). Toxicity and volume of waste rock would
be unaffected by these alternatives, and treatment is not included. An additional reduction in
toxicity and mobility at this site would be achieved through waste pile consolidation and the
construction of a simple cover (Alternative 4), however treatment is not applicable for this
alternative.
AY-Minnie Waste Rock
For Alternatives 2, 3 and 4 the mobility of waste rock soils would be reduced by prevention of
erosion from the pile through the construction of diversion ditches and regrading. Toxicity and
volume of waste rock would be unaffected by these alternatives and treatment is not included.
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Iron Hill Waste Rock
The construction of diversion ditches (Alternative 2) would reduce the mobility of waste rock
soils by prevention of runon to the piles. Toxicity and volume of waste rock would be unaffected
by this alternative, and treatment is not included. An additional reduction in mobility at this site
would be achieved through the construction of a simple cover (Alternatives 3 and 4). Through
waste pile consolidation Alternative 4 would further reduce leaching and loading from the site,
however treatment is not applicable for either of these alternatives.
California Gulch Waste Rock
For Alternatives 2 and 3 the mobility of waste rock soils would be reduced by the prevention of
erosion from the piles through channel reconstruction and selected grading. Toxicity and volume
would be unaffected by these alternatives. These alternatives would not comply with the
statutory preference for treatment. A reduction in toxicity, mobility, and volume at this site
would be achieved through selected waste rock removal (Alternative 4) however, treatment is not
applicable for this alternative.
Fluvial Tailing Site 4
For alternatives 2, 3 and 4 the mobility of soil would greatly be reduced by channelization, but
the toxicity and volume of material would not be affected by these alternatives. Through the
construction of sediment retention dams (Alternatives 3,4 and 5) and re vegetation (Alternatives
4 and 5) mobility of soil would be further reduced. A reduction in toxicity, mobility, and volume
at this site would be achieved by selected surface material removal (Alternative 5), however,
treatment is not applicable for any of these alternatives.
8.3.5 SHORT-TERM EFFECTIVENESS
This criterion is based on the degree of community and worker protection offered, the potential
environmental impacts of the remediation, and the time until the remedial action is completed.
Garibaldi Sub-basin Waste Rock
Potential risks to the community include dust emissions and increased road traffic. Risks would
be minimized through the implementation of dust abatement measures and engineering controls
during construction.
Printer Girl Waste Rock
Risk to the community during the implementation of Alternatives 2, 3 and 4 may result from
construction related dust emissions and increased road traffic. Short-term risks could be
effectively managed using conventional construction techniques for dust abatement (site
watering) and traffic control.
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Nugget Gulch Waste Rock
Additional risk to the community during implementation of Alternatives 2 through 4 may result
from dust emissions and increased road traffic. Short-term risk factors could be effectively
managed with standard engineering controls during construction. Dust abatement (site watering)
is a commonly practiced construction method.
AY-Minnie Waste Rock
Risk to the community during implementation of Alternatives 2 through 4 may result from
construction related dust emissions and increased road traffic. Realignment of County Road 2
(Alternative 4) would slightly increase dust emissions and heavy equipment traffic. Engineering
controls for dust abatement (construction site watering and dust control practices) would
effectively reduce these short-term risks.
Iron Hill Waste Rock
For Alternatives 2, 3 and 4 engineering controls would be used to reduce the short-term risk to
the community due to dust emissions and exposure of workers to contaminants. Dust generation
would be mitigated using standard construction dust control practices (site watering).
California Gulch Waste Rock
Risk to the community during the implementation of Alternatives 2 through 4 may result from
construction related dust emissions and increased road traffic. Risk to workers during
implementation of these alternatives may result from dust inhalation, contact with contaminated
materials and other industrial hazards. Contact with tailings by trained remediation workers
would be minimal, because appropriate safety measures would be utilized. Short-term risks due
to dust emissions could be effectively managed using engineering controls for dust abatement.
Potential impacts to the environment as a result of implementation of Alternatives 3 and 4
include construction related discharge of sediment to downstream surface water resources. This
impact would be minimized, however, through the use of sediment control measures.
Fluvial Tailing Site 4
Additional risk to the community during implementation of Alternatives 2 through 5 may result
from dust emissions and increased road traffic. The topography surrounding the remediation
area and the prevailing wind directions in the area (predominantly from the northwest) are
conducive to natural abatement of short-term risk to the community from these alternatives.
Furthermore, short-term risk factors could be effectively managed with standard engineering
controls during construction. Dust abatement is a commonly practiced construction method.
Additional traffic would be light and limited to private roads in the immediate vicinity of Fluvial
Tailing Site 4.
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83.6 IMPLEMENTABILITY
This criterion is based on the ability to perform construction and implement administrative
actions.
Garibaldi Sub-basin WflSt? Rock
The construction technologies used in Alternatives 2 and 3 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
Printer Girl Waste Rock
The construction technologies used in Alternatives 2 through 4 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
Nugget Gulch Waste Rock
The construction technologies used in Alternatives 2 through 4 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
AY-Minnie Waste Rock
The construction technologies used in Alternatives 2 through 4 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
Iron Hill Waste Rock
The construction technologies used in Alternatives 2 through 4 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
California Gulch Waste Rock
The construction technologies used in Alternatives 2 through 4 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
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Fluvial Tailing Site 4
The construction technologies used in Alternatives 2 through 5 are commonly used and widely
accepted. Materials and personnel would be readily available for this type of work. Unusual
administrative issues are not anticipated.
8.3.7 COST
This criterion evaluates the estimated capital, O&M and present worth costs of each alternative.
Garibaldi Sub-basin Waste Rock
Present worth costs range from $130,510 (Alternative 2) to $138,413 (Alternative 3). The
present worth of post-removal site control costs for a 30-year period were calculated using a 7
percent discount rate.
Alternative 2: Surface Water Diversion. Stream Channel Reconstruction
The estimated cost for this alternative would be $130,510. Estimated cost details are
summarized in Table 17.
Alternative 3: Surface Water Diversion. Selected Removal
The estimated cost for this alternative would be $138,413. Estimated cost details are
summarized in Table 18.
Printer Girl Waste Rock
Present worth costs range from $54,900 (Alternative 2) to $99,300 (Alternative 4). The present
worth of post-removal site control costs for a 30-year period were calculated using a 7 percent
discount rate.
Alternative 2: Stream Channel Reconstruction
The estimated cost for this alternative would be $54,900. Estimated cost details are
summarized in Table 19.
Alternative 3: Stream Channel Reconstruction and Regrading
The estimated cost for this alternative would be $55,400. Estimated cost details are
summarized in Table 20.
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Alternative 4: Waste Rock Removal
The estimated cost for this alternative would be $99,300. Estimated cost details are
summarized in Table 21.
Nugget Gulch Waste Rock
Present worth costs range from $299,026 (Alternative 2) to $800,012 (Alternative 4). The
present worth of post-removal site control costs for a 30-year period were calculated using a 7
percent discount rate.
Alternative 2: Diversion Ditches
The estimated cost for this alternative would be $299,026. Estimated cost details are
summarized in Table 22.
Alternative 3: Diversion Ditches and Waste Rock Regrading
The estimated cost for this alternative would be $369,702. Estimated cost details are
summarized in Table 23.
Alternative 4: Diversion Ditches. Consolidation, and Cover
The estimated cost for this alternative would be $800,012. Estimated Cost details are
summarized in Table 24.
AY-Minnie Waste Rock
Present worth costs range from $169,081 (Alternative 2) to $240,820 (Alternative 4). The
present worth of post-removal site control costs for a 30-year period were calculated using a 7
percent discount rate.
Alternative 2: Diversion Ditches
The estimated cost for this alternative would be $169,081. Estimated cost details are
summarized in Table 25.
Alternative 3: Diversion Ditches and Regrading
The estimated cost for this alternative would be $ 184,131. Estimated cost details are
summarized in Table 26.
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Alternative 4: Diversion Ditches and Road Reconstruction
The estimated cost for this alternative would be $240,820. Estimated cost details are
summarized in Table 27.
Iron Hill Waste Rock
Present worth costs range from $117,189 (Alternative 2) to $227,759 (Alternative 4). The
present worth of post-removal site control costs for a 30-year period were calculated using a 7
percent discount rate.
Alternative 2: Diversion Ditches
The estimated cost for this alternative would be $117,189. Estimated cost details are
summarized in Table 28.
Alternatives: Regrading and Cover
The estimated cost for this alternative would be $159,776. Estimated cost details are
summarized in Table 29.
Alternative 4: Waste Rock Consolidation
The estimated cost for this alternative would be $227,759. Estimated cost details are
summarized in Table 30.
California Gulch Waste Rock
Present worth costs range from $67,083 (Alternative 3) to $548,341 (Alternative 2). The present
worth of post-removal site control costs for a 30-year period were calculated using a 7 percent
discount rate.
Alternative 2: Channel Reconstruction
The estimated cost for this alternative would be $548,341. Estimated cost details are
summarized in Table 31.
Alternative 3: Selected Regrading
The estimated cost for this alternative would be $67,085. Estimated cost details are
summarized in Table 32.
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Alternative 4: Selected Waste Ro^k Removal
The estimated cost for this alternative would be $425,731. Estimated cost details are
summarized in Table 33.
Fluvial Tailing Site 4
Present worth costs range from $2,226,929 (Alternative 3) to $2,653,493 (Alternative 5). The
present worth of post-removal site control costs for a 30-year period were calculated using a 7
percent discount rate.
Alternative 2: Channel Reconstruction and Revegetation
The estimated cost for this alternative would be $2,393,933. Estimated cost details are
summarized in Table 34.
Alternative 3: Channel Reconstruction. Sediment Dams and Wetlands
The estimated cost for this alternative would be $2,226,929. Estimated cost details are
summarized in Table 35.
Alternative 4: Channel Reconstruction. Revegetation. Sediment Dams and Wetlands
The estimated cost for this alternative would be $2,544,293. Estimated cost details are
summarized in Table 36.
Alternative 5: Channel Reconstruction. Revegetation. Sediment Dams. Wetlands and
Selected Surface Material Removal
The cost estimate for this alternative would be $2,653,493. Estimated cost details are
summarized in Table 37.
83.8 STATE ACCEPTANCE
The State has been consulted throughout this process and concurs with the Selected Remedies.
8J.9 COMMUNITY ACCEPTANCE
Public comment on the RI/FS and Proposed Plan was solicited during a formal public comment
period extending from January 15 through February 13,1998. The community is assumed to be
generally supportive of the selected remedial alternatives. There were no written comments
received during the public comment period. Questions received during the public meeting
pertained to clarification of specific issues associated with the selected remedial alternatives.
There were no objections to the selected remedial alternatives and questions posed during the
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public meeting appeared to be satisfactorily addressed during the meeting. The Responsiveness
Summary addresses all comments received during the public comment period.
8.4 EVALUATING THE ALTERNATIVES WITH THE WAMP CRITERIA
A comparative analysis of the Garibaldi and Agwalt mine sites removal action alternatives using '
the WAMP criteria was performed in the FFS. The Action Memorandums (EPA, 1995a and
1996a) implemented the Removal Action for the Garibaldi and Agwalt mine sites. The selected
alternatives for the Garibaldi and Agwalt complied with the WAMP criteria.
What follows is a brief summary of the evaluation and comparison of the alternatives for the
waste rock (Garibaldi Sub-basin, Printer Girl, Nugget Gulch, A Y-Minnie, Iron Hill and
California Gulch) and the Fluvial Tailing Site 4 located within OU4. Additional details
evaluating the alternatives are presented in the FFS. Tables 38 through 44 provide a comparison
of the ability of the remedial alternatives to achieve WAMP criteria. Information for this section
was obtained from the FFS for Upper California Gulch (OU4) (TerraMatrix/SMI, 1998).
8.4.1 SURFACE EROSION STABILITY
This criterion evaluates surface erosion stability through the development of surface
configurations and implementation of erosion protection.
Garibaldi Sub-basin Waste Rock
Because the "no action" alternative (Alternative 1) does not provide erosional stability it is not
evaluated further in this analysis as an option for this site. For Alternatives 2 and 3 (diversion
channels) will divert surface runon away from the waste rock, reducing surface erosion. Waste
rock removal from the floodplain (Alternative 3) would most likely provide the highest level of
erosional protection.
Printer Girl Waste Rock
Because the "no action" alternative (Alternative 1) does not provide erosional stability, it is not
evaluated further in this analysis as an option for this site. For Alternative 2 the potential for
surface erosion would be reduced through stream channel reconstruction due to a decrease in run
onto the waste rock pile. Alternative 3 would provide a greater reduction in long-term surface
erosion because the side slopes of the waste rock pile would be regraded increasing erosional
stability. Alternative 4 waste rock removal would provide the highest level of erosional stability.
Nugget Gulch Waste Rock
Because the "no action" alternative (Alternative 1) does not provide erosional stability it is not
evaluated further in this analysis as an option for this site. For Alternative 2 the potential for
surface erosion would be reduced through the construction of diversion ditches due to a decrease
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in runon to the waste rock pile. The regraded pile (Alternative 3) would be designed to be stable
during the 100-year storm. The consolidated and covered pile (Alternative 4) would provide the
highest level of erosional stability.
AY-Minnie Waste Pile
Because the "no action" alternative (Alternative 1) does not provide erosional stability it is not
evaluated further in this analysis as an option for this site. For Alternatives 2 and 4 (diversion
ditches) will divert surface runon away from the waste rock, reducing surface erosion. For
Alternative 3 the regraded pile would be designed to be stable during the 100-year storm.
Iron Hill Waste Rock
Because the "no action" alternative (Alternative 1) does not provide erosional stability it is not
evaluated further in this analysis as an option for this site. For Alternative 2 diversion channels
would reduce the potential for surface erosion due to a decrease in runon to the waste rock pile.
The regraded pile (Alternative 3) would be designed to be stable during the 100-year storm.
Alternative 4 (waste rock consolidation/simple cover) would provide the highest level of
erosional stability.
California Gulch Waste Rock :
Because the "no action" alternative (Alternative 1) does not provide erosional stability it is not
evaluated further in this analysis as an option for this site. For Alternative 2 diversion channels
will divert surface water runon away from the waste rock, reducing surface erosion. Selected
regrading of the waste rock pile (Alternative 3) would be designed to be stable during the 500-
year storm. Alternative 4, selected waste rock removal, would reduce surface erosion.
Fluvial Tailing Site 4
Because the "no action" alternative (Alternative 1) does not provide erosional stability it is not
evaluated further in this analysis as an option for this site. For Alternatives 2 through 5 the
surface soils would be remediated to remain stable during the 100-year storm event. The
reconstruction of the stream channel of upper California Gulch would be designed to remain
stable during the 500-year flood.
8.4.2 SLOPE STABILITY
This criterion evaluates geotechnical stability through the development of embankments or slope
contours to meet factors of safety criteria defined by the WAMP.
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Garibaldi Sub-basin Waste Rock
In order to meet WAMP criteria for slope stability (Alternatives 2 and 3) a retaining wall would
be required to stabilize the oversteepened slope at the toe of the slope (Pile 109A).
Printer Girl Waste Rock
The slope stability of the waste rock pile would not be changed by implementation of Alternative
2. For Alternative 3 the slope stability of the regraded waste rock pile would be enhanced due to
the flattening of the side slopes. Alternative 4 would eliminate slope stability issues by removal
of the waste rock source.
Nugget Gulch Waste Rock
The slope stability of the waste rock pile would not be changed by implementation of Alternative
2. Slope stability of regraded waste rock piles (Alternative 3) would be increased by flattening
the side slopes. Consolidation and cover (Alternative 4) at pile UCG-71 would provide the
highest level of slope stability. Alternative 4 would provide embankment slopes regraded to 3:1
or flatter to meet WAMP criteria.
AY-Minnie Waste Rock
For Alternative 2 slope stability of the waste rock pile would not be changed. Slope stability
would be improved by regrading the waste piles (Alternative 3) and flattening the side slopes.
Although Alternative 4 would not improve the slope stability of the waste rock pile, realignment
of County Road 2 would reduce the risk associated with the eventual failure of the timber
cribbing.
Iron Hill Waste Rock
The slope stability of the waste rock pile would not be changed by implementation of Alternative
2. Slope stability of regraded waste rock (Alternative 3) and consolidated waste rock
(Alternative 4) would be enhanced due to flattening of side slopes.
California Gulch Waste Rock
The slope stability of the waste rock pile would not be improved by implementation of
Alternative 2. For Alternative 3 the stability of regraded waste piles would be improved by the
reduction of side slopes. Alternative 4 would remove any slope stability issues at the waste rock
piles removed. Existing stability problems, if any, would remain at those piles not removed.
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Fluvial Tailing Site 4
Due to the fairly flat topography of the fluvial tailing within OU4, Alternatives 2 through 5 pose
little risk of large scale stability problems. Any channelization work would be designed and
completed such that the stability of the fluvial tailing would not be adversely affected.
8.43 FLOW CAPACITY AND STABILITY
This criterion evaluates the capacity and erosional stability of retained structures, diversion
ditches, or reconstructed stream channels.
Garibaldi Sub-basin Waste Rock
For Alternatives 2 and 3 the diversion channels and culverts will be designed and constructed to
adequately convey and be stable under the 100-year runoff event.
Printer Girl Waste Rock
For Alternatives 2 and 3 the diversion ditches would be sized to adequately convey and be stable
for the 100-year flood event according to WAMP criteria. For Alternative 4 the removal area
would be stabilized for the 100 year flood.
Nugget Gulch Waste Rock
For Alternatives 2 through 4 the diversion channels would be designed to adequately convey and
be stable for the 100-year flood event according to WAMP criteria.
Iron Hill Waste Rock
For Alternative 2 the diversion ditches would be adequately sized to provide stability for the 100-
year flood event according to WAMP criteria. The pile cover (Alternatives 3 and 4) would also
be designed to remain stable during the 100-year storm as per WAMP criteria.
California Gulch Waste Rock
For Alternatives 2 and 3 stream channel reconstruction and stabilization measures will be
designed to remain stable during the 500-year flood event. For Alternative 4 the removal area
would be stabilized for the 500-year flood.
Fluvial Tailing Site 4
For Alternatives 2 through 5 the stream channelization and stabilization of adjacent flood plain of
upper California Gulch would be designed to remain stable during and convey the 500-year
flood.
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8.4.4 SURFACE WATER AND GROUNDWATER LOADING REDUCTION
This criterion evaluates the extent to which an alternative would ensure the reduction of mass
loading of COCs resulting from runon, runoff, and infiltration from source areas.
Garibaldi Sub-basin Waste Rock
By implementing Alternatives 2 and 3 the range of COC loading reduction to surface water
would be from 78 to 83 percent for metals and sulfate and a minimal reduction of TSS.
Printer Girl Waste Rock
For Alternatives 2 through 4 the reduction in loading of COCs to groundwater was not calculated
due to water balance calculations indicating that for existing conditions this site is a groundwater
discharging area. By implementing Alternatives 2 and 3 the range of COC loading reduction to
surface water would be from 81.5 percent to 83.3 percent for metals and sulfate and a reduction
of 0.0 percent (Alternative 2) and 14.2 percent (Alternative 3) for TSS. Alternative 4 would
provide the highest reduction for COC loading to surface water; 100.0 percent for metals and
sulfate and a reduction of 79.3 percent for TSS.
Nugget Gulch Waste Rock
The estimated reduction in the loading of COCs to groundwater ranges from 51.4 to 68.4 percent
resulting from implementation of Alternative 2. The estimated range of COC loading reduction
to surface water for Alternative 2 would be from 7.9 to 78.9 percent for metals and sulfate and a
reduction of 0.0 percent for TSS. By implementing Alternative 3 the reduction in loading of
COCs to groundwater is estimated to range from 52.4 to 69.0 percent. For Alternative 3 the
range of COC loading reduction to surface water would be from 8.0 percent to 79.4 percent for
metals and sulfate and a reduction of 10.0 percent for TSS. The reduction in loading of COCs to
groundwater is estimated to range from 28.5 percent to 52.1 percent resulting from
implementation of Alternative 4. The range of COC loading reduction to surface water for this
alternative would be from 8.8 percent to 79.9 percent for metals and sulfate and a reduction of
82.0 percent for TSS.
AY-Minnie Waste Rock
For Alternatives 2 through 4 the reduction in loading of COCs to groundwater is estimated to
range from 5.7 percent to 40.0 percent resulting from implementation of these alternatives. The
range of COC loading reduction to surface water for Alternatives 2 through 4 would be from
60.6 percent to 61.8 percent for metals and sulfate and a reduction of 0.0 percent for TSS.
However, implementation of Alternative 4 would result in an estimated 70.0 percent loading
reduction to surface water for TSS.
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Iron Hill Waste Rock
Alternatives 2 and 3 would provide a similar reduction in loading of COCs to groundwater. The
estimated reduction in groundwater loading ranges from 12.4 percent (Alternative 3) to 13.1
percent (Alternative 2). Alternative 4 would provide the greatest reduction in loading COCs to
groundwater (21.2 to 99.1 percent). Alternatives 2 and 3 would provide a similar reduction in
loading COCs to surface water. The estimated reduction in surface water loading would be 20.8
percent for metals and sulfate (Alternative 2) and -13.6 percent for metals and sulfate by
implementing Alternative 3. For Alternative 2 there would be an estimated 0.0 percent reduction
in surface water loading for TSS and an 85.4 percent reduction for Alternative 3. Implementation
of Alternative 4 would result in an estimated increase of metals and sulfate COC loadings to
surface water that would range from 79.5 to 99.4 percent, however, a reduction of 92.0 percent
for TSS.
California Gulch Waste Rock
For Alternative 2 the reduction in loading COCs to groundwater is estimated to range from 12.5
to 18.5 percent. The range of COC loading reduction to surface water for Alternative 2 would be
57.1 to 60.0 percent for metals and sulfate and a 0.0 percent reduction for TSS. By
implementing Alternative 3 the reduction in loading of COCs to groundwater is estimated to
range from 13.0 percent to 17.0 percent. The estimated range of COC loading reduction to
surface water would be from 42.9 to 46.7 percent for metals and sulfate and a 2.5 percent
reduction for TSS from implementation of this alternative. Implementation of Alternative 4
would result in the estimated reduction in loading of COCs to groundwater from 15.0 to 20.0
percent. The range of COC loading reduction to surface water for Alternative 4 would be from
52.4 percent to 58.9 percent for metals and sulfate and a reduction of 42.3 percent for TSS.
Fluvial Tailing Site 4
For alternatives 2 through 5 the reduction in loading of COCs to groundwater is estimated to
range from 61.0 to 80.9 percent resulting from implementation of these alternatives. The range
of COC loading reduction to surface water for Alternatives 2 through 5 would be from 57.4
percent to 57.8 percent for metals and sulfate. However, the estimated loading reduction to
surface water for TSS would range from 68.2 percent (Alternative 3) to 97.8 (Alternatives 4 and
5).
8.4.5 TERRESTRIAL ECOSYSTEM EXPOSURE
This criterion evaluates the ability of each alternative to reduce risk to the terrestrial ecosystem
within OU4.
Garibaldi Sub-basin Waste Rock
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Implementation of Alternatives 2 and 3 would reduce risk to the terrestrial ecosystem by
reducing the risk for ingestion of contaminated surface water.
Printer Girl Waste Rock
Implementation of Alternatives 2 and 3 would reduce risk to the terrestrial ecosystem by
reducing the risk for ingestion of contaminated surface water. However, implementation of
Alternative 4 (waste rock removal) would eliminate risk due to direct exposure to waste rock at
the Printer Girl site.
Nugget Gulch Waste Rock
By reducing the risk for ingestion of contaminated surface water, implementation of Alternatives
2 and 3 would reduce risk to the terrestrial ecosystem. However, through construction of a cover
(Alternative 4) risk due to direct exposure of the waste rock at the Nugget Gulch site would be
eliminated.
AY-Minnie Waste Rock
Implementation of Alternatives 2 through 4 would reduce risk to the terrestrial ecosystem,
through decreasing the risk of ingestion of contaminated surface water.
Iron Hill Waste Rock
Implementation of Alternative 2 would reduce the risk of ingestion of contaminated surface
water. However, through the construction of a cover, Alternatives 3 and 4 would reduce risk due
to direct exposure of waste rock.
California Gulch Waste Rock
Implementation of Alternatives 2 and 3 would reduce risk to the terrestrial ecosystem by
reducing the risk for ingestion of contaminated surface water. Alternative 4 (waste rock
removal) would eliminate any risk due to direct exposure to waste rock.
FJuvial Tailing Site 4
For Alternatives 2 through 5, erosion control, regrading and revegetation would significantly
reduce exposure pathways due to erosion and ponded water and reduce exposure due to leaching
of metals, therefore the potential risk to the terrestrial ecosystem would be reduced. These
alternatives would have a limited effect on direct exposure pathways due to contact with the soil.
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8.4.6 NON-RESIDENTIAL SOILS
This criterion is not applicable. The sources of contamination at OU4 are waste rock piles and
fluvial tailing material, not non-residential soils. Non-residential soils are not a source of
contamination within OU4.
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9.0 SELECTED REMEDY
An Action Memorandum (EPA, 1995a) was issued on August 4, 1995 by the EPA that selected
the following as the Removal Action for the Garibaldi Mine area:
Alternative 2: Diversion Channels, Portal Collection and Groundwater Interception. This
alternative consists of constructing a portal collection system for the collapsed Garibaldi Mine
portal, approximately 1,960 linear feet of concrete-line channel, and two groundwater
interception trenches constructed to intercept and divert surface and groundwater flow around the
Garibaldi waste rock pile.
The proposal for the Removal Action for the Garibaldi Mine was released for public comment in
1995 and implementation of the Removal Action was initiated during the Fall of 1995.
An Action Memorandum (EPA, 1996a) was issued on July 19, 1996 by the EPA that selected the
following as the removal action for the Agwalt Mine site:
Alternative 2: Diversion Ditches and Portal Diversion. This alternative consists of constructing
approximately 1,000 linear feet of concrete-lined channels to prevent surface water runon to the
piles and a portal discharge collection system for the collapsed Agwalt Mine portal.
The proposal for the Removal Action for the Agwalt Mine was released for public comment in
1996 and implementation was initiated in the fall of 1996.
Based upon consideration of CERCLA requirements, the detailed analysis of alternatives, and
public comments, EPA has determined that the following alternatives are the appropriate
remedies for the waste rock (Garibaldi Sub-basin, Printer Girl, Nugget Gulch, AY-Minnie, Iron
Hill and California Gulch) and the Fluvial Tailing Site 4 located within OU4:
Garibaldi Sub-basin Waste Rock: Alternative 2 - Diversion of Surface Water and Stream
Channel Reconstruction
Printer Girl Waste Rock: Alternative 4 - Waste Rock Removal
Nugget Gulch Waste Rock: Alternative 4 - Diversion Ditches, Consolidation and
Cover.
AY-Minnie Waste Rock: Alternative 4 - Diversion Ditches and Road Relocation
Iron Hill Waste Rock: Alternative 3 - Regrade and Cover
California Gulch Waste Rock: Alternative 2 - Stream Channel Reconstruction
Fluvial Tailing Site 4: Alternative 5 - Channel Reconstruction, Revegetation,
Sediment Dams, Wetlands and Selected Surface Material
Removal.
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These Selected Remedies will reduce risk to human health and the environment and meet RAOs
described earlier through the following:
• Provides the highest level of permanence and long-term effectiveness with the
greatest reduction of infiltration into the waste rock.
• Meets or exceeds all of the stability requirements predicated in the WAMP and
reduces the present risk to the terrestrial ecosystem.
• Eliminates airborne transport of waste rock particles and minimizes both the
erosion of tailings materials and deposition into local water courses and the
leaching and migration of metals into groundwater and surface water.
• Controls the risks defined by the risk assessment including ingestion of surface
tailings by terrestrial wildlife, contact of plants and soil fauna with surface
tailings, and ingestion of surface water by wildlife.
These Selected Remedies best meet the entire range of selection criteria and achieve, in EPA's
determination, the appropriate balance considering site-specific conditions and criteria identified
in CERCLA, the NCP and the WAMP, as provided in Section 10.0, Statutory Determinations.
9.1 REMEDIES FOR THE WASTE ROCK AND FLUVIAL TAILING WITHIN OU4
The following sections will provide a detailed description of the Selected Remedies for the waste
rock and Fluvial Tailing Site 4 within Operable Unit 4.
9.1.1 REMEDY FOR THE GARIBALDI SUB-BASIN WASTE ROCK
The selected remedy would consist of constructing approximately 850 feet diversion channels to
reduce surface water runon to the UCG-109A waste rock pile. The improvement of
approximately 475 feet of roadway side ditch and the installation of one culvert would reduce
leaching and erosional releases associated with surface flow. Approximately 225 feet of stream
channel will be reconstructed around UCG-109A (Figure 10) to prevent erosion.
9.1.2 REMEDY FOR THE PRINTER GIRL WASTE ROCK
The Selected Remedy would consist of excavating and consolidating the lowermost portion of
the Printer Girl waste rock (UCG-92A) onto waste rock pile UCG-71 (Colorado No. 2). The
remaining waste rock material will be regraded and the remaining disturbed area ( "1.1 acres)
revegetated to increase stability and promote non-erosive runoff. Two diversion ditches would
be constructed and armored with riprap to control surface water runon to the regraded disturbed
areas (Figure 11).
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9.13 REMEDY FOR THE NUGGET GULCH WASTE ROCK
The Selected Remedy would consist of excavating and consolidating waste rock piles UCG-74
(Rubie), UCG-76 (Adirondack), UCG-77 (Colorado No. 2 east), and UCG-85 (North Mike) onto
waste rock pile UCG-71 (Colorado No. 2). UCG-71 would be regraded and a simple cover (18
inches of soil, the borrow source will be determined during design) placed over the consolidated
material. The cover surface on UCG-71 will be revegetated or covered with rock material.
Disturbed areas which were cleared of waste rock would be terraced, soils amended and
revegetated. Diversion ditches would be constructed to control surface water runon (Figure 12).
9.1.4 REMEDY FOR THE AY-MINNIE WASTE ROCK
The Selected Remedy would consist of constructing diversion ditches to reduce surface water
runon to the AY-Minnie waste rock pile and reduce leaching and erosional releases associated
with surface flow. Lake County Road 2 will be realigned to provide area for construction of a
sediment pond and further add protection from stability failures of the timber cribbing without
destroying the mining heritage and cultural resources of this mining area (Figure 13).
9.1.5 REMEDY FOR THE IRON HILL WASTE ROCK
The Selected Remedy would consist of regrading waste rock piles UCG-12 (Mab/Castle View).
A simple cover (18 inches of soil, the borrow source will be determined during design) will be
placed on UCG-12 along with revegetation of the surrounding disturbed areas (Figure 14) and
revegetation or placement of rock on the cover surface. Implementation of this alternative will
minimize infiltration at UCG-12, reduce leaching, increase stability of the regraded waste rock
and promote non-erosive runoff from the regraded waste rock pile surfaces.
9.1.6 REMEDY FOR THE CALIFORNIA GULCH WASTE ROCK
The Selected Remedy would consist of reconstructing and stabilizing approximately 2,150 feet
of the Upper California Gulch stream channel (Figure 15). Implementation of this alternative
would stabilize the stream channel for the 500-year flood event and reduce contact of waste rock
with surface flows in upper California Gulch, minimizing leaching and erosional releases
associated with surface flow. Specific details of channel reconstruction will be determined
during design. This alternative has also been incorporated into the selected remedy for Fluvial
Site 4.
9.1.7 REMEDY FOR FLUVIAL TAILING SITE 4
The Selected Remedy would consist of reconstructing the Upper California Gulch stream
channel and regrading the channel spoil material and selected fluvial tailing areas. Eight
sediment dams and approximately 2.5 acres of wetlands would be constructed along the channel
(Figure 16). Implementation of this alternative would stabilize the stream channel and adjacent
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floodplain to convey the 500-year flood event and reduce contact of surface flows with fluvial
tailing in Fluvial Tailing Site 4, promote non-erosive flow, and minimize leaching and erosional
releases from the site. Specific details of channel reconstruction will be determined during
design.
9.2 CONTINGENCY MEASURES AND LONG TERM MONITORING
Specific water quality goals for surface streams and heavy metals contamination have not been
established at this time. EPA has agreed to establish specific surface and groundwater
requirements at a later date when EPA, and CDPHE have determined the allowable water quality
standards pursuant to OU12 (Site Wide Water Quality).
Pre-remedial data will be compared to water quality and sediment data collected after the
Selected Remedy has been implemented. An evaluation of the degree of surface water-quality
improvement will be made by EPA and CDPHE at that time. If the improvement in Upper
California Gulch surface water quality is not considered sufficient to meet OU12 water quality
standards, additional response actions may be required.
The Selected Remedies will be designed to minimize active maintenance requirements. Post-
closure maintenance of the covers and diversion channels will be used to ensure that the integrity
and permanence of the covers and diversion channels are maintained. Provisions for surveillance
and repair/cleanout will be established for sediment ponds and other features requiring routine
maintenance.
Because the Upper California Gulch waste rock and fluvial tailing will remain on site, the
Selected Remedies will require a five-year review under Section 121(c) of CERCLA and Section
300.430(f)(4)(ii) of the NCP. The five-year review includes a review of the groundwater and
surface water monitoring data, inspection of the integrity of the covers, diversion channels and
reconstructed channels, and an evaluation as to how well the Selected Remedies are achieving
the RAOs and ARARs that they were designed to meet.
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10.0 STATUTORY DETERMINATIONS
Under CERCLA Section 121, EPA must select a remedy that is protective of human health and
the environment; that complies with ARARs; is cost effective; and utilizes permanent solutions,
and alternative treatment technologies, or resource recovery technologies to the maximum extent
practicable. In addition, CERCLA includes a preference for remedies that include treatment
which permanently and significantly reduces the volume, toxicity, or mobility of hazardous
wastes as a principal element. The Selected Remedies do not satisfy the statutory preference for
treatment as a principal element of the remedy. In narrowing the focus of the FFS, treatment of
the Upper California Gulch waste rock and fluvial tailing material was determined to be
impracticable. The following sections discuss how the Selected Remedies meets statutory
requirements. A similar determination was made in selecting the Removal Actions for the
Garibaldi Mine area and the Agwalt Mine site as presented in their respective Action
Memorandums (EPA, 1995a and EPA, 1996a).
10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The following section summarizes the estimated effectiveness of the Selected Remedies for the
waste rock and Fluvial Site 4 located within OU4 for the protection of human health and the
environment.
Garibaldi Sub-basin Waste Rock: Alternative 2 - Diversion of Surface Water and Stream
Channel Reconstruction
The Selected Remedy protects human health and the environment through reducing direct
contact with contaminants at the site. The Selected Remedy uses diversion channels and channel
reconstruction to control contaminant movement and effectively reduce exposure to
contaminants. The range of COC loading reduction to surface water would be from 78 to 83
percent for metals and sulfate and a minimal reduction of TSS. Potential risk to the terrestrial
ecosystem due to ingestion or exposure to waste rock would be reduced through stream channel
reconstruction by the Selected Remedy (TerraMatrix/SMI, 1998).
Printer Girl Waste Rock: Alternative 4 - Waste Rock Removal
The Selected Remedy protects human health and the environment through the prevention of
direct contact of contaminants at the site. The Selected Remedy uses source removal to
effectively reduce direct contact with contaminants at the site. The reduction in total loading of
COCs to groundwater was not calculated due to water balance conditions indicating that this site
is a groundwater discharging area. Loading of COCs to surface water runoff from the waste rock
was estimated to be reduced 100.0 percent for metals and sulfate and a reduction of 79.3 percent
for TSS. Potential risk to the terrestrial ecosystem due to ingestion or exposure to waste rock
would be eliminated by the Selected Remedy since the waste rock would be removed
(TerraMatrix/SMI, 1998).
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Nugget Gulch Waste Rock: Alternative 4 - Diversion Ditches. Consolidation and Cover
The Selected Remedy protects human health and the environment through the prevention of
direct contact with contaminants at the site. The Selected Remedy uses diversion ditches and an
engineered cover to effectively control contaminant movement and reduce direct contact,
ingestion, and inhalation of all contaminants. The reduction in loading of COCs to groundwater
is estimated to range from 28.5 to 52.1 percent resulting from implementation of the Selected
Remedy. The range of COC loading reduction to surface water runoff from the waste rock
would be from 8.8 to 79.9 percent for metals and sulfate and a reduction of 82.0 percent for TSS.
Potential risk to the terrestrial ecosystem due to ingestion or exposure to waste rock would be
eliminated by the Selected Remedy since the waste rock would be covered (TerraMatrix/SMI,
1998).
AY-Minnie Waste Rock: Alternative 4 - Diversion Ditches and Road Relocation
The Selected Remedy protects human health and the environment through reducing direct
contact with contaminants at the site. The Selected Remedy uses diversion ditches to control
contaminant movement from the source area and effectively reduce exposure to contaminants.
The reduction in loading of COCs to groundwater is estimated to range from 5.7 to 40.0 percent
resulting from implementation of the Selected Remedy. Loading of COCs to surface water
runoff from the waste rock was estimated to range from 60.6 to 61.8 percent for metals and
sulfate and a reduction of 70.0 percent for TSS. Potential risk to the terrestrial ecosystem due to
ingestion or exposure to waste rock would be reduced through constructing diversion ditches by
the Selected Remedy (TerraMatrix/SMI, 1998).
Iron Hill Waste Rock: Alternative 3 - Regrade and Cover
The Selected Remedy protects human health and the environment through the prevention of
direct contact with contaminants at the site. The Selected Remedy uses regrading and an
engineered cover to effectively reduce direct contact, ingestion and inhalation of contaminants.
The reduction in total loading of COCs to groundwater is estimated to be 12.4 percent resulting
from implementation of the Selected Remedy. The range of COC loading reduction to surface
water is estimated to be 13.6 percent for metals and sulfate and a reduction of 85.4 percent for
TSS. Potential risk to the terrestrial ecosystem due to ingestion or exposure to waste rock would
be eliminated by the Selected Remedy since the waste rock would be covered (TerraMatrix/SMI,
1998).
California Gulch Waste Rock: Alternative 2 - Stream Channel Reconstruction
The Selected Remedy protects human health and the environment through reducing direct
contact with contaminants at the site. The Selected Remedy uses channel reconstruction to
control contaminant movement and effectively reduce exposure to contaminants. The reduction
in loading of COCs to groundwater is estimated to range from 12.5 to 18.5 percent resulting from
implementation of the Selected Remedy. The range of COC loading reduction to surface water
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would be from 57.1 to 60.0 percent for metals and sulfate and a reduction of 0.0 percent for TSS.
Potential risk to the terrestrial ecosystem due to ingestion or exposure to waste rock would be
reduced through stream channel reconstruction by the Selected Remedy (TerraMatrix/SMI,
1998).
Fluvial Tailing Site 4: Alternative 5 - Channel Reconstruction. Revegetation. Sediment Dams.
Wetlands and Selected Surface Material Removal
The Selected Remedy protects human health and the environment through reducing direct
contact with contaminants at the site. The Selected Remedy uses channel reconstruction
revegetation and sediment dams to control contaminant migration and reduce exposure to
contaminants. The reduction in loading of COCs to groundwater is estimated to range from 61.0
to 80.9 percent resulting from implementation of this alternative. The range of COC loading
reduction to surface water would be from 57.4 to 57.8 percent for metals and sulfate and a
reduction of 97.8 percent for TSS. Potential risk to the terrestrial ecosystem due to ingestion or
exposure would be reduced by decreasing exposure pathways due to erosion and ponded water
by the Selected Remedy (TerraMatrix/SMI, 1998).
10.2 COMPLIANCE WITH ARARs
The selected Remedy for OU-4 will comply with all ARARs identified in Appendix A to
this ROD. No waiver of ARARs is expected to be necessary. Remediation of Site-wide
groundwater and surface water has been deferred to OU-12, Site-wide Ground Water and
Surface Water Quality (USCD, 1994). Remedial work conducted pursuant to OU-12 will be
addressed under a separate ROD. If a ROD addressing Site-wide surface and ground waters
selects additional source remediation, the responsible settling defendant in whose work area such
source remediation is required shall be responsible for such additional source remediation
(USCD, 1994).
10.3 COST EFFECTIVENESS
EPA has determined that all of the Selected Remedies for waste rock and Fluvial Tailing Site 4
within OU4 are cost effective in mitigating the principal risks posed by contaminated tailings.
Section 300.430(f)(ii)(D) of the NCP requires evaluation of cost effectiveness. Overall
effectiveness is determined by the following three balancing criteria: long-term effectiveness
and permanence; reduction of toxicity, mobility, and volume through treatment; and short-term
effectiveness. Overall effectiveness is then compared to cost to ensure that the remedy is cost
effective. The Selected Remedies meet the criteria and provide for overall effectiveness in
proportion to their cost. Specific cost estimates for all of the Selected Remedies include:
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Garibaldi Sub-basin Waste Rock Alternative 2: $ 130,510
Printer Girl Waste Rock Alternative 4: $ 99,288
Nugget Gulch Waste Rock Alternative 4: $ 800,012
AY-Minnie Waste Rock Alternative 4: $ 240,820
Iron Hill Waste Rock Alternative 3: $ 159,776
California Gulch Waste Rock Alternative 2: $ 548,341
Fluvial Tailing Site 4 Alternative 5: $2,653,493
The estimated combined cost for all of the Selected Remedies for waste rock and fluvial tailing
material within OU4 is $4.08 million. The cost estimated includes periodic inspection.
To the extent that the estimated cost of the Selected Remedies exceed the cost for other
alternatives, the difference in cost is reasonable when related to the greater overall effectiveness
achieved by the Selected Remedies.
10.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE
TREATMENT TECHNOLOGIES (OR RESOURCE RECOVERY
TECHNOLOGIES) TO THE MAXIMUM EXTENT POSSIBLE
EPA has determined that the Selected Remedies represent the maximum extent to which
permanent solutions can be utilized in a cost effective manner for the waste rock and fluvial
tailing material within OU4.
Of those alternatives that are protective of human health and the environment and comply with
ARARs, EPA has determined that the Selected Remedies for the waste rock and fluvial tailing
material within OU4 provide the best balance of trade-offs in terms of long-term effectiveness
and permanence, treatment, implementability, cost, and state and community acceptance.
While the Selected Remedies for OU4 does not utilize the most permanent solution treatment or
complete removal, the use of engineered covers, diversion ditches, channel reconstruction,
revegetation and sediment dams provide a long-term effective and permanent barrier to
contaminated waste materials, thus reducing risk to an equivalent extent. Because the waste rock
and fluvial tailing materials will remain on site with no treatment, the Selected Remedies will
require a five-year review under Section 121(c) of CERCLA and Section 300.430(f)(4)(ii) of the
NCP.
10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
Various treatment options for the waste rock and fluvial tailing material were considered early in
the FS process; however, due to the nature and size of the waste rock and fluvial tailing, these
options were determined to be either technically impracticable and/or not cost-effective.
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11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The Selected Remedies for the waste rock and Fluvial Tailing Site 4 is the third response action
to be taken at OU4 of the California Gulch Superfund Site. The first action implemented the
Action Memorandum (EPA, 1995a) for the waste rock contained within the Garibaldi mine site
and was initiated during the fall of 1995. The second action implemented the Action
Memorandum (EPA, 1996a) for the waste rock contained within the Agwalt mine site and was
completed in the Fall of 1996, These removal actions are consistent with the Selected Remedies
for the waste rock and Fluvial Tailing Site 4 within OU4.
The Proposed Plan for Upper California Gulch, OU4 was released for public comment on
January 15, 1998. The Proposed Plan identified the following alternatives as the preferred
alternatives for the waste rock and fluvial tailing material within OU4:
• Garibaldi Sub-basin Waste Rock: Alternative 2 - Diversion of Surface Water and
Stream Channel Reconstruction
• Printer Girl Waste Rock: Alternative 4 - Waste Rock Removal
• Nugget Gulch Waste Rock: Alternative 4 - Diversion Ditches, Consolidation and
Cover
• AY-Minnie Waste Rock: Alternative 4 - Diversion Ditches and Road Relocation
• Iron Hill Waste Rock: Alternative 3 - Regrade and Cover
• California Gulch Waste Rock: Alternative 2 - Stream Channel Reconstruction
• Fluvial Tailing Site 4: Alternative 5 - Channel Reconstruction, Revegetation,
Sediment Dams, Wetlands and Selected Surface Material Removal
Comments received during the public comment period are addressed in the Responsiveness
Summary. The EPA determined that no significant changes to the remedy, as it was originally
identified in the Proposed Plan, are necessary.
Record of Decision
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12.0 REFERENCES
Abt, S.R., R.J. Wittier, J.F. Ruff, D.L. LaGrone, M.S. Khattak, J.D. Nelson, N.E. Hinkle, and
D. W. Lee. 1988. Development of Riprap Design Criteria by Riprap Testing in Flumes,
Phase II. U.S. Nuclear Regulatory Commission, Office of Nuclear Material Safety and
Safeguards NUREG/CR-4651, Vol. 2.
Engineering-Science, Inc. (ESI). 1986. Final Yak Tunnel/California Gulch Remedial
Investigation. Prepared for State of Colorado, Department of Law.
Foothills Engineering Consultants (FEC). 1996. Draft - Cultural Resources Investigation of
North Moyer, North Mike, andAgwalt Tunnel - Operable Unit 4, California Gulch
Superfund Site, Lake County, Colorado.
Golder and Associates (Golder). 1996a. Final-Surface Water Remedial Investigation Report,
California Gulch Site, Leadville, Colorado.
Golder and Associates (Golder). 1996b. Final-ffydrogeologic Remedial Investigation Report,
California Gulch Site, Leadville, Colorado.
Martorano, M.A. 1990. Addendum to Yak Tunnel Remedial Action Historic Resources Survey,
Lake County, Colorado.
P-III, Associates, Inc. (P-III). 1996a. Cultural Resource Inventory of Mining Waste rock Pile
92A and Potential Access Corridors in Operable Unit 4 of the California Gulch CERCLA
Site, Lake County, Colorado.
P-III, Associates, Inc. (P-III). 1996b. Cultural Resource Inventory of Select Waste Rock Piles
and Fluvial Tailing Locations in Operable Unit 4 of the California Gulch CERCLA Site,
Lake County, Colorado.
Shepherd Miller, Inc./TerraMatrix Inc. (SMI/TerraMatrix). 1994a. Draft Final - Field
Reconnaissance Survey of Mine Waste Piles Located Within the Upper California Gulch
Drainage. May.
Stephenson, D. 1979. Rockftll in Hydraulic Engineering, Developments in Geotechnical
Engineering, 27. E.T. Sevier, Scientific Publishing Co.
Stevens, M.A. and D.B. Simmons. 1971. River Mechanics, edited by Shen, H.W. Fort Collins,
Colorado: H.W. Shen.
Stoller. 1996. Screening Level Ecological Risk Assessment for Operable Unit No. 4, California
Gulch Superfund Site, Leadville, Colorado (SLERA).
Record or Decision
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TerraMatrix Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1995a. Final-Engineering
Evaluation/Cost Analysis for Garibaldi Mine Site Within Upper California Gulch
Operable Unit 4. July.
TerraMatrix Inc./Shepherd Miller Inc. (TerraMatrix/SMI). 1995b. Final Removal Action Design
Report Engineering Evaluation/Cost Analysis for Garibaldi Mine Site Within Upper
California Gulch Operable Unit 4. September.
TerraMatrix Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1995c. Removal Action Work Plan
Engineering Evaluation/Cost Analysis for Garibaldi Mine Site Within Upper California
Gulch Operable Unit 4. September.
TerraMatrix IncVShepherd Miller, Inc. (TerraMatrix/SMI). 1995d. Draft - Operable Units 4, 8.
and JO Reconnaissance Report. March.
TerraMatrix Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1996a. Final-Engineering
Evaluation/Cost Analysis for Whites Gulch Within Upper California Gulch Operable
Unit 4. July.
TerraMatrix Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1996b. Final Removal Action
Design Report Engineering Evaluation/Cost Analysis for Whites Gulch Site Within Upper
California Gulch Operable Unit 4.
TerraMatrix IncVShepherd Miller, Inc. (TerraMatrix/SMI). 1996c. Removal Action Work Plan
Engineering Evaluation/Cost Analysis for Agwalt Mine Site Within Upper California
Gulch Operable Unit 4.
TerraMatrix Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1998. Final Focused Feasibility
Study Upper California Gulch Operable Unit 4. January.
U.S. Army Corps of Engineers (COE). 1991. Flood Hydrograph Package, HEC-1. Hydrologic
Engineering Center.
U.S. Army Corps of Engineers (COE). 1990. Computation of Water Surface Profiles, HEC-2.
Hydrologic Engineering Center.
U.S. Environmental Protection Agency (EPA). 1989a. Draft - Phase II Remedial Investigation
Technical Memorandum 1986 -1987, California Gulch Site Leadville. Colorado.
U.S. Environmental Protection Agency (EPA). 1989b. Guidance on Preparing Superfund
Decision Documents: The Proposed Plan, The Record of Decision, Explanation of
Differences, The Record of Decision Amendment. Interim Final. EPA/540/G-89/007.
July.
Record of Decision
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U.S. Environmental Protection Agency (EPA). 1992. Supplemental Guidance to RAGS:
Calculating the Concentration Term. Office of Solid Waste and Emergency Response.
Office of Emergency and Remedial Response. Washington, D. C. Publication 9285.7-
081.
U.S. Environmental Protection Agency (EPA). 1993. Final Screening Feasibility Study for
Remediation Alternatives at the California Gulch NPL Site, Leadville, Colorado.
September.
U.S. Environmental Protection Agency (EPA) Region VIII. 1994. Calculating the
Concentration Term for Risk Assessment: Use of one "C" Term to Estimate a Lower
Average and an Upper RME Risk Range.
U.S. Environmental Protection Agency (EPA). 1995a. Action Memorandum for the Potentially
Responsible Party Financed Removal Action at the Garibaldi Mine Site Operable Unit 4.
U.S. Environmental Protection Agency (EPA). 1996a. Action Memorandum for the Potentially
Responsible Party Financed Removal Action in Whites Gulch Operable Unit 4.
U.S. Department of Commerce, Bureau of the Census. 1990. Selected Population and Housing
Characteristics, 1990.
U.S. District Court (USDC), District of Colorado. 1994. Civil Action No. 83-C-2388,
California Gulch Consent Decree. Consent with ASARCO, Inc., Resurrection Mining
Company, Newmont Mining Corporation, and the Res-ASARCO Joint Venture;
Appendix D: Work Area Management Plan for the California Gulch Superfund Site,
Implementation by Resurrection Mining Company. May.
Water, Waste and Land Inc. (WWL). 1990. California Gulch Hydrologic Investigation
Leadville Colorado.
Weston. 1991. Preliminary Human Health Baseline Risk Assessment for the California Gulch
NPL Site Leadville, Colorado.
Weston. 1995a Baseline Human Health Risk Assessment for the California Gulch Superfund
Site. Part C. Evaluation of Recreational Scenarios.
Weston. 1995b. Final Baseline Aquatic Ecological Risk Assessment, California Gulch NPL Site
(BARA).
Weston. 1997. Ecological Risk Assessment for the Terrestrial Ecosystem, California Gulch
NPL Site, Leadville. Colorado (ERA).
Record of Decision
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Woodward-Clyde Consultants (WCC). 1994a. Final - Tailings Disposal Area Remedial
Investigation Report, California Gulch Site, Leadville, Colorado.
Woodward-Clyde Consultants (WCC). 1994b. Final - Mine Waste Pile Remedial Investigation
Report, California Gulch Site, Leadville, Colorado.
Record of Decision
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FIGURES
Record of Decision
Upper California Gulch OU4
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C 0 L\0 R}A D 0
MOTTO9CMM
CALIFORNIA QULCH
SUPERFUNDStTE
SOURCE: TetfoMolru/SMI, 1998
GENERAL
LOCATION
-------
LECEND
taS
CALIFORNIA GULCH
SITE
OPERABLE UNITS
-------
SMELTER SU8SITE
WOOD TREATING SU8SITE
COZINCO SUBSITE
FICURC 2-1
PRELIMINARY SUBSITES
AS DEFINED BY USEPA
FORMER KOPPERS FACILITY
SAUOA. COLORADO
2?
-------
OU4 MINE
WASTE MATERIAL
-------
wmonc.
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-OM
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-------
E 1.767.000
C L'M.OOO
C 1.7H».OOn
C L">00
C 1.787.000
C 1.788.000
C 1.789.000
C I '90000
LEGEND
OU4BOUNDARY
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-------
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SOL SAMPl£ COUECTED
— PRINTER1 BOY FLUVIAL f
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onocnv
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NOTE
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WE« SMMFUO OURNQ tW IM6 PtAK fUW ntOOMMMMNCt.
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NUGGET GULCH
AND VICINITY
))THf LOCATION OF MMA
• AfMOXMATt
SOURCF' lerruMalm/SWl. 1998
-------
UCO-ee AND UN-3 ARE LOCATED TO
LEGEND
APPROXIMATELY 100 YARDS
CARBONATE }.
HHl , /'
OX BOUNDARY
SUMASM BOUNDARY
HJUVMLTMUNQ8rrE4
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* MONRXMNQ STATION
• /'' / /
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AND VICINITY
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-------
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+
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-------
LEGEND
OU« OOUVABT
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SAMPLE LOCATIONS '
-------
ngmto
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UCO-109A
ALTEHNATIVE 2
-------
LEGEND
NOTE*
1) KttSTI HBOC M STREAM CMMMEL (MO Of)
TO M HOVH> TO UCO-n.
4 CHMMB* OCTMU AMI WOX1N OH
PRINTER GIRL
MINE SITE
ALTERNATIVE 4
-------
UCO-74 7.0OO CY
UCO-78 800 CY
UCG-77 3f«CV
UC&45 tt.OCOCY
NUGGET
GULCH
ALTERNATIVE 4
-------
A-Y
MINNIE
ALTERNATIVE 4
-------
LEGEND
MOTE*
1) APPROXIMATE REQRAOE VOLUMEfc
cur MOOT
nil 1.080 cr
NET 100CY(FU)
WASTE ROCK PILE
UCG-12
ALTERNATIVE 3
-------
LEGEND
CALIFORNIA GULCH
WASTE ROCK
ALTERNATIVE 2
-------
trCONTCUtlJM
r CONTOUR IM
MTLMCAICA
OMTMMD
CALIFORNIA GULCH
WASTE ROCK
ALTERNATIVE 2
-------
LEGEND
UT CONTOUR LM
r CONTOUR LM
WCTUM>«MA
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PATH
CAUFORNIA GULCH
WASTE ROCK
ALTERNATIVE 2
-------
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SITE 4
ALTERNATIVE 5
-------
LEGEND
••jgjfj
FLUVIAL
SITE 4
ALTERNATIVE 5
-------
FLUVIAL
SfTE4
ALTERNATIVE 5
-------
RESPONSIVENESS SUMMARY
Recardof Decision
Upper California Gulch DIM
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TABLE OF CONTENTS
SECTION PAGE
1.0 INTRODUCTION RS-1
2.0 BACKGROUND ON RECENT COMMUNITY INVOLVEMENT RS-2
3.0 COMMENTS AT THE FORMAL PUBLIC MEETING RS-3
4.0 REMAINING CONCERNS RS-5
Record of Decision
Upper California G
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Upper California Gulch OU4 RS-i
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1.0 INTRODUCTION
The U.S. Environmental Protection Agency (EPA) has prepared the Responsiveness Summary to
document and respond to issues and comments raised by the public regarding the Proposed Plan
for the Upper California Gulch Operable Unit 4 (OU4) of the California Gulch Superrund Site.
Comments were received during the public meeting held on January 29, 1998 at 7:00 p.m. at the
Mining Hall of Fame in Leadville, Colorado. These comments, and responses to them, are
outlined in this document. By law, the EPA and the Colorado Department of Public Health and
Environment (CDPHE) must consider public input prior to making a final decision on a cleanup
remedy. Once public comment is reviewed and considered, the final decision on a cleanup
remedy will be documented in the Record of Decision (ROD).
This document includes the following sections:
• Background on Recent Community Involvement
• Summary of Comments Received During the Public Meeting and Agency Responses
• Remaining Concerns
Record of Decision
Upper California Gi
3279S P:\32IO-OI3VOU4\NEWROrWlODOU4-2.WPO
Upper Olifomia Gulch OU4 RS-1
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2.0 BACKGROUND ON RECENT COMMUNITY INVOLVEMENT
The OU4 Proposed Plan was published in January 1998 and describes the preferred cleanup
alternatives for waste rock and fluvial tailing. Based upon consideration of NCP and WAMP
criteria, EPA has determined that the following alternatives are the appropriate remedies for the
waste rock (Garibaldi Sub-basin, Printer Girl, Nugget Gulch, AY-Minnie, Iron Hill and
California Gulch) and the Fluvial Tailing Site 4 located within OU4:
Garibaldi Sub-basin Waste Rock: Alternative 2 - Diversion of Surface Water and Stream
Channel Reconstruction
Printer Girl Waste Rock:
Nugget Gulch Waste Rock:
AY-Minnie Waste Rock:
Iron Hill Waste Rock:
California Gulch Waste Rock:
Fluvial Tailing Site 4:
Alternative 4 - Waste Rock Removal
Alternative 4 - Diversion Ditches, Consolidation and Cover
Alternative 4 - Diversion Ditches and Road Relocation
Alternative 3 - Regrade and Cover
Alternative 2 - Stream Channel Reconstruction
Alternative 5 - Channel Reconstruction, Revegetation,
Sediment Dams, Wetlands and Selected Surface Material
Removal
A portion of the public meeting held on January 29, 1998 was dedicated to accepting formal oral
comments from the public.
Record of Decision
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RS-2
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3.0 COMMENTS AT THE FORMAL PUBLIC MEETING
The following are comments received at the formal public meeting. The comment is italicized
and EPA's response is in regular type.
Comment No. 1:
Response:
Comment No. 2:
Response:
Comment No 3:
Response:
Comment No. 4:
Response:
Comment No. 5:
Response:
Comment No. 6:
Response:
What are fluvial tailings?
These are mine waste materials that have been moved and reworked. They
have been deposited along streams and drainage channels by the
movement of water. Fluvial tailings are more expensive to cleanup due to
the location and quantity.
Will work near the AY-Minnie have an effect on the Mineral Belt Bicycle
Trail?
No, any water diversion work will not effect the bike trail. The possibility
of incorporating the water diversion into the grading work for the bike trail
will be evaluated. Water diverted from above the AY-Minnie will help
recharge the wetlands.
Where will fluvial tailings be deposited?
The fluvial tailings will be deposited either at the Colorado #2 site (UCG-
71) or used near the gulch during rcgrading of the area.
How will air quality be addressed during remedial action?
A fugitive dust plan will be part of the construction work plan, and will
include items such as wetting of roads, air monitoring, and traffic
restrictions. Due to the downwind location of Operable Unit 4, the
Leadville community should not be affected by any fugitive dust
emissions.
How will the bidding process work?
Resurrection will contract the work to an environmental engineering firm.
Will there be any plugging of shafts?
The North Mike and the Mab may have to be plugged. This will be
evaluated during remedial design.
Comment No. 7: How will the maintenance of the sediment traps be performed?
Record of Decision
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32791 M32M-OI 3\OIM\NEWRODVRODOU4-2.WPD
RS-3
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Response:
Comment No. 8:
Response:
Comment No. 9:
Response:
This will be developed in the long-term monitoring plan. The sediment
loading into the sediment traps will be evaluated for future land use.
What is a simple cover?
The proposed plan indicates that a simple cover will consist of 18 inches
of low permeable earthen material.
How will long-term maintenance be considered?
The design will be done to minimize the amount of long-term maintenance
by reducing the erosion potential and increasing the stability of reworked
areas.
Comment No. JO: What is the WAMP?
Response:
It stands for Work Area Management Plan and is part of the consent
decree. It identifies the work areas for the parties and contains procedural
requirements about how the work will be performed.
Additional Comment: After the public meeting, concern was expressed about the road relocation
at the A-YMinnie.
Response:
The specifications for the road relocation will be addressed during design.
Interested parties will be able to offer input during the design process.
Record of Decision
Upper California Gulch OlM
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RS-4
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4.0 REMAINING CONCERNS
Remaining Concerns
Based on review of the oral comments received during the public meeting, there are no
outstanding issues associated with implementation of the proposed remedial action.
Record of Deenion
Upper California Gulch OU4
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-------
TABLE 1
SUBBASINS AND CONTAMINATED WASTE ROCK PILES OU4
Sub-Basin
Garibald-'
Whites Gulch
Nugget Gulch
AY-Minnie
Iron Hill
Fluvial Tailing Site 4 and South Area
Waste Rock Pile
UCG-121 (Garibaldi)
UCG-109A(McDermith)
UCG-92A (Printer Girl)
UCG-104(Agwalt)
UCG-71 (Colorado No. 2)
UCG-74 (Rubie)
UCG-76
UCG-77
UCG-79 (North Moyer)
UCG-80 (Moyer)
UCG-85 (North Mike)
UCG-81 (AY-Minnie)
UCG-12(Mab)
UCG-33A
UCG-65
UCG-75 (Minnie Pump Shalt)
UCG-82A
UCG-93
UCG-95
UCG-98 (Lower Printer Boy)
TOTAL
Surface Area (acres)
1.17
2.50
1.15
0.77
2.65
0.73
0.25
0.15
1.53
0.47
1.18
7.10
0.70
0.26
0.50
0.45
1.06
0.15
0.18
0.46
23.41 acres
Volume (cy)
27,900
59,700
6,700
11,500
17,490
8,315
2,498
246
29,612
4,411
11,000
157,300
5,500
6,258
7,000
6,000
25,540
769
1,174
1,345
390,258 cy
Source: TerraMatrix/SMI 1998
P:\J280
WRODVTBL-1. WPD 3/26/91
-------
TABLE2
GARIBALDI SUB-BASIN WASTE ROCK GEOCHEMICAL DATA1
ABA Analysis
Sulfur, SO4 (%)
Sulfur, Pyrite & Organ ic(%)
Sulfur, Total (%)
AGP(T/KT)
Neutralizing Potential (% CaCO3)
ANP (T/KT)
NNP (T/KT)
EPA Method 1312 Extracted
Leacbate Analysis
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
PH
Alkalinity
TDS
Chloride
Sulfate
Total Metals
Arsenic
Cadmium
Lead
Zinc
Garibaldi Mine
Site (UCG-121)
0.84
1.59
2.43
75.9
0.1
0
-75.9
Waste Rock Pile
UCG-116
0.43
0.32
0.68
21
0.1
<1
-21
Waste Rock Pile
UCG-109A
0.18
1.15
1.33
42
0.8
8
-32
Concentration (mg/1 unless noted)
0.0015
0.034
19.11
10.3
4.59
5.05
O.0002
1.78
2.58
6.24
2.9 s.u.
2
254
1
345
<0.001
0.016
93.4
0.07
<0.2
7.3
na
2.7
0.3
1.78
3.4 s.u.
<2
410
<1
270
0.022
0.007
19.7
3.25
<0.2
3.6
na
1.8
1.2
3.80
4.7 s.u.
3
170
<1
80
Concentration (mg/kg)
115
0.61
3,570
382
30
6.5
446
518
46
6.8
4.63
1,510
Notes: 1) Source: Draft Operable Units 4, 8, and JO Reconnaissance Report (TerraMatrix/SMI.
1995d).
AGP = Acid generation potential
ANP - Acid neutralization potential
NNP = Net neutralization potential
T/KT = Tons per 1,000 tons
mg/1 = milligrams per liter
mg/kg = milligrams per kilogram
s.u. = standard units
"<" indicates that the value is less than the instrument detection limit.
Source: TerraMatrix/SMI 1998
P:\32MM) I )\OU4\NEWROD\TBL-2.WPD 3/26/98
-------
TARI.F, T
ocillon
niBALDI SUB-BASIN
:G-tG
1995 Poak Flow
1996 Peak Flow
pro-removal action spring Row everago
post-removal action spring (low avorago
1995/1996 spring How avorago
% ol I99S Peak Flow at CG-1
ii/XtrJ 1993
SURFACE WATER COC LOADINGS (Ibs/day)
Flow(cf») TSS Sulfale Ai.dln As, lolil Cd, dl» Cd, lol>t Cu, din Cu, loltl Pb. din Pb. loUl Zn. din Zn. lot«l
-^ _ . . _ --..wwwIIITK^M^UD-DMdlM
CG-.1 1995 Peak Flow
1996 Peak Flow
spring (low average
1995/1996 spring How average
pro-removal action spring (low average
post-removal action spring How averaqo
'G-1E 1995 Poak Flow
1996 Poak Flow
spring (low average
1995/1996 spring (low average
•/. ol 1995 Peak Flow al CG-1
•/. ol 1996 Peak Flow at CG-1
V. ol spring How avorago al CG-1
V. ol 1995/1996 sprinq llov/ average al CG-t
;G-10 1995 Peak Flow
1996 Peak Flow
spring How evorago
1995/1996 spring How evorago
% ol 1995 Poak Flow al CG-1
%ol 1996 Peak Flow at CG-1
% ol spring (low avorago al CG-1
% ol 1995/1996 sprinq How avorago al CG-1
:G-1C 1995 Peak Flow
1996 Peak Flow
spring now avorago
1995/1996 spring flow average
V. ol 1995 Peak Flow al CG-t
% ol 1996 Peak Flow al CG 1
% ol spring How average at CG-1
•/. ol 1995/1996 spring (low average at CG-1
G-1 1996 Peak Flow
V. ol 1996 Poak Flow al CG-1
8.81
8.81
391
533
325
5.55
9.34
10.3
4.37
6.87
106.0
1 17
1 12
129
7.53
7.27
3.43
5.13
85.5
82.5
87.7
96.2
7.11
s is
j. i j
2.69
4.42
80.7
58.5
68.8
82.9
003
0.34
48949
37449
11712
21026
8254
22948
21866
26447
J1T7
^ JJ/
11303
AA 7
^ *. /
7f1 K
/ U.O
17 n
j / .\j
53.6
ijjr.fi
t f ^OO
1l7fi
-------
TAMLE3 (Continued)
Location
CG-1H
GM-1
GP-1
CG 11
CG-1F
CG-1J
SURFA
Sample 10 Flow (etil
% ol 1996 Peak Flow al CG-1
% ol pre-removal action spring (low average al CG-1
% ol post-removal action spring How average at CG-1
% ol 1995/1996 spring How average al CG-1
1995 Peak Flow
1996 Peak Flow
pre-removal action spring flow average
post -removal action spring How average
% ol 1995 Peak Flow at CG-IG
% ol 1 996 Poak Flow at CG-IG
V. ol pro-removal action spring How average at CG-IG
% ol post-removal action spring flow average al CG-K
1995 Peak Flow
1996 Peak Flow
pro-removal action spring Dow avorago
post-removal action spring How average
% of 1995 Poak Flow at CG-IG
% or 1996 Peak Flow at CG-IG
% ol pro-removal action spring How average at CG-IG
% ol post-removal action spring flow average al CG-K
1995 Peak Flow
1996 Peak Flow
1995/1996 spring How average
V. ol 1995 Peak Flow al CG-IG
% ol 1996 Poak Flow al CG-IG
14 ol 1995/1996 spring How average al CG-1G
1995 Peak Flow
1996 Peak Flow
% ol 1995 Peak Flow it CG-IG
% ol 1996 Peak Flow at CG-IG
1995 Peak Flow
1996 Peak Flow
% ol 1995 Peak Flow al CG-IG
14 ol 1996 Peak Flow at CG-IG
1995 Peak Flow
1996 Peak Flow
% ol 1995 Peak Flow at CQ-1O
% oM996 Peak Flow al CO-10
53.8
48.6
38.7
51.4
NM
4.23
0.04
1.54
NA
89.2
2.53
71.6
0.82
0.006
0.39
0.004
12.0
0.1
24.7
0.19
0.709 '
NM
0.39
10.4
NA
14.2
0.36
0.3
5.3
6.3
1.48
2.38
21.6
50.2
1.18
1.14
17.2
24.1
™ i ii • •
CE WAI
TSS
3.4
20.5
1.6
13.2
548
1.83
216
42.8
O.tt
59.3
61.9
0.16
23.8
0.14
0.67
0.013
1.40
0.039
19.1
10.5
0.2 1
0.38
23.3
8.09
0.25
0.63
894
64.2
9.C8
5.02
904
86
9.78
6.73
i i
fERCC
Sullale
372
35.1
25.1
286
2054
263
748
446
12.0
35.6
3937
64.7
2090
33.2
41.0
1.41
95.4
1.59
229
126
2.39
4.46
38.8
48.5
0.40
1.05
79.8
128
0.83
2.79
127
123
1.33
2.67
••••••i „
>C LOAI
A». dl»i
646
138
186
220
0.30
0.12
0.058
96.7
289
104
1.06
0.015
0.70
0.008
287.30
4.96
1700
11.18
0.004
0.002
1.04
2.77
0.002
0.002
0.53
0.53
0.008
0.013
2.16
4.18
0.006
0.006
1.72
2.00
3INGS (Ibs/day)
Ai. total Cd.dlta Cd.iout
10.7 19.6 17.9
252 21.9 17.0
2.38 14.4 113
15.1 16.8 12.3
0.39 0.4 1
0.10 0.084
0.091 0.13
632 402
33.7 12.8
77.2 25.6
1.06 1.77
0.016 0.012
O.C1 0.74
0.007 0.007
32.3 68.4
2.58 1.15
203 112
5.56 1.26
• 0.004 0.11
0.002 0.041
0.12 4.44
0.40 5.29
0.002 0.058
0.002 0.003
0.059 2.25
0.28 0.33
0.008
0.013
0.24
2.09
0.013
0.008
0.39
1.00
0.240
0.006
9.26
0.63
0.191
0.012
7.38
1.14
WHtTtS GULCH SUB-BASIN
WG-1
1995 Peak Flow
1.63
9408
4132
0.009
0.18
0.097
0.43
0.095
0.13
42.4
14.8
26.4
1.68
0.016
0.83
0.008
56.9
1.60
127
1.63
^ K^MIH
0.046
0.022
1.55
2.85
0.006
0.005
0.20
0.47
0.016
0.039
0.54
3.77
0.102
0.018
3.45
:.eo
0.16
— "—^-^^
Cu. dlaa
31.1
45.1
18.2
24.4
3.99
0.75
1.27
35.5
11.9
24.2
11.5
0.13
5.77
0.071
43.2
1.16
90.8
1.35
I"— —»-••
0.17
0.056
0.65
0 75
0.002
0.010
0.007
0068
0.008
0.013
0.03
0 11
0.025
0.025
0.10
022
14.1
•••W^HMiM
Cu. total
22.1
339
14.2
20.8
4.08
0.71
1.28
41.0
11.1
25.0
10.8
0.14
5.71
0.071
35.9
1.42
88.5
1 39
0.21
0.068
0.72
f| fie
0.012
0.018
0.039
018
0.048
0.013
0.16
011
0.11
0.043
0.39
043
^^^B^^^^^W
18.5
WiBMIMillMW
Pb.dlaa
0.76
3.90
0.45
2.55
0.18
0.004
0.066
51.0
0.84
42.6
0.15
0.000
0.054
0.000
28.2
0.099
11.3
ft ftIM
0.038
0.012
6.47
.01
0.002
0.003
0.33
nan
0.008
0.013
1.35
0.01
0.008
1.08
1 79
0.009
jb.ioirt
0.46
3.60
0.10
_1.68
0.27
0.004
0.10
17.3
0.14
_23.9
0.44
0.001
0.091
0.000
3.99
0.04
2.98
0.072
0.046
0.015
0.41
0.31
0.035
0.037
0.32
0.40
0.064
3.60
4.05
0.32
0.088
2.87
••••V^^^^VM
4.13
^n. dlai
29.6
24.1
18.7
21.1
72.3
13.8
23.5
39.0
12.5
25.8
216
2.22
107
1.23
42.3
1.19
96.6
1.35
—»-»-»•••
4.74
2.41
0.93
1.77
•••^^-MW^^
0.31
O.S5
0.061
0.30
0.18
0.13
0.03
0.07
^^— ••—» i •,
2.10
1.68
0.41
0.69
— ^MH^^M^MW
13.1
Zn.tola
24.1
235
14.6
19.8
77.6
13.5
23.8
40.0
11.8
27.2
222
2.35
110
1.24
42.0
1.21
94.8
^1.42
4.78
2.37
0.90
1.64
HMMOW^M
0.47
0.45
0.088
0.23
0.72
039
0.14
0.20
2.93
1.91
O.SS
0.98
•••H^^^M^K
14.9
Sovrrt: Trm\toirit/SMI 199)
-------
TAm,F, 3 (Continued)
Location
1996 Peak Flow
spring flow average
base How average
1995/1996 spring How average
V. o( 1995 Peak Flow at CG-1
V. of 1996 Peak Flow alCG-1
•/.of spring flow average al CG-1 •
% ol 1995/1996 spring How average at CG-1
SPR-16A 1995 Peak Flow
1996 Peak Flow
spring Row average
base How average
1995/1996 spring How average
% of 1995 Peak Flow at WG-1
•/. ol 1996 Peak Flow al WG-1
% ol spring How average al WG-1
% ol bo jo How average it WG-1
V. ol 1995/1996 spring How average »l WG-1
SPFM6B 1995 Peak Flow
1996 Peak Flow
spring (low averago
base (low average
1995/1996 spring How ivorago
% oil 995 Peak Flow al WG-1
•/. ol 1996 Peak Flow il WG-1
% ol spring (low avorago al WG-1
% ol base (low average al WG-1
% ol 1995/1996 spring How average al WG-1
WG-3 1995 Peak Flow
1996 Peak Flow
spring (low average
base flow averago
1995/1996 spring How average
V. ol 1995 Peak Flow al WG-1
•/. ol 1996 Peak Flow al WG-1
V. ol spring Row average al WG-1
'A ol base How avorago al WG-1
V. ol 1995/1996 spring How average al WG-1
AG-1A 1995 Peak Flow
1996 Peak Flow
spring flow avorago
baso How averago
1995/1996 spring How average
% ol 1995 Peak Flow al WG-1
VmiUmr>V0 IMS
SURFACE WATER COC LOADINGS (Ibs/day,
0.32
0.27
0.29
0.081
0.29
0.003
0.21
0.029
0.63
0.017
0.001
0.001
0.001
0.0000
0.001
8.59
0.58
4.00
0.001
0.0000
0.0005
0.0001
0.0005
0.023
0.000
0.08
0.093
0077
0.093
0.021
0.093
0.7!
0.43
1.S9
0.097
0.085
0.092
0.020
0.092
0.65
0.47
1.52
0.003 0.003
0.0003 0.0003
0.002 0.002
0.0001
0.002
0.0002
0.002
0.070
1.33
1.38
0.93
0.020
0.93
81.6
57.5
112
58.8
86.9
0.54
0.06
0.3
0.010
03
33.1
4663
670
1246
1.73
1246
49.6
sta
125
17.8
72.8
146
1.62
8.09
069
6.09
0.15
4161
2308
1839
21.6
1839
101
59.4
145
42.0
101
1893
100
777
11.2
777
45.8
0.014
0007
0.007
0.0001
0.007
163
5.75
105
7.84
104
0.012
0001
0.005
0000
0.005
133
-------
I AHLK3 (Continued)
Location
AC-IB
AP-1
AG-2E
AG-2N
Sample ID
% ol 1996 Peak Flow at WG-1
*X ol spring How average at WG-1
*/• ol base How average at WG-1
% ol 1995/1996 spring How average al WG-1
1995 Peak Row
1 996 Peak Flow
spring flow average
base How average
1995/1996 spring How average
% ol 1995 Peak Flow al WQ-I
V. ot 1996 Peak Flow at WG-1
% ol spring How average at WG-1
% ol base How average el WG-1
% ol 1995/1996 spring How average al WG-t
base How avorago
% ol baio (low average at WG-1
1995 Peak Flow
1996 Peak Flow
1995/1996 spring How average
% ol 1995 Peak Flow al WG-1
% ol 1996 Peak Flow at WG-t
•/. ol 1995/1996 spring How average al WG-1
1995 Peak Flow
1996 Peak Flow
1995/1996 spring How avorago
% ol 1995 Peak Flow al WG-1
% ol 1996 Peak Flow al WG-1
V. ol 1995/1996 spring How average al WG-1
SURFACE WATER COC LOADINGS (Ibs/day)
Flow (els) TSS Sullala As.dln A, im.i r* -i.. M
2.5
36.1
29.4
28.0
0.05
0.06
0.05
0.034
0.05
3.07
2.50
6.02
100
4.67
0.015
44
0.33
0.08
0.16
20.2
3.33
15.0
0.31
0.26
0.18
19.0
10.8
15.0
1.2S
0.81
7.1
0.47
1.35
1.62
1.35
0.92
1.35
0.014
1.2S
0.14
9.4
0.079
0.40
4.16
8.90
2.16
4.32
0.095
1.67
0.25
6.36
7.01
4.32
0.09
5.42
0.25
2.58
61.3
219
42.8
181
139
148
37.7
148
4.37
3.58
11.7
73.4
8.17
12.14
236
60S
112
259
14.6
2.89
14.3
16.7
26.0
12.9
0.40
0.72
0.71
O.SO
76.5
29.8
75.7
0.003
0.001
0.002
0.0006
0.002
30.67
1.00
29.8
40.0
29.4
0.000
s.ee
0.002
0.000
0.001
20.2
0.33
13.5
0.002
0.001
0.001
19.0
1.08
13.5
0.25
8.45
46.0
5.49
0.003
0.001
0.002
0.002
0.002
1.53
0.75
6.1
164
3.96
0.000
8.02
0.002
0.000
0.001
1.01
0.33
2.0
0.002
0.001
0.00 1
0.95
1.08
1.95
i
1.25
25.3
9.9
23.3
0.002
0.004
0.003
0.001
0.003
2.23
1.50
4.43
32.1
4.08
0.001
16.8
0.089
0.010
0.032
92.0
3.83
47.7
0.010
0.001
0.003
10.4
0.27
4.25
1.15
30.0
5.2
25.4
0.005
0.004
0.004
0.001
0.004
3.07
1.15
5.58
13.0
4.73
0.001
9.45
0.059
0.009
0.024
37.1
3.06
28.7
0.005
0.004
0.003
3.17
1.35
3.13
NUGGET GULCH/AY-MINNIE SUB-BASIN
NG-1
1995 Nugget Gulch Peak Flow
1 995 Peak Flow
1996 Nugget Gulch Peak Flow
1996 Peak Flow
spring How average
1995/1996 spring (low average
% ol 1995 Nugget Gulch Peak Flow at CG-1
•A ot 1995 Peak Flow al CG-1
•X ot 1996 Nugget Gulch Peak Flow al CG-1
% ol 1996 Peak Flow al CG-1
% ol spring How avorage al CG-1
'/• ol 1995/1996 spring How average al CG-1
1.1
0.21
0.71
0.45
0.31
0.42
16.5
2.38
16.2
11.5
7.93
7.88
5115
165
3095
12.1
449
836
7.39
0.34
6.25
0.038
3.83
3.97
8663
1450
4136
2209
1991
3345
42.9
8.03
47.4
17.9
28.3
33.8
0.18
0.003
0.057
0.005
0.013
0.022
247.0
3.58
244
10.2
40.4
62.4
1.25
0.03
0.21
0.005
0.092
0.15
864.5
0.31
1.82
0.084
4.56
4.40
4.15
0.40
1.51
0.92
0.64
1.09
36.4
9.27
31.9
17.6
193
23.7
4.15
0.57
1.63
0.94
0.66
1.14
37.2
5.42
22.5
16.5
15.8
18.0
CtTrflit
2.30
53.8
9.0
44 t
0.40
034
0.34
0.089
0.34
2.88
1.61
5.32
29.1
4.40
0.021
689
8.19
1.72
3.70
58.2
8.14
47.4
0.042
0.029
0.020
0.30
0.14
0.25
48.1
9.06
34.7
12.4
148
24.5
58.0
18.2
78.3
34.3
82.9
80.7
MMraMraHBB^HM
r>(. |n«*t
2.40
44.7
5.5
0.49
0.32
0.38
0.035
0.36
2.63
1.54
5.47
12.4
4 43
0.019
8 99
9.08
1.91
4.11
49.2
9.17
48.4
0.047
0.036
0.023
0.25
0.17
0.27
48.3
10.8
31.6
12.2
14.6
24.1
42.8
13.2
51.2
27.0
81.7
61.6
-^^— •••
rO, 0111
0.25
10.6
7.1
7.65
0.0003
0.0003
0.0003
0.0002
0.0003
3.07
0.25
1.78
10.0
1 57
0.0001
A J1
0.005
0.001
0.003
60.7
1.00
122
0.002
0.004
0.002
19.02
3.25
8 16
0.63
0.14
0.69
0.18
0.30
0.29
1.6
041
1.17
0.34
1.71
1.02
«^— — •
Pb. lolal
0.19
0.26
8.6
0.16
0.0003
0.002
0.001
0.0002
0.001
0.01
1.35
0.18
9.09
^V^MMBMHBV
0.0001
0.002
0.001
0.002
0.043
0.77
0 17
0.002
0020
0.008
0.04
11.67
063
1.51
0.45
3.68
0.31
0.93
1.15
0.9
0.07
0.34
0.090
0.59
0.40
ai^aaMMMi^M
Zn. dlti
1.50
36.3
12.7
31.1
0.88
0.57
0.68
0.11
0.68
6.75
3.21
11.6
43.4
¥.97
^•«^— «"^«i««
0.045
17.6
263
0.51
1.15
20.1
2.90
0.050
0042
0.026
0.38
0.24
038
605
67
215
136
91.7
155
42.7
7.09
33.1
21.7
18.6
24.1
^^^^^••••MB-
Zn. lolal
1.67
30.9
11.7
26.1
0.84
0.63
0.68
0.11
0.68
S.63
3.49
11.3
43.1
9.53
0.048
16.6
2.63
0.58
1.22
17.6
3.21
17.0
0.067
0.042
0.030
0.45
0.23
n J9
0.4Z
574
72
208
134
91.6
156
30.9
6.56
24.1
18.7
188
TirmWo/rit/SM7 I99S
-------
TAFJLF3 (Confirmed)
location
NG-?
SURFACE WATER COC LOAD.NGS (Ibs/day)
1995 Peak Flow
1 996 Peak Flow
spring flow average
1995/1996 spring How average
•/. of 1995 Peak Flow at NG-1
% of 1996 Peak Flow al NG-I
% ol spring flow average al NG-1
•/. of 1995/1996 spring flow average al NG-1
MM- 1 1995 Peak Flow
1 996 Peak Flow
spring now average
1995/1996 spring flow average
•I. of 1995 Peak Flow al NG-1
V. of 1996 Peak Flow al NG-t
% of spring flow average al NG-t
% of 1995/1996 spring flow average al NO- 1
NM 2 1995 Peak Flow
1996 Peak Flov
1995/1996 spring How average
% of 1995 Peak Flow al NG-1
% of 1996 Peak Flow at NG-1
% ol 1995/1996 spring (low average al NQ-1
NG-4A 1995 loading
%ol NG-1 on June I. 1995
NG-4B 1995 loading
•/.of NG-1 on June I. 1996
NG-3
199$ Peak Flow
1996 Peak Flow
1995/1996 spring flow average
% ol 1995 Peak Flow af NG-1
V. oM996 Peak Flow al NG-t
y. ol 1995/1996 spring flow average al NG-1
NG-S
IHW-1
1995 Peak Flow
1996 Peak Flow
spring flow average
"HW-2 1996 load
_% ol 1996 load measured al IHW-1
0.14
0.15
02
61.0
31.1
46.4
47.6
0.031
J.58
0.034
8.29
0.004
0.89
0.186
26.2
107
282
499
242
684
62.8
59.7
61.9
5.75
755
1145
1244
too
34.2
57.5
37.2
2015
386
447
726
139
17.5
22.5
21.7
——•—••.
22.1
43.7
1.53
1.31
".WO
0.003
0.015
0.015
162
622
117
__. 71.8
0.010
0.001
0.002
0.003
286
18.8
13.1
__ 1?.6
0.002
0.003
65.1
13.5
0.10
oott
0.046
0.070
294
217.8
49.6
_. 46.2
0.007
0.001
0.001
0.002
20.0
14.4
1.3
^1.33
0.002
0.003
6.51
1.92
0.39
0.20
0.30
0.35
97
21.6
46.7
_ 32.5
1.00
0.14
0.19
0.32
251
15.1
30.4
28.9
0.001
0.001
0.28
0 11
3.67
027
1.06
1.71
648
28.9
160
_ 151
15.6
0.14
2.08
3.38
2766
14.9
315.3
297
0.018
0.013
3.12
11.0
6.71
8.35
9.09
121
54.1
56.3
_ 37.2
14.1
2.88
3.24
525
155
23.2
21.8
_2I.5
0.011
0.020
0.12
11.74
7.48
8.72
9.75
110
61.3
59.8
_ 40.5
14.81
2.79
3.29
5.35
139
22.9
22.6
_22.2
0.027
0.036
0.2S
0.11
0.079
0.087
0.13
73.3
50.3
28.9
45.8
0.003
0.003
0011
0.018
2.19
1.8
3.8
6.35
0.004
0.008
3.07
1.02
0.41
0.55
0.95
225
131
59.6
_B2.9_
0.003
0.005
0.024
0.039
0.59
1.7
2.6
_3.4Q
0.040
0.052
8.79
53.1
31.0
44.4
50.9
78.8
22.8
48.4
^32.8
102
21.3
23.3
37.8
152
15.7
25.4
^24.3
0.006
0.12
0.098
56.1
34.7
46.4
537
78.4
25.B
50.7
_ 34.5^
108
18.8
22.7
38.B
148
14.0
24.8
— 23.7_
0.15
0.19
0.22
0.008
192^
0.068
1697
909
0007
J4.3
0.062
127
_a075o.12
0.004
_74.7
0.001
0.004
_g.Q09^
0.001
26.2
0.004
BO.Q
0.001
0.004
0.1B
0:002
52.5
0.001
0.0004
0.001
0.21
0.047
0.10
0.049
5.39
0.065
0.15
0.47^
0.050
32.B
0.010
0.004
0.013
0.11
0.030
_0.051
0.027
0.009
0.025
0.28
0.077
^0.11
0.050
32.8
0.018
10.1
O.OSS
45.1
fount:
-------
TABLE 3 (Continued)
locillon
SURFACE WATER COC LOADINGS (Ibs/day)
Jto* Celt) JTSS SuHile At, din At. total Cd. dlu Cd. toll!
dl«> Zn. toltl
IHW-3 1996
V. ol 1996 load measured al IHW-1
Savirr Ttrn\ hirit/S\ 0 1993
-------
TABLE 4
GEOCHEMICAL DATA FOR WASTE ROCK SOURCES IN WHITES GULCH1
ABA Analysis
Sulfur, SO, (%)
Sulfur, Pyrite & Organic (%)
Sulfur, Total (%)
AGP (T/KT)
Neutralizing Potential (%CaCO,)
ANP (T/KT)
NNP(T/KT)
Sample Site
UCG-1041
0.63
1.06
1.69
52.8
<0.1
0
-52.8
Sample Site
UCG-92ANC'
0.22
0.28
0.5
15.6
<0.1
0
-15.6
Sample Site
UCG92-ASC1
0.42
0.57
0.99
30.9
<0.1
0
-30.9
EPA Method 1312 Extracted Leachate Analysis (mg/1 unless noted)
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
pH (units)
Alkalinity (mg/1 as CaCOj)
TDS
Chloride
Sulfate
O.001
0.003
14.3
0.739
0.02
3.69
<0.0002
1.64
225
0.411
32 s.u.
<2
124
<1
148
<0.001
0.003
6.6
0.066
<0.02
1.88
<0.0002
1.85
2.02
0.571
3.8 s.u.
<2
56
<1
66
<0.001
<0.003
0.8
2.53
1.59
0.48
O.0002
2.08
2.2
0.325
3.2 s.u.
2
62
<1
102
Total Metals (mg/kg)
Arsenic
Cadmium
Lead
Zinc
41.9
0.36
138
252
20.9
0.32
174
72.9
12.8
0.33
701
34.6
Notes: 1 . Source: Draft-Operable Units 4, 8, and 10 Reconnaissance Report (TerraMatrix/SMl. I995d).
2. This waste rock pile is also referred to as the Agwalt waste rock pile.
3. This waste rock pile is also referred to as the Printer Girl waste rock pile.
AGP - Acid generation potential
ANP - Acid neutraliraiton potential
NNP » Net neutralization potential
T/KT » Tons per 1 ,000 tons
mg/1 - milligrams per liter
mg/kg - milligrams per kilogram
s.u. = standard units
"<" indicates that the reported value is less than the instrument detection limit (IDL).
Source: TerraMatrix/SMl 1998
P:\3280-OIJ\OU4\NEWROD\TBM.WPD J/26/98
-------
TABLES
GEOCHEMICAL DATA FOR WASTE ROCK IN THE
NUGGET GULCH AND AY-MINNIE SUB-BASINS
ABA Analysis
Sulfiir, SO4 (%)
Sulfur, Pyrite & Organic(%)
Sulfur, Total (%)
AGP (T/KT)
Nuet. Potential (% CaCO3)
ANP(T/KT)
MNP (T/KT)
UCG-79
(North
Moyer)
2.27
3.63
5.9
184.4
13.5
135
-49.4
UCG-80
(Moyer)
0.86
1.15
2.01
62.8
5.5
55
-7.8
UCG-85
(North Mike)
1.79
3.58
5.37
167.8
0.1
0
-167.8
UCG-81
(AY-Minnie)
1.04
1.06
2.1
65.6
13.2
132
66.4
EPA Method 1312 Extracted Leachate Analyses (mg/1 unless noted otherwise)
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
PH
Alkalinity
TDS
Chloride
Sulfate
<0.001
0.062
460
0.02
0.02
30
<0.0002
0.34
1.59
1.92
6.2 s.u.
40
2110
<1
1320
O.001
0.009
117
0.017
<0.02
15.3
<0.0002
0.477
1.49
0.123
6.3 s.u.
35
564
<1
352
0.002
0.081
167
16.2
1.04
7.77
<0.0002
1.28
2.71
10.8
2.7 s.u.
<2
1050
1
100
<0.001
0.395
214
0.012
0.082
37.8
<0.0002
0.99
1.78
25.3
5.7 s.u.
15
1210
1
843
Total Metals (rag/kg)
Arsenic
Cadmium
Lead
Zinc
304
253
4,460
28,100
145
47
2,940
8,160
227
3
2,090
783
212
113
11.4
18,000
Notes: 1) Source: Draft Operable Units 4, 8, and 10 Reconnaissance Report (TerraMatrix/SMI,
1995d).
AGP = Acid generation potential
ANP = Acid neutralization potential
NNP = Net neutralization potential
T/KT = Tons per 1,000 tons
mg/l = milligram per liter
mg/kg = milligram per kilogram
s.u. = standard units
"<" = indicates that the value is less than the instrument detection limit.
Source: TerraMatrix/SMI 1998
PA32SO-013\OU4\NEWROD\TBL-5.WPD3/26/98
-------
TABLE 6
WASTE ROCK PILE UCG-12 GEOCHEMICAL DATA1
ABA Analysis ||
Sulfur, SO, (%)
Sulfur, Pyrite & Organic(%)
Sulfur, Total (%)
AGP (T/KT)
Neut. Potential (% CaCO,)
ANP (T/KT)
NNP(T/KT)
3.09
2.04
5.13
160.3
4.4
44
-116.3
EPA Method 1312 Extracted Leacbate Analyses (mg/l unless noted)
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
pH (units)
Alkalinity (mg/l as CaCO3)
TDS
Chloride
Sulfate
<0.001
0.137
518
0.084
0.119
43.3
<0.0002
0.54
1.92
5.21
6.9 s.u.
30
2520
<1
1710
Total Metals (rag/kg)
Arsenic
Cadmium
Lead
Zinc
290
131
36,100
19,300
Notes: 1) Source: Draft-Operable Units 4. 8. and JO Reconnaissance Report (TerraMatrix/SMI
1995d).
AGP « Acid generation potential
ANP » Acid neutralization potential
NNP - Net neutralization potential
T/KT « Tons per 1,000 tons
mg/l = milligram per liter
mg/kg - milligram per kilogram
s.u. = standard units
"<" = indicates the value is less than the instrument detection limit. |
Source: TerraMatrix/SMI 1998
P:\32SO-OI3\OU4\NEWRODVTBl-6 WPD 3/2&9S
-------
TABLE 7
FLUVIAL TAILING SITE 4 - FLUVIAL TAILING GEOCHEMISTRY DATA
Sample
Location'
Depth Interval
Sample Type
Total Metals Analysis' I EPA Method 1312 Leachate Analysis'
Arsenic
Cadmium
Copper
Lead
Zinc
Arsenic
Cadmium
Lead
Zinc
Tilling Rl Geochemieil Simples'
Composite'
F4BI
F4BI
F4B2
F4B2
F4B3
F4B3
F4B4
F4B4
F4B5
F4B5
0-0.15'
0-2'
10-12.7
0-2'
8-I01
0-2'
8 - 8.8'
0-2'
10 -ll.r
0-2'
2-4'
STC*
T'
FS1
FS
FS
T
FS
T
FS
T
FS
248
65
-8.6
347
5.9
347
6
232
3.5
NM
311
516
-32
24.4
131
-0.56
114
166
98
54.3
NM
501
271
87.9
339
NR
NR
NR
NR
NR
NR
NM
NR
13200
181
R
17200
99.5
18900
1130
14100
147
NM
30100
11300
209
9060
2360
190
2140
7170
18900
5800
NM
54900
NM
-0.01
-0.01
-0.001
-0.01
-0.01
-0.01
-0.01
-0.01
-0.01
-0.01
NM
0.0159
0.870
0.0789
-0.005
0.0971
-0.005
0.0304
-0.005
0.492
0.919
NM
-0.003
0.0191
9.85
-0.001
11.4
-0.001
12.7
-0.003
8.31
4.90
NM
2.08
18.6
8.88
0.125
6.35
-0.02
4.02
0.101
4.98
14.1
Terrestrial Ecosystem Risk Assessment Geochemicil Simples*
UCG65E
UCG65F
UCG65H
UCG65I
0 - 0.5'
0 - 0.5'
0 - 0.5'
0 - 0.5'
STC
STC
STC
STC
232
423
226
487
24
86
17
24
138
108
197
367
9862
14551
7574
39608
5646
16287
3743
5499
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Notes: 1 ) Tola! metals analysis results are in mg/1.
2) EPA Method 1312 analysis results are in mg/kg.
3) Sample locations are shown on Figure 2.7, Fluvial Tailing Site 4 Geochemical Sample Locations.
4) Source: Tailing Disposal Area Rl (WCC. I994a).
5) Composite sample: 10 surface samples (0 - 2 inches) were collected and composited as a single sample as described in the Tailing Rl (WCC, I994a).
6) STC - Surface tailing composite sample.
7) T - Subsurface sample, collected at a depth of 0 - 2 feet.
8) FS - Foundation soil sample, sample was collected from foundation soil below the fluvial tailing and intermixed fluvial tailing/fluvial sediment material.
9) Source: Screening-Level Ecological Risk Assessment, Operable Unit No. 4. California Gulch Superfund Site (Sloller, 1996).
"-" - indicates that the reported value is below the instrument detection limit.
NM - Not measured.
Source: TerraMatrix/SMI 1998
P:UJSO-OI3\OU4\NEWRODVrBL-7.WPD 3/76/91
-------
TABLES
GEOCHEMICAL DATA FOR WASTE ROCK SOURCES SAMPLED IN
FLUVIAL SITE 4 AND SOUTH AREA1
ABA Analysis
Sulfur, SO4 (%)
Sulfur, Pyrite &. Organic(%)
Sulfur, Total (%)
AGPCT/KT)
Neut Potential (% CaCO,)
AN(T/KT)
NNPfT/KT)
Sample Site UCG-65
0.63
OJ
033
19.7
33.9
339
319.3
Sample Site UCG-75
3.01
1.54
1.47
94.1
11.4
114
19.9
Sample Site UCG-98
0.74
0.06
0.68
23.1
0.69
639
17.1
EPA Method 1312 Extracted Leachate Analyses (mg/1 unless noted)
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
pH (units)
Alkalinity (mg/l as CaCO,)
IDS
Chloride
Sulfate
<0.001
0.013
40.8
<0.01
O.02
8.87
<0.0002
1.52
0.492
O.OS8
7.4 s.u.
30
200
<1
119
Total Metals (rag/kg)
Arsenic
Cadmium
Lead
Zinc
264
121
15,100
29,500
<0.001
0.342
249
0.014
0.124
322
<0.0002
0.772
1.872
29.88
5.8 s.u.
25
1330
<1
878
924
96.6
20,800
16.700
<0.001
<0.003
1.9
321
<0.02
0.542
0.0002
0.866
1.932
0.039
5.9 s.u.
5
18
<1
6
282
2.9
972
777
Notes: 1) Source: Draft-Operable Units 4. 8. and 10 Reconnaissance Report (TerraMatrix/SMI. I995d).
AGP = Acid generalization potential
ANP » Acid neutralization potential
NNP - Net neutralization potential
T/KT = Tons per 1,000 tons
mg/l
mg/kg
s.u.
milligram per liter
milligram per kilogram
standard units
indicates the value is less than the instrument detection limit.
Source: TerraMatrix/SMI 1998
P:\32I04I3\OU4\NEWROD\TBL-8.WPD 1/26AS
-------
TABLE 9
CULTURAL RESOURCES
(Page 1 of 2)
Number
Abbreviated Description/name
Eligible/
Contributing
Potential Adverse
Effect & expected year
of impact
5LK.805
5LK.846
51X851
5UC862
5LK.919
5LK.381
5LK.383
5LK.708
5LK.1204
5LK.1205
5LK.1206
5LK.1207
5LK.1208
5LK.I209
5LK.1210
5LK.121I
5LK.1212
5LK.1213
5LK.1214
5LK.12I5
5LK.1216
5LK.12I7
5LK.12I8
5LK.12I9
5LK.1220
no/no
yes/yes
yes/yes
no/yes
no/no
yes/yes
no/yes
yes/yes
no/yes
no/yes
no/yes
no/yes
no/yes
ves/ves
yes/yes
yesfyes
no/yes
no/yes
yes/yes
no/yes
no/yes
yes/yes
yes/yes
no/yes
no/yes
no
no
no
yes (98)
no
no
yes (99)
no
yes (98)
yes (98)
yes (98)
yes (98)
yes (98)
no
no
no
no
no
no
no
no
no
no
no
no
P:\3280-0 l3'OU4\NEWRODYIbW.W|'U
-------
TABLE 9
CULTURAL RESOURCES
(Page 2 of 2)
5LKJ221
5LK.1222
5LK.1223
SLK.834
5LK.1243
5LK.1246
5LK.1224
5LK.1225
5LK.1226
5LK.1227
5LK.1228
5LK.1229
5LK.1230
5LK.1231
5LK.1232
5LK.1233
no/yes
no/yes
no/yes
no/yes
no/yes
yes/yes
no/yes
no/yes
no/yes
no/yes
no/yes
no/yes
no/yes
no/yes
no/yes
no/yes
no
no
no
no
no
no
yes (99)
yes (99)
yes (99)
yes (99)
yes (99)
yes (99)
yes (99)
yes (99)
yes (99)
yes (99)
P:\32S(M)I3\OU4VNEWROD\TBL.9.WPD
-------
TABLE 10
COMPARISON OF ALTERNATIVES FOR THE
GARIBALDI SUB-BASIN WASTE ROCK - NCP CRITERIA
Overall Protection ofHuman
Health and the Environment
Compliance with ARARs
Long-Term Effectiveness and
Permanence
Reduction of Toxicity, Mobility,
or Volume through Treatment
Short-Term Effectiveness
mplementability
Cost1
Alternative 1
No Action
Does not meet RAOs.
Not an issue.
No change in long-term
effectiveness.
Would not reduce the toxicity.
mobility, or volume of waste rock
and does not include treatment.
^o disturbance to the community.
Not effective in reducing short-
term risk.
«Jot an issue.
SO
Alternative 2
Diversion of Surface Water and
Stream Channel Reconstruction
Involves diversion of surface and
portal flows minimizing leaching
and erosionaf releases associated
with these flow components. Direct
precipitation would continue to
infiltrate and contribute to erosional
releases.
Complies with ARARs.
Effective in diverting, and stable
under, the 100-year, 24-hour event
Effective in diverting surface runon
around the waste rock, but does not
prevent direct precipitation from
infiltrating through the waste rock.
Overall volume of water contact
waste rock would be reduced, thus
reducing leaching and erosional
releases from the site.
Potential risks to the community
nclude dust emissions and increased
road traffic during mobilization and
demobilization.
Technologies are common and
widely accepted. Reliability of
design and implementation based on
established practice. Unusual
>ermits arc not anticipated.
SI30.5IO
Alternative 3
Diversion of Surface Water and
Selected Removal
Same as Alternative 2.
Complies with ARARs.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
SI38.4I3
Source: TerraMairix/SM! 1998
The No Action alternative will incur incidental co«s related to the 5-ycar review, monitoring and administrative issues.
fA3JSO-OI3\OU4WEWROO\TBL.IO.WPO ]/]«*!
-------
TABLE II
COMPARISON OF ALTERNATIVES FOR THE PRINTER GIRL WASTE ROCK - NCP CRITERIA
Overall Protection of
Human Health and the
Environment
Compliance with ARARs
Long-Term Effectiveness
ind Permanence
Reduction of Toxicity,
Mobility, or Volume
through Treatment
Short-Term Effectiveness
mplementibility
Cost1
Alternative I
No Action
Does not meet the
RAOs.
Not an issue.
No change in long-term
effectiveness.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
No disturbance to the
community. Not
effective in reducing
short-term risk to the
environment.
Mot an issue.
SO
Alternative 2
Stream Channel
Reconstruction
Reduces erosion and releases
to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Complies with all ARARs.
Minimizes leaching and
erosion associated with
stream flow but does not
prevent infiltration of
precipitation through the
waste rock.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the
shon-tcrm.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
$54.900
Alternative 3
Stream Channel
Reconstruction and
R ^griding
Similar to Alternative 2, except
regrading would help reduce
infiltration associated with
precipitation. Stability of pile
would increase.
Complies wiih all ARARs.
Similar to Alternative 2 except
infiltration would be reduced
and stability increased.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would be
used to reduce the short-term
risk to the community due to
dust emissions and exposure of
workers 10 contaminants.
Road traffic would increase
over the short-term.
Technologies are common and
widely accepted. Unusual
permits are not anticipated.
J55.400
Alternative 4
Waste Rock Removal
All RAOs would be
achieved. Provides highest
level of protection.
Complies with all ARARs
Reduces leaching and
erosional releases by
removing waste rock.
Reduces leaching and
erosional releases by
removing waste rock.
Similar to Alternatives 2 and
3, except greater impacts to
the community and workers
from increased traffic and
potential dust emissions
Engineering controls would
be implemented as in
Alternatives 2 and 3
Technologies arc common
and widely accepted.
Unusual permits are not
anticipated.
$99.300
Source: TerraMatrix/SMI 1998
'The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.
P.U2»0-OI)'.OIWNEWROD\TBL-I I.
-------
TABLE 12
COMPARISON OF ALTERNATIVES FOR THE
NUGGET GULCH WASTE ROCK - NCP CRITERIA
Overall Protection of
Human Health and the
Environment
Compliance with
ARARs
xtng-Term
Dffectrveneu and
'ermanence
led action of Toxicity,
Mobility, or Volume
through Treatment
Short-Term
Effectiveness
Implementability
r
Cost1
Alternative 1
No Action
Does not meet the RAOs.
Not an issue.
No change in long-term
effectiveness.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
No disturbance to the
community. Not effective
in reducing short-term risk
to the environment.
Mot an issue.
SO
Alternative 2
Diversion Ditches
Reduces erosion and
releases to surface water and
groundwater associated with
stream flow but not
precipitation. Docs not
address wind erosion.
Complies with all ARARs.
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the
waste rock.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the
snort-term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
S299.026
Alternative 3
Diversion Ditches and
Waste Rock Reerading
Similar to Alternative 2,
except regrading would help
reduce infiltration associated
with precipitation. Stability
of pile would increase.
Complies with all ARARs.
Similar to Alternative 2
except stability would be
increased.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the
short-term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
$369.702
Alternative 4
Diversion Ditches,
Consolidation, and Cover
Similar to Alternative 2.
except infiltration would be
greatly reduced and erosional
releases would be minimized.
Wind erosion would be
addressed through cover.
Complies with all ARARs
Similar to Alternative 2,
except erosional releases
would be minimized by
construction of simple cover
and revegetation.
Similar to Alternatives 2 and
3. except simple cover over
consolidated waste rock would
even further reduce leaching
and loading from the site.
Similar to Alternatives 2 and
3. except greater impacts to the
community and workers from
increased traffic and potential
dust emissions. Engineering
controls would be
implemented as in
Alternatives 2 and 3.
Technologies arc common and
widely accepted. Unusual
permits are not anticipated
$800.012
Source: TerraMatrix/SMl 1998
'The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.
IWJ:»0-OIJ\OU4\NEW11OD\TBL-I2.WPD 3/26/98
-------
TABLE 13
COMPARISON OF ALTERNATIVES FOR THE AY-MINNIE - NCP CRITERIA
Overall Protection of
Human Health and the
Environ meat
Compliance with
ARARs
.xmg-Term
HfTectiveness and
'ermanence
Reduction of Toxkity,
Mobility, or Volume
through Treatment
Short-Term
Effectiveness
mplementability
Cost1
Alternative 1
No Action
Does not meet the
RAOs.
Not an issue.
No change in long-term
effectiveness.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
No disturbance to the
community. Not
effective in reducing
short-term risk to the
environment
Not an issue.
SO
Alternative 2
Diversion Ditches
Reduces erosion and releases
to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Complies with all ARARs.
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the waste
rock.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the short-
term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
$169.081
Alternative J
Diversion Ditches and
Reeradine
Similar to Alternative 2,
except regrading would help
reduce infiltration associated
with precipitation. Stability of
pile would increase.
Complies with all ARARs.
Similar to Alternative 2 except
stability would be increased.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would be
used to reduce the short-term
risk to the community due to
dust emissions and exposure
of workers to contaminants.
Road traffic would increase
over the short-term.
Technologies are common and
widely accepted. Unusual
permits are not anticipated.
S184.I3I
Alternative 4
Diversion Ditches and
Road Reconstruction
Similar to Alternative 2,
except realignment of
County Road 2 adds further
protection to stability of
timber cribbing.
Complies with all ARARs.
Similar to Alternative 2,
except stability of timber
cribbing is addressed.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Similar to Alternatives 2 and
3, except greater impacts to
traffic and greater potential
for dust emission during
realignment of County Road
2. Engineering controls
would be implemented as in
Alternatives 2 and 3.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
$240.820
Source: TerraMatrix/SMl 1998
'The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.
PA32IO-01 J\OU4\NEWRODWBL-13 WPDJ/26/9J
-------
TABLE 14
COMPARISON OF ALTERNATIVES FOR THE
IRON HILL WASTE ROCK - NCP CRITERIA
Overall Protection or
Human Health and the
Environment
Compliance with
ARARs
^one-Term
£fliectiveness and
Permanence
led action of Toxicity,
Mobility, or Volume
through Treatment
Short-Term
Effectiveness
mplementabiliry
Cost1
Alternative 1
No Action
Does not meet the RAOs.
Not an issue.
No change in long-term
effectiveness.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment
Mo disturbance to the
community. Not effective
n reducing short-term risk
to the environment.
Not an issue.
SO
Alternative 2
Diversion Ditches
Reduces erosion and
releases to surface water and
groundwaier associated with
stream flow but not
precipitation. Does not
address wind erosion.
Complies with all ARARs.
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the
waste rock.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the
short-term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
SI 17.189
Alternative 3
Retrrtdinf and Cover
Regrading of one pile and
covering of the other pile
would help reduce
infiltration associated with
precipitation.
Complies with all ARARs.
Erosional releases and
infiltration would be
minimized by regrading and
construction of simple cover.
Surface area exposed to
water would be reduced,
thus reducing volume of
water contacting waste rock.
Mobility of contaminants
from the site would also be
reduced. Toxicity is
unchanged and treatment is
not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the
short-term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
SI 59.776
Alternative 4
Waste Rock Consolidation
Infiltration would be greatly
reduced and erosional releases
would be minimized. Wind
erosion would be addressed
through cover.
Complies with all ARARs.
Erosional releases and
infiltration would be further
minimized by consolidation
and construction of simple
cover.
Similar to Alternative 3,
except simple cover over
consolidated waste rock would
even further reduce leaching
and loading from the sue
Engineering controls would be
used to reduce the shon-tcrm
risk to the community due to
dust emissions and exposure o!
workers to contaminants
Road traffic would increase
over the short-term
Technologies are common and
widely accepted. Unusual
permits are not anticipated
$227.759
Source: TerraMatrix/SMI 1998
The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.
O28I3\OIM\NEWRODMBI_-H WPD3/26/9S
-------
TABLE 15
COMPARISON OF ALTERNATIVES FOR THE
CALIFORNIA GULCH WASTE ROCK - NCP CRITERIA
Overall Protection of
Human Health and the
Environment
Zompliance with
ARARs
^ong-Term
£flectiveneu and
'ermanence
Reduction of Toxicity,
Mobility, or Volume
through Treatment
Short-Term
^ffectiveness
impiementability
Cost1
Alternative I
No Action
Does not meet the RAOs.
Not an issue.
No change in long-term
effectiveness.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
No disturbance to the
community. Not effective
in reducing short-term risk
to the environment.
Mot an issue.
SO
Alternative 2
Channel Reconstruction
Reduces erosion and
releases to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Complies with aJI ARARs.
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the
waste rock.
Overall volume of water
contacting waste rock would
be reduced. Mobility of
contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers lo
contaminants. Road traffic
would increase over the
short-term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
S548.34I
Alternative 3
Selected Regrading
degrading would help
reduce infiltration associated
with precipitation. Does not
address run-on or wind
erosion.
Complies with all ARARs.
Erosional releases and
infiltration would be
minimized by regrading and
stability of piles would be
increased.
Surface exposed to water
would be reduced, thus
reducing volume. Mobility
of contaminants from the site
would also be reduced.
Toxicity is unchanged and
treatment is not included.
Engineering controls would
be used to reduce the short-
term risk to the community
due to dust emissions and
exposure of workers to
contaminants. Road traffic
would increase over the
short-term.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
$67.085
Alternative 4
Selected Waste Rock
Removal
All RAOs would be achieved
by removing source at those
locations selected for removal.
Provides highest level of
protection.
Complies with all ARARs
Reduces leaching and
erosional releases by removing
waste rock.
Reduces leaching and
erosional releases by removing
waste rock.
Similar to Alternatives 2 and
3, except greater impacts to (he
community and workers from
increased traffic and potential
dust emissions. Engineering
controls would be
implemented as in Alternatives
2 and 3.
Technologies are common and
widely accepted. Unusual
permits are not anticipated.
$425.731
Source: TerraMatru/SMI 1998
'The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.
PU2IO-OI)\OIUVNEWROIKTBL-I3 WPD 3/76/9!
-------
TABLE 16
COMPARISON OF ALTERNATIVES FOR FLUVIAL TAILING SITE 4 - NCP CRITERIA
}ve rill Protection of
llumin Health and the
Dnvironmenf
Compliance with
ARARs
Long-Term
Effectiveness find
'ermanenee
Reduction of Toxifity.
Mobility, or Volume
Ihrough Treatment
Short-Term
Effectiveness
Implemenlabilily
Allernilive 1
No Action
Does not meet the
RAOs
Mot an issue.
No change in long-
lerm effectiveness.
Would nol reduce the
toxiciiy. mobility, or
volume of wasle rock. .
Does nol include
trcalmcnl.
No disturbance to the
community. Nol
effective in reducing
short-term risk to the
environment.
Nol an issue.
Alternative 2
Channel Reconstruction and
Revegetation
Reduces erosion and releases to
surface water and groundwaier
associated with stream flow but
nol precipitation. Does not address
wind erosion.
Complies with all ARARs.
Minimizes leaching and erosion
associated with stream flow but
does not prevent precipitation from
infiltrating Ihrough (he waste rock.
Overall volume of water contacting
waste rock would be reduced.
Mobility of contaminants from the
site would also be reduced.
Toxiciiy is unchanged and
Ireatmcnt is not included.
Engineering controls would be
used to reduce the short-term risk
lo the community due lo dust
emissions and exposure of workers
to contaminants. Road traffic
would increase over the short-term.
Technologies are common and
widely accepted. Unusual permits
are not anticipated.
$2.393.933
Alternative 3
Channel Reconstruction,
Sediment D*ms and Wetlands
Reduces erosion and releases lo
surface water and groundwaler
associated with stream flow but
nol precipitation. Does nol
address wind erosion.
Complies, with all ARARs.
Similar to Alternative 2 except
sediment dams reduce release of
sediment downstream.
Overall volume of water
contacting waste rock would nol
be reduced but mobility of
contaminants from (he site
would be reduced. Toxiciiy is
unchanged and treatment is nol
included.
Engineering controls would be
used to reduce the short-term
risk to the community due to
dust emissions and exposure of
workers lo contaminants. Road
traffic would increase over the
short-term.
Technologies are common and
widely accepted. Unusual
permits are not anticipated.
$2.226.929
Alternative 4
Channel Reconstruction,
Revtgefalion.Sedlment Dams
and Wetlands
Reduces erosion and releases to
surface water and groundwater
associated with stream flow but
not precipitation. Does nol
address wind'erosion.
Complies wiih all ARARs.
Combines elTecliveness
described for Alternatives 2 and
3
Overall volume of water
contacting wasle rock would be
reduced. Mobility of
contaminants from the site would
also be reduced. Toxicity is
unchanged and treatment is nol
included.
Engineering controls would be
used to reduce the short-term risk
to the community due to dust
emissions and exposure of
workers to contaminants. Road
traffic would increase over the
short-term.
Technologies are common and
widely accepted, except wetlands
would require studies. Permit
may be required for haulage.
$2.544.293
Alternative S
Channel Reconstrurtlon,
Revegetation, Sedin tnl Dams,
Wetlands, and Selected Surface
Material Removal
Alternative 5 combines the approaches
described for Alternatives 2. 3 and 4.
The channel of upper California Gulch
would be reconstructed, disturbed areas
amended as necessary and revegelated,
sediment control dams constructed and
wetlands constructed.
Same as Alternative 2.
Combines effectiveness described for
Alternatives 2, 3 and 4.
Combines reductions described for
Alternatives 2, 3 and 4.
Same as Alternatives 2, 3 and 4.
Same as Alternatives 2, 3 and 4.
$2.653.493
Source: TerraMatrix/SMI 1998
'The No Action alternative will incur incidental costs related lo the 5-year review, monitoring and administrative issues
-------
TABLE 17
COST SUMMARY: GARIBALDI SUB-BASIN WASTE ROCK ALTERNATIVE 2 -
SURFACE WATER DIVERSION, STREAM CHANNEL RECONSTRUCTION
California Gulch NPL Site
OU4-FFS-UCC-IJ9A
Alterative 2 • Surface Water Divcnion. Stream Chanad Reconstruction
DIRECT CAriTAL COSTS
Componcni
Channel Construction
Rip Rap
Lined
Unlined
Culvert
Construct Access Road
Sown Reconstruction
Waste Rock Stabilization
Cuhttnl Reioufccs
Dust Control
Sedimenl Control
Unit Unit Con
ey
if
it
If
If
If
If
lump
lump
lamp
Ouannty TouJ Cost
S6JOO
$19.123
$2.150
$1.300
J 1.373
$13.123
$3.500
$3.000
52.000
$2.000
TOTAL DIHECT CAPITAL COS1S
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (21% of Direct)
Legal Fees (3% of Direct)
Refubtory Coil (3% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Feei (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAffTA!. COSTS
TOTA1. CAPITAL CO.S7S
$5,691
$14.244
$2.S49
$2.849
$IIJ95
$3.911
SJ6.tr]
S4I.022
$97.997
POST REMEDIATION SITE CONTROL COSTS
Ditcouni 7.00% for present worth
Componeni
Unit
Unit Cost
Each
Each/year
Vyear
Yean
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour S40
Erosion Repair lump $2.000
Vegetation Repair lump SO
TOTA1. DIRECT OAMPRtSKtfT WORTH
$1.2*0
$2.000
SO
30
5
3
$134*4
UJOO
SO
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (3% of Annual Direct O&M)
Misc. Fees (3% of Annual Direct O4M)
Reserve (23% of Annual Direct OAM)
TOTAL INniRKCTOAMFRKiKNTlWItTIt
1VTAL OPERATION AND kUltfTKNA^Ci: rRKSEffr WOKTIt
$1.204
$1.204
S6.02I
S.1.J19
Sil.Sli
CKAND TOTAL
tuo.iie
Source: 1crmMatru/\\n I99X
f V11KKBI fff 1*1* H*«-IT It. I/II/M
-------
TABLE 18
COST SUMMARY: GARIBALDI SUB-BASIN WASTE ROCK ALTERNATIVE 3 •
SURFACE WATER DIVERSION, SELECTED REMOVAL
California Gulch NPL Site
OU4-FFS-UCG-I09A
AJttnuOvt 3 • Surface Water Diversion. Selected Removal
DIRECT CAPITAL COSTS
Component
Unit UaitCea Quantity Total Cotl
Channel Construction
RipRjp
Unlincd
Culvcn
Construct Acceu Road
Wane Rock Toe SubilizMion
Waste Rock Removal
Cultural Reioittces
Dust Control
Sediment Control
TOTAL DIRECT CAflTAL COSTS
ey
a
a
ir
ir
if
ey
lump
lump
lump
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5X of Direct)
Regulatory COM (5% of Direct)
Mobilization and Demobilization POM of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL IHI3IKKCT CAPITAL COSTS
TOTAL CAI'ITAI. CO51S
$2.520
$19.125
12450
SI.500
SI .575
SI 5.000
SIO.OOO
S5.000
$2.000
S2.000
S6.IS7
$15.393
$3.079
J3.079
SI2JU
$4,310
ui.s'o
S44J30
SI05.900
POST REMEDIATION SITE CONTROL COSTS
Discount 7.00% for present worth
Component
Unit
Unit Cast
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump SO
Each
1
1
1
Each/yew
4
1
Vyear
SIJSO
$2.000
$0
Years
30
5
5
Present
Worth
$I5.I»4
$1.200
SO
TOTAL DIKXCTOAM PRESENT WORTH
Component
SU.01I4
• I ucnt
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Admiaistntion (5% of Annual Direct O*M)
Misc. Fees (5% of Annual Direct O4M)
Reserve (25% of Annual Direct O&M)
TOTAL INimiX-TOAM rKKSENT WORTH
TOTAL OPKKATIIM AND UAIttTKNAKCE I'RKSENT IfOKTII
SIJ04
SU04
S6.02I
W.-O9
SJl.ilJ
GRAND TOTAL
Smrct:
-------
TABLE 19
COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 2 -
STREAM CHANNEL RECONSTRUCTION
California Gulch NPL Site
OU4-FFS-UCG92A
Alternative 2 - Stream Channel Reconstruction
DIRECT CAPITAL COSTS
Component
Unit Unit Cost Quantity Total Cost
Improve Access Road
Channel Construction
Riprap Placement
Cultural Resources
Dust Control
Sediment Control
TOTAL DIRECT CAPITAL COSTS
ey
lump
lump
lump
$3.00
$63.00
52,000
S2.000
12,000
700 $2.100
240
$15.120
$2,000
$2.000
$2,000
S2J.220
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost ($% or Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20V. of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$2,322
$5.805
$1,161
$1.161
$4.644
$1.625
316.718
SJ9.9J8
POST REMEDIATION SITE CONTROL COSTS
Discount 7 00% for present utmh
Component
Unit
Unit Cost
Each Each/year
S/year
Years
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump $1.200
TOTAL DIRECT O&M PRESENT WORTH
Component
4 $1.280
I $2,000
0 $0
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Annual Direct O&M)
Misc. Fees (5% of Annual Direct O&M)
Reserve (25% of Annual Direct O&M)
TOTAL INDIRECT O&U PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
Present
Worth
4 $4,336
4 $6.774
4 SO
HI.IIO
Present
Worth
$556
$556
$2.778
SJ.U9
SI-1.999
GRAND TOTAL
M.9J7
Sourct: TtrroMoiru/SMI 1998
-------
TABLE 20
COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 2 -
STREAM CHANNEL RECONSTRUCTION AND REGRADINC
California Gulch NPL Site
OU4 - FFS - UCG 92A
Alternative 3 - Stream Gunnel Reconstruction/Regrade Wane Rock
DIRECT CAPITAL COSTS
Unit Unit Cost Quantity Total Cost
Improve Access Road If $3.00 700 $2.100
Regnde Waste Rock cu-yd SI.00 300 $300
Channel Construction
Riprap Placement cy $63.00 240 SI5.120
Cultural Resources - lump $2,000 I $2,000
Dust Control lump $2.000 I $2.000
Sediment Control lump $2.000 I $2.000
TOTAL DIRECT CAPITAL COSTS
I23.UO
INDIRECT CAPITAL COSTS
Engineering and Design (10*4 of Direct)
Contingency (25% of Direct)
Legal Fees (SV. of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20V. of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$2.352
55,880
$1.176
$1.176
$4.704
$1.646
3I6.9JJ
SJO.-D-I
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year $/year
Years
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump $1.200
TOTAL DIRECT OAM PRESENT WORTH
Component
SI,280
$2.000
$0
$4.336
$6.774
$0
iii.no
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT OAM PRESENT WORTH
TOTAL OPERA. ION AND klAINTENANCE PRESENT WORTH
$556
$556
$2,778
SJ.S89
SH.999
GRAND TOTAL
SS5.1S3
Source: TerroMatru/SMI 1998
t Uiu
-------
TABLE2I
COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 4 -
WASTE ROCK REMOVAL
California Gulch NPL Sile
OLM Focused Feasibility Study - UCG 92A
Alternative 4 • Remove Waste Rock in Stream to UCG-71/Revegetate
DIRECT CAPITAL COSTS
Unit
Unit Cost Quantity Total Cost
Connnict Access Road If 15.23 700 J3.675
Channel Construction
Riprap Placement cy S63.00 ISO SI7.640
Diversion Ditehs sq-fl $5.00 1010 S5.400
Culverts If S50.00 40 S2.000
Load and Haul Waste Rock ~ eu-yd SI0.00 300 SI.OOO
Amend Soil and Revegeution acre Sl.tOO 1.0 S1.IOO
Cultural Resources lump J2.000 I $2.000
Dust Control lump $2,000 I $2.000
Sediment Control lump $2.000 I $2.000
TOTAL DIKKCTCAriTAL COSTS
S-IJ.8IS
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5V. of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% or Direct)
EPA Fees (20% of Engineering. 5% or Direct)
TOTAL INDIRECTCAIVTA!. COSTS
TOTAL CAPITAL COSTS
S4.5S2
$11.454
S2.29I
$2.291
$9.163
$3.207
S32.9S-
S-8.801
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year $/ye»r
Years
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump 12.000
Vegetation Repair lump S 1,200
TOTAL DIIUiCTOAMFKKSFJrr WORTH
4 $1.2 tO
I 12.000
I $1.200
4 JOW
4 $6.774
4 S4.065
Sli.l't
Component
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct OAM)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL WMKKCTO&MFRKiKNT WORTH
7VTAL Or KM TION AM) kUINlKNANCK I'HKSMT WOKTH
$759
5759
S3.794
3i.il I
Somr: Ttmi\lairaft\ll 1998
GRAND TOTAL
ttf.Jtt
mfM-lltlt into*
-------
TABLE 22
COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 2 -
DIVERSION DITCHES
California Gulch NPL Site
OU4 - ITS - KUGGET GULCH
Alternative 2 - Diversion Channels
DIRECT CAPITAL COSTS
Component
Improve Acceu Roads
Channel Construction
Ripnp
Lined
Unlined
Culveru
Drainage Gravel
Gettextile
Perf. Drain Pipe
Cultural Resources
Dust Control
Sedimem Control
Unit
If
ey
if
if
If
ey
«f
If
lump
llHTtp
lump
Unit Cost
$3.00
$63.00
J7JO
$2.00
$50.00
SI 7.00
SOJ5
S45.00
S 10.000
S5.000
S5.000
Quantity
200
370
1.050
15.600
60
210
6.500
250
1
1
1
Total Cost
1600
123 J 10
J7.I75
$31.200
S3.000
S4.760
S2.275
SI 1.250
SIO.OOO
S3.000
$5.000
TOTAL DIRECT CAPITAL COSTS
sitn.ro
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25V. of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5V. of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAI'ITAl. COSTS
TOTAL CArtTAI. COSTS
$10.427
$26.068
$5.2 M
SSJI4
$20.854
S7J99
S~i.0'4
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year Vyear
Yean
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump SIO.OOO
Vegetation Repair lump SO
TOTAL DIRECT OAMrRESENT WORTH
Component
24
1
1
4 $3.WO
1 $10.000
1 SO
30
5
5
$47.651
$41.002
$0
383.65}
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
$4.433
$4.43)
$22.163
TOTAL I
TOTAL OI'KRATIONANDklAllfTKNANCKriUSKtfrWORTH
SI/V.6H!
GRAND TOTAL
S199.0J6
Sourer TtmiMutniKMI I'jy.f
-------
TABLE 23
COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 3 -
DIVERSION DITCHES AND WASTE ROCK REGRADING
California Gulch NPL Silt
OU4 - FFS - NUGGET GULCH
Alternative 3 - Regnde UCG-71.74. 76. 77. 15/Divcnioi ChanneUTemces
DIRECT CAPITAL COSTS
Componeni
Unii
Unii Coa Quantity ToUl Coil
Improve Access Road
lUfndini
Qvannel Construction
Riprap
Lined
Unlined
Culverts
Construct Tances
Amend &Reveg
Drainage Gravel
Geamile
Pen. Drain Pipe
Cultural Resources
Dun Control
Sediment Control
ir
ey
ey
if
sf
If
If
ac
«y
sf
If
lump
lump
lump
S3.00
SI.OO
$63.00
$7 JO
$2.00
JJO.OO
J3.00
U.IOO
SI 7.00
SOJ5
S45.00
110.000
$5,000
$5.000
500
14.200
370
1.050
15.600
60
600
1
210
6400
250
1
1
1
$1.500
$14.200
$23410
$7,175
$31.200
$3.000
$1400
SS.IOO
(4.760
$2^75
SIU50
SI 0.000
$5.000
$5.000
TOTAL DIRfCTCArrTAL COSTS
sii9.ro
INDIRECT CAPITAL COSTS
Engineering tndDcitfn(IO%of Direct) .
Contingency (25% of Direct)
LepJ Fee» (5% of Direct)
Rcpibiory Cost (5% of Direct)
MobiliaMion and Demobilizaiion (20% of Direct)
EPA Fees (20% of Engineering. 5% ot Direct)
TOTAL INDIRECT CAPITAL COSTS
1VTAL CAflTAl. CHS1S
$12.927
$32.318
S6.464
S6.464
$25.154
S9.CW9
S9].0"-l
POST REMEDIATION SITE CONTROL COSTS
Discount
7.00% for present worth
Present
Component Unit Unit Cost Each Each/year S/year Yean Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour S40 24 4 S3.WO 30 S47.65I
Erosion Repair lump $10.000 1 1 $10.000 5 W 1.002
Vegetation Repair lump $5.000 1 I S5.000 5 $20.501
TOTAL DIRECT OtMfRKSENT WORTH
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O4M)
Misc. Fees (5% of Direct OAM)
Reserve (75% of Direct O4M)
3109.1 U
Present
Worth
S5.45S
S5.45S
S27.2I9
WTAI. INDIRECT MM PRKSKNT WORTH
TOTAL OI'KKATION AND AM/Af77;WXA'C/: PRKSKIfT H'ORTII
SJH.10J
GRAND TOTAL
Sourer: TtrruMiaru/SMI I99X
litt.m
-------
TABLE 24
COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 4
DIVERSION DITCHES, CONSOLIDATION AND COVER
California Gulch NPL Silt
OtM - ITS - NUGGET GULCH
Alternative 4 - Move UCG-74.76. 77.1510 UCG-71 /Arnold and Revtfctate UCG-74.76.77. IV
Repadc UCG-71, Simple Cover. Revcfeuie UCG-7 l/Divenion Qunndi/Tcmees
DIRECT CAPITAL COSTS
Component
Unit Unit Cost
Quantity Total Con
Improve Access Road
Load aad Haul Waste Rock
Amend and Revefetation
Cover Material and Placemen!
Revefctaie UCG-71
Rcfradiai
Channel Construction
Riprap
Concrete
Unlincd
Culveru
Terraces
Cultural Resources
Oust Control
Sediment Control
If
ey
ac
ey
ac
ey
ey
it
tf
\{
If
lump
lump
lump
S3.00
$5.00
U.IOO
SI 1.75
SS.IOO
SI.OO
$43.00
$7 JO
S2.00
S50.00
S3.00
SIO.OOO
S5.000
S5.000
500
19450
6.00
IJOO
5.00
19.230
300
1.050
10.400
60
1.750
1
1
1
SI .500
$96.250
S4I.600
$97.525
$40.500
$19.250
SI 1.900
S7.I75
$20.100
$3.000
$5.250
SI 0.000
$5,000
$5.000
TOTAL DIRECT CAPITAL COSTS
INDIRECT CAPITAL COSTS
En(incerinf and Design (10% of Direct)
Cominfcncy (25% of Direct)
Legal Fees (5V. of Direct)
Repilatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20V. of Engineering, 5V. of Direct)
TOTAL INniRt'.CTCAI'ITAL COSTS
TOTAL CAriTALCOSlS
$37.945
S94.863
$11.973
$18.973
$75.890
$26.562
Sl'J.20-1
S611.6S-I
POST REMEDIATION SITE CONTROL COSTS
Discount TJtOVt for present worth
Component Unit Unit Cost Each Each/year S/year
DIRECT OPERATION AND MAINTENANCE
Inspection hour S40 24 4 $3.140
Erosion Repair lump SIO.OOO 1 1 SIO.OOO
Vegetation Repair lump $5.000 1 1 $5.000
TOTAL UlW.CTO&MrH£SFjrrWOimi
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct OiM)
Misc. Fees (5V. of Direct OAM)
Reserve (25% of Direct O&M)
Present
Yean Worth
30 $47.651
5 $41.002
5 $20.501
5/OT./JV
Present
Worth
$5.458
$5.451
J27.2S9
TOTAL
TOTAL OI'KKATION AND MAItfTENANCK PHKSKNT WORTH
S3H.10J
CKAND TOTAL
Sourtt: 1emi\lufru/SMt 199.1
uto.ou
-------
TABLE 25
COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE 2 -
DIVERSION DITCHES
California Gulch NPL Site
OU4FFS- AY-MINNIE
Alternative 2 - Diversion Channels
DIRECT CAPITAL COSTS
Component
Unit Unit Cost Quantity ToUl Cost
Channel Construction
Rip Rap cy $63.00 350 $22,050
Lined »f $7.50 5.100 $38,250
Unlined if $2.00 4.300 $8.600
Culvert - If $50.00 30 SI ,500
Cultural Resources lump $5.000 I $5,000
Dust Contra! lump $2,000 I $2.000
Sediment Control lump $2.000 I $2.000
TOTAL DIRECT CAPITAL COSTS
179.400
INDIRECT CAPITAL COSTS
Engineerini and Desif n (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% or Direct)
EPA Fees (20% of Engineering, 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$7.940
$19.850
$3.970
$3.970
$15.880
$5.558
SS7./6S
SI36.i6S
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year S/year
Years
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2.000
Vegetation Repair lump SO
TOTAL DIRECT O&M PRESENT WORTH
Component
4 $1,280
1 J2.000
I $0
30
5
5
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O£M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT O&M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
Present
Worth
$15.884
$8.200
SO
SH.OS-I
Present
Worth
$1.204
$1.204
$6.021
S32.S1}
GRAND TOTAL
SI69.0SI
Source: TtrroMairix/SMI 1998
-------
TABLE 26
COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE 3 -
DIVERSION DITCHES AND REGRADING
California Gulch NPL She
OU4FFS-AY-MINNIE
Alternative 3 - Diversion Channels/Regrading
DIRECT CAPITAL COSTS
Component
Unit Unit Cost Quantity Total Cojt
Channel Construction
Rip Rap
Lined
Unlincd
Culven
Regrading
Cultural Resource!
Dust Control
Sediment Control
ey
$r
if
If
ey
lump
lump
lump
J63.00
$7 M
S2.00
S50.00
$1.00
$5.000
$2.000
$2.000
350
5.100
4400
30
8.750
1
1
1
S22.0SO
$38,250
SS.600
$1,500
S8.750
$5.000
$2,000
$2.000
TOTAL DIRECT CAPITAL COSTS
US. I SO
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering, 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$8,815
$22,038
$4.408
$4.408
$17.630
$0.171
S63.J68
SISI.6IS
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year $/year
Yean
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump SO
TOTAL DIRECT O&M PRESENT WORTH
Component
4 $1.280
1 $2.000
1 $0
30
5
5
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT O& M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
Present
Worth
SI 5.814
$8.200
$0
M.M-I
Present
Worth
SUM
$1.204
$6.021
IS.-I29
S32.SIJ
GRAND TOTAL
SII4.IJI
Souret: TtrraMairOSMI 1998
-------
TABLE27
COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE 4 •
DIVERSION DITCHES AND ROAD RECONSTRUCTION
California Gulch NPL Site
OU4FFS-AY-MINNIE
Alternative 4 - Diversion Channels/Realign Road/Sediment Pond
DIRECT CAPITAL COSTS
Component
Unit Unit Con
Quantity Total Cost
Channel Construction
Rip Rap
Unlincd
Culvtrt
Road Work
Earthworks
Sub-Base
Pavement (3 in)
Sediment Dim
Calami Resource*
Dial Control
Sediment Control
TOTAL DIRECT CAPITAL COSTS
ey
»f-wp
ey
If
ey
ey
»y
lump
lump
hmp
lump
$63.00
17.50
S2JO
$43.00
51.00
136.50
15.40
J5.000
S5.000
12.000
J2.000
350 $12,050
5.100 $31.250
4.300 $10,750
30 $1,290
1442
4(5
2.912
I
I
$1442
JI7.703
SI 5.725
$5,000
55,000
$2.000
$2.000
SHI. 109
INDIRECT CAPITAL COSTS
Enfmceriai and Ocsifn (10% of Direct)
Contintency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineerinc. 5% of Direct)
TOTAI. INDIRECT CAPITAL COSTS
TOTAI. CAPITAL COSTS
$12.111
$30.277
So.055
$6.055
$24.222
$S.47S
U'.ltS
SIM.JO-
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year $/yeir
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
ScdineM Removal See Flvuial site 4
Erosion Repair hmp $2.000
Vefcuuion Repair lump $0
TOTAL DIRKCTO&M PRESENT tYORTH
$1.210
30
I $2.000 5
I $0 5
$I5.U4
$8JOO
$0
J.'V.ftW
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Adminismion (5% of Direct O&M)
Misc. Fees (5% of Direct O4M)
Reiervc (25% of Direct O&M)
TOTAI. INU/KKCTOAMrRKSKtfT WORTH
TOTAL OPKRATION AND MAIIfTENANCK PRESEIfT WORTH
Worth
SUM
$1.204
$6,021
U.-I19
Sil.fli
GRAND TOTAL
1240.110
Somrct: Ttrnifflairu/SMI 199ft
-------
TABLE 28
COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 2 -
DIVERSION DITCHES
California Gulch NPL Site
OU4 - FFS - UCG-12
Alternative 2 - Divenion Channels
DIRECT CAPITAL COSTS
Component
Unit Unit Cost Quantity Tout Cost
Improve Access Road
Divenion Channels
Amend Soil and Revegetation
Cultural Resources
Dust Control
Sediment Control
If
sq-ft
acre
_ lump
lump
lump
53.00
$7.50
$8.100
52.000
55.000
52.000
2,000
1.000
3J
1
1
1
56,000
57.500
526.730
52.000
55.000
52.000
TOTAL DIRECT CAPITAL COSTS
549.230
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPTTAL COSTS
54,923
512.308
52.462
52.462
59,846
53.446
S3S.-H6
58-1.676
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cosl
7.00% for present worth
Each Each/year I/year
Years
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour 540
Erosion Repair lump 52,000
Vegetation Repair lump 50
TOTAL DIRECT O&M PRESENT WORTH
Component
4 51.280
I 52.000
I 50
30 515,884
5 58.200
5 50
52-1.08-1
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIREC, O&M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
51.204
51.204
56.021
58.-I29
S32.SIJ
GRAND TOTAL
5117.189
Source: TerraMatra/SMI 1998
-------
TABLE 29
COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 3 -
REGRADING AND COVER
California Gulch NPL Site
OU4-FFS-UCG-I2
Alternative 3 • Minor Grading/Simple Cover/RevegetatJon
DIRECT CAPITAL COSTS
Component
Unit Unit Goit Quantify Total Cost
improve Access Ro*d
Regrade
Cover Soil Supply
Cover Soil Placement
Revegeuiion
Cultural Resources
Dust Control
Sediment Control
If
cu-yd
cu-yd
' cu-yd
•ere
lump
lump
lump
53.00
JI.OO
$10.00
$1.75
$8,100
$2,000
$5.000
$2.000
2.000
1.000
1.700
1.700
3.7
1
1
1
$6.000
$1.000
$17,000
$2.975
$29.970
$2.000
$5.000
$2.000
TOTAL DIRECT CAPITAL COSTS
165.94!
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25V. of Direct)
Legal Fees (5V. of Direct)
Regulatory Coil (5V. of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20V. of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$6.595
SI 6.486
$3,297
$3.297
$13.189
M.6I6
UT.4SO
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year J/year
Yean
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump $2.500
TOTAL DIRECT O&MPRESENT WORTH
Component
4 JI.280
I $2.000
I $2.500
30 $15.1*4
5 $1.200
5 $10.250
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O4M)
Misc. Fees (5V. of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT O&MPRESENT WORTH
TOTAL OPERA TION AND MINTENANCE PRESENT WORTH
Present
Worth
$1.717
$1.717
$8.584
SI2.017
U6.JSI
GRAND TOTAL
SIS9.776
Source: TtrroMaira/SMI 1998
-------
TABLE 30
COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 4 -
WASTE ROCK CONSOLIDATION
Ctlifomit Gulch NPL Site
OU-4 Focused Feasibility Study - UCG 12
Alternative 4 • Remove Waste Rock to UCG-71
DIRECT CAPITAL COSTS
Component
Unit
Unit Cost Quantity Total Cost
Improve Access Road If 13.00
-Load and Haul Waste Rock cu-yd SI 1.00
Cultural Resources lump $2,000
Amend Soil and Revegctation _ acre $8.100
Dust Control lump $5,000
Sediment Control lump 12,000
TOTAL DIRECT CAPITAL COSTS
2,000
5.300
1
3.7
$6,000
$60.500
$2.000
$29.970
$5.000
$2.000
SIOS.470
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$10.547
$26468
$5.274
55.274
$21,094
$7.383
S7S.938
5181.JOS
POST REMEDIATION SITE CO.VTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year $/ycar
Years
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2.000
Vegetation Repair lump $2,500
TOTAL DIRECT O&M PRESENT WORTH
Component
SI .280
$2.000
$2.500
30
5
5
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (S% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT O&M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
Present
Worth
$15.884
$8.200
$10,250
S3J.33J
Present
Worth
$1.717
$1.717
$8.584
SI2.0/7
S-I6.3SI
GRAND TOTAL
Source: TtrraMaira/SMI 1998
S227.7J9
t UlI»-ai)W4W»WUW-M nil
-------
TABLE 31
COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 2 -
CHANNEL RECONSTRUCTION
California Gulch NPL Site
OU4 - FFS - California Gulch Waste Rock Piles
Alternative 2 - Stream Channel Reconstruction (-2.150 feet)
DIRECT CAPITAL COSTS
Component Unit
Improve Access Road If
Channel Preparation
Excavation cy
Grading cy
Riprap Lining * cy
Surface Regrading ac
Amend Soil and Reveg ' ac
Cultural Resources lump
Dust Control lump
Sediment Control lump
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
Unit Cost
J3.00
S2.50
J2.50
S63.00
$1.000
SS.IOO
$10,000
$1,000
$1,000
Quantity
500
9.175
3.375
4.175
4
4
1
1
1
Tout Cost
$1.500
$22.931
S8.43S
$263.025
$4.000
$32.400
$10.000
$1.000
$1.000
$29.990
$74.975
$14.995
$14,995
S59.980
$20.993
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
1299.900
SJIS.fM
S5I5.S2S
POST REMEDIATION SITE CONTROL COSTS
Discount
7.00% for present worth
Component Unit Unit Cost Each Each/year
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40 8 4
Erosion Repair • lump $2.000 1 1
Vegetation Repair lump SO 1 1
TOTAL DIRECT O&M PRESENT WORTH
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct OiM)
Mite F«cj(5%ofDircctO&M)
Reserve (25% of Direct O&M)
Present
$/year Yean Worth
$1.280 30 $15.884
$2.000 5 $8.200
SO 5 SO
S2-I.03J
Present
Worth
$1.204
$1.204
$6.021
TOTAL INDIRECT O&M PRESENT WORTH
TOTAL OPERA TION AND MAINTENANCE PRESENT IVORTH
S32.JIJ
GRAND TOTAL
Souret: TtrroMoira/SMI 1998
-------
TABLE 32
COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 3 -
SELECTED REGRADING
California Gulch NPL Site
OlM - FFS - California Gulch Waste Rock Piles
Alternative 3 • Waste Rock Regrading
DIRECT CAPITAL COSTS
Component
Unit Unit Cost Quantity Total Cost
Improve Access Road If J3.00 1.200 $3,600
Regrade cu-yd Sl.OO 7,300 S7.500
Cultural Resources lump $2,000 I $2.000
Dust Control lump $5,000 1 $5,000
Sediment Control lump $2,000 I $2,000
TOTAL DIRECT CAPTTAL COSTS
520.100
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering, 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$2.010
S5.025
$1.005
$1.005
$4.020
$1.407
131.572
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unil Cost
7.00% for present worth
Each Each/year S/ye«r
Years
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump 22,500
TOTAL DIRECT OAM PRESENT WORTH
Component
$1,280
$2.000
SO
30
5
0
$15.884
$8,200
$0
12-1.03-f
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT O&M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
$1.204
$1.204
S6.021
S8.429
S32.SI3
GRAND TOTAL
Source: TerraMalrix/SAff 1998
567.045
puito-oi>wi>M»>wiiM.)i «ii
-------
TABLE 33
COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE 4 -
SELECTED WASTE ROCK REMOVAL
California Gulch NPL Site
OU4 - FFS • California Gulch Waste Rock Piles
Alternative 4 - Remove Waste Rock to UCG-71
DIRECT CAPITAL COSTS
Component
Unit
Unit Cost Quantity Total Cost
Improve Access Roads If $3.00 UOO $3.600
-Load and Haul Waste Rock cu-yd SI 1.00 15,000 5165.000
Cultural Resources lump $10,000 1 SI0.000
Amend Soil and Revegeution .acre $8,100 3.7 $29,970
Dust Control lump $10,000 I SI0.000
Sediment Control lump $2,000 1 $2,000
TOTAL DIRECT CAPITAL COSTS
S220.S70
INDIRECT CAPITAL COSTS
Engineering and Design (10% of Direct)
Contingency (25% or Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5V. of Direct)
Mobilization and Demobilization (20% of Direct)
EPA Fees (20% of Engineering, 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$22.057
$55.143
$11.029
$11.029
$44.114
$15.440
SI 58.810
S379.380
POST REMEDIATION SITE CONTROL COSTS
Component
Unit
Discount
Unit Cost
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2,000
Vegetation Repair lump $2,500
7.00%
Each
8
1
1
for present worth
Each/year
A
1
1
$/ycar
$1.280
$2,000
$2.500
Yean
30
5
5
Present
Worth
$15.884
S8.200
$10,250
TOTAL DIRECT OA M PRESENT WORTH
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O&M)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct O&M)
TOTAL INDIRECT O&M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
JJV.JJV
Present
Worth
$1.717
$1.717
$8.584
il2.017
H6.3SI
Sourct: TerroMatrix/SMI 1998
GRAND TOTAL
t42 5,731
-------
TABLE 34
COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 2 •
CHANNEL RECONSTRUCTION AND REVECETATION
California Gulch NPL Stic
OU4-FFS-FLUVIAL SITE 4
Alternative 2 • Stream Channel Reconstniction/Suiface Stabilization
DIRECT CAPITAL COSTS
Component
Unit Unit Coil Quantity Total Cost
Imptove Access Road
Channel Preparation
-' Excavation
Grading
Riprap Lining
Surface Regrading
Amend Soil and Reveg
Cultural Resources
Dusi Control
Sediment Control
TOTAL DIRECT CAPITAL COSTS
If
$3.00
700
$2.100
ey
«y
ty
K
ac
lump
lump
lump
JZ50
$2.50
$63.00
J 1.000
St. 100
SI 5.000
$4.000
$2.000
36.700
13.300
16.700
16
16
1
1
1
$91.750
$33.750
$1.052.100
$16.000
$129.600
$15.000
$4.000
$2.000
SI.H6.300
INDIRECT CAPITAL COSTS
Engineering and Design (15% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (10% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$201.945
$336.575
S67.3I5
$67.315
$134.630
$107,704
S9IS.-W
S2.26I.78-I
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unil
Unit Cost
7.00% for present worth
Each Each/year $/year
Years
Present
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40
Erosion Repair lump $2.000
Vegetation Repair lump $18,000
TOTAL DIRECTO&U PRESENT WORTH
Component
SI.2SO
$2.000
$18.000
30
5
5
$15.884
$8.200
$73.804
597.888
Present
Worth
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct OiM)
Misc. Fees (5% of Direct O&M)
Reserve (25V. of Direct O&M)
TOTAL INDIRECT O& M PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
$4.894
$4.894
$24,472
SJ-I.26I
SIJ1.U9
GRAND TOTAL
S2J9J.9JJ
Source: Ttrroklatru/SMI 1998
^4 o, i/ivn
-------
TABLE 35
COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 3 -
CHANNEL RECONSTRUCTION. SEDIMENT DAMS AND WETLANDS
California Gulch NPL Site
OU4-FFS-FLUVIAL SITE 4
Alternative 3 - Stream Channel Reconstruction/Sediment Dams and Wetland*
DIRECT CAPITAL COSTS
Component
Unit Unit Cost
Quantity Total Cost
Improve Access Road If $3.00 700 $2.100
Channel Preparation'
Excavation cy $2.50 36.700 $91.750
Gliding cy $2.50 13400 $33.750
Riprap Lining cy $6300 16.700 $1.052.100
Sediment Dams lump SS.000.00 I $64.000
Constructed Wetlands ac SI7.000.00 1.5 $25.500
Surface Regnding ac J 1,000 16 $16.000
Cultural Resources lump SI5.000 I SI5.000
Oust Control lump $4.000 I $4.000
Sediment Control lump $2.000 I $2.000
TOTAL DIRECT CAPITAL COSTS
Sl.306.200
INDIRECT CAPITAL COSTS
Engineering and Design (15% or Direct)
Contingency (25% ofDireci)
Legal Fees (5% of Direct)
Regulatory Cost (5% ofDireci)
Mobilization and Demobilization (10% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
$195.930
$326.550
$65.310
$65.310
$130.620
$104.496
S88S.2I6
H.I9-I.JI6
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% for present worth
Each Each/year S/year
Years
DIRECT OPERATION AND MAINTENANCE
Inspection hour S40
Erosion Repair lump . $2.000
TOTAL DIRECT Od A/ PRESENT WORTH
Component
$1.2(0
$2.000
30
5
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct OiM)
Misc. Fees (5% of Direct O&M)
Reserve (25% of Direct OiM)
TOTAL INDIRECT O&M'PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
Present
Worth
SI5.U4
$8.200
S3-I.03-I
Present
Worth
$1.201
$1.204
$6.021
UM9
S32.SIJ
GRAND TOTAL
Sourct: TtrroMoiru/SMI 1998
r \juajin
-------
TABLE 36
COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 4 -
STREAM CHANNEL RECONSTRUCTION, SURFACE STABILIZATION, SEDIMENT DAMS AND WETLANDS
California Gulch NPL Site
OU4 - ITS - FLUVIAL SfTE 4
Alternative 4 • Stream Channel Reconstruction/Surface Stabilization/Sediment Dun* and Wetlands
DIRECT CAPITAL COSTS
Component
Unil Unit Con
Quantity Tout Con
Improve Access Road
Channel Preparation
Excavation
Cnding
Riprap Lining
Sediment Dams
Constructed Wetlands
Amend Soil and Reveg
Surface Regnding
Cultural Resources
Dust Control
Sediment Control
If
ey
ey
ey
lump
ac
ac
ac
lump
lump
iuntp
13.00
SZSO
5240
$63.00
H.000.00
SI7.000.00
St.100
$1.000
S 15,000
$4.000
52.000
700
36.700
13400
16.700
S
1.5
16
16
1
1
1
52.100
591.750
533.750
51.052.100
564.000
$25400
5129.600
516.000
515.000
54.000
52.000
TOTAL DIRECT CAPITAL COSTS
Si.JJJ.800
rNDlRECT CAPITAL COSTS
Engineering and Design (15% of Direct)
Contingency (25% of Dirrci)
Legal Fees (5% of Direct)
Regulatory Cost (5% of Direct)
Mobilization and Demobilization (10% of Direct)
EPA Fees (20% of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL COSTS
TOTAL CAPITAL COSTS
5215.370
$358.950
$71.790
$71.790
$ 1434*0
$114.164
si.4ii.m
POST REMEDIATION SITE CONTROL COSTS
Discount
7.00% Tor present worth
Component Unit Unit Cost Each Each/year
DIRECT OPERATION AND MAINTENANCE
Inspection hour S40 1 4
Erosion Repair lump 52,000 1 1
Vegetation Repair lump SI 1.000 1 1
TOTAL DIRECT O&M PRESENT WORTH
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct Q&M)
Misc. Fees (5% of Direct OAM)
Reserve (25% of Direct O&M)
Present
S/year Years Worth
$1.210 30 $15.114
$2.000 5 $1.200
$11.000 5 S73.S04
sv.saa
Present
Worth
$4.194
$4.194
$24.472
TOTAL lf/0/KKCi MM I-RISKNT WOKTII
TOTAL OPERA 77OV AND HUIffTKNANCK J'RKSt-W WORTH
SH.26I
SI11.H9
GRAND TOTAL
Haunt: TtrruMuirMSMI 1998
iMii ••*»! 14 attain*
-------
TABLE 37
COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 5 -
STREAM CHANNEL RECONSTRUCTION, SURFACE STABILIZATION. SELECTED REMOVAL,
SEDIMENT DAMS AND WETLANDS
Caiibmia Gulch NFL Site
OLM-ITS-FLUVIAL SITE 4
Alternative 5 - Stream Chanel RctaumxtMO/SurfKC StthiKfiricn/Sctettcd Renovil/Scdimenl Dams ipd Wetlands
DIRECT CAPITAL COSTS
Component
Unh Unit Cott
Quantify Total Cost
Improve Access Road If
Excavation ey
Gnding cy
rUprap Lining ey
Sediment Dams lump
Excavate Surface Material cy
Sediment tUieniion Cribbing It
Consumed Wetlands *c
Amend Soil and Revcf ac
Surface Regnding K
Cultunl Resources lump
Dust Control lump
Sedimenl Control lump
TOTAL D/KECTCAffTAL COSTS
$2.100
$91,500
J3J.7JO
SI.OJ2.IOO
164,000
J40.000
S25.000
S23JOO
JIW^OO
$ 16.000
SI 5.000
S4.000
S2.000
SI.MO.tOO
INDIRECT CAPITAL COSTS
Eaf inceriai and Design (15% of Direct)
Contingency (25% of Direct)
Legal Fees (5% of Direct)
Regulatory Cost (1% of Direct)
Mobilization and Demobilization (10% of Direct)
EPA Fees (30% of Engineering. 5% of Direct)
TOTAL INDIRECT CAPITAL CO57S
1OTAI. CAPITAL COSTS
S225.I20
S37J.200
$73,040
S75.040
SI50.0SO
S 120.064
st.ox.m
POST REMEDIATION SITE CONTROL COSTS
Discount
Component
Unit
Unit Cost
7.00% far praent worth
Each Each/year Vycat
Yean
Worth
DIRECT OPERATION AND MAINTENANCE
Inspection hour S40
Erosion Repair lamp S2.000
•Vegetation Repair lump SI 1.000
TOTAL DIRECT OAMHlFSEtrT WORTH
SUM
S2.000
SI 1.000
30
5
5
$15414
-U.200
S7JJ04
S9-.9U
Component
INDIRECT OPERATION AND MAINTENANCE COSTS
Administration (5% of Direct O4M)
Misc. Fees (5% of Direct O4M)
Reserve (25% of Direct O4M)
TOTAL INDIRECT MM PRESENT WORTH
TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
Worth
S4.*94
S24.472
SH.16I
SIJ2.I-I9
GRAND TOTAL
Sount: TtrruMuiru/SMI I99H
fJ.tSJ.411
-------
OP ALTERNAT1VES FOR GA^SUB.BASIN WASTB ROCK - WAMP CWTERIA
Surface Erosion Stability
Slope Stability
Flow Capacity and Stability
Surface Water and Ground Water
Contaminant Loading Reduction
"errestrial Ecosystem Exposure
Alternative 1
No Action
No erosionil stability measures would be
taken. Side slopes may not meet WAMP
criteria.
Not applicable lo existing slopes.
May not be stable during 100-year event.
No reduction in potential loading.
No change in potential risk to terrestrial
ecosystem.
Alternative 2
Diversion of Surface Wiler and Stream Channel
Reeon|lructlon
Diversion channels and stream channel reconstruction
will divert runon water away from the waste rock
reducing surface erosion.
Not applicable to existing slopes.
Diversion channels will be sized lo pass the 100-year (
event. Channel reconstructed to pass upstream (low and
remain stable for 500-year event.
Runon will be diverted around waste rock.
Any risk to the terrestrial ecosystem from the waste rock
would be reduced.
Not applicable.
Alternative 3
Diversion of Surface Water and
Selected Removal
Diversion channels will divert runon water away
from the waste rock. Removal will remove waste
rock from flood plain.
Retaining wall will be required to meet WAMP
criteria.
Diversion channels will be sized to pass the 100-
year event.
Runon will be diverted around waste rock.
Any risk to the terrestrial ecosystem from the waste
rock would be reduced.
Not applicable.
Source: TerraMatrix/SMI 1998
P:VJH(M)I3\OU4\NE\VROD\TBL-J» WPD 1/30/91
-------
TABLE39
COMPARISON OF ALTERNATIVES FOR THE PRINTER GIRL WASTE ROCK -
WAMP CRITERIA
Surface Erosion
Stability
Slope Stability
How Capacity and
Stability
Surface Water (SW)
ind Groundwater
GW) Contaminant
x>ading Reduction
'errestrial Ecosystem
Exposure
^on-Residential Soils
Alternative 1
No Action
No change in
existing erosionaJ
stability; criteria do
not apply.
Notapplicable^no
remediation would
occur.
No change in
existing flow
capacity and
stability; criteria do
not apply.
No reduction in
potential loading.
No change in
potential risk to
terrestial ecosystem.
Not applicable.
Alternative 2
Stream Channel
Reconstruction
Surface erosion of waste
rock would continue.
Not applicable, no
remediation would occur.
Waste rock would be
stabilized for the 100-
year flood event in
Whites Gulch.
Reduces erosion and
leaching associated with
stream channel contact
with. waste rock.
Any risk to the terrestrial
ecosystem from the waste
rock would be reduced.
Not applicable.
Alternative 3
Stream Channel
Reconstruction and
Reeradine
Surface erosion of waste
rock would be reduced.
Would improve slope
stability of waste rock.
Waste rock would be
stabilized for the 100-year
flood event in Whites
Gulch.
Reduces erosion and
leaching associated with
stream channel contact
with waste rock.
Any risk to the terrestrial
ecosystem from the waste
rock would be reduced.
Not applicable.
Alternative 4
Waste Rock Removal
Would eliminate waste
rock as an erosional
source.
Would eliminate waste
rock stability as an issue.
Would remove waste
rock from contact with
surface water.
Eliminates waste rock as
a source of
contamination.
Any risk to the terrestrial
ecosystem from the
waste rock would be
eliminated.
No^appjicable.'
Source: TerraMatrix/SMI 1998
P:U2SO-OI3\OU4\NEWRODVnJLO9.WPD
-------
TABLE 40
COMPARISON OF ALTERNATIVES FOR THE
NUGGET GULCH WASTE ROCK - WAMP CRITERIA
Surface Erosion
Stability
Slope Stability
:low Capacity and
Stability
Surface Water (SW) and
Croundwater (CW)
'ontaminant Loading
(eduction
'errestrial Ecosystem
exposure
Non-Residential Soils
Alternative 1
No Action
No change in existing
erosionaJ stability; criteria
do not apply.
Not applicable, no
remediation would occur.
No change in existing
flow capacity and
stability; criteria do not
apply.
^o reduction in potential
oading.
>fo change in potential
risk lo terrestial
ecosystem.
Not applicable.
Alternative 2
Diversion Ditches
Diversion channels will
divert surface runon awiy
from waste rock, reducing
surface erosion!
Not applicable, no
remediation would occur.
Diversion channels will be
designed to pass the 1 00-
year flood event.
Diversion channels will
prevent runon water from
contacting the waste rock,
thus decreasing the loading
to surface water.
Any risk to the terrestrial
ecosystem from the waste
rock would be reduced.
Not applicable.
Alternative 3
Diversion Ditches and
Waste Rock Recradine
Diversion channels will
divert surface runon away
from waste rock, reducing
surface erosion.
Regrading of waste rock will
improve stability.
Diversion channels will be
designed to pass the 1 00-
year flood event
Diversion channels will
prevent runon water from
contacting the waste rock.
thus decreasing the loading
10 surface water.
Any risk lo the terrestrial
ecosystem from the waste
rock would be reduced.
Not applicable.
Alternative 4
Diversion Ditches,
Consolidation, and Cover
Consolidation and covering
will reduce surface erosion.
Terraces and revcgeution will
stabilize disturbed areas.
Consolidation and regrading
of waste rock will improve
stability.
Diversion channels will be
designed to pass the 100-year
flood event
Diversion channels,
consolidation and cover
decreases surface area for
direct infiltration and loading
to surface water.
Any risk to the terrestrial
ecosystem from the waste rock
would-be eliminated.
Not applicable.
Source: TerraMatrix/SMI 1998
P.'J:JO-01 J'.OIWNE WRODVTDL-lO. WPD
-------
TABLE 41
COMPARISON OF ALTERNATIVES FOR THE AY-MINNIE WASTE ROCK -
WAMP CRITERIA
Surface Erosion
Stability
Slope Stability
low Capacity and
Stability
Surface Water (SW) and
Groundwater (CW)
Contaminant Loading
deduction
er rest rial Ecosystem
Exposure
Non-Residential Soils
Alternative 1
No Action
No change in existing
erosional stability;
criteria do not apply.
Not applicable, no
remediation would
occur.
Mo change in existing
flow capacity and
stability; criteria do not
apply.
*Jo reduction in potential
oading.
-Jo change in potential
risk to lerrestial
ecosystem.
Not applicable.
Alternative 2
Diversion Ditches
Diversion ditches will divert
surface runon away from
waste rock, reducing surface
erosion.
Not applicable, no
remediation would occur.
Diversion ditches will be
designed to pass the 100-year
flood event
Diversion ditches will prevent
runon water from contacting
the waste rock, thus
decreasing the loading to
surface water.
There would be little change
n potential risk to icrrcstial
ecosystem.
Not applicable.
Alternative 3
Diversion Ditches and
ReEradine
Diversion ditches will divert
surface runon away from
waste rock, reducing surface
erosion.
Stability of the slopes would
be improved removal of
cribbing and regrading.
Diversion ditches will be
designed to pass the 100-year
flood event.
Diversion ditches will prevent
runon water from contacting
the waste rock, thus
decreasing the loading to
surface water.
There would be little change
in potential risk to terrestial
ecosystem.
Not applicable.
Alternative 4
Diversion Ditches and
Road Reconstruction
Diversion ditches will divert
surface runon away from
waste rock, reducing surface
erosion.
The hazard presented by
failure of the cribbing would
be reduced by realignment of
county road.
Diversion ditches will be
designed to pass the 100-year
flood event.
Diversion ditches will
prevent runon water from
contacting the waste rock.
thus decreasing the loading
to surface water.
There would be little change
in potential risk to terrestial
ecosystem.
Not applicable.
Source: TerraMatru/SMl 1998
r.'J2JO-OIW>LMvNEWROD\TUL-II.WPD
-------
TABLE 42
COMPARISON OF ALTERNATIVES FOR THE IRON HILL WASTE ROCK -
WAMP CRITERIA
Surface Erosion
Stability
Slope Stability
•"low Capacity and
Stability
Surface Water (SW) and
Croundwater (GW)
Contaminant Loading
Reduction
'errejtrial Ecosystem
Exposure
Non-Residential Soils
Alternative 1
No Action
No change in existing
erosions! stability; criteria
do not apply.
Not applicable, no
remediation would occur.
No change in existing
flow capacity and
stability; criteria do not
apply-
No reduction in potential
loading.
•Jo change in potential
risk io terrestial
ecosystem.
Not applicable.
Alternative 2
Diversion Ditches
Diversion channels will
divert surface runon away
from waste rock, reducing
surface erosion.
Not applicable, no
remediation would occur.
Diversion channels will be
designed to pass the 100-
year flood event.
Diversion channels will
prevent runon water from
contacting the waste rock,
thus decreasing the loading
to surface water.
Jtlle change in potential
risk to terrestial ecosystem.
*Joi applicable.
Alternative 3
degrading and Cover
Regrading of one pile will
reduce slopes and erosion
potential. Covering of other
pile will eliminate erosion.
Regrading of slopes would
meet WAMP criteria.
Covered pile would be
stabilized for the 100-year
flood event.
One pile would be regraded
to reduce the amount of
infiltration caused by
ponding, the other pile
would be covered to reduce
leaching.
Risk to the terrestrial
ecosystem from the waste
rock would be reduced
through cover.
Mot applicable.
Alternative 4
Waste Rock Consolidation
Consolidation and covering
will eliminate surface erosion
releases.
Consolidated waste rock
would meet WAMP criteria.
Covered pile would be
stabilized for the 100-year
flood event.
Consolidation and covering I
decreases surface area for
direct infiltration and loading
to surface water.
By reducing contact surface.
risk to the terrestrial ecosystem •
from the waste rock would D<:
reduced. jj
Not applicable. Jj
ource: TerraMatrix/SMl 1998
-------
TABLE 43
COMPARISON OF ALTERNATIVES FOR THE
CALIFORNIA GULCH WASTE ROCK - WAMP CRITERIA
Surface Erosion
Stability
Slope Stability
:low Capacity and
Stability
Surface Water (SW) and
Croundwater (CW)
Contaminant Loading
Reduction
'errestrial Ecosystem
Exposure
Non-Residential Soils
Alternative 1
No Action
No change in existing
erosional stability; criteria
do not apply.
Not applicable, no
remediation would occur
No change in existing
flow capacity and
stability; criteria do not
apply.
No reduction in potential
loading.
No change in potential
risk 10 terrestial
ecosystem.
Not applicable.
Alternative 2
Channel Reconstruction
Diversion channels will
divert surface runon away
from waste rock, reducing
surface erosion.
Not applicable, no
remediation would occur.
Diversion channels will be
designed to pass the 500-
year flood event.
Diversion channels will
prevent runon water from
contacting the waste rock,
thus decreasing the loading
to surface water.
Little change in potential
risk to terrestial ecosystem.
Not applicable.
Alternative 3
Selected Ref rading
Rcgrading of slopes will
reduce slopes and erosion
potential.
Regrading of slopes would
meet WAMP criteria.
May noi be stable during the
500-year flood event.
Regrading reduces the
amount of infiltration caused
by ponding.
Little change in potential
risk to lerrestial ecosystem.
Not applicable.
Alternative 4
Selected Waste Rock
Removal
Would eliminate waste rock as
an erosional source of
contamination.
Would eliminate waste rock
stability as an issue.
Would remove waste rock
from contact with surface
water.
Eliminates waste rock as a
source of contamination.
Any risk to the terrestrial
ecosystem from the waste rock
would be eliminated.
Not applicable.
Source: TerraMatrix/SMI 1998
P.'J 380-013\OUJ\NEWROD\TDL-I3.WPD
-------
TABLE 44
COMPARISON OF ALTERNATIVES FOR FLUVIAL TAILING SITE 4 - WAMP CRITERIA
Surface Erosion Stability
Slope Stability
Flow Capacity and Stability
Surface Water (S\V) ind
Groundwater(GW)
HContaminanl Loading
[(Reduction
||rerreslrlil Ecosystem
(Exposure
Alternative 1
No Action
No change in existing
erosional stability; criteria
do not apply.
Not applicable, no
remediation would occur.
No change in existing flow
capacity and stability;
criteria do not apply.
No reduction in potential
loading.
No change in potential risk
to terreslial ecosystem.
Not applicable
Alternative 2
Channel Reconstruction and
Revegefalion
Establishment of a vegetated
surface will increase stability.
Due to its flat topography.
slope stability is not an issue.
Reconstruction of the upper
California Gulch channel and
floodplain will have capacity
to pass 500-year flood event.
Loadings would be reduced by
limiting contact of water with
waste material and increased
erosional stability.
Potential risk to terrestrial
ecosystem would be reduced.
Not annlicable.
Alternative 3
Channel Reconstruction,
Sediment Dams and
Wetlands
Sediment discharge would
be reduced through
construction of sediment
dams and wetlands.
Due to its flat topography,
slope stability is not an
issue.
Reconstruction of the upper
California Gulch channel
and floodplain will have
capacity to pass 500-year
flood event.
Loadings would be reduced
by limiting contact of water
with waste material and
increased erosional stability.
Potential risk to terrestrial
ecosystem would be
reduced.
Not anolicable.
Alternative 4
Channel Reconstruction,
Revegetatlon,Scdiment Dams
and Wetlands
Sediment discharge would be
reduced through construction of
sediment dams and wetlands.
Due to its flat topography, slope
stability is not an issue.
Reconstruction of the upper
California Gulch channel and
floodplain will have capacity to
pass 500-year flood event.
Loadings would be reduced by
limiting contact of water with
waste material and increased
erosional stability.
Potential risk to terrestrial
ecosystem would be reduced.
Not aoolicable.
Alternative 5
Channel Reconstruction,
Revegetatlon, Sediment Dams,
Wetlands and Selected Surface
Material Removal
Sediment generation and
discharge would be reduced due
to the revegelation of disturbed
area and the catchment of check
dams and wetlands.
Due to its flat topography, slope
stability is not an issue.
Reconstruction of the upper
California Gulch channel and
adjacent floodplain will have
capacity to pass the 500-year
event.
Loadings would be reduced by
limiting contact of water with
waste material and increased
erosional stability.
Potential risk to terrestrial
ecosystem would be reduced.
Not iDDlicable.
Source: TerroMatrix/SMt 1998
-------
APPENDIX A
ARARs
Record of Decision
Upper Clliforaia Gulch OU4
32698 P.U3KWIJ\OU4\NEWROD\RODOU4-2.W?D
-------
APPENDIX A
SUMMARY OF FEDERAL AND STATE ARARs
(Page 1 of 7)
Standard, Requirement
Criteria, or Limitation
FEDERAL ARARs,
Endangered Species Act
Fish and Wildlife Coordination Act
Wilderness Act
Executive Order NO. 11988
Floodplain Management
Executive Order NO. 11990
Protection of Wetlands
Section 404. Clean Water Act
(CWA)
Citation
16 USC$ 1531 cl sea.
50 CFR |§ 200 and 402
16 use } 661 el sea
40 CFRJ 6.302
16 USC 1311. 16 USC 668
50 CFR 53. 50 CFR 27
40 CFR 9 6.302 & Appendix A
40 CFR $ 6.302(a) and Appendix
A
33 USC 1251 eljsjj.
33 CFR Part 330
Potentially
Applicable
No
No
No
Yes
Yes
Yes
Potentially
Relevant and
A ppvnp^f ^tff
No
No
No
...
...
Description
Provides protection for threatened and endangered species
and their habitats. However, site-specific studies did not
document the presence of threatened or endangered species.
If threatened or endangered species are encountered during
remedial activities in OU4, then requirements of Act would
be applicable.
Requires coordination with federal and state agencies to
provide protection of fish and wildlife in water resource
development programs; regulates actions that impound,
divert, control, or modify any body of water. However.
proposed remedial action activities in OU4 will not affect
fish or wildlife. If it appears that remedial activities may
impact wildlife resources, EPA will coordinate with both
the U.S. Fish and Wildlife Service and the Colorado
Department of Natural Resources.
Limits activities within areas designated as wilderness areas
or National Wildlife Refuge Systems.
Pertains to tloodplain management and construction and
impoundments in such areas.
Minimizes adverse impacts on areas designated as
wetlands.
Regulates discharge of dredged or fill materials into waters
of the United Stales. Substantive requirements of portions
of Nationwide Permit No. 38 (General and Specific
Conditions) are applicable to OU4 remedial activities
conducted within waters of the United States.
Source: TerraMattii/SMI 1998
PA.12SO-OI 3\OU-I\NEWROD\APPDX-A.WPD
-------
APPENDIX A (CONTINUED)
SUMMARY OF FEDERAL AND STATE ARARs
(Page 2 of 7)
Standard, Requirement
Criteria, or Limitation
Hie Historic and Archaeological
Data Preservation Act of 1974
National Historic Preservation Act
(NHPA)
Executive Order 1 1593 Protection
and Enhancement of the Cultural
Environment
Historic Sites Act of 1935
The Archeological Resources
Protection Act ofl 979
Resource Conservation and
Recovery Act (RCRA). Subtitle D
Citation
16 USC 469
40 CFR J6.30IO
16USC}470cLS£fl
40 CFR§ 6.301 (b)
36 CFR Part 63. Part 65, Part 800
16 USC {470
16 USC §46 1- 467
16USC§§470aa-470ll
40CFRPart257.SubpartA.
§257.3-1 Floodplains. paragraph
(a)
Potentially
Applicable
Yes
Yes
Yes
No
No
Yes
Potentially
Relevant and
A a%n|*pntv4«fta)
...
No
Yes
...
Description
Establishes procedures to preserve historical and
archeological data that might be destroyed through
alteration of terrain as a result of a federal construction
project or a federally licensed activity program. A cultural
resource survey was completed in OU4 to identify historic
DroDcrties which may be affected bv removal activity.
Expands historic preservation programs; requires
preservation of resources included in or eligible for listing
on the National Register for Historic Places.
Directs federal agencies to institute procedures to ensure
programs contribute to the preservation and enhancement
of non-federally owned historic resource?. Consultation
with the Advisory Council on Historic Preservation is
required if remedial activities should threaten cultural
resources.
Preserves for public use historic sites, buildings, and
objects of natural significance.
Requires a permit for any excavation or removal of
archeological resources from public lands or Indian lands.
May be relevant and appropriate if archeological resources
are encountered during remedial action activity.
Provides general classification criteria for solid waste
disposal facilities pertaining to floodplains.
Source: TerraMatrix/SMI 1998
PA32MM)^BVNEWKOD\APPDX A WPD
-------
APPENDIX A (CONTINUED)
SUMMARY OF FEDERAL AND STATE ARARs
(Page 3 of 7)
Standard, Requirement
Criteria, or Limitation
Citation
Potentially
Applicable
Potentially
Relevant and
A nnrfttir4«l»
Description
Clean Air Act
National Primary and Secondary
Ambient Air Quality Standards
40CFRPart50
No
No
National ambient air quality standards (NAAQS) are
implemented through the New Source Review Program and
State Implementation Plans (SIPs). The federal New
Source Review program address only major sources.
Emissions associated with proposed remedial action in
OU4 will be limited to fugitive dust emissions associated
with earth moving activities during construction and will
occur in isolated areas over a short period of time.
Remedial work in OU4 will be completed in industrial
zoned areas significant distances from residential areas. In
addition, existing topography will further reduce the
potential for fugitive dust emissions. These remedial
activities will not constitute a major source. Therefore,
attainment and maintenance of NAAQS pursuant to the
New Source Review Program are not ARARs. See
Colorado Air Pollution Prevention and control Act
concerning applicability of requirements implemented
through the SIP.
RCRA Land Disposal Restrictions
(LDRs)
40 CFR Part 268
No
No
RCRA LDRs are not applicable because the materials in
issue have been identified as extraction of beneficiation
wastes that are specifically exempted from the definition of
a hazardous waste. Not relevant and appropriate, see
Superfund LDR Guide 07.
Solid Waste Disposal Act as
amended by the Resource
Conservation and Recovery Act of
1976 (RCRA)
40CFRPart257.SubpartA:J
257.3-1 Floodplains. paragraph
(a); 5 257.3-7 Air, paragraph (b)
Yes
Selected portion of Part 257 pertaining to floodplains and
air are applicable. These provisions establish criteria for
classification of solid waste disposal facilities and practices.
Hazardous Materials Transportation
Act
49 USC } 1801-1813
49 CFR 107,171-177
No
No
Regulates transportation of hazardous materials. Proposed
remedial action in OU4 will be conducted on private
property and will not entail off-site transportation of
hazardous materials.
Source: TerraMatrix/SMl 1998
p:Y12gf>OI)\OlM\NEWRODVArPDX-AWPD
-------
APPENDIX A (CONTINUED)
SUMMARY OF FEDERAL AND STATE ARARs
(Page 4 of 7)
Standard, Requirement
Criteria, or Limitation
STATE OF COLORADO ARARi
Nongame, Endangered or
Threatened Species Act
Colorado Register of Historic Places
Colorado Historical. Prehistorical.
and Archaeological Resources Act
Colorado Species of Special
Concern and Species of
Undetermined Status
Colorado Natural Areas
Colorado Solid Waste Disposal Sites
and Facilities Act. Colorado Revised
Statutes. Title 30. Article 20.
Sections 101-118
Citation
Potentially
Applicable
Potentially
Relevant and
^ nnrnnrf ttfjt
CRS§} 33-2- 101 lo 108
CRS 99 24-80.l-IOIIol08
CRS 99 24-80-401(0 4 10
1301 (o 1305
Colorado Division of Wildlife
Administrative Directive E-l.
1983. modified
Colorado Revised Statutes, Tide
33, Article 33. Sec. 104
f^'
6CCR 1007-2
6 CCR 1007-2. Parti
No
No
No
No
No
No
No
No
Yes
No
No
No
Description
Standards for regulation of nongame wildlife and
threatened and endangered species. Site-specific studies
did not document the presence of threatened or endangered
species. If threatened or endangered species are
encountered during remedial activities in OU4, ihen
requirements of Act will be applicable.
Authorizes the State Historical Society (o nominate
properties for inclusion on (he Slate Register of Historic
Places. Applicable only if remedial activities impact an
area listed on the Reeisler.
Concerns historical, prehistorical. and archaeological
resources; applies only to areas owned by the Slate or its
political subdivisions. May be relevant and appropriate if
remedial activities impact an archaeological site.
Protects species listed on the Colorado Division of Wildlife
generated list. Urges coordination with the Division of
Wildlife if wildlife species are lo be impacted. No evidence
of species of special concern have been identified at this
site.
Maintains a list of plant species of "special concern".
Although not protected by Slate statue, coordination with
Division of Parks and Outdoor Recreation is recommended
if activities will impact listed species.
Establishes regulations for solid waste management
facilities, including location standards. Proposed remedial
action in OU4 will not establish a solid waste management
facility.
Source: TerraMatrixSSMI 1998
p \i28a
-A WPD
-------
APPENDIX A (CONTINUED)
SUMMARY OF FEDERAL AND STATE ARARs
(Page 5 of 7)
Standard, Requirement
Criteria, or Limitation
Colorado Solid Waste Disposal Sites
and Facilities Act
Colorado Water Quality Control
Act. Storm Water Discharge
Regulations
Colorado Mined Land Reclamation
Act
Colorado Air Pollution Prevention
and Control Act
Colorado Air Pollution Prevention
and Control Act
Colorado Air Pollution Prevention
and Control Act
Citation
6 CCR 1007-2
5 CCR 1002-2
CRS 34-32- 101 to 125
Rule 3 or Mineral Rules and
Regulations
5 CCR 1001-3;
Sections III.D.I.b.c.d.
Sections III.D.2.b.c.e.f.
Regulation 1
5 CCR 1001-4
Regulation 2
Odors
5 CCR 1001-5
Reflation 3 APENs
Potentially
Applicable
No
Yes
No
Yes
Yes
Yes
Potentially
Relevant and
Annrrunrlaff
No
--•
Yes
...
'
Description
Establishes policy for licensing, locating, constructing and
operating solid waste facilities. Proposed remedial action
in OU4 will not involve establishment of a solid waste
disposal facility
Establishes requirements for storm water discharges (except
portions relating to Site-wide Surface and Groundwater).
Substantive requirements for storm water discharges
associated with construction activities are BDDlicable.
Regulates all aspects of land use for mining. Including the
location of mining operations and related reclamation
activities and other environmental and socio-economic
impacts. Substantive requirements of selected portions of
Rule 3 regarding Reclamation Measures, Water-General
Requirements (except portions relating to Site- wide Surface
and Groundwaler), Wildlife, and Revegetalion are relevant
and appropriate.
Regulation No. 1 provisions concerning fugitive emissions
for construction activities, storage and stockpiling
activities, haul roads, and haul trucks are applicable (5 CCR
1001-3; Sections III.D.2.b.c.e.Q. Construction activities in
OU4 will be conducted in accordance with a fugitive
emissions control plan.
Applicable only if remedial action activities cause
objectionable odors. Remedial action in OU4 is not
expected to produce odors.
Substantive provisions of APENs will be met.
Source: TcrraMatrix/SMI 1998
P:\.12»O.OIJVOIMVNEWRODVAPPDX-A WPD
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APPENDIX A (CONTINUED)
SUMMARY OF FEDERAL AND STATE ARARs
(Page 6 of 7)
Standard, Requirement
Criteria, or Limitation
Colorado Air Pollution Prevention
and Control Act
Colorado Noise Abatement Act
Citation
5 CCR 1001-14
5 CCR 1001-10
Part C(l)& (III)
Regulation 8
CRS §§25-12- 101 lo 108
Potentially
Applicable
Yes
Yes
Potentially
Relevant and
A pni>nfii>l«f •
„.
Description
Pursuant to the Colorado Air Pollution Prevention and
Control Act, applicants Tor construction permits are
required to evaluate whether the proposed source will
exceed NAAQS. Applicants are also required lo evaluate
whether the proposed activities would cause the Colorado
ambient standard for TCP to be exceeded. Remedial work
in OU4 will be completed in industrial zoned areas
significant distances from residential areas. In addition.
existing topography will further reduce the potential Tor
fugitive emissions through Regulation No. 1. Compliance
with applicable provisions of the Colorado air quality
requirements will be achieved by adhering lo a fugitive
emissions control plan prepared in accordance with
Regulation No. 1.
Regulation 8 sets emission limits for lead and hydrogen
sulfide. Applicants are required lo evaluate whether (he
proposed activities would result in the Regulation 8 lead
standard being exceeded. The proposed remedial action in
OU4 is not projected to exceed the emission levels for lead
or hydrogen sulfide, although some lead emissions may
occur. Compliance with Regulation 8 will be achieved by
adhering to a fugitive emissions control plan prepared in
accordance with Regulation No. 1 .
Establishes maximum permissible noise levels for particular
time periods and land use related lo construction projects.
Remedial work In OU4 will be completed in industrial
zoned areas a significant distance from residential areas. In
addition, the existing topography will reduce noise
emission levels.
Source: TerraMatrix/SMI 1998
-------
APPENDIX A (CONTINUED)
SUMMARY OF FEDERAL AND STATE ARARs
(Page 7 of 7)
Standard, Requirement
Criteria, or Limitation
Regulations on the Collection of
Aquatic Life
Colorado Hazardous Waste
Regulations
Citation
2 CCR 406-8, Ch. 13.
Article Ml. Sec. 1316
6 CCR 1007-3. Part 264: Section
264.301. (f).(h).(i). and (j);
Section 264.3 10. (a) (1 ) through
(a) (4);
Section 264.3 10. (b)(l) and
(b)(5)
Potentially
Applicable
No
No
Potentially
Relevant and
A nni»tfMtrl*t *
No
Yes
Description
Requirements governing the collection of wildlife for
scientific purposes. Remedial activities within OU4 will
not include biological monitoring.
These specific provisions of the hazardous waste
regulations may be relevant and appropriate In certain
circumstances depending on site specific conditions in
OU4. The determination of whether such requirements will
be both relevant and appropriate to the activities to be
undertaken in OU4 will be based on best professional
judgement and is conducted on a site specific basis taking
into account the physical nature and location of the media
involved, whether the requirements are well suited for the
site conditions, and other factors.
Source: TerraMatrix/SMI 1998
P:VJ280-OIJ>OIM\NEWROD\APPDX-A.WPD
------- |