EPA Superfund Record of Decision: California Gulch EPA ID: COD980717938 OU 04 Leadville, CO


                                    EPA/ROD/R08-98/077
                                    1998
EPA Superfund
     Record of Decision:
     CALIFORNIA GULCH
     EPA ID: COD980717938
     OU04
     LEADVILLE, CO
     03/31/1998

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EPA-541-R98-077

                                                      ADMINISTRATIVE RECORD
                                 COPY
                                 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 reguirements of the
    Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.C. 9601 et seg., 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 reguirements 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 reguirements; and

The Responsiveness Summary section addresses public comments received on the Proposed Plan, the RI/FS,
and other information in the Administrative Record.

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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 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.

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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 waste 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 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
reguirements 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 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 adeguate
protection of human health and the environment. These remedies are acceptable to both the State of
Colorado and the community of Leadville.

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                           TABIiE OF CONTENTS

SECTION                                                                        PAGE


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
      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

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      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
             WAMP PERFORMANCE CRITERIA	 DS-52
             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
             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

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

                          LIST OF TABLES
TABLE

1    SUB-BASINS AND CONTAMINATED WASTE ROCK PILES  -  OU4
2    GARIBALDI SUB-BASIN WASTE ROCK GEOCHEMICAL DATA
3    SURFACE WATER COG LOADINGS
4    GEOCHEMICAL DATA FOR WASTE ROCK SOURCES IN WHITES GULCH 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
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

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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

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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
WAMP
WCC
WWL
Acid-Base Accounting
Above Mean Sea Level
Administrative Order on Consent
Acid Rock Drainage
Ambient Water Quality Criteria
Baseline Aguatic 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 Eguation
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
Work Area Management Plan
Woodward-Clyde Consultants
Water, Waste, and Land, Inc.

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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 gaid 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 sguare 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;

• 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.

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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).

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 sguare 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.

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

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installation and monitoring, and groundwater sampling and analysis. Objectives of the study were to
investigate groundwater guality and flow directions, evaluate potential impacts to water users and
surface water receptors, and to characterize background groundwater guality. 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 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 unigue identification number (e.g. UCG-#). Each pile was seguentially 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.

Sampling in Upper California Gulch included four groundwater monitoring wells and 28 surface water
sampling sites.

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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 reguest 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/North Mike;  and
       •      Mine waste  rock piles located near the Minnie  pump shaft.

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:            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 Material Removal

                        3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION

Public participation is reguired by CERCLA Sections 113 and 117. These sections reguire 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

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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 reguired community participation activities through the presentation of the RI/FS
and the Proposed Plan, a 30-day public comment period, a formal public hearing, and the presentation of
the Selected Remedy in this 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
RI/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 15 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 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.

                                    4.0 SCOPE AND ROLE OF OPERAKLE  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/Raiiroad 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
          OU11 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;

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       •       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

       •       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) .

                                    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.

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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.

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 (UCG-109A and -116)

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 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.

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5.2.1.3 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 (COG) loadings detected at sampling station CG-1G. Prior to 1996, surface
water COG 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 COG 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 COG 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 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

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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 Agwalt waste rock pile is primarily coarse to
fine-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).

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 COG Loadings. The COG
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 headwall catchment (AG-2E) was a major
contributor of COG loadings to Whites Gulch during 1995 and 1996, particularly for cadmium and copper.
Flow from the north headwall 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 COG
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 COG loadings detected at WG-1 (TerraMatrix/SMI, 1998).

Seepage from the Agwalt waste rock pile appears to be a major contributor to COG 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 waste rock pile as two seeps.
Monitoring station AG-1A 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-1B 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.

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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).

5.2.3 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).

5.2.3.1 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 (SMI/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 (Imhos/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 Imhos/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 values of 3.8 s.u. and 2.1 s.u., respectively. Paste
conductivity measurements were recorded at 13,300 Imhos/cm and 14,600 Imhos/cm, respectively.

The waste rock at the North and Moyer (UCG-79) 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

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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.

5.2.3.2 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 COG 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

• headwater catchment, east and upgradient of the North Moyer waste rock pile, monitored at
surface water sampling location NG-3.

Water guality at each of the surface water monitoring stations was compared against water guality 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 loud 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 guality parameters, including pH and
specific conductivity were only measured at surface water monitoring site NG-5A, located immediately
downgradient of UCG-76. The field pH of 2.69 s.u. and conductivity measurement of 2,200 Imhos/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. Conseguently, the peak flow COG loadings from NG-5
generally accounted for less than five percent of the associated loadings at NG-1 (TerraMatrix/SMI,
1998).

The water guality 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 COG loadings in Nugget Gulch. Surface water
monitoring stations NG-4A and NG-4B arc 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.

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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; 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 COG loadings at NG-2 generally accounted for 50 to 60 percent of the
corresponding COG 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 corner of the Nugget Gulch
Sub-basin (Figure 6). Quarterly bedrock groundwater sampling results indicate that this well is
uncontaminated (Golder, 1996b). Although there are no alluvial monitoring wells located in the Nugget
Gulch Sub-basin, COG 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.

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, 1994a). 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 cast 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.

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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 1995 and
1996. 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, 1998). 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.

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 COG 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 COG 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,
COG 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.

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

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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.

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 in 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

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(SMI/Terra.Matrix, 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.

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 guality 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 COG Loadings. The COG 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-1E, located downstream of the AY-Minnie mine site and
approximately 1,700 feet upstream of CG-1.

Water guality 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 guality 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-1D spring flow average TSS loading accounts for 24 percent of the spring flow TSS loading detected at
CG-1. The sulfate load at CG-1D represents 64 percent of the sulfate load at CG-1. Spring flow average
loadings of cadmium at CG-1D represents 31 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
CG-1D 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 guality samples have been collected five times at CG-1E between June 1989 and July 1996. The spring
flow measured at CG-1E 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

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approximately 90 percent of the spring flow average sulfate load at CG-1. Spring flow loadings of cadmium
at CG-1E 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-1G;
• 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 guality at the tributary catchment outlets were compared to water guality at CG-1. The COG
loadings from each tributary catchment outlets was compared to the water guality at CG-1.

A comparison of pre-removal action and post-removal action water guality data indicate that the Garibaldi
removal action resulted in an improvement in water guality 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 COG loadings
from Nugget Gulch generally account 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 appear to contribute to OU4 COG loadings
(TerraMatrix/SMI, 1998).

5.2.6.3 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 guality at the three springs was compared
against the water guality at CG-1.

In general, the COG concentrations detected from the three springs are less than the COG 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-1G, 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.

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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
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.

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.

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.

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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 o 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 guickly 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 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

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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.

6.1.3 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 1995a). 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. 1995b. Final Baseline Aguatic 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 aguatic 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 eguivalent 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 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 aguatic 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, stag, 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,

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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.

EXPOSURE ASSESSMENT
The EARA (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 aguatic 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 guantitatively.

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.

The EARA 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 EARA 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 EARA 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

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receptors.

Hazard Indices for Receptors Exposed to All Solid Surficial Media in OU4

Blue Mountain American Red-tailed Bald Least Mule Red
Grouse Bluebird Kestrel Hawk Eagle Chipmunk Deer Fox

12 296 8 4 5 20 1 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 guality 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 aguatic and terrestrial ecological receptors.

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 reguired by the NCP and six additional performance criteria reguired 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 (UCG-121)

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 1
Implementation time: Immediate

No remediation would take place under this alternative. This is the "no action" alternative reguired
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
1 Incidental administrative costs are incurred under the No Action Alternative

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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.

7.2    GARIBALDI SUB-BASIN WASTE ROCK  (UCG-109A)

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 reguired
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:

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       •      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: $138,413
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;
       •      Selected removal of approximately 1,000 cubic yards of waste  rock material and
              consolidation within OU4; and,
       •      Stabilization of removal area.

7.3    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 1
Implementation time: Immediate

No remediation would take place under this alternative. This is the "no action" alternative reguired
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 eguipment).

Aowalt 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:

       •      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 eguipment).
            1 Incidental administrative costs are incurred under the No Action Alternative

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Acrwalt 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 reguire improvements such as regrading and
              blading.

7.4    PRINTER GIRL (UCG-92A)

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: $0 1
Implementation time: Immediate

No remediation would take place under this alternative. This is the "no action" alternative reguired
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

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 reguire 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 reguire minor blading.
       1 Incidental administrative costs are incurred under the No Action Alternative

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7.5    NUGGET GULCH (UCG-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:

Nugget Gulch Alternative 1 - No Action
Estimated capital and operating cost: $0 1
Implementation time: Immediate

No remediation would take place under this alternative.  This is the "no action" alternative reguired
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 reguired.

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

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 (UCG-81)

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:
       1 Incidental administrative costs are incurred under the No Action Alternative

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AY-Minnie Alternative 1 - No Action
Estimated capital and operating cost: $0 1
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:

       •      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 1
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
runon 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).
       1 Incidental administrative costs are incurred under the No Action Alternative

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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  (UCG-33A, -65, -75, -82A, -93, -95 AND - 98)

The remaining waste rock piles in Upper California Gulch reguiring 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 1
Implementation time: Immediate

No remediation would take place under this alternative. This is the "no action" alternative reguired
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:
       1 administrative costs are incurred under the No Action Alternative

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       •       Removal  and haulage of selected waste rock (~15,000 cy);  and,
       •       Amendment and revegetation of disturbed area (3.7  acres).

7.9    FLUVIAL TAILING  (SITE 4)

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 1
Implementation time: Immediate

No remediation would take place under this alternative. This is the "no action" alternative reguired
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;
       •       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
       1 Incidental administrative costs are incurred under the No Action Alternative

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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;
       •      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: $0 1
Implementation time: Immediate

                      8.0  SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

Section 300.430(e) (9) of the NCP reguires 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
reguirements  (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
   adeguate 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 ARAR addresses whether or not a remedy will comply with identified federal and suite
   environmental and siting laws and regulations.

8.1.2  PRIMARY BALANCING CRITERIA

3. Long-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.
       1 Incidental administrative costs are incurred under the No Action Alternative

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7. Cost evaluates the estimates capital costs, operation and maintenance (O&M) costs, and present worth
costs of each alternative.

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 arc 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 stability.

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.

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 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

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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 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 freguency and duration of contact with contaminated media, such as: (1) the concentrations
and areal 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.

8.3 EVALUATING THE ALTERNATIVES WITH THE NCP CRITERIA

A comparative analysis of the Garibaldi and Agwalt mine site removal action alternatives were performed
in the EE/CAs (TerraMatrix/SMI, 1995a and 1996a) and subseguently 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.

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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 alternative 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)

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 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.

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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.

8.3.2 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 Gulch 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.

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

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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 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
guantity 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 revegetation (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 technigues for dust abatement (site watering) and traffic control.

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 dining 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 eguipment 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

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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.

8.3.6 IMPLEMENTABILITY

This criterion is based on the ability to perform construction and implement administrative actions.

Garibaldi Sub-basin Waste 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

AY-Minnie Waste Rock

Iron Hill Waste Rock

California Gulch Waste Rock

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.

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8.3.7 COST

This criterion evaluates the estimated capital, O&M and present worth costs of each alternative.

Garibaldi 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.

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 3299,026 (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 Roe

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.

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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.

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.

Alternative 3: 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 she 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.

Alternative 4: Selected Waste Rock 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.

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          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 32,653,493. Estimated cost details are
          summarized in Table 37.

8.3.8  STATE ACCEPTANCE

The State has been consulted throughout this process and concurs with the Selected Remedies.

8.3.9  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 guestions posed during the 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, 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. 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.

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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 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.

Garibaldi Sub-basin Waste Rock

In order to meet WAMP criteria for slope stability (Alternatives 2 and 3) a retaining wall would be
reguired 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.

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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.

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.

8.4.3 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
adeguately 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 COG 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 COG 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 COG
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 COG 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 COG 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 COG 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 COG
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.

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 COG 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 COG 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 COG 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 COG 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.

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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 COG 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

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.

Fluvial 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.

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 reguirements, 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.

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 reguirements 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.

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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).

9.1.3 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 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.

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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.

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 COG 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 COG 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 Ditch 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 COG 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 COG loading reduction to surface water 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 COG 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 far 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 reguired shall be responsible for such additional source remediation
(USCD, 1994).

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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 reguires 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:

                  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 a 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 eguivalent extent. Because the waste rock and fluvial tailing materials will remain
on site with no treatment, the Selected Remedies will reguire 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.

                              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:

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       •       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.

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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, and Agwalt 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-Hydrogeologic 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. Rockfill 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).

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 Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1995d. Draft - Operable Units 4, 8, and 10
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 Inc./Shepherd Miller, Inc. (TerraMatrix/SMI). 1996c. Removal Action Work Plan Engineering
Evaluation/Cost Analysis for Agwalt Mine Site Within Upper California Gulch Operable Unit 4.

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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.

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 Aguatic Ecological Risk Assessment, California Gulch NPL Site (BARA).

Weston. 1997. Ecological Risk Assessment for the Terrestrial Ecosystem, California Gulch NPL Site,
Leadville, Colorado (ERA).

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.

-------
                                           FIGURES

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                           RESPONSIVENESS SUMMARY

                             TABIiE 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

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 Superfund 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

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:           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

A portion of the public meeting held on January 29, 1998 was dedicated to accepting formal oral comments
from the public.

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:  What are fluvial tailings?

Response:       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.

Comment No. 2: Will work near the AY-Minnie have an effect on the Mineral Belt Bicycle Trail?

Response: 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.

Comment No 3: Where will fluvial tailings be deposited?

Response: The fluvial tailings will be deposited either at the Colorado #2 site (UCG-71) or used
near the gulch during regrading of the area.

Comment No. 4: How will air quality be addressed during remedial action?

Response: 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.

Comment No. 5: How will the bidding process work?

Response: Resurrection will contract the work to an environmental engineering

Comment No. 6: Will there be any plugging of shafts?

Response: 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?

Response: will be developed in the long-term monitoring plan. The sediment loading into the
sediment traps will be evaluated for future land use.

Comment No. 8: What is a simple cover?

Response: The proposed plan indicates that a simple cover will consist of 18 inches of low
permeable earthen material.

Comment No. 9: How will long-term maintenance be considered?

Response: 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. 10. 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-Y
Minnie.

Response: The specifications for the road relocation will be addressed during design. Interested
parties will be able to offer input during the design process.

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.

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                           TABIiE  1
       SUBBASINS AND CONTAMINATED WASTE  ROCK PIIiES OU4
Sub-Basin
Garibald:
Whites Gulch
Nugget Gulch
Waste Rock Pile
                          Surface Area(acres)
                                                                                                 Volume  (cy)
AY-Minnie
Iron Hill
Fluvial Tailing Site 4 and  South Area
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 Shaft)
UCG-82A
UCG-93
UCG-95
UCG-98 (Lower Printer Boy)
TOTAL
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
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

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                                 TABIiE 2
                 GARIBALDI SUB-BASIN WASTE ROCK GEOCHEMICAL DATA 1
    ABA Analysis
    Sulfur, SO 4  (%)
    Sulfur, Pyrite & Organic(%)
    Sulfur, Total  (%)
    AGP  (T/KT)
    Neutralizing Potential  (% CaCO 3)
    ANP  (T/KT)
    NNP  (T/KT)

    EPA Method 1312 Extracted
    Leachate 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
    0.0015
     0.034
     19.11
      10.3
      4.59
      5.05
    <0.0002
      1.78
      2.58
      6.24
    2.9 s.u.
       2
      254
       1
      345
      115
     0.61
    3,570
      382
          Waste Rock Pile
              UCG-116

                0.43
                0.32
                0.68
                 21
                0.1
                 <1
                -21

Concentration  (mg/1 unless noted)
               <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

        Concentration  (mg/kg)

                  30
                 6.5
                 446
                 518
Waste Rock Pile
    UCG-109A

      0.18
      1.15
      1.33
       42
       0.8
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/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
      0.022
      0.007
       19.7
       3.25
       <0.2
        3.6
        na
        1.8
        1.2
       3.80
     1.7 s.u.
        3
       170
        <1
        80
        46
       6.8
      4.63
     1,510

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                                   TABLE  3

                     SURFACE WATER COC LOADINGS  (Ibs/day)

                              Sample  ID
                                                             Flow (els)
                                                                                                                                Cd,  diss
          FLUVIAL SITE 4 and SOUTH AREA  SUB-BASIN

          1995 Peak Flow
          1996 Peak Flow
          spring flow average
          1995/1996 spring flow average
          pre-removal action spring  flow average
          post-removal action spring  flow average

          1995 Peak Flow
          1996 Peak Flow
          spring flow average
          1995/1996 spring flow average
          8 of 1995 Peak Flow at CG-1
          8 of 1996 Peak Flow at CG-1
          % of spring flow average at  CG-1
          % of 1995/1996 spring flow  average  at CG-1

          1995 Peak Flow
          1996 Peak Flow
          spring flow average
          1995/1996 spring flow average
          8 of 1995 Peak Flow at CG-1
          8 of 1996 Peak Flow at CG-1
          8 of spring flow average at  CG-1
          8 of 1995/1996 spring flow  average  CG-1
          1995 Peak Flow
          1996 Peak Flow
          spring now average
          1995/1996 spring Flow average
          8 of 1995 Peak Flow at CG-1
          8 of 1996 Peak Flow at CG-1
          8 of spring flow average at  CG-1
          8 of 1995/1996 spring flow  average  CG-1
RIBALDI SUB-BASIN
          CG-1G 1995 Peak Flow
          1996 Peak Flow
          pre-removal action spring  flow  average
          post-removal action spring  flow average
          1995/1996 spring flow average
          8 of 1995 Peak Flow at CG-1

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                              TABLE 3(Continued)


                   SURFACE  WATER COC LOADINGS (Ibs/day)

                               Sample ID

          8 of 1996  Peak  Flow at CG-1
          % of pre-removal  action spring flow average CG-1
          % of post-removal action spring flow average at CG-1
          % of 1995/1996  spring  flow average at CG-1

          1995 Peak  Flow
          1996 Peak  Flow
          pre-removal  action spring flow average
          post-removal  action spring flow average
          8 of 1995  Peak  Flow at CG-1G
          8 of 1996  Peak  Flow at CG-1G
          % of pre-removal  action spring now average at CG-1G
          % of post-removal action spring flow average at CG-1G

          1995 Peak  Flow
          1996 Peak  Flow
          pre-removal  action spring flow average
          post-removal  action spring flow average
          8 of 1995  Peak  Flow at CG-1G
          8 of 1996  Peak  Flow at CG-1G
          8 of pre-removal  action spring flow average CG-1G
          8 of post-removal action spring flow average CG-1(

          1995 Peak  Flow
          1996 Peak  Flow
          8 of 1995/1996  spring  flow average
          8 of 1995  Peak  Flow at CG-1G
          8 of 1996  Peak  Flow at CG-1G
          8 of 1995/1996  spring  flow average CG-1G

          1995 Peak  Flow
          1996 Peak  Flow
          8 of 1995  Peak  Flow at CG-1G
          8 of 1996  Peak  Flow at CG-1G
          1995 Peak  Flow
          1996 Peak  Flow
          8 of 1995  Peak  Flow at  CG-1G
          8 of 1996  Peak  Flow at  CG-1G
          1995 Peak  Flow
          1996 Peak  Flow
          8 of 1995  Peak  Flow at  CG-1G
          8 of 1996  peak  Flow at  CG-1G
WHITES GULCH SUB-BASIN
Cu,  diss
                                                       Zn,  diss
                                                                      Zn, total

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                   TABLE 3  (Continued)
                    Sample  ID
                                                                                                                          Zd, dis
                                                                                                                                       Cd, total
                                                                                                                                                                   Cu,  total
                                                                                                                                                                                 Pb,  diss
                                                                                                                                                                                               Pb, total
                                                                                                                                                                                                                 diss   Zn,  total
1996 Peak Flow
spring flow average
base f1ow av e r a ge
1995/1996 spring flow average
% of 1995 Peak Flow at CG-1
% of 1996 Peak Flow at CG-1
% of spring now average at CG-1
% 1995/1996 of flow average  at CG-1
1995 Peak Flow
1996 Peak Flow
spring flow average
base f1ow av e r a ge
1995/1996 spring flow average
% of 1995 Peak Flow at WG-1
% of 1996 Peak Flow at WG-1
% of spring flow average at WG-1
% of base flow average at WG-1
% of 1995/1996 spring flow average  at  WG-1
1995 Peak Flow
1996 Peak Flow
spring flow average
base f1ow av e r a ge
1995/1996 spring flow average
% of 1995 Peak Flow at WG-1
% of 1996 Peak Flow at WG-1
% of spring flow average at WG-1
% of base flow average at WG-1
% of 1995/1996 spring flow average  at  WG-1
1995 Peak Flow
1996 Peak Flow
spring flow average
base f1ow av e r a ge
1995/1996 spring flow average
% of 1995 Peak Flow at WG-1
% of 1996 Peak Flow at WG-1
% of spring flow average at WG-1
% of base flow average at WG-1
% of 1995/1996 spring flow average  at  WG-1
1995 Peak Flow
1996 Peak Flow
sprig flow average
base f1ow av e r a ge
1995/1996 spring flow average
% of 199S Peak Flow at WG-1

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                                      TABLE 4
           GEOCHEMICAL DATA FOR WASTE ROCK SOURCES IN WHITES GULCH 1
Sulfur, SO 4(8)
Sulfur, Pyrite & Organic  (8)
Sulfur, Total  (8)
AGP  (T/KT)
Neutralizing Potential  (8CaCO 3)
ANP  (T/KT)
NNP  (T/KT)
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
pH  (units)
Alkalinity  (ing/I as  CaCO  3)
TDS
Chloride
Sulfate
<





<0



3.


0.001
0.003
6.6
0.066
<0. 02
1. 88
.0002
1.85
2. 02
0.571
8 s.u.
<2
56
<0. 001
<0. 003
0.8
2.53
1.59
0.48
<0.0002
2.08
2.2
0.325
3.2 s.u
2
62
          1.   Source:  Draft-Operable Units 4,  8,  and 10 Reconnaissance  Report  (TerraMatrix/SMI.  1995d).
          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  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
Source:  TerraMatrix/SMI  1998

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                                       TABLE 5
                       GEOCHEMICAL DATA FOR WASTE ROCK IN THE
                        NUGGET  GULCH AND AY-MINNIE SUB-BASINS
ABA Analysis
Sulfur, SO 4  (%)
Sulfur, Pyrite  S Organic  (%)
Sulfur, Total  (%)
AGP  (T/KT)
Nuet. Potential  (% CaCO 3)
ANP  (T/KT)
NNP  (T/KT)
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
<0.001
0.009
117
0.017
<0.02
15.3
<0. 0002
0.477
1.49
0.123
6.3 s.u.
35
564
 <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
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/1   =  milligram per liter
          mg/kg  =  milligram per kilogram
          s.u.   =  standard  units
          "<"    =  indicates that  the  value  is less than the instrument detection  limit.

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                                  TABLE 6
                WASTE ROCK  PILE UCG-12 GEOCHEMICAL DATA 1
ABA Analysis

Sulfur, SO 4  (%)
Sulfur, Pyrite  & Organic(%)
Sulfur, Total  (%)
AGP (T/KT)
Neut.   Potential  (% CaCO 3)
ANP (T/KT)
NNP (T/KT)
Arsenic
Cadmium
Calcium
Iron
Lead
Magnesium
Mercury
Potassium
Sodium
Zinc
pH  (units)
Alkalinity  (mg/1 as  CaCO  3)
TDS
Chloride
Sulfate
             Acid generation  potential
             Acid neutralization  potential
             Net neutralization potential
             Tons per  1,000 tons
             milligram per  liter
             milligram per  kilogram
             standard  units
             indicates the  value  is less than the instrument detection limit.
Source:  TerraMatrix/SMI  1998

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                                                                                            TABLE 7
                                                               FLUVIAL TAILING  SITE  4  -  FLUVIAL TAILING GEOCHEMISTRY DATA
Composite 5
    F4B1
    F4B1
    F4B2
    F4B2
    F4B3
    F4B3
    F4B4
    F4B4
    F4B5
    F4B5
                 Depth  Interval
                                                                                                   EPA Method 1312 Leachate Analysis  2
                                                        487
                                                                                                               NM
                                                                                                               NM
                                                                                                               NM
                                                                                                               NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
Notes:  1) Total 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  RI (WCC,  1994a).
        5) Composite sample:  10  surface samples (0-2 inches) were collected  and  composited as a single sample as described  in  the
           Tailing RI  (WCC,  1994a).
        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  (Stoller,  1996).
"-" - indicates that the  reported value is below the instrument detection  limit.
NM - Not measured.
NR - Not reported.

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                                                TABLE 8
                          GEOCHEMICAL  DATA FOR WASTE ROCK SOURCES SAMPLED  IN
                                    FLUVIAL SITE 4 AND SOUTH AREA 1
 Sulfur, SO 4(8)
 Sulfur, Pyrite & Organic(8)
 Sulfur, Total  (8)
 AGP (T/KT)
 Neut.  Potential(8 CaCO 3)
 AN (T/KT)
 NNP (T/KT)

 EPA Method 1312 Extracted  Leachate  Analyses  (mg/1 unless noted)

 Arsenic                                      <0.001                      <0.001                     <0.001
 Cadmium                                       0.013                        0.342                     <0.003
 Calcium                                      40.8                       249                          1.9
 Iron                                         <0.01                         0.014                      3.21
 Lead                                         <0.02                         0.124                     <0.02
 Magnesium                                     8.87                       32.2                        0.542
 Mercury                                      <0.0002                     <0.0002                    <0.0002
 Potassium                                     1.52                         0.772                      0.866
 Sodium                                        0.492                        1.872                      1.932
 Zinc                                          0.058                      29.88                       0.039
 pH (units)                                    7.4 s.u.                     5.8 s.u.                   5.9 s.u.
 Alkalinity (mg/1 as CaCO 3)                  30                          25                          5
 TDS                                         200                        1330                         18
 Chloride                                     <1                          <1                         <1
 Sulfate                                     119                         878                          6
                Acid generalization  potential
                Acid neutralization  potential
                Net neutralization potential
                Tons per  1,000  tons
                milligram per liter
                milligram per kilogram
                standard  units
                indicates the value  is less  than the instrument detection limit.
Source: TerraMatrix/SMI  199E

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TABLE 10
COMPARISON OF ALTERNATIVES FOR THE
GARIBALDI SUB-BASIN WASTE ROCK - NCP CRITERIA
Alternative 1
No Action
Alternative 2
Diversion of Surface Water and
Stream Channel Reconstruction
Alternative 3
Diversion of Surface water and
Selected Removal
Compliance with ARARs
Long-Term Effectiveness and
Permanence
Implementability
Would not reduce the toxicity,
mobility, or volume of waste rock
and does not include treatment.

No disturbance to the community.
Not effective in reducing short-
term risk.
Involves diversion of surface and
portal flows minimizing leaching
and erosional 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
include 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
permits are not anticipated.
Cost 1
Source: TerraMatrlx/SMI 1998

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TABLE 11
COMPARISON OF ALTERNATIVES FOR THE PRINTER GIRL WASTE ROCK - NCP CRITERIA
Alternative 1
No Action
Alternative 4
Waste Rock Removal
Overall Protection of
Human Health and the
Environment
Reduces erosion and releases
to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Similar to Alternative 2 , except
regrading would help reduce
infiltration associated with
precipitation. Stability of pile
would increase.
Complies with all ARARs.

Minimizes leaching and
erosion associated with
stream flow but does not
prevent infiltration of
precipitation through the
waste rock.
Complies with all ARARs.

Similar to Alternative 2 except
infiltration would be reduced
and stability increased.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
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.
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.
No disturbance to the
community. Not
effective in reducing
short-term risk to the
environment.
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.
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.
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.
Not an issue.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Technologies are common
and widely accepted
Unusual permits are not
anticipated.
Cost 1
Source: TerraMatrix/SMI 1998
1 The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.

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TABLE 12
COMPARISON OF ALTERNATIVES FOR THE
NUGGET GULCH WASTE ROCK - NCP CRITERIA
Alternative 1
No Action
Not an issue.
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.
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 infiltration would be
greatly reduced and erosional
releases would be minimized.
Wind erosion would be
addressed through cover.
Long-Term
Effectiveness and
Permanence
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the
waste rock.
Similar to Alternative 2,
except erosional releases
would be minimized by
construction of simple cover
and revegetation.
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
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.
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 simple cover over
consolidated waste rock would
even further reduce leaching
and loading from the site.
No disturbance to the
community. Not effective
in reducing short-term risk
to the environment.
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.
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.
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.
Implementability
Not an issue.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Technologies are common and
widely accepted. Unusual
permits are not anticipated.
Cost 1 $0

Source: TerraMatrix/SMI 1998

-------
TABLE 13
COMPARISON OF ALTERNATIVES FOR THE AY-MINNIE - NCP CRITERIA
Alternative 1
No Action
Reduces erosion and releases
to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Similar to Alternative 2,
except regrading would help
reduce infiltration associated
with precipitation. Stability of
pile would increase.
Similar to Alternative 2,
except realignment of
County Road 2 adds further
protection to stability of
timber cribbing.
Not an issue.
Complies with all ARARs.
Complies with all ARARs.
Long-Term
Effectiveness and
Permanence
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the waste
rock.
Similar to Alternative 2,
except stability of timber
cribbing is addressed.
Would not reduce the
toxicity, mobility, or
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.
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.
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.
No disturbance to the
community. Not
effective in reducing
short-term risk to the
environment.
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.
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.
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.
Implementability
Not an issue.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Cost 1 $0

Source: TerraMatrix/SMI 1998

-------
TABLE 14
COMPARISON OF ALTERNATIVES FOR THE
IRON HILL WASTE ROCK - NCP CRITERIA
Alternative 1
No Action
Reduces erosion and
releases to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Regrading of one pile and
covering of the other pile
would help reduce
infiltration associated with
precipitation.
Infiltration would be greatly
reduced and erosional releases
would be minimized. Wind
erosion would be addressed
through cover.
Complies with all ARARs.
Complies with all ARARs.
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the
waste rock.
Erosional releases and
infiltration would be
minimized by regrading and
construction of simple cover.
Erosional releases and
infiltration would be further
minimized by consolidation
and construction of simple
c o v e r .
Would not reduce the
toxicity, mobility, or
volume of waste rock.
Does not include
treatment.
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.
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.
Similar to Alternative 3,
except simple cover over
consolidated waste rock would
even further reduce leaching
and loading from the site.
No disturbance to the
community. Not effective
in reducing short-term risk
to the environment.
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.
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.
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.
Implementability
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Cost 1 $0

Source: TerraMatrix/SMI 1998
$15
1 The No Action alternative will incur incidental costs related to the 5-year review, monitoring and administrative issues.

-------
TABLE 15
COMPARISON OF ALTERNATIVES FOR THE
CALIFORNIA GULCH WASTE ROCK - NCP CRITERIA
Alternative 1
No Action
Reduces erosion and
releases to surface water and
groundwater associated with
stream flow but not
precipitation. Does not
address wind erosion.
Regrading would help
reduce infiltration associated
with precipitation. Does not
address run-on or wind
erosion.
All RAOs would be achieved
by removing source at those
locations selected for removal.
Provides highest level of
protection.
Complies with all ARARs.
Complies with all ARARs.
Long-Term
Effectiveness and
Permanence
Minimizes leaching and
erosion associated with
stream flow but does not
prevent precipitation from
infiltrating through the
waste rock.
Erosional releases and
infiltration would be
minimized by regrading and
stability of piles would be
increased.
Reduces leaching and
erosional releases by removing
waste rock.
Would not reduce the
toxicity, mobility, or
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.
Surface exposed to water
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.
Reduces leaching and
erosional releases by removing
waste rock.
No disturbance to the
community. Not effective
in reducing short-term risk
to the environment.
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.
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.
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.
Implementability
Not an issue.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Technologies are common
and widely accepted.
Unusual permits are not
anticipated.
Cost 1 $0

Source: TerraMatrix/SMI 1998

-------
TABLE 16
COMPARISON OF ALTERNATIVES FOR FLUVIAL TAILING SITE 4 - NCP CRITERIA
Alternative 1
No Action
Alternative 2
Channel Reconstruction and
Revegetation
Alternative 3
Channel Reconstruction
Sediment Dams and Wetlands
Alternative 4
Channel Reconstruction
Revegetation, Sediment Dams
and Wetlands
Alternative 5
Channel Reconstruction
Revegetation, Sediment Dams
Wetlands, and Selected Surface
Material Removal
Reduces erosion and releases to
surface water and groundwater
associated with stream flow but
not precipitation. Does not address
wind erosion.
Reduces erosion and releases to
surface water and groundwater
associated with stream flow but
not precipitation. Does not
address wind erosion.
Alternative 5 combines the approaches
described for Alternative 2, 3 and 4
The channel of upper California Gulch
would be reconstructed, disturbed areas
amended as necessary and revegetated,
sediment control dams constructed and
wetlands constructed.
Compliance with
ARARs
Not an issue.
Complies with all ARARs.
Complies with all ARARs.
Complies with all ARARs.
Re.
Mobility, or Volume
the
Minimize 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 or contaminants from the
site would also be reduced.
unchanged and
Similar to Alternative 2 except
sediment dams reduce release of
sediment downstream.
be re
contaminants from the site
would be reduced. Toxicity is
unchanged and treatment is not
included.
reduced. Mobility _
contaminants from the site would
'city is
is not
included
Combines reductions described for
Alternatives 2, 3 and 4.
No disturbance to the
community. Not
effective in reducing
short-term risk to the
environment.
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.
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.
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.
Implementability
Not an issue.
Technologies are common and
widely accepted. Unusual permits
are not anticipated.
Technologies are common and
widely accepted. Unusual
permits are not anticipated.
Technologies are common and
widely accepted, except wetlands
would reguire studies. Permit
may be reguired for haulage.

-------
                                  TABIiE 17
         COST SUMMARY: GARIBALDI SUB-BASIN WASTE ROCK ALTERNATIVE 2  -
           SURFACE WATER DIVERSION, STREAM CHANNEL RECONSTRUCTION

California Gulch NPL Site
OU4 - FFS - UCG - 109A
Alternative 2 - Surface Water Diversion, Stream Channel Reconstruction

DIRECT CAPITAL COSTS
Component                   Unit

Channel Construction
              Rip Rap        cy
              Lined          sf
              Unlined        sf
              Culvert        If
Construct Access Road        If
Stream Reconstruction        If
Waste Rock Stabilization     If
Cultural Resources          lump
Dust Control                lump
Sediment Control            lump
      Unit  Cost
Quantity
                                Total Cost
                                       $6,300
                                      $19,125
                                      $ 2,850
                                       $1,500
                                       $1,575
                                      $13,125
                                       $3,500
                                       $5,000
                                       $2,000
                                       $2,000
TOTAL DIRECT CAPITAL COSTS
INDIRECT CAPITAL COSTS
                                                                                                    $56,975
Engineering and Design  (10% or Direct)
Contingency (25% of Direct)
Legal Fees  (5% of Direct)
Regulatory Cost  (5% of Direct)
Mobilization and Demobilization
EPA Fees  (20% of Engineering, 5

TOTAL INDIRECT CAPITAL COSTS
(20%  of  Direct)
 of Direct)
                    $5,698
                   $14,244
                    $2,849
                    $2,849
                   $11,395
                    $3,988
                                                                   $41,022
TOTAL CAPITAL COSTS
                                                                              $97,997

-------
POST REMEDIATION SITE CONTROL COSTS

           Discount            7.00% for present worth

Component          Unit
DIRECT OPERATION AND MAINTENANCE

Inspection         hour
Erosion Repair     lump
Vegetation Repair  lump

TOTAL DIRECT O&M PRESENT WORTH


Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH

hit
'CE

$2,


: Cost
$40
000
$0

Each
8
1
1

Each/year
4
1
1

$/year
$1,280
$2,000
$0

Years
30
5
5
Present
worth
$15,884
$8,200
$0
 $24,084

Present
 Worth
  $1,204
  $1,204
  $6,021

  $8,429
                                                                               GRAND  TOTAL
                     $32,513

                    $130,510
Source: TerraMatrix/SMI 1998

-------
                                            TABIiE 18
                   COST SUMMARY: GARIBALDI SUB-BASIN WASTE ROCK ALTERNATIVE  3
                           SURFACE WATER DIVERSION, SEIiECTED REMOVAL

California Gulch NPL Site
OU4 - FFS - UCG - 109A
Alternative 3 - Surface Water Diversion, Selected Removal

DIRECT CAPITAL COSTS
Component

Channel Construction
               Rip Rap
               Lined
               Unlined
               Culvert
Construct Access Road
Waste Rock Toe Stabilization
Waste Rock Removal
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS
                                    Unit
 cy
 sf
 sf
 If
 If
 If
 cy
lump
lump
lump
        Unit Cost
Quantity
                                                                     Total Cost
                 $2,520
                $19,125
                 $2,850
                 $1,500
                 $1,575
                $15,000
                $10,000
                 $5,000
                 $2,000
                 $2,000
                                                        $61,570
INDIRECT CAPITAL COSTS
Engineering and Design  (10% air 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
                                      $6,157
                                     $15,393
                                      $3,079
                                      $3,079
                                     $12,314
                                      $4,310
                                                        $44,330
TOTAL CAPITAL COSTS
                                                                       $105,900

-------
POST REMEDIATION SITE CONTROL COSTS
                   Discount    7.00% for present worth

                                                   Each/year
Each
Component              Unit   Unit Cost
DIRECT OPERATION AND MAINTENANCE
Inspection             hour         $40
Erosion Repair         lump      $2,000
Vegetation Repair      lump          $0

TOTAL DIRECT O&M PRESENT WORTH
Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
                     Present
$/year     Years      Worth

   $1,280       30   $15,884
   $2,000        5    $8,200
       $0        5        $0

                      $24,084

                      Present
                       Worth
                                                   $1,204
                                                   $1,204
                                                   $6.021

                                                   $8,429
                                                                                 GRAND  TOTAL
                                                                $32,513

                                                               $138,413
Source: TerraMatrix/SMI 1998

-------
                                            TABIiE 19
                       COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE  2
                                  STREAM CHANNEL RECONSTRUCTION
California Gulch NPL Site
OU4 - FFS - UCG 92A
Alternative 2 - Stream Channel Reconstruction

DIRECT CAPITAL COSTS
Component                           Unit    Unit Cost    Quantity     Total  Cost

Improve Access Road                  If          $3.00          700          $2,100
Channel Construction
              Riprap Placement       cy         $63.00         240         $15,120
Cultural Resources                  lump        $2,000           1          $2,000
Dust Control                        lump        $2,000           1          $2,000
Sediment Control                    lump        $2,000           1          $2,000

TOTAL DIRECT CAPITAL COSTS
              $23,220
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
$2,322
$5,805
$1,161
$1,161
$4,644
$1,625
              $16,718
TOTAL CAPITAL COSTS
                             $39,938

-------
POST REMEDIATION SITE CONTROL COSTS
                    Discount    7.00% for present worth
Component              Unit   Unit Cost    Each
DIRECT OPERATION AND MAINTENANCE
Inspection             hour         $40
Erosion Repair         lump      $2,000
Vegetation Repair      lump      $1,200

TOTAL DIRECT O&M PRESENT WORTH
Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH


Each/year
8
1
0
4
1
0


$/year Years
$1,280
$2,000
$0
4
4
4
Present
Worth
$4,336
$6,774
$0
 $11,110

Present
 Worth
    $556
    $556
  $2,778
  $3,
                                                                                  GRAND TOTAL
                $14,999

                $54,937
Source: TerraMatrix/SMI 1998

-------
                                            TABIiE 20
                       COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 2
                            STREAM CHANNEL RECONSTRUCTION AND REGRADING

California Gulch NPL Site
OU4 - FFS - UCG 92A
Alternative 3 - Stream Channel Reconstruction/Regrade Waste Rock
DIRECT CAPITAL COSTS

Component                           Unit    Unit Cost    Quantity    Total Cost

Improve Access Road                  If          $3.00         700         $2,100
Regrade Waste Rock                 cu-yd         $1.00          300           $300
Channel Construction
              Riprap Placement       cy         $63.00        240         $15,120
Cultural Resources                  lump        $2,000           1         $2,000
Dust Control                        lump        $2,000           1         $2,000
Sediment Control                    lump        $2,000           1         $2,000

TOTAL DIRECT CAPITAL COSTS

INDIRECT CAPITAL COSTS
              $23,520
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
$2,352
$5,880
$1,176
$1,176
$4,704
$1,646
              $16,934
                             $40,454

-------
POST REMEDIATION SITE CONTROL COSTS
                    Discount    7.00% for present worth
Component
                       Unit   Unit Cost
                                           Each
DIRECT OPERATION AND MAINTENANCE
Inspection             hour         $40
Erosion Repair         lump      $2,000
Vegetation Repair      lump      $1,200

TOTAL DIRECT O&M PRESENT WORTH
Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH


Each/year
8
1
0
4
1
0


$/year Years
$1,280
$2,000
$0
4
4
4
Present
Worth
$4,336
$6,774
$0
 $11,110

Present
 Worth
    $556
    $556
  $2,778

  $3,889
                                                                                  GRAND TOTAL
                $14,999

                $55,453
Source: TerraMatrix/SMI 1998

-------
                                            TABIiE 21
                       COST SUMMARY: PRINTER GIRL WASTE ROCK ALTERNATIVE 4
                                       WASTE ROCK REMOVAL

California Gulch NPL Site
OU4 - Focused Feasibility Study - UCG 92A
Alternative 4 - Remove Waste Rock in Stream to UCG-71/Revegetate

DIRECT CAPITAL COSTS
Component

Construct Access Road
Channel Construction
              Riprap Placement
              Diversion Ditches
              Culverts
Load and Haul Waste Rock
Amend Soil and Revegetation
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS
    Unit     Unit  Cost     Quantity    Total Cost

     If           $5.25          700          $3,675
cy
sq-ft
If
cu-yd
acre
lump
lump
lump
$63.00
$5.00
$50.00
$10.00
$8,100
$2,000
$2,000
$2,000
280
1080
40
300
1.0
1
1
1
$17, 640
$5,400
$2,000
$3,000
$8,100
$2,000
$2,000
$2,000
                                                         $45,815
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
EPA Fees  (20% of Engineering, 5

TOTAL INDIRECT CAPITAL COSTS
(20%  of  Direct)
 of Direct)
 $4,582
$11,454
 $2,291
 $2,291
 $9,163
 $3,207
                                                         $32,987
TOTAL CAPITAL COSTS
                                                                        $78,802

-------
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
Erosion Repair         lump      $2,000
Vegetation Repair      lump      $1,200

TOTAL DIRECT O&M PRESENT WORTH
Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
$/year
                                                                                  Years
                       $1,280
                       $2,000
                           $0
Present
 Worth
                      $4,336
                      $6,774
                      $4,065

                     $15,175

                    Present
                     Worth
                                            $759
                                            $759
                                          $3,794

                                          $5,311
                                                                                 GRAND  TOTAL
                                                        $20,486

                                                        $99,288
Source: TerraMatrix/SMI 1998

-------
                                            TABIiE 22
                     COST SUMMARY: NUGGET GULCH IflASTE ROCK ALTERNATIVE  2
                                       DIVERSION DITCHES
California Gulch NPL Site
OU4 - FFS - NUGGET GULCH
Alternative 2 - Diversion Channels

DIRECT CAPITAL COSTS
Component

Improve Access Roads
Channel Construction
              Riprap
              Lined
              Unlined
              Culverts
Drainage Gravel
Geotextile
Perf. Drain Pipe
Cultural Resources
Dust Control
Sediment Control
Unit
If
cy
sf
sf
If
cy
sf
If
lump
lump
lump
Unit Cost
$3.00
$63.00
$7.50
$2.00
$50,000
$17.00
$0.35
$45.00
$10,000
$5,000
$5,000
Quantity Total Cost
200
370
1,050
15,600
60
280
6,500
250
1
1
1
$600
$23,310
$7,875
$31,200
$3,000
$4,760
$2,275
$11,250
$10,000
$5,000
$5,000
TOTAL DIRECT CAPITAL COSTS
                                                         $104,270
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
EPA Fees  (20% of Engineering, 5

TOTAL INDIRECT CAPITAL COSTS
(20%  of  Direct)
 of Direct)
$10,427
$26,068
 $5,214
 $5,214
$20,854
 $7,299
                                                         $75,074
TOTAL CAPITAL COSTS
                                                                        $179,344

-------
POST REMEDIATION SITE CONTROL COSTS
                    Discount    7.00% for present worth
Component
                       Unit   Unit Cost
                                           Each
DIRECT OPERATION AND MAINTENANCE
Inspection             hour         $40
Erosion Repair         lump     $10,000
Vegetation Repair      lump          $0

TOTAL DIRECT O&M PRESENT WORTH


Each/year
24
1
1
4
1
1


$/year Years
$3,840
$10,000
$0
30
5
5
Present
Worth
$47,651
$41,002
$0
                                                                                                !,653
Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
                                                                                            Present
                                                                                             Worth
 $4,433
 $4,433
$22,163

$31,029
                                                                                  GRAND TOTAL
              $119,682

              $299,026
Source: TerraMatrix/SMI 1998

-------
                                            TABIiE 23
                     COST SUMMARY: NUGGET GULCH IflASTE ROCK ALTERNATIVE  3
                           DIVERSION DITCHES AND WASTE ROCK REGRADING

California Gulch NPL Site
OU4 - FFS - NUGGET GULCH
Alternative 3 - Regrade UCG-71, 74, 77, 85/Diversion Channels/Terraces

DIRECT CAPITAL COSTS
Component

Improve Access Roads
Regrading
Channel Construction
              Riprap
              Lined
              Unlined
              Culverts
Construct Terraces
Amend & Reveg
Drainage Gravel
Geotextile
Perf. Drain Pipe
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS
                                    Unit
Unit Cost
Quantity
                                                                      Total  Cost
If
cy
cy
sf
sf
If
If
ac
cy
sf
If
lump
lump
lump
$3.00
$1.00
$63.00
$7.50
$2.00
$50.00
$3.00
$8.100
$17.00
$0.35
$45.00
$10,000
$5,000
$5,000
500
$14,200
370
1,050
15, 600
60
600
1
280
6,500
250
1
1
1
$1,500
$14,200
$23,310
$7,875
$31,200
$3,000
$1,800
$8,100
$4,760
$2,275
$11,250
$10,000
$5,000
$5,000
                                                 $129,270
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
                              $12,927
                              $32,318
                               $6,464
                               $6,464
                              $25,854
                               $9,049
                                                 $93,074
TOTAL CAPITAL COSTS
                                                                $222,344

-------
POST REMEDIATION SITE CONTROL COSTS
                    Discount    7.00% for present worth
Component
                       Unit   Unit Cost
                                           Each
DIRECT OPERATION AND MAINTENANCE
Inspection             hour         $40
Erosion Repair         lump     $10,000
Vegetation Repair      lump      $5,000

TOTAL DIRECT O&M PRESENT WORTH
Component

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&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH


Each/year
24
1
1
4
1
1


$/year Years
$3,840
$10,000
$5,000
30
5
5
Present
Worth
$47,651
$41,002
$20,501
 $109,154

Present
 Worth
   $5,458
   $5,458
  $27,289

  $38,204
                                                                                  GRAND TOTAL
                $147,358

                $369,702
Source: TerraMatrix/SMI 1998

-------
                                         TABLE 24
                COST SUMMARY: NUGGET GULCH WASTE ROCK ALTERNATIVE 4 -
                     DIVERSION DITCHES, CONSOLIDATION AND COVER

California Gulch NPL Site
OU4 - FFS - NUGGET GULCH
Alternative 4 - Move UCG-74, 76, 77, 85 to UCG-71/Amend and Revegetate UCG-74, 76,  77,  85/
                Regrade UCG-71, Simple Cover, Revegetate UCG-71/Diversion Channels/Terraces
DIRECT CAPITAL COSTS

Component

Improve Access Road
Load and Haul Waste Rock
Amend and Revegetation
Cover Material and Placement
Revegetate UCG-71
Regrading
Channel Construction
          Riprap
          Concrete
          Unlined
          Culverts
Terraces
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS
Unit
Unit Cost   Quantity    Total Cost
If
cy
ac
cy
ac
cy
cy
sf
sf
If
If
lump
lump
lump
$3.00
$5.00
$8,100
$11.75
$8,100
$1.00
$63.00
$7.50
$2.00
$50.00
$3.00
$10,000
$5,000
$5,000
500
19,250
6.00
8,300
5.00
19,250
300
1,050
10,400
60
1,750
1
1
1
$1,500
$96,250
$48, 600
$97,525
$40,500
$19,250
$18,900
$7,875
$20,800
$3,000
$5,250
$10,000
$5,000
$5,000
                                               $379,450
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
                                   $37,945
                                   $94,863
                                   $18,973
                                   $18,973
                                   $75,890
                                   $26,562
                                               $273,204
                                                           $652,654

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
Component
                      7.00% for present worth

Unit   Unit Cost   Each   Each/year   5/year
DIRECT OPERATION AND MAINTENANCE
Inspection          hour         $40     24
Erosion Repair      lump     $10,000      1
Vegetation Repair   lump      $5,000      1

TOTAL DIRECT O&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
                                  4    $3,840
                                  1   $10,000
                                  1    $5,000
                                                                    Years
                                                                             Present
                                                                             Worth
30   $47,651
 5   $41,002
 5   $20,501

    $109,154

     Present
     Worth
                                                         $5,458
                                                         $5,458
                                                        $27,289

                                                        $38,204
                                                               GRAND TOTAL
                                                                    $147,358

                                                                    $800,012
Source: TerraMatrix/SMI 1998

-------
                                      TABIiE 25
                COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE  2
                                  DIVERSION DITCHES
California Gulch NPL Site
OU4 FFS - AY-MINNIE
Alternative 2 - Diversion Channels

DIRECT CAPITAL COSTS
Component

Channel Construction
          Rip Rap
          Lined
          Unlined
          Culverts
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS

INDIRECT CAPITAL COSTS
                             Unit
Unit Cost   Quantity
                                                              Total  Cost
cy
sf
sf
If
lump
lump
lump
$63.00
$7.50
$2.00
$50.00
$5,000
$2,000
$2,000
300
5,100
4,300
30
1
1
1
$22,050
$38,250
$8, 600
$1,500
$5,000
$2,000
$2,000
                                       $79,400
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
                            $7,940
                           $19,850
                            $3,970
                            $3,970
                           $15,880
                            $5,558
                                       $57,168
                                                   $136,568

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
Component
                      7.00% for present worth

Unit   Unit Cost   Each   Each/year   5/year    Years
DIRECT OPERATION AND MAINTENANCE
Inspection          hour         $40      8
Erosion Repair      lump      $2,000      1
Vegetation Repair   lump          $0      1

TOTAL DIRECT O&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
                                  4    $1,280
                                  1    $2,000
                                  1        $0
30
 5
 5
                                                                             Present
                                                                             Worth
$15,884
 $8,200
     $0

$24,084

Present
Worth
                                                         $1,204
                                                         $1,204
                                                         $6,021

                                                         $8,429
                                                               GRAND TOTAL
                                                                    $32,513

                                                                   $169,081
Source: TerraMatrix/SMI 1998

-------
                                      TABIiE 26
                COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE  3
                         DIVERSION DITCHES AND REGRADING
California Gulch NPL Site
OU4 FFS - AY-MINNIE
Alternative 3 - Diversion Channels/Regrading
DIRECT CAPITAL COSTS

Component

Channel Construction
          Rip Rp
          Lined
          Unlined
          Culvert
Regrading
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS

INDIRECT CAPITAL COSTS
Unit
Unit Cost   Quantity
                                Total Cost
cy
sf
sf
If
cy
lump
lump
lump
$63.00
$7.50
$2.00
$50.00
$1.00
$5,000
$2,000
$2,000
350
5,100
4,300
30
8,750
1
1
1
$22,050
$38,250
$8, 600
$1,500
$8,750
$5,000
$2,000
$2,000
                                               $88,150
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
                                    $6,171
                                               $63,468
                                                            $151,618

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
Component
                      7.00% for present worth

Unit   Unit Cost   Each   Each/year   5/year    Years
DIRECT OPERATION AND MAINTENANCE
Inspection          hour         $40      8
Erosion Repair      lump      $2,000      1
Vegetation Repair   lump          $0      1

TOTAL DIRECT O&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
                                  4    $1,280
                                  1    $2,000
                                  1        $0
30
 5
 5
                                                                             Present
                                                                             Worth
$15,884
 $8,200
     $0

$24,084

Present
Worth
                                                         $1,204
                                                         $1,204
                                                         $6,021

                                                         $8,429
                                                               GRAND TOTAL
                                                                    $32,513

                                                                   $184,131
Source: TerraMatrix/SMI 1998

-------
                                      TABIiE 27
                COST SUMMARY: AY-MINNIE WASTE ROCK ALTERNATIVE  4
                    DIVERSION DITCHES AND ROAD RECONSTRUCTION

California Gulch NPL Site
OU4 FFS - AY-MINNIE
Alternative 4 - Diversion Channels/Realign Road/Sediment  Pond
DIRECT CAPITAL COSTS

Component

Channel Construction
          Rip Rap
          Lined
          Unlined
          Culvert
Road Work
          Earthworks
          Sub-Base
          Pavement  (3 in)
Sediment Dam
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS

INDIRECT CAPITAL COSTS
Unit
Unit Cost   Quantity
                                Total Cost
cy
sf-wp
cy
If
cy
cy
sy
lump
lump
lump
lump
$63.00
$7.50
$2.50
$43.00
$1.00
$36.50
$5.40
$5,000
$5,000
$2,000
$2,000
350
5,100
4,300
30
1,342
485
2,912
1
1
1
1
$22,050
$38,250
$10,750
$1,290
$1,342
$17,703
$15,725
$5,000
$5,000
$2,000
$2,000
                                               $121,109
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
                                   $12,111
                                   $30,277
                                    $6,055
                                    $6,055
                                   $24,222
                                    $8,478
                                               $87,198
                                                            $208,307

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
Component
                        Unit
       7.00% for present worth

Unit Cost   Each   Each/year   5/year
DIRECT OPERATION AND MAINTENANCE
Inspection              hour             $40
Sediment Removal  See Fluvial site 4
Erosion Repair          lump          $2,000
Vegetation Repair       lump              $0

TOTAL DIRECT O&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
                                $1,280

                                $2,000
                                    $0
                                                                            Years
30

 5
 5
     Present
     Worth
$15,884

 $8,200
     $0

$24,084

Present
Worth
                                                  $1,204
                                                  $1,204
                                                  $6,021

                                                  $8,429
                                                               GRAND TOTAL
                                                           $32,513

                                                          $240,820
Source: TerraMatrix/SMI 1998

-------
                                     TABIiE 28
                COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 2
                                 DIVERSION DITCHES
California Gulch NPL Site
OU4 - FFS - UCG-12
Alternative 2 - Diversion Channels

DIRECT CAPITAL COSTS
Component

Improve Access Road
Diversion Channels
Amend Soil and Revegetation
Cultural Resources
Dust Control
Sediment Control
TOTAL DIRECT CAPITAL COSTS
                             Unit
Unit Cost   Quantity
                                                             Total  Cost
If
sq-ft
acre
lump
lump
lump
$3.00
$7.50
$8,100
$2,000
$5,000
$2,000
2,000
1,000
3.3
1
1
1
$6,000
$7,500
$26,730
$2,000
$5,000
$2,000
                                       $49,230
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
                            $4,923
                           $12,308
                            $2,462
                            $2,462
                            $9,846
                            $3,446
                                       $35,446
TOTAL CAPITAL COSTS
                                                    $84,676

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
Component
                      7.00% for present worth

Unit   Unit Cost   Each   Each/year   5/year    Years
DIRECT OPERATION AND MAINTENANCE
Inspection          hour         $40      8
Erosion Repair      lump      $2,000      1
Vegetation Repair   lump          $0      1

TOTAL DIRECT O&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
                                  4    $1,280
                                  1    $2,000
                                  1        $0
30
 5
 5
                                                                             Present
                                                                             Worth
$15,884
 $8,200
     $0

$24,084

Present
Worth
                                                         $1,204
                                                         $1,204
                                                         $6,021

                                                         $8,429
                                                               GRAND TOTAL
                                                                    $32,513

                                                                   $117,189
Source: TerraMatrix/SMI 1998

-------
                                      TABIiE 29
                COST SUMMARY: IRON HILL WASTE ROCK ALTERNATIVE 3
                                 REGRADING AND COVER

California Gulch NPL Site
OU4 - FFS - UCG-12
Alternative 3 - Minor Grading/Simple Cover/Revegetation

DIRECT CAPITAL COSTS
Component

Improve Access Road
Regrade
Cover Soil Supply
Cover Soil Placement
Revegetation
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS

INDIRECT CAPITAL COSTS
                             Unit
Unit Cost   Quantity
                                                             Total Cost
If
cu-yd
cu-yd
cu-yd
acre
lump
lump
lump
$3
$1
$10
$1
$8,
$2,
$5,
$2,
.00
.00
.00
.75
100
000
000
000
2,
1,
1,
1,




000
000
700
700
3.







7
1
1
1
$6,
$1,
$17,
$2,
$29,
$2,
$5,
$2,
000
000
000
975
970
000
000
000
                                       $65,945
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% or Engineering, 5% or Direct)

TOTAL INDIRECT CAPITAL COSTS

TOTAL CAPITAL COSTS
                            $6,595
                           $16,486
                            $3,297
                            $3,297
                           $13,189
                            $4,616
                                       $47,480
                                                   $113,425

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
Component
                      7.00% for present worth

Unit   Unit Cost   Each   Each/year   5 /year
DIRECT OPERATION AND MAINTENANCE
Inspection          hour         $40      8
Erosion Repair      lump      $2,000      1
Vegetation Repair   lump      $2,500      1

TOTAL DIRECT O&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
                                       $1,280
                                       $2,000
                                       $2,500
                                                                    Years
                                                                             Present
                                                                             Worth
30   $15,884
 5    $8,200
 5   $10,250

     $34,334

     Present
     Worth
                                                         $1,717
                                                         $1,717
                                                         $8,584

                                                        $12,017
                                                               GRAND TOTAL
                                                                    $46,351

                                                                   $159,776
Source: TerraMatrix/SMI 1998

-------
                                     TABIiE 30
                 COST SUMMARY: IRON HILL IflASTE ROCK ALTERNATIVE 4
                              WASTE ROCK CONSOLIDATION
 California Gulch NPL Site
 OU-4 Focused Feasibility Study - UCG 12
 Alternative 4 - Remove Waste Rock to UCG-71

 DIRECT CAPITAL COSTS
 Component

 Improve Access Road
-Load and Haul Waste Rock
 Cultural Resources
 Amend Soil and Revegetation
 Dust Control
 Sediment Control

 TOTAL DIRECT CAPITAL COST
Unit

 If
cu-yd
 lump
_acre
 lump
 lump
Unit Cost

     $3.00
    $11.00
    $2,000
    $8,100
    $5,000
    $2,000
Quantity

    2,000
    5,500
        1
      3.7
        1
        1
Total Cost

     $6,000
    $60,500
     $2,000
    $29,970
     $5,000
     $2,000
                                                                 $105,470
 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
                                                        $26,368
                                                         $5,274
                                                         $5,274
                                                        $21,094
                                                         $7,383
                                                                  $75,938

                                                                 $181,408

-------
   POST  REMEDIATION SITE CONTROL COSTS
                              Discount
                                                                      7.00%  for present worth
Component Unit Unit Cost Each Each/ year $/year
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40 8 4 $1,280
Erosion Repair lump $2,000 1 1 $2,000
Vegetation Repair lump $2,500 1 1 $2,500
TOTAL DIRECT O&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)
Present
Years Worth

30 $15,884
5 $8,200
5 $10,250
$34,334
Present
Worth
$1,717
$1,717
$8,584
    TOTAL INDIRECT O&M PRESENT WORTH

    TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
$12,017
                                                                                                                             GRAND TOTAL
           $46,351

          $227,759
Source: TerraMatrix/SMI 1998

-------
                                    TABIiE 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

Improve Access Road
Channel Preparation
                Excavation
                Grading
                Riprap Lining
Surface Regrading
Amend Soil and Reveg
Cultural Resources
Dust Control
Sediment Control

INDIRECT CAPITAL COSTS
 Unit

  If

  cy
  cy
- cy
  ac
  ac
 lump
 lump
 lump
Unit Cost
      $3.00
Quantity
      500
$2.50
$2.50
$63.00
$1,000
$8,100
$10,000
$1,000
$1,000
9,175
3,375
4,175
4
4
1
1
1
                                   Total Cost
  $1,500

 $22,938
  $8,438
$263,025
  $4,000
 $32,400
 $10,000
  $1,000
  $1,000
                                                        $299,900
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
                                                          $29,990
                                                          $74,975
                                                          $14,995
                                                          $14,995
                                                          $59,980
                                                          $20,993
                                                                        $215,928
                                                                                     $515,828

-------
POST REMEDIATION SITE CONTROL COSTS
                            Discount
Component
                         Unit
                                     Unit Cost
                                           $40
                                        $2,000
                                            $0
DIRECT OPERATION AND MAINTENANCE
Inspection                hour
Erosion Repair            lump
Vegetation Repair         lump

TOTAL DIRECT O&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


Source: TerraMatrix/SMI 1998
   7.00% for present worth

Each          Each/year
$/year
                                    $1,280
                                    $2,000
                                        $0
                                                                                                            Years
                        30
                         5
                         5
Present
Worth
   $15,884
    $8,200
        $0

   $24,084
Present
Worth
                                                                                                                             $1,204
                                                                                                                             $1,204
                                                                                                                             $6,021

                                                                                                                             $8,429
                                                                                                              GRAND  TOTAL
                                                                                  $32,513

                                                                                 $548,341

-------
                                      TABIiE 32
                COST SUMMARY: CALIFORNIA GULCH WASTE ROCK ALTERNATIVE  3-
                                  SELECTED REGRADING
California Gulch NPL Site
OU4 - FFS - California Gulch Waste Rock Piles
Alternative 3 - Waste Rock Regrading

DIRECT CAPITAL COSTS
Component

Improve Access Road
Regrade
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COST
Unit

  If
cu-yd
 lump
 lump
 lump
Unit Cost

     $3.00
     $1.00
    $2,000
    $5,000
    $2,000
Quantity

    1,200
    7,500
        1
        1
        1
Total Cost

     $3,600
     $7,500
     $2,000
     $5,000
     $2,000
                                                                      $20,100
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
                                                         $2,010
                                                         $5,025
                                                         $1,005
                                                         $1,005
                                                         $4,020
                                                         $1,407
                                                                       $14,472
TOTAL CAPITAL COSTS
                                                                                               $34,572

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount

Component

DIRECT OPERATION AND MAINTENANCE

Inspection
Erosion Repair
Vegetation Repair

TOTAL DIRECT O&M PRESENT WORTH

Component

INDIRECT OPERATION AND I
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


   Source: TerraMatrix/SMI 1998
7.00% for present worth
Unit Unit Cost Each Each/year $/year
1l\TZ\l\TriTP
jlN-rtlNL-Ilj
hour $40 8 4 $1,280
lump $2,000 1 1 $2,000
lump $2,500 0 0 $0
JRTH
ITENANCE COSTS
:t O&M)
:M)
Present
Years Worth
30 $15,884
5 $8,200
0 $0
$24,084
Present
Worth
$1,204
$1,204
$6,021
                                                                     $8,429
                                                     GRAND TOTAL
 $32,513

$67,085

-------
                                      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

 Improve Access Road
-Load and Haul Waste Rock
 Cultural Resources
 Amend Soil and Revegetation
 Dust Control
 Sediment Control

 TOTAL DIRECT CAPITAL COST
Unit

 If
cu-yd
 lump
_acre
 lump
 lump
Unit Cost

     $3.00
    $11.00
   $10,000
    $8,100
   $10,000
    $2,000
Quantity

    1,200
   15,000
        1
      3.7
        1
        1
Total Cost

     $3,600
   $165,000
    $10,000
    $29,970
    $10,000
     $2,000
                                                                     $220,570
 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
                                                        $22,057
                                                        $55,143
                                                        $11,029
                                                        $11,029
                                                        $44,114
                                                        $15,440
                                                                     $158,810
                                                                                                $379,380

-------
POST REMEDIATION SITE CONTROL COSTS
                          Discount
                                                                   7.00%  for present worth

Component Unit Unit Cost Each Each/ year $/year
DIRECT OPERATION AND MAINTENANCE
Inspection hour $40 8 4 $1,280
Erosion Repair lump $2,000 1 1 $2,000
Vegetation Repair lump $2,500 1 1 $2,500
TOTAL DIRECT O&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)
Present
Years Worth

30 $15,884
5 $8,200
5 $10,250
$34,334
Present
Worth

$1,717
$1,717
$8,584
TOTAL INDIRECT O&M PRESENT WORTH

TOTAL OPERATION AND MAINTENANCE PRESENT WORTH
$12,017
                                                                                                                         GRAND TOTAL
           $46,351

          $425,731

-------
                                               TABLE 34
                            COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 2  -
                                 CHANNEL RECONSTRUCTION AND REVEGETATION
California Gulch NPL Site
OU4 - FFS - FLUVIAL SITE 4
Alternative 2 - Stream Channel Reconstruction/Surface Stabilization

DIRECT CAPITAL COSTS
Component

Improve Access Road
Channel Preparation
                Excavation
                Grading
                Riprap Lining
Surface Regrading
Amend Soil and Reveg
Cultural Resources
Dust Control
Sediment Control
Unit

 If

 cy
 cy
 cy
 ac
 ac
lump
lump
lump
                                                                   Unit Cost
$3.00
            Quantity
700
                                                                                                       Total  Cost
$2,100
$2.50
$2.50
$63.00
$1,000
$8,100
$15,000
$4,000
$2,000
36,700
13,500
16,700
16
16
1
1
1
$91,750
$33,750
$1,052,100
$16,000
$129,600
$15,000
$4,000
$2,000
                                               $1,346,930
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
                                                        $201,945
                                                        $336,575
                                                         $67,315
                                                         $67,315
                                                        $134,630
                                                        $107,704
                                                                       $915,484
TOTAL CAPITAL COSTS
                                                                                   $2,261,784

-------
 POST REMEDIATION SITE CONTROL COSTS
                             Discount
                                                            7.00%  for present  worth
 Component
                          Unit
 DIRECT OPERATION AND MAINTENANCE
 Inspection                hour
 Erosion Repair            lump
 Vegetation Repair         lump

 TOTAL DIRECT O&M PRESENT WORTH
Unit Cost
$40
$2,000
$18,000
Each
8
1
1
Each/year
4
1
1
$/year
$1,280
$2,000
$18,000
Years
30
5
5
Present
Worth
$15,884
$8,200
$73,804
$97,888
 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
                                                                                                                        Present
                                                                                                                          Worth
 $4,894
 $4,894
$24,472

$34,261
                                                                                                               GRAND TOTAL
             $132,149

            $2,393,933

-------
                                                       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 2 - Stream Channel Reconstruction/Sediment Dams and Wetlands

DIRECT CAPITAL COSTS
Component

Improve Access Road
Channel Preparation
                Excavation
                Grading
                Riprap Lining
Sediment Dams
Constructed Wetlands
Surface Wetlands
Cultural Resources
Dust Control
Sediment Control
Unit
If
cy
cy
cy
lump
ac
ac
lump
lump
lump
Unit Cost
$3.00
$2.50
$2.50
$63.00
$8,000.00
$17,000.00
$1,000
$15,000
$4,000
$2,000
Quantity
700
36,700
13,500
16,700
8
1.5
16
1
1
1
Total Cost
$2,100
$91,750
$33,750
$1,052,100
$64,000
$25,500
$16,000
$15,000
$4,000
$2,000
                                                                                        $1,306,200
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
EPA Fees  (20% of Engineering, 5

TOTAL INDIRECT CAPITAL COSTS
(20%  of  Direct)
 of Direct)
$195,930
$326,550
 $65,310
 $65,310
$130,620
$104,496
                                                                                                                                ,216
TOTAL CAPITAL COSTS
                                                                                                      $2,194,416

-------
POST REMEDIATION SITE CONTROL COSTS
                            Discount
Component
                         Unit
DIRECT OPERATION AND MAINTENANCE
Inspection                hour
Erosion Repair            lump

TOTAL DIRECT O&M PRESENT WORTH
Unit Cost
      $40
   $2,000
   7.00% for present worth

Each          Each/year
$/year
                                                                                                            Years
                                    $1,280
                                    $2,000
                        30
                         5
Present
Worth
   $15,884
    $8,200

   $24,084
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
                                                                                                                         Present
                                                                                                                         Worth
                                                                                        $1,204
                                                                                        $1,204
                                                                                        $6,021

                                                                                        $8,429
                                                                                                              GRAND TOTAL
                                                                                                    $32,513

                                                                                                   $2,226,929

-------
                                          TABIiE 36
                      COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE  4  -
            STREAM CHANNEL RECONSTRUCTION, SURFACE STABILIZATION,  SEDIMENT DAMS AND WETLANDS

California Gulch NPL Site
OU4 - FFS - FLUVIAL SITE 4
Alternative 4 - Stream Channel Reconstruction/Surface Stabilization/Sediment  Dams  and Wetlands

DIRECT CAPITAL COSTS
Component

Improve Access Road
Channel Preparation
                Excavation
                Grading
                Riprap Lining
Sediment Dams
Constructed Wetlands
Amend Soil and Reveg
Surface Regrading
Cultural Resources
Dust Control
Sediment Control
Unit
If
cy
cy
cy
lump
ac
ac
ac
lump
lump
lump
Unit Cost
$3.00
$2.50
$2.50
$63.00
$8,000.00
$17,000.00
$8,100
$1,000
$15,000
$4,000
$2,000
Quantity
700
36,700
13,500
16,700
8
1.5
16
16
1
1
1
Total Cost
$2,100
$91,750
$33,750
$1,052,100
$64,000
$25,500
$129, 600
$16,000
$15,000
$4,000
$2,000
TOTAL DIRECT CAPITAL COSTS
                                                                                          $1,435,800
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
EPA Fees  (20% of Engineering, 5

TOTAL INDIRECT CAPITAL COSTS
(10%  of  Direct)
 of Direct)
$215,370
$358,950
 $71,790
 $71,790
$143,580
$114,864
                                                                                           $976,344
TOTAL CAPITAL COSTS
                                                                                                      $2,412,144

-------
POST REMEDIATION SITE CONTROL COSTS
                            Discount
Component
                         Unit
                                     Unit Cost
                                           $40
                                        $2,000
                                       $18,000
   7.00% for present worth

Each          Each/year
DIRECT OPERATION AND MAINTENANCE
Inspection                hour
Erosion Repair            lump
Vegetation Repair         lump

TOTAL DIRECT O&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
$/year
                                    $1,280
                                    $2,000
                                   $18,000
                                                                                                            Years
                        30
                         5
                         5
Present
Worth
   $15,884
    $8,200
   $73,804

   $97,888
Present
Worth
                                                                                                                             $4,894
                                                                                                                             $4,894
                                                                                                                            $24,472
                                                                                                                            $34,261
                                                                                                              GRAND TOTAL
                                                                                                                                          $132,149

                                                                                                                                        $2,544,293

-------
                                       TABLE 37
                  COST SUMMARY: FLUVIAL TAILING SITE 4 ALTERNATIVE 5 -
      STREAM CHANNEL RECONSTRUCTION, SURFACE STABILIZATION, SELECTED REMOVAL,
                               SEDIMENT DAMS AND WETLANDS

California Gulch NPL Site
OU4 - FFS - FLUVIAL SITE 4
Alternative 5 - Stream Channel Reconstruction/Surface Stabilization/Selected Removal/Sediment Dams and Wetlands

DIRECT CAPITAL COSTS
Component

Improve Access Road
Channel Preparation
                Excavation
                Grading
                Riprap Lining
Sediment Dams
Excavate Surface Material
Sediment Retention Cribbing
Constructed Wetlands
Amend Soil and Reveg
Surface Regrading
Cultural Resources
Dust Control
Sediment Control

TOTAL DIRECT CAPITAL COSTS

INDIRECT CAPITAL COSTS
Unit

 If

 cy
 cy
 cy
lump
 cy
 If
 ac
 ac
 ac
lump
lump
lump
                                                                   Unit Cost
Quantity
Total Cost

       $2,100

      $91,500
      $33,750
   $1,052,100
      $64,000
      $40,000
      $25,000
      $25,500
     $129,600
      $16,000
      $15,000
       $4,000
       $2,000
                                                                      $1,500,800
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
                                                       $225,120
                                                       $375,200
                                                        $75,040
                                                        $75,040
                                                       $150,080
                                                       $120,064
                                                                      $1,020,544
TOTAL CAPITAL COSTS
                                                                                   $2,521,344

-------
POST REMEDIATION SITE CONTROL COSTS
                            Discount
Component
                         Unit
DIRECT OPERATION AND MAINTENANCE
Inspection                hour
Erosion Repair            lump
Vegetation Repair         lump

TOTAL DIRECT O&M PRESENT WORTH
Unit Cost
      $40
   $2,000
  $18,000
   7.00% for present worth

Each          Each/year
$/year
                                    $1,280
                                    $2,000
                                   $18,000
                                                                                                            Years
                        30
                         5
                         5
Present
Worth
   $15,884
   -$8,200
   $73,804

   $97,985
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
                                                                                                                         Present
                                                                                                                         Worth
                                                                                        $4,894
                                                                                        $4,894
                                                                                       $24,472

                                                                                       $34,261
                                                                                                              GRAND TOTAL
                                                                                                     $132,149

                                                                                                   $2,653,493

-------
TABLE 38
COMPARISON OF ALTERNATIVES FOR GARIBALDI SUB-BASIN WASTE ROCK - WAMP CRITERIA

Alternative 2 Alternative 3
Diversion of Surface Water and Stream Channel Diversion of Surface Water and
Reconstruction Selected Removal

No erosional stability measures would be Diversion channels and stream channel reconstruction Diversion channels will divert runon water away
taken. Side slopes may not meet WAMP will divert runon water away from the waste rock from the waste rock. Removal will remove waste
criteria. reducing surface erosion. rock from flood plain.

Not applicable to existing slopes. Retaining wall will be reguired to meet WAMP
criteria.

Diversion channels will be sized to pass the 100-year
event. Channel reconstructed to pass upstream flow and
remain stable for 5 00-year event.
Non-Residential Soils Not applicable. Not applicable. Not applicable.

Source: TerraMatrix/SMI 1998

-------
TABLE 39
COMPARISON OF ALTERNATIVES FOR THE PRINTER GIRL WASTE ROCK -
WAMP CRITERIA
Alternative 1
No Action
Alternative 3
Stream Channel
Reconstruction and
Regrading
No change in
existing erosional
stability; criteria do
not apply.
No change in
existing flow
capacity and
stability; criteria do
not apply.
Waste rock would be
stabilized for the 100-
year flood event in
Whites Gulch.
Waste rock would be
stabilized for the 100-year
flood event in Whites
Gulch.
Reduces erosion and
leaching associated with
stream channel contact
with wage rock.

Any risk to the terrestrial
ecosystem from the waste
rock would be reduced.
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.
Eliminates waste rock as
a source of
contamination.
Any risk to the terr
ecosystem from the
waste rock would be
eliminated.
Non-Residential Soils Not applicable.
Not applicable.
Not applicable.
Source: TerraMatrix/SMI 1998

-------
TABLE 40
COMPARISON OF ALTERNATIVES FOR THE
NUGGET GULCH WASTE ROCK - WAMP CRITERIA
Alternative 1
No Action
No change in existing
erosional stability; criteria
do not apply.
Diversion channels will
divert surface runon away
from waste rock, reducing
surface erosion.
Diversion channels will
divert surface runon away
from waste rock, reducing
surface erosion.
Consolidation and covering
will reduce surface erosion.
Terraces and revegetation will
stabilize disturbed areas.
Not applicable, no
remediation would occur.
Consolidation and regrading
of waste rock will improve
stability.
Surface Water(SW)and
Groundwater(GW)
Contaminant Loading
Reduction
No change in existing
flow capacity and
stability; criteria do not
apply.

No reduction in potential
loading.
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.
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.
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.
Terrestrial Ecosystem No change in potential
Exposure risk to terrestrial
ecosystem.

Non-Residential Soils Not applicable.

Source: TerraMatrix/SMI 1998
Any risk to the terrestrial
ecosystem from the waste
rock would be reduced.

Not applicable.
Any risk to the terrestrial
ecosystem from the waste
rock would be reduced.

Not Applicable.
Any risk to the terrestrial
ecosystem from the waste rock
would be eliminated.

-------
                                                                     TABLE 41
                                               COMPARISON OF ALTERNATIVES FOR THE AY-MINNIE WASTE ROCK-
                                                                  WAMP CRITERIA
                                Alternative  1
                                  No Action
                                                                Diversion ditches will divert
                                                                surface runon away
                                                                waste rock, reducing surface
                                                                erosion.
                                                                                                 Diversion ditches will  divert
                                                                                                       Diversion  ditches  will  divert
                                                                                                       surface  runon  away from
                                                                                                       waste rock,  reducing  surface
                                                                                                       erosion.
Surface Water(SW)and
Groundwater(GW)
Contaminant Loading
Reduction
No change in existing
flow capacity and
stability; criteria do not
apply.

No reduction in potential
loading.
                                                                Not applicable, no
                                                                remediation would o
                                                                                    11 be
Diversion ditches will prevent
runon water from contacting
the waste rock, thus
decreasing the loading to
surface water.
                                                                      Stability of the slopes
                                                                      be improved removal of
                                                                      cribbing and regrading.
                                                                      county road.
                                                                                                 D
                                                                                                  liversion ditches will  be
                                                                                                                   the  100-year
Diversion ditches will
runon water from contacting
the waste rock, thus
decreasing the loading to
surface water.
                                                                   The hazard presented by
                                                                   failure of the cribbing would
                                                                   be reduced by realignment of
                                                                                                                                   Diversion ditches will be
Diversion ditches will
prevent runon water from
contacting the waste rock,
thus decreasing the loading
surface water.
                           No change  in  potential

                           ecosystem.
                                     There would  be  little change     There would be little change     There would  be  little  change
                                     in potential risk to terrestrial in potential risk to terrestrial in potential risk  to terrestrial
                                     ecosystem.                        ecosystem.                       ecosystem.
                           Not applicable.
                                                                Not applicable.
                                                                                                 Not Applicable.
Source:  TerraMatrix/SMI 1998

-------
TABLE 42
COMPARISON OF ALTERNATIVES FOR THE IRON HILL WASTE ROCK-
WAMP CRITERIA
Alternative 1
No Action
Diversion channels will
divert surface runon away
from waste rock, reducing
surface erosion.
Regrading of one pile will
reduce slopes and erosion
potential. Covering of other
pile will eliminate erosion.
Consolidation and covering
will eliminate surface erosion
releases.
Not applicable, no
remediation would o
Regrading of the slopes
meet WAMP criteria.
Consolidated waste rock
would meet WAMP criteria.
No change in existing
flow capacity and
stability; criteria do not
apply.
Diversion channels will be
designed to pass the 100-
year flood event.
Covered pile would be
stabilized for the 100-year
flood event.
Surface Water(SW)and
Groundwater(GW)
Contaminant Loading
Reduction
Diversion channels will
prevent runon water from
contacting the waste rock,
thus decreasing the loading
to surface water.
One pile would be regraded
to reduce the amount of
infiltration caused by
ponding, the other pile
would be covered to reduce
leaching.
Consolidation and covering
decreases surface area for
direct infiltration and loading
to surface water.
Terrestrial Ecosystem No change in potential
Exposure risk to terrestrial
ecosystem.
Risk to the terrestrial
ecosystem from the waste
rock would be reduced
through cover.
By reducing contact surface,
risk to the terrestrial ecosystem
from the waste rock would be
reduced.
Not applicable.
Not applicable.
Not Applicable.
Source: TerraMatrix/SMI 1998

-------
TABLE 43
COMPARISON OF ALTERNATIVES FOR THE
CALIFORNIA GULCH WASTE ROCK - WAMP CRITERIA

Alternative 1
No Action

No change in existing Diversion channels will Regrading of slopes will Would eliminate waste rock as
erosional stability; criteria divert surface runon away reduce slopes and erosion an erosional source of
do not apply. from waste rock, reducing potential. contamination.
surface erosion.

Not applicable, no
remediation would occur.

No change in existing Diversion channels will be
flow capacity and designed to pass the 500-
stability; criteria do not year flood event.
apply.

Surface Water(SW)and No reduction in potential Diversion channels will Regrading reduces the
Groundwater(GW) loading. prevent runon water from amount of infiltration caused
Contaminant Loading contacting the waste rock, by ponding.
Reduction thus decreasing the loading
to surface water.
Little change in potential Little change in potential Any risk to the terrestrial
Not applicable. Not applicable. Not Applicable.

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                                                                                      TABLE  44
                                                         COMPARISON OF ALTERNATIVES FOR FLUVIAL TAILING SITE 4 - WAMP CRITERIA
                                   Alternative  1
                                      No  Action
                                          Alternative 2
                                    Channel  Reconstruction and
                                       Revegetation
                                            Alternative 3
                                       Channel Reconstruction,
                                        Sediment Dams and
                                             Wetlands
                                              Alternative 4
                                        Channel Reconstruction,
                                   Revegetation,  Sediment Dams
                                          and Wetlands
                                               Alternative 5
                                          Channel Reconstruction,
                                       Revegetation,  Sediment Dams,
                                      Wetlands  and Selected Surface
                                             Material Removal
                               No  change  in  existing
                               erosional  stability;  criteria
                               do  not  apply.
                                                                                                              Sediment discharge would be
                                                                                                              reduced through construction of
                                                                                                              sediment dams and wetlands.
                                                                                                                   Sediment generation and
                                                                                                                   discharge would be reduced due
                                                                                                                   to the revegetation of disturbed
                                                                                                                   area and the catchment of check
                                                                                                                   dams and wetlands.
Slope Stability
                                                                                                        Due  to its  flat topography,
                                                                                                        slope  stability is not an
                                                                                                        issue.
Flow Capacity and Stability
                               No  change  in  existing flow
                               capacity  and  stability;
                               criteria  do not  apply.
                                     Reconstruction of the upper
                                     California Gulch channel and
                                     floodplain will have capacity
                                     to  pass  500 - year flood event.
                                    Reconstruction of the upper
                                    California Gulch channel
                                    and  floodplain will have
                                    capacity to pass 500 - year
                                    flood event.
                                      Reconstruction of the upper
                                      California Gulch channel and
                                      floodplain will have capacity to
                                      pass  500  - year flood event.
                                          Reconstruction of the upper
                                          California Gulch channel and
                                          adj acent floodplain will have
                                          capacity to pass the 500 - year
                                          event.
Surface Water(SW)and
Groundwater(GW)
Contaminant Loading
Reduction
No reduction in potential
loading.
Non-Residential Soils          Not  applicable.

Source: TerraMatrix/SMI  1998
Loadings would be reduced by
limiting contact of water with
waste material and increased
erosional stability.
                                                                    Not applicable.
Loadings would be reduced by
by limiting contact of water
with waste material and  increased
increased erosional stability.

Potential risk to terrestrial
ecosystem would be
reduced.

Not applicable.
Loadings would be reduced by
limiting contact of water with
waste material and increased
erosional stability.
                                                                                                                                             Not applicable.
Loadings would be reduced by
limiting contact of water with
waste material and increased
erosional stability.

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                                                                 APPENDIX A
                                                     SUMMARY OF FEDERAL AND STATE ARARs
                                                               (Page 1 of 7)
      Standard,  Requirement
      Criteria,  or Limitation
        Citation
Potentially     Potentially
 Applicable    Relevant and
                Appropriate
                     Description
  FEDERAL ARARs

  Endangered Species Act
   16 USC ° 1531 et seq.
   50 CFR °° 200 and 402
                                   No
                                                  No
  Fish and Wildlife Coordination Act
  Wilderness Act
  Executive Order NO. 11988
  Floodplain Management

  Executive Order NO. 11990
  Protection of Wetlands
                                         16 USC ° 661 et seq.
                                            40 CFR ° 6.302
                                                                         No
                                                                                        No
  16 USC 1311,  16 USC 668
    50 CFR 53,  50 CFR 27

 40 CFR ° 6.302 & Appendix A
                                                                         No
     Yes
                                                                                        No
40 CFR ° 6.302 (a)  and Appendix    Yes
              A
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 floodplain management and construction and
impoundments in such areas.

Minimizes adverse impacts on areas designated as
wetlands.
  Section 404,  Clean Water Act
  (CWA)
      33 USC 1251 et seq.
        33 CFR Part 330
                                  Yes
                                Regulates discharge of dredged or fill materials into waters
                                of the United States. Substantive requirements of portions
                                of Nationwide Permit No. 38 (General and Specific
                                Conditions)  are applicable to OU4 remedial activities
                                conducted within waters of the United States.
Source: TerraMatrix/SMI 1998
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                                                           APPENDIX A (CONTINUED)
                                                     SUMMARY OF FEDERAL AND STATE ARARs
                                                               (Page 3 of 7)
      Standard,  Requirement
      Criteria,  or Limitation
  Clean Air Act
  National Primary and Secondary
  Ambient Air Quality Standards
           Citation
        40  CFR Part  50
Potentially
 Applicable
                                      No
 Potentially
Relevant and
 Appropriate

      No
  RCRA Land Disposal Restrictions
  (LDRs)
  Solid Waste Disposal Act as
  amended by the Resource
  Conservation and Recovery Act of
  1976 (RCRA)
       40  CFR Part  268
                                      No
                                                     No
  40  CFR Part  257,  Subpart A:°
 257.3-1 Floodplains,  paragraph
(a);  °  257.3-7 Air,  paragraph (b)
                                      Yes
Description
                              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 am 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 am not ARARs. See
                              Colorado Air Pollution Prevention and control Act
                              concerning applicability of requirements implemented
                              through the SIP.

                              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 #7.

                              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/SMI 1998
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                                                           APPENDIX A (CONTINUED)
                                                     SUMMARY OF FEDERAL AND STATE ARARs
                                                               (Page 4 of 7)
      Standard,  Requirement
      Criteria,  or Limitation
          Citation
Potentially     Potentially
 Applicable    Relevant and
                Appropriate
                                 Description
  STATE OF COLORADO ARARs
  Nongame,  Endangered or
  Threatened Species Act
                                             CRS °° 33-2-101 to 108
                                                                              No
  Colorado Register of Historic Places
  Colorado Historical,  Prehistorical,
  and Archaeological Resources Act
  Colorado Species or Special
  Concern and Species of
  Undetermined Status
   CRS
          24-80.1-101 to 108
                                     No
    CRS °° 24-80-401 to 410
          1301 to 1305
 Colorado Division of Wildlife
 Administrative Directive E-l,
        1985,  modified
                                     No
      No
 No       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, then
          requirements of Act will be applicable.

 No       Authorizes the State Historical Society to nominate
          properties for inclusion on the State Register of Historic
          Places. Applicable only if remedial activities impact an
          area listed on the Register.

Yes       Concerns historical, prehistorical, and archaeological
          resources; applies only to areas owned by the State or its
          political subdivisions. May be relevant and appropriate if
          remedial activities impact in archaeological site.

 No       Protects species listed on the Colorado Division of Wildlife
          generated list. Urges coordination with the Division of
          Wildlife if wildlife species are to be impacted. No evidence
          of species of special concern have been identified at this
          site.
 Colorado Natural Areas
  Colorado Solid Waste Disposal Sites
  and Facilities Act,  Colorado Revised
  Statutes,  Title 30,  Article 20,
  Sections 101-118
Colorado Revised Statutes,  Title     No
    33,  Article 33,  Sec. 104
            6 CCR 1007-2             No

        6 CCR 1007-2,  Part 1
                     No       Maintains a list of plant species of "special concern".
                              Although not protected by State statue,  coordination with
                              Division of Parks and Outdoor Recreation is recommend
                              if activities will impact listed species.

                     No       Establishes regulations for solid waste management
                              facilities, including location standards.  Proposed remedial
                              action in OU4 will not establish a solid waste management
                              facility.
Source:  TerraMatrix/SMI 1998
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                                                           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
         Citation
       6 CCR 1007-2
Potentially
 Applicable
                                    No
 Potentially
Relevant and
 Appropriate

      No
       5 CCR 1002-2
   CRS 34-32-101 to 125
Rule 3 of Mineral Rules and
        Regulations
                                   Yes
                                    No
                                                  Yes
  Colorado Air Pollution Prevention
  and Control Act
  Colorado Air Pollution Prevention
  and Control Act
  Colorado Air Pollution Prevention
  and Control Act
       5 CCR 1001-3;
  Sections III.D.l.b,c,d.
 Sections III.D.2.b,c,e,f.
       Regulation 1
       5 CCR 1001-4
       Regulation 2
           Odors

       5 CCR 1001-5
    Regulation 3 APENs
                                   Yes
                                   Yes
     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 applicable.

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 Groundwater),  Wildlife, and Revegetation 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 (5CCR
1001-3; Sections III.D.2.b,c,e,f). 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:  TerraMatrix/SMI 1998
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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
     Citation
  5 CCR 1001-14

  5 CCR 1001-10
Part C (I)  & (III)
  Regulation 8
Potentially
 Applicable
                               Yes
 Potentially
Relevant and
 Appropriate
  Colorado Noise Abatement Act
                                           CRS °° 25-12-101 to 108
                                                                             Yes
Description
                              Pursuant to the Colorado Air Pollution Prevention and
                              Control Act,  applicants for construction permits are
                              required to evaluate whether the proposed source will
                              exceed NAAQS.  Applicants am also required to evaluate
                              whether the proposed activities would cause the Colorado
                              ambient standard for TSP 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 for
                              fugitive emissions through Regulation No. 1. Compliance
                              with applicable provisions of the Colorado air quality
                              requirements  will be achieved by adhering to a fugitive
                              emissions control plan prepared in accordance with
                              Regulation No. 1.

                              Regulation 8  sets emission limits rot lead and hydrogen
                              sulfide. Applicants are required to evaluate whether the
                              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 to 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
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                                                           APPENDIX A  (CONTINUED)
                                                     SUMMARY OF FEDERAL AND STATE ARARs
                                                               (Page 7 of 7)
      Standard,  Requirement
      Criteria,  or Limitation
  Regulations an the Collection of
  Aquatic Life
  Colorado Hazardous Waste
  Regulations
           Citation
      2 CCR 406-8, Ch. 13,
    Article III,  Sec. 1316
Potentially
 Applicable
                                      No
6 CCR1007-3,  Part 264: Section
264.301,  (g), (h),  (i) and (j);
Section 264.310,  (a)(1)  through
             (a) (4);
  Section 264.310,  (b)(1)  and
             (b) (5)
                                                                              No
 Potentially
Relevant and
 Appropriate

      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
-------