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FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN, COLORADO Photo courtesy of Roger Rouch Prepared for: CBS Operations Inc. July 26, 2013 730 17 th Street, Suite 925 Denver, Colorado 80202

FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

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Page 1: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN, COLORADO

Photo courtesy of Roger Rouch

Prepared for: CBS Operations Inc. July 26, 2013 730 17th Street, Suite 925 Denver, Colorado 80202

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Focused Feasibility Study Eagle Mine Site July 26, 2013

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TABLE OF CONTENTS

Page

1.0 INTRODUCTION ................................................................................................. 1 1.1 Site Location and Mine History ................................................................. 1 1.2 Remediation History ................................................................................. 2 1.3 FFS Regulatory Background .................................................................... 6 1.4 Organization of the Document .................................................................. 7

2.0 WATER QUALITY ............................................................................................... 8 2.1 Site-Specific Water Quality Criteria .......................................................... 8

2.1.1 Segment 2 .................................................................................. 10 2.1.2 Segment 5a ................................................................................ 10 2.1.3 Segment 5b ................................................................................ 11 2.1.4 Segment 5c ................................................................................ 11 2.1.5 Segment 7b ................................................................................ 11

2.2 Water Quality Distribution within and between Segments ....................... 12

METAL LOADING ............................................................................................. 17 3.03.1 Segment 2 .............................................................................................. 20 3.2 Segment 5a ............................................................................................ 21 3.3 Segment 5b ............................................................................................ 28 3.4 Segment 5c ............................................................................................ 31 3.5 Loading Summary .................................................................................. 34

METAL SOURCE CHARACTERIZATION IN SEGMENT 5A ............................ 35 4.04.1 Belden .................................................................................................... 35

4.1.1 Groundwater Quality ................................................................... 35 4.1.2 Historic Tunnel ............................................................................ 38 4.1.3 Mill Level .................................................................................... 41 4.1.4 Conductivity Surveys .................................................................. 42 4.1.5 Railroad Ballast .......................................................................... 42

4.2 Waste Rock ............................................................................................ 45 4.2.1 The DER Summary of Waste Rock Zinc Loading to the River .... 50 4.2.2 Evaluation of Waste Rock as a Source, Leachate Method .......... 51

4.2.2.1 Leachant Volume Estimates ......................................... 51 4.2.2.2 Zinc Loading Estimates ................................................. 51 4.2.2.3 Waste Rock Leaching Conclusions ............................... 52

4.3 Rock Creek ............................................................................................ 53 4.4 OTP and Rex Flats ................................................................................. 56 4.5 Summary of Zinc Loading ...................................................................... 57

IDENTIFICATION OF ARARS AND REMEDIAL ACTION OBJECTIVES ......... 58 5.05.1 Identification of ARARs .......................................................................... 58

5.1.1 Potential Chemical-Specific ARARs and TBCs ........................... 60 5.1.2 Potential Location-Specific ARARs and TBCs ............................ 60 5.1.3 Potential Action-Specific ARARs and TBCs ................................ 60

5.2 Remedial Action Objectives ................................................................... 77

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TABLE OF CONTENTS (cont.)

Page

IDENTIFICATION AND SCREENING OF RESPONSE ACTIONS .................... 78 6.06.1 Identification of Response Actions ......................................................... 78 6.2 Framework for Institutional Controls ....................................................... 79 6.3 Description of Remedial Alternatives ...................................................... 81

DETAILED ANALYSIS OF ALTERNATIVES .................................................... 84 7.07.1 Detailed Analysis Process ...................................................................... 84

7.1.1 Threshold Criteria ....................................................................... 84 7.1.1.1 Overall Protection of Human Health and the

Environment ................................................................ 85 7.1.1.2 Compliance with ARARs ............................................... 85

7.1.2 Primary Balancing Criteria .......................................................... 85 7.1.2.1 Long-Term Effectiveness and Permanence .................. 85 7.1.2.2 Short-Term Effectiveness ............................................. 86 7.1.2.3 Reduction of Toxicity, Mobility, or Volume ..................... 86 7.1.2.4 Implementability ............................................................ 87 7.1.2.5 Cost .............................................................................. 87

7.1.3 Modifying Criteria ........................................................................ 88 7.2 Detailed Analysis of Alternative 1: No Added Action .............................. 88

7.2.1 Alternative 1: Threshold Criteria Evaluation ............................... 89 7.2.1.1 Overall Protectiveness of Human Health and the

Environment ................................................................ 89 7.2.1.2 Compliance with ARARs ............................................... 89

7.2.2 Alternative 1: Primary Balancing Criteria Evaluation .................. 89 7.2.2.1 Long-Term Effectiveness and Permanence .................. 90 7.2.2.2 Short-Term Effectiveness ............................................. 90 7.2.2.3 Reduction of TMV through Treatment ........................... 90 7.2.2.4 Implementability ............................................................ 90 7.2.2.5 Cost .............................................................................. 91

7.2.3 Alternative 1: Modifying Criteria ................................................. 91 7.2.3.1 State Acceptance .......................................................... 91 7.2.3.2 Public Acceptance ........................................................ 91

7.3 Detailed Analysis of Alternative 2A: Groundwater Collection and Treatment, Belden and Rock Creek ....................................................... 91 7.3.1 Alternative 2A: Threshold Criteria Evaluation ............................. 94

7.3.1.1 Overall Protectiveness of Human Health and the Environment ................................................................ 94

7.3.1.2 Compliance with ARARs ............................................... 94 7.3.2 Alternative 2A: Primary Balancing Criteria Evaluation ................ 95

7.3.2.1 Long-Term Effectiveness and Permanence .................. 95 7.3.2.2 Short-Term Effectiveness ............................................. 95 7.3.2.3 Reduction of TMV through Treatment ........................... 96 7.3.2.4 Implementability ............................................................ 96 7.3.2.5 Cost .............................................................................. 97

7.3.3 Alternative 2A: Modifying Criteria ............................................... 98 7.3.3.1 State Acceptance .......................................................... 98 7.3.3.2 Public Acceptance ........................................................ 98

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TABLE OF CONTENTS (cont.)

Page 7.4 Detailed Analysis of Alternative 2B – In Mine Precipitation in Bleakhouse

Mine Pool ............................................................................................... 98 7.4.1 Alternative 2B: Threshold Criteria Evaluation ............................. 99

7.4.1.1 Overall Protectiveness of Human Health and the Environment ................................................................ 99

7.4.1.2 Compliance with ARARs ............................................... 99 7.4.2 Alternative 2B: Primary Balancing Criteria Evaluation .............. 100

7.4.2.1 Long-Term Effectiveness and Permanence ................ 100 7.4.2.2 Short-Term Effectiveness ........................................... 101 7.4.2.3 Reduction of TMV through Treatment ......................... 101 7.4.2.4 Implementability .......................................................... 102 7.4.2.5 Cost ............................................................................ 102

7.4.3 Alternative 2B: Modifying Criteria ............................................. 103 7.4.3.1 State Acceptance ........................................................ 103 7.4.3.2 Public Acceptance ...................................................... 103

7.5 Detailed Analysis of Alternative 2C – IRM Reaction Wall in Belden ...... 103 7.5.1 Alternative 2C: Threshold Criteria Evaluation........................... 104

7.5.1.1 Overall Protectiveness of Human Health and the Environment .............................................................. 104

7.5.1.2 Compliance with ARARs ............................................. 104 7.5.2 Alternative 2C: Primary Balancing Criteria Evaluation .............. 105

7.5.2.1 Long-Term Effectiveness and Permanence ................ 105 7.5.2.2 Short-Term Effectiveness ........................................... 106 7.5.2.3 Reduction of TMV through Treatment ......................... 107 7.5.2.4 Implementability .......................................................... 107 7.5.2.5 Cost ............................................................................ 107

7.5.3 Alternative 2C: Modifying Criteria............................................. 108 7.5.3.1 State Acceptance ........................................................ 108 7.5.3.2 Public Acceptance ...................................................... 108

7.6 Detailed Analysis of Alternative 3A: Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite .......... 108 7.6.1 Alternative 3A: Threshold Criteria Evaluation ........................... 109

7.6.1.1 Overall Protectiveness of Human Health and the Environment .............................................................. 109

7.6.1.2 Compliance with ARARs ............................................. 109 7.6.1.3 Alternative 3A: Primary Balancing Criteria

Evaluation .................................................................. 110 7.6.1.4 Long-Term Effectiveness and Permanence ................ 110 7.6.1.5 Short-Term Effectiveness ........................................... 111 7.6.1.6 Reduction of TMV through Treatment ......................... 112 7.6.1.7 Implementability .......................................................... 112 7.6.1.8 Cost ............................................................................ 113

7.6.2 Alternative 3A: Modifying Criteria ............................................. 113 7.6.2.1 State Acceptance ........................................................ 113 7.6.2.2 Public Acceptance ...................................................... 113

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TABLE OF CONTENTS (cont.)

Page 7.7 Detailed Analysis of Alternative 3B: Excavate, Transport and

Dispose of All Waste Rock onsite ......................................................... 113 7.7.1 Alternative 3B: Threshold Criteria Evaluation ........................... 114

7.7.1.1 Overall Protectiveness of Human Health and the Environment .............................................................. 115

7.7.1.2 Compliance with ARARs ............................................. 115 7.7.2 Alternative 3B: Primary Balancing Criteria Evaluation .............. 115

7.7.2.1 Long-Term Effectiveness and Permanence ................ 116 7.7.2.2 Short-Term Effectiveness ........................................... 116 7.7.2.3 Reduction of TMV through Treatment ......................... 118 7.7.2.4 Implementability .......................................................... 118 7.7.2.5 Cost ............................................................................ 118

7.7.3 Alternative 3B: Modifying Criteria ............................................. 119 7.7.3.1 State Acceptance ........................................................ 119 7.7.3.2 Public Acceptance ...................................................... 119

7.8 Detailed Analysis of Alternative 3C: Excavate, Transport and Dispose of All Waste Rock Offsite ........................................................ 119 7.8.1 Alternative 3C: Threshold Criteria Evaluation........................... 119

7.8.1.1 Overall Protectiveness of Human Health and the Environment .............................................................. 120

7.8.1.2 Compliance with ARARs ............................................. 120 7.8.2 Alternative 3C: Primary Balancing Criteria Evaluation .............. 120

7.8.2.1 Long-Term Effectiveness and Permanence ................ 121 7.8.2.2 Short-Term Effectiveness ........................................... 121 7.8.2.3 Reduction of TMV through Treatment ......................... 122 7.8.2.4 Implementability .......................................................... 123 7.8.2.5 Cost ............................................................................ 123

7.8.3 Alternative 3C: Modifying Criteria............................................. 123 7.8.3.1 State Acceptance ........................................................ 124 7.8.3.2 Public Acceptance ...................................................... 124

7.9 Detailed Analysis of Alternative 4A: Groundwater Collection and Treatment, OTP/Rex Flats ................................................................... 124 7.9.1 Alternative 4A: Threshold Criteria Evaluation ........................... 124

7.9.1.1 Overall Protectiveness of Human Health and the Environment .............................................................. 126

7.9.1.2 Compliance with ARARs ............................................. 126 7.9.2 Alternative 4A: Primary Balancing Criteria Evaluation .............. 126

7.9.2.1 Long-Term Effectiveness and Permanence ................ 127 7.9.2.2 Short-Term Effectiveness ........................................... 127 7.9.2.3 Reduction of TMV through Treatment ......................... 128 7.9.2.4 Implementability .......................................................... 128 7.9.2.5 Cost ............................................................................ 129

7.9.3 Alternative 4A: Modifying Criteria ............................................. 129 7.9.3.1 State Acceptance ........................................................ 129 7.9.3.2 Public Acceptance ...................................................... 129

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TABLE OF CONTENTS (cont.)

Page 7.10 Detailed Analysis of Alternative 4B – IRM Reaction Wall at

OTP/Rex Flats ..................................................................................... 129 7.10.1 Alternative 4B: Threshold Criteria Evaluation ........................... 130

7.10.1.1 Overall Protectiveness of Human Health and the Environment .............................................................. 130

7.10.1.2 Compliance with ARARs ............................................. 130 7.10.2 Alternative 4B: Primary Balancing Criteria Evaluation .............. 131

7.10.2.1 Long-Term Effectiveness and Permanence ................ 131 7.10.2.2 Short-Term Effectiveness ........................................... 132 7.10.2.3 Reduction of TMV through Treatment ......................... 133 7.10.2.4 Implementability .......................................................... 133 7.10.2.5 Cost ............................................................................ 133

7.10.3 Alternative 4B: Modifying Criteria ............................................. 134 7.10.3.1 State Acceptance ........................................................ 134 7.10.3.2 Public Acceptance ...................................................... 134

COMPARATIVE ANALYSIS OF ALTERNATIVES ......................................... 135 8.08.1 Overall Protection of Human Health ..................................................... 135 8.2 Overall Protection of the Environment .................................................. 135 8.3 Compliance with ARARs and TBCs...................................................... 136 8.4 Long-Term Effectiveness and Permanence .......................................... 136

8.4.1 Magnitude of Residual Risks .................................................... 136 8.4.2 Adequacy and Reliability of Engineering Controls ..................... 136

8.5 Short-Term Effectiveness ..................................................................... 137 8.5.1 Risks to the Local Communities ................................................ 137 8.5.2 Potential Risks to Workers ........................................................ 137 8.5.3 Potential Environmental Impacts............................................... 137 8.5.4 Time Until RAOs Are Achieved ................................................. 138

8.6 Reduction of Toxicity, Mobility, or Volume through Treatment .............. 138 8.7 Implementability ................................................................................... 138

8.7.1 Technical Feasibility ................................................................. 138 8.7.2 Administrative Implementability ................................................ 138 8.7.3 Availability of Labor and Materials ............................................ 139

8.8 Cost ..................................................................................................... 139 8.9 Comparative Analysis Summary .......................................................... 139

REFERENCES ................................................................................................ 144 9.0

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LIST OF TABLES

Page

Table 1 Summary of Water Quality Standard Equations by Segment ............................. 9 Table 2 Snow Pack and Segment 5a Spring Metal Concentrations .............................. 16 Table 3 E-3 Metal Loading ........................................................................................... 20 Table 4 Segment 5a Zinc Loading ................................................................................ 23 Table 5 Lower Reach of Segment 5a ........................................................................... 25 Table 6 Segment 5b Zinc Loading ................................................................................ 29 Table 7 Segment 5c Zinc Loading ................................................................................ 32 Table 8 Spring Zinc Load Summary, Segment 5 .......................................................... 34 Table 9 Groundwater Quality in the Belden Area .......................................................... 36 Table 10 Water Quality in the Mill Level ....................................................................... 41 Table 11 Railroad Ballast Sample Results .................................................................... 42 Table 12 Waste Rock Pile Information.......................................................................... 45 Table 13 Waste Rock Pile Mean Metal Concentrations ................................................ 46 Table 14 Waste Rock Pile Leachant Volume Estimates ............................................... 51 Table 15 Waste Rock Zinc Source Load Estimates ...................................................... 52 Table 16 Rock Creek Groundwater Results ................................................................. 53 Table 17 OTP Ditch Seep............................................................................................. 56 Table 18 Zinc Source Load Estimates, Spring, Segment 5a ......................................... 57 Table 19 Potential Federal and State Chemical-Specific ARARS ................................. 61 Table 20 Potential Federal, State, and Local Location-Specific ARARs........................ 65 Table 21 Potential Federal and State Action-Specific ARARs ...................................... 70 Table 22 List of Alternatives ......................................................................................... 81 Table 23 Alternative 1 Estimated Costs ........................................................................ 91 Table 24 Alternative 2A Estimated Costs ..................................................................... 98 Table 25 Alternative 2B Estimated Costs ................................................................... 102 Table 26 Alternative 2C Estimated Costs ................................................................... 108 Table 27 Alternative 3A Estimated Costs ................................................................... 113 Table 28 Alternative 3B Estimated Costs ................................................................... 118 Table 29 Alternative 3C Estimated Costs ................................................................... 123 Table 30 Alternative 4A Estimated Costs ................................................................... 129 Table 31 Alternative 4B Estimated Costs ................................................................... 133 Table 32 Comparative Analysis of Remedial Alternatives with Respect to

Two Threshold and Five Balancing Criteria .......................................................... 141

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LIST OF FIGURES

Page

Figure 1 Eagle Mine Site ................................................................................................ 2 Figure 2 Surface Water Monitoring Locations and Eagle River Basin Segments ............ 9 Figure 3 Dissolved Zinc Concentrations (mg/L) in the Eagle River Compared to Water

Quality Standards by Segment ............................................................................... 13 Figure 4 Dissolved Cadmium Concentrations (mg/L) in the Eagle River Compared to

Water Quality Standards by Segment .................................................................... 14 Figure 5 Dissolved Copper Concentrations (mg/L) in the Eagle River Compared to

Water Quality Standards by Segment .................................................................... 15 Figure 6 Spring Zinc Loading Distribution in Eagle River Segments with Snow Pack ... 19 Figure 7 Segment 5a Spring Average Loading Distribution .......................................... 22 Figure 8 Segment 5b Spring Average Loading Distribution .......................................... 28 Figure 9 Segment 5c Spring Average Loading Distribution........................................... 31 Figure 10 Belden Area Groundwater Monitoring Locations ........................................... 37 Figure 11 Belden Area Groundwater Elevations for the Spring 2009 and

Spring 2010 ............................................................................................................ 38 Figure 12 Belden Area Water Levels Versus Dissolved Zinc Concentrations

in the Eagle River, Spring 2009 and Spring 2010 ................................................... 39 Figure 13 Cross Section at Historic Tunnel and Mill Level ............................................ 40 Figure 14 Eagle River Conductance Survey, Belden Area, Spring 2009 ....................... 43 Figure 15 Eagle River Conductance Survey, Belden Area, Spring 2010 ....................... 44 Figure 16 Location of Waste Rock Piles (from Dames & Moore 1995b) ....................... 47 Figure 17 Rock Creek Plan View .................................................................................. 54 Figure 18 Dissolved Zinc Concentration, Station T-10: Rock Creek ............................ 55 Figure 19 Dissolved Zinc Concentrations along Rex Flats and OTP ............................. 57 Figure 20 Proposed Trench Location (Alternatives 2A and 2C) in Belden .................... 93 Figure 21 Proposed Interceptor Trenches (Alternatives 4A and 4B) at the

OTP/Rex Flats...................................................................................................... 125

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LIST OF APPENDICES Appendix A Excerpt of the Basis and Purpose of the Eagle Mine, Eagle River Basin—

Metals Standards or Water Quality Standards (WQS) Appendix B Surface Water Sampling 2009 – 2012 Appendix C Annual Loading and Load Reduction C-1 Yearly Average Zinc Load Calculations and Zinc Load Reduction

Calculations C-2 Yearly Average Cadmium Load Calculations and Cadmium Load

Reduction Calculations C-3 Yearly Average Copper Load Calculations and Copper Load

Reduction Calculations Appendix D Segment Loading D-1 Zinc Loading (lbs/day) Analysis by Segment D-2 Cadmium Loading (lbs/day) Analysis by Segment D-3 Copper Loading (lbs/day) Analysis by Segment Appendix E Photos Appendix F Cost Estimates

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LIST OF ACRONYMS

ARARs Applicable or relevant and appropriate requirements ARD acid rock drainage reaction BMPs best management practices CBS CBS Operations Inc. CDPHE Colorado Department of Public Health and Environment CERCLA Comprehensive Environmental Response, Compensation, and

Liability Act CFS cubic feet per second CTP Consolidated Tailing Pile DER Data Evaluation Report EPA U.S. Environmental Protection Agency FFS Focused Feasibility Study FSA Feasibility Study Addendum GRA general response action ICs Institutional controls IRM iron-rich material lbs/day pounds per day MDD Mine drawdown mg/L milligrams per liter MSL mean sea level NCP National Contingency Plan NPDES National Pollution Discharge Elimination System O&M Operation and Maintenance OSHA Occupational Safety and Health Administration OTP Old Tailing Pile PPE personal protective equipment PRB permeable reaction barrier RAOs remedial action objective ROD Record of Decision SARA Superfund Amendments and Reauthorization Act SHPO State Historic Preservation Office SPLP synthetic precipitation leaching procedure TBC to be considered TMV toxicity, mobility, or volume UGDT Upgradient Groundwater Diversion Trench USGS United States Geological Survey WQS Water Quality Standards WR-8 Waste Rock Pile No. 8 WTP Water treatment plant

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Focused Feasibility Study

Eagle Mine Site

This Focused Feasibility Study (FFS) evaluates alternatives that are designed to achieve Water Quality Standards (WQS) in the Eagle River as it passes through the Eagle Mine Superfund Site in Eagle County, Colorado (Site) and identifies the preferred alternative. This FFS was prepared by NewFields on behalf of CBS Operations Inc. (CBS).

INTRODUCTION 1.0

Remedial actions performed in the 1990s largely addressed metal loading from the mine tailings located at the Consolidated Tailings Pile (CTP), Old Tailings Pile (OTP), and Rex Flats (Figure 1). With remediation of the large tailings sites, the Eagle River typically meets water quality standards as it flows through the Site, except in March and April, when copper, cadmium, and zinc concentrations can be elevated. Recent studies indicate that the majority of the metals loading to the Eagle River in this time period impacts Segment 5a where the river passes the inactive Eagle mine and underground mill at Belden. The alternatives evaluated in this Focused Feasibility Study (FFS) are those that have the potential to control and reduce metal loading in Segment 5a of the Eagle River in March and April each year.

1.1 SITE LOCATION AND MINE HISTORY

The Site is located in Eagle County, Colorado between Minturn and Red Cliff and is bordered by the White River National Forest to the south and west. The Eagle River and two of its principal tributaries, Cross Creek and Rock Creek, flow through the Site (Figure 1). The Site includes the underground mill and mine workings of the Eagle Mine along with associated waste rock piles and tailings. Many mines not associated with the Eagle Mine are included within the Site.

Mining began in this area in 1879 and 1880 with the establishment of the Belden, Black Iron, and Little Chief mines near Gilman, and the Horn Silver and Wyoming Valley mine near Red Cliff. In 1905 a mill was built at Gilman by the Pittsburg Gold and Zinc Company to roast and separate ore. By 1916, the Empire Zinc Company of Colorado (a subsidiary of the New Jersey Zinc Company) completed the consolidation of the principal mines into what is known as the Eagle Mine. Large-scale lead and zinc mining in Colorado ended in 1977 when the Eagle Mine closed. The Eagle Mine was the largest producer of lead and zinc in Colorado at one time.

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Figure 1 Eagle Mine Site

1.2 REMEDIATION HISTORY

The Site was listed on the National Priorities List in 1986 due to the potential to contribute excess metals loads to the Eagle River. The cleanup of the Site began in

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1988 under the terms of the Consent Decree, Order, Judgment and Reference to the Special Master for Civil Action No. 83-C-2387 (D. Colorado), Remedial Action Plan (CD/RAP). Major elements of the State-led cleanup under the CD/RAP include the following.

• Installation of eight concrete bulkheads in the lower mine adits of the Eagle Mine and in the workings of the Tip Top and Ben Butler mines located upstream of Belden. The adit bulkheads were constructed to prevent the discharge of mine water and to submerge the sulfide ore bodies, thereby reducing the amount of oxygen that drives the acid rock drainage reaction (ARD). The first bulkheads were installed in 1986 as the mine filled with water.

• Removal of the tailings at the OTP and Rex Flats and material at the Roaster Pile and consolidating these materials at the Consolidated Tailing Pile (CTP).

• Reclamation of the OTP, Rex Flats, Roaster Pile, and CTP areas.

• Construction of diversion channels in August 1990 to conduct storm-water runoff around waste rock piles WP-1 through WP-8 and WP-11 in and around Gilman, Colorado. The primary purpose of this diversion was to protect the piles from extensive erosion during runoff events (Dames & Moore 1994).

• Collection via interception trenches and pumping of groundwater from the CTP area back into the mine.

• Construction of a 48-inch diameter culvert in the lower 660 feet of Rock Creek in 1989 to carry flow past waste rock to the river.

• Construction of the Upgradient Groundwater Diversion Trench (UGDT) in 1989 just west of the CTP. This system was designed and installed to reduce groundwater recharge by diverting clean upgradient groundwater around the CTP to the Maloit Park wetlands.

The Eagle Mine filled and began seeping in the Rock Creek area in September 1989. In 1990, the CD/RAP was amended to include the addition of a mine seep collection system and a water treatment plant (WTP). The collection basins were located where mine water seepage was identified in the Belden and Rock Creek areas. Rock Creek now contains seep collection basins at seep S-5, seep S-6, seep S-RF, and seep S-7. The Belden area contains two seep collection basins: Adit 140 (Newhouse level) and the Tip Top portal.

To reduce seepage from the mine, a system was put in place in 1992 whereby mine water is gravity-drained from the Adit No. 5 bulkhead (known as the Mine Drawdown or “MDD”). The MDD pipeline carries mine water from Adit No. 5 downhill 500 feet to the main pipeline at the base of Rock Creek. An electromagnetic flow meter measures the flow rate in the pipeline at the discharge end near the concrete vault at the bottom of Rock Creek (MDD vault). Mine water and collected seepage are conveyed to the WTP by means of a 15,000 foot pipeline. The main pipeline consists of four sections: the section from Tip Top mine through Belden to Rock Creek, the section from Rock Creek

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to Manhole 1 at the upstream end of the trestle, the trestle section and 8-inch bypass at Rex Flats, and the section from the trestle to the WTP. The trestle is not being used in favor of the newer, higher velocity 8-inch bypass.

Mine drainage, mine seepage, and runoff from Gilman are piped to two surge ponds prior to treatment. Groundwater collected at two french drains at the CTP is also piped to the ponds. The surge pond water is pumped to the WTP where it is treated by conventional lime precipitation to remove zinc and other metals prior to discharge to the Eagle River. Sludge from the process is disposed of in a sludge pond on the CTP.

In 1990, the U.S. Environmental Protection Agency (EPA) commissioned a Feasibility Study Addendum (FSA) to address issues that had arisen since the original cleanup. The FSA (MK 1992) was completed in 1992, and in 1993 the resulting EPA Record of Decision (ROD) required additional cleanup. The 1996 Final Statement of Work - Part A (Appendix B) for the Operable Unit No. 1 Partial Consent Decree, Civil Action No. 95-N-2360 (D. Colorado) (CD/SOW) contained the following requirements.

• Additional criteria for determining vegetation success.

• Diversion of clean groundwater around the CTP.

• Extension of the 48-inch diameter Rock Creek culvert 800 feet upstream to just above the Adit No. 8 road.

• Collection and treatment of Rock Creek groundwater. In June 1993, a siphon was installed that collects Rock Creek groundwater that is piped to the WTP for treatment.

• Remediation and revegetation of the Maloit Park wetlands.

• Additional evaluation of the waste rock piles.

• Evaluation, improvement, and continued pumping and treatment of CTP groundwater from the extraction trenches.

• Establishment of site-specific, biological based water quality standards for the river.

With the major remedial activities completed, the Site transitioned into the Operation and Maintenance (O&M) phase in 1999. Since that time, the following major items have been completed.

• The Liberty No. 4 well began pumping in 2000, intercepting clean water recharge to the Eagle Mine and diverting this water to Turkey Creek.

• A collection ditch was constructed in 2001 that diverts snowmelt from waste rock pile No. 8 (WP-8) to the mine pool via the Fancy Shaft. In 2007, a second collection system was constructed that captures WP-8 runoff before it enters Rock Creek and diverts this water to the Seep 7 catchment basin for treatment at the WTP.

• The vegetation on the CTP, Rex Flats, and OTP was approved in 2006.

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• Waste rock and concentrates in WP-14 in Belden were excavated in 2006 and 2009 and placed in the Temp Cell on the CTP.

• A Belden groundwater extraction system consisting of two 12-volt submersible pumps in two wells was operated in 2007 and 2008 on a daily basis when the solar panels received direct sun. Operation of the two wells was discontinued in the summer of 2008 when the system was vandalized.

• The Copper Tipple groundwater collection trench (Copper Tipple Trench) was installed in Belden in 2007.

• An 8-inch HDPE pipeline that bypasses the trestle through Rex Flats was constructed in January 2010.

1.3 REMAINING SOURCES

With the remediation of the large tailings piles in the early 1990s, the water quality of the Eagle River improved dramatically. Surface water quality has largely become a function of the amount of groundwater recharge entering the river from the remaining subsurface sources and the available dilution in the river and its tributaries. The largest of the remaining mine-related sources that are on the Site are:

• Mine pool • Belden area • Rock Creek canyon • OTP and Rex Flats • CTP.

The mine pool is the single largest source of mine-related metals. The extraction and treatment of 100-300 gpm of mine water from the pool (MDD) controls the water level between elevation 8436 and 8500 ft MSL. The mine pool level is purposely held in this range to submerge some of the remaining lead and zinc ore to reduce the ARD (acid rock drainage); however, if the pool level exceeds 8520 ft MSL, seeps will develop in Rock Creek canyon that can contribute metals to the Eagle River. Mine pool seepage at normal pool levels is small and has little effect on the river. A recent sample of mine water from the top of the pool contained approximately 18 mg/L zinc.

Belden (Figure 1) is the site of the old Iron Mask mill, the New Jersey Zinc underground mill, the railroad siding, and zinc/lead ore processing and railcar loading facilities. The groundwater in the Belden area contains metals leached from waste rock, mill concentrates, and railroad ballast. The leaching process has resulted in zinc concentrations in groundwater of 200 to 900 mg/L. Groundwater recharge to the river is not significant during most of the year; however, significant impacts have been observed during the spring when the winter snowpack melts and infiltration is active.

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Rock Creek canyon enters the Eagle River downstream of the Belden area (Figure 1). Lower Rock Creek is confined to a culvert to physically separate the surface water from groundwater within the Rock Creek canyon. The groundwater in the narrow canyon near the mine contains metals because it is recharged by seepage from three waste rock piles and a landslide deposit in Gilman, and mine pool leakage. Zinc concentrations in groundwater range from 50 to 200 mg/L. Groundwater load contributions from Rock Creek during the spring are less than half of what has been observed from Belden.

Two former tailings sites, Rex Flats and the OTP, bracket the river about 1.5 miles downstream of Belden (Figure 1). Approximately 150,000 tons of tailings were removed from the 20-acre Rex Flats in 1989. Zinc concentrations in Rex Flats wells range up to 38 mg/L (ERM 2007b). Most of the tailings were removed from the 38-acre OTP (Figure 1) by 1990 and moved to the CTP. Zinc concentrations in groundwater samples from the OTP wells range up to 480 mg/L (ERM 2007b). Groundwater movement from the two former tailings sites to the river is slow due to lack of gradient and low permeability of glacial sediments and the impact on the river is believed to be minor.

The CTP (Figure 1) was capped in 1991. The 69 acre repository is founded on unconsolidated alluvial and glacial units that receive most of their recharge from the topographic high to the southwest. Groundwater discharges from shallow units below the tailings, entering the Eagle River just upstream and at the confluence with Cross Creek (Figure 1). The flow rate computed using a numerical model and the basin-wide analysis of stream flow and precipitation is 25-30 gpm, varying seasonally (Dames & Moore 1986). This estimate has been corroborated with annual metal loading evaluations. Samples taken in 2011 indicated that the groundwater contains zinc concentrations in the 23-44 mg/L range. Two groundwater extraction trenches intercept much of the groundwater that would ordinarily flow to the river and pump it to the WTP for treatment. This system has been in operation since 1988 and with it, the impact on water quality in the river has proven to be small.

1.4 FFS REGULATORY BACKGROUND

EPA and the Colorado Department of Public Health and Environment (CDPHE) developed a draft Statement of Work in 2009 detailing the requirements and schedule for the development of the FFS. CBS submitted a Focused Feasibility Study Plan by letter dated February 18, 2009. Following a public meeting with the Stakeholders on August 7, 2009, a second deliverable, the Preliminary List of Alternatives, was submitted on August 28, 2009 and approved by EPA and CDPHE on February 2, 2010. CDPHE received comments on the scope of the FFS from the Eagle River Water Users (AMEC Earth & Environment 2009) and the ERWC – Eagle Mine Ltd (2009). CBS submitted a draft FFS dated April 23, 2010. Agency and stakeholder comments were received on June 8, 2010 and were taken into consideration in a November 1, 2010 draft. EPA and CDPHE provided formal comments on the revised draft FFS on March 14, 2011.

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NewFields incorporated those comments in a July 7, 2011 version of the FFS. The July 2011 version of the FFS was provided to the Stakeholders by CDPHE and EPA, and the Stakeholders provided comments to the Agencies. EPA provided additional comments on July 12, 2012 and provided stakeholder comments to be addressed in the document on July 13, 2012. CDPHE provided additional comments on August 17, 2012. These comments were incorporated in a response letter dated November 15, 2012 and in this document. Once the FFS is approved and EPA finalizes an OU-1 Amended Record of Decision, EPA and CBS will negotiate a new Consent Decree.

1.5 ORGANIZATION OF THE DOCUMENT

The organization of this FFS is as follows.

• Section 1 provides a history of actions taken at the Site and the WQS used for comparisons in the FFS.

• Section 2 describes the water quality in the Eagle River and some of its tributaries with respect to cadmium, copper, and zinc chronic WQSs.

• Section 3 quantifies metal loading to the Eagle River, primarily in terms of zinc.

• Section 4 describes the some of the sources in Segment 5a that contribute metals to the Eagle River.

• Section 5 presents the remedial action objectives (RAOs) and the applicable or relevant and appropriate requirements (ARARs) for development of remedial alternatives.

• Section 6 presents the general response actions and process options. The process options are combined to formulate the alternatives.

• Section 7 presents a description of each remedial alternative and the detailed analysis of the remedial alternatives using the nine criteria prescribed by the National Contingency Plan (NCP; 40 CFR Section 300 et. seq.).

• Section 8 presents the comparative analysis using seven of the nine criteria, a summary of the analysis, and the preferred remedy.

• Section 9 presents the references cited in this FFS.

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WATER QUALITY 2.0

In March and April, prior to the major snowmelt that generates flows in the Eagle River greater than 150 cubic feet per second (cfs), cadmium, copper, and zinc concentrations in the river can be elevated and at times exceed the applicable chronic WQS. For the remainder of the year, the metals concentrations are at or below the applicable WQS. This section describes water quality with respect to cadmium, copper, and zinc. Figure 2 presents the Eagle River segments discussed in the report and the relation to surface water sampling locations.

2.1 SITE-SPECIFIC WATER QUALITY CRITERIA

As the Eagle River Segments 5 and 7 were identified by the Colorado Water Quality Control Division (the Commission) as being “impacted by historical mining activities at the Eagle Mine Superfund Site” the river standards within these segments have been modified from the State-wide table value standards (TVS). Originally the site-specific standards were set in the 1996 CD/SOW (Part B Appendix B) which contained provisions for the “Eagle River Biological Criteria Approach” and were listed as Temporary Modifications for these segments. This process was abandoned in 2003 and ultimately replaced by a program to develop site-specific water quality standards for the Eagle River and its tributaries near the Site. Through a cooperative process involving all major Stakeholders, WQS were developed for the Commission that are protective of the aquatic community (macroinvertebrates and brown trout) that was expected in Segment 5 of the Eagle River and Cross Creek. Appendix A presents the Basis and Purpose of the WQS as presented by the Commission for the rulemaking. The WQS were put in place in January 1, 2009 replacing the Temporary Modifications that were in effect at the time.

Table 1 (presented on Figure 2) presents the equations for both acute and chronic exposure and timing, if applicable, for the WQS for zinc, copper and cadmium in Segments 5 and 7 with the TVS for comparison. Chronic WQSs, more stringent than acute WQSs, have been selected as the reference point for an “exceedance” of the WQS in this document. However, it should be noted that this is a conservative assessment as the Colorado Water Quality Control Division's assessment methodologies to interpret the water quality data uses the 85th percentile of the data set to determine attainment. This approach means that 15 percent of the data points can exceed the standard, and the segment would still be considered in attainment of the standards.

The following discussion presents the surface water quality by Segment. Appendix B presents the hardness and dissolved cadmium, copper, and zinc concentrations collected since January 1, 2009 by CBS and others. Each sample is compared to its corresponding WQS as calculated on a sample date basis using the appropriate equations from Table 1 and the measured hardness for the sampling date. Concentrations which exceed the calculated WQS are bolded and italicized as well as shaded.

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0 1,400 2,800 4,200 5,600700

Feet

0 5,000 10,000 15,000 20,0002,500

Feet

Figure 2Surface Water Monitoring Locations

and Eagle River Basin Segments

Table 1 Summary of Water Quality Standard Equations by Segment

Equation Segment

2 5a 5b 5c 7b

Zin

c

Rainbow Equations

A:0.978*e 0.8537[ln(hardness)]+2.1302

C:0.986*e 0.8537[ln(hardness)]+1.9593

All Year Jan 1 � Apr 30

Jan 1 � Apr 30

Sculpin Equations

A:0.978*e 0.8537[ln(hardness)]+1.4189

C:0.986*e 0.8537[ln(hardness)]+1.2481

May 1 � Dec 30

All Year May 1 � Dec 30

Table Value Standard (TVS)

A:0.978*e 0.9094[ln(hardness)]+0.9095

C:0.986*e 0.9094[ln(hardness)]+0.6235

Sculpin:0.986*e 2.140[ln(hardness)]-5.084

[Sculpin equation where mottled sculpin are

expected and hardness is less than 102 CaCO3]

All Year

Co

pp

er

tubifex equations

A:0.96*e 0.9801[ln(hardness)] � 1.1073

C:0.96*e 0.5897[ln(hardness)] � 0.0053

All Year

Ephoron equations

A:0.96*e 0.9801[ln(hardness)]-1.5865

C:0.96*e 0.5897[ln(hardness)]-0.4845

All Year All Year All Year

Table Value Standard (TVS)

A:0.96*e 0.9422[ln(hardness)]-1.7408

C:0.96*e 0.8545[ln(hardness)]-1.7428

All Year

Cad

miu

m

Site-specific A:TVS C:(1.101672-[(ln(hardness)*(0.041838)])*

e(0.7998 [ln( hardness)]-3.1725)

All Year All Year All Year All Year

Table Value Standard (TVS) A:(1.136672-[ln(hardness)*(0.041838)])*

e(0.9151[ln(hardness)]-3.1485)

Trout:(1.136672-[ln(hardness)*(0.041838)])*

e(0.9151[ln(hardness)]-3.6236)

C:(1.101672-[(ln(hardness)*(0.041838)])*

e(0.7998 [ln( hardness)]-4.4451)

All Year

A- Acute C Chronic

Legend"/ SW_Locations

Segment 2

Segment 5a

Segment 5b

Segment 5c

Segment 7a

Segment 7b

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2.1.1 Segment 2

Segment 2 extends from the river’s source to the compressor house bridge at Belden. Segment 2 represents upstream water quality for the Site and the water chemistry data from station E-3 (Figure 2) is used as the monitoring point. Extensive data for the station are available, and water chemistry is well characterized. The WQS for Segment 2 that have been adopted by the Commission are the Table Value Standards (TVS) or standards protective of the most sensitive aquatic species that may have existed under pre-mining conditions.

Appendix B presents results for samples collected at station E-3 since 2009. Cadmium, copper and zinc concentrations occasionally exceed the TVS for Segment 2 during spring when the hardness concentrations drop with spring runoff, and metal concentrations rise due to runoff and seepage from natural mineralization and historic mines in this segment between Red Cliff and Gilman. During the rest of the year, the WQS are usually met.

2.1.2 Segment 5a

Segment 5a is downstream of Segment 2 and extends from the compressor house bridge at Belden downstream to a point immediately above the Highway 24 Bridge near Tigiwon Road. In terms of sampling stations, Segment 5a can be generally defined as the segment between monitoring stations E-3 and E-12A and includes intermediate stations E-5, E-10, and E-11 (see Figure 2 for locations). The Eagle River receives runoff from waste rock piles and groundwater seepage from several mines in this segment including the large Eagle mine at Belden. Rock Creek tributary joins the river just below station E-10. Extensive data are available for Segment 5a and water chemistry is well characterized; Appendix B presents results for samples from E-10 and E-12A collected since 2009.

With respect to WQS, it was determined by the Commission in 2008 that the rainbow trout equations for zinc and the tubifex equations for copper were applicable to Segment 5a for the entire year (see Appendix A for full basis and purpose).

Cadmium and zinc concentrations variably exceed the WQS for Segment 5a at stations E-10 and E-12A during some portion of the spring, especially when there is heavy spring runoff from an above-average winter snowpack. During the rest of the year, and all year during low-snowpack years, WQS are usually met.

While copper did not exceed WQS for Segment 5a at either station, the concentrations would exceed the Ephoron standard that is applied to other stations at the Site. An attainability analysis was conducted in 2008 which showed that it is not feasible to reduce copper loads to a level that would result in attainment of the recalculated copper standard (the Ephoron standard). The majority of the copper load originates from

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upstream sources that cannot be controlled at the site. A recalculated standard (using tubifex worms) was applied to Segment 5a.

2.1.3 Segment 5b

Segment 5b extends from a point immediately above the Highway 24 bridge near Tigiwon Road to a point immediately above the confluence with Martin Creek. Monitoring station E-15 in Segment 5b is the farthest downstream station currently monitored and Appendix B presents the monitoring data collected for E-15 since 2009.

With respect to WQS, it was determined by the Commission that the rainbow equations were applicable to Segment 5b from January 1 through April 30 and the sculpin equations were applied from May 1 through December 31 (see Appendix A for full basis and purpose). The recalculated copper standard was deemed attainable by the Commission and was applied to Segment 5b. The revised chronic cadmium equation applies to Segment 5b.

The E-15 sample data demonstrate that cadmium, copper, and zinc concentrations typically meet WQS with a few exceptions since 2009.

2.1.4 Segment 5c

Segment 5c extends from a point immediately above the confluence with Martin Creek to the confluence with Gore Creek. Monitoring station E-22 is the compliance station in this segment. With respect to WQS, the sculpin equations were applied by the Commission to segment 5c year-round for zinc. The recalculated copper standard was deemed attainable by the Commission as was the revised chronic cadmium equation; both were applied to Segment 5c. See Appendix A for full basis and purpose by the Commission.

Appendix B presents the monitoring data collected for E-22 since 2009. The data in Appendix B is supplemented with data provided by the Eagle River Water Sanitation District and the Eagle River Water Council. The E-22 sample data demonstrate that cadmium, copper, or zinc concentrations occasionally exceed WQS during the spring. Segment 5c (E-22) exceeds the zinc WQS more often than upstream Segment 5b (E-15) because the WQS in Segment 5c are more conservative in the spring (sculpin vs. rainbow equations).

2.1.5 Segment 7b

Segment 7b is the lower segment of Cross Creek, extending from a point immediately below the Minturn Middle School to the confluence with the Eagle River in Segment 5b. Segment 7b water quality (Cross Creek) is monitored at station T-18 located just upstream of the confluence with the Eagle River. Flows are measured at the Highway

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24 culvert (Figure 2) or at USGS gauge 09065100 downstream from the school. With respect to WQS, it was determined by the Commission that the rainbow equations were applicable to Segment 7b from January 1 through April 30 and the sculpin equations were applicable from May 1 through December 31. The recalculated copper standard was deemed attainable by the Commission as was the revised chronic cadmium equation; both were applied to Segment 7b.

Appendix B presents the monitoring data collected for T-18 since 2009. Zinc concentrations rise in March before the onset of high flow; however, zinc concentrations typically meet the Spring WQS. The copper WQS is occasionally exceeded in the fall or in the spring.

2.2 WATER QUALITY DISTRIBUTION WITHIN AND BETWEEN SEGMENTS

Higher dissolved zinc concentrations are observed in the river during snowmelt periods in March and April. By May each year, warm temperatures generate snowmelt in the upper Eagle River basin above the Site and a large increase in stream flow occurs with peak flows typically occurring in May or June. The increased stream flow results in lower metal concentrations.

Graphical representation of concentration data for dissolved zinc, cadmium, and copper are provided in Figure 3, Figure 4, and Figure 5, respectively. These plots show concentrations for the Eagle River stations for each year over the 2009 to 2012 period. The concentrations are compared against WQS calculated for each station using the Spring WQS equation and the average hardness for the low flow samples (<100 cfs) collected during the time period (2009-2012)1. These figures illustrate how the WQS can vary, from a change in the underlying equation changes or due to the overall increase in hardness from upstream to downstream. The cadmium equation is constant in Segments 5a, 5b, and 5c, but the cadmium WQS increases downstream due to the increase in hardness. The WQS trend for zinc and copper decreases downstream due to the use of more sensitive species in the WQS.

Metal concentrations trends seen in the figures indicate that the Spring sampling events experience higher metal concentrations than fall or winter with the higher concentrations detected in Segment 5a. One potential exception is copper which at times is detected at concentrations in Segment 2 (upstream segment) as high as in Segment 5a.

The higher metal concentrations appear to correlate with larger than normal snow packs. Table 2 presents the snow pack as a percentage of normal as of April 30 of the year and the range of dissolved metal concentrations in Segment 5a (as measured in Eagle River stations E-5, E-10, E-11 and E-12A).

1 The standardization of the hardness for Figure 3, Figure 4, and Figure 5 may present individual samples as exceeding or not exceeding the standard when in fact it does not if the actual sample hardness is used.

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Focused Feasibility StudyEagle Mine Site

* Hardness for each station was calculated by averaging the low flow (<100 cfs) measured hardness of the samples presented and used in WQS calculation; equations vary by Segment.** WQS for dissolved zinc shown for Segment 5b is the January-April WQS as this is appropriate comparison for all but fall samples (September/October).

\\DHINRICHS-990\Projects\CBS Eagle\FFS\FFS-2012\E-Results_FSS.xlsx

Figure 3 Dissolved Zinc Concentrations (mg/L) in the Eagle River Compared to Water Quality Standards by Segment

13

July 26, 2013

00.10.20.30.40.50.60.70.8

E- 3 E-10 E-12A E-15 E-22

Co

nce

ntr

atio

n (

mg

/l)

2009

1/8/09 2/19/09 3/11/09 3/25/09 4/8/09 4/20/09 9/23/09 WQS*

Segment 2 Segment 5a Segment 5b** Segment 5c

00.10.20.30.40.50.60.70.8

E- 3 E-10 E-12A E-15 E-22

Co

nce

ntr

atio

n (

mg

/l)

2010

3/6/10 3/17/10 4/2/10 4/15/10 9/24/10 WQS*

Segment 2 Segment 5a Segment 5b** Segment 5c

00.10.20.30.40.50.60.70.8

E- 3 E-10 E-12A E-15 E-22

Co

nce

ntr

atio

n (

mg

/l)

2011

3/7/11 3/21/11 4/4/11 4/18/11 5/4/11 10/11/11 WQS*

Segment 2 Segment 5a Segment 5b** Segment 5c

00.10.20.30.40.50.60.70.8

E- 3 E-10 E-12A E-15 E-22

Co

nce

ntr

atio

n (

mg

/l)

2012

3/12/12 3/26/12 4/10/12 10/18/12 WQS*

Segment 2 Segment 5a Segment 5b** Segment 5c

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* Hardness for each station was calculated by averaging the low flow (<100 cfs) measured hardness of the samples presented and used in WQS calculation; equations vary by Segment.

\\DHINRICHS-990\Projects\CBS Eagle\FFS\FFS-2012\E-Results_FSS.xlsx

Figure 4 Dissolved Cadmium Concentrations (mg/L) in the Eagle River Compared to Water Quality Standards by Segment

14

July 26, 2013

DL DL DL DL

DL0

0.0005

0.001

0.0015

0.002

0.0025

0.003

E- 3 E-10 E-12A E-15 E-22

Co

nce

ntr

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n (

mg

/l)

2009

1/8/09 2/19/09 3/11/09 3/25/09 4/8/09 4/20/09 9/23/09 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

DL DL DL DL DL0

0.0005

0.001

0.0015

0.002

0.0025

0.003

E- 3 E-10 E-12A E-15 E-22

Co

nce

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n (

mg

/l)

2010

3/6/10 3/17/10 4/2/10 4/15/10 9/24/10 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

DL DL DL DL DL0

0.0005

0.001

0.0015

0.002

0.0025

0.003

E- 3 E-10 E-12A E-15 E-22

Co

nce

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atio

n (

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/l)

2011

3/7/11 3/21/11 4/4/11 4/18/11 5/4/11 10/11/11 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

0.0055

DL DL DL DL DL0

0.0005

0.001

0.0015

0.002

0.0025

0.003

E- 3 E-10 E-12A E-15 E-22

Co

nce

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2012

3/12/12 3/26/12 4/10/12 10/18/12 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

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* Hardness for each station was calculated by averaging the low flow (<100 cfs) measured hardness of the samples presented and used in WQS calculation; equations vary by Segment.

\\DHINRICHS-990\Projects\CBS Eagle\FFS\FFS-2012\E-Results_FSS.xlsx

Figure 5 Dissolved Copper Concentrations (mg/L) in the Eagle River Compared to Water Quality Standards by Segment

15

July 26, 2013

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

E- 3 E-10 E-12A E-15 E-22

Co

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2009

1/8/09 2/19/09 3/11/09 3/25/09 4/8/09 4/20/09 9/23/09 WQS*

Segment 2 Segment 5a Segment 5b Segment 5c

DL DL DL DL DL

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

E- 3 E-10 E-12A E-15 E-22

Co

nce

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/l)

2010

3/6/10 3/17/10 4/2/10 4/15/10 9/24/10 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

DL DL DL DL DL

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

E- 3 E-10 E-12A E-15 E-22

Co

nce

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n (

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/l)

2011

3/7/11 3/21/11 4/4/11 4/18/11 5/4/11 10/11/11 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

DL DL DL DL DL

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

E- 3 E-10 E-12A E-15 E-22

Co

nce

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n (

mg

/l)

2012

3/12/12 3/26/12 4/10/12 10/18/12 WQS* DL

Segment 2 Segment 5a Segment 5b Segment 5c

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Table 2 Snow Pack and Segment 5a Spring Metal Concentrations

Year Snow Pack (% normal)

as of April 30*

March – April Range of Dissolved Metal Concentrations (mg/L)

Zinc Cadmium Copper

2005 88 0.240 – 0.550 <0.0001 – 0.0013 0.0023 – 0.0129

2006 115 0.170 – 0.900 0.000069 – 0.0027 <0.002 – 0.0190

2007 85 0.120 – 0.325 <0.0001 – 0.0217 <0.002 – 0.0095

2008 117 0.232 – 1.06 0.000054 – 0.0044 <0.002 – 0.0205

2009 104 0.292 – 0.432 0.00058 – 0.00138 0.00276 – 0.00887

2010 71 0.132 – 0.405 0.00031– 0.00065 0.0036 – 0.0074

2011 134 0.159 – 0.675 <0.0001 – 0.0019 0.0038 – 0.0114

2012 47 0.040 – 0.316 <0.0001 – 0.00036 <0.002 – 0.0034

*Source: Upper Colorado River Basin snowpack, as estimated by the Natural Resources Conservation

Service, (ftp://ftp.wcc.nrcs.usda.gov/data/snow/basin_reports/colorado/wyYYYY/basnco4.txt) where YYYY in

the url is the water year (example wy2012 is for water year 2012).

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METAL LOADING 3.0

Metal loading is commonly used as a means to identify and quantify the input from mining-related sources. In the FFS, metal loading is taken one step further and is used to estimate the load reduction needed to meet the WQS. Metal loads are calculated using the following formulas depending on the units of the measured flow.

Load (lbs/day) = flow (cfs) x metal concentration (mg/L) x 5.4 (units conversion factor)

Load (lbs/day) = flow (gpm) x metal concentration (mg/L) x 0.0116 (units conversion factor)

Likewise the maximum allowable load for a given WQS can be calculated if the flow is known.

Allowable Load (lbs/day) = flow (cfs) x WQS (mg/L) x 5.4 (units conversion factor)

Load calculations are not exact and should be regarded as estimates. Because load estimates are dependent upon a number of assumptions, they involve inherent uncertainty. Inherent in each computation of load is the calculated error associated with the measurement of metal concentration and stream flow (up to ±25 percent analytical error and ±10 percent flow error). In the analysis of loading by stream segment, it is assumed the computed load incorporates these errors and, as such, retains a compounded error of at least ±20 percent.

Sampling stations are located on the Eagle River to bracket, upstream and downstream, potential metal sources. Using discrete river segments, the difference in metal load between two stations can be calculated. The amount of load contributed by measured or “accounted” tributary inflows is known. These sources include tributary inflows from Rock Creek and Cross Creek. Past studies document that other tributaries do not contribute significant quantities of metals and thus these tributary metal loads are assumed to be zero for purposes of load accounting (Dames & Moore 1998). After subtracting the accounted load, the load difference is referred to as the “unaccounted” load. A positive unaccounted load (load increase) includes groundwater and/or diffuse surface-water inflow that are not measured. These are sometimes referred to as non-point source loads. A negative unaccounted load (load decrease) can result from losses of flow to groundwater, or from decreases in metal concentration through attenuation processes such as chemical precipitation or adsorption.

In the attempt to quantify the “unaccounted loads”, load calculations from non-stream sources are also based on estimates of the groundwater and/or diffuse surface-water inflow. These load estimates have higher variability than stream surface water loads as the inputs for concentration and flow are limited in both time and space. For example groundwater flows are estimated using pumps tests designed to determine potential pumping rates for the collection systems (errors are inherent in the pump test as well as the use of these tests to estimate inflow into a river). Groundwater loads are then based

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on grab samples from a well or wells (up to ±25 percent analytical error for the sample) and then assumed to represent all groundwater that flows within an area.

In addition to the uncertainty within each measurement and calculation, there exists a high degree of variability in water quality from year to year, month to month, and day to day. Data sets spanning different timeframes can and will result in different conclusions. Sampling heterogeneity comes from collecting more samples in one time frame or one year versus the same time frame in other years or from collecting more samples from one location versus another location within the same time frame. In an attempt to take into account the temporal variability and not have the average skewed by sampling heterogeneity, the sampling data for the season of interest (spring or fall) were averaged for each year; then the season’s average is based on the year averages which are equally weighted. These uncertainties highlight why it is important to regard the load calculations as estimates and to base the remedy design on data collected for the source of the contamination, rather than basing the design on the surface water loading estimates.

Copper and cadmium loads, while much smaller than zinc loads, are also good indicators of mineralization and mining since all three are associated with the ore minerals. Note that the alternatives evaluated later in this report to remove zinc contribution to surface water (Eagle River) will be capable of removing copper and cadmium as well. Copper and cadmium loading is generally not discussed in the text to simplify the report with the exception of the upstream load characterization (see Section 3.1). Copper and cadmium loads make up a variable but sizable portion of the metal load contributed by upstream Segment 2 to Segment 5.

To estimate the zinc loading to a specific segment, the difference between the loads at the two segment endpoint stations is calculated. A significant positive result is indicative of a zinc source located between the two endpoints. Negative loading results when the downstream station contains less load than the upstream station. Loads can be negative due to a decrease in one or both of the load components, flow or metal concentration. Losses of flow are attributed to measurement error or loss of stream flow to the ground or a diversion (such as irrigation). The Lower Reach of Segment 5a through Rex Flats and the OTP is a losing stream. Metals losses can occur through a variety of chemical processes, the primary ones being precipitation and sorption/partitioning to sediments or organics.

The loading tables in this section present data from 2005 through 2012 to cover the range of loading caused by the variability in runoff (see Table 2). The data are compared to WQS developed in 2009. Prior to 2009, the comparison to current WQS is not strictly applicable. References to “exceeding the WQS” are for illustration purposes prior to 2009 and are based on whether the measured concentration or back-calculated metal load would cause an exceedance using the current WQS equations.

Appendix C contains the tables/spreadsheets used to calculate and evaluate the loads and load reduction by station for zinc, cadmium, and copper that is needed to meet the WQS. Appendix D contains the tables and spreadsheets used to calculate the

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segment/subsegment loading calculations between stations for zinc, cadmium, and copper. Note loads presented in Appendix C are calculated using the actual measured metal concentration from the date presented; whereas, loads presented in Appendix D may be estimated on a certain day using a surrogate concentration if a particular station was not sampled on the date of the loading comparisons. Typically, concentration surrogates were used for stations E-11, E-13, E-13B and/or E-22 when these stations were not included in the CBS monitoring program. Surrogate concentrations were collected within a couple of days of the load comparison date and were always collected from the station surrogated. For example the concentration measured from E-22 on March 8, 2011 was used to represent the concentration from E-22 on March 7, 2011 in the March 7, 2011 loading comparison.

Figure 6 presents the average zinc loading for each of the segments of the Eagle River. Loading is typically a function of the thickness of the snowpack and a line is shown in Figure 6 that approximates a normal snowpack level. The presence of an above-normal snowpack in March or April is a good predictor that the spring runoff will generate above-average loading. As illustrated by the figure, most of the zinc load is added in Segment 5a with Segment 2 (upstream load) as the second largest contributor. Loading in the individual segments is discussed in the following sections.

Figure 6 Spring Zinc Loading Distribution in Eagle River Segments with Snow Pack

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3.1 SEGMENT 2

Segment 2 is upstream of Segment 5a and the watershed contains many mines and many thousands of cubic yards of mine waste that constitute a metal source to the Eagle River. Notable of these are the Horn Silver mine in Red Cliff and the Groundhog, Champion, Percy Chester, Mable, Tip Top, and Ben Butler mines upstream of the Eagle Mine. Locations of some of the mines can be found on maps by Lovering, et al. (1978) and Kirkham (2012). Table 3 presents metal loading at E-3 the downstream monitoring station.

Since 2005 upstream zinc loading during spring has averaged 29.1 lbs/day (Table 3). Table 4 shows that background loading from Segment 2 in the Spring is responsible for 13 to 28 percent of the zinc load in Segment 5a at monitoring station E-12A (18 percent on average). During March and April, background loading from Segment 2 is responsible for 16 to 41 percent2 of the cadmium load (25 percent2 on average) and 64 to 157 percent2 of the copper load (85 percent2 on average) in Segment 5a (See Appendix D).

Table 3 E-3 Metal Loading

Sample Date E-3 Load (lbs/day)(1) E-3 Load Reduction Needed to Meet WQS

(lbs/day)(2)

Cadmium Copper Zinc Cadmium Copper Zinc

1/14/2005 0.007 0.14 0.9 -- -- -- 3/17/2005 0.036 0.68 20.7 -- -- 6.68 4/3-5/05 0.110 2.28 18.2 0.03 0.52 --

4/12/2005 0.078 1.83 17.7 0.02 0.62 0.89 5/23/2005 0.923 18.46 365.4 0.02 0.80 120 9/12/2005 0.008 0.16 2.5 -- -- -- 10/18/2005 0.012 0.24 1.7 -- -- -- 1/31/2006 0.009 0.21 1.8 -- -- -- 3/23/2006 0.039 0.91 11.0 -- -- -- 4/20/2006 0.270 6.53 57.0 -- -- -- 5/22/2006 0.170 6.82 40.9 -- -- -- 9/27/2006 0.015 0.31 1.5 -- -- -- 10/23/2006 0.029 0.32 1.7 -- -- -- 1/29/2007 0.007 0.14 1.2 -- -- -- 3/20/2007 0.064 1.70 19.6 -- -- -- 4/17/2007 0.081 2.14 23.1 -- -- -- 9/25/2007 0.013 0.27 1.7 -- -- -- 10/16/2007 0.012 0.82 2.1 -- -- -- 3/25/2008 0.023 0.35 3.2 -- -- -- 4/22/2008 0.376 7.22 125.2 0.18 3.20 69.34 9/29/2008 0.009 0.18 2.9 -- -- -- 10/20/2008 0.027 0.17 0.7 -- -- -- 2/19/2009 0.027 0.13 1.1 -- -- --

2 Load percentages are based on yearly averages of the calculated daily percentage in the spring, see Appendix D.

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Table 3 E-3 Metal Loading

Sample Date E-3 Load (lbs/day)(1) E-3 Load Reduction Needed to Meet WQS

(lbs/day)(2)

Cadmium Copper Zinc Cadmium Copper Zinc

3/11/2009 0.080 0.41 4.3 0.03 -- -- 3/20/2009 0.076 1.52 15.7 0.01 0.16 -- 3/25/2009 0.056 1.19 20.9 -- -- -- 4/8/2009 0.064 1.66 32.7 -- -- 9.67

4/20/2009 0.270 2.63 38.7 0.14 -- 1.75 9/23/2009 0.056 0.26 1.9 -- -- -- 4/15/2010 0.071 3.35 25.4 -- 0.79 -- 9/24/2010 0.010 0.20 2.0 -- -- -- 3/21/2011 0.082 1.72 20.0 0.01 0.22 -- 4/4/2011 0.104 2.33 33.1 0.01 0.38 5.96

4/18/2011 0.125 2.84 53.8 -- -- 6.82 5/4/2011 2.522 4.36 37.8 2.38 1.37 --

10/11/2011 0.012 0.24 1.2 -- -- -- 3/12/2012 0.006 0.30 3.1 -- -- -- 3/26/2012 0.020 1.06 10.1 -- -- -- 4/10/2012 0.034 1.86 19.9 -- -- -- 10/11/2011 0.012 0.24 1.2 -- -- --

Eight Year Spring Average(3) 0.101 2.40 29.1 0.067(4) 1.00(4) 21.3(4)

Eight Year Spring Average without

4/22/2008 (3) 0.078 1.97 21.5 0.030(4) 0.45(4) 5.3(4)

Eight Year Maximum Spring Load 0.376 7.22 125 0.18(4) 3.20(4) 69.3(4)

Notes: Shaded rows indicate samples during March and April or “Spring”. (1) Bolded and italicized E-3 loads indicate that concentrations were greater than the WQS for the segment. (2) Bolded Load Reductions indicate the load would need to be reduced to meet Segment 5a WQS also. (3) Eight year averages are calculated by averaging the yearly average for each year 2005 – 2012. Yearly average is calculated

using all measured loads for the year to ensure that each yearly average has the same weight (see Appendix C). (4) Load Reduction yearly averages do not take into account when reduction is not needed (i.e., zeros are not included in the

average). Additionally, the Eight Year Average does not average a “zero” reduction year if no load reduction was found to be required during a year.

3.2 SEGMENT 5A

Segment 5a is the reach of the river with the largest remaining sources of zinc loading to the river (see Figure 6). Just as the monitoring stations at the beginning and end of a segment can be used to compare the loading between segments, intermediate surface water sampling stations within a segment can be used to pinpoint potential sources. Segment 5a is divided into five loading sources:

• Upstream – measured using E-3 load

• Belden – estimated by subtracting the measured E-3 load from the E-10 load

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• Lower Reach – estimated by subtracting the measured E-10 load from the E-12A load. The Lower Reach is further divided into: o Rock Creek tributary load – measured using T-10 load o Rock Creek groundwater load – estimated by subtracting the measured E-10

load from the E-11 load and subtracting out the measured load from Rock Creek (T-10) or measured directly by samples from EDS-3 well

o Rex Flats and OTP load – estimated by subtracting the measured E-11 load from the E-12A load.

Figure 7 presents loading distribution within Segment 5a for the Spring for the monitoring years 2005 through 2012.

Figure 7 Segment 5a Spring Average Loading Distribution

The Belden reach of Segment of 5a, shown in red in Figure 7, receives the most zinc load. The supporting data are listed in Appendix D. In the non-Spring low flow season (fall), the Belden reach typically receives on the order of 6.3 to 32 pounds per day (lbs/day) zinc, or about 65 percent of the Segment 5a zinc load (based on yearly averages); however, this loading does not cause an exceedance of the WQS. Each spring, snowmelt causes an increase in zinc loading, sometimes to hundreds of pounds per day during above-average snowpack years. The spring “Belden” load, represents on average 72 percent of the zinc load in Segment 5a (ranging from 53 to over 100 percent based on yearly averages).

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An additional metal load enters the Lower Reach of Segment 5a between stations E-10 and E-12A, the reach into which Rock Creek flows (Figure 2). Like the above-described Belden reach, the non-Spring metal loading does not cause an exceedance of WQS in Segment 5a.

Table 4 presents the variable zinc loading within Segment 5a as well as the upstream loading from Segment 2.

Table 4 Segment 5a Zinc Loading

Sampling

Date

Zinc Loading (lbs/day) (1) Zinc Load Reduction

Needed to Meet WQS(3)

Yearly Spring Average

Reduction Needed to

Meet WQS(4)at E-12A

Upstream(2) 5a Belden Reach 5a Lower Reach

E-3 % of E-

12A Load E-3 to E-10

% of E-12A Load

E-10 to E-12A

% of E-12A Load

E-10 E-12A

1/14/2005 0.88 4% 12.9 63% 6.6 33% 0 0

21.1

3/17/2005 20.73 40% 27.3 53% 3.7 7% 5.0 0 4/12/2005 17.74 16% 65.4 61% 24.8 23% 30 42 5/23/2005 365.4 171% -178 -83% 26.4 12% 0 0 9/12/2005 2.52 9% 19.9 75% 4.3 16% 0 0 10/18/2005 1.73 5% 26.1 75% 7.1 20% 0 0 1/31/2006 1.77 6% 28.2 92% 0.6 2% 0 0

96.4

3/23/2006 10.97 10% 92.1 84% 6.4 6% 35 40 4/20/2006 57.04 18% 167 53% 92.5 29% 0 0 5/22/2006 40.91 35% 32.3 28% 42.3 37% 0 0 9/27/2006 1.45 5% 16.4 62% 8.6 32% 0 0 10/23/2006 1.69 5% 32.1 87% 2.9 8% 0 0 1/29/2007 1.21 4% 14.2 46% 15.7 51% 0 0

8.4 3/20/2007 19.57 18% 62.2 56% 28.7 26% 0 13 4/17/2007 23.07 21% 61.1 55% 25.9 24% 0 0 9/25/2007 1.68 8% 25.2 116% -5.2 -24% 0 0 10/16/2007 2.08 11% 13.1 73% 2.9 16% 0 0 1/28/2008 1.1 (5) 8% 11.9 90% 0.2 1% 0 0

235

162 w/o 4/22/08

3/25/2008 3.24 8% 43.5 102% -4.0 -9% 0 0 4/22/2008 125.2 19% 529 81% -0.4 0% 468 455 9/29/2008 2.91 14% 9.2 45% 8.5 41% 0 0

10/20/2008 0.68 4% 10.6 65% 5.1 31% 0 0

1/8/2009 1.1 (5) 6% 10.3 60% 5.9 34% 0 0

18.2

2/19/2009 1.10 4% 17.5 68% 7.3 28% 0 0 3/11/2009 4.25 8% 37.8 67% 14.3 25% 0.1 10 3/20/2009 15.7 21% 52.6 70% 6.4 9% 4.2 5.7 3/25/2009 20.9 22% 70.8 76% 2.0 2% 21 20 4/8/2009 32.7 26% 65.7 52% 27.5 22% 18 28

4/20/2009 38.7 24% 110.7 69% 10.3 6% 28 27 9/23/2009 1.92 7% 15.3 59% 8.6 33% 0 0

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Table 4 Segment 5a Zinc Loading

Sampling

Date

Zinc Loading (lbs/day) (1) Zinc Load Reduction

Needed to Meet WQS(3)

Yearly Spring Average

Reduction Needed to

Meet WQS(4)at E-12A

Upstream(2) 5a Belden Reach 5a Lower Reach

E-3 % of E-

12A Load E-3 to E-10

% of E-12A Load

E-10 to E-12A

% of E-12A Load

E-10 E-12A

3/6/2010 NM 0% 17.7 92% 1.5 8% 0 0

18.4 3/17/2010 NM 0% 53.9 179% -23.8 -79% 9.3 0 4/2/2010 NM 0% 23.3 56% 18.2 44% 0 0

4/15/2010 25.45 14% 99.6 53% 61.6 33% 0 18 9/24/2010 1.96 9% 14.2 62% 6.7 29% 0 0 3/7/2011 NM 0% 28.9 81% 6.7 19% 0 0

81.6

3/21/2011 20 17% 91.3 77% 7.8 7% 41 44 4/4/2011 33.1 14% 91.3 38% 115.8 48% 31 127

4/18/2011 53.8 23% 121.8 52% 58.3 25% 24 67 5/4/2011 37.8 22% 110.7 63% 26.2 15% 13 30

10/11/2011 1.22 4% 15.7 57% 10.5 38% 0 0 3/12/2012 3.08 7% 30.0 70% 9.6 22% 0 0

0 3/26/2012 10.15 14% 51.1 70% 11.3 16% 0 0 4/10/2012 19.9 40% 11.5 23% 18.5 37% 0 0 10/18/12 1.3 9% 6.3 43% 6.8 47% 0 0

Eight Year Spring

Average(6) 29.1 18% 95.0 70% 22.0 15% 96.0(7) 68.4(7)

Eight Year Spring Average

without 4/22/2008(6)

21.5 18% 64.7 72% 21.8 14% 21.5(7) 58.0(7)

Notes: Sampling events included in this table are only those with results for both E-10 and E-12A. Shaded rows indicate samples during March and April or “Spring”. (1) Measured loads by station presented in Appendix D were used in this loading analysis.

Negative load represents zinc load losses within the reach identified by the bracketing monitoring stations. NM – not measured. Loads in March and April are too variable to be estimated, thus upstream loads are included with the Belden loads.

(2) “Upstream” is the load from Segment 2 measured at E-3. (3) “Zinc Load Reduction” (lbs/day) is the difference between the zinc load equivalent to the WQS and the measured zinc load for a

given sample (see Appendix C). Note that this value includes the upstream load. (4) “Yearly Spring Average Reduction at E-12A” only averages the Load Reductions for the Spring and does not take into account

when reduction is not needed (i.e., zeros are not included in the average). The average is based on all samples collected at E-12A and not only those presented on the table (see Appendix C for complete set of samples included in the average. Load at E-12A includes the upstream load. The same averaging method is used for the eight year averages at the bottom of the table.

(5) Zinc concentration not measured and was estimated based on similar time of year. (6) Eight year averages are calculated by averaging the yearly average for each year 2005 – 2012. Yearly average is calculated

using the measured loads for the year to ensure that each yearly average has the same weight. Averages are based on every sample (load) or set of samples (for loading) that exist in the year and not just the results presented in the table. See Appendix C for individual stations and Appendix D for loading between stations. Note that Average percentages will not add to 100%.

(7) The Eight Year Spring Average does not take into account days or years when reduction is not needed (i.e., zeros are not included in the averages). Thus, year 2012 is not included as all the results indicated “zero” reduction was needed.

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Summarizing the information in Table 4 in terms of loading when the WQS are exceeded at station E-12A, upstream Segment 2 (E-3) contributed 8 to 26 percent of the zinc load during the daily events when WQS were exceeded. This upstream zinc loading is not sufficient to independently generate an exceedance within Segment 5a, but can exceed the cadmium and copper WQS (see Table 3). The Belden reach contributed 38 to 84 percent of the zinc load during the daily events when WQS were exceeded at E-12A, for an eight year spring average of 68 lbs/day that would need to be removed to meet WQS. With the single highest daily measurement excluded, a zinc load reduction of 58 lbs/day, on a yearly average, would need to be removed from Segment 2 and Segment 5a to meet the WQS.

In Table 5, the loading to the Lower Reach of Segment 5a is further characterized by segregating the loading sources (see Figure 2 for sampling locations). The potential sources include:

• Rock Creek surface water load at T-10.

• Rock Creek groundwater loading contributed to the river between E-10 to E-11 minus the load measured at T-10.

• Rex Flats and OTP loading to the river between E-11 to E-12A.

Since the data presented in Table 5 were extracted from multiple sources (NewFields 2006, 2007b, 2008a, 2009, 2010, 2011, 2012, and 2013; ERM 2006 and 2009; and CDOW sampling in 2005), rarely does a single sampling event cover all the stations shown in the table. This comparison uses surrogate concentrations as discussed in Section 3.0.

Table 5 Lower Reach of Segment 5a

Sample Date(1)

Measured Load (lbs/day)(2)

Loading (lbs/day)(2)

Lower Reach

(E-10 to E-

12A)

Sub-Segments

E-10 E-11(1) E-12A

Rock Creek Rex Flats and OTP

(E-11 to E-12A)

(E-10 to E-11)

Tributary Groundwater(3)

(T-10) Rock Creek

minus T-10

5a Lower Reach minus

T-10

1/14/05 13.7 21.8 20.4 6.6 8.1 0.02 8.1 6.6 -1.5 3/17/05 48.0 70.5 51.7 3.7 22.5 7.2 15.4 -3.5 -18.9 4/12/05 83.2 125.4 108.0 24.8 42.3 14.5 27.8 10.4 -17.4 5/23/05 187.6 215.7 214.0 26.4 28.1 14.0 14.1 12.3 -1.8 6/28/05* NM 79.5* 60.5 NM -19.0 7/29/05* NM 30.0* 27.7 NM -2.3 8/25/05* NM 28.1* 24.3 NM -3.8 9/12/05 22.4 24.7 26.7 4.3 2.2 6.1 -3.8 -1.8 2.1 9/22/05* NM 16.7* 16.0 NM -0.7 10/18/05 27.9 33.3 35.0 7.1 5.5 1.5 4.0 5.6 1.6 10/25/05* NM 28.5* 26.8 NM -1.8 1/31/06 30.0 NM 30.6 0.6 5.4 -4.8 3/9/06* NM 298.8* 280.4 NM -18.4 3/16/06* NM 99.9* 145.7 NM 45.8 3/23/06 103.1 111.3** 109.5 6.4 8.2 8.7 -0.6 -2.4 -1.8 3/30/06* NM 133.8* 138.3 NM 4.5

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Table 5 Lower Reach of Segment 5a

Sample Date(1)

Measured Load (lbs/day)(2)

Loading (lbs/day)(2)

Lower Reach

(E-10 to E-

12A)

Sub-Segments

E-10 E-11(1) E-12A

Rock Creek Rex Flats and OTP

(E-11 to E-12A)

(E-10 to E-11)

Tributary Groundwater(3)

(T-10) Rock Creek

minus T-10

5a Lower Reach minus

T-10

4/6/06* NM 338.7* 384.4 NM 45.8 4/12/06* NM 288.4* 281.6 NM -6.8 4/20/06 223.9 310.9** 316.4 92.5 87.0 5.8 81.1 86.6 5.5 4/26/06* NM 305.8* 283.7 NM -22.1 5/22/06 73.2 NM 115.5 42.3 5.7 36.7 9/27/06 17.8 NM 26.4 8.6 1.4 7.2 10/23/06 33.8 NM 36.7 2.9 4.1 -1.2 1/29/07 15.4 NM 31.1 15.7 6.7 9.0 3/13/07 43.6** 57.1** 56.2 12.6 13.5 2.2 11.4 10.4 -1.0 3/20/07 81.7 59.2** 110.5 28.7 -22.5 3.6 -26.1 25.1 51.2 3/27/07 66.1 88.1** 116.2 50.1 21.9 5.8 16.2 44.3 28.2 4/3/07 53.3 69.6** 89.8 36.4 16.2 4.6 11.7 31.9 20.2 4/10/07 82.8 108.0** 118.4 35.6 25.2 0.3 24.9 35.3 10.4 4/17/07 84.1 109.0** 110.1 25.9 24.8 4.5 20.4 21.5 1.1 4/24/07 105.9 125.3** 112.0 6.1 19.4 6.0 13.4 0.1 -13.3 9/25/07 26.9 NM 21.7 -5.2 3.0 -8.2 10/16/07 15.2 NM 18.1 2.9 2.9 0.0 1/28/08 13.0 NM 13.2 0.2 1.3 -1.1 3/25/08 46.8 NM 42.8 -4.0 2.4 -6.4 4/22/08 653.8 NM 653.4 -0.4 3.4 -3.8 5/28/08* 106.5 168.0 173.4 67.0 61.6 13.0 48.6 54.0 5.4 6/24/08* 73.1 78.8 91.4 18.3 5.7 7.3 -1.6 11.0 12.6 7/29/08* 18.8 25.0 30.3 11.5 6.2 4.4 1.7 7.0 5.3 8/27/08* 14.3 22.2 23.7 9.4 7.9 1.3 6.6 8.1 1.6 9/18/08* 11.1 17.7 18.8 7.7 6.7 1.2 5.5 6.5 1.0 9/29/08 12.1 NM 20.6 8.5 0.4 8.1 10/20/08 11.3 NM 16.4 5.1 0.3 4.8 10/22/08* 10.4 16.2 18.2 7.8 5.8 1.1 4.7 6.6 2.0

1/8/09 11.4 NM 17.3 5.9 NM 2/19/09 18.6 NM 26.0 7.3 1.0 6.4 3/11/09 42.0 NM 56.3 14.3 2.3 11.9 3/20/09 68.3 NM 74.7 6.4 2.0 4.4 3/25/09 91.6 NM 93.7 2.0 3.7 -1.7 4/8/09 98.5 NM 126.0 27.5 4.4 23.1 4/20/09 149.4 NM 159.7 10.3 3.7 6.6 9/23/09 17.3 NM 25.9 8.6 1.1 7.5 3/6/10 17.7 NM 19.2 1.5 3.2 -1.7 3/17/10 53.9 NM 30.2 -23.8 5.3 -29.1 4/2/10 23.3 NM 41.5 18.2 7.0 11.3 4/15/10 125.0 NM 186.6 61.6 48.8 12.9 9/24/10 16.1 NM 22.8 6.7 0.6 6.1 3/7/11 28.9 NM 35.6 6.7 8.2 -1.5 3/21/11 111.3 NM 119.1 7.8 8.6 -0.8

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Table 5 Lower Reach of Segment 5a

Sample Date(1)

Measured Load (lbs/day)(2)

Loading (lbs/day)(2)

Lower Reach

(E-10 to E-

12A)

Sub-Segments

E-10 E-11(1) E-12A

Rock Creek Rex Flats and OTP

(E-11 to E-12A)

(E-10 to E-11)

Tributary Groundwater(3)

(T-10) Rock Creek

minus T-10

5a Lower Reach minus

T-10

4/4/11 124.4 NM 240.2 115.8 11.9 103.9 4/18/11 175.6 NM 233.9 58.3 20.7 37.6 5/4/11 148.5 NM 174.7 26.2 5.6 20.6

10/11/11 16.9 NM 27.3 10.5 5.1 5.4 3/12/12 33.1 NM 42.7 9.6 2.0 7.6 3/26/12 61.2 NM 72.5 11.3 11.1 0.2 4/10/12 31.4 NM 49.9 18.5 6.7 11.8 10/18/12 7.6 NM 14.4 6.8 2.2 4.6

Eight Year Spring

Average(4) 118.5 137.4 128.3 22.0 31.4

(3 yr avg) 7.8 24.1 (3 yr avg) 14.1 0.7

(3 yr avg)

Eight Year Spring

Average without

4/22/2008(4)

80.6 NA 120.3 21.8 NA 7.7 NA 14.0 NA

Notes: Sampling events included in this table are only those with results at least for both E-10 or E-11 and E-12A. Shaded rows indicate samples during March and April or “Spring”. (1) Sample dates with asterisks (*) are samples collected and reported by ERM (2006 and 2009) in regard to the Bolts Lake RI or

follow up monitoring; E-11 loads and associated ERM loadings with one asterisk (*) use samples collected from the Bolts Lake RI monitoring station E-11A 1,770 feet downstream of E-11, see Figure 2 and E-11 loads with two asterisks (**) are surrogates loads using ERM E-11/E-11A samples from a different day than identified.

(2) Load calculations are based on measured flow at E-12A (USGS gage 09064600) and established flow relationships to other monitoring locations (NewFields 2009). NM – not measured. Negative loading represents zinc load losses within the sub-segment identified by the bracketing monitoring stations.

(3) Rock Creek Groundwater is estimated using both loading to the actual loading segment – upper portion of the Lower Reach (E-10 to E-11) – and the entire Lower Reach (E-11 to E-12A).

(4) Eight year averages are calculated by averaging the yearly average for each year 2005 – 2012. Yearly average is calculated using the measured loads for the year to ensure that each yearly average has the same weight. Averages are based on every sample (load) or set of samples (for loading) that exist in the year and not just the results presented in the table. Note Average percentages will not add to 100%. See Appendix C for individual stations and Appendix D for loading between stations. NA – not applicable as E-11 samples were not collected in the Spring of 2008 and the averages for loads that use the E-11 station are only 3 year averages.

As illustrated in Table 5, the average spring zinc load contributed to the Lower Reach of Segment 5a is 22 lbs/day (ranging from -2.2 to 49.4 lbs/day based on yearly averages). Rock Creek groundwater is the largest source of zinc, averaging 14.1 lbs/day (based on the eight year average using entire Lower Reach, and can range up to 40.3 lbs/day based on yearly averages). Rock Creek Tributary (T-10) is the second largest zinc source with an average zinc load of 7.8 lbs/day (based on yearly averages, with individual loads ranging from 0.31 to 48.8 lbs/day, see Appendix C). The OTP and Rex Flats reach typically loses flow to the alluvium/glacial deposits and resultant zinc loads are frequently negative (based on yearly averages, the average daily load is 0.7 lbs/day, ranging from -18.2 to 13.8 lbs/day).

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The individual sources of zinc contributing to Segment 5a are further described and quantified in Section 4. The alternatives that are designed to address sources are described in Section 5.

3.3 SEGMENT 5B

Segment 5b is defined by upstream station E-12A and downstream station E-15 (Figure 2). Loading from upstream Segment 5a dominates loading in Segment 5b as shown in blue in Figure 8. In Table 6 loading to Segment 5b is divided into the following sources:

• Upstream – measured using E-12A load (Segment 5a)

• Cross Creek – measured using T-18 load (Segment 7b)

• Non Cross Creek –the difference between E-12A load and E-15 load less T-18 load.

Figure 8 Segment 5b Spring Average Loading Distribution

Summarizing Table 6, upstream loading contributed an average of 128 lbs/day of zinc or 85% (128.3/151.1) of the Spring zinc load measured at E-15 over the last eight years (or 90% using the yearly averages from Appendix D). Cross Creek contributed an average of 8.4 lbs/day zinc to the segment during Spring. The Non Cross Creek load contributed an average of 15.8 lbs/day zinc to the segment during Spring. The Non Cross Creek load component has two components:

• CTP groundwater

• WTP effluent – measured directly at the outfall or estimated using an average flow rate of 300 gpm and an average effluent zinc concentration of 0.065 mg/L

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Table 6 Segment 5b Zinc Loading

Sampling

Date

Measured Zinc

Load (1)

Zinc Loading (lbs/day)(1) Zinc Load Reduction Needed to

Meet WQS(3) at

E-15

Zinc Load Reduction

Needed to Meet WQS beyond

what is required in 5a(4)

Yearly Spring Average

Reduction Needed to

Meet WQS(5)at E-15

Upstream(2) Cross Creek

Non-Cross Creek Load

E-15 E-12A T-18 E-12A to E-15 (minus T-18)

1/14/2005 21 20 3.3 -2.4 -- --

0

3/3/2005 37 44 2.4 -9.4 -- -- 3/10/2005 44 44 2.7 -2.1 -- -- 3/17/2005 45 52 2.9 -9.9 -- -- 3/24/2005 42 39 2.5 0.7 -- -- 3/31/2005 53 54 3.2 -3.6 -- -- 4/3-5/05 60 71 4.6 -15.7 -- --

4/12/2005 107 108 11.7 -12.4 -- -- 5/23/2005 201 214 17.6 -30.9 -- -- 9/12/2005 20 27 1.4 -8.1 -- -- 10/18/2005 37 35 2.4 -0.2 -- -- 1/31/2006 30 31 2.3 -2.9 -- --

62.3

3/9/2006 301 280 8.4 12.1 91.0 Met in 5a 3/16/2006 122 146 8.3 -32.4 -- -- 3/23/2006 113 110 8.3 -4.6 -- -- 3/30/2006 147 138 10.4 -1.7 18.8 Met in 5a 4/6/2006 399 384 17.0 -2.0 86.4 Met in 5a 4/13/2006 598 634 6.6 -42.5 53.1 Met in 5a 4/20/2006 473 316 4.5 152.5 -- -- 5/22/2006 126 116 6.2 4.0 -- -- 9/27/2006 28 26 2.3 -0.6 -- -- 10/23/2006 47 37 5.6 5.0 -- -- 1/29/2007 30 31 3.0 -4.2 -- --

0

3/2/2007 18 15 2.1 0.8 -- -- 3/13/2007 59 56 6.5 -4.0 -- -- 3/20/2007 121 110 4.9 5.4 -- -- 3/27/2007 137 116 4.2 16.6 -- -- 4/3/2007 108 90 5.5 12.7 -- -- 4/10/2007 152 118 5.9 28.0 -- -- 4/17/2007 138 110 4.6 23.7 -- -- 4/24/2007 143 112 5.5 25.3 -- -- 9/25/2007 22 22 2.9 -2.3 -- -- 10/16/2007 22 18 2.2 1.6 -- -- 1/28/2008 16 13 2.0 1.0 -- --

187

(116 without 4/22/08)

3/4/2008 29 37 2.2 -9.9 -- -- 3/11/2008 26 30 2.3 -6.8 -- -- 3/18/2008 32 29 2.5 1.1 -- -- 3/25/2008 42 43 2.3 -3.3 -- -- 4/8/2008 148 134 4.0 10.0 41.8 Met in 5a 4/15/2008 386 338 7.6 40.2 187.5 Met in 5a 4/22/2008 741 653 8.3 78.8 399.8 Met in 5a 4/29/2008 507 400 18.4 88.9 119.5 Met in 5a 9/29/2008 19 21 5.2 -6.4 -- -- 10/20/2008 18 16 5.9 -4.7 -- --

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Table 6 Segment 5b Zinc Loading

Sampling

Date

Measured Zinc

Load (1)

Zinc Loading (lbs/day)(1) Zinc Load Reduction Needed to

Meet WQS(3) at

E-15

Zinc Load Reduction

Needed to Meet WQS beyond

what is required in 5a(4)

Yearly Spring Average

Reduction Needed to

Meet WQS(5)at E-15

Upstream(2) Cross Creek

Non-Cross Creek Load

E-15 E-12A T-18 E-12A to E-15 (minus T-18)

2/19/2009 29 26 NM 2.6(4) -- --

0

3/11/2009 54 56 3.8 -6.2 -- -- 3/25/2009 109 94 4.6 11.1 -- -- 4/8/2009 142 126 5.6 10.0 -- -- 4/20/2009 197 160 5.7 32.0 -- -- 9/23/2009 25 26 2.2 -3.1 -- -- 3/6/2010 19 19 0.0 -0.7 -- --

0 3/17/2010 28 30 0.0 -2.4 -- -- 4/2/2010 45 42 0.0 3.6 -- -- 4/15/2010 204 187 28.5 -10.9 -- -- 9/24/2010 26 23 7.8 -4.5 -- -- 1/17/2011 29 24 NM 4.7(6) -- --

94.3

2/16/2011 26 28 NM -1.6(6) -- -- 3/7/2011 47 36 2.5 9.3 -- -- 3/21/2011 137 119 5.1 13.2 -- -- 4/4/2011 329 240 10.7 78.2 140 12.7 4/18/2011 307 234 9.1 64.0 48.5(7) Met in 5a(7) 5/4/2011 181 175 5.0 0.8 52.5 22.4

10/11/2011 41 27 7.3 6.1 -- -- 3/26/2012 88 73 4.1 11.8 -- --

0 4/10/2012 71 50 5.2 15.8 -- -- 10/18/2012 11.5 14.4 3.4 -6.3 -- -- Eight Year

Spring Average((8)

151.2 128.3 8.4 15.8 114.6(9) Typically met; 2011-12.7(9))

Eight Year Spring Average

without 4/22/ 2008(8)

142.2 120.3 8.3 14.8 90.9(9) Typically met; 2011-12.7(9)

Notes: Sampling events included in this table are only those with results for both E-12A and E-15. Shaded rows indicate samples during March and April or “Spring”. (1) Measured loads (lbs/day) by station presented in Appendix D were used in this loading analysis.

Negative load represents zinc load losses within the reach identified by the bracketing monitoring stations. NM – not measured. Loads are too variable to be estimated

(2) Upstream” is the load from Segment 5a and above measured at E-12A. (3) “Zinc Load Reduction Needed to Meet WQS at E-15” (lbs/day) is the difference between the zinc load equivalent to the WQS and the

measured zinc load for a given sample (see Appendix C). Note that this value includes the upstream load. (4) ““Zinc Load Reduction Needed to Meet WQS beyond what is required in 5a” (lbs/day) is the difference between the zinc load

reduction required at E-15 minus the zinc load reduction required at E-12A for a given date. Negative or zero values are indicated with “Met in 5a” (see Appendix C).

(5) “Yearly Average Reduction at E-15” only averages the Load Reductions for the Spring and does not take into account when reduction is not needed (i.e., zeros are not included in the average). The average is based on all samples collected at E-15 and not only those presented on the table (see Appendix C for complete set of samples included in the average). Load at E-15 includes the upstream load. The same averaging method is used for the eight year averages at the bottom of the table.

(6) Cross Creek load was not removed as Cross Creek was not sampled on this day. (7) No load reduction would have been required on 4/18/11 to meet the WQS; the load reduction presented and the comparison to

the load required at E-12A is from the load comparisons of 4/22/11 (see Appendix C).

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Table 6 Segment 5b Zinc Loading

Notes (cont): (8) Eight year averages are calculated by averaging the yearly average for each year 2005 – 2012. Yearly average is calculated using

the measured loads for the year to ensure that each yearly average has the same weight. Averages are based on every sample (load) or set of samples (for loading) that exist in the year and not just the results presented in the table. See Appendices C for individual station and Appendix D for loading between stations. Note Average percentages will not add to 100%.

(9) The Eight Year Spring Average does not take into account days or years when reduction is not needed (i.e., zeros are not included in the averages). .

Most of the Non Cross Creek load is believed to come from the CTP because the zinc load attributable to the WTP is negligible:

300 gpm x 0.065 mg/L x 0.0116 (unit conversion) = 0.23 lbs/day

If the WQS are met in Segment 5a by zinc load reduction, Table 6 illustrates that the WQS in Segment 5b would be generally met during the Spring. For the rare example, on 4/4/2011, an additional zinc load reduction of 12.7 lbs/day would have been needed to meet WQS.

3.4 SEGMENT 5C

Segment 5c is defined by upstream station E-15 and downstream station E-22 (Figure 2). Loading from upstream Segment 5b and above, shown in dark blue in Figure 9, dominates loading in Segment 5c contributing an average of 151.2 lbs/day of zinc or 107% (151.2/141.8) of the Spring zinc load measured at E-22 over the last eight years. There are no other identified zinc sources in this segment besides upstream loading.

Figure 9 Segment 5c Spring Average Loading Distribution

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Segment 5c usually experiences a net loss in zinc load, shown in light blue in Figure 9, and the average loss over the last eight years is -24.4 lbs/day (see Table 7).

Table 7 Segment 5c Zinc Loading

Sampling

Date

Measured Zinc

Load (1)

Zinc Loading (lbs/day)(1) Zinc Load Reduction Needed to

Meet WQS(4)

at E-22

Zinc Load Reduction Needed

to Meet WQS beyond what is required in 5a(5)

Yearly Spring Average

Reduction Needed to Meet WQS(6)at E-22

Upstream(3) In Segment

Loading

E-22(2) E-15 E-15 to E-22

1/14/2005 28 21 6.4 -- --

29.9

3/3/2005 27 37 -9.7 -- -- 3/10/2005 40 44 -4.4 -- -- 3/17/2005 36 45 -8.5 -- -- 3/24/2005 35 42 -6.7 -- -- 3/31/2005 42 53 -11.6 -- -- 4/3-5/05 51 60 -8.3 -- --

4/12/2005 85 107 -22.1 29.9 Met in 5a 5/23/2005 201 201 0.0 -- -- 9/12/2005 16 20 -3.5 -- -- 10/18/2005 33 37 -3.8 -- -- 1/31/2006 25 30 -4.6 -- --

106.6

3/9/2006 306 301 4.9 202.0 34.3 3/16/2006 122 122 0.0 55.4 Met in 5a 3/23/2006 92 113 -21.4 24.3 Met in 5a 3/30/2006 120 147 -26.7 49.0 Met in 5a 4/6/2006 320 399 -79.9 135.8 Met in 5a

4/13/2006 486 598 -112.1 142.0 Met in 5a 4/20/2006 414 473 -59.2 137.9 137.9 5/22/2006 119 126 -6.6 -- -- 9/27/2006 32 28 4.1 -- -- 10/23/2006 39 47 -8.1 -- -- 1/29/2007 24 30 -6.2 -- --

8.4

3/2/2007 14 18 -3.7 -- -- 3/13/2007 46 59 -12.7 -- -- 3/20/2007 99 121 -21.2 7.5 Met in 5a 3/27/2007 117 137 -19.9 9.3 Met in 5a 4/3/2007 96 108 -11.7 -- --

4/10/2007 131 152 -20.9 -- -- 4/17/2007 121 138 -17.3 -- -- 4/24/2007 134 143 -8.9 -- -- 9/25/2007 19 22 -3.3 -- -- 10/16/2007 18 22 -3.8 -- -- 1/28/2008 13 16 -3.5 -- --

179.0

140.2 w/o 4/22/08

3/4/2008 23 29 -6.5 -- -- 3/11/2008 20 26 -5.8 -- -- 3/18/2008 26 32 -6.0 -- -- 3/25/2008 32 42 -9.3 -- -- 4/8/2008 110 148 -38.1 53.4 Met in 5a

4/15/2008 257 386 -129.0 139.2 Met in 5a 4/22/2008 646 741 -94.1 450.3 Met in 5a 4/29/2008 411 507 -95.7 188.9 5.6 9/29/2008 11 19 -7.9 -- -- 10/20/2008 15 18 -2.1 -- --

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Table 7 Segment 5c Zinc Loading

Sampling

Date

Measured Zinc

Load (1)

Zinc Loading (lbs/day)(1) Zinc Load Reduction Needed to

Meet WQS(4)

at E-22

Zinc Load Reduction Needed

to Meet WQS beyond what is required in 5a(5)

Yearly Spring Average

Reduction Needed to Meet WQS(6)at E-22

Upstream(3) In Segment

Loading

E-22(2) E-15 E-15 to E-22 2/19/2009(2) 20 29 -8.3 -- --

24.7

3/11/2009(2) 32 54 -22.4 -- -- 3/25/2009(2) 102 109 -6.9 30.0 10.4 4/8/2009(2) 103 142 -38.4 4.5 Met in 5a 4/20/2009(2) 104 197 -93.5 39.7 12.3 9/23/2009(2) 23 25 -1.8 -- -- 3/6/2010(2) 18 19 -0.1 -- --

42.0 3/17/2010(2) 29 28 1.6 -- -- 4/2/2010(2) 52 45 6.7 0.2 0.2 4/15/2010 205 204 1.1 54.0 35.7 9/24/2010 26 26 -0.1 -- --

2/16/2011(2) 34 26 8.1 -- --

110

3/7/2011(2) 35 47 -12.5 -- -- 3/21/2011(2) 123 137 -14.4 58.1 13.9 4/4/2011(2) 207 329 -121.8 86.8 Met in 5a 4/18/2011(2) 307 307 0.0 194.0 127 4/22/2011(2) 437 424 13.0 145.3 4.2 5/4/2011(2) 228 181 47.9 67.3 37.2 10/11/2011 NM 40.7 NM NM NM Spring 2012 NM See Table 6 NM NM NM NM 10/18/2012 11.1 11.5 -0.4 -- -- Eight Year

Spring Average(8)

141.8 151.2 -24.4 71.5(8) 31.8(8)

Eight Year Spring

Average without

4/22/2008(8)

136.3 142.2 -23.5 66.0(9) 31.0(8)

Notes: Sampling events included in this table are only those with results for both E-15 and E-22. Shaded rows indicate samples during March and April or “Spring”. (1) Measured loads (lbs/day) by station presented in Appendix D were used in this loading analysis.

Negative load represents zinc load losses within the reach identified by the bracketing monitoring stations. NM – not measured. Loads are too variable to be estimated

(2) Loads for E-22 in this table may be based on a measured concentration from the day before or after the day shown in the table. The surrogate concentration was used with the flow for the day on the table to calculate the estimated load at E-22. The load reductions are based on the actual loads for the E-22 dates (see Appendix C)

(3) Upstream” is the load from Segment 5b and above measured at E-15. (4) “Zinc Load Reduction Needed to Meet WQS at E-22” (lbs/day) is the difference between the zinc load equivalent to the WQS and

the measured zinc load for a given sample (see Appendix C). Note that this value includes the upstream load. (5) ““Zinc Load Reduction Needed to Meet WQS beyond what is required in 5a” (lbs/day) is the difference between the zinc load

reduction required at E-22 minus the zinc load reduction required at E-12A for a given date. Negative or zero values are indicated with “Met in 5a” (see Appendix C).

(6) “Yearly Average Reduction at E-22” only averages the Load Reductions for the Spring and does not take into account when reduction is not needed (i.e., zeros are not included in the average). The average is based on all samples collected at E-22 and not only those presented on the table (see Appendix C for complete set of samples included in the average). Load at E-22 includes the upstream load. The same averaging method is used for the eight year averages at the bottom of the table.

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Table 7 Segment 5c Zinc Loading

Notes (cont): (7) Eight year averages are calculated by averaging the yearly average for each year 2005 – 2012. Yearly average is calculated using

the measured loads for the year to ensure that each yearly average has the same weight. Averages are based on every sample (load) or set of samples (for loading) that exist in the year and not just the results presented in the table. See Appendices C for individual station and Appendix D for loading between stations. Note Average percentages will not add to 100%.

(8) The Eight Year Spring Average does not take into account days or years when reduction is not needed (i.e., zeros are not included in the averages). .

If the WQS are met in Segment 5a by zinc load reduction, Table 7 illustrates that the WQS in Segment 5c would be generally met during the spring with the exception of several dates in five of the last seven years (no samples for the Spring of 2012), where an additional zinc load reduction of an average of 31.8 lbs/day over the seven year period (2005-2011) would have been needed to meet WQS within Segment 5a as measured at E-22 (additional reductions range up to 138 lbs/day measured 4/22-26/2006). It is noted that Table 7 and Appendix C are heavily populated with surrogates that yield loads calculated from different days. The upper end of the load reduction range may be inflated by the surrogate reduction calculations.

3.5 LOADING SUMMARY

The eight year Spring zinc load estimates for Segment 5 are summarized in Table 8. Note that the segment totals are not sums of the tabulated numbers; they are based on in-stream data.

Table 8 Spring Zinc Load Summary, Segment 5

Reach or Segment

Source Surface Water

Monitoring Stations

Average Spring Load lbs/day

Reference

Segment 5a

Belden Reach Upstream E-3 29.1 Table 3

Belden groundwater E-3 to E-10 95.0 Table 4

Lower Reach Rock Creek groundwater --- 14.1 Table 5

Rock Creek surface water T-10 7.8 Table 5

OTP/Rex groundwater E-11 to E-12A 0.7 Table 5

Segment Total E-12A 128.3 Table 5

Segment 5b Upstream E-12A 128.3 Table 6

Cross Creek T-18 8.4 Table 6

Non-Cross Creek --- 15.8 Table 6

Segment Total E-15 151.2 Table 6

Segment 5c Upstream E-15 151.2 Table 7

Segment Total E-22 141.8 Table 7

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METAL SOURCE CHARACTERIZATION WITHIN SEGMENT 5A 4.0

In the previous section, zinc loading to the river is used to characterize source contributions and to identify the load reductions needed to meet the WQS. In this section, the sources in Segment 5a are characterized using the wealth of information from the many studies completed over the past 25 years. For some of the sources there is enough information to quantify the zinc load contribution directly, independent of the river loading. A summary table at the end of the section lists and compares zinc load estimates that are available for use in gauging the effect of the remedial alternatives.

4.1 UPSTREAM METAL LOAD

As described in Section 3.1, a measurable consistent metal load is sourced into the segment from upstream (Segment 2). On average 18 percent of the zinc, 25 percent of the cadmium, and 85 percent of the copper load of Segment 5a is background (see Section 3.1 and Appendix D). This load will be present regardless of any actions taken to reduce metal loading from sources within the Eagle Mine Site. These loads are also been known to exceed the cadmium and copper WQS of the Segment 5a, and though the zinc WQS for Segment 5a is not exceeded by the E-3 concentration, Segment 2 load does at times exceed the Segment 5a load (as measured by E-3 and E-12A, respectively); see Appendix D for examples in all seasons of the Upstream load representing over 100 percent of the E-12A load.

4.2 BELDEN

In 2006, CBS and NewFields proposed to meet the anticipated WQS in Segment 5a by extracting and treating groundwater in Belden, the site of the underground mill and location of the railroad siding on the river below Gilman. Investigations in Belden were initiated on a voluntary basis and continue to the present. Much of the information used in the description of metal sources in Belden has been documented in annual reports and performance reports (NewFields 2007a, 2007c, 2007d, and 2008b) that list data collected from Belden and Rock Creek wells and as-built information for the Copper Tipple Trench, a groundwater collection trench constructed in 2007.

4.2.1 Groundwater Quality

Groundwater samples have been regularly collected from the Belden wells since 2009. Figure 10 presents the location of the Belden groundwater monitoring wells, and Table 9 presents the Belden groundwater sample results.

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Table 9 Groundwater Quality in the Belden Area

Location Sample Date Total Cadmium

(mg/L) Total Copper

(mg/L) Total Zinc

(mg/L)

5/9/08 0.975 11.3 245

BTS-1 Copper Tipple Trench

3/11/09 0.635 9.77 116 3/25/09 0.559 6.75 107 4/8/09 0.519 10.2 196 4/20/09 0.55 6.2 118 4/15/10 0.671 10.2 173

4/4/12** 1.35 29.1 381

BW-3R

3/11/09 1.74 11.5 220 3/25/09 1.53 18.7 212 4/8/09* 1.7 17.5 213 4/20/09* 2.13 12.9 193

BW-5 4/22/09 1.24 1.97 304 BW-6 4/22/09 2.83 0.137 787 BW-7 4/22/09 1.84 14.5 422

BW-9R

1/8/09 0.663 0.0929 233 2/19/09 0.555 0.109 249 3/11/09 0.68 0.102 214 3/25/09 0.597 0.113 225 4/8/09* 0.0364 0.0229 41 4/20/09* 0.11 0.0208 64 4/15/10 0.488 0.0771 170

4/4/12** 0.291 0.064 137

BW-10

1/8/09 4.96 5.88 847 2/19/09 4.3 5.09 979 3/11/09 4.82 21.9 727 3/25/09 3.99 17.6 763 4/2/09* 2.27 17.3 492 4/8/09 3.77 24.8 924 4/20/09 2.67 13.9 517 4/15/10* 4.6 24.8 726

4/4/12** 37.8 16.1 714 Notes: * Sample collected after the well was subjected to pump tests on 4/2/2009 or 4/15/2010. ** Sample collected after the well was subjected to pump test on 4/4/2012.

Eagle River WQS are not exceeded in late summer, fall, or winter after the river recedes following the snowmelt; therefore, it was postulated that groundwater flow must increase at Belden each spring. Several years of water level measurements in seven Belden monitoring wells indicate that the water table in the vicinity of the Copper Tipple Trench and the railroad in Belden rises each spring in response to recharge from snowmelt and/or seepage from the Mill Level. Studies were undertaken in the spring of 2009 and 2010 to understand the timing and location of the spring groundwater flow in Belden, as well as to assess remedial options. Study results, discussed in the section, indicate that a significant increase in the local water table elevation is correlated with an increase in the zinc concentration and specific conductivity in the Belden reach of the river.

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Figure 10 Belden Area Groundwater Monitoring Locations

Pump tests were conducted at BW-10, BW-9R, and BW-3R on April 2, 2009. The transmissivity of the fill beneath the railroad was determined to be 0.8 and 1.1 ft/day for BW-3R and BW-9R, respectively. The pump test data are presented in the 2009 Annual Report (NewFields 2010).

A 24-hour pump test was conducted at BW-10, BW-9R, and Copper Tipple Trench (BTS-1) on April 15, 2010. Using three submersible pumps, sustainable pumping rates of between 8 and 16 gpm were achieved. The pumped Belden well water was sampled and the results (Table 9) were used to estimate the zinc load captured during the pump test:

BW-10 10 gpm x 726 mg/L x 0.0116 (unit conversion) = 87.5 lbs/day

BW-9R 8 gpm x 170 mg/L x 0.0116 (unit conversion) = 16.4 lbs/day

BTS-1 16 gpm x 173 mg/L x 0.0116 (unit conversion) = 33.3 lbs/day

Total 34 gpm 137 lbs/day

In the drought year of 2012 the spring inflow of groundwater in Belden occurred on March 3, again causing a groundwater level rise in the collection trench of 7 feet. On April 4, three Belden wells were pumped continuously using 10 gpm submersible pumps. Owing to very low water levels, pumping rates of 10 gpm were not sustainable. After 4 hours of pumping it

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was estimated that combined yield from two of the three wells represented about 38 lbs/day recovered zinc, substantially less than the April 2010 pump test yielded.

BW-10 3.9 gpm x 714 mg/L x 0.0116 (unit conversion) = 33.5 lbs/day

BW-9R 3.1 gpm x 137 mg/L x 0.0116 (unit conversion) = 5.1 lbs/day

Total 7 gpm 38 lbs/day

As a check on the pump test estimates, the flow per foot of buried pipe at the East groundwater extraction trench at the CTP has been estimated to be approximately 0.03 gpm/ft based on an average yield of 11 gpm from 300 feet of saturated 6-in diameter drain pipe. If the April 2010 flow-weighted zinc concentration of 334 mg/L is used to represent the average zinc content of the output, a 700-foot long perforated pipe in Belden could yield:

700 ft x 0.03 gpm/ft = 21 gpm x 334 mg/L x 0.0116 (unit conversion) = 84.5 lbs/day

For this report, 80 lbs/day is conservatively used to represent the high end of the zinc capture rate during the 2-month operating period in Belden. The high end of the range, 137 lbs/day estimated using the 2010 pump test, was reduced because a flow rate of 34 gpm likely cannot be maintained over the spring due to lack of recharge.

Water level transducers were placed into BW-10, BW-9R, and the Copper Tipple Trench (BTS-1) from January 8 through May 8, 2009 and from February 16 through May 9, 2010. As shown in Figure 11, the increased groundwater flow occurred on or about February 23, 2009 and on or about March 1, 2010. This increase flow causes a 7-foot increase in the water level in the trench and smaller increases in the other nearby wells. The trench and water levels show a second pulse at the beginning week of April in both years.

Figure 11 Belden Area Groundwater Elevations for the Spring 2009 and Spring 2010

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With dissolved zinc concentrations within the Eagle River superimposed upon the water level hydrograph (Figure 12), the timing of the zinc concentration increase in the river is observed to coincide with the increased groundwater flow through the Copper Tipple Trench and nearby wells.

Figure 12 Belden Area Water Levels Versus Dissolved Zinc Concentrations in the Eagle

River, Spring 2009 and Spring 2010

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4.2.2 Historic Tunnel

An unmapped historic tunnel (see Figure 10) was discovered while excavating the Copper Tipple Trench. This timber-supported tunnel crosses the trench at a right angle (Figure 13). From its exposure in the Copper Tipple Trench, the tunnel heading of North 40° East takes it under the Copper Loading Tunnel into the mountain where it intersects a narrow worked-out vein that is visible underground in the Mill Level. The portal has not been located but if not destroyed probably is buried under railroad ballast. The tunnel is of more than historic interest because it probably acts as a drain since it intersects the Mill Level and the Copper Tipple Trench. The tunnel and trench fill with water each spring, rising to about 8370 ft or 4 ft above the tunnel floor. The historic tunnel extends under the railroad in the direction of the river and probably acts like a point-source for metals (see Figure 13).

Figure 13 Cross Section at Historic Tunnel and Mill Level

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4.2.3 Mill Level

In the spring, melting ice and snow collects in the mine workings that house the underground mill between the Newhouse level (8483 ft MSL) and the Copper Tipple Loading Tunnel (8397 ft MSL) or about 40 feet topographically above the Eagle River. When the mine and mill were operating, water that accumulated in the Mill Level was pumped out for treatment. At present, the so-called Mill Level water picks up elevated metal concentrations due to contact with ore and concentrates in the underground mill. Once the Mill Level water reaches its maximum depth of 10 inches or so, it leaks out through old pipelines, fractures in the granite, and two tunnels that serviced the mill, the Loading Tipple and the Service Incline (Figure 10). Mill Level seepage probably recharges the shallow groundwater in the Copper Tipple Trench area (see Section 4.2.2). Analytical results for grab samples of the impounded water are presented in Table 10.

Table 10 Water Quality in the Mill Level

Sample Date Metal Concentrations, mg/L

Cadmium Copper Zinc

MILL-1 5/10/10 0.671 (D) 1.79 (D) 196 (D)

MILL-2 7/8/10 0.928 (D) 0.665 (D) 151 (D)

MILL-1 3/11/12 0.532 (T) 0.671 (T) 585 (T)

MILL-2 3/12/12 0.551 (T) 0.987 (T) 562 (T)

Notes: (D) dissolved – filter using a 0.45 um in-line filter (T) total – unfiltered

On March 11 and 12, 2012, a portable electric sump pump was used to dewater the Mill Level pool 9 inches down to the floor level. Temporary electricity was supplied via a 400-foot-long power line energized by generator. Over a 24-hour-period, 24,000 gallons of mine water were pumped out of the Mill Level to an existing 3-inch diameter pipe in the Service Incline that leads to the WTP via the main pipeline in Belden. The 24,000 gallons represents a one-time zinc load of 115 lbs.

24,000 gallons x 574 mg/L x 1L/0.264 gallon x1 lb/0.4536 mg = 115 lbs

Transducers permanently installed in the Mill Level record the air temperature, water temperature, and the rate of water level rise/fall during the year. Underground surveys are conducted to determine how fast and where the Mill Level pool is being recharged. After dewatering, the pool apparently fills slowly with seepage from rock fractures in the tunnels. No specific zones of high recharge have been identified. Freezing temperatures are present in March and April and melting of ice in fractures occurs throughout the summer. The shallow pool in the Mill Level rose 0.5 feet in 60 days between March 12 and May 11, 2012. The measured increase in pool level represents approximately 16,000 gallons for an estimated recharge rate of 266 gpd.

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4.2.4 Conductivity Surveys

Specific conductance surveys were conducted along the north bank of the Eagle River on April 22, 2009 and April 14, 2010. Thick ice shelves along the bank prevent surveys from being conducted in late March and early April when the groundwater surge may be detectable. As shown in Figure 14 and Figure 15, elevated conductance was measured along the river bank in Belden but was much more obvious in 2009 than 2010.

4.2.5 Railroad Ballast

Sample results from the wells in Belden that are near the railroad suggest that the railroad ballast and associated fill may be a source of leachable metals. Metals would be leached from the ballast, waste rock, and bank materials in Belden by rainfall, snowmelt, and groundwater. At CDPHE’s request, a test pit was excavated in the railroad ballast in 2009 on the river side of the railroad 70 feet upstream of well BW-7 (BW-7 north, see Figure 14 for well location). The pit was excavated to a total depth of 7.5 feet in waste rock, silt, coal clinker, and other materials used as ballast and fill. In July and August, 2012, several more test pits were excavated in Belden; 1) near BW-7 along the exposed track, and 2) along the north side of the buried railroad spur from near well BW-8 upstream along the railroad that parallels the Dryer building and the concentrate bins (see Figure 10). The BW-8 west and north pits were excavated to a depth of 7 feet in waste rock, brick, timbers, and various fill materials. XRF assay results for selected metals are presented in Table 11.

Table 11 Railroad Ballast Sample Results

Sample XRF assay

number Arsenic (mg/kg)

Cadmium (mg/kg)

Lead (mg/kg) Zinc (mg/kg)

BW-7 east, 3.5 – 6.0 ft NA NA <66 1,279 4,249 BW-7 east, 6.0 – 7.5 ft NA NA <84 6,409 7,398 BW-7 east, 2.3 – 5.0 ft NA NA <93 5,140 4,551 BW-7 north, 2.5-3.5 ft 33 160 ND 665 2,699 BW-7 north, 3.5-7 ft 32 353 ND 3,257 5,559

BW-8 west - black silt layer 17 <1.1 1440 32,000 293,000 BW-8 west – grab #1 24 2,098 80 7,177 15,700 BW-8 west – grab #2 23, 25 15,100 -

22,300 114-162 2,132-3,803 8,527-12,300

BW-8 north, at 7 ft 16 1,576 <88 10,800 10,600 BW-8 north at concrete

pad 4.5 ft 18 1,904 <53 9,454 5,748

BW-8 south, at rails 20 in deep

28, 29 403-527 105-157 5,662-6,676 18,100-21,900

Concentrate Bldg, 0 – 6 ft 30, 31 ND ND 1,307-2,475 2,044-3,427 Dryer Bldg, at ties 2 ft

deep 26, 27 911-1,446 ND 29,400-31,200 3,807-4,526

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Figure 14 Eagle River Conductance Survey, Belden Area, Spring 2009

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Figure 15 Eagle River Conductance Survey, Belden Area, Spring 2010

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The results for the BW-7 north and east test pits indicate that the ballast contains metals at concentrations typical for waste rock. The highest metal levels in some of the BW-8 and Dryer Building test pit samples are in the percent range and may be indicative of ore grade material or mill concentrates. It is therefore concluded that the ballast presents a leachable source of metals to surface water and groundwater.

As an historical note, the Iron Mask mill was located on or near the location of the Dryer building (Figure 10) based on old photographs. Some of the very high metal assays could be associated with concentrates from this older mill. Both the Iron Mask mine and mill (1900?) and the entry of the railroad (1894) predate the Eagle mine.

Some of the older rails are buried 2 feet below the current track level. When encountered the old ties and rails were not excavated which limited the depth of the test pit. No test pit work has been completed in the vicinity of wells BW-3R, BW-9R, and BW-10 due to lack of room between the rails and the Loading Dock and interference with the pipeline. As such, the ballast investigation was limited and the depth and areal extent of the waste rock and other fill materials below and around the railroad is generally unknown. The volume of material used for railroad ballast was not estimated.

4.3 WASTE ROCK

A total of 16 waste rock piles were identified and reported in the Data Evaluation Report Belden Area (DER, Dames & Moore 1997a). The locations of most of the piles are presented on Figure 16. Waste rock pile information is presented in Table 12 and Table 13.

Table 12 Waste Rock Pile Information

Waste Rock Pile

Nearest Adit or Shaft

Drainage Estimated Volume (1)

(cubic yards)

Average Slope (2)

(degrees) Acid-Base Account

WP-1 Belden Fan Ben Butler 13,800 37 Little or no acid potential

WP-2 St. Joe Ben Butler 6,370 36 Little or no acid potential

WP-3 Unknown Tramway 820 29 Little or no acid potential

WP-4 Mask Tramway 6,570 34 Little or no acid potential

WP-5 Mask Tramway 7,990 37 Little or no acid potential

WP-6 Polar Accidental

None 1,180 32 Some acid potential but volume small

WP-7 Chief Incline Rock Creek 5,280 37 Little or no acid potential

WP-8 Wilkesbarre Shaft

Rock Creek 200,000(1) 34 Acid potential

WP-9/ WP-10

Ben Butler Tip Top

Ben Butler 16,500(4) 38 Acid potential

WP-11 Chief Incline Rock Creek 37,220 49 Little or no acid potential

WP-12 Uncle Sam Rock Creek Not Calculated(3)

10 Some acid potential but volume small

WP-13 Rocky Pt. Tramway 790 48 Acid potential

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Table 12 Waste Rock Pile Information

Waste Rock Pile

Nearest Adit or Shaft

Drainage Estimated Volume (1)

(cubic yards)

Average Slope (2)

(degrees) Acid-Base Account

WP-14 Newhouse Tramway 175(5) 31 Acid potential

Adit 7 Adit 7 Rock Creek 486 43 Some acid potential but volume small

Crossbeam Crossbeam None 3,470 36 Little or no acid potential

Notes: Source: DER (Dames & Moore 1997a). (1) The volume estimates were calculated using the average depth of the excavations advanced at each sampling location and

therefore are low. Due to location in steep terrain, none of the piles have been drilled to test the thickness except WP-8. The volume for WP-8 was taken from the Remedial Investigation Report (ERM 2006). The volume of WP-9/WP-10 was visually estimated in 2011.

(2) The average slope of the waste rock piles was determined using inclinometer measurements taken at the sample locations. (3) WP-12 was used as fill and does not exist as a surface feature. (4) The WP-9/WP-10 volume was re-estimated in 2012 after the crib wall was constructed. (5) The volume of WP-14 was reduced by CBS during the 2006 and 2009 waste rock/concentrate removals near the Copper

Tipple Loading building in Belden. Volume shown is 30 percent of the original estimate.

Table 13 Waste Rock Pile Mean Metal Concentrations

Waste Rock Pile Mean Metal Concentrations (mg/kg)(1)

Arsenic Cadmium Lead Zinc

WP-1 781 91 17,225 20,475

WP-2 632 52 16,847 10,023

WP-3 2,060 40 39,050 8,665

WP-4 752 162 9,605 38,200

WP-5 1,346 225 18,340 57,040

WP-6 950 2.8 1,878 94,946

WP-7 850 66 10,910 10,240

WP-8 710 35 6,388 6,558

WP-9/WP-10 141 20 2,556 3,644

WP-11 146 25 7,962 5,547

WP-12 123 10 12,020 1,900

WP-13 585 0.87 1,643 655

WP-14 802 12 3,901 3,607

Adit 7 116 0.76 5,230 673

Crossbeam 53 8.8 790 1,490

Notes: Source: DER (Dames & Moore 1997a); concentrations are averages of several samples collected from each pile. (1) One-half of the detection limit was used to quantify nondetects when calculating mean concentrations.

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While metal concentrations are elevated in some piles, most of the piles possessed little or no potential to generate acid, thus they were classified as minor sources of leachable metals. In summary, the potential impact to the Eagle River from many of the piles tested was described in the DER as low because of the following:

• Minimum or no potential to generate acid (WP-1, WP-2, WP-3, WP-4, WP-5, WP-7, WP-11, and Crossbeam)

• Small size of the pile and large grain size of the material in the pile (WP-6, WP-12, Adit 7)

• Lack of an identifiable pathway to the Eagle River (WP-6, WP-12).

The waste rock piles found to be the most likely to generate acid and impact the Eagle River are WP-8, WP-9/WP-10 (sampled jointly as one pile), WP-13, and WP-14. These piles are discussed in more detail in the following paragraphs and photographs are presented in Appendix E.

WP-8: WP-8 is located near the Wilkesbarre shaft along the paved entrance road into Gilman. This large 3.4 acre pile contains an estimated 200,000 cubic yards (cy) based on measurements made during a drilling program conducted by ERM (2006). The pile consists of an upper bench and a lower bench accessible by wheeled or tracked vehicles. Test results indicate that the upper bench material has minimum or no net potential to generate acid, but three of the five samples collected from the lower bench indicate a net potential to generate acid. An unknown portion of the pile rests on an old landslide deposit that extends from the toe of the pile to Rock Creek. Seeps within the landslide are recharged by rainfall and snow melt. WP-8 is terraced and has a westerly exposure and the winter snowpack is much thicker on this pile compared to the other waste rock piles on steep south-facing slopes.

A surface water diversion system was constructed in 2001 that conveys captured runoff via pipeline to the Fancy Shaft, where it recharges the mine pool. The system was expanded in 2006 with the construction of a second, lower collection basin near Adit 7. Improvements to existing runon diversions above the pile were made in 2011 to re-direct clean water to Rock Creek. The upper and lower facilities are shown on Figure 17. Both facilities are subject to plugging with sediment. Occasionally, sediment is excavated from the Fancy shaft, however, the lower collection facility requires frequent shoveling by hand to remove sediment during the spring. If it plugs, the water enters the groundwater/surface water system in Rock Creek.

Additional detailed information characterizing the metals in waste rock, surface soils, surface water and groundwater associated with WP-8 is available in a site investigation of North Gilman, part of Operable Unit 2 of the Eagle Mine Superfund Site (ERM 2007b).

WP-9/WP-10: WP-9 and WP-10 are coalesced waste piles remaining from the Ben Butler and Tip Top mines upstream of the Eagle Mine. These early gold mines date to

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the late 1800s. The piles are accessible by vehicle from the railroad grade in Belden. The volume of 16,500 cy listed in Table 12 is a rough estimate that has not been confirmed by drilling. The two piles were combined for sampling purposes with four samples collected from the combined piles. Results indicate that the two downhill samples have little or no net potential to generate acid, but the two uphill samples have net acid generation potential. Due to the deteriorating condition of the old cribbing and the potential for release of waste rock into the river, EPA’s Removal Program constructed pre-cast concrete block retaining walls to intercept the eroding waste rock from several piles along the river. WP-9 and WP-10 are contained behind the concrete retaining wall.

Well BW-2 is located at track level at the base of the Ben Butler mine. It lacked sufficient water to sample but based on specific conductivity results alone, the groundwater is less mineralized than background well BW-1 but more mineralized than river water (DER 1997a).

WP-13: WP-13 consists of two conical piles located outside the Rocky Point mine portal at the base of the cliff below Gilman. The Rocky Point mine was one of the early day gold producers on Battle Mountain in 1885 (Knight and Hammock 1965). The fact that it is a gold mine would explain why the cadmium, lead, and zinc levels are among the lowest of any waste rock pile. The piles are accessible by foot from Gilman or Belden. The volume of 790 cy listed in Table 12 is considered to be an underestimate. Three samples were collected from WP-13 and all results indicate a net potential to generate acid. Waste rock from this pile has not been disturbed due to very difficult access in steep terrain north of the old tramway. The twin piles are very steep, south-facing, and typically free of snow during the winter and runoff has never been visually observed. Based on topography only, some runoff could enter the Tramway Drainage.

WP-14: WP-14 consists of crushed ore, concentrates, waste rock, and roaster material from the old aerial tram that was used to transport waste across the Eagle River. The pile is located adjacent to and uphill from the Copper Tipple Loading building in Belden. The volume of WP-14 was reduced by CBS during the 2006 and 2009 waste rock/concentrate removals and it is assumed that 175 cy remain at the original WP-14 location. Further efforts to remove WP-14 were curtailed in 2009 due to the risk of destabilizing the Copper Tipple Loading building and the cribbing below the Newhouse portal. All seven samples collected from this pile yielded a net potential to generate acid. Very little snow collects on this south-facing pile. With the steep topography, runoff from WP-14 reports to the Tramway Drainage or the Loading Dock below the Copper Tipple Loading building.

The perimeter of WP-14 is not defined because there are no significant visual or chemical differences between it and adjacent mill wastes or concentrates associated with former surface mills and former mines reported to be in Belden prior to the formation of the Eagle mine. XRF reconnaissance in July 2012 indicated that surface zinc concentrations range

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as high as 13,000 ppm in the vicinity of WP-14. No estimate has been made of the volume of material that realistically could be excavated from the WP-14 slope because of the difficulty of determining depth; however, it is expected to be well over 1000 cy.

4.3.1 The DER Summary of Waste Rock Zinc Loading to the River

The DER integrated data from the waste rock pile testing program and a surface water sampling program. The surface water sampling program consisted of detailed sampling of summer and fall rainfall-runoff events and spring snowmelt events from 1995 to 1997. This discussion is focused on snowmelt runoff that was measured in nine events in 1996 and 1997. Snowmelt zinc loading in the Belden reach between E-3 and E-5 was primarily contributed from upstream sources (average 19.9%), T-TR Tramway Tributary (average 3.7%), T-6 Roaster Drainage (2.8%) and diffuse runoff/ groundwater (average 64.8%). Tramway Tributary receives runoff from WP-3, WP-4, WP-13, and WP-14 (see Figure 16). More recently (2005 to present) the data indicate that upstream sources (E-3) contributed an average of 28% during the spring snowmelt season and diffuse runoff/groundwater averages 72% (Table 12). The recent data includes all tributary loading in the diffuse runoff/groundwater quantity and the E-5 station was replaced by E-10 further downstream.

In 1996 - 1997, snowmelt zinc loading to the Rock Creek reach of the river (between stations E-5 and E-11) below Belden was dominated by upstream loading from the Belden reach (average 50.5%, station E-5R Table 3-2-17). The largest tributary zinc load contributions were from Rock Creek, measured at SR-4 and T-10R. These two stations combined for an average of 38.2% of the zinc load as they, at that time, received drainage from WP-7, WP-8, and WP-11 (see Section 4.4, Rock Creek). Since 1997, the installation of two surface water collection systems on WP-8 (see Figure 17) and establishing control of the mine pool has reduced the surface water zinc loading at T-10 and altered the percent contributions. Rock Creek contributes an average of 7.8 lbs/day during the spring (Table 5) or about 8.8 percent of the average load in the reach (Appendix D). Upstream loading from the Belden reach constitutes 70 percent of the zinc loading, on average (Table 4).

The DER concluded that zinc loads, contributed periodically via rainfall-runoff from the waste rock piles on the canyon slopes, constituted less than 2 percent of the annual zinc load transported in the river. Snowmelt runoff contributed more zinc to the river than rainfall-runoff, and contributed zinc during the spring when metal concentrations in the Eagle River were highest. However, most of the snowmelt zinc loading (62 to 88 percent) could not be accounted for in the flowing tributaries. Based on comparisons to the recent data, it is concluded that runoff from the waste rock piles is not a driver of zinc loading during the snowmelt season when WQS are periodically exceeded.

Using rainfall statistics from Vail, Colorado the DER noted that only about 15 runoff events would occur at the Site in any year and that a typical event would generate 5.5 lbs/hr of

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zinc for 2 hours at E-11. Note that these events are in lbs/hr (pounds/hour) not lbs/day (pounds/day). The short-term event loading does not explain the longer-term zinc loading observed during March and April. The DER noted that when the tributaries draining the waste rock piles are dry, the spring zinc loading to the river continued unabated. The rainfall and frequency of events is viewed as additional evidence that runoff from the waste rock piles cannot be the driver of zinc loading during the snowmelt season.

4.3.2 Evaluation of Waste Rock as a Source, Leachate Method

As an alternative to measuring the zinc in the river that may have been sourced in waste rock piles in and around Gilman, in this section, “leachate” is used as a means to estimate the zinc load that could be derived from the waste rock piles.

4.3.2.1 Leachant Volume Estimates

For an estimate of zinc load transported by leachate from the piles, the starting volume of leachant is required. The results of snow surveys conducted at the CTP during early March for the years 1992 through 1997 are presented in the DER. These past water-equivalent measurements at the CTP are used to develop a conservative estimate of the volume of leachant that would infiltrate the waste rock piles in Belden. The snow cover on the CTP is estimated to contain an average of 7 inches of water and this amount has been used as the starting volume. Much of the water in the snowpack is lost to the atmosphere through evaporation or runs off on the steep, rocky slopes. The infiltration rate for glacial till, 4.38 inches/year (Table 5-2, Dames & Moore 1997b) was used as an estimate of deep percolation. Leachant volume estimates were derived for selected waste rock piles in Table 14 using the equation:

Surface area (ft2) x infiltration (ft) x 7.48 gallons/ft3 = gallons

Table 14 Waste Rock Pile Leachant Volume Estimates

Waste Rock Piles Estimate volume

@ 4.38 inches/year of infiltration

Name sq ft cu ft of leachant Gallons of leachant

WP-13 & WP-14 20,000 7,300 54,604

WP-9/WP-10 375 ft x 60 ft = 22,500 8,212 61,429

WP-8 400 ft x 350 ft = 140,000 51,000 382, 230

4.3.2.2 Zinc Source Load Estimates

Waste rock samples from the Belden area were tested for the Eagle River Watershed Council (MFG 2004). In 25 samples tested using deionized water, the zinc concentration in the leachate ranged from 0.11 to 2.18 mg/L. The highest concentration of 2.18 mg/L is used as the point estimate for Belden area piles WP-13, WP-14 and WP-9/WP-10. If it assumed that 116,033 gallons of leachant (Table 14) leaches the piles and seeps to the

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river at 10 gpm, the original volume will be exhausted in 8 days and the zinc load entering the river would be 0.26 lbs/day (see Table 15).

116,033 gallons/10 gpm (gals/min) = 11,603 min or 8 days

10 gpmx 2.18 mg/L x 0.0116 (unit conversion) = 0.26 lbs/day

ERM collected synthetic precipitation leaching procedure (SPLP) samples from three soil borings in WP-8 (ERM 2007). In nine samples tested, the SPLP zinc concentration in the leachate ranged from <2.0 to 12 mg/L. The maximum of 12 mg/L zinc is used in this analysis as the point estimate for WP-8. If it is assumed that 382,230 gallons of leachant infiltrates WP-8 then seeps to Rock Creek at 10 gpm, then the original volume will be exhausted in 26.5 days. The zinc load contributed by WP-8 would be 1.4 lbs/day (see Table 15).

382,230 gallons/10 gpm (gals/min) = 38,223 min or 8 days

10 gpm x 12 mg/L x 0.0116 (unit conversion) = 1.4 lbs/day

Table 15 Waste Rock Zinc Source Load Estimates

Area

Estimated Leachant Volume (gallons)

Rate of Seepage

(gpm)

Estimated Time to Leach (days)

Leachate Zinc Conc.

(mg/L)

Source Load Estimate

from Seepage (lbs/day)

WP-9,10,13 and 14 116,033 10 8 2.18 0.26

WP-8 382,230 10 26.5 12 1.4

4.3.2.3 Waste Rock Leaching Conclusions

The leachate analysis indicates that leachate from the waste rock contains very low zinc concentrations, and in turn, the resultant zinc loads are small – far too small to explain the observed zinc loading to the river in the spring. In the field, zinc loads generated by snowmelt (DER; Dames & Moore 1997a) are much higher but of shorter duration than developed through the leachate analysis. For example, tributary SR-4 that drains WP-8 generated a zinc load of up to 11 lbs/hour due to zinc concentrations on the order of 200 mg/L (Table 3.2-17 in DER). The elevated zinc concentrations are believed to stem from low volume, short-duration events that wash metal salts off the surface of the pile.

For this report the leachate analyses were used as support for a zinc load estimate of less than 2 lbs/day for all non-Rock Creek waste rock piles, which are all piles except WP-7, WP-8, and WP-11. The zinc load contributed by WP-7, WP-8, and WP-11 is discussed in the next section.

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4.4 ROCK CREEK

Rock Creek receives runoff and seepage from waste rock pile WP-8, lesser amounts from WP-7 and WP-11 and what is thought to be minor seepage from the mine pool in the adjacent Bleakhouse workings. Mine seepage and upstream background are not quantifiable with the direct data measurements. An average zinc load of 2.4 lbs/day is approximately what Rock Creek carries during the late fall when the waste rock piles and runoff diversion systems are dry (see Appendix D). Zinc in Rock Creek surface water is measured at station T-10 (see Figure 2) and the average spring zinc load is shown in Table 5. For simplicity, all Rock Creek zinc loading (approximate average of 8 lbs/day during spring less 2 lbs/day to account for background loading and mine pool seepage = 6 lbs/day) is attributed to runoff and seepage from the waste rock piles listed above. The concentration of metals in Rock Creek is very low and the volume of water is quite high, up to hundreds of gallons per minute in the spring. None of the proposed alternatives directly address Rock Creek surface water (T-10) because the dilution renders all treatment scenarios ineffective and costly.

Groundwater baseflow moving through the steep Rock Creek canyon colluvium also adds zinc to the Segment 5a’s Lower Reach at the confluence with the river (average load of 24.1 lbs/day, see Table 5). Groundwater quality is characterized by samples from wells RX-3 and EDS-3 (Table 16); see Figure 17 for locations.

Table 16 Rock Creek Groundwater Results

Location Sample Date Cadmium

(mg/L) Copper (mg/L)

Zinc (mg/L)

Well RX-3

1/8/09 0.172 0.2 U 86

2/19/09 0.167 0.00652 98

3/11/09 0.319 0.0957 122

3/25/09 0.476 0.0246 203

4/8/09 0.373 0.0116 155

4/20/09 0.541 0.200 147

Well EDS-3

4/20/09 0.317 0.0378 80

3/6/10 0.303 0.0132 99.2

3/17/10 --- --- 83.9

4/4/12 0.168 0.012 48

Notes:

All concentrations are total U Not detected at stated detection limit

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A pump test in the spring of 1995 (Dames & Moore, 1995a) indicated that the maximum yield from a shallow, bedrock-constricted segment of canyon fill (RX-3) was near 5 gpm.

The EDS-3 well is completed in thick colluvium, waste rock, and alluvium at the confluence with the Eagle River and yields 10 gpm in the spring. For this report, the deep well at EDS-3 was selected. It is expected to yield a sustainable zinc load of between 6 and 12 lbs/day.

10 gpm x 48 mg/L x 0.0116 (unit conversion) = 5.7 lbs/day

10 gpm x 99.2 mg/L x 0.0116 (unit conversion) = 11.8 lbs/day

Contributing metal loading sources to Rock Creek groundwater are thought to be 1) upstream, 2) seepage from the mine pool, 3) leaching of metals from the waste rock that has been incorporated as channel fill, and 4) waste rock pile runoff and seepage that recharges the groundwater baseflow. There is not sufficient data to quantify the individual loading sources; however, mine pool seepage has decreased since the inception of the MDD program and control of the mine pool level below 8500 ft mean sea level (MSL). Since the mid-1980s, the concentration of zinc in the mine pool water has also decreased from near 100 mg/L to around 26 mg/L zinc due to submergence of the ore body. The interception and treatment of runoff and seepage from WP-8 continues to reduce the metals that recharge Rock Creek groundwater. As a result, the concentration of zinc in Rock Creek surface water (Figure 18) continues to show measurable decreases with time.

Figure 18 Dissolved Zinc Concentration, Station T-10: Rock Creek

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4.5 OTP AND REX FLATS

The lowermost reach of Segment 5a from E-11 to E-12A through the OTP and Rex Flats has historically experienced small gains and losses of zinc load. The average zinc load gain of 0.7 lbs/day (Table 5) is attributed to groundwater seepage to the river as evidenced by the iron-stained bed and stream bank gravels. Small load losses are variously attributed to precipitation, sorption, and partitioning of zinc to sediments and organics; loss of flow (losing stream); and measurement error.

Surface runoff also contributes a small amount of zinc seasonally. Each spring, snowmelt from the OTP perimeter diversion ditch joins with a small seep of iron-stained water at Tigiwon Road and the combined flow discharges to the river. The combined flow was sampled in April 2009 and Table 17 summarizes the results.

Table 17 OTP Ditch Seep

Sampling Date Flow Cadmium Copper Zinc

4/23/09 20 gpm

(0.045 cfs)

Concentration on Total Basis (mg/L)

0.00534 0.13 0.923

Load (lbs/day)

0.0012 0.03 0.21

Corresponding Flow and Loads at E-12A

4/20/09 196 cfs 1.5 9.1 344

OTP Load as a percent of E-12A Load 0.08% 0.33% 0.06%

The Bolts Lake Remedial Investigation (ERM 2006) presents a summary of the dissolved zinc concentration variations in the Eagle River along the stretch that flows through Rex Flats and the OTP:

“Between stations E-11B and E-12A [see Figure 2 for locations] ground water, seeps, and surface water runoff from the OTP flow into the Eagle River along the eastern edge of the OTP and the northern edge of the Rex Flats. The seeps from the northern edge of Rex Flats were sampled … and contained detectable concentrations of copper, lead, manganese, and zinc. Zinc concentrations [of the seep samples] varied from 82 µg/L to 12,000 µg/L [0.082 to 12 mg/L].”

This reach of the river was sampled by ERM in 2005 and 2006 (Figure 19), and zinc concentrations were found to be relatively stable with no significant gains or losses of zinc. Using the ERM results yields zinc loads from 0.2 to 2.8 lbs/day. For this report, the spring zinc load contributed by the OTP and Rex Flats is between 1 and 3 lbs/day.

20 gpm x 0.082 mg/L x 0.0116 (unit conversion) = 0.2 lbs/day

20 gpm x 12 mg/L x 0.0116 (unit conversion) = 2.8 lbs/day

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Figure 19 Dissolved Zinc Concentrations along Rex Flats and OTP

4.6 SUMMARY OF METAL LOAD SOURCES

The load source estimates in this section were developed independent of the river loading estimates in Section 3. Table 18 provides a summary of the zinc source estimates that are available for use in gauging the effect of the remedial alternatives.

Table 18 Zinc Source Load Estimates, Spring, Segment 5a

Source Estimation Method Spring

Estimated Load lbs/day

Report Reference

Belden groundwater Pump Tests 40 – 80 Section 4.2.1

Rock Creek groundwater EDS-3 Well 6 - 12 Section 4.4

Rock Creek waste rock piles

Rock Creek tributary load (measured at T-10) less background

<6 Section 4.3.2.2

and 4.4

Waste Rock Piles, other than piles in Rock Creek

Leachate <2 Section 4.3.2.2

OTP/Rex Flats Seep estimate 1 – 3 Section 4.5

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IDENTIFICATION OF ARARS AND REMEDIAL ACTION 5.0OBJECTIVES

This section defines several key clean-up concepts common to all feasibility studies prepared in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The concepts included in this section include:

• Applicable or relevant and appropriate requirements (ARARs) and information that is “to be considered” (TBC) in the development of remedial alternatives, and

• Remedial action objectives (RAOs).

ARARs and TBCs constitute the body of existing statutes, regulations, ordinances and guidance pertaining to any and all aspects of potential clean-up actions. This information influences the development of remedial alternatives by establishing numerical clean-up levels, permitting, siting, disposal, operating parameters, health and safety, and monitoring standards. The remedial alternatives selected to be evaluated must meet the substantive requirements of the ARARs and will consider those criteria, advisories, and guidance that are not ARARs but TBC. ARARs encompass all Federal and State regulatory environmental requirements that are to be considered and applied to implementation of the FFS. TBCs are criteria, advisories, guidance and proposed standards that are not legally binding and may provide useful information or recommended procedures for consideration in evaluating specific alternatives.

RAOs are general response clean-up objectives designed to protect human health and the environment.

5.1 IDENTIFICATION OF ARARS

As part of the FFS and in accordance with the NCP [40 CFR 300.430(e)(9)(B)], ARARs were evaluated to ensure that all requirements are met for the scope of work to be performed. As specified in the NCP, an alternative must satisfy two “threshold” criteria specified in order to be eligible for selection: 1) the remedy must be protective of human health and the environment and 2) the remedy must meet (or provide the basis for waiving) the ARARs identified for the action.

Federal standards, requirements, criteria, or limitations that are determined to be ARARs must be met by remedial actions, as required by CERCLA (Section 121(d)(2)(A)). Also, State ARARs must be met if they are more stringent than Federal requirements. ARARs are designed to assure that potential remedial actions at a site are protective of human health and the environment; cost-effective; and use permanent solutions, alternative treatment technologies, or resource recovery technologies (EPA 1988a). The Superfund Amendments and Reauthorization Act (SARA) requires that any hazardous substance or

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pollutant remaining on a site must meet the level or standard of control that is established by the ARARs for that site, unless the ARAR is waived.

Applicable requirements are defined by the NCP as those cleanup standards, standards of control, and other substantive environmental protection requirements, criteria, or limitations promulgated under Federal or State law that specifically address a hazardous substance, pollutant, contaminant, remedial action, location, or other circumstances at a site (40 CFR 300.5).

Although a requirement may not be applicable as a matter of law, it may still be relevant and appropriate. A requirement is deemed relevant and appropriate if it regulates or addresses problems or situations sufficiently similar to those encountered such that it is well suited to that particular site. Determination of whether a requirement is relevant and appropriate is site-specific and determined by professional judgment based on the characteristics of the remedial action, the hazardous substances present at the site, and the physical circumstances of the site and of the release. In addition, only a portion of a requirement may be deemed relevant and appropriate (EPA 1988b).

Compliance with all requirements found to be applicable or relevant and appropriate is required under SARA. A waiver from an ARAR may be obtained under certain circumstances (CERCLA Section 121(d)(4)). CERCLA Section 121(d)(2)(A) specifically limits the scope of State ARARs to standards, requirements, criteria, or limitations under environmental or facility siting laws that are promulgated and more stringent than Federal requirements.

ARARs are grouped into three categories:

• Chemical Specific

• Location Specific

• Action Specific.

The NCP identifies a fourth category of information termed “to be considered” (TBC) when evaluating appropriate remedial action goals or approaches. This fourth category generally includes Federal and State advisories, criteria or guidance that are not ARARs, and while not legally binding may be useful in developing CERCLA remedies (see 40 CFR 300.400(g)(3)). These TBCs are not addressed separately but have been included in the other three categories as applicable.

The following sections provide a discussion of those requirements that have significant potential to be applicable or relevant and appropriate to remedial actions at the Eagle Mine Site.

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5.1.1 Potential Chemical-Specific ARARs and TBCs

Chemical-specific requirements are based on health- or risk-based concentration limits or discharge limitations in environmental media (i.e., water, soil, air) for specific hazardous chemicals. These requirements may be used to set cleanup levels for the chemicals of concern in the designated media or to set a safe level of releases where releases occur as part of the remedial activity.

Sources for potential target cleanup levels include selected standards, criteria, and guidelines that are typically considered ARARs for remedial actions conducted under CERCLA. Potential chemical-specific ARARs, as well as potential chemical-specific TBCs, are presented in Table 19.

5.1.2 Potential Location-Specific ARARs and TBCs

Location-specific ARARs are restrictions placed on the types of remedial activities that may be implemented at particular site locations. The location of a site may be an important factor in determining the potential impact of remedial actions on human health and the environment. These ARARs may restrict or preclude certain remedial actions or they may apply only to certain portions of a site. Potential Federal and State location-specific ARARs, as well as potential location-specific TBCs, are presented in Table 20.

5.1.3 Potential Action-Specific ARARs and TBCs

Action-specific ARARs are usually technology or activity-based requirements or limitations on actions taken with respect to hazardous substances. These requirements are triggered by the remedial activities selected to accomplish a remedy. Because there may be several alternative actions for any site, different requirements may be established. The action-specific requirements do not in themselves determine the remedial alternative; rather, they indicate how a selected alternative should be implemented to achieve the requirement.

Table 21 lists and describes potential Federal and State action-specific ARARs as well as potential action-specific TBCs. Regulations regarding worker health and safety such as Occupational Safety and Health Administration (OSHA) requirements are included in the table; however, because they are not environmental requirements they are not technically ARARs.

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Table 19 Potential Federal and State Chemical-Specific ARARS

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

AIR

FEDERAL REQUIREMENTS

Clean Air Act - National Ambient Air Quality Standards (NAAQS)

40 CFR Part 50, pursuant to 42 USC § 7409 et seq.

These regulations establish ambient air quality standards for emissions of lead and particulate matter. Remedial actions taken are likely to result in release of airborne lead and dust. These regulations are applicable to “major sources” as defined under the Clean Air Act. Although remediation sites in the Site are not expected to be major sources, these regulations would be relevant and appropriate during construction activities at the site.

Relevant and Appropriate

Clean Air Act - National Emission Standards for Hazardous Air Pollutants

40 CFR Part 61, Subparts N, O, P pursuant to 42 USC § 7412

Sets emission standards for certain industrial pollutants and sources. No air emissions are expected after remediation.

Relevant and Appropriate

STATE REQUIREMENTS

Colorado Primary and Secondary Ambient Air 5 CCR 1001-14, pursuant to CRS § 25-7-108

Sets ambient air quality standards for a variety of constituents, including particulate matter and lead.

Relevant and Appropriate

Colorado Emission Standards for Hazardous Air Pollutants

5 CCR 1001-10, pursuant to CRS § 25-7-108

Sets emission standards for designated hazardous pollutants, including inorganic arsenic emitted by specified industrial operations.

Relevant and Appropriate

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Table 19 Potential Federal and State Chemical-Specific ARARS

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

SOILS

FEDERAL REQUIREMENTS

Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities.

EPA/540/F-94/043, OSWER Directive No. 9355.4-12. August 1994

Recommends a screening level of 400 ppm for lead in residential soils. Describes a methodology for developing site-specific preliminary remediation goals and media cleanup standards. Describes a plan for soil lead cleanup at sites with multiple sources of lead and provides guidance for evaluating the extent to which proposed remedial actions might enhance protection of human health.

TBC

Soil Screening Guidance and supplements OSWER Directive 9355.4-23, July 1996

OSWER Directive 9355.4-24, December 2002

Recommends the development of site-specific soil screening levels. Provides general screening levels below which areas are determined to be adequate and do not need further assessment. Further evaluation of risks is recommended for areas above the screening levels.

TBC

Toxic Substances Control Act – PCB Requirements

40 CFR Part 761, pursuant to 15 USC § 2605(e)

Establishes disposal requirements for PCBs. No

Toxic Substances Control Act – PCB Spill Cleanup Policy

52 FR 10688 April 2, 1987 Guidance for cleanup levels for PCB-impacted soils. No

STATE REQUIREMENTS

Colorado Soil Evaluation Values (CSEV) http://www.cdphe.state.co.us/hm/csev.htm

Provides calculated generic soil remediation objectives that are deemed to be protective of groundwater quality.

TBC

EPA Regional Screening Levels (RSLs)

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/index.htm

Provides calculated direct exposure levels for residential and industrial exposure scenarios deemed protective of human health.

TBC

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Table 19 Potential Federal and State Chemical-Specific ARARS

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

SURFACE WATER

FEDERAL REQUIREMENTS

Clean Water Act – Water Quality Standards 40 CFR § 131, pursuant to 33 USC §§ 1313-1314

Sets criteria for surface water quality based on toxicity to aquatic organisms and human health. Requires EPA and the State to establish ambient water quality control criteria (AWQC) and standards for surface water based on use classifications and the criteria stated under sections 303 and 304(a) of the Clean Water Act. Would only be relevant and appropriate in the absence of segment specific state standards.

Relevant and Appropriate

STATE REQUIREMENTS

Colorado Basic Standards and Methodologies for Surface Water

5 CCR 1002-31, pursuant to CRS §§ 25-8-101-703

Establishes Statewide water quality standards, specific surface water quality standards, and an antidegradation rule.

Applicable

Colorado Surface Water Quality Classifications and Numeric Standards

5 CCR 1002-33, pursuant to CRS §§ 25-8-203 and 204

Assigns Statewide water quality standards and classifications for State surface and ground waters. Water Quality Control Commission issued a Final Rule effective January 1, 2009 for Segments 5 and 7 of the Eagle River Basin.

Applicable

Clean Water Act – Section 303(d) Total Maximum Daily Loads (TMDLs)

5-CCR 1002-93 Only those stream segments where a CWA Section 303(d) impairment has been determined require TMDLs. Since relevant Eagle river segments - 5a, 5b, and 7b - are not listed as impaired waters in WQCC Regulation 93, 5 CCR 1002-93, TMDLs to not imply.

No

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Table 19 Potential Federal and State Chemical-Specific ARARS

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

GROUNDWATER

FEDERAL REQUIREMENTS

SDWA National Primary Drinking Water Standards (MCLs)

40 CFR Part 141, Subpart B, pursuant to 42. USC §§ 300g-1 and 300j-9

Establishes maximum contaminant levels (MCLs) for specific contaminants, which are health-based standards for public drinking water systems.

TBC

SDWA National Secondary Drinking Water Standards

40 CFR Part 143, pursuant to 42. USC §§ 300g-1(c) and 300j-9

Establishes secondary maximum contaminant levels (SMCLs) which are non-enforceable guidelines for public drinking water systems to protect the aesthetic quality of the water.

TBC

SDWA Maximum Contaminant Level Goals (MCLGs)

40 CFR Part 141, Subpart F pursuant to 42 USC § 300g-1

Establishes drinking water quality goals set at levels of no known or anticipated adverse health effects, with an adequate margin of safety.

TBC

RCRA Groundwater Protection Standard (GPS)

40 CFR §§ 264.92 – 264.101 Establishes provisions regarding hazardous constituents in groundwater. Relevant and Appropriate

STATE REQUIREMENTS

Colorado Primary Drinking Water Standards 5 CCR 1003-1, pursuant to CRS § 25-1.5-203

Establishes health-based standards (MCLs) for public drinking water systems.

TBC

Colorado Basic Standards for Groundwater 5 CCR 1002-41, pursuant to CRS §§ 25-8-101-703

Establishes basic Statewide water quality standards for groundwater, specific water quality standards for groundwater, and an antidegradation rule.

Relevant and Appropriate

Colorado Groundwater Protection Standard (GPS)

6 CCR 1007-3 Establishes provisions regarding hazardous constituents in groundwater (numeric standards).

Relevant and Appropriate

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Table 20 Potential Federal, State, and Local Location-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

FEDERAL REQUIREMENTS

Archaeological and Historic Preservation Act 40 CFR § 6.301(c) pursuant to 16 USC § 469

Establishes procedures to provide for preservation of historical and archaeological data that might be destroyed through alteration of terrain as a result of a Federally licensed activity or program.

Relevant and Appropriate

Archaeological Resources Protection Act 16 USC §§ 470 aa - mm Requires permits for any excavation or removal of archaeological resources from public or Indian lands. Provides guidance for federal land managers to protect such resources.

Relevant and Appropriate

National Historic Preservation Act 16 USC § 470

40 CFR § 6.301(b)

36 CFR Parts 63, 65, 800

Requires Federal agencies to take into account the effect of any Federally assisted undertaking or licensing on any district, site, building, structure, or object that is included in or eligible for Register of Historic Places.

Relevant and Appropriate

Protection and Enhancement of the Cultural Environment

Executive Order 11593, May 3, 1971 40 CFR § 6.301(a)

Institutes procedures to ensure programs contribute to the preservation and enhancement of non-federally owned historic resources. Requires consultation with the Advisory Council on Historic Preservation.

Relevant and Appropriate

Historic Sites, Buildings, and Antiquities Act 40 CFR § 6.301(a) pursuant to 16 USC §§ 461-467

Requires Federal agencies to consider the existence and location of landmarks on the National Registry of Natural Landmarks to avoid undesirable impacts on such landmarks.

Relevant and Appropriate

Farmland Protection Policy Act 40 CFR § 6.302 (c) pursuant to 7 USC § 4201 et. seq.

Protects significant or important agricultural lands from irreversible conversion to uses that result in its loss as an environmental or essential food production resource.

No

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Table 20 Potential Federal, State, and Local Location-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

RCRA – Location Standards for Hazardous Waste Facilities

40 CFR 264.18 pursuant to 42 USC § 6901

Requires that any hazardous waste facility located within the 100-year floodplain be designed, constructed, operated, and maintained to avoid washout. Also, contains requirements for locating facilities away from seismically active zones. These requirements may be applicable for materials not subject to Bevill Amendment, and, notwithstanding the Bevill Amendment, may be relevant and appropriate for wastes sufficiently similar to RCRA hazardous wastes (e.g., low volume and high toxicity). See 55 Fed. Reg. 8763.

Relevant and Appropriate

RCRA Subtitle D Restrictions on Location of Treatment, Storage, and Disposal Facilities

40 CFR Part 258 Establishes minimum national criteria under RCRA for all municipal solid waste landfills (MSWLF) and under the Clean Water Act for municipal solid waste landfills used to dispose of sewage sludge, to ensure the protection of human health and the environment.

TBC

Rivers and Harbors Act Section 10 Permit, 33 USC § 403, 33 CFR §§ 320 - 330

Requires pre-approval by the US Army Corps of Engineers prior to placement of any structures in navigable waterways and restricts the placement of structures and fill in such waterways.

No

Executive Order on Floodplain Management Executive Order No. 11988

40 CFR § 6.302(b) and Appendix A

Requires Federal agencies to evaluate the potential effects of actions they may take in a floodplain to avoid, to the maximum extent possible, the adverse impacts associated with direct and indirect development of a floodplain.

TBC

Clean Water Act - Dredge or Fill Requirements (Section 404)

33 USC § 1344, 40 CFR Parts 230 and 231, 33 CFR Part 323

Regulates the discharge of dredged or fill material into waters of the U.S and associated wetlands.

Applicable

Executive Order on Protection of Wetlands Executive Order No. 11990

40 CFR § 6.302(a) and Appendix A

Requires Federal agencies to avoid, to the maximum extent possible, the adverse impacts associated with the destruction or loss of wetlands and to avoid new construction in wetlands, if a practicable alternative exists.

TBC

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Table 20 Potential Federal, State, and Local Location-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Wilderness Act 16 USC § 1131; 50 CFR 35, 50 CFR 27

Limits activities within areas designated as wilderness areas or National Wildlife Refuges.

No

Wild and Scenic Rivers Act 16 USC §§ 1271-1287, 40 CFR § 6.302(e), 36 CFR Part 297

Protects rivers that are designated as wild, scenic, or recreational by establishing requirements applicable to water resource development affecting rivers within or studied for including in the National Wild and Scenic Rivers system.

No

Fish and Wildlife Coordination Act 16 USC §§ 661-666

40 CFR § 6.302(g)

Requires any Federal agency or permitted entity to consult with the U.S. Fish and Wildlife Service and appropriate state agency prior to modification of any stream or other water body. The intent of this requirement is to conserve, improve, or prevent loss of wildlife habitat and resources. Applies through the 404 process per § 404(q).

Relevant and Appropriate

Fish and Wildlife Conservation Act 16 USC §§ 2901 - 2912 Requires Federal agencies to utilize their statutory and administrative authority to conserve and promote conservation of non-game fish and wildlife species.

TBC

Endangered Species Act 16 USC §§ 1531-1544

50 CFR Parts 17, 402

40 CFR § 6.302(h)

Requires that Federal agencies ensure that any action authorized, funded, or carried out by the agency is not likely to jeopardize the continued existence of any threatened or endangered species or destroy or adversely modify critical habitat.

Relevant and Appropriate

Federal Migratory Bird Treaty Act 16 USC §§ 703 - 712 Establishes federal responsibility for the protection of international migratory bird resources from pursuit, hunt, take, capture or kill from hunters and poachers. Requires remedial actions to conserve habitat and consultation with the Department of Interior if any critical habitat is affected.

Relevant and Appropriate

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Table 20 Potential Federal, State, and Local Location-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Bald and Golden Eagles Protection Act 16 USC §§ 668 Prohibits the taking, possession, sale, purchase, barter, transport, export/import at any time or in any manner, any bald (American) or any golden eagle, alive or dead, or any part, nest, or egg; establishes civil and criminal penalties (where “take” has been construed to affect habitat as well as physical possession of the eagles).

Relevant and Appropriate

STATE REQUIREMENTS

Colorado Historic Preservation Act CRS §§ 24-80-101-107, 8 CCR 1504-7, § 10(B)(3)(b)

Establishes requirements for protecting properties of historical significance; establishes procedures and requires a permit for investigation, excavation, gathering, or removal from the State of any historical, prehistorical, or archeological resources on State lands. Requires an excavation permit and notification if human remains are found on State lands. Note: the National Historic Preservation Act is more stringent.

TBC

Colorado Guidelines for the Land Disposal of Solid Wastes

6 CCR 1007-2, pursuant to CRS §§ 30-20-101-515

Establishes requirements and procedures for land disposal of solid wastes.

No

Colorado Mined Land Reclamation Act CRS §§ 34-32-101 et seq. and regulations 2 CCR 407-1

Regulates all aspects of mining, including location of operations, reclamation, and other environmental and socioeconomic impacts.

Relevant and Appropriate

Colorado Noxious Weed Act and the Eagle County Noxious Weed regulations

CRS § 35-5.5-101-119; 8 CCR 1203-19

Colorado Regulations addressing management of noxious weeds. Relevant and Appropriate

Colorado Mined Land Reclamation Board Guideline for the Management of Noxious Weeds at Hard Rock and Construction Material Mining Operation

Guidance Guidance for management of noxious weeds. TBC

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Table 20 Potential Federal, State, and Local Location-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Colorado Natural Areas CRS § 33-33-104 Maintains a list of plant species of special concern for the State. Coordination with the Division of Parks and Outdoor Recreation is recommended if activities will impact listed species within a designated “natural area.” No designated natural areas are within the site.

No

Colorado Wildlife Enforcement and Penalties Act

CRS §§ 33-1-101 to 124 Prohibits actions detrimental to wildlife, and establishes provisions governing the taking, possession, hunting and use of wildlife and migratory birds.

Applicable

Colorado Non-game, Endangered, or Threatened Species Act

CRS §§ 33-2-101-108 Protects endangered and threatened species and preserves their habitats. Requires coordination with the Division of Wildlife if remedial activities impact State-listed endangered or threatened species or their habitats.

Applicable

Colorado Wildlife Commission Regulations 2 CCR 406-10, pursuant to CRS §§ 33-2-101-108

Establishes specific requirements for protection of wildlife. Relevant and Appropriate

Colorado Species of Special Concern and Species of Undetermined Status

Colo. Administrative Directive E-1, 1985, modified

Protects animals listed on the Colorado Division of Wildlife-generated list. Coordination with the Division is strongly urged if animal species are to be impacted. Relevant and appropriate, with applicable protection covered under other ARARs.

Relevant and Appropriate

Colorado Environmental Covenants CRS §§ 25-15-317-327 Required where remediation results in residual COC levels determined by regulatory agency not to be safe for all uses, or where remediation incorporates any engineered feature or structure or requires any monitoring, or maintenance, or operation, unless eligible for exemption as provided under § 25-15-320.

Relevant and Appropriate

Tamarisk and Russian Olive Management at Permitted Mine Sites (January 19, 2005)

Guidance Guidance addressing the management of Tamarisk and Russian Olive weeds from permitted mining sites and reclamation areas.

TBC

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

FEDERAL REQUIREMENTS

Clean Air Act - National Emission Standards for Hazardous Air Pollutants

40 CFR Part 61, Subparts N, O, P pursuant to 42 USC § 7412

Sets emission standards for certain industrial pollutants and sources. No air emissions will be expected after remediation.

Relevant and Appropriate

RCRA Subtitle D, Solid Waste Regulations 40 CFR Part 257, Criteria for Classification of Solid Waste Disposal Facilities and Practices, pursuant to 42 USC § 6941

This section of the RCRA regulations requires the closure of existing solid waste facilities, design of new landfills, and disposal of solid wastes to be in accordance with numerous standards and criteria. These standards are applicable to solid waste disposal facilities, including mining and mill waste facilities. Among other things, these regulations require that facilities be maintained to prevent wash out of solid wastes and that the public not be allowed uncontrolled access.

Relevant and Appropriate

RCRA Hazardous Waste Management System 40 CFR Parts 260 - 270 Establishes requirements regulating the use and handling of hazardous waste. These requirements may be applicable for materials not subject to Bevill Amendment, and, notwithstanding the Bevill Amendment, may be relevant and appropriate for materials sufficiently similar to RCRA hazardous wastes (e.g., low volume and high toxicity). See 55 Fed. Reg. 8763.

Relevant and Appropriate

RCRA, Subtitle C, Identification and Listing of Hazardous Wastes

RCRA Section 3001(b)(3)(A)(iii), Bevill exclusion of mineral extraction and beneficiation wastes. 40 CFR Part 260 et seq.

Mine and mill wastes are specifically excluded from regulation as hazardous wastes under the Bevill exclusion because they are wastes resulting from mineral extraction and beneficiation. Therefore, the RCRA Subtitle C regulations are not applicable to excluded wastes. However, these regulations are relevant and appropriate because of the guidance they provide regarding the mining and milling waste exclusion and, notwithstanding the Bevill Amendment, may be considered for materials sufficiently similar to RCRA hazardous wastes (e.g., low volume and high toxicity). See 55 Fed. Reg. 8763.

Relevant and Appropriate

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

RCRA, Subtitle C, Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities

RCRA Section 3001 et seq. 40 CFR Part 264.522, Disposal of Hazardous Wastes in Designated Corrective Action Management Units (CAMUs), pursuant to 42 USC § 6921, et seq.

The section defines Corrective Action Management Units (CAMUs) to be used in implementing corrective actions at Superfund Sites. A CAMU is defined as a disposal site used for consolidation or placement of remediation wastes within the impacted areas of the Site. Under these regulations, placement of wastes in a CAMU does not constitute land disposal of hazardous waste and does not constitute creation of a unit subject to the RCRA land disposal restrictions and minimum technology requirements (40 CFR, Part 268).

Relevant and Appropriate

Surface Mining Control and Reclamation Act (SMCRA)

30 CFR Part 816, pursuant to 30 USC §§ 1201-1328

SMCRA regulations govern coal exploration and active coal mining. Hence, these regulations are not applicable. Nevertheless, some of the surface mining standards found in 30 CFR Part 816 are relevant and appropriate requirements because they address circumstances that are similar to those found at the Site. The relevant and appropriate requirements include Part 816.45, Sediment Control Measures; Part 816.46, Siltation Structures; Part 816.102, Grading Requirements; and Part 816. 111, Revegetation.

No

RCRA Guidelines for the Thermal Processing of Solid Wastes

40 CFR Part 240, pursuant to 42 USC §§ 6901- 6992i

Prescribes guidelines for thermal processing of municipal-type solid wastes.

No

RCRA Guidelines for the Storage and Collection of Residential, Commercial and Institutional Solid Waste

40 CFR Part 243 Establishes guidelines for collection of residential, commercial, and institutional solid wastes.

No

RCRA Source Separation for Material Recovery Guidelines

40 CFR Part 246 Establishes requirements and recommended procedures for source separation by federal agencies of residential, commercial, and institutional solid wastes.

No

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

RCRA Guidelines for Development and Implementation of State Solid Waste Management Plans

40 CFR Part 256

Establishes requirements for federal approval of state programs to regulate open dumps.

No

RCRA Underground Storage Tanks 40 CFR Part 280 Establishes regulations related to underground storage tanks. No

Uranium Mill Tailings Radiation Control Act (UMTRA)

42 USC §§ 7901-7942, 42 USC §§ 2011

Establishes requirements related to uranium mill tailings. No

Standards for the use and disposal of sewage sludge

40 CFR 503 Establishes standards for the final use or disposal of sewage sludge generated during the treatment of domestic sewage in a treatment works.

No

Hazardous Materials Transportation Act 49 USC §§ 5101-5127 Regulates transportation of hazardous materials. Would be applicable for the transport of excavated materials off of the Site.

Relevant and Appropriate

DOT Hazardous Materials Transportation Regulations

49 CFR Parts 107, 171-177 Regulates transportation of hazardous materials. Would be applicable for the transport of excavated materials off of the Site.

Relevant and Appropriate

Clean Water Act – Dredge or Fill Requirements (Section 404)

40 CFR Parts 230, 231, pursuant to 33 USC §§ 1251-1376 33 CFR Part 323 pursuant to 33 USC § 1344

Regulates discharge of dredged or fill material into navigable waters and the destruction of wetlands.

Applicable

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Clean Water Act – National Pollution Discharge Elimination System (NPDES)

40 CFR Parts 122, 125, 440 pursuant to 33 USC § 1342

Requires permits for any discharge, including storm water, of pollutants from a point source into waters of the U.S. and sets technology and water quality-based effluent limitations for such discharges.

Applicable

Toxic Pollutant Effluent Standards 40 CFR Part 129 pursuant to 33 USC § 1317

Sets effluent standards and prohibition of certain pollutants: aldrin, dieldrin, DDT, endrin, toxaphene, benzidine, and PCBs.

No

Clean Water Act – General Pretreatment Regulations for Existing and New Sources of Pollution

40 CFR Part 403, pursuant to 33 USC § 1317

Sets standards to control pollutants that pass through or interfere with treatment processes in publicly owned treatment works (POTW) or that may impact sewage sludge. None of the alternative remedies contemplate the discharge to a POTW.

No

Safe Drinking Water Act – Underground Injection Control Program

40 CFR Part 144 – 148, pursuant to 42 USC §§ 300f – 300j

Regulates disposal of wastes in underground injection wells to ensure protection of drinking water sources.

Relevant and Appropriate

Bald and Golden Eagles Protection Act 16 USC §§ 668 Prohibits the taking, possession, sale, purchase, barter, transport, export/import at any time or in any manner, any bald (American) or any golden eagle, alive or dead, or any part, nest, or egg; establishes civil and criminal penalties (where “take” has been construed to affect habitat as well as physical possession of the eagles).

Relevant and Appropriate

Federal Migratory Bird Treaty Act 16 USC §§ 703 - 712 Requires remedial actions to conserve habitat and consultation with the Department of Interior if any critical habitat is affected. Site is not considered critical habitat. None of the remedies evaluated contemplate the destruction of critical habitat.

Relevant and Appropriate

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Occupational Safety and Health Act 29 USC §§ 651-678 Regulates worker health and safety. No, but would apply independently

Federal Mine Safety and Health Act 30 USC §§ 801 – 962 Regulates working conditions in underground mines to assure safety and health of workers.

No, but would apply independently

STATE REQUIREMENTS

Colorado Fugitive Dust Control Plan/Opacity. 5 CCR 1001-3, pursuant to Colorado Air Pollution Prevention and Control Act, CRS §§ 25-7-101 et seq.

Establishes regulations concerning fugitive emissions from construction activities, storage and stockpiling activities, haul trucks, and tailings ponds.

Applicable

Colorado Environmental Covenants CRS §§ 25-15-317-327 Required where remediation results in residual COC levels determined by regulatory agency to be safe for all uses, or where remediation incorporates any engineered feature or structure or requires any monitoring, or maintenance, or operation, unless eligible for exemption as provided under § 25-15-320

Relevant and Appropriate

Colorado Guidelines for the Land Disposal of Solid Wastes

6 CCR 1007-2, pursuant to CRS §§ 30-20-101 et seq.

Establishes requirements and procedures for land disposal of solid wastes.

No

Colorado Hazardous Waste Permit Program 6 CCR 1007-3, pursuant to CRS §§ 25-15-101 et seq.

Establishes provisions covering basic permitting requirements for hazardous waste. No permit required for onsite CERCLA response.

No

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Colorado Hazardous Waste Management System: General

6 CCR 1007-3, Parts 260 – 268

Establishes requirements regulating the use and handling of hazardous waste.

No

Colorado Biosolids Regulations 5 CCR 1002-64 Establishes requirements, prohibitions, standards, and concentration limitations on use of biosolids as fertilizer and/or organic soil amendment in a manner that protects public health and prevents the discharge of pollutants into State waters.

No

Colorado Mined Land Reclamation Act CRS §§ 34-32-101 et seq. and regulations 2 CCR 407-1

Regulates all aspects of mining, including location of operations, reclamation, and other environmental and socioeconomic impacts.

Relevant and Appropriate

Colorado Ground Water Management Act

Application to Appropriate Water

Permits

Diversion of Water Prohibited

CRS 37-90-101 et seq. Identifies tributary and nontributary groundwater and presents how the water resource of the state devoted to beneficial use in reasonable amounts through appropriation with respect to groundwater. Well permit requirements. Wells within a CERCLA site do not require a permit.

Relevant and Appropriate

Colorado Water Well Construction and Pump Installation contractors

Water Well Contractor's License

Water Well Construction and Abandonment

CRS 37-91-101 et seq. Identifies the proper location, construction, repair, and abandonment of wells, the proper installation and repair of pumping equipment, and the licensing and regulation of persons engaging in the business of contracting either for the construction of wells or for the installation of pumping equipment. Wells within a CERCLA site do not require a permit.

Relevant and Appropriate

Colorado Regulations Controlling Discharges to Storm Sewers

5 CCR 1002-61, pursuant to CRS § 25-8-501

Establishes permitting requirements for discharges of pollutants from point sources to storm sewers.

No

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Table 21 Potential Federal and State Action-Specific ARARs

Standard, Requirement, Criteria, or Limitation

Citation Description Potential

ARARs or TBC

Colorado Basic Standards and Methodologies for Surface Water

5 CCR 1002-31, pursuant to CRS §§ 25-8-101-703

Establishes Statewide water quality standards, specific surface water quality standards, and an antidegradation rule.

Applicable

Colorado Discharge Permit System Regulations

5 CCR 1002-61, Regulation No. 61, pursuant to CRS § 25-8-503 (501-509)

Establishes program for permitting discharges of COCs into waters of the United States within Colorado. Disturbing 5 acres trigger storm water controls, which are subject to best management practices, and additional controls to maintain WQS.

Applicable

Colorado Effluent Limitations 5 CCR 1002-62, §§ Regulation #62, pursuant to CRS § 25-8-205

Sets effluent limitations for point source discharges. Applicable

Colorado Wildlife Enforcement and Penalties Act

CRS §§ 33-1-101 to 120 Prohibits actions detrimental to wildlife, and establishes provisions governing the taking, possession, hunting and use of wildlife and migratory birds.

Relevant and Appropriate

Colorado Wildlife Commission Regulations 2 CCR 406-10, pursuant to CRS §§ 33-2-101 et seq.

Establishes specific requirements for protection of wildlife. Relevant and Appropriate

Regulations on the Collection of Aquatic Life 2 CCR 406-8, § 1316 Requirements governing the collection of wildlife for scientific purposes. Relevant and Appropriate

Colorado Noise Abatement Statute CRS §§ 25-12-101 et seq. Establishes maximum permissible noise levels for particular time periods and land use zones.

Relevant and Appropriate

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5.2 REMEDIAL ACTION OBJECTIVES

Remedial action objectives (RAOs) are defined in this section. EPA guidance states that RAOs should be expressions of medium-specific risk prevention goals and must specify the following:

• The chemicals of concern (COCs) identified for the site

• Exposure routes and receptors

• Acceptable COC levels for each identified exposure route.

EPA identified arsenic, cadmium, copper, lead and zinc as the COCs in the Record of Decision (ROD) for the mine site, or Operable Unit No. 1 (EPA 1990). For the former town of Gilman, or Operable Unit No. 2, human health risks were evaluated using arsenic, cadmium, chromium, and manganese (EPA 1998). Region VIII of the EPA, in which the Eagle Mine Site is located, the CDPHE, and a risk assessment for OU-3 (North Property Redevelopment for Ginn Resorts; ERM, 2007a) have identified the following metals of concern at the Eagle Mine Site: arsenic, cadmium, chromium, copper, lead, manganese and zinc.

Cadmium, copper, and zinc were previously identified as COCs in the many aquatic studies that have been performed at this Site. Subsequent studies have identified no unique characteristics that would warrant consideration of other metals for inclusion in the river COCs. The FFS is focused on the protection of aquatic receptors therefore cadmium, copper, and zinc make up the list of COCs. This COC list is a subset of those contained in the ROD for OU-1 and OU-2; however, it is specific to the FFS and does not imply that the COC list has been formally altered.

Aquatic receptors are exposed to the COCs through respiration, ingestion and dermal absorption. The acceptable COC level is the hardness-based WQS for Segment 5. Therefore, the RAO for the FFS is:

For Segment 5, prevent the exposure of biota in the Eagle River to cadmium, copper, and zinc concentrations that exceed Colorado Water Quality Standards by controlling the release and transport of these COCs from Site sources.

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IDENTIFICATION AND SCREENING OF RESPONSE 6.0ACTIONS

The first step in the identification and screening process consists of identifying general response actions (GRAs) that address the potential risks associated with source materials and affected media specifically identified at the site. GRAs are defined as broad groupings of remedial technologies or technology types that share common elements for addressing the RAO identified in Section 5.2. Technology types are subdivisions within the GRAs that describe related process options. Process options consist of specific remedial actions that fall within a general technology type.

6.1 IDENTIFICATION OF RESPONSE ACTIONS

This identification of GRAs and related technologies is based on an understanding of site conditions, characterization data, engineering judgment, experience, and knowledge of the technologies’ applicability under site-specific conditions. GRAs are general categories of removal activities that may be taken, either singly or in combination, to satisfy the RAO.

GRAs that are pertinent to the FFS include:

No Added Action – Evaluation of a no action GRA is required by the NCP [40 CFR Part 300.430(e)6]. This category is designated “No Added Action” since it takes into consideration the ongoing remedial actions, monitoring, and access restrictions that have been put in place by CBS, its predecessors, and the current property owners.

Capping and Containment – This response action includes physical restrictions on COC mobility. Containment technologies for surface mine wastes and associated soils include covering and surface control.

• Covering – Containment of mine wastes is achieved by installation of engineered covers to prevent direct contact. There are a variety of available engineered cover designs, including simple soil, rock/gravel, geosynthetic liners and membranes, asphalt, concrete and multimedia (for example, soil-synthetic membrane, soil-synthetic membrane-clay caps, etc.).

• Surface Control – Surface controls may include grading, vegetation or tilling. Grading typically entails contouring the ground surface to reduce rills and erosion. Vegetation consists of seeding with grass, legume or shrub species to provide a stand of vegetation that will reduce erosion and stabilize soils. Tilling includes mechanically turning over and mixing of the upper soil column such that COC levels at the surface are reduced. Vegetation would not be effective as a

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stand-alone solution, but could be used as a component of a tilling and restoration alternative.

Collection and Treatment – Technologies identified under this GRA include those designed to control and divert surface water inflows or subsurface flow for the purpose of reducing COC loadings that cause WQS exceedance in the Eagle River. Collection process options include the direct physical removal of the COC source. Collection is paired with treatment to develop a complete process option. Treatment process options include both onsite and offsite measures to render the impacted materials less hazardous. Onsite or in situ treatment may include iron-rich material (IRM) or other materials in collected water or in a permeable reaction barrier (PRB). These processes may be combined with surface controls.

Excavation and Disposal – Measures to relocate COCs in such a way as to reduce their interaction with the environment.

6.2 FRAMEWORK FOR INSTITUTIONAL CONTROLS

This section provides information on options for institutional controls (ICs) that will be used to protect the remediation required by the alternatives designed to address the RAO. ICs are defined as non-engineered access or land use restrictions designed to reduce or prevent residual human health or ecological risks that may remain following the implementation of engineered remedial actions at CERCLA sites. The use of ICs to supplement engineering remedies has undergone rigorous study and evolution since CERCLA was enacted in 1980. Since that time, legal and administrative controls have been used successfully to help reduce or prevent risks at numerous mining-related sites.

ICs are useful for improving long-term protectiveness of engineering controls. Land use regulations and health ordinances to enhance a remedy’s protectiveness of human health are included here for completeness, noting however, that the focus of the FFS is the reduction of risks to the environment and not human health.

The land use restriction and access controls that are potentially applicable to conditions in the Site include the following.

• Access controls to prevent human exposure to waste rock piles or to protect the engineered components of remedial actions from human disturbance or destruction – Access controls include physical barriers, such as fencing and warning signs; surveillance, including site security systems, guards, or alarms; and legal controls on access, such as enforceable prohibitions on trespassing.

• Dedication of land for public uses, such as park land, open space, public recreation, or other public uses – Public acquisition of real property interests may

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be an appropriate means of ensuring long-term maintenance, management, and protection of remediated sites or waste repositories because the public entity that acquires the interest may be best equipped to control public access and uses of the sites. Also, public funds can be expended to manage or maintain the sites in exchange for the benefit the public receives from public ownership or access. EPA is generally supportive of public ownership of lands as a general response action to control access and protect human health and the environment provided some engineering controls are utilized in such projects to adequately prevent releases or exposures to hazardous substances.

• Land use restrictions that run with the land to ensure long-term protection of remediated sites or waste repositories – Land use restrictions could include deed restrictions, local zoning restrictions, Environmental Use Controls, easements, fee simple acquisition, and other agreements affecting real property interests. Environmental Covenants or Notices of Environmental Use Restrictions will be required where waste is left in place above levels allowing unrestricted use and where engineered features have been constructed as part of the remedy.

• Environmental construction codes to prevent unsafe exposures to soils, mine/mill wastes or to prevent disturbance of remediated sites – Environmental construction codes would consist of special building permits for mine-affected or remediated areas that could be used to place a variety of conditions on receiving a certificate of occupancy for new construction. These conditions could include requirements, such as meeting erosion control standards or implementing site revegetation plans.

• Zoning ordinances and other types of governmental land use regulations to control new development on mine-affected, remediated sites, or waste repositories – Zoning ordinances and/or county-wide master plans are commonly used throughout the U.S. to control land use. However, such requirements must be adopted by a governing body and can be subject to amendment in the future.

• Surface water access controls, use restrictions, and regulations designed to prevent access to affected surface waters to prevent exposure – Surface water use restrictions include legal controls on the use of surface water, such as prohibiting contact recreation, fishing, and/or use as irrigation or domestic water supplies.

The ICs currently used at the Site are simple access controls; there are no zoning restrictions or Environmental Covenants in place. All the alternatives are on private land and more comprehensive ICs may need to be implemented as part of the remedy including stricter access controls, land use controls, or legal agreements for long-term maintenance, management, and protection of remediated areas, repositories, and consolidated waste areas.

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6.3 DESCRIPTION OF REMEDIAL ALTERNATIVES

The process options are organized into alternatives that address the three of the primary metal sources, as described in Section 4.0:

• Eagle Mine Seepage to Belden and Rock Creek

• Waste Rock Piles

• Rex Flats and OTP.

The alternatives are listed in Table 22, a site-specific list developed for the FFS in cooperation with the EPA and CDPHE and with input from local stakeholders.

Table 22 List of Alternatives

General Response Action

Description

No Action Alternative

No added action Surface ditches, runon diversion and collection of runoff and seepage MDD, Liberty well diversion, Copper Tipple Trench, groundwater and Eagle River Basin Segment 5a monitoring (Alternative 1)

Eagle Mine Seepage Alternatives

Collection & Treatment

Groundwater collection in Belden and Rock Creek and treatment at WTP (Alternative 2A)

In-mine precipitation in Bleakhouse mine pool (Alternative 2B)

IRM reaction wall in Belden (Alternative 2C) with groundwater collection in Rock Creek

Waste Rock Alternatives

Source Removal Excavate, transport and dispose of onsite – only accessible acid-generating waste rock (Alternative 3A)

Excavate, transport and dispose of onsite – all waste rock (Alternative 3B)

Excavate, transport and dispose of offsite – all waste rock (Alternative 3C)

Collection & Treatment

Groundwater extraction at WRP-14 in Belden; convey to WTP (included in Alternative 2A)

Rex Flats and OTP Alternatives

Collection & Treatment

Groundwater collection and treatment at new treatment plant (Alternative 4A)

IRM reaction wall(s), in situ treatment (Alternative 4B)

The No Added Action alternative is carried forward in the development of alternatives as Alternative 1 without screening or further evaluation. The following list provides a brief summary of each alternative. A more detailed description of the alternative is provided in Section 6 prior to the detailed analysis of the alternative to the feasibility criteria.

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• Alternative 1 – No Added Action: Alternative 1 prescribes no new remedial actions but recognizes and takes into consideration the engineering actions, rules, regulations, and ICs that have been implemented under the CD/RAP and the CD/SOW.

• Alternative 2A – Groundwater Collection and Treatment, Belden and Rock Creek: Collection of groundwater in Belden and in Rock Creek with treatment at the WTP.

• Alternative 2B – In-mine Precipitation in Bleakhouse Mine Pool: The proposed remediation system involves treating mine water with lime or sodium hydroxide to raise the pH and cause metals to precipitate as insoluble oxyhydroxides. The goal is to reduce the metal concentrations in the mine pool until seepage at Rock Creek no longer causes an exceedance of the WQS. The WTP would function as a backup, treating enough water drawn from Adit 5 to maintain a constant mine pool level of about 8450 ft MSL, and treating water collected in the CTP groundwater extraction trenches. With time, mine pool water would be directly discharged to the river.

• Alternative 2C – IRM Reaction Wall in Belden: The proposed remediation system involves treatment of groundwater through passive in situ treatment in an IRM trench in Belden and achievement of the RAO by intercepting zinc year round. Groundwater would be collected in Rock Creek and treated at the WTP. Tip Top mine water would be treated underground by IRM.

• Alternative 3A – Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite: Acid-generating mine waste piles WP-8, WP-9, WP-10 and the remnants of WP-14 would be excavated and transported by off-road trucks to an onsite repository at the CTP. The truck haul route would utilize the rail easement along the river from Belden to the CTP.

• Alternative 3B – Excavate, Transport and Dispose of All Waste Rock Onsite: All mine waste piles would be excavated and transported by off-road trucks to an onsite repository at the CTP. The truck haul route would utilize the rail easement along the river from Belden to the CTP.

• Alternative 3C – Excavate, Transport and Dispose of All Waste Rock Offsite: All mine waste piles would be excavated and transported to an offsite repository for disposal.

• Alternative 4A – Groundwater Collection and Treatment, OTP/Rex Flats: Groundwater seepage from OTP/Rex Flats would be collected in groundwater interceptor trenches along the west bank of the river at the OTP and along the

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south bank of the river at Rex Flats. The collected water would be pumped to a new treatment facility.

• Alternative 4B – IRM Reaction Wall at OTP/Rex Flats: The proposed remediation system involves constructing two IRM trenches. Groundwater moving to the river from the two primary source areas in OTP/Rex Flats would be treated in situ when passing through the material.

Note that one of the primary metal sources to Segment 5 is background loading from upstream sources in Segment 2. The background loading is offsite and cannot be addressed in this FFS.

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DETAILED ANALYSIS OF ALTERNATIVES 7.0

This section describes the detailed analysis process, as prescribed by the NCP (40 CFR Section 300 et. seq.) and EPA guidance documents.

7.1 DETAILED ANALYSIS PROCESS

The detailed analysis consists of a three-tiered process. The initial tier in the process consists of evaluating each alternative with respect to two threshold criteria: 1) overall protectiveness of human health and the environment and 2) compliance with ARARs. Because each of the candidate alternatives, except the No Added Action alternative, is designed to address the RAO, the first-tier criteria are designed to evaluate the extent to which the RAO is addressed together with the adequacy, safety, and permanence of the methods prescribed under each alternative.

The second tier of the detailed analysis consists of evaluating each alternative with respect to five balancing criteria: long-term effectiveness; short-term effectiveness; reduction of toxicity, mobility, or volume through treatment; implementability; and, cost.

In the third tier, candidate alternatives are evaluated against the modifying criteria of State Acceptance and Public Acceptance. The evaluation of State and Public Acceptance is generally presented in the ROD and can only be completed after the public and State agencies have commented on this FFS and the proposed plan. However, this step is initiated in the FFS by evaluating the alternatives based on what is currently known regarding public and State concerns or support for proposed remedial actions.

The following subsections provide additional background information on the evaluation criteria used in the detailed analysis.

7.1.1 Threshold Criteria

The threshold criteria are so called because they must be satisfied for an alternative to be carried forward in the remedy selection process. The two threshold criteria consist of overall protection of human health and the environment and compliance with ARARs. If both threshold criteria are not satisfied, an individual alternative cannot be considered for selection as the Site remedy with one exception. This exception consists of provisions contained in the NCP for waiving compliance with ARARs under certain site-specific circumstances that would prevent the ARARs from being achieved (40 CFR Part 300.430(f)(1)(ii)(C)).

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7.1.1.1 Overall Protection of Human Health and the Environment

Overall protection of human health and the environment criterion is the final and determining assessment of an alternative’s ability to satisfy the protectiveness requirement. To be deemed protective, an alternative must meet the RAOs, reduce risks to acceptable levels, meet ARARs, and generally satisfy the balancing criteria.

7.1.1.2 Compliance with ARARs

Compliance with ARARs is a judgment based on an alternative’s ability to satisfy a comprehensive list of applicable or relevant and appropriate State and Federal statutory and regulatory requirements. To satisfy this criterion, the actions prescribed under an individual alternative must be capable of meeting applicable or relevant and appropriate chemical-specific, location-specific, and action-specific ARARs, as presented in Section 5.1. In addition to considering the ARARs, the detailed analysis of alternatives may take into consideration TBCs.

The potential chemical-specific, location-specific, and action-specific ARARs and TBCs identified for the Site are presented in Table 19, Table 20, and Table 21, respectively. ARARs and TBCs, identified in these tables, set the stage for evaluating the alternatives for compliance. The actual determination as to which requirements are applicable or relevant and appropriate will be made by EPA in cooperation with the State as part of the remedy selection process.

7.1.2 Primary Balancing Criteria

This subsection describes the primary balancing criteria required for use in the detailed analysis of alternatives. These criteria consist of the following:

• Long-term effectiveness and permanence

• Short-term effectiveness

• Reduction of toxicity, mobility, or volume through treatment

• Implementability

• Cost.

Each of these criteria is briefly described in the following paragraphs.

7.1.2.1 Long-Term Effectiveness and Permanence

The evaluation of long-term effectiveness is a judgment about the level of protection afforded by an alternative after completion of the proposed remedial actions. This judgment includes an assessment of the anticipated effectiveness of the remedy in controlling potential residual risks due to untreated materials or treatment residuals

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remaining on site after completion of the remedial actions. In addition, this assessment includes a judgment regarding the potential for realizing long-term improvements in environmental quality resulting from the alternative. Factors considered under the long-term effectiveness evaluation include the following:

• The magnitude of residual risks upon completion of the remedy, such as the volume, toxicity, mobility, and potential for bioaccumulation of COCs remaining on site

• The expected adequacy and reliability of engineering controls performed under the alternative, including the suitability and continued effectiveness of controls used to manage the residual risks after the RAO has been met

• The potential need for future review of an alternative’s effectiveness.

7.1.2.2 Short-Term Effectiveness

The short-term effectiveness criterion addresses the potential impacts an alternative might have on human health or the environment during the construction or implementation phase, up to the time the RAO is achieved. The following factors are considered in the short-term effectiveness assessment:

• The level of risk prevention afforded communities during remedial actions

• Protections afforded workers engaged in the remedial activities

• The potential impacts on the environment during construction or implementation and the reliability of mitigation measures for preventing or reducing these potential impacts

• The time required to implement the proposed remedial measures and achieve the RAO.

7.1.2.3 Reduction of Toxicity, Mobility, or Volume

The NCP states a preference for remedies that reduce toxicity, mobility, or volume (TMV) of hazardous constituents through treatment. This criterion addresses the extent to which the proposed remedy relies on treatment to address the RAO. Factors used in deciding if an alternative meets the statutory preference for a treatment-based remedy include the following:

• The extent to which COCs are destroyed through treatment

• The reduction in total mass of COCs

• The irreversibility of reductions in COC mobility

• The reduction in total volume of impacted materials

• The type and quantity of treatment residuals.

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In applying this criterion, it is emphasized that metals are elements that cannot be destroyed by treatment. EPA has modified the applicability of this criterion at mining-related sites through OSWER Directive No. 9355.0-26 entitled, Advancing the Use of Treatment Technologies for Superfund Remedies (EPA 1989). Among other things, this directive states that engineering controls, such as containment, are generally more appropriate than treatment technologies at large sites characterized by high-volume, low-toxicity mining and milling wastes. The concepts contained in this directive will be applied as modifying factors in the assessment of alternatives under this criterion.

7.1.2.4 Implementability

The implementability criterion is a measure of the technical and administrative feasibilities of an individual alternative. Under technical feasibility, alternatives are evaluated with respect to the following subcriteria:

• The site-specific constructability and operability of the proposed remedies

• The reliability of the technology and potential for technical problems to delay or prevent achieving the RAO

• The ease of undertaking additional actions aimed at augmenting the initial remedy

• The ability to monitor the effectiveness of the remedy.

The following factors are considered in evaluating the alternatives with respect to the administrative subcriteria:

• The ability to obtain approvals from other agencies

• Anticipated problems in coordinating with state and local agencies and private property owners

• The availability of necessary equipment and skilled personnel to construct and operate facilities or implement remedial actions

• The adequacy of on-site or off-site treatment, storage, and disposal services

• The general availability of technologies prescribed by an alternative, level of development of innovative technologies, and the need for treatability or pilot testing to demonstrate the appropriateness of a proposed technology.

7.1.2.5 Cost

Evaluation of O&M costs for each alternative is performed under the cost criterion. During the detailed analysis, the NCP requires that capital and O&M cost estimates be assembled for each alternative with an accuracy range of at least +50 to –30 percent. A present worth analysis discounting all costs to a common base year is performed. The

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present worth analysis is intended to facilitate a comparison of alternatives based on a single cost number, even when costs may be expended over different time periods.

In accordance with EPA guidance, the cost criterion is comprised of the following cost analyses:

• Direct capital costs, including cost for construction; equipment, labor, and materials; site development and building; and disposal facility

• Indirect capital costs, including cost for engineering, construction oversight, start up and shakedown, and contingency allowances

• Annual O&M costs, including costs for post-construction labor, maintenance, administration, long-term monitoring, equipment replacement, and periodic reviews.

7.1.3 Modifying Criteria

Modifying criteria include State acceptance and community acceptance. State acceptance is a judgment as to the level of State support, reservations, or opposition to proposed remedial actions. Community acceptance addresses possible citizen concerns expressed during the public comment period. In accordance with EPA (1988a) guidance, the final assessment of State and public acceptance is presented in the ROD after the State and public have commented on the completed FFS and proposed plan.

7.2 DETAILED ANALYSIS OF ALTERNATIVE 1: NO ADDED ACTION

Alternative 1 prescribes no new remedial actions but recognizes and takes into consideration the engineering actions, rules, regulations, and ICs that have been implemented under the CD/RAP and the CD/SOW.

Descriptions of existing remedial actions are presented in Section 1.2. The major components of Alternative 1 that would be operated and/or maintained include:

• Surface runon and runoff ditches at Gilman, WP-8, OTP, and the CTP

• MDD

• Liberty well diversion

• CTP cap

• CTP groundwater extraction trenches

• UGDT

• Rock Creek Siphon

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• Mine seepage collection system and pipeline

• WTP and surge ponds.

The ongoing groundwater and surface water monitoring program would continue in the future, as modified by development of the property, if any. The specifics of the monitoring program will be documented in a future Compliance Monitoring Plan.

7.2.1 Alternative 1: Threshold Criteria Evaluation

Evaluation of the No Added Action alternative with respect to the threshold criteria is presented in this section.

7.2.1.1 Overall Protectiveness of Human Health and the Environment

While human health risks are not the focus of this FFS, human health concerns are considered to be low because there are no residents and the few receptors that are present (workers, trespassers, recreational users) have low exposure frequencies. Alternative 1 is generally protective of human health because the ICs (land use controls) in place are designed to limit human exposure to metal COCs. However, the efficacy of some of these ICs (e.g., trespassing limits) is dependent on private landowners and poor implementation diminishes their effectiveness and protectiveness. Alternative 1 does nothing to reduce future reliance on ICs.

Because periodic exceedances of the WQS will continue under some spring runoff conditions in Segment 5a, Alternative 1 is not considered protective of the environment. The RAO would not be consistently met under this alternative because the No Added Action alternative is not capable of achieving the zinc load reduction necessary to meet WQS.

7.2.1.2 Compliance with ARARs

Alternative 1 will not meet the chemical-specific ARAR for surface water as periodic exceedances of the WQS will continue under some spring runoff conditions. This alternative meets the action-specific and location-specific ARARs and TBCs.

7.2.2 Alternative 1: Primary Balancing Criteria Evaluation

Evaluation of the No Added Action alternative with respect to the five primary balancing criteria is presented in this section.

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7.2.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

Because periodic exceedances of the WQS will continue under some spring runoff conditions, Alternative 1 provides no reduction in the magnitude of residual risk.

Adequacy and Reliability of Controls

The controls used for the O&M of the existing remedy are adequate and reliable for those remedies implemented.

7.2.2.2 Short-Term Effectiveness

Worker Protection

Potential risks to workers under Alternative 1 are limited to possible increased exposure to metal COCs associated with monitoring activities. These potential risks are readily mitigated through worker health and safety training and appropriate use of personal protective equipment (PPE).

Potential Environmental Impacts

Under Alternative 1, groundwater and surface water from the Belden area will continue to exceed periodically the WQS in Segment 5a.

Time to Achieve RAOs

The RAO will not be met under this alternative.

7.2.2.3 Reduction of TMV through Treatment

Under the current remedy, TMV is reduced through treatment at the WTP. Alternative 1 provides no additional reduction of TMV through treatment.

7.2.2.4 Implementability

Technical Feasibility

The actions proposed under Alternative 1 are implementable.

Administrative Implementability

Alternative 1 has been implemented.

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Availability of Materials and Labor

Materials and labor needed to implement Alternative 1 are readily available.

7.2.2.5 Cost

Estimated costs for Alternative 1 are summarized in Table 23. The only costs associated with Alternative 1 are the annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management. The present worth is calculated using a discount rate of 7 percent and assumes monitoring costs are the same as 2008 over a 30-year period. Detailed O&M and present worth cost estimates for Alternative 1 are presented in Appendix F.

Table 23 Alternative 1 Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

None $ 807,000 $ 10,825,000

7.2.3 Alternative 1: Modifying Criteria

Evaluation of the No Added Action alternative with respect to the modifying criteria is presented in this section.

7.2.3.1 State Acceptance

Alternative 1 is unlikely to meet with State acceptance.

7.2.3.2 Public Acceptance

Public acceptance of Alternative 1 is unlikely.

7.3 DETAILED ANALYSIS OF ALTERNATIVE 2A: GROUNDWATER COLLECTION AND TREATMENT, BELDEN AND ROCK CREEK

Alternative 2A is designed to achieve the RAO by collection of groundwater in Belden and Rock Creek with treatment at the WTP. Alternative 2A consists of a system that collects groundwater at Belden, at the base of Rock Creek, and from the Mill Level of the mine and conveys the water to the WTP.

For the cost estimation purposes a trench is assumed to be the system used for groundwater collection. The new collection trench would be constructed with 700 feet of

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perforated pipe set at the static (fall/winter) groundwater level, some 15 to 18 feet below ground surface (bgs), and designed to intercept the spring pulse of groundwater that occurs each year in Belden. The trench would be constructed parallel or beneath the railroad along a line extending from the base of the Tramway Drainage downstream the full length of the Loading Dock. As a part of trench construction, excavated track ballast, waste rock and gravel will be hauled to the CTP. Excavated trash and debris (rails, ties, pipes, etc.) will be taken to the municipal landfill. Trench backfill above the high groundwater level will consist of crushed limestone and dolomite waste rock from WP-11 in Rock Creek. The trench will be lined with a polyethylene liner on the river side to establish a permeability barrier.

A diagram of the proposed collection trench location is presented in Figure 20. A non-perforated connecting pipeline would extend 1,100 feet downstream from the end of the perforated section to near Rock Creek where it would enter the existing pipeline and gravity drain to the WTP for treatment. Water that collects in the existing Copper Tipple Trench would gravity drain to the new (lower) trench via the historic tunnel (see description of tunnel in Section 4.2.2).

Water that accumulates on the Mill Level of the mine would be pumped periodically to the new collection trench to minimize recharge from this source.

Existing well EDS-3 at the base of Rock Creek would be used to extract 10 gpm of groundwater continuously during March and April. The discharge would be conveyed via the existing pipeline to the WTP for treatment. Power is available at Rock Creek and the well has proven that it is capable of producing 6 to 12 lbs/day zinc (see Section 4.4 Rock Creek).

The proposed gravity collection system is highly dependent on the presence of groundwater and the depth of the collection pipe. However, as the collection system is gravity fed, it would collect water during all seasons. A valve will be incorporated at the discharge end to allow shut-off in May.

Pump tests prove that the yield will change with the seasonal recharge. Combined with EDS-3 in Rock Creek, Alternative 2A is expected to yield 46 to 92 lbs/day zinc, depending on the winter snowpack (see Table 18, Belden and Rock Creek groundwater).

The proposed system was designed to operate off-the-grid. If power becomes available in Belden, either from hydroelectric, solar photovoltaics, or a conventional land-line brought in from Gilman or Rock Creek, the production from the gravity system could be easily supplemented by pumping existing wells or new wells. A price of $150,000 should be added to the other costs if the existing wells are used.

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Eagle River

Tramwa

y Tribu

tary

Fall Creek

Eagle River

Histo

ric T

unne

l

qLegend

Proposed Trenches

Interceptor Trench

Pipeline Extension

Existing Pipe & Trenches

Mine Seep Pipeline

Copper Tipple Trench

0 70 140 210 28035

Feet

Figure 20Proposed Trench Location

(Alternatives 2A and 2C)in Belden

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7.3.1 Alternative 2A: Threshold Criteria Evaluation

Evaluation of Alternative 2A with respect to the threshold criteria is presented in this section.

7.3.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 2A is protective of human health because the ICs, put in place under the previous actions that were designed to limit human exposure to COCs, apply here as well. Alternative 2A involves excavation of railroad ballast and mine waste; Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

Alternative 2A provides protection of the aquatic environment by decreasing the concentrations of COCs in the Eagle River. Alternative 2A is capable of achieving the zinc load reductions in March and April necessary to meet the RAO.

7.3.1.2 Compliance with ARARs

Except for possible sporadic exceedances of the chemical-specific surface water ARAR for the river, Alternative 2A meets the chemical-, action-, and location-specific ARARs.

Chemical-Specific ARARs

The surface water actions prescribed under Alternative 2A are expected to result in achieving the chemical-specific ARARs (WQS). However, the loading analysis discussed in Section 2.1.2 and shown in Table 4 indicates this alternative is probably not capable of achieving the metal loading reductions needed to meet the ARAR under all conditions because it does not remove the upstream background load.

Action-Specific ARARs

Alternative 2A is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 2A is expected to meet the location-specific ARARs.

TBCs

Alternative 2A is expected to meet the TBC guidance.

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7.3.2 Alternative 2A: Primary Balancing Criteria Evaluation

Evaluation of Alternative 2A with respect to the five primary balancing criteria is presented in this section.

7.3.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

The alternative does not address the source of metals (e. g. residual mineralization in the mine and in waste materials), thus there is residual risk. Loading from upstream sources is not controlled under any of the Alternatives.

Adequacy and Reliability of Controls

The response actions will result in an immediate reduction in metal loading sources through physical removal and treatment.

Surface water monitoring would need to continue, and changes in water quality as a result of the remedial actions will be readily detectable through conventional surface water monitoring techniques.

Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Effective trespass restrictions may be necessary to protect the selected remedy. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

7.3.2.2 Short-Term Effectiveness

Community Protection

Short-term community protection has not been addressed because the remedial activities will be conducted in areas that are off limits to the general public. Non-workers will be excluded from active remediation sites.

Fugitive dust emissions during remedy implementation can be readily mitigated, if necessary, through conventional dust control measures, such as wetting or applying dust suppressants to haul roads or material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation areas and by implementing effective dust control.

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Worker Protection

Worker protection issues under Alternative 2A include increased traffic safety risks, heavy equipment operations, physical hazards associated with rock falls and avalanches, dust inhalation, and ingestion of metals.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. In addition site hazards, such as rock falls and avalanches in the canyon, increase the probability of accidents. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

Potential Environmental Impacts

Some construction activities may result in impacted sediment transport to the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and best management practices (BMPs) (e.g., silt fencing) will minimize sediment transport.

Time to Achieve RAOs

Post-construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition. The time required to achieve the RAO under Alternative 2A is anticipated to be one to two years.

7.3.2.3 Reduction of TMV through Treatment

Collection of groundwater and treatment at the WTP meets the CERCLA preference for alternatives that reduce TMV through treatment.

7.3.2.4 Implementability

Technical Feasibility

Alternative 2A is technically implementable. If the remedy under Alternative 2A fails to meet the RAO, additional remedial actions could be readily implemented.

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Implementability is limited by the lack of electricity. Canyon topography, buildings, and the railroad constrain the design and constructability of a subsurface collection trench. Rock falls in the canyon may impede construction and maintenance. Shallow bedrock presents an obstacle to achieving the design depth required for some of the pipeline segments and blasting may be needed to remove bedrock, adding to the cost. Alternatively, a pump station and/or wells supplied with electric power may be employed to pump collected water to the main pipeline if power can be made available. The proposed gravity system cannot be easily modified to provide for adjustments in flow. The historic tunnel may not be intact at its projected intersection with the new collection trench, necessitating tunneling under the concrete Loading Dock and rehabilitation work. Freezing lines are a concern with a pump system but less so with a pipeline that is buried and self-draining. Sub-zero temperatures will cause problems with any water handling system that is not adequately protected.

Alternative 2A is expected to be technically feasible from an O&M perspective because the passive system is designed to operate with minimal supervision during the operational months of March and April. An active pump system operating in cold weather will require more supervision.

Administrative Feasibility

Successful implementation of Alternative 2A will require coordination among the railroad, the landowner, and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action. More effective trespass restrictions may be necessary to protect the selected remedy.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available.

7.3.2.5 Cost

Estimated costs for Alternative 2A are summarized in Table 24. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 2A are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included. These costs do not include a power supply in Belden.

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Table 24 Alternative 2A Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 385,000 $ 822,000 $ 11,390,000

7.3.3 Alternative 2A: Modifying Criteria

Evaluation of Alternative 2A with respect to the modifying criteria is presented in this section.

7.3.3.1 State Acceptance

CDPHE has expressed support for this remedy.

7.3.3.2 Public Acceptance

The general public is likely to support Alternative 2A.

7.4 DETAILED ANALYSIS OF ALTERNATIVE 2B – IN MINE PRECIPITATION IN BLEAKHOUSE MINE POOL

The proposed remediation system involves treating the water in the mine pool with lime or sodium hydroxide to raise the pH and cause metals to precipitate as insoluble oxyhydroxides. The WTP would be operated as a secondary treatment train, periodically adjusted to compensate for an influent from the mine with increasing pH and decreasing total dissolved solids. The long-term goal of the proposed treatment system is to improve the water chemistry of the upper portion of the mine pool to the point where 1) Adit 5 water can be discharged with little or no treatment, and 2) reduce zinc loading to Rock Creek.

The final design of the full-scale in-mine treatment system will be dependent on the results of laboratory and pilot-scale testing; however, the full-scale built-out system would likely include the following.

• Use the existing sump at the base of Rock Creek as a collection point for water from Adit Nos.5 and 6, WP-8 runoff, Seep 7, and Tip Top mine.

• Construction of additional pumping and piping, as necessary, to deliver this sump water to a new slurrying/solution system in Gilman.

• Delivery of lime or sodium hydroxide reagent from a new slurrying/solution system in Gilman into the Bleakhouse mine pool.

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The WTP would function as a backup, treating enough water drawn from Adit 5 to maintain a constant mine pool level of about 8450 ft MSL and treating water collected in the CTP groundwater extraction trenches. With time, mine pool water would be directly discharged to the river and the WTP would be down-sized.

There is a reasonable probability of lowering treatment costs over the long term using this system. Seepage from the Bleakhouse mine pool makes up some of the recharge and the zinc concentration of Rock Creek groundwater is expected to drop slightly from its current level, eventually lowering the zinc load contributed to the Lower Reach of Segment 5a by an estimated 2 lbs/day (see Section 4.4). Data collected thus far do not suggest that chemistry changes in the Bleakhouse pool will affect the water quality in Belden or in the Upper Reach.

7.4.1 Alternative 2B: Threshold Criteria Evaluation

Evaluation of Alternative 2B with respect to the threshold criteria is presented in this section.

7.4.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 2B is protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Alternative 2B does not include any additional land use controls or zoning restrictions beyond that provided under previous actions, and the alternative does nothing to reduce future reliance on ICs that are already in place.

Alternative 2B provides protection of the aquatic environment by decreasing the concentrations of COCs in Segment 5a but is not expected to be capable of achieving the zinc load reduction needed to meet the RAO.

7.4.1.2 Compliance with ARARs

Alternative 2B meets the action- and location-specific ARARs.

Chemical-Specific ARARs

This alternative is probably not capable of achieving the metal loading reductions needed to meet the ARAR under all conditions, especially in the short term.

Action-Specific ARARs

Alternative 2B is expected to meet the action-specific ARARs.

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Location-Specific ARARs

Alternative 2B is expected to meet the location-specific ARARs.

TBCs

Alternative 2B is expected to meet the TBC guidance.

7.4.2 Alternative 2B: Primary Balancing Criteria Evaluation

Evaluation of Alternative 2B with respect to the five primary balancing criteria is presented in this section.

7.4.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

The alternative does not address the source of metals thus there is residual risk. After implementation, exceedances of the WQS would probably continue to occur. Therefore, the RAO would not be fully met under Alternative 2B.

In-mine treatment is not expected to decrease the zinc concentration in Belden groundwater because a hydraulic link between the main mine pool and Belden has not been established.

Loading from upstream sources is not controlled under any of the Alternatives.

Adequacy and Reliability of Controls

Controls for in situ treatment are not as reliable as controls for conventional engineered remedies.

Surface water monitoring would need to continue and changes in water quality as a result of the remedial actions will be readily detectable through conventional surface water monitoring techniques.

Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Effective trespass restrictions may be necessary to protect the selected remedy.

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7.4.2.2 Short-Term Effectiveness

Community Protection

The transportation of more treatment chemicals to the mine presents a slight increase in risks to the community. Other than that, short-term community protection has not been addressed because the remedial activities will be conducted in areas that are off limits to the general public.

Worker Protection

Fewer worker protection issues are associated with Alternative 2B than with the other alternatives. These include increased traffic safety risks, heavy equipment operations, physical hazards associated with working on steep slopes, dust inhalation, and ingestion of metals.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. In addition site hazards, such as rock falls and avalanches in the canyon, increase the probability of accidents. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

Potential Environmental Impacts

There are few if any negative environmental impacts that would be caused by implementation of Alternative 2B.

Time to Achieve RAOs

Post-construction monitoring of Rock Creek groundwater will be used to determine if the remedy is affecting zinc concentrations. Alternative 2B is not expected to be capable of achieving the zinc load reduction needed to meet the RAO.

7.4.2.3 Reduction of TMV through Treatment

In situ treatment meets the CERCLA preference for alternatives that reduce TMV through treatment.

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7.4.2.4 Implementability

Technical Feasibility

Alternative 2B is technically implementable; however, the effectiveness of in-mine precipitation is unknown in this environment. Incomplete mixing of the mine water and the reagent is very likely and precipitated solids may eventually clog the MDD flow path through the Adit 5 bulkhead. Access to the mine pool is limited, thus initial implementation and the ability to re-access the area for remedy enhancements may be hampered.

Administrative Feasibility

Successful implementation of Alternative 2B will require coordination between the current landowner and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action. Protection of the remedy from vandalism has proven to be a problem and more effective restrictions may be necessary to protect facilities that are installed in Gilman. Other than that, Alternative 2B is more administratively feasible than most alternatives due to a lack of above-ground facilities.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available.

7.4.2.5 Cost

Estimated costs for Alternative 2B are summarized in Table 25. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 2B are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included. Water treatment costs are significantly reduced under this alternative resulting in the lowest net present worth of any of the alternatives except Alternative 1.

Table 25 Alternative 2B Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 404,000 $ 312,000 $ 5,080,000

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7.4.3 Alternative 2B: Modifying Criteria

Evaluation of Alternative 2B with respect to the modifying criteria is presented in this section.

7.4.3.1 State Acceptance

State acceptance is unknown.

7.4.3.2 Public Acceptance

Public acceptance is unknown.

7.5 DETAILED ANALYSIS OF ALTERNATIVE 2C – IRM REACTION WALL IN BELDEN

The proposed remediation system involves passive in situ treatment of groundwater that has been shown to be a primary source of metals loading to Segment 5. Groundwater moving to the river from source areas in Belden would be treated in situ when passing through the iron-rich material (IRM). Alternative 2C is designed to remove up to 130 lbs/day zinc using an IRM wall to absorb zinc and other metals that would otherwise enter the river at Belden. The 130 lbs/day figure is a design specification for 30 years; the IRM is capable of absorbing more 130 lbs/day over the short term. The existing, electrified pumping well at the base of Rock Creek, EDS-3, would operate to capture and treat Rock Creek groundwater for another 6 to 12 lbs/day for a total of up to 142 lbs/day zinc.

Pilot tests using IRM and Eagle mine water have proven effective at removing metals. The remediation system designed by Adrian Brown (2012) involves constructing a trench to bedrock in Belden containing 4,200 tons (2,900 CY) of IRM, roughly at the location of the proposed interceptor trench shown on Figure 20. Materials excavated from the trench are a source of zinc and other metals and the rail ballast, debris, and waste rock will be hauled to the CTP for separation and disposal. Trash and debris (e.g., rails, ties, pipes, and lumber) will be separated and taken to the municipal landfill or salvaged. Gravels and rock will be dumped at the Temp Cell or other CTP site designated by the landowners. Trench backfill above the IRM will consist of alkaline limestone and dolomite waste rock borrowed from WP-11 in Rock Creek (see Section 4.3 for waste rock description). Tip Top mine water (approx.10 gpm) will be conveyed in a new low-pressure pipe to the upgradient side of the IRM wall and treated in situ. Three existing wells, BW-5, 6 and 7, and two new wells will be used for monitoring wells on the downgradient (river) side of the wall.

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The IRM wall is designed to have a 30-year life. After its lifetime, the “spent” wall will be excavated and replaced with fresh IRM.

If successfully implemented, the IRM wall would relieve the WTP of 5.8 million gallons of Tip Top mine water each year. The pipeline from the Belden to Rock Creek carrying Tip Top water would be abandoned, eliminating the possibility of a mine water release in that section. This buried in situ place-and-forget system does not require a power supply and is burdened by essentially no maintenance costs; however, it is inherently not receptive to modifications after installation. Some of the existing 10 monitoring wells in Belden could be converted to pumping wells for $150,000 to intercept additional groundwater if the RAO is not met. Permeability barriers could be installed to limit the amount of groundwater passing around the ends of the IRM wall.

7.5.1 Alternative 2C: Threshold Criteria Evaluation

Evaluation of Alternative 2C with respect to the threshold criteria is presented in this section.

7.5.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 2C is protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Alternative 2C does not include any additional land use controls or zoning restrictions beyond that provided under previous actions, and the alternative does nothing to reduce future reliance on ICs that are already in place.

Alternative 2C provides protection of the aquatic environment by decreasing the concentrations of COCs in the Eagle River. Alternative 2C is expected to be capable of achieving a zinc load reduction necessary to meet the RAO for 30 years.

7.5.1.2 Compliance with ARARs

Except for possible sporadic exceedances of chemical-specific surface water ARARs for the river, Alternative 2C meets the chemical-, action-, and location-specific ARARs.

Chemical-Specific ARARs

This alternative is capable of achieving the metal loading reductions needed to meet the ARAR. However, the loading analysis discussed in Section 3.2 and shown in Table 4 indicates this alternative is probably not capable of achieving the metal loading reductions needed to meet the ARAR under all conditions because it does not remove the upstream background load.

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Action-Specific ARARs

Alternative 2C is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 2C is expected to meet the location-specific ARARs.

TBCs

Alternative 2C is expected to meet the TBC guidance.

7.5.2 Alternative 2C: Primary Balancing Criteria Evaluation

Evaluation of Alternative 2C with respect to the five primary balancing criteria is presented in this section.

7.5.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

While some source material is removed under the alternative, not all is addressed, thus there is residual risk. Loading from upstream sources is not controlled under any of the Alternatives.

Adequacy and Reliability of Controls

The response actions will result in an immediate reduction in metal loading sources through physical removal and treatment. However, the load reduction may not be completely adequate to consistently achieve the RAO as the upstream background load will not be removed.

Surface water monitoring would need to continue and changes in water quality as a result of the remedial actions will be readily detectable through conventional surface water monitoring techniques. Groundwater monitoring using existing wells would provide performance evaluation data.

Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Trespass restrictions would not be necessary to protect the remedy. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

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7.5.2.2 Short-Term Effectiveness

Community Protection

The transportation of IRM to the site presents risks to the community. Other than that, short-term community protection has not been addressed because the remedial activities will be conducted in areas that are off limits to the general public.

Fugitive dust emissions can be readily mitigated through implementation of conventional dust control measures, such as wetting or applying dust suppressants to haul roads or material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation sites and by implementing effective dust control.

Worker Protection

Worker protection issues associated with Alternative 2C include increased traffic safety risks, heavy equipment operations, dust inhalation, and ingestion of metals.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. In addition site hazards, such as rock falls and avalanches in the canyon, increase the probability of accidents. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

Potential Environmental Impacts

Some construction activities may result in impacted sediment transport to the Eagle River with possible damage to sensitive aquatic ecosystems. As this system requires replacement after several decades, these impacts could reoccur. Proper use of storm water controls and BMPs (e.g., silt fencing) will minimize sediment transport.

Time to Achieve RAOs

Without testing the buried in-place system, there is no way of predicting the decrease in metal loading in Belden; therefore, the time needed to achieve the RAO is unknown. Based on testing of IRM at this and other sites, the time to achieve the RAO is expected

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to be one to two years. Post-construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition.

7.5.2.3 Reduction of TMV through Treatment

In situ treatment meets the CERCLA preference for alternatives that reduce TMV through treatment.

7.5.2.4 Implementability

Technical Feasibility

Alternative 2C is technically implementable. Large boulders in the subsurface are expected to make trench excavation difficult. The IRM trench may not reach bedrock along its entire length, thus allowing the potential for underflow of contaminated groundwater. Debris excavated from the trench will have to be separated from the gravel and disposed of at a landfill.

Administrative Feasibility

Successful implementation of Alternative 2C will require coordination among the railroad, the current landowner and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action. Protection of the remedy from vandalism has proven to be a problem in Belden. In this regard, Alternative 2C is more attractive than the other alternatives due to the use of an underground PRB.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available. IRM is available but delivery times are long. Alternate materials may be considered if availability becomes a problem.

7.5.2.5 Cost

Estimated costs for Alternative 2C are summarized in Table 26. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 2C are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included. The costs assume that the IRM wall has a life expectancy of 30 years.

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Table 26 Alternative 2C Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$635,000 $ 773,000 $ 10,995,000

7.5.3 Alternative 2C: Modifying Criteria

Evaluation of Alternative 2C with respect to the modifying criteria is presented in this section.

7.5.3.1 State Acceptance

State acceptance is expected to be low based on poor performance of IRM at other sites.

7.5.3.2 Public Acceptance

Public acceptance may be high because this alternative is designed to prevent up to 142 lbs/day from entering the river during the spring.

7.6 DETAILED ANALYSIS OF ALTERNATIVE 3A: EXCAVATE, TRANSPORT AND DISPOSE OF ACCESSIBLE AND ACID-GENERATING WASTE ROCK ONSITE

This alternative is focused on the waste rock piles that are accessible and that are potential sources for zinc loading based on the assessment of their acid-generating potential (see Section 4.3). Acid-generating waste piles WP-8, WP-9 and WP-10 (Ben Butler and Tip Top mines), and the remnants of WP-14 would be excavated and transported by off-road trucks and conveyed to an onsite repository at the CTP. The truck haul route would utilize the rail easement along the river from Belden to the CTP. The removal of WP-9 and WP-10 would require the removal of the concrete block crib wall installed by EPA in 2009. The removal of WP-9 and WP-10 would also require federal funding because the piles resulted from “orphan” mining operations.

WP-13 at the Rocky Point tunnel on the cliff below Gilman contains some of the lowest metal levels of any of the waste rock piles but is potentially acid generating. Removal of this relatively inaccessible pile is considered to be impractical and not justified in terms of the added risk to workers and the trace amount of metal load that could be removed from the system. The removal of WP-13 is not considered under this alternative.

To raise the soil pH, the excavated footprint of the waste rock piles would be limed with ground calcium carbonate, sugar beet precipitated calcium carbonate, or their equivalent

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(EPA 2007). No other soil amendments are prescribed for WP-9 and WP-10 since the areas will not be revegetated. The 4-acre footprint of WP-8 would receive lime, soil amendments, and seed for revegetation.

The source of some of the metals that impact Segment 5a would be eliminated by relocation to a repository. The removal would eliminate a potential source of COC exposure to future residents of Gilman, if any. The removal will eliminate most of the O&M currently committed to WP-8. As a stand-alone option, the removal of the waste rock is expected to result in up to 8 lbs/day reduction (see Section 4.3 and Table 18) in zinc loading to the Lower Reach of Segment 5a, primarily due to the relocation of WP-8 in Rock Creek. The net impact of removing the other smaller piles (see Section 4.3 and Table 18) is small and is ignored in this estimate.

The existing runon, runoff and sediment retention facilities would remain in place, at least over the short term. If source removal fails to meet expectations, the runoff collection facilities and/or vegetation actions could be expanded. The small cost of these additional items is covered under the contingency

7.6.1 Alternative 3A: Threshold Criteria Evaluation

Evaluation of Alternative 3A with respect to the threshold criteria is presented in this section.

7.6.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 3A is generally protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Alternative 3A marginally enhances human health protection in the former Town of Gilman by the removal of WP-8. Alternative 3A does not include any additional land use controls or zoning restrictions beyond that provided under previous actions, and the alternative does nothing to reduce future reliance on ICs that are already in place.

Because of the continued risks to aquatic biota in Segment 5a, Alternative 3A is not considered protective of the environment. The RAO would not be consistently met because Alternative 3A is not capable of achieving the zinc load reduction necessary to meet WQS.

7.6.1.2 Compliance with ARARs

Evaluation of Alternative 3A with respect to the ARARs is presented in this section.

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Chemical-Specific ARARs

Waste rock removal prescribed under Alternative 3A will not achieve the chemical-specific ARARs during March and April.

Action-Specific ARARs

Alternative 3A is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 3A is expected to meet most location-specific ARARs. Removal of WP-14 will likely destabilize and collapse the Copper Tipple Loading Building which may be classified as an historic structure. Historic features and cultural resources will be identified through consultation with the State Historic Preservation Office (SHPO).

TBCs

Alternative 3A is expected to meet the TBC guidance.

7.6.1.3 Alternative 3A: Primary Balancing Criteria Evaluation

Evaluation of Alternative 3A with respect to the five primary balancing criteria is presented in this section.

7.6.1.4 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

Given the steep terrain, it is reasonable to expect that some acid-generating waste rock will remain on the hillsides due to lack of access. The physical removal will result in elimination of a significant portion of the source but will not eliminate it altogether; metals will continue to leach from the freshly exposed bedrock and underlying soils for an undetermined period of time, potentially impacting surface runoff and groundwater. The primary residual source is the landslide deposit below WP-8 that contains zinc and other metals leached or washed from the pile.

The source removal provides some reduction in the magnitude of residual risks. The primary risk, metals within the Belden groundwater, is not addressed by this alternative.

Loading from upstream sources is not controlled under any of the Alternatives.

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Adequacy and Reliability of Controls

The response actions will result in a small long-term reduction in metal loading through physical removal. However, the loading studies indicate that this action will not be adequate to consistently achieve the RAO under the flow conditions when the WQS are exceeded.

Only small changes in water quality are expected as a result of this remedial alternative; these changes will likely not be detectable with conventional surface water monitoring techniques.

New or modified ICs designed to protect the waste repository on the CTP cap from human disturbance and prevent future risk to human health will be necessary. This will require coordination with the landowners. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

7.6.1.5 Short-Term Effectiveness

Community Protection

Short-term community protection has not been addressed because the remedial activities will be conducted in areas that are off limits to the general public. Non-workers will be excluded from active remediation sites.

Fugitive dust emissions can be readily mitigated through implementation of conventional dust control measures, such as wetting or applying dust suppressants to haul roads or material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation sites and by implementing effective dust control.

Worker Protection

There are more worker protection issues associated with waste rock removal than with the other alternatives. These include increased traffic safety risks, heavy equipment operations, physical hazards associated with working on steep slopes, dust inhalation, and ingestion of metals. Mine waste excavation and relocation presents an increased risk to workers that may not be justifiable in terms of the protection offered to the environment.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. In addition site hazards, such as rock falls and avalanches in the canyon, increase the probability of accidents. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

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Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

The use of an off-road haul route reduces the risk of traffic accidents, when compared to haulage on Highway 24.

Potential Environmental Impacts

The waste rock removal from steep slopes will result in some impacted sediment transport to Rock Creek and the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and BMPs (e.g., silt fencing) will minimize but not eliminate sediment transport.

Time to Achieve RAOs

Post-construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition. It is not expected that the RAO will be met under any time frame by this alternative.

7.6.1.6 Reduction of TMV through Treatment

Alternative 3A does not meet the CERCLA preference for alternatives that reduce TMV through treatment.

7.6.1.7 Implementability

Technical Feasibility

Alternative 3A is technically implementable. As only waste rock piles that are accessible via backhoes and dump trucks will be addressed under this alternative, Alternative 3A may be viewed as the most feasible alternative for the removal of waste rock piles.

The location of the Copper Tipple Building may make the complete removal of WP-14 infeasible if the building cannot be removed due to historic significance. Historic features and cultural resources will be identified through consultation with the SHPO.

Administrative Feasibility

Successful implementation of Alternative 3A will require coordination among EPA, CDPHE, the railroad, the current landowner, and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this

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alternative. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available.

7.6.1.8 Cost

Estimated costs for Alternative 3A are summarized in Table 27. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 3A are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included. Note that the O&M cost of the current remedy has been reduced because this alternative eliminates the need for runon and runoff controls at WP-8.

Table 27 Alternative 3A Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 3,765,000 $ 807,000 $ 14,590,000

7.6.2 Alternative 3A: Modifying Criteria

Evaluation of Alternative 3A with respect to the modifying criteria is presented in this section.

7.6.2.1 State Acceptance

State support is unknown.

7.6.2.2 Public Acceptance

Public acceptance of this alternative is likely.

7.7 DETAILED ANALYSIS OF ALTERNATIVE 3B: EXCAVATE, TRANSPORT AND DISPOSE OF ALL WASTE ROCK ONSITE

This alternative will remove waste rock piles regardless of their acid-generating potential and will address piles that are not readily accessible. All mine waste piles (see Figure 16) would be excavated and transported by off-road trucks and conveyed to an onsite

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repository at the CTP. The truck haul route would utilize the rail easement along the river from Belden to the CTP.

Conventional open cut excavation with track excavators, wheel loaders, and scrapers is applicable to WP-7, WP-8, WP-9, WP-10, the top of WP-11, and a portion of WP-14. Removal of WP-1 through WP-6, the lower portion of WP-11, the top of WP-14, Adit 7, and Crossbeam piles on steep slopes is expected to require aerial trams and draglines. The removal of WP-9 and WP-10 would require the removal of the concrete block crib wall installed by EPA in 2009. The removal of WP-9 and WP-10 would also require federal funding because the piles resulted from “orphan” mining operations.

WP-13 at the Rocky Point tunnel on the cliff below Gilman is not accessible with conventional equipment. Removal of this relatively inaccessible waste rock pile is considered to be impractical and not justified in terms of the added risk to workers and the trace amount of metal load that could be removed from the system.

To raise the soil pH, the excavated footprint of the acid-generating waste rock piles would be limed with ground calcium carbonate, sugar beet precipitated calcium carbonate, or their equivalent (EPA 2007). No other soil amendments are prescribed since the areas will not be revegetated. The 4-acre footprint of WP-8 would receive lime, soil amendments, and seed for revegetation.

The source of some of the metals that impact Segment 5a would be eliminated by relocation and capping. The removal would eliminate a potential source of COC exposure to future residents of Gilman, if any. The removal will eliminate the O&M currently committed to WP-8. As a stand-alone option, the removal of the waste rock is expected to result in a decrease of up to 8 lbs/day in zinc loading to Segment 5a (see Section 4.3 and Table 18). Alternative 3B is essentially an expansion of 3A, adding the removal of waste rock piles that possess little or no potential to generate acid. This modification adds cost but with no concomitant reduction in metal loading.

The existing runon, runoff and sediment retention facilities would remain in place, at least over the short term. If source removal fails to meet expectations, the runoff collection facilities and/or vegetation actions could be expanded. The small cost of these additional items is covered under the contingency.

7.7.1 Alternative 3B: Threshold Criteria Evaluation

Evaluation of Alternative 3B with respect to the threshold criteria is presented in this section.

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7.7.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 3B is generally protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Alternative 3B does not include any additional land use controls or zoning restrictions beyond that provided under previous actions, and the alternative does nothing to reduce future reliance on ICs that are already in place. Alternative 3B reduces future reliance on ICs in the former Town of Gilman by the removal of waste rock piles.

Because of the continued risks to aquatic biota in Segment 5a, Alternative 3B is not considered protective of the environment. The RAO would not be consistently met because Alternative 3A is not capable of achieving the zinc load reduction necessary to meet WQS.

7.7.1.2 Compliance with ARARs

Evaluation of Alternative 3B with respect to the ARARs is presented in this section.

Chemical-Specific ARARs

The loading analysis discussed in Section 4.3.1 indicates that the waste rock removal prescribed under Alternative 3B will not achieve the chemical-specific ARARs (WQS) in the spring.

Action-Specific ARARs

Alternative 3B is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 3B is expected to meet the location-specific ARARs. Removal of WP-14 will likely destabilize and collapse the Copper Tipple Loading Building which may be classified as an historic structure. Historic features and cultural resources will be identified through consultation with the SHPO.

TBCs

Alternative 3B is expected to meet the TBC guidance.

7.7.2 Alternative 3B: Primary Balancing Criteria Evaluation

Evaluation of Alternative 3B with respect to the five primary balancing criteria is presented in this section.

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7.7.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

While more of the waste rock piles are removed under this alternative, the magnitude of residual risk is not expected to be reduced any further than that described under Alternative 3A.

Given the steep terrain, it is reasonable to expect that some acid-generating waste rock will remain on the hillsides due to lack of access. The physical removal of the mine waste will not eliminate the source; metals will continue to leach from the freshly exposed bedrock and underlying soils for an undetermined period of time, impacting surface runoff and groundwater.

As the waste rock piles cannot be tied to the magnitude or duration of the increased metals within the Belden groundwater, this alternative provides no reduction in the magnitude or residual risk.

Loading from upstream sources is not controlled under any of the Alternatives.

Adequacy and Reliability of Controls

The response actions will result in a small long-term reduction in metal loading through physical removal. However, the loading studies indicate that this action will not be adequate to consistently achieve the RAO under all flow conditions.

Only small changes in water quality are expected as a result of the remedial actions; these changes will likely not be detectable with conventional surface water monitoring techniques.

New or improved ICs designed to protect the repository cap on the CTP from human disturbance and prevent future risk to human health will be necessary. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

7.7.2.2 Short-Term Effectiveness

Community Protection

Short-term community protection has not been addressed because the remedial activities will be conducted in areas that are off limits to the general public.

Fugitive dust emissions can be readily mitigated through implementation of conventional dust control measures, such as wetting or applying dust suppressants to haul roads or

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material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation sites and by implementing effective dust control.

Worker Protection

There are more worker protection issues associated with waste rock removal than with the other alternatives. These include increased traffic safety risks, heavy equipment operations, physical hazards associated with working on steep slopes, dust inhalation, and ingestion of metals.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. In addition site hazards, such as rock falls and avalanches in the canyon, increase the probability of accidents. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Mine waste excavation and relocation presents an increased risk to workers that may not be justifiable in terms of the protection offered to the environment.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

The use of an off-road haul route reduces the risk of traffic accidents, when compared to haulage on Highway 24.

Potential Environmental Impacts

The waste rock removal from steep slopes will result in some impacted sediment transport to Rock Creek and the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and BMPs (e.g., silt fencing) will minimize but not eliminate sediment transport. Alternative 3B maintains the highest potential for impacts because more waste rock is moved and due to the steep terrain the chances of rock falls and avalanches caused by remedial activities become more likely and the ability to control less likely.

Time to Achieve RAOs

Post construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition. It is not expected that the RAO will be met under any time frame by this alternative.

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7.7.2.3 Reduction of TMV through Treatment

Alternative 3B does not meet the CERCLA preference for alternatives that reduce TMV through treatment.

7.7.2.4 Implementability

Technical Feasibility

Alternative 3B is technically implementable; however, the slopes, potential rock slides, and the required use of aerial trams and draglines make this alternative potentially less feasible to be fully implementable because they involve removal of all waste rock piles.

The location of the Copper Tipple Building may make the complete removal of WP-14 infeasible if the building cannot be removed due to historic significance.

Administrative Feasibility

Successful implementation of Alternative 3B will require coordination among EPA, CDPHE, the railroad, the current landowner, and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available.

7.7.2.5 Cost

Estimated costs for Alternative 3B are summarized in Table 28. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 3B are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included.

Table 28 Alternative 3B Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 5,058,000 $ 807,000 $ 15,717,000

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7.7.3 Alternative 3B: Modifying Criteria

Evaluation of Alternative 3B with respect to the modifying criteria is presented in this section.

7.7.3.1 State Acceptance

State acceptance is unknown.

7.7.3.2 Public Acceptance

Public acceptance is likely.

7.8 DETAILED ANALYSIS OF ALTERNATIVE 3C: EXCAVATE, TRANSPORT AND DISPOSE OF ALL WASTE ROCK OFFSITE

This alternative is the same as Alternative 3B, except that all waste will be disposed of offsite. All waste rock piles would be excavated and transported to an offsite Subtitle D landfill capable of accepting the waste rock materials. The truck haul route would utilize Highway 24 and Interstate 70 with a staging area in Gilman.

Alternative 3C is similar to on-site disposal in that metal sources in the waste rock would be relocated and capped. The removal would eliminate a potential source of lead, cadmium, zinc and arsenic exposure to future residents of Gilman, if any. The removal will eliminate the O&M currently committed to WP-8 thus O&M costs will be reduced slightly. The CTP would not be modified which could potentially reduce O&M on the site; however, it is expected that offsite O&M and land costs would negate any savings. The cost is significantly higher than on-site disposal due to transportation. The use of Highway 24 and Interstate 70 increases the risk of traffic accidents and road fatalities. As a stand-alone option, the removal of the waste rock is expected to result in up to 8 lbs/day decrease in loading to Segment 5a (same as Alternatives 3A or 3B). The existing runon, runoff and sediment retention facilities would remain in place, at least over the short term. If source removal fails to meet expectations, the runoff collection facilities and/or vegetation actions could be expanded. The small cost of these additional items is covered under the contingency.

7.8.1 Alternative 3C: Threshold Criteria Evaluation

Evaluation of Alternative 3C with respect to the threshold criteria is presented in this section.

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7.8.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 3C is generally protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Alternative 3C does not include any additional land use controls or zoning restrictions beyond that provided under previous actions, and the alternative does nothing to reduce future reliance on ICs that are already in place. Alternative 3C marginally reduces future reliance on ICs in the former Town of Gilman by the removal of waste rock piles.

Because of the continued risks to aquatic biota in Segment 5a, Alternative 3C is not considered protective of the environment. The RAO would not be met because Alternative 3C is not capable of achieving the required metal load reduction.

7.8.1.2 Compliance with ARARs

Evaluation of Alternative 3C with respect to the ARARs is presented in this section.

Chemical-Specific ARARs

Waste rock removal prescribed under Alternative 3C will not achieve the chemical-specific ARARs (WQS) in the spring.

Action-Specific ARARs

Alternative 3C is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 3C is expected to meet the location-specific ARARs. Removal of WP-14 will likely destabilize and collapse the Copper Tipple Loading Building which may be classified as an historic structure. Historic features and cultural resources will be identified through consultation with the SHPO.

TBCs

Alternative 3C is expected to meet the TBC guidance.

7.8.2 Alternative 3C: Primary Balancing Criteria Evaluation

Evaluation of Alternative 3C with respect to the five primary balancing criteria is presented in this section.

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7.8.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

While more of the waste rock piles are removed under this alternative, the magnitude of residual risk is not expected to be reduced any further than that described under Alternative 3A.

Given the steep terrain, it is reasonable to expect that some acid-generating waste rock will remain on the hillsides due to lack of access. The physical removal of the mine waste will not eliminate the source; metals will continue to leach from the freshly exposed bedrock and underlying soils for an undetermined period of time, impacting surface runoff and groundwater.

As the waste rock piles cannot be tied to the magnitude or duration of the increased metals within the Belden groundwater, this alternative provides no reduction in the magnitude or residual risk.

Loading from upstream sources is not controlled under any of the Alternatives.

Adequacy and Reliability of Controls

The response actions will result in a small long-term reduction in metal loading through physical removal. However, the loading studies indicate that this action will not be adequate to consistently achieve the RAO under all flow conditions.

Only small changes in water quality are expected as a result of the remedial actions; these changes will likely not be detectable with conventional surface water monitoring techniques.

Future O&M of the materials will not be required as they are disposed of offsite.

7.8.2.2 Short-Term Effectiveness

Community Protection

The use of Highway 24 and Interstate 70 increases the risk of traffic accidents and road fatalities; thus, Alternative 3C provides the lowest short-term community protection.

Fugitive dust emissions can be readily mitigated through implementation of conventional dust control measures, such as wetting or applying dust suppressants to haul roads or material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation sites and by implementing effective dust control.

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Worker Protection

There are more worker protection issues associated with Alternative 3C compared to the other alternatives because more waste rock is moved farther. The issues include increased traffic safety risks, heavy equipment operations, physical hazards associated with working on steep slopes, dust inhalation, and ingestion of metals.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. In addition site hazards, such as rock falls and avalanches in the canyon, increase the probability of accidents. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Mine waste excavation and relocation presents an increased risk to workers that may not be justifiable in terms of the protection offered to the environment.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

Potential Environmental Impacts

The waste rock removal from steep slopes will result in some impacted sediment transport to Rock Creek and the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and BMPs (e.g., silt fencing) will minimize but not eliminate sediment transport. Alternative 3C maintains the highest potential for impacts because more waste rock is moved and due to the steep terrain the chances of rock falls and avalanches caused by remedial activities become more likely and the ability to control less likely.

Time to Achieve RAOs

Post-construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition. It is not expected that the RAO will be met under any time frame by this alternative.

7.8.2.3 Reduction of TMV through Treatment

Alternative 3C does not meet the CERCLA preference for alternatives that reduce TMV through treatment.

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7.8.2.4 Implementability

Technical Feasibility

Alternative 3C is technically implementable; however, the slopes, potential rock slides, and the required use of aerial trams and draglines make this alternative potentially less feasible to be fully implementable because they involve removal of all waste rock piles.

The location of the Copper Tipple Building may make the complete removal of WP-14 infeasible if the building cannot be removed due to historic significance.

Administrative Feasibility

Successful implementation of Alternative 3C will require coordination among EPA, CDPHE, the railroad, the current landowner, and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. More coordination will be necessary due to offsite relocation of the waste rock. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available.

7.8.2.5 Cost

Estimated costs for Alternative 3C are summarized in Table 29. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 3C are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included.

Table 29 Alternative 3C Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 5,382,000 $ 811,000 $ 16,074,000

7.8.3 Alternative 3C: Modifying Criteria

Evaluation of Alternative 3C with respect to the modifying criteria is presented in this section.

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7.8.3.1 State Acceptance

State acceptance is unknown.

7.8.3.2 Public Acceptance

Public acceptance is likely.

7.9 DETAILED ANALYSIS OF ALTERNATIVE 4A: GROUNDWATER COLLECTION AND TREATMENT, OTP/REX FLATS

This alternative addresses the potential loading within the lower reach of Eagle River Basin Segment 5a from the OTP/Rex Flats from groundwater. Groundwater seepage from two former tailings sites that would otherwise enter the river would be collected in groundwater interceptor trenches along the west bank of the river at the OTP and along the south bank of the river at Rex Flats. The interceptor pipes (see Figure 21) would be installed approximately 3 feet bgs and vertical barrier walls of impermeable liner would be installed on the downgradient walls of the trench. Collected water would flow to sumps and duplex-pump lift stations that pump the water to a new water treatment facility sized to treat 250 gpm for 180 days per year. The existing WTP does not have the capacity to accept the water from the collection system. The description and cost estimate for the collection system and treatment plant were extracted from ERM (2007a), Remediation Feasibility Study, Bolts Lake Area and Areas within OU-1 of the Eagle Mine Site [see ERM (2007a) Figure 4C, Detail 1].

This proven technology requires no innovative or non-standard equipment. Physical space for the trenches is readily available to allow installation. Because a new treatment facility is part of the alternative, the increased treatment requirement does not place a burden on the capabilities of the existing WTP. A visible seep along Tigiwon Road would be captured and treated.

Based on loading to the river in this reach, a groundwater collection system at Rex Flats and the OTP could yield a net decrease in zinc loading of 1 to 3 lbs/day zinc (see Section 4.5 and Table 18). This is a modest, achievable target and a modified system or secondary backup system is not expected to be necessary.

7.9.1 Alternative 4A: Threshold Criteria Evaluation

Evaluation of Alternative 4A with respect to the threshold criteria is presented in this section.

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Figure 21 Proposed Interceptor Trenches (Alternatives 4A and 4B) at the OTP/Rex Flats

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7.9.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 4A is generally protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Trespass restrictions will probably not need to be upgraded to protect the selected remedy. The alternative does nothing to reduce future reliance on ICs that are already in place.

Because of the continued risks to aquatic biota in Segment 5a, Alternative 4A is not considered protective of the environment. The RAO would not be met because Alternative 4A is not capable of achieving the required metal load reduction.

7.9.1.2 Compliance with ARARs

Evaluation of Alternative 4A with respect to the ARARs is presented in this section.

Chemical-Specific ARARs

This alternative is not capable of achieving the metal loading reductions needed to meet the ARAR in March and April because OTP/Rex Flats has proven to be a minor source of COCs to the river, and the primary loading source enters the river upstream of this area.

Action-Specific ARARs

Alternative 4A is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 4A is expected to meet the location-specific ARARs.

TBCs

Alternative 4A is expected to meet the TBC guidance.

7.9.2 Alternative 4A: Primary Balancing Criteria Evaluation

Evaluation of Alternative 4A with respect to the five primary balancing criteria is presented in this section.

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7.9.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

Risks to aquatic biota will remain above acceptable levels during March and April of most years, thus Alternative 4A provides no reduction in the magnitude of residual risk.

Adequacy and Reliability of Controls

The response actions will result in a small long-term reduction in metal loading through collection and treatment. However, the loading studies indicate that this action will not be adequate to consistently achieve the RAO under all flow conditions and does not address the primary loading source to the river. Loading from upstream sources is not controlled under any of the Alternatives.

Only small changes in water quality are expected as a result of the remedial actions; these changes will likely not be detectable with conventional surface water monitoring techniques.

Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Effective trespass restrictions may be necessary to protect the selected remedy. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

7.9.2.2 Short-Term Effectiveness

Community Protection

Non-workers will be excluded from the active remediation site at OTP/Rex Flats.

Fugitive dust emissions can be readily mitigated through implementation of conventional dust control measures, such as wetting or applying dust suppressants to haul roads or material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation sites and by implementing effective dust control.

Worker Protection

Worker protection issues under Alternative 4A include increased traffic safety risks, heavy equipment operations, dust inhalation, and ingestion of metals. Risks to workers at OTP/Rex Flats are lower than all other alternatives because site conditions such as rock falls and avalanches in the canyon are not of concern in the area.

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Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

Potential Environmental Impacts

Construction activities may result in impacted sediment transport to the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and BMPs (e.g., silt fencing) will minimize but not eliminate this damage.

Time to Achieve RAOs

Post-construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition; however, during the spring the small zinc load reduction offered by this alternative may not be detectable. It is not expected that the RAO will be met under any time frame by this alternative.

7.9.2.3 Reduction of TMV through Treatment

Collection of groundwater and treatment at the WTP meets the CERCLA preference for alternatives that reduce TMV through treatment.

7.9.2.4 Implementability

Technical Feasibility

Alternative 4A is technically implementable. Alternative 4A is expected to be technically feasible from an O&M perspective because the system will be designed to operate with minimal supervision during the operational months of March and April.

Administrative Feasibility

Successful implementation of Alternative 4A will require coordination between the landowner and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Protection of the treatment plant facilities from vandalism may prove to be a problem. Environmental Covenants will

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be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available.

7.9.2.5 Cost

Estimated costs for Alternative 4A are summarized in Table 30. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 4A are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment at two facilities, and project management are included.

Table 30 Alternative 4A Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 747,000 $ 937,000 $ 13,177,000

7.9.3 Alternative 4A: Modifying Criteria

Evaluation of Alternative 4A with respect to the modifying criteria is presented in this section.

7.9.3.1 State Acceptance

CDPHE recommended this alternative for evaluation.

7.9.3.2 Public Acceptance

Public acceptance is unknown.

7.10 DETAILED ANALYSIS OF ALTERNATIVE 4B – IRM REACTION WALL AT OTP/REX FLATS

This alternative is similar to Alternative 4A but instead of treating the groundwater in the OTP/Rex Flats area via a conventional pump and treat system, trenches will be filled with the in situ treatment material, IRM, to create a PRB. In tank pilot tests using IRM have proven effective at removing metals from Site waters. The proposed remediation system is similar to the Belden system (Adrian Brown 2012) and involves constructing two, 100

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foot-long, 15-foot-deep, 11-foot-wide PRBs, each containing 200 cy (290 tons) of IRM along the west bank of the river at the OTP and along the south bank of the river at Rex Flats, at roughly the same locations as the interceptor trenches shown in Figure 21, except that the IRM trench at the OTP would be on the south end to address the visible seep along Tigiwon Road. Groundwater moving to the river from the OTP/Rex Flats area would be treated in situ when passing through the material. This system does not place a burden on the capabilities of the existing WTP by contributing additional flow.

Based on the modest amount of zinc loading to the river in this reach, an average of 0.7 lbs/day (Table 5), the in situ IRM system at Rex Flats and the OTP was designed to remove 10 lbs/day zinc for 30 years. The 10 lbs/day figure is a design specification; the IRM is capable of absorbing more 10 lbs/day over the short term.

7.10.1 Alternative 4B: Threshold Criteria Evaluation

Evaluation of Alternative 4B with respect to the threshold criteria is presented in this section.

7.10.1.1 Overall Protectiveness of Human Health and the Environment

Alternative 4B is generally protective of human health because the ICs designed to limit human exposure to metal COCs, put in place under the previous actions, apply here as well. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Trespass restrictions will not be necessary to protect the selected remedy. The alternative does nothing to reduce future reliance on ICs that are already in place.

Because of the continued risks to aquatic biota in Segment 5a, Alternative 4B is not considered protective of the environment. The RAO would not be met because Alternative 4B is not capable of achieving the required metal load reduction needed in March and April.

7.10.1.2 Compliance with ARARs

Evaluation of Alternative 4B with respect to the ARARs is presented in this section.

Chemical-Specific ARARs

This alternative is not capable of achieving the metal loading reductions needed to meet the ARAR in the spring because OTP/Rex Flats has proven to be a minor source of COCs to the river, and the primary loading source enters the river upstream of this area.

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Action-Specific ARARs

Alternative 4B is expected to meet the action-specific ARARs.

Location-Specific ARARs

Alternative 4B is expected to meet the location-specific ARARs.

TBCs

Alternative 4B is expected to meet the TBC guidance.

7.10.2 Alternative 4B: Primary Balancing Criteria Evaluation

Evaluation of Alternative 4B with respect to the five primary balancing criteria is presented in this section.

7.10.2.1 Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

Risks to aquatic biota will remain above acceptable levels during March and April of most years, thus Alternative 4B provides no reduction in the magnitude of residual risk.

Adequacy and Reliability of Controls

The response actions will result in a small long-term reduction in metal loading through in situ treatment. However, the loading studies indicate that this action will not be adequate to consistently achieve the RAO under all flow conditions and does not address the loading source in the Belden area. Loading from upstream sources is not controlled under any of the alternatives.

Only small changes in water quality are expected as a result of the remedial actions; these changes may not be detectable with conventional surface water monitoring techniques.

Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

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7.10.2.2 Short-Term Effectiveness

Community Protection

Non-workers will be excluded from the active remediation site at OTP/Rex Flats.

Fugitive dust emissions can be readily mitigated through implementation of conventional dust control measures, such as wetting or applying dust suppressants to haul roads or material piles. Ingestion of metals can be mitigated by excluding non-workers from active remediation sites and by implementing effective dust control.

Worker Protection

Worker protection issues associated with Alternative 4B include increased traffic safety risks, heavy equipment operations, dust inhalation, and ingestion of metals. Risks to workers at OTP/Rex Flats are lower than all other alternatives due to the area not being located within a canyon.

Risks are inherent in operating heavy earthmoving equipment. Although these risks can be reduced through worker safety training programs, they cannot be completely eliminated. A site safety program will be essential to controlling and reducing risks to workers under this and all alternatives.

Risks associated with inhaling dust include metal intake and possible respiratory illness, such as silicosis. These risks can be mitigated through dust monitoring and suppression and use of appropriate PPE, if warranted.

Metal ingestion can be mitigated through the use of appropriate PPE and reasonable personal hygiene.

Potential Environmental Impacts

Some construction activities may result in impacted sediment transport to the Eagle River with possible damage to sensitive aquatic ecosystems. As this system requires replacement after several years, these impacts could reoccur. Proper use of storm water controls and BMPs (e.g., silt fencing) will minimize sediment transport.

Time to Achieve RAOs

Post-construction monitoring will be used to determine when remediated areas have reached a long-term/stable condition. It is not expected that the RAO will be met under any time frame by this alternative.

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7.10.2.3 Reduction of TMV through Treatment

In situ treatment meets the CERCLA preference for alternatives that reduce TMV through treatment.

7.10.2.4 Implementability

Technical Feasibility

Alternative 4B is technically implementable. Large boulders in the subsurface are expected to make trench excavation difficult. The trenches will not be keyed into bedrock, thus allowing the potential for underflow of contaminated groundwater.

Administrative Feasibility

Successful implementation of Alternative 4B will require coordination between the current landowner and CBS. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Protection of the remedy from vandalism has proven to be a problem. In this regard, Alternative 4B is more feasible than most other alternatives due to the use of an underground system.

Environmental Covenants will be required where engineered features are constructed and where waste above levels safe for unrestricted use is deposited during the remedial action.

Availability of Materials and Labor

All the materials and services needed to implement the remedy are available. IRM is available but delivery times are long.

7.10.2.5 Cost

Estimated costs for Alternative 4B are summarized in Table 31. The net worth of this alternative was calculated on the basis of a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates for Alternative 4B are presented in Appendix F. The annualized costs of surface water and groundwater monitoring, O&M of the current remedy, water treatment, and project management are included.

Table 31 Alternative 4B Estimated Costs

Total Capital Annual O&M and Water

Treatment Net Present Worth

$ 115,000 $ 807,000 $ 15,883,000

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7.10.3 Alternative 4B: Modifying Criteria

Evaluation of Alternative 4B with respect to the modifying criteria is presented in this section.

7.10.3.1 State Acceptance

State acceptance is unknown.

7.10.3.2 Public Acceptance

Public acceptance is unknown.

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COMPARATIVE ANALYSIS OF ALTERNATIVES 8.0

This section evaluates the relative performance of the alternatives with respect to each of the two threshold and five balancing criteria to identify the advantages and disadvantages of each alternative in side-by-side comparisons. Evaluations of the two modifying criteria, State Acceptance and Public Acceptance, are not presented here but will be presented in the ROD.

The results of this comparative analysis are summarized in tabular format in Table 32 and are provided at the end of this section.

8.1 OVERALL PROTECTION OF HUMAN HEALTH

Human health risks are minimized at the Site because the identified risks have been adequately and reliably addressed through prior remedial actions and prescribed ICs. As such, the protection of human health is considered to be secondary to the environment in this FFS. To the extent that human health becomes an issue, the following criteria could be used as yardsticks in evaluating the enhancement of human health protection offered by each alternative:

• Degree of reliance on ICs to manage residual risks

• Adequacy and reliability of waste containment or treatment actions

• Timeframe to achieve enhancements.

Alternatives 3A, 3B, and 3C are the only alternatives that could enhance protection of human health by reducing exposure to cadmium, lead, and other metals through the removal and containment of some or all of the waste rock at Gilman. However, Alternatives 3A and 3B do require a repository for this waste on the existing CTP. ICs at the CTP may need to be enhanced upon placement of this material. Alternative 3C is the only alternative that has an offsite component; while human health protection onsite may be improved, the community at large might be at risk during transportation and long-term offsite management of the waste rock.

8.2 OVERALL PROTECTION OF THE ENVIRONMENT

The only factor considered in the comparative analysis of alternatives with respect to overall protection of the environment was compliance with chemical-specific ARARs which is essentially achievement of the RAO.

Only Alternatives 2A and 2C are designed to address the metals loading in Segment 5a, thus they have the best potential of achieving the RAO and offer the best overall protection of the environment. Alternative 2B is not expected to reduce the metal load in

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the Belden reach thus it cannot independently meet the RAO. The alternatives that address metal sources in waste rock or groundwater at OTP/Rex Flats cannot achieve the RAO and offer only a small reduction of risk to the environment.

8.3 COMPLIANCE WITH ARARS AND TBCS

Alternative 1 represents a continuation of current conditions. Under current conditions, periodic exceedances of the surface water ARARs (WQS) will occur. Alternatives 2A and 2C are considered capable of achieving the chemical-specific ARARs for surface water. Upon full implementation, the other alternatives will not result in compliance with the surface water ARARs.

All of the alternatives are equally capable of meeting the action-specific and location-specific ARARs. Waste rock removal alternatives 3A, 3B, and 3C may destabilize and collapse the Copper Tipple Loading Building which may be classified as an historic structure. Historic features and cultural resources will be identified through consultation with the SHPO.

8.4 LONG-TERM EFFECTIVENESS AND PERMANENCE

This subsection presents the comparative analysis of remedial alternatives with respect to the balancing criterion of long-term effectiveness and permanence. Two measures are used, the relative magnitude of residual risks and the adequacy and reliability of controls.

8.4.1 Magnitude of Residual Risks

Sources in Belden exposed to groundwater constitute the greatest residual risk. Alternatives 2A and 2C are designed to intercept and treat the groundwater along its seasonal flow path to the river. While both alternatives involve removing large quantities of contaminated railroad fill from Belden, reducing the source term, neither alternative addresses the source entirely, thus the magnitude of residual risk is rated moderate. None of the other alternatives are designed to deal with the metal source or capture the groundwater at Belden; therefore the magnitude of residual risk associated with these alternatives is rated high.

8.4.2 Adequacy and Reliability of Engineering Controls

From an engineering perspective, the disposal of waste rock in onsite above-ground repositories with covers, as called for under Alternatives 3A and 3B, and in an offsite landfill as called for under Alternative 3C, represents a permanent and reliable method

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but is subject to cover failure and leaks. The collection of groundwater and conventional treatment process (Alternatives 2A and 4A) is inherently more complicated and subject to leaks and upsets. The reliability of in situ treatment (Alternatives 2C and 4B) is rated low, primarily due to lack of in-ground pilot tests; the same is true for the in-mine treatment proposed in Alternative 2B. Reliability issues can be resolved with adequate testing.

8.5 SHORT-TERM EFFECTIVENESS

This section presents the comparative analysis of remedial alternatives with respect to the balancing criterion of short-term effectiveness.

8.5.1 Risks to the Local Communities

As indicated in Table 32, potential risks to local communities during remedial actions are quite similar. For most alternatives, the risks posed by earthmoving and construction activities are very low because the activities will be limited to areas that are not accessible to the public. Alternative 3C involves the greatest risk due to the use of Highway 24 and Interstate 70 as a haul route, thereby increasing the risk of traffic accidents and road fatalities.

8.5.2 Potential Risks to Workers

Potential risks to workers during remedial actions are low for Alternatives 2A, 2B, 2C, 4A, and 4B where conventional risks posed by earthmoving and construction activities can be readily mitigated through engineering controls and safety training. Under Alternative 3A, workers may be exposed to moderate risks due to the physical hazards of excavating and hauling waste rock. Under Alternative 3B and 3C, risk to workers is rated high due to the physical hazards of removing waste rock from steep slopes. There are essentially no potential risks to workers under Alternative 1.

8.5.3 Potential Environmental Impacts

The implementation of all the alternatives may result in environmental impacts. Waste rock removal may result in sediment impacts to surface water and IRM barriers could increase iron loading to the river.

Under Alternative 3A and 3B, the cap at the CTP will be reopened and disturbed, potentially contributing sediments to the river. During the early stages of revegetation, the soil-capped areas will be susceptible to erosion and the river could receive high sediment loads during rainfall events if effective controls are not put in place.

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8.5.4 Time Until RAOs Are Achieved

Only Alternatives 2A and 2C are expected to achieve the RAO in approximately 1 to 2 years.

Alternative 2B, in-mine precipitation, is expect to require a significantly longer time to implement (30 years) than other alternatives (1 to 2 years) due to mixing problems in the mine pool. Additionally, there is no indication that accomplishing the goal of Alternative 2B, lower metal concentrations in the mine pool, will lower the metal concentrations in Belden groundwater over any time period.

The RAO will not be achieved under Alternatives 3A, 3B, 3C, 4A and 4B.

8.6 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH TREATMENT

All the alternatives that contain conventional treatment and in situ treatment reduce TMV in one form or another. Alternatives 3A, 3B, 3C do not meet the CERCLA preference for alternatives that reduce TMV through treatment.

8.7 IMPLEMENTABILITY

This section presents the comparative analysis of alternatives with respect to the implementability criterion.

8.7.1 Technical Feasibility

All the action alternatives are readily constructible. The in situ treatment prescribed under Alternative 2B in the accessible Bleakhouse portion of the mine pool is feasible but innovative as few large-scale systems have been constructed to date.

8.7.2 Administrative Implementability

The implementation of all the action alternatives will require varying degrees of coordination among EPA, State and local agencies, the railroad, Colorado Department of Transportation, and landowners. Effective ICs will require the cooperation of landowners in administering easements and deed restrictions on waste repositories. Under any circumstance, administrative implementability is expected to be complicated by the fact that CBS would be implementing the remediation on land it does not own.

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The level of administrative coordination needed for waste rock hauling on public roads (Alternative 3C) is higher than the other alternatives where, for the most part, the remedy would be implemented on land not open to the general public.

8.7.3 Availability of Labor and Materials

The availability of material and labor does not significantly affect the implementation of any of the alternatives.

8.8 COST

Detailed cost estimates for each alternative are presented in Appendix F.

The low-cost alternative is 2B. The present worth cost of Alternative 2B is low because the in situ treatment of mine water alleviates much of the input to the WTP, greatly reducing the projected O&M cost. Although the present worth cost of Alternative 2B is attractive, the treatment of the mine pool has not shown any indications that it would alter loading to the river, thus it would never meet the RAO independently. Alternative 2A and 2C are considered to be the most cost-effective alternatives, at approximately $11 million (30 year NPW).

The higher costs of Alternatives 3A, 3B, 3C, and 4A are not justified in increased protectiveness or effectiveness. While the costs of Alternatives 2C and 4B make the IRM attractive treatment options, the assumptions of PRB life and planned obsolescence may be too optimistic, making the alternatives appear to be less costly than they will ultimately prove to be.

8.9 COMPARATIVE ANALYSIS SUMMARY

The FS process has identified a range of response actions that could be implemented to reduce loading to the river and meet the RAO. The range of options was initially narrowed from a broader range of technologies and process options with the input from the Stakeholders to assemble a list of alternatives that could be used in this environmental setting. All the alternatives address the principal threat, impacts to surface water quality, to varying degrees. All the alternatives are implementable from an engineering perspective. The following summary highlights the key distinctions between the alternatives and the preferred remedy.

Overall Protection/Compliance with ARARs

The principal points of comparison are the alternative’s ability to achieve the RAO and the time required to meet that objective.

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• Alternatives 2A and 2C are considered to be capable of achieving the RAO. The other alternatives are not expected to achieve the objective because they address minor sources of zinc.

• Only Alternatives 2A and 2C are expected to achieve the RAO in a reasonable timeframe, approximately 1 to 2 years.

Effectiveness and Cost

Depending on the setting, the alternatives differ with respect to their effectiveness and their cost.

• Alternative 2A and 2C are expected to be effective for a moderate cost.

• Alternative 2B, in mine treatment, is designed to lower the zinc in the mine pool by precipitating metals directly in the mine. The long term cost of this alternative is substantially less than the others because in mine treatment goes directly to reducing treatment costs which is a major component of the 30-year cost. While attractive from a cost perspective, in mine treatment does not address the contaminated groundwater in Belden, thus there is no indication that it can independently achieve the RAO. A link between the mine pool water and the groundwater in Belden has not been established.

• Waste rock removal under Alternatives 3A, 3B, and 3C is attractive to the public but it does not meet the goal of the FS. Waste rock removal has been shown to be costly and adds a degree of risk to the public and workers by excavation and transportation. Moreover, as a response action, it has not been shown to be effective in lowering the zinc load in the river to a point where the RAO will be achieved.

• It is expected that either of alternatives 4A or 4B will be effective in controlling the small amount of zinc loading contributed by OTP/Rex Flats. However, the primary zinc loading occurs upstream and a remedy at OTP/Rex Flats will not lower the zinc load in the river to a point where the RAO will be achieved.

Preferred Remedies

The preferred remedies are 2A and 2C because they are expected to control loading in Belden and Rock Creek and achieve the RAO in a reasonable time frame at a moderate cost. Source material is removed under both alternatives. Alternative 2C requires less maintenance than Alternative 2A and the section of pipeline between Belden and Rock Creek is eliminated, reducing exposure to spills to the river.

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Criterion

Alternative 1 No Added Action

Alternative 2A Groundwater Collection and Treatment, Belden

and Rock Creek

Alternative 2B In-mine Precipitation in Bleakhouse mine pool

Alternative 2C IRM Reaction Wall in

Belden

Alternative 3A Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite

Alternative 3B Excavate, Transport and

Dispose of All Waste Rock Onsite

Alternative 3C Excavate, Transport and

Dispose of All Waste Rock Offsite

Alternative 4A Groundwater Collection and Treatment, OTP/Rex

Flats

Alternative 4B IRM reaction wall at

OTP/Rex Flats

Overall Protection of Human Health and the Environment How the Alternative Enhances Human Health Protection

Alternative 1 does not enhance human health protection measures that have already been implemented. Alternative 1 does nothing to reduce future reliance on institutional controls to manage residual human health risk.

Same as Alternative 1.

Same as Alternative 1. Same as Alternative 1. Alternative 3A marginally enhances human health protection in Gilman by the removal of WP-8.

Alternative 3B enhances human health protection in Gilman by the removal of several waste rock piles.

Same as Alternative 3B. Same as Alternative 1. Same as Alternative 1.

How the Alternative Provides Environmental Protection

Alternative 1 is not capable of achieving zinc load reduction necessary to meet ARARs.

Alternative 2A is capable of achieving zinc load reduction necessary to meet ARARs.

Alternative 2B would probably not be capable of achieving zinc load reduction necessary to meet ARARs.

Same as Alternative 2A.

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1.

Compliance with ARARs

Compliance with Chemical-Specific ARARs

Alternative 1 is not capable of achieving the metal loading reductions needed to meet the chemically-specific ARARs.

Alternative 2A is not capable of achieving the metal loading reductions needed to meet the ARAR under all conditions because it does not remove the background load.

Alternative 2B would probably not be capable of achieving the metal loading reductions needed to meet the chemically-specific ARARs.

Same as Alternative 2A. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1.

Compliance with Action-Specific ARARs

Alternative 1 is capable of achieving the action-specific ARARs.

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1.

Compliance with Location-Specific ARARs

Alternative 1 is capable of achieving the location-specific ARARs.

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. May not meet Historic Preservation ARARs due to building removal at WP-14.

Same as Alternative 3A. Same as Alternative 3A. Same as Alternative 1. Same as Alternative 1.

Compliance with Other Criteria, Advisories, and Guidance (TBCs)

Alternative 1 is capable of achieving the TBCs..

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1.

Long-Term Effectiveness and Permanence

Magnitude of Residual Risks

Alternative 1 provides no reduction in the magnitude of residual risk.

Alternative 2A is not designed to address the metals source thus there is some residual risk.

Loading from upstream (background) sources is not controlled under any of the alternatives.

Alternative 2B is not designed to address the metals source thus there is some residual risk.

The RAO will not be met because the treatment of main mine pool water does not address Mill Level seepage.

Loading from upstream (background) sources is not controlled under any of the alternatives.

Same as Alternative 2A.

Potential for the RAO not to be met when one PRB is replaced with the next.

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1.

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Criterion

Alternative 1 No Added Action

Alternative 2A Groundwater Collection and Treatment, Belden

and Rock Creek

Alternative 2B In-mine Precipitation in Bleakhouse mine pool

Alternative 2C IRM Reaction Wall in

Belden

Alternative 3A Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite

Alternative 3B Excavate, Transport and

Dispose of All Waste Rock Onsite

Alternative 3C Excavate, Transport and

Dispose of All Waste Rock Offsite

Alternative 4A Groundwater Collection and Treatment, OTP/Rex

Flats

Alternative 4B IRM reaction wall at

OTP/Rex Flats

Adequacy and Reliability of Controls

The controls used for O&M of the existing remedy are adequate and reliable. The controls proposed for Alternative 1 are not adequate or reliable for preventing environmental risk.

The engineering controls associated with Alternative 2A are expected to be adequate and reliable. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Effective trespass restrictions may be necessary to protect the selected remedy.

Innovative technology but not a proven track record. Controls for in situ treatment are not as reliable as controls for conventional engineered remedies. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative.

Same as Alternative 2B. The engineering controls associated with Alternative 2A are expected to be adequate and reliable. Access agreements and perpetual easements may be needed to implement all the actions proposed under this alternative. Effective trespass restrictions may be necessary to protect the selected remedy.

Institutional controls designed to protect the repository cap will be necessary.

Same as Alternative 3A. Same as Alternative 3B. Same as Alternative 2A. Same as Alternative 2B.

Short-Term Effectiveness

Protection of the Community During the Remedial Action

Risks to the community are the same as under current conditions.

Risks to the community are the same as Alternative 1 because the remedial activities will be conducted in areas of the Site that are off limits to the general public.

Same as Alternative 2A. Same as Alternative 2A. Same as Alternative 2A. Same as Alternative 2A. Risks to the community are higher than all other alternatives due to the use of Highway 24 and Interstate 70 as haul routes, increasing the risk of traffic accidents and road fatalities.

Same as Alternative 2A. Non-workers will be excluded from active remediation sites at the OTP and Rex Flats.

Same as Alternative 4A. .

Protection of Workers During Remedial Action

Risks to workers are the same as under current conditions.

Worker protection issues under Alternative 2A include increased traffic safety risks, heavy equipment operations, physical hazards associated with rock falls and avalanches, dust inhalation, and ingestion of heavy metals. Risks to workers can be mitigated.

Risk to workers is lower than Alternative 2A and 2C as a result of less heavy equipment operation; however, there may be increased risk associated with working underground in the mine.

Same as Alternative 2A. There are more worker protection issues associated with waste rock removal than with the other alternatives. These include increased traffic safety risks, heavy equipment operations, physical hazards associated with working on steep slopes, dust inhalation, and ingestion of heavy metals.

Risk to workers is higher than Alternative 3A because more waste rock is moved and access to the additional waste rock is difficult and limited.

Risks to workers are higher than Alternative 3B because waste rock is moved farther.

Risk to workers is lower than Alternative 2A because there are no physical hazards associated with rock falls and avalanches.

Same as Alternative 4A.

Potential Environmental Impacts Caused by the Remedial Actions

Risks to the environment are the same as under current conditions.

Construction could result in impacted sediment transport to the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and best management practices (BMPs) will minimize sediment loss to the river.

Same as Alternative 1. Same as Alternative 2A. Waste rock removal is likely to result in impacted sediment transport to Rock Creek and the Eagle River with possible damage to sensitive aquatic ecosystems. Proper use of storm water controls and best management practices (BMPs) will minimize sediment loss to surface water.

Potential impacts are highest of any of the alternatives because more waste rock is removed and access to this waste is in areas that BMPs may be difficult to fully protect the environment.

Same as Alternative 3B. Same as Alternative 2A. Same as Alternative 2A.

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Table 32 Comparative Analysis of Remedial Alternatives with Respect to Two Threshold and Five Balancing Criteria

\\DHINRICHS-990\Projects\CBS Eagle\FFS\FFS-2012\Table 32_2013.docx Page 3 of 3

Criterion

Alternative 1 No Added Action

Alternative 2A Groundwater Collection and Treatment, Belden

and Rock Creek

Alternative 2B In-mine Precipitation in Bleakhouse mine pool

Alternative 2C IRM Reaction Wall in

Belden

Alternative 3A Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite

Alternative 3B Excavate, Transport and

Dispose of All Waste Rock Onsite

Alternative 3C Excavate, Transport and

Dispose of All Waste Rock Offsite

Alternative 4A Groundwater Collection and Treatment, OTP/Rex

Flats

Alternative 4B IRM reaction wall at

OTP/Rex Flats

Time Until RAOs Are Achieved

RAOs are not achieved under Alternative 1.

One to two years. In situ treatment of the mine pool may not ever achieve the RAO; 30 years has been assumed.

One to two years. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1.

Reduction of TMV Through Treatment

Reduction of TMV Through Treatment

Alternative 1 meets the CERCLA preference for alternatives that reduce TMV through treatment but provides no additional TMV reduction.

Alternative 2A meets the CERCLA preference for alternatives that reduce TMV through treatment.

Same as Alternative 2A. Same as Alternative 2A. Alternative 3A does not meet the CERCLA preference for alternatives that reduce TMV through treatment.

Same as Alternative 3A. Same as Alternative 3A. Same as Alternative 2A. Same as Alternative 2A.

Implementability

Technical Feasibility All the actions described under Alternative 1 are implementable.

All the actions described under Alternative 2A are implementable.

Limited by lack of electricity. Rock falls and shallow bedrock hamper constructability.

All the actions described under Alternative 2B are implementable. Limited by lack of electricity.

Access to the mine pool is limited.

All the actions described under Alternative 2C are implementable. Rock falls hamper constructability.

Depth of bedrock may hamper constructability by depth being too shallow or too deep.

All the actions described under Alternative 3A are implementable.

Alternative 3B is technically implementable but is viewed as the least feasible alternative because it involves removal of all waste rock piles.

Same as Alternative 3B. All the actions described under Alternative 4A are implementable.

All the actions described under Alternative 4B are implementable.

Administrative Feasibility Alternative 1 has been implemented.

Successful implementation of Alternative 2A will require coordination between CBS, the landowner and the railroad. Access agreements and perpetual easements may be needed. More effective trespass restrictions may be necessary to protect the selected remedy.

Successful implementation of Alternative 2B will require coordination between CBS and the landowner. Access agreements and perpetual easements may be needed.

Same as Alternative 2A. Successful implementation of Alternative 3A will require coordination between CBS, the landowner and the railroad.

Same as Alternative 3A. Same as Alternative 3A with more coordination necessary due to offsite disposal.

Successful implementation of Alternative 4A will require coordination between CBS and the landowner.

Same as Alternative 2C.

Availability of Material and Labor

Materials and labor needed to implement Alternative 1 are readily available.

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. IRM is available but delivery times are long.

Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 1. Same as Alternative 2C.

Cost – Summarized from tables in Appendix B

30 Year Cost, Net Present Worth

$10,825,000 $11,390,000 $5,080,000 $10,995,000 $14,590,000 $15,717,000 $16,074,000 $13,177,000 $15,883,000

Total Cost (30 year) Non Discount)

$25,026,000 $25,845,000 $10,565,000 $24,621,000 $28,791,000 $30,084,000 $30,513,000 $29,653,000 $25,142,000

Capital Cost $0 $385,000 $404,000 $635,000 $3,765,000 $5,058,000 $5,382,000 $747,000 $115,000

Ongoing O&M Cost (existing Rem)

$807,000 $807,000 $152,000 $773,000 $807,000 $807,000 $807,000 $807,000 $807,000

New Alternative related O&M

$0 $14,000 $160,000 $0 $0 $0 $3,500 $129,000 $0

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REFERENCES 9.0

Adrian Brown, P. E. 2012. Removal of Zinc from Seepage through the Belden Railway Grade. December 12.

AMEC Earth & Environment, 2009. Comments on the proposed scope of the Focused Feasibility Study. November 17.

Dames & Moore, 1986. Eagle Mine New Tailings Impoundment – Evaluation of Remedial Action Alternatives. May.

Dames & Moore, 1994. Final Construction Report, Remedial Activities at Waste Rock Piles, Eagle Mine, Gilman, Colorado. August 9.

Dames & Moore, 1995a. Rock Creek Extraction System Report, Eagle Mine, Minturn, Colorado. September 2.

Dames & Moore, 1995b. Work Plan for Waste Rock Pile Testing, Eagle Mine, Minturn, Colorado. September 15.

Dames & Moore, 1996a. Preliminary Data Interpretation Report No. 2 – Belden Groundwater Monitoring Program. November 15.

Dames & Moore, 1996b. Preliminary Data Interpretation Report No. 3 – Belden Storm Event/Snowmelt Surface Water Runoff Monitoring. November 27.

Dames & Moore, 1997a. Data Evaluation Report, Belden Area, Eagle Mine Site, Minturn, Colorado. December 1.

Dames & Moore, 1997b. Phase II CTP Groundwater Extraction Trenches Report, Eagle Mine Site, Minturn, Colorado. December 15.

Environmental Resources Management (ERM), 2006. Remedial Investigation Report, Bolts Lake Area and Areas within OU-1 of the Eagle Mine Site. September 15.

ERM, 2007a. Remediation Feasibility Study, Bolts Lake Area and Areas within OU-1 of the Eagle Mine Site. February 16.

ERM, 2007b. Site Investigation Report: North Gilman, Eagle Mine Site. September 7.

ERM, 2009. Email to Wendy Naugle, CDPHE-HMWMD, from Kenneth L. Waesche and Mike O’Keefe, ERM, containing unpublished surface water and groundwater data for the Bolts Lake Area and Areas within OU-1 of the Eagle Mine Site. July 14.

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ERWC Eagle Mine Ltd, 2009. Letter to Wendy Naugle, CDPHE-HMWMD, from Keith Kepler, ERWC Eagle Mine, Ltd dated November 12, 2009 providing comments on the September 29, 2009 presentation and the FFS List of Alternatives.

Kirkham, R.M., Houck, K.J., Funk, J., Mendel, D., and Siccard, K.R., 2012. Geologic Map of the Minturn Quadrangle, Eagle County, Colorado. Colorado Geol. Survey Open-File Report 09-07, scale 1:24,000.

Knight, M. and L. Hammock, 1965. Early Days on the Eagle. 49 pp.

Lovering, T. S., O. Tweto, and T. G. Lovering, 1978. Ore Deposits of the Gilman District, Eagle County, Colorado, U.S. Geol. Survey Prof. Paper 1017.

MFG, Inc., 2004. Technical Memorandum to the Eagle River Watershed Council regarding “Results for Geochemical Screening of Waste Rock, Belden Mill Site, Gilman, Colorado.” August 25.

Medine, 1991. Assessment of Contaminant Source, Transport, Transformation, and Impact in the Eagle River.

Morrison Knudsen Corporation (MK), 1992a. Field Investigation and Data Evaluation at Eagle Mine Site. Prepared for EPA Region VIII, WA No. 20-8L45. January.

MK, 1992b. Feasibility Study Addendum for the Eagle Mine Site, Minturn, Colorado. Prepared for EPA Region VIII, WA No. 20-8L45. June.

NewFields, 2006. Eagle Mine Annual Report – 2005, Eagle Mine Site, Minturn, Colorado. March 1.

NewFields, 2007a. Eagle Mine Site - Belden Groundwater Extraction System Performance Report. January 19.

NewFields, 2007b. Eagle Mine Annual Report – 2006, Eagle Mine Site, Minturn, Colorado. March 9.

NewFields, 2007c. Eagle Mine Site - Belden Groundwater Extraction System Performance Report No. 2. July 25.

NewFields, 2007d. Eagle Mine Site - Belden Groundwater Extraction System Performance Report No. 2, Revision 1. August 21.

NewFields, 2008a. Eagle Mine Annual Report – 2007, Eagle Mine Site, Minturn, Colorado. February 28.

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NewFields, 2008b. Eagle Mine Site - Belden Groundwater Extraction Performance Report No. 3, July 9.

NewFields, 2009. Eagle Mine Annual Report – 2008, Eagle Mine Site, Minturn, Colorado. March 2.

NewFields, 2010. Eagle Mine Annual Report – 2009, Eagle Mine Site, Minturn, Colorado. April 7.

NewFields, 2011. Eagle Mine Annual Report – 2010, Eagle Mine Site, Minturn, Colorado. March 11.

United States Environmental Protection Agency (EPA), 1988a. Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA Interim Final. EPA/540/G-89/004, OSWER Directive 9355.3-01. October.

EPA, 1988b. CERCLA Compliance with Other Laws Manual Draft Guidance. August.

EPA, 1989. Advancing the Use of Treatment Technologies for Superfund Remedies, OSWER Directive No. 9355.0-26.

EPA 1993. Record of Decision for Operable Unit Number 1, Eagle Mine Site. March 29.

EPA, 1995. Eagle Mine Operable Unit Number 1 Partial Consent Decree and Final Statement of Work - Part A.

EPA 1998. Record of Decision for Eagle Mine Operable Unit No. 2. July 21.

EPA 2007. The Use of Soil Amendments for Remediation, Revitalization and Reuse. Solid Waste and Emergency Response, EPA 542-R-07-013. December 2007.

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Key Reference Summaries

Many reports have been written that sought to identify the sources and quantity of metal loading to the Eagle River. Some of the more important reports whose conclusions are important to this FFS are briefly summarized below.

Assessment of Contaminant Source, Transport, Transformation, and Impact in the Eagle River (Medine 1991) – Dr. Allen Medine prepared this conceptual model of contaminant dynamics for the EPA for its use in the assessment of alternatives in a Feasibility Study Addendum (MK 1992b). The river was separated into eight reaches for assessment of contaminant loading. Zinc profiles and mass transport analyses based on data from April 1990 through March 1991 indicated that pre-runoff contaminant loading was the most significant. The Roaster Pile/Belden reach analysis indicated a positive gain of 60 kg/day zinc, which at that time was attributed to the Ben Butler and Tip Top mines, Roaster Gulch, and unaccounted loading from Eagle mine seepage and interactions with the alluvium. An additional 91 kg/day was reported for the Rock Creek reach, of which only 25 percent of the load increase was attributed to Rock Creek itself measured at station T-10. The remainder was thought to be contributed by the impacted alluvial systems of the river and Rock Creek, and by shallow groundwater.

Field Investigation and Data Evaluation at Eagle Mine Site (MK 1992a) – Morrison Knudsen was tasked by EPA to investigate nine aspects of the Site, then undergoing a state-led remedial action. One aspect investigated was the subsurface seepage of mine water into the colluvium along Rock Creek and loading to the river. Morrison Knudsen concluded that the present system of temporary ditches was not collecting all the seepage and recommended redesign of the collection system and Rock Creek culvert as part of future remedial actions to prevent seepage from entering the river.

Feasibility Study Addendum (FSA) for the Eagle Mine Site (MK 1992b) – The FSA evaluated an Eagle Mine/Rock Creek Seepage Alternative and five other potential remediation alternatives for the site. The FSA described and provided costs for four variations of the Eagle Mine/Rock Creek Seepage Alternative.

Eagle Mine Operable Unit Number 1 Partial Consent Decree and Final Statement of Work - Part A (EPA 1995) – The CD/SOW directed the Settling Defendant to characterize rainfall and snowmelt from the waste rock piles in Belden and Rock Creek in order to assess the effects of runoff on Eagle River water quality (Task 1) and perform groundwater monitoring in Belden to “estimate metals loading to the Eagle River via groundwater seepage flow from the waste rock piles above Belden” (Task 3A).

Preliminary Data Interpretation Report No. 2 – Belden Groundwater Monitoring Program (Dames & Moore 1996a) – Groundwater chemistry and hydraulic conductivity results were used to predict potential zinc loading in the Belden reach of the river. PDIR

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No. 2 identified the BW-3 segment adjacent to the Belden mine buildings as a potential source of 95 lbs/day zinc because of elevated zinc concentrations in groundwater and higher permeability in that area. Groundwater impacts were attributed to mine water because storm water and snow melt samples exhibited some alkalinity and very low metal concentrations, in contrast to the groundwater that contained no alkalinity and elevated zinc concentrations.

Preliminary Data Interpretation Report No. 3 – Belden Storm Event/Snowmelt Surface Water Runoff Monitoring (Dames & Moore 1996b) – The PDIR presents continuous recording stream gage measurements for stations E-3, E-5 and E-11. Chemical data and rainfall measurements are presented for nine rainfall-runoff events occurring between August 1995 and September 1996 at river and tributary stations in Belden and Rock Creek. Seven snowmelt-runoff events were sampled in 1996. Before the onset of high flow in May, the data illustrate a steady increase in zinc concentrations between river stations E-3 and E-11. While zinc concentrations were elevated in some of the tributaries during certain events, only small loads were generated because the relative discharges were small and of short duration. The highest zinc loads (in pounds per event) were measured in Rock Creek tributary SR-4 (WR-8 hillside) and its receiving stream, Rock Creek (T-6).

Remediation Feasibility Study, Bolts Lake Area and Areas Within OU-1 of the Eagle Mine Site (ERM 2007a) – Alternative 7 in this study prepared for CDPHE and EPA is an interceptor trench, pumping and water treatment system designed to reducing annual metal loading to the river from groundwater within Rex Flats and the OTP.

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APPENDIX A

EXCERPT OF THE BASIS AND PURPOSE OF THE EAGLE

MINE, EAGLE RIVER BASIN METALS STANDARDS OR WATER QUALITY STANDARDS (WQS)

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Excerpt of the Basis and Purpose of the Eagle Mine, Eagle River Basin — Metals Standards

[referred to in the Focused Feasibility Study as Water Quality Standards (WQS)]

The following is an excerpt from the 33.44 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; JUNE 2008 RULEMAKING; FINAL ACTION AUGUST 11, 2008; EFFECTIVE DATE JANUARY 1, 2009. This excerpt is Section T of the Basis and Purpose and begins of the bottom of Page 109 and continues through Page 111. The text has been extracted from the Statement of Basis in its entirety and presented here for informational purposes only. The information in this text is the basis for Table 1.

T. Eagle Mine, Eagle River Basin—Metals Standards

The Hazardous Materials and Waste Management Division and USEPA Superfund Program (Superfund Proponents) proposed site-specific zinc, copper and cadmium standards for segments on the Eagle River within the Eagle Mine Superfund Site. Similarly, CBS Operations Inc (CBS) (formerly Viacom International Inc) proposed a different set of site-specific zinc, copper and cadmium standards for segments on the Eagle River within the Eagle Mine Superfund Site.

After review of the evidence submitted, the Commission adopted the Superfund Proponents’ modified proposal for site-specific standards for the Eagle River Segments 5a, 5b, 5c and 7b as described below. These segments are impacted by historical mining activities at the Eagle Mine Superfund Site.

Zinc: A recalculation procedure was used for the aquatic species expected to occur in these segments of the Eagle River. After extensive review of available biological data and toxicity information, the recalculation was based on the following four most sensitive species that are expected to occur in these segments of the Eagle River: Cottus bairdi (Mottled Sculpin), Oncorhynchus (Rainbow and Cutthroat Trout), Salmo trutta (Brown Trout) and Ranatra elongata (Water Scorpion). The resulting site-specific recalculated hardness-based equations are:

Acute = 0.978*e 0.8537[ln(hardness)]+1.4189 Chronic = 0.986*e 0.8537[ln(hardness)]+1.2481

Because these equations rely on Sculpin as the most sensitive species, they are referred to as “sculpin equations.” An attainability analysis was conducted which showed that it is not feasible to achieve a level of cleanup that would result in attainment of the sculpin equations in Segments 5a, 5b and 7b on a year-round basis. Additional remediation projects have been identified that can be performed at the site. The analysis shows that the identified remediation projects can be expected to result in additional zinc load reduction during March and April, when metals’ loading is at its peak. When compared with the species toxicity information, it is clear that the feasible reductions still result in zinc levels that would exceed the standards based on the sculpin equation at some locations during some months. A modified species list without sculpin provided an equation that is based on the following four most sensitive species: Oncorhynchus (Rainbow and Cutthroat Trout), Salmo trutta (Brown Trout), Ranatra elongata (Water Scorpion) and Limnodrilus hoffmeisteri (Worm). The resulting recalculated hardness-based equations are:

Acute = 0.978*e 0.8537[ln(hardness)]+2.1302 Chronic = 0.986*e 0.8537[ln(hardness)]+1.9593

Because these equations rely on rainbow trout as the most sensitive species, they are referred to as “rainbow equations.”

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The biological goal for the Eagle Mine Superfund Site is a healthy brown trout fishery. Concurrent biological and water quality monitoring has shown that to achieve that goal, zinc must be maintained at levels better than those indicated by laboratory-based zinc toxicity studies with brown trout, probably because of combined effects with copper. On-going monitoring suggests that zinc and copper levels currently achieved by the cleanup are too high in March and April to maintain a healthy brown trout population. The equations based on a modified species list (rainbow equations) are incrementally more stringent than the equations based on brown trout and, at this site, offer a way to address this uncertainty and provide an adequate buffer for brown trout. These levels cannot be attained without additional remediation at the Eagle Mine Superfund Site.

The equations which represent the highest attainable water quality were applied by the Commission when and where the attainability analysis indicated they could be met. The rainbow equations were applied by the Commission to Segments 5a year-round and to segments 5b and 7b from January 1 through April 30. The sculpin equations were applied by the Commission to segment 5c year-round and to segments 5b and 7b from May 1 through December 31.

Copper: Similar to zinc, a recalculation procedure was conducted based on the species that are expected to occur at the site. The resulting species list includes the following as the four most sensitive species: Ephoron virgo (Mayfly), Tubifex tubifex (Worm), Plumatella emarginata (Bryozoan), and Oncorhynchus (Rainbow and Cutthroat Trout). The resulting recalculated hardness-based equations are:

Acute = 0.96*e 0.9801[ln(hardness)]-1.5865 Chronic = 0.96*e 0.5897[ln(hardness)]-0.4845

Because these equations rely on Ephoron virgo as the most sensitive species, they are referred to as “Ephoron equations.” These recalculated copper standards are attainable and were applied to Segments 5b, 5c and 7b.

For Segment 5a, an attainability analysis was conducted which showed that it is not feasible to reduce copper loads to a level that would result in attainment of the Ephoron equations. The majority of the copper load originates from upstream sources that cannot be controlled at the site. A modified species list, without Ephoron provided an equation that is based on the following four most sensitive species: Tubifex tubifex (Worm), Plumatella emarginata (Bryzoan), Oncorhynchus (Rainbow and Cutthroat Trout and Lumbriculus variegatus (Worm). The resulting modified hardness-based equations are:

Acute=0.96*e 0.9801[ln(hardness)] – 1.1073 Chronic=0.96*e 0.5897[ln(hardness)] – 0.0053

Because these equations rely on tubifex worms as the most sensitive species, they are referred to as “tubifex equations.” The tubifex equations were applied to Segment 5a.

Cadmium: The Commission had previously established an acute cadmium equation “with trout” in Regulation 31. That standard already applies to Segments 5a, 5b, 5c and 7b and continues to be appropriate and attainable. Therefore, no changes were made to the acute cadmium standard. However, using a revised acute/chronic ratio that was previously approved by both EPA and the Colorado Division of Wildlife for the Arkansas River and adopted by the Commission, a revised chronic cadmium equation was derived, as follows:

Chronic = (1.101672-[(ln(hardness)*(0.041838)])* e(0.7998 [ln hardness)]-3.1725)

This site-specific chronic Cadmium equation was applied to Segments 5a, 5b, 5c and 7b.

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APPENDIX B

SURFACE WATER SAMPLING 2009 – 2012

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Shaded and bolded concentration exceeds WQS as calculated based on the sampling date's measured hardnessU - Undetected at stated detection limit or ND - detection limit unknownJ - Estimated concentration, NM - not measured, NR - not reported 1 of 6

APPENDIX B SURFACE WATER SAMPLING 2009 - 2012

SITE_ID SAMPLING LOCATION SAMPLING DATESpec_ Cond_ Field @25C

Hardness (mg/l)

Cadmium Dissolved

(mg/l)

Copper Dissolved

(mg/l)

ZincDissolved

(mg/l) Source

E- 3 EAGLE RIVER ABOVE BELDEN 2/19/2009 157 97 0.0005 U 0.00116 J 0.01 CBSE- 3 EAGLE RIVER ABOVE BELDEN 3/11/2009 168 99 0.000669 0.00343 J 0.0357 CBSE- 3 EAGLE RIVER ABOVE BELDEN 3/20/2009 155 77 0.0004 J 0.00798 0.0825 CBSE- 3 EAGLE RIVER ABOVE BELDEN 3/25/2009 178 73 0.0005 U 0.0053 J 0.093 CBSE- 3 EAGLE RIVER ABOVE BELDEN 4/8/2009 101 68 0.0005 U 0.00643 J 0.127 CBSE- 3 EAGLE RIVER ABOVE BELDEN 4/20/2009 181 64 0.000622 0.00606 J 0.089 CBSE- 3 EAGLE RIVER ABOVE BELDEN 9/23/2009 142 82 0.0005 U 0.00114 J 0.00858 J CBSE- 3 EAGLE RIVER ABOVE BELDEN 4/15/2010 118 43 0.00012 0.0057 0.0433 CBSE- 3 EAGLE RIVER ABOVE BELDEN 9/24/2010 171 91 0.0001 U 0.002 U 0.01 CBSE- 3 EAGLE RIVER ABOVE BELDEN 3/21/2011 NM 79 0.0004 0.0084 0.0974 CBSE- 3 EAGLE RIVER ABOVE BELDEN 4/4/2011 154 65 0.00033 0.0074 0.105 CBSE- 3 EAGLE RIVER ABOVE BELDEN 4/18/2011 154 62 0.00022 0.005 0.0947 CBSE- 3 EAGLE RIVER ABOVE BELDEN 5/4/2011 141 69 0.0055 0.0095 0.0825 CBSE- 3 EAGLE RIVER ABOVE BELDEN 10/11/2011 174 81 0.0001 U 0.002 U 0.01 U CBSE- 3 EAGLE RIVER ABOVE BELDEN 3/12/2012 205 92 0.0001 U 0.0025 0.0259 CBSE- 3 EAGLE RIVER ABOVE BELDEN 3/26/2012 70 57 0.0001 U 0.0026 0.025 CBSE- 3 EAGLE RIVER ABOVE BELDEN 4/10/2012 94 42 0.0001 U 0.0027 0.0289 CBSE- 3 EAGLE RIVER ABOVE BELDEN 10/18/2012 146 75 0.0001 U 0.002 U 0.01 U CBS

E-10 EAGLE RIVER ABOVE ROCK CREEK 1/8/2009 219 98 0.000489 J 0.00184 J 0.0629 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 2/19/2009 150 86 0.0005 U 0.0026 J 0.14 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/11/2009 153 79 0.00077 0.00702 J 0.292 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/20/2009 138 77 0.000962 0.00784 0.304 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/25/2009 177 72 0.000999 0.007 J 0.349 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/8/2009 102 72 0.00058 0.00754 J 0.328 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/20/2009 178 64 0.00107 0.00887 J 0.299 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 9/23/2009 137 73 0.0005 U 0.00286 0.0658 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/6/2010 178 97 0.00041 0.004 0.167 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/17/2010 184 93 0.0011 0.0034 0.405 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/2/2010 166 80 0.00031 0.0042 0.132 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/15/2010 122 55 0.00041 0.0074 0.186 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 9/24/2010 164 87 0.00016 0.0031 0.07 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/7/2011 161 82 0.00042 0.0031 0.159 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/21/2011 148 79 0.0014 0.0085 0.462 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/4/2011 154 68 0.00097 0.0082 0.341 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/18/2011 136 61 0.00078 0.0076 0.27 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 5/4/2011 141 68 0.0011 0.0091 0.282 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 10/11/2011 165 74 0.00016 0.002 0.0594 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/12/2012 208 91 0.00049 0.0033 0.23 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 3/26/2012 60 56 0.00035 0.0033 0.131 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 4/10/2012 97 41 0.0001 0.0029 0.04 CBSE-10 EAGLE RIVER ABOVE ROCK CREEK 10/18/2012 134 67 0.00014 0.002 U 0.0474 CBS

E-12A EAGLE RIVER BELOW OLD TAILINGS 1/8/2009 203 103 0.00048 J 0.00134 J 0.1 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 2/19/2009 264 106 0.0005 U 0.00159 J 0.209 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/11/2009 161 95 0.000773 0.00432 J 0.417 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/13/2009 NR NR 0.0009 0.0072 0.3905 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 3/20/2009 150 88 0.000943 0.00568 0.346 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/25/2009 186 79 0.000817 0.00626 J 0.369 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/8/2009 131 93 0.000958 0.00762 J 0.432 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/20/2009 284 72 0.00138 0.00857 J 0.325 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/21/2009 NR 65 0.00091 0.0099 0.3281 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 5/22/2009 NR 46 ND 0.0037 0.022 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 6/23/2009 NR 56 ND NR 0.0185 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 7/21/2009 NR 68 ND 0.002 ND RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 8/25/2009 NR 82 0.00018 0.0032 0.077 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 9/23/2009 143 76 0.0005 U 0.00276 0.102 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 9/28/2009 NR 90 0.00019 0.0032 0.0893 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 10/26/2009 NR 86 0.0003 0.0039 0.1589 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 3/6/2010 178 103 0.00033 0.0031 0.198 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/17/2010 217 101 0.00037 0.0025 0.243 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/2/2010 185 84 0.0005 0.0036 0.248 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/15/2010 144 67 0.00065 0.0072 0.281 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 7/19/2010 NR 74 ND 0.0045 0.071 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 8/13/2010 NR 66 ND 0.0038 0.0746 RiverWatch

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Shaded and bolded concentration exceeds WQS as calculated based on the sampling date's measured hardnessU - Undetected at stated detection limit or ND - detection limit unknownJ - Estimated concentration, NM - not measured, NR - not reported 2 of 6

APPENDIX B SURFACE WATER SAMPLING 2009 - 2012

SITE_ID SAMPLING LOCATION SAMPLING DATESpec_ Cond_ Field @25C

Hardness (mg/l)

Cadmium Dissolved

(mg/l)

Copper Dissolved

(mg/l)

ZincDissolved

(mg/l) Source

E-12A EAGLE RIVER BELOW OLD TAILINGS 9/24/2010 173 94 0.00019 0.0023 0.103 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 1/17/2011 NR 80 NR 0.01 0.14 ERW&SE-12A EAGLE RIVER BELOW OLD TAILINGS 2/16/2011 NR 90 ND 0.0016 0.1782 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 3/7/2011 196 88 0.00045 0.0032 0.206 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/21/2011 175 89 0.0013 0.0068 0.513 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/28/2011 NR 82 0.00107 0.0038 0.4317 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 4/4/2011 197 87 0.0019 0.0084 0.674 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/18/2011 148 69 0.001 0.0106 0.364 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/22/2011 NR 68 0.00127 0.0114 0.421 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 5/4/2011 168 75 0.0015 0.0093 0.337 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 5/31/2011 NR 54 ND 0.004 0.0483 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 6/15/2011 NR 42 ND ND 0.0179 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 7/20/2011 NR 46 ND ND 0.02 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 8/17/2011 NR 62 ND ND 0.0527 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 9/21/2011 NR 71 ND ND 0.0849 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 10/11/2011 169 78 0.00025 0.002 U 0.0993 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 10/19/2011 NR 90 0.00022 ND 0.0997 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 11/17/2011 NR 92.5 0.0003 ND 0.185 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 12/14/2011 NR 96 0.0004 ND 0.1385 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 1/18/2012 NR 90 0.00029 ND 0.1442 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 2/15/2012 NR 98 0.00027 ND 0.1412 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 3/12/2012 235 100 0.00061 0.0026 0.316 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/19/2012 188.1 81 0.00045 0.0036 0.245 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 3/19/2012 NR NR 0.00052 0.0036 0.2283 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 3/26/2012 80 69 0.00044 0.0041 0.158 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/3/2012 65 64 0.00036 0.0043 0.178 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/10/2012 105 43 0.00014 0.0028 0.0642 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 4/11/2012 NR 78 ND ND 0.08 ERW&S/RWE-12A EAGLE RIVER BELOW OLD TAILINGS 4/17/2012 NR 59 0.00022 0.0034 0.117 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 5/16/2012 NR 78 ND ND 0.026 ERW&S/RWE-12A EAGLE RIVER BELOW OLD TAILINGS 6/27/2012 NR 32 ND ND 0.0461 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 7/24/2012 NR 60 NR ND 0.08 ERW&SE-12A EAGLE RIVER BELOW OLD TAILINGS 8/15/2012 NR 56 ND ND 0.0563 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 9/13/2012 NR 54 ND ND 0.0634 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 10/11/2012 NR 102 0.00053 ND 0.1955 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 10/18/2012 162 80 0.00018 0.002 U 0.0954 CBSE-12A EAGLE RIVER BELOW OLD TAILINGS 11/17/2011 NR 94 0.00038 ND 0.1385 RiverWatchE-12A EAGLE RIVER BELOW OLD TAILINGS 12/14/2011 NR 80 NR ND 0.14 ERW&S

E-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/4/2010 NR 98 0.0003 0.002 U 0.162 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/6/2010 NR 109 0.0003 0.0025 0.301 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/11/2010 NR 94 0.0002 0.0046 0.155 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/15/2010 278 101 0.0002 0.0034 0.156 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/18/2010 233 97 0.0002 0.0036 0.162 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/20/2010 NR 98 0.0003 0.0026 0.184 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/22/2010 232 100 0.0001 U 0.0035 0.206 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/25/2010 225 99 0.0001 U 0.0038 0.19 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/27/2010 230 97 0.0002 0.0039 0.149 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 2/3/2010 235 101 0.0003 0.0061 0.229 ERWSDE-13 EAGLE RIVER ABOVE TWO ELK CREEK 7/19/2010 NR 58 ND 0.0038 0.0559 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 8/13/2010 NR 94 ND 0.0036 0.0674 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 9/10/2010 NR 114 0.0002 0.0033 0.0928 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 10/13/2010 NR 130 0.00018 NR NR RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 11/22/2010 NR 120 0.00023 0.0013 0.1339 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/17/2011 NR 140 NR 0.01 0.13 ERW&SE-13 EAGLE RIVER ABOVE TWO ELK CREEK 2/16/2011 NR 152 ND 0.0013 0.1468 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 3/28/2011 NR 138 0.00138 0.0035 0.3962 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 4/22/2011 NR 90 0.00137 0.0113 0.3559 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 5/31/2011 NR 56 ND 0.0038 0.0495 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 6/15/2011 NR 50 ND ND 0.0175 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 7/20/2011 NR 52 ND ND 0.0193 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 8/17/2011 NR 94 ND ND 0.0532 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 9/21/2011 NR 124 0.00028 0.0022 0.0703 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 10/19/2011 NR 158 0.00026 ND 0.0903 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 11/17/2011 NR 143 0.0003 ND 0.1629 RiverWatch

Page 165: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Shaded and bolded concentration exceeds WQS as calculated based on the sampling date's measured hardnessU - Undetected at stated detection limit or ND - detection limit unknownJ - Estimated concentration, NM - not measured, NR - not reported 3 of 6

APPENDIX B SURFACE WATER SAMPLING 2009 - 2012

SITE_ID SAMPLING LOCATION SAMPLING DATESpec_ Cond_ Field @25C

Hardness (mg/l)

Cadmium Dissolved

(mg/l)

Copper Dissolved

(mg/l)

ZincDissolved

(mg/l) Source

E-13 EAGLE RIVER ABOVE TWO ELK CREEK 12/14/2011 NR 162 0.00037 ND 0.1347 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 1/18/2012 NR 172 0.00025 ND 0.1228 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 2/15/2012 NR 156 0.00025 ND 0.1274 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 3/19/2012 NR 84 0.00051 0.0033 0.2174 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 4/11/2012 NR 76 0.00023 0.0024 0.0662 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 5/15/2012 NR 64 ND ND 0.0249 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 6/27/2012 NR 70 ND ND 0.0471 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 7/24/2012 NR 106 NR ND 0.04 ERW&SE-13 EAGLE RIVER ABOVE TWO ELK CREEK 8/15/2012 NR 118 0.00022 ND 0.0504 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 9/13/2012 NR 128 ND ND 0.0577 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 10/11/2012 NR 170 0.00054 ND 0.1806 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 11/15/2012 NR 172 0.00027 ND 0.1159 RiverWatchE-13 EAGLE RIVER ABOVE TWO ELK CREEK 12/14/2012 NR 202 NR ND 0.12 ERW&S

E-13A EAGLE RIVER BELOW TWO ELK CREEK 2/19/2009 NR 101 0.0004 0.002 U 0.19 ERWSDE-13A EAGLE RIVER BELOW TWO ELK CREEK 3/11/2009 NR 140 0.0003 0.0055 0.217 ERWSDE-13A EAGLE RIVER BELOW TWO ELK CREEK 3/25/2009 385 120 0.0004 0.0051 0.181 ERWSD

E-15 EAGLE RIVER BELOW CROSS CREEK 2/19/2009 355 140 0.0005 U 0.00153 J 0.183 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 3/11/2009 200 182 0.000561 0.00254 J 0.308 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 3/25/2009 232 104 0.000763 0.0052 J 0.287 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/8/2009 146 111 0.000436 J 0.0053 J 0.317 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/20/2009 220 80 0.00122 0.00614 J 0.249 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 9/23/2009 152 81 0.0005 U 0.00209 0.0656 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 12/30/2009 267 135 0.000392 J 0.00206 0.193 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 12/31/2009 NM 106 0.00034 0.0027 0.182 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/2/2010 359 131 0.00033 0.002 0.208 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/3/2010 219 103 0.0003 0.0022 0.18 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/4/2010 224 101 0.00023 0.002 U 0.168 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/5/2010 440 102 0.00021 0.002 U 0.16 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/6/2010 NM 143 0.00026 0.002 U 0.198 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/7/2010 NM 109 0.00022 0.002 U 0.204 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/8/2010 234 108 0.00027 0.002 U 0.222 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/9/2010 231 109 0.0002 0.002 U 0.176 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/10/2010 NM 110 0.00019 0.002 U 0.174 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/11/2010 234 110 0.00025 0.002 U 0.188 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/12/2010 302 122 0.00024 0.002 0.194 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/13/2010 232 110 0.00021 0.002 U 0.184 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/14/2010 221 105 0.00018 0.002 U 0.182 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/15/2010 380 141 0.00032 0.0021 0.205 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/16/2010 211 109 0.00016 0.002 U 0.169 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/17/2010 235 108 0.00011 0.002 U 0.161 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/18/2010 394 108 0.00015 0.002 U 0.167 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/19/2010 232 111 0.00015 0.002 U 0.174 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/20/2010 218 115 0.00014 0.002 U 0.172 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/21/2010 213 109 0.00019 0.002 0.157 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/22/2010 215 109 0.00019 0.002 U 0.165 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/23/2010 210 116 0.00016 0.002 U 0.18 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 1/24/2010 227 114 0.00017 0.002 U 0.168 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 3/6/2010 285 142 0.0002 0.0021 0.169 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 3/17/2010 291 149 0.00016 0.002 U 0.178 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/2/2010 250 125 0.0003 0.0023 0.195 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/15/2010 136 62 0.00053 0.0055 0.187 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 7/19/2010 NR 80 ND 0.0025 0.0398 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 8/13/2010 NR 72 ND 0.0036 0.0459 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 9/10/2010 NR 116 ND 0.0034 0.0749 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 9/24/2010 151 93 0.00039 0.0022 0.0803 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 10/13/2010 NR 115 ND 0.0012 0.0813 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 11/22/2010 NR 106 ND 0.0012 0.1033 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 1/17/2011 NR 174 NR 0.01 0.12 ERW&SE-15 EAGLE RIVER BELOW CROSS CREEK 2/16/2011 NR 130 ND 0.0011 0.124 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 3/7/2011 212 129 0.00031 0.0072 0.197 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 3/21/2011 NM 118 0.00092 0.0059 0.4 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 3/28/2011 NR 114 0.00065 0.0034 0.2948 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 4/4/2011 212 94 0.0015 0.0123 0.589 CBS

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Shaded and bolded concentration exceeds WQS as calculated based on the sampling date's measured hardnessU - Undetected at stated detection limit or ND - detection limit unknownJ - Estimated concentration, NM - not measured, NR - not reported 4 of 6

APPENDIX B SURFACE WATER SAMPLING 2009 - 2012

SITE_ID SAMPLING LOCATION SAMPLING DATESpec_ Cond_ Field @25C

Hardness (mg/l)

Cadmium Dissolved

(mg/l)

Copper Dissolved

(mg/l)

ZincDissolved

(mg/l) Source

E-15 EAGLE RIVER BELOW CROSS CREEK 4/18/2011 210 85 0.00078 0.0068 0.291 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/22/2011 NR 70 0.00083 0.0093 0.2969 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 5/4/2011 185 85 0.00074 0.006 0.215 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 5/31/2011 NR 56 ND 0.0029 0.0362 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 6/15/2011 NR 40 ND ND 0.0102 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 7/20/2011 NR 36 ND ND 0.0118 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 8/17/2011 NR 76 ND ND 0.0399 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 9/21/2011 NR 82 ND ND 0.07 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 10/11/2011 236 107 0.00021 0.002 U 0.0973 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 10/19/2011 NR 108 ND 0.0022 0.077 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 11/17/2011 NR 168 0.00021 ND 0.111 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 11/17/2011 NR 154 0.00028 ND 0.0984 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 12/14/2011 NR 140 0.00033 ND 0.1242 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 12/14/2011 NR 190 NR ND 0.11 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 1/18/2012 NR 162 0.0002 ND 0.1214 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 2/15/2012 NR 126 ND ND 0.1152 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 3/19/2012 NR 87 0.00038 0.0027 0.1723 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 3/26/2012 95 88 0.00027 0.0031 0.12 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/10/2012 143 54 0.0001 U 0.0027 0.055 CBSE-15 EAGLE RIVER BELOW CROSS CREEK 4/11/2012 NR 76 NR ND 0.07 ERW&SE-15 EAGLE RIVER BELOW CROSS CREEK 5/16/2012 NR 64 ND 0.0024 0.0181 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 6/27/2012 NR 46 ND ND 0.0275 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 7/24/2012 NR 78 NR ND 0.07 ERW&SE-15 EAGLE RIVER BELOW CROSS CREEK 8/15/2012 NR 70 ND ND 0.0312 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 9/13/2012 NR 98 ND ND 0.0462 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 10/11/2012 NR 130 0.00033 ND 0.1218 RiverWatchE-15 EAGLE RIVER BELOW CROSS CREEK 10/18/2012 157 80 0.00015 0.002 U 0.0568 CBS

E-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/14/2009 288 128 0.0001 0.0008 0.08 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 2/11/2009 324 146 0.0002 0.00001 U 0.13 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/3/2009 309 128 0.001 U 0.01 U 0.17 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/10/2009 370 175 0.0004 0.0022 0.18 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/17/2009 301 133 0.0003 0.0027 0.159 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/24/2009 258 115 0.0006 0.0053 0.269 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/7/2009 304 128 0.0005 0.0065 0.231 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/14/2009 213 88 0.0005 0.0057 0.213 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/21/2009 192 83 0.0003 0.0049 0.131 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/28/2009 160 67 0.0004 0.0066 0.121 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/12/2009 126 58 0.0001 U 0.0045 0.038 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 6/9/2009 128 65 0.0001 U 0.0034 0.019 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 7/14/2009 115 51 0.0001 U 0.0016 0.084 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 8/11/2009 180 88 0.0001 U 0.002 0.043 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 9/16/2009 246 116 0.0001 0.0019 0.061 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 10/13/2009 218 97 0.0001 U 0.002 0.058 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 11/10/2009 248 109 0.0002 0.0019 0.091 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 12/8/2009 281 136 0.0002 0.0013 0.142 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 12/31/2009 NR 122 0.0002 0.002 U 0.122 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/4/2010 NR 122 0.0002 0.002 U 0.117 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/6/2010 NR 162 0.0002 0.0024 0.139 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/8/2010 NR 119 0.0001 0.0016 0.124 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/11/2010 NR 119 0.0001 0.0015 0.125 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/12/2010 285 131 0.0002 0.001 0.129 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/13/2010 433 132 0.0002 J 0.0028 0.13 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/15/2010 323 NR 0.0002 J 0.0038 J 0.111 J ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/18/2010 292 NR 0.0002 J 0.0025 J 0.121 J ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/20/2010 3.49 NR 0.0002 J 0.0038 J 0.139 J ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/22/2010 292 NR 0.0002 J 0.0012 J 0.148 J ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/25/2010 418 141 0.0001 U 0.0026 0.121 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/27/2010 440 132 0.0001 U 0.0019 0.092 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 2/3/2010 386 153 0.0002 0.0033 0.15 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 2/9/2010 355 161 0.0002 0.0021 0.139 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 2/20/2010 395 156 0.0003 0.0062 0.148 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 2/26/2010 373 158 0.0001 0.0034 0.138 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/5/2010 374 163 0.0003 0.0056 0.168 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/9/2010 314 157 0.0001 U 0.0025 0.16 ERWSD

Page 167: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Shaded and bolded concentration exceeds WQS as calculated based on the sampling date's measured hardnessU - Undetected at stated detection limit or ND - detection limit unknownJ - Estimated concentration, NM - not measured, NR - not reported 5 of 6

APPENDIX B SURFACE WATER SAMPLING 2009 - 2012

SITE_ID SAMPLING LOCATION SAMPLING DATESpec_ Cond_ Field @25C

Hardness (mg/l)

Cadmium Dissolved

(mg/l)

Copper Dissolved

(mg/l)

ZincDissolved

(mg/l) Source

E-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/18/2010 371 172 0.0002 0.0033 0.188 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/22/2010 387 186 0.0002 0.0028 0.179 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/26/2010 318 157 0.0003 0.0029 0.213 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/30/2010 335 154 0.0003 0.0038 0.198 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/1/2010 298 133 0.0003 0.0039 0.224 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/5/2010 323 142 0.0004 0.0037 0.222 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/7/2010 320 140 0.0003 0.0035 0.196 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/9/2010 305 140 0.0003 0.003 0.218 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/14/2010 195 80 0.0005 0.011 0.244 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/15/2010 178 76 0.0005 0.0053 0.188 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/16/2010 144.5 58 0.0003 0.006 0.132 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/21/2010 149 76 0.0003 0.0078 0.135 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/27/2010 169 62 0.0003 0.0062 0.11 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/4/2010 192 88 0.0004 0.0053 0.138 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/11/2010 155 70 0.0001 U 0.0069 0.093 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/18/2010 157 70 0.0001 U 0.007 0.099 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/25/2010 142 70 0.0001 U 0.0043 0.062 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 6/1/2010 132 51 0.001 0.0041 0.024 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 7/22/2010 182 91 0.0001 0.0024 0.045 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 8/19/2010 212 95 0.0001 U 0.0021 0.053 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 9/24/2010 242 102 0.0001 0.0034 0.08 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 10/28/2010 NR 104 0.0002 0.0031 0.085 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 11/9/2010 236 106 0.0001 0.0031 0.087 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 12/14/2010 269 124 0.0001 0.0018 0.096 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 1/11/2011 299 129 0.0002 0.0032 0.093 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 2/22/2011 339 166 0.0002 0.0031 0.162 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/1/2011 372 162 0.0002 0.002 0.156 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/8/2011 327 134 0.0001 0.0047 0.145 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/15/2011 303 136 0.0004 0.0044 0.203 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/22/2011 262.3 118 0.0008 0.008 0.358 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 3/29/2011 231 113 0.0007 0.0096 0.298 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/5/2011 202.2 122 0.0009 0.0083 0.371 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/12/2011 209.1 101 0.001 0.0101 0.357 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/19/2011 172.9 80 0.0008 0.01 0.291 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 4/26/2011 240.1 97 0.0009 0.0131 0.306 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/3/2011 226.9 106 0.0009 0.0099 0.272 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 5/10/2011 277.8 74 0.0004 0.009 0.129 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 6/14/2011 111 51 0.0001 U 0.0028 0.02 ERWSDE-22 EAGLE RIVER ABOVE DOWDS JUNCT. 7/12/2011 77 35 0.0004 0.0041 0.024 ERWSDE-22 10/18/2012 216 114 0.00017 0.002 U 0.0545 CBS

T-10 ROCK CREEK AT MOUTH 2/19/2009 642 362 0.00659 0.00175 J 4.45 CBST-10 ROCK CREEK AT MOUTH 3/11/2009 219 210 0.00296 0.00353 J 1.91 CBST-10 ROCK CREEK AT MOUTH 3/20/2009 301 178 0.00292 0.00281 1.22 CBST-10 ROCK CREEK AT MOUTH 3/25/2009 340 210 0.00342 0.00183 J 1.72 CBST-10 ROCK CREEK AT MOUTH 4/8/2009 176 165 0.00165 0.00289 J 1.16 CBST-10 ROCK CREEK AT MOUTH 4/20/2009 371 197 0.00582 0.0148 2.3 CBST-10 ROCK CREEK AT MOUTH 9/23/2009 277 218 0.00145 0.00371 0.897 CBST-10 ROCK CREEK AT MOUTH 3/6/2010 591 NM 0.0099 0.0078 5.45 CBST-10 ROCK CREEK AT MOUTH 3/17/2010 468 NM 0.0067 0.0068 3.65 CBST-10 ROCK CREEK AT MOUTH 4/2/2010 406 245 0.0072 0.0034 2.87 CBST-10 ROCK CREEK AT MOUTH 4/15/2010 570 305 0.0202 0.0301 8.52 CBST-10 ROCK CREEK AT MOUTH 9/24/2010 426 273 0.0022 0.0028 1.16 CBST-10 ROCK CREEK AT MOUTH 3/7/2011 874 354 0.0105 0.0119 4.01 CBST-10 ROCK CREEK AT MOUTH 3/21/2011 379 204 0.0054 0.0107 2.42 CBST-10 ROCK CREEK AT MOUTH 4/4/2011 488 184 0.0061 0.0174 2.79 CBST-10 ROCK CREEK AT MOUTH 4/18/2011 434 257 0.0115 0.037 4.85 CBST-10 ROCK CREEK AT MOUTH 5/4/2011 361 182 0.0038 0.0205 1.52 CBST-10 ROCK CREEK AT MOUTH 10/11/2011 608 299 0.0049 0.0039 2.56 CBST-10 ROCK CREEK AT MOUTH 3/12/2012 565 252 0.0031 0.0044 1.9 CBST-10 ROCK CREEK AT MOUTH 3/26/2012 350 437 0.0119 0.0225 6.22 CBST-10 ROCK CREEK AT MOUTH 4/10/2012 348 194 0.0046 0.0115 2.12 CBST-10 10/18/2012 421 313 0.0025 0.0026 1.53 CBS

Page 168: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Shaded and bolded concentration exceeds WQS as calculated based on the sampling date's measured hardnessU - Undetected at stated detection limit or ND - detection limit unknownJ - Estimated concentration, NM - not measured, NR - not reported 6 of 6

APPENDIX B SURFACE WATER SAMPLING 2009 - 2012

SITE_ID SAMPLING LOCATION SAMPLING DATESpec_ Cond_ Field @25C

Hardness (mg/l)

Cadmium Dissolved

(mg/l)

Copper Dissolved

(mg/l)

ZincDissolved

(mg/l) Source

T-18 CROSS CREEK NEAR MOUTH 3/11/2009 123 45 0.0005 U 0.0024 J 0.0896 CBST-18 CROSS CREEK NEAR MOUTH 3/25/2009 117 33 0.0005 U 0.00231 J 0.0571 CBST-18 CROSS CREEK NEAR MOUTH 4/8/2009 89.6 47 0.0005 U 0.0023 J 0.0738 CBST-18 CROSS CREEK NEAR MOUTH 4/20/2009 106 30 0.0005 U 0.0026 J 0.0479 CBST-18 CROSS CREEK NEAR MOUTH 9/23/2009 81.7 29 0.0005 U 0.00169 J 0.0491 CBST-18 CROSS CREEK NEAR MOUTH 3/6/2010 129 48 0.0001 U 0.002 U 0.154 CBST-18 CROSS CREEK NEAR MOUTH 3/17/2010 142 60 0.0001 U 0.002 U 0.184 CBST-18 CROSS CREEK NEAR MOUTH 4/2/2010 138 49 0.0001 U 0.0022 0.086 CBST-18 CROSS CREEK NEAR MOUTH 4/15/2010 96 31 0.0002 0.0036 0.0724 CBST-18 CROSS CREEK NEAR MOUTH 9/24/2010 97 33 0.00043 0.0057 0.123 CBST-18 CROSS CREEK NEAR MOUTH 3/7/2011 102 42 0.00015 0.0051 0.118 CBST-18 CROSS CREEK NEAR MOUTH 3/21/2011 111 48 0.00024 0.004 0.128 CBST-18 CROSS CREEK NEAR MOUTH 4/4/2011 121 48 0.0001 U 0.0041 0.104 CBST-18 CROSS CREEK NEAR MOUTH 4/18/2011 109 37 0.00018 0.0058 0.0763 CBST-18 CROSS CREEK NEAR MOUTH 5/4/2011 73 31 0.0001 U 0.0021 0.0546 CBST-18 CROSS CREEK NEAR MOUTH 10/11/2011 98 36 0.0002 0.0038 0.0901 CBST-18 CROSS CREEK NEAR MOUTH 3/12/2012 128 44 0.00016 0.002 U 0.173 CBST-18 CROSS CREEK NEAR MOUTH 3/26/2012 40 29 0.0001 U 0.0023 0.038 CBST-18 CROSS CREEK NEAR MOUTH 4/10/2012 64 20 0.0001 U 0.0028 0.0265 CBST-18 CROSS CREEK NEAR MOUTH 10/18/2012 94 40 0.0001 U 0.002 U 0.0567 CBSSource:CBS - Eagle River Mine Site consultants for CBS Operations Inc.ERWSD - Eagle River Water and Sand District as reported by the District or by Robert Weaver, Leonard Rice EngineersERW&S - Eagle River Water and Sand District testing in partnership with the Eagle River Watershed CouncilERW&S/RW - Eagle River Water and Sand District and RiverWatch testing in partnership with the Eagle River Watershed CouncilRiverWatch - River Watch of Colorado testing in partnership with the Eagle River Watershed Council

Page 169: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

APPENDIX C

ANNUAL LOADING AND LOAD REDUCTION

Page 170: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

APPENDIX C-1

YEARLY AVERAGE ZINC LOAD CALCULATIONS AND ZINC LOAD

REDUCTION CALCULATIONS

Page 171: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Appendix C-1Yearly Average Zinc Load Calculations by Station and Zinc Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

1/14/2005 0.9 14.5 0.0 13.6 39.8 0.0 13.7 44.6 0.0 21.8 46.8 0.0 20.4 44.7 0.0 18.8 47.1 0.0 19.5 64.7 0.0 21.2 69.3 0.0 27.6 29.8 0.0 0.02 3.3 9.7 0.0 0.0 0.03/3/2005 43.7 47.5 0.0 36.8 83.0 0.0 27.1 41.6 0.0 2.4 3.9 0.0 0.0 0.03/10/2005 43.7 55.8 0.0 44.4 83.8 0.0 39.9 45.7 0.0 2.7 4.1 0.0 0.0 0.03/17/2005 20.7 14.1 6.7 50.5 39.8 10.7 48.0 43.0 5.0 70.5 50.6 20.0 51.7 53.0 0.0 40.7 53.0 0.0 44.2 82.0 0.0 44.6 88.5 0.0 36.1 45.0 0.0 7.16 2.9 4.0 0.0 0.0 0.03/24/2005 38.9 49.8 0.0 42.1 76.4 0.0 35.5 42.1 0.0 2.5 4.1 0.0 0.0 0.03/31/2005 53.6 53.0 0.6 53.2 88.7 0.0 41.6 47.0 0.0 3.2 5.4 0.0 0.0 0.04/3/2005 59.8 51.4 52.8 0.04/4/2005 80.8 76.1 4.7 75.1 88.3 0.04/5/2005 18.2 24.5 0.0 56.2 74.0 0.04/12/2005 17.7 16.9 0.9 92.3 50.6 41.7 83.2 53.3 29.9 125.4 65.1 60.4 108.0 66.4 41.6 90.7 64.3 26.4 95.4 110.5 0.0 107.2 123.9 0.0 85.2 55.2 29.9 14.45 11.7 13.9 0.0 0.0 0.05/23/2005 365.4 245.4 120.0 207.6 706.6 0.0 187.6 694.5 0.0 215.7 719.3 0.0 214.0 699.7 0.0 175.1 326.8 0.0 199.4 412.4 0.0 200.7 487.1 0.0 200.7 634.7 0.0 14.02 17.6 52.6 0.0 0.0 0.06/28/2005 79.5 60.5 62.1 58.0 6.87/29/2005 30.0 27.7 24.9 24.7 1.88/25/2005 28.1 24.3 19.0 19.0 1.49/12/2005 2.5 19.7 0.0 18.8 56.4 0.0 22.4 59.8 0.0 24.7 59.5 0.0 26.7 58.6 0.0 23.2 28.5 0.0 24.2 44.1 0.0 20.0 37.3 0.0 16.5 41.5 0.0 6.06 1.4 5.1 0.0 0.0 0.09/22/2005 16.7 16.0 14.0 14.2 1.510/18/2005 1.7 21.5 0.0 28.1 61.6 0.0 27.9 65.8 0.0 33.3 60.8 0.0 35.0 66.4 0.0 32.4 32.7 0.0 36.1 51.8 0.0 37.2 62.2 0.0 33.4 64.4 0.0 1.47 2.4 8.7 0.0 0.0 0.010/25/2005 28.5 26.8 23.3 25.7 2.31/31/2006 1.8 14.7 0.0 13.8 43.7 0.0 30.0 50.3 0.0 30.6 45.7 0.0 28.4 70.3 0.0 30.1 78.9 0.0 25.4 41.9 0.0 5.40 2.3 5.3 0.0 0.0 0.03/9/2006 298.8 103.0 195.7 280.4 112.6 167.7 219.8 98.9 120.9 227.7 150.6 77.1 300.9 209.9 91.0 305.8 103.8 202.0 8.4 15.3 0.0 0.0 34.33/15/2006 107.4 68.8 38.6 97.4 70.8 26.6 101.8 68.0 33.8 110.3 97.0 13.3 2.9 5.7 0.03/16/2006 145.7 70.7 75.0 121.7 126.3 0.0 121.7 66.3 55.4 8.3 13.6 0.0 0.0 0.03/22/2006 105.8 63.7 42.1 103.9 65.1 38.8 101.9 64.5 37.4 108.5 100.9 7.7 3.0 6.1 0.03/23/2006 11.0 20.9 0.0 106.7 63.3 43.4 103.1 68.1 35.0 109.5 69.3 40.2 104.9 103.5 1.3 113.2 124.8 0.0 91.8 67.5 24.3 8.75 8.3 13.6 0.0 0.0 0.03/29/2006 130.8 68.1 62.7 124.0 73.5 50.5 117.3 70.1 47.2 117.8 104.4 13.4 5.5 9.0 0.03/30/2006 138.3 73.2 65.1 147.0 128.3 18.8 120.3 71.3 49.0 10.4 16.2 0.0 0.0 0.04/5/2006 267.8 155.5 112.3 264.3 152.2 112.2 240.3 156.6 83.7 267.5 211.2 56.3 8.6 17.9 0.04/6/2006 384.4 195.1 189.3 399.5 313.1 86.4 319.6 183.8 135.8 17.0 26.5 0.0 0.0 0.04/12/2006 288.4 240.3 48.1 281.6 219.3 62.3 313.8 232.1 81.7 338.5 309.5 29.0 6.2 22.1 0.04/13/2006 634.1 348.8 285.3 598.1 545.1 53.1 486.0 344.0 142.0 6.6 31.8 0.0 0.0 0.04/19/2006 343.6 334.8 8.8 388.8 345.0 43.8 388.8 340.8 48.0 383.4 443.9 0.0 4.2 21.7 0.04/20/2006 57.0 94.0 0.0 229.6 304.9 0.0 223.9 317.5 0.0 316.4 323.2 0.0 253.3 426.3 0.0 473.3 618.3 0.0 414.1 276.3 137.9 5.82 4.5 20.5 0.0 0.0 137.94/26/2006 305.8 430.4 0.0 283.7 438.8 0.0 300.3 417.3 0.0 303.8 547.8 0.0 4.7 25.2 0.05/22/2006 40.9 250.6 0.0 79.6 713.8 0.0 73.2 720.9 0.0 115.5 759.8 0.0 197.3 446.5 0.0 125.7 585.8 0.0 119.1 630.0 0.0 5.66 6.2 52.7 0.0 0.0 0.05/23/2006 246.7 745.2 0.0 274.7 781.3 0.0 292.7 360.7 0.0 317.9 445.5 0.0 10.0 187.0 0.09/27/2006 1.5 25.9 0.0 19.6 80.8 0.0 17.8 82.0 0.0 26.4 87.0 0.0 28.4 63.0 0.0 28.1 76.6 0.0 32.2 80.3 0.0 1.38 2.3 9.0 0.0 0.0 0.010/23/2006 1.7 22.7 0.0 40.2 68.3 0.0 33.8 71.6 0.0 36.7 74.9 0.0 45.8 61.6 0.0 47.4 78.2 0.0 39.3 80.9 0.0 4.08 5.6 7.8 0.0 0.0 0.01/29/2007 1.2 17.9 0.0 11.8 49.2 0.0 15.4 55.2 0.0 31.1 53.8 0.0 26.4 95.4 0.0 29.9 109.9 0.0 23.7 55.9 0.0 6.72 3.0 4.2 0.0 0.0 0.03/2/2007 14.7 32.5 0.0 17.6 55.3 0.0 13.8 30.3 0.0 2.1 3.4 0.0 0.0 0.03/13/2007 56.2 55.3 0.9 58.7 98.1 0.0 45.9 52.0 0.0 6.5 11.7 0.0 0.0 0.03/14/2007 47.5 62.0 0.0 62.2 66.7 0.0 2.263/20/2007 19.6 28.5 0.0 78.9 85.4 0.0 81.7 94.8 0.0 110.5 97.2 13.3 119.7 145.5 0.0 120.7 164.7 0.0 99.5 92.0 7.5 3.64 4.9 13.2 0.0 0.0 0.03/21/2007 47.7 79.7 0.0 64.5 87.6 0.0 3.253/27/2007 116.2 105.2 11.0 137.0 183.5 0.0 117.0 107.8 9.3 4.2 12.3 0.0 0.0 0.03/28/2007 74.8 104.7 0.0 99.6 109.3 0.0 5.974/3/2007 89.8 103.9 0.0 108.0 178.5 0.0 96.2 96.6 0.0 5.5 13.5 0.0 0.0 0.04/4/2007 57.9 99.4 0.0 75.5 106.3 0.0 4.424/10/2007 118.4 142.1 0.0 152.3 259.5 0.0 131.4 146.6 0.0 5.9 16.0 0.0 0.0 0.04/11/2007 73.7 119.7 0.0 96.2 137.1 0.0 0.314/17/2007 23.1 42.5 0.0 80.4 130.6 0.0 84.1 137.6 0.0 110.1 145.3 0.0 119.1 203.5 0.0 138.4 265.1 0.0 121.1 152.4 0.0 4.46 4.6 15.4 0.0 0.0 0.04/18/2007 91.1 164.8 0.0 118.8 169.3 0.0 4.314/24/2007 112.0 204.6 0.0 142.8 364.5 0.0 133.9 206.4 0.0 5.5 19.8 0.0 0.0 0.04/26/2007 89.1 185.6 0.0 105.4 193.2 0.0 5.229/25/2007 1.7 26.0 0.0 17.1 77.2 0.0 26.9 85.8 0.0 21.7 76.2 0.0 23.1 58.5 0.0 22.3 66.6 0.0 19.1 70.9 0.0 3.03 2.9 12.0 0.0 0.0 0.010/16/2007 2.1 25.2 0.0 15.6 72.3 0.0 15.2 76.1 0.0 18.1 72.1 0.0 22.3 53.4 0.0 21.9 59.9 0.0 18.0 67.2 0.0 2.88 2.2 6.9 0.0 0.0 0.01/28/2008 6.4 36.5 0.0 13.0 43.9 0.0 13.2 41.4 0.0 13.2 52.6 0.0 16.2 54.5 0.0 12.7 31.0 0.0 1.28 2.0 4.7 0.0 0.0 0.03/4/2008 37.0 41.9 0.0 29.2 70.3 0.0 22.8 39.6 0.0 2.2 5.6 0.0 0.0 0.03/11/2008 30.4 41.6 0.0 25.9 66.1 0.0 20.2 36.5 0.0 2.3 5.3 0.0 0.0 0.03/18/2008 28.8 40.9 0.0 32.4 71.9 0.0 26.4 37.6 0.0 2.5 5.3 0.0 0.0 0.03/25/2008 3.2 14.6 0.0 58.2 44.4 13.8 46.8 49.2 0.0 42.8 49.7 0.0 40.6 72.1 0.0 41.8 79.8 0.0 32.5 44.2 0.0 2.42 2.3 5.9 0.0 0.0 0.04/2/2008 87.1 52.7 34.44/8/2008 134.3 57.1 77.1 148.3 106.5 41.8 110.2 56.8 53.4 4.0 8.0 0.0 0.0 0.04/9/2008 140.5 53.8 86.74/15/2008 337.7 112.6 225.1 385.5 198.1 187.5 256.5 117.3 139.2 7.6 15.2 0.0 0.0 0.04/16/2008 333.7 118.3 215.44/22/2008 125.2 55.9 69.3 661.5 179.7 481.8 653.8 185.4 468.4 653.4 198.7 454.7 692.3 273.5 418.8 740.6 340.8 399.8 646.5 196.2 450.3 3.37 8.3 21.5 0.0 0.0 0.04/23/2008 509.7 246.0 263.74/29/2008 399.7 216.4 183.3 507.0 387.5 119.5 411.2 222.3 188.9 18.4 20.0 0.0 0.0 5.65/1/2008 322.2 370.8 0.05/28/2008 26.9 264.6 0.0 88.9 805.1 0.0 106.5 844.0 0.0 168.0 843.0 0.0 173.4 843.8 0.0 193.2 414.4 0.0 203.2 689.9 0.0 12.96 11.2 52.6 0.0 0.06/24/2008 23.5 302.0 0.0 55.8 919.2 0.0 73.1 916.8 0.0 78.8 930.1 0.0 91.4 916.9 0.0 82.2 450.2 0.0 94.3 656.3 0.0 7.25 9.2 56.3 0.0 0.07/29/2008 5.9 77.3 0.0 14.8 238.4 0.0 18.8 231.1 0.0 25.0 229.3 0.0 30.3 235.2 0.0 28.8 113.0 0.0 34.2 182.9 0.0 4.41 4.2 24.2 0.0 0.08/26/2008 2.0 33.8 0.0 14.1 100.3 0.0 15.7 104.5 0.0 1.36 2.8 8.9 0.08/27/2008 22.2 98.2 0.0 23.7 99.8 0.0 18.7 49.0 0.0 22.8 84.2 0.0 0.09/17/2008 1.0 23.1 0.0 6.4 69.0 0.0 10.8 71.0 0.0 1.12 3.2 4.7 0.09/18/2008 17.7 77.6 0.0 18.8 76.7 0.0 15.9 36.6 0.0 16.6 67.0 0.0 0.09/29/2008 2.9 17.7 0.0 12.0 52.2 0.0 12.1 55.5 0.0 20.6 57.6 0.0 21.7 43.6 0.0 19.4 47.3 0.0 11.5 50.3 0.0 0.38 5.2 4.9 0.3 0.0 0.010/20/2008 0.7 18.2 0.0 9.5 52.2 0.0 11.3 57.5 0.0 16.4 58.5 0.0 15.1 45.3 0.0 17.6 46.8 0.0 15.5 48.5 0.0 0.32 5.9 4.7 1.1 0.0 0.010/21/2008 1.0 20.6 0.0 5.5 59.8 0.0 11.0 64.3 0.0 1.15 4.0 4.2 0.010/22/2008 16.2 64.9 0.0 18.2 63.8 0.0 17.4 31.3 0.0 20.2 53.0 0.0 0.010/29/2008 22.0 65.4 0.011/11/2008 20.4 52.0 0.012/9/2008 15.9 46.9 0.01/8/2009 11.4 63.7 0.0 17.3 63.2 0.01/14/2009 17.7 48.0 0.02/11/2009 24.0 44.6 0.02/19/2009 1.1 13.3 0.0 18.6 41.8 0.0 26.0 46.5 0.0 28.6 74.3 0.0 0.96 0.03/3/2009 34.5 43.9 0.03/10/2009 33.2 52.1 0.03/11/2009 4.3 14.7 0.0 42.0 42.0 0.1 56.3 46.1 10.2 53.9 104.1 0.0 2.32 3.8 7.6 0.0 0.0 0.03/17/2009 33.8 47.5 0.03/20/2009 15.7 19.0 0.0 68.3 64.1 4.2 74.7 69.1 5.7 1.983/24/2009 112.5 82.6 30.03/25/2009 20.9 21.3 0.0 91.6 70.7 20.9 93.7 74.0 19.6 109.3 140.5 0.0 3.72 4.6 11.2 0.0 0.0 10.44/7/2009 70.7 66.2 4.5

Reduction Beyond 5a

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Appendix C-1Yearly Average Zinc Load Calculations by Station and Zinc Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

Reduction Beyond 5a

4/8/2009 32.7 23.1 9.7 98.5 80.9 17.6 126.0 97.7 28.2 141.5 174.1 0.0 4.38 5.6 14.2 0.0 0.0 0.04/14/2009 150.9 111.2 39.74/20/2009 38.7 36.9 1.8 149.4 121.7 27.7 159.7 132.4 27.3 197.4 233.7 0.0 3.73 5.7 15.2 0.0 0.0 12.34/21/2009 150.4 171.5 0.04/28/2009 247.7 254.7 0.05/12/2009 178.4 516.5 0.06/9/2009 98.6 629.4 0.07/14/2009 119.3 139.9 0.08/11/2009 21.6 78.9 0.09/16/2009 21.5 70.1 0.09/23/2009 1.9 23.5 0.0 17.3 71.6 0.0 25.9 71.6 0.0 25.0 55.7 0.0 1.11 2.2 2.7 0.0 0.010/13/2009 15.6 45.8 0.011/10/2009 19.3 40.0 0.012/8/2009 30.2 48.4 0.012/30/2009 37.4 43.8 0.012/31/2009 26.6 24.7 1.9 28.4 28.8 0.0 19.1 32.4 0.01/2/2010 36.4 78.6 0.01/3/2010 26.5 53.7 0.01/4/2010 17.5 38.2 0.0 21.5 46.1 0.0 15.0 26.6 0.01/5/2010 23.5 53.3 0.01/6/2010 42.3 52.6 0.0 36.5 89.2 0.0 25.6 48.7 0.01/7/2010 30.0 56.4 0.01/8/2010 25.0 53.8 0.0 26.4 45.3 0.0 14.7 24.2 0.01/9/2010 20.9 45.6 0.01/10/2010 27.2 60.5 0.01/11/2010 18.4 40.9 0.0 27.6 56.8 0.0 18.4 29.9 0.01/12/2010 26.7 58.1 0.0 17.8 30.3 0.01/13/2010 23.1 53.2 0.0 25.3 53.2 0.0 17.9 30.5 0.01/14/2010 25.0 51.2 0.01/15/2010 16.8 38.8 0.0 26.3 61.3 0.0 14.2 27.0 0.01/16/2010 21.7 49.2 0.01/17/2010 25.2 59.5 0.01/18/2010 16.6 36.3 0.0 19.9 45.3 0.0 14.4 24.2 0.01/19/2010 19.1 42.7 0.01/20/2010 17.9 33.5 0.0 18.8 44.0 0.0 15.2 22.7 0.01/21/2010 17.2 42.0 0.01/22/2010 21.1 36.9 0.0 19.6 45.6 0.0 17.6 25.7 0.01/23/2010 23.1 51.9 0.01/24/2010 18.4 43.7 0.01/25/2010 15.4 28.6 0.0 9.9 19.1 0.01/27/2010 16.9 40.1 0.0 12.7 30.5 0.02/3/2010 23.5 36.9 0.0 17.8 29.9 0.02/9/2010 12.6 23.9 0.02/20/2010 14.8 25.6 0.02/26/2010 15.1 28.3 0.03/5/2010 20.0 31.6 0.03/6/2010 17.7 36.9 0.0 19.2 35.5 0.0 18.5 52.7 0.0 3.24 0.0 0.0 0.0 0.03/9/2010 19.0 30.6 0.03/17/2010 53.9 44.6 9.3 30.2 44.7 0.0 27.8 78.4 0.0 5.32 0.0 0.0 0.0 0.0 0.03/18/2010 32.9 48.7 0.03/22/2010 31.3 52.1 0.03/26/2010 35.3 42.6 0.03/30/2010 34.7 44.3 0.04/1/2010 56.0 55.8 0.24/2/2010 23.3 52.0 0.0 41.5 51.4 0.0 45.1 99.7 0.0 6.97 0.0 0.0 0.0 0.0 0.24/5/2010 40.9 43.6 0.04/7/2010 36.1 43.0 0.04/9/2010 66.6 56.5 60.5 0.04/14/2010 200.3 118.8 81.54/15/2010 25.4 35.6 0.0 125.0 143.9 0.0 186.6 168.3 18.4 204.3 259.0 0.0 205.4 151.3 54.0 48.75 28.5 51.7 0.0 0.0 35.74/16/2010 194.8 162.4 32.54/21/2010 323.1 331.6 0.04/27/2010 137.7 145.7 0.05/4/2010 164.9 187.7 0.05/11/2010 174.7 242.6 0.05/18/2010 251.8 328.4 0.05/25/2010 239.5 498.9 0.06/1/2010 174.5 716.5 0.07/19/2010 36.0 140.0 0.0 28.4 55.8 0.0 32.7 118.8 0.0 0.07/22/2010 45.4 162.9 0.08/13/2010 31.8 106.7 0.0 28.8 70.9 0.0 31.2 90.0 0.0 0.08/19/2010 27.6 87.4 0.09/10/2010 74.2 21.5 45.5 0.0 25.7 68.3 0.09/24/2010 2.0 22.4 0.0 16.1 72.9 0.0 22.8 74.9 0.0 26.1 53.5 0.0 26.0 57.8 0.0 0.56 7.8 4.3 3.5 0.0 0.010/13/2010 72.5 46.1 24.9 60.4 0.010/28/2010 21.2 45.3 0.011/9/2010 23.4 49.4 0.011/22/2010 52.5 22.4 34.3 0.0 23.9 42.6 0.012/14/2010 24.0 52.6 0.01/11/2011 20.6 48.3 0.01/17/2011 24.2 50.9 0.0 22.5 82.1 0.0 28.9 137.6 0.0 0.02/16/2011 27.9 51.0 0.0 23.0 79.8 0.0 26.3 94.8 0.0 0.02/22/2011 32.9 54.8 0.03/1/2011 34.6 58.6 0.03/7/2011 28.9 54.7 0.0 35.6 55.3 0.0 44.1 95.1 0.0 47.4 106.6 0.0 8.23 2.5 3.6 0.0 0.0 0.03/8/2011 34.9 54.1 0.03/15/2011 50.7 56.9 0.03/21/2011 20.0 20.9 0.0 111.3 70.3 41.1 119.1 75.0 44.2 137.4 141.1 0.0 8.62 5.1 7.6 0.0 0.0 13.93/22/2011 133.0 74.9 58.13/28/2011 93.2 65.0 28.2 85.6 101.4 0.0 93.0 125.8 0.0 0.0 6.43/29/2011 99.6 65.0 34.64/4/2011 33.1 27.1 6.0 124.4 93.6 30.8 240.2 112.8 127.4 329.1 189.0 140.1 11.90 10.7 19.6 0.0 12.7 0.04/5/2011 196.9 110.1 86.84/12/2011 279.7 138.4 141.34/18/2011 53.8 47.0 6.8 175.6 152.1 23.5 233.9 166.9 67.0 307.0 327.4 0.0 20.69 9.1 18.1 0.0 0.0 127.0

SWData_WQS_REV.xlsxZnYearRedctn 2 of 3

Page 173: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Appendix C-1Yearly Average Zinc Load Calculations by Station and Zinc Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

Reduction Beyond 5a

4/19/2011 386.0 192.0 194.04/22/2011 361.5 220.3 141.2 305.6 279.8 25.7 424.3 375.9 48.5 0.0 4.24/26/2011 328.5 183.2 145.35/3/2011 208.0 140.7 67.35/4/2011 37.8 41.5 0.0 148.5 135.1 13.4 174.7 144.6 30.1 180.5 128.0 52.5 5.58 5.0 5.9 0.0 22.4 37.25/10/2011 472.9 496.5 0.05/31/2011 190.1 829.6 0.0 194.9 420.2 0.0 244.9 722.1 0.0 0.06/14/2011 216.0 1064.2 0.06/15/2011 112.1 1065.1 0.0 109.6 607.0 0.0 110.1 864.9 0.0 0.07/12/2011 230.0 684.7 0.07/20/2011 52.9 486.3 0.0 51.1 265.1 0.0 53.4 331.4 0.0 0.08/17/2011 30.7 138.3 0.0 31.0 96.9 0.0 38.0 131.9 0.0 0.09/21/2011 27.0 84.8 0.0 22.4 67.0 0.0 34.5 72.9 0.0 0.010/11/2011 1.2 25.3 0.0 16.9 78.3 0.0 27.3 79.4 0.0 40.7 77.6 0.0 5.11 7.3 5.9 1.4 0.010/19/2011 26.9 88.0 0.0 24.4 69.9 0.0 31.5 76.5 0.0 0.011/17/2011 33.0 59.5 0.0 29.0 42.3 0.0 27.7 68.1 0.0 0.012/14/2011 20.9 52.1 0.0 20.4 40.0 0.0 25.2 47.4 0.0 0.01/18/2012 20.2 45.8 0.0 17.2 79.5 0.0 22.4 99.3 0.0 0.02/15/2012 16.8 41.6 0.0 15.1 61.9 0.0 16.9 63.8 0.0 0.03/12/2012 3.1 13.8 0.0 33.1 47.4 0.0 42.7 48.1 0.0 1.95 4.8 4.9 0.03/19/2012 47.6 57.9 0.0 42.3 59.7 0.0 47.9 88.0 0.0 0.03/26/2012 10.1 31.3 0.0 61.2 101.6 0.0 72.5 119.2 0.0 88.4 235.5 0.0 9.40 3.3 10.7 0.0 0.04/3/2012 111.5 152.6 0.04/10/2012 19.9 40.8 0.0 31.4 130.8 0.0 49.9 134.9 0.0 70.9 271.6 0.0 6.71 5.2 17.5 0.0 0.04/11/2012 64.8 233.6 0.0 53.6 228.5 0.0 94.2 379.5 0.0 0.04/17/2012 65.1 126.4 0.05/16/2012 32.2 356.7 0.0 30.8 147.9 0.0 41.7 249.4 0.0 0.06/27/2012 20.2 59.0 0.0 20.6 56.5 0.0 19.2 63.1 0.0 0.07/24/2012 19.0 54.8 0.0 9.5 43.7 0.0 24.7 50.0 0.0 0.08/15/2012 14.9 57.5 0.0 13.3 53.4 0.0 12.5 51.6 0.0 0.09/13/2012 13.4 44.4 0.0 12.2 45.5 0.0 14.1 52.7 0.0 0.010/11/2012 24.3 45.0 0.0 22.4 34.2 0.0 19.0 34.2 0.0 0.010/18/2012 1.3 13.1 0.0 7.6 40.5 0.0 14.4 44.6 0.0 11.5 29.4 0.0 11.1 39.8 0.0 1.32 3.4 4.8 0.0 0.0 0.011/15/2012 18.7 45.7 0.0 15.6 37.6 0.0 17.2 44.3 0.0 0.012/14/2012 18.9 39.8 0.0 16.2 43.1 0.0 19.3 53.0 0.0 0.0

All Sampling Events Equal WeightAverage 24.6 49.3 27.6 72.2 181.9 118.3 71.0 139.3 51.9 111.8 220.7 59.3 98.6 149.7 82.2 77.4 125.6 56.1 115.2 160.5 68.8 91.7 148.3 112.6 105.3 126.5 99.8 5.66 5.7 16.4 1.6 17.6 35.4Maximum 365.4 302.0 120.0 661.5 919.2 481.8 653.8 916.8 468.4 343.6 930.1 195.7 653.4 1065.1 454.7 388.8 607.0 120.9 692.3 547.8 418.8 740.6 864.9 399.8 646.5 1064.2 450.3 48.75 28.5 187.0 3.5 22.4 137.9Max Measured Spring Load

125.2 94.0 69.3 661.5 304.9 481.8 653.8 317.5 468.4 343.6 430.4 195.7 653.4 438.8 454.7 388.8 417.3 120.9 692.3 547.8 418.8 740.6 618.3 399.8 646.5 344.0 450.3 48.75 28.5 51.7 0.0 12.7 137.9

SPRING2005 18.9 18.5 3.8 66.3 54.8 26.2 65.6 48.1 17.4 92.3 63.9 28.3 56.6 54.2 21.1 68.8 68.5 26.4 69.8 96.3 55.4 90.7 45.3 47.1 29.9 10.80 4.2 5.9 None None2006 34.0 57.4 168.1 184.1 43.4 163.5 192.8 35.0 231.0 183.1 72.6 253.7 182.7 96.4 223.0 181.1 64.7 221.6 249.5 28.3 307.7 295.1 62.3 265.6 159.0 106.6 7.28 7.0 17.5 None 86.12007 21.3 35.5 79.7 108.0 71.9 116.5 88.9 124.2 91.0 110.8 8.4 119.4 174.5 109.4 196.1 94.9 110.5 8.4 3.76 4.9 13.2 None None2008 64.2 35.2 69.3 359.8 112.1 247.8 350.3 117.3 468.4 208.0 94.9 235.0 366.4 172.8 418.8 238.9 165.1 187.1 216.4 101.8 179.0 2.90 5.9 10.9 None 5.62009 22.5 23.0 5.7 90.0 75.9 14.1 102.1 83.9 18.2 125.5 163.1 104.2 103.7 24.7 3.22 4.9 12.0 None 11.42010 25.4 35.6 55.0 69.3 9.3 69.4 73.3 18.4 73.9 122.4 94.9 90.8 42.0 16.07 28.5 51.7 None 17.92011 35.6 31.7 6.4 110.1 92.7 31.8 180.6 115.9 81.6 195.6 190.6 25.7 44.1 95.1 223.0 211.0 94.3 171.5 103.7 110.0 12.36 6.8 12.2 12.7 37.92012 11.0 28.6 41.9 93.2 64.9 124.7 47.9 144.1 75.3 243.7 6.02 4.4 11.0 None NoneAverage 29.1 33.2 21.3 168.5 114.8 105.8 118.5 100.7 96.0 137.4 123.7 50.5 128.3 105.0 68.4 133.8 146.1 38.9 164.3 157.6 223.5 151.2 185.9 114.6 141.8 102.4 71.5 7.80 8.4 16.8 0.0 12.7 31.8Min 11.0 18.5 3.8 66.3 54.8 26.2 41.9 48.1 9.3 88.9 63.9 28.3 56.6 54.2 8.4 47.9 68.5 25.7 44.1 95.1 28.3 55.4 90.7 62.3 45.3 47.1 8.4 2.90 4.2 5.9 0.0 12.7 5.6Max 64.2 57.4 69.3 359.8 184.1 247.8 350.3 192.8 468.4 231.0 183.1 72.6 253.7 182.7 235.0 223.0 190.6 64.7 366.4 249.5 418.8 307.7 295.1 187.1 265.6 159.0 179.0 16.07 28.5 51.7 0.0 12.7 86.12008 Average w/o 4/22/08

3.2 14.6 58.2 44.4 46.8 49.2 144.4 80.0 161.8 40.6 72.1 167.2 140.0 116.3 177.3 93.2 140.2 2.42 5.6 9.3 0.0 None 1.9

Ave Yearly w/o 4/22/08 21.5 30.6 5.3 93.1 97.8 34.8 80.6 92.2 21.5 137.4 123.7 50.5 120.3 103.2 58.0 133.8 146.1 38.9 99.1 137.5 28.3 142.2 182.8 90.9 136.3 101.1 66.0 7.74 8.3 16.6 0.0 12.7 31.0

FALL2005 2.1 20.6 23.5 59.0 25.1 62.8 25.8 60.2 26.1 62.5 23.2 30.6 25.0 48.0 28.6 49.8 24.9 53.0 3.76 1.9 6.9 None None2006 1.6 24.3 29.9 74.6 25.8 76.8 31.6 81.0 37.1 62.3 37.7 77.4 35.7 80.6 2.73 3.9 8.4 None None2007 1.9 25.6 16.3 74.8 21.0 80.9 19.9 74.2 22.7 55.9 22.1 63.3 18.5 69.0 2.95 2.6 9.5 None None2008 1.4 19.9 8.4 58.3 11.3 62.1 17.0 71.2 18.5 64.1 16.7 34.0 18.4 44.5 18.4 53.5 17.0 52.6 0.74 4.6 4.6 0.7 None None2009 1.9 23.5 17.3 71.6 25.9 71.6 26.6 24.7 1.9 30.3 42.8 21.1 47.4 1.11 2.2 2.7 None None2010 2.0 22.4 16.1 72.9 22.8 68.5 22.0 42.0 25.1 56.2 23.6 51.3 0.56 7.8 4.3 3.5 None None2011 1.2 25.3 16.9 78.3 27.0 72.8 24.0 54.8 31.9 68.5 5.11 7.3 5.9 1.4 None None2012 1.3 13.1 7.6 40.5 17.9 43.9 16.6 40.1 16.2 42.7 11.1 39.8 1.32 3.4 4.8 None NoneAverage 1.7 21.8 0.0 19.5 66.7 0.0 17.6 68.2 0.0 21.4 65.7 0.0 23.7 67.3 0.0 20.5 40.3 0.0 26.0 47.1 1.9 26.3 56.8 0.0 21.7 56.2 0.0 2.29 4.2 5.9 1.9 0.0 0.0Min 1.2 13.1 0.0 8.4 58.3 0.0 7.6 40.5 0.0 17.0 60.2 0.0 17.9 43.9 0.0 16.6 30.6 0.0 18.4 24.7 1.9 16.2 42.7 0.0 11.1 39.8 0.0 0.56 1.9 2.7 0.7 0.0 0.0Max 2.1 25.6 0.0 29.9 74.8 0.0 25.8 80.9 0.0 25.8 71.2 0.0 31.6 81.0 0.0 24.0 54.8 0.0 37.1 62.3 1.9 37.7 77.4 0.0 35.7 80.6 0.0 5.11 7.8 9.5 3.5 0.0 0.0Notes:Measured Load = calculated using the measured concentration, or if not detected half the detection limit, on the day identified and the calculated or measured flow for the identified date.WQS Load = Load calculated using the measured hardness from a sample collected on the identified day and the measured or calculated flow rate for the station on the identified date, WQS equations are determined by station and date.Reduce = Load above the WQS load = Measured Load minus WQS LoadSpring = March and AprilFall = September through DecemberAverages do not include zero values; thus average reduction is based solely on events where the reduction is requiredAverage Calculations for a station (e.g., E-22) in other Appendices' tables may be skewed as concentrations from one sample date have been "surrogated" to represent the concentration for the day that most other stations were measured. These surrogate loads have been removed from this table/Appendix for averaging purposes

Numbers in italics were calculated using load reductions for different days

SWData_WQS_REV.xlsxZnYearRedctn 3 of 3

Page 174: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

APPENDIX C-2

YEARLY AVERAGE CADMIUM LOAD CALCULATIONS AND

CADMIUM LOAD REDUCTION CALCULATIONS

Page 175: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Appendix C-2Yearly Average Cadmium Load Calculations by Station and Cadmium Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

1/14/2005 0.007 0.050 0.000 0.020 0.173 0.000 0.022 0.196 0.000 0.034 0.205 0.000 0.031 0.195 0.000 0.033 0.204 0.000 0.028 0.274 0.000 0.028 0.297 0.000 0.042 0.264 0.000 0.005 0.004 0.041 0.000 0.000 0.0003/3/2005 0.063 0.204 0.000 0.041 0.345 0.000 0.039 0.351 0.000 0.001 0.018 0.000 0.000 0.0003/10/2005 0.066 0.238 0.000 0.067 0.354 0.000 0.058 0.388 0.000 0.001 0.019 0.000 0.000 0.0003/17/2005 0.036 0.049 0.000 0.101 0.173 0.000 0.098 0.190 0.000 0.133 0.219 0.000 0.086 0.226 0.000 0.069 0.226 0.000 0.065 0.338 0.000 0.064 0.369 0.000 0.053 0.381 0.000 0.015 0.001 0.018 0.000 0.000 0.0003/24/2005 0.063 0.215 0.000 0.064 0.326 0.000 0.055 0.361 0.000 0.001 0.019 0.000 0.000 0.0003/31/2005 0.110 0.228 0.000 0.097 0.374 0.000 0.076 0.399 0.000 0.002 0.025 0.000 0.000 0.0004/3/2005 0.083 0.395 0.000 0.111 0.452 0.0004/4/2005 0.234 0.327 0.000 0.177 0.370 0.0004/5/2005 0.110 0.085 0.025 0.178 0.317 0.0004/12/2005 0.078 0.060 0.018 0.192 0.223 0.000 0.214 0.237 0.000 0.297 0.284 0.013 0.238 0.287 0.000 0.192 0.279 0.000 0.174 0.457 0.000 0.218 0.520 0.000 0.183 0.478 0.000 0.030 0.003 0.063 0.000 0.000 0.0005/23/2005 0.923 0.900 0.023 0.979 3.249 0.000 1.042 3.223 0.000 1.057 3.329 0.000 1.029 3.239 0.000 0.834 3.103 0.000 0.807 3.870 0.000 0.358 4.701 0.000 0.860 5.943 0.000 0.024 0.092 0.560 0.000 0.000 0.0006/28/2005 0.811 0.797 0.797 0.906 0.6837/29/2005 0.234 0.227 0.227 0.258 0.1848/25/2005 0.128 0.122 0.122 0.138 0.0599/12/2005 0.008 0.067 0.000 0.033 0.239 0.000 0.051 0.257 0.000 0.047 0.257 0.000 0.048 0.251 0.000 0.041 0.249 0.000 0.038 0.372 0.000 0.012 0.329 0.000 0.042 0.361 0.000 0.016 0.004 0.050 0.000 0.000 0.0009/22/2005 0.114 0.108 0.108 0.122 0.05710/18/2005 0.012 0.076 0.000 0.059 0.271 0.000 0.068 0.294 0.000 0.072 0.271 0.000 0.051 0.294 0.000 0.054 0.296 0.000 0.066 0.449 0.000 0.085 0.556 0.000 0.056 0.574 0.000 0.003 0.008 0.085 0.000 0.000 0.00010/25/2005 0.166 0.159 0.159 0.181 0.0891/31/2006 0.009 0.051 0.000 0.025 0.189 0.000 0.060 0.219 0.000 0.050 0.197 0.000 0.036 0.297 0.000 0.046 0.337 0.000 0.046 0.361 0.000 0.012 0.002 0.025 0.000 0.000 0.0003/9/2006 0.896 0.445 0.451 0.701 0.479 0.222 0.701 0.427 0.274 0.687 0.628 0.059 0.789 0.873 0.000 0.839 0.879 0.000 0.004 0.070 0.000 0.000 0.0003/15/2006 0.299 0.305 0.294 0.408 0.0273/16/2006 0.390 0.301 0.088 0.326 0.525 0.000 0.326 0.557 0.000 0.004 0.063 0.000 0.000 0.0003/22/2006 0.360 0.276 0.084 0.340 0.280 0.060 0.320 0.277 0.042 0.339 0.417 0.000 0.018 0.028 0.0003/23/2006 0.039 0.072 0.000 0.356 0.271 0.085 0.373 0.294 0.079 0.295 0.297 0.000 0.286 0.430 0.000 0.300 0.522 0.000 0.248 0.568 0.000 0.019 0.004 0.063 0.000 0.000 0.0003/29/2006 0.296 0.315 0.302 0.436 0.0413/30/2006 0.431 0.315 0.116 0.401 0.540 0.000 0.327 0.602 0.000 0.004 0.074 0.000 0.000 0.0004/5/2006 0.992 0.671 0.321 0.913 0.655 0.258 0.865 0.672 0.193 0.873 0.889 0.000 0.043 0.081 0.0004/6/2006 1.098 0.839 0.259 1.198 1.350 0.000 0.979 1.581 0.000 0.015 0.118 0.000 0.000 0.0004/12/2006 1.045 0.961 1.011 1.323 0.1064/13/2006 2.225 1.504 0.721 1.869 2.370 0.000 1.439 2.959 0.000 0.013 0.153 0.000 0.000 0.0004/19/2006 0.661 1.480 0.000 1.555 1.516 0.039 1.426 1.500 0.000 0.737 1.923 0.000 0.111 0.107 0.0044/20/2006 0.270 0.333 0.000 0.842 1.333 0.000 1.002 1.394 0.000 1.160 1.415 0.000 0.800 1.834 0.000 1.479 2.666 0.000 1.735 2.453 0.000 0.013 0.010 0.100 0.000 0.000 0.0004/26/2006 1.902 1.932 1.848 2.385 0.1265/22/2006 0.170 0.909 0.000 0.340 3.248 0.000 0.266 3.300 0.000 0.281 3.457 0.000 0.614 4.113 0.000 0.331 5.485 0.000 0.331 5.849 0.000 0.012 0.086 0.557 0.000 0.000 0.0005/23/2006 2.284 3.466 0.000 2.252 3.608 0.000 2.252 3.417 0.000 2.564 4.181 0.000 0.999 1.740 0.0009/27/2006 0.015 0.092 0.000 0.049 0.358 0.000 0.052 0.368 0.000 0.035 0.388 0.000 0.092 0.554 0.000 0.064 0.686 0.000 0.082 0.714 0.000 0.002 0.012 0.089 0.000 0.000 0.00010/23/2006 0.029 0.083 0.000 0.087 0.310 0.000 0.124 0.327 0.000 0.081 0.340 0.000 0.088 0.544 0.000 0.139 0.697 0.000 0.087 0.718 0.000 0.007 0.017 0.076 0.000 0.000 0.0001/29/2007 0.007 0.061 0.000 0.023 0.209 0.000 0.026 0.237 0.000 0.042 0.230 0.000 0.027 0.388 0.000 0.027 0.449 0.000 0.022 0.463 0.000 0.012 0.001 0.019 0.000 0.000 0.0003/2/2007 0.019 0.141 0.000 0.018 0.230 0.000 0.015 0.253 0.000 0.001 0.016 0.000 0.000 0.0003/13/2007 0.104 0.238 0.000 0.121 0.410 0.000 0.094 0.439 0.000 0.003 0.053 0.000 0.000 0.0003/14/2007 0.099 0.267 0.000 0.100 0.286 0.000 0.0053/20/2007 0.064 0.101 0.000 0.199 0.376 0.000 0.208 0.418 0.000 0.223 0.426 0.000 0.222 0.617 0.000 0.237 0.715 0.000 0.173 0.801 0.000 0.006 0.004 0.062 0.000 0.000 0.0003/21/2007 0.199 0.362 0.000 0.202 0.394 0.000 0.0073/27/2007 0.276 0.464 0.000 0.331 0.800 0.000 0.249 0.937 0.000 0.005 0.059 0.000 0.000 0.0003/28/2007 0.234 0.469 0.000 0.237 0.489 0.000 0.0124/3/2007 0.195 0.454 0.000 0.227 0.772 0.000 0.208 0.842 0.000 0.005 0.064 0.000 0.000 0.0004/4/2007 0.207 0.442 0.000 0.210 0.470 0.000 0.0104/10/2007 0.324 0.631 0.000 0.398 1.137 0.000 0.344 1.287 0.000 0.006 0.076 0.000 0.000 0.0004/11/2007 0.263 0.536 0.000 0.267 0.605 0.000 0.0014/17/2007 0.081 0.152 0.000 0.249 0.581 0.000 0.266 0.615 0.000 0.318 0.644 0.000 0.321 0.880 0.000 0.385 1.160 0.000 0.318 1.334 0.000 0.009 0.006 0.074 0.000 0.000 0.0004/18/2007 0.013 0.728 0.000 0.013 0.747 0.000 0.0104/24/2007 0.332 0.913 0.000 0.342 1.614 0.000 0.332 1.830 0.000 0.010 0.097 0.000 0.000 0.0004/26/2007 0.371 0.822 0.000 0.376 0.853 0.000 0.0139/25/2007 0.013 0.091 0.000 0.019 0.337 0.000 0.039 0.375 0.000 0.014 0.335 0.000 0.017 0.508 0.000 0.023 0.590 0.000 0.023 0.623 0.000 0.006 0.008 0.114 0.000 0.000 0.00010/16/2007 0.012 0.088 0.000 0.013 0.315 0.000 0.014 0.335 0.000 0.013 0.316 0.000 0.016 0.464 0.000 0.021 0.532 0.000 0.021 0.588 0.000 0.005 0.005 0.067 0.000 0.000 0.0001/28/2008 0.006 0.157 0.000 0.014 0.189 0.000 0.006 0.178 0.000 0.007 0.223 0.000 0.008 0.234 0.000 0.008 0.266 0.000 0.001 0.001 0.022 0.000 0.000 0.0003/4/2008 2.930 0.181 2.749 0.055 0.295 0.000 0.049 0.332 0.000 0.006 0.026 0.000 0.000 0.0003/11/2008 0.066 0.178 0.000 0.044 0.275 0.000 0.042 0.305 0.000 0.003 0.025 0.000 0.000 0.0003/18/2008 0.055 0.175 0.000 0.054 0.300 0.000 0.036 0.317 0.000 0.004 0.025 0.000 0.000 0.0003/25/2008 0.023 0.051 0.000 0.129 0.190 0.000 0.120 0.213 0.000 0.096 0.213 0.000 0.073 0.300 0.000 0.087 0.335 0.000 0.065 0.373 0.000 0.004 0.002 0.028 0.000 0.000 0.0004/2/2008 0.217 0.444 0.0004/8/2008 0.410 0.244 0.166 0.443 0.445 0.000 0.306 0.479 0.000 0.002 0.036 0.000 0.000 0.0004/9/2008 0.430 0.458 0.0004/15/2008 1.007 0.479 0.528 1.121 0.833 0.288 0.686 0.983 0.000 0.003 0.068 0.000 0.000 0.0004/16/2008 1.093 1.018 0.0754/22/2008 0.376 0.197 0.179 2.772 0.784 1.988 2.698 0.814 1.884 2.457 0.860 1.597 2.514 1.163 1.351 2.700 1.475 1.225 2.274 1.697 0.577 0.007 0.008 0.101 0.000 0.000 0.0004/23/2008 2.093 2.144 0.0004/29/2008 1.332 0.964 0.368 1.821 1.718 0.103 1.391 1.972 0.000 0.009 0.098 0.000 0.000 0.0005/1/2008 1.352 3.231 0.0005/28/2008 1.745 0.956 0.789 0.407 3.623 0.000 0.513 3.805 0.000 0.680 3.807 0.000 0.710 3.804 0.000 0.788 3.804 0.000 0.881 6.356 0.000 0.038 0.718 0.545 0.173 0.0006/24/2008 2.022 1.093 0.929 0.344 4.143 0.000 0.297 4.164 0.000 0.301 4.224 0.000 0.365 4.164 0.000 0.356 4.164 0.000 0.401 6.186 0.000 0.023 0.918 0.595 0.323 0.0007/29/2008 0.638 0.286 0.352 0.077 1.099 0.000 0.078 1.078 0.000 0.110 1.072 0.000 0.092 1.094 0.000 0.085 1.073 0.000 0.117 1.745 0.000 0.011 0.348 0.252 0.097 0.0008/26/2008 0.189 0.120 0.069 0.043 0.443 0.000 0.057 0.465 0.000 0.003 0.086 0.089 0.0008/27/2008 0.056 0.436 0.000 0.058 0.440 0.000 0.051 0.440 0.000 0.068 0.750 0.000 0.0009/17/2008 0.103 0.080 0.023 0.029 0.295 0.000 0.036 0.308 0.000 0.002 0.038 0.046 0.0009/18/2008 0.042 0.335 0.000 0.040 0.330 0.000 0.040 0.321 0.000 0.039 0.574 0.000 0.0009/29/2008 0.009 0.062 0.000 0.024 0.227 0.000 0.010 0.244 0.000 0.032 0.251 0.000 0.011 0.373 0.000 0.014 0.412 0.000 0.014 0.435 0.000 0.001 0.004 0.048 0.000 0.000 0.00010/20/2008 0.027 0.062 0.000 0.025 0.223 0.000 0.027 0.248 0.000 0.021 0.250 0.000 0.028 0.379 0.000 0.041 0.400 0.000 0.024 0.413 0.000 0.000 0.003 0.045 0.000 0.000 0.00010/21/2008 0.086 0.071 0.015 0.022 0.255 0.000 0.028 0.277 0.000 0.002 0.003 0.039 0.00010/22/2008 0.035 0.278 0.000 0.031 0.272 0.000 0.029 0.272 0.000 0.034 0.451 0.000 0.00010/29/2008 0.030 0.551 0.00011/11/2008 0.014 0.448 0.00012/9/2008 0.021 0.394 0.0001/8/2009 0.089 0.271 0.000 0.083 0.268 0.0001/14/2009 0.022 0.405 0.0002/11/2009 0.037 0.371 0.0002/19/2009 0.027 0.045 0.000 0.033 0.180 0.000 0.031 0.197 0.000 0.039 0.305 0.000 0.001 0.0003/3/2009 0.102 0.371 0.0003/10/2009 0.074 0.426 0.0003/11/2009 0.080 0.050 0.030 0.111 0.183 0.000 0.104 0.197 0.000 0.098 0.416 0.000 0.004 0.011 0.035 0.000 0.0003/17/2009 0.064 0.399 0.0003/20/2009 0.076 0.066 0.010 0.216 0.280 0.000 0.204 0.297 0.000 0.0053/24/2009 0.251 0.704 0.0003/25/2009 0.056 0.075 0.000 0.262 0.310 0.000 0.207 0.322 0.000 0.291 0.594 0.000 0.007 0.020 0.053 0.000 0.0004/7/2009 0.153 0.558 0.000

Reduction Beyond 5a

SWData_WQS_REV.xlsxCdYearRedctn 1 of 3

Page 176: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Appendix C-2Yearly Average Cadmium Load Calculations by Station and Cadmium Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

Reduction Beyond 5a

4/8/2009 0.064 0.082 0.000 0.174 0.355 0.000 0.279 0.418 0.000 0.195 0.732 0.000 0.006 0.019 0.065 0.000 0.0004/14/2009 0.354 0.975 0.0004/20/2009 0.270 0.132 0.139 0.535 0.541 0.000 0.678 0.581 0.097 0.967 1.015 0.000 0.009 0.030 0.073 0.000 0.0004/21/2009 0.345 1.512 0.0004/28/2009 0.819 2.293 0.0005/12/2009 0.235 4.717 0.0006/9/2009 0.260 5.683 0.0007/14/2009 0.071 1.294 0.0008/11/2009 0.025 0.691 0.0009/16/2009 0.035 0.598 0.0009/23/2009 0.056 0.082 0.000 0.066 0.314 0.000 0.063 0.313 0.000 0.095 0.492 0.000 0.002 0.011 0.026 0.000 0.00010/13/2009 0.013 0.398 0.00011/10/2009 0.042 0.343 0.00012/8/2009 0.042 0.406 0.00012/30/2009 0.076 0.368 0.00012/31/2009 0.056 0.214 0.000 0.053 0.247 0.000 0.031 0.275 0.0001/2/2010 0.058 0.325 0.0001/3/2010 0.044 0.228 0.0001/4/2010 0.032 0.162 0.000 0.029 0.196 0.000 0.026 0.226 0.0001/5/2010 0.031 0.226 0.0001/6/2010 0.042 0.222 0.000 0.048 0.366 0.000 0.037 0.402 0.0001/7/2010 0.032 0.238 0.0001/8/2010 0.035 0.222 0.000 0.032 0.191 0.000 0.012 0.205 0.0001/9/2010 0.024 0.192 0.0001/10/2010 0.030 0.254 0.0001/11/2010 0.024 0.175 0.000 0.037 0.239 0.000 0.015 0.254 0.0001/12/2010 0.033 0.242 0.000 0.028 0.255 0.0001/13/2010 0.051 0.222 0.000 0.029 0.224 0.000 0.028 0.257 0.0001/14/2010 0.025 0.216 0.0001/15/2010 0.022 0.165 0.000 0.041 0.252 0.000 0.026 0.228 0.0001/16/2010 0.021 0.207 0.0001/17/2010 0.017 0.251 0.0001/18/2010 0.021 0.154 0.000 0.018 0.191 0.000 0.024 0.205 0.0001/19/2010 0.016 0.179 0.0001/20/2010 0.029 0.143 0.000 0.015 0.184 0.000 0.022 0.193 0.0001/21/2010 0.021 0.177 0.0001/22/2010 0.005 0.157 0.000 0.023 0.192 0.000 0.024 0.217 0.0001/23/2010 0.021 0.217 0.0001/24/2010 0.019 0.183 0.0001/25/2010 0.004 0.122 0.000 0.004 0.160 0.0001/27/2010 0.023 0.170 0.000 0.007 0.257 0.0002/3/2010 0.031 0.157 0.000 0.024 0.248 0.0002/9/2010 0.018 0.197 0.0002/20/2010 0.030 0.212 0.0002/26/2010 0.011 0.234 0.0003/5/2010 0.036 0.260 0.0003/6/2010 0.044 0.157 0.000 0.032 0.151 0.000 0.022 0.216 0.000 0.006 0.000 0.000 0.000 0.0003/9/2010 0.006 0.253 0.0003/17/2010 0.146 0.191 0.000 0.046 0.190 0.000 0.025 0.320 0.000 0.010 0.000 0.000 0.000 0.0003/18/2010 0.035 0.399 0.0003/22/2010 0.035 0.423 0.0003/26/2010 0.050 0.353 0.0003/30/2010 0.053 0.367 0.0004/1/2010 0.075 0.469 0.0004/2/2010 0.055 0.226 0.000 0.084 0.222 0.000 0.069 0.414 0.000 0.017 0.000 0.000 0.000 0.0004/5/2010 0.074 0.364 0.0004/7/2010 0.055 0.360 0.0004/9/2010 0.282 0.078 0.506 0.0004/14/2010 0.410 1.051 0.0004/15/2010 0.071 0.132 0.000 0.276 0.648 0.000 0.432 0.744 0.000 0.579 1.154 0.000 0.546 1.345 0.000 0.116 0.079 0.247 0.000 0.000 0.0004/16/2010 0.443 1.483 0.0004/21/2010 0.718 2.948 0.0004/27/2010 0.375 1.322 0.0005/4/2010 0.478 1.644 0.0005/11/2010 0.094 2.175 0.0005/18/2010 0.127 2.944 0.0005/25/2010 0.193 4.471 0.0006/1/2010 7.270 6.626 0.6447/19/2010 0.025 0.613 0.000 0.025 0.510 0.000 0.041 1.051 0.000 0.0007/22/2010 0.101 1.422 0.0008/13/2010 0.021 0.472 0.000 0.021 0.617 0.000 0.034 0.805 0.000 0.0008/19/2010 0.026 0.760 0.0009/10/2010 0.044 0.319 0.000 0.046 0.388 0.000 0.017 0.582 0.000 0.0009/24/2010 0.010 0.077 0.000 0.037 0.314 0.000 0.042 0.320 0.000 0.127 0.466 0.000 0.032 0.499 0.000 0.001 0.027 0.041 0.000 0.000 0.00010/13/2010 0.036 0.309 0.000 0.038 0.389 0.000 0.015 0.515 0.000 0.00010/28/2010 0.050 0.390 0.00011/9/2010 0.027 0.425 0.00011/22/2010 0.050 0.226 0.000 0.039 0.291 0.000 0.012 0.366 0.000 0.00012/14/2010 0.025 0.445 0.0001/11/2011 0.044 0.407 0.0001/17/2011 0.221 0.337 0.5532/16/2011 0.008 0.219 0.000 0.008 0.325 0.000 0.011 0.392 0.000 0.0002/22/2011 0.041 0.451 0.0003/1/2011 0.044 0.483 0.0003/7/2011 0.076 0.237 0.000 0.078 0.238 0.000 0.115 0.389 0.000 0.075 0.441 0.000 0.022 0.003 0.017 0.000 0.000 0.0003/8/2011 0.024 0.454 0.0003/15/2011 0.100 0.477 0.0003/21/2011 0.082 0.073 0.009 0.337 0.306 0.032 0.302 0.322 0.000 0.316 0.589 0.000 0.019 0.010 0.035 0.000 0.0003/22/2011 0.297 0.638 0.0003/28/2011 0.231 0.282 0.000 0.298 0.417 0.000 0.205 0.527 0.000 0.000 0.0003/29/2011 0.234 0.555 0.0004/4/2011 0.104 0.097 0.007 0.354 0.413 0.000 0.677 0.486 0.191 0.838 0.808 0.030 0.026 0.005 0.089 0.000 0.000 0.0004/5/2011 0.478 0.934 0.0004/12/2011 0.783 1.196 0.0004/18/2011 0.125 0.168 0.000 0.507 0.679 0.000 0.643 0.736 0.000 0.823 1.414 0.000 0.049 0.021 0.085 0.000 0.000

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Page 177: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Appendix C-2Yearly Average Cadmium Load Calculations by Station and Cadmium Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

Reduction Beyond 5a

4/19/2011 1.061 1.698 0.0004/22/2011 1.090 0.972 0.118 1.176 1.201 0.000 1.186 1.654 0.000 0.0004/26/2011 0.966 1.589 0.0005/3/2011 0.688 1.210 0.0005/4/2011 2.522 0.147 2.375 0.579 0.596 0.000 0.778 0.632 0.145 0.621 1.125 0.000 0.014 0.005 0.057 0.000 0.0005/10/2011 1.467 4.426 0.0005/31/2011 0.197 3.746 0.000 0.197 3.851 0.000 0.338 6.617 0.000 0.0006/14/2011 0.540 9.842 0.0006/15/2011 0.313 4.931 0.000 0.313 5.625 0.000 0.540 8.192 0.000 0.0007/12/2011 3.833 6.571 0.0007/20/2011 0.132 2.231 0.000 0.132 2.447 0.000 0.226 3.172 0.000 0.0008/17/2011 0.029 0.616 0.000 0.029 0.843 0.000 0.048 1.172 0.000 0.0009/21/2011 0.016 0.373 0.000 0.089 0.568 0.000 0.025 0.643 0.000 0.00010/11/2011 0.012 0.088 0.000 0.045 0.343 0.000 0.069 0.346 0.000 0.088 0.667 0.000 0.010 0.016 0.057 0.000 0.00010/19/2011 0.059 0.378 0.000 0.070 0.577 0.000 0.020 0.657 0.000 0.00011/17/2011 0.053 0.255 0.000 0.053 0.353 0.000 0.052 0.560 0.000 0.00012/14/2011 0.060 0.222 0.000 0.056 0.329 0.000 0.067 0.396 0.000 0.0001/18/2012 0.041 0.196 0.000 0.035 0.320 0.000 0.037 0.402 0.000 0.0002/15/2012 0.032 0.177 0.000 0.030 0.252 0.000 0.007 0.265 0.000 0.0003/12/2012 0.006 0.047 0.000 0.071 0.203 0.000 0.082 0.205 0.000 0.003 0.004 0.022 0.0003/19/2012 0.087 0.251 0.000 0.099 0.258 0.000 0.106 0.379 0.000 0.0003/26/2012 0.020 0.113 0.000 0.164 0.457 0.000 0.202 0.526 0.000 0.199 1.013 0.000 0.018 0.004 0.051 0.000 0.0004/3/2012 0.226 0.678 0.0004/10/2012 0.034 0.152 0.000 0.079 0.607 0.000 0.109 0.623 0.000 0.064 1.227 0.000 0.015 0.010 0.087 0.000 0.0004/11/2012 0.041 1.017 0.000 0.186 0.998 0.000 0.067 1.657 0.000 0.0004/17/2012 0.122 0.566 0.0005/16/2012 0.062 1.553 0.000 0.062 1.338 0.000 0.104 2.255 0.000 0.0006/27/2012 0.044 0.280 0.000 0.022 0.506 0.000 0.035 0.590 0.000 0.0007/24/2012 0.245 0.376 0.4438/15/2012 0.013 0.259 0.000 0.058 0.454 0.000 0.020 0.463 0.000 0.0009/13/2012 0.011 0.200 0.000 0.011 0.384 0.000 0.015 0.457 0.000 0.00010/11/2012 0.066 0.191 0.000 0.067 0.281 0.000 0.052 0.289 0.000 0.00010/18/2012 0.007 0.046 0.000 0.022 0.179 0.000 0.027 0.194 0.000 0.030 0.260 0.000 0.035 0.340 0.000 0.002 0.003 0.045 0.000 0.000 0.00011/15/2012 0.051 0.195 0.000 0.036 0.308 0.000 0.049 0.367 0.000 0.00012/14/2012 0.173 0.347 0.430

All Sampling Events Equal WeightAverage 0.233 0.173 0.312 0.264 0.814 1.037 0.232 0.615 0.665 0.372 0.992 0.217 0.321 0.665 0.454 0.223 0.837 0.170 0.372 0.928 0.705 0.230 0.896 0.412 0.351 1.116 0.432 0.012 0.067 0.114 0.149 0.000 0.000Maximum 2.522 1.093 2.375 2.772 4.143 1.988 2.698 4.164 1.884 2.284 4.224 0.451 2.930 4.931 2.749 2.252 5.625 0.274 2.564 4.181 1.351 2.700 8.192 1.225 7.270 9.842 0.644 0.116 0.999 1.740 0.323 0.000 0.000Max Measured Spring Load

0.376 0.333 0.179 2.772 1.333 1.988 2.698 1.394 1.884 0.992 1.902 0.451 2.930 1.932 2.749 1.426 1.848 0.274 2.514 2.385 1.351 2.700 2.666 1.225 2.274 2.959 0.577 0.116 0.111 0.247 0.004 0.000 0.000

SPRING2005 0.075 0.065 0.022 0.157 0.238 0.156 0.213 0.221 0.277 0.013 0.104 0.233 0.146 0.292 0.120 0.397 0.090 0.383 0.082 0.402 0.022 0.002 0.027 None None2006 0.154 0.202 None 0.599 0.802 0.085 0.687 0.844 0.079 0.727 0.802 0.286 0.911 0.794 0.220 0.828 0.791 0.170 0.620 1.067 0.059 0.909 1.264 0.842 1.371 0.016 0.023 0.083 0.004 None None2007 0.072 0.127 0.224 0.478 0.207 0.518 0.201 0.549 0.224 0.489 0.271 0.749 0.258 0.855 0.217 0.965 0.008 0.005 0.063 None None2008 0.199 0.124 0.179 1.451 0.487 1.988 1.409 0.513 1.884 1.044 0.412 1.082 1.293 0.732 1.351 0.791 0.710 0.539 0.723 0.877 0.326 0.005 0.005 0.051 None None2009 0.109 0.081 0.059 0.260 0.334 0.295 0.363 0.097 0.388 0.689 0.270 0.905 0.006 0.020 0.056 None None2010 0.071 0.132 0.130 0.306 0.148 0.318 0.174 0.526 0.199 0.793 0.037 0.079 0.247 None None2011 0.104 0.113 0.008 0.319 0.409 0.032 0.503 0.506 0.155 0.737 0.809 0.115 0.389 0.574 0.906 0.030 0.443 0.892 0.029 0.010 0.056 None None2012 0.020 0.104 0.104 0.422 0.124 0.552 0.143 0.628 0.109 1.069 0.012 0.006 0.054 None NoneAverage 0.101 0.118 0.067 0.608 0.501 1.037 0.409 0.445 0.665 0.383 0.542 0.149 0.419 0.458 0.388 0.463 0.630 0.170 0.484 0.667 0.705 0.412 0.800 0.284 0.397 0.886 0.326 0.017 0.019 0.080 0.004 0.000 0.000Min 0.020 0.065 0.008 0.157 0.238 0.085 0.104 0.213 0.032 0.201 0.277 0.013 0.104 0.233 0.097 0.143 0.292 0.170 0.115 0.389 0.059 0.090 0.383 0.030 0.082 0.402 0.326 0.005 0.002 0.027 0.004 0.000 0.000Max 0.199 0.202 0.179 1.451 0.802 1.988 1.409 0.844 1.884 0.727 0.802 0.286 1.044 0.794 1.082 0.828 0.809 0.170 1.293 1.067 1.351 0.909 1.264 0.539 0.842 1.371 0.326 0.037 0.079 0.247 0.004 0.000 0.0002008 Average w/o 4/22/08

0.023 0.051 0.129 0.190 0.120 0.213 0.842 0.348 0.354 0.073 0.300 0.518 0.600 0.130 0.582 0.802 0.011 0.004 0.004 0.044 0.000 0.000 0.000

Ave Yearly w/o 4/22/08 0.078 0.109 0.030 0.277 0.427 0.085 0.248 0.407 0.055 0.383 0.542 0.149 0.394 0.450 0.207 0.463 0.630 0.170 0.240 0.581 0.059 0.377 0.787 0.080 0.377 0.876 0.011 0.017 0.019 0.079 0.002 0.000 0.000

FALL2005 0.010 0.072 0.046 0.255 0.059 0.275 0.100 0.264 0.092 0.273 0.091 0.272 0.102 0.410 0.049 0.443 0.049 0.467 0.010 0.039 0.068 None None2006 0.022 0.088 0.068 0.334 0.088 0.348 0.058 0.364 0.090 0.549 0.102 0.691 0.084 0.716 0.005 0.015 0.082 None None2007 0.013 0.090 0.016 0.326 0.027 0.355 0.014 0.326 0.017 0.486 0.022 0.561 0.022 0.606 0.006 0.006 0.090 None None2008 0.056 0.069 0.019 0.025 0.250 0.025 0.269 0.039 0.306 0.031 0.276 0.035 0.297 0.020 0.376 0.032 0.459 0.021 0.448 0.001 0.012 0.045 None None2009 0.056 0.082 0.066 0.314 0.063 0.313 0.056 0.214 0.075 0.369 0.033 0.404 0.002 0.011 0.026 None None2010 0.010 0.077 0.037 0.314 0.043 0.294 0.041 0.356 0.043 0.482 0.034 0.440 0.001 0.027 0.041 None None2011 0.012 0.088 0.045 0.343 0.052 0.315 0.067 0.457 0.050 0.585 0.010 0.016 0.057 None None2012 0.007 0.046 0.022 0.179 0.039 0.191 0.038 0.330 0.037 0.360 0.035 0.340 0.002 0.003 0.045 None NoneAverage 0.023 0.076 0.019 0.039 0.291 0.000 0.046 0.300 0.000 0.069 0.285 0.000 0.049 0.294 0.000 0.054 0.342 0.000 0.057 0.407 0.000 0.051 0.494 0.000 0.040 0.489 0.000 0.005 0.016 0.057 0.000 0.000 0.000Min 0.007 0.046 0.019 0.016 0.250 0.000 0.022 0.179 0.000 0.039 0.264 0.000 0.014 0.191 0.000 0.035 0.272 0.000 0.017 0.214 0.000 0.022 0.360 0.000 0.021 0.340 0.000 0.001 0.003 0.026 0.000 0.000 0.000Max 0.056 0.090 0.019 0.068 0.334 0.000 0.088 0.355 0.000 0.100 0.306 0.000 0.092 0.364 0.000 0.091 0.457 0.000 0.102 0.549 0.000 0.102 0.691 0.000 0.084 0.716 0.000 0.010 0.039 0.090 0.000 0.000 0.000Notes:Measured Load = calculated using the measured concentration, or if not detected half the detection limit, on the day identified and the calculated or measured flow for the identified date.WQS Load = Load calculated using the measured hardness from a sample collected on the identified day and the measured or calculated flow rate for the station on the identified date, WQS equations are determined by station and date.Reduce = Load above the WQS load = Measured Load minus WQS LoadSpring = March and AprilFall = September through DecemberAverages do not include zero values; thus average reduction is based solely on events where the reduction is requiredAverage Calculations for a station (e.g., E-22) in other Appendices' tables may be skewed as concentrations from one sample date have been "surrogated" to represent the concentration for the day that most other stations were measured. These surrogate loads have been removed from this table/Appendix for averaging purposes

Numbers in italics were calculated using load reductions for different days

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Page 178: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

APPENDIX C-3

YEARLY AVERAGE COPPER LOAD CALCULATIONS AND COPPER

LOAD REDUCTION CALCULATIONS

Page 179: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Appendix C-3Yearly Average Copper Load Calculations by Station and Copper Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

1/14/2005 0.14 1.04 0.00 0.29 1.71 0.00 0.33 1.97 0.00 0.37 2.05 0.00 0.16 1.94 0.00 0.16 1.25 0.00 0.18 1.61 0.00 0.21 1.78 0.00 0.21 1.63 0.00 0.011 0.03 0.24 0.00 0.00 0.003/3/2005 0.39 1.98 0.00 0.19 1.97 0.00 0.19 1.99 0.00 0.02 0.12 0.00 0.00 0.003/10/2005 0.52 2.28 0.00 0.22 2.06 0.00 0.22 2.22 0.00 0.02 0.13 0.00 0.00 0.003/17/2005 0.68 1.01 0.00 0.76 1.71 0.00 0.93 1.92 0.00 0.94 2.16 0.00 0.36 2.18 0.00 0.36 1.35 0.00 0.18 1.90 0.00 0.47 2.11 0.00 0.21 2.17 0.00 0.067 0.02 0.13 0.00 0.00 0.003/24/2005 0.47 2.11 0.00 0.47 1.94 0.00 0.22 2.10 0.00 0.03 0.13 0.00 0.00 0.003/31/2005 0.64 2.23 0.00 0.58 2.17 0.00 0.53 2.29 0.00 0.03 0.17 0.00 0.00 0.004/3/2005 1.22 2.37 0.00 1.14 2.63 0.004/4/2005 2.50 3.17 0.00 1.68 2.14 0.004/5/2005 2.28 1.76 0.52 2.88 3.06 0.004/12/2005 1.83 1.21 0.62 2.31 2.25 0.06 2.47 2.45 0.03 2.74 2.82 0.00 1.45 2.81 0.00 1.38 1.71 0.00 0.88 2.57 0.00 1.73 3.01 0.00 1.64 2.82 0.00 0.142 0.06 0.41 0.00 0.00 0.005/23/2005 18.46 17.66 0.80 19.59 35.31 0.00 20.85 35.57 0.00 21.15 36.60 0.00 20.57 35.61 0.00 14.59 21.39 0.00 16.61 26.15 0.00 20.78 33.32 0.00 19.35 40.00 0.00 0.338 4.59 4.70 0.00 0.00 0.006/28/2005 1.62 1.59 1.59 1.81 5.057/29/2005 1.08 0.91 1.00 0.52 0.378/25/2005 0.61 0.58 0.24 0.61 0.129/12/2005 0.16 1.42 0.00 0.44 2.28 0.00 0.51 2.50 0.00 0.46 2.51 0.00 0.36 2.43 0.00 0.39 1.50 0.00 0.20 2.10 0.00 0.25 2.00 0.00 0.25 2.15 0.00 0.041 0.09 0.36 0.00 0.00 0.009/22/2005 0.23 0.43 0.43 0.24 0.1110/18/2005 0.24 1.55 0.00 0.73 2.74 0.00 0.76 3.03 0.00 1.03 2.79 0.00 0.75 3.01 0.00 0.76 1.87 0.00 0.75 2.66 0.00 1.18 3.46 0.00 1.03 3.55 0.00 0.012 0.44 0.62 0.00 0.00 0.0010/25/2005 0.76 0.73 0.67 0.80 0.501/31/2006 0.21 1.06 0.00 0.97 1.87 0.00 0.71 2.18 0.00 0.89 1.93 0.00 0.34 1.74 0.00 0.44 2.00 0.00 0.35 2.11 0.00 0.049 0.05 0.18 0.00 0.00 0.003/9/2006 4.32 4.35 0.00 1.91 4.57 0.00 2.68 2.59 0.09 2.17 3.60 0.00 2.81 4.98 0.00 6.41 5.01 1.41 0.17 0.48 0.00 0.00 1.413/15/2006 2.96 2.96 1.79 2.37 0.183/16/2006 0.98 2.89 0.00 1.04 3.00 0.00 2.08 3.14 0.00 0.08 0.42 0.00 0.00 0.003/22/2006 2.33 2.72 0.00 2.20 2.71 0.00 2.20 1.67 0.53 2.22 2.36 0.00 0.04 0.19 0.003/23/2006 0.91 1.51 0.00 1.27 2.61 0.00 1.49 2.88 0.00 0.91 2.88 0.00 0.76 2.44 0.00 1.07 3.00 0.00 0.89 3.21 0.00 0.086 0.08 0.42 0.00 0.00 0.003/29/2006 2.93 3.04 1.82 2.49 0.283/30/2006 1.41 3.06 0.00 1.77 3.14 0.00 1.44 3.42 0.00 0.09 0.49 0.00 0.00 0.004/5/2006 4.96 6.55 0.00 4.52 6.39 0.00 4.04 4.04 0.00 4.26 5.16 0.00 0.24 0.53 0.004/6/2006 8.54 8.17 0.38 8.99 8.17 0.82 7.39 9.24 0.00 0.26 0.76 0.00 0.45 0.004/12/2006 10.35 9.65 6.21 7.89 0.774/13/2006 16.69 14.69 2.00 17.94 14.54 3.41 14.95 17.29 0.00 0.64 1.12 0.00 1.41 0.004/19/2006 23.79 15.06 8.73 24.62 15.28 9.34 24.62 9.39 15.24 22.12 11.73 10.39 0.75 0.81 0.004/20/2006 6.53 6.76 0.00 15.30 13.32 1.99 15.32 14.02 1.31 15.23 14.16 1.07 13.20 11.05 2.15 23.67 16.13 7.54 21.69 15.11 6.58 0.063 0.54 0.75 0.00 6.47 5.514/26/2006 19.36 19.52 11.67 14.66 0.985/22/2006 6.82 18.03 0.00 7.96 34.69 0.00 8.09 35.61 0.00 8.86 36.93 0.00 12.71 26.95 0.00 16.54 36.92 0.00 14.55 38.82 0.00 0.093 5.67 4.61 1.06 0.00 0.005/23/2006 22.39 38.42 0.00 24.77 39.52 0.00 25.22 23.45 1.77 28.20 28.25 0.00 12.79 11.58 1.209/27/2006 0.31 1.86 0.00 0.33 3.66 0.00 0.37 3.85 0.00 0.37 4.01 0.00 0.42 3.37 0.00 0.59 4.28 0.00 0.59 4.42 0.00 0.001 0.16 0.65 0.00 0.00 0.0010/23/2006 0.32 1.64 0.00 0.70 3.29 0.00 0.38 3.52 0.00 0.37 3.60 0.00 0.42 3.31 0.00 0.58 4.32 0.00 0.58 4.42 0.00 0.012 0.34 0.55 0.00 0.00 0.001/29/2007 0.14 1.29 0.00 0.37 2.01 0.00 0.41 2.30 0.00 0.37 2.23 0.00 0.18 2.13 0.00 0.22 2.49 0.00 0.22 2.55 0.00 0.026 0.02 0.13 0.00 0.00 0.003/2/2007 0.23 1.39 0.00 0.13 1.31 0.00 0.13 1.41 0.00 0.02 0.11 0.00 0.00 0.003/13/2007 0.60 2.31 0.00 0.61 2.36 0.00 0.24 2.49 0.00 0.06 0.35 0.00 0.00 0.003/14/2007 1.25 2.61 0.00 1.00 2.76 0.00 0.0103/20/2007 1.70 2.06 0.00 2.49 3.80 0.00 2.74 4.23 0.00 2.25 4.27 0.00 2.20 3.64 0.00 2.63 4.38 0.00 2.14 4.79 0.00 0.011 0.20 0.43 0.00 0.00 0.003/21/2007 2.30 3.85 0.00 2.34 4.13 0.00 0.0143/27/2007 2.82 4.70 0.00 3.21 4.93 0.00 2.92 5.58 0.00 0.23 0.43 0.00 0.00 0.003/28/2007 3.50 4.89 0.00 3.32 5.06 0.00 0.0454/3/2007 2.05 4.54 0.00 2.62 4.70 0.00 2.61 5.03 0.00 0.21 0.46 0.00 0.00 0.004/4/2007 2.52 4.54 0.00 2.60 4.78 0.00 0.0384/10/2007 5.02 6.47 0.00 5.96 7.07 0.00 5.65 7.78 0.00 0.27 0.54 0.00 0.00 0.004/11/2007 5.00 5.57 0.00 5.02 6.14 0.00 0.0214/17/2007 2.14 3.06 0.00 3.96 5.97 0.00 4.18 6.37 0.00 4.08 6.59 0.00 4.08 5.36 0.00 5.12 7.19 0.00 4.57 8.02 0.00 0.043 0.12 0.53 0.00 0.00 0.004/18/2007 5.59 7.41 0.00 5.48 7.59 0.00 0.0394/24/2007 5.42 9.43 0.00 6.72 10.20 0.00 6.41 11.25 0.00 0.45 0.73 0.00 0.00 0.004/26/2007 5.94 8.38 0.00 5.80 8.66 0.00 0.0449/25/2007 0.27 1.87 0.00 0.27 3.36 0.00 0.31 3.76 0.00 0.29 3.38 0.00 0.34 3.01 0.00 0.47 3.62 0.00 0.47 3.78 0.00 0.003 0.32 0.79 0.00 0.00 0.0010/16/2007 0.82 1.82 0.00 0.25 3.14 0.00 0.29 3.39 0.00 0.26 3.17 0.00 0.32 2.76 0.00 0.43 3.28 0.00 0.43 3.55 0.00 0.010 0.10 0.47 0.00 0.00 0.001/28/2008 0.11 1.51 0.00 0.14 1.84 0.00 0.13 1.73 0.00 0.15 1.31 0.00 0.17 1.40 0.00 0.17 1.55 0.00 0.001 0.03 0.15 0.00 0.00 0.003/4/2008 0.61 1.77 0.00 0.45 1.70 0.00 0.43 1.87 0.00 0.12 0.18 0.00 0.00 0.003/11/2008 0.45 1.72 0.00 0.52 1.57 0.00 0.49 1.70 0.00 0.12 0.17 0.00 0.00 0.003/18/2008 0.66 1.70 0.00 0.68 1.72 0.00 0.49 1.80 0.00 0.11 0.17 0.00 0.00 0.003/25/2008 0.35 1.05 0.00 0.44 1.83 0.00 0.54 2.09 0.00 0.35 2.06 0.00 0.25 1.72 0.00 0.32 1.94 0.00 0.36 2.11 0.00 0.003 0.04 0.19 0.00 0.00 0.004/2/2008 0.77 2.51 0.004/8/2008 0.83 2.34 0.00 0.91 2.56 0.00 0.77 2.71 0.00 0.06 0.24 0.00 0.00 0.004/9/2008 2.04 2.63 0.004/15/2008 2.51 4.57 0.00 3.29 4.84 0.00 2.60 5.51 0.00 0.09 0.43 0.00 0.00 0.004/16/2008 6.17 5.95 0.224/22/2008 7.22 4.02 3.20 12.92 7.79 5.12 13.14 8.18 4.96 10.91 8.45 2.46 11.29 6.87 4.42 14.00 8.97 5.03 12.32 10.01 2.31 0.029 0.35 0.72 0.00 2.57 0.004/23/2008 14.80 12.80 2.004/29/2008 11.86 9.94 1.93 16.17 10.88 5.28 13.86 12.12 1.74 0.46 0.72 0.00 3.36 0.005/1/2008 21.85 19.29 2.565/28/2008 7.68 19.05 0.00 14.07 37.98 0.00 14.19 40.00 0.00 14.40 40.15 0.00 15.37 39.99 0.00 16.56 24.77 0.00 21.68 41.64 0.00 0.116 4.17 4.36 0.00 0.006/24/2008 5.66 21.73 0.00 7.30 43.56 0.00 9.14 44.33 0.00 7.42 44.97 0.00 7.31 44.33 0.00 7.31 27.45 0.00 18.86 42.12 0.00 0.029 7.89 4.93 2.97 0.007/29/2008 0.89 5.56 0.00 2.56 11.99 0.00 1.45 11.99 0.00 2.06 11.98 0.00 2.16 12.12 0.00 1.73 7.40 0.00 3.90 12.13 0.00 0.007 2.02 2.03 0.00 0.008/26/2008 0.64 2.43 0.00 0.90 4.49 0.00 0.65 4.78 0.00 0.005 0.33 0.67 0.008/27/2008 0.69 4.47 0.00 0.58 4.47 0.00 0.62 2.77 0.00 0.98 4.64 0.00 0.009/17/2008 0.13 1.66 0.00 0.50 2.85 0.00 0.46 3.05 0.00 0.001 0.11 0.33 0.009/18/2008 0.50 3.28 0.00 0.43 3.20 0.00 0.38 1.94 0.00 0.49 3.34 0.00 0.009/29/2008 0.18 1.28 0.00 0.38 2.24 0.00 0.21 2.46 0.00 0.20 2.49 0.00 0.23 2.16 0.00 0.29 2.46 0.00 0.29 2.57 0.00 0.001 0.08 0.35 0.00 0.00 0.0010/20/2008 0.17 1.31 0.00 0.41 2.14 0.00 0.36 2.42 0.00 0.25 2.40 0.00 0.19 2.12 0.00 0.31 2.31 0.00 0.34 2.37 0.00 0.000 0.10 0.32 0.00 0.00 0.0010/21/2008 0.11 1.48 0.00 0.31 2.44 0.00 0.35 2.70 0.00 0.001 0.06 0.27 0.0010/22/2008 0.41 2.68 0.00 0.24 2.60 0.00 0.24 1.61 0.00 0.31 2.58 0.00 0.0010/29/2008 0.07 3.11 0.0011/11/2008 0.29 2.63 0.0012/9/2008 0.21 2.23 0.001/8/2009 0.33 2.59 0.00 0.23 2.54 0.001/14/2009 0.18 2.29 0.002/11/2009 0.00 2.06 0.002/19/2009 0.13 0.96 0.00 0.35 1.76 0.00 0.20 1.86 0.00 0.24 1.70 0.00 0.000 0.003/3/2009 1.02 2.10 0.003/10/2009 0.41 2.29 0.003/11/2009 0.41 1.06 0.00 1.01 1.81 0.00 0.58 1.89 0.00 0.44 2.23 0.00 0.004 0.10 0.24 0.00 0.003/17/2009 0.57 2.25 0.003/20/2009 1.52 1.37 0.16 1.76 2.78 0.00 1.23 2.89 0.00 0.0053/24/2009 2.22 4.06 0.003/25/2009 1.19 1.53 0.00 1.84 3.12 0.00 1.59 3.19 0.00 1.98 3.48 0.00 0.004 0.19 0.38 0.00 0.004/7/2009 1.99 3.16 0.00

Reduction Beyond 5a

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Appendix C-3Yearly Average Copper Load Calculations by Station and Copper Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

Reduction Beyond 5a

4/8/2009 1.66 1.66 0.00 2.26 3.57 0.00 2.22 4.03 0.00 2.37 4.24 0.00 0.011 0.17 0.43 0.00 0.004/14/2009 4.04 5.87 0.004/20/2009 2.63 2.66 0.00 4.43 5.54 0.00 4.21 5.84 0.00 4.87 6.21 0.00 0.024 0.31 0.52 0.00 0.004/21/2009 5.63 9.20 0.004/28/2009 13.51 14.45 0.005/12/2009 21.13 30.44 0.006/9/2009 17.65 36.00 0.007/14/2009 2.27 8.53 0.008/11/2009 1.01 4.17 0.009/16/2009 0.67 3.44 0.009/23/2009 0.26 1.70 0.00 0.75 3.15 0.00 0.70 3.12 0.00 0.80 3.01 0.00 0.005 0.07 0.19 0.00 0.0010/13/2009 0.54 2.36 0.0011/10/2009 0.40 2.00 0.0012/8/2009 0.28 2.28 0.0012/30/2009 0.40 2.07 0.0012/31/2009 0.14 1.26 0.00 0.42 1.45 0.00 0.16 1.57 0.001/2/2010 0.35 1.83 0.001/3/2010 0.32 1.34 0.001/4/2010 0.11 0.96 0.00 0.13 1.15 0.00 0.13 1.29 0.001/5/2010 0.15 1.33 0.001/6/2010 0.35 1.30 0.00 0.18 2.04 0.00 0.44 2.19 0.001/7/2010 0.15 1.38 0.001/8/2010 0.63 1.24 0.00 0.12 1.11 0.00 0.19 1.18 0.001/9/2010 0.12 1.12 0.001/10/2010 0.16 1.48 0.001/11/2010 0.55 1.04 0.00 0.15 1.39 0.00 0.22 1.46 0.001/12/2010 0.28 1.38 0.00 0.14 1.44 0.001/13/2010 0.65 1.27 0.00 0.14 1.30 0.00 0.39 1.45 0.001/14/2010 0.14 1.27 0.001/15/2010 0.37 0.97 0.00 0.27 1.40 0.00 0.49 1.30 0.001/16/2010 0.13 1.21 0.001/17/2010 0.16 1.46 0.001/18/2010 0.37 0.91 0.00 0.12 1.11 0.00 0.30 1.18 0.001/19/2010 0.11 1.04 0.001/20/2010 0.25 0.85 0.00 0.11 1.06 0.00 0.42 1.10 0.001/21/2010 0.22 1.03 0.001/22/2010 0.36 0.92 0.00 0.12 1.12 0.00 0.14 1.23 0.001/23/2010 0.13 1.25 0.001/24/2010 0.11 1.06 0.001/25/2010 0.31 0.72 0.00 0.21 0.89 0.001/27/2010 0.44 1.01 0.00 0.26 1.45 0.002/3/2010 0.63 0.92 0.00 0.39 1.37 0.002/9/2010 0.19 1.07 0.002/20/2010 0.62 1.16 0.002/26/2010 0.37 1.28 0.003/5/2010 0.67 1.42 0.003/6/2010 0.42 1.51 0.00 0.30 1.43 0.00 0.23 1.20 0.00 0.005 0.00 0.00 0.00 0.003/9/2010 0.30 1.39 0.003/17/2010 0.45 1.84 0.00 0.31 1.80 0.00 0.16 1.77 0.00 0.010 0.00 0.00 0.00 0.003/18/2010 0.58 2.15 0.003/22/2010 0.49 2.26 0.003/26/2010 0.48 1.93 0.003/30/2010 0.67 2.02 0.004/1/2010 0.97 2.64 0.004/2/2010 0.74 2.23 0.00 0.60 2.18 0.00 0.53 2.36 0.00 0.008 0.00 0.00 0.00 0.004/5/2010 0.68 2.03 0.004/7/2010 0.65 2.01 0.004/9/2010 2.68 0.78 2.83 0.004/14/2010 9.03 6.43 2.604/15/2010 3.35 2.56 0.79 4.97 6.82 0.00 4.78 7.57 0.00 6.01 7.36 0.00 5.79 8.30 0.00 0.172 1.42 1.77 0.00 0.00 0.004/16/2010 8.86 9.57 0.004/21/2010 18.67 18.20 0.474/27/2010 7.76 8.44 0.005/4/2010 6.33 9.91 0.005/11/2010 12.96 13.61 0.005/18/2010 17.80 18.42 0.005/25/2010 16.61 27.98 0.006/1/2010 29.81 43.68 0.007/19/2010 2.28 6.13 0.00 1.93 3.29 0.00 2.05 6.43 0.00 0.007/22/2010 2.42 8.52 0.008/13/2010 1.62 4.82 0.00 1.54 3.68 0.00 2.45 5.01 0.00 0.008/19/2010 1.09 4.52 0.009/10/2010 0.63 3.11 0.00 0.77 2.24 0.00 1.17 3.35 0.00 0.009/24/2010 0.20 1.62 0.00 0.71 3.06 0.00 0.51 3.08 0.00 0.71 2.78 0.00 1.10 2.94 0.00 0.001 0.36 0.29 0.07 0.00 0.0010/13/2010 0.69 2.97 0.00 2.20 0.37 2.97 0.00 0.0010/28/2010 0.77 2.29 0.0011/9/2010 0.83 2.49 0.0011/22/2010 0.23 2.21 0.00 0.22 1.67 0.00 0.28 2.14 0.00 0.0012/14/2010 0.45 2.54 0.001/11/2011 0.71 2.30 0.001/17/2011 0.86 2.19 0.00 0.86 1.88 0.00 1.20 2.98 0.00 0.002/16/2011 0.25 2.12 0.00 0.20 1.79 0.00 0.23 2.22 0.00 0.002/22/2011 0.63 2.45 0.003/1/2011 0.44 2.64 0.003/7/2011 0.56 2.33 0.00 0.55 2.31 0.00 1.21 2.16 0.00 1.73 2.50 0.00 0.024 0.11 0.11 0.00 0.00 0.003/8/2011 1.13 2.56 0.003/15/2011 1.10 2.68 0.003/21/2011 1.72 1.50 0.22 2.05 3.03 0.00 1.58 3.13 0.00 2.03 3.39 0.00 0.038 0.16 0.23 0.00 0.003/22/2011 2.97 3.66 0.003/28/2011 0.82 2.77 0.00 0.76 2.33 0.00 1.07 3.05 0.00 0.00 0.003/29/2011 3.21 3.21 0.004/4/2011 2.33 1.95 0.38 2.99 4.20 0.00 2.99 4.74 0.00 6.87 4.82 2.06 0.074 0.42 0.59 0.00 2.06 0.004/5/2011 4.40 5.33 0.004/12/2011 7.91 7.04 0.874/18/2011 2.84 3.38 0.00 4.94 7.01 0.00 6.81 7.45 0.00 7.17 8.57 0.00 0.158 0.69 0.59 0.10 0.00

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Appendix C-3Yearly Average Copper Load Calculations by Station and Copper Load Reduction Calculations

E- 3 E- 3 E- 3 E- 5 E- 5 E- 5 E-10 E-10 E-10 E-11 E-11 E-11 E-12A E-12A E-12A E-13 E-13 E-13 E-13B E-13B E-13B E-15 E-15 E-15 E-22 E-22 E-22 T-10 T-18 T-18 T-18

SAMPDAYMeasured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadWQS Load Reduce Measured

LoadMeasured

LoadWQS Load Reduce For E-15 For E-22

Reduction Beyond 5a

4/19/2011 13.26 10.39 2.874/22/2011 9.79 9.87 0.00 9.70 7.21 2.49 13.29 10.35 2.94 2.944/26/2011 14.06 9.43 4.645/3/2011 7.57 7.07 0.505/4/2011 4.36 2.99 1.37 4.79 6.05 0.00 4.82 6.31 0.00 5.04 6.82 0.00 0.075 0.19 0.41 0.00 0.005/10/2011 33.00 27.44 5.565/31/2011 15.75 39.51 0.00 14.96 25.00 0.00 19.62 42.95 0.00 0.006/14/2011 30.24 64.89 0.006/15/2011 1.57 54.21 0.00 1.57 37.20 0.00 2.70 56.23 0.00 0.007/12/2011 39.28 46.11 0.007/20/2011 0.66 24.16 0.00 0.66 16.08 0.00 1.13 22.15 0.00 0.008/17/2011 0.15 6.35 0.00 0.15 5.03 0.00 0.24 7.24 0.00 0.009/21/2011 0.08 3.76 0.00 0.70 3.23 0.00 0.12 3.92 0.00 0.0010/11/2011 0.24 1.82 0.00 0.57 3.43 0.00 0.28 3.43 0.00 0.42 3.89 0.00 0.008 0.31 0.40 0.00 0.0010/19/2011 0.07 3.66 0.00 0.07 3.16 0.00 0.90 3.83 0.00 0.0011/17/2011 0.04 2.46 0.00 0.04 1.97 0.00 0.06 3.03 0.00 0.0012/14/2011 0.04 2.13 0.00 0.04 1.80 0.00 0.05 2.21 0.00 0.001/18/2012 0.04 1.90 0.00 0.04 1.73 0.00 0.05 2.19 0.00 0.002/15/2012 0.03 1.69 0.00 0.03 1.38 0.00 0.04 1.51 0.00 0.003/12/2012 0.30 0.99 0.00 0.48 1.97 0.00 0.35 1.95 0.00 0.005 0.03 0.15 0.003/19/2012 0.70 2.48 0.00 0.64 1.57 0.00 0.75 2.29 0.00 0.003/26/2012 1.06 2.25 0.00 1.54 4.79 0.00 1.88 5.32 0.00 2.28 6.11 0.00 0.034 0.20 0.37 0.00 0.004/3/2012 2.69 6.95 0.004/10/2012 1.86 2.94 0.00 2.28 6.70 0.00 2.18 6.82 0.00 3.48 8.01 0.00 0.036 0.54 0.67 0.00 0.004/11/2012 0.20 10.10 0.00 0.20 6.16 0.00 0.34 10.23 0.00 0.004/17/2012 1.89 5.88 0.005/16/2012 0.31 15.42 0.00 0.31 8.50 0.00 0.52 14.32 0.00 0.006/27/2012 0.11 3.22 0.00 0.11 3.17 0.00 0.17 3.95 0.00 0.007/24/2012 0.06 2.54 0.00 2.20 2.728/15/2012 0.07 2.71 0.00 0.06 2.61 0.00 0.10 2.89 0.00 0.009/13/2012 0.05 2.11 0.00 0.05 2.18 0.00 0.08 2.70 0.00 0.0010/11/2012 0.03 1.81 0.00 0.07 1.52 0.00 0.04 1.63 0.00 0.0010/18/2012 0.13 0.94 0.00 0.16 1.82 0.00 0.15 1.91 0.00 0.20 1.59 0.00 0.20 1.96 0.00 0.002 0.06 0.31 0.00 0.00 0.0011/15/2012 0.03 1.88 0.00 0.04 1.66 0.00 0.04 2.02 0.00 0.0012/14/2012 0.03 1.71 0.00 1.83 2.28

All Sampling Events Equal WeightAverage 2.03 3.48 0.89 3.47 8.47 2.39 2.88 6.41 2.10 4.74 10.39 8.73 2.69 6.85 2.86 2.51 5.30 3.35 3.65 5.75 5.65 2.59 5.64 3.87 4.54 6.89 2.45 0.037 0.76 0.83 1.08 2.75 3.46Maximum 18.46 21.73 3.20 19.59 43.56 5.12 20.85 44.33 4.96 23.79 44.97 8.73 24.77 54.21 9.34 25.22 37.20 15.24 28.20 28.25 10.39 23.67 56.23 7.54 39.28 64.89 6.58 0.338 12.79 11.58 2.97 6.47 5.51Max Measured Spring Load

7.22 6.76 3.20 15.30 13.32 5.12 15.32 14.02 4.96 23.79 19.36 8.73 24.62 19.52 9.34 24.62 11.67 15.24 22.12 14.66 10.39 23.67 16.13 7.54 21.69 18.20 6.58 0.172 1.42 1.77 0.10 6.47 5.51

SPRING2005 1.60 1.33 0.57 1.98 2.34 0.06 1.70 2.18 0.03 2.06 2.72 0.64 2.26 1.14 1.73 0.53 2.23 0.70 2.23 0.59 2.32 0.104 0.03 0.18 None None2006 3.72 4.14 8.29 7.96 1.99 8.41 8.45 1.31 8.85 8.04 8.73 7.70 7.85 3.20 8.38 4.90 3.96 7.45 6.37 6.27 8.18 7.57 3.92 7.84 8.06 4.00 0.074 0.29 0.58 2.77 3.462007 1.92 2.56 3.22 4.89 3.67 5.32 3.65 5.59 2.81 4.96 3.14 4.50 3.37 5.27 3.08 5.79 0.029 0.19 0.45 None None2008 3.79 2.54 3.20 6.68 4.81 5.12 6.84 5.13 4.96 3.52 4.07 2.19 5.77 4.29 4.42 4.54 4.27 5.16 4.59 5.14 1.57 0.016 0.17 0.35 2.96 None2009 1.48 1.66 0.16 2.26 3.36 1.97 3.57 2.41 4.04 3.67 5.42 0.010 0.19 0.39 None None2010 3.35 2.56 0.79 1.65 3.10 1.50 3.13 1.73 3.17 3.76 4.77 1.53 0.049 1.42 1.77 None None2011 2.30 2.28 0.30 2.64 4.14 3.76 5.05 5.23 4.77 2.49 1.21 2.16 5.36 5.44 2.50 5.39 5.22 2.79 0.074 0.34 0.38 0.10 2.50 None2012 1.07 2.06 1.43 4.49 1.41 5.64 0.42 3.86 1.71 6.66 0.025 0.26 0.40 None NoneAverage 2.40 2.39 1.00 5.04 5.00 2.39 3.57 4.52 2.10 4.85 5.45 8.73 2.91 4.57 2.70 3.79 3.82 3.23 3.62 3.91 5.35 3.50 4.83 3.86 4.13 5.25 2.47 0.048 0.36 0.56 0.10 2.75 3.46Min 1.07 1.33 0.16 1.98 2.34 0.06 1.43 2.18 0.03 2.06 2.72 8.73 0.64 2.26 2.19 0.42 1.73 2.49 0.53 2.16 4.42 0.70 2.23 2.50 0.59 2.32 1.53 0.010 0.03 0.18 0.10 2.50 3.46Max 3.79 4.14 3.20 8.29 7.96 5.12 8.41 8.45 4.96 8.85 8.04 8.73 7.70 7.85 3.20 8.38 4.90 3.96 7.45 6.37 6.27 8.18 7.57 5.16 7.84 8.06 4.00 0.104 1.42 1.77 0.10 2.96 3.462008 Average w/o 4/22/08

0.35 1.05 0.44 1.83 0.54 2.09 2.47 3.44 0.64 0.25 1.72 3.19 3.60 1.76 3.89 4.70 0.57 0.003 0.14 0.30 0.00 1.12 0.00

Ave Yearly w/o 4/22/08 1.97 2.20 0.45 3.48 4.25 1.02 2.79 4.14 0.67 4.85 5.45 8.73 2.78 4.49 1.92 3.79 3.82 3.23 2.52 3.40 6.27 3.33 4.75 2.73 4.03 5.18 2.22 0.046 0.36 0.56 0.05 2.13 1.73

FALL2005 0.20 1.49 0.58 2.51 0.63 2.77 0.62 2.65 0.57 2.72 0.56 1.68 0.50 2.38 0.71 2.73 0.64 2.85 0.026 0.28 0.49 None None2006 0.32 1.75 0.52 3.48 0.37 3.68 0.37 3.81 0.42 3.34 0.58 4.30 0.58 4.42 0.007 0.25 0.60 None None2007 0.55 1.84 0.26 3.25 0.30 3.57 0.28 3.27 0.33 2.89 0.45 3.45 0.45 3.66 0.006 0.21 0.63 None None2008 0.15 1.43 0.40 2.42 0.34 2.66 0.45 2.98 0.28 2.67 0.31 1.78 0.21 2.14 0.35 2.67 0.24 2.58 0.001 0.09 0.32 None None2009 0.26 1.70 0.75 3.15 0.70 3.12 0.14 1.26 0.54 2.17 0.41 2.33 0.005 0.07 0.19 None None2010 0.20 1.62 0.71 3.06 0.52 2.84 0.49 2.04 0.63 2.81 0.79 2.56 0.001 0.36 0.29 0.07 None None2011 0.24 1.82 0.57 3.43 0.10 3.09 0.21 2.54 0.31 3.38 0.008 0.31 0.40 None None2012 0.13 0.94 0.16 1.82 0.06 1.89 0.05 1.80 0.09 2.05 0.20 1.96 0.002 0.06 0.31 None NoneAverage 0.25 1.57 0.00 0.44 2.91 0.00 0.48 3.02 0.00 0.54 2.82 0.00 0.36 2.93 0.00 0.33 1.97 0.00 0.32 2.40 0.00 0.46 2.95 0.00 0.47 2.91 0.00 0.007 0.20 0.40 0.07 0.00 0.00Min 0.13 0.94 0.00 0.26 2.42 0.00 0.16 1.82 0.00 0.45 2.65 0.00 0.06 1.89 0.00 0.05 1.68 0.00 0.14 1.26 0.00 0.09 2.05 0.00 0.20 1.96 0.00 0.001 0.06 0.19 0.07 0.00 0.00Max 0.55 1.84 0.00 0.58 3.48 0.00 0.75 3.68 0.00 0.62 2.98 0.00 0.70 3.81 0.00 0.56 2.54 0.00 0.50 3.34 0.00 0.71 4.30 0.00 0.79 4.42 0.00 0.026 0.36 0.63 0.07 0.00 0.00Notes:Measured Load = calculated using the measured concentration, or if not detected half the detection limit, on the day identified and the calculated or measured flow for the identified date.WQS Load = Load calculated using the measured hardness from a sample collected on the identified day and the measured or calculated flow rate for the station on the identified date, WQS equations are determined by station and date.Reduce = Load above the WQS load = Measured Load minus WQS LoadSpring = March and AprilFall = September through DecemberAverages do not include zero values; thus average reduction is based solely on events where the reduction is requiredAverage Calculations for a station (e.g., E-22) in other Appendices' tables may be skewed as concentrations in other tables from one sample date have been "surrogated" to represent the concentration for the day that most other stations were measured. These surrogate loads have been removed from this table/Appendix for averaging purposes

Numbers in italics were calculated using load reductions for different days

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APPENDIX D

SEGMENT LOADING

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APPENDIX D-1

ZINC LOADING (LBS/DAY) ANALYSIS BY SEGMENT

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

1/14/2005 0.9 13.6 13.7 0.02 21.8 20.4 18.8 19.5 3.3 21.2 27.6 293/3/2005 43.7 2.4 36.8 27.1 273/10/2005 43.7 2.7 44.4 39.9 303/17/2005 20.7 50.5 48.0 7.2 70.5 51.7 40.7 44.2 2.9 44.6 36.1 293/24/2005 38.9 2.5 42.1 35.5 303/31/2005 53.6 3.2 53.2 41.6 314/3-5/05 18.2 56.2 80.8 75.1 59.8 51.4 414/12/2005 17.7 92.3 83.2 14.5 125.4 108.0 90.7 95.4 11.7 107.2 85.2 405/23/2005 365.4 207.6 187.6 14.0 215.7 214.0 175.1 199.4 17.6 200.7 200.7 7626/28/2005 79.5 60.5 62.1 58.0 6.8 2957/29/2005 30.0 27.7 24.9 24.7 1.8 848/25/2005 28.1 24.3 19.0 19.0 1.4 459/12/2005 2.5 18.8 22.4 6.1 24.7 26.7 23.2 24.2 1.4 20.0 16.5 339/22/2005 16.7 16.0 14.0 14.2 1.5 4010/18/2005 1.7 28.1 27.9 1.5 33.3 35.0 32.4 36.1 2.4 37.2 33.4 5010/25/2005 28.5 26.8 23.3 25.7 2.3 591/31/2006 1.8 13.8 30.0 5.4 30.6 28.4 2.3 30.1 25.4 273/9/2006 298.8 280.4 219.8 227.7 8.4 300.9 305.8 593/16/2006 99.9 145.7 94.4 102.2 8.3 121.7 121.7 383/23/2006 11.0 106.7 103.1 8.7 111.3 109.5 107.4 104.9 8.3 113.2 91.8 393/30/2006 133.8 138.3 120.2 120.7 10.4 147.0 120.3 424/6/2006 338.7 384.4 305.1 339.8 17.0 399.5 319.6 1134/12/2006 288.4 281.6 313.8 338.5 6.2 427.4 347.3 1494/20/2006 57.0 229.6 223.9 5.8 310.9 316.4 351.5 253.3 4.5 473.3 414.1 2174/26/2006 305.8 283.7 300.3 303.8 4.7 3095/22/2006 40.9 79.6 73.2 5.7 115.5 197.3 6.2 125.7 119.1 7139/27/2006 1.5 19.6 17.8 1.4 26.4 28.4 2.3 28.1 32.2 6910/23/2006 1.7 40.2 33.8 4.1 36.7 45.8 5.6 47.4 39.3 681/29/2007 1.2 11.8 15.4 6.7 31.1 26.4 3.0 29.9 23.7 303/2/2007 14.7 2.1 17.6 13.8 203/13/2007 43.6 2.2 57.1 56.2 6.5 58.7 45.9 323/20/2007 19.6 78.9 81.7 3.6 59.2 110.5 119.7 4.9 120.7 99.5 663/27/2007 66.1 5.8 88.1 116.2 4.2 137.0 117.0 754/3/2007 53.3 4.6 69.6 89.8 5.5 108.0 96.2 694/10/2007 82.8 0.3 108.0 118.4 5.9 152.3 131.4 1084/17/2007 23.1 80.4 84.1 4.5 109.0 110.1 119.1 4.6 138.4 121.1 1094/24/2007 105.9 6.0 125.3 112.0 5.5 142.8 133.9 1629/25/2007 1.7 17.1 26.9 3.0 21.7 23.1 2.9 22.3 19.1 5310/16/2007 2.1 15.6 15.2 2.9 18.1 22.3 2.2 21.9 18.0 491/28/2008 6.4 13.0 1.3 13.2 13.2 2.0 16.2 12.7 243/4/2008 37.0 2.2 29.2 22.8 253/11/2008 30.4 2.3 25.9 20.2 233/18/2008 28.8 2.5 32.4 26.4 233/25/2008 3.2 58.2 46.8 2.4 42.8 40.6 2.3 41.8 32.5 284/8/2008 134.3 4.0 148.3 110.2 314/15/2008 337.7 7.6 385.5 256.5 594/22/2008 125.2 661.5 653.8 3.4 653.4 692.3 8.3 740.6 646.5 1214/29/2008 399.7 18.4 507.0 411.2 1695/28/2008 26.9 88.9 106.5 13.0 168.0 173.4 193.2 11.2 203.2 730

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

6/24/2008 23.5 55.8 73.1 7.3 78.8 91.4 82.2 9.2 94.3 8467/29/2008 5.9 14.8 18.8 4.4 25.0 30.3 28.8 4.2 34.2 2678/27/2008 1.8 12.8 14.3 1.3 22.2 23.7 18.7 2.6 22.8 729/18/2008 1.0 6.6 11.1 1.2 17.7 18.8 15.9 3.4 16.6 449/29/2008 2.9 12.0 12.1 0.4 20.6 21.7 5.2 19.4 11.5 3710/20/2008 0.7 9.5 11.3 0.3 16.4 15.1 5.9 17.6 15.5 3210/22/2008 1.0 5.2 10.4 1.1 16.2 18.2 17.4 4.0 20.2 341/8/2009 1.1 11.4 17.3 19.2 322/19/2009 1.1 18.6 1.0 26.0 28.6 20.3 233/11/2009 4.3 42.0 2.3 56.3 3.8 53.9 31.5 253/20/2009 15.7 68.3 2.0 74.7 50.2 403/25/2009 20.9 91.6 3.7 93.7 4.6 109.3 102.5 474/8/2009 32.7 98.5 4.4 126.0 5.6 141.5 103.1 544/20/2009 38.7 149.4 3.7 159.7 5.7 197.4 103.9 919/23/2009 1.9 17.3 1.1 25.9 2.2 25.0 23.2 473/6/2010 17.7 3.2 19.2 18.5 18.4 183/17/2010 53.9 5.3 30.2 27.8 29.4 234/2/2010 23.3 7.0 41.5 45.1 51.8 314/15/2010 25.4 125.0 48.8 186.6 28.5 204.3 205.4 1239/24/2010 2.0 16.1 0.6 22.8 7.8 26.1 26.0 413/7/2011 28.9 8.2 35.6 44.1 2.5 47.4 34.9 323/21/2011 20.0 111.3 8.6 119.1 5.1 137.4 123.0 433/28/2011 93.2 85.6 93.0 94.0 404/4/2011 33.1 124.4 11.9 240.2 10.7 329.1 207.3 664/18/2011 53.8 175.6 20.7 233.9 9.1 307.0 307.0 1194/22/2011 361.5 305.6 424.3 437.4 1595/4/2011 37.8 148.5 5.6 174.7 5.0 180.5 228.4 9610/11/2011 1.2 16.9 5.1 27.3 7.3 40.7 513/12/2012 3.1 33.1 2.0 42.7 4.8 253/26/2012 10.1 61.2 11.1 72.5 3.3 88.4 854/10/2012 19.9 31.4 6.7 49.9 51.5 5.2 70.9 14410/18/2012 1.3 7.6 2.2 14.4 3.4 11.5 11.1 28

Notes:Load = calculated using the measured or surrogate concentration or half the detection limit for the day identified and the calculated or measured flow for the identified date. Spring = March and AprilFall = September through December

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

SUMMARY See Appendix C for Summary by stationSPRING2005 56.6 55.4 45.32006 242.5 283.3 245.82007 91.0 109.4 94.92008 208.0 238.9 190.82009 102.1 125.5 78.22010 69.4 73.9 76.22011 180.6 223.0 200.62012 55.0 79.6Average 125.6 148.6 133.1Min 55.0 55.4 45.3Max 242.5 283.3 245.82008 wo 4/22/08

144.4 167.2 125.7

Ave Yearly w/o 4/22/08 117.7 139.7 123.8

FALL2005 26.1 28.6 24.92006 31.6 37.7 35.72007 19.9 22.1 18.52008 18.5 18.4 13.52009 25.9 25.0 23.22010 22.8 26.1 26.02011 27.3 40.72012 14.4 11.5 11.1Average 23.3 26.3 21.9Min 14.4 11.5 11.1Max 31.6 40.7 35.7

SPRING Based on individual measurements from this tableMin 14.7 17.6 13.8Max 653.4 740.6 646.5FALL Based on individual measurements from this tableMin 14.4 11.5 11.1Max 36.7 47.4 39.3

Notes:Load = calculated using the measured or surrogate concentration or half the detection limit for the day identified and the calculated or measured flow for the identified date. Spring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at a sampling station (see Appendix C)

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

1/14/20053/3/20053/10/20053/17/20053/24/20053/31/20054/3-5/054/12/20055/23/20056/28/20057/29/20058/25/20059/12/20059/22/200510/18/200510/25/20051/31/20063/9/20063/16/20063/23/20063/30/20064/6/20064/12/20064/20/20064/26/20065/22/20069/27/200610/23/20061/29/20073/2/20073/13/20073/20/20073/27/20074/3/20074/10/20074/17/20074/24/20079/25/200710/16/20071/28/20083/4/20083/11/20083/18/20083/25/20084/8/20084/15/20084/22/20084/29/20085/28/2008

SAMPDAY EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

0.9 19.5 12.9 12.8 0.1 6.6 8.1 0.02 8.1 6.6 -1.5 4% 63% 63% 0.5% 33% 0.1% 40% 32% -7%43.743.7

20.7 30.9 27.3 29.7 -2.5 3.7 22.5 7.2 15.4 -3.5 -18.9 40% 53% 58% -5% 7% 14% 30% -7% -36%38.953.6

18.2 38.017.7 90.3 65.4 74.6 -9.2 24.8 42.3 14.5 27.8 10.4 -17.4 16% 61% 69% -8% 23% 13% 26% 10% -16%365.4 -151.4 -177.8 -157.8 -20.0 26.4 28.1 14.0 14.1 12.3 -1.8 171% -83% -74% -9% 12% 7% 7% 6% -1%

60.5 -19.0 -31%27.7 -2.3 -8%24.3 -3.8 -16%

2.5 24.2 19.9 16.3 3.6 4.3 2.2 6.1 -3.8 -1.8 2.1 9% 75% 61% 14% 16% 23% -14% -7% 8%16.0 -0.7 -4%

1.7 33.2 26.1 26.4 -0.3 7.1 5.5 1.5 4.0 5.6 1.6 5% 75% 75% -0.8% 20% 4% 12% 16% 5%26.8 -1.8 -7%

1.8 28.8 28.2 12.0 16.2 0.6 5.4 -4.8 6% 92% 39% 53% 2% 18% -16%280.4 -18.4 -7%145.7 45.8 31%

11.0 98.5 92.1 95.8 -3.6 6.4 8.2 8.7 -0.6 -2.4 -1.8 10% 84% 87% -3% 6% 8% -0.5% -2% -2%138.3 4.5 3%384.4 45.8 12%281.6 -6.8 -2%

57.0 259.3 166.9 172.5 -5.6 92.5 87.0 5.8 81.1 86.6 5.5 18% 53% 55% -2% 29% 2% 26% 27% 2%283.7 -22.1 -8%

40.9 74.6 32.3 38.7 -6.4 42.3 5.7 36.7 35% 28% 33% -6% 37% 5% 32%1.5 25.0 16.4 18.2 -1.8 8.6 1.4 7.2 5% 62% 69% -7% 32% 5% 27%1.7 35.0 32.1 38.5 -6.4 2.9 4.1 -1.2 5% 87% 105% -17% 8% 11% -3%1.2 29.9 14.2 10.6 3.5 15.7 6.7 9.0 4% 46% 34% 11% 51% 22% 29%

14.756.2 43.6 12.6 13.5 2.2 11.4 10.4 -1.0 78% 22% 4% 20% 19% -2%

19.6 90.9 62.2 59.3 2.8 28.7 -22.5 3.6 -26.1 25.1 51.2 18% 56% 54% 3% 26% 3% -24% 23% 46%116.2 66.1 50.1 21.9 5.8 16.2 44.3 28.2 57% 43% 5% 14% 38% 24%89.8 53.3 36.4 16.2 4.6 11.7 31.9 20.2 59% 41% 5% 13% 35% 22%

118.4 82.8 35.6 25.2 0.3 24.9 35.3 10.4 70% 30% 0.3% 21% 30% 9%23.1 87.0 61.1 57.4 3.7 25.9 24.8 4.5 20.4 21.5 1.1 21% 55% 52% 3% 24% 4% 19% 20% 1.0%

112.0 105.9 6.1 19.4 6.0 13.4 0.1 -13.3 95% 5% 5% 12% 0% -12%1.7 20.0 25.2 15.5 9.8 -5.2 3.0 -8.2 8% 116% 71% 45% -24% 14% -38%2.1 16.0 13.1 13.5 -0.4 2.9 2.9 0.0 11% 73% 75% -2% 16% 16% 0.0%

13.2 13.0 6.4 6.6 0.2 1.3 -1.1 99% 49% 50% 1% 10% -8%37.030.428.8

3.2 39.5 43.5 54.9 -11.4 -4.0 2.4 -6.4 8% 102% 128% -26.7% -9.3% 5.7% -15%134.3337.7

125.2 528.2 528.6 536.3 -7.7 -0.4 3.4 -3.8 19% 81% 82% -1% 0% 1% -1%399.7

26.9 146.6 79.6 62.0 17.6 67.0 61.6 13.0 48.6 54.0 5.4 15% 46% 36% 10% 39% 7% 28% 31% 3%

UpstreamBelden Segment

Percent of E-12A Load

Rock Crk GW

Upstream Segment 2

Segment 5aLower SegmentBelden Segment

Above Fall Crk

Below Fall Creek

AllEntire Entire

RockCreekRex FlatsGroundwater

Lower Segment

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

SAMPDAY

6/24/20087/29/20088/27/20089/18/20089/29/200810/20/200810/22/20081/8/20092/19/20093/11/20093/20/20093/25/20094/8/20094/20/20099/23/20093/6/20103/17/20104/2/20104/15/20109/24/20103/7/20113/21/20113/28/20114/4/20114/18/20114/22/20115/4/201110/11/20113/12/20123/26/20124/10/201210/18/2012

EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

UpstreamBelden Segment

Percent of E-12A Load

Rock Crk GW

Upstream Segment 2

Segment 5aLower SegmentBelden Segment

Above Fall Crk

Below Fall Creek

AllEntire Entire

RockCreekRex FlatsGroundwater

Lower Segment

23.5 67.9 49.6 32.4 17.3 18.3 5.7 7.3 -1.6 11.0 12.6 26% 54% 35% 19% 20% 8% -2% 12% 14%5.9 24.4 13.0 9.0 4.0 11.5 6.2 4.4 1.7 7.0 5.3 19% 43% 30% 13% 38% 15% 6% 23% 18%1.8 21.9 12.5 11.0 1.5 9.4 7.9 1.3 6.6 8.1 1.6 8% 53% 46% 6% 40% 5% 28% 34% 7%1.0 17.7 10.0 5.5 4.5 7.7 6.7 1.2 5.5 6.5 1.0 6% 53% 30% 24% 41% 6% 29% 35% 5%2.9 17.7 9.2 9.1 0.1 8.5 0.4 8.1 14% 45% 44% 0.6% 41% 2% 39%0.7 15.7 10.6 8.8 1.8 5.1 0.3 4.8 4% 65% 54% 11% 31% 2% 29%1.0 17.2 9.4 4.2 5.2 7.8 5.8 1.1 4.7 6.6 2.0 5% 52% 23% 29% 43% 6% 26% 37% 11%1.1 16.2 10.3 5.9 6% 60% 34%1.1 24.9 17.5 7.3 1.0 6.4 4% 68% 28% 4% 24%4.3 52.0 37.8 14.3 2.3 11.9 8% 67% 25% 4% 21%15.7 59.0 52.6 6.4 2.0 4.4 21% 70% 9% 3% 6%20.9 72.8 70.8 2.0 3.7 -1.7 22% 76% 2% 4% -2%32.7 93.2 65.7 27.5 4.4 23.1 26% 52% 22% 3% 18%38.7 121.0 110.7 10.3 3.7 6.6 24% 69% 6% 2% 4%1.9 24.0 15.3 8.6 1.1 7.5 7% 59% 33% 4% 29%

19.2 17.7 1.5 3.2 -1.7 92% 8% 17% -9%30.2 53.9 -23.8 5.3 -29.1 179% -79% 18% -96%41.5 23.3 18.2 7.0 11.3 56% 44% 17% 27%

25.4 161.2 99.6 61.6 48.8 12.9 14% 53% 33% 26% 7%2.0 20.8 14.2 6.7 0.6 6.1 9% 62% 29% 2% 27%

35.6 28.9 6.7 8.2 -1.5 81% 19% 23% -4%20.0 99.1 91.3 7.8 8.6 -0.8 17% 77% 7% 7% -0.7%

93.233.1 207.1 91.3 115.8 11.9 103.9 14% 38% 48% 5% 43%53.8 180.1 121.8 58.3 20.7 37.6 23% 52% 25% 9% 16%

361.537.8 136.9 110.7 26.2 5.6 20.6 22% 63% 15% 3% 12%1.2 26.1 15.7 10.5 5.1 5.4 4% 57% 38% 19% 20%3.1 39.6 30.0 9.6 2.0 7.6 7% 70% 22% 5% 18%10.1 62.4 51.1 11.3 11.1 0.2 14% 70% 16% 15% 0.3%19.9 30.0 11.5 18.5 6.7 11.8 40% 23% 37% 13% 24%1.3 13.1 6.3 6.8 2.2 4.6 9% 43% 47% 15% 32%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present,with the exception of E-3. If E-3 was not sampled the Loading presented from E-3 to a designated station is the load from that designated station.

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

SAMPDAY

SUMMARYSPRING20052006200720082009201020112012AverageMinMax2008 wo 4/22/08Ave Yearly w/o 4/22/08

FALL20052006200720082009201020112012AverageMinMax

SPRINGMinMaxFALLMinMax

EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

UpstreamBelden Segment

Percent of E-12A Load

Rock Crk GW

Upstream Segment 2

Segment 5aLower SegmentBelden Segment

Above Fall Crk

Below Fall Creek

AllEntire Entire

RockCreekRex FlatsGroundwater

Lower Segment

18.9 50.2 46.3 47.4 -5.8 14.3 32.4 10.8 21.6 3.5 -18.2 28% 57% 63% -7% 15% 14% 28% 1.4% -26%34.0 234.0 129.5 134.1 -4.6 49.4 47.6 7.3 40.3 42.1 6.6 14% 68% 71% -3% 18% 4.9% 12.6% 13% 4%21.3 85.6 67.8 58.3 3.3 27.9 14.1 3.8 10.3 24.1 13.8 19% 67% 53% 3% 27% 3.8% 11% 23% 13%64.2 192.0 286.0 295.6 -9.6 -2.2 2.9 -5.1 13% 91% 105% -14% -5% 3.1% -8%22.5 79.6 67.5 12.1 3.2 8.9 20% 67% 13% 3.3% 10%25.4 63.0 48.6 14.4 16.1 -1.7 14% 95% 2% 19% -18%35.6 162.8 83.3 47.1 12.4 34.8 18% 62% 25% 11% 14%11.0 44.0 30.9 13.1 6.6 6.5 20% 55% 25% 11% 14%29.1 113.9 95.0 133.9 -4.2 22.0 31.4 7.9 24.1 14.1 0.7 18% 70% 73% -5% 15% 8.8% 17% 6% -3.3%11.0 44.0 30.9 47.4 -9.6 -2.2 14.1 2.9 10.3 -5.1 -18.2 13% 55% 53% -14% -5% 3.1% 10.7% -18% -26%64.2 234.0 286.0 295.6 3.3 49.4 47.6 16.1 40.3 42.1 13.8 28% 95% 105% 3% 27% 19% 28% 23% 13%

3.2 143.9 43.5 54.9 -11.4 -4.0 2.4 -6.4 8% 102% 128% -27% -9% 6% -15%

21.5 107.9 64.7 73.7 -4.6 21.8 31.4 7.8 24.1 14.0 0.7 18% 72% 79% -8% 14% 9% 17% 5% -3.3%

2.1 25.0 23.0 21.3 1.7 5.7 3.9 3.8 0.1 1.9 0.3 7% 75% 68% 6% 18% 13% -1% 5% 0%1.6 30.0 24.3 28.3 -4.1 5.7 2.7 3.0 5% 75% 87% -12% 20% 8% 12%1.9 18.0 19.2 14.5 4.7 -1.2 3.0 -4.1 10% 94% 73% 21% -4% 15% -19%1.4 17.1 9.8 6.9 2.9 7.3 6.2 0.7 5.1 6.5 1.5 7% 54% 38% 16% 39% 4% 27% 35% 8%1.9 24.0 15.3 8.6 1.1 7.5 7% 59% 33% 4% 29%2.0 20.8 14.2 6.7 0.6 6.1 9% 62% 29% 2% 27%1.2 26.1 15.7 10.5 5.1 5.4 4% 57% 38% 19% 20%1.3 13.1 6.3 6.8 2.2 4.6 9% 43% 47% 15% 32%1.7 21.8 16.0 17.8 1.3 6.3 5.0 2.4 2.6 3.9 0.9 7% 65% 66% 8% 28% 10% 13% 18% 4%1.2 13.1 6.3 6.9 -4.1 -1.2 3.9 0.6 0.1 -4.1 0.3 4% 43% 38% -12% -4% 2% -1% -19% 0%2.1 30.0 24.3 28.3 4.7 10.5 6.2 5.1 5.1 7.5 1.5 10% 94% 87% 21% 47% 19% 27% 35% 8%

Based on individual measurements from this table3.1 14.7 11.5 29.7 -11.4 -23.8 -22.5 0.3 -26.1 -29.1 -22.1 7% 23% 52% -27% -79% 0% -24% -96% -36%

125.2 528.2 528.6 536.3 3.7 115.8 87.0 48.8 81.1 103.9 51.2 40% 179% 128% 3% 48% 26% 30% 43% 46%Based on individual measurements from this table

0.7 13.1 6.3 4.2 -6.4 -5.2 2.2 0.3 -3.8 -8.2 -1.8 4% 43% 23% -17% -24% 2% -14% -38% -7%2.9 35.0 32.1 38.5 9.8 10.5 6.7 6.1 5.5 8.1 2.1 14% 116% 105% 45% 47% 23% 29% 39% 11%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present,with the exception of E-3. If E-3 was not sampled the Loading presented from E-3 to a designated station is the load from that designated station.

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

1/14/20053/3/20053/10/20053/17/20053/24/20053/31/20054/3-5/054/12/20055/23/20056/28/20057/29/20058/25/20059/12/20059/22/200510/18/200510/25/20051/31/20063/9/20063/16/20063/23/20063/30/20064/6/20064/12/20064/20/20064/26/20065/22/20069/27/200610/23/20061/29/20073/2/20073/13/20073/20/20073/27/20074/3/20074/10/20074/17/20074/24/20079/25/200710/16/20071/28/20083/4/20083/11/20083/18/20083/25/20084/8/20084/15/20084/22/20084/29/20085/28/2008

SAMPDAY

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

0.9 -0.9 -1.6 0.7 1.8 3.3 -2.4 96% 4% 16% -11% 6.4 77% 23%-6.9 2.4 -9.4 119% -19% 7% -25% -9.7 136% -36%0.6 2.7 -2.1 99% 1% 6% -4.7% -4.4 111% -11%-7.1 -7.5 -11.0 3.5 0.4 2.9 -9.9 116% -16% 6% -22% -8.5 124% -24%3.3 2.5 0.7 92% 8% 6% 2% -6.7 119% -19%-0.4 3.2 -3.6 101% -1% 6% -6.7% -11.6 128% -28%

-8.3 116% -16%-0.8 -12.6 -17.3 4.6 11.9 11.7 -12.4 101% -1% 11% -12% -22.1 126% -26%

-13.3 -14.6 -38.9 24.3 1.3 17.6 -30.9 107% -7% 9% -15% 0.0 100% 0.0%-2.5 1.6 -4.1 6.8-2.9 -2.7 -0.2 1.8-5.3 -5.3 0.0 1.4

-6.7 -2.6 -3.6 1.0 -4.2 1.4 -8.1 134% -34% 7% -41% -3.5 121% -21%-1.8 -1.9 0.1 1.5

2.2 1.1 -2.6 3.7 1.1 2.4 -0.2 94% 6% 7% -0.6% -3.8 111% -11%-1.1 -3.5 2.4 2.3

-0.6 -2.2 1.7 2.3 -2.9 102% -2% 8% -10% -4.6 118% -18%20.5 -52.7 -60.5 7.8 73.2 8.4 12.1 93% 7% 3% 4% 4.9 98% 2%-24.0 -43.5 -51.3 7.8 19.5 8.3 -32.4 120% -20% 7% -27% 0.0 100% 0.0%3.7 -4.6 -2.1 -2.5 8.4 8.3 -4.6 97% 3% 7% -4% -21.4 123% -23%8.7 -17.6 -18.1 0.5 26.3 10.4 -1.7 94% 6% 7% -1.1% -26.7 122% -22%

15.1 -44.6 -79.3 34.7 59.7 17.0 -2.0 96% 4% 4% -0.5% -79.9 125% -25%145.8 56.9 32.2 24.7 88.9 6.2 139.6 66% 34% 1% 33% -80.1 123% -23%156.9 -63.1 35.2 -98.2 220.0 4.5 152.5 67% 33% 1% 32% -59.2 114% -14%

20.2 16.7 3.5 4.710.2 81.8 -71.6 6.2 4.0 92% 8% 5% 3% -6.6 106% -6%1.7 2.0 -0.3 2.3 -0.6 94% 6% 8% -2% 4.1 87% 13%

10.6 9.1 1.5 5.6 5.0 78% 22% 12% 11% -8.1 121% -21%-1.2 -4.7 3.6 3.0 -4.2 104% -4% 10% -14% -6.2 126% -26%2.9 2.1 0.8 84% 16% 12% 5% -3.7 127% -27%2.5 6.5 -4.0 96% 4% 11% -7% -12.7 128% -28%

10.2 9.2 1.0 4.9 5.4 92% 8% 4% 4% -21.2 121% -21%20.7 4.2 16.6 85% 15% 3% 12% -19.9 117% -17%18.2 5.5 12.7 83% 17% 5% 12% -11.7 112% -12%33.9 5.9 28.0 78% 22% 4% 18% -20.9 116% -16%28.4 9.0 19.4 4.6 23.7 80% 20% 3% 17% -17.3 114% -14%30.8 5.5 25.3 78% 22% 4% 18% -8.9 107% -7%0.6 1.4 -0.8 2.9 -2.3 97% 3% 13% -10% -3.3 117% -17%3.8 4.3 -0.5 2.2 1.6 83% 17% 10% 7% -3.8 121% -21%3.0 0.0 3.0 2.0 1.0 82% 18% 12% 6% -3.5 128% -28%-7.8 2.2 -9.9 127% -27% 7% -34% -6.5 128% -28%-4.5 2.3 -6.8 117% -17.3% 8.8% -26% -5.8 129% -29%3.6 2.5 1.1 89% 11% 8% 3% -6.0 123% -23%-0.9 -2.2 1.2 2.3 -3.3 102% -2.3% 5.6% -8% -9.3 129% -29%14.1 4.0 10.0 91% 9% 3% 7% -38.1 135% -35%47.8 7.6 40.2 88% 12.4% 2.0% 10% -129.0 150% -50%87.2 38.9 48.3 8.3 78.8 88% 12% 1% 11% -94.1 115% -15%

107.3 18.4 88.9 79% 21.2% 3.6% 18% -95.7 123% -23%29.8 19.7 11.2 18.6 85% 15% 6% 9%

Segment 5b Segment 5cPercent of E-15 Load Percent of E-22 Load

Upstream Cross CreekNon Cross Creek Load

Non-Cross Creek

AllUpstream In Segment

AllCross CreekSegmentWTP and CTP WTP CTP

Below Cross Creek

(Minturn)

Loading by Sampling Station subsegments

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

SAMPDAY

6/24/20087/29/20088/27/20089/18/20089/29/200810/20/200810/22/20081/8/20092/19/20093/11/20093/20/20093/25/20094/8/20094/20/20099/23/20093/6/20103/17/20104/2/20104/15/20109/24/20103/7/20113/21/20113/28/20114/4/20114/18/20114/22/20115/4/201110/11/20113/12/20123/26/20124/10/201210/18/2012

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

Segment 5b Segment 5cPercent of E-15 Load Percent of E-22 Load

Upstream Cross CreekNon Cross Creek Load

Non-Cross Creek

AllUpstream In Segment

AllCross CreekSegmentWTP and CTP WTP CTP

Below Cross Creek

(Minturn)

Loading by Sampling Station subsegments

2.9 -9.1 9.2 -6.2 97% 3% 10% -7%3.9 -1.4 4.2 -0.4 89% 11% 12% -1.1%-1.0 -5.1 2.6 -3.6 104% -4% 11% -16%-2.2 -2.9 3.4 -5.6 113% -13% 21% -34%-1.2 1.2 -2.4 5.2 -6.4 106% -6% 27% -33% -7.9 169% -69%1.2 -1.3 2.4 5.9 -4.7 93% 7% 34% -27% -2.1 114% -14%2.0 -0.7 4.0 -1.9 90% 10% 20% -10%

2.6 91% 9% -8.3 141% -41%-2.4 3.8 -6.2 104% -4% 7% -11% -22.4 171% -71%

15.7 4.6 11.1 86% 14% 4% 10% -6.9 107% -7%15.6 5.6 10.0 89% 11% 4% 7% -38.4 137% -37%37.7 5.7 32.0 81% 19% 3% 16% -93.5 190% -90%-0.9 2.2 -3.1 104% -4% 9% -12% -1.8 108% -8%-0.7 104% -4% -0.1 101% -0.6%-2.4 108% -8% 1.6 95% 5%3.6 92% 8% 6.7 87% 13%

17.6 28.5 -10.9 91% 9% 14% -5% 1.1 99% 0.5%3.3 7.8 -4.5 87% 13% 30% -17% -0.1 100% -0.4%

11.8 8.5 3.2 2.5 9.3 75% 25% 5% 20% -12.5 136% -36%18.3 5.1 13.2 87% 13% 4% 10% -14.4 112% -12%-0.3 -7.7 100% -0.3% 1.0 99% 1%88.9 10.7 78.2 73% 27% 3% 24% -121.8 159% -59%73.1 9.1 64.0 76% 24% 3% 21% 0.0 100% 0.0%62.9 -55.9 85% 15% 13.0 97% 3.0%5.8 5.0 0.8 97% 3.2% 2.8% 0.4% 47.9 79% 21%

13.4 7.3 6.1 67% 33% 18% 15%4.8

15.9 3.3 12.6 82% 18% 4% 14%21.0 1.6 5.2 15.8 70% 30% 7% 22%-2.9 3.4 -6.3 125% -25% 29% -54% -0.5 104% -4%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present.

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Appendix D-1Zinc Loading (lbs/day) Analysis by Segment

SAMPDAY

SUMMARYSPRING20052006200720082009201020112012AverageMinMax2008 wo 4/22/08Ave Yearly w/o 4/22/08

FALL20052006200720082009201020112012AverageMinMax

SPRINGMinMaxFALLMinMax

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

Segment 5b Segment 5cPercent of E-15 Load Percent of E-22 Load

Upstream Cross CreekNon Cross Creek Load

Non-Cross Creek

AllUpstream In Segment

AllCross CreekSegmentWTP and CTP WTP CTP

Below Cross Creek

(Minturn)

Loading by Sampling Station subsegments

-1.9 -10.0 -14.1 4.1 6.1 4.2 -6.1 104% -4% 7% -11% -10.2 123% -23%46.7 -18.6 -15.9 -2.7 70.8 8.5 37.7 90% 9.6% 4% 5% -37.5 115% -15%18.5 9.1 10.2 4.9 13.6 84% 16% 6% 10% -14.6 118% -18%30.8 18.4 24.8 5.9 24.9 98% 2% 5% -2% -48.1 129% -29%16.6 4.9 11.7 90% 10% 5% 5% -40.3 151% -51%4.5 28.5 -10.9 99% 1% 14% -5% 2.3 95% 5%42.4 8.5 -31.8 3.2 6.8 41.2 83% 17% 4% 18% -22.5 117% -17%18.4 1.6 4.4 14.2 76% 24% 5% 18%22.0 1.5 -15.1 0.7 23.0 8.5 15.8 91% 9% 6% 5% -24.4 121% -21%-1.9 -18.6 -31.8 -2.7 3.2 4.2 -10.9 76% -4% 4% -11% -48.1 95% -51%46.7 18.4 1.6 4.1 70.8 28.5 41.2 104% 24% 14% 18% 2.3 151% 5%

22.8 -2.2 1.2 5.6 17.2 99% 1% 5% -4% -41.5 131% -31%

21.0 -2.6 -15.1 0.7 18.3 8.5 14.8 0.9 0.1 0.1 0.0 -23.5 121% -21%

-2.3 -1.1 -2.9 1.8 -1.6 1.9 -4.2 114% -14% 7% -21% -3.6 116% -16.2%6.2 5.5 0.6 3.9 2.2 86% 14% 10% 4% -2.0 104% -4%2.2 2.8 -0.6 2.6 -0.4 90% 10% 12% -1% -3.6 119% -19%0.0 0.0 -1.8 0.0 4.6 -4.7 101% -1% 25% -26% -5.0 141% -41%-0.9 2.2 -3.1 104% -4% 9% -12% -1.8 108% -8%3.3 7.8 -4.5 87% 13% 30% -17% -0.1 100% -0.4%13.4 7.3 6.1 67% 33% 18% 15%-2.9 3.4 -6.3 125% -25% 29% -54% -0.5 104% -4.2%2.4 1.8 -2.3 1.8 -0.4 4.2 -1.8 97% 3% 17% -14% -2.4 113% -13%-2.9 -1.1 -2.9 1.8 -1.6 1.9 -6.3 67% -25% 7% -54% -5.0 100% -41%13.4 5.5 -1.8 1.8 0.6 7.8 6.1 125% 33% 30% 15% -0.1 141% 0%

Based on individual measurements from this table-24.0 -63.1 -79.3 -98.2 0.4 2.1 -32.4 66% -27% 1% -34% -129.0 87% -90%156.9 56.9 35.2 34.7 220.0 28.5 152.5 127% 34% 14% 33% 13.0 190% 13%

Based on individual measurements from this table-6.7 -2.6 -3.6 0.1 -4.2 1.4 -8.1 67% -34% 7% -54% -8.1 87% -69%13.4 9.1 -0.7 3.7 2.4 7.8 6.1 134% 33% 34% 15% 4.1 169% 13%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present.

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APPENDIX D-2

CADMIUM LOADING (LBS/DAY) ANALYSIS BY SEGMENT

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

1/14/2005 0.007 0.020 0.022 0.005 0.034 0.031 0.033 0.028 0.004 0.028 0.042 293/3/2005 0.063 0.001 0.041 0.039 273/10/2005 0.066 0.001 0.067 0.058 303/17/2005 0.036 0.101 0.098 0.015 0.133 0.086 0.069 0.065 0.001 0.064 0.053 293/24/2005 0.063 0.001 0.064 0.055 303/31/2005 0.110 0.002 0.097 0.076 314/3-5/05 0.110 0.178 0.234 0.177 0.083 0.111 414/12/2005 0.078 0.192 0.214 0.030 0.297 0.238 0.192 0.174 0.003 0.218 0.183 405/23/2005 0.923 0.979 1.042 0.024 1.057 1.029 0.834 0.807 0.092 0.358 0.860 7626/28/2005 0.811 0.797 0.797 0.906 0.683 2957/29/2005 0.234 0.227 0.227 0.258 0.184 848/25/2005 0.128 0.122 0.122 0.138 0.059 459/12/2005 0.008 0.033 0.051 0.016 0.047 0.048 0.041 0.038 0.004 0.012 0.042 339/22/2005 0.114 0.108 0.108 0.122 0.057 4010/18/2005 0.012 0.059 0.068 0.003 0.072 0.051 0.054 0.066 0.008 0.085 0.056 5010/25/2005 0.166 0.159 0.159 0.181 0.089 591/31/2006 0.009 0.025 0.060 0.012 0.050 0.036 0.002 0.046 0.046 273/9/2006 0.896 0.765 0.701 0.687 0.004 0.789 0.839 593/16/2006 0.390 0.004 0.326 0.326 383/23/2006 0.039 0.356 0.373 0.019 0.378 0.295 0.337 0.286 0.004 0.300 0.248 393/30/2006 0.431 0.004 0.401 0.327 424/6/2006 1.254 1.098 1.098 1.110 0.015 1.198 0.979 1134/12/2006 1494/20/2006 0.270 0.842 1.002 0.013 0.598 1.160 1.289 0.800 0.010 1.479 1.735 2174/26/2006 3095/22/2006 0.170 0.340 0.266 0.012 1.954 0.281 1.925 0.614 0.086 0.331 0.331 7139/27/2006 0.015 0.049 0.052 0.002 0.035 0.092 0.012 0.064 0.082 6910/23/2006 0.029 0.087 0.124 0.007 0.081 0.088 0.017 0.139 0.087 681/29/2007 0.007 0.023 0.026 0.012 0.042 0.027 0.001 0.027 0.022 303/2/2007 0.019 0.001 0.018 0.015 203/13/2007 0.091 0.092 0.104 0.003 0.121 0.094 323/20/2007 0.064 0.199 0.208 0.006 0.185 0.223 0.222 0.004 0.237 0.173 663/27/2007 0.207 0.210 0.276 0.005 0.331 0.249 754/3/2007 0.191 0.193 0.195 0.005 0.227 0.208 694/10/2007 0.296 0.300 0.324 0.006 0.398 0.344 1084/17/2007 0.081 0.249 0.266 0.009 0.012 0.318 0.321 0.006 0.385 0.318 1094/24/2007 0.441 0.448 0.332 0.010 0.342 0.332 1629/25/2007 0.013 0.019 0.039 0.006 0.014 0.017 0.008 0.023 0.023 5310/16/2007 0.012 0.013 0.014 0.005 0.013 0.016 0.005 0.021 0.021 491/28/2008 0.006 0.014 0.001 0.006 0.007 0.001 0.008 0.008 243/4/2008 2.930 0.006 0.055 0.049 253/11/2008 0.066 0.003 0.044 0.042 233/18/2008 0.055 0.004 0.054 0.036 233/25/2008 0.023 0.129 0.120 0.004 0.096 0.073 0.002 0.087 0.065 284/8/2008 0.410 0.002 0.443 0.306 314/15/2008 1.007 0.003 1.121 0.686 594/22/2008 0.376 2.772 2.698 0.007 2.457 2.514 0.008 2.700 2.274 1214/29/2008 1.332 0.009 1.821 1.391 1695/28/2008 1.745 0.407 0.513 0.038 0.680 0.710 0.788 0.718 0.881 730

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

6/24/2008 2.022 0.344 0.297 0.023 0.301 0.365 0.356 0.918 0.401 8467/29/2008 0.638 0.077 0.078 0.011 0.110 0.092 0.085 0.348 0.117 2678/27/2008 0.172 0.039 0.052 0.003 0.056 0.058 0.051 0.081 0.068 729/18/2008 0.105 0.030 0.037 0.002 0.042 0.040 0.040 0.041 0.039 449/29/2008 0.009 0.024 0.010 0.001 0.032 0.011 0.004 0.014 0.014 3710/20/2008 0.027 0.025 0.027 0.000 0.021 0.028 0.003 0.041 0.024 3210/22/2008 0.081 0.021 0.027 0.002 0.035 0.031 0.029 0.003 0.034 341/8/2009 0.089 0.083 0.024 322/19/2009 0.027 0.033 0.001 0.031 0.039 0.031 233/11/2009 0.080 0.111 0.004 0.104 0.011 0.098 0.070 253/20/2009 0.076 0.216 0.005 0.204 0.095 403/25/2009 0.056 0.262 0.007 0.207 0.020 0.291 0.229 474/8/2009 0.064 0.174 0.006 0.279 0.019 0.195 0.223 544/20/2009 0.270 0.535 0.009 0.678 0.030 0.967 0.238 919/23/2009 0.056 0.066 0.002 0.063 0.011 0.095 0.038 473/6/2010 0.044 0.006 0.032 0.022 0.033 183/17/2010 0.146 0.010 0.046 0.025 0.031 234/2/2010 0.055 0.017 0.084 0.069 0.069 314/15/2010 0.071 0.276 0.116 0.432 0.079 0.579 0.546 1239/24/2010 0.010 0.037 0.001 0.042 0.027 0.127 0.032 413/7/2011 0.076 0.022 0.078 0.115 0.003 0.075 0.024 323/21/2011 0.082 0.337 0.019 0.302 0.010 0.316 0.275 433/28/2011 0.231 0.298 0.205 0.221 404/4/2011 0.104 0.354 0.026 0.677 0.005 0.838 0.503 664/18/2011 0.125 0.507 0.049 0.643 0.021 0.823 0.844 1194/22/2011 1.090 1.176 1.186 1.286 1595/4/2011 2.522 0.579 0.014 0.778 0.005 0.621 0.756 9610/11/2011 0.012 0.045 0.010 0.069 0.016 0.088 513/12/2012 0.006 0.071 0.003 0.082 0.004 253/26/2012 0.020 0.164 0.021 0.202 0.004 0.199 854/10/2012 0.034 0.079 0.015 0.109 0.039 0.010 0.064 14410/18/2012 0.007 0.022 0.004 0.027 0.003 0.030 0.035 28

Notes:Load = calculated using the measured or surrogate concentration or half the detection limit for the day identified and the calculated or measured flow for the identified date. Spring = March and AprilFall = September through DecemberOnly zinc was analyzed for on 4/12/06 pr 4/26/06, not this metal

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

SUMMARY See Appendix C for Summary by stationSPRING2005 0.104 0.090 0.0822006 0.690 0.749 0.7422007 0.224 0.258 0.2172008 1.044 0.791 0.6062009 0.295 0.388 0.1712010 0.148 0.174 0.1702011 0.503 0.574 0.5252012 0.131 0.132Average 0.392 0.394 0.359Min 0.104 0.090 0.082Max 1.044 0.791 0.7422008 wo 4/22/08

0.842 0.518 0.368

Ave Yearly w/o 4/22/08 0.367 0.360 0.325

FALL2005 0.092 0.049 0.0492006 0.058 0.102 0.0842007 0.014 0.022 0.0222008 0.031 0.032 0.0192009 0.063 0.095 0.0382010 0.042 0.127 0.0322011 0.069 0.0882012 0.027 0.030 0.035Average 0.050 0.068 0.040Min 0.014 0.022 0.019Max 0.092 0.127 0.084

SPRING Based on individual measurements from this tableMin 0.019 0.018 0.015Max 2.930 2.700 2.274FALL Based on individual measurements from this tableMin 0.013 0.012 0.014Max 0.159 0.139 0.087

Notes:Load = calculated using the measured or surrogate concentration or half the detection limit for the day identified and the calculated or measured flow for the identified date. Spring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at a sampling station (see Appendix C)

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

1/14/20053/3/20053/10/20053/17/20053/24/20053/31/20054/3-5/054/12/20055/23/20056/28/20057/29/20058/25/20059/12/20059/22/200510/18/200510/25/20051/31/20063/9/20063/16/20063/23/20063/30/20064/6/20064/12/20064/20/20064/26/20065/22/20069/27/200610/23/20061/29/20073/2/20073/13/20073/20/20073/27/20074/3/20074/10/20074/17/20074/24/20079/25/200710/16/20071/28/20083/4/20083/11/20083/18/20083/25/20084/8/20084/15/20084/22/20084/29/20085/28/2008

SAMPDAY EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

0.007 0.024 0.015 0.014 0.001 0.010 0.012 0.005 0.007 0.004 -0.002 22% 47% 43% 3.4% 31% 17.2% 21% 14% -7%0.0630.066

0.036 0.050 0.062 0.065 -0.003 -0.012 0.035 0.015 0.020 -0.026 -0.047 42% 72% 75% -4% -13% 17% 24% -30% -54%0.0630.110

0.110 0.0690.078 0.159 0.135 0.114 0.021 0.024 0.083 0.030 0.053 -0.006 -0.059 33% 57% 48% 9% 10% 13% 22% -3% -25%0.923 0.106 0.120 0.057 0.063 -0.014 0.015 0.024 -0.009 -0.038 -0.029 90% 12% 6% 6% -1% 2% -0.9% -4% -3%

0.797 -0.015 -2%0.227 -0.008 -3%0.122 -0.006 -5%

0.008 0.040 0.043 0.025 0.018 -0.002 -0.003 0.016 -0.019 -0.019 0.001 16% 89% 52% 37% -5% 34% -40% -39% 1.4%0.108 -0.006 -6%

0.012 0.039 0.055 0.047 0.009 -0.016 0.004 0.003 0.001 -0.019 -0.021 24% 109% 91% 17.5% -32% 6% 3% -38% -41%0.159 -0.007 -4%

0.009 0.040 0.050 0.015 0.035 -0.010 0.012 -0.023 19% 102% 31% 71% -21% 25% -46%0.765 -0.132 -17%0.390

0.039 0.256 0.334 0.317 0.017 -0.078 0.005 0.019 -0.013 -0.097 -0.084 13% 113% 107% 6% -26% 6% -4.6% -33% -28%0.4311.098 -0.156 -14%

0.270 0.890 0.732 0.572 0.160 0.158 -0.404 0.013 -0.417 0.145 0.562 23% 63% 49% 14% 14% 1% -36% 13% 48%

0.170 0.111 0.095 0.170 -0.074 0.015 1.688 0.012 1.676 0.003 -1.673 61% 34% 60% -26% 5% 4% 596% 1.1% -595%0.015 0.020 0.037 0.034 0.003 -0.017 0.002 -0.020 44% 105% 96% 8% -49% 7% -56%0.029 0.052 0.095 0.058 0.037 -0.043 0.007 -0.050 36% 118% 72% 46% -53% 8% -62%0.007 0.035 0.019 0.016 0.003 0.016 0.012 0.004 17% 45% 38% 8% 38% 29% 9%

0.0190.104 0.091 0.013 0.001 0.012 87% 13% 12%

0.064 0.159 0.144 0.135 0.009 0.015 -0.023 0.006 -0.029 0.009 0.038 29% 64% 61% 4% 7% 3% -13% 4% 17%0.276 0.207 0.069 0.003 0.066 75% 25% 24%0.195 0.191 0.004 0.003 0.002 98% 2% 0.8%0.324 0.296 0.029 0.004 0.024 91% 9% 8%

0.081 0.237 0.185 0.169 0.017 0.052 -0.254 0.009 -0.263 0.042 0.306 25% 58% 53% 5% 16% 3% -83% 13% 96.2%0.332 0.441 -0.109 0.006 -0.115 133% -33% -35%

0.013 0.001 0.026 0.006 0.020 -0.025 0.006 -0.032 93% 183% 41% 142% -176% 44% -220%0.012 0.001 0.002 0.000 0.002 -0.001 0.005 -0.007 94% 16% 2% 14% -9% 41% -50.3%

0.006 0.014 0.006 0.009 -0.008 0.001 -0.009 222% 86% 137% -122% 22% -145%2.9300.0660.055

0.023 0.074 0.097 0.107 -0.010 -0.024 0.004 -0.028 23% 101% 111% -10.1% -24.5% 4.1% -29%0.4101.007

0.376 2.081 2.321 2.396 -0.074 -0.241 0.007 -0.248 15% 94% 98% -3% -10% 0% -10%1.332

1.745 -1.036 -1.233 -1.338 0.105 0.197 0.167 0.038 0.129 0.159 0.030 246% -174% -189% 15% 28% 5% 18% 22% 4%

Groundwater Rock Crk GWRex Flats

UpstreamBelden SegmentAll

Belden Segment Lower Segment Percent of E-12A Load

EntireAbove

Fall Crk

Upstream Segment 2

Segment 5a

Lower SegmentBelow Fall Creek

EntireRockCreek

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

SAMPDAY

6/24/20087/29/20088/27/20089/18/20089/29/200810/20/200810/22/20081/8/20092/19/20093/11/20093/20/20093/25/20094/8/20094/20/20099/23/20093/6/20103/17/20104/2/20104/15/20109/24/20103/7/20113/21/20113/28/20114/4/20114/18/20114/22/20115/4/201110/11/20113/12/20123/26/20124/10/201210/18/2012

EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

Groundwater Rock Crk GWRex Flats

UpstreamBelden SegmentAll

Belden Segment Lower Segment Percent of E-12A Load

EntireAbove

Fall Crk

Upstream Segment 2

Segment 5a

Lower SegmentBelow Fall Creek

EntireRockCreek

2.022 -1.657 -1.726 -1.679 -0.047 0.069 0.004 0.023 -0.019 0.045 0.064 553% -472% -459% -13% 19% 6% -5% 12% 18%0.638 -0.546 -0.560 -0.561 0.001 0.014 0.032 0.011 0.021 0.004 -0.018 692% -607% -608% 1% 15% 11% 23% 4% -19%0.172 -0.114 -0.120 -0.133 0.013 0.007 0.005 0.003 0.001 0.003 0.002 295% -206% -228% 22% 11% 6% 3% 6% 3%0.105 -0.065 -0.068 -0.075 0.007 0.003 0.006 0.002 0.003 0.001 -0.002 260% -168% -186% 18% 9% 6% 8% 3% -5%0.009 0.023 0.002 0.015 -0.013 0.022 0.001 0.021 27% 5% 46% -40.8% 68% 2% 66%0.027 -0.005 0.000 -0.001 0.001 -0.006 0.000 -0.006 126% 1% -6% 7% -27% 2% -29%0.081 -0.050 -0.054 -0.060 0.006 0.004 0.008 0.002 0.007 0.003 -0.004 260% -173% -192% 19% 14% 5% 21% 8% -13%

0.083 0.089 -0.006 107% -7%0.027 0.004 0.006 -0.002 0.001 -0.004 88% 19% -7% 5% -12%0.080 0.025 0.031 -0.006 0.004 -0.010 76% 30% -6% 3% -10%0.076 0.127 0.140 -0.013 0.005 -0.017 37% 69% -6% 2% -8%0.056 0.151 0.206 -0.055 0.007 -0.062 27% 99% -26% 4% -30%0.064 0.215 0.110 0.105 0.006 0.099 23% 39% 38% 2% 35%0.270 0.408 0.264 0.144 0.009 0.134 40% 39% 21% 1% 20%0.056 0.007 0.010 -0.002 0.002 -0.004 88% 15% -3% 3% -6%

0.032 0.044 -0.011 0.006 -0.017 136% -36% 18% -54%0.046 0.146 -0.101 0.010 -0.110 319% -219% 21% -240%0.084 0.055 0.029 0.017 0.012 65% 35% 21% 14%

0.071 0.361 0.205 0.156 0.116 0.041 16% 47% 36% 27% 9%0.010 0.032 0.027 0.005 0.001 0.004 23% 64% 12% 3% 10%

0.078 0.076 0.001 0.022 -0.020 98% 2% 28% -26%0.082 0.220 0.255 -0.035 0.019 -0.055 27% 85% -12% 6% -18.1%

0.2310.104 0.573 0.250 0.323 0.026 0.297 15% 37% 48% 4% 44%0.125 0.518 0.382 0.135 0.049 0.086 19% 59% 21% 8% 13%

1.0902.522 -1.745 -1.943 0.198 0.014 0.184 324% -250% 26% 2% 24%0.012 0.057 0.033 0.023 0.010 0.014 18% 48% 34% 14% 20%0.006 0.076 0.065 0.012 0.003 0.009 7% 78% 14% 4% 10%0.020 0.182 0.143 0.038 0.021 0.017 10% 71% 19% 11% 8.5%0.034 0.074 0.044 0.030 0.015 0.016 32% 41% 28% 13% 15%0.007 0.021 0.016 0.005 0.004 0.001 25% 58% 18% 13% 4%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present,with the exception of E-3. If E-3 was not sampled the Loading presented from E-3 to a designated station is the load from that designated station.

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

SAMPDAY

SUMMARYSPRING20052006200720082009201020112012AverageMinMax2008 wo 4/22/08Ave Yearly w/o 4/22/08

FALL20052006200720082009201020112012AverageMinMax

SPRINGMinMaxFALLMinMax

EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

Groundwater Rock Crk GWRex Flats

UpstreamBelden SegmentAll

Belden Segment Lower Segment Percent of E-12A Load

EntireAbove

Fall Crk

Upstream Segment 2

Segment 5a

Lower SegmentBelow Fall Creek

EntireRockCreek

0.075 0.085 0.099 0.083 0.009 0.006 0.059 0.022 0.037 -0.016 -0.053 37% 64% 62% 2.6% -1.6% 15% 23% -16.5% -39%0.154 0.638 0.533 0.444 0.089 0.040 -0.199 0.016 -0.215 0.024 0.048 18% 88% 78% 9.8% -6.4% 3.8% -20% -10% -2.8%0.072 0.206 0.222 0.152 0.013 0.011 -0.037 0.008 -0.146 0.026 0.048 27% 87% 57% 4.5% 5.6% 2.9% -48% 8.8% 17%0.199 0.994 1.209 1.251 -0.042 -0.132 0.005 -0.138 19% 98% 104% -6.5% -17% 2.2% -19%0.109 0.185 0.150 0.035 0.006 0.029 41% 55% 4% 2.6% 1.4%0.071 0.131 0.112 0.018 0.037 -0.019 16% 142% -46% 22% -68%0.104 0.452 0.241 0.106 0.029 0.077 21% 70% 15% 11% 3.3%0.020 0.111 0.084 0.027 0.013 0.014 16% 63% 20% 9.2% 11%0.101 0.350 0.331 0.483 0.017 0.014 -0.059 0.017 -0.108 0.000 0.014 25% 83% 75% 2.6% -3% 8.6% -15% -11% -8.3%0.020 0.085 0.084 0.083 -0.042 -0.132 -0.199 0.005 -0.215 -0.138 -0.053 16% 55% 57% -6.5% -46% 2.2% -47.9% -68% -39%0.199 0.994 1.209 1.251 0.089 0.106 0.059 0.037 0.037 0.077 0.048 41% 142% 104% 10% 20% 22% 23% 11% 17%

0.023 0.839 0.097 0.107 -0.010 -0.024 0.004 -0.028 23% 101% 111% -10% -25% 4.1% -29%

0.078 0.331 0.192 0.196 0.025 0.027 -0.059 0.017 -0.108 0.013 0.014 25% 84% 77% 2% -4.2% 8.8% -15% -12% -8.3%

0.010 0.087 0.049 0.036 0.013 -0.009 0.001 0.010 -0.009 -0.019 -0.008 20% 99% 72% 27% -19% 20% -19% -38% -12%0.022 0.036 0.066 0.046 0.020 -0.030 0.005 -0.035 40% 111% 84% 27% -51% 7.6% -59%0.013 0.001 0.014 0.003 0.011 -0.013 0.006 -0.019 94% 99% 21% 78% -93% 43% -135%0.055 -0.024 -0.030 -0.030 0.000 0.006 0.007 0.001 0.005 0.005 -0.003 168% -84% -85% 0.6% 16% 3.7% 15% 12% -8.9%0.056 0.007 0.010 -0.002 0.002 -0.004 88% 15% -3.4% 2.8% -6.3%0.010 0.032 0.027 0.005 0.001 0.004 23% 64% 12% 2.5% 10%0.012 0.057 0.033 0.023 0.010 0.014 18% 48% 34% 14% 20%0.007 0.021 0.016 0.005 0.004 0.001 25% 58% 18% 13% 4.4%0.023 0.027 0.023 0.014 0.011 -0.002 0.004 0.005 -0.002 -0.007 -0.006 59% 51% 23% 33% -11% 13% -2.1% -24% -11%0.007 -0.024 -0.030 -0.030 0.000 -0.030 0.001 0.001 -0.009 -0.035 -0.008 18% -84% -85% 0.6% -93% 2.5% -19% -135% -12%0.056 0.087 0.066 0.046 0.020 0.023 0.007 0.010 0.005 0.014 -0.003 168% 111% 84% 78% 34% 43% 15% 20% -8.9%

Based on individual measurements from this table0.006 0.019 0.031 0.065 -0.074 -0.241 -0.404 0.003 -0.417 -0.248 -0.156 7% 30% 48% -10% -219% 0.3% -83% -240% -54%0.376 2.930 2.321 2.396 0.160 0.323 0.083 0.116 0.053 0.297 0.562 76% 319% 111% 14% 48% 28% 24% 44% 96%

Based on individual measurements from this table0.007 -0.065 -0.068 -0.075 -0.013 -0.043 -0.003 0.000 -0.019 -0.050 -0.021 16% -173% -192% -41% -176% 1.8% -40% -220% -41%0.105 0.159 0.095 0.058 0.037 0.023 0.008 0.016 0.007 0.021 0.001 260% 183% 96% 142% 68% 44% 21% 66% 1.4%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present,with the exception of E-3. If E-3 was not sampled the Loading presented from E-3 to a designated station is the load from that designated station.

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

1/14/20053/3/20053/10/20053/17/20053/24/20053/31/20054/3-5/054/12/20055/23/20056/28/20057/29/20058/25/20059/12/20059/22/200510/18/200510/25/20051/31/20063/9/20063/16/20063/23/20063/30/20064/6/20064/12/20064/20/20064/26/20065/22/20069/27/200610/23/20061/29/20073/2/20073/13/20073/20/20073/27/20074/3/20074/10/20074/17/20074/24/20079/25/200710/16/20071/28/20083/4/20083/11/20083/18/20083/25/20084/8/20084/15/20084/22/20084/29/20085/28/2008

SAMPDAY

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

-0.004 -0.003 0.002 -0.005 -0.001 0.004 -0.008 113% -13% 14% -27% 0.0 65% 35%-0.022 0.001 -0.023 154% -54% 3% -57% 0.0 105% -5%0.000 0.001 -0.001 100% 0% 2% -1.7% 0.0 115% -15%-0.022 -0.021 -0.017 -0.003 -0.002 0.001 -0.024 135% -35% 2% -37% 0.0 120% -20%0.001 0.001 0.000 98% 2% 2% 0% 0.0 116% -16%-0.013 0.002 -0.015 114% -14% 2% -15.5% 0.0 127% -27%

0.0 75% 25%-0.020 -0.064 -0.045 -0.019 0.044 0.003 -0.023 109% -9% 1% -11% 0.0 119% -19%-0.670 -0.222 -0.195 -0.027 -0.449 0.092 -0.762 287% -187% 26% -213% 0.5 42% 58.3%

0.110 0.000 0.110 0.6830.031 0.000 0.031 0.1840.016 0.000 0.016 0.059

-0.036 -0.010 -0.007 -0.003 -0.026 0.004 -0.040 385% -285% 35% -320% 0.0 29% 71%0.014 0.000 0.014 0.057

0.034 0.015 0.003 0.012 0.018 0.008 0.026 60% 40% 9% 30.7% 0.0 150% -50%0.021 0.000 0.021 0.089

-0.003 -0.014 0.010 0.002 -0.005 107% -7% 4% -11% 0.0 100% 0%0.025 -0.078 -0.064 -0.014 0.103 0.004 0.020 97% 3% 1% 3% 0.0 94% 6%-0.063 0.004 -0.067 119% -19% 1% -21% 0.0 100% 0.0%0.005 -0.009 0.042 -0.051 0.014 0.004 0.001 98% 2% 1% 0% -0.1 121% -21%-0.030 0.004 -0.034 107% -7% 1% -8.5% -0.1 122% -22%0.100 0.011 0.000 0.011 0.089 0.015 0.085 92% 8% 1% 7.1% -0.2 122% -22%

0.319 -0.360 0.129 -0.489 0.679 0.010 0.309 78% 22% 1% 21% 0.3 85% 15%

0.050 0.333 1.644 -1.311 -0.283 0.086 -0.036 85% 15% 26% -11% 0.0 100% 0%0.029 0.057 -0.027 0.012 0.017 54% 46% 19% 27% 0.0 79% 21%0.058 0.007 0.051 0.017 0.040 58% 42% 13% 29% -0.1 160% -60%-0.015 -0.015 0.000 0.001 -0.016 155% -55% 4% -59% 0.0 123% -23%-0.001 0.001 -0.002 105% -5% 6% -10% 0.0 124% -24%0.017 0.003 0.014 86% 14% 2% 11% 0.0 129% -29%0.014 -0.001 0.016 0.004 0.010 94% 6% 2% 4% -0.1 138% -38%0.055 0.005 0.050 83% 17% 2% 15% -0.1 133% -33%0.032 0.005 0.027 86% 14% 2% 12% 0.0 109% -9%0.074 0.006 0.068 81% 19% 1% 17% -0.1 116% -16%0.068 0.003 0.064 0.006 0.061 82% 18% 2% 16% -0.1 121% -21%0.010 0.010 0.000 97% 3% 3% 0% 0.0 103% -3%0.009 0.003 0.006 0.008 0.001 62% 38% 34% 5% 0.0 100% 0%0.008 0.003 0.005 0.005 0.003 62% 38% 23% 15% 0.0 100% 0%0.002 0.001 0.001 0.001 0.000 78% 22% 17% 5% 0.0 100% 0%-2.875 0.006 -2.881 5364% -5264% 11% -5276% 0.0 112% -12%-0.022 0.003 -0.025 149% -49.1% 7.9% -57% 0.0 107% -7%-0.001 0.004 -0.005 103% -3% 8% -10% 0.0 150% -50%-0.009 -0.023 0.014 0.002 -0.011 111% -10.9% 2.1% -13% 0.0 134% -34%0.033 0.002 0.031 93% 7% 0% 7% -0.1 145% -45%0.114 0.003 0.111 90% 10.2% 0.3% 10% -0.4 163% -63%0.243 0.057 0.186 0.008 0.236 91% 9% 0% 9% -0.4 119% -19%0.488 0.009 0.479 73% 26.8% 0.5% 26% -0.4 131% -31%0.171 0.079 0.718 -0.547 81% 19% 82% -62%

In SegmentBelow Cross

Creek (Minturn)

Upstream Segment Cross CreekNon Cross Creek Load

UpstreamAll

Percent of E-22 LoadSegment 5c

All

Loading by Sampling Station subsegments

Cross CreekNon-Cross

Creek

Percent of E-15 LoadSegment 5b

WTP and CTP WTP CTP

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

SAMPDAY

6/24/20087/29/20088/27/20089/18/20089/29/200810/20/200810/22/20081/8/20092/19/20093/11/20093/20/20093/25/20094/8/20094/20/20099/23/20093/6/20103/17/20104/2/20104/15/20109/24/20103/7/20113/21/20113/28/20114/4/20114/18/20114/22/20115/4/201110/11/20113/12/20123/26/20124/10/201210/18/2012

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

In SegmentBelow Cross

Creek (Minturn)

Upstream Segment Cross CreekNon Cross Creek Load

UpstreamAll

Percent of E-22 LoadSegment 5c

All

Loading by Sampling Station subsegments

Cross CreekNon-Cross

Creek

Percent of E-15 LoadSegment 5b

WTP and CTP WTP CTP

0.035 -0.009 0.918 -0.883 91% 9% 229% -220%0.025 -0.007 0.348 -0.323 79% 21% 297% -276.2%0.009 -0.008 0.081 -0.072 86% 14% 120% -106%-0.002 0.000 0.041 -0.042 104% -4% 104% -108%-0.018 -0.021 0.003 0.004 -0.022 224% -124% 28% -152% 0.0 100% 0%0.020 0.007 0.013 0.003 0.017 51% 49% 8% 41% 0.0 169% -69%0.002 -0.002 0.003 0.000 93% 7% 8% -1%

0.008 79% 21% 0.0 125% -25%-0.006 0.011 -0.017 106% -6% 11% -17% 0.0 140% -40%

0.083 0.020 0.063 71% 29% 7% 22% -0.1 127% -27%-0.085 0.019 -0.104 144% -44% 10% -53% 0.0 87% 13%0.289 0.030 0.259 70% 30% 3% 27% -0.7 407% -307%0.032 0.011 0.021 67% 33% 12% 22% -0.1 250% -150%-0.010 146% -46% 0.0 67% 33.3%-0.021 184% -84% 0.0 80% 20%-0.014 121% -21% 0.0 100% 0%0.147 0.079 0.068 75% 25% 14% 12% 0.0 106% -6.0%0.085 0.027 0.057 33% 67% 21% 45% -0.1 390% -290.0%-0.003 0.037 -0.041 0.003 -0.006 104% -4% 4% -9% -0.1 310% -210%0.014 0.010 0.005 96% 4% 3% 1% 0.0 115% -15%-0.026 0.067 113% -12.7% 0.0 93% 7%0.161 0.005 0.156 81% 19% 1% 19% -0.3 167% -67%0.180 0.021 0.159 78% 22% 3% 19% 0.0 98% 2.5%0.096 0.086 92% 8% 0.1 92% 7.8%-0.156 0.005 -0.161 125% -25.2% 0.7% -25.9% 0.1 82% 18%0.019 0.016 0.003 78% 22% 18% 3%

0.004-0.003 0.004 -0.007 102% -2% 2% -4%-0.044 -0.070 0.010 -0.054 169% -69% 15% -84%0.003 0.003 0.000 89% 11% 10% 1% 0.0 88% 12%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present.

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Appendix D-2Cadmium Loading (lbs/day) Analysis by Segment

SAMPDAY

SUMMARYSPRING20052006200720082009201020112012AverageMinMax2008 wo 4/22/08Ave Yearly w/o 4/22/08

FALL20052006200720082009201020112012AverageMinMax

SPRINGMinMaxFALLMinMax

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

In SegmentBelow Cross

Creek (Minturn)

Upstream Segment Cross CreekNon Cross Creek Load

UpstreamAll

Percent of E-22 LoadSegment 5c

All

Loading by Sampling Station subsegments

Cross CreekNon-Cross

Creek

Percent of E-15 LoadSegment 5b

WTP and CTP WTP CTP

-0.013 -0.042 -0.031 -0.011 0.021 0.002 -0.014 118% -18% 2.0% -20% 0.0 111% -11%0.059 -0.109 0.027 -0.136 0.221 0.007 0.052 99% 1.3% 1.0% 0.3% 0.0 108% -8%0.034 0.001 0.040 0.005 0.029 89% 11% 2.4% 8.2% 0.0 121% -21%-0.254 0.017 0.100 0.005 -0.258 759% -659% 3.8% -663% -0.2 133% -33%0.070 0.020 0.051 98% 2.2% 7.6% -5.4% -0.2 190% -90%0.025 0.079 0.068 131% -31% 14% 12% 0.0 88% 12%0.070 0.037 0.076 -0.041 0.010 0.078 94% 6.1% 2.6% 7.7% 0.0 146% -46%-0.024 -0.070 0.006 -0.031 135% -35% 8.6% -44%-0.004 -0.019 0.000 -0.073 0.068 0.017 -0.003 190% -90% 5.2% -88% -0.1 128% -28%-0.254 -0.109 -0.070 -0.136 -0.041 0.002 -0.258 89% -659% 1.0% -663% -0.2 88% -90%0.070 0.037 0.076 -0.011 0.221 0.079 0.078 759% 11% 14% 12% 0.0 190% 12%

-0.324 -0.023 0.014 0.004 -0.329 855% -755% 4.3% -759% -0.2 134% -34%

-0.013 -0.027 0.000 -0.073 0.051 0.017 -0.012 202% -102% 5.3% -100% -0.1 128% -28%

-0.001 0.010 -0.001 0.011 -0.004 0.039 -0.007 223% -123% 22% -144% 0.0 90% 10.3%0.044 0.032 0.012 0.015 0.029 56% 44% 16% 28% 0.0 119% -19%0.009 0.003 0.006 0.006 0.002 62% 38% 28% 10% 0.0 100% 0%0.001 -0.007 -0.001 0.008 0.013 -0.012 118% -18% 37% -55% 0.0 135% -35%0.032 0.011 0.021 67% 33% 12% 22% -0.1 250% -150%0.085 0.027 0.057 33% 67% 21% 45% -0.1 390% -290.0%0.019 0.016 0.003 78% 22% 18% 3.2%0.003 0.003 0.000 89% 11% 10% 0.9% 0.0 88% 11.8%0.024 0.009 -0.001 0.011 0.006 0.016 0.012 91% 9.2% 21% -11% 0.0 167% -67%-0.001 -0.007 -0.001 0.011 -0.004 0.003 -0.012 33% -123% 10% -144% -0.1 88% -290%0.085 0.032 -0.001 0.011 0.012 0.039 0.057 223% 67% 37% 45% 0.0 390% 12%

Based on individual measurements from this table-2.875 -0.360 -0.070 -0.489 -0.041 0.001 -2.881 70% -5264% 0.3% -5276% -0.7 67% -307%0.488 0.057 0.129 0.011 0.679 0.079 0.479 5364% 30% 15% 27% 0.3 407% 33%

Based on individual measurements from this table-0.036 -0.021 -0.007 -0.003 -0.027 0.003 -0.042 33% -285% 7.9% -320% -0.1 29% -290%0.085 0.057 0.003 0.021 0.051 0.089 0.057 385% 67% 104% 45% 0.0 390% 71%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present.

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APPENDIX D-3

COPPER LOADING (LBS/DAY) ANALYSIS BY SEGMENT

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

1/14/2005 0.1 0.3 0.3 0.01 0.4 0.2 0.2 0.2 0.0 0.2 0.2 293/3/2005 0.4 0.0 0.2 0.2 273/10/2005 0.5 0.0 0.2 0.2 303/17/2005 0.7 0.8 0.9 0.1 0.9 0.4 0.4 0.2 0.0 0.5 0.2 293/24/2005 0.5 0.0 0.5 0.2 303/31/2005 0.6 0.0 0.6 0.5 314/3-5/05 2.3 2.9 2.5 1.7 1.2 1.1 414/12/2005 1.8 2.3 2.5 0.1 2.7 1.4 1.4 0.9 0.1 1.7 1.6 405/23/2005 18.5 19.6 20.8 0.3 21.1 20.6 14.6 16.6 4.6 20.8 19.4 7626/28/2005 1.6 1.6 1.6 1.8 5.1 2957/29/2005 1.1 0.9 1.0 0.5 0.4 848/25/2005 0.6 0.6 0.2 0.6 0.1 459/12/2005 0.2 0.4 0.5 0.0 0.5 0.4 0.4 0.2 0.1 0.2 0.2 339/22/2005 0.2 0.4 0.4 0.2 0.1 4010/18/2005 0.2 0.7 0.8 0.0 1.0 0.8 0.8 0.8 0.4 1.2 1.0 5010/25/2005 0.8 0.7 0.7 0.8 0.5 591/31/2006 0.2 1.0 0.7 0.0 0.9 0.3 0.1 0.4 0.3 273/9/2006 4.3 1.9 2.7 2.2 0.2 2.8 6.4 593/16/2006 1.0 0.1 1.0 2.1 383/23/2006 0.9 1.3 1.5 0.1 2.4 0.9 2.3 0.8 0.1 1.1 0.9 393/30/2006 1.4 0.1 1.8 1.4 424/6/2006 6.3 8.5 5.1 5.4 0.3 9.0 7.4 1134/12/2006 1494/20/2006 6.5 15.3 15.3 0.1 21.5 15.2 22.3 13.2 0.5 23.7 21.7 2174/26/2006 3095/22/2006 6.8 8.0 8.1 0.1 19.1 8.9 21.6 12.7 5.7 16.5 14.6 7139/27/2006 0.3 0.3 0.4 0.0 0.4 0.4 0.2 0.6 0.6 6910/23/2006 0.3 0.7 0.4 0.0 0.4 0.4 0.3 0.6 0.6 681/29/2007 0.1 0.4 0.4 0.0 0.4 0.2 0.0 0.2 0.2 303/2/2007 0.2 0.0 0.1 0.1 203/13/2007 0.6 0.1 0.6 0.2 323/20/2007 1.7 2.5 2.7 0.0 2.1 2.2 2.2 0.2 2.6 2.1 663/27/2007 3.1 2.9 2.8 0.2 3.2 2.9 754/3/2007 2.3 2.4 2.0 0.2 2.6 2.6 694/10/2007 5.6 5.6 5.0 0.3 6.0 5.7 1084/17/2007 2.1 4.0 4.2 0.0 5.0 4.1 4.1 0.1 5.1 4.6 1094/24/2007 7.1 6.9 5.4 0.4 6.7 6.4 1629/25/2007 0.3 0.3 0.3 0.0 0.3 0.3 0.3 0.5 0.5 5310/16/2007 0.8 0.3 0.3 0.0 0.3 0.3 0.1 0.4 0.4 491/28/2008 0.1 0.1 0.0 0.1 0.1 0.0 0.2 0.2 243/4/2008 0.6 0.1 0.5 0.4 253/11/2008 0.5 0.1 0.5 0.5 233/18/2008 0.7 0.1 0.7 0.5 233/25/2008 0.4 0.4 0.5 0.0 0.3 0.2 0.0 0.3 0.4 284/8/2008 0.8 0.1 0.9 0.8 314/15/2008 2.5 0.1 3.3 2.6 594/22/2008 7.2 12.9 13.1 0.0 10.9 11.3 0.4 14.0 12.3 1214/29/2008 11.9 0.5 16.2 13.9 1695/28/2008 7.7 14.1 14.2 0.1 14.4 15.4 16.6 4.2 21.7 730

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

6/24/2008 5.7 7.3 9.1 0.0 7.4 7.3 7.3 7.9 18.9 8467/29/2008 0.9 2.6 1.4 0.0 2.1 2.2 1.7 2.0 3.9 2678/27/2008 0.6 0.8 0.6 0.0 0.7 0.6 0.6 0.3 1.0 729/18/2008 0.1 0.5 0.5 0.0 0.5 0.4 0.4 0.1 0.5 449/29/2008 0.2 0.4 0.2 0.0 0.2 0.2 0.1 0.3 0.3 3710/20/2008 0.2 0.4 0.4 0.0 0.2 0.2 0.1 0.3 0.3 3210/22/2008 0.1 0.3 0.3 0.0 0.4 0.2 0.2 0.1 0.3 341/8/2009 0.3 0.2 0.2 322/19/2009 0.1 0.3 0.0 0.2 0.2 0.0 233/11/2009 0.4 1.0 0.0 0.6 0.1 0.4 0.4 253/20/2009 1.5 1.8 0.0 1.2 0.9 403/25/2009 1.2 1.8 0.0 1.6 0.2 2.0 2.0 474/8/2009 1.7 2.3 0.0 2.2 0.2 2.4 2.9 544/20/2009 2.6 4.4 0.0 4.2 0.3 4.9 3.9 919/23/2009 0.3 0.8 0.0 0.7 0.1 0.8 0.7 473/6/2010 0.4 0.0 0.3 0.2 0.6 183/17/2010 0.5 0.0 0.3 0.2 0.5 234/2/2010 0.7 0.0 0.6 0.5 0.9 314/15/2010 3.3 5.0 0.2 4.8 1.4 6.0 5.8 1239/24/2010 0.2 0.7 0.0 0.5 0.4 0.7 1.1 413/7/2011 0.6 0.0 0.6 1.2 0.1 1.7 1.1 323/21/2011 1.7 2.0 0.0 1.6 0.2 2.0 2.7 433/28/2011 0.8 0.8 1.1 404/4/2011 2.3 3.0 0.1 3.0 0.4 6.9 4.6 664/18/2011 2.8 4.9 0.2 6.8 0.7 7.2 10.5 1194/22/2011 9.8 9.7 13.3 1595/4/2011 4.4 4.8 0.1 4.8 0.2 5.0 8.3 9610/11/2011 0.2 0.6 0.0 0.3 0.3 0.4 513/12/2012 0.3 0.5 0.0 0.4 0.0 253/26/2012 1.1 1.5 0.0 1.9 0.2 2.3 854/10/2012 1.9 2.3 0.0 2.2 0.2 0.5 3.5 14410/18/2012 0.1 0.2 0.0 0.2 0.1 0.2 0.2 28

Notes:Load = calculated using the measured or surrogate concentration or half the detection limit for the day identified and the calculated or measured flow for the identified date. Spring = March and AprilFall = September through DecemberOnly zinc was analyzed for on 4/12/06 pr 4/26/06, not this metal

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

E- 3 E- 5 E-10 T-10 E-11 E-12A E-13 E-13B T-18 E-15 E-22

SAMPDAY

Loads at Sampling Stations

FLOW (E-12A)

SUMMARY See Appendix C for Summary by stationSPRING2005 0.6 0.7 0.62006 4.8 6.6 6.62007 2.8 3.4 3.12008 3.5 4.5 3.92009 2.0 2.4 2.02010 1.5 1.7 2.02011 3.8 5.4 4.82012 1.5 2.9Average 2.6 3.4 3.3Min 0.6 0.7 0.6Max 4.8 6.6 6.62008 wo 4/22/08

2.5 3.2 2.7

Ave Yearly w/o 4/22/08 2.4 3.3 3.1

FALL2005 0.6 0.7 0.62006 0.4 0.6 0.62007 0.3 0.4 0.42008 0.3 0.4 0.32009 0.7 0.8 0.72010 0.5 0.7 1.12011 0.3 0.42012 0.2 0.2 0.2Average 0.4 0.5 0.6Min 0.2 0.2 0.2Max 0.7 0.8 1.1

SPRING Based on individual measurements from this tableMin 0.2 0.1 0.1Max 15.2 23.7 21.7FALL Based on individual measurements from this tableMin 0.2 0.2 0.2Max 0.8 1.2 1.1

Notes:Load = calculated using the measured or surrogate concentration or half the detection limit for the day identified and the calculated or measured flow for the identified date. Spring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at a sampling station (see Appendix C)

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

1/14/20053/3/20053/10/20053/17/20053/24/20053/31/20054/3-5/054/12/20055/23/20056/28/20057/29/20058/25/20059/12/20059/22/200510/18/200510/25/20051/31/20063/9/20063/16/20063/23/20063/30/20064/6/20064/12/20064/20/20064/26/20065/22/20069/27/200610/23/20061/29/20073/2/20073/13/20073/20/20073/27/20074/3/20074/10/20074/17/20074/24/20079/25/200710/16/20071/28/20083/4/20083/11/20083/18/20083/25/20084/8/20084/15/20084/22/20084/29/20085/28/2008

SAMPDAY EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

0.1 0.0 0.2 0.1 0.0 -0.2 0.0 0.01 0.0 -0.2 -0.2 88% 123% 95% 28.5% -111% 7.2% 17% -119% -136%0.40.5

0.7 -0.3 0.2 0.1 0.2 -0.6 0.0 0.1 -0.1 -0.6 -0.6 188% 69% 24% 45% -157% 19% -15% -176% -161%0.50.6

2.3 0.61.8 -0.4 0.6 0.5 0.2 -1.0 0.3 0.1 0.1 -1.2 -1.3 127% 44% 33% 11% -71% 10% 8% -81% -89%18.5 2.1 2.4 1.1 1.3 -0.3 0.3 0.3 0.0 -0.6 -0.6 90% 12% 6% 6% -1% 2% 0% -3% -3%

1.6 0.0 -2%0.9 -0.2 -19%0.6 0.0 -5%

0.2 0.2 0.3 0.3 0.1 -0.1 0.0 0.0 -0.1 -0.2 -0.1 44% 98% 79% 19% -42% 12% -25% -53% -28%0.4 0.2 47%

0.2 0.5 0.5 0.5 0.0 0.0 0.3 0.0 0.3 0.0 -0.3 32% 69% 65% 4.4% -1% 2% 34% -2% -36%0.7 0.0 -4%

0.2 0.7 0.5 0.8 -0.3 0.2 0.0 0.1 23% 56% 85% -29% 21% 5% 15%1.9 -2.4 -126%1.0

0.9 0.0 0.6 0.4 0.2 -0.6 1.0 0.1 0.9 -0.7 -1.5 101% 64% 40% 24% -65% 9% 96.2% -74% -170%1.48.5 2.3 27%

6.5 8.7 8.8 8.8 0.0 -0.1 6.2 0.1 6.1 -0.2 -6.3 43% 58% 58% 0% -1% 0% 40% -1% -41%

6.8 2.0 1.3 1.1 0.1 0.8 11.1 0.1 11.0 0.7 -10.3 77% 14% 13% 1% 9% 1% 124% 8% -116%0.3 0.1 0.1 0.0 0.0 0.0 0.0 0.0 83% 17% 5% 12% 0% 0% 0%0.3 0.0 0.1 0.4 -0.3 0.0 0.0 0.0 88% 14% 103% -89% -2% 3% -6%0.1 0.2 0.3 0.2 0.0 0.0 0.0 -0.1 39% 73% 62% 11% -12% 7% -19%

0.20.6

1.7 0.5 1.0 0.8 0.3 -0.5 -0.6 0.0 -0.6 -0.5 0.1 76% 46% 35% 11% -22% 0% -27% -23% 4%2.8 3.1 -0.3 -0.2 -0.1 110% -10% -4%2.0 2.3 -0.3 0.1 -0.4 114% -14% -17%5.0 5.6 -0.6 0.0 -0.6 112% -12% -12%

2.1 1.9 2.0 1.8 0.2 -0.1 0.8 0.0 0.8 -0.1 -0.9 52% 50% 44% 5% -2% 1% 20% -3% -23.0%5.4 7.1 -1.6 -0.2 -1.5 130% -30% -27%

0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 93% 15% 2% 13% -9% 1% -10%0.8 -0.6 -0.5 -0.6 0.0 0.0 0.0 0.0 311% -202% -216% 14% -9% 4% -13.2%

0.1 0.1 0.1 0.0 0.0 0.0 0.0 107% 86% 21% -7% 0% -7%0.60.50.7

0.4 0.0 0.2 0.1 0.1 -0.2 0.0 -0.2 102% 54% 25% 29.2% -56.1% 0.8% -57%0.82.5

7.2 3.7 5.9 5.7 0.2 -2.2 0.0 -2.3 66% 54% 52% 2% -20% 0% -21%11.9

7.7 7.7 6.5 6.4 0.1 1.2 0.2 0.1 0.1 1.1 1.0 50% 42% 42% 1% 8% 1% 1% 7% 6%

Groundwater Rock Crk GWRex Flats

UpstreamBelden Segment

All

Belden Segment Lower Segment Percent of E-12A Load

EntireAbove

Fall Crk

Upstream Segment 2

Segment 5a

Lower SegmentBelow

Fall CreekEntire

RockCreek

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

SAMPDAY

6/24/20087/29/20088/27/20089/18/20089/29/200810/20/200810/22/20081/8/20092/19/20093/11/20093/20/20093/25/20094/8/20094/20/20099/23/20093/6/20103/17/20104/2/20104/15/20109/24/20103/7/20113/21/20113/28/20114/4/20114/18/20114/22/20115/4/201110/11/20113/12/20123/26/20124/10/201210/18/2012

EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

Groundwater Rock Crk GWRex Flats

UpstreamBelden Segment

All

Belden Segment Lower Segment Percent of E-12A Load

EntireAbove

Fall Crk

Upstream Segment 2

Segment 5a

Lower SegmentBelow

Fall CreekEntire

RockCreek

5.7 1.6 3.5 1.6 1.8 -1.8 -1.7 0.0 -1.7 -1.9 -0.1 77% 48% 22% 25% -25% 0% -24% -25% -1%0.9 1.3 0.6 1.7 -1.1 0.7 0.6 0.0 0.6 0.7 0.1 41% 26% 77% -51% 33% 0% 28% 33% 5%0.6 0.0 0.0 0.2 -0.2 0.0 0.1 0.0 0.1 0.0 -0.1 100% 2% 40% -38% -2% 1% 14% -3% -17%0.1 0.3 0.3 0.4 0.0 0.0 0.0 0.0 0.0 0.0 -0.1 32% 78% 87% -10% -9% 0% 7% -10% -17%0.2 0.0 0.0 0.2 -0.2 0.0 0.0 0.0 88% 16% 104% -87.9% -4% 0% -5%0.2 0.1 0.2 0.2 0.0 -0.1 0.0 -0.1 70% 77% 97% -20% -47% 0% -47%0.1 0.1 0.2 0.2 0.0 -0.1 0.1 0.0 0.1 -0.1 -0.2 44% 93% 78% 15% -37% 0% 34% -37% -72%

0.2 0.3 -0.1 144% -44%0.1 0.1 0.2 -0.1 0.0 -0.1 64% 111% -75% 0% -76%0.4 0.2 0.6 -0.4 0.0 -0.4 70% 103% -73% 1% -74%1.5 -0.3 0.2 -0.5 0.0 -0.5 124% 20% -44% 0% -44%1.2 0.4 0.6 -0.2 0.0 -0.3 75% 41% -16% 0% -16%1.7 0.6 0.6 0.0 0.0 -0.1 75% 27% -2% 0% -2%2.6 1.6 1.8 -0.2 0.0 -0.2 63% 43% -5% 1% -6%0.3 0.4 0.5 -0.1 0.0 -0.1 36% 71% -7% 1% -8%

0.3 0.4 -0.1 0.0 -0.1 141% -41% 2% -43%0.3 0.5 -0.1 0.0 -0.2 146% -46% 3% -49%0.6 0.7 -0.1 0.0 -0.1 123% -23% 1% -24%

3.3 1.4 1.6 -0.2 0.2 -0.4 70% 34% -4% 4% -8%0.2 0.3 0.5 -0.2 0.0 -0.2 38% 102% -40% 0% -40%

0.6 0.6 0.0 0.0 0.0 102% -2% 4% -6%1.7 -0.1 0.3 -0.5 0.0 -0.5 109% 21% -30% 2% -32.1%

0.82.3 0.7 0.7 0.0 0.1 -0.1 78% 22% 0% 2% -2%2.8 4.0 2.1 1.9 0.2 1.7 42% 31% 27% 2% 25%

9.84.4 0.5 0.4 0.0 0.1 0.0 90% 9% 1% 2% -1%0.2 0.0 0.3 -0.3 0.0 -0.3 88% 118% -106% 3% -109%0.3 0.1 0.2 -0.1 0.0 -0.1 85% 51% -35% 1% -37%1.1 0.8 0.5 0.3 0.0 0.3 56% 26% 18% 2% 15.9%1.9 0.3 0.4 -0.1 0.0 -0.1 85% 19% -5% 2% -6%0.1 0.0 0.0 0.0 0.0 0.0 88% 18% -6% 2% -8%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present,with the exception of E-3. If E-3 was not sampled the Loading presented from E-3 to a designated station is the load from that designated station.

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

SAMPDAY

SUMMARYSPRING20052006200720082009201020112012AverageMinMax2008 wo 4/22/08Ave Yearly w/o 4/22/08

FALL20052006200720082009201020112012AverageMinMax

SPRINGMinMaxFALLMinMax

EntireSurface Water

EntireAbove

Fall CrkBelow

Fall CreekEntire Rock Crk

Rex Flats

E-3E-3 to E-12A

E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

E-10 to E-11

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

E-3E-3 to E-10

E-3 to E-5

E-5 to E-10

E-10 to E-12A

T-10

E-10 to E-11 minus T-10

E-10 to E-12A minus T-10

E-11 to E-12A

Groundwater Rock Crk GWRex Flats

UpstreamBelden Segment

All

Belden Segment Lower Segment Percent of E-12A Load

EntireAbove

Fall Crk

Upstream Segment 2

Segment 5a

Lower SegmentBelow

Fall CreekEntire

RockCreek

1.6 0.2 0.4 0.4 0.2 -0.8 0.1 0.1 0.0 -0.9 -0.9 157% 57% 28% 28% -114% 14% -3% -128.2% -125%3.7 3.6 4.7 4.6 0.1 -0.3 3.6 0.1 3.5 -0.4 -2.0 72% 61% 49% 12% -33% 5% 68.2% -38% -78%1.9 2.3 3.5 1.3 0.2 -0.6 0.0 0.0 0.1 -0.3 -0.6 64% 94% 40% 8% -15% 1% -4% -13% -13%3.8 2.6 3.1 2.9 0.2 -1.2 0.0 -1.2 84% 54% 39% 16% -38% 1% -39%1.5 0.5 0.8 -0.3 0.0 -0.3 81% 47% -28% 0% -28%3.3 0.7 0.8 -0.1 0.0 -0.2 70% 111% -28% 2% -31%2.3 2.6 0.9 0.3 0.1 0.3 76% 44% -1% 3% -4%1.1 0.4 0.4 0.0 0.0 0.0 75% 32% -7% 2% -9%2.4 1.6 1.8 2.3 0.2 -0.4 1.2 0.0 1.2 -0.4 -1.2 85% 62% 39% 16% -33% 3% 21% -36% -72.0%1.1 0.2 0.4 0.4 0.1 -1.2 0.0 0.0 0.0 -1.2 -2.0 64% 32% 28% 8% -114% 0% -3.6% -128% -125%3.8 3.6 4.7 4.6 0.2 0.3 3.6 0.1 3.5 0.3 -0.6 157% 111% 49% 28% -1% 14% 68% -4% -13%

0.4 2.4 0.2 0.1 0.1 -0.2 0.0 -0.2 102% 54% 25% 29% -56% 1% -57%

2.0 1.6 1.5 1.6 0.2 -0.2 1.2 0.0 1.2 -0.3 -1.2 87% 62% 36% 19% -35% 4% 21% -38% -72.0%

0.2 0.5 0.4 0.4 0.0 -0.1 0.1 0.0 0.1 -0.1 0.0 38% 83% 72% 11% -21% 7% 4% -28% -5%0.3 0.1 0.1 0.2 -0.1 0.0 0.0 0.0 86% 15% 54% -39% -1% 2% -3%0.5 -0.3 -0.2 -0.3 0.0 0.0 0.0 0.0 202% -93% -107% 13% -9% 2% -11%0.1 0.1 0.2 0.3 -0.1 -0.1 0.1 0.0 0.1 -0.1 -0.1 59% 66% 91% -26% -25% 0% 21% -25% -44%0.3 0.4 0.5 -0.1 0.0 -0.1 36% 71% -7% 1% -8%0.2 0.3 0.5 -0.2 0.0 -0.2 38% 102% -40% 0% -40%0.2 0.0 0.3 -0.3 0.0 -0.3 88% 118% -106% 3% -109%0.1 0.0 0.0 0.0 0.0 0.0 88% 18% -6% 2% -8%0.3 0.1 0.2 0.1 0.0 -0.1 0.1 0.0 0.1 -0.1 -0.1 80% 47% 28% -10% -27% 2% 12% -29% -25%0.1 -0.3 -0.2 -0.3 -0.1 -0.3 0.1 0.0 0.1 -0.3 -0.1 36% -93% -107% -39% -106% 0% 4% -109% -44%0.5 0.5 0.5 0.4 0.0 0.0 0.1 0.0 0.1 0.0 0.0 202% 118% 91% 13% -1% 7% 21% -3% -5%

Based on individual measurements from this table0.3 -0.4 0.2 0.1 0.0 -2.2 -0.6 0.0 -0.6 -2.3 -6.3 42% 19% 24% 0% -157% 0% -27% -176% -170%7.2 11.9 8.8 8.8 0.3 1.9 6.2 0.2 6.1 1.7 2.3 188% 146% 58% 45% 27% 19% 96% 25% 27%

Based on individual measurements from this table0.1 -0.6 -0.5 -0.6 -0.3 -0.3 0.0 0.0 -0.1 -0.3 -0.3 32% -202% -216% -89% -106% 0% -25% -109% -72%0.8 0.7 0.5 0.5 0.1 0.0 0.3 0.0 0.3 0.0 0.2 311% 118% 104% 19% 0% 12% 34% 0% 47%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present,with the exception of E-3. If E-3 was not sampled the Loading presented from E-3 to a designated station is the load from that designated station.

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

1/14/20053/3/20053/10/20053/17/20053/24/20053/31/20054/3-5/054/12/20055/23/20056/28/20057/29/20058/25/20059/12/20059/22/200510/18/200510/25/20051/31/20063/9/20063/16/20063/23/20063/30/20064/6/20064/12/20064/20/20064/26/20065/22/20069/27/200610/23/20061/29/20073/2/20073/13/20073/20/20073/27/20074/3/20074/10/20074/17/20074/24/20079/25/200710/16/20071/28/20083/4/20083/11/20083/18/20083/25/20084/8/20084/15/20084/22/20084/29/20085/28/2008

SAMPDAY

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

0.1 0.0 0.0 0.0 0.0 0.0 0.0 74% 26% 13% 13% 0.0 100% 0%-0.2 0.0 -0.2 203% -103% 13% -116% 0.0 100% 0%-0.3 0.0 -0.3 234% -134% 11% -144.9% 0.0 100% 0%0.1 -0.2 0.0 -0.2 0.3 0.0 0.1 77% 23% 5% 18% -0.3 220% -120%0.0 0.0 0.0 101% -1% 6% -7% -0.2 210% -110%-0.1 0.0 -0.1 110% -10% 6% -15.9% 0.0 109% -9%

-0.1 107% -7%0.3 -0.6 -0.1 -0.5 0.9 0.1 0.2 83% 17% 4% 13% -0.1 106% -6%0.2 -4.0 -6.0 2.0 4.2 4.6 -4.4 99% 1% 22% -21% -1.4 107% -7.4%

0.2 0.0 0.2 5.1-0.4 0.1 -0.5 0.40.0 -0.3 0.4 0.1

-0.1 -0.2 0.0 -0.2 0.0 0.1 -0.2 143% -43% 35% -77% 0.0 100% 0%-0.2 0.0 -0.2 0.1

0.4 0.0 0.0 0.0 0.4 0.4 0.0 64% 36% 37% -1.3% -0.1 114% -14%0.1 -0.1 0.1 0.5

-0.5 -0.5 0.1 0.1 -0.5 202% -102% 12% -114% -0.1 127% -27%0.9 0.3 0.8 -0.5 0.6 0.2 0.7 68% 32% 6% 26% 3.6 44% 56%0.1 0.1 0.0 95% 5% 7% -2% 1.0 50% 50.0%0.2 -0.1 1.4 -1.6 0.3 0.1 0.1 85% 15% 7% 8% -0.2 121% -21%0.4 0.1 0.3 79% 21% 5% 15.7% -0.3 123% -23%0.4 -3.1 -3.4 0.3 3.6 0.3 0.2 95% 5% 3% 2.1% -1.6 122% -22%

8.4 -2.0 7.0 -9.1 10.5 0.5 7.9 64% 36% 2% 33% -2.0 109% -9%

7.7 3.9 12.7 -8.8 3.8 5.7 2.0 54% 46% 34% 12% -2.0 114% -14%0.2 0.0 0.2 0.2 0.1 64% 36% 28% 9% 0.0 100% 0%0.2 0.0 0.2 0.3 -0.1 64% 36% 58% -22% 0.0 100% 0%-0.1 -0.2 0.0 0.0 -0.2 167% -67% 11% -77% 0.0 100% 0%-0.1 0.0 -0.1 176% -76% 16% -92% 0.0 100% 0%0.0 0.1 -0.1 99% 1% 10% -9% -0.4 253% -153%0.4 0.0 0.4 0.2 0.2 85% 15% 8% 7% -0.5 123% -23%0.4 0.2 0.2 88% 12% 7% 5% -0.3 110% -10%0.6 0.2 0.4 78% 22% 8% 14% 0.0 100% 0%0.9 0.3 0.7 84% 16% 4% 11% -0.3 105% -5%1.0 0.0 1.0 0.1 0.9 80% 20% 2% 18% -0.6 112% -12%1.3 0.4 0.9 81% 19% 7% 13% -0.3 105% -5%0.2 0.1 0.1 0.3 -0.1 62% 38% 69% -31% 0.0 100% 0%0.2 0.1 0.1 0.1 0.1 62% 38% 23% 15% 0.0 100% 0%0.0 0.0 0.0 0.0 0.0 78% 22% 17% 5% 0.0 100% 0%-0.2 0.1 -0.3 135% -35% 25% -60% 0.0 104% -4%0.1 0.1 -0.1 87% 12.9% 23.2% -10% 0.0 105% -5%0.0 0.1 -0.1 98% 2% 16% -14% -0.2 138% -38%0.0 -0.1 0.1 0.0 -0.1 108% -8.4% 12.4% -21% 0.0 90% 10%0.1 0.1 0.0 91% 9% 6% 2% -0.1 118% -18%0.8 0.1 0.7 76% 23.7% 2.7% 21% -0.7 127% -27%3.1 0.4 2.7 0.4 2.7 78% 22% 3% 20% -1.7 114% -14%4.3 0.5 3.8 73% 26.6% 2.8% 24% -2.3 117% -17%6.3 1.2 4.2 2.1 71% 29% 19% 10%

In SegmentBelow Cross

Creek (Minturn)

Upstream Segment Cross CreekNon Cross Creek Load

UpstreamAll

Percent of E-22 LoadSegment 5c

All

Loading by Sampling Station subsegments

Cross CreekNon-Cross

Creek

Percent of E-15 LoadSegment 5b

WTP and CTP WTP CTP

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

SAMPDAY

6/24/20087/29/20088/27/20089/18/20089/29/200810/20/200810/22/20081/8/20092/19/20093/11/20093/20/20093/25/20094/8/20094/20/20099/23/20093/6/20103/17/20104/2/20104/15/20109/24/20103/7/20113/21/20113/28/20114/4/20114/18/20114/22/20115/4/201110/11/20113/12/20123/26/20124/10/201210/18/2012

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

In SegmentBelow Cross

Creek (Minturn)

Upstream Segment Cross CreekNon Cross Creek Load

UpstreamAll

Percent of E-22 LoadSegment 5c

All

Loading by Sampling Station subsegments

Cross CreekNon-Cross

Creek

Percent of E-15 LoadSegment 5b

WTP and CTP WTP CTP

11.6 0.0 7.9 3.7 39% 61% 42% 19%1.7 -0.4 2.0 -0.3 55% 45% 52% -7.1%0.4 0.0 0.3 0.1 59% 41% 31% 9%0.1 0.0 0.1 0.0 87% 13% 23% -10%0.1 0.0 0.1 0.1 0.0 70% 30% 28% 2% 0.0 100% 0%0.1 -0.1 0.1 0.1 0.0 79% 21% 32% -11% 0.0 91% 9%0.1 0.0 0.1 0.0 77% 23% 19% 5%

0.0 83% 17% -0.2 30600% -30500%-0.1 0.1 -0.2 131% -31% 23% -54% -0.1 115% -15%

0.4 0.2 0.2 80% 20% 9% 10% 0.0 98% 2%0.1 0.2 0.0 94% 6% 7% -1% 0.5 82% 18%0.7 0.3 0.3 87% 13% 6% 7% -1.0 125% -25%0.1 0.1 0.0 88% 12% 9% 3% -0.1 110% -10%-0.1 131% -31% 0.4 38% 62.5%-0.2 199% -99% 0.4 30% 70%-0.1 113% -13% 0.4 59% 41%1.2 1.4 -0.2 80% 20% 24% -3% -0.2 104% -3.8%0.2 0.4 -0.2 71% 29% 50% -22% 0.4 65% 35.3%1.2 0.7 0.5 0.1 1.1 32% 68% 6% 62% -0.6 153% -53%0.4 0.2 0.3 78% 22% 8% 14% 0.7 74% 26%0.3 -0.1 77% 23.5%3.9 0.4 3.5 44% 56% 6% 50% -2.2 148% -48%0.4 0.7 -0.3 95% 5% 10% -5% 3.4 68% 32.0%3.5 -0.1 74% 26%0.2 0.2 0.0 96% 4.3% 3.8% 0.5% 3.3 61% 39%0.1 0.3 -0.2 66% 34% 74% -39%

0.00.4 0.2 0.2 82% 18% 9% 9%1.3 -2.0 0.5 0.8 63% 37% 16% 22%0.1 0.1 0.0 74% 26% 29% -4% 0.0 100% 0%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present.

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Appendix D-3Copper Loading (lbs/day) Analysis by Segment

SAMPDAY

SUMMARYSPRING20052006200720082009201020112012AverageMinMax2008 wo 4/22/08Ave Yearly w/o 4/22/08

FALL20052006200720082009201020112012AverageMinMax

SPRINGMinMaxFALLMinMax

E-12A to E-15

E-12A to E-13B

E-12A to E-13

E-13 to E-13B

E-13B to E-15

T-18E-12A to E-15

minus T-18

E-12A E-12A to E-15 T-18E-12A to E-15

minus T-18

E-15 to E-22

E-15E-15 to E-22

In SegmentBelow Cross

Creek (Minturn)

Upstream Segment Cross CreekNon Cross Creek Load

UpstreamAll

Percent of E-22 LoadSegment 5c

All

Loading by Sampling Station subsegments

Cross CreekNon-Cross

Creek

Percent of E-15 LoadSegment 5b

WTP and CTP WTP CTP

0.0 -0.4 0.0 -0.3 0.6 0.0 -0.1 135% -35% 7% -42% -0.1 136% -36%1.7 -1.3 1.4 -2.7 3.7 0.2 1.5 81% 19.0% 5% 14% 0.1 95% 5%0.6 0.0 0.7 0.2 0.4 96% 4% 8% -4% -0.3 126% -26%1.0 0.1 1.4 0.2 0.9 93% 7% 11% -5% -0.6 114% -14%0.3 0.2 0.1 98% 2% 11% -9% -0.1 105% -5%0.2 1.4 -0.2 131% -31% 24% -3% 0.2 58% 42%1.6 0.7 -0.1 0.5 0.3 1.1 66% 34% 7% 30% 0.3 111% -11%0.9 -2.0 0.3 0.5 72% 28% 12% 15%0.8 -0.2 -0.2 -1.5 1.4 0.4 0.5 97% 3% 11% 0% -0.1 106% -6%0.0 -1.3 -2.0 -2.7 0.5 0.0 -0.2 66% -35% 5% -42% -0.6 58% -36%1.7 0.7 1.4 -0.3 3.7 1.4 1.5 135% 34% 24% 30% 0.3 136% 42%

0.7 -0.1 0.1 0.1 0.6 96% 4% 13% -8% -0.5 114% -14%

0.7 -0.2 -0.2 -1.5 1.1 0.3 0.5 1.0 0.0 0.1 0.0 -0.1 106% -6%

0.2 -0.1 0.0 -0.1 0.2 0.3 -0.1 103% -3% 36% -39% -0.1 107% -6.8%0.2 0.0 0.2 0.2 0.0 64% 36% 43% -6% 0.0 100% 0%0.2 0.1 0.1 0.2 0.0 62% 38% 46% -8% 0.0 100% 0%0.1 0.0 0.0 0.1 0.1 0.0 78% 22% 25% -3% 0.0 96% 4%0.1 0.1 0.0 88% 12% 9% 3% -0.1 110% -10%0.2 0.4 -0.2 71% 29% 50% -22% 0.4 65% 35.3%0.1 0.3 -0.2 66% 34% 74% -39%0.1 0.1 0.0 74% 26% 29% -4% 0.0 100% 0.0%0.1 0.0 0.0 -0.1 0.2 0.2 -0.1 76% 24% 39% -15% 0.0 97% 3%0.1 -0.1 0.0 -0.1 0.1 0.1 -0.2 62% -3% 9% -39% -0.1 65% -10%0.2 0.1 0.0 -0.1 0.2 0.4 0.0 103% 38% 74% 3% 0.4 110% 35%

Based on individual measurements from this table-0.3 -3.1 -3.4 -9.1 0.1 0.0 -0.3 32% -134% 2% -145% -2.3 30% -153%8.4 0.7 7.0 0.3 10.5 1.4 7.9 234% 68% 25% 62% 3.6 253% 70%

Based on individual measurements from this table-0.1 -0.2 -0.1 -0.2 0.0 0.1 -0.2 62% -43% 9% -77% -0.1 65% -14%0.4 0.1 0.0 0.1 0.4 0.5 0.1 143% 38% 74% 15% 0.4 114% 35%

Notes:Loading is defined as the difference in load between two measured stationsSpring = March and AprilFall = September through DecemberSummary calculated on loads presented in this table and do not reflect all samples collected at each sampling station (see Appendix C) but only those loads where data from both sampling stations are present.

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APPENDIX E

PHOTOGRAPHS

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APPENDIX F

COST ESTIMATES

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Item Notes Quantity Unit Unit Cost Total Cost

None

TOTAL CAPITAL COSTS -$

OPERATING AND MAINTENANCE (O&M) COSTS

Groundwater and surface water sampling a 1 year 20,000.00$ 20,000$ Operation and Maintenance b 1 year 40,000.00$ 40,000$ Water Treatment c 1 year 642,000.00$ 642,000$ Project Management d 1 year 105,300.00$ 105,300$

TOTAL ANNUAL O&M COSTS 807,300$

TOTAL 30-YEAR COSTS (non-discounted) 25,026,300$ Present Worth Value (see following table at 7% discount) 10,825,000$

NotesUnless identified separately burden and profits are included in unit costs.

abcd 15% of annual costs

TABLE F-1

DETAILED COST ESTIMATE

Cost estimate from FCEMS, 2007 WTP cost per gallon = $0.006 at 107,604,000 gallons in 2008

Alternative 1 - No Added Action

CAPITAL COSTS

Budget for 2009 monitoring; labor included with Project ManagementApproximate 2008 expenditures

AppendixF_Alternatives Cost rev6.xls Alt 1

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TABLE F-1 (cont.)

PRESENT WORTH ANALYSIS

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $0 $807,300 $807,300 1.0000 $807,300 1.0000 $807,300 1.0000 $807,3001 $807,300 $807,300 0.9709 $783,786 0.9346 $754,486 0.9091 $733,9092 $807,300 $807,300 0.9426 $760,958 0.8734 $705,127 0.8264 $667,190

3 $807,300 $807,300 0.9151 $738,794 0.8163 $658,997 0.7513 $606,5364 $807,300 $807,300 0.8885 $717,276 0.7629 $615,885 0.6830 $551,3975 $807,300 $807,300 0.8626 $696,384 0.7130 $575,594 0.6209 $501,2706 $807,300 $807,300 0.8375 $676,101 0.6663 $537,938 0.5645 $455,7007 $807,300 $807,300 0.8131 $656,409 0.6227 $502,746 0.5132 $414,2738 $807,300 $807,300 0.7894 $637,290 0.5820 $469,856 0.4665 $376,6119 $807,300 $807,300 0.7664 $618,728 0.5439 $439,118 0.4241 $342,37410 $807,300 $807,300 0.7441 $600,707 0.5083 $410,390 0.3855 $311,24911 $807,300 $807,300 0.7224 $583,211 0.4751 $383,542 0.3505 $282,95412 $807,300 $807,300 0.7014 $566,224 0.4440 $358,451 0.3186 $257,23113 $807,300 $807,300 0.6810 $549,732 0.4150 $335,001 0.2897 $233,84614 $807,300 $807,300 0.6611 $533,720 0.3878 $313,085 0.2633 $212,58715 $807,300 $807,300 0.6419 $518,175 0.3624 $292,603 0.2394 $193,26116 $807,300 $807,300 0.6232 $503,083 0.3387 $273,460 0.2176 $175,69217 $807,300 $807,300 0.6050 $488,430 0.3166 $255,571 0.1978 $159,72018 $807,300 $807,300 0.5874 $474,204 0.2959 $238,851 0.1799 $145,20019 $807,300 $807,300 0.5703 $460,392 0.2765 $223,225 0.1635 $132,00020 $807,300 $807,300 0.5537 $446,982 0.2584 $208,622 0.1486 $120,00021 $807,300 $807,300 0.5375 $433,964 0.2415 $194,974 0.1351 $109,09122 $807,300 $807,300 0.5219 $421,324 0.2257 $182,218 0.1228 $99,17423 $807,300 $807,300 0.5067 $409,052 0.2109 $170,297 0.1117 $90,15824 $807,300 $807,300 0.4919 $397,138 0.1971 $159,156 0.1015 $81,96225 $807,300 $807,300 0.4776 $385,571 0.1842 $148,744 0.0923 $74,51126 $807,300 $807,300 0.4637 $374,341 0.1722 $139,013 0.0839 $67,73727 $807,300 $807,300 0.4502 $363,438 0.1609 $129,919 0.0763 $61,57928 $807,300 $807,300 0.4371 $352,852 0.1504 $121,420 0.0693 $55,98129 $807,300 $807,300 0.4243 $342,575 0.1406 $113,476 0.0630 $50,89230 $807,300 $807,300 0.4120 $332,597 0.1314 $106,053 0.0573 $46,265

$25,026,300

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $16,631,000 $10,825,000 $8,418,000

Ongoing Costs include annual O&M costs and periodic costs

Alternative 1 - No Further Action

Non-discounted cost:

AppendixF_Alternatives Cost rev6.xls PW alt 1

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Item Notes Quantity Unit Unit Cost Total Cost

Direct Construction4" perforated HDPE pipe (installed) a,b 700 lf 8.00$ 5,600$ Cleanout (installed) a,c 4 each 100.00$ 400$ Trench excavation a,d 1,800 lf 65.00$ 117,000$ Trench membrane liner 1,166 sy 5.00$ 5,830$ Place excess excavated soil in trench 11,000 cy 3.50$ 38,500$ Geotextile filter around drainage rock a 700 lf 2.50$ 1,750$ Load Backfill a 1,000 cy 9.50$ 9,500$ Haul Backfill a,e 1,000 cy 4.50$ 4,500$ Place Backfill a,f 1,000 cy 3.50$ 3,500$ 4" connecting surface pipe to existing pipeline at Rock Creek a,g 1,100 lf 3.50$ 3,850$ Remove and dispose of existing tracks i 1,000 lf 15.00$ 15,000$ Replace railroad tracks i 1,000 lf 75.00$ 75,000$ Dewatering j 3 weeks 500.00$ 1,500$ Excavate temporary sediment retention pond a,k 1,000 cy 2.50$ 2,500$ Line sediment retention pond a 750 sy 3.00$ 2,250$ Hookup to existing Pipeline at Rock Creek manhole l 1 lump 1,000.00$ 1,000$ Remove temporary sediment retention pond l 1 lump 2,000.00$ 2,000$ Drain Mill Level to main pipeline l 1 lump 1,000.00$ 1,000$ Direct Construction Subtotal 290,680$

Indirect ConstructionMobilization/Demobilization l 6% 17,441$ Engineering Design m 10% 30,812$ Project/Construction Management m 15% 46,218$ Indirect Construction Subtotal 94,471$

TOTAL CAPITAL COSTS 385,151$

OPERATING AND MAINTENANCE (O&M) COSTS

Alternative Required O&MOperation and Maintenance 1 year 1,500.00$ 1,500$ Additional Water Treatment Costs, WTP h 1 year 12,960.00$ 12,960$ Alternative Required O&M 14,460$

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 year 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 year 40,000.00$ 40,000$ Water Treatment see Alt 1 1 year 642,000.00$ 642,000$ Project Management see Alt 1 1 year 105,300.00$ 105,300$ Alternative 1 O&M 807,300$

TOTAL ANNUAL O&M COSTS 821,760$

TOTAL 30-YEAR COSTS (non-discounted) 25,845,251$ Present Worth Value (see following table at 7% discount) 11,390,000$

NotesUnless identified separately burden and profits are included in unit costs.

abcd

efghijklm Based off direct construction costs and mob/demob costs

DETAILED COST ESTIMATE

TABLE F-2

Alternative 2A - Groundwater Collection and Treatment, Belden and Rock Creek

CAPITAL COSTS

Cost from Means, 2005Standard HDPE pipe similar in cost to perforated PVC, used perforated PVC installation cost.Assume cleanout consists of t-joint with HDPE riser and end capCost assumes 3 foot bottom width of trench w/ vertical sides, 15 ft depth at Belden shallowing in downstream direction. Length includes Tramway extension of 50 ft. Assumes 1.5 mile round trip and 12 cy end dump; RT Rock CreekPrice for bedding and backfill gravel is not included, uses WP-11 gravel from Rock Creek

Size is adequate to store 2+ days dewatering @ 60gpmEstimate

Assumes 4" HDPE non-perforated pipe. Pipe will transmit at least 60 gpm on a slope of .0136Cost estimate from FCEMS, 2007 WTP cost per gallon = $0.006 at 25 gpm for 60 days; the cost of operating the well at Rock Creek Costs based on Illinois Department of Transportation FY 1998 Proposed Rail Improvement Program SupplementAssumes use of 6" trash pump

AppendixF_Alternatives Cost rev6.xls Alt 2A

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TABLE F-2 (cont.)

Alternative 2A - Groundwater Collection and Treatment, Belden and Rock Creek

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $385,151 $807,300 $1,192,451 1.0000 $1,192,451 1.0000 $1,192,451 1.0000 $1,192,4511 $821,760 $821,760 0.9709 $797,825 0.9346 $768,000 0.9091 $747,0552 $821,760 $821,760 0.9426 $774,588 0.8734 $717,757 0.8264 $679,1403 $821,760 $821,760 0.9151 $752,027 0.8163 $670,801 0.7513 $617,4004 $821,760 $821,760 0.8885 $730,123 0.7629 $626,917 0.6830 $561,2735 $821,760 $821,760 0.8626 $708,857 0.7130 $585,904 0.6209 $510,2486 $821,760 $821,760 0.8375 $688,211 0.6663 $547,573 0.5645 $463,8627 $821,760 $821,760 0.8131 $668,166 0.6227 $511,751 0.5132 $421,6938 $821,760 $821,760 0.7894 $648,705 0.5820 $478,272 0.4665 $383,3579 $821,760 $821,760 0.7664 $629,811 0.5439 $446,983 0.4241 $348,50610 $821,760 $821,760 0.7441 $611,467 0.5083 $417,741 0.3855 $316,82411 $821,760 $821,760 0.7224 $593,657 0.4751 $390,412 0.3505 $288,02212 $821,760 $821,760 0.7014 $576,366 0.4440 $364,871 0.3186 $261,83813 $821,760 $821,760 0.6810 $559,579 0.4150 $341,001 0.2897 $238,03514 $821,760 $821,760 0.6611 $543,280 0.3878 $318,693 0.2633 $216,39515 $821,760 $821,760 0.6419 $527,456 0.3624 $297,844 0.2394 $196,72316 $821,760 $821,760 0.6232 $512,094 0.3387 $278,359 0.2176 $178,83917 $821,760 $821,760 0.6050 $497,178 0.3166 $260,148 0.1978 $162,58118 $821,760 $821,760 0.5874 $482,697 0.2959 $243,129 0.1799 $147,80119 $821,760 $821,760 0.5703 $468,638 0.2765 $227,223 0.1635 $134,36420 $821,760 $821,760 0.5537 $454,989 0.2584 $212,358 0.1486 $122,14921 $821,760 $821,760 0.5375 $441,736 0.2415 $198,466 0.1351 $111,04522 $821,760 $821,760 0.5219 $428,870 0.2257 $185,482 0.1228 $100,95023 $821,760 $821,760 0.5067 $416,379 0.2109 $173,348 0.1117 $91,77324 $821,760 $821,760 0.4919 $404,251 0.1971 $162,007 0.1015 $83,43025 $821,760 $821,760 0.4776 $392,477 0.1842 $151,409 0.0923 $75,84526 $821,760 $821,760 0.4637 $381,046 0.1722 $141,503 0.0839 $68,95027 $821,760 $821,760 0.4502 $369,947 0.1609 $132,246 0.0763 $62,68228 $821,760 $821,760 0.4371 $359,172 0.1504 $123,595 0.0693 $56,98429 $821,760 $821,760 0.4243 $348,711 0.1406 $115,509 0.0630 $51,80330 $821,760 $821,760 0.4120 $338,554 0.1314 $107,952 0.0573 $47,094

$25,845,251

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $17,299,000 $11,390,000 $8,939,000

Ongoing Costs include annual O&M costs and periodic costs

Non-discounted cost:

PRESENT WORTH ANALYSIS

AppendixF_Alternatives Cost rev6.xls PW alt 2

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Item Notes Quantity Unit Unit Cost Total Cost

Direct ConstructionPilot testing a 1 each 265,000.00$ 265,000$ Upgrade to full scale treatment a 1 each 70,000.00$ 70,000$ Modify Pumpback sump and lime piping a 1 each 69,000.00$ 69,000$ Direct Construction Subtotal 404,000$

Indirect ConstructionMobilization/Demobilization 0%Engineering Design a 0% -$ Project/Construction Management a 0% -$ Indirect Construction Subtotal -$

TOTAL CAPITAL COSTS 404,000$

OPERATING AND MAINTENANCE (O&M) COSTS

Alternative Required O&MOperation and Maintenance a 1 year 160,000.00$ 160,000$ Alternative Required O&M 160,000$

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 year 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 year 40,000.00$ 40,000$ Water Treatment b 1 year 72,000.00$ 72,000$ Project Management see Alt 1 1 year 19,800.00$ 19,800$ Alternative 1 O&M 151,800$

TOTAL ANNUAL O&M COSTS 311,800$

TOTAL 30-YEAR COSTS (non-discounted) 10,565,300$ Present Worth Value (see following table at 7% discount) 5,080,000$

NotesUnless identified separately burden and profits are included in unit costs.

ab WTP functions as backup and treats CTP groundwater only; cost estimate from FCEMS, 2007 WTP cost per gallon = $0.006 at

12,000,000 gallons/year

Cost from In-Mine Remediation Proposal, Eagle Mine by Adrian Brown April 5, 2001.

TABLE F-3

DETAILED COST ESTIMATEAlternative 2B - In-mine Precipitation in Bleakhouse Mine Pool

CAPITAL COSTS

AppendixF_Alternatives Cost rev6.xls Alt 2B

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TABLE F-3 (cont.)

Alternative 2B - In-mine Precipitation in Bleakhouse Mine Pool

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $404,000 $807,300 $1,211,300 1.0000 $1,211,300 1.0000 $1,211,300 1.0000 $1,211,3001 $311,800 $311,800 0.9709 $302,718 0.9346 $291,402 0.9091 $283,4552 $311,800 $311,800 0.9426 $293,901 0.8734 $272,338 0.8264 $257,6863 $311,800 $311,800 0.9151 $285,341 0.8163 $254,522 0.7513 $234,2604 $311,800 $311,800 0.8885 $277,030 0.7629 $237,871 0.6830 $212,9645 $311,800 $311,800 0.8626 $268,961 0.7130 $222,309 0.6209 $193,6036 $311,800 $311,800 0.8375 $261,128 0.6663 $207,766 0.5645 $176,0037 $311,800 $311,800 0.8131 $253,522 0.6227 $194,173 0.5132 $160,0038 $311,800 $311,800 0.7894 $246,138 0.5820 $181,470 0.4665 $145,4579 $311,800 $311,800 0.7664 $238,969 0.5439 $169,599 0.4241 $132,23410 $311,800 $311,800 0.7441 $232,008 0.5083 $158,503 0.3855 $120,21211 $311,800 $311,800 0.7224 $225,251 0.4751 $148,134 0.3505 $109,28412 $311,800 $311,800 0.7014 $218,690 0.4440 $138,443 0.3186 $99,34913 $311,800 $311,800 0.6810 $212,321 0.4150 $129,386 0.2897 $90,31714 $311,800 $311,800 0.6611 $206,137 0.3878 $120,921 0.2633 $82,10715 $311,800 $311,800 0.6419 $200,133 0.3624 $113,011 0.2394 $74,64216 $311,800 $311,800 0.6232 $194,303 0.3387 $105,617 0.2176 $67,85717 $311,800 $311,800 0.6050 $188,644 0.3166 $98,708 0.1978 $61,68818 $311,800 $311,800 0.5874 $183,150 0.2959 $92,250 0.1799 $56,08019 $311,800 $311,800 0.5703 $177,815 0.2765 $86,215 0.1635 $50,98220 $311,800 $311,800 0.5537 $172,636 0.2584 $80,575 0.1486 $46,34721 $311,800 $311,800 0.5375 $167,608 0.2415 $75,304 0.1351 $42,13422 $311,800 $311,800 0.5219 $162,726 0.2257 $70,377 0.1228 $38,30323 $311,800 $311,800 0.5067 $157,986 0.2109 $65,773 0.1117 $34,82124 $311,800 $311,800 0.4919 $153,385 0.1971 $61,470 0.1015 $31,65625 $311,800 $311,800 0.4776 $148,917 0.1842 $57,449 0.0923 $28,77826 $311,800 $311,800 0.4637 $144,580 0.1722 $53,691 0.0839 $26,16227 $311,800 $311,800 0.4502 $140,369 0.1609 $50,178 0.0763 $23,78328 $311,800 $311,800 0.4371 $136,281 0.1504 $46,895 0.0693 $21,62129 $311,800 $311,800 0.4243 $132,311 0.1406 $43,827 0.0630 $19,65630 $311,800 $311,800 0.4120 $128,457 0.1314 $40,960 0.0573 $17,869

$10,565,300

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $7,323,000 $5,080,000 $4,151,000

Ongoing Costs include annual O&M costs and periodic costs

PRESENT WORTH ANALYSIS

Non-discounted cost:

AppendixF_Alternatives Cost rev6.xls PW alt 2

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Item Notes Quantity Unit Unit Cost Total Cost

Direct ConstructionTrench excavation a 4,444 cy 25.00$ 111,100$ Furnish and place IRM in excavated trench a 4,200 tons 84.00$ 352,800$ Haul excavated materials to CTP for disposal a 4,444 cy 4.50$ 19,998$ Screen half of above quantity and haul to landfill h 2,222 cy 5.00$ 11,110$ Load Backfill at WP-11 a 1,539 cy 9.50$ 14,621$ Haul Backfill b,c 1,539 cy 4.50$ 6,926$ Place Backfill b,d 1,539 cy 3.50$ 5,387$ Remove and dispose of existing tracks e 400 lf 15.00$ 6,000$ Replace railroad tracks e 400 lf 75.00$ 30,000$ Dewatering f 3 weeks 500.00$ 1,500$ Excavate temporary sediment retention pond b, g 1,000 cy 2.50$ 2,500$ Line sediment retention pond b 750 sy 3.00$ 2,250$ Remove temporary sediment retention pond h 1 lump 2,000.00$ 2,000$ Furnish and place 2-inch HDPE line to Tip Top mine h 1,000 ft 6.00$ 6,000$ Install two monitoring wells 50 ft 100.00$ 5,000$ Direct Construction Subtotal 577,191$

Indirect ConstructionMobilization/Demobilization 0% -$ Engineering Design 5% 28,860$ Project/Construction Management 5% 28,860$ Indirect Construction Subtotal 57,719$

TOTAL CAPITAL COSTS 634,910$

OPERATING AND MAINTENANCE (O&M) COSTS

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 year 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 year 40,000.00$ 40,000$ Water Treatment, less Tip Top flow i 1 year 607,310.00$ 607,310$ Project Management see Alt 1 1 year 105,300.00$ 105,300$ Alternative 1 O&M 772,610$

TOTAL ANNUAL O&M COSTS 772,610$

TOTAL 30-YEAR COSTS (non-discounted) 24,620,510$ Present Worth Value (see following table at 7% discount) 10,995,000$

NotesUnless identified separately burden and profits are included in unit costs.

abcdefghi

Assumes 1.5 mile round trip and 12 cy end dump; RT Rock CreekUses WP-11 gravel from Rock Creek as backfillCosts based on Illinois Department of Transportation FY 1998 Proposed Rail Improvement Program SupplementAssumes use of 6" trash pumpSize is adequate to store 2+ days dewatering @ 60gpmEstimateSee Alt 1 for base case; annual cost reduced by $34,800 or 5.8 million gallons/year at $0.006/gallon treated. the cost of operating the well at Rock Creek is included in the O&M of the existing system.

From memorandum Removal of Zinc from Seepage Through the Belden Railway Grade , Adrian Brown, P.E., December 12, 2012Cost from Means, 2005

TABLE F-4

DETAILED COST ESTIMATEAlternative 2C - IRM Reaction Wall in Belden

CAPITAL COSTS

AppendixF_Alternatives Cost rev6.xls Alt 2C

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TABLE F-4 (cont.)

Alternative 2C - IRM Reaction Wall in Belden

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $634,910 $772,610 $1,407,520 1.0000 $1,407,520 1.0000 $1,407,520 1.0000 $1,407,5201 $772,610 $772,610 0.9709 $750,107 0.9346 $722,065 0.9091 $702,3732 $772,610 $772,610 0.9426 $728,259 0.8734 $674,827 0.8264 $638,5213 $772,610 $772,610 0.9151 $707,048 0.8163 $630,680 0.7513 $580,4734 $772,610 $772,610 0.8885 $686,454 0.7629 $589,420 0.6830 $527,7035 $772,610 $772,610 0.8626 $666,460 0.7130 $550,860 0.6209 $479,7306 $772,610 $772,610 0.8375 $647,049 0.6663 $514,823 0.5645 $436,1187 $772,610 $772,610 0.8131 $628,203 0.6227 $481,143 0.5132 $396,4718 $772,610 $772,610 0.7894 $609,905 0.5820 $449,666 0.4665 $360,4289 $772,610 $772,610 0.7664 $592,141 0.5439 $420,249 0.4241 $327,66210 $772,610 $772,610 0.7441 $574,894 0.5083 $392,756 0.3855 $297,87511 $772,610 $772,610 0.7224 $558,150 0.4751 $367,061 0.3505 $270,79512 $772,610 $772,610 0.7014 $541,893 0.4440 $343,048 0.3186 $246,17713 $772,610 $772,610 0.6810 $526,110 0.4150 $320,606 0.2897 $223,79814 $772,610 $772,610 0.6611 $510,786 0.3878 $299,631 0.2633 $203,45215 $772,610 $772,610 0.6419 $495,909 0.3624 $280,029 0.2394 $184,95716 $772,610 $772,610 0.6232 $481,465 0.3387 $261,710 0.2176 $168,14217 $772,610 $772,610 0.6050 $467,442 0.3166 $244,589 0.1978 $152,85718 $772,610 $772,610 0.5874 $453,827 0.2959 $228,587 0.1799 $138,96119 $772,610 $772,610 0.5703 $440,609 0.2765 $213,633 0.1635 $126,32820 $772,610 $772,610 0.5537 $427,775 0.2584 $199,657 0.1486 $114,84421 $772,610 $772,610 0.5375 $415,316 0.2415 $186,595 0.1351 $104,40322 $772,610 $772,610 0.5219 $403,219 0.2257 $174,388 0.1228 $94,91223 $772,610 $772,610 0.5067 $391,475 0.2109 $162,980 0.1117 $86,28424 $772,610 $772,610 0.4919 $380,073 0.1971 $152,317 0.1015 $78,44025 $772,610 $772,610 0.4776 $369,003 0.1842 $142,353 0.0923 $71,30926 $772,610 $772,610 0.4637 $358,255 0.1722 $133,040 0.0839 $64,82627 $772,610 $772,610 0.4502 $347,821 0.1609 $124,336 0.0763 $58,93328 $772,610 $772,610 0.4371 $337,690 0.1504 $116,202 0.0693 $53,57529 $772,610 $772,610 0.4243 $327,854 0.1406 $108,600 0.0630 $48,70530 $772,610 $772,610 0.4120 $318,305 0.1314 $101,496 0.0573 $44,277

$24,585,820

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $16,551,000 $10,995,000 $8,691,000

Ongoing Costs include annual O&M costs and periodic costs

PRESENT WORTH ANALYSIS

Non-discounted cost:

AppendixF_Alternatives Cost rev6.xls PW alt 2

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Item Notes Quantity Unit Unit Cost Total Cost

ConstructionExcavate WP-8 and haul to CTP a 1 lump 1,850,000.00$ 1,850,000$ Demolish 350 feet of crib wall at WP-9 and WP-10 1 lump $20,000.00 20,000$ Dispose crib wall at CTP 520 cy $20.00 10,400$

Excavate and haul WP-9, WP-10 and remnants of WP-14 to CTP b 40,000 cy 12.00$ 480,000$ Cap and vegetate waste rock at CTP c 25 acre 26,000.00$ 650,000$ Lime application on waste rock pile footprints, WP-9, WP-10, and WP-14

1 acre 1,500.00$ 1,500$

Lime, soil amendments and seeding, WP-8 d 4 acre 8,000.00$ 32,000$ Direct Construction Subtotal 3,011,900$

Indirect ConstructionMobilization/Demobilization e -$ Engineering Design f 10% 301,190$ Project/Construction Management f 15% 451,785$ Indirect Construction Subtotal 752,975$

TOTAL CAPITAL COSTS 3,764,875$

OPERATING AND MAINTENANCE (O&M) COSTS

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 years 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 years 40,000.00$ 40,000$ Water Treatment see Alt 1 1 years 642,000.00$ 642,000$ Project Management see Alt 1 1 years 105,300.00$ 105,300$ Alternative 1 O&M 807,300$

TOTAL ANNUAL O&M COSTS 807,300$

TOTAL 30-YEAR COSTS (non-discounted) 28,791,175$ Present Worth Value (see following table at 7% discount) 14,590,000$

NotesUnless identified separately burden and profits are included in unit costs.

a

b Estimated volume of WP-9, WP-10 and WP-14 is 40,000 cy.c

d USEPA, 2007e Mobilization and demobilization costs are included in individual direct costs, as appropriatef Based off direct construction costs and mob/demob costs

Assumes repository covers 25 acres, is 5 feet thick with a vegetated cap composed of 24 inches of cap material borrowed from footprint of repository.

TABLE F-5

DETAILED COST ESTIMATE

Preliminary cost from ERM Remediation & Construction Management (April 2008) includes erosion control, transportation, final grading and confirmation sampling

Alternative 3A - Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite

CAPITAL COSTS

AppendixF_Alternatives Cost rev6.xls Alt 3A

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TABLE F-5 (cont.)

Alternative 3A - Excavate, Transport and Dispose of Accessible and Acid-Generating Waste Rock Onsite

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $3,764,875 $807,300 $4,572,175 1.0000 $4,572,175 1.0000 $4,572,175 1.0000 $4,572,1751 $807,300 $807,300 0.9709 $783,786 0.9346 $754,486 0.9091 $733,9092 $807,300 $807,300 0.9426 $760,958 0.8734 $705,127 0.8264 $667,190

3 $807,300 $807,300 0.9151 $738,794 0.8163 $658,997 0.7513 $606,5364 $807,300 $807,300 0.8885 $717,276 0.7629 $615,885 0.6830 $551,3975 $807,300 $807,300 0.8626 $696,384 0.7130 $575,594 0.6209 $501,2706 $807,300 $807,300 0.8375 $676,101 0.6663 $537,938 0.5645 $455,7007 $807,300 $807,300 0.8131 $656,409 0.6227 $502,746 0.5132 $414,2738 $807,300 $807,300 0.7894 $637,290 0.5820 $469,856 0.4665 $376,6119 $807,300 $807,300 0.7664 $618,728 0.5439 $439,118 0.4241 $342,37410 $807,300 $807,300 0.7441 $600,707 0.5083 $410,390 0.3855 $311,24911 $807,300 $807,300 0.7224 $583,211 0.4751 $383,542 0.3505 $282,95412 $807,300 $807,300 0.7014 $566,224 0.4440 $358,451 0.3186 $257,23113 $807,300 $807,300 0.6810 $549,732 0.4150 $335,001 0.2897 $233,84614 $807,300 $807,300 0.6611 $533,720 0.3878 $313,085 0.2633 $212,58715 $807,300 $807,300 0.6419 $518,175 0.3624 $292,603 0.2394 $193,26116 $807,300 $807,300 0.6232 $503,083 0.3387 $273,460 0.2176 $175,69217 $807,300 $807,300 0.6050 $488,430 0.3166 $255,571 0.1978 $159,72018 $807,300 $807,300 0.5874 $474,204 0.2959 $238,851 0.1799 $145,20019 $807,300 $807,300 0.5703 $460,392 0.2765 $223,225 0.1635 $132,00020 $807,300 $807,300 0.5537 $446,982 0.2584 $208,622 0.1486 $120,00021 $807,300 $807,300 0.5375 $433,964 0.2415 $194,974 0.1351 $109,09122 $807,300 $807,300 0.5219 $421,324 0.2257 $182,218 0.1228 $99,17423 $807,300 $807,300 0.5067 $409,052 0.2109 $170,297 0.1117 $90,15824 $807,300 $807,300 0.4919 $397,138 0.1971 $159,156 0.1015 $81,96225 $807,300 $807,300 0.4776 $385,571 0.1842 $148,744 0.0923 $74,51126 $807,300 $807,300 0.4637 $374,341 0.1722 $139,013 0.0839 $67,73727 $807,300 $807,300 0.4502 $363,438 0.1609 $129,919 0.0763 $61,57928 $807,300 $807,300 0.4371 $352,852 0.1504 $121,420 0.0693 $55,98129 $807,300 $807,300 0.4243 $342,575 0.1406 $113,476 0.0630 $50,89230 $807,300 $807,300 0.4120 $332,597 0.1314 $106,053 0.0573 $46,265

$28,791,175

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $20,396,000 $14,590,000 $12,183,000

Ongoing Costs include annual O&M costs and periodic costs

Non-discounted cost:

PRESENT WORTH ANALYSIS

AppendixF_Alternatives Cost rev6.xls PW alt 3

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Item Notes Quantity Unit Unit Cost Total Cost

ConstructionExcavate WP-8 and haul to CTP a 1 lump 1,850,000.00$ 1,850,000$ Demolish 350 feet of crib wall at WP-9 and WP-10 1 lump $20,000.00 20,000$ Dispose crib wall at CTP 520 cy $20.00 10,400$

Excavate and haul WP-9, WP-10, and WP-14 to CTP 40,000 cy 12.00$ 480,000$ Excavate and haul all other piles to CTP b 82,395 cy 12.00$ 988,740$ Lime application on waste rock pile footprints 10 acre 1,500.00$ 15,000$ Lime, soil amendments and seeding, WP-8 c 4 acre 8,000.00$ 32,000$ Cap and vegetate waste rock at CTP d 25 acre 26,000.00$ 650,000$ Direct Construction Subtotal 4,046,140$

Indirect ConstructionMobilization/Demobilization e -$ Engineering Design f 10% 404,614$ Project/Construction Management f 15% 606,921$ Indirect Construction Subtotal 1,011,535$

TOTAL CAPITAL COSTS 5,057,675$

OPERATING AND MAINTENANCE (O&M) COSTS

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 years 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 years 40,000.00$ 40,000$ Water Treatment see Alt 1 1 years 642,000.00$ 642,000$ Project Management see Alt 1 1 years 105,300.00$ 105,300$ Alternative 1 O&M 807,300$

TOTAL ANNUAL O&M COSTS 807,300$

TOTAL 30-YEAR COSTS (non-discounted) 30,083,975$ Present Worth Value (see following table at 7% discount) 15,717,000$

NotesUnless identified separately burden and profits are included in unit costs.

a

bc USEPA 2007d

e Mobilization and demobilization costs are included in individual direct costs, as appropriatef Based off direct construction costs and mob/demob costs

Preliminary cost from ERM Remediation & Construction Management (April 2008) includes erosion control, transportation, final grading and confirmation sampling

Assumes repository covers 25 acres, is 10 feet thick with a vegetated cap composed of 24 inches of cap material borrowed from footprint of repository.

TABLE F-6

DETAILED COST ESTIMATEAlternative 3B - Excavate, Transport and Dispose of All Waste Rock Onsite

CAPITAL COSTS

Volume from Table 10, less WP-8, WP-9, WP-10, WP-13, and WP-14.

AppendixF_Alternatives Cost rev6.xls Alt 3B

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TABLE F-6 (cont.)

Alternative 3B - Excavate, Transport and Dispose of All Waste Rock Onsite

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $2,528,838 $807,300 $3,336,138 1.0000 $3,336,138 1.0000 $3,336,138 1.0000 $3,336,1381 $2,528,838 $807,300 $3,336,138 0.9709 $3,238,968 0.9346 $3,117,886 0.9091 $3,032,8522 $807,300 $807,300 0.9426 $760,958 0.8734 $705,127 0.8264 $667,1903 $807,300 $807,300 0.9151 $738,794 0.8163 $658,997 0.7513 $606,5364 $807,300 $807,300 0.8885 $717,276 0.7629 $615,885 0.6830 $551,3975 $807,300 $807,300 0.8626 $696,384 0.7130 $575,594 0.6209 $501,2706 $807,300 $807,300 0.8375 $676,101 0.6663 $537,938 0.5645 $455,7007 $807,300 $807,300 0.8131 $656,409 0.6227 $502,746 0.5132 $414,2738 $807,300 $807,300 0.7894 $637,290 0.5820 $469,856 0.4665 $376,6119 $807,300 $807,300 0.7664 $618,728 0.5439 $439,118 0.4241 $342,37410 $807,300 $807,300 0.7441 $600,707 0.5083 $410,390 0.3855 $311,24911 $807,300 $807,300 0.7224 $583,211 0.4751 $383,542 0.3505 $282,95412 $807,300 $807,300 0.7014 $566,224 0.4440 $358,451 0.3186 $257,23113 $807,300 $807,300 0.6810 $549,732 0.4150 $335,001 0.2897 $233,84614 $807,300 $807,300 0.6611 $533,720 0.3878 $313,085 0.2633 $212,58715 $807,300 $807,300 0.6419 $518,175 0.3624 $292,603 0.2394 $193,26116 $807,300 $807,300 0.6232 $503,083 0.3387 $273,460 0.2176 $175,69217 $807,300 $807,300 0.6050 $488,430 0.3166 $255,571 0.1978 $159,72018 $807,300 $807,300 0.5874 $474,204 0.2959 $238,851 0.1799 $145,20019 $807,300 $807,300 0.5703 $460,392 0.2765 $223,225 0.1635 $132,00020 $807,300 $807,300 0.5537 $446,982 0.2584 $208,622 0.1486 $120,00021 $807,300 $807,300 0.5375 $433,964 0.2415 $194,974 0.1351 $109,09122 $807,300 $807,300 0.5219 $421,324 0.2257 $182,218 0.1228 $99,17423 $807,300 $807,300 0.5067 $409,052 0.2109 $170,297 0.1117 $90,15824 $807,300 $807,300 0.4919 $397,138 0.1971 $159,156 0.1015 $81,96225 $807,300 $807,300 0.4776 $385,571 0.1842 $148,744 0.0923 $74,51126 $807,300 $807,300 0.4637 $374,341 0.1722 $139,013 0.0839 $67,73727 $807,300 $807,300 0.4502 $363,438 0.1609 $129,919 0.0763 $61,57928 $807,300 $807,300 0.4371 $352,852 0.1504 $121,420 0.0693 $55,98129 $807,300 $807,300 0.4243 $342,575 0.1406 $113,476 0.0630 $50,89230 $807,300 $807,300 0.4120 $332,597 0.1314 $106,053 0.0573 $46,265

$30,083,975

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $21,615,000 $15,717,000 $13,245,000

Ongoing Costs include annual O&M costs and periodic costs

PRESENT WORTH ANALYSIS

Non-discounted cost:

AppendixF_Alternatives Cost rev6.xls PW alt 3

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Item Notes Quantity Unit Unit Cost Total Cost

ConstructionExcavate WP-8 and haul to offsite repository a 1 lump 1,850,000.00$ 1,850,000$ Demolish 350 feet of crib wall at WP-9 and WP-10 1 lump $20,000.00 20,000$ Dispose crib wall at non-hazardous solid waste landfill 520 cy $20.00 10,400$

Excavate WP-9, WP-10, and WP-14 and load 40,000 cy 6.50$ 260,000$ Excavate all other piles and load b 82,395 cy 6.50$ 535,568$ Haul to offsite repository 4 hr RT c 7,418 hr 125.68$ 932,294$ Lime application on waste rock pile footprints 10 acre 1,500.00$ 15,000$ Lime, soil amendments and seeding, WP-8 d 4 acre 8,000.00$ 32,000$ Cap and vegetate waste rock repository e 25 acre 26,000.00$ 650,000$ Direct Construction Subtotal 4,305,262$

Indirect ConstructionMobilization/Demobilization f -$ Engineering Design g 10% 430,526$ Project/Construction Management g 15% 645,789$ Indirect Construction Subtotal 1,076,315$

TOTAL CAPITAL COSTS 5,381,577$

OPERATING AND MAINTENANCE (O&M) COSTS

Alternative Required O&MO & M of repository 1 year 3,500.00$ 3,500$ Alternative Required O&M 3,500$

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 years 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 years 40,000.00$ 40,000$ Water Treatment see Alt 1 1 years 642,000.00$ 642,000$ Project Management see Alt 1 1 years 105,300.00$ 105,300$ Alternative 1 O&M 807,300$

TOTAL ANNUAL O&M COSTS 810,800$

TOTAL 30-YEAR COSTS (non-discounted) 30,512,877$ Present Worth Value (see following table at 7% discount) 16,074,000$

NotesUnless identified separately burden and profits are included in unit costs.

a

bc 16.5 cy dump truck, highway from Means 2005 (02225 3138) d USEPA 2007e

f Mobilization and demobilization costs are included in individual direct costs, as appropriateg Based off direct construction costs and mob/demob costs

Preliminary cost from ERM Remediation & Construction Management (April 2008) includes erosion control, transportation, final grading and confirmation sampling

Assumes repository covers 25 acres, is 10 feet thick with a vegetated cap composed of 24 inches of cap material borrowed from footprint of repository.

TABLE F-7

DETAILED COST ESTIMATEAlternative 3C - Excavate, Transport and Dispose of All Waste Rock Offsite

CAPITAL COSTS

Volume from Table 10, less WP-8, WP-9, WP-10, WP-13, and WP-14; transport cost on 200 mile RT.

AppendixF_Alternatives Cost rev6.xls Alt 3C

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TABLE F-7 (cont.)

Alternative 3C - Excavate, Transport and Dispose of All Waste Rock Offsite

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $2,690,789 $807,300 $3,498,089 1.0000 $3,498,089 1.0000 $3,498,089 1.0000 $3,498,0891 $2,690,789 $810,800 $3,501,589 0.9709 $3,399,601 0.9346 $3,272,513 0.9091 $3,183,2622 $810,800 $810,800 0.9426 $764,257 0.8734 $708,184 0.8264 $670,0833 $810,800 $810,800 0.9151 $741,997 0.8163 $661,854 0.7513 $609,1664 $810,800 $810,800 0.8885 $720,385 0.7629 $618,555 0.6830 $553,7875 $810,800 $810,800 0.8626 $699,403 0.7130 $578,089 0.6209 $503,4436 $810,800 $810,800 0.8375 $679,032 0.6663 $540,270 0.5645 $457,6757 $810,800 $810,800 0.8131 $659,255 0.6227 $504,925 0.5132 $416,0698 $810,800 $810,800 0.7894 $640,053 0.5820 $471,893 0.4665 $378,2449 $810,800 $810,800 0.7664 $621,411 0.5439 $441,021 0.4241 $343,85810 $810,800 $810,800 0.7441 $603,311 0.5083 $412,170 0.3855 $312,59811 $810,800 $810,800 0.7224 $585,739 0.4751 $385,205 0.3505 $284,18012 $810,800 $810,800 0.7014 $568,679 0.4440 $360,005 0.3186 $258,34613 $810,800 $810,800 0.6810 $552,115 0.4150 $336,453 0.2897 $234,86014 $810,800 $810,800 0.6611 $536,034 0.3878 $314,442 0.2633 $213,50915 $810,800 $810,800 0.6419 $520,422 0.3624 $293,871 0.2394 $194,09916 $810,800 $810,800 0.6232 $505,264 0.3387 $274,646 0.2176 $176,45417 $810,800 $810,800 0.6050 $490,547 0.3166 $256,679 0.1978 $160,41218 $810,800 $810,800 0.5874 $476,260 0.2959 $239,886 0.1799 $145,83019 $810,800 $810,800 0.5703 $462,388 0.2765 $224,193 0.1635 $132,57220 $810,800 $810,800 0.5537 $448,920 0.2584 $209,526 0.1486 $120,52021 $810,800 $810,800 0.5375 $435,845 0.2415 $195,819 0.1351 $109,56422 $810,800 $810,800 0.5219 $423,150 0.2257 $183,008 0.1228 $99,60423 $810,800 $810,800 0.5067 $410,826 0.2109 $171,036 0.1117 $90,54924 $810,800 $810,800 0.4919 $398,860 0.1971 $159,846 0.1015 $82,31725 $810,800 $810,800 0.4776 $387,243 0.1842 $149,389 0.0923 $74,83426 $810,800 $810,800 0.4637 $375,964 0.1722 $139,616 0.0839 $68,03127 $810,800 $810,800 0.4502 $365,013 0.1609 $130,482 0.0763 $61,84628 $810,800 $810,800 0.4371 $354,382 0.1504 $121,946 0.0693 $56,22429 $810,800 $810,800 0.4243 $344,060 0.1406 $113,968 0.0630 $51,11230 $810,800 $810,800 0.4120 $334,039 0.1314 $106,512 0.0573 $46,466

$30,512,877

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $22,003,000 $16,074,000 $13,588,000

Ongoing Costs include annual O&M costs and periodic costs

PRESENT WORTH ANALYSIS

Non-discounted cost:

AppendixF_Alternatives Cost rev6.xls PW alt 3

Page 236: FOCUSED FEASIBILITY STUDY EAGLE MINE SITE MINTURN

Item Notes Quantity Unit Unit Cost Total Cost

ConstructionOTP/Rex Flats interceptor trench/water treatment system, installed

a 1 lump 563,700.00$ 563,700$

Direct Construction Subtotal 563,700$

Indirect ConstructionMobilization/Demobilization b 6% 33,822$ Engineering Design c 10% 59,752$ Project/Construction Management c 15% 89,628$ Indirect Construction Subtotal 183,203$

TOTAL CAPITAL COSTS 746,903$

OPERATING AND MAINTENANCE (O&M) COSTS

Alternative Required O&MOTP/Rex Flats interceptor trench/water treatment system a 1 years 116,375.00$ 116,375$ Additional Water Treatment Costs, WTP d 1 years 12,960.00$ 12,960$ Alternative Required O&M 129,335$

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 years 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 years 40,000.00$ 40,000$ Water Treatment see Alt 1 1 years 642,000.00$ 642,000$ Project Management see Alt 1 1 years 105,300.00$ 105,300$ Alternative 1 O&M 807,300$

TOTAL ANNUAL O&M COSTS 936,635$

TOTAL 30-YEAR COSTS (non-discounted) 29,653,253$ Present Worth Value (see following table at 7% discount) 13,177,000$

NotesUnless identified separately burden and profits are included in unit costs.

ab Mobilization and demobilization costs are included in individual direct costs, as appropriatec Based off direct construction costs and mob/demob costsd Cost estimate from FCEMS, 2007 WTP cost per gallon = $0.006 at 25 gpm for 60 days

TABLE F-8

DETAILED COST ESTIMATEAlternative 4A - Groundwater Collection and Treatment, OTP/Rex Flats

CAPITAL COSTS

From ERM 2007 Table 14; treatment capacity 250 gpm for 180 days per year.

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TABLE F-8 (cont.)

Alternative 4A - Groundwater Collection and Treatment, OTP/Rex Flats

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $746,903 $807,300 $1,554,203 1.0000 $1,554,203 1.0000 $1,554,203 1.0000 $1,554,2031 $936,635 $936,635 0.9709 $909,354 0.9346 $875,360 0.9091 $851,4862 $936,635 $936,635 0.9426 $882,868 0.8734 $818,093 0.8264 $774,079

3 $936,635 $936,635 0.9151 $857,154 0.8163 $764,573 0.7513 $703,7084 $936,635 $936,635 0.8885 $832,188 0.7629 $714,554 0.6830 $639,7345 $936,635 $936,635 0.8626 $807,950 0.7130 $667,808 0.6209 $581,5776 $936,635 $936,635 0.8375 $784,417 0.6663 $624,119 0.5645 $528,7067 $936,635 $936,635 0.8131 $761,570 0.6227 $583,289 0.5132 $480,6428 $936,635 $936,635 0.7894 $739,388 0.5820 $545,130 0.4665 $436,9479 $936,635 $936,635 0.7664 $717,853 0.5439 $509,467 0.4241 $397,22510 $936,635 $936,635 0.7441 $696,944 0.5083 $476,138 0.3855 $361,11311 $936,635 $936,635 0.7224 $676,645 0.4751 $444,989 0.3505 $328,28512 $936,635 $936,635 0.7014 $656,937 0.4440 $415,877 0.3186 $298,44113 $936,635 $936,635 0.6810 $637,803 0.4150 $388,670 0.2897 $271,31014 $936,635 $936,635 0.6611 $619,226 0.3878 $363,243 0.2633 $246,64515 $936,635 $936,635 0.6419 $601,190 0.3624 $339,480 0.2394 $224,22316 $936,635 $936,635 0.6232 $583,680 0.3387 $317,271 0.2176 $203,83917 $936,635 $936,635 0.6050 $566,680 0.3166 $296,515 0.1978 $185,30818 $936,635 $936,635 0.5874 $550,174 0.2959 $277,116 0.1799 $168,46219 $936,635 $936,635 0.5703 $534,150 0.2765 $258,987 0.1635 $153,14720 $936,635 $936,635 0.5537 $518,592 0.2584 $242,044 0.1486 $139,22521 $936,635 $936,635 0.5375 $503,487 0.2415 $226,210 0.1351 $126,56822 $936,635 $936,635 0.5219 $488,823 0.2257 $211,411 0.1228 $115,06223 $936,635 $936,635 0.5067 $474,585 0.2109 $197,580 0.1117 $104,60224 $936,635 $936,635 0.4919 $460,762 0.1971 $184,654 0.1015 $95,09225 $936,635 $936,635 0.4776 $447,342 0.1842 $172,574 0.0923 $86,44826 $936,635 $936,635 0.4637 $434,313 0.1722 $161,284 0.0839 $78,58927 $936,635 $936,635 0.4502 $421,663 0.1609 $150,733 0.0763 $71,44428 $936,635 $936,635 0.4371 $409,381 0.1504 $140,872 0.0693 $64,94929 $936,635 $936,635 0.4243 $397,458 0.1406 $131,656 0.0630 $59,04530 $936,635 $936,635 0.4120 $385,881 0.1314 $123,043 0.0573 $53,677

$29,653,253

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $19,913,000 $13,177,000 $10,384,000

Ongoing Costs include annual O&M costs and periodic costs

Non-discounted cost:

PRESENT WORTH ANALYSIS

AppendixF_Alternatives Cost rev6.xls PW alt 4

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Item Notes Quantity Unit Unit Cost Total Cost

Direct ConstructionTrench excavation a 1,222 cy 25.00$ 30,550$ Haul excavated gravel to Temp Cell b 1,222 cy 4.50$ 5,499$ Furnish and place IRM in excavated trench c 580 tons 84.00$ 48,720$ Furnish and place clean backfill from stockpile b 822 cy 4.50$ 3,699$ Dewatering d 2 week 500.00$ 1,000$ Excavate temporary sediment retention pond e 1,000 cy 2.50$ 2,500$ Line sediment retention pond 750 sy 3.00$ 2,250$ Remove temporary sediment retention pond e 1 lump 2,000.00$ 2,000$ Direct Construction Subtotal 96,218$

Indirect ConstructionMobilization/Demobilization 0% -$ Engineering Design 5% 4,811$ Project/Construction Management 15% 14,433$ Indirect Construction Subtotal 19,244$

TOTAL CAPITAL COSTS 115,462$

OPERATING AND MAINTENANCE (O&M) COSTS

O&M of Existing Remedial SystemsGroundwater and surface water sampling see Alt 1 1 year 20,000.00$ 20,000$ Operation and Maintenance see Alt 1 1 year 40,000.00$ 40,000$ Water Treatment see Alt 1 1 year 642,000.00$ 642,000$ Project Management see Alt 1 1 year 105,300.00$ 105,300$ Alternative 1 O&M 807,300$

TOTAL ANNUAL O&M COSTS 807,300$

TOTAL 30-YEAR COSTS (non-discounted) 25,141,762$ Present Worth Value (see following table at 7% discount) 15,883,000$

NotesUnless identified separately burden and profits are included in unit costs.

a 200 ft long x 15 ft deep by 11 ft wideb Cost from Means 2005cde Size is adequate to store 2+ days dewatering @ 60gpm

Cost from Removal of Zinc from Seepage through the Belden Railway Grade, Adrian Brown, P. E., December 12, 2012.

TABLE F-9

DETAILED COST ESTIMATEAlternative 4B - IRM Reaction Wall at OTP/Rex Flats

CAPITAL COSTS

Assumes use of 6" trash pump

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TABLE F-9 (cont.)

Alternative 4B - IRM Reaction Wall at OTP/Rex Flats

Capital Ongoing Total Annual Rate of Return = 3% Rate of Return = 7% Rate of Return = 10%Year Costs Costs Expenditure Discount Present Discount Present Discount Present

Factor Worth Factor Worth Factor Worth

0 $5,057,675 $807,300 $5,864,975 1.0000 $5,864,975 1.0000 $5,864,975 1.0000 $5,864,9751 $807,300 $807,300 0.9709 $783,786 0.9346 $754,486 0.9091 $733,9092 $807,300 $807,300 0.9426 $760,958 0.8734 $705,127 0.8264 $667,1903 $807,300 $807,300 0.9151 $738,794 0.8163 $658,997 0.7513 $606,5364 $807,300 $807,300 0.8885 $717,276 0.7629 $615,885 0.6830 $551,3975 $807,300 $807,300 0.8626 $696,384 0.7130 $575,594 0.6209 $501,2706 $807,300 $807,300 0.8375 $676,101 0.6663 $537,938 0.5645 $455,7007 $807,300 $807,300 0.8131 $656,409 0.6227 $502,746 0.5132 $414,2738 $807,300 $807,300 0.7894 $637,290 0.5820 $469,856 0.4665 $376,6119 $807,300 $807,300 0.7664 $618,728 0.5439 $439,118 0.4241 $342,37410 $807,300 $807,300 0.7441 $600,707 0.5083 $410,390 0.3855 $311,24911 $807,300 $807,300 0.7224 $583,211 0.4751 $383,542 0.3505 $282,95412 $807,300 $807,300 0.7014 $566,224 0.4440 $358,451 0.3186 $257,23113 $807,300 $807,300 0.6810 $549,732 0.4150 $335,001 0.2897 $233,84614 $807,300 $807,300 0.6611 $533,720 0.3878 $313,085 0.2633 $212,58715 $807,300 $807,300 0.6419 $518,175 0.3624 $292,603 0.2394 $193,26116 $807,300 $807,300 0.6232 $503,083 0.3387 $273,460 0.2176 $175,69217 $807,300 $807,300 0.6050 $488,430 0.3166 $255,571 0.1978 $159,72018 $807,300 $807,300 0.5874 $474,204 0.2959 $238,851 0.1799 $145,20019 $807,300 $807,300 0.5703 $460,392 0.2765 $223,225 0.1635 $132,00020 $807,300 $807,300 0.5537 $446,982 0.2584 $208,622 0.1486 $120,00021 $807,300 $807,300 0.5375 $433,964 0.2415 $194,974 0.1351 $109,09122 $807,300 $807,300 0.5219 $421,324 0.2257 $182,218 0.1228 $99,17423 $807,300 $807,300 0.5067 $409,052 0.2109 $170,297 0.1117 $90,15824 $807,300 $807,300 0.4919 $397,138 0.1971 $159,156 0.1015 $81,96225 $807,300 $807,300 0.4776 $385,571 0.1842 $148,744 0.0923 $74,51126 $807,300 $807,300 0.4637 $374,341 0.1722 $139,013 0.0839 $67,73727 $807,300 $807,300 0.4502 $363,438 0.1609 $129,919 0.0763 $61,57928 $807,300 $807,300 0.4371 $352,852 0.1504 $121,420 0.0693 $55,98129 $807,300 $807,300 0.4243 $342,575 0.1406 $113,476 0.0630 $50,89230 $807,300 $807,300 0.4120 $332,597 0.1314 $106,053 0.0573 $46,265

$30,083,975

@ 3% @ 7% @ 10%TOTAL PRESENT WORTH $21,688,000 $15,883,000 $13,475,000

Ongoing Costs include annual O&M costs and periodic costs

PRESENT WORTH ANALYSIS

Non-discounted cost:

AppendixF_Alternatives Cost rev6.xls PW alt 4