MFG. Inc. A TETRA TECH COMPANY

49OO Pearl East Circle Suite 300W Boulder. CO 8O3O1-6118 303/447-1823 Fax: 303/447-1836 consulting scientists and engineers April 12, 2005 MFC Project No. 010179

SDMS Document ID Mr. Stan Christensen Remedial Program Manager U.S. EPA Region VIE 999 18th Street, Suite 500 Denver, CO 80202-2405 RE: FINAL REMEDIAL DESIGN REPORT FOR THE ARKANSAS VALLEY (AV) SMELTER /COLORADO ZINC-LEAD (CZL) MILL SITE, CALIFORNIA GULCH SUPERFUND SITE, LEADVILLE, COLORADO

Dear Stan:

On behalf of ASARCO Incorporated (Asarco), please find enclosed three copies of the Final Remedial Design Report (RDR) for the Arkansas Valley (AV) Smelter/Colorado Zinc-Lead (CZL) Mill site. These two areas (the AV/CZL site) comprise a portion of Operable Unit 5 (OU5) at the California Gulch Superfund Site located in Leadville, Colorado.

This RDR presents the design of the final remedy for the AV/CZL site selected by the U.S. Environmental Protection Agency (EPA) in a Record of Decision (ROD) signed on September 29, 2000. This document is intended to fulfill the requirements of both the Remedial Design Report and the Remedial Action Work Plan as generally described in the Asarco Work Area Management Plan, Appendix B to the Consent Decree dated August 26, 1994.

The final RDR addresses all comments on the draft RDR by EPA dated August 24, 2004 and the Colorado Department of Public Health and Environment (CDPHE) dated August 19, 2004. EPA accepted Asarco's response to comment and approved the remedial design on September 22, 2004. Therefore, this document represents the complete remedial design as approved by EPA.

As noted previously, the remedial action will be implemented in a phased approach over a period of several years. Consequently, the engineering drawings and technical specifications for completion of each phase of the remedial action may be issued separately for the purpose of bidding and contracting the remedial construction activities. However, because the exact scope of each phase has not been determined at this time, this report includes only one set of specifications that addresses all components of the remedial action.

A borrow source for soil cover material has not yet been selected, although several potential sources have been identified. Thus, this RDR does not include information pertaining to a borrow area investigation (Appendix B) or an engineering drawing of the borrow area (Drawing 534451C-103). The source of borrow material is anticipated to be selected and investigated during the first phase of the remedial construction work, since the activities anticipated for the initial phase of construction work will likely not Mr. Stan Christensen April 12, 2005 Page 2 require a significant quantity of borrow source material, if any. Results of the borrow source investigation and engineering drawings of the borrow area will be prepared and submitted prior to implementation of the second phase of the remedial construction activities. Selection of a borrow source of soil cover material may involve addressing access issues with the Leadville Corporation.

If you have any questions, please do not hesitate to call me at 303-447-1823, or Bob Litle with Asarco at 303- 296-5115.

Respectfully,

&~ Daryl L. Longwell,'. Senior Civil Engineer/Project Manager

Enclosures: cc: Mr. Bob Litle, Asarco (2 copies) Mr. Doug Jamison, CDPHE (3 copies) Lake County Commissioners (1 copy) Mayor of Leadville (1 copy) Mr. Jim Tiffany, Leadville Corporation (1 copy) MFC Proj. File 010179 (1 copy) MFG - Leadville (1 copy)

J:\BLD01\5344\5344-50\COMM\FinaI AV-CZL RDR Report Trans ltr.doc FINAL REMEDIAL DESIGN REPORT

ARKANSAS VALLEY SMELTER AND COLORADO ZINC-LEAD MILL SITE OPERABLE UNIT 5 CALIFORNIA GULCH SUPERFUND SITE

April 2005

Preparedfor:

ASARCO Incorporated 495 East 51st Avenue Denver, CO 80216-2098

Prepared by:

MFC, INC. 4900 Pearl East Circle, Suite 300W Boulder, CO 80301 (303)447-1823 FAX: (303)447-1836

MFG Project No. 5344.51 TABLE OF CONTENTS

LIST OF TABLES Hi LIST OF FIGURES iii LIST OF DRAWINGS iii LIST OF APPENDICES iv LIST OF ACRONYMS AND ABBREVIATIONS v 1.0 INTRODUCTION 1 1.1 Site Description and History 1 1.2 Project History 4 1.3 Remedy Overview 5 2.0 Supporting Technical Considerations 8 2.1 Delineation of the Extent and Volume of Flue Dust at the AV Smelter Site 8 2.2 Supporting Considerations for Repository Design 9 2.2.1 Required Repository, Capacity 9 2.2.2 Repository Location 10 2.2.3 Repository Liner Evaluation and Selection 10 2.2.4 Settlement Considerations 11 2.2.5 Repository Side Slope Stability Considerations 11 2.3 Cover Soil Borrow Area Investigation 11 2.4 Consolidation/Covering of Non-residential Area Soils and Tailing at the AV Smelter and CZL Mill Sites 12 2.4.1 Material Quantities 12 2.4.2 Revegetation and Erosion 12 2.5 Site Run-on/Run-off Control and Stormwater Management 13 3.0 REMEDIAL DESIGN 14 3.1 Demolition of Structures - AV Smelter Site 14 3.2 Demolition of Structures-CZL Mill Site 15 3.3 Flue Dust Excavation 15 3.3.1 Flue Dust Removal Areas and Excavation Depths 15 3.3.2 Removal Confirmation Sampling 16 3.4 Flue Dust Repository 16 3.4.1 Footprint, Excavation and Repository Floor 17 3.4.2 Preparation, Consolidation and Compaction of Flue Dust Materials 17 3.4.3 Repository Liner and Cover Design 18 3.5 Consolidation of Non-Residential Area Soils and Tailing at the AV Smelter Site 19 3.5.1 Removal of Non-Residential Area Soils and Tailing from Areas Outside the Final Soil Cover 19 3.5.2 Confirmation Sampling 19

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL Dtjign\Fin>l\AVRemedial Design Rcpon Firal.doc i April 2005 3.6 Consolidation of Non-Residential Area Soils and Tailing at the CZL Mill Site 20 3.6.1 Removal of Non-Residential Area Soils/Tailing from Areas Outside the Final Soil Cover 20 3.6.2 Confirmation Sampling 20 3.7 Soil Cover Over Consolidated Non-Residential Area Soils and Tailing at the AV Smelter and CZL Mill Sites 20 3.8 Borrow Area Development and Reclamation 21 4.0 CONSTRUCTION CONSIDERATIONS 22 4.1 Field Management and Oversight 22 4.2 General Construction Sequencing and Schedule Requirements 23 4.2.1 AV Smelter Site 23 4.2.2 CZL Mill Site 24 4.3 Material Excavation and Soil Cover Activities 24 4.3.1 Borrow Area 24 4.3.2 AV Smelter Site 25 4.3.3 CZL Mill 27 4.4 Repository Construction 29 4.4.1 Repository Excavation 30 4.4.2 Liner System Installation 30 4.4.3 Leachate Collection Piping & Flue Dust Material Placement 31 4.4.4 Repository Top Liner and Cover System 32 4.5 Revegetation 32 4.6 Dust Control 33 4.7 Stormwater Control 34 4.8 Temporary Work Stoppages 35 4.9 Decontamination Procedures 35 5.0 OPERATIONS AND MAINTENANCE 36 5.1 Cover System Inspection and Maintenance 36 5.2 Surface Drainage Controls Inspection and Maintenance 37 5.3 Institutional Controls 37 5.4 Groundwater Monitoring 38 5.5 Reporting 38 6.0 REFERENCES CITED 39

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL Design\Final\AVRemedial Design Report Firul.doc 11 April 2005 LIST OF TABLES

Table Title

5-1 Groundwater Sampling Laboratory Analytical Parameters

LIST OF FIGURES

Figure Title

1-1 California Gulch Site Location Map 1-2 OU5 AV/CZL Site Location Map 1-3 AV/CZL Site Cultural Features 5-1 Proposed Groundwater Monitoring Well Locations

LIST OF DRAWINGS Drawing Title

534451G-001 Title Sheet and Location Map 534451G-002 General Notes, Symbols and Abbreviations 534451C-101 Existing Site Plan 534451C-102 Demolition Plan - AV Smelter 534451C-103 Borrow Area Plan and Sections [To be developed during construction] 534451C-104 Excavation Plan - AV Smelter 534451C-105 Excavation & Regrading Plan - CZL Mill 534451C-106 Regrading Plan - AV Smelter 534451C-107 Flue Dust Repository Plan, Sections and Details 534451C-301 Regrading Plan Sections and Details - AV Smelter 534451C-302 Regrading Plan Sections and Details - CZL Mill 534451C-303 Run-on/Run-off Control Channel Profiles AV Smelter 534451C-304 Run-on/Run-off Control Channel Profiles and Details CZL Mill 534451C-501 Run-On/Run-Off Control Sections and Miscellaneous Details

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZL D»ign\Fit»l\AVRemcdiBl Design Repon Fiiul.doc 111 April 2005 LIST OF APPENDICES

Appendix Title

A Investigation to Support Remedial Design B Borrow Area Investigation, Laboratory Analyses, and Quantity Estimates [To be developed during construction] C Repository Design Supporting Analyses C.I Repository Geomembrane Liner Analysis C.2 Repository Excavation Slope Stability Analysis D Technical Specifications E Construction Quality Assurance Plan F Fugitive Emissions Dust Control Plan G Stormwater Management Plan H Health and Safety Plan 1 Stormwater Analyses for the Soil Covers 1.1 Infiltration Analysis 1.2 Erosion Calculations 1.3 Supporting Calculations for Run-on/Run-off Control and Storm Water Management

ASARCO Incorporated MFC, Inc. JABLDOl\5344\S344-50VAV_CZLD«ign\Final\AVRemedillDesignReportFitwl.doc W April 2005 LIST OF ACRONYMS AND ABBREVIATIONS

APEN Air Pollution Emission Notice ARAR Applicable or Relevant and Appropriate Requirements Asarco ASARCO Incorporated AV Arkansas Valley BHHRA Baseline Human Health Risk Assessment CDPHE Colorado Department of Public Health and Environment CERCLA Comprehensive Environmental Response, Compensation, and Liability Act cy Cubic yards CZL Colorado Zinc-Lead EE/CA Engineering Evaluation/Cost Analysis EPA U.S. Environmental Protection Agency FPS Field Project Supervisor ft Feet ft2 Square feet gpm Gallon per Minute LCCHP Lake County Community Health Program mg/Kg Milligram per kilogram NRHP National Registry of Historic Places O&M Operation and Maintenance OU5 Operable Unit 5 oz Ounce RAOs Remedial Action Objectives RDR Remedial Design Report RI Remedial Investigation ROD Record of Decision SFS , Screening Feasibility Study SHPO State Historic Preservation Officer IDS Total Dissolved Solids TSP Total suspended particulate

ASARCO Incorporated MFC, Inc. J:\BLD01\i344\5344-SO\AV_CZLDcsign\FinBlVAVRemediBlDesign Rcpon Fiiul.doc April 2005 1.0 INTRODUCTION

This Remedial Design Report (RDR), prepared by ASARCO Incorporated (Asarco), presents the design of remedial actions at the Arkansas Valley (AV) Smelter/Colorado Zinc-Lead (CZL) Mill site. These two areas (the AV/CZL site) comprise a portion of Operable Unit 5 (OU5) at the California Gulch Superfund Site located in Leadville, Colorado. This RDR presents the technical requirements and related design analyses for the implementation of the final remedy for the AV/CZL site selected by the U.S. Environmental Protection Agency (EPA) in a Record of Decision (ROD) signed on September 29, 2000. This document is intended to fulfill the requirements of both the Remedial Design Report and Remedial Action Work Plan as generally described in the Asarco Work Area Management Plan, Appendix B to the Consent Decree (USDC, 1994) entered into on August 26, 1994 by Asarco, the United States, the State of Colorado, and other potentially responsible parties at the California Gulch Superfund Site.

1.1 Site Description and History

The California Gulch Superfund Site is located in Lake County, Colorado, in the upper Arkansas River basin, approximately 100 miles southwest of Denver. The Superfund Site encompasses approximately 16.5 square miles and includes the City of Leadville and portions of unincorporated Lake County (Figure 1-1). The Superfund Site is located in the highly mineralized Colorado Mineral Belt area of the Rocky Mountains. Mining in the area began in 1860, when placer gold was discovered in California Gulch. Subsequent mining, mineral processing, and smelting activities produced gold, silver, lead, and zinc in the Leadville area.

The location of the AV/CZL site is shown on Figure 1-2. The AV Smelter operated from 1879 to 1961 processing lead ores and reprocessing slag to produce lead, silver and other metals. The CZL Mill operated from 1926 to 1938 processing ores to produce zinc, lead, gold, silver and some copper concentrates. The majority of smelter and mill structures have been demolished although some buildings and foundations are still present at the site today.

The AV/CZL site is owned by the Leadville Corporation and is located within the Industrial/Mining and Business/Highway zoning districts established by Lake County. No industrial or mining operations are currently performed at the site. The properties immediately surrounding the site are also zoned for industrial/mining uses, and the property adjacent to the southern boundary is currently used for industrial

ASARCO Incorporated MFC, Inc. J-.\BLD01\5344\5344-50\AV_CZL Design\Final\AVRemedi«l Design Report Final doc 1 April 2005 operations. The closest residential area is Stringtown, located approximately 500 feet south of the CZL Mill site, within unincorporated Lake County. There is also one occupied residence at the site. Per the requirements of the ROD, Asarco will offer the resident services and cleanup consistent with the procedures, requirements, and standards of the Lake County Community Health Program (LCCHP) during the remedial design for OU5. If and when future remediation occurs for the current resident, Asarco will conduct or fund the response activities consistent with the procedures and requirements of LCCHP. As shown on Figure 1-3, the AV/CZL site portion of OU5 shares contiguous boundaries with portions of OU3 (Slag Piles) and OU8 (Lower California Gulch Tailings Areas). The remedy described in this document includes the CZL Mill site (OU5), but does not include the CZL Tailing Impoundment and the remaining portion of Fluvial Tailing Site 2 within California Gulch's 500-year floodplain, which are included in OU8. Tailing from the CZL Tailing Impoundment was removed in accordance with the EPA-approved non-time-critical removal action described in the Engineering Evaluation/Cost Analysis (EE/CA) for the CZL Tailing Area (SMI/TMI, 1995). Tailing was also removed in 1998 from a portion of Fluvial Tailing Site 2 within the 500-year floodplain, which defines OU8. The AV Smelter portion of OU5 includes the area where demolition debris and residual mine waste and smelter materials are present, but excludes the AV slag pile which is a part of OU3.

A cultural resource survey of the AV Smelter site was conducted for Asarco by Foothill Engineering Consultants, Inc. (FEC) to evaluate the site for potential historic significance. The survey was conducted in August and September 1995 (FEC, 1996a,b). The Colorado State Historic Preservation Officer (SHPO) assigned a permanent Smithsonian number of 5LK892 to the AV Smelter site. FEC reported that the site was in generally poor condition. Several smaller buildings and structures remained standing, while many large features had collapsed and/or been removed. Significant features are shown on Figure 1-3 and are briefly described below.

• Feature 1 - Includes the blast furnace building and the change house floor/ore house location; the power and blower house; the boiler house; and a safe/vault. • Feature 2 - The bag house system. • Feature 3 - Includes the mixing and roasting area and associated features. • Feature 4 - The ore bins. • Feature 5 - Stack and flue remains and associated features. • Feature 6 - Includes a heating plant, coal bin, and four railroad sidings. • Feature 7 - A concrete arch used to carry the roaster flue across the railroad tracks, identified or known as the Dewey Arch.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZL Dcsign\Fin«l\AVRemedial Dtlign Report Finul.doc 2 April 2005 • Feature 8 - The base of a large roasting plant stack. • Feature 9 - A concrete loading platform. • Feature 10 - A large trash scatter consisting of industrial artifacts, flue fragments and other miscellaneous items. • Feature 15 - A small, tall building identified as the Matte Hoist House on the Sanbom Map. \

FEC concluded that the site has been adequately mapped, photographed and recorded (FEC, 1996a,b). Based on the survey results, the AV Smelter (site 5LK892) has been subsequently recommended by FEC as being eligible for the National Registry of Historic Places (NRHP) as a contributing feature to the Leadville Historic Mining District under NRHP criteria. FEC indicated that the site retains sufficient integrity of physical remains to convey most of the details of the technologies utilized, and sufficient integrity overall to convey the importance and magnitude of the site. The SHPO concurred that the AV Smelter is eligible for listing on the NRHP and contributing to the Leadville Historic Mining District, and therefore consideration of additional mitigation or investigative activities was performed as part of EPA's remedy selection process. As discussed in Section 3.1, all structures within the remediation area at the AV Smelter site will be demolished except the easternmost of the two ore bins (feature #4a on Figure 1- 3), the base of two smelter smoke stacks (feature #8 and the stack portion of feature #6), and the concrete arch (feature #7). A Mitigation Plan has been prepared to address the designated historical structures that will be adversely affected by the remediation (FEC, 2001).

A cultural resource survey of the CZL Mill site was also conducted for Asarco by FEC in August and September 1995 (FEC, 1996a,b), and permanent Smithsonian number of 5LK845 has been assigned to the CZL Mill site. FEC described the mill by level and identified and described other features at the site. Site features are shown on Figure 1-3. The concrete mill foundation is mostly intact, but some sections are disintegrating. The wooden mill superstructure has been removed. Level 1 consists of a cement foundation, slab concrete floors, wooden beam supports and four cement-walled bins. Level 2 consists of a cement foundation and flooring, long concrete "lanes" divided with concrete walls, and numerous concrete floorings. Water tanks may have been located in this area. Level 3 consists of a concrete foundation, floors and walls, and wooden beam supports. Level 4 consists of concrete floors where a wood-frame concentrator crucible was located. Level 5 consists of concrete floors/walls, metal pipe and a loading chute. The foundations of the other associated buildings (Feature A - machine shop, Feature B - assay laboratory, and Feature C - transformer house) are extant. The wooden transformer house has collapsed. Numerous crucibles are located within the assay laboratory.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZLDesign\FinaI\AVTltmediBlDesignRtponFinal.doc 3 ' April 2005 FEC indicated that the CZL Mill and associated Features A through C (Figure 1-3) had sufficient physical integrity to convey some technological and/or associative value they may have had, and that there was potential for subsurface archeological remains in some portions of the site. Thus, the CZL Mill and associated Features A through C were recommended by FEC as being eligible for the NRHP and contributing to the Leadville Historic Mining District (FEC, 1996a,b). FEC concluded that the site has been adequately mapped, photographed and recorded (FEC, 1996a,b). The SHPO concurred that the CZL Mill site is individually eligible for listing on the NRHP and contributing to the Leadville Historic Mining District and therefore consideration of additional mitigation or investigative activities was performed as part of EPA's remedy selection process. Implementation of the selected remedy will not impact existing structures at the CZL Mill site.

1.2 Project History

Site characterization has been performed by a series of investigations to assess the general conditions at the AV/CZL site and to evaluate the physical and chemical stability of the materials of concern and the potential for release and environmental transport of metals. The principal findings are documented in the Smelter Site Reconnaissance Report (WCC, 1992), Smelter Remedial Investigation (RJ) Report (Walsh, 1993a), Soils Investigation Data Report (CDM, 1993a), Lead Slag RJ (MK, 1992), Tailing Disposal Area RJ (WCC, 1994), two metals speciation studies of mining-related materials (CDM, 1994b; Walsh, 1993b) and Focused Feasibility Study (FFS; MFG, 2000). Other California Gulch Superfund Site information relevant to the AV/CZL site is presented in the Surface Water RJ (Colder, 1996a), Hydrogeologic RJ (Colder, 1996b), Baseline Human Health Risk Assessment (BHHRA) (EPA, 1996), and the Ecological Risk Assessment for the Terrestrial Ecosystem (EPA, 1997).

The EPA conducted a Screening Feasibility Study (SFS) (EPA, 1993) to initiate the overall Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) FS process at the California Gulch Superfund Site and to develop and screen preliminary remedial action alternatives applicable to site sources. The SFS presents qualitative remedial action objectives (RAOs) developed for each source material and also identifies a preliminary list of potential Applicable or Relevant and Appropriate Requirements (ARARs) that may apply to a site and its remedial activities. The information provided in the SFS was used as the starting point for the development of RAOs and ARARs, and the development and evaluation of remedial alternatives for the AV/CZL site. A Draft Smelter FS was initially prepared and submitted by Colder and Associates, Inc. (Colder, 1996c). This version of the FS

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZL DtsignXFinilUVRcmcditl Design Report Final.doc 4 April 2005 addressed all OU5 sites including the AV/CZL site. Pursuant to comments from the EPA and State which, in part, clarified the RAOs specified in the SFS for OU5 and the scope of the OU5 FS, the Draft Smelter FS was subsequently revised and resubmitted by WESTEC in January 1997 (WESTEC, 1997b). Based on the comments received on the Draft Smelter FS, Asarco proposed additional site characterization and WESTEC prepared a work plan for a Supplemental Remedial Investigation (RI) (WESTEC, 1997a). The Supplemental RI was performed in November 1997. At the same time, EPA and Asarco agreed that two FFS Reports would be submitted for OU5, one for the AV/CZL site and one for the remaining portion of OU5 (the "EGWA" sites). This division was made because site characterization activities indicated that the EGWA sites contained a more limited suite of smelter-related materials, dominated primarily by slag, compared to the AV/CZL site. EPA and State comments on the revised Smelter FS and the results of the Smelter Supplemental RI were incorporated into the FFS (MFG, 2000). The FFS provided a detailed analysis of the five retained alternatives from the SFS as applied to tailing, flue dust, and non-residential area soils. A Proposed Plan describing EPA's preferred alternative was issued on July 27, 2000. After public comment, EPA's ROD was signed on September 29, 2000.

1.3 Remedy Overview

EPA's ROD sets out the requirements and scope of the final remedial action for the AV/CZL site. The RAOs are as follows:

Tailing

• Control airborne transport of tailing particles; • Control erosion of tailing into local water courses; • Control leaching and migration of metals from tailing into surface water; and • Control leaching and migration of metals from tailing into groundwater.

Flue Dust

Control airborne transport of flue dust particles; Control erosion of flue dust and deposition into local water courses; Control release and migration of metals from flue dust to surface water; Control leaching and migration of metals from flue dust to groundwater; and

ASARCO Incorporated MFG, Inc. I-.VBLDOl\3344M344-50\AV_CZL Design\Fintl\AVRtmcdi«l Design Report Final doc 5 April 2005 • Control contamination exposure to animals and aquatic life.

Non-Residential Area Soils

• Control airborne transport of contaminated materials; • Control erosion of contaminated materials and deposition into local water courses; • Control leaching and migration of metals from soils into surface water; • Control leaching and migration of metals from soils into groundwater; and • Control contamination exposure to animals and aquatic life.

It is also the objective of the remedial design and remedial action programs to minimize the potential for releases or exposure to hazardous substances during clean-up activities, through the implementation of engineering controls and environmental monitoring. All remedial actions will be conducted in accordance with ARARs, such that the remedy and the implementation thereof, is protective of human health and the environment.

The final remedy for the AV/CZL site, selected in the ROD includes: excavation of flue dust and relocation to a single-lined, fully encapsulated repository, and consolidation of tailing and non-residential area soils and covering with 18 inches of revegetated clean soil. The principal components of the remedy are as follows:

• All smelter structures within the remediation area of the AV Smelter site except the easternmost of the two ore bins, the base of two smelter smoke stacks and the concrete (Dewey) arch will be demolished to grade. Any salvageable demolition debris, such as metal, will be relocated to a designated location for recycling area. Prior to demolition, each of the structures will be evaluated by a certified asbestos inspector to identify any asbestos containing materials, which will be removed and disposed in accordance with State and Federal requirements. At the CZL Mill site, non-residential area soils and other mine waste will be removed from the mill foundations, which will remain in place. • The flue dust will be excavated and relocated to a lined repository. The repository will be lined with a fully-encapsulating 60-mil thick geomembrane liner overlain by 6 to 8 . feet of non-residential area soils fill and the 18-inch thick vegetated soil cover. In addition, three groundwater wells (one upgradient and two downgradient of the repository) will be installed and monitored on an annual basis. • The tailing and non-residential area soils located at the AV Smelter site will be consolidated near the former blast furnace and baghouse and covered with an 18-inch thick soil cover. At the CZL Mill site, the non-residential area soils will be consolidated on top of the tailing at the base of the slope and the tailing and non-residential area soils will be covered with an 18-inch thick soil layer. Any tailing potentially in contact with

ASARCO Incorporated MFC, Inc. J:\BLDOI\53M\5344-50\AV_CZL Design\Final\AVRemedi»l Design Repon Fiiul doc 6 April 2005 groundwater (possible in the southern portion at the CZL Mill Site, adjacent to California Gulch) will be excavated and consolidated up hill, to the north. The overall goal of the consolidation will be to reduce average arsenic and lead concentrations in surface soils outside the covered area to below the risk-based action levels established for a commercial/industrial worker exposure scenario in the human health risk assessment. The purpose of consolidating the materials is to reduce the size of the covers to a single area at the main smelter area and a single area at the CZL Mill area. Limited site grading will be conducted to promote positive surface water drainage, stabilize any excavated slopes and facilitate installation of the soil covers. Diversion ditches will be constructed upgradient of the covered areas to prevent stormwater from running onto the covered areas. Excavated areas and the soil cover will be revegetated, with soil amendments as necessary, to reduce the potential for soil erosion and further reduce infiltration through the soil cover. Dust monitoring and engineering controls will be implemented during activities, which could potentially disturb the tailing, non-residential area soils or flue dust. Conventional dust control measures including water sprays, placement of clean gravel over haul roads and surfactant sprays could be used, as required based on air quality monitoring results. Institutional Controls such as deed notices or deed restrictions to provide notification that a barrier is in place, and to restrict land use to protect the integrity of the remedy will be implemented in the cover areas. Lake County and/or City of Leadville zoning ordinances will be modified to create a zoning "overlay district" to provide a screening process to identify properties where special precautions or requirements may be necessary. Restrictions and requirements from the overlay district will be placed on land use activities outside the cover areas to prevent residential use. Land use and plans/proposals for future land use at each site will be monitored and evaluated by EPA as part of the five-year review process. An Operation and Maintenance (O&M) program will be implemented, including inspection and maintenance of the cover and surface water controls.

ASARCO Incorporated MFG. Inc. J:\BLD01\5344\5344-50\AV_CZL Design\Final\AVRcmedi>l Design Report Final.doc 7 April 2005 2.0 SUPPORTING TECHNICAL CONSIDERATIONS

This section provides a summary of technical considerations and analyses performed to support the remedial design.

2.1 Delineation of the Extent and Volume of Flue Dust at the AV Smelter Site

A field investigation to identify the nature and extent of flue dust to be relocated to the repository was performed in March 2001. Details of the implementation and findings of the investigation are provided in Appendix A.

As demonstrated by this investigation, flue dust is chemically distinct from other residual smelter materials at the site. The principal distinguishing characteristic is that arsenic concentrations are higher in flue dust than found in other materials. Also, arsenic concentrations are relatively higher compared to lead concentrations in flue dust than typically found in other smelter residual materials.

A key finding of the investigation is that large quantities of high-arsenic flue dust are not present at the site. A single sample of flue dust was collected during the site characterization effort and found to contain 149,000 mg/Kg arsenic. The highest arsenic concentration measured during the investigation to support remedial design was 62,000 mg/Kg, in the area immediately adjacent to the flue dust material identified previously.

Based on the results of the investigation the following findings have been developed to support remedial design:

Flue dust is present mixed with demolition debris and other materials in the footprint of the former baghouse and in the area immediately adjacent to the northwest. While concentrations of arsenic in the southern portion of the debris pile were relatively low, this area will be included in the flue dust excavations to provide a conservative approach. Flue dust may be present in some of the piles of fine-grained materials in the blast furnace and in the adjacent area next to the baghouse. These piles will be classified as flue dust for purposes of the remediation. Flue dust is present within the footprint of the flues in the southern portion of the former roasting plant area (south of the Dewey Arch) and in an immediately adjacent area next to the eastern ore bin.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZL Design\Final\AVRemedi«l Design Repon Final.doc 8 April 2005 Flue dust is present in an open area in the southern portion of the former roasting plant area. Samples were not collected in areas to the south and east of this location and therefore the investigation was not sufficient to delineate the lateral extent of flue dust in this area. Arsenic concentrations in flue dust in the blast furnace area ranged up to 149,000 mg/Kg. Arsenic concentrations in the former roasting plant area were in the range of 20,000 to 40,000 mg/Kg. Based on these levels, an arsenic concentration to confirm that flue dust has been removed was established at 10,000 mg/Kg.

The in-place volumes of the flue dust materials were estimated from the investigation data using AutoCAD Land Development Desktop computer software. Based on a value of 10,000 mg/kg arsenic as the threshold for flue dust and non-flue dust materials, it is estimated that approximately 4,500 cubic yards of materials are present. This estimate includes a conservative assumption of the extent of flue dust south and east of the southern former roasting plant area where the limits of the flue dust were not fully delineated.

2.2 Supporting Considerations for Repository Design

Factors considered in the support of the repository design included the required repository capacity, the repository location, the liner material, settlement, and side slope stability. Each of these factors is discussed in the following sections.

2.2.1 Required Repository Capacity

As, discussed in Section 2.1, it is estimated that approximately 4,500 cubic yards of materials (in-place) will be excavated from flue dust removal areas. The volume of flue dust in this material will be less than the total volume, because structural materials (such as brick, rebar, concrete, wood, etc.) will be separated out prior to relocation to the repository. However, the overall volume of material excavated is likely to increase, because sampling will be performed at the base of excavations and in areas adjacent to excavations in a portion of the roasting plant area to confirm that the flue dust materials have been adequately removed. If removal confirmation levels are not achieved, additional excavation will be required. Based on this, a contingency of 100% was added to the estimated in-place volume for the purposes of repository design. The required repository capacity is therefore estimated at 9,000 cubic yards (4,500 cubic yards in place, plus 4,500 cubic yards contingency).

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-5(AAV_CZL Design\Final\AVRemedial Design Report Finil.doc 9 April 2005 2.2.2 Repository Location

Various repository locations were considered at the AV Smelter site. Overall, it was determined that a location within the final soil cover area would be the most appropriate for two principal reasons: (1) this would be consistent with one of the goals of the remedy; to reduce the area of the site where smelter materials requiring management are present; and (2) the soil cover would provide additional protection for the repository. The location of the repository was selected to be in the open area to the north west of the baghouse footprint (see Drawing C-106). This area is relatively free of smelter structures and foundations and is close to the baghouse flue dust removal areas, reducing the distance that materials will have to be transported. The maximum ground water elevation recorded in the vicinity of this area (based on monitoring wells MW- 8, 11, and 12; MFG, 2000) is approximately 80 feet below grade, and therefore, groundwater contact with the bottom liner is not a concern.

2.2.3 Repository Liner Evaluation and Selection

The repository liner system will completely encapsulate the flue dust materials excavated from the AV Smelter site. The primary objectives of this encapsulation are to: (1) prevent direct contact with the flue dust materials; (2) minimize surface water infiltration into the flue dust; and (3) minimize the potential for leachate generation and subsequent migration from the repository into the underlying alluvium and groundwater.

EPA's ROD requires that the repository be lined with a 60-mil thick geomembrane liner. A 60-mil HDPE liner has been selected. This selection was made based upon compatibility with the flue dust materials, strength and water tightness requirements. A geomembrane liner that has a high puncture and tensile strength and good compatibility with the flue dust materials is required to provide long-term, essentially water-tight containment. Infiltration analysis (Appendix I.I) indicates that infiltration through the top repository liner would be 0.000001 gpm (approximately 0.00022% of current conditions). The flue dust materials do not pose a compatibility problem with most geomembrane type liners. As discussed in Appendix C.I, another key design parameter for the geomembrane liner design for the repository system is puncture strength. To provide cushion and protect the geomembrane liner from sharp angular rocks and debris fragments, an 12 oz, non-woven geotextile will be placed on both sides of the geomembrane liner for additional puncture resistance protection. This type of system has been used successfully in recent remedial construction at the Former Murray Smelter Site (MFG, 200Ib).

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZL Design\Final\AVRemedial Design Report Final.doc 10 April 2005 2.2.4 Settlement Considerations

The subgrade in the area of the repository is classified as dense alluvium and consists of sandy gravels and cobbles. The base of the repository and repository side slopes will be founded on undisturbed alluvium. These granular material types typically do not exhibit settlement due to consolidation, which occurs when water is expelled from the voids of the soil under loading such as that which is induced from overburden stresses. The repository will be excavated in an area that will not induce loads on the subgrade significantly greater than those that currently exist and therefore settlement/consolidation of the subgrade materials will be nominal.

2.2.5 Repository Side Slope Stability Considerations

The stability of the repository side slopes will be closely monitored during excavation and final subgrade preparation activities that will take place prior to the placement of the liner system. Granular soil material types that will be encountered in the repository excavation typically have excellent stability characteristics and can effectively withstand cut slopes greater than 3(h):l(v). Based upon the stability evaluation presented in Appendix C.2, a safety factor of 1.7 is obtained against slope failure. It should be noted that the repository excavation will be exposed for a very short period (2 weeks maximum) before the liner is installed and materials are placed into the repository. To have an open excavation exposed for such a short period of time further reduces the potential for slope failure to occur.

2.3 Cover Soil Borrow Area Investigation

A suitable borrow area will be developed to provide cover soil for remedial action construction. A Borrow Area Investigation Work Plan was submitted to EPA and CDPHE on February 22, 2001. Comments received from CDPHE included a request that Asarco evaluate the feasibility of using borrow material from existing borrow sites such as the site north of the "Hecla/Malta Gulch Impoundment" or the Oregon Gulch Impoundment borrow site. This evaluation is pending. A borrow area will be selected and investigated at a later date.

ASARCO Incorporated MFC, Inc. J:\BLDO l\5344\5344-SO\AV_CZLDesign\Final\AVRtmed:al Design Report Final.doc 1 1 April 2005 2.4 Consolidation/Covering of Non-residential Area Soils and Tailing at the AV Smelter and CZL Mill Sites

2.4.1 Material Quantities

Estimates of the material quantities to be generated from the non-residential area soils/tailing removals were prepared using AutoCAD Land Development Desktop computer software and the estimated depths of excavation from data generated during the RL These areas and depths were then used to establish the respective grading plans which balance the cut and fill quantities. It is estimated that 61,400 cubic yards of non-residential area soils and tailing will be excavated at the AV smelter site. After consolidation in the central portion of the AV Smelter site, it is estimated that these materials will be covered by a total of 22,400 cubic yards of soil (18 inch soil cover over 9.3 acres). At the CZL Mill site, it is estimated that 8,200 cubic yards of non-residential area soils/tailing will be excavated. After consolidation, these materials will be covered by a total of 4,300 cubic yards of soil (18 inch soil cover over 1.8 acres). If additional non-residential area soils/tailing are identified for excavation by post-removal confirmation sampling, the grading plans will be adjusted accordingly, while keeping the soil cover extent the same.

2.4.2 Revegetation and Erosion

Revegetation of the soil cover surface has been designed to provide a sustainable protective cover to allow permanent protection from erosion while also providing a mechanism for evapotranspiration of water from the growth medium. Plant species that will be used to revegetate disturbed areas have been selected to conform with site conditions, climate, and soils. The selected species include: Standard crested wheatgrass (Agropyron desertorum), Streambank wheatgrass (Agropyron riparium), Smooth brome (Bromus inermis), Hard fescue (Festuca longifolid), Timothy (Phleum pratense), Little bluestem (Schizachyrium scoparium), Cereal rye (Secale cereale), Cicer milkvetch (Astragalus deer), White dutch clover (Trifolium repens), and Regreen (Triticum aestivum x Elytrigia elonga). Seeding application rates for these plant species, application requirements, and fertilizer recommendations are provided in the Technical Specifications (Appendix D.)

The closure has been designed to meet the criterion for overall long-term erosion control of 2 tons per acre per year (U.S. EPA, 1985). Supporting calculations are provided in Appendix 1.2.

ASARCO Incorporated MFC, Inc. J:\BLD01\3344\5344-50\AV_CZLDesign\rinil\AVRtmedialDnignRfpoitFiMl.doc 12 April 2005 2.5 Site Run-on/Run-off Control and Stormwater Management

Run-on and run-off control structures were designed consistent with the minimum requirements of the relevant and appropriate sections of the Colorado Hazardous Waste Regulations and the Colorado Solid Waste Disposal Sites and Facilities Act. All such features are required to meet the minimum criterion of controlling the 100-year, 24-hour storm event.

The Rational Method was used to design the run-on/run-off control features. This method is based on defining the maximum rate of flow by determining the contributing drainage basin area and the average rate of rainfall intensity for a period equal to the time of concentration. Generally, the time of concentration is the time required for the precipitation to travel the distance from the most distant point in the watershed, or drainage area, to the hydraulic outlet. Rainfall depth-frequency-duration maps for Colorado were used to calculate an average rainfall intensity curve for the specified storm event. Based on the intensity, drainage basin area, and run-off coefficients, peak flow rates were calculated and the hydraulic structures sized accordingly. Appendix 1.3 provides the supporting calculations and appropriate design criteria for the run-on and run-off control features for the remedy.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZL DeslgnVFinalUVRemeditl Design Report Final.doc 13 April 2005 3.0 REMEDIAL DESIGN

This section presents the design and corresponding specifications for remediation of the AV/CZL site. Included are the designs of: (1) demolition of structures at the site to allow access for remedial action construction; (2) excavation of flue dust at the AV Smelter site; (3) construction of the repository to contain the excavated flue dust; (4) excavation and consolidation of non-residential area soils and tailing at the AV Smelter site and at the CZL Mill site; (5) placement of soil cover over the consolidated non- residential area soils, tailing and demolition debris; and (6) borrow area development and reclamation.

3.1 Demolition of Structures - AV Smelter Site

All structures to be demolished to grade at the AV Smelter site are discussed below and are identified on Drawing C-102.

Prior to initiation of demolition work at the AV Smelter site, an asbestos inspection and removal will be performed. The inspection will be performed in accordance with the requirements of Colorado Air Quality Control Commission Regulation No, 8 Part B. Materials identified as containing asbestos will be collected and disposed offsite in accordance with the requirements of Regulation No. 8 Part B.

Demolition debris other than metal scrap to be salvaged will be reduced to a maximum size of 10 feet in any one dimension and placed in the area to be covered by the soil shown on Drawing C-106. Scrap metal is to be consolidated and stockpiled for recycling. Details of structure demolition are as follows:

The concrete loading ramp/wall located approximately 100 ft west of the railroad car and loading ramp in the west central area of the site will be demolished to grade. The railroad car located in the west central portion of the site will be removed. The concrete loading ramp/wall will be demolished to grade. The thaw house and miscellaneous adjacent foundations which are located in the central portion of the site, excluding the eastern ore bins will be demolished to grade. Materials comprising the smokestack debris areas located north of the thaw house will be placed in the soil cover area. Materials comprising the scrap areas south of the thaw house will be segregated with the salvageable scrap metal hauled to the consolidated scrap metal area for recycling. All other materials will be placed within the soil cover area. The bag house manifold located in the central portion of the site will be demolished.

ASARCO Incorporated MFG, Inc. J:\BLD01\5344\5344-50\AV_CZL Dcsign\Final\AVRem«lial Design Repon Final.doc 14 April 2005 The western ore bin located north and west of the bag house will be demolished. The brick wall east of the ore house will be demolished. The concrete loading platform located north of the ore house and brick wall will be demolished. The above-ground storage tanks east of the blast furnace building will be relocated to outside the soil cover area.

3.2 Demolition of Structures - CZL Mill Site

The only features to be removed at the CZL Mill site are five abandoned overhead electrical power poles surrounding the transformer house and one abandoned overhead power pole in the middle of the tailing area. The poles will be placed within the CZL soil cover area identified on Drawing C-105. It is not anticipated that other demolition will be required on the CZL site. In the event other demolition is performed during construction activities, these materials will be placed in the CZL cover soil area prior to covering. Any salvageable scrap metal will be segregated and consolidated with the salvageable metals at the AV Smelter site.

3.3 Flue Dust Excavation

This section presents the design for flue dust removal at the AV Smelter site. In general, the flue dust will be excavated to design depths and limits and soil samples will be collected from the base of the excavation and analyzed for arsenic to confirm that the material has been removed.

3.3.1 Flue Dust Removal Areas and Excavation Depths

The flue dust removal depths and limits are shown in Drawing C-104. In addition, piles of fine-grained materials present in the blast furnace building and adjacent flue area will be removed for relocation to the repository. The total in-place volume of material to be removed is estimated at approximately 4,500 cubic yards. A portion of the excavated material will be structural debris (bricks, concrete, wood, etc.) greater than 2 inches in diameter, which will be separated and relocated to the area to be covered by the soil cover.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\J344-50\AV_CZL DtsigrAFinaKAVRemedisI Dwign Report Firnl.doc 1 5 April 2005 3.3.2 Removal Confirmation Sampling

After the excavation depths and limits have been achieved, soil sampling and analysis will be performed to confirm that flue dust has been removed. The removal areas will be divided into decision units for confirmation testing. Each decision unit will encompass a maximum area of approximately 10,000 ft2 (i.e. equivalent to an area of 100 feet by 100 feet). However, smaller units may be used in some areas to accommodate the actual excavation geometry. Initial decision units are shown on Figures 4-1 and 4-2 of the Quality Assurance Plan (Appendix E). As shown, it is anticipated that a total of nine decision units will be established for flue dust removal. This includes two decision units adjacent to excavation areas in the roasting plant area, where sampling to support remedial design did not adequately evaluate the potential of flue dust.

Composite soil samples will be collected from the base of the initial excavation in each decision unit and analyzed for arsenic and lead. Each decision unit will be divided into four quadrants of approximately equal size and a single 0 to 6 inch depth soil sample will be collected from each quadrant. The four grab samples will be composited to generate one sample per decision unit. The measured arsenic concentration will be compared to a flue dust removal confirmation level of 10,000 mg/Kg. If the arsenic concentration is less than or equal to 10,000 mg/Kg, no further excavation will be required. If the arsenic concentration is greater than 10,000 mg/Kg, an additional one-foot of soil will be excavated from the decision unit. Following any additional excavation, a second 4-by-l composite sample will be collected from the decision unit and analyzed for arsenic and lead. The procedure will be repeated as necessary until the 10,000 mg/Kg arsenic removal confirmation level has been achieved for the decision unit. Details of flue dust removal confirmation sampling are provided in Appendix E (Quality Assurance Plan, Section 4.2.1).

3.4 Flue Dust Repository

This section presents the design and specifications for the repository earthworks and geosynthetics. The primary objective of the repository is to provide containment of the flue dust. Based upon the results of the sampling investigation to support remedial design, discussed in Section 2.1, it is estimated that approximately 9,000 cubic yards (4,500 cubic yards in-place volume, plus 4,500 cubic yards contingency) of storage capacity is needed to contain the flue dust materials excavated from the AV Smelter site (see Section 2.2.1).

ASARCO Incorporated MFC, Inc. J:\BLDOI\53-M\5344-50\AV_CZL Design\Final\AVRemedi«l Design Report Final.doc 16 April 2005 3.4.1 Footprint, Excavation and Repository Floor

The repository footprint is shown on Drawings C-106 and C-107 and typical sections and details are illustrated on Drawing C-107. The repository footprint will be rectangular in shape, with ground surface dimensions of 230 feet in length by 115 feet in width. The side slopes have been designed at 3(H):1(V) to allow for consistent excavation, ease of liner installation and ease of flue dust material placement. The excavation cuts are designed to a maximum depth of 10 feet below the existing ground surface on the north end to 4 feet below the existing ground surface on the south end. The repository floor will be 190 feet in length by 75 feet in width. The floor will slope at approximately 2% to a common low area or sump in the southeast corner to allow for the collection and removal of precipitation that may collect prior to the placement of flue dust materials.

The subgrade is required to provide stability for the repository and an adequate base for the geomembrane liner system. The bottom of the repository excavation will be proof rolled using a heavy static roller. Any soft areas that reflect unusually large displacement (greater than 2 inches) will require removal and replacement with suitable compacted fill (e.g., silty sand). If the subgrade consists of granular fill, slag, concrete fragments, wood or other deleterious material, these materials will be removed to a depth of at least 6 inches and replaced with compacted silty sand material. The entire repository subgrade including side slopes and base will require approval by the geomembrane liner fabricator/installer prior to installation of the liner in that particular area.

3.4.2 Preparation, Consolidation and Compaction of Flue Dust Materials

In addition to containing fine grained flue dust, materials excavated from areas identified as containing flue dust, will also have structural debris such as bricks, concrete, wood, rebar and other miscellaneous materials. These materials will be separated from the flue dust prior to relocation to the repository. Removal of structural materials will be achieved by passing the excavated material through a 2-inch screen. Materials rejected by the screen will be relocated to the area to be covered.

Flue dust materials will be placed in the repository in uniform compacted lifts to provide stability during placement of subsequent lifts and minimize long-term consolidation. The flue dust materials will be placed in horizontal lifts approximately 8 to 12-inches in loose thickness and compacted to 92% of the

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZLDesign\Fin.r\AVRemcdialDMignReportFinal.doc 17 April 2005 maximum dry density as determined by the Standard Proctor Density Test (ASTM D698). Moisture content of the flue dust materials will be maintained between optimum and 3 percent dry of optimum.

3.4.3 Repository Liner and Cover Design

The repository liner system for the base, sides and top will consist of a 60-mil HDPE geomembrane. The bottom liner will be installed on top of prepared alluvial subgrade, geotextile or sandy material to provide suitable base conditions. A 12 ounce per square yard (oz/sy) non-woven geotextile will be placed between granular soils and the geomembrane liner to achieve required puncture resistance. Acceptable subgrade conditions will be certified in writing by the geomembrane liner manufacturer/installer prior to the liner installation. The bottom liner will extend up the 3(H):1(V) side slopes and be anchored in a trench along the slope crest. The anchor trench for the bottom liner will be located as shown on Drawing C-107 where each side will consist of a minimum 4-foot-wide runout and a 2-foot-deep anchor trench. The top liner will be anchored in a second anchor trench located a minimum of two feet outside the bottom liner anchor trench as shown on Drawing C-107.The cover will consist of 4 to 8 feet of compacted non-residential area soil and tailing, overlain by an 18-inch thick layer of vegetated soil cover.

Flue dust materials will be placed in the repository in uniform compacted lifts to provide stability during placement of subsequent lifts and minimize long-term consolidation. Although anticipated to be small, some material movement may occur along the repository side slopes during placement and compaction of materials prior to closure. In order to reduce the stresses on the geomembrane liner on these side slopes, a non-anchored (minimum 2 feet runout) woven geotextile will be placed on the surface of the geomembrane on the side slopes. This geotextile is designed to slide along the surface of the geomembrane as the flue dust materials are placed and compacted, thus avoiding inducement of large tensile stresses in the geomembrane liner due to interface friction between the liner material and the flue dust.

Design of the repository cover system includes a non-woven geotextile layer (12 oz/sy, with a minimum puncture strength of at least 150 pounds), over the top geomembrane liner followed by at least 12 inches of fine grained tailing or water-quenched slag (2-inch minus) to protect the top liner. No demolition debris will be placed over the repository limits. Non-residential soils placed above the tailing or slag layer will be placed in 12 inch lifts compacted to 90 percent of the maximum dry density as determined by ASTM D 698 (Standard Proctor).

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL DesignVFinalXAVRemedial Design Rtpon Final.doc 18 April 2005 3.5 Consolidation of Non-Residential Area Soils and Tailing at the AV Smelter Site

3.5.1 Removal of Non-Residential Area Soils and Tailing from Areas Outside the Final Soil Cover

The non-residential area soils/tailing removal areas and depths at the AV Smelter site are shown on Drawing C-104. The total in-place volume of these materials to be removed is estimated to be 61,400 cubic yards. Excavated materials will be relocated to the central portion of the site, as shown on Drawings C-104 and C-106. Specific discussions of procedures for removing and relocating these materials are provided in Section 4.3.2.2.

3.5.2 Confirmation Sampling

Soil sampling will be conducted following excavation of non-residential area soils or tailing in areas outside of the final soil cover. The purpose of the confirmation sampling is to measure arsenic and lead concentrations in the 6-inch thick soil interval at the base of the excavated area to determine if further material removal is necessary.

The removal areas will be divided into decision units for confirmation testing. Each decision unit will encompass an area no greater than 22,500 ft2 (i.e., equivalent to an area 150 feet by 150 feet). This will result in approximately 80 non-residential area soils/tailing removal decision units at the AV Smelter site. Decision units will be established and sampled by the Field Project Supervisor (FPS; see Appendix E for definition of project roles) as work progresses.

Each decision unit will be divided into four quadrants of approximately equal size and a single 0 to 6 inch depth interval soil sample will be collected from each quadrant. The four grab samples will be composited to generate one sample per decision unit. The samples will be analyzed for arsenic and lead. The measured concentrations will be compared to removal confirmation levels of 650 mg/Kg arsenic and 6,500 mg/Kg lead. If both arsenic and lead concentrations are below the respective levels, non-residential area soils/tailing removal would be confirmed and no further excavation will be required within the decision unit. If either the concentration for arsenic or lead exceeds the respective removal confirmation levels in the decision unit, an additional one-foot of soil will be excavated from the decision units and the area will be resampled. This process will be repeated until both the lead and arsenic confirmation levels

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL DesignNFirulVAVRemediol Design Report Final doc 19 April 2005 have been achieved in the decision unit. Details of non-residential area soils/tailing removal confirmation sampling are provided in Appendix E (Quality Assurance Plan, Section 4.2.2).

3.6 Consolidation of Non-Residential Area Soils and Tailing at the CZL Mill Site

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3.6.1 Removal of Non-Residential Area Soils/Tailing from Areas Outside the Final Soil Cover

The non-residential area soils/tailing removal areas and depths at the CZL Mill site are shown on Drawing C-105. The total in-place volume of material to be removed is estimated at 8,200 cubic yards. Specific discussions of procedures for removing and relocating these materials are provided in Section 4.3.3.1.

3.6.2 Confirmation Sampling

Soil sampling will be conducted following excavation of non-residential area soils/tailing in areas outside of the final soil cover at the CZL Mill site. The sampling will be performed in the same manner as for non-residential area soils/tailing removal confirmation sampling at the AV Smelter site, as discussed in Section 3.5.2. Per that approach, the removal areas will be divided into decision units for confirmation testing. Each decision unit will encompass an area no greater than 22,500 ft2 (i.e., equivalent to an area 150 feet by 150 feet). This will result in approximately 8 non-residential area soils/tailing removal decision units at the CZL Mill site.

3.7 Soil Cover Over Consolidated Non-Residential Area Soils and Tailing at the AV Smelter and CZL Mill Sites

The consolidated non-residential area soils and tailing will be compacted and covered with 18 inches of clean soil obtained from an off-site borrow source. The cover areas are shown on Drawings C-106 (AV Smelter site) and C-105 (CZL Mill site). The consolidated materials and the initial 12 inches of the cover soil will be compacted to 90 % of the maximum dry density per ASTM D698. This density specification will minimize potential settlement, reduce the potential for infiltration and help achieve and maintain a uniform regraded surface.

ASARCO Incorporated MFC, Inc. J:\BLDOI\S344\5344-50\AV_CZL Design\Final\AVRemedial Design Report Final.doc 20 April 2005 Revegetation of the closure surface will be implemented to provide a sustainable protective cover to allow permanent protection from erosion while also providing a mechanism for evapotranspiration of water from the growth medium. Plant species that will be used to vegetate the cover surface have been selected to conform with the site conditions, climate, and soils. The selected species include: Standard crested wheatgrass (Agropyron desertorum), Streambank wheatgrass (Agropyron riparium), Smooth brome (Bromus inermis), Hard fescue (Festuca longifolia), Timothy (PMeum pratense), Little bluestem (Schizachyrium scopariurri), Cereal rye (Secale cereale), Cicer milkvetch (Astragalus deer), White dutch clover (Trifolium repens), and Regreen (Triticum aestivum x Elytrigia elortga). Seeding application rates for these plant species, application requirements, and fertilizer recommendations are provided in the Technical Specifications (Appendix D).

3.8 Borrow Area Development and Reclamation

As discussed in Section 2.3, an offsite borrow area will be developed to provide cover soil for remedial action construction. An evaluation of the feasibility of using borrow material from both new and existing borrow sites (such as the site north of the "Hecla/Malta Gulch Impoundment", the Oregon Gulch Impoundment borrow site, or the Apache Tailing Impoundments borrow site) is pending. A borrow area will be selected and investigated, as needed, at a later date. Once selected, access and haulage issues will be addressed. Haul traffic will be required to obey all State and local traffic laws, including load limits. The contractor will also be required to provide signage, flagpersons, or other appropriate traffic controls, as necessary, so as not to significantly interfere with the normal flow of traffic on roads near the Site.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL Design\Fin«l\AVRemedi»l Design Report Finnl.doc 21 April 2005 4.0 CONSTRUCTION CONSIDERATIONS

This section presents the construction procedures necessary to implement the remedial action construction. Information provided includes field management and oversight details and general construction sequencing and schedule requirements. In addition, methods for implementing the remedial actions are discussed, including material excavations, soil cover activities, flue dust repository construction, and revegetation of disturbed and cover areas. Dust and stormwater controls to be implemented during construction are also discussed. Finally, procedures for temporary work stoppages and decontamination procedures are described.

4.1 Field Management and Oversight

All construction operations associated with the remedy will be performed and managed by the remediation contractor selected by Asarco, with oversight provided by a field representative of MFG (the Supervising Contractor), or other designated representative of Asarco. Asarco has the overall responsibility for remediation of the site and any major changes in the scope of the construction work will be approved through Asarco. MFG, on behalf of Asarco, will be responsible for the overall completion of the project in accordance with all project requirements and the remediation contractor will be responsible for "day to day" operations at the site. All contractor submittals and project design changes will be approved by MFC's Engineer of Record.

MFG's FPS will be responsible for oversight of the contractor's operations, as well as other project monitoring, documentation and reporting requirements. The FPS's duties will include the performance or coordination of air monitoring activities, routine inspection of construction to verify compliance with the designs plans and specifications, oversight of quality control surveying and testing required, and performance or coordination of quality assurance activities. The FPS will document all inspections and work progress, maintain records of quality control and quality assurance testing, and maintain a record copy of the construction drawings for the preparation of as-built drawings at the completion of the project.

ASARCO Incorporated . MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZLDesign\Finil\AVRemeditlDesignReponFintl.doc 22 April 2005 4.2 General Construction Sequencing and Schedule Requirements

It is anticipated that remedial action construction at the AV/CZL site will be completed over two construction seasons. The construction season in the Leadville area is relatively short and for this reason a two-year schedule will be required to complete all of the tasks associated with the scope of work. Asarco does not own the site and therefore access will have to be obtained prior to initiation of any activities.

Remedial action construction activities will begin with mobilization of equipment and temporary facilities and site preparatory work. Mobilization and preparatory activities will include preparation of the staging area(s) for the construction contractor, installation of initial construction stormwater controls and other work necessary for site access. Concurrent with the contractor's mobilization activities, dust-monitoring equipment will be set-up at the site for use during earthwork operations involving the movement or disturbance of flue dust, non-residential area soils or tailing.

The detailed scheduling of construction activities will be the responsibility of the selected remediation contractor. However, the nature of the remedial action work places certain requirements on the sequence of activities to be performed, as discussed in the following sections.

4.2.1 AV Smelter Site

Prior to initiation of demolition work at the AV Smelter site, an asbestos inspection and removal will be performed. Non-friable asbestos has been identified in transite panels located in the former blast furnace building. However, the site, has not been inspected by a certified asbestos inspector and this will be performed prior to initiating demolition of structures required to allow access for remediation. The inspection will be performed in accordance with the requirements of Colorado Air Quality Control Commission Regulation No, 8 Part B. Materials identified as containing asbestos will be collected and disposed offsite in accordance with the requirements of Regulation No. 8 Part B.

Once asbestos has been removed from the AV Smelter site remediation areas, demolition of structures can be initiated. The first phase of demolition will be performed in areas where flue dust removals will be conducted, in the central processing area where the flue dust will be screened and stockpiled, and in the repository footprint. As described in Section 3.1, and identified on Drawing C-102, structures to be

ASARCO Incorporated MFG. Inc. J\BLDOI\5344\5344-50\AV_CZLDesign\FinllVAVRemedialDesignReponFiiul.doc . 23 April 2005 removed will be demolished to existing grade and structural materials will be reduced in size for relocation to the area to be covered by the soil cover. Salvageable materials will be relocated to the designated consolidation area. Once these activities are completed, demolition of smelter structures in other areas will be performed on a schedule to allow access to non-residential area soils/tailing removal and consolidation areas.

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Once demolition has been completed in flue dust removal areas, excavation of the flue dust will be performed. The excavated material will be screened and stockpiled in the central processing area until sampling confirms that flue dust materials have been removed from the target areas. The volume of flue dust will then be estimated by survey and the repository will be constructed to contain the actual volume of flue dust. After the flue dust has been relocated to the repository and any remaining structures within the final cover area have been demolished, there are no physical restrictions to consolidation and covering of the non-residential area soils and tailing at the AV Smelter site.

4.2.2 CZL Mill Site

Remedial actions at the CZL Mill site are independent of actions at the AV Smelter site. In addition, no demolition of structures is required at the CZL Mill site other than the removal of 5 timber utility poles. Therefore the construction contractor can consolidate non-residential area soils/tailing and install the soil cover at the CZL Mill site at any time during the overall remedial action construction.

4.3 Material Excavation and Soil Cover Activities

This section provides a discussion of the construction considerations associated with the required earthwork activities. The general requirements to effectively excavate and prepare various materials and surfaces are addressed, including borrow area operations, excavation of flue dust and excavation and/or grading of non-residential area soils and tailing, and placement and compaction of fill.

4.3.1 Borrow Area

As discussed previously, an offsite borrow area will be developed to provide cover soil for remedial action construction. Prior to the initiation of borrow activities a run-on control berm will be constructed

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5344-50\AV_CZLDtjign\FinnlUVRcmKlitlDejignRcpoitFinsl.doc 24 April 2005 upgradient of the area and silt fence, or other erosion control will be placed along the downgradient edge of the area. The upper four inches of soil will be stripped from the site and stockpiled for use in reclamation of the area. It is anticipated that the screening facilities and material stockpile locations will be established in the area of shallowest excavation and nearest the access to the haul road. Based upon required volume estimates and the anticipated material properties, the spatial dimensions and maximum depth of the borrow area will be determined.

Excavation of the borrow area will be advanced to provide positive drainage and prevent ponding at all times. To produce material for the cover soil, excavated soil will be screened to remove all rocks larger than 3-inches (maximum dimension). Unscreened borrow material, or pit-run, will be used as general fill as provided for in the specifications. The contractor will be encouraged to utilize finer-grained clayey soil (compared with the coarser soils) that may be present in the borrow area for the construction of berms for run-on and run-off control features and general fill. Where present in the borrow area, it is anticipated that this material may be difficult to screen because of its clay content.

Following completion of borrow activities, the excavated area will be graded and contoured to provide positive drainage and prevent ponding. The stripped topsoil will be spread on the regraded surface and revegetated in accordance with the specifications using the same requirements as the repository cover for seed species, fertilizer, and erosion and slope protection.

4.3.2 AV Smelter Site

As discussed in Section 4.2.1, remedial construction activities at the AV Smelter site include: (1) excavation of flue dust and, relocation to a fully-encapsulated lined repository; (2) excavation, and consolidation of non-residential area soils and tailing; and (3) installation of a soil cover over the consolidated non-residential area soils and tailing. The requirements associated with of each of these tasks are discussed in the following sections.

4.3.2.1 Flue Dust Excavation and Processing

Areas requiring flue dust material removal and initial removal depths are identified on Drawing C-104. Stormwater run-on control berms will be constructed around each flue dust removal area. After the excavation depths have been achieved, the base of the excavation will be sampled and analyzed as

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL Design\Final\AVRemedi»l Design Repon Finil.doc 25 April 2005 described in Section 3.3.2. Excavation will continue until the removal confirmation arsenic concentration level has been met. It is anticipated that excavations will be accomplished with standard excavator type equipment. Excavated material will be loaded into rubber tired end dump trucks that will haul the material to the central processing area for screening and stockpiling.

Excavated materials will be screened to separate out all structural materials (i.e., concrete, wood, bricks, rebar, etc.) with diameters greater than 2 inches. The material passing through the screen (flue dust) will be temporarily stockpiled until all flue dust material has been excavated and processed. Stockpiles will be tarped to prevent the flue dust from getting wet and to reduce the potential for generation of dust. Once all flue dust materials have been excavated and stockpiled, the volume of materials will be estimated by survey and the designed repository size adjusted accordingly.

4.3.2.2 Non-Residential Area Soils and Tailing Excavation and Placement

Non-residential area soils/tailing will be excavated from areas and depths outside the final soil cover area as shown on Drawing C-104. Excavators, dozers, graders or other equipment as selected by the construction contractor will perform the required removals. In general, excavation of non-residential area soils and tailing will progress from west to east to prevent recontamination of previously removed areas. The depth of excavation for specific removals are shallow, typically 6 inches, but up to 4 feet in relatively small areas. Depths of excavation required for specific areas are illustrated on Drawing C-104. As previously described, the final depth of excavation in a particular area will be determined by confirmation sampling.

Material generated from the excavation areas will be relocated to the area illustrated on Drawing C-1Q6. All excavated material will be placed in horizontal lifts approximately 8 to 12-inches in loose thickness and compacted to 90% of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D698). Water will be added to each layer or lift of material as necessary to achieve compaction. Compaction testing will be performed using nuclear density gauges in accordance with ASTM D2922 or sand-cone testing in accordance with ASTM D1556 at a frequency of one test per 3,000 cubic yards of material placed, or one test for each lift of material compacted in a given fill area, whichever is greater. Areas that fail to meet the compaction criteria will be reworked until a subsequent test yields acceptable results. The same compaction specifications will apply to the placement of tailing material, excavated subgrade soils and general fill material from the borrow area. The FPS may perform quality assurance

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344.50\AV_CZLDtsign\FinHl\AVRemcdijlDnignReponFiml.doc 26 April 2005 testing periodically. There are no compaction specifications for surfaces that have been excavated although areas that have had material removed will be uniformly graded after all removals have been completed. Excavated material that is too wet to achieve proper compaction will be spread and air-dried or blended with drier material, as necessary, to achieve proper moisture content for compaction.

The non-residential area soils/tailing will be placed to attain the contoured surface as shown on Drawing C-106 and will be prepared such that smooth continuous grades are achieved. The final graded surface will be prepared such that no rutting, and no debris, organic material, ponded water or frozen material or angular rocks larger than 3 inches in diameter are present within 4 inches of the final surface.

4.3.2.3 Soil Cover Placement

Cover soil will be transported from the borrow source and dumped with end dump trucks proximal to the area(s) being worked. Placement of the cover soil will proceed immediately following the placement and compaction of the non-residential soil and tailing. The placement of cover soil can be accomplished in sections provided consolidation and compaction requirements of the underlying materials have been met. Cover soil placement will be accomplished by using conventional grading equipment and such that a uniform thickness is maintained.

The first 12-inches of cover soil will be placed in a single loose lift as necessary to achieve a compacted thickness of 12-inches and compacted to at least 90 percent of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D-698). If needed, water will be added to the cover soil to achieve proper compaction. Compaction will not be required for the top 6-inches of the cover soil layer other than that achieved by the normal travel of placement and grading equipment.

In preparation for revegetation, the final cover soil surface will be graded to smooth uniform slopes toward the natural or created drainageways such that no irregularities are visible and no areas of ponded water or localized depressions exist.

4.33 CZL Mill

As discussed in Section 4.2.2, aside from the removal of 5 timbered power poles, there will be no demolition activities at the CZL Mill. Construction activities at the CZL Mill site include; the excavation

ASARCO Incorporated MFC, Inc. J:\BLMI\5344\5344-50\AV_CZLDelign\Final\AVRemedialDMignReponFimI.doc 27 April 2005 of non-residential area soils, and tailing; consolidation and compaction of non-residential area soils and tailing, and the installation of the soil cover. The requirements associated with of each of these tasks are discussed in the following sections.

4.3.3.1 Non-Residential Area Soils/Tailing Excavation

Similarly to the AV Smelter site, a grading plan has been developed to provide for a balance of cut and fill quantities with non-residential area soils and tailing generated from excavation activities placed in the area of the final soil cover at the CZL Mill site. In general, excavation of non-residential area soils will progress from north to south to prevent recontamination of previously removed areas. The excavation of tailing will proceed from south to north. The depth of excavation for specific removals are relatively shallow, typically 12 inches for non-residential area soils and approximately four feet in the area identified as tailing. Depths of excavation that will be required for specific areas are illustrated on Drawing C-105. As previously described, the final depth of excavation in a particular area will be based on the results of removal confirmation sampling. Excavators, dozers, graders or other equipment as selected by the construction contractor will perform the required removals.

Removed non-residential area soils/tailing will be consolidated in the final soil cover area and graded to the lines and grades shown on Drawing C-105. All excavated material will be placed in horizontal lifts approximately 8 to 12-inches in loose thickness and compacted to 90% of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D698). Water will be added to each layer or lift of material as necessary to achieve compaction. Compaction testing will be performed using nuclear density gauges in accordance with ASTM D2922 or sand-cone testing in accordance with ASTM D1556 at a frequency of one test per 3,000 cubic yards of material placed, or one test for each lift of material compacted in a given fill area, whichever is greater. Areas that fail to meet the compaction criteria will be reworked until a subsequent test yields acceptable results. The same compaction specifications shall apply to the placement of tailing material, excavated subgrade soils and general fill material from the borrow area. There are no compaction specifications for surfaces that have been excavated although areas that have had material removed will be uniformly graded after all removals have been completed. Excavated material that is too wet to achieve proper compaction will be spread and air-dried or blended with drier material, as necessary, to achieve proper moisture content for compaction.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZLDejign\Final\AVRemriialDnignReponFiral.doc 28 April 2005 The area excavated during tailing removal will be backfilled with soil from the borrow area. This fill material will be placed and nominally compacted by the passage of the placement equipment. The consolidated non-residential area soils/tailing will be graded to attain the contoured surface as shown on Drawing C-105 and will be prepared such that smooth continuous grades are achieved. The final graded surface will be prepared such that no rutting, and no debris, organic material, ponded water or frozen material or angular rocks larger than 3 inches in diameter are present within 4 inches of the surface.

4.3.3.2 Soil Cover Area

Cover soil will be transported from the borrow source and dumped with end dump trucks proximal to the area(s) being worked. Placement of the cover soil will proceed immediately following the placement and compaction of the non-residential area soils and tailing. The placement of cover soil may be accomplished in sections provided consolidation and compaction requirements of the underlying materials have been met. Cover soil placement will be accomplished by using conventional grading equipment and such that a uniform thickness is maintained.

The first 12-inches of cover soil will be placed in a single loose lift as necessary to achieve a compacted thickness of 12-inches and compacted to at least 90 percent of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D-698). If needed, water will be added to the cover soil to achieve proper compaction. Compaction will not be required for the top 6-inches of the cover soil layer other than that achieved by the normal travel of placement and grading equipment.

In preparation for revegetation, the final cover soil surface shall be graded to smooth uniform slopes toward the natural or created, drainageways such that no irregularities are visible and no areas of ponded water or localized depressions exist.

4.4 Repository Construction

This section provides details associated with the construction of the repository for flue dust. As described in Section 4.3.2.1, all flue dust will be excavated and stockpiled prior to construction of the repository. The volume of the flue dust will be estimated by survey, and the size of the repository adjusted accordingly. A revised repository design will then be prepared. Once the Engineer of Record approves the revised design, the repository will be constructed.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50VAV_CZL Deiign\Fin»l\AVRem«ii«l Doign Report Final.doc 29 April 2005 4.4.1 Repository Excavation

As indicated on the Drawing C-106, the maximum vertical depth of excavation for the repository is 10 feet below current grade in the northern corner of the repository footprint. It is estimated that approximately 9,000 cubic yards of soil materials will be excavated for the construction of the repository. As described previously, the repository will be founded in native alluvial soil. Material excavated as a result of the repository construction will be placed nearby in the final soil cover area.

The repository side slopes will be consistently maintained at 3(h):l(v). The primary objective in maintaining the 3(h):l(v) slope is to provide ease of construction and liner installation. A 3(h):l(v) slope will provide a more stable excavated surface versus a steeper slope and one that is capable of supporting construction equipment for final grading and installation of the liner system components. It is not anticipated that over-excavation (beyond the grades indicated on the excavation plan) will be required. In the event unsuitable materials are encountered during the excavation activities, the unsuitable materials will be removed and replaced with general fill from the borrow area. The extent of over-excavation, if necessary, will depend on the actual conditions encountered in the field. Replacement fill material placed in any area that has been over excavated will be compacted to the same specifications as the fill placed on the top surface of the soil cover area (90% of the Standard Proctor maximum dry density).

4.4.2 Liner System Installation

The bottom liner system will be installed on prepared alluvial subgrade that has been approved by both the FPS and liner contractor. The geomembrane liner will be sandwiched between two layers of heavy, nonwoven 12 oz/sy geotextile to add additional protection against puncture. The underlying layer of geotextile and the 60-mil HDPE geomembrane liner will extend up the 3(h):l(v) side slopes and be anchored in a trench at the slope crest on all sides. The bottom liner anchor trench will consist of a 4- foot-wide runout and a 2-foot-deep anchor trench. A 12-oz/sy geotextile cushion layer will be placed on the geomembrane surface in order to reduce the stresses on the geomembrane liner on the side slopes. The geotextile is designed to provide a cushion layer from the material placed in the repository and since this layer will not be anchored in an anchor trench it will be allowed to slide along the surface of the geomembrane as the flue dust materials are placed and compacted. This will reduce the inducement of large tensile stresses in the geomembrane liner due to interface friction between the liner and the

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\AV_CZL Deiign\Fin«l\AVRemcdi»l Design Report Final.doc 30 April 2005 repository materials. In addition to the stress relief, the geosynthetic layer will provide some protection from the construction equipment.

4.4.3 Leachate Collection Piping & Flue Dust Material Placement

The contractor will construct a temporary access ramp to allow construction equipment access into and out of the repository. The temporary access ramp will bridge over the crest of the geomembrane lined area to prevent damage to the liner.

Prior to placing the flue dust, a five foot length of four-inch diameter slotted drain pipe will be installed into the sump portion of the repository. The slotted pipe will be connected to a vertical riser pipe to allow the removal of any accumulated stormwater from the base of the repository. The slotted portion of the pipe will be wrapped with geotextile to keep fine-grained material from entering the slots, and the drain pipe will be supported while flue dust is placed around it.

Flue dust materials will be placed in the repository in uniform compacted lifts across the repository floor to provide stability during placement of subsequent lifts. Placement of the flue dust materials will be accomplished with loaders, end dump trucks or other means selected by the contractor provided acceptance by the FPS. Spreading the flue dust material will be accomplished by low ground pressure equipment. All flue dust material will be placed in horizontal lifts approximately 8 to 12-inches in loose thickness and compacted to 92% of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D698). Water will be added to each layer or lift of material as necessary to maintain the moisture content between optimum and 3 percent dry of optimum. Compaction testing will be performed using nuclear density gauges in accordance with ASTM D2922 or sand-cone testing in accordance with ASTM D1556 at a frequency of one test per 500 cubic yards of material placed, or one test for each lift of material, whichever frequency is greater. Areas that fail to meet the compaction criteria will be reworked until a subsequent test yields acceptable results. Material that is too wet to achieve proper compaction will be spread and air-dried or blended with drier material, as necessary, to achieve proper moisture content for compaction.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\J344-50\AV_CZL Dcjign\Finil\AVRemedi»l Design Report Final.doc 31 April 2005 4.4.4 Repository Top Liner and Cover System

Once all of the flue dust materials have been placed in the repository, the repository cover system will be installed. The repository cover system includes a 12 oz/sy, non-woven geotextile, both under and over the top of a 60 mil HDPE geomembrane liner. The geotextiles will serve as protective cushion layers for the geomembrane cover. The top liner system will be anchored in a second anchor trench located a minimum of two feet outside the anchor trench for the bottom liner (see Drawing C-107). Prior to the placement of the geocomposite cover liner, the upper surface of the flue dust materials will be certified in writing by both the FPS and the geomembrane liner manufacturer/installer.

The repository and repository cover liner system will be covered with between 4 to 8 feet of compacted non-residential area soils overlain by an 18 inch thick vegetated soil cover to protect the top liner and serve as an additional barrier and drainage layer.

In order to prevent future excavation into the repository liner system, a visual marker will be installed on the top of the non-residential area soils over the repository footprint. This will consist of an orange, plastic safety-type fencing material which will serve as a cautionary marker.

4.5 Revegetation

Vegetation will be established on the cover soil and all disturbed areas, including run-on and run-off control ditches not receiving riprap. The seed mix and requirements for fertilizer, mulch, erosion control fabrics, and other accessories are provided in the Technical Specifications (Appendix D). Seed application rates and fertilizer requirements are consistent for all areas to be vegetated. Drill seed application may be performed for slopes equal to or flatter than 3:1, however, slopes steeper than 3:1, must be seeded by dry broadcast or hydroseeding. Seed protection and erosion protection also varies depending on the grade of the area being vegetated. All slopes less steep than 3:1 will be mulched at a rate of 2 tons per acre using straw or hay crimped into the surface with a tackifier applied in all areas 10:1 or steeper. For slopes equal to or steeper than 3:1 the mulch application rate will be doubled to 4 tons per acre. For additional erosion protection on the cover soil placed on embankment side slopes 5:1 or steeper, strips of erosion control fabric will be placed, parallel to the crest, near the top of the slope and at the mid- point of the slope.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344.SO\AV_CZLDMign\Final\AVRemedialDeiigiiRepoitFiiul.doc 32 April 2005 4.6 Dust Control

During the course of remedial construction activities, movement of equipment and vehicles may generate dust in dry and windy conditions. A dust control program will be implemented to help reduce dust generation associated with the construction activities. Visual observations, real-time monitoring and dust samples collected at the site perimeter will be used to evaluate the effectiveness of the controls. Dust control practices to be utilized and a detailed description of the air monitoring program are presented in the Fugitive Emissions Dust Control Plan (Appendix F). In addition, an Air Pollution Emission Notice (APEN) will be submitted to the Air Pollution Control Division of the CDPHE. .

Dust control measures will be implemented during construction activities to minimize the potential for the generation and off-site migration of fugitive dust. Dust control will be achieved primarily by watering down work areas and vehicle traffic routes. Watering will be provided on an as-needed basis, as follows:

• During flue dust, non-residential area soils or tailing excavation or regrading activities; • During stockpiling and/or loading of flue dust, non-residential area soils or tailing for transport; and • To wet down truck loads to prevent any visible emissions during transport.

Additional dust control measures will be implemented in response to total suspended particulate (TSP) or lead concentrations measured above the action levels established in the Fugitive Emissions Dust Control Plan. Additional dust control measures will be aggressively implemented under arid or windy conditions, whenever dust plumes are observed leaving the site or as needed to address real-time TSP measurements. Additional dust control measures that may be used are: increased frequency of water spray applications, regulation of vehicle speed, placement of additional clean gravel as a ground cover in high dust generation areas, application of surfactant, or other appropriate measures. Care will be taken to avoid application of excessive amounts of water that may cause unacceptable working conditions or increase the possibility of surface run-off. If additional dust control measures do not eliminate visible dust, removal activities will be temporarily suspended until additional dust control measures have been implemented, or until adverse weather conditions abate. In order to minimize the impact haul trucks may have on public roads, gravel pads or other means may be constructed at the exit for the work areas to public roads to minimize the tracking of materials onto the streets and to minimize dust. Mud or dirt, which may be carried out onto public roads by construction traffic will be removed daily.

ASARCO Incorporated MFC, Inc. J:\BLD01\J3-M\3344-50\AV_CZL Dejign\Final\AVRcmtdi«l Delign Report Find doc 33 April 2005 The effectiveness of dust control measures will be evaluated using real-time monitoring equipment and laboratory analysis of dust samples. Air monitoring activities will be implemented to measure TSP levels and collect dust samples for laboratory analysis of lead, arsenic and cadmium. A description of the air monitoring equipment to be used, monitoring locations, and other monitoring procedures are provided in the Fugitive Emissions Dust Control Plan (Appendix F).

4.7 Stormwater Control

Details of stormwater controls to be implemented during remedial construction are presented in the Stormwater Management Plan (Appendix G). Several surface water diversions will be installed prior to the repository construction and non-residential area soils/tailing excavation and consolidation activities at the AV Smelter site. These will divert surface water runoff that would normally run across these areas, to minimize potential contaminant transport and to allow completion of the repository excavation and non- residential area soils/tailing consolidation.

The run-on/runoff control ditch will divert stormwater runoff from the area north of the work area to either east or west of the final soil cover area (see Drawing C-106). These ditches will rejoin as one ditch on the south side of the final soil cover area. A typical section and geometry of the control ditches are shown on Drawings C-303 and C-304.

Run-on control berms will be constructed around the flue dust excavation areas to preclude stormwater entry into the excavations. Run-on berms will also be placed upgradient of the flue dust stockpile and screening operations area, and runoff control berms will be used to direct stormwater that lands on the stockpile and screening operations area to a down gradient catch basin. The catch basin will be sized to contain a 100-yar 24-hour storm event. Stormwater that accumulates in the catch basin will be allowed to evaporate or removed and used as a compaction aid during placement of the flue dust in the repository. A leachate collection system consisting of a horizontal slotted drain pipe and vertical riser will be installed in the sump portion of the repository to allow the removal of any stormwater that accumulates above the bottom liner prior to installation of the top liner. Should it be necessary to remove stormwater from the repository sump, the stormwater will be transported to the Yak Tunnel Treatment Plant.

ASARCO Incorporated MFG, Inc. J:\BLD01\5344\3344-50\AV_CZL Design\Fiml\AVRemedi«l Design Repon Fiml.doc 34 April 2005 4.8 Temporary Work Stoppages

Temporary work stoppages may be required for reasons beyond the control of the parties involved. Construction activities will be planned to anticipate work stoppages to the extent practical, such as monitoring weather reports. To the extent that work stoppages may be anticipated, disturbed tailings or non-residential area soils will be graded to drain and left at stable slopes to prevent excessive erosion during the work stoppage.

In anticipation of unforeseen work stoppages, general work practices implemented during construction will include maintaining the site in a safe and tidy manner at all times. In addition, construction activities will be planned and executed to minimize erosion and damage to work progress if an unanticipated work stoppage occurs. Temporary slopes will be smoothly graded at the end of each day. Temporary drainage ditches will be constructed to route stormwater run-on around or away from the work areas. Flue dust, non-residential area soils, tailing and cover soil will be compacted as it is placed in lifts. Stored materials, such as seed and geotextiles, will be protected from weather, such as moisture and freezing. Stockpiles will be placed to minimize erosion.

4.9 Decontamination Procedures

The purposes of decontamination procedures are to: (1) minimize migration of contaminants of concern to off-site areas; and (2) minimize impacts to public streets and adjacent property. In general, it will not be necessary to decontaminate construction equipment while it is within the site. Decontamination will be implemented when equipment that has been in contact with flue dust, non-residential area soils or tailing leaves the site. Loose tailing, rock, and soil will be removed from trucks and heavy equipment by dry brushing prior to entering public roads. Use of water will be avoided, but water will be used if materials cannot be removed by dry brushing. Public roads will be swept as needed. Street sweepings will be deposited in areas to be covered by the soil cover.

Hand tools will be decontaminated by dry brushing at the conclusion of use on this project. Personnel decontamination protocols are included in the Health and Safety Plan (Appendix H).

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZLDesign\Final\AVRemedialDraignReportFiral.doc 35 April 2005 5.0 OPERATIONS AND MAINTENANCE

This section presents the long-term operation and maintenance (O&M) requirements of the remedy, including cover system inspection and maintenance, surface drainage controls inspection and maintenance, groundwater monitoring and institutional controls. A more detailed description of the long- term O&M requirements will be presented in a separate O&M Plan that will be developed at the completion of the remedial construction.

5.1 Cover System Inspection and Maintenance

The primary barrier for the AV/CZL site is an 18-inch soil cover. In addition, flue dust materials will be contained within a fully-encapsulated geomembrane liner, covered by between 4 and 8 feet of non- residential area soils and the final 18 inch clean soil cover. The soil cover will be inspected for indications of excessive differential settlement, erosion, cracking, sloughing or other potential problems that may affect the integrity or performance of the cover system. The success of vegetation efforts will also be assessed.

The top surface and embankments of the soil covers will be inspected for signs of erosion, ponding, and differential settlement. Inspections will be performed by Asarco quarterly in the first year after completion or remedial action construction and semi-annually for the next year. If evidence of erosion is noted the potential cause of the erosion will be assessed and maintenance activities, including minor regrading or the installation of erosion control devices, will be performed to help prevent a reoccurrence. Visible areas of minor ponding or settlement (less than six inches) on the top surface will be filled and regraded, as necessary. The location of these areas will be marked in the field and/or surveyed to facilitate on-going monitoring. Areas where settlement on the order of six to twelve inches is identified will be evaluated in more detail to determine the potential effects on the integrity of the cover. Appropriate.maintenance activities will be performed based on this evaluation. All areas disturbed by maintenance activities will be revegetated in accordance with the Technical Specifications (Appendix D).

Vegetation established on the cover system will be inspected at the end of the first growing season following completion. The assessment of the vegetative cover will include a visual inspection of cover and species diversity. Reseeding and/or the application of additional fertilizer may be implemented in

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\J3-W-50\AV_CZL Design\Final\AVRemediil Design Report Fiiul.doc 36 April 2005 areas where the vegetation has not performed well in relation to other areas. Additional details of the vegetation monitoring program will be provided in the O&M Plan.

5.2 Surface Drainage Controls Inspection and Maintenance

The run-on and run-off control features associated with the cover system at the AV and CZL sites will be inspected and maintained by Asarco after remedial action construction is complete. Inspections will be performed on a semi-annual basis and also following significant severe precipitation events for a period of two years following completion of the remedy.

Visual inspection will be conducted of all drainage ditches, berms, chutes, swales, channels, culverts and sediment control devices to verify operation, capacity, and the effectiveness of erosion control measures. Repairs will be made, as necessary, to restore each feature to its original condition in accordance with the as-built drawings and Technical Specifications. If the cause of any damage is determined to be an inadequacy in the design of any feature or erosion control measure, the area will be stabilized and a design change will be developed and submitted to EPA for approval.

5.3 Institutional Controls

The ROD requires implementation of institutional controls as a component of the remedy to provide notification that a barrier is in place, and to restrict land use to protect the integrity of the remedy in the cover areas. Lake County and/or City of Leadville zoning ordinances will be modified to create a zoning "overlay district" to provide a screening process to identify areas where special precautions or requirements may be necessary. Restrictions and requirements from the overlay district would not be placed outside the cover areas other than to prevent residential development. Land use and plans/proposals for future land use will be monitored and evaluated by EPA as part of the five-year review process. Asarco will continue to work with the EPA, CDPHE, Lake County, and the City of Leadville during the remedial action to establish any required legal or institutional mechanisms, as necessary, to maintain the integrity and effectiveness of the remedy.

One periodically occupied residence has been identified within the site. Asarco will offer the Owner services and cleanup consistent with the procedures, requirements, and standards of the LCCHP during

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL Dcsign\Fin>l\AVRein«li«l Design Rtpon Final.doc 3 7 April 2005 the remedial design. If and when future remediation occurs for the current resident, Asarco will conduct or fund the response activities consistent with the procedures and requirements of LCCHP.

5.4 Groundwater Monitoring

As required by the ROD, three groundwater wells (one upgradient and two downgradient of the repository) will be installed and monitored periodically. The proposed well locations are shown on Figure 5-1. The wells will be installed after remedial construction is complete and will be sampled on an annual basis. Groundwater field data collection procedures will consist of documentation of monitoring site conditions, measurements of field water quality parameters (temperature, pH, and conductivity), and collection of water samples for laboratory analysis for the parameters shown in Table 5-1.

Field parameter measurements and sample collection procedures will be performed in accordance with the Compendium of Standard Operating Procedures for the California Gulch CERCLA Site, Leadville Colorado, Revision 0.0, April 1996.

5.5 Reporting

Reports detailing the implementation and findings of all O&M activities will be prepared on an annual basis, consistent with the groundwater monitoring schedule, and submitted to EPA and CDPHE.

ASARCO Incorporated MFG. Inc. J:\BLDOI\S344U344-SO\AV_CZLDtsign\Finiil\AVRemedialDe9ignReponFiiul.doc 38 April 2005 6.0 REFERENCES CITED

Camp Dresser & McKee Inc. (COM). 1994a. Final Soils Investigation Data Report, California Gulch CERCLA Site, Leadville, Colorado. Prepared by Camp Dresser & McKee Inc. for Resurrection Mining Company. July.

Camp Dresser & McKee Inc. (COM). 1994b. Metal Speciation Data Report, California Gulch CERCLA Site, Leadville, Colorado. Prepared by Camp Dresser & McKee Inc. for Resurrection Mining Company. September.

Foothill Engineering Consultants, Inc. (FEC). 1996a. Cultural Resources Investigations of Selected Smelter Sites, Operable Unit 5, California Gulch Superfund Site, Lake County, Colorado. March.

Foothill Engineering Consultants, Inc. (FEC). 1996b. Addendum to Cultural Resources Investigations of Selected Smelter Sites, Operable Unit 5, California Gulch Superfund Site, Lake County, Colorado. July.

Foothill Engineering Consultants, Inc. (FEC). 2001. Draft Cultural Resources Mitigation Plan for the Arkansas Valley Smelter and Colorado Zinc-Lead Mill Sites, Operable Unit 5, California Gulch Superfund Site, Leadville, Colorado. April.

Colder and Associates, Inc. (Colder). 1996a. Final Surface Water Remedial Investigation Report, California Gulch Superfund Site, Leadville, Colorado. Prepared for Asarco Incorporated. May.

Colder and Associates, Inc. (Golder). 1996b. Final Hydrogeologic Remedial Investigation Report, California Gulch Site, Leadville, Colorado. Prepared for Asarco Incorporated. May.

Golder and Associates, Inc. (Golder). 1996c. Draft Smelter Feasibility Study, California Gulch Superfund Site, Leadville, Colorado. Prepared for Asarco Incorporated. May.

MFG, Inc. 2000. Final Focused Feasibility Study, Operable Unit 5, Arkansas Valley Smelter and Colorado Lead-Zinc Mill Site, California Gulch Superfund Site. Prepared for Asarco.

MFG, Inc. 2001 a. Sampling and Analysis Plan to Support Remedial Design, Operable Unit 5, Arkansas Valley Smelter and Colorado Lead-Zinc Mill Site, California Gulch Superfund Site. Prepared for Asarco.

MFG, Inc. 2001 b. Remedial Construction Report Completion Report Final Phase. Former Murray Smelter Site. Prepared for Asarco.

Morrison, Knudsen Corporation (MK). 1992. Final Report for the Lead Slag Pile Remedial Investigation at the California Gulch Site, Leadville Colorado. Prepared for Denver & Rio Grande Western Railroad Company.

Shepherd Miller, Inc./Terra Matrix, Inc. (SMI/TMI). 1995. Final Engineering Evaluation/Cost Analysis for Colorado Zinc Lead Tailing Area within Lower California Gulch Operable Unit 8. July 1995.

U.S. Environmental Protection Agency (EPA). 1993. Final Screening Feasibility Study for Remediation Alternatives at the California Gulch NPL Site, Leadville, Colorado. September.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZL Design\Fin«I\AVRemedi«l Deiign Report Final.doc 39 April 2005 U.S. Environmental Protection Agency (EPA). 1996. Baseline Human Health Risk Assessment, California Gulch Superfund Site, Leadville, Colorado. Prepared by Roy F. Weston, Inc. January 2, 1996.

U.S. Environmental Protection Agency (EPA). 1997. Ecological Risk Assessment for the Terrestrial Ecosystem, California Gulch NPL Site, Leadville, Colorado. Prepared by Roy F. Weston, Inc. and Terra Technologies. January.

U.S. Environmental Protection Agency (EPA). 1985. Remedial Action at Waste Disposal Sites, EPA/625/6-85/006. Cincinnati, Ohio.

Walsh and Associates, Inc. (Walsh). 1993a. Smelter Remedial Investigation, California Gulch Superfund Site, Leadville, Colorado. Prepared for Asarco Incorporated. April.

Walsh and Associates, Inc. (Walsh). 1993b. Lead Speciation Study, Leadville, Colorado. October.

WESTEC. 1997a. Smelter Supplemental Remedial Investigation Work Plan, California Gulch CERCLA Site. Prepared for Asarco Incorporated. October.

WESTEC. 1997b. Final Draft Smelter Feasibility Study, California Gulch CERCLA Site, Leadville, Colorado. January.

Woodward-Clyde Consultants, Inc. (WCC). 1992. Smelter Site Reconnaissance Report, California Gulch Site, Leadville, Colorado.

Woodward-Clyde Consultants, Inc. (WCC). 1994. Tailings Disposal Area Remedial Investigation Report, California Gulch Site, Leadville, Colorado.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL Dejign\Fmal\AVRemedial Design Report Final.doc 40 April 2005 TABLES Table 5-1 Groundwater Sampling Laboratory Analytical Parameters

Parameter (l) Detection Limit (mg/L) Method(I) Holding Time (days)

Total Alkalinity (as CaC03) 2.0 EPA 2320B 14

Calcium 1<.0 EPA 200.7 (1CP) 180

Magnesium 1.0 EPA 200.7 (ICP) 180

Sulfate 10 EPA 375.3 Gravimetric 28

Arsenic 0.001 EPA 206.2 (GFAA) 180

Cadmium 0.02 EPA 200.7 (ICP) 180

Copper 0.05 EPA 200.7 (ICP) 180

Iron 0.05 EPA 200.7 (ICP) 180

Lead 0.001 EPA 239.2 (GFAA) 180

Manganese 0.03 EPA 200.7 (ICP) 180

Zinc 0.05 EPA 200.7 (ICP) 180 10.0 Total Dissolved Solids (TDS) EPA Ml 60.1 Gravimetric 180° C 7

(1) Samples will be analyzed for dissolved (filtered) metals only. (2) Other analytical methods achieving comparable detection limits may be used. FIGURES DENVER AND RIO GRANDE WESTERN

CALIFORNIA GULCH

SUPERFUND SITE BOUNDARY

.5 1.0 2.0

SCALE IN MILES ASARCO, Incorporated REMEDIAL DESIGN REPORT (OU5) - CALIFORNIA GULCH SITE FIGURE 1-1 CALIFORNIA GULCH SITE LOCATION MAP

PROJECT: 010179.3 DATE: JULY 2004 REV: BY: MAL | CHECKED: DLL MFC, Inc. consulting scientists and engineers LEGEND

APPROXIMATE OU5 SITE BOUNDARIES

FORMER SMELTER SITE

STREAM/DRAINAGE

DIRT ROAD

WESTERN ZINC SMELTER SITE

COLORADO ZINC-LEAD = MILL SITE

ARKANSAS VALLEY SMELTER SITE

GRANT/UNION 1 -SHARED BOUNDARY- SMELTER SITE- WITH OU3

•ARKANSAS VALLEY SOUTH HILLSIDE SCALE

2000 0 2000 FEET ASARCO, Incorporated ASBESTOS MmCMION PLAN (OU5) - CALIFORNIA GULCH SfTE FIGURE 1-2

OU5 AV/CZL SITE LOCATION MAP 0" >-X

PROJECT: 010179.3 DATE: SEPTEMBER 2004 REV: BY: PEP | CHECKED: DLL MFG, Inc. consulting scientists and engineers APPROXIMATE LIMIT OF OU5 BQUNDARY

APPROXIMATE LIMIT OF OU5 BOUNDARY

SMELTER SITE

/ — , > OU8 BOUNDARIES JNo. FEATURE DESCRIPTION ORE HOUSE/BLAST FURNACE #1b POWER Sc BLOWER HOUSE #1c BOILER HOUSE §2 BAG HOUSE SYSTEM #3 MIXING & ROASTING AREA AV SLAG PILE. #4o SULFIDE/ORE BIN #4b SULFIDE/ORE BIN STACK & FLUE DEBRIS. THAW HOUSE, COTTREL #6 THAW HOUSE, HEATING PLANT & STACK BASE §7 CONCRETE ARCH #8 STACK BASE #9 LOADING PLATFORM #10 TRASH SCATTER #15 MATTE HOIST HOUSE #A MACHINE SHOP ASSAY LAB TRANSFORMER HOUSE A5ARCO. Incorporated REMEDIAL DESIG:SICN REPORT (ous) -^CALIFORNIA OU8 BOUNDARIES FIGURE 1-3 AV/CZL SITE CULTURAL FEATURES LEADVILLE WATER TREATMENT PROJECT: 5344.50 DATE: "NOVEMBER 2003 PLANT BY: LAC j CHECKED: DLL MFC, Inc. consulting scientists and engineers APPROXIMATE LIMITS OF SOIL COVER AREA

FLUE DUST REPOSITORY

AiiAkCO. Incorporated REMEDIAL DESIGN REPORT (OU5) - CALIFORNIA GULCH SITE FIGURE 5-1 PROPOSED GROUNDWATER WELL LOCATION PROPOSED GROUNDWATER APPROXIMATE GROUNDWATER ELEVATION CONTOURS MONITORING WELL LOCATIONS 9800 BASED ON 12/92 DATA (SEE MFC, 2000) SCALE PROJECT: 010179.3 DATE: JULY 2004 REV: BY: SCG| CHECKED: ACK 120 120 FEET MFC, Inc. consulting scientists and engineers DRAWINGS consulting PROJECT scientists and ASARCO incorporated LOCATION engineers

4900 Peart East Circle, Suite 30OW. Boulder. Colorado 80301 Phone (303) 447-1823 CALIFORNIA GULCH SUPERFUND SITE Fax (303) 447-1836 LEADVILLE, COLORADO ARKANSAS VALLEY (AV) SMELTER/COLORADO

ZINC-LEAD (CZL) MILL SITE, OPERABLE UNIT 5 REFERENCE DRAWING TITLE DRAWING NO. TITLE SHEET AND LOCATION MAP 534451 G-001

GENERAL NOTES, SYMBOLS AND ABBREVIATIONS 534451G-002 COLORADO Location Map EXISTING SITE PLAN 534451C-101

DEMOLITION PLAN - AV SMELTER 534451C-102

BORROW AREA PLAN & SECTIONS 534451C-103

EXCAVATION PLAN - AV SMELTER . 534451C-104

BY DATE EXCAVATION & REGRADING PLAN - CZL MILI 534451 C-105 REVISIONS ISSUE FOR REVIEW DLL 7/04 REGRADING PLAN - AV SMELTER 534451C-106

FLUE DUST REPOSITORY PLAN, SECTIONS AND DETAILS 534451 C-107 REGRADING PLAN SECTIONS AND DETAILS - AV SMELJER. 534451C-301

REGRADING PLAN SECTIONS AND DETAILS - CZL MJJ 534451C-302

RUN-ON/RUN-OFF CONTROL CHANNEL PROFILES - AV SME1TEB 534451C-303 IESICNED BY: SCG JUK CHECKED BY: PEP RUN-ON/RUN-OFF CONTROL CHANNEL PROFILES AND DETAILS - CZL Mill 534451C-304 APPROVED BY: CTB RLE: MFG-STD VIEW NAME: PLAN RUN-ON/RUN-OFF CONTROL SECTIONS AND MISCELLANEOUS DETAILS 534451C-501 ORIGINATION DATE: 01/01/04 •LOT SCALE: 1.1 OR 1:2 JULY 20O4

(SOURCE: USeS TOPOGRAPHIC HAP. 1:50,000 SCALE. COUNTY MAP SOBES, LAKE COUNTY. COLORADO. 1979) ASARCO, Incorporated ?' Z! AV/CZL SITE - OU5 1/4 I VICINITY MAP TITLE SHEET AND LOCATION MAP

» DRAWING NO. REV.NO. 534451 G-001

SHEET OF 14 I _ J ___ 4 ABBREVIATIONS: GENERAL NOTES: ft AND SYMBOLS & LINES LEGEND! •. D1A. DIAMETER 1. ALL CONSTRUCTION SHALL CONFORM TO THESE PLANS AND SPECIFICATIONS. AC ASPHALTIC CONCRETE SOB. COVER MATERIAL BGS BELOW GROUND SURFACE 2. THE CONTRACTOR SHALL MARK ALL AREAS TO BE EXCAVATED AND THE CONTRACTOR SHALL BE RESPONSIBLE BMP BEST MANAGEMENT PRACTICES CONCRETE FOR ANY DAMAGE RESULTING FROM EXCAVATION. CF CUBIC FOOT CJ CONSTRUCTION JOINT COMPACTED TAILINGS 3. THE CONTRACTOR SHALL IMPLEMENT CONTINUOUS DUST CONTROL MEASURES AS REQUIRED BY THE SITE CENTERUNE FUGITIVE DUST CONTROL PLAN AND AS DIRECTED BY THE COMPANY REPRESENTATIVE. CONTRACTOR SHALL CHAIN LINK IN-PLACE TAILINGS IDENTIFY SOURCE(S) OF WATER FOR DUST CONTROL AND SHALL OBTAIN ALL NECESSARY PERMITS. CLR CLEARANCE CMP CORRUGATED METAL PIPE EXISTING GROUND 4. THE TYPES, LOCATIONS, SIZES AND/OR DEPTHS OF EXISTING UNDERGROUND UTILITIES AS SHOWN ON THESE CONCRETE CONC. rtl IMPROVEMENT PLANS WERE OBTAINED FROM SOURCES OF VARYING RELIABILITY. THE CONTRACTOR IS CY CUBIC YARD VEGETATION CAUTIONED THAT ONLY ACTUAL EXCAVATION WILL REVEAL THE TYPES. EXTENT. SIZES. LOCATIONS. AND DECON. DECONTAMINATION DEPTHS OF SUCH UNDERGROUND UTILITIES. A REASONABLE EFFORT HAS BEEN MADE TO LOCATE AND DWG DRAWING FENCE consulting DELINEATE ALL KNOWN UTILITIES. HOWEVER. THE COMPANY AND COMPANY'S REPRESENTATIVE ASSUME NO EA EACH RESPONSIBILITY FOR THE COMPLETENESS OR ACCURACY OF THE DELINEATION OF SUCH UNDERGROUND ECRM EROSION CONTROL SILT FENCE (EROSION CONTROL) scientists and UTILITIES NOR FOR THE EXISTENCE OF OTHER BURIED OBJECTS OR UTILITIES WHICH MAY BE ENCOUNTERED REVEGETATION MAT engineers BUT WHICH ARE NOT SHOWN ON THESE DRAWINGS. EL. ELEV. ELEVATION VISIBLE MARKER EP EDGE OF PAVEMENT 4900 Peart East Circle. Suits 300W. 5. THE CONTRACTOR SHALL EXPOSE AND VERIFY LOCATIONS AND ELEVATIONS OF EXISTING UNDERGROUND EX..EXIST. EXISTING CHE- OVERHEAD ELECTRICAL LINE Boulder. Colorado 80301 UTILITIES PRIOR TO CONSTRUCTION ACTIVITIES, FL ROW LINE Phone (303) 447-1823 Fax (303) 447-1836 G GAS EXISTING SANITARY SEWER LINE 6. ALL AREAS REQUIRING BACKFILL ARE TO BE COMPACTED IN CONFORMANCE WITH THE SPECIFICATIONS. ALL GAL GALLON WORK SHALL BE CONFINED TO THE LIMITS OF WORK AS SHOWN ON THE PLANS. GALV. GALVANIZED NEW SANITARY SEWER LINE GCL GEOCOMPOSITE CLAY UNER 7. CONTRACTOR SHALL BE RESPONSIBLE FOR THE PROTECTION OF ALL EXISTING MONUMENTS. SURVEY GW GROUNDWATER GEOTEXTILE FABRIC MARKERS. STREET SIGNS. UTILITIES. PAVEMENT. TREES, FENCES. AND ANY OTHER IMPORTANT OBJECTS ON HORIZ. HORIZONTAL THE JOB SITE AS IDENTIFIED BY THE COMPANY'S REPRESENTATIVE. HOPE HIGH DENSITY POLYETHYLENE GEOMEMBRANE LINER HWY. HIGHWAY 8. ALL STORMWATER AND EROSION CONTROL BMPs SHALL BE PLACED AS REQUIRED BY THE STORMWATER INV. INVERT GROUNDWATER MANAGEMENT PLAN. AS PRESENTED IN THE SPECIFICATIONS. OR AS DETERMINED BY THE COMPANY'S IRR IRRIGATION REPRESENTATIVE. LB POUND --L — STREAM LF LINEAR FOOT REFERENCE 9. IN ADDITION TO THE WORK SHOWN ON THESE PLANS THE CONTRACTOR SHALL RESTORE 00 AN EQUAL OR LLDPE LINEAR LOW DENSITY POLYETHYLENE BETTER CONDITION) OR REPLACE (TO AN EQUAL OR BETTER CONDITION) ALL PRIVATELY OWNED FENCES AND LT LEFT OTHER PERMANENT FACILITIES REMOVED OR DAMAGED DURING CONSTRUCTION. UNLESS REQUESTED MAX. MAXIMUM CENTERUNE OTHERWISE. MINIMIZE DISTURBANCE TO ADJACENT PROPERTY OWNERS AND RESIDENTIAL AREAS TO THE MH MANHOLE EXTENT POSSIBLE DURING WORK. Ml MILE --- I5A ----- TEMPORARY (CONSTRUCTION) EASEMENT LINE MIN. MINIMUM i N NORTH PROPERTY LINE NTS NOT TO SCALE SURVEY AND COORDINATE CONTROL NOTES: OC ON CENTER EXISTING TREES OH OVERHEAD LINE 1. EXISTING MAPPING BASED UPON AERIAL PHOTOGRAPHY/SURVEY BY ROCKY MOUNTAIN AERIAL MAPPING, INC.. POINT OF CURVATURE LIMITS OF TAILING OCTOBER 2000. CONTOUR INTERVAL - 2 FT. COMPANY AND COMPANY'S REPRESENTATIVE MAKE NO PC POINT OF INTERSECTION WARRANTY AS TO ACCURACY. CONTRACTOR SHALL STAKE HORIZONTAL AND VERTICAL POSITION OF ALL P1.P.I. PROPERTY LINE UNPAVED ROAD PROJECT COMPONENTS PRIOR TO CONSTRUCTION. PL PP POWER POLE. POLYPROPYLENE PRC POINT OF REVERSE CURVE PAVED ROAD PT POINT OF TANGENCY R RADIUS EXISTING SETTLEMENT PLATE/MONUMENT RCP REINFORCED CONCRETE PIPE RED. REDUCER MONITORING WELL ROW.R/W RIGHT OF WAY SITE SECURITY NOTES: RT RIGHT SOIL BORING RAILROAD 1. SECURE ALL EXCAVATION AREAS. CONTRACTOR IS RESPONSIBLE FOR SAFETY OF ALL PERSONNEL CONDUCTING RR NO. REVISIONS BY SO STORM DRAIN PIEZOMETER REMEDIATION ACTIVITIES. SHEET SHT. ISSUE FOR REVIEW DLL 7/04 SWPPP STORMWATER POLLUTION PREVENTION PLAN POWER POLE SOFT SQUARE FOOT SQYD SQUARE YARD MANHOLE SS SANITARY SEWER TEL TELEPHONE INDICATES REVISIONS TEMP TEMPORARY THRU THROUGH SPRING TOC TOP OF CONCRETE TV TELEVISION TYP. TYPICAL SURVEY CONTROL POINT UG UNDERGROUND UTIL UTILITY TEST PIT VERT. VERTICAL VPC VERTICAL POINT OF CURVATURE MINI-PIEZOMETER DESIGNED BY: VPI VERTICAL POINT OF INTERSECTION DRAWN BY: VPT VERTICAL POINT OF TANGENCY CHECKED BY: PEP \o °- W WATER APPROVED BY: ?9 ?8 WP WATER - PRIVATE •~ 2 VIEW NAME: PLAN x x (O ~ ORIGINATION DATE: 01/01/04 1. 'LOT SCALE: V.I OR V.2 ft in JULY 2004 >5 11 ASARCO, Incorporated ° C AV/CZL - OU5 GENERAL NOTES. SYMBOLS AND ABBREVIATIONS

DRAWING NO. 634451G-002

SHEET ~_ OF ' «* N 513.000 8

APPROXIMATE LIMIT OF OU5 BOUNDARY

consulting PROVIDE SAFE ACCESS TO RESIDENCES DURING CONSTRUCTION scientists and engineers

4-900 Pearl East Circle. Suite JOOW, Boulder. Colorado 80301 Phone (303) 447-1823 Fax (303) 447-1B36 N 512.

FOR _ GAS PIPELINE ( LOCATION UN

REFERENCE

CALIFORNIA GULCH

OU8 BOUNDARIES

N 511.OOO

REVISIONS DATE

ISSUE FOR REVIEW 7/0*

N 510.000 p—] DESIGNED BT: UMK JRAWN BY: CHECKED BY: PEP FEATURE DESCRIPTOR APPROVED BY:

ORE HOUSE/BLAST FURNACE VIEW NAME: PLAN LEADV1LLE WATER POWER & BLOWER HOUSE ORIGINATION DATE: 01/01/04 TREATMENT PLANT BOILER HOUSE 'LOT SCALE: 1:1 OR 1:2 BAG HOUSE SYSTEM JULY 2004 MIXING & ROASTING AREA SULFIDE/ORE BN N ASARCO, Incorporated SULFIDE/ORE BIN STACK & FLUE DEBRIS, THAW HOUSE. COTTREL THAW HOUSE. HEATING PLANT & STACK BASE AV/CZL SITE - (OU5) CONCRETE ARCH STACK BASE LOADING PLATFORM TRASH SCATTER EXISTING SITE PLAN MATTE HOIST HOUSE MACHINE SHOP ASSAY LAB TRANSFORMER HOUSE DRAWING NO. REV.NO. N 509,000 p- 534451C-101

SHEET 14 UM(T OF AERIAL SURVEY

BUILDINGS IN THIS AREA SHALL NOT BE DISTURBED PROVIDE SAFE ACCESS TO RESIDENCES DURING CONSTRUCTION

consulting PRIVA RES DENCES scientists and engineers

-~-^ --~^ \ 4900 Pearl East Circle, Suite JOOW. Boulder. Colorado 80301 Phone (303) 447-1823 --MARKED FOR BURIED Fax (303) 4-47-1836 GAS PIPELINE (PIPELINE NKNOWN)

CONCRETE (DEWEY) TO REMAIN IN DEMOLISH LOADING RAMP STACK DEBRIS (SEE NOTE 3) SEE NOTE 1 DEMOLISH CONC LOADING PLATF DEMOLISH WALL GRADE TO GRADE REMOVE DEBRIS FROM WITHIN Q STACK BASE TO STACK BASE TO REMAIN IN FOUNDATIONS; DEMOLISH EXISTING REMAIN IN PLACE PLACE; REMOVE DEBRIS FOUNDATIONS AND WALLS TO SURROI (SEE NOTE 3) FROM IN AND AROUND THE AND PLACE CLEAN FILL IN BASE (SEE NOTE 3) AREAS. AS NECESSARY: R EASTERNMOST ORE BINS METAL/WOOD FOUND IN THIS TO REMAIN IN PLACE SEE NOTE 3)

DEMOLISH STRUCTURES AND PLACE DEBRtS\N SOIL DESIGNATED METAL AREA JUNKYARD SEE NOTE 1 DEMOLISH WESTERN ORE BIN AND OU5 BOUNDARY PLACE DEBRIS IN SOIL COVER

OLD FOUNDATIONS TO GRADE-OR PLACE CLEAN FILL, AS NECESSARY; REMOVE SCRAP. FOUND IN THIS AR

MATERIALS IN SCRAP AREA THIS AREA SHALL SEE NOTE 1 NOT BE MOVED

SCRAP AREA SEE

BUILDINGS MATERIALS II AREA SHALL BE DISTURBED

ASARCO, Incorporated NOTES: 1. METAL DEBRIS SHALL BE RELOCATED TO DESIGNATED AV/CZL SITE - OU5 SALVAGED SCRAP METAL AREA. OTHER DEBRIS SUCH AS CONCRETE AND BRICK SHALL BE DEMOLISHED TO GRADE AND PLACED IN THE AREA TO BE COVERED BY THE SOIL COVER. MAXIMUM DEBRIS SIZE FOR MATERIALS TO BE DEMOLITION PLAN - PLACED WITHIN THE ON-SITE COVER AREA SHALL BE 10 FEET. AV SMELTER

2. RRE HYDRANTS AND WATER PUMPS FOUND THROUGHOUT THE SITE SHALL NOT BE DISTURBED. THE LOCATIONS ARE DRAWING NO. NOT IDENTIFIED ON THE DRAWINGS. 4451C-102 3. TAPER EXCAVATIONS TO PROVIDE 2(H):1(V) SIDE SLOPES AROUND ALL STRUCTURES TO REMAIN. consulting scientists and engineers

4900 Peart East Circle, Suite 300W. Boulder, Colorado 80301 Phone (303) 447-1823 Fox (303) 447-1836

REFERENCE

BORROW AREA AS NOT

NO. REVISIONS BY EN CHOSEN AT TH S T ISSUE FOR REVIEW DLL 7/04

3ESICNED BY: iRAWN BY: sec CHECKED BY: PEP APPROVED BY: 31 MFG-STO PLAN ORIGINATION DATE: 01/01/04 PLOT SCALE: 1:1 OR 1:2 DATE: JULY 2004 ASARCO, Incorporated AV/CZL SITE - OU5

BORROW AREA PLAN & SECTIONS

DRAWING NO. REV.NO. B34451C-103

SHEET OF 14 ,.. INE (PIPELINE 1 LOCATION UNKNOWN) \ consulting ABANDONED scientists and _A \ RESIDENCE .;.'.' \ \V-^ engineers

Boulder. Colorado 80301 Phone (J03) 447-1823 RAILROAD CAR Fax (303) 447-1836 18' X 18" WOOD LOADING RAMP BOX CULVERT

OVE PILES OF -GRAINED MATERIAL (FLUE DUSJT AS DIRECTED- EXCEPT FOR.JJJUE-DUST REPOSITORY. /^MATERIAL >TTl5lS AREA NOT TO BE * EXCAVATED j(SEE" DWG. 534451 C-106X FOB^EGRADING PLAN) JUNKYARD SEE NOTE 3 FLUE DUST REPOSITORY

CONSOLIDATION^ REVISIONS I BY AND REPOSfjORY UMITS

BUILDING THIS AREAxSHAtt-NOT BE /DISTURBED WITHOUT- APPROVAL. OF ,COMPANY'S REPRESENT "

LIMITS AND INITIAL DEPTH OF 1. MATERIAL REMOVAL DEPTHS WILL BE CONFIRMED BY SAMPLING TAILING EXCAVATION CONDUCTED BY COMPANY'S REPRESENTATIVE. PERFORM ADDITIONAL REMOVALS AS DIRECTED. LIMITS AND INITIAL DEPTH OF NON-RESIDENTIAL SOIL AREA 2. FIRE HYDRANTS AND WATER PUMPS FOUND THROUGHOUT THE EXCAVATION SITE SHALL NOT BE DISTURBED. THE LOCATIONS ARE NOT IDENTIFIED ON THE DRAWINGS. CONTRACTOR SHALL IDENTIFY LIMITS AND INITIAL DEPTH OF ASARCO, Incorporated PRIOR TO CONSTRUCTION. NON-RESIDENTIAL SOIL AREA EXCAVATION 3. NON-SALVAGEABLE MATERIAL FOUND WITHIN THE JUNKYARD AV/CZL SITE - OU5 UMFTS AND INITIAL DEPTH OF SHALL BE MOVED TO A NEARBY OUT OF THE WAY LOCATION NON- RESIDENTIAL SOIL AREA TO ALLOW FOR APPROPRIATE EXCAVATION. EXCAVATION EXCAVATION PLAN - 4. DO NOT EXCAVATE SOIL INSIDE DRIP LINE OF TREES GREATER LIMITS AND INITIAL DEPTH OF FLUE THAN 2 INCHES IN DIAMETER OR BENEATH DENSE SHRUBBERY. AV DUST EXCAVATION CONTRACTOR SHALL PROTECT TREES AND SHRUBBERY AS NECESSARY DURING CONSTRUCTION. UMiTS AND iNiriAL DEPTH OF FLUL DRAWING NO. DUST EXCAVATION 5. CONTRACTOR SHALL SUPPORT UTILITY POLES AS NECESSARY DURING CONSTRUCTION. 4451C-104

6. QUANTITY ESTIMATES BASED UPON MATERIAL DEPTHS INDICATED. consulting REGRADED AREA. scientists and EE DRAWING O<502. engineers 4900 Pearl East Circle. Suite 300W. Boulder, Colorado 60301 Phone (303) 447-1823 Fox (303) 447-1836

DO NOT DISTURB 24> CMP

LIMITS NON-RESI AREA SOIL REMOVAL

NON-RESIDENTIAL AREA SOIL CONSOLIDATION AR

UMfT OF AERIAL SURVEY

-RESIDENTIAL SOL REMOVE OLD- CONSOLIDATION AREA POWERUNE POLES, IF NECESSARY NOTE 2 RUN-OFF CHUTE '/MARUN

APPROXIMATE LIMITS AND DEPTH OF DISTURB NON-RESIDENTIAL SOIL EXCAVATION ETAINING WALL EXISTING LINE POLE. IF .NECESSARY NON-RESIDENTUU. SOIL CONSOLIDATION AREA

RUN-OFF 1. CONTRACTOR SHALL SUPPORT UTILITY POLES BERMS AS NECESSARY DURING CONSTRUCTION. TOP OF BANK 2. CONTRACTOR SHALL PROTECT TREES AND ' SHRUBBERY AS NECESSARY DURING CONSTRUCTION.

EXCAVATE LOWER TAILING 3. PERIMETER BERM NOT SHOWN IN REGRADE AREA AS DIRECTED; UPON TOPOGRAPHY. DIRECTION FROM COMPANY'S 4. OWNER WILL ARRANGE FOR UTILITY POLE TO REPRESENTATIVE, BACKFILL ASARCO, Incorporated WITH BORROW SOIL AND BE EXTENDED TO ACCOUNT FOR ELEVATION 'REGRADE EXCAVATION CHANGE, N AV/CZL SITE - OU5 EXCAVATION & CALIFORNIA GULCH REGRADING PLAN - CZL MILL

UKAWING NU. 634451C-105 TABLE OF COORDINATES

STOCKPILE FLUE DUST consulting IN THIS AIJEA DORING ^CONSTRUCT EAST scientists and CONSTRUCTION OF\ / RUN-ON CONTROL engineers 4900 Pearl East D'rcle. Suite 300W APPROXIMATE LIMITS Boulder. Colorado 80301 OF SOIL COVER AREA Phone (30i) 447-1823 Fax (303) 447-1836

6 Y10 Y 12 ^ CONSTRUCT WEST RUN-ON CONTROL DITCH

POND «55'x65Px4'/i /''

CONSTRUCT g(JN-OFF/13 DUST CONTROL ^ REPOSITORY

INSTALL TEll«PORARY FENCE

INSTALL NEW 36"« HOPE CULVERT (200'±)

ASARCO. Incorporated AV/CZL SITE - OU5

REGRADING PLAN - AV

DRAWiNG NO. B34451C-106 9860 9856 TOP OF CONSOLIDATED TAILING & NON-RESIDENTIAL SOILS TOP OF FLUE DUST 9852 REPOSTORY 9848 EXISTING GROUND 9844 LEACHAJE COLLECTION PIPING SURFACE 9840 4-INCH DIA. SCH. 40 9836 PVC CONNECTED TO LATERAL WITH TEE 9832 BOTTOM OF FLUE consulting 9828 - PERFORATED 4-INCH DIA. DUST REPOSITORY scientists and TEMPORARY SUMP- DRAIN PIPE (5FT. LONG) 9824 WRAPPED IN GEOTEXTILE engineers 9820. 4900 Pearl East Circle. Suite 300W. 20 40 60 80 100 120 140 160 180 200 220 240 260 Boulder. Colorado 80301 Phone (303) 447-1823 DISTANCE. FEET NOTE: Fox (303) 447-1836 1. DO NOT PLACE DEMOLFTION SECTION DEBRIS ABOVE FLUE DUST REPOSITORY. USE ONLY VERTICAL EXAGGERATION 20 Fra FINE-GRAINED NON-RESIDENTIAL SOIL, WATER-QUENCHED SLAG OR TAILING. 9860 9856 TOP OF CONSOLIDATED TAILING TOP OF FLUE DUST & NON-RESIDENTIAL SOILS REPOSITORY 9852 REFERENCE 9848 9844 9840 9836 9832 BOTTOM OF FLUE DUST- 9828 REPOSITORY 9824 9820. 20 40 60 80 100 120 140 160 180 200 DISTANCE. FEET

SECTION vancni. sou HOaZONW. SOU VERTICAL EXAGGERATION = 2x \ -

INSTALL VISUAL MARKER ABOVE 18 LAYER OF VEGETATED REPOSITORY COVER SOIL . 4-8 FT LAYER OF '..- . COMPACTED FINE-GRAINED .' NON-RESIDENTIAL AREA SOILS. 4-8 FT LAYER OF COMPACTED NON-RESIDENTIAL . . • . WATER-QUENCHED SLAG AREA SOIL AND TAILING (SEE SECTION A. NOTE 1) ' '-OR TAILING'. ' ". '•'.' «» ' a.'.i: :UJ a ^GEDTEXMLE-

COMPACTED FLUE DUST (DEPTH VARIES)

ASARCO, Incorporated

AV/CZL SITE - OU5 FLUE DUST REPOSITORY ANCHOR TRENCH DETAIL FLUE DUST NOT TO SCALE REPOSITORY PLAN FLUE DUST REPOSITORY SECTIONS AND SECTION DETAIL fC LEGEND: DETAILS MOT TO SCALE 5 ••••••«-• GEOMtMHRANt DRAWING KG. r-**'^^~4 NON-WOVEN GEOTEXTILE (12 oz/sy) 634451C-107

-• • •- VISIBLE MARKER SHEET OF 14 9860- 9860 RUN-OFF 9855- CONTROL -9855 BERM 9850- -9850

9845- 18" LAYER OF -9845 VEGETATED COVER SOIL 9840- RUE DUST -9840 REPOSITORY b COMPACTED u. 9835- NON-RESIDENTIAL -ANCHOR f 2 -9835 EXISTING AREA SOILS. TAILING TRENCH v z 9830- GROUND & DEMOLITION DEBRIS -9830 consulting c SURFACE scientists and 9825 2 A ANCHOR -9825 -"iotf TRENCH engineers I 9820- -9820 4900 Peort East Circle, Suite 300W. Boulder, Colorado 80301 DITCH 9815- -9815 Phone (303) 447-1823 Fax (303) 447-1836 9810 I I 9810 20 4O 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 DISTANCE. FEET SECTION f A

VERI1CM. SOUE HCRZOHUL SCM£

0 10 FEET 20 REFERENCE VERTICAL EXAGGERATION - 2x 9865 9865 9860- -9860 frit 3% MINI 9855- -9855 985O- -9850 9845- IB" LAYER OF COMPACTED -9845 VEGETATED NON- RESIDENTIAL 9840- COVER SOIL AREA SOILS. TAILING -9840 9835- A DEMOLITION DEBRIS -9835 9830- -9830 9825- -9825 9820- -9820 -RUN-OFF 9815- CONTROL DITCH -9815 9810 9810 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 REVISIONS

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vcnncN. sou HORZOHIM. auu 534451C-301 4 10 „ 14 PERIMETER BERM 9870 9870 OLD FOUNDATIONS TO 18" LAYER OF 9865- ^ 18- LAYER OF REMAIN IN PLACE' -9865 • VEGETATED if, COVER SOIL 9860- -9860 consulting REGRADED APPROXIMATE 9855- -9855 SURFACE EXCAVATED scientists and SURFACE 9850- engineers CONSOLIDATED -9850 NON-RESIDENTIAL 4900 Pearl East Circle. Suite 300W. AREA SOILS FROM 9845- -9845 Boulder. Colorado BO JO I EXISTING Phone (303) 447-1823 UPGRADIENT SLOPE CONSOLIDATED GROUND Fax (303) 447-1836 9840 NON-RESIDENTIAL SOIL -9840 ! SURFACE u 9835- -9835

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DRAWING NO. 1534451C-302 11 14 SHEET nr A 9B60 EXISTING GROUND SURFACE

36" HPDE CULVERT INLET BEGIN RUN-ON/RUN-OFF STA 9+70 INV. EL 9818.0 CONTROL CHANNEL STA 4+60 REGRADE SURFACE STA 0+00 INV. EL 9839.5 INV. EL 9849.5 consulting STA 5+75 INSTALL RIPRAP AT CULVERT INV. EL 9826.0 INLET AND Oim FT scientists and 9810 ~i r i T i i i i i i i i i i i i i i T i i i i i i T i i i i i i i i r i i i r i i i engineers 0 20 40 60 80 100 120 14O 160 1BO 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800 820 840 860 880 900 920 940 96O 980 4900 Pearl East Circle. Suite 300W. AV EAST Boulder, Colorado 80301 Phone (303) 447-1823 RUN-ON/RUN-OFF CONTROL HOnZOMM. SOU Fax (303) 447-1836 CHANNEL - PROFILE VERTICAL EXAGGERATION - 2x 20 FIET «

REFERENCE 9860 9860

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9810 9810 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800 820 840 860 880 900 920 940 960 980 1000

AV WEST RUN-ON/RUN-OFF CONTROL WTO* S0i£ CHANNEL - PROFILE (STA 0+00 - 10+00) » fttl 40 VERTICAL EXAGGERATION - 2x REVISIONS DATE ISSUE FOR REVIEW 7/04

9860 9860 DAYLIGHT CHANNEL TO EXISTING TOPOGRAPHY. 1% (MIN.) SLOPE- 9850- CULVERT OUTLET -9850 -PROFB.E STA 19+00 9840- CONTINUATION •NV. EL 9814.0 -9840 SHOWN ABOVE STA 13+50 -36'# HOPE CULVERT IN INV. EL 9821.5 -EXISTING GROUND SURFACE -9830 9830- STA 17+00 DESIGNED BT: INV. a 9818.0 PRAWN BT: SCO 9820- -9820 CHECKED BY: PEP APPROVED BT: 9810 CTB RLE: MFC-ST VIEW NAME: PLAN 1000 1020 1040 1060 1080 1100 1120 1140 1160 1180 1200 1220 1240 1260 1280 1300 1320 1340 1360 1380 1400 1420 1440 1460 1480 15OO 1520 1540 I960 1580 I6OO 1620 1640 1660 1680 1700 1720 1740 1760 1780 1800 1820 1840 1860 188I8600 19019800 20019200 ORIGINATION DATE: 01/01/04 PLOT SCALE: 1:1 OR 1:2 AV WEST DATE: JULY 2004 RUN-ON/RUN-OFJ^ CONTROL WTO*. S0t£ HOnZOHW. SOU NOTES: ASARCO, Incorporated _20' CHANNEL - PROFILE (STA 10+00 - 20+00) 20 FIET 40 1. STATIONS AND ELEVATIONS ARE APPROXIMATE AND AV/CZL SITE - OU5 MAY VARY IN THE FIELD FROM THOSE SHOWN. IF VERTICAL EXAGGERATION « 2x ^t-l° 36» HOPE RPE SLOPE > 2%. RIPRAP REQUIRED. RUN-ON/RUNOFF -12" RIPRAP 6oz/sy GEOTEXTILE 2. SEE DWG. 534451C-501 FOR CROSS SECTION DETAILS. CONTROL CHANNEL CULVERT OUTLET DETAIL PROFILES - AV SMELTER] NOT TO SCALE 3. 36"« HOPE CULVERT TO HAVE FLARED-END INLET AND OUTLET ALONG WTTri RIPRAP FOR EROSION DKAWINU MU. PROTECTION. 1' MIN. COVER. 534451C-303

SHEET *_~ OF 14 9890- 9890

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9850- r9850 DAYLIGHT CHANNEL TO EXISTING TOPOGRAPHY. -

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9850- I I I T -9850 I 3RAWNBT: SCO 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 CHECKED BY: PEP APPROVED BY: DLL CZL WEST VIEW NAME; PLAN RUN-ON/RUN-OFF CONTROL Verne*. SOME HOMZDNM. SCME ORIGINATION DATE: 01/01/04 CHANNEL - PROFILE /V 'LOT SCALE: 1:1 OR 1:: VERTICAL EXAGGERATION = 2x 10 FEET 3D )ATE: JULY 2004 *SARCO, Incoreporatec fr'e NOTES: J AV/CZL SITE - OU5 «»? i 1. STATIONS AND ELEVATIONS ARE APPROXIMATE AND MAY VARY IN THE FIELD FROM THOSE SHOWN. RUN-ON/RUN-OFF CZL EAST: IF SLOPE > 4%. RIPRAP REQUIRED. I X CZL WEST: IF SLOPE > 2%, RIPRAP REQUIRED. CONTROL CHANNEL 'ROF1LES AND DETAILSl 2. SEE DWG. 534451C-601 FOR CROSS SECTION DETAILS. - CZL MILL _0. "2 DRAWING NO. i S 15344510-304^

SHEET STEEL OR WOOD POST 36' HIGH (MAX.)

consulting scientists and PROVIDE 4" (MIN.) ANCHORAGE DEPTH engineers FOR SILT FENCE NON-WOVEN GEOTEXTILE 4900 Peart East Circle, Suile 300W, GEOTEXTILE Boulder, Colorado 80301 (8 oz/sy) PLACE 12" LAYER Phone (303) 447-1823 OF RIPRAP (MIN.) Fax (303) 447-1836 SILT FENCE DETAIL

36" HOPE PIPE SANDY-GRAVEL (EXTERNAL RIBS) PIPE BEDDING RUN-ON CONTROL DITCH - TYPICAL SECTION

REFERENCE

VARIES FROM 18" LAYER OF 3 TO 5 VEGETATED COVER SOIL

CONSOLIDATED NON-RESIDENTIAL AREA REVISIONS BY DATE SOILS. TAILING & DEMOLITION DEBRIS - ISSUE FOR REVIEW DLL 7/04

RUN-ON CONTROL DITCH RUN-OFF CONTROL BERM - TYPICAL SECTION - TYPICAL SECTION

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rtEW NAME: PLAN ORIGINATION DATE: 01/01/04 NON-WOVEN 'LOT SCALE: 1:1 OR 1:2 GEOTEXTILE DATE: JULY 2004 (8 oz/sy) PLACE 12" LAYER OF RIPRAP (MIN.) ASARCO, Incorporated H 18" LAYER OF COVER SOIL A NON-WOVEN AV/CZL SITE - OU5

00 VEGETATION GEOTEXTILE (8 oz/uy) RUN-ON/RUN-OFF CONTROL SECTIONS RUN-ON CONTROL DfTCH RUN-OFF CHUTE - TYPICAL SECTION TYPICAL SECTION AND MISCELLANEOUS DETAILS DRAWING NO. REV.NO. 534451C-501

SHEET L? OF !_T APPENDICES APPENDIX A

INVESTIGATION TO SUPPORT REMEDIAL DESIGN INVESTIGATION TO SUPPORT REMEDIAL DESIGN

ARKANSAS VALLEY SMELTER AND COLORADO ZINC-LEAD MILL SITE OPERABLE UNIT 5 (OU5) California Gulch Superfund Site

December 2003

Prepared for:

ASARCO Incorporated 495 East 51st Avenue Denver, CO 80216-2098

Prepared by: MFC, INC. 4900 Pearl East Circle, Suite 300W Boulder, CO 80301 (303)447-1823 Fax: (303)447-1836

MFG Project No. 5344.51 TABLE OF CONTENTS

LIST OF TABLES ii LIST OF FIGURES ii LIST OF ATTACHMENTS ii 1.0 'INTRODUCTION 1 2.0 BACKGROUND INFORMATION AND INVESTIGATION APPROACH 2 3.0 INVESTIGATION METHODS 4 1.0 Sampling Locations 4 1.0.0 Former Blast Furnace/Baghouse Area '. 4 2.0.0 Former Roasting Plant Area 4 2.0 Sample Collection and Handling 5 3.0 Analysis Methods 5 4.0 INVESTIGATION RESULTS:: 7 1.0 Blast Furnace Area 7 2.0 Former Roasting Plant Area 11 1.0 SUMMARY OF INVESTIGATION FINDINGS 16 1.0 INFORMATION TO SUPPORT REMEDIAL DESIGN : 17 1.0 REFERENCES '. 18

ASARCO Incorporated MFC, Inc. J:VBLDOI\5}44\3344-iO\AV_CZLDoign\Simplinglnveiiigilion\lnvesiigiiioiiRtpoR.doc J December 2003 LIST OF TABLES

Table 4-1. Arsenic and Lead Concentrations Measured Within the Baghouse Footprint (Test Pit 1) Table 4-2. Arsenic and Lead Concentrations Measured Adjacent to the Baghouse Footprint (Test Pit 2) Table 4-3. Arsenic and Lead Concentrations Measured in Surface Samples Within the Baghouse Footprint Table 4-4. Arsenic and Lead Concentrations Measured in Surface Samples Adjacent to the Baghouse Footprint Table 4-5. Arsenic and Lead Concentrations Measured in Surface Samples Within the Footprint of the Former Blast Furnace Flue Table 4-6. Arsenic and Lead Concentrations Measured in Surface Samples Within and Adjacent to the Former Blast Furnace Building Table 4-7. Arsenic and Lead Concentrations Measured Within the Footprint of a Former Flue in the Southern Portion of the Roasting Plant Area (Test Pit 3) Table 4-8. Arsenic and Lead Concentrations Measured in Surface Samples Within the Former Flue Footprints in the Southern Portion of the Former Roasting Plant Area Table 4-9. Arsenic and Lead Concentrations Measured in Surface Samples Outside Flue Footprints in the Southern Portion of the Former Roasting Plant Area Table 4-10. Arsenic and Lead Concentrations Measured Within the Footprint of a Former Roasting Plant Area - Flue to the North of the Existing Concrete Arch (Test Pit 4) Table 4-11. Arsenic and Lead Concentrations Measured Within the Footprint of a Former Roasting Plant Area - Flue between the Cottrell Plant and Smoke Stack (Test Pit 5) Table 4-12. Arsenic and Lead Concentrations Measured in Surface Samples Outside Flue Footprints in the Northern Portion of the Former Roasting Plant Area Table 4-13. Arsenic and Lead Concentrations Measured in Surface Samples Outside Flue Footprints in the Northern Portion of the Former Roasting Plant Area

LIST OF FIGURES

Figure 4-1. Sampling Locations and Proposed Flue Dust Removal Area - Blast Furnace/Baghouse Area Figure 4-2. Sampling Locations and Proposed Flue Dust Removal Area - Roasting Plant Area

LIST OF ATTACHMENTS

Attachment A Investigation Photographs Attachment B Laboratory Analytical Reports

ASARCO Incorporated MFC, Inc. J:\BLD01V5344\5344.JOVAV_CZL DeiigiASimpting InvtsiigllionUnvcnigiiiiHi Rqwrt.doc December 2003 1.0 INTRODUCTION

This report provides the findings of a sampling and analysis investigation to support remedial design at the Arkansas Valley (AV) Smelter/Colorado Zinc-Lead (CZL) Mill site. These two areas (the AV/CZL site) comprise a portion of Operable Unit 5 (OU5) at the California Gulch Superfund Site located in Leadville, Colorado. i

The investigation was performed in March 2001 in accordance with the approach and procedures set out in the Sampling and Analysis Plan (SAP) (MFG, 2001). As described in the SAP, the investigation was intended to identify the nature and extent of flue dust at the AV Smelter site. Additional information was required for the flue dust component of the remediation, because a relatively accurate estimate of flue dust volume is necessary to correctly locate and size the on-site repository in design. The data generated by this investigation have been used to support remedial design, in particular details of the areas and initial depths for flue dust excavations and this report is included as an Appendix to the Remedial Design Report (RDR). The design also includes sampling and analysis requirements to confirm that flue dust has been excavated from target areas during the remedial action construction (see the Quality Assurance Plan - Appendix E to the RDR). Because the remedial action construction will include sampling to confirm flue dust has been removed, a comprehensive investigation was not required to support design.

ASARCO Incorporated MFG, Inc. J:\BLDOI\S344\5M4-5aVAV_CZLDcsigii\Sunplingltivniigiiion\lnvcitigition Repon.doc 1 December 2003 2.0 BACKGROUND INFORMATION AND INVESTIGATION APPROACH

As discussed in the Focused Feasibility Study (FFS: MFG, 2000a), the AV Smelter was the longest operating smelter in the Leadville area, processing lead ores and reprocessing slag to produce lead, silver and other metals. The plant was built in 1879 and was in operation until 1961. In 1897, the AV Smelter was the only lead blast smelter operating in Leadville. By 1915 many improvements had been made and 10 blast furnaces for smelting operated steadily throughout the year producing lead bullion and copper matte. Subsequently, the production of the AV Smelter decreased in response to decreased production from Leadville District mines. In the 1920s through the 1950s the smelter continued working, but rarely with more than one furnace in blast. Much of the operation during this period was reworking old slag dumps of the Leadville District and reducing small quantities of ore mined in the Central Rockies (Jacobs, 1991).

After operations ceased, the smelter was partially demolished and equipment and other salvageable materials taken offsite. In addition, the new owner scraped most of the residual smelter process materials from the site and transported them offsite for resmelting. A few smelter structures are still present at the site today. The layout of the former smelter structures can be identified from a 1937 Sanbom fire- insurance map, which provides a detailed record of locations of former smelter operations and facilities. Features on the 1937 map correspond well with the remaining identifiable features verifying the accuracy of the developed historical smelter layout:

Roasting and blast furnace operations performed during smelting had a tendency to volatilize various metals, which were vented in offgases and rapidly condensed onto fine particles called "flue dust." Offgases from the blast and roasting furnaces were conveyed in flues (essentially above-ground tunnels usually made of brick) to treatment units (the Cottrell Plant or the baghouse), where the flue dust was collected. Exit gases from these treatment units were sent to the smoke stacks. Collected flue dust was typically recycled to the blast furnace for metals recovery. Investigations of similar smelters (in particular the Everett Washington Smelter which operated from 1892 to 1914, and the Murray Utah Smelter which operated from 1902 to 1949 using very similar technology as the AV Smelter), found that flue dust residues from roasting and blast furnace operations were similar in terms of properties relevant to environmental remediation, such as metals levels and leaching potential. A single sample of blast furnace flue dust was collected at the AV Smelter during the site characterization effort and found to contain 149,000 mg/Kg arsenic and 272,000 mg/Kg lead. Consistent with those findings, flue dust was found to

ASARCO Incorporated MFG, Inc. J:\BLDOI\J344W344-50UV_CZLDMign\Simplinglnvt5tiguion\lnvMlt5ltbnRcpon.4x 2 December 2003 have much higher leaching potential for metals than other residual smelter-related materials (such as ore, matte, concentrates and slag).

Preliminary identification of the location and volume of flue dust was provided in the FFS for use in identification and evaluation of remedial alternatives. Information used in that identification included:

• The available sampling data; • Knowledge of the smelter operational areas where the materials were handled, processed, stored, or transported; and • Visual observations of the site conditions.

Areas where flue dust was considered likely to be present were in the general vicinity of the former flues and baghouse connected to the blast furnace and the flues and dust collection unit (Cottrell Plant) connected to the roasting plant. These were the principal areas where flue dust was generated, conveyed, and handled during smelter operation. The investigation focused on those areas.

ASARCO Incorporated MFC, Inc. ):\BLDOI\5}44\5344.SO\AV_CZLOeiign\SimplingInv«liguion\lnvMligllionRepon.doc 3 December 2003 3.0 INVESTIGATION METHODS

This section provides details of the sample location selection, and sample collection, preparation and analysis techniques.

3.1 Sampling Locations

Proposed sampling locations were set out in the SAP. The investigation was performed in March 2001, when much of the site was covered by snow, making access to some areas more difficult. In addition, some difficulties were encountered in the collection of some of the surface samples due to the frozen ground. However, as discussed below sufficient samples were collected to meet the primary goals of the investigation.

3.1.1 Former Blast Furnace/Baghouse Area

Samples were collected within the footprint and debris pile of the former baghouse, in the footprint of the flB former flue from the blast furnace to the baghouse, and in adjacent areas. The locations where samples were collected are shown on Figure 4-1 and photographs of the locations are provided in Attachment A. A total of 32 samples were collected from this area (22 from within the blast furnace flue and baghouse footprints and 10 from the immediately surrounding area).

Surface samples were collected from approximately the 0 to 4 inch depth interval and targeted fine- grained materials. In addition, subsurface samples were collected from two locations within the baghouse footprint. At each location a test pit was excavated by backhoe through the baghouse debris pile to a depth of approximately 5 feet and samples collected at one-foot depth intervals.

3.1.2 Former Roasting Plant Area

Samples were collected from within the footprints of the former roasting plant flues and in adjacent areas. The locations where samples were collected are shown on Figure 2 and photographs of the sampling locations are shown in Attachment A. A total of 50 samples were collected from the former roasting

ASARCO Incorporated MFC, Inc. J:\BUX)l\3344\5M4-5(AAV_CZLDMign\Simplinglnvesiig«iionynvesii8iiioi)Repon.doe 4 December 2003 plant area; 26 from within the flue footprints, and 24 from the immediately surrounding areas, including the roasting plant building footprint.

Surface samples were collected from approximately the 0 to 4 inch depth interval and targeted fine- grained materials. In addition, subsurface samples were collected from three locations within the flue footprints. At each location a test pit was excavated by backhoe within the flue footprint to depths of approximately 5, 2, and 3 feet at AVTP03, AVTP04 and AVTP05, respectively. Samples were collected at one-foot depth intervals from each test pit. The SAP targeted a fourth area for subsurface sampling: within the flue footprint adjacent to the ore bins. However, it was found that this entire ar.ea was covered by a concrete slab and therefore no samples were collected.

3.2 Sample Collection and Handling

Soil samples were collected directly from the ground surface and from the sidewalls of excavated trenches using methods presented in MFG Standard Operating Procedure (SOP) No. 9, Soil and Sediment Sampling for Chemical Analysis, which was provided in the SAP. The field sampler preferentially collected the fine-grained materials at each sample location. Ground surface samples were collected from the top 4 inches. Test pit wall samples were collected by scraping approximately 2 inches of soil from a rectangular area approximately 6 inches long by 4 inches wide along the trench wall. The depth of trench-wall samples was measured from the ground surface to the center of this sample area and recorded with other sample information.

Soil samples were placed in Zip-Lock bags, labeled with the relevant information and taken to the Asarco Information Center in Leadvilie for preparation. Each sample was air dried and thoroughly homogenized by manually mixing within the sample bag. The sealed bag was turned end over end and any large clumps of soil broken up by hand for a period of at least 2 minutes. The samples were then sieved by number 10-sieve (less than 2 mm size fraction) and shipped to Asarco's Technical Services Center in Salt Lake City for analysis of arsenic and lead.

3.3 Analysis Methods

The samples were analyzed by the Inductively Coupled Plasma (ICP) method in accordance with the Environmental Protection Agency (EPA) Method 6010. This method is capable of providing quantitative

ASARCO Incorporated MFG, Inc. J:\BLDOl\5344\5344-SO\AV_CZL DdigMSimpling InvtuigiiionVInveuiguion Repon.doc 5 December 2003 data for the range of arsenic concentrations from approximately 5 mg/Kg to over 100,000 mg/Kg. These limits are sufficient to provide data that meets the data quality objectives presented in the SAP.

The SAP originally provided on-site X-Ray Fluorescence as the method of analysis, however as the investigation proceeded, site conditions were encountered that decreased the accuracy of the XRF calibration. Therefore, to provide data of sufficient quality to support remedial design, all samples were submitted for ICP analysis.

ASARCO Incorporated MFC, Inc. J:\BLD01\i344\J344-5IAAV_CZLDc5isn\S.mplmslnvMtigjlion\lnveslisJlionRepon.cloc 6 December 2003 4.0 INVESTIGATION RESULTS

This section describes the analytical results generated during the investigation. As shown, the primary characteristic that distinguishes flue dust from other residual smelter materials is the concentration of arsenic.

4.1 Blast Furnace Area

During smelter operations, flue dust was generated in the blast furnace smelting operations and conveyed in offgases via an above-ground flue to the baghouse. The baghouse filtered out much of the flue dust, which was typically mixed with lime and recycled to the blast furnace. Offgases from the baghouse were emitted to the atmosphere. Currently, much of the lower level of the blast furnace building is relatively intact. Although the furnaces and associated equipment have mostly been removed, there are numerous piles of residual smelter materials and demolition debris throughout the area. The former flue structure is present on the north side of the blast furnace building and runs outside the building towards the baghouse. The foundation and back wall of the former flue are intact. The baghouse has been demolished and demolition debris remains in the area. The rubble pile consists primarily of bricks mixed with finer grained materials.

The primary focus of the investigation in the blast furnace area was on fine-grained materials mixed with the debris associated with the former baghouse and on materials within and adjacent to the footprint of the former flue from the blast furnaces to the baghouse. Locations where samples were collected are shown on Figure 4-1.

Two test pits were excavated within the footprint of the former baghouse. Test Pit 1 (AVTP01) was excavated into the southern edge of the baghouse debris pile adjacent to an existing concrete wall associated with the former baghouse structure. The pit was excavated to a depth of just over four feet. The material encountered consisted of general brick rubble intermixed with fine-grained material. No obvious intact structures or foundations were identified in the test pit. Fine-grained slag was encountered at a depth of approximately 4 feet, which appeared to indicate that either the baghouse had been constructed on top of the existing slag pile or that slag had been used as base material in construction of the baghouse. This provided a distinctive visual indicator of where the demolition debris material ended.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5344-50\AV_CZL D«ign\Simpling InvatigilionUnmtigition Rtpon.doc 7 December 2003 Arsenic and lead concentrations measured in collected samples are shown in Table 4-1. As shown, arsenic concentrations in the fine-grained material are relatively constant with depth.

Table 4-1 Arsenic and Lead Concentrations Measured Within the Baghouse Footprint (Test Pit 1)

Sample ID Sample Material Description Arsenic Lead Depth [feet] Concentration Concentration [mg/Kgl [mg/Kel AVTP01-1 0-1 Soil/ demolition debris 3,048 4,212 AVTP01-2 1-2 Soil/ demolition debris 3,568 6,868 AVTP01-3 2-3 Soil/ demolition debris 3,677 5,867 AVTP01-4 3-4 Soil/ demolition debris 3,751 6,414 AVTP01-5 4-5 Slag 3,437 22,590

Test pit 2 (AVTP02) was excavated in the northern portion of the baghouse debris pile (Figure 4-1). At this location, the debris was of similar appearance to the material encountered at Test Pit 1. However, a concrete floor/foundation was encountered at five feet, which prevented deeper excavation. Measured arsenic and lead concentrations are shown in Table 4-2.

Table 4-2 Arsenic and Lead Concentrations Measured Adjacent to the Baghouse Footprint (Test Pit 2)

Sample ID Sample Material Description Arsenic Lead Depth [feet] Concentration Concentration [me/Kg] [ms/Kel AVTP02-1 0-1 Soil/ demolition debris 7,444 7,920 AVTP02-2 1-2 Soil/ demolition debris 8,262 8,976 AVTP02-3 2-3 Soil/ demolition debris 3,315 9,633 AVTP02-4 3-4 Soil/ demolition debris 2,267 10,050 AVTP02-5 4-5 Soil/ demolition debris underlain by 3,162 10,080 concrete

ASARCO Incorporated MFC, Inc. J:\BLDOI\53W\5J44-50\AV_CZL DaigjASunpling InvenigilionUnvaiiguion ReporUoc December 2003 In addition, four surface samples were collected from within the baghouse footprint (Figure 4-1). Measured arsenic and lead concentrations in these surface samples are shown in Table 4-3. The two samples with arsenic concentrations above 10,000 mg/Kg are from the northern portion of the baghouse, adjacent to the existing flue structure, and in the debris pile to the north.

Table 4-3 Arsenic and Lead Concentrations Measured in Surface Samples Within the Baghouse Footprint

Sample ID Material Description Arsenic Lead Concentration Concentration fmg/Kgl fmg/Kgl AVS001 Soil/ demolition debris 12,930 11,030 AVS002 Soil/ demolition debris 3,737 14,510 AVS038 Slag . 569 10,310 AVS041 Soil 62,000 42,230

Nine surface samples were collected in the areas surrounding the former baghouse footprint (Figure 4-1). Measured arsenic and lead concentrations in these surface samples are shown in Table 4-4. As shown, arsenic concentrations are generally lower than measured within the baghouse footprint. The exception is sample AVS037 which was collected from the debris pile to the northwest of the Baghouse.

Table 4-4 Arsenic and Lead Concentrations Measured in Surface Samples Adjacent to the Baghouse Footprint

Sample ID Material Description Arsenic Lead Concentration Concentration [me/Kg] frag/Kg] AVS035 Soil/ demolition debris 760 7,579 AVS036 Slag 2,115 21,370 AVS037 Soil/ demolition debris 10,480 11,540 AVS039 Slag 567 10,320 AVS040 Soil/ demolition debris 3,378 46,590 AVS042 Soil/ demolition debris 7,146 5,450 AVS044 Soil 2,393 10,690 AVS045 Soil 18 151 AVS046 Soil 1,068 16,110

ASARCO Incorporated MFC, Inc. J:\BLDOI\33M\J344-50\AV_CZL DaignVSimpling InvatiguionVInveuigiiion Rcport.doc December 2003 The former blast furnace building is partially demolished. The furnaces and other equipment have been removed. The remnant of the flue that carried offgases to the baghouse is present at the north end of the blast furnace building. Within and around the blast furnace there are various piles of fine-grained and other materials. Four surface samples were collected from within or immediately adjacent to the footprint of the former flue (Figure 4-1). The measured arsenic and lead concentrations are shown in Table 4-5. As shown, the arsenic concentrations are relatively low and do hot indicate the presence of flue dust in this structure.

Table 4-5 Arsenic and Lead Concentrations Measured in Surface Samples Within the Footprint of the Former Blast Furnace Flue

Sample ID Material Description Arsenic Lead Concentration Concentration [rog/Kgl [me/Kg] AVS043 Soil/ demolition debris 1,472 22,790 AVS049 Soil/ demolition debris 2,458 36,860 AVS052 Soil/ demolition debris 2,938 4,797 AVS054 Soil/ demolition debris 4,394 15,280

Five surface samples were collected in and around the blast furnace building. The measured arsenic and lead concentrations are shown in Table 4-6. As shown, the arsenic concentrations are relatively low and do not indicate the presence of flue dust in these areas.

Table 4-6 Arsenic and Lead Concentrations Measured in Surface Samples Within and Adjacent to the Former Blast Furnace Building

Sample ID Material Description Arsenic Lead Concentration Concentration fmg/Kel [me/Kgl AVS047 Soil 117 1,638 AVS048 Soil/ demolition debris 3,839 28,120 AVS050 Soil/ demolition debris 1,667 16,380 AVS051 Soil/ demolition debris 556 60,870 AVS053 Soil/ demolition debris 2,841 18,220

ASARCO Incorporated MFG. Inc. J:\BLDOI\M44\5344-50VAV_CZL DetigtASimpling lnvtsliguionMnvciligalil>nRcpan.doc 10 December 2003 4.2 Former Roasting Plant Area

During smelter operations, flue dust was generated by the roasting operations and conveyed in offgases via an above-ground flue to an electrostatic precipitator (Cottrell Plant). The Cottrell Plant precipitated out much of the flue dust, which was typically recycled to the process. Offgases from the Cottrell Plant were emitted to the atmosphere via the adjacent smoke stack. Currently, the flue area contains piles of debris from demolition of the structures. The footprints of the former flues are visible in most areas. The base of the former smoke stack immediately to the north of the former roasting area is intact. The debris from demolition of the smoke stack adjacent to the former Cottrell Plant is laying on the ground surface. All equipment and structures in the sulfide roaster building area have been removed and the area appears to have been scraped to provide a relatively flat surface.

For sampling and discussion purposes, the former roasting plant area has been subdivided into two areas. One area is located south of the concrete arch, and the other area is located north of the concrete arch.

In the southern area, Test Pit 3 (AVTP03) was excavated through the footprint of a former flue. The test pit found conditions similar to those that have been found at other smelters: the brick floor of the flue was t intact, approximately one foot below current ground surface, with a layer of flue dust above it. The flue dust had a burnt appearance and gave off a sulfurous odor. Below the floor was native soil. Photographs of the test pit are shown in Attachment A. Arsenic and lead concentrations measured in collected samples are shown in Table 4-7. The results show that the arsenic concentration in the residual roasting plant flue dust is of the order of 20,000 mg/Kg and attenuates with depth.

Table 4-7 Arsenic and Lead Concentrations Measured Within the Footprint of a Former Flue in the Southern Portion of the Roasting Plant Area (Test Pit 3)

Sample ID Sample Material Description Arsenic Lead Depth [feet] Concentration Concentration [me/Kg] frag/Kg] AVTP03-1 0-1 Residual fine-grained smelter 19,900 6,922 material. AVTP03-2 1-2 Native soil. 6,569 636 AVTP03-3 2-3 Native soil. 4,273 871 AVTP03-4 3-4 Native soil. 2,713 472 AVTP03-5 4-5 Native Soil 2,341 473

ASARCO Incorporated MFC, Inc. J:\BLDOI\S344\SJ44-50\AV_CZL DaignVSimpling InvcuigalionUnvniiguion Rcpon.doc 11 December 2003 In addition to the test pit, 10 surface samples were also collected from within or in the immediate vicinity of the flue footprints in the southern portion of the former roasting plant area (Figure 4-2). The arsenic and lead concentrations measured in these samples are shown in Table 4-8. As shown, the arsenic concentrations are lower than found in the flue dust identified in Test Pit 3. Also the lead concentrations are much higher than the arsenic concentrations, indicating a different source of metals than flue dust.

Table 4-8 Arsenic and Lead Concentrations Measured in Surface Samples Within the Former Flue Footprints in the Southern Portion of the Former Roasting Plant Area

Sample ID Material Description Arsenic Lead Concentration Concentration [mg/Kgl fmg/Ksl AVS020 Soil 2,607 19,960 AVS021 Soil 8,818 10,660 AVS024 Soil 2,673 23,120 AVS025 Soil 812 15,300 AVS028 Soil 2,520 27,160 AVS030 Soil 963 8,158 AVS057 Soil 7,446 11,430 AVS058 Soil 7,843 20,310 AVS060 Soil 4,205 12,410 AVS061 Soil 1,765 5,988

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZ1. Design\Sunpling InvntigitionMnvesijuion Repoddoc 12 December 2003 In addition, 13 surface samples were collected in the southern portion of the former roasting plant area t outside the footprints of former flues (Figure 4-2). The arsenic and lead concentrations measured in these samples are shown in Table 4-9. The presence of flue dust is not indicated at the sample locations with the exception of AVS027 and AVS059. Location AVS027 is within 10 feet of the former flue footprint and inspection of this area revealed that flue dust had been graded from the flue into the adjacent area. Location AVS059 is more distant from the former flue footprints and is likely the result of grading of .flue dust materials after the roasting plant structures were demolished. Sampling was not sufficient to identify the lateral extent of flue dust in this area.

Table 4-9 Arsenic and Lead Concentrations Measured in Surface Samples Outside Flue Footprints in the Southern Portion of the Former Roasting Plant Area

Sample ID Material Description Arsenic Lead Concentration Concentration fmg/Kgl fme/Kel AVS017 Soil 1,481 11,990 AVS018 Soil 3,601 16,070 AVS019 Soil 4,301 14,500 AVS022 Soil 2,229 10,650 AVS023 Soil 307 6,202 AVS026 . Soil 151 2,164 AVS027 Soil 15,040 16,900 AVS029 Soil 3,464 44,010 AVS032 Soil 670 4,324 AVS033 Soil 1,148 8,107 AVS034 Soil 2,128 22,730 AVS059 Soil 38,650 28,670 AVS063 Soil 2,148 5,918

ASARCO Incorporated MFC, Inc. J:\BLD01\S344\5344-50\AV_CZL DnignVSunpling InvuligllionVlnveuigltion Rcpoit.doc 13 December 2003 Two test pits were excavated in the northern portion of the roasting plant area (where the former flue, Cottrell Plant and smoke stack were located; north of the existing concrete arch). Test Pit 4 (AVTP04) was excavated through the footprint of the former flue near the existing concrete arch (Figure 4-2). A large concrete foundation was encountered at approximately 2 feet depth, which prevented deeper excavation. The arsenic and lead concentrations measured at this location are shown in Table 4-10. The arsenic concentrations and observation of the test pit indicates tlVat flue dust is not present within the flue footprint.

Table 4-10 Arsenic and Lead Concentrations Measured Within the Footprint of a Former Roasting Plant Area - Flue to the North of the Existing Concrete Arch (Test Pit 4)

Sample ED Sample Depth Material Description Arsenic Lead [feet] Concentration Concentration fmg/Kgl [nig/Kg] AVTP04-1 0-1 Soil/ demolition debris 1,501 24,280 AVTP04-2 1-2 Soil/ demolition debris 1,402 27,930

The final test pit (Test Pit 5 or AVTP05) was excavated through the footprint of the former flue between the Cottrell Plant and the smoke stack (Figure 4-2). The excavation found a considerable amount of structural debris (including brick, wood, rebar and electrical cables) above a concrete foundation at approximately 3 feet below grade. The arsenic and lead concentrations measured in samples collected at this location are shown in Table 4-11. The arsenic concentrations and observation of the test pit indicates that flue dust is not present within the flue footprint. The relatively high lead concentrations indicate a different source of metals to these materials.

Table 4-11 Arsenic and Lead Concentrations Measured Within the Footprint of a Former Roasting Plant Area - Flue Between the Cottrell Plant and Smoke Stack (Test Pit 5)

Sample ID Sample Depth Material Description Arsenic Lead [feet] Concentration Concentration [rag/Kg] [rag/Kg] AVTP05-1 0-1 Soil/ demolition debris 1,894 15,640 AVTP05-2 1-2 Soil/ demolition debris 2,687 44,330 AVTP05-3 2-3 Soil/ demolition debris 7,003 63,450

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL DaignVStmpling InvHtigunnMnvtitiguion Repon.doc 14 December 2003 In addition, 9 surface samples were collected from the northern area within or in the immediate vicinity of the footprint of the former flue and Cottrell Plant (Figure 4-2). The measured arsenic and lead concentrations are shown in Table 4-12. The measured arsenic concentrations and relatively high lead concentrations indicate that flue dust is not present in this area.

Table 4-12 Arsenic and Lead Concentrations Measured in Surface Samples Outside Flue Footprints in the Northern Portion of the Former Roasting Plant Area

Sample ID Material Description Arsenic Lead Concentration Concentration fmg/Kgl [me/Kel AVS003 Soil/ demolition debris 202 866 AVS005 Soil/ demolition debris 2,107 28,900 AVS006 Soil/ demolition debris 774 7,993 AVS009 Soil/ demolition debris 2,156 21,200 AVS010 Soil/ demolition debris 1,699 23,780 AVS012 Soil/ demolition debris 1,782 16,350 AVS013 Soil/ demolition debris 1,116 15,650 AVS014 Soil/ demolition debris 971 28,610 AVS055 Soil/ demolition debris 7,566 10,800

Seven surface samples were collected from areas outside the footprint of the former flue and Cottrell Plant in the northern roasting plant area (Figure 4-2). The measured arsenic and lead concentrations are shown in Table 4-13. The measured arsenic concentrations and relatively high lead concentrations indicate that flue dust is not present in this area.

Table 4-13 Arsenic and Lead Concentrations Measured in Surface Samples Outside Flue Footprints in the Northern Portion of the Former Roasting Plant Area

Sample ID Material Description Arsenic Lead Concentration Concentration fmg/Kcl fme/Kel AVS004 Soil 1,936 • 14,010 AVS007 Soil 2,413 34,950 AVS008 Soil 5,493 59,400 AVS011 Soil 481 23,200 AVS015 SoU' 3,333 39,040 AVS016 Soil 440 4,562 AVS056 Soil 1,227 10,170

ASARCO Incorporated MFG. Inc. J:\BLDOI\S344\S344-30\AV_CZL De»ign\SimpIing InvttiigiibnUnvtstigition Repon.doc 15 December 2003 5.0 SUMMARY OF INVESTIGATION FINDINGS

As demonstrated by this investigation, flue dust is chemically distinct from other residual smelter materials at the site. The principal distinguishing characteristic is that arsenic concentrations are higher in flue dust than found in other materials. Also, arsenic concentrations are relatively higher compared to lead concentrations in flue dust than typically found in other smelter residual materials.

A key finding of the investigation is that large quantities of high-arsenic flue dust is not present at the site. A single sample of flue dust was collected during the site characterization effort and found to contain 149,000 mg/Kg arsenic. The highest arsenic concentration measured during the investigation to support remedial design was 62,000 mg/Kg, in the area immediately adjacent to the flue dust material identified previously.

Flue dust appears to be mixed with demolition debris and other materials in debris associated with the former baghouse. In addition, there are piles of fine-grained materials in the blast furnace building and in the area between the blast furnace building and baghouse that have the potential to contain flue dust. Although concentrations in some of the piles measured during this investigation were relatively low, arsenic concentrations as high as 15,000 mg/Kg were measured in calibration samples collected immediately prior to the investigation.

In the southern portion of the former roasting plant area, a test pit was excavated through the former flue footprint The test pit identified the flue walls and floor and a layer of residual flue dust approximately one foot thick. The flue dust had a burnt appearance and gave off a strong sulfurous smell. The arsenic concentration in the residual roasting plant flue dust was measured at around 20,000 mg/Kg. In addition, flue dust was identified adjacent to a flue footprint next to the ore bins and in an open area south of the roasting plant flues. Flue dust was not identified in the northern portion of the roasting plant area.

ASARCO Incorporated MFC, Inc. J:\BLOOI\5M4\5344-SIKAV.CZLDeiign\SamprmgInvestigilion\lnvesligilnnRefion.dDC 16 December 2003 6.0 INFORMATION TO SUPPORT REMEDIAL DESIGN

Based on the findings of the investigation, the following remedial design details have been developed:

• Flue dust is present mixed with demolition debris and other materials in the footprint of the former baghouse and in the area immediately t adjacent to the northwest. While concentrations of arsenic in the southern portion of the debris pile were relatively low, this area will be included in the flue dust excavations to provide a conservative approach. • Flue dust may be present in some of the piles of fine-grained materials in the blast furnace and in the adjacent area next to the baghouse. These piles will be classified as flue dust for purposes of the remediation. • Flue dust is present within the footprint of the flues in the southern portion of the former roasting plant area (south of the Dewey Arch) and in an immediately adjacent area next to the eastern ore bin. • Flue dust is present in an open area in the southern portion of the former roasting plant area. Samples were not collected in areas to the south and east of this location and therefore the investigation was not sufficient to delineate the lateral extent of flue dust in this area. • Arsenic concentrations in flue dust in the blast furnace area ranged up to 149,000 mg/Kg. Arsenic concentrations in the former roasting plant area were in the range of 20,000 to 40,000 mg/Kg. Based on these levels, an arsenic concentration to confirm that flue dust has been removed was established at 10,000 mg/Kg.

Proposed flue dust removal areas for the former Blast Fumace/Baghouse area and the former Roasting Plant Area are shown on figures 4-1 and 4-2, respectively.

ASARCO Incorporated MFG. Inc. J:\BLDOI\3344\JM4-50\AV_CZL DnignVSimpling InveiligitionMnvuliguion Repon.fec 17 December 2003 7.0 REFERENCES

Jacobs Engineering Group, 1991. Historical Mineral Processing Operations of the Leadville Mining District. May 1991.

MFG, Inc., 2000a. Final Focused Feasibility Study, Operable Unit 5, Arkansas Valley Smelter and Colorado Lead-Zinc Mill Site, California Gulch Superfund Site. Prepared for Asarco.

MFG, Inc., 2000b. Sampling and Analysis Plan to Support Remedial Design, Operable Unit 5, Arkansas Valley Smelter/Colorado Zinc-Lead Mill Site, California Gulch Superfund Site. December 28, 2000.

U.S. Environmental Protection Agency (EPA), 1994. USEPA Contract Laboratory Program National Functional Guidelines for Inorganic Data Review. Office of Solid Waste and Emergency Response. February.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-SO\AV_CZL Defignttimpling InvaiigukniMnvcstigition Repon.doc 18 December 2003 FIGURES FOOTP.Rljyi

LEGEND: AVS047, ASARCO CONFIGURATION OF SMELTER OPERATIONS IN ACTUAL SAMPLE LOCATIONS W/IDENTIFIER AV/CZL SfTE (OU5) - CALIFORNIA GULCH 1937 FROM SANBORN FIRE INSURANCE MAPS. FIGURE 4-1 REMAINING SITE FEATURES IDENTIFIED BY SAMPLING LOCATIONS AND PROPOSED SURVEY, 1998. FLUE DUST REMOVAL AREA - BLAST

PROPOSED FLUE DUST REMOVAL AREA FURNACE/BAGHOUSE AREA PROJECT: 010179.3 DATE: JULY 2004 REV: BY: SCG| CHECKED: ACK 160 FEET MFG. Inc. consulting scientists and engineers FOOTPRINT OF FORMER FLUE

FOOTPRINT "FORMER FL ?

( i 4. — T- — —

n ^-i CONCRETE WALL

LEGEND: AVS029 ~~ASARCO CONRGURATION OF SMELTER OPERATIONS IN ACTUAL SAMPLE LOCATIONS W/IDENTIFIER AV/CZL SITE (OU5) - CALIFORNIA GULCH 1937 FROM SANBORN FIRE INSURANCE MAPS. FIGURE 4-2 REMAINING SITE FEATURES IDENTIFIED BY SAMPLJNG LOCATIONS AND SURVEY, 1998. PROPOSED FLUE DUST REMOVAL PROPOSED FLUE DUST REMOVAL AREA AREAS - ROASTING PLANT AREA SCALE PROJECT: 010179.3 DATE: JULY 2004 REV: BY: SCG| CHECKED: ACK

100 100 FEET MFC, Inc. consulting scientists and engineers ATTACHMENTS ATTACHMENT A

INVESTIGATION PHOTOGRAPHS Color Photo(s)

The following pages contain color that does not appear in the scanned images.

To view the actual images, please contact the Superfund Records Center at (303) 312-6473. AVS001 - Looking SE across the Blast Furnace/Baghouse rubble from the west end of the site. Yellow flag marks the sample location.

AVS002 - Looking SE across the Blast Furnace/Baghouse rubble from the west end of the site. AVS003 - Looking south into the rubble in the Roasting Plant area.

AVS004 - Looking west across the rubble in the Roasting Plant area. AVS005 - Looking south across the stack rubble on the west side of the Roasting Plant area.

AVS006 - Looking south across the stack rubble in the Roasting Plant area. AVS007 - Looking north across the Roasting Plant area from the south.

AVS008 - Looking north across the Roasting Plant area. AVS009 - Looking north across the rubble in the Roasting Plant area.

AVS010 - Looking west across the Roasting Plant area. AVS011 - Looking west across the Roasting Plant area.

AVS012 - Looking south into standing structure on Roasting Plant area. AVS013 - Looking northwest across the rubble in the Roasting Plant area.

\ AVS014 - Looking west across the Roasting Plant area. AVS015 - Looking east across Roasting Plant area, Test Pit #4 is on the left.

AVS016 and AVSTP04 - Looking south across the Roasting Plant area, Test Pit #4 in foreground. AVS017 - Looking west across the Roasting Plant area.

AVS019, AVS020, and AVS021 - Looking northwest across the Roasting Plant area *******

AVS022 - Looking west across the Roasting Plant area

AVS024 - Looking west across the Roasting Plant area, into the ore bins.

10 aeaea

t AVS025 and AVS023 - Concrete arch, looking north across the Roasting Plant area.

AVS026 - Looking northwest across the Roasting Plant area.

11 Mill I ] - Mill III

AVS028 - Ore bins, looking northwest across the Roasting Plant area.

AVS029 - Ore bins, looking northwest across the Roasting Plant area from the south.

12 AVS032 and AVS030 - Looking north across the Roasting Plant area from the south side.

AVS033 and AVS027 - Looking west across the Roasting Plant area

13 niiiifl

AVS034 - Ore bins and concrete arch, looking north across the Roasting Plant area.

AVS035 - Looking east across the Blast Furnace/Baghouse area from the west side.

14 AVS036 - Looking east across the Blast Furnace'Baghouse area from the west side.

AVS037 - Looking SE across the site from the west end of the site. Test Pit #1 in the foreground.

15 AVS038 - Looking East across Blast Furnace/Baghouse area from the west end of the site.

AVS039 - Looking northeast across the Blast Furnace/Baghouse area.

16 AVS040 - Looking south across the Blast Furnace/Baghouse area from the north.

AVS041 - Looking south across intact flue. Sample location is in the lower right hand side of the picture.

17 AVS042 - Looking west across the Blast Furnace/Baghouse area from the north.

AVS043 - Looking west across the Blast Furnace/Baghouse area.

18 AVS044 - Looking north across the Blast Furnace/Baghouse area.

AVS045 - Looking north across the Blast Furnace/Baghouse area.

19 AVS046 - Looking northwest across the Blast Furnace/Baghouse an

AVS047 - Looking west across the Blast [ iirnace Baghouse area.

20 AVS048 - Looking east into the standing blast furnace structures.

AVS049 - Looking north across the north side of the Blast Furnace/Baghouse area.

21 AVS050 - Looking east across the Blast Furnace Baszhouse area.

AVS051 - Looking southwest out of the su

22 AVS052 - Looking north into the standing ore house structure.

AVS053 - Looking east within the standing blast furnace structure.

23 AVS054 - Looking east within the standing blast furnace structure.

„,.. AVS055 - Looking east within the standing blast furnace structure.

24 AVS056 - Looking east within the standing blast furnace structure.

AVS057 - Looking east within the standing blast furnace structure.

25 mft^> V"^>^JJfC-^' - fcy -*'Jrj-T '• *' -!^^6"r-,- -^: -^ .-^"-^^f^s^sN-"-

AVS058 - Looking east within the standing blast furnace structure.

AVS059 - Looking east within the standing blast furnace structure.

26 AVS060 - Looking east within the standing blast furnace structure.

VS061 - Looking east within the standing blast furnace structure.

27 AVS062 - Looking east within the standing blast furnace structure.

Test Pit #3 (AVTP03) - Looking east into pit. See text for soil layer descriptions.

28 ATTACHMENT B

LABORATORY ANALYTICAL REPORTS ASARCO

April 25, 2001 "-"

Mr. Andy Koulermous McCulley, Frick & Oilman, Inc. 4900 Pearl E. Circle #300W. Boulder, CO 80301

Dear Mr. Koulermous

Attached are the analytical results and quality control data for (72), seventy-two soil samples collected on April 11,2001, in association with the Asarco AV/CZL Smelter Investigation proj ect and received by the laboratory on April 13,2001.

The samples were oven dried; sieved through a #10 sieve as requested; then digested using EPA method 3050, and analyzed using an ICP spectrometer.

If you need further information, please call at (801) 263-5266.

Sincerely,

larami Senior Chemist

c.c. GRStanga (w/attach.) ' "" Ambrrison (w/attach.)

ASARCO Incorporated 3422 South 700 West, Salt Lake City. Utah 84119-4191 (801) 262-2459 FAX (801) 261-2194 ASARCO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT

Leadvllle

Technical fiervlcea (Project 1201) Batch No: L0104B7

•B §S§lifi£ 'hri^^^^^^^^^^^^

L010407-001 ll-APR-01 AVS001 AS 12930. ppm MDK 20-APR-Ol 6010 PB 11030. ppm MDK 19 -APR- 01 6010

L010407-002 ll-APR-01 AVS002 AS 3737. ppm MDK 19-APR-01 6010 PB 14510. ppm MDK 19-APR-01 6010

L010487-003 ll-APR-01 AVS003 AS 202. r ppm MDK 19-APR-01 6010 PB 866. ppm MDK 19-APR-01 6010

L010407-004 ll-APR-01 AVS004 AS 1936. ppm MDK 19-APR-01 6010 PB 14010. ppm MDK 19-APR-01 6010

L010487-OOS ll-APR-01 AVSOOS AS 2107. ppra MDK 19-APR-01 6010 PB 28900. Ppm MDK 20-APR-Ol 6010

L010407-OOG ll-APR-01 AVS006 AS 774. ppm MDK 19- APR- 01 6010 PB 7993. ppm MDK 19-APR-01 6010

L010487-007 ll-APR-01 AVS007 AS 2413. ppm MDK 19-APR-01 6010 PB 349SO. ppm MDK 20-APR-Ol 6010

L010487-008 ll-APR-01 AVSOOS AS 2156. ppm MDK 19 -APR- 01 6010 PB . 21200. Ppm MDK 19-APR-01 6010

L010407-009 ll-APR-01 AVS010 AS 1699. PPm MDK 19-APR-01 6010 •Pfl 23780. Ppm MDX 19-APR-01 6010

L010487-010 ll-APR-01 AVS011 AS 481. PPm MDK 19-APR-01 6010 PB 23200. ppm MDK 19-APR-01 6010 i L010407-011 ll-APR-01 AVS012 AS 1782. PPm MDK 19-AFR-01 6010 PB 16350. ppm MDK 19-APR-01 6010 1 : L010487-012 ll-APR-01 AVS013 AS 111S. ppm MDK 19-APR-01 6010 PB 15650. ppm MDK 19-APR-01 6010

L010487-013 ll-APR-01 AV8014 AS 971. Ppm MDK 19-APR-01 6010 PB 28610. Ppm MDK 20-APR-Ol 6010

Page 1 ASARCO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT

Leadville

Technical Services (Project 1201) Batch Not L0104B7

isix&>/! / f"'£&$£fj& &J&bl£ * " "* '' $$fwis&£$feSi^£

L010407-014 ll-APR-01 AVS01S AS 3333. ppm HDK 19-APR-Ol 6010 PB 39040. ppm MDK 20- APR- 01 6010

L010407-01S ll-APR-01 AVS016 AS 440. ppm MDK 19-APR-Ol 6010 PB 4562. ppm MDK 19-APR-Ol 6010

L010407-016 ll-APR-01 AVS017 AS 1481. ppm MDK 19-APR-Ol 6010 PB 11990. ppm HDK 19-APR-Ol 6010

L010407-017 ll-APR-01 AVS018 AS 3601 . ppm MDK 19-APR-Ol 6010 PD 1G070. ppm MDK 19-APR-Ol 6010

L010407-018 ll-APR-01 AVS020 AS 2607. ppm MDK 19-APR-Ol 6010 PB 19960. ppm MDK 19-APR-Ol 6010

L0104B7-019 ll-APR-01 AVS021 AS 8818. ppm MDK 20-APR-01 6010 PB 10660. ppm . HDK 19-APR-Ol 6010

L010487-020 ll-APR-01 AVS022 AS 2229. ppra MDK 19-APR-Ol 6010 PB 10650. ppm MDK 19-APR-Ol 6010

L0104B7-021 ll-APR-01 AVS023 AS 307. ppm MDK 19-APR-Ol 6010 PB 6202. ppm MDK 19-APR-Ol 6010

L0104B7-022 ll-APR-01 AVS024 AS 2673. ppm MDK 19-APR-Ol 6010 PB 23120. ppm HDK 19-APR-Ol 6010

L010487-623 ll-APR-01 AVS026 AS 151. ppm MDK 19-APR-Ol 6010 ' PB 2164. ppm HDK 19-APR-Ol 6010 '

L0104B7-024 ll-APR-01 AVS027 AS 15040. ppm HDK 20-APR-01 6010 PB 16900. ppm HDK 19-APR-Ol 6010

L010487-025 ll-APR-01 AV6028 AS 2520. ppm 19-APR-Ol 6010 PB 27160. ppm HDK 20-APR-01 6010

L0104B7-026 ll-APR-01 AV6029 AS 3464. ppm MDK 19-APR-Ol 6010 PB 44010. ppm HDK 20-APR-01 6010

Page 2 ASARCO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT

Leadvllle

Technical Services (Project 1201)

Batch Noi L010487

Stam®mm®mmi8!^m&

L0104B7-027 ll-APR-01 AVS030 AS 963. ppm MDK 19-APR-Ol 6010 -PB 8158. ppm MDK 19-APR-Ol 6010

L0104B7-02B ll-APR-01 AV8032 AS 670. ppm MDK 19-APR-Ol 6010 PB 4324. ppm ' MDK 19-APR-Ol 6010

L0104B7-029 ll-APR-01 AVS033 AS 1148. ppm MDK 19-APR-Ol 6010 PB 8107. ppm MDK 19-APR-Ol 6010

L010487-030 ll-APR-01 AVS034 AS 2128. ppm MDK 19-APR-Ol 6010 PB 22730. ppm MDK 19-APR-Ol 6010

L010487-031 ll-APR-01 AV803S .AS 760. ppm MDK 19-APR-Ol 6010 PB . 7579. ppm MDK 19-APR-Ol 6010

L0104B7-032 ll-APR-01 AV8036 AS 2115. ppm MDK 19-APR-Ol 6010 PB 21370. ppm MDK 19-APR-Ol 6010

L010487-033 ll-APR-01 AVS037 AS 10480. ppm MDK 20-APR-01 6010 PB 11540. ppm MDK 19-APR-Ol 6010

L010487-034 ll-APR-01 AVS038 AS 569. ppm MDK 19-APR-Ol 6010 PB 10310. ppm MDK 19-APR-Ol 6010

1,010487-035 ll-APR-01 AV8039 AS 567. ppm MDK 19-APR-Ol 6010 PB 10320. ppm MDK. 19-APR-Ol 6010 i L010487-036 ll-APR-01 AVS040 AS 3378. ppm MDK 19-APR-Ol 6010 PB 46590. ppm MDK 20 -APR- 01 6010

L0104B7-037 ll-APR-01 AVS041 AS 62000. ppm MDK 2S-APR-01 6010 PB 42230. ppm MDK 20-APR-01 6010

L0104B7-03B ll-APR-01 AVS042 AS 7146. ppm MDK 20-APR-01 6010 PB 5450. ppm MDK 19-APR-Ol 6010

L0104B7-039 ll-APR-01 AVS043 AS 1472. ppm MDK 19-APR-Ol 6010 PB 22790. ppm MDK 19-APR-Ol 6010

Page 3 ASARCO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT

Leadville

Technical Servlcea (Project 1201)

Batch Noi L010487

jw.i™ -~f^--y^ -™.^ f t$ f.fvf-,f^ r rf jff^jYA S^SATSTIPS w f f K&S L^ S^ ^lfi-**&2& S8&«tei*«wK¥ WSSSSSSSJSMWHRSBSS

L0104B7-040 ll-APR-01 AVS044 AS 2393. ppra MDK 19-APR-01 6010 PB 10690. ppm MDK 19- APR- 01 6010

L010407-041 ll-APR-01 AVS045 AS IB. ppm MDK 19-APR-01 6010 PB 1S1. ppm MDK 19-APR-01 6010

L010487-042 ll-APR-01 AVS046 AS 1068. - Ppm MDK 19-APR-01 6010 PB 16110. ppm • MDK 19-APR-01 6010

L0104B7-043 ll-APR-01 AVS047 AS 117. ppm MDK 19-APR-01 6010 PB 1638. ppm MDK 19-APR-01 £010

L010487-044 ll-APR-01 AVG048 AS 3839. ppra MDK 19-APR-01 6010 PB 28120. ppm MDK 20-APR-01 £010

L010487-04S ll-APR-01 AV8049 AS 2458. ppm MDK 19-APR-01 6010 PB 36860. ppm MDK 20-APR-01 6010

L010487-046 ll-APR-01 AVS050 AS 1667. ppm MDK 19-APR-01 6010 PB 16380. ppm MDK 19-APR-01 6010

L010487-047 ll-APR-01 AVSOS1; AS 5S6. ppm MDK • 19- APR- 01 6010 PB 60B70. ppm MDK 20-APR-01 £010

L010487-048 ll-APR-01 AVSOS2 AS 2938. ppra MDK 19-APR-01 6010 PB 4797. ppm MDK 19-APR-01 £010

L010487-0*49 ll-APR-01 AVSOS3 AS 2841. - ppm MDK 19-APR-01 £010 PB 18220. ppm MDK 19-APR-01 £010

L010487-050 ll-APR-01 AVS054 AS 4394. ppm MDK 19-APR-01 6010 PB 1S2BO. ppm MDK 19-APR-01 6010

L010487-OS1 ll-APR-01 AV8055 AS 7S66. ppm .MDK 20-APR-01 £010 PB 10800. ppm MDK 19-APR-01 £010

L010487-052 ll-APR-01 AV80S6 AS 1227. ppQ MDK 19-APR-01 6010 PB 10170. ppm MDK 19-APR-01 6010

Page 4 ASARCO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT

Leadvllie Technical Services (Project 1201) Batch Hoi L0104B7

r S^^HHfti^wMs?~/" tt'f'& W' i&klo&SktKS&i ffl^^^K^^aj^^kU^^illii$tt£$^^stesl

L010407-053 ll-APR-01 AVSOS7 .AS 7446. ppm MOK 20-APR-Ol 6010 = PB 11430. ppra MOK 19-APR-01 6010

L0104D7-OS4 ll-APR-01 AVS050. AS 7843. ppm MDK 20-APR-Ol 6010 PB 20310. ppm MOK. 19-APR-01 6010

L010407-OSS ll-APR-01 AVS061 AS 1765. ppra MOK 19-APR-01 6010 PB 59BB. ppra MOK 19-APR-01 6010

L0104B7-OS6 ll-APR-01 AVTP01-01 AS 3048. ppm MDK 19-APR-01 6010 PB 4212. ppm MOK 19-APR-01 6010

L010487-OS7 ll-APR-01 AVTP01-02 AS 3568. ppm MDK 19- APR- 01 6010 PB 6B68. ppm MOK 19-APR-01 6010

L010407-OSO ll-APR-01 AVTP01-03 AS 3677. ppm MDK •19-APR-01 ~ 6010 PB 5867. ppra NDX 19-APR-01 6010

L010407-059 ll-APR-01 AVTP01-04 AS 3751. ppm MDK 19-APR-01 6010 PB 6414. ppm MDK 19-APR-01 6010

L010487-060 ll-APR-01 AVTPOI-OS AS 3437. ppm MDK 19-APR-01 6010 PB 22590. ppm MDK 19-APR-01 6010

L0104B7-061 ll-APR-01 AVTP02-01 AS 7444. Ppm MDK 20-APR-Ol 6010 PB 7920. ppm HDK 19- APR- 01 6010

L0104B7-062 ll-APR-01 AVTP02-02 AS 8262. ppm MDK 20-APR-Ol 6010 PB 8976. ppm MDK 19-APR-01 6010

L010487-063 ll-APR-01 AVTP02-03 AS 3315. ppra . MDK 19-APR-01 6010 PB 9633. ppm MDK 19-APR-01 6010

L0104B7-064 ll-APR-01 AVTP02-04 AS 2267. ppm MDK 19-APR-01 6010 PB 10050. ppra MDK 19-APR-01 6010

L0104B7-065 ll-APR-01 AVTP02-05 AS 3162. ppra MDK 19-APR-01 6010 PB 10080. ppm MDK 19-APR-01 6010

Page s ASAROO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT Leadville Technical Services (Project 1201) Batch Not L010487

L010407-06G ll-APR-01 AVTP03-02 AS 6569. ppm MDK 20-APR-01 6010 PB 636. ppra MDK 19-APR-01 6010

L0104B7-067 ll-APR-01 AVTP03-03 AS 4273. ppm MDK 19-APR-01 6010 PB B71. ppm MDK 19-APR-01 6010

L010407-060 ll-APR-01 AVTP03-04 AS 2713. ppm MDK 19-APR-01 6010 PB 472. ppm MDK 19-APR-01 6010

L010487-069 ll-APR-01 AVTP03-OS AS 2341. ppm .MDK 19-APR-01 6010 PB 473. ppra MDK 19-APR-01 6010

L010487-070 ll-APR-01 AVTP04-02 AS 1402. ppm MDK 19-APR-01 6010 PB 27930. ppm MDK 20-APR-01 6010

L010487-071 ll-APR-01 AVTP05-01 AS 1894. ppm MDK 19-APR-01 6010 PB 15640. ppm MDK 19-APR-01 6010

L010487-072 ll-APR-01 AVTP05-02 AS 2687. ppm MDK 19-APR-01 6010 PB 44330. ppm MDK 20-APR-01 6010

fth Approved

Reviewer /

Page 6 A8AROO TECHNICAL SERVICES CENTER

ANALYTICAL DATA REPORT

Leadville

Technical Serviceo (Project 1201)

Batch Not HO010300

JI|ffii|£^\^bM&2*£|^ %,38&&8>*£ ssNN.?? i|£JS^k|iy?§ TOwSSmwRCTWBwKSSgSssSSWmWH'! ne«mS3wiwH8groflNHn»3Q t&tv&ril sBmMf8&32t!&m?Mw®mimffim %_^^^^^^^^^

HG010308-1 Matrix Spike AS 88 tRecovery MDK 19-APR-Ol . 6010 .-PB SR>4SA tRecovery MDK 19-APR-Ol. 6010 i HG010)08-2 Prep Blank AS <5.0 PPm MDK 19-APR-Ol 6010 PB <5.0 ppm MDK 19-APR-Ol 6010

H0010308-3 Lab Control Sample AS 101 tRecovery MDK 19-APR-Ol. 6010 PB 108 tRecovery MDK 19-APR-Ol 6010

HC010300-4 Matrix Spike Duplicate AS t RPD MDK 19-APR-Ol £010 PB 2.3 t RPD MDK 19-APR-Ol 6010

HG01030B-5 Reporting Limit AS 5.0 PPm 6010 PB 5.0 ppm 6010

HG010308-6 Matrix Spike AS SR>48A tRecovery MDK 19-APR-Ol 6010 PB SR>4SA tRecovery MDK 19-APR-Ol 6010

HG010308-7 Prep Blank AS

HG010308-8 Lab Control Sample AS 93 tRecovery MDK 19-APR-Ol 6010 PB 100 tRecovery MDK 19-APR-Ol 6010

HO010308-9 Matrix Spike Duplicate AS 3 t RPD .MDK 19-APR-Ol 6010 PB 3.8 t RPD MDK 19-APR-Ol 6010

HG01030B-10 Matrix Spike AS 91 tRecovery MDK 19-APR-Ol 6010 PB SR>4SA tRecovery MDK 19-APR-Ol 6010

NG010308-11 Prep Blank AS <5.0 ppm MDK 19-APR-Ol 6010 PB <5.0 ppm MDK 19-APR-Ol 6010

HG010308-12 Lab Control Sample AS 100 tRecovery MDK 19-APR-Ol 6010 PB 102 tRecovery MDK 19-APR-Ol 6010

HG010308-13 Matrix Spike Duplicate AS 1.6 t RPD MDK 19-APR-Ol 6010 PB 2.7 t RPD MDK 19-APR-Ol 6010

Page 1 ASARCO TECHNICAL 'SERVICES CENTER

ANALYTICAL DATA REPORT

Leadville

Technical Services (Project 1201)

Batch Noi HO010308

HC010308-14 Matrix Spike A3 SR>4SA % Recovery MDK 19-APR-01. 6010 PB SR>4SA %Recovery MDK 19-APR-01 6010

HG010308-1S Prep Blank AS <5.0 ppm MDK 19-APR-01 6010 PB <5.0 ppra MDK 19-APR-01 6010

HG01030S-16 Lab Control Sample AS 100 %Recovery MDK 19-APR-01 6010 PB 105 %Recovery MDK 19-APR-01 6010

HC010300-17 Matrix Spiko Duplicate 'AS 1.0 % RPD MDK 19-APR-01 6010 PB 7.1 % RPD MDK 19-APR-01 6010

Approved

Page 2 MFG, INC. CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS COCNO. 42724 . D Arcoto Olttce GffcouWer Office Qlrvhe Office QOsbum Office QSan Ffnnelsco Office DSeallle Office 11 65 G Street. Sulla E x>4900 Peart East Chela 17770 Cartwrtght Rood P.O. Box 30 71 Stevenson Street 1920336th Avenue W. .a • Areala.CA 95521-5817 Suite 300W Suite 500 Wallace. ID Suite 1450 Suite 101 Tot (7071 820-8430 Boukfor. CO 80301-6116 Irvine. CA 92614-5850 83873-0030 San Francisco. CA 94105-2941 Lynnwood. WA 98038-5707 Fax (707) 826-6437 Tel: 1303)447-1823 Tet (949)253-2951 Tel: (208)558-6811 Tel: (415) 495-7110 Tot (425) 921-4000 Fiuc (303) 447-1836 FBJC (949) 2534954 Fat (208) 556-7271 Fex (415) 495-7107 Fax:(425)921-4040

PROJECT NO: OlSSUU -S"! PROJECT NAME: Av//C21— TAJV/ESTIGAT\CVSJ PAftF- 1 r>F: * £

S/\MPLER (Sianature^: Ac Gr O^v C«3 VK/\ PROJECT MANAGER: A***>Y k . DATE: ^////0| METHOD OF SHIPMENT: U -X CARRIEFVWAYBILL NO: DESTINATION: AS/VZ.CO ~rr r '

SAMPLES ANALYSIS REQUEST Sample Preservation Containers Constituents/Method Handling Remarks s SOAXC A.J Prt*Ji)3*J \3tJ'c\ ^^^ UJ ^^ / Field o *^J *^J / r\ \ o o LU ^^^^ ^> — Sample Q. — £1 o 1 i d CJ ^^^r STANDAR D Identification DATE TIME i 1o FILTRATION * J A\/G25Q^d— 9

Av)si\0 1 ;1 \ y /\MS0lj \ / v, / J/ ii TOTAL NUMBER OF CONTAINERS . ^ LABORATORY COMMENTS/CONDITION OF SAMPLES COOler Temp' RELINQUISHED BY: RECIEVED BY: ; // SIGNAJJJRE} PRINTED NAME COMPANY DATE TIME SIGNATURE PRINTED NAME ' ^COMPANY AL,C^^r== A°t>X KoU(^?l^o> I*F&- *t/n /n| l2:ctS- ^ ^^tevv^sw^^r^Aor^e^s.o^ -f\SA£c"$ - -

LABORATORY

'OX Itate M-apma M-amgnoBf SO-«* a- C-pflWhm /)•* or-offw . CWOhoj.- f-ftoOt 0-pai T-uaon t-taa or-aam Htntae: r-oml II- mount ^•^ msnwBimo* pattnticter muxtuimtaiaitrw MwrE-Ramtoftttow • • . MFC, INC. s* CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS COCNO. 42725 QAicela Otllca H&x/lder Oldce D Irvine Office OOsburn Office QSan Francisco Office QSaallle Oinca r 1 1 65 G Street. SufleE 4900 Pearl East Ctrda 17770 CartwrigM Road P.O. Box 30 71 Stevenson Street 1 9203 36th Avenue W. i Arcflta, CA 95521-5817 Suite 300W SuRaSOO Wallace. ID Suite 1450 Suite 101 Tal: (707)826-8430 Boufctor. CO 80301-6118 • Irvine. CA 9Z814-S650 83873-0030 San Frandsoo. CA 94105-2941 Lynnwood. WA 98036-5707 Fax:(707)62641437 Tet (303)447-1823 Tec (949) 253-2951 Tel: 1208)556-6811 Tel: (415)495-7110 Tat (425) 921-40OO Fax: (303) 447-1836 Fax: (949) 253-2954 Fax (208) 556-7271 Fax (415) 495-7107 Fax (425) 921-4040

PROJECT NO: O|S3^k-S"' PROJECT NAME: Av /C2L Xv/vdr-n^A-noAj PAfiF. O> np. ^ SAMPLER (Signature): Ac fcV .tWjt (ZoLe^v PROJECT MANAGER: XUox k. DATE: ^4////O/ METHOD OF SHIPMENT: Enl- £* CARRIERAVAYBILL NO: DESTINATION: A^/V^COTTC

SAMPLES ANALYSIS REQUEST

Sample Preservation Containers Constituents/Method Handling Remarks

1 St&t^t &.$ p/XA/lTJU^ i 01 tJ Field CO 0 o 0* LLJ 3 CO Sample o CO 3:^ §^ v» 0 5 Z 01 o'

0 E. STANDAR D Identification DATE TIME 8 FILTRATION * g A\)£d>!3- LJ./J//OI SO P I x^ Av^Qll 1 ^ lk We L/A f 15" U. d k " _A\J£0I6 «3\ 5?X>~/)U.J oOl "Uy K\J^(7- Avr^c^'^ AV^C3f>2-5^ Avisos 2.1 f \ ^\\j^027x ^ (/ I > t \/ 1 . \b. l^^^j^^^ttMH^^I&^^i^m^ TOTAL NUMBER OF CONTAINERS . LABORATORY coMMEKracoNomoN OF SAMPLES Cooler Temp: RELINQUISHED BY: . RECIEVEDBY: / SIGNAJURE • PRINTED NAME COMPANY DATE TIME SIGNATURE PRINTED NAME .COMPANY

•pr^S^^^ Ar>»i>y kontee^o; Av£.£- Hll,/CH 12 -.or s& •" ~ ; •^li^jo\ k°»45 '. ^Msvl3x ^n^T^^CX^eJoS<^*'^ f-Y^A?^"^ LABORATORY

•fir MMc 40-a«a«Bi «4-l lllllllil SO-a*a -*«*.»'••MM* 4-a> er-«Mr CtaWwr r-t&H •••bo r-Mka f-tan OT-**t maka f-mutd U-mtttml MKAajChjr* KUORlJaniayCkJr HNnEAaMkOtMir MFG, INC. : CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS COCNO. 42726 . OArcata Office Srfoutder Olllce QlrvtneOllice QOsburn Office QSan Francisco Olllce OSeal le Olllce r 1 105 Q Street. SulleE 4900 Peart East ClrctB 17770 CertwrigM Road P.O. Box 30 71 Stevenson Street 192013 361h Avenue W. i Arcata. CA 95521-5817 Suite 300W Suite 500 Wallace. ID Suite 1450 Suite 101 Tec (707) 826-8430 BouMer. CO 80301-6118 Irvine. C A 9261 4-5850 83873-0030 San Frandseo. CA 94 105-2941 Lynnwood. WA 98038-5707 Foe (707) 8204437 • lac (303) 447-1823 • Teb (949) 253-2951 Tec (208) 556-681 1 Tel: (415)495-7110 Teh 425) 921-4000 Fax (303) 447-1836 lte:(949]253-2954 Fox (208) 556-7271 Fax: (4 15) 495-7 107 Fax: 425)921-4040

PROJECT NO: C>1S1^-5~I F ROJECT NAME: AV/CZL J^V£:lT7^-/lTiOA> FAfiP- 3 OR ^ SAMPLER (Sianature): A^ Gn tWv iytn PROJECT MANAGER: J^DV k. DATE: ^ ////^/ METHOD OF SHIPMENT: ft J - £*• CARRIERAA/AYBILL NO: DESTINATION: /4r/Vlf o T C C.

SAMPLES ANALYSIS REQUEST

Sample Preservation Containers Constlluenls/Melhod Handling Remarks

0. oi Field *X o wrcU — cytA; dU5 ~ o O LU v^- £ Sample 75 Q. ^ i1d 0 d 1 Identification DATE TJME o: STANDAR D X o [FILTRATION - ) AV£(^23 ^Af/0' So p r_ X i * Av/iC^-M- . AM 5.0^ PJjr,^,^ rplwA /M.S021- U,A(Al

/tccxJs^^^ /Uby Kot>K££roJ A^6- 4/lf/OI \2\oS~ 4 "^ • ^/l^)/)\ 0^4S ) ^A®3-aL-*XrfkB«r-^ T~fAt*A^/rQav A?A££j^ '•• LABOnATORY

'SEC IttAc AO-

PROJECT NO: OlS^/tLs-S" / PROJECT NAME: A V /£.ZL T/\jV/£ £ T ( 6^A~n Ort PAGE: A OR £

SAMPLER (Signalture): /tz, (or \)o*J<. \j&.\jLf\ PROJECT MANAGER: AfJbV k . DATE: ^ / (t/ 0 f METHOD OF SHIPMENT: p J - C.fi CARRIERA.VAYBILL NO: DESTINATION: Ae/V2.CO "7TTC

SAMPLES ANALYSIS REQUEST Sample Preservation Containers Constituents/Method Handling Remarks 1 .Nonvunid

tii 1 .*x ^•''ck — W/" ^ cU*^ Reid Q n O LU CO Sample 0. —r 2 i o 6 O tr STANDAR D Identification DATE TIME X* o 1 AV-£G!>£$~ ^/tf/oi w ^j P r X A\L$9K£ ,. ANJScfeT P^cXA^rciiA/A 2g UrvvA,S«_I (ioAvo\ §29 JC i^-pltJ

RELINQUISHED BY: - RECIEVEDBY: PRINTED NAME COMPANY TIME SIGNATURE PRINTED NAME ...pOMPANY / SIGN^fdRtT) DATE

/ r. '^^*" "AwD/ KO(4l£Jb«& A/T^- 4/ft/Of (2 : 0 _T 4/i*>)0U o°\H5 c ^5x9L»ArvZS*J" r!AD€\ev\Sejv-\ (As>A^-C^> LABORATORY • .:.-.

-(B9> r-M» f-tun OJ-iOm ntnOoc f-Omtd l/.ndbntf •Itt ™».^».-~*.~*£,£^^ rie MFG, INC. CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS coc NO. 42728 . OArcala Office CMiSjtdar Of ftae Ohvlne Office OOsbum Office '• DSan Frandsco Office QSeartle Office rj 1 165 O Street. SufleE 4900 Poor! East Circle 1 7770 CartwrtgM Road P.O. Box 30 7J Stevenson Slreet 1920336th Avenue W. Arcnla. CA 9SS21-5817 Sutle 300W Suite 500 Wallace. ID Sulla 1450 Sulle 101 Tot (707) 826-8430 Boulder. CO 80301-6118 Irvine. CA 92614-5850 83873-0030 Sen Frandsco, CA 94105-2941 Lynnwood. WA 96038-5707 Fax: (707) 828-8437 Tek (303) 447-1823 Tat (949) 253-2951 Tet (208) 556-6811 Tel: (415)495-7110 let (425)921-4000 FaJC (303) 447-1838 Fax (949) 253-2954 Fax (208) 556-7271 Fax (416} 495-7107 Fax (425) 921-4040

PROJECT NO: O\ 5 3^-3" I PROJECT NAME: A^/C^i- (/OUtlT-(6AncyO PAGE:-^*^ OF: 2 SAMPLER (Sianature): A^ Gr tWt Colt>i>N PROJECT MANAGER: A^^U. k • DATE: U 1 1 / /Ol METHOD OF SHIPMENT: frJ Ex CARRIERM/AYBILL NO: ^ DESTINATION: ^AOCQ TS

SAMPLES ANALYSIS REQUEST

Sample Preservation Containers Constituents/Method Handling Remarks o^*^* &J PrCAJtfeixJ

01 tov/'e.K ~- Q'~^\ ^ CAVfiJ Reid x o o" Q LU 1 3 en I * /"^ V Sample . 0 1 i" C) J STANDAR D / Identification DATE TIME S 8 FILTRATION * ~ ^ fc z * »1 rr » AVS0AS" /f/fl/oj SO p ^: 1 X A\)£t$Ak \ A^£ kj JJL- &Jf$5~& o^oKra Av/10/f Av/SG^TZ- AvStfs'l ir- V i r v ' I/ \l At/.£<#r^ V i / ' J/ ^^PSiM»li&>xis&!lit£}'&&i&!£f!!t$i8iiKw feSnS • J s( 8S5S1 K6 &&&! Is$ SiSSJ^CS al Si» TOTAL NUMBER OF CONTAINERS Ir— v LABORATORY COMMENTS/CONDITION OF SAMPLES Cooler Temp* REUNQUISHED BY: RECIEVEDBY: \ SIGNAJU^E PRINTED NAME COMPANY DATE . TIME SIGNATURE PRINTED NAME COMPANY

n^J>^^^ A*>W ]CO(AL£ltS*V frKj- ^/^/"Ol (2 : i?r- *f/is)-&\ ^C\t\^ r =l\S^iirtv-bao~\ T"^V»A-«^V"SeAO Tfe^-CUJi LABORATORY

•ffir MMc AO-jgomo M-agaq>nta SO-jof jt-iM|g» P-pnam k-* OT-atxr .Comhfu.- P-ptu* o-gtu r-trftn 8-too or-aatr /Boom f-OaitsI U-uOand otsTRiBimoM: paxfuudvr itutMeutmiarCwt wncAMmitoattmor -ft. MFG, INC. CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS coc NO. 42730 DArcetaOlflco DBoufda^ r Office D Irvine omc8 OOsbum Office , OSan Ffandsco Office O Seattle Office 1 1 65 QStresl. Sulla E 4900 Peart East Onto 17770 CartwrigM Road P.O. Bent 30 71 Stevenson Street 19203 36th Avenue W. Arcatn. CA 95521-5817 Sulla 300W SuDeSOO Wallace. ID Suite 1450 Sulla 101 Tot (707) 8204430 BouWar. CO 80301-61 18 trvtne. CA 92614-5850 83873-0030 San Francisco. CA 94105-2041 Lymrwood. WA 88038-5707 Fax: (707) 8264437 Tat (303)447-1823 tt± (949)253-2951 Tel: (208) 5584811 Tel: (415)495-7110 Tet (425)921-4000 Fax (303) 447-1836 Fax: (949) 253-29S4 Rue (208) 558-7271 Fax (415) 495-7107 Fax (425)921-4040

PROJECT -r S"! PROJECT NAME: PAGE: OR. SAMPLER (Signature): Ac PROJECT MANAGER: XUtU k. DATE: METHOD OF SHIPMENT: CARRIERAVAYBILL NO: DESTINATION:

SAMPLES ANALYSIS REQUEST

Sample Preservation Containers Constituents/Method Handling Remarks

tu U- — cy- Reid M Sample co —0 Identification DATE TIME T£ MFG, INC. / CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS COCNO. 42731 . OArcata Office CMfautder Office Dlrvlne Office QOsbum Office OSan Frandsco Oince DSeallle Office ri 1 185 G Street. SufleE 4900 Peart East Ctrcta 1 7770 Cartwrigtil Road P.O. Box 30 71 Slevenson Street 19203 36ltt Avenue W. Arcala, CA 85521-5817 Sulla 300W Suite 500 Wallace. 10 Suite 1450 Sullo 101 Tet (707)826-8430 BouMer, CO 80301-0118 Irvtna, CA 92614-5850 83873-0030 San Frandsco. CA 04105-2941 Lynnwood. WA 98038-5707 FUC (707) 828-8437 Tel: (303)447-1823 Tet (949) 253-2951 Tel: (208) 556-6811 Tel: (415)495-7110 lei: (425) 921-4000 Fex (303) 447-1838 FttK (949) 253-2854 Fax (208) 558-7271 ' Fee (415) 405-7107 Fax (425) 821-4040

PROJECT NO: Of^^£»4-ri . PROJECT tJAME: AV//C2L TA>V£ST((V\'nox^ PAGE: "^ OR S SAf^P LER (Slgnature): Ac Qn Dwv/^ C.D\lAA PROJECT MANAGER: /UeL^ k . DATE: Ltlnfol METHOD OF SHIPIWENT: 41 Ex CARRIERM/AYBILL NO: ^ DESTINATION /TA2.CO TTC.

SAMPLES ANALYSIS REQUEST

Sample Preservation Containers Constituents/Method Handling Remarks a.j PresjCo^J (X Ul — c/x* CSAXCJ^ Field * L * m a i UJ • Sample c3 3 Q. £1 8 w i o d > -!_ ^ d STANDAR D Identification DATE TIME I o FILTRATION * "=C 1 AVTP0Z-0) 't/H/OL fo P i \ X 1 )l i AV/TT d)i- d>Z U?Q-Ot TO'lAT^V AVTP $2 -^'? lAAvA-ate* DorWo\ A\JTP4 2- " ^/ C" oJiW o^o. MW AvrrPqK-rf Z AvrrPq^3>~ 03 AvrrPote — $£f Avnl>^3>-^r I f • i V ' ^ / Avn?q5it — cz$ ^, f / \ w TOTAL NUMBER OF CONTAINERS . /-) LABORATORY COUMENTS/CONDmON OF SAMPLES COOlef Temp' iMMKMwMw RELINQUISHED BY: RECIEVED BY: . , SIGN^CLjRE PRINTED NAME COMPANY DATE TIME SIGNATURE PRINTED NAME .COMPANY < y /I_Ou_— -•*~ — AAI&X ^owtj5^«af Av/C- L+ildcX r2.'o_r ^f^>] icsOXvUMl^ T ^SA^AOS^YN IVS.^^ LABORArORr ^ •JOr liatc AO-tpmn M-a>aqa«ai S0-«f &-«<*» P-prntan X-rt Of-ater tauten; C-pte* fl-(ftn r-ttita, ».*» 07-

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SAMPLES ANALYSIS REQUEST

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Reid CO D X 0 LU CO Sample o 3 0. ^ s1 6 sA O

1 LT STANDAR D Identification DATE TIME FILTRATION * (ml/oz ) v-^ X x 8 VOLUM E AvrrP^s"'^ J_ 4lrr/oi ro P I ( X PtccL^. r^L/ 'v uAivve J AvTrP<£r-f^2- /» l- 4/ N X /> LA jj rf>_^U ^ ^ dLr o^Jl^nj ••

TOTAL NUMBER OF CONTAINERS J LABORATORY COUHENTS/CONDmON OF SAMPLES CoOlerTemp* ^m&8M&m^^msStmlsm^^m^^^ ^8M§"^^i^^^^^^ mm^ii^men %Mt£z nffifttf^M RELINQUISHED BY: RECIEVED BY: / SIGN^EL/RE PRINTED NAME COMPANY DATE TIME SIGNATURE PRINTED NAME COMPANY /^^J^/-^ ^^y r^oMC^r^O/ A^FC- 4////o/ f2:oj- *jl\"*>\rA ^5^t|-5 ^{(SsJ^Voc^v-.'T K£><\€JT&CA> ^^^-^^ LABORATORY

•OX «**C 40-HMB «-«M*W. a-**.f. l r-M» t-toa ar-af* OtrOm: r-mm u -monad w»(«amJIAM^M*~

April 5,2001

Mr. Andy Koulcrmous McCulley, Frick & Oilman, Inc. 4900 Pearl E. Circle #300W. Boulder, CO 80301

Dear Mri Koulermous' •

Attached are the analytical results and quality control data for (9), nine soil samples collected on March 28,2001, in association with the Asarco AV/CZL Smelter Investigation project and received by the laboratory on March 30,2001.

The samples were oven dried; sieved through a #10 sieve as requested; then digested using EPA method 3050, and analyzed using an ICP spectrometer.

If you need further information, please call at (801) 263-5266.

Sincerely,

11 Senior Chemist

o.c. GRStanga (w/attach.) Amorrison (w/attach.)

ASARCO Incorporated 3422 South 700 West, Salt Lake City, Utah 84119-4191 <801) 262-2459 f AX (801) 251-2194 ASAKCO TECHNICAL SERVICES CBHTOt

ANALYTICAL DATA REPORT

Leadvllle

AV/C2L SHELTER IHVESTIGATrON (Project 015344-SI)

Batch Boi L010420 0 • • 3

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1.010420-001 28-KAR-01 AVGD19 A3 4301. • • ppa EH 03 -APR- 01 6010 PB 14500. ppn EH 03-APR-01 6010

L010420-002 28-MAR-01 AVSO2S AS 812. ppm EH 03-ATR-01 6010 tB 15300. ppm EH - O3-AP3-01 6010

L010420-003 2B-MAR-01 AV3008 A3 5493. ppm EH 04-APa-Ol 6010 Pa 59400.. ppm BH 04-APR-01 6010

LOL0420-004 28-HAR-O1 AVTP03-O1 AS 19900. ppm BH 04-APR-01 6010 EB C»22. ppm BH 03-APR-01 6010 * (.010420-005 28-HAS-01 AVTPOS-03 AS 7003. ppm EH 04-APR-01 6010 PB 63450. ppn EH 04-APR-01 6010

LD10420-006 2B-KAR-OL AVTPOt-Ol AS 1501. ppm BH 03-APR-01 fiOlO PB 24280. ppm BH 03-APR-01 £010 J L010420-001 2B-MAR-01 AVS063 AS 2148. ppm Bit 03-APR-01 6010 PB 5918. ppm BH 03-APIl-Ol 601O

L010420-000 28 -MAR- 01 AVSO60 • A3 - 4205. ppm EH 03-APR-01 6O1O PB 12410. ppn BH 03-RPR-01 6010

1.010420-009 28-MAR-01 AVOS9 AS 386SO. ppm EH 04 -APR- 01 6010 PB 28670. ppa BH 04 -APR- 01 eoao ASABOO TEOttUCAl, 6BRVICBS CBNTBR

ANALYTICAL DATA REPORT

Leadville ro § AV/C2L SHEUSft INVESMCAIKW (Project 015344-51) h*

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MG0102S9-L KBtrlX Spike --AS IRecovery BK 03-lkPR-Ol £010 IB ^Recovery Bit 03-APR-01 S010

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W3010IS9-3 Lab Control Saiqple A3 100 tRecovery EH OJ-APR-01 £010 I'D 102 IReccmcy BH 03-APR-01 6010

WS01025S-* Duplicate AS 2.3 I RPD BH 03-APR-01 £010 ra % RPD BK 03-APH-01 6010

HGD10259-« Reporting llnJ-t AS 20. ppa 6010 PB ao. ppm £010

i TJ 8 APPENDIX B

BORROW AREA INVESTIGATION, LABORATORY ANALYSES, AND QUANTITY ESTIMATES APPENDIX C

REPOSITORY DESIGN SUPPORTING ANALYSES

C.I Repository Geomembrane Liner Analysis C.2 Repository Excavation Slope Stability Analysis Attachment C.I

Repository Geomembrane Liner Analysis MFG,Inc.

Calculation/Computation Set Cover Sheet Review Documentation t1 Title of Project: Job Number: Task: /ll/~C~iL j?E^£4i4t_ At-T/osJ ffj^ So Title of Calculations: tfc Sos i rcxey* i-t+je* Sysr&M P^tru/ee. /?es,sr-rf«x Calcuations By: Print Name . Date \so*J r~ #t£4**tA*j Signature x-n *J .- e>l ^—fei^t \/**Hje

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The Reviewer's/Checker's comments have been discussed with the Reviewer/Checker, and all significant issues have been resolved. •Calculation Originator: , Print Name Date

Signature • Reviewer/Checker: Print Name Date

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Apprived By: Print Name Date (Principal Investigator or Project Manager: Signature

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Fourth Edition Designing with Geosynthetics

Robert M. Koerner, PH.D., RE. H. L. Bowman Professor of Civil Engineering, Drexel University and Director, Geosynthetic Research Institute

PRENTICE HALL Upper Saddle River, New Jersey 07458 f\ P6» Z 8

156 Designing with Geotextiles Chap. 2

Figure 231 Visualization of a stone puncturing a geotextile as pressure is ap- plied from above.

tree stumps, roots, miscellaneous debris, and other items, either on the ground surface beneath the geotextile or placed above it, could puncture through the geotextile after backfilling and traffic loads are imposed. The design method suggested for this situa- tion is shown schematically in Figure 2.31. For these conditions, the vertical force ex- erted on the geotextile (which is gradually tightening around the protruding object) is as follows: (230) where

reqd = required vertical force to be resisted; da = average diameter of the puncturing aggregate or sharp object; p' = pressure exerted on the geotextile (approximately 100% of tire inflation pressure at the ground surface for thin covering thicknesses); 51 = protrusion factor = hhlda; hh = protrusion height« dtt- 52 - scale factor to adjust the ASTM D4833 puncture test value (which uses an 8.0 mm diameter puncture probe) to the diameter of the actual punc- turing object =

Example 23 What is the factor of safety against puncture of a geotextile from a 50 mm stone on the ground surface mobilized by a loaded truck with a tire inflation pressure of 550 kPa travel- ing on the surface of the base course? The geotextile has an ultimate puncture strength of 200 N, according to ASTM D4833. A P6 3 OF 3

150 Designing with Geotextiles Chap. 2

TABLE 2.12 RECOMMENDED REDUCTION FACTOR.VALUES FOR USE IN EQ. (2.25a) Range of Reduction Factors Creep Soil Clogging Reduction Intrusion Chemical Biological Application and Blinding* of Voids into Voids Clogging* Clogging Retaining wall filters 2.0 to 4.0 1.5 to 2.0 1.0 to 1.2 1.0 to 1.2 1.0 to U Underdrain filters 5.0 to 10 1.0 to 1.5 1.0 to U U to 1 .5 2.0 to 4.0 Erosion-control filters 2.0 to 10 1.0 to 1.5 1.0 to 1.2 1.0 to 1.2 2.0 to 4.0 Landfill filters 5.0 to 10 1.5 to 2.0 1.0 to 1.2 1.2 to 1 5 5tolO» Gravity drainage 2.0 to 4.0 2.0 to 3.0 1.0 to U 1.2 to 13 1.2 to 1.5 Pressure drainage 2.0 to 3.0 2.0 to 3.0 1.0 to U 1.1 to 13 1.1 to U •If stone riprap or concrete blocks cover the surface of the geotextile, use either the upper values or include an additional reduction factor. Walues can be higher particularly for high alkalinity groundwater. 'Values can be higher for turbidity and/or for microorganism contents greater than 5000 mg/1.

Sallow = SUU^F) (2-25b)

where

9«now = allowable flow rate, qa, — ultimate flow rate, RFJCfl = reduction factor for soil clogging and blinding, RFCR = reduction factor for creep reduction of void space, RF//V = reduction factor for adjacent materials intruding into geotextile's void space, RFcc = reduction factor for chemical clogging, RFBC = reduction factor for biological clogging, and IIRF = value of cumulative reduction factors.

As with Eqs. (2.24) for strength reduction, this flow-reduction equation could also have included additional site-specific terms, such as blocking of a portion of the geotextile's surface by riprap or concrete blocks.

2.5 DESIGNING FOR SEPARATION

Application areas for geotextiles used for the separation function were given in Sec- tion 1.3.3. There are many specific applications, and it could be said, in a general sense, that geotextiles always serve a separation function. If they do not also serve this func- tion, any other function, including the primary one, will not be served properly. This should not give the impression that the geotextile function of separation always plays a secondary role. Many situations call for separation only, and in such cases the geotex- tiles serve a significant and worthwhile function. X) n/UH*MEA/T A 4 or &

Sec. 2.4 Allowable versus Ultimate Geotextile Properties 149

TABLE 2.11 RECOMMENDED REDUCTION FACTOR VALUES FOR USE IN EQ. (2.24a)

Range of Reduction Factors

Application ' • Installation Chemical Biological Area Damage Creep* Degradation Degradation

Separation 1.1 to 2.5 1.5 to 2.5 1.0 to 1.5 1.0 to U Cushioning 1.1 to 2.0 U to 1.5 1.0 to 2.0 1.0 to 1.2 Unpaved roads 1.1 to 2.0 1.5 to 15 1.0 to 1.5 1.0 to 1.2 Walls 1.1 to 2.0 2.0 to 4.0 1.0 to IS 1.0 to 13 Embankments UtoiO 2.0 to 35 1.0 to IS 1.0 to 13 Bearing capacity i.lto2.0 2.0 to 4.0 1.0 to IS 1.0 to 13 Slope stabilization 1.1 to 1.5 2.0 to 3.0 1.0 to IS 1.0 to 13 Pavement overlays 1.1 to 1.5 1.0 to 2.0 1.0 to IS 1.0 to 1.1 Railroads (filter/sep.) 1.5 to 3.0 1.0 to 15 1.5 to 2.0 1.0 to U Flexible forms 1.1 to 1.5 1.5 to 3.0 1.0 to IS 1.0 to U Silt fences 1.1 to IS 1.5 to 2.5 1.0 to IS 1.0 to 1.1

•The low end of the range refers to applications which have relatively short service lifetimes and/or situations where creep deformations are not critical to the overall system performance, where

Callow = allowable tensile strength, ruit = ultimate tensile strength, RF/0 — reduction factor for installation damage, RFCT = reduction factor for creep, RFCp = reduction factor for chemical degradation, RFB0 = reduction factor for biological degradation, and I1RF = value of cumulative reduction factors.

Note that Eq. (2.24a) could have included additional site-specific terms, such as reduc- tion factors for seams and intentionally made holes. It also could .have been formulated with fractional multipliers (values

2.4.2 Flow-Related Problems For problems dealing with flow through or within a geotextile, such as nitration and drainage applications, the formulation of the allowable values takes the following form. Typical values for reduction factors are given in Table 2.12. Note that these values must be tempered by the site-specific conditions, as in Section 2.4.1. If the laboratory test in- cludes the mechanism listed, it appears in the equation as a value of 1.0.

uow = q (2>25a) *' x RF* X RFCC x RF 5- OF

148 Designing with Geotextiles Chap. 2

TABLE 2.10 TYPICAL RANGE OF PROPERTIES FOR CURRENTLY AVAILABLE GEOTEXTILES

Physical Properties' Specific gravity 0.9-1.7 Mass per unit area 135-1000 g/m2 Thickness 0.25-7.5 mm Stiffness nil to 25,000 mg-cm Mechanical Properties Compressibility nil to high Tensile strength (grab) 0.45-4.5 kN Tensile strength (wide width) 9-180 kN/m Confined tensile strength 18-180 kN/m Seam strength 50-100% of tensile Cyclic fatigue strength 50-100% of tensile Burst strength 350-5200 kPa Tear strength 90-1300N Impact strength 14-200J Puncture strength 45^50 N Friction behavior 60-100% of soil friction Pullout behavior 50-100% of geotextile strength Hydraulic Properties Porosity (nonwovens) 50-95% Percent open area (wovens) nil to 36% Apparent opening size (sieve size) 2.0 to 0.075 mm (#10 to #200) Permittivity 0.02-2.2 s"1 Permittivity under load 0.01-3.0 s"1 Transmissivity O.OltoZOX 10~3mJ/min Soil retention: turbidity curtains m.b.e, Soil retention: silt fences m.b.e. Endurance Properties Installation damage 0-70% of fabric strength Creep response g.n.p if < 40% strength is being used Confined creep response g.n.p. if < 50% strength is being used Stress relaxation g.n.p. if < 40% strength is being used Abrasion 50-100% of geotextile strength Long-term clogging m.b.e. for critical conditions Gradient ratio clogging m.b.e. for critical conditions Hydraulic conductivity ratio 0.4-0.8 appear to be acceptable Degradation Properties Temperature degradation high temperature accelerates degradation Oxidative degradation m.b.e. for long service lifetimes Hydrolysis degradation m.b.e. for long service lifetimes Chemical degradation g.n.p. unless aggressive chemicals Ratioactive degradation g.n.p. Biological degradation g.n.p. Sunlight (UV) degradation major problem unless protected Synergistic effects m.b.e. General aging actual record to date is excellent

Abbreviations: m.b.e.—must be evaluated; g.n.p.—generally no problem. A F6 6

Sec. 2.4 Allowable versus Ultimate Geotextile Properties 147

properties will sort out into their respective categories and uses, but most organizations are looking at the complete collection of tests as they were presented here. Table 2.10 is a summary table of geotextile properties. The rapidly changing mar- ket and its demands make it difficult to give accurate values, but for typical commer- cially available geotextiles, Table 2.10 gives the range of current values. For the specific values of specific types of geotextiles, the respective manufacturers should be consulted.

2.4 ALLOWABLE VERSUS ULTIMATE GEOTEXTILE PROPERTIES

It is important to recognize that many of the preceding geotextile test properties rep- resent idealized conditions and therefore result in the maximum possible numeric val- ues when used directly in design; that is, they result in upper-bound values. In the de- sign-by-function concept described in Section 2.1.3, the factor of safety was formulated around an allowable test value (Eqs. 2.2a and 2.2b). Thus, most laboratory test values cannot generally be used directly; they must be suitably modified for the in situ condi- tions. This could be done directly in the test procedure, for example, by conducting a completely simulated performance test; but in most cases this simply is not possible. Simulating installation damage, performing long-term creep testing, using site-specific liquids, reproducing in situ pore-water stresses, providing complete stress state model- ing, and so on, are generally not feasible. To account for such differences between the laboratory measured test value and the desired performance value, two approaches can be taken: 1. Use an extremely high factor of safety at the end of a problem. 2. Use reduction factors on the laboratory-generated test value to make it into a site-specific allowable value. The latter alternative of reduction factors^ will be used in this book. By doing this, the usual value of the factor of safety can be used in the final analysis. Our approach will be to refer to the general laboratory-obtained value as an ultimate value and to modify it by reduction factors to an allowable value.

2.4.1 Strength-Related Problems

For problems dealing with geotextile strength, such as in separation and reinforcement applications, the formulation of the allowable values takes the following form. Typical values for reduction factors are given in Table 2.11. Note that these values, however, must be tempered by the site-specific considerations. If the laboratory test includes the mechanism listed, it appears in the equation as a value of 1.0.

RF« X RFCfl X

(2-24b)

*In previous editions of this book, reduction factors were called partial factors of safety. This edition is changed to reflect the current trend in agency specifications and the more appropriate terminology. A P6 7

Sec. 5.6 Solid-Material (Landfill) Liners 535

Solution: The necessary information for solving the design equation is

(a) For out-of-plane tension testing, the yield-stress of HDPE (from Table 5.5c) is conservatively estimated as 20,000 kPa. (b) The mobilization distance for HDPE at 50 X 12.5 = 625 kPa (from Fig. 5.10) is approximately 80 mm. (c) The friction angle (from Table 5.7) for HDPE against Ottawa sand (5y) is 18°. (d) The friction angle for HDPE against a geonet (separate test results) (SL) is 10°. (e) These values give the required geomembrane thickness.

(625)(0.080)[tan 18 + tan 10] ' (20,000)[cos20-(sin20)(tanlO)]

= 0.00143m

» = 1.43 mm

Thus the regulated values of 1.5 mm in the U.S. or 2.0 mm in German regulations would control in this situation.

5.6.7 Puncture Protection

There are many circumstances where geomembranes are placed on or beneath soils containing relatively large-sized stones, for example poorly prepared soil subgrades with stones protruding from the surface or resting on the surface, soil subgrades over which geomembranes (particularly textured) have been dragged dislodging near-sur- face stones, and cases where crushed-stone drainage layers are to be placed above the geomembrane. All of these situations, particularly the last (which is unavoidable since it is a design situation), could use a protective geotextile to avoid puncturing the geo- membrane. Note that if the soil subgrade is a CCL, a geotextile cannot be used and the isolated stones must be physically removed. For the drainage layer case, which is com- mon to all landfills, a nonwoven needle-punched geotextile can provide significant puncture protection (recall Figure 5.8). The issue of required mass per unit area of the geotextile becomes critical. In a series of papers, Wilson-Fahmy, Narejo, and Koerner [71, 72, 73] have pre- sented a design method that focuses on the protection of 1.5 mm thick HDPE geo- membranes. The method uses the conventional factor of safety equation.

FS = ^ (5.32) Pact where

FS = factor of safety (against geomembrane puncture), pact = actual pressure due to the landfill contents (or surface impoundment), and ?6 8

536 Designing with Geomembranes Chap. 5

TABLE 5.18 MODIFICATION FACTORS AND REDUCTION FACTORS FOR GEOMEMBRANE PROTECTION DESIGN USING NONWOVEN NEEDLE-PUNCHED GEOTEXTILES .

Modification Factors

MF, MFPD MFA Angular ' 1.0 Isolated 1.0 Hydrostatic 1.0 Subrounded 0.5 Dense, 38 mm 0.83 Geostatic, shallow 0.75 Rounded 0.25 Dense, 25 mm 0.67 Geostatic, mod. 0.50 Dense, 12 mm 0.50 Geostatic, deep 0.25

Reduction Factors RF« ' Protrusion (mm) Mass per unit area (g/m1) 38 25 12 Mild leachate 1.1 Geomembrane alone N/R N/R N/R Moderate leachate 13 270 N/R N/R Harsh leachate 1.5 550 N/R 1.5 13 1100 13 U 1.1 > 1100 B 1.2 " 1.1 a 1.0 N/R = Not recommended

= allowable pressure using different types of geotextiles and site-specific conditions.

Based on a large number of ASTM 5514 experiments, an empirical relationship for Paiiow has been obtained, Eq. (5.33). It requires the set of modification factors and re- duction factors given in Table 5.18. 1 P.now= 50 + 0.00045 2 -1 (5.33) H )[MFS X MFPD X MFjlRFc/l X RFCfl091 where

Piiiow = allowable pressure (kPa), M = geotextile mass per unit area (g/m2), H = protrusion height (m), MF5 = modification factor for protrusion shape, MFj.0 = modification factor for packing density, = modification factor for arching in solids, = reduction factor for long-term creep, and = reduction factor for long-term chemical/biological degradation.

Note that in the above all MF values **1.Q and all RF values & 1.0. 6

of

Amoco Fabrics and Fibers

4508 4510 4512 4514 4516 American .American American American American Properties' . Metric Metric Metric Metric Metric Properties' Standard Standard Standard Standard Standard Physical - • '" Physical

Unit Weight (ex/ 270 10.0 335 12.0 405 14.0 470 16.0 540 Unit Weight

Grab Tensile Grab Tensile • 203 . • 0.900 250 1.11 300 . 1.33 360 1.60 400 1.78 Strength / Strength Grab Tensile Grab Tensile ' 50 50 50 50 50 Elongation Elongation

Mullen Burst • 450 3100 550 3790 650 4480 750 5170 800 5510 Mullen Burst

Puncture Asoj 0.575 165 0.730 195 0.865 230 1.02 250 1.11 Puncture ^ s' Trapezold Trapezoid 80 0.355 100 0.445 115 0.510 130 0.575 145 0.645 Tear Tear uv UV 70/500 70/500 70/500 70/500 70/500 1 Resistance1 Resistance

Hydraulic 4508 4510 4512 4514 4516 Hydraulic Apparent Apparent 100 .150 100 .150 100 .150 Opening Size 100 .150 100 !l50 Opening Size

Permittivity 1.5 1.2 • 0.90 0.80 0.70 Permittivity .

Permeability 0.30 0.30 0.30 0.30 0.30 Permeability

Row Rate 80 3255 85 3460 70 2850 60 2440 50 2035 Flow Rate

Packaging Packaging

Roll Width 15 4.6 15 4.6 15 4.6 15 4.6 Roll Width 15 4.6 15 4.6 15 4.6 15 4.6 15 4.6

V 180 54.9 165 50.3 R.oll Length 120 36.6 120 36.6 Roll Length 600 182 600 183 450 137 300 91.4 300 91.4

3 215 95 235 105 200 90 230 105 3 Gross Weight 560 Gross Weight 255 700 315 630 285 490 220 560 255

300 251 275 230 "200 '" 167 200 167 Area 1000 836 Area 1000 836 750 627 500 418 500 . 418

WA-NotAppGcabh l.phyilcilsndhyilniillcpnipcrltoraportidutiilidmumimigiidnlufi. 2 -Parcantgrabtansila strength ratained pwhowio(UVa«p(mir«(bllowlnjeo™Kioninjln«etoriirie«wthA^J«3a

ThaWonMtionconulrwdherdnUfonilihedwith^ beyond our control, vn mik> norepresentatio nabout , snd in not responsible or liable tor, the scanty or rtJsbZry of uid information or trn.perhrmtnct of any product Any specificaiicns, praptnies or applications Cited herein ara provided at Mormition onry and In no way modify amend, anlarga or eraata any warranty. Nothing contained herein Is to be conttniad is parmitsVon or» a racommamlation to infrlnga any oatitnL PMromal* is a reginared tndtmirk. ft GSE

GSE HD™ ®^ ^"* 's ° ^'9^ quality/ high density polyethylene (HOPE) geomembrane 1 ur«nc /~ L produced from a specially formulated, proprietary virgin polyethylene resin. This MUrt Ueomembrane polyethylene resin is designed specifically for flexible geomembrane applications. GSE HD contains approximately 97.5% polyethylene, 2.5% carbon black and trace amounts of antioxidants and heat, stabilizers; no other additives, fillers or extenders are used. GSE HD has outstanding chemical resistance, mechanical properties, environmental stress crack resistance, dimensional stability and thermal aging characteristics. GSE HD has excellent resistance to UV radiation and is suitable for exposed conditions.

TESTED PROPERTY TEST METHOD MINIMUM VALUES

Thickness, mils (mm) ASTMD 751/1593/5199 27 (0.68) 36 (0.90) S40.35) 72(1,80) 90(2.25)

Density/ g/cm^ ASTMD 792/1 505 0.94 0.94 0.94 0.94 0.94 Tensile Properties (each direction) ASTMD 638, Type IV

Strength at Break, Ib/in-width (N/mm) Dumbell, 2 ipm 122(21) 162(28) 243 (43) 324 (57) 405 (71) Strength at. Yield, Ib/in-width (N/mm) Gauge lengths per 65(11) 86(15) 130(23) 173(30) 216(38) Elongation at Break, % NSFStd.54 560 560 560 560 560

Elongation at Yield, % 13 13 13 13 13

Tear Resistance, Ib (N) ASTMD 1004 22 (98) 30(133) 45 (200) 60(267) 75(334) Puncture Resistance, Ib (N) FTMS101,Method'2065 39(174) 52(231) 80 (356) 105(467) 130(579) Carbon Black Content % ASTM 01 603 2.0 2.0 2.0 2.0 2.0

Environmental Stress Crack Resistance, hr ASTMD1693,Cond.B 1500 1500 • 1500 1500 1500

REFERENCE PROPERTY TEST METHOD NOMINAL VALUES

Thickness, mils (mm) ASTMD 751/1593/5199 30 (0.75) 40(1.0) 60(13) 80 (2.0) 100 (2 .5) Roll Length (approximate), ft (m) 840 (256) 650098) 420(128) 320 (97) 250(76) Low Temperature Brittleness, °F (°Q ASTM D 746, Cond. B <-107(<-77) <-107(<-77) <-107(<-77) <-107(<-77) -<-107«.77) Oxidative Induction Time, minutes ASTM D 3895, 200 °C 100 100 100 100 100 1

Pure 02, 1 atm Water Absorption, %wt. change ASTMD 570 <0.01 <0.01 <0.01 <0.01 <0.01 Moisture Vapor Transmission, g/m day ASTM E 96 <0.001 <0.001 <0.001 <0.001 <0.001 Carbon Black Dispersion ASTMD 3015 A1,A2,B1 A1,A2,B1 A1,A2,B1 A1,A2,B1 A1,A2,B1 Dimensional Stability (each direction), % , ASTM D 1 204, 1 00 °C, 1 hr ±2 ±2 ±2 ±2 ±2

Melt Flow Index, g/10 minutes ASTMD 1238, Cond.190/2.16 £1.0 £1.0 £1.0 £1.0 £1.0

GSE HD is available in 22.5 ft (6.86 m) and 34.5 ft (10.5 m) approximate roll widths. Approximate standard roll weights are 2,800 Ib (1 ,270 kg) and 4,200 Ib (1 ,900 kg) respectively. Other material thicknesses are available upon request.

This information is provided hr reference purposes only and is not intended as a warranty or guarantee. GSE assumes no liability in connection with the use of this information. Check with GSE for current, standard minimum quality assurance procedures. GSE is a registered trademark oFGSE Lining Technology, Inc. GSE Lining Technology, Inc. GSE Lining Technology GmbH Sales/liutollotlon Offices /" Distributed by: A Corporate Headquarters European Headquarters Australia 19103 Candle Road BindehuderSlraBe W Egypt Houston, Texas 77073 D-21073 Hamburg .Singapore USA Germany United Kingdom 800-435-2008, 281-443-8564 49-40-767-420 FAX: 281-8754010 FAX: 49-40-767-42-33 For environmental lining solutions...the world comes to GSE.® A fiiiniUnAlT Fnvirnnmentnl Inf Cnmnnnv V J GEOMEMBRANES/POLYETHYLENE/HDPE BBBiBTOT

Oven Aging at BS'C Tensile Properties ASTH 0 5721 UV 0>idauve Induction Dimensional PI. P] ASTH D 638 Type IV [3] Time (OIT) Resistance Properties GH II [9] Carbon Stress (min. avg.) [7] Standard High Strength Density Elongation Puncture Tear Black Carbon Crack OIT Pressure OIT Thickness ASTH Resist- Resistance Content Black Resistance ASTH D SI99 D I505/ field Yield Break ance ASTH ASTH Dispersion ASTHD Standard ASTH ASTH Break High High Pressure Roll Width/ (min. avg.) D 792 Stress Elong- Elong- D4833 D 1004 D 1603 5397 OIT Manufacturer's Stress ASTH Pressure OIT D3695 D 5885 OIT (min. age.) Base FUymer Length mm (min.) kH/m ad'on ation (min. avg.) (rrm/avg.) range (%) D5596 Appendh ASTH ASTH % retained % retained % retained after 1600 Suggested kH/m (mils) [2] (g/on'mki) (b/h) kH(Ib) kNflbs) D3895 hrs [10] Applications [II] Product Name flWm) P] M D5885 after 90 days after 90 days

Agru/America Inc. www.agruamerica.com

A/A Liner HOPE 6.86/256 0.75 0.948 12 21 13 650 0.24 0.10 2-3 1,2.3 200 100 400 55 80 60 CLSIUSIC.LUIC. (22.5/840) (30) (66) (120) (54) (23) LPL. TL, DL, DP

A/A Liner S 6.86/198 1.0 0.948 IS 28 13 700 0.32 0.13 2-3 1.2.3 200 100 400 55 80 60 cumsiuuc. (22.5/650) (40) (88) (160) (") (30) LPL. TL. DL, DP

A/A Liner $ 6.86/128 1.5 0.948 23 42 13 700 0.29 2-3 1.2.3 200 100 400 55 80 60 CUILSIC.LL,LC ~**^ (22.5/420) (132) (240) (108) >(«) LPL, TL. DL, DP •

A/A Liner $ 6.86/98 2.0 0.948 30 56 13 700 0.64 0.27 2-3 1.2.3 200 100 400 35 80 60 cuiLsic,mc, (22.5/320) (80) (176) (320) (144) (60) LPL. TL. DL, DP

A/A Liner J 6.86/76 2.5 0.948 39 70 13 700 0.8 0.33 2-3 1.2.3 200 100 400 55 80 60 CLSIL,SIC,LL,IC. (22.5/250) (100) (220) (400) (180) (75) LPL. TL. DL. DP

[1] HOPE = High density poryettytene -T = tutored [4] Other methods such as D 4218 (imifBe forma) or [7] The manufacturer has the option to select either out of [II] a = Canal Gner DL = Din liner a = Coemuded -T = tenured micrainve methods are acceptable if an appropriate the OIT methods bsted to evaluate the antioiidant SIL = Surface impoundment finer LPL= leach pad S = Smooth correlation to D 1603 (tube furnace) can be established. content in the geomembrane. liner [2] Imest individual of 10 values [5] Carbon black dispersion for 10 different views: [8] It also b recommended to evaluate samples at 30 and SIC = Surface impoundment cover LC = landfill cover P] Machine direction (HD) and cross machine direction • minimum B of 10 in Categories 1 or 2 60 days to compare with the 90 day response. U. = Landfill liner Tl = Tunnel Ener (ID) average values should be on the basis of 5 test • aD 10 in Categories 1. 2. or 3 [9] The condition of the test should be 20 hr. UV cycle at 75 C DP = Decorative pond RP = Reserve pit specimens each direction [6] The yield stress used to calculate me applied bad for the foBowed by 4 hr. condensation at 60 C NP = Not provided by manufacturer • Tretd elongation calculated with a gage length of 33mm SP-HfJl test should be the manutatinra's mean vafae via [10] in resistance is based on percent retained value regardless KA = Hot applicable, per manufacturer • Break elongation calculated win a gage length of 50mm HQC testing. of the original HP-Oil value. Ig/iG^^^mfl^TOijSoVitaa-tJ.e'mo'rfjg w*™ GEOMEMBRANES/POLY ETHYL ENE/ HOPE f " SPS^f^i^ >

Geotechnical Fabrics Report * December 2001 MFG, Inc.

Calculation/Computation Set Cover Sheet Review Documentation

Title of Project: Job Number: Task: /ll/'Cr^L fert&Atdt. *4c.T/o*J S~544 5tt Title of Calculations: C?^0i**£:r'*3/?st/J£L X-/»-A5?/£ 'x/'V£x45/€ / /2&*iJey /*/'£S/&*J Calcuations By: Print Name . — , Date *UosJ r-i*>e4rtrtAj Signature _ J . s ^-/^^.^ 2oc>\ ^ytrsi \jrsi«40C~v,*^i Assumptions Checked By: Print Name Date (Senior Personnel) vj o l» w rr- ^Ku^K «— Signal ^^^^^_ r('+ Calculations Checked By: Print Name (/ Date

Signature /^ //. ^JL^ -r/^Af

The Reviewer's/Checker's comments have been discussed with the Reviewer/Checker, and all significant issues have been resolved. •Calculation Originator: Print Name Date

Signature • Reviewer/Checker: Print Name Date

Signature

Apprived By: Print Name Date (Principal Investigator or Project Manager: Signature

Reviewer/Checker Approval (Approval Notes: If calculation are only spot checked, do not require checking, or are assumed to be correct by experience or engineering judgement, it should be noted here.)

ion Number Date By: Checked By: Approval: 1 Date By: Checked By: Approval: E • i Subject Project No.. 5344 Task No.. Ry ^ P/~ Checked By. JfH?- V File No.. Date Date Sheet .of 3

'£o

TO

MFC, INC. It IcoidorCall NEBS CUSTt-M "printing service TOLL FREE 1-ePO8aB-65J7 WEBS Inc. P«°ibuiougli. NH 03J53. Rs!. l«n:Q Anchor Trench Depth and Run-out Length for 60 mil HOPE Geomembrane Liner

Variables: Description: t = 1.5 mm . thickness of geomembrane (60 mil HOPE) t = 0.0049 ft

°"allow = 2200 psi min allowable stress (60 mil HOPE) ^ 2 Callow = 316800 Ib/ft min allowable stress (60 mil HOPE)

dcs = 1.5 ft depth of cover soil

8U = 0 deg ... , — T-^TC. y !^s|c.. SL =(^>- "dejj = 30 deg angle of shearing resistance of soil Calculations: * -—•/£/£ &e& V- , of^h Equations: ,„ •• * "" IF=0

Tallow '* COS(B) = 1479.3 '' Ib/ft Taiiow * cos(B) = FUo + FLC + FLT - PA + PP s 5 2 =• 172.5 *^C/- * " .} Ib/ft Ori = dcs* Ya K = tan2 (45 - <|>/2) KA = 0.33 r /TT-rXjf ) A KP = 3 ^7rt"s&~$p~-——~-T\\ " Kp = tan2 (45 + <|>/2) T i~ fr * Tallow = 1559*- ^ Ib/ft ' allow "" * Callow

FUO = 0 LRO Ib/fT FUO = On * tan(5u) * LRO 2 FLO = 80.4 LRO Ib/ft FLo=an*tan(6J*LRO

FLT = 229.5 (5t-%s\ &j_~ \&* Ib/ft FLT =TBllow*sin(B)*tan(5L) 2 PA = 19.2 dAT + 57.5 dAT PA=(0.5*yAT*dXT-»-an)*(KA*dAT) ^^T 2 P = <0.5- -d .o,)- (*•„„, PP = 172.5 dAT + 517.5 dAT P to AI &iftf

Results:

Rearranging the equation (TaNow * cos(B) = FUo + FLo + FLT - PA + PP) results in the following:

2 1249.9 = 153.3 dAT + 450.0 dAT + 80.4 LRO

CT^ A dA/ + i" dAT + G! LRO

2 + 2 1 2 C2-A*dAT -B*dAT B .(B -4*A*(C1*LRO-C2)) ' -RO OAT 2*A Given ' Result Given Result

dAT W LBO (ft) LRO (ft) dAT (ft) 0.5 12.2 12.0 0.5 0.6 11.4 11.0 0.7 0.7 10.6 10.0 0.8 0.8 9.7 9.0 0.9 0.9 8.8 8.0 1.0 1 7.9 7.0 1.1 1.1 6.9 6.0 1.2 1.2 5.9 5.0 1.3 1.3 4.9 4.0 1.4 1.4 3.8 3.0 1.5 1.5 2.7 2.0 1.6 1.6 1.5 1.0 1.6

J:\5344\5344-50\geocalc Subject Project No.. Task No.. SO Checked By. File No.. Date \y Date Sheet 3 of 3

of? 7"//£T

/

MFC, INC. To flsadtr Call NEBS CUSTl-M"printIng servic* TOLL FREE 1.800-B8M327 A/£6S. die.. P««iOuraugh. NH 0«S3. Fourth Edition Designing with Geosynthetics

Robert M. Koerner, Ph.D., RE. H. L. Bowman Professor of Civil Engineering, Drexel University and Director, Geosynthetic Research Institute

PRENTICE HALL Upper Saddle River, New Jersey 07458 Sec. 5.3 Liquid Containment (Pond) Liners 491

where

•7"j,Dow = allowable force in geomembrane ='

The values of FUo, ¥Lo, and Fa have been defined previously. The values of PA and PP require the use of lateral earth pressure theory.

PA = \(yA7dAT)KAdAT + (

PA = (^yATdAT+^KAdAT (5.27)

PP = (0.5yAJdAT + ^KpdAT (5.28) where

yAT = unit weight of soil in anchor trench, dAT = depth of the anchor trench, °ii = applied normal stress from cover soil, 2 KA = coefficient of active earth pressure = tan (45 — <£/2), 2 KP = coefficient of passive earth pressure = tan (45 + <£/2), and j> = angle of shearing resistance of respective soil.

This situation results in one equation with two unknowns; thus a choice of either LKO or dAT is necessary to calculate the other. As with the previous situation, the factor of safety is placed on the geomembrane force T, which is used as an allowable value,T^ow- Example 5.14 illustrates the procedure.

Example 5.14 Consider a 1.5 mm thick HOPE geomembrane extending out of a facility as shown in Rg- ure 5.31. What depth anchor trench is needed if the runout distance is constrained to 1.0 m? In the solution, use a geomembrane allowable stress of 16,000 kPa on a 3(H) to 1(V) side slope. There are 300 mm of cover soil at 16.5 kN/m1 placed over the geomembrane runout and anchor trench (this is also the unit weight of the anchor trench soil). The fric- tion angle of the geomembrane to the soil is 30° (although assume 0° for the top of the geo- membrane under a soil-cracking assumption) and the soil itself is 35°. • t 490 1 Designing with Geomembranes Chap. 5

Geomembrane

Tcosp

FLT t t t t t t t t t

UU III

Figure 531 Cross section of geomembrane runout section with anchor trench and related stresses and forces involved.

be shown, this passive earth pressure is very effective in providing a resisting force (see Holtz and Kovacs [44]). Using the free-body diagram in Figure 5.31, . 2F, = 0

aiiow cos P = F (5.26T Sec. 5.1 Geomembrane Properties and Test Methods 439

TABLE 5.7 PEAK FRICTION VALUES AND EFFICIENCIES*

Soil-to-Geomembrane Friction Angles

Soil type

Concrete sand Ottawa sand Mica schist sand Geomembrane (0 = 30°) _(^=28°) ( = 26°)

HOPE (smooth) 18° (0.56) f "" 18° / (0.61) 17° (0.63) PVC rough 27° (0.88) ^— ' — — 25° (0.96) smooth 25° (0.81) — — 21° (0.79) CSPE-R 25° (0.81) 21° (0.72) -- 23° (0.87)

Geomembrane-to-Geotexttle Friction Angles

Geomembrane

PVC * ,. : *-*s=i HOPE Geotextile (smooth) Rough Smooth CSPE-R

Nonwoven needle-punched 8° 23° 21° 15° Nonwoven heat-bonded 11° 20° 18" 21° •&& Woven monofilament 6° 11° 10" 9° Woven slit-film 10° 28° 24° 13°

Soil-to-Geotextile Friction Angles

Soil type

Concrete sand Ottawa sand Mica schist sand Geotextile ( = 30°) (0 = 28°) (0 = 26°) Nonwoven needle-punched 30° (1.00) 26° (0.92) 25° (0.96) Nonwoven heat-bonded 26° (0.84) Woven monofilament 26° (0.84) Woven slit-film 24° (0.77) 24° (0.84) 23° (0.87) Jy : ••>.

*Efficiency values (in parentheses) are based on the relationship £ = (tan 5)/(tan )• Source: After Martin et al. [17] jp#$|jp The frictional behavior of geomembranes placed on clay soils is of considerable &•:•£&' importance for composite liners containing solid or liquid wastes. The current re- quirements are for the clay to have a hydraulic conductivity equal to or less than iip 1 X 10~7 cm/s and for the geomembrane to be placed directly upon the clay. While an indication of the shear strength parameters has been investigated (e.g., [18]), the data '$ are so sensitive to the variables discussed previously that site-specific and material-spe- tests should always be performed. In such cases, literature valuesjjgiu.ld never be } for final design purposes. Attachment C.2

Repository Excavation Slope Stability Analysis Appendix C.2

Repository Side Slope Stability Evaluation

Based upon infinite slope theory, the slope stability safety factor (SF) is defined by:

FS = tan O/tan I,

where: $ = angel of internal friction (soil) I = angle of the slope

Using an internal friction angle of = 30* for the alluvium, and a repository side slope of 3(H):1(V), the following safety factor against slope failure is obtained:

3(h):l(v) = .333 arctan 0.333 = 18.3'

FS = tan30Ytan 18.3' FS = 0.577/0.333 FS=1.7

In order to determine the overall sensitivity the slope stability has to different friction angles, a parametric analysis was performed to determine the respective safety factors for a given friction angle. The results of the parametric analysis are presented in the following table.

Internal Friction of Soil,) 3(H):1(V),I (degrees) tan (I) (tan

An internal friction angle of 30' is considered conservative for alluvial material classified as GW to GP. Allowing for soil inconsistencies of lesser shear strength than 30 degrees, the minimum internal friction value required to provide a safety factor greater than or equal to 1.5 is 26 degrees.

Even under what could be considered a worst case scenario, the factor of safety against slope failure exceed the acceptable safety factor considering the minimum shear strength value of 26 degrees. The results of the parametric analysis, and the slope stability evaluation as a whole, indicate that the factors of safety against failure for the anticipated conditions are favorable. APPENDIX D

TECHNICAL SPECIFICATIONS Issue for Agency Review

AV/CZLSITE-OU5 CALIFORNIA GULCH SUPERFUND SITE - LEADVILLE. COLORADO REMEDIAL ACTION TECHNICAL SPECIFICATIONS WITH CONSTRUCTION QUALITY CONTROL/QUALITY ASSURANCE

April 2005

Prepared/or: ASARCO INCORPORATED 495 East 51st Avenue Denver, Colorado 80216

Prepared by:

MFC, INC. 4900 Pearl East Circle, #300W Boulder, CO 80301 Phone: (303) 447-1823 Fax: (303) 447-1836 Revision No. 1 March 5, 2005

AV/CZL SITE - OU5 REMEDIAL ACTION

TECHNICAL SPECIFICATIONS WITH CONSTRUCTION QUALITY CONTROL/QUALITY ASSURANCE

Specification Number Description 01010 Summary of Work 01060 Regulatory Requirements 01300 Submittals 01505 Mobilization, Preparatory Work and Demobilization 01510 Temporary Construction Utilities and Facilities 01548 Preservation of Historical and Archeological Features 02130 Surface Water Control During Construction, 02200 Earthwork 02215 Structure Demolition and Management of Demolition Debris 02610 Pipe and Fittings 02270 Geosynthetic Liner Systems 02900 Vegetation Establishment- Seeding Revision No. 1 March 5, 2005

SECTION 01010 SUMMARY OF WORK

PARTI GENERAL

1.1 DESCRIPTION

A. This section includes a general summary of the work to be performed under this Contract, as part of the remedial action activities for the AV/CZL Site, Operable Unit 5 of the California Gulch Superfund Site in Leadville, Colorado (the Site). This work is being conducted in accordance with a Record of Decision (ROD) issued by the United States Environmental Protection Agency (EPA) in September, 2000. The general work activities to be completed under this Contract include, but are not limited to the following: smelter structure demolition, surface regrading, installation of a lined repository and composite-layer cover system, revegetating the capped surfaces, and construction of water diversion ditches to provide surface water run-on and run-off control.

1.2 RELATED SECTIONS

A. All Contract Documents

1.3 SCOPE OF WORK

A. The project consists of the remediation of the AV/CZL Site in Leadville, Colorado. The general scope of work includes, but may not be limited to the following:

1. Prepare a site-specific Health and Safety Plan (HASP) in accordance with specific requirements of 29 CFR 1910.120 and general requirements of 29 CFR 1910 and 1926;

2. Mobilize and prepare for the Work including installation of all temporary facilities;

3. Install and maintain temporary sediment, diversion and stormwater control structures in accordance with the Storm Water Management Plan (SWMP) and maintain such controls during construction activities;

4. Provide dust control, as necessary, during all excavating, hauling and placing operations;

5. Demolish smelter structures indicated for removal on the Drawings and relocate two large above ground storage tanks;

6. Excavate flue dust from areas indicated on the Drawings;

7. Screen flue dust materials to remove materials greater than 2 inches in any dimension, stockpile and cover the flue dust prior to placement into the repository;

Summary of Work

J:\BLDOI\5344\5344-50\AV_CZL DESIGN\FINALAAV.CZLSPECS REV1.DOC 01010-1 Revision No. 1 March 5,2005

8. Excavate the repository as indicated on the Drawings, and install multi-layer bottom liner system which includes a geomembrane sandwiched in between two layers of geotextile;

9. Place and compact flue dust materials into the repository;

10. Install repository top liner system;

11. Excavate, consolidate and compact non-residential area soils and tailing to the lines and grades shown on the Drawings;

12. Place an 18-inch soil cover, over the consolidated non-residential area soils and tailing as indicated on the Drawings;

13. Construct permanent diversion ditches, with appropriate erosion protection to provide surface water run-on and run-off control, and install approximately 200 foot long drainage culvert pipe;

14. Revegetate the excavated areas, cover soil areas, and other disturbed areas; and

15. Perform site cleanup and demobilize.

1.4 ADDITIONAL REQUIREMENTS OF CONTRACTOR

A. In the conduct of the construction work described above, Contractor shall:

1. Comply with terms of all permits required for the Work; and

2. Comply with all applicable local, State and Federal health and safety rules and regulations.

END OF SECTION

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SECTION 01060 REGULATORY REQUIREMENTS

PARTI GENERAL

1.1 CODES

A. Contractor shall comply with the most recent edition of all codes and regulations of applicable regulatory authorities, including:

1. Colorado Department of Public Health and Environment (CDPHE) regulations;

2. U.S. Environmental Protection Agency (EPA) regulations;

3. Applicable Occupational Safety and Health Administration (OSHA) regulations;

4. Applicable Mine Safety and Health Administration (MSHA) regulations;

5. State of Colorado and Federal Department of Transportation regulations; and

6. Applicable Lake County and City of Leadville regulations and ordinances.

B. In the event of conflicts between the requirements of various codes and regulations, Contractor shall comply with the more stringent code or regulation.

END OF SECTION

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SECTION 01300 SUBMITTALS

PARTI GENERAL

1.1 DESCRIPTION

A. This section describes the requirements for all submittals associated with and required by the Project. The submittals include a Work Plan, Health and Safety Plan, construction progress schedules, material certifications, samples and test results.

1.2 RELATED SECTIONS

A. All Sections

1.3 GENERAL SUBMITTAL REQUIREMENTS

A. Transmit each submittal to the Company's Representative. Submit the number that the Contractor requires, plus three copies to be retained by the Company and Company's Representative.

B. Sequentially number the transmittal forms. Re-submittals will have original number with an alphabetic suffix for clarity and identification.

C. Each submittal shall include a statement certifying that review, verification of products required, field dimensions, procedures and coordination of information, is in accordance with the requirements of the Contract Documents.

1.4 WORK PLAN

A. Within 10 days after receipt of Notice of Award, Contractor shall submit a brief Work Plan that will contain the following:

1. Plans for Mobilization, Preparatory Work and Demobilization as described in Section 01505.

2. Plans for Temporary Construction Utilities and Facilities as described in Section 01510.

3. Plans for demolition, excavation, processing, repository construction, fill placement, and soil cover installation as described in Sections 02200, 02215 and 02770.

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1.5 HEALTH AND SAFETY PLAN

A. Within 10 days after receipt of Notice of Award, Contractor shall submit a site specific Health and Safety Plan (HASP) that includes a construction safety program. The HASP shall be in accordance with provisions in 29 CFR 1910.120; other federal, state, and local regulations; and Contractor guidelines. The HASP shall be submitted and reviewed by the Company's Representative prior to the start of the project. Also, as part of the contractor safety program, the Contractor shall establish the procedure for the immediate removal to a hospital or doctor's care of any person who may be injured on the job site, in concert with the Company's internal program.

B. The duty of Company or its Representative to conduct construction review of the Contractor's performance is not intended to include a review or acceptance of the adequacy of the Contractor's safety supervisor, the safety program, or any safety measures taken in, on, or near the construction site.

C. All workers on site must comply with the training requirements of OSHA requirements contained in 29 CFR 1910.120.

1.6 CONSTRUCTION PROGRESS SCHEDULES

A. Submit initial schedule within ten (10) days after Notice of Award. The schedule shall be shown in weekly increments at a minimum.

B. Submit revised schedules bi-weekly.

C. Show complete sequence of construction by activity identifying work of separate stages and other logically grouped activities.

END OF SECTION

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SECTION 01505 MOBILIZATION, PREPARATORY WORK AND DEMOBILIZATION

PART 1 GENERAL

1.1 DESCRIPTION

A. This specification covers the requirements for mobilization, preparatory work, temporary facilities, and demobilization. Sediment control facilities are specified in Section 02130.

1.2 RELATED SECTIONS

A. Section 02130 - Surface-Water Control During Construction

B. Section 02200 - Earthwork

1.3 MEASUREMENT AND PAYMENT

A. There will be no measurement for payment of mobilization and demobilization costs.

B. Payment will be made at the lump sum price shown in the Bid Schedule, and shall be full compensation for all mobilization, site access, preparatory work, temporary facilities, site cleanup and demobilization. Sixty percent of the amount bid against this item will be paid with the first progress claim, and the remaining forty percent will be paid following site cleanup and demobilization.

PART 2 PRODUCTS AND EQUIPMENT

A. Contractor shall utilize appropriate and sufficient products and equipment in the conduct of all preparatory work and the establishment of all temporary facilities, consistent with the nature and requirements of the project and the health and safety of workers and the public.

B. Use water trucks and/or approved dust suppressants on haul roads, as necessary during hauling operations.

C. Haul trucks and equipment shall be properly maintained to avoid excessive noise during hauling operations through the City of Leadville, if required.

D. Use appropriate "Truck Crossing" or "Trucks Turning" signs on public roads, where required at work areas.

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PARTS EXECUTION

3.1 MOBILIZATION

A. Following receipt of the Notice to Proceed, Contractor shall mobilize to the Site all personnel, materials, equipment, and construction facilities necessary for the proper performance of the Work.

3.2 INSTALLATION OF FACILITIES

A. All preparatory work and installation of temporary facilities shall be done in accordance with applicable codes and regulations.

3.3 SITE SECURITY AND TRAFFIC CONTROL

A. Contractor shall provide temporary fencing, gates, and signs, as necessary, to limit public access to the Site and shall be responsible for the safety of all individuals engaged in remedial activities on the Site. Perimeter fencing of the Site is not required.

B. Contractor shall conduct its operations so as not to significantly interfere with the normal flow of traffic on local roads near the Site. Where required by the City of Leadville, Lake County or State of Colorado regulations, flag persons and signage shall be provided to ensure public safety.

C. Haul trucks on the site shall be limited to speeds of 15 mph.

3.4 MAINTENANCE AND PROTECTION OF EXISTING DRAINAGEWAYS

A. Contractor shall take all necessary precautions to limit disturbance to natural drainageways in the vicinity of the Work, and shall install temporary culverts and other drainage works, as required, to maintain drainageways during construction.

B. Contractor shall control erosion along temporary access roads and all Work areas as specified in Section 02130.

3.5 STAGING AREA, SITE ACCESS AND HAUL ROADS

A. Contractor may utilize portions of the AV/CZL site as a staging area for equipment or material storage. Staging areas shall be approved by Company's Representative.

B. Primary access to the Work areas will be from Highway 24 along the southern boundary of the Site. Contractor shall upgrade, as necessary, and maintain the existing access road from Highway 24.

C. Identification of the borrow area is pending. Access to the borrow area will be identified on a drawing that will be distributed during the bid process

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D. Minimize disturbance to existing streams and vegetation in the construction and maintenance of all access roads.

E. Contractor shall properly maintain all access and haul roads necessary for the conduct of the Work. Upon completion of construction, all temporary access and haul roads shall be removed and regraded, as required. Immediately remove all spilled or tracked materials from public roads. Contractor shall repair any damage to permanent roads and bridges, directly caused by its activities, and restore them to a condition equal to or better than that found at the outset of the proj ect. ,

F. Contractor shall comply with all posted load limits for local roads and bridges used in transporting materials.

G. Contractor shall apply water and/or approved dust suppressants to access roads between the work areas, if necessary.

3.6 SITE MAINTENANCE

A. Contractor shall keep the Site free from any unnecessary accumulation of waste materials and rubbish and shall maintain the Site in a safe and tidy condition at all times.

3.7 CLEANUP AND DEMOBILIZATION

A. Following completion of the Work, Contractor shall thoroughly clean all equipment that has come into contact with flue dust, non-residential area soils, or tailing, and remove from the site all equipment, materials and temporary facilities not incorporated into the Work.

B. Remove temporary culverts at the end of construction activities as applicable, and restore areas, as directed.

C. Waste materials, debris and rubbish generated by the Contractor shall be properly collected and disposed of offsite, in accordance with local, state, and federal laws and regulations.

D. Contractor shall leave all areas of the Site in a clean, stable condition.

END OF SECTION

Mobilization, Preparatory Work and Demobilization

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SECTION 01510 TEMPORARY CONSTRUCTION UTILITIES AND FACILITIES

PARTI GENERAL

1.1 DESCRIPTION

A. This section describes the requirements for temporary construction utilities and facilities required by the Project. These include but are not limited to water service, electric power, telephone service, sanitary facilities and office space.

1.2 RELATED SECTIONS

A. Section 01300 - Submittals

B. Section 01505 - Mobilization, Preparatory Work and Demobilization

1.3 MEASUREMENT AND PAYMENT

A. There will be no separate payment for work associated with temporary construction utilities and facilities. This work will be included under Mobilization, Preparatory Work, and Demobilization.

B. Contractor will be responsible for all costs and fees associated with the connection and use of temporary utilities including water, electric, and phone.

PART 2 PRODUCTS

2.1 TEMPORARY WATER

A. Potable water for use by the Contractor is not available at the Site.

B. Water for dust control and for moisture control for compaction will be procured and provided by the Contractor.

C. Temporary water line installation, if necessary, shall meet the requirements of all governing agencies.

2.2 TEMPORARY ELECTRIC POWER

A. Temporary electric service shall be established by the Contractor.

B. Temporary electric power installation shall meet the requirements of all applicable codes and regulatory agencies.

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2.3 TEMPORARY TELEPHONE SERVICE

A. Temporary phone service shall be established by the Contractor if necessary. Installation shall meet the requirements of all applicable codes and regulatory agencies.

2.4 SANITARY FACILITIES

A. Contractor shall provide temporary sanitary facilities at the Site for all work crews and Company's Representative.

2.5 OFFICEfTESTING TRAILER

A. Contractor shall provide an office trailer at the Site for daily use with a dedicated office area for the use of the Company's Representative.

PART 3 EXECUTION

3.1 PRODUCT DELIVERY

A. Schedule delivery of products or equipment as required to allow timely installation and to avoid excessive on-site storage. Limited outside storage is available. No inside storage is available.

B. Delivery of products or equipment to be in manufacturer's original unbroken cartons or other containers, clearly and fully marked and identified as to manufacturer, item, and instructions for assembly, use and storage.

C. The Contractor shall inspect all products or equipment delivered to the site prior to their unloading and shall reject all products or equipment that are damaged, used, or in any other way unsatisfactory for use on project.

3.2 STORAGE AND HANDLING

A. Store products or equipment off the ground and protected from weather. Provide additional protection as required by manufacturer until the time that the item is to be installed. While storing, take care to avoid damage from water or humidity.

B. Store products or equipment in location to avoid physical damage to items while in storage, and to facilitate prompt inspection.

C. Handle products or equipment in accordance with manufacturer's recommendations and instructions.

D. Delicate instruments and materials subject to vandalism or theft shall be placed under locked cover and, if necessary, provided with temperature control as recommended by manufacturer.

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END OF SECTION

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SECTION 01548 PRESERVATION OF HISTORICAL AND ARCHAEOLOGICAL FEATURES

PARTI GENERAL

1.1 RELATED SECTIONS

A. Section 02200 - Earthwork

1.2 LEGISLATION

A. State and Federal legislation (Public Law 93-291) provides for the protection, preservation, and collection of scientific, prehistoric, historic, and archaeological data (including relics and specimens) that might otherwise be lost due to alteration of the terrain as a result of any construction project.

1.3 CHANGES TO THE CONTRACT TIME AND/OR PRICE

A. Where appropriate, by reason of an historic or archaeological discovery, the Company or its Representative may order delays or alterations in the Project Schedule, or changes in the Work, or both. Where such delays, alterations or changes are ordered, the Company may adjust the time of performances and/or the Contract Price in accordance with the applicable clauses of the Contract.

PART 2 PRODUCTS

2.1 MATERIALS

A. The Contractor shall use appropriate and sufficient materials to preserve historical and archaeological data, as required, or as directed by the Company's Representative.

PART 3 EXECUTION

3.1 COMPLIANCE

A. If the Contractor, Contractor's employees and/or subcontractors, in the performance of this Work, discover evidence of possible scientific, prehistoric, historic, or archaeological data, the Company or its Representative shall be notified immediately of the location and nature of the findings, and written confirmation shall be forwarded within two days. Contractor shall exercise care so as not to damage artifacts, fossils or other evidence uncovered during construction operations. Contractor shall provide such cooperation and assistance as may be necessary to preserve the findings for removal or other disposition by the Company. Title to materials found on the site will reside with the Company or landowner.

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B. Contractor agrees to insert Paragraph 3.1 A in all subcontracts which involve the performance of Work on the Site.

END OF SECTION

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SECTION 02130 SURFACE WATER CONTROL DURING CONSTRUCTION

PARTI GENERAL

1.1 DESCRIPTION

A. This specification section covers the requirements for dewatering the work areas and controlling surface water and sediment during construction at the Site.

1.2 RELATED SECTIONS

A. Section 01505 - Mobilization, Preparatory Work and Demobilization

B. Section 02200 - Earthwork

1.3 QUALITY CONTROL

A. Dewatering, as necessary, shall be conducted in such a way that it does not result in the release of excessive sediments or tailing from the Work areas into any tributary drainageways.

B. Contractor shall control the rate of any dewatering so as to avoid any objectionable settlement, subsidence, or instability of adjacent areas and to assure the integrity of the finished Work.

C. Contractor shall be fully responsible for complying with all provisions of the applicable Colorado stormwater control regulations regarding dewatering during all Work at the site, and shall comply with the requirements of the construction Storm Water Management Plan (SWMP).

1.4 SUBMITTALS

A. Contractor shall submit information on materials and methods proposed for drainage and sediment control measures at the Site at least five (5) days prior to commencing Work.

1.5 MEASUREMENT AND PAYMENT

A. There shall be no measurement for payment for construction of run-on/runoff control berms, sedimentation pond, dewatering or control of surface water during construction at the Site. All costs for this Work shall be included in, and payment will be made at, the rates provided by the Contractor on the Bid Schedule, for dewatering and surface water control during construction. Payment shall include maintenance of all stormwater and erosion control facilities.

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PART 2 EQUIPMENT AND PRODUCTS

2.1 , EQUIPMENT

A. Contractor shall ensure that sufficient pumping equipment, piping and other appropriate materials are available on site, prior to commencement of work, such that any dewatering operation can be continuously maintained. All equipment shall be of good quality and in good working order. * 2.2 MATERIALS

A. ' Hay bales, silt fences, or other materials used to control erosion and sediment transport from excavations and other work areas shall be new and appropriately sized to serve the intended purpose.

B. Use certified weed-free hay bales.

C. Use 30- to 36-inch high silt fences including slats for stability.

D. Riprap used for sedimentation control or temporary diversion structures shall be as specified in Section 02200.

E. Provide submersible pump and portable tank or vacuum truck for leachate collection and transportation.

PART 3 EXECUTION

3.1 DEWATERING METHODS

A. Contractor shall perform dewatering, as necessary, during all construction at the site, such that water levels are maintained below the bottom of excavations.

B. Contractor shall select methods of dewatering and arrangement of related piping systems that minimize direct discharges to adjacent streams, and do not cause erosion or instability of the work site or adjacent areas.

3.2 STORM WATER CONTROL BERMS & SEDIMENTATION POND

A. Contractor shall construct run-on and runoff control berm a minimum of 6 inches high around each flue dust excavation area and around the flue dust stockpile and processing area.

B. Contractor shall construct a sedimentation pond immediately downgradient of the flue dust stockpile and processing area as shown on the Drawings.

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C. Remove stormwater from sedimentation pond periodically or as necessary to maintain adequate rainfall storage capacity. Use removed water as a compaction aid during flue dust placement or relocate stormwater to the Yak Tunnel Treatment Plant.

3.3 SEDIMENT CONTROL AND DIVERSIONS

A. Provide sedimentation control downstream of the Work as required by the Drawings, Construction SWMP, and as directed, to prevent excessive sediment.Ioading to the streams.

B. Install silt fences with suitable posts and proper anchorage along the entire length of the silt fence, in accordance with the manufacturer's recommendations, and as shown on the Drawings.

C. Remove and dewater silt or sediment buildup behind silt fences as necessary during construction and near the end of the Work.

D. Maintain the diversion ditches, berms and sediment control structures throughout the performance of the Work, as necessary.

3.4 LEACHATE COLLECTION AND REMOVAL

A. Immediately prior to installation of flue dust repository top liner, remove all leachate from the flue dust repository sump via the leachate collection.

B. Transport leachate to the Yak Tunnel Treatment Plant for inclusion in the process stream.

C. Cut off, plug and abandon leachate collection system riser pipe a mimimum of 12 inches below surrounding grade to prevent penetration of the top liner.

END OF SECTION

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SECTION 02200 EARTHWORK

PARTI GENERAL

1.1 DESCRIPTION

A. This section describes the requirements for all earthwork associated with and required by the Project. Earthwork includes excavation, hauling of materials, regrading, placement and compaction of fill, placement of rock riprap and geotextile materials under riprap and final grading.

1.2 RELATED SECTIONS

A. Section 01300 - Submittals

B. Section 01505 - Mobilization, Preparatory Work and Demobilization

C. Section 02130 - Surface Water Control During Construction

1.3 MATERIAL CLASSIFICATION

A. The term earthwork applies to all tailing, demolition debris, soil, or rock riprap materials placed, excavated or removed regardless of material characteristics.

1.4 SUBMITTALS

A. Contractor shall submit manufacturer's data on geotextiles and other materials provided by the Contractor, at least five working days prior to beginning the portion of the Work to which the item applies.

B. Contractor shall submit earthwork material source and other information required for fill soils, riprap and other materials, as necessary.

1.5 SAFETY

A. Contractor shall shore, brace, or slope excavations, as necessary, in accordance with OSHA regulations to ensure worker safety, and to protect property from damage during construction.

B. Contractor shall comply with the applicable occupational safety and health requirements of OSHA.

C. Contractor shall exercise particular caution during excavation, handling and placement of tailing, non-residential area soils, slag and other debris which may exhibit elevated concentrations of lead, arsenic and other metals and could present a potential health hazard to Contractor's site personnel, if not properly protected.

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D. Contractor shall be fully responsible for the health and safety of all personnel on the Project Site, at all times, and shall take all necessary precautions to protect such health and safety.

E. Contractor shall provide first aid materials and equipment at the Site, as necessary, and shall coordinate with local medical facilities and identify local emergency phone numbers to supplement job site safety and first aid.

F. Contractor shall comply with the requirements of the Site Health and Safety Plan, and its own site-specific Health and Safety Plan.

1.6 DUST AND SEDIMENT CONTROL

A. Contractor shall take adequate precautions to avoid dust emission resulting from earthwork.

B. Contractor shall control release of sediment from excavated areas to limit sediment loading to tributary drainageways as specified herein and in Section 02130, and as required by the Stormwater Management Plan (SWMP).

1.7 MEASUREMENT AND PAYMENT

A. Measurement of earthwork quantities will be made based on field surveys. The Contractor will employ the services of an independent, third party, surveyor (licensed in the State of Colorado and approved by the Company) to perform surveying and measurement of the earthwork. The methods utilized by the surveyor to measure earthwork quantities will be capable of comparing the pre- and post- activity surfaces and calculating the net volume change.

B. Payment for excavation, screening, hauling, placement and compaction of the flue dust and excavation and preparation of the repository subgrade shall be based on the final in-place volume of material in the repository. The final in-place volume shall be calculated by the third party surveyor as the net fill based on its survey of the excavated repository foot print prior to material placement and its survey of the final top surface after all flue dust materials have been placed and compacted. Payment will be made at the unit price per cubic yard in the Bid Schedule.

C. Payment for excavation, size reduction, hauling, placement, compaction and grading of the non-residential soil, tailing and demolition debris shall be based on the final in-place volume of these materials relocated to the soil cover areas. The final in-place volumes shall be calculated by the third party surveyor as the net fill based on its surveys of the soil cover areas prior to material placement and its surveys of the final top surfaces (following final compaction and prior to placement of the cover soil layer). For the AV Smelter, the volume of non-residential soil and tailing calculated in this manner shall be decreased (minus) by the volume of material in the flue dust repository calculated in item C. above. Payment will be made at the unit price per cubic yard in the Bid Schedule.

D. Payment for supply, placement and grading of the cover soil over the non-residential soil demolition debris and tailing shall be based on field surveys of the actual area covered at the

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designed depth (eighteen inches). Payment will be made at the prices per square yard provided by the Contractor on the Bid Schedule.

E. Measurement of riprap placed will be of the square yards placed, by type and thickness. Payment will include supply and placement of riprap and underlying geotextile and grouting as applicable. Payment will be made at the prices per square yard provided by the Contractor on the Bid Schedule.

F. Payment for construction of the run-on and run-off control ditches shall be based on the lineal footage of the ditch as measured along the final center line. Payment will be made at the unit price per lineal foot in the Bid Schedule.

G. No extra payment will be made for control of dust, erosion, or sediment control during earthwork operations.

H. No measurement of geotextile, hay bales, rock or riprap shall be made for temporary sediment control facilities, removal of sediment or removal of sediment control or diversion facilities. This work will be included under Mobilization, Preparatory Work and Demobilization (Section 01505), or under Surface Water Control during Construction (Section 02130).

I. No extra payment will be made for minor earthwork required for access at the site. This work will be included under Mobilization, Preparatory Work, and Demobilization (Section 01505).

J. The removal of old rail ties, scrap metal, empty drums, wire, rail, trees/stumps, or any other items which are necessary for the excavation work are considered incidental to the work - no additional payment will be allowed for these items.

K. No extra payment will be made for shoring, temporary cribbing or sheeting required for excavation. This work will be included under the respective bid items for excavation.

1.8 QUALITY CONTROL

A. Contractor shall use an adequate number of skilled workers experienced in the type of work to be performed.

B. Contractor shall employ the services of an independent, third party, subcontractor acceptable to the Company to perform quality control testing for earthwork as specified herein. Company or Company's Representative may perform periodic quality assurance testing.

C. Contractor shall perform nuclear densometer instrument testing of the repository foundation and the compacted flue dust placed within the repository and consolidated non-residential area soils and tailing in accordance with ASTM D2922 or sand-cone testing in accordance with ASTM D1556 to confirm in-place compacted density and moisture of fill materials as compared with ASTM D698 (Standard Proctor Compaction Curve). The repository foundation shall be tested at a frequency of at least one test per 2000 square feet (sf). The flue dust materials placed within the repository shall be tested at a frequency of at least one test per 500 cubic yards (cy) of compacted material, or one test for each lift of material compacted in

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the repository area, whichever is greater. The non-residential area soils/tailing shall be tested at a frequency of at least one test per 3000 cy of compacted material. Any area that fails to meet the compaction acceptance criteria shall be reworked until a subsequent test shows acceptable results.

D. Contractor shall perform mechanical sieve analysis of processed flue dust materials per ASTM D422 at a frequency of at least one test per 1000 cy of material placed in the repository.

E. Contractor shall use grade stakes to demonstrate achievement of the minimum required cover soil thickness. Grade stakes shall be placed with a minimum density of 1 stake per 10,000 square feet (100 ft x 100 ft grid).

F. Contractor shall perform construction surveys, as needed, to ensure that the lines and grades of all excavations, embankments, ditches, covers, riprap layers, and graded surfaces are in accordance with the design requirements.

G. The Company's Representative will perform periodic quality assurance monitoring. Contractor shall cooperate, as required, in quality assurance monitoring.

H. The dimensions and grades of all regraded surfaces, and diversion ditches and channels, shall be verified by survey, prior to the placement or installation of any geosynthetics, cover soil, or riprap.

PART 2 PRODUCTS

2.1 COVER SOIL

A. Contractor shall use the designated borrow area, indicated on the Drawings for the soil cover to be placed over the regraded surfaces. Available data on the borrow area will be distributed during the bidding process.

B. Borrow soil used for the soil cover shall be screened, as necessary to remove rocks over 3 inches in diameter.

2.2 NON-RESIDENTIAL AREA SOILS^TAILING

A. All excavated soil materials surrounding the AV Smelter and CZL Mill sites excluding the flue dust materials at the AV Smelter and tailing at the AV Smelter Site and at the CZL Mill site comprise the non-residential area soils.

B. Non-residential soils will include but not be limited to soils containing residual smelter materials, and soils containing miscellaneous materials surrounding the AV Smelter and CZL Mill site.

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C. All excavated soil materials surrounding the AV Smelter and CZL Mill sites excluding the flue dust materials at the AV Smelter and non-residential area soils at the AV Smelter Site and at the CZL Mill site comprise the tailing.

2.3 FLUE DUST MATERIALS

A. All excavated materials from the flue dust removal areas identified on Drawing 534451C-104 less than 2 inches in any dimension comprise the flue dust materials.

B. Flue dust materials will include but not be limited to fine-grained materials contained within the matrix of the material excavated.

C. Flue dust materials will be separated from particle fragments larger than 2 inches by screening.

D. Screened flue dust materials will be stockpiled near the repository. No flue dust will be placed in the repository until all flue dust material excavated has been screened and the volume estimated by the Contractor's third party surveyor.

E. Flue dust stockpiles shall be protected by secure covers at all times.

2.4 ROCK FOR RIPRAP

A. Rock for riprap for use in run-on and run-off control ditches shall be a sound, dense angular rock which is resistant to weathering and is free from large quantities of soil, shale and organic matter.

B. Riprap shall have a dry specific gravity of at least 2.6. It shall contain no flat or elongated rocks, with the greatest dimension no more than 3 times the least dimension. The rock shall be well graded from 3 to 12 inches with D50 greater than 7 inches. Contractor shall identify acceptable sources for the riprap.

C. Oversize rock generated from screening operations in the Borrow Area, greater than 3-inches in diameter may be used for the drainage ditches provided specifications 2.4 paragraph A and 2.4 paragraph B are met.

2.5 GRAVEL ROAD BASE

A. If directed by Company's Representative, use a minus 3/<-inch untreated road base material (Class 6) for re-surfacing the existing dirt roads as specified in the Colorado Transportation Department Standard Specifications for Highway Construction.

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2.6 GEOTEXTILE MATERIALS

A. Geotextile for use beneath riprap in the water diversion drainage ditches shall be a non-woven polyester or polypropylene material having a weight of 8 ounces per square yard as shown on the Drawings, and a flow rate of at least 70 gallons/minute/square foot when tested in accordance with ASTM D4491.

B. Geotextile for silt fences shall be woven polypropylene material having a UV resistance of at least 90 percent when tested in accordance with ASTM D4355, and shall have slats for stability during windy periods.

PARTS EXECUTION

3.1 DEMOLITION AND PLACEMENT OF DEMOLITION DEBRIS

A. Structures identified on Drawing 534451C-102 shall be demolished using mechanical equipment and/or expansive (non-explosive) demolition products. Explosives shall not be used in the demolition of these concrete foundations.

B. Specific details associated with building structure demolition and material handling is discussed in Section 02215 - Structure Demolition and Management of Demolition Debris.

3.2 EXCAVATION

A. Prior to initiating the excavations, all storm water controls specified in Section 02130 and the Construction Stormwater Management Plan, including silt fencing and hay bale check dams, shall be installed downstream of the work areas to minimize soil erosion from the excavated areas.

B. Contractor shall conduct excavation operations in a manner that will allow continued free drainage of the excavation and the immediately surrounding areas, to the extent possible. Excessive water shall not be permitted to accumulate in excavations. Perform all necessary pumping required to maintain excavations in a dewatered condition. Any water that may accumulate in excavations may be pumped and discharged at the surface.

C. Flue dust, soil and miscellaneous materials shall be removed from the bag house, ore house and flue areas as identified on Drawing 534451C-104 and as directed by the Company's Representative. These materials shall be relocated to the central processing area for eventual inclusion in the repository after larger debris fragments (greater than 2 inches) have been removed. Once the initial excavation depths shown on the Drawings are achieved and all visible materials have been removed to the Company's Representative's satisfaction, removal confirmation samples will be collected from the base of the excavations by the Company's Representative.

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If the arsenic or lead concentration in the soils exceeds the respective removal confirmation level in any decision unit, an additional one foot of materials will be excavated and the process repeated until the confirmation level is achieved. In the removal areas, excavations will be terminated if large concrete foundations are encountered. In addition, in the bag house area, excavations will be terminated if the underlying slag layer is reached.

D. Power equipment and hand tools shall be used to excavate the flue dust materials. Materials shall be transported from the excavation areas to the central processing area by trucks following designated haul routes. Any materials spilled during loading and transport and the immediately underlying soil shall be immediately excavated and transported to the central processing area.

E. Flue dust material shall be screened to remove materials larger than 2 inches and consolidated into one, uniformly shaped, stockpile until all flue dust materials have been excavated and screened. Temporary tarpaulins shall be used to securely cover the stockpile at all times. All flue dust material is to remain in the stockpile until the repository has been excavated and lined and is ready to accept the repository materials.

F. Once all of the flue dust has been consolidated into an uniform stockpile, the stockpile will be surveyed by the owner's representative in order to estimate the total volume. Once the volume has been determined, the repository shall be excavated.

G. The flue dust repository shall be excavated to the lines and grades shown on Drawings 534451C-107 and C-3 01, however, if the actual quantity of flue dust material is less than or greater than the as designed capacity, the actual limits of excavation will be modified accordingly to accommodate the reduction or addition of unforeseen materials. The repository shall be excavated to within a tolerance of ± 0.1 feet of the final control point coordinates.

H. Drainage ditches, shall be excavated to the lines and grades shown on the Drawings, and temporary culverts and access ramps shall be used, as required, where ditches cross existing drainageways.

I. Excavation, control of sediment, and restoration in the designated borrow area shall be performed in accordance with the requirements of Sections 02130 and 02900 of these specifications.

J. ' Non-residential area soils/tailing shall be excavated from the areas indicated in the Drawings and relocated and consolidated within the cover soil areas for proper placement and grading. Excavation of these materials shall include the excavation of surface soil down to the depths indicated on Drawings 534451C-104 and C-105.

K. Grade stakes shall be used to demonstrate that the initial excavation depths for the general areas shown on the Drawings are achieved. Further excavation of these areas may be required following the initial removals based on arsenic and lead concentrations in the bottom of the excavated areas as determined by the Company's Representative

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3.3 PROOF ROLLING AND SUBGRADE PREPARATION

A. Proof roll and compact repository subgrade and side slopes using a smooth drum vibratory roller compactor with a minimum operating weight of 20 tons.

B. The repository floor shall be compacted to at least 92 percent of the materials maximum dry density as determined by the Standard Proctor Test (ASTM D-698).

C. The repository side slopes shall be proof rolled and inspected for deflection. Areas deflecting more than 2 inches shall be excavated, replaced with imported borrow soil, compacted and retested.

3.4 LEACHATE COLLECTION SYSTEM

A. Install leachate collection system in sump portion of repository as shown on the Drawings.

B. Leachate collection system shall consist of a five foot long horizontal perforated drain pipe (4- inch diameter) wrapped in geotextile and placed directly on top of bottom liner. Horizontal drain pipe shall be connected by tee to vertical riser (4-inch diameter) which extends to the top of the flue dust. Support and install plug or slip cap over open end of riser during material placement.

3.5 COMPACTED FLUE DUST MATERIALS

A. Construction equipment having a ground pressure of less than 5 pounds per square inch (psi) shall be used to transport the flue dust into the repository.

B. Prior to the placement of flue dust materials into the lined repository, a ramp shall be constructed to protect the geomembrane liner from excessive wear generated by the construction equipment.

C. Once an acceptable access ramp into the repository has been constructed, flue dust materials can be placed, spread and compacted. The initial lift shall always be advanced ahead of the equipment such that the equipment is never in contact with the liner system.

D. The flue dust materials shall be placed in loose lifts of 8 to 12 inches and compacted to at least 92 percent of the maximum dry density as determined by the Standard Proctor Test (ASTM D-698). Water shall be added to the material, as necessary, to achieve proper compaction. Moisture content of the flue dust material shall be maintained within optimum and 3 percent dry of optimum.

3.6 COMPACTED NON-RESIDENTIAL AREA SOIL/TAILING MATERIALS

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A. Prepare the existing surfaces upon which compacted non-residential area soils/tailing will be placed, by grading the surfaces so that no irregular depressions or projections exist to achieve an acceptable surface upon which the additional material can be spread and compacted.

B. Excavated non-residential area soils/tailing shall be placed and compacted to the lines and grades shown on the Drawings, or as directed in the field. Placement of non-residential area soils/tailing shall only be done on properly prepared surfaces including existing ground surfaces, demolition debris materials, and non-residential area soils/tailing. Non-residential area soils/tailing shall be placed in horizontal layers approximately 8 to 12 inches in loose thickness. The minimum compaction requirements for all compacted non-residential area soils/tailing shall be at least 90 percent of the laboratory maximum dry density (MDD) as determined by the Standard Proctor Density Test (ASTM D698). Water shall be added, as necessary, to each layer of fill and the material blended prior to compaction. Wet areas shall be spread and air dried or blended with dry materials, as necessary, to achieve proper moisture content for compaction. Non-residential area soils/tailing shall be placed in essentially horizontal layers, with a slight surface slope to promote positive drainage. No material shall be placed on frozen soil, unstable soil, or soil that has water ponded on it. All lifts of fill material shall be compacted to the full width of the lift. Material shall not be placed during freezing or extremely wet weather.

C. Elevations of the final regraded surface of consolidated non-residential area soils/tailing shall be within minus 0.5 foot and plus 1.0 foot from those shown on the Drawings. The side slopes of the regraded embankments shall be no steeper than designed.

D. Fire grained tailing or water quenched slag free of visible fragments greater than 2 inches shall be used in the first two lifts over the repository. No demolition debris shall be placed over the repository limits and no haul traffic shall be allowed to pass over the repository.

3.7 COVER SOIL PLACEMENT

A. Cover soil shall be placed over the consolidated non-residential area soils/tailing in a loose lift as necessary to achieve a compacted thickness of 12-inches and compacted to at least 90 percent of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D-698). Water shall be added to the backfill, as necessary, to achieve proper compaction. Compaction will not be required for the top 6-inches of the 18-inches cover soil layer other than that achieved by the normal travel of placement and grading equipment.

B. , On slopes steeper than 10:1, cover soil shall be placed beginning at the bottom of the slope and extending upward.

3.8 RIPRAP

A. Rock for riprap shall be dumped and graded or otherwise moved into position such that the in-place material is stable, without tendency to slide, and such that no large voids exist in the finished layer. The inclusion of earth, sand, or rock dust in excess of 5 percent by volume of the finished riprap layer will not be permitted. Care shall be taken during placement not to

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damage the earth slopes, or the geotextile on which the riprap is placed. If riprap is dumped directly onto the geotextile material, the dumping height shall not exceed 2 feet.

3.9 BACKFILL & FINAL GRADING

A. Contractor shall perform final grading of the removal areas and soil cover areas as directed by the Company's Representative. Surfaces shall be graded at a relatively uniform slope toward the natural or created drainageways so that no areas of ponded water or localized depressions exist.

B. Backfill for the CZL Mill Site tailing excavation shall be placed in one foot lifts and compacted by the passage of the earthwork equipment.

3.10 DEVELOPMENT, REGRADING, AND RECLAMATION OF THE BORROW AREA

A. Remove vegetation and stumps from the borrow area, as necessary.

B. Remove topsoil (upper 4 inches, approximately) from the borrow area and stockpile for future use in the northwest corner of the Borrow Area.

C. Begin excavation of materials from the borrow area after installation of temporary run-on control berm, silt fences or other controls as indicated on the Drawings and as required by the SWMP.

D. Regrade the excavated portions of the borrow area to achieve a smoothly graded, free- draining area with no depressions or irregular areas.

E. Once material removal from the borrow area has been completed, spread the topsoil that has been stockpiled over the regraded portions of the borrow area, and revegetate in accordance with Section 02900.

3.11 PLACEMENT OF GEOTEXTILE AND SILT FENCES

A. Non-woven geotextile material shall be placed only on prepared, relatively smooth subgrade surfaces. Sections of geotextile for drainage ditches, spillways and diversion/sediment control berms shall be overlapped by at least 18 inches with the overlap in the downstream direction and no overlaps parallel to the side slopes.

B. All geotextile shall be adequately anchored in trenches with compacted backfill as shown on the Drawings.

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C. Place geotextile for silt fences with the fabric on the upstream side of support posts with seams sewn at the supports and with adequately anchored bases in accordance with the manufacturer's recommendations.

END OF SECTION

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SECTION 02215 STRUCTURE DEMOLITION AND MANAGEMENT OF DEMOLITION DEBRIS

PARTI GENERAL

1.1 DESCRIPTION

A. This section describes the requirements for the structure demolition and management of demolition debris materials. Structure demolition and management of demolition debris includes demolition of certain smelter structures, reduction of debris size to 10 feet or less for all non-salvageable materials to be placed under the soil cover, hauling salvageable materials to the scrap area, and relocation of remaining debris to the area to be covered by the soil cover.

1.2 RELATED SECTIONS

A. Section 01505 - Mobilization, Preparatory Work and Demobilization

B. Section 02200 - Earthwork for Repository Construction

1.3 SUBMITTALS

A. Contractor shall submit a description of its proposed methods of demolition, excavation and hauling with its bid proposal.

B. Contractor shall submit with its bid proposal a description of its methods for dust control during demolition, excavation and management of demolition debris materials.

1.4 SAFETY

A. Contractor shall shore, brace, or slope excavations, as necessary, in accordance with OSHA regulations, including 29 CFR 1926.650-.652, to ensure worker safety, and to protect property from damage during construction.

B. Contractor shall comply with the applicable occupational safety and health requirements of OSHA and applicable portions of NESHAP.

C. Contractor shall exercise particular caution during demolition and management of debris materials, which may exhibit elevated concentrations of arsenic, lead and other metals and which could present a potential health hazard to Contractor's site personnel, if not properly protected.

D. Contractor shall be fully responsible at all times for the health and safety of all personnel on the Site (including subcontractors), and shall take all necessary precautions to protect such health and safety.

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E. Contractor shall provide first aid materials and equipment at the Site, as necessary, and shall coordinate with local medical facilities and identify local emergency phone numbers to supplement job site safety and first aid.

F. Contractor shall comply with the requirements of the Site Health and Safety Plan and its own site-specific Health and Safety Plan.

1.5 DUST CONTROL

A. Contractor shall take adequate precautions to avoid dust emission during demolition, excavation and handling of debris materials and shall implement engineering controls, such as water sprays or dust suppressants, or cease work to control dust emissions as required by the Fugitive Emissions/Dust Control Plan and as directed by Company's Representative.

1.6 SURFACE WATER AND SEDIMENT CONTROL

A. Contractor shall use water trucks to wet designated truck haul routes, as necessary, to avoid visible dust emissions. Water applications shall not create unsuitable working conditions or excessive runoff.

B. Contractor shall control the release of sediment from demolition areas and the stockpiles to prevent sediment loading to drainages, as specified herein and in Section 02130.

1.7 MEASUREMENT AND PAYMENT

A. Payment for structure demolition and management of demolition debris will be made on a lump sum basis. Payment shall provide full compensation for all costs associated with demolition of the structures identified for demolition on Drawing 534451C-102; all associated asbestos inspections/certification and notices to regulatory agencies; and all excavation, sorting, size reduction, and hauling of the demolition debris as required to consolidate the materials on-site.

B. No extra payment will be made for control of surface water, dust, erosion, or sediment during excavation, hauling and placement of materials.

C. No extra payment will be made for fall protection required for elevated work conditions. These costs shall be included in the unit price for building demolition.

1.8 QUALITY CONTROL

A. Contractor shall use an adequate number of skilled workers experienced in the type of work to be performed. Use OSHA Hazwopper-trained workers for handling the demolition debris materials.

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PART 2 EQUIPMENT AND MATERIALS

2.1 DEMOLITION AND REMOVAL EQUIPMENT

A. Use suitable equipment for demolition, separatipn, size reduction and handling of debris material.

B. Do not use explosives for any demolition work without prior approval by company.

2.2 WETTING EQUIPMENT AND MATERIALS

A. Use continuously-operating water misting or periodic water spraying equipment (such as water trucks and fire hoses) for dust control during demolition, size reduction, handling and hauling activities.

B. Alternatively, use a spray-on polymeric dust suppressant or an amended water material (mixture of water and chemical wetting agent) to coat the debris during size reduction handling and transport, as directed.

2.3 DEMOLITION MATERIALS

A. Demolition materials prepared for placement in the unlined portion of the soil cover areas shall be as specified in 02200.

B. Debris material generated from structure demolition shall be crushed and blended with other excavated soils for placement in the soil cover areas.

C. Metal fragments shall be separated and hauled to the salvageable scrap metal area.

PARTS EXECUTION

3.1 PREPARATION

A. Prior to initiating construction activities, the Contractor shall independently identify and mark the location of all buried and overhead utilities present within the work areas using a qualified utility locator service. Contractor shall be responsible for protection of all active utilities in the vicinity of the work areas.

B. All survey monuments and property corner pins within the construction area shall be identified and marked by the Contractor. The locations of the monuments and pins shall be documented on the Drawings and their condition shall be recorded by the Contractor using photographs.

C. A notification of demolition activity shall be filed with the Colorado Department of Public Health and Environment a minimum often days prior to proceeding with demolition.

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3.2 DUST SUPPRESSION

A. Dust suppression water mist sprays shall be used to minimize the potential for fugitive dust emissions. Application rates shall be regulated to control dust during construction without contributing to the development of mud or contaminated runoff. The objective of dust suppression is to minimize airborne dust and, at the same time, minimize production of mud which could be transported out of the work area on haul trucks and other mobile equipment. Dust suppression equipment shall consist of standard fire hoses and spray regulators or approved equivalents. Contractor shall identify its own water source and make all necessary arrangements for access to the water.

3.3 DEMOLITION OF STRUCTURES

A. The structures to be demolished shall include the retaining wall between the rail tracks, rail car loading ramp, western ore bin, thaw house and adjacent structures, all miscellaneous structures in-between the thaw house and bag house manifold, ore house, bag house manifold and related structures, eastern loading platform, and brick wall east of the ore house as identified on Drawing 534451C-102. The structures shall be demolished in a controlled manner down to the existing ground surface or concrete slabs, if present.

B. Large hoppers or other overhead equipment shall be cut free and lowered to ground prior to demolishing the structure. Steel support beams embedded in the concrete floor slab will be cut flush with the floor slab and removed. Removal of the underlying building slabs is not a requirement of this work.

C. The two above ground tanks adjacent to the ore house shall be emptied and relocated. The contents of these tanks shall be collected and recycled by a third-party petroleum recycler approved by the Company. Prior to moving, the internal tank atmosphere shall be rendered inert using dry ice, nitrogen, or other means acceptable to the Company. Contractor shall periodically monitor the internal atmosphere of the tank throughout the relocation process and conduct additional inerting if the tank atmosphere exceeds 10 percent of the lower explosive limit (LEL). The tanks shall be relocated to an area adjacent to the salvageable scrap metal area, to be identified by the Company.

D. Salvageable steel shall be separated from the demolition debris and hauled to the designated scrap metal area. Recycling of the scrap metal is not part of this work.

E. - All wood and roofing material shall be resized to meet the maximum size requirements identified below, as necessary, and included in the non-residential area soils/tailing cover area.

F. No materials shall be shipped off-site for recycling or disposal without the prior approval of the Company.

G. Concrete shall be crushed as necessary to achieve the maximum size requirements identified below and placed in the soil cover area.

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3.4 EXCAVATING AND LOADING SALVAGABLE MATERIALS

A. Excavate and haul miscellaneous salvageable scrap metal at the Site to the temporary salvage area. Scrap iron such as rail, pipe, or other materials not containing non-residential soils, flue dust or tailing materials shall be stockpiled in the area identified for storage of salvage materials.

3.4 MATERIAL SIZE REDUCTION

A. All non-salvageable concrete, wood, or other structural debris resulting from demolition activities shall be reduced to a maximum particle size of 10 feet in any dimension. The means by which these materials are reduced are the responsibility of the contractor.

3.5 DEMOLITION DEBRIS PLACEMENT

A. Once the non-salvageable demolition debris has been reduced to the maximum particle size of 10 feet or less, the demolition debris material shall be blended with the non-residential soil. The methods and degree by which these materials shall be blended is that which can be achieved by heavy earth moving equipment such as tracked dozers, excavators and rubber tired graders. Debris is to be blended to minimize bridging and the presence of voids.

B. As the demolition debris is blended with the non-residential area soil/tailing, placement and compaction of these materials shall follow the requirements outlined in Section 02200 Sub- Section 3.4 - Compacted Non-Residential Area Soil/Tailing Materials.

C. Placement shall be within the limits of the non-residential area soil placement identified on Drawing 534451C-105 and C-106.

3.7 DECONTAMINATION

A. Decontaminate onsite equipment and haul trucks as necessary prior to leaving the site. Decontamination shall consist of dry methods such as brooming, and use of shovel, trowels or small pry tools to remove any accumulations of source materials (such as non-residential soil, flue dust, or tailing) from the equipment.

END OF SECTION

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SECTION 02610 PIPE AND FITTINGS

PARTI GENERAL

1.1 DESCRIPTION

A. This section covers the requirements for the pipe and fittings required for the culvert pipe at the discharge of the AV Smelter runon/runoff control ditches.

1.2 RELATED SECTIONS

A. Section 02200 - Earthwork

1.3 PRODUCT DELVIERY, STORAGE, AND HANDLING

A. Exercise care in transporting and handling materials to avoid damage to pipe and fittings.

1.4 SUBMITTALS

A. Submit manufacturer's information for all pipe and appurtenant materials and shop drawings detailing pipe installations at least 14 days prior to delivery of pipe and appurtenant materials.

1.5 MEASUREMENT AND PAYMENT

A. Payment for installation of the profile-wall culvert pipe and will be at the lump sum price bid in the Schedule, and will include all earthwork and bedding materials associated with installation.

PART 2 PRODUCTS AND EQUIPMENT

2.1 PIPES

A. Profile wall culvert pipe shall be an HDPE pipe in accordance with ASTM F-894, with a smooth interior and an externally ribbed profile-wall. It shall be a Class 63 as manufactured by Spirolite. The polyethylene used in the pipe shall be in accordance with ASTM D-1248, Type ffl, Class C, Category 5, Grade P34, or better.

2.2 FITTINGS AND JOINTS

A. Fittings for the profile-wall HDPE pipe shall be bell and spigot joints with gaskets in accordance with ASTM D-3212.

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2.3 BEDDING MATERIAL

A. Bedding material shall be 1.5-inch minus crushed rock or slag containing less than 12 percent fines.

PARTS EXECUTION

3.1 GENERAL

A. All pipes shall be installed to the lines and grades shown on the Drawings. Care shall be taken to avoid clogging or damaging the pipes during the progress of the Work. Should any pipe become clogged, obstructed or damaged for any cause before final acceptance of the piping or associated Work, the pipe shall be cleaned out suitably, repaired, or replaced, as necessary. No pipe shall be used that has been significantly damaged.

B. Verify that trench condition, bedding material or excavated base is ready to receive pipe placement.

C. Large stones or other hard matter which could damage HOPE pipe shall be removed prior to pipe placement.

3.2 PLACEMENT OF PIPES

A. Place all pipes for culvert outfall to the lines and grades shown on the Drawings.

B. HDPE profile-wall pipe and finings shall be handled and placed to design lines and grades in accordance with the pipe manufacturers recommendations.

C. All HDPE pipe shall have suitable bedding material placed beneath, around and above the pipe as shown on the Drawings. Place all bedding and pipe backfill as specified in Section 02200.

3.3 TOLERANCES

A. Culvert pipe shall be placed to within minus 0.2 percent and plus 0.5 percent of the slope of the invert shown on the Drawings and within plus or minus 2 feet of the alignment shown on the Drawings.

END OF SECTION

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SECTION 02770 GEOSYNTHETIC LINER SYSTEMS

PARTI GENERAL

1.1 WORK INCLUDED

A. This section covers the supply and installation of geosynthetic materials, including geotextile cushion and geomembrane materials as well as all anchor trenches for the cover system.

1.2 RELATED SECTIONS

A. Section 02130 - Surface Water Control During Construction

B. Section 02200 - Earthwork

1.3 SUBMITTALS

A. Submit information regarding the geotextile and geomembrane manufacturer, fabricator and installer at the time of bid.

B. Submit geotextile and geomembrane panel diagrams and manufacturer's conformance certificates at least 20 days prior to installation.

1.4 QUALITY CONTROL -

A. Contractor shall perform geosynthetic installation with trained personnel experienced in similar installations.

B. All field seams shall be tested for adequacy using an acceptable method as specified in Part 3.4 of this Section.

C. Geotextile and geomembrane manufacturers shall submit appropriate manufacturing quality control data as well as the minimum average roll certifications.

1.5 MEASUREMENT AND PAYMENT

A. Measurement for payment of the geotextile and geomembrane installations for the repository liner/cover system shall be made by the square feet and verified by field survey of the net area of material completely installed. The measurement will not include the materials buried in anchor trenches or incorporated as overlap in seams. Payment will be based on the bid unit price and will include all overlapping, seaming, anchor trenches, and quality control testing.

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1.6 MATERIAL HANDLING AND STORAGE

A. Geosynthetic materials, including geotextile and geomembrane liner material, shall be handled in accordance with manufacturer's recommendations so as not to damage the materials prior to installation. Materials shall be properly marked indicating proper direction of unrolling during field deployment. A visual inspection of each roll should be made during unloading to identify if any packaging has been damaged. Rolls with damaged packaging should be marked and set aside for further inspection. The packaging should be repaired prior to being placed in storage. Unloading, on-site handling and storage of the geotextile and geomembrane are the responsibility of the Contractor.

B. Materials shall be shipped and stored in rolls as received in the original photo-degradation, ultraviolet (UV) light resistant packaging. All stored geosynthetic materials at the Site shall be placed on timbers or other means to provide sufficient support off the ground surface. A dedicated storage area shall be selected at the site that is away from high traffic areas and is level and well drained.

C. Rolls shall be stored in a manner that prevents sliding or rolling from the stacks and may be accomplished by the use of chock blocks. Rolls should be stacked at a height no higher than that at which the lifting apparatus can be safely handled (typically no higher than four rolls).

D. All stored geosynthetic materials (geotextile, geomembrane) must be covered with a plastic sheet or tarpaulin until they are deployed.

E. The integrity and legibility of the product labels shall be preserved during storage. Each roll shall be labeled identifying: lot number, roll number, roll length, roll width and roll weight.

PART 2 MATERIALS

2.1 GEOMEMBRANE LINER MATERIALS

A. Geomembrane materials shall be all new material with no visible defects.

B. Geomembrane liner for the lined repository system shall be a 60-mil high density polyethylene (HDPE) having a minimum puncture strength of 108 pounds (ASTM D 4833), a minimum yield stress of 125 pounds per inch (ASTM D 638) and a minimum roll width of 22.5 feet. Liner seaming materials shall be as recommended by the liner manufacturer.

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2.2 FABRICATION AND INSTALLATION OF GEOMEMBRANE LINERS FOR REPOSITORY SYSTEM

. A. Fabricate panels for geomembrane liners for the repository system in sections as large as possible, minimize the number of field seams required. The liner manufacturer shall specify fabrication and testing of fabricated panels. No defective seams or exposed scrim or fabric will be allowed.

B. Acceptable liner fabricators include: GSE Lining Technology, Inc., (www.gseworld.com. 800-435-2008); Agru America, Inc., (800-321-1379); and Poly-Flex, Inc. (888-765-9359)

C. Acceptable liner installers include: Colorado Lining International, Parker, CO; and Lange Containment Systems, Inc., Denver, CO.

2.3 GEOTEXTILE CUSHION LAYER MATERIAL ADJACENT TO GEOMEMBRANE

A. Geotextile for use as cushion or protective material over the repository system geomembrane bottom, side slopes and top cover, shall be a non-woven polypropylene or polyester material having a weight of at least 12 ounces per square yard, a puncture strength of at least 170 pounds (ASTM D-4833) and a grab tensile strength of at least 300 pounds when tested in accordance with ASTM D-4632.

PART 3 EXECUTION

3.1 FOUNDATION PREPARATION

A. The subgrade upon which the geosynthetics are to be placed shall be compacted, as specified in Section 02200, so that a smooth surface is achieved with no rutting, debris, organic material, ponded water or frozen material.

B. Place geomembrane and geotextile, where required, on prepared subgrade as shown on the Drawings. ,

C. The installation contractor shall certify in writing that the surface on which each geomembrane section is to be installed is acceptable. No installation of the liner shall commence until this certification is furnished to and accepted by the Company's Representative for each section of the prepared repository foundation surface.

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3.2 GEOMEMBRANE INSTALLATION

A. The geomembrane shall be placed in a manner to avoid damage to the materials, to minimize handling and in accordance with the approved shop drawings and the manufacturer's recommendations. Only those geomembrane panels, which can be unpackaged, placed into position, anchored, seamed the same day shall be deployed.

B. Individual panels of liner material shall be laid out and overlapped by a minimum of 4 inches prior to placing subsequent panels. Extreme care shall be taken by the installer in the preparation of the areas to be overlapped. Such areas shall be cleaned and prepared according to installation procedures provided by the material manufacturer and be subject to approval by the Company's Representative.

C. At the top of the embankment slopes, the geosynthetics shall be properly anchored as illustrated in the Drawings. Anchor trench compacting equipment shall not come in contact with the geomembrane or geotextile.

D. Pulling liner panels along unprepared ground prior to installation will not be permitted. Individual panels must be lifted and properly placed prior to installation.

E. Geomembrane liner installation shall be performed so as to avoid damage during high winds. Secure the leading edge of the geomembrane at all times with sandbags, rubber tires or other means that are adequate to hold it down during high winds. Vehicles, LGP track equipment and heavy equipment are not allowed on the geomembrane at any time during or after installation.

F. Horizontal seams will not be permitted on the slopes or within 3 feet of the slope toes.

G. No wrinkles, fish mouths or other defects shall be allowed within the overlap area. Where defects occur, the material shall be cut to eliminate the seam irregularity, and repaired with an overlap patch.

H. Construct anchor trenches as shown on the Drawings and in accordance with approved Shop Drawings.

I. Any geomembrane replacement that is required due to damage from the Contractor's operations or failure to adequately protect the liner during installation will be made at no additional cost to the Company.

J. All material used to make extrusion welds shall be of a type recommended and supplied by the manufacturer and shall be delivered in the original sealed container, each with an indelible label bearing the brand name, manufacturer's mark number, and complete directions as to proper storage.

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K. The thermal welding (hot air, hot wedge or other, as applicable) seaming equipment used shall be capable of continuously monitoring and controlling the temperature of the zone of contact where the machine is actually fusing the lining material so as to ensure that changes in ambient conditions will not affect the integrity of the weld.

I L. All welds or seams shall be tightly bonded upon completion of the work and shall provide a minimum width of 1.5 inches of continuous bond (wider as required for double wedge). Any membrane area showing injury due to excessive scuffing, puncture, or distress from any cause shall be repaired by replacement or covering with an additional piece of geomembrane.

M. Welding or seaming of liner material on which visible moisture, dirt or foreign debris are present will not be permitted.

N. Perform welding or seaming when ambient air temperatures are 40°F or above. If welding or seaming is performed at ambient temperatures of below 40°F, the contractor shall have appropriate temporary facilities available (enclosing, space heaters, etc.) to permit conditioning of the local ambient temperature in the vicinity of seaming operations such that they are greater than, or equal to, 40°F. All such temporary facilities shall be subject to the approval of the Company's Representative.

O. All exposed edges of geomembrane shall be sealed with extruded HDPE material.

P. During cold weather placement, allow sufficient slack length in the liner to accommodate contraction and shrinkage.

3.3 GEOTEXTILE INSTALLATION

A. After the repository subgrade has been approved, the geotextile protective material can be placed free of wrinkles or folds.

B. Each geotextile roll should be installed in the direction of the slope. The geotextile shall be installed along the roll length and thus should be installed in the intended direction of deployment.

C. Install non-woven geotextile (12 oz/sy) underneath and on top of the bottom geomembrane liner to sandwich the entire geomembrane surface. The geosynthetic cushion layer placed on top of the geomembrane liner must be completely installed prior to placement of the flue dust materials.

D. Install nonwoven geotextiles (12 oz/sy) over the repository side slope geomembranes allowing a 4 foot runout section at the top of the slopes but not anchored in the trenches. Overlap sections of side slope geotextile by 18 inches with vertical overlaps, without sewing or seaming to allow movement of the side-slope geotextiles. Extend geotextiles approximately one foot beyond the toe of the side slopes, overlapping the floor geotextile.

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E. Install 12 oz/sy non-woven geotextile over the top geomembrane prior to placement of the non-residential area soils. Sew sections of geotextile together, or overlap a minimum of 18 inches.

F. Placement of the non-residential area soil materials shall proceed immediately following the placement and inspection of the geotextile and shall be done in a manner that prevents damage to the geotextile or underlying geomembrane.

G. Placement of the soil cover shall proceed after all of the non-residential area soils and tailing materials have been consolidated and compacted. The soil cover shall be placed described in Section 02200.

3.4 FIELD SEAM TESTING/QUALITY CONTROL FOR GEOMEMBRANE

A. The installer shall employ on-site continuous non-destructive testing for all field welds or seams to ensure watertight homogeneous seams in accordance with ASTM D-4437. Acceptable methods are:

1. Air Lance Test.

2. Vacuum Chamber Test with 3 to 5 psi vacuum.

3. Ultrasonic (High Frequency) Pulse Echotesting.

4. Double Seam Pressurization Test (for HOPE material with double wedge seam).

5. Mechanical Point Stressing (qualitative measure of edge bonding only).

B. A quality control technician shall inspect and test each seam. Any area showing a defect shall be marked and repaired in accordance with approved procedures. The locations and types of defects shall be indicated on the QA/QC drawings.

C. For the repository system liner a test weld or seam 2 feet long shall be run each day of liner installation, prior to liner welding or seaming and under the same conditions as exist for the liner welding. The test weld or seam shall be marked with date, ambient temperature, and welding machine number. Sample coupons shall be cut from the test weld or seam and pulled in shear and peel. The tensile yield strength of all seams shall be a minimum of 85 percent of the tensile yield strength of the parent material when tested in accordance with ASTM D- 4437. Failure of the seam in peel shall exhibit Film Tear Bond (FTB). Random samples shall be removed from the seams of the installed liner at a frequency of at least one per 1,000 feet of weld or seam, at locations designated by the Company's Representative. These samples shall also be tested in shear and peel. Shear strength of seams for 60-mil HOPE shall be equal to or greater than 85 percent of the parent material and the peel strength (ply adhesion) shall be equal to or greater than 15 lbs./in of width. Any seams failing such tests shall be repaired using approved methods, and retested, to the satisfaction of the Company's Representative.

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3.5 REPAIRS

A. Patches shall be cut with rounded comers and shall extend a minimum of 6 inches in each direction from the damaged area. The entire surface of the patch shall be bonded to the geomembrane fabric material to the extent practicable. If reinforced patches are used, the cut edges of the patch must be coated with an approved edge caulk or extrudate.

3.6 WARRANTY AND GUARANTEE

A. The manufacturer of the geomembrane shall guarantee the geomembrane liner, and installation for a period often years, on a pro-rata basis, during which time the geomembrane liner materials and workmanship specifically provided or performed under this project shall be free from any significant defects. Such guarantee shall provide for the total or complete repair or replacement of the defect or defective area of lining materials upon written notification and demonstration by the Company's Representative of the specific nonconformance. Repairs or replacement shall be made within a reasonable period of time at no cost to the Company.

END OF SECTION

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SECTION 02900 VEGETATION ESTABLISHMENT - SEEDING

PART.l GENERAL

1.1 WORK INCLUDED

A. This section describes the requirements of seeding, fertilizing, and erosion control on the AV- CZL sites and related construction areas, as necessary. Seeding shall be performed in all disturbed areas including the run-on/run-off control channels (excluding riprapped portions of the channels), excavation areas and soil cover areas. Additional seeding areas may be required as determined by the Company's Representative.

1.2 RELATED SECTIONS

A. Section 02200 - Earthwork

1.3 SUBMITTALS

A. Submit information on proposed seed and fertilizer at least 10 days prior to delivery.

B. Contractor shall provide verification of inoculation of legume species with the appropriate Rhizobium bacteria strain.

C. Submit manufacturer's data on erosion control mats, or fabrics at least 10 days prior to delivery.

1.4 MEASUREMENT AND PAYMENT

A. Measurement for seed and fertilizer application shall be made based on the actual areas by grade or slope, in acres, where the requirements of this section are completed. Payment shall be made at the unit prices per acre provided by the Contractor on the Bid Schedule.

B. Measurement for seed protection/erosion control shall be made based on the actual areas by grade or slope, in acres, where the requirements of this section are completed. Payment shall be made at the unit prices per acre provided by the Contractor on the Bid Schedule. This pay item shall include the application of mulch, tackifier, and erosion control fabric, where required.

1.5 QUALITY CONTROL

A. Contractor shall use an adequate number of skilled workers, or qualified subcontractor experienced in the type of work to be performed.

Vegetation Establishment - Seeding J:\BLD01\5344\5344-50\AV CZLDESIGN\FINAUAV_CZLSPECSREVl.DOC 02900-1 Revision No. 1 March 5, 2005

B. Contractor shall provide seed mixture in containers showing the percentage of each species in the seed mix, year of production, net weight, date of packaging, name and address of supplier, percent of weed seed content, and guaranteed percentage of purity and germination.

1.6 DELIVERY, STORAGE, AND HANDLING

A. Deliver fertilizer in waterproof bags showing weight, chemical analysis, and name of manufacturer.

B. Deliver grass seed mixture in sealed containers. Seed in damaged packaging is not acceptable.

PART 2 PRODUCTS

2.1 SEED SUPPLIERS

A. Seed suppliers must provide labeling of variety, purity, and germination. State seed quality laws must be satisfied by the supplier. Seed supplier must be approved by the Company's Representative.

2.2 SEED MIXTURE

A. Use the following seed mixture for all disturbed areas requiring vegetation establishment.

Seed Mixture o . „ XT Seeding Rate (Ib. Pure _Specie s Common Name TLiv. e cSee d., {PLS}/acrem0i/ \) Agropyron desertorum Std. Crested wheatgrass (Summit) 4.0 Agropyron riparium Streambank wheatgrass 5.0 Bromus inermis Smooth brome (Manchar) 6.0 Festuca longifolia Hard fescue (Serra) 1.5 Phleum pratense Timothy (Climax) 0.5 Schizachyrium scoparium Little bluestem 3.0 Secale cereale Cereal rye 10.0 Astragalus cicer Cicer milkvetch 3.0 Trifolium repens White dutch clover 0.5 Triticum aestivum x Elytrigia Regreen , . elongata Total: 40.0 Ib. PLS/acre

B. Changes from the seed mixture must be approved by the Company's Representative.

C. Seed for legume species (i.e., Astragalus cicer and Trifolium) shall be inoculated with the appropriate Rhizobium bacteria strain prior to seeding.

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2.3 ACCESSORIES

, A. Mulching Material for Seeded Areas: Dry oat or wheat straw, or native hay free from weeds and foreign matter detrimental to plant life. Manufactured wood cellulose fiber (chip form) may be used instead of straw for the top surface of the soil cover area (slopes 10:1 or less). If mulching with straw or hay, the material will be crimped into the surface soil.

B. Fertilizer for Seeded Areas: Inorganic chemical fertilizer as follows: -Nitrogen (as N) - 80 pounds/acre; -Phosphorous (as P2O5) - 80 pounds/acre; -Potassium (as K^O) - 0 pounds/acre;

C. Tackifier: Tackifier for use on this project shall be a mulch tackifier with polypropylene fibers blended with water to form a pumpable mixture, such as Rantec Corporation's R-Tack Plantago Tackifier, or approved equal.

D. Stakes: Softwood lumber, chisel pointed.

2.4 EROSION CONTROL FABRIC

A. Erosion control fabric shall consist of straw, straw/coconut, or coconut fibers stitched into or between 100 percent biodegradable nettings woven from lightweight, high strength jute yarn such as North American Green's S75BN straw matrix, or approved equal.

PARTS EXECUTION

3.1 INSPECTION

A. Verify that prepared soil base is ready to receive the work of this section.

B. The commencement of installation/application shall constitute acceptance of existing site conditions by Contractor.

3.2 FERTILIZING

A. - Apply fertilizer in accordance with manufacturer's instructions.

B. Apply fertilizer at the rate specified in 2.3B (above).

C. Apply after smooth raking of topsoil.

D. Mix thoroughly into upper 3 inches of topsoil for dry application.

E. In the case of dry application, do not mix fertilizer with seed.

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3.3 SEEDING

A. Drill seed application is acceptable for.slopes equal to or flatter than 3:1 (33%). Slopes steeper than 3:1 must be seeded by dry broadcasting or hydroseeding.

I B. Apply seed evenly at a broadcast (or hydroseed) application rate of 40 Ibs PLS per acre. Adjustment to bulk rate shall be made for variations in seed purity and germination to achieve the PLS equivalent rate. Hydroseeding is acceptable as a broadcast method of seeding and fertilizing. If dry broadcasting is done, rake seeds into the upper soil surface slightly. If drill seeding is done, apply seed at half of the specified broadcast rate. Do not seed area in excess of that which can be mulched on the same day.

C. Seeding season: After October 1 until consistent ground freeze (that time at which the surface soil, due to freeze conditions, prevents burying the seed 0.5 inch through normal drill seeding operations) or from spring thaw until June 15.

D. Do not sow immediately following rain or snowfall, when ground is too dry, or during windy periods.

E. Identify seeded areas with stakes around area periphery. Space stakes at 30 to 100-foot intervals.

3.4 SEED PROTECTION/EROSION CONTROL

A. Immediately following seeding, apply mulch at a rate of at least 2.0 tons per acre or as recommended by the manufacturer. If mulching with straw or hay, the material shall be crimped into the soil to ensure that the mulch will not redistribute after application. Tackifier shall be used in addition to crimping on all slopes 10:1 or steeper.

B. For slopes equal to or steeper than 3:1, apply mulch and tackifier, with mulch applied at a rate of 4.0 tons per acre. Hay or straw mulch shall be crimped into the surface prior to application of the tackifier.

C. For all slopes 5:1 or steeper, place two (2) strips of erosion control fabric across the slope at ten to twenty feet below the crest of the slope; and two (2) strips of erosion control fabric across the slope at the mid-point (i.e., halfway down the slope). Place erosion control fabric prior to the application of the straw or hay mulch. Follow erosion control fabric manufacturer's instructions, which should include, at a minimum:

1. Lay fabric smoothly on surface providing 12-inch overlap of adjacent rolls. Overlap upper roll sections onto lower roll sections.

2. Secure outside edges of overlap at 36-inch intervals with stakes.

3. Place 2 anchors per square yard on erosion control fabric placed on slopes of 2.5:1 to 2:1.

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END OF SECTION

Vegetation Establishment - Seeding J:\BLDOI\5344\5344-50\AV CZL DESIGNNFINALAAV CZLSPECSREV1.DOC 02900-5 APPENDIX E

CONSTRUCTION QUALITY ASSURANCE PLAN CONSTRUCTION QUALITY ASSURANCE PLAN

ARKANSAS VALLEY SMELTER AND COLORADO ZINC-LEAD MILL SITE OPERABLE UNIT 5 CALIFORNIA GULCH SUPERFUND SITE

July 2004

Prepared for:

ASARCO Incorporated 495 East 51st Avenue Denver, CO 80216-2098

Prepared by:

MFC, INC. 4900 Pearl East Circle, Suite 300W Boulder, CO 80301 (303)447-1823 FAX: (303)447-1836

MFG Project No. 5344.51 TABLE OF CONTENTS

LIST OF TABLES : : 3 LIST OF FIGURES 3 LIST OF ATTACHMENTS... 3 1.0 INTRODUCTION , 4 2.0 PROJECT ORGANIZATION AND SUPPORTING INFORMATION 5 3.0 REPSOSITORY/SOIL COVER CONSTRUCTION 7 3.1 Quality Control ...7 3.1.1 Flue Dust Repository Construction 8 3.1.2 Non-Residential Soils/Tailing 9 3.1.3 Soil Covers 9 3.2 Quality Assurance 9 3.2.1 Flue Dust Repository Construction 10 3.2.2 Soil Covers 10 3.2.3 Stormwater Management 10 4.0 ENVIRONMENTAL SAMPLING AND ANALYSIS 12 4.1 Project Responsibilities 12 4.2 Sampling Objectives 13 4.2.1 Flue Dust Removal Confirmation 13 4.2.2 Non-Residential Area Soils/Tailing Removal Confirmation ,14 4.2.3 Sampling of Ambient Dust '.15 4.3 Quality Assurance Objectives 15 4.3.1 Flue Dust Removal Confirmation , 16 4.3.2 Non-Residential Area Soils/Tailing Removal Confirmation 16 4.3.3 Sampling of Ambient Dust 17 4.4 Sampling Procedures 17 4.4.1 Flue Dust Removal Confirmation 17 4.4.2 Non-Residential Area Soils/Tailing Removal Confirmation 18 4.4.3 Sampling of Ambient Dust 18 4.5 Sample Custody 18 4.6 Analytical Procedures and Calibration 20 4.6.1 Analytical Parameters and Methods 20 4.6.2 Field Calibration Procedures 20 4.6.3 Preventative Maintenance 21 4.7 Data Reduction, Validation and Reporting 21 4.7.1 Field Measurement Data 21 4.7.2 Laboratory Measurement Data 21 4.7.3 Data Review and Evaluation 22 4.7.4 Data Validation 22

ASARCO Incorporated MFC, Inc. J:\BLDOI\S344\5344-50\AV_CZLDaigii\QAPtin\QAPIin.doc 1 ' Jllty 2004 4.7.5 Data Management and Reporting 23 4.8 Internal Quality Control Checks .23 4.8.1 Field Quality Control Checks.. 24 4.8.2 Laboratory Quality Control Checks 25 4.9 Technical System Audits 26 4.9.1 Systems Audits 26

4.9.2 Frequency and Scheduling r 27 4.9.3 Audit Reports 27 4.10 Calculation of Data Quality Indicators 28 4.10.1 Precision ; 28 4.10.2 Accuracy 29 4.10.3 Compieteness 29 4.10.4 Representativeness : 30 4.11 Corrective Action 30 4.12 Quality Assurance Reports 31 5.0 CONSTRUCTION DOCUMENTATION.. 32 5.1 Project Startup Phase : 32 5.2 Construction Phase 32 5.3 Construction Closeout Phase 32 6.0 REFERENCES : 34

t

ASARCO Incorporated MFG. Inc. J:\BLDOIVJ344\5344-50\AV_CZL DnignXQA Plln\QA Plan.doc 2 Jllfy 2004 LIST OF TABLES

Table 4-1. Quantitative Measurement Objectives for Analyses of Removal Confirmation Soil Samples Table 4-2. Analytical Methods, Holding Times, and Quantitation Limits

LIST OF FIGURES

Figure 4-1. Flue Dust Removal Areas and Associated Removal Confirmation Decision Units - Blast Furnace/Baghouse Area Figure 4-2. Flue Dust Removal Areas and Associated Removal Confirmation Decision Units - Roasting Plant Area

LIST OF ATTACHMENTS

Attachment A Standard Operating Procedures

ASARCO Incorporated MFC, Inc. J:\BLDOI\3344\5344-50UV_CZLDnignVQAPlM\QAPiin-doe 3 . July 2004 1.0 INTRODUCTION

This Construction Quality Assurance Plan (CQAP) presents requirements for quality assurance (QA) inspection and testing of remedial action construction at the Arkansas Valley (AV) Smelter/Colorado Zinc-Lead (CZL) Mill site. These two areas (the AV/CZL site) comprise a portion of Operable Unit 5 (OU5) at the California Gulch Superfund Site located in Leadville, Colorado.

ASARCO Incorporated (Asarco) is responsible for remediation of the AV/CZL site. MFG, Inc. will represent Asarco during construction activities as the Supervising Contractor. This CQAP specifies procedures to provide for compliance with the remedial design to be performed by MFC's Field Project Supervisor and Environmental Quality Assurance Official. It also provides a brief summary of Quality Control (QC) procedures to be utilized by the construction contractor to achieve compliance with the plans and specifications. This CQAP is included as an appendix to the Remedial Design Report (RDR).

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\S344-JO\AV_CZLDciign\QAPIin\QAPIin.doc 4 July 2004 2.0 PROJECT ORGANIZATION AND SUPPORTING INFORMATION

This section provides an overview of the relationships between the project participants and their respective roles and responsibilities during implementation of the remedial action construction at the site. A list of the key participants follows:

Asarco: - The Company, as defined in the Construction Contract Documents;

Overall responsibility for remedial actions at the AV/CZL site.'

EPA: . - Onsite regulatory oversight personnel will communicate either directly with Asarco's project coordinator or with the Supervising Contractor, but not with the Remedial Action Constructors).

MFG: - Supervising Contractor, representing Asarco;

Overall responsibility for management and documentation of remedial actions, to provide for compliance with project requirements and achievement of project objectives.

Remedial Action Constructors): - Independent, contractors) retained by Asarco to carry out the remedial actions in accordance with approved designs and work plans. The contractors) will be selected through a competitive bidding process.

Asarco's Project Coordinator (PC) is Mr. Robert Litle. The U.S. Environmental Protection Agency's Remedial Project Manager (RPM) is Mr. Stan Christensen. The Project Manger (PM) for MFG is Mr. Daryl Longwell, and the Engineer of Record (EOR) for the design is Mr. Daryl Longwell, P.E. The PM for MFG will report directly to the PC for Asarco. The full-time onsite Field Project Supervisor (FPS) for MFG will be determined prior to initiation of construction. The FPS will have authority as Asarco's representative onsite, and will report directly to the PM/EOR. The FPS will be responsible for day-to-day inspection and management of remediation activities to provide for compliance with the project plans and specifications and will document all inspections and work progress for compliance and for construction contract .administration purposes. The FPS will also coordinate all field surveying and testing performed by third parties to provide for compliance with the project plans and specifications. All contractor technical submittals and project design changes will be routed through the EOR for review and approval, and all design or scope changes will be subject to review and approval by the PM and by the PC. All major project change orders will be subject to review by the PC based on recommendations from the EOR or PM. The Environmental Quality Assurance Official (EQAO) will be Mr. Dave Colvin. The EQAO will be responsible for ensuring that the testing procedures are performed in accordance with this CQAP

ASARCO Incorporated MFG, Inc. J:\BLD01\i344\5344-50UV_CZLDcji8n\QAPIin\QAPUivdoc 5 . Jllfy 2004 and will consult with the FPS to confirm that the field procedures are performed in accordance with the design. The EQAO's duties will include reviewing documentation of field sampling procedures, verifying that the laboratory is adhering to project specifications, and working with the laboratory to identify the need for corrective measures and their completion.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\3J44-50UV_CZLDeii8n\QAPIin\QAPUn.doc 6 Jlify 2004 3.0 REPSOSITORY/SOIL COVER CONSTRUCTION

This section describes the procedures and testing frequencies to be used in achieving project QA/QC as specified in the Technical Specifications (Appendix D of the RDR) for construction of the flue dust repository and soil covers. In this CQA Plan, quality control refers to the procedures, methods and tests utilized by the construction contractor to achieve compliance with the plans and specifications, and quality assurance refers to the site inspection, checks and tests performed by MFG (the Supervising Contractor) to ensure that the substantive requirements and intent of the plans and specifications are met. Quality Control requirements are described here, because QA activities include inspection of the QC tests and performance of QA tests at a lesser frequency.

3.1 Quality Control

The primary quality control procedures to be utilized by the construction contractor include the use of adequately skilled personnel for the work being performed and compliance with any permits and the Construction Contract Documents. In addition, the contractor will be required to perform periodic level and/or survey controls and material testing to achieve compliance with the plans and specifications. Such survey controls and field checks will include checking the layout grade and dimensions of excavated areas and constructed soil cover barriers. These field controls will be performed each day that regrading work is performed at the site. Quality control testing will be required for the materials placed in the repository and for those used for construction of the soil cover barrier and regrading.

Quality control procedures and manufacturer's certifications will also be required for various installed equipment and materials such as geomembranes, geotextiles, erosion control material, fencing, temporary surface coatings, and vegetation. Quality control procedures will include proper storage and handling of equipment and materials, following the manufacturer's recommendations for installation (in addition to the specification requirements), using levels or survey equipment as necessary during installation, and providing material data and certifications regarding compliance with the specifications. Provided below are the minimum requirements for QC testing as defined in the Technical Specifications.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\3J44-5tlUV_C2LDtsiun\QAPIin\QAPIin.4oc 7 Jltty 2004 t 3.1.1 Flue Dust Repository Construction Field density QC testing of compacted fill placed in the repository will be required for every 500 cubic yards of flue dust placed and compacted, with at least one test for every lift of material placed. These tests may be performed using nuclear instruments in accordance with ASTM D-2922, or using sand-cone equipment in accordance with ASTM D-1556 (density) along with sample drying in an oven (ASTM D- 2216, if moisture determination is necessary). Therefore, either the sand-cone method or the nuclear instrument procedure may be used for determining the in-place density of materials placed in the repository. Each material type (e.g. flue dust, or other, if identified) will require a new Standard Proctor Test curve performed in accordance with ASTM D-698. Gradation of the materials placed in the repository will be verified by gradation analysis for every 1,000 cubic yards of material placed and a minimum of three gradation tests per material type. Gradation sieve analyses will be performed in accordance with ASTM D 422. No hydrometer tests are required.

Installation of the geomembrane for the lined repository will require trained personnel experienced in similar installations. Shop drawing submittals will be required from the manufacturer/installer showing liner panel layouts, seaming/connection details, and conformance certificates, which must be approved by the EOR or PM prior to installation. The liner manufacturer/installer will also be required to sign a certification that the subgrade conditions are acceptable for installation of the liner.

Prior to the installation of the geomembrane liner, the density of the floor of the repository foundation will be tested at a frequency of one test per 2,000 square feet. These tests may be performed using nuclear instruments in accordance with ASTM D-2922, or using sand-cone equipment in accordance with ASTM D-1556 (density) along with sample drying in an oven (ASTM D-2216, if moisture determination is necessary). The repository side slopes will be proof rolled and visually inspected to identify any areas that exhibit unsatisfactory deflection. Unsatisfactory deflection is defined as any area deflecting more than two inches under the compactive effort of a smooth drum vibratory roller type compactor with a minimum operating weight of 20 tons.

Both non-destructive (vacuum chamber or double seam pressurization for HDPE) and destructive (samples cut for shear and peel testing) liner seam tests will be required as described in the Technical Specifications, Section 02770. For the repository system geomembrane liner, a test weld or seam 2 feet long will be run each day, prior to liner welding or seaming and under the same conditions as exist for the liner welding. The test weld or seam shall be marked with date, ambient temperature, and welding

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\S344-50VAV.CZL Design\QAPlM\QAPIu.doc 8 Jllty 2004 machine number. Sample coupons shall be cut from the test weld or seam and pulled in shear and peel. The tensile yield strength of all seams shall be a minimum of 85 percent of the tensile yield strength of the parent material when tested in accordance with ASTM D-4437. Failure of the seam in peel shall exhibit Film Tear Bond. Random samples shall be removed from the seams of the installed liner at a frequency of at least one per 1,000 feet of weld or seam, at locations designated by the FPS. These samples shall also be tested in shear and peel. Any seams failing such tests shall be repaired using approved methods, and retested, to the satisfaction of the FPS. Geotextiles associated with the remedial construction will require QC submittals for material conformance with the specifications.

3.1.2 Non-Residential Soils/Tailing

Field density QC testing of compacted non-residentail soil and tailing will be required for every 3,000 cubic yards. These tests may be performed according to ASTM D-2922 or ASTM D-2216. Visual changes in the non-residential soil or tailing shall warrant a new Standard Proctor Test curve by ASTM D-698

3.1.3 Soil Covers

Material used for the soil covers will be obtained from an offsite borrow area (see Section 3.8 of the RDR.) Attainment of the minimum requirement for soil cover thickness will be verified by use of grade stakes. Control points will be established at a minimum frequency of 1 point per 10,000 square feet. Prior to cover placement, the control point will be marked with a wooden stake. The required 18-inch soil thickness level will be measured and marked on each stake. Following barrier placement, the elevation of the gravel barrier immediately adjacent to the control point will be inspected to confirm that the minimum 18-inch thickness cover requirement has been achieved. If the cover thickness requirement has not been met at any location, additional cover material will be added in the area.

3.2 Quality Assurance

The primary QA procedures will include full-time inspection of the construction by the FPS with periodic inspections by the EOR, PM and PC. All procedures, materials, and equipment used in the construction will be observed and monitored by the FPS on a daily basis. All QC data supplied by the contractor will be reviewed for testing adequacy and compliance with the plans and specifications. QC data or installed

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\SM4-50\AV_CZLDtjigii\QAPUii\QAPlin.doc 9 Jufy 2004 elements that are not in compliance with the plans and specifications will be reworked or replaced by the contractor so that the element is in compliance. All QC data and information supplied by the contractor will be documented by the FPS to allow complete project tracking of all components of the construction. Site project meetings will be held as necessary with the construction contractor, the FPS and oversight personnel to discuss work progress, QA/QC issues and upcoming work to maintain the overall project quality.

3.2.1 Flue Dust Repository Construction

Periodic QA testing of compacted flue dust materials may be performed by the FPS at a frequency of one test for every 5 or 10 QC tests to verify the accuracy of the QC tests, as determined to be necessary. QA density testing of the repository foundation will include visual observation of the subgrade reaction for each pass made with a vibratory compactor over the repository footprint including the 3(h):l(v) side slopes. Periodic QA testing will also be performed for gradation of excavated flue dust materials to verify the adequacy of such materials. QA measurements and surveying will also be performed as necessary during construction to verify dimensions, lines and grades, and interim and final surveys will be performed as directed by the FPS for payment purposes.

3.2.2 Soil Covers

As discussed in Section 3.1, soil cover thickness will be verified by installation of grade stakes prior to installation of the cover in a given area performed as part of the contractor's QC testing. At a minimum this work will be performed under the oversight of the FPS. Additional grade stakes may be added at the discretion of the FPS based on site-specific conditions. In addition, if questions arise about the soil thickness in a given area, the FPS may require excavation through the cover for the purposes of measuring the cover thickness.

3.2.3 Stormwater Management

QA procedures will include periodic inspection of all temporary Stormwater and erosion control elements to ensure compliance with the Stormwater Management Plan (Appendix G to the RDR) including subsequent addenda and the general permit (as applicable). Non-structural Best Management Practices and other site controls described in the plan will be inspected with conditions documented at least every

ASARCO Incorporated MFC, Inc. J:\BLDOI\3J44\5J44-50\AV_CZL DesignWJAPIin\OAPUn.doc 10 Jufy 2004 14 days during construction and after every significant runoff event. Deficiencies or facilities requiring maintenance will be directed to the construction contractor who will be responsible for maintaining the facilities during construction.

ASARCO Incorporated MFG. Inc. J:\BL001\5344\5M4-5(A.*V_CZLDt.ign\QAPI*n\<3APUn.doc 11 Jufy 2004 4.0 ENVIRONMENTAL SAMPLING AND ANALYSIS

This section describes the environmental sampling and analysis procedures, including quality assurance requirements to support implementation of the remedial actions. Environmental sampling tasks to be performed in support of remedial construction actions will include:

• Sampling and analysis of soil at the base of flue dust excavation areas to confirm that flue dust has been removed; • Sampling and analysis of soil at the base of non-residential area soils or tailing excavation areas to confirm that these materials have been removed; and • Sampling and analysis of dust samples collected as part of the air monitoring program to assess air quality.

This plan does not address sampling and analysis of dust or other media to assess the protection of workers. Analysis of samples for worker health and safety purposes will be addressed in the contractor's Health and Safety Plan which will be included as an attachment to the construction Health and Safety Plan (Appendix H to the RDR).

4.1 Project Responsibilities

Key positions of the environmental quality assurance team include: the EQAO; the Project Chemist; and the Laboratory QAO. The individuals who will fill the environmental quality assurance team roles are listed below.

MFG. Inc.

Environmental QAO Dave Colvin Project Chemist Cathy Shugarts

Asarco TSC Laboratory

Laboratory QAO To be Determined.

ASARCO Incorporated MFC. Inc. J:\BLDOI\5344\5J44-50\AV_CZL DesignNQA PUnVQA Plin.doc 12 July 2004 The Project Chemist will be responsible for coordinating with the laboratory regarding analytical requirements and scheduling. Upon receipt of the analytical data, the Project Chemist will perform the necessary data evaluation or validation (refer to Section 4.7); the EQAO may assist the Project Chemist in this function, if necessary. The Project Chemist will also provide support to the FPS and the EQAO regarding issues concerning sample collection, handling and storage.

The EQAO will be responsible for ensuring that the analytical procedures are performed in accordance with this CQAP and will consult with the FPS to confirm that the field procedures are performed in accordance with the plan. The EQAO's duties will include reviewing documentation of field sampling procedures, verifying that the laboratory is adhering to project specifications and working with the laboratory if corrective measures are necessary and require resolution. The EQAO may assist the Project Chemist in performing data evaluation or validation, if necessary. The EQAO will discuss any systematic errors or other anomalous data with MFC's PM and FPS. If corrective actions are necessary, the EQAO will be responsible for confirming that they are initiated and completed.

The Laboratory QAO is responsible for all aspects of the sample analyses. The Laboratory QAO will be responsible for ensuring that sample holding times and custody requirements are met, overseeing the analyses, confirming that the laboratory QA requirements are met, and reviewing the data packages prior to distribution. The Laboratory QAO will coordinate with the Project Chemist regarding any issues related to the sample analyses.

4.2 Sampling Objectives

4.2.1 Flue Dust Removal Confirmation

Sampling will be conducted following excavation of flue dust to confirm that the flue dust has been removed, from the designated excavation areas (see Figures 4-1 and 4-2.) The purpose of the confirmation sampling is to measure arsenic concentrations in the half-foot-thick soil interval immediately below the excavated area to determine if further material removal is necessary. In addition, samples will be collected adjacent to one removal area in the roasting plant area where sampling to support remedial design did not adequately delineate the extent of flue dust (see Appendix A to the RDR).

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\53M-50\AV_CZLDeiign\QAPUn\QAPUn.doc 13 Jltfy 2004 The excavated areas will be divided into decision units for confirmation testing. Each decision unit will encompass a maximum area of approximately 10,000 ft2 (i.e. equivalent to an area of 100 feet by 100 feet). However, smaller sampling units may be used in some areas to accommodate the actual excavation geometry. The initial layouts of decision units are shown on Figures 4-1 and 4-2.

Composite soil samples will be collected from each decision unit and analyzed for arsenic and lead. Each decision unit will be divided into four quadrants of approximately equal size and a single 0 to 6 inch depth soil sample will be collected from each quadrant. The four grab samples will be composited to generate one sample per decision unit. The measured arsenic concentrations will be compared to a removal confirmation level of 10,000 mg/Kg. If the arsenic concentration is less than or equal to 10,000 mg/Kg, no further excavation will be required within the unit. If the arsenic concentration is greater than 10,000 mg/Kg, an additional one-foot of soil will be excavated from the decision unit. Following any additional excavation, a second 4-by-l composite sample will be collected from the decision unit and analyzed for arsenic and lead. The procedure will be repeated as necessary until the 10,000 mg/Kg arsenic confirmation level has been achieved for the decision unit.

The removal confirmation soil samples will be analyzed using laboratory-based inductively coupled plasma (ICP) atomic emission spectrometry (EPA SW-846 Method 6010). All samples will be analyzed by the designated analytical laboratory to be selected at the beginning of the project. Specific procedures regarding collection, preparation and analysis of the confirmation soil samples are provided in Section 4.4.

4.2.2 Non-Residential Area Soils/Tailing Removal Confirmation

Sampling will be conducted following excavation of non-residential area soils or tailing in areas outside of the final soil covers. The purpose of the confirmation sampling is to measure arsenic and lead concentrations in the 6-inch-thick soil interval immediately below the excavated area to determine if further material removal is necessary.

The removal areas will be divided into decision units for confirmation testing. Each decision unit will encompass an area no greater than 22,500 ft2 (i.e., equivalent to an area 150 feet by 150 feet). This will result in approximately 80 non-residential area soils/tailing removal decision units at the AV Smelter site and 8 decision units at the CZL Mill site. Decision units will be established by the FPS as work progresses.

ASARCO Incorporated MFC, Inc. J:\BLDOI\3344\5344-5IMV_CZLDnign\QAPlan\QAPlin.doc 14 July 2004 Each decision unit will be divided into four quadrants of approximately equal size and a single 0 to 6 inch depth interval soil sample will be collected from each quadrant. The four grab samples will be composited to generate one sample per decision unit. The samples will be analyzed for arsenic and lead. The measured concentrations will be compared to non-residential area soils/tailing removal confirmation levels of 650 mg/Kg arsenic and 6,500 mg/Kg lead. If both arsenic and lead concentrations are below the respective levels, non-residential area soils and/or tailing removal would be confirmed and no further excavation will be required within the decision unit. If either the concentration for arsenic or lead exceeds the respective removal confirmation levels in the decision unit, an additional one foot of soil will be excavated from the decision unit and the area will be resampled. This process will be repeated until both the lead and arsenic confirmation levels have been achieved in the decision unit.

The confirmation soil samples will be analyzed using ICP. All samples will be analyzed at the designated analytical laboratory to be selected at the beginning of the project. Specific procedures regarding collection, preparation and analysis of the confirmation soil samples are provided in Section 4.4.

4.23 Sampling of Ambient Dust

The effectiveness of dust control measures in meeting air quality standards will be evaluated using real- time monitoring equipment and laboratory analysis of dust samples. The real-time monitoring equipment will be used to determine the immediate effectiveness of fugitive dust control measures. Exceedances of the established action levels for Total Suspended Particulate (TSP) will trigger the implementation of additional dust control measures or temporary suspension of activities. At the same time, filter samples of the ambient dust will also be collected and analyzed for lead, cadmium, and arsenic. These data will be used to document compliance with the air quality standards; help identify the source and nature of the dust; and assess the potential for offsite, airborne transport of arsenic, cadmium, and lead.

Sampling objectives for dust monitoring are described in detail in the Fugitive Emissions Dust Control Plan (Appendix F to the RDR).

4.3 Quality Assurance Objectives

The project QA objectives are directly tied to the data needs and data uses described in Section 4.2. During construction activities, environmental samples will be collected for three uses: (1) confirmation

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\»44-S

4.3.1 Flue Dust Removal Confirmation

Soil samples will be collected following excavation of flue dust to design depths to confirm that the i removal is complete. A sampling plan has been designed to provide representative samples from the base of each flue dust excavation area, as described in Section 4.2.1. The sampling plan provides a sufficient number of samples from which to describe mean arsenic concentration in remaining soils within each decision unit (as a composite of four grab samples). The arsenic concentration measured in each decision unit will be compared to a flue dust removal confirmation level of 10,000 mg/Kg. The lead concentrations of confirmation samples will also be measured to provide additional information on the types of materials present. Lead concentration data will be used for qualitative evaluation of removal effectiveness but will not be compared to a removal confirmation level. The sampling plan has been designed to result in collection of samples that are representative of site conditions using consistent methods to provide comparable results.

Soil samples will be analyzed for arsenic and using ICP. Table 4-1 provides the precision, accuracy, quantitation limit, and completeness objectives for arsenic analyses of confirmation soil samples by ICP. The precision and accuracy of the ICP arsenic and lead data will be evaluated relative to the measurement objectives given in Table 4-1. The representativeness of laboratory analyses will be evaluated from analyses of blanks, including equipment blanks and method blanks.

4.3.2 Non-Residential Area Soils/Tailing Removal Confirmation

Soil samples will be collected following excavation of non-residential area soils/tailing to design depths in areas outside the final soil cover to confirm that the removal is complete. A sampling plan has been designed to provide representative samples from the base of each excavation area, as described in Section 4.2.2. The sampling plan provides a sufficient number of samples from which to describe average arsenic and lead concentrations in remaining soils within each area. The concentrations measured in each

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\H44-50\AV_CZLDBigii\QAPUn\QAPIin.doc 16 Jufy 2004 decision unit will be compared to removal confirmation levels of 650 mg/Kg arsenic and 6,500 mg/Kg lead. The sampling plan has been designed to result in collection of samples that are representative of site conditions using consistent methods to provide comparable results.

Soil samples will be analyzed for arsenic and lead using ICP. The precision, accuracy, quantitation limit, and completeness objectives for arsenic and lead analyses of confirmation soil samples are the same as for flue dust confirmation sampling discussed in Section 4.3.1 and described on Table 4-1.

4.33 Sampling of Ambient Dust

Ambient air monitoring will be performed during construction activities to produce two types of data for evaluating the effectiveness of dust control measures:

• Real time TSP concentration data; and • Arsenic, cadmium and lead concentration data from TSP samples.

These data will be used for direct comparison to action levels for TSP and lead concentrations and to (•• identify when additional dust control measures are necessary. The Fugitive Emissions Dust Control Plan (Appendix F to the RDR) provides details of monitoring activities, including quality assurance objectives.

4.4 Sampling Procedures

4.4.1 Flue Dust Removal Confirmation

As discussed in Section 4.2.1, the flue dust excavation areas will be divided into decision units of approximately 10,000 ft2. A grab sample will be taken from each quadrant and composited. Specific procedures and protocols which be used to collect the confirmation soil samples are described in the Standard Operating Procedure for Removal Confirmation Soil Sample Collection (Attachment A). Information includes procedures for delineation of decision units, sample collection, sample preparation, documentation and equipment decontamination.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-JO\AV_CZL DaignXQA PI»n\QA PUn.doc 17 Jufy 2004 4.4.2 Non-Residential Area Soils/Tailing Removal Confirmation

As discussed in Section 4.2.2, the non-residential area soils/tailing excavation areas will be divided into decision units of approximately 22,500 ft2. Specific procedures and protocols which be used to collect the confirmation soil samples are described in the Standard Operating Procedure for Removal Confirmation Soil Sample Collection (Attachment A). Information includes procedures for delineation of decision units, sample collection, sample preparation, documentation and equipment decontamination.

4.4.3 Sampling of Ambient Dust

Details of sampling procedures for ambient dust are provided in the Fugitive Emissions Dust Control Plan (Appendix F to the RDR). '

4.5 Sample Custody

After samples have been collected, they will be maintained under strict chain-of-custody procedures in accordance with the Compendium of Standard Operating Procedures for the California Gulch CERCLA Site (EPA, 1996), or equivalent. The procedures described below document the transfer of custody of the samples from the field to the designated analytical laboratory and the associated documentation requirements. The field sampling personnel will complete a Chain-of-Custody Record and Request for Analysis (CC/RA) form for each shipping container (i.e., cooler or other container) of samples to be sent to the laboratory for analysis in accordance with the Compendium of Standard Operating Procedures for the California Gulch CERCLA Site (EPA, 1996), or equivalent. The CC/RA for a shipping container will list only those samples in that shipping container. Information contained on the triplicate carbonless CC/RA form includes:

• Project identification; • Date and time of sampling; • Sample identification; • Sample matrix type; • Sample preservation methods (if any); • Number and types of sample containers; • Sample hazards (if any);

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-5lAAV_CZLDcji8n\QAPIln\OAPUui.doc 18 Jllfy 2004 • Analysis type requested; • Sample turn-around time; • Method of shipment; • Carrier/waybill number (if any); • Signature of sampling personnel; • Signature, name and company of person relinquishing and person receiving the samples when custody is being transferred; • Date and time of sample custody transfer; and • Condition of samples upon receipt by laboratory.

The sample collector will cross out any blank space on the CC/RA below the last sample number listed (on the part of the form where samples are listed). A sample label will be affixed to each sample container. The label will be protected with a layer of clear tape, and each container will be sealed using custody seals. Each container will be placed in an air-tight plastic bag and carefully packaged in a shipping container (typically an ice chest) with Styrofoam peanuts, vermiculite or other packing material, if necessary, to prevent breakage during shipment. Custody seals will be signed and dated by the sample custodian prior to shipment. If the custody seal is broken, the Laboratory QAO will immediately notify the Project Chemist.

The sampling personnel whose signature appears on the CC/RA is responsible for the custody of the sample from the time of sample collection until the custody of the sample is transferred to a designated laboratory, a courier, or to another employee for the purpose of transporting the sample to the designated laboratory. The sample is considered to be in custody when the sample is: (1) in the direct possession of the sample custodian; (2) in plain view of the sample custodian; or (3) is securely locked in a restricted access area by the sample custodian.

Custody is transferred when both parties to the transfer complete the portion of the CC/RA under "Relinquished by" and "Received by." Signatures, printed names, company names, date and time are required. Upon transfer of custody, the sampling personnel who relinquished the samples will retain the third sheet (pink copy) of the CC/RA. When the samples are shipped by a common carrier, a Bill of Lading supplied by the carrier will be used to document the sample custody, and its identification number will be entered on the CC/RA. Copies, receipts or carbons of Bills of Lading will be retained as part of the permanent documentation in the project file. It is not necessary for courier personnel to sign the CC/RA. When the samples are received by the laboratory, the CC/RA will be immediately signed along

ASARCO Incorporated MFC, Inc. J:\BLWl\5344W344-5tKAV_CZLDtiign\QAPUu\QAPUm.doc 19 Jlity 2004 with the date and time of receipt. The top sheet (white copy) of the CC/RA will be returned to MFC with the final analytical report. ,

4.6 Analytical Procedures and Calibration

4.6.1 Analytical Parameters and Methods

Removal confirmation soil samples will be collected for laboratory analysis of arsenic and lead. Dust samples will be analyzed for arsenic, lead and cadmium. Table 4-2 provides the analytical methods, preservation and storage requirements, holding times, and quantitation limits required for the laboratory analysis of these samples. The specified methods provide data of appropriate quality for comparison to the removal confirmation levels and for assessing the effectiveness of the dust control measures.

All samples will be analyzed by the designated analytical laboratory to be selected at the beginning of the project. The removal confirmation soil samples will be analyzed by the laboratory for arsenic and lead using an ICP method. Samples will be dried, sieved, and ground by the laboratory prior to analysis.

The filters used to collect TSP dust samples will be weighed by the laboratory prior to and after use in order to perform the gravimetric analysis. The filters will then be digested and analyzed for lead, cadmium and arsenic by EPA method 6020 (ICP-MS). Additional information concerning the analysis of the dust samples is included in Fugitive Emissions Dust Control Plan (Appendix F of the RDR).

4.6.2 Field Calibration Procedures

Field instruments will be calibrated prior to use and at prescribed intervals while in use. Procedures for calibration of instruments will be the standard operating procedures as outlined in the owner's manuals for the specific field instruments.

ASARCO Incorporated MFG. Inc. J:\BLDQI\5344\5J44-50\AV_CaD»ign\QAPlM\QAPUn.(!oe 20 Jufy 2004 4.6.3 Preventative Maintenance

Field equipment will be inspected, visually and functionally, prior to each day's use at a minimum. Preventive maintenance activities will be documented in the field log book, and will identify the equipment and specify the maintenance tasks completed.

4.7 Data Reduction, Validation and Reporting

4.7.1 Field Measurement Data

Field measurements will be obtained from the MiniRAM sampler during remedial construction activities. Details concerning the collection, management, and evaluation of the data obtained from the MiniRAM sampler are provided in the Fugitive Emissions Dust Control Plan (Appendix F of the RDR). Air monitoring records and data printouts will be maintained on-site or at MFC's Leadville office.

4.7.2 Laboratory Measurement Data

Laboratory calculations and data review by the laboratory will be performed in accordance with procedures prescribed by the specific analytical method. The laboratory will review the results of laboratory QC analyses, instrument calibration and maintenance records, calculations, and the record of sample custody (including holding times) within the laboratory. The laboratory data packages will include:

i • Copies of the Chain-of-Custody records; • Sample results and units; • Date analyzed; • Analytical method; • Quantitation limits; • Laboratory QC results (laboratory control samples, matrix spikes, etc.); and • Method blank result.

ASARCO Incorporated MFC, Inc. J:\BUXM\3J44\5344-50\AV_CZLDtiigri\QAPlM\QAPIan.doc 21 Juty 2004 The data package for the ICP data will be used for validation and will also include back-up information concerning instrument calibration, sample preparation, sample run logs, and analytical raw data. Analytical data packages will be sent directly from the laboratory, in a hard-copy format, to the Project Chemist. The data will be reviewed by the Project Chemist or EQAO, as described below, and will be reported as described in Section 4.7.5.

4.7.3 Data Review and Evaluation

Upon receipt of the analytical results and data packages from the laboratory, the data will be reviewed by the Project Chemist or the EQAO for accuracy, precision, and completeness. The analytical data will be reviewed for the following items:

n

• Analyses performed and sample identifications conform to the information on the Chain-of- Custody records; • Sample holding times; • Specified quantitation limits (Table 4-2); • Laboratory QC results (laboratory control samples, matrix spikes) meet measurement objectives (Table 4-1); • Target analyte concentrations in method and equipment blanks; and • Reproducibility of field duplicate results.

Data that satisfy the quality assurance objectives for this project will be considered usable for comparison to the appropriate standards identified in Section 4.2. If anomalies or nonconformances are discovered, the laboratory will be instructed to review the submitted data and the methods used to obtain the data. Laboratory or field QC sample results that do not meet the QA objectives will be evaluated to determine whether the sample data are usable. Corrective actions, as necessary, will be implemented per the procedures described in Section 4.11.

4.7.4 Data Validation

The data obtained from the ICP analysis (EPA method 6010B) of the samples collected as part of the confirmation soil sampling for flue dust or non-residential area soil/tailing removals will be validated according to the procedures provided in the EPA's Functional Guidelines for Inorganic Data Review

ASARCO Incorporated MFC, Inc. J:\BLDOIUM4\S344-50\AV_CZLDaign\QAPUii\QAPlin.doc 22 Jufy 2004 (EPA, 1994). If anomalies or nonconformances are discovered, the laboratory will be instructed to review the submitted data and the methods used to obtain the data. Laboratory QC or field QC sample results that do not meet the QA objectives will be evaluated to determine whether the data are potentially biased and whether data qualifiers should be applied. Corrective actions will be implemented, as necessary, per the procedures described in Section 4.11. Unless rejected by the data validator, all validated data will be considered usable for comparison to the soil removal confirmation levels or air quality action levels. Data rejected by the data validator will not be considered usable.

4.7.5 Data Management and Reporting

Field measurements and laboratory analytical results will be presented in the Construction Completion Report. The laboratory data will be tabulated to include the following:

• Sample location; • Sample identification; • Date of sample collection; • Analytical method; • Analytes and measured concentrations; • Quantitation limits; and • Laboratory qualifiers.

Copies of field and laboratory reports will be maintained by MFG during the course of the project at the site, or at MFC's Leadville office, and will be made available to EPA/CDPHE on request.

4.8 Internal Quality Control Checks

Internal QC will be achieved by collecting and/or analyzing a series of field and laboratory QC samples to ensure that the analytical results meet the measurement objectives detailed in Section 4.3. Results from analyses of QC samples are used to quantify precision and accuracy and identify any problems or limitations of those data.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344.SOVAV_CZLD«ign\QAPUn\QAPIin.(loc 23 Jufy 2004 4.8.1 Field Quality Control Checks

Field QC will be controlled by compliance with standard sample collection and handling methods and by the periodic collection of field QC samples. QC samples will be collected as blind samples so that the laboratory remains unaware of the nature of those samples and performs analyses identically to the sample analyses. The appropriate types and frequency of field QC samples depend on the sample type, sample matrix and intended data use.

Three types of quality control samples will be collected during construction-related environmental sampling: equipment blanks, field duplicates, and air filter blanks.

• Equipment blanks consist of analyte-free reagent water (i.e., ASTM Type II) poured through the sampling device or equipment, collected in a clean sampling bottle, preserved as needed, and analyzed with the samples. Equipment blanks may be used to demonstrate that sampling devices have been adequately cleaned between uses and provide representative samples. • A field duplicate sample is a second sample collected at the same location as the original sample. It is collected simultaneously with or in immediate succession to the original sample using identical recovery techniques, and it is treated in an identical manner during storage, transportation and analysis. Field duplicate sample results may be used to provide a measure of method variability, including both sampling and analytical precision. Field duplicates will be collected for dust samples, as described in the Fugitive Emissions Dust Control Plan (Appendix F of the RDR). • A filter blank consists of an air filter that has not been exposed to air drawn through the sampler. The filter blank is prepared from a unused filter that has been pre-weighed by the laboratory. The filter blank is submitted for analysis in an identical manner as the filters used for sampling, and it is analyzed for the same parameters as the sample filters. Filter blank results describe the background TSP and arsenic, cadmium and lead concentrations of filters used to collect ambient dust and may be used to assess bias introduced as a result of measurement error or blank concentrations.

4.8.1.1 Removal Confirmation Soil Analyses

Equipment blanks will be collected with removal confirmation soil samples. Field duplicates will not be collected because the soils sampled are expected to be heterogenous, and obtaining a field duplicate from a heterogeneous composite sample would not provide information about the measurement precision.

Equipment blanks associated with soil samples will be collected by pouring reagent water through the decontaminated re-usable equipment used to obtain and composite soil subsamples (e.g., soil scoops and

ASARCO Incorporated MFC, Inc. J:\BLDOI\3J44\JJ44-50\AV_CZL Doign\QAPUji\QAPtan.doc 24 • Jufy 2004 mixing bowls). One equipment blank will be collected with every 20 soil samples submitted for laboratory analysis, or a minimum of one equipment blank per soil sample type (flue dust removal or non- residential area soils/tailing removal) collected at the site. Equipment blanks associated with soil sampling will be analyzed for arsenic and lead.

4.8.1.2 Ambient Dust (TSP) Samples Filter blanks will be collected with the ambient TSP dust samples at a frequency of one for every 20 filter samples. The filter blank will be collected by containing an unused, pre-weighed filter and submitting for the same analyses as the TSP filters (TSP, lead, arsenic, and cadmium). The filter blanks will be blind blanks to the laboratory. In addition, field duplicates will be collected once each month (see Section 2.3 of the Fugitive Emissions Dust Control Plan for details.)

4.8.2 Laboratory Quality Control Checks

Laboratory quality control is necessary to control the analytical process, to assess the precision and accuracy of analytical results and to identify assignable causes for atypical analytical results. The internal QC practices described in the laboratory's Quality Assurance Plan will provide quality control for laboratory analyses. Initial calibration will be performed for all analytical methods. An independent reference standard will be used to verify initial calibration within ±10 percent. The laboratory's other QC practices vary depending on the analysis performed, as described below.

4.8.2.1 ICP Metals Analyses (Soil, Air Filters, and Equipment Blanks)

For ICP analyses, the laboratory will analyze and report the results from method blanks, laboratory control samples (LCS), analytical duplicates and matrix spike samples. These data will be used to evaluate data quality relative the measurement objectives given in Section 4.3. In addition, initial and continuing calibration verifications will be performed. Calibration results must meet the laboratory's acceptance criteria.

ASARCO Incorporated MFG. Inc. J:\BLWIW44\5J44-50\AV_CZLD«isirtQAPI«ii\QAPUii.doc 25 Jvfy 2004 4.8.2.2 Gravimetric Analyses for TSP

The precision and accuracy of gravimetric measurements will be controlled through replicate measurements and instrument calibration. One in 10 measurements will be replicates. The scale used to weigh filters will be calibrated and calibration checks will be performed at least daily. In addition, Laboratory Control Standards and Matrix Spikes will be analyzed to verify the precision and accuracy of the analytical method, as described previously.

4.9 Technical System Audits

The purpose of a quality assurance audit is to provide an assessment of the ability of the measurement system to produce data of a quality commensurate with the project's measurement objectives. In addition to documenting the performance of the sampling, analytical and data management systems, the audit provides a mechanism whereby inadequacies in the measurement systems can be identified and necessary corrective actions implemented in a timely manner.

Internal technical systems audits of field and/or laboratory activities may be performed during construction-related activities.'1 ..Internal audits will be performed by the EQAO. External systems audits may also be performed by the EPA.

An individual audit plan will be developed to provide a basis for each audit. This plan will identify the audit scope, activities to be audited, audit personnel, any applicable documents, and the schedule. Checklists will be prepared by the auditors to structure the review process and document the results of the audit.

4.9.1 Systems Audits

A technical systems audit is an on-site, qualitative review of the various aspects of a total sampling and/or analytical system. It consists of observations and documentation of all aspects of the measurement effort, including adherence to approved sampling and analysis plans, quality assurance plans and standard operating procedures. A systems audits also includes review of record keeping and data handling systems, including:

ASARCO Incorporated MFC, Inc. J:VBUX)l\53«\5J44.50\AV_CZLDt«ign\QAPIin\QAPlin.

A technical systems audit will include an audit plan, schedule, audit scope and checklists. An audit report will be prepared for the construction oversight manager with recommendations for corrective action, if needed.

4.9.2 Frequency and Scheduling

The necessity for internal systems audits will be determined by the MFG PM or EQAO. Audits will be scheduled at intervals appropriate to assure quality control for the activity type or task in progress and will be planned to coincide with appropriate activities on the project calendar. Such scheduled audits may be supplemented by additional audits for one or more of the following reasons:

• When significant changes are made in the QA plan; • When it is necessary to verify that corrective action has been taken on a nonconformance reported in a previous audit; or • When requested by MFC's PM or EQAO.

4.9.3 Audit Reports

During an audit and upon its completion, the auditor may discuss the findings with the individuals audited, and discuss and agree on corrective actions to be initiated. Minor administrative findings, which can be resolved to the satisfaction of the auditor during an audit, may not be cited as items requiring corrective action. Findings that are not resolved during the course of the audit, and findings affecting the overall quality of the project, will be noted on the audit checklists and included in the audit report.

ASARCO Incorporated . MFG, Inc. J:\BLroi\5344\J344-5IAAV_CZLDaign\QAPUiiNQAPlin.doc 27 Jllfy 2004 Audit results will be reported to MFC's PM and FPS. The audit report will be retained in the project file, and copies of audit reports will be available to EPA in the Construction Completion Report.

The PM will submit a reply to the audit report addressing each finding cited, the corrective action(s) to be taken and a schedule for implementation. This reply will be sent to the auditor and will be filed in the project file. The findings cited in the audit and addressed in the reply will be treated as nonconformances and will become subject to review at the time of the next audit.

4.10 Calculation of Data Quality Indicators

The parameters that will be used to assess data quality include accuracy, precision, completeness and representativeness. Definitions of these parameters are provided below. Since the environmental sampling data will be used to evaluate and direct construction-related activities, the accuracy and representativeness of the data will be considered the data quality parameters of most importance. The field and laboratory QC samples and methods, which will be employed to assess the data quality, are discussed in Section 4.8.

4.10.1 Precision

Precision (analytical error) is the level of agreement among repeated measurements of the same characteristic. Data precision will be assessed by determining the agreement among replicate measurements of the same sample and measurements of duplicate samples. As discussed in Section 4.8, these samples will include MS/MSD samples, LCS/LCSD samples, and field duplicates. The comparison is made by calculating the relative percent difference (RPD), given by:

RPD(%) = ^'"^l x 100

where: Si = measured sample concentration; and §2 = known sample or duplicate concentration.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5J44\5344-50\AV_CZL D«ign\QAPIin\QAPI«n.(toc 28 Jufy 2004 The goals for precision are provided in Section 4.3, Quality Assurance Objectives. When analytes are present at concentrations below or near the quantitation limit, precision will be evaluated using duplicates of a matrix-spike sample.

4.10.2 Accuracy ,

Accuracy (bias) is the degree of difference between measured or calculated value and the true value. Data accuracy will be evaluated using sample recoveries, expressed as the percentage of the true (known) concentration, from laboratory-spiked samples (including matrix spikes) and from standard reference materials (i.e., laboratory control standards) generated by the analytical laboratory (see Section 4.8). Equipment, field and laboratory blanks will be analyzed to quantify artifacts introduced during sampling, transport, or analysis which may effect the accuracy of the data. The percentage recovery for spiked samples will be used to evaluate the accuracy of analyses as given by:

Recovery(%) = ~ x 100

where: A = measured concentration of the spiked sample; B = concentration of unspiked sample; and C = amount of spike added.

In addition, the initial and continuing calibration results will be reviewed to verify that the sample concentrations are accurately measured by the analytical instrument. The project goals for accuracy are provided in Section 4.3, Quality Assurance Objectives.

4.10.3 Completeness

Completeness is the percentage of valid measurements (data points) obtained, as a proportion of the number of measurements (data points) planned for the investigation. Completeness is affected by such factors as sample-bottle breakage,, and acceptance/non-acceptance of analytical results. Percentage completeness (C) is given by:

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\J344-50UV_CZLDtsisn\QAPIjn\QAPUn.doc 29 July 2004 = -xlOO

where: V = number of valid measurements (data points) obtained by the investigation; and

P = number of measurements (data points) planned for the investigation.

Completeness goals are provided in Section 4.3, Quality Assurance Objectives.

4.10.4 Representativeness

Representativeness is a qualitative objective, defined as the degree to which data accurately and precisely represent the medium being studied. Representativeness is achieved by collecting a sufficient number of unbiased samples, as determined through the QA objectives. Representativeness will be evaluated based on blank results (field and laboratory), laboratory methods and QC, sampling locations and methods, and sampling frequencies. Samples will be collected in accordance with the methods described in this CQAP to ensure that the samples are representative of the site conditions. The samples will be contained, preserved, and stored appropriately, as discussed in Section 4.5. Laboratory blanks, calibration standards and methods, and QC sample results will be reviewed as described in Sections 4.6 and 4.7 to ensure that analytical results are representative of actual site conditions.

4.11 Corrective Action

Nonconforming equipment, items, activities, conditions and unusual incidents that could affect compliance with project quality assurance goals will be identified, controlled and reported in a timely manner. A nonconformance is defined as a malfunction, failure, deficiency, or deviation which renders the quality of an item unacceptable or indeterminate. Project staff, a project subcontractor, or analytical laboratory personnel will inform the FPS or Project Chemist (as applicable) immediately when a nonconformance is identified or suspected. The Project Chemist or FPS will in turn notify the EQAO to discuss the nonconformance and identify an appropriate response, the "corrective action".

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5344-50\AV_CZLDuign\QAPIin\QAPIui.doc 30 Jllfy 2004 If the analytical results of laboratory control samples fall outside of the project's control limits, corrective actions will be initiated by the laboratory. The EQAO will also review field data and narrative records related to the samples in question for the potential source of the error. If the laboratory cannot correct the situation that caused the nonconformance and an out-of-control situation continues to occur or is expected to occur, the laboratory will immediately contact MFC's PM or EQAO. Completion of corrective action should be evidenced by data once again falling within prescribed quality control limits. If an error in laboratory procedures or sample collection and handling procedures can not be found, MFG's PM will review the results and assess whether reanalysis or resampling is required.

4.12 Quality Assurance Reports

Effective management of the environmental sampling effort requires timely assessment and review of field activities, which in turn requires effective interaction and feedback between the FPS, EQAO and PM. i

The FPS will be responsible for documenting any conditions or situations that might adversely affect data quality. These conditions should be communicated in writing to the EQAO and PM. In addition, routine quality assurance reports will be prepared by the FPS for the EQAO and PM. These reports will include elements such as project activities, modifications to or deviations from the CQAP and any corrective actions taken, status of unresolved problems and audit results. These reports may be provided as informal memos or other documented presentations.

Data quality evaluations will be prepared by the EQAO, based on the procedures described in Section 4.7. The usability of data will be determined and described. The impact of any deviations or exceptions to the method protocols or performance indicators will also be described. This information will be provided in data quality reports prepared for the PM and included in the Construction Completion Report.

ASARCO Incorporated MFC, Inc. J:\BLDO I\H44\JM4-5

This section presents a summary of the construction documentation necessary for the startup phase, the construction inspection and QA/QC procedures, the construction management and contract administration procedures, and the construction phase closeout. Relevant information will be reported in the Construction Completion Report.

5.1 Project Startup Phase

The project startup phase includes the period between the award of the remediation construction contract(s) and mobilization of the construction contractor(s) to the site. The principal item required for planning during this phase of the project is development of a submittal control sheet listing all required contractor submittals in the order in which they appear in the technical specifications. This will be prepared during the construction bidding process

5.2 Construction Phase

The construction phase of the project includes the period between contractor mobilization and substantial completion of the project. The basic reporting required for construction inspection during this phase of the project will include the daily record of work progress (by the FPS), which will include the weather conditions, the contractor's work force, site visitors, the equipment used and the general construction activities. Records documenting activities associated with air monitoring and stormwater management and control will be maintained, per the requirements of the Fugitive Emissions Dust Control Plan (Appendix F of the RDR) and the Stormwater Management Plan (Appendix G of the RDR). Additional reporting procedures will include the actual log of contractor submittals including the action taken on each submittal. Records for QC and QA activities described in this CQAP will be maintained by the FPS.

5.3 Construction Closeout Phase

The construction phase closeout includes the period just before substantial completion to final completion of the work. Reporting during this phase of the project will include the punch list which identifies all work or corrective action remaining before acceptance of the particular phase of the project. The

ASARCO Incorporated MFC, Inc. J:\BLDOIU3WUJ44-50\AV_CZLDwign\QAPlin\QAPlin.doc 32 Juty 2004 certificate of substantial completion will also be required during this closeout phase which will establish a specific date that will allow project acceptance and final payment even though minor tasks and demobilization remain to be completed. This closeout phase will include the pre-certification and the certification inspections required by the Work Area Management Plan.

ASARCO Incorporated MFG. Inc. J:\BLDOI\JW4\J344-50\AV_CZLDesisn\QAPUn\QAPUn.doc 33 My 2004 6.0 REFERENCES

U.S. Environmental Protection Agency (EPA), 1994. USEPA Contract Laboratory Program National Functional Guidelines for Inorganic Data Review. Office of Solid Waste and Emergency Response. February.

U.S. Environmental Protection Agency (EPA), 1996. Compendium of Standard Operating Procedures for the California Gulch CERCLA Site Leadville, Colorado. Revision 0.0. April 1996.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5344.30\AV_CZLDcjign\QAPIin\QAPItn.doc 34 Jufy 2004 TABLES TABLE 4-1 QUANTITATIVE MEASUREMENT OBJECTIVES FOR ANALYSES OF REMOVAL CONFIRMATION SOIL SAMPLES

Quantitation Parameter Analytical Method Precision Accuracy Limit Completeness

LCS/LCDS RPD <20% LCS recovery = 80 to 120%- 20mg/Kg Arsenic ICP (EPA Method 6010B) MS/MSDRPD<30% MS recovery = 75 to 125% 100%

LCS/LCSDRPD<20% LCS recovery = 80 to 120% lOmg/Kg Lead ICP (EPA Method 601 OB) MS/MSD RPD < 30% MS recovery = 75 to 125% 100%

RPD = Relative Percent Difference LCS = Laboratory Control Standard MS = Matrix Spike

J:\BLDOI\5344\5344-50\AV_CZL Design\QA Plan\TabIes.doc July 2004 TABLE 4-2 ANALYTICAL METHODS, HOLDING TIMES, AND QUANTITATION LIMITS

Analytical Container & Holding Sample Type Parameter Method Quantitation Limit Preservation Storage Time Keep dry at Confirmation Arsenic EPA6010B 20 mg/kg (As) Clean Bags ambient 6 months Soils Lead 10mg/kg(Pb) temp. Dust Sampling TSP Gravimetric 200 ug Keep dry at Arsenic 0.15ug/filter(As)" ambient Clean Bags 6 months Cadmium EPA 6020 0.05 ug/filter (Cd) temp. Lead 0.05ug/fiIter(Pb)' Equipment EPA 206.2 Arsenic 0.001mg/L(As) Blank (GFAA) 500 mL, plastic 4±2°C 6 months Water EPA 239.2 acid to pH<2 Lead 0.001mg/L(Pb) (GFAA)

*The quantitation limits will be 0.007 tig/m3 for lead and cadmium and 0.02 ug/m3 for arsenic, assuming a sampling rate of 5 liters per minute for a 24-hour period.

J:\BLDOI\5344\5344-50\AV_CZL Dcsign\QA Plan\Tables.doc July 2004 FIGURES '7A *

LEGEND: ASARCO rj CONFIGURATION OF SMELTER OPERATIONS IN AV/CZL SITE (OU5) - CALIFORNIA GULCH 1 1937 FROM SANBORN FIRE INSURANCE MAPS. FIGURE 4-1 REMAINING SITE FEATURES IDENTIFIED BY FLUE DUST REMOVAL AREAS AND ASSOCIATED SURVEY, 1998. REMOVAL CONFIRMATION DECISION UNITS - BLAST FURNACE/BAGHOUSE AREA DUST EXCAVATION AREAS SCALE PROJECT: 010179:3 [DATE: JULY 2004 BLAST FURNACE DECISION UNIT ID NUMBER • til U-BF1 REV: BY: BWB'T'CHECKED: ACK FEET MFG. Inc. consulting scientists and engineers : L_ LFOOTPRINTS t)F FORMED FLUES

~1 CONCRETE WALL

LEGEND: ASARCO CONFIGURATION OF SMELTER OPERATIONS IN [)(J — RR2 ROASTING PLANT DECISION UNIT ID NUMBER AV/CZL SITE (OU5) - CALIFORNIA GULCH 1937 FROM SANBORN FIRE INSURANCE MAPS. FIGURE 4-2 REMAINING SITE FEATURES IDENTIFIED BY FLUE OUST REMOVAL AREAS AND SURVEY, 1998. ASSOCIATED REMOVAL CONFIRMATION DECISION UNITS - ROASTING PLANT AREA FLUE DUST EXCAVATION AREAS PROJECT: 01 01 79.3 T DATE: JULY 2004 ADJACENT AREAS TO BE SAMPLED TO EVALUATE IF FLUE DuST IS PRESENi RFV- RY- RWB! CHECKED: AOK 50 FEET MFC, Inc. consulting scientists and engineers ATTACHMENT ATTACHMENT ATTACHMENT A STANDARD OPERATING PROCEDURES MFG SOP No. 1 Rev. No. 1 Date: August 2000 Page 1 of3

MFG, Inc.

STANDARD OPERATING PROCEDURE No. 1

FIELD DOCUMENTATION

1.0 SCOPE AND APPLICABILITY

This Standard Operating Procedure (SOP) describes the protocol for documenting field activities. MFG field personnel shall document field activities on formatted field records and other appropriate data sheets. These formatted record and data sheets will be part of the MFG project file; all forms must be filled out carefully and completely by one of the personnel actually performing the field activities.

2.0 PROCEDURES

2.1 Daily Field Record

The MFG field representative will prepare a Daily Field Record form (Figure SOP-1-1) for each day of field work. Documentation on the multiple-page form will include:

A. Project identification;

B. Date;

C. Time on job (beginning and ending time);

D. Weather conditions;

E. Activity description;

F. List of personnel and visitors on site;

G. Safety equipment used and monitoring performed;

H. Waste storage inventory (if any);

MFG, Inc. MFG SOP No. 1 Rev. No. 1 Date: August 2000 Page 2 of3

I. Chronological record of activities and events;

J. Comments and variances from project work plan;

K. Content of telephone conversations; and

L. Signature of the MFG field representative.

The MFG field representative will document all details that would be necessary to recreate the day's activities and events at a later time, using as many additional sheets as necessary. The Daily Field Record also will be used to document field activities that may not be specified on other field record forms. Other activity-specific documentation requirements to be recorded on the Daily Field Record are discussed in the MFG Standard Operating Procedure for each activity.

3.0 DOCUMENTATION

3.1 Field Record Forms

In addition to the Daily Field Record, MFG field personnel will complete specific MFG field record forms applicable to the field activities being conducted. The procedures for completion of activity-specific field record forms are presented in the applicable MFG Standard Operating Procedures. MFG field record forms include:

Daily Field Record (SOP No. 1);

• Chain-of-Custody Record and Request for Analysis (SOP No. 2);

• Field Log of Borehole by Cuttings (SOP No. 4);

• Field Log of Borehole by Coring (SOP No. 4);

• UST Closure Field Record (SOP No. 3);

• Well Construction Summary (SOP No. 6);

• Well Development Record (SOP No. 7);

MFG, Inc. MFGSOPNo. 1 Rev. No. 1 Date: August 2000 Page 3 of3

• Geophysical Log (SOP No. 5);

• Water Level Monitoring Record (SOP No. 11);

• Pumping Test Record (SOP No. 14);

Eh Data Sheet (SOP No. 13);

• Groundwater Sampling Record (SOP No. 12); and

• Surface Water Sampling Record (SOP No. 12).

Additional field record forms and applicable procedures may be created for project-specific activities, as necessary..

3.2 Records Management

All original field forms will be filed with the appropriate project's records.

4.0 QUALITY ASSURANCE

4.1 Form Review and Filing

All completed field forms will be reviewed by the Project Manager or project designated QA/QC reviewer. Any necessary corrections will be made in pen with a single-line strike out that is initialed and dated.

MFG, Inc. DAILY FIELD RECORD DATE: PAGE 1 of

Project No.: Project Name: AM AM Location: Time on Job: PM to: PM Weather Conditions: Activity: PERSONNEL ON SITE Name Company Time In Time Out

VISITORS ON SITE Name Company/Agency Time In Time Out

PERSONAL SAFETY Protective Gloves Hard Hat Tyvek Coveralls (W/Y) Protective Boots Safety Goggles/Glasses - Mask Respirator Other Safety Equipment (describe): Monitoring Equipment: Field Calibration: WASTE STORAGE INVENTORY Container Type Container I.D. Description of Contents and Quantity Location

Signature of Field Representative: Date:

MFC, INC. Notes: 4900 PEARL EAST CIRCLE SUITE 300W BOULDER, CO 80301 (303)447-1823

J:\BL001\5344\5344-50\AV_CZL OESIGN\QA PUN\DAILYFLD_REC.DOC DAILY FIELD RECORD (cont) DATE: PAGE of TIME DESCRIPTION OF DAILY ACTIVITIES & EVENTS

COMMENTS & CHANGES FROM WORK PLAN

TIME TELEPHONE CONVERSATION RECORD

MFC, INC. Lasignature of Field Representative: 4900 PEARL EAST CIRCLE SUITE 300W BOULDER, CO 80301 f (303)447-1823

J:\BLD01\5344\5344-50\AV_CZI. DESIGKXQA PLAN\DAILYRD_REC.DOC MFC SOP No. 2 Rev. No. 1 Date: August 2000 Page 1 of 7

MFC, Inc.

STANDARD OPERATING PROCEDURE No. 2

SAMPLE CUSTODY, PACKAGING AND SHIPMENT

1.0 SCOPE AND APPLICABILITY

This Standard Operating Procedure (SOP) describes the protocol to be followed for sample custody, packaging and shipment. The procedures presented herein are intended to be general in nature. If warranted, appropriate revisions may be made when approved in writing by the MFG Project Manager.

This SOP applies to any liquid or solid sample that is being transported by the sampler, a courier or an overnight delivery service.

2.0 PROCEDURES

The objectives of this packaging and shipping SOP are: to minimize the potential for sample breakage, leakage or cross contamination; to provide for preservation at the proper temperature; and to provide a clear record of sample custody from collection to analysis.

2.1 Packaging Materials

The following is a list of materials that will be needed to facilitate proper sample packaging:

X Chain-of-Custody Record forms (see Figure SOP-2-1);

X Coolers (insulated ice chests) or other shipping containers as appropriate to sample type;

X Transparent packaging tape;

X Zip-lock type bags (note: this is used as a generic bag type, not a specific brand name);

MFG, Inc. MFC SOP No. 2 Rev. No. 1 Date: August 2000 Page 2 of7

X Protective wrapping and packaging material;

X Contained ice (packaged and sealed to prevent leakage when melted) or "Blue Ice"; and

X Chain-of-Custody seals.

2.2 Sample Custody from Field Collection to Laboratory

After samples have been collected, they will be maintained under chain-of-custody procedures. These procedures are used to document the transfer of custody of the samples from the field to the designated analytical laboratory. The same chain-of-custody procedures will be used for the transfer of samples from one laboratory to another, if required.

The field sampling personnel will complete a Chain-of-Custody Record and Request for Analysis form (CC/RA form, Figure SOP-2-1) for each separate container of samples to be shipped or delivered to the laboratory for chemical or physical (geotechnical) analysis. Information contained on the triplicate, carbonless form will include:

1. Project identification;

2. Date and time of sampling;

3. Sample identification;

4. Sample matrix type;

5. Sample preservation method(s);

6. Number and types of sample containers;

7. Sample hazards (if any);

8. Requested analysis(es);

9. Requested sample turnaround time;

10. Method of shipment;

11. Carrier/waybill number (if any);

MFC, Inc. MFC SOP No. 2 Rev. No. 1 Date: August 2000 Page 3 of 7

12. Signature of sampling personnel;

13. NameofMFG Project Manager;

14. Signature, name and company of the person relinquishing and the person receiving the samples when custody is being transferred;

15. Date and time of sample custody transfer; and

16. Condition of samples upon receipt by laboratory.

The sample collector will cross out any blank space on the CC/RA form below the last sample number listed on the part of the form where samples are listed. The samples will be carefully packaged into shipping containers/ice chests.

The sampling personnel whose signature appears on the CC/RA form is responsible for the custody of a sample from time of sample collection until the custody of the sample is transferred to a designated laboratory, a courier, or to another MFG employee for the purpose of transporting a sample to the designated laboratory. A sample is considered to be in their custody when the custodian: (1) has direct possession of it; (2) has plain view of it; or (3) has securely locked it in a restricted access area.

Custody is transferred when both parties to the transfer complete the portion of the CC/RA form under "Relinquished by" and "Received by." Signatures, printed names, company names, and date and time of custody transfer are required. Upon transfer of custody, the MFG sampling personnel who relinquished the samples will retain the third sheet (pink copy) of the CC/RA form. When the samples are shipped by a common carrier, a Bill of Lading supplied by the carrier will be used to document the sample custody, and its identification number will be entered on the CC/RA form. Receipts of Bills of Lading will be retained as part of the permanent documentation in the MFG project file.

MFG, Inc. MFG SOP No. 2 Rev. No. 1 Date: August 2000 Page 4 of 7

2.3 Sample Custody Within Laboratory

The designated laboratory will assume sample custody upon receipt of the samples and CC/RA form. Sample custody within the analytical laboratory will be the responsibility of designated laboratory personnel. The laboratory will document the transfer of sample custody and receipt by the laboratory by signing the correct portion of the CC/RA form. Upon receipt, the laboratory sample custodian will note the condition of the samples, by checking the following items:

1. Agreement of the number, identification and description of samples received by comparison with the information on the CC/RA form; and

2. Condition of samples (no air bubbles in VOA containers; any bottle breakage; leakage, cooler temperature, etc.).

If any problems are discovered, the laboratory sample custodian will note this information on the "Laboratory Comments/Condition of Samples" section of the CC/RA form, and will notify the MFG sampling personnel or Project Manager immediately. The MFG Project Manager will decide on the final disposition of the problem samples.

The laboratory will retain the second sheet (yellow copy) of the CC/RA form and return the first sheet (white original) to MFG with the final laboratory report of analytical results. The original of the CC/RA form will be retained as part of the permanent documentation in the MFG project file.

A record of the history of the sample within the laboratory containing sample status and storage location information will be maintained in a logbook, or a computer sample tracking system, at the laboratory. The following information will be recorded for every sample access event:

1. Sample identification;

2. Place of storage;

3. Date(s) and time(s) of sample removal and return to storage;

4. Accessor's name and title;

5. Reason for access; and

MFG, Inc. MFC SOP No. 2 Rev. No. 1 Date: August 2000 Page 5 of 7

6. Comments/observations (if any).

The laboratory will provide MFG with a copy of the logbook or computer file information pertaining to a sample upon request.

2.4 Sample Custody During Inter-Laboratory Transfer

t • If samples must be transferred from one laboratory to another, the same sample custody procedures discussed above will be followed. The designated laboratory person (sample custodian) will complete a CC/RA Record (MFG form or similar) and sign as the originator. The laboratory relinquishing the sample custody will retain a copy of the completed form. The laboratory receiving sample custody will sign the form, indicating transfer of custody, retain a copy, and return the original record to MFG with the final laboratory report of analytical results. The CC/RA Record will be retained as part of the permanent documentation in the MFG project file.

2.5 Packaging and Shipping Procedure

Be sure that all sample containers are properly labeled and all samples have been logged on the Chain-of-Custody Request for Analysis form (CC/RA, SOP-2-1) in accordance with the procedures explained above and in the MFG SOPs entitled WATER QUALITY SAMPLING and SOIL/SEDIMENT SAMPLING FOR CHEMICAL ANALYSIS.

All samples should be packed in the cooler so as to minimize the possibility of breakage, cross- contamination and leakage. Before placing the sample containers into the cooler, be sure to check all sample bottle caps and tighten if necessary. Bottles made of breakable material (e.g., glass) should also be wrapped in protective material (e.g., bubble wrap, plastic gridding, or foam) prior to placement in the cooler. Place each bottle or soil liner into two zip-lock bags to protect from cross-contamination and to keep the sample labels dry. Place the sample containers upright in the cooler. Avoid stacking glass sample bottles directly on top of each other.

MFG, Inc. MFC SOP No. 2 Rev. No. 1 Date: August 2000 Page 6 of 7

If required by the method, samples should be preserved to 4°C prior to the analysis. Water ice or "blue ice" will be used to keep the sample temperatures at 4°C. The ice will be placed in two zip- lock bags if the samples are to be transported by someone other than the MFG sampler (e.g., a courier or overnight delivery service). Place the zip-lock bags of ice in between and on top of the sample containers so as to maximize the contact between the containers and the bagged ice. If the MFG sampler is transporting the samples to the laboratory shortly after sample collection, the water ice may be poured over and between the sample bottles in the cooler.

% If there is any remaining space at the top of the cooler, packing material (e.g., styrofoam pellets or bubble wrap) should be placed to fill the balance of the cooler. After filling the cooler, close the top and shake the cooler to verify that the contents are secure. Add additional packaging material if necessary.

When transport to the laboratory by the MFG sampler is not feasible, sample shipment should occur via courier or overnight express shipping service that guarantees shipment tracking and next morning delivery (e.g., Federal Express Priority Overnight). In this case, place the chain-of- custody records in a zip-lock bag and place the bag on top of the contents within the cooler. Tape the cooler shut with packaging tape. Packaging tape should completely encircle the cooler, and a chain-of-custody seal should be signed and placed across the packaging tape, and across at least one of the opening points of the container.

Retain copies of all shipment records provided by the courier or overnight delivery service and maintain in the project's file.

2.6 Documentation and Records Management

Daily Field Records or a field notebook with field notes will be kept describing the packaging procedures and the method of shipments. Copies of all shipping records and chain-of-custody records will be retained in the project files.

MFG, Inc. MFC SOP No. 2 Rev. No. 1 Date: August 2000 Page 7 of 7

3.0 QUALITY ASSURANCE

The Project Manager or designated QA reviewer will check and verify that documentation has been completed and filed per this procedure.

MFG, Inc. CHAIN-OF-ClJSTODY RECORD AND REQUEST FOR ANALYSIS MFC, INC. coc N0.

A jstin Office Boston Office Boulder Office Missoula Office Osbum Office Port Lavaca Office San Francisco Office Seattle Office 8!KM Business Park Dr. 500 W Cummlnga Park 4900 Peart E. Circle 215 S. 3 St. West 609 E. Mullan Avenue 320 E. Main 71 Stevenson St. S1450 19203 36" Avenue W A JStin.TX 78759 Suite #1050 Suite #300W Missoula. MT 59801 Osbum. ID 83849 Port Lavaca. TX 77979 San Francisco. CA 94105 Suite #101 TlEL: (512) 338-1667 Wobum. MA 01801 Boulder, CO 80301 TEL: (406) 728-4600 TEL: (208) 556-681 1 TEL: (512) 552-8839 TEL: (415) 495-7110 Lynnwood. WA 98036 F/\X (512) 338-1331 TEL: (781)937-0500 TEL: (303) 447-1823 FAX (406) 728-4698 FAX (208) 556-7271 FAX (512)553-6115 FAX (415) 495-7107 TEL: (425) 778-8252 FAX: (781 )937-0578 FAX (303) 447-1 836 FAX' (425) 771-8842

PROJECT NO.: PROJECT NAME: PAGE: OF: SAMPLER (Signalure): PROJECT MANAGER: DATE: fv1ETHOD OF SHI PMENT: CARRIER/WAYBILL NO.: DESTINATION:

SAMPLES ANALYSIS REQUEST Sample Collection Preservation Containers Constituents/Method Handling Remarks e iii 5_ *x fO "3 N Field Q LU Q X o d =J -5 O. CO Lab Sample 75 0 z CO O

: : LABORATORY COMMENTS/CONDITION OF SAMPLES '' '•. •- ••, . ./•:.;;.;; •>:.•;- ' .•'•"•^• \"-',-i} TOTAL NUMBER OF CONTAINERS Cooler Temp:

RELINQUISHED BY: RECEIVED BY: DATE TIME SIGNATURE PRINTED NAME COMPANY SIGNATURE PRINTED NAME COMPANY

LABORATORY

•BEC HOIK M-tquma /IM-nououKiut SO-ioi SL-auOgs p.pttafeuii /»-«* Of. offer Comtanv P-ftaOc G-gou T-Wfcn B-trau or-oOw HMnv r-mratf u-iMDlBrad dSTRDUTIOM: HMO FM) Copy VEU.O W UOmttry Copr VWyfTE ffofun » Or^Mtor

FIGURE SOP-2-1. CHAIN-OF-CUSTODY RECORD AND REQUEST FOR ANALYSIS MFC SOP California Gulch Superfund Site AV/CZL Construction QAP Date: May 2001 Page 1 of4

MFC, Inc.

STANDARD OPERATING PROCEDURE FOR REMOVAL CONFIRMATION SOIL SAMPLE COLLECTION

1.0 SCOPE AND APPLICABILITY

This Standard Operating Procedure (SOP) describes the protocols to be followed when soil samples are collected for chemical analysis to confirm the removal of flue dust or of non- residential area soils/tailing during remedial action activities at the Arkansas Valley Smelter and Colorado Zinc-Lead Mill Site, Operable Unit 5 of the California Gulch Superfund Site in Leadville, Colorado.

2.0 PROCEDURES

2.1 Surface Soil Sample Collection

This section describes sampling of soils from the bottom of excavations associated with removal of flue dust or of non-residential area soils/tailing. The collected samples will be placed in appropriate sample containers, as designated by the laboratory, for the parameters to be analyzed.

2.1.1 Surface Soil Sampling

Soil will be removed using a spade and, if necessary, a post-hole digger to the top of the targeted sampling interval.

A. Direct Sampling Method - A stainless-steel or, as appropriate, plastic instrument (trowel, scoop) will be used to recover the sample directly into appropriate containers provided by the analytical laboratory.

MFC, Inc. MFC SOP California Gulch Superfund Site AV/CZL Construction QAP Date: May 2001 Page 2 of 4

B. Manual Core Sampler Method — A slide-hammer core sampler with brass or stainless steel liners may be used to recover a relatively undisturbed core sample. Extension sections may be added to reach deeper sampling intervals. This method is recommended for samples that will be analyzed for volatile organic compounds. i C. Hand Auger Method — A hand auger with stainless-steel auger and sampler sections may be used to advance and sample the boring. Extension sections may be added to reach deeper sample intervals.

In flue dust removal areas, decision units will be established with maximum areas of 10,000 square feet. For non-residential area soil or tailing removal areas decision units will be established with maximum areas of 22,500 square feet. Each decision unit will be divided into four approximately equal areas (quadrants). A single soil sample will be collected from the 0 to 6 inch depth interval from each quadrant. The locations will be selected at random by MFC's Field Project Supervisor. The four individual samples will be composited into a singe sample to represent the decision unit.

2.2 Sample Preservation

The soil sample will be quickly inspected for color, appearance, and composition, then capped immediately. If brass or stainless steel liners are used, the ends of the tube will be covered with Teflon® sheeting and then capped with clean polyethylene slip caps. The capped ends will be sealed with duct tape. The sample will be placed in a plastic, ziplock bag and stored (in an ice- cooled, insulated chest, if necessary) until delivery to the laboratory.

2.3 Sample Labeling

The sample container will be labeled with self-adhesive tags. Each sample will be labeled with the following information in waterproof ink:

A. Project identification;

B. Sample identification;

MFG, Inc. MFC SOP California Gulch Superfund Site AV/CZL Construction QAP Date: May 2001 Page 3 of4

C. Date and time sample was obtained;

D. Sample Depth Interval (feet below ground level); and

E. First initial and last name of sample collectors).

2.4 Documentation and Record Management

2.4.1 Daily Field Record

An MFG field representative will document the activities of each day of field work chronologically in accordance with the procedures contained in the MFG SOP entitled FIELD DOCUMENTATION. For soil sampling, the Daily Field Record (included in the MFG SOP entitled FIELD DOCUMENTATION) or field notebook entries should include the following items:

A. Decontamination Record: Decontamination method, source of tap water or deionized water, type of detergent or other cleaning agent;

B. Sample Inventory Record: Sample identification, location, date and time of sampling, sample depth interval, analyses requested and analysis methods;

C. Sampling Location Map: Surface soil sampling only, include scale, orientation, sample locations tied into a permanent reference point and sample identifications; and

D. Sampling Equipment Record: Description of sampling methodology and equipment including unique equipment identification, if available.

Copies of these records will be placed in the project files. Sample location and depth information should also be included in any electronic database maintained for the project.

MFG, Inc. MFC SOP California Gulch Superfund Site AV/CZL Construction QAP Date: May 2001 Page 4 of4

2.4.2 Sample Custody

A Chain-of-Custody and Request for Analysis (CC/RA) form will be filled out for every sampling event or shipment, whichever is more frequent. Sample custody procedures and CC/RA form are discussed in the MFC SOP entitled SAMPLE CUSTODY, PACKAGING AND SHIPMENT.

3.0 QUALITY ASSURANCE/QUALITY CONTROL

3.1 Equipment Cleaning

The sampler, liners, polyethylene end caps, parting knife, and any tools used in the assembly and disassembly of the sampler will be cleaned before and after each use. Equipment will be cleaned by scrubbing with a stiff brush using a laboratory-grade detergent/water solution, followed by rinsing with clean, potable, municipal water, then rinsing with distilled or deionized water. Alternatively, the equipment may be steam cleaned followed by rinsing with distilled or deionized water. An acid rinse (0:1 N HC1) or solvent rinse (i.e., hexane or methanol) may be used to supplement these cleaning steps if tarry or oily deposits are encountered. The acid or solvent rinse will be followed by thoroughly rinsing with municipal water and then with distilled or deionized water. After cleaning, equipment will be packaged and sealed in plastic bags or other appropriate containers to minimize contact with dust or other contaminants.

3.2 Record Review

The project manager or designated QA reviewer will check and verify that documentation has been completed and filed per this procedure and the other procedures referenced herein.

MFG, Inc. APPENDIX F

FUGITIVE EMISSIONS DUST CONTROL PLAN Fugitive Emissions Dust Control Plan for Remedial Action Construction at the The Arkansas Valley Smelter and Colorado Zinc-Lead Mill Site Operable Unit 5 (OU5)

California Gulch Superfund Site Leadville, Colorado

July 2004

Prepared/or:

ASARCO Incorporated 495 East 51st Avenue Denver, CO 80216-2098

Prepared by:

MFC, Inc. consulting scientists and engineers 4900 Pearl East Circle Suite 300W Boulder, CO 80301 (303)447-1823 FAX 447-1836 TABLE OF CONTENTS

LIST OF TABLES , ii LIST OF ATTACHMENTS ii 1.0 INTRODUCTION 1 2.0 , MONITORING APPROACH 2 2.1 Monitoring Equipment and Parameters Measured 2 2.2 Sampling Real-time TSP Concentrations 3 2.3 Sampling for TSP and Metals Concentrations 5 2.4 Meteorological Monitoring 7 2.5 Personal Exposure Air Monitoring „... 8 3.0 FUGITIVE DUST ACTION LEVELS AND CONTROL MEASURES 9 3.1 Dust Control Measures 9 3.2 Action Levels 10 4.0 MONITORING PROGRAM REVIEW AND MODIFICATION ...12

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\Duu Control PlirrtDmp.doc 1 Jllfy 2004 LIST OF TABLES

Table 1. Protection Program Action Levels

LIST OF ATTACHMENTS

Attachment A Standard Operating Procedure for Real-Time Dust Monitoring Attachment B Standard Operating Procedure for Portable Dust Monitoring

ASARCO Incorporated MFG. Inc. J:\BLDOl\5344\5J44-5CM>un Control Plin\Dmp.doc 11 Jufy 2004 1.0 INTRODUCTION

This document presents the Fugitive Emissions Dust Control Plan (Plan) for the remedial action construction at the Arkansas Valley (AV) and Colorado Zinc-Lead (CZL) Mill sites ("AV/CZL site"), Operable Unit 5 (OU5) of the California Gulch Superfund Site in Leadville, Colorado. This Plan complies with the Applicable or Relevant and Appropriate Requirements (ARARs) identified in EPA's Record of Decision (September 2000). More specifically, it is intended to meet the applicable requirements of Regulation Nos. 1 and 8 of the Colorado Air Pollution Prevention and Control Act. Although unrelated to this Plan, an Air Pollution Emission Notice (APEN) will also be filed as required by Regulation 3.

ASARCO Incorporated MFG. Inc. J:\BLDO I \5344\5344.5S\Dust Control Plui\Dmp.doc 1 July 2004 2.0 MONITORING APPROACH

During the course of the remedial construction activities at the AV/CZL site, movement of equipment and vehicles in work areas may liberate dust in dry and windy weather conditions. The primary concern with respect to dust is protection of human health through compliance with the State and Federal air quality standards. The Colorado Ambient Air Quality Standard (CAAQS) in Regulation 8 requires ambient lead concentrations not to exceed 1.5 |ig/m3 averaged over a 30-day period. The National Ambient Air Quality Standard (NAAQS) is less restrictive in that the ambient lead concentration cannot exceed 1.5 (ig/m3 over a three-month period. State and Federal standards for participate matter formerly based on total suspended particulate (TSP) concentrations have been replaced by NAAQS standards for particulate matter less than 10 microns (PMio) and less than 2.5 microns (PM2.s) in diameter. Those standards require PM]0 concentrations less than 1 50 |ig/m3 and PMa j concentrations less than 65 ug/m3 based on a 24-hour average. Average annual 3 PM]o and PM2.s standards are 50 and 15 fig/m , respectively.

The effectiveness of dust control measures in meeting these standards will be evaluated using real-time monitoring equipment and laboratory analysis of dust samples. The real-time monitoring equipment will be used to determine the immediate effectiveness of fugitive dust control measures. Exceedances of the established action levels for TSP will trigger the implementation of additional dust control measures or temporary suspension of activities. At the same time, filter samples of the ambient dust will also be collected for analysis for lead, cadmium, and arsenic. These data will be used to: (1) document compliance with the standards given above; (2) help identify the source and nature of the dust; and (3) assess the potential for offsite, airborne transport of arsenic, cadmium, and lead.

2.1 Monitoring Equipment and Parameters Measured

Real-time monitoring of ambient TSP concentrations will be conducted with a personal DataRAM (referred to as a MiniRAM) manufactured by ME, Incorporated. The MiniRAM is a miniature real-time aerosol monitor/data logger that is able to measure dust concentrations over a range of 0.001 to 400 mg/m3. The MiniRAM is equipped with an audible alarm that sounds whenever a user-specified level is exceeded. The two-line LCD continuously displays real-time and time-weighted average (TWA) concentration values.

ASARCO Incorporated MFC, Inc. J:\BLDOI\JM4\5344-50\Dun Control PluiVDntp.doc 2 Jllfy 2004 Filter samples of the ambient dust will be collected with an Airmetrics MINFVOL sampler. A MINIVOL sampler draws ambient air at a rate of 5 liters per minute through a pre-weighed 47-mm Teflon filter, where the particles are deposited. The portable MINIVOL is compact, lightweight, battery-operated, and constructed from durable PVC.

The MINIVOL will sample TSP. Although PM10and PM2.5 inlets are available, the TSP particle size fraction is preferred primarily because: 1) it is a conservative estimate of individual size fractions; and 2) the lead NAAQS is based on the TSP size fraction. Exposed filters will be delivered to the designated analytical laboratory for final gravimetric analysis and laboratory analysis for lead, cadmium, and arsenic. The average concentration of the constituents over the monitoring period will be calculated by dividing the mass values for TSP, lead, cadmium, and arsenic by the volume of air sampled. TSP concentrations will be compared to the PMjo and PM2.s standards to demonstrate compliance, even though the TSP concentration would overestimate and PMj.5 concentrations because it includes all airborne particulates.

Meteorological conditions are routinely recorded and reported from a NOAA weather station at the Lake County Airport. These data will be considered representative of the site and work areas within the site. A windsock will also be posted in the work area to indicate the local wind direction.

2.2 Sampling Real-time TSP Concentrations

Two MiniRAM samplers will be used to measure levels of dust generated by remediation activities to determine the immediate effectiveness of dust control measures. The MFG Field Project Supervisor (FPS) will act as Asarco's on-site representative and will be responsible for operating the MiniRAM units and documenting monitoring activities. The units will be calibrated, zeroed, operated, and maintained in accordance with the manufacturer's specifications. The procedure used for the placement and operation of the MiniRAM samplers is summarized below and detailed in the Standard Operating Procedure (SOP) entitled Real-Time Dust Monitoring (see Attachment A).

Location

Two MiniRAM samplers will be placed within or on the boundary of the work area downwind of the area of source material disturbance. The FPS will reference a windsock posted in the work area to determine the local wind direction and then locate the samplers accordingly, with a preference for locating one sampler between

ASARCO Incorporated MFG, Inc. J:\BLDOI\5J44\SJ44-50\DiniConirolPtin\Dmp.doc 3 Jufy 2004 the AV Smelter work area and Stringtown, and the other sampler between the CZL Mill work area and Stringtown. The MiniRAM samplers may be periodically relocated so as to remain generally downwind of construction activities. The time and location of placement will be noted on the appropriate Monitoring Form (see Attachment A). The MiniRAM units will be removed at the conclusion of each workday.

Procedure

The MiniRAM samplers will be operated every workday when remediation activities disturb source material in the work area; real-time monitoring will not be performed on days when there is no source material disturbance.

At the beginning of each workday, each MiniRAM will be zeroed according to the manufacturer's instructions. After zeroing, the MiniRAM will be placed downwind of dust generating activities and the time, location, and wind direction will be noted on the Monitoring Form (Attachment A). The units will be programmed to store one-hour average concentrations. Four times a day, the FPS will interrogate the MiniRAM and note the previous hourly averages on the Monitoring Form. Any time a unit is interrogated, the representative will note the time checked, the location, and the wind direction for reporting purposes.

Quality Assurance and Quality Control

Each MiniRAM is gravimetrically calibrated (NIST-traceable) in mg/m3 using standard SAE fine (ISO Fine) test dust. The internal software has an automatic calibration check referenced to the optical background that is set at the factory. This optical background is near the wavelength of natural soil. Therefore, it may or may not be representative of source materials at the AV/CZL site. However, at the beginning of the remediation activities, a gravimetric field calibration will be performed by placing the MiniRAM next to the MINIVOL and comparing the TSP concentration results. If a significant difference exists, the MiniRAM's calibration constant will be changed accordingly.

At the beginning of each day, the unit will be zeroed according to the procedure described in the MiniRAM instruction manual. Zeroing with particle free air is accomplished quickly and effectively under field conditions using the zeroing kit included.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5J44\5344-50\Dusi Control Plu\Dmp.doc 4 July 2004 2.3 Sampling for TSP and Metals Concentrations

Two portable MTNIVOL samplers will be used to evaluate TSP, arsenic, cadmium, and lead concentrations at the boundaries of the site. Boundary sampling will be used to evaluate compliance with the lead CAAQS and the TSP/PMio NAAQS and to provide information about arsenic and cadmium concentrations. The MTNTVOL samplers will be calibrated, operated, and maintained in accordance with the manufacturer's specifications and the SOP entitled Portable Dust Monitoring (see Attachment B).

Location

The MINIVOL samplers will be located between the work areas and the surrounding populated areas to the southeast of the AV/CZL Site. The FPS will determine the location of the MINIVOL samplers the night before remedial activities begin at a location. In order to represent exposure, samples will be collected within or on the boundary of the work area. The locations may be dependent on the prevailing wind direction and location of remedial activities. The FPS uses the prevailing wind direction data from the windsock, local weather forecasts, and site experience to select the sampling locations. Typically, one MINTVOL will be located between the AV Smelter work area and Stringtown and the other will be located between the CZL Mill site and Stringtown.

The unit will be placed on tripod/mast assemblies and elevated to approximately 2 meters above the ground surface. The intake will be positioned at least 30 centimeters from any airflow obstacle. The sampler will then be secured to the ground using stakes.

Procedure

The MINIVOL samplers will be operated every third workday when remediation activities disturb source materials in the work area. Twenty-four-hour samples will be collected commencing the midnight before on- site activities with shutoff 24 hours later.

Gravimetric analysis of the MINTVOL filters for mass concentration will follow EPA guidance for TSP and lead (for example, 40 CFR Part 50, Appendix G). Teflon or other filter media with extremely low metal impurities will be conditioned in a controlled environment then pre-weighed by the analytical laboratory on a balance sensitive to 10 ug. Immediately prior to use, each filter will be placed in the filter holder assembly and

ASARCO Incorporated MFG. Inc. J:\BLDOI\3344\3344-50M5uJlComrolPUn\Dmp.doc 5 Jllty 2004 attached to the sampler. A recharged battery will then be installed and the timer will be programmed for 24- hour operation. The filter assembly will be collected the next workday following the end of the 24-hour sampling period. Each filter will be inserted and removed from the filter assembly in a sheltered location to prevent potential sample loss from wind or other activity. The filter will be stored in a safe location pending submittal to the laboratory for analysis.

If TSP concentrations are measured above 150 |ig/m3, more stringent engineering controls and work practices will be implemented (as appropriate to site conditions), and the frequency of TSP monitoring will be increased to every other day of source material disturbing activities for a period of one month. During the extended monitoring period, TSP monitoring may be increased by utilizing additional MINTVOL air samplers. Additional samplers may be placed either downwind or upwind of the work area, depending on the initial (periodic) monitoring results and based on observations made during site activities. At the end of this one- month monitoring period, the monitoring data will be reviewed; if the TSP concentrations did not exceed 150 jig/m3, periodic (i.e., every third day) monitoring will be resumed.

Quality Assurance and Quality Control

To assure the sampler has an ambient flow rate of 5 liters per minute and that there is consistent performance of the TSP inlet, a new, corrected indicated flow rate will be established. The procedure accounts for the differing air temperatures and atmospheric pressures due to elevation and seasonal changes. Before the start of the remedial activities, and at 3-month intervals thereafter, each MINIVOL will have a six-point calibration to calculate the flow rate based on the ambient conditions. A single-point calibration will be made on a monthly basis. Additionally, at 3-month intervals, an audit of the actual flow rates of the sampler will be performed and compared to the calibration flow rates. The six-point calibration will be performed in a manner consistent with the MJNTVOL User's Manual. Data collection for monitoring will be performed using the MINTVOL Monitoring log provided with Attachment B.

A single-point flow rate audit will be performed once every month and at the first sign of the following warning lights: low flow threshold indicator and low flow cutoff indicator. The single-point flow rate audit will be performed in a manner consistent with the User's Manual. If the actual flow rate varies by more than 7% from the audit flow rate the unit will be re-calibrated.

ASARCO Incorporated MFG. Inc. J:\BLD01\5344\5JW-50\Dujt Control Plin\Dmp.doc 6 Jufy 2004 Typical maintenance and cleaning procedures also will be performed as required in the User's Manual. These include cleaning the flow meter, checking pump valves and diaphragms, cleaning the rain hat and filter assembly, checking the tubing and fittings, and checking the battery charge.

Once a week during remedial activities, the group of filters collected during that week will be delivered to the laboratory. A chain of custody (COC) form will be included with each batch. Every twentieth sample will be accompanied by a filter blank. After conditioning and weighing, the laboratory will analyze the filters using the modified EPA reference method for lead based on ICP-mass spectrometry (ICP-MS, SW-846 Method 6020). Although the original EPA reference method calls for Graphic Furnace Atomic Absorption (GFAA) for lead, ICP-MS has a comparable detection limit, is less subject to matrix interference, and can be used for multiple metals. After the digestion, each sample extract will be analyzed for arsenic, cadmium and lead. Based on expected ICP-MS detection limits, a 5 liter per minute sample rate and a 24-hour sampling period, the method detection limits are expected to be 7 ng/m3 for lead and cadmium, and 21 ng/m3 for arsenic.

The laboratory will perform the sample analyses and follow the Quality Assurance (QA) and Quality Control (QC) measures, such as calibrating and auditing laboratory equipment, duplicate weighing, field blanks, solution spike, solution duplicate, reagent spike, laboratory control sample, data validation, and flagging, required by their Quality Assurance Plan and EPA's SW-846 Method 6020 (ICP-MS). The results of the laboratory analysis will be available no later than ten working days after delivering the filter group. AH laboratory QA measures described herein, including printouts of metal analyses from laboratory instrumentation shall be provided to CDPHE in the final data report.

The TSP and metal/metalloid sampling methods will be assessed for precision and accuracy. Precision will be evaluated by comparing the monitoring results of two co-located samplers. Once every month, two MTNIVOLs will be placed within 2 meters of each other for one sample day. The absolute difference of the co- located samples should not exceed 5 ug/m3 when the mass concentrations are below 80 u,g/m3 and a fractional bias of 7 percent for concentrations above 80 ug/rrl. Accuracy objectives are Laboratory Control Standard recovery within the range of 80% to 120% and Matrix Spike Recovery in the range of 75% to 125%.

2.4 Meteorological Monitoring

Wind velocity at the site will be measured using a hand-held anemometer to ensure that work is not conducted in wind conditions that exceed 30 mph. At the beginning of the workday and periodically throughout the day

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5344-SO\Duii Control PUn\Omp.doc 7 Jufy 2004 when data is collected from the MiniRAM (as described above), the wind speed will be measured and recorded. If wind gusts exceed 30 mph, the FPS will order work to stop. Work will resume when a 15-minute period has passed in which no wind speeds over 30 mph are measured. Any wind-related shut downs will be noted in the Monitoring Form.

The wind direction will be estimated using a wind sock placed in the work area. At the beginning of the workday and periodically throughout the day when data is collected from the MiniRAM (as described above), the wind direction will be estimated and recorded in the Monitoring Form.

No other specific meteorological monitoring is proposed for the remedial activities because there is a station at the local airport. A local meteorological station collects data at the Lake County Airport in Leadville, CO. Current weather conditions and raw data measured at the Lake County Airport weather station can be obtained from the NOAA website: http://www.wrh.noaa.gov. This station measures wind speed, wind direction, visibility, weather conditions, temperature, dew point temperature, relative humidity, and pressure. A query of the NOAA website will only show about 3 days of data for these parameters. As such, at the conclusion of each 24-hour sample taken by the MINTVOL, the FPS will access this site and save these data. An Excel spreadsheet will be constructed to import these data and average the temperature and pressure over the 24-hour sampling period. These two parameters will allow the TSP concentrations to be corrected to standard conditions.

2.5 Personal Exposure Air Monitoring

Personnel working at the site, particularly those in areas near active operations could potentially be subject to airborne contaminant levels that exceed Occupational Safety and Health Administration (OSHA) exposure limits. Personal monitoring will be conducted in accordance with the project Health and Safety Plan (Appendix H to the Remedial Design Report) to assess workers exposure to airborne dust. Personal air monitoring will typically be performed on the same days as the real-time TSP monitoring activities described above.

ASARCO Incorporated MFC, Inc. J:\BLDOlV5344\5344-50MJiui Control Plin\Omp.doc 8 Jllty 2004 3.0 FUGITIVE DUST ACTION LEVELS AND CONTROL MEASURES

This section outlines the dust control practices that will be followed during remedial activities at the site and the action levels for more aggressive dust control measures and possible cessation of activities. Controls will be implemented to minimize fugitive dust generation from excavation/grading activities. Visual observations, real-time monitoring and samples collected at the site perimeter will be used to evaluate the effectiveness of the controls. Decisions to implement more aggressive controls or to temporarily cease activities will be based on pre-defined action levels. The remainder of this section describes the criteria that will be used and provides an overview of the expected dust control practices.

3.1 Dust Control Measures

Dust control measures will be a high priority for on-site personnel. To minimize the offsite migration of airborne dust, removal actions will include aggressive dust control measures to minimize the potential for the dispersion of lead and suspended particulate matter. Dust control will be achieved primarily by watering down work areas and vehicle traffic routes. Gravel pads may also be constructed at the exit for the work areas to public roads to minimize the tracking of residuals onto the streets and to minimize dust. Mud or dirt, which may be carried out onto public roads by haul truck traffic shall be removed daily. Watering will be provided on an as-needed basis, as follows:

• During source material excavation or regrading activities; • During stockpiling and/or loading of source material for transport; • To wash down streets or vehicles (if necessary) impacted by source material handling and transportation activities (these areas may be swept if it can be accomplished without generating dust); and • To wet down truck loads to minimize visible emissions during transport.

Additional dust control measures will be implemented in response to TSP concentrations measured above the action levels specified below. Additional dust control measures will be aggressively implemented under arid or windy conditions, whenever dust plumes are observed leaving the site or as needed to address real-time TSP measurements. Dust control measures will include application of water sprays to restrict dust generation in vehicle traffic routes and work areas. Additional dust control measures that may be used are: increased frequency of water spray applications, regulation of vehicle speed, placement of additional clean gravel as a

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-50\Dml Control PI»fl\Dmp.doc 9 Jufy 2004 ground cover in high dust generation areas, application of surfactant, or other appropriate measures. Care will be taken to avoid application of excessive amounts of water that may cause unacceptable working conditions or increase the possibility of surface run-off. If additional dust control measures do not eliminate visible dust, removal activities will be temporarily suspended until additional dust control measures have been implemented, or until adverse weather conditions abate.

Dust control alternatives may be re-evaluated, on an as-needed basis, in consultation with EPA and CDPHE representatives.

3.2 Action Levels

Action levels for more aggressive dust control measures and possible cessation of activities will be based on both visual observations and data from the monitoring program. During the course of remediation activities, the FPS will alert operations personnel when visible fugitive dust is observed. Visual observations of fugitive dust plumes will trigger more aggressive controls. Should generation of visible dust plumes continue after the additional dust mitigation measures have been implemented, work generating the dust will stop until conditions abate or additional measures will be taken to reduce dust generation and airborne transport.

The FPS will check the MiniRAM sampler four times a day during remedial activities for the following: instrument status and previous hourly averages. In addition to the visual observations, these records will allow on-site personnel to employ pro-active measures to protect against a violation of the 24-hour TSP ambient air quality standard. Initial action levels for TSP as measured by the MiniRAM and for lead as measured by the MINTVOL samplers are summarized in Table 1.

A concentration of 100 u,g/m3 will be used as the initial action level for TSP measured by the MiniRAM. Any 15-minute average concentration over 100 u,g/m3 will necessitate additional dust mitigation. If levels exceed the 100 |ig/m3 action level an alarm will sound on the MiniRAM. The FPS will then implement additional dust control measures (see previous section). After additional controls are implemented, the representative will take a downwind, 15-minute, time-weighted average concentration. If this successive TSP measurement is below 100 |ig/m3 the added mitigation measures may be discontinued. If mitigation measures are unsuccessful and result in concentrations greater than 150 fig/m3 then work will stop. Work will be allowed to resume only if a downwind 15-minute average concentration is less than the 100 u,g/m3 action level.

ASARCO Incorporated MFC, Inc. J:\BLD01\5J44\5344-50\Duil Conirol PUn\Dmp.doc 10 Juty 2004 TABLE 1 PROTECTION PROGRAM ACTION LEVELS

CONDITION ACTION TSP, 15-minute average <100ug/m3 No additional dust mitigation > 100and<150ug/m3 Additional mitigation >150ng/m3 Work stoppage

Lead, current running average of samples collected during month less than 0.5 ug/m3 No additional dust mitigation greater than 0.5 ug/rrf Evaluate data and activities during the sampling period, then implement additional dust mitigation measures as warranted greater than 1 .5 ug/m3 Work stoppage until dust mitigation measures can be developed and implemented to ensure compliance with the standard

As stated above, a wind speed of 30 mph will also trigger mitigation activities. If wind gusts exceed 30 mph, the FPS will order work to stop. Work will resume when a 15-minute period has passed in which no wind speeds over 30 mph are measured. Any dust-related shut downs will be noted in the Monitoring Form.

ASARCO Incorporated MFG. Inc. J.ABLDO I \S3W\5344-50\Duii Control Plin\Dmp.doc 11 July2004 4.0 MONITORING PROGRAM REVIEW AND MODIFICATION

Upon collection of sufficient monitoring data from the remediation work areas, these data may be reviewed to evaluate the relative contributions from remediation activities and seasonal variations to the TSP levels measured during work activities. The evaluation will consider potential contributions from excavation activities, comparison of results with the MiniRAM data and medical monitoring results. If these results indicate that real-time dust monitoring could be performed less frequently while still providing sufficient data

to demonstrate compliance with the air quality standards (CAAQS for lead and NAAQS for PM|0 and PM2.5), then a request for less frequent monitoring may be made to EPA and CDPHE Air Quality Control Division. Similarly, if a representative number of samples measure low TSP concentrations (below 150 ng/m3) and/or metals concentrations well below their relevant standards, the frequency of sample collection from the MINTVOL sampler may be re-evaluated with a request for a reduction in frequency if it can be demonstrated that a lower frequency will provide sufficient data for documenting compliance. Changes in the frequency of monitoring and sampling will not be made without prior approval from EPA and CDPHE.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5M4-50\DiBiControlPtan\Dmp.doc 12 July 2004 ATTACHMENT A

STANDARD OPERATING PROCEDURE FOR REAL-TIME DUST MONITORING MFCSOP California Gulch Superfund Site AV/CZL Remedial Action Construction Date: May 2001 Page 1 of6

STANDARD OPERATING PROCEDURE FOR REAL-TIME DUST MONITORING

1.0 INTRODUCTION

/ The following section describes procedures to be followed for real-time dust monitoring during remedial action activities at the Arkansas Valley Smelter and Colorado Zinc-Lead Mill Site, Operable Unit 5 (OU5) of the California Gulch Superfund Site in Leadville, Colorado. The procedures presented herein are intended to serve as general guidelines. As more information about the characteristics of the site become available, appropriate modifications of the procedures may be made when approved in writing by the Project Manager and the LCCHP work group. Significant changes shall also be approved in writing by the Colorado Department of Public Health and Environment.

Ambient dust monitoring will be conducted under the supervision of the MFG Field Project Supervisor. The purpose of this protocol is to specify methods to be used when operating the persona] DataRAM (referred to as a MiniRAM) manufactured by MIE, Incorporated. The MiniRAM will be used to measure total suspended particulate (TSP) at boundaries of each residential property. These data will be used to measure any generation of dust from soil remediation work and to determine the immediate effectiveness of fugitive dust control measures.

J:\BLD01\5344\5344-50\Dust Control Plan\OU5 MINlRAM-SOP.doc MFG, Inc. 1 MFC SOP California Gulch Superfund Site AV/CZL Remedial Action Construction Date: May 2001 Page 2 of 6

2.0 SAMPLE COLLECTION

Placing the samplers:

The units will be placed on a tripod and elevated to approximately 2 meters during operation. The MiniRAM sampler will be placed within or on the boundary of the work area The operator will use the prevailing wind direction data from the meteorological station, local weather forecasts, neighborhood wind sock and site experience to select the downwind sampling locations. The MiniRAM will be periodically relocated so as to remain generally downwind to dust generating activities.

Frequency of sampling:

The MiniRAM sampler will be operated every workday when source materials are being disturbed.

Preparing the MiniRAM:

Remove the MiniRAM from a ziplock plastic bag. At the beginning of each workday inside an enclosed building, place the MiniRAM inside the MIE Zeroing Kit. Zero the MiniRAM according to the manufacturer's instructions. Note the date, general location, name of representative, and general activities in the MiniRAM Monitoring Form. Verify that the MiniRAM is programmed to store 1-hour average concentrations. Verify that the MiniRAM is programmed trigger an alarm when a 15-minute average TSP concentration reaches 100 jig/m3. Attach the unit onto a tripod. Place the MiniRAM downwind of dust generating activities and note the time, location, and wind direction on the MiniRAM Monitoring Form.

J:\BLD01\5344\5344-50\DustControl Plan\OU5 MINIRAM-SOP.doc MFC, Inc. MFG SOP California Gulch Superfund Site AV/CZL Remedial Action Construction Date: May 2001 Page 3 of6

Four times a day (typically mid-morning, noon, mid-afternoon, and end of day), interrogate the MiniRAM and note the time checked, location, wind direction and previous hourly averages on the MiniRAM Monitoring Form. At the conclusion, detach MiniRAM from tripod and place it inside a ziplock plastic bag. Store in a secure location.

Maintenance and Calibration:

At the beginning of the program, a gravimetric field calibration will be performed by placing the MiniRAM next to the MINTVOL and operating both instruments for one day. The TSP concentration results from the two instruments will be compared. If a significant difference exists (see Dust Control Plan), the MiniRAMs calibration constant will be changed accordingly. The field calibration will be performed in a manner consistent with the User's Manual. Recharge the nickel-metal-hydride batteries every 72 hours of use. An aerosol dust cleaner will periodically be used to blow air across ,the sensor chamber to free up any lodged wind-blown material.

J:\BLD01\5344\5344-50\Dust Control Plan\OU5 MINIRAM-SOP.doc MFG, Inc. 3 MFC SOP California Gulch Superfund Site AV/C2L Remedial Action Construction Date: May 2001 Page 4 of 6

3.0 ACTION LEVELS AND IMPLEMENTATION OF DUST CONTROL MEASURES

Action levels for more aggressive dust control measures and possible cessation of activities will be based mainly on the real-time TSP monitoring results, as shown in Table 1. Additional alterations to the dust mitigation activities will be based on the action levels for lead listed in the SOP for PORTABLE DUST MONITORING.

TABLE 1 PROTECTION PROGRAM ACTION LEVELS CONDITION ACTION TSP, 1 5-minute average (a)

<100ug/m3 No additional dust mitigation

>100and< 150ug/m3 Additional dust mitigation

>150ug/m3 Work stoppage

(a) The MiniRAM has an audible alarm that will be set to go off at a 15-minute average of 100 ng/m3. The MiniRAM alarm can only be set to real-time (instantaneous) or 15-minute averages.

If the alarm sounds on the MiniRAM, a 15-minute average concentration has exceeded 100 ug/m3, extra dust mitigation measures are required (see below) and the following additional monitoring procedures will apply:

• After additional controls are implemented, take a downwind 15-minute time-weighted average concentration. • If this successive TSP measurement is below 100 ug/m3, the added mitigation measures will cease. • If mitigation measures are unsuccessful resulting higher concentrations in excess of 150 u.g/m3 the remediation manager will order work to stop. • Work is allowed to resume only if a downwind 15-minute average concentration is below the 100 3 threshold.

J:\BLD01\5344\5344-50\Dust Control Plan\OU5 MINIRAM-SOP.doc MFG, Inc. 4 MFG SOP California Gulch Superfund Site AV/CZL Remedial Action Construction Date: May 2001 Page 5 of6

As described in the Dust Control Plan, dust control measures will include application of water sprays to restrict dust generation in vehicle traffic routes and work areas. Additional dust control measures that may be used are: increased frequency of water spray applications, regulation of vehicle speed, placement of additional clean gravel as a ground cover in high dust generation areas, application of surfactant, or other appropriate measures. Care will be taken to avoid application of excessive amounts of water that may cause unacceptable working conditions or increase the possibility of surface run-off. If additional dust control measures do not eliminate visible dust, removal activities will be temporarily suspended until additional dust control measures have been implemented, or until adverse weather conditions abate.

J:\BLD01\5344\5344-50\Dust Control Plan\OU5 MlNlRAM-SOP.doc MFG, Inc. MFG SOP California Gulch Superfund Site AV/CZL Remedial Action Construction Date: May 2001 Page 6 of 6

4.0 DOCUMENTATION

Activities relating to real-time TSP monitoring will be recorded on an MiniRAM Monitoring Form for each day of active soil remediation. Information recorded on the MiniRAM Monitoring Form will include the following for the MiniRAM:

• Date; • General location; • Remediation manager; • General activities; • An initial of the person who zeroed the MiniRAM;

Under the General Notes,

• Identify the time the MiniRAM was checked; • The location of the sampler (i.e., SW side of excavation area); and • The direction from which the wind blows.

Under the Dust Concentration notes,

• Identify the ending hour of the time weighted average concentration and; • The TSP concentration in micrograms per cubic meters (ug/m3).

All daily MiniRAM Monitoring Forms will be maintained on-site and made available to EPA's on-Site, oversight representative at his/her request. Copies of the daily logs, and all data print-outs from the monitors will be maintained on file at the construction field office.

J:\BLD01\5344\5344-50\Dust Control Plan\OU5 MINIRAM-SOP.doc MFG, Inc. MiniRAM Monitoring Form

Date: General Location: Asarco Repressintative: General Activities: Person Who Zeroed the MiniRAM (initial)?

Dust Concentration General Notes Wind Direction/ Hour TWA Time Location of Velocity Ending (ug/m3) Sampler/Notes

J:\BLD01\5344\5344-50\Dust Control Plan\MiniRAM-Monitoring-Form ATTACHMENT B

STANDARD OPERATING PROCEDURE FOR PORTABLE DUST MONITORING MFC SOP California Gulch Superfund Site AV/CZL Remedial Action Construction Date: May 2001 Page 1 of 8

STANDARD OPERATING PROCEDURE FOR PORTABLE DUST MONITORING

1.0 INTRODUCTION

The following describes procedures to be followed for ambient portable dust monitoring during remedial action activities at the Arkansas Valley Smelter and Colorado Zinc-Lead Mill Sites, Operable Unit 5 (OU5) of the California Gulch Superfund Site in Leadville, Colorado. The procedures presented herein are intended to serve as general guidelines. As more information about the characteristics of the site become available, appropriate modifications of the procedures may be made when approved in writing by the MFG Project Manager and the LCCHP work group. Significant changes shall also be approved in writing by the Colorado Department of Public Health and Environment.

Ambient dust monitoring will be conducted under the supervision of the MFG Field Project Supervisor.

The purpose of this protocol is to specify methods to be used when collecting filter samples of the ambient total suspended particulate (TSP) with the Airmetrics MINTVOL samplers. In addition to TSP, the filters will also be analyzed for arsenic, cadmium and lead. These data will be used to document compliance with standards, where applicable, help identify the source and nature of the dust, and assess potential offsite, airborne transport of arsenic, cadmium, and lead.

J:\BLDOI\5344\5344-50\Dust Control Plan\OU5 Mini vol-sop.doc MFG, Inc. MFC SOP California Gulch Superfund Site AV/CZL Remedial Action Construction Dale: May 2001 Page 2 of 8

2.0 SAMPLE COLLECTION

Placing the samplers:

The units will be placed on tripod/mast assemblies and elevated to approximately 2 meters above the ground surface during operation. The intake should be positioned at least 30 cm from an obstacle to air flow. The tripods will be secured to the ground using stakes. The MINFVOL sampler will be located at a fixed location based on the active work area in relation to the wind patterns and background sources. The remediation manager will use the prevailing wind direction data from the meteorological station, neighborhood wind sock, local weather forecasts and site experience to select the sampling locations.

Frequency of sampling:

A MINIVOL portable sampler will be placed in a location anticipated to be downwind of the dust- generating remedial or redevelopment activities. The MINIVOL sampler will be operated every third work day that source materials are being disturbed. Twenty-four hour samples will be collected commencing the night before onsite activities and continuing until the next night (midnight to midnight). Once every month, two NUNIVOLs will be placed within two meters of each other for one sample day for quality assurance purposes. If during the periodic monitoring event TSP concentrations are measured above 150 ug/m3, more stringent engineering controls and work practices will be implemented and TSP monitoring will be extended and conducted every other day of source material disturbing activities for a period of one month. During days when the second MINIVOL is not being used to collect quality assurance samples, random samples will be collected at the discretion of the MINTVOL operator. This will depend on the initial (periodic) monitoring results and on observations made during site activities. (Expected applications might include background sampling or measurements to augment the coverage of the primary MINIVOL during intensive remedial activities.)

Preparing the MINIVOL:

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The MINWOL samplers will be calibrated, operated, and maintained in accordance with the manufacturer's specifications. Upon purchasing the 47-mm Teflon filters, the filters will be sent to the laboratory for initial tare weighing. After the laboratory sends the pre-weighed filters to the Site, each filter will be put into its own individual petri slide. Each unused filter arrives with two numbered labels attached. One label is attached to the filter holder inside the sampler, while the other is attached to the petri slide. Remove the sampler from the hanging bracket. Inside a building, remove the timer and pump assembly by grasping the 6" lid, taking care not to disconnect the power cord from the battery. Do not grasp the center of the circuit board. Mount the assembly on the edge of the sampler casing using the pump mount stand. Leave battery attached. Record the hours shown on the "elapsed time totalizer" in the MINIVOL Monitoring Log. Press the Timer On/Auto/Off button to start pump. Error: If a RED LIGHT is lit (either low flow or low battery), press the Reset button to start pump.1 With the sampler held vertically, read the flowmeter (to the nearest tenth at center of ball) and record the ending flow rate. Lower assembly back into tube. Before removing the preseparator/filter holder assembly from sampler, cross-check the filter sticker number on the assembly against the filter number for that site on the worksheet. These numbers should match. If not, make a note of this, recording the actual filter number. Remove the preseparator/filter holder assembly at the quick-connect and place it in clean plastic bag for transport back to the building. Attach a new preseparator/filter holder assembly containing a new filter at the sampler quick- connect. Change the battery pack. (Do not inadvertently confuse and reuse the spent battery.) If either the "low" or "low voltage" indicator was lit, make a note that the spent battery may be defective. Check the sampler for leaks. Remove the pump and timer assembly from the sampler body, start the pump by pressing the On/Auto/Off button, and cover the inlet with palm. The ball should drop to the bottom of the flowmeter. If it does not, check/tighten all tubing, joints, and quick- connect fittings until the sampler is leak-free. If the low flow indicator was lit, check for crimps or air restrictions in the inlet or tubing. In the MINIVOL Monitoring Log, record location, sampler #, battery #, new filter #, operator, and any comments.

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With the sampler running and while holding it vertically, adjust the flow rate to the correct level. Record the beginning flow rate to the nearest tenth of liter/minute in the MINFVOL Monitoring Log. Turn the pump off by pressing the ON/AUTO/OFF button. Record the hours shown on the elapsed time totalizer in the MTNIVOL Monitoring Log. Program the programmable timer for a 24-hour period beginning at midnight and ending at midnight the following day. Lower the pump and timer assembly into the sampler body and reinsert the bale assembly bar. Return the sampler to the mounting cradle, raising it as vertically as possible.

Handling the TSP filter:

• In a sheltered location (to prevent potential sample loss from wind or other activity) unscrew the filter holder ring from the top of the exposed filter holder assembly. • Locate the petri slide with the filter number which matches the number on the side of the filter holder assembly. This is the original petri slide that the filter came on. • Unscrew the preseparator adapter from the filter holder assembly. Lift off the anti-twist ring from the base. • Using tweezers, carefully remove the exposed filter from the drain disk and place it into its original petri slide, replacing the petri slide lid when finished. (Be sure to replace the drain disk back on the filter support grid in the filter holder assembly.) • Remove the old ID tag from the filter holder assembly base and discard. (Recheck this number to be sure it matches the number on the petri slide.)

Analytical Procedures:

The laboratory will perform a gravimetric analysis of the MINIVOL filters for mass concentration. The laboratory will analyze filters for lead, cadmium and arsenic using EPA SW-846 Method 6020. The average concentration of the constituents over the monitoring period will be calculated by dividing the mass values for TSP, lead, cadmium, and arsenic by the volume of air sampled. The reported concentration will be corrected to EPA standard conditions (25°C and 760 mm Hg).

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Maintenance and Calibration:

• Before the start of the Project, and then at the beginning and end of each construction season or at 6-month intervals thereafter, each MINIVOL will have a six-point calibration to calculate the flow rate to local ambient conditions. The six-point calibration/audit will be performed in a manner consistent with the User's Manual. • The flowmeter should be cleaned or replaced if it indicates no flow, low flow, excessive flow, or erratic flow. The flowmeter should be cleaned per the instruction listed in the Operations Manual. • If the flow rate becomes irregular or it does not allow the flow rate to be adjusted accurately, the pump valves and diaphragms may need to be cleaned or replaced. • A single-point calibration will be performed once every month and at the first sign of the following warning lights: low-flow threshold indicator and low-flow cutoff indicator. The single- point calibration will be performed in a manner consistent with the User's Manual. The flow should be within plus or minus 15 percent of 5 liters per minute at current conditions. If the unit fails to operate in this range the sampler must be repaired or recalibrated. • The rain hat and preseparator/filter holder assembly should be cleaned every 2 to 4 sampling periods, or more frequently if soiling is observed. • Tubing and fittings must be routinely checked for crimps, cracks, or obstructions. Fittings should be inspected periodically for cross-threading and tightness. • Since a single AA alkaline battery powers the programmable timer, the battery should be checked periodically and replaced as necessary to prevent failure during operation. • The 30-hour battery pack used to power the pump, should be emptied after each sampling day before charging.

2.1 Sample Labeling, Handling and Chain of Custody

A Chain-of-Custody Record (COC) and will be completed for each sample lot, secured in an plastic bag, and placed into each shipping container for shipment to the laboratory with the samples. Information contained on the triplicate, carbonless COC form includes:

• Project identification; • Date and time of sampling; • Sample identification; • Sample matrix type;

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• Sample preservation methods (if any); • Number and types of sample containers; • Sample hazards (if any); • Analysis type requested; • Sample turn-around time; • Method of sh ipment; • Carrier/waybill number (if any); • Signature of sampling personnel; • Signature, name and company of person relinquishing and person receiving the samples when custody is transferred; • Date and time of sample custody transfer; and • Conditions of samples upon receipt by laboratory.

When custody changes, personnel handling the sample exchange shall sign the record along with the date, time, and company affiliation. A copy of the record will be retained by the field sampler. Signed and completed copies of the records shall be returned by the laboratory with the analytical report.

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3.0 ACTION LEVELS AND IMPLEMENTATION OF DUST CONTROL MEASURES

Action levels for more aggressive dust-control measures and possible cessation of activities will be based mainly on the real-time TSP monitoring (see Dust Control Plan and SOP for REAL-TIME DUST MONITORING). Additional alterations to the dust mitigation activities will be based on the action levels for lead (refer to Dust Control Plan and Table 1). No action levels will be in effect for cadmium and arsenic.

TABLE 1 PROTECTION PROGRAM ACTION LEVELS CONDITION ACTION Lead, current running average of samples collected during the month less than 0.5 ug/m3 No additional dust mitigation greater than 0.5 ng/m3 Evaluate data and activities during the sampling period, then implement additional dust mitigation measures as warranted greater than 1.5 ug/m3 Work stoppage until dust mitigation measures can be developed and implemented to ensure compliance with the standard

Dust control measures will be implemented aggressively under arid or windy conditions, whenever dust plumes are observed leaving the Site, or as indicated by the action levels listed in Table 1. As described in the Dust Control Plan, dust control measures will include application of water sprays to restrict dust generation in vehicle traffic routes and work areas. Additional dust control measures that may be used are: increased frequency of water spray applications, regulation of vehicle speed, placement of additional clean gravel as a ground cover in high dust generation areas, application of surfactant, or other appropriate measures. Care will be taken to avoid application of excessive amounts of water that may cause unacceptable working conditions or increase the possibility of surface run-off. If additional dust control measures do not eliminate visible dust, dust-generating activities will be temporarily suspended until additional dust control measures have been implemented, or until adverse weather conditions abate.

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4.0 DOCUMENTATION

Activities relating to portable dust sampling will be recorded on an MINIVOL Monitoring Log for each day of active soil remediation. Information recorded on the MINIVOL Monitoring Log will include the following for the MINIVOLs:

• The hours shown on the "elapsed time totalizer" after the sampling event;

The ending flow rate after the sampling event;

The location, sampler #, battery #, new filter #, operator, and any comments at the start of a new sampling event;

The beginning flow rate to the nearest tenth of liter/minute (should be adjusted to 5 1pm, if needed);

The hours shown on the elapsed time totalizer after the initial flow rate check;

Periodic checks of the rotameter throughout the sampling day, and

Any maintenance procedures.

All daily MINIVOL Monitoring Logs will be maintained on-site and made available to EPA's on-site, oversight representative at his/her request. Copies of the daily logs, and all data print-outs from the monitors will be maintained on file at the construction field office.

J:\BLD01\5344\5344-50\Dust Control Plan\OU5 Mini vol-sop.doc MFG, Inc. MINIVOL MONITORING LOG

Date: Date: Location: Location: Sampler ID: Sampler ID: Filter No. Filter No. Battery No. Battery No. Operator: Operator:

Parameters Start End Units Parameters Start End Units

Atm Pressure (mmHg) Atm Pressure (mmHg)

AmbTemp (•C) AmbTemp (°C) Clock Time Clock Time

Elap Time (hours) Elap Time (hours)

RotoFlow •• (Ipm) RotoFlow (Ipm) Comments: Comments:

Date: Date: Location: Location: Sampler ID: Sampler ID: Filter No. Filter No. Battery No. Battery No. Operator: Operator:

Parameters Start End Units Parameters Start End Units Atm Pressure (mmHg) Atm Pressure (mmHg)

AmbTemp (°C) AmbTemp (°C) Clock Time Clock Time

Elap Time (hours) Elap Time (hours) RotoFlow , (Ipm) RotoFlow (Ipm) Comments: Comments:

J:\BLD01\5344\5344-50\Dust Control Plan\Minivol-Monitoring-Form APPENDIX G

STORMWATER MANAGEMENT PLAN Stormwater Management Plan For Remedial Action Construction at The Arkansas Valley Smelter and Colorado Zinc Lead Mill Site Operable Unit 5 (OU5)

California Gulch Superfund Site Leadville, Colorado

April 2005

Prepared for:

ASARCO Incorporated 495 East 51st Avenue Denver, CO 80216-2098

Prepared by:

MFC, Inc. consulting scientists and engineers 4900 Pearl East Circle Suite 300W Boulder, CO 80301 (303)447-1823 FAX 447-1836 TABLE OF CONTENTS

1.0 INTRODUCTION....: 2 2.0 SITE DESCRIPTION ; 3 2.1 Site Drainage 4 2.2 Surface Conditions 5 ' 2.3 Potential Pollutants '. 5 2.3.1 Risk Assessments 5 2.3.2 Potential Construction Activity Sources 5 2.4 Discharge Points and Potential Receiving Waters 6 3.0 BEST MANAGEMENT PRACTICES FOR STORM WATER POLLUTION PREVENTION 7 3.1 Structural Practices 7 3.1.1 Flue Dust Handling Areas 7 3.1.2 Run-on and Runoff Control Ditches 8 3.1.3 Sediment Control Devices 8 3.2 Non-Structural Practices 9 3.3 Materials Handling and Spill Prevention 9 4.0 INSPECTIONS AND MAINTENANCE 11 4.1 Inspection Procedures and Maintenance 11 4.2 Inspection Frequency 11 4.3 Record Keeping : 11 5.0 REFERENCES !..13

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-5

This Stormwater Management Plan (SWMP) presents details of actions and activities to be taken to control the release of pollutants to surface water during remedial action construction at the Arkansas Valley Smelter/Colorado Zinc-Lead Mill site (the AV/CZL site). The purpose of the activities described in this SWMP is to fulfill the substantive requirements of the Stormwater Discharge Regulation of the Colorado Water Quality Control Act and thus.control the release of pollutants to Stormwater during construction activities through the development, implementation, and maintenance of appropriate Stormwater and erosion control best management practices (BMPs). This SWMP is an appendix to the Remedial Design Report for the AV/CZL site.

This SWMP is divided into five sections. Introductory information is presented in Section 1. Section 2 presents a description of the site, including drainage patterns and surface conditions, potential pollutants, and potential routes for pollutants to enter Stormwater. Section 3 presents BMPs for Stormwater pollution prevention. Inspection and maintenance activities are presented in Section 4. Section 5 provides a list of references.

ASARCO Incorporated MFG. Inc. J'.\BLD01\5344\5>44-5IAAV_CZLDESIGN«TORMWATER\AV<2L-SWMP.DOC 2 April 2005 2.0 SITE DESCRIPTION

The AV/CZL site comprises a portion of Operable Unit 5 (OU5) at the California Gulch Superfund Site, which is located in Lake County, Colorado, in the upper Arkansas River basin, approximately 100 miles southwest of Denver. The Superfund Site encompasses approximately 16.5 square miles and includes the City of Leadville and portions of unincorporated Lake County. The AV/CZL site is located approximately 1.5 miles southwest of Leadville near the north bank of California Gulch and U.S. Highway 24.

The climate in the California Gulch area is cool and semi-arid, characteristic of the mountainous areas of central Colorado. The City of Leadville is at an elevation of approximately 10,000 feet above mean sea level (AMSL). Severe local topographic features strongly influence local climatic variations in Lake County.

Weather conditions are recorded at the National Weather Service's Leadville airport station located two miles southwest of Leadville. Temperatures range from a record high of 86°F to a record low of-31 °F. The average monthly maximum temperature is 50°F, with the highest average monthly maximum temperature of 72°F occurring in July. The average monthly minimum temperature is 21.9°F, with the lowest average monthly minimum temperature of 5°F occurring in January. The temperature drops to less than 32°F an average of 247 days per year (Topielec et al, '1977). The average frost-free season is 79 days.

The majority of precipitation occurs as rainfall in July and August; December and January are the driest months. Summertime precipitation is usually associated with convective showers (Topielec et al., 1977). Precipitation amounts vary throughout Lake County in relation to elevation. The south-central portion of the county, at an elevation near 9,000 feet AMSL, receives approximately 10 inches of precipitation annually. At higher elevations, annual precipitation can reach 40 inches. Annual snowfall depths for mountains in the area are between 200 and 300 inches. During winter months, the depth of snow on the ground in Leadville is commonly 6 inches. The annual peak snowmelt runoff period usually occurs in May to June.

The AV Smelter operated from 1879 to 1961, processing lead ores and reprocessing slag to produce lead, silver and other metals. The CZL Mill operated from 1926 to 1938, processing ores to produce zinc, lead, gold, silver and some copper concentrates. Remedial action construction has been designed to address environmental and human health issues relating to residual smelter and mill materials remaining at the site. The majority of smelter and mill structures have been demolished although some buildings and foundations are

ASARCO Incorporated MFC, Inc. J:\BLDOI\S344\5344-50\AV_CZL DES1GN\STORMWATER\AV-CZL-SWMP.DOC 3 April 2005 still present today. The areas of the site where remediation will occur have not been developed for reuse since the smelter and mill shut down.

2.1 Site Drainage

The only significant surface water feature in the vicinity of the AV/CZL site is lower California Gulch, which is a small ephemeral mountain stream that flows west from Leadville through Stringtown, adjacent to the CZL Mill site and eventually discharges to the Arkansas River, approximately 4 miles southwest of Leadville. The gulch drains approximately 11.5 square miles and ranges in elevation from 12,250 AMSL in upper California Gulch to 9,570 feet AMSL at the confluence with the Arkansas River. The primary sources of perennial surface water flow in Lower California Gulch are discharges from the Yak Tunnel Water Treatment Plant upstream from the AV/CZL site and the Leadville Wastewater Treatment Plant downstream. In spring and early summer, runoff from snowmelt dominates flow in lower California Gulch and its tributaries. Snowmelt runoff generally occurs over a one-month period with peak flow occurring over one or two days. The lower California Gulch tributaries are ephemeral, ceasing flow soon after snowmelt runoff or storm events.

The stream channel and associated 500-year flood plain is defined as OU8. The stream is south of the AV/CZL site. It flows adjacent to the CZL Mill site, but is more distant from the AV Smelter site, being separated by the AV Slag Pile, which is part of OU3.

The results of the Surface Water RI have established that the AV/CZL site is not considered a source of contamination to local surface water bodies (Colder, 1996), indicating that significant contaminant transport via surface runoff to California Gulch is not currently occurring. At the CZL Mill site, the volume of surface water runoff produced is expected to be small due to the limited size of the catchment area. However, due to the steeply sloping topography and proximity to California Gulch, surface transport of solid materials from the area around the mill site to California Gulch is possible, especially during storm events and snowmelt runoff. Erosion of soil and tailing is evident on the hillslopes adjacent to and below the mill foundations. At the AV Smelter site, surface water transport of solids to California Gulch is less likely because of the relatively flat topography over the majority of the site, greater distance from California Gulch and recent reinforcement of the berm between California Gulch and the AV Smelter site to the north (SMI/TMI, 1995). There are no constructed or natural surface drainages from the AV Smelter site to California Gulch. Stormwater runoff appears to either pond in relatively flat areas or infiltrate into the slag pile, which is present between the smelter site and the gulch. Stormwater runoff may discharge to California Gulch from the AV Smelter site during large

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-SO\AV_CZLDESlGhASTORMWATER\AV-CZUSWMP.DOC 4 April 2005 storm events. With the exception of localized erosion from debris piles in the vicinity of the former baghouse and blast furnace areas, soil erosion does not appear to be taking place at the AV Smelter site, and there is no evidence of off-site transport of solid materials via surface water flow.

2.2 Surface Conditions ,

The AV/CZL site is sparsely vegetated with grasses, plants and shrubs. A relatively large portion of the surface materials are comprised of non-residential area soils (residual smelter materials and contaminated soils) and tailing, which will be consolidated and covered by the remedial action construction. The majority of smelter and mill structures have been demolished though some buildings and foundations are still present. Demolition debris including brick, concrete, metal, tile, and glass remain on the site. A junkyard containing scrap metal, industrial machinery, equipment, vehicles and other large items is present in the western portion of the AV Smelter site. Roads on the site are gravel surfaced.

2.3 Potential Pollutants

2 J.I Risk Assessments

Baseline human health and ecological risk assessments were performed to identify the contaminants of concern and exposure pathways at the Superfund Site. The primary contaminants of concern (COCs) at the AV/CZL site are lead and arsenic for human health risks and arsenic, cadmium, lead and zinc for ecological risks. These COCs are present in the flue dust, non-residential area soils and tailing being addressed by the remedial action construction.

2.3.2 Potential Construction Activity Sources

Construction will include the following activities: demolition of selected structures at the AV Smelter site; excavation and relocation of flue dust into a geomembrane lined repository on the AV Smelter site; excavation of tailing, non-residential area soils, and non-salvageable demolition debris and consolidation of these materials in designated areas at the AV/CZL site; covering with soil; establishment of vegetation over the excavated areas and the soil covers; and construction of surface water controls. Primary potential sources of

ASARCO Incorporated MFC, Inc. J:\BLD01\53*4\5344-5(AAV_CZLDES1GN«TORMWATERVAV^ZL-SWMP.DOC 5 April 2005 pollutants during construction include erosion and sedimentation of flue dust, tailing or non-residential area soils, and spills of fuels or other fluids from construction equipment.

2.4 Discharge Points and Potential Receiving Waters

Site drainage patterns, as described in Section 2.1, indicate that sediment or spills released at the site have the potential to drain to the California Gulch channel, particularly from the CZL Mill site. Surface runoff from the CZL Mill site often ponds in a flat area next to the Gulch, but does drain directly during larger storm events. At the AV Smelter site, no discharge points to California Gulch have been identified: surface water runoff appears to either pond in flat areas or infiltrate through the slag pile between the site and the gulch. However, it is possible that surface runoff from portions of the AV Smelter site does discharge to California Gulch during heavy precipitation events.

ASARCO Incorporated MFG. Inc. J.VBIDOI\5344\5344-50\AV_CZLDESIGN\STORMWATER\AV-CZL-SWMP.DOC 6 April 2005 3.0 BEST MANAGEMENT PRACTICES FOR STORMWATER POLLUTION PREVENTION

This section provides a narrative description of the stormwater BMPs to be implemented during remedial action construction to minimize the potential transport of pollutants to California Gulch.

I

3.1 Structural Practices

Temporary stormwater and drainage control structures will be installed prior to excavating, regrading, or otherwise disturbing flue dust, non-residential area soils or tailing to reduce or prevent pollutants from entering and being transported by stormwater.

3.1.1 Flue Dust Handling Areas

Flue dust materials will be excavated from the areas shown on Drawing C-104. Excavated materials will be relocated to the central processing area located just to the east of the area where the repository will be constructed (see Drawing C-106). Within the central processing area, the flue dust materials will be passed through a two-inch screen and placed in stockpiles and covered with tarps to prevent contact with rainfall until they are relocated to the repository. Oversize material, such as structural debris (i.e., bricks, concrete, wood rebar, etc.) will be relocated within the final soil cover area.

In order to control stormwater contact with flue dust, run on control berms will be constructed around each flue dust excavation area. Run on control berms will also be constructed upgradient of the central processing area and run off control berms will be used to direct stormwater that lands on the central processing area to a downgradient catch basin. The catch basin will be sized to contain a 100-year 24-hour storm event. Stormwater that accumulated in the catch basin will be allowed to evaporate or removed and used as a compaction aid during placement of the flue dust in the repository.

A leachate collection pipe will be installed in the sump portion of the repository to allow the removal of any stormwater that accumulates in the base of the repository prior to installation of the top liner. Should it be necessary to remove stormwater from the repository sump, the storm water will be transported to the Yak Tunnel Treatment Plant.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-5tAAV_CZL DESIOTftSTORMWATER\AV-CZl,SWMP.DOC 7 April 2005 Once all flue dust has been excavated from its existing locations (as determined by removal confirmation sampling) and screened, it will be relocated to the repository. Prior to placing flue dust in the repository, any collected stormwater will be pumped out to a convenient location nearby. Relocation of the flue dust to the repository is expected to take a week or less. The principal factor in the proposed approach of stockpiling the flue dust and then relocating it to the repository in a single effort was to prevent significant contact between the flue dust and precipitation. Therefore during relocation, stockpiles will remain covered until used, and tarps will be used to minimize the amount of precipitation that contacts the flue dust in the repository.

3.1.2 Run-on and Runoff Control Ditches

Permanent drainage ditches will be constructed as part of the remedial action construction to route surface water around or away from the cover systems. Two control ditches will be located to the north of the CZL mill site cover system and the existing foundations (see Drawing C-l 05). Water collected in these ditches will be directed to the east and west of the cover system and released into flat areas below the CZL mill site where the flow can be slowed and dispersed. These ditches will be constructed prior to relocating any of the non- residential soil or tailing to the CZL mill site consolidation area. Permanent berms and run-off control chutes will also be constructed along the tops and faces of the cover areas once the cover layer has been installed. At the AV Smelter site a ditch will be constructed around the consolidation area (see Drawing C-l 06). Run-on and runoff from the AV Smelter site cover will be collected in this ditch, and dispersed to the south. The control ditch upgradient of the consolidation are will be constructed prior to relocating non-residential soil and tailing to the consolidation area. The control ditch along the top of the consolidation area will be constructed after the cover has been installed and will serve to minimize the potential for erosion of the soil cover. Both ditches will be maintained over the long-term to protect the integrity of the soil cover.

3.1.3 Sediment Control Devices

Hay or straw bale check dams and silt fences will be installed at 200 foot intervals along the drainage ditches. Silt fences will also be installed down gradient of areas where flue dust, non-residential area soils or tailing are being excavated or graded. They will be installed along a line of equivalent grade and along toes of slopes. These sediment control devices will be established as required, based on the work areas, topography and other site conditions. Typical installations of silt fences are shown on Drawing C-501. All sediment control devices will be maintained until vegetative cover has been re-established on the disturbed areas.

ASARCO Incorporated MFC, Inc. J:\BLDOI\3344\5344-5(MV_CZL DES1GN\STORMWATER\AV-CZUSWMP.DOC 8 April 2005 3.2 Non-Structural Practices

Non-structural BMPs may be implemented during remedial action construction completion to reduce or prevent pollutants from entering stormwater. One non-structural BMP to be used will consist of proper training of personnel in the various aspects of the SWMP. All personnel will be informed of the procedures involved in implementing and maintaining BMPs at the site. Any subcontractors will also be provided a copy of the SWMP if they are performing work related to the implementation of BMPs.

On covered slopes, straw mulch will be applied to control erosion until such time that vegetation is well established. The small grain straw mulch may be applied with a tackifier or crimped into the surface as required by site conditions. Riprap or a turf reinforcement material will also be used in some permanent drainage channels as shown on Drawing C-501.

Decontamination procedures will be implemented to minimize further migration of pollutants and to prevent particulate matter from entering stormwater from equipment. Decontamination will be implemented whenever equipment that has come in contact with flue dust, non-residential area soils or tailing leaves the site. Cover soil will be placed over the consolidated non-residential area soils and/or tailing in a manner that does not require trucks traveling between the site and the borrow area to drive directly on the consolidated non- residential area soils/tailing material. Loose tailing and non-residential area soils will be removed from trucks and heavy equipment by dry brushing prior to entering public roads. Use of water will be avoided, but will be used if tailing and/or soils cannot be removed by dry brushing. Trucks and heavy equipment will be thoroughly cleaned as needed at the conclusion of use on the project. If used during remedial construction, public roads will be swept as needed. Street sweepings and accumulated soil materials will be collected and deposited on the consolidated material at the site.

33 Materials Handling and Spill Prevention

Standard procedures will be utilized in storing and handling fertilizers, fuels, or chemicals to minimize the potential for contact with stormwater and potential runoff into California Gulch. Such procedures may include berming and lining around storage tanks and containers, and the use of adequate covers to prevent collection of precipitation. Storage containers, tanks and the like will be stored away from direct traffic routes to prevent

ASARCO Incorporated MFC, Inc. J:\BLDO I\5344\5344-5(MV_CZLDESIGN\STORMWATER\AV.CZ1^SWMP.DOC 9 April 2005 accidental spills. If small quantities of chemicals (i.e. fertilizer, etc.) are stored on site, they will be stored on pallets off the ground and will be tarped as necessary. Refuse dumpsters, if used, will also be placed away from traffic patterns and drainageways and will be equipped with functional lids to prevent collection of precipitation. Adequate signage will be used for all tanks, storage containers and the like.

In the event of an accidental spill at the site, cleanup will be initiated immediately. This may involve the use of temporary containment measures such as berming and excavation for removal of the materials for transport to either the central processing area (in the case of flue dust) or to the proper storage areas (in the case of fertilizers or chemicals). Existing clean soils in the area of the spill that may be contaminated from such a spill will be removed for proper disposal and the contaminated soils will be replaced with additional clean soil and revegetated, as necessary.

t<

Transport operations for cover soil to the site will be limited to daylight hours. Spills that occur on community roads will be cleaned up immediately.

Diesel fuel, gasoline, oil, grease, hydraulic fluids, and transmission fluids are potential stormwater pollutants. Care will be taken when vehicles and equipment are fueled and maintained to avoid spilling these materials. A quantity of absorbent will be maintained on-site to assist with cleanup, as necessary. Spills that occur will be cleaned up immediately, classified as solid or hazardous waste, and disposed appropriately. Surrounding soil around a spill will also be removed and disposed appropriately.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZLDESION\STORMWATER\AV-CZL-SWMP.DOC 10 April 2005 4.0 INSPECTIONS AND MAINTENANCE

Sediment will be removed from run-on and runoff control ditches and from behind straw bale or silt fence erosion controls as needed to maintain flow and storage capacity. Silt fences and straw bales will be replaced or re-positioned as necessary during construction to provide for continued effectiveness. Equipment will be maintained to repair leaks, worn hydraulic hoses, or other potential sources of spills.

4.1 Inspection Procedures and Maintenance

Visual inspections will be conducted to verify the operation and effectiveness of the BMPs. Inspections will be conducted of the slopes of consolidated non-residential area soils for erosion potential and of the drainage ditches, culverts and sediment control devices to verify operation, capacity, and maintenance needs. Equipment will be visually inspected for leaks or maintenance needs.

4.2 Inspection Frequency

Visual inspections of drainage structures, slopes, and equipment will be conducted daily during active periods of construction. BMPs will be inspected at a minimum of every 14 days during construction and at least monthly during any winter shutdown. During construction inspections will also be performed after any precipitation event that results in erosion.

4.3 Record Keeping

Records will be maintained of inspections of drainage structures, erosion control measures and sediment control structures, and other BMPs. The information will include the date and time of the inspection, the person conducting the inspection, the weather, the condition of the BMPs, and repairs or maintenance performed.

Records will also be maintained of any spills that may occur on the site. The records will include the time, date, location, person discovering the spill, cleanup actions, and procedures instituted to prevent future spills.

ASARCO Incorporated MFG. Inc. J:\BLD01\5344\5344-50\AV_CZLDESIGN\STORMWA-reR\AV-CZL-SWMP.DOC 11 April 2005 Finally, records will be maintained of reviews and revisions to the SWMP, including the dates of review and revision, the personnel conducting the review, and a summary of revisions made, if any.

All records will be maintained by the Engineer at the construction office during active periods of construction and will be made available for review by EPA and CDPHE on request.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZLDESIGN\STORMWATER\AV-CZUSWMP.DOC 12 April 2005 5.0 REFERENCES

Colder and Associates, Inc. (Colder), 1996. Final Surface Water Remedial Investigation Report, California Gulch Superfund Site, Leadville, Colorado. Prepared for Asarco Incorporated. May.

Shepherd Miller, Inc./Terra Matrix, Inc. (SM1/TMI), 1995. Final Engineering Evaluation/Cost Analysis for Colorado Zinc Lead Tailing Area • within Lower California Gulch Operable Unit 8. July 1995.

Topielec, R., J. Coray, and T. French. 1977. Comprehensive Plan, 1977, Lake County, Colorado, Upper Arkansas Area of Council of Governments.

ASARCO Incorporated MFG. Inc. J:\BLD01\5344\5344-50\AV_CZL DES1GN\STORMWATER\AV-CZL-SWMP.DOC 13 April 2005 APPENDIX H

HEALTH AND SAFETY PLAN HEALTH AND SAFETY PLAN FOR REMEDIAL ACTION CONSTRUCTION AT THE THE ARKANSAS VALLEY SMELTER AND COLORADO ZINC LEAD MILL SITE OPERABLE UNIT 5 (OU5) CALIFORNIA GULCH SUPERFUND SITE LEADVILLE, COLORADO

July 2004

Prepared/or: ASARCO INCORPORATED 495 East 51st Avenue Denver, CO 80216-2098

Prepared by: MFC, INC. consulting scientists and engineers 4900 Pearl East Circle Suite 300W Boulder, CO 80301 (303)447-1823 FAX 447-1836 TABLE OF CONTENTS

LIST OF FIGURES iii LIST OF ATTACHMENTS iii 1.0 INTRODUCTION 1 1.1 Plan Objectives 1 1.2 Plan Revisions :....! 1.3 Site Location and Background 1 1.4 Scope of Work 2 1.5 Project Personnel 3 2.0 ASSIGNMENT OF HEALTH AND SAFETY RESPONSIBILITIES 5 2.1 MFG Project Manager 5 2.2 Field Project Supervisor/Health and Safety Coordinator 5 2.3 MFG Corporate Health and Safety Officer 6 2.4 Contractors ....6 3.0 HAZARD EVALUATION .....7 3.1 Physical Hazards 7 3.1.1 Heavy Equipment....1. 7 3.1.2 Trenching/Excavation 8 3.1.3 Noise J 8 3.1.4 Weather 9 3.1.5 Slip, Trip and Fall 10 3.1.6 Underground Utilities 10 3.1.7 Fire Prevention 10 3.2 CHEMICAL HAZARDS 11 3.2.1 Lead , 13 3.2.2 Arsenic 13 3.2.3 Asbestos 14 3.2.4 General Precautions 14 4.0 TRAINING 1 16 4.1 General Training 16 4.2 Site Information Programs 16 4.3 , Hazard Communication 17 5.0 AIR MONITORING REQUIREMENTS 18 5.1 Personal Air Monitoring 18 5.1.1 Sampling Procedures 19 6.0 PERSONAL PROTECTIVE EQUIPMENT 21 6.1 Personal Protective Equipment Program 21 6.2 Personal Protective Equipment Levels 21 6.2.1 Level D Personal Protection 22

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5J44-50\AV_CZLDeiign\AV-CZLHASP2001.doc 1 Jufy 19, 2004 6.2.2 Modified Level D Personal Protection 22 6.2.3 Level C Personal Protection 23 6.3 PPE Deviation/Modification : 23 6.4 Limitations of PPE 23 6.5 Donning of PPE 24 7.0 MEDICAL SURVEILLANCE 26 8.0 SITE CONTROL AND DECONTAMINATION '. 27 8.1 Safe Work Practices 27 8.2 Work Zones 27 8.3 Decontamination and Safety Equipment Maintenance 28 8.4 Sanitation 29 9.0 EMERGENCY RESPONSE PLAN 30 10.0 REFERENCES 32

ASARCO Incorporated MFC, Inc. J:\BLIX>I\SJ44\5344-5

Figure 1 -1. OU5 AV/CZL Site

LIST OF ATTACHMENTS

Attachment A Safety Compliance Agreements Attachment B Plan Addenda Attachment C Safety Meeting Attendance Forms Attachment D Material Safety Data Sheets Attachment E MFG Personal Protective Equipment Program E-l Levels of Protection E-2 Outline for Selecting Respiratory Protective Devices E-3 Respirator Fit Test Record E-4 Respirator Inspection Record E-5 Respirator Program Evaluation Checklist Attachment F MFG Medical Surveillance Program Attachment G Site Location Map and Emergency Route to Hospital

ASARCO Incorporated MFG, Inc. J.\B UWIU3WU3W-50UV_CZLDeiign\AV-CZLHASP200l.doc 111 July 19, 2004 1.0 INTRODUCTION

1.1 Plan Objectives

This Construction Health and Safety Plan (the plan) has been prepared to comply with the requirements of 29 CFR 1910.120 (b)(4). The purpose of the plan is to assign personnel responsibilities, prescribe mandatory operating procedures, and to establish personal protective equipment requirements for personnel involved in the various field tasks associated with remedial action construction at the Arkansas Valley Smelter and Colorado Zinc-Lead site (AV/CZL site) located within the California Gulch Superfund Site in Lake County, Colorado. A copy of this plan will be kept on-site at all times during field activities.

1.2 Plan Revisions

The procedures presented herein are intended to serve as guidelines. They are not a substitute for the sound judgment of on-site personnel. Work conditions may change as the project progresses. As appropriate, addenda to the plan will be provided by the Health and Safety Coordinator/Field Project Supervisor. Prompt notification of changing work conditions requiring possible modification of this plan is the responsibility of the Health and Safety Coordinator/Field Project Supervisor. Additional field tasks with unique hazards or risks may also require addenda to this plan. In addition, procedures and equipment specified in this plan will be reviewed and updated as new technologies and equipment are developed. In any event, no changes to this plan will be implemented without prior approval of the Project Manager (project personnel are described in Section 1.5).

Attachment B of this plan will be reserved for plan addenda. Addenda to the plan will be added to Attachment B as needed during the course of the project. The addenda will be identified by letter and will refer to the latest current revision of the plan (e.g., the first addendum to this plan will be Addendum 1 A). Each person with a copy of this plan will be provided with each addendum. The Health and Safety Coordinator will keep a list of those persons who have a copy of this plan.

13 Site Location and Background

This section contains a brief discussion of the site location and setting. A more detailed description of the site including: site setting, history, climate, geology, hydrogeology, and hydrology can be found in the Final

ASARCO Incorporated MFG. Inc. J:\BLD01\3344\S344-3AAV_CZL DnignUV-CZL HASP200l.doc 1 Jufy 19. 2004 Focused Feasibility Study, Arkansas Valley Smelter Site and Colorado Zinc-Lead Mill Site - OperableUnit 5 (OU5).

The AV/CZL site is a portion of OU5 of the California Gulch Superfund Site. The California Gulch Superfund Site is located in Lake County, Colorado, in the upper Arkansas River basin, approximately 100 miles southwest of Denver. The Superfund Site encompasses approximately 16.5 square miles and includes the city of Leadville and portions of unincorporated Lake County. The AV/CZL site is located approximately 1.5 miles southwest of Leadville on the North bank of the California Gulch and adjacent to U.S. Highway 24. A location map is presented in Figure 1-1.

The AV Smelter operated from 1879 to 1961, processing lead ores and reprocessing slag to produce lead, silver and other metals. The CZL Mill operated from 1926 to 1938, processing ores to produce zinc, lead, gold, silver and some copper concentrates. Remedial action construction has been designed to address environmental and human health issues relating to residual smelter and mill materials remaining at the site. The majority of smelter and mill structures on the AV/CZL site have been demolished although some buildings and foundations are still present today. The smelter-related materials remaining at the AV Smelter site consist primarily of demolition debris - brick, concrete, metal, tile, wood, and glass - and residual mine waste and smelter materials including slag, coke/charcoal, limestone, ore, matte, tailing and flue dust. At the CZL Mill site, the concrete foundation of the mill structures remain, and debris associated with the main mill and smaller deposits of tailing, ore, and/or waste rock, and possibly ore concentrates are also present.

1.4 Scope of Work

The Record of Decision (EPA, 2000) for the site selected the implementation of consolidation/containment (flue dust repository and soil cover) to prevent direct contact with residual mill and smelter related materials and to control or reduce the potential for release of contaminants of concern (COCs) from these materials to the environment and consequently reduce the potential for risk to human health and the environment. The primary COCs at the AV/CZL site are arsenic and lead (human health risk) and arsenic, cadmium, lead and zinc (ecological risk). Flue dust was found to have much higher leaching potential for these metals than other residual smelter-related materials.

The final remedy includes the following features: demolition of selected structures; excavation and relocation of flue dust into a geomembrane lined repository on the AV Smelter site; excavation of tailings, non-

ASARCO Incorporated MFC, Inc. J:\BLDOIUM4\5344-50\AV_CZLDnisn\AV-CZL HASPHKJI.doc 2 Juty 19, 2004 residential area soils, and non-salvageable demolition debris and consolidation of these materials in designated areas at the AV/CZL site; placement of a soil cover over the repository, and the consolidated tailings, non-residential area soils, and non-salvageable demolition debris; establishment of vegetation over the excavated areas and the soil covers; excavation and construction of surface water controls; implementation of institutional controls to manage and control land use; and long-term monitoring of surface water and groundwater. '

The soil cover over tailings, non-residential area soils, and non-salvageable demolition debris and the repository cover for flue dust will effectively minimize the potential for direct contact to these materials. Infiltration of storm water or surface water runoff through the materials will also be significantly reduced by the consolidation. The cover soil will be vegetated to reduce erosion due to surface water runoff, prevent the entrainment and transport of dust/particulates by wind, and further reduce infiltration.

1.5 Project Personnel

The provisions of this plan are mandatory for all MFG personnel assigned to the project. A copy of this plan will be made available to all MFG personnel, contractors, subcontractors and authorized visitors that may enter the site; site personnel will also complete the "Safety Compliance Agreement" in Attachment A. This plan does not apply to EPA personnel or their on-site representatives.

MFG has developed a Corporate Health and Safety Program, to comply with the requirements of 29 CFR 1910.120. The written MFG Corporate Health and Safety Program is available upon request to all MFG employees, clients, contractors and subcontractors. Relevant sections of the Corporate Health and Safety Program have been incorporated into this plan.

Administrative information concerning this plan and key personnel are listed below.

Date Prepared: July 19,2004

Project Title: AV/CZL Site - OU5

MFG Project Number 5344.51

Site Address: Leadville, Colorado

Site Phone Numbers: Yak Water Treatment Plant: (719)486-1398

ASARCO Incorporated MFG, Inc. J:\BLDOI\5J44\5344-50\AV_CZLDaijn\AV-CZLHASP200l.doe 3 Jllfy 19, 2004 ASARCO Information Office: (719)486-3538

Client Contacts: Mr. Robert Litle (303)296-5115 ASARCO, Incorporated 495 E. 51st Avenue Denver, CO 80216

EPA Remedial Program Stan Christensen (303)312-6694 Manager: U.S. Environmental Protection Agency Region 8 999 18th St. Suite 500 Denver, CO 80202

CDPHE Project Manager: Mark Rudolph Colorado Department of Public Health and Environment HMWMD-RP-D2 4300 Cherry Creek Drive South Denver, CO 80246-1530

MFG Project Manager: Daryl Longwell Work: (303)447-1823 Mobile: (303) 588-0902 MFG Corporate Health and Safety Officer: Tory Fravel (970) 266-9409

MFG Field Project Supervisor/Health & Safety Coordinator: To Be Determined Work:

Contractor: To Be Determined

Nearest Hospital: St. Vincent's Hospital (719)486-0230 W. 4th & Washington Leadville, CO

Leadville Police: 911

Leadville Fire Dept: 911

Emergency Medical Service (ambulance): 911

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZL DclignXAV-CZL HASP200I .doc July 19. 2004 2.0 ASSIGNMENT OF HEALTH AND SAFETY RESPONSIBILITIES

This section describes the roles and responsibilities of the site personnel relative to Health and Safety.

2.1 MFC Project Manager

The MFG Project Manager will be designated as the MFG personnel that coordinates all remedial action activities for the project. The Project Manager will have the responsibility to interface with the Field Project Supervisor/Health and Safety Coordinator, field personnel, the client, and any other contractors and subcontractors. These responsibilities include the following:

• Providing technical input for the pre-entry briefing and tailgate safety meetings when required; • Interfacing between respondent parties, subcontractors and MFG regarding health and safety issues which might arise; and • Providing occasional site audit(s), as appropriate, to verify adherence to the site safety requirements.

2.2 Field Project Supervisor/Health and Safety Coordinator

The Field Project Supervisor will serve as the on-site Health and Safety Coordinator. The Field Project Supervisor/Health and Safety Coordinator (FPS/HSC) will be designated as the ranking MFG personnel on site at any given time. The FPS/HSC will have the responsibility for implementation of the plan during actual field operations. The FPS/HSC will report directly to the MFG Project Manager on a daily basis to provide work progress reports. These responsibilities include the following:

• Conducting the pre-entry briefing with field personnel; • Conducting weekly tailgate safety meetings; • Informing personnel involved in the field operations of the proper procedures during emergencies; • Observing work party members for symptoms of overexposure or stress; • Immediately reporting any unusual or unsafe conditions to the Project Manager; • Verifying that all MFG employees under his leadership work in a safe manner according to MFG policies and this plan;

ASARCO Incorporated MFG, Inc. J:\BLDOI\J344\5344-50\AV_CZLDaignVW-CZLHASP200I.doc 5 Jlity 19, 2004 • Notifying the Project Manager of any significant changes in the field work program; • Provide first aid if necessary on site; • Perform site audits to verify adherence to the requirements of the HASP; and • Modifying health and safety equipment or procedures based on data gathered at the work site.

2.3 MFC Corporate Health and Safety Officer

The MFG Corporate Health and Safety Officer will provide the following functions in support of field activities:

• Review this plan and all addenda thereto; • Be available for consultation with the Health and Safety Coordinator and Project Manager; • Modify health and safety equipment or procedures based on data gathered at the site; • Provide review and critique of emergency response actions, if any, required during performance of field activities; • Assist the Project Manager in ensuring that proper health and safety equipment is available for the project; and • Approve personnel to work on the site with regard to medical examinations and health and safety training.

2.4 Contractors

The remediation contractors and MFG subcontractors shall bear the ultimate responsibility for all matters dealing with safety in the performance of their work. This responsibility includes the safety of all persons and property and any and all employees of the contractor or subcontractors that may perform work on their behalf, as well as compliance with all applicable health and safety regulations, specifically OSHA regulation 40 CFR 1910.120. This requirement will apply continuously regardless of time or place, and will in no way be altered because MFG personnel provide general directions as to the location where work should be performed and/or samples taken. The contractor, their employees and any and all employees of subcontractors that may perform work on their behalf may be required to work with potentially hazardous substances. The FPS/HSC will, to the best of his ability, inform subcontractors or their representatives of any potential fire, explosion, health, or other safety hazards that have been identified during operations. A copy of this plan shall be made available to all contractors working at the site.

ASARCO Incorporated MFG, Inc. J:\BLD01\5344\M44-30\AV_CZLDMign\AV-CZL HASP2001.doc 6 Jufy 19, 2004 3.0 HAZARD EVALUATION

3.1 Physical Hazards

Physical hazards associated with excavation, demolition, earthmoving and other construction activities pose an equal or greater potential for injury at this site than chemical exposure. As discussed in the following subsections, physical hazards can be posed by:

• Heavy Equipment; • Trenching/Excavation; • Noise; • Weather; • Slip, Trip and Fall; • Underground Utilities; and • Fire Protection.

Injuries that may result from these physical hazards can range from simple slip-trip-fall types of accidents to casualties, including fatalities due to moving and/or rotating heavy equipment or electrocution. Injuries resulting from physical hazards can be avoided through the adoption of safe work practices and employing caution when working with machinery.

All field personnel shall be conscious of their work environment and should notify the FPS/HSC or other appropriate supervisory personnel of any unsafe conditions. The FPS/HSC will ensure that all site workers are informed of any physical hazards related to the site. All field personnel should also familiarize themselves with other contractors safety procedures.

3.1.1 Heavy Equipment

Operation of heavy equipment in excavation/earthmoving or demolition activities presents potential physical hazards to personnel. Personnel protective equipment (PPE) such as steel-toed shoes, safety glasses or goggles, and hard hats should be worn whenever such equipment is present. Personnel should at all times be aware of the location and operation of heavy equipment, and take precautions to avoid getting in the way of their operation. High visibility vests may be appropriate in open areas subject to heavy equipment traffic.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\J344-J

Trenches and excavations may pose a physical hazard to site personnel. All trenching and excavation work shall comply with the requirements of 29 CFR 1926, Subpart P. Some requirements for safe trenching are:

• Whenever possible workers will not go into trenches or excavations. • Any and all excavations and/or trenches which exceed five (5) feet in depth must be sloped, shored, sheered, braced or otherwise supported. Sloping angles and or shoring/bracing requirements shall be determined after an inspection of the soils and conditions by a competent individual. The water content of the soil, the soil type, degree of compaction,' superimposed loads and vibration can effect the stability of a trench excavation. Support systems shall be planned and designed by a qualified person. • Excavations and trenches will be inspected by a competent person before workers enter them. Furthermore, daily inspections shall be made and trenches shall be reinspected after every rainstorm or other hazard increasing event. • Excavated materials (spoils) shall be stored at least two feet from the edge of the excavation, or otherwise retained, in order to prevent this material from falling into the excavation. • In locations where oxygen deficiency or hazardous gaseous conditions are possible, air in the excavation or trench shall be tested. Controls shall be established to assure acceptable atmospheric conditions. When flammable gases are present, adequate ventilation shall be provided or sources of ignition shall be eliminated. Attended emergency rescue equipment, such as breathing apparatus, a safety harness and line, basket stretcher, etc., should be easily available where adverse atmospheric conditions may exist or develop in an excavation or trench. A log of all test results shall be maintained. • When employees are required to be in trenches four feet deep or more, an adequate means of exit, such as a ladder or steps, will be provided and located no more than 25 feet from any work area.

3.13 Noise

Heavy equipment and other construction activities may produce noise levels above acceptable standards. High noise levels can contribute to hearing loss as well as interfere with communication between workers. Exposure to noise can be expected when working around equipment and machines such as heavy earthmoving equipment, drilling rigs, generators, compressors, concrete corers, jack-hammers, etc. All personnel shall wear hearing-protective devices (i.e., either ear plugs or muffs) within 25 feet of such operating equipment, or when noise levels interfere with normal speech. Hand signals will be established by on-site personnel, as appropriate, to facilitate communications while involved in high-noise activities.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5M4-50\AV_CZLDaigii\AV-CZLHASP200l.doc 8 Jufy 19, 2004 3.1.4 Weather

Adverse weather conditions are important considerations when planning and conducting site operations. Hot or cold weather can cause physical discomfort, loss of efficiency, and personal injury. Whenever ambient air temperatures are below 50°F or above 70°F the following protocols will be observed.

When air temperatures exceed 70°F, the following general practices will also be followed:

• Site workers should consume sufficient fluids to remain hydrated; • In hot weather, activities which will require the use of protective clothing or respiratory protection will be performed in the early morning or late afternoon, when practical; and • In hot weather, the number of workers required to wear protective clothing will be minimized, as practical.

Symptoms of heat stress are: cramping; pale or clammy skin; tiredness or weakness; headaches, nausea or dizziness; fainting; high body temperature; hot, red or dry skin; rapid, weak pulse; or unconsciousness. If symptoms of heat stress are noted for a worker, the worker will be evaluated by measuring the heart rate for 30 seconds. The heart rate should not exceed 110 beats per minute; if it does, the next work period will be shortened by one third. If the pulse rate is 100 beats per minute at the beginning of the next rest period, the following work cycle should be shortened by one third.

When air temperatures are below 50°F, cold stress will be monitored for all workers. The most important factor in the prevention of cold stress is the wearing of adequate clothing. The FPS/HSC will ensure that all workers wear adequate clothing. In addition, when working in cold temperatures, the following procedures will be observed:

• Frequent breaks or rest periods will be provided and workers will have a shelter from wind and moisture; • Hot drinks may be provided in some cases; and • Opportunities to change wet clothing or to don additional clothing will be provided.

Workers will self monitor themselves and their co-workers for signs of cold stress. Symptoms of cold stress are: shivering; numbness; low body temperature; drowsiness; and weakness.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5J«yj44-5(RAV_CZL DeiigiAAV-CZL HASP200l.doc 9 July 19, 2004 3.1.5 Slip, Trip and Fall

Protection from slip, trip and fall hazards will be provided through standard safety procedures including good housekeeping. Removing equipment and debris, and taking general precautions during site operations will be standard operating procedures. Workers will be apprised of any potential trip hazards through regularly scheduled health and safety meetings. Whenever possible, trip and fall hazards will be eliminated or clearly identified with yellow "caution" tape. Impalement hazards to workers will be neutralized as soon as they are identified. Contractors are responsible for the use of safety belts, lifelines, lanyards, safety nets, etc., for safeguarding their employees or subcontractors when performing elevated work in compliance with 29 CFR 1926.

3.1.6 Underground Utilities

Before excavation activities begin, all utilities (i.e., electricity, natural gas lines, water lines, sewer lines, etc.) should be identified and deactivated as needed. If possible, any natural gas lines should be purged to remove all potentially explosive gas. The deactivation of utilities, when necessary, should be certified by the proper utility company personnel and the certification record retained.

3.1.7 Fire Prevention

Fire extinguishers shall be provided in fuel areas, and fire barrels or extinguishers will be provided as required in storage and building area. All extinguishers will be inspected serviced, and maintained. Inspections shall be recorded on the inspection tag attached to each extinguisher. Fire extinguishers and fire buckets shall be painted red and clearly marked "For Fire Only". Barrels will be kept filled at all times and the water will not be used for construction purposes. Antifreeze protection will be provided when necessary. The number, type, and location of fire extinguishers are outlined below:

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\J}44.5

Location Type Number

All vehicles 10-B one each

Field office 2-A one each

Flammable liquid storage area 20-B one per area (Outside, within 10 feet)

Where flammable liquid or gas is being used within 30 feet 10-B one each

No burning of materials will take place at the site. The use of explosives at the site is prohibited. Only approved temporary heating devices shall be used. Temporary heating devices which are the open flame-type with exposed fuel below the flame and using such fuels as coal, oil, or wood are prohibited.

All flammable liquids, including paints, will be handled and stored in a manner to conform to NFPA and OSHA requirements. The storage area will be located at a location approved by the FPS/HSC. "No Smoking Within 50 Feet" signs will be posted in and on all required storage areas and materials. Only authorized personnel will be allowed access to these areas when access is not required, they will be kept under lock and key.

3.2 CHEMICAL HAZARDS

Results from previous soil sampling performed at the site indicate that chemical, or toxic, hazards will be encountered at the site during the planned remediation activities. These hazards include heavy metals, in particular lead and arsenic, from mining activities formerly conducted at the site, asbestos, present in transite panels at the AV Smelter site, and other possibly unknown sources.

Chemical substances in gaseous, liquid, or solid form can enter the unprotected worker by inhalation, skin absorption, ingestion, or through a puncture wound (injection). A contaminant can cause damage at the point of contact or can act systemically in a different part of the body.

Chemical or asbestos exposure by inhalation is a concern since the lungs are extremely vulnerable to such agents. In addition, substances can pass through lung tissue into the bloodstream and on to other susceptible

ASARCO Incorporated MFG. Inc. JABLDOI\5M4\5344-«AAV_CZL DciignUV-CZL HASP200l.doc 1 1 Jllfy 19, 2004 areas of the body. Since some toxic chemicals are not detectable by human senses, their toxic effects may not produce any immediate symptoms. Respiratory protection is therefore extremely important if there is a possibility that the worksite atmosphere may contain such hazardous substances.

The skin and eyes also represent important routes of exposure. Some chemicals directly effect the skin, while others may pass through the skin into the bloodstream where they can be transported to other vulnerable organs. Skin absorption is enhanced by abrasions, cuts, heat, and moisture. The eye is particularly vulnerable because airborne chemicals can dissolve in its moist surface and be carried to the rest of the body through capillaries located close to the surface of the eye. Protection against skin and eye contact may be provided by:

• Wearing protective equipment; • Avoiding the use of contact lenses in contaminated atmospheres since they may trap chemicals or asbestos fibers against the eye surface; • Keeping hands away from the face; and • Minimizing contact with liquid and solid chemicals.

Inadvertent ingestion can occur as a result of personal habits such as chewing gum or tobacco, drinking, eating, smoking cigarettes, and applying cosmetics. These practices may provide a route of entry for chemicals and are restricted in work areas.

On the basis of the results of previous soil sampling performed at the site airborne dust contaminated with lead and arsenic has been identified as the primary source of potential exposure at the site. Excess generation of dust is potentially possible during intrusive activities (i.e., soil excavation, handling and transportation, and soil sampling), and/or on windy days.

A variety of air concentration levels have been established by regulating and scientific agencies to protect workers from airborne hazards. The Threshold Limit Value - Time Weighted Average (TLV-TWA) values are the time-weighted average concentration for a normal 8-hour workday and a 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. TLV-TWA values are established by the American Conference of Governmental Industrial Hygienists (ACGIH, 1995) and provide the basis for safety regulations of OSHA. Threshold Limit Value - Short Term Exposure Limit (TLV-STEL) values are the concentrations to which workers can be exposed for a short period of time (15 minutes) without suffering from: (1) irritation; (2) chronic or irreversible tissue damage; or (3) narcosis of sufficient degree to

ASARCO Incorporated MFG. Inc. J:\BLD01\5344\3M4-50\AV_CZL Design\AV-CZL HASP200l.doc 12 Jufy 19, 2004 increase the likelihood of accidental injury, impair self-rescue or materially reduce work efficiency. Permissible Exposure Limits (PELs) are enforceable standards promulgated by OSHA and represent the 8-hour time-weighted average above which workers may not be exposed. The Immediately Dangerous to Life and Health (IDLH) limit (NIOSH, 1994) is defined as the maximum concentration of toxic substance from which escape is possible without irreversible harm should a worker's respiratory protective equipment fail. In addition OSHA has designed "Action Levels" for some substances (e.g., lead). OSHA Action Levels are typically lower than the OSHA PEL for a particular substance, and are levels which, when exceeded, trigger certain air monitoring and medical surveillance requirements. The values for each of these exposure limits are listed along with a description of the contaminant, and health effects resulting from exposure in the following sections.

3.2.1 Lead

Lead is a heavy, ductile, soft-gray, noncombustible metal, which is insoluble in water. Potential routes of entry into the body include inhalation, ingestion, and contact with dust/fumes. Symptoms of exposure are weakness, lassitude, insomnia, facial palter, anorexia, low-weight, malnutrition, constipation, abdominal pain, colic, anemia, gingival lead line, tremors, wrist-drop/paralysis, ankle paralysis, encephalopathy, nephropathy, eye irritation, and hypotension. Target organs include the GI tract, central nervous system, kidneys, blood, and gingival tissue.

The worker protection levels for airborne lead are as follows: • TLV-TWA 0.15mg/m3 • TLV-STEL NA • PEL 0.05 mg/m3 • IDLH Limit 100 mg/m3 • OSHA Action Level 0.030 mg/m3

3.2.2 Arsenic

Arsenic is a silver-gray or tin-white, brittle, odorless metal, which is insoluble in water. It is a noncombustible solid in bulk form, but may be a slight explosion hazard in the form of dust when exposed to flame. Inorganic arsenic can react with hydrogen gas to form the highly toxic gas arsine. Potential

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5M4-50\AV_CZLDelignUV-CZLHASP2001.doc 13 Jufy 19, 2004 routes of entry include inhalation, skin absorption, skin and/or eye contact, and ingestion. Symptoms of exposure are ulceration of the nasal septum, dermatitis, GI disturbances, peripheral neuropathy, respiratory irritation, and hyperpigmentation of the skin. Arsenic is a potential occupational carcinogen. Target organs from exposure include the liver, kidneys, skin, lungs, and the lymphatic system.

The worker protection levels for airborne arsenic are as follows: • TLV-TWA 0.010mg/m3 • TLV-STEL 0.002 mg/m3 • PEL 0.010 mg/m3 • IDLH Limit 5.0 mg/m3 • OSHA Action Level 0.005 mg/m3

3.23 Asbestos

Asbestos is a white or greenish-blue-grey fibrous, odorless solid. It is present at the site in the transite panels at the AV Smelter blast furnace structures. It is an insoluble, non-combustible solid. Potential routes of entry include inhalation, ingestion and skin/eye contact. Symptoms of exposure are asbestosis (after chronic exposure), interstitial fibers, restricted pulmonary function, and irritated eyes. Asbestos is a suspected occupational carcinogen and NIOSH recommends that exposure be reduced to the lowest possible concentration.

The worker protection levels for airborne asbestos are as follows: • TLV-TWA 0.1 fibers/cm3 • TLV-STEL , 1.0 fibers/cm3 • PEL 0.1 fibers/cm3 • IDLH Limit not available • The OSHA Action Level 1.0 fibers/cm3

3.2.4 General Precautions

If signs of contamination different from those addressed in this plan are encountered, such as visible soil stains or unusual odors, stop all work in the area, barricade or otherwise isolate the area, and immediately

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5344-50\AV.CZLDeiign\AV-CZLHASP200l.doc 14 Jltfy 19, 2004 contact the FPS/HSC. Protection of worker health and safety shall be the first priority. Continuation of work in the area and the amount of, if any, personal protective equipment shall be determined by the FPS/HSC. Other precautions to be undertaken to ensure a safe work place on this project where the potential for chemical exposure may exist include:

• No smoking, eating, or drinking in areas where contaminants may be present; • Avoid the area immediately downwind of any excavation; • Contact with contaminated materials should be minimized through the knowledge of site conditions and the location of potential contamination based on previous site investigation reports; • Minimize the creation of dust, through dust suppression such as water application; and • Adequately barricade all work zones to ensure public safety.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5J44\5344-SO\AV_CZLDeiign\AV-CZLHASP200l.doc 15 Jltfyl9,2004 4.0 TRAINING

4.1 General Training

Prior to initiation of field activities, all field personnel shall have completed an initial 40 hour Hazardous Materials Health and Safety Course and 8-hour annual refresher course(s), as appropriate. All field personnel shall also have a minimum of three days of actual field experience under the direct supervision of a trained, experienced supervisor. The FPS/HSC shall have completed at least eight additional hours of specialized supervisor training as per 29 CFR 1910.120 (e)(4). All courses shall have been conducted, by a qualified trainer as specified in 29 CFR 1910.120 (e)(5). These courses cover chemical hazards, hazard recognition, hazard assessment and personal protective equipment. The FPS/HSC will have been trained in standard first aid measures and cardiopulmonary resuscitation (CPR)

All personnel who may participate in the site remediation field activities shall be required to have completed appropriate training as specified in 29 CFR 1910.120 (e)(3) prior to the initiation of site activities. The supervisor training requirement will also apply to the contractor/subcontractor supervisors. The contractor/subcontractor shall provide MFG with copies of written certificates documenting said training. Copiesof training certificates for on-site personnel will be kept at the site in the possession of the FPS/HSC during the performance of field activities.

4.2 Site Information Programs

Prior to the initiation of each phase of fieldwork, all personnel who will participate in the site remediation construction work shall attend a pre-entry briefing. Information contained in this plan, including: (1) names of personnel responsible for site safety and health; (2) safety, health and other physical and chemical hazards present on the site; (3) use of personal protective equipment; (4) work practices by which the employee can minimize risks from hazards; (5) safe use of engineering controls and equipment on the site; (6) medical surveillance requirement, including recognition of symptoms and signs which might indicate overexposure to hazards; (7) frequency and types of air monitoring, personal monitoring and environmental sampling techniques and instrumentation to be used; (8) site control measures; (9) site decontamination procedures; (10) emergency response procedures; and (11) spill containment procedures will be reviewed in detail at the pre-entry briefing. In addition, all persons participating in field activities shall be required to read this plan and sign a safety compliance agreement (Attachment A). Information discussed at the pre-entry briefing will

ASARCO Incorporated . MFG, Inc. J:\BLDOI\5344V5344-50\AV_C2LDoign\AV-CZLHASP200l.doc 16 Jufy 19, 2004 be reinforced, in turn, during tailgate safety meetings (see below). Additional pre-entry briefings may be required for additional phases of work or if new personnel are assigned to the project.

Tailgate safety meetings will be conducted weekly, or whenever new personnel arrive and/or when a unique work assignment warrants employee training. Tailgate safety meetings will be conducted by the FPS/HSC. These meetings will cover the projected work for the week or specific task and will review and reinforce good safety practices (e.g., proper protective clothing, effective deterrents of heat stress, etc). Information discussed at the tailgate safety meetings may be revised and updated, based on any new data obtained pertain ing to site characterization and analyses.

An attendance record will be kept for the pre-entry briefing and for all subsequent tailgate safety meetings. In addition to documenting the persons in attendance, these records will include the date and time of the meetings and the subjects covered. A sample safety meeting attendance form is included in Attachment C.

43 Hazard Communication

MFG will inform its employees and subcontractors of potential hazards associated with chemicals brought to the site to perform various field activities. The information will be distributed in the form of Material Safety Data Sheets (MSDSs). Copies of the MSDS for each chemical brought to the site will remain onsite during the period that the chemical is being utilized. Safe handling practices and emergency first aid for each chemical will be discussed during the pre-entry briefing, tailgate safety meetings, etc. MSDS for arsenic, lead and asbestos are included in Attachment D.

The Health and Safety Plan of the remediation contractor shall also be available on-site. The remediation contractors Health and Safety Plan will cover hazard communication concerning the chemicals utilized by the contractor.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5J44\SJ44-50\AV_CZLD«isn\AV-CZLHASP200l.doc 17 July 19, 2004 5.0 AIR MONITORING REQUIREMENTS

Air monitoring will be performed on-site to comply with the Clean Air Act and related State of Colorado regulations and to minimize the potential for work personnel and the public being exposed to airborne lead, arsenic, or asbestos. The Fugitive Emissions Dust Control Plan for remediation activities is presented in Appendix F of the Remedial Design Report. The purpose of the Fugitive Emissions Dust Control Plan is to document the basis for ambient air quality monitoring; explain the planned methodology for air quality monitoring; and describe the procedures for evaluating and reporting air monitoring data. Personal air monitoring will be conducted at the initiation of removal action activities to evaluate potential worker exposure. The frequency and method of air monitoring are discussed below. Personal air monitoring results will be recorded and a written record of the results will be maintained in the project files.

5.1 Personal Air Monitoring

Personal air monitoring will be conducted for all activities in which personnel are potentially exposed to airborne dusts that may contain lead, arsenic, or asbestos. There are minor amounts of asbestos at the site and remediation work for asbestos is expected to be of very short duration. This work will be performed by specialized workers wearing respirators.

Typically, one worker per crew per day (during excavation activities) will be monitored. Personnel who have the greatest potential exposure expected during the monitoring period will be targeted. The frequency of sampling may be reduced if sampling results indicate that exposures to lead or arsenic are at a diminutive level. The reduction in sampling frequency must have the prior approval of the FPS/HSC and the Project Manager.

Personnel will be monitored for a full shift, at least 8 continuous hours of the work day. Full-shift personnel samples will be representative of the monitored employee's regular, daily exposure to lead or arsenic. The sampling program will be evaluated after reviewing results from the first three days of monitoring. At that time, a recommendation will be made, based on the observed results, to continue with the present air- monitoring program or modify the personal air-sampling program.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5J44\3J44-50\AV_CZLDcsign\AV-CZL HASPJOOI.doc 18 Jllty 19, 2004 5.1.1 Sampling Procedures

Calibration of the personal air sampling filter cassettes (0.8 [an Mixed Cellulose Ester Filters 37 mm) will be performed in line with the sampling pump. The flow rates will be set at approximately 2 liters per minute. Total dust samples [total suspended particulates (TSP)] will be collected on pre-weighed 5 urn PVC 37 mm filter cassettes. The filters will be attached to the primary calibrator and three calibration runs (1.5 to 2 liters per minute flow rate) will be made and averaged for an initial (pre) calibration. The pre-calibration information will then be written on the sampling data sheet. The filters will be checked to see if they lay flat against the backup pad. If the filters are not flat or contain a deformity then the filters will be discarded.

The sampling pumps will be attached to an employee's belt with the Tygon tubing stretching behind their back so that the filter cassette hangs face down from the individual's collar or within the breathing zone. One hour after the sampling pump is attached to the individual, the flow will be checked to see if it is maintained to within 10 percent of the original flow. If the flow is not within 10 percent, the pump will be replaced or the flow rate adjusted to within 10 percent of the original setting. Calibration checks will continue periodically throughout the day.

The sampling pumps should remain on throughout the entire work day. The individual's exposure should be monitored continuously throughout the day as long as the individual remains on the site. If the individual should be required to leave the work site the pump should be shut off and the duration of the pump down time documented. A record of the individual's activities during the day should be noted on the sampling data sheet. The filters should be checked according to manufacture's recommendations.

At the end of the day, the sampling pumps will be shut off and the total sampling time recorded on the sampling data sheet. The pumps will go through post-calibration with a primary calibrator. Again, three runs will be made and averaged for a final post-calibration, which will be recorded on the sampling data sheet. The day's temperature and atmospheric pressure should be recorded on the sampling data sheet, with a standard temperature and pressure correction factor used when necessary to determine the correct volume collected.

Sampling and analytical methods will follow the National Institute for Occupational Safety and Health (NIOSH) methods for lead and total dust (TSP). A blank quality assurance (QA) sample for each analyte sampled will be sent for each ten samples delivered to the laboratory. Timely analyses of results are necessary so that monitoring data may be used to insure that the proper levels of protection are being utilized.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\5J44-SO\A V_CZLDaign\AV-CZLHASP200l.doc 19 . July]9,2004 Every effort will be made to obtain rapid analysis of the samples so that the data can be used to upgrade or downgrade the levels of PPE. The cassettes will be sent for analysis with a turn-around-time of 48 hours. Employees will be notified of the results of their air monitoring samples within 5 working days following the receipt of the laboratory results.

ASARCO Incorporated MFC, Inc. J:«LDOI\5M4\5J44.50UV_CZLDelisiM V-CZLHASP200l.doc 20 Jltfy ]9, 2004 6.0 PERSONAL PROTECTIVE EQUIPMENT

6.1 Personal Protective Equipment Program

MFG has developed and implemented a personal protective equipment (PPE) program to comply with the requirements of 29 CFR 1910.120 (g)(5). This PPE program contains procedures for: (1) PPE use and limitations; (2) PPE maintenance and storage; (3) PPE decontamination and disposal; (4) PPE training and proper fitting; (5) PPE donning and doffing; (6) PPE inspection prior to, during, and after use; (7) evaluation of the PPE program effectiveness; and (8) limitations during temperature extremes and heat stress, and other appropriate medical considerations. The PPE program also includes a respiratory protection program (RPP) that complies with 29 CFR 1910.134. The RPP contains procedures for documentation of respirator fit testing. The MFG personal protective equipment program is included herein as Attachment E. Copies of OSHA training and refresher course documentation for on-site personnel will be kept at the site during the field activities.

Subcontractors with personnel that may be required to wear respiratory protection during the site remediation field activities shall have developed and implemented a RPP, including procedures for respirator fit testing. In these cases, prior to initiation of field activities, subcontractors shall provide MFG with respirator fit test documentation for personnel who may participate in the site remediation. Copies of fit test documentation for on-site personnel will be kept at the site during the performance of field activities.

In designing the level of PPE for the site remediation, the degree of risk for the four basic routes of exposure (inhalation, skin absorption, ingestion, and eye or skin contact) to potentially hazardous substances was evaluated. Action levels have been developed for this project to provide a safe level of exposure in which project workers may perform their duties. When the established action levels are exceeded, certain procedures will be taken to reduce potential exposure. Engineering controls are to be implemented first whenever possible. When engineering controls are not possible or prove to be insufficient, PPE will be used to limit potential exposure.

6.2 Personal Protective Equipment Levels

The following sections describe the levels of personal protection for field work at the site. These levels are based upon previous field work performed at the site and the physical and chemical hazards at the site

ASARCO Incorporated MFG, Inc. J:\BLDOI\5J44\5344-SO\AV_CZL DcsigiAAV-CZL HASP200l.doc 21 Jufy 19, 2004 (Section 3.0). All site activities are anticipated to be performed in Level D protection. Work associated with flue dust will be performed in Level C protection until personal monitoring data demonstrates that a lower level of protection is adequate. Upgrading or downgrading of PPE will be based on air monitoring results as discussed in Section 5.1.

6.2.1 Level D Personal Protection

The level of personal protection worn by field personnel will be defined, controlled, and implemented by the FPS/HSC. Protection may be upgraded or downgraded by the FPS/HSC, on the basis of action levels presented above. Level D personal protective equipment includes the following:

• Work gloves (disposable nitrile or cotton, depending on task); • Steel-toe work boots (conforming to ANSI Standard Z 41.1); • Hard hats (conforming to ANSI Standard Z 89.1); • Eye protection (conforming to ANSI Standard Z 87.1); and • Hearing protection (when excessive noise is present).

6.2.2 Modified Level D Personal Protection

Modified Level D personal protective equipment includes the following:

• Disposable Tyvek* coveralls (exchanged when heavily soiled or after breaks, at least once per work day); • Work gloves (disposable nitrile or cotton, depending on task); • Steel-toe work boots (conforming to ANSI Standard Z 41.1); • Hard hats (conforming to ANSI Standard Z 89.1); • Eye protection (conforming to ANSI Standard Z 87.1); and • Hearing protection (when excessive noise is present).

ASARCO Incorporated MFC, Inc. J:\BLDO l\J344\»44.SO\AV_CZLD«ign\AV.CZLHASP200l.doc 22 Jufy 19, 2004 6.2.3 Level C Personal Protection

• Disposable Tyvek® coveralls (exchanged when heavily soiled or after breaks, at least once per work day); • Work gloves (disposable nitrile or cotton, depending on task); • Steel-toe work boots (conforming to ANSI Standard 2,41.1); • Hard hats (conforming to ANSI Standard Z 89.1); • Eye protection (conforming to ANSI Standard Z 87.1); • Hearing protection (when excessive noise is present); and • Full-face or half-face respirator with high efficiency paniculate (HEPA) cartridge filter.

Inner gloves are optional for any of the above PPE levels. Inner gloves are typically thin, latex, nitrile or polyethylene gloves.

63 PPE Deviation/Modification

Protection levels may be upgraded, downgraded, or modified as deemed necessary by the FSP / HSC based upon work task or site-specific^' safety-related factors such as:

• When excessive noise levels exceed 85 dba, hearing protection is required; • Change is work tasks within a work area/exclusion zone, or work that begins on a different portion of the site; • Change of season/weather; • When temperature extremes or individual medical considerations (i.e., heat stress, medication, etc.) limit the effectiveness of PPE; • Contaminants other than those previously identified are encountered; • Change in ambient levels of contaminants; and • Change in work space which effects the degree of contact with contaminants.

6.4 Limitations of PPE

PPE ensembles designated for use during work tasks have been selected to provide protection against contaminants at known or anticipated concentrations in soil or water. However, no protective garment, glove, or boot is chemical-proof, nor will it afford protection against all chemical types. Permeation of a given

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL DeigtAAV-CZL HASP200l.doc 23 July 19, 2004 chemical through PPE is a complex process governed by contaminant concentrations environmental conditions, physical condition of the protective garment, and the resistance of a garment to a specific contaminant; chemical permeation may continue even if a garment is resistant to a specific contaminant; chemical permeation may continue even after the source of contamination has been removed from the garment.

In order to obtain optimum usage from PPE, the following procedures are to be followed by all site personnel using PPE:

• When using disposable coveralls, don a clean, new garment after each rest break or at the beginning of each shift. • Inspect all clothing, gloves, and boots both prior to and during use for: • Imperfect seams' • Non-uniform coatings • Tears • Poorly functioning closure • Inspect reusable garments, boots; and gloves both prior to and during use for: Visible signs of chemical permeation Swelling Discoloration Stiffness B littleness Cracks Any sign of puncture Any sign of abrasion

Reusable gloves, boots, or coveralls exhibiting any of the characteristics listed above will be discarded.

6.5 Donning of PPE

A routine will be established and followed at the site for donning the PPE. The procedures will be discussed in detail during the site safety meeting before starting the project and briefly during the periodic site safety meetings.

Before wearing any level of PPE, it will be checked to ensure that it is in proper condition for the purpose for which it is intended. Also, workers with any minor injuries and/or openings in the skin surface, such as cuts

ASARCO Incorporated MFG. Inc. J:\BLDOI\5J44\5J44-50\AV_CZL Deiign\AV-CZLHASP200l.doc 24 Jllfy 19, 2004 and scratches, will be attended to in order to protect such areas which may potentially enhance exposure effects. Workers with large cuts, rashes, or other such skin damage will not be allowed to don PPE.

After wearing the equipment, its fit will be evaluated by the FPS/HSC before the worker is allowed to enter the Exclusion Zone (see section 8.2 for definition).

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\53«-5

MFG has developed and implemented a medical surveillance program to comply with the requirements of 29 CFR 1910.120 (f). This program requires annual medical monitoring (including pulmonary function evaluation) for all MFG field personnel. Records for this program are kept in compliance with the requirements of 29 CFR 1910.120. These records include: (1) the name and social security number of the employee; (2) physician's written opinions, recommended limitations, and results of examinations and tests; (3) any employee medical complaints related to exposure to hazardous substances; and (4) a copy of the information provided to the examining physician by the employer. The MFG Medical Surveillance Program is reproduced in Attachment F. Contractors/subcontractors will be required to have medical surveillance programs that comply with 1910.120 (f)-

Due to the possible hazards presented at the site (Section 3.0), additional medical monitoring including blood lead and zinc protoporphyrin (ZPP) and urine arsenic analyses will be performed for all MFG field personnel prior to initiation of field investigation activities. Blood lead and ZPP and urine arsenic analyses will be repeated upon completion of field investigation activities, and/or within six months, whichever comes first. Results of this site-specific testing will be kept as described above. Similar site-specific monitoring will be required for contractor/subcontractor personnel involved in intrusive investigation activities.

ASARCO Incorporated MFG, Inc. J:\BLDOI\i344\S344-5(AAV_CZLDeiign\AV.CZLHASP2001.d« 26 ' Jufy 19, 2004 8.0 SITE CONTROL AND DECONTAMINATION

The site control and decontamination program is designed to accomplish two objectives. The first objective is to minimize the exposure of personnel to potentially hazardous substances and/or situations. The second objective is to minimize the transfer of potentially hazardous substances within and from the site. These objectives will be accomplished by the use of a buddy system, the establishment of work zones, the proper decontamination of personnel and equipment, and proper maintenance of safety equipment.

8.1 Safe Work Practices

The following general safe work practices will apply for each task involving field work at the site:

• A "buddy system" will be used for all field activities with buddies assigned prior to the initiation of each task. Each worker will be responsible for monitoring the location and condition of his buddy at all times while in the exclusion and contaminant reduction zones (see below) and will assist his buddy in PPE decontamination as needed. • Personnel will not eat, chew gum or tobacco, smoke, take medicine or perform any other practice that increases the likelihood of hand to mouth transfer of potentially hazardous substances from gloves, unwashed hands or equipment when in the exclusion or contaminant reduction zones (see below). • No one is to carry "strike-anywhere" matches or cigar/cigarette lighters. • Personnel will stand upwind of all intrusive activities involving disturbance of the ground surface (e.g., soil excavation). • Breaks will be offered to all site workers. A five-minute break per hour may be taken by any worker, although it is not mandatory. Breaks may be taken while in the exclusion zone; however no water will be available in the exclusion zone. Water may be consumed in the contaminant reduction zone.

8.2 Work Zones

For all field tasks performed during the site remediation, three zones will be defined at the site: the exclusion zone, the contaminant reduction zone and the support zone. These zones will be defined by the remediation contractor. The exclusion zone is the area where contamination does or could occur. Unauthorized personnel, unnecessary equipment or vehicles will not be permitted in the exclusion zone while work is being performed. Access to the exclusion zone will be controlled by the FPS/HSC. The contaminant reduction zone (CRZ) is the transition area between the potentially contaminated area and the support zone.

ASARCO Incorporated MFC, Inc. J:\BLD01\5344\5344-S(AAV_CZLD««igli\AV^ZL HASP200l.doc 27 JufyI9,2004 Decontamination operations (see Section 8.3 below) will be performed in the CRZ. The support zone is considered a non-contaminated or clean area. This zone will be defined as the area outside of the exclusion zone. Normal work clothes are permitted in this zone.

8.3 Decontamination and Safety Equipment Maintenance

At the completion of fieldwork, equipment used to excavate, or handle residual smelter / mine waste materials will be decontaminated prior to leaving the site. An area at the site within the contaminant reduction zone will be used to establish a decontamination area. Water will be allowed to evaporate from the decontamination area, to the extent possible.

Decontamination and maintenance of personal protective equipment is required to ensure their proper functioning and level of protection. At a minimum, nitrile gloves and Tyvek* coveralls shall be replaced daily or after breaks; if they become damaged, they shall be replaced immediately.

Decontamination of personnel, PPE and small, hand-operated equipment will take place within the personnel decontamination area; stations in the area will be as follows:

Station 1: Remove disposable PPE such as coveralls, boot covers and gloves (if used); deposit in container (likely a 55-gallon drum with plastic liner).

Station 2: Remove hardhat, safety glasses and/or respirator (if used); rinse if necessary with hand-held sprayer; place on table or in plastic tubs to dry. Inner gloves (if used) will be removed last and placed in container with plastic liner.

Station 3: Rest/Break Area and Decontamination Area Exit

This area will be utilized as a rest or break area. First aid supplies and water will be located in this area. Shade, fluid-replacement drinks and hot drinks may be provided in hot or cold weather.

The above outline is intended as a guideline for decontamination procedures. The decontamination areas will be established prior to initiation of field activities, and the exact decontamination procedures will be established at that time based on field conditions, space considerations, etc. In addition, the above decontamination procedures apply only to activities where modified Level D or Level C PPE is required. For other activities, a less rigorous decontamination procedure may be practiced, consisting of a thorough scrubbing of boots and removal and disposal of PPE in proper containers, etc.

ASARCO Incorporated MFC, Inc. J:\BLOOI\5144\5344-50\AV.CZLDdign\AV-CZLHASP200l.doc 28 Jllty 19, 2004 Following completion of site remediation activities, decontamination equipment, Tyvek® coveralls, gloves, plastic sheeting and other disposable items will be placed in large plastic bags and disposed of per approved procedures. Water from decontamination operations will be contained on-site. No organic solvents will be used for site decontamination operations.

8.4 Sanitation

An adequate supply of potable water will be provided for all site workers in portable containers placed in the support zone. Single service cups and a receptacle for used cups will be provided adjacent to the water container. Washing facilities will be provided in the CRZ. A portable toilet may be located within the support zone.

ASARCO Incorporated MFC, Inc. J:\BLDOl\H44\5344.5

The required elements of an emergency response plan as specified in 29 CFR 1910.120(1) are listed below. As described in the regulation, many of these items primarily pertain to emergency responses at uncontrolled hazardous waste sites, and thus are not entirely applicable to the tasks of the site remediation, which do not constitute an emergency response situation. The remediation contractors will be responsible for providing emergency response plans for their activities. An explanation of how each plan element will be implemented at the site is provided below:

1) Pre-emergency planning - This emergency response plan will be provided to all personnel (including subcontractor personnel) working on the site during the pre-entry briefing. In addition, emergency response actions will be reviewed with all personnel during the pre-entry briefing and the tailgate safety meetings.

2) Personnel roles, lines of authority, and communication - The FPS/HSC will be responsible for emergency coordination at all times. Any accidents and/or injuries shall immediately be reported to him.

3) Emergency recognition and prevention - Physical and chemical hazards at the site will be reviewed at the pre-entry briefing and the tailgate safety meetings. Air monitoring will be performed to provide early warning of potential emergency conditions.

4) Safe distances and places of refuge - Should emergency conditions arise requiring site evacuation, the FPS/HSC will notify all on-site personnel immediately through the use of hand signals and an air hom. The FPS/HSC will notify all on-site personnel through the use of hand signals and an air horn in the event that operations should be immediately stopped but the site may not require evacuation.

5) Site security and control - During performance of field activities, site control will also be provided through the designation of work zones for each activity.

6) Evacuation routes and procedures - The FPS/HSC will notify all on-site personnel of the need for immediate evacuation. Site evacuation will be performed in an orderly fashion under the direction of the FPS/HSC. All field equipment, except for personal air monitoring instruments, will be left on-site. In case of a site evacuation due to airborne contaminant levels that exceed worker protection levels, personal air monitoring instruments will be used . to determine when the site is safe to reenter.

7) Emergency decontamination procedures - In the event of a medical emergency, personnel decontamination- prior to medical treatment may be omitted. Whenever possible, MFG personnel will accompany contaminated victims to the hospital to advise on matters involving decontamination. If on-site first aid is rendered and the victim does not require transport to the hospital, clothing and equipment decontamination as described in Section 8.3 will be performed after first aid measures have been performed.

ASARCO Incorporated MFC, Inc. J.\BLDOI\3J44\5J44.50\AV..CZL DesigMAV-CZLHASP200l.doc 30 Jufyl9,2004 8) Emergency medical treatment and first aid - Based on the severity of the injury/exposure, additional medical treatment will be obtained as described below.

9) Emergency alerting and response procedures - The procedures listed below will be used in the event of any site emergency:

a) Assess the situation to insure personal safety is not compromised before rendering aid to anyone.

b) If a serious injury or life-threatening conditions exists, dial 911 from the nearest phone so that appropriate response teams may be dispatched. Directions to the hospital are provided in Attachment G.

c) Remove any injured person(s) from immediate danger and administer first aid as needed.

d) Notify FPS/HSC before resuming work.

10) Reporting procedure - All accidents or injuries must be reported to FPS/HSC.

a) FPS/HSC will post OSHA 200 logs on site.

b) Supervisors and Sub-Contractors contacts will report all accidents or injuries to the FPS/HSC.

c) FPS/HSC willlog and report all accidents or injuries on OSHA 200 logs.

11) Critique of response and follow-up - Following any site emergency, the FPS/HSC will prepare a written report for review by the MFG Corporate Health and Safety Officer and the subcontractor contacts. In addition, any accidents or emergency incidents shall be reported to the relevant local, state and federal agencies by the FPS/HSC as appropriate. The report will include a summary of the emergency, a description of the conditions that led to the emergency, a review of the response actions implemented following the emergency and a discussion of steps that might have been taken to prevent a recurrence of the emergency. Following review of this report, the MFG Corporate Health and Safety Officer will meet with the FPS/HSC to discuss the emergency, the response to the emergency and possible changes to the Site Safety and Health or Emergency Response Plans.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\SM4-50\AV_CZLDnignVW-CZLHASP200l.doc 31 Jllfy ]9, 2004 10.0 REFERENCES

Asarco, 2000. Final Focused Feasibility Study Arkansas Valley Smelter and Colorado Zinc-Lead Mill Site- OU5, Leadville, Colorado. Prepared by MFG Inc. February.

U.S. Environmental Protection Agency (EPA), District VIII, 2000. Record of Decision - Operable Unit 5, • AV/CZL Sites, California Gulch Superfund Site, Leadville, Colorado. September 29th.

U.S. District Court (USDC), District of Colorado, 1994. Civil Action No. 83-C-23 8 8, Consent Decree with ASARCO, Incorporated, Resurrection Mining Company, Newmont Mining Corporation and the Res- ASARCO Joint Venture, Attachment B: Work Area Management Plan for ASARCO Incorporated at the California Gulch NPL Site, Leadville, Colorado. August.

ASARCO Incorporated MFG, Inc. J:\BU»l\5344\5M4.5(AAV_C2LDMisn\AV^ZL HASP200l.doc 32 July 19, 2004 FIGURES LEGEND

APPROXIMATE AV/CZL SITE BOUNDARIES

FORMER SMELTER SITE

STREAM/DRAINAGE

< = • DIRT ROAD

COLORADO ZINC-LEAD MILL SITE

ARKANSAS VALLEY SMELTER SITE

SHARED BOUNDARY WITH OU8

WITH OU3

SCALE

2000 2000 FEET ASARCO Incorporated HEALTH & SAFETY PLAN FIGURE 1-1

OU5 AV/CZL SITE

PROJECT: 015344.51 DATE: FEBRUARY 2001 REV: BY: PCD | CHECKED: DLL MFC, Inc. consulting scientists and engineers ATTACHMENTS ATTACHMENT A

SAFETY COMPLIANCE AGREEMENT SAFETY COMPLIANCE AGREEMENT

MFG, Inc. Personnel Form

PROJECT No.:

PROJECT TITLE:

PROJECT TASK:

I, , (print name) have received a copy of the Site Health and Safety Plan (the "Plan") for the above referenced project. I have read the Plan and agree to comply with all the health and safety requirements contained therein. I understand that I may be prohibited from working on the project for violating any of the Plan requirements.

SIGNATURE: ' DATE:

NOTE: This form must be submitted to the Project Manager.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZL DeiignXAV-CZL HASP2001.doc A-l Jltfy 19, 2004 SAFETY COMPLIANCE AGREEMENT

MFC, Inc. Subcontractor Form

PROJECT No.:

PROJECT TITLE:

PROJECT TASK:

The MFG, Inc. (MFG) Site Health and Safety Plan (the "Plan") provides guidance for site-specific safety requirements. It is not intended to replace any general or specific requirements of a contractor's safety program. MFG personnel will, to the best of their ability, inform contractors of any potential hazard(s) that has been identified during the field investigations. However, contractors will bear the ultimate responsibility for all matters dealing with health and safety in the performance of their appointed work. This responsibility will include, at a minimum, ensuring that their equipment is in proper working order and that their employees and/or authorized representatives are trained and medically fit in accordance with OSHA Standards 29 CFR 1910 and 29 CFR 1926, as appropriate. The contractor is also responsible for informing its' subcontractors of these requirements.

I, ' , (print name) have received a copy of the Plan for the above referenced project. I have read the Plan and agree to comply with all the health and safety requirements contained therein. I understand that I may be prohibited from working on the project for violating any of the Plan requirements.

SIGNATURE: ; DATE: AFFILIATION:

NOTE: This form must be submitted to the Project Manager.

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-50\AV_CZLDesign\AV-CZLHASP200l.doc A-2 Juty 19, 2004 ATTACHMENT B

PLAN ADDENDA THIS SECTION IS INTENDED TO BE BLANK AND IS RESERVED FOR ADDITIONAL ADDENDA TO THIS PLAN ATTACHMENT C

SAFETY MEETING ATTENDANCE FORMS SAFETY MEETING ATTENDANCE FORM

MFG, Inc.

PROJECT No.:

PROJECT TITLE:

PROJECT TASK:

SIGNATURE AFFILIATION

TOPICS COVERED (Check all that apply):

Tasks to be performed Hazard Recognition Personal Protective Equipment Decontamination Air and Personnel Monitoring Site Control Emergency Response Breaks

MFG SITE SAFETY OFFICER:

SIGNATURE: DATE:

ASARCO Incorporated MFC. Inc. J:\BLDOI\3344U344-iO\AV_CZL DeiignVAV-CZL HASP200l.doc July 19, 2004 ATTACHMENT D

MATERIAL SAFETY DATA SHEETS LEAD International Chemical Safety Cards (WHO/IPCS/ILO) Page 1 of 3

International Chemical Safety Cards LEAD ICSC: 0052 LEAD Lead metal Plumbum (powder) Pb Atomic mass: 207.2 CAS # 7439-92-1 RTECS # OF7525000 ICSC #0052 .

TYPES OF ACUTE HAZARDS/ FIRST AID/ HAZARD/ PREVENTION SYMPTOMS EXPOSURE FIRE FIGHTING Not combustible. Finely NO open flames, NO sparks, In case of fire in the divided lead powder is • and NO smoking (if in powder surroundings: all extinguishing FIRE ilammable. Gives off irritating form). agents allowed. or toxic fumes (or gases) in a Eire. Finely dispersed particles form Prevent deposition of dust; explosive mixtures in air. . closed system, dust explosion- EXPLOSION proof electrical equipment and lighting. PREVENT DISPERSION OF IN ALL CASES CONSULT A DUST! STRICT HYGIENE! DOCTOR! AVOID EXPOSURE OF EXPOSURE (PREGNANT) WOMEN! AVOID EXPOSURE OF ADOLESCENTS AND CHILDREN! Abdominal cramps. Ventilation (not if powder). Fresh air, rest. Refer for Drowsiness. Headache. Nausea. Avoid inhalation of fine dust medical attention. i INHALATION Vomiting. Weakness. and mist. Local exhaust or Wheezing. Pallor. breathing protection. Hemoglobinuria. Collapse. t SKIN . EYES Abdominal cramps (further see Do not eat, drink, or smoke Rinse mouth. Induce vomiting Inhalation). during work. Wash hands (ONLY IN CONSCIOUS • 1NGESTION before eating. PERSONS!). Refer for medical attention.

7/snnnn International Chemical Safety Cards (WHO/IPCS/ELO) Page 2 of 3

PACKAGING & SPILLAGE DISPOSAL STORAGE LABELLING Sweep spilled substance into Separated from strong oxidants, containers; if appropriate, moisten strong bases, strong acids, food and first to prevent dusting. Carefully feed stuffs. collect remainder, then remove to safe place. Do NOT let this chemical enter the environment (extra personal protection: P2 filter respirator for harmful particles). SEE IMPORTANT INFORMATION ON BACK

TPQP« nfl^9 Prepared in the coniexi of cooperation between the International Programme on Chemical Safety St. the H-"O^. UU3* Commission of the European Communities ©tPCS CEC 1993 International Chemical Safety Cards LEAD ICSC: 0052

PHYSICAL STATE; APPEARANCE: ROUTES OF EXPOSURE: BLUISH-WHITE OR SILVERY-GREY The substance can be absorbed into the body I SOLID IN VARIOUS FORMS. TURNS by inhalation of its aerosol and by ingestion. TARNISHED ON EXPOSURE TO AIR. M INHALATION RISK: PHYSICAL DANGERS: Evaporation at 20°C is negligible; a harmful P Dust explosion possible if in powder or concentration of airborne particles can, granular form, mixed with air. however, be reached quickly. O CHEMICAL DANGERS: EFFECTS OF SHORT-TERM R Upon heating, toxic fumes are formed. Reacts EXPOSURE: with hot concentrated nitric acid, boiling The substance may cause effects on the T concentrated hydrochloric and sulfuric acids. gastrointestinal tract, blood, central nervous Attacked by pure water and by weak organic system and kidneys, resulting in colics, A acids in the presence of oxygen. shock, anemia, kidney damage and encephalopathy. Exposure may result in N OCCUPATIONAL EXPOSURE LIMITS death. The effects may be delayed. Medical (OELs): . observation is indicated. T TLV: ppm; 0.15 mg/m3 (as TWA) (ACGK 1993-1994). EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: The substance may have effects on the D gastrointestinal tract, nervous system, blood, kidneys and immune system, resulting in A severe lead colics, paralysis of muscle groups of the upper extremities (forearm, wrist and T fingers), anemia, mood and personality changes, retarded mental development, and A irreversible nephropathy. May cause retarded development of the new-bom. Danger of cumulative effect.

PHYSICAL Boiling point: 174Q"C Relative density (water = 1): 11.34 PROPERTIES Melting point: 327.5°C Solubility in water: none This substance may be hazardous to the environment; special attention should be given to air ENVIRONMENTAL and water. In the food chain important to humans, bioaccumulation takes place, specifically in DATA plants and water organisms, especially shellfish.

hrml 3/8/2000 Intei-national Chemical Safety Cards (WHO/IPCS/1LO) Jf age 3 or

NOTES Explosive limits are unknown in literature. Use of alcoholic. beverages enhances the harmful effect. Depending on the degree of exposure, periodic medical examination is indica ted. Do NOT take working clothes home. Refer also to cards for specific lead compounds, e.g., lead chromate (ICSC # 0003), lead(II) oxide (ICSC # 0288). Transport Emergency Card: TEC (R)-61G12b

ADDITIONAL INFORMATION ' 1 ICSC: 0052 LEAD ©IPCS, CEC, 1993

Neither the CEC or the D?CS nor any person acting on behalf of the CEC or the IPCS is IMPORTANT responsible for the use which might be made of this information. This card contains the collective LEGAL views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed NOTICE: requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use.

3/8/2000 ARSENIC International Chemical Safety (Jards

International Chemical Safety Cards

ARSENIC ICSC: 0013 ARSENIC Grey arsenic ' • Metallic arsenic As Atomic mass: 74.9 CAS # 7440-38-2 RTECS # CG0525000 CSC #0013 UN#1558 EC#033-001-00-X TYPES OF ACUTE HAZARDS/ ' FIRST AID/ HAZARD/ PREVENTION SYMPTOMS FIRE FIGHTING EXPOSURE Combustible. Gives off NO open flames. NO contact Powder, water spray, foam, FIRE irritating or toxic fumes (or with strong oxidizers. NO carbon dioxide. gases) in a fire. contact with hot surfaces. . Risk of fire and explosion is Prevent deposition of dust; slight if in the form of fine closed system, dust explosion* EXPLOSION powder or dust when exposed proof electrical equipment and to hot surfaces or flames. [lighting.

EXPOSURE AVOID ALL CONTACT! IN ALL CASES CONSULT A I DOCTOR! Cough. Diarrhoea. Shortness of Closed system and ventilation. Fresh air, rest. Artificial INHALATION breath. Sore throat. Vomiting. [respiration if indicated. Refer Weakness. Grey skin. [for medical attention. Redness. [Protective gloves. Protective Remove contaminated clothes. • SKIN 'clothing. Rinse skin with plenty of water or shower. Redness. or eye protection in First rinse with plenty of water combination with breathing for several minutes (remove EYES protection if powder. contact leases if easily possible), then take to a doctor. Diarrhoea. Nausea. Sore throat. Do not eat, drink, or smoke Rinse mouth. Induce vomiting Unconsciousness. Vomiting during work. Wash hands (ONLY IN CONSCIOUS INGESTION (further see Inhalation). before eating. pERSONS!). Refer for medical attention. PACKAGING & SPILLAGE DISPOSAL STORAGE LABELLING Evacuate danger area! Sweep spilled Provision to contain effluent from fire Do not transport with food and substance into scalable containers. extinguishing. Separated from strong feedstuffs. Carefully collect remainder, then oxidants, acids, halogens, food and T symbol remove to safe place. Do NOT let this feedstuffs. Well closed. Keep in a R: 23/25 chemical enter the environment (extra well-ventilated room. S: (1/2-J20/21-28-45 personal protection: complete UN Hazard Class: 6.1 protective clothing including self- UN Packing Group: II

hrm-//h a7ard.com/msds/mf/cards/file/0013.html 3/8/2000 International Chemical Safety Cards (WHO/IPCS/ILO) Page 2 of 3

[contained breathing apparatus). jl [[Marine pollutant SEE IMPORTANT INFORMATION ON BACK

Prepared in the context of cooperation between (he [ntemaiional Programme on Chemical Safely & ihe ICSC: 0013 Commission of the European Communities © IPCS CEC 1993 9 International Chemical Safety Cards ARSENIC ICSC: 0013 PHYSICAL STATE; APPEARANCE: ROUTES OF EXPOSURE: ODOURLESS, BRITTLE, GREY, The substance can be absorbed into the body METALLIC-LOOKING CRYSTALS. by inhalation of its aerosol, through the skin I and by ingestion. PHYSICAL DANGERS: M INHALATION RISK: Evaporation at 20"C is negligible; a harmful P CHEMICAL DANGERS: concentration of airborne particles can, Upon heating, toxic fumes are formed. Reacts however, be reached quickly. O violently with strong oxidants and halogens R causing fire and explosion hazard. Reacts EFFECTS OF SHORT-TERM with nitric acid, hot sulfuric acid. Toxic arsine EXPOSURE: gas may be formed in contact with acid or The substance irritates the eyes, the skin and T acidic substances and certain metals, such as the respiratory tract. The substance may cause galvanized or light metals. effects on the circulatory system, nervous A system, kidneys and gastrointestinal tract, OCCUPATIONAL EXPOSURE LIMITS resulting in convulsions, kidney impairment, N (OELs): „ severe hemorrhage, losses of fluids, and 3 electrolytes, shock and death. Exposure may T TLV: ppm;'0.01 mg/m (as TWA) Al (ACGIH 1994-1995). result in death. The effects may be delayed. Medical observation is indicated.

D EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: A Repeated or prolonged contact with skin may cause dermatitis. Repeated or prolonged T contact may cause skin sensitization. The substance may have effects on the mucous A membranes, skin, kidneys, liver, resulting in neuropathy, pigmentation disorders, perforation of nasal septum and tissue lesions. This substance is carcinogenic to humans. PHYSICAL Sublimation point: 613°C Solubility in water: none PROPERTIES Relative density (water = 1): 5.7 ENVIRONMENTAL The substance is toxic to aquatic organisms. It is strongly advised not to let the chemical enter DATA into the environment because it persists in the environment NOTES The substance is combustible but no flash point is available in literature. Depending on the degree of exposure, periodic medical examination is indicated. Do NOT take working clothes home. Refer also to cards for specific arsenic compounds, e.g., Arsenic pentoxide (ICSC # 0377), Arsenic trichloride (ICSC # 0221), Arsenic trioxide (ICSC # 0378), Arsine (ICSC #0222).

htto://hazard.com/msds/mf/cards/file/0013.html 3/8/2000 Intel-national Chemical Safety Cards (WHO/IPCS/ILO) rage 3 01

ADDITIONAL INFORMATION 1 II ' - ICSC: 0013 ARSENIC © [PCS. CEC, 1993

Neither the CEC or the EPCS nor any person acting on behalf of the CEC or the IPCS is IMPORTANT responsible for the use which might be made of this information. This card contains the collective LEGAL views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed NOTICE: requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use.

httD://haza!-d.com/msds/mf/caxds/file/0013.html 3/8/2000 ASBESTOS International Chemical Safety Cards CHRYSOTILE ICSC: 0014 CHRYSOTILE Serpentine chrysotile White asbestos b/Ig6Si4H8Oj8 / Mg6(Si4Oj0)(OH)g Molecular mass: 554 CAS # 12001-29-5 RTECS#CI 16478500 ICSC #0014 UN # 2590 (white asbestos) TYPES OF HAZARD/ ACUTE HAZARDS/ PREVENTION FIRST AID/ EXPOSURE SYMPTOMS FIRE FIGHTING Not combustible. II In case of fire in the FIRE surroundings: all extinguishing agents allowed. EXPLOSION PREVENT DISPERSION OF EXPOSURE DUST! AVOID ALL CONTACT! Cough. Breathing protection. Closed • INHALATION system and ventilation. Protective clothing. Remove contaminated clothes. • SKIN Rinse skin with plenty of water or shower. First rinse with plenty of water for several minutes (remove • EYES contact lenses if easily possible), then take to a doctor. Do not eat, drink, or smoke Rinse mouth. • INGESTION during work. Wash hands before eating. cxrm A ™ PACKAGING & SPILLAGE DISPOSAL SIORAGE LABELLING Evacuate danger area! Consult an Well closed. Use dust-proof packaging. expert! Sweep spilled substance into UN Hazard Class: 9 scalable containers; if appropriate, UN Packing Group: III moisten first to prevent dusting. Carefully collect remainder, then remove to safe place (extra personal protection: complete protective clothing including self-contained breathing apparatus). SEE IMPORTANT INFORMATION ON BACK

Tf~>Cf* ftftl 4 Prepared in the context of cooperation between the International Programme on Chemical Safety & the l \_O\-. unit Commission of the European Communities ©1PCSCEC 1993 International Chemical Safety Cards CHRYSOTILE ICSC: 0014 PHYSICAL STATE; APPEARANCE: ROUTES OK EXf OSUKK: I WHITE, GREY, GREEN OR YELLOWISH The substance can be absorbed into the body FIBROUS SOLID. by inhalation. M PHYSICAL DANGERS: INHALATION RISK: P Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, O however, be reached quickly.

R EFFECTS OF SHORT-TERM OCCUPATIONAL EXPOSURE LIMITS EXPOSURE: T (OELs): TLV: 2 fibres/cc (as TWA) Al ppm; mg/m3 A (ACGIH 1992-1993). EFFECTS OF LONG-TERM OR MAK: class III Al (1993). REPEATED EXPOSURE: N The substance may have effects on the lungs, resulting in pulmonary fibrosis and T mesothelioma. This substance is carcinogenic to humans.

D A T A

PHYSICAL Melting point: see Notes°C Relative density (water = 1): 2.55 PROPERTIES ENVIRONMENTAL This substance may be hazardous to the environment; special attention should be given to air. DATA NOTES The substance is heat resistant up to 500°C and completely decomposed at temperature of 1000°C. Smoking enhances harmful effects. Depending on the degree of exposure, periodic medical examination is indicated. Do NOT take working clothes home. The recommendations on this Card also apply to other forms of asbestos. Transport Emergency Card: TEC (R)-913

ADDITIONAL INFORMATION

ICSC: 0014 CHRYSOTILE O IPCS, CEC, 1993

Neither the CEC or the IPCS nor any person acting on behalf of the CEC or the IPCS is IMPORTANT responsible for the use which might be made of this information. This card contains the LEGAL collective views of the IPCS Peer Review Committee and may not reflect in all cases all the NOTICE: detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. ATTACHMENT E

MFC PERSONAL PROTECTIVE EQUIPMENT PROGRAM

E-l Levels of Protection E-2 Outline for Selecting Respiratory Protective Devices E-3 Respirator Fit Test Record E-4 Respirator Inspection Record E-5 Respirator Program Evaluation Checklist 1.0 MFC PERSONAL PROTECTIVE EQUIPMENT PROGRAM

MFC has developed and implemented a personal protective equipment (PPE) program to comply with the requirements of 29 CFR 1910.120 (g)(5). This PPE program contains procedures for:

1. PPE use and limitations;

2. PPE maintenance and'storage;

3. PPE decontamination and disposal;

4. PPE training and proper fitting;

5. PPE donning and doffing;

6. PPE inspection prior to, during, and after use;

7. Evaluation of the PPE program effectiveness; and

8. Limitations during temperature extremes and heat stress, and other appropriate medical considerations.

The PPE program also includes a respiratory protection program (RPP) to comply with 29 CFR 1910.134.

The purpose of PPE is to shield individuals from safety and/or health hazards that may be encountered while performing site work. Careful selection, training, use and maintenance of PPE is necessary to minimize the risk to individuals while they are performing work in potentially hazardous environments. The type of PPE to be worn by MFG employees will be evaluated by the degree of exposure to a potential hazard on a site-to-site basis. Specific PPE use will be outlined in the Site Health and Safety Plan (Section 3.0).

The minimum PPE to be worn by MFG employees at most sites will consist of head, eye, foot and, in some cases, hearing protection. On sites where there is a potential for exposure to specific physical hazards or to health hazards other than physical hazards, MFG employees may be required to wear protective clothing and/or respiratory protective devices. The Site Health and Safety Plan will outline the levels of protection required of each individual for each task to be performed. The MFG Site Safety Officer will be responsible for determining when conditions warrant upgrading or downgrading the level of protection. The Site Health and Safety Plan will also outline PPE decontamination and disposal procedures, PPE donning and doffing procedures, limitations during temperature extremes and heat stress, etc. ASARCO incorporated MFC, Inc. j:\BLDoi\5J4JV5M4.jffvAv_czi. o«igiMv_czi. HASP ATTACH E.d« E-l December I. 2003 Training in the proper use and limitation, maintenance and storage, fitting, donning and doffing, etc., of PPE will be initially received by employees in an OSHA off-site hazardous materials health and safety course (i.e., 40-hr course). At a minimum, these skills will be maintained by attendance of annual refresher courses. Supplemental training may be provided by qualified MFC personnel, outside contractors, vendors, etc., on an as needed basis. It is the employee's responsibility to read and become familiar with the manufacturer's instructions concerning, but not limited to, the use, limitation, care, storage, etc., of all PPE.

The PPE program will typically be evaluated on an annual basis. Training and/or literature obtained by MFG personnel will be used to revise and update the procedures, provisions, etc., presented in the following sections. In addition, information, experience, etc., obtained during projects, or knowledge of new techniques, may be used to revise the PPE program at any time.

The following sections briefly describe the use of head, eye, foot, hearing, and respiratory protective equipment. In addition, the use of chemically resistant clothing is also addressed. Infrequently, employee may be required to use PPE not addressed in these sections for a specific project-related task. On such occasions, the procedures fof'>the use and limitation, maintenance and storage, decontamination and disposal, training and proper fitting, donning and doffing, inspection, evaluation of effectiveness, and. medical considerations will be contained in the Site Health and Safety Plan (Section 3.0).

1.1 Head Protection

The use of helmets (hard hats) for the protection of heads from impact and penetration from falling and flying objects is specified under 29 CFR 1910.135. In general, MFG employees will be required to wear hard hats when the potential exists for a threat from an overhead object. In many cases, mandatory use of hard hats is required by clients while performing work at any location on their facility.

As specified in 29 CFR 1910.135, MFG will supply employees with head protection that meets the requirements of the American National Standards Institute (ANSI) Standard Z89.1 (Requirements for Industrial Head Protection).

The hard hats will be used, cleaned, maintained, etc., by the employee per the manufacturer's instructions. Employees will inspect hard hats prior to each use to ensure that the hat is in proper condition. Use of ASARCO Incorporated MFG, Inc. I >BLDOI'.J344\5W4-.'IO\AV_CZL Dttign\AV_CZL HASP ATTACH E.doc E-2 December I, 2003 head protection with structural damage, or alterations that may compromise the structural integrity of the hard hat, is prohibited. If defects are detected, the hat will be exchanged. Any alterations to the hat such as, but not limited to, drilling of holes, painting, or cleaning with solvents and/or thinners, or modifications to the suspension can compromise the structural integrity of the hat.

1.2 Eye and Face Protection

The use of protective eye and/or face equipment is specified under 29 CFR 1910.133. MFG employees will be required to wear eye protection on all job sites. The type of protection required will be a function of the potential threat and will be specified in the Site Health and Safety Plan (Section 3.0). In general, safety glasses with permanently attached side shields will be required when the principal threat is physical (e.g., flying objects). When the potential for splash exists, goggles or face shields may be required.

MFG will supply employees with safety glasses, goggles, and/or face shields that meet the requirements of ANSI Standard Z87.1 (Occupational and Educational Eye and Face Protection). For employees who require the use of corrective lenses, MFG will reimburse those individuals for the purchase of one pair of glasses that comply with the above ANSI Standard. The eye glasses must have permanently attached side shields.

Face and eye protection will be used, cleaned, maintained, etc., by the employee per the manufacturer's instructions. Employees will inspect eye and/or face protection prior to each use to ensure that it is in proper condition. Use of eye and face protective equipment with structural or optical defects is prohibited. If defects are detected, the eye or face protection will be exchanged.

1.3 Foot Protection

The use of foot protection (i.e., steel-toe boots) is specified under 29 CFR 1910.136. MFG employees will be required to wear foot protection on all job sites. The construction of the foot protection (e.g., leather, PVC, etc.) will be a function of the potential threat and will be specified in the Site Health and Safety Plan (Section 3.0).

MFG employees will generally be responsible for the purchase of their own foot protection. MFG will reimburse employees for the purchase of one pair of leather boots and one pair of waterproof (e.g., PVC)

ASARCO Incorporated MFG, Inc. J:\BLD01\J3-U\M-U.JO\AV_CZLDnijn\AV_CZLHASPATTACHE.doc E-3 December I. 2003 boots. On projects that necessitate the purchase of footwear composed of specific chemical resistant materials, MFG will supply personnel with the appropriate footwear.

Employees are responsible for ascertaining that the footwear they purchase complies with the requirements of the ANSI Standard Z41.1 (Men's Safety-Toe Footwear). The footwear will be used, cleaned, maintained, etc., by the employee per the manufacturer's instructions. Employees will inspect foot protection prior to each use to ensure that it is in proper condition. Use of footwear with structural defects, worn soles, cracks, etc., is prohibited. If defects are detected, the boots will be exchanged.

1.4 Hearing Protection

Exposure to high noise levels can cause hearing loss or impairment. There is no cure for noise-induced hearing loss, so the prevention of excessive noise exposure is the only way to avoid hearing damage. Protection against the effects of occupational noise exposure is specified in 29 CFR 1910.95. This OSHA standard sets an 8-hour time-weighted-average (TWA) sound exposure level of 90 decibels (dBA); the 8- hour TWA action level is set at 85 dBA.

MFG does not routinely monitor noise levels at job sites. However, it is MFG's policy that hearing protection be used whenever the potential exists for exposure to excessive noise levels. As such, it is the responsibility of the employee to use company-supplied hearing protection whenever project work is performed adjacent to any operating machinery, etc., or the project involves the use of any equipment, tools, etc., no matter how long the duration. The following data, extracted from "Fundamentals of Industrial Hygiene ' (Table 9-B), are provided as examples of noise levels generated by common activities/equipment: average residence - 40 dBA; noisy office - 80 dBA; passing truck - 100 dBA; turbo jet engine-150 dBA.

Disposable earplugs will be used one time, per the manufacturer's instruction, and then discarded. Non- disposable hearing protection will be used, cleaned, maintained, etc., by the employee per the manufacturer's instructions. Employees will inspect hearing protection prior to each use to ensure that it is in proper condition. Use of hearing protection with structural or acoustical damage is prohibited. If defects are detected, the hearing protection will be exchanged.

1 National Safety Council, 1988, page 168.

ASARCO Incorporated MFG, Inc. V_c2L Dejign\AV_-czLHASPATTACHE.doc E-4 December 1, 2003 1.5 Chemically Resistant Clothing

Protective clothing prevents potentially dangerous chemicals from entering the body, usually through the skin. Such clothing also protects the body from bums and cold or wet conditions. Protective clothing can range from gloves to fully encapsulated suits. The chief characteristics of chemical protective clothing include:

1. Strength; 2. Flexibility; 3. Thermal limits; and 4. Chemical resistance.

Strength depends on the material's tensile strength and its resistance to abrasions, punctures, and tears. Flexibility allows the individual to move and work effectively. Gloves especially must be flexible, and in cold weather this is sometimes a problem. Thermal limits refer to the material's ability to maintain its protective capacity in temperature extremes. Thermal limits also affect worker mobility in cold weather and heat transfer in hot weather.

Chemical resistance refers to a material's ability to retain its structural integrity and protective qualities. Material can degrade when a contaminant or chemical reacts with the material. All material eventually degrades. Swelling, shrinking, brittleness, softness, discoloration, elongation or cracking indicates deterioration. These conditions should alert the worker to the possibility that the material is not providing adequate protection.

Chemical resistance can also be described in terms of:

1. Degradation; 2. Breakthrough time; 3. Penetration; and 4. Permeation.

Degradation is the change of the material's physical properties as a result of the chemical's negative effects. Breakthrough time is the time it takes the chemical to pass through the protective material until it is first detected by an analytical instrument. Penetration refers to bulk chemical flow through the protective material. Penetration is not a material property but rather a function of garment design and construction.

ASARCO Incoiporated MFG. Inc. J:\BLDOI\3JWJ344-50iAV_CZLDMign\AV.CZL HASP ATTACH £ doc E-5 December I. 2003 Penetration can occur through:

1. Material defects; 2. Seams; 3. Sleeves; 4. Pant legs; 5. Zippers, button holes or other enclosures; 6. Neck or head openings; and 7. Porous material.

Aerosol particulates, mists, gas, and vapors have the greatest penetration ability. Penetration can be prevented by:

1. Stitched and lapped or sealed areas; 2 Self-sealing zipper and overlap flap; 3. Hood with elastic sealed connection; 4. Elastic wrists and ankles; 5. One-piece suit; and 6. Taping seams and openings such as ankles, wrists, and zippers.

The significance of penetration depends on skin absorptivity and the following contaminant characteristics:

1. Toxicity; 2. Concentration; 3. Physical phase; and 4. Exposure route.

Use of a garment constructed of an impenetrable material can cause the possibility of heat stress because outside air is not allowed to penetrate the material; thus, little air moves within the garment. Cooling devices (e.g., ice vests) are not always effective or efficient.

Permeation (i.e., chemical movement at the molecular level through the material) occurs once the chemical has broken through the material. Because movement is by molecular diffusion, movement is microscopic and unnoticeable by the unaided eye. The contaminant, which can condense inside the material, will tend to reach an equilibrium concentration gradient.

Permeation rate, the rate of chemical movement through the material once breakthrough has started, can be very fast or very slow. Permeation rate is:

ASARCO Incorporated MFG. Inc. j:\BLDoi\53*M344.wuw_czL o«igii'.Av_czi. HASP ATTACH E.doc E-6 December I, 2003 1. Inversely proportional to material thickness (discounting fillers); 2. Directly proportional to contaminant concentration gradient; and 3. Directly proportional to the amount of direct contact with the contaminant.

Chemical resistance of the protective materials is based on laboratory degradation or permeation tests. Laboratories perform these tests at room temperature; higher temperatures may decrease permeation time and rate. These data are approximate values because manufacturers= products, even products made of the same material, can have different properties. In addition, considerations should be given to the following facts:

• Eventually all chemicals pass or permeate through protective materials, and this can happen without any visible indications; • A material may protect a worker well against one chemical but poorly against another; no single material is an absolute barrier against all chemicals; • Garments that look alike do not necessarily possess identical protective qualities; and • When a material starts to absorb a chemical, the chemical will continue to permeate through the material even though the material may not be in direct contact, with the chemical.

Specific considerations for glove, suit and boot selection include the following:

• Hands will probably come in contact with the greatest variety of contaminants; • Gloves generally need to withstand longer exposure times; • Gloves need to be flexible because intricate work is usually done with the hands; • Inexpensive disposable suits can be worn over fully encapsulated suits to reduce contamination of the underlying suit; i • Garments that workers do not dispose of must be decontaminated; • Boots must withstand long exposure times; especially if workers must stand in liquid; and • Physical and psychological stress caused by the garment, especially the fully encapsulated suits, which can cause the wearer claustrophobia.

Chemical protective clothing will be required whenever the potential exists for exposure to hazardous concentrations of aqueous, solid, particulate and/or gaseous contaminants. In many instances, chemically protective clothing will be used in conjunction with respiratory protective devices (Section 4.6). Used together, combinations of these PPE will offer different levels of protection (i.e., Levels A, B, C, and D). The appropriate level of protection selected will be a function of the potential concentrations of the contaminant(s), the forms in which they are present, the route(s) of potential exposure (i.e., inhalation, ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\JJ44.JOVAV_CZLDeiiglMV_CZLHASP ATTACHE.doc E-7 December I, 2003 skin absorption, ingestion, eye or skin contact, etc.), and the employee's work requirements and task- specific conditions. Examples of the types of PPE that may be required for the different levels of protection are summarized in Attachment E-l.

The Site Health and Safety Plan will outline the levels of protection required of each individual for each task to be performed. The levels of protection will be assessed using site-specific chemical and physical data. The selection of PPE will be performed using guidelines in documents such as "Personal Protective Equipment for Hazardous Materials Incidents: A Selection Guide ' and "Guidelines for the Selection of Chemical Protective Clothing 3. The MFG Site Safety Officer will be responsible for determining when conditions warrant upgrading or downgrading the level of protection. This determination will be made on the basis of "action levels" established in the Site Health and Safety Plan.

The Site Health and Safety Plan will also outline decontamination and disposal procedures, donning and doffing procedures, etc., for chemically protective clothing. Employees will inspect protective clothing prior to use to ensure that it is in proper condition. Use of protective clothing with structural defects is prohibited. If defects are detected, the protective clothing will be exchanged. In general, gloves, outer boots, and disposable coveralls will be replaced daily. If they become damaged, they will be replaced immediately.

1.6 Respiratory Protection

The use of respiratory protection is specified under 29 CFR 1910.134. The primary objective of this protection is to limit employee exposure to harmful atmospheric conditions. Potential exposure will be initially limited by engineering control measures, to the extent practical. When effective engineering controls are not feasible or effective, appropriate respiratory protection will be used.

MFG has developed the following Respiratory Protection Program (RPP) to comply with 29 CFR 1910.134(a)(2). It is the responsibility of the employee to use the provided respiratory protection in accordance with the instructions and training provided by the manufacturer, OSHA training courses, Site Health and Safety Plans, etc. The majority of this section is oriented to the selection, use, maintenance,

1 NIOSH, 1984

3 ACGIH. 1987. Third Edition.

ASARCO Incorporated MFG. Inc. J:\BLDOI\5344\M44-50'.AV_CZL DclignVAV_CZL HASP ATTACH E.doc E-8 December 1, 2003 etc. of air-purifying respirators (APRs), or Level C respiratory protection. Additional instruction, training, etc. for care and use of supplied air respiratory equipment (e.g., Levels A and B of respiratory protection) will be included in Site Health and Safety Plans, as appropriate, and incorporated into the RPP per the provisions described in Section 4.6.7.

1.6.1 Standard Operating Procedure for the Selection and Use of Respirators i i

The document "NIOSH Respirator Decision Logic 4, or equivalent, will be used as guidance for selecting appropriate levels of respiratory protection.. The generalized process for selecting respiratory protection is summarized on the flowchart in Attachment E-2F. Outside consultation, manufacturers= assistance, and other recognized authorities may be consulted if there is any doubt regarding proper selection and use.

1.6.2 Respirator Selection

Respirators will be selected on the basis of hazards to which the worker may be potentially exposed. All selections will be made using site-specific chemical and physical data. The selection process will be documented in the Site Health and Safety Plan.

1.6.3 Instruction and Training

Employees will be instructed and trained in the proper use of respirators and their limitations. Training will provide the employee an opportunity to handle the respirator, have it properly fitted, test its face piece to face seal, wear it in normal air for a long familiarity period, and finally wear it in a test atmosphere. Employees will receive fitting instructions, including demonstrations and practice in how the respirator should be worn, how to adjust it, and how to determine if it fits properly.

Training in the proper use and limitations, maintenance, and storage, fitting, donning, doffing, etc., of respirators will be initially received by employees in an OSHA off-site hazardous materials health and safety course. At a minimum, these skills will be maintained by attendance at an annual refresher course.

4 NIOSH, 1987; Publication No. 87-108

ASARCO Incorporated MFC, Inc. j:\BLDoi\tt44\5j44-5o-Av_czL Deiign>Av_czL HASP ATTACH E doc E-9 December 1, 2003 Respirators will not be worn when conditions prevent a good face seal. Such conditions may be growth of a beard, sideburns, a skull,cap that projects under the face piece, or temple pieces on glasses. No employees who are required to wear respirators may wear beards. Also, the absence of one or both dentures can seriously affect the fit of a face piece. To assure proper protection, it is the employee's responsibility to check the face piece fit each time the employee puts on the respirator. This will be done by following the manufacturer's face piece-fitting instructions.

Employees who may be required to wear respirators will be qualitatively fit-tested on an annual basis. However, under certain work situations, it may be necessary to perform quantitative fit testing. Fit testing documentation (Attachment E-3 or equivalent) will be maintained in the corporate files.

1.6.4 Cleaning, Disinfection, and Storage

Where practicable, respirators will be assigned to individual employees for their exclusive use. Employees will be responsible for regularly cleaning and disinfecting their respirators. Respirators issued for the exclusive use of one employee will be cleaned after each use, or more often, if necessary. Respirators used by more than one employee will be thoroughly cleaned and disinfected after each use. Respirators will be cleaned and disinfected per the manufacturer's instructions.

Employees must store their respirators to protect against dust, sunlight, heat, extreme cold, excessive moisture, or damaging chemicals. Protection against mechanical damage will also be the responsibility of the employee. Respirators will be stored so that the face piece and exhalation valve will rest in a normal position to prevent the rubber or plastic from reforming in an abnormal shape.

1.6.5 Inspection

Employees will be responsible for the routine inspection of their respirators. Respirators will be inspected for wear and deterioration of their components before and after each use. Special attention will be given to rubber or plastic parts. The face piece, especially the face seal surface, headband, valves, connecting tube, fittings, and canister connections must be in good condition. At a minimum, respirators will be inspected during the annual fit test procedure (Section 4.6.3). If defects are detected, the respirator will be repaired/replaced. Inspection of the respirators will be documented through the use of the record

ASARCO Incorporated MFG. Inc. j:\BLDoi\»M\j344.3ovAv_czLDcsiBnuv_czLHASPATTACHE.doc E-10 December 1, 2003 contained in Attachment E-4, or equivalent. These inspection records will be maintained in the corporate files.

1.6.6 Surveillance

Appropriate surveillance of work area conditions (e.g., ambient air monitoring, personal monitoring, etc.) and degree of employee exposure or stress will be performed per the Site Health and Safety Plan.

1.6.7 Program Evaluation

Regular inspection and evaluation will be performed to assess the continued effectiveness of the RPP. The Corporate Health and Safety Officer may make periodic inspections of employee respirators to ensure compliance with the cleaning, disinfection, storage, inspection requirements outlined in Sections 4.6.4 and 4.6.5. In addition, the Site Safety Officer may make periodic audits of job sites to ensure compliance with the RPP. The program evaluations will be documented through the use of the form contained in Attachment E-5, or equivalent. These evaluation records will be maintained in the corporate files.

1.6.8 Medical Monitoring

Employees will not be assigned to tasks requiring use of respirators unless it has been determined that they are physically able to perform the work and use the equipment. The respirator user's medical status will be reviewed annually (Section 2.0).

1.6.9 Certification

Respirators will be MSHA or NIOSH approved. Supplied air will meet or exceed Grade D breathing air specifications. A small, backup SCBA (escape pack) will be carried by personnel when using an SCBA or air-line respirator.

ASARCO Incorporated MFC, Inc. J:VBLDOI\i344\«44.JO\AV_CZLDefifmAV_CZLHASPATTACHE.doc E-l 1 December 1, 2003 ft ATTACHMENT E-l Levels of Protection

Personal protective equipment is generally divided into four categories based on the level, or degree, of protection provided. The following are meant to serve as guidelines which can be used to select,the appropriate level of protection; optional equipment is not included.

LEVEL A To be used when the greatest level of skin, respiratory and eye protection is. required.

• Full face-piece positive pressure or pressure-demand SCBA or air-line respirator with escape SCBA. • Totally encapsulating chemical protective suit. • Gloves: inner, chemical resistant. • Boots: chemical resistant, steel-toe. • Hardhat. • Two-way radio (worn inside suit).

LEVEL B The highest level of respiratory protection is necessary but a lesser level of skin protection is needed.

• Full face-piece positive pressure or pressure-demand SCBA or air-line respirator with escape SCBA. • Hooded, chemical resistant coveralls. • Gloves: outer, chemical resistant. • Gloves: inner, chemical resistant. • Boots: chemical resistant, steel-toe. • Hardhat.

LEVEL C The concentration(s) and type(s) of airborne substance(s) is known and the atmosphere is not oxygen deficient.

• Full face or half mask air purifying cartridge respirator. • Safety glasses or goggles (if half-mask respirators are used). • Hooded, chemical resistant coveralls.

ASARCO Incorporated MFG. Inc. j:\BLDoi'.53+w344.5oiAv_czi. DnisniAv.czL HASP ATTACH E.doc E-l. 1 December 1, 2003 • Gloves: chemical resistant. • Boots: chemical resistant, steel-toe. • Hard hat.

LEVEL D A work uniform affording minimal protection; used for nuisance contamination only.

• Safety glasses or goggles. • Boots: steel-toe. • Hard hat.

ASA RCO Incorporated MFG. Inc. j:iBLDoi>.534*5}44.jo\Av_czLDcsigiv.AV_-c2i-HASPATTACHE.doc E-1.2 December I, 2003 ATTACHMENT E-2

Outline For Selecting Respiratory Protective Devices The Resplralor DeDeci'sioc n Logic Sequence Is presented in'Figure 1 in the' form. of a flow.chart This flow chart can be used to identify suitable classes of" respi rators for adequate protection agajnst specific1 environmentaj condftfons.

II sv\te conumiiUMl

KEY: CC— CoftUfn'ftiftl Concenlfj'.ion EL-Ei?ajwfj Unit E5U — End o( Strr'ce Life Indlcilor Fr— Full Fictptcci IOLH— Im

A1 • 5CSA wim Pr o;sfjl«d In PO of PP mode. B* >T^?i C juppliti-ilf rnpinlof (itrllne) opeftte^ In P0-«r P? fiio^e'wllft »'uiilijfy SCSJk.

C'(« Eseipe ftjpifilof cf gii fr.JJ^ wilft lilt'{(/jofi«nt (Svbpinjnpfi i); 1( 0; delicienl, Ifttn 5CSX

Flgura 1. — Flow Chart of Rtsptulor Decision bg'c Sequence ATTACHMENT E-3

Respirator Fit Test Record RESPIRATOR FIT TEST RECORD MFG, Inc.

A: EMPLOYEE: SOCIAL SECURITY NO: ' EMPLOYEE JOB TITLE/DESCRIPTION:

B: RESPIRATOR TYPE: MANUFACTURER: _ MODEL: SIZE:

C. CONDITIONS WHICH COULD AFFECT RESPIRATOR FIT:

«J BEARD ^ FACIAL SCAR ^MOUSTACHE •J GLASSES

COMMENTS:

D. FIT CHECKS:

NEGATIVE PRESSURE ^ PASS ^ FAIL NOT DONE POSITIVE PRESSURE ^PASS NOT DONE

E. FIT TESTING:

•J QUANTITATIVE ^ ISOAMYL ACETATE IRRITANT SMOKE QUALITATIVE QUALITATIVE

F. FIT FACTOR:

COMMENTS:

ASARCO Incorporated MFC. Inc. V_CZL Deli|niAV_CZL HASP ATTACH E.doc E-3.1 December 1. 2003 ATTACHMENT E-4

Respirator Inspection Record RESPIRATOR INSPECTION RECORD MFG, Inc.

1. EMPLOYEE: SOCIAL SECURITY NUMBER: EMPLOYEE JOB TTTLEyDESCRIPTION:

2. RESPIRATOR TYPE: MANUFACTURER: MODEL: SIZE:

3. DEFECTS FOUND A. Face piece B. Inhalation Valve C. Exhalation Valve Assembly D. Headbands E. Cartridge Holder F. Cartridge/Canister G. Filter H. Harness Assembly L Hose Assembly J. Speaking Diaphragm K. Gaskets L. Connections , M. Other Defects

ASARCO Incorporated MFG. Inc. v_czL o«iin\Av.czL HASP ATTACH E.doc E-4.1 December J, 2003 ATTACHMENT E-5

Respirator Program Evaluation Checklist RESPIRATOR PROGRAM EVALUATION-CHECKLIST In general, the respirator program should be evaluated for each job or at least annually, with program adjustments, as appropriate, made to reflect the evaluation results. Program function can be separated into administration and operation.

'A. Program Administration

1) Is there a written policy which acknowledge employer responsibility for providing a safe and healthful workplace, and- assigns 'program responsibility, accountability, and authority? i ' i- , • • 2) Is program responsibility vested in one individual who is knowledgeable and who can coordinate all aspects of the program at the job site?

__ 3) Can feasible engineering controls or work practices eliminate the need for respirators?

4) Are there written procedures/statements covering the various aspects of the respirator program, including:

designation of atv.administrator; respirator selection; purchase of MSHA/NIOSH certified equipment; ' medical aspects of respirator usage; issuance of equipment; fitting; '• training; . • maintenance, storage, and repair; „ Inspection; 1 . . use under special conditions; and _ work are surveillance?

B. • Program Operation

1) Respiratory protective equipment selection

_; Are work are conditions and worker exposures properly surveyed?

Are respirators selected on the basis of hazards to which the worker is exposed?

. Are selections made by individuals knowledgeable of proper selection procedures?

2) ' Are only certified respirators purchased and used; do they provide adequate protection for the specific hazard and concentration of the contaminant? i * 3) ' Has a medical evaluation of the prospective user been made to determine physicaJ and psychological ability to wear the selected respiratory protective equipment?

4) \Yhere practical, have respirators been issued to the users for their exclusive use, and are ' there records covering issuance? 5) • Respiratory protective equipment fitting

Are the users given the opportunity to try on several respirators to determine. whether the respirator they will subsequently be wearing is the best fitting one?

Is the fit tested at appropriate intervals?

Are those users who'require corrective lenses properly fitted?

Are users prohibited from wearing contact lenses when using respirators?

Is the face-piece-to-face seal tested in a test atmosphere?

Are the workers prohibited from wearing respirators in contaminated work areas when they have facial hair or other characteristics may cause face-seal leakage? 6) Respirator use in the work area . Are respirators being worn correctly (i.e., head covering over respirator straps)? Are workers keeping respirators on all; the time while ia the work area? 7) Maintenance of respiratory protective equipment Cleaning and Disinfecting Are respirators cleaned and disinfected after each use when different people use the same device, or as frequently as necessary for devices issued to individual 1 users? Are proper methods of.cleaning and disinfecting utilized? Storage Are respirators stored in a manner so as to protect them from dust, sunlight, heat, excessive cold or moisture, or damaging chemicals? Are respirators stored properly in a storage facility so as to prevent them frqm deforming? Is storage in lockers and tool boxes permitted only if the respirator is in a carrying case or carton? Inspection Are respirators inspected before and after each use and during cleaning? Are qualified individuals/users instructed in inspection techniques? Is respiratory protective equipment designated as "emergency use" inspected at least monthly (in addition to after each use)? Are SCB A incorporating breathing gas containers inspected weekly for breathing gas pressure? Is a record kept of the inspection of "emergency use" respiratory protective equipment?

. Repair Are replacement parts used in repair, those of the manufacturer of the respirator?

Are respirators made by manufacturers or manufacturer-trained individuals?

8) Special use conditions

i . • Is' a procedure developed for respiratory protective _ equipment usage in atmospheres immediately dangerous to life or health? Is a procedure developed for equipment usage for entry into confined spaces? 9) • Training Are users trained In proper respirator use, cleaning, and inspection? 'Are users trained in the basis for selection of respirators? • '- -\) f Are users evaluated, using competency-based evaluation, before and after training? ATTACHMENT F

MFC MEDICAL SURVEILLANCE PROGRAM 1.0 MFC MEDICAL SURVEILLANCE PROGRAM

Employees who are or may be exposed to hazardous substances or health hazards at job sites at or above the established permissible exposure limits (PELs) will be included in a medical surveillance program in accordance with OSHA standard 29 CFR 1910.120 (f). The medical surveillance program will involve medical examinations performed at the initiation of employment (baseline examination) and on an annual basis thereafter. Exceptions may be made where new employees have had a medical examination within six months that is equivalent tor or more stringent than, that required by MFG, provided the employee can provide proof of same. Additional examinations may be performed as conditions warrant. At the termination of employment, an exit physical will be performed. This exit physical may be waived if (1) the employee has had a full medical examination within the last six months; (2) it can be established that the employee has not been exposed to hazardous substances at or above the PELs since their full medical examination; and (3) the employee has not developed any symptoms associated with exposure to hazardous substances. If an employee voluntarily waives the right to an exit physical, they will be required to sign a statement to that effect.

MFG will provide for the cost of the medical surveillance. Results of the examinations will be provided to the employee, and will be maintained by the medical facilities performing the examinations for each of the MFG offices (Attachment A). The physician's written opinion will be maintained in the corporate files. Employee medical records will be identified by the name and social security number of the employee. Employee medical complaints related to exposure to hazardous substances will also be kept in these files. Employees will be given full access to their medical records during and after their employment in accordance with OSHA standard 29 CFR 1910.20. These records will be maintained for at least the duration of employment plus 30 years.

The medical examinations will be performed by a licensed physician. The physician will be provided, at the time of examination, the following information:

• A copy of the federal OSHA standard 29 CFR 1910.120 (if not already in their possession); • A description of the employee's duties as they relate to the employee's potential for exposure; • The employee's exposure levels or anticipated exposure levels to hazardous substances;

ASARCO Incorporated MFG. Inc. J:\BLDOI\JJ-W\H-W.MW_CZL o«ii»n\AV_czL HASP ATTACH F.doe F-l December 2003 • A description of any PPE used or to be used by the employee; and • Information from previous medical examinations of the employee that is not readily available to the examining physician.

The medical examinations will include medical and occupational history, with special emphasis on symptoms related to the handling .of hazardous substances and to fitness for duty including the ability to wear required PPE. A panel of tests, designed to evaluate blood forming, kidney, liver and metabolic functions, will be performed. The basic medical examination will include:

• Complete medical and occupational history during the initial examination. Subsequent briefings will update the physician as to the employees= history since the previous examination; • Comprehensive physical examination, including: • Audiogram; • Complete blood count (CBC) and chemistry profile; • Urinalysis, including dipstick and microscopic examinations; • Pulmonary function test, including forced expiratory volume in one second (FEVj) and forced vital capacity (FVC); and • Electrocardiogram (EKG) (Baseline, every three years thereafter); • Chest X-Ray (baseline, every three years thereafter); and • Supplemental tests to be performed at the discretion of the physician or if there is the likelihood of potential on-site exposure to a particular toxicant. These tests may include: Update immunization shots as needed (e.g., tetanus and diphtheria); and

Blood screening for specific heavy metals and/or organic compounds.

Following the medical examination, the physician will transmit a written report to MFG (Attachment B or equivalent) that will only contain the following:

• The physician's opinion as to whether the employee has any detected medical conditions which would place the employee at increased risk of material impairment of the employees health from work in hazardous waste operations; • The physician's recommended limitations upon the employee's assigned work, including the ability to wear PPE (e.g., respiratory protection) under the various conditions expected at job sites; and • A statement that the employee has been informed by the physician of the results of the medical examination and any medical conditions which require further

ASARCO Incorporated MFG. Inc. J:iBLDOI\i344VJ34J-50',AV_CZL Dtlitn\AV_CZL HASP ATTACH f doc F-2 December 2003 examination or medical treatment. Any subsequent testing or treatment may be the responsibility of the employee.

The physician's written report will be maintained in the corporate files. Specific results of the medical monitoring will be transmitted to the employee only.

ASARCO Incorporated MFC, Inc. J:\BLDOI\J344\JJil-}0'AV_CZL Dcsign\AV_CZL HASP ATTACH F.doc F-3 December 2003 ATTACHMENT G

SITE LOCATION MAP AND EMERGENCY ROUTE TO HOSPITAL .5 MILES

DIRECTIONS: 1. COUNTY RD. #31 TO HWY. 24 AT STRINGTOWN. LEFT ON HWY. 24.

2. NORTHEAST ON HWY. 24.. LEFT ON WEST 6TH.

3. WEST ON WEST 6TH. LEFT ON WASHINGTON ST.

4. SOUTH ON WASHINGTON ST, LEFT ON WEST 4TH TO ST. VINCENT'S HOSPITAL. ASARCO Incorporated HEALTH AND SAFETY PLAN FIGURE G-1 TOTAL DISTANCE: -3.3 MILES SITE LOCATION MAP AND EMERGENCY ROUTE TO HOSPITAL HIGHLIGHTED DIPlCTiON OF EMERGENCY ROUTE FROM PROJECT SITE TO ST. PROJECT: 015344.51 DATE: FEBRUARY 2001 VINCENT'S HOSPITAL. REV: BY: PCD | CHECKED: DLL MFC, Inc. MAR SOURCE: DeLORME - STREET ATLAS USA V6.0. consulting scientists and engineers APPENDIX I

STORMWATER ANALYSES FOR THE SOIL COVERS

1.1 Infiltration Analysis 1.2 Erosion Calculations 1.3 Supporting Calculation for Run-on/Run-off Control and Stormwater Management APPENDIX 1.1

INFILTRATION ANALYSIS APPENDIX I.I

1.0 INFILTRATION ANALYSIS

The appendix presents an analysis of the remedial design in terms of its effect on reducing surface water infiltration through flue dust, non-residential area soils and tailing. The principal components of the remedial design are as follows:

Excavation and relocation of flue dust into a fully-encapsulating geomembrane lined repository on the AV Smelter site; and Excavation and consolidation of tailing and non-residential area soils at the AV Smelter and CZL Mill Sites, and establishment of an 18-inch thick soil cover over the consolidated material

Because flue dust, tailing, and non-residential area soils have differing potentials for releasing metals to infiltrating surface water, separate analyses were performed for each material. Evaluations were performed by assessing surface water percolation rates through the materials without cover (i.e., existing conditions) and with the cover using the HELP model (Schroeder et. al., 1994). Calculated unit area percolation rates were then applied to the material area to estimate, the amount of infiltration. The infiltration rates from each area were then summed to provide the total infiltration through the source material and cover.

1.1 Summary of Principal Assumptions

As stated above, because the source materials have differing potentials to release metals, analyses were performed separately for each source material under each comprehensive remedial alternative. Details of the assumptions made in the analysis for each source material are provided below.

Flue Dust - 'On-site Repository: The flue dust would be consolidated in a fully encapsulated repository. The repository would be lined with a 60-mil geomembrane liner protected by an 18-inch vegetated soil cover. The repository would be approximately 0.55 acres in size and flue dust would be an average of 15 feet thick. A lateral drainage layer would be installed on top of the liner to direct any surface water which infiltrates through the soil cover away from the liner.

ASARCO Incorporated MFG. Inc. J:\BLMI\5344\3344-50\AVJ2LDejign\JnriltrationAnalysi5.doc 1 Jufy 19, 2004 Tailing - Soil Cover Over Consolidated Tailing: assumed 0.45 acres at 5 foot depth mixed with non-residential area soils at the AV Smelter site and 4 feet thick covered by 6 feet of non-residential area soils and the soil cover over 0.82 acres at the CZL Mill site.

Non Residential Area Soils - Soil Cover Over Consolidated Non-Residential Area Soils: 10.5 acres at an average thickness of 5 feet at the AV Smelter site and 6 feet thick over 0.82 acres at the CZL Mill site)

1.2 Help Modeling

The HELP model, Version 3.05 (Schroeder, et al., 1994), was used to simulate the water balance for the various scenarios. This program is designed to model water movement across, into, through, and out of landfills and impoundments by a quasi-two-dimensional approach. The following hydrologic processes are simulated as part of the hydrologic balance: surface storage, snowmelt, runoff, infiltration, evaporation, soil moisture storage, lateral subsurface drainage, and unsaturated vertical drainage. Overall, the objective for applying the HELP model to the AV/CZL alternatives was to estimate the rate of water movement through the existing materials or various covering scenarios, from the final surface to the top of the underlying alluvium.

Material input parameters for the cover system/material layers are shown in Table C-l. Material physical characteristics were developed from general information on non-residential area soils, coarse tailings, debris, ore, and flue dust, and were assumed to generally be a loamy sand textured material. Cover soils used for this analysis were assumed to have a loamy fine sand texture, similar to the cover soils proposed for use at the OU7 Apache Tailing Impoundments (MFG, 1999b). As necessary, field capacity and wilting point were assigned for each layer based on selection of a material with similar texture from the HELP model's listing of "Default Soil, Waste, and Geosynthetic Characteristics". Geomembrane performance characteristics were assigned, based on HELP model guidance, to reflect potential reductions in geomembrane effectiveness for minimizing seepage through the liner. A pinhole density of 1 per acre, installation defect density of 4 per acre, and "good" placement quality were assumed.

Daily temperature and precipitation data for Leadville (Colorado Climate Center, 1997) were used for the period from 1949 through 1995; years with incomplete data were eliminated, thus yielding a total of 34 years of record for the HELP simulation. The average annual precipitation for the simulation was 14.76

ASARCO Incorporated MFG, Inc. J:\BLDOI\5344\5344-JO\AV_CZL DcsignUniiltration Aiwlysis.doc 2 July 19, 2004 inches. Solar radiation data were synthetically generated based on Denver, Colorado parameters. Humidity data, collected from October 1990 to October 1991, were included, and the average annual wind speed was 10 miles per hour. Input parameters specific to Leadville included latitude (39.25 degrees) and growing season (79 days).

The evaporative zone depth was set at 18 inches, to be equivalent to the cover soil thickness. This thickness was determined to yield the most benefit, relative to investment in drought tolerance and minimization of percolation below the source material.

1.3 Results

The total estimated infiltration rate through flue dust under current conditions is 0.39 gallons per minute (gpm). Relocating the flue dust to a fully encapsulated lined repository is estimated to result in an infiltration rate through the flue dust of 0.000001 gpm (0.00022% of current conditions).

For tailing, current infiltration is estimated at 0.26 gpm. Consolidating and covering with soil is estimated to further reduce infiltration to 0.05 gpm (19% of current conditions).

For non-residential area soils, current infiltration is estimated at 7.56 gpm. Consolidating and covering with soil is estimated to further reduce infiltration to 0.46 gpm (6% of current conditions).

Table 1.1-1 HELP MODEL MATERIAL INPUT PARAMETERS

Field Wilting Ksat HELP Model Material Thickness Porosity Capacity Point (cm/sec) Default Settings Cover Soil 18 in 0.457 0.131 0.058 l.OxlO'3 Properties are for HELP soil #5 (loamy fine sand) Geomembrane 60 mil n.a.(1> n.a. n.a. 3.0 x lO'12 Properties are for HELP material #40 (CSPE) AV/CZL , 0.5 to 10 0.437 0.105 0.047 1.7xlO-3 FC and WP for HELP soil Material ft #4 (loamy sand) Compacted 15ft 0.419 0.307 0.180 1.9X10'5 FC and WP for HELP soil Material #22 (compacted loam)

(" Material porosity, field capacity, and wilting point not applicable (n.a.) for geomembrane materials.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZL DesignMnfiltradon Analyiii.doc July 19, 2004 Attachment 1.2

Erosion Calculations APPENDIX 1.2

1.0 EROSION ANALYSIS

This section presents the analysis of potential erosion from the soil covers on the AV Smelter and CZL Mill sites. Soil erosion by water is the process of soil loss from a given slope, usually predicted on a per unit area basis. The closure will be designed to meet the criterion for overall long-term erosion control of 2 tons per acre per year (U.S. EPA, 1985). Estimated average annual ' short-term and long-term erosion rates were estimated using the Universal Soil Loss Equation (USLE; Haan et al., 1994; Gray and Leiser, 1982). The USLE is an empirical equation, as follows:

A = RKLSCP

Where: A = average'soil loss per unit area per time period R = rainfall/runoff factor = 16 for this analysis K = soil credibility factor = 0.15 for this analysis L = slope length (see tables below for slope length) S = slope steepness factor (see tables below for slope angle) C = cover management factor (see tables below) P = supporting conservation practice factor = 1 for this analysis

Soil loss estimates were developed for short-term conditions to represent potential for erosion during the period of initial vegetation establishment. The short-term time period is the most critical for establishment of a plant cover. During this time, the plant community changes dramatically in both density and composition; these changes translate into varying cover conditions influencing erosion. In addition to short-term conditions, erosion under long-term conditions was estimated to represent a self-sustaining, permanent vegetative cover.

The final soil covers on the' AV Smelter and CZL Mill sites were subdivided into discrete areas for erosion estimation based on slope angle and slope length. For short- and long-term conditions all USLE variable were held constant except for the cover management factor, C, which was set at 0.24 for-short-term conditions and 0.042 for long-term conditions. The cover factor of 0.24 for short-term conditions assumes straw mulch without tackifier, which is the worst-case condition expected immediately after seeding. After several years of establishment a cover factor of 0.042, assuming 60 percent grass ground cover, would apply.

AV Smelter Site

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-50\AV_CZLDesipi\ErosionAnalysis.doc 1 December 1, 2003 Average Average Annual Soil Loss (tons/acre) Segment Slope Short Term Long-Term Length (ft) Conditions (C=0.24) Conditions (C=0.042) 1 Max Top Slope (3%) 550 0.3 0.0 2 Average Top Slope (3%) 350 0.1 0.0 3 Max 5:1 Slope 150 2.9 0.5 4 Average 5:1 Slope 125 2.6 0.5

CZL Mill Site Average Average Annual Soil Loss (tons/acre) Segment Slope Short Term Long-Term Length (ft) Conditions (C=0.24) Conditions (C=0.042) 1 2:1 90 9.8 1.7 2 3:1 E 60 4.0 0.7 3 3:1 W 60 4.0 0.7 4 3:1 S 30 2.9 0.5 5 4:1 160 4.3 0.8 6 5:1 110 2.4 0.4 7 10:1 80 0.8 0.1 8 20:1 100 0.2 0.0 9 3% 90 0.2 0.0

As shown on the above tables, slopes greater than 5:1 are most susceptible to short-term erosion. Therefore, additional erosion control materials such as erosion control blankets, jute or other biodegradable netting, should be installed immediately during seeding and related operations. Under long-term conditions, with the establishment of a vegetative cover, predicted annual average soil loss from these and all other slopes will be reduced to acceptable levels of less than 2 tons/acre.

ASARCO Incorporated MFC, Inc. J:\BLDOI\5344\5344-SO\AV_CZL Design\Erosion Analysis.doc December I, 2003 MFC, Inc.

Calculation/Computation Set Cover Sheet Review Documentation

^Preof Project: Job Number: Task: frtS/C&L. S;+-e* 0/OT3VY CT/ Title of Calculations: £o// Em*b* Ca.lcJ+b&i's Calcuations By: PorrtName ' , Date Si•LAc-n./'a. I C. . jL/eJcc^-tov^z r£x- fi^. 3/7/0 / Assumptions Checked By: Print Name Date (Senior Personnel) fre/6*k L. CL*Aef Si8Mture ~^06L- 3/H/oi Calculations Checked By: Print Name / Date

Signature —j , S, V/^/of 7M£^£^ The Reviewer's/Checker's comments have been discussed with the Reviewer/Checker, and all significant issues have been resolved. Calculation Originator: Print Name Date b , Signature Reviewer/Checker: Print Name Date'

Signature

Apprived By: Print Name Date (Principal Investigator or Project Manager: Signature

Reviewer/Checker Approval (Approval Notes: If calculation are only spot checked, do not require checking, or are assumed to be correct by experience or engineering judgement, it should be noted here.)

ion Number Date By. Checked By. Approval1. 1 Date By: Checked By: Approval: r 2 AV/CZL Site - Soil Erosion Calculations MFG Job #015344.51 Calc. Set by: D. Delahunty 3/08/01 Arkansas Valley Soil Cover Based on Calc. Set bv: F. Charles 10/26/00

USLE equation: A=RKLSCP All tables, figures, equations and appendix references are from, eicrpt as noted: Design Hydrology and Sedimentology for Small Catchments by Haan, Barfield, & Hayes, 1994 (Haan et al., 1994)

A = Avg. soil loss per acre Water Management (Jarrett, 1995) tons/acre/year R = Rainfall factor R = 16 average annual —> obtained from Figure 8A.1, Appendix 8A ft*tohsf in/acre (See Attachment A)

K = Soil credibility factor K «= obtained from Fig. 8.9 with check from Table 8.4 tons'acre'hr (See Attachments B and C) hundreds*acre*ft*tonsf*in using material properties for the borrow source (See Attachment D1-D7)

LS = Length-Slope factor LS = obtained from Figure 6-2 (Jarrett, 1995); (See Attachment E)

C •= Cover and management factor C - 0.18 Short term Tackified Straw Mulch @ 1 Ton/acre (applies for estab period = 1 yr) Table 8.8, (See Attachment F) C •» 0.042 Long term 0% canopy cover, 60% grass cover (After 1 year) Table 8B.2, Appendix B, (See Attachment G) C = 0.24 Short term straw mulch (no tackifier) @ 1 ton'acre [0.75 t/ac equiv] (estab period = 1 yr) Table 8.8, (See Attachment F)

P = Conservation practice factor P = 1 Assumes no contour tillage, terracing, etc.

Short- and Long-Term Estimated Erosion Rates , 1 Borrow Source Cover Soil (Attachment D) 2 K = 0.15 (as estimated using Fig. 8.9 [nomograph], see Attachment B. Nomograph value is lower than K values on Table 8.4, see Attachment C. The lowest K value (sand) from table 8.4 was used.) 3 Max slope length of Top Slope (3% slope) = 550 ft; LS = 0.48 (See Attachment E) Average slope length of Top Slope (3% slope) = 350 ft; LS = 0.42 (See Attachment E) Max slope length of 5:1 Slope = 150 ft; LS •= 5.0 (See Attachment E) Average slope length of 5:1 Slope = 125 ft; LS = 4.6 (See Attachment E) 4 C = 0.18 (Straw mulch @ 1 ton/ac, Table 8.8) (See Attachment F) — not used in this analysis C = 0.042 (0% canopy cover, 60% grass ground cover, Table 8B.2) (See Attachment G) C = 0.24 (Straw mulch, non-tackified @ 1 ton/ac [0.75 t/ac equiv], Table 8.8) (See Attachment F) 5 P •= 1 (no contour tillage, etc.)

A Cover Type R K LS C P Segment (tons/ac/yr) Max Top Slope (Short Term - Straw Mulch - no tackifier) 16 0.15 0.48 0.24 0.3 (3%) (Long Term - 60% Grass) 16 0.15 0.48 0.042 0.0 Average Top (Short Term - Straw Mulch - no tackifier) 16 0.15 0.12 0.24 O.I Slope (3%) (Long Term - 60% Grass) 16 0.15 0.42 0.042 0.0 Max (Short Term - Straw Mulch - no tackifier) 16 0.15 5 0.24 •T2.9 5:1 Slope (Long Term - 60% Grass) 16 0.15 5 0.042 0.5 Average (Short Term - Straw Mulch - no tackifier) 16 0.15 4.6 0.24 -- 2.6 5:1 Slope (Long Term - 60% Grass) , 16 0.15 4.6 0.042 0.5

If A < 2.0, OK If A > 2.0, long-term:.. not OK short term... some additional biodegradable controls/amendmentsAackiiiers should be added

J:\5344\5344-50\eroslon calc.xte, AV AV/CZL Site - Soil Erosion Calculations MFG Job #015344.51 Cale. Set by. D. Delahunty 3/08/01 Colorado Zinc/Lead Soil Cover Based on Calc. Set bv: F. Charles 10/26/00

FSLE equation: A=RKLSCP All tables, figures, equations and appendix references are from, eicept as noted: Design Hydrology and Sedlmentology for Small Catchments by Haan, Barfield, & Hayes, 1994 (Haan et aL, 1994)

A = Avg. soil loss per acre Water Management (Jarrett, 1995) tons/acrefyear R » Rainfall factor R = 16 average annual —> obtained from Figure 8A.1, Appendix 8A ft*ionsf*in/acre (See Attachment A)

K = Sofl' credibility factor K = obtained from Fig. 8.9 with check from Table 8.4 lons*acre*hr (See Attachments B and C) hundrcds*acre*fi*tonsf*in using material properties for the borrow source (See Attachment D1-D7)

LS = Length-Slope factor LS • obtained from Figure 6-2 (Janett, 1995); (See Attachment E)

C = Cover and management factor C «• 0.18 Short term Tackified Straw Mulch @ 1 Ton/acre (applies for eslab period - 1 yr) Table 8.8, (See Attachment F) C • 0.042 Long term 0% canopy cover, 60% grass cover (After 1 year) Table 8B.2, Appendix B, (See Attachment G) C " 0.24 Short term straw mulch (no lackifier) @ 1 (on/acre [0.75 t/ac equiv] (esub period = 1 yr) Table 8.8, (See Attachment F)

P • Conservation practice factor P ~ 1 Assumes no contour tillage, terracing, etc.

Short- and Long-Term Estimated Erosion Rates 1 Borrow Source Cover SoD (Attachment D) 2 K = 0.15 (as estimated using Fig. 8.9 [nomograph], see Attachment B. Nomograph value is lower than K values on Table 8.4,1 Attachment C. The lowest K value (sand) from table 8.4 was used.) 3 Average slope length of 2:1 slope = 90 ft; LS = 17.0 (See Attachment E) Average slope length of 3:1 E slope = 60 ft; LS = 7.0 (See Attachment E) Average slope -length of 3:1 W slope = 60 ft; LS = 7.0 (See Attachment E) Average slope length of 3:1 S slope = 30 ft; LS » 5.0 (See Attachment E) Average slope length of 4:1 slope " 160 ft; LS « 7.5 (See Attachment E) Average slope length of 5:1 slope = 110 ft; LS = 4.2 (See Attachment E) Average slope length of 10:1 slope » 80 ft; LS = 1.4 (See Attachment E) Average slope length of 20:1 slope = 100 ft; LS = 0.4 (See Attachment E) Average slope length of 3% slope - 90 ft; LS ° 0.28 (See Attachment E) 4 C = 0.18 (Straw mulch @ 1 ton/ac, Table 8.8) (See Attachment F) — not used in this analysis C = 0.042 (0% canopy cover, 60% grass ground cover, Table 8B.2) (See Attachment G) C = 0.24 (Straw mulch, non-tackified @ 1 ton/ac [0.75 t/ac equiv], Table 8.8) (See Attachment F) 5 P " 1 (no contour tillage, etc.)

A Cover Type R K LS C P Segment (tons/ac/yr) (Short Term - Straw Mulch - no tackifier) 16 0.15 17 0.24 9.8 1 2'1 —Due to the high erosion Long Term - 60% Grass) 16 0.15 17 0.042 1.7 rate on the 2:1 Slope, [Short Term • Straw Mulch • no tackifier) 0.15 7 0.24 4.0 additonal erosion control 2 3-1E 16 (Long Term - 60% Grass) 16 0.15 7 0.042 0.7 materials, such as jute or erosion man, should be 3 3>i y/ 'Short Term - Straw Mulch • no tackifier) 16 0.15 7 0.24 4.0 (Long Term - 60% Grass) ' 16 0.15 7 0.042 0.7 installed during 4 3.] s (Short Term - Straw Mulch - no tackifier) 16 0.15 5 0.24 2.9 re-vegetation operations. (Long Term - 60% Grass) 16 0.15 5 0.042 0.5 5 4*1 (Short Term - Straw Mulch - no tackifier) 16 0.15 7.5 0.24 43 (Long Term - 60% Grass) 16 0.15 7.5 0.042 0.8 (Short Term - Straw Mulch - no tackifier) 0.15 4.2 0.24 2.4 6 5'1 16 (Long Term - 60% Grass) 16 0.15 4.2 0.042 0.4 7 ]Q.| (Short Term - Straw Mulch - no tackifier) 16 0.15 1.4 0.24 0.8 (Long Term - 60% Grass) 16 0.15 1.4 0.042 0.1 B fn.1 (Short Term - Straw Mulch - no tackifier) 16 0.15 0.4 0.24 0.2 (Long Term - 60% Grass) 16 0.15 0.4 0.042 ~l 0.0 (Short Term - Straw Mulch - no tackifier) 16 0.15 0.28 0.24 0.2 9 3% (Long Term - 60% Grass) 16 0.15 0.28 0.042 0.0

If A < 2.0, OK If A > 2.0, long-term... not OK short term... some additional biodegradable controls/amendmcnts/tadcifiers should be added

J:\5344\5344-50\eroslon calcjds, CZL 530 Appendix 8A

Figure 8A.1 Isolines of 7? factor for Western U.S. (after Renard tt a/., 1993b). Units on fl are ft • tonsf • in./acre • hr • year. To convert to metric, MJ • mm/ha • h • year, multiply by 17.02. Rill and Interrill Erosion Modeling: USLE/RUSLE Empirical Models 255 slope of 9% with a slope length of 72.6 ft with up- and Wischmeier et al. (1971), which was developed from wnslope tillage. Under.these conditions, L, S, C, data collected on 55 midwestern agricultural soils. Soil 'd P are all equal to 1.0, hence credibility in the nomograph is predicted as a function of five soil and soil profile parameters: measured erosion K (8.35) . Percentage silt (MS; 0.002-0.05 mm). I El,30 . Percentage very fine sand (VFS; 0.05-0.1 mm). . Percentage sand (SA; 0.1-2 mm). Practically, one seldom encounters standard conditions . Percentage organic matter (OM). for a test; hence, data are taken under nonstahdard . Structure (5,). conditions, and corrections are made based on ac- . Permeability (P,). cepted relationships for L, S, C, and P. Inaccuracies in any of these other parameters would be reflected in the It is important to note that the size ranges given here estimated K values. are not standard for some particle classifications. Codes for structure and permeability are given in USDA soil Estimating K Factors for Average Annual Erosion survey manuals (Soil Conservation Service, 1983) avail- A number .of studies of soil credibility have been able for most counties in the U.S. and in some foreign made with the USLE/RUSLE format as summarized countries. The nomograph is shown in Fig. 8.9. by Romkens et al. (1993). In the USLE, K is assumed An analytical relationship for the nomograph in to be constant throughout the year. Tables of K values Fig. 8.9 is (Wischmeier et al., 1971) are available from local Soil Conservation Service of- 2.1 x 1Q-4(12 - OM)M'-'4 + 3.25(5, - 2) + 2-5(f, - 3) fices for most soils in the U.S. K values are also K" 100 ' tabulated in the more recent soil survey manuals. In (8.36) the absence of published data, a widely used relation-, ship for predicting credibility is a nomograph by where K is soil credibility in tons per acre per unit

PROCEDURE! With opproprlote data. enter ecale at left with X Silt -I- vfe (.002 - 0.1mm) and proceed to polnte representing the soli's X tond (0.10—2.0mm), X organic matter, structure, and permeability. In that sequence. Interpolate between plotted curvet. The dotted line Dluetrotes procedure (or a eoU having: sM-vfe 05X, sand 5X, OU •trueture 2. permeobBlly 4. Solution: r>0.31. .. «".•< or .04 t*no*hf , hundreds ae ho-MJ-mm Figure 8.9 Soil credibility nomograph of Wischmeier et al. (1971). The axes for K are scaled in both English and SI units. Rill and Interrlll Erosion Modeling: USLE/RUSLE Empirical Models 261 greater than 15 ft, the S factor from the USLE was data from disturbed lands with slopes up to 84%, modified significantly by McCool et al. (1987, 1993) Mclssac et al. (1987) developed an equation similar t after extensive evaluation of the original USLE data (8.39) and (8.40) with exponents in the same range;1 base. The modified version is thus McCool et al. (1993) recommend that Eqs. (8.39) , and (8.40) also be used for disturbed lands. S = 10.8 sin 0 + 0.03; sin 6 < 0.09 ' (8.39) For slope lengths less than 15 ft, the 5 factor is not 5 - 16.8 sin 0 - 0:50; sin 0 ;> 0.09, (8.40) as strongly related to slope (slope exponent less than 1.0) since rilling would not have been initiated. The where 8 is the slope angle. Based on an evaluation of recommended factor is = 3.0(sin0)°'8 + 0.56. (8.41) Table 8.4 K Value Estimates based on Textural Information (English Units) (Soil Conservation Service, 1978) Under conditions where thawing of recently tilled soils is occurring and surface runoff is the primary Texture Estimated K value" factor causing erosion (typical of the Pacific Northwest in the spring), the 5 factor should be (McCool et al., Topsoil 1987, 1993) Gay, clay loam, loam, silty clay Fine sandy loam, loamy very fine sand, sandy loam 5 = 4.25(sin0) sin 0 £ 0.09. (8.42) Loamy fine sand, loamy sand /Sand T^r thawing soils with slopes less than 9%, Eq. (8.39) Silt loam, lilty clay loam, very fine sandy loam should be used. The S factor in the RUSLE is significantly modified from the original USLE as a result of an extensive Subsoil and Residual Material reevaluation of the original data base, addition of the Outwash Soils factors for short slope lengths, and new values for Sand 0,17 thawing soils (McCool et al., 1987). The original data Loamy sand 0.24 base did not include values beyond 20%. When Sandy loam 0.43 the quadratic form of the equation for 5 developed Gravel, fine to moderate fine " 0.24 the original USLE, projections beyond 20% yielded Gravel, medium to moderate coarse 0.49 unreasonably high values for erosion. The RUSLE Ltcrustrine Soils equation with the linear function corrects this problem. Silt loam and very fine sandy loam 0.37 Slope Length Factor Silty clay loam 0.28 Gay and silty clay 0.28 . The slope length factor was developed by McCool et al. (1989, 1993) from the original USLE data base ClacialTSll augmented with theoretical considerations. The L fac- Loam, fine to moderate fine subsoil 0.32 tor retains its original form Loam, medium subsoil 0.37 .Clay loam 0.32 (8.43) Clay and silty clay 0.28 J72.f—e Loess 0.37 Residual where A is the slope length in feet, 72.6 ft is the length Sandstone 0.49 of a standard erosion plot, and m is a variable slope Siltstone, nonchannery 0.43 length exponent. Slope length, A, is the horizontal Siltstone, channery 032 projection of plot length, not the length measured along the slope. The difference in horizontal projec- Acid clay shale 0.28 tions and slope lengths becomes important on steeper Calcareous clay shale or limestone residuum 0.24 slopes. "These values are typical based only on texture! information. Values for The slope length exponent is related to the ratio of an actual soil can be considerably different due to different structure and rill to interrill erosion, 0 (Foster et al, 1977b; McCool infiltration. et al., 1989,1993), by *Unils on AT in this table are English units (tons'acre'hr/hundredv acre-fftoasf-in.). To convert to metric units (t-ha-h/ha-MJ-mm), multiply (8 44) lvalues by 0.1317. "-IT?" ' ACZ LABORATORIES, INC AamJyte* D»tt P*ciij«

INORGANIC ANALYSIS DATA SHECT

Can mec SDONec AST1«4 Date Received: 03/OW3 Mains SOIL Lab No.- 93-ASvOOOS

: LOW SAMPLE ID WCC-CLAY-3

ANALYTE CONC c UNITS'

pH, Saturated Paste 7JO onlts Conductivity, Saturated Paste 160 ontos/cn %S4n«lion 23 % Sodlun, Saturated P«te 022 • mtqIL Calo'um, Sanuated Paite 1JD1 meq/L Magnesium. Saturated Piste OJ9 meq/L Carbon, Orginic 700 mc/Ke Organic Matter OJ u % ^goeeo. Total KJeldaJa 0^31 u %uN IHA Soluble 0.1 U |NO3asN,mg/K* IFOTptoms, Eirractable 0.06 I5&P Potajsiun, DaraciaWe 48 mg/Kf Particle She AnaJysa Saad 80 * S3t 10 % Oay 10 % Tenure S (S«jandPSi=sih,C=clayJL«»Ioam)

• •= AH vahie* reported on s sofl dry wefebt bailj.

FORMI-IN GRAIN.SIZE DISTRIBUTION TEST REPORT s . • « . ~i ...„.££ 5 100 i ! I II

D PI DBS D50 10 23 8 41.21 7.16 2.32 0.596 0.1758 0.016S 2.99 431.5

MATERIAL DESCRIPTION uses AASHTO • SAND. VERY GRAVELLY. SLIGHTLY CLAYEY sw-sc

Project No.: 22909C-T1000 Remarks: Project: XO'HA GULCH/ASARCO • Location: -CLAY" SAMPLE bate: 2-26-93 GRAIN SIZE DISTRIBUTION TEST REPORT WOODWARD-CLYDE CONSULTANTS Figure No. 2 Length-Slope Factor, LS « * ' , » Slope length is defined as the distance from the point of origin'of overland flow to the point where the ^lope gradient decreases to the extent that deposition begins, or the point where runoff enters a well-defined channel, whichever is limiting for the major part of the area being considered. The slope length factor L and slope gradient factor S may be evaluated separately (see Wischmeier and Smith, 1965 for these formulae). More commonly, the L factor and the S factor are evaluated as the single LS factor. The LS factors are obtained from Figure 6-2 based on the slope length, in feet and the slope gradient, in percent. The LS factor can be evaluated when planning erosion control practices'because some conservation practices are designed to limit the slope length. Terraces are probably the best example of such a practice that limits the unrestricted flow length by subdividing a long slope into shorter lengths.

400 100 BOO* 1000

SLOPE LENGTH

FIGURE 6-2. Slope-Length Factors. (Adapted from ferae/sen etal., 1980).

109 Length-Slope Factor, LS

Slope length is defined as the distance from the point of origin of overland flow to the point where the slope gradient decreases to the extent that deposition begins, or the point where runoff enters a well-defined channel, whichever is limiting for the major part of the area being considered. The slope length factor L and slope gradient factor S may be evaluated separately (see Wischmeier and Smith, 1965 for these formulae). More commonly, the L factor and the S factor are evaluated as the single LS factor. The LS factors are obtained from Figure 6-2 based on the slope length, in feet and the slope gradient,'in percent. The LS factor can be evaluated when planning erosion control practices because some conservation practices are designed to limit the slope length. Terraces are probably the best example of such a practice that limits the unrestricted flow length by subdividing a long slope into shorter lengths.

20.0 : 3-&- £ I «JC P ~.-z => -- ^ H I" ?*• 10.0 — 1.0 - MX i = — - p- t.a - = M I ~tr ei - = p- ^*- ^— -

= T^ 2( L :* , • 4.0' — jj '- 4 •7= «H ~< - is I *f Oi - HX f= _^f~- _^ t * = ' ° 2.0 ^* u ~ ~ x — i = 1 a u ; l>X MT^ <*^. o r |( I»-* 10 |—- ' ^ - 0- O.B PT h- a - ( c Oi T i— . (3 O.C jf Ti — ' 1 y 4 £ • r~ •~ ^ ; SX - o)° m * SX *+. - - _ . — ~ *~\ j_ 2X - TT — T t 0.2 —T iL_ 1X = : + _ » K - _L - -«i ^ — • ^ S = • - - - — ^ — : --" i 0.GX O.I 3 ,, 3JJ ^rt 0 40 • Sa I» too ' r /S"6 2 10 '400 )0 8(X) I000 «? (ft ^t •<' ?' SL-DPI: LI:rIG TH (F EfIT )

FIGURE 6-2. Slope-Length Factors. (Adapted from Israelsen et ai, 1980).

109 266 8. Erosion and Sediment Yield

From Eq. (8.50b) Estimating Slope Lengths for Watersheds LS = 2/n •= 10.84/3-= 3.61. Slope length estimates for fields or watersheds with i. Summary. nonplanar surfaces require considerable professional judgment. A large number of slope lengths occur in Concave LS •= 3.61 any given real watershed. Erosion can be estimated for Uniform LS •= 4.33 each of these and area weighted to determine average Convex LS - 5.07. erosion on a watershed. Slope length is defined as the slope distance from Thus the convex shape has the highest LS factor. the point of origin of overland flow to the point of

Table 8.8 Selected USLE C Values for Construction, Mining, and Forest Lands,

Condition C factor i References Condition C factor -References

1. Bare soil conditions 5 . Undisturbed forest Undisturbed except scraped 0.66-1.30 100-75% canopy. 100-90% litter 0.0001-0.001 Compacted 35-20% canopy, 70-40% litter 0.003-0.009 Smooth • 1.00-1.40 6. Permanent pasture and brush cover Root raked * ' 0.90-1.20 0% canopy, 80% ground cover Disk tillage Grass 0.013 Fresh Weeds 0.043 After one rain Brush, 80% ground cover Mulch s 0.012 Straw hanicall7 y prepared woodland sites 05 tons/ac turned, 10% cover at ground 1.0 tons/ac Good soil 0.240 2.0 tons/ac Poor soil 0.360 4.0 tons/ac Burned, 0% cover at ground Wood chips Good soil 0.260 OS tons/ac 0.90 Poor soil 0.450 2.0 tons/ac 0.70 Disked, 0% cover at ground 4.0 tons/ac 0.42 Good soil 0.720 • 6.0 tons/ac 0.22 Poor soil 0.940 3. Chemical binders Asphalt emulsion, 605 gal/ac 0.14-0.52 az*t zC Aquatan, Terra-tack 0.67 4. Scedings No prepared seedbed New planting 0.64 After 60 days 0.54 Prepared seedbed New planting 0.40 After 60 days 0.05

Hole. Additional values are given in Appendix 8B. Transportation Research Board (1980). ' *Barfield«ra/.(1988). ^Wischmeier and Smith (1978). Afeyer et al. (1972). C factors for mulch vary depending on slope length and steepness. Slope length limits apply (see Appendix 8B, Table 8B.5). 550 Appendix 8B

Table 8B.2 C Factors for Permanent Pasture,, Rangeland, Idle Land, and Grazed Woodlands (after Wischmeier and Smith, 1978)a

Vegetal canopy Cover that contacts the surface Percentage ground cover Type and height of Canopy raised canopy* cover (%) Type" 0 20 40 60 80 95-100

No appreciable canopy G 0.45 1 ") 0.10 0.013 0.003 C°£°2 /lo^U W 0.45 0.24 0.15 0.090 0.043 0.011

Canopy of tall weeds or 25 G 0.36 0.17 0.09 0.038 0.012 0.003 short brush (0.5-m fall height) 1 W 0.36 0.20 0.13 0.082 0.041 0.011 50 G 0.26 0.13 0.07 0.035 0.012 0.003 W 0.26 0.16 0.11 0.075 0.039 0.011 75 G 0.17 0.10 0.06 0.031 0.011 0.003 W 0.17 0.12 0.09 0.067 0.038 0.011

Appreciable brush or bushes 25 G 0.40 0.18 0.09 0.040 0.013 0.003 (2-m fall height) ,.w 0.40 0.22 0.14 0.085 0.042 0.011 50 G 0.34 0.16 0.085 0.038 0.012 0.003 W 0.34 0.19 0.13 0.081 0.041 0.011 75 G 0.28 0.14 0.08 0.036 0.012 0.003 W 0.28 0.17 0.12 0.077 0.040 0.011

Trees, but no appreciable 25 G 0.42 0.19 0.10 0.041 0.013 0.003 low brush (4-m fall height) W 0.42 0.23 0.14 0.087 0.042 0.011 50 G 0.39 0.18 0.09 0.040 0.013 0.003 W 0.39 0.21 0.14 0.085 0.042 0.011 75 G 0.36 0.17 0.09 0.039 0.012 0.003 W 0.36 0.20 0.13 0.083 0.041 0.011

"All values shown assume: (1) random distribution of mulch or vegetation and (2) mulch of appreciable depth where it exists. Idle land refers to land with undisturbed profiles for at least a period of 3 consecutive years. Also to be used for burned forest land and forest land that has been harvested less than 3 years ago. * Average fall height of walerdrops from canopy to soil surface in meters. Tortion of total surface area that would be hidden from view by canopy in a vertical projection (a bird's-eye view). rfG, cover at surface is grass, grasslike plants, decaying compacted duff, or litter at least 2 in. deep. W, cover at surface is mostly broadleaf herbaceous plants (as weeds with little lateral root network near the surface) and/or undecayed residue. consulting scientists and CONSTRUCT CONTROL DITCH engineers

4900 Pearl East Crete. Suite Boulder. Colorado 80101 Phone (303) 447-1823 Fax (303) 447-1836

THE INFORMATION PROVIDED ON THS DRAWING WAS PRODUCED USING BOTH TECHNICAL INFORMATION AND KNOW HOW. ANT ADAPTATION OR MODIFICATION OF THE INFORMATION OR DRAWING SHALL BE AT THE USER'S SOLE RISK AND WITHOUT L1ABU1Y OR LEGAL EXPOSURE TO THE ENGINEER.

CONSTRUCT CONTROL

ASARCO Incorporated AV/CZL SfTE - OU5

REGRADING PLAN - AV SMELTER

DRAWING NO. 1534451C-106 z:

consulting . scientists and engineers

4900 Peart Eoat Circle. Soil* 300W. Boulder. Colorado BOM I Phone (303) 447-1823 Fax (303) 447-1836

DISCLAIMER THE INFORMATION PROVIDED ON THIS DRAWING WAS PRODUCED USING BOTH TECHNICAL WTORUATWN AND KNOW HOW. ANY ADAPTATION OR UOCHflCATION OF THE INFORMATION OR CHAWING SHALL BE AT THE USER'S SOLE RISK AND WITHOUT LIABILITY OR LEGAL EXPOSURE TO THE ENGINEER. REFERENCE

NO. REVISIONS BY DATE issue FOR REVIEW

APPROXIMATE LOCATION OF TAJUNG

APPROXIMATE LOCATION'OF NON-RESIDENTIAL SOIL

1 FT. ASSUMED AVERAGE MATERIAL DEPTH USED IN QUANTITY ESTIMATES

3ES1CNED BY; JRAWN BY; NOTES: CHECKED BY! APPROVED BY: 1. CONTRACTOR SHALL SUPPORT UTOJIY POLES F-CtVPCZ: CENOBC BW AS NECESSARY DURING CONSTRUCTION. VIEW NAME: PLAN ORIGINATION DATE: • 02/13/01 2. CONTRACTOR SHALL PROTECT TREES AND PLOT SCALE.- 1:1 OR SCRUBBED AS NECESSARY DURING -UARCH 2000 CONSTRUCTION. ASARCO Incorporated

N AV/CZL SfTE - OU5 EXCAVATION & REGRADIN6 PLAN - CZL MILL

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Supporting Calculations for Run-on/Run-off Control and Stormwater Management MFC, Inc. CALCULATION / COMPUTATION SET Cover Sheet Review Documentation

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Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL West Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.360000 Ml. M.

Results Depth 0.87 ft Flow Area 1.51 ft2 Wetted Perimeter 3.89 ft Top Width 3.48 ft Critical Depth 1.38 ft Critical Slope 0.030604 ft/ft Velocity 11.88 ft/s =^? "t> it- Velocity Head 2.19 ft Specific Energy 3.06 ft Froude Number 3.18 Flow is supercritical.

01/06/04 FlowMaster v5.12 02:25:50 PM Haestad Methods, Inc. 37 Brookside Road Waterbury. CT 06708 (203)755-1666 Page 1 of 1 Subject Project No. Task No. By _ Checked By File No. Date Date Sheet of

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Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL East Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.275000 ft/ft Left Side Slope 2.000000 H: V Right Side Slope 2.000000 H : V Discharge 6.00 cfs

Results Depth 0.61 ft Flow Area 0.74 ft2 Wetted Perimeter 2.71 ft Top Width 2.43 ft Critical Depth 0.89 ft Critical Slope 0.035431 ft/ft Velocity 8.16 "ft/8 ^ Velocity Head 1.04 ft Specific Energy 1.64 ft Froude Number 2.61 Flow is supercritical.

01/06/04 FlowMaster v5.12 02:33:19 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203)755-1666 Page 1 of 1 Subject Project No. Task No. . By Checked By File No. Date Date Sheet d> of

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HEAD FOR STANDARD CORRUGATED STEEL PIPE CULVERTS FLOWING FULL-OUTLET CONTROL n = 0.02-1

16. Outlet Control Nomograph for corrugated steel pipe culverts with sub- HEADWATER DEPTH FOR ged outlet and flowing full. - IZ CORRUGATED STEEL PIPE CULVERTS WITH INLET CONTROL Pipe Roughness Factor Length Adjustment factor Diameter . n' in Indict for Helical Corr. * (f)' 12 .011 .21 24 .010 .44 T& 36 .010 .01 48 .020 .70 •Other »»luc» of roughncM. n. ve applicable lo paved pipe, llnril plpt and plpr with Fig. IS. Inlet Control Nomograph (or corrugated tteet pipe culverts. 3 x I In. comifatloni. Srt pone 31. To u» the nbnvc clinrl for thrse lyiicj of pipe and pipe-arches. UM "•dluilcd lentlh factor*" computed per the equation, pne 2V.

-\ Culvert Calculator Report Existing at CZL

Solve For: Headwater Elevation

Culvert Summary Allowable HW Elevation 5.00 ft Headwater Depth/Height 1.19 Computed Headwater Elevi 4.37 ft Discharge 13.00 cfs -c. Inlet Control HW Elev. 4.08 ft Tailwater Elevation . 2.00 ft Outlet Control HW Elev. 4.37 ft Control Type Entrance Control

Grades Upstream Invert 2.00 ft Downstream Invert 0.00 ft Length 16.00 ft Constructed Slope 0.125000 ft/ft

Hydraulic Profile Profile Composites 1S2 Depth, Downstream 2.00 ft Slope Type Steep Normal Depth 0.75 ft Flow Regime N/A Critical Depth 1.30 ft Velocity Downstream 4.14 ft/s Critical Slope 0.019779 ft/ft

1

Section Section Shape Circular , Mannings Coefficient 0.024 Section Material CMP Span 2.00 ft Section Size 24 inch Rise 2.00 ft Number Sections 1

Outlet Control Properties Outlet Control HW Elev. 4.37 ft Upstream Velocity Head 0.56 ft Ke 0.90 Entrance Loss 0.51 ft

Inlet Control Properties Inlet Control HW Elev. 4.08 ft Flow Control Unsubmerged Inlet Type Projecting Area Full 3.1 ft1 K 0.03400 HDSSChart 2 M 1 .50000 HDS 5 Scale 3 C 0.05530 •Equation Form 1 Y 0.54000

Project Engineer Gus Steppen c:\haestadl\cvm\avczl.cvm MFC, Inc. CulvertMaster v2.0 [2.005] 12/01/03 01:25:50PM ©Haestad Methods. Inc. 37 Brookside Road Waterbury, CT 06708 USA + 1-203-755-1666 Page 1 of 1 Rating Table Report Existing at CZL

Range Data: Minimum Maximum Increment Discharge 0.00 26.00 2.60 cfs lischarge (cf: HW Elev. (ft) 0.00 2.00 2.60 2.94 5.20 3.38 7.80 3.73 10.40 4.06 13.00 4.37 15.60 4.68 18.20 4.99' 20.80 5.38 23.40 6.02 26.00 6.74

Project Engineer: Gus Steppen c:\haestad1\cvm\avczl.cvm MFC, Inc. CulvertMaster v2.0 [2.005] 12/01/03 01:26:10 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA * 1-203-755-1666 Page 1 Of 1 Subject Project No. Task No. By Checked By File No. Date Date Sheet \° of .

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Solve For: Discharge

Culvert Summary Allowable HW Elevation 8.00 ft Headwater Depth/Height 1.33 Computed Headwater Elevs 8.00 ft Discharge 54.91 cfs Inlet Contro'l HW Elev. 8.00 ft Tailwater Elevation 3.00 ft Outlet Control HW Elev. 7.93 ft Control Type Inlet Control

• Grades Upstream Invert 4.00 ft Downstream Invert 0.00 ft Length 200.00 ft Constructed Slope 0.020000 ft/ft

Hydraulic Profile Profile CompositeS1S2 Depth, Downstream 1.60 ft Slope Type Steep Normal Depth 1.57 ft Flow Regime N/A Critical Depth 2.41 ft Velocity Downstream 14.31 ft/s Critical Slope 0.006018 ft/ft

Section Section Shape Circular Mannings Coefficient 0.012 SecGtDTnVtjiteiiHDPE (Smooth Interior) Span 3.00 ft Section Size 36 inch Rise 3.00 ft Number Sections 1

Outlet Control Properties Outlet Control HW Elev. 7.93 ft Upstream Velocity Head 1.27 ft Ke 0.20 Entrance Loss 0.25 ft

Inlet Control Properties Inlet Control HW Elev. 8.00 ft Flow Control Submerged Inlet Type Beveled ring, 45° bevels' Area Full 7.1 ft1 K 0.00180 HDSSChart 3 M 2.50000 HDS 5 Scale A C 0.03000 Equation Form 1 Y 0.74000

Project Engineer: Gus Steppen unfilled.cvm MFC, Inc. CulvertMaster v2.0 [2.005] 12/01/03 10:06:01 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Rating Table Report Worksheet-2

Range Data: Minimum Maximum Increment Discharge 0.00 100.00 10.00 cfs

>ischarge (cf: >HW Elev. (ft) 0.00 4.00 10.00 5.44 20.00 6.10 30.00 6.66 40.00 7.17 50.00 7.69 60.00 8.35 70.00 9.13 80.00 10.03 90.00 11.05 100.00 12.19

Project Engineer: Gus Steppen unfilled.cvm MFC, Inc. CulvertMaster vZ.O [2.005] 12/01/03 10:06:39 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Culvert Calculator Report Worksheet-2

Solve For: Section Size

Culvert Summary Allowable HW Elevation 8.00 ft Headwater Depth/Height 1.41 Computed Headwater Elev; 7.53 ft Discharge 37.00 cfs Inlet Control HWEIev. 7.53 ft Tailwater Elevation 3.00 ft Outlet Control HW Elev. 7.42 ft Control Type Inlet Control

Grades Upstream Invert 4.00 ft Downstream Invert 0.00 ft Length 200.00 ft Constructed Slope 0.020000 ft/ft

Hydraulic Profile Profile CompositePressureProfileSI S2 Depth. Downstream 1.39 ft Slope Type N/A Normal Depth 1.38 ft Flow Regime N/A Critical Depth 2.06 ft Velocity Downstream 13.19 ft/s Critical Slope 0.006869 ft/ft

Section Section Shape Circular 1 Mannings Coefficient 0.012 SecGJrrrrt/tfdteiiHDPE (Smooth Interior) Span . 2.50 ft Section Size 30 inch Rise 2.50 ft Number Sections 1

Outlet Control Properties Outlet Control HW Elev. 7.42 ft Upstream Velocity Head 1.14 ft Ke 0.20 Entrance Loss 0.23 ft

Inlet Control Properties Inlet Control HW Elev. 7.53 ft Flow Control Submerged Inlet Type Beveled ring, 45° bevels' Area Full 4.9 ft1 K 0.00160 HDS 5 Chart 3 M 2.50000 HDS 5 Scale A C 0.03000 Equation Form 1 Y 0.74000

Project Engineer: Gus Steppen untitled.cvm MFC, Inc. CulvertMaster v2.0 [2.005] 12/01/03 10:41:19 AM © Haestad Methods, Inc. .37 Brookside Road Waterbury. CT 06708 USA i-1-203-755-1666 Page 1 of 1 Culvert Calculator Report Worksheet-2

Solve For: Discharge

Culvert Summary Allowable HW Elevation 8.00 ft Headwater Depth/Height 1.33 Computed Headwater Elev< 8.00 ft Discharge 42.70 cfs Inlet Control HW Elev. 7.44 ft Tailwater Elevation 3.00 ft Outlet Control HW Elev. 8.00 ft Control Type Entrance Control

, Grades Upstream Invert 4.00 ft Downstream Invert 0.00 ft Length 200.00 ft Constructed Slope 0.020000 ft/ft

Hydraulic Profile .Profile CompositeS1S2 Depth, Downstream 3.00 ft Slope Type Steep Normal Depth 1.35 ft Flow Regime N/A Critical Depth 2.13 ft Velocity Downstream 6.04 ft/s Critical Slope 0.004810 ft/ft

Section Section Shape Circular . Mannings Coefficient 0.012 SecGturrMjateiiiHDPE (Smooth Interior) Span 3.00 ft Section Size 36 inch Rise 3.00 ft Number Sections 1

Outlet Control Properties Outlet Control HW Elev. 8.00 ft Upstream Velocity Head 0.98 ft Ke 0.90 Entrance Loss 0.89 ft

Inlet Control Properties Inlet Control HW Elev. 7.44 ft Flow Control Unsubmerged Area Full 7.1 ft' K 0.00980 HDSSChart 1 M 2.00000 HDS 5 Scale 1 C 0.03980 Equation Form 1 Y 0.67000

Project Engineer: Gus Steppen c:\haestad1\cvm\avczl.cvm MFG. Inc. CulvertMaster v2.0 [2.005] 12/01/03 11:00:55 AM © Haestad Methods. Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Rating Table Report Worksheet-2

Range Data: Minimum Maximum Increment Discharge 0.00 90.00 10.00 cfs

>ischarge (cfs)HW Elev. (ft) 0.00 4.00 10.00 5.69 20.00 6.49 30.00 7.18 40.00 7.82 50.00 8.48 60.00 9.18 70.00 9.96 80.00 11.08 90.00 12.43

Project Engineer: Gus Steppen c:\haestad1\cvm\avczl.cvm MFC, Inc. CulvertMaster v2.0 [2.005] 12/01/03 11:01:27 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury. CT 06708 USA H -203-755-1666 Page 1 of 1 \ 99.7 120 Ch. 3 Watershed Characteristics

however, given the relatively small drainage areas used in calibrating the models, the coefficients probably reflect significant portions of overland flow travel time. The SCS Lag Formula. The Soil Conservation Service (SCS) provided an equa- tion for estimating the watershed lag, which was defined as the time in hours from the center of mass of the excess rainfall to the peak discharge; they also indicate that the time of concentration equals 1.67 times the lag. Equation 3-39 is intended for use on watersheds where overland flow dominates and was developed for nonurban watersheds. The SCS recommends that the lag equation be used for homogeneous watersheds 2000 acres and less. Two graphs were provided by SCS in TR-55 (1975) for correcting the lag formula for use in urban areas. One factor is based on the percentage of imperviousness and curve number.and the other on the percentage of the hydraulic length modified and the curve number. The method primarily reflects overland flow. The runoff curve number CN can be obtained from Table 7-6. Velocity Methods. The velocity methods are based on the concept that the travel time (7",) is a function of the length of flow (L) and the velocity (K): T, = £ (3-42)

in which T,, L, and V have units of .seconds, feet, and ft/sec, respectively. The travel time is computed for the principal flow path. Where the principal flow path consists of segments that have different slopes or land cover, the principal flow path should be divided into segments and Eq. 3-42 used for each flow segment. The time of con- centration is then the sum of thejravel times:

'«=£/.< = £7 (3-43) in which k is the number of segments and the subscript i refers to the flow segment. The velocity of Eq. 3-42 is a function of the type of flow (overland, sheet, rill and gully flow, channel flow, pipe flow), the roughness of the flow path, and the slope of the flow path. Some methods also include a rainfall index such as the 2-year, 24-hr rainfall depth. Flow velocities in pipes and open channels can be computed using Manning's equation:

1 49 2 3 3 V = — R h' S°- (3-44)

in which V is the velocity (ft/sec), n is the roughness coefficient, Rh is the hydraulic radius (feet), and S is the slope (ft/ft). A number of methods have been developed for estimating the velocity. Overland flow or sheet flow can be estimated using a relation- ship between the velocity and the slope: V = kS°-s (3-45) in which V is the velocity (ft/sec) and S is the slope (percent). The value of k is a function of the land cover, with values for five land covers (forest, trash fallow, short grass pasture, cultivated, and nearly bare) given in Table 3-12. These are also shown in Fig. 3-13. Sec. 3.9 Time Parameters 121

TABLE 3-12 Coefficients of velocity versus slope relationship for estimating travel times with the velocity method

k Land Use/Flow Regime

0.25 Forest with heavy ground litter, hay meadow (overlow flow) 0.50 Trash fallow or minimum tillage cultivation; contour or strip cropped; woodland (overland flow) 0.70 Short grass pasture (overland flow) 0.90 Cultivated straight row (overland flow) 1.00 Nearly bare and unfilled (overland flow); alluvial fans in western mountain regions 1.50 Grassed waterway 2.00 Paved area (sheet flow); small upland gullies

0.5 0.2 0.3 0.4 0.5 0.7 0.91.0 3 4 56789 10 20 30

Fig. 3-13 Velocities for upland method of estimating T0. 21-78 Jw er Engineering

Quantilf a $ type of data available refer to the length, detail, and completeness of the hydrologic records/wi ch may be either precipitation or stream flow. An example of the variation of detail in the final result may be found in the determination of flood runoff. Several methods yield only peak discharge, while others give the complete hydrograph. Accuracy is limited by cost and by assumptions made in the development of a method. The methods that follow provide a convenient means for solving typical runoff problems fi: encountered in water engineering. One method pertains to minor hydraulic structures, and a th second, to major hydraulic structures. A minor structure is one of low cost and of relatively minor importance and presents small downstream damage potential. Typical examples are small highway and railroad culverts and low-capacity storm drains. Major hydraulic structures are characterized by their high cost, great importance, and large downstream damage potential. ri Typical examples of major hydraulic structures are large reservoirs, deep culverts under vital i' highways and railways, and high-capacity storm drains and flood-control channels. Method for Determining Runoff for Minor Hydraulic Structures, The commonest means for determining runoff for minor hydraulic structures is the rational formula Q = CIA (21-127) where Q = peak discharge, cfs C = runoff coefficient, = percentage of rain that appears as direct runoff / = rainfall intensity, in. per hr A = drainage area, acres The assumptions inherent in the rational formula are: 1. The maximum rate of runoff for a particular rainfall intensity occurs if the duration of rainfall is equal to or greater than the time of concentration. The time of concentration is commonly defined as the time required for water to flow from the most distant point of a drainage basin to the point of flow measurement. 2. The maximum rate of runofffrom a specific rainfall intensity whose duration is equal to or greater than the time of concentration is directly proportional to the rainfall intensity.

Table 21-16. Common Runoff Coefficient!

Type of Drainage Area Runoff Coefficient C

Business: Downtown areas 0.70-0.95 Neighborhood areas O.SO-0.70 Residential: Single-family areas 0.30-0.50 Multi-units, detached 0.40-0.60 Multi-units, attached 0.60-0.75 Suburban 0.25-0.40 Apartment dwelling areas 0.50-0.70 Industrial: Light areas 0.50-0.80} Heavy areas 0.60-0.90 f Parks, cemeteries 0.10-0. 25 J Playgrounds 0.20-0.35 ^ Railroad-yard areas 0.20-0.40 7 Unimproved areas 0.10-0.30 \ Streets: Asphaltfc 0.70-0.95 Concrete 0.80-0.95 Brick 0.70-0.85 Drives and walks 0.75-0.85 Roofs 0.75-0.95 . Lawns: Sandy soil, flat, 2% 0.05-0.10^ Sandy soil, avg. 2-7* 0.10-0.15 ] Sandy soil, steep, 7% 0.15-0.20 1 Heavy soil, flat, 2* ' 0.13-0.17 / Heavy soil, avg, 2-7% 0.18-0.22 \ Heavy soil, steep, 7* 0.25-0.35 J

Worksheet Worksheet for Triangular Channel

Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV West Flow Element Triangular Channel Method Manning's Formula' Solve For Channel Depth

Input Data Mannings Coefficient 0.030 Channel Slope 0.020000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge 16.00 cfs"

Results Depth 1,,29 ft • Flow Area 3.30 ft2 Wetted Perimeter 5.75 ft Top Width 5,,14 ft Critical Depth 1..32 ft Critical Slope 0.0 17487 ft/ft Velocity 4..84 ft/8 Velocity Head 0.,36 ft Specific Energy 1..65 ft Froude Number 1.,06 Flow is supercritical.

11/24/03 FlowMaster vS.12 10:51:46 AM Haestad Methods. Inc. 37 Brooksirl* Rnarl orh,. r>, r-r nc-rno Worksheet Worksheet for Triangular Channel

Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV West Flow Element Triangular Channel Method . Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.030 Channel Slope 0.040000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000H:V Discharge 16.00 cfs

Results Depth 1.13 ft Flow Area 2.55 ft2 Wetted Perimeter 5.05 ft Top Width 4.51 ft Critical Depth 1.32 •n, Critical Slope 0.017487 ft/ft Velocity 6.28 fl/s Velocity Head 0.61 ft Specific Energy 1.74 ft Froude Number 1.47 Flow is supercritical.

11/24/03 FlowMaster v5.12 10:51:38 AM Haestad Methods. Inc. 37 Brookside Road Waterbury. CT 06708 (203)755-1666 Pace 1 of 1 Worksheet Worksheet for Triangular Channel

Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV West Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.030 Channel Slope 0.0 10000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge 16.00 cfs

Results Depth 1.46 ft Flow Area 4.28 ft2 Wetted Perimeter 6.55 ft Top Width 5.85 ft Critical Depth 1.32 ft Critical Slope 0.01 7488 ft/ft Velocity 3.73 ft/s Velocity Head 0.22 ft Specific Energy 1.68 ft Froude Number 0.77 Flow is subcritical.

11/24/03 FlowMaster v5.12 10:51:12 AM Haestad Methods, Inc. 37 Brookside Road Waterburv. CT 06708 (203\ 755-1666 Pana 1 rtf 1 Worksheet Worksheet for Triangular Channel

Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV East Flow Element Triangular Channel • Method Manning's Formula Solve For Channel Depth •

Input Data Mannings Coefficient 0.030 Channel Slope 0.018000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H: V Discharge 21.00 cfs

Results Depth 1.45 ft Flow Area 4.21 ft2 Wetted Perimeter 6.49 ft Top Width 5.81 ft Critical Depth 1.47 ft Critical Slope 0.01 6864 ft/ft Velocity 4.98 ft/s Velocity Head 0.39 ft Specific Energy 1.84 ft Froude Number 1.03 Flow is supercritical.

11/24/03 FlowMaster v5.12 11:24.03 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203)755-1666 Pano 1 nf 1 Worksheet Worksheet for Triangular Channel

Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV East Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.030 Channel Slope 0.027000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H:V Discharge 21.00 cfs "

Results Depth 1.35 ft Flow Area 3.62 ft2 Wetted Perimeter 6.02 ft Top Width 5.38 ft Critical Depth 1.47 ft Critical Slope 0.016865 ft/ft Velocity 5.80 ft/s Velocity Head 0.52 ft Specific Energy 1.87 ft Froude Number 1.25 Flow is supercritical.

12/09/03 FlowMaster v5.12 11:15:27 AM Haestad Methods. Inc. 37 Brooksirip Rnart Watorhnn, rrn«7nB Worksheet Worksheet for Triangular Channel

Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV East Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.040 , Channel Slope 0.1 20000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge 21.00 cfs

Results Depth 1.13 ft Flow Area 2.57 ft2 Wetted Perimeter 5.07 ft . Top Width 4.53 ft Critical Depth 1.47 .ft Critical Slope 0.029982 ft/ft Velocity 8.18 ft/s Velocity Head 1.04 ft Specific Energy 2.17 ft Froude Number 1.92 Flow is supercritical.

11/24/03 FlowMaster v5.12 11:24:32 AM Haestad Methods. Inc. 37 Brookside Road Waterbury, CT 06708 (203)755-1666 Page 1 of i Worksheet Worksheet for Triangular Channel

Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet AV East Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.030 Channel Slope 0.020000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge . 21.00 cfs

Results Depth 1.42 ft Flow Area 4.05 ft2 Wetted Perimeter 6.37 ft Top Width 5.69 ft Critical Depth 1.47 ft Critical Slope 0.0 16865 ft/ft Velocity 5.18 ft/s Velocity Head 0.42 ft Specific Energy 1.84 ft Froude Number 1.08 Flow is supercritical.

11/24/03 FlowMaster vS.12 11:23:50 AM Haestad Methods, Inc. 37 Brookside Road Waterburv r.T nfi7nn or\\\ T^. Worksheet Worksheet for Triangular Channel

Project Description . Project File j:\bld0 1 \programs\haested\fmw\avczl.fm2 Worksheet CZLWest Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.200000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000H:V Discharge 18.00 cfs

Results Depth 0.97 ft Flow Area 1.89 ft2 Wetted Perimeter 4.35 ft Top Width 3.89 ft Critical Depth 1.38 ft Critical Slope 0.030604 ft/ft Velocity 9.53 ft/s ' Velocity Head 1.41 ft Specific Energy 2.38 ft Froude Number 2.41 Flow is supercritical.

12/09/03 FlowMaster vS.12 11:06:45 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Pano 1 of 1 Worksheet Worksheet for Triangular Channel

Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL West Flow Element Triangular Channel Method Manning's Formula " Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.114000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge 18.00 cfs "

Results Depth 1.08 ft Flow Area 2.33 ft1 Wetted Perimeter 4.83 ft Top Width 4.32 ft Critical Depth 1.38 ft Critical Slope 0.030605 ft/ft Velocity 7.72 ft/s Velocity Head 0.93 ft Specific Energy 2.01 ft Froude Number 1.85 Flow is supercritical.

12/09/03 FlowMaster v5.12 11:06:29 AM Haestad Methods. Inc. 37 Brookside Road Waterburv. CT 0670B Worksheet Worksheet for Triangular Channel

Project Description Project File j:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL West Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.1 00000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope ' 2.000000 H : V Discharge 18.00 cfs

Results Depth 1.11 ft Flow Area 2.45 ft1 Wetted Perimeter ' 4.95 ft Top Width 4.43 ft Critical Depth 1.38 ft Critical Slope 0.030605 ft/ft Velocity 7.35 ft/s Velocity Head 0.84 ft Specific Energy 1.95 ft Froude Number 1.74 Flow is supercritical.

12/09/03 FlowMaster v5.12 11:08:48 AM Haestad Methods, Inc. 37 Brookside Road Waterbury. CT 06708 (203) 755-1666 Pace 1 of 1 Worksheet Worksheet for Triangular Channel

Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL West Flow Element Triangular Channel Method Manning's Formula' Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.033000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge 18.00 cfs"

Results Depth 1.36 ft Flow Area 3.71 ft2 Wetted Perimeter 6.09 ft Top Width 5.45 ft Critical Depth 1.38 ft Critical Slope 0.030604 ft/ft Velocity 4.85 ft/s Velocity Head 0.37 ft Specific Energy 1.73 ft Froude Number 1.04 Flow is supercritical.

12/09/03 FlowMaster vS.12 11:07:16 AM Haestad Methods, Inc. 37 Brookside Road Walerburv PT nR70R Worksheet Worksheet for Triangular Channel

Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL East Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.030 Channel Slope 0.01 0000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V * Discharge 6.00 cfs

Results Depth 1.01 ft Flow Area 2.05 ft2 Wetted Perimeter 4.53 ft Top Width 4.05 ft Critical Depth 0.89 ft, Critical Slope 0.019931 ft/ft Velocity 2.92 ft/s Velocity Head 0.13 ft Specific Energy 1.15 ft Froude Number 0.72 Flow is subcritical.

12/09/03 Flow/Master v5.12 10:28:16 AM Haestad Methods, Inc. 37 Brookside Road Waterbury. CT 06708 (203) 755-1666 Page 1 of 1 Worksheet Worksheet for Triangular Channel

Project Description Project File J:\bld01\programs\haested\fmw\avczl.fm2 Worksheet CZL East Flow Element Triangular Channel Method Manning's Formula Solve For Channel Depth

Input Data Mannings Coefficient 0.040 Channel Slope 0.1 33000 ft/ft Left Side Slope 2.000000 H : V Right Side Slope 2.000000 H : V Discharge 6.00 cfs

• Results Depth 0.69 ft Flow Area 0.97 ft2 Wetted Perimeter 3.11 ft Top Width 2.78 ft Critical Depth 0.89 ft Critical Slope 0.035433 ft/ft Velocity 6.21 ft/s Velocity Head 0.60 ft Specific Energy 1.30 ft Froude Number 1.86 Flow is supercritical.

12/09/03 FlowMaster v5.12 10:30:00 AM Haestad Methods. Inc. 37 Brookside Road Waterburv. CT 06708 (2031 755-166R D^nio t ft 1 12:1 OR BOTTOM

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" EQUIVALENT SPHERICAL DIAMETER, in ft FIGURE 6.12.- Rock Size for the Bureau of Public Roads Design (Simons and Senturk 1977}

sg B specific gravity of stone 4 = angle of pavement with the horizontal. According to Simons and Senturk (1977), the stone weight, W, is the median stone weight. The ASCE manual suggests that the velocity used is usually the • velocity at a distance of 10 ft from the bank. The above equation is essen- tially the same as that used by the California Highway Department.