Final Construction Quality Control Plan Lord Brook Source Areas Phase 2 .

Construction Quality Control Plan Table of Contents vii CONSTRUCTION QUALITY CONTROL PLAN LORD BROOK SOURCE AREAS PHASE 2 REMEDIAL ACTION ELIZABETH MINE SUPERFUND SITE SOUTH STRAFFORD, VERMONT TABLE OF CONTENTS Description 9.25.1 General 9.25.2 Material Approval 9.25.2.1 Low Permeability Soil 9.25.2.2 Non-woven Geotextile Fabric 9.25.2.3 Common Borrow 9.25.2.4 Wetland Topsoil 9.25.3 Construction Approval 9.25.3.1 Low Permeability Soil 9.25.3.2 Non-woven Geotextile Fabric 9.25.3.3 Common Borrow 9.25.3.4 Wetland Topsoil 9.25.4 Verification 9.26 Stabilization of Cover System in SOC 9.26.1 General 9.26.2 Material Approval 9.26.2.1 Seed Mixture 9.26.2.2 Type I riprap size B (non-limestone) 9.26.3 Construction Approval 9.26.3.1 Application of Seed Mixture 9.26.3.2 Maintenance of Seeded Topsoil Layer 9.26.3.3 Type I riprap size B (non-limestone) 9.26.4 Verification 9.27 SOC Landscaping and Wetlands Plantings 9.27.1 General 9.27.2 Material Approval 9.27.2.1 Wetland Plantings 9.27.3 Construction Approval 9.27.3.1 Plantings 9.27.4 Large Woody Debris 9.27.4.1 Maintenance of Plantings 9.27.5 Verification 9.28 SOC Access Road Modifications and Diversion Ditches 9.28.1 General 9.28.2 Material Approval 9.28.2.1 Topsoil for C-12 9.28.2.2 Wetland Seed Mix 9.28.2.3 Non-woven geotextile fabric (Type II) 9.28.2.4 24-inch Culvert Pipe and bedding 9.28.2.5 Type I riprap size A (non-limestone) 9.28.2.6 Type I riprap size B (non-limestone) 9.28.2.7 Type II riprap size A (limestone) 9.28.2.8 Common Borrow 9.28.2.9 Gravel 9.28.3 Construction Approval Section USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 Page No. 44 45 45 45 45 45 45 45 45 46 46 46 46 46 46 46 46 46 47 47 47 47 47 47 47 48 48 48 48 48 48 49 49 49 49 49 49 49 49 49 50 50 50 50 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan Table of Contents viii CONSTRUCTION QUALITY CONTROL PLAN LORD BROOK SOURCE AREAS PHASE 2 REMEDIAL ACTION ELIZABETH MINE SUPERFUND SITE SOUTH STRAFFORD, VERMONT TABLE OF CONTENTS Description Page No. 9.28.3.1 Topsoil for Vegetated Swales 50 9.28.3.2 Application of Erosion Control Fabric and Mulching of Vegetated Swales 50 9.28.3.3 Construction of Level Spreader 50 9.28.3.4 Seeding 50 9.28.3.5 Non-woven geotextile fabric (Type II) 50 9.28.3.6 24-inch Culvert Pipe, bedding and cover 51 9.28.3.7 Type I riprap size A (non-limestone) 51 9.28.3.8 Type I riprap size B (non-limestone) 51 9.28.3.9 Common Borrow 51 9.28.3.10 Gravel 51 9.28.4 Verification 51 9.29 Construct Clean Soil Cover System (East/West of SOC and in SOC HW) 52 9.29.1 General 52 9.29.2 Material Approval 52 9.29.2.1 Ground Agricultural Limestone 52 9.29.2.2 Low Permeability Soil 52 9.29.2.3 Common Borrow 52 9.29.2.4 Wetland Topsoil 52 9.29.2.5 Seed Mixture 52 9.29.3 Construction Approval 53 9.29.3.1 Special Inspection of Exposed Bedrock 53 9.29.3.2 Ground Agricultural Limestone 53 9.29.3.3 Low Permeability Soil/Common Borrow 53 9.29.3.4 Wetland Topsoil 53 9.29.3.5 Application of Seed Mixture 53 9.29.3.6 Maintenance of Seeded Topsoil Layer 54 9.29.4 Verification 54 9.30 Perform As-Built Survey 54 9.30.1 General 54 9.30.2 Material Approval 54 9.30.3 Construction Approval 54 9.30.4 Verification 55 9.31 Re-establish Property Lines 55 Section 10.0 FIELD CHANGE DOCUMENTATION 10.1 General 10.2 Field Changes Notices 55 55 55 11.0 PROJECT COMPLETION AND TURNOVER 11.1 Testing of Completed Systems 11.2 Punch-Out 11.3 Pre-Final and Final Inspections 11.4 Complete As-Built Drawings 11.5 Operations and Maintenance Manuals 56 56 56 56 56 56 USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan Table of Contents ix CONSTRUCTION QUALITY CONTROL PLAN LORD BROOK SOURCE AREAS PHASE 2 REMEDIAL ACTION ELIZABETH MINE SUPERFUND SITE SOUTH STRAFFORD, VERMONT TABLE OF CONTENTS Section Description 11.6 Instruction and Training Procedures 11.7 Materials Turnover 11.8 Warranty Page No. 56 57 57 LIST OF TABLES Table 5-1 Table 5-2 Definable Features of Work Summary of Quality Control Inspection & Testing Requirements LIST OF CHARTS Chart 2-1 Construction Quality Control Plan Organization Chart LIST OF APPENDICES Appendix A General Quality Control Report Forms (6) Appendix B Field Change Documentation Forms (2) USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan Page 1 CONSTRUCTION QUALITY CONTROL PLAN LORD BROOK SOURCE AREAS PHASE 2 REMEDIAL ACTION ELIZABETH MINE SUPERFUND SITE SOUTH STRAFFORD, VERMONT 1.0 PLAN IDENTIFICATION AND APPROVALS Project Title: Lord Brook Source Areas Phase 2 Remedial Action Elizabeth Mine Superfund Site Project Location: South Strafford, Vermont Contract No.: W912WJ18D0001 Task Order No.: W912WJ18F0025 Nobis Project No.: 94501.00 Prepared By: Adam Morse, Brett Kay Submittal Date: 04/27/2018 Revision No.: 01 APPROVALS: J. Christopher Adams, P.E., Project Manager April 27, 2018 Date Brett Kay, Project Engineer April 27, 2018 Date USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan 2.0 2.1 Page 2 INTRODUCTION Introduction and Scope This Construction Quality Control (CQC) Plan has been prepared by Nobis Engineering, Inc. (Nobis) and is submitted to the United States Army Corps of Engineers, New England District (USACE) and United States Environmental Protection Agency (USEPA). Nobis is under contract with the United States Army Corps of Engineers, New England District (USACE) for Remediation Services in the Lord Brook Source Areas (LBSA) at the Elizabeth Mine Superfund Site (the Site) in South Strafford, Vermont as well as additional activities associated with the Phase 2 Remedial Action (RA). The scope of this plan is to outline the Quality Control (QC) and Quality Assurance (QA) procedures to be followed, and implemented, during Remediation Services in the LBSA, specifically closure activities in the South Open Cut (SOC) and South Mine (SM) areas. For a detailed project Scope of Work, refer to the Construction Work Plan (CWP). Additional details for other specific tasks of the RA are provided in the Project Management Plan (PMP), Environmental Protection Plan (EPP) and Erosion and Sediment Control Plan (ESCP). References to the Design Drawings (DD) and Technical Specification (TS) provided herein shall include the Appendix C - Design Drawings (26 pages) and Appendix D – Specifications (223 pages), respectively, prepared by AMEC Environmental & Infrastructure, Inc. (AMEC) for the “Basis of Design Report, Phase 2 Remedial Action: Lord Brook Source Areas, Remedial Design, Final Submittal for Elizabeth Mine Superfund Site, South Strafford, Vermont”, dated September 2014. Refer to the stand-alone Accident Prevention Plan (APP) and Quality Assurance Project Plan (QAPP) / Sampling and Analysis Plan (SAP) documents prepared by Nobis for applicable site health and safety information, and general project quality assurance information, respectively. After acceptance of the CQC Plan, Nobis will notify the Contracting Officer in writing of any proposed changes. Proposed changes are subject to acceptance by the Contracting Officer as per Section 01 45 00.00 10 Part 3.2.3 of the Technical Specifications. 2.2 Purpose This document outlines the QC procedures to be followed by Nobis Engineering to provide the necessary supervision, control and testing of items of work. Items of work include those of the prime, suppliers and subcontractors. The overall purpose of the QC plan is to monitor work progress to assure that it is performed in conformance with the contract documents with respect to the contractor-furnished equipment, materials, workmanship, construction, finished product and functional performance. 2.3 Site Description and History The PMP includes a detailed site description, site history, and presentation of the previous investigations and removal actions. In addition, the PMP includes a discussion on the RA activities. USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan 2.4 Page 3 Project Team The Project Team for this Task Order (TO-1) has been organized to provide the USACE with qualified and efficient technical and management staff with clearly defined lines of authority and responsibilities. Because of their unique knowledge of the Site acquired through site investigations and construction/implementation of past NTCRA activities at the Site, Nobis will utilize project team members, Northwoods Excavation (Northwoods), and SLR Consulting, Inc (SLR), as key subcontractors. Maine Drilling and Blasting, Inc. (MD&B), a specialty blasting subcontractor, and CH2M Hill, Inc. (CH2) will also be utilized as project team members. Key project personnel and responsibilities are listed in Table 2-1. The function and responsibilities of the Nobis Team Key Personnel are described below. A Project Organization Chart with additional engineering, regulatory, safety support personnel and alternates is included as Chart C2-1. Table 2-1 Key Personnel Project Personnel Ed Hathaway John Schmeltzer Steve Dunbar, P.E. Dean Brammer Nick Skianes Randy Lecuyer Pete Delano, P.E. Chris Adams, P.E. Andrew Boeckeler, P.G. Rich Rizza, P.G. Tom Bobowski, P.E., P.G. Ian Hutchison, Ph.D., P.E. Brett Kay Nicholas Zanchi Donald Pipatti 3.0 Responsibility USEPA Project Manager VTANR (VTDEC) Project Manager USACE Project Manager USACE Technical Manager USACE Contracting Officer Representative and Project Engineer USACE Chief Construction Representative Nobis Program Manager Nobis Project Manager Nobis QA/QC Manager, Hydrogeologist Nobis Site QC Supervisor Nobis Corporate Health & Safety Officer SLR Mining Engineer Nobis Project Engineer Nobis Site Safety and Health Officer Nobis/Northwoods Site Superintendent PROJECT QUALITY OBJECTIVES This CQC Plan was developed to provide QC measures applicable to administrative, engineering, and technical activities associated with this work. The requirements of this plan are also applicable to Nobis-affiliated project support groups and subcontractors. 4.0 4.1 AUTHORITY AND RESPONSIBILITIES Program Manager (PO) The PO Manager is Pete Delano of Nobis. The PO Manager is responsible for the overall development, coordination, and contractual compliance of program efforts. Specific USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan Page 4 responsibilities include: Maintaining communication with the Project and Site Managers, as necessary, to ensure proper progress; Ensuring completion of contractual requirements by Nobis and by subcontractors retained by Nobis; and, Regularly monitor the performance and communication of the project management and field personnel regarding their project responsibilities. 4.2 Project Manager (PM) The PM is Chris Adams of Nobis. The PM is responsible for the development, coordination, and technical performance of Project Tasks. Specific responsibilities include: Oversight of, and communication with, the Quality Assurance/Quality Control Manager, Site Quality Control Supervisor, Project Safety Personnel, and Site Superintendent; Monitoring the completion of Tasks required by the Project Contract by Nobis employees and subcontracted personnel; Overall assurance of cost controls, technical accuracy, product quality, regulatory compliance, the health and safety of project personnel, and overall management of employees working on the project; Adhering to the established Project Schedule, Scope of Work, and Budget; and, Providing required submittals to appropriate USACE personnel. 4.3 Corporate Health and Safety Manager (CHSO) The CHSO is Tom Bobowski of Nobis. The CHSO has the overall responsibility for implementing Nobis’ health and safety program, ensuring adequate resources are available to administer the health and safety requirements of this contract and delivery order. Specific responsibilities include: 4.4 Reviewing and approving final APPs; Serving as the primary contact to review safety and health measures that may arise; Approving revised or new safety protocols for field operations; Coordinating revisions to the APP with the Site Safety & Health Officer; Assisting in the investigation of near misses, incidents and major accidents; Selecting proper personal protective equipment (PPE) for planned Site activities; and, Conducting periodic inspections for compliance with the APP. Quality Assurance/Quality Control (QA/QC) Manager The QA/QC Manager is Andrew Boeckeler of Nobis. The QA/QC Manager is responsible for the development, coordination, and performance of the QA/QC program. Specific responsibilities include: USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan Page 5 Reviewing and approving final plans and submittals including, but not limited to, the SAP/QAPP and CQCP; Oversees QA/QC corrective actions; Approving revised QA/QC procedural changes; Coordinating revisions to the QAPP and CQC Plan with the QA/QC Supervisor and QC Supervisor, respectively; Reporting significant QA/QC issues/concerns to the PM; and, Conducting periodic inspections for compliance with the overall QA/QC Program. 4.5 Site Quality Control Supervisor (QCS) The QCS is Adam Morse of Nobis. The (QCS) supervises on-site QC personnel and conducts QC inspections. The QCS is responsible for overall compliance with the established QA/QC measures and protocol established in the QAPP/SAP and the Construction Quality Management (CQM) System established by the USACE. These measures assure adequate quality of workmanship and products for each Phase of the project. The QCS’s responsibilities include, but are not limited to the following: Evaluating the quality of work performed by the Earthwork Contractor (Northwoods) and Subcontractors by assuring surveillances are performed against the requirements specified in this CQCP, project specifications, and procedures developed and implemented for project activities or contractual obligations; Stopping work if deemed appropriate (Nobis will provide a letter to the CQC System Manager signed by an authorized official of Nobis Engineering, Inc. delegating responsibilities and authority to act as the CQS system manager on behalf of Nobis Engineering, a copy of the letter will be furnished to the USACE); Providing clarification and guidance to the Earthwork Contractor and Subcontractors’ personnel concerning Quality matters; Verifying corrective actions to be taken for significant conditions adverse to quality; Maintaining programmatic quality records identified in procedures, work plans, or other documents as applicable; Reviewing procurement documents and changes prior to award for the inclusion of quality requirements; Assuring that the CQC Plan is consistently implemented during construction; Interfacing with the PM on QC issues as necessary; Developing, implementing, reviewing and updating CQC implementation procedures; Reviewing Earthwork Contractor and Subcontractor Submittals; Attending regulatory and CQC-related meetings on-site; Familiarizing CQC staff with the site, project documents, and CQC requirements; Managing daily activities of the Technical Quality Control Assistants; Reviewing daily reports and/or daily field logs from Technical Quality Control Assistants; USACE Contract No. W912WJ18D0001 Document Tracking No.: 94501.CQCP.01 USACE Task Order No. W912WJ18F0025 Elizabeth Mine – Lord Brook Source Areas

Construction Quality Control Plan Page 6 Preparing a Daily CQC Report for work performed on the project documenting reported relevant observations; Addressing nonconforming conditions, issues, or first article inspections (FAIs) as noted by QC personnel; Providing verification that corrective actions have been affected; and, Informing the PM, as necessary, of unresolved deviations from the CQC Plan, Design Drawings, and/or Technical Specifications. The QCS shall have a direct line of communication to project personnel, the USACE project engineer, subcontractors, material suppliers, vendors, services and regulatory agencies for providing quality control directions and status of the program. QC related activities and/or problems shall be directed to the QCS. The QCS shall represent the PM on contacts with outside QA agencies, such as code inspectors, subcontractors, vendors or suppliers. The QCS, or a designated alternate, shall be on-site during the Site operation and activities. 4.6 Technical Quality Control Assistant (QCA) Given the many different technical aspects of the project, Nobis anticipates the need for additional expertise with regard to material submittal review, plan review, and as-built development. Nobis will assign QCAs for various tasks for each Phase of the project, as appropriate. QCAs will review chosen submittals for conformance to plan specifications, assist the QCS with coordination of required tests, and provide technical guidance as-necessary for as-built generation. Specific items anticipated to require assistance include, but are not limited to, dewatering of the pit lakes, blasting activities, and installation of the cover systems in the SOC and SM areas. 4.7 Quality Control Laboratory (QCL) The QCL for this project is Geotesting Express of Acton, Massachusetts or other geotechnical testing laboratories approved by Nobis and USACE. The QCL is responsible for performing required geotechnical testing sent to the laboratory by the QCS or Nobis, in accordance with the Technical Specifications during remedial activities. 4.8 Quality Control Field Testing (QCFT) QCFT for this project will be provided by John Turner Consulting, Inc of White River Junction, Vermont, or another field testing firm approved by Nobis and USACE. The QCFT is responsible for performing required field testing on materials installed at the Site the Northwoods, Nobis, or other team subcontractor, in accordance with the Technical Specifications during remedial activities. 4.9 Site Safety and Health Officer (SSHO) The SSHO is Nicholas Zanchi of Nobis. The

4.1 Program Manager (PO) 3 4.2 Project Manager (PM) 4 4.3 Corporate Health and Safety Manager (CHSO) 4 4.4 Quality Assurance/Quality Control (QA/QC) Manager 4 4.5 Site Quality Control Supervisor (QCS) 5 4.6 Technical Quality Control Assistant (QCA) 6 4.7 Quality Control Laboratory (QCL) 6 4.8 Quality Control Field Testing (QCFT) 6