Crown-Indigenous Relations Relations Couronne-Autochtones l ♦I and Northern Affairs Canada et Affaires du Nord Canada Government of Northwest Territories Gouve<nement do, Territoires du Nord-Ouest GIANT MINE REMEDIATION PROJECT Dust Management and Monitoring Plan Version 1.0 January 2019 Giant Mine Re1nediation Project Dust Management and Monitoring Plan TABLE OF CONTENTS 1 INTRODUCTION .........................................................................................................................1-1 1.1 General Setting ................................................................................................................................. 1-1 1.2 Giant Mine Remediation Project Team Overview ............................................................................. 1-4 1.3 Giant Mine Remediation Project Overview ....................................................................................... 1-4 1.3.1 Dust Management and Monitoring Plan Overview ...................................................................... 1-6 1.3.2 GMRP Environment, Health & Safety, and Community Policy .................................................... 1-8 1.3.3 Regulatory Framework ................................................................................................................ 1-8 1.3.4 Linkages to other Plans ............................................................................................................... 1-9 1.4 Training and Personnel Safety .......................................................................................................... 1-9 2 AIR QUALITY AND DUST AT GIANT MINE ............................................................................... 2-1 2.1 Air Quality Summary ......................................................................................................................... 2-1 2.2 Primary Dust Sources ....................................................................................................................... 2-1 2.2.1 Tailings Containment Areas ......................................................................................................... 2-2 2.2.2 Roads and Roadworks ................................................................................................................ 2-2 2.2.3 Site Activities as Sources of Dust ................................................................................................ 2-3 2.3 Factors Contributing to Dust Generation .......................................................................................... 2-3 2.3.1 Precipitation and Evaporation ...................................................................................................... 2-3 2.3.2 Wind ............................................................................................................................................. 2-4 2.3.3 Soils and Contamination .............................................................................................................. 2-9 2.3.3.1 Soil Chemistry ......................................................................................................................... 2-11 2.3.3.2 Soil Erodibility (Likelihood to Generate Dust) ......................................................................... 2-13 3 BEST MANAGEMENT PRACTICES...........................................................................................3-1 3.1 Scheduling and Staging .................................................................................................................... 3-2 3.2 Short Term Dust Suppressants......................................................................................................... 3-3 3.3 Physical Coverings ........................................................................................................................... 3-4 3.4 Wind Reduction ................................................................................................................................. 3-5 PHASE 1 – EXISTING CONDITION .......................................................................................................3-6 4 DUST MANAGEMENT AND MITIGATION – PHASE 1 .............................................................. 4-1 4.1 Dust Sources ..................................................................................................................................... 4-1 4.2 Dust Management Best Practices – Existing Condition.................................................................... 4-1 4.2.1 Scheduling and Staging ............................................................................................................... 4-1 4.2.2 Short Term Dust Suppressants ................................................................................................... 4-2 4.2.3 Physical Coverings ...................................................................................................................... 4-2 4.3 Activity-Specific Mitigation Measures – Existing Condition............................................................... 4-2 i January 2019 Giant Mine Re1nediation Project Dust Management and Monitoring Plan 4.3.1 Exposed Tailings ......................................................................................................................... 4-2 4.3.2 Roads and Roadworks ................................................................................................................ 4-3 4.3.3 Earthworks ................................................................................................................................... 4-3 4.3.3.1 Excavation of Tailings for Paste and Remediation ................................................................... 4-4 4.3.4 Drilling .......................................................................................................................................... 4-5 5 MONITORING AND RESPONSE FRAMEWORK ...................................................................... 5-1 5.1 Wind Monitoring ................................................................................................................................ 5-1 5.2 Visual Dust Monitoring ...................................................................................................................... 5-3 5.3 Air Quality Monitoring ........................................................................................................................ 5-4 5.3.1 Activity-specific monitoring .......................................................................................................... 5-6 5.3.1.1 Response to Activity-Specific OEL Exceedance ...................................................................... 5-6 5.3.2 Perimeter Monitoring ................................................................................................................... 5-6 5.3.2.1 Response to Perimeter RBAL Exceedance ............................................................................. 5-7 5.3.3 Community Monitoring ................................................................................................................. 5-7 5.3.3.1 Response to Community RBAL Exceedance ........................................................................... 5-8 5.4 Contingencies ................................................................................................................................... 5-8 PHASE 2 – ACTIVE REMEDIATION AND ADAPTIVE MANAGEMENT .............................................. 5-10 6 DUST MANAGEMENT AND MITIGATION – PHASE 2 .............................................................. 6-1 6.1 Anticipated Dust Sources .................................................................................................................. 6-1 6.2 Dust Risk Assessment Methodology ................................................................................................ 6-1 6.2.1 Dust Generating Activities ........................................................................................................... 6-2 6.2.2 Soil Characteristics and Contamination ....................................................................................... 6-2 6.2.3 Selection of Mitigation Measures ................................................................................................. 6-3 6.3 Dust Management Best Practices – Phase 2 ................................................................................... 6-4 6.3.1 Exposed Tailings ......................................................................................................................... 6-4 6.3.2 Roads and Roadworks ................................................................................................................ 6-4 6.3.3 Earthworks ................................................................................................................................... 6-5 6.3.3.1 Excavation of Tailings for Paste and Remediation ................................................................... 6-5 6.3.3.2 Quarrying/Borrow ...................................................................................................................... 6-6 6.3.4 Infrastructure Demolition and Consolidation ................................................................................ 6-6 6.3.5 Drilling .......................................................................................................................................... 6-7 6.3.6 Blasting .......................................................................................................................................