Document:

Exhibit 4.10

 

 

Form 51-102F3

Material Change Report

 

	
Item 1
    	
 
    	
Name and Address of Company
    
    Pretium Resources Inc. (“Pretivm” or the “Company”)
   Suite 2300, Four Bentall Centre
   1055 Dunsmuir Street
   PO Box 49334
   Vancouver, BC V7X 1L4
    
	
 
    	
 
    	
 
    
	
Item 2
    	
 
    	
Date of Material Change
    
   April 27, 2020
    
	
 
    	
 
    	
 
    
	
Item 3
    	
 
    	
News Release
    
   The news release dated April 27, 2020 was disseminated through Nasdaq   GlobeNewswire and filed on SEDAR.
    
	
 
    	
 
    	
 
    
	
Item 4
    	
 
    	
Summary of Material Change
    
    On April 27, 2020, Pretivm announced that its Board of   Directors (the “Board”) has appointed Jacques Perron as President and Chief   Executive Officer, effective April 27, 2020.
    
	
 
    	
 
    	
 
    
	
Item 5
    	
 
    	
 
    
	
 
    	
 
    	
 
    
	
Item 5.1
    	
 
    	
Full Description of Material Change
    
	
 
    	
 
    	
 
    
	
 
    	
 
    	
On April 27, 2020, Pretivm announced that its   Board of Directors has appointed Jacques Perron as President and Chief   Executive Officer, effective April 27, 2020.
    
   Mr. Perron’s career of more than 35 years in the global mining industry   has included extensive technical and operational experience. Most recently   Mr. Perron was President, Chief Executive Officer and Director of   Thompson Creek Metals Company Inc. until it was acquired by Centerra Gold Inc   in 2016. He joined Thompson Creek as Chief Executive Officer in 2013 and took   on the additional role of President in 2014.
    
   Among his previous senior executive positions in mining, he was President and   CEO of St. Andrew Goldfields (2007-2013), Senior Vice President of Iamgold   (2006-2007) and Senior Vice President Canada of Cambior Inc. (2004-2006).
    
   Mr. Perron has been a director of the Canadian Mineral Industry   Education Foundation since 2007. He earned a Bachelor of Science degree in   Mining Engineering from l’École Polytechnique de Montréal.
    
   Mr. Perron succeeds Joseph Ovsenek, who was Pretivm’s President and CEO   since 2017, President since 2015 and Executive Vice-President and Chief   Development Officer from 2011 to 2015.
    

 

 

	
 
    	
 
    	
Pretivm’s Board of Directors intends to appoint Mr. Perron   as a director following the Company’s annual general meeting of shareholders,   effective May 1, 2020.
    
	
 
    	
 
    	
 
    
	
Item 5.2
    	
 
    	
Disclosure for Restructuring Transactions
    
    Not applicable.
    
	
 
    	
 
    	
 
    
	
Item 6
    	
 
    	
Reliance on subsection 7.1(2) or   (3) of National Instrument 51-102
    
   Not applicable.
    
	
 
    	
 
    	
 
    
	
Item 7
    	
 
    	
Omitted Information
    
    Not applicable.
    
	
 
    	
 
    	
 
    
	
Item 8
    	
 
    	
Executive Officer
    
   Vladimir Cvijetinovic
   Vice President, Legal and Corporate Secretary
   Phone: 604-566-8781
    
	
 
    	
 
    	
 
    
	
Item 9
    	
 
    	
Date of Report
    
   April 27, 2020
    

 

Forward-Looking Information

 

This material change report contains “forward-looking information” and “forward looking statements” within the meaning of applicable Canadian and United States securities legislation (collectively herein referred to as “forward-looking information”), including the “safe harbour” provisions of Canadian provincial securities legislation and the U.S. Private Securities Litigation Reform Act of 1995, Section 21E of the U.S. Securities Exchange Act of 1934, as amended, and Section 27A of the U.S. Securities Act of 1933, as amended.  Wherever possible, words such as “plans”, “expects”, “guidance”, “projects”, “assumes”, “budget”, “strategy”, “scheduled”, “estimates”, “forecasts”, “anticipates”, “believes”, “intends”, “modeled’, “targets” and similar expressions or statements that certain actions, events or results “may”, “could”, “would”, “might” or “will” be taken, occur or be achieved, or the negative forms of any of these terms and similar expressions, have been used to identify forward-looking information.  Forward-looking information may include, but is not limited to, information with respect to Board of Directors composition and membership. Forward-looking information is subject to a variety of known and unknown risks, uncertainties and other factors that could cause actual results, actions, events, conditions, performance or achievements to materially differ from those expressed or implied by the forward-looking information including, without limitation, those set out in our Annual Information Form and From 40-F, each dated February 21, 2020, for the year ended December 31, 2019, our MD&A for the years ended December 31, 2019 and 2018, and our other disclosure documents as filed in Canada on SEDAR at www.sedar.com and in the United States through EDGAR at the Security and Exchange Commission’s website at www.sec.gov (collectively, “the Pretivm Disclosure Documents”). Our forward-looking information is based on the assumptions, beliefs, expectations and opinions of management on the date the statements are made, including, without limitation, those set out in the Pretivm Disclosure Documents, many of which may be difficult to predict and beyond our control. Forward-looking information is not a guarantee of future performance. There can be no assurance that forward-looking information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such information. Forward-

 

2

 

looking information involves statements about the future and is inherently uncertain, and our actual achievements or other future events or conditions may differ materially from those reflected in the forward-looking information due to a variety of risks, uncertainties and other factors. For the reasons set forth above, readers should not place undue reliance on forward-looking information. We do not assume any obligation to update forward-looking information, whether as a result of new information, future events or otherwise, other than as required by applicable law. For the reasons set forth above, readers should not place undue reliance on forward-looking information. Neither the TSX nor the NYSE has approved or disapproved of the information contained herein.

 

3Exhibit 4.11

Technical   Report on the Brucejack Gold Mine, Northwest British Columbia PRESENTED TO   Pretium Resources Inc. EFFECTIVE DATE: MARCH 9, 2020 220008-00-RPT-001   QUALIFIED PERSONS: ALISON SHAW, PH.D., P.GEO. CALVIN BOESE, P.ENG., M.SC.   COLIN FRASER, P.GEO. M.SC. HASSAN GHAFFARI, P.ENG., M.A.SC. IVOR W.O. JONES,   M.SC., P.GEO., FAUSIMM JIANHUI (JOHN) HUANG, PH.D., P.ENG. LAURA-LEE   FINDLATER, B.SC., P.GEO. MAUREEN PHIFER, P.ENG., B.SC. MAURICIO HERRERA,   PH.D., P.ENG. ROLF SCHMITT, M.SC., P.GEO. TIMOTHY COLEMAN, P.ENG.,   BENG(HONS), ACSM, M.SC. Tetra Tech Canada Inc. Suite 1000 – 10th Floor, 885   Dunsmuir Street Vancouver, BC V6C 1N5 CANADA Tel 604.685.0275 Fax   604.684.6241 Exhibit 4.11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE This page left intentionally   blank. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE TABLE OF CONTENTS 1.0 SUMMARY   ...................................................................................................................................1-1   1.1 1.2 1.3 1.4 Introduction   ........................................................................................................................................   1-1 Property Description and Location   ....................................................................................................   1-2 Geology and Mineralization ...............................................................................................................   1-2 Mineral Resource Estimates   ..............................................................................................................   1-3 1.4.1 1.4.2 Drilling, Sampling, Assaying, and Data Verification   ............................................................. 1-3 Mineral   Resource   Estimation................................................................................................   1-4 1.5 Mineral Reserve Estimates   ................................................................................................................   1-6 1.5.1 Mineral Reserve Comparison   ...............................................................................................   1-7 1.6 1.7 Mining   Methods..................................................................................................................................   1-7 Mineral Processing and Metallurgical Testing   ...................................................................................   1-8 1.7.1 1.7.2 1.7.3 Early Metallurgical Test Work and Pilot Plant   Operation...................................................... 1-9 Recent   Metallurgical Test   Work............................................................................................   1-9 Current Operation   ...............................................................................................................   1-10 1.8 1.9 1.10 1.11 Recovery Methods   ...........................................................................................................................   1-10 Project Infrastructure   .......................................................................................................................   1-13 Environmental Studies, Permitting and Social and Community Impact   .......................................... 1-18 Capital and Operating Cost   Estimates   ............................................................................................   1-18 1.11.1 Capital Cost Estimate .........................................................................................................   1-18 1.11.2 Operating Cost   Estimate.....................................................................................................   1-19 Economic Analysis...........................................................................................................................   1-20 Project and Operation Risks   ............................................................................................................   1-21 Conclusions and Recommendations   ...............................................................................................   1-21 1.12 1.13 1.14 2.0 INTRODUCTION   ..........................................................................................................................2-1   2.1 2.2 2.3 2.4 Terms of Reference   ...........................................................................................................................   2-1 Site Visits ...........................................................................................................................................   2-2 Qualified Persons   ..............................................................................................................................   2-2 Information and Data Sources   ...........................................................................................................   2-4 3.0 RELIANCE ON OTHER EXPERTS   .............................................................................................3-1   3.1 3.2 3.3 3.4 3.5 Introduction   ........................................................................................................................................   3-1 Status of Mining Leases and Mineral Claims ....................................................................................   3-1 Environment, Social and Sustainability   .............................................................................................   3-1 Marketing Studies ..............................................................................................................................   3-1 Economic   Analysis.............................................................................................................................   3-1 4.0 PROPERTY DESCRIPTION AND   LOCATION............................................................................4-1   4.1 4.2 4.3 4.4 4.5 Location   .............................................................................................................................................   4-1   Tenure................................................................................................................................................   4-2 Status of Mining Titles .......................................................................................................................   4-2 Confirmation of Tenure   ......................................................................................................................   4-5 Royalties, Fees, and Taxes ...............................................................................................................   4-5 i 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 5.0 ACCESSIBILITY, CLIMATE,   LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY   ........................................................................................................................5-1   5.1 5.2 5.3 5.4 Climate and Physiography   .................................................................................................................   5-1 Vegetation..........................................................................................................................................   5-1 Accessibility   .......................................................................................................................................   5-1   Infrastructure......................................................................................................................................   5-4 6.0 HISTORY   .....................................................................................................................................6-1   6.1 6.2 6.3 6.4 6.5 Early   Exploration................................................................................................................................   6-1 Exploration by Silver Standard Resources Inc. (2001 to   2010)......................................................... 6-2 Previous   Feasibility Studies on the Property   (1990)..........................................................................   6-4 Prior Mineral Production ....................................................................................................................   6-4 Preliminary Economic Assessment (2010)   ........................................................................................   6-4 7.0 GEOLOGICAL SETTING AND MINERALIZATION   ....................................................................7-1 7.1   7.2 7.3 Regional Geological Setting   ..............................................................................................................   7-1 Local Geology   ....................................................................................................................................   7-3 Brucejack Project Area   Geology........................................................................................................   7-6 7.3.1 7.3.2 7.3.3 7.3.4 7.3.5   Lithology..............................................................................................................................   7-10 Geochronology ...................................................................................................................   7-12 Structure   .............................................................................................................................   7-12 Alteration.............................................................................................................................   7-14   Mineralization......................................................................................................................   7-14 8.0 DEPOSIT TYPES   .........................................................................................................................8-1   9.0 EXPLORATION   ...........................................................................................................................9-1   9.1 9.2 9.3 Exploration – 2011 to   2014................................................................................................................   9-1 Exploration – 2015 to 2018................................................................................................................   9-3 Exploration – 2019   .............................................................................................................................   9-8 10.0 DRILLING ..................................................................................................................................10-1   10.1 Pretivm Drilling (2019)   .....................................................................................................................   10-4 Drilling   Activities..................................................................................................................   10-4 Drilling Contractors and Equipment   ....................................................................................   10-4 Drill Coordinates and Downhole Surveys   ...........................................................................   10-4 Diamond Drill Core Logging Procedures   ............................................................................   10-5 Summary of Results   ...........................................................................................................   10-5 10.2 Opinion of Qualified   Person.............................................................................................................   10-7 11.0 SAMPLE PREPARATION, ANALYSES, AND SECURITY   .......................................................11-1 11.1 Sample   Preparation, Analysis, and Security   ...................................................................................   11-1 11.1.1 11.1.2 11.1.3 Drillhole Sampling   ...............................................................................................................   11-1 Sample Preparation and Analysis by Analytical Laboratory   ............................................... 11-2 Specific Gravity and   Bulk   Density.......................................................................................   11-2 11.2 11.3 Quality Assurance and Quality   Control............................................................................................   11-4 Qualified Person’s Opinion on Sample Preparation, Security, and   Analytical Procedures ............ 11-5 ii 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE 12.0 DATA VERIFICATION   ...............................................................................................................12-1   12.1 Data Verification by Qualified Person   ..............................................................................................   12-1 12.2 Qualified Person’s Opinion of the Verification   .................................................................................   12-1 13.0 MINERAL PROCESSING AND METALLURGICAL TESTING .................................................13-1   13.1 Previous Bench-Scale Test Work   ....................................................................................................   13-1 13.1.1 13.1.2 13.1.3 13.1.4 13.1.5 13.1.6 13.1.7 Sample Description and   Characteristics.............................................................................   13-1 Gold and Silver Recovery Tests – Gravity Concentration   .................................................. 13-3 Gold and Silver   Recovery Tests – Flotation   Concentration................................................ 13-5 Gold and   Silver Recovery Tests – Cyanidation   .................................................................. 13-5   Variability Tests ..................................................................................................................   13-6 Locked Cycle Tests _ Gravity Separation + Flotation Concentration   ................................. 13-7 Other Processing Related   Tests.........................................................................................   13-9 13.2 13.3 2013 Pilot Plant Testing   ...................................................................................................................   13-9 Mill Operation Optimization/Expansion Test Work ........................................................................   13-11 13.3.1 13.3.2 13.3.3 13.3.4 13.3.5 13.3.6 Sample   Description...........................................................................................................   13-11 Mineralogical Analysis on Flotation Tailings and Tailings Thickener   Underflow .............. 13-13 Mineralogical Analysis on Flotation   Concentrates............................................................   13-13 Comminution Test Work ...................................................................................................   13-15 Gold and Silver Recovery Test Work   ...............................................................................   13-16 Solid and Liquid Separation Test Work ............................................................................   13-26 13.4 Mill Operations Optimization / Expansion Process Simulations   .................................................... 13-28 13.4.1 13.4.2   13.4.3 Grinding Circuit .................................................................................................................   13-28 Gravity Simulations   ...........................................................................................................   13-32 Flotation Simulations ........................................................................................................   13-32 13.5 13.6 Production Data 2017 to 2019   .......................................................................................................   13-32 Metallurgical Performance Projection   ............................................................................................   13-33 14.0 MINERAL RESOURCE ESTIMATES   ........................................................................................14-1   14.1 14.2 14.3 14.4 Disclosure   ........................................................................................................................................   14-1 Known Issues that Materially Affect Mineral Resources   ................................................................. 14-1   Modelling Approach   .........................................................................................................................   14-3 Data Provided for Estimation ...........................................................................................................   14-4 14.4.1 14.4.2 14.4.3 Assay Dataset for Grade Estimation   ..................................................................................   14-4 Assay Data Import Procedure.............................................................................................   14-5 Triangulations   .....................................................................................................................   14-5 14.5 14.6 Geological Interpretation and Modelling   ..........................................................................................   14-7 Data Selection and   Preparation.......................................................................................................   14-9 14.6.1 14.6.2 14.6.3 14.6.4 Update   Area........................................................................................................................   14-9 Compositing   ......................................................................................................................   14-10 Grade Populations   ............................................................................................................   14-11 Summary Statistics   ...........................................................................................................   14-13 14.7 Estimation   ......................................................................................................................................   14-14 14.7.1 14.7.2 14.7.3 Methodology .....................................................................................................................   14-14 Parameter Optimization   ....................................................................................................   14-16 Variography ......................................................................................................................   14-16 iii 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.7.4 14.7.5 14.7.6 14.7.7   Search Parameters   ...........................................................................................................   14-21 Upper Tail Modelling of High Grade Population in MIK Estimation   .................................. 14-22 Specific Gravity and Bulk   Density.....................................................................................   14-23 Other Variables   .................................................................................................................   14-24 14.8 Model Validation   ............................................................................................................................   14-24 14.8.1 14.8.2 14.8.3 14.8.4 14.8.5 Statistical Checks – Final Gold and   Silver Grade Estimates ............................................ 14-25   Grade Trend Plots   ............................................................................................................   14-26 Visual Validation ...............................................................................................................   14-29 Reconciliation of the Resource Model with 2019 Production   ........................................... 14-31 Concluding Remarks: Model   Validation............................................................................   14-33 14.9 Mineral Resource Classification   ....................................................................................................   14-34 14.10 Mineral Resource Reporting ..........................................................................................................   14-35 14.10.1   Depletion...........................................................................................................................   14-35 14.10.2 January 2020 Mineral Resource for the Brucejack Deposit   ............................................. 14-35 14.10.3 Resource   Sensitivity   .........................................................................................................   14-36 14.11 Comparison with the January 2019 Resource Estimate   ............................................................... 14-37 15.0   MINERAL RESERVE ESTIMATES   ...........................................................................................15-1   15.1 15.2 15.3 15.4 15.5 General   ............................................................................................................................................   15-1 Cut-off Grade   ...................................................................................................................................   15-1 NSR   Model.......................................................................................................................................   15-1 Mining Shapes .................................................................................................................................   15-3 Orebody Description   ........................................................................................................................   15-3 15.5.1 Valley of the Kings   Zone.....................................................................................................   15-3 15.5.2 West   Zone...........................................................................................................................   15-4 Mine Call   Factor...............................................................................................................................   15-4 Mineral Reserve Depletion Due to Grade Control Program   ............................................................ 15-7 Dilution   and Recovery   Estimates.....................................................................................................   15-7 2019 Mineral Reserve Reconciliation   ............................................................................................   15-10 15.6 15.7 15.8 15.9 15.10 2020 Mineral Reserves   ..................................................................................................................   15-11 15.11 Mineral Reserve Comparison ........................................................................................................   15-15 16.0 MINING METHODS   ...................................................................................................................16-1   16.1 16.2 General ............................................................................................................................................   16-1 Mine Design   .....................................................................................................................................   16-1 16.2.1 16.2.2 16.2.3 Access and Ramp Infrastructure   ........................................................................................   16-1 Level Development .............................................................................................................   16-3 Stope Design   ......................................................................................................................   16-7 16.3 Mining Method and Sequence .........................................................................................................   16-9 16.3.1 16.3.2 16.3.3 16.3.4 16.3.5 Block Definition   ...................................................................................................................   16-9 Stope Cycle   ......................................................................................................................   16-10 Stope Sequence   ...............................................................................................................   16-11   Backfilling..........................................................................................................................   16-13 Paste Backfill Test   Work...................................................................................................   16-13 iv 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.4 Development and   Production Schedule ........................................................................................   16-15 16.4.1 16.4.2 16.4.3 Production Rate   ................................................................................................................   16-15 Sustaining Development...................................................................................................   16-16 LOM Production   Schedule................................................................................................   16-17 16.5 Geotechnical ..................................................................................................................................   16-18 16.5.1 16.5.2 16.5.3 Rock Mass   Properties.......................................................................................................   16-19 Mine-scale Fault Zones   ....................................................................................................   16-20 Underground Rock Mechanics   .........................................................................................   16-21 16.6 Mobile Equipment   Requirements...................................................................................................   16-26 16.6.1 Production Phase   .............................................................................................................   16-26 16.6.2 Support Equipment   ...........................................................................................................   16-28 Ventilation   ......................................................................................................................................   16-30 16.7 16.7.1 16.7.2 16.7.3 16.7.4 16.7.5 16.7.6 16.7.7 Design Criteria   ..................................................................................................................   16-31 Total Airflow   Requirements...............................................................................................   16-31 Auxiliary Ventilation   ..........................................................................................................   16-31 Permanent Primary   Fans..................................................................................................   16-32 Mine Air Heating   ...............................................................................................................   16-33 Conveyor Decline   .............................................................................................................   16-33 Emergency Preparedness   ................................................................................................   16-34 16.8 Underground   Infrastructure............................................................................................................   16-36 16.8.1 16.8.2 16.8.3 16.8.4 16.8.5 16.8.6 16.8.7 16.8.8 16.8.9 Mine   Dewatering ...............................................................................................................   16-36 Solids and Slimes Handling   ..............................................................................................   16-38 Materials Handling ............................................................................................................   16-38 Power Requirements and Electrical Distribution   .............................................................. 16-40   Compressed Air ................................................................................................................   16-45 Service Water Supply   .......................................................................................................   16-45 Fueling and Lubrication ....................................................................................................   16-46 Workshop and Stores   .......................................................................................................   16-46 Explosives Magazine   ........................................................................................................   16-46 16.8.10 Refuge Stations   ................................................................................................................   16-48 16.8.11 Communications   ...............................................................................................................   16-48 16.8.12 Portal Structure   .................................................................................................................   16-49 16.8.13 Heating System and Propane Storage   .............................................................................   16-49 16.8.14 Propane Supply   ................................................................................................................   16-50 Paste Fill Distribution   .....................................................................................................................   16-51 16.9 16.9.1 16.9.2 16.9.3 16.9.4 Distribution System Design...............................................................................................   16-51 Distribution Approach   .......................................................................................................   16-52 Distribution System Layout ...............................................................................................   16-53 Manpower   Requirements..................................................................................................   16-53 17.0 RECOVERY METHODS ............................................................................................................17-1   17.1 Mineral Processing   ..........................................................................................................................   17-1 17.1.1 17.1.2 17.1.3 Introduction   .........................................................................................................................   17-1 Mill Operation Data   .............................................................................................................   17-1 Flowsheet Development   .....................................................................................................   17-2 v 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.1.4 Plant Design   .......................................................................................................................   17-4 17.1.5 Process Plant   Description...................................................................................................   17-5 17.2 Annual Production Estimate   ..........................................................................................................   17-13 18.0 PROJECT INFRASTRUCTURE   ................................................................................................18-1   18.1 18.2 Overview   ..........................................................................................................................................   18-1 Mine Site Surface Infrastructure   ......................................................................................................   18-5 18.2.1 18.2.2 18.2.3 18.2.4 Mill Facility Description   .......................................................................................................   18-5 Mine Waste   Management...................................................................................................   18-8 Mine Site Ancillary Facilities   .............................................................................................   18-10 Km 72 NPAG Quarry   ........................................................................................................   18-13 18.3 Off-site Infrastructure   .....................................................................................................................   18-13 18.3.1 18.3.2 18.3.3 18.3.4 18.3.5 Transmission   Line.............................................................................................................   18-14 Access   Road.....................................................................................................................   18-14 Knipple Transfer Station Facilities ....................................................................................   18-15 Bowser Aerodrome   ...........................................................................................................   18-16 Wildfire Security and Camp ..............................................................................................   18-17 18.4 18.5 Site Geotechnical Assessment   ......................................................................................................   18-18 Avalanche Hazard Assessment.....................................................................................................   18-19 19.0 MARKET STUDIES AND CONTRACTS   ...................................................................................19-1   19.1 19.2 19.3 19.4 Markets ............................................................................................................................................   19-1 Smelter Terms   .................................................................................................................................   19-1 Concentrate Transportation   .............................................................................................................   19-1 Mining Development   Contracts........................................................................................................   19-2 20.0 ENVIRONMENTAL STUDIES, PERMITTING AND SOCIAL OR COMMUNITY   IMPACT........20-1 20.1 Environment, Social and Sustainability   ...........................................................................................   20-1 20.1.1 20.1.2 20.1.3 Corporate Policies, Guiding Principles and Criteria   ........................................................... 20-1 Social   Setting   ......................................................................................................................   20-4 Consultation   ........................................................................................................................   20-7 20.2 Environmental Assessment Certifications and Permitting   ............................................................... 20-8 20.2.1   20.2.2 20.2.3 Environmental Assessment Certifications   ..........................................................................   20-8 Permits and Other Authorizations.......................................................................................   20-9 Financial Assurance   .........................................................................................................   20-13 20.3 Environment...................................................................................................................................   20-13 20.3.1 20.3.2 20.3.3 20.3.4 20.3.5 20.3.6 20.3.7 20.3.8 20.3.9   Environmental   Setting.......................................................................................................   20-13   Geochemistry....................................................................................................................   20-16   Hydrogeology....................................................................................................................   20-20 Water Management   ..........................................................................................................   20-23 Water Balance   ..................................................................................................................   20-25 Water Quality   ....................................................................................................................   20-29 Waste Management..........................................................................................................   20-30 Air Emission Control   .........................................................................................................   20-31 Closure Plan and Costs ....................................................................................................   20-31 vi 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 21.0 CAPITAL AND OPERATING   COSTS .......................................................................................21-1   21.1 Capital Cost Estimate   ......................................................................................................................   21-1 21.1.1 Summary.............................................................................................................................   21-1 21.1.2 LOM Sustaining Capital Cost Estimate   ..............................................................................   21-1 21.2 Operating Cost   Estimate..................................................................................................................   21-5 21.2.1 21.2.2 21.2.3 21.2.4   Summary.............................................................................................................................   21-5 Mining Operating Cost Estimate   .........................................................................................   21-6 Process Operating Cost Estimate   ......................................................................................   21-7 Mine Site G&A and Site Services Operating Cost   Estimate............................................... 21-8 22.0 ECONOMIC   ANALYSIS.............................................................................................................22-1   22.1 22.2 Introduction   ......................................................................................................................................   22-1 Pre-tax Model...................................................................................................................................   22-2 22.2.1 Metal Price Scenarios   .........................................................................................................   22-5 Smelter Terms .................................................................................................................................   22-5 Markets and   Contracts.....................................................................................................................   22-5 Taxation and Royalty Considerations   ..............................................................................................   22-5 22.5.1 Canadian Income Tax System   ...........................................................................................   22-6 22.5.2 Provincial (BC) Mining Tax System   ....................................................................................   22-7 Royalties   ..........................................................................................................................................   22-7 Sensitivity Analysis   ..........................................................................................................................   22-7 22.3 22.4 22.5 22.6 22.7 23.0 ADJACENT PROPERTIES........................................................................................................23-1   23.1 23.2 23.3 23.4 23.5 Snowfield   Property...........................................................................................................................   23-1 Bowser Property   ..............................................................................................................................   23-1 Kerr-Sulphurets-Mitchell   Property....................................................................................................   23-5 Treaty Creek Property   .....................................................................................................................   23-6 Catear ..............................................................................................................................................   23-6 24.0 OTHER RELEVANT DATA AND INFORMATION   ....................................................................24-1 24.1   Health, Safety, Environmental and Security   ....................................................................................   24-1 25.0 INTERPRETATION AND   CONCLUSIONS................................................................................25-1   25.1 25.2 25.3 25.4 Geology............................................................................................................................................   25-1 Mineral   Resource.............................................................................................................................   25-1 Mineral Reserves   .............................................................................................................................   25-3 Mining   ..............................................................................................................................................   25-3 25.4.1 25.4.2 25.4.3 Underground Mine Geotechnical   ........................................................................................   25-3 Mining Methods ..................................................................................................................   25-3 Waste   Rock.........................................................................................................................   25-4 25.5 Mineral Processing and Metallurgical Testing   .................................................................................   25-4 25.5.1 Metallurgical Testing   ...........................................................................................................   25-4 25.5.2 Mineral Processing   .............................................................................................................   25-4 Environmental   ..................................................................................................................................   25-5 25.6.1   Geochemistry......................................................................................................................   25-5 25.6.2   Hydrogeology......................................................................................................................   25-6 25.6 vii 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 25.6.3 25.6.4 25.6.5 Water   Management ............................................................................................................   25-7 Water Balance   ....................................................................................................................   25-8 Water Quality   ......................................................................................................................   25-8 25.7 25.8 25.9 Capital Cost and Operating Cost Estimates   ....................................................................................   25-9 Economic   Analysis...........................................................................................................................   25-9 Project and Operation Risks   ..........................................................................................................   25-10 26.0 RECOMMENDATIONS   ..............................................................................................................26-1   26.1 26.2 26.3 26.4 Introduction ......................................................................................................................................   26-1   Geology............................................................................................................................................   26-1 Mineral   Resource.............................................................................................................................   26-2 Mining   ..............................................................................................................................................   26-3 26.4.1 26.4.2 26.4.3 Underground Mine Geotechnical   ........................................................................................   26-3 Mining Methods ..................................................................................................................   26-4 Waste   Rock.........................................................................................................................   26-4 26.5 26.6 Mineral Processing and Metallurgical Testing   .................................................................................   26-5 Environmental   ..................................................................................................................................   26-5 26.6.1 26.6.2 26.6.3 26.6.4 26.6.5   Geochemistry......................................................................................................................   26-5   Hydrogeology......................................................................................................................   26-6 Water Management   ............................................................................................................   26-6 Water Balance   ....................................................................................................................   26-6 Water Quality   ......................................................................................................................   26-7 27.0 REFERENCES ...........................................................................................................................27-1   27.1 27.2 27.3 27.4 27.5 27.6 27.7 27.8 27.9 General   ............................................................................................................................................   27-1   Geology............................................................................................................................................   27-1 Metallurgy and Recovery Methods   ..................................................................................................   27-6 Mining   ..............................................................................................................................................   27-7 Mining Geotechnical ........................................................................................................................   27-8 Waste Rock   Disposal.......................................................................................................................   27-9 Avalanche Hazard Assessment.......................................................................................................   27-9 Environmental   ..................................................................................................................................   27-9 Water Management   .......................................................................................................................   27-10 27.10 Water Balance   ...............................................................................................................................   27-10 27.11 Water Quality   .................................................................................................................................   27-10 27.12 Geochemistry.................................................................................................................................   27-11 27.13   Hydrogeology.................................................................................................................................   27-11 27.14 Adjacent Properties   .......................................................................................................................   27-12 viii 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE LIST OF TABLES January 2020   Valley of the Kings Zone and West Zone Mineral Resource(1,2,3,4,5,6)   .................... 1-5 January 2020 Valley of the Kings Zone Mineral   Resource(1) ....................................................... 1-5 West   Zone Mineral Resource, April 2012(1,2)   ................................................................................   1-5 Brucejack Gold Mine Mineral Reserves(1,2) by Mining Zone and Reserve   Category, Effective January 1, 2020   .............................................................................................................   1-6 Comparison of 2020 Mineral Reserves with Mined Actuals to 2019 Reserves   ........................... 1-7 Brucejack Mill 2019 Production Data   .........................................................................................   1-10 LOM Sustaining Capital Cost Estimates   ...................................................................................   1-18 LOM Average Operating Cost   Summary....................................................................................   1-19 Brucejack Gold Mine Economic Performance   Forecast............................................................. 1-20   Summary of QPs ..........................................................................................................................   2-3 Mineral Claims for the Brucejack Property   ...................................................................................   4-2 Exploration History of the Sulphurets Property between 1960 and 2008   .................................... 6-1 Vein Generations in the Valley of   the Kings   Zone......................................................................   7-16 Principal Field-oriented Characteristics of Intermediate-and   Low-sulphidation Epithermal   Systems......................................................................................................................   8-1 Exploration of the Brucejack Property Between 2011 and 2014   .................................................. 9-1 Drilling Summary for   the Brucejack Property   .............................................................................   10-1 Sample Preparation and Analytical Methods Conducted on Pretivm Drill   Samples Between 2014 and 2018.............................................................................................................   11-3 Conventional Grindability and Crushability Test Results   ........................................................... 13-2 SMC Test   Results (2012)   ...........................................................................................................   13-3 Gravity Recoverable Gold Test Results (2012)   ..........................................................................   13-4 Precious Metal Material Balance (2014)   ....................................................................................   13-4 Cyanidation Flowsheet Development Test   Results....................................................................   13-6 Locked Cycle Tests Results   .......................................................................................................   13-8 Bulk Sample Processing Metallurgical   Performances..............................................................   13-11 Major Metallurgical Testing and Simulations Programs 2017–2019   ........................................ 13-11 Head Assay Results (Gekko   2017)   ..........................................................................................   13-12 Head Assay Results (ALS 2018) ..............................................................................................   13-12 Head Assays of Processing Samples   ......................................................................................   13-13 Gold Deportment and Associations of Two Flotation Con – BV   2017...................................... 13-14 Bond Test Results (ALS 2018)   .................................................................................................   13-15 JK Drop Weight Test Results (ALS 2018) ................................................................................   13-16 SMC Test Results and Parameters Derived from SMC Tests (ALS 2018)   .............................. 13-16 Diagnostic Leach Test Results – Gravity   Concentration Tailings (2019) ................................. 13-19 Locked   Cycle Testing Conditions   .............................................................................................   13-23 Locked Cycle Test Results   .......................................................................................................   13-24 Third Cleaner Flotation Results on the Second Locked Cycle   Test......................................... 13-24 Head Assays of Processing   Samples ......................................................................................   13-25 Conventional and Column Flotation Results   ............................................................................   13-26 JKSimMet 3,800 t/d Results at 92%   Availability.......................................................................   13-30 Bruckejack Mill Production Data 2017–2019(1)   .........................................................................   13-33 Table 1-1: Table 1-2: Table 1-3: Table 1-4: Table 1-5: Table 1-6: Table   1-7: Table 1-8: Table 1-9: Table 2-1: Table 4-1: Table 6-1: Table 7-1: Table   8-1: Table 9-1: Table 10-1: Table 11-1: Table 13-1: Table 13-2: Table 13-3:   Table 13-4: Table 13-5: Table 13-6: Table 13-7: Table 13-8: Table 13-9: Table   13-10: Table 13-11: Table 13-12: Table 13-13: Table 13-14: Table 13-15: Table   13-16: Table 13-17: Table 13-18: Table 13-19: Table 13-20: Table 13-21: Table   13-22: Table 13-23: ix 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 14-1: Table 14-2:   Valley of the Kings Zone Mineralized   Domains..........................................................................   14-7 Summary Statistics of Gold and Silver Composited Data by Grouped Domain   in January 2020 Model Updated   Area..........................................................................................   14-14 Thresholds Discretizing High-grade Distribution by Bigdom   .................................................... 14-17 Indicator   Variogram Parameters for High-grade Gold in Bigdom   600...................................... 14-17 Variogram Model for the   Probability of High-grade Gold Indicator Variable at 3.5 g/t Au........ 14-19   Variogram Model for the Probability of High-grade Silver Indicator Variable   at 20 g/t Ag ....... 14-20 Variogram Model for Low-grade Gold Mineralization   ............................................................... 14-21 Variogram   Model for Low-grade Silver Mineralization   ............................................................. 14-21 Search   Parameters for High-grade and Probability of High-grade Variables for Gold   and Silver by Bigdom Inside the Update Area.................................................................................   14-21 Search Parameters for Low grade Gold and Silver Inside the Update   Area............................ 14-22 Mathematical Model Parameters for the   Top MIK Threshold for Each Bigdom ....................... 14-23 Specific   Gravity Values and Bulk Density Conversion Factors for Resource Modelling in   the Update   Area....................................................................................................................   14-24 Global Comparison of Mean Estimated and Input Composite Grade Data for   Gold and Silver by BIGDOM   ....................................................................................................................   14-25 January 2020 Model to 2019 Mill Gold Production Reconciliation   ........................................... 14-32 January 2020 Valley of the   Kings Zone Mineral Resource   (1,2,3,4,5,6)......................................... 14-36 West Zone   Mineral Resource, April 2012 (Jones, 2012a)(1).....................................................   14-36 Comparison Between January 2020 and January 2019 Estimates for the   Valley of the Kings Zone Inside the Update Area Only   ............................................................ 14-38 Cut-off   Grade Costs....................................................................................................................   15-1 NSR Parameters   ........................................................................................................................   15-2 Main Valley of the Kings Zone Mining Thickness by Mining Block   ............................................ 15-3 Insitu Au Grade Cap for the   Mine Call Factor   ............................................................................   15-6 Average Insitu Gold Grade of Stopes Before and After Mine Call Factor   Application ............... 15-6 2019 Reserve Reconciliation vs. 2019 Mined   Actuals ............................................................. 15-10   2019 Reduction of Reserve Grade After Application of   MCF................................................... 15-10 Brucejack Gold   Mine Mineral Reserves(1,2,3,4) by Mining   Zone................................................. 15-11 Brucejack Gold   Mine Mineral Reserves(1,2,3,4) by Mining Block ................................................   15-12 Comparison of 2020 Mineral Reserves with Mined Actuals to Previous   Reserve(1,2) .............. 15-15 Development Design   Parameters...............................................................................................   16-5 Stope Design Parameters   ..........................................................................................................   16-7 LOM Paste Fill   Requirements...................................................................................................   16-13 Summary of Stage 2 UCS Results   ...........................................................................................   16-14 LOM Backfilling – Waste Rock and Mill Tailings   ...................................................................... 16-15   LOM Development Requirements   ............................................................................................   16-16 LOM Tonnes and Grades   .........................................................................................................   16-18 Rock Mass Parameters Summarized by Geotechnical Domain   .............................................. 16-19 Lateral Development   Minimum Ground Support Recommendations.......................................   16-23 Minimum In Ore Supplemental Ground Support   ...................................................................... 16-24   Stope Dimension and Dilution Guidelines   ................................................................................   16-25 Major Underground Development and Production Equipment List   .......................................... 16-26 Support Equipment List   ............................................................................................................   16-28 Table 14-3: Table 14-4: Table 14-5: Table 14-6: Table 14-7: Table 14-8:   Table 14-9: Table 14-10: Table 14-11: Table 14-12: Table 14-13: Table 14-14:   Table 14-15: Table 14-16 Table 14-17: Table 15-1: Table 15-2: Table 15-3:   Table 15-4: Table 15-5: Table 15-6: Table 15-7: Table 15-8: Table 15-9: Table   15-10: Table 16-1: Table 16-2: Table 16-3: Table 16-4: Table 16-5: Table   16-6: Table 16-7: Table 16-8: Table 16-9: Table 16-10: Table 16-11: Table   16-12: Table 16-13: x 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 16-14: Table 16-15:   Table 16-16: Table 17-1: Table 17-2: Table 17-3: Table 19-1: Table 20-1:   Table 20-2: Primary Fan   Specifications.......................................................................................................   16-32 2018 Propane   Consumption.....................................................................................................   16-50 Manpower by Operational Group .............................................................................................   16-54 Brucejack Mill Production Data 2019   .........................................................................................   17-2 Major Design Criteria ..................................................................................................................   17-4 Projected Gold and Silver Production   ......................................................................................   17-14 Gold and Silver Prices ................................................................................................................   19-1 List of Amendments to EAC #M-15-01   .......................................................................................   20-9 List of BC Major Authorizations, Licenses, and Permits Obtained to   Develop and Operate the Brucejack   Project..................................................................................................   20-11 List of Federal Approvals and Licenses Obtained to Develop and Operate   the Brucejack   Project......................................................................................................................   20-12 Average Monthly Climate Data for the Brucejack Gold Mine Site   ............................................ 20-15 Summary of Water   Withdrawal Data – Brucejack Creek, 2019   ............................................... 20-27 Summary of LOM   Expansion and Sustaining Capital Costs   ...................................................... 21-1 Foreign Exchange   Rates ............................................................................................................   21-1 LOM Mining Sustaining Capital Cost Summary   .........................................................................   21-2 Mining Sustaining Capital Costs by Year   ...................................................................................   21-3 Site Infrastructure Sustaining Capital Costs by Year   ................................................................. 21-4 LOM   Average Operating Cost   Summary....................................................................................   21-5 Cash Flow Results Summary (including Discounted Post-tax   NPV).......................................... 22-1 Metal Production   Quantities .......................................................................................................   22-3 Economic Results Summary for Different Metal Price Scenarios   .............................................. 22-5 LOM Taxes   Summary.................................................................................................................   22-6 February 2011 Snowfield Mineral Resource   ..............................................................................   23-1 March 2019 KSM Property Mineral Reserve ..............................................................................   23-5 March 2019 KSM Property Measured and Indicated Mineral Resources   .................................. 23-6 LOM Average Operating Cost   Summary....................................................................................   25-9 Brucejack Gold Mine Economic Performance   Forecast........................................................... 25-10   Table 20-3: Table 20-4: Table 20-5: Table 21-1: Table 21-2: Table 21-3: Table   21-4: Table 21-5: Table 21-6: Table 22-1: Table 22-2: Table 22-3: Table 22-4:   Table 23-1: Table 23-2: Table 23-3: Table 25-1: Table 25-2: LIST OF FIGURES   Figure 1-1: Figure 1-2: Figure 1-3: Figure 1-4: Figure 4-1: Figure 4-2:   Figure 4-3: Figure 5-1: Figure 6-1: Figure 7-1: Figure 7-2: Simplified   Process   Flowsheet.....................................................................................................   1-12 Brucejack Gold Mine On-site Infrastructure   Layout....................................................................   1-15 Brucejack Gold Mine Off-site Infrastructure   Layout....................................................................   1-16 Overall Operating Cost Distribution by Area   ..............................................................................   1-19 Brucejack Property Location Map   ................................................................................................   4-1 Brucejack Property Mineral Claims   ..............................................................................................   4-3 Pretivm Mineral   Claims.................................................................................................................   4-4 Project Access   ..............................................................................................................................   5-3 Visible Electrum in Valley of the Kings Zone Discovery Drillhole SU-012   ................................... 6-3 Regional Geological Setting of the   Brucejack Deposit .................................................................   7-2 Select Mineral Showings and Deposits in the Stewart-Iskut Culmination,   Highlighting the Metal-rich Nature of this   Structure................................................................................................   7-4 xi 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-3: District-scale   Geological Setting of the Brucejack Deposit on the East Side of the McTagg   Anticlinorium   ...................................................................................................................   7-5 Geological Map of the Brucejack Project Area Showing Location of   Mineralized Zones and their Association with the Band of Quartz-Sericite-Pyrite   Alteration (shown in yellow) ........ 7-7 Brucejack Property Geology Legend   for Figure 7-4   ..................................................................... 7-8   Three-dimensional Block Geological Interpretation Through the Brucejack Deposit,   Showing Key Geological, Structural, and Mineralization Relationships   Developed in the Valley of the Kings Zone and West Zone   ...................................................................................   7-11 Oblique View Down and Towards the West-Northwest of the Brucejack   Deposit Showing Drillhole Intersections Greater than 5 g/t Gold Relative to   Underground Workings in both the Valley of the Kings Zone and the West Zone   ....................................................................... 7-15   Mineralized Veins in the Valley of the Kings Zone of the Brucejack Deposit   ............................. 7-18 Schematic Section of Calc-alkaline   Volcanic Arc Showing High and Intermediate Sulphidation Epithermal Deposits   and Porphyry Deposits ...........................................................   8-3 Conceptual Model of Different Arc-related Porphyry and Epithermal   Copper-Gold-Silver Mineralization Deposits   ................................................................................................................   8-4 Plan View of the Brucejack Deposit Showing Significant Electrum   Intersections from the 2015 Surface Exploration Drilling of the Flow Dome   Zone .................................................... 9-4 Plan View of   1TEM Conductivity Data on the Western Edge of Pretivm’s Claim Block,   Illustrating the Potential Scale of the Hydrothermal System Footprint (Warmer   Colours) of which the Brucejack Deposit is a Part (also shown are Peripheral   Known Mineralized Zones on the Brucejack and Snowfield Properties and Drill   Trances From the 2015 Surface Exploration Drill Program)   ...............................................................................................   9-5 Cross Section of the Brucejack Deposit (Looking North) Showing Gold Assay   Intersections from the 2015 Surface Exploration Drilling and 2018 Underground   Deep Exploration Drilling of the Flow Dome Zone, as well as the Zone of   Anomalous Copper and Molybdenite   Assays......................................................................................................................   9-6 Plan View Part of the Brucejack Project Showing Location of the 2018   Frontier Geosciences Inc. Surface Reflection Seismic and IP Survey Lines   ............................... 9-7 Cross Section of the Brucejack Deposit   (Looking North) Showing Gold Assay Intersections from the 2015 Surface   Exploration Drilling and 2018–2019 Underground Deep Exploration Drilling   ........................................................................................   9-8 Cross Section (Looking West) of Quantec Geoscience Ltd. 2D CSMT Line   BJ19-03 Showing ‘Pipe-like’ Resistivity Low and Copper Assay Intersections   from 2015 Surface Exploration Drilling and 2018–2019 Underground Deep   Exploration Drilling ............... 9-10 Plan View Showing Location of the   2019 Frontier Geosciences Inc. Surface IP Survey Lines and Electrode   Locations   .......................................................................................   9-11 Plan View Showing the 17 and 50 ms Chargeability Isosurfaces from the   2019 Frontier Geoscience Inc. IP   Survey...................................................................................   9-12 Plan View Showing the 500 OHM-M Resistivity Isosurface from the 2019   Frontier Geoscience Inc. IP Survey...................................................................................   9-13 Plan View of Brucejack Property Drilling In and Around the Brucejack   Deposit ........................ 10-3 Plan View on the 1,140 m Level in the   Brucejack Gold Mine Showing 2019 Drilling and Valley of the Kings Zone   Mineralized Domain Interpretations (Viewing Window ±20 m) .......... 10-6   Figure 7-4: Figure 7-5: Figure 7-6: Figure 7-7: Figure 7-8: Figure 8-1:   Figure 8-2: Figure 9-1: Figure 9-2: Figure 9-3: Figure 9-4: Figure 9-5:   Figure 9-6: Figure 9-7: Figure 9-8: Figure 9-9: Figure 10-1: Figure 10-2: xii   

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 10-3: Example SW-NE   Cross Section Along Mining Crosscut 17 (Central Parts of the Mine) Showing   Workings, Drilling, and Mineralized Domain Interpretations in the Valley of   the Kings Zone of the Brucejack Deposit (Viewing Window ±20 m)   ........................... 10-7 Cumulative Stage GRG versus Grind Size for   Gold and Silver ................................................. 13-4 Bulk   Sample Process Flowsheet   ..............................................................................................   13-10 Gold Grains Distributions with Size Range   ..............................................................................   13-14 Gravity Results Summary – Composite Samples – ALS 2018   ................................................ 13-17 E-GRG Test Results   .................................................................................................................   13-18 Rougher Flotation Tests on Composite H and L   ...................................................................... 13-20   Rougher Flotation Tests on Composite M   ................................................................................   13-20 Cleaner Flotation Tests on Composite L, A, H, GH, WZ, and M   .............................................. 13-21 Locked Cycle Test   Flowsheet No. 1 .........................................................................................   13-22 Locked Cycle Test Flowsheet No. 2   .........................................................................................   13-23 Gravity and Flotation Optimization Tests .................................................................................   13-25 Concentrate Thickener Capacity   ..............................................................................................   13-27 Tailing Thickener Underflow Concentration with Time   ............................................................. 13-28 Plan View   of the Brucejack Deposit Showing the Location of the West Zone and Valley of   the Kings Zone (VOK) Resource Block Models, and the Defined Update Areas (and   Dates) .................................................................................................................................   14-2 Topography and Lithological Wireframes used in the Generation of the   January 2020 Resource Estimate (shown in Maptek’s Vulcan Mining Software): a)   Plan View of Topography Draped with Aerial Photography; b) Plan View Showing   Lithological Model Triangulations and Approximate Location of Cross Section;   c) S-N Cross-Section Along 426525 mE   (A-A’).............................................................................................................   14-6 Plan View of Mineralized Domain Triangulations Used in the Generation of   the January 2020 Mineral   Resource.................................................................................................   14-8 N-S Cross Section Along 426635 mE of Mineralized Domain Triangulations   Used in the Generation of the January 2020 Mineral Resource   ................................................................... 14-8 Plan   View Showing the Main Grouped Valley of the Kings Zone Mineralized Domains   (Bigdom) Used in the Generation of the January 2020 Mineral Resource   ................................ 14-9 Plan View Showing Model Update Area   Solid (Purple) and Drillholes (White) from the 2019 Infill Drill   Campaign..........................................................................................................   14-10 Log Probability Plots of a) Gold and b) Silver Composited Data Inside   the Valley of the Kings Zone Mineralization Domains - January 2020 Update   Area. .................... 14-12 Log-Normal Histogram Plot of a) Gold and b)   Silver Composited Data Inside the 2019 Updated Area Mineralization   Domains............................................................................   14-13 Example of Modelling the Upper Tail of the a) High-Grade Gold and b)   High-Grade Silver Populations Using a Hyperbolic Model. Data Shown for Bigdom   600. .......................... 14-23 Example Gold Grade Trend Plots by   Easting for Bigdom 600 .................................................   14-26 Example Gold Grade Trend Plots by Northing for Bigdom 600   ............................................... 14-27 Example Gold Grade   Trend Plots by Elevation for Bigdom 600   .............................................. 14-27 Example Silver Grade   Trend Plots by Easting for Bigdom   600................................................ 14-28 Example Silver   Grade Trend Plots by Northing for Bigdom 600   .............................................. 14-28 Example Silver Grade   Trend Plots by Elevation for Bigdom 600   ............................................. 14-29 Figure 13-1: Figure 13-2:   Figure 13-3: Figure 13-4: Figure 13-5: Figure 13-6: Figure 13-7: Figure 13-8:   Figure 13-9: Figure 13-10: Figure 13-11: Figure 13-12: Figure 13-13: Figure   14-1: Figure 14-2: Figure 14-3: Figure 14-4: Figure 14-5: Figure 14-6: Figure   14-7: Figure 14-8: Figure 14-9: Figure 14-10: Figure 14-11: Figure 14-12:   Figure 14-13: Figure 14-14: Figure 14-15: xiii 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-16: Plan View of   the 1180 m Level Showing Block Grade Estimates and Input Drillhole Composite   Data Colour Coded by Gold Grade ........................................................................   14-30 N-S Cross Section Along 426300 E Showing Block Grade Estimates and   Input Drillhole Composite Data Coloured by Gold   Grade.................................................................. 14-31   Ounces Normalized to Mill Production with Corresponding Drillhole Spacing   Plot for the January 2020 Model   .................................................................................................................   14-33 January 2020 Valley of the Kings Zone Measured + Indicated Mineral   Resource   Sensitivity..................................................................................................................................   14-37 Population Variance of Au Grade within the 2020 Reserves Based on Diamond   Drillhole   Spacing.........................................................................................................................   15-5 Distribution of Average Insitu Au Grade of Reserves Before Mine Call   Factor Application ....... 15-6 Distribution of Average Insitu Au Grade of   Reserves After Mine Call Factor Application .......... 15-7 Sources of Stope   Dilution   ...........................................................................................................   15-9 Reserve Shapes and Mining Blocks in the Main Valley of the Kings   Zone.............................. 15-13 Reserve Shapes and Mining Blocks in   the West Zone ............................................................   15-14 Combined Reserves, Looking West .........................................................................................   15-14 Mine Access and Development   Infrastructure............................................................................   16-2 Brucejack Ramp System – Perspective View ............................................................................   16-3 Valley of the Kings Zone Sublevel Arrangement – Long   Section............................................... 16-4 Typical Level   Development – Valley of the Kings Zone .............................................................   16-5 Standard Designs – General Layout for All   ................................................................................   16-6 MSO Stope Shapes – VOK Zone   ...............................................................................................   16-8 MSO Stope Shapes – West Zone   ..............................................................................................   16-9 Typical LHOS Design   ...............................................................................................................   16-11 Example of Primary/Secondary LHOS at Brucejack Gold   Mine............................................... 16-12 LOM Production   Schedule by Mining Horizon..........................................................................   16-17 LOM Production Schedule by Activity   ......................................................................................   16-17 Oblique View of the Interpreted Mine-scale Faults at the Brucejack Area   Looking Approximately South   ................................................................................................................   16-20 Brucejack Gold Mine Ventilation System (Looking West)   ........................................................ 16-30 Typical   Production Level   ..........................................................................................................   16-32 Conveyor Fire   Isolation.............................................................................................................   16-34 Dewatering Plan   .......................................................................................................................   16-37 Tipple and Ore Bin Sectional   Projection...................................................................................   16-38 Crusher Feed and   Crusher.......................................................................................................   16-39 Underground Power Requirement Profile   ................................................................................   16-40 West Zone Portal Underground Single-line Diagram   ............................................................... 16-42   Borehole Underground Single-line   Diagram.............................................................................   16-43 ESS Feed to 1080 Single-line   Diagram....................................................................................   16-44 Mine Service Water Distribution Schematic   .............................................................................   16-45 Bulk Emulsion/Powder Magazine Storage Plan   ....................................................................... 16-47   Permanent Refuge Station   .......................................................................................................   16-48 Paste Fill Distribution System Schematic Showing Paste Pumping Zones   ............................. 16-52 Paste Fill Distribution System Schematic   .................................................................................   16-53 Simplified Process   Flowsheet.....................................................................................................   17-3 Figure 14-17: Figure 14-18: Figure 14-19: Figure 15-1: Figure 15-2:   Figure 15-3: Figure 15-4: Figure 15-5: Figure 15-6: Figure 15-7: Figure 16-1:   Figure 16-2: Figure 16-3: Figure 16-4: Figure 16-5: Figure 16-6: Figure 16-7:   Figure 16-8: Figure 16-9: Figure 16-10: Figure 16-11: Figure 16-12: Figure   16-13: Figure 16-14: Figure 16-15: Figure 16-16: Figure 16-17: Figure 16-18:   Figure 16-19: Figure 16-20: Figure 16-21: Figure 16-22: Figure 16-23 Figure   16-24: Figure 16-25: Figure 16-26: Figure 16-27: Figure 17-1: xiv 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 18-1: Figure 18-2:   Figure 18-3: Figure 18-4: Figure 18-5: Figure 18-6: Figure 20-1: Figure 20-2:   Figure 21-1: Figure 21-2: Figure 21-3: Figure 22-1: Figure 22-2: Figure 22-3:   Figure 23-1: Brucejack Gold Mine General   Arrangement...............................................................................   18-2 Brucejack Gold Mine On-site Infrastructure Layout....................................................................   18-3 Brucejack Gold Mine Off-site Infrastructure   Layout....................................................................   18-4 Knipple Transfer Station   ...........................................................................................................   18-15 Bowser Aerodrome   ...................................................................................................................   18-16 Wildfire Camp ...........................................................................................................................   18-18 Observed and Simulated Inflow to Underground Workings for Selected   Model Scenarios ..... 20-23 Brucejack Gold Mine Water Balance Flow Schematic   – Operations ....................................... 20-28 Overall Operating   Cost Distribution by Area   ..............................................................................   21-5 Mining Operating Cost Distribution by Area   ...............................................................................   21-6 Process Operating Cost Distribution by   Area.............................................................................   21-7 Pre-tax Cash Flow   ......................................................................................................................   22-4 Post-tax NPV Sensitivity to Metal Prices   ....................................................................................   22-8 Post-tax NPV Sensitivity to Operating   Costs..............................................................................   22-9 Detailed Geological Map of KSM-Brucejack Area and McTagg Anticlinorium   and Section Locations   .......................................................................................................................   23-3 Legend for Detailed Geological Map of KSM-Brucejack Area and McTagg   Anticlinorium and Section Locations   ................................................................................................................   23-4 Simulated vs. Observed Inflow Rates   ........................................................................................   25-6 Figure 23-2: Figure 25-1: ACRONYMS & ABBREVIATIONS xv   Acronyms/Abbreviations Definition .csv Comma Separated Values .pdf Portable   Document Format AA Atomic Absorption AAS Atomic Absorption Spectroscopy ABA   Acid Base Accounting AES Atomic Emission Spectroscopy Ag Silver AI Bond   Abrasion Index ALS Global ALS AMC AMC Mining Consultants (Canada) Ltd. AMT   Audio Magnetotelluric APS Aluminum Phosphate Sulphate Minerals Apy   Arsenopyrite Ar-Ar Argon-argon ARD Acid Rock Drainage As Arsenic 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xvi Acronyms/Abbreviations   Definition ASP Avalanche Safety Plan Au Gold AuEq Gold Equivalent BC British   Columbia BCEAA BC Environmental Assessment Act BCMWRP British Columbia Mine   Waste Rock Pile Research Committee BD Bulk Density BGC BGC Engineering Inc.   Bi Bismuth Black Hawk Black Hawk Mining Inc. Brucejack Deposit The Brucejack   Gold-Silver Deposit BV Bureau Veritas Commodities Canada Ltd. BWi Bond Ball   Mill Work Index BZ Bridge Zone Cal Calcite CCTV Closed-circuit Television CDE   Canadian Development Expense CEA Cumulative Expenditures Account CEAA   Canadian Environmental Assessment Act CEE Canadian Exploration Expense Chl   Chlorite CIM Canadian Institute of Mining, Metallurgy and Petroleum CMS   Cavity Monitoring System CNCF Cumulative Net Cash Flow Corona Corona   Corporation Cpy Chalcopyrite CSS Contact Support Service Inc. CTCA Cumulate   Tax Credit Account Cu Copper CV Coefficient of Variation CWi Bond Crushing   Work Index CWP Contact Water Pond DCS Distributed Control System 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xvii Acronyms/Abbreviations   Definition DDH SPC Drillhole Spacing DO Dissolved Oxygen Dol Dolomite DPS   Diesel Power Station DTM Digital Terrain Model DWi Drop Weight Index EAC   Environmental Assessment Certificate EAO Environmental Assessment Office EDS   Energy Dispersive Spectrometer EGL Effective Grinding Length E-GRG Extended   Gravity Recoverable Gold EIS Environmental Impact Statement El Electrum EMS   Environmental Management System EOR Engineer of Record ERM Environmental   Resources Management ESEMP Economic and Social Effects Mitigation Plan ESS   Electrical Substation Service Esso Esso Minerals Canada Ltd. FA Fly-ash   FLS-DM FLSmidth Dawson Metallurgical FOS Factor of Safety FS Feasibility Study   FW Freshwater G&A General and Administrative Gekko Gekko Systems Pty Ltd.   GeoSpark GeoSpark Consulting Inc. GeoSpark Core GeoSpark Core Microsoft®   Access front-end interface GH Galena Hill GIS Geographical Information System   Gn Galena GP General Purpose GPS Global Positioning System 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xviii Acronyms/Abbreviations   Definition Granduc Granduc Mines Ltd. GRG Gravity Recoverable Gold GSI   Geological Strength Index Hazen Hazen Research Inc. HDPE High-density   Polyethylene Hg Mercury HGT High-grade Threshold HPGR High-pressure Grinding   Roll HSE Health, Safety and Environmental HSRCM Healthy, Safety and   Reclamation Code for Mines in British Columbia HVAC Heating, Ventilation and   Air Conditioning HW Hanging Wall Hy-Tech Hy-Tech Drilling Limited ICP   Inductively Coupled Plasma IK Indicator Kriging IMC Information Management   Center Inspectorate Inspectorate Exploration and Mining Services Ltd. IP   Induced Polarization ISO International Organization for Standardization IT   Information Technology JonesPL Ivor Jones Pty Ltd JV Joint Venture K-Ar   Potassium-argon Knelson FLSmidth Knelson Krebs Krebs-FLSmidth KSM   Kerr-Sulphurets-Mitchell Lancana Lancana Mining Corp. LBMA London Bullion   Market Association LHD Load-Haul-Dump LHOS Long-hole Open Stoping LIDAR Light   Detection and Ranging LNG Liquefied Natural Gas LOM Life-of-Mine 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xix Acronyms/Abbreviations   Definition Lorax Lorax Environmental Services Ltd. LRMP Land and Resource   Management Plan MC MineCem MCC Motor Control Center MCF Mine Call Factor   MDMER Metal and Diamond Mining Effluent Regulation MEMPR Ministry of Energy,   Mines & Petroleum Resources Metso Metso Corporation Met-Solve Met-Solve   Laboratories Inc. MFLNRORD Ministry of Forests, Lands and Natural Resource   Operations and Rural Development MIK Multiple Indicator Kriging ML/ARD Metal   Leaching / Acid Rock Drainage Mo Molybdenum MSALabs MS Analytical MSO   Mineable Shape Optimizer MT Magnetotelluric MTO Mineral Titles Online NaCN   Sodium Cyanide NAD North American Datum NCF Net Cash Flow Newhawk Newhawk   Gold Mines Ltd. NI 43-101 National Instrument 43-101 NPAG Non-PAG NPR   Neutralization Potential Ratio NPV Net Present Value NSR Net Smelter Return   OK Ordinary Kriging OMS Operations, Maintenance and Surveillance PAG   Potentially Acid Generating PAX Potassium Amyl Xanthate Pb Lead PD Positive   Displacement PEA Preliminary Economic Assessment 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xx Acronyms/Abbreviations   Definition Placer Dome Placer Dome Inc. PLC Programmable Logic Controller PMA   Particle Mineral Analysis PMCL Process Mineralogical Consulting Ltd. Pocock   Pocock Industrial Inc. Pretivm Pretium Resources Inc. Procon Procon Mines and   Tunneling PRV Pressure Reducing Valves Py Pyrite QA Quality Assurance QC   Quality Control QEMSCAN Quantitative Evaluation of Materials by Scanning   Electron Microscopy QP Qualified Person QPO Quantifiable Performance   Objectives Qz Quartz RC Reverse Circulation REF-ET Reference   Evapotransiration Re-Os Rhenium-osmium RMS RMS Corp. ROM Run-of-Mine RQD Rock   Quality Designation Rt Rutile RWi Bond Rod Mill Work Index S Sulphur SABC SAG   Mill / Ball Mill / Pebble Crushing SAG Semi-autogenous Grinding Sb Antimony   SBT Stewart Bulk Terminal SCADA Supervisory Control and Data Acquisition SCSE   SAG Circuit Specific Energy Seabridge Gold Seabridge Gold Inc. SEM Scanning   Electron Microscope Ser Sericite 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xxi Acronyms/Abbreviations   Definition SFA Screen Fire Analysis SG Specific Gravity SGS SGS Canada Inc.   Silver Standard Silver Standard Resources Inc. SIPX Sodium Isopropyl Xanthate   SLS Solid Liquid Separation SMC SAG Mill Comminution Sn Tin SNF SNF Canada   SOP Standard Operating Procedure Sp Sphalerite SPI SAG Power Index SQL   Structured Query Language SRK SRK Consulting (Canada) Inc. SRMP Sustainable   Resource Management Plan SS Sunset Slag Blend Strategic Minerals Strategic   Minerals LLC Tetra Tech Tetra Tech Canada Inc. TIMA Tescan Integrated Mineral   Analyzer TK/TU Traditional Knowledge / Traditional Use TMS Trace Mineral   Search TSS Total Suspended Solids UCS Universal Compressive Strength UDS   Underground Distribution System UKAS United Kingdom Accreditation Service UPS   Uninterruptible Power Supply UTM Universal Transverse Mercator UV Ultraviolet   VFD Variable Frequency Drive VG Visible Gold VHF Very-high Frequency VMS   Volcanogenic Massive Sulphide VoIP Voice Over Internet Protocol 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE xxii Acronyms/Abbreviations   Definition VOK Valley of the Kings VSF Volcanosedimentary VSI Vertical Shaft   Impactor W Tungsten WAC Wildlife Advisory Committee WAP Wireless Access Point   Wardrop Wardrop Engineering Inc. WBS Work Breakdown Structure WQG Water   Quality Guidelines WRTSF Waste Rock Tailings Storage Facility WTP Water   Treatment Plant WZ West Zone XRD X-ray Diffraction Zn Zinc 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.1 Introduction The   Brucejack Gold Mine, located in northwest British Columbia (BC), is a   high-grade underground mining operation that commenced commercial production   in July 2017. The Brucejack Gold Mine uses conventional gravity concentration   and sulphide flotation to produce gold (Au)-silver (Ag) doré and gold-silver   flotation concentrate. Pretium Resources Inc. (Pretivm), a low-cost intermediate   gold producer, owns 100% of the Brucejack Property. In 2014, prior to mine   construction and the start of operations, Pretivm commissioned a team of   consultants to complete a Feasibility Study (FS) update for the Brucejack   Project in accordance with National Instrument 43-101 (NI 43-101) Standards   of Disclosure for Mineral Projects, the NI 43-101 Companion Policy, and Form   43-101F1 (Ireland et al. 2014). In 2019 Pretivm released an updated NI 43-101   Technical Report which updated the operating parameters considered in the   2014 FS to assess the potential of increasing the mine and process plant   throughput from 2,700 to 3,800 t/d. That assessment incorporated six quarters   of mining operation information from the Brucejack Gold Mine. In January 2020,   Pretivm commissioned Tetra Tech Canada Inc. (Tetra Tech) and other   consultants to complete an update to the 2019 NI 43-101 Technical Report.   This NI 43-101 Technical Report, effective on March 9, 2020, updates the   Mineral Resource and Mineral Reserve, the Life of Mine (LOM) plan, and   operating parameters. The effective date of the 2020 Mineral Reserve and 2020   Mineral Resource is January 1, 2020. The following consultants were   commissioned to complete work and reviews for the purpose of the Technical   Report: Tetra Tech – mineral processing and metallurgical testing, mineral   reserve estimates, mining methods, recovery methods, project surface and   underground infrastructure, market studies and contracts, capital and   operating cost estimates, and economic analysis.  Ivor Jones Pty Ltd – property description   and location; accessibility, climate, and physiology; history; geological   setting and mineralization; deposit types; exploration; drilling; sample   preparation and analysis; data verification; adjacent properties; and mineral   resource estimates.  Environmental   Resources Management (ERM) – aspects of environmental studies, permits, and   social or community impacts; waste management; and closure plans.  Lorax Environmental Services Ltd. (Lorax) –   hydrogeology, geochemistry, water balance, and water quality.  SRK Consulting (Canada) Inc. (SRK) – waste   rock and tailings storage facility, underground and surface geotechnical   design, and water management.  The   effective date of the Mineral Resource and Mineral Reserve estimates is   January 1, 2020 and the effective date of this Technical Report is March 9,   2020. 1-1 1.0SUMMARY 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.2 Property Description and   Location The Brucejack Property is centered approximately at 56°2820N   Latitude by 130°1131W Longitude, a position approximately 950 km northwest of   Vancouver, 65 km north-northwest of Stewart, and 21 km south-southeast of the   Eskay Creek Mine in the Province of BC. The Brucejack Property consists of   four mining leases and six mineral claims that cover the target Mineral   Resource, totaling 3,305.85 ha in area. All mining leases are in good   standing until September 17, 2020; all mineral claims are in good standing   until January 31, 2031. The Brucejack Property and the surrounding region   have a history rich in exploration for precious and base metals dating back   to the late 1800s. More recently in 2010, Silver Standard Resources Inc. (Silver   Standard), pursuant to a purchase and sale agreement between Silver Standard   (as the seller) and Pretivm (as the buyer), sold to Pretivm all of the issued   shares of 0890693 BC Ltd., the owner of the Brucejack Project and the   adjacent Snowfield Project. Subsequently, the name of 0890693 BC Ltd. was   changed to Pretium Exploration Inc. 1.3 Geology and Mineralization The   Brucejack Deposit is currently defined as incorporating the Valley of the   Kings Zone and the West Zone. Similar epithermal vein-hosted precious metal   mineralization is present throughout the 5 km by 1.5 km wide arcuate band of   phyllic alteration on the Brucejack Property (e.g., Gossan Hill Zone, Shore   Zone, SG Zone, Golden Marmot Zone, and Hanging Glacier Zone). This alteration   and mineralization band has yet to be explored in sufficient detail for   resource estimation, and represents upside potential on the property. The   Brucejack Deposit is located on the western side of the Stikine Terrane in   the Intermontane morphogeologic belt of the Canadian Cordillera. The   Brucejack Deposit occurs in an exceptionally metals-rich tectonic assemblage   hosted in volcanic island arc-related rocks of the Lower Jurassic Hazelton   Group in BCs Golden Triangle. At the district level, the Brucejack Deposit forms   part of a well mineralized, north-south gossanous trend (the Sulphurets   Mineral District) associated with a regional unconformity and proximal   mineralized Early Jurassic porphyry intrusions on the eastern limb of the   McTagg Anticlinorium. Rocks of the Sulphurets Mineral District record a long   history of volcanism, telescoping magmatic-hydrothermal alteration,   mineralization, and deformation. The Brucejack Deposit is interpreted to be a   deformed, porphyry-related transitional to intermediate sulphidation epithermal   high-grade gold-silver deposit that was formed between 184 to 183 Ma in an   active island arc setting similar to the modern-day Philippines. Intermediate   sulphidation epithermal deposits are considered to be a sulphide-rich   sub-type of carbonate-base metal gold deposits, of which there are numerous   examples in the southwest Pacific Rim region. High-grade gold-silver   mineralization was formed in association with a telescoped, multi-pulsed   magmatic-hydrothermal system beneath an active local volcanic center. The   high-grade precious metal mineralization appears to have been predominantly   transported as colloidal suspensions, the destabilization of which during   fluid mixing resulted in the ubiquitous yet highly locally variable   distribution of gold and silver mineralization in the Brucejack Deposit.   Precious metal precipitation from the colloidal suspension appears to have   been concentrated along structural corridors within broader stockwork zones,   including along faults, fractures, pre-existing foliation planes, and   lithological contacts. Within the structural corridors the high-grade   precious metal mineralization occurs as coarse dendritic aggregates of   electrum and silver sulfosalts, largely hosted in steeply dipping,   east-trending quartz-carbonate to carbonate veins and vein breccia. The   occurrence of structural corridors of higher-grade east-west mineralization   within the broader stockwork zones represents an opportunity for longitudinal   mining. The high-grade epithermal veins co-spatially overprint low-grade   intrusion-related phyllic alteration. Epithermal vein development is   interpreted to have occurred during the waning stages of Early Jurassic   sinistral transpression in a compressive arc environment, followed by a   limited Cretaceous deformation overprint. 1-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE There is a distinct precious   metal zonation between the Valley of the Kings Zone, which contains higher   gold grades, and the West Zone, which is significantly more silver rich. The   Valley of the Kings Zone is currently defined over 1,200 m in east-west   extent, 700 m in north-south extent, and 650 m in depth, and remains open to   the east, west, and at depth. The West Zone is currently defined over 590 m   along its northwest strike, 560 m across strike, and down to 650 m in depth,   and remains open to the northwest, southeast, and at depth to the northeast.   Brownfields exploration drilling conducted from within the Brucejack Gold   Mine targeting the Flow Dome Zone and beneath the West Zone demonstrated the   continuation of Valley of the Kings Zone style mineralization to the   northeast, southeast, and 550 m in depth below the current resource. CSMT   geophysical surveys reprocessed by Quantec Geoscience Ltd. in 2019 prompted   deep exploration drilling focused on targeting a conductivity anomaly beneath   the West Zone deposit to test for the source porphyry responsible for driving   the epithermal mineralization in the Brucejack Deposit. Anomalous copper and   porphyry-style alteration were identified at depth. Follow-up drilling is   currently being conducted. More than 40 mineralization showings, at least   eight of which are currently considered as mineralized zones (e.g., Bridge   Zone, Waterloo Zone, Flow Dome Zone, Gossan Hill Zone, Shore Zone, SG Zone,   Golden Marmot Zone, and Hanging Glacier Zone), are recognized in this band.   The alteration and mineralization band has yet to be explored in sufficient   detail for mineral resource estimation and represents upside potential on the   Brucejack Property. 1.4 Mineral Resource Estimates 1.4.1 Drilling, Sampling,   Assaying, and Data Verification The updated drillhole database provided to   the resource team to support this update built upon the database provided for   Jones et al. (2019) and included an additional 555 HQ diamond drillholes for   a total of 89,121 additional drilled metres, and at the time of cut-off   represented 86,719 m of new assay data. Whole core samples were sent to the ALS   Global (ALS) facility in Terrace, BC for sample preparation. Analysis was   completed by the ALS Vancouver laboratory in North Vancouver, BC. Secondary   lab checks were completed at MS Analytical in Langley, BC. Pretivm’s quality   assurance (QA) / quality control (QC) protocols for the Brucejack Deposit   included tests for data accuracy, precision, and sample cross-contamination   using duplicates (coarse and pulp duplicates), coarse blanks, and certified   standards. Additional coarse blank samples were inserted immediately   following samples with logged visible gold to quantify and avoid any   potential cross-contamination between samples during laboratory sample   preparation. QA/QC assay data checks were completed on a regular basis by the   Database Manager. Pulp checks were requested where certified standard samples   had 3SD accuracy fails in Au mineralized areas. Re-assay results from QA/QC   checks were imported and assigned precedence in the database. QA/QC reporting   was completed in-house by the database manager and reviewed by the Qualified   Person (QP). The QA/QC analysis indicated acceptable levels of accuracy and   precision, similar to previous years. The QP, Mr. I.W.O. Jones, P.Geo.,   FAusIMM has conducted sufficient data and underground verification checks to   satisfy himself that the drilling, core logging, sample handling, assaying,   and data QA/QC procedures were conducted using industry best practices and   that the data generated were of suitable quality for use in resource   modelling and estimation of the Brucejack Deposit. Furthermore, Mr. Jones   considers the geological interpretation to be appropriate and representative   of the mineralization in the Brucejack Deposit. 1-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.4.2 Mineral Resource   Estimation An updated Mineral Resource, with an effective date of January 1,   2020, has been prepared for the Brucejack Deposit, incorporating information   from additional tightly-spaced infill drilling, mapping of underground   geological exposures, and mine production. The updated resource estimate is   presented for the combined Valley of the Kings Zone and the West Zone in   Table 1-1 and separately for the Valley of the Kings Zone in Table 1-2 and   the West Zone in Table 1-3. The new resource estimate comprises that part of   the Valley of the Kings Zone where new information was available; the January   2019 resource estimates for the Valley of the Kings Zone (Jones et al., 2019)   and the December 2013 resource estimates for the Valley of the Kings Zone   (Jones 2014) are retained outside the update area and the April 2012 resource   estimate is retained for the West Zone (Jones 2012). The January 2020 Mineral   Resource inside the update area is reported inclusive of Mineral Reserves and   exclusive of material mined to December 31, 2019. At the time of this report,   the QP for the Mineral Resource Mr. I.W.O. Jones, P.Geo., FAusIMM was not   aware of any environmental, permitting, legal, title, taxation, socio-economic,   marketing, political, or other relevant factors that could materially affect   the Mineral Resource presented in this Technical Report or its potential   development. The January 2020 Mineral Resource was estimated using the same   methodology as for previous resource estimates for the Brucejack Deposit. The   non-linear split population-based approach used is a similar one to that used   in earlier estimates and is currently considered the most appropriate method   for estimating the mixed and positively-skewed precious metal mineralization   for the Brucejack Deposit. The model was validated against input drillhole   data and mine production for the year 2019 and found to provide a reasonable   to good representation of the input data and production information: the   tonnes and grade reported by production in 2019 were within 10% of those   reported from the January 2020 resource model from within the mined outlines.   The resource model was classified as Measured, Indicated, and Inferred in   accordance with the Canadian Institute of Mining, Metallurgy and Petroleum   (CIM) (2014) Definition Standards. Measured Resources are expected to be   within 15% of mine production on a quarterly production basis and Indicated   Resources are expected to be within 15% of mine production on an annual   production basis. Shorter-term reconciliation is not considered appropriate   given the highly variable and nuggety nature of the precious metal   mineralization at Brucejack. The January 2020 resource estimate effectively   overwrites the January 2019 resource estimate inside the update area.   Comparisons between these models show that the new estimate (only that part   inside the update area and not accounting for depletion by mining) is lower   by approximately 0.7 Mt, 2.2 Moz Au, and 1.1 Moz Ag in the Measured +   Indicated Resource at similar estimated gold and silver grades, using the   same cut-off grade of 5 g/t AuEq (AuEq = Au + Ag / 53). The differences   between the two models are largely data-driven. Additional tightly-spaced   infill drilling, increased exposure of the mineralized system during mining,   and over 1.5 Mt of actual production since mine commissioning have resulted   in improved domain and local estimation parameter definition. 1-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE January 2020 Valley of the   Kings Zone and West Zone Mineral Resource(1,2,3,4,5,6) Table 1-1: Notes:   (1)Mineral Resources that are not Mineral Reserves do not have demonstrated   economic viability. The estimate of Mineral Resources may be materially   affected by environmental, permitting, legal, title, taxation,   socio-economic, marketing, political, or other relevant issues. The Mineral   Resources in this Technical Report were estimated and reported using the CIM   Definition Standards – Prepared by the CIM Standing Committee on Reserve   Definitions, Adopted by CIM Council May 10, 2014. (CIM, 2014). (2)The   quantity and grade of reported Inferred Resources in this estimation are   uncertain in nature and there has been insufficient exploration to define   these Inferred Resources as an Indicated or Measured Mineral Resource and it   is uncertain if further exploration will result in upgrading them to an Indicated   or Measured Mineral Resource category. (3)Contained metal and tonnes figures   in totals may differ due to rounding. (4)Resources depleted for production to   December 31, 2019. (5)The January 2020 Valley of the Kings Zone Mineral   Resource is reported above a gold cut-off grade of 3.5 g/t gold. The West   Zone Mineral Resource is reported above a cut-off grade of 5 g/t gold   equivalent (AuEq) (where AuEq=Au+Ag/53 as per previous models). (6)Mineral   Resource is reported inclusive of Mineral Reserve. January 2020 Valley of the   Kings Zone Mineral Resource(1) Table 1-2: (1)Notes from Table 1-1 apply.   Note: West Zone Mineral Resource, April 2012(1,2) Table 1-3: Note:(1)Notes   from Table 1-1 apply (see Jones (2012a) for more details) (2)Contained metal   and tonnes figures in totals may differ due to rounding. Source: Jones   (2012a) 1-5 Category Tonnes (Mt) Au (g/t) Ag (g/t) Contained Au (Moz)   Contained Ag (Moz) Measured 2.4 5.9 347 0.5 26.8 Indicated 2.5 5.9 190 0.5   15.1 Measured + Indicated 4.9 5.9 267 0.9 41.9 Inferred 4.0 6.4 82 0.8 10.6   Category Tonnes (Mt) Au (g/t) Ag (g/t) Contained Au (Moz) Contained Ag (Moz)   Measured 2.3 10.5 12.6 0.8 0.9 Indicated 16.1 11.4 12.2 5.9 6.3 Measured +   Indicated 18.4 11.3 12.2 6.7 7.2 Inferred 5.4 13.3 15.9 2.3 2.8 Category Tonnes   (Mt) Au (g/t) Ag (g/t) Contained Au (Moz) Contained Ag (Moz) Measured 4.7 8.4   183.3 1.3 27.7 Indicated 18.6 10.7 35.8 6.4 21.4 Measured + Indicated 23.2   10.1 65.5 7.6 49.1 Inferred 9.4 10.3 44.3 3.1 13.4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.5 Mineral Reserve Estimates   A net smelter return (NSR) cut-off value of US$180/t or Cdn$230/t ore was   used to define the Mineral Reserves. This cut-off value decreased from the   previous value of US$185/t ore used in the 2019 Technical Report. The NSR for   each block in the Mineral Reserve model was calculated as the payable revenue   for gold and silver, less the costs of refining, concentrate treatment,   transportation, assays, consultants, penalties, and insurance. The metal   price assumptions associated with the NSR value are US$1,250/oz Au and   US$15.6/oz Ag. A foreign exchange rate of Cdn$1.00:US$0.78 was used. The   dilution factors used in the Mineral Reserve were calculated from standard   overbreak assumptions, based on Pretivm’s experience and benchmarking of   other long-hole open-stoping (LHOS) operations. The overall LOM recovery is   estimated to be 94%, with a dilution of 12%.   TheMineralReservesweredevelopedfromtheMineralResourcemodel“res1912_MRM_NSC_   2019_depl_101010_MO_OW_Reserve”, which was created by Pretivm and provided to   Tetra Tech in January 2020. The orebody consists of numerous lenses in the   Valley of the Kings Zone and two distinct lenses in the West Zone (Table   1-4). These mineral reserves are exclusive of material mined prior to January   1, 2020. Mineral Reserves stated herein are calculated inclusive of a Mine   Call Factor (MCF). The MCF is a grade reconciliation calculation applied to   individual stopes and is based on the average drillhole spacing in each   stope. Each stope has been re-evaluated using both the reserve stope grade   and the drillhole spacing to account for potential overestimation in grade in   areas with lower average drillhole spacing. Grades are capped relative to the   concentration of drilling in the stope, with areas of closer drillhole   spacing, and therefore higher confidence, allocated a higher-grade cap than   those areas with fewer drillholes. The 2020 Mineral Reserve reflects a   reduction in gold grade from the 2019 Mineral Reserve grade due to updates to   the Mineral Resource and the application of a MCF. Brucejack Gold Mine   Mineral Reserves(1,2) by Mining Zone and Reserve Category, Effective January   1, 2020 Table 1-4: Notes: (1)Rounding of some figures may lead to minor   discrepancies in totals. (2)Based on US$180/t cut-off grade, US$1,250/oz Au   price, US$15.6/oz Ag price, and a Cdn$1.00:US$0.78 foreign exchange rate. 1-6   Zone Ore Tonnes (Mt) Grade Contained Metal Au (g/t) Ag (g/t) Au (Moz) Ag   (Moz) Valley of the Kings Zone Proven 1.4 8.9 11.1 0.4 0.5 Probable 11.3 8.7   9.8 3.2 3.6 Total 12.8 8.8 10.0 3.6 4.1 West Zone Proven 1.4 7.2 383.0 0.3   17.4 Probable 1.5 6.5 181.0 0.3 8.6 Total 2.9 6.8 278.5 0.6 26.0 Total Mine   Proven 2.8 8.1 195.1 0.7 17.9 Probable 12.8 8.5 29.8 3.5 12.2 Total 15.7 8.4   59.6 4.2 30.1 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.5.1 Mineral Reserve   Comparison As significant material has been mined between the 2020 Mineral   Reserves and the 2019 Mineral Reserves Update, a direct comparison of   reserves will not provide an accurate assessment of the changes made. To   provide a valid comparison, the inclusion of the mined-out material between   these two time periods needs to be added. As the 2020 Mineral Reserves are exclusive   of all material mined prior to January 1, 2020 and the 2019 Mineral Reserves   were exclusive of all material mined prior to January 1, 2019, the addition   of the reconciled 2019 milled actuals should provide a valid comparison.   Table 1-5 shows the comparison. Table 1-5: Comparison of 2020 Mineral   Reserves with Mined Actuals to 2019 Reserves The combined 2020 Mineral   Reserves and 2019 Milled Actuals total ore tonnes exceed the 2019 Mineral   Reserves due to two main factors: the mining of out-of-reserve material that   was identified as being economic by the grade control program, and the   increase in profitability of the NSR model. With these additions, the   combined 2020 Mineral Reserves with 2019 Milled Actuals contain more tonnes   at a lower grade than the 2019 Mineral Reserves. This results in a decrease   in overall ounces primarily due to a decrease in overall grade of the updated   portion of the resource. 1.6 Mining Methods The updated underground mine   design supports the extraction of 3,800 t/d of ore through a combination of   transverse and longitudinal LHOS. Closely matching the previously stated plan   disclosed in the 2014 FS (Ireland et al. 2014) and the 2019 FS Update (Tetra   Tech), paste backfill and trackless mobile equipment will be employed in the   majority of mining activities. Access to the mine is via the Valley of the   Kings decline, situated near the concentrator. The Valley of the Kings   decline is also utilized as a conveyor way, with two conveyors installed at a   combined length of 800 m. The existing West Zone portal provides the main   access for large underground equipment and waste haulage. Development   initiated during the two pre-production years of the LOM continues, with the   mine operating at a rate of 2,700 t/d since commercial production began in   July 2017. The ramp-up period to a maximum output of 3,800 t/d is complete,   with production averaging 1.3 Mt annually. Geotechnical designs and   recommendations are based on the results of site investigations and   geotechnical assessments, which include rock mass characterization,   structural geology interpretations, excavation and pillar stability analyses,   and ground support design. No new rock mechanics site investigations or   analysis work was completed for this Technical Report update. 1-7 Reserves Reserves   Ore Tonnes (Mt) Grade Au (g/t) Contained Metal Au (Moz) 2020 Mineral Reserves   + Milled Actuals Proven + Probable 15.7 8.4 4.2 2019 Milled Actuals 1.3 8.7   0.4 Total 17.0 8.4 4.6 2019 Mineral Reserves Total 16.0 12.6 6.4 2020 - 2019   Difference 1.0 -4.1 -1.8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The groundwater flow system   was conceptualized to provide inflow estimates to mine workings. Total inflows   were estimated to be approximately 100 L/s, including service water. This   estimate referenced results of site investigations and hydrogeologic testing   that was used to determine the capacity of dewatering equipment, which allows   for maximum inflows of 139 L/s to account for uncertainty in the water inflow   model. The mining contractor supplies the majority of the heavy equipment   with the exception of supplemental long-hole drills for production and   sampling, and some auxiliary vehicles. Key equipment required includes a   fleet of load-haul-dump (LHD) vehicles and trucks for material loading and   transport to surface. In addition, bolters, shotcrete sprayers, long-hole   drills, and cable bolters are all required. Mining is largely conducted   through a mine contractor, with Pretivm providing planning and technical   services. The underground mining department consists of technical staff,   mining crews, mechanics, electricians, and logistical or other support   personnel. Total underground manpower, including technical support is   approximately 398, with approximately 200 on site at any time. Ventilation   has been designed to comply with BC regulations. Permanent fans at surface   are located at each of the main portals and exhaust to surface is via   dedicated raises. An electric air heating system operates to ensure all air   entering the mine is above freezing point with a propane backup. Paste fill   is distributed using a two-stage pumping system. A positive displacement pump   in the paste fill plant located in the mill provides paste to all of the West   Zone and the lower portion of the Valley of the Kings Zone (below 1,350 m).   The paste fill plant feeds a booster pump located near the main Valley of the   Kings decline. This booster pump supplies paste to the Upper Valley of the   Kings Zone (above 1,350 m). Ore is trucked from working areas to the   centrally located underground crusher and subsequently transferred to surface   via the two conveyors. Waste rock is utilized for backfill wherever possible   or trucked to surface for disposal in Brucejack Lake. The location and method   of the mine dewatering system have been changed since the 2014 FS (Ireland et   al. 2014). Mine dewatering locations are included in the long-term mine   plans, with adjustments to locations based on underground observations. No   settling of sediments or slimes is conducted underground with sediments and   slimes pumped directly to the mill clarifier by a system of submersible and   horizontal centrifugal pumps located throughout the Valley of the Kings Zone   and West Zone working levels. For underground worker safety, both permanent   and portable refuge stations have been installed at Brucejack Gold Mine. A   permanent, 40-person station has been established at the 1,335 m elevation,   another 60-person permanent refuge station will be established at the 1,200 m   elevation, with an additional six, 16-person portable rescue chambers located   elsewhere throughout the mine. Emergency warning systems include phones, cap   lamp warning systems, and stench gas warning systems. 1.7 Mineral Processing   and Metallurgical Testing Extensive metallurgical testing programs have been   conducted on the Brucejack Property since 1988, with major metallurgical test   work performed between 2009 and 2014 to support the design and construction   of the 2,700 t/d process plant at the Brucejack Gold Mine. Tetra Tech   completed a test work review and process design descriptions for the 2014 FS   (Ireland et al. 2014). Since commercial operations began in Q4 2017,   additional test work and process simulations have been completed to support   the current operation, including supports for the process plant throughput   increase to a target capacity of 3,800 t/d. 1-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE 1.7.1 Early Metallurgical Test Work and Pilot   Plant Operation The previous test work was conducted to investigate   mineralization amenability to gravity concentration, gold-silver bulk   flotation, and cyanidation processes. Sample characteristics, including   chemical composition, mineralogy, and hardness, as well as other processing   tests, including melting and solid liquid separation (SLS) tests, were also   carried out. The tested samples were obtained from the Valley of the Kings   Zone, the West Zone, and adjacent gold deposits such as the Galena Hill Zone,   the Gossan Hill (R-8) Zone, and others. The test results indicate that most   of the individual samples responded well to gravity separation, which   consisted of a centrifugal separation and panning concentration. The test   results also showed that the tested samples responded well to bulk flotation   and cleaner flotation. With further verification tests on variability samples   and locked-cycle tests on composite samples from the Valley of the Kings Zone   and the West Zone, a conventional process using combined gravity concertation   and flotation on gravity tailings was recommended for the Brucejack Gold   Mine. To confirm the recommended process design, between September 2013 and   February 2014, Strategic Minerals LLC (Strategic Minerals) processed two   batches of bulk mineral samples generated from the Valley of the Kings Zone   at the Contact Mill facility located in Philipsburg, Montana. Samples   totalling 11,500 t were processed. A combined process of gravity separation   and rougher/scavenger flotation with rougher concentrate cleaner flotation   was employed to treat the bulk material. The gravity circuit included a   Knelson concentrator and a Gemini table, while a jigging and tabling circuit   to recover coarse free gold was also added when high-grade material was fed   to the mill. No regrind circuit was applied to the rougher/scavenger   concentrates. The test results confirmed that the combined gravity and   flotation method can effectively recover gold and silver from the materials   with widely varied head grades. 1.7.2 Recent Metallurgical Test Work   Beginning in 2017, a series of test work was conducted to support the   Brucejack Gold Mine process plant optimization and throughput increase. The test   work covered mineralogy analysis, grindability, gravity separation, intensive   leaching, and flotation concentration. SLS tests and tailings paste backfill   related tests were also performed. The results were used to optimize the   current process plant operation and to assess the performance of the relevant   circuits in the proposed 3,800 t/d throughput scenario. The metallurgical   tests confirmed that significant amounts of gold and silver are gravity   recoverable, which varies with the mineralization and gold head grades.   Several simulations were conducted to evaluate primary grinding, gravity,   flotation, and concentrate and tailings thickening processes for the 3,800   t/d plant capacity expansion. Results indicate that the primary grinding   circuit is capable of reaching the target throughput capacity of 3,800 t/d.   With further optimization of the grinding operation parameters, the grinding   efficiency is anticipated to be improved. The existing cyclones and slurry   handling systems could readily accommodate the increased throughput through   minor modifications. The primary gravity circuit may reach its recommended   capacity at the increased throughput, which may slightly affect the recovery   of the gravity recoverable gold and silver. For the current flotation circuit,   the rougher and scavenger existing cells should be able to provide sufficient   flotation retention time to handle the 3,800 t/d throughput. However, the   capacity of the second and third cleaner flotation cells will require some   upgrades to accommodate the increased throughput. 1-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.7.3 Current Operation The   process flowsheet used for the current mine operation is a combination of   conventional gravity concentration and bulk sulphide flotation to recover   gold and silver into gold doré and gold-silver bearing flotation   concentrates. Ore was first introduced to the mill in May 2017 with a focus   on ramping up to the designed production throughput using ore from low-grade   ore stockpiles. On July 1, 2017, Pretivm declared commercial production at   the Brucejack Gold Mine. Table 1-6 summarizes the 2019 production data based   on Pretivm’s annual reports and news releases. Table 1-6: Brucejack Mill 2019   Production Data Note: Yearly average primary grind size is 80% passing   approximately 115 μm; monthly averages range from 80% passing approximately   98 μm to 126 μm. 1.8 Recovery Methods The Brucejack Property mineralization   typically consists of quartz-carbonate-adularia, gold-silver bearing veins,   stockwork and breccia zones, along with broad zones of disseminated   mineralization. There is a significant portion of gold and silver present in   the form of nugget or metallic gold and silver. The concentrator was designed   to process gold and silver ore at a nominal rate of 2,700 t/d to produce gold   doré and gold flotation concentrate. The mill was commissioned between March   and May of 2017 and reached full operation in Q4 2017. In 2018, various   review and assessment work was conducted to evaluate the potential of   increasing mill throughput to 3,800 t/d and identify potential bottlenecks   that may limit a further increase in the mill feed rate. The review work   indicated that with minor modifications, such as increasing some of the   slurry pump sizing and increasing the second and third cleaner flotation   capacities, the process plant can handle the increased throughput of 3,800   t/d. Currently, most of the mill upgrading has been completed, while the   installation of the third cleaner flotation cell and the new flocculant   system are in progress. As reported, the mill was operated at 4,065 t/d   average in Q4 2019. Figure 1-1 shows the processing flowsheet, including the   following components: One-stage primary crushing located underground  A 2,500 t semi-autogenous grinding (SAG)   mill feed surge bin on surface  A SAG   mill/ball mill/pebble crushing (SABC) primary grinding circuit equipped with   a gravity concentration circuit    Rougher flotation and scavenger flotation of hydrocyclone   overflow  Three stages of cleaner   flotation on combined rougher and scavenger concentrates  1-10 Time Mill Feed Tonnage Mill Feed Grade   Total Recovery Flotation Concentrate Grade Tonne t/d (g/t Au) (g/t Ag) (% Au)   (%Ag) (g/t Au) (g/t Ag) Q1 2019 295,122 3,279 8.7 13.3 96.8 85.6 48.6 131 Q2   2019 324,171 3,562 8.9 15.6 96.9 83.8 51.6 153 Q3 2019 309,754 3,367 9.1 14.7   97.0 85.5 47.2 144 Q4 2019 373,954 4,065 8.3 14.1 96.8 85.6 43.2 142 Total   2019 1,303,001 3,570 8.7 14.5 96.9 85.1 47.5 143 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Flotation concentrate   dewatering  Flotation tailings   dewatering circuits.  The mill feed ore   is crushed and ground to the particle size of 80% passing approximately 100   μm. Two gravity centrifugal concentrators, together with two upgrading tables   and one associated gravity centrifugal concentrator, recover the free nugget   gold grains from the ball mill discharge. The resulting gravity concentrate   is further refined in the gold room on site to produce gold-silver doré. The   gold and gold bearing minerals of the hydrocyclone overflow from the primary   grinding circuit are floated using rougher and scavenger flotation. The   resulting rougher flotation and scavenger flotation concentrates are upgraded   through three stages of cleaner flotation. The first cleaner scavenger   flotation tailings report to the rougher scavenger flotation to further   recover the residual gold, silver, and their bearing minerals. The third   cleaner concentrate that is the final flotation concentrate, is dewatered   using a high-rate thickener and a tower filter press prior to being loaded in   customized bulk containers for shipping. The final rougher scavenger   flotation tailings are dewatered in a deep cone thickener. Approximately 40   to 50% of the flotation tailings are used to make paste to backfill excavated   stopes in the underground mine, and the balance is pumped to Brucejack Lake   where the tailings are stored under water. The concentrate and tailings   thickener overflows are recycled as process make-up water. The underground   and collected water from the mine site are treated in the water treatment   plant in the mill. The treated water is used for mill cooling, gland seal   service, reagent preparation, and make-up water. The upgraded process plant   will continue to operate as two 12-hour shifts per day and 365 days per year.   The overall availability for the underground primary crusher circuit is 60%.   The grinding, flotation, and gravity concentration availability is 92%. The   gold room operates during the day shift only. Based on the LOM annual   average, approximately 6,261 kg of gold and 4,618 kg of silver contained in   doré and 3,420 kg of gold and 60,211 kg of silver contained in 67,900 t of   gold-silver bearing flotation concentrate will be produced each year. On   average, the flotation concentrate is expected to contain approximately 50   g/t Au and 877 g/t Ag. The arsenic content of the flotation concentrate is   expected to be marginally higher than the penalty thresholds set up by most   smelters. 1-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 1-1: Simplified   Process Flowsheet I LSM LIING J Source: Tetra Tech (2019) I'1\;ITETRA TECH   1-12 ROM ORE PRIMRY GRAVITY o EIHRA.TION ROLJGHFFLOT ATIONSCVE NGER }IThr   PJffll, THICKE NER SHAKING TABLES FILTER P ESS FURNACEDORE ..1l :;,   GOLD/SILI'Efi CONCE NTRTE i· OUCHER SCAVEo R1 sl CLEANE" 1 sl CLEANER   FLOTATICNF _OTATION - 2nc CLEANER3rrl r.l F ANF fi FLC TA TION U..ll.,,;   :Kfll..l.. PA'::ilE 1-'LAI\1 (U \ DERCPCXhD ) CJCEJACK L'KE l---+1'!i,   CONCENTRATE j t_ r - --, 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.9 Project Infrastructure   During mine construction between 2015 and 2017, a number of on-site and   off-site infrastructure components were built to support the operation. The   locations of facilities and infrastructure items were selected to take   advantage of local topography, accommodate environmental considerations,   avoid avalanche hazards, and ensure efficient and convenient underground crew   shift changes. Figure 1-2 shows the on-site infrastructure layout and Figure   1-3 illustrates the off-site infrastructure layout. Facilities and   infrastructure at or near the Brucejack Gold Mine site are currently in   operation and include the following: 73.5 km access road at Highway 37,   travelling westward to Brucejack Lake with the 12 km section of road, from km   59 to km 71 traversing the main arm of the Knipple Glacier  Site roads and pads  138 kV power supply line from the Long Lake   Hydro Substation to the substation at the Knipple Transfer Station, where the   voltage reduces from 138 to 69 kV; the transmission line carries on to the   Brucejack Gold Mine site  Site power   distribution systems from the main substations to all the facilities  Mill building containing process equipment,   process control, and instrumentation; a gravity concentration laboratory is   under planning for mine and mill feed grade control, a paste backfill plant,   and a metallurgical laboratory  Water   management infrastructure, including diversion ditches for both contact and   non-contact water, interceptor ditches, and a contact water drainage   collection pond and pump(s) to direct contact water to the water treatment   plant  Water treatment infrastructure   to treat underground infill water and surface contact water via a treatment   plant that discharges the treated water to process and fresh/fire water   tanks  Potable water treatment   facility  Sewage treatment   infrastructure  Solid waste management   systems, including domestic waste disposal and incinerator  Communication systems  Ancillary facilities including:  on-site fuel storage - on-site   explosive storage - detonator magazine storage - camp   accommodation with recreation area, commissary, laundry facilities, mine dry,   and medical clinic and first aid/emergency response - truck shop   - 1-13 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE helipad - laydown areas   - covered storage building. - The Brucejack Access Road is an   all-season, two-way access road that commences at Highway 37 at km 215 and   travels generally westward to Brucejack Lake, a distance of 73.5 km. The   access road is maintained throughout the year by road grooming equipment and   snow plows. Regular patrols are conducted, particularly, in potential   avalanche areas with avalanche control measures in place. The 12 km section   of the access road (km 59 to km 71) traverses the main arm of the Knipple   Glacier. During winter months the route is a groomed snow surface, but is an   ice surface during the summer months. The Knipple Transfer Station is located   approximately 12 km southeast of Brucejack Gold Mine site. The Knipple   Transfer Station facilities include a camp, maintenance and emergency vehicle   building, cold storage, fuel dispensing system, helipad, incinerator, assay   laboratory, truck scale, and laydown areas. All deliveries to and from the   mill site report to this facility for intermediate storage or transfer to a   different vehicle before delivery to the mine or off-site. Similarly, loads from   the mill site are managed in reverse order. An aerodrome with a 5,000 ft.   long by 75 ft. wide gravel airstrip and an apron for aircraft parking at   1,424 ft. elevation is located at the Bowser site, approximately 2 km east of   Knipple Lake. The aerodrome is available to provide air service by chartered   flights to and from the mine. Expansion of the runway to 100 ft. width and   5,500 ft. length with lighting and apron up-grades is under study to allow   AGN IIIA class aircraft, such as the DE Havilland Dash 8 turboprops, to use   the aerodrome. Currently, personnel transportation between Brucejack Gold   Mine and Smithers/Terrace, BC is facilitated by chartered bus service.   However, routine crew changes by chartered air service is under study. There   is a security gatehouse and camp at the Wildfire Camp site, located on the   Brucejack Access Road near the intersection of Highway 37. The security   gatehouse provides access control to the inbound and outgoing traffic along   the Brucejack Access Road. 1-14 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 1-2: Brucejack Gold   Mine On-site Infrastructure Layout Infrastructure Source: Pretivm (2019)   I'1\;I 1-15 TETRA TECH R n1r.,.,jnr.\: ;::...,!rt Mn   ---o,<:o-t."'""'"" "'O'I   --·-i.FI<"')N I't\C Quon")' "'.II U.!loc<   )vTlIJtlna";> Cr.rt I\G--1 --r., g;th•_,,..,.--Co-.t>ct/' <J•   Li>o>--•.....--P.IilPii:flll<ntL"""C]Toe o. :-w n'   ecgr) ........ ,,. --•·c•·•·   >---<c·I:J•·"""""''"" C<p - I,   Z(IViu:.: 1o,lC\.n>............ ri< <.,! .........,.. Lir><   :;,.,.,!O:,t\oy 125 PRETIVM Ill PReTIUM RCSOJRC[S I"C . J.00-'10 ::;   o-......... ''"'"' Y<:•cw-er,fltflX 1L4 (;OfiOd<l (}5 7e-t   Brur.:ej:u:k On-Site I "' 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 1-3: Brucejack Gold   Mine Off-site Infrastructure Layout • CUIINIIIIIU-"Il»itTuwus -   Hig"l1o1J:IIy'37 f 3i'A 5 5 Source: Pretivm (2019) ['n;ITETRA TECH 1-16   4!0000 • Aorodr6mo Bocon; -&ucejac.< Tra n5nission line LOOScJncnl II   I.JeteoroiOQic.al Slaton ··-·-· Gtitl'tdu:; R:(.lad 1:XXl, UlM z.mo 9 (NAC   OJ) LetnQLa K e Tral"6ni sion ireio-llllrl"li: ==:ii.o--'   "'12COOO··= : 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The tailings delivery system   discharges thickened tailings slurry to the bottom of Brucejack Lake   (approximately 80 m deep) when not used for paste backfill (approximately 40   to 50% of the time). For discharge to the lake, the tailings slurry is pumped   to an agitated slurry mixing tank and then diluted at the nominal solids   throughput rate of approximately 180 t/h. The diluted slurry is pumped overland   and then underwater along the suspended discharge lines to the discharge   point. Both the pipes are suspended on cables to allow for vertical and   horizontal repositioning over the LOM to ensure the pipe is not covered by   tailings and to meet permit conditions for vertical positioning above the   lake bottom. A 138 kV overhead power supply line from the substation at Long   Lake Hydro Substation was constructed in 2016/2017 and connects to the   Knipple Substation. The main site power steps down from 138 to 69 kV via two   20/26 MVA oil-filled transformers, complete with neutral grounding resistors,   located in the main substation yard at the Knipple Substation. Each   transformer is capable of carrying the entire site load. The 69 kV   transmission line is transported to Brucejack Gold Mine where it enters into   the mill. The voltage is further stepped down from 69 kV to 4.16 kV via 2 x   15/20/25 MVA oil-filled transformers and distributed to the site via 4.16 kV   rated switchgear. The rating for site on a distribution end is 4.16 kV and   further transformed to 0.6 kV for smaller loads. The main mill and   underground loads are fed via power cables in cable tray. The main substation   is located inside the mill. Power feeds to the mill building, camps, truck   shop, and underground are all underground buried services. Within the mill,   large loads are powered at 4.16 kV. Smaller loads are powered at 600 V via   switchgear and motor control centers (MCCs). Variable frequency drives (VFDs)   and soft starters are employed strategically to optimize process and energy   performance. An avalanche hazard assessment of the mine site, access road,   and transmission line route was presented in the 2014 FS (Ireland et al.   2014). Generally, the avalanche hazard assessment of the mine site, access road,   and transmission line route remains unchanged from the 2014 FS (Ireland et   al. 2014). The avalanche season for infrastructure below the 1,000 m   elevation level is generally from November to May, while for elevations above   1,200 m the season is from October to June, or if cool and wet conditions   persist, avalanches can occur in summer months. Snow avalanches generally   occur in areas where there are steep open slopes or gullies, and deep (more   than 50 cm) mountain snow packs. Risks associated with avalanches are   normally due to exposure to the high impact forces that occur, as well as the   effects of extended burial for any person caught in an avalanche. An   avalanche path generally consists of a starting zone, a track, and a runout   zone. Pretivm has full time mountain safety technicians who monitor avalanche   risk, develop hazard ratings for the Brucejack Access Road for specific   sections, and release hazard bulletins with avalanche ratings for those road   sections and glacier hazard ratings for travel on the glacier. Mountain   safety technicians regularly survey the ice road and work with road   maintenance to ensure safe travel on the ice. 1-17 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.10 Environmental Studies,   Permitting and Social and Community Impact Pretivm is committed to continuing   to operate the Brucejack Gold Mine in a sustainable manner and according to   the guiding principles in its corporate Social, Environmental, and Health and   Safety policies. Pretivm regularly consults with public, Indigenous groups,   and stakeholders on the Brucejack Mine and commitments for engagement,   communication, and local recruitment. Every reasonable effort has and will continue   to be made to minimize or prevent potential long-term adverse environmental   effects and to ensure that the mine provides lasting benefits to local   Indigenous and other communities while generating substantial economic and   social value for shareholders, employees, and the broader community. Pretivm   developed an Economic and Social Effects Mitigation Plan (ESEMP) as a   requirement of its provincial Environmental Assessment Certificate and   reports annually on the outcomes and achievements related to the ESEMP.   Pretivm respects the traditional knowledge of the Indigenous peoples who have   historically occupied or used the Project area and is committed to an   engagement process that continues to invite and consider input from people   with traditional knowledge in the area. Pretivm’s objectives include   continuing to retain the integrity of ecosystems within which mine   infrastructure is located to the extent feasible during the remainder of mine   operations. Upon mine closure, the intent will be to reclaim mine infrastructure   disturbance areas to the approved end land uses in accordance with the   approved reclamation plan, thereby returning the disturbed areas to levels of   land productivity equal to or better than existed prior to mine development.   Pretivm maintains a reclamation security of $31.7 million with the BC   government for the full build-out of the mine. 1.11 Capital and Operating   Cost Estimates 1.11.1 Capital Cost Estimate The total LOM sustaining capital   cost from 2020 to 2032 is estimated at US$176.7 million. Table 1-7 shows a   summary breakdown of the LOM sustaining capital costs by area, including   required sustaining costs for the mine and mill throughput expansion to 3,800   t/d. The estimated cost includes design, construction, installation, and   commissioning. The key inputs to this cost estimate were based on the LOM   planned costs estimated by Pretivm and reviewed by Tetra Tech, including   recent equipment purchased costs, equipment quotations from vendors, and   recent construction cost data. All costs are inclusive of direct cost,   indirect cost, and contingency. The expected accuracy range of the operating   cost estimate is +20%/-15%. Table 1-7: LOM Sustaining Capital Cost Estimates   1-18 Area Description LOM Sustaining Capital Cost (US$ million) Mining 66.6 Processing   3.5 Site Infrastructure and Services 91.8 Mine Throughput Expansion 14.8   Total 176.7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.11.2 Operating Cost   Estimate The estimated LOM average operating cost for the Brucejack Gold Mine   is US$162.82/t milled. Table 1-8 shows the cost breakdown for each area and   Figure 1-4 shows the cost distribution by area. Table 1-8: LOM Average   Operating Cost Summary Notes: (1)Including the costs for off-site and   satellite offices. G&A – general and administrative. Figure 1-4: Overall   Operating Cost Distribution by Area The operating cost estimate is based on   the Brucejack Gold Mine operating experience, including consumable supplies,   power supply, contractor services, camp services, personnel transportation,   and labour salaries/wages with a base date of Q4 2019 and do not include any   escalation beyond this quarter. The expected accuracy range of the operating   cost estimates is -15%/+15%. All the costs have been estimated in US dollars,   unless otherwise specified. 1-19 Area Unit Operating Cost (US$/t milled)   Mining 70.83 Processing 21.34 Overall Site Services, including Office(1)   35.89 G&A 34.76 Total Operating Cost 162.82 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The operating costs exclude   shipping charges and sale costs for the gold-silver doré and gold-silver   concentrate and royalties, which are included in the financial analysis. All   operating cost estimates exclude taxes unless otherwise specified. 1.12   Economic Analysis Tetra Tech prepared an economic evaluation of the Brucejack   Gold Mine based on a discounted cash flow model for the remaining 13-year LOM   and 15.64 Mt of ore included in the mine plan. For this mine plan, a post-tax   net present value (NPV) of US$1.50 billion was calculated at a discount rate   of 5%. The Brucejack Gold Mine economic model is based on the following   assumptions: Gold price of US$1,300/oz    Silver price of US$16.90/oz    Foreign exchange rate of Cdn$1.00:US$0.76.  The production schedule was incorporated   into the pre-tax financial model to develop annual recovered metal   production. Capital expenditures include 3,800 t/d mine expansion capital   cost of US$14.8 million and ongoing sustaining capital costs for mining and   milling additions and equipment replacement totaling US$161.9 million. The   total LOM capital cost is US$176.7 million. The NPV was estimated at the   beginning of the mining schedule and therefore has an effective date of   January 1, 2020. Table 1-9 summarizes the forecast for the economic   performance of the Brucejack Gold Mine operation for the remaining LOM. Table   1-9: Brucejack Gold Mine Economic Performance Forecast 1-20 Unit Amount   Tonnes Mined and Processed kt 15,637 Gold Head Grade g/t 8.4 Silver Head   Grade g/t 59.6 Total Project Revenue US$ million 5,266 Operating Costs US$ million (2,546) Royalties US$ million (63) Sustaining Capital Costs,   including Mine Expansion US$ million (177) Other Expenses US$ million (21)   Taxes Payable US$ million (492) Post-tax NPV (5% Discount Rate) US$ million   1,496 Post-tax NPV (8% Discount Rate) US$ million 1,293 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1.13 Project and Operation   Risks There are no known environmental liabilities or other significant risks   or factors that may affect access, title, or the ability or right to operate   the mine or perform work on the Brucejack Property, beyond the geopolitical,   economic, permitting, and legal climate that Pretivm operates in and   Pretivm’s ability to secure any required approvals, consents, and permits   under applicable legislation. 1.14 Conclusions and Recommendations The   Brucejack Gold Mine is considered to be economically viable based on the   results of the work presented in this Technical Report. The mine has a   demonstrated capability of processing 3,800 t/d of ore or higher. Section   26.0 outlines detailed recommendations for the Brucejack Gold Mine. 1-21 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The Brucejack Gold Mine,   located in northwest BC, is a high-grade underground mining operation that   commenced commercial production in July 2017. Brucejack uses conventional   gravity concentration and sulphide flotation to produce gold-silver doré and   gold-silver flotation concentrate. Pretivm, a low-cost intermediate gold   producer, owns 100% of the Brucejack Property. In January 2020, Pretivm   commissioned Tetra Tech to complete an update to the 2019 NI 43-101 Technical   Report. This NI 43-101 Technical Report, effective on March 9, 2020, updates   Mineral Resource and Mineral Reserve, the LOM plan and operating parameters.   The effective date of the 2020 Mineral Reserve and 2020 Mineral Resource is   January 1, 2020. The following consultants were commissioned to complete work   and reviews for the purpose of the Technical Report: Tetra Tech – mineral   processing and metallurgical testing, mineral reserve estimates, mining   methods, recovery methods, project surface and underground infrastructure,   market studies and contracts, capital and operating cost estimates, and   economic analysis.  Ivor Jones Pty Ltd   – property description and location; accessibility, climate, and physiology;   history; geological setting and mineralization; deposit types; exploration;   drilling; sample preparation and analysis; data verification; adjacent   properties; and mineral resource estimates.    ERM – aspects of environmental studies, permits, and social or   community impacts; waste management; and closure plans.  Lorax – hydrogeology, geochemistry, water   balance, and water quality.  SRK –   waste rock and tailings storage facility, underground and surface   geotechnical design, and water management.    2.1 Terms of Reference The following terms of reference are included   throughout this report: The Brucejack Property refers to the mineral claims   that were acquired as the property, as listed in Table 4-1.  The Brucejack Gold Mine refers to the   property only on the mining leases, as listed in Table 4-1.  The Brucejack Project refers to all   geological or engineering work completed on and around the Brucejack Gold   Mine that leads to the short-term advancement of the existing mining   operation. It includes near-mine exploration and all of the off-mining leases   infrastructure.  The April 2012 Mineral   Resource for the West Zone is detailed in Jones (2012a). There has been no   change to the April 2012 West Zone Mineral Resource since that time. All   references to the Mineral Resource for the Brucejack Deposit from November   2012 to present incorporate the April 2012 West Zone Mineral Resource.  The November 2012 Mineral Resource for the   Valley of the Kings Zone is detailed in Jones (2012c).  The December 2013 Mineral Resource for the   Valley of the Kings Zone is detailed in Jones (2014).  2-1 2.0INTRODUCTION 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The December 2016 Mineral   Resource for the Valley of the Kings Zone is detailed in Pretivm (2016) and   Board et al. (2017).  The January 2019   Mineral Resource is detailed in the 2019 Technical Report on the Brucejack   Gold Mine, Northwest British Columbia, by Jones, et al (2019).  The January 2020 Mineral Resource is   detailed in the current Technical Report.    2.2 Site Visits In accordance with NI 43-101 guidelines, the following   QPs completed a visit to the Brucejack Property: 1. Hassan Ghaffari, P.Eng.,   M.A.Sc. of Tetra Tech visited the Brucejack Property on March 13, 2019. 2.   Maureen Phifer, P.Eng., B.Sc. of Tetra Tech visited the Brucejack Property   from January 20 to 22, 2020. 3. Jianhui (John) Huang, Ph.D., P.Eng. of Tetra   Tech visited the Brucejack Property on March 6 and 7, 2018 and on June 5 and   6, 2018. 4. Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM, CP(Geo) of Ivor Jones   Pty Ltd has visited the Brucejack Property several times since 2012, with the   most recent visits from August 20 to 24, 2018 and April 18, 2020. 5. Rolf   Schmitt, M.Sc., P.Geo. of ERM visited the Brucejack Property from April 1 to   3, 2019. 6. Alison Shaw, Ph.D., P.Geo. of Lorax visited the Brucejack   Property from June 3 to 6, 2019. 7. Timothy Coleman, P.Eng. of SRK visited   the Brucejack Property on September 24, 2019. 8. Mauricio Herrera, P.Eng.,   Ph.D. of SRK visited the Brucejack Property from August 19 to 21, 2019. 9.   Calvin Boese, P.Eng., M.Sc. of SRK visited the Brucejack Property from August   19 to 21, 2019. 10. Laura-Lee Findlater, B.Sc. P.Geo., of Lorax visited the   Brucejack Property on October 7 and 9, 2019. 11. Colin Fraser, P.Geo., M.Sc.   of Lorax visited the Brucejack Property from August 19 to 22, 2019. 2.3   Qualified Persons The QPs responsible for this technical report are listed in   Table 2-1. 2-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 2-1: Summary of QPs   table continues... 2-3 Report Section Company QP 1.0Summary All Sign-off by   Subsection 2.0Introduction Tetra Tech Jianhui (John) Huang, Ph.D., P.Eng.   3.0Reliance on Other Experts Tetra Tech Sign-off by Subsection 4.0Property   Description and Location Ivor Jones Pty Ltd Ivor W.O. Jones, M.Sc., P.Geo.,   FAusIMM 5.0Accessibility, Climate, Local Resources, Infrastructure, and   Physiography Ivor Jones Pty Ltd Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM   6.0History Ivor Jones Pty Ltd Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM   7.0Geological Setting and Mineralization Ivor Jones Pty Ltd Ivor W.O. Jones,   M.Sc., P.Geo., FAusIMM 8.0Deposit Types Ivor Jones Pty Ltd Ivor W.O. Jones,   M.Sc., P.Geo., FAusIMM 9.0Exploration Ivor Jones Pty Ltd Ivor W.O. Jones,   M.Sc., P.Geo., FAusIMM 10.0Drilling Ivor Jones Pty Ltd Ivor W.O. Jones,   M.Sc., P.Geo., FAusIMM 11.0Sample Preparation, Analyses and Security Ivor   Jones Pty Ltd Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM 12.0Data Verification   Ivor Jones Pty Ltd Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM 13.0Mineral   Processing and Metallurgical Testing Tetra Tech Jianhui (John) Huang, Ph.D.,   P.Eng. 14.0Mineral Resource Estimates Ivor Jones Pty Ltd Ivor W.O. Jones,   M.Sc., P.Geo., FAusIMM 15.0Mineral Reserve Estimates Tetra Tech Maureen   Phifer, P.Eng., B.Sc. 16.0Mining Methods Tetra Tech/ SRK Maureen Phifer,   P.Eng., B.Sc./ Timothy Coleman, P.Eng, 17.0Recovery Methods Tetra Tech   Jianhui (John) Huang, Ph.D., P.Eng. 18.0Project Infrastructure Tetra Tech/   SRK Hassan Ghaffari, P.Eng., M.A.Sc./ Mauricio Herrera, P.Eng., Ph.D./ Calvin   Boese, P.Eng., M.Sc. 19.0Market Studies and Contracts Tetra Tech Jianhui   (John) Huang, Ph.D., P.Eng. 20.0Environmental Studies, Permitting, and Social   or Community Impact ERM/ SRK/ Lorax Rolf Schmitt, M.Sc., P.Geo./ Mauricio   Herrera, P.Eng., Ph.D./ Colin Fraser, P.Geo., M.Sc./ Alison Shaw, Ph.D.,   P.Geo./ Laura-Lee Findlater, B.Sc., P.Geo. 21.0Capital and Operating Costs   Tetra Tech Jianhui (John) Huang, Ph.D., P.Eng./ Maureen Phifer, P.Eng.,   B.Sc./ Hassan Ghaffari, P.Eng., M.A.Sc./ 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 2.4 Information and Data   Sources A complete list of references is provided in Section 27.0. 2-4 Report   Section Company QP 22.0Economic Analysis Tetra Tech Maureen Phifer, P.Eng.,   B.Sc. 23.0Adjacent Properties Ivor Jones Pty Ltd Ivor W.O. Jones, M.Sc.,   P.Geo., FAusIMM 24.0Other Relevant Data and Information Tetra Tech Jianhui   (John) Huang, Ph.D., P.Eng. 25.0Interpretation and Conclusions All Sign-off   by Subsection 26.0Recommendations All Sign-off by Subsection 27.0References   All Sign-off by Subsection 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 3.1 Introduction The QPs who   prepared this Technical Report relied on information provided by experts who   are not QPs. The relevant QPs believe that it is reasonable to rely on these   experts, based on the assumption that the experts have the necessary   education, professional designations, and relevant experience on matters   relevant to the Technical Report. 3.2 Status of Mining Leases and Mineral   Claims Ivor Jones, P.Geo., FAusIMM relied upon public information, as well as   information from Max Holtby, P.Geo., Director of Permitting for Pretivm,   regarding the status and circumstances of the Brucejack Property mining   leases and mineral claims as reported in Section 4.0. 3.3 Environment, Social   and Sustainability Rolf Schmitt, P.Geo. relied upon public information posted   on the websites of government regulators as well as information from Greg   Norton, V.P. of Environment and Regulatory Affairs for Pretivm regarding   components of the Brucejack Mine Environmental Management System described in   Section 20.1.1.2, and mine wastes generated to date and forecast to be   generated over the LOM as described in Section 20.3.6.1. 3.4 Marketing   Studies John Huang, P.Eng. relied on Janice Song, CPA, CGA, MBA, Director,   Treasury from Pretivm, for guidance on marketing studies, including   gold-silver doré and gold-silver concentrate smelting terms and products   transportation as described in Section 19.0. 3.5 Economic Analysis Maurie   Phifer, P.Eng. relied on Velibor Petric, Site Mine Controller from Pretivm,   for guidance on applicable taxes and royalties relevant to revenue or income   from the Brucejack Gold Mine as detailed in Section 22.0. 3-1 3.0RELIANCE ON   OTHER EXPERTS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Information in this section   has been excerpted from Jones (2014) and updated. 4.1 Location The Brucejack   Property is centered approximately at 56°28'20"N Latitude by   130°11'31"W Longitude (Universal Transverse Mercator (UTM) 426,967E   6,258,719N North American Datum (NAD) 83 Zone 9), a position approximately 950   km northwest of Vancouver, 65 km north-northwest of Stewart, and 21 km   south-southeast of the Eskay Creek Mine (Figure 4-1). The Brucejack Property   coordinates used in this Technical Report are located relative to the NAD83   UTM coordinate system. Figure 4-1: Brucejack Property Location Map Source:   Pretivm 4-1 4.0PROPERTY DESCRIPTION AND LOCATION 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 4.2 Tenure In 2010, pursuant   to a purchase and sale agreement between Silver Standard (as the seller) and   Pretivm (as the buyer), Silver Standard sold to Pretivm all of the issued   shares of 0890693 BC Ltd., the owner of the Brucejack Gold Mine and the   Snowfield Project. Subsequently, the name of 0890693 BC Ltd. changed to   Pretivm Exploration Inc. 4.3 Status of Mining Titles The Brucejack Property   is located on provincial Crown land and consists of four mining leases and   six mineral claims that cover the target Mineral Resource, totaling 3,305.85   ha in area. According to the BC Mineral Titles Office official information,   all mining leases are in good standing until September 17, 2020; all mineral   claims are in good standing until January 31, 2031 (Table 4-1). Brucejack   Property mineral claims and mining leases are contiguous with the Snowfield   and Bowser properties, a large block of mineral claims held by Pretivm   (Figure 4-2). The Snowfield and Bowser Properties form a block of mineral   claims that total 338 mineral claims and measure approximately 122078 ha   (Figure 4-3). Pretivm mineral claims extend from the Brucejack Gold Mine site   area east to Highway 37, including parts of the Bowser River, Scott Creek,   and Wildfire Creek watersheds, and along parts of the transmission line   right-of-way. The Brucejack Gold Mine is situated within the Sulphurets   District, Skeena Mining District. Table 4-1: Mineral Claims for the Brucejack   Property The QP relied upon public information, as well as information from   Pretivm, regarding the Brucejack Property claims and has not undertaken an   independent verification of title and ownership. However, the QP verified   information relating to tenure, to the extent possible, using public   information available through the Mineral Titles Branch of the BC Ministry of   Energy, Mines & Petroleum Resources (MEMPR) Mineral Titles Online (MTO)   land tenure database. A legal land survey of the mining leases was undertaken   in June 2015 and approved by the BC Surveyor General on September 3, 2015. A   legal survey of the mineral claims has not been undertaken. 4-2 Tenure No.   Tenure Type Map No. Owner Pretivm Interest (%) Status In Good Standing To   (dd-mm-yy) Area (ha) 509223 Mineral Claim 104B Pretivm Exploration Inc. 100   Good 31-Jan-31 428.62 509397 Mineral Claim 104B Pretivm Exploration Inc. 100   Good 31-Jan-31 375.15 509400 Mineral Claim 104B Pretivm Exploration Inc. 100   Good 31-Jan-31 178.63 1027399 Mineral Claim 104B Pretivm Exploration Inc. 100   Good 31-Jan-31 983.61 1027400 Mineral Claim 104B Pretivm Exploration Inc. 100   Good 31-Jan-31 500.39 1034915 Mineral Claim 104B Pretivm Exploration Inc. 100   Good 31-Jan-31 89.35 1038597 Mining Lease 104B Pretivm Exploration Inc. 100   Good 17-Sep-20 53.60 1038598 Mining Lease 104B Pretivm Exploration Inc. 100   Good 17-Sep-20 533.61 1038599 Mining Lease 104B Pretivm Exploration Inc. 100   Good 17-Sep-20 35.70 1038600 Mining Lease 104B Pretivm Exploration Inc. 100   Good 17-Sep-20 107.20 Total (ha) 3,305.85 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE The QP understands that there   are no annual holding costs for any of the six mineral claims at this time,   as the claims are paid up until January 31, 2031. Annual rental holding fees   for the four mining leases total Cdn$15, 002. Figure 4-2: Brucejack Property   Mineral Claims § N § N "N' "N' tium Resources - Other Claim Source:   Pretivm (2019) ['n;ITETRA TECH 4-3 420000 425000 430000 0.......... <D   <D 8 8 <D <D cejack Mine Site cejackAccess Road tium R   esources·Brucejack Property er Claim Boundary 420000 425000 430000   P01_BJ_2100_Mntt"'I_O•ms_85.lc11_201117 Se l abridge Gold Pretium   Resources + + + * Bru --Bru DPre c::J Pre c:J Oth U 0 TM Zone 9 (NAD83)   PRETIVM Ill C LA I M MAP BRU CEJ ACK PROJECf BRIT I SH COLUli•IBlA 24   Kilometers + + + + Inc. 509223 509397 509400 1027399 + + + 0 N 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 4-3: Pretivm Mineral   Claims D Pretit.m Resources •Brucejttek Property C LAIM MAP BR UCE J AC K   PROJECT 0 2.5 5 10 15 Source: Pretivm ( 2019) I'1\:I TETRA TECH 4-4 420000   440000 Brucejack ,£---...1 Property * Bruce;ack Mine sa -Transminion Li ne   --Bruccj:Jck AceRoad DPrctiun Rosourcos • Othor CI:Mm - Kilometers BRITISH   COLU MBIA 420000 460000 P01_BJ_2100_MMrai_CiairN_Zoom_OUt_85x11_20190117 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The majority of the Brucejack   Property lies within the boundaries of the Cassiar-Iskut-Stikine Land and Resource   Management Plan (LRMP) area, with only a minor south-eastern segment of   Mineral Claim No. 1027399 and Mining Lease No. 1038600 occurring outside this   area. All claims and leases located within the boundaries of the LRMP are   considered areas of General Management Direction, with none of the leases or   claims occurring inside any Protected or Special Management Areas. As of the   effective date of this report, the land claims in the area are in review and   subject to ongoing discussions between various First Nations and the   Government of BC. The mining operation is fully permitted. A Mines Act permit   and two Environmental Management Act permits along with a BC Environmental   Assessment Act certificate and the Decision Statement of July 27, 2015, under   Section 54 of the Canadian Environmental Assessment Act, 2012 provide the   basis for approvals of the mine and use of the site for mining purposes. Mine   infrastructure and infrastructure along the road are permitted under a   variety of permits for water use and camps with land use held under various   Licenses of Occupation and the access road held under a provincial Special   Use permit. Tailings storage and waste rock are permitted under an   Environmental Management Act discharge permit while surface and underground operations   are regulated by the Mines Act permit. There are no known environmental   liabilities or other significant risks or factors that may affect access,   title, or the ability or right to operate the mine or perform work on the   Brucejack Property, beyond the geopolitical, economic, permitting, and legal   climate that Pretivm operates in and Pretivm’s ability to secure any required   approvals, consents, and permits under applicable legislation. 4.4   Confirmation of Tenure The QP is not qualified to provide legal comment on   the mineral title to the reported properties and has relied on the provided   information. No warranty or guarantee, be it expressed or implied, is made by   the QP with respect to the completeness or accuracy of the tenement   description referred to in this document. 4.5 Royalties, Fees, and Taxes The   royalties applicable to the original Brucejack area, not including Mining   Lease No. 1038600, are as follows: “Royalty” means the amount payable by the   Owner, calculated as 1.2% of the NSR, with the following exemptions:  Gold: The first 503,386 oz produced from   the Brucejack Gold Mine. - Silver: The first 17,907,080 oz produced   from the Brucejack Gold Mine. - The QP understands that the 1.2% NSR royalty   is, at the time of this report, in favour of the Franco-Nevada Corporation.   Mining Lease No. 1038600 is subject to a 2% NSR royalty, minimum annual   payments of Cdn$50,000 with a buy out provision of Cdn$4 million per 1%,   i.e., a total of Cdn$8 million. Mining Lease No. 1038600 does not cover any   of the area within the current mine plan. 4-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Information in this section   has been excerpted and updated from Jones (2014). It does not cover the   majority of the mine infrastructure, which is covered under Section 18.0. 5.1   Climate and Physiography The climate at the Brucejack Property is typical of   northwestern BC with cool, wet summers and relatively moderate but wet winters.   Annual temperatures range from +20 to -20°C. Precipitation is high with heavy   snowfall accumulations ranging from 10 to 15 m at higher elevations and 2 to   3 m along the lower river valleys. Snowpacks cover the higher elevations from   October to June. The optimum field season for surface works is from late June   to mid-October. Mine infrastructure is located at 1,360 to 1,415 masl along   Brucejack Creek and immediately southwest of Brucejack Lake. Topographic   relief is moderate to low in the immediate mine site; however, across the   Brucejack Property, the terrain is generally steep with local reliefs of   1,000 m from valleys occupied by receding glaciers, to ridges at elevations   of 1,900 masl. Elevations within the mine area range from 1,360 masl along Brucejack   Lake to 1,500 masl at the Valley of the Kings meteorological station. 5.2   Vegetation The Brucejack Gold Mine site is devoid of trees with only sparse   mosses along drainages; the tree line is at an elevation of approximately   1,200 m. On the Brucejack Property, sparse fir, spruce, and alder grow along   the valley bottoms with only scrub alpine spruce, juniper, alpine grass,   moss, and heather covering the steep valley walls. Rocky glacial moraine and   polished glacial-striated outcrops dominate the terrain above the tree line.   5.3 Accessibility The Brucejack Property is located in the Boundary Range of   the Coast Mountain Physiographic Belt. Pretivm constructed a 73 km access   road that links the Brucejack Camp to Highway 37 at km 215, approximately 60   km north of Meziadin Junction. From Highway 37, the road crosses the Bell   Irving River to Wildfire Camp and then traverses Wildfire Creek valley to the   headwaters of Scott Creek, traverses along Scott Creek valley to Bowser River   valley and then proceeds along Bowser River valley to Knipple Glacier, a   distance of 58 km. A 12 km road is established along Knipple Glacier to the   headwaters of the Brucejack Creek watershed, at which point the road extends   3 km to the mine site. Provincial permits and federal authorization of the   mine prohibit public use of the access road. A gate is located at the Highway   37 junction, and security screening is undertaken at Wildfire Camp. Along the   access road, a 5,400 ft. aerodrome has been established at Bowser Aerodrome 5   km east of Knipple Camp (Lake) (Figure 5-1). Personnel, equipment, fuel, and   camp provisions are driven to a staging area at Knipple Camp, before being   taken over the glacier to the Brucejack Camp. The Brucejack Property area is   also easily accessible with the use of a chartered helicopter from the town   of Stewart, or seasonally from the settlement of Bell II. The flight time   from Stewart is approximately 30 minutes and slightly less from Bell II;   however, Stewart has the advantage of having an established year-round   helicopter base. 5-1 5.0ACCESSIBILITY, CLIMATE, LOCAL RESOURCES,   INFRASTRUCTURE AND PHYSIOGRAPHY 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The larger communities of   Smithers and Terrace, located 326 km and 300 km, respectively by road,   provide hubs for mine personnel to live and airports for out-of-the-region   staff to commute to site. Charter busses provide transport from these   communities and other communities along Highway 16 to the Brucejack Gold   Mine. Rail traffic can load and unload in Terrace, and port facilities at   Stewart and Prince Rupert are available for off-shore transport. 5-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 5-1: Project Access 0   50 100 Kilometers Kllomelels Source: Pretivm (2019) I'1t:I TETRA TECH 5-3 N L   Lake BRITISH COLUMBIA CANADA UTM Zone 9 (NI\083) 0510 20 -==:l EskayCreek 'X'   I'{s 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 5.4 Infrastructure The access   road from Highway 37 is complete and in use (Figure 5-1). All resources are   brought into the mine and remote camps via the mine site access road   connecting to highway 37. Infrastructure along the access road includes camps   at Wildfire and Knipple and Bowser Aerodrome, 5 km east of Knipple Lake. At   the mine, the camp comprises accommodation for 542 with recreational, office,   and multiple support facilities. The nearest off-site infrastructure is   located in the town of Stewart, approximately 65 km to the south, which has a   minimum of supplies and personnel. The towns of Terrace and Smithers are also   located in the same general region as the Brucejack Property, and both are   directly accessible by daily air service from Vancouver. The nearest railway   is the Canadian National Railway Yellowhead route, which is located   approximately 220 km to the southeast. This line runs east-west and   terminates at the deepwater port of Prince Rupert on the west coast of BC.   Stewart, BC, the most northerly ice-free shipping port in North America, is   accessible to store and ship concentrates. At the effective date of this   report, Brucejack Mine ships concentrate via this terminal. A BC Hydro   high-voltage, 138 kV transmission line services Stewart, BC. The Long Lake   transmission line extends north from Stewart and connects their generating   facilities with a BC Hydro high-voltage transmission line. The 57 km   Brucejack transmission line extends from the Long Lake generation station to   the mine via the Knipple Substation. Electric power is stepped down at the   Knipple Substation from 138 to 69 kV and is then delivered to Brucejack mine   site. Emergency power is available from diesel generators located at   Brucejack. Mine infrastructure and infrastructure along the road are   permitted under a variety of permits for water use and camps with land use   held under various Licenses of Occupation. Tailings storage and waste rock   are permitted under discharge permits with adequate storage capacity in   Brucejack Lake. The access road is permitted under a provincial Special Use   Permit. 5-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Information in this section   has been updated from Ireland et al. (2014). 6.1 Early Exploration The   earliest known prospecting in the Brucejack Lake area occurred in the 1880s   (McPherson 1994). In 1935, copper-molybdenum mineralization was discovered on   the Sulphurets Property by prospectors in the vicinity of the Main Copper   Zone, approximately 6 km northwest of Brucejack Lake; however, these claims   were not staked until 1960. From 1935 to 1959, the area was relatively   inactive with respect to prospecting; however, it was intermittently   evaluated by a number of different parties and resulted in the discovery of   several small copper and gold-silver occurrences in the Sulphurets-Mitchell   Creek area. In 1959, Granduc Mines Ltd. (Granduc) and Alaskan prospectors   staked the main claim group, covering the known copper and gold-silver   occurrences, which collectively became known as the Sulphurets Property. This   was the start of what could be termed the era of modern exploration (Table   6-1). Table 6-1: Exploration History of the Sulphurets Property between 1960   and 2008 table continues... 6-1 Date Exploration 1960 to 1979 Granduc continued   exploration, conducting further geological mapping, lithogeochemical   sampling, trenching, and diamond drilling on known base and precious metal   targets north and northwest of Brucejack Lake. This resulted in the discovery   of gold-silver mineralization in the Hanging Glacier area and molybdenum on   the south side of the Mitchell Zone. 1980 Esso Minerals Canada Ltd. (Esso)   optioned the Sulphurets Property from Granduc and subsequently completed an   extensive program consisting of mapping, trenching, and geochemical sampling   that resulted in the discovery of several showings including the Snowfield   Zone, Shore Zone, West Zone, Galena Hill Zone, and Electrum Zone targets.   Gold was discovered on the peninsula at Brucejack Lake near the Shore Zone.   1982 and 1983 Exploration was confined to gold-and silver-bearing vein   systems in the Brucejack Lake area at the southern end of the Sulphurets   Property from 1982 to 1983. Drilling was concentrated in 12 silver and   gold-bearing structures, including the Near Shore Zone and West Zone, located   800 m apart near Brucejack Lake. Drilling commenced on the Shore Zone. 1983   and 1984 Esso continued work on the Sulphurets Property and (in 1984)   outlined a deposit on the West Zone at Brucejack. 1985 Esso dropped the option   on the Sulphurets Property. 1985 The Sulphurets Property was optioned by   Newhawk Gold Mines Ltd. (Newhawk) and Lancana Mining Corp. (Lancana) from   Granduc under a three-way joint venture (JV) (the Newcana JV). The Newcana JV   completed work on the Snowfield Zone, Mitchell Zone, Golden Marmot Zone,   Sulphurets Gold Zone, and Main Copper Zone targets, along with lesser known   targets. 1986 to 1991 Between 1986 and 1991, the Newcana JV spent   approximately Cdn$21 million developing the West Zone and other smaller   precious metal veins, on what would later become the Bruceside Property.   Newhawk completed 35,241.6 m in 511 surface diamond drillholes, 5,276 m of   exploratory underground drifting, and 35,981 m of drilling in 442 underground   drillholes on the West Zone between 1987 and 1990. This work resulted in the   discovery of more than 40 additional showings and the outlining of a   historical and no longer current mineral reserve for the West zone of 750,000   t grading 15.4 g/t Au and 678 g/t Ag (Schroeter 1994). Newhawk acquired a 60%   interest in the Bruceside Property after buying out Lancana’s interest in   1987. 6.0HISTORY 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 6.2 Exploration by Silver   Standard Resources Inc. (2001 to 2010) Silver Standard initiated exploration   on the Brucejack Property in 2009 as a result of its successful bulk tonnage   drilling on the Snowfield Property (Narciso et al. 2010). Silver Standard designed   the 2009 Brucejack drill program test for additional bulk tonnage resources   on the Brucejack Property. The program included drilling, rock-chip and   channel sampling, and re-assaying of historical drill core pulps. Silver   Standard retained GeoSpark to assess the integrity of the historical   (pre-2009) drilling on the Brucejack Property (Vallat 2009). Results of this   work confirmed that assay data from the majority of the historical drillholes   on the Brucejack Property (849 out of 901 holes targeting the West Zone,   Galena Hill Zone, SG Zone, Shore Zone, and vicinity) were suitable for use in   geological modeling and resource estimation. Field work included the   collection of 2,739 rock-chip and channel samples from the Galena Hill Zone,   Bridge Zone, SG Zone, and Mammoth Zone, as well as at the Hanging Glacier   Zone, where historical surface sampling had identified rocks enriched in gold   and silver. A total of 17,964 m in 37 diamond drillholes were completed   during the 2009 field season. Twelve drillholes were targeted at what would   become the Valley of the Kings Zone. Drillhole SU-012 (Figure 6-1) is   credited as being the discovery drillhole for the Valley of the Kings Zone   intersecting 16,948.5 g/t Au over 1.5 m. Other notable drillhole   intersections that suggested the presence of 6-2 Date Exploration 1991 and   1992 Newhawk officially subdivided the Sulphurets claim group into the   Sulphside, Snowfield, and Bruceside Properties in 1991, and sold the   Sulphside Property (including the Sulphurets Zone and Mitchell Zone) to   Placer Dome Inc. (Placer Dome) in 1992. Newhawk continued exploration of the   Bruceside Property between 1991-1994, including property-wide trenching;   mapping; airborne surveys; and surface drilling, evaluating various surface   targets including the Shore Zone; Gossan Hill Zone; Galena Hill Zone; Maddux   Zone; and SG Zone targets. Six holes were drilled at the Shore Zone,   totalling 1,200 m, to test its continuity and to determine its relationship   to the West Zone and R-8 Zone. Results varied from 37 g/t Au over 1.5 m, to   13 g/t Au over 4.9 m (Payie 2017). Newhawk purchased Granduc’s interest in   the Snowfield Property in early 1992. 1993 A LOM Development Certificate was   issued to Newhawk for the West Zone by the provincial government (under the   BC Environmental Assessment Office (EAO); certificate 92-06). 1994   Exploration on the Bruceside Property consisted of detailed mapping and   sampling in the vicinity of the Gossan Hill Zone, and 7,352 m of diamond   drilling (in 20 drillholes) primarily on the West Zone, R-8 Zone, Shore Zone,   and Gossan Hill Zone targets. Mapping, trenching, and drilling were completed   on the ten best and highest priority targets (including the West Zone). 1996   Granduc merged with Black Hawk to form Black Hawk Mining Inc. (Black Hawk).   The Mine Development Certificate, renewed until 1998, was replaced by a   Project Approval Certificate (M98-03). 1997 and 1998 No exploration or   development work was carried out on the Snowfield and Bruceside properties   (Budinski et al. 2001). 1999 Silver Standard acquired Newhawk and with it,   Newhawk’s 100% interest in the Snowfield Property and 60% interest in the   Bruceside Property, and created separate projects for the Snowfield and   Brucejack deposits (Payie 2017). 1999 to 2001 No exploration or development   work was carried out on the Snowfield and Brucejack properties. 2001 Silver   Standard entered into an agreement with Black Hawk whereby Silver Standard   acquired Black Hawk’s 40% direct interest in the Bruceside Property, giving   Silver Standard a 100% interest in the Bruceside Property, which it   subsequently renamed the Brucejack Property. Black Hawk retained a 1.2% NSR   royalty on the Bruceside Property. 2001 to 2008 No exploration or development   work was carried out on the Snowfield and Brucejack properties during the   period from 1999 to 2008. The Project Approval Certificate was amended in   January 2004 and expired in September 2006. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE a gold deposit in the Valley   of the Kings Zone included: 5,344 g/t Au over 0.5 m (SU-029), 184.5 g/t Au   over 1.5 m (SU-006), 51.1 g/t Au over 1.5 m (SU-035), 47.5 g/t Au over 1.5 m   (SU-033), and 46.1 g/t Au over 1.5 m (SU-017). Figure 6-1: Visible Electrum   in Valley of the Kings Zone Discovery Drillhole SU-012 Source: Note: Pretivm   Dendritic latticework electrum in quartz-carbonate vein in HQ diameter core   (drillhole SU-012). The 2010 drill program, which totalled 33,480 m in 73   drillholes, was designed to continue definition of bulk tonnage   mineralization on the Brucejack Property and to determine the nature and   continuity of the high-grade mineralization intersected in the Valley of the   Kings Zone. Approximately one third of the 2010 drilling targeted the Valley   of the Kings Zone and included gold intersections of up to 5,850 g/t Au over   1.5 m (SU-040). The bulk tonnage drilling achieved its intended goal when a   sizeable Mineral Resource was estimated for the Brucejack Property (Ghaffari   et al. 2011). The Mineral Resource estimate included the West Zone, West Zone   Footwall Zone, Shore Zone, Gossan Hill Zone, Galena Hill Zone, SG Zone, Valley   of the Kings Zone, Bridge Zone, and the Bridge Zone Halo, and was reported at   a cut-off of 0.30 g/t AuEq inside an optimized open pit shell (Ghaffari et   al. 2010b; 2011). This estimate is no longer current. The relatively dense   drilling from the bulk tonnage drilling program, with drill spacings of 100 m   by 100 m to 50 m by 50 m, formed the basis upon which the bulk tonnage   resource model was built. Numerous high-grade intervals were intersected as   part of this drilling, which allowed for the initial delineation of   high-grade mineralization trends and preliminary domain definition in the   Valley of the Kings Zone. These included: 5,850 g/t Au over 1.63 m (SU-040)   536 g/t Au over 0.57 m (SU-040)   5,480   g/t Au over 0.43 m (SU-084) 430 g/t Au over 0.50 m (SU-040)   2,490 g/t Au over 1.59 m (SU-054) 231 g/t   Au over 1.50 m (SU-046)   1,025 g/t Au   over 1.50 m (SU-053) 182.5 g/t Au over 0.50 m (SU-077)   6-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE 171 g/t Au over 0.68 m (SU-106) 92.5 g/t Au   over 1.50 m (SU-106)   170.5 g/t Au   over 0.50 m (SU-058) 83.4 g/t Au over 1.50 m (SU-086)   164.5 g/t Au over 0.50 m (SU-058) 53.7 g/t   Au over 1.50m (SU-056)   131 g/t Au   over 1.00 m (SU-093) 50.0 g/t Au over 1.50 m (SU-055).   Subsequent drilling programs conducted by   Pretivm have focussed on further delineating the corridors of high-grade   mineralization in the Valley of the Kings Zone. Additional details relating   to Silver Standard’s 2009-2010 Brucejack Property exploration and drilling   programs are summarised in Ghaffari et al. (2010a; 2011) and Board and   McNaughton (2013). In 2010, Silver Standard sold the Snowfield and Brucejack   properties to Pretivm, a start-up company formed by the former president   specifically to acquire the properties. 6.3 Previous Feasibility Studies on   the Property (1990) Corona Corporation (Corona) completed a FS on a proposed   underground mine with decline access for the Sulphurets Project (West Zone and   R-8 Zone only) in 1990 (Corona 1990). Total operating costs of $145/t were   estimated based on a 350 t/d mill facility for processing and resulted in a   capital cost estimate of $42.7 million with a 6.7% pre-tax return at a price   of US$400/oz Au and $5/oz Ag. The study concluded that higher metal prices   were needed before a production decision could be taken. The reader is   cautioned that the Corona Sulphurets Project Feasibility Study (Corona 1990)   is no longer relevant, is not NI 43-101 compliant, and should not be relied   upon. 6.4 Prior Mineral Production In the 1980s, more than 5 km of   underground ramps, level development, and raises were completed on the West   Zone down to the 1100 Level. In 1993, a Project Approval (LOM Development)   Certificate was issued for the Brucejack Property by the Minister of   Sustainable Resource Management and Minister of Energy and Mines for the   Province of BC. The mine was not developed further, and the certificate   expired in 2006. Prior to Pretivm’s Bulk Sampling Program conducted in 2013,   no ore had been processed from the Brucejack Property, including from the   West Zone. 6.5 Preliminary Economic Assessment (2010) Silver Standard   commissioned Wardrop Engineering Inc. (Wardrop; now Tetra Tech) to complete a   preliminary economic assessment (PEA) on the combined bulk-tonnage resources   of the Brucejack and Snowfield properties in 2010 (Ghaffari et al. 2010a).   Based on the results of the PEA, it was recommended that Silver Standard   continue with the next phase, a prefeasibility study, in order to identify   opportunities and further assess bulk-tonnage viability of the two projects.   The PEA was revised and re-issued to Pretivm as two separate documents: one   for the combined Snowfield-Brucejack Property in October 2010 (Ghaffari et al.   2010b), and the other for the Brucejack Property as a standalone project in   June 2011 (Ghaffari et al. 2011). However, these reports are no longer   current. 6-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE The Brucejack Gold-Silver Deposit (the   Brucejack Deposit) is currently defined as incorporating the West Zone and   the Valley of the Kings Zone. A brief overview of the geological setting and   mineralization of the Brucejack Deposit is presented in this section to   provide context for Pretivm’s approaches to geological modelling, resource   estimation, and mining. The information presented in this section has been   excerpted from Roach and Macdonald (1992), Board and McNaughton (2013), Jones   (2014), Board et al. (2017), Tombe et al. (2018), McLeish et al. (2019), and   Board et al. (submitted). Readers interested in additional detail on the   geology of the Brucejack Deposit should refer to these documents. 7.1 Regional   Geological Setting The Brucejack Deposit is situated on the western side of   the Stikine Terrane (Stikinia; Figure 7-1) of the Canadian Cordillera.   Stikinia is the largest and westernmost of several exotic terranes in the   Intermontane morphogeologic belt of the Canadian Cordillera (Monger and Price   2002). Stikinia is interpreted as a Philippine-style intra-oceanic island arc   terrane, formed between mid-Palaeozoic to Middle Jurassic time, when it was   accreted to the North American continental margin (at about 173 Ma; Nelson   and Colpron 2007; Evenchick et al. 2007; Gagnon et al. 2012). Western   Stikinia was subsequently affected by thin-skinned deformation during   Cretaceous accretion of the outboard Insular Belt terranes (at about 110 Ma;   Evenchick 1991; Kirkham and Margolis 1995). The deposit is located in the   northern part of the northwest-trending Stewart-Iskut Culmination, a major   structural feature in western Stikinia that lies between the Stikine and   Skeena Arches to the west of the Bowser Basin (Figure 7-1). The Stewart-Iskut   Culmination has variably been interpreted as a structural culmination that   formed in response to Cretaceous deformation and, more recently, as having   been an Early Jurassic structural highland upon which rocks of the Hazelton   Group were deposited prior to Stikinia being accreted to the western North   American continent (Nelson and Kyba 2014). The culmination contains an   exceptionally metal-rich tectonic assemblage hosted in volcano-sedimentary   and related comagmatic plutonic rocks of the Triassic Stuhini and latest   Triassic to Middle Jurassic Hazelton Groups (Figure 7-2; Nelson et al. 2013).   This area includes structurally-controlled high-potassic calc-alkaline   porphyry copper-gold deposits (e.g., Kerr, Sulphurets, Mitchell, Iron Cap, Snowfield),   transitional epithermal intrusion-related precious metal deposits (e.g.,   Brucejack, Silbak-Premier, Big Missouri, Red Mountain, and Homestake Ridge),   and volcanogenic massive sulphide deposits (e.g., Granduc, Dolly   Varden-Torbrit, Anyox, and Eskay Creek). These deposits are considered to   have been formed while Stikinia was in a state of compression or sinistral   transpression (Nelson and Colpron 2007). 7-1 7.0GEOLOGICAL SETTING AND   MINERALIZATION 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 7-1: Regional   Geological Setting of the Brucejack Deposit -,........o--pid Q-o(-... -..   ---Tr.....: I or 'I - - .,... '" .. l Oco....cpto<NU 1r><1   bl\•""' ,..,.,,.. ""' .Mwnulr\ (lfUAWI l<n-or Corot   n<f'tM .rrw.cy cc c.dw ...... - ;::r:""0..... /'"'>.....   WI Wit All .....­ D CJ ................_""" a) b) Note: The   Brucejack Deposit is located on the western side of the Stikine Terrane   (Stikinia). The deposit is hosted in Lower Jurassic volcanic arc rocks on the   northern side of the Stewart-lskut Culmination, to the west of the Bowser   Basin. Detail inside rectangular outline provided in Figure 7-2. Sources:   Ghaffari et al. (2012) and Jones (2014) I'1\:I TETRA TECH 7-2   N.....""" -,.-.-..C...!.o..l.&,.-:·'l:­   -*""<_...., ... \ . ,:,. - -QOo   s:·-Ill...,._""""IAit toldo llilt .a. -.: 0..._tO.O 20._0   _J,00\ ""I,,.. t::J 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE 7.2 Local Geology The Brucejack Deposit, part   of the Sulphurets Mineral District, is located on the eastern limb of the   north-plunging McTagg Anticlinorium, the northern closure of the   Stewart-Iskut Culmination (Figure 7-2). Volcanic arc-related rocks of the   Triassic Stuhini Group form the core of the anticlinorium, and are   successively replaced outwards by volcanic arc-related rocks of the Jurassic   Hazelton Group and clastic basin-fill sedimentary rocks of the Middle   Jurassic to Lower Cretaceous Bowser Lake Group (Figure 7-3). A major   unconformity separates the Stuhini and Hazelton Group rocks. As a consequence   of its location relative to the axis of the culmination, Brucejack Deposit   rocks are tilted and generally display a progressive younging towards the   east. The Brucejack and neighbouring Kerr-Sulphurets-Mitchell (KSM) deposits   display a strong spatial association to the unconformity between the Stuhini   and Hazelton Group rocks and north-south structures to the east of this   contact (Figure 7-3), suggesting that these features were important for   deposit genesis (Nelson and Kyba 2014). The unconformity between the Stuhini   and Hazelton Groups is associated with numerous Triassic-Jurassic mineral   showings and porphyry copper-gold deposits throughout northwestern BC and is   considered a key feature for mineral exploration in the area (Kyba 2014;   Nelson and Kyba 2014). The KSM copper-gold-molybdenum porphyry deposits are   associated with Mitchell Suite intrusive rocks of the Texas Creek Intrusive   Suite (Kirkham and Margolis 1995). Campbell and Dilles (2017) noted that the   deposits are broadly contemporaneous and have similar mineralogy, alteration,   and textures. They noted that large areas of hydrothermal alteration affected   rocks in and around the Mitchell Suite intrusions, with overprinting   alteration relationships indicating that the magmatic-hydrothermal systems   underwent telescoping as they evolved between about 196 and 190 Ma. Early   syn-mineral potassic alteration was locally overprinted by propylitic,   albitic, and chlorite-sericite alteration, before being pervasively   overprinted by quartz-sericite-pyrite (phyllic) alteration. Final stage   system telescoping included local advanced argillic alteration and massive   pyrite vein emplacement (Mitchell) overprinting earlier assemblages before   being overprinted by high-level gold-rich veins (Campbell and Dilles 2017).   West-directed thrusts and west-vergent overturned folds affect rocks on the   western limb of the anticlinorium, whereas rocks on the eastern limb display   east-to southeast-directed thrusts and east-vergent overturned folds (Kirkham   and Margolis 1995). These structures have been kinematically linked to the   mid-Cretaceous Skeena Fold and Thrust Belt. In addition to the thrust faults,   the McTagg Anticlinorium is cut by late-stage brittle faults that are likely   of Tertiary age and which represent reactivated older structures (e.g., the   north-trending Brucejack Fault; Nelson and Kyba 2014; Board et al.   submitted). A penetrative foliation of variable orientation is preferentially   developed in altered Hazelton Group rocks in the Sulphurets mineral district,   with fabric intensity proportional to mica and/or clay mineral content   (Kirkham and Margolis 1995). Timing of penetrative fabric development is   difficult to ascertain due to the absence of unambiguous cross-cutting   relationships and appropriate non-reset geochronologic data. Although it is   most commonly considered to have developed in response to the mid-Cretaceous   Skeena Fold and Thrust Belt deformation (Kirkham and Margolis 1995; Nelson   and Kyba 2014), the possibility that it is a reactivated composite fabric   recording older deformation events cannot be ruled out (Margolis 1993; Roach   and Macdonald 1992; Tombe et al. 2018; Board et al. submitted). Rocks in the   Sulphurets Mineral District are affected by regional sub-greenschist facies   metamorphism, which is associated with development of the mid-Cretaceous   Skeena Fold and Thrust Belt (Alldrick 1993). Maximum temperatures and   pressures reached approximately 290oC and 4.5 kbar, respectively,   corresponding to thermally reset potassium-argon (K-Ar) and argon-argon   (Ar-Ar) ages for foliation-parallel sericite in older porphyry-related   phyllic alteration zones at approximately 110 Ma (Alldrick 1993; Kirkham and   Margolis 1995). 7-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-2: Select Mineral   Showings and Deposits in the Stewart-Iskut Culmination, Highlighting the   Metal-rich Nature of this Structure Note:Pretivm’s Brucejack and Snowfield   Deposits are located towards the north of the culmination. Detail inside   rectangular outline presented in Figure 7-3. Source: Ghaffari et al. (2012)   7-4 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 7-3: District-scale   Geological Setting of the Brucejack Deposit on the East Side of the McTagg   Anticlinorium (uPPer Haz.efton Groupl Brucejack Project Deposit Locations   Note:Detail inside rectangular outline presented in Figure 7-4. Source: Jones   (2014) I'1\:I TETRA TECH 7-5 LEGEND Middle to Upper Juc Bowser t.ak;; Group   Middle .IUl'"assic lskut River fonnation Late Triassic to Earlv Jurassic   intrusive rods Lower to Midd.e Jurassic Haz lton Group Upper Triassic Group   Fault Fold axial uace 0km 5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 7.3 Brucejack Project Area   Geology The Brucejack Project area is largely underlain by   volcano-sedimentary rocks of the Lower Jurassic Hazelton Group (Figure 7-4).   These rocks unconformably overlie volcanic arc sedimentary rocks of the Upper   Triassic Stuhini Group along the western-most part of the Brucejack Project   area. The rocks are variably altered and deformed, with zones of intense   quartz-sericite-pyrite (phyllic) alteration being associated with increased   deformation due to preferential strain partitioning in sericite-rich zones. A   north-south trending, broadly arcuate, concave-westward 0.5 to 1.5 km wide   band of variably phyllic-altered rocks and associated quartz stockwork   extends over 5 km across the Brucejack Property area (Figure 7-4). The band straddles   the Brucejack Fault across the Brucejack project area, shifting from the west   side of the fault in the north of the Brucejack Project area to the fault’s   east side further south. The phyllic alteration typically contains between   two and 20% pyrite, affects rocks from the bottom to the top of the   lithological sequence (see Section 7.3.1), and, depending on the alteration   intensity, can preclude protolith recognition. More than 40 mineralization   showings, associated with the alteration band, have been identified on the   Brucejack Project area, highlighting the exceptional exploration potential of   the area (McPherson 1994; Board et al. submitted). Ten mineralized zones are   currently recognized on the Brucejack Project area, extending from the   Hanging Glacier Zone in the north to the Bridge Zone in the south (Figure   7-5). Although five of these zones have been explored in some detail (West   Zone, Valley of the Kings Zone, Bridge Zone, Gossan Hill Zone, and Shore   Zone), mining is focused on just the two zones for which there are current   Mineral Resources and Reserves: the Valley of the Kings Zone and the West   Zone. This Technical Report focuses on the Valley of the Kings Zone and West   Zone, with additional details on the Bridge Zone, Gossan Hill Zone, and Shore   Zone provided in Jones (2012c). 7-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 7-4: Geological Map of   the Brucejack Project Area Showing Location of Mineralized Zones and their   Association with the Band of Quartz-Sericite-Pyrite Alteration (shown in   yellow) i Note:Enlarged legend provided in Figure 7-5 Source: Jones (2014)   ['n;ITETRA TECH 7-7 426000 426000 427000 428000 420000 §...§ • et..-=-=>   425000 427000 428000 420000 N 1 =-==-=- -11:... !!1---PRE-TI V-M- 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-5: Brucejack   Property Geology Legend for Figure 7-4 figure continues... 7-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-5 (cont’d) Brucejack   Property Geology Legend for Figure 7-4 figure continues... 7-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-5 (cont’d) Brucejack   Property Geology Legend for Figure 7-4 7.3.1 Lithology The key lithologic   sequence hosting the Brucejack Deposit is characterized by a basal marine   volcanosedimentary (VSF) package unconformably overlain by an immature   polylithic volcanic conglomerate (Cong) that grades upward through a sandy   epiclastic unit (Trans) into a predominantly pyroclastic trachyandesite   (latite) fragmental unit (Andx) (Figure 7-6; Board et al. submitted). This   simplified lithologic sequence represents a relatively complex volcanic   stratigraphy characterized by rapid lateral facies changes, which defines a   general younging direction upward and to the east, and which is interpreted   as having been deposited in a series of small fault-bounded half-grabens on   the eastern side of the Brucejack Fault (Figure 7-6). The Brucejack Deposit   lithologic sequence is bounded to the south and northwest by massive and relatively   fine-grained plagioclase feldspar±potassium feldspar±hornblende-phyric rocks   (P1 porphyry) of the Bridge Zone and Office porphyries (Figure 7-6). The   Office P1 and Bridge Zone P1 porphyry bodies display sharp contacts with the   volcaniclastic rocks and have been variably interpreted as comagmatic   subvolcanic/hypabyssal monzonitic intrusions or latite flows (Kirkham and   Margolis 1995; Jones 2014). Coarser-grained feldspar-hornblende-phyric   porphyry rocks (P2 porphyry) are locally present within the sequence,   especially to the north and east of West Zone. East of the Brucejack Deposit,   in the Flow Dome Zone, the lithologic sequence is overlain by a felsic unit   that includes potassium feldspar±plagioclase feldspar±hornblende-phyric   flows, breccia, bedded nonwelded and welded felsic tuffs, and a comagmatic   intrusion which is flow-banded and plagioclase-hornblende phyric (Figure 7-4;   Macdonald 1993). This unit is interpreted as a flow-dome complex,   representing high-level intrusive and extrusive parts of a local magmatic   center. 7-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-6: Three-dimensional   Block Geological Interpretation Through the Brucejack Deposit, Showing Key   Geological, Structural, and Mineralization Relationships Developed in the   Valley of the Kings Zone and West Zone Source: After Board et al.   (submitted). Dated February 2019. Hydrothermal breccia bodies are present   throughout the lower Hazelton Group rocks on the Brucejack Project area and   follow faults and fractures. The breccia bodies are generally 2 to 15 cm wide   and consist of angular to subrounded wall-rock fragments set in a   fine-grained matrix of rock flour and pyrite. Wall-rock fragments are   heterolithic and commonly derived from the immediate host rock. Hydrothermal   breccia bodies cut all host-rock units and are discordant to the penetrative   foliation. Mineralized veins cut and are cut by breccia bodies and   hydrothermal breccia grades into mineralized manganese-carbonate veins (see   Section 7.3.5), suggesting that the breccia bodies are syn-mineralization in   timing. Relatively uncommon post-mineralization altered amygdaloidal   intermediate to mafic dikes cut all lithological units, mineralized veins,   and vein stockwork of the Brucejack Deposit (Figure 7-6; Tombe et al. 2018;   Board et al. submitted). The dikes are subvertical, up to 1.5 m wide, and   commonly east-to southeast-trending. Dikes in the Valley of the Kings Zone   strike east to east-southeast, have a strike length of at least 900 m, and   extend for more than 1,000 m down dip. Dikes in the West Zone trend   northwest-southeast, have strike lengths of at least 500 m, and extend for   more than 450 m down dip. The dikes follow faults and fractures in staggered   zig-zag patterns, having been emplaced along variably oriented structures   during local extension. Dike emplacement partially utilized 7-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE the same structures as the   mineralized veins. The dikes are undeformed to weakly deformed and generally   discordant to the dominant foliation. The dikes are interpreted to have been   emplaced during a period of rifting post-epithermal mineralization and are   not related to gold mineralization. Late-stage, undeformed, and unaltered   mafic dikes (up to several meters wide) are present to the west of and along   the Brucejack Fault, but are rare on the Brucejack Project area. The   north-trending dikes are subvertical and cut all host rock units, alteration,   mineralization, foliation, post-mineralization intermediate to mafic dikes,   and thrust faults. They are geochemically distinct from the   post-mineralization intermediate to mafic dikes (Tombe 2015). 7.3.2   Geochronology Detailed geochronological work conducted on the Brucejack   Project area, which has included uranium-lead (U-Pb) on zircon,   rhenium-osmium (Re-Os) on molybdenite, and Ar-Ar on sericite/muscovite   (Kirkham and Margolis 1995; Tombe et al. 2018; Board et al. submitted),   indicates that the Brucejack Deposit lithological sequence is between about   195 and 184 Ma in age: the VSF unit is dated at 195 to 188 Ma, the Cong and   Trans units were formed between about 188 and 185 Ma, the Andx unit formed at   about 185 to 184 Ma. The Office P1 porphyry is dated at about 194 Ma, and the   Bridge Zone P1 porphyry is dated at about 189 Ma. Both intrude rocks of the   VSF. Molybdenite mineralization associated with the Bridge Zone P1 porphyry   was formed between about 190 and 189 Ma. The Office and Bridge Zone porphyry   rocks are similar in age and geochemistry to the KSM intrusive rocks (196 to   190 Ma) and are likely related to the Mitchell Intrusive Suite (Board et al.   submitted). Mineralized veins in the Brucejack Deposit (Section 7.3.5) cut   the 188 to 184 Ma lithological sequence that hosts the Brucejack Deposit, and   are cut by the intermediate to mafic dikes, which are dated at about 183 Ma.   The mineralized veins cut rocks as young as about 184 Ma thereby indicating   an age of about 184 to 183 Ma for the precious metal mineralization in the   Brucejack Deposit. The Brucejack mineralization is clearly significantly   younger than the KSM magmatic-hydrothermal system, and this has triggered   near-mine exploration in search of the causative system (see Section 9.2).   Ar-Ar ages of sericite at about 110 Ma indicate isotopic resetting during low   grade regional metamorphism associated with the mid-Cretaceous deformation   event. The undeformed and barren late mafic dikes are considered to be   Tertiary in age (Tombe et al. 2018). 7.3.3 Structure Reactivation of older   basement structures is considered to have played an important role in   controlling magmatic and hydrothermal system development in the Sulphurets   mineral district (Nelson and Kyba 2014). The Brucejack Fault, the largest of   numerous north-south lineaments that occur on the Brucejack Project area, is   interpreted as the latest expression of a reactivated growth fault that was   active during Early Jurassic volcanism and mineralization. Evidence for this   includes: There is a significant change in thickness of the lowermost units   of the lower Hazelton Group over short distances across the fault (Jones   2014; Tombe et al. 2018) The development of small secondary half-graben   structures along the eastern side of the fault that are filled with locally   derived, immature clastic detritus The presence of abundant short-scale   facies variations in the half-graben basins, indicating rapid infilling.   Alteration and mineralization are broadly cospatial with the fault along its   entire 11 km strike length, from Bridge Zone in the south through to Iron Cap   in the north (Nelson and Kyba 2014) Multistage vein stockwork and vein   breccia occur along half-graben normal faults, indicating reactivation of   lower order structures.      7-12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Latest movement on the   Brucejack Fault on the Brucejack Property is dextral and east block down,   with displacement on the order of tens of meters. A post-alteration,   composite penetrative foliation is variably developed in rocks in the   Brucejack Project area, with foliation intensity being closely associated   with phyllic alteration intensity. The foliation is characterized by two   predominantly east-to east-southeast-striking, slightly oblique steeply   dipping foliations (S1 and S2), which are cut by a later north-striking,   steeply dipping S3 foliation (Davis 2017). Progressive deformation has   commonly resulted in S1 being rotated into parallelism with S2 in higher   strain zones, forming a composite S1-S2 cleavage (Davis 2017). S3 cuts the   S1-S2 foliation at high angles, with crosscutting relationships suggesting   its formation during sinistral transpression (Davis 2017). Mineralized veins   (see Section 7.3.5) in the Brucejack Deposit predominantly strike southeast   to east-southeast (more than 90% of all mineralized veins), with east-west   and north-south striking veins being uncommon to rare (Figure 7-6). The   mineralized veins occur as multistage thin sheeted veins, vein breccia, and   vein stockwork, which anastomose and grade vertically and laterally into one   another along fractures, faults, foliation planes, lithological contacts, and   shears defining internally complex vein system structural corridors of   between approximately 5 and 30 m wide. The veins range from being relatively   undeformed to locally moderately deformed, and display both   foliation-parallel and low-to moderate-angle foliation-discordant   relationships, irrespective of rock competency and strain intensity (Tombe et   al. 2018; Roach and Macdonald 1992; Board et al. submitted). Both extensional   and shear vein features are developed in areas of differential strain   partitioning throughout the deposit, with later mineralized veins being less   deformed than earlier mineralized veins (Harrichhausen et al. 2016; Davis   2017; Tombe et al. 2018). A late-to post-deformation structural origin is   envisaged for the mineralized veins, with fluid influx and hydrothermal   alteration coeval with, and outlasting, ductile deformation and associated   periodic brittle failure evolving in response to progressive sinistral   transpression (Roach and Macdonald 1992; Davis 2017; Board et al. submitted).   The post-mineralization intermediate to mafic dikes are generally undeformed,   unfoliated, and cut all lithological units, mineralized vein generations, and   the S1, S2, and S3 fabrics, placing a minimum age of about 183 Ma on   foliation development (Tombe et al. 2018; Board et al. submitted). Localized   fabric development is present in weakly altered dikes, suggesting that the   dikes formed during the waning stages of the alteration and deformation   events. The dikes display apparent gentle warping about north-trending axes   at the deposit scale, small sharp m-scale offsets along late-stage reverse   faults, and retain their planar shape vertically over at least 900 m in the   Valley of the Kings Zone (Figure 7-6). These features suggest that the   intermediate to mafic dikes were subjected to limited post-emplacement   deformation. Post-mineralization reverse and thrust faulting is developed   throughout the Brucejack Deposit. The brittle structures cut all host-rock   lithological units, alteration assemblages, mineralized veins, and   intermediate to mafic dikes, but are cut by the late mafic dikes, indicating   that the causative deformation occurred after about 183 Ma. High-and   low-angle reverse faults are generally southwest dipping, with a   top-to-the-northeast sense of movement in the Brucejack Deposit. Barren, low   angle, chlorite-bearing shear veins, tension gash veins, and undeformed, en   echelon, sub-horizontal quartz veins are associated with the faults, as are   local top-to-the-southwest back thrusts. Fault displacement is relatively   minor (m-scale), indicating limited shortening during the thrust-related   deformation. The post-mineralization faulting is considered to be   mid-Cretaceous in age (about 110 Ma) based on kinematic similarities to   structures in the Skeena Fold and Thrust Belt (Evenchick 1991) and Ar/Ar   geochronology (Tombe et al. 2018). 7-13 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 7.3.4 Alteration Phyllic   (sericite) alteration is the dominant alteration style on the Brucejack Project   area and is typically a fine-grained admixture of white mica (muscovite),   pyrite, quartz, and calcite that replaces the matrix of the   volcanosedimentary rocks, varying in intensity from trace to complete   replacement. Relicts of earlier-formed alteration (e.g., potassic, albitic,   propylitic) are locally preserved in the intensely phyllically altered rocks,   indicating that the phyllic alteration overprinted earlier alteration   assemblages and that the hydrothermal system (or systems) that drove this alteration   was (were) likely telescoping. Weak silicification has affected most of the   host lithological units in the Brucejack Deposit, with moderate to intense   texture destruction occurring locally. Pod-like zones (meters-to   tens-of-meters in size) of intense silicification are commonly developed in   the polylithic conglomerate (especially at its upper and lower contacts) and   locally in rocks of the underlying VSF unit (Figure 7-6). Zones of intense   silicification consist of microcrystalline quartz, pyrite, and sericite, and   are associated with horizons of massive pyrite and almost monomineralic green   muscovite. Irregular stockworks of unmineralized cloudy to translucent quartz   veinlets of varying intensity are limited to the more intensely silicified   zones, and are thought to be related to their formation. Hairline, clear,   crack-seal quartz veinlets are locally present in the hardest and most   intensely silicified zones, possibly reflecting local fluid overpressures   developed beneath these impermeable features. Cross-cutting relationships   between mineralized veins and altered wall rock indicate that the phyllic and   silica alteration predated all stages of electrum mineralization (Tombe et   al. 2018). Spatial and textural associations between pyrite, sericite, and the   silicified zones suggest coeval formation. Mineralized veins and the 183 Ma   intermediate to mafic dikes are generally spatially associated with the   phyllic assemblage, suggesting that these structures preferentially utilized   pre-altered zones. 7.3.5 Mineralization Visible gold and silver   mineralization in the Brucejack Deposit occurs as electrum and is   predominately hosted in quartz-carbonate to carbonate vein and vein breccia   structural corridors within broader stockwork zones (Section 7.3.3; McPherson   1994; Kirkham and Margolis 1995; Tombe et al. 2018; Board et al. submitted).   Additionally, low-grade (less than 5 g/t) gold mineralization occurs   sub-microscopically in vein-and wall rock-hosted arsenian pyrite (invisible   gold) throughout the Valley of the Kings Zone and possibly within the West   Zone as well. Electrum-bearing quartz-carbonate veins and stockwork overprint   and are co-spatial with earlier porphyry-related phyllic alteration in the   Brucejack Deposit. The Valley of the Kings Zone is currently defined over   1,200 m in east-west extent, 700 m in north-south extent, and 650 m in depth.   Deep drilling has indicated that the alteration, mineralization, and veining   in this zone extend to a depth of at least 1,100 m. Mineralization in the   Valley of the Kings Zone is open to the east, west, and at depth. Deep   exploration drilling conducted under the Flow Dome Zone in 2018 (Section 9.2)   was successful in confirming the presence of Valley of the Kings Zone-style   mineralization from the eastern edge of the Valley of the Kings Zone to   beneath the Flow Dome Zone, which lies approximately 1,000 m further east.   The West Zone is currently defined over 590 m along its northwest strike, 560   m across strike, and down to 650 m in depth, is open to the northwest, southeast,   and at depth to the northeast. The Valley of the Kings Zone contains higher   gold and lower silver grades than the West Zone. Precious metal   mineralization is ubiquitous throughout the vein systems (Figure 7-7);   however, its continuity is not correlated to any specific geologic   continuity; although mineralized structural corridors can be continuous on   the meters-to tens-of-meters scale, the within-vein gold and silver   distribution is highly erratic. Nevertheless, the distribution and grade of   precious metal mineralization within the mineralized structural corridors   within the broader stockwork system is of significant economic interest   (Figure 7-7). 7-14 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Figure 7-7: Oblique View Down and Towards the   West-Northwest of the Brucejack Deposit Showing Drillhole Intersections   Greater than 5 g/t Gold Relative to Underground Workings in both the Valley   of the Kings Zone and the West Zone Source: Pretivm (2019) 7.3.5.1 Valley of   the Kings Zone Six stages of veining have been recognized in the Valley of   the Kings Zone (Table 7-1). Discontinuous, deformed, and variably oriented   pyrite-quartz-calcite stringer veinlets represent the earliest stage of   veining (Stage I). These veinlets are widespread in zones of phyllic   alteration, and may represent D-type veinlets associated with early   porphyry-style alteration (Tombe et al. 2018). Stage II veins are translucent   to white, discontinuous, microcrystalline quartz veinlets found exclusively   within pervasively silicified rocks. Stage I and II veins are pre-mineral   with respect to precious metal mineralization as they are always cut by   electrum-bearing epithermal veins. Electrum mineralization occurs in   quartz-carbonate (Stage III), base metal sulphide-quartz-carbonate (Stage   IV), and manganoan calcite (Stage V) sheeted veinlets, veins, vein breccia,   and vein stockwork (Figure 7-8). Stages III-V veins are considered to have   formed coevally as they display complex multiple overprinting relationships.   Barren, thrust-related quartz-chlorite veins and tension gashes (Stage VI)   cut all earlier vein generations and are likely mid-Cretaceous in age (Tombe   et al. 2018). Stage III veins increase in abundance at depth, to the west,   and to the east in the Valley of the Kings Zone. Stages III to V veins are   locally undeformed to weakly deformed, but display pinch-and-swell textures   in high strain zones. Classic epithermal vein textures, including crustiform   banding, sparse cockade textures, and vugs are locally present in Stage III   and IV veins (Tombe et al. 2018). Electrum in all mineralized vein stages   occurs in a variety of textures, including: common fine-to coarse-grained   dendrites, lesser amounts of coarse subhedral clots and aggregates, and   uncommon fine-to medium-grained, subhedral to euhedral sheet-to plate-like   crystals. The gold/silver ratio of electrum varies significantly, with each   of the three main mineralized vein stages displaying unique gold/silver   signatures, ranging from 30 to 70% Au. Stage V veins typically contain   electrum with the highest proportion of gold, whereas Stage IV veins contain   predominantly silver-rich electrum that is locally chemically 7-15 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE zoned (gold-rich cores   surrounded by silver-rich rims; McLeish et al. 2018). There does not appear   to be any significant compositional zonation of electrum as a function of   spatial location. Table 7-1: Vein Generations in the Valley of the Kings Zone   Notes: tr. – trace; Apy – arsenopyrite; Cal – calcite; Chl – chlorite; Cpy –   chalcopyrite; Dol – dolomite; El – electrum, Gn – galena; Py – pyrite; Qz –   quartz; Rt – Rutile, Ser – sericite, Sp – sphalerite. Stage I, III, IV, V,   and VI correspond to Vn0, Vn1, Vn2, Vn3, and Vn4 according to the mine vein   nomenclature. Source: Modified after Tombe et al. (2018) and Board et al.   (submitted) 7.3.5.2 West Zone Mineralization and veining in the West Zone   were investigated in the late 1980s and early 1990s by Newhawk and research   geologists (Roach and Macdonald 1992; Macdonald 1993; Davies et al. 1994;   Kirkham and Margolis 1995). These studies documented mineralization and vein   parageneses broadly similar to that described above for the Valley of the   Kings Zone, with two notable exceptions: ore stage veins have a lower modal   abundance of electrum and higher modal abundance of base metal sulphide and   silver sulphosalt minerals and, therefore, a lower gold/silver ratio than   those in the Valley of the Kings Zone, and the mineralogy of   pre-mineralization-stage veining in the West Zone is different to that of the   Valley of the Kings Zone: Stage I veinlets in the West Zone are represented   by potassium feldspar-quartz veinlets. 7-16 Vein Stage Description Timing   Typical Size Mineralogy Metals Gangue I Discontinuous stringer veinlets   Pre-mineral Thickness: mm Continuity: cm Invisible Au in Py tr. Cpy   Py-Qz-Cal-Ser±Chl II Discontinuous translucent veinlets Pre-mineral   Thickness: mm Continuity: mm - Qz-Py III IIIa: sheeted veinlets Syn-mineral   Thickness: cm Continuity: dam El, tr. Sp±Gn±Cpy Py-Qz-Cal-Dol±Ser±Rt IIIb:   breccia/flooded zones Syn-mineral Thickness: cm to dm Continuity: m El, tr.   Sp±Gn±Cpy Py-Qz-Cal-Dol±Ser±Rt IIIc: stockwork veins/blow-outs Syn-mineral   Thickness: dm to m Continuity: dam to hm El, tr. Sp±Gn±Cpy, tr. Ag   sulphosalts Py-Qz-Cal-Dol±Ser±Apy±Rt IV Ag-rich base metal sulphide veins   Syn-mineral Thickness: cm to dm Continuity: m to dam   Sp-Gn-Cpy-El-Ag-sulphide+ sulphosalts: acanthite, pearcite, pyrargyrite,   freibergite, proustite, polybasite, argentotennantite.   Py-Qz-Cal-Dol±Ser±Apy±Rt V Mn-carbonate veins Syn-mineral Thickness: cm to dm   Continuity: m to dam El, tr. Cpy Cal±Qz±Py±Rt VI Tectonic shear/tension gash   veins Post-mineral Thickness: cm Continuity: cm to m - Qz-Cal-Chl 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 7.3.5.3 Genetic   Considerations Previously gold transportation was considered to have occurred   as bi-sulphide complexes in solution (e.g., Board 2015a; McLeish et al. 2018;   2019), with the porphyry-associated pre-sulphidization and pre-sericitization   of the host rock facilitating extended residency time of gold-bearing fluids   due to minimal rock buffering of sulphur by host-rock iron (all taken up in   the form of pre-mineral pyrite) and maintenance of near neutral fluid pH   (muscovite-buffering; Heinrich et al. 2004). Recent work conducted by McLeish   et al. (2018; 2019) has demonstrated that gold (and silver) was being   transported as electrum nanoparticles in suspension (colloids) in association   with carbonate (i.e., likely in the gas phase) rather than silica (quartz).   This allows for increased capacity of mineralizing fluids to carry gold by   physical transport over and above that dissolved in solution. Controls on   gold precipitation from colloidal suspensions include mixing with meteoric   (including heated seawater) waters, decreasing temperature, boiling (to a   lesser extent), and local destabilization near pyrite zones. McLeish et al.   (2019) documented a multiphase history of porphyry to epithermal   mineralization (alluded to in Board (2015a)) in pyrite grains in the Valley   of the Kings Zone and the Flow Dome Zone. Early porphyry-related pyrite is   resorbed and overgrown by gold-bearing arsenian-banded epithermal pyrite.   Similar pyrite growth zonation patterns have been observed in the porphyry to   epithermal transition at the Lihir porphyry-epithermal deposit in Papua New   Guinea (Sykora et al. 2018). Overprinting of earlier porphyry alteration and   mineralization by later co-spatial epithermal events (arsenian pyrite and   subsequent electrum mineralization) complicates domain definition for   geological modelling (see Section 14.3). Mixing with meteoric waters (likely   heated seawater) triggered explosive phreatomagmatic events that resulted in   destabilization of the electrum colloids and their precipitation. This likely   occurred again and again, in different faults, fractures, foliation planes,   and along lithological contacts that were experiencing variable dilation and   closure due to local variations in compressional and extensional stress, and   resulted in the globally ubiquitous, yet locally variable and difficult to   predict distribution of electrum throughout the Brucejack Deposit (Figure   7-8). As a result of the nature of gold transportation (above) and complex   multistage geological history, mineralization continuity appears to better on   the larger (structural corridor) scale than on the local (individual   discontinuous structures) scale. It is difficult to interpret individual   mineralized structures with the information available, whereas it is relatively   easy to model the mineralized structural corridors with a high degree of   confidence. 7-17 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 7-8: Mineralized Veins   in the Valley of the Kings Zone of the Brucejack Deposit Source: Pretivm   (2019) 7-18 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The Brucejack Deposit is   interpreted to be a deformed porphyry-related transitional to intermediate   sulphidation epithermal high-grade gold-silver vein, vein stockwork, and vein   breccia deposit that formed between 184 to 183 Ma (Board and McNaughton 2013;   Tombe et al. 2018; Board et al. submitted). High-grade gold-silver   mineralization was formed in association with a telescoped, multi-pulsed   magmatic-hydrothermal system beneath an active local volcanic center (Board   et al. submitted). The Brucejack Deposit has many characteristics in common   with intermediate sulphidation epithermal systems (Sillitoe and Hedenquist   2003). These are highlighted (in yellow) in Table 8-1. Intermediate   sulphidation epithermal systems occur in calc-alkaline andesite-dacite arcs   and can be spatially associated with porphyry systems and individual volcanic   centers (Sillitoe and Hedenquist 2003). Brownfields exploration drilling from   2018–2019 tested the porphyry potential below the Valley of the Kings Zone   and in the Flow Dome Zone (Section 9.2–9.3). Mineralization in these systems   is overwhelmingly hosted in veins, sheeted veins, vein stockwork, and vein   breccia, with gold-silver occurring as electrum (Sillitoe and Hedenquist   2003). Whilst the majority of these types of epithermal systems form in arcs   with neutral to extensional tectonic environments, Victoria (the gold-rich   type example) and the giant Baguio Au district (both in the Philippines) were   formed in a compressive island arc (Sillitoe and Hedenquist 2003). The   Brucejack Deposit appears to have formed in compressive island arc setting   (Tombe et al. 2018; Board et al. submitted). Intermediate sulphidation epithermal   deposits contain significant quantities of precious metals (Sillitoe and   Hedenquist 2003). Examples of intermediate sulphidation deposits with   significant contained gold include: Rosie (Montana; approximately 414 t Au),   Baguio (Philippines; approximately 400 t Au), Comstock Lode (Nevada;   approximately 260 t Au), Kelian (Indonesia; approximately 240 t Au),   Tayoltita (Mexico; approximately 150 t Au), Sacarimb (Romania; approximately   84 t Au), and Victoria (Philippines; approximately 80 t Au). The Brucejack   Deposit has similarities in terms of vein style, mineralization paragenesis,   and alteration to the Fruta del Norte high-grade gold deposit in Ecuador   (e.g., Leary et al. 2016; greater than 155 t Au) and the Porgera gold deposit   in Papua New Guinea (e.g., Richards and Kerrich 1993; Ronacher et al. 2004;   greater than 660 t Au). Table 8-1: Principal Field-oriented Characteristics   of Intermediate-and Low-sulphidation Epithermal Systems table continues... 8-1   High Sulphidation Intermediate Sulphidation Low Sulphidation Oxidized Magma   Reduced Magma Subalkaline Magma Alkaline Magma Type Example El Indio, Chile   (vein); Yanacocha, Peru (disseminated) Potosí, Bolivia Baguio, Philippines   (Au-rich); Fresnillo, Mexico (Ag-rich) Midas, Nevada Emperor, Fiji Genetically   Related Volcanic Rocks Mainly andesite to rhyodacite Rhyodacite Principally   to rhyodacite but locally rhyolite Basalt to rhyolite Alkali basalt to   trachyte Key Proximal Alteration Minerals Quartz-alunite/APS;   quartz-pyrophyllite/dickite at depth Quartz-alunite/APS; quartz-dickite at   depth Sericite; adularia generally uncommon Illite/smectite-adularia   Roscoelite-illite-adularia andesite 8.0DEPOSIT TYPES 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Note:Key features noted in the Brucejack   Deposit are highlighted in yellow. The presence of adularia in the West Zone   is still in accordance with an intermediate sulphidation classification. APS   – Aluminum-phosphate-sulphate minerals; Sb – Antimony; Hg – Mercury; Zn –   Zinc; Pb – Lead; Bi – Bismuth; W – Tungsten; Sn - Tin Source: Modified after   Table 3 in Sillitoe and Hedenquist (2003). Corbett (2013) generally considers   intermediate sulphidation epithermal deposits as a sulphide-rich sub-type of   low sulphidation epithermal deposits known as carbonate-base metal gold   deposits (Corbett and Leach 1998; Figure 8-1). These types of deposits are   formed from magmatic fluids that evolve to low sulphidation as they migrate from   the intrusive to shallower crustal levels and mix with substantial meteoric   waters (Corbett 2013). Corbett (2013) prefers the use of (sulphide-rich low   sulphidation) carbonate-base metal gold for these types of deposits to   intermediate sulphidation as the former more correctly accounts for the wide   temperature range and paragenetic sequence related to the transition from   intrusion-related quartz-sulphide gold-copper deposits through carbonate-base   metal gold to epithermal gold-silver deposits. Veins in this transition show   a continuum from sulphide-rich (“D-type” veinlets: proximal to porphyry; Vein   Stage I at Brucejack; see Section 7.3.5.1) through 8-2 High Sulphidation   Intermediate Sulphidation Low Sulphidation Oxidized Magma Reduced Magma   Subalkaline Magma Alkaline Magma Silica Gangue Massive fine-grained   silification and vuggy residual quartz Vein-filling Vein-filling crustiform   and colloform chalcedony and quartz; carbonate-replacement texture   Vein-filling crustiform and colloform chalcedony and quartz; quartz   deficiency common in early stages crustiform and comb quartz Carbonate Gangue   Absent Common, Present by typically minor and late Abundant but not   manganiferous typically including manganiferous varieties Other Gangue Barite   common, typically late Barite uncommon; fluorite present locally Barite,   celestite, and/or fluorite common locally Sulphide Abundance 10 to 90 vol % 5   to >20 vol % Typically, <1 to 2 vol % (but up to 20 vol % where hosted   by basalt) 2 to 10 vol % Key Sulphide Species Enargite, luzonite, famatinite,   covellite Acanthite, stibnite Minor to very minor arsenopyrite ± pyrrhotite;   minor sphalerite, galena, tetrahedrite-tennantite, chalcopyrite Main Metals   Au-Ag, Cu, As-Sb Ag, Sb, Sn Ag-Au, Zn, Pb, Au ± Ag Cu Minor Metals Zn, Pb,   Bi, W, Mo, Sn, Hg Bi, W Mo, As, Sb Zn, Pb, Cu, Mo, As, Sb, Hg Te and Se   Species Tellurides common; selenides present locally None known but few data   Tellurides common locally; selenides uncommon Selenides common; tellurides   present locally Tellurides abundant; selenides uncommon Sphalerite, galena,   tetrahedrite-tennantite, chalcopyrite Barite and manganiferous silicates   present locally 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE carbonate (manganese-rich;   Vein Stage V at Brucejack), carbonate-quartz (Vein Stage V at Brucejack), to   quartz-carbonate (distal to porphyry and shallower levels; Vein Stages III   and IV at Brucejack; Corbett and Leach 1998). Considering Corbett’s (2013)   classification, the ubiquitous Vein Stage I veins in the phyllic alteration   throughout the Brucejack Deposit being overprinted by carbonate and   quartz-carbonate veins provides evidence for temperature fluctuations in the   volcanic sequence: a telescoping porphyry system. The presence of increased   carbonate veins at depth (Section 7.3.5.1 of this report) is encouraging as   gold mineralization in the Brucejack Deposit appears to be associated with   the carbon dioxide gas phase (McLeish et al. 2019). Examples of   carbonate-base metal deposits from the southwest Pacific Rim include: Porgera   Waruwari, Hidden Valley, Woodlark, and the Wafi Link Zone in Papua New   Guinea; Cowal, Kidston, Mt Leyshon, and Mt. Rawdon in Australia, Gold Ridge   in the Soloman Islands; Acupan, Antamok, Victoria, and Bulawan in the   Philippines; and Kelian and Mt. Muro in Indonesia (Corbett 2013). Corbett   (2013) considers Fruta del Norte (Ecuador), Golden Sunlight, Montana Tunnels,   and Cripple Creek (USA), Rio Medio and San Cristobal (Chile) to be examples   of carbonate-base metal gold deposits. Examples of quartz-sulphide   gold-copper deposits include Kerimenge and Lihir in Papua New Guinea (Corbett   2013). Interestingly, mixing with substantial meteoric water (seawater due to   caldera collapse) and overprinting of earlier porphyry mineralization by   later epithermal mineralization is recorded at Lihir (Sykora et al. 2018).   Similar features (to those at Lihir) have recently been documented in the   Brucejack Deposit (McLeish et al. 2018; 2019; Board et al. submitted). Figure   8-1: Schematic Section of Calc-alkaline Volcanic Arc Showing High and   Intermediate Sulphidation Epithermal Deposits and Porphyry Deposits   Note:Location of Brucejack Deposit is highlighted in red. Source: Modified   after Figure 3 in Sillitoe and Hedenquist (2003). 8-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 8-2 Conceptual Model   of Different Arc-related Porphyry and Epithermal Copper-Gold-Silver   Mineralization Deposits Note: Source: Interpreted position of the Brucejack   Deposit is highlighted in transparent red ellipse. Modified after Figure 1 in   Corbett (2013). 8-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 9.1 Exploration – 2011 to   2014 Following acquisition of the Brucejack Property in late 2010, Pretivm   management changed the exploration focus from an open-pit bulk-tonnage   approach to targeting high-grade resources amenable to more selective   underground mining. Surface and underground drilling was the main tool used   in the exploration of the Brucejack Deposit and Property between 2011 and   2014. Geophysical surveys were conducted in 2014 to assess the exploration   potential on the Brucejack Property and broader claim block scales. Table 9-1   provides a summary of the exploration carried out on the Brucejack Property   between 2011 and 2013 by Pretivm. Additional detailed information on   Pretivm’s 2011–2014 exploration of the Brucejack Property is provided in   Jones (2014) and Ireland et al. (2014). Table 9-1: Exploration of the   Brucejack Property Between 2011 and 2014 table continues... 9-1 Date   Exploration 2011 A bulk-tonnage resource update was released in February 2011   (Ghaffari et al. 2011), with an initial high-grade resource for the Valley of   the Kings Zone. An additional high-grade resource estimate, with sensitivity   testing, was released in November 2011 (Armstrong et al. 2011). Brownfields   exploration included detailed surface geological mapping, limited surface   sampling, and limited geophysics (an initial Spartan magnetotelluric survey   conducted by Quantec Geoscience Ltd.; Turkoglu et al. 2011; Ireland et al.   2013). A total of 178 diamond drillholes were completed, totaling 72,805 m.   The program targeted previously defined high-grade intersections primarily in   the Valley of the Kings Zone (60% of the total), but also in the Gossan Hill   Zone, Shore Zone, West Zone, and Bridge Zone targets. Dewatering of the   historical West Zone underground development was carried out to assess the   condition of the workings and determine if the workings could be used as a   launching point for a development drive to the Valley of the Kings Zone. 2012   Detailed brownfields surface geological mapping and associated supplementary   surface geochemical sampling was continued. A total of 301 drillholes were   completed, totaling 105,500 m of drilling during the 2012 drilling program.   Zones within 150 m of surface were drilled at 12.5 m centers, with the deeper   parts (down to about 350 m below surface) being drilled at approximately 25 m   centers. Drilling at greater depths was generally only able to reliably   achieve 50 m centers. The results of the 2012 drilling were incorporated into   a revised Mineral Resource (Jones 2012c). This resource estimate formed the   basis for a feasibility study on the Brucejack Property, which was completed   in June 2013 (Ireland et al. 2013). 2013 A total of 24 surface diamond   drillholes (5,200 m) were completed (drillholes SU-590 to SU-613) on the main   and eastern parts of the Valley of the Kings Zone. An additional 575 m of   shallow geotechnical drilling was conducted in 13 drillholes (drillholes   SU-614 to SU-626). Pretivm extracted a 10,000 t bulk sample to further   evaluate the geological interpretation and Mineral Resource estimate for the   Valley of the Kings Zone (Jones 2014). Geological mapping (face, back, and   ribs), channel, and chip sampling were conducted on a round-by-round basis   for all the underground workings developed as part of the bulk sample. Bulk   sample material from each round (approximately 100 t) was sampled through a   sampling tower and sent as defined rounds to the Contact Mill in Philipsburg,   Montana, for processing. A total of 5,923 oz Au were produced from 10,302 t   of bulk sample material processed through the mill at an average grade of   17.88 g/t Au (Ireland et al. 2014). The results provided confidence in the   November 2012 Mineral Resource and were used for parameter calibration and   confidence classification in the December 2013 Mineral Resource (Jones 2012c;   Jones 2014). 9.0EXPLORATION 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Notes: GPS – Global   Positioning System; MT – Magnetotelluric; AMT – Audio Magnetotelluric; IRIS –   Integrated Radiometric Information System 9-2 Date Exploration 2013 A total   of 16,500 m of underground drilling was conducted to augment the bulk sample   results by drilling off a larger area around the bulk sample workings on the   1,345 m level. Drilling was conducted on approximately 7.5 m centers over an   area of 120 m east-west by 60 to 90 m north-south by 120 m vertically.   Additional underground exploration drilling was conducted to test targets   outside of the bulk sample area. Underground drilling totaled 38,840 m in 409   drillholes. Surface geological mapping and supplementary surface geochemical   sampling was continued, albeit with a more greenfields exploration goal than   in previous years. The majority of this exploration was conducted on   Pretivm’s claims outside of the Brucejack Property area. 2014 Approximately   11,200 m of surface drilling in 12 drillholes (SU-627 to SU-632, SU-640,   SU-644, and SU-650 to SU-653) testing the mineralization potential at depth   beneath the Valley of the Kings Zone was conducted in 2014. Geotechnical   drilling totaled 725 m in 15 drillholes (SU-633 to SU-639, SU-641 to SU-643,   SU-645 to SU-649). An airborne magnetic and radiometric survey was conducted   over the Brucejack Property and the wider Pretivm claim area by Precision   GeoSurveys Inc. (Pezzot 2015). Approximately 750-line km (of a total   1,185-line km) were flown at a 200 m line spacing over the Brucejack Property   (Block 1 of the survey). Line spacings of between 400 and 500 m were flown on   the broader Pretivm claim area (Blocks 2 and 3). A Scintrex Cs vapour CS-3   magnetometer and an IRIS were used to collect the data. Ancillary equipment   included base station magnetometers, a laser altimeter, a Pilot Guidance   Unit, GPS navigation, and an AGIS data acquisition system. Additional Spartan   MT data were acquired from both the Snowfield and Brucejack Properties in   August and September 2014 by Quantec Geoscience Ltd (Tuncer 2014a; b). This   work, which expanded on the 2011 Spartan MT data (Turkoglu et al. 2011), was   aimed at targeting porphyry and epithermal mineralization and improving   geological knowledge on the two property areas. Spartan MT data were   collected over a frequency range of 10 KHz to 0.001 Hz, with AMT data   collected over a frequency range of 10 KHz to 3 Hz, from a total of 78 MT   stations. Following 1D and 3D inversion modelling of the data, a total of ten   conductive feature anomalies were identified, the most significant of these   on the Brucejack Property being beneath the large flow foliated latite dome   to the east of the Valley of the Kings Zone (now known as the Flow Dome   Zone). These features were interpreted as reflecting increased alteration   with abundant sericite content. Results of the geophysical surveys were used   for enhanced structural interpretations as well as porphyry and epithermal   deposit vectoring, targeting, and exploration program planning. A total of   605 surface rock outcrop grab, chip, and channel samples were collected on   the Brucejack Property. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 9.2 Exploration – 2015 to   2018 Pretivm’s main focus between 2015 and 2017 was on the permitting,   financing, construction, and commissioning of the Brucejack Gold Mine.   Brucejack Property exploration between 2015 and 2018, consequently, largely   targeted resource and reserve expansion of the Valley of the Kings Zone   through underground drilling (see Section 10.0). Limited brownfields (near   deposit/mine) exploration conducted on the Brucejack Property included   drilling, geophysics, surface mapping, and very limited surface sampling for   petrography, mineral chemistry, and geochronological analyses. Greenfields   exploration of the broader Pretivm claims also occurred from 2015 through   2018, as part of the Bowser Regional Property (see Flasha 2017a; b; c;   Wafforn 2018a; b). All exploration conducted on the Brucejack Property   (termed brownfields or near-mine exploration) initially followed a model that   suggested the epithermal vein system was genetically linked to the long-lived   KSM porphyry deposits (approximately 196 to 190 Ma; Febbo et al. 2015). The   gold-bearing veins were considered to have been formed in the waning stages of   the telescoping porphyry system, which was interpreted as having lasted from   approximately 191 to 183 Ma (Board and McNaughton 2013). Additional   geochronological data, coupled with detailed geological and geophysical   reviews, resulted in the discovery that rocks as young as approximately 184   Ma were affected by phyllic alteration and cut by auriferous epithermal veins   (Board et al. submitted). As none of the porphyry intrusions recognized to   date in the region were as young as this, an alternative exploration model   was proposed in which a younger porphyry center, as yet undiscovered, was the   driver of the hydrothermal system that was responsible for the formation of   the Brucejack Deposit. Detailed reviews of surface samples, drilling data,   geological mapping, structural data, geophysical data, geochemical data,   alteration intensity, post-mineral dyke orientations, hydrothermal breccia   distribution, and geochronological data appeared to vector to the Flow Dome   Zone in the east. Limited surface exploration drilling (8,380 m in 10   drillholes and two wedges) was conducted on the Brucejack Property in 2015,   with 6,199 m in 8 drillholes (including two wedges) targeting the Flow Dome   Zone. Other zones targeted included the Hanging Glacier Zone (987.33 m in   three drillholes) and one drillhole in the South Zone (southwards from Bridge   Zone; see Flasha 2016). Surface mapping and limited surface sampling of the   Flow Dome Zone augmented the drilling. Results of this drilling highlighted   the continuation of Valley of the Kings Zone style phyllic alteration and   electrum mineralization beneath the main part of the Flow Dome Zone (Figure   9-1), as well as isolated occurrences of relic potassic and propylitic   alteration, bornite, and chalcopyrite. The drilling did not intersect the   interpreted causative porphyry. Additional airborne geophysical surveys (1TEM   electromagnetic, magnetic, and radiometric) were conducted as part of   Pretivm’s claim block-wide airborne survey by Precision GeoSurveys Inc.   between July and October 2015, as a follow-up to the 2014 airborne survey   (see Section 9.1; Boyd and Poon 2015; Poon 2015; Flasha 2016b; c). Although   no new magnetic or radiometric lines were flown over the Brucejack Property   in 2015, 1TEM electromagnetic data were obtained as part of Block 2 of this   survey (Boyd and Poon 2015). The Block 2 survey was flown at a 200 m spacing   between lines, with most of the lines flown in an east-west direction. Two of   six north-south tie lines (spaced at 4,500 m) were flown over the Brucejack   Property. Precision GeoSurveys Inc. used a towed 1TEM structure, 1TEM   transmitter (TX), 1TEM receiver (RX), laser altimeter, data loggers, a Pico   data acquisition system, a Pico pilot navigation unit, and a Honda V-twin gas   engine and alternator system (340 A, 80 V), all installed on its Eurocopter   AS350BA helicopter. The 1TEM structure was towed 40 m below the helicopter at   a nominal height of 50 m above the ground, ranging up to 74.3 m above the   ground in areas of challenging relief. Results of the 1TEM electromagnetic   survey over the Brucejack Property indicated the presence of an extensive   hydrothermal footprint in this area, characterized by elevated conductivity   (Figure 9-2). Known mineralized zones on the Brucejack Property are located   within the elevated conductivity footprint. All of the 2015 surface diamond   drillholes drilled into this footprint intersected extensively altered   (generally phyllic alteration) and anomalously mineralized rocks. The   electromagnetic data are being used in conjunction with other geological and   geophysical data for brownfields exploration targeting. 9-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 9-1: Plan View of the   Brucejack Deposit Showing Significant Electrum Intersections from the 2015   Surface Exploration Drilling of the Flow Dome Zone (1)Outline of Measured,   Indicated, and Inferred Mineral Resource as at July 21, 2016. (2)Outline of   Proven and Probable Mineral Reserve, based on the 2014 FS (Ireland et al.   2014). Pretivm (2019) Notes: Source: 9-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 9-2: Plan View of 1TEM   Conductivity Data on the Western Edge of Pretivm’s Claim Block, Illustrating   the Potential Scale of the Hydrothermal System Footprint (Warmer Colours) of   which the Brucejack Deposit is a Part (also shown are Peripheral Known   Mineralized Zones on the Brucejack and Snowfield Properties and Drill Trances   From the 2015 Surface Exploration Drill Program) Source: Pretivm (2016) 9-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Underground exploration   drilling aimed at connecting the Valley of the Kings Zone to the Flow Dome   Zone and testing the porphyry potential at depth beneath the Flow Dome Zone   was conducted from the 1,200 m level in the Brucejack Gold Mine in 2018. A   total of 3,138 m was drilled in two underground exploration drillholes   (VU-820 and VU-911). Results of this drilling showed that Valley of the Kings   style mineralization and alteration was continuous from the Brucejack Gold   Mine to the Flow Dome Zone (Figure 9-3). Anomalous copper and molybdenite   mineralization coincided with a zone of relic potassic alteration between   1,400 and 1,485 m downhole depth in drillhole VU-911 and occurs more   diffusely over a broader area in drillhole VU-820 (between downhole depths   1,260 and 1,585 m). A coarse-grained porphyry intrusive was intersected and   has been dated (U-Pb zircon) at approximately 186 Ma (Board et al.   submitted), in keeping with the interpretation of a younger porphyry system   driving the Brucejack Deposit. McLeish et al. (2019) showed how zoned pyrites   changed with depth along these two drillholes: closer to the Valley of the   Kings Zone, zoned pyrites show resorbed porphyry cores overgrown with   epithermal arsenian pyrite that is then cut by electrum; epithermal zonation   diminishes with depth in the drillholes being replaced with porphyry pyrite   (with inclusions of chalcopyrite) in the vicinity of the anomalous copper and   molybdenum mineralization. Additional drilling is required to provide a   three-point problem for source porphyry vectoring. The key to intersecting   the source porphyry is to highlight the extent of the porphyry to epithermal   transition zone and its potential for additional Valley of the Kings Zone   style electrum mineralization, in addition to assessing the gold potential of   the source porphyry. Figure 9-3: Cross Section of the Brucejack Deposit   (Looking North) Showing Gold Assay Intersections from the 2015 Surface   Exploration Drilling and 2018 Underground Deep Exploration Drilling of the   Flow Dome Zone, as well as the Zone of Anomalous Copper and Molybdenite   Assays Source: Pretivm (2018) 9-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Additional ground-based   geophysical surveys were conducted as part of the 2018 Flow Dome Zone   exploration program by Frontier Geosciences Inc. A total of 8,560 m of   surface induced polarization (IP) and 6,640 m of reflection seismic ground   surveys were conducted on four lines across the Brucejack Property in 2018   (Figure 9-4). Both IP and seismic surveys were conducted on each of the three   northeast-southwest trending lines, with only IP being conducted on the   north-northwest trending linking line. A Frontier Geosciences Inc. 24-bit   full waveform time domain IP system with a GDD 3.6 kW transmitter was used   for apparent resistivity and chargeability measurements as part of the IP   survey. Electrodes were emplaced every 100 m. The reflection seismic survey   employed a Geometric Geode 24 channel signal enhancement seismograph with Oyo   Geo Space 10 Hz geophones connected at 5 m intervals in 96 phone arrays (480   m spreads) by network cables along the three survey lines (Figure 9-4).   Downhole magnetic total field, self-potential, single point resistance,   resistivity, chargeability, and gamma geophysical measurements were collected   from VU-911, the deeper drillhole drilled into the Flow Dome Zone, using a   combination of a Mount Sopris MGX II borehole logging system, a   three-component fluxgate magnetometer, and a Geonics Ltd. PROTEM transmitter   and receiver system. Downhole current injection electrodes were placed in   both drillholes to provide additional depth resolution to the 2018 IP surface   survey. Survey results were used in conjunction with other geological and   geophysical data for brownfields exploration targeting in 2019. Figure 9-4:   Plan View Part of the Brucejack Project Showing Location of the 2018 Frontier   Geosciences Inc. Surface Reflection Seismic and IP Survey Lines Source:   Pretivm (2019) 9-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 9.3 Exploration – 2019   Underground exploration drilling to further investigate the extent of the   epithermal system and potential porphyry source continued in 2019. A total of   8,810 m of drilling was completed in six underground exploration drillholes   from the 1,200 m; 1,130 m; and 1,110 m levels in the underground mine. The   results of this drilling demonstrated the continuity of gold mineralization   below the Valley of the Kings, with visible gold mineralization observed more   than 500 m below the current VOK resource (Figure 9-5). Figure 9-5: Cross   Section of the Brucejack Deposit (Looking North) Showing Gold Assay   Intersections from the 2015 Surface Exploration Drilling and 2018–2019   Underground Deep Exploration Drilling Source: Pretivm (2020) 9-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE During the initial stages of   the 2019 exploration drilling program, the focus remained on testing   exploration targets beneath the Flow Dome Zone, with drillholes VU-1785 and   VU-1787 drilled as broad step-outs (to the south and north, respectively)   from drillholes VU-820 and VU-911 from the 2018 exploration drilling   campaign. Anomalous copper mineralization was encountered in VU-1787 between   1,270 and 1,536 m, coincident with propylitic-altered volcainclastic and/or   epiclastic rocks. A zone of elevated copper mineralization was encountered at   the bottom of drillhole VU-1785 (1,850 to 2,004 m). This mineralization was   hosted in unaltered, finely laminated mudstones and siltstones of the   upper-Stuhini Formation. Pretivm considers this mineralization to be primary in   origin and not the product of porphyry-hydrothermal enrichment and is   therefore not a priority for follow-up drilling at this time. Drill core   samples at various depth intervals in the exploration drillholes (including   2018 exploration drillholes) were collected and analyzed for chlorine content   in apatite, which was observed to increase with depth down-hole (McLeish,   2019; after Williams & Cesbron, 1977 and Roegge et al., 1974). At the   same time, analysis of a suite of rock chip samples collected from stations   at various elevations within the underground mine showed that gold content in   electrum and iron content in sphalerite both increased with depth in the   underground mine (McLeish, 2019). Collectively, these geochemical trends were   interpreted as being consistent with higher temperatures approaching a   porphyry source (McLeish, 2019); furthermore, the porphyry source may be more   centrally located than previously thought, located deep beneath the Valley of   the Kings epithermal gold deposit. Drillhole VU-2019 was collared with a   steep (-84°) dip angle to test beneath and slightly north of the VOK deposit,   targeting an area where Mesozoic dykes modelled in the VOK, West Zone, and   Shore Zone appeared to coalesce at depth. Weak, anomalous copper mineralization   was observed throughout VU-2019, increasing towards the end of the drillhole   from 1,450 to 1,677 m. Patches of acicular tourmaline grains and tourmaline   veinlets, and occurrences of chalcopyrite and molybdenite, were coincident   with an interval of phyllic alteration between 1,090 to 1,320 m. A step-out   drillhole (VU-2191), drilled to the west of VU-2019, intersected similar,   weak copper mineralization over an interval from 1,175 to 1,473 m. To further   aid exploration efforts, a review of previously collected magnetotelluric   (CSMT) resistivity data was completed by Quantec Geoscience Ltd., producing a   series of 2D inversions displaying subsurface resistivity trends along   north-south and east-west oriented section lines. Section line BJ19-03   (Figure 9-6) identified a large, ‘pipe-like’, low-resistivity anomaly located   approximately 200 m north of the Valley of the Kings that extended from   surface to a depth of 1,360 m (from 1,400 to 40 m elevation). Drillhole   VU-2277, targeting the lower portion of the resistivity anomaly, intersected   an interval of strong propylitic alteration and relic potassic alteration   coincident with the northern boundary of the anomaly, from 1,200 to 1,251 m.   Drilling results showed an interval of highly anomalous copper mineralization   between 1,200 to 1,122 m, occurring within a broader interval of weak copper   mineralization from 1,150 to 1,415 m depth. To investigate the alteration and   mineralization seen in VU-2277, a new drillhole (VU-2384) was wedged from   VU-2277 at 728 m depth to test 100 m vertically below the zone of highly   anomalous copper mineralization. Drillhole VU-2384 continued into 2020 with   visual observations indicating the hole had intersected a broad interval of   strong propylitic alteration similar to that seen in VU-2277; however, final   assays had not yet been received at the time of writing. 9-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 9-6: Cross Section   (Looking West) of Quantec Geoscience Ltd. 2D CSMT Line BJ19-03 Showing   ‘Pipe-like’ Resistivity Low and Copper Assay Intersections from 2015 Surface   Exploration Drilling and 2018–2019 Underground Deep Exploration Drilling   Source: Quantec Geoscience Ltd. and Pretivm (2020) 9-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Additional ground-based IP   geophysical surveying was conducted by Frontier Geosciences Inc. in 2019, as   a follow-up to the surface geophysical survey completed in 2018. The survey   consisted of a large-scale, 3D IP survey that covered approximately 19.8 km,   over 9 separate lines. The survey was carried out using a 24-bit, full   waveform, time domain IP system powered by a pair of synchronized 5 kW GDD   Model Tx-4 5000 transmitters. Working together, this transmitter pair can   produce up to 10 kW of power. Electrode spacing was 100 m. Downhole current   injection electrodes were placed in drillholes VU-1785 and VU-2019 to provide   additional depth resolution for the 2019 IP survey. The final results and   report from Frontier Geosciences Inc. had not been received at the time of   writing; however, preliminary results for the survey are currently being used   in conjunction with other geological and geophysical data for additional   brownfields targeting of potential porphyry sources at depth near the   Brucejack Deposit. The areas of highest chargeability identified in the IP   survey are concentrated under the glacier to the south and east of the Bridge   Zone, and on the northeast side of Brucejack Lake (Figure 9-7). High   chargeability may indicate the presence of disseminated sulphides hosted   within the bedrock in these areas (Figure 9-8). Low resistivity was recorded   over much of the survey area (Figure 9-9), likely due to the presence of   hydrothermally altered rocks and clay minerals that are widespread in the   Brucejack Deposit and surrounding regions (see also Figure 9-2). Figure 9-7:   Plan View Showing Location of the 2019 Frontier Geosciences Inc. Surface IP   Survey Lines and Electrode Locations Source: Frontier Geosciences Inc. (2019)   9-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 9-8: Plan View Showing   the 17 and 50 ms Chargeability Isosurfaces from the 2019 Frontier Geoscience   Inc. IP Survey Source: Frontier Geosciences Inc. (2019) 9-12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 9-9: Plan View Showing   the 500 OHM-M Resistivity Isosurface from the 2019 Frontier Geoscience Inc.   IP Survey Source: Frontier Geosciences Inc. (2019) 9-13 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Drilling has been the primary   tool used in the exploration of the Brucejack Property (Table 10-1; Figure   10-1). Details of drilling conducted by Pretivm up to and including 2018 is   provided in Jones (2012c; 2014), Board et al. (2017) and in the April 2019   NI43-101. This section provides a summary of resource definition and   exploration drilling conducted by Pretivm in 2019; drill numbers available at   the time of resource cutoff (September 30, 2019), and therefore included in   the updated resource estimate, are provided in italics. Table 10-1: Drilling   Summary for the Brucejack Property table continues... 10-1 Year/ Program Collar   Location Hole Type & Sample Size No. of Holes Total Meters Goal and   Targets Historical 1960–1994 Surface Core (BQ, NQ, HQ) 405 52,142 West Zone,   Shore Zone, Galena Hill Zone, and Gossan Hill Zone. Underground* 442 33,750   West Zone definition, drilled proximal to the West Zone exploration ramp,   drill density of approximately 5 m centres between 5 m and 10 m spaced   sections. Silver Standard 2009–2010 Surface Core (HQ) 110 51,382 Exploration   and discovery of areas with bulk tonnage mineralization locally associated   with discreet high-grade intersections; Valley of the Kings Zone targeting   confirmed the high-grade exploration potential of the zone. Pretivm 2011–2013   Surface Core (NQ, HQ, PQ) 529 184,788 Definition of high-grade resources in   Valley of the Kings Zone, West Zone, and surrounding areas (HQ, some NQ at   depth). Zones within 150 m of surface were drilled at 12.5 m centers.   Drilling at 350 m below surface generally achieved 25 m centers, and drilling   at greater depths generally achieved 50 m centers. Water well and geotechnical   PQ drilling included 674 m in 13 drillholes. Underground Core (HQ) 409 38,840   Definition of the bulk sample area and related proximal targets. Pretivm   2014–2016 Surface Core (HQ) 41 11,919 Tested deep high-grade Inferred blocks   in the December 2013 Mineral Resource, tested depth potential of the Valley   of the Kings Zone mineralization system, and included geotechnical   (condemnation and water well) drilling. Underground Core (HQ) 368 64,022   Infill drilling to achieve a nominal 7.5 to 10 m spacing with a goal of   increasing confidence in grade estimates for the stopes to be mined in the   first three years of operation. A service drillhole linking the mine and   surface was drilled in 2016. 10.0DRILLING 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE deep exploration holes plus   one wedge hole Notes: (1)Limited surface drilling. (2)One hole ongoing at end   of 2019 and continued in 2020. Defn – Definition; Prod – Production 10-2   Year/ Program Collar Location Hole Type & Sample Size No. of Holes Total   Meters Goal and Targets Pretivm 2017–2018 Surface(1) & Underground Core   (NQ, HQ, PQ) 996 74,737 Predominantly stope infill (7.5 to 10 m center),   stope definition (4 to 7.5 m center), and resource expansion (15 to 20 m   center) HQ drilling; west-directed drilling testing north-south structures   around Brucejack Fault (18 drillholes, 5,288 m, HQ); two deep exploration   holes for porphyry targeting (3,138 m, HQNQ), 14 surface water wells (2,043   m, PQ). RC (4”) 97 (Infill) 74 (Defn) 178 (Prod) 5,049 1,736 2,461 Testing of   reverse circulation method and definition and infill of stopes; nominal 7.5   to 10 m spacing (infill); 4 to 7.5 m spacing (definition), and 2 m spacing   (production). Pretivm 2019 Surface(1) & Underground Core (NQ, HQ) 752   (555 assayed) 124,609 (89,121 m assayed) Predominantly underground resource   expansion (15 to 30 m centers) HQ drilling; five for porphyry targeting   (8,810 m, HQNQ)(2), and 18 surface resource expansion holes (2,298 m, HQ).   555 holes (89,121 m) had assays available at resource cutoff date. RC (4”)   1423 23,552 “Production holes” intended for use as grade control and blast   holes to build data set for future grade control methodologies. All RC production   holes and samples were excluded from the resource data export and were not   included in the updated resource. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 10-1: Plan View of   Brucejack Property Drilling In and Around the Brucejack Deposit 1 D r F, Area   D20 13 Rt:::.W F'--·"'t!6 {J\.1112014) D a one Resou--ce Area (Jones NAD   1983 UTM Zone 9N Newhawk 0'"1lTraces 427000 428000 Source: Pretivm   (2020) ['n;ITETRA TECH 10-3 PRETIVM Ill CJ MP il (W1atArf!a0 PretJVm Dtil   2019 PrtlVm l'l'ilTr;:r.P.S (701) Pretlvm OriiTraces (pre-2019) fAivcr   S:a'ldard DnllTraces 0250500 Meters r'01_0J 3250_0nlll-lole_2019_65J   11_20200·23 24 Jan 2020 ; 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 10.1 Pretivm Drilling (2019)   Drilling Activities Underground diamond drilling conducted on the Brucejack   Property in 2019 included exploration (deep drilling) and resource expansion   (15 to 30 m centers) fan drilling in the Valley of the Kings Zone (Figure   10-1). The majority of 2019 drilling was underground HQ diamond core aimed at   increasing confidence and resolution to the mineral resource (Table 10-1).   Underground resource drilling included 113,507 m in 727 underground diamond   drillholes; 555 of these holes had results available at the time of resource   cutoff for a total of 81,060 m. Surface HQ diamond core resource expansion   drilling totaled 2,298 m in 18 drillholes; two holes had assay data for a   total of 239 m of assayed core at the time of resource cutoff. Underground   deep exploration drilling totaled 8,810 m in six drillholes, one of which was   a wedge hole. Assay data for four of these holes were available at the time   of resource cutoff, corresponding to a total of 6,025 m. These deep   exploration drillholes were drilled towards the east, southeast, and north to   test the depth extension potential of the Valley of the Kings Zone mineralization,   porphyry mineralization at depth, and the potential source of the Valley of   the Kings mineralization (see Section 9.0). Drilling Contractors and   Equipment Hy-Tech Drilling Limited (Hy-Tech), based out of Smithers, BC, has   been the primary drilling contractor on the Brucejack Project since 2013.   Hy-Tech’s TECH B5000 diamond core drill rigs have been used for all surface   and underground exploration and resource expansion drilling on the Brucejack   Property. In 2019, Hy-Tech tested a modified TECH B5000 underground diamond   core rig on a smaller feed frame to improve mobility between drill sites as   part of the underground resource definition drilling program. Testing showed   that there was minimal improvement in mobility and reduced drill production   with the modified drill, so it was removed from site. Drill Coordinates and   Downhole Surveys Drillhole survey procedures in 2019 were similar to previous   years (e.g., Jones 2014). Diamond drillhole collar locations were surveyed   and marked up by Pretivm’s mine survey team prior to drilling, and   re-surveyed post-drilling. All collar surveys were obtained using a total   station theodolite in conjunction with a regular array of permanent ground   control stations. Collar azimuth and dip information was recorded for each diamond   core drillhole using a Reflex TN-14 Gyro instrument operated by the drill   contractor. Downhole dip and azimuth data were measured for diamond core   drillholes by the drill contractor using primarily a Reflex EZ single shot   instrument at nominal 25 to 50 m intervals. A Reflex EZ Gyro was used to   complete downhole surveys for most of the deep exploration holes. Drillhole   survey data were collected, entered into the GeoSpark logging interface, and   processed by Pretivm’s mine geologists. The data were verified and imported   in the GeoSpark back-end geological database by Pretivm’s database manager.   Additional 3D checks were conducted in the Maptek Vulcan mining software:   collar locations were checked in relation to surveyed topography and   underground mine development solids, and downhole survey traces were checked   for wayward deviations. 10-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Diamond Drill Core Logging   Procedures Core logging procedures previously established for the Brucejack   Property (Jones 2014) were followed during the 2019 drilling. Details on core   handling and sampling are presented in Section 11.0. Core logging is   conducted in well-lit core shacks on appropriately labelled core boxes.   Exploration and resource expansion drill core was geotechnically (recovery,   rock quality designation (RQD), faults, fractures, joints, etc.) and   geologically (lithology, structure, veining, alteration, and mineralization)   logged prior to being marked up for sampling and photographed. Core logging   information was recorded in the GeoSpark core logging software, which   includes data validation, picklists, and minimum required fields to ensure   data capture is consistent and valid. Additional data validation is conducted   by Pretivm’s database manager prior to importing core logging data into the   Structured Query Language (SQL) GeoSpark database. These include collar,   survey, and interval (missing/overlapping geological and sampling intervals)   checks and actual to planned cross-referencing. Summary of Results The   resource expansion drilling (15 to 30 m spacing) conducted during 2019 was   designed to expand and upgrade the Valley of the Kings resource in the   southern, western, and northwestern portions of the deposit. Drilling was   completed in two phases with phase one being drilled from the 1,170 m; 1,140   m; and 1,110 m levels, and phase two was drilled from the western end of the   1,320 m level. Phase two was still ongoing at the writing of this report.   Phase one drilling was primarily completed towards the southwest, targeting   an area between the 1050 and 1200 levels across the Valley of the Kings Zone.   Phase two drilling targeted a large area between the western extents of the   Valley of the Kings development and the Brucejack Fault between the 1200 and   1380 m levels. A surface resource drilling program commenced in the fall of   2019 to increase confidence in mineralized domains in the upper levels of the   Valley of the Kings Zone. The resource fan drilling conducted during 2019 was   designed to increase the drill density within the Brucejack resource and to   test mineralized domains to depth in the south, the west, and northwest of   the Valley of the Kings Zone. The drilling confirmed the geological   interpretation of continuous, dominantly east-southeast-west-northwest   trending structural vein and vein stockwork corridors containing ubiquitous,   yet highly variable and erratically distributed gold and silver   mineralization in the Valley of the Kings Zone (Figure 10-2 and Figure 10-3).   The deep exploration drillholes drilled in 2019 were successful in   demonstrating the presence of Valley-of-the-Kings-Zone-style mineralization   at depth. They were also successful in intersecting porphyry-style alteration   and mineralization at depth (see Section 9.2). 10-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 10-2: Plan View on the   1,140 m Level in the Brucejack Gold Mine Showing 2019 Drilling and Valley of   the Kings Zone Mineralized Domain Interpretations (Viewing Window ±20 m)   Note: Source: Disks are expanded to form intervals of gold intersections   greater than 2.5 g/t. Pretivm (2020) 10-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 10-3: Example SW-NE   Cross Section Along Mining Crosscut 17 (Central Parts of the Mine) Showing   Workings, Drilling, and Mineralized Domain Interpretations in the Valley of   the Kings Zone of the Brucejack Deposit (Viewing Window ±20 m) Note: Source:   Disks are expanded to form intervals of gold intersections greater than 2.5   g/t. Pretivm (2020) 10.2 Opinion of Qualified Person The QP is of the opinion   that the drilling, core logging, and sample handling procedures have been conducted   using industry best practices. The appropriate level and quality of   information has been obtained to provide sufficient confidence in drillhole   spatial location for three-dimensional geological, geotechnical, and grade   modelling of the Brucejack Deposit. There are no apparent drilling or   recovery factors that would materially impact the accuracy and reliability of   the drilling results. 10-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Sample preparation, analysis,   and security for the years 2014 to 2018 inclusive are summarized in this   section. For detailed sample preparation and analysis information prior to   2014, the reader is referred to Jones (2014) and Ireland et al. (2014). 11.1   Sample Preparation, Analysis, and Security 11.1.1 Drillhole Sampling The   majority of the samples collected between 2014 and 2019 were from HQ diameter   diamond drillcore. Drillcore was placed in core boxes at the drill rig (both   on surface and underground), with drill footage markers recorded on wooden   spacers and drillhole numbers and box numbers recorded on each box. Batches   of core boxes were sealed and transported to Pretivm’s core logging and   processing facilities on site under the control of geological staff. Core was   then geologically and geotechnically logged and photographed prior to being   sampled. Sample intervals were delineated by the core logging geologist,   taking geology into account. Samples were generally broken at key   lithological and stockwork zone contacts. Samples were collected at intervals   of 1 to 1.5 m in length for surface and underground exploration drillholes,   as well as for underground resource definition and infill drillholes. Up to   the end of 2017, significant intervals of visible gold were sampled down to a   minimum length of 0.5 m. All exploration drillholes testing poorly drilled or   undrilled areas were marked for half core sampling with a centerline drawn   down the core axis by the core logging geologist. All resource definition   and/or infill drillholes were whole core sampled. Each of the diamond   drillholes from the programs between 2017 and 2019 was sampled in its   entirety. Whole core sampling was conducted in an effort to eliminate any   sampling bias potentially associated with preferential half core selection as   a function of visible electrum occurrences, as well as to ensure that any   electrum in a given length of core would have a chance of being sampled.   Sampled drillcore was placed in numbered plastic bags with appropriate sample   tags. Sealed sample bags were then grouped and sealed in appropriately   labelled rice sacks and sent by ground transportation to the ALS sample   preparation facility in Terrace, BC. Hard copies of sample manifests were enclosed   with each shipment and also e-mailed directly to the sample preparation   facility ahead of shipping. Ground sample preparation was either by an   independent operator (Bandstra Transportation Systems or Tsetsaut Ventures   Ltd.) or by a Pretivm operated vehicle depending on quantity of samples being   shipped. RC samples were collected as part of the underground RC drillhole   trial conducted in early 2018. Two, 2 kg dry RC sample splits were collected   from a cyclone splitter directly into pre-labelled plastic sample bags every   1.52 m. Bags of single sample splits were grouped into four samples per rice   bag. Rice bags were then collected in apple crates, sealed with a lid, and   then shipped to the ALS sample preparation facility in Terrace, BC in the   same way as for the drillcore (see above). Sampling and shipment creation   procedures were conducted by Pretivm personnel prior to dispatch off site to   the ALS sample preparation facility in Terrace, BC. ALS checked all samples   against the electronic and hard copy sample manifest and assumed custody of   the sealed samples upon receipt. 11-1 11.0SAMPLE PREPARATION, ANALYSES, AND   SECURITY 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 11.1.2 Sample Preparation and   Analysis by Analytical Laboratory ALS Vancouver has been the primary   analytical laboratory for the analysis of samples from the Brucejack Property   since 2009. Umpire check analytical laboratories used include MSALabs and   Met-Solve. The ALS laboratory is used to provide umpire checks on the quality   of production sample assays conducted at the on-site laboratory. The ALS   analytical laboratory in Vancouver is an International Organization for   Standardization (ISO) 9001-2015 certified and ISO 17025:2005 United Kingdom   Accreditation Service (UKAS) ref. 4028 accredited laboratory. MSALabs has   both ISO 17025 and ISO 9001 accreditation. These laboratories are all   independent of Pretivm. Primary sample preparation methods and analytical   packages used for Pretivm drill samples from 2014–2019 are summarized in   Table 11-1. After sample shipments reach the sample preparation facility,   they are in ALSs custody for sample preparation, inter-laboratory shipping,   and analyses. It is ALSs standard operating procedure to check all samples   received from Pretivm against the electronic and hard copy sample manifests,   as well as for any potentially missing sample material, compromised plastic   sample bags, broken zip closures, or torn/broken rice bags upon receipt.   Pretivm has not been alerted to any potential sample tampering by ALS.   Laboratory sample reduction and analytical procedures have been conducted by   independent accredited companies using industry standard methods. Pretivm   ensured quality control was monitored through the frequent insertion of   blanks, certified reference materials, and duplicates. 11.1.3 Specific   Gravity and Bulk Density Density determinations to support the resource model   were carried out prior to 2014 as described in Jones (2014). In 2019, Pretivm   obtained 816 new pulp specific gravity (SG) measurements and 139   corresponding core SG and bulk density (BD) measurements from key lithologies   and drill locations to update the SG interpretation. 717 SG and 133 BD   measurements were available at the resource cutoff date. The new data were   reported by ALS minerals using the same laboratory methodology used prior to   2014. Comparison between the pulp SG and core density measurements indicated   that the core density is on average the same as the pulp SG within the   siliceous zone. Bulk density estimates have been reasonable predictors of   tonnage for production. Additional SG and bulk density measurements will be   needed as the resource model is expanded in areas away from the current   workings to reflect the change in lithology at depth, across, and along   strike from the known mineralized zones. 11-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 11-1: Sample   Preparation and Analytical Methods Conducted on Pretivm Drill Samples Between   2014 and 2018 finish (AG-OG62) Notes: ALS method codes shown in parentheses.   SFA – Screen Fire Analysis; AA – Atomic Absorption; VG – Visible Gold; ICP –   Inductively Coupled Plasma; AES – Atomic Emission Spectroscopy; AAS – Atomic   Absorption Spectroscopy 11-3 Year Sample Preparation Gold Analytical Methods   Multi-element Methods (incl. Ag and Overlimits) 2014-2018 (Q1) Diamond Drill   Core Samples 1.Crush entire sample to 70% <2 mm 2.Riffle split 3.Pulverize   500 g to 85% <75 μm 30 g charge weight fire assay by AA finish to upper   limit at 10 ppm (Au-AA23) Au overlimit trigger at 10 ppm to complete 30 g   fire assay with gravimetric finish (Au-GRA21) Au overlimit trigger at 10,000   ppm to complete high precision analysis by fire assay with gravimetric finish   (Au-CON01) Visible Gold (VG) Samples: Au by screen fire assay for VG-bearing   samples (Au-SCR21, using 30 g charge weights) 33 element package (including   Ag) using a four-acid near-total digestion and an ICP-AES analysis   (ME-ICP61). Ag overlimit trigger at 100 ppm Ag for three-acid digestion with   HCL leach and ICP-AES or AAS Ag overlimit trigger at 1,500 ppm Ag by 30 g   fire assay with gravimetric finish (Ag-GRA21) Overlimit triggers also for Zn,   Pb, Cu by their respective OG62 methods (Zn-OG62, Pb-OG62, Cu-OG62) 2018 (Q2)   1.Crush entire sample to 70% <2 mm Diamond Drill Core Samples 2.Riffle   split to 1x1 kg pulp for SFA 3.Pulverize to 85% passing 75 μm Resource RC   Drill Samples 2.Riffle split into two, 2 kg splits 3.Pulverize 2 kg to 85%   <75 μm 4.Riffle split pulp in half for analysis Whole Core and Resource RC   Drill Samples Au total parts per million by screen fire assay for all samples   (Au-SCR24, 50 g charge weights) RC Samples Only Au parts per million by   Leachwell head/tails (Au-AA15) Diamond Drill Core Samples: unchanged from   2014 Multielement data not collected for RC drill samples 2018 (Q3) onwards   Diamond Drill Core Samples 1.Crush entire sample to 70% <2 mm 2.Riffle   split 3.Pulverize 2 kg to 85% <75 μm Production RC Samples 1.Crush entire   sample to 70% <2 mm 2.Riffle split 500 g 3.Pulverize to 85% <75 μm   Diamond Drill Core Samples Au parts per million by 50 g fire assay with AA   finish to 18 ppm (Au-AA26; upper limit 100 ppm) Requested trigger for Au   overlimit at 18 ppm for completion of 50 g fire assay by gravimetric finish   (Au-GRA22) Au overlimit trigger at 10,000 ppm to complete high precision   analysis by fire assay with gravimetric finish (Au-CON01) Production RC   Samples Au by fire assay with AA finish (20 to 30 g charge) with upper limit   of 10 ppm Au overlimit trigger for >10 ppm by fire assay with gravimetric   finish Diamond Drill Core Samples: unchanged from 2014 Multielement data not   collected for production samples 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 11.2 Quality Assurance and   Quality Control Pretivm’s QA/QC protocols for the Brucejack Property included   tests for data accuracy, precision, and sample cross-contamination. Field   control samples were submitted together with drillhole samples to control and   assess these key indicators of database quality. Accuracy, a measure of the   closeness to the true value, was tested using matrix-matched round-robin   certified standard samples (certified by Smee and Associates Consulting   Ltd.). Analytical precision (repeatability of results) was checked using   duplicate samples. Potential cross-contamination between samples as a result   of smearing of high-grade samples was checked through the use of coarse blank   samples. Field control samples were inserted into the sample stream at a   frequency of 1 standard, and 1 blank sample and a minimum of 1 coarse reject   or pulp duplicate sample per 20 regular samples. Additional field control   blank samples were inserted immediately following samples with logged visible   gold to quantify and avoid any potential cross-contamination between samples   as a result of smearing from high-grade samples. Quarter core samples served   as field duplicate control samples for exploration drillholes prior to 2014.   Coarse reject duplicate samples have been used as field control duplicate   samples to assess precision for whole core resource definition and infill   drillholes from 2014 through to the present (2019). Coarse rejects were also   used as field control duplicates for resource RC drilling. Secondary   laboratory duplicate assays were conducted on approximately 5% of the   mineralized ALS pulps at the Met-Solve (2014–2015) and MS Analytical   laboratories (2016–2019) using comparable analytical methods. From 2011–2016,   GeoSpark Consulting, a Nanaimo, BC based geological database software and   services company that is independent of Pretivm, managed the Brucejack assay   imports and completed assay QA/QC for the database. From 2017 to present,   assay data has been imported into the same database and managed by Pretivm;   however, GeoSpark was retained in 2017 and 2018 to independently conduct   routine QA/QC checks on Pretivm’s database and compile QA/QC reporting   through its GeoSpark Assure Quality Service program. QA/QC reporting for the   2019 program was completed in-house using the Geospark QAQC module. Real-time   QA/QC review of Pretivm’s drillhole sample data includes sample reruns where   field control standard results warrant further investigation. Pretivm’s   drilling and sampling database has been collected, imported, stored, and   managed using GeoSpark’s GeoSpark Core Database System software since 2011.   Numerous QA/QC reports have been written verifying the quality of Pretivm’s   assay data and its applicability for use in resource estimation. QA/QC   results from the 2011 through 2013 program are summarized in Jones (2014),   Graindorge and Carlson (2014), and Vallat (2011; 2012; 2013; 2014). QA/QC   results from the 2014 through 2016 programs are summarized in Board et al.   (2017), Mooney (2015), and Vallat (2015; 2016a; b). QA/QC results from the   2017 and 2018 drilling programs are summarized in Vallat (2018; 2019). QA/QC   for the 2019 drill program is provided in Madsen (2019). Results of the QA/QC   analyses indicate acceptable levels of accuracy and precision across all of   Pretivm’s drill programs on the Brucejack Property considering the nuggety   nature of the precious metal mineralization. The main conclusions are:  Errant values on field standard control   charts are minimal and usually reflective of mislabeled standards or blanks,   or are considered as acceptable in unmineralized intervals.  Duplicate assay analysis of field control   samples indicates an improved degree of precision between field duplicate   quarter core and coarse reject duplicate samples, for both gold and silver.   Half absolute relative difference (HARD) statistics show that: - 90% of   all quarter core field duplicates collected between 2009 and 2015 reported at   a precision of better than 30% for gold and 25% for silver, whereas 11-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 90% of all coarse reject   samples collected from whole core sampling between 2013 and 2018 reported at   a precision of better than 14% for gold and 11% for silver (16.2% for gold   and 14.8% for silver for the 2019 coarse reject subset). - Coarse   reject duplicate samples are at the same sample support (mass) as the   original field sample and are therefore better than quarter core duplicate   samples for representatively assessing precision at the field duplicate   level, especially given the nuggety nature of Brucejack Deposit   mineralization. - The HARD statistic demonstrated that 90% of all pulp   duplicate analyses conducted by ALS during 2019 and reported at a precision   of better than 9.7% for gold and 12.5% for silver comparable to previous   years. This level of precision in pulp duplicate samples is expected, given   the nature of precious metal mineralization in the Brucejack Deposit.  Overall, sample cross-contamination during   sample preparation and assaying is considered to be within acceptable   tolerance intervals.  Umpire pulp check   assays for gold show a good comparison between analytical laboratories with an   acceptable level of precision being achieved.    Gold and silver assay data used as input for resource modelling of the   Brucejack Deposit should be considered as having a variance of ±15%, 9 times   out of 10.  11.3 Qualified Person’s   Opinion on Sample Preparation, Security, and Analytical Procedures It is the   QP’s opinion that the sample preparation, sample security, and analytical   procedures are satisfactory and appropriate for generating data of suitable   quality for use in resource modelling and estimation of the Brucejack   Deposit. 11-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Details on data verification   conducted prior to 2014 is presented in previous technical reports on the   Brucejack Property (Ghaffari et al. 2010a; 2010b; 2011; Jones 2012a; b; c;   2014; Ireland et al. 2013; 2014). 12.1 Data Verification by Qualified Person   Continued verification of geological information and data used for mineral   exploration and resource estimation on the Brucejack Property has been   conducted by Mr. I.W.O. Jones, P.Geo., FAusIMM, Pretivm’s independent QP for   resource estimation. Mr. Jones has been involved with the evaluation of the   Brucejack Deposit since 2011 and has conducted numerous site visits (refer to   Section 2.0) to the Brucejack Property through the various exploration   drilling, resource definition drilling, bulk sample extraction, mine   development, and production stages between 2011 and 2019. During his mine   visits, Mr. Jones reviewed sufficient surface, drill core, and underground   exposures to confirm the presence and nature of the mineralization and   appropriateness of the interpreted geological framework. Mr. Jones has   verified Pretivm’s drilling, sample preparation, handling, security, and chain   of custody procedures on site, as well as surface and underground drillhole   locations, core handling, and core logging. He has also reviewed Pretivm’s   database integrity and data quality for use in resource estimation (see   Section 11.0). Mr. Jones has reviewed and been involved in all stages of the   geological modelling and domain definition for the Brucejack Deposit between   2011 and present and has assessed the applicability and robustness of these   interpretations in the underground mine workings at the Brucejack Gold Mine.   Mr. Jones visited the Contact Mill in Philipsburg, Montana, during the 2013   Bulk Sample Program and has visited the Brucejack Gold Mine mill on multiple   occasions, both to understand the nature of coarse-versus fine-gold   mineralization as part of resource estimation process improvement, and to   improve approaches to reconciliation. Mr. Jones has observed abundant visible   electrum intersections in drill core as well as in underground workings,   verifying the presence, nature, and deportment of gold mineralization in the   Brucejack Deposit. Mr. Jones developed and has continually assessed the   appropriateness of the technique used for estimation of the Mineral Resource   for the Brucejack Deposit through his ongoing working relationship with Pretivm.   Mr. Jones did not deem it necessary to collect and analyze additional   independent drill core samples between 2014 and 2019 for the following   reasons: A total of 5,923 oz of gold was produced from the 10,302 t bulk   sample in 2013 (Ireland et al. 2014).    Mr. Jones has inspected abundant visible gold showings in underground   workings.  The Brucejack Gold Mine is   in production: 882,091 oz of gold was produced by the end of 2019.  12.2 Qualified Person’s Opinion of the   Verification Sufficient checks have been completed to satisfy Mr. Jones that   the Brucejack Gold Mine drilling and sampling data and geological   interpretations are of suitable quality and robustness for resource modelling   and estimation. 12-1 12.0DATA VERIFICATION 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Metallurgical testing   programs have been conducted on the Brucejack Property since 1988, with major   work performed between 2009 and 2014, to investigate the amenability of   mineralization of the Valley of the Kings Zone and West Zone to conventional   separation processes for gold and silver recovery. A 2,700 t/d process plant   was designed based on these test results. The test work review and process   design descriptions were filed in 2014 FS (Ireland et al. 2014). Between   March and May of 2017, the Brucejack Gold Mine was successfully commissioned   with the first gold pour on June 20, 2017. The plant reached full operation   in Q3 2017. The average production rate reached 2,950 t/d during Q4 2017,   which is higher than the design capacity. Plant throughput has been tested   for 3,800 t/d. To optimize process conditions and increase the process plant   throughput to reach the target capacity of 3,800 t/d, Pretivm conducted a   comprehensive process and metallurgical review, including new flotation and   gravity tests and grinding circuit simulations and operation test trials.   This section provides a summary of previous test work, including bench scale   tests and bulk sample tests, plant production data since the beginning of   full operation, and new test work to support plant expansion and improve   metallurgical performance. 13.1 Previous Bench-Scale Test Work The main   testing programs on the Brucejack Property were conducted between 1988 to   2014 and were noted in Ireland et al. (2014). Test work conducted between   1988 and 1990 investigated the mineralization’s amenability to gravity   concentration, flotation concentrate cyanidation, as well as gravity   concentration plus whole ore cyanidation. Samples collected from the West   Zone and the R-8 Zone were used for this test work and the results indicated   that gravity separation would recover a significant portion of the contained   gold. Cyanide leaching on the gravity tailings produced good overall gold   recoveries, but poor silver recoveries. The samples appeared to respond well   to flotation concentration; however, results showed that the R-8   mineralization might require finer primary grinding. Test work conducted between   2009 and 2014 established the design basis for the 2014 FS (Ireland et al.   2014), which investigated head sample characteristics; varied processing   methods, including gravity concentration, gold/silver bulk flotation, and   cyanidation; and melting and SLS tests. The tested samples were obtained from   the Valley of the Kings Zone, the West Zone, and from adjacent gold deposits   such as the Galena Hill (GH) Zone and the Gossan Hill (R-8) Zone. Ireland et   al. (2014) design work focused on the Valley of the Kings Zone and the West   Zone. 13.1.1 Sample Description and Characteristics The 2009-2014 test   programs utilized core samples and their composites, along with assay reject   material. The head assays showed a large variation of gold content from less   than 1 g/t to over 70 g/t. The occurrence of nugget gold was identified using   parallelized gold assay tests, by comparing the conventional fire assay and   screen metallic assay methods. 13.1.1.1 Mineralogy Analysis Process   Mineralogical Consulting Ltd. (PMCL), in 2012, and Inspectorate Exploration   and Mining Services Ltd. (Inspectorate), in 2014, conducted mineralogical   analysis work on head samples. The PMCL work indicated that electrum was the   primary gold bearing mineral in the tested samples. Fine gold grains, from 2   to 32 μm in size, 13-1 13.0MINERAL PROCESSING AND METALLURGICAL TESTING 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE were reported and occurred as   fracture fillings in pyrite and as disseminated grains and inclusions to   gangue minerals and pyrite. Carbonate mineral content was approximately 2 to   3%. Major silver-bearing minerals included electrum, polybasite, acanthite,   and selenopolybasite. Most silver-bearing minerals presented as liberated   grains with a lesser amount associated with pyrite and gangue minerals. The   work completed by Inspectorate showed that the observed gold grains were all   finer than 5 μm in circular diameter and mostly liberated. The unliberated   gold was associated with pyrite. At a primary grind size of 80% passing 87 m,   90% of the pyrite was liberated. 13.1.1.2 Comminution Studies Gekko Systems   Pty Ltd. (Gekko) conducted vertical shaft impactor (VSI) crushing test, which   resulted in a positive conclusion that the samples are amenable to VSI   crushing. The specific gravity measured from the samples were in the range of   2.71 to 2.87. Inspectorate and Hazen Research Inc. (Hazen) performed   grindability tests during various test programs and, in general, the   mineralization appears to be moderately hard. Table 13-1 shows the Bond ball   mill work index (BWi) results, which were observed between 13.8 and 17.2   kWh/t, and Table 13-2 show the SAG mill comminution (SMC) test results. Table   13-1: Conventional Grindability and Crushability Test Results table   continues... 13-2 Sample ID BWi (kWh/t) Cut Particle Size (μm) RWi (kWh/t) CWi   (kWh/t) UCS (psi) Ai (g) Inspectorate (2013) MU (Upper Zone Master Composite)   15.6 106 - - - - ML (Lower Zone Master Composite) 15.0 106 - - - - Hazen   (2012) VOK HW 1 14.2 149 14.4 12.3 20,910 0.2254 VOK Ore 1 14.4 149 15.6 11.4   15,680 0.2125 VOK Ore 2 14.4 149 14.6 11.1 8,510 0.1384 VOK Ore 3 15.4 149   17.9 10.4 9,000 0.0903 VOK Ore 4 14.2 149 15.2 9.3 11,800 0.3820 VOK Ore 5 13.8   149 14.3 7.9 5,770 0.2474 VOK Ore 6 14.4 149 13.5 8.9 11,500 0.2385 WZ HW 1   12.2 149 13.2 6.9 2,520 0.0388 WZ Ore 1 16.7 149 16.7 11.8 22,390 0.3069 WZ   Ore 2 15.3 149 15.1 10.7 15,530 0.3535 WZ Ore 3 15.8 149 15.5 10.3 20,310   0.6599 WZ Ore 4 15.5 149 17.0 9.5 26,460 0.2479 Inspectorate (2012) VOK-1   Master Composite 15.8 74 - - - - VOK-2 Master Composite 15.3 74 - - - - VOK-3   Master Composite 15.8 74 - - - - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Note: RWi – Bond rod mill work index; CWi –   Bond crushing work index; UCS – universal compressive strength; Ai – Bond   abrasion index; BZ – Bridge Zone; Cut Particle Size – screen aperture Table   13-2: SMC Test Results (2012) DWi – Drop weight index; Mia = coarse ore work   index provided directly by SMC Test®; Mih – high-pressure grinding roll   (HPGR) ore work index provided directly by SMC Test®; Mic – crushing work   index provided directly by SMC Test®; ta – low-energy abrasion component of   breakage; HW – hanging wall Note: 13.1.2 Gold and Silver Recovery Tests –   Gravity Concentration Two-stage gravity separation programs (2009/2010,   2012/2013), including centrifugal and panning concentration, were carried out   on head composite samples, head variability samples, and flotation   concentrate samples. The results indicated that most of samples responded   well to the tested gravity separation methods. Reground concentrate samples   presented better performance compared with their head samples. The reported   gold gravity recovery ranged between 2.7 to 56.0%, and silver recovery varied   between 1.0 to 44.0% for composite head samples. The average metal recovery   of variability head samples was 45.8% for gold and 21.4% for silver; the   average metal recovery of the flotation concentrates produced from 11   variable samples was 24.5% for gold and 11.6% for silver. In 2012, FLSmidth   Knelson (Knelson) and Met-Solve conducted gravity recoverable gold (GRG)   tests and related simulations. Table 13-3 shows the test results and Figure   13-1 shows the GRG versus grind size. 13-3 Sample ID DWi (kWh/m3) A b Axb Mia   (kWh/t) Mih (kWh/t) Mic (kWh/t) ta Specific Gravity VOK HW 1 5.76 52.8 0.92   48.6 16.7 12.0 6.2 0.45 2.79 VOK Ore 1 6.37 56.6 0.77 43.6 18.1 13.2 6.8 0.41   2.79 VOK Ore 3 7.12 62.9 0.62 39.0 20.2 15.0 7.8 0.40 2.75 VOK Ore 5 4.61   52.3 1.16 60.7 13.9 9.5 4.9 0.56 2.81 WZ HW 1 4.89 55.2 1.08 59.6 14.1 9.8   5.1 0.53 2.90 WZ Ore 2 7.08 66.7 0.59 39.4 19.9 14.8 7.7 0.37 2.76 WZ Ore 4   6.32 69.9 0.62 43.3 18.3 13.3 6.9 0.41 2.75 Average 6.02 59.5 0.82 47.7 17.3   12.5 6.5 0.44 2.79 Average – VOK 5.97 56.2 0.87 48.0 17.2 12.4 6.4 0.45 2.79   Average – WZ 6.10 63.9 0.76 47.4 17.4 12.6 6.6 0.44 2.80 Sample ID BWi   (kWh/t) Cut Particle Size (μm) RWi (kWh/t) CWi (kWh/t) UCS (psi) Ai (g) VOK-4   Master Composite 15.7 74 - - - - WZ-1 Master Composite 17.2 74 - - - - WZ-2   Master Composite 15.7 74 - - - - Inspectorate (2009 to 2010) BZ Composite   16.4 105 - - - - GH Composite 15.6 105 - - - - R-8 Composite 16.2 105 - - - -   

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 13-1: Cumulative Stage   GRG versus Grind Size for Gold and Silver Table 13-3: Gravity Recoverable Gold   Test Results (2012) Note: E-GRG – extended gravity recoverable gold In 2014,   FLSmidth Dawson Metallurgical (FLS-DM) conducted tabling tests on gravity   concentrates samples (Table 13-4). Further, Gekko tested the amenability of   the samples to in line pressure jigging technology. The results indicated   that when the mass pull was reduced to 5%, the gold recovery ranged from 43   to 67%. Table 13-4: Precious Metal Material Balance (2014) 13-4 Product   Weight (g) Assay (g/t) Distribution (%) Au Ag Au Ag Table Concentrate 60.4   199,935 107,297 23.0 21.1 Table Middlings 1 250.7 40,571 24,715 19.3 20.2   Table Middlings 2 2,655.2 9,058 5,290 45.7 45.8 Table Tailings 6,308.6 1,000   629 12.0 12.9 Calculated Head 9,274.9 5,672 3,309 100.0 100.0 Lab Tests   Primary Grind/ Regrind Size Sample Head Grade (g/t) GRG Recovery (%) Cyanide   Leaching Recovery (%) Gravity Upgrading Tabling Recovery (%) Au Ag Au Ag Au   Ag Au Ag Knelson E-GRG P80 74 μm 17.0 58.6 80.3 9.1 99.5 86.9 n/a n/a   Met-Solve GRG TBD 18.7 63.0 80.7 33.7 99.2 92.2 61.1 42.5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.1.3 Gold and Silver   Recovery Tests – Flotation Concentration Inspectorate conducted a preliminary   test program between 2009 and 2011 and further optimization tests from 2011   to 2013, which included bulk flotation tests and cleaner flotation tests on   samples from the Valley of the Kings Zone, the West Zone, and adjacent gold   deposits. Met-Solve tested slime material response to flotation in 2014.   13.1.3.1 Bulk Flotation The bulk flotation tests were conducted to   investigate the effects of primary grind size, reagent types, and pH levels.   The primary grind size of 80% passing a range of 38 to 143 μm was tested on   different mineralization samples. The overall gold recovery from gravity   concentration and bulk flotation was found to increase with a finer primary   grind size; however, for most samples, the gold recovery increase become   insignificant when the primary grind size was finer than 74 μm. The reagent   schedule and pH level were found to have an insignificant effect on gold   flotation recovery. 13.1.3.2 Cleaner Flotation The cleaner flotation tests   were carried out on rougher and scavenger concentrates. The results indicated   that the upgrading efficiencies were good for both gold and silver. The gold   upgrading efficiency, which was better than silver, still varied   significantly in the tests. Attempts to solve this problem were tested by   introducing a regrinding circuit prior to the cleaner flotation stage,   adjusting flotation pH level, applying different collectors, and/or adding   sulphide depressants but were met with little success. 13.1.3.3 Other   Flotation Met-Solve conducted a preliminary flotation test to recover gold   from the fine fraction generated in a de-sliming classifier. Significant gold   was able to be recovered, but a low flotation pulp density, as well as a high   dosage of sodium silicate (dispersant reagent) were required to control the   viscosity of the slurry. 13.1.4 Gold and Silver Recovery Tests – Cyanidation   Between 2009 and 2013, Inspectorate conducted cyanidation tests on head   samples of composite and individual mineralization, flotation concentrates,   and gravity concentrates. A significantly varied gold recovery range was reported   in direct cyanide leaching tests. Improved gold recoveries were generated   when using a combined method of gravity + leaching flotation concentrates or   gravity + leaching gravity tailings. Inspectorate conducted flowsheet   development tests to incorporate these observations. The following three   flowsheets were examined: Flowsheet A: Primary grind, gravity concentration,   rougher/scavenger flotation, and cyanidation on the reground flotation   concentrates.  Flowsheet B: Primary   grind, rougher/scavenger flotation, and a gravity separation on the reground   concentrates prior to cyanidation on the gravity tailings.  Flowsheet C: Primary grind, primary gravity   concentration, rougher/scavenger flotation, a secondary gravity separation on   the reground concentrates prior to cyanidation on the gravity tailings, and   intensive leaching on the panning tailings.    13-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 13-5 summarized the   overall gold recoveries of the three flowsheets. Table 13-5: Cyanidation   Flowsheet Development Test Results 13.1.5 Variability Tests In 2012,   variability tests based on primary gravity concentration and bulk flotation   were conducted with varied core samples. In general, the overall metal   recoveries were consistent with the results from the composite samples. Gold   recovery varied from 82.8 to 99.8%, averaging 97.2%, while the head gold   grade fluctuated from 0.5 to 200 g/t, averaging 21.5 g/t. At a silver head   grade range of 3.9 to 1,897 g/t, the silver recovery varied from 51.2 to   99.1%, averaging 88.5%. In 2011, variability tests based on Flowsheet C were   performed, which indicated there was no significant variation in   metallurgical performance between the West Zone and the Galena Hill Zone   mineralization. The overall average gold recovery was 94.5%, which was   approximately 19% higher than the average silver recovery. The regrind size   was finer than 80% passing 10 m. The variability tests based on Flowsheet B   showed a significant variation of the overall gold recoveries, while the   overall silver recovery fluctuation was moderate. 13-6 Samples Gravity   Recovery (%) Leaching Recovery (%) Overall Recovery (%) Au Ag Au Ag Au Ag   Flowsheet A Composite BZ (Test GF35) 17.0 4.4 72.2 66.6 89.2 71.0 Composite   R-8 (Test GF37) 2.7 1.8 86.4 85.3 89.1 87.1 Composite GH (Test GF36) 11.0 1.8   72.6 82.9 83.6 84.7 Composite GH (Test GF41) 25.7 1.4 59.6 83.4 85.3 84.8   Flowsheet B Composite R-8 (Test GF38) 33.5 2.3 50.5 63.7 84.0 66.0 Composite   GH (Test GF39) 43.5 4.4 43.8 63.9 87.3 68.3 Composite BZ (Test GF40) 24.9 5.7   38.3 61.1 63.3 66.8 Composite SU-32B (Test GF42) 21.0 1.3 51.7 63.7 72.7 65.0   Composite SU-33 (Test GF43) 43.2 4.6 47.1 64.5 90.4 69.1 Composite SU-36A   (Test GF44) 41.0 3.8 32.6 56.6 73.7 60.4 Composite SU-36B (Test GF45) 9.7 2.3   42.1 55.7 51.8 58.0 Flowsheet C Composite GH2 (Test GF26) 68.3 8.31 21.9 62.7   90.4 71.2 Composite SU98 (Test GF27) 85.6 27.7 13.5 51.0 99.1 78.9 Composite   SU98 (Test GF25) 62.0 9.23 26.4 62.9 88.7 72.5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.1.6 Locked Cycle Tests _   Gravity Separation + Flotation Concentration In 2012/2013, six locked cycle   tests were conducted on four composite samples from the Valley of the Kings   Zone and the West Zone based on the test conditions developed from   comprehensive batch test work, including primary grind size, gravity   separation, rougher/scavenger flotation, and rougher concentrate cleaner   flotation. Four locked cycle tests were completed in 2012 on two master   composites, which consisted of one blend from the Valley of the Kings Zone   (VOK 1, 2, 3, and 4) and one from the West Zone (WZ 1 and 2). The procedure   included: Primary grinding targeting a moderate size of 80% passing 80 to 85   μm  Gravity concentration  Rougher and scavenger flotation with the   scavenger concentrate recycled  Rougher   concentrate cleaner flotation.  For   tests FLC1 and FLC3, the rougher concentrates were reground prior to cleaner   flotation. In an effort to activate gold-and silver-bearing minerals, copper   sulphate was added during the rougher and cleaner flotation stages. In 2013,   two separate locked cycle tests were conducted on two composites generated   from the upper and lower zones of the Valley of the Kings Zone. The test   procedure used was similar to that used for the locked cycle tests in 2012.   Table 13-6 shows the results of the six locked cycle tests, which are summarized   as follows: The average metal recoveries from the Valley of the Kings Zone   composites were approximately 97.8% for gold and 94.3% for silver.   Approximately 53.9% of the gold and 28.6% of the silver reported to the   gravity separation concentrate. The flotation concentrate contained   approximately 130 g/t Au, 252 g/t Ag, and 0.68% As.  Average recoveries from the master   composite of the West Zone were approximately 94.0% for gold and 90.8% for   silver. Approximately one-third of the gold reported to the gravity   separation concentrate. The flotation concentrate contained 48.6 g/t Au,   2,800 g/t Ag, and 0.24% As.  The   addition of copper sulphate, together with regrinding the rougher flotation   concentrates, did not appear to improve the recoveries of the target metals.  13-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 13-6: Locked Cycle   Tests Results 13-8 Composite Test No. Head Grade Calculated Gravity Concentration   Flotation Recovery Concentrate Grade Concentrate Grade Recovery Au (g/t) Ag   (g/t) S (%) Au (%) Ag (%) Au (kg/t) Ag (kg/t) Au (g/t) Ag (g/t) S (%) As   (ppm) Au (%) Ag (%) VOK-1 to -4 FLC1 24.2 33.6 2.92 54.2 30.5 11.7 9.1 181.3   354 48.1 8,249 43.9 61.7 VOK-1 to -4 FLC2 24.2 31.8 2.96 48.6 27.1 9.9 7.9   175.6 341 46.9 6,930 49.3 67.0 WZ-1 and -2 FLC3 6.0 225 3.03 32.0 1.3 1.7 2.7   52.6 3,096 43.5 2,622 59.2 88.5 WZ-1 and -2 FLC4 6.3 240 3.10 36.5 1.1 2.5   2.8 44.6 2,490 34.7 2,228 60.2 90.7 VOK ML FLC2 10.3 12.5 3.41 48.0 21.6 4.3   2.4 83.8 152 52.2 5,801 48.5 71.7 VOK MU FLC1 12.1 13.4 2.70 64.9 35.1 6.0   3.6 78.1 160 49.5 6,059 33.9 62.4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.1.7 Other Processing   Related Tests 13.1.7.1 Melting Test Work In 2014, FLS-DM conducted a   preliminary melting test on the tabling concentrate generated from the pilot   testing program (Section 13.2). The table concentrate contained approximately   20% of gold and 11% of silver. Smelted doré metal grades were 64% gold, 34%   silver, and 2% lead. 13.1.7.2 Solids Liquid Separation Tests Work In 2012,   Pocock Industrial Inc. (Pocock) conducted SLS tests on the flotation   concentrate and flotation tailings samples. The test program included sample   particle size analysis, flocculants screening and evaluation, and static and   dynamic thickening tests. 13.2 2013 Pilot Plant Testing Between September   2013 and February 2014, Pretivm contracted Strategic Minerals to process two   batches of bulk mineral samples generated from the Valley of the Kings Zone   using the Contact Mill facility located in Philipsburg, Montana.   Approximately 10,300 t was processed for the first campaign and approximately   1,200 t was processed for the second run. A combined process of gravity   separation and rougher/scavenger flotation with rougher concentrate cleaner   flotation was employed to treat the bulk materials. The gravity circuit   included a Kneslon concentrator and a Gemini table while a jigging and   tabling circuit to recover coarse free gold was also added towards the end of   the pilot plant test. No regrind circuit was applied to the rougher/scavenger   concentrates. Figure 13-2 shows the pilot plant flowsheet. The daily feed   grades to the mill ranged widely from less than 1 g/t to more than 130 g/t Au   for the samples processed by the 2013 processing campaign and from   approximately 40 to 300 g/t Au for the Cleo sample processed in 2014. Table   13-7 shows the test results summary as reported in the 2014 FS (Ireland et   al. 2014). The results demonstrated that the flowsheet used for the program   can effectively recover gold and silver and adapt well for a wide range of   feed grades experienced during the pilot testing. 13-9 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 13-2: Bulk Sample   Process Flowsheet l J Crusher 00 TSF I'1t:I TETRA TECH 13-10 Bb.Jgs Sec   Crushed Ore 8ln• cells L 00 Gravity Concentrate Filler Concentrate Ta   Flotaoon Concentrate 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 13-7: Bulk Sample   Processing Metallurgical Performances Notes:(1)Based on assay data from   Contact Mill laboratory. (2)Including cleanout. (3)Flotation concentrate   only. 13.3 Mill Operation Optimization/Expansion Test Work To support the   process plant optimization and throughput increase at the Brucejack Gold Mine,   Pretivm began a series of test work on the samples collected from operation   since 2017. The test work involved mineralogy analysis, grindability, gravity   separation, intensive leaching, and flotation concentration aspects. The   results were used to optimize the current plant operation and to project the   performance of the relevant circuits for the 3,800 t/d scenario. In addition,   SLS tests and tailings tests relating to mine backfill were also performed   for similar Table 13-8 lists the current test work programs, including   simulations. purposes. Table 13-8: Major Metallurgical Testing and   Simulations Programs 2017–2019 Note: SNF Canada (SNF); BV – Bureau Veritas   Commodities Canada Ltd.; RMS – RMS Corp.; FLSmidth Inc. (FLSmidth) 13.3.1   Sample Description Samples collected from the Brucejack Gold Mine operation   and drill core composites at the site were used in different testing programs   by different laboratories, as described in the following subsamples. 13.3.1.1   Mineralogy Analysis Samples – BV 2017 and PMC2018 In 2017 and 2019, BV and   PMCL, respectively, conducted separate gold deportment studies on final   flotation concentrates to support the plant operation. BVs work was based on   two flotation concentrate samples labelled as 17-07-03 NS Concentrate and 17-07-04   NS Concentrate. PMCL used one flotation concentrate sample labelled as   “LoCon”. 13-11 Lab Year Mineralogy Grindability Gravity Leaching Flotation   Thickening Tailings SNF 2016/2017    Gekko 2017  ALS 2018    BV 2017    PMCL 2018  FLSmidth 2018   Pocock 2019  RMS 2018    Year Feed Metal Recovery (%) Product Grade (g/t) Tonnage (t)   Calculated Grade (g/t) Table Con Table Con + Table Middlings Gravity+   Flotation Con Table Con Flotation Con Au(2) Ag(2) Au(1) Ag(1) Au(1) Ag(1) Au   Ag Au(1) Ag(1) Au(3) Ag(3) 2013 10,302 17.5 17.1 41.8 18.2 47.6 21.0 97.5   86.9 259,487 110,146 79 129 2014 1,203 82.6 59.7 47.9 36.6 56.2 44.0 98.0   96.3 247,999 136,877 398 402 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.3.1.2 Comminution Test   Work Samples – ALS 2018 ALS, located in Kamloops, BC, performed comminution,   gravity, and flotation tests. For the comminution tests, nine samples were   received and tested, which included eight drill core samples and one plant   SAG mill feed sample. Chemical analyses were conducted on all nine samples   and mineralogical analyses were completed on six of samples through x-ray   diffraction (XRD). 13.3.1.3 Metallurgical Processing Test Work Samples – Gekko   2017 and ALS 2018 An intensive cyanide leaching test program was conducted at   SGS Canada Inc. (SGS) laboratory facility in Burnaby, BC by using the Gekko’s   intensive leach procedure. Two sealed pails of Kneslon concentrate pulp   samples labelled as Table Feed Sample 21-22/July/2017 (TF2) and Table Feed   Sample 23-24/July/2017 (TF1) were used for the testing at the SGS Burnaby   laboratory. The pulp samples were decanted to remove the supernatant water   and then prepared for subsequent head characterization and intensive leaching   tests. Table 13-9 shows the sample head assay results. Table 13-9: Head Assay   Results (Gekko 2017) ALS performed metallurgical test work, including   comminution, gravity, and flotation testing. Four composites (H, M, L, and A)   with varying feed grades were prepared from 42 subsamples. The metallurgical   composite samples were used in flotation tests to optimize test conditions.   Two selected variability composite samples (West Zone (WZ) and Galena Hill   (GH) Zone) were tested using the developed test conditions. Table 13-10 lists   the sample head assaying results. The gold and silver assays were completed   using a metallic gold assay (by screening) method except for Sample A, WZ, GH   and GRG Comp 2. Gold and silver concentrations varied from 3.1 to 16.2 g/t Au   and 36 to 398 g/t Ag. Table 13-10: Head Assay Results (ALS 2018) S(-2) –   sulphide sulphur; C – carbon; TOC – total organic carbon Note: For the   operation optimization tests, two flotation samples were used—one was a   rougher concentrate sample and the other was a third cleaner concentrate—from   the Brucejack Gold Mine process streams. The purpose of the test 13-12 Sample   ID Au (g/t) Ag (g/t) S (%) As (%) S(-2) (%) C (%) TOC (%) Composite L 3.13 49   4.00 0.063 3.95 0.73 0.03 Composite M 5.73 60 3.60 0.087 3.56 0.82 0.04   Composite H 16.20 76 3.12 0.043 3.08 0.56 0.08 Composite A 4.10 53 4.02 0.062   3.98 - - Composite WZ 14.70 398 2.68 0.016 - - - Composite GH 5.42 73 2.61   0.044 - - - GRG Comp 2 9.50 36 3.64 0.048 - - - Assay Method Au (g/t) Ag (g/t)   TF1 TF2 TF1 TF2 Screen Metallic – Fire Assay 8,105 5,992 3,836 3,521 Fire   Assay 8,875 6,510 4,925 3,740 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE was to investigate the   potential gravity concentration of rougher concentrate following regrinding   and for further upgrading of the third cleaner concentrate using conventional   flotation and flotation column methods. Table 13-11 shows the head assay   results of the two processing samples. Table 13-11: Head Assays of Processing   Samples 13.3.1.4 Solid/Liquid Separation Test Work Samples – SNF 2016/2017,   FLSmidth 2018, and Pocock 2019 In 2016 and 2017, SNF provided a preliminary   flocculant and coagulant screening tests using static settling methods.   Tailings samples were used in both tests; the 2016 samples contained 27.9%   solids at an initial pH of 6.8 to 7.0; however, the 2017 samples were not   specified in the report. FLSmidth conducted the SLS test work in Midvale, Utah   on both the flotation concentrate and tailings samples collected from the   Brucejack Gold Mine. The objectives were to optimize settling characteristics   and to evaluate the performances of the two tailings and concentrate   thickeners to accommodate the 3,800 t/d throughput. Pocock tested two   tailings samples collected from the Brucejack mill during the operation upset   conditions in 2019. Elevated fine clay materials were found suspended in the   thickener overflow which were not flocculating properly with the plant   flocculant reagent. The two samples came from tailings material produced on   January 5 and January 8, 2019. The purpose of this testing was to assist   plant operations to clarify the tailings thickener overflow. 13.3.2   Mineralogical Analysis on Flotation Tailings and Tailings Thickener Underflow   In 2019, a mineralogical determination work was conducted on flotation   tailings thickener feed and underflow by PMCL for X-ray diffraction (XRD)   analysis and clay speciation analysis. The mineralogical study was to   investigate possible causes for settling issues in the tailings thickener.   The investigation shows that samples contain predominantly quartz (44 to 53%   wt.) and muscovite/illite (37.8 to 49.5% wt.), and minor calcite (3.5 to 7%   wt.), chlorite (0.8 to 2.8% wt.), albite (<2.2% wt.), and pyrite (0.6 to   1.9% wt.). The suspicion that swelling clays might cause the settling issue   in the thickener tank could not be substantiated by the completed clay   speciation study as the clay mineral fraction in all examined samples   contains predominantly non-swelling muscovite (polymorph 2M1) with minor   illite and chlorite. Elevated levels of fine-grained sericite in the   thickener feed (up to 49.5% wt.) are not matched with the thickener   underflow, suggesting that the fine 2M1-muscovite/illite may cause poor   thickening behavior/settling issues. 13.3.3 Mineralogical Analysis on   Flotation Concentrates BV and PMCL investigated the gold deportment in the   final flotation concentrates produced from 2017 and in 2018, respectively, to   support plant operation optimization. In 2017, BV conducted its investigation   on two concentrate samples by using Quantitative Evaluation of Materials by   Scanning Electron Microscopy (QEMSCAN) Particle Mineral Analysis (PMA) and   QEMSCAN Trace Mineral 13-13 Sample Grade (g/t or %) Au S S(s) As Rougher   Concentrate 85 37.5 37.5 0.21 Third Cleaner Concentrate 111 44.2 44.2 - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Search (TMS) protocols. The   gold concentration was determined by using an energy dispersive spectrometer   (EDS) and Brucker software. BVs study outlines the following major   observations and conclusions: The gold grades of the two concentrates are 154   g/t Au and 57 g/t Au. The majority of the gold occurred as native gold and   gold electrum. Table 13-12 lists gold grade and deportment percentage with   minerals by mass of the two samples.    The average gold grain size was 11 to 13 μm for both the samples;   however, the majority of gold grains were in a range of 1 to 5 μm, as shown   in Figure 13-3.  Approximately 75% of   the gold by weight in the two concentrates was liberated as determined by two   dimensions. The unliberated gold presented as exposed surfaces and mostly   attached to sulphide minerals. The liberated and attached gold accounted for   over 99.5% the gold in the concentrates. The unliberated gold was found   locked with pyrite and non-sulphide gangue minerals and accounted for less   than 0.5% of the total gold.  The   investigation into the mineral composition of the two samples indicated that   sulphide minerals were approximately 89% by weight, which were dominated by   pyrite. The non-sulphide minerals were approximately 11%, which were mainly   included quartz and clay minerals.    High liberation of sulphide minerals was reported as 90% for both   samples; approximately 56% non-sulphide gangue minerals were also presented   as liberated.  Table 13-12: Gold   Deportment and Associations of Two Flotation Con – BV 2017 Figure 13-3: Gold   Grains Distributions with Size Range 13-14 Sample Grade Au (g/t) Au Mass   Deportment % by Minerals Native Au (Au) Electrum (Au, Ag) Acanthine (Ag2S)   Uytenbogaardtite (Ag3AuS2) 17-07-03 NS Concentrate 153.6 9.2 86.3 3.6 0.9   17-07-04 NS Concentrate 57.2 86.0 4.5 0.7 8.8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE In 2018, PMCL conducted a   separate gold deportment study and mineralogy determination on one sample   labelled as “LoCon”. Tescan Integrated Mineral Analyser (TIMA) was used to   determine the sample mineral composition, mineral abundance, liberation, and   grain size information. Gold deportment was investigated using a Tescan Vega   3 scanning electron microscope (SEM) equipped with an EDS on polished   sections of the gravity products obtained from a Mozley table and CNT   Hydroseparator. The gold grade of the tested sample was assayed as 34.4 g/t   Au. Similar to BVs observations, gold was found largely present in the form   of electrum grains which were mainly finer than 8 μm. The overall gold grain   size was between 16 to 32 μm. Approximately 71% of the gold grains were free   and 21% of the gold was attached to silicates but with exposed surfaces. Only   a trace amount of the gold was locked in grains within pyrite in a size   typically less than 2 μm. The minerals are mainly composed of 76% pyrite, 12%   quartz, 6% sercite/muscovite, 2% feldspar with some clay minerals. 13.3.4   Comminution Test Work The key comminution test work generated such parameters   as crushing work index, grinding work index (JK Drop Weight, SMC, and Bond   ball mill work index), rock hardness, and abrasion. SGS conducted an   additional comminution test using the SAG Power Index (SPI) test procedure.   Table 13-13 shows the Bond working index test results. The Bond ball work   index ranged from 13.5 to 19.8 kWh/t of the twelve comminution samples,   including three tests on three composite samples producing relatively average   values between 15.1 and 16.0 kWh/t. The Bond crushing index was observed to   be 6.5 to 17.6 kWh/t. All the samples showed relatively mild abrasive values   except for SIL H8 sample. Table 13-13: Bond Test Results (ALS 2018) Table   13-14 lists the results of JK Drop Weight testing for the SAG Feed, AND, CGL,   SIL H8, and VSF samples. The remaining four samples were subjected to SMC   testing and results are shown in Table 13-15. The test results show that the   SAG parameters (A x b) vary significantly from 29.1 to 78.7. SAG Circuit   Specific Energy (SCSE) values ranged from 7.49 to 11.97 kWh/t for all the   tested samples. 13-15 Sample ID BWi (kWh/t) CWi (kWh/t) Ai (g) Specific Gravity   SAG Feed 14.4 15.4 0.078 2.73 AND 16.6 17.6 0.025 2.78 SIL H8 16.8 11.6 0.445   2.66 CGL 16.5 6.5 0.043 2.84 VSF 14.9 10.0 0.135 2.77 ARG 19.8 7.5 0.174 2.70   V6 17.2 13.4 - 2.85 P1 15.4 14.8 - 2.83 P2 13.5 - - - Composite H 16.0 - - -   Composite M 15.1 - - - Composite L 15.5 - - - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 13-14: JK Drop Weight   Test Results (ALS 2018) Table 13-15: SMC Test Results and Parameters Derived   from SMC Tests (ALS 2018) 13.3.4.1 Comminution Circuit Simulations Contact   Support Service Inc. (CSS) performed a primary grinding circuit modelling   using JKSimMet. An additional comparison was performed by Weir Minerals using   their proprietary modeling simulations. The input data was generated using   comminution testing results obtained by ALS and SGS and site operating   information. The underground mine samples used for the testing consisted of   eight rock types representing various lithologies of the mill feed. On   November 23, 2017, a grinding circuit survey was conducted to collect   operation data on the samples from belt cuts and process slurry streams. The   simulations indicated that the grinding circuit has a sufficient capacity for   the increased mill feed rate of 3,800 t/d. 13.3.5 Gold and Silver Recovery   Test Work In 2017, under the Gekko’s guide SGS conducted an intensive cyanide   leaching test program at SGSs laboratory facility in Burnaby, BC. The test   program was to determine the amenability of the Kneslon concentrate samples   from the Brucejack Gold Mine to intensive cyanide leaching. ALS also   conducted a comprehensive metallurgical test program to investigate the   gravity and flotation response of new samples to various test conditions,   mainly primary grind size, reagent scheme, and circuit arrangement of the   flotation circuit. Both the open and locked cycle tests were conducted using   a flowsheet similar to the Brucejack Gold Mine operation. The major   conclusions and recommendations of the metallurgical test work by Gekko/SGS   and ALS are summarized in the following subsections. 13-16 Sample ID DWi Mia   (kWh/t) Mih (kWh/t) Mic (kWh/t) Specific Gravity A b A*b ta SCSE (kWh/t)   (kWh/m3) ARG 3.5 11.3 7.3 3.8 2.75 64.5 1.22 78.7 0.74 7.49 P1 6.4 17.9 13.1   6.8 2.82 63.6 0.69 43.9 0.40 9.7 P2 5.3 15.1 10.6 5.5 2.88 57.6 0.95 54.7   0.49 8.88 V6 9.9 25.1 20.1 10.4 2.85 67.6 0.43 29.1 0.26 11.97 Sample ID A b   A*b ta SCSE (kWh/t) Specific Gravity SAG Feed 60.2 0.76 45.8 0.48 9.43 2.78   AND 65.9 0.50 33.0 0.49 11.14 2.82 CGL 51.1 1.32 67.5 1.05 7.96 2.76 SIL H8   67.9 0.90 61.1 0.54 8.21 2.70 VSF 58.0 0.82 47.6 0.84 9.21 2.75 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.3.5.1 Gravity Testing   Results – ALS 2018 Figure 13-4 shows the gravity testing results. Similar to   previous gravity testing findings and the current operation, a significant   amount of the gold is gravity recoverable gold. The gravity gold recoveries   vary with the mineralization and gold head grades of the feed samples. Figure   13-4: Gravity Results Summary – Composite Samples – ALS 2018 13-17 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.3.5.2 E-GRG Testing   Results – ALS 2018 ALS performed an extended gravity recoverable gold test   using GRG determination procedure on the Composite 2 sample. The results   confirmed that most of the gold within the sample was gravity recoverable.   The gold recovered at each of the three grind sizes is plotted in Figure   13-5. The overall gold recovery was 70.5% after the three recovery passes,   which is lower than the previous tests by Knelson in (Section 13.1.2), but   still showed a high amenability to gravity recovery. 2012 that showed 80.3%   GRG Figure 13-5: E-GRG Test Results 13.3.5.3 Intensive Leaching – Gekko 2017   Five intensive cyanide leaching tests were performed on the two Knelson   concentrates samples with varied cyanide concentrations and pulp densities.   The leaching pH level was maintained between 10.5 to 11.0 with the dissolved   oxygen (DO) concentration of over 20 ppm for all the tests. SGS used the   Gekko’s test procedure. The following observations were made from the   leaching tests: Sample TF1 produced an over 99% extraction rate of gold and   silver based on assays of the residual solids; Sample TF2 reached a similar   extraction rate of over 99% extraction of gold and silver.  In addition, a further increase in cyanide   concentration to 3% sodium cyanide (NaCN) or using hydrogen peroxide as an   alternative oxidant did not improve the overall metal leaching   recoveries.  13.3.5.4 Diagnostic Leach   of Gravity Concentration Tailings – BV 2019 In 2019, BV conducted a   diagnostic leach test on gravity tailings produced from the Brucejack Gold   Mine. The tailings sample was from the secondary gravity concentration by a   centrifugal concentrator. Duplicate tests were conducted. The test results   show that the tailings sample responds well to the direct cyanide leaching.   The test results are summarized in Table 13-16, showing gold occurrence in   free gold form and associated forms with different mineral phases. More than   99% of the gold in the tailings product was recovered by gravity   concentration (gravity recoverable, 15.2%) and cyanidation (cyanide soluble,   84.1%). 13-18 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 13-16: Diagnostic Leach   Test Results – Gravity Concentration Tailings (2019) 13.3.5.5 Gravity   Concentrate Smelting Tests – XPS 2019 In 2019, Expert Process Solution (XPS)   conducted smelting test work on a low-grade gravity separation table   concentrate. The test work was to determine the optimal conditions to recover   gold by a combination of calcination and smelting. Characterization of the   table concentrate showed that the sample contains approximately 13,100 g/t   gold and 7,700 g/t silver, along with significant amounts of pyrite (FeS) and   minor amounts of quartz (SiO2), arsenopyrite (FeAsS), uytenbogaardite   (Ag3AuS2), and galena (PbS). The testing shows that using the roasting and   smelting combined treatment, with the same flux addition as the baseline, led   to losses of 0.46% of the gold and 0.21% of the silver to slag, compared to   using direct smelting, which resulted in much higher gold and silver losses   to slag (56.6% of the gold and 73.7% of the silver). 13.3.5.6 Batch Flotation   Test Results – ALS 2018 Both rougher and cleaner flotation tests were   conducted to explore the impact of various testing conditions on gold and   silver metallurgical performances. The flotation tests were conducted on the   gravity tailings obtained from various composite samples. The major   observations/conclusions of the rougher flotation tests are noted in the   following bullet points and shown in Figure 13-6 and Figure 13-7: At the   tested primary grind sizes of 80% passing between 88 and 216 μm, the primary   grid sizes had a modest effect on the flotation performance of the tested   composite samples.  There was no   obvious effect between using mild steel rod grinding media and using stainless   steel rod media in a rubber liner mill.    Little success was obtained at the rougher and scavenger stages by   modifying test conditions for concentrate grade improvement, including   potassium amyl xanthate (PAX) vs. A208/sodium isopropyl xanthate (SIPX) or   D233/MX-900; higher pH cleaner flotation; pH adjustment reagents (lime vs.   soda ash); collector dosage; and incorporation of copper sulphate.  13-19 Recovery Stage Distribution, % Au   Test 1 Test 2 Stage 1 - Gravity recoverable 13.3 15.2 Stage 2 - Cyanide   soluble 86.4 84.1 Stage 3 - Primarily associated with carbonaceous minerals   0.12 0.23 Stage 4 - Primarily associated with calcite/dolomite/pyrrhotite   minerals 0.01 0.03 Stage 5 & 6 - Primarily associated with sulphides 0.12   0.21 Residue - Insoluble or associated with preg-robbing and other refractory   minerals 0.02 0.20 Total 100.0 100.0 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 13-6: Rougher   Flotation Tests on Composite H and L Figure 13-7: Rougher Flotation Tests on   Composite M 13-20 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The major   observations/conclusions of the cleaner flotation tests are noted in the   following bullet points and shown in Figure 13-8: Varied cleaner flotation   responses were observed among the tested samples. At a primary grind size of   80% passing between 88 and 102 μm, Composites L and A produced low-grade   cleaner concentrates of 32 g/t Au and 34 g/t Au at a gold recovery of 84% and   86%, respectively. Composites H, GH, and WZ produced higher-grade cleaner   concentrates of 67 g/t Au, 85 g/t Au, and 104 g/t Au with higher gold   recoveries of 95%, 94%, and 88%, respectively.  Finer primary grind size appeared to   slightly improve the gold grade of the cleaner flotation concentrate. At a   primary grind size of 80% passing 165 μm, the cleaner gold recovery was 87%   grading at 62 g/t Au. At a finer primary grind size of 80% passing 91 μm, the   gold grade increased to 69 g/t and the gold recovery decreased to 84%.  Regrinding the rougher concentrates to an   80% passing range of 36 to 72 μm, as well as increasing pH level to 10 and   10.5 noticeably improved the cleaner concentrate gold grade. The highest gold   grade was 149 g/t at a recovery of 82% when regrinding the rougher   concentrates to an 80% passing of 36 μm.    Rougher scavenger tailings were found mainly composed of quartz and   muscovite, as well as small amounts of sulphide minerals and other   non-sulphide gangue minerals.  The   current flotation reagent scheme should remain. The reagent optimization   tests confirmed that some alternatives can improve the concentrate grades;   however, this may also result in a high sulphur content in the tailings.  Reducing rougher and rougher scavenger   retention time did not significantly reduce gold recovery, although a reduced   cleaning retention time may slightly impact final concentrate grade.  A coarse floatation feed grind size   resulted in only a modest decrease in gold recovery.  Figure 13-8: Cleaner Flotation Tests on   Composite L, A, H, GH, WZ, and M 13-21 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.3.5.7 Locked Cycle   Gravity-Flotation Testing Results – ALS 2018 Two locked cycle flotation tests   were conducted using a combination of gravity and flotation concentrations   for gold and silver recovery. The gravity circuit for both tests was completed   as a separate stage, following which the gravity tailings were tested in the   locked cycle flotation tests. Figure 13-9 and Figure 13-10 show locked cycle   test flowsheet No. 1 and No. 2, respectively, which differ from each other at   the flotation stage. Flowsheet No. 1 uses a three-stage cleaner flotation   circuit which is fed by rougher concentrates. Flowsheet No. 2 is based on a   two-stage cleaner flotation fed by rougher concentrates 2 to 4, while rougher   concentrate 1 directly reports to the second cleaner flotation stage. Figure   13-9: Locked Cycle Test Flowsheet No. 1 13-22 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 13-10: Locked Cycle   Test Flowsheet No. 2 Table 13-17 summarizes the test conditions for the two   locked cycle flotation tests. Both locked cycle tests were completed at a   primary grind size of 80% passing 100 μm and at a natural pH with PAX as   sulphide collector. Table 13-17: Locked Cycle Testing Conditions Table 13-18   summarizes and compares the test results for the two flowsheets. In the first   locked cycle test recovered approximately 31% gold and 4% silver to a gravity   concentrate, grading at 897 g/t Au and 1,400 g/t Ag. The second locked cycle   test recovered more gold and a similar amount of silver to a gravity   concentrate of 37% gold and 4.5% silver grading at 1,596 g/t Au and 2,053 g/t   Ag. The flotation concentrates produced in the first locked cycle test   contained 34 g/t Au and 559 g/t Ag, which translated to recoveries of 63%   gold and 91% silver. The second locked cycle flotation test produced a lower   grade concentrate of 28 g/t Au and 450 g/t Ag which represented recoveries of   59% gold and 90% silver. The lower grade could be attributed to the flowsheet   configurations. 13-23 Testing Conditions Unit Flowsheet No. 1 Flowsheet No. 2   Primary Grinding Size P80 μm 100 100 Rougher/Scavenger Flotation pH - Natural   Natural Collector PAX g/t 20/10 5/15/10 Retention Time min 8/4 2/6/4   Cleaner/Scavenger Flotation pH - Natural Natural Collector PAX g/t 0/0/0/5   0/0/5 Retention Time min 4/3/2/2 4/6/2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 13-18: Locked Cycle   Test Results A further cleaner flotation stage was added to the second locked   cycle testing to treat the second cleaner flotation concentrates. As shown in   Table 13-19, a high-grade concentrate was produced grading at 32.2 g/t Au and   536 g/t Ag. Table 13-19: Third Cleaner Flotation Results on the Second Locked   Cycle Test ICP analysis, whole rock analyses, and sizing were conducted on   concentrates and tailings samples generated from the two locked cycle tests.   The following observations are made: Most of the sulphur was in sulphide   form.   Organic carbon was   concentrating into concentrates rather than tailings.  Arsenic assayed as 0.6% and 0.5 % for the   first and second final concentrates, respectively. Particle size of the   concentrates was approximately 80% passing 100 μm, while cleaner scavenger   tailings presented a much smaller size between 15 and 20 μm.  13-24 Products Flowsheet No.2 Wt (%) Grade   (g/t or %) Recovery (%) Au Ag S Au Ag S Feed (Second Cleaner Concentrate)   11.3 28.0 450 33.0 58.7 90.0 94.5 Third Cleaner Concentrate 9.6 32.2 536 38.9   57.7 89.0 92.4 Third Cleaner Tailings 1.7 3.03 32 4.87 1.0 0.9 2.1 Products   Wt (%) Grade (g/t or %) Recovery (%) Au Ag S Au Ag S Flowsheet No. 1 Gravity   Concentrate 0.2 897 1,400 54.8 31.4 4.3 2.4 Flotation Concentrate 9.1 34.2   559 40.5 63.0 90.8 92.3 Tailings 90.7 0.30 3 0.24 5.6 4.8 5.4 Head 100 4.97   56 4.01 100 100 100 Flowsheet No. 2 Gravity Concentrate 0.1 1,596 2,053 53.5   36.7 4.5 1.7 Flotation Concentrate 11.3 28.0 450 33.0 58.7 90.0 94.5 Tailings   88.6 0.28 4 0.17 4.6 5.5 3.8 Head 100 5.39 56 3.94 100 100 100 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.3.5.8 Optimization Tests –   ALS 2018 Two samples—a rougher concentrate sample and a third cleaner   concentrate—were collected from the Brucejack Gold Mine process streams and   tested to investigate the potential gold recovery by gravity concentration   from the rougher concentrate following regrinding and further upgrading the   third cleaner concentrate using conventional flotation and flotation column   methods. Table 13-20 shows the head assay results of the two samples. Table   13-20: Head Assays of Processing Samples The rougher concentrate samples were   subject to a combined treatment of a gravity separation and a three-stage   cleaner flotation along with a cleaner scavenger flotation stage. Regrinding   was incorporated prior to the gravity separation in four of five tests.   Regrind time and pH level were varied to investigate the impacts. The   following conclusions were made regarding the test work (also see Figure   13-11):  Without regrinding (T31), gold   recovered to gravity concentrate was low. The flotation circuit generated a   gold recovery of 98% at a grade of 122 g/t Au.  At a regrind size 80% passing approximately   37 μm (Tests 32/33/34), the gravity gold recovery was between 19 and 25%, and   the gold grade of the flotation concentrates was found to be 166 g/t Au at a   gold recovery of 91%. Increasing the pH level seemed to have no impact on the   gold grade.  At a regrind size 80%   passing approximately 21 μm (T35), gold gravity recovery increased to 35%,   while the flotation concentrates contained 611 g/t Au at a high pH level of   10 to 10.5. Figure 13-11: Gravity and Flotation Optimization Tests 13-25   Sample Grade (g/t or %) Au S S(-2) As Rougher Concentrate 85 37.5 37.5 0.21   Third Cleaner Concentrate 111 44.2 44.2 - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The third cleaner concentrate   samples grading at 111 g/t Au were subject to a column flotation test and   compared with a one-stage conventional flotation process. As shown in Table   13-21, the test results seem to show: The conventional flotation test (T28)   upgraded the gold grade to 121 g/t Au at a gold recovery of 99%  The column flotation test (T29), as a   comparison, improved the gold grade to 147 g/t at a gold recovery of   95%.  Table 13-21: Conventional and   Column Flotation Results 13.3.6 Solid and Liquid Separation Test Work In   2016, SNF provided preliminary flocculant and coagulant screening tests using   static settling methods. The test results showed that using 910 VHM alone can   reach the target supernatant clarity, settling rate, and compaction. In 2017,   SNF performed another screen test to control the tailings thickener overflow   clarity. The results indicated that using flocculant 910 VHM alone can not   prevent carryover of fines; coagulant DB45 VHM should be also added after   adding flocculant. In 2018, FLSmidth performed a comprehensive SLS test program   in its laboratory located in Midvale, Utah on both the flotation concentrate   and tailings samples collected from the Brucejack Gold Mine operation. The   objectives of this test program were to optimize settling characteristics and   to evaluate the performance of the two thickeners to accommodate the 3,800   t/d throughput. The test results and conclusions are summarized as follows:   The flocculant that produced the best overflow clarity and settling   velocities was a non-ionic polyacrylamide flocculant with a medium molecular   weight. The recommended flocculant is AN 920 SH, which can be applied for   both the tailings and the concentrate thickening. The suggested flocculant   dosage is between 50 to 80 g/t for the tailing thickener and approximately 15   g/t for the concentrate thickener. In addition, better overflow clarity   results using AN 920 SH were noticed during thickening testing, compared to   the treatment of thickening followed by coagulant clarification. The use of   fresh water rather than process water for flocculant dilution and makeup is   also critical in optimizing performance of thickeners.  The optimum solids concentration for   flocculation was suggested to be 4 to 10% by weight for the tailings   thickener feed materials and approximately 16% by weight for the concentrate   thickener feed.  The solids density of   the tailings thickening underflow was estimated between 51 to 63.5% by weight   using the existing thickener. The corresponding solids density of the   concentrate thickener underflow was estimated as 76% by weight.  13-26 Products Wt (%) Grade (g/t or %)   Recovery (%) Au S S(-2) Au S S(-2) Conventional Flotation Feed 100 110 44.6   44.5 100 100 100 Concentrate 90.2 121 49.0 48.9 98.6 99.1 99.1 Tailings 9.8   15.2 4.17 4.14 1.4 0.9 0.9 Column Flotation Tests Feed 100 116 46.6 46.5 100   100 100 Concentrate 75 147 51.0 50.9 95.3 82.1 82.1 Tailings 25 22.0 33.4   33.3 4.7 17.9 17.9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE With proper thickener feed   conditioning including 15% by weight feed dilution and use of the AN-920 SH   flocculant at the recommended dosages, the existing concentrate thickener   would have sufficient capacity for the 3,800 t/d throughput. Careful   consideration must also be given to froth suppression. Figure 13-12 shows the   solids capacity as a function of underflow solids concentration for the   concentrate thickener.  Figure 13-12:   Concentrate Thickener Capacity With proper feed conditioning, including 10%   solids by weight diluted feed and use of the approximately 80 g/t AN-920SH,   the existing tailing thickener can handle the increased capacity of 3,800 t/d   and achieve an underflow density of 64% solids. Going significantly beyond   this throughput would require a new tailings thickener. FLSmidth recommended   the 64% underflow solids concentration for the tailings thickener based on   two considerations: the yield stress will be greater than 300 Pa at 65% by   weight solids (a critical point for downstream slurry handling equipment) and   the operation may encounter difficulty. Figure 13-13 shows the tailings   thickener underflow solids density variations with retention time.  13-27 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 13-13: Tailing   Thickener Underflow Concentration with Time In 2019, two tailings samples   were collected from the mill during the upset operation conditions that   elevated fine-clay materials suspended in the thickener overflow which were   not flocculated properly with the flocculant reagent (SNF 910 HH). The two   samples were sent to and tested at the Pocock laboratory in Salt Lake City,   Utah. The purpose of this testing was to assist plant operation to clarify   the tailings thickener overflow by evaluating settling rheology and   filtration characteristics of the tailings. Various flocculant and coagulant   reagents were screened to achieve clear overflow (less than 150 ppm total   suspended solids (TSS)), acceptable settling rates, and underflow densities   in static and dynamic thickening tests. Pulp rheology tests were completed on   all thickened materials to estimate the maximum underflow density. Pocock   concluded that using both the low cationic (SNF 4125 SH) and the anionic   plant flocculant (SNF 910) appeared to meet the requirements of overflow   clarity. The test results indicate that to achieve reasonable overflow   clarity, a high flocculant dosage would be required. The resulted thickener   underflow solids density was estimated between 53 to 57% for a conventional   thickener. The solid density can be increased to over 57% solids density if a   deep cone thickener is in place. The test results indicated that the feed   solids density range needs to be maintained in a range of 10 to 12.5% by   weight. 13.4 Mill Operations Optimization / Expansion Process Simulations   Simulations were conducted by various vendors and consultants to evaluate the   major circuit performances for the Brucejack mill expansion. The grinding   circuit, gravity recovery circuit, and flotation circuit modelling are   described in the following subsections. 13.4.1 Grinding Circuit CSS performed   simulations on the primary grinding circuit using JKSimMet software, which   were compared with another simulation method proprietary to Weir Minerals.   The input data for both simulations include comminution test results from ALS   and SGS and site operating data. 13-28 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 13.4.1.1 JKSimMet CSS used   JKSimMet software to simulate comminution circuit performances in two phases.   Phase 1 estimated the maximum mill throughput at standard operations, which   was outlined in the plant survey data completed under routine operating   conditions. Phase 2 estimated the increased mill throughputs supported by the   Phase 1 data and a significantly coarsening grind product particle size.   Phase 1 Phase 1 results were reported in the January 18, 2017 Phase 1 report   titled Results Simulation Study and Throughput Optimization of the Existing   Brucejack Circuit Based on the November 23, 2017 Plant Survey (CSS 2017a).   The report indicated that at the current 2,700 t/d mill feed rate, the   grinding circuit was operated at well under the available grinding capacity,   with the SAG mill operating at 51% of the installed motor capacity and the ball   mill at 77% of the installed motor capacity. The pebble crusher was not being   used. If the current grind size is maintained for future mill expansion, the   existing grinding operation will be limited first by the ball mill capacity   before reaching the maximum SAG mill capacity. The simulations showed that   the 3,800 t/d target could be readily achieved for all rock (ore) types while   maintaining a targeted product size 80% passing of 90 μm for the ore hardness   range tested. Table 13-22 shows the simulation results for the mill feed rate   of 3,800 t/d. November 23, 2018 baseline sample. The current feed ore, as   listed in Table 13-22, represents the 13-29 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Table 13-22: JKSimMet 3,800 t/d Results at 92%   Availability (1)Ore types sorted by A x b values from softest to hardest   resistance to impact breakage; hardness data can be found in Section 13.4.4.   (2)Ball mill critical speed was set as of 79.0% to all simulations. Notes:   13-30 Ore Type(1) SAG Mill Circuit Ball Mill Circuit New Feed Combined Feed   SAG Mill SAG Screen O/S SAG Screen U/S Ball Mill(2) Cyclone Cyclone U/F   Cyclone O/F Rate (t/h) F80 (mm) Rate (t/h) F80 (%) Critical Speed (%) Power   Draw (kW) Rate (t/h) P80 (mm) P80 (μm) Power Draw (kW) Ball Charge v/v (%)   Circulation Load (%) Feed Solids (%) No. Pa (kPa) Solids (%) Solids (%) P80   (μm) ARG 172 112.8 176 111.8 55.3 937 4.13 18.0 731 1,980 34.0 316 52.6 6   123.0 79.4 25.4 90 CGL 172 112.8 177 111.6 58.1 993 5.12 17.8 884 1,980 34.0   287 52.9 6 104.7 77.2 27.7 90 SIL H8 172 112.8 177 111.6 57.6 978 5.07 17.9   781 1,980 34.0 232 53.9 5 106.3 76.5 32.0 90 P2 172 112.8 178 111.4 58.3   1,008 5.63 17.9 879 1,980 34.0 206 56.2 5 80.0 73.6 37.7 90 VSF 172 112.8 179   111.1 61.9 1,066 6.97 17.6 971 1,980 34.0 224 54.6 5 97.5 75.6 33.6 90   Current Feed Ore 172 112.8 179 111.2 60.7 1,044 6.77 17.7 951 1,895 32.0 220   54.9 5 93.1 75.2 34.5 90 P1 172 112.8 179 111.1 60.6 1,048 6.91 17.7 946 1,980   34.0 218 55.3 5 90.0 74.9 35.2 90 AND 172 112.8 182 110.4 64.9 1,132 9.80   17.4 1,145 1,980 34.0 229 55.1 5 97.4 76.1 33.8 90 V6 172 112.8 183 110.2   64.8 1,134 10.72 17.4 1,203 1,980 34.0 232 55.3 5 97.9 76.3 33.7 90 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The simulation results   indicated that by adjusting the SAG mill power draw, the target 3,800 t/d   capacity can be reached for all the simulated ore types using the same grind   size as the present operation. CSS noted that the maximum throughput could be   as high as 4,239 t/d at the same grind size by increasing the SAG mill   critical speed and steel ball charge rate, depending on ore characteristics.   CSS recommended including an additional operating cyclone, adjust feed   pressure of the cyclone, and feed solids density per the targeted operating   conditions as outlined in the report (CSS 2017a). Phase 2 The Phase 2   simulation work provided supplemental information to the Phase 1 work. The   modelling was based on an increased product grind size to determine the   potential of the existing grinding circuit. The results are included in the   report titled Optimization to Maximize Throughput of the Existing Brucejack   Circuit Based on the November 23, 2017 Plant Survey (CSS 2017b). A coarse   grind size used in the Phase 2 simulation was based on the ALS flotation   testing results conducted in 2017/2018, which indicated that the impacts of   increased grind size on flotation performance were minor to moderate for most   ore types. It was reported that at a significantly coarser float feeds of up   to 80% passing 160 μm, the recovery drop was relatively modest of up to 5%.   At this coarse grind size, the simulations by CSS showed that the throughput   of the grinding circuit can reach up to approximately 10,000 t/d depending on   ore hardness. The Phase 2 simulation findings concluded that to achieve the   high throughput, using wider grate openings, maximizing the pebble crusher   capacity, as well as adjusting the mill speed and charge load would be   required, along with undertaking modifications to pumping, water supply,   piping, and cyclones. However, it should be noted that the upstream crushing   and downstream process/tailings handling circuits would be well under   capacity. Therefore, the Phase 2 scenario was not incorporated into the mill   upgrading. 13.4.1.2 Weir Minerals Weir Minerals undertook modelling of the   grinding circuit using their internal proprietary simulation software. The   software incorporated the ALS laboratory comminution data, as well as SPI   data generated by SGS. Several simulations were conducted by Weir Minerals,   which showed that there is excess capacity in the current grinding circuit,   which can reach the 3,800 t/d target 13.4.1.3 Krebs – FLSmidth Four of the   six hydro-cyclones are currently in operation with the remaining two on   standby mode. Krebs-FLSmidth (Krebs) performed simulations to project the   performance of these hydro-cyclones at a mill throughput of 3,800 t/d and   higher. Using a 300% circulating load as a baseline, Krebs’ findings   indicated that the existing arrangement of the cyclones could readily   accommodate the 3,800 t/d scenario through a small increase in the product   grind size and by selecting a larger vortex finder. Alternately, an   additional cyclone can be put into operation to handle the increased feed   rates. When the mill throughput increases to 6,000 t/d, all six cyclones   would be in operation at a much coarser cut-off size of 80% passing   approximately 135 μm. Additional standby cyclone capacity is recommended if   advancing throughput substantially above the 3,800 t/d scenario. 13-31 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE 13.4.2 Gravity Simulations A gravity model was   prepared by FLSmidth in May 2018 based on the 2018 E-GRG test results and the   previous E-GRG test results to simulate the gravity recovery under the   expansion of the Brucejack mill. Three scenarios were simulated: current   operation rate of 2,700 t/d; planned operation rate of 3,800 t/d; and 6,000   t/d at varied primary grind sizes of 80% passing of 90 μm, 110 μm, and 135   μm, respectively. Major conclusions from the modelling are summarized as   follows: Currently, each of the two Kneslon KC-QS40 units installed at the   Brucejack Gold Mine have a recommended feed rate of 225 t/d, which can allow   the two units to treat 100% of the ball mill discharge. The simulated gravity   gold recovery was 59% and 65% at a 70.5% and 80.5% GRG content,   respectively.  When the plant capacity   increases, gold gravity recovery would decrease mainly considering: the   efficiency of the Knelson KC-QS40 will decrease as the feed rate increases,   the coarser primary particle size, and the lower residence time of GRG in the   grinding circuit.  In the 3,800 t/d   scenario, the gold gravity recovery using the two KC-QS40 units may decrease   by 5 to 7%; however, this could be compensated by installing an additional unit   to 3 to 4%. - In the 6,000 t/d scenario, the gold gravity recovery may   significantly drop by 17 to 18% if using the existing two units only. Adding   two more units can limit the gold recovery loss to about 9%. - 13.4.3   Flotation Simulations The existing flotation circuit consists of a series of   rougher and rougher scavenger flotation stage, and a three-stage cleaner   flotation circuit including the first cleaner scavenger stage. The first   cleaner scavenger tailings feeds to the rougher scavenger flotation stage.   Metso Corporation (Metso) and Weir Minerals performed simulations to evaluate   the performance of the existing flotation circuit at a higher plant feed   throughput. Metso concluded that the retention time of the existing cells is   sufficient to handle the 3,800 t/d throughput; however, due to the high froth   carry rate and lip loading predicted from the increased 3,800 t/d throughput,   it would be appropriate for additional cells to be installed for either (or   both) second and third cleaners. The addition of new cells would increase   operational flexibility and facilitate optimization of the cleaner circuit.   Weir Minerals recommended some modifications for slurry handling to improve   overall operation performance for the increased throughput. 13.5 Production   Data 2017 to 2019 The process flowsheet developed for the Brucejack Property   mineralization is a combination of conventional bulk sulphide flotation and   gravity concentration to recover gold and silver into gold doré and   gold-silver bearing flotation concentrates. In May 2017, ore was first   introduced to the mill with a focus on ramping up to designed production   throughput using ore from the low-grade ore stockpiles. The first gold was   poured on June 20, 2017. During commissioning, 8,510 oz Au were produced in   June. On July 1, 2017, Pretivm declared commercial production at the   Brucejack Gold Mine. Table 13-23 lists the production data from July 2017 to   the end of 2019 based on the Pretivm’s reports and news releases. 13-32 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Bruckejack Mill Production   Data 2017–2019(1) Table 13-23: Note:(1)Excluding gold and silver from   pre-commercial production. 13.6 Metallurgical Performance Projection Since   the Brucejack Gold Mine was commissioned, Pretivm has focussed on improving   gold and silver recoveries to the gravity concentrate for doré production and   has been successful in its strategy. In comparison to the 2014 FS (Ireland et   al. 2014) projection for the Valley of the Kings mineralization, although   similar overall gold and silver recovery was observed from the operation, the   gold recovery to the gravity concentrate has significantly improved by   approximately 20% or higher. Because there is no operational data available   for the West Zone, the metallurgical performance is assumed to be the same as   previous projections. 13-33 Time Mill Feed Tonnage (t) Mill Feed Grade (g/t)   Total Recovery (%) Total Daily Au Ag Au Ag Q3 2017 261,262 2,840 10.5 n/a   96.5 n/a Q4 2017 271,501 2,951 8.2 13.8 95.8 80.8 Total Average 2017 532,763   2,895 9.4 13.8 96.2 80.8 Q1 2018 261,443 2,905 9.1 13.0 96.8 85.7 Q2 2018   236,990 2,604 14.9 17.1 97.7 88.3 Q3 2018 240,122 2,610 12.4 14.1 97.4 88.1 Q4   2018 267,048 2,903 11.5 15.8 97.0 85.6 Total Average 2018 1,005,603 2,755   11.9 15.0 97.3 87.0 Q1 2019 295,122 3,279 8.7 13.3 96.8 85.6 Q2 2019 324,171   3,562 8.9 15.6 96.9 83.8 Q3 2019 309,754 3,367 9.1 14.7 97.0 85.5 Q4 2019   373,954 4,065 8.3 14.1 96.8 85.6 Total Average 2019 1,303,001 3,570 8.7 14.5   96.9 85.1 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Pretivm updated the January   2019 resource estimate (Jones et al., 2019) to incorporate new geological and   assay information on the Brucejack Deposit generated through additional   underground drilling, underground mine development, and mine production at   the Brucejack Gold Mine. Details of the resource estimation which form the   basis of the January 2020 Mineral Resource and the January 2020 Mineral   Reserve presented in Section 15.0, are described below. The January 2020   Mineral Resource for the Brucejack Deposit incorporates estimates from the   Valley of the Kings Zone and West Zone. No new information has been collected   from the West Zone since 2012. As such, the West Zone portion of the January   2020 Mineral Resource remains unchanged and is based on the West Zone   resource estimate generated by Snowden in April 2012 (Jones, 2012a; Jones,   2014). The Valley of the Kings Zone portion of the January 2020 resource   estimate has been updated in those areas surrounding the underground workings   informed by new drilling data (Figure 14-1) acquired between January 9, 2019   and September 30, 2019. The December 2013 resource estimate generated by   Snowden (Jones, 2014) and the January 2019 resource estimate generated by   Pretivm (Jones et al., 2019) have been retained for the Valley of the Kings   Zone in those parts of the deposit for which no new data has been obtained   since 2013 and January 2019, respectively. No new information has been   obtained for the Bridge Zone, Gossan Hill Zone, and Shore Zone targets. These   zones are currently not considered part of the high-grade mineral resource on   the Brucejack Project and are therefore not included in the January 2020   Mineral Resource. The Mineral Resource for the Bridge Zone, Gossan Hill Zone,   and Shore Zone targets as reported in September 2012 (Jones, 2012b) is no   longer current. The January 2020 resource estimate for the Brucejack Deposit,   as documented in this report, used data and geologic interpretations provided   by Pretivm. New data used to inform the updated January 2020 resource   estimate included 89,121 m of underground drilling since the January 2019   Mineral Resource (see Section 10.0) and production reconciliation   information. 14.1 Disclosure Mineral Resources were prepared by Ms. Kristin   Chislett, P.Geo. (Resource Geologist, Pretivm) under the direct supervision   of Dr. Craig Morgan, Geo.L, Pr.Sci.Nat. (Corporate Resource Geologist,   Pretivm) and the QP, Mr. Ivor Jones, P.Geo., FAusIMM. Mr. Jones is an   employee of Ivor Jones Pty Ltd (“JonesPL”) and is a QP as defined by NI   43-101 through his experience, membership of a recognized professional   organization, and qualifications. Both Mr. Jones and Ivor Jones Pty Ltd are   independent of Pretivm. Ms. Chislett and Dr. Morgan are employees of Pretivm.   14.2 Known Issues that Materially Affect Mineral Resources At the time of   this report, the QP was not aware of any permitting, legal, title, taxation,   socio-economic, political, or marketing issues that could materially affect   the Mineral Resource presented herein. 14-1 14.0MINERAL RESOURCE ESTIMATES 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-1: Plan View of the   Brucejack Deposit Showing the Location of the West Zone and Valley of the   Kings Zone (VOK) Resource Block Models, and the Defined Update Areas (and   Dates) Source: Pretivm 2020 14-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.3 Modelling Approach The   Brucejack Deposit records a complex magmatic, hydrothermal, and tectonic   geological history associated with an active island arc environment that was   subsequently deformed as a result of destructive plate margin tectonism   (Section 7.0). Whilst geological complexity is partly the reason behind the   gold tenor at Brucejack, it presents numerous challenges to effective   geological and resource modelling of the deposit: Overprinting of an earlier,   low-grade porphyry-associated mineralization system, by a later, co-spatial high-grade   stockwork-hosted epithermal system precludes separation of the two different   systems into separate domains.  The   variable, composite, and broad nature of the epithermal vein stockwork   necessitates modelling corridors of veins, vein breccia, and vein stockwork,   rather than individual veins.  The   presence of statistically significant high-to extreme-gold-grades that are an   integral part of the gold grade distribution in the Valley of the Kings Zone   precludes the exclusive use of traditional linear grade estimation   techniques.  Multiple Indicator Kriging   (MIK) has an advantage over linear estimation techniques in that it can deal   with mixed and inseparable strongly-skewed grade populations characterized by   high coefficients of variation (e.g., Carvalho and Deutsch, 2017). The QP   considers the MIK technique appropriate for use in resource estimation of the   Brucejack Deposit, as the deposit exhibits these characteristics at the   deposit, domain, and local (within-domain) scales. In addition to the use of   MIK, the distribution of high-and extreme-gold-grades during estimation was   further controlled through the application of the split population approach   to grade estimation used previously (Jones, 2014). In this technique, the   low-grade gold and silver variables are estimated through Ordinary Kriging   (OK), the high-grade gold and silver variables are estimated through MIK, and   the probability of high-grade gold and silver occurrence are estimated   through single Indicator Kriging (IK). These estimates are all done at point   scale and recombined to generate final estimates. These estimates are then   reblocked to an appropriate block size. This method considers the mixed,   positively skewed, high coefficient of variation, highly variable, and   nuggety nature of the gold mineralization at Brucejack, as well as the   potential hit-and-miss nature of drilling in such a deposit (Board et al.,   2017). Order relations and volume-variance considerations are an integral   part of this process. The January 2020 resource estimate for the Brucejack   Deposit was prepared in the following steps: Digital data validation  Data preparation  Geological interpretation and domain   modelling  Establishment of block   models  Coding and compositing of assay   intervals  Derivation of kriging   plan  Variogram analysis and selection   of kriging parameters  Grade   interpolation of gold (Au) and silver (Ag) using a mix of OK, IK, and MIK,   followed by reblocking  Validation of   final Au and Ag grade estimates and models    Reconciliation of the January 2020 resource estimate to mill   production  14-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE  Confidence classification of estimates in   accordance with CIM Definition Standards (CIM, 2014)  Deduction for prior mining and additional   non-resource defined material  Mineral   Resource tabulation and documentation. 14.4 Data Provided for Estimation The   January 2020 resource estimate is based upon an updated and expanded drillhole   and assay data set, and updated triangulations, including topography,   lithological wireframes, and mineralized domains. The source and composition   of the assay data set is summarized in Section 14.4.1, and a summary of how   the triangulations are created and approved for use in the resource model is   provided in Section 14.4.2. 14.4.1 Assay Dataset for Grade Estimation   Drillhole and assay data available as of September 30, 2019 were used in the   generation of the January 2020 resource estimate. The GeoSpark SQL drillhole   database, which included the results from the 2019 drilling program, was   provided by Pretivm. Collars, surveys, lithology, assay/geochemical data, and   specific gravity data were exported from the database in .CSV format, and   imported into the Leapfrog Geo, Snowden Supervisor, and Maptek Vulcan mining   software for use in modelling and resource estimation. Several different   industry-standard gold assay techniques have been used at Brucejack (Section   11.0), including conventional fire assay with an AA or gravimetric finish (30   or 50 g charge weights), screen fire assay, and concentrate grade analyses.   Where one sample had gold assay data determined using different analytical   methods, an assay priority was applied. This was based on method and overlimit   values in the following precedence sequence: concentrate grade analyses (for   Au > 10,000 ppm) > 50 g charge fire assay with gravimetric finish   (overlimit Au to 10,000 ppm) > 30 g charge fire assay with gravimetric   finish (overlimit Au to 10,000 ppm) > screen fire assay (1 kg pulp, 50 g   charge; for overlimit Au) > screen fire assay (1 kg pulp, 30 g charge; for   overlimit Au) > 50 g charge fire assay with atomic absorption (AA) finish   (100 ppm Au upper detection limit) > 30 g charge fire assay with AA finish   (10 ppm Au upper detection limit) > Historical Au. Statistical evaluations   of the various techniques between screen fire assays and fire assays with a   gravimetric finish indicated no systematic bias, and therefore, the fire   assays, which comprised a more complete dataset, were used as the primary   assay. Silver results were determined using different analytical methods   (Section 11.0) and were also method-ranked based on overlimit triggers. At   concentrations below 100 ppm, silver is determined by a multi-element ICP   method, which uses a four acid near-total digestion (100 ppm Au upper   detection limit). Above 100 ppm, an ore grade silver analysis is triggered   (upper detection limit 1,500 ppm Ag), followed by a trigger to a 30 g charge   fire assay and gravimetric finish (upper detection limit 10,000 ppm Ag), with   a concentrate grade 30 g charge fire assay with a gravimetric finish   conducted on those samples with silver above 10,000 ppm. There are 4,873   samples in the database that do not have associated silver information. This   represents approximately 1.05% of the total sample database. The Brucejack   Property database as of September 30, 2019 contained 465,435 gold assay data   in 3,917 drillholes, the majority of which (87.6%) were determined using   conventional fire assay with an AA finish. Statistical analyses comparing   conventional fire assay technique by charge sizes for paired data show no   significant differences between assay data types. Similar analyses conducted   on paired data comparing the different overlimit analyses showed no   significant bias or difference between the four overlimit techniques. Limited   historic drilling was conducted in the Valley of the Kings Zone, with the   majority concentrated on the West Zone (Section 10.0; Jones, 2012a). A re-assaying   campaign was conducted on select drillholes from the West Zone by Silver   Standard 14-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE (Jones, 2012a), verifying the   applicability of using this data for modelling and resource estimation. The   Brucejack Project drilling database contains very few unsampled intervals   (few historic drillholes only) and those with no sample recovery. Default   values were not assigned to missing intervals in such cases. Sections 11.0   and 12.0 summarize data quality (QA/QC protocols and findings) and   verification procedures for the Brucejack Project data. 14.4.2 Assay Data   Import Procedure The certified raw assay data files are received by email   directly from the analytical laboratory reporting services. Data are provided   in a specified digital import format (in MS Excel) as well as in a secure PDF   certificate format. Each MS Excel data file is checked for inconsistencies   prior to being imported into the SQL database via the GeoSpark Core MS Access   front end interface (GeoSpark). Laboratory data files are not modified in any   way prior to import. The SQL database is stored on a secure server and data   are backed up nightly. After import, an assay ranking script is run via an   SQL query or stored procedure to provide the final ranked data set. Exports   from the database (to .CSV format) are conducted using a set of saved queries   in the GeoSpark database interface. 14.4.3 Triangulations 14.4.3.1 Topography   Topographic constraint was provided by a digital terrain model (DTM) created   from an aerial light detection and Ranging (LIDAR) survey in the summer of   2014. The survey was flown from a nominal height of 1,800 m above ground at   100 knots flying speed. The data were collected using a Riegel Q1560 laser   scanner owned by Eagle Mapping, with the point data positioned with an   average density of 7–9 points per square metre. Data processing was completed   by Allnorth Consultants before provision to Pretivm. The survey was measured   to have a root mean square error of 0.050 m, and an absolute accuracy of   +/-0.098 m. Conversion of LIDAR to the DTM was completed by Pretivm’s GIS   personnel and reviewed and approved by Pretivm before being imported as a triangulation   into the Maptek Vulcan mining software (v.11.0.4) for use in resource   modelling (Figure 14-2). 14.4.3.2 Lithology Lithological triangulations were   created in the Seequent’s Leapfrog Geo (v.5.0) modelling software with a live   link to Reflex Geoscience’s ioGAS software (v.6.1). The triangulations were   generated based on interpretations from core logs (lithology, structure),   geochemical data, core photos, and surface and underground mapping by a   single experienced geological modeler to ensure consistency. The   triangulations were imported in the Maptek Vulcan mining software and   reviewed, refined, and validated by Pretivm (Figure 14-2). The lithological   triangulations were used to code lithology into the block model for specific   gravity and bulk density modelling. 14.4.3.3 Mineralized Domains Mineralized   domains were prepared by Pretivm using the Leapfrog Geo mining software,   informed by a combination of core logging data (primarily veining and   structure), assay results, core photography, and underground mapping (see   Section 14.5). Mineralized domain triangulations were iteratively updated as   and when new information became available, imported into the Maptek Vulcan   mining software, and reviewed and validated by Pretivm prior to being used   for resource modelling. 14-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.4.3.4 Underground   Development and Production Solids As-built triangulations for underground   mine development (Figure 14-1) and Cavity Monitoring System (CMS) stope void   scans were generated by Pretivm’s mine engineering team at the Brucejack Gold   Mine. The triangulations were imported into the Maptek Vulcan mining   software, reviewed, validated, and used for coding mined out areas for Mineral   Resource depletion and reporting. Blasthole design triangulations were   generated for each stope in the Aegis mine planning software by Pretivm’s   mine engineering team at the mine. A combination of CMS and Blasthole   triangulations were used for reconciliation of the Mineral Resource to the   mill (see Section 14.8.4). Moreover, additional wireframes were diligently   prepared by Pretivm to define zones between and around mined out stopes that   are now considered as either sterilized or non-mineable (see Section   14.10.1). Figure 14-2: Topography and Lithological Wireframes used in the   Generation of the January 2020 Resource Estimate (shown in Maptek’s Vulcan   Mining Software): a) Plan View of Topography Draped with Aerial Photography;   b) Plan View Showing Lithological Model Triangulations and Approximate   Location of Cross Section; c) S-N Cross-Section Along 426525 mE (A-A’).   Source: Pretivm 2020 14-6 a) b) c) 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.5 Geological   Interpretation and Modelling Mineralization in the Valley of the Kings Zone   of the Brucejack Deposit is interpreted as occurring within a series of   mineralized corridors (see Section 7.0). Triangulation solids generated as   part of the November 2012 and December 2013 (Jones, 2012c; Jones, 2014)   resource estimates form the basis for the mineral domain interpretations used   for the January 2020 Mineral Resource update. Mineralization domain   triangulation solids are continuously and iteratively reviewed and refined as   additional geological information (drilling and mapping) is generated. By   design these delineated mineralized domains incorporate and support most of   the sampled high-grade gold occurrences. Plan and cross-sectional views of   the mineralization domain triangulations used in the generation of the   January 2020 resource estimate are presented in Figure 14-3, Figure 14-4, and   Figure 14-5. The QP considers there to be a relatively high degree of   confidence in the mineralized domain interpretations, as he has verified them   in multiple underground exposures at the Brucejack Gold Mine (Section 12.0)   as well as in new drilling information. For the January 2020 resource   estimate, the geological interpretations for the Valley of the Kings Zone   have been updated in the areas mined and drilled during 2019 (see Section   14.6.1). Interpretation of the domains for the January 2020 resource estimate   continue to refine the previous interpretations which were built on the   foundation of the understanding of domains in December 2013. With the   increase in infill drilling at depth, two new domains have been added to the   January 2020 geologic interpretation. A total of 25 mineral domains have been   interpreted for the Valley of the Kings Zone. These 25 domains have been   grouped into 11 larger domains (Bigdom) for modelling purposes, based on   similarities in grade statistics and geology (Table 14-1). Six of the   mineralized Bigdom domains were present in the January 2020 Resource Model   update area: 200, 400, 600, 800, 801, 900 (Figure 14-5; see Section 14.6.1).   Table 14-1: Valley of the Kings Zone Mineralized Domains 14-7 Grouped Domain   (Bigdom) Individual Mineral Domain Code Individual Domain Detail (Domain   Names, in order) 100 10, 20, 30, 40 Galena Hill (GA4, GA3, GA1, GA2) 200 50,   70, 80 Contact-related stockworks (DOM13, DOM38, DOM38B) 300 90 North VOK   (NVOK) 400 130, 140 Contact-related stockwork (DOMP1), VOK/Bridge Zone P1   Contact Zone (P2) 500 110, 120 Eastern Promises VOK (EVOK1, EVOK2) 600 100,   150, 160, 170, 180, 165, 155, 240 Main VOK Domains (ARG, DOM23, DOM8, DOM11,   DOM17, DOM8b, DOM23b, lowerfootwall) 700 190 VOK Lateral (EW LATERAL) 800 200   Cleopatra structure south of 6257972 mN (CLEO) 801 200 Cleopatra structure   north of 6257972 mN (CLEO) 900 210, 230 Domain 20 normal fault – higher grade   (DOM20), Hydrothermal (DOM20 related HBX) -99 -99 Outside of the modelled   mineralized domains 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-3: Plan View of   Mineralized Domain Triangulations Used in the Generation of the January 2020   Mineral Resource Source: Pretivm 2020 Figure 14-4: N-S Cross Section Along   426635 mE of Mineralized Domain Triangulations Used in the Generation of the   January 2020 Mineral Resource Source: Pretivm 2020 14-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-5: Plan View   Showing the Main Grouped Valley of the Kings Zone Mineralized Domains   (Bigdom) Used in the Generation of the January 2020 Mineral Resource Source:   Pretivm 2020 14.6 Data Selection and Preparation 14.6.1 Update Area As noted   earlier, only a portion of the Valley of the Kings Zone has been informed by   new mining and drilling information post the January 2019 resource estimate   (see Figure 14-1). This portion is termed the January 2020 updated model area   (or update area). Pretivm has taken the view that where there is no new   information; the model should not be changed unless it is shown to be clearly   inaccurate. As such, the previous resource estimate (January 2019, which   contains portions of the December 2013 resource) was retained outside the   update area. A model update triangulation solid was generated for the area   informed by new conditioning data (Figure 14-1; Figure 14-6), and the Valley   of the Kings Zone resource estimate was subsequently updated inside this   solid. Drillhole data was coded as either inside the six grouped domains   (Bigdoms) or as a part of the undomained regions within the update area   (Figure 14-1; Figure 14-5). This resulted in a total of 116,195 gold and   115,780 silver assay data in 1,317 drillholes, 555 of which were drilled post   the January 2019 resource estimate. Various exploratory data statistical   analyses were conducted on the selected data using Snowden’s Supervisor   (v.8.11) geostatistical software. 14-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-6: Plan View   Showing Model Update Area Solid (Purple) and Drillholes (White) from the 2019   Infill Drill Campaign Source:Pretivm 2020 14.6.2 Compositing All data was   composited to the dominant sample length of 1.5 m prior to analysis and   estimation. The composited data was then coded according to the relevant   mineralized domain in preparation for modelling. Normally compositing is done   with respect to geological and/or domain boundaries. As the gold   mineralization at Brucejack overprints all lithological units, no geological   control was used during compositing. Furthermore, as stockwork mineralization   domain boundaries tend to be gradational rather than sharp, strict domain   boundary control on composites was not necessary and likely represents false   resolution. Consequently, normal composites of 1.5 m in length were generated   from collar to end of drill string. The composites were then flagged as being   in or out of the mineralization domain, depending on whether the composite   centroid was inside or outside of the domain wireframe. A minimum composite   length of 1.25 m was enforced for resource estimation, removing any short   composite intervals from drillholes terminating in the mineralization domain   wireframe. A total of 100,535 gold and 100,132 silver domain-coded composite   data (62,233 gold and 61,886 silver of the data were inside the domains) were   generated inside the Valley of the Kings Zone within the update area. These   composites were used in the statistical interpretation and generation of the   grade estimates inside the update area. 14-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.6.3 Grade Populations   Infill drilling conducted during the 2019 program confirmed the nature of the   gold and silver grade distributions in the mineralized zones as defined by   previous drilling programs (Figure 14-7). Comparing all drillhole composites   constrained inside mineralized domains in the January 2020 update area, as   generated from the recent 2019 program and the previous drilling programs,   highlights both the similarity in grade distributions for gold and silver   between drilling programs, and the mixed nature of the precious metal   distributions. Log probability plots (cumulative distribution plots) of the   2019 infill drillhole composite data for both gold and silver display a   slightly higher proportion of samples in grades above the median grade to   below the 90th percentile than the pre-2019 drillhole composite data, and a   slightly lower proportion of grades above the 99.9th percentile (Figure   14-7). Essentially this means that whilst the histograms are very similar,   the 2019 data has a slightly lower average grade in the 2019 drill area   because of the lower proportion of high grade in the distribution. The mixed   nature of the precious metal gold distributions, as a function of the   co-spatial nature of the overprinting mineralization systems (Section 7.0;   Section 14.3), is readily evident on the log probability plots (Figure 14-7);   there is a curved inflection zone between 1 and 5 g/t Au on the gold log   probability plot and between 10 and 50 g/t Ag on the silver log probability   plot. Physical separation of the two principle grade distributions into   individual domains is not possible due to the overlapping nature of the two   mineralizing systems. The gold and silver composite datasets were therefore   separated into low-grade gold (<3.5 g/t Au) and low-grade silver (<20   g/t Ag) and high-grade gold (3.5 g/t Au) and high-grade silver (20 g/t Ag)   populations for grade modelling and estimation (see Section 14.7). The   high-grade distributions for gold and silver remained strongly   positively-skewed (coefficients of variation at 28.72 for Au and 8.13 for   Ag). The QP considers the continued use of a non-linear estimator for grade   estimation appropriate based on the similarity in precious metal grade   distributions between the recent (2019) infill drilling and previous drilling   programs in the Valley of the Kings Zone. The use of grade capping (top   cutting) in conjunction with a linear estimator (e.g., OK, inverse distance)   was considered in 2012, but was shown to produce some unrealistic results.   This approach was therefore regarded as inappropriate in the modelling of the   mineralization at Brucejack. There are several reasons:  The challenge in selecting an appropriate   top cut (grade cap). The positive tail of the grade distribution does not   break down (tail decomposition method) until well into the multi-kilogram per   tonne range, and even then, the more data that is collected, the higher the   value before tail decomposition. Using a percentile-based approach results in   an arbitrary and unjustifiable capping of extreme gold grades.  The appropriateness of grade capping.   Consistency of intersecting high-grade (gold and silver) throughout the   Valley of the Kings Zone and the robust positive tail of the high-grade   distributions, indicate that the high-grade intersections are an integral   part of the grade distribution and therefore should be used for grade   estimation. Selecting an arbitrary top cut value results in the artificial   removal of high-grade values that are necessary to preserve the metal in the   grade estimation (and value). Recent experience has shown that even with   these values, the grades are under-estimated with respect to production.  Mixed grade populations that are impossible   to separate. Geologically the low-and high-grade populations are co-spatial   (Section 7.0) and cannot be separated by creating mineral domains.  Block grade trends from linear estimates   are poor representations of input drilling data grade at Brucejack. This is a   function of using a linear estimation technique for a highly skewed grade   dataset characterized by mixed populations. 14-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-7: Log Probability   Plots of a) Gold and b) Silver Composited Data Inside the Valley of the Kings   Zone Mineralization Domains - January 2020 Update Area. Source: Pretivm 2020   Owing to the mixed nature of the grade distribution and the extremely   positively skewed nature of the gold and silver data, a non-linear estimation   technique was deemed necessary to model the Valley of the Kings Zone.   Non-linear techniques like MIK were developed to deal with mixed populations   (e.g., Glacken and Blackney, 1998). MIK was selected because the method   allows modelling of the actual grade distribution using a series of grade   thresholds, as well as a mathematical model for the uppermost grade bin (or   class), precluding the need for an arbitrary grade cap or top-cut. It also   allows the practitioner to consider that samples with different grades have   different levels of continuity, with higher grades having a lot lower   continuity than the lower grades. Additional resolution on grade continuity   across the distribution is provided by modelling of variograms at each grade   threshold. 14-12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.6.4 Summary Statistics   Histograms for composited data inside the Valley of the Kings Zone   mineralized domains indicate that the gold and silver populations are   extremely positively-skewed with a high coefficient of variation (CV) and low   mean grades (see Figure 14-8). Summary statistics for the domain-coded   composited drillhole data for the 2019 updated area are presented in Table   14-2. Ranking the data by gold grade shows that 88% of the metal in the   Valley of the Kings Zone mineralization domain is represented by   approximately 5% of the sample data, with 80% being represented by the top 1%   of the sample data. Similarly, 50% of silver metal in mineralized domains is   represented by approximately 15% of the sample data, and approximately 20% represented   by the top 1% of the sample data. These statistics highlight that significant   value in the Valley of the Kings Zone is associated with uppermost part of   the relevant grade histogram. The ubiquitous presence of elevated gold   intersections throughout the Valley of the Kings Zone drilling and   underground workings (visible gold) demonstrates that the grades are not   anomalous, and that it is important that these high grade samples are   considered in the grade estimation process. The strong positive skewness,   high CV, and low mean grades of the gold and silver grade distributions   indicate that the mineralized domains contain a significant level of internal   low-grade. These features are in keeping with the geological interpretation   (see Section 7.0) that a variable and disjunctive, high-grade, epithermal   vein stockwork system was superimposed on a lower grade, porphyry-associated,   phyllic alteration system in such a way that the two systems are physically   inseparable for modelling purposes. Figure 14-8: Log-Normal Histogram Plot of   a) Gold and b) Silver Composited Data Inside the 2019 Updated Area   Mineralization Domains. Source: Pretivm 14-13 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 14-2: Summary   Statistics of Gold and Silver Composited Data by Grouped Domain in January   2020 Model Updated Area Note:CV – coefficient of variation 14.7 Estimation   14.7.1 Methodology Grade estimates were generated into the Bigdom domains   inside the update area using the domain-coded composite data. The overall   approach is similar to that used in the generation of the December 2013, July   2016, and January 2019 resource estimates in that separate high-grade,   low-grade, and probability of high-grade estimates are generated for each   block using the split population, non-linear estimation approach detailed in   Jones (2014). Additional resolution provided by infill drilling and the   evaluation of that data inside the January 2020 update area has indicated   that 3.5 g/t Au and 20 g/t Ag best distinguish between low-and high-grade   populations for these two grade variables. The grade estimation workflow used   to generate the January 2020 resource estimate is detailed below:  A model was prepared at the parent block   size (5 mE by 5 mN by 5 mZ) and coded by lithology and mineralized domain   (individual and grouped) as the parent model.    A separate block model was set up with a 2.5 mE by 2.5 mN by 2.5 mZ   block size and coded by mineralized domain (individual and grouped) for grade   estimation. 14-14 Statistic Bigdom 200 400 600 800/801 900 Au (g/t) Ag (g/t)   Au (g/t) Ag (g/t) Au (g/t) Ag (g/t) Au (g/t) Ag (g/t) Au (g/t) Ag (g/t)   Number of samples 8,025 8,025 8,863 8,856 41,957 41,662 125 125 3,263 3,218   Minimum grade (g/t) 0 0.25 0 0.25 0 0.25 0.02 0.25 0.01 0.25 Mean grade (g/t)   1.82 6.70 2.18 4.62 3.86 5.87 3.02 8.03 4.45 8.2 Maximum grade (g/t) 1,050   503 2,730 993 11,313 5,804 164 134 1197 455 Standard deviation 22.33 20.08   37.49 17.22 98.36 50.45 15.3 19.21 42.23 22.81 Variance 498 403 1,406 296   9,675 2,545 234 369 1,783 520 CV 12.26 3.00 17.22 3.72 25.51 8.59 5.06 2.39   9.49 2.78 High grade threshold (g/t) (HGT) 3.5 20.0 3.5 20.0 3.5 20.0 3.5   20.0 3.5 20.0 Percent  HGT 2.9% 4.6%   3.5% 2.6% 3.4% 3.2% 8.0% 7.2% 5.7% 7.2% Mean grade above High grade threshold   (g/t) 47.1 61.8 47.7 58.5 98.9 85.3 31.2 58.7 66.5 61.2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE  Statistical analysis was conducted on the   gold and silver grade distributions using Snowden’s Supervisor geostatistical   software. The following was conducted: - Discretization of the   high-grade gold (3.5 g/t) and silver (20 g/t) distributions using appropriate   decluster-weighted grade thresholds - Lower and upper tail analysis of   the high-grade gold and silver distributions and selection of appropriate   mathematical models for these - Determination of the appropriate   percentile for the threshold of the top class in the high-grade indicator   thresholds using the decluster-weighted gold and silver data -   Univariate statistical analysis of the low-grade population (<3.5 g/t Au,   <20 g/t Ag).  Three-dimensional   spatial analysis (variography).    Search, estimation, and variogram parameter sensitivity analyses.  Grade interpolation of each grade variable   (i.e., low-grade, high-grade, probability of high-grade for each of gold and   silver) separately into 2.5 m by 2.5 m by 2.5 m blocks using: - OK for   grade of the low-grade mineralization (<3.5 g/t Au, <20 g/t Ag) -   MIK for grade of the high-grade mineralization (3.5 g/t Au and 20 g/t Ag)   - IK of the mineralisation indicator for the proportion of high-grade   (i.e., probability of Au 3.5 g/t and Ag 20 g/t).  The 2.5 mE by 2.5 mN by 2.5 mZ estimates   were post-processed to provide total gold and silver grades for each block   (e-type estimates). The grade of the mineralization above 3.50 g/t Au and the   grade of the mineralization below 3.50 g/t Au in the block were each   multiplied by the relevant proportions to calculate the final grade estimate   for each block. The same process was applied to the silver grades. Grade   estimates were then re-blocked to 5 mE by 5 mN by 5 mZ blocks to provide an   appropriate volume estimate.  The   individual estimates were checked/validated against the relevant input   composite data (see Section 14.8).  The   validated block model inside the update area was then added to the January   2019 block model (Jones et al., 2019) to generate the full Valley of the   Kings Zone resource model, as blocks in the January 2019 update area that   have no recent (2019) infill drilling within approximately 40 m remained the   same. The majority of blocks outside the January 2019 update area and January   2020 update area are the same as those generated as part of the December 2013   resource estimate (Jones, 2014).  The   full Valley of the Kings Zone resource model was then depleted against all   mined-out solids and any additional volumes deemed to not satisfy the   definition of a resource. This was then followed by a regularization up to 10   mE by 10 mN by 10 mZ block size for the entire model to account for the   degree of selectivity that the QP believes is possible in the well-drilled   volumes. 14-15 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.7.2 Parameter Optimization   Estimation parameter optimization through iterative model testing was   conducted on several updated versions of the input drillhole database ahead   of the September 30, 2019 database cut-off date (see Section 14.4.1).   Iterative test work conducted ahead of final parameter selection   included:  Tail modelling (upper tail   models). Grade capping yielded unsatisfactory results (see Section 14.6.3 for   a discussion on top cutting). All models that utilized grade capping significantly   under-called actual production. The 95th percentile was selected as the   uppermost percentile to model the high-grade gold and silver populations as   it facilitated the most representative mathematical modelling of the upper   class. Given the gold and silver populations are extremely positively-skewed,   the upper 5th percentile has a large effect on the estimation. The upper   tails model chosen was based on matching the majority of the curve where   there was sufficient data. In domains with minor amounts of data, the   parameters of Bigdom 600 were applied.    Number of samples. Testing of the number of samples used in the   high-grade and probability estimates indicates that the number of samples has   more influence than the search ellipse. The conclusion of this work was that   the use of a large number of samples resulted in extensive smearing of the   highest grades. This model, which focused on areas drilled with more drill   density than other parts of the model, was intended to be used for dual   purposes (long and short term), and local accuracy was therefore important.   The decision to limit the number of samples used in the estimation process to   six was therefore made to try and maximize the local accuracy of the grade   estimates, particularly now that more drill information is available in the   Bigdom domains 100 to 500.  Number of   search passes. Adding in a second search pass in the low-grade estimation   allowed the estimate to still validate well on a local scale but yields   results in areas further away from data.    Parent block size. There is a concern that a 5 mE by 5 mN by 5 mZ   parent block size for grade estimation was too small to give an accurate   estimate for reporting purposes, and therefore a parent block size of 10 mE   by 10 mN by 10 mZ was investigated. The smaller block size was favoured for   estimation due to the better definition available for detailed mine design.   Final 5 mE by 5 mN by 5 mZ block were nevertheless regularized up to 10 mE by   10 mN by 10 mZ blocks post estimation and post processing for mineral   resource reporting purposes. 14.7.3 Variography Three-dimensional spatial   analysis was conducted on composite data using Snowden’s Supervisor   geostatistical software. Experimental variograms were generated for each of   the grade estimation variables in the following way:  Indicator semi-variograms were generated at   each grade threshold discretizing the high-grade gold (3.5 g/t Au) and   high-grade silver (20 g/t Ag) distributions by grouped domain (Section   14.7.3.1).  Indicator semi-variograms   were generated for thresholds set at the gold and silver delimiters (3.5 g/t   Au; 20 g/t Ag) using full gold and silver grade distributions (Section   14.7.3.2).  Traditional semi-variograms   were generated for low-grade gold (<3.5 g/t Au) and low-grade silver   (<20 g/t Ag) (Section 14.7.3.3). 14.7.3.1 High-grade Population Indicator   Variograms Indicator variograms for the high-grade gold and silver   populations were generated and modelled using domain-coded composite data for   each of the Bigdom domains. Variogram orientations were primarily defined   using dominant domain orientations (which, in turn, were based on dominant   mineralized vein orientations). High-grade 14-16 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE gold and silver grade   distributions were discretized into 11 thresholds (20, 30, 40, 50, 60, 70,   75, 80, 85, 90, and 95th percentile; Table 14-3). Experimental variograms   were generated and modelled at each grade threshold for both gold and silver   by Bigdom. Variogram models for silver were modelled independently from gold   by percentile threshold and Bigdom. Example indicator variogram parameters   generated for the largest grouped domain (Bigdom 600) are presented in Table   14-4. Note for all tables presenting variogram parameters that D1, D2, and D3   are the major, semi-major, and minor axes of the continuity ellipse and that   xxyyy means a dip of xx on a bearing of yyy. Table 14-3: Thresholds   Discretizing High-grade Distribution by Bigdom Table 14-4: Indicator Variogram   Parameters for High-grade Gold in Bigdom 600 table continues... 14-17 Cut-off   Grade Au g/t (Percentile) Orientation Nugget Structure 1 Structure 2 Sill   Range (m) Sill Range (m) 4.63 (20) D1: -70200 0.30 0.55 8 0.15 125 D2: 00290   8 125 D3: -20020 6 85 5.57 (30) D1: -70200 0.30 0.55 7 0.15 85 D2: 00290 7 80   D3: -20020 6 80 Threshold Percentile Au (g/t) Ag (g/t) Bigdom 200 Bigdom 400   Bigdom 600 Bigdom 800/801 Bigdom 900 Bigdom 200 Bigdom 400 Bigdom 600 Bigdom   800/801 Bigdom 900 20 4.666 4.44 4.633 4.943 4.677 23.13 24.81 23.83 22.72   24.09 30 5.526 5.181 5.569 6.259 5.611 25.82 27.31 26.49 26.21 27.07 40 6.828   6.283 7.033 8.634 6.51 28.6 31.08 29.7 31.88 30.7 50 8.751 7.758 9.496 13.87   8.367 32.32 35.57 33.9 37.25 35.87 60 12.4 10.63 13.7 19.36 11.42 38.52 41.69   41.01 43.44 44.5 70 18.35 16.08 23.46 30.36 18.95 47.42 56.98 51.73 52.24   55.07 75 23.6 19.47 32.53 42.11 26.94 55.43 64.26 59.68 72.64 63.62 80 32.81   24.29 48.17 63.68 37.78 66.91 71.48 71.22 96.62 78.91 85 51.4 43.06 77.26   117.3 60.71 80.43 82.15 93.48 119.4 98.95 90 101.9 73.94 142.1 162.6 107.8   104.9 115.3 134.1 203.3 135.3 95 188.9 152.4 325 615.4 234.4 192.5 213.4 268   391.5 221.7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14-18 Cut-off Grade Au g/t   (Percentile) Orientation Nugget Structure 1 Structure 2 Sill Range (m) Sill   Range (m) 7.03 (40) D1: -70200 0.30 0.55 7 0.15 80 D2: 00290 7 80 D3: -20020   5 80 9.50 (50) D1: -70200 0.35 0.50 7 0.15 75 D2: 00290 7 80 D3: -20020 5 25   13.7 (60) D1: -70200 0.35 0.50 5 0.15 45 D2: 00290 4 55 D3: -20020 4 20 23.46   (70) D1: -70200 0.35 0.50 5 0.15 35 D2: 00290 4 45 D3: -20020 4 10 32.53 (75)   D1: -70200 0.35 0.50 4 0.15 30 D2: 00290 4 30 D3: -20020 4 8 48.17 (80) D1:   -70200 0.40 0.45 3 0.15 30 D2: 00290 3 30 D3: -20020 4 8 77.26 (85) D1:   -70200 0.40 0.45 3 0.15 30 D2: 00290 3 30 D3: -20020 3 8 142.1 (90) D1:   -70200 0.40 0.45 2 0.15 30 D2: 00290 2 30 D3: -20020 2 8 325 (95) D1: -70200   0.40 0.45 2 0.15 30 D2: 00290 2 30 D3: -20020 2 8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.7.3.2 Probability of   High-grade Variograms Variogram models generated for the probability of   high-grade gold and silver were generated using all drillhole composite data   inside the update area. Variogram model parameters for the probability of   high-grade are presented in Table 14-5 and Table 14-6. Table 14-5: Variogram   Model for the Probability of High-grade Gold Indicator Variable at 3.5 g/t Au   Note: Variograms modelled to experimental sill. 14-19 Bigdom Orientation Axis   Nugget Structure 1 Structure 2 Structure 3 Sill Range (m) Sill Range (m) Sill   Range (m) 200 D1: -90000 Major 0.40 0.38 5 0.21 12 0.09 54 D2: 00270   Semi-major 1 4 60 D3: 00000 Minor 1 4 60 400 D1: -70200 Major 0.40 0.38 5   0.21 12 0.09 54 D2: 00290 Semi-major 1 4 60 D3: -20020 Minor 1 4 60 600 D1:   -70200 Major 0.40 0.38 5 0.21 12 0.09 54 D2: 00290 Semi-major 1 4 60 D3:   -20020 Minor 1 4 60 800 D1: -90000 Major 0.50 0.46 24 0.18 36 - - D2: 00350   Semi-major 13 14 - D3: 00080 Minor 5 22 - 801 D1: -90000 Major 0.50 0.46 24   0.18 36 - D2: 00025 Semi-major 13 14 - D3: 00115 Minor 5 22 - 900 D1: -65210   Major 0.50 0.32 2 0.18 55 - - D2: 00300 Semi-major 2 25 - D3: -25030 Minor 2   7 - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 14-6: Variogram Model   for the Probability of High-grade Silver Indicator Variable at 20 g/t Ag   Note: Variograms modelled to experimental sill. 14.7.3.3 Low grade Population   Variograms Traditional semi-variograms for low grade gold and silver were   generated and modelled using all composite data. There was no need to   subdivide the low grade precious metal mineralization into individual or   Bigdom domains as the mineralization is ubiquitous and statistically similar   throughout the phyllically altered rocks in the update area. Variogram   parameters generated for low grade gold and silver populations are presented   in Table 14-7 and Table 14-8. 14-20 Bigdom Orientation Axis Nugget Structure   1 Structure 2 Structure 3 Sill Range (m) Sill Range (m) Sill Range (m) 200   D1: -90000 Major 0.40 0.45 5 0.09 44 0.15 60 D2: 00270 Semi-major 5 40 60 D3:   00000 Minor 5 17 60 400 D1: -70200 Major 0.40 0.45 5 0.09 44 0.15 60 D2:   00290 Semi-major 5 40 60 D3: -20020 Minor 5 17 60 600 D1: -70200 Major 0.40   0.45 5 0.09 44 0.15 60 D2: 00290 Semi-major 5 40 60 D3: -20020 Minor 5 17 60   800 D1: -90000 Major 0.45 0.51 20 0.18 36 - D2: 00350 Semi-major 13 14 - D3:   00080 Minor 4 12 - 801 D1: -90000 Major 0.45 0.51 20 0.18 36 - D2: 00025   Semi-major 13 14 - D3: 00115 Minor 4 12 - 900 D1: -65210 Major 0.4 0.38 4 0.1   5 0.12 34 D2: 00300 Semi-major 4 14 21 D3: -25030 Minor 3 4 5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 14-7: Variogram Model   for Low-grade Gold Mineralization Table 14-8: Variogram Model for Low-grade   Silver Mineralization 14.7.4 Search Parameters Search parameters used in the   estimation of the January 2020 resource estimate were based on iterative   modelling, and are presented in Table 14-9 and Table 14-10. Search parameters   were optimized to reduce excessive smearing while allowing sufficient data to   be used to create a representative estimate. Whilst the maximum number of   samples used in estimation appears low, it was noted that using more samples   created excessive grade smearing, with increasing under-calling of high-grade   areas, and over-calling of seemingly low-grade areas. Table 14-9: Search   Parameters for High-grade and Probability of High-grade Variables for Gold   and Silver by Bigdom Inside the Update Area table continues... 14-21 Bigdom   Orientation Estimation Variable First Search Pass Second Search Pass Search   Ellipse (m) No. Samples (Min,Max) Max. No. Samples per Drillhole Search   Ellipse (m) No. Samples (Min,Max) Max. No. Samples per Drillhole 200 D1:   -90000 D2: 00270 D3: 00000 High grade 50x30x20 2,6 - 70x45x30 2,6 -   Probability 35x35x15 12,16 8 70x70x30 2,16 8 400 D1: -70200 D2: 00290 D3:   -20020 High grade 50x30x20 2,6 - 70x45x30 2,6 - Probability 35x35x15 12,16 8   70x70x30 2,16 8 Indicator Orientation Nugget Structure 1 Structure 2 Sill   Range (m) Sill Range (m) <20 g/t Ag D1: -70205 0.15 0.20 3 0.45 170 D2:   00295 1 150 D3: -20025 4 60 Indicator Orientation Nugget Structure 1   Structure 2 Sill Range (m) Sill Range (m) <3.50 g/t Au D1: -70205 0.15   0.35 7 0.5 40 D2: 00295 7 30 D3: -20025 4 20 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Note: Gold and silver search   parameters are identical. The search strategy attempts to maintain the   variability of the local average grade and minimize grade smearing. Search ellipse   orientation was defined by trends in the major mineralized structures within   the domains. Table 14-10: Search Parameters for Low grade Gold and Silver   Inside the Update Area Note: Gold and silver search parameters are identical.   14.7.5 Upper Tail Modelling of High Grade Population in MIK Estimation   Estimation of the upper bin (top class) for mixed positively-skewed   distributions like that of Brucejack is problematic as it represents the   majority of the metal reported in the model. The use of median and mean   grades to represent the grade of the top class was not considered suitable as   these statistics could lead to gold and silver grade over-estimation due to   the shape of the upper tails of the high-grade gold and silver distributions   (see Figure 14-9). The grade of the top class was therefore modelled using   either a hyperbolic or a power model, depending on which best fit the upper   tail of the high-grade gold and silver distributions for each of the Bigdom   domains (Table 14-11). 14-22 Orientation First Search Pass Second Search Pass   Search Ellipse (m) No. Samples (Min,Max) Max. No. Samples per Drillhole   Search Ellipse (m) No. Samples (Min,Max) Max. No. Samples per Drillhole D1:   -70205 D2: 00295 D3: -20025 50x50x20 8,20 6 150x150x60 8,20 6 Bigdom Orientation   Estimation Variable First Search Pass Second Search Pass Search Ellipse (m)   No. Samples (Min,Max) Max. No. Samples per Drillhole Search Ellipse (m) No.   Samples (Min,Max) Max. No. Samples per Drillhole 600 D1: -70200 D2: 00290 D3:   -20020 High grade 50x30x20 2,6 - 70x45x30 2,6 - Probability 35x35x15 12,16 8   70x70x30 2,16 8 800 D1: -90000 D2: 00025 D3: 00115 High grade 25x25x10 2,6 -   50x50x20 2,6 - Probability 35x35x15 12,16 8 70x70x30x 2,16 8 801 D1: -90000   D2: 00025 D3: 00115 High grade 25x25x10 2,6 - 50x50x20 2,6 - Probability   35x35x15 12,16 8 70x70x30 2,16 8 900 D1: -65210 D2: 00300 D3: -25030 High   grade 40x30x15 2,6 - 80x60x30 2,6 - Probability 35x35x15 12,16 8 70x70x30   2,16 8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-9: Example of   Modelling the Upper Tail of the a) High-Grade Gold and b) High-Grade Silver   Populations Using a Hyperbolic Model. Data Shown for Bigdom 600. Source:   Pretivm Table 14-11: Mathematical Model Parameters for the Top MIK Threshold   for Each Bigdom 14.7.6 Specific Gravity and Bulk Density A total of 3,438   specific gravity and 543 bulk density measurements have been collected from   the Valley of the Kings Zone of the Brucejack Deposit. A specific gravity and   bulk density campaign was undertaken in the 2019 drill program to collect   samples in previously sparsely drilled lithologies. A total of 717 new   specific gravity and 133 new bulk density measurements were added into the   Valley of the Kings Zone. Specific gravity and bulk density data were treated   in a similar way to Jones (2014), with some refinements, including the use of   updated lithology wireframes. A total of 1,460 specific gravity and 410 bulk   density data were relevant for the January 2020 resource 14-23 Bigdom Model   Type Model Parameter Maximum Grade Au Ag Au Ag Au (g/t) Ag (g/t) 200   Hyperbolic Hyperbolic 1.25 2.90 5,850 887 400 Hyperbolic Hyperbolic 1.50 1.90   2,730 1,140 600 Hyperbolic Hyperbolic 1.20 1.55 12,375 7,105 800/801   Hyperbolic Power 1.20 1.50 14,746 9,934 900 Hyperbolic Hyperbolic 1.35 2.05   3,568 1,885 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE estimate, including the full   area of the January 2019 update box. Conversion factors between specific   gravity and bulk density were determined by lithology (Table 14-12) and used   in the block model. Table 14-12: Specific Gravity Values and Bulk Density   Conversion Factors for Resource Modelling in the Update Area Notes: Bulk   Density = Specific Gravity*Conversion Factor (1)Factor generated using all   data due to limited bulk density data for the porphyry units. (2)Lithologies   with no measured specific gravity have been set to the default value of 2.82.   The P1 and P2 lithological units are not present in the update area and have   limited representation in the full Valley of the Kings Zone model. 14.7.7   Other Variables Block estimates were generated for As, S, and Ca as part of   the January 2020 resource estimate. As and S are deleterious elements   reporting to the flotation concentrate. Ca and S are used in the   determination of the Neutralization Potential Ratio (NPR) of the mill feed in   order to optimize tailings geochemistry (minimize acid generating potential)   for disposal in the lake or as part of paste backfill, and do not constrain   the Mineral Resource. All drillhole data were composited to 1.5 m length with   no breaks for lithological or mineralization boundaries; however, only those   inside the January 2020 update box were flagged for use in estimation.   Following exploratory data analysis, variography, and parameter selection,   the As, S, and Ca variables were estimated directly into the parent 5 mE by 5   mN by 5 mZ block model using OK. Model validation was carried out by   comparing global statistics between composited data and estimated grades. Additionally,   local accuracy was validated by comparing sectional grades using slice plots.   Both validation techniques showed good reproduction of input data. 14.8 Model   Validation Validation of the final model represents only one part of the   overall validation process conducted in the generation of the January 2020   resource estimate. Detailed validation was conducted at each step of the   modelling process, from data collection to resource reporting. Model   validation checks included checks on the physical generation of the model   (e.g., correct block coding, block model regularization, and addition   processes), as well as checks on 14-24 Rock Type Lithology No. of Samples   Average Specific Gravity Bulk Density Conversion Factor P2 Two feldspar   latite porphyritic flow - 2.82(1)(2) 0.9526 Silcap Silicified conglomerate 67   2.75 0.9926 Andx Latite fragmental 322 2.87 0.9708 Trans Transitional unit -   2.821(1)(2) 0.9616 Cong Polylithic conglomerate 205 2.84 0.9717 VSF   Volcano-sedimentary facies rocks 756 2.79 0.9921 Arg Argillite 15 2.77 0.9595   P1BZ Bridge Zone latite porphyry 90 2.79 0.9941 P1OF Office latite porphyry 5   2.79 1.1029 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE block model grade estimate   data. In the final model, grade estimates were compared against input   drillhole data to assess how well the average of modelled grades match the   average of the input data grades, and how well the model honours grade trends   in the input data. Grade validation checks included:  Statistical checks of final grade,   low-grade, high-grade, and probability estimates against input data by   domain  Swath plots for each of the   estimated variables (final grade, low-grade, high-grade, and probability) by   domain  Visual checks comparing model   grades against input drillhole data in plan, on section, and in three   dimensions  Visual checks of zones of   estimated mineralization against actual underground exposures  Production checks. The presence of high-and   extreme-gold-grades in the stockwork mineralization at Brucejack makes for   challenging model validation. The high-to extreme-grades distort the local   statistics on the composite grades, yet they are not anomalies in the grade   distribution (see Section 14.6). High-grade mineralization is often present   in the mineralization in a given volume but not represented in samples   collected from that volume (evidenced both in underground workings,   processing of the bulk sample, and daily mill reporting). Alternatively, if a   piece of gold is intersected in a sample, there is the possibility that the   sample is not representative of the surrounding rock because of the   infrequent but significant nature of its occurrence. This results in   challenges with respect to the accuracy of local grade estimates. 14.8.1   Statistical Checks – Final Gold and Silver Grade Estimates Final gold and   silver grade estimates in the resource model were compared against the   declustered input domain-coded drillhole composite data (see Table 14-13).   Overall, the global average grade estimates for gold and silver honour the   grades from the input drillhole composite data, and the input drillhole data   is considered globally unbiased. The variable differences between the   estimated and input grades reflect variable degrees of clustering of the   input data by domain: the estimated and input grades are close where the   clustering effect is low. Table 14-13: Global Comparison of Mean Estimated   and Input Composite Grade Data for Gold and Silver by BIGDOM Note:   Comparisons were restricted to the 2019 update area. 14-25 Statistic Bigdom   200 400 600 800/801 900 Au Ag Au Ag Au Ag Au Ag Au Ag Number of samples 8,025   8,025 8,863 8,856 41,957 41,662 125 125 3,263 3,218 Mean grade – Composite   (g/t) 1.82 6.7 2.18 4.62 3.86 5.87 3.02 8.03 4.45 8.2 Mean grade – Estimate   (g/t) 2.12 5.51 1.45 3.89 2.90 5.35 4.97 8.40 4.97 8.38 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.8.2 Grade Trend Plots   Trend plots (or swath plots) comparing model estimates and decluster-weighted   input drillhole composite data by Easting, Northing, and Elevation were   generated for each individual parameter (e.g., low-grade, high-grade, proportion   above the grade population delimiter, and the final grade) as a primary   validation tool. This was done to assess how well grade trends in the input   data were being modelled in the resource estimate, a feature not apparent in   univariate summary statistics. Difficulties in manually matching the   declustering that occurs as part of the estimation process (see Section   14.8.1) necessitated the use of a spatially reasonable cell size to   approximate declustering for comparative purposes. Example trend plots (for Bigdom   600) are presented in Figure 14-10 to Figure 14-15. Estimates of the   individual variables (low-grade, high-grade, and proportion of high-grade)   showed a relatively good comparison to their respective input composite data   for each domain. These estimates were therefore considered robust and   suitable for being recombined to form the final gold and silver grade   estimates (see Section 14.7.1). Recombined final grade estimates displayed   smoother (less spikey) trend lines than those generated for the input   drilling composite data, for all three directions. This is due to the   volume-variance effect evident between drillhole composites (point data) and   block estimates. Block grade estimate data display similar trends to the   input drillhole composite data, for all three directions, with a tendency   towards being slightly lower grade than the input data (i.e., the trendline   is not the exact mean of the input data). This is a function of the   decluster-weighting of the input drillhole composite data and difficulties   associated with it, as noted above. Grade trends in the input drillhole   composite data are best honoured where the conditioning data is spaced at   between 10 and 15 m centres. In poorly informed areas (e.g., north of 6258080   mN and below ~1100 m elevation, the plots show relatively poor correlation   between model estimates and input data. Similar observations are developed in   the silver trend plots. Figure 14-10: Example Gold Grade Trend Plots by   Easting for Bigdom 600 Source: Pretivm 2020 14-26 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-11: Example Gold   Grade Trend Plots by Northing for Bigdom 600 Source: Pretivm 2020 Figure   14-12: Example Gold Grade Trend Plots by Elevation for Bigdom 600 Source:   Pretivm 2020 14-27 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-13: Example Silver   Grade Trend Plots by Easting for Bigdom 600 Source: Pretivm 2020 Figure   14-14: Example Silver Grade Trend Plots by Northing for Bigdom 600 Source:   Pretivm 14-28 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-15: Example Silver   Grade Trend Plots by Elevation for Bigdom 600 Source: Pretivm 2020 14.8.3   Visual Validation Visual validation of the block grade estimates for the   January 2020 resource estimate was conducted in the update area to assess the   validity of grade trends, identify potential grade blow-out zones, identify   zones of high, medium, and low confidence in the block grade estimates, and   to assess the edge of the modelled mineralized zone relative to actual   epithermal veining. Visual model validation was conducted by comparing block   grade estimates against input drillhole composites in the Maptek Vulcan   software and to geology in the underground mine exposures. Block model grade   estimates were compared against input drillhole composite grades in three   dimensions (model rotation and iterative zoom-in, zoom-out), as well as on a   section-by-section basis (along Easting, Northing, and in plan view).   Incremental slicing tools in the Vulcan mining software, with variable   viewing windows, were used for this check. Example section and plan views are   shown in Figure 14-16 and Figure 14-17. Overall the visual validation check   indicated that high-grade blocks were being informed by high-and   extreme-grade mineralization, and that in areas of higher infill drilling   density, high-grade blocks were reasonably constrained by lower grade   mineralization (i.e., no blow-outs). Mineralization trends in the input   composite data appear to be reasonably represented in the block grade   estimates. Underground geological exposures confirmed the presence of   epithermal veining where mineralized blocks were estimated, including the   presence of visible electrum in places. Estimates in mineralized domains   showed reasonable boundary resolution relative to the edges of the   mineralized epithermal vein system exposed in the underground workings,   particularly in areas informed by tightly-spaced drilling. 14-29 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Low-and medium-grade   composite data are well represented by the model, although there are numerous   places where high-and extreme-grades are suppressed by lower grade composite   data, with no significant expression in the block grade estimates. This is   due to the low estimate of the proportion of high-grade in areas dominated by   lower grade intersections. Given the hit-and-miss nature of the high-grade   data in the drilling (see Section 10.0) and the heterogeneous nature of the   gold mineralization in the Valley of the Kings Zone (see Section 7.0), it is   likely that the block model estimate is relatively conservative in such   areas. Figure 14-16: Plan View of the 1180 m Level Showing Block Grade   Estimates and Input Drillhole Composite Data Colour Coded by Gold Grade Note:   Source: Viewing window is ±5 m; drillhole composites shown as ‘+’ markers.   Pretivm 2020 14-30 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-17: N-S Cross   Section Along 426300 E Showing Block Grade Estimates and Input Drillhole   Composite Data Coloured by Gold Grade Note: Source: Viewing window is ±30 m;   drillhole composites shown as ‘+’ markers Pretivm 2020 14.8.4 Reconciliation   of the Resource Model with 2019 Production Additional validation checks were   conducted by reconciling the January 2020 resource model to the mill grade   and recovered ounces for 2019 production (see Table 14-14 and Figure 14-18).   The reconciliation presented in this section compares the resource model to   mill production prior to application of mill recovery factors. Two   reconciliation approaches were used as a test to enhance confidence in the   validity of the resource model: Model to mill reconciliation in as-mined   shapes to provide a single annual production reconciliation  Model to mill reconciliation using material   movement tracking data to provide a time-based reconciliation.  As-mined shapes are wireframe solids and   included those from the Maptek Aegis mining software blast shapes for stope   rings sent as ore or waste, surveyed underground development rounds sent as   ore or waste, and stope CMS scans. Assayed surface stockpile material sent to   the mill was included, although this represented a very small portion   (<1%) of the material mined. Aegis blast shapes for a given stope were   compared against final surveyed CMS of stopes and found to be reasonably representative   of the mined volume. Material movement tracking was conducted by truck   counting on a per shift basis, with an applied mass factor per truck and LHD   (scoop) bucket. These factors were reconciled monthly against actual crusher   weightometer data. Challenges associated with material movement tracking   included variable residency times of mucked ore in remuck bays on mining   levels, as well as in crusher feed remuck bays, and ore from different stopes   being blended together in variable quantities as a function of mining   exigencies. The nature of material movement and stope blending in the   Brucejack Mine therefore precluded exact reconciliation by source (i.e., on a   stope-by-stope basis). Material movement tracking data did, however,   facilitate approximation of model to mill reconciliation through the year for   trend analysis. 14-31 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 14-14: January 2020   Model to 2019 Mill Gold Production Reconciliation Note: Silver grades are not   reported in daily figures by the mill. Results of both reconciliation   approaches show that the predicted grades and contained ounces in the January   2020 model are within 10% of the raw mill production data for 2019. This is   well within acceptable limits for the mining of heterogeneous nuggety gold   deposits on an annual production basis. Local over-and under-estimation of   grade for short-term mining volumes as noted in the reconciliation figures   (Figure 14-18) have averaged out over the annual production volume indicating   an unbiased model. Large differences in ounces from the mill, as noted in   Figure 14-18, usually correspond to production in areas with a wider   drillhole spacing. 14-32 Tonnage (‘000s t) Au (g/t) Contained Au (‘000s Oz)   Total Mined Wireframe Approach 1,356 8.09 353 Total Mined Materials Movement   Tracking Approach 1,385 7.95 354 Mill Data 1,303 8.73 366 Percentage   Difference Mined to Mill Wireframe Approach +4.0% -7.3% -3.5% Percentage   Difference Mined to Mill Materials Movement Tracking +6.3% -8.9% -3.1% 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-18: Ounces   Normalized to Mill Production with Corresponding Drillhole Spacing Plot for   the January 2020 Model Note:2019 production data is shown pre-mill recovery;   percent difference of ounces with respect to the mill for the December 2019   resource model is based on material movement tracking data to approximate   time-based reconciliation. Difficulties inherent in truck tracking preclude   exact stope-by-stope reconciliation due to stope blending and variable   underground muck residency times. Source: Pretivm 2020 14.8.5 Concluding   Remarks: Model Validation Based on the various model validation checks   presented above, it is the QP’s opinion that the January 2020 resource model   is a reasonable representation of the input drilling data at the block scale   and a reasonable predictor of gold grade and contained metal, particularly in   well-drilled areas. 14-33 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 14.9 Mineral Resource   Classification Additional data generated as part of the 2019 infill drill   campaign and from extensive underground development completed since the July   2016 resource estimate were incorporated into an updated resource   classification for parts of the January 2020 Mineral Resource. Changes to the   resource classification were limited to that part of the resource estimate   updated in this study (see introductory comments to Section 14 and Section   14.6.1). Details of Measured, Indicated, and Inferred classification criteria   pertaining to the December 2013 estimate outside of the update area are   presented in Farley et al. (2014) and Jones (2014). Classification criteria   pertaining to the July 2016 estimate are presented in Board et al. (2017).   Classification criteria pertaining to the January 2019 estimate are presented   in Jones et al. (2019). The Mineral Resource defined in Farley et al. (2014)   and Jones (2014) was a global resource predicated on bulk mining, and   included the classification of Indicated Resources where the drillholes were   spaced up to 40 m apart. The May 10 (2014) definition standards of the   Canadian Institute of Mining (CIM, 2014) were followed in the classification   of the January 2020 resource estimate, whereby: A Measured Mineral Resource   is that part of a Mineral Resource for which quantity, grade or quality,   densities, shape, and physical characteristics are estimated with confidence   sufficient to allow the application of Modifying Factors to support detailed   mine planning and final evaluation of the economic viability of the deposit.   Geological evidence is derived from detailed and reliable exploration, sampling   and testing and is sufficient to confirm geological and grade or quality   continuity between points of observation. A Measured Mineral Resource has a   higher level of confidence than that applying to either an Indicated Mineral   Resource or an Inferred Mineral Resource. It may be converted to a Proven   Mineral Reserve or to a Probable Mineral Reserve An Indicated Mineral   Resource is that part of a Mineral Resource for which quantity, grade or   quality, densities, shape and physical characteristics are estimated with   sufficient confidence to allow the application of Modifying Factors in   sufficient detail to support mine planning and evaluation of the economic   viability of the deposit. Geological evidence is derived from adequately   detailed and reliable exploration, sampling and testing and is sufficient to   assume geological and grade or quality continuity between points of   observation. An Indicated Mineral Resource has a lower level of confidence   than that applying to a Measured Mineral Resource and may only be converted   to a Probable Mineral Reserve. An Inferred Mineral Resource is that part of a   Mineral Resource for which quantity and grade or quality are estimated on the   basis of limited geological evidence and sampling. Geological evidence is   sufficient to imply but not verify geological and grade or quality   continuity. An Inferred Mineral Resource has a lower level of confidence than   that applying to an Indicated Mineral Resource and must not be converted to a   Mineral Reserve. It is reasonably expected that the majority of Inferred   Mineral Resources could be upgraded to Indicated Mineral Resources with   continued exploration. Drillhole spacing, geological maps of the extensive   underground development, model validation (Section 14.8) results, and   production reconciliation (Section 14.8.4) were reviewed in detail as part of   the resource classification process. Existing wireframe solid interpretations   for Measured and Indicated classifications were then refined and validated.   Blocks in the January 2020 resource model were coded according to resource   classification using the revised wireframe solids, where: Measured Resources   are those with infill drilling characterized by up to 15 m spacing in areas   informed by new underground development. Measured Resources are expected to   be within 15% of production on a quarterly basis.  14-34 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE  Indicated Resources are those informed by   appropriately spaced (up to 25 m centers) drilling and using information from   a minimum of two drillholes. Indicated Mineral Resources using this   classification scheme are expected to be within 15% of production on an   annual basis. Portions of the Indicated Resource that fell outside of the   mineralised domain wireframes were downgraded to Inferred because of the lack   of confidence in the geological framework for those estimates. Indicated   Resources outside of the update box include drilling between 25-40 m centers,   originally considered appropriate for bulk mining of the deposit (Farley et   al., 2014; Jones, 2014). Additional infill drilling, ahead of mine   scheduling, will be necessary in these areas to increase definition of high   grade corridors within the broader stockwork zones should more selective   mining scenarios (e.g., longitudinal mining) be envisaged. It is the   Qualified Person’s opinion that the approach to resource classification is   appropriate given the nature of the mineralization in the Brucejack Deposit.   It is his opinion that the information used to define the Mineral Resource is   of a high quality and suitable for the estimation and classification of   resources with a high level of confidence. 14.10 Mineral Resource Reporting   14.10.1 Depletion Depletion was applied to the January 2020 resource model.   This includes the CMS of stopes (current to December 31 2019), full   development and manual depletion of areas that have been deemed unmineable by   the QP, engineers and geologists. The majority of the areas that have been   deemed unmineable are mainly artefacts of the CMS (e.g., pillars) and not   material volumes. However, there are instances of half-height stopes wherein   only half of the stope was mined, based on the block model and/or grade   control sampling. In such cases, the remainder of the stope has also been   removed from the mineral resource as there is no intention of mining it in   the future. The resource estimate identifies the general area wherein the   targeted grade is located in the mine. After the reserve process optimizes   the stope location and the life of mine plan is embedded, a grade control   drill plan is designed. The grade control drill plan is based on local   geologic information (e.g., mapping and jumbo sampling), in conjunction with   drilling and a mid-term mine planning model, and endeavors to optimize and   identify the exact spatial location of the mineralization. This process   results in leaving certain drill rings in-situ (based on grade) despite the   previous or current pre-processed resource model grade. These areas have not   been depleted from the January 2020 resource model but a lower grade has been   assigned based on subsequent sampling information. This mineralization is not   considered unmineable (depending on the assigned grade), but mining is   deferred to a later date and therefore considered to remain as a part of the   mineral resource. 14.10.2 January 2020 Mineral Resource for the Brucejack   Deposit The January 2020 Mineral Resource of the Valley of the Kings Zone is   reported above a cut-off grade of 3.5 g/t gold; differing from the previous   reporting above a gold equivalent (AuEq) of 5 g/t AuEq cut-off (calculated as   AuEq = Au + Ag / 53) used in the November 2012 (Jones, 2012c), December 2013   (Jones, 2014), July 2016 (Board et al., 2017), and January 2019 (Jones et   al., 2019) Mineral Resources. The decision to report the Mineral Resource at   a lower cut-off grade is based on a comparison between actual mining practice   and results and the resource model. 14-35 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The January 2020 Mineral   Resource of the West Zone continues to be reported above a cut-off grade of 5   g/t gold equivalent as there has been no further studies within the area. The   January 2020 Mineral Resource for the Brucejack Deposit (Valley of the Kings   Zone and West Zone) are presented in Table 14-15 and Table 14-16. January   2020 Valley of the Kings Zone Mineral Resource (1,2,3,4,5,6) Table 14-15:   Notes: (1)Mineral Resources which are not Mineral Reserves do not have   demonstrated economic viability. The estimate of Mineral Resources may be   materially affected by environmental, permitting, legal, marketing, or other   relevant issues. The Mineral Resources in this Technical Report were   estimated and reported using the CIM Definition Standards – Prepared by the   CIM Standing Committee on Reserve Definitions, Adopted by CIM Council May 10,   2014. (CIM, 2014). (2)The quantity and grade of reported Inferred resources   in this estimation are uncertain in nature and there has been insufficient   exploration to define these Inferred Resources as an Indicated or Measured   Mineral Resource and it is uncertain if further exploration will result in   upgrading them to an Indicated or Measured Mineral Resource category.   (3)Contained metal and tonnes figures in totals may differ due to rounding.   (4)Resources depleted for production to December 31, 2019. (5)The January   2020 Valley of the Kings Zone Mineral Resource is reported above a gold   cut-off grade of 3.5 g/t gold. The West Zone Mineral Resource is reported   above a gold equivalent cut-off grade of 5 g/t gold equivalent (AuEq) (where   AuEq=Au+Ag/53 as per previous models). (6)Mineral Resource is reported inclusive   of Mineral Reserve. Table 14-16 West Zone Mineral Resource, April 2012   (Jones, 2012a)(1) (1)Notes from Table 14-15 apply (see Jones, 2012a for more   details). Note: 14.10.3 Resource Sensitivity The portion of the January 2020   Resource Model categorized as Measured and Indicated for the Valley of the   Kings Zone (depleted for production up to December 31, 2019) is reported at a   series of gold cut-off grades to demonstrate sensitivity (see Figure 14-19).   Estimated gold grade decreases and tonnage increases at progressively lower   gold cut-offs (and vice versa at higher cut-offs). Gold grade remains above   10 g/t Au at a cut-off of 3.5 g/t Au. 14-36 Category Tonnes (Mt) Au (g/t) Ag   (g/t) Contained Au (Moz) Contained Ag (Moz) Measured 2.4 5.9 347 0.5 26.8   Indicated 2.5 5.9 190 0.5 15.1 Measured + Indicated 4.9 5.9 267 0.9 41.9   Inferred 4.0 6.4 82 0.8 10.6 Category Tonnes (Mt) Au (g/t) Ag (g/t) Contained   Au (Moz) Contained Ag (Moz) Measured 2.3 10.5 12.6 0.8 0.9 Indicated 16.1   11.4 12.2 5.9 6.3 Measured + Indicated 18.4 11.3 12.2 6.7 7.2 Inferred 5.4   13.3 15.9 2.3 2.8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 14-19: January 2020   Valley of the Kings Zone Measured + Indicated Mineral Resource Sensitivity   14.11 Comparison with the January 2019 Resource Estimate As there have been   no changes to the West Zone Mineral Resource, nor the December 2013 and   January 2019 Valley of the Kings Zone Mineral Resources outside of the update   area (see introductory comments to Section 14 and Section 14.6.1), comparison   between the January 2020 and January 2019 resource estimates is limited to   the Valley of the Kings Zone inside the update area (see Table 14-17). The   comparison focuses on resource estimates that have not been depleted for   production to demonstrate the true variance between these models as informed   by definition drilling. 14-37 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 14-17: Comparison   Between January 2020 and January 2019 Estimates for the Valley of the Kings   Zone Inside the Update Area Only Note: These numbers have been reported for   comparative purposes and have not been depleted to account for production.   The reader should refer to Table 14-15 for the current January 2020 Valley of   the Kings Zone Mineral Resource, reported depleted of production as at   December 31, 2019. The January 2020 resource estimate effectively overwrites   the January 2019 resource estimate inside the update area. Comparisons   between these models (inclusive of mine production) show that the new   estimate is lower by approximately 0.7 Mt, 2.2 Moz Au, and 1.1 Moz Ag in the   Measured + Indicated Resource at similar estimated gold and silver grades,   using the same cut-off grade of 5 g/t AuEq (AuEq = Au + Ag / 53). The   differences between the two models are largely data-driven. Additional   tightly-spaced infill drilling, increased exposure of the mineralized system   during mining, and over 1.5 Mt of actual production since mine commissioning   have resulted in improved domain and local estimation parameter definition.   14-38 Resource Model Au Cut-off (g/t) Tonnes (Mt) Au (g/t) Ag (g/t) Contained   Au (Moz) Contained Ag (Moz) Measured January 2020 3.5 0.5 10.3 13.2 0.2 0.2   January 2019 3.5 0.5 13.8 14.8 0.2 0.2 Change - - -3.5 -1.6 - - Indicated   January 2020 3.5 7.2 10.8 8.4 2.5 2.0 January 2019 3.5 6.9 14.6 9.5 3.2 2.1   Change - +0.3 -3.8 -0.7 -0.7 -0.1 Measured + Indicated January 2020 3.5 7.7   10.8 9.1 2.7 2.3 January 2019 3.5 7.4 14.6 9.9 3.5 2.3 Change - -0.3 -3.8   -0.7 -0.8 - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 15.1 General The Mineral   Reserve estimate stated herein is consistent with the CIM Standards on   Mineral Resources and Mineral Reserves and is suitable for public reporting.   As such, the Mineral Reserves are based on Measured and Indicated Mineral   Resources and do not include any Inferred Mineral Resources. This Mineral   Reserve estimate update only pertains to the Valley of the Kings mining area;   no additional work has been completed on the West Zone since the 2014 FS   (Ireland et al. 2014).   TheValleyoftheKingsMineralReservesweredevelopedfromtheMineralResourcemodel   “res1912_MRM_NSC_2019_depl_101010_MO_OW_Reserve_id”, which was created by   Pretivm and provided in January 2020. These Mineral Reserves do not include   the mined-out material up to the year-end of 2019. 15.2 Cut-off Grade A NSR   cut-off grade of US$180/t or Cdn$230/t of ore was used to define the Mineral   Reserves. This cut-off grade is based on a 3,800 t/d mining operation and has   decreased from the previous cut-off grade of US$185/t from the 2019 Technical   Report on the Brucejack Gold Mine (Jones, 2019). Table 15-1 shows the average   site operating cost estimates over the LOM. Table 15-1: Cut-off Grade Costs   Note:(1)Total US$ rounded to nearest tenth of a dollar 15.3 NSR Model An NSR   model was created for the Mineral Reserves and used the parameters summarized   in Table 15-2. The NSR for each block in the Mineral Resource model was   calculated as the payable revenue for gold and silver, less the costs of   refining, treatment, transportation, assays, and penalties. The metal price   assumptions for delineation of the Mineral Reserves are US$1,250/oz Au and   US$15.60/oz Ag. A foreign exchange rate of Cdn$1.00:US$0.78 was used. The NSR   contributions for both doré and floatation were calculated separately, then   combined to create a total NSR for each block in the Mineral Resource model.   The recovery and mass pull percentages were calculated using trends from mill   data obtained throughout production. 15-1 Area Cost Mining Cdn$121/t   Processing Cdn$26/t Maintenance Cdn$42/t General and Administrative Cdn$41/t   Total (Cdn$) Cdn$230/t Foreign Exchange Rate Cdn$1.00:US$0.78 Total (US$)   US$180.00/t(1) 15.0MINERAL RESERVE ESTIMATES 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 15-2: NSR Parameters   Note: All costs and metal prices were based upon estimates and used solely   for the generation of the NSR model and delineation of the Mineral Reserves.   15-2 Items Units Parameters Foreign Exchange Rate Cdn$:US$ - 01:0.78 Metal   Prices Gold US$/oz - 1,250.00 Silver US$/oz - 15.6 Doré Selling Cost   Transport US$/Au oz doré - 2.9 Assays US$/Au oz doré - 0.45 Treatment US$/Au   oz doré - 0.5 Metal Payable Gold % - 99.95 Silver % - 99 Flotation   Concentration Mass Pull % - 0.0055*(S/C)+0.0401 Selling Cost Treatment   US$/dmt - 157.81 Refining US$/payable Au oz - 8.13 Refining US$/payable Ag oz   - 1.13 Transport US$/wmt - 166.13 Assays US$/wmt - 4 Metal Payable Gold % -   96.75 Silver % - 82.5 Arsenic Recovery % - 0.0367*(S/C)+0.485 Arsenic Penalty   US$/t concentrate As <= 0.2% 0 US$/t concentrate As > 0.2% (As-0.2)*7.5   Recoveries Gold Doré % Au_Doré = 15.009*ln(Au/s)+48.244)*0.0098 Flotation %   Au_Float = (-13.12*ln(au_s)+46.724)*(1.02/100) if (Au_Doré + Au_Float) >   98% Flotation Au_Float = 98 - Au_Dore Silver Doré % Ag_Doré =   15.009*ln(Au/s)+48.244)*0.0098 Flotation % Ag_Float =   (-13.12*ln(au_s)+46.724)*(1.02/100) if (Ag_Doré + Ag_Float) > 89%   Flotation Ag_Doré = (Ag_Doré)-((Ag_Doré)+(Ag_Float) - 89) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 15.4 Mining Shapes Pretivm   used the Mineable Shape Optimizer (MSO) module from Vulcan v. 12.0.0 software   to produce design excavations that met both the cut-off grade and operational   design criteria. The design criteria constrain the geometry of all planned   excavations to mineable shapes through the planned mining methods. Section   16.0 provides further detail on mining shapes and design parameters. The   preliminary shapes were individually refined where necessary to ensure stope   geometry viability and to minimize the amount of sub-economic material within   the shape volume that is inseparable from profitable material due to the   practical constraints of mining. The Mineral Reserve stope and development   shapes were used as the basis for mid-term mine planning by the Brucejack   Gold Mine site mine planning department. Based on further grade control   drilling and assaying work completed prior to mining, additional stope shape   changes may occur to adjust mining to the results of grade control work.   Based upon the NSR model, mineable shapes are only created where the average   grade of the stope is greater than or equal to 4.5 g/t gold. 15.5 Orebody   Description Mineral Reserves delineated at the US$180/t NSR cut-off define an   orebody consisting of numerous independent lenses in the Valley of the Kings   Zone and two distinct lenses in the West Zone extending over a 570 m vertical   distance from the 990 m elevation level to surface (approximately 1,560 m   elevation level). 15.5.1 Valley of the Kings Zone The Valley of the Kings   Zone hosts multiple lenses that comprise approximately 82% of the combined   Mineral Reserve tonnage. Mineral Reserves in the Galena Hill Zone are   proximal to the Valley of the Kings Zone and have been considered as part of   the Valley of the Kings Mineral Reserves. Strike length varies considerably   with elevation, but the core of the Valley of the Kings Zone has reserves   located within a 550 m strike length over an elevation change of 570 m. The   other main lens in the Valley of the Kings has reserves located within a 500   m strike length over an elevation change of 495 m. The average thickness of   the stope block varies by elevation. Table 15-3 shows the average mining   thickness of the main Valley of the Kings Zone by mining block. Table 15-3:   Main Valley of the Kings Zone Mining Thickness by Mining Block Narrow Mineral   Reserves have been delineated down to a minimum 10 m mining thickness. The   Valley of the Kings Zone has a slight plunge towards the east. 15-3 Level   Mining Thickness (m) 990-1050 16 1080-1170 13 1200-1290 13 1320-1560 14 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 15.5.2 West Zone Mineral   Reserves for the West Zone remain unchanged from the 2014 FS (Ireland et al.   2014) as no new drilling has been completed and no new information has been   obtained in this zone. Mineral Reserves within the West Zone are contained   within four lenses, three of which host 90% of West Zone Mineral Reserves.   Strike lengths vary considerably with elevation, averaging approximately 100   m in the larger lenses, while the smaller lenses are no more than 35 m along   strike. The average thickness is approximately 25 m, with the smaller lenses   averaging only 15 m. 15.6 Mine Call Factor Through 2.5 years of operations   and mining reconciliation, an applicable MCF has been determined necessary to   account for the local overcalling of historic resource and reserves. As this   MCF is based upon historic mining data of previous resources, it is only   applied to the areas of the current resource that have not been updated   (models 1 and 2). The MCF applies to areas estimated by the original 2013   Snowden resource (20131219_Snowden_V3_BM), and the 2019 resource updates   (“res1901_finmod_20190115_v3”) (models 1 and 2). The MCF has not been applied   to the West Zone (model 3) as mining has not yet occurred on this zone and   lacks any reconciliation statistics. Through mining data and reconciliations,   it was found that the best indicator of possible misrepresentation of grade   is the average spacing of diamond drillhole data influencing that particular   area of the model. It was found that as the amount of information influencing   that block decreased, the likelihood of local error significantly increased.   Therefore, as of 2019, Pretivm began using diamond drillhole spacing as a   measure of risk and a way of systematically applying an MCF to the mine   plans. When undertaking a statistical comparison of the reserve stope shapes   and the gold grades estimated in the block model, it was identified that the   mean grade of all the individual reserve shapes varied very little when   compared to diamond drillhole spacing. However, the same cannot be said about   the relationship between drillhole spacing and the individual estimated gold   grades of each block in the block model. During reconciliation, it was   observed that as drillhole spacing increased, the differential between   estimated gold grades and achieved mined out grades also increased. Further   reconciliation analysis shows that for regions of the model with tighter drillhole   spacing, significantly lower grade variance was observed between the   estimated and realized grades. Areas that were modelled with drillhole   spacings greater than 15 m exhibited greater variance between estimated and   observed grades, when compared to drillhole spaces of less than 12.5 m. From   a short term mine planning perspective, stopes that rely on higher drillhole   spacings for reserve estimation carry a lower statistical confidence, thereby   making the short term mine planning and forecasting more difficult. Figure   15-1 shows the relationship of average grade and population variance by   diamond drillhole spacing. 15-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 15-1: Population   Variance of Au Grade within the 2020 Reserves Based on Diamond Drillhole   Spacing 10.0 170 8.0 140 6.0 110 To account for the increased variability in   individual stope grades, an MCF is applied to the average stope grade of the   reserves. Each reserve shape is evaluated based upon its average insitu gold   grade along with its average drillhole spacing (DDH SPC). Based upon these   two averages, the average grade of the stope is capped at varying grades   depending on the average drillhole spacing. Reserve shapes that exhibit   higher variability, or greater DDH SPC, are accounted for by being capped at   lower gold grades. Reserve shapes that have closer average drillhole spacing   are shown to have statistically less grade variability, and thus, less likely   to be overcalled, are capped at a higher gold value. The MCF parameters used   are shown in Table 15-4. The MCF is only applied to the average grade of the   reserve shapes as it was found that capping of individual high-grade blocks   of the model would result in an unrealistic negative estimation of the grade.   Therefore, applying the MCF to the average grade of the stope limits the   impact of reducing these high nugget grades and provides a more appropriate   estimation of the expected grade. The MCF is applied prior to dilution and   only to the areas not updated in this resource update. By limiting its   application to these areas, the MCF is only applied to areas where historic   mining has taken place and previous reconciliations are valid. Through the   grade control program, Pretivm has found that significant material outside of   the reserve has grade that exceeds the economic threshold of the NSR model.   As this current MCF solely reduces the upper limit of the reserves, it is   expected that the overall ounce and tonnage predicted by the reserves with   MCF applied will be lower than what is actually present due to the   expectation that the grade control program will continue to identify out of   reserve material not captured in the current reserves. The parameters and   uses for this MCF will be adjusted as Pretivm gains more experience mining   the updated Mineral Resource and Mineral Reserves. A comparison of the MCF   and the 2019 Reserve Reconciliation is covered in Section 15.9. Table 15-5   shows the average insitu Au grade of reserves before and after the MCF is   applied. 15-5 Population Variance Au Grade (g/t) Population Variance of Au   Grade 19011.0 180 1609.0 150 1307.0 120 1005.0 DDH SPC <= 12.5mDDH SPC   >12.5m &DDH SPC >15m & <=25mDDH SPC > 25m <=15m DDH   Spacing Avg Au Grade2020 Reserve Au Distribution 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 15-4: Insitu Au Grade   Cap for the Mine Call Factor Table 15-5: Average Insitu Gold Grade of Stopes   Before and After Mine Call Factor Application Figure 15-2: Distribution of   Average Insitu Au Grade of Reserves Before Mine Call Factor Application   Histogram for Au (5g/t cut off) Au Grade 15-6 Frequency Model Resource   Category Au Mean (g/t) – Pre MCF Au Mean (g/t) – Post MCF 1 2 18.19 9.25 2 1   11.35 8.99 2 2 11.18 8.53 3 1 6.43 6.43 3 2 8.71 8.71 Diamond Drill Hole   Spacing (DDH SPC) Average Stope Au Grade Upper Limit (g/t) DDH SPC <= 12.5   m 17.5 DDH SPC > 12.5 m & <= 15 m 15 DDH SPC > 15 m & <=   25 m 12 DDH SPC > 25 m 12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 15-3: Distribution of   Average Insitu Au Grade of Reserves After Mine Call Factor Application   Histogram for Au After MCF Applied (5g/t cut off) Au Grade 15.7 Mineral   Reserve Depletion Due to Grade Control Program As part of the grade control   program, stopes are drilled and sampled via long hole or RC drilling. These   results are then analyzed, and depending on the grade and additional   geological factors, an ore/waste call is made on the associated drill ring.   Reserves that have been grade control sampled and determined to be uneconomic   with no potential to mine above the reserve cutoff grade have been   subsequently removed from the reserves. For a more complete explanation of   the grade control process, please refer to Section 14.10.1. 15.8 Dilution and   Recovery Estimates In evaluating the Mineral Reserves, modifying factors were   applied to the tonnage and grade of all mining shapes (both stoping and   development) to account for the dilution and ore loss. Ore dilution includes   overbreak into the design hanging wall and design footwall, as well as into   adjacent backfilled stopes. Diluting materials were assumed to carry no metal   values in the estimation of Mineral Reserve grades. The largest component of   dilution at the Brucejack Gold Mine will be paste backfill due to its   inherently weaker strength as compared to the hanging wall and footwall rock   masses for any given dimensions of exposure. Ore loss (recovery factors) is   related to the practicalities of extracting ore under varying conditions,   including difficult mining geometry, problematic rock conditions, losses in   fill, and blasting issues. The dilution factors were estimated from standard   overbreak assumptions based on Pretivm’s experience and benchmarking of   similar long-hole open stope operations: Long-hole stopes (primary,   secondary, and tertiary) carry 1.0 m of dilution from paste or country rock   overbreak into the design hanging wall and design footwall and 0.3 m of   backfill dilution from the floor.  15-7   Frequency 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Secondary or tertiary stopes   carry an additional 1.0 m of backfill dilution on each wall that exposes a   primary stope.  Sill pillar stopes are   treated as secondary stopes, given the additional backfill dilution that can   be expected from the roof.  Ore   cross-cuts carry 0.5 m of dilution from rock overbreak into the design   hanging wall and design footwall.    Production slashing of secondary stopes carries 0.5 m of backfill   dilution on each wall that exposes a primary stope.  Figure 15-4 shows the typical sources of   stope dilution. 15-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Figure 15-4: Sources of Stope Dilution Source:   AMC (2014) The application of the above parameters yields an overall LOM ore   recovery of 94% and an overall ore dilution of 12%. The use of parallel   production drillholes in stoping operations at the Brucejack Gold Mine will   provide improved dilution control in comparison to fan drilling (discussed   further in Section 16.0). These dilution and recovery factors were taken into   account when calculating the 2020 reserves. 15-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 15.9 2019 Mineral Reserve   Reconciliation The 2019 Mineral Reserve Reconciliation was completed by   evaluating the 2019 Mineral Reserves against the 2019 Mined Actuals. Reserve   shapes that are spatially proximal with the 2019 actual stopes and   development ore positions were compared to the 2019 Milled and Mined results.   Applicable reserve shapes were determined by the use of CMS scans of the   mined material for all material mined in 2019. In 2019, ore was mined from 67   stopes over 10 levels from the 1,170 m level to the 1,410 m level across a   distance ranging 290 m east to west and 155 m north to south. Late in 2019,   material was also mined from one stope on the 1,110 m level. Table 15-6 shows   the 2019 Reserve reconciliation versus the 2019 mined actuals. Table 15-6:   2019 Reserve Reconciliation vs. 2019 Mined Actuals The 2019 Reserve Material   is inclusive of reserve material that was identified as uneconomic with no   possibility of future mining via the grade control program. This material   amounted to 60,000 tonnes of 2019 Mineral Reserve material. The tonnage from   the 2019 Mined Actuals is 20% more than planned primarily resulting from the   identification of out of reserve material that was determined to be economic   via the grade control program. All material sent to the mill was determined   to be economic by this program. The 2019 grade control program identified   approximately 570,000 tonnes of material located outside of reserve shapes as   economic that the 2019 Mineral Resource model identified as sub-economic.   This material was either mined or added to drilled inventory throughout 2019.   These additional tonnes were not accounted for in the LOM plan reflected in   the 2019 Report and are not accounted for in the 2020 Mineral Reserve and   2020 LOM plan. The 2019 Reserve Reconciliation demonstrates the local   overcalling of the resource when compared to the Au reserve grades. After the   MCF has been applied we see a comparable reduction in grade. Table 15-7 shows   the reduction of grade of the reserves when separated by areas updated in the   2020 Resource. Table 15-7: 2019 Reduction of Reserve Grade After Application   of MCF 15-10 Portion of Reserves Tonnes (000’s) Au Grade After MCF Applied   Change in Reserve Au Grade Due to MCF Non Updated Area of Resource 6,906 8.8   -29% Updated Area of Resource 5,872 8.6 0% Total 12,778 8.8 -18% Year Tonnes   (000’s) Gold Grade (g/t) Contained Gold Ounces (000’s) Mined 2019 Reserve   Material 1,023 12.1 396 Grade Control Depleted 2019 Reserves 60 12.9 25 2019   Mineral Reserve Material in Reconciliation 1,083 12.1 421 2019 Mined Actuals   1,303 8.7 366 Reconciliation 120% 72% 87% 

    

 

TECHNICAL REPORT   ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001 |   MARCH 2020 | ISSUED FOR USE The 2019 Reserve Reconciliation is showing a 28%   reduction in grade, which is comparable to the Au reserve grade after the MCF   is applied. This results in a 29% reduction in grade in the applied areas. As   additional material is mined from the 2020 Reserves, the MCF will be adjusted   to account for the new findings. Currently no MCF is applied within the   update area, but as future reconciliations and mining data is compiled this   may change. 15.10 2020 Mineral Reserves Table 15-8 presents the Mineral   Reserves tabulated by zone and by reserve category. All Mineral Reserves are   scheduled in the LOM plan, which is presented in Section 16.0. The reserve values   reported are inclusive of mining factors such as dilution and mining   recovery. The reserve totals are indicative of material prior to milling;   therefore, milling recovery has not been included. This recovery is accounted   for in the LOM plan. The mining blocks divide the Mineral Reserves into   logical parcels consistent with the mining sequence and form the basis of the   LOM development and production schedule, also discussed in Section 16.0.   Table 15-9 details the Mineral Reserves by mining block, inclusive of the   MCF. Figures 15-5 to 15-7 show the Reserves in the Valley of the Kings and   West Zone. Brucejack Gold Mine Mineral Reserves(1,2,3,4) by Mining Zone Table   15-8: (1)Rounding of some figures may lead to minor discrepancies in totals.   (2)Based on US$180/t cut-off grade, US$1,250/oz Au price, US$15.6/oz Ag   price, and a Cdn$1.00:US$0.78 foreign exchange rate. (3)All reserve values   are inclusive of mining dilution and mining recovery. (4)Gold grades of   Valley of the Kings Zone are inclusive of Mine Call Factor. Notes: 15-11   Total Reserves Brucejack 2020 Mineral Reserves Tonnes (Mt) Au Grade (g/t) Ag   Grade (g/t) Au Ounces (Moz) Ag Ounces (Moz) Valley of Kings 12.8 8.8 10.0 3.6   4.1 Proven 1.4 8.9 11.1 0.4 0.5 Probable 11.3 8.7 9.8 3.2 3.6 West Zone 2.9   6.8 278.5 0.6 26.0 Proven 1.4 7.2 383 0.3 17.4 Probable 1.5 6.5 181 0.3 8.6   Combined 15.7 8.4 59.6 4.2 30.1 Proven 2.8 8.1 195.1 0.7 17.9 Probable 12.8   8.5 29.8 3.5 12.2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Brucejack Gold Mine Mineral   Reserves(1,2,3,4) by Mining Block Table 15-9: Notes: (1)Rounding of some   figures may lead to minor discrepancies in totals. (2)Based on US$180/t   cut-off grade, US$1,250/oz Au price, US$15.6/oz Ag price, and a   Cdn$1.00:US$0.78 foreign exchange rate. (3)All reserve values are inclusive   of mining dilution and mining recovery. (4)Gold grades of Valley of the Kings   Zone are inclusive of Mine Call Factor. 15-12 Zone Ore Tonnes Grade Contained   Metal (Mt) Au (g/t) Ag (g/t) Au (Moz) Ag (Moz) Valley of the Kings Zone   990-1050 1.3 8.8 5.4 0.4 0.2 1080-1170 3.3 8.6 7.8 0.9 0.8 1200-1290 3.1 8.4   9.2 0.8 0.9 1320-1560 5.1 9.1 12.9 1.5 2.1 Total 12.8 8.8 10.0 3.6 4.1 West   Zone Upper West Zone 0.6 4.2 407.0 0.1 8.0 Lower West Zone 2.3 7.6 245.0 0.6   18.1 Total 2.9 6.9 278.5 0.6 26 Mine Total All Mining Blocks 15.7 8.4 59.6   4.2 30.1 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 15-5: Reserve Shapes   and Mining Blocks in the Main Valley of the Kings Zone Source: Pretivm (2020)   15-13 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 15-6: Reserve Shapes   and Mining Blocks in the West Zone Source: AMC (2014) Figure 15-7: Combined   Reserves, Looking West Source: Pretivm (2020) 15-14 West Zone Upper 1290L to   1405L West Zone Lower 1045L to 1270L 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 15.11 Mineral Reserve   Comparison As significant material has been mined between the 2020 Mineral   Reserves and the 2019 Mineral Reserve update, a direct comparison of reserves   will not provide an accurate assessment of the changes made. To provide a   valid comparison, the inclusion of the mined-out material between these two   time periods needs to be added. As the 2020 Mineral Reserves are exclusive of   all material mined prior to January 1, 2020 and the 2019 Mineral Reserves   were exclusive of all material mined prior to January 1, 2019 the addition of   the reconciled 2019 milled actuals should provide a valid comparison. Table   15-10 shows the comparison. Table 15-10: Comparison of 2020 Mineral Reserves   with Mined Actuals to Previous Reserve(1,2) (1)Rounding of some figures may   lead to minor discrepancies in totals. (2)All milled actuals are based off of   reconciled year end results. 2019 milled actuals include material from   outside of the 2019 Reserves. Notes: The combined 2020 Mineral Reserves and   2019 Milled Actuals total ore tonnes exceed the 2019 Mineral Reserves due to   two main factors: the mining of out of reserve material that was identified   as being economic by the grade control program, and the increase in   profitability of the NSR model. With these additions, the combined 2020   Mineral Reserves with 2019 Milled Actuals contain more tonnes at a lower   grade than the 2019 Mineral Reserves. This results in a decrease in overall   ounces primarily due to a decrease in overall grade of the updated portion of   the resource. 15-15 Reserves Reserves Ore Tonnes (Mt) Grade Au (g/t)   Contained Metal Au (Moz) 2020 Mineral Reserves + Milled Actuals Proven +   Probable 15.7 8.4 4.2 2019 Milled Actuals 1.3 8.7 0.4 Total 17.0 8.4 4.6 2019   Mineral Reserves Total 16.0 12.6 6.4 2020–2019 Difference 1.0 -4.1 -1.8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.1 General Brucejack Gold   Mine development has been ongoing since the start of commercial production in   2017. The execution of the mine plan closely matches the mine plan as   disclosed in the 2014 FS (Ireland et al. 2014). Locations for some   infrastructure items have been adjusted to improve practicality as the mine   has developed. These changes include the location and type of the main   dewatering system and the utilization of settling sumps to pump the sediment   and slimes directly to the mill clarifier. The explosives magazine was moved   to isolate the location from the main works and to allow direct ventilation   exhaust to surface in the event of combustion or explosion. The layout for   the underground service facilities was also modified. The updated underground   mine design supports the extraction of 3,800 t/d of ore through a combination   of transverse and longitudinal LHOS. Paste backfill is integral to the mine   plan to maximize both orebody recovery and mining productivity. Modern   trackless mobile equipment is employed in the majority of mining activities.   A main decline, designated as the Valley of the Kings access, extends from   the surface portal near the concentrator and is used to access the mine and   as a conveyor way. The conveyors installed have a combined length of 800 m.   The existing West Zone portal will continue to provide access (and egress) to   the mine and serve as the main access for large underground equipment and   waste haulage. A fleet of LHD and underground trucks are used for material   loading and transport from the underground working areas and through an   internal ramp system that connects all levels to the centrally located   crusher. Permanent fans provide ventilation by forcing air down the declines   through the internal ramps and exhausting to surface via dedicated raises   that connect the working levels to surface in each zone. The primary fans are   located at each of the main surface portals. An electric mine air heating   system is used to take advantage of low electricity prices, with a propane   system available as a back-up. Ongoing development to sustain 3,800 t/d of   ore production will average approximately 900 m/mo during the first two years   of production ramp-up and will decrease around 250 m/mo for the remainder of   the LOM. Major underground infrastructure includes crusher, conveyors,   ventilation raises, fans, heating system, pumping stations, electrical   substations, explosives magazines, paste fill booster pump station, refuges,   mine communications, and other ancillary installations that include an   underground maintenance service facility and a fuelling facility 16.2 Mine   Design 16.2.1 Access and Ramp Infrastructure The Valley of the Kings Zone is   currently accessible via internal ramps between the 1,050 m and 1,470 m   elevation levels via both the Valley of the Kings ramp and the West Zone ramp   from surface. The continued infrastructure development program will utilize   this existing infrastructure. 16-1 16.0MINING METHODS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The Valley of the Kings   access decline joins the main surface portal to the Valley of the Kings ramp   at the 1,290 m and at the 1,320 m elevation levels on the West Zone access   ramp. The West Zone will likewise be accessed from the existing bulk sample   access drive during the latter half of the LOM. Figure 16-1 development   arrangement. illustrates the general Figure 16-1: Mine Access and Development   Infrastructure Source: Pretivm (2020) 16-2 West Zone West Zone Portal VOK   Portal Valley of the Kings 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The internal ramp starts at   the 1,335 m elevation level and proceeds up and down the Valley of the Kings   deposit at ±15% gradient. At the 1,290 m elevation level the internal ramp   connects with the bottom of the Valley of the Kings access ramp. The decline   and incline have been developed in a race-track configuration. An independent   ramp for each zone—as opposed to a single ramp servicing both the Valley of   the Kings Zone and the West Zone—was selected and developed in the interest   of access and capital efficiency, given that the West Zone is mined later   during the LOM. For ease of entry and exit, ramps have been developed with a   25 m turning radius and a 15% gradient, levelling out to a 0% gradient in   proximity to a level access intersection. Passing bays are incorporated where   required in the main Valley of the Kings Zone and West Zone access ramps.   Figure 16-2 shows the ramp system for both zones in perspective view. Figure   16-2: Brucejack Ramp System – Perspective View Crusher Source: Pretivm (2020)   16.2.2 Level Development Sublevels are accessed from the ramps on 30 m   vertical intervals that are defined by the planned stoping heights. Footwall   and/or hanging wall drives are set back a minimum of 10 m from the ore   contact, whereas ramp development is set back at a minimum of 50 m from the   ore contact. This arrangement promotes long-term geotechnical stability and   provides adequate space for the placement of a fresh air raise and other   ancillary services between the ramp and level development. Sublevels generally   have a raise on one or both ends, permitting the exhaust of contaminated air   from activity on the level. Figure 16-3 illustrates the Valley of the Kings   Zone sublevel arrangement in long section. 16-3 Valley of the Kings West Zone   Portal VOK Portal West Zone 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-3: Valley of the   Kings Zone Sublevel Arrangement – Long Section Source: Pretivm (2020) Level   development follows the general strike of the various lenses of the Brucejack   Deposit, providing access to the mineralized zones in a manner that allows   for either transverse or lateral mining; whichever is more suitable for that   zone of the deposit. Level development is generally in the footwall and   includes excavations for sumps, refuges, transformers, remucks, paste fill   line, and raise accesses. Stope-access cross-cuts located outside of the   Brucejack Fault Zone are on 15 m spacings for transverse stope blocks, while   the multiple access configuration of lateral mining stopes is determined   based on efficiency and mining sequence. This excludes those levels where   sill extraction or near-surface weathered ore is recovered in smaller stopes   that are designed to geotechnical criteria. Likewise, all Brucejack Fault   Zone ore is developed on 10 m spacings to accommodate poorer ground   conditions. These spacings are modified as geotechnical experience is gained.   Figure 16-4 illustrates typical level development requirements from the LOM   plan. 16-4 Valley of the Kings 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-4: Typical Level   Development – Valley of the Kings Zone Return Drive 1380m Level Sump Manway   Raise Source: Pretivm (2020) Level development design considers equipment   size, services, and required activity. Table 16-1 summarizes the design   parameters and Figure 16-5 illustrates standard designs for development   drives. Table 16-1: Development Design Parameters table continues... 16-5   Development Type Parameter Width (m) Height/Length (m) Maximum Gradient (%)   Remuck 5.5 5.5 2 Footwall Drives 5.5 5.5 15 Access Drive 5.5 5.5 2 Electric   LHD Cut-out 5.5 5.5 2 Conveyor Decline 6.0 6.5 15 Main Access Decline 6.0 5.5   15 Infrastructure Drive 5.5 5.5 2 Valley of the Kings and Raise RemuckReturn   Air Raise Electrical Paste Line Cut Footwall Drift Stope Footwall Drift 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-5: Standard Designs   – General Layout for All 16-6 Development Type Parameter Width (m)   Height/Length (m) Maximum Gradient (%) Drainage Cut-out 5.5 5.5 2 Waste   Cross-cut 5.0 4.5 2 Refuge Bay Cut-out 5.5 5.5 2 Ore Cross-cut 5.0 4.5 2   Fresh Air Drive 5.5 5.0 2 Return Air Drive 5.5 5.0 2 Paste Fill Line Drive   5.5 5.0 2 Vertical Alimak Raise 3.0 3.0 - Return Air Drive 3.0 3.0 - Fresh Air   Raise 3.0 3.0 - 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.2.3 Stope Design The   Brucejack Gold Mine uses the MSO module from the Vulcan mine planning   software package to produce conceptual stope shapes. Table 16-2 summarizes   the key design parameters used in the MSO. The conceptual stope shapes are   refined as necessary to minimize planned dilution and to meet practical   mining constraints. Table 16-2: Stope Design Parameters (1)Refers to stoping   in weathered material immediately below the surface crown pillar. Weathered   material extends 10 to 50 m below surface. Note: Individual areas meeting the   cut-off grade are evaluated against access development costs to determine   economic viability before including them in the mining plan. The LOM plan   includes 671 stopes in the Valley of the Kings Zone and 135 stopes in the   West Zone. The number of stopes may vary if stopes are combined or split for   optimization during operations. Figure 16-6 and Figure 16-7 are long-section   views showing stope shapes generated by the MSO process. 16-7 Parameter Units   Valley of the Kings Zone West Zone Standard Weathered(1) Sill Pillar Standard   Weathered(1) Sill Pillar NSR Cut-off US$/t 185 185 185 180 180 180 Level   Spacing m 30 30 30 30 30 30 Stope Span m 15 15 15 15 10 10 Minimum Mining   Width m 10 10 10 3 3 3 Minimum Waste Pillar Width m 5 5 5 5 5 5 Minimum   Footwall Dip degrees 85 85 85 60 60 60 Minimum Hanging Wall Dip degrees 85 85   85 60 60 60 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 16-6: MSO Stope   Shapes-VOK Zone •15m •6•0m Mined Slopes Source: Pretivm (2020) ['n;ITETR 16-8   A TECH Valley of the Kings Zone I Valley of the Kmgs Zone 1320L to 1560L   Valley ofthe Kings Zone 1200L to 1290L Valleyofthe Kings Zone 1080L to 1170L   Valley ofthe Kings Zone 990L to lOSOL Looking North Unmined Reserves 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-7: MSO Stope Shapes   – West Zone Source: Pretivm (2019) 16.3 Mining Method and Sequence 16.3.1   Block Definition The orebody is divided into six blocks, defined by elevation   and zone, that facilitate a total of 3,800 t/d of production from multiple   working areas. Mining progresses upward from the lowest elevation in each   block. The general levels are defined in the long-term mine plan, but the   selection has been redefined for operational considerations. The current   block sill levels are located at the 990 m, 1,080 m, 1,200 m, and 1,320 m   elevation levels for the Valley of the Kings Zone. 16-9 West Zone Upper 1290L   to 1405L West Zone Lower 1045L to 1270L 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.3.2 Stope Cycle The   predominant mining method is transverse LHOS and is based on a standard   primary/secondary sequence. No permanent pillars are required, and maximum   ore extraction is targeted. The footwall drives are completed, and a through   ventilation circuit is established before mining begins between any two   levels. Cross-cuts are driven from the footwall drive, through the centre of   the stope, to the far ore contact on the undercut and overcut levels.   Cross-cuts on both levels are supported by long support-system cables and   Swellex from the central access to pre-support the roof prior to full-width   slashing of the entire stope footprint. The secondary stopes are not slashed   to full width for ground control considerations. Long holes are drilled with   parallel holes, or in fan configurations, depending on whether the stope can   be safely slashed across the entire mineralized width. Where ground   conditions permit, full-width slashing allows parallel production hole   drilling across the entire width of the stope. This in turn reduces the   potential for ore in stope corners to fail due to inadequate free face or   poor explosives distribution. Ore recovery with parallel hole drilling is   typically higher than with fan drilling (in the absence of full-width   slashing). In poor or difficult grounds and in secondary stopes, fan drilling   is used due to geotechnical constraints, utilizing only the initial cross cut   and a hammerhead as the drilling platform. Once the stope footprint is   slashed out, a 762 mm pilot hole is drilled in the slot raise location.   Production drilling follows in the raise and slot area, followed by the   production rings, as drilling progresses towards the end of the stope. The   raise and slot are generally opened in five shots or less. Production   blasting and mucking proceed cyclically until the stope is depleted and all   ore has been mucked out. LHOS is a non-entry method, with remote mucking of   blasted ore required once the draw point brow is open to the extent where the   operator may be exposed to uncontrolled sloughing from the stope cavity. The   empty stope is remotely surveyed with cavity monitoring equipment. A   barricade is constructed in the draw point and the stope backfilled to just   below the floor elevation of the top level. Crushed aggregate or run-of-mine   (ROM) waste is spread over the fill surface to reduce backfill dilution and   increase trafficability of mucking equipment for the next lift of the stope.   In sills and other areas where top access is not available, mining proceeds   in a similar manner; however, raise development and production drilling is   performed via drilling up holes from the bottom level. Figure 16-8 illustrates   the typical LHOS design for these areas. Longitudinal LHOS is also employed   at the mine, where, in contrast to transverse LHOS, mining progresses along   the strike of the orebody to a common access point. Where applicable, the   overcut and undercut are slashed to the footwall and hanging wall contacts,   although in numerous longitudinal stopes no overcut is required, and ore is   extracted via upwards drilling. In all other respects, the stope cycle is   similar to transverse LHOS. 16-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-8: Typical LHOS   Design Source: AMC (2014) 16.3.3 Stope Sequence The mining sequence in any   area of a given block begins with the extraction of the primary stopes on the   first (lowest) level. Wherever possible, the first primary stope is located   near the middle of the lens to develop a pattern of stope extraction that   moves outwards to the extremities of the lens while progressing upwards   towards the top. This generally promotes a favourable redistribution of   ground stress, although many smaller lenses in the Brucejack orebody are   either irregular in shape or of insufficient dimensions to properly develop   this sequence. When the adjacent primary stopes from the level above have   been filled and cured, secondary stoping commences. Figure 16-9 illustrates   typical sequencing for the more massive lenses at the mine. 16-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 16-9: Example of   Primary/Secondary LHOS at Brucejack Gold Mine Crosscut & Slash # Mining   Sequence I I Source: Pretivm (2019) ['n;I 16-12 TETR A TECH Sill Pillar Level   Third Level Second Level First Level D Pastefill p Primary Stope D Rockfill   sSecondary Stope --I I--10 -,-,-I I 17 -,-,-II 8 -,-,-II 20 -,-,-II 16   -,-,-II 7 -,-,-II 14 -,-,-II 6 -,-,-II 19 -,-,-II 13 -,-,-II 5 -,-,-II 12 -   ,-,-II 4 -,-,-II 18 - ,-,-II 11 -,-,-II 2 9 1 15 3 -,-,-II   --r--r-T--r--r-IIIII --r--r-T--r--r-IIIII p sp sp 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.3.4 Backfilling The   primary means of backfilling is paste fill, generated from unclassified mill   tailings mixed with adequate cementitious binder to meet the strength   requirements of re-exposure. Regular strength paste fill is commonly required   where there will be re-exposure of vertical stope walls. Stopes that are   planned to not be re-exposed by adjacent mining and are below the 1,350 m   elevation level may be backfilled with unconsolidated waste and/or by paste   fill with sufficient binder to remove any risk of future liquefaction   (low-strength paste fill). High-strength paste fill will be required in the   lower portion of all primary and secondary stopes that will be undercut by   sill extraction from below. Table 16-3 tabulates the total projected paste   fill volumes over the LOM by strength requirement and by binder dosage. Table   16-3: LOM Paste Fill Requirements Required 16.3.5 Paste Backfill Test Work   Pretivm engaged AMC Mining Consultants (Canada) Ltd. (AMC) to undertake the   first stage of a high-level study on the suitability of using mill flotation   tailings for paste fill at the Brucejack Gold Mine (AMC 2015). The results   showed a higher-then-expected cement requirement for the range of determined   paste fill strengths. The density of the paste fill was low and resulting strengths   required higher-than-expected cement content to achieve the target strengths.   Pretivm also engaged AMC to undertake second-stage laboratory testing. Stage   2 test work aimed to identify other classes of binders that would achieve   target strengths at lower dosing rates (AMC 2018). In particular, the Stage 2   test work investigated the use of blended blast furnace slag and fly-ash with   cement as possibly better paste mix recipes. The Stage 2 test work program   included: Material characterization tests in areas such as specific gravity   and particle size distribution    Determination of paste fill density at a yield stress of 250 Pa as the   benchmark for the paste fill mix  UCS   tests of mixes using General Purpose (GP) cement, slag, and fly-ash blend   cements to look at the effect of adding fine-ground iron blast furnace slag   and fly-ash to the GP cement binder; two slag blends were tested: MineCem   (MC) containing 55% slag and Sunstate Slag Blend (SS) containing 35% slag;   medium-size fly-ash (FA) was also used.  16-13 Paste Fill Type LOM Quantity ('000 m3)   28-day Strength (kPa) Binder Dosage (%) Density Dry Paste (t/m3) Mass Dry   Paste (t) Binder (t) High-strength Paste Fill 393 800 11.80% 1.11 436 46   Regular Paste Fill 2,630 300 6.80% 1.11 2,920 144 Low-strength Paste Fill   1,742 100 4.60% 1.11 1,933 95 Total 4,765 - - - 5,289 285 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE As shown in Table 16-4, the   Brucejack Gold Mine tailings paste fill mixes responded very favourably to   the slag-based and fly-ash binders. The test program demonstrated a   significant difference in the strength values for the paste fill mix with GP   cement compared to the slag-based (MC and SS) and FA mixes. The following   differences were noted: At 6% and 10% addition, consistently using MC binder   (slag content 55%) produced a paste fill strength of more than double that of   the GP mix.  At 6% and 10% addition,   the SS binder (slag content 35%) consistently increased paste fill strengths   by over 50% compared to the GP mix.    Using FA in the paste fill mixes reflected the expected lower strength   gain in the early curing time (14 days) typical of FA mixes. However, the   28-day and final 56-day strengths steadily gained higher strength levels,   showing the benefit of the FA in partly replacing the GP cement.  Table 16-4: Summary of Stage 2 UCS Results   Stage 3 strength and rheology test work on bulk sample material is currently   being completed to update paste recipes and binder dosages for the key   strength targets. For this study, AMC is adopting industry standard dosages   to achieve the required 28-day strengths, as outlined in Table 16-4. Pasting   operations at the Brucejack Gold Mine commenced in August 2017. AMC developed   paste fill recipes for various scenarios to be encountered during stoping,   like a requirement for a sill beam or backfilling of a secondary stope. AMC   recommended that Pretivm begin pasting operations with increased binder   addition (20% higher than recommended recipes) as a contingency while the   paste plant and pasting operations overall were being commissioned. During   this time, as site-specific, consistent paste quality control data was   acquired and analyzed by AMC, the recommended recipes would then be the   default recipes moving forward. 16.3.5.1 Waste Management and Stope Filling Waste   rock from mine development is generated on an ongoing basis throughout the   LOM. Stopes are filled with development waste wherever possible, with waste   additionally hauled to surface for disposal in Brucejack Lake. The   waste-backfilled stopes are mainly secondary stopes below the 1,350 m   elevation level in the mine. Waste generated before the start of secondary   mining is hauled to surface since it is unsuitable for backfilling primary   voids without a cementitious binder. 16-14 Batch Tailings (%) Cement/Binder   14 days 28 days 56 days 1 94 6% GP 405 448 565 2 90 10% GP 875 1,038 1,204 3   94 6% MC 909 1,145 1,428 4 90 10% MC 2,008 2,507 2,783 5 94 6% SS 577 738 903   6 90 10% SS 1,525 1,831 1,920 7 94 3% GP + 3% FA 340 537 681 8 90 5% GP + 5%   FA 1,050 1,824 2,415 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE In addition, disused headings   in mined-out areas are used for development waste disposal, and an allowance   has been made in the waste disposal profile in this respect. The disposal of   waste rock in underground stopes has the effect of reducing the total void   volume requiring paste backfill, and hence reduces the percentage of mill   tailings that can be returned to underground. Table 16-5 tabulates the   projected volumes of waste to be generated from milled ore and development   headings and the destination of these volumes over time. Over the LOM, 62% of   development waste and 33% of tailings generated from milled ore will be   placed back underground; the balance will be disposed of in Brucejack Lake.   Table 16-5: LOM Backfilling – Waste Rock and Mill Tailings 16.4 Development   and Production Schedule 16.4.1 Production Rate From the start of commercial   production in July 2017, the mine had been operating at a rate of 2,700 t/d.   In December 2018, Pretivm received a permit to allow a mining rate increase   to 3800 t/d. The updated Measured and Indicated Mineral Reserves supports   this increase. A detailed mine design was subsequently completed for the new   Mineral Resource model and scheduled to 3,800 t/d steady state ore   production. There is a ramp-up period of identified in the production   schedule, which is considered reasonable and achievable with respect to   current development plans. The final production schedule was constrained to   reflect realistic mining practices and availability of equipment. The model   limits the number of active stopes at any one time to four blasting and   mucking, one backfilling, four drilling, and up to seven curing. The average   number of active stopes at any one time is 12, with variations from 10 to 16.   16-15 Year Ore Tonnes ('000 t) Total Tailings ('000 t) Waste Tonnes ('000 t)   Waste Fill Tonnes ('000 t) Waste Fill Volume ('000 m3) Paste Fill Volume ('000   m3) Tailings Underground ('000 t) Waste to Surface ('000 t) 2020 1,387 1,301   676 175 70 349 388 501 2021 1,387 1,305 702 240 96 331 367 462 2022 1,387   1,306 650 316 126 347 386 334 2023 1,387 1,307 654 164 66 399 443 490 2024   1,387 1,306 216 192 77 432 480 24 2025 1,387 1,305 245 176 71 389 432 69 2026   1,387 1,313 177 176 70 415 461 2 2027 1,387 1,316 51 48 19 474 526 3 2028   1,387 1,318 41 35 14 453 503 6 2029 1,040 987 32 30 12 403 447 2 2030 1,040   981 20 19 8 353 392 1 2031 693 653 13 11 4 253 281 2 2032 380 357 6 5 2 166   184 1 Total 15,637 14,754 3,483 1,587 635 4,765 5,289 1,896 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.4.2 Sustaining Development   Development of the Valley of the Kings Zone Upper and Middle blocks alone is   insufficient to sustain 3,800 t/d of ore production. The Lower blocks must   also be developed as a critical path activity. The following development   activities will run in parallel with the Upper block development and mining   and will continue until the Lower block begins producing critical stope ore   in the fourth year of activity: Advancement of the Valley of the Kings ramp   downward to the 990 m elevation level    Development of the 1,080 m, 1,140 m, and 1,170 m elevation levels  Continuation of VR1 from the 1,140 m   elevation level to the 1,050 m elevation level  Excavation of the fresh air raise system   from the 1,020 m elevation level to the 1,080 m elevation level  Excavation of the fourth exhaust raise in   two stages from 1,200 m elevation to surface.    The Valley of the Kings ramp development will advance to the bottom of   the mine (990 m elevation level). Levels will continue to be developed and stoping   will continue in all four blocks. Development to the West Zone will begin   later in the LOM to allow production from the Lower and Upper West Zone   blocks. This development will be timed such that the 3,800 t/d mining rate   can continue for as long as possible without interruption. Table 16-6 shows   the LOM development rates. Table 16-6: LOM Development Requirements 16-16   Year Capital Operational Total Lateral (m) Vertical (m) Ore (m) Waste (m)   Lateral (m) Vertical (m) 2020 730 447 2,749 8,520 12,000 447 2021 916 186   2,050 9,033 12,000 186 2022 1,006 234 1,902 7,892 10,800 234 2023 1,131 325   1,626 8,043 10,800 325 2024 0 237 1,240 3,083 4,324 237 2025 0 105 1,186   3,462 4,648 105 2026 0 65 1,222 2,665 3,887 65 2027 0 25 284 736 1,020 25   2028 0 18 325 636 961 18 2029 0 16 291 475 766 16 2030 0 0 227 334 561 0 2031   0 0 172 223 396 0 2032 0 0 51 99 150 0 Total 3,783 1,658 13,327 45,202 62,312   1,658 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.4.3 LOM Production   Schedule Full 2,700 t/d production was effectively achieved in Year 1 (2017).   In Year 3 (2019), the mine completed ramp up to 3,800 t/d. Figure 16-10 shows   the LOM production schedule and the phasing of the various blocks. Figure   16-11 shows the LOM split of production by development and stoping. Figure   16-10: LOM Production Schedule by Mining Horizon 1,200 400 Figure 16-11: LOM   Production Schedule by Activity 1,200 400 16-17 Mined Tonnes ('000t) Mined   Tonnes ('000t) Mined Au Grade (g/t) Mined Au Grade (g/t) LOM by Ore Type   1,60010.0 1,4009.0 8.0 7.0 1,0006.0 8005.0 6004.0 3.0 2.0 2001.0 00.0 2020   2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 Stope TonnesDev   TonnesAu Grade (g/t) LOM by Mining Regions 1,60010.0 1,4009.0 8.0 7.0   1,0006.0 8005.0 6004.0 3.0 2.0 2001.0 00.0 2020 2021 2022 2023 2024 2025 2026   2027 2028 2029 2030 2031 2032 West ZoneFault ZoneMain VOKAu Grade (g/t) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 16-7 is a summary of   projected LOM production tonnes and grade. Table 16-7: LOM Tonnes and Grades   16.5 Geotechnical SRK undertook a geotechnical review and evaluation of the   Brucejack Gold Mine Project that included a review of historic geotechnical   data, underground excavation conditions, stope performance, and structural   geology to support the confirmation of underground mine design and   geotechnical design guidelines. These guidelines included excavation design   parameters, estimates of dilution, as well as ground support requirements.   The various elements of the geotechnical evaluation program and their   findings are discussed in more detail in the following sections. The source   data for the geotechnical review and design confirmation came from previous   studies conducted by BGC supplemented with data provided by Pretivm’s   technical personnel and collected during site inspections and reviews by SRK   in 2019 and early 2020. The geotechnical data, excavation designs, and   recommendations contained in the 2013 FS (Ireland et al. 2013; 2014),   combined with observed mining practices and ground condition, provided the   basis for the geotechnical review and evaluation. Geotechnical site   investigations completed to support the 2013 FS assessments included   geotechnical drilling and logging, oriented drill core measurements, borehole   televiewer surveys, laboratory testing of rock core samples, and installation   of borehole instrumentation to measure groundwater pressures. Geotechnical   mapping of the dewatered historic underground workings was completed to   provide structural geology information. The geotechnical performance of   excavations in the existing mine were also reviewed. The FS site   investigations were supplemented by a review of historical reports and   inclusion of data collected during previous site investigation programs.   16-18 Year Ore (kt) Au (g/t) Ag (g/t) 2020 1,387 8.3 13.7 2021 1,387 8.6 9.3   2022 1,387 8.6 10.7 2023 1,387 8.6 11.4 2024 1,387 8.4 14.0 2025 1,387 8.6   51.8 2026 1,387 8.4 98.1 2027 1,387 8.6 88.5 2028 1,387 8.6 57.4 2029 1,040   8.4 110.1 2030 1,040 7.4 122.1 2031 693 7.2 159.3 2032 380 7.0 231.0 Total   15,637 8.4 59.6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.5.1 Rock Mass Properties   The rock mass of the Brucejack area was divided into eight main geotechnical   domains in the 2013 FS based on the characteristics of the rock mass. The   geotechnical units in the Valley of the Kings Zone are as follows: The Valley   of the Kings Fault Zone (VOK FZ) unit includes fault-disturbed rock. The   Fault Zone unit includes Brucejack Fault Zone rock and rock from all geologic   units. It is strong with good RQD (Bieniawski 1976) and close discontinuity   spacing.  The Valley of the Kings   Weathered Rock Zone (VOK WRZ) unit comprises near-surface weathered rock. This   unit is strong with good RQD and close discontinuity spacing.  Rock mass Valley of the Kings Domain 1 (VOK   D1) comprises the Argillite (ARG) geologic unit and is very strong with good   RQD and moderate discontinuity spacing.    Rock mass Valley of the Kings Domain 2 (VOK D2) comprises the Bridge   Zone Porphyry (BZP1), Office Porphyry (OFP1) and Silcap geologic units, which   are strong with excellent RQD and moderate discontinuity spacing.  Rock mass Valley of the Kings Domain 3 (VOK   D3) comprises the Volcaniclastics, VSF, S3-Trans, and ANDX geologic units,   which are very strong with excellent RQD and wide discontinuity spacing.  The geotechnical units in the West Zone are   as follows: The West Zone Fault Zone (WZ FZ) unit includes fault-disturbed   rock. This unit is strong (according to the methods of ISRM (1978)) with fair   rock RQD and close to moderate discontinuity spacing.  The West Zone Weathered Rock Zone (WZ WRZ)   unit includes weathered, near-surface rock. It is medium strong with good RQD   and moderate discontinuity spacing.    The West Zone Fresh Rock (WZ FR) unit comprises all remaining rock,   which is very strong with excellent RQD and wide discontinuity spacing.  Table 16-8 summarizes the rock mass   parameters used in the design. Table 16-8: Rock Mass Parameters Summarized by   Geotechnical Domain table continues... 16-19 Geotechnical Unit UCS(3) (MPa)   Median GSI(1) Average Unit Weight(2) (kN/m3) mi mb S Erm(4) (GPa) VOK FZ 89   60 26.3 12 1.110 0.0023 5.13 VOK WRZ 50 63 28.6 17 1.879 0.0037 0.77 VOK D1   116 72 27.2 17 3.211 0.0144 9.76 VOK D2 95 70 27.1 19 3.186 0.0106 9.02 VOK   D3 73 85 27.3 26 10.647 0.1030 14.37 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE (1) Geologic Strength Index   (GSI) is calculated from median rock mass parameters for each unit, where GSI   = RMR '76. (2)Unit weights are based on average results of specific gravity   testing when possible. (3)UCS = Intact unconfined compressive strength.   (4)Erm = Young’s Modulus of the rock mass. The Hoek-Brown failure criteria   (mi, mb, s) were estimated assuming a disturbance factor ('D') of 0.8 for all   units. The Hoek-Brown curves were derived using a sigma3 maximum for a tunnel   depth of 650 m. Notes: 16.5.2 Mine-scale Fault Zones The three-dimensional   major structures (fault) model developed by Pretivm shows that four large   (i.e., mine-scale) fault zones are known to intersect the mining footprint:   the Brucejack Fault Zone, the Rainy Fault, the Valley of the Kings Main   Fault, and the Upper Thrust Fault, as seen in Figure 16-12. Figure 16-12:   Oblique View of the Interpreted Mine-scale Faults at the Brucejack Area   Looking Approximately South Source: Pretivm (2020) 16-20 Geotechnical Unit   UCS(3) (MPa) Median GSI(1) Average Unit Weight(2) (kN/m3) mi mb S Erm(4)   (GPa) WZ FZ 77 57 26.3 12 0.928 0.0015 4.27 WZ WRZ 37 62 28.6 17 1.771 0.0032   0.73 WZ FR 116 85 27.3 21 8.599 0.1030 16.77 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The Brucejack Fault Zone is a   northerly striking anastomosing fault zone located along the western margin   of the study area and extends north to the Iskut River Fault. In places, the   lineament appears to be several sub-vertical to moderately (greater than 60°)   dipping fault strands braided together. The zone has normal faulting with   variable displacement estimated at 500 to 800 m (ERSi 2010). It is comprised   of a core of highly fractured rock with a zone of less fractured,   fault-disturbed rock mass on either side. The width of the fault zone varies   with depth and along strike from approximately 5 to 40 m. It is considered to   be continuous along strike, dips slightly to the east above the 1,325 m   elevation, and dips slightly west below the 1,325 m elevation. For design   purposes, the median RQD, joint condition, and point load index derived UCS   value (ISRM 1985) are 62%, 16, and 3.5 MPa, respectively, compared to the   “excellent” median RQD value (91%) and median point load index derived UCS   value of 6.5 MPa in the surrounding undisturbed VOK D2 rock mass. The Rainy   Fault is a gently dipping (10 to 30°) south-southwest striking (220 to 240°)   fault. The fault has a thickness ranging between 0.5 and 15 m (average   thickness is 2 m), with the thickness appearing to increase with depth. The   rock mass within the Fault Zone is generally very blocky with very poor to   poor RQD (less than 50%) and discontinuity spacing of less than 0.20 m but   varies from relatively unbroken rock to compact silty/clayey gouge zones up   to 1.5 m thick. Often, the fault zone is comprised of multiple gouge zones   separated by more competent zones of very blocky rock mass. Seepage   conditions within the zone vary significantly, from dry to dripping. The   Valley of the Kings Main Fault is gently-dipping and south-southwest   striking, and was intercepted during the FS drilling program. The Fault Zone   resulted in locally reduced RQD (between 40 to 80%) and fracture spacing   (between 0.06 to 0.50 m) compared to the fresh (unfaulted) rock. The Upper   Thrust Fault is highest in the stratigraphic sequence of the three known   faults in this package of gently-dipping, south-southwest striking structures.   This structure does not appear to intersect any of the current or planned   mine workings, and as such, has not been considered in the geotechnical   assessment. 16.5.3 Underground Rock Mechanics 16.5.3.1 Excavation   Geotechnical Design Approach stability assessments have been completed using   well-established empirical and semi-empirical relationships and engineering   experience. These relationships enable estimates to be made of the expected   mining conditions and support requirements based on a detailed description of   the rock mass, excavation geometry, and prevailing stress conditions. The   design procedure involves two steps: the quality of the rock mass is rated   using a pre-defined classification system, and then the expected performance   of the underground openings is predicted using an empirically derived   stability correlation with the rock mass quality. Two distinct rock mass   classes were used in the geotechnical review and evaluation. A Fair to Good   rock mass class with RMR76 values greater than 40 and a Poor to Very Poor   rock mass class with RMR76 values less than 40. 16.5.3.2 Geotechnical Design   Criteria (Man-entry Excavations) The required man-entry design spans (3 to 5   m) have been reviewed based on the critical span design curve presented by   Ouchi et al. (2004). In the static stress condition, the excavations in the   fair to good domains are expected to remain stable with standard ground   support (i.e., rock bolt and mesh). Additional ground support (i.e., rock   bolt, mesh, and shotcrete) and modifications to standard excavations are   required in the poor to very poor domains to maintain stable excavations.   16-21 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Full width (15 m) undercuts   for primary stopes in the fair to good rock mass class are considered   acceptable utilizing the ground support described in Table 16-9. Full width   undercuts are not recommended in the poor to very poor rock mass class or in   secondary stopes in either rock mass class. The structural stability of the   excavations was analyzed using an empirical design chart after Grimstad and   Barton (1993) and Unwedge© (Rocscience 2003) to develop minimum ground   support recommendations. Ground support analyses for primary (permanent   “man-entry”) and secondary (temporary “development”) headings were conducted   in each structural domain. Recommendations for minimum ground support for   lateral development are provided in Table 16-9 with in-ore stope development   supplemental support recommendations in Table 16-10. 16-22 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 16-9: Lateral   Development Minimum Ground Support Recommendations 16-23 Rock Mass Dimension   Ground Support Type Length Spacing Additional Comment Condition (m x m) (m)   (m x m) Level Development (Access Drift, Level Drift, Remuck And Refuge   Station) Fair to Good 5.5w x 5.5h #7 fully grouted rebar plus #8 welded wire   screen to cover the back and walls to maximum 2.5 m from sill. 2.4 1.8 x 1.8   (RMR76 > 40) Poor to Very Poor 2.4 1.2 x 1.2 Special instruction might be   required from geotechnical engineer. 2.4 m long Swellex may be required in   very poor ground conditions. Screen is to be installed down to 1.5 m from   sill. (RMR76 < 40) Main Ramp (Decline, Incline and Other Hauling Routs)   Fair to Good 6.0w x 5.5h #7 fully grouted rebar plus #8 welded wire screen to   cover the back and walls to maximum 1.5 m from sill. 2.4 1.8 x 1.8 (RMR76   > 40) Poor to Very Poor 2.4 1.2 x 1.2 Special instructions might be   required from geotechnical engineer. (RMR76 < 40) Cross Cut (Waste Cross   Cut) Fair to Good 5.0w x 5.0h #7 fully grouted rebar plus #8 welded wire   screen to cover the back and walls to maximum 3.0 m from sill. 2.4 1.8 x 1.8   (RMR76 > 40) Poor to Very Poor 2.4 1.2 x 1.2 Special instruction might be   required from geotechnical engineer. 2.4 m long Swellex may be required in   very poor ground conditions. Screen is to be installed down to 1.5m from   sill. (RMR76 < 40) Cross Cut (Ore Cross Cut) Fair to Good 5.0w x 5.0h 2.1m   Splitset plus #8 welded wire screen to cover the back and walls to maximum   3.0 m from sill. 2.1 1.2 x 1.2 (RMR76 > 40) Poor to very poor 2.1 1.2 x   1.2 Special instruction might be required from geotechnical engineer. Screen   is to be installed down to 1.5 m from sill. (RMR76 < 40) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 16-10: Minimum In Ore   Supplemental Ground Support 16-24 Rock Mass Dimension Ground Support Type   Length Spacing Additional Comment Condition (m x m) (m) (m x m) Top Cut of   Ore Stope (Primary Stopes) Fair to Good 5 - 15 w x 5 h Single strand cable   bolts 6 2.5 x 2.5 (RMR76 > 40) Poor to very poor 5 w x 5 h Single strand cable   bolts 6 2.0 x 2.0 Special instruction might be required from geotechnical   engineer. (RMR76 < 40) Top Cut of Ore Stope (Secondary Stope) Fair to Good   5 w x 5 h Double strand cable bolts 12.5 2.5 x 2.5 (RMR76 > 40) Poor to   Very Poor Double strand cable bolts 12.5 2.0 x 2.0 Special instruction might   be required from geotechnical engineer. (RMR76 < 40) Bottom Cut of Ore   Stope (Pilot Drift and Secondary Stopes) Fair to Good 5 w x 5 h Connectable   Super Swellex 4.88 2.5 x 2.5 Three Superswellex per ring in the back to be   installed before slash. (RMR76 > 40) Poor to Very Poor Connectable Super   Swellex 4.88 2.0 x 2.0 Three Superswellex per ring to be installed before   slash. Special instructions may be required from geotechnical engineer.   (RMR76 < 40) Bottom Cut of Ore Stope (Primary Stopes, Full Width Expansion   for Drilling) Fair to Good 15 w x 5 h Connectable Super Swellex 4.88 2.5 x   2.5 Three Superswellex per ring to be installed prior to slashing out to full   width. Slashed area will have the rest of the Superswellex installed into the   pattern as the slash is developed. (RMR76 > 40) Poor to Very Poor 5 w x 5   h Connectable Super Swellex 4.88 2.0 x 2.0 Special instruction might be   required from geotechnical engineer. (RMR76 < 40) 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Where very poor ground   conditions are encountered underground, local assessment of the ground should   be conducted by mine rock mechanics personnel and suitable modifications to   excavation practices and ground support made. Consideration should be given   to using Swellex bolts of equivalent length in place of resin grouted rebar   in very poor ground condition because of potential issues with ensuring   adequate mixing and bonding of the resin. Where poor ground conditions are   encountered associated with fault zones, then excavation practices may need   to be modified such as shortening round length and supplementing standard   ground support with shotcrete. 16.5.3.3 Geotechnical Design Criteria (Stope   Design and Dilution) For non-man entry excavation, such as longhole stopes,   assessments were completed using the modified Matthews stability curve after   Stewart and Forsyth (1995) and the failure iso-probability curves developed   by Mawdesley and Trueman (2003). A range of stope dimensions were evaluated   for stability and dilution. A fixed sub-level spacing of 30 m (floor to   floor) was used for all mining zones with maximum strike length, stope span,   and geotechnical dilution determined for each of the mining zones. Empirical   estimates using the estimated linear overbreak and sloughing (ELOS) approach   and benchmarking have been used to come up with the dilution estimates   (Clark, 1998). Based upon the rock mass conditions, the stope dimensions and   geotechnical dilution estimations presented in Table 16-11 are considered   appropriate for the fair to good and poor to very poor rock mass classes.   Table 16-11: Stope Dimension and Dilution Guidelines Where stopes are planned   within fault zones, there is the potential for reduced stability and   increased dilution. Further shortening of stope lengths should be considered   if stope performance and dilution is unacceptable. Maximum achievable   secondary stope dimensions will be predominantly controlled by backfill   performance. SRK recommends that the Brucejack Gold Mine review actual stope   performance and recovered volumes against planned stope volumes to identify   any potential stope performance patterns associated with specific   geotechnical domains or geologic structures. Stope dimensions can then be   modified to optimize safe ore recovery. 16.5.3.4 Crown Pillar To maximize   crown pillar recovery, the minimum crown pillar thickness for the West Zone   and the Valley of the Kings Zone is 15 m. SRK recommends the cable bolting of   the crown pillar using 5.0 m long single strand bulbed cable bolts on a 2.5 m   spacing. Tight filling of both primary and secondary stopes immediately below   the crown pillar is recommended. 16-25 Rock Mass Condition Maximum Stope   Dimensions (m) Estimated Geotechnical Dilution (ELOS) (m) Fair to Good (RMR76   > 40) 15 w x 30 h x 15 to 40 l < 1.0 Poor to Very Poor (RMR76 < 40)   15 w x 30 h x 15 l 1.0 to 3.0 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.6 Mobile Equipment   Requirements 16.6.1 Production Phase The mining contractor supplies the bulk   of the heavy equipment, with the exception of supplemental long-hole drills   for production and sampling and some auxiliary vehicles. Table 16-12 lists   the required equipment for development, stoping, and support activities.   Table 16-12: Major Underground Development and Production Equipment List   16.6.1.1 Jumbos Development advance (in ore and waste) will average   approximately 500 m/mo during the first 12 years of production. Two-boom   units, capable of drilling holes 3.6 m deep, have been selected by the   contractor to perform the work. Data from the first 18 months of operations   show the jumbos averaged 780 m/mo, or approximately 390 m/mo per unit,   exceeding the projected performance from the 2014 FS (Ireland et al. 2014).   There is a single-boom jumbo on site that is used as a back up to the   two-booms and for utility work where the two-boom is inefficient in smaller   headings. The single boom is used sparingly. 16.6.1.2 LHDs On site there are   three, 10 yd LHDs and five, 8 yd LHDs for production and development. This   fleet is sufficient for the 3,800 t/d operation of the mine. The mine is   evaluating battery electric LHDs as an alternative to diesel LHDs. 16.6.1.3   Haulage Trucks The mine contractor has twelve, 30 t trucks on site to support   the development required to maintain current production. Later when the   majority of ore hauled to the crusher is from the lower levels or the West   Zone, one additional truck maybe required to support operations. The need for   additional haulage capacity may be 16-26 Description Total Number of Units   Required 6 yd Scoop 1 8 yd Scoop 5 10 yd Scoop 3 30 t Trucks 12 Development   Jumbos 3 Long-hole Drills 5 RC Drills 4 Bolters 5 Emulsion Carrier 2 Face   Emulsion Loader 2 Bulk Emulsion Loader/Carrier (LH) 1 Shotcrete Machine 1   Transmixer 2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE counteracted by the reduction   of development needs at that same time, depending on the LOM schedule. The   mine is researching the use of electric haul trucks on a trial basis and initially   to be used as supplemental units until the evaluation is completed. The   battery trucks could replace the diesel trucks providing benefits in costs,   environmental health, and safety. 16.6.1.4 Bolters The ground control   management plan for pattern bolting development headings and stope backs   utilizes bolters equipped for the installation of rebar and split set bolts.   Currently, three Maclean bolters and a Rowbolter are on site, with one   additional Maclean bolter added to the fleet for the 3800 t/d increase. The   bolters are also used to assist in the installation of cable bolts. The mine   is investigating a transition from Maclean bolters to Rowbolters. 16.6.1.5   Long-hole Drills Production drilling is performed with top and bottom hammer   drills. Slot raises are drilled with a V30 bit to allow void space in the   slot. On site there are currently four drills; one additional drill will be   added to the fleet for production drilling and an RC drill has been added and   an additional three more are being added for sampling. 16.6.1.6 Explosive   Loaders One face charger is on site and another one will be required for the   3,800 t/d production increase for development loading. For a period, there   will be up to nine rounds per day that will require loading. Each unit has   pumps for face charging with emulsion. In addition to the face charges, there   is one long-hole loading unit available for uphole and downhole emulsion   loading in the stopes. 16.6.1.7 Shotcrete Sprayers It was anticipated that 5   to 10% of development would require shotcrete; however, to date, shotcrete   has primarily been required in areas near the Rainy Fault. Shotcrete is also   required for paste fill exposures in stope development and barricade   construction for backfilling and ventilation bulkheads. One unit is on site   and provides adequate capacity for this activity. Wet, non-fiber-reinforced   shotcrete is used as the standard. 16.6.1.8 Transmixers Shotcrete is   delivered from the underground batch plant. The contractor has two   transmixers at the mine to support shotcrete operations on site. These are   sufficient for the needs of the mine. 16-27 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.6.2 Support Equipment   Table 16-13 presents the complete list of support equipment. Table 16-13:   Support Equipment List 16.6.2.1 Personnel Carriers Personnel are transported   in mancarriers. There are 4 carriers and 14 Kobotas to transport personnel   through the mine. Technical services and Pretivm supervision use underground   Toyota trucks of various configurations to access and work in the mine.   16.6.2.2 Scissor Lift Trucks The contractor has three scissor lift trucks to   support development and occasionally assist Pretivm maintenance crews.   16.6.2.3 Lubrication Truck There is a lubrication truck on site to service   underground equipment. The lubrication truck is required to fuel and   lubricate all equipment that is not likely to return to the shop area at   frequent intervals. Downtime can be reduced by keeping equipment near the   working headings. This also helps improve traffic flow on the ramp. This   equipment includes LHDs, jumbos, long-hole drills, and bolters. The service   truck travels between these equipment pieces to perform daily servicing.   16-28 Description Total Number of Units Required MT Truck 1 Cassette Water /   Fuel Truck 1 Skid Steer 1 Telehandler 4 Shotcrete Machine 1 Transmixer 2 Boom   Truck 2 Scissorlift 3 Kabota Tractor 2 Jeffery Flatdeck/Boomtruck 1 Jeffery   Lube Truck 1 Kabota RTV Personnel Carrier 14 Four-man Jeffery Mancarrier   Personnel Carrier 1 Ten-person Jeffery Mancarrier Personnel Carrier 3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.6.2.4 Boom Trucks Boom   trucks are required for daily transport of materials from surface to   underground and to facilitate loading and unloading. Material stockpiles are   set up throughout the mine for supplies such as rock bolts, screen, resin,   vent duct, etc. 16.6.2.5 Explosives Vehicles Explosives consumption is   roughly 6.0 t/d of bulk emulsion per day and is delivered to the mine in three   custom-made ISO-standard tanks, each with a capacity of 17,500 L. A   purpose-built truck transports the full tanks to the emulsion bays. Emulsion   pumps are used to transfer emulsion from the full 17,500 L tank to 21,000 L   ISO tanks in the emulsion bay. Consumption averages three ISO tanks per week.   All other explosives are transported to the cap and powder magazines by the   explosives handling truck. Approximately 272 to 610 caps and primers are   required daily for development, depending on advance rates, with 60 caps and   primers per day on average required for the long-hole production blasting.   16.6.2.6 Water Truck The water truck is on site to facilitate mine wall   washing on an ongoing basis. 16.6.2.7 Tractors, Telehandlers and Utility   Vehicles Tractors are used for nipping materials and general transport   through the mine. All tractors are equipped with a cargo/man carrying   compartment in the back. Telehandlers are used for nipping materials and   general transportation throughout the mine and are also capable of being   fitted with man baskets for installing or maintenance of the services which   are out of reach from the ground. Utility vehicles are used by personnel for   quick transport between headings and will be the preferred mode of transport   for supervision and technical support staff. The following crews will be   issued utility vehicles for use during their shifts: Development   blasters  Backfill crew  Mechanics    Electricians  Production   blasters  Diamond drillers  Warehouse    Managers/shifters and technical support staff.  16-29 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.7 Ventilation The   ventilation system is designed to meet the requirement of the Health, Safety   and Reclamation Code for Mines in British Columbia – June 2017 (HSRCM), which   requires a minimum of 0.06 m3/s of ventilating air for each kilowatt of power   of diesel-powered equipment operating. Additional air is supplied for fixed   facilities and a leakage and balancing factor. All diesel-powered equipment   operating underground are fitted with CANMET certified engines. The design is   based on a “push” configuration, with permanent surface fans located at two   portals: the West Zone ramp and the Conveyor ramp. These two intake airways   provide sufficient ventilation capacity to support the underground mining   operations. To ensure the temperature of the air does not enter the mine   below the freezing point, mine air heaters are fitted in front of the primary   fans. The Valley of the Kings production ramp is connected to the intake   ramps to deliver fresh air to the active production levels. An escape-way   ladder system is installed in fresh air raises in parallel with the   production ramp. Fresh air travels from the production ramp, along the   footwall drives, and exhausted to return air raises located at the   extremities of the level. At the current time there are three exhaust raises   to surface; additional exhaust raises will be developed as the mine is further   developed. Regulators are installed at the raise connections to distribute   the required volume of air to the level. An appropriately designed and   located auxiliary fan and duct system force fresh air to development headings   and active stope faces. The underground fixed facilities have a dedicated   return air raise to eliminate the introduction of dust and other unwanted   contaminants into the production areas. The volume of air flowing through the   crusher area is controlled with a combination of fan and regulators. Figure   16-13 shows an isometric view of the Brucejack Gold Mine ventilation system.   Figure 16-13: Brucejack Gold Mine Ventilation System (Looking West) Source:   Pretivm (2020) 16-30 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.7.1 Design Criteria The   ventilation system design has drawn information from the HSRCM. As stated in   Part 4 of the HSRCM, Section 4.6.1 (3): “a minimum of 0.06 m3/s of ventilating   air for each kilowatt of power of the diesel-powered equipment operating   shall be circulated by mechanical means through every workplace where   diesel-powered equipment is operating”. A diesel engine exhaust emissions   dilution rate of 0.06 m3/s/kW is used in the ventilation system design. The   design criteria also includes commonly accepted industry best practices.   16.7.2 Total Airflow Requirements Total airflow requirements were determined   based on the diesel equipment fleet and fixed facilities required to support   steady state production and development activities. An airflow allowance was   also determined for leakage and balancing inefficiencies. The current total   airflow requirement for the Brucejack Gold Mine is as follows: Diesel   equipment – 345 m3/s  Fixed facilities   – 55 m3/s  Leakage and balancing (10%)   – 40 m3/s  Total – 440 m3/s.  16.7.3 Auxiliary Ventilation All work   areas, such as development headings and draw-points, not supplied with a   direct split of fresh air are ventilated using auxiliary systems. The   auxiliary systems consist of axial fans and flexible ducting. The fan power   and duct size are specified to provide the required amount of air for the   activity. Figure 16-14 shows a ventilation configuration for a typical   production level with auxiliary fans ventilating active areas. 16-31 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-14: Typical   Production Level 16.7.4 Permanent Primary Fans Over the LOM, there are a   multitude of settings for the ventilation circuit, depending on the type of   activities and their location throughout the mine. For operational   flexibility, the primary fans include a variable frequency drive (VFD) and   adjustable pitch blades. The fans and motors are capable of delivering the   required duty to meet the peak demands of the production and development   activities over the current LOM plan. Table 16-14 summarizes the primary fan   requirements. Table 16-14: Primary Fan Specifications 16-32 Description   Specification Fan Diameter 2.4 m Type Horizontal mount axial mine fan.   Adjustable pitch blades. Configuration Two forcing fans, each connected with   ducting to the WZ decline and Conveyor decline. Voltage 600 V Fan Motor 600 kW,   900 revolutions per minute, VFD capability 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.7.5 Mine Air Heating All   intake air entering the mine is heated for the following reasons: Protect the   health and safety of personnel working or travelling in intake airways.  Prevent the freezing of service water and   discharge lines.  Ensure reliable   operation of conveying and other mechanical equipment in the decline.  Maintain ice-free and safely trafficable   roadways.  Prevent rock surface (or   shotcrete lining) expansion/contraction damage from freezing and thawing of   rock joints in the upper parts of the intake airways.  Prevent ice buildup in airways that would   potentially lead to unsafe conditions.    Mine air heaters are located in front of permanent primary fans. Four   MW (2 MW per fan) of electrical heaters are installed as the primary heating   method. Propane heating is installed to augment the electrical heating in   extreme cold conditions. The heating system is designed and installed as per   the relevant requirements of the HSRCM (BC EMPR 2017). The system has been   submitted to the BC EMPR and approved. 16.7.6 Conveyor Decline The conveyor   decline is the main mine intake with dimensions of 6.0 m wide by 6.5 m high.   Care is taken to ensure that the air speed in the conveyor decline is not too   high to prevent the uptake of dust into the intake mine air. Given that the   conveyor is located in a primary air intake, the risk of the conveyor   catching fire is also managed. The design includes the following: Fire   retardant belt  Fire retardant grease   and lubricants  Ventilation controls to   isolate the air in the conveyor decline in the event of a fire  Regular inspection of the conveyor declines   during operation in order to detect the development of faulty rollers or belt   misalignment.  In the unlikely event of   a conveyor belt fire, fire doors placed in key areas would close and smoke   would flow directly to the workshop/crusher exhaust raise. Figure 16-15 shows   the isolation of conveyor fire contaminants from the ventilation circuit.   16-33 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-15: Conveyor Fire   Isolation Source: Pretivm (2019) 16.7.7 Emergency Preparedness In developing   the ventilation strategy for the Brucejack Gold Mine, consideration was given   to the potential for mine emergencies. As such, the following criteria was   established: In general, ramps are in fresh air once developed.  On almost all levels, escape can be either   to a ramp or to the escape ladder-way.    The escape ladder-ways are located in the internal fresh air raises   installed as part of the development of the ramps.  In each ramp, escape may either be up the   ramp or down the ramp to a safe area.    One permanent 40-person refuge station is established and services   both the WZ and the VOK Zone; another permanent 60 person refuge station is   being established and will service the Lower VOK.  Other refuge chambers are portable for   flexibility of location at the most appropriate points in the mine.  16-34 N Not to Scale 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE While the primary means of   communication is by radio, a stench system is in place for introduction of   ethyl mercaptan into both portals concurrently in the event of fire.  Fire doors are located in accordance with   legislated requirements and to isolate areas of high fire potential to ensure   noxious gases are not distributed through the mine workings.  There are a variety of incidents that would   trigger the emergency response plan and/or evacuation plan. Such events may   be fire, rock fall, injured personnel, or major ventilation equipment   breakdown. Emergency coordination occurs from the control room where all   information and communications can be monitored. The emergency response   procedures incorporate trained, onsite mine rescue teams made up of a cross   section of the workforce and staff. These teams will be trained in   administration of first aid and fire-fighting procedures. Since the Brucejack   Gold Mine site is considered remote, a first aid facility run by a trained   person, sufficient medical supplies, and provisions for an air ambulance and   landing pad is available. For the two surface portals, both of which are   supplied with fresh air, the West Zone portal is considered the primary   escape and the conveyor portal the secondary escape. For the production   stoping blocks, a ladder-way is installed in each of the raises located next   to main ramps. The raises are sized to afford easy passageway. For the   production stoping blocks, a ladder-way is installed in each of the raises   located next to the main ramps. The raises are sized to afford easy   passageway. Ladder-ways are designed, installed, and maintained in compliance   with the HSRCM, Sections 6.28.1 through 6.28.7 (BC EMPR 2017). The exhaust   raises to surface are for ventilation only and not used as a second means of   egress. Therefore, the exhaust raises do not have ladder-ways installed. An   automatic stench gas warning system is installed on the supply side of the WZ   vehicle portal and conveyor portal. When fired, this system will release   stench gas into the main fresh air system allowing the gas to permeate   rapidly throughout the mine workings. Once stench gas is released,   underground mine personnel would report immediately to the nearest mine   refuge station or surface, whichever is closer. The primary purposes of fire   doors are to prevent noxious gases from reaching workers should they be   trapped underground and to prevent fire from spreading as much as possible.   Fire doors are required to isolate the following areas: Magazine  Conveyor decline.  Portal doors are also designed to meet the   fire door criteria. 16-35 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8 Underground   Infrastructure 16.8.1 Mine Dewatering Mine dewatering is designed to   accommodate groundwater inflows from the Valley of the Kings Zone workings,   the West Zone workings, and inflows from drill and other operating equipment.   Total inflows were estimated to be approximately 100 L/s (including service   water); however, to accommodate for uncertainty in the water inflow model,   the design capacity for the pumping system is based on maximum inflows of 139   L/s. Brucejack Gold Mine dewatering is handled by a combination of   submersible and horizontal centrifugal pumps located throughout the West Zone   and Valley of the Kings Zone working levels. The pumps handle ground inflow   and send drill water via multiple 30 m lifts throughout the mine. The main   sump consists of a single 30 m by 6 m wide sump with an outlet connected to the   centrifugal pump system. The flow of underground water with slimes is pumped   via four centrifugal pumps (two running, two backup) to the process plant on   surface via a dedicated line up the Valley of the Kings conveyor way.   Currently, there are sumps to the 1,110 m elevation level, with the remainder   of sumps created as development advances. To minimize up-front capital, pump   procurement is staged such that pumps only arrive as their assigned sumps are   excavated. Figure 16-16 is a line diagram of the current dewatering system.   16-36 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MlNE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 16-16: Dewatering Plan   JWZ1 JOOSUl.P 1 X JO HP TSURUMI PUMP UfTSTAnON U'"'OSWP UWZ 1 Z7 5   S1JI.IP U: S WPS u WATER TliEATI.IElT PlAliT Source: Pretivm (2019) I'1t:I   TETRA TECH 16-37 300 MU DRAN HOLE 1 UOS1NP U1 0SUUP 1380 Sl.Af.P u90   ""' SUMP AGrrATOI\SYSTEU1 X 60HP TSURUM P\.J51 OPEN RA ISE TO OLD   WO S 1290 ti.A S\NP Iy-,-.u aA..·ER· nL 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8.2 Solids and Slimes   Handling Solids and slimes entrained in water are pumped through the   dewatering system to the main sump located at the 1,290 m elevation level.   This main sump is described in Section 16.8.1. 16.8.3 Materials Handling The   crusher is located at the 1,300 m elevation level of the mine close to the   Valley of the Kings Zone. The tipple for the ROM bin is located at the 1,335   m elevation level. ROM material is transported underground by truck from the   West Zone and the Valley of the Kings Zone and is preferentially dumped onto   the ROM bin grizzly. If the ROM bin is full, or for other reasons the trucks   cannot dump into the ROM bin, the trucks will dump into remucks near the ROM   bin location. Material stockpiled in the remucks will be re-handled and   deposited onto the grizzly by a LHD. At the grizzly, material smaller than   400 mm falls through to the ore bin and larger material is broken down by a   hydraulic rock breaker stationed above the grizzly screen. Figure 16-17 shows   a sectional projection through the coarse ore bin with the rock breaker and   scalping grizzly. Figure 16-17: Tipple and Ore Bin Sectional Projection 16-38   

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The 750 t capacity ore bin   feeds material down through a hopper at the bottom of the bin to a vibratory   feeder. This vibratory feeder transports the ROM material to a jaw crusher   and the crusher reduces the material down to 120 mm or finer in size and   drops this product down the fines chute to the crusher belt conveyor. Figure   16-18 shows an isometric view of the crusher feed and crusher. Figure 16-18:   Crusher Feed and Crusher The 1 m wide belting on the crusher conveyor carries   material at a rate of approximately 225 t/h from the crushing area to the   intermediate conveyor at a speed of 1 m/s. The ore on the crusher conveyor   moves past a magnet that removes any tramp iron, depositing this iron into a   waiting bin. The intermediate conveyor also moves at a rate of 1 m/s,   transporting the ore up the intermediate decline tunnel to the main conveyor.   The main conveyor exits the decline tunnel into the portal structure. The ore   is dropped onto the mill feed conveyor, which exits the portal structure and   carries the ore to the mill through an enclosed, heated, rectangular gallery.   16-39 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8.4 Power Requirements and   Electrical Distribution BC Hydro indicated that the total electric power   supply available for the Brucejack Gold Mine site is limited to a connected   load of 20 MW only if no electrical reinforcement is added to the main BC   Hydro Line. The maximum underground connected load to support full production   and development activities is approximately 8 MW, inclusive of ventilation and   heating. Considering the other key consumers of mine power, such as the mill   and paste plant, the power available for mine air heating is limited to 4 MW.   As the mine air heaters will at times require more than the fixed 4 MW of   electric power, a propane direct-fired system makes up the remaining heating   requirement. Figure 16-19 shows the growth of the power requirements over the   LOM in relation to ore production. Ventilation and heating, mobile equipment,   and dewatering are the main consumers of power. The maximum running load is   estimated to be 8 MW and will occur when full production levels are achieved.   As the mine is developed deeper, the dewatering power demand will increase   due to a higher lifting head and increased inflows. As development activity   and production decrease, the power requirements will also reduce. Figure   16-19: Underground Power Requirement Profile Electrical power is supplied to   the mine three ways: Through the Valley of the Kings portal into the   underground electrical substation service (ESS) comprised of two 500 MCM   cables serviced at 4.16 kV  Through the   West Zone portal from the E4C e-house comprised of one 500 MCM cable serviced   at 4.16 kV  Through a borehole from   surface to the lower mine comprised of one 500 MCM cable serviced at 4.16   kV.  16-40 Running Load (MW) Production   tonnes (kt) 81600 71400 61200 51000 4800 3600 2400 1200 00   20202021202220232024202520262027202820292030 Year Ventilation &   HeatingCrushing & ConveyingMobile Equipment Workshop &   Misc.DewateringOre Tonnes (ktpa) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The E4C e-house, which   supplies power to the underground workings, is comprised of one 3,000 A   breaker that is fed from the mill to supply transmission line power to the   E4C bus. The E4C bus has a 3,000 A tie-breaker to facilitate splitting the   bus if necessary. There are also additional loads that feed off the E4C   e-house such as: Underground ventilation fan house  Camp services  Underground workings through the West Zone   portal  Underground supply through a   borehole.  The system is comprised of   two zig-zag transformers that supply a neutral grounding resistor on either   side of the tie-breaker. Only one is on at any given time to supply the   system with a ground reference. The E4C also has the breakers that tie the   two 1,450 kW generators, six 1,850 kW generators, and transformer that feeds   the bus via four 600 V generators. The underground system is distributed via   4.16/0.6 kV portable transformers. The transformers are fed through load   break switches, which enable the transformers to be de-energized for   maintenance purposes. The additional feeds to the underground system run via   the West Zone portal, the Valley of the Kings portal, and through a borehole   fed via the E4C e-house. All the transformers are distributed as per the   above configuration. These transformers feed mine development, pumps, fans,   lights, and all electrical workings underground. Figure 16-20, Figure 16-21,   and Figure 16-21 show single-line electrical diagrams for the underground   mine. 16-41 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-20: West Zone   Portal Underground Single-line Diagram 16-42 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-21: Borehole   Underground Single-line Diagram 16-43 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-22: ESS Feed to   1080 Single-line Diagram 16-44 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8.5 Compressed Air   Compressed air is supplied by two compressors located near the West Zone   portal and by three compressors spread through the Brucejack Gold Mine to   reduce line loss in the system. The in-the-hole drilling equipment has   portable compressors close to the drill to meet their elevated pressure   requirements. 16.8.6 Service Water Supply Service water for drilling and dust   control is supplied via a 100 mm (4 inch) steel line at the Valley of the   Kings portal. The line continues through the Valley of the Kings decline ramp   to the supply sump. The water supply sump is located at the 1,320 m elevation   level in the West Zone area along the West Zone access. From this sump, the   mine is supplied service water from which the pressure reducing valves (PRV)   will be supplied at the 1,320 m, 1,230 m, 1,140 m and 1,050 m levels to   reduce the supply pressure below 689 kPa (100 psig). Near the 1,380 m and   1,440 m elevation levels, a booster pump station is installed to supply   operating pressure for the upper portion of the Valley of the Kings Zone.   Over the last year, the process water requirements for all the mine equipment   jumbos, long-hole drills, bolters, diamond drills, and other equipment was   approximately 1000 m3/d for development and stoping. Figure 16-23 is a   schematic of the main water distribution system. Figure 16-23 Mine Service   Water Distribution Schematic Source: Pretivm (2019) 16-45 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8.7 Fueling and   Lubrication Daily fuel consumption is estimated to be approximately 5,500 L.   Currently, an underground fuel bay has not been excavated and facilities have   not been installed. Large mine equipment haul trucks, LHDs, and vehicles that   come to surface regularly fuel up on surface. Other equipment such as   bolters, jumbos, and scissor decks are fueled by a lube truck. An underground   lube bay may be installed in the future. 16.8.8 Workshop and Stores The main   maintenance area is located on surface (covered in Section 18.0 of this   report). All major scheduled planned maintenance and rebuilds take place in   the surface shop. Various areas throughout the mine are used to store   consumable supplies. 16.8.9 Explosives Magazine The entrance to the   explosives magazine has rollup doors and man doors to allow access from both   ends of the facility. Two bays provide storage of bulk emulsions; one bay   contains a 20,000 L storage tank and storage area, and the other bay contains   a 17,000 L storage tank and storage area. A powder bay is designated for the   storage of all other explosive products (other than the bulk emulsion and the   detonators) on wooden shelves. A fourth bay is designated for the storage of   detonators on wooden shelves. A concrete wall with a steel door separates   this bay from the rest of the mine works. Figure 16-24 shows the underground   magazine layout. 16-46 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 16-24: Bulk   Emulsion/Powder Magazine Storage Plan Source: Pretivm (2019) Currently bulk   emulsion will be transported by the explosives supplier directly from the   manufacturing plant to the KM 48 explosive magazine/transfer. Each shipment   will be delivered via transport trailer with one custom made 17 t (17,500 L)   ISO tank per load. The ISO tank trailer will be transferred to the Brucejack   Gold Mine site immediately upon arrival. Once the full ISO tank is offloaded   from the transport trailer onto the special built emulsion hauler, the hauler   will take the ISO tank to the emulsion storage area, where the emulsion will   be pumped out of the tank into one of the two installed tanks. Once emptied,   the ISO tank will be brought to surface, reloaded onto the surface 16-47 N 50   m 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE transport trailer, and taken   to the KM48 magazine area where it will wait for the next load to come in and   the transport truck to take it to the manufacturer’s facility for refilling.   16.8.10 Refuge Stations A refuge station (Figure 16-25) is located between   the decline and incline drifts at the Valley of the Kings Zone. The station   accommodates 40 people and is equipped with an airlock entrance, a battery   back-up electrical system, an air conditioning unit, a carbon dioxide/carbon   monoxide scrubbing unit, cache of oxygen-type cylinders, and emergency supply   of first aid, food, water, and oxygen candles. The refuge station is located   in a bay off a drift and is separated from the drift by a concrete wall.   Access to the station is through an airlock system. This refuge station is   also used as a lunchroom. Figure 16-25: Permanent Refuge Station 6 m Source:   Pretivm (2019) 16.8.11 Communications 16.8.11.1 Fiber Optics and Phone and   Radio Communications The mine has a multifaceted communications system using   fiber optics as a data/telephony back bone and leaky feeder for voice   communications for crew. The underground network infrastructure consists of:   Fiber optic redundant loops  Wireless   LAN transceivers  Leaky feeder radio   communications system.  Radio   communications is a leaky feeder system using Motorola digital hand and base   mobile radios for voice communication throughout the mine. 16-48 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8.11.2 Personnel and   Equipment Tracking Personnel tracking is accomplished via the wireless access   point (WAP) installation throughout the mine and interrogating devices to   allow location tracking of personnel and vehicles. The system will be   integrated into a browser-based tracking and reporting application, allowing   operators and mine controllers to monitor, track and allocate personnel and   resources. Having the ability to ensure that mine staff are accounted for in   an emergency increases safety and speeds up the provision of help to any   potentially injured personnel. Tracking vehicles and assets also leads to increased   productivity and efficiency by eliminating time wasted looking for equipment   underground. 16.8.11.3 Fixed Plant Monitoring and Control Programmable logic   controllers (PLCs) will be used for fixed plant monitoring and control.   Remote PLC racks are placed near equipment (as necessary) and will monitor   and control the underground systems, including but not limited to:  Rock box levels  Crusher    Conveying equipment  Magnet  Substations    Sumps and pumps  Ventilation   equipment. The fibre optic backbone throughout the mine provides a means for   monitoring the remote PLCs from surface from both the mill control room as   well as other dedicated supervisory control and data acquisition (SCADA)   systems. 16.8.12 Portal Structure The portal structure has been constructed   at the access to the underground Valley of the Kings decline tunnel. The   structure houses a mine air heater and ventilation fan, the top conveyor   drive motor and structure, an electrical substation, and the access way for   vehicles to enter the Valley of the Kings portal though the building. The   main decline conveyor exits up from the portal and transfers ore to the mill   feed conveyor. This transfer is located inside the portal structure. Access   into the portal structure is via one of four overhead doors and man doors.   The portal structure was built up against the mill site high wall and to   resist roof snow loads with pressures up to 400 kg/m3. A monorail located in   the ceiling of the portal structure allows for removal of the mine air fan   motor and components. 16.8.13 Heating System and Propane Storage The   electrical energy is used to run mine air heaters, with propane supplementing   the electric heater during colder ambient temperatures, when the electricals   cannot maintain the temperature set point to provide above freezing air to   the mine. The propane for the two heaters is stored in two vertical storage   tanks in both the Valley of the Kings portal area and the West Zone area. The   tanks are located in accordance with regulatory clearance requirements to the   mine portals. Each of the two tank farms contains two tanks with a capacity   of 68,180 L each or a total of 136,360 L per tank farm. 16-49 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.8.13.1 Climatic Data In   the 2014 FS (Ireland et al. 2014), climactic data from site was analyzed to   quantify the amount of annual electric power and propane required for mine   air heating. This established the operating parameters for the currently   installed mine heaters. Reviewing the current year of data shows that the   design parameters was within 10% of actual. The volumes will change depending   on the severity of the temperature experienced at the mine site year to year.   16.8.14 Propane Supply Mine air heating is the only consumer of propane for   the underground operations. Surface infrastructure, including the camp,   requires propane; however, storage of propane for this purpose is independent   of mine air heating. Table 16-15 shows the first and second full-year monthly   and annual propane consumption for mine heating during steady state   operations. Table 16-15: 2018 Propane Consumption Note: (1)Based on delivery   dates. Propane for mine air heating is delivered to site approximately seven   months of each year. The propane is delivered to site via the Brucejack   Access Road. The propane supplier remotely monitors the levels in the propane   farms and initiates a tank fill as required to ensure there are adequate   supplies at the mine site at all times. A 50,000 L propane delivery truck   drives from Terrace, BC to the Brucejack Gold Mine site, and the delivery   truck transfers propane into the various site tank farms. The site tanks   supply propane to the heaters via a buried pipeline. The frequency of propane   delivery is dependent upon the air temperature and airflow volume required   for the mine. During the coldest months of the year, January and February, at   the maximum airflow volume, the mine air heaters consume approximately 5,500   L of propane each day of the month. 16-50 Month Propane Consumption 2018 (L)   Propane Consumption 2019 (L)(1) January 115,226 202,375 February 267,534   119,410 March 147,316 277,386 April 15,469 0 May 8,122 0 June 8,787 550 July   0 4855 August 0 0 September 961 13,082 October 0 0 November 0 5,704 December   58,670 55,381 Total 622,084 678,743 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16.9 Paste Fill Distribution   Paste from the surface plant is fed to the underground stopes through a   pipeline system. The paste was characterized through laboratory rheology   testing on un-cemented paste samples. The paste fill distribution requires a   two-stage pumping system. A positive displacement pump in the paste fill   plant provides paste to all of the West Zone (West Zone Upper and West Zone   Lower) and the lower zones of the Valley of the Kings Zone (below the 1,350 m   level). The paste plant pump also feeds a booster pump located near the ramp   to Valley of the Kings Zone. This booster pump pumps paste up to the Upper   Valley of the Kings Zone and Galena Hill (1,350 m level and above). Due to   line resistance of longer pipelines to the stopes, the booster plant will be   required to pump paste below the 1,350 m level. The paste pumps are positive   displacement piston pumps of 100 m3/h peak capacity with a pressure rating of   120 bar. The nominal flow rate for the system is 80 m3/h, with a nominal   design supply rate of 112 dmt/h. The underground booster pump station   currently has one pump installed and includes a pump feed hopper, a water   tank with a high-pressure pump for pipeline flushing, and a level platform   for changing the distribution routing through the mine. A second pump is on   order and will be installed as backup. If there is an upset during pasting   operations, there are two points that can be used to allow an emergency drain   of the system to prevent the pipe system from plugging. The first point is   located at the low point in the line between the mill and the 1,345-level   booster station and the second point is located at the first low point after   the booster station for the lines going into the upper part of the mine.   Instrumentation installed to ensure controlled operation includes pressure   sensors on each operating level, cameras to allow the control room vision of   conditions at the booster pump, power activated diversion valves and manual   diversion stations, and integrated process control within the paste fill   plant. This paste fill distribution system provides paste to the stopes at a   nominal yield stress of 250 Pa with a range of 100 to 375 Pa. This equates to   cemented paste percent solids of 66.1% solids by weight (ranging from 62 to   69% solids by weight). The piping specified for this distribution system is 8   in API 5L X52. The schedule of the pipe varies with the pressure rating of   the area: borehole casing and loops in the Upper Valley of the Kings Zone   levels are Schedule 120, while the Lower Valley of the Kings Zone and all the   West Zone casing and loops are Schedule 80. The main drift piping (trunk) and   level piping to the stopes is Schedule 80 and Schedule 40, respectively.   Victaulic couplings are used as the connection method for the level   distribution lines. 16.9.1 Distribution System Design The pipe routing for   the underground distribution system (UDS) was developed taking into   consideration site conditions, pipeline operation experience, and hydraulic   modelling. Some of the conditions that were taken into account in the design   include:  The difficulty foreseen in   accessing any trenched pipelines on surface due to site conditions,   especially during winter months  The   mining schedule, which defines that the Valley of the Kings Zone will be   developed in the early years while the West Zone will only be developed in   the second half of the LOM 16-51 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The long distance from the   paste fill plant to the underground workings (more than 800 m)  The location of the paste fill plant below   the elevation of the top third of the Valley of the Kings Zone.  The mining schedule breaks down the   Brucejack orebody into six areas: VOK-990 to 1050, VOK-1080 to 1170, VOK-1200   to 1290, VOK-1320 to 1560, WST-U, and WST-L, as shown with their respective   elevations in Figure 16-26 and Figure 16-27. The first areas to be mined will   be the VOK-1200 to 1290, and VOK-1320 to 1560, which are currently being   mined. Production in VOK-1080 to 1170 will start in Year 2 (2020), while the   WST Zones will only come online after Year 8 (2026). The Valley of the Kings   Zones have continuous production scheduled until end of mine life. The paste   fill distribution system was designed with the schedule shown in Table 16-5   in mind. The main challenge for the Brucejack paste fill distribution system   is that a portion of the orebody is located above the elevation of the paste   fill plant. A balance in strategy is required to ensure that paste can be   pumped to this section of the orebody without compromising the quality and   proper flow distribution to the rest of the mine. 16.9.2 Distribution   Approach The philosophy developed for the paste fill distribution system is a   dual pumping system. This optimizes the pumping capacity and minimizes wear   on the paste pumps. A positive displacement pump in the paste fill plant will   provide paste to all of the West Zone (WST-U and WST-L) and the Lower Valley   of the Kings Zone (below the 1,350 m level). The paste plant pump will also   feed the booster pump located near to the main entrance to the Valley of the   Kings Zone on the 1,345 m elevation level. This booster pump pumps paste up   to the Upper Valley of the Kings Zone (1,350 m level and above). Figure 16-26   shows the breakdown of the Brucejack Deposit ore zones by the paste pumps   feeding them: single pump zone and dual pump zone. Figure 16-26: Paste Fill   Distribution System Schematic Showing Paste Pumping Zones 1407 Modified from   AMC (2014) 16-52 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE 16.9.3 Distribution System Layout The   underground perspective view of the paste fill distribution system is   provided in Figure 16-27. Key points of the piping strategy are: One pump   plus installed spare at the paste fill plant    One booster pump plus spare to be installed near the ramp to the   Valley of the Kings Zone 1,345 m elevation    Main distribution pipeline in the Valley of the Kings decline and then   a bore to the West Zone Access Drift then to the Valley of the Kings   Zone  One sump to divert paste from the   pipeline during operation upsets.    Figure 16-27: Paste Fill Distribution System Schematic Not to Scale   Source: Pretivm (2020) 16.9.4 Manpower Requirements 16.9.4.1 Schedule The   mine is operated by a mining contractor with Pretivm supplying operational   oversight and technical service support personnel. As the Brucejack Gold Mine   site is remote, a reasonable crew rotation is required to attract the skilled   labour that will be necessary for operations. The Pretivm crews are on a   two-week-in, two-week-out rotation, and the contractor crews operate on a   three-week-in and three-week-out rotation. The working time per day is based   on an 11-hour shift; allowing one hour for smoke to clear after end-of-shift   blasting. However, the effective working time per day is less than 11 hours   considering travel time, daily safety briefs, and pre-start safety checks.   The effective working time per shift during production operations is nine   hours. 16-53 

    

 

TECHNICAL REPORT   ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001 |   MARCH 2020 | ISSUED FOR USE To operate an 11-hour shift, a variance has been   granted from the BC Government (to allow work over 8 hours per shift). The   current mine contractor has obtained such a variance for the work at the   mine. 16.9.4.2 Organization and Manpower The underground mining group is   organized into operational groups consisting of mining, logistics,   maintenance, and technical support with mining logistics and maintenance   under the contractor, and the operations contract management and technical   support under Pretivm. Table 16-16 shows the total personnel underground   required by the operational group currently at the mine at full steady state   production of 3,800 t/d. Initial loading will primarily be provided by the   mining contractor, with technical support and operations contract supervision   provided by Pretivm. Additional hires are personnel employed to compensate   for shortages due to vacations, absenteeism, and turnover. Table 16-16:   Manpower by Operational Group table continues... 16-54 Role Head Count Role   Head Count Mining Supervision (12) Pretivm Underground Superintendent 2 Mine   Captain 2 Operations Engineer 2 UG Supervisor 2 Safety / Training / First Aid   4 Contractor Supervision and Support (14) Superintendent 2   Engineers/Technicians 4 Administrator 2 Safety/Training 4 Expeditors 2   Development Crew (132) Contractor Development Shift Boss 4 LHD Operators 12   Jumbo Operators 12 Truck Operators 32 Face Screening 7 Water/Fuel Truck   Operator 1 Bolter Operators 21 Blasters 9 Pillar Strapping 8 Telehandler   Operator 4 Alimak Miners 4 Service Installers 9 Grader Operator 2 Materials   Support / Mine Cleanup 3 Shotcrete 4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 16-55 Role Head Count Role   Head Count Production Crew (110) Contractor Production Shift Boss 8 Backfill   Services / Bulkhead & Construction Crew 17 Long Hole Drillers 33 Mine   Maintenance (Pump/Sumps) 8 Blasters 8 Boom Truck/Services 1 Truck Operators   10 Water/Fuel Truck Operator 4 LHD Operators 17 Paste Watch 4 Maintenance   (66) Contractor Maintenance Superintendent 1 Welders 2 Master Mechanic 2   Warehouse 4 Mechanics 32 Lead Electrician 2 Mechanic Apprentices 8   Electricians 10 Tire Technician 2 Maintenance Planner 3 Technical Services   (64) Pretivm Technical Services Manager 1 Chief Engineer 1 Senior Engineer 3   Planning / Ventilation / Drill Blast Engineer 5 Chief Geologist 2 Mine   Planning & Scheduling 3 Senior Production Geologist 2 Surveyors 8   Production Geologist 7 Geotechnical Engineer 7 Junior Production Geologist 8   Geological Samplers 17 Total Personnel 398 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.1 Mineral Processing   17.1.1 Introduction The Brucejack Deposit mineralization typically consists   of quartz-carbonate-adularia, gold-silver bearing veins, stockwork and breccia   zones, along with broad zones of disseminated mineralization. Gold and silver   are the major economical metals contained in the mineralization. There is a   significant portion of gold and silver present in the form of nugget or   metallic gold and silver. The concentrator was designed to process gold and   silver ore at a nominal rate of 2,700 t/d with an equipment availability of   92% (365 d/a) using a combination of gravity concentration and conventional   bulk sulphide flotation. The Brucejack Gold Mine was successfully   commissioned from March to May of 2017, with the first gold pour on June 20,   2017. The process plant reached full operation in Q4 2017. Since then, new   test programs have been conducted to further improve the mill operation. In   2018, further throughput increase reviews and test work were conducted by   mill metallurgists and engineers, equipment suppliers, and independent   consultants to improve the mill operation in an effort to increase the mill   throughput to 3,800 t/d. Most of the mill upgrading has been completed,   excluding the installation of the third cleaner flotation cell and the new   flocculant system, which are currently being installed. As reported, the mill   was operated at 4,065 t/d in Q4 2019. 17.1.2 Mill Operation Data The process   flowsheet originally developed for the Brucejack Gold Mine uses a combination   of conventional bulk gravity concentration and sulphide flotation. The   gravity concentrate is refined in the gold room on site to produce   gold-silver doré by directly smelting the upgraded gravity concentrate. The   doré is shipped by air to precious metal refineries located worldwide for   further processing to produce refined metals for sale. The final flotation   concentrate is dewatered, loaded into customized bulk containers and trucked   to the transload facility in Stewart, BC. From there, the concentrates in   bulk form are shipped to international smelters or traders. A portion of the   flotation tailings is used to make a paste to backfill excavated stopes in   the underground mine, and the balance is stored in Brucejack Lake. Water from   the concentrate and tailings thickener overflows is recycled as process   make-up water. Treated water from the water treatment plant is used for mill   cooling, gland seal service, reagent preparation, and make-up water. In May   2017, ore was first introduced to the mill from the low-grade ore stockpiles   with a focus on ramping up tonnage throughout to design capacity. The first   gold was poured on June 20, 2017. On July 1, 2017, Pretivm declared   commercial production at the Brucejack Gold Mine. Table 17-1 lists the 2019   production data. 17-1 17.0RECOVERY METHODS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 17-1: Brucejack Mill   Production Data 2019 17.1.3 Flowsheet Development The process flowsheet for   the expanded mill (3,800 t/d throughput) is based on the existing operation,   new test work and simulations, as well as Tetra Tech’s engineering   experience. In 2018, mill throughput increase reviews were conducted by   Pretivm’s metallurgists and engineers, equipment suppliers, and independent   consultants through various supporting test work and simulations. The process   flowsheet used in the expanded mill is identical to the existing operation   flowsheet, as shown in Figure 17-1. The operation units include: One stage of   crushing located underground  A mill   feed surge bin with a live capacity of 2,500 t located on surface  A SABC primary grinding circuit integrated   with a gravity concentration circuit    Rougher flotation and scavenger flotation of the hydrocyclone overflow   (gravity separation tailings)  Cleaner   flotation on combined rougher and scavenger concentrates  Flotation concentrate dewatering  Flotation tailings dewatering circuits.  17-2 Time Mill Feed Tonnage Mill Feed Grade   Total Recovery Tonne t/d (g/t Au) (g/t Ag) (% Au) (%Ag) Q1 2019 295,122 3,279   8.7 13.3 96.8 85.6 Q2 2019 324,171 3,562 8.9 15.6 96.9 83.8 Q3 2019 309,754   3,367 9.1 14.7 97.0 85.5 Q4 2019 373,954 4,065 8.3 14.1 96.8 85.6 Total 2019   1,303,001 3,570 8.7 14.5 96.9 85.1 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 17-1: Simplified   Process Flowsheet RIIA AR Y CRUSHE R CONCENTRA -10 I I SI.Jt..·1E fROM   U'JDERGI'{QL \D PUMPBOX >-------------------------------------------------------I   FLOTATION L l .J=-4 DORE Source: Tetra Tech (2019) I'1\:I TETRA TECH 17-3   CYCLON e PRIMARY1f1""1u 11GR AVITY I I [.:!] \FEED 3, J GLEANeR   L__, SHA <ING TABLES u FILTE 'l PRESS SIAFI TI G FURNACE GOLD/SILVER   CONCENTRATE U = ""' I' cvCLONEj R::JUGf·ERROUGHOR S·AVFGFRbl CLE   ANER bl GLEANERCL2r·t: R FLOTATION FL::JTMICNFLO-ATIONSCAVENGE REANE FL OT.A   TION' tL TAILINGS THICKENE R t},C; Kfll.L PASf[ PLP.I\ff ( J ,D[ f1C?OU \ D)   H l.CFJAC < LAIC 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.1.4 Plant Design 17.1.4.1   Major Design Criteria The nominal throughput of the upgraded process plant is   3,800 t/d of ore at a mill availability of 92%. Table 17-2 outlines the major   criteria used to upgrade the process flowsheet. Table 17-2: Major Design   Criteria 17.1.4.2 Operating Schedule and Availability The upgraded process   plant is operated on two, 12-hour shifts per day, 365 d/a. The overall   availability of the underground primary crusher circuit is 60%. The grinding,   flotation, and gravity concentration availability is 92%. The gold room is in   operation during the day shift only. These availabilities allow for a   potential increase in processing rate, downtime for scheduled and unscheduled   maintenance of the crushing and process plant equipment, and potential   weather interruptions. 17-4 Criteria Unit Value Daily Processing Rate t/d   3,800 Operating Days per Year d/a 365 Operating Schedule - Two shifts/day; 12   hours/shift Mill Feed Grades – Average g/t Au 5 to 20 g/t Ag 5 to 200 % S   2.85 Primary Crushing (Underground) Crushing Availability % 60 Crushing   Product Particle Size, 80% passing mm 120 or finer Grinding / Flotation /   Gravity Concentration Availability % 92 Milling and Flotation Process Rate   t/h 172 SAG Mill Feed Size, 80% passing mm 120 or finer SAG Mill Grind Size,   80% passing μm 800 to 1,000 Drop Weight Breakage Parameter A x b 41.4   (ranging 29.1 to 78.7) Ball Mill Grind Size, 80% passing μm 100 Ball Mill Circulating   Load % 300 Bond Ball Mill Work Index – Average kWh/t 14.0 Bond Ball Mill Work   Index – Design kWh/t 16.6 Nugget Gold Recovery from Primary Grinding Circuit   - Centrifugal and Tabling Gravity Concentration 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.1.5 Process Plant   Description 17.1.5.1 Primary Crushing (Underground) The primary crushing   facility has an average process rate of 264 t/h at a crushing availability of   60% to meet the increased mill throughput of 3,800 t/d at a closed-side   setting of approximately four inches. The current primary crushing unit is   located underground and includes the following major units: Hydraulic rock   breaker  Stationary grizzly  Jaw crusher (150 kW)  Vibrating grizzly feeder  Associated dump pocket and belt   conveyor  Belt scales  A dust collection system.  The ROM ore is trucked from the underground   mine to the underground primary crushing facility. The particle size of the   jaw crusher feed is typically less than 700 mm. The jaw crusher reduces the   ROM material to 80% passing 120 mm or finer. The crusher product is   transported by a conveyor system from the underground primary crushing   facility to the SAG mill feed surge bin located on surface. The primary   crushing and conveying facilities are equipped with a spray water dust   suppression system to control fugitive dust generated during crushing and   conveyor loading. The crushing and conveying system are monitored through closed-circuit   television (CCTV) and can be controlled by the local control system or from   the process central control room located in the process plant. 17.1.5.2 Mill   Feed Surge Bin The SAG mill feed surge bin has a live capacity of 2,500 t.   The crushed product from the underground primary crushing facility is first   conveyed to the transfer tower, which is part of the portal building on the   surface. From there, it is further transported to the SAG mill feed surge   bin. The ore from the mill feed surge bin is reclaimed by two 1,067 mm wide   by 15,000 mm long apron feeders onto the SAG mill feed conveyor at a nominal   rate of 172 t/h. The stocking and re-handling system for the crushed ore   includes the following major components:    One jaw crusher discharge belt conveyor  Two belt conveyors located in the   underground and one conveyor located at surface to feed the SAG mill feed   surge bin  One SAG mill feed surge bin   with a live capacity of 2,500 t  Two   apron feeders, 1,067 mm wide by 15,000 mm    Local dust collection systems. 17-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The crushed ore conveyor   transfer points at the portal and at the SAG mill surge bin are equipped with   a dust collection system to control fugitive dust generated while   transporting the crushed material. 17.1.5.3 Grinding, Classification and   Gravity Concentration A SABC grinding circuit has been installed at the mine   site and incorporated with two centrifugal gravity concentrators to recover   gold/silver nugget grains that are liberated or partially liberated from   their host minerals. The upgraded primary grinding circuit has an average   feed rate of 172 t/h at a 92% availability to meet the increased mill   throughput of 3,800 t/d and maintain a target product size of 80% passing   approximately 100 μm. According to the new comminution tests and simulation   results (Section 13.0), the capacity should be readily achieved within the   current circuit by: Increasing the SAG mill critical speed  Increasing the SAG mill charge loading  Placing one of the two stand-by cyclones   into operation.  According to the   simulations, the grinding mills should be able to achieve approximately 4,240   t/d before the grind size needs to increase to coarser than 80% passing 90   μm. The two gravity concentrators (Model QS40) have a design unit capacity of   250 t/h. This arrangement also allows the two units to treat 100% of the ball   mill discharge at the increased operating rate. The grinding/gravity   concentration circuit includes: One SAG mill, 6,096 mm diameter by 3,048 mm   long (20 ft. by 10 ft.) (effective grinding length (EGL)), driven by a 2,013   kW VFD  One ball mill, 3,960 mm   diameter by 7,260 mm long (13 ft. by 23.8 ft.) (EGL), powered by a 2,013 kW   VFD  One hp 100 cone crusher  One 1.83 m wide by 3.66 m long vibrating   screen  Two 10-inch x 8-inch   hydrocyclone feed slurry pumps, each with an installed power of 250 hp  Six 381 mm hydrocyclones (gMax15-3123),   with five in operation and one on standby    Two QS40 centrifugal gravity concentrators and ancillary screens  Two shaking tables, one secondary Knelson   concentrator (CD12), one melting furnace, and related ancillary equipment in   the secured gold room  One particle   size analyzer  One online sampler.  17-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The crushed ore from the   surge bin is reclaimed onto the belt conveyor that feeds the ore to the SAG   mill. The SAG mill is equipped with 40 mm pebble ports to discharge the fine   fraction from the SAG mill. The SAG mill discharge is screened by a vibrating   screen, which has an opening of 8.0 mm (slot wide). The oversize from the   screen is transported by conveyor to the HP100 pebble crusher. The screen   undersize is discharged by gravity to the hydrocyclone feed pump box in the   grinding circuit. The ball mill is operated in closed circuit with   hydrocyclones and two centrifugal gravity concentrators. The product from the   ball mill is discharged into the gravity concentrator feed pump box. The   entire ball mill discharges report to the gravity concentration circuit. The   stream is then split into two and each stream feeds to a safety screen with   the undersize reporting to one of the centrifugal gravity concentrators. The   gravity concentrator tailings, together with the safety screen oversize, flow   by gravity to the hydrocyclone feed pump box where the gravity separation   tailings join with the SAG mill trommel screen undersize slurry. The blended   slurry in the pump box is pumped to the hydrocyclones for classification. The   hydrocyclone underflow returns by gravity to the ball mill. The circulating   load to the ball mill is approximately 300%. The particle size of the   hydrocyclone overflow, or the product of the primary grind circuit, is 80%   passing approximately 100 μm. The pulp density of the hydrocyclone overflow   slurry is approximately 33% w/w solids. Steel balls are manually added into   the mills on a batch basis as grinding media. Dilution water is added to the   grinding circuit as required. A particle size analyzer monitors and optimizes   the operating efficiency, in conjunction with an automatic sampling system   and the required instrumentation such as solid density, pressure, and flow   rate meters. 17.1.5.4 Rougher and Scavenger Flotation The pulp from the   primary grinding circuit is subjected to conventional flotation to recover   the free gold, silver, and their bearing minerals from the hydrocyclone   overflow. Flotation reagents are added to the flotation circuits as defined   through testing and the existing operation. The flotation reagents include   PAX as the collector and D250 as the frother. The mass recovery of the   rougher concentrate is approximately 15% of the flotation feed. The   concentrates produced from the rougher flotation circuit are sent to the   cleaner flotation circuit. The rougher flotation tailings are further floated   by scavenger flotation, along with the tailings from the first cleaner   flotation circuit. The scavenger concentrate returns to the head of rougher   flotation for re-processing or to the first cleaner circuit for upgrading.   Rougher and scavenger flotation are carried out at the natural pH level   (without slurry pH adjustment). The upgraded feed rate of the rougher   flotation circuit is 172 t/h. The rougher/scavenger flotation circuit   includes: Four 100 m3 rougher flotation tank cells Two 100 m3 scavenger   flotation tank cells.   The tailings   from the rougher scavenger flotation circuit are discharged to the tailings   thickener. Depending upon the mining operation requirements, the thickener   underflow is pumped either to the paste backfill surge tank for excavated   stope backfilling and/or to the tailings disposal surge tank prior to being   pumped to Brucejack Lake for storage. Automatic sampling systems installed   for the circuits, including the flotation feed, rougher scavenger tailings,   and final flotation concentrate, collect the samples required for process   optimization and metallurgical accounting. 17-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.1.5.5 Cleaner Flotation In   the current operation, the rougher and scavenger flotation concentrates   undergo three stages of cleaning by flotation in order to produce the final   gold-silver bearing concentrate. The feed rate of the cleaner flotation   circuit is estimated to be approximately 44 t/h. As per the planned upgrading   in 2018, to meet the increased mill feed rate, the existing second and third   cleaner cells need to be converted for the second cleaner flotation and   operate in series. A new 30 m3 flotation cell is required for the third   cleaner flotation. The third cleaner cell is currently being installed. The rougher/scavenger   flotation circuit includes: Four 15 m3 tank cells for the first cleaner   flotation Two 15 m3 tank cells for the first cleaner/scavenger flotation Two   15 m3 tank cells for the second cleaner flotation One 30 m3 tank cell for the   third cleaner flotation.     The   rougher concentrate together with the scavenger concentrate are initially   upgraded in the first cleaner tank cells. As an option, the current operation   can also direct the rougher-scavenger concentrate to the rougher flotation   head depending on the flotation feed mineralogy. Also, based on the   concentrate grade of the first rougher flotation cell, the rougher   concentrate can bypass the first cleaner flotation and report to the second   cleaner flotation directly. The first cleaner concentrate is pumped to the   second cleaner circuit, while the first cleaner tailings reports to the first   cleaner scavenger flotation cells for further concentration. The first   cleaner scavenger flotation concentrate is returned to the head of the first   cleaner flotation cell bank, joined with the rougher and scavenger flotation   concentrates and the second cleaner tailings. The first cleaner scavenger   flotation tailings are pumped back to the rougher scavenger flotation feed   box. The concentrate from the second cleaner flotation stage is further   upgraded by the third cleaner flotation with a new 30 m3 flotation cell; the   second cleaner tailings is pumped back to the first cleaner flotation. The   concentrate from the third cleaner flotation cell, the final concentrate   product, is pumped to the concentrate thickener. The third cleaner tailings   are recycled back to the head of the second cleaner flotation circuit. The   reagents used in the primary bulk flotation circuits are also added to the   three stages of cleaner flotation to float the target minerals. The cleaner   flotation processes are carried out at the natural slurry pH level. 17.1.5.6   Gravity Concentrate Upgrading/Refining The primary gravity concentrate is   further upgraded and refined in the gold room, which is located within a   security room and has 24-hour CCTV surveillance. The access to the gold room   is only for authorized personnel. For the increased plant feed throughput of   3,800 t/d, it is anticipated that the gold room treatment capacity is able to   meet the increased gravity concentrate production by extending the operating   time. Key equipment in the gold room includes:  One 1.8 m wide by 4.9 m primary gravity   concentration table  One Knelson CD-12   centrifugal gravity concentrator 17-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE One 1.7 m wide by 2.7 m   secondary gravity concentration table    One table concentrate dryer    Flux reagent storage  One flux   mixer  One 138 kW induction melting   furnace  One vault for storing doré and   table concentrate  One electrostatic   dust collector  One off-gas and dust scrubbing   system  Ancillary equipment, including   slag treatment devices.  The primary   gravity concentrate is pumped to the gold room for further upgrading by   tabling on the 1,800 mm wide by 4,900 mm long shaking table. The tailings   from the primary tabling is further processed by the CD12 centrifugal   concentrator and the table middlings is recycled back to the table feed surge   bin. The concentrate produced from the secondary centrifugal concentrator is   upgraded using a 1,700 mm wide by 2,700 mm long shaking table while the   centrifugal concentrator tailings are pumped to the hydrocyclone feed pump   box. The secondary table tailings are pumped to the primary table feed surge   bin. The concentrates from both the primary and secondary tables, which are   the final products, are dried and melted in the induction furnace to produce   gold-silver doré. The discharge from the furnace is poured into bar molds in   a cascade-casting arrangement. The gold doré bars are weighed, sampled, and   stored in the vault prior to being shipped to refineries. The concentrates   from both the tables are dewatered, dried in a dryer, then weighed and stored   in the vault prior to smelting. The existing wet scrubbing system is used to   clean the off-gas generated during the drying, calcination, mixing, melting,   and slag crushing operations. The equipment used for these processes are   equipped with hoods. Sufficient ventilation is provided in the gold room to   protect the operators. All clothes, gloves, and other safety equipment   necessary for high-temperature protection are provided to the operators   working in the secure area. 17.1.5.7 Concentrate Handling The concentrate   from the third cleaner flotation is thickened, filtered, and loaded into   customized bulk containers prior to being transported to off-site smelter(s).   The current concentrate dewatering system is expected to be able to handle   the increased tonnage with diluting the thickener feed to 15% w/w and using a   more efficient flocculant at recommended dosages. It is expected that the   existing concentrate filtration capacity is sufficient for the increased mill   feed rate with upgrading the filtration system, including adding two   additional filter plates. The concentrate dewatering/handling facility   includes the following equipment: One 5 m diameter high-rate thickener  Three thickener underflow slurry pumps, two   in operation and one on standby  One   concentrate filter feed stock tank (5,000 mm diameter by 6,000 mm high)  17-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE One tower-type pressure   filter with a total filtration area of 25 m2    One concentrate cake handling system.    The final flotation concentrate is pumped to the concentrate   thickener. Flocculant is added to the thickener feed well to aid the settling   process. The thickened concentrate is pumped to the concentrate stock tank.   The underflow density of the thickener is approximately 70% solids. The   concentrate stock tank is an agitated tank, which serves as the feed tank for   the concentrate filter. A tower-type press filter is used for further   concentrate dewatering. The filter press reduces the moisture content of the   thickener underflow to approximately 8%. The filter press solids are   discharged into a bulk container. The loaded containers are stacked in the   concentrate loading area prior to being loaded into vehicles with chained   tires and transported to the Knipple Transfer Station, then to Stewart, BC.   The concentrate is then transported in bulk by sea to international smelters   or traders. The process plant provides sufficient on-site storage capacity   for up to 10 days of production in the event of unexpected transportation   disruption. Additional secured storage is also provided at the Knipple   Transfer Station. The filtrate from the pressure filter is circulated back to   the concentrate thickener feed well as dilution water. The overflow from the   thickener is pumped to the process water tank or to the grinding circuit for   re-use as process water. 17.1.5.8 Tailings Disposal The final tailings is   pumped to an 18 m deep cone thickener where most of water is removed as   thickener overflow and re-used in operation. Part of the thickened tailings,   approximately 40 to 50% of the overall tailings, is pumped to the paste   backfill feed surge tank prior to feeding the paste plant for underground   mine backfilling. The remaining thickened tailings is pumped to Brucejack   Lake for storage. At an increased process plant feed rate of 3,800 t/d, based   on the completed test results and simulations, the existing 18 m tailings   thickener is capable of handling the capacity by using proper feed   conditioning, including feed dilution and the use of the optimum flocculant type   at recommended dosages. The projected solids density of the tailings   thickener underflow is approximately 65% by weight. The existing tailings   handling facility has the following equipment: One 18 m diameter deep cone   thickener  One 4 m diameter by 5 m high   disposal surge tank for the tailings that is discharged to Brucejack   Lake  One 11.0 m diameter by 11.6 m   high thickener underflow stock tank    Two thickener underflow positive displacement (PD) pumps, each with an   installed power of 20 hp  Two thickener   underflow recycle PD pumps, each with an installed power of 20 hp  Two tailings disposal pumps with an   installed power of 75 hp.  The   flotation tailings are pumped directly from the pump box in the flotation   circuit to the tailings thickener feed well where the tailings are diluted in   an inner dilution launder and flocculant is added to improve settling   efficiency. The thickener underflow is pumped to a 11 m diameter by 11.6 m   high thickener tailings stock tank. The thickened tailings are pumped to the tailings   disposal tank and then pumped to Brucejack Lake for storage. When the   backfill plant is in operation, the tailings are also pumped to the paste   plant fully or partially based on the paste plant requirement. The thickener   overflow is sent to the process water tank for re-use as process water. 17-10   

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.1.5.9 Reagent Handling and   Storage PAX and D250 are added to the flotation process slurry stream to   modify the chemical and physical characteristics of mineral particle   surfaces, and to enhance the floatability of the valuable mineral particles   into the concentrate products. PAX is shipped to the mine site in solid form.   A 20% reagent solution is made by mixing PAX with fresh water in a mixing   tank. The reagent solution is stored in a 1.50 m diameter by 1.50 m high   holding tank and added to the various addition points through metering pumps.   The PAX consumption is in the range of approximately 50 to 80 g/t milled.   D250 in liquid form is added directly into the flotation cells without   dilution through metering pumps. The dosage applied is approximately 20 g/t   milled. Flocculant is used as a settling aid for the flotation concentrate   and tailings thickening. The existing flocculant system is being replaced   with a larger unit, which is currently being installed, for the higher   process rate requirement. Solid flocculant is prepared in the standard manner   in a wetting and mixing system to a dilute solution of less than 0.2%   solution strength. The solution is stored a holding tank prior to being   pumped to the thickener feed wells. The flocculant dosages added to the   concentrate and tailings thickeners are approximately 15 to 20 g/t   concentrate and 60 to 80 g/t milled, respectively. Hydrated lime is used to   prepare an alkaline solution for scrubbing. Anti-scalant chemicals are   delivered in liquid form and added to the process water tank as required to   minimize scale build-up in the water pipelines and process equipment. This   reagent is added in undiluted form. 17.1.5.10 Assay and Metallurgical   Laboratory The assay laboratory, located at the Knipple Transfer Station, is   equipped with the necessary analytical instruments to provide all routine   assays for the mine, process plant, and environmental department. A   metallurgical laboratory is located in the mill to undertake the necessary   test work to monitor metallurgical performance and, more importantly, to   improve process flowsheet unit operations and efficiencies. 17.1.5.11 Water   Supply Two separate water supply systems are provided to support the   operations for the process plant: one fresh water supply system and one   process water supply system. Fresh Water Supply System Fresh water is   supplied to a fresh/fire water storage tank (10 m diameter by 11 m high) from   the water treatment plant or from Brucejack Lake. Fresh water is primarily   used for: Fire water for emergency use    Cooling water for mill motor and mill lubrication systems  Gland water for the slurry pumps  Reagent make-up  Process water make-up.  17-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The fresh/fire water tank is   equipped with a standpipe for fire water requirements. Wells supply water to   the mine site potable water supply system. The water is sanitized and stored   in potable water storage tanks prior to delivery to various service points   within the mill and camp. Process Water Supply System The overflow solution   from the tailings thickener is pumped to the process tank (8,000 mm diameter   by 8,000 mm high) and re-used in the process circuit. The water treatment   plant, which treats water from the mine (underground water), water collected   from the plant site, or from Brucejack Lake, as required, provides the   balance of the process water. 17.1.5.12 Air Supply The air system supplies   air to the following service areas:    Crushing circuit – An air supply system located underground supplies   high-pressure air for dust suppression and equipment services.  Flotation – Air blowers provide   low-pressure air for flotation cells.    Filtration circuit – Dedicated air compressors provide high-pressure   air for filtration and drying.  Plant   air service – Dedicated air compressors provide high-pressure air for various   services.  Instrumentation – Plant air   compressors provide service air that is dried and stored in a dedicated air   receiver. 17.1.5.13 Process Control and Instrumentation There is a central   control room in the mill office complex that can monitor and control plant   operations, including the underground crushing and conveying systems. CCTV   cameras are installed at various locations throughout the plant. Sampling and   Inline Analysis The process plant relies on the on-stream or in-stream   particle size analyzer and various flow rate and solid density meters for   process control. The analyzer and meters examine the various slurry streams   in the circuit. The on-stream particle size monitor determines the particle   sizes of the hydrocyclone overflows in the primary grinding circuit. Required   samples are taken in order to control hydrocyclone overflow particle size and   optimize the grinding circuit operations. Specific samples taken for   metallurgical accounting purposes include the flotation feed to the circuit,   the final tailings, the final concentrate sample, and occasionally the   middling products. These samples are collected on a shift-basis and assayed   in the assay laboratory. 17-12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 17.2 Annual Production   Estimate The process plant generates two products: gold-silver doré and   gold-silver bearing concentrate for the expected remaining LOM of 13 years.   Table 17-3 shows the annual metal production, which has been projected based   on the mining production plan outlined in Section 16.0 and the operation data   and metallurgical results outlined in Section 13.0. Based on the annual   average and excluding the last year of operation, the process plant is   estimated to produce approximately 6,261 kg Au and 4,618 kg Ag contained in   doré, and 67,874 t Au-Ag bearing flotation concentrate with average grades of   approximately 50 g/t Au and 887 g/t Ag. The arsenic content of the flotation   concentrates to be shipped to the smelter(s) is expected to be marginally   higher than the penalty thresholds outlined by most smelters and will require   further review. 17-13 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 17-3: Projected Gold   and Silver Production 17-14 Year Tonnage (kt) Mill Feed Grade Metal Recovery   to Doré and Flotation Concentrate Flotation Concentrate Doré Concentrate   Total Tonnage (dmt) Grade (g/t Au) (g/t Ag) (% Au) (% Ag) (% Au) (% Ag) (%   Au) (% Ag) (g/t Au) (g/t Ag) 2020 1,387 8.3 13.7 61.9 24.5 34.4 59.9 96.3   84.4 85,913 46.3 132.8 2021 1,387 8.6 9.3 64.5 35.4 32.0 53.6 96.5 89.0   81,858 46.8 84.9 2022 1,387 8.6 10.7 64.8 32.6 31.8 55.3 96.5 87.9 81,314   46.7 100.5 2023 1,387 8.6 11.4 65.5 30.6 31.1 56.3 96.6 86.9 79,974 46.3   111.3 2024 1,387 8.4 14.0 64.3 24.5 32.2 63.5 96.5 88.1 81,237 46.4 151.8   2025 1,387 8.6 51.8 62.8 7.5 33.7 82.2 96.4 89.7 81,885 48.8 721.1 2026 1,387   8.4 98.1 60.1 4.4 36.1 85.7 96.2 90.1 74,382 56.8 1566.0 2027 1,387 8.6 88.5   62.4 4.4 34.0 86.2 96.4 90.6 70,757 57.3 1496.3 2028 1,387 8.6 57.4 62.9 5.9   33.4 83.6 96.2 89.5 68,626 58.0 969.5 2029 1,040 8.4 110.1 61.4 4.0 34.9 87.2   96.3 91.2 53,554 56.9 1864.3 2030 1,040 7.4 122.1 57.5 3.6 38.5 87.6 96.0   91.2 59,296 50.2 1875.0 2031 693 7.2 159.3 55.5 3.1 40.4 88.1 95.9 91.2   40,495 50.0 2402.9 2032 380 7.0 231.0 55.3 2.6 40.5 89.7 95.9 92.4 23,065   46.9 3412.2 Total 15,637 8.4 59.6 62.3 6.4 34.0 84.0 96.3 90.4 882,357 50.4   887.1 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.1 Overview The Brucejack   Gold Mine is situated approximately 65 km north-northwest of Stewart, BC.   During construction from 2015 to 2017, a number of on-site and off-site   infrastructure were built to support the mining operation (Figure 18-1,   Figure 18-2, and Figure 18-3). The locations of operation and supporting   facilities and infrastructure were selected to take advantage of local   topography, accommodate environmental considerations, avoid avalanche   hazards, and ensure efficient and convenient underground crew shift change.   The Brucejack Gold Mine is accessed via a 73.5 km access road that intersects   Highway 37 at km 215, some 60 km north of Meziadin Junction. Electrical power   is supplied from the BC Hydro grid via a 57 km transmission line constructed   in 2016/2017, from the Long Lake Substation located 13 km north of Stewart,   BC. The transmission line is a 138 kV power supply line from the Long Lake   Hydro Substation to the Knipple Substation, with a 69 kV power supply line   from the Knipple Substation to the mine distribution centre. Facilities and   infrastructure are split between those at the Brucejack Gold Mine site and   those along the Brucejack Access Road. Infrastructure at the mine site   includes mill; camp; fire hall; warehouse; transmission power line power   distribution; emergency diesel power station (DPS); fuel farm; waste   management facilities, including incinerator; mobile equipment maintenance   shops; underground miners support facility; explosives storage; mine   ventilation and heating equipment; water management facilities; potable and   wastewater treatment facilities; ore storage; and waste rock/tailings storage   facility (WRTSF). Support facilities along the Brucejack Access Road are   located at the Knipple Transfer Station, Bowser Aerodrome, and Wildfire Camp.   The Knipple Transfer Station is the main hub for materials staging and   transfer to suitable vehicles for delivery to the Brucejack Gold Mine.   Facilities at the Knipple Transfer Station include the transmission line   stepdown substation, camp, cold storage building, potable water supply and   treatment, waste materials handling facility with incinerator, fuel storage   and distribution facility, paste binder silos, assay laboratory, emergency   vehicle storage, first aid facility, and sewage disposal system. The Bowser   Aerodrome is a 5,000 ft. long by 75 ft. wide gravel airstrip suitable for   such aircraft as a Beechcraft 1900, or similar speed and weight category   aircraft, or Twin-Otter type aircraft. Adjacent to Bowser Aerodrome were   Bowser, Bowser Temporary Construction, and Bowser West Camps. Bowser Camps   were used for mineral exploration crews and construction crews. The general   site was used for extensive laydown of equipment for mine and transmission   line construction and is currently used for mobile equipment, core, and spare   parts storage. Wildfire Camp is at km 1 on the Brucejack Access Road.   Wildfire Camp comprises a gate at the highway intersection to screen access,   a security building with gate for access control, camp, potable water well   with water treatment, sewage disposal system, and large laydown yard for   incoming and outgoing freight. Just west of Wildfire Camp (at km 1.5), there   is an area designated for paste binder storage and transfer. 18-1 18.0PROJECT   INFRASTRUCTURE 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 18-1: Brucejack Gold   Mine General Arrangement llrt:ols:Mr:JeLR.:!$ rwMI"ermn:c :r-oX!WikJ   I'1t:ITETRA TECH 18-2 Brucejack Lake ..k:.hrtson Ctfhlk (F::><:t)   icv+Nu:.n!W>I S..p 11 2J1''.:...t. ROck ::Jom Cr"l € BrJc-ojtJk Cold   lAine V nco-. , 6C V""X ll4 1604'• !>8-17&4 8.k'f !ZliC· yR   "-'"''"''f>otoiH lt "'--TI iiH....U I N<o!   -$-'1\ttct YIIt 1'1Jl --+---U1t em<r00Spe.;\>.'Et fJnfle   IJIIII4111lfl'bgnt.ure --'1'1P SIPEW AdLtrlk' 'lt',fW<lkD.m:> llrr¢Tc   al M--·-·S:llfltaY lll';ll"') 'fst! flkmo U trMte Ot ' .et   'oiTI'L..IeS!;l'lJ "OJ 200 Metere PRETIVM Ill PREll UM RESOURCES INC .   2l00-1C6Dunll'll.ll r StrHt '"""' Mine Site Generl!l Arrangement   I'" 1:4,UUUf""'11"'P'N M!l' 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 18-2: Brucejack Gold   Mine On-site Infrastructure Layout ....... llti U•')HEr ' t Wf..,.,   I'1t:ITETRA TECH 18-3 Bruc•j:lck Gold Mir.e Infrastructure (U1L1_.:l>.•   V"; -C•-1• -"' Cl41_.,__ Ut1•1 ..d,.,CII•'•*• --\Jr""   :c..·c '-":.q,-.,, 'AIII:• DJ•u..--......1 •--,..TN8T"'Erl   .-lt.::::J lo --;. C...(M .,, .........R l,',.,..,_._..---J+<r.C   ;;SJ"":;c-11!,-<W -··-It•"!'c::J HW.O:'l..o:T!' •   .....oC:Io .....,,.._.... "')----( c.J,.,t.J:::Jf   '"""" 'I o'" lt L.._ &<::·.p•s_!,.'.,"   'lo-""'l.l').rp _..,.._ "'...,••...,., ,.. 125 PRETIVM Ill   PRETIUM RESOURCES INC _ ll00-l(li5.$ o....n-,;, Sto-t .RC'o"l'll4   (to4')""""· Brucejack On..Site 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 18-3: Brucejack Gold   Mine Off-site Infrastructure Layout • ...rodBMoons • Con'munk:adon Towen Cl   Mo.tllofologblstation -Brucopck Ttar.rillion line LOO Segment - H hWI)' 37 /   37A .. - Granduc Road BlucAjlckGold MIM <20000 Source: Pretivm (2019)   ['n;ITETR 18-4 A TECH 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.2 Mine Site Surface   Infrastructure Mine site infrastructure (Figure 18-1) covers a compact area   due to the nature of the site terrain. Facilities are localized to three   general locations all in close proximity. Underground mine-related facilities   are located along the south side of Brucejack Creek in proximity to the West   Zone portal, the main access for personnel and vehicles. Also located along   the south side of Brucejack Creek are the fuel farm, emergency DPS, and   associated DPS pond/sump. Centrally located on the mine site are the mill,   fire hall, emergency vehicles, two phases of camp buildings, truck shop, and   the Valley of the Kings portal. East of the mill area waste handling,   warehouse and miscellaneous buildings, ore storage and overburden storage,   and waste rock dump are all located along the southwest shore of Brucejack   Lake. Outlier facilities include the potable water well and incinerator   located northwest of the main site, and the Valley of the Kings weather   station located south of the main site. Water collection and diversion   infrastructure (e.g., collection ponds and ditches, diversion channels,   high-density polyethylene (HDPE) pipelines, sumps, weirs) are present   throughout the mine site to appropriately manage water. 18.2.1 Mill Facility   Description The mill building houses equipment for the entire process   following delivery of ore from underground. The 3,800 t/d process flowsheet   (Section 17.0, Figure 17-1) outlines the following sequence: ore delivery   from the Valley of the Kings Zone via the conveyor system to the surge bin   located at the surface. The main surface processing circuits include:  Primary grinding circuit consisting of a   SAG mill, a ball mill, a pebble crusher, and a related cyclone pack  Gravity concentration and refining circuit   consisting of two centrifugal concentrators, two shaking tables, and one   centrifugal concentrator for recovering the gold and silver grains from the   tabling tailings; and one smelting furnace for production of doré  Rougher and scavenger flotation followed by   three stages of cleaner flotation to produce gold-silver concentrate  Concentrate dewatering system using one   high rate thickener and one tower-type filter press to dewater concentrate to   less than 10% w/w moisture; flotation concentrate is loaded into customized   containers prior to being shipped offsite; the bulk containers replaced the   previous bagging system in April 2019; concentrate in bulk containers is   trucked to Stewart, BC for transshipment by ocean freight to smelter(s)  Flotation tailings dewatering and   management system consisting of one deep cone tailings thickener, one   thickened tailings surge tank, and one tailings disposal surge tank;   thickened tailings is sent either to the tailings surge tank and then to backfill   paste preparation system prior to the underground mine or to the disposal   surge tank prior to being pumped to Brucejack Lake for deposition on the lake   bottom  Process water recirculation   system; both the overflows from the tailings thickener and the flotation   concentrate thickener are reused as process water. The mill building also   houses a metallurgical laboratory equipped with all necessary laboratory   equipment for metallurgical testing and control. A bulk gravity concentration   laboratory is under planning to prepare the assay samples for the mill feed   and infill drill samples. With the assay sample preparation procedure, the   grade control assay procedure is expected to significantly mitigate the   nugget effect on the gold and silver assay. The laboratory will process the   bulk samples through centrifugal concentrators after grinding. The gravity   concentrate and tailings will be assayed separately by fire assay procedure   to calculate head sample gold and silver grades. 18-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.2.1.1 Process Plant   Control A control system provides equipment interlocking, process monitoring   and control functions, supervisory control, and an expert control system. The   control system generates production reports and provides data and malfunction   analyses, including a log of all process upsets. All process alarms and   events are logged by the control system. Operator interface to the   distributed control system (DCS) is via PC-based operator workstations   located in the underground crushing, process plant, water treatment, and   paste plant area control rooms. Control rooms are staffed by trained   personnel 24 h/d. Operator workstations can monitor the entire plant site   process operations, viewing alarms, and controlling equipment within the   plant. Supervisory workstations are provided in the offices of the senior   metallurgists, as well as in the mine operations hallway. An additional operator   interface is located in the main camp boardroom and is used in emergency   situations. Field instruments used in the mill process include   microprocessor-based “smart” type devices. Instruments are grouped by process   area and wired to local field instrument junction boxes in each respective   area. Signal trunk cables connect the field instrument junction boxes to the   control system input/output cabinets. Intelligent-type MCCs are located in   electrical rooms throughout the plant. A serial interface to the control   system facilitates the MCCs’ remote operation and monitoring. Control systems   philosophy is primarily focused on crushing, concentrator, and remote   monitoring. For site-wide infrastructure (i.e., telephone, Internet,   security, fire alarm, and control systems), a fiber optic backbone is   installed throughout the plant site. A PC workstation is installed in the   main control room to monitor the underground and crushing operations and   conveying operations to the surge bin. The information is provided to the   mill process control system via serial or Ethernet gateway. System controls   include SAG feed conveyors (zero speed switches, side travel switches,   emergency pull cords, and plugged chute detection) and surge bin levels   (radar level, plug chute detection). To control and monitor all mill building   concentrator processes, three PC workstations are installed in the mill   building’s central control room. They control and monitor the following:   grinding conveyors (zero speed switches, side travel switches, emergency pull   cords, and plugged chute detection), SAG and ball grinding mills (mill speed,   bearing temperatures, lubrication systems, clutches, motors, and feed rates),   particle size monitors (for grinding optimization and cyclone feed), pump   boxes, tanks, bin levels, variable speed pumps, cyclone feed density,   thickeners (drives, slurry interface levels, underflow density, and   flocculent addition), flotation cells (level controls, reagent addition, and   airflow rates), samplers (for metallurgical accounting and flotation   optimization), gravity concentrators, pressure filter, load out, reagent   handling and distribution systems, tailings disposal to paste backfill or   tailings storage, water treatment, water storage (including underground sumps   and contact water pond (CWP)) and reclamation/distribution (including tank   level automatic control), air compressors, paste plant (vendor control   system), fuel storage, and vendors’ instrumentation packages. An automatic   sampling system collects samples from various product streams for online   analysis and daily metallurgical balance. Composite samples are generated for   each 12-hour shift and are sent for assay at the Knipple assay laboratory. A   particle-size-based computer control system is used to maintain the optimum   grind sizes for the primary grinding circuits. The particle-size analyzer   provides main inputs to the control system. 18-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Remote monitoring is achieved   through CCTV cameras installed at various locations throughout the plant,   such as the crusher conveyor discharge point, the SAG surge feed conveyer,   the SAG and ball mill grinding area, the flotation area, the paste plant, the   gold room, the concentrate handling area, and the tailings handling   facilities. The cameras are monitored from the plant control room. 18.2.1.2   Water Treatment Plants Water treatment is undertaken in three separate   facilities: operations water treatment plant (WTP), potable WTP, and   wastewater (sewage) treatment plant. 18.2.1.3 Operations Water Treatment   Plant The operations WTP, located in the mill building, treats underground   inflows and surface water from the contact water collection system, process   water, and water from Brucejack Lake. The operations WTP is capable of   treating up to 10,000 m3/d. The treatment process consists of the following   steps: suspended solids removal (via clarification, coagulation using ferric   sulphate and flocculation using silica sand and anionic flocculants),   dissolved metal precipitation and total metals removal (through hydrated lime   precipitation and ferric sulphate co-precipitation), fine solids filtration   (via 10 μm disc filters), and pH adjustment (using sulphuric acid or hydrated   lime). Sludge from this water treatment is mixed with tailings and deposited   in Brucejack Lake. Under 3,800 t/d production, it is estimated that following   cessation of mining, projected to be in 13 years, the operations WTP will   continue to operate for less than a year to achieve acceptable discharge   water quality. 18.2.1.4 Potable Water Treatment Plant The Brucejack Gold Mine   site potable WTP is located adjacent to the Phase 2 Camp. Raw water is pumped   from a groundwater well located approximately 1.5 km northwest of the camp   site to two raw water storage tanks. A booster pumping system withdraws raw   water from the storage tanks and pumps it through green sand filters, woven   canister filters (down to 1 μ) and through ultraviolet (UV) disinfection.   Distribution pumps transport the water to both the Phase 1 and 2 camps, as   well as the mill building. Potable water within the mill building is treated   in a similar manner (cartridge filters and UV disinfection) and is used to   supply the lunchroom, bathrooms, and safety shower/eye wash stations through   the mill. The Brucejack Gold Mine potable WTP currently supplies   approximately 75 m3/d based on an average usage rate of 200 L/d per person   and a camp population of 360 persons. The facility is sized to treat water   sufficient for a camp population of at least 720 persons. The potable water   well has more than enough capacity to provide 150 m3/d. 18.2.1.5 Sewage   Treatment Plant The Brucejack Gold Mine site sewage treatment plant consists   of two packaged C-75 Filterboxx treatment plant units, each designed to treat   up to 75 m3/d of wastewater, for a total current treatment capacity of 150   m3/d. The current treatment rate is an average of approximately 75 m3/d,   sufficient for 360 persons. The total treatment capacity is capable of   treatment for approximately double the current camp population. Sewage is   piped from the two camps and mine dry to the sewage treatment plant. Portable   bathrooms at the mine site that are not plumbed into the sewage lines are   regularly pumped out with a vacuum truck that offloads the raw sewage into   the main lift station, which feeds the treatment plant. Raw sewage is treated   via primary screens, biological aeration reactors, and biological membrane   filtration. The sludge from the sewage treatment plant is dewatered using a   rotary vane filter and dried prior to final disposal by incineration at the   on-site incinerator. 18-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The mine is authorized via   its Effluent Permit for an additional 25 m3/d treatment unit and can add this   if required. Effluent from these treatment plants is discharged into   Brucejack Lake in accordance with the mine’s Effluent Permit. 18.2.1.6   Non-potable Water Mill non-potable water requirements are supplied from the   operations WTP and the reclaim pump house located at Brucejack Lake. The   operations WTP treats underground mine water, surface contact water (via the   CWP), and process water from within the mill. The treated effluent is then   pumped into the fresh/fire water tank located in the mill. The fresh/fire   water tank is also supplied by the reclaim pump house. The operations WTP   supplies approximately 70% of the fresh water for the mill and the reclaim   pump house supplies 30% of the mill’s fresh non-potable water needs. Water is   pumped from the fresh/fire water tank through a distribution manifold within   the mill, which supplies water for use in gravity recovery, flotation, paste   plant, reagent preparation, gland seal water, and wash down hoses. The   fresh/fire water tank is approximately 785 m3 in volume and only the top 30%   is used for fresh water within the mill. The lower 70% of the tank volume is   used for fire protection water within the mill and camp buildings. 18.2.2   Mine Waste Management 18.2.2.1 Waste Rock and Tailings Storage Facility   (WRTSF) Waste rock and tailings deposition entails depositing tailings and   potentially acid generating (PAG) waste rock into Brucejack Lake, or as   underground mine backfill. Brucejack Lake is a deep natural glacier and snow   meltwater lake allowing for LOM subaqueous waste rock and tailings deposition   without the need for any engineered containment structures, including dams.   Waste rock from the underground mine is transported to surface and   temporarily stockpiled at the waste rock dump (WRD) platform site. Most of   this waste rock is almost immediately deposited 1 m or more below the WRTSF   surface water elevation via excavator (‘bailing’) or tele-stacker   (‘stacking’). Waste rock deposited into the WRTSF via these methods builds up   and eventually forms the WRDplatform, where some waste rock extends to or   above the normal WRTSF water level. This subaerially exposed PAG waste rock   is replaced with either non-PAG (NPAG) material or freshly excavated PAG   waste rock, or left with a 1 m water cover, such that surface-deposited PAG   waste rock is ultimatelysubaqueouslydepositedwith a minimum 1 m water cover   within the allowable two-year subaerial exposure period. Tailings are NPAG   and deposited in the deepest part of the lake via tailings discharge line or   used for paste backfill in underground mined stopes. The initial WRTSF design   is documented in SRK (2016). This report includes the WRTSF stability and   settlement analysis (SRK 2014, Appendix C), which takes into consideration   site-specific physical characterization of the lake bed sediments, the lake   bathymetry, and measured lake bed sediment thickness. The design includes   measured tailings rheological properties (SRK 2015, Appendix A), which   confirms that tailings material properties will perform the same or better   than lake bed sediments. SRK (2018) contains an updated WRTSF design   triggered by the requirement for increased waste rock and tailings volumes to   be deposited into Brucejack Lake. This updated design includes comprehensive   stability analysis of a critical section of the WRTSF considering leanings from   monitoring data collected since the start of dump construction. It therefore   represents an up-to-date evaluation of all site-specific data and confirms   that actual dump behavior is representative of the numerical analysis   completed. 18-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Prescribed stability   requirements are not available for subaqueous waste rock deposition in BC (or   globally). However, the Mined Rock and Overburden Piles Investigation and   Design Manual (BCMWRP 1991) can be used as a starting point to inform a   possible minimum acceptable factor of safety (FOS). The WRTSF design (SRK   2018) confirmed that physical stability of the Brucejack waste rock dump   results in inherently low FOS when compared to the British Columbia Mine   Waste Rock Pile Research Committee (BCMWRP) (1991). Fundamentally, it was   determined that the active dumping face of the Brucejack WRTSF remains in a   quasi-stable state with a FOS near unity for a period of weeks to months   depending on the thickness of the unconsolidated undrained and highly   variable lake bed sediments (and tailings), until enough pore pressure   dissipation has occurred to allow the WRTSF foundation to carry the load of   the waste rock and remain stable. Because the design analysis confirmed that   a conventional FOS approach, based on numerical analysis, would not allow for   construction of the WRTSF, the observational method (Terzaghi and Peck 1967; Peck   1969) was adopted as the design approach for the WRTSF. This method was   developed from the need to avoid highly conservative assumptions about ground   properties in geotechnical design when faced with unavoidable uncertainties   of natural ground conditions. It takes advantage of observations and data   gathered during construction to adapt the design to actual ground conditions   in an orderly and planned way. Implementation of this approach in the context   of the WRTSF requires the following: Conduct numerical analysis to establish   behavioral bookends. Develop monitoring requirements to allow behavioral   tracking. Develop and implement safe operating procedures for WRTSF   construction. Develop Quantifiable Performance Objectives (QPOs) to inform   safe operating procedures. Conduct ongoing monitoring and reanalysis as   necessary. Continuously revisit and update safe operating procedures as   necessary. As a result, strict operational controls were set to ensure safe   WRTSF construction. This rigorous dumping procedure allows for enough safe   preloading of the foundation, subject to continuous monitoring and review by   a qualified geotechnical site engineer, with ongoing oversight by the   engineer of record (EOR). This dumping procedure is independent of the lake   bed sediment (and tailings) thickness or strength, because it assumes that   the foundation cannot initially carry the load whether it is due to sediment   (and tailings) thickness or strength (or both). Waste rock and tailings   deposition is governed by the Operations, Maintenance and Surveillance (OMS)   Manual, the last version having been updated in March 2020 (SRK 2020).   Specifically, waste rock dumping is done in accordance with a standard   operating procedure (Brucejack Lake Waste Rock Disposal, Standard Operating   procedure (SOP) 011), which is an appendix to the OMS Manual. Pretivm’s   engineering team manages the day-to-day waste rock deposition, and follow-up   monitoring and surveillance following procedures outlined in the OMS Manual.   The OMS Manual has been developed in accordance with SRK’s design   recommendations and undergoes updates as necessary. All employees working on   the WRTSF are provided training on the OMS Manual, specifically the WRTSF   SOP. The required surveillance procedures for waste rock and tailings deposition   is explicitly outlined in the OMS Manual, as are the QPOs. 18-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE A daily report is produced by   the Pretivm on-site geotechnical engineers that outlines all activities   pertaining the waste rock dumping. This report is circulated internally to   Pretivm staff, including senior management, all off-shift geotechnical   personnel to ensure continuity, as well as to the EOR. If the EOR identifies   any anomalies or areas of concern based on the daily report, he reaches out   to the on-site geotechnical engineers. 18.2.2.2 Tailings Delivery The   tailings delivery system discharges thickened tailings slurry to the bottom   of Brucejack Lake (80 m deep) when not used for paste backfill (approximately   40 to 50% of the time). For discharge to the lake, the tailings slurry is   pumped to an agitated slurry mixing tank at approximately 65% w/w solids and   then diluted with water to a maximum 55% w/w at the nominal solids throughput   rate of approximately 180 t/h. The diluted slurry is pumped overland from the   mill building up to the air release station through one of the two 6 HDPE DR   17, then to Brucejack Lake, a distance of approximately 900 m, through two   pipes that have been upsized to 8 HDPE DR 17, and then underwater along the   suspended discharge lines for another 400 m to the discharge point. There is   one duty pump and one standby pump to permit an immediate switch over when   necessary. The pumps discharge the diluted slurry at a variable flow rate of   varying concentration, which depend upon the throughput and concentration of   tailings slurry entering the mixing tank. The mixing tank is typically   maintained at a constant level through the addition of water through a   control valve. There is a constant flow through the pipeline to prevent   blockage of the pipe through tailings deposition within the pipe. When the   thickened tailings are used in the backfill plant, flow is maintained with water.   Portions of the pipeline alignment are subject to avalanches, and those   sections of the pipeline are placed in a trench and backfilled to protect the   pipe. The pipeline is heat traced to prevent freezing in winter and has a   continuous downward slope from the mill building to the lake shore to ensure   that the line drains during shutdowns. The pipelines discharge a maximum of 7   m above the lake bottom, a Discharge Permit condition. The pipelines are   switched if the active pipe become unusable, such as if the back-pressure   approaches the upper operating range of the discharge pump, or if bathymetric   surveys indicate excessive accumulations at the pipe discharge site. Both   pipes are suspended on cables to allow for vertical and horizontal   repositioning over the LOM to ensure the pipe is not covered by tailings and   to meet permit conditions for vertical positioning above the lake bottom.   There are air/vacuum valves at the lake shore to prevent the possibility of   air entering the underwater section. A large volume of air entering the   underwater section could potentially float sections of the pipeline. The   valves function primarily during start-up and shutdown. 18.2.3 Mine Site   Ancillary Facilities 18.2.3.1 Accommodations There are two accommodation   complexes at the mine site: Phase 1 and Phase 2 camp complexes. The main   (Phase 2) camp complex is located approximately 100 m southwest of the mill   and can accommodate up to 327 persons. The Phase 2 camp complex features   common facilities such as kitchens, mess halls, recreation rooms, common   rooms, and offices. The older (Phase 1) camp complex is located 200 m south   of the mill and can accommodate up to 183 persons. Each dormitory module   contains dormitory rooms, washrooms with showers, and laundry rooms. The   older Phase 1 camp kitchen has been repurposed as a training center with   safety offices. 18-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.2.3.2 Solid Waste Handling   and Domestic Waste Incineration Camp and facilities waste are managed   following the Waste Management Plan and, with respect to incineration, the   Refuse Incinerator Management Plan and the Air Discharge Permit. Wastes are   initially separated and disposed into receptacles appropriate to each waste   stream and further sorted at the mine’s waste handling and sorting facility.   A batch-fed containerized incinerator system is designed to process up to   1,800 kg of mixed solid waste material generated at the mine site per day.   Solid waste includes mixed camp waste; non-hazardous solid waste consisting   of food-waste; kitchen waste, including packaging, cardboard, wood waste, and   kitchen grease; and general refuse. Clean or untreated wood waste is burned   at approved burn pits at the mine site following requirements specified in   the Waste Management Plan and the Air Discharge Permit. Recyclables are   separated at the time of disposal, further sorted as appropriate, then   transported to off-site recycling facilities. Hazardous wastes are deposited   in dedicated receptacles and taken to off-site licensed facilities for   disposal. Remaining materials requiring landfilling are transported to local   regional landfills as needed. 18.2.3.3 Power Supply and Distribution At the   Brucejack Gold Mine, 69 kV electrical power enters the mill via the   transmission line from the Knipple Substation. There, the voltage is further   stepped down from 69 to 4.16 kV via two 15/20/25 MVA oil-filled transformers   and distributed to the site via 4.16 kV rated switchgear. The rating for site   on a distribution end is 4.16 kV and further transformed to 0.6 kV for   smaller loads. The main mill and underground loads are fed via power cables   in cable tray and/or messenger cable hangers. The main substation is located   inside the mill. Power feeds to the mill building, camps, truck shops, and   underground are either underground buried services or surface run cables.   Within the mill, large loads are powered at 4.16 kV. Smaller loads are   powered at 600 V via switchgear and MCCs. VFDs and soft starters are employed   strategically to optimize process and energy performance. Underground buried   services provide power to outlying buildings. 18.2.3.4 Emergency Power   Generating Facility Emergency power is supplied from four 500 kW, 600 V   generators, located at the DPS, that supply a step-up transformer and feed   the E4C e-house. Additionally, there are two 1,450 kW, 4.16 kV diesel   generators that are also directly interconnected to the E4C bus. As well,   there are six 1,825 kW, 4.16 kV diesel generators that are interconnected   into the E4C e-house. The total emergency power for the mine site is 15.85   MW, which can adequately supply the mill, underground, and camp facilities   with sufficient power if the transmission line sourced power is interrupted.   A dedicated power system PLC is included in the E4C e-house. This PLC   controls the breakers for system synchronization of the generators. An   uninterruptable power supply (UPS) backs up the PLC and communications to   ensure reliable operations under all circumstances. The power system PLC   performs two important functions: load optimization / load shedding to ensure   line limits are not exceeded, while maximizing electricity use and power   control during emergency power operations to ensure correct sequencing and   operations of critical loads. The controls for the power house can be   activated via fiber optic through the mill electrical SCADA system, as well   as through a local SCADA system. If there is a loss of power, the system will   automatically start the generators to achieve operating temperature and the   E4C bus will be energized. 18-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Extensive bedrock exposures   and extremely thin and spotty soils result in very poor resistivity. As a   result, remote grounds have been constructed in addition to substation yard   grounding. 18.2.3.5 Fuel Supply and Distribution Diesel fuel, primarily for   mobile equipment, is stored in four 50,000 L double-walled tanks and one   45,000 L double-walled tank located at the mill site. The storage has   approximately six to seven days capacity, including allowance for auxiliary   equipment. The fueling station includes loading/unloading pumps and filters.   Aviation fuel is delivered in totes and barrels to both Brucejack and Knipple   camp sites. Gasoline for mobile equipment is stored in one 5,000 L   double-walled fuel tank located adjacent to the diesel fuel tanks. One 18,000   gal propane tank is located adjacent to the permanent camp facility. Two   18,000 gal and one 10,000 gal propane tanks are located near the West Zone   area. One 18,000 gal propane tank is located at the VOK area. 18.2.3.6 Water   Management System Surface water management is accomplished through a system   of diversion ditches to direct non-contact water around the core of the mine   site area. The Johnson Creek (East) Diversion directs water to Brucejack   Lake, while the Camp Creek (West) Diversion directs water to Brucejack Creek.   Contact water from within the mill and camp pads area is directed to the CWP   via collection weirs, ditches, sumps, pumps, and HDPE pipelines. The CWP is   primarily a water management facility that is used to store water and prevent   unwanted discharges into Brucejack Lake. The CWP acts as a reservoir where   water can be directed to the water treatment plant and/or to Brucejack Lake,   provided water quality concentrations are acceptable. If there is   insufficient process water available from dewatering the mine or the CWP   pond, then process water is pumped from Brucejack Lake. 18.2.3.7   Telecommunications A complete site-wide telecommunications system has been   installed comprising four relay microwave stations and one backup microwave   system, which include: VoIP telephone system for buildings, camps, and   offices  Emergency satellite communications   for critical voice and data needs    Ethernet cabling for site infrastructure and wireless internet   access  Very-high frequency (VHF)   two-way radio system with nine public channels  Four remotely located VHF repeaters  Satellite TV and Internet for employees at   all camps  Wireless access tower for   communications at the towers  Satellite   phones available for remote work or communications outside the normal area   limitations.  A pre-manufactured   trailer is used as an information management center (IMC) to house all   communications equipment. The IMC includes all heating, ventilation and air   conditioning (HVAC) equipment and a UPS. The site telecommunications are   linked to the site fiber optic backbone via the IMC. Two separate emergency   satellite communications systems with phone and data capabilities are   provided and are isolated in the main camp 18-12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE building. This system handles   emergency off-site contact in the unlikely event that the IMC and its vital   equipment are compromised, or the main microwave system is interrupted. The   microwave network towers are powered by multiple redundant power sources of   EFOY fuel cell, solar energy, and propane power generation. Power and network   traffic are also continually monitored to ensure proper maintenance routines.   Internal facilities / information technology (IT) and specialized vendor   support are contracted for the microwave system technical support. 18.2.3.8   Miscellaneous Buildings A metallurgical laboratory, located on two 20 ft.   containers inside the mill building, houses all necessary laboratory   equipment for metallurgical testing and control. The laboratory is equipped   with all appropriate HVAC and chemical disposal equipment as needed. The   warehouse facility, including cold storage, located at the mine site houses   consumable parts storage and conducts logistic support for inbound and   outbound freight. A medical clinic is located within the main camp and provides   routine and emergency first aid services. A fire hall houses emergency   vehicles, including ambulance, fire trucks, and rescue equipment. The mine   dry is part of the camp and can accommodate up to 350 people, each with   individual lockers and hanging baskets. The wicket and lamp rooms are located   in the main camp adjacent to the dry where underground personnel are picked   up by underground vehicles and transported to and from the underground mine.   A mill dry 3-level complex is being constructed between the mill building and   main camp. The facility includes a dry that will accommodate 160 persons, a   mine meeting/training room, and offices. A light vehicle/heavy equipment   maintenance shop is located along the road immediately east of the mill   building. The shop includes an oil water separator located on the north side   of the building. 18.2.4 Km 72 NPAG Quarry Construction aggregate for the mine   was sourced from the NPAG quarry located at km 72 on the access road near the   southeast corner of Brucejack Lake. Site investigations, which began in 2013,   determined that the porphyry rock mass was NPAG and subsequent sampling each   year of quarrying has confirmed that determination. Quarry material is used   for road capping, both on surface and in the mine, and to provide a working   surface on the waste rock dump for that portion of the waste rock dump above   the lake surface level. There is sufficient quarriable material for all   foreseeable mine needs. 18.3 Off-site Infrastructure Off-site infrastructure   (Figure 18-3) comprises the Brucejack Access Road from Highway 37,   transmission line, Bowser Aerodrome, Knipple Transfer Station Camp, and   Wildfire Camp. During construction, other camp infrastructure was located at   the Bowser site, but the accommodation and kitchen facilities have been   decommissioned. The exploration geological core logging/sampling facilities   have been relocated to the Knipple Site. 18-13 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.3.1 Transmission Line   Electricity for the Brucejack Gold Mine and Knipple Camp is provided from the   BC Hydro network. An interconnection to the provincial grid is located at the   Long Lake Hydro Substation, approximately 13 km north of Stewart. From the   Long Lake Substation, the 138 kV line proceeds northward for 1.5 km to a   control station, Brucejack Terminal, and then continues a further 42 km to   the Knipple Substation. The Knipple Substation reduces the voltage from 138   to 69 kV; the transmission line then carries on to Brucejack Camp and is   introduced into the mill where the main Brucejack distribution transformers   are located. The 57 km line was completed on March 31, 2017. 18.3.1.1   Transmission Line Operations, Maintenance, and Emergency Response The   transmission line is controlled via the main incoming breaker located at the   control station, Brucejack Terminal, 1.5 km north of Long Lake Substation.   The line section from Long Lake Substation to the control station is under control   of BC Hydro. The Brucejack Transmission Line, past Brucejack Terminal, is   controlled either through the Brucejack Camp control station or the Knipple   Substation. An operating procedure establishes the procedures and   communication protocols for operation of the transmission line to protect any   transmission line workers and the integrity of the BC Hydro system.   Maintenance of the Brucejack Transmission Line consists of visual inspections   along the transmission line, as well as periodic infrared surveys to look for   potential deterioration in splices or other energized components. This is   complemented with a periodic inspection of the transmission line towers, with   climbing inspections to ensure the functionality of all conductors, guy   wires, cross arms, and other transmission tower components. Emergency   response is also important to manage the risk to the transmission line, with   spare tower sections and other parts kept at Bowser Aerodrome to facilitate   rapid response and restoration in the event of extreme weather damaging the   transmission line. 18.3.2 Access Road The Brucejack Access Road is an   all-season, two-way gravel surfaced road that commences at Highway 37 at km   215 and travels generally westward to Brucejack Lake, a distance of 73.5 km.   The Brucejack Access Road is maintained throughout the year by maintenance   crews stationed at Knipple Transfer Station. Aggregate materials for road   maintenance are sourced from quarries located at km 10 and km 58. Regular   patrols are conducted in potential avalanche areas with avalanche control   measures in place. An 11.5 km section of road, from km 59.5 to km 71,   traverses the main arm of Knipple Glacier. The glacier toe has receded about   1 km and melted at least 100 m vertically since the route was pioneered by Newhawk   in the 1980s. In 2012, when Pretivm reactivated the route, a new ramp was   developed onto the ice but continued melting has required further road   development off the glacier. A new 600 m section of road was activated on the   south side of the glacier in 2019 to bypass the lowermost portion of the   glacier road. Unlike other glaciers in the area, the Knipple Glacier is   generally free from large crevasse fields that would present a difficult and   hazardous route to vehicles and equipment. It does contain crevasses and mill   holes (moulins) large enough to present hazards to all-terrain vehicles or   personnel on foot. These hazardous crevasses and mill holes become   increasingly visible throughout the summer as winter snows melt. Seracs, or   ice cliffs, are not present along the immediate travel route. Glacier travel   guidelines and glacier emergency response plans have been developed and   implemented by Pretivm. Personnel on foot are not allowed to traverse the   glacier unless for a specific task related to road maintenance or 18-14 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE monitoring. Only specially   trained persons are allowed to exit vehicles on the ice. These personnel   operating on the glacier receive additional safety training and are issued   additional personal protective equipment such as rescue harnesses, avalanche   beacons, rope rescue equipment, and avalanche rescue equipment. 18.3.3   Knipple Transfer Station Facilities The Knipple Transfer Station facilities   include a camp with offices; potable water well with treatment system;   maintenance and emergency vehicle building; covered storage facility,   including cold storage, fuel storage, and dispensing system; helipad; waste   handling facility with an incinerator, assay laboratory, paste binder silos,   sewage treatment by septic systems; transmission line substation; exploration   core logging and splitting facility; and laydown area as shown in Figure   18-4. All deliveries to and from the mill site report to this facility for   intermediate storage or transfer to a different vehicle before delivery to   the mine or off site. Figure 18-4: Knipple Transfer Station 18.3.3.1 Camp The   camp is sized to accommodate 177 people, complete with kitchen, recreation,   dormitories, potable water treatment system, and a sewage treatment system.   Offices are included in the camp to manage the shipping and receiving of   goods. An emergency diesel generator provides power to the camp in case of transmission   line power interruption. A wireless system provides communications. Knipple   Camp facilities include a first aid / emergency vehicle parking building, a   cold storage / maintenance building, storage in sea can containers, and a   waste handling facility with incinerator. 18-15 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.3.3.2 Fuel Storage Fuel is   delivered to the Knipple Transfer Station and then stored in tanks before   transshipment to the Brucejack mine site, except for propane, which is   delivered directly to the mine. Storage facilities comprise one 150,000 L and   one 10,000 L diesel storage tanks, one 10,000 L gasoline tank, and propane in   30,000 L, two 8,000 L, and two 4,000 L tanks. Diesel fuel, primarily for   mobile equipment, is stored in one 150,000 L double-walled tank located at   the laydown area. Aviation fuel is stored in one 35,000 L double-wall tank.   The fueling station lies on a lined pad and includes an oil water separator,   a receiving pump, a strainer, and delivery pumps and filters. 18.3.4 Bowser   Aerodrome Bowser Aerodrome comprises a 5,000 ft. long by 75 ft. wide gravel   airstrip with an apron for aircraft parking. The aerodrome is located 2 km   east of Knipple Lake at 1,424 ft. elevation. The airstrip is shown in Figure   18-5. Figure 18-5: Bowser Aerodrome The airstrip was constructed at the site   by expanding and improving an existing gravel airstrip to provide a safe and   maintainable facility for chartered air traffic. It is available to provide   air service by chartered flights to and from the mine. Currently, the   personnel transportation between Brucejack Gold Mine and Smithers/Terrace, BC   is facilitated by chartered bus service. However, routine crew changes by   chartered air service is under study. Personnel would be transported from the   aerodrome to the mine camp by bus. 18-16 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The passenger aircraft used   in the initial design of the aerodrome was the Beechcraft 1900; however, the   design width was not completed nor were all approach/departure obstacle   clearing requirements met. Expansion of the runway to 100 ft. width and 5,500   ft. length with lighting and apron up-grades is under study to allow AGN IIIA   class aircraft, such as the DE Havilland Dash 8 turboprops, to use the   aerodrome. Obstacle removal is planned to alleviate the requirement to   displace runway 06 threshold. Regular maintenance, provided by road   maintenance personnel and equipment, permit year-round operation. 18.3.4.1   Maneuvering and Movement Surfaces (Runway and Apron) The runway and apron   surfaces are granular and suitable for turbo-prop aircraft. The runway   surface is 1,643 m (5,392 ft.) long and 23 m (75 ft.) wide and oriented   magnetically to correspond to the runway designations 06-24. Runway 06   (western approach direction) has a displaced threshold, elevation 1,445 ft.,   that is 364 m (1,195 ft.) from the west end of the airstrip. Runway 24   (eastern approach direction) threshold, elevation 1,440 ft., is located 60 m   (198 ft.) from the runway’s eastern end. The runway includes a 7.5 m (25 ft.)   graded area along each runway edge. The aircraft parking apron is located on   the south side of the runway at runway 06 displaced threshold and has been   sized to allow two Beach 1900 sized aircraft to maneuver and park. All   granular surfaces are treated with water for dust reduction. 18.3.4.2   Aerodrome Equipment Requirements A weather station is located just east of   the aerodrome and a ceilometer and altimeter are located at the aerodrome. A   trained radio operator at site communicates with aircraft prior to arrival   and is available after the flights have departed. This allows the operator to   relay weather and altimeter information to the pilots prior to, during, and   after departure (in case an emergency return is required). 18.3.5 Wildfire   Security and Camp The Wildfire Camp (Figure 18-6) is located at km 1 on the   Brucejack Access Road. Facilities include a gate at the Highway 37 junction   to screen access and a security building with a gate at the eastern side of   Wildfire Camp to control access and importation of banned substances and   fishing and hunting equipment. The security screening is to prevent   unauthorized departure with gold. Screening of vehicles and equipment for   invasive plant species is also undertaken at Wildfire Camp. All traffic   entering or exiting the Brucejack Access Road must report to this facility.   Access to/from the mine is controlled by the security personnel at site. The   camp area includes a large laydown area for incoming and outgoing freight   vehicles. Wildfire Camp is sized to accommodate 23 people, complete with   kitchen, dormitories, potable water well and pumphouse, potable WTP, and a   septic field for sewage disposal. For bear protection, the camp dormitories,   dry, and kitchen buildings are enclosed with an electric fence with gates for   pedestrians and service vehicles. 18-17 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 18-6: Wildfire Camp   18.4 Site Geotechnical Assessment This section is reproduced from the 2019   Technical Report. The geotechnical engineering assessment for the Brucejack   Gold Mine site has included several subsurface investigation programs   completed over the past decade. The regional and local geologic conditions   near the plant site are well understood based on surface mapping and sampling   of overburden soils and bedrock. The geotechnical engineering parameters that   were recommended for inclusion in the earthworks design and foundation   analysis at the Brucejack, proved satisfactory in the preparation of Issued   for Construction documents in 2016-17. Construction Record Reports for   earthworks documented that the design intent of the drawings and   specifications were met at the Brucejack Gold Mine. Further expansion will   require only site-specific recommendations for any proposed expansion   facilities as there is a large volume of site investigation and construction   records from the main plant available. 18-18 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 18.5 Avalanche Hazard   Assessment An avalanche hazard assessment of the mine site, Brucejack Access   Road, and transmission line route was presented in the 2014 FS (Ireland et   al. 2014). Generally, this hazard assessment remains unchanged other than for   the section of access road constructed in 2019 from 59 to 59.5 km. In   summary:  The avalanche season for   infrastructure below 1,000 m elevation is generally from November to May,   while for elevations above 1,200 m the season is from October to June, or if   cool, wet conditions persist avalanches can occur in summer months. Snow   avalanches generally occur in areas where there are steep open slopes or   gullies, and deep (more than 50 cm) mountain snow packs. Risks associated   with avalanches are normally due to exposure to the high-impact forces that   occur, as well as the effects of extended burial for any person caught in an avalanche.   Avalanches may reach speeds up to 60 m/s (200 km/h). Impact pressures from   dense flows are much greater than the powder component due to the density of   the snow.  An avalanche path generally   consists of a starting zone, a track, and a runout zone. Avalanches start and   accelerate in the starting zone, which typically has a slope incline greater   than 30°. Downslope of the starting zone, most large avalanche paths have a   distinct track in which the slope angle is typically in the range of 15 to   30°. Large avalanches decelerate and stop in the runout zone where the   incline is usually less than 15°. Smaller avalanches may decelerate and even   stop on steeper slopes (15 to 24°).    Avalanche frequency is the reciprocal of avalanche return period and   is typically referred to as an order of magnitude ranging from 1:1 (annual)   up to 1:300 (1 in 300) years. Each winter the probability of an avalanche   with a specified return period is constant; however, the frequency depends   upon snow supply, decreases with distance downslope in the track, and runout   zone and varies from year to year.    Destructive potential of an avalanche relates to the magnitude of an   avalanche. In general, large destructive avalanches occur less frequently,   while smaller ones occur on a more regular basis. The spacial relationship of   infrastructure to the location along an avalanche path will affect the   destructive potential. A further distance from the toe of an avalanche will   result in less risk and frequency of that risk.  Prior to construction, 15 avalanche paths   or hazard areas were estimated that potentially could reach infrastructure or   access roads, and many of those on an annual basis. These avalanche hazards   were avoided wherever possible. At the mine site, there remains a risk of   avalanches along the Brucejack Access Road between the NPAG quarry and the   waste management facility on the eastern side of the mine site. There are   also avalanche hazard zones along the Brucejack Access Road, particularly at   km 44 and between Knipple Transfer Station and the ramp onto Knipple Glacier.   In the km 44 area, remote avalanche control systems are installed to trigger   avalanches at controlled times in order to avoid significant likelihood of   large avalanche development. Remote avalanche control systems are also   installed along the new section of Brucejack Access Road from 59 km to the   ramp onto Knipple Glacier where a number of potential avalanche paths were   identified (Gould and Campbell, 2019).    Pretivm has full time mountain safety technicians who monitor   avalanche risk, develop hazard ratings for the Brucejack Access Road by   specific sections, and release hazard bulletins with avalanche ratings for   those road sections and glacier hazard ratings for travel on the glacier. The   mountain safety technicians regularly survey the ice road and work with road   maintenance to ensure safe travel on the ice. 18-19 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 19.1 Markets The Brucejack   Gold Mine produces doré and flotation concentrate, which contain both gold   and silver. The doré is shipped to precious metal refineries located   worldwide for further processing to produce refined metals for sale. The   concentrate is sold to international smelters or traders in concentrate form.   The concentrates is exported out of Stewart, BC in bulk form. Gold and silver   prices have fluctuated significantly. Table 19-1 shows the spot gold and   silver prices (as of March 4, 2020) together with the last two-year and the   last five-year average prices. Table 19-1: Gold and Silver Prices   Note:(1)Gold and silver price on March 4, 2020. 19.2 Smelter Terms The   following smelter terms are reflected in the doré refinery and/or concentrate   sales contracts that Pretivm currently holds at the time of this Technical   Report. The related charge rates are within the industry normal rates. The   terms are summarized as follows:    Gold-silver doré: - Gold and silver – pay approximately 99% of   gold and silver content. Gold is refined at the refineries and sold at the   spot market and subject to treatment charges, and other agreed deleterious   charges are deducted from the proceeds of silver sales to the   refineries.  Gold-silver concentrate:   -Gold and silver – approximately 95 to 97% of gold depending on the   gold contents and approximately 85% of silver content. Industry normal   treatment and refining charges are applied for payable metals. A penalty   charge for arsenic in the concentrate is charged over certain agreed upon   levels. 19.3 Concentrate Transportation Concentrate are transported to the   Stewart Bulk Terminal (SBT) in customized bulk containers (maximum capacity   of approximately 23 t). The containers are designed to have an openable lid   on top and hinged doors on the side. Containers are loaded at the Brucejack   Gold Mine site and trucked down to the Knipple Transfer Station where a   third-party trucking company further transports them down to the SBT. From   the SBT, the concentrate is exported to international customers in bulk   vessels. The estimated concentrate transportation cost is US$138.38/wmt of   concentrate, including ocean freight to Asian destinations at current market.   19-1 Metal Unit Spot(1) Two Years Three Years Gold US$/oz 1,641 1,353 1,328   Silver US$/oz 17.2 16.0 16.4 19.0MARKET STUDIES AND CONTRACTS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 19.4 Mining Development   Contracts Underground mining at the Brucejack Gold Mine is currently   completed by Procon. This work includes lateral and ramp development, long   hole drilling and blasting, mucking, hauling to the underground crusher, and   backfilling. Mine planning is conducted by Pretivm employees who oversee the   execution of the mining done by Procon. 19-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.1 Environment, Social and   Sustainability 20.1.1 Corporate Policies, Guiding Principles and Criteria   20.1.1.1 Mine Operations Philosophy Pretivm is committed to continuing to   operate the Brucejack Gold Mine in a sustainable manner and according to the   guiding principles in its corporate Social, Environmental, and Health and   Safety policies. Every reasonable effort has and will continue to be made to   minimize or prevent potential long-term adverse environmental effects and to   ensure that the mine provides lasting benefits to local Indigenous and other   communities while generating substantial economic and social advantages for   shareholders, employees, and the broader community. Pretivm is focused on   ensuring that the safe, successful operation of the Brucejack Gold Mine   benefits the Province of British Columbia, and in particular, the Nisga’a   Nation, Tsetsaut Skii km Lax Ha First Nation, Tahltan Nation, and the   communities of Gitlaxt’aamiks, Gitwinksihlkw, Laxgalts’ap, Gingolx, Dease   Lake, Telegraph Creek, Iskut, Stewart, Terrace, Smithers, Hazelton, and New   Hazelton. Pretivm is committed to sustainable resource development, which   balances environmental, social, and economic interests. Pretivm will continue   to comply with regulatory requirements and to apply technically proven and   economically feasible methodologies to protect the environment throughout   mining, processing, and closure activities. 20.1.1.2 Environmental Management   System Environmental management is a corporate priority. Pretivm developed a   comprehensive Environmental Management System (EMS) as part of its   environmental assessment certification and major permits applications, implemented   this during construction, and will continue to do so during mine operations   and closure. The Brucejack Gold Mine approved EMS, including 20 component   plans required by the mine’s Environmental Assessment Certificate (EAC   #M15-01) and additional plans approved via other mine authorizations, is   integrated into all aspects of mine operations. Environmental management is   implemented on a basis of continual improvement. All of the component plans   are considered to be live documents and undergo internal review a minimum of   annually in accordance with regulatory requirements. Component plans are   modified as appropriate based on these reviews and as required based on   approved mine plan or environmental program modifications. Revised component   plans are included in the mine’s annual report for its BC Mines Act (M-243)   and Environmental Management Act Permits (PE-107835 and PA-107025) and   distributed to applicable BC provincial regulatory agencies, the Nisga’a   Nation through the Nisga’a Lisims Government, the Tsetsaut Skii km Lax Ha   First Nation, the Tahltan Nation (as represented by the Tahltan Central   Government), and to the State of Alaska Department of Natural Resources.   Updated versions of the EMS component plans are also provided to BC EAO. 20-1   20.0ENVIRONMENTAL STUDIES, PERMITTING AND SOCIAL OR COMMUNITY IMPACT 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Component plans developed and   implemented pursuant to the EAC are as follows: Aboriginal Consultation   Plan  Air Quality Management Plan  Ancillary Infrastructure Decommissioning   and Reclamation Plan  Aquatic Effects   Monitoring Plan  Avalanche Safety   Plan  Chemicals and Materials Storage   and Handling Plan  Economic and Social   Effects Mitigation Plan  Heritage   Management Plan  Health Services   Monitoring Plan  Invasive Plants   Management Plan  Metal Leaching / Acid   Rock Drainage (ML/ARD) Management Plan    Mine Emergency Response Plan    Operation, Maintenance, and Surveillance Manual: Brucejack Gold Mine   Subaqueous Waste Rock and Tailings Deposition    Operation, Maintenance, and Surveillance Manual: Water Management   Plan  Reclamation and Closure Plan  Soils Management Plan  Spill Response Plan  Traffic and Access Management Plan  Vegetation Management Plan  Waste Management Plan  Wildlife Management Plan.  Additional management plans required for   other authorizations or completed internally include: Geohazards Management   Plan  Chromium Management Plan  Ground Control Management Plan  Health and Medical Services Plan  Nitrogen Management Plan  20-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Refuse Incinerator Management   Plan  Surface Erosion Prevention and   Sediment Control Plan  Potable Water   Management Plan  Construction   Environmental Management Plan (applied to Construction phase only).  Pretivm’s Environment and Regulatory   Affairs department personnel implement and/or direct, provide training as   appropriate, and monitor the implementation of federal and provincial   environmental requirements under the mine’s authorizations (BC EAC,   Environmental Impact Statement (EIS) Decision Statement, permits, licenses,   tenures) and EMS. Health and safety (including medical, security, and   avalanche safety) requirements of applicable component plans are implemented   and/or directed by the mine’s Health and Safety Department. Engineering   related requirements, including geotechnical and geohazards, are led by the   Technical Services Department. Standard Operating Procedures (SOP) have been   developed as appropriate for the various plans and are implemented by   personnel trained in their use. 20.1.1.3 Traditional Knowledge Pretivm   respects the traditional knowledge of the Indigenous peoples who have   historically occupied or used the Project area. Pretivm recognizes that it   has significant opportunity to learn from people who have generations of   accumulated experience regarding the character of the plants and animals, and   the spiritual significance of the area. Traditional knowledge informs   planning for various aspects of the mine, including planning and design for   future changes to the mine plan as may be applicable. Pretivm is committed to   an engagement process that continues to invite and consider input from people   with traditional knowledge in the area. 20.1.1.4 Ecosystem Integrity Prior to   about 1980, the local ecosystem was relatively undisturbed by human   activities, although it was not static. Glacier retreat and relatively recent   volcanic activity (within the last 10,000 years), along with landslides,   debris flows, and snow avalanches, have and continue to modify the landscape.   In the 1980s and through the 1990s, Newhawk Gold Mines Ltd. completed mineral   exploration, including advanced underground exploration, at Brucejack. In   2008, Silver Standard Resources began surface exploration of Brucejack.   Pretivm began major exploration programs starting in 2011, leading to mine   construction in 2015. The Brucejack Gold Mine was designed and constructed   with a minimal disturbance area (surface disturbance of approximately 50 ha   for core infrastructure at the mine site). Pretivm is committed to retaining   current ecosystem integrity as much as possible during mine operations and   closure. This objective is being met by:    Minimizing the mine infrastructure development footprint, and   reclaiming areas that are no longer required for mine operations  Implementing rigorous surface water   management practices to reduce erosion and sediment transport of easily   erodible soils  Avoiding adverse   effects, where feasible  Minimizing   and/or mitigating unavoidable adverse effects. 20-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Following completion of   operations, the mine and its supporting infrastructure will be closed and   reclaimed to the approved end land uses in accordance with the Reclamation   and Closure Plan. Objectives of the Reclamation and Closure Plan include   returning disturbed areas to a land use meeting the average level of   capability that existed prior to project development, where practical, and for   the end configuration to be consistent with pre-existing ecosystems to the   extent feasible. 20.1.1.5 Biodiversity and Protected Species Pretivm remains   committed to making every reasonable effort toward maintaining biodiversity   in the area of the mine. Biodiversity is defined by the BC Ministry of   Forests, Lands and Natural Resource Operations and Rural Development   (MFLNRORD) as “the diversity of plants, animals, and other living organisms   in all their forms and levels of organization, and includes the diversity of   genes, species, and ecosystems, as well as the evolutionary and functional   processes that link them” (MFLNRORD 1995). Maintenance of biodiversity is not   an isolated effort, but an integral part of project planning (mitigation and   monitoring), environmental effects analyses, and achievement of environmental   protection and mitigation goals. This approach was implemented throughout the   mine’s environmental assessment and permits applications processes and   subsequent development, and will continue to be implemented through   operations. 20.1.2 Social Setting 20.1.2.1 Socio-economic Setting Northwest   BC is a sparsely populated and relatively undeveloped region of the province.   Many of the smaller communities have predominantly Indigenous populations that   are distant from one another as well as from the main regional centers of   Smithers and Terrace. Nationally, the Indigenous population is one of the   fastest growing populations, increasing at four times the rate of the   non-Indigenous population since 2006. This suggests that the Indigenous   population in this region will continue to represent a significant segment of   the regional population into the future. The Brucejack Gold Mine is located   in the Regional District of Kitimat-Stikine. The mine’s area of influence is   generally considered to be northwest BC, inclusive of communities from the   Nass Valley and Terrace to Smithers, Stewart, and as far north as Dease Lake.   Primary resource industries, principally mining and forestry, are the   mainstay of the regional economy. The forest industry declined in recent   decades, which has significantly affected the economy and led to a steady   decline in the regional population. As is typical of resource-dependent   economies, communities in the region have experienced multiple cycles of   “boom and bust” associated with mining and resource extraction, with the   attendant population peaks and troughs. However, announcements of major   projects (including mining and liquefied natural gas (LNG)) have drawn   workers to the region, potentially leading to population growth in   communities such as Smithers and Terrace. Transportation infrastructure in   northwest BC is limited. The primary transportation corridors are Highway 37   (north to south) and Highway 16 (east to west). Air transportation hubs   include the Northwest Regional Airport in Terrace, which serves the   communities of Terrace and Kitimat (including daily flights to Kelowna,   Vancouver, Victoria, and Prince George), the Smithers Regional Airport in   Smithers (with flights to Vancouver, Dease Lake, Prince George, and other   communities), and the Prince Rupert Airport in Prince Rupert (with scheduled   flights to Vancouver). 20-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Community and socio-economic   impacts of the Brucejack Gold Mine are favourable for the region, with many   long-term opportunities created for local and regional workers. Pretivm is   committed to hiring workers from northwest BC; as of December 2019, 51% of   Pretivm’s direct workforce of 741 employees were residents of the region and   31% self-identified as Indigenous. The total workforce amounted to 1,201, of   which 460 were employed as on-site contractors. These rotational jobs allow   workers to continue living in their home communities and have likely helped   to reduce and possibly reverse the out-migration to larger centers. Pretivm   has and continues to work actively with Indigenous groups (including the   Nisga’a Nation, Tsetsaut Skii km Lax Ha First Nation, Tahltan Nation, and   Gitanyow Hereditary Chiefs) and representatives of local communities to   maximize benefits through employment and business opportunities, training,   and skills development programs. Through multiple initiatives, including   working with local training organizations and holding career fairs throughout   the region, Pretivm is committed to enhancing local benefits and improving   economic growth in the region. Pretivm also owns a warehouse and office in   Smithers where it bases its off-site supply chain management, warehousing,   travel, and some senior environmental and permitting personnel; approximately   20 employees work at this location. Pretivm reached a Cooperation and Impacts   Benefits Agreement with Nisga’a Nation in April 2015, with Gitanyow   Hereditary Chiefs in June 2016, and with the Tahltan Central Government in   October 2017. The following subsections profile northwest BC focusing on the   Highway 16 and Highway 37 corridors with reference to population data from Statistics   Canada’s 2016 Census of Canada. Highway 16 Corridor From the deepwater port   at the City of Prince Rupert on the west coast, Highway 16 extends eastward   to Terrace, the Hazeltons, Smithers, and Prince George; the Canadian National   Railway also follows this route. Rural settlements and Indigenous reserves   are interspersed throughout the region. With a strong history in forestry,   mining, and rail transport, these communities have shown business growth and   development of a wide array of goods and service contractors related to   mineral exploration and mining. In 2016, Terrace was home to more than 11,000   residents and Smithers had a population of 5,350; further east, the northern   service center of Prince George has a population of more than 86,000 people.   Highway 37 Corridor Highway 37 connects with Highway 16 at Kitwanga and   extends northward to the Yukon border. At Meziadin Junction, a secondary   route (Highway 37A) branches west and connects to the deep-water port in the   community of Stewart. The Brucejack Access Road intersects Highway 37 60 km   north of Meziadin Junction at km 215 of Highway 37. Mining and forestry   industries use the Stewart World Port and the SBT to ship products from   northern BC and Yukon to international destinations, taking advantage of   Canada’s most northerly ice-free port. Further north, the communities along   this corridor include Iskut, Dease Lake, and Good Hope Lake. With the   exception of Stewart, most communities in this area are Indigenous.   Indigenous communities include the Nisga’a Nation communities of   Gitlaxt’aamiks, Gitwinksihlkw, Laxgalts’ap, and Gingolx and the Tahltan   Nation’s communities of Iskut, Telegraph Creek, and Dease Lake. These   communities rely heavily on public sector employment, with growing   involvement in the mining industry. They are distant from larger service   centers and Dease Lake and Telegraph Creek are not connected to the   provincial electricity network. Dease Lake, with a population of   approximately 400 people (on-and off-reserve) in 2016, is the main center for   goods and services (including a small airstrip), and is located approximately   an eight-hour drive to either Smithers or Whitehorse. Stewart, BC was   established in 1902, and following an influx of gold seekers beginning in   1906, had a population of approximately 10,000 by 1910. Its population has   subsequently fluctuated in response to mining (primarily) and forestry   cycles, with many of the current structures constructed for development of   the Granduc Mine in the 1960s. Since the Granduc Mine’s closure in the 1980s,   the town’s population declined dramatically from nearly 1,500 in 20-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 1981 to approximately 500   people between 2006 and 2011. This was followed by a further 19% decline to   400 residents in 2016. Possible mine developments in the Highway 37A corridor   have the potential to reverse the decline in population. As mentioned above,   announcements of mining and LNG investments in recent years have created   renewed optimism for opportunities in the shipping and LNG industries and the   potential for increased jobs and investment to the region. 20.1.2.2   Traditional Use The Brucejack Gold Mine is located on Crown land in an area   historically used by several Indigenous groups. A desk-based ethnographic   overview for the potentially affected Indigenous groups was undertaken in   2012 and 2013. In addition, a Traditional Knowledge/Traditional Use (TK/TU)   study was completed for the Tsetsaut Skii km Lax Ha. These studies identify   areas and seasons where Indigenous groups have engaged in traditional   interests and activities, including hunting, fishing, gathering, and   spiritual activities. As described further below, the location of the mine   site is covered by the Cassiar-Iskut Stikine LRMP, which was developed by the   province of BC resource agencies in consultation with Indigenous partners,   communities, and other stakeholders. When the LRMP was approved in 2000, the   Tahltan Nation became the first Indigenous group in BC to have participated   in a LRMP process. 20.1.2.3 Non-Indigenous Land Use The mine site is located   in the area covered by the Cassiar Iskut-Stikine LRMP, which was approved by   the province in 2000 and encompasses 5.2 million hectares of northwestern BC.   The LRMP is a sub-regional integrated resource plan that establishes the   framework for land use and resource management objectives and strategies, and   provides a basis for detailed management planning. The LRMP outlines the   management direction, research and inventory priorities, and economic   strategies for the Cassiar Iskut-Stikine area, and presents an implementation   and monitoring plan to reach the established objectives. The Brucejack Access   Road and transmission line east of the head of Knipple Glacier lie within the   boundaries of the South Nass Sustainable Resource Management Plan (SRMP)   area, finalized in June 2012. The SRMP is a landscape-level plan that   addresses the sustainable management of land, water, and resources while   considering economic interests. The area surrounding the Brucejack Gold Mine   has been the focus of mineral exploration for many years. There are   indications that prospectors explored the area for placer gold in the late   1800s and early 1900s. Placer gold production has been reported for   Sulphurets Creek in the 1930s, and a large log cabin near the confluence of   Mitchell and Sulphurets Creeks was reportedly used by placer miners until the   late 1960s. The region surrounding the mine is extensively staked with   mineral claims and several other mining companies have active exploration   programs nearby. The mineral deposits in and adjacent to the Brucejack Gold   Mine have been extensively explored on an intermittent basis since the 1960s.   Intensive underground exploration adjacent to Brucejack Lake in the 1980s by   Newhawk was supported by an exploration road from Bowser Lake over Knipple   Glacier. Results of the 2012 non-traditional land use baseline research   program indicate that a limited number of people access the general area   between the town of Stewart and Bell II. Those known to access the broader general   area include those with specific licenses and tenures for land and resource   use, such as trappers, guide outfitters, hunters, and those who participate   in commercial recreation activities, such as heli-skiing, guided freshwater   20-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE recreation, and guided   mountaineering. Other individuals with interests in the general area include   those who hold forestry licenses, mineral claims, and placer claims, all   linked to resource development and industry, as well as water licenses, which   may be linked to commercial recreation businesses. Overall, land use in the   area is of low intensity and activities are generally seasonal in nature.   20.1.2.4 Archaeology and Heritage Resources Archaeological assessments were   conducted in accordance with approved methodologies of permits issued under   the Heritage Conservation Act around the mine site and along the access and   transmission corridors. Two small prehistoric archaeological sites were   identified in proximity (within 1 km) to mine-related infrastructure and were   avoided during construction. Pretivm maintains a Heritage Management Plan   with a Chance Find Procedure in the event that additional archaeological   resources are encountered. 20.1.2.5 Social and Community Management Systems   Pretivm developed an ESEMP as a requirement of its EAC. The ESEMP comprises   specific strategies to minimize, mitigate, and/or manage potential adverse   effects while enhancing positive impacts of the Brucejack Gold Mine on   surrounding local and Indigenous communities. These communities comprise the   Nisga’a villages of Gitlaxt’aamiks, Gitwinksihlkw, Laxgalts’ap, and Gingolx,   and Telegraph Creek, Dease Lake, Iskut, Hazelton, New Hazelton, Stewart,   Terrace, and Smithers. Strategies relate to local employment, procurement,   training, transportation, and communications protocols, including reporting   and feedback. The ESEMP was first drafted in August 2015 and provided to the   Nisga’a Lisims Government, Tahltan Central Government, and Tsetsaut Skii km   Lax Ha First Nation for review and comments. The ESEMP is updated on an   annual basis. Pretivm prepares an annual report on the outcomes and   achievements related to the ESEMP each year and circulates it to the BC EAO,   Indigenous groups, and Local Study Area communities. This report documents   the following:  Engagement with, and   feedback from, local and regional residents    Employment, hiring, and recruitment statistics, including efforts for   local and Indigenous hiring  Summary of   education and training initiatives    Procurement initiatives, including local and Indigenous contracts  Changes or updates to the workforce   transportation strategy. 20.1.3 Consultation Pretivm recognizes the   importance of carrying out consultation and will continue to meet all   regulatory requirements to conduct consultation. Pretivm regularly engages   with Indigenous groups, community residents, local governments, and   educational institutions in northwest BC in order to provide information and   seek feedback about the Brucejack Gold Mine. Pretivm is aware of and   committed to implement new BC regulatory requirements arising from Bill 41,   the BC Declaration on the Rights of Indigenous Peoples Act that came into   effect in November 2019. 20.1.3.1 Consultation Policy Requirements Provincial   and federal regulations, various permit requirements, best practices, and   internal company policies contain provisions for consultation with Nisga’a   Nation, Tsetsaut Skii km Lax Ha, Tahltan Nation, and various communities,   both Indigenous and non-Indigenous. 20-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.1.3.2 Consultation   Community engagement and consultation are fundamental to the success of the   Brucejack Gold Mine. Since 2011, Pretivm has regularly consulted with the   Nisga’a Nation, Tahltan Nation, Tsetsaut Skii km Lax Ha, as well as other   Indigenous groups. As part of the environmental assessment process, Pretivm   participated in all BC EAO technical working group meetings, which involved   engagement with all relevant government agencies, and Indigenous   representatives. Through this process, Pretivm developed a specific   consultation plan for engagement with Indigenous groups, spanning from the   environmental assessment pre-application through to the post-application   periods. Indigenous, public, and government consultation activities, such as   private and community meetings, open houses, information distribution   activities and site tours, all informed the EAC application process and subsequent   permitting processes. In recent years, engagement has focused on permit   amendments and local hiring to fill positions at the mine (including Pretivm   and contractor workers) and opportunities for education, training,   procurement, and addressing barriers to employment. Pretivm employs a   full-time community relations manager, based at the company’s office in   Smithers. The community relations manager is responsible for engagement with   Indigenous groups and other local stakeholders, and works with Pretivm’s   staff and contractors to ensure that the company’s commitments for   engagement, communication, and local recruitment are addressed. Consultation   activities are tracked and recorded using an online database and are   regularly reviewed to promote and strengthen continual relationship building   and issues tracking. Ongoing consultation efforts aim to engage both the   leadership and community membership and attempt to resolve potential issues   and concerns as they arise, with a focus on proactive inclusion and increased   supplier development within the Brucejack supply chain for local and   Indigenous businesses. No substantive issues have been raised to date   regarding the mine. Pretivm has and continues to engage and collaborate with   the federal, provincial, regional, and municipal government agencies and   representatives as required with respect to topics such as permit compliance,   land and resource management, and environmental and social studies. Pretivm   consults with the public and relevant stakeholder groups, including land   tenure holders, businesses, economic development organizations, businesses   and contractors (e.g., suppliers and service providers), education and   training providers, and special interest groups (e.g., environmental, labour,   social, health, and recreation groups), as appropriate. 20.2 Environmental   Assessment Certifications and Permitting Mining projects in BC are subject to   regulation under federal and provincial legislation to protect workers and   the environment. This section discusses the principal licenses and permits   acquired for the Brucejack Project. 20.2.1 Environmental Assessment   Certifications Major mining projects in BC are subject to environmental   assessment and review prior to certification and issuance of permits to   authorize construction and operations. Environmental assessment is a means of   ensuring the potential for adverse environmental, social, economic, health,   and heritage effects or the potential for adverse effects on Aboriginal   interests or rights are addressed prior to project approval. Brucejack was   subject to both the BC Environmental Assessment Act (BCEAA) and Canadian   Environmental Assessment Act (CEAA) 2012 review processes. The design   production rate of 2,700 t/d exceeded the BC provincial threshold criterion   for requirement of an environmental assessment as specified in the BC   Reviewable Project Regulations (75,000 t/a (or 205 t/d)), and the federal   threshold criterion for gold mine developments of 600 t/d, as specified under   the Regulations 20-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Designating Physical   Activities. On March 26, 2015, BC EAC #M15-01 was awarded and on July 27,   2015, a federal project approval was issued in a Decision Statement under   Section 54 of the CEAA, 2012. The Brucejack EAC #M15-01 has been amended five   times. These amendments were to bring the EAC into conformance with changes   to infrastructure and design that resulted both during the initial Mines Act   and Environmental Management Act permits application and review process, and   later, due to facility refinements during subsequent detailed design and   construction. The fifth EAC amendment included increasing the total tonnage   to be mined and increased the daily/annual mining rate. The federal Decision   Statement is not subject to amendments and the increase in production rate   was not sufficient to require a new federal environmental review. Table 20-1:   List of Amendments to EAC #M-15-01 On December 21, 2017, the EAO issued a   determination that the project has been substantially started, which has the   effect that the EAC remains in effect for the life of the project, subject to   the Minister’s power to cancel and suspend a certificate under Section 37 of   the BCEAA. 20.2.2 Permits and Other Authorizations A variety of applicable BC   and Canadian environmental and safety standards and practices required   permits and other authorizations for Brucejack Gold Mine construction and   operations. legislation and/or under which authorizations have been obtained   include: Pertinent provincial and federal Environmental Assessment Act   (BC)  Environmental Management Act   (BC)  Forest Act (BC)  Forest and Range Practices Act (BC)  Forest Practices Code of British Columbia   Act (BC)  Health Act (BC)  Health, Safety and Reclamation Code for   Mines in British Columbia (BC)    Industrial Roads Act (BC)  Land   Act (BC)  Mineral Tenure Act (BC)  20-9 Amendment Date Purpose 1 10 March 2016   Added NPAG rock quarry, set time limit for PAG rock storage, removed borrow   source component, and amended layout figures and maps. 2 12 August 2016 Added   electric fencing to Wildfire Camp and revised Schedule A and figures. 3 23   November 2016 Added aviation beacons and revised layout figures and maps. 4 13   March 2017 Changed time limit for PAG rock storage in amendment #1. 5 15   November 2018 Changed maximum production to 18.5 Mt of ore, added snow melter   and process water pumping system, and changed wording related to waste rock   and tailings storage. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Mines Act (BC)  Mining Right of Way Act (BC)  Motor Vehicle Act (BC)  Nisga’a Final Agreement Act (BC)  Safety Standards Act (BC)  Transportation Act (BC)  Water Sustainability Act (BC)  Wildlife Act (BC)  Canadian Environmental Protection Act   (Canada)  Canada Transportation Act   (Canada)  Transportation of Dangerous   Goods Act (Canada)  Canada Explosives Act   (Canada)  Nuclear Safety and Control   Act (Canada)  Navigation Protection Act   (formerly Navigable Waters Protection Act) (Canada)  Fisheries Act (Canada)  International Rivers Improvement Act   (Canada).  Major federal and provincial   licenses, permits, and approvals that were obtained to construct and operate   the Brucejack Gold Mine are summarized in the following sections. This   summary cannot be considered final for the LOM due to the complexity of   government regulatory processes, which evolve over time, and the large number   of minor permits, licenses, approvals, consents, authorizations, and   potential amendments that are required from time to time. More than 100   authorizations have been issued to date for construction and operation of the   Brucejack Gold Mine and its supporting infrastructure. Additional minor   notifications, authorizations, and amendments to existing authorizations will   be required on an on-going basis to support continual improvement of the mine   plan, surface and ancillary infrastructure, as well as changes to regulatory   changes applicable to the mine’s operation. A compliance tracking system is   used. 20.2.2.1 British Columbia Authorizations, Licenses, and Permits   Issuance of statutory permit approvals occurred following receipt of the EAC   and federal EIS Decision Statement. The BC Mines Act Permit M-243 and   Environmental Management Act Permits PE 107835 and PA 107025 were issued in   July and August 2015, respectively. Mines Act Permit M-243 has been amended   seven times to accommodate mine plan changes, including the increase in   production rate to 1,387,000 t/a (3,800 t/d). The Environmental Management   Act discharge permits for waste discharges to both water and air have been   amended four times. The Brucejack Access Road, initially permitted under a BC   Mines Act exploration permit, was re-permitted as Special Use Permit S25923   under the Provincial Forest Use Regulation (Forest Practices Code of British   Columbia Act), which has been amended once. A full summary of active   provincial authorizations for the Brucejack Gold Mine is presented in Table   20-2. 20-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 20-2: List of BC Major   Authorizations, Licenses, and Permits Obtained to Develop and Operate the   Brucejack Project table continues... 20-11 BC Government Agency – Permits and   Licenses Enabling Legislation and Authorization Environmental Assessment   Office Environmental Assessment Act EAC #M15-01 issued 26 March 2015; amended   10 March 2016, 12 August 2016, 23 November 2016, 31 March 2017, and 15   November 2018. Ministry of Energy, Mines and Petroleum Resources, Approving   Mine Plan and Reclamation Program, including the northern one-third of the   transmission line on Pretivm mineral tenures. Mines Act Permit M-243 issued   22 July 2015; amended 26 August 2015, 9 September 2015, 17 March 2016, 4   August 2016, 3 April 2017, and 14 December 2018. Ministry of Energy, Mines   and Petroleum Resources Issuance of Mining Leases Mineral Tenure Act Tenures   1038597, 1038598, 1038599, and 1038600 issued 17 September 2015. Ministry of   Environment and Climate Change Strategy Discharge Mine Related Contaminants   and Effluent to Water Permit Environmental Management Act Permit 107835   issued 31 August 2015; amended 4 February 2016, 12 July 2016, 31 March 2017,   and 14 December 2018. Ministry of Environment and Climate Change Strategy   Discharge Mine Related Contaminants to Air and Ash to Ground Permit   Environmental Management Act Permit 107025 issued 9 January 2014; amended 22   July 2015, 12 July 2016, 8 September 2017 (temporary item that was included   in next amendment), and 27 March 2018. Ministry of Forests, Lands, Natural   Resource Operations and Rural Development Access Road Forest Practices Code   of British Columbia Act (Provincial Forest Use Regulation) and Mining Right   of Way Act Special Use Permit S25923 issued 23 July 2015; amended 7 June   2016. Ministry of Forests, Lands, Natural Resource Operations and Rural   Development Occupant License to Cut Forest Act Licenses to cut to clear   timber along the transmission line and access road route and other   infrastructure sites; OLTC L48433 and L50280 issued 1 May 2015 and 23 July   2015, respectively. Ministry of Forests, Lands, Natural Resource Operations and   Rural Development Water License – Use Water Sustainability Act Process Water   Withdrawal License 500684 issued 26 November 2018 (replaces prior license).   Ministry of Forests, Lands, Natural Resource Operations and Rural Development   Water Licenses – Diversion and Use Water Sustainability Act Diversion of   surface waters around site and withdrawal from mine. Licenses C132076 and   C132077. Technical Safety BC Design Registration Safety Standards Act   Incinerators Ministry of Forests, Lands, Natural Resource Operations and   Rural Development Licenses of Occupation (a total of 20 sites) Transmission   Line (southern two-thirds), Wildfire Camp / Laydown, Bowser Aerodrome / Camp   / Laydown, Explosives Storage Areas, Knipple Transfer Station, Scott Weather   Station, Communication Tower Sites, Aviation Beacon Sites Land Act Most   issued in 2015 with additions in 2016. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.2.2.2 Federal Approvals   and Authorizations Applications for federal approvals can be completed   concurrently with or following the provincial environmental assessment   process, but permits and authorizations cannot be obtained until federal   approval of the Table 20-3 lists federal approvals obtained for the Brucejack   Gold Mine. EIS. Table 20-3: List of Federal Approvals and Licenses Obtained   to Develop and Operate the Brucejack Project 20-12 Federal Government   Approvals and Licenses Enabling Legislation and Authorization Canadian   Environmental Assessment Agency (as of 2019 replaced by Impact Assessment   Agency of Canada) EIS CEAA 2012 (replaced in August 2019 by Impact Assessment   Act) Decision Statement issued 27 July 2015. Environment and Climate Change   Canada Alteration of Flow on an International River International Rivers   Improvement Act Exception received 26 November 2015. Environment and Climate   Change Canada MDMER Fisheries Act/Metal and Diamond Mining Effluent   Regulation (MDMER) The mine became subject to MDMER on 12 January 2016.   Transport Canada, Navigable Waters Protection Program Stream Crossing   Authorizations Navigation Protection Act (in 2019 replaced by Canadian   Navigable Waters Act) Group 4 “Navigable Waters Protection Program” Issued 10   December 2012; not subject to the act as of 6 July 2016. Natural Resources   Canada Explosives Storage Facilities Explosives Act Innovation, Science and   Economic Development Canada Radio Licenses Radio Communication Act Canadian   Nuclear Safety Commission Radioisotope License (Nuclear Density Gauges)   Nuclear Safety and Control Act BC Government Agency – Permits and Licenses   Enabling Legislation and Authorization Ministry of Environment and Climate   Change Strategy Hazardous Waste Generator Registration Hazardous Waste   Regulation Provincial Identification Number BCG 10829 issued 6 September   2013. Northern Health Camp Operation Permits (potable water system (including   wells), sewage systems, camp operations, camp food services) Drinking Water   Protection Act/Health Act/Municipal Wastewater Act All issued by Northern   Health starting in 2013, ongoing as annual updates for changes in design and   operations. 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.2.3 Financial Assurance   The current reclamation security for activities within the area covered by   Mines Act Permit M-243 (primarily the area within the Mining Leases) totals   $31,700,000, which is based on a full build-out of the mine. This reclamation   security is reviewed annually as part of the annual MEMPR reporting   requirements and is also subject to major review at least every five years to   reflect changes in mine plans and anticipated reclamation costing rate   changes. The next five-year review is due in July 2020. The Brucejack Access   Road reclamation security held under the Special Use Permit totals $2,000,000.   This security is subject to annual changes based upon Canadian Consumer Price   Indices. A number of smaller reclamation securities are established under   each license agreement for facilities built on Licenses of Occupation that   have an aggregate value of $70,000. 20.3 Environment 20.3.1 Environmental   Setting 20.3.1.1 Introduction The Brucejack Gold Mine is located in an alpine   area along the southwest shore of Brucejack Lake at the western terminus of   the Brucejack Access Road (Figure 4-2). The mine site elevation is   approximately 1,400 masl and the treeline is at approximately 1,200 masl.   Elevations of the Knipple Camp (km 56), Bowser Aerodrome (km 51), and   Wildfire Camp and Security (km 1) areas are approximately 470, 444, and 453   masl, respectively. The 73 km Brucejack Access Road climbs to an elevation of   approximately 1,000 masl at the summit of Scott Pass, near km 17 between   Wildfire Camp and Bowser Aerodrome. This topographic and spatial variation   results in significant temperature, precipitation, and wind differences   between these project infrastructure areas and along the Brucejack Access   Road. The mine and its supporting infrastructure lie in a transition zone   between the very wet coastal and drier interior regions of BC. This part of   northwestern BC is dominated by weather systems generated from the Pacific   Ocean, but is also strongly influenced by orographic effects caused by the   local mountain topography that produces high spatial variability in snowfall   and precipitation, and in temperatures and snowmelt. In addition, the large   glacial areas around the mine site can impact snowmelt rates and produce high   runoff volumes during the summer months. The humid climate and physical   characteristics of the region result in dynamic streams and rivers with high   annual runoff rates and high average stream flows. The Brucejack Gold Mine   and its supporting infrastructure are located in a rugged area with   elevations ranging from approximately 500 masl at the lower elevations along   parts of the Brucejack Access Road and the transmission line to 1,400 m at   the mine site. Peaks surrounding the mine site and for the northernmost part   of the transmission line reach elevations of up to approximately 2,200 masl.   Glaciers and icefields surround the mine site to the west, south, and east.   Recent and rapid deglaciation has resulted in over-steepened and unstable   slopes in many areas. Recently deglaciated areas typically have limited soil   development, consisting of glacial till and colluvium. Lower elevation areas   with mature vegetation may have a well-developed organic soil layer.   Avalanche chutes are common throughout the area, and management of avalanche   hazards is a key aspect of mine and access road operations. Avalanche and   glacier access hazards are actively monitored and managed by mountain safety   personnel within the mine’s health and safety department, in accordance with   the Avalanche Safety Plan (ASP). 20-13 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The mine site area (all mine   infrastructure west of the upper Knipple Glacier, km 71) is situated within   the Brucejack Creek watershed, which is a small headwater sub-basin within   the Sulphurets Creek watershed (drainage area 299 km2). Sulphurets Creek is a   tributary of the Unuk River that flows southwest, eventually discharging to   the Pacific Ocean northeast of Ketchikan, Alaska (drainage area 2,577 km2 at   the mouth). The first 71.5 km of the Brucejack Access Road and the   infrastructure areas along the road are located within the Bell-Irving River   watershed, which drains to the Nass River. The Nass River discharges into the   Pacific Ocean in Canada. There are no fish present within Brucejack Lake or   Creek, or in most of Sulphurets Creek downstream of the mine. The nearest   recorded fish presence is more than 20 km downstream of the mine,   approximately 300 m upstream of the confluence of Suphurets Creek with the   Unuk River. The Bowser and Bell-Irving rivers are both fish-bearing,   including anadromous salmonids and resident Dolly Varden char. Wildlife   species present in the area include black and grizzly bears, moose, and   mountain goats. Pretivm undertook extensive environmental baseline studies in   support of its application for an EAC and EIS Decision Statement as well as   for subsequent major provincial permit applications (Mines Act Permit,   Environmental Management Act permits, and other authorizations). These   included atmosphere/climate, surface and subsurface hydrology, aquatics,   geochemistry, hydrogeology, surface water and sediment quality, limnology,   fish habitat, soils, vegetation, and wildlife studies to characterize the   local and regional ecosystem prior to major disturbances. Archaeology,   heritage, land use, cultural, TK, and socioeconomic baseline studies were   also carried out to characterize the regional human environment. An extensive   environmental monitoring program was implemented through mine construction   and is being continued through mine operations in accordance with the mine’s   authorizations. 20.3.1.2 Climate The climate of the region is relatively   extreme and daily weather patterns are unpredictable. Prolonged clear sunny   days can prevail during the summers. Precipitation in the region is   approximately 1,600 to 2,100 mm annually. The majority of precipitation falls   during the autumn and winter months, from October to April. Records show that   Brucejack Lake receives approximately 70% of its annual precipitation on   average during this period. The months of October through to January   typically have the highest monthly precipitation amounts, while late spring   or early summer months are typically much drier. Snowpack typically ranges from   1 to 2 m deep, but high winds can create snowdrifts up to 15 m deep.   Permanent icefields are present in the upper reaches of the Brucejack Lake   watershed. A full meteorological station was established west of the   Brucejack Camp in mid-October 2009 to collect site-specific weather data. The   station measures wind speed and direction, air temperature and pressure,   rainfall, snowfall, relative humidity, solar radiation, net radiation, and   snow depth. The Brucejack Lake station operated from October 2009 to August   2014. The tower and instrumentation were relocated to a site in the Valley of   the Kings valley, closer to and approximately 0.6 km from the Brucejack Camp,   in September 2014. Additional meteorological stations have been installed at   the Bowser aerodrome, 18.2 km from Brucejack Camp, and Scott Pass at km 18   along the Brucejack Access Road, approximately 30 km from Brucejack Camp.   Table 20-4 presents the estimated average monthly climate data for the   Brucejack Project site (BGC 2017). Average monthly temperature data for the   mine site area are based on temperature data collected at site for the   2013-2016 period. Annual evaporation and sublimation at the site was   estimated using local climate data from the on-site climate station for the   period 2010 to 2012, and Reference Evapotranspiration (REF-ET) calculation   software (Version 3.1.14). Climate inputs required for the model include air   temperature, wind speed, incoming solar radiation (or sunshine hours),   relative humidity, dew point temperature, and atmospheric pressure. 20-14 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 20-4: Average Monthly   Climate Data for the Brucejack Gold Mine Site Source: BGC (2017) 20.3.1.3   Ecosystems The mine site is situated in a gossanous area above the treeline.   Prior to construction, it was dominated by unvegetated and sparsely vegetated   terrain, with limited areas of alpine ecosystems within the gossan itself.   Alpine ecosystems, including tundra, heather, and fellfield classes, are   common in the area surrounding the mine site. The Brucejack Access Road   traverses valley bottom forests, subalpine stands of subalpine fir, and   Engelmann spruce in higher elevation sections, particularly through Scott   Pass. Dry glaciofluvial terraces supporting early seral pioneer ecosystems   are present within the lower elevation portions of the Bowser River valley.   The transmission line from the mine site to its intertie at the Long Lake   Hydro substation traverses both mature forest and recently deglaciated   terrain, dominated by scoured rock, eroding moraine, and glaciofluvial   deposits. The northernmost segment extending from Knipple Camp to the mine   site traverses mountain ridges and tops and includes several large glacier   spans. There are several wetlands along or near to the Brucejack Access Road   in the Scott Pass area between km 15 and 30, and along the Bowser River   floodplain section of the road. Wetlands are limited in extent in the vicinity   of the mine site. Wetlands are valued ecosystem components and were assessed   as part of the Brucejack Gold Mine environmental assessment process. Baseline   studies were conducted to map and classify wetlands and to identify the   primary wetland functions. These baseline data were used to identify areas   where toad tunnels were installed along the Brucejack Access Road to provide   safe access to wetlands for migrating Western toads, a protected species   under the federal Species at Risk Act. The region surrounding the Brucejack   Gold Mine and its supporting infrastructure is home to many terrestrial and   aquatic wildlife species, including black and grizzly bears, mountain goats,   moose, bats, furbearers, small mammals, birds of prey, migratory songbirds,   waterfowl, and herptiles. These include several species at risk, as well as   species of cultural and economic importance. Prior to the environmental   assessment process, Pretivm 20-15 Month Average Temperature (°C) Average   Precipitation (mm) Average Evaporation/ Sublimation (mm) January -5.0 269 2   February -6.9 231 2 March -5.8 196 2 April -2.6 105 4 May 3.8 95 10 June 5.8   72 23 July 8.1 90 46 August 8.5 150 41 September 4.5 224 25 October -0.1 267   8 November -5.2 233 2 December -7.7 267 2 Average/Total -0.2 2,200 167 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE evaluated the potential for   adverse effects on representative species that were identified as being at   risk or of concern within the area through baseline surveys. Species at risk   that were encountered during baseline studies included wolverine, fisher,   grizzly bear, western toad, barn swallow, rusty blackbird, olive sided fly   catcher, and little brown Myotis. While no little brown Myotis bat habitat   was identified as disturbed, bat houses were installed along the Brucejack   Access Road and along the transmission line. Species of concern include those   that may not be of conservation concern but are of regional importance for   other reasons, or are identified in the Cassiar Iskut-Stikine LRMP, and   include moose, mountain goat, black bear, and American marten. Wildlife   monitoring is conducted, and additional mountain goat and moose surveys will   be conducted for these species at five-year intervals throughout mine life.   Wildlife observations at mine infrastructure areas are recorded and   helicopter pilots are required to implement measures to minimize or prevent   disturbance of mountain goats and other species. The mine implements a   rigorous waste management program and other measures, including seasonal   electrified fencing around Knipple and Wildfire camp located within areas of   high bear activity, to prevent wildlife access to food or other potential   mine-related attractants. A Wildlife Advisory Committee (WAC), which includes   representatives of the Nisga’a Nation, Tahltan Central Government,   Tsetsaut/Skii km Lax Ha, and BC MFLNRORD, was established at the beginning of   mine construction and continues to meet during mine operations on an annual   basis. The Brucejack Gold Mine is situated in the headwaters of the Brucejack   Lake watershed; Brucejack Creek drains Brucejack Lake and enters the   subglacial flow of Sulphurets Creek approximately 3.1 km downstream of the   Brucejack Lake outlet. Sulphurets Creek flows approximately 20 km downstream   of the Brucejack / Sulphurets Creek confluence to its confluence with the   Unuk River. Fish are absent within and downstream of Brucejack Lake in all   waterbodies, including Sulphurets Creek, upstream of a barrier located 300 m   upstream of the confluence of Sulphurets Creek and the Unuk River. The Unuk   River is a large river system that provides important habitat for the five   species of Pacific salmon, as well as habitat for resident trout (cutthroat,   rainbow), and resident Dolly Varden. The Brucejack Access Road traverses the   watershed of the Bell-Irving River, including its tributaries Wildfire Creek,   Todedada Creek (tributary to Treaty Creek, which is tributary to the   Bell-Irving River), and the Bowser River. The Bell-Irving River, in turn,   drains to the Nass River. The Bell-Irving River system provides habitat for   sockeye, Coho, and Chinook salmon; resident and anadromous trout (rainbow and   steelhead); resident char (Dolly Varden and bull trout); mountain whitefish;   and coarse fish species. The fisheries resources and fish habitat of   potentially affected rivers and their tributaries were assessed as part of   the baseline program for the Brucejack Gold Mine. 20.3.2 Geochemistry   20.3.2.1 Introduction The geochemistry of rock that has been or will be   disturbed, excavated, or exposed at the Brucejack Gold Mine has been   characterized through static and kinetic test programs. The characterization   programs have also evaluated the water quality impacts of explosives used for   blasting and cement products used in shotcrete and paste backfill. Static   tests include acid base accounting (ABA) analyses to evaluate whether   material is PAG, elemental analyses to identify parameters that are elevated   and of potential concern, and shake flask extraction tests to provide an   indication of soluble loads and drainage chemistry. Kinetic tests including   field bins (n=14), humidity cells (n=81) and saturated columns (n=34) have   been carried out to assess the long-term behaviour of materials under   site-specific conditions. Baseline studies and confirmatory sampling programs   have been carried out for the following: Waste rock  Ore, tailings, and paste backfill  20-16 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Quarry rock  Underground mine water  Water treatment plant effluent and   associated treatment residues (i.e., sludge)    Excavated surface rock exposures and runoff contacting these   exposures  Explosives-related   residues.  The results of these   characterization studies have informed management and monitoring plans   designed to prevent or minimize potential geochemistry and chemistry related   adverse environmental effects associated with development, operation, and   closure/reclamation of the Brucejack Gold Mine. The following sections   summarize the geochemical characteristics of the above referenced rock, mine   wastes, and contact waters, and describe the associated management strategies.   20.3.2.2 Waste Rock Waste rock generated at the Brucejack Gold Mine is   predominantly PAG and is managed following best practices to minimize the   oxidation of sulphide minerals (i.e., pyrite). All waste rock is managed as   PAG and has and will continue to be either deposited subaqueously in   Brucejack Lake or placed as backfill in the underground mine below the   post-closure final water table elevation. Surface waste rock excavated to   support development of the mine site during construction was placed subaqueously   in Brucejack Lake. Excavation of underground mine waste rock is ongoing, with   this waste rock placed both in Brucejack Lake and in the underground mine as   backfill. There are no permanent surface subaerial waste rock dumps at the   mine site; however, the Mines Act Permit (M-243) authorizes temporary   subaerial storage of waste rock for up to two years prior to subaqueous   deposition in Brucejack Lake. Geochemical studies have been carried out to   assess the behaviour of waste rock in both saturated and unsaturated   conditions. Static characterization studies (ABA and total elemental   analyses) carried out on a total of 160 surface waste rock samples from five   different lithologic units (Fragmental Andesite (ANDX), VSF, Porphyry 2 (P2),   Conglomerate, and Porphyry 1 (P1)) indicated that 78 samples (49%) were   characterized as PAG (Pretivm 2017; Pretivm 2018a). Surface waste rock   characterization studies identified enrichments (greater than 10x average   continental crust) in silver, arsenic, manganese, antimony, and selenium   (Pretivm 2016; Pretivm 2017). Kinetic tests (field bins and saturated   columns) were initiated on the four rock units comprising 95% of surface   waste rock excavated, and results confirm that permanent subaqueous waste   rock storage will minimize potential metal leaching. The test data also   indicate that subaerial exposure of waste rock for two years prior to   permanent subaqueous storage will not result in any significant changes to   Brucejack Lake water quality (Lorax 2016a; Lorax 2017). Underground waste   rock samples (n=568) from six lithologic units (VSF, Fragmental,   Conglomerate, P1, P2, and Silicified Cap) have been characterized through   static and kinetic test work. The results indicate that rocks from all units   are dominantly PAG (n=472; 83.1%) with elevated concentrations of metals   (e.g., silver, cadmium, zinc) and metalloids (arsenic, antimony) compared to   continental crust. The data also show that many of the PAG samples contain   significant amounts of carbonate minerals (mostly calcite) that will   neutralize acidity generated and prolong the onset to acid generation   (Pretivm 2016). Under oxidizing unsaturated conditions, waste rock and   associated wall rock exposures have the potential to leach metals into mine   water. During mine operations, the underground mine and surface contact water   has and will continue to be treated by the WTP, which has been designed to   treat and manage metals of potential concern. The mine will be flooded at   closure, at which point saturated conditions are expected to limit acid   generating reactions (as supported by saturated column test results), thereby   minimizing potential adverse effects on water quality of the aquatic   receiving environment. Similarly, saturated column tests simulating   underground mine waste rock leaching behaviour in Brucejack Lake, as well as   onsite water quality 20-17 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE monitoring data, indicate   that permanent subaqueous storage of waste rock deposited in Brucejack Lake   will not result in exceedances of regulated discharge concentrations at the   outlet of Brucejack Lake. 20.3.2.3 Ore, Tailings, and Paste Backfill The   Brucejack Gold Mine mill began operating in July 2017; tailings generated by   milling have and will continue to be placed as thickened tailings in   Brucejack Lake and as cemented paste backfill in mined out stopes. The   Brucejack Gold Mine ore is characterized as PAG with elevated concentrations   of silver, arsenic, cadmium, manganese, and selenium, compared to continental   crust (BGC 2014). Characterization studies carried out on thickened tailings   generated from the mill (n=38) show the same metal enrichments, but samples   are predominantly NPAG, with a median NPR of 3.1 (Pretivm 2018a; Pretivm   2019). Paste samples (n=23) are similar in composition to thickened tailings,   but with a slightly higher median NPR (4.8). Kinetic tests have been carried   out to assess the behaviour of tailings deposited in Brucejack Lake, as well   as the behaviour of cemented paste in unsaturated and saturated conditions within   the underground mine. Saturated column tests comprised of tailings flushed   with lake water were carried out under both oxidizing and reducing conditions   to estimate potential leaching rates and changes to Brucejack Lake water   quality following deposition. The results of the study (Lorax 2016b)   indicated that chemical loads released into the lake from tailings would not   result in significant changes to Brucejack Lake water quality. Kinetic test   work to assess chemical loads released from paste backfill during mine   operations indicates that chemical loads from paste backfill are minor   compared to other mine-related sources. Some potential concerns with chromium   were raised based on early-stage test work, with an off-shore sourced binder;   however, follow-up kinetic test work, using binder sourced for use at the   mine, and updated water quality modeling (Lorax 2018) do not predict any   exceedances of chromium water quality guidelines in the aquatic receiving   environment. No exceedances of chromium have been reported since paste   backfilling commenced (Pretivm 2019). Saturated column tests carried out on   paste backfill are used to predict underground mine water quality for the   post-closure flooded mine condition. The results of these tests (Pretivm   2019) do not identify backfilled tailings as the dominant source of any   parameters of potential concern. 20.3.2.4 Quarry Rock Rock excavated from the   Brucejack Gold Mine NPAG Quarry located at km 72 of the Brucejack Access Road   was used to construct the mill and Phase 2 camp pads, and for various   building foundations, roads and other construction activities at the mine   site. It continues to be used for road surfacing and other maintenance   requirements. The NPAG Quarry is located near the southeast end of Brucejack   Lake; quarry runoff flows into Brucejack Lake. The NPAG Quarry is comprised   predominantly of volcanic (plagioclase-hornblende) porphyry, with lesser   amounts of conglomerate, and has negligible sulfide mineralization.   Characterization studies of 72 NPAG Quarry rock samples have confirmed that   rock excavated from the NPAG Quarry is consistently NPAG, with low neutral   metal leaching potential. 20-18 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.2.5 Mine Water   Underground mine water at the Brucejack Gold Mine is dominantly comprised of   groundwater with added geochemical loads from blasted rock, wall rock, waste   rock backfill, and paste backfill. Underground mine water chemistry is   monitored twice a month, and results indicate that the water quality has been   within the range predicted by the water quality model. Despite the prevalence   of PAG waste rock, mine water has alkaline pH levels, supporting the   assertion that neutralization afforded by carbonate minerals will buffer any   acid generated from sulphide oxidation reactions for several decades or more   (Pretivm 2015). Similarly, there is no indication of increasing   concentrations of dissolved metals associated with the onset of ML/ARD as   predicted by kinetic tests (e.g., cadmium, cobalt, copper, iron, zinc) since   gold production commenced in June 2017. Mine water will be treated throughout   mine operations and into the closure phase. 20.3.2.6 Water Treatment Plant   Effluent and Sludge The WTP receives and treats underground mine water from   mine dewatering, surface contact water from with the surface contact water   collection system, WTP effluent collected in the CWP, and recycled process   water from the mill. The WTP is designed to chemically precipitate targeted   dissolved metals and remove resultant chemical precipitates and influent TSS.   The WTP effluent has consistently met design specifications. The water   treatment design, metals and solids removal process, and effluent design   criteria are described in the 2015 Mines Act-Environmental Management Act   Permits Application (Pretivm 2015). The WTP generates a solid waste product   (sludge) that requires management and disposal. Sludge generated from the WTP   is currently being co-deposited with thickened tailings into Brucejack Lake.   Static test results indicate that the sludge is NPAG with elevated   concentrations (greater than 10x average continental crust) of several metals   (e.g., silver, arsenic, cadmium, manganese, molybdenum, antimony, and   selenium). However, the results also show that the sludge is stable under a   range of pH and redox conditions. Kinetic tests have been carried out to   evaluate potential chemical loads that may leach into Brucejack Lake under   both oxidizing and reducing conditions. The studies predict low metal   leaching rates for the co-deposited tailings and sludge and thus no long-term   effects to Brucejack Lake water quality are anticipated. 20.3.2.7 Surface   Rock Exposures and Runoff The contact water collection system collects   contact water from within the main Mine Site areas of excavated bedrock   exposures, particularly the mill, Phase 2 Camp, and Valley of the Kings   portal pads. The contact water collection system directs water to the WTP via   the CWP. Non-contact surface runoff from areas immediately surrounding the   mine site are directed to Brucejack Lake via the East (Johnson Creek)   Diversion Channel, and to Camp Creek via the West (Camp Creek) Diversion   Channel. Camp Creek runoff is naturally acidic, with elevated metal   concentrations (e.g., silver, cadmium, copper, and zinc). Mine Site contact   water system runoff has been assessed based on direct CWP samples (n=7),   drainage into the CWP (n=4) and shake flask experiments carried out on all   surface exposed rock units (n=92). Results of ongoing monitoring are   presented in the Annual Reclamation reports. During the operations phase, all   surface runoff within the contact water collection system has and will   continue to be treated by the WTP. At closure, the mine site will be   reclaimed and surface runoff will follow natural pathways to the receiving   environment. The potential effects of this drainage on the receiving   environment will continue to be assessed as monitoring data are collected.   Based on the SFE data and water quality predictions, no significant impacts   to water quality in the receiving environment are anticipated. 20-19 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.2.8 Explosives-related   Residues Water quality model predictions presented in the Mines   Act/Environmental Management Act Permits Application (Pretivm 2015)   identified nitrite as a parameter of potential concern. The main source of   nitrite in Brucejack Gold Mine related discharge is from explosives used to   blast waste rock and ore. Explosives-related residues contain water soluble   nitrogen compounds that can affect water quality in the receiving   environment. Site monitoring data have been used to derive and refine water   quality predictions with respect to these compounds (Lorax 2018). Pretivm   implements a Nitrogen Management Plan that was developed for the Brucejack   Gold Mine and includes monitoring requirements, source control measures and   management triggers for mitigation. The water quality model was updated based   on the latest data sets and no exceedances of the current discharge limits   for nitrogen compounds are predicted, nor have any been observed since gold   production commenced (Pretivm 2018a and 2019). 20.3.3 Hydrogeology 20.3.3.1   Overview The groundwater flow system at the Brucejack Gold Mine has been   conceptualized to provide estimates of groundwater inflow to the existing and   future underground mine workings during operations and closure, and of   groundwater flow paths at post-closure. Numerical groundwater modeling of the   mine was undertaken in 2013, 2014, and 2015 to support applications for an   Environmental Assessment Certificate and Mines Act / Environmental Management   Act permits (BGC 2014; 2015). These modeling studies drew upon site   investigations characterizing hydrogeological conditions initiated in 2010.   These investigations included drilling, hydraulic testing, and monitoring   well and vibrating wire piezometer installations. Data available through late   2014 were used in conceptual and numerical groundwater model development,   calibration, and benchmarking. Routine groundwater quantity monitoring has   been ongoing at the Brucejack Gold Mine site since 2011. Hydrogeological   field programs comprised of drilling, hydraulic testing, and monitoring well   installation were undertaken in 2016 and 2018 (BGC 2017; 2019). The 2018   field investigation established 14 new monitoring wells, fulfilling   Environmental Management Act Permit PE-107835 and Mines Act Permit M-243   requirements. BGC designed and supervised all hydrogeological drilling   programs while Pretivm staff have performed ongoing routine monitoring of   groundwater levels, groundwater quality, and underground dewatering rates.   Site monitoring data indicates that continuous dewatering of the mine since   the fall of 2012 has resulted in significant depression of water levels and   development of strong, downward, vertical hydraulic gradients at most nested   well locations. The 2015 groundwater model has reasonably simulated these   impacts but slightly overpredicts underground dewatering rates. The numerical   groundwater model is currently being updated in support of the 5-Year Mine   Plan and Reclamation Program Update pursuant to permit requirements. The   model update aims to refine underground dewatering rates in light of the   expanded hydrogeological data set and the increased production rate.   Groundwater system conceptualization for the 2020 Update is reasonably   consistent with the 2015 model. Preliminary results indicate dewatering rates   that are within ranges previously provided by the 2015 model (BGC 2015).   20-20 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.3.2 Conceptual   Hydrogeologic Model Surface topography has a pervasive influence on the   groundwater flow system at the Brucejack Gold Mine. The elevation within the   immediate mine area ranges in elevation from approximately 1,350 masl at the   outlet of Brucejack Lake to over 2,000 masl at the highest peaks. Measured   groundwater elevations suggest that the water table is a subdued replica of   topography, with depths to groundwater typically greater in the uplands   relative to the valley bottoms. Groundwater enters the flow system from   infiltrating precipitation and snowmelt, with lesser components supplied by   surface water infiltration in lakes. Groundwater discharge zones are   generally restricted to lakes, creeks, gullies, and breaks in slope. The hydrostratigraphy   of the mine site is comprised of a thin, discontinuous layer of glacial till   or colluvium underlain by bedrock. Thicker unconsolidated deposits are   confined to local sections of the valley bottom and are not present near the   mine. The bedrock at the mine site can be broadly divided as follows:   Triassic marine sedimentary and volcanic rocks of the Stuhini Group  Jurassic sediments and volcanics of the   Hazelton Group  Early Jurassic dikes,   sills, and plugs of diorite, monzonite, syenite, and granite, the most common   of which are grouped as the “Sulphurets Intrusions”.  There is a general site-wide trend of   decreasing bedrock hydraulic conductivity, K, with depth, although K may vary   by a few orders of magnitude at any given depth. Based on available data,   fault structures are not universally conductive across the mine site.   20.3.3.3 Numerical Hydrogeologic Model The conceptual model described in   Section 20.3.3.2 was used as the basis for the development of a numerical   hydrogeologic model. The numerical model was initially developed in 2013 (BGC   2013), and was subsequently refined in 2014 (BGC 2014) and again in 2015 (BGC   2015) for the Mines Act / Environmental Management Act permits application   (Pretivm 2015). The model was built using the graphical user interface   Groundwater Vistas (Environmental Simulations Inc. 2011) and MODFLOW-Surfact   code (Harbaugh et al. 2000; HydroGeoLogic 2012). The numerical model was   calibrated in stages to available hydrogeologic data collected within the   study area, including steady-state and transient hydraulic head targets,   vertical hydraulic head gradients, streamflow data, and winter low-flow   estimates for the period 2008 to 2014, and volumetric discharge data   available from mine dewatering activities for the period 2011 to late-2014.   The results of model calibration to pre-disturbance and post-disturbance   conditions, and benchmarking to transient adit dewatering data indicated that   the numerical representation of the hydrogeological system was suitable for   predictive analyses. The 2015 groundwater model is currently being updated to   support water balance and water quality model updates for the 5-Year Mine   Plan and Reclamation Program Update pursuant to permit requirements (due July   2020). The 2020 groundwater model update will build on the assumptions   underpinning the 2015 groundwater model, incorporating a longer water level   and underground dewatering record. The 2020 groundwater model is being   constructed in FEFLOW 7.2, a part of the MIKE software suite (DHI 2020). FEFLOW   is a widely accepted program for groundwater flow models in the mining   industry. FEFLOW is three-dimensional finite-element package capable of   simulating groundwater flows in complex hydrogeological settings. FEFLOW was   selected over the MODFLOW-Surfact code for the 2020 model update on account   of its flexible mesh design, which facilitates presentation of faults and   complex underground geometries. The 2020 model will provide increased   horizontal and vertical discretization in the mine area. 20-21 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.3.4 Predictive   Simulations and Inflow Estimates Predictive simulations from the 2015   groundwater model were based on the 18-year underground mine plan with a   throughput of 2700 t/d as presented in the 2014 FS (Ireland et al. 2014).   Model boundary conditions representing the development (i.e., underground   workings, access and egress ramps, and declines) were activated according to   the annual schedule in the mine plan, and remained active throughout mining   operations, while mining stopes were deactivated after a period of one year,   at which point the stopes were assumed to be backfilled with paste. The 2020   groundwater model update will consider a 14-year underground mine plan with   an annual average production rate of 3800 t/d. The 2015 groundwater model   provided a range of groundwater inflows based on three model scenarios: a   base case, a low K case, and a high K case. The base case reflected the best   calibrated parameters set and represented the ‘best estimate’. The low K and   high K cases represent lower and upper ranges of key parameters sets   controlling flow rates; however, these scenarios did not present optimal   calibration statistics. Results from these three cases are presented in   Figure 20-1 for the 18-year mine plan. The 2015 base case average annual rate   of groundwater inflow to the underground workings was predicted to remain   relatively stable throughout the development of the Valley of the Kings   resource, ranging between 2,500 and 2,900 m3/d. With initiation of mining in   the West Zone, predicted annual average inflows increased from 2,900 to 3,500   m3/d, stabilizing at 3,500 m3/d for the remainder of mine life. The overall   average inflow for the simulated mining period was 2,900 m3/d. Groundwater   inflow to the underground workings for the base case was predicted to vary   seasonally by about 2,000 m3/d; estimated inflows varied from approximately   1,400 to 3,400 m3/d (58 to 141 m3/h) over the first half of mine life and   from approximately 2,400 to 4,400 m3/d (100 to 183 m3/h) later in mine life.   Observed monthly underground dewatering rates from 2016 to 2019 are shown in   Figure 20-1. The average annual dewatering rate for this period is 1,280 m3/d   (53 m3/hr) with annual minima and maxima ranging from 550 m3/d (23 m3/hr) to   2100 m3/d (88 m3/hr), respectively. The observed data track between the low K   case and base case model runs with annual minima overpredicted by the low K   case. 20-22 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 20-1: Observed and   Simulated Inflow to Underground Workings for Selected Model Scenarios 20.3.4   Water Management 20.3.4.1 General Water management is a critical component at   the Brucejack Gold Mine, for its operation and associated environmental   protection in this high precipitation and runoff environment. As such,   through its consultants and in accordance with its regulatory requirements,   Pretivm developed a Water Management Plan that applies throughout the LOM.   The Water Management Plan was prepared prior to mine construction as part of   the EMP; was updated as appropriate during construction; and following completion   of the contact water management system (infrastructure), was expanded to an   OMS Manual (Surface Water Management Facilities OMS Manual) that includes   both the Water Management Plan component and other details such as specifics   of procedures, roles, and responsibilities. The goals of the Water Management   Plan are to: Provide necessary guidance for the management of surface water   within the core infrastructure area of the mine site, where significant PAG   bedrock excavation was necessary as part of site preparation and where   construction also resulted in significant changes to local flow pathways and   drainage areas  20-23 Monthly   Underground Inflow (m3/d) 14000 12000 10000 8000 6000 4000 2000 0 Jan-16   Dec-16 Dec-17 Dec-18 Jan-20 Dec-20 Dec-21 Dec-22 Jan-24 Dec-24 Dec-25 Dec-26   Jan-28 Dec-28 Dec-29 Dec-30 Observed UG Flows 2015 Base Case (2700 t/d) 2015   Low K Case (2700 t/d) 2015 High K Case (2700 t/d) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Provide guidance in terms of processes,   maintenance activities, inspections and all necessary methods to ensure that   all surface water discharges from the mine are in compliance with regulatory   water quality requirements (i.e., to protect the water quality of the aquatic   receiving environment downstream of the mine)    Provide and retain water for mine operations  Divert non-contact water around the mine   site  Define water management control   structures.  Strategies for water   management that were applied as part of mine design and construction which   remain in effect through operations include: Separation of non-contact water   (from the area surrounding the mine site) from contact water via non-contact   diversion channels (Camp Creek and Johnson Creek diversion channels), and   directing the undisturbed runoff away from mining related activities  Minimizing the size of the mine site   development area and minimizing surface PAG rock excavation by adjusting the   elevations of the mill and Phase 2 Camp pads    Collecting water within the surface contact water management system   area and groundwater from the underground mine, and treating it to meet water   quality discharge criteria prior to release    Minimizing the use of fresh water through recycling of water to the   extent feasible.  20.3.4.2 Water   Management Overview Contact Water Contact water in the context of the   Brucejack Gold Mine site is defined as water contacting PAG rock exposed   through mining or mine related rock excavation (i.e., the latter occurring   during site preparation for mine surface infrastructure construction). There   are three sources of contact water during operations:  Waste rock deposited in Brucejack Lake  Surface contact water from PAG bedrock   excavations that occurred during site preparation for infrastructure   construction, the largest of these being rock excavation to create the pad   areas for the mill and the Phase 2 Camp    Groundwater seepage to the underground mine. Runoff from the latter   two sources is managed by collection and treatment. All runoff within the   mine site contact water management system is collected in the CWP. This pond   has been sized to contain the runoff volume (50,000 m3) associated with the   24-hour, 200-year return period rain on snow event (The 24-hour 200-year   rainfall has been estimated at 226 mm, while snowmelt potential has been   estimated at 43 mm). The CWP is located near the southwest shore of Brucejack   Lake. Runoff is directed to the facility through a series of contact water   ditches, pipes, and sump collection areas. From the CWP, contact water is   pumped to the WTP, located within the mill building. Treatment of collected   surface contact water began part way through mine construction and will   continue throughout the LOM. The treated water is either used in process or   discharged to Brucejack Lake at depth. The WTP has been designed with a   nominal capacity of 9,600 m3/d. The system is scalable such that additional   units can be added if required. 20-24 

    

 

TECHNICAL REPORT   ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001 |   MARCH 2020 | ISSUED FOR USE Groundwater seepage into the underground workings   is initially sent to the WTP for treatment before being sent to the process   plant, where its use is maximized in process. Excess treated groundwater is   discharged to Brucejack Lake at depth. Diversion Channels Two fresh water   (non-contact) diversion channels divert non-contact water around the core   mine site surface infrastructure area. The Johnson Creek (East) Diversion   Channel drains into Brucejack Lake, while the Camp Creek (West) Diversion   Channel discharges to Brucejack Creek. Process Water Requirements Process   water is required for the tailings slurry to the lake, the underground paste   backfill, the concentrate slurry, and underground mine supply. Process water   is sourced from:  Treated underground   seepage water  Treated contact water   from the CWP  Ore moisture  Water withdrawal from Brucejack Lake at its   outlet. Water withdrawal from Brucejack Lake is required because there are   periods in the winter when groundwater inflows are less than the process   requirement. Details of subaqueous tailings deposition are provided in   Chapter 18.0. Tailings are either directed to the paste backfill plant or   diluted and sent to Brucejack Lake, but never concurrently. A constant flow   (either tailings or water) is required through the tailings pipeline at all   times to prevent a buildup of tailings and blockage of the pipelines;   however, the tailings line to the lake will be operational approximately 60   to 70% of the time. Therefore, when the thickened tailings are being directed   to the paste plant for underground mine paste backfill, fluidizing water is   discharged via the tailings pipeline. 20.3.5 Water Balance A site-wide water   balance model was constructed for the Brucejack Gold Mine in Excel using a   monthly time-step (BGC 2017a,b). A flow schematic of the water balance for   Operations is shown in Figure 20-2. The site-wide water balance model   provides an accounting of project activities at the spatial scale of the mine   site (i.e., the tracking of flows between the Freshwater (FW) Tank, the   Underground Mine, the CWP, the WTP, the Mill, and Brucejack Lake), and also   tracks background and surface water flows from the headwaters of the   Brucejack Lake watershed, downstream to the BJ 1.74 monitoring location,   which is below Brucejack Lake. In addition, the water balance model tracks   volumes of water and mine waste that report to Brucejack Lake over the period   of active mining. For example, the model accounts for the displacement of   lake water resulting from tailings and waste rock deposition and losses of   lake water to tailings voids upon placement in Brucejack Lake. Main sources   of water for ore processing at the Brucejack Gold Mine include water that is   recycled from the mill process, water conveyed by contact water ditches and   surface sumps and reports to the CWP, water that reports to sumps of the   Underground Mine and is pumped to surface, and permitted water withdrawals that   are sourced from Brucejack Creek adjacent the BJ 3.10 weir. Water recycled   from the mill process and that is withdrawn from CWP storage is first treated   prior to being used in the mill. Surplus treated water may be discharged to   Brucejack Lake when mill water requirements are fully met or it is necessary   to manage pond volumes at a certain level. 20-25 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Operational water data   collected in 2018 and 2019 indicates that discharges of treated effluent to   the lake are necessary between May and October because the majority of annual   runoff is realized during these months and water surpluses are encountered at   the CWP. Water that reports to the Underground Mine is captured in sumps and   pumped to surface. Like water sourced from the CWP, sump water is treated   prior to being used in the mill or discharged to the lake when freshwater   supply exceeds mill water demand. A major component of underground sump water   is groundwater recharge that daylights in the mine due to dewatering   activities. Groundwater inflows are seasonally variable, with values being   lower in winter (e.g., February, March), and notable that recharge rates to the   mine are lower than base case predictions indicate (Figure 20-1). In addition   to groundwater recharge, water from the FW Tank in the mill building is also   directed below ground to support mining activities, such as drilling and dust   suppression. Like groundwater recharge, this circulated water reports back to   underground sumps and is pumped to surface for treatment, use in the mill, or   release to the lake. Mill demands and underground mine water requirements   based on the LOM Backfilling – Waste Rock and Mill Tailings schedule   presented in Chapter 16 (refer to Table 16-5 and averages based on the period   2020 through 2028, which corresponds to 3,800 tpd throughput) are summarized   as follows: Concentrate: The model assumes 177 t/d (approximately 5% of total   production) reports to an off-site facility as concentrate for secondary   processing in a slurry of 93% solids by weight. The concentrate demand is   estimated by the model to be 13 m3/d.    Tailings to Brucejack Lake: For years 2020–2028, 2,372 t/d   (approximately 64% of total tailings production), on average, will be   deposited at depth in Brucejack Lake in a slurry of 55% solids by weight   (1,976 m3/d of slurry water).  Paste   Backfill: The model shows 1,213 t/d (including 5 to 6% bonder) will be   deposited in the underground mine in a cemented backfill paste of 60% solids   by weight (873 m3/d of slurry water).    Underground (mine supply) water: Originally estimated in the model to   be 20 m3/hr (BGC, 2017a,b), operational water monitoring data collected in   2019 indicates water demand of the underground mine is on the order of 35   m3/hr (or 840 m3/d) for 3,800 tpd production.    In summary, sources of water comprising the mill water supply are   subject to seasonal changes, and in the case of groundwater recharge,   measured inflows are lower than originally projected. Despite this, Pretivm   has demonstrated an ability to operate at a 3,800 tpd production level while   remaining within permitted limits for reclaim (Table 20-5) and within the   constraints of the existing water management system. Beyond the opportunities   provided by Brucejack Creek reclaim, there is often usable water stored   within the CWP, which provides additional contingency for the mine operation   in terms of water supply. The site-wide water balance model is currently   being updated as part of the 5-Year Mine Plan and Reclamation Program Update   pursuant to permit requirements to consider several years of high-quality   climate, streamflow, and operational water data that have been collected at   the mine site since the water balance was developed. The Brucejack Gold Mine   water quality model is encoded in GoldSim, and there are efficiencies to be   gained by adopting a common software platform for the water balance and water   quality models. Accordingly, a recommended task under the update is to the   encode the site-wide water balance model within a GoldSim environmental   modelling framework, rather maintain the water balance within MS-Excel   software. 20-26 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 20-5: Summary of Water   Withdrawal Data – Brucejack Creek, 2019 Source: Note: Pretivm (2020)   Condition e) of Water License # C500684 (dated November 26, 2018) indicates   the maximum quantity of water that may be diverted for mining/processing ore   is 70 m3/h. 20-27 Month Total Reclaim Water (m3) Average Reclaim (m3/day) Jan   51,072 1,647 Feb 45,230 1,615 Mar 51,633 1,666 Apr 49,979 1,666 May 51,302   1,655 Jun 36,492 1,216 Jul 29,115 939 Aug 33,051 1,066 Sep 39,308 1,310 Oct   51,122 1,649 Nov 50,340 1,678 Dec 51,782 1,670 Total 540,427 1,482 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   I MARCH 2020 I ISSUED FOR USE Figure 20-2: Brucejack Gold Mine Water Balance   Flow Schematic-Operations other area l Creek Creek glacier melt I - - ru ..,   I '"'I la ilings&w !" ": - Cruk loOid losses CampCreek VOK   Source: BGC (2017a) 20-28 I'1\:I TETRA TECH Unnamed other area   waterdisplacedbylakesurfacewid surface runoff Brucejack Brucejackundisturbed   (BJ 1.74)BJ (2.62)runoff baseflows 11 Creek oremoisture / concentrate   groundwater inflows red arrows indicate pm ping routes 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.6 Water Quality Effluent   Permit 107835 (PE-107835), most recently amended December 14, 2018,   authorizes the Brucejack Gold Mine to discharge specified effluents under the   conditions of the permit. PE-107835 specifies maximum concentrations for   certain parameters in WTP effluent discharged to Brucejack Lake (TSS, pH,   aluminum, arsenic, cadmium, cobalt, chromium, copper, iron, lead, manganese,   silver, and zinc) and for the discharge from Brucejack Lake to Brucejack   Creek at the lake outlet (TSS, pH, nitrite, nitrate, ammonia, antimony,   arsenic, iron, and silver). The permit specifies that other parameters should   meet BC Water Quality Guidelines (WQGs) for protection of aquatic life at the   Brucejack Lake outlet. Effluent quality at the Brucejack Lake outlet is also   required to meet federal MDMER. Water quality results from Brucejack Lake   outlet samples in 2019 did not exceed any effluent permit discharge limits or   Metal and Diamond Mining Effluent Regulation (MDMER) limits, and all other   parameters that were monitored were below BC WQGs. Water quality has been   modelled at the Brucejack Lake outlet and at a location in Brucejack Creek   downstream of the lake outlet to provide estimates of water quality during   the mine operations, closure, and post-closure phases. The GoldSim water   quality model derives estimates of contaminant loadings from mine sources   (water from the underground mine, WTP effluent, WTP sludge, sewage treatment   plant effluent, mine tailings, surface runoff from the NPAG Quarry, waste   rock) and combines these with background loadings to derive water quality   predictions. Background water quality was derived from pre-construction   monitoring (ERM Rescan 2014), while mine-related water quality signatures   were based on geochemical source terms developed from geochemical   characterization studies and monitoring data sets reported in annual reports.   Modelled flows were assigned based on the water balance model (Pretivm 2018b,   Appendix C). The modelled monthly flows in the water balance model vary   throughout the year, reflecting site hydrology and hydrogeology. Water   quality predictions were most recently generated for a Base Case and an Upper   Case scenario for the 3800 t/d Mines Act and Environmental Management Act   amendment application (Appendix A of Pretivm 2018b). These model results are   also considered representative of the 2020 updated mine plan, since there was   a negligible change in waste rock volumes as compared to the 3800 t/d model.   The Base Case represents an expected condition, whereas the Upper Case   applies upper case geochemical source terms to all mine-related inputs to the   model. The Upper Case scenario, while not the expected case, was   conservatively used for water quality management planning, such as the design   of the WTP. Water quality monitoring results from the lake outlet are   compared to water quality model results in the Brucejack Gold Mine annual   reports. This comparison has shown that measured concentrations have been   well represented by the Base Case model. The Base Case model predicts that   concentrations at the lake outlet will continue to meet discharge limits or   WQGs throughout the operations, closure, and post-closure phases. At closure,   the Brucejack Gold Mine will be flooded and most of the flow from the   underground mine is modelled to report directly to Brucejack Creek via   subsurface pathways. The Base Case model predicts that Brucejack Creek will   experience periods during closure when arsenic and zinc are slightly above   discharge limits or WQGs, but even if the maximum Upper Case modelled   concentrations are realized, they are not expected to have a significant   effect on aquatic life (Lorax 2018). Iron concentrations are also predicted   to be higher than WQGs in groundwater flowing to Brucejack Creek from the   underground mine. However, it is expected that ferrous iron in groundwater   will oxidize to relatively insoluble ferric iron after entering Brucejack   Creek and form iron-oxyhydroxide precipitates. This precipitation process   will lower the iron concentration in water to concentrations that are below   BC WQGs. Potential effects to aquatic life in Brucejack Creek from iron   precipitates were assessed as having low significance (Pretivm 2015). All   other parameters modelled for closure and post-closure are predicted to have   concentrations that are below discharge limits or BC WQGs. 20-29 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.7 Waste Management   20.3.7.1 Mine Wastes Mine wastes, including waste rock and tailings, are   backfilled in the underground mine workings and deposited subaqueously into   Brucejack Lake, which acts as the waste rock and tailings storage facility as   approved under the mine’s authorizations. Under current authorizations,   3,734,000 t of waste rock and 1,865,000 t of tailings have been deposited in   the waste rock and tailings storage facility through December 2019. Total   mine waste forecast to be produced over the remainder of the LOM is 3,483,000   t of waste rock and 14,754,000 t of tailings, both of which are aligned with   existing authorizations. Additional details of the mine waste handling and associated   rationale are provided in Sections 16.3, 16.5, 18.2.2, and 20.3.2. Table 16-5   tabulates LOM Backfilling – Waste Rock and Mill Tailing. As described in   Section 20.3.2, all waste rock is assumed to be PAG and is deposited either   below the ultimate flooding elevation of the underground mine or under water   in Brucejack Lake to prevent ARD. Subaqueous deposition of waste rock into   Brucejack Lake was previously conducted by Newhawk in 1999, following   underground development by Newhawk. As noted in Section 20.3.1.3, Brucejack   Lake and its downstream drainage are not fish-bearing for a distance of more   than 20 km. 20.3.7.2 Non-hazardous Waste Waste handling facilities located at   the mine site and Knipple Transfer Area are the primary facilities used for temporarily   storing and separating waste. All non-hazardous industrial and domestic solid   wastes are managed in accordance with the mine’s approved Waste Management   Plan and Refuse Incinerator Management Plan to minimize potential adverse   effects to the environment, wildlife, and mine personnel. Non-hazardous waste   is separated for recycling or disposal. On-site disposal of non-hazardous   waste consists of incineration, recycling, and open pit burning. Incineration   of non-hazardous products includes the operation of two authorized high   temperature incinerators located at the Brucejack Gold Mine site and Knipple   Transfer Area. Open pit burning of non-hazardous waste is conducted at   permitted locations at the mine site and at the Knipple and Wildlife camps.   Recycling of non-hazardous material is an important component of waste   management and environmental protection. Personnel at all Brucejack Gold Mine   infrastructure areas participate in the mine’s recycling program, which   reduces the amount of refuse shipped off-site and thereby reduces the   quantity of waste disposed at regional landfills. Recycling of various   materials is implemented at mine facilities, including recyclable containers,   tin cans, batteries, e-waste, cardboard, light bulbs, heavy plastics, metal, aerosol   cans, and electrical wire. Recyclable waste generated on site is transported   off site to local recycling facilities. 20.3.7.3 Hazardous Waste Hazardous   waste generated at the Brucejack Gold Mine is managed in accordance with the   approved Waste Management Plan and the Refuse Incinerator Management Plan,   the Environmental Management Act Hazardous Waste Regulations, and the   Transportation of Dangerous Goods Regulations to protect mine personnel and   the environment. Hazardous wastes generated at the mine site and supporting   infrastructure are temporarily stored in the mine’s waste handling facilities   prior to transport and disposal at licensed off-site disposal facilities.   On-site disposal of hazardous waste is limited but does occur in the form of   incineration of some items and waste oil heat production; both of these are   conducted in accordance with the approved Waste Management Plan and other   applicable requirements under the Environmental Management Act. 20-30 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 20.3.8 Air Emission Control   Since mining occurs underground and mine wastes (tailings and waste rock) are   ultimately stored either subaqueously within Brucejack Lake or backfilled   into the underground mine, combined with the use of electricity as the   primary source of power during operations, rather than on-site generators   using diesel, air emissions are not substantial. There is some fugitive dust   from waste rock handling on the waste rock dump, and seasonally from road   use. There are point source air emissions from the mill and assay lab.   Pretivm implements its approved Air Quality Management Plan to mitigate air   emissions. Key mitigations for fugitive dust from roads include road watering   and application of dust control solution. Emission controls were designed and   implemented for mill and assay lab emission sources and include various   enclosures, ventilation systems, dust collectors, wet scrubbers, fans, and   related appurtenances. These emission controls are also regulated under the   mine’s Air Permit (PA-107025); Pretivm conducts monitoring and maintenance in   accordance with the permit. The Air Permit also regulates operations of the   mine’s incinerators and has conditions specific to fugitive dust, the   underground mine, and the burn pits. 20.3.9 Closure Plan and Costs Following   completion of mining, the Brucejack Gold Mine will be closed, reclaimed, and   monitored in accordance with its authorizations, Reclamation and Closure   Plan, Ancillary Infrastructure Decommissioning and Reclamation Plan, and   other applicable EMS component plans. Closure of the mine site at the end of   operations will include flooding of the underground mine, with continued   water treatment during flooding; removal of all structures and equipment;   closure of the mine portals; and rehabilitation of site disturbances. The   mine has been planned and designed to operate and be closed and reclaimed in   a manner that achieves the approved end land use objectives, returns the site   to as close to its pre-disturbance condition as practical, and minimizes the   potential for long-term adverse effects on the environment. Closure of the   underground facilities will include the removal of material supplies and   mobile equipment, such as ventilation fans and safety equipment. These will   be removed from the site for reuse or will be recycled. Hydrocarbons will be   drained from all equipment and from underground storage and the distribution   system, and disposed in an approved manner. The underground mine workings   will be progressively backfilled with tailings and waste rock throughout mine   operations, to the level of expected water table rebound, and once mining is   completed, the underground will be allowed to flood. The ventilation shafts   and underground portals will be sealed with concrete plugs. The water table   is not expected to reach higher than the elevation of Brucejack Lake. Closure   of the above-ground facilities will include the removal of all buildings and   structures at the mine site and along the Brucejack Access Road. Buildings   will be dismantled, and removable materials will be taken off-site for reuse   or recycling. Concrete pads (mill, Valley of the Kings Zone and West Zone   portal buildings, and West Zone shop) will remain in place, and the Phase 2   Camp supporting pedestals will be cut off at ground level. Oil, fuels, and   processing fluids will be drained from equipment before the equipment is   removed, and disposed of in an approved manner. Processing equipment will be   removed from site and sold or recycled. Above-ground pipes and sediment   curtains in Brucejack Lake and Creek will be removed and disposed in   accordance with the Reclamation and Closure Plan. Post-closure water   management features will be constructed and pad and road surfaces will be   recontoured, decompacted, and revegetated as applicable in accordance with   the Reclamation Plans. Once active water treatment is no longer required, the   transmission line will be dismantled. The steel poles and the conductors will   be removed off-site and sold, recycled, or disposed in an approved manner.   20-31 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The reclamation security for   all infrastructure authorized under Mines Act Permit M-243, including the   mine site, is $31.7 million. An additional reclamation security of $2 million   is held for the Brucejack Access Road under Special Use Permit S25923. There   are other reclamation securities, totaling $70,000, for infrastructure   located on Licenses of Occupation. Due to the limited surface footprint of   the mine and ancillary infrastructure, there are no substantive opportunities   for progressive reclamation that would be used to reduce the Mines Act   reclamation security prior to closure. 20-32 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 21.1 Capital Cost Estimate   21.1.1 Summary The total LOM sustaining capital cost from 2020 to 2032 is   estimated at US$176.7 million. Table 21-1 shows a summary breakdown of the   LOM sustaining capital costs by area, including required sustaining costs for   the mine and mill throughput expansion to 3,800 t/d. The estimated cost   includes design, construction, installation, and commissioning. The key   inputs to this cost estimate were based on the LOM planned costs estimated by   Pretivm and reviewed by Tetra Tech, including recent equipment purchased   costs, equipment quotations from vendors, and recent construction cost data.   All costs are inclusive of direct cost, indirect cost, and contingency. The   expected accuracy range of the operating cost estimate is +20%/-15%. Table   21-1: Summary of LOM Expansion and Sustaining Capital Costs Note: Numbers may   not total due to rounding. 21.1.2 LOM Sustaining Capital Cost Estimate   21.1.2.1 Estimate Base Date This estimate was prepared with a base date of Q4   2019 and does not include any escalation beyond this quarter. 21.1.2.2   Estimate Approach Base Currency The LOM sustaining capital cost estimate was   estimated using US dollars as the base currency. All costs presented in this   section are in US dollars unless otherwise stated. All costs in Canadian dollars   were converted to US dollars using the foreign exchange rate listed in Table   21-2. Table 21-2: Foreign Exchange Rates 21-1 Canadian Currency US Currency   Cdn$1.00 US$0.76 Description Expansion and Sustaining Capital Costs (US$ million) UG Mining 66.6 Processing 3.5 Site Infrastructure 91.8 Mine   Throughput Expansion 14.8 Total LOM Expansion and Sustaining Capital Cost   176.7 21.0CAPITAL AND OPERATING COSTS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Duties and Taxes Duties and taxes are not   included in this estimate. Work Breakdown Structure The estimate is organized   according to the following hierarchical work breakdown structure (WBS): UG   Development UG Infrastructure Site Infrastructure 21.1.2.3 Scope of the LOM   Sustaining Capital Cost Estimate The all-in construction for the LOM   sustaining capital cost estimate from 2020 to 2032 is US$176.7 million. The   cost includes detailed engineering design activities, freight to site, supply   and installation of equipment and structural facilities, and commissioning.   The construction cost is based on information from the construction of the   Brucejack Gold Mine and recent work on the mill dry complex upgrade escalated   to Q4 2019. Major mechanical equipment costs are based on recent purchase   information and quotations from equipment manufacturers. All equipment and   material costs are all inclusive of spare parts, freight, and packaging.   21.1.2.4 LOM Mining Sustaining Capital Cost for Underground Development,   Equipment and Infrastructure Mining sustaining capital cost estimates are   based on ongoing underground development, additional mining equipment   purchases, and underground infrastructure. Underground development includes   ramp and raise development, whereas lateral and stope development are   considered operating costs. Underground development is conducted by Pretivm   and their contractors. Underground infrastructure includes the supply and   installation of high voltage cables for underground development, underground   electrical substation, underground network infrastructure, underground   crusher dust collection, and conveyor transfer dust collection. Table 21-3   summarizes the mining sustaining capital cost estimates and Table 21-4 shows   the year-by-year sustaining cost breakdown for underground operations. Table   21-3: LOM Mining Sustaining Capital Cost Summary 21-2 Description Mining   Sustaining Capital Costs (US$ million) Underground Development 35.6   Underground Equipment 13.1 Underground Infrastructure 17.9 Total LOM Mining   Sustaining Capital Costs 66.6 Mine Throughput Expansion Processing UG   Equipment Description 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 21-4: Mining Sustaining   Capital Costs by Year 21.1.2.5 Processing The scope of work for processing   includes the upgrading and addition of process mobile vehicles and process   equipment, including concentrate container spray system, dust suppression   system, and mobile crane. The total cost for processing is US$3.5 million.   21.1.2.6 Site Infrastructure Brucejack Surface The Brucejack surface includes   the cost of upgrading, supply and installation of a multi-use facility, artic   corridor, new dorm, bulk gravity lab, kitchen loading dock modification,   elevated walkway to VOK, mill roof modification, core facility, warehouse   expansion, fire hall, network system and hardware upgrade, and mobile   equipment addition and replacement. Knipple Site The Knipple site includes   the cost of the upgrading, supply, and installation of a multiple-use   facility, DAL lab fire assay expansion, additional soil treatment facility,   engine replacement, truckshop, wash bay complete with oil water separator,   and Knipple camp upgrades. Bowser Site The Bowser site includes the cost of   the upgrading, supply, and installation of an airstrip, Bowser Lake dock,   boat for spillage response, and lake cleanup. Wildfire Site The Wildfire site   includes the cost of the upgrading, supply, and installation of a   multiple-use facility, project signage at the main gate, workshop, core   facility, fuel storage and containment, camp upgrade, water management and   road deviation work, septic upgrade, and bear fence upgrade. Access Road The   access road area includes the costs of construction for road upgrades, bridge   decking replacement, and maintenance. Other Pending Works/Upgrades Other pending   works/upgrades include costs for the Quonset storage slab, data management   system, safety management system, and support infrastructure upgrades. 21-3   Area 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 Underground Mining   (US$ million) 15.39 18.39 8.56 10.13 4.08 3.49 3.81 2.60 0.11 0.10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The total cost for the mine   site facilities area is US$91.8 million. Table 21-5 shows the year-by-year   sustaining cost breakdown for the site infrastructure upgrading and   construction. Table 21-5: Site Infrastructure Sustaining Capital Costs by   Year 21.1.2.7 Mine Throughput Expansion The mine expansion includes the   upgrading, installation, construction, and commissioning of the underground   service bay and wash bay, flocculant system, flotation circuit, paste plant   binder silo #2, tailings thickener, cyclone addition, upgrading dust   collection systems, apron feeder, 13.8 kV transformer, and rock breaker. The   mine expansion also includes the overhead crane, heavy duty truckshop, core   logging facility, Phase 2 of the mill dry complex, and Wildfire Camp   upgrades. The total cost for the mine expansion is US$14.8 million. 21.1.2.8   LOM Expansion and Sustaining Capital Cost Exclusions The following items are   excluded from this capital cost estimate: Working or deferred capital  Upgrading cost spent prior to 2020  Financing costs  Refundable taxes and duties  Land acquisition  Currency fluctuations  Lost time due to severe weather   conditions  Lost time due to force   majeure  Additional costs for   accelerated or decelerated deliveries of equipment, materials, labor, or   services resultant from a change in project schedule  Any project sunk costs (studies,   exploration programs, etc.)  Mine   reclamation costs (included in financial model)  Mine closure costs (included in financial   model)  Escalation costs  Additional permitting costs not identified   in the estimate  Community relations   (included in financial model).  21-4   Area 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 Site Infrastructure   (US$ million) 18.70 32.35 16.40 7.32 3.55 2.32 3.46 1.73 4.61 1.39 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 21.2 Operating Cost Estimate   21.2.1 Summary The estimated LOM average operating cost is US$162.82/t   milled. Operating costs are defined as the direct operational costs, which   include mining, processing, water treatment, tailings storage, site services,   and general and administrative (G&A) expenses at the Brucejack mine site.   The operating cost estimates exclude product freight costs, sale-related   costs, and royalties, which are included in the economic analysis (Section   22.0). The estimate was based on an average annual plant feed rate of   approximately 1.387 Mt of ore processed (3,800 t/d milled). Table 21-6 shows   the cost breakdown for each area and Figure 21-1 shows the cost distribution.   Table 21-6: LOM Average Operating Cost Summary (1)Includes costs for off-site   and satellite offices. Note: Figure 21-1: Overall Operating Cost Distribution   by Area 21-5 Area LOM Unit Operating Cost (US$/t milled) Mining 70.83   Processing 21.34 Overall Site Services, including Off-site/Satellite   Offices(1) 35.89 G&A 34.76 Total Operating Cost 162.82 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE The operating cost estimates were based on the   Brucejack Gold Mine operating experience, and include consumable supplies,   power supply, contractor services, camp services, worker transportation, and   labour salaries/wages. These costs were estimated with a base date of Q4 2019   and do not include any escalation beyond this quarter. The expected accuracy   range of the operating cost estimate is +15%/-15%. All costs were estimated   in US dollars, unless otherwise specified. Table 21-2 shows the foreign   exchange rates used for the estimate. The operating costs exclude shipping   charges and sale costs for the gold-silver doré and gold-silver concentrate,   as well as royalties, which are included in the economic analysis (Section   22.0). All operating cost estimates exclude taxes unless otherwise specified.   21.2.2 Mining Operating Cost Estimate Mining operating costs include   production costs such as drilling, blasting, explosives, mucking, backfill,   and support costs. Non-capitalized underground development (lateral   development and stope development) are considered operating costs. The   estimated LOM average mining cost is US$70.83/t milled, with a high of   US$100.74/t milled forecast for Q2 of 2020. The estimated mining operating   costs are based on current and forecast contractor rates. Figure 21-2   illustrates the cost distribution. Figure 21-2: Mining Operating Cost   Distribution by Area 21-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 21.2.3 Process Operating Cost   Estimate The estimated LOM average unit process operating cost is US$21.34/t   milled at an average annual plant feed rate of approximately 1.387 Mt of ore   processed, or a nominal plant feed rate of 3,800 t/d, including tailings   delivery. The estimate is based on 12-hour shifts per day, 24 h/d and 365   d/a. The process operating cost estimate includes: Personnel requirements,   including supervision, operation and maintenance, and salary/wage levels,   including burdens, based on Q4 2019 labour rates  SAG mill and ball mill liner and grinding   media consumption  Maintenance   supplies  Reagent consumptions  Other operation supplies  Power consumption for the processing   plant  Other process related costs,   such as mobile equipment, consulting, and general expenses.  Figure 21-3 shows the process operating   cost distribution. Figure 21-3: Process Operating Cost Distribution by Area   21-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 21.2.4 Mine Site G&A and   Site Services Operating Cost Estimate Mine site G&A and site services   costs include expenditures that do not relate directly to mining or process   operating costs. The estimated LOM average unit operating cost is US$34.76/t   milled for mine site G&A and US$35.89/t milled for Site Services, based   on a nominal daily ore plant feed rate of 3,800 t. The mine site G&A and   site service costs include costs related to the satellite site operations at   the Knipple Transfer Station and the mine access security station. In   addition, mine site G&A costs include operation-related costs for the off-site   office in Smithers, BC. Site services costs include: Manpower related costs,   including supervision, operation and maintenance, and salary/wage levels,   including burdens, based on Q4 2019 labor rates  Energy    Operating supplies and consumables    Maintenance supplies  Rental and   lease  Other related costs.  Mine site G&A costs include: Manpower   related costs, including supervision, operation and maintenance, and   salary/wage levels, including burdens, based on Q4 2019 labor rates  Various general operating management and   services related costs, mainly for the following main areas:  General mine site administration -   Environmental and permitting - Procurement and supply chain -   Camp services - Health and safety - Accounting and financial   services - Human resources - IT-related various services -   Worker transportation services. - 21-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 22.1 Introduction Tetra Tech   prepared an economic evaluation of the Brucejack Gold Mine based on a   discounted cash flow model for the remaining 13-year LOM and 15.64 Mt of mine   plan tonnage. The current forecast for the remaining Brucejack Gold Mine LOM   shows a post-tax NPV of US$1.50 billion at a 5% discount rate, and US$1.29   billion at an 8% discount rate. Internal rate of return and payback period   results as referenced by NI 43-101F1 are not relevant to this Technical   Report as mine revenues provide sufficient cash flow to cover expansion   capital and no negative cashflow periods are expected. Table 22-1 shows a   summary of the economic analysis results. Table 22-1: Cash Flow Results   Summary (including Discounted Post-tax NPV) 22-1 Unit Amount Tonnes Mined and   Processed kt 15,637 Gold Head Grade g/t 8.4 Silver Head Grade g/t 59.6 Doré   Production Gold Ounces Produced ‘000 oz 2,617 Silver Ounces Produced ‘000 oz   1,960 Concentrate Production Concentrate Sold ‘000 dmt 882 Gold Contained in   Concentrate ‘000 oz 1,430 Silver Contained in Concentrate ‘000 oz 25,166   Total Project Revenue US$ million $5,266 Operating Costs US$ million (2,546)   Royalties US$ million (63) EBITDA US$ million 2,642 Capital Costs US$ million   (177) Other Expenses US$ million (21) Pre-tax Cash Flow US$ million 2,444   Allowable Tax Deductions US$ million (1,146) Taxable Income US$ million 1,307   Taxes Payable US$ million (492) Post-tax Cash Flow US$ million 1,952 Post-tax   NPV (5% Discount Rate) US$ million 1,496 Post-tax NPV (8% Discount Rate) US$ million 1,293 22.0ECONOMIC ANALYSIS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The Brucejack Gold Mine   economic model is based on the following assumptions: Gold price of   US$1,300/oz  Silver price of   US$16.90/oz  Foreign exchange rate of   Cdn$1.00:US$0.76.  Note that the metal   prices listed above differ from metal pricing used for Mineral Reserve   delineation. Gold price for financial modelling is based on the London   Bullion Market Association (LBMA) AM and PM three-year average for gold   (US$1,306/oz). Silver price is based solely on the three-year average   (US16.32/oz). Pretivm provided current doré and concentrate payment terms,   smelting and refining charges, transportation costs, and insurance costs.   Gold and silver recoveries are based on the Brucejack Gold Mine operational   data and metallurgical test results as discussed in Section 13.0 of this   Technical Report. 22.2 Pre-tax Model The production schedule has been   incorporated into the pre-tax financial model to develop annual recovered   metal production. The annual at-mine revenue contribution of each metal was   determined by deducting the applicable treatment, refining, and   transportation charges (from mine site to market) from gross revenue. Sustaining   capital costs have been incorporated on a year-by-year basis over the LOM and   operating costs were deducted from gross revenue to estimate annual mine   operating earnings. Capital expenditures include ongoing sustaining capital   costs for mining, milling, and site services additions and equipment   replacement, and remaining capital costs completing mine and mill feed   throughput expansion to 3,800 t/d. The total LOM capital cost is US$176.7   million, including US$14.8 million in expansion capital remaining to complete   the throughput expansion. The mine closure and reclamation cost of US$21.2   million has been included in the financial model. Working capital has not   been included in the model, as the Brucejack Gold Mine is currently in   operation and generating positive cash flow. NPV has been estimated at the   beginning of the mining schedule and therefore has an effective date of   January 1, 2020. Table 22-2 shows the metal production quantities and Figure   22-1 shows the annual pre-tax net cash flows (NCFs) and cumulative net cash   flows (CNCFs). 22-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 22-2: Metal Production   Quantities 22-3 Units First Five Years LOM Total Tonnes Milled Mt 6.93 15.64   Average Annual Tonnes Milled Mt 1.39 1.20 Average Grade Gold g/t 8.52 8.35   Silver g/t 11.82 59.60 Total Production Gold ‘000 oz 1,832 4,046 Silver ‘000   oz 2,296 27,096 Average Annual Production Gold ‘000 oz 366.47 311.25 Silver   ‘000 oz 459.30 2,084.31 

    

 

TECHNICAL REPORT   ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001 I   MARCH 2020 I ISSUED FOR USE Figure 22-1: Pre-tax Cash Flow -"2 -"2   .. $400 $2,000 :1 Ql :I c Ql ., $300 $1,500 e" z .... Ill z .(. )(   i" 2020 2021 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2034 2035   2036 2037 s-s- s-s- s-- Offse costs $35 $34 $34 $33 $34 $36 $36 $36 $35 $28   $29 $21 $13 I'1t:I TETRA TECH 22-4 $600 $3,000 ·e$500 $2,500·e 2. ::» c.u0,   a: c u$200 $1,000u " $100 $500 D.. D.. s-s--Revenue$439 $4SS $454$446 $474   $492 $498 $482 $374 $336 $228 $133s-s-s-s- -cash flow$125 $146 $179 $185 $220   $248 $268 $284 $270 5185 $152 $124 $78 SISI $(5) $(9) $(1) $(1) --Operating   costs$257 $250 $245 $246$213 $214 $211 $201 $198 5180 $179 $100 $52 s-s-   s-s-s- --capital costs $50 $53 $25 $17 $8 $6 $4 $551 s-s- s-s-   s-s-s-s--cummulatille cash f low $125 $272 $451 $636$856 $1,104 $1,372 $1,656   $1,926 $2,111 $2,263 $2,387 $2,465 $2,460 $2,455 $2,446 $2,445 $2,444   -Revenue -cash flow--O tingcostsOff site costs --capital costs --currrnulative   cash flow 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 22.2.1 Metal Price Scenarios   Table 22-3 tabulates the economic results at different metal price scenarios.   Table 22-3: Economic Results Summary for Different Metal Price Scenarios   Note:(1)The NPV is discounted to January 2020. 22.3 Smelter Terms The   payment, smelting, and refining terms applied in the economic analysis are   the current contractual terms in effect. 22.4 Markets and Contracts The   Brucejack Gold Mine produces gold and silver doré and concentrates. Doré is   transported to the refineries by air. Concentrate is loaded in customized   bulk containers and transported from the mill site to Knipple Transfer   Station and then to SBT by a third-party trucking company. The bulk   concentrate is then loaded into ocean vessels to international customers.   22.5 Taxation and Royalty Considerations Pretivm completed the post-tax   economic evaluation of the Brucejack Gold Mine, including applicable income   and mining taxes. Based on the metal prices used for this Technical Report,   the total estimated taxes payable on Brucejack Gold Mine profits are   US$491.5million over the 13-year LOM. Table 22-4 shows the various payable   tax components. The Brucejack Gold Mine was evaluated on an after-tax basis   levied as three separate tax contributions at the federal, provincial, and   provincial-mining level (BC Mineral Tax). Table 22-4 shows the pre-and   post-tax breakdowns for these cash flows and the allowable tax deductions.   22-5 Economic Parameter Unit Gold Price (US$/oz) 1,300 1,600 1,900 Silver   Price US$/oz 16.90 20.80 24.70 Net Cash Flow US$ billion 2.44 (pre-tax) 1.95   (post-tax) 3.70 (pre-tax) 2.75 (post-tax) 4.96 (pre-tax) 3.55 (post-tax)   NPV(1) (at a 5.0% discount rate) US$ billion 1.80 (pre-tax) 1.50 (post-tax)   2.75 (pre-tax) 2.13 (post-tax) 3.70 (pre-tax) 2.76 (post-tax) Exchange Rate   Cdn$:US$ 0.76 0.76 0.76 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001   | MARCH 2020 | ISSUED FOR USE Table 22-4: LOM Taxes Summary The following   general tax regime is recognized as applicable as of the effective date of   this Technical Report. 22.5.1 Canadian Income Tax System The Canadian federal   income tax rate is 15%. 22.5.1.1 Machinery and Equipment Prior to 2021,   assets purchased prior to commercial production are added to a Class 41(a)   pool and are deducted at an accelerated rate, at up to 100% of the balance,   to the extent of taxable income from the mine. Changes from the 2013 federal   budget phases out the accelerated deduction over the years 2017 to 2020. One   hundred percent of the accelerated rate will be permitted from 2013 to 2016,   90% in 2017, 80% in 2018, 60% in 2019, and 30% in 2020. Assets purchased after   the start of production are added to a Class 41(b) pool and are deducted at   up to 25% of the balance. 22.5.1.2 Mine Acquisition Costs Mine acquisition   costs include costs of land, exploration and mining rights, licenses,   permits, and leases. These costs are added to a Canadian Development Expense   (CDE) pool and can be deducted at up to 30% of the balance in a year.   22.5.1.3 Pre-production Mine Expenditures Pre-production mine expenditures   include both exploration and mine development costs. Prior to 2015,   exploration and mine development are added to a Canadian Exploration Expense   (CEE) pool. One hundred percent of the balance can be deducted in a year, but   the deduction is also limited to the income from the mine. 22-6 Cash Costs   LOM Total (US$ million) Pre-tax NCF 2,444 Taxable Income 1,307 Federal Taxes   187 Provincial Taxes 157 BC Mineral Tax 148 Post-tax NCF 1,952 Post-tax NPV   (at a 5% Discount Rate) 1,496 Post-tax NPV (at an 8% Discount Rate) 1,293 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Pre-production mine   development costs incurred subsequent to 2017 are treated as CDE instead of   CEE. The transition started to be phased in beginning in 2015, with 20% of   costs being allocated proportionately to CDE and 80% to CEE in 2015, 40% to   CDE and 60% to CEE in 2016, and 70% to CDE and 30% to CEE in 2017. 22.5.2   Provincial (BC) Mining Tax System The BC provincial income tax rate is 12%.   22.5.2.1 Net Current Proceeds Tax A 2% tax is levied on an amount by which   gross revenues exceed current operating costs. Hedging income and losses,   royalties, and financing costs are excluded. Capital costs including   exploration, pre-production development, and leasing are excluded. Capital   costs are relevant for Net Revenue Tax. The net current proceeds tax is added   to a cumulative tax credit account (CTCA) and is available to offset net   revenue tax payable. 22.5.2.2 Net Revenue (13%) Tax Tax is levied at 13% of   net revenue. All capital expenditures, both mine development costs and fixed   asset purchases, are accumulated in a cumulative expenditure account (CEA).   Net revenue is defined as 13% of gross revenues less the current operating   costs for the year, less any accumulated CEA balance. Therefore, for net   revenue tax, all current and capital expenditures are fully deductible in the   year they are incurred or in the following year. Net revenue does not become   assessable until the costs of all preproduction capital expenditures have been   recovered. A “new mine allowance” is also provided to encourage new mine   development in BC. The allowance allows a mine operator to add 133% of its   capital expenditures incurred prior to commencing production to the CEA   account if the mine began producing minerals in reasonable commercial   quantities before January 1, 2016. BC mineral taxes are deductible for   federal and provincial income tax purposes. 22.6 Royalties The Brucejack Gold   Mine was evaluated under the assumption of the following royalties: First   Nations royalty  Mineral royalty.  The estimated value of the LOM royalty cost   for the First Nation groups is US$14.7 million. 22.7 Sensitivity Analysis A   sensitivity analysis was performed on the financial model considering   variations in: Metal prices  Mining,   processing, and site services operating costs.  The analysis shows that the Brucejack Gold   Mine NPV is most sensitive to changes in gold price and less sensitive to changes   in silver price. The Brucejack Gold Mine has similar sensitivity to grade as   to metal pricing. 22-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 22-2 illustrates the   sensitivity of the Brucejack Gold Mine economics to metal price fluctuations   and Figure 22-3 illustrates the sensitivity to operating costs. The economics   are most sensitive to operating costs. Figure 22-2: Post-tax NPV Sensitivity   to Metal Prices -0 ·c-: z )( 51,400 $1,200 Ui 0 ['n;I 22-8 TETR A TECH $2,000   $1,894 51,800 "c:'$1,600 $1,521 ·-$1,470Siver Pnce > -"'"   Q;,$1,090 $1,000 $800 -15% -10%-5% 0% 5% 10%15% Change from base case 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 I MARCH 2020 I ISSUED FOR USE Figure 22-3: Post-tax NPV   Sensitivity to Operating Costs ['n;ITETRA TECH 22-9 $1_600 $1,550 - Mining   cost $1,500Processing cost $1,479 - Site Setvices $1,4SO $1,435 $1,4UU -10%   0% lOo/u Sensitivity (+/-10%) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE The following subsections   describing adjacent properties are based on information publicly disclosed by   the Owner or Operator of the adjacent property and were sourced as per the   notes in the relevant sections. The QP has been unable to verify the   information for any of the described adjacent properties except against what   has been publicly reported, and the information is not necessarily indicative   of the mineralization at Brucejack. 23.1 Snowfield Property The Snowfield   Property, held by Pretivm for future development of the Snowfield Deposit, is   considered a separate property to the Brucejack Property. It was 100% owned   by Newhawk and was not part of the joint venture that explored the Brucejack   Property prior to the purchase of Newhawk by Silver Standard. The Snowfield   Deposit is located approximately 7 km north of the Brucejack Deposit. This is   reported to be a near surface, bulk tonnage gold-copper porphyry deposit with   significant credits in silver, molybdenum, and rhenium. Mineral Resources are   estimated at 1,370.1 Mt Measured and Indicated with a further 833.2 Mt in the   Inferred category (Table 23-1). (Puritch et al. 2011) Table 23-1: February   2011 Snowfield Mineral Resource Source: Puritch et al. (2011) 23.2 Bowser   Property The Bowser Property is a group of Pretivm mineral claims covering approximately   1,200 km2 that extend from the eastern boundary of the Brucejack Property to   east of Highway 37 and south from Treaty Creek to Long Lake. Exploration by   Pretivm has included airborne electromagnetic, magnetic, hyperspectral, and   radiometric geophysical surveys, ground geophysical surveys, extensive   sampling, prospecting, and geological mapping over much of the property and   diamond drilling on select mineralized zones. Exploration results have   highlighted several distinct areas for focused exploration. The A6 Zone is   located approximately 14 kilometers northeast of the Brucejack Mine, where   prospecting and mapping in 2018 outlined an area of pillow basalts and   mudstones, consistent with stratigraphy in a paleo-rift environment. Drilling   in 2019 identified a buried rhyolite dome capped by mudstones anomalous in   arsenic and mercury. The rhyolite dome is intensely sericite altered, hosts   pyrite stringer zones, and locally contains anomalous copper and silver. The   stratigraphy, alteration, and geochemistry are all consistent with an   Eskay-Creek style volcanogenic massive sulphide system in A6. 23-1 Resource   Category Tonnes (Mt) Average Grades Contained Metal Au (g/t) Ag (g/t) Cu (%)   Mo (ppm) Re (ppm) Au (Moz) Ag (Moz) Cu (Blb) No (Mlb) Re (Moz) Measured 189.8   0.82 1.69 0.09 97.4 0.57 4.983 10.332 0.38 40.8 3.5 Indicated 1,180.3 0.55   1.73 0.10 83.6 0.50 20.934 65.444 2.60 217.5 19.0 Measured & Indicated   1,370.1 0.59 1.73 0.10 85.5 0.51 25.917 75.776 2.98 258.3 22.5 Inferred 833.2   0.34 1.90 0.06 69.5 0.43 9.029 50.964 1.10 127.7 11.5 23.0ADJACENT PROPERTIES   

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Several gold and silver   epithermal targets have been identified in the American Creek Zone located   approximately 25 km southeast of the Brucejack Gold Mine. The American Creek   valley is dominated by kilometer-scale north-south structures and localized   east-west stockworks, which host elevated gold values in rocks of the Lower   Hazelton Group, Unuk River Formation, the same formation that hosts the   Brucejack Gold Mine. The Koopa Zone, located approximately 30 km   east-southeast of the Brucejack Gold Mine, hosts a structurally controlled   quartz + pyrite + arsenopyrite vein system in intensely sericite altered   Iskut River Formation mafic tuffs. The Bluffy Zone, located 30 km   south-southeast of Brucejack Gold Mine, contains broad zones of low-grade   gold hosted in shear zones, which contain narrow veins of high-grade gold and   base metal values. 23-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 23-1: Detailed   Geological Map of KSM-Brucejack Area and McTagg Anticlinorium and Section   Locations Note:The legend can be found in Figure 23-2. Source: Nelson and   Kyba (2014) 23-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Figure 23-2: Legend for   Detailed Geological Map of KSM-Brucejack Area and McTagg Anticlinorium and   Section Locations Source: Nelson and Kyba (2014) 23-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 23.3 Kerr-Sulphurets-Mitchell   Property Adjacent to the west and north of Brucejack/Snowfield Properties   lies the Seabridge Gold Inc. (Seabridge Gold) KSM Property. The KSM Property   hosts four copper-gold mineral deposits: Kerr, Mitchell, Sulphurets, and Iron   Cap. All of these deposits are situated within the KSM mining lease and claim   holdings that are reported to be, at the time of writing this report, 100%   owned and operated by Seabridge Gold. Seabridge Gold acquired the KSM   Property from Placer Dome in June 2000. In March 2019, Seabridge Gold   published an updated NI 43-101 Technical Report detailing estimated Mineral   Proven and Probable Reserves of 2.2 Bt of gold, copper, silver, and   molybdenum ore. Table 23-2 is the published Proven and Probable Reserve   Estimate and Table 23-3 is the published Measured plus Indicated Mineral   Resource (http://seabridgegold.net). The resource estimate is based upon a   combination of open pit and block caving mining methods. Over the entire LOM,   ore will be fed to a flotation mill, which will produce a combined   gold/copper/silver concentrate. The concentrate will be transported by truck   to the nearby deep-water sea port at Stewart, BC for shipment to a Pacific   Rim smelter. Extensive metallurgical testing confirmed that KSM could produce   a clean concentrate with an average copper grade of 25%, making it readily   saleable. Separate molybdenum concentrate and gold-silver doré will be   produced at the KSM processing facility. (http://seabridgegold.net) Table   23-2: March 2019 KSM Property Mineral Reserve Note: Cut-off values and mining   methods used to report the Mineral Reserve Figures were defined based as   Cdn$9 NSR for open pits and Cdn$16 NSR for underground. The reader should   refer to the information provided by Seabridge Gold to get an accurate   appreciation of the definition of the cut-off values for reporting.   http://www.seabridgegold.net/resources.php. Source: 23-5 Zone Reserve   Category Average Grades Contained Metal Au (g/t) Cu (%) Ag (g/t) Mo (ppm) Au   (Moz) Cu (Mlb) Ag (Moz) Mo (Mlb) Mitchell Proven 0.68 0.17 3.1 59.2 10.1   1,767 45 60 Probable 0.58 0.16 3.1 50.2 17.4 3,325 95 104 Iron Cap Probable   0.49 0.20 3.6 13.0 3.5 983 26 6 Sulphurets Probable 0.59 0.22 0.8 51.6 5.8   1,495 8 35 Kerr Probable 0.22 0.43 1.0 3.4 2.0 2,586 9 2 Total 0.55 0.21 2.6   42.6 38.8 10,155 183 207 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 23-3: March 2019 KSM   Property Measured and Indicated Mineral Resources Note: Cut-off values and   mining methods used to report the Mineral Reserve Figures were defined based   as Cdn $9 NSR for open pits and Cdn$16 NSR for underground. The reader should   refer to the information provided by Seabridge Gold to get an accurate   appreciation of the definition of the cut-off values for reporting.   http://www.seabridgegold.net/resources.php. Source: 23.4 Treaty Creek   Property Tudor Gold Corp. owns a 60% interest in the Treaty Creek Property,   with American Creek Resources Ltd. owning a 20% carried interest, and Teuton   Resources Corp. owning a 20% carried interest with a 0.98% royalty interest   in the core portion of the property and a 0.49% royalty interest in the   periphery claims (http://www.teuton.com; http://www.americancreek.com). The   Treaty Creek Property adjoins directly northeast of Seabridge Gold’s KSM   gold-copper property and is underlain by a similar geology. The Treaty Creek   area has a long history of exploration, including extensive sampling and   diamond drilling, dating back to its discovery in 1928 (Pardoe 2016).   Exploration work uncovered several zones, the most promising of which are the   Copper Belle (porphyry-style), GR2 (feeder zone to a VMS), Eureka   (porphyry-style with a gold-silver epithermal overprint), and Treaty Ridge   (VMS/Sedex?) zones. There are no public reports of Mineral Resources or   Mineral Reserves. 23.5 Catear Catear (Goldwedge) is a small 8.7 ha mining   lease, mineral tenure 301579, held by Goldwedge Mines Inc. It is located 2.2   km northwest of Brucejack Gold Mine on the south edge of mineral tenure   509397. Discovered in 1978, gold mineralization is hosted in a quartz vein   and veinlet stockwork within andesite tuffs and lapilli tuffs of the Lower to   Middle Jurassic Lower Hazelton Group. Although estimates of the contained   mineralization are reported for two zones, these have not been prepared in   accordance with NI 43-101 guidelines and are therefore not considered as   current estimates for Catear. The estimates are presented here for   information purposes only, and the reader is cautioned not to rely on them:   Discovery Zone 34,451 t, grading 37.0 g/t Ag and 21.5 g/t Au; and Golden   Rocket Zone 289,500 t, grading 38.3 g/t Ag and 27.4 g/t Au. Mining of the   Golden Rocket Vein reportedly was undertaken in 1988 with ore processing   through an on-site mill. No records of production are available.   (http://minfile.gov.bc.ca/Summary.aspx?minfilno=104B%20%20105) 23-6 Zone   Tonnes (Mt) Average Grades Contained Metal Au (g/t) Cu (%) Ag (g/t) Mo (ppm)   Au (Moz) Cu (Mlb) Ag (Moz) Mo (Mlb) Mitchell 1,794.7 0.57 0.16 3.1 58 34.31   6,638 179.053 230 Iron Cap 422.6 0.41 0.22 4.6 41.0 5.576 2,051 62.559 38   Sulphurets 381.6 0.58 0.21 0.8 48 7.116 1,766 9.815 40 Kerr 378.4 0.22 0.41   1.1 5 2.692 3,445 13.909 4 KSM Total 2,977.3 0.52 0.21 2.8 54 49.694 13,900   265.336 312 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 24.1 Health, Safety,   Environmental and Security A fully-integrated health, safety, and   environmental (HSE) program has been implemented to help achieve a   “zero-harm” goal by Brucejack Gold Mine. To achieve this goal, all key   project stakeholders have been responsible for providing leadership and   committing to the highest HSE standards and values. The development of HSE   practices has required a high level of communication, motivation, and   involvement, including alignment with site contractors on topics such as   safety training, hygiene, ergonomics, hazard awareness, and risk assessment.   Tools have been implemented for performance tracking and accountability,   including procedures for incident management. Established capture and   containment guidelines are followed for the responsible management of process   flows, effluent, and waste products. Environmental protection is incorporated   in the operation of the main processes of the plant as well as in the   transportation, storage, and disposal of materials within and outside of the   boundaries of the Brucejack Gold Mine. 24-1 24.0OTHER RELEVANT DATA AND   INFORMATION 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 25.1 Geology The Brucejack   Deposit is interpreted to be a deformed, porphyry-related transitional to   intermediate sulphidation epithermal high-grade gold-silver deposit that was   formed between 184 and 183 Ma in an active island arc setting similar to the   modern-day Philippines. The Brucejack Deposit has many characteristics in   common with carbonate-base metal gold deposits from the southwest Pacific   Rim. Intermediate sulphidation epithermal deposits are considered to be a   sulphide-rich sub-type of carbonate-base metal gold deposits by workers in   the southwest Pacific Rim region. High-grade gold-silver mineralization was   formed in association with a telescoped, multi-pulsed magmatic-hydrothermal system   beneath an active local volcanic center. This resulted in the overprinting of   earlier porphyry alteration and mineralization, which includes low-grade gold   mineralization, by later co-spatial epithermal veining and mineralization,   including the high-grade gold mineralization. As a result, the precious metal   grade distributions at the Brucejack Deposit are inherently mixed and   unresolvable by domain generation alone. Electrum occurs as clots and   dendritic aggregates hosted in sub-vertical, nominally east-west trending   quartz-carbonate and carbonate vein stockwork. Infill drilling and mine   development have shown that there are corridors of higher-grade east-west   trending electrum mineralization within the broader stockwork zones. This   represents an opportunity for selectively using longitudinal mining. Recent   research has shown that precious metal mineralization was predominantly   transported as colloidal suspensions, with transportation as dissolved metal   complexes likely accounting for only a small component of the metal flux.   Controls on electrum precipitation appear to be fluid mixing, decreasing   temperature, local boiling, and local colloidal aggregate destabilization   near pyrite-rich zones. Colloidal flocculation as a function of these   controls appears to be concentrated along faults, fractures, pre-existing   foliation planes, and along lithological contacts. This explains the lack of   a geochemical proxy for precious metal mineralization at the Brucejack   Deposit. Brownfields exploration work has indicated the presence of at least   two porphyry mineralization targets on the Brucejack Property: the Bridge   Zone and the Flow Dome Zone. Recent work suggests that the Flow Dome Zone may   be the surface expression of the porphyry system that drove the development   of the epithermal mineralization in the Brucejack Deposit. The Bridge Zone   porphyry system is older (approximately 191 to 189 Ma) and is similar to the   Snowfield-Mitchell system. Additional exploration is currently targeting the   Flow Dome Zone. The Brucejack Deposit is currently focused on the Valley of   the Kings Zone and the West Zone. Similar epithermal vein-hosted precious   metal mineralization is present throughout the 5 km by 1.5 km wide arcuate   band of phyllic alteration on the Brucejack Property (e.g., Gossan Hill Zone,   Shore Zone, SG Zone, Golden Marmot Zone, and Hanging Glacier Zone). This   alteration and mineralization band has yet to be explored in sufficient   detail for resource estimation, and represents upside potential on the   property. 25.2 Mineral Resource An updated Mineral Resource, effective date   January 1, 2020 has been prepared for the Brucejack Deposit, incorporating   information from additional tightly-spaced infill drilling, mapping of   underground geological exposures, and mine production. The Mineral Resource   is based on the January 2020 resource model, comprises the April 2012   resource estimate for the West Zone and the January 2020 resource estimate   for the Valley of the Kings Zone. The Valley of the Kings Zone herein can be   apportioned into three discrete areas: 1) the region where estimates 25-1   25.0INTERPRETATION AND CONCLUSIONS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE have been updated with the   new drilling, mapping, and mine production information for the year 2019, 2)   a region beyond this update but still within the January 2019 update area,   where the January 2019 resource estimates remain, and 3) the regions outside   of this, where the December 2013 resource estimates have been preserved. The   January 2020 Mineral Resource is reported inclusive of Mineral Reserves and   exclusive of material mined to December 31, 2019. Data validation by the QP,   as used for the preparation of the Mineral Resource, confirmed that the   drilling data were of suitable quality for use in resource estimation.   Furthermore, the QP has confirmed that the geological and domain   interpretations were representative of the nature and style of mineralization   in the deposit, and were appropriate for the estimation of mineral resources.   The same estimation methodology used in the preparation of previous resource   estimates for the Brucejack Deposit was followed in the generation of the   January 2020 Mineral Resource. The non-linear split population-based   approach, which includes the estimation of high-grade, low-grade, and   probability of high-grade variables separately using a combination of   multiple indicator and ordinary kriging, prior to recombining these into   final gold and silver estimates, is currently considered the most appropriate   method for estimating the mixed and positively-skewed precious metal   mineralization at Brucejack. Alternative techniques are continually evaluated   as more information becomes available. The most significant variations to the   resource model for 2020 are new drill data, updates to the estimation   parameters, and the use of a 10 m by 10 m by 10 m block size for reporting   the Mineral Resource. The change in block size reflects an appropriate scale   to the block size being considered for mining. The resource model was   validated against input drillhole data and mine production for the year 2019   and found to provide a reasonable to good representation of the input data   and production information. The resource model was classified as Measured,   Indicated, and Inferred in accordance with CIM (2014) Definition Standards. In   addition, Pretivm expects that Measured Resources are to be within 15% of   mine production on a quarterly basis, and Indicated Resources are expected to   be within 15% of mine production on an annual basis. Shorter-term   reconciliation is not considered appropriate given the highly variable and   nuggety nature of the precious metal mineralization at Brucejack. Inferred   Resources cannot be converted to Mineral Reserves as there is insufficient   confidence in the estimate to support mine planning. They are, however,   useful for resource definition drill targeting. Looking at the January 2020   resource model retrospectively, the overall tonnes and grade reported from   production in 2019 were within 10% of those reported from the 2020 resource   model from within the mined outlines. The January 2020 Mineral Resource   effectively overwrites the January 2019 Mineral Resource inside the newest   update area. Comparisons between these models (inclusive of mine production)   show that the new estimate is lower by approximately 0.7 Mt, 2.2 Moz Au, and   1.1 Moz Ag in the Measured + Indicated Resource at similar estimated gold and   silver grades, using the same cut-off grade of 5 g/t AuEq (AuEq = Au + Ag /   53) and after depletion. The differences between the two models are largely   driven by additional tightly-spaced infill drilling. The January 2020 Mineral   Resource of the Valley of the Kings Zone is reported above a cut-off grade of   3.5 g/t gold; differing from the previous reporting above a gold equivalent   of 5 g/t AuEq cut-off (calculated as AuEq = Au + Ag / 53) used in the   November 2012 (Jones, 2012c), December 2013 (Jones, 2014), July 2016 (Board   et al., 2017), and January 2019 (Pretivm, 2019) Mineral Resources. The   decision to report the Mineral Resource at a lower cut-off grade is based on   a comparison between actual mining practice and results and the resource   model. 25-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 25.3 Mineral Reserves The   revision to Mineral Reserves is driven by the updated Mineral Resources.   Measured and Indicated Mineral Resources that fall within planned mining   shapes have been converted to Mineral Reserves. Adjustment factors applied to   the Mineral Resources to convert to Mineral Reserves include estimation of   mineable shapes, dilution, and mining losses alongside grade reconciliation   calculations. Mineral Reserves are delineated using a cut-off grade of   US$180/t. In the 2020 Mineral Reserve update, a MCF was included in Reserve   calculations. As the MCF is based upon historic mining data of previous   resources, it is only applied to the areas of the current resource that have   not been updated. The MCF is based on the stope grade and drillhole spacing   within each designed stope. Areas with closer drillhole spacing, and   therefore higher grade confidence, are capped at a higher grade than areas   with lower drillhole spacing to avoid potentially overstating grades in areas   with lower statistical confidence. This MCF calculation has shown an   improvement in reconciliation between resource estimated and mined grades   prior to recovery and dilution estimates. 25.4 Mining 25.4.1 Underground Mine   Geotechnical SRK undertook a geotechnical review and evaluation of the   Brucejack Gold Mine Project that included a review of historic geotechnical   data, underground excavation conditions, stope performance, and structural   geology to support the confirmation of underground mine design and   geotechnical design guidelines. These guidelines included excavation design   parameters, estimates of dilution, as well as ground support requirements.   The stopes and underground infrastructure excavations are performing well.   The design excavation dimensions are appropriate for the observed and   anticipated ground conditions. Major structural features, such as the Rainy   Fault, and associated secondary structures are impacting excavation   performance, but ground conditions are managed well using the ground support   described in this report and through local geotechnical assessment by mine   personnel when required. 25.4.2 Mining Methods The current mining operation   has proven mining performance at 3,800 t/d. The mine is equipped and staffed   to continue mining of the reserves as planned. Ongoing reconciliation, cavity   monitoring, and data collection provide feedback to the geology, mine   planning, and operational teams to improve mining performance. The current   mine plan includes accelerated development in the Valley of the Kings Zone in   order to sustain sufficient working areas for targeted production. The nature   of the mineralization results in a degree of variance between planned tonnes   and grade over short time periods. As mining continues, the nature of the   mineralization and degree of variance will be better understood, which will   enable better forecasting of short-and long-term production. Continued use of   MCF calculations going forward is expected to further improve grade   reconciliation during mine planning. 25-3 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 25.4.3 Waste Rock Bathymetric   surveys, geotechnical site characterization, numerical assessment, back   analysis, and continuous observation has been used to design the waste rock   dump, including deposition on tailings. The observational method (Terzaghi   and Peck 1967; Peck 1969) coupled with rigorous SOPs and QPOs documented in a   comprehensive OMS Manual ensures continued safe operation of the dump. This   dumping procedure is independent of the Brucejack Lake bed sediment (and   tailings) thickness or strength, because it assumes that the foundation   cannot initially carry the load whether it is due to sediment (and tailings)   thickness or strength (or both). Annual geotechnical inspections have been   carried out by SRK on the waste rock dump (and tailings deposition) between   2016 and 2019. In addition, an Independent Tailings Review Board (ITRB),   appointed by Pretivm, completed annual inspections at this same time. All inspections   have consistently confirmed that the operational practices by Pretivm was   appropriate for the site conditions, and that Pretivm staff was well informed   of the procedures necessary to continue safe waste rock dumping. 25.5 Mineral   Processing and Metallurgical Testing 25.5.1 Metallurgical Testing The   Brucejack Deposit mineralization typically consists of a significant portion   of gold and silver present in the form of nugget or metallic gold and silver,   especially for the Valley of the Kings ore. Extensive metallurgical testing   programs have been conducted on the Property since 1988, with major   metallurgical test work performed between 2009 and 2014 to support the design   and construction of the 2,700 t/d process plant for the Brucejack Gold Mine.   The mill began commercial operation at the designed capacity in Q4 2017. In   general, the mill feed is amenable to the process flowsheet designed,   including gravity concentration and flotation concentration to produce a doré   product and a flotation concentrate. On average, the gravity concentration   circuit produced a much better gold recovery, compared to the results   produced from the laboratory trials. In 2018, to increase the mill feed rate   to 3,800 t/d, various test work, circuit simulations, and review work were   conducted to assess the opportunities and bottlenecks for further improvement   of the mill performance and throughput. 25.5.2 Mineral Processing The 2018   mill capacity review work and the 2019 operation indicate that with some   modifications, the process plant is capable of achieving the planned   throughput of 3,800 t/d. The new third cleaner cell and the new flocculant   preparation system are being installed and it is expected the upgrading would   improve cleaner circuit and tailings and concentrate dewatering circuit   performances. The upgraded flowsheet is same as the existing operation,   including the following components:    One stage of crushing in underground    A 2,500 t SAG mill feed surge bin on surface  A SABC primary grinding circuit equipped   with a gravity concentration circuit    Rougher flotation and scavenger flotation of hydrocyclone overflow   25-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Three stages of cleaner   flotation on combined rougher and scavenger concentrates  Flotation concentrate dewatering  Flotation tailings dewatering   circuits.  The mill feed ore is crushed   and ground to the particle size of 80% passing approximately 90 to 100 μm.   Two gravity centrifugal concentrators, together with two upgrading tables and   associated one gravity centrifugal concentrator, recover the free nugget gold   grains from the ball mill discharge. The resulting gravity concentrate is   further refined in the gold room on site to produce gold-silver doré. The   hydrocyclone overflow, containing gold and silver bearing sulfide minerals,   from the primary grinding circuit is floated by rougher and scavenger   flotation. The resulting rougher flotation concentrate and scavenger flotation   concentrate are further upgraded in three stages of cleaner flotation. The   first cleaner scavenger flotation tailings report to the rougher scavenger   flotation for further recovering the residual gold and silver bearing   sulphides. The third cleaner concentrate, or the final flotation concentrate,   is dewatered by a high-rate thickener and a tower-type filter press prior to   being loaded in customized bulk containers for shipping. The final rougher   scavenger flotation tailings are dewatered in a deep cone thickener.   Approximately 30 to 40% of the flotation tailings is used to make paste for   backfilling the excavated stopes in the underground mine, and the balance is   pumped to Brucejack Lake where the tailings is stored under water. The   concentrate and tailings thickener overflows are recycled as process make-up   water. 25.6 Environmental 25.6.1 Geochemistry The geochemistry of Brucejack   Gold Mine rocks has been and continues to be assessed through comprehensive   characterization studies (refer to Section 20.3.2) and ongoing monitoring   programs. The geochemical data sets have been used to inform waste management   plans and to predict associated water quality. The main conclusions of the   geochemistry assessment are summarized as follows:  A significant portion (49%) of surface   waste rock samples are characterized as PAG with enrichments (greater than   10x average continental crust) in silver, gold, manganese, antimony, and   selenium. Saturated column tests indicate that subaqueous storage of surface   waste rock in Brucejack Lake will minimize any potential leaching and changes   to Brucejack Lake water quality.  The   majority of underground waste rock samples (83%) at the Brucejack Gold Mine   are PAG; however, most of the rocks have considerable neutralization potential,   which is predicted to delay the onset of ARD for decades or more. Leachate   results from humidity cell tests and field bin studies confirm this   assertion. This is also supported by the observation of alkaline mine waters   and no indication of increasing concentrations of dissolved metals associated   with the onset of ARD (e.g., cadmium, cobalt, copper, iron, zinc, as   predicted by kinetic tests) since gold production commenced in June   2017.  The Brucejack Gold Mine ore is   characterized as PAG, whereas tailings generated from the mill are generally   characterized as NPAG. The tailings samples have elevated concentrations of   silver, arsenic, cadmium, manganese, and selenium, compared to continental   crust; however, saturated column test results indicate that subaqueous   storage of tailings in Brucejack Lake or in the underground mine below the   post-closure final water table elevation will minimize metal leaching.  NPAG quarry rock samples are consistently   NPAG with low metal leaching potential. 25-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE WTP sludge is characterized   as NPAG with elevated concentrations (greater than 10× average continental   crust) of silver, arsenic, cadmium, manganese, molybdenum, antimony, and   selenium. Based on static and kinetic tests, WTP sludge is predicted to be   stable over a range of pH and redox conditions.  The results of the geochemistry assessment   indicate that water, waste rock, and tailings are being managed appropriately   to minimize environmental risk. 25.6.2 Hydrogeology A calibrated,   three-dimensional, numerical hydrogeologic model, developed for environmental   assessment and permitting applications in 2015, was used to estimate the   inflow of groundwater to the Brucejack Gold Mine underground mine workings.   These flow estimates were based on a 2700 t/d mine plan as presented in the   2014 FS (Ireland et al. 2014). The average annual rate of groundwater inflow   to the underground workings was predicted to vary between 2,500 and 2,900   m3/d and to increase to between 2,900 to 3,500 m3/d with initiation of mining   in the West Zone (Section 20.3.3). However, the observed average annual   underground dewatering rate (a proxy for measuring groundwater inflow rate to   the mine) from 2016 to 2019 was 1,280 m3/d, which suggests that actual inflow   rates may remain between the simulated base case and the low K scenarios   (Figure 25-1). Figure 25-1: Simulated vs. Observed Inflow Rates 25-6 Monthly   Underground Inflow (m3/d) 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0   Jan-16 Dec-16 Dec-17 Dec-18 Jan-20 Dec-20 Dec-21 Dec-22 Jan-24 Dec-24 Dec-25   Dec-26 Jan-28 Dec-28 Dec-29 Dec-30 Observed UG Flows 2015 Base Case (2700   t/d) 2015 Low K Case (2700 t/d) 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Potential factors causing the   difference between the 2015 calibrated base case simulated inflows and observed   inflows include but are not limited to the following: The bulk rock mass   hydraulic conductivity is lower than simulated for the base case  Differences between simulated and actual   rates and depth of mine development    Seepage mitigation measures employed during mining (e.g., grouting of   higher producing zones)  Some   combination of these factors.  The   groundwater model is currently being updated to support the 2020 5-Year Mine   Plan and Reclamation Program Update pursuant to permit requirements. The 2020   groundwater model will be re-calibrated to a longer record of dewatering and   groundwater levels (up to the end of 2018), incorporating accurate as-built   data and the current mine plan (Jones et al. 2019). The recalibration will   include adjustments to recharge and bedrock K and consideration of grouting   of faults. 25.6.3 Water Management There are three sources of contact runoff   during operations: Waste rock deposited in Brucejack Lake  Surface contact water from PAG bedrock   exposed during infrastructure construction, the most significant being rock   excavation to create the pad areas for the mill and the Phase 2 camp  Groundwater seepage to the underground   mine.  Runoff from the latter two   sources is managed by storage and treatment. All runoff within the Brucejack   Gold Mine site contact water management system is collected in the CWP. This   pond has been sized to contain the runoff volume (50,000 m3) associated with   the 24-hour, 200-year return period rain on snow event (the 24-hour, 200-year   rainfall has been estimated at 226 mm, while snowmelt potential has been   estimated at 43 mm). The contact water pond runoff is pumped to the mine WTP   for treatment prior to use in process or for discharge to Brucejack Lake. The   Brucejack Gold Mine process plant requires process water for the tailings   slurry to the lake, the underground paste backfill, the concentrate slurry,   and the underground mine supply. Process water is sourced from: Treated   underground seepage water  Treated   contact water from the CWP  Recovered   ore moisture  Water withdrawal from   Brucejack Lake at its outlet.  Average   annual groundwater seepage is sent to the WTP, and then the process plant,   where its use is maximized in process. The water management assessment   indicates that Brucejack Gold Mine surface and underground contact and   non-contact waters are being managed appropriately, and that water inputs,   including fresh water supplies, are adequate to support milling operations   and other mine requirements. 25-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 25.6.4 Water Balance The main   sources of water for ore processing at the Brucejack Gold Mine include water   that is conveyed by contact water ditches and surface sumps and reports to   the CWP, water that reports to sumps of the Underground Mine and is pumped to   surface, and permitted water withdrawals that are sourced from Brucejack   Creek adjacent the BJ 3.10 weir. Water that is withdrawn from CWP storage is   treated prior to being used in the mill. Surplus treated water may be   discharged to Brucejack Lake when mill water requirements are fully met or it   is necessary to manage pond volumes at a certain level. Operational water   data collected in 2018 and 2019 indicates releases of treated effluent to the   lake are necessary between May and October because the majority of annual   runoff is realized during these months and water surpluses are encountered at   the CWP. Water that reports to the Underground Mine is captured in sumps and   pumped to surface. Like water used from the CWP, sump water is treated prior   to being used in the mill or discharged to the lake when freshwater supply   exceeds mill water demand. A major component of underground sump water is   groundwater recharge that daylights in the mine due to dewatering activities.   In addition to groundwater recharge, water from the FW Tank in the mill   building is also directed below ground to support mining activities, such as   drilling and dust suppression. Water that is circulated to the underground   mine reports back to underground sumps and is pumped to surface for   treatment, then used in the mill or released to the lake. Mill water supply   that relies on either CWP storage or groundwater recharge is subject to   seasonal changes, and in the case of groundwater recharge, measured inflows   are lower than originally projected. However, Pretivm has demonstrated an   ability to operate at a 3,800 tpd production level while remaining within   permitted reclaim limits and within the constraints of the existing water   management system. A site-wide water balance model was constructed for the   Brucejack Gold Mine in Excel using a monthly time-step (BGC 2017a,b). The   major components of the Brucejack Mine water management system, including sump,   pumps, ponds, tanks, ditches, and treatment plants, are all encoded in the   water balance model. Furthermore, the model provides a robust accounting of   background and surface water flows from the headwaters of the Brucejack Lake   watershed, downstream to the BJ 1.74 monitoring location, which is below   Brucejack Lake. The site-wide water balance model is currently being updated   as part of the 5-Year Mine Plan and Reclamation Program Update pursuant to   permit requirements to consider several years of high-quality climate,   streamflow, and operational water data that have been collected at the mine   site since the water balance was developed. 25.6.5 Water Quality Key   mitigation measures to minimize Brucejack Gold Mine effects on water quality   include collection of underground mine waters and surface waters that contact   disturbed PAG rock and treatment of this collected water in the mine WTP, a   sewage treatment plant to treat domestic wastewater, and subaqueous   deposition of waste rock. Discharge of mine contact water to the aquatic   receiving environment is regulated under the conditions in Effluent Permit   107835 (PE-107835), most recently amended on December 14, 2018. Effluent   permits in British Columbia are issued pursuant to the provisions in British   Columbia’s Environmental Management Act for the protection of the   environment. Water quality monitoring results have shown that water has and   is continuing to be managed to meet the requirements of PE-107835, including   with respect to water quality limits for the mine effluent discharge.   Concentrations of metals and other parameters monitored at the outlet of   Brucejack Lake are below the current limits in PE-107835 and/or below BC WQGs   for the protection of aquatic life. The Brucejack Gold Mine water quality   model was updated in 2018 (Lorax 2018) and incorporated monitoring results   from construction and operation phases of the mine, as well as recent   geochemical test results. The updated model predicts that water quality will   continue to meet the discharge limits and other conditions set out in   PE-107835. 25-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 25.7 Capital Cost and   Operating Cost Estimates The total estimated LOM sustaining capital cost for   the Brucejack Gold Mine was estimated to be US$176.7 million, including   related costs for mining, processing, and site infrastructure and services. A   foreign exchange rate of Cdn$1.00:US$0.76 was used for the cost estimate. The   estimated LOM average operating cost for the Brucejack Gold Mine is   US$162.82/t milled. Table 25-1 shows the cost breakdown for each area. Table   25-1: LOM Average Operating Cost Summary (1) Including the costs for off-site   and satellite offices. Note: The operating costs exclude shipping charges and   sale costs for the gold-silver doré and gold-silver concentrate and   royalties, which are included in the financial analysis. All operating cost   estimates exclude taxes unless otherwise specified. 25.8 Economic Analysis   Tetra Tech prepared an economic evaluation of the Brucejack Gold Mine based   on a discounted cash flow model for the remaining 13 year LOM and 15.64 Mt of   ore included in the mine plan. For this mine plan, a post-tax NPV of US$1,496   million, at a discount rate of 5%, was calculated based on the following   assumptions: Gold price of US$1,300/oz    Silver price of US$16.90/oz    Foreign exchange rate of Cdn$1.00:US$0.76.  The production schedule was incorporated   into the pre-tax financial model to develop annual recovered metal   production. Capital expenditures include remaining capital expenditures for   mine throughput expansion to 3,800 t/d and ongoing sustaining capital costs   for mining and milling additions and equipment replacement. The NPV was estimated   at the beginning of the mining schedule and therefore has an effective date   of January 1, 2020. Table 25-2 summarizes the forecast for the economic   performance of the Brucejack Gold Mine operation for the remaining LOM. 25-9   Area Unit Operating Cost (US$/t milled) Mining 70.83 Processing 21.34 Overall   Site Services, including Office(1) 35.89 G&A 34.76 Total Operating Cost   162.82 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Table 25-2: Brucejack Gold   Mine Economic Performance Forecast The 2.5 years of operations that have been   completed at the Brucejack Gold Mine provides confidence in the project   economics, particularly with regard to understanding operating costs. The   Brucejack Gold Mine is most sensitive to metal prices, with opportunities to   improve profitability through cost management. 25.9 Project and Operation   Risks There are no known environmental liabilities or other significant risks   or factors that may affect access, title, or the ability or right to operate   the mine or perform work on the Brucejack Property, beyond the geopolitical,   economic, permitting, and legal climate that Pretivm operates in and   Pretivm’s ability to secure any required approvals, consents, and permits   under applicable legislation. 25-10 Unit Amount Tonnes Mined and Processed kt   15,637 Gold Head Grade g/t 8.4 Silver Head Grade g/t 59.6 Total Project   Revenue US$ million 5,266 Operating Costs US$ million (2,546) Royalties US$ million (63) Sustaining Capital Costs US$ million (177) Other Expenses US$ million (21) Taxes Payable US$ million (492) Post-tax NPV (5% Discount Rate)   US$ million 1,496 Post-tax NPV (8% Discount Rate) US$ million 1,293 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 26.1 Introduction This   Technical Report indicates that the Brucejack Gold Mine is considered to be   economically viable. The mine has a demonstrated capability of processing   3,800 t/d of ore, or higher. 26.2 Geology Faults, fractures, foliation   planes, and lithological contact structures are considered key features   controlling the distribution of electrum within the Brucejack Deposit. It is   therefore recommended that all occurrences of visible electrum in the   underground workings are calibrated to, and combined with drillhole data to   create a predictive tool to assist in delineating more detailed corridors of   higher-grade mineralization within the broader stockwork zones. This will   assist in improved local resolution of high-grade zones for resource   estimation. This should be completed as a part of the standard underground   geological mapping and other observations, and as such, does not need a   separate budget. Fluid mixing, utilizing various structural elements, appears   to have been the primary cause of colloidal suspension destabilization and   electrum precipitation. The presence of numerous phreatomagmatic breccia   bodies, immature volcaniclastic lithological units, and carbonate-dominated   veins, vein stockwork, and vein breccia, opens up the possibility of caldera   collapse and seawater ingress as being a trigger for ubiquitous fluid mixing.   It is recommended that a surface mapping campaign be conducted across the   Flow Dome Zone, eastern parts of the Valley of the Kings Zone, as well as to   the north and east of Brucejack Lake to test this possibility. Available   drillhole logs, core, and core photos should be reviewed to augment this   process. This should be completed as a part of the on-going exploration   process, and as such, it is not expected that this needs a separate budget.   The geology at depth, to the west, and to the east of the Valley of the Kings   Zone appears different to the part currently being mined: VSF   volcanosedimentary rocks become the primary host, being replaced by P1 latite   flows at depth and to the east; veins, vein breccia, and vein stockwork change   from quartz-carbonate to carbonate only veining (at least three generations   of calcite, including manganoan). Recent research has shown, through the use   of Transmission Electron Microscopy, that all of the electrum is hosted in   carbonate as opposed to quartz. The changing geology needs to be   characterized to assess the significance of these changes and to characterize   appropriate structural-lithological mineralization traps. Revisions to the   existing mine stratigraphy and mineralized vein classification scheme will be   required for these areas as drilling and mining expand into them. It is   understood that this work is being completed as a part of the on-going   near-mine exploration process, and as such, it is not expected that this   needs a separate budget to the existing near-mine exploration budget.   Additional drill exploration of the Bridge Zone should be reviewed in light   of the results of the 2019 geophysical programs. Additional near-mine   exploration, including targeted surface drilling and geophysics, is warranted   on the mineralized zones closest to the current mine to test the potential   for additional high-grade precious metal resources proximal to the mill. A   large gap in drill data exists between the Valley of the Kings and the West   Zone deposits. This area requires a systematic drilling approach to test for   mineralization. 26-1 26.0RECOMMENDATIONS 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 26.3 Mineral Resource   Reconciliation of the January 2020 resource model to the 2019 mill production   was within 10% on an annual production volume. Areas mined during this period   were generally informed by drilling on up to 15 m centers. It is therefore   recommended, going forward, that resource definition (infill) drilling be   conducted at 15 m centers or tighter. This should be budgeted within the mine   grade control process on an as-needed basis. All future drilling to be   conducted on the Valley of the Kings Zone and the West Zone should be as   close to perpendicular to the main mineralized trend as possible. This   includes drilling for exploration, resource definition drilling, and drilling   for grade control purposes. All efforts should be made to avoid drilling   parallel or close-to-parallel to the main mineralized trend. Although it is   impractical not to drill in fan patterns from underground drill bays, efforts   should be made to minimize excessive clustering at resource definition   drillhole collars in drill fans. Drilling parallel fans from spaced drill   bays versus multiple oriented fans from the same collar location is   recommended to minimize the clustering of samples at fan collars. Additional   infill drilling should be conducted in zones of interest, particularly the   Indicated Mineral Resource outside of the January 2020 update area to improve   the confidence in the estimates within the Resource model. A budget for this   will need to be determined on an as-needed basis, and as the requirements of   the mine change. An updated simulation-based drillhole spacing study is   recommended for the Valley of the Kings Zone considering the quantity of new   drilling and mining information that has been generated subsequent to the   previous study, conducted in 2016. Studies to-date using simulation show that   the simulations thus far have not been able to reproduce the entropy of the   mineralisation displayed in the drill data, and alternative strategies need   to be explored. No separate budget is required as the work should be   completed internally by Pretivm’s Resource Geology team. The current Mineral   Resource is, in practical terms, a bulk mining model. This is particularly   the case for that part of the Mineral Resource outside of the update area. In   order to improve model selectivity and enhance local estimation resolution,   in conjunction with infill drilling (which is critical for local mine   planning), alternative approaches to volume-variance adjustments are   recommended. In addition to the current re-blocking-based approach as part of   MIK post-processing, other techniques like generating re-blocked local   simulations should be tested. An updated simulation-based stope risk   assessment study is recommended once a suitable simulation strategy has been   defined. This will establish within-stope grade uncertainty to inform and   improve mine scheduling, as well as highlight areas that require additional   information. No separate budget is required as the work should be completed   internally by Pretivm’s Resource Geology team. Improved material tracking   techniques should be investigated to enhance annual reconciliation. It is   recommended that the mine source commercial software for the development of   tracking requirements. The cost of the software and its set-up should be   budgeted accordingly. More detailed information should be collected on the   individual performance of stopes from within the Measured Resource so that   confidence in the relevant grade estimates can be assessed. This is because,   even though the resource mined has good reconciliation, the local estimates   continue to show some variability with production, and Pretivm needs to   understand whether or not the local estimates are accurate enough to be   consistent with the requirements of a Measured Resource. Pretivm needs to   understand the confidence in these estimates for the future classification of   mineral resources. At the time of this report, there remain less than 1.5   million tonnes of Proven Reserve (i.e., derived from the Measured Resource).   26-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Near-mine Inferred Mineral Resources   in the eastern parts of the Valley of the Kings Zone represent a proximal   target for adding to the existing Measured + Indicated Mineral Resource base.   Additional infill drilling is recommended for the near term. The appeal of   this area is underlined by the results from the deep underground exploration   drilling conducted in 2018, which demonstrated the continuation of Valley of   the Kings Zone style mineralization towards the east and under the Flow Dome   Zone. It is expected that this would be included in the exploration and   near-mine exploration budgets as the company sees fit, and as such, it is not   expected that this needs an additional budget. In 2011, Pretivm produced a   Mineral Resource, in support of testing the open pit potential of other zones   at Brucejack, including Shore Zone, Bridge Zone and the Galena Hill Zone. As   open pit mining is currently not considered an option at Brucejack, that   Mineral Resource is no longer current. It is recommended that Pretivm revisit   these zones to examine the potential for estimating a Mineral Resource   suitable for underground extraction. No separate budget is required as the   work should be completed internally by Pretivm’s Resource Geologist. 26.4   Mining 26.4.1 Underground Mine Geotechnical SRK makes the following   recommendations for additional rock mechanics assessment work:  Further work should be completed on the   interpretation and modelling of large and intermediate scale faults. The   presence of unknown major structures or splays off known faults have the   potential to significantly affect rock mass stability (potential wedge   formation). Zones of sericiitc alteration are associated with geologic   structures, which also impact the rock mass. Defining and understanding the   spatial distribution of these features has the potential to optimize   development excavation ground support design and ore recovery. Reduction of   rock mass quality associated with major structures and strong alteration is   considered to be of particular risk to the recovery of secondary stopes. The   updated structural model should be reviewed to determine if updates to the   geotechnical assessments are required.    SRK recommends that the Brucejack Gold Mine review actual stope   performance and recovered volumes against planned stope volumes to identify   any potential stope performance patterns associated with specific   geotechnical domains, rock mass alteration, or geologic structures. Stope   dimensions and ground support can then be modified to optimize safe ore   recovery.  Now that the mine has been   operating for several years, valuable geotechnical and excavation performance   data is available for calibration of a numerical model. SRK recommends the   construction of a numerical model utilizing Map3D to assess rock mass   stability, potential impacts on major structural features (i.e., the   Brucejack, Rainy, and VOK faults), and areas of the mine in which elevated   stresses may develop as a result of the expansion of the mining footprint.   The estimated cost for the above-mentioned recommended work is $350,000. 26-3   

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 26.4.2 Mining Methods   Recommendations for Brucejack’s current mining method are centered around   optimisation of stope parameters and improving dilution and recovery. Control   and reduction of dilution to improve mining performance at Brucejack is   related to both geotechnical factors and mining methods. Stopes that are   planned in poorer-quality rock in areas bounded by mine-scale fault zones are   recommended to be assessed and designed on an individual basis, with the   following tasks undertaken: Alteration of stope dimensions, including   shortening of stope lengths, towards fault zones or areas of poorer rock   quality to improve stability  Continued   reconciliation of planned and recovered stope volumes to identify areas of   higher dilution  Spot assaying of   blasted muck to further track dilution and recovery estimates on an ongoing   basis  Blast control techniques   including drillhole surveys, blast damage monitoring, and blast design   modifications based on reconciliation of localised recovered stope volumes to   reduce any potential drill and blast-related dilution  In-situ strength testing of paste fill in   primary stopes to determine the quality of updated paste fill mixtures, which   were recommended from previous strength testing studies.  Increased operational experience will give   further confidence in the application of the Mine Call Factor combined with   monthly reconciliations to the short and long range mine plans. Further   definition of the capping parameters applied to the overall stope grade will   provide more continuity between the scheduled grades and reconciliation on a   monthly, quarterly, and annual basis. No separate budget is required for the   mining work as this can be completed internally by the Pretivm Engineering   and Geology teams. 26.4.3 Waste Rock Waste rock and tailings deposition is   governed by the OMS Manual, the last version having been updated in February   2020 (SRK 2020b). Specifically, waste rock dumping is done in accordance with   a standard operating procedure (Brucejack Lake Waste Rock Disposal, SOP 011),   which is an appendix to the OMS Manual. Pretivm’s engineering team manages   the day-to-day waste rock deposition and follow-up monitoring and   surveillance following procedures outlined in the OMS Manual. The OMS Manual   has been developed in accordance with SRK’s design recommendations and   undergoes updates as necessary. All employees working on the WRTSF are   provided training on the OMS Manual, specifically the WRTSF SOP. The required   surveillance procedures for waste rock and tailings deposition is explicitly   outlined in the OMS Manual, as are the QPOs. A daily report is produced by   the Pretivm on-site geotechnical engineers that outlines all activities   pertaining the waste rock dumping. This report is circulated internally to   Pretivm staff, including senior management, all off-shift geotechnical   personnel to ensure continuity, as well as to the EOR. If the EOR identifies   any anomalies or areas of concern based on the daily report, they reach out   to the on-site geotechnical engineers. It is recommended that Pretivm   continue to operate in accordance with these procedures outlined as it has   been demonstrated to ensure safe waste rock and tailings deposition   practices. 26-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 26.5 Mineral Processing and   Metallurgical Testing Further metallurgical tests are commended to optimize   metallurgical performances and support the operations. Installation of a   regrinding and gravity concentration circuit to recover fine gravity   recoverable gold and silver from the rougher flotation concentrate should be   investigated to further improve gold and silver recoveries to the doré. The   concentrate should be reground to release locked fine gold and silver grains.   However, a comprehensive technical and economic review should be conducted,   including investigating the effects of the additional gold and silver   recovery to doré on capital costs, operating costs, and gold and silver   payment of the flotation concentrate. Tailings and flotation concentrate   thickener performances should be further assessed for the increased mill feed   rate. The review work should include further flocculant type and dosage   evaluation and bypassing the coarse fraction of the final flotation tailings   to the tailings surge tank by cycloning to reduce the tailings thickener   loads. Also, the cyclone classification arrangement is expected to increase   solid density and improve particle size distribution of the paste plant feed,   which may save paste binder material consumption. Further optimization of   crushing and grinding circuits should be conducted in an effort to reduce   comminution circuit energy consumption and steel ball consumption, including   better utilizing the installed pebble crusher. The mill optimization is a   part of daily process operation improvements. The costs associated with these   optimizations have been included in the mill operating costs. 26.6   Environmental 26.6.1 Geochemistry The geochemistry of Brucejack Gold Mine   waste rock, ore, and tailings has been well characterized through baseline   studies and ongoing confirmatory sampling programs. The environmental   management plans in effect outline sampling recommendations, management   triggers, and corrective actions that are expected to minimize potential   adverse effects on water quality. It is recommended that, as planned,   confirmatory sampling and ongoing site monitoring data for waste rock, NPAG   quarry rock, tailings, paste backfill, and mine water continue to be   evaluated on an ongoing basis to identify potential environmental issues, to   improve understanding of site-specific geochemical behaviour, and to verify   the site-wide water quality model. Recommendations for future geochemical   studies at Brucejack Gold Mine include the following: Additional saturated   column tests on WTP sludge if the chemistry of mine water changes   significantly or if modifications are made to the water treatment   process  Additional kinetic tests on   tailings if changes are made to the milling process such that the chemistry   of the tailings changes significantly    Continued geochemical and mineralogical studies to predict mine water   quality during closure when the mine is flooded.  The estimated cost for this recommended   work is $300,000. 26-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 26.6.2 Hydrogeology The   numerical groundwater model is being updated to support water balance and   water quality modeling for the 2020 5-Year Mine Plan and Reclamation Program   update. The update will incorporate accurate as-built mine workings and   reflect a 3,800 t/d mine plan described in Jones et al. (2019). The 2020   groundwater model will be recalibrated to current underground dewatering   rates and groundwater level data to the end of 2018. Water level data records   from 2018 monitoring wells are limited for this data period. It is   recommended that the 2020 groundwater model be validated against 2019   dewatering rates and water levels as this data becomes available. Ongoing   collection of groundwater levels from all wells and pumping rate data from underground   per Environmental Management Act Permit PE-107835 and Mines Act Permit M-243   requirements will continue to be important for ongoing refinement of the   conceptual and numerical hydrogeologic models. 26.6.3 Water Management Water   management is a critical component of the Brucejack Gold Mine. Pretivm   employs a site-wide water management plan that includes monitoring procedures   for climate, streamflows, CWP levels, and flows being pumped around the mine   site or discharged to the environment. Monitoring data allows Pretivm to   optimize the operation in terms of water levels in the CWP, and discharges to   the environment. The basis to maintain the functionality of the water   management plan are the following: Existing climate and hydrometric stations   must continue to be monitored and maintained with an appropriate level of   quality control.  The following   levels/flows must continue to be monitored and maintained with an appropriate   level of quality control:  CWP levels   - CWP water pumped to the plant site - Effluent discharged from   the WTP to the CWP that does not meet the WTP water quality limits for   discharge to Brucejack Gold Lake - Fresh water pumped from the   low-level weir to the plant site - Water pumped from the fresh water   tank to underground - Underground water pumped to the WTP -   Treated effluent from the WTP discharged to Brucejack Lake - Routine   inspections as recommended in the OMS. - 26.6.4 Water Balance   Collection of baseline and operational water data affords Pretivm the opportunity   to assess and optimize the Brucejack Gold Mine water management system over   the LOM. Section 26.6.3 “Water Management” outlines baseline and operational   water monitoring activities that are core to the functionality of the   Brucejack Gold Mine water management system. These same data and activities   provide Pretivm with the information necessary to periodically update the   site-wide water balance model. The model is being revised in 2020 as part of   the 5-Year Mine Plan and Reclamation Program Update pursuant to permit requirements.   The last substantive update to the 26-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE BGC water balance model was   completed in autumn 2017 and several years of high-quality climate and   streamflow data have been collected at the mine site since that time. As part   of the planned water balance model update, it is recommended that operational   data for the underground mine, the CWP, the WTP, and Mill Circuit collected   since summer 2017 be thoroughly reviewed and the site-wide water balance   model updated with revised assumptions and data inputs, where appropriate.   Further, a proposed task under the update is to encode the site-wide water   balance model within a GoldSim environmental modelling framework rather than   using MS-Excel software. The Brucejack Gold Mine water quality model is   encoded in GoldSim and there are efficiencies to be gained by adopting a   common software platform for the water balance and water quality models.   26.6.5 Water Quality Water quality should continue to be monitored in   compliance with mine authorizations and environmental management plans to   verify that water is being managed to meet regulatory conditions for the   protection of the environment. The Brucejack water quality model provides   estimates of water quality through the operations, closure, and post-closure   phases of the Brucejack Gold Mine. This model will be updated in July 2020 as   part of the 5-Year Mine Plan and Reclamation Program Update. It is   recommended that, as planned, this update incorporate the latest water   quality monitoring data, geochemical test results, water balance, and mine   plan. 26-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 27.1 General Jones, I. W.O.,   Huang, J., Horan, M., Schmid, C., Carey, E., Ghaffari, H., Rykaart, M.,   Schmitt, R., Weatherly, H., Crozier, T., Shaw, A., 2019. Technical Report on   the Brucejack Gold Mine, Northwest British Columbia. NI 43-101 Technical   Report prepared for Pretium Resources Inc., by Ivor Jones Pty Ltd., Tetra   Tech Canada Inc., BGC Engineering Inc., Environmental Resources Management   (ERM), SRK Consulting (Canada) Inc., Lorax Environmental Services Ltd. 365   pp. Effective Date April 4, 2019. 27.2 Geology Alldrick, D.J., 1993. Geology   and metallogeny of the Stewart mining camp, northwestern British Columbia.   B.C. Ministry of Energy, Mines and Petroleum Resources, British Columbia   Geological Survey. Bulletin 85. 105 p. Armstrong, T., Brown, F., Puritch, E.,   and Vallat, C., 2011. Technical report and resource estimate on the Brucejack   Project, Skeena Mining Division, British Columbia, Canada, Latitude   5628'20"N by Longitude 13011'31"W. P+E Mining Consultants Inc. NI   43-101 Technical Report No. 229 for Pretium Resources Inc., Effective Date   November 28, 2011. 170 p. Board, W.S., 2015a. Geology update on the Brucejack   High Grade Au-Ag deposit Northwestern British Columbia, Canada. Pretium   Resources Inc. internal technical presentation. Vancouver, Canada. Board,   W.S., 2015b. Targeted exploration on the Brucejack Property: Recommendations   for the 2015 exploration program. Unpublished Pretium Memorandum Report dated   January 27, 2015. 65 p. Board, W.S., and McNaughton, K.C., 2013. The   Brucejack high-grade gold project, northwest British Columbia, Canada.   NewGenGold Conference, Perth, Australia, 2013, Proceedings, p. 177-191. West   Perth, Paydirt Pty Ltd. Board, W.S., McLeish, D.M., Greig, C.J., Bath, O.E.,   Ashburner, J.E., Murphy, T.M., and Friedman, R.M., Submitted. The Brucejack   Au-Ag Deposit, Northwest British Columbia, Canada: Multistage porphyry to   epithermal alteration, mineralization, and deposit formation in an island arc   setting. Submitted to Economic Geology, 45 p. Board, W.S., Mooney, C.R.,   Senger, N.D., and Jones, I.W.O., 2017. 2016 Valley of the Kings Mineral   Resource Update Summary Report, Brucejack Project, BC, Canada. Unpublished   summary report prepared for Pretivm under supervision by external QP Ivor   Jones, 5 June 2017, 137 p. Boyd, G., and Poon, J., 2015. Airborne 1TEM Survey   Report: Brucejack Project. Unpublished report prepared for Pretium Resources   Inc. by Precision GeoSurveys Inc. Dated December 2015. 74 p. Budinski D.,   McKnight R and Wallis C., 2001. Sulphurets-Bruceside Property British   Columbia technical report. Pincock Allen & Holt Ltd. report for Silver   Standard Resources. Campbell, M.E., and Dilles, J.H., 2017. Magmatic History   of the Kerr-Sulphurets-Mitchell Copper-gold Porphyry District, Northwestern   British Columbia (NTS 104B). Geoscience BC Summary of Activities 2016.   Geoscience BC. Report 2017-1. p. 233–244. Carvalho, D., and Deutsch, C. V.,   2017. An Overview of Multiple Indicator Kriging. In J. L. Deutsch   (Ed.),Geostatistics Lessons. Retrieved from   http://www.geostatisticslessons.com/lessons/mikoverview. CIM, 2014. CIM   Definition Standards. Prepared by the CIM Standing Committee on Reserve   Definitions: https://mrmr.cim.org/media/1088/cim_definition_standards_may10_2014.pdf,   Adopted by CIM Council May 10, 2014. 12 p. 27-1 27.0REFERENCES 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Corbett, G., 2013. Pacific   Rim Epithermal Au-Ag. Australasian Institute of Mining and Metallurgy: World   Gold Conference, Brisbane 26-27 September 2013, 14 p. Corona Corporation,   1990. Newhawk Gold Mines Ltd., Sulphurets Project, Feasibility Study, dated   October 1990. Davis, B., 2017. Foliation history and development of N-S   structures at Brucejack. Field visit observation report, prepared for Pretium   Resources Inc. by OREFIND. 32 p. Evenchick, C.A., 1991. Geometry, evolution,   and tectonic framework of the Skeena Fold Belt, north-central British   Columbia. Tectonics, v. 10. p. 527-546. Evenchick, C.A., McMechan, M.E.,   McNicoll, V.J., and Carr, S.D., 2007. A synthesis of the Jurassic-Cretaceous   tectonic evolution of the central and southeastern Canadian Cordillera:   Exploring links across the orogen, In: J.A. Sears, T.A. Harms, and C.A.   Evenchick (Eds.), Whence the Mountains?: Inquiries Into the Evolution of   Orogenic Systems: A Volume in Honor of Raymond A. Price, Special paper 433,   The Geological Society of America, Boulder, Colorado. 419 p. Farley, L.,   Olssen, L., and Jones, I., 2014. Brucejack Resource Estimate. Report Prepared   for Pretium Resources Inc. by Snowden Mining Industry Consultants Pty Ltd.   Project No. AU4015. March 2014. Effective date: December 19, 2013. 248p.   Febbo, G.E., Kennedy, L.A., Savell, M., Creaser, R.A., and Friedman, R.M.,   2015. Geology of the Mitchell Au-Cu-Ag-Mo porphyry deposit, northwestern   British Columbia, Canada: Geological Fieldwork 2014, British Columbia   Ministry of Energy and Mines, British Columbia Geological Survey. Paper   2015-1. p.59–86. Flasha, S.T., 2016. Diamond drilling report of the 2015   Brucejack Off Mining Leases Exploration Program, Brucejack Property, Mineral   Tenures 509397 & 1027399. Skeena Mining Division, British Columbia,   Canada, NTS 104B/9E. Geographic coordinates: 5627’26”N/13010’23”W; 427700E,   6257600N, NAD83 Zone 9. Event Number: 5605577. BC Geological Survey   Assessment Report No. 36214. Prepared for Pretium Resources Inc. Dated June   2, 2016. 1151 p. Flasha, S.T., 2017a. Diamond drilling report of the 2016   Bowser Property Exploration Program. BC Geological Survey Assessment Report   No. 36712. Prepared for Pretium Resources Inc. Dated January 27, 2017. 939 p.   Flasha, S.T., 2017b. 2016 Bowser Property Magnetometer and Radiometrics   Airborne Survey by Precision GeoSurveys Inc. BC Geological Survey Assessment   Report No. 36793. Prepared for Pretium Resources Inc. Dated March 21, 2017.   135 p. Flasha, S.T., 2017c. 2016 Bowser Property DCIP & MT Surveys by   Quantec Geoscience Ltd. BC Geological Survey Assessment Report No. 36790.   Prepared for Pretium Resources Inc. Dated April 4, 2017. 174 p. Gagnon,   J.-F., Barresi, T., Waldron, J.W.F., Nelson, J.L., Poulton, T.P., and Cordey,   F., 2012. Stratigraphy of the upper Hazelton Group and the Jurassic evolution   of the Stikine terrane, British Columbia. Canadian Journal of Earth Sciences,   v.49, p.1027-1052. Ghaffari, H., Huang, J., Narciso, H., Cameron, M.M.,   Cowie, S., Sweeney, D.J., Hollet, G.R., Brown, F., Armstrong, T., Boyle,   J.M., Wilchek, L-A., Newcomen, H.W., and Greisman, P., 2010a. Technical   Report and Preliminary Economic Assessment of the Snowfield-Brucejack   Project. Wardrop NI 43-101 Technical Report (No. 1053750400-REP-R0001-03) for   Silver Standard Resources Inc., Effective Date September 10, 2010, 376 p.   Ghaffari, H., Huang, J., Narciso, H., Cameron, M.M., Cowie, S., Sweeney,   D.J., Hollet, G.R., Brown, F., Armstrong, T., Boyle, J.M., Wilchek, L-A.,   Newcomen, H.W., and Greisman, P., 2010b. Technical Report and Preliminary   Economic Assessment of the Snowfield-Brucejack Project. Wardrop NI 43-101   Technical Report (No. 1053750400-REP-R0001-04) for Pretium Resources Inc.,   Effective Date October 28, 2010, 376 p. Ghaffari, H., Huang, J., Pelletier,   P., Armstrong, T., Brown, F., Newcomen, H.W., Wetherly, H., Logue, C., and   Mokos, P., 2011. Technical Report and Preliminary Economic Assessment of the   Brucejack Project. Wardrop NI 43-101 Technical Report for Pretium Resources   Inc., Effective Date June 3, 2011. 309 p. 27-2 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Glacken, I., and Blackney,   P., 1998. A Practitioners Implementation of Indicator Kriging. In: Beyond   Ordinary Kriging: Non-Linear Geostatistical Methods of Practice, Symposium   Proceedings. Geostatistical Association of Australasia. 30 October 1998.   Perth, Australia. p.26-39. Graindorge, J., and Carlson, R., 2014. QAQC   Review: Brucejack Project. Unpublished report prepared for Pretium Resources   Inc. by Snowden Mining Industry Consultants Pty Ltd. Project No. AU4015.   March 2014. 61p. Harrichhausen, N.J., Rowe, C.D., Board, W.S., and Greig,   C.J., 2016. Structural setting of a high-grade, electrum-bearing,   quartz-carbonate vein stockwork at the Brucejack deposit, northwestern   British Columbia (NTS 104B). Geoscience BC Summary of Activities 2015.   Geoscience BC. Report 2016-1. p. 127–138. Heinrich, C.A., Driesner, T.,   Stefánsson, A., and Seward, T.M., 2004. Magmatic vapor contraction and the   transport of gold from the porphyry environment to epithermal ore deposits.   Geological Society of America. v. 32. p. 761-764. Ireland, D., Jones, I.W.O.,   Huang, J., Pelletier, P., Weatherly, H., Stoyko, H.W., Hafez, S.A., Keogh,   C., Schmid, C., Cullen, V., McGuiness, M., McAfee, B., Chin, M., Gould, B.,   Wise, M., Greisman, P., Richards, C., Scott, W.E., Farah, A., Halisheff, K.,   Sriskandafumar, S., and Molavi, M., 2013. Feasibility Study and Technical   Report on the Brucejack Project, Stewart, BC. Tetra Tech NI 43-101 Technical   Report for Pretium Resources Inc. Effective Date June 21, 2013. 492 p.   Ireland, D., Olssen, L., Huang, J., Pelletier, P., Weatherly, H., Stoyko,   H.W., Hafez, S.A., Keogh, C., Schmid, C., McAfee, B., Chin, M., Gould, B.,   Wise, M., Greisman, P., Scott, W.E., Farah, A., Zazzi, G., Crozier, T., and   Blackmore, S., 2014. Feasibility Study and Technical Report Update on the   Brucejack Project, Stewart, BC. Tetra Tech NI 43-101 Technical Report for   Pretium Resources Inc. Effective Date June 19, 2014. 460 p. Jones, I.W.O.,   2012a. Pretium Resources Inc: Brucejack Project, Mineral Resources Update   Technical Report. NI 43-101 Technical Report prepared by Snowden Mining   Industry Consultants on behalf of Pretium Resources Inc. Effective Date April   3, 2012. 143 p. Jones, I.W.O., 2012b. Pretium Resources Inc: Brucejack   Project, Mineral Resources Update Technical Report. NI 43-101 Technical   Report prepared by Snowden Mining Industry Consultants on behalf of Pretium   Resources Inc. Effective Date September 18, 2012. 118 p. Jones, I.W.O.,   2012c. Pretium Resources Inc.: Brucejack Project, Mineral Resources Update   Technical Report. NI 43-101 Technical Report prepared by Snowden Mining   Industry Consultants on behalf of Pretium Resources Inc. Effective Date   November 20, 2012. 106 p. Jones, I.W.O., 2014. Pretium Resources Inc:   Brucejack Project, Mineral Resources Update Technical Report. NI 43-101   technical report prepared by Snowden Mining Industry Consultants on behalf of   Pretium Resources Inc. Effective Date December 19, 2013. 194 p. Kirkham, R.V.   and Margolis, J., 1995. Overview of the Sulphurets area, northwestern British   Columbia, in: .Porphyry Deposits of the Northwestern Cordillera of North   America. CIMM Special Volume 46, T.G. Schroeter, ed., p.473–482. Kyba, J.,   2014. The Stuhini-Hazelton unconformity of Stikinia, Investigations at   KSM-Brucejack, Snip-Johnny Mountain, and Red Chris areas. Conference abstract   presented in T27. Triassic-Jurassic Tectonics and Tectonic-Structural   Controls on Porphyry and Related Mineralization in the Northern Cordillera.   https://gsa.confex.com/gsa/2014AM/webprogram/Paper248935.html. Geological   Society of America Annual Meeting 2014. Vancouver, BC, Canada. Leary, S.,   Sillitoe, R.H., Stewart, P.W., Roa, K.J., and Nicolson, B.E., 2016.   Discovery, geology, and origin of the Fruta del Norte epithermal gold-silver   deposit, southeastern Ecuador. Economic Geology, v.111, p.1043-1072.   Macdonald, A.J., 1993. Lithostratigraphy and geochronometry, Brucejack Lake,   northwestern British Columbia (104B/08E). Geological Fieldwork 1992, British   Columbia Ministry of Energy and Mines, British Columbia Geological Survey.   Paper 1993-1. p. 315-323. 27-3 

    

 

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Margolis, J., 1993. Geology   and intrusion-related copper-gold mineralization, Sulphurets, British   Columbia. Unpublished Ph.D. Dissertation. University of Oregon. 394 p.   McLeish, D.F., Williams-Jones, A.E., Board, W.S., and Clark, J.R., 2018.   Nature and origin of the Brucejack high-grade epithermal gold deposit,   northwestern British Columbia (NTS 104B) 2017 update. Geoscience BC Summary of   Activities 2017. Minerals and Mining. Geoscience BC Report 2018-1. p. 31–40.   McLeish, D.F., Williams-Jones, A.E., Board, W.S., Stern, R.A., Clark, J.R.,   and Vasyukova, O.V., 2019. The formation and origin of ultra-high grade gold   ore at the Brucejack Deposit, Northwest British Columbia: Insights from   nanoscale imaging of electrum and high-resolution trace element and sulphur   isotope analyses of pyrite. Poster session presented at AME Roundup (January   28, 2019), Vancouver, BC. McPherson, M., 1994. 1994 assessment report on the   North Bruce Group, Sulphurets Property – Bruceside Project, Newhawk Gold   Mines Ltd. British Columbia Ministry of Energy, Mines and Petroleum   Resources, Geological Branch Assessment Report 23613, 64 p. Monger, J.W.H.,   and Price, R., 2002. The Canadian Cordillera; geology and tectonic evolution.   Canadian Society of Exploration Geophysicists Recorder. v. 27. p. 17-36.   Mooney, C., 2015. Brucejack Gold Deposit: 2014 and 2015 Drilling QAQC Review.   Pretium Resources Inc. internal report. Dated November 27, 2015. 28p.   Narciso, N., Huang, J., Iakovlev, I., Cameron, M., Bosworth, G., Brown, F.,   Armstrong, T., Boyle, M., Wilchek, L-A, Newcomen, W., and Pelletier, P.,   2010. Technical Report and Preliminary Assessment on The Snowfield Property.   Wardrop NI 43-101 Technical Report for Silver Standard Resources Inc.   Effective Date June 1, 2010. 281 p. Nelson, J., and Colpron, M., 2007.   Tectonics and metallogeny of the British Columbia, Yukon and Alaskan   Cordillera, 1.8 Ga to the present. In: Goodfellow, W.D., ed. Mineral Deposits   of Canada: A Synthesis of Major Deposit-Types, District Metallogeny, the   Evolution of Geological Provinces, and Exploration Methods. Geological   Association of Canada, Mineral Deposits Division, Special Publication No. 5,   p. 755-791. Nelson, J., and Kyba, J., 2014. Structural and stratigraphic   control of porphyry and related mineralization in the Treaty Glacier – KSM –   Brucejack – Stewart trend of western Stikinia. Geological Fieldwork   2013.British Columbia Ministry of Energy and Mines. British Columbia   Geological Survey. Paper 2014-1. p. 111-140. Nelson, J., Colpron, M., and   Israel, S., 2013. The Cordillera of British Columbia, Yukon, and Alaska:   Tectonics and Metallogeny. In: Colpron, M., Bissig, T., Rusk, B.G., and   Thompson, J.F.H., eds. Tectonics, Metallogeny and Discovery: The North   American Cordillera and Similar Accretionary Settings. Society of Economic   Geologists, Special Publication No. 17, p.53-109. Payie, G.J., 2017. British   Columbia Geological Survey MINFILE report no. 104B 193 on the Brucejack area:   http://minfile.gov.bc.ca/Summary.aspx?minfilno=104B++193. Pezzot, E.T., 2015.   Brucejack Project Airborne Magnetometer and Radiometric Survey. Unpublished   Geophysical Interpretation Report prepared for Pretium Resources Inc by Precision   GeoSurveys Inc. January 2015. 51 p. Poon, J., 2015. Brucejack Project   Airborne Magnetic and Radiometric Survey. Unpublished Airborne Geophysical   Survey Report prepared for Pretium Resources Inc. by Precision GeoSurveys   Inc. Dated December 2015. 81 p. Pretivm, 2016b. Positive Valley of the Kings   Mineral Reserve Update; Senior Management Changes. Pretivm press release   dated 12/15/2016:   https://www.pretivm.com/news/news-details/2016/Pretium-Resources-Inc-Positive-Valley-of-the-Kings-Mineral-Reserve-Update-Senior-Management-Changes/default.aspx.   Richards, J.P., and Kerrich, R., 1993. The Porgera Gold Mine, Papua New   Guinea: Magmatic Hydrothermal to Epithermal Evolution of an Alkalic-type   Precious Metal Deposit. Economic Geology, v.88, p.1017-1052. 27-4 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Roach, S., and Macdonald,   A.J., 1992, Silver-gold vein mineralization, West Zone, Brucejack Lake,   northwestern British Columbia (104B/8E). British Columbia Geological Survey.   Geological Fieldwork 1991. Paper 1992-1. p. 503-511. Ronacher, E., Richards,   J.P., Reed, M.H., Nray, C.J., Spooner, E.T.C., and Adams, P.D., 2004.   Characteristics and Evolution of the Hydrothermal Fluid in the North Zone   High-Grade Area, Porgera Gold Deposit, Papua New Guinea. Economic Geology,   v.99, p.843-867. Schroeter, T. G., 1994. British Columbia mining,   exploration, and development 1993 highlights: British Columbia Mineral   Exploration Review 1993. British Columbia Geological Survey Information   Circular 1994-1, 27 p. Sherman, D., and Candy, C., 2019, Geophysical   Exploration Program; Bell II Area. Prepared for Pretium Resources Inc. by   Frontier Geosciences Inc. Dated December 13, 2019. 22 p. Sillitoe, R.H.,   2015. Comments on geology and exploration potential of the Brucejack   Gold-Silver Deposit and environs, British Columbia, Canada. Unpublished   report prepared for Pretium Resources Inc. 16 p. Sillitoe, R.H., and   Hedenquist, J.W., 2003. Linkages between volcanotectonic settings, ore fluid   compositions, and epithermal precious metal deposits. Society of Economic   Geologists Special Publication 10, p. 315–343. Stephen., J., Personal   communication. Quantec Geoscience. Dated November 5, 2019. Sykora, S., Cooke,   D.R., Meffre, S., Stephanov, A.S., Gardner, K., Scott, R., Selley, D., and   Harris, A.C., 2018. Evolution of pyrite trace element compositions from   porphyry style and epithermal conditions at the Lihir gold deposit:   Implications for ore genesis and mineral processing. Economic Geology. v.   113. p. 193-208. Tombe, S.P., 2015. Age and origin of the Brucejack   epithermal Au-Ag deposit, northwestern British Columbia. Unpublished M.Sc.   thesis. Edmonton. University of Alberta. 201 p. Tombe, S.P., Richards, J.P.,   Greig, C.J., Board, W.S., Creaser, R.A., Muehlenbachs, K.A., Larson, P.B.,   DuFrane, S.A., and Spell, T., 2018. Origin of the high-grade Early Jurassic   Brucejack epithermal Au-Ag deposits, Sulphurets Mining Camp, northwestern   British Columbia. Ore Geology Reviews, v.95, p.480-517. Tuncer, V., 2014a.   Spartan Magnetotelluric Survey Geophysical Report: Snowfield and Brucejack   Projects, British Columbia, Canada. Unpublished report prepared for Pretium   Resources Inc. by Quantec Geoscience Ltd. Dated December 12, 2014. 345 p.   Tuncer, V., 2014b. Spartan Magnetotelluric Survey Geophysical Report –   Addendum (Topography included 3D Inversion): Snowfield and Brucejack   Projects, British Columbia, Canada. Unpublished report prepared for Pretium   Resources Inc. by Quantec Geoscience Ltd. Dated December 12, 2014. 182 p.   Turkoglu, E., Young, C., and Gregory, W., 2011. Spartan Magnetotelluric   Survey Geophysical Report: Snowfield & Brucejack Project, British   Columbia, Canada. Unpublished report prepared for Pretium Resources Inc. by   Quantec Geoscience Ltd. Dated December 14, 2011. 223 p. Vallat, C., 2009.   Quality Assurance and Quality Control Report on Brucejack pre-Silver Standard   Resources Inc. Analytical Results, Brucejack Project, Skeena Mining Division,   British Columbia, Canada. Unpublished report prepared for Silver Standard   Resources Inc. by GeoSpark Consulting Inc. Dated October 7, 2009. 142 p.   Vallat, C., 2011. Quality Assurance and Quality Control Report on Brucejack   2011 Analytical Results, Brucejack Project, Skeena Mining Division, British   Columbia, Canada. Unpublished report prepared for Pretium Resources Inc. by   GeoSpark Consulting Inc. Dated December 22, 2011. 53 p. Vallat, C., 2012.   Quality Assurance and Quality Control Report on Brucejack 2012 Analytical Results,   Brucejack Project, Skeena Mining Division, British Columbia, Canada.   Unpublished report prepared for Pretium Resources Inc. by GeoSpark Consulting   Inc. Dated September 13, 2012. 39 p. Vallat, C., 2013. Quality Assurance and   Quality Control Report on Brucejack 2012 Analytical Results, Brucejack   Project, Skeena Mining Division, British Columbia, Canada. Unpublished report   prepared for Pretium Resources Inc. by GeoSpark Consulting Inc. Dated January   4, 2013. 60 p. 27-5 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Vallat, C., 2014. Quality   Assurance and Quality Control Report on Brucejack 2013 Analytical Results,   Brucejack Project, Skeena Mining Division, British Columbia, Canada.   Unpublished report prepared for Pretium Resources Inc. by GeoSpark Consulting   Inc. Dated April 9, 2014. 74 p. Vallat, C., 2015. Quality Assurance and   Quality Control Report on Brucejack 2014 Analytical Results, Brucejack   Project, Skeena Mining Division, British Columbia, Canada. Unpublished report   prepared for Pretium Resources Inc. by GeoSpark Consulting Inc. January 21,   2015. 60 p. Vallat, C., 2016a. Quality Assurance and Quality Control Report   on Brucejack 2015 Analytical Results, Brucejack Project, Skeena Mining   Division, British Columbia, Canada. Unpublished report prepared for Pretium   Resources Inc. by GeoSpark Consulting Inc. Dated March 24, 2016. 72 p.   Vallat, C., 2016b. Quality Assurance and Quality Control Report on Brucejack   2016 Analytical Results, Brucejack Project, Skeena Mining Division, British   Columbia, Canada. Unpublished report prepared for Pretium Resources Inc. by   GeoSpark Consulting Inc. August 12, 2016. 41 p. Vallat, C., 2018. Quality   Assurance and Quality Control Report on Brucejack 2017 and 2018 Analytical   Results: Brucejack Project, Skeena Mining Division, British Columbia, Canada.   Unpublished report prepared for Pretivm Resources Inc. by GeoSpark Consulting   Inc. Dated September 21, 2018. 77 p. Vallat, C., 2019. Quality Assurance and   Quality Control Report on Brucejack 2018 Analytical Results: Brucejack   Project, Skeena Mining Division, British Columbia, Canada. Unpublished draft   report prepared for Pretivm Resources Inc. by GeoSpark Consulting Inc. Dated   February 15, 2019. 67 p. Wafforn, S.R., 2018a. Geological, Geochemical and   Prospecting Program on the Bowser Property. BC Geological Survey Assessment   Report No. 37435. Prepared for Pretium Resources Inc. Dated February 1, 2018.   514 p. Wafforn, S.R., 2018b. Geological, Geochemical and Prospecting Program   on the Bowser Property. BC Geological Survey Assessment Report No. 37443.   Prepared for Pretium Resources Inc. Dated February 5, 2018. 1238 p. 27.3   Metallurgy and Recovery Methods ALS Metallurgy-Kamloops, 2018. Metallurgical   Testing for the Brucejack Project. June 18, 2018. Bureau Veritas Commodities   Canada Ltd. BC Minerals – Metallurgical Division, 2017. Mineralogical   Assessment of Two Concentrate Samples. August 31, 2017. Bureau Veritas   Commodities Canada Ltd. BC Minerals – Metallurgical Division, 2016.   Metallurgical Testing for Concentrate Production. March 3, 2016. Clay   Speciation Analysis of Samples, 2019, Process Mineralogical Consulting Ltd.,   March 22, 2019. Cominco Engineering Services Ltd., 1990. Feasibility Study   Sulphurets Property Newhawk Gold Mines Ltd. March 1990. Contract Support   Services, Inc., 2012. JK Simulation Results for Brucejack Project. November   29, 2012. Daily Mill Reports, 2018 to 2019, Brucejack Mine, Pretivm Resources   Inc. Diagnostic Leach Report, 2019, B V Minerals, Bureau Veritas Commodities   Canada Ltd. November 18, 2019. Dawson Metallurgical Laboratories, FLSmidth   Ltd., 2014. Letter Report - Brucejack Tabling and Smelting. May 29, 2014. F.   Wright Consulting Inc., 2013. Gravity/Flotation Response - Valley of the   Kings, Brucejack Project. May 7, 2013. F. Wright Consulting Inc., 2013.   Metallurgical Data - Brucejack Gold Silver Project. February 08, 2013. F.   Wright Consulting Inc., 2014. Low Grade Response - Valley of the Kings,   Brucejack Project. June 10, 2014. FLSmidth Knelson, A Division of FLSmidth   Ltd., 2012a. Gravity Modeling Report. July 11, 2012. 27-6 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE FLSmidth Knelson, A Division   of FLSmidth Ltd., 2012b. Gravity Test Work Report. August 9, 2012. FLSmidth   Ltd., 2018. Gravity Circuit Modeling Report. April 20, 2018. Gekko   Metallurgical Laboratory, 2017. Intensive Cyanidation of Knelson Concentrate Testwork   Report. August 31, 2017. Gekko Systems Pty Ltd., 2014. Brucejack Python Study   Update. May 06, 2014. Gekko Systems Pty Ltd., 2014. Metallurgical Testwork   Reports (Low Grade, Medium and High Grade Samples). April 28, 2014. Gold   Recovery from Brucejack Concentrate, 2019, XPS, A GLENCORE Company, October   31, 2019. Hazen Research Inc., 2012. Comminution Testing with SMC Results.   July 13, 2012. Head Assay Report, 2019, B V Minerals, Bureau Veritas   Commodities Canada Ltd. November 18, 2019. Joe Zhou Mineralogy Ltd., 2012.   Deportment Study of Gold and Silver in Cyanide Leach Residues from Brucejack   Lake Project, Part I, Part II and Part III. February 20, 2012. Metallurgical   Division at Inspectorate America Corp., December 2009 to July 2010. Data   Reports. Metallurgical Division at Inspectorate America Corp., September 2010   to April 2011. Data Reports. Metallurgical Division at Inspectorate   Exploration and Mining Services Ltd., 2014. Mineralogical Assessments on the   Process Stream Samples. May 15, 2014. Met-Solve Laboratories Inc., 2012.   Gravity Test Report - MS1399. July 10, 2012. Met-Solve Laboratories Inc.,   2013. Gravity Circuit Modeling - MS1418. March 14, 2013. Met-Solve   Laboratories Inc., 2014b. Letter Report - MS1542. June 2, 2014. Met-Solve   Laboratories Inc.,2014a. Letter Report - MS1542. May 21, 2014. Pocock   Industrial Inc., 2019. Solids-Liquid Separation Testing Report. January 2019.   Pocock Industrial, Inc., 2012. Sample Characterization, Particle Size   Analysis, Flocculant Screening, Gravity Sedimentation, Pulp Rheology/Paste   Vacuum Filtration and Pressure Filtration Studies. November 2012. Process   Mineralogical Consulting Ltd., 2012. A Mineralogical Description of Six   Samples from the Brucejack Project, Northwestern British Columbia. June 1,   2012. Process Mineralogical Consulting Ltd., 2018. A Mineralogical   Description and Gold Deportment Analysis of One Concentrate Sample. October   1, 2018. SNF Canada, 2016. Polymer cylinder Test Report. November 18, 2016.   SNF Canada, 2017a. Site Service Visit Report. October 19, 2017. SNF Canada,   2017b. Tailings Thickener Polymer Treatment Review. December 20, 2017.   Solids-Liquid Separation Testing Report, 2019, Pocock Industrial, Inc.,   January 2019. 27.4 Mining AMC Mining Consultants (Canada) Ltd., 2015.   Brucejack Underground Feasibility Study Update; Backfill Design and Test Work   Report. May 5, 2015. AMC Mining Consultants (Canada) Ltd., 2018. Brucejack   Backfill Management Plan. October 8, 2018. Ghaffari, H., Huang, J, Pelletier,   P., Armstrong, T., Brown, F.H., Newcomen, H.W., Weatherly, H., Logue, C.,   Mokos, P., 2011: Technical Report and Preliminary Economic Assessment of the   Brucejack Project. NI43-101 Technical Report prepared for Pretium Resources   Inc., by Tetra Tech, Wardrop, P&E Mining Consultants Inc., BGC Engineering   Inc., Rescan Environmental Services Ltd., AMC Mining Consultants (Canada)   Ltd. 309 pp. Effective Date 3 Jun 2011. 27-7 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Ghaffari, H., Huang, J.,   Hafez, S. A., Pelletier, P., Armstrong, T., Brown, F.H., Vallat, C.J.,   Newcomen, H.W., Weatherly, H., Wilchek, L., Mokos, P., 2012: Technical Report   and Updated Preliminary Economic Assessment of the Brucejack Project.   NI43-101 Technical Report prepared for Pretium Resources Inc., by Tetra Tech,   Wardrop, Rescan Environmental Services Ltd., P&E Mining Consultants Inc.,   Geospark Consulting Inc., BGC Engineering Inc., AMC Mining Consultants   (Canada) Ltd. 328pp. Effective Date 20 Feb 2012. Ireland, D., Olssen, L.,   Huang, J., Pelletier, P., Weatherly, H., Stoyko, H.W., Hafez, S.A., Keogh,   C., Schmid, C., McAfee, B., Chin, M., Gould, B., Wise, M., Greisman, P.,   Scott, W.E., Farah, A., Zazzi, G., Crozier, T., and Blackmore, S., 2014.   Feasibility Study and Technical Report Update on the Brucejack Project,   Stewart, BC. Tetra Tech NI 43-101 Technical Report for Pretium Resources Inc.   Effective Date June 19, 2014. 460 p. Jones, I. W.O., Huang, J., Horan, M.,   Schmid, C., Carey, E., Ghaffari, H., Rykaart, M., Schmitt, R., Weatherly, H.,   Crozier, T., Shaw, A., 2019. Technical Report on the Brucejack Gold Mine,   Northwest British Columbia. NI 43-101 Technical Report prepared for Pretium   Resources Inc., by Ivor Jones Pty Ltd., Tetra Tech Canada Inc., BGC   Engineering Inc., Environmental Resources Management (ERM), SRK Consulting   (Canada) Inc., Lorax Environmental Services Ltd. 365 pp. Effective Date April   4, 2019. 27.5 Mining Geotechnical Bieniawski, Z.T., 1976. Rock mass   classification in rock engineering. In Exploration for rock engineering,   proc. of the symp., (ed. Z.T. Bieniawski) 1, 97-106. Cape Town: Balkema.   Clark, L.M., 1998. Minimizing Dilution in Open Stope Mining with a Focus on   Stope Design and Narrow Vein Longhole Blasting. MSc thesis, University   British Columbia, Canada. ERSi (Earth Resource Surveys Inc.), 2010. KSM   Project Area Structural Geology Assessment – Draft. Grimstad, E. and Barton,   N., 1993. Updating of the Q-system for NMT. Proceedings of the International   Symposium on Sprayed Concrete. Modern Use of Wet Mix Sprayed Concrete for   Underground Support, Fagemes. Norwegian Concrete Association, Oslo.   International Society of Rock Mechanics (ISRM), 1985. Suggested Method for   Determining Point Load Strength. Ireland, D., Jones, I.W.O., Huang, J.,   Pelletier, P., Weatherly, H., Stoyko, H.W., Hafez, S.A., Keogh, C., Schmid,   C., Cullen, V., McGuiness, M., McAfee, B., Chin, M., Gould, B., Wise, M.,   Greisman, P., Richards, C., Scott, W.E., Farah, A., Halisheff, K.,   Sriskandafumar, S., and Molavi, M., 2013. Feasibility Study and Technical   Report on the Brucejack Project, Stewart, BC. Tetra Tech NI 43-101 Technical   Report for Pretium Resources. Effective Date June 21, 2013. 492 pp. Ireland,   D., Olssen, L., Huang, J., Pelletier, P., Weatherly, H., Stoyko, H.W., Hafez,   S.A., Keogh, C., Schmid, C., McAfee, B., Chin, M., Gould, B., Wise, M.,   Greisman, P., Scott, W.E., Farah, A., Zazzi, G., Crozier, T., and Blackmore,   S., 2014. Feasibility Study and Technical Report Update on the Brucejack   Project, Stewart, BC. Tetra Tech NI 43-101 Technical Report for Pretium   Resources Inc. Effective Date June 19, 2014. 460 p. Mawdesley, C., Trueman, R.,   Whiten, W., 2001. Extending the Mathews Stability Graph for Open Stope   Design. Trans. IMM (Section A). Volume 110, p. A27–39. Ouchi, A., Pakalnis,   R., Brady, E., 2004. Update of Span Design Curve for Weak Rock Masses. Proc.   of the 99th Annual AGM-CIM Conference. Rocscience Inc., 2003. Unwedge Version   3.0 – Underground Wedge Stability Analysis. https://www.rocscience.com,   Toronto, Ontario, Canada. Stewart, S. B.V., Forsyth, W.W., 1995. The Matthews   Method for Open Stope Design. CIM Bull., 88, No. 992, p. 45–53. 27-8 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE 27.6 Waste Rock Disposal   British Columbia Mine Waste Rock Pile Research Committee (BCMWRP), 1991.   Mined Rock and Overburden Piles Investigation and Design Manual. Interim   Guidelines. May. Peck, R. B., 1969. Advantages and limitations of the   observational method in applied soil mechanics. Geotechnique 19.2: 171–187.   SRK Consulting (Canada) Inc., 2014. Brucejack Gold Mine Project – Waste Rock   Stability and Settlement Analysis – UPDATED. Technical memo prepared for   Pretium Resources Inc. December 23. SRK Consulting (Canada) Inc., 2015.   Brucejack Gold Mine Project – Waste Rock and Tailings Data Review – UPDATED.   Technical memo prepared for Pretium Resources Inc. January 8. SRK Consulting   (Canada) Inc., 2016. Tailings and Waste Rock Subaqueous Deposition Management   Plan Design Report, Brucejack Project, British Columbia. Report prepared for   Pretium Resources Inc. February. SRK Consulting (Canada) Inc., 2018.   Brucejack Gold Mine: Updated Subaqueous Waste Rock Dump Design. Report   prepared for Pretium Resources Inc., October. SRK Consulting (Canada) Inc.,   2020. Operation, Maintenance and Surveillance Manual: Brucejack Gold Mine   Subaqueous Waste Rock and Tailings Deposition. Version 7. Report prepared for   Pretium Resources Inc., March. Terzaghi, K. and Peck, R. B., 1967. Soil   Mechanics in Engineering Practice. 566–566. 27.7 Avalanche Hazard Assessment   Gould, B. and Campbell, C, 2019. Remote Avalanche Control Systems (RACS) –   Field Visit Summary and Updated Layout for the KM59 Glacier Access Route and   Sluicebox Avalanche Area. Memorandum by Alpine Solutions, February 28, 2019.   Ireland, D., Olssen, L., Huang, J., Pelletier, P., Weatherly, H., Stoyko,   H.W., Hafez, S.A., Keogh, C., Schmid, C., McAfee, B., Chin, M., Gould, B.,   Wise, M., Greisman, P., Scott, W.E., Farah, A., Zazzi, G., Crozier, T., and   Blackmore, S., 2014. Feasibility Study and Technical Report Update on the Brucejack   Project, Stewart, BC. Tetra Tech NI 43-101 Technical Report for Pretium   Resources Inc. Effective Date June 19, 2014. 460 p. 27.8 Environmental   2006.pdf (accessed December 2014). 2006/dp-pd/prof/92-594/Index.cfm?Lang=E   (accessed February 2014). BC ILMB, 2000. Cassiar Iskut-Stikine Land and   Resource Management Plan, prepared by the BC Integrated Land Management   Bureau, 2009. BC MFLNRO, 1995. Forest Practices Code Biodiversity Guidebook.   BC MFLNRO, 2012. Nass South Sustainable Resource Management Plan. BC MEMPR,   Mines Act permit M-243, Permit Approving Mine Plan and Reclamation Program.   BC Ministry of Environment and BC Ministry of Energy and Mines, 2015.   Environmental Assessment Certificate #M15-01 – Brucejack Gold Mine. BC Bill   41. BC Declaration on the Rights of Indigenous Peoples Act. Business   Corporations Act, SBC., 2002a. C. 57. Canada Impact Assessment Act, S.C.   2019, c. 28, s.1. 27-9 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Canada Environmental   Assessment Act, S.C., 2012. c. 19. s. 52. Concurrent Approval Regulation, BC   Reg. 371/2002. Environmental Assessment Act, SBC, 2002b. C. 43. – 2002.   Environmental Assessment Act [SBC 2018] c. 51, s. 81 – 2019. Environmental   Impact Assessment. Prepared for Pretium Resources Inc. by ERM Consultants   Environmental Management Act, SBC., 2003. C. 53. ERM Rescan, 2014. Brucejack   Gold Mine Project: Application for an Environmental Assessment Certificate.   Forest Act, RSBC., 1996a. C. 157. Forest Practices Code of British Columbia   Act [RSBC 1996] C. 159. Health Act, RSBC., 1996b. C. 179.   http://www.for.gov.bc.ca/tasb/slrp/lrmp/smithers/cassiar/plan/files/CIS-LRMP-November-http://www.ilmb.gov.bc.ca/slrp/srmp/south/nass/index.html   (accessed September 2009).   http://www.ilmb.gov.bc.ca/slrp/srmp/south/nass/index.html (accessed November   2012). Land Act, RSBC., 1996c. C. 245. Mines Act, RSBC., 1996d. C. 293.   Regulations Designating Physical Activities, SOR/2012-147. Reviewable Project   Regulation, BC Reg. 370/2002.   http://www12.statcan.gc.ca/censusrecensement/Water Act Statistics Canada,   2007. 2006 Aboriginal Population Profile.   http://www12.statcan.gc.ca/censusrecensement/Water Act, RSBC., 1996e. C. 483.   Statistics Canada, 2016 Census of Canada. 27.9 Water Management BGC   Engineering Inc. and Pretium Resources Inc., 2018. Brucejack Gold Mine –   Operation, Maintenance & Surveillance Manual. Water Management Plan.   Version 004, December 15, 2018. BGC Engineering Inc., 2017. Water Balance   Model 3800 tpd Permit Amendment Applications [Report]. Prepared for Pretium   Resources Inc. Doc. No. BJ-2017-57, December 13, 2017. 27.10 Water Balance   BGC Engineering Inc., 2017a. Brucejack WBM, 3800 tpd, Operations MS-Excel   Water Balance Model. Prepared for Pretium Resources Inc., October 2, 2017.   BGC Engineering Inc., 2017b. Water Balance Model 3800 tpd Permit Amendment   Applications [Report]. Prepared for Pretium Resources Inc. Doc. No.   BJ-2017-57, December 13, 2017. 27.11 Water Quality ERM Rescan, 2014.   Brucejack Gold Mine Project: Cumulative Water Quality Baseline Report.   Prepared for Pretivm Resources Inc. by ERM Consultants Canada Ltd. Vancouver,   BC. January 2014. Lorax Environmental Services Ltd. (Lorax), 2018. Brucejack   Gold Mine: 2018 Water Quality Model Report in Support of Amendment   Applications for Ore Production Increase to 3800 tpd. Prepared by Lorax   Environmental Services Ltd. for Pretium Resources Ltd. April 11, 2018. 27-10 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Pretium Resources Inc.   (Pretivm), 2015. Applications for Mines Act and Environmental Management Act   Permits. Submitted May 2015. Pretivm Resources Inc. (Pretivm), 2018b. 3800 tpd   Amendment Application for Permits M-243 and PE-107835. April 2018. 27.12   Geochemistry BGC Engineering Inc., 2014b. Brucejack Environmental Assessment   – ML/ARD Baseline Report. Prepared for Pretivm Resources Inc. June 2014.   Lorax Environmental Service Ltd. (Lorax), 2016b. Brucejack Gold Mine:   Assessment of Long-Term Sludge Stability for In-lake and Underground   Deposition, Report submitted to Pretium Resources Inc., December 19, 2016.   Lorax Environmental Services Ltd. (Lorax), 2016a. Brucejack Mine: Proposed   Extension for Waste Rock Storage on Surface. Prepared by Lorax Environmental   Services Ltd. for Pretium Resources Ltd. November 9, 2016. Lorax   Environmental Services Ltd. (Lorax), 2017. Assessment of an Increased Volume   of Exposed PAG Waste Rock on the Subaerial Platform at the Brucejack Gold   Mine. Prepared by Lorax Environmental Services Ltd. for Pretium Resources   Ltd. July 21, 2017. Lorax Environmental Services Ltd. (Lorax), 2018.   Brucejack Gold Mine: 2018 Water Quality Model Report in Support of Amendment   Applications for Ore Production Increase to 3800 tpd. Prepared by Lorax   Environmental Services Ltd. for Pretium Resources Ltd. April 11, 2018.   Pretium Resources Inc. (Pretivm), 2015. Applications for Mines Act and   Environmental Management Act Permits. Submitted May 2015. Pretium Resources   Inc. (Pretivm), 2016a. 2015 Annual Report for Mines Act Permit M-243,   Effluent Permit 107835, Air Permit 107025. Submitted March 2016. Pretium   Resources Inc. (Pretivm), 2017. 2016 Annual Report for Mines Act Permit M-243,   Effluent Permit 107835, Air Permit 107025. Submitted March 2017. Pretium   Resources Inc. (Pretivm), 2018a. 2017 Annual Report for Mines Act Permit   M-243, Effluent Permit 107835, Air Permit 107025. Submitted March 2018.   Pretium Resources Inc. (Pretivm), 2019. 2018 Annual Report for Mines Act   Permit M-243, Effluent Permit 107835, Air Permit 107025. Submitted March   2019. Pretivm Resources Inc. (Pretivm), 2018b. 3800 tpd Amendment Application   for Permits M-243 and PE-107835. April 2018. 27.13 Hydrogeology BGC Engineering   Inc., 2013. Brucejack Project Environmental Assessment – Numerical   Hydrogeologic Model. June 18, 2013. BGC Engineering Inc., 2014a. Brucejack   Project Environmental Assessment – Numerical Hydrogeologic Model. June 6,   2014. BGC Engineering Inc., 2015. Brucejack Project MA/EMA Permitting Phase –   Numerical Hydrogeologic Model Update Report. April 27, 2015. BGC Engineering   Inc., 2018. Brucejack Gold Mine – 2017 Annual Groundwater Monitoring Report.   March 19, 2018. BGC Engineering Inc., 2017. Contact Water Pond   Hydrogeological Assessment – DRAFT. Report submitted to Pretium Resources   Inc. January 12, 2017. BGG Engineering Inc., 2019a. 2018 Groundwater   Monitoring Well Installation and Site Investigation Report – FINAL. Report   submitted to Pretium Resources Inc. March 6, 2019. 27-11 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE BGG Engineering Inc., 2019b.   2018 Groundwater Monitoring Report – FINAL. Report submitted to Pretium   Resources Inc. March 6, 2019. DHI, 2020. FEFLOW v7.2.   https://www.mikepoweredbydhi.com/products/feflow. Environmental Simulations   Inc. 2011. Groundwater Vistas – Version 6.   http://www.groundwatermodels.com/Groundwater_Vistas.php. Harbaugh, A.W., E.R.   Banta, M.C. Hill & M.G. McDonald., 2000. Modflow 2000. The U.S.   Geological Survey Modular Ground-water Model – User Guide to the   Modularization Concepts and Ground-water Flow Process. U.S. Geological Survey   Open File Report 00-92, 130 pp. HydroGeoLogic Inc., 2012. Modflow-Surfact – A   Code for Analyzing Subsurface Systems.   http://www.hglsoftware.com/Modflow.cfm. Jones, I.W.O., Huang, J., Horan, M.,   Schmid, C., Carey, E., Ghaffari, H., Rykaart, M., Schmitt, R., Weatherly, H.,   Crozier, T., and Shaw, A., 2019. Feasibility Study and Technical Report on   the Brucejack Project, Stewart, BC. Tetra Tech NI 43-101 Technical Report for   Pretium Resources. Effective Date April 4, 2019. 340 pp. 27.14 Adjacent   Properties American Creek Resources Ltd. website   http://www.americancreek.com. BC MEMPR MINFILE No. 104B 105   http://minfile.gov.bc.ca/Summary.aspx?minfilno=104B%20%20105. Brucejack   Project Overview   http://www.pretivm.com/projects/snowfield/overview/default.aspx (March 29,   2019). Nelson, J., and Kyba, J., 2014. Structural and stratigraphic control   of porphyry and related mineralization in the Treaty Glacier – KSM –   Brucejack – Stewart trend of western Stikinia. In: Geological Fieldwork 2013,   British Columbia Ministry of Energy and Mines, British Columbia Geological   Survey Paper 2014-1, pp. 111–140. Pardoe, J., 2016. NI43-101 Technical Report   on the Treaty Creek Property, Skeena Mining Division British Columbia,   Canada. Report prepared for Tudor Gold Corp. May 21, 2016. Puritch, E.,   Brown, F.H., and Armstrong, T., 2011. Technical Report and Updated Resource   Estimate on the Snowfield Property. February 18, 2100. Seabridge Gold Inc.   website http://www.seabridgegold.net/resources.php. Teuton Resources   Corporation website http://www.teuton.com. 27-12 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Alison Shaw, Ph.D., P.Geo. I,   Alison Shaw, Ph.D., P.Geo. of Vancouver, British Columbia, do hereby certify:   I am a Senior Geochemist with Lorax Environmental Services Ltd. with a business   address at 2289 Burrard Street, Vancouver, British Columbia, V6J 3H9.  This certificate applies to the technical   report entitled “Technical Report on the Brucejack Gold Mine, Northwest   British Columbia” with effective date of March 9, 2020 (the “Technical   Report”).  I am a graduate of McGill   University (B.Sc. Environmental Geosciences, 1996) and the University of   California San Diego (Ph.D. Geochemistry, 2003). I am a member in good   standing of Engineers and Geoscientists British Columbia (# 47412). My   relevant experience includes management, analysis, and interpretation of   geochemical data sets from mine sites, development of site-specific water   quality models, and analysis of water quality data in mine-impacted receiving   environments.  I am a “Qualified   Person” for purposes of National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report from June 3 to June 6, 2019, to review environmental   monitoring programs, assess new water quality sampling locations and tour new   site infrastructure and facilities.  I   am independent of Pretivm Resources Inc. as defined by Section 1.5 of the   Instrument.  My previous experience   with the Property that is the subject of this Technical Report includes   acting as the independent Technical Lead and Qualified Professional for   geochemistry and water quality, responsible for directing the implementation   of geochemistry and water quality monitoring programs; interpretation and   assessment of site monitoring data, including for permit applications and   annual reports; and development and maintenance of the site-specific water   quality model.  I am responsible for   Sections 20.3.2, 20.3.6, 25.6.1, 25.6.5, 26.6.1, 26.6.5, 27.11, 27.12 of this   Technical Report.  I have read the   Instrument and the sections of the Technical Report that I am responsible for   has been prepared in compliance with the Instrument.  As of the date of this certificate, to the   best of my knowledge, information, and belief, the sections of the Technical   Report that I am responsible for contain all scientific and technical   information that is required to be disclosed to make the Technical Report not   misleading.  Signed and dated this 21st   day of April 2020, in Vancouver, British Columbia. “o riginal document signed   and sealed” Alison Shaw, Ph.D., P.Geo. Senior Geochemist Lorax Environmental   Services Ltd. QP Certificate_Alison Shaw.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Calvin Boese, P.Eng., M.Sc.   I, Calvin Boese, P.Eng., M.Sc., of Saskatoon, Saskatchewan, do hereby   certify: I am a Principal Consultant (Geotechnical Engineering) with SRK   Consulting (Canada) Inc. with a business address at Suite 600, 350 3rd Ave   North, Saskatoon, SK, S7K 6G7.  This   certificate applies to the technical report entitled “Technical Report on the   Brucejack Gold Mine, Northwest British Columbia” with effective date of March   9, 2020 (the “Technical Report”).  I am   a graduate of the University of Saskatchewan with a B.Sc. in Civil   Engineering (1999) and a M.Sc. in Geo-Environmental Engineering (2004). I am   a member in good standing of the Association of Professional Engineers,   Geologists of British Columbia (P.Eng. #29478). I am also a registered   Professional Engineer in Alberta and Saskatchewan.  I have practiced my profession for over 20   years. I have been directly involved in geotechnical aspects of mining,   including the site selection, design, permitting, operation, and closure of   mine waste facilities in Canada, the US, Indonesia, and Turkey.  I am a “Qualified Person” for the purposes   of National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report on August 19 to 21, 2019 to complete the annual   geotechnical inspection.  I am   independent of Pretivm Resources Inc. as defined by Section 1.5 of the   Instrument.  My previous experience   with the Property that is the subject of this Technical Report includes   Engineer of Record (EoR) responsibilities for the Waste Rock Tailings Storage   Facility (WRTSF) beginning in Q3 of 2019.    I am responsible for Sections 18.2.2.1, 25.4.3, 26.4.3, and 27.6 of   this Technical Report.  I have read the   Instrument and the sections of the Technical Report that I am responsible for   has been prepared in compliance with the Instrument.  As of the date of this certificate, to the   best of my knowledge, information, and belief, the sections of the Technical   Report that I am responsible for contain all scientific and technical   information that is required to be disclosed to make the Technical Report not   misleading.  Signed and dated this 21st   day of April 2020, in Burnaby, British Columbia. “ origi nal doc u men t s ig   ned and s e ale d” Calvin Boese, P.Eng., M.Sc. Principal Consultant SRK   Consulting (Canada) Inc. QP Certificate_Calvin Boese.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Colin Fraser, P.Geo., M.Sc.   I, Colin Fraser, P.Geo., M.Sc., of Vancouver, British Columbia, do hereby   certify: I am a Senior Hydrologist with Lorax Environmental Services Ltd.   with a business address at 2289 Burrard Street, Vancouver, British Columbia,   Canada, V6J 3H9.  This certificate applies   to the technical report entitled “Technical Report on the Brucejack Gold   Mine, Northwest British Columbia” with effective date of March 9, 2020 (the   “Technical Report”).  I am a graduate   of McMaster University (Hon. B.Sc., 1997) and McGill University (M.Sc.,   1999). I am a member in good standing with Engineers and Geoscientists   British Columbia (License #36348). I am a scientist with experience working   on industry-, academic-, and government-led hydrology and environmental   regulatory initiatives in the forestry, agriculture, oil/gas, and mining   sectors. My academic background is rooted in the hydrology and   biogeochemistry of boreal ecosystems, and I have experience conducting   hydrological, meteorological and water balance studies at mine sites in northern   locations.  I am a “Qualified Person”   for the purposes of National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report between August 19 to August 22, 2019. The objectives   of the site visit were several-fold, and included: meeting site staff who   carry out water and environmental management activities at the Brucejack   Mine; liaising with SRK water engineers; completing a tour of water   management infrastructure and baseline climate/flow monitoring stations at   the property; as well, completing a tour of the Brucejack mill and water   treatment plant.  I am independent of   Pretivm Resources Inc. as defined by Section 1.5 of the Instrument.  My experience with the Property that is the   subject of this Technical Report is limited to technical review and update of   water balance information for the Brucejack mine site.  I am responsible for Sections 20.3.5,   25.6.4, 26.6.4, and 27.10 of this Technical Report.  I have read the Instrument and the sections   of the Technical Report that I am responsible for have been prepared in   compliance with the Instrument.  As of   the date of this certificate, to the best of my knowledge, information, and   belief, the sections of the Technical Report that I am responsible for   contain all scientific and technical information that is required to be   disclosed to make the Technical Report not misleading.  Signed and dated this 21st day of April   2020, in Vancouver, British Columbia. “o riginal document signed and sealed”   Colin Fraser, P.Geo., M.Sc. Senior Hydrologist Lorax Environmental Services   Ltd. QP Certificate_Colin Fraser.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Hassan Ghaffari, P.Eng.,   M.A.Sc. I, Hassan Ghaffari, P.Eng., M.A.Sc., of Vancouver, British Columbia,   do hereby certify:  I am a Director of   Metallurgy with Tetra Tech Canada Inc. with a business address at Suite 1000   – 10th Floor, 885 Dunsmuir Street, Vancouver, British Columbia, V6C 1N5.  This certificate applies to the technical   report entitled “Technical Report on the Brucejack Gold Mine, Northwest   British Columbia” with effective date of March 9, 2020 (the “Technical   Report”).  I am a graduate of the   University of Tehran (M.A.Sc. Mining Engineering, 1990) and the University of   British Columbia (M.A.Sc., Mineral Process Engineering, 2004). I am a member   in good standing of Engineers and Geoscientists British Columbia (#30408). My   relevant experience with respect to mineral engineering includes 27 years of   experience in mining and plant operation, project studies, management, and   engineering. As the lead metallurgist for the Pebble Copper-Gold Moly Project   in Alaska, I was coordinating all metallurgical test work and preparing and   peer reviewing the technical report and the operating and capital costs of   the plant and infrastructure for both the scoping and prefeasibility studies.   For the Ajax Copper-Gold Project in British Columbia, I was the project   manager responsible for process, infrastructure, and overall management of   the 60,000 t/d mill. As well, I was the project manager responsible for   ongoing metallurgical test work and technical assistance for the La Joya   Copper-Silver-Gold Project in Durango, Mexico.  I am a “Qualified Person” for the purposes   of National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report on March 13, 2019. The purpose of the site visit was   to oversee the overall site surface infrastructures including access roads,   warehouses, workshops and process plant.    I am independent of Pretivm Resources Inc. as defined by Section 1.5   of the Instrument.  My previous   experience with the Property that is the subject of this Technical Report   includes Preliminary Economic Assessments in 2010 (Effective Date: September   10, 2010).  I am responsible for   Sections 1.1, 1.9, 1.14, 3.1, 18.1, 18.2 (except 18.2.2.1 and 18.2.3.6),   18.3, 18.4, 18.5, 21.1 (except 21.1.2.4), and 27.7 of this Technical   Report.  I have read the Instrument and   the sections of the Technical Report that I am responsible for has been   prepared in compliance with the Instrument.    As of the date of this certificate, to the best of my knowledge,   information and belief, the sections of the Technical Report that I am   responsible for contain all scientific and technical information that is   required to be disclosed to make the Technical Report not misleading. Signed   and dated this 21st day of April 2020, in Vancouver, British Columbia. “o   riginal document signed and sealed” Hassan Ghaffari, P.Eng., M.A.Sc. Director   of Metallurgy Tetra Tech Canada Inc. QP certificate_Hassan Ghaffari.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Ivor W.O. Jones, M.Sc.,   P.Geo., FAusIMM I, Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM of Robina,   Queensland, Australia, do hereby certify: I am a Principal Consultant with   Ivor Jones Pty Ltd with a business address at 16 Ringwood Court, Robina,   4226, Queensland, Australia.  This   certificate applies to the technical report entitled “Technical Report on the   Brucejack Gold Mine, Northwest British Columbia” with effective date of March   9, 2020 (the “Technical Report”).  I am   a graduate of Macquarie University (B.Sc. Geology, 1984, (Honours), 1986) and   the University of Queensland (M.Sc. Resource Estimation, 2001). I am licensed   as a Professional Geoscientist with Engineers and Geoscientists British   Columbia (Licence No. 197172), and I am a Fellow of the Australasian   Institute of Mining and Metallurgy (AusIMM) (Member No. 111429). I have   worked as a geologist continuously for a total of 35 years since graduation.   I have been involved in resource evaluation for 30 years and consulting for   21 years, including resource estimation of hydrothermal gold deposits for at   least 15 years. I have been involved in gold exploration and mining   operations for at least 20 years.  I am   a “Qualified Person” for the purposes of National Instrument 43-101 (the   “Instrument”).  My most recent personal   inspections of the Property that is the subject of the Technical Report was   from August 20 to August 24, 2018 and April 18, 2020.  I am independent of Pretivm Resources Inc.   as defined by Section 1.5 of the Instrument.    I have had on-going, but periodic involvement with the Property that   is the subject of this Technical Report since 2010. This includes preparation   and sign-off on all Mineral Resources reported by the company since January   2012 with the exception of the 2014 Feasibility Study report.  I am responsible for Sections 1.2, 1.3,   1.4, 1.13, 3.2, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 14.0, 23.0,   25.1, 25.2, 25.9, 26.1, 26.2, 26.3, 27.2, and 27.14 of this Technical   Report.  I have read the Instrument and   the sections of the Technical Report that I am responsible for has been   prepared in compliance with the Instrument.    As of the date of this certificate, to the best of my knowledge,   information, and belief, the sections of the Technical Report that I am   responsible for contain all scientific and technical information that is   required to be disclosed to make the Technical Report not misleading.  Signed and dated this 21st day of April   2020, in Burnaby, British Columbia. “ origi nal doc u men t s ig ned and s e   ale d” Ivor W.O. Jones, M.Sc., P.Geo., FAusIMM Principal Consultant Ivor   Jones Pty Ltd QP Certificate_Ivor Jones.docx 

    

 

TECHNICAL REPORT   ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA 220008-00-RPT-001 |   MARCH 2020 | ISSUED FOR USE Jianhui (John) Huang, Ph.D., P.Eng. I, Jianhui   (John) Huang, Ph.D., P.Eng., of Burnaby, British Columbia, do hereby certify:   I am a Senior Metallurgist with Tetra Tech Canada Inc. with a business   address at Suite 1000 – 10th Floor, 885 Dunsmuir Street, Vancouver, British   Columbia, V6C 1N5.  This certificate   applies to the technical report entitled “Technical Report on the Brucejack   Mine, Northwest British Columbia” with effective date of March 9, 2020 (the   “Technical Report”).  I am a graduate   of North-East University (B.Eng., 1982), Beijing General Research Institute   for Non-ferrous Metals (M.Eng., 1988), and Birmingham University (Ph.D.,   2000). I am a member in good standing of Engineers and Geoscientists British   Columbia (License #30898). My relevant experience with respect to mineral   engineering includes more than 30 years of involvement in mineral process for   base metal ores, gold and silver ores, and rare metal ores.  I am a “Qualified Person” for purposes of   National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report from on March 6 and March 7, 2018 and on June 5 and   June 6, 2018 to witness the operation, review the mill operation and mill   throughput expansion upgrading, and review mill operation data.  I am independent of Pretivm Resources Inc.   as defined by Section 1.5 of the Instrument.    My previous experience with the Property that is the subject of this   Technical Report includes Preliminary Economic Assessment in 2010 (Effective   Date: September 10 2010), Feasibility Study in 2013 (Effective Date: June 21   2013), Feasibility Study Update (Effective Date: June 19, 2014), Technical   Report on the Brucejack Gold Mine (Effective Date: April 4, 2019), mill   upgrading evaluations and technical support during 2017 and 2019.  I am responsible for Sections 1.7, 1.8,   1.11, 2.0, 3.4, 13.0, 17.0, 19.0, 21.2 (except 21.2.2), 24.0, 25.5, 25.7,   26.5, 27.1, and 27.3 of this Technical Report.  I have read the Instrument and the sections   of the Technical Report that I am responsible for has been prepared in   compliance with the Instrument.  As of   the date of this certificate, to the best of my knowledge, information, and   belief, the sections of the Technical Report that I am responsible for   contain all scientific and technical information that is required to be   disclosed to make the Technical Report not misleading.  Signed and dated this 21st day of April   2020, in Vancouver, British Columbia. “ origi nal doc u men t s ig ned and s   e ale d” Jianhui (John) Huang, Ph.D., P.Eng. Senior Metallurgist Tetra Tech   Canadian Inc. QP Certificate_John Huang.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Laura-Lee Findlater, B.Sc.,   P.Geo. I, Laura-Lee Findlater, B.Sc., P.Geo. of Vancouver, British Columbia,   do hereby certify: I am a Project Hydrogeologist with Lorax Environmental Services   Ltd. with a business address at 2289 Burrard Street, Vancouver, British   Columbia, V6J 3H9.  This certificate   applies to the technical report entitled “Technical Report on the Brucejack   Mine, Northwest British Columbia” with effective date of March 9, 2020 (the   “Technical Report”).  I am a graduate   of the University of British Columbia (B.Sc. Honours Geological Sciences,   2001). I am a member in good standing of Engineers and Geoscientists British   Columbia (License #38298). My relevant experience with respect to   hydrogeology includes more than 15 years of management, analysis and   interpretation of physical and chemical hydrogeological data sets from mine   sites. I have both developed and provided oversight for development of   numerical groundwater models for mine sites.    I am a “Qualified Person” for purposes of National Instrument 43-101   (the “Instrument”).  I visited the   Property that is the subject of the Technical Report between October 7 and   October 9, 2019 to observed and provide feedback on groundwater monitoring   practices at the site.  I am   independent of Pretivm Resources Inc. as defined by Section 1.5 of the   Instrument.  My previous experience   with the Property that is the subject of this Technical Report includes   acting as the independent Technical Lead and Qualified Professional for   hydrogeology, responsible for directing the implementation of groundwater   quality and quantity monitoring programs; providing interpretation and   assessment of site monitoring data, including for annual reports; and providing   oversight for the development of the site-specific numerical groundwater   model.  I am responsible for Sections   20.3.3, 25.6.2, 26.6.2, and 27.13 of this Technical Report.  I have read the Instrument and the sections   of the Technical Report that I am responsible for has been prepared in   compliance with the Instrument.  As of   the date of this certificate, to the best of my knowledge, information and   belief, the sections of the Technical Report that I am responsible for   contain all scientific and technical information that is required to be   disclosed to make the Technical Report not misleading.  Signed and dated this 21st day of April   2020, in Vancouver, British Columbia. “ origi nal doc u men t s ig ned and s   e ale d” Laura-Lee Findlater, B.Sc., P.Geo. Project Hydrogeologist Lorax   Environmental Services Ltd. QP certificate_LauraLee Findlater.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Maureen Phifer, P.Eng., B.Sc.   I, Maureen Phifer, P.Eng., B.Sc., of Richmond, British Columbia, do hereby   certify: I am the Mining Division Manager with Tetra Tech Canada Inc. with a   business address at Suite 1000, 10th Floor, 885 Dunsmuir St., Vancouver, BC,   V6C 1N5.  This certificate applies to   the technical report entitled “Technical Report on the Brucejack Gold Mine,   Northwest British Columbia” with effective date of March 9, 2020 (the   “Technical Report”).  I graduated in   2013 from the Montana Technical University with a B.Sc. in Mining   Engineering. I am a member in good standing of with Engineers and   Geoscientists British Columbia (#176335). My relevant experience includes 10   years of experience working in precious metals, onsite operational   experience, and in consulting.  I am a   “Qualified Person” for purposes of National Instrument 43-101 (the   “Instrument”).  I have visited the   Property that is the subject of the Technical Report on January 20 to January   22, 2020.  I am independent of Pretivm   Resources Inc. as defined by Section 1.5 of the Instrument.  I have no prior involvement with the   Property that is the subject of this Technical Report.  I am responsible for the following   sections: 1.5, 1.6, 1.12, 3.5, 15.0, 16.0 (except 16.5), 21.1.2.4, 21.2.2,   22.0, 25.3, 25.4.2, 25.8, 26.4.2, and 27.4 of this Technical Report.  I have read the Instrument and the sections   of the Technical Report that I am responsible for has been prepared in   compliance with the Instrument.  As of   the date of this certificate, to the best of my knowledge, information, and   belief, the sections of the Technical Report that I am responsible for   contain all scientific and technical information that is required to be   disclosed to make the Technical Report not misleading.  Signed and dated this 21st day of April   2020, in Vancouver, British Columbia. “o riginal document signed and sealed”   Maureen Phifer, P.Eng., B.Sc. Manager, Mining Division Tetra Tech Canada Inc.   QP Certificate_Maureen Phifer.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Mauricio Herrera, P.Eng.,   Ph.D. I, Mauricio Herrera, P.Eng., Ph.D., of Vancouver, British Columbia, do   hereby certify: I am a Principal Consultant (Water Resources Engineering)   with SRK Consulting (Canada) Inc. with a business address at Suite 2200, 1066   West Hastings St., Vancouver, BC, V6E 3X2.    This certificate applies to the technical report entitled “Technical   Report on the Brucejack Gold Mine, Northwest British Columbia” with effective   date of March 9, 2020 (the “Technical Report”).  I am a graduate of Universidad del Norte   (Colombia) with a B.Sc. in Civil Engineering (1997), a M.Sc. in Water Resources   Engineering (1998) from Universidad de los Andes (Colombia), and a Doctorate   in Water Resources Engineering from the University of Guelph (Ontario). I am   a member in good standing of Engineers and Geoscientists British Columbia   (P.Eng. #34942). I am also a registered Professional Engineer in Alberta and   in the Yukon. I have practiced my profession for over 20 years. I have been   directly involved in surface water management aspects of mining, including   the site selection, design, permitting, operation, and closure of mine waste   facilities in Canada.  I am a   “Qualified Person” for the purposes of National Instrument 43-101 (the   “Instrument”).  I visited the Property   that is the subject of the Technical Report on August 19 to August 21, 2019   to complete the Annual Surface Water Management Inspection.  I am independent of Pretivm Resources Inc.   as defined by Section 1.5 of the Instrument.    My previous experience with the Property that is the subject of this   Technical Report includes Engineer of Record (EoR) responsibilities for the   Surface Water Management beginning in Q3 of 2019.  I am responsible for Sections 18.2.3.6,   20.3.4, 25.6.3, 26.6.3, and 27.9 of this Technical Report.  I have read the Instrument and the sections   of the Technical Report that I am responsible for has been prepared in compliance   with the Instrument.  As of the date of   this certificate, to the best of my knowledge, information, and belief, the   sections of the Technical Report that I am responsible for contain all   scientific and technical information that is required to be disclosed to make   the Technical Report not misleading.    Signed and dated this 21st day of April 2020, in Vancouver, British   Columbia. “ origi nal doc u men t s ig ned and s e ale d” Mauricio Herrera,   P.Eng., Ph.D. Principal Consultant SRK Consulting (Canada) Inc. QP   Certificate_Mauricio Herrera.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Rolf Schmitt, M.Sc., P.Geo I,   Rolf Schmitt, M.Sc., P.Geo, of Victoria, British Columbia, do hereby certify:   I am a Technical Director - Permitting with Environmental Resources   Management (ERM) with a business address at 15th Floor, 1111 West Hastings   Street, Vancouver, British Columbia, Canada V6E 2J3.  This certificate applies to the technical   report entitled “Technical Report on the Brucejack Gold Mine, Northwest   British Columbia” with effective date of March 9, 2020 (the “Technical   Report”).  I am a graduate of   University of Ottawa (M.Sc., 1993 – Geology), University of British Columbia   (M.Sc., 1985 Regional Planning), and University of British Columbia (B.Sc.,   Hons. Geology, 1977). I am a member in good standing of the Engineers and   Geoscientists of British Columbia (License #19824). My relevant experience   with respect to environmental assessment, mine permitting and geology   includes more than 40 years of involvement in BC mine policy and regulation,   including 16 years as BC Senior Land Use Geologist, 14 years leading   Environmental Assessment and permitting of mines in BC as a consultant, and   15 years previously of mineral exploration and exploration geochemical   research in northwestern BC and eastern Canada.  I am a “Qualified Person” for the purposes   of National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report on April 1 to April 3, 2019 to examine environmental   management systems at the Brucejack Mine Site.  I am independent of Pretivm Resources Inc.   as defined by Section 1.5 of the Instrument.    My previous experience with the Property that is the subject of this   Technical Report includes contributions, reviews and amendments to the   applications for EA Project Certificate, Mines Act permit M-243, and   Environmental Management Act waste discharge permits, crown land tenure,   related permits.  I am responsible for   Sections 1.10, 3.3, 20.1 to 20.3.1, 20.3.7 to 20.3.9, and 27.8 of this   Technical Report.  I have read the   Instrument and the sections of the Technical Report that I am responsible for   have been prepared in compliance with the Instrument.  As of the date of this certificate, to the   best of my knowledge, information, and belief, the sections of the Technical   Report that I am responsible for contain all scientific and technical   information that is required to be disclosed to make the Technical Report not   misleading.  Signed and dated this 21st   day of April 2020, in Vancouver, British Columbia. “ origi nal doc u men t s   ig ned and s e ale d” Rolf Schmitt, M.Sc., P.Geo Technical Director   Environmental Resources Management (ERM) QP Certificate_Rolf Schmitt.docx 

    

 

TECHNICAL   REPORT ON THE BRUCEJACK GOLD MINE, NORTHWEST BRITISH COLUMBIA   220008-00-RPT-001 | MARCH 2020 | ISSUED FOR USE Timothy James Coleman,   P.Eng., BEng(Hons), ACSM, M.Sc. I, Timothy James Coleman, P.Eng., of   Coquitlam, British Columbia, do hereby certify: I am a Principal Consultant   with SRK Consulting (Canada) Inc with a business address at Suite 2200 – 1066   West Hastings Street, Vancouver, British Columbia, V6E 3X2, Canada.  This certificate applies to the technical   report entitled “Technical Report on the Brucejack Gold Mine, Northwest   British Columbia” with effective date of March 9, 2020 (the “Technical   Report”).  I am a graduate of Imperial   College of Science, Technology and Medicine, UK in where I obtained my M.Sc.   Engineering Rock Mechanics in 1997. I obtained a BEng (Honours) Mining   Engineering in 1994, and a Diploma in Minerals Engineering (1st Class) in   1992, both from The Camborne School of Mines, University of Exeter, UK. I have   been involved in mining since 1997 and have practised my profession   continuously since then. I have been involved in mining operations,   mining-related rock mechanics and consulting covering a wide range of mineral   commodities in the United Kingdom, Europe, North and South America, Africa,   and Asia. I am a registered Professional Engineer (#46105) with EGBC and also   registered in the provinces of Ontario and Saskatchewan.  I am a “Qualified Person” for the purposes of   National Instrument 43-101 (the “Instrument”).  I visited the Property that is the subject   of the Technical Report on September 24, 2019 to conduct a review of the   underground workings and rock mass conditions.  I am independent of Pretivm Resources Inc.   as defined by Section 1.5 of the Instrument.    My previous experience with the Property that is the subject of this   Technical Report includes the annual underground inspection, the annual   review of the GCMP, and review of the waste rock pastefill barricade   design.  I am responsible for Sections   16.5, 25.4.1, 26.4.1, and 27.5 of this Technical Report.  I have read the Instrument and the sections   of the Technical Report that I am responsible for has been prepared in   compliance with the Instrument.  As of   the date of this certificate, to the best of my knowledge, information, and   belief, the sections of the Technical Report that I am responsible for   contain all scientific and technical information that is required to be   disclosed to make the Technical Report not misleading.  Signed and dated this 21st day of April   2020, in Burnaby, British Columbia. “ origi nal doc u men t s ig ned and s e   ale d” Tim Coleman, P.Eng., BEng(Hons), ACSM, M.Sc. Principal Consultant,   Mining Rock Mechanics SRK Consulting (Canada) Inc. QP Certificate - Tim   Coleman.docx

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