OVE VERVI VIEW EW PR PRESEN ESENTATION TION MVLWB Technical - PowerPoint PPT Presentation

OVE VERVI VIEW EW PR PRESEN ESENTATION TION MVLWB Technical Session Snap Lake Mine Final Closure, and Water Licence and Land Permit Renewal July 16 to 18, 2019 PUBLIC LIC PRESEN ENTATION ION

AN Storag rage Emuls lsio ion Plant ant TOTAL AL IMAGE GE Airstrip ip North th Pile le Water r Mana nageme ment nt Pond nd Fuel l Storag rage Camp mp Proc ocess ess Plant ant Porta tals ls Water r Trea eated ed Trea eatme ment nt Plant ant Water r Disch scharg rge

REGUL GULATOR ORY UPDATE TE • Underground mine 2008-2015 • Mining ended December 2015 • Extended care and maintenance 2016-2019 • Closure activities to begin in 2020 • Water licence - Current mining and milling licence expires in June of 2020 - MVLWB determined that a class A water licence is needed - Renewed water licence for closure and post-closure activities • Final Closure and Reclamation Plan (FCRP) - Approval is required prior to implementation of closure activities - FCRP is the guiding management plan for all closure/post-closure activities - FCRP builds on the previously approved ICRP • Closure and Post-closure are phases in the life of Snap Lake Mine • Closure will begin following approval of the FCRP and issuance of the new water licence, anticipated in Q1 2020 2

WATER ER LICENCE ENCE APPLICA CATION TION TABLE E OF CONTE TENTS • Water Licence Application Form • Final Closure and Reclamation Plan Site Plan - Glossaries • - Concordance Table • Fee • Draft water licence - Engagement (1) • Engagement Record - Lessons Learned • Effluent Quality Criteria Report for Closure and Post-closure - Summary of Research Program Status Aquatic Effects Re-evaluation Report - Financial Security Estimate • (2) - Demolition Inventories and Site Closure Plans • AEMP Design Plan for Closure and Post-Closure • Engagement Plan - North Pile Closure Cover Design • Spill Contingency Plan - Snap Lake Mine Post-Closure Problem Formulation (HHERA) • Emergency Response Plan - Revegetation Plan Waste Management Plan - Geochemistry Review • (4) - Water Management Design • Water Management Plan • North Pile Management Plan • Responses to reviewer comments • Air Quality and Emissions Monitoring and Management Plan • Follow-ups to proponent responses: • Wildlife Monitoring Plan - Cormix Model (3) - Table 5-1 Vegetation and Soils Monitoring Plan • 3

KEY CHANGES GES/UPD /UPDATE TES (1) Water Licence • Scope no longer includes mining or processing • Term length = 15 years • 8 years closure; • 5 years post-closure; • 2 years security return/contingency • Aligns with closure and post-closure activities • Updated Site Plan Land Use Permit • Adjusted Condition 50 for adjustment of securities • Adjusted Condition 1 to allow for a temporary camp to be used during demolition Record of Engagement • Letters of notice Meetings • • Workshops 4

KEY CHANGES GES/UPD /UPDATE TES (2) Effluent Quality Criteria • Re-evaluation of the EQC to meet the AEMP benchmarks at the mixing zone boundary • AEMP benchmarks updated to align with current approvals, updated guidelines • One simple set of EQC for closure and post-closure (adjusted post technical review) • Active treatment will continue until surface water meets EQC • Sumps will be converted to gravity drained ditches and ponds (influent storage) • If required, wetlands will be constructed Closu osure re Efflu luen ent t Quality lity Criter eria ia Parame ameter ers s of Pot oten entia ial Concern Maximu imum m Aver erage age Maximu imum m Grab ab Concen entr tratio ation Conc ncentr tratio ion Nitrate, as N (mg/L) 25 50 Total suspended solids (mg/L) 15 25 Faecal coliforms (CFU/100 mL) * 10 20 pH 6.5 to 9.0 5 * closure only

KEY CHANGES GES/UPD /UPDATE TES (2) Aquatic Effects Monitoring Program • Re-evaluation of the results to date • No evidence of adverse effects on aquatic life or drinkability of SL water • Fish are in good health and continue to survive, grow and reproduce • Design plan for Closure and Post-closure • All components will be monitored • water quality, • sediment quality, • toxicity • plankton • benthic invertebrates • fish health and tissue fish tasting • • Response framework continues • Revised frequencies of monitoring 6

KEY CHANGES GES/UPD /UPDATE TES (3) Manag agement ent Plan Key Updates Engagement Plan Formatting, general updates to align with closure and post-closure activities Spill Contingency Plan Formatting, general updates to align with closure and post-closure activities Emergency Response Plan Formatting, general updates to align with closure and post-closure activities Waste Management Plan Details ails of land ndfill fill operatio ions ns, formatting, general updates to align with closure and post-closure activities Water Management Plan Updated water balanc lance, e, water manag nageme ement nt system em components nents includ udin ing g north h pile perimeter water er control ol struc uctur ures, es, influent fluent storag age ponds, construc ucted wetland lands, SNP, formatting and general updates. North Pile Management Plan Updated clos osur ure desig ign n descriptio ions ns includ luding ing cover and passive treatment ent system, em, updat ated closur ure and post- closure geotech ch monit itoring ing plan, formatting, general updates to align with closure and post-closure activities 7

KEY CHANGES GES/UPD /UPDATE TES (4) Final Closure and Reclamation Plan • Fully describes the plans for Snap Lake Mine during closure and post-closure • Meets the requirements of the Guidelines • Objectives as previously approved in the ICRP • Criteria refined from previous feedback • Updated Project Environment • Detailed Permanent Closure and Reclamation • Completion Reporting: • reclamation completion reports and • performance assessment reports • Updated Security estimate (increasing the estimate by $6M) • Proposed stages for security return • Stage 1 – End of closure (year 8) • Optional – Stage 1a Closure (year 2) • Stage 2 – Post-closure Phase (~once/3-5 years) 8

CONSTR TRUCTION CTION SEQUENC UENCING G / SCHEDULI EDULING G OF WETLANDS ANDS AND WATER ER DISCH SCHAR ARGE GE Activity 2019 2019 2020 2020 2021 2021 2022 2022 2023 2023 2024 2024 2025 2025 2026 2026 2027 2027 2028 2028 2029 2029 2030 2030 2031 2031 2032 2032 2033 2033 2034 2034 2035 2035-2045 2045 Water Licence Process Winter Road 1 Water Management System and North Pile Cover Construction (Influent Storage Ponds, Wetlands and spillways) Monitoring of System Biota Growth and Denitrification Demolition Winter Road Active Demolition Revegetation, Landforming and Site Stabilization Final Winter Road Extended Care and Maintenance Post Closure 9

CONCL CLUSIO USIONS • Mining and milling are no longer planned activities • Final closure plan describes all planned activities • Monitoring will continue through closure and post-closure • Water management is limited to surface water • Closure will involve: • Cover the North Pile • Convert the drainage around the pile from active to passive • Convert sumps/water management pond into influent storage ponds • Wetlands may be constructed: • If required to treat Nitrate • If not required, water will passively drain to Snap Lake • Demolition of process plant, camp, and all buildings • Revegetation of roads, pads, and priority infrastructure areas • Post-closure will involve: • Monitoring 10 10