Nyrstar Myra Falls Mine Pär Göting General Manager 250-287-9271 (3279) Par.Goting@nyrstar.com

Nicole Pesonen Acting Health, Safety, Environment, and Communities Manager 250-287-9271 (3316) Nicole.Pesonen@nyrstar.com

Annual Reclamation Report 2019 Prepared by: Craig Schweitzer Reviewed by: Keith Watson Submitted as required under Mine’s Act Permit M-26 to BC EMPR Revised April 30, 2020

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Executive Summary

The following report details the mining and reclamation activities under Mine’s Act permit M-26 for the calendar year 2019. The mining operation is located within Myra Valley with additional mining infrastructure in Thelwood Valley and occupies a footprint of 185.0 ha within Strathcona-Westmin Provincial Park, excluding hydro dam infrastructure.

The reclamation program at Myra Falls has been developed with two major objectives in mind.

The primary objective is the long term safety and stability of the site; this will be achieved through land-forming to create geotechnically stable structures and collection of contact water for treatment. The secondary objective to create conditions that will allow the site to develop into a stable self-sustaining ecosystem consistent with the Strathcona-Westmin Provincial Park Master Plan (R. J. Lampard, District Manager, 1995), and returned to Class A Park upon final closure.

Construction efforts in 2019 focussed on areas within the existing mine footprint, primarily on the Lynx Tailings Disposal Facility (Lynx TDF) berm raise. Physical reclamation work in 2019 was comprised of the removal of waste rock from Dumps 2 and 3 in support of the Waste Rock Stabilization work and the removal of the Lower Lynx Ore Chute.

Surface water monitoring was conducted as required by the Effluent Permit PE-06858 and is reported in detail in Appendix 5.

Five groundwater seep systems have been broadly identified and are monitored during high precipitation events. Monitoring results for the seeps indicate that the improvements noted in the 2016 report have persisted; results from monitoring in 2019 are included in Appendix 5.

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TABLE OF CONTENTS EXECUTIVE SUMMARY .............................................................................................................................. 0 INTRODUCTION ........................................................................................................................................... 3 SCOPE OF REPORT .................................................................................................................................... 3 NYRSTAR MYRA FALLS OVERVIEW ......................................................................................................... 3 REGIONAL ENVIRONMENTAL/ECOLOGICAL CONDITIONS ................................................................... 6 LOCATION AND TOPOGRAPHY ................................................................................................................. 6 MYRA CREEK DRAINAGE SYSTEM ........................................................................................................... 7 CLIMATE ....................................................................................................................................................... 7 REGIONAL MANAGEMENT PLANS ............................................................................................................ 8 RECLAMATION PROGRAM ......................................................................................................................... 8 2019 RECLAMATION SUMMARY ................................................................................................................ 9 PROGRESSIVE RECLAMATION ............................................................................................................... 10 MINING PROGRAM .................................................................................................................................... 13 SURFACE DEVELOPMENT TO DATE ...................................................................................................... 13 CURRENT LIFE OF MINE PLAN ............................................................................................................... 13 SURFACE DEVELOPMENT IN THE PAST YEAR..................................................................................... 13 MINING AND MILLING PRODUCTION ...................................................................................................... 15 WASTE ROCK DUMPS .............................................................................................................................. 17 GROWTH MEDIUM .................................................................................................................................... 17 SURFACE DEVELOPMENT PROJECTED OVER THE NEXT FIVE YEARS ........................................... 17 ENVIRONMENTAL MANAGEMENT SYSTEM .......................................................................................... 18 ML/ARD CHARACTERIZATION AND MANAGEMENT ............................................................................. 19 SURFACE WATER QUALITY AND QUANTITY......................................................................................... 19 BC MINISTRY OF ENVIRONMENT WATER QUALITY MONITORING (PERMIT PE-06858) .................. 21 FLOW MONITORING ................................................................................................................................. 22 GROUNDWATER QUALITY AND QUANTITY ........................................................................................... 23 SEEP MONITORING .................................................................................................................................. 24 WATER QUALITY PREDICTION, MITIGATION AND TREATMENT......................................................... 24 WATER MANAGEMENT ............................................................................................................................ 25 ARNICA DIVERSION DITCH ...................................................................................................................... 27 LYNX DIVERSION SYSTEM ...................................................................................................................... 27 OLD TDF AND AMALGAMATED PASTE AREA (APA) DECANT SYSTEM ............................................. 28 LYNX TDF, WASTE ROCK DUMPS AND LYNX MINE ............................................................................. 28 EROSION AND SEDIMENT CONTROL ..................................................................................................... 30 SOIL AND SALVAGE STOCKPILING ........................................................................................................ 30 VEGETATION MANAGEMENT .................................................................................................................. 30 WILDLIFE PROTECTION ........................................................................................................................... 31 ARCHAEOLOGICAL RESOURCES ........................................................................................................... 31 RECLAMATION PROGRAM ....................................................................................................................... 32 END LAND-USE ......................................................................................................................................... 32 LAND CAPABILITY ..................................................................................................................................... 32 LONG-TERM STABILITY ............................................................................................................................ 33 REVEGETATION ........................................................................................................................................ 33 GROWTH MEDIUM .................................................................................................................................... 35 LANDFORMS .............................................................................................................................................. 35 WASTE DUMP RECLAMATION ................................................................................................................. 35 WATERCOURSE RECLAMATION ............................................................................................................. 37 OPEN PIT RECLAMATION ........................................................................................................................ 37 TAILINGS STORAGE FACILITIES / IMPOUNDMENT RECLAMATION ................................................... 37 ROAD RECLAMATION ............................................................................................................................... 37 STRUCTURES AND EQUIPMENT ............................................................................................................ 37

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SECURING OPENINGS ............................................................................................................................. 37 EVENTS OUTSIDE OF NORMAL OPERATIONAL PARAMETERS.......................................................... 38 DISPOSAL OF CHEMICALS AND REAGENTS......................................................................................... 38 RECLAMATION RESEARCH ..................................................................................................................... 39 5 YEAR RECLAMATION PLAN .................................................................................................................. 39 RECLAMATION COST ASSESSMENT ..................................................................................................... 39 CLOSURE ................................................................................................................................................... 40 BIBLIOGRAPHY ......................................................................................................................................... 41 TABLE OF FIGURES FIGURE 1: REGIONAL LOCATION OF MYRA FALLS MINE ...................................................................... 5 FIGURE 2: SITE PLAN AS OF DEC 31, 2019 ............................................................................................ 12 FIGURE 3: MYRA CREEK AND EFFLUENT FLOWS WITH PRECIPITATION ........................................ 23 FIGURE 4: FLOW REGIME THROUGH MYRA POLISHING PONDS....................................................... 25 FIGURE 5: ANNUAL PRECIPITATION 2019 ............................................................................................. 26 FIGURE 6: CRAB FOLLOWING HYDROSEED APPLICATION WITH NATIVE SEEDS OCTOBER 12,

2016 .................................................................................................................................................... 34 FIGURE 7: CRAB APRIL 2020 ................................................................................................................... 35 FIGURE 8: ALDER REACH MARCH 2018 - 1 SEASON VEGETATION GROWTH ................................. 36 FIGURE 9: DUMP 2 FROM CAMP 2016 PRIOR TO RECONTOURING .................................................. 36 FIGURE 10: DUMP 2 FROM PHILLIPS REACH 2016 PRIOR TO RECONTOURING ............................. 36 FIGURE 12: DUMP 2 FROM CAMP MARCH 2020 AFTER 3 YEARS OF RECONTOURING ................. 36 FIGURE 11: ALDER REACH MARCH 2020 - 3 SEASONS OF VEGETATION GROWTH ....................... 36 FIGURE 13: DUMP 2 FROM PHILLIPS REACH MARCH 2020 ................................................................ 36 TABLE OF TABLES TABLE 1: MINING LEASES AND CROWN GRANTS ASSOCIATED WITH M-26 ...................................... 6 TABLE 2: SUMMARY OF AREAS DISTURBED AND RECLAIMED 2018 ................................................ 10 TABLE 3: QUANTITIES OF WASTE ROCK, TAILINGS, LOW GRADE ORE, COARSE REJECT AND

OTHER MINE WASTE AS OF DECEMBER 31, 2019 ....................................................................... 15 TABLE 4: MONTHLY MINING AND MILLING PRODUCTION AS OF DECEMBER 31, 2019 .................. 16 TABLE 5: (EMPR TABLE 5) QUANTITIES OF SOIL & OVERBURDEN SALVAGED & STOCKPILED FOR

RECLAMATION USE AS OF DECEMBER 31, 2018 ......................................................................... 17 TABLE 6: HYDROSEED BLEND USED 2016 ............................................................................................ 34 TABLE 7: SUMMARY OF EVENTS OUTSIDE OF NORMAL OPERATIONAL PARAMETERS ............... 38 APPENDICES APPENDIX 1: MAPS / SITE PLANS APPENDIX 2: NYRSTAR MYRA FALLS MINE TOPSOIL MANAGEMENT PLAN APPENDIX 3: ARD/ML MANAGEMENT PLAN APPENDIX 4: NAUTILUS TOXICITY REPORTS APPENDIX 5: 2019 ANNUAL WATER QUALITY REPORT APPENDIX 6: INTEGRAL ECOLOGY GROUP MEMORANDUM APPENDIX 7: ROBERTSON GEOCONSULTANTS MEMORANDUM

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Introduction

Scope of Report

The following report details the mining and reclamation activities under Mine’s Act permit M-26 for the calendar year 2019. The report includes a review of mining and reclamation activities, a summary of unusual events occurring in 2019, a discussion on the changes in the mining activity, and a projection of significant activities planned for 2020.

The operating company is registered as 822638-5, Nyrstar Myra Falls Ltd. (NMF). The company contacts for the location are:

Pär Göting General Manager 250-287-9271 (3279) Par.goting@nyrstar.com

Nicole Pesonen Environmental Superintendent 250-287-9271 (3316) Nicole.pesonen@nyrstar.com

Nyrstar Myra Falls Overview

Myra Falls is a historic base metal mine located at the south end of Buttle Lake on Vancouver Island, 90 km southwest of the city of Campbell River. The mining and milling operation produced zinc, copper and lead concentrates with silver and gold credits. Ore concentrate was trucked to a port terminal in Campbell River where it was shipped to refining smelters around the world. The mine has been operating since 1966 with peak production in excess of 1.3M tonnes/year.

Trafigura is the majority owner of the operating business of Nyrstar, a global multi-metals business with a market leading position in zinc and lead, and growing positions in other base and precious metals. Nyrstar has mining, smelting and other operations located in Europe, the Americas and Australia and employs over 4,000 people. The company’s global operations are located close to key customers and major transport hubs to facilitate delivery of raw materials and distribution of finished products.

The Myra Falls mining operation occupies a footprint of 185.0ha within Strathcona-Westmin Provincial Park. The park was partitioned from the Strathcona ‘Class A’

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Provincial Park in 1965 and designated as a ‘Class B’ provincial park due to industrial activity. Strathcona-Westmin ‘Class B’ Provincial Park covers the area permitted for the mine to carry out its mining operations. The land was given special designation due to its mineral values and the decision by the provincial government to allow exploration and mining in this area. Mining began in 1966 and will continue as long as reserves and commodity prices permit. The property extends over parts of Phillips Ridge, Myra Valley, Mount Myra, Thelwood Valley and Price Valley. Myra Falls also operates under Park Use Permits issued by BC Parks. These permits authorize the use of ‘Class B’ parklands for mining, power generation, power transmission and roads. The current land use in the Myra Valley is for mining and mining-related purposes.

Figure 1: Regional Location of Myra Falls Mine

The 3,328 ha area of Strathcona-Westmin ‘Class B’ Provincial Park is held as crown grants, mining leases and claims, issued under the Mine’s Act by the Ministry of Energy and Mines (EMPR).

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The mine property is comprised of 6 Crown-granted mining leases and 23 Crown-granted mineral rights, all wholly owned by Nyrstar Myra Falls Ltd (see Table 1). Site offices are located within L1344 Being Bear Paw Mineral Claim, Clayoquot District.

Table 1: Mining Leases and Crown Grants Associated with M-26 Crown Grants Mining Leases

L1671, L1670, L1669, L1668, L1667, L1666, L1665, L1664, L1663, L1661, L1660, L1659, L1340, L1341, L1342, L1344, L1345, L1346, L1347, L1971, L1972, L1973, L1974

Lease 201320, Lease 201321, Lease 201322, Lease 201323, Lease 201324, Lease 1069356

Other key contact information for Nyrstar Myra Falls follows:

Corporate Office: Zurich, Switzerland Tessinerplatz 7 8002 Zurich Switzerland Tel: +41 (0)44 745 8100 Fax: +41 (0)44 745 8110

Registered Office: Balen, Belgium Zinkstraat 1 B-2490 Balen Belgium Tel: +32 (0)14 44 95 00

Trafigura Branch Office: Trafigura PTE Ltd. 1, rue de Jargonnant 1207 Geneva Switzerland

Regional Environmental/Ecological Conditions

Location and Topography

The footprint of the Nyrstar Myra Falls mine site straddles the Myra Valley and the lower reaches of Myra Creek. Myra Creek flows from west to east through a steep-sided hanging valley and discharges over Myra Falls into Buttle Lake. Three main tributaries feed Myra Creek within the site boundaries: Tennent Creek and Webster Creek from the south side and Arnica Creek from the north side. Also draining from the north side is the Lynx Diversion Ditch, an engineered water channel which runs along the northern perimeter of the site, diverting clean water away from the waste rock piles and tailings impoundment facilities.

The slopes of Myra Valley climb steeply with an average gradient of 1.5H:1V. To the south, the slope rises to 1814 m at the summit of Mount Myra from the average valley bottom elevation of 307 meters above sea level (MASL). Topography in the area exerts

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a strong influence on air mass movement and wind directions. Winds blow predominantly along the axis of the Myra Valley. At night, air masses are drawn down the mountains, continue along the valley floor and out over Buttle Lake. During the day, winds up cast along the mountainsides with air masses typically moving up the valley. Wind velocities at NMF are generally low, typical of sites in protected valleys.

Myra Creek Drainage System

Myra Creek has a total length of 16 km and drains an area of 72 km2 into Buttle Lake. Myra Creek and its tributaries are characterized by steep, cascading mountain streams bounded by rock. The creek descends in elevation from 1,814 m to 221 m at Buttle Lake. Its three major tributaries are Tennent Creek, Arnica Creek and Webster Creek.

Myra Creek flow is monitored at the “Red Bridge” near the former backfill plant with a radar stage sensor and data logger system, installed in October 2019. The system logs creek-stage measurements at 15 minute intervals. Stage measurements are converted to flow using a stage-discharge curve calculation. A second monitoring station is located at the “car bridge” leading from the HW complex to the Mill Area. It uses a pressure transducer and logger system and is in place to allow a comparison of flows between the “new” radar station and the historical location at the car bridge with data recorded simultaneously.

Climate

The climate in the Myra Valley and surrounding areas is classified as Marine West Coast as per the Köppen Climate Classification System. Weather patterns are typical of other coastal regions of British Columbia. Frequent fronts from the Pacific Ocean and Gulf of Alaska combine with orographic influences to produce abundant precipitation. Prevailing westerly winds and the moderating influence of the Pacific Ocean result in generally mild winters and warm summers, producing a relatively narrow annual temperature range. Freezing conditions can be expected to occur anytime from October through May. Records indicate that the site should average 160 frost-free days per year.

Myra Falls has been operating an automated weather station/data logger since 2012. This was run concurrently with the old Powerhouse Weather Station until mid-2016, when use of the Powerhouse station was discontinued.

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Regional Management Plans

Nyrstar Myra Falls Mine is located within the boundaries of Strathcona-Westmin Provincial Park, a 3,328 ha Class "B" Provincial Park that was established to recognize an operating mine. As portions of the Park are no longer needed for mining activities, they will be added progressively to Strathcona Provincial Park.

As stated in the (R. J. Lampard, District Manager, 1995) “The Master Plan for Strathcona Provincial Park was approved in 1993 and defines land use and development for areas adjacent to Strathcona-Westmin Provincial Park. Accordingly, the Strathcona-Westmin Provincial Park Master Plan (approved in 1995), must recognize the direction and constraints that the Strathcona Provincial Park Master Plan places on land use and ensure that the actions specified in this plan have a minimal effect on Strathcona Provincial Park. The goal of this Master Plan is to accommodate the mine and, at the same time, protect the natural resources and provide recreation opportunities within the Park.”

Nyrstar has continued to commit to an ongoing cooperative relationship with BC Parks in carrying out the goals of the Park Plan.

Reclamation Program

The reclamation program at Myra Falls has been developed with two major objectives in mind.

The primary objective is the long term safety and stability of the site; this will be achieved through land-forming to create geotechnically stable structures and collection of contact water for treatment. The secondary objective to create conditions that will allow the site to develop into a stable self-sustaining ecosystem consistent with the Strathcona-Westmin Provincial Park Master Plan (R. J. Lampard, District Manager, 1995) will be achieved through growth medium replacement and revegetation utilizing native pioneer species. Class A Parks are meant for the preservation of natural environments for the inspiration, use and enjoyment of the public (Province Of British Columbia, 2018). The reclamation program for Myra Falls will leave infrastructure in place as approved by BC Parks such as access roads, parking areas and bridges where utilized by the public to access trails and recreation sites in the park. Interpretive signs may also be installed in areas to provide learning opportunities to the public both during active operations and post closure.

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Reclamation works will be conducted in such a way to allow natural ingress of the species native to the region, suitable for the end use soil and moisture regimes. The target climax state for Myra Falls is western hemlock, with a secondary succession of mixed conifers and alder that is expected to become mature and stable after 30 years, lasting for centuries (Integral Ecology Group, July 2014).

In the Mine’s Act permit M-26 amendment issued September 28, 2018, by the BC Ministry of Energy, Mines and Petroleum Resources (EMPR), conditions were issued that require Nyrstar to develop a formal Reclamation Research and Monitoring Program to be submitted in 2019 for review. This program includes a mitigation plan for habitat impacts related to mining activities, including mitigation for loss of habitat and ecosystem structures from the site relative to the pre-mining state of the area. This package included five separate documents submitted in October and December outlining the pre-mining conditions and the current conditions, along with post-mining habitat mapping and a suggested research program. This work will be utilized to inform the next Five-year Mine and Reclamation Plan, due to be submitted to the EMPR January 31, 2021. The Closure Objectives will be re-evaluated at that time.

2019 Reclamation Summary

Reclamation activities in 2019 were focussed on stabilization of the Waste Rock Dumps 2 and 3, removing 173,747 cubic meters (m3) of waste from the hillslope and repurposing it in the construction of the Lynx TDF. There were no additional hectares of completed recontouring in 2019; volumes remaining in the waste rock dumps for final closure have decreased.

The lower section of the Lower Lynx Ore Chute was removed in 2019, with the upper section planned for removal in 2020.

Phase II of The Lynx Seepage Interception System (Lynx SIS), which consists of a fence of four (4) shallow water collection wells was installed in February 2019; additional groundwater wells were installed in the mill and camp areas to facilitate closer monitoring of the groundwater behaviour in those areas. The system has run continuously since then, with the exception of periods of maintenance or repair.

Design work for the Old TDF Closure Cover Phase 1 was completed, in anticipation of construction in 2020, pending permitting.

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Table 2: Summary of Areas Disturbed and Reclaimed 2018

Progressive Reclamation

Progressive reclamation is targeted to complete the site-wide closure plan in small, manageable projects. Very little progressive reclamation has occurred since the removal of the tailings pipeline to Buttle Lake as the majority of the surface works were required for active mining and milling. More recently several facilities have reached the planned life and are slated for progressive reclamation works over the next five years. These include the Old TDF, Waste Rock Dumps 2, 3, and 6, and buildings such as the old backfill plant and the older camp buildings.

NMF has committed to develop new infrastructure with progressive and final reclamation in mind. To facilitate this effort, Nyrstar commissioned Wood Environment & Infrastructure Solutions (Wood) to develop a closure cover design for the Lynx TDF (Amec Foster Wheeler, December 2016 a) that can be constructed with each

MINING RECLAMATION Disturbance

Area Area Area

Seeded/ Area Area

Disturbed Recontoured Planted Fertilized Revegetated (ha) (ha) (ha) (ha) (ha) 2019 Total 2019 Total 2019 Total 2019 Total 2019 Total Waste Dumps 0 28.7 0 4.4 0 0 0 0 0 0 Tailings Facilities 0 61.8 0 0 0 3.8 0 3 0 1 All Infrastructure Features 0 31.3 0 0 0 0 0 0 0 0

Roads 0 22.2 0 17.3 0 21.3 0 21.3 0 14.3

Rock Pits 0 10.7 0 0 0 0 0 0 0 0 Stockpiles 0 0 0 0 0 0 0 0 0 0 Clean Fill Borrow Sites 0 5.7 0 1.4 0 1.4 0 0 0 0

Stream Diversions 0 14.4 0 1.6 0 0 0 0 0 0 Water Holding and Treatment Ponds 0 10.2 0 11.7 0 7.5 0 7 0 7

Total 0 185.0 0 36.4 0 34.0 0 31.3 0 22.3

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progressive lift of the facility developing the final revegetated landform during initial construction. This design was submitted with the Lynx Ultimate Design Update amendment application in March 5, 2018.

Infrastructure that is no longer used for active mining is assessed for closure potential biannually through a corporate driven Provision Review Process; areas that will not be disturbed again during operations are prioritized for final reclamation in the internal five year closure plan and budget. Where these areas have approved closure designs these plans are implemented. In areas that required additional engineering work and permitting effort a permit level design is developed and issued for permitting consideration.

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Figure 2: Site Plan as of Dec 31, 2019

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Mining Program

Surface Development to Date

The general site plan depicting the surface development to date is provided in Figure 2 and is included in Appendix 1. The majority of the footprint of the mining operations is located within Myra Valley with additional mining infrastructure in Thelwood Valley. The direct disturbance footprint totals 185.0 ha, excluding hydro dam infrastructure, which is outside the Mine’s Act permit boundary (Permitted through BC Parks under Park Use Permit 102663). The previous estimate of mine disturbance of 198.7 ha was reassessed as part of the Habitat Loss Mitigation Plan submitted in 2019 (Wood Environment & Infrastructure, 2019).

From 1967 - 1984 tailings were deposited sub-aqueously into the south end of Buttle Lake. Since 1984 the mine has utilized a surface tailings disposal facility (TDF) for its tailings impoundment, starting with the Myra Tailings Disposal Facility (now referred to as the Old TDF), which was filled to completion in 2011. In 2008, a newly constructed Lynx TDF became the main depositional facility for tailings, replacing the Old TDF which is now at full capacity. At final design elevation, the Lynx TDF has storage capacity for approximately eight years of production at planned mining rates with a final proposed design height of approximately 60 m. The TDF has been designed to store the 1:200 Annual Exceedance Probability (AEP) event 24-hour Environmental Design Flood (EDF) of 303,000 m3, with flood waters in excess of that volume directed out of the facility through the Emergency Spillway to Myra Creek. At final elevation the facility will provide storage for approximately 1.5 Mt of pasted tailings, or approximately 7 years of surface deposition requirements.

Current Life of Mine Plan

As of December 31 2018, the Myra Falls resource estimate (measured and indicated), was 7.64 million metric tonnes. At currently anticipated mining and depletion rates, a mine life of at least eight years is indicated. This estimate would be entirely dependent on forecasted and prevailing metal prices, currency exchange rates, as well as fluctuating costs of mining and processing.

Surface Development in the Past Year

There was no surface development that resulted in new areas of disturbance in 2019.

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Construction efforts focussed on areas within the existing mine footprint, in particular the Lynx TDF lift to 365.1 MASL planned for 2019 was completed in November 2019. This work was completed using some waste rock from underground, waste rock stored in construction stockpiles located on the Old TDF and Dump 6 and repurposed waste rock from Waste Rock Dumps 2, 3 and 7. Boulders from the waste rock dumps and the quarry were crushed as required for use as fine materials as needed for bedding material and to blend with waste rock when it did not meet the material specifications for fine content. Some construction materials were trucked in from the Uplands Quarry in Campbell River for materials specific to engineering designs that could not be created or obtained on site.

Between December 2019 and January 2020 additional work was conducted to upgrade the existing berms on the Jim Mitchell Lake Road to allow the use of 30 tonne haul trucks, with a variance in place to allow for a slightly narrower road than required under the standards set out in the BC Health, Safety and Reclamation Code for Mines.

The lower portion of the Lynx 6 Ore Chute was decommissioned and dismantled in June of 2019.

Tailings in the form of Paste were deposited in the Lynx TDF in 2019 as depicted in Table 2: Quantities of Waste Rock, Tailings, Low Grade Ore, Coarse Reject and Other Mine Waste as of December 31, 2019.

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Table 3: Quantities of Waste Rock, Tailings, Low Grade Ore, Coarse Reject and Other Mine Waste as of December 31, 2019 Name of Waste Pile or Pond

Acid Generating Waste

Potentially Acid Generating Waste

Non-Acid Generating Waste

Waste Dumps 2019 Total 2019 Total 2019 Total

1 0 0 0 5,588,375 0 0 2 0 0 -30,714 1,614,686 0 0

3+4 0 0 -133,436 243,106 0 0 6 0 0 0 559,800 0 0 7 0 0 -9564 0 0 0

Construction - Stockpiles 0 0 -50,215 74,785 24,575 24,575

Lynx TDF Dam Core 0 0 211,976 2,285,085 1,090 15,190

Total 0 0 13,687 10,365,836 25,665 39,765 Tailings Ponds 0 0 0 0 0 0

Lynx TDF 0 0 145,398 2,095,179 0 0 Old TDF 0 0 0 11,592,647 0 0

Total 0 0 145,398 13,687,826 0 0

Mining and Milling Production

No active mining took place in the Lynx Zone underground in 2019. HW Zone was actively mined throughout 2019, with a total of 129,182 tonnes mined. Nyrstar started active mining in the Price Zone underground via surface access through the Price 4, 5 and 13 Portals in February, and mined throughout the remained of 2019. A total of 65,614 tonnes mined and transported by cart through the Price 13 Portal and surface hauled; ore to the mill stockpile and waste to the waste stockpile for use in the construction of the Lynx TDF dam raise. A total of 194,796 tonnes were mined in 2019, as depicted in Table 4.

The Myra Falls Mill began full operation in May, 2019. A total of 145,398 tonnes were milled in 2019, as depicted in Table 4. The EMPR Table 4 has not been included, as no specialized milling was completed in 2019. No samples were taken from the milled materials in 2019 for Acid Base Accounting.

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TABLE 4

MONTHLY MINING AND MILLING PRODUCTION AS OF DECEMBER 31, 2019

COMPANY: NYRSTAR MYRA FALLS LTD. PERMIT NO.: M-26

Use the space below to enter information for mining and milling production rates for each month of the reporting year. All quantities should be given in tonnes. Table 4: MONTHLY MINING AND MILLING PRODUCTION AS OF DECEMBER 31, 2019 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total

Mining Production (tonnes) Price Mine 0 1,223 1,819 52 1,149 7,897 8,922 5,735 7,537 13,172 11,659 6,449 65,614

Lynx Mine 0 0 0 0 0 0 0 0 0 0 0 0 0 HW Mine 3,629 934 1,898 3,762 5,102 5,995 12,038 13,741 17,238 19,037 21,119 24,689 129,182 Mining Total 3,629 2,157 3,717 3,814 6,251 13,892 20,960 19,476 24,775 32,209 32,778 31,138 194,796

Milling Production (tonnes)

Mill 0 0 0 0 10,650 25,006 7,599 24,883 21,294 20,525 28,520 25,391 145,398 Milling Total 0 0 0 0 10,650 25,006 7,599 24,883 21,294 20,525 28,520 25,391 145,398

Milling Capacity 508 tonnes

per day Include:

• All mining locations (both underground and surface, including borrow areas) • All milling locations (both on-site and off-site)

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Waste Rock Dumps

In 2019, 34,813 m3 of PAG waste was brought to surface and placed into construction stockpiles for use in the Lynx TDF Dam raise. 25,641 m3

of non-PAG waste was brought to surface and stockpiled in the clean rock quarry for use in future reclamation works or any construction not related to the Lynx TDF Dam raise. Waste was removed from dumps 2 and 3 as construction materials for the Lynx TDF lift in a manner that is consistent with the reclamation plan for these facilities. A total of 30,714 m3 were removed from Dump 2 in 2018, and 143,000 m3 was removed from Dump 3.

Growth Medium

There is one stockpile of growth medium onsite at Myra Falls. This material was stripped from the CRAB (Core Rack Area Borrow) area during development of the clean fill borrow source. No movement of material to or from this stockpile occurred in 2019 as depicted in Table 5. A single sample was collected from the existing soil stockpile to characterize the soil. The results are included in Appendix 2, “Nyrstar Myra Falls Mine Topsoil Management Plan”, developed by Wood in December, 2018.

Table 5: (EMPR Table 5) Quantities of Soil & Overburden Salvaged & Stockpiled for Reclamation Use as of December 31, 2018

Area Salvaged (Location and Area in ha)

Salvage Volumes to Stockpile Locations (m3)

Stockpile 1 (Quarry)

Total Salvage Volumes (m3)

# of Samples for Suitability

CRAB 4.7 ha 5239 m³ 5239 m³ 1

Totals 5239 m³ 5239 m³ 1

Surface Development Projected Over the Next Five Years

Mining at Myra Falls is confined to underground operations. Surface development is limited to waste management such as tailings facility construction and infrastructure upgrades, and the development of clean fill borrow sites.

Annual berm raises of the Lynx TDF will continue over the life of the facility (estimated eight years). Over the next five years, it is anticipated that the Lynx Berm foundation will be prepared to the final footprint of the facility, and the toe ditch, toe drain, and springs drain will be constructed to allow the facility to be lifted (Amec Foster Wheeler, March

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2017 a). Incremental lifts will be constructed each operating year in equalized annual volumes utilizing both waste directly from underground and excavated from the Waste Rock Dumps 2, 3 and 6 under the stabilization plan for Closure of those facilities (Amec Foster Wheeler, March 2017 b). Annual lifts will be constructed to the minimum operationally required elevation, with the remaining materials utilized in constructing the outer shell including the final closure cover and related underdrains as depicted in the Lynx Berm Face Cover Design (Amec Foster Wheeler, December 2016 a).

It is anticipated that each operating year will have a corresponding dam construction schedule incorporating between 170,000 m3 and 280,000 m3 of waste rock utilized, depending on the mining requirements underground. The Lynx Berm will act as the active waste rock dump during the majority of the year. Wood has provided specifications on material placement outside of the normal construction window that will allow NMF to maximize the productivity of these efforts in off-season conditions.

An application to expand the on-site Clean Quarry was applied for in 2018 and once approved will result in incremental increases in the overall footprint of the site. This expansion will facilitate the clean-fill and drainage rock components of the Old TDF Closure Cover as well as the Lynx TDF Closure Spillway, Lynx Spring Drain, and Lynx Closure Cover. NMF will reclaim these areas to the maximum extent possible annually, as described in the Environmental Protection Program section.

Environmental Management System

The objective of the Nyrstar Environmental Management System (EMS) is to provide a manual for employees, contractors and other stakeholders; establish a ‘road-map’ for the site’s environmental documents; and to facilitate best management practices in environmental activities. The EMS is currently under review and redevelopment currently as required by the Mine’s Act permits M-26 and will be submitted to the EMPR upon completion.

As members of the Mining Association of Canada (MAC), Nyrstar Myra Falls has focused on continued operational and environmental improvements that incorporate Towards Sustainable Mining (TSM) principles and initiatives. The EMS is also being guided by ISO 14001 requirements, and so structured to align environmental policy with planning, implementation and operation, checking and corrective actions, and management reviews towards continued operational and environmental improvements.

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ML/ARD Characterization and Management

In 2019, ML/ARD sampling was carried out as per the ML/ARD plan (included as appendix 3). A total of eighty (80) samples were collected and analyzed for acid base accounting (ABA) and near-total metal concentration. 15 run-of-mine waste rock samples were taken from the Price mine and HW Mine, five (5) from the Phillips Reach Decline Extension development rock, fourteen (14) from WRD 3, four (4) from WRD #2, thirty one (31) from the Lynx TDF Embankment Berm, and seven (7) from the mill area.

A review of the 2019 ML/ARD sampling results was performed by RGC (Robertson GeoConsultants, 2020). Run-of-mine waste, WRDs 2 and 3, Lynx TDF embankment berm, and Mill Area were classified as PAG, while the development rock from Phillips Reach and Camp Area were classified as non-sulphidic or low-sulphide Non-PAG. In general the findings of the review were consistent with the findings of the 2016 assessment and characterization of tailings and waste rock geochemistry carried out by RGC (Robertson GeoConsultants Inc., April 2016). Full findings of the review are available as Appendix 7.

Surface Water Quality and Quantity

Surface water quality monitoring is conducted in accordance with Ministry of Environment Permit (BC ENV) PE-06858, as well as, Environment Canada’s Metal and Diamond Mine Effluent Regulations (MDMER).

Metal and Diamond Mines Effluent Regulations (MDMER)

MDMER sampling consists of two major components: Effluent Monitoring and Environmental Effects Monitoring, each of which involves multiple monitoring programs. The following describes the monitoring requirements carried out at Nyrstar Myra Falls in accordance with the MDMER with site specific summaries provided where applicable.

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Physical and Chemical Parameter Monitoring:

1. Weekly: Effluent is monitored for pH, flow, and total concentrations of arsenic, copper, cyanide1, lead, nickel, zinc, total suspended solids and radium-2262.

2. Quarterly: Additional chemical parameters tested include hardness, alkalinity, and total concentrations of aluminum, cadmium, iron, mercury, molybdenum, ammonia, nitrate, selenium, temperature, total and dissolved organic carbon, phosphorus, chloride, fluoride, Sulphate, dissolved oxygen and electrical conductivity.

The receiving environment upstream and downstream of the effluent discharge point is monitored for the same list of deleterious substances as the effluent on a quarterly basis. Flow in Myra Creek is monitored continuously by two monitoring stations, a pressure transducer at the “car bridge” and a radar sensor downstream of the effluent across from the former backfill plant.

Biological Monitoring Studies:

1. Quarterly: The acute toxicity of effluent is tested using juvenile rainbow trout and Daphnia magna LC50 tests. All quarterly 2019 rainbow trout 96-hour LC50 test results were >100% vol./vol. survival rate for rainbow trout.

2. Semi-Annual Sub-lethal (chronic) toxicity effects of effluent on a fish, invertebrate, aquatic plant and algal species are tested semi-annually with one test typically in May and another in November. The results are included as Appendix 4.

In May 2019, as in previous years, stimulatory effects were observed for P. subcapitata (micro alga) in the cell yield for in test concentrations 6 – 95.2% (v/v). No adverse effects were observed for dry weight of L. minor (pond weed), however inhibitory effects

1 Cyanide is not used at NMF and is therefore not required to be monitored.

2 Monitoring results for Radium 226 below method detection limit, frequency reduced to quarterly.

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were observed for frond count with IC25 and IC 50 of 83.2% and 87% v/v respectively. C. dubia (water flea) exhibited no adverse effects observed on survival or reproduction (Nautilus Environmental, 2018). No adverse impacts were observed to the embryo viability of O. mykiss (rainbow trout). (Nautilus Environmental, 2018).

The second sub-lethal testing was performed over 2 sampling events (October 28 and November 13, 2020). C. dubnia survival and reproduction and rainbow trout embryo viability were tested from the October 28 sampling, and L. minor growth inhibition and P. subcapitata growth inhibition were tested from the November 13 sampling. No adverse effects were observed for C. dubnia survival, embryo viability of rainbow trout, or cell yield of P. subcapitata. Reduction in C. dubnia reproduction (IC 25 and IC50 of 55.1% and >100%, respectively) were observed, as well as adverse effects on L. minor in frond count (IC 25 and IC50 of 31.0 and 73.3%, respectively) and dry weight (IC25 and IC50 of 30.8 and >97%, respectively).

3. Three year cycle: Monitoring of the ecosystem health is completed in a three year cycle. Myra Falls completed year 2 of Cycle 6 in 2019 which included the following: field work as described in the Cycle 6 Study Design. In 2020 the analysis and reporting for cycle six will be performed.

Water quality and toxicity results from MDMER monitoring are reported online using Environment Canada’s Mine Effluent Reporting System (MERS) within the Environment Canada Single Window Information Manager (SWIM) data platform. (https://ec.ss.ec.gc.ca/en/cs). Biological monitoring studies are submitted as full reports to the MDMER Program Scientists at the Environment Canada Office in Vancouver.

BC Ministry of Environment Water Quality Monitoring (Permit PE-06858)

The provincial effluent permit PE-06858 is issued under the provisions of the Environmental Protection Act. Along with effluent monitoring, surface and ground water quality is monitored at upstream and downstream sites to assess impacts of mining activities on the receiving environment. Further detail regarding water quality monitoring is provided in Appendix 5 Nyrstar Myra Falls 2019 Surface Water and Groundwater Monitoring Report2019, compiled by Robertson GeoConsultants (Robertson GeoConsultants, 2020).

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Flow Monitoring

Effluent volume reporting to Myra Creek is monitored via a 30” Parshall Flume equipped with continuous ultrasonic flow measurement.

Figure 3 depicts daily flow volumes (m3/day) for Myra Ponds effluent and Myra Creek.

Myra Creek flow is monitored just upstream of the Old TDF footprint with a pressure transducer and data logger system. The system logs creek-stage measurements at 15 minute intervals. Stage measurements are then converted to flow using a stage-discharge curve calculation. During 2019 the logger stopped recording in January and wasn’t able to be recovered. The system was replaced in September 2019 and a new hydrometric monitoring station was installed based on recommendation by Myra Falls Hydrological consultants due to changes to Myra Creek that have occurred since the initial development of the curve. The two stations will be monitored together for development of the new stage curve

Flow through the water treatment system is generally associated with precipitation and therefore shows seasonal variability.

Figure 3 depicts the flow curves for Myra Creek and the effluent from the Superpond Lime Treatment System. The effluent discharged to Myra Creek makes up an average of 15% of the total flow in Myra Creek (using data from Q4 only), ranging from 2% to 30% of the total Myra Creek flow.

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Figure 3: Myra Creek and Effluent Flows with Precipitation

Groundwater Quality and Quantity

Groundwater sampling mandated by Permit M-26 and PE-06858 is prescribed to assess potential contaminants from groundwater under Tailing Disposal Facilities (TDFs) impacting Myra Creek, and is restricted geographically in providing site-wide groundwater data used to update the site-wide geochemical model as prepared by Robertson GeoConsultants (December 2016), and most recently updated in 2018 and calibrated with results from 2012 through October 2017 (Robertson GeoConsultants, 2018). This model will be reviewed and updated at least every five years to ensure it is up to date and the results will inform mine waste management, water treatment strategies, and closure planning. Monitoring is divided into two major programs, groundwater well sampling and seepage sampling. Further detail regarding water quality monitoring is provided in Appendix 5 - Nyrstar Myra Falls 2019 Surface Water and Groundwater Monitoring Report, prepared by Robertson GeoConsultants (RGC) (Robertson GeoConsultants, 2020).

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Seep Monitoring

Seeps are monitored when flowing, generally associated with precipitation events larger than 60 mm/day or 80 mm over two days. Flow rates are estimated and water is sampled for quality if there is sufficient flow. Further detail regarding results of the seep monitoring is provided in Appendix 5. Water Quality Prediction, Mitigation and Treatment

The water treatment system at Nyrstar Myra Falls collects and treats contaminated ground water, surface runoff, mill effluent, tailings disposal facilities supernatant, underground mine water and sewage treatment plant effluent. Contact and process water is directed to the reaction pond, (Superpond) for treatment with the addition of lime slurry (Ca(OH)2) to elevate pH levels to approximately 10.5 allowing contaminants to precipitate as insoluble metal hydroxide sludge.

The Superpond functions as a primary settling pond before effluent is discharged to a series of six polishing ponds (Myra Ponds) for further gravitational settling. All Superpond flows are discharged to Myra 1 and are then decanted through the remaining settling ponds. With the exception of Myra 3, which only decants to Myra Out, there are two potential discharge points for each settling pond. By adding or removing check boards, decant outflows can be increased, decreased, or isolated completely in response to changing operational or environmental circumstances. For example, under normal operations and moderate flows, water can be directed through the longest treatment route, pond levels can be managed or ponds isolated during maintenance programs, or flow capacities increased in response to heavy or sustained precipitation. Figure 4 shows potential flow paths of the Myra Ponds treatment system with the preferred path during normal operations indicated by blue arrows. Before release to Myra Creek, effluent is automatically treated at Myra Out with CO2 injection to bring pH levels down to approximately 8.5 and within permitted levels.

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Figure 4: Flow Regime through Myra Polishing Ponds

Ponds must be regularly cleaned out or dredged of solids to maintain capacity for effective treatment and settling. The Superpond is equipped with an automated traversing barge and pump system which pumps sediment laden water to the active Tailings Disposal Facility (Lynx TDF) thereby decreasing the amount of sludge build up in the Superpond and operating to maintain treatment capacity and residence time. Sludge from the Myra Polishing Ponds is removed either via a floating dredge pump or manually using a long-reach back-hoe and haul trucks; this material is also placed into the Lynx TDF. There are plans to install a dedicated traversing dredge and pump system into the polishing ponds that can be transferred between ponds in order to remove solids as needed. This system is anticipated to be installed by end of Q3 2020.

Water Management

As Myra Falls is located in a temperate rainforest, effective water management is paramount; groundwater and surface runoff volumes are subject to abrupt changes in response to precipitation and melt events. Precipitation at the site can vary drastically, ranging from approximately 1,500 to 3,500 mm annually (Figure 5).

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Figure 5: Annual Precipitation 20193

The intensity and duration of rain events play a major role in the ability of the water treatment system to adequately manage the initial surge of runoff. Furthermore, anticipation of heavy rains and the implementation of protocols to mitigate adverse effects is an important component of water management. There have been a number of events in recent years that have tested the site’s ability to manage high water volumes and have forced NMF to assess its overall water management strategy. As such, key upgrades to water management infrastructures have been implemented to improve the delivery of contact water to the treatment system.

3 *YYYY – This notation indicates that some of the data was lost for the site weather station during that year and the data has been patched by using the average precipitation for that month from the existing record.

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Myra Falls has three major clean water diversion ditches diverting water from upslope areas to Arnica Creek, Cascade Creek and Myra Creek.

Arnica Diversion Ditch

The Arnica Diversion Ditch (ADD) captures three small streams, two of which are ephemeral. This ditch is directed to Arnica Creek and diverts water around the Lynx Mine, the Upper Lynx Open Pit, WRD4, and WRD2. It is upslope of the Upper Lynx Diversion Ditch.

Lynx Diversion System

The Upper Lynx Diversion Ditch (ULDD) captures three small streams, one of which is ephemeral. It diverts water from the Upper Lynx Open Pit, Lynx Mine, WRD2, WRD3 and the Lynx TDF. This ditch flows into the Cascade Creek.

Lower Lynx Diversion Ditch (LLDD) routes Cascade Creek and several small ephemeral springs around the Old TDF and conveys this flow to Myra Creek. The LLDD was upgraded in 2015 and 2016 to convey the updated Inflow Design Flood (IDF) for the Old TDF.

There are two creeks visible upslope of the LLDD that exhibit significant flow during precipitation and melt events. These creeks enter permeable talus rockslides mid-slope (Robertson GeoConsultants Inc., July 2016) and are not directly captured in the diversion ditch and are understood to recharge the shallow aquifer below the Old TDF under most flow conditions. Under high flow conditions (rain events with greater than 90 mm/24 hours) the volume of water exceeds the capacity of the groundwater aquifer to recharge, and flows from the Diversion Ditch Spring Drain (DDSD) and the underdrains. Monitoring results to date indicate that these drains are functioning as intended and the water quality has significantly improved.

There is a Debris Flow net installed in the upper reach of the LLDD, just downstream of the Cascade Creek sized to the current potential debris inventory performed by Amec Foster Wheeler (now known as Wood) in 2015 and 2016 (Amec Foster Wheeler, August 2016). This structure is intended to capture large woody debris and rocks upstream of the concrete lined portion of the channel to protect the liner. The debris catchment also acts to prevent blockages in the ditch adjacent to the TDF, reducing the risk of a blockage that would cause the flow to be routed onto the paste stack in a flood event.

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Old TDF and Amalgamated Paste Area (APA) Decant System

The Old TDF and APA are dewatered passively through a system of concrete and HDPE pipe decants and surface ditches that drain into the newly constructed Surge-pond. The facility is able to rapidly shed water in a passive fashion, with the 1:1000 AEP flood being stored in the surge pond and directed to treatment. The facility will shed the probable maximum flood (PMF) in a controlled fashion, with flows over and above 1:1000 AEP being directed through one of two emergency spillways, the APA Spillway, or the Surge pond Spillway to Myra Creek.

Lynx TDF, Waste Rock Dumps and Lynx Mine

Contact water emanating from the areas upslope of the Lynx TDF and downslope of the ADD and ULDD reports to the Lynx TDF. This water is pumped from the Lynx TDF to the Superpond for treatment. With the lift of the Lynx TDF completed in 2017, the facility is able to store the 1:200 probability 24 hour annual return event; this is a volume of 303,000m3 of water, as it is assumed in the models that the clean water diversion ditches will fail during such an event.

Lynx Seepage Interception System

Downstream sample concentrations are largely driven by groundwater influences, in particular from the Lynx TDF Reach (Robertson GeoConsultants Inc., July 2014). To mitigate the effect of contaminated ground water on Myra Creek, as per designs and recommendations from a hydrogeologist at Robertson GeoConsultants, Myra Falls has installed a Seepage Interception System (SIS) downgradient of the Lynx TDF designed to recover impacted groundwater from the Myra Valley aquifer and send it to treatment. The Lynx SIS consists of two phases, deep and shallow. Phase I (deep) consists of a fence of three pump back wells which are predicted to provide measured improvement in water quality in the receiving environment as more contaminated ground water is captured, the water table is lowered, and contaminated groundwater migration is limited (Robertson GeoConsultants Inc., December 2016). Activation of the Lynx SIS pumps was completed in September of 2017 and the system has been operational from that time. A performance assessment of the system by RGC was carried out and reported in 2018, with key findings that the SIS wells are working as intended, with approximately 15 tonnes of zinc recovered during the first six months of operation (Robertson GeoConsultants, 2018). A longer term performance assessment is still underway, and will be reported upon annually in Appendix 5 (Robertson GeoConsultants, 2020)

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Lynx Shallow Seepage Interception System

A change to the seepage area between the Car Bridge and the Old TDF, downslope of the Superpond, was identified in early 2018. Seeps previously noted in the upper bank reporting to 25 Sump had not expressed, but a new area of seepage directly into Myra Creek had developed. The area was identified when a toxicity sample was collected for an unrelated bypass event, and indicated impacts that did not correlate with the effluent that had bypassed the system. Further investigation indicated that as many as ten (10) small, discrete seeps had developed on the bank of Myra Creek in this area; poor quality, low flow seeps detectable within a meter of the bank with a pH meter were emanating from the bank at or just below creek elevation. This new seepage area was reported to the BC Ministry of Environment and Climate Change Strategy (BC ENV), as well as EMPR and Environment Canada when it was identified. Under direction of the BC ENV, Nyrstar worked with Robertson GeoConsultants and Wood Environment & Infrastructure Solutions to develop a mitigation strategy to prevent further impacts to Myra Creek. This plan included a reduction of standing water upslope of the identified seepage area, and a trial dewatering system to determine if it was possible to reduce the seepage. A series of five additional pumping wells were installed in 2018 south of the Superpond referred to as phase II of the Lynx Seepage Interception System. The drilling and installation of the wells was supervised by a representative of each consulting company. Nyrstar commissioned Canadian Dewatering to set up a trial vacuum dewatering system that was operated from May through June. The groundwater model for the area was updated based on the trial, and recommendations were provided for a longer term mitigation of the seepage area in a report on the outcomes of the trail provided to the BC ENV as part of the follow-up reporting (Robertson GeoConsultants, 2018). The dewatering well net was effective at reducing the flows (Robertson GeoConsultants, 2018) and following the initial test Nyrstar has opted to install four submersible pumps in the wells to draw down the local water table to a level that prevents recharge to the creek. The system was installed in February of 2019 and has run continuously since, with the exception of maintenance events and repairs; the submersible pumps are triggered by water elevation, and reclaimed water will be directed to the Superpond Lime Addition System for treatment before being released to

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Myra Creek via the effluent system. Monitoring of the system is ongoing, and will be reported on in subsequent reports and updates of the Geochemical Model for the site Contact Water Ditches.

Contact water is directed to the water treatment system through a series of lined and unlined surface ditches, sumps and pipes. Efforts have been made to decrease the water losses to groundwater through lining and piping older unlined ditches.

Flows emanating from the Myra Portals from Myra 9, 10, and 11 levels are piped directly to the Myra Surface Sump that pumps this water to Superpond for treatment. The old surface ditch was rerouted to collect the clean rainwater and direct it into Myra 1 Polishing Pond for settling of suspended solids prior to release with the water treated through the Superpond system to Myra Creek.

Erosion and Sediment Control

Erosion prevention works completed in 2019 focussed on maintenance of operational sediment traps on the waste rock dumps and adjacent to construction areas and erosion prevention in the Old Emergency Tailings Area (ETA). Work continued to transition from open, unlined ditches to piping contact water to treatment.

Ditches on the waste rock dumps and along construction access roads were maintained through periodic removal of debris and sediment build-up to restore the channels to intended functional capacity. Coarse rock check dams were maintained in the ditches on the “A-Ramp” and “Paste-plant Hill” on WRD 1, and these were checked daily by the Surface Supervisor with sediment build-up dug out as required.

Soil and Salvage Stockpiling

There was no significant addition to or removal of stockpiled topsoil at Myra Falls during 2019.

Vegetation Management

Vegetation Management at Myra Falls consists of two major components; monitoring of regenerating vegetation (planted or natural ingress) following remediation works and management of invasive species (Integral Ecology Group, 2018). These programs are informed by recommendations provided by Integral Ecology Group (IEG), who perform periodic site visits to assess the success of the revegetation efforts to date. The last site visit by IEG was performed in 2019 and noted that many of the observations made

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during the 2019 site visit were similar to those made in the 2018 visit (Integral Ecology Group, 2020). Monitoring results as reported were mixed, with results of 2016 hydro-seed in the Core Rack Area Borrow (CRAB) testing largely unsuccessful, but the natural ingress of vegetation on the previously reclaimed Old TDF continuing to progress along the trajectory toward the final climax ecosystem. It was noted by IEG that the 2018 and 2019 surveys were reconnaissance surveys, and a full assessment of the sample plots on the old TDF is expected to take place in 2020 (Integral Ecology Group, 2020). Invasive species were noted in several locations in the site assessment; hand-pulling, mowing and other manual controls will be implemented to control the invasive species.

Similarly to the 2018 assessment, several areas with invasive species were identified in 2019. Canada Thistle, Bull Thistle, and Himalayan Blackberry were noted in several areas; hand-pulling, mowing and other manual controls will be implemented to control the invasive species. These areas will be monitored for recurrence over the next few years to maintain the controls (Integral Ecology Group, 2019).

Wildlife Protection

Wildlife and habitat assessments, including breeding bird nesting surveys, are carried out before any new surface development occurs. Nyrstar employs an anecdotal wildlife sightings notification system, largely focused on sightings of bears and cougars, to warn employees of potential hazards and disseminate information regarding appropriate actions to take when encountering wildlife.

An introductory general Wildlife Habitat and specific Bat Habitat Survey was conducted by Stantec in 2018 as part of the work completed in support of the Wildlife Management Plan (Stantec, 2019).

Archaeological Resources

A Site wide archaeological site potential assessment was performed in 2019 for all Nyrstar mining leases and Crown grants by Baseline Archaeological Services Ltd (Baseline). The recommendation of the assessment was that any developments in Mining Leases 201323 or 1069356 be reviewed by an archaeologist, while all other grants and leases are of low archaeological potential. No new archaeological resources were identified in 2019 (Baseline Archaeological Services Ltd., 2019).

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RECLAMATION PROGRAM

The Reclamation Plan for Myra Falls (Robertson GeoConsultants Inc., July 2014) was submitted to the Ministry of Energy and Mines July 31, 2014. An addendum report was submitted in December 2016 that included permit level designs for the Old TDF Closure Cover and the Lynx Berm Closure Cover to allow construction of these covers in the near term. (Nyrstar Myra Falls, December 2016).

Waste rock was removed from Waste Rock Dumps 2 and 3 however these areas will require more work before they will be considered to be the final contours for reclamation and can be slated for topsoil placement and revegetation. This work will be undertaken over several years, and final completion of the work is estimated to be 2023.

End Land-use

Upon final closure, Strathcona Westmin Park is slated to be returned to Class A Park status as discussed above. Areas that cannot be reclaimed to wilderness will be made safe for the public and interpretive information will be provided on the history of the mining activities in the valley, in keeping with the stated intent of the 2001 addendum to the Strathcona Park Master Plan Section 5.1.2 that allows mining infrastructure to remain in situ if no risk to public safety or environmental hazards exist (BC Parks Strathcona District, 2001).

Land Capability

As is common for many long-standing mine sites, information on base-line land capability and biodiversity are limited for pre-mining conditions at Myra Falls, so a definitive comparison for current or final closure to pre-existing conditions is not practical at this time. Nyrstar, in conjunction with consultants has developed a pre-mining habitat assessment (Wood Environment and Infrastructure, 2019) which includes land-capability, and habitat loss mitigation plan (Wood Environment & Infrastructure, 2019) , which address land-capacity and submitted these documents to EMPR.

The nature of the soils and till available for reclamation at Myra Falls and the expected landforms will result in closure moisture regime ranging from very xeric (south facing steep slopes) to mesic, with low nutrient values (Integral Ecology Group, July 2014). It is expected that the revegetation efforts should result in a primary closed crown cover of Red Alder approximately 20 years following planting; with a secondary growth of native conifers becoming established after 60 – 80 years, depending on aspect and

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proximately to natural propagule sources (Integral Ecology Group, July 2014). Based on monitoring results on previously planted areas, soil development and natural ingress of native species is expected to develop toward a system that will support climax vegetation, barring unforeseen natural disturbances such as fire in the future (Integral Ecology Group, March 2016), (Integral Ecology Group, July 2014).

Long-Term Stability

Nyrstar Myra Falls has been working with Wood to determine areas with risk of geotechnical instability and develop mitigation or stabilization plans as required. Waste rock dumps 2, and 3 were targeted for remedial works to prevent seismic instabilities for final closure. The stabilization of WRD2 and WRD3 have been treated separately (Amec Foster Wheeler, March 2016).

Active reclamation activities for long-term stability completed in 2018 were limited to the removal of excess waste in Waste Rock Dumps 2 and 3. A total of 30,714 m3 were removed from Dump 2, and 143,000 m3 were removed from Dump 3 in 2019.

Revegetation

The goal of the Myra Falls revegetation program is to create a sustainable vegetation cover reflective of the surrounding coastal western hemlock ecosystem. To promote this ecosystem development the site has adopted a natural ecosystem succession approach, in which early succession species are used for initial revegetation efforts. Following initial ground cover establishment, NMF may opt to tree plant using seedlings appropriate to the area if natural ingress of native plants is not occurring as expected. This decision will be made on a case by case basis for each area under consideration. Areas close to tracts of natural forested lands have ample sources of propagules and may not need the same level of intervention as areas that are further away from natural seed sources. Professionals such as Integral Ecology Group will be consulted when developing each site specific revegetation prescription to ensure this effort is managed appropriately.

No active revegetation work was undertaken in 2019, however an assessment of areas previously seeded was undertaken to determine the success of the hydro-seeding completed on the CRAB (2016), the natural revegetation of the native soils exposed by the removal of waste rock from WRD 2 (2017), and planting on the old TDF Seismic Upgrade Berm (2008 and 2010). The seeding campaign was not successful in the

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CRAB, and alternative revegetation methods will need to be employed in the area for final reclamation.

Older revegetation efforts focused on establishing pioneering woody species such as red alder on the Old TDF Seismic Berm were also assessed. The area planted in 2008 are growing well, while the area planted in 2010 is developing at a slower pace and may benefit from targeted fertilization or infill hydroseeding (Integral Ecology Group, 2020).

No revegetation activities have taken place on the WRD 2 areas, but during the inspection, sparse vegetation was found to be establishing on the exposed native ground, approximately 5% ground cover. Species found include fireweed, miner’s lettuce, thimbleberry and pearly everlasting (Integral Ecology Group, 2020). Presence of bull thistle and Himalayan blackberry was also noted during inspection (Integral Ecology Group, 2020).

Table 6: Hydroseed Blend Used 2016

Figure 6: CRAB Following Hydroseed Application with Native Seeds October 12, 2016

% seeds / g Grams purchased # Individual Seedsdull Oregon‐grape Mahonia nervosa 0.13% 65 500 32,500 red huckleberry Vaccinium parvifolium 2.22% 5,400 105 567,000 salal Gaultheria shallon 20.90% 7,100 751 5,332,100 Sitka mountain ash Sorbus sitchensis 0.02% 308 20 6,160 snowberry Symphoricarpos albus 0.01% 178 20 3,560 pearly everlasting Anaphalis margaratacea 49.74% 17,621 720 12,687,120 fireweed Chamerion angustifolium 7.84% 20,000 100 2,000,000 goatsbeard Aruncus dioicus 17.29% 9,524 463 4,409,612 upland sedges Carex spp. Carex macloriana? 1.67% 1,500 284 426,000 vanilla leaf Achlys triphylla 0.17% 112 388 43,456

Shru

bsHe

rbs

Species

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Figure 7: CRAB April 2020

Growth Medium

No growth medium was added or removed from stockpiles in 2018. Additional work will be required to establish vegetation on the stockpile as the hydroseeding was not successful.

Landforms

Work on Waste Rock Dump 2 was designed to return the area to original ground as much as possible, following removal of the overlaying waste rock.

Works planned for the next five years will involve the removal or recontouring of the waste rock dumps to a stable configuration. Materials removed from the waste rock dumps will be used in the construction of the Lynx TDF.

Waste Dump Reclamation

In 2019, 30,714 m3 of waste was removed from Waste Rock Dump 2 and 143,000 m3 was removed from Waste Dump 3, reducing the volume of materials on these facilities required to be removed to achieve the final configuration of the facilities. No final recontouring was achieved in these areas in 2019, and additional works will be required to achieve the final landforms. The photos on the following page illustrate the changes to the waste rock dumps with the removal of the waste for use in construction.

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Figure 9: Dump 2 from camp 2016 prior to recontouring

Figure 11: Dump 2 from camp March 2020 after 3 years of recontouring

Figure 10: Dump 2 from Phillips Reach 2016 prior to recontouring

Figure 13: Dump 2 from Phillips Reach March 2020

Figure 8: Alder Reach March 2018 - 1 season vegetation growth

Figure 12: Alder Reach March 2020 - 3 seasons of vegetation growth

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Watercourse Reclamation

No watercourse reclamation was conducted in 2019. Planning for reclamation along the Arnica and Myra creek banks has started and will continue to be developed as the next five year reclamation plan progresses for submission in 2021.

Open Pit Reclamation

Planning for reclamation to be conducted on the Upper Lynx Open Pit is underway and is slated to start in 2020 with full completion in 2021.

Waste was removed from Waste Rock Dump 3 which is located in the Lower Lynx Open Pit, and work will continue for several years prior to the completion of this project. The highwall was machine scaled as it was exposed and was assessed by an engineer from Onsite Engineering as the waste rock dump was removed (Onsite Engineering, 2020). A stability assessment of the highwall was completed by a Professional engineer at the end of construction with no observed changes and no significant rock fall evidence along the catch berm at the toe of the dump. Any recommendations for long-term stabilization will be implemented as required.

Tailings Storage Facilities / Impoundment Reclamation

No active reclamation work was completed on the tailings disposal facilities in 2019.

Road Reclamation

No active reclamation of roadways was conducted in 2019.

Structures and Equipment

No active removal of buildings or structures was implemented in 2019.

Securing Openings

Mine openings are secured with gates when not in active use.

Areas on the mine-site are controlled with barricades and signage. Signs are placed at points on the public road indicating restricted access to prevent inadvertent access by park users. Access to the site is controlled through a security gate and electronic rostering system.

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Events Outside of Normal Operational Parameters

There were ten environmental events communicated to regulatory authorities in 2019 as detailed in Table 6.

Follow-up reports detailing the root cause and mitigation efforts were submitted to the Ministry of Environment and Environment Canada as appropriate. Other agencies such as the Ministry of Energy and Mines, the Vancouver Island Health Authority and BC Parks are also notified of these events.

Table 7: Summary of Events Outside of Normal Operational Parameters Incident

Date Incident Description Permit or Regulation

February 3-5 Regulatory samples not collected – autosampler freezing PE-06858

February 27

Effluent discharge - pH out of compliance (within permit limits) MDMER

March 11 Freezing temperatures led to overtop of HW Runoff Sump and release to Webster Creek

MDMER / PE-06858

June 5-11 Regulatory samples not collected – Autosampler failure PE-06858

May 29 Exceedance of BOD limit at Myra Sewage Treatment Plant PE-06858

October 30 Regulatory sample not collected (Weekly Grab - Lead) PE-06858 November

13 Missed parameter on Effluent Characterization MDMER

December 18

Exceedance of regulatory limits (Zinc, Total Suspended Solids)

MDMER / PE-06858

December 31

Exceedance of monthly average Total Suspended Solids limit – 16.16 mg/L average (above 15.00 mg/L average limit) MDMER

February –October 8

Myra Creek Logger did not collect data between Feb and Oct 8 PE-06858

Disposal of Chemicals and Reagents

Chemical disposal is controlled by the onsite warehouse. Warehouse staff is TDG and WHMIS trained; all chemicals for disposal are sent to an accredited disposal site by a licenced transport company.

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Reclamation Research

In 2019 several studies were undertaken under the umbrella of reclamation, most of which were mentioned in previous sections on geotechnical and geochemical updates. Research and field studies completed in 2017 have continued to provide a solid framework of geotechnical and geochemical understanding of the site to allow future works to be completed with confidence that they will be stable on the long term. In 2019, Nyrstar submitted a reclamation research program including a knowledge gap analysis, post closure mapping, reclamation methodology evaluation, and monitoring program (Stantec + Integral Ecology Group, 2019).

NMF monitored the hydroseeding completed in 2016, and a memorandum discussing the result is provided as Appendix 6. Preliminary planning for field trials with other planting and revegetation are currently being considered, as are trials for cover materials for the TDF’s. These trials will be further detailed in future reports.

5 Year Reclamation Plan

Myra Falls submitted an addendum to the Interim Site Wide Reclamation Plan (Robertson GeoConsultants Inc., July 2014) in December of 2016. This plan detailed the reclamation activities to occur in the next three years. Works will be focus on the Progressive Closure of infrastructure no longer required for active mining such as the Old TDF, the Lynx TDF and the Lynx Waste Rock Dumps.

The next five year mine plan is under development and is scheduled for submission to the EMPR in January 2021.

Reclamation Cost Assessment

The 2019 reclamation cost assessment will be submitted as a separate confidential assessment.

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