Mount Polley Mining Corporation - British Columbia · PDF fileIn 2016, Mount Polley Mining Corporation (MPMC) Operations mined 6,199,473 tonnes of ore and ... QP Qualified Professional

Mount Polley Mining Corporation

an Imperial Metals company Box 12 Likely, BC V0L 1N0 T 250.790.2215 F 250.790.2613

2016 Annual Environmental and Reclamation Report for the Mount Polley Mine

Submitted to:

The BC Ministry of Energy and Mines (Mines Act Permit M-200)

And The BC Ministry of Environment

Permit 11678

Prepared by:

Mount Polley Mining Corporation Environmental Department

Box 12, Likely BC V0L 1N0

(250) 790-2215

Mine Manager: Dale Reimer

Environmental Supervisor: Colleen Hughes

March 31, 2017

Mount Polley Mining Corporation Annual Environmental & Reclamation Report 2016

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EXECUTIVE SUMMARY

In 2016, Mount Polley Mining Corporation (MPMC) Operations mined 6,199,473 tonnes of ore and

7,907,779 tonnes of waste rock from the Cariboo Pit. Approximately 19% of the waste mined was

potentially acid generating, and was transported to the Temporary PAG Stockpile. 4,980,215 tonnes of

tailings were moved to Springer Pit, and 3,420,811 tonnes of tailings were moved to the Tailings Storage

Facility. 1.66 hectares were disturbed with the expansion of the Cariboo Ore stockpile.

This report documents the reclamation program and the Comprehensive Environmental Monitoring Plan

at Mount Polley in 2016. The CEMP focuses on monitoring for all potential mine impacts and this report

documents the findings of the monitoring.

In 2016, one release of mine-affected water were reported to Emergency Management BC.

Permit non-compliances that occurred were reported to the Director as regulated.

As permitted by the 2015 amendment to MoE Permit 11678, the Water Treatment Plant and discharge to

Hazeltine Creek operated from January 1, 2016 to December 31, 2016 and discharged a total of 6,904,388

m3 of water. Reporting to Environment Canada under the Federal Metal Mining Effluent Regulations

continued accordingly.


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TABLE OF CONTENTS

List of Tables ........................................................................................................................................................................................... v List of Figures ........................................................................................................................................................................................ vi Appendices ........................................................................................................................................................................................... vii Abbreviations and Acronyms ........................................................................................................................................................ viii 1 Introduction ................................................................................................................................................................................... 1

1.1 Objectives ............................................................................................................................................................................ 1 1.2 First Nations and Stakeholders ................................................................................................................................... 5 1.3 Qualified Professionals .................................................................................................................................................. 7

2 Mount Polley Mine Project Overview .................................................................................................................................. 9 2.1 Project History ................................................................................................................................................................... 9 2.2 Current Project Status ................................................................................................................................................. 11 2.3 Environment .................................................................................................................................................................... 12

3 Environmental Management ............................................................................................................................................... 14 3.1 Water Management ..................................................................................................................................................... 14 3.2 Sediment and Erosion Control ................................................................................................................................. 20 3.3 Invasive Plant Management ...................................................................................................................................... 21 3.4 Waste Management ..................................................................................................................................................... 22 3.5 Incidents ........................................................................................................................................................................... 23

4 Data Quality Assurance/Quality Control ......................................................................................................................... 25 4.1 Scheduling ....................................................................................................................................................................... 25 4.2 Field Methods ................................................................................................................................................................. 25 4.3 Quality Control and Data Quality Objectives ..................................................................................................... 26 4.4 Data Quality Review and Data Management ..................................................................................................... 32

5 Mine Site Environmental Monitoring ............................................................................................................................... 34 5.1 Contact Water Chemistry ........................................................................................................................................... 34 5.2 Seep Sampling ............................................................................................................................................................... 35 5.3 Groundwater Monitoring ........................................................................................................................................... 35 5.4 Climate .............................................................................................................................................................................. 60

6 Discharge System and Monitoring .................................................................................................................................... 66 6.1 Discharge System .......................................................................................................................................................... 66 6.2 Discharge Monitoring ................................................................................................................................................. 67 6.3 Discharge Water Quality Results ............................................................................................................................. 68 6.4 Discharge Toxicity Testing Results ......................................................................................................................... 68

7 Hazeltine Creek Aquatic Environment Monitoring ..................................................................................................... 69 7.1 Surface Water Monitoring ......................................................................................................................................... 69 7.2 Groundwater ................................................................................................................................................................... 69 7.3 Hydrology ........................................................................................................................................................................ 69

8 Aquatic Receiving Environment ......................................................................................................................................... 72 8.1 Surface Water Quality ................................................................................................................................................. 72


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8.2 Lake Sampling ................................................................................................................................................................ 80 8.3 Hydrology ........................................................................................................................................................................ 82 8.4 Sediment Quality ........................................................................................................................................................... 85 8.5 Benthic Invertebrates ................................................................................................................................................... 85 8.6 Plankton, Chlorophyll a, and Secchi Disk............................................................................................................. 85 8.7 Fish ...................................................................................................................................................................................... 86

9 Terrestrial Monitoring ............................................................................................................................................................ 87 9.1 Wildlife Monitoring ...................................................................................................................................................... 87 9.2 Soil ...................................................................................................................................................................................... 89 9.3 Soil Invertebrate ............................................................................................................................................................ 90 9.4 Vegetation ....................................................................................................................................................................... 90

10 Annual Report Changes ......................................................................................................................................................... 91 11 Reclamation Program ............................................................................................................................................................. 92

11.1 Reclamation Cost Update .......................................................................................................................................... 92 11.2 Stability of Works .......................................................................................................................................................... 92 11.3 2016 Reclamation Activities ...................................................................................................................................... 94 11.4 2016 Reclamation Research Update ...................................................................................................................... 97 11.5 Five Year Reclamation Plan ..................................................................................................................................... 101

12 Mining Program ...................................................................................................................................................................... 104 12.1 Surface Development to Date ................................................................................................................................ 104 12.2 Projected Surface Development ........................................................................................................................... 110 12.3 Salvaging and Stockpiling of Surficial Materials ............................................................................................. 111 12.4 Acid Rock Drainage/Metal Leaching Characterization Program and Waste Disposal .................... 113 12.5 Test Heap Leach .......................................................................................................................................................... 118

13 Summary and Conclusions ................................................................................................................................................. 119 14 References ................................................................................................................................................................................. 120


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LIST OF TABLES

Table 1.1 Sections reviewed by a Qualified Professional ...................................................................................................... 8 Table 2.1 Summary of Permit 11678 amendments ................................................................................................................. 9 Table 3.1 Summary of authorizations for water discharge from the Mount Polley Mine .................................... 17 Table 3.2 Water storage conditions at end of 2016 ............................................................................................................ 19 Table 3.3 Aggressive and native seed mixes for reclamation .......................................................................................... 21 Table 3.4 Chemicals and reagents stored at the Mount Polley Mine site .................................................................. 22 Table 3.5 Blasting products stored at Orica Ltd.’s Mount Polley site ........................................................................... 23 Table 3.6 Hydrocarbon and Dangerous Goods Spills reported to Environmental Department in 2016 ........ 23 Table 3.7 Release of mine influenced water reported to Environmental Department in 2016 .......................... 24 Table 4.1 Water chemistry QC sample frequencies for MPMC monitoring programs .......................................... 27 Table 4.2 Duplicate Sample RPD Acceptance Criteria ........................................................................................................ 28 Table 4.3 Field replicate sample locations collected in 2016 ........................................................................................... 28 Table 4.4 Trip blanks sent for analysis in 2016 ...................................................................................................................... 30 Table 4.5 Field blanks sent for analysis in 2016 .................................................................................................................... 30 Table 4.6 Equipment blanks taken in 2016 ............................................................................................................................. 31 Table 4.7 Summary of KEM1 blank results that are 5x detection limit ........................................................................ 31 Table 5.1 Sampling events in 2016 at contact water quality sites ................................................................................. 34 Table 5.2 Monitoring well depth, elevation, location, and sampling information................................................... 40 Table 5.3 Mount Polley 2016 monthly precipitation, evaporation, and temperature data ................................. 61 Table 6.1 Sampling events in 2016 at discharge monitoring sites ................................................................................ 67 Table 6.2 Toxicity sampling events in 2016 at discharge monitoring sites ................................................................ 68 Table 8.1 Sampling events in 2016 at surface water quality sites .................................................................................. 72 Table 8.2 Summary of acute BCWQG exceedances for aquatic life at surface water monitoring sites .......... 73 Table 8.3 Lake water quality sampling locations in 2016 .................................................................................................. 80 Table 8.4 Secchi depth measurement events in 2016. ....................................................................................................... 86 Table 9.1 2016 wildlife observations at Mount Polley Mine ............................................................................................ 87 Table 11.1 Summary of MEM reclamation inspection recommendations .................................................................. 94 Table 11.2 Progressive reclamation completed at Mount Polley Mine as of December 31, 2016 ................... 95 Table 11.3 Metro Vancouver biosolids deliveries and applications at Mount Polley (2000 – 2014) ................ 98 Table 11.4 Results from biosolids storage facility composite sample taken November 28, 2016 .................... 99 Table 11.5 Five year progressive reclamation plan ............................................................................................................ 103 Table 12.1 Mount Polley Mine site existing and projected disturbance ................................................................... 104 Table 12.2 Changes in disturbed areas with closure footprints .................................................................................... 110 Table 12.3 MPMC soil stockpile inventory as of December 31, 2016 ......................................................................... 112 Table 12.4 Tonnes of waste taken from Cariboo and Wight Pits in 2016 (summarized using truck count data). ..................................................................................................................................................................................................... 113 Table 12.5 Quantities of waste rock, tailings, low grade ore, and other mine waste as of December 31, 2016. ..................................................................................................................................................................................................... 114 Table 12.6 Non-economic ore stockpiles total quantities as of December 31, 2016 ........................................... 114


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Table 12.7 Summary of ABA data from the operating pits in 2016. ........................................................................... 115 Table 12.8 ABA results from 2016 monthly tailings composite samples .................................................................. 115 Table 12.9 Site drainage water quality monitoring locations, and sampling periods and frequencies ........ 117 Table 12.10 Heap leach sump level in 2016.......................................................................................................................... 118

LIST OF FIGURES

Figure 2.1 Mount Polley Mine property location .................................................................................................................. 10 Figure 3.1 Springer Pit water level compared to estimated levels for exfiltration to groundwater (1030 masl) and overtopping (1050 masl) ........................................................................................................................................... 20 Figure 5.1 Mount Polley wind data for 2016 (left), and for fall 2012 to the end of 2016 (right) ....................... 62 Figure 5.2 Maximum, mean and minimum monthly temperature data for Mount Polley (2016 versus average) ................................................................................................................................................................................................. 63 Figure 5.3 Monthly rainfall at Mount Polley (2016 versus average) .............................................................................. 64 Figure 5.4 Monthly snowpack at Mount Polley (2016 versus average) ....................................................................... 64 Figure 5.5 Mount Polley 2016 monthly precipitation and evaporation ....................................................................... 65 Figure 11.1 2016 Soil Placement on the Highway to Heaven Site ................................................................................. 96


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APPENDICES

Appendix A: Permit 11678, 2016 CEMP (including approved changes) and site locations

Appendix B: PLC Meeting Minutes

Appendix C: Quality Assurance/Quality Control (Electronic format only)

Appendix D: Surface Water Quality Results (Electronic format only)

Appendix E: Review of Groundwater Characterization and Installation of New Groundwater Wells (Golder)

Appendix F: Groundwater Quality Results (Electronic format only)

Appendix G: Invasive Plant Management Plan

Appendix H: Hazeltine Creek and Discharge (Golder)

Appendix I: Quesnel Lake Monitoring

Appendix J: Hydrological Monitoring

Appendix K: Lake Water Quality (Electronic format only)

Appendix L: Waste Survey Data (Electronic format only)

Appendix M: Drainage Water Quality (Electronic format only)

Appendix N: Annual Status Form

ABBREVIATIONS AND ACRONYMS

ABA Acid-Base Accounting ABR Anaerobic Biological Reactor ALS ALS Environmental Inc. ARD Acid Rock Drainage ARD/ML Acid Rock Drainage/Metal Leaching BC British Columbia BCWQG British Columbia MoE Water Quality Guideline CCS Central Collection Sump CEMP Comprehensive Environmental Monitoring Plan CMDRC Cariboo Mine Development Review Committee DGR Dangerous Good Regulations DQO Data Quality Objectives EC Electrical Conductivity ELS Early Life Stage EMA Environmental Management Act EoR Engineer of Record ERA Ecological Risk Assessment Golder Golder Associates Ltd. HGSP High Grade Stockpile


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HHERA Human Health and Ecological Risk Assessment HHRA Human Health Risk Assessment HSRC Health, Safety and Reclamation Code for Mines in British Columbia IDZ Initial Dilution Zone KEM1 Kemmerer water sampler LCRS Leachate Collection Recycle System LTWDP Long Term Water Discharge Plan MDL Method Detection Limit MEM Ministry of Energy and Mines MESCP Main Embankment Seepage Collection Pond MoE Ministry of Environment MMER Metal Mine Effluent Regulations MPMC Mount Polley Mining Corporation MTD Main Toe Drain NAG Non-Acid Generating NBD North Bell Dump NEZ Northeast Zone NPP NAG/PAG Pad NPR Neutralizing Potential Ratio NW Temporary Northwest OCA Oil Containment Area PAG Potentially Acid Generating PAO Pollution Abatement Order PAR Plug Access Road PEEIAR Post-Event Environmental Impact Assessment Report PETBP Perimeter Embankment Till Borrow Pit PESCP Perimeter Embankment Seepage Collection Pond PLC Public Liaison Committee POI(s) Parameter(s) Of Interest QA Quality Assurance QA/QC Quality Assurance/Quality Control QP Qualified Professional RCP Reclamation and Closure Plan RDS Rock Disposal Site RMDRC Regional Mine Development Review Committee RPD Relative Percent Difference SCIB Soda Creek Indian Band SERDS Southeast Rock Disposal Site SEZ Southeast Zone STD South Toe Drain STWDP Short Term Water Discharge Plan SWL Static Water Level SWE Snow water equivalent TAR Technical Assessment Report TERA Terrestrial Ecological Risk Assessment


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TDAR Tailings Dam Access Road TOR Terms Of Reference TSF Tailings Storage Facility TSS Total Suspended Solids UTM Universal Transverse Mercator VAN2 Van Dorn water sampler WHR Waste Haul Road WLIB Williams Lake Indian Band WQG Water Quality Guidelines WTP Water Treatment Plant

UNITS

dt dry tonnes ha hectare(s) m metre(s) masl metres above sea level m3 cubic metre(s) m3/s cubic metre(s) per second mm millimeter(s) mg/L milligrams per litre ppm parts per million SPH Stems Per Hectare t tonne(s) tpd tonne(s) per day


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1 Introduction

Mount Polley Mining Corporation (MPMC) is required to submit two annual reports; one to the British Columbia (BC) Ministry of Environment (MoE), and a second to the BC Ministry of Energy and Mines (MEM). Beginning with the reporting year of 2000 and continuing through 2016, these two reports have been combined into one for submission to both ministries.

In 1995 and 1996, an environmental monitoring program (which expanded on previous studies from 1989 and 1990) was designed and implemented in order to support mine planning, operations, and reclamation. The program included baseline studies documenting the pre-development land uses and the conditions of the aquatic and terrestrial ecosystems. This information provides the foundation upon which operational environmental monitoring programs are based. The November 29, 2015 Permit 11678 amendment includes a revised condition, as recommended by MPMC, to develop a coordinated Comprehensive Environmental Monitoring Plan (CEMP) to evaluate the effects of mining-related activities on the physical, chemical, and biological characteristics of Hazeltine Creek, Edney Creek, Bootjack Lake, Morehead Creek, Polley Lake, Quesnel Lake, Quesnel River, and associated riparian and upland areas. The revised plan was submitted to the MoE on June 23, 2016 and is provided as Appendix A along with the amended Permit 11678.

1.1 Objectives

Environmental monitoring according to the CEMP (Appendix A) is ongoing, The CEMP includes figures showing all monitoring locations, fulfilling both the requirements of the M–200 permit under the MEM and Environmental Management Act (EMA) Permit 11678 (Appendix A) under the MoE. The objective of this monitoring is to assess the environmental effects of mining activities at Mount Polley Mine on the receiving environment.

Monitoring results for 2016 are reported in subsequent sections of this report as follows:

• Chemistry and quantity of surface, seepage, and groundwater;

• Aquatic biology;

• Water levels in groundwater wells;

• Stream flows and water levels;

• Meteorology (temperature, precipitation, snowpack, evaporation rates); and

• Wildlife observations.

1.1.1 Reclamation Objectives

In accordance with the BC Mines Act and the Health, Safety and Reclamation Code for Mines in British Columbia, the primary objective of the Reclamation and Closure Plan (RCP) (MPMC, 2017a) is to:


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“return all mine-disturbed areas to an equivalent level of capability to that which existed prior to mining on an average property basis, unless the owner, agent or manager can provide evidence which demonstrates to the satisfaction of the chief inspector the impracticality of doing so”.

To achieve these objectives, reclamation and closure prescriptions are continually being refined based on the results from the ongoing reclamation research program (Section 11). An updated RCP was submitted to the MEM on January 15, 2017 (MPMC, 2017a).

.The main objective of the reclamation program is to return all areas that have been disturbed by mining operations (except pit walls) to equivalent or greater land capability than existed prior to mining, on an average property basis.

To achieve this target, MPMC has proposed end land use objectives that are focused on an ecosystem approach. The ecosystem approach considers all ecosystem components and the resulting ecosystem services in reclamation planning. These ecosystems can be mapped on appropriate areas of the landscape, but rather than limiting each area to one designated end land use (e.g., wildlife habitat), this approach will allow for multiple, compatible end land use objectives to be targeted. End land uses that are encompassed in the target ecosystems over time include forest cover, wildlife habitat, hunting, trapping, guide outfitting, traditional use, livestock grazing, and recreation.

An End Land Use Plan has been developed that focusses on ecosystem rehabilitation as the main goal with a target towards ecosystems that occurred in the pre-disturbance conditions (Section 5.2). The End Land Use Plan also estimates shifts in the end land use objectives over time as the ecological trajectories of the ecosystem mature. This ensures that end land use planning is considered over the long-term and that a variety of end land uses can occur on the landscape over different temporal scales.

The following goals are implicit in achieving these end land use objectives:

• Long-term preservation of water quality within and downstream of decommissioned operations;

• Long-term stability of engineered structures, including the waste rock dumps, Tailings Storage Facility (TSF), and open pits, as well as all exposed erodible materials;

• Removal and proper disposal of all access roads, structures, and equipment not required after the Mine closes;

• Natural integration of disturbed lands into surrounding landscape, and restoration of the natural appearance of the area after mining ceases, to the greatest possible extent; and

• Establishment of self-sustaining vegetation covers, consistent with the end land uses.

Once these aspects are in place, flexibility exists to modify ecosystem composition, patch size, and


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vegetation mosaic and to provide additional structural components, as required. By reclaiming disturbed land to stable, functioning, locally appropriate ecosystems that can reasonably be expected to thrive on a specific landform or location, a variety of end land use objectives can also be met.

End land use objectives envelop a multitude of values that may exist beyond ecological conditions and are driven by what regulators, MPMC, First Nations, and local communities prefer for the landscape once the Mine is closed. End land use decisions are influenced by several factors, including:

• Permit obligations;

• Regulatory requirements;

• Landform design;

• Surface and subsurface materials at closure;

• Surface water hydrology;

• Slope;

• Aspect,

• Elevation;

• Input from First Nations, local communities and stakeholders; and

• Traditional and cultural land use.

End land use objectives may be adapted over time as interests evolve; however, once a landform is constructed, the end land uses are limited to the conditions and ecological trajectories associated with the particular ecosystem that has been rehabilitated.

Site research that was initiated at the Mine in 1998 indicates that conifer growth on reclaimed waste rock dumps is an attainable goal for parts of the Mines Site. To create appropriate microsites for conifers that grow in later successional stages; however, it is often necessary to promote early successional stage vegetation growth, allowing the process of natural succession to establish suitable vegetation cover and moisture conditions. Establishment of early successional stage communities can effectively support functioning ecosystems. Over time, as succession and native species ingress occur at reclamation sites, climax forest communities will be established.

Rehabilitation of the Mine Site’s wildlife capability will require development of self-sustaining vegetation that imitates pre-development cover. Recreation of the natural appearance and creation of suitable habitats will allow for natural integration of disturbed lands into the surrounding landscape and improve wildlife use and access over time once the Mine has reached full closure. Post-closure, as wildlife usage increases and public access to parts of the site is re-established, the MFLNRO will have the opportunity to sanction the end land uses of hunting, guide outfitting, and trapping.

Similarly, livestock grazing is a compatible end land use; as there is overlap in wildlife and livestock forage


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species and vegetative cover preferences. Other forms of outdoor recreation, including sport fishing, will be supported by maintaining appropriate water quality and aquatic habitats in receiving environment water bodies.

1.1.2 Ministry of Energy and Mines

The Annual Reclamation Report for the MEM, as required by Permit M-200, requires a summary and description of the past year’s mining and reclamation program including:

• A summary of disturbed areas and surface development.

• Updated disposal or storage locations for tailings, waste rock, ore, overburden or other materials, and associated volumes.

• A description of the environmental protection program over the reporting year and projected changes to the program, including surface water and groundwater quality, water management, Acid Rock Drainage/Metal Leaching (ARD/ML) characterization and management, wildlife protection, and sediment and erosion control.

• Drainage monitoring programs, including flows and water quality.

• Geological characterization and material characterization test work.

• An update on completed site reclamation, reclamation research, and reclamation plans for the next 5 years.

• Reclamation liability cost estimates.

1.1.3 Ministry of Environment

As per the most recent amendment of EMA Permit 11678 (September 2016; Appendix A) the Annual Report must include:

• All monitoring sample quality results required under the permit.

• An evaluation of quality assurance, including collection, sampling, and data handling protocols.

• An evaluation of the treatment plant operation and control.

• An evaluation of the impacts of the mining operation on the receiving environment from the previous year.

• A summary of any non-compliance with the permit and other incidents that may have led to impacts to the receiving environment.

• An update to the water balance.

• An update to models for Springer Pit groundwater discharge and the outfall dispersion in Quesnel Lake.

• An update to the long term water management plan.


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• A review and update of the assessment of ARD potential and water quality impacts from mine waste management.

• A comparison of monitoring data with water quality guidelines, predictions and targets.

• An update on the progress of reclamation and any updates to the reclamation plan.

• An evaluation of the effectiveness of the Surface Runoff and Mine Drainage Control programs.

• A summary of the Public Liaison Committee meetings, and issues and concerns presented.

• An evaluation of the Outfall and Pipeline Inspection programs.

• An update on the groundwater monitoring results for the preceding twelve months.

The purpose of this document is to allow the MoE to: identify whether spills or incidents have been dealt with appropriately; evaluate permit compliance; identify environmental effects; verify predictions of effects; and identify whether the permit adequately protects the environment or if changes are required.

1.2 First Nations and Stakeholders

Note that the activities outlined below do not include First Nations, stakeholder, and community engagement carried out specifically in relation to the TSF embankment breach and post-dam failure monitoring and rehabilitation.

1.2.1 First Nations Engagement

First Nations with recognized claimed traditional territory for the Mount Polley Mine are the T’exelc (Williams Lake Indian Band; WLIB) and the Xatśūll First Nation (Soda Creek Indian Band; SCIB).In 2011 and 2012, MPMC executed Participation Agreements with the WLIB and the SCIB, respectively. Through these respective Participation Agreements, Implementation Committees were formed in order to facilitate open dialogue between each of the First Nations and MPMC, providing a formalized, regular venue to discuss environmental, social and economic matters related to mine development, operation, reclamation, and closure (e.g., mine updates, permitting, environmental protection, reclamation, employment opportunities, and potential joint ventures). Meetings have taken place since March 16, 2012 with the WLIB and since July 19, 2012 with the SCIB. Effective October 18, 2012, Joint Implementation Committee meetings have been held with representatives from MPMC, the WLIB, and the SCIB, replacing the previous MPMC/SCIB and MPMC/WLIB Implementation Committee meetings. Joint Implementation Committee meetings are held at minimum quarterly, but typically more frequently. These meetings and associated documentation ((Terms of Reference (ToR), minutes, and action items) provide a well-defined, constructive forum in which issues, reviews, and comments relating to the current and anticipated future operations of the Mount Polley Mine may be discussed. This Annual Environmental and Reclamation Report (report) will be provided in its current form to the SCIB and the WLIB for review, and discussion regarding any comments or concerns will be facilitated through the Joint Implementation Committee.


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Eight (8) Joint Implementation Committee meetings were held in 2016: February 25, 2016; March 24, 2016; May 5, 2016; May 25, 2016; July 21, 2016; August 24, 2016; September 28, 2016; and November 9, 2016. Numerous additional technical working meetings were facilitated by MPMC and attended by subgroups of the Joint Implementation Committee membership. Such technical working meetings were scheduled for topics including environmental monitoring, site water management and reclamation and closure planning, amongst others.

1.2.2 Regional Mine Development Review Committee

In 2014, the Regional (Cariboo) Mine Development Review Committee (CMDRC) was revived by the MEM. The CMDRC is a regionally based multi-agency review committee chaired by the MEM. Participants include representatives from MPMC, local, provincial, and federal government agencies and First Nations. Members of the public are also invited to participate on a meeting topic-specific basis. Three (3) formal, in-person, Mount Polley Mine CMDRC meetings were held in 2016: February 4, 2016; April 15, 2016 and December 15, 2016.

The RMDRC also acts as a venue for communication related to permit amendment applications under the EMA permits, or other regulations administered by the MoE and the BC Ministry of Forests, Lands and Natural Resource Operations. While communication related to EMA permit amendments will be conducted as per the EMA Public Notification Regulation, information is presented through the CMDRC, where possible, to coordinate review and consultation with parallel Mines Act permit amendments and other updates on the Mount Polley Mine site, with the goal of making efficient use of CMDRC member’s (government, First Nations, and community representatives) time.

Two (2) additional teleconference and check-in CMDRC meetings were also held to complement CMDRC review processes: March 17, 2016; and May 16, 2016.

1.2.3 Public Liaison Committee

The intention of the Public Liaison Committee (PLC) is to provide an opportunity for MPMC to share information about mine activities and monitoring results with its members. The members are then responsible for relaying information between MPMC and the group or individuals for which they are the Designated Representative.

MPMC held five (5) PLC meetings in 2016: February 18, 2016; May 12, 2016; August 18, 2016; October 26, 2016 and November 17, 2016. Four (4) of these meetings were standard quarterly meetings as described in the Terms of Reference (TOR) for the PLC (approved March 2016) and one (1) meeting (October 26, 2016) was an extraordinary meeting held to review the Technical Assessment Report for the Long-term Water Management Plan. Site tours were completed during the May 12, 2016 and August 18, 2016 meetings. Minutes for all 2016 PLC meetings are included in Appendix B.


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The Permit 11678 amendment issued July 9, 2015, required the submission to, and approval by, the Director of a (TOR) for the PLC. The final TOR was reviewed with the PLC during the February 18, 2016 meeting. The TOR was finalized and submitted to the MoE on March 20, 2016 and was accepted by the Director on May 11, 2016. The Permit 11678 (Appendix A) amendment issued September 19, 2016 requires that a summary of the PLC meetings and issues and concerns be presented in this annual report. MPMC has chosen not to provide this as a summary but instead has provided the meeting minutes in full in Appendix B.

In 2016, all the PLC meetings were well attended with between 15 and 20 attendees at each meeting. Lists of the attendees are included in the meeting minutes in Appendix B. At each of the regular PLC meetings, MPMC provided a site update, an update on the short-term water management plan including an overview of the water discharge system and the current water balance, and an update on all environmental monitoring. As outlined in the TOR, the PLC is intended to provide opportunity for MPMC to share information about mine activities and the results of monitoring programs with PLC members and for members to share such information with their respective membership (community).

1.2.4 Communication Plan

Permit 11678 (Appendix A) requires a Communication Plan between MPMC and the WLIB, SCIB, Cariboo Regional District, and the Community of Likely to be in place. This communication plan is in place and was approved by the Director on May 11, 2016.

1.3 Qualified Professionals

According to Section 2.15 of the EMA Permit 11678, “reports where an opinion or recommendation is expressed regarding data analysis, interpretation, assessment, and/or design must also be sealed by an appropriately qualified professional [QP]”. The sections of this annual report that fall under this requirement are provided in Table 1.1, along with the QP that has reviewed that section. Seals, where appropriate, have been provided in the applicable appendix, which are also summarized in Table 1.1.


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Table 1.1 Sections reviewed by a Qualified Professional

Section Qualified Professional Appendix

4 Pierre Stecko, M.Sc., EP, RPBio C

5.1 Pierre Stecko, M.Sc., EP, RPBio D

6.3 Elaine Irving, PhD., R.P. Bio., P. Biol H



7.3 Russell Smith, PhD, RPF: WaterSmith Research Inc J



8.3 Russell Smith, PhD, RPF: WaterSmith Research Inc J


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2 Mount Polley Mine Project Overview

2.1 Project History

Mount Polley Mine, operated by MPMC (a wholly owned subsidiary of Imperial Metals Corporation), is an open pit copper/gold mine with an underground component, and has the capacity to process 20,000 to 22,000 tonnes per day (tpd) of ore. The Mine is located eight kilometres (km) southwest of Likely and 56 km (100 km by road) northeast of Williams Lake, BC (Figure 2.1). The Mount Polley property covers 18,892 hectares (ha), which consist of seven mining leases totaling 2,007 ha, and 43 mineral claims encompassing 16,855 ha. Mount Polley concentrates are trucked to facilities at the Port of Vancouver and then shipped to overseas smelters or transported by rail to smelters in North America.

Clearing of the site and construction of the entire facility began in 1995, with the mill being commissioned in June 1997. In May 1997, the Mine received a MoE (previously the Ministry of Water, Land and Air Protection) Effluent Permit, Permit 11678, issued under the provisions of the provincial EMA. This permit authorized the discharge of concentrator tailings, mill site runoff, mine rock runoff, open pit water, and septic tank effluent to a tailings impoundment. Approval of the “Mount Polley Mine Reclamation and Closure Plan” by the MEM resulted in the issuance of Permit M-200 in July 1997. The first full year of mining and milling at Mount Polley Mine took place in 1998. The mine suspended operations in October 2001 due to low metal prices, then reopened in December 2004; mill production commenced again in March 2005. A summary of Permit 11678 amendments is provided in Table 2.1.

Table 2.1 Summary of Permit 11678 amendments

Date Scope of Amendment 30-May-1997 Original permit 20-Oct-1997 Amended authorized tailings discharge rate (10,000 tpd increase) 12-Jun-1998 Amended reporting requirements 8-Sep-1999 Amended monitoring requirements 1-Feb-2000 Amended authorized tailings discharge rate (4,500 tpd increase)

7-Feb-2002 Approval to discharge effluent from the Perimeter Embankment Seepage Collection Pond (PESCP) and Main Embankment Seepage Collection Pond (MESCP); approval to store TSF supernatant and Mine Site contact water in the Cariboo and Bell Pits

4-May-2005 Amended authorized tailings discharge rate (5,000 tpd increase); discharge of groundwater to Polley Lake; updates to reference analytical procedures and monitoring program

17-Apr-2009 Amended monitoring, water level and supernatant characteristic requirements for the Cariboo and Bell Pits

7-Nov-2012 Approval to discharge to Hazeltine Creek 7-Jun-2013 Sulphate guidelines 9-Jul-2015 Tailings discharge to the Springer Pit 29-Nov-2015 Approval to discharge to Hazeltine Creek 4-Apr-2016 Discharge of additional tailings to the Springer Pit 9-Sep-2016 Hazeltine Creek discharge total suspended solids limit change


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Figure 2.1 Mount Polley Mine property location


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2.1.1 Tailings Storage Facility Embankment Breach

On August 4, 2014, a breach occurred in the Perimeter Embankment of the TSF; this event is herein referred to as the “TSF embankment breach”. The TSF embankment breach released tailings, water, and embankment construction materials to the downstream environments of Polley Lake, Hazeltine Creek and Quesnel Lake. The MoE issued MPMC Pollution Abatement Order (PAO) 107461, dated August 5, 2014, ordering MPMC to attend to the environmental impacts of the TSF embankment breach. As of December 31, 2016 the PAO remains in effect and MPMC continues to meet its requirements.

2.1.1.1 Implications for Reporting

Following the TSF embankment breach, an environmental monitoring program was initiated in downstream areas including Polley Lake and Hazeltine Creek, both of which were previously monitored under Permit 11678 (Appendix A). Monitoring of these areas in 2014 and 2015 was under MoE Pollution Abatement Order 107461; consequently, these monitoring results were not discussed in this report, but were presented in the Post-Event Environmental Impact Assessment Report (PEEIAR; MPMC, 2015a; submitted to the MoE on June 6, 2015; publicly available online), PEEIAR Version 2 (MPMC, 2016a; publicly available online). Results from some monitoring conducted in 2016 will be presented in documents associated with the Human Health Risk Assessment (HHRA) and Ecological Risk Assessment (ERA), which are both due in 2017; these are identified in their respective sections. Water quality results from 2016 will be presented in this report.

Similarly, the reclamation sections of this report, including surface development, bond costing, and reclamation plans exclude the areas downstream of the TSF embankment breach. These areas are part of independent liability calculations, and rehabilitation is currently being managed under MoE Pollution Abatement Order 107461.

2.2 Current Project Status

2.2.1 Mine Operations

On November 6, 2015, MPMC applied for an amendment to Permit M-200 to allow for the return to full operations at the Mount Polley Mine, with use of the TSF for tailings deposition. Included in the application package were: an updated Reclamation and Closure Plan reflecting the proposed development; an operational water management plan; a TSF Life of Mine Feasibility Plan (984 masl); and a detailed TSF design to 970 masl. A corresponding Permit M-200 amendment was received from the MEM on June 23, 2016. Authorization to resume deposition of tailings in the TSF under Permit 11678 was received from the MOE on June 23, 2016. MPMC resumed deposition of tailings in the TSF (as opposed to the then-authorized discharge of tailings in the Springer Pit) on June 27, 2016.

Currently authorized operations allows for: open pit mining of the Phase 4 Cariboo-Springer Pit and


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Boundary Pit; underground development of the Boundary Zone; milling of up to a maximum of 8,200,000 tonnes (t) of ore per year with deposition in the TSF; and, construction and operation of the TSF up to an elevation of 970 masl.

The current active project infrastructure consists of the Mill site, mining in the Cariboo Pit, two (2) rock disposal sites (RDSs) (the Southeast Rock Disposal Site (SERDS), and the Temporary Northwest (NW) Potentially-Acid Generating (PAG) Stockpile), the TSF, as well as access roads, power lines, a tailings pipeline, drainage collection systems, and sediment/seepage control ponds. Additional active mining is ongoing in the Boundary Zone underground operation, with the portal in the bottom of the Wight Pit. The Boundary Zone Pit, the Pond Zone Pit, the Southeast Zone (SEZ) Pit, the Bell Pit, and the Springer Pit are not currently active. Back-filling of the Bell Pit and Pond Zone Pit with waste rock was completed in 2012, and the SEZ Pit was backfilled in 2013. A detailed mine site map is included in Appendix A.

No permits for operation beyond the Phase 4 Cariboo-Springer Pit development are in place; however, identified ore reserves indicate approximately ten (10) more (cumulative) years of viable mine life. Given the uncertainty around future operations and mine life, reclamation and closure planning described in this document are subject to change.

2.3 Environment

2.3.1 Topography and Climate

The Mount Polley property is located on the eastern edge of the Fraser Plateau physiographic sub-division, characterized by rolling topography and moderate relief. Elevations range from 920 masl at Polley Lake to 1266 masl at the summit of Mount Polley. Volcanic rocks general underlay this part of the plateau with inclusions of intrusive rocks. Most of the area is covered by a deposit of unconsolidated till which contains fluvial, lacustrine, and colluvial deposits. Some patches of organic soils are present in poorly drained areas (i.e., wetlands). The property is located in an alkali porphyry copper-gold deposit hosted in the Central Quesnel Belt along the Intermontaine Belt of BC.

The site is located within the Interior Cedar Hemlock biogeoclimatic zone. Local forests consist of Western red cedar, Douglas-fir, hybrid spruce, and subalpine fir, with a lesser presence of trembling aspen, black cottonwood, and paper birch. Much of the area has been harvested in commercial logging operations and is also used for cattle grazing.

Average annual precipitation in the study area is 670 millimetres (mm). Precipitation typically occurs as snowfall from November through March, with an average maximum of snowpack of 178 mm snow water equivalent occurring at the end of March (Golder 2015a). Average monthly temperatures at the Mount Polley Mine range from -6.0 degrees Celsius (°C) in January to 15.3 °C in July and August (MPMC 2016b). Prevailing winds are from the north-north-east and from the south-south-west near the TSF, and from the northwest (and to a lesser extent the southeast) near the mill, with a predominance of winds designated


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as calm (below 3 metres per second; Golder 2015a ).

2.3.2 Hydrogeology

The groundwater flow at the site occurs primarily in the bedrock units in response to recharge from precipitation in the area between Polley Lake and Bootjack Lake. Flow in the overburden is less significant due to its limited thickness and discontinuous nature. Prior to mining, the water table at the site generally followed the surface topography, but the water table was deeper below the topographic heights and shallower in the low areas. At that time, the direction of groundwater flow was inferred to be from the top of the ridge between the Polley Lake and the Bootjack Lake towards the low lying areas associates with these lakes northeast and southwest from the ridge.

Mine dewatering has altered the groundwater flow pattern at the site, with the open pits and underground workings acting as sinks for groundwater flow. Mine dewatering lowered the water table elevation and created radial patterns of groundwater flow towards these facilities. At present, Springer Pit water level is being drawn down and the pit lake acts as a groundwater sink. The currently available information suggests that some seepage from the lake towards Bootjack Lake could occur once the pit lake level reaches 1020 m to 1030 m elevation (Golder 2015a).


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3 Environmental Management

3.1 Water Management

3.1.1 Water Management System Update

The Mount Polley Mine runoff collection and water management system as of the December 31, 2016 is presented in Appendix A. Changes to this system in 2016 include:

• System changes to allow commencement of full mining and milling operations in June 2016, including:

– Removal of the tailings line from the Mill to the Springer Pit and re-commissioning of the tailings line from the Mill to the TSF; and,

– Re-commissioning of the barge in the TSF in November 2016 to provide reclaim water to the Mill

• Work specific to the operation of the WTP:

– Installation of a pipe from the Springer Pit to the Water Treatment Plant (WTP) to allow for direct feed of Springer Pit water into the WTP.

– Construction of an improved WTP ‘sludge’ management system, comprising construction of a multi-stage settling armoured settling pond with equipment access for sediment accumulation removal and /or maintenance.

• Modifications made to accommodate buttressing work at the Main Embankment:

– The MESCP was cleaned to foundational tills and partially backfilled with coarse rip-rap

• Construction of the Junction Zone Seepage Sump to collect a seep that was flowing under the Junction Zone Ditch.

• Seasonal changes, including:

– Installation of the turbomisters (two located at Corner 5 of the TSF, and one installed at the crusher piles), East RDS sprinklers, and a sprinkler system on the TSF surface (for evaporation and dust control purposes) in spring, and decommissioning of the infrastructure prior to winter.

• Installation of a temporary water truck filling station from the WTP for the 2016 TSF dam raise.

3.1.2 Water Management System Upgrades

Based on results from the bi-annual sump and ditch inspections (required under Permit 11678 found in Appendix A), as well as daily water management infrastructure inspections, environmental monitoring, and other observational activities (often as components of the MPMC’s Sediment and Erosion Control Plan in Section 3.2),


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MPMC completed and submitted a Water Management Plan and System Review to the MEM on March 31, 2016, as required under conditions of Permit M-200. This Water Management Plan and System Review provided: an overview of water management planning at the Mount Polley Mine; an update on site works completed since the issuance of the July 9, 2015 Permit M-200 amendment requiring its development; a review of the design criteria and operational requirements of the water management system, as completed by third party Qualified Professionals; a summary of the outcomes of the third party review; and, planned work. Based on this identification of planned work, in addition to routine maintenance, upgrades, and modifications made to facilitate the water management changes outlined in the previous section, the following project work was conducted in 2016:

• Work on clean water diversion systems:

– Upgrading, till lining and armouring of the Gavin’s Ditch clean water diversion and sump system to North Dump Creek.

– Upgrading and armouring of the Wight Pit – South Branch clean water diversion system to North Dump Creek.

– Reconstruction of the intakes for the Bootjack Creek clean water culverts (under the TAR).

• Work on expansion of site contact water collection systems:

– Extension of the ditch system between the 9K Sump Ditch system and the NW PAG Sump Ditch system based on recommendations received from a third party Qualified Professional as relating to water management below the Temporary NW PAG Stockpile.

• Improvements to existing site contact water collection systems:

– Reconstruction of parts of the SEZ Ditch that were impacted by re-contouring of the Highway to Heaven for reclamation purposes.

– Reconstruction of the ditch collecting runoff from the fuel island.

– Reconstruction of the CCS overflow (an armoured open flow channel that travels under the PAR via culverts was created).

– Upgrades to the Junction Zone Ditch, including improving sections of the till lining and re-grading the lower reach.

– Upgrading to increase culvert capacity for West Ditch road crossings.

– Upgrading and armouring the north branch of the Mine Drainage Creek ditch, including capping of the parallel inspection access road.

– Upgrading and armouring of approximately 525 m of the lower Long Ditch, including capping of the parallel inspection access road. This work was informed by review of design flows conducted by a third party Qualified Professional to reduce mobilization of suspended particles during open ditch flow.

– Upgrading and armouring the ditch between the CCS and the PETBP, including capping of the parallel inspection access road.

– Upgrading and armouring of the ditch conveying flow from the SESCP pump-back system, South Embankment toe drain and local runoff to the MESCP.


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– Upgrading of the alignment for the MESCP pump-back system to the PETBP and parallel inspection access road was substantially completed by December 2016 and is anticipated to be completed in 2017.

– Minor upgrades and general maintenance on the already armoured sections of the West Ditch and Long Ditch based on a review by and recommendations from a third party Qualified Professional.

– Upgrading of the drainage pathway for the old Tailings Haul Road access, including construction of settling ponds and direction into the Long Ditch Sump water collection system in a controlled manner.

– Upgrading of the drainage pathway to transfer runoff from the TAR into the SERDS Ditch in a controlled manner.

– Upgrading of the overflow drainage pathway (to the SERDS Ditch) for the gravity-feed portion of the upper West Ditch upstream of the light-duty Tailings Access Road.

– Upgrading of the overflow drainage pathway (towards the Orica Ditch) for the SERDS Ditch upstream of the Tailings Access Road culverts.

– Upgrading of the overflow system for the Junction Ditch system.

– Cleaning out of deposited material settled in the SERDS Sump.

– Upgrading of the MESCP pump-back system for increased water availability to the TSF, which facilitates operation of the TSF sprinklers.

3.1.3 Water Discharge Background

MPMC has a positive water balance and the annual surplus of water has increased over the life of the project as the mine footprint has expanded, necessitating the collection of surface runoff from a larger area. A surplus of water accumulated in the TSF and water was discharged to Edney Creek under Permit 11678 during the period in the early 2000’s when the mine was in care and maintenance due to low metal prices. In November 2011, MPMC received an amendment to Permit 11678 that allowed for discharge of dam filtered water into Hazeltine Creek; however, permit restrictions on the quality and quantity of water to be discharged, discharge season, and water source did not allow for MPMC to fully discharge the surplus water that was accumulating in the TSF. At the time of the TSF embankment breach, MPMC was actively pursuing permit amendments for a short-term discharge (reverse osmosis-treated water to Polley Lake, with the process reject stream (brine) stored in the TSF), to manage the surplus of water for a period of approximately three to four years while a long-term water management plan was developed.

Following the TSF embankment breach, MPMC had no permitted discharge, and all contact water was being stored in the Springer Pit. However, the mine site continued to have a positive water balance (Golder 2015a) and the Springer Pit has a finite capacity. Golder estimated that once the pit water elevation reaches approximately 1,030 m above sea level (masl), the water will exfiltrate to the groundwater and discharge towards Bootjack Lake. At 1,050 masl the Springer Pit will overflow. Therefore,


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a short-term water management plan was developed following the TSF embankment breach; MPMC applied for and received an amendment to Permit 11678 (along with the required supporting permits and authorizations) for a short-term water discharge to be utilized in the interim, while consultation and planning is carried out to develop a long-term water management strategy. The short-term discharge expires on November 30, 2017, at which time the long-term water management strategy will be implemented.

Table 3.1 provides a summary of water discharge authorizations from the Mount Polley Mine. The current authorized discharge is discussed in further detail in Section 6.

Table 3.1 Summary of authorizations for water discharge from the Mount Polley Mine

Date Discharge Source Permitted Discharge Location Comments

7-Feb-2002 MESCP Edney Creek Discharge discontinued in 2005; no longer permitted.

7-Nov-2012 Dam filtered Hazeltine Creek Discharge discontinued in 2014; no longer permitted.

29-Nov-2015 Springer Pit, and site runoff and seepage collection water management systems

Quesnel Lake via Hazeltine Creek

Current discharge; see Section 6.

3.1.4 Short-Term Water Management Plan

On July 16, 2015, MPMC applied to the MoE for an amendment to EMA Permit 11678 to allow short-term (maximum two year) discharge of treated mine effluent to Quesnel Lake via the Hazeltine Creek channel which has been constructed and armoured, but is not yet appropriately rehabilitated to allow return of fish to the system (i.e., is not fish bearing). The permit amendment was received on November 30, 2015, authorizing discharge until November 30, 2017. MPMC commenced discharging on December 1, 2015.

The short-term water management plan is described in Section 6.1. The proposed short-term water discharge option was selected in an options analysis workshop with First Nations, public, and regulatory representatives on May 8, 2015 because: it does not require extensive infrastructure that will influence or bind long-term option selection; it can convey the necessary flows to a receiving environment with an appropriate dilution ratio; and, Hazeltine Creek is currently not fish-bearing. This is only considered a short-term option, as MPMC plans to continue rehabilitating Hazeltine Creek and return it to fish-bearing status.

Construction of required pipelines and diffusers, and procurement of water treatment infrastructure was completed prior to October 30, 2015, as required by the July 9, 2015 Permit M-200 amendment, and this infrastructure was incorporated into the site December 15, 2015 OMS Manual update. The environmental monitoring program was initiated, as described in Section 6.2.

Additional details on the discharge system and assessment of potential effects on the receiving


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environment are available in the Mount Polley Mine: Short Term Effluent Discharge Technical Assessment Report in Support of an Effluent Permit Amendment developed by Golder (2015a).

3.1.5 Long-Term Water Management Plan Development

MPMC developed a long-term water management plan in parallel with the implementation of the short-term water management plan in 2016. Permit 11678 (Appendix A) conditions include the following milestones, which will dictate the timeline for transition to the long-term water management plan:

• An Alternative Discharge Design and Construction Plan was due January 31, 2015. • A draft Long-term Water Management Strategy Technical Assessment Report was submitted June

30, 2016. The final report was submitted October 17, 2016 followed by the submission of the amendment application on October 20, 2016.

• Development and implementation of an alternative to the discharge to Hazeltine Creek is required by November 30, 2017.

• The short-term water discharge is authorized only for a two-year period, ending November 30, 2017.

3.1.6 Water Balance

MPMC retains Golder to maintain a predictive water balance for the Mount Polley Mine site using GoldSimTM software. This model generates probabilistic flow and water accumulation rates for site water collection system components. Note that this model has also been adapted to model conditions during operations (for restricted operations and proposed full operations), as well as at closure (immediately following closure, when reclamation work is ongoing; restricted operations and full operations scenarios) and in post-closure following reclamation work.

The water balance is used for planning purposes, such as water discharge planning, with routine revised projections made based on actual observed site conditions (i.e., water levels and storage volumes). The model also undergoes routine validation through comparison of predicted and observed accumulations, based on actual precipitation conditions. Model validation was carried out in June 2016 (following the previous validation in December 2015), and water volumes in Springer Pit have been continuously monitored and compared to predictions from the site-wide water balance model. Results indicate that:

“Based on 2016 accumulations in the Springer Pit, the site wide water balance model is providing good estimates of water volumes at the Mount Polley Mine site. Starting with the initial conditions as of April 1, 2016 (water levels, observed precipitation, and snowpack), the water balance model forecast a peak water elevation in the Springer Pit of approximately 1037.7 m (mean prediction) on July 1, 2016, which correlates well with the actual level of 1038.5 m observed on June 25, 2016. Observed water levels in


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the Springer Pit during subsequent dewatering have generally tracked the mean prediction. During the summer months of 2015, under extreme dry conditions, the water balance model was predicting larger than observed volumes. However, on return to average or wet conditions in 2016, the predicted volumes agree well with observed. Overall, the site wide water balance model has demonstrated to be a reliable tool for managing water at the Mount Polley Mine” (Millar 2016).

Current water storage conditions on site are summarized in Table 3.2 and a comparison of Springer Pit water levels to estimated levels at which exfiltration to groundwater (1030 masl) and overtopping (1050 masl) are expected to occur is provided in Figure 3.1. Under conditions of Permit M-200 issued for the authorization for return to full operations and use of the TSF, Quantitative Performance Objectives (QPOs) were established for the TSF, some being specific to free water storage in the TSF. Under current authorizations, the TSF is operated with a ‘normal operation free water surplus between 1,000,000 m3 and 1,500,000 m3, and is authorized for temporary detention of water for contingency (e.g., freshet) storage provided that a minimum freeboard of 1.1 m is maintained.

Table 3.2 Water storage conditions at end of 2016

Item 2016 Year End Change from 2015 Year End Springer Pit Elevation (masl) 1,012.24 -13.06 Springer Pit Volume (m3) - Total 6,270,185 -2,449,489 Springer Pit Volume (m3) - Water 2,660,823 -4,779,174 Springer Pit Volume (m3) - Tailings + Interstitial Water 3,609,362 2,329,685 Cariboo Pit Water Elevation (masl) - (a) 29.32 Cariboo Pit Water Volume (m3) - (a) -561,679 TSF Elevation (masl) 952.68 16.01 TSF Volume (m3) - Total 4,218,664 4,216,390 TSF Volume (m3) - Water 1,739,815 1,737,541 Total Free Water Volume (Springer + Cariboo + TSF) 4,400,640 -3,603,311

Total Water Discharged (m3) 6,707,730 - (a) Actively mining in Cariboo Pit. Sump being kept as low as practicable.


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Figure 3.1 Springer Pit water level compared to estimated levels for exfiltration to groundwater (1030 masl) and overtopping (1050 masl)

3.2 Sediment and Erosion Control

As per the MPMC Surface Erosion and Sediment Control Plan, measures conducted in 2016 are summarized below (excluding work being done related to the TSF embankment breach). This plan is required to be updated annually under Permit M-200 and was updated in December 2016. The updated plan was submitted to the MEM in January 2017 as an appendix to the updated Reclamation and Closure Plan (MPMC, 2017a).

3.2.1 Re-vegetation

MPMC recognizes re-vegetation as a critical aspect of site maintenance and restoration. Disturbed areas are grass seeded on an ongoing basis to prevent erosion and invasive species establishment. Soil stockpiles and areas that are unlikely to be disturbed are typically prescribed a native seed mix (Table 3.3). Sites that may be re-disturbed (or where preventing establishment of native species is the primary goal) are typically prescribed an aggressive seed mix (Table 3.3). This mixture grows rapidly in the short term, but dies off allowing the ingress of native species from surrounding areas.

All non-active soil stockpiles on site were inspected for erosion and vegetative cover; non-active stockpiles requiring additional vegetative cover and/or showing signs of erosion were added to the bi-annual (spring and fall) seeding list. Seeding occurs using a native grasses and forbes blend (Table 3.3). In 2016, no new soil stockpiles were established.

Seeding and revegetation took place at numerous locations at the mine site in 2016. It occurred at

900

920

940

960

980

1000

1020

1040

1060

Wat

er L

evel

(mas

l)Springer Pit Water Level

1030m - Groundwater Exfiltration 1050m - Pit Overflow Springer Pit Elevation


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progressive reclamation areas on the East Rock Dump and adjacent Highway to Heaven sites. Seeding took place at disturbed areas around the Water Treatment Plant, the new alignment of the Bootjack Creek Channel, the Main Embankment Soil Stockpile, the New Windrow near the Perimeter Embankment and the Lower SERD Soil Stockpile. MPMC maintains an active Seeding List that serves to track areas that require seeding, their size, description and type of seed.

In addition to seeding ground covers, much of the re-vegetation objectives at the mine include the establishment of woody shrubs and trees. Both conifer and deciduous species are utilized. MPMC recolonizes the importance of appropriate seed source and selection for long-term success and endeavours to use local seed sources. All of the conifer management at the mine is consistent with provincial forest management as governed by the Forest and Range Practices Act. This includes participation in regional silviculture strategies, stocking standards, tree species selection, and seed planning and registration.

Table 3.3 Aggressive and native seed mixes for reclamation

Species % by Weight Aggressive Seed Mix

Dahurian Wildrye 25 Slender Wheatgrass 30 Perennial Ryegrass 15 Timothy 5

Native Seed Mix Mountain Brome 25 Native Red Fescue 10 Rocky Mountain Fescue 14.31 Bluebunch Wheatgrass 25 Blue Wildrye 25 Fireweed 0.014 Big Leaf Lupine 0.68

3.2.2 Upgrades to Water Management System

As described in Section 3.1.2, water management system components are routinely inspected and observations related to erosion are documented and addressed based on assigned priorities. Water management system upgrades carried out in 2016, including those for erosion control purposes, are also outlined in Section 3.1.2.

3.3 Invasive Plant Management

Invasive plant species are managed under MPMC Invasive Plant Management Plan. This plan has been updated and in include as Appendix G. As per this plan, invasive species management activities in 2016


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included:

• Seeding of: soil stockpiles that are not active and new disturbed areas (Section 3.2 as well as new reclamation sites that (unless they covered with freshly stripped soil that is expected to re-vegetate without seeding; Section 11.3.2).

• Use of only high quality grade seed (currently sourced from Premier Pacific Seed, see Table 3.3). At minimum, seed used is of the grade Common No.1 Forage Mixture (or better) or Canada No. 1 Ground Cover Mixture. All of the seed used typically exceeds CFIA and regional standards for presence of noxious weeds.

• Monitoring of soil stockpiles to evaluate presence of invasive species (Section 12.3.2).

• Planting of trees and shrubs in reclamation areas deemed inactive for mining purposes in a timely fashion to encourage rapid canopy cover (Section 11.3.2).

The invasive species currently known to be present at Mount Polley that are listed in the 2016 Regional Strategic Plan are oxeye daisy, Canada thistle, orange hawkweed, yellow hawkweeds (non-native), and scentless chamomile. All of these plants have the priority ranking “3 – Established”, and are common and widespread, with widespread control not currently possible. As such, MPMC’s approach is to manage invasive species at this site such that they do not inhibit reclamation activities, with recognition that all outside sources (for example, cattle, wildlife, wind and water) pose challenges to eradicating invasive plants at the mine site that are widespread in the surrounding areas.

3.4 Waste Management

3.4.1 Storage

During the course of its mining operations, Mount Polley utilizes a variety of chemicals, reagents, and other products. At any one time, the approximate volumes of materials in Table 3.4 could be expected to be on site. In 2016, Mount Polley accepted no mineral-enriched soil from the Vancouver shipping wharves.

Table 3.4 Chemicals and reagents stored at the Mount Polley Mine site

Materials Total Stored On Hand on Jan 1, 2017 PAX(Mill Reagent) 18,000 kg 19,950 kg Lime 100,000 kg 28,984 kg Polyclear 3180M 2,800 kg 4,535 kg Polyfroth W22C 21,000 kg 15,056 kg NaHS 22,000 kg 9,270 kg Methanol 5,000 L 14,400 L

Blasting product values shown in Table 3.5 are the maximum allowable limits that may be stored at any given time at Orica Ltd.’s Mount Polley site and a snap shot of what was on hand on January 5, 2017.


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Table 3.5 Blasting products stored at Orica Ltd.’s Mount Polley site

Blasting Products Maximum Allowable Limits Stored On Hand on Jan 5, 2017

Ammonium Nitrate Emulsion 50 T 50 T Ammonium Nitrate Prill 90 T 45 T Sodium Nitrite 3000 kg 2500 kg Ethylene Glycol 4000 kg 4000 kg

3.4.2 Recycling

MPMC recognizes the value responsible waste management and recycling plays in site waste management practices. Mount Polley continues to recycle used materials including waste oil, scrap steel, batteries, plastic pails, electronic waste, light bulbs and associated fixtures, paper, cardboard, and beverage containers. In 2016, Mount Polley donated the funds generated by its beverage container recycling program to the Big Brothers and Big Sisters of Williams Lake.

Recycling and waste management awareness presentations were given to Mount Polley employees in Q1 2016.

3.4.3 Chemical, Reagent, and Contaminated Waste Disposal

In the course of its ongoing operations, Mount Polley utilizes potentially hazardous chemicals, reagents, and other products that are subject to a waste disposal management plan. In 2016, Sumas Environmental Services Ltd. routinely removed and disposed of these waste products in an environmentally safe manner compliant with all relevant waste management legislation. Products removed include: aerosol cans; contaminated gasoline and diesel; waste oil (in drums); waste oil filters; waste grease fuel or oil soaked rags, debris, and floor dry; and leachable liquid toxic waste, such as glycol/anti-freeze mix. The site waste oil tanks are emptied and the oil removed from site by Load Em’ Up Contracting. MPMC is registered with the MoE under the Hazardous Waste Regulation for generation and temporary storage of these materials.

3.5 Incidents

3.5.1 Spills of Hydrocarbon or Dangerous Goods

All spills of hydrocarbons, coolant, and chemicals are reported to the MPMC Environmental Department. In 2016, there were ten (10) coolant spills and nineteen (19) hydrocarbon spills reported. Of these spills, three (3) were considered reportable to Emergency Management BC as outlined in the Spill Reporting Legislation (refer to Table 3.6). Those spills were given Dangerous Goods Regulation (DGR) number and recorded into the government database. All spills were cleaned up and the materials were removed from site in environmentally safe barrels by Sumas Environmental Services Ltd.

Table 3.6 Hydrocarbon and Dangerous Goods Spills reported to Environmental Department in 2016


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SERDS: Southeast Rock Disposal Site; PAG: Potentially-acid Generating; OCA: Oil Containment Area; NAG: Non-acid Generating;

3.5.2 Water Releases

In 2016, there was one (1) release of mine-affected water, shown in Table 3.7. The water release was reported to Emergency Management BC. No incident report was filed, as the release did not enter any waterways or bodies and was immediately contained.

Table 3.7 Release of mine influenced water reported to Environmental Department in 2016

Date Reported Source Volume (m³) Material Location 23-Jan-16 Tailings Line 100-150 Tailings/Water Service road

Date Reported DGR# Source Volume (L) Material Location

12-Jan-16 30-022 Dozer 20-30 Hydraulic Oil Cariboo Stockpile 19-Jan-16 JLG 15-20 Hydraulic Oil Water Treatment Plant 19-Mar-16 20-014 Excavator 70-90 Hydraulic Oil WHR below Cable Yard 21-Mar-16 Moving enviro drum 40 Coolant Front of Center Bay Pit Shop 22-Mar-16 15-017 Haul Truck 90 Steering Oil SERDS 6-Apr-16 15-021 Haul Truck ~90 Engine Oil Tailings Access Road 7-Apr-16 15-022 Haul Truck unknown Coolant PAG Dump 19-Apr-16 10-008 Drill 50-60 85-140 Gear Oil 1072 Bench Cariboo Pit 1-May-16 Plastic tote ~90 80w90 oil Near Warehouse 13-May-16 16-0420 10-010 Drill ~100 Coolant Above North Bell Dump 18-May-16 Diesel pump ~15-20 Diesel Fuel Warehouse Yard 25-May-16 15-024 Haul Truck ~20-30 Diesel Fuel Fuel Docks (Fuel Farm) 30-May-16 40-082 Grader 30 Diesel Fuel Fuel Docks (Fuel Farm) 1-Jun-16 Used Full Oil Tank <20 Used Oil Underground (OCA) 24-Jun-16 15-011 Haul Truck ~40-50 Coolant NAG/PAG Pad 2-Jul-16 Haul Truck ~12 Coolant Near Cariboo Pit 7-Jul-16 15-011 Haul Truck ~40-60 Coolant Fuel Docks (Fuel Farm) 19-Jul-16 20-021 Excavator ~40 Hydraulic Oil High Grade Stockpile 5-Aug-16 15-077 Haul Truck ~60 Engine Oil Haul Road 19-Aug-16 15-020 Haul Truck ~80-90 Transmission Fluid NAG/PAG Pad 30-Aug-16 992 Loader ~25 Coolant SERDS (by Peterson sorter) 10-Sep-16 16-1659 Diesel Fuel Tank ~190 Diesel Fuel Fuel Docks (Fuel Farm) 16-Sep-16 30-012 Dozer ~50-60 Coolant High Grade Stockpile 19-Sep-16 15-011 Haul Truck ~60 Coolant In-Pit Washroom 28-Sep-16 16-1809 10-008 Drill 145 Compressor Oil Cariboo Pit 2-Oct-16 15-021 80 Hydraulic Oil Stockpile to Fuel Docks 21-Oct-16 15-018 Haul Truck ~40 Coolant Cariboo Pit 5-Dec-16 #4 Fuel Tank ~40 Diesel Fuel Fuel Docks (Fuel Farm)

16-Dec-16 Triple P Steam Truck ~45 Diesel Fuel 1072 ramp to Cariboo


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4 Data Quality Assurance/Quality Control

The purpose of the data quality assurance/quality control (QA/QC) program is to verify the reliability of monitoring data through the implementation of procedures for controlling and monitoring the measurement and analysis process. The QA/QC program provides information for evaluation of the analytical and monitoring procedures, and identification of issues pertaining to possible contamination, both in the field and in the analytical laboratory. The QA/QC program includes:

• Quality assurance (QA): management and technical practices designed to confirm that data were consistent with the objectives of the water quality program

• Quality control (QC): specific data quality objectives (DQOs), statistical assessment of data quality, and corrective measures taken whenever the DQOs were not met

The QA/QC program is conducted at all stages of the sampling program: sample collection, transport, and analysis for all sites including contact water quality sites, surface water quality sites, lakes, and groundwater wells.

4.1 Scheduling

To coordinate sampling and schedule all planned monitoring, as per the CEMP, MPMC prepares internal monthly sampling schedules.

4.2 Field Methods

4.2.1 Sample Collection

Sample collection was consistent with the procedures described in the British Columbia Field Sampling Manual: 2013 – For Continuous Monitoring and the Collection of Air, Air-Emission, Water, Wastewater, Soil, Sediment, and Biological Samples (MoE 2013) and the Mount Polley Quality Assurance/Quality Control Manual (most recent version: MPMC 2017b; herein referred to as the “MPMC QA/QC Manual”). Monitoring procedures for the discharge locations (see Section 6) was consistent with the Metal Mining Technical Guidance for Environmental Effects Monitoring (EEM; Environment Canada 2012), as appropriate.

4.2.2 Field Meters and Monitoring Equipment

Field meters were used to measure dissolved oxygen, conductivity, pH, temperature, turbidity, and water flow. Meters and other field equipment were operated and calibrated following the manufacturers’ instructions and the MPMC QA/QC Manual, which includes specific work methods for the equipment discussed below.


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The conductivity and pH meters used for field analysis of surface water and groundwater were the WTW pH/Conductivity 340i and 3430 handheld multimeters. In-situ turbidity was measured with LaMotte 2020e and 2020we turbidity meters. For measuring field parameters in lakes, YSI EXO multimeters were used. Calibration records were recorded in the calibration logbook, as outlined in the MPMC QA/QC Manual. The YSI EXO multimeter was operated based on the equipment manual and guidance from the supplier (Hoskin Scientific), with general MPMC calibration practices being followed.

Flow measurements were taken using a Sontek FlowTracker Acoustic Doppler Velocimeter. The user measures flow rates across a creek or ditch cross section using the FlowTracker handheld device and the device then calculates the discharge rate based on these measurements and input parameters. The meter has QA/QC standards programed into it, and provides error notifications if these standards are not met. An International Organization for Standardization and statistical U.S. Geology Survey percent error are calculated for each discharge reading based on depth, velocity, width, method, number of stations, and calibration accuracy to evaluate accuracy of the discharge measurement. The dry salt slug injection tracer method used by Watersmith Research Inc (Watersmith) during benchmarking surveys and station assessments in April and August 2016.

The staff gauge benchmarking (calibrating) program occurs annually after freshet as per protocol in the MPMC QA/QC Manual. Station specific details are provided in Section 7.3 and 8.3.1.

Field secchi disk monitoring was undertaken in the lakes (see section 8.6.2 and Appendix K). To promote consistency, secchi disk readings are done whenever possible by the same technician throughout the season with a QA/QC check done annually by a more experienced staff member to evaluate consistency of the readings compared to other years.

Chlorophyll a, phytoplankton and zooplankton samples were collected as per the protocol in the MPMC QA/QC Manual. Chlorophyll a and zooplankton tissue metals analysis were sent to ALS (see section 4.3). Enumeration and species identification of phytoplankton community and zooplankton taxonomy samples were sent to specialized labs, as described in the CEMP (Appendix A).

4.3 Quality Control and Data Quality Objectives

Analytical processing of samples collected by MPMC is conducted by ALS Environmental (ALS) in Burnaby, BC. ALS is a Canadian Association for Laboratory Accreditation Inc. accredited laboratory for the analyses requested. The Laboratory DQOs provided to MPMC by ALS are included as Appendix C. Samples submitted were tracked to verify that laboratory sampling and analysis protocols were followed, including hold times, sample containers, preservatives, detection limits, and approved methodology. Instances in which these protocols were not followed were recorded in the sample tracking sheet. This spreadsheet tracked individual samples and recorded the locations of samples, along with the date, duplicate and blank sample information, sample shipping information, laboratory correspondence, analytical results, and


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potential data integrity issues.

4.3.1 Replicates and Blanks

For water chemistry, QC samples were collected as a component of the monitoring program as per the MPMC QA/QC Manual. A combined QC schedule across the various MPMC monitoring programs is summarized in Table 4.1.

Table 4.1 Water chemistry QC sample frequencies for MPMC monitoring programs

QC Samples Frequency

Duplicate samples 2 per month

Equipment blanks Monthly per piece of equipment (when used)

Trip blanks Monthly

Field blanks Monthly

Filter blanks Quarterly

Deionized (DI) water blanks Annually

Intra-laboratory replicate Annually

4.3.1.1 Field Replicates

The semi-blind replicates are intended to evaluate the QA/QC surrounding the sampling methods. Replicates are prepared by collecting two full sample suites from one location at the same time, one after the other, labelling one with the sampling location name (e.g., E4, HAC-12) and labelling the second sample suite with a replicate name (e.g., ED, HAC-12x). When the results are reported back from the analytical laboratory, all parameters from the replicate and the actual sample are screened to confirm likeness, or potential of sampling error or contamination. The screening process also considers accuracy of the analytical procedures and small-scale natural variations in water quality which may occur over the timescale of collection (approximately 10 minutes). In particular, there is considerable potential for variations in water quality over short-time scales during periods of high sediment loads.

Semi-blind field replicates were compared for the purpose of evaluating the precision of the methods used (i.e. combined precision of field methods, laboratory methods and the environmental variability between the side-by-side samples). A relative percent difference (RPD) is calculated to identify significant differences between the replicate and sample, where the RPD (as %) can be defined as:

RPD (%) = �𝑋𝑋𝑥𝑥 – 𝑋𝑋𝑦𝑦�

𝑋𝑋� × 100

Where 𝑋𝑋𝑥𝑥= the concentration of the original sample 𝑋𝑋𝑦𝑦= the concentration of the blind field duplicate sample

𝑋𝑋� = the average of the original and duplicate samples

The acceptance criteria for RPDs were defined as 1.5x the laboratory RPD criteria, which is summarized in


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Table 4.2. For results less than five times the detection limit, significant differences are identified if the difference of the two results is greater than twice the detection limit. When either sample is less than detection limit, differences are not calculated.

Table 4.2 Duplicate Sample RPD Acceptance Criteria

Analyte Group RPD Acceptance Criterion

Metals 30%

Inorganics 30%

Organics 45%

Other parameters 1.5 x Laboratory RPD

There were twenty-five (25) field replicate samples collected in 2016, as shown in Table 4.3. There were no results for total metals analysis for the groundwater duplicate (e.g. GW12-2b) as total metals are not analyzed for groundwater samples.

Table 4.3 Field replicate sample locations collected in 2016

Date Sampled Location Name

05-Jan-16 HAC-12 HAC-12X

11-Jan-16 W1 WA

04-Feb-16 E18 ER

15-Feb-16 HAD-03 HAD-03X

01-Mar-16 W4a WD

28-Mar-16 QUL-58-B QUL-58X-B

04-Apr-16 E11 EK

06-Apr-16 QUR-1 QUR-1X

04-May-16 W10 WJ

17-May-16 HAC-12 HAC-12X

07-Jun-16 HAC-05a HAC-05aX

07-Jun-16 E19 ES

05-Jul-16 W5 WE

20-Jul-16 QUL-18-50m QUL-18X-50m

02-Aug-16 HAD-03 HAD-03X

04-Aug-16 W12 WL

08-Sep-16 W1 WA

12-Sep-16 QUL-2a-0m QUL-2aX-0m

03-Oct-16 HAC-10 HAC-10X

03-Oct-16 E11a EKA


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Date Sampled Location Name

24-Oct-16 GW12-2b GW12-2bX

08-Nov-16 W20 WT

09-Nov-16 QUL-58-S QUL-58X-S

01-Dec-16 E1 EA

06-Dec-16 EDC-01 EDC-01X

For total metal analyses, the applicable replicate criterion was exceeded for aluminum on three occasions, copper and iron on two occasions. (Table C.1, Appendix C). Some degree of environmental variability can be expected in replicate samples for parameters such as total metals, which are influenced by total suspended solids (TSS).

For dissolved metals analyses, one difference was identified each for aluminum (RPD = 38.0%), cadmium (Difference = 0.000063), manganese (Difference = 0.00023), and lead (Difference = 0.000111) (Table C.2, Appendix C).

For general parameters (ammonia, nitrate, nitrite, sulphate, and TSS), one difference was identified for TSS (Difference = 6.7) (Table C.3, Appendix C).

There was one (1) inter-laboratory replicate collected in 2016. This replicate is intended to evaluate the QA/QC surrounding the analytical laboratory. This replicate was prepared as described above; the sample with the sampling location name is sent to ALS and the sample with the anonymous name is sent to Maxxam Analytics Inc. Maxxam Analytics Inc. is also a Canadian Association for Laboratory Accreditation Inc. accredited laboratory for the analyses requested.

For general parameters (ammonia, nitrate, nitrite, sulphate, and TSS), one difference for the inter-laboratory was identified for ammonia (RPD = 250%) (Table C.4, Appendix C). No other RPDs were identified.

4.3.1.2 Blanks

Trip blanks and field blanks, prepared by the analytical laboratory, are exposed to the same conditions and treatments as the water samples collected and are intended to monitor contamination that may occur during sampling or shipping. Field blanks are opened at one of the sample locations to expose them to the natural environment and trip blanks remain closed at all times. Trip or field blanks are submitted to the laboratory with sample sets for total metals, and nutrient and anion analysis, as well as dissolved organic carbon analysis for field blanks. In 2016, twelve (12) trip blanks were submitted to ALS, as listed in Table 4.4. Turbidity was above the reported detection limit in the trip blank taken on October 5, 2016 and TSS was above the reported detection limit in the trip blank taken on August 2, 2016; both were within five times the reported detection limit so both were determined not to affect the reliability of the data


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(Table C.5, Appendix C).

Table 4.4 Trip blanks sent for analysis in 2016

Date Sampled Area 11-Jan-16 Mine Site

15-Feb-16 Mine Site

01-Mar-16 Mine Site

26-Apr-16 Quesnel Lake

02-May-16 Mine Site

01-Jun-16 Quesnel Lake

05-Jul-16 Mine Site

02-Aug-16 Hazeltine Creek

01-Sep-16 Mine Site

05-Oct-16 Quesnel Lake

01-Nov-16 Mine Site

19-Dec-16 Quesnel River

Twelve (12) field blanks listed in Table 4.5 were submitted to ALS in 2016. Turbidity was above the reported detection limit in the field blank taken on October 5, 2016; it was within five times the reported detection limit so was determined not to affect the reliability of the data (Table C.5, Appendix C).

Table 4.5 Field blanks sent for analysis in 2016

Date Sampled Area

25-Jan-16 Quesnel Lake

04-Feb-16 Mine Site

10-Mar-16 Quesnel River

05-Apr-16 Mine Site

17-May-16 Hazeltine Creek

01-Jun-16 Mine Site

20-Jul-16 Quesnel Lake

04-Aug-16 Mine Site

08-Sep-16 Quesnel River

04-Oct-16 Mine Site

15-Nov-16 Hazeltine Creek

01-Dec-16 Mine Site

Filter blanks are prepared by filtering deionized (DI) water and submitting for dissolved metals analysis. Four (4) filter blanks were submitted in 2016. All parameters analyzed in the filter blanks were below


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reported detection limits as expected (Table C.5, Appendix C).

DI water blanks are prepared by submitting a full sample suite (minus dissolved metals since filter blanks are prepared) of DI water. One (1) DI water blank was submitted in 2016; all parameters were below reported detection limit as expected (Table C.5, Appendix C).

When conducting lake water quality sampling, an equipment blank sample is taken with the Van Dorn (VAN2) or Kemmerer (KEM1) sampler monthly during each sampling program, such as spring overturn monitoring. Equipment blanks are submitted to the laboratory for full sample suites (minus dissolved metals since filter blanks are also prepared). Eleven (11) equipment blanks were taken in 2016, as shown in Table 4.6. VAN2 was not used in 2016, so only KEM1 blanks were taken. The lake sampling program in 2016 commenced in January and ended in November (see Sections 6.2 and 8.2).

Table 4.6 Equipment blanks taken in 2016

Date Sampled Equipment 20-Jan-16 KEM1

23-Feb-16 KEM1

29-Mar-16 KEM1

06-Apr-16 KEM1

05-May-16 KEM1

07-Jun-16 KEM1

11-Jul-16 KEM1

01-Aug-16 KEM1

05-Sep-16 KEM1

05-Oct-16 KEM1

09-Nov-16 KEM1

Turbidity, total aluminum, total barium, total lead, and total manganese were all above detection limits in one or more of the equipment blanks (Table C.5, Appendix C). A summary of results for the KEM1 blanks that are greater than five times the detection limit is provided in Table 4.7.

Table 4.7 Summary of KEM1 blank results that are 5x detection limit

Date Sampled Parameter Detection Limit Result

06-Apr-16 Total Lead (mg/L) 0.000050 0.000886

05-May-16 Total Lead (mg/L) 0.000050 0.00063

07-Jun-16 Total Aluminum (mg/L) 0.0030 0.0169

07-Jun-16 Total Barium (mg/L) 0.000050 0.000277

11-Jun-16 Turbidity (NTU) 0.10 0.51


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05-Sep-16 Total Lead (mg/L) 0.000050 0.000392

09-Nov-16 Total Lead (mg/L) 0.000050 0.000577

4.4 Data Quality Review and Data Management

A data quality review was conducted for results, including screening of laboratory QA/QC data, sample integrity issues, detection limits achieved, and metadata accuracy, as well as potential outliers/extreme values. This information was catalogued in the MPMC sample tracking spreadsheets described in Section 4.3.

MPMC uses MonitorPro (MP-5 database) by EHS Data Limited for data management. Water, soil, sediment, and tissue chemistry data as well as weather station downloads were uploaded into the MP-5 database using files generated by the analytical laboratory. Accompanying field data was manually entered and uploaded into the MP-5 database. Original laboratory-produced results files are filed on the MPMC network according to month, year, and date, and are linked to the data stored in the MP-5 database. Sample names, dates, and times are cross-referenced with the MPMC sample tracking sheet before final upload to the database and field data undergo a QC screening prior to upload. Parameter restrictions are in place in the MP-5 database to reduce the likelihood of a typographical or laboratory reporting error being uploaded. Any errors identified by the MP-5 database underwent further audit before final acceptance.

Non-chemistry data, including toxicity testing results, benthic invertebrate and plankton taxonomy data, and hydrology data (logger downloads and FlowTracker exports) are filed according to year and site on the MPMC network.

4.4.1 Rating Curve Equation

Stage-discharge rating curves were developed for the hydrometric stations by relating manual water level and stream discharge measurements acquired by MPMC (velocity based measurements using a SonTek FlowTracker) and WaterSmith (dry salt slug injection tracer method [Hudson and Fraser, 2005]). The rating curves were fit statistically [R Development Core Team, 2010] using a nonlinear least-squares regression model of the following generic form:

log10(Q) = a + b log10(H - c)

where 𝑄𝑄 is the discharge, m3/s, 𝐻𝐻 is stage (m), a, b, and c are regression coefficients.

Vented pressure transducers (model INW PT2x) and barologgers and leveloggers (models Solinst 3001)


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were installed at various sites to continuously monitor water levels at 10 minute intervals during non-freezing months. According to the manuals, INW PT2x (Seametrics 2016) and Solinst 3001 levelogger (Solinst 2013) sensors maintain a sensor accuracy of ±0.25% and ±0.05% respectively. A linear relation was developed between the automatically recorded pressure and the manual stage gauge readings at each station to create stage-pressure curves. Stage values estimated from pressure readings using the stage-pressure rating curve equation can then be substituted into the rating curve equation for discharge estimates. This results in an estimation of a creek’s stage and discharge throughout the monitoring season. Any estimation above the highest measured stage and discharge is considered an extrapolation.

Statistical analysis of the manual gauge readings will be reported in the appropriate sections below and in Appendix J.

Calibration measurements (taken by a dry salt slug injection tracer method) and benchmarking surveys of hydrological stations were conducted by Watersmith in 2016. Details of each visit will be reported in the appropriate sections below.

Routine monitoring incorporates inspections of equipment, including stilling wells and loggers (e.g., to identify sedimentation inside the stilling well, debris build up in logger ports). Identification of potential station changes or issues also occurs through data analysis when data are inconsistent or unusual in comparison with previously collected data.


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5 Mine Site Environmental Monitoring

5.1 Contact Water Chemistry

Contact water sampling and analysis was conducted as outlined in sub-sections 2.6 and 3.1 of Permit 11678 (Appendix A). Surface sampling is outlined as per section 4.1 in the CEMP found in Appendix A of this report. Refer to Section 3 for a discussion of field sampling equipment and methodology.

This section contains data for effluent site with a prefix letter “E”, and frequency are summarized in Table 5.1. Sample locations are shown in Appendix A. The effluent site listed in this section, E11, is contained within the site and treated and released as per sub-section 1.2 of the Permit 11678 (Appendix A). As per sub-section 4.1.2 of the CEMP (Appendix A), legacy sites such as East and West Main Toe Drains, Main Embankment Seepage Pond (E4) and Central Collection Sump (E18) that no longer discharge into Hazeltine or Edney Creek have been removed. Note that E19, the Perimeter Embankment Till Borrow Pond (PETBP), and E11a (Springer Pit supernatant) are included as a surface contact water sites in the CEMP but will be discussed in the discharge system and monitoring section of the annual report (see Section 6). All other contact water sites that are collected under MEM Permit M-200 are described in Section 12.4.2.

Table 5.1 Sampling events in 2016 at contact water quality sites

Site Site Identifier (EMS No.)

Frequency

Permit Requirement Actual

E1 E225309 Monthly (a) 2 E11 E302090 Monthly (b) 8 (c)

(a) When reclaim water was sourced from the TSF (b) Monthly commencing in May 2016 (c) Weekly sampling required before April 28, 2016 was under short-term water discharge plan; results from these

samplings events (i.e., prior to April 28, 2016) are reported in Section 6.2 Discharge Monitoring and are not included here.

Samples were submitted to ALS for analysis of:

• Physical parameters (pH, turbidity, TSS, total dissolved solids, and hardness); • Anions and nutrients (alkalinity, sulphate, total nitrogen, nitrate, nitrite, ammonia, chloride,

fluoride, total phosphorus, dissolved phosphorus, and ortho-phosphorus); • Organics (dissolved organic carbon); and • Total and dissolved metals (metals suite as listed in CEMP (Appendix A).

Thirteen (13) parameters of interest (POIs) were identified in the Chemical Characterization of the Proposed Effluent for Discharge to Hazeltine Creek (Knight Piésold Ltd 2009) based on site geochemistry and historical characteristics, as well as existing and projected waste and water management practices. To


35

monitor changes in the effluent surface water quality, in the subsequent sections, these POIs were reviewed for each water quality site over time:

• Physical Parameters: Hardness, TSS; • Anions: Chloride, Sulphate; • Nutrients: Nitrate, Total Phosphorus; and • Metals: Dissolved Aluminum, Total Cadmium, Total Copper, Total Molybdenum, Total and

Dissolved Iron, Total Selenium.

Results for POI concentrations for the effluent sites are noted and included in tabular format in Appendix D. Note that results below method detection limit (MDL) are represented as half (0.5x) the MDL in statistical calculations and graphs.

Water quality data, including summary statistics (number, minimum, maximum, mean, standard deviations, and method detection limit) are provided in Appendix D.

5.1.1 Site E1 – Tailings Supernatant (E225309)

Tailings deposition into the TSF recommenced in June 2016. The reclaim barge (location of E1) was floating and reclaim water was being sourced by November 22, 2016, so sample collection began at this time. This location was sampled two times in 2016 which is not sufficient data to review and analyze. This site will now be monitored monthly and discussed in future reports.

5.1.2 Site E11 – Springer Pit Sump (E302090)

The Springer Pit Sump was sampled eight (8) times in 2016 after it was replaced by sample location E11a (see Section 6.2 for results before April 28, 2016). Samples for E11 in 2016 are not representative of the pit lake water quality, rather of runoff water coming down the ramp to the pit. Therefore no further discussion will be included in this section. Tailings deposition into the Springer Pit ceased on June 27, 2016. Graphs for a subset of parameters are provided in Appendix D.

5.2 Seep Sampling

Seep sampling is conducted under MEM Permit M-200 and is summarized in Section 12.4.2.

5.3 Groundwater Monitoring

5.3.1 Program Background

In 1995, groundwater monitoring wells (series 95) were installed in the vicinity of the open pits and the Mill Site. One of these wells (95R-5) still exists and remains part of the sampling program. In 1996, in order


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to monitor aquifers in both surficial deposits and bedrock, the MoE requested the establishment of additional monitoring wells downslope of the pit, existing RDS, and TSF. In conjunction with these ‘downslope’ wells, background wells were established upslope of any potential impacts by mining activities. This resulted in nine (9) groundwater monitoring wells being established in 1996 (series 96). Six (6) of these sites were multi-level, consisting of “A” (deep) wells and “B” (shallow) wells, while the remaining three (3) sites monitor a single depth. A commitment to install three (3) additional pairs of multi-level monitoring wells along the southeast embankment of the TSF was made in 1996. These wells were subsequently installed in 2000.

In 2005, GW05-01 was established to capture groundwater moving from Polley Lake towards the Wight Pit and pump it back into Polley Lake.

In 2011, to monitor potential impacts of newly disturbed areas, two (2) additional pairs of multi-level monitoring wells were established below the Temporary NW PAG Stockpile, and below the SERDS on the Polley Lake Road.

In 2012, MPMC retained AMEC to complete a site hydrogeological assessment. Based on AMEC’s recommendations, five (5) pairs of monitoring wells were installed in 2012 and well 95R-4 was decommissioned. The full report was included in the 2012 Annual Environmental and Reclamation Report.

In 2014, a domestic water well was drilled at the new Orica Site. Monitoring of this well commenced in 2014 and results will act as reference for groundwater upstream of the TSF. This replaces wells GW96-5a/b that were deactivated due to TSF expansion in 2013.

In 2015, MPMC contracted Golder to conduct hydrogeological investigations near the Springer Pit in support of the Mount Polley Mine: Short Term Effluent Discharge Technical Assessment Report in Support of an Effluent Permit Amendment, which was developed by Golder (2015a). Two (2) pairs of multi-level wells were installed to monitor the seepage conditions of the Springer Pit Lake. In addition to the new wells, monitoring of GW12-2a/b was increased to monthly. More information is presented in the 2015 Annual Environmental and Reclamation Report (MPMC 2015b).

Under Section 3.9 of Permit 11678 (Appendix A), MPMC is required to conduct a “groundwater monitoring program review, including but not limited to sampling, well locations, site water balance, interpretation of data trends and possible environmental impacts, and suitable recommendations” every three (3) years. The last program review was carried out by Golder for March 31, 2016, as required. The review consists of two (2) reports: a review of the areas adjacent to the Springer Pit, Cariboo Pit, and the Wight Pit (Golder 2015b; also submitted in the 2015 Annual Environmental and Reclamation Report); and a review of the TSF and SERDS areas (Appendix E). This first report built on previous recommendations made during preliminary closure seepage assessments for the Springer-Cariboo and Wight Pits (Golder 2015c and 2015d, respectively). Golder found that “with the exception of the area surrounding the Wight


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Pit, the location of monitoring wells and monitoring frequency are considered sufficient for monitoring of groundwater conditions at the mine site during closure”. As per Golder’s recommendations two (2) multi-level groundwater monitoring wells were installed between the Wight Pit and Polley Lake in 2016 (GW16-7 and GW16-8). For monitoring of seepage quality and quantity at closure, Golder also recommended installation of one (1) multi-level groundwater monitoring well between the Cariboo Pit and Bootjack Lake; installation of this nested well was completed in 2016 (GW16-6). The new wells were installed late in 2016 and will be included in the monitoring program for 2017.

The second report included a number of recommendations. A summary of these recommendations, along with actions taken by MPMC to address the recommendations (Appendix E), is as follows:

• Installation of four (4) additional pairs of multi-level monitoring wells to improve the spatial resolution of monitoring down gradient of the TSF. These wells were installed in 2016 (GW16-2, GW16-3, GW16-4, and GW16-5).

• Installation of one (1) pair of multilevel monitoring wells down gradient of the SERDS, closer to the facility to increase the rate of detection in the event of seepage to groundwater. These nested wells were installed in 2016 (GW16-1). The GW16-1 wells replace GW11-2 because GW11-2 consistently exhibits elevated pH and electrical conductivity (EC).

• Reduce the sampling frequencies of TSF bedrock monitoring wells showing stable chemistry (GW96-1a, GW96-3a, GW96-4a, GW00-1a, GW00-2a, and GW00-3a) from bi-annually to annually. This change has been implemented under the CEMP (Appendix A).

• Increase the frequency of groundwater level monitoring to quarterly at all TSF monitoring wells. This change has been implemented under the CEMP (Appendix A).

• Conduct water level monitoring at all wells within a shorter time period (e.g., a few days) to improve the accuracy of groundwater flow analysis. This change has been implemented under the CEMP (Appendix A).

The locations of all groundwater monitoring wells installed in 2016 are presented in Appendix A. The next groundwater monitoring program review will be completed by March 31, 2019.

5.3.2 Monitoring Program

Objectives of the groundwater-monitoring program include the following (Knight Piésold Ltd, 1996):

• To determine the direction and volume of groundwater flow from the mine site and other disturbed areas to receiving waters;

• To identify the locations of surficial and deep groundwater aquifers underlying the mine site and their points of discharge to surface water;

• To establish background groundwater quality in aquifers prior to mine development; and


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• To calculate seepage and groundwater contamination dilution ratios in surface receiving waters in order to minimize impacts.

Appendix A includes the locations of all monitoring wells, and Table 5.2 provides the depth, elevation and location information for each well, as well as the current monitoring frequency under the CEMP (Appendix A), 2016 sampling events, and years sampled.

All sampling was carried out as per the CEMP (Appendix A), with the exception of GW12-5b. Due to well damage early in the year, the spring sampling event was missed. The well was repaired and sampled in the fall.

The calibration, sampling, filtering, preservation, and shipping procedures outlined in the Quality Assurance / Quality Control Manual (MPMC 2017b) and the British Columbia Field Sampling Manual: 2013 – For Continuous Monitoring and the Collection of Air, Air-Emission, Water, Wastewater, Soil, Sediment, and Biological Samples (MoE 2013) were followed in the monitoring program. In situ pH, temperature and specific conductance were measured at the time of sampling using a WTW multimeter. Refer to Section 4 for additional information on site sampling protocols.

Prior to drawing water from each well for purging and/or sampling, the phreatic (static) water level is measured and recorded. Results are presented in Section 5.3.3. Samples are collected and then submitted to ALS for water chemistry analysis, including: physical parameters (conductivity, pH, and hardness); anions and nutrients (alkalinity, chloride, fluoride, sulphate, ammonia, nitrate, nitrite, nitrogen, and phosphorus); and dissolved metals.

To monitor changes in groundwater quality in the subsequent sections, nine (9) key POIs are examined for each well over time:

• Physical Parameters: hardness

• Anions: sulphate

• Nutrients: nitrate

• Dissolved Metals: aluminum, arsenic, cadmium, copper, molybdenum, selenium

These POIs were identified in the Chemical Characterization of the Proposed Effluent for Discharge to Hazeltine Creek (Knight Piésold Ltd 2009) based on site geochemistry, concentrations relative to current guidelines and regulations, historical water quality trends, and existing and projected waste and water management practices.

In Golder’s (Appendix E) review electrical conductivity, pH, calcium, magnesium, sodium, barium, manganese, and strontium were also looked at as potential indicators of tailings seepage release to the groundwater environment surrounding the TSF. These other indicator parameters are included in the


39

groundwater quality results for the wells included in Golder’s (Appendix E) review.

All groundwater results are presented in Appendix F of this report. This includes data in tabular form for each site, and graphs of the POIs at each site where changes were noted. Results below MDL are represented as half (0.5x) the MDL in statistical calculations and graphs.


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Table 5.2 Monitoring well depth, elevation, location, and sampling information

Well ID EMS Code Well Depth (m) Elevation Northing Easting Monitoring Frequency (a) 2016 Sampling Events Years Sampled 95R-5 E229695 79.2 977.69 582 3790.66 59 3687.50 Bi-annually 2 1995 - 2016 GW96-1a E229679 59.0 927.89 581 9939.06 59 5415.82 Annually 1 (b) 1998 - 2016 GW96-1b E229680 38.72 927.81 581 9935.22 59 5416.16 Bi-annually 2 1998 - 2016 GW96-2a E229681 54.88 931.42 581 9449.92 59 6065.40 Bi-annually 2 1998 - 2016 GW96-2b E229682 35.67 931.42 581 9447.08 59 6074.73 Bi-annually 2 1998 - 2016 GW96-3a E229683 52.59 912.06 581 8308.97 59 5768.75 Annually 2 1998 - 2016 GW96-4a E229685 24.7 940.56 581 8164.58 59 5147.94 Annually 1 (b) 1998 - 2016 GW96-4b E229686 7.16 940.46 581 8162.87 59 5151.26 Bi-annually 2 1998 - 2016 GW96-7 E229690 14.12 1021.32 582 1520.53 59 2983.23 Annually 1 1998 - 2016 GW00-1a E242385 21.03 939.18 5818476 594368.01 Annually 1 (b) 2000 - 2016 GW00-1b E242385 10.58 939.13 5818475.85 594371.26 Bi-annually 2 2000 - 2016 GW00-2a E242387 21.55 943.4 5818337.53 594651.75 Annually 1 (b) 2000 - 2016 GW00-2b E242386 10.64 943.32 5818336.4 594657.58 Insufficient Flow 0 (c) 2000 - 2010 GW00-3a E242389 24.29 943.07 5818238.13 594896.38 Annually 1 (b) 2000 - 2016 GW00-3b E242388 13.66 943.22 5818237.65 594899.99 Bi-annually 2 2000 - 2016 GW05-01 E258923 593027 5825267 Quarterly 4 (d) 2005 - 2016 GW11-1a E291219 15.85 1030 5823845 590766 Bi-annually 2 2011 - 2016 GW11-1b E291211 8.23 1030 5823845 590766 Bi-annually 2 2011 - 2016 GW11-2a E291212 29.4 938 5821020 594910 Bi-annually 2 2011 - 2016 GW11-2b E291213 14.3 938 5821020 594910 Bi-annually 2 2011 - 2016 GW12-1a E291969 99.6 991.6 5824612.572 590420.673 Bi-annually 2 2013 - 2016 GW12-1b E291970 24.4 991.4 5824617.366 590420.534 Bi-annually 2 2013 - 2016 GW12-2a E291971 100.6 1035.4 5823179.943 591154.532 Bi-annually/Monthly 12 (e) 2013 - 2016 GW12-2b E291972 30.2 1035.4 5823176.641 591153.566 Bi-annually/Monthly 12 (e) 2013 - 2016 GW12-3a E291973 99.7 1039.2 5822098.478 592147.958 Bi-annually 2 2013 - 2016 GW12-3b E291974 16.1 1039.1 5822101.875 592147.584 Bi-annually 2 2013 - 2016 GW12-4a E291976 100.6 989.9 5822894.269 594117.413 Bi-annually 2 2012 - 2016 GW12-4b E291977 36.3 990.1 5822890.944 594115.972 Bi-annually 2 2013 - 2016 GW12-5a E291978 100.4 965.3 5824582.252 593197.113 Bi-annually 2 2012 - 2016


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Well ID EMS Code Well Depth (m) Elevation Northing Easting Monitoring Frequency (a) 2016 Sampling Events Years Sampled GW12-5b E291979 12.7 966.2 5824568.66 593199.483 Bi-annually 1 (f) 2012 - 2016 GW14-1 E301973 159.7 1036.3 593765.9 5819742.9 Quarterly 4 2014-2016 GW15-1a E303210 105.9 1049.4 593235.416 5821296.28 Monthly 12 (e) 2015-2016 GW15-1b E303211 44.85 1048.8 593229.115 58251295.6 Monthly 12 (e) 2015-2016 GW15-2a E303212 97.66 1035.3 593063.189 5821299.76 Monthly 12 (e) 2015-2016 GW15-2b E303213 46.6 1035.5 593068.695 5821297.62 Monthly 12 (e) 2015-2016

(a) Monitoring frequency as per MPMC 2016 CEMP (Appendix A) (b) SWL is taken quarterly (c) SWL is taken twice a year (d) Pumping terminated as of June 2010. Re-sampling commenced 2012. (e) SWL is taken daily (f) Only sampled once due to well damage in spring


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5.3.3 Groundwater Static Water Levels

Graphs comparing the SWL results for site groundwater wells in 2016 with historic levels are presented in Appendix F.

95R-5: The SWL fluctuated between 0.0 m and 2.0 m from 1997 until 2008, when levels dropped to 4.5 m. The SWL remained between 3.0 m and 5.0 m from 2008 to 2015 and increased above 3.0 m in 2016.

GW96-1a/b: In 2016, SWLs at these sites remained consistent with previous years.


GW96-3a: The SWLs at GW96-3a have fluctuated between 0 m and 18.0 m since 1999. In 2016, the SWLs were between 4.0 m and 6.0 m.


GW96-7: Levels generally fluctuate between 3.0 m and 7.0 m which is consistent with monitoring since 2008.

GW00-1a/b: SWLs in these wells have historically mirrored each other, fluctuating annually and seasonally between 0.5 m and 3.0 m. Since 2007, levels have remained above 1.5 m, and since 2012 have stabilized between approximately 1.0 m and 2.0 m. In 2016, SWLs at these sites remained consistent with previous years.

GW00-2a/b: SWLs in these wells have historically mirrored each other and shown seasonal fluctuations. In 2016, SWLs at these sites remained consistent with previous years.

GW00-3a/b: Prior to 2006, the SWLs in GW00-3a and GW00-3b typically fluctuated between 4.0 m and 6.0 m. Since 2006, SWLs in both wells have mirrored each other, showing seasonal fluctuations between 3.0 m and 5.0 m. In 2016, SWLs at these sites remained consistent with previous years.

GW11-1a/b: In 2011 and 2012 the SWL in GW11-1a was at ground level. In 2013 it dropped to approximately 1.1 m. In 2014-2015, it rose to 0.3 m. In 2016, the SWLs were stable at 0.0 m. The SWL in GW11-1b increased from 3.6 m in 2011 to approximately 3.0 m in 2012 and 3.2 m in 2013 and remained in this range in 2014. In 2015, the SWL dropped in the spring to approximately 3.7 m but stabilized around 3.0 m in the fall. In 2016, SWLs at GW11-1b remained constant at 3.0 m.

GW11-2a/b: SWLs in these wells mirror each other and show seasonal fluctuations. In 2016, SWLs at


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these sites remained consistent with previous years.

GW12-1a/b: SWLs in these wells mirror each other and show slight seasonal fluctuations (between 4.0 m and 6.0 m). In 2016, SWLs at these sites remained consistent with previous years.

GW12-2a/b: SWLs in these wells have increased since April 2015, reaching peak SWLs at both sites in July 2016. SWLs decreased in August 2016 and continued to drop in fall/winter 2016.

GW12-3a/b: In 2016, the SWLs in GW12-3a and 3b have remained stable between 4.0 and 5.0 m.

GW12-4a/b: In 2016, the SWLs in GW12-4a and 4b have remained stable at approximately 23.0 m and 13.0 m respectively.

GW12-5a/b: The SWL in GW12-5a has fluctuated between 5.5 m and 8.0 m since commission due to spring and fall conditions. In 2016, the SWLs peaked at 4.7 m in spring and decreased to 7.5 m in fall. The SWL in GW12-5b has steadily decreased from 5.0 m in 2013 to about 6.3 m in 2015. In 2016, the SWLs were stable at approximately 5.0 m.

GW15-1a/b: Since September 2015, SWLs at GW15-1a and 1b have steadily increased and peaked at approximately 13.5 m in June 2016. SWLs steadily decreased throughout late 2016.

GW15-2a/b: Since September 2015, SWLs at GW15-2a and 2b have steadily increased. Both wells peaked in April/May 2016, and started continually decreasing throughout late 2016.

5.3.4 Groundwater Quality Results

The following groundwater results were reviewed by Golder and a review of the groundwater characterization of the areas adjacent to the TSF and SERDS was completed in March 2016 (Appendix E). An updated memo summarizing all of the groundwater information is expected in early 2017.

5.3.4.1 95R-5 (Lower SERDS Well)

95R-5 is located along the old Polley Lake Forest Service Road below the Northeast Zone (NEZ) Dump. In reviewing the water quality data from this well, it should be noted that the static level dropped significantly in 2008 (refer to Section 5.3.3). Notable observations in POI results were:

Hardness: Increased from approximately 190 mg/L in 2005 to a historic maximum of 782 mg/L in October 2010. Since 2010, hardness levels have fluctuated seasonally, with a range of 550mg/L in 2014 to approximately 680 mg/L in 2016.


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Sulphate: Increased from the historic range of approximately 20 to 40 mg/L since 2004 to a historic maximum of 531 mg/L in October 2010. Since 2010, sulphate levels have decreased, with an increase in 2015 to 140mg/L and 152mg/L in June and October, respectively, and increased again to approximately 160 mg/L in 2016.

Arsenic: Starting in 2013, arsenic increased from historic levels of less than 0.0015 mg/L to a historic maximum of 0.0082 mg/L in September 2016.

Molybdenum: Molybdenum levels have steadily decreased from approximately 0.03 mg/L in the late 1990s. In 2016, levels were 0.0085 mg/L and 0.00766 mg/L in April and September 2016, respectively.

For the remaining POIs, 2015 values were similar to or below historic results, and any fluctuations or spikes in previous years have discontinued.

5.3.4.2 GW96-1a (TSF North Well – Deep)

GW96-1a is located downslope of the Perimeter Embankment Seepage Collection Pond (PESCP). Notable observations in POI and other indicator parameter results were:

Nitrate: Increased from historic levels of less than 0.01 mg/L to 0.0482 and 0.0355 mg/L in May and October 2014, respectively. In June 2015, the nitrate level decreased to below MDL (0.002 mg/L) and then increased in May 2016 to 0.0184 mg/L.

Molybdenum: Fairly stable at or below 0.03mg/L between 2010 and 2014. In 2016, the concentration increased to 0.0369mg/L in May.

Cadmium: Increased from historic levels of less than 0.00001 mg/L to 0.000341 mg/L in May 2016.

For all of other POIs and other indicator parameters, 2016 values were similar to historic levels, and any fluctuations or spikes in previous years have stabilized.

5.3.4.3 GW96-1b (TSF North Well – Shallow)

GW96-1b is located downslope of the PESCP. Notable observations in POI and other indicator parameter results were:

Hardness: Hardness has steadily increased since 1998 from 32.9 mg/L to 64.7 mg/L in June 2015. It increased to 181mg/L in September 2016.

Nitrate: Increased from below MDL (0.0050 mg/L) since 2010 to 0.0231 mg/L in September 2016.


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Calcium: Increased from 11.6 mg/L in May 2016 to 38.3 mg/L in September 2016.

Magnesium: Increased from 8.6 mg/L in May 2016 to 20.7 mg/L in September 2016.

Sodium: Decreased from 59.8 mg/L in May 2016 to 25 mg/L in September 2016.

Barium: Increased from 0.0398 mg/L in May 2016 to 0.0675 mg/L in September 2016.

For all remaining POIs and other indicator parameters, 2016 values were similar to or below historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.4 GW96-2a (TSF East Well – Deep)

Groundwater monitoring well GW96-2a is located approximately 900 metres (m) southeast of the GW96-1 monitoring wells and was commissioned to monitor potential groundwater effects from the TSF on Hazeltine Creek. Notable observations in POI and other indicator parameter results were:

Hardness: Decreased from 194 mg/L in May 2016 to 63.1 mg/L in September 2016.

Molybdenum: Increased from 0.00278 mg/L in May 2016 to 0.00924 mg/L in September 2016.

Calcium: Decreased from 41.4 mg/L in May 2016 to 11.6 mg/L in September 2016.

Magnesium: Decreased from 21.9 mg/L in May 2016 to 8.31 mg/L in September 2016.

Sodium: Increased from 23.6 mg/L in May 2016 to 62.7 mg/L in September 2016.

Barium: Decreased from 0.0658 mg/L in May 2016 to 0.0396 mg/L in September 2016.

For all remaining POIs and other indicator parameters, 2016 values were similar to or below historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.5 GW96-2b (TSF East Well – Shallow)

GW96-2b is located approximately 900 m southeast of the GW96-1 monitoring wells and was commissioned to monitor potential groundwater effects from the TSF on Hazeltine Creek. Notable observations in POI and other indicator parameter results were:

Hardness: Hardness has fluctuated over time from approximately 220 mg/L to 260 mg/L, but increased in 2015, reaching a historic maximum of 392 mg/L in June 2015. In 2016, hardness has slightly decreased to


46

365 mg/L and 344 mg/L in May and September, respectively.

Sulphate: Sulphate has steadily increased from approximately 6 mg/L in 2003 to 131 mg/L in October 2014. It increased significantly to 303 mg/L in October 2015. In 2016, sulphate decreased to 258 mg/L and 289 mg/L in May and September, respectively.

Arsenic: Arsenic has remained slightly elevated above baseline (approximately 0.0013 mg/L) since 2008, with levels fluctuating between 0.0015 mg/L and 0.0018 mg/L.

Molybdenum: Has gradually increased above baseline (approximately 0.004 mg/L). Levels reached a historic maximum of 0.119 mg/L in 2015. In 2016, molybdenum slightly decreased to 0.0915 mg/L and 0.111 mg/L in May and September, respectively.

EC: EC increased in October 2015 to a historic maximum of 861 µS/cm. In 2016, EC decreased to 813 µS/cm and 774 µS/cm in May and September, respectively.

Calcium: Increased to a historic maximum in June 2015 to 96.1 mg/L. Calcium then decreased to 90.2 mg/L and 85.9 mg/L in May and September 2016.

Magnesium: Increased to a historic maximum in June 2015 to 36.9 mg/L and then slightly decreased again to 34 mg/L and 31.6 mg/L in May and September 2016.

Sodium: Sodium has steadily increased from 11.3 mg/L in 1998 to a historic maximum of 42.7 mg/L in September 2016.

Manganese: Increased to a historic maximum in June 2015 to 0.345 mg/L and then decreased to 0.213 mg/L and 0.291 mg/L in May and September 2016, respectively.

Strontium: Increased to a historic maximum in June 2015 to 0.721 mg/L and then decreased to 0.638 mg/L and 0.69 mg/L in May and September 2016, respectively.

For the remaining POIs and other indicator parameters, 2016 values were similar to historic results, and any spikes or fluctuations in previous years have stabilized.

5.3.4.6 GW96-3a (TSF Southeast Well – Deep)

GW96-3a is located adjacent to MESCP, downstream of the TSF. Throughout the monitoring period, many parameters have exhibited constant fluctuations including sulphate, aluminum, arsenic, cadmium, copper, and molybdenum.


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Selenium: Has been stable since 2011 at below MDL (0.0005 mg/L) and has further decreased to 0.000093 mg/L and 0.000101 mg/L in May and September 2016, respectively. This decrease is potentially a result of better laboratory methods.

For POIs and other indicator parameters, 2016 values were within historic fluctuations, and any spikes in previous years have stabilized.

5.3.4.7 GW96-4a (TSF Southwest Well – Deep)

GW96-4a is located downslope of the South and Main TSF Embankments. Notable observations in POI and other indicator parameter results were:

Hardness: Since 2012 levels have increased to above previously observed fluctuations (85 to 110 mg/L) to a historic maximum of 138 mg/L in April 2016.

Nitrate: Starting in 2012 levels increased from baseline of approximately 0.01 mg/L to a historic maximum of 0.134 mg/L in June 2015. In 2016, levels decreased slightly to 0.113mg/L in April 2016.

Sulphate: Levels were stable at approximately 2.5 mg/L from 2005 through 2011, and then began increasing to a historic maximum of 35.8 mg/L in April 2016.

EC: Has been steadily increasing since 2011 from 296 µS/cm to a historic maximum of 388 µS/cm in April 2016.

Calcium: Since 2012 levels have increased to above previously observed fluctuations (19 to 24 mg/L) to a historic maximum of 34.10 mg/L in April 2016.

Magnesium: Since 2011 levels have increased to above previously observed fluctuations (8 to 10 mg/L) to a historic maximum of 12.80 mg/L in April 2016.

For all other POIs and other indicator parameters, 2016 values were similar to or below historic results, and fluctuations or spikes in previous years have stabilized.

5.3.4.8 GW96-4b (TSF Southwest Well – Shallow)

GW96-4b is located downslope of the South and Main TSF Embankments. Notable observations in POI and other indicator parameter results were:

Hardness: Hardness has steadily increased yearly from approximately 180 mg/L in 1996 to a historic maximum of 564 mg/L in April 2016 and then slightly decreased to 537 mg/L in September 2016.


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Nitrate: Nitrate has increased from below MDL (0.005 mg/L) in 2003 to a historic maximum of 0.934 mg/L in June 2015. It decreased to 0.339 mg/L and 0.132 mg/L in April and September 2016, respectively.

Sulphate: Sulphate has increased from approximately 2 mg/L in 1996 to a historic maximum of 351 mg/L in April 2016.

EC: EC has steadily increased since 2010 from 445 µS/cm to a historic maximum of 1040 µS/cm in April 2016.

Calcium: Has steadily increased since 2010 from 59.5 mg/L to a historic maximum of 152 mg/L in April 2016.

Magnesium: Has generally increased over the years, with the lowest level in 2009 (11.8 mg/L). It increased to a historic maximum of 44.7 mg/L in April 2016, then dropped slightly to 43 mg/L in September 2016.

Sodium: Has steadily increased since 2010 from 9.97 mg/L to 23mg/L in September 2016.

Manganese: Levels reached a historic maximum of 0.276 mg/L in October 2015 and then decreased to 0.234 mg/L and 0.222 mg/L in April and September 2016, respectively.

Strontium: has increased since 2009 from 0.665 mg/L to a historic maximum of 2.41 mg/L in September 2016.

For all other POIs and other indicator parameters, 2016 values were similar to historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.9 GW96-7 (Southeast Sediment Pond Well)

GW96-7 is located downslope of the Mill Site, half way down the light vehicle tailings access (near the booster pump station). Notable observations in POI results were:

Hardness: Hardness was stable at approximately 145 mg/L through 2010, then spiked to 267 mg/L in May 2011, but has since decreased and was 190 mg/L in May 2016.

Sulphate: Sulphate was stable at approximately 27 mg/L through 2010, then spiked to 158 mg/L in May 2011, but has since decreased to 37.9 mg/L in May 2016.

Nitrate: Nitrate was stable from 2010 to 2014 at 0.0025 mg/L, then spiked to 0.0142mg/L in October 2015 and has since dropped to less than 0.005 mg/L in May 2016.


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Cadmium: Cadmium was stable from 2011 to 2014 between 0.00005 to 0.000012 mg/L then decreased to less than the MDL of 0.000005 mg/L in May 2016, respectively.

Molybdenum: Molybdenum was stable at approximately 0.005 mg/L through 2010, then increased to 0.01 mg/L in May 2011, but has since decreased to 0.00514 mg/L in May 2016.

For the remaining POIs, 2016 values were similar to historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.10 GW00-1a (TSF Northwest Well – Deep)

GW00-1a is located across the Gavin Lake Road, beside the TSF South Embankment. Notable observations in POI and other indicator parameters results were:

Hardness: From the historic maximum of 53.6 mg/L in 2000, levels decreased through 2005 to a historic minimum of 29 mg/L, but have since increased to 49.4 mg/L May 2016.

Sulphate: From the historic maximum of 335 mg/L in 2000, levels decreased through 2005 to a historic minimum of 187 mg/L, but have since increased to 271 mg/L in May 2016.

Molybdenum: From the historic maximum of 0.0271 mg/L in 2000, levels decreased through 2004 to a historic minimum of 0.0165 mg/L in 2004, but have since increased. Concentration was 0.0222 mg/L in May 2016.

For the remaining POIs and other indicator parameters, 2016 values were similar to or below historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.11 GW00-1b (TSF Northwest Well – Shallow)

GW00-1b is located across the Gavin Lake Road, beside the TSF South Embankment. Notable observations in POI and other indicator parameter results were:

Hardness: Levels were stable at approximately 260 mg/L through 2007, but increased between 2007 and 2014, and fluctuated around 540 mg/L. In 2015, hardness increased to 609 mg/L. It slightly decreased to 598 mg/L and 555 mg/L in April and September 2016, respectively.

Nitrate: Has decreased from the spike of 17.1 mg/L in October 2011 to 1.11 mg/L in September 2016, but still remains above baseline levels of below MDL (0.005 mg/L).

Sulphate: Levels were stable at approximately 8 mg/L through 2007, but increased in 2008 and 2009, and


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have since fluctuated in a range of 200 mg/L – 350 mg/L. Concentrations in 2016 samples were 191 mg/L and 169 mg/L in April and September, respectively.

Cadmium: In 2007, levels spiked from approximately 0.00003 mg/L to a historic maximum of 0.000186 mg/L in 2008. Concentrations have since fluctuated between 0.000064 mg/L and 0.000162 mg/L.

Molybdenum: Levels increased from 0.004 mg/L in 2007 to a historic maximum of 0.041 mg/L in May 2013, but have since decreased to 0.0178 mg/L and 0.0201 mg/L in April and September of 2016, respectively.

Selenium: Increased from below MDL in 2000 through 2008 to a historic maximum of 0.029 mg/L in October 2011, but has subsequently decreased to 0.00205 mg/L and 0.00101 mg/L in April and September 2016, respectively.

EC: Golder (Appendix E) mentioned that EC had a slight to moderate increase, however in September 2016 it decreased to 926 µS/cm from 1100 µS/cm. in April 2016

Calcium: Since 2007, calcium has increased to a historic maximum of 137 mg/L in October 2015, and has since dropped to 130 mg/L and 119 mg/L in April and September 2016, respectively.

Magnesium: Slightly increased from 65.4 mg/L in October 2015 to 66.4 mg/L in April 2016 and then decreased to 62.8 mg/L in September 2016, respectively.

Sodium: Golder (Appendix E) mentioned that sodium had a slight to moderate increase, however, it has fluctuated between 22 – 28 mg/L since 2007, and measured 26.2 mg/L and 25.4 mg/L in April and September 2016 samples

Strontium: Golder (Appendix E) reported that strontium had a slight to moderate increase, it was 1.85 mg/L and 1.86 mg/L in April and September 2016.

For the remaining POIs and other indicator parameters, 2016 values were similar to or below historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.12 GW00-2a (TSF West Well – Deep)

GW00-2a is located downstream of the TSF South Embankment. For all POIs and other indicator parameters, 2016 values were similar to historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.13 GW00-3a (TSF Southwest Well – Deep)


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GW00-3a is located downstream of the TSF South Embankment. Notable observations in POI and other indicator parameter results were:

Hardness: There was a slight increase of hardness in May 2016 to 169 mg/L, which is still below the historical maximum of 288 mg/L in 2000.

For all POIs and other indicator parameters, 2016 values were similar to or below historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.14 GW00-3b (TSF Southwest Well – Shallow)

GW00-3b is located downstream of the TSF South Embankment. For all POIs and other indicator parameters, 2016 values were similar to historic results, and any fluctuations or spikes in previous years have stabilized.

5.3.4.15 GW05-01 (Wight Pit/Polley Lake Interface Well)

GW05-01 is located between the Wight Pit, upstream of Polley Lake. It was established in 2005 to capture groundwater moving from Polley Lake towards the Wight Pit and continuously pump it back to Polley Lake. In June of 2010, pumping was terminated making it impossible to sample; however, this well now provides domestic water for the underground operations, and sampling from the tap commenced in June 2012. Notable observations in POI results were:

Sulphate: Levels have fluctuated since 2005 decreasing to a historic minimum of 39.1 mg/L in October 2007 and increasing to a historic maximum of 162 mg/L in May 2008. Sulphate levels decreased through 2010, and have since gradually increased to 160 mg/L in November 2016.

Copper: Levels fluctuated around 0.001 mg/L until 2012 when an increase to the historic maximum of 0.0272 mg/L was observed in November. In 2016 results were an average of 0.0046 mg/L.

Molybdenum: Fluctuated around 0.005 mg/L until 2009 when it began increasing, reaching a historic maximum of 0.00864 mg/L in May 2016.

For all remaining POIs, 2016 values were similar to historic results and any fluctuations or spikes in previous years have stabilized.

5.3.4.16 GW11-1a (Below Temporary NW PAG Stockpile - Deep)

GW11-1a is located below the Temporary NW PAG Stockpile on Bootjack Road to monitor potential impacts on Bootjack Lake. Notable observations in POI results were:


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Hardness: Levels ranged from 73.2 mg/L to 83.0 mg/L in 2011 and 2012. Since 2012, concentrations have increased to 141 mg/L and 127 mg/L in May and September 2016, respectively.

Sulphate: Fluctuated between 17-18 mg/L from 2012 to 2015 and increased to 21.1 mg/L and 20.4 mg/L in May and September 2016, respectively.

Nitrate: Levels increased from below MDL (0.005 mg/L) in 2011 through 2015 to 0.135 mg/L and 0.142 mg/L in May and September 2016, respectively.

Copper: Levels increased from below detection limit in 2011 through 2015 (0.0005 mg/L) to 0.00132 mg/L in October 2015. Copper has since decreased to 0.00081 mg/L and 0.00084 mg/L in May and September 2016, respectively.

Selenium: Levels have increased from MDL (0.0005 mg/L) to 0.000681 mg/L and 0.000931 mg/L in May and September 2016, respectively.


5.3.4.17 GW11-1b (Below Temporary NW PAG Stockpile - Shallow)

GW11-1b is located below the Temporary NW PAG Stockpile on Bootjack Road to monitor potential impacts on Bootjack Lake. Notable observations in POI results were:

Nitrate: Was below MDL (0.005 mg/L) for all sample results until October 2013 when levels increased to 0.0076 mg/L. Concentrations peaked at 0.197 mg/L in May 2014, and have decreased to 0.0065 mg/L and 0.03 mg/L in May and September 2016, respectively.


5.3.4.18 GW11-2a (Below SERDS on Polley Lake Road - Deep)

GW11-2a is located below the SERDS on the Polley Lake Road. Notable observations in POI and other indicator parameter results were:

Aluminum: Has increased from 0.0227 mg/L in December 2011. Since this sampling event, results are stable in the 0.6 to 1.2 mg/L range, with seasonal fluctuations observed. Results in 2016 were 1.15 mg/L and 0.893 mg/L in May and September, respectively.


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Copper: Has increased from 0.00131 mg/L in December 2011, with seasonal fluctuations observed. A historic maximum was recorded in June 2014 at 0.00542 mg/L. Results in 2016 were 0.00262 mg/L and 0.00232 mg/L in May and September, respectively.

For all remaining POIs, 2016 results were in the range of, or below, results from samples taken since 2011, with no increasing trends observed. It is also of note that typically the in situ pH is greater than 12, and the in situ conductivity is approximately 3000 µS/cm. This is likely because the well is located in a calcium deposit; dissolved calcium levels range from 45 to 300 mg/L.

5.3.4.19 GW11-2b (Below SERDS on Polley Lake Road - Shallow)

GW11-2b is located below the SERDS on Polley Lake Road. Notable observations in POI and other parameter results were:

Sulphate: Levels have decreased from 38.7 mg/L in December 2011 and have been less than 3 mg/L since 2013.

Aluminum: Levels were elevated above the 2011 and 2012 concentrations of approximately 0.005 mg/L from 2013 to 2014. Results were 0.0047 mg/L and 0.0038 mg/L in May and September 2016, respectively.

Molybdenum: Levels have continued to decrease from 0.0066 mg/L in December 2011, and were 0.000892 mg/L and 0.000874 mg/L in May and September 2016, respectively.

For all remaining POIs and other indicator parameters, 2016 results were in the range of, or below, results from samples taken since 2011, with no increasing trends observed. Copper results were below MDL (0.0005 mg/L).

5.3.4.20 GW12-1a (NW of Temporary PAG NW Stockpile – Deep)

GW12-1a is located below the northwestern most portion of the Temporary NW PAG Stockpile. Notable observations in POI results were:

Hardness: Levels have dropped from 166 mg/L in June 2013 to 109 mg/L in September 2016.

Sulphate: Levels have increased from 178 mg/L in June 2013 to 212 mg/L and 206 mg/L in May and September 2016, respectively.

Aluminum: Levels have returned to 2013 concentrations of 0.008 mg/L to 0.0086 mg/L in May 2016 and to less then 2013 concentrations in September 2016 (0.0068 mg/L), after a maximum of 0.0108 mg/L was reached in October 2014.


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Arsenic: Levels have increased from 0.00204 mg/L in June 2013 to 0.00418 mg/L and 0.00408 mg/L in May and September 2016, respectively.

Hardness, cadmium, copper, molybdenum, and selenium levels have all decreased since sampling started in May 2013. In 2016, nitrate, cadmium, and copper levels were below MDL (0.005, 0.000005, and 0.0005 mg/L, respectively).

5.3.4.21 GW12-1b (NW of Temporary NW PAG Stockpile – Shallow)

GW12-1b is located below the northwestern most portion of the Temporary NW PAG Stockpile. Notable observations in POI results were:

Sulphate: levels have increased from 14.6 mg/L in June 2015 to 25.8 mg/L and 41.5 mg/L in May and September 2016, respectively.

Nitrate: Increased from a minimum of 0.0482 mg/L in October 2013 to 0.207 mg/L and 0.213 mg/L in May and September 2016, respectively.

Aluminum: Historically below MDL (0.003 mg/L), a spike in October 2014 was recorded at 0.0041 mg/L. Levels have returned to below MDL in 2016.

Arsenic: Increased from June 2013 (0.00149 mg/L) through May 2014 (0.00199 mg/L), but decreased to 0.00164 mg/L and 0.00166 mg/L in May and September 2016, respectively.

Copper: Levels have increased from 0.00161 mg/L in October 2013 to 0.0235 mg/L in September 2016.

For all remaining POIs, 2016 results were in the range of, or below, results from samples taken since 2013, with no increasing trends observed.

5.3.4.22 GW 12-2a (Springer Pit Well – Deep)

GW12-2a is located between the Springer Pit and Bootjack Lake, and was installed to replace the decommissioned well 95R-4. Since July 2015, the monitoring frequency of GW12-2a increased to monthly to monitor seepage conditions from Springer Pit. Notable observations in POI results were:

Sulphate: There has been a slight increase in sulphate since July 2015, with a maximum value of 65.8 mg/L reached in April and December 2016.

Aluminum: A slight decrease in aluminum was observed starting in July 2015, from 0.0085 mg/L to 0.0048 mg/L in December 2016.


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Arsenic: Arsenic levels have remained fairly consistent since 2013, ranging from 0.00199 mg/L in May 2014 to 0.00238 mg/L in December 2016.

Copper: Copper was recorded at 0.00066 mg/L in September 2015. Copper levels have been below MDL (0.0005 mg/L) in all other sampling events.

Molybdenum: Molybdenum levels have remained fairly consistent since 2013, ranging from 0.037 mg/L in to 0.0407 mg/L.

Nitrate, cadmium, and selenium levels have all decreased and are below MDL (0.005, 0.000005, and 0.00005 mg/L, respectively) since sampling started in May 2013.

5.3.4.23 GW 12-2b (Springer Pit Well – Shallow)

GW12-2b is located between the Springer Pit and Bootjack Lake, and was installed to replace the decommissioned well 95R-4. Since July 2015, the monitoring frequency of GW12-2b increased to monthly to monitor seepage conditions from Springer Pit. Notable observations in POI results were:

Hardness: Hardness started increasing in July 2015 from 243 mg/L to a maximum value of 343 mg/L in July 2016.

Nitrate: Nitrate levels have increased from 1.88 mg/L in October 2014 to 4.86 mg/L in December 2015 and has since decreased to 2.75 mg/L in December 2016.

Sulphate: Levels started to increase in July 2015 from 63.3 mg/L to a maximum value of 174 mg/L in August 2016.

Copper: Copper levels have increased since September 2015 from below MDL (000.5 mg/L) to a peak in October 2015 of 0.00177 mg/L. In 2016, levels ranged from 0.0007 mg/L to 0.00084 mg/L.

Selenium: All previous levels before July 2015 were below 0.005 mg/L Selenium has increased to 0.0161 mg/L in December 2015 and levels have since decreased to 0.00632 mg/L in December 2016.

Aluminum, arsenic, cadmium, and molybdenum levels were similar to levels recorded in 2013 and 2014.

5.3.4.24 GW12-3a (Below Waste Haul Road – Deep)

GW12-3a is located below the Waste Haul Road (WHR) and was installed to replace GW96-8a, which was lost due to construction of the Ore Switchback Road, and to monitor potential impacts of the WHR on Mine Drainage Creek and Bootjack Lake. Notable observations in POI results were:


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Nitrate: Nitrate levels in 2014 increased above 2013 levels of less than 0.3 mg/L to 12.6 mg/L in May 2014. In 2016, the levels decreased to 7.99 mg/L and 8.17 mg/L in April and September, respectively.

Cadmium: In May 2014, a maximum level was recorded at 0.000071 mg/L. In 2016, the levels decreased to 0.0000352 mg/L and 0.0000475 mg/L in April and September, respectively.

Copper: Increased from below MDL (0.0005 mg/L) in 2013 to 0.00182 mg/L and 0.00221 mg/L in April and September 2016, respectively.

Selenium: Increased above 2013 levels of less than 0.0065 mg/L to 0.0732 mg/L and 0.0853 mg/L in April and September 2016, respectively.

Hardness, sulphate, aluminum, arsenic, and molybdenum have all decreased since sampling started in May 2013.

5.3.4.25 GW12-3b (Below Waste Haul Road – Shallow)

GW12-3b is located below the WHR and was installed to replace GW96-8a, which was lost due to construction of the Ore Switchback Road, and to monitor potential impacts of the WHR on Mine Drainage Creek and Bootjack Lake. Notable observations in POI results were:

Nitrate: Increased from 0.0727 mg/L in June 2013 to 0.661 mg/L in May 2014, and then decreased to 0.23 mg/L in September 2016.

Arsenic: Levels have increased from 0.0066 mg/L in June 2013 to 0.00881 mg/L in September 2016.

Cadmium: Below MDL (0.000005 mg/L) in all sampling events except for in May 2014; however, the 0.000015 mg/L result is within the range of achieved MDLs.

Molybdenum: All sample results in 2013 to 2015 were approximately 0.03 mg/L. In 2016, levels dropped to 0.0238 mg/L in April and then increased to 0.0345 mg/L in September.

Selenium: Selenium increased from 0.00089 mg/L in June 2013 to 0.0028 mg/L May 2014. In 2016, levels decreased to 0.00129 mg/L and 0.00105 mg/L in April and September 2016, respectively.

Hardness and sulphate levels have decreased since October 2013. Aluminum and copper levels have been below MDL (0.003 and 0.0005 mg/L, respectively) in all sampling events.

5.3.4.26 GW12-4a (Below NEZ Dump – Deep)


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GW12-4a is located below the NEZ Dump, above the Long Ditch, and was installed to improve monitoring of groundwater inflow into Polley Lake. Notable observations in POI results were:

Hardness: levels have dropped from 195 mg/L in October 2013 to 135 mg/L in September 2016.

Molybdenum: After decreasing from 0.00441 mg/L in June 2013 to 0.0406 mg/L in October 2013, levels increased to 0.0582 mg/L and 0.0638 mg/L in May and September 2016, respectively.

All remaining 2016 POIs results were below, or in the range of 2013 levels.

5.3.4.27 GW12-4b (Below NEZ Dump – Shallow)

GW12-4b is located below the NEZ Dump, above the Long Ditch, and was installed to improve monitoring of groundwater inflow into Polley Lake. Notable observations in POI results were:

Hardness: Increased from 151 mg/L in June 2013 to 166 mg/L in October 2015. It increased further to 168 mg/L in May and then dropped to 153 mg/L in September 2016.

Nitrate: Increased from below MDL (0.005 mg/L) in June 2013 to 0.0788 mg/L in September 2016.

Molybdenum: Increased from 0.0365 mg/L in June 2013 to 0.0401 mg/L in May 2014, and then decreased to 0.0375 mg/L in October 2015. It has since fluctuated from 0.0364 mg/L in May to 0.0358 mg/L in September 2016.

Sulphate, arsenic, and cadmium levels have decreased since October 2013. Aluminum and copper levels have been below MDL (0.003 and 0.0005 mg/L, respectively) in all sampling events.

5.3.4.28 GW12-5a (Below Wight Pit Haul Road – Deep)

GW12-5a is located below the Wight Pit Haul Road, and was installed to improve monitoring of groundwater inflow into Polley Lake. Notable observations in POI results were:

Arsenic: Increased from 0.00072 mg/L in June 2013 to 0.0019 mg/L in May 2014, and then decreased to 0.00113 mg/L in September 2016.

Hardness, sulphate, aluminum, cadmium, molybdenum, and selenium levels in 2016 were within the range of or below 2014 results. Nitrate and copper concentrations have been below MDL (0.005 and 0.0005 mg/L, respectively) in all sampling events.

5.3.4.29 GW12-5b (Below Wight Pit Haul Road – Shallow)


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GW12-5b is located below the Wight Pit Haul Road, and was installed to improve monitoring of groundwater inflow into Polley Lake. It was only sampled once in the fall of 2016 due to it being damaged in the spring. Notable observations in POI results were:

Hardness: Levels dropped from 402 mg/L in June 2013 to 296 mg/L in November 2016.

Nitrate: Nitrate levels decreased in 2016 from 0.543 mg/L in 2013 to 0.231 mg/L November.

Sulphate: Levels have decreased from a maximum of 194 mg/L in 2013 to 99.4 mg/L in November 2016.

Copper: Increased from 0.0008 mg/L in June 2013 to 0.0026 mg/L in October 2015. It has since dropped to 0.00172 mg/L in November 2016.

Arsenic, cadmium, molybdenum, and selenium levels were within the range of or below 2014 results. Aluminum concentrations have been below MDL (0.003mg/L) in all sampling events.

5.3.4.30 GW14-01 (Upstream of the TSF at the New Orica Site)

This well provides domestic water to the new Orica Site upstream of the TSF, and replaces GW96-5a/b, which was decommissioned. Notable observations in POI results were:

Nitrate: Levels have increased from below MDL (0.005 mg/L) to 0.033 mg/L and 0.016 mg/L in August and November 2015, respectively. In 2016, levels have decreased to below MDL.

Molybdenum: Molybdenum levels have decreased from 0.00117 mg/L in October 2014 to 0.000244 mg/L in November 2016.

Aluminum, cadmium, and copper concentrations were below MDL (0.003, 0.000005, and 0.0005 mg/L, respectively) for all sampling events. Sulphate, arsenic, and selenium levels were within the range or below 2014 results.

5.3.4.31 GW15-1a (Springer Pit Well North – Deep)

This well is located between the Springer Pit and Bootjack Lake and was installed to monitor seepage from the Springer Pit. It was drilled in June 2015 and has been sampled monthly since July 2015. Notable observations in POI results were:

Hardness: Hardness increased from 24.8 mg/L in July 2015 to a range of 85 – 95 mg/L in the later part of 2015. In 2016, levels fluctuated between 70.5 mg/L to 84 mg/L.


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Aluminum: Aluminum levels decreased from 0.0062 mg/L in July 2015 to 0.0035 mg/L in December 2015. In 2016, levels increased to 0.0082 mg/L in August and then decreased to below MDL (0.003 mg/L) in December 2016.

Arsenic: Levels had a decreasing trend throughout 2016 from 0.00511 mg/L in January to 0.00408 mg/L in December.

Selenium: Selenium levels have decreased from 0.000997 mg/L in July 2015 to below MDL (0.00005 mg/L) in December 2016.

Nitrate and copper levels were all below MDL (0.005 and 0.0005 mg/L, respectively) in 2016. All other POI concentrations were comparable throughout 2016.

5.3.4.32 GW15-1b (Springer Pit Well North – Shallow)

This well is located between the Springer Pit and Bootjack Lake at the beginning of the West Ditch and was installed to monitor seepage from the Springer Pit. It was drilled in June 2015 and has been sampled monthly since July 2015. Notable observations in POI results were:

Hardness: Levels increased from 231 mg/L in July 2015 to a peak of 447 mg/L in July 2016. Levels have since decreased to 274 mg/L in December 2016.

Sulphate: Levels spiked from 127 mg/L in January 2016 to 341 mg/L in July 2016 and then dropped to 172 in December 2016.

Nitrate: Levels increased from 0.259 mg/L in April 2016 to 2.36 mg/L in July 2016 and then decreased again to 1.36 mg/L in December 2016.

Aluminum: Levels have been below MDL (0.003 mg/L) other then a spike of 0.0079 mg/L in February 2016.

Selenium: Levels have decreased from 0.0176 mg/L in January 2016 to 0.0037 mg/L in December 2016.

All other POI concentrations were comparable throughout 2016.

5.3.4.33 GW15-2a (Springer Pit Well South – Deep)

This well is located between the Springer Pit and Bootjack Lake further along the West Ditch than GW15-1a/b. It was installed to monitor seepage from the Springer Pit. It was drilled in June 2015 and has been sampled monthly since July 2015.Notable observations in POI results were:


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Hardness: Levels have decreased from 71.8 mg/L in July 2015 to 52.4 mg/L in December 2016.

Sulphate: Levels have decreased from 48.9 mg/L in July 2015 to 35.7 mg/L in August 2016.

Aluminum: Levels have been below MDL (0.003 mg/L) since November 2015 except for a slight increase in June 2016 to 0.0035 mg/L.

Cadmium, copper, and nitrate levels were all below MDL (0.000005, 0.0005, and 0.005 mg/L, respectively) in 2016. Arsenic, molybdenum, and selenium levels were all comparable to 2015 results.

5.3.4.34 GW15-2b (Springer Pit Well South – Shallow)

This well is located between the Springer Pit and Bootjack Lake further along the West Ditch than GW15-1a/b. It was installed to monitor seepage from the Springer Pit. It was drilled in June 2015 and has been sampled monthly since July 2015. Notable observations in POI results were:

Hardness: Levels increased from 134 mg/L in July 2015 to 160 mg/L in June 2016. It dropped again to 125 mg/L in December 2016.

Sulphate: Increased from 68.1 mg/L in September 2015 to 84.9 mg/L in June 2016 and then dropped to 75 mg/L in December 2016.

Nitrate: Levels increased from 0.0225 mg/L in July 2015 to 1.0 mg/L in May 2016. Levels decreased to 0.301 mg/L in December 2016.

Aluminum, cadmium and copper levels were all below MDL (0.003, 0.000005, and 0.0005 mg/L, respectively). All other POI concentrations were comparable with 2015 results.

5.4 Climate

MPMC’s Permit 11678, section 3.6 (Appendix A) requires the collection of detailed meteorology data. The objective of this data collection program is to provide site-specific precipitation and evaporation data for use in water balance calculations and hydrological predictions. Mount Polley maintains two (2) automated HOBO weather stations. These stations monitor temperature, rainfall, solar radiation, relative humidity, wind direction, wind speed, and wind gust speed. Weather Station #1 is located approximately 1 km southeast of Polley Mountain and was installed in September 2012. Weather Station #2 is located northeast of the TSF (between the Rock Quarry and Biosolids Storage Facility) and was installed in November 2012. Due to equipment and battery issues, only partial data is available from Station #1 for October, September, November, and December. There were no periods in 2016 when both stations were not logging data. A summary of the monthly site precipitation, evaporation, and temperature data


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collected in 2016 is provided in Table 5.3.

Evaporation is calculated The automated using the Penman-Monteith equation using the WaSIM software developed by Cranfield University. Snowfall measurements are based on monthly snowpack testing done at multiple locations across the site. These measurements are taken at the end of every month, as well as between melting and snowfall events, if forecasted.

Table 5.3 Mount Polley 2016 monthly precipitation, evaporation, and temperature data

Month Monthly

Precipitation as Rain (mm)

Monthly Snowpack (mm Snow Water

Equivalent)

Evaporation (mm)

Average Temperature

(°C)

Maximum Temperature

(°C)

Minimum Temperature

(°C)

January 31.5 167 8 -4.6 7.4 -20.6 February 26.4 219 18 -0.4 8.5 -8.6 March 17.2 50 45 2.2 17.5 -6.8 April 33.9 0 96 8.2 23.3 -1.0 May 51.0 0 125 10.0 26.8 -0.5 June 66.2 0 133 13.0 27.9 2.0 July 76.3 0 113 14.8 27.8 5.4 August 19.5 0 125 16.1 28.4 4.5 September 91.4 0 55 8.6 22.9 -0.3 October 93.2 0 17 4.1 13.5 -4.6 November 24.3 29 15 2.6 16.4 -6.2 December 0.0 86 3 -11.1 0.1 -24.8

5.4.1 Wind Monitoring

It has been confirmed by the database company (EHS Data) that previous wind data presented here before the 2015 annual report was an inaccurate representation of site conditions. The figures presented below are an accurate representation of the 2012 to 2016 data. Figure 5.1 shows wind data collected by the site weather stations in 2016, and data collected on site since fall 2012. Data collected in 2016 are consistent with data collected in the past three years. High speed winds are typically observed from the northwest, but in general there is no dominant wind direction.


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Figure 5.1 Mount Polley wind data for 2016 (left), and for fall 2012 to the end of 2016 (right)

5.4.2 Temperature

In 2016, the lowest monthly mean temperature was -11.1 °C recorded in December, and the highest monthly mean temperature was 16.1 °C recorded in August. Temperatures were warmer than average in all months except July, September, and December when compared to site data collected since 1995. Figure 5.2 presents a comparison of 2016 maximum, mean, and minimum monthly temperatures with average monthly temperature data (based on data collected at Mount Polley since 1995). This data is shown in tabular form in Table 5.3.


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Figure 5.2 Maximum, mean and minimum monthly temperature data for Mount Polley (2016 versus average)

5.4.3 Precipitation

In 2016, 810 millimetres (mm) of precipitation were recorded: 531 mm as rain and 279 mm as snow water equivalent (SWE). This is above the average annual precipitation of 630 mm, with both rainfall and snowfall above their respective annual averages. The 2016 snowpack peaked in February, and was above average (129% of average). Total rainfall varied compared to monthly averages, with the most rain falling in October (93 mm) and September (91 mm). The driest non-freezing month was August, with 19.5 mm of rain recorded. Precipitation data by month are presented in Table 5.3, Figure 5.3, and Figure 5.4. All precipitation averages are calculated based on data collected at the Mount Polley Mine site since 1995.

-30.0

-20.0

-10.0

0.0

10.0

20.0

30.0

40.0

Tem

pera

ture

(°C)

Monthly Temperatures (°C)

Average Mean Temp 2016 Mean Temp Average Max Temp

2016 Max Temp Average Min Temp 2016 Min Temp


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Figure 5.3 Monthly rainfall at Mount Polley (2016 versus average)

Figure 5.4 Monthly snowpack at Mount Polley (2016 versus average)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Rain

fall

(mm

)Precipitation as Rainfall (mm)

Average 2016

0

50

100

150

200

250

January February March April November December

Snow

Wat

er E

quiv

alen

t (m

m)

Snowpack (mm)

Average 2016


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5.4.4 Evaporation

Total open water evaporation in 2016 was calculated to be 753 mm. June experienced the greatest amount of evaporation at 133 mm. Monthly evaporation data are presented in Table 5.3. Figure 5.5 presents monthly comparisons of precipitation and evaporation for 2016.

Figure 5.5 Mount Polley 2016 monthly precipitation and evaporation

0

20

40

60

80

100

120

140

Prec

ipita

tion/

Evap

orat

ion

(mm

)

2016 Precipitation & Evaporation

Precipitation (Snow + Rain) Evaporation


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6 Discharge System and Monitoring

The WTP is a Veolia ACTIFLO® system, which was commissioned in October 2015. Discharge began on December 1, 2015, and continued throughout 2016. The total discharge in 2016 was 6,709,918 m3. The 2016 Annual Discharge Plan (MPMC, 2016c) was prepared and submitted to the MoE on June 16, 2016; it was approved on December 20, 2016.

6.1 Discharge System

Prior to May 4, 2016, the discharge system directed mine contact water to the Perimeter Embankment Till Borrow Pit (PETBP), primarily by pumping water from the Springer Pit to the West Ditch (which had been armoured in 2015 to reduce erosion). The West Ditch gravity fed to the CCS (via the SERDS Ditch), and the CCS gravity fed to the PETBP. In April 2016, a direct pipeline from the Springer Pit to the WTP (bypassing the PETBP) was constructed. It was commissioned on May 4, 2016, feeding the WTP with water solely sourced from the Springer Pit. This direct line allows the WTP to be run in passive mode (i.e., no addition of reagents or mechanical mixing in the WTP) when the Springer Pit is providing sufficient treatment (Golder 2016a).

During treatment, the feed water of the WTP undergoes suspended solids removal using Veolia ACTIFLO® water treatment technology prior to discharge to upper Hazeltine Creek and conveyance in the reconstructed, non-fish bearing creek channel. The WTP doses the raw water with coagulant to a tank where a polymer is injected to create floc particles. Microsand is added to ballast the flocculants, which move on to another tank that allows them to swell and mature. The water flows to the next stage, which uses lamella to clarify the water and promote fast settling of the microsand ballasted sludge. The clarified water is discharged and the sludge is separated from the microsand, which is reused. An on-line turbidity meter measures the turbidity every ten seconds and calculates the TSS using a calibrated factor based on a site-specific correlation between turbidity and TSS. If the on-line TSS is above 13 mg/L for 10 minutes, or over 14 mg/L instantaneously, an alarm sounds to alert the operator and the WTP automatically goes into recirculation mode and ceases discharge.

In lower Hazeltine Creek, the water is transferred into Quesnel Lake from the Hazeltine Creek upper sedimentation pond via intake structures which feed two pipelines with diffusers (two sedimentation ponds were constructed in lower Hazeltine Creek following the 2014 TSF embankment breach to reduce suspended solids loadings into Quesnel Lake). The water discharge will have flow rates of up to 0.3 m3/s, be continuous (year-round), and be operational for a maximum of two years, during which time the long-term strategy is planned to be implemented, as described in Section 3.1.5.

6.1.1 Outfall and Pipeline Inspection

According to Section 3.5 of Permit 11678 (Appendix A), routine visual inspection of the outfall into Quesnel Lake, along with the pipeline, must be conducted. Routine visual inspections are conducted daily


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and records are maintained. A comprehensive inspection and testing of the outfall must be conducted by a QP annually for the first three years (2015-2017), followed by once every three years thereafter (starting with 2020). The comprehensive inspection conducted on September 7, 2016 and was submitted to MoE. There were no follow up requirements identified.

6.2 Discharge Monitoring

This discharge triggered the Metal Mine Effluent Regulations (MMER) and reporting to Environment Canada continued in 2016 as outlined in the MMER. Section 3 describes the field sampling equipment and methodology. Table 6.1 outlines the number of sampling events at each site in 2016.

Table 6.1 Sampling events in 2016 at discharge monitoring sites

Site Name Site Identifier (EMS No.) Full Sample Suite Frequency Actual Sampling Events

E11 E302090 Weekly/Monthly (a) 17

E11a E305894 Weekly (b) 38

E19 E305050 Weekly (c) 61

HAD-03 E304230 Weekly (c) 61

HAC-05a E304510 Monthly 13

HAC-08 E303013 Monthly 13

HAC-10 E303010 Monthly 18

HAC-12 E304351 Weekly (c) 55

HAC-13 E304810 Weekly (c) 57

QUL-57 E304874 Weekly/Monthly (d) 2

QUL-58 E304876 Weekly/Monthly (e) 19

QUL-59 E304875 Weekly/Monthly (d) 3

QUL-2a E303020 Monthly (f) 9

QUL-18 E303019 Monthly (f) 9

QUL-120a E303022 Monthly/Seasonally (g) 5

QUR-1 E303026 Bi-monthly (h) 8

QUR-11 E306454 Bi-monthly/Monthly (i) 11 (a) Weekly until replaced by E11a

(b) Established April 28, 2016; replaced E11

(c) When discharging

(d) Weekly sampling between spring and fall turnover, twice in winter until March 28, 2016; reduced to monthly profiles only based on the recommendations provided in Golder’s Review of Monitoring Frequency in Quesnel Lake (Appendix I)

(e) Weekly during spring and fall turnover; monthly all other times of the year (2016 CEMP included weekly


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sampling at QUL-58. This was reduced based on the recommendations provided in Golder’s Review of Monitoring Frequency in Quesnel Lake (Appendix I)

(f) Monthly between spring and fall turnover

(g) Monthly between spring and fall turnover until August 24, 2016; seasonally (four times per year) afterwards

(h) Bi-monthly until replaced by QUR-11

(i) Established April 6, 2016; replaced QUR-1; reduced to monthly June 1, 2016

6.2.1 Plume Dispersion Model

Tetra Tech EBA Inc. (Tetra Tech EBA) was retained by MPMC to assess the long-term and far-field fate of effluent discharge from the diffusers in Quesnel Lake (see Section 6.1). Tetra Tech EBA applied the existing hydrodynamic model of Quesnel Lake to simulate effluent concentrations throughout the lake as a result of the discharge. After the simulations were completed, MPMC requested advice with respect to the likely position of the effluent plume by month, to support monitoring in the field (Tetra Tech EBA 2016).

6.3 Discharge Water Quality Results

Discharge water quality results were reviewed by Golder and are presented in Appendix H.

6.4 Discharge Toxicity Testing Results

A summary of the toxicity tests completed in 2016 is shown in Table 6.2.

Table 6.2 Toxicity sampling events in 2016 at discharge monitoring sites

Site Name

Site Identifier (EMS No.) Test Type Frequency Actual Sampling

Events

HAD-03 E304230

96-h rainbow trout LC50 Monthly 12 48-h D. magna LC50 Monthly 12 7-d C. dubia survival and reproduction Quarterly 4 7-d rainbow trout embryo-alevin Quarterly (a) 4 (b) 72-h P. subcapitata growth inhibition Bi-annually 2 7-d L. minor growth inhibition Bi-annually 2

HAC-12 E304351 7-d rainbow trout embryo-alevin Quarterly (a) 4 (b) 7-d C. dubia survival and reproduction Quarterly 4

(a) If test media not available at testing laboratory, 7-d rainbow trout swim-up survival and growth test was substituted

(b) Test media unavailable in first quarter; substituted with 7-d rainbow trout swim-up survival and growth test

Results of the toxicity tests are provided in Appendix H.


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7 Hazeltine Creek Aquatic Environment Monitoring

7.1 Surface Water Monitoring

According to the Short Term Water Discharge Monitoring Plan (STWDMP), all Hazeltine Creek sampling and monitoring locations are considered discharge sites and are found in Section 6. Supplemental monitoring sites were established and a geochemical conception model for the upper Hazeltine Creek and Polly Flats area was prepared by SRK Consulting (SRK) and Minnow Environmental (Minnow) for MPMC (SRK and Minnow 2016).

7.2 Groundwater

In 2016, an updated groundwater program was implemented around the Hazeltine Creek area as part of the on-going ERA for MPMC. The final report will be submitted early 2017. Locations of the new wells are located in Appendix E.

7.3 Hydrology

In 2016, hydrological monitoring in Hazeltine Creek was completed at sites H1 (Upper Hazeltine Creek) and H2 (Lower Hazeltine Creek), as required by section 3.4 of Permit 11678 and section 5.3.2 of the CEMP (Appendix A). Manual flow measurements were taken from January through December, when flow rates were sufficient. Due to the remediation efforts around the upper Hazeltine Creek area, flow was controlled by the Polley Lake weir and not indicative of the natural flow regime. Flow regime was also impacted by the discharge from the WTP, with incremental flow contributions not exceeding 0.3 m3/s.

An additional hydrolometric station was installed in Hazeltine Creek after completion of the Upper Hazeltine Reclamation Project. This station, designated as site H4, is located approximately 150 meters downstream from the Polley Lake Weir.

Pressure transducers at H1 and H2 were left in-place during the winter of 2015/2016. They were removed from H1, H2 and H4 in late November and December 2016.

Tables and figures presenting the 2016 hydrology results at all sites, including hydrographs, stage discharge rating curves, pressure-stage relations, goodness of fit statistics and photographs are presented in Appendix J.

7.3.1 Site H1 - Upper Hazeltine Creek

Thirty (30) staff gauge readings and twenty-five (25) manual flow measurements were taken between January 14 and November 9, 2016. The highest manually measured discharge rate was 0.49 m3/s on August 11, 2016.


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Pressure transducer data from a PT2x were recorded from April 14 to July 25, 2016. Due to technical difficulties with the PT2x, it was removed and sent to the manufacturer for repair and the data were not retrievable. Solinst leveloggers and barologgers recorded pressure from January 1 through December 13, 2016. A benchmark survey conducted on August 24 indicated the hydrology station did not need adjustment; however WaterSmith raised the stilling well be raised by 0.077m on August 25th to minimize sediment accumulation around the logger. A corresponding vertical offset was applied to all automated water level data recorded in 2016 prior to the adjustment.

A stage-discharge rating curve was developed to relate the staff gauge readings and the manual discharge measurements made in 2016, and a stage-pressure relation was developed between the manual staff gauge readings and the automated pressure data to allow application of the rating curve to the automated pressure data. Due to ice build-up at the station during winter months, staff gauge and automated water level measurements recorded prior to March 31, 2016, were omitted during development of the stage-pressure relation and the rating curve. An assessment of the goodness of fit of the manual readings (after March 30th) to the stage-discharge rating curve yielded a mean difference of 4.6% and a standard error of 3.2%. The stage-discharge rating curve is provided in Appendix J.

Continuous records of stage and discharge values for the monitoring season were generated from the compensated levelogger data. Discharge was consistently elevated during freshet in April. Flow declined in May and plateaued during the rest of the year, with sporadic peaks in July and October due to heavy precipitation events augmented by discharge from the water treatment plant and managed outflows from Polley Lake. The highest estimated discharge rate was 0.71 m3/s on October 27, 2016.

7.3.2 Site H2 - Lower Hazeltine Creek

Forty-three (43) staff gauge readings and thirty-two (32) manual flow measurements were taken between January 6 and November 23, 2016. The highest manually measured discharge rate was 0.98 m3/s on April 6, 2016. The stage-discharge rating curve based on 2016 data is included on the graph in Appendix J.

A Solinst barologger and levelogger recorded pressure from January 1 through December 21, 2016. A PT2x logger recorded water pressure from April 12 to December 21 as a backup and to confirm data reliability. A benchmark survey conducted on August 24 indicated the hydrology station did not need adjustment; however, WaterSmith raised the stilling well by 0.092m on August 25th to minimize sediment accumulation around the loggers. A corresponding vertical offset was applied to all automated water level data recorded in 2016 prior to the adjustment.

A stage-discharge rating curve and a stage-pressure relation were developed as outlined in Section 7.3.1 for H1, including omission of water level measurements recorded prior to March 31 due to ice effects. Additional measurements were also excluded due to technical errors. The goodness of fit assessment yielded a mean difference of 4.5% and a standard error of 2.7 (%).


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Continuous records of stage and discharge for the monitoring season were generated from the pressure transducer data. Discharge was consistently elevated during freshet in April. Flow declined in May and plateaued during the rest of the year, with sporadic peaks in July and September due to heavy precipitation events augmented by discharge from the WTP and managed outflows from Polley Lake. The highest estimated discharge rate was 1.48 m3/s on September 17, 2016.

7.3.3 Site H4 - Polley Lake Weir

Installation of a stilling well, staff gauge and weir was completed in October 2016. Three (3) staff gauge readings and flow measurements were taken between October 28 and November 22, 2016. The highest measured discharge rate was 0.45 m3/s on November 22, 2016. As only three flows were measured, a reliable rating curve could not be developed.


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8 Aquatic Receiving Environment

8.1 Surface Water Quality

Surface water monitoring and analysis was conducted as outlined in the CEMP (Appendix A). Refer to Section 4.2 for a discussion of field sampling equipment and methodology. Sampling stations and frequency are summarized in Table 8.1 and locations are shown in the CEMP (Appendix A)

Table 8.1 Sampling events in 2016 at surface water quality sites


Frequency

Permit Requirement Actual

W1b E225084 Monthly 12

W4a E298551 Monthly 12 Weekly (a) 7

W5 E208039 Monthly 12 Weekly (a) 7

W8 E216743 Quarterly 5 Weekly (a) 8

W8z E223292 Quarterly 4 W10 E291209 Monthly 12

EDC-01 E303014 Monthly 12

Weekly (b) 9 W12 E216744 Quarterly 4 W20 E297070 Quarterly 3 (c)

(a) Weekly TSS and turbidity sampling for five (5) weeks during spring freshet and autumn low flows (b) Weekly TSS and turbidity at EDC-01 was only taken during the first freshet after channel reconstruction (c) Dry August 16, 2016

Samples were submitted to ALS for analysis of:

• Physical parameters (pH, turbidity, TSS, total dissolved solids, and hardness); • Anions and nutrients (alkalinity, chloride, fluoride, sulphate, total nitrogen, nitrate, nitrite,

ammonia, phosphorus total and dissolved, and ortho-phosphorus); • Organics (dissolved organic carbon); and • Total and dissolved metals (metals suite as listed in CEMP Appendix A).

Results of the surface sites were compared with the BC MoE Water Quality Guidelines (BCWQG) for Aquatic Life. In 2016, there were forty-nine (49) exceedances of the acute BCWQG for aquatic life at the permitted surface water monitoring sites (Table 8.2). Note that the list of analytes with concentrations greater than BCWQG is similar to baseline. Exceedances for the chronic BCWQG for dissolved aluminum,


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total copper, and total selenium were present at various sites, however, since only monthly or quarterly sampling is required for these sites as per the CEMP (Appendix A), the required five samples taken in thirty days to calculate the average was not met. Therefore, these comparisons are for screening purposes only (Meays 2012) and are not listed in Table 8.2; they are described in the individual site sections below. Additional details for each site is provided in the following sections and Appendix D. Appendix D includes tables of all results for the past five years and graphs of the parameters measured. It was noted at time of publishing that the 95th percentile presented on the graphs may be incorrect. MPMC will ensure that is corrected for future reports. Note that results below method detection limit (MDL) are represented as half (0.5x) the MDL in statistical calculations and graphs.

Table 8.2 Summary of acute BCWQG exceedances for aquatic life at surface water monitoring sites

Site Parameter Results Acute BCWQG (mg/L) W1 Dissolved aluminum 0.174 mg/L; 0.164 mg/L 0.1

Total copper 5 exceedances - see Section 8.1.1 for details 0.0055-0.0172(a) W4a Total copper 0.042 mg/L 0.0105 (a) W5 Dissolved aluminum 7 exceedances - see Section 8.1.3 for details 0.1

Total copper 9 exceedances - see Section 8.1.3 for details 0.0043-0.008 (a) Total zinc 5 exceedances - see Section 8.1.3 for details 0.033

W8 Dissolved aluminum 0.228 mg/L; 0.231 mg/L 0.1 W8z Dissolved aluminum 4 exceedances - see Section 8.1.5 for details 0.1

Total copper 0.00617 mg/L; 0.00555 mg/L 0.0046-0.0051 (a) Dissolved iron 0.568 mg/L 0.35

W10 Dissolved aluminum 4 exceedances - see 8.1.6 for details 0.1 EDC-01 Dissolved aluminum 0.166 mg/L; 0.155 mg/L 0.1

Total copper 0.00853 mg/L 0.0062 (a) Total iron 1.11 mg/L 1

W20 Dissolved aluminum 3 exceedances - see Section 8.1.9 for details 0.1

(a) Hardness dependent copper guideline; range given is based on hardness range at each site, when available.

8.1.1 Site W1 – Morehead Creek (E225084)

This site was sampled twelve (12) times in 2016. Graphs for a subset of parameters are provided in Appendix D. There were seven (7) acute BCWQG exceedances at this location in 2016. Notable observations in the results were:

Hardness: An increase in hardness was first observed in 2015 and hardness remained elevated in 2016. In 2016 the maximum was 163 mg/L compared 142 mg/L in 2015, and the 2016 annual mean was 65 mg/L compared to 74 mg/L in 2015.

Sulphate: A general increase in sulphate levels has been recorded at W1 since 2005. In 2016 levels were


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lower than in 2015 with a maximum of 12.1 mg/L (61 mg/L in 2015) and an annual mean of 6.80 mg/L (17.86 mg/L in 2015).

Chloride: An increase in chloride has been observed at this site since 2009. The maximum concentration recorded in 2016 was 73.9 mg/L (4.78 mg/L in 2015 and 11.4 mg/L in 2014) and the mean was 8.11 mg/L (2.22 mg/L in 2015 and 4.71 mg/L in 2014). The maximum value was recorded in September and appears to be an outlier however there was a duplicate sample collected at the same time that returned similar results.

TSS: A general increase in TSS was observed in 2016 compared to 2015, possibly due to increase runoff during heavy rainfall periods throughout the year. The maximum concentration observed in 2016 was 13.6 mg/L in May, which is above chronic BCWQG (see description in Section 8.1). The annual mean was 5.35 mg/L.

Dissolved Aluminum: There were two (2) acute exceedances for dissolved aluminum in 2016. Results from April and November yielded elevated concentrations of 0.174 mg/L and 0.164 mg/L respectively. The annual mean was 0.058 mg/L. There were four (4) chronic exceedances (see description in Section 8.1); the maximum observed was 0.1740 mg/L in April.

Total Copper: There were five (5) acute guideline exceedances in the results for total copper in 2016. Three of those results occurred during the freshet period and two results occurred in the fall. The maximum concentration recorded above the BCWQG in 2016 was 0.0243 mg/L in September; an elevated result also occurred at the same period in 2014, but not in 2015. The annual mean was 0.0079 mg/L. There were twelve (12) chronic exceedances (see description in Section 8.1).

Total Chromium: A maximum of 0.00098 mg/L was observed in November.

There were no noted trends in any other parameters in 2016.

8.1.2 Site W4a – North Dump Creek below Wight Pit Road (E298551)

This site replaced site W4 on July 7, 2014. W4a was sampled twelve (12) times in 2016 for full metals suites and seven (7) times for turbidity and TSS only. Graphs for a subset of parameters are provided in Appendix D. There was one (1) acute BCWQG exceedance at this location in 2016.

Dissolved Aluminum: Elevated dissolved aluminum levels were observed in March and April 2016, but were below acute BCWQG. The annual mean was 0.0252 mg/L. There were two (2) chronic exceedances (see description in Section 8.1); the maximum observed was 0.0923 mg/L in March.

TSS: A maximum value of 9.5 mg/L was observed in April and an annual mean of 2.1 mg/L. Seven (7)


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samples were below MDL.

Total Copper: There was one (1) acute exceedance for copper in 2016. The maximum value was observed at 0.042 mg/L in April. All other results are similar to the 2015 levels (with exception to November when 2016 was lower than 2015). The annual mean was 0.0098 mg/L. There were four (4) chronic exceedances in February, March, May and November (see description in Section 8.1).

Total Chromium: A maximum of 0.0012 mg/L was observed in April, which is above the chronic BCWQG (see description in Section 8.1). The annual mean was 0.0004. mg/L.

Total Selenium: A maximum of 0.0026 mg/L was observed in April, which is above the chronic BCWQG (see description in Section 8.1). The annual mean was 0.0013 mg/L.

There were no noted trends in any other parameters in 2016.

8.1.3 Site W5 – Bootjack Creek (E208039)

This site was sampled twelve (12) times for full metals suite and seven (7) times for TSS and turbidity only. Due to the TSF breach in August 2014, Bootjack Creek no longer flows directly to Hazeltine Creek resulting in a disconnection in fish habitat. In October 2014, fish were salvaged and are excluded from Bootjack Creek. Graphs of all POIs for this location are included in Appendix D. There were twenty-one (21) acute BCWQG exceedances at this location. Notable observations in POI results were:

Hardness: A maximum hardness of 142 mg/L was observed in January; elevated levels above 100 mg/L were also observed in August and September. The annual mean is 64.68 mg/L.

Sulphate: A maximum concentration of sulphate was observed at 72.6 mg/L in January. All other results were below 15 mg/L and the annual mean was 10.6 mg/L.

Dissolved Aluminum: There were seven (7) acute BCWQG exceedances at this location in 2016. The maximum value above the acute BCWQG was 0.283 mg/L in February. From February to July, with the exception of June, all dissolved aluminum results exceeded the guidelines. Two (2) more exceedances occurred in November and December. All the exceedances were within the range of historical levels. The annual mean was 0.15 mg/L. There were nine (9) chronic exceedances (see description in Section 8.1).

Total Copper: There were nine (9) acute exceedances at this location in 2016. The maximum value above the BCWQG was 0.018 mg/L in July. The exceedances occurred between February and July, and again between October and December; however, these exceedances were within the range of historical levels. The annual mean was 0.011 mg/L. There were two (2) chronic BCWQG exceedances, April, June, and August (see description in Section 8.1).


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Total Chromium: A maximum of 0.0012 mg/L was observed in February and March, which is above the chronic BCWQG, and additional exceedances were observed in July and November (see description in Section 8.1). The annual mean was 0.0009 mg/L.

Total Zinc: There were five (5) acute BCWQG exceedances of total zinc in April, June, August, October, and December. The maximum value above the BCWQG was 0.0472 mg/L. The annual mean was 0.0271 mg/L.

There were no noted changes in any other parameters at this location in 2016.

8.1.4 Site W8 – Northeast Edney Creek Tributary (E216743)

This site was sampled five (5) times in 2016 for full metals suite and eight (8) times for turbidity and TSS only. Graphs for a subset of parameters are provided in Appendix D. There were two (2) acute BCWQG exceedances at this location in 2016. Notable observations in POI results were:

Dissolved Aluminum: There were two (2) acute exceedances at this location in. The maximum value above the acute BCWQG was 0.231 mg/L in October. The other exceedance occurred in April. The annual mean was 0.13 mg/L. There were two (2) BCWQG chronic exceedances in February and May (see description in Section 8.1).

Total Copper: A maximum of 0.0087 mg/L was observed in November, which is above the chronic BCWQG (see description in Section 8.1). Another chronic exceedance occurred in April. The annual mean was 0.0044 mg/L.

Total Chromium: A maximum of 0.0013 mg/L was observed in May, which is above the chronic BCWQG (see description in Section 8.1). The annual mean was 0.0009 mg/L.


8.1.5 Site W8z – Southwest Edney Creek Tributary (E223292)

This site was sampled four (4) times in 2016. It should be noted that this is a control site, as it is not downstream of any Mount Polley Mine components. Graphs for a subset of parameters are provided in Appendix D. There were seven (7) acute BCWQG exceedances at this location in 2016.

Dissolved Aluminum: There were four (4) acute BCWQG exceedances at this location. The maximum value above the acute BCWQG was 0.406 mg/L in February, which is the range of historical levels. The annual mean was 0.29 mg/L. There were four (4) chronic BCWQG exceedances in (see description in Section 8.1).


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Total Copper: There were two (2) acute BCWQG exceedances at this location. The maximum value above the BCWQG was 0.00617 mg/L in February, which is within the range of historical levels. The annual mean was 0.0049 mg/L. There were two (2) chronic BCWQG exceedances in August and November (see description in Section 8.1);

Dissolved Iron: There was one (1) acute exceedance at this location. The maximum value above the BCWQG was 0.568 mg/L in February. The annual mean was 0.333 mg/L.

Total Chromium: A maximum of 0.0018 mg/L was observed in February, which is above the chronic BCWQG (see description in Section 8.1). Chronic guidelines were exceeded three additional times (May, August, and November). The annual mean was 0.0015 mg/L.

Total iron was markedly higher in February than in previous years.

8.1.6 Site W10 – Edney Creek (E291209)

Prior to this becoming a permitted site there were only a few samples collected here since 1995. This site was sampled twelve (12) times in 2016 for full metals suite. This site is a reference site, selected for comparisons to the sites downstream from the mine disturbance, including a site in the re-engineered channel of Edney Creek. Graphs for a subset of parameters are provided in Appendix D. There were four (4) acute BCWQG exceedances at this location in 2016.

Dissolved Aluminum: There were four (4) acute BCWQG exceedances at this site. The maximum value above the acute BCWQG was 0.202 mg/L in April. This value is above background range and is not consistent with previous results, therefore it is potentially a sampling or analytical error. The other three (3) exceedances occurred in March, November and December. The annual mean was 0.076 mg/L. There were two (2) chronic BCWQG exceedances in February and May (see description in Section 8.1).

Total Copper: A maximum of 0.0043 mg/L was observed in April, which is above the chronic BCWQG (see description in Section 8.1). There were three other exceedances in May, November and December. The annual mean was 0.0027 mg/L.

Total Chromium: A maximum of 0.0015 mg/L was observed in April, which is above the chronic BCWQG (see description in Section 8.1). The annual mean was 0.0008 mg/L.

TSS: A maximum of 13.1 mg/L was observed in April, which is above the chronic BCWQG (see description in Section 8.1). The annual mean was 2.2 mg/L; eight results were below the detection limit.



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8.1.7 Site EDC-01 – Edney Creek below constructed channel (E303014)

Located just upstream of the mouth of the creek near Quesnel Lake, this site was established in February 2015 after the newly constructed Edney Channel was completed and opened to fish passage. This site is used to monitor any potential impacts on Edney Creek from the new construction. EDC-01 was sampled twelve (12) times in 2016 for full metals suite and seven (7) times for TSS and turbidity only. There were four (4) acute exceedances at this site. Considering W10 as the background site for Edney Creek, the following observations are noted:

Dissolved Aluminum: There were two (2) acute BCWQG exceedances at this site. The maximum value above the BCWQG was 0.166 mg/L in April. The other BCWQG exceedance occurred in November. There were five (5) chronic BCWQG exceedances in February, March, May, July, and December. Comparing these results to W10, the levels at EDC-01 were similar.

Total Copper: There was one (1) acute BCWQG exceedance at this site. The maximum value above the BCWQG was 0.00085 mg/L in April. The annual mean was 0.005 mg/L at EDC-01 compared to the mean of 0.0027 mg/L at W10. Chronic BCWQG for total copper was exceeded eight (8) times in February, March, May, June, July, August, November, and December (see description in section 8.1).

Total Iron: There was one (1) acute BCWQG exceedance at this site. The maximum value above the BCWQG was 1.11 mg/L in April. The annual mean was 0.34 mg/L at EDC-01 compared to the mean of 0.28 mg/L at W10.

Total Chromium: A maximum of 0.002 mg/L was observed in April, which is above the chronic BCWQG (see description in Section 8.1). Two other chronic exceedances occurred in November and December. The annual mean was 0.0008 mg/L.

Ammonia: A maximum of 0.0169 mg/L was recorded in July and the mean annual value was 0.008 mg/L. This is compared to 0.0079 mg/L in July and a mean of 0.007 mg/L at W10.

Nitrate: Nitrate was slightly elevated compared to the background site but well below the BCWQG at a mean of 0.1774 mg/L compared to a mean of 0.112 mg/L at W10.

Sulphate: Results were above sulphate levels at W10 for much of the year, but remained below the BCWQG. The maximum observed was 51.7 mg/L (September) and the mean annual value was 16.63 mg/L compared to a maximum of 9.71 mg/L (September) and a mean of 4.36 mg/L at W10.

TSS: Results were similar throughout the year with the exception of the samples collected on April 4, 2016. The result at EDC-01 was 24.9 mg/L while at W10, the TSS was 13.1 mg/L.


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Total Molybdenum: Results were somewhat elevated compared to background, but remained below the BCWQG. The maximum for 2016 at EDC-01 was 0.0057mg/L and the annual mean was 0.002 mg/L, compared to a maximum of 0.002 mg/L and a mean of 0.0007 mg/L at W10.

Total Selenium: Results were elevated above background but remain below the BCWQG. The maximum at EDC-01 was 0.0013 mg/L and the annual mean was 0.00055 mg/L compared to a max of 0.0002 mg/L and a mean of 0.00015 mg/L at W10.

Total arsenic, cadmium, and zinc were all similar to the upstream station of W10.

8.1.8 Site W12 – 6K Creek at Road (E216744)

This site was sampled four (4) times in 2016. Graphs for a subset of parameters are provided in Appendix D. No acute BCWQG exceedances were found in 2016. Notable observations in parameters results were:

Hardness: Hardness results in 2016 were within the range of variability observed in previous years. Ranging between 72.6 mg/L and 114 mg/L.

Sulphate: All results are well below the BCWQG. The annual mean was 15.36 mg/L and the maximum was 26.6 mg/L.

Total Copper: A maximum of 0.0067 mg/L was observed in November, which is above the chronic BCWQG (see description in Section 8.1). Two other chronic exceedances occurred in February and May. The annual mean was 0.0057 mg/L.

There were no other changes in parameters observed at this location in 2016 compared to past years.

8.1.9 Site W20 – W20 Creek (E297070)

This site was sampled three (3) times in 2016; no flow was observed during the August 16, 2016 sampling event. Graphs for a subset of parameters are provided in Appendix D. There were no notable changes in parameters observed at this location in 2016 compared to past years. There were three (3) acute BCWQG exceedances at this location in 2016.

Dissolved Aluminum: There were three (3) BCWQG acute exceedances during the sampling events at this site. The maximum value above the BCWQG was 0.172 mg/L in November, which falls within the historical range. There were three (3) chronic BCWQG exceedances (see description in Section 8.1); the maximum observed was 0.172 mg/L in November.

Total Copper: A maximum of 0.007 mg/L was observed in November, which is above the chronic BCWQG


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(see description in Section 8.1). There were two other chronic exceedances in 2016.The annual mean was 0.0059 mg/L.

8.2 Lake Sampling

In 2016, lake sampling was completed as outlined in the CEMP in Appendix A (see Table 8.3). Refer to Section 3 for a discussion of field sampling equipment and methodology.

Appendix K includes tables of all results for the past five years and graphs of the parameters measure. It was noted at time of publishing that the 95th percentile presented on the graphs may be incorrect. MPMC will ensure that is corrected for future reports. Note that results below method detection limit (MDL) are represented as half (0.5x) the MDL in statistical calculations and graphs.

Table 8.3 Lake water quality sampling locations in 2016

Site Site

Identifier (EMS No.)

Profile Frequency Sample Frequency Permit

Requirement Actual Permit Requirement Actual

P1 E207974 Bi-monthly 14

Monthly 8 P2 E207975 Bi-monthly 14

Monthly 8

B1 E207972 Bi-monthly 11

Bi-annually 2 B2 E215897 Bi-monthly 11

Bi-annually 2

QUL-ZOO-1 E306455 Bi-annually 2

Bi-annually 2 QUL-ZOO-7 E306456

Bi-annually 2

Bi-annually 2

QUL-ZOO-8 E306457 Bi-annually 2

Bi-annually 2 QUL-42 E299023 Supplemental 4 Supplemental 4

8.2.1 Bootjack Lake

In Bootjack Lake, station B1 is located at the northwest end of the lake and station B2 is located at the southeast end. These selected stations were not at the deepest locations for the 2016 monitoring season and these sites will be relocated to the deepest areas for future sampling. Sampling occurred during spring turnover in April and in late summer in August and limnological profiles were taken bi-monthly (with the exception of May when only one profile was collected) at stations B1 and B2 as per section 8.1.2.2 in CEMP (Appendix A). Profile and chemistry data are presented in Appendix K.

Four locations (B3, B4, B5, and B6) were created near areas of potential exfiltration from the Springer Pit supernatant. Additional profiles were taken at these sites when the Springer Pit supernatant elevation exceeded 1030 masl in 2016 as per the recommendations from Golder (2016a). One water quality sample was also collected for background purposes.


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8.2.1.1 In Situ Data

In 2016, MPMC recorded profile data at B1 and B2 eleven (11) times. Profiles of pH, conductivity, dissolved oxygen, turbidity, and temperature as well as secchi depth were measured at B1 and B2 on Bootjack Lake twice a month from April to October 2016. During the lake turnover event in spring 2016 as well as throughout the year, field parameters were consistent with previous years. The temperature profiles indicate that the lake was stratified at the time of sampling.

Profiles were taken at locations B3, B4, B5, and B6 intermittently between April and October. No noticeable increases of any parameter were identified at the additional sites. Investigations were conducted using specific conductivity to locate areas of possible exfiltration from the Springer Pit supernatant at various depths.

8.2.1.2 Lake Water Chemistry

Water samples for analytical chemistry were collected at surface and bottom when the lake is isothermal and at surface, bottom, and every 5 m when the lake is not isothermal at sites B1 and B2. Appendix K contains water chemistry data tables with results from the last five years. There have been no significant changes in water chemistry in Bootjack Lake.

One sample was taken at site B3 in April 2016. There was an increase at depth of turbidity and it is likely that the lake bottom was disturbed during the sampling event.

8.2.2 Polley Lake

In Polley Lake, station P1 is located at the deepest point at the north end of Polley Lake and station P2 is located at the deepest point at the south end of Polley Lake and are shown in Appendix A. Sampling occurred monthly during and in between spring and fall overturn and limnological profiles occurred bi-monthly along with the secchi depth during the same period as per section 8.1.2.3 in the CEMP (Appendix A). No sampling events occurred in winter 2016 due to unsafe ice conditions. Profile and chemistry data are presented in Appendix K.

8.2.2.1 In Situ Data

In 2016, MPMC recorded profile data at P1 and P2 fourteen (14) times. Profiles of pH, specific conductivity, dissolved oxygen, turbidity and temperature were measured at P1 and P2 twice a month from April to November 2016. During the lake turnover event in spring 2016 as well as throughout the year, field parameters were consistent with previous years.

Water samples for analytical chemistry were collected at surface, bottom, and every 5 m in between when conditions were not isothermal and every 10 m when isothermal at sites P1 and P2. Further discussion is


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included in the PEEIAR (MPMC, 2016a) and HHERA (Golder, 2015e) reports.

8.2.3 Quesnel Lake

In Quesnel Lake, site QUL-ZOO-1 is located in the centre of the West Basin, QUL-ZOO-7 is located in front of Horsefly Bay, and QUL-ZOO-8 is located at the junction of the North, East and West Arms (found in the CEMP in Appendix A). Sampling and limnological profiles occurred bi-annually as per section 8.5.2 in the CEMP (Appendix A). For monitoring information for all other Quesnel Lake sites see section 6.3 and Appendix K.

MPMC continues to collect profile and surface water quality data from these sites to be used in the analysis of plankton results (see section 8.6).

8.2.3.1 Supplemental Site

In 2016, a supplemental site, QUL-42, was established in Quesnel Lake to monitor water quality in Mitchell Bay. This site was sampled on January 20, April 27, May 19, and October 26, 2016. The water quality data from this site was provided to Christine McLean (member of the Concerned Citizens of Quesnel Lake) on November 16, 2016.

8.3 Hydrology

In 2016, hydrological monitoring was completed at sites W1b (Morehead Creek), W4a (North Dump Creek), W5 (Bootjack Creek), W12 (6km Creek), and H3 (Edney Creek) as required by section 3.4 of the Permit 11678 and section 6.2 of the CEMP (Appendix A). Supplemental monitoring was carried out at W8 (Northeast Edney Creek Tributary), the Long Ditch, the SERDS, the NW Ditch, Junction Zone Ditch, Joe’s Creek Pipe, the Cut-off Wall Drain, and the Main and South Toe Drains at the TSF. Refer to Appendix A for a map of monitoring locations.

Pressure transducers were installed at W1b, W5, W12, SERDS, and the Long Ditch during non-freezing months and removed during freezing months. The pressure transducer at H3 was not removed during the winter of 2015-2016.

Tables and figures presenting 2016 hydrology results at all sites, including hydrographs, rating curves, pressure transducer figures, and statistical analysis are presented in Appendix J.

8.3.1 Site W1b – Upper Morehead Creek

Ten (10) staff gauge readings and manual flow measurements were taken between April 7 and September 16, 2016. The highest manually measured discharge rate was 0.35 m3/s on April 14, 2016 by WaterSmith Inc using the salt dilution method. The stage-discharge rating curve based on 2016 data is included in


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Appendix J.

Pressure transducer data were recorded from April 14 to November 16, 2016. WaterSmith made significant changes to the site on April 14, including removal of debris and installation of a new stilling well and staff gauge. A stage-pressure relation and a stage-discharge rating curve were developed using the monitoring results after April 14. Some measurements were excluded from the rating curve due to technical errors. An assessment of the goodness of fit of the manual readings to the stage-discharge rating curve yielded a mean difference of 4.1% and a standard error of 3.5%.

Continuous records of stage and discharge values for the monitoring season were generated from the pressure transducer data. Discharge peaked in April and followed a downward trend after the freshet period, reaching the lowest flow in September. The highest estimated discharge rate was 0.36 m3/s on April 14, 2016.

8.3.2 Site W4a – North Dump Creek

At site W4a, seventeen (17) bucket flow measurements were recorded from a constructed pipe weir between March 1 and December 1, 2016. No staff gauge or pressure transducer was installed at this site in 2016. The highest estimated discharge rate was 0.0082 m3/s on April 25, 2016.

8.3.3 Site W5 – Bootjack Creek above Hazeltine Creek

Twenty-two (22) staff gauge readings and six (6) manual flow measurements were taken between April 5 and December 1, 2016. No measurements were taken in the late summer due to negligible flow. The highest manually measured discharge rate was 0.027 m3/s on October 8, 2016. The stage-discharge rating curve based on 2016 data is provided in Appendix J.

Pressure transducer data were recorded from April 13 to November 28, 2016. A new stilling well and staff gauge were installed on April 13, 2016, approximately ten (10) meters downstream of the previous station. A stage-pressure relation and a stage-discharge rating curve were developed using the monitoring results after April 13, 2016. An assessment of the goodness of fit of the manual readings to the stage-discharge rating curve yielded a mean difference of 4.6% and a standard error of 4.2%.

Continuous records of stage and discharge values for the monitoring season were generated from the pressure transducer data. High flows were recorded in April, then receded after the freshet period to mid-June. Discharge increased sporadically in late September through the fall, which had numerous days of heavy rainfall. The highest estimated discharge rate was 0.066 m3/s on October 30, 2016.

8.3.4 Site W12 – 6 km Creek at Bootjack Road

Fifteen (15) staff gauge readings and fourteen (14) flow measurements were taken between April 6 and


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October 27, 2016. The highest manually measured discharge rate was 0.47 m3/s on April 6, 2016. The stage-discharge rating curve equation based on 2016 data is included on the graph in Appendix J.

Pressure transducer data from the PT2x were recorded from April 12 to November 29, 2016. A new stilling well was installed by WaterSmith on April 14, 2016. A stage-pressure relation and a stage-discharge rating curve were developed using the monitoring results after April 14. An assessment of the goodness of fit of the manual readings to the stage-discharge rating curve yielded a mean difference of 7.9% and a standard error of 5.8%.

Continuous records of stage and discharge values for the monitoring season were generated from the pressure transducer data. Discharge peaks occurred in April, July, September and throughout October and November. The highest estimated discharge was 0.22 m3/s on July 16, 2016. This elevated flow was potentially influenced by the high precipitation events in June and early July. Also note that the PT2x was installed after peak freshet and that the highest manually measured flow was approximately two and half times higher than the highest automated flow record.

8.3.5 Site H3 – Lower Edney Creek

Sixteen (16) staff gauge readings and eleven (11) manual flow measurements were taken between January 27 and November 23, 2016. The highest manually measured discharge rate was 3.14 m3/s on April 12, 2016 by WaterSmith using the salt tracer method. The stage-discharge rating curve based on 2016 data is included in Appendix J.

No PT2x was installed at this location. A Solinst levelogger recorded data from January 1 to December 5, 2016. A benchmark survey conducted on August 24 indicated the hydrology station did not need adjustment. A stage-pressure relation and a stage-discharge rating curve were developed using the 2016 monitoring results. An assessment of the goodness of fit of the manual readings to the stage-discharge rating curve yielded a mean difference of 10.6% and a standard error of 8.9%.

Continuous records of stage and discharge values for the monitoring season were generated from compensated levelogger data using the barologger from H2. Flow peaked during freshet in April and decreased at the beginning of May. The highest estimated discharge rate was 5.0 m3/s on April 6, 2016.

8.3.6 Supplemental Sites

Flow monitoring and/or staff gauge measurements were also done at supplemental sites including W8 (Northeast Edney Creek Tributary), the Long Ditch, the SERDS, the NW Ditch, Junction Zone Ditch, Joe’s Creek Pipe, the Cut-off Wall Drain and the Main and South Toe Drains at the TSF. Results are presented in Appendix J. These flow measurements from site water management system components are primarily used for verifying the site water balance.


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8.4 Sediment Quality

Results from some monitoring conducted in 2016 will be presented in documents associated with the HHRA and ERA, which are both due in 2017.

8.5 Benthic Invertebrates


8.6 Plankton, Chlorophyll a, and Secchi Disk

8.6.1 Plankton and Chlorophyll a

Phytoplankton community and chlorophyll a samples were taken two times per growing season. In 2016, two (2) phytoplankton and three (3) chlorophyll a samples were taken in July and August at the following stations (map in Appendix A):

• P1 (Polley Lake deepest area at the north end);

• P2 (Polley Lake deepest area at the south end);

• QUL-58 (Quesnel Lake near-field; at discharge IDZ);

• QUL-18 (Quesnel Lake far-field downstream);

• QUL-2a (Quesnel Lake far-field upstream);

• QUL-120a (Quesnel Lake upstream reference).

Zooplankton samples were also collected twice per growing season (July and August) at the same stations in Polley Lake (P1 and P2), but at different stations in Quesnel Lake; Quesnel Lake monitoring is conducted at three stations historically sampled by DFO, so pre- and post-TSF embankment breach results can be compared for both spatial and temporal trends. Station 1 (QUL-ZOO-1) is located in the centre of the West Basin, station 7 (QUL-ZOO-7) is located in front of Horsefly Bay, and station 8 (QUL-ZOO-8) is located at the junction of the North, East, and West Arms.

Results from past and upcoming monitoring will be presented in documents associated with the ERA, which is due in 2017.

Field methodology is described in Section 4.2

8.6.2 Secchi Disk

During each sampling and profiling event, a secchi depth measurement (Table 8.4) was collected as per section 6.5 of the CEMP (Appendix A). Secchi depth data are included in Appendix K. Note that it is


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unlikely that station relocation on Bootjack Lake would not effect secchi data.

Table 8.4 Secchi depth measurement events in 2016.


Secchi Depth Measurement Events

P1 E207974 14 P2 E207975 13

B1 E207972 12

B2 E215897 11

All secchi depths measured were within the range of measurements from previous years.

8.7 Fish



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9 Terrestrial Monitoring

Terrestrial Environmental Monitoring was implemented as per section 9 of the CEMP (Appendix A). Wildlife observations and notes were recorded throughout the year as per section 9.1 of the CEMP (Appendix A). Soil, soil invertebrates and vegetation monitoring were ongoing in 2016 and the results will be presented in the HHRA and ERA in 2017.

9.1 Wildlife Monitoring

The Mount Polley site and surrounding area is home to a wide variety of wildlife including ungulates, carnivores, raptors, water fowl, song birds, mustelids, amphibians and a host of aquatic organisms. With extensive wildlife activity on the mine site, MPMC provides training to all employees regarding management of food waste and bear awareness. This training and information is intended to help keep MPMC employees and the wildlife safe.

To meet requests by the MoE and various stakeholders, to provide valuable data for evaluating the effects of the mine on wildlife, and to monitor wildlife habitat creation through reclamation, the MPMC Environmental Department records wildlife observations and incidents on the mine site. In addition, other departments on site track observations and submit them to the Environmental Department to document. This information is considered valuable for future reclamation and land use planning.

In 2016, there were 533 recorded wildlife observations, including , sightings, scat, and tracks, reported at MPMC (refer to Table 9.1). The observations included a wide range of different birds, carnivores, and several insects. It is assumed that t number of reported observations is only a fraction of the actual observations, but suggests regular use of the site by wildlife. Note the frog/toad and long-toed salamander observations are not added to the total – they are considered as one event during the amphibian salvage. Table 9.1 indicates some generic observations such as “Bird”, “Eagle”, and “Deer”, these entries refer to sightings with no positive species identification. There were no wildlife incidents reported in 2016. Table 9.1 2016 wildlife observations at Mount Polley Mine

Wildlife Observed On Site Surrounding Area

Number Of Observations

Tracks/Scat Observations

Number of Observations


American Dipper 7 4 American Kestrel 3 Barn Owl 1 Bald Eagle 17 4 Bear 13 1 Bigfoot 1


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Bird 1 Black Bear 129 2 24 Blue Heron 3 1 Bobcat 3 Butterfly 2 Canada Goose 6 1 Chipmunk 7 Coho Salmon 1 Common Goldeneye 1 Coyote 57 11 7 Crow 1 1 Dark headed Junco 1 Deer 37 5 1 Duck 1 2 Eagle 1 Ermine 2 Fox 2 1 Frog/toad 75000+(a) Garter Snake 3 Geese 1 Golden Eagle 3 Golden Eye Duck 2 Gray Jay 1 Great Horned Owl 1 Grouse 11 1 1 Hawk 5 Heron 1 Hummingbird 1 Killdeer 8 Kokanee 1 1 Long Toed Salamander 300+(a) Loon 6 2 Lynx 25 18 7 Merlin 1 Moose 27 6 3 1


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Mouse 2 Mule deer 18 Muskrat 1 1 Northern Harrier Hawk 1 Osprey 2 Otter 2 Owl 2 1 1 Rabbit 2 Red Fox 1 Red Tailed Hawk 11 Robin 1 Sand piper 1 Sandhill crane 4 Seagull 1 1 Skunk 4 Slug 1 Snow goose 1 Snowshoe Hare 5 2 Sparrow 1 Spider 2 Spotted Tussock Caterpillar 1 Squirrel 3 1 1 Swallow 1 Swan 3 1 Water Beetle 1 Water Fowl 1 Weasel 1 1 Wolf 4 3 1 1 Wolverine 4 1 Woodpecker 3 Wren 1 1

(a) Included as one event in the total observational count

9.2 Soil


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In 2016, ongoing soil sampling was conducted in the Lower Hazeltine area in accordance with the Work Plan for Monitoring in Support of the Risk Assessment at Mount Polley Mine (Golder, 2016b) and as identified by the HHERA Problem Formulation Report (Golder, 2015e) as per section 9.2 of the CEMP (Appendix A). Results from these sampling events will be presented in the HHRA and ERA in 2017.

9.3 Soil Invertebrate

As part of the on-going ERA investigation, soil invertebrates were sampled in the Hazeltine Creek floodplain and halo area in 2016. Results from tissues collected in 2015 and 2016 will be appended in the ERA.

9.4 Vegetation

As part of the on-going HHRA investigation, berries and plants were sampled in the Hazeltine Creek floodplain and halo area in 2016. Results from tissues collected in 2015 and 2016 will be appended in the HHRA.


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10 Annual Report Changes

The format of this annual report has been updated to better align with the organizational format of the CEMP (Appendix A) for easy reference.


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11 Reclamation Program

The objectives of the reclamation program are outlined in Section 1.1.1. To achieve these objectives, as outlined in the most recent PRCP (January 2017) (MPMC 2017a), MPMC has established projects at the site to research soil amendments and application methods, re-vegetation, vegetation metal uptake, and passive water treatment. Based on the results of these research projects, larger scale progressive reclamation has been ongoing at Mount Polley since 2010, with two primary benefits:

1. Conducting reclamation during the operating life of the mine reduces the size of disturbed area requiring reclamation at closure, and minimizes liabilities.

2. Sites undergoing progressive reclamation can be continually monitored, and reclamation prescriptions modified based on findings. Using this approach, it is anticipated that a refined prescription for meeting reclamation objectives will be developed, and can be applied site wide at closure.

An update on 2016 reclamation activities and research projects is included in this section, as well as an updated five-year reclamation plan. 2016 reclamation activities at the Mount Polley Mine site were limited somewhat to allow reclamation resources to be allocated to tailings breach related restoration initiatives in Hazeltine Creek and adjacent to Polley and Quesnel Lakes. Further reclamation information can be found in Mount Polley Mining Corporation Mine Reclamation and Closure Plan Update January 2017.

11.1 Reclamation Cost Update

A detailed reclamation cost update for the end of 2016 has been completed and submitted to the MEM under separate cover.

11.2 Stability of Works

11.2.1 Rock Disposal Sites

Examinations of RDSs are made in accordance with section 6.10.1 of the Health, Safety and Reclamation Code for Mines in British Columbia (HSRC). Monitoring of RDSs occurs according to the terms and conditions of a variance granted by the MEM on February 9, 2001. A report on the 2016 RDS inspection, prepared by a Qualified Professional, was submitted to the MEM on March 20, 2017.

11.2.2 Pit Walls

Pit walls are monitored for stability using high-precision 3-D surveys and surface inspections. Pit wall stability is reviewed annually by a third party Qualified Professional from an engineering services firm. A report on the 2016 pit slope inspection, prepared by a Qualified Professional, was submitted to the MEM


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on March 20, 2017.

11.2.3 Tailings Storage Facility and Associated Works

MPMC has received staged amendments for construction works at the TSF following the completion of construction of the Freshet Management Embankment in 2015. Additionally, construction of the Main Embankment and Perimeter Embankment Buttress for the 970 m stability, authorized by the MEM on October 22, 2015, was still in progress at the end of 2015.

MPMC received the following authorizations under Permit M-200 pertaining to construction of the TSF in 2016:

• February 25, 2016 – placement of Upstream Fill in accordance with the TSF Detailed Design to 970 m

• April 29, 2016 – construction of the Corner 1 Buttress for the 963 m stability in accordance with the TSF Detailed Design to 970 m

• June 23, 2016 – construction of the TSF to the 970 m design in accordance with the TSF Detailed Design to 970 m

Construction of the Main Embankment Buttress and Perimeter Embankment Buttress Extensions to the 970 m stability design was completed in 2016. An As-built Report for the Main Embankment and Perimeter Embankment Buttress was prepared by the Engineer of Record (EoR) and submitted to the MEM on January 31, 2017.

Construction of the TSF Corner 1 raise was completed to a nominal elevation of 959 m in 2016. A letter indicating completion of the placement of Upstream Fill, as required under the February 15, 2016 Permit M-200 amendment, was submitted to the MEM on February 25, 2016. An As-built Report for the 2016 Corner 1 Raise Construction was prepared by the EoR and submitted to the MEM on March 29, 2017. Construction of the Corner 1 Buttress for the 963 m stability was substantially completed in 2016, and is scheduled for completion in 2017.

An annual dam safety inspection, as required under the HSRC was completed by the EoR in 2016 and submitted to the MEM on January 16, 2017.

Additionally, a TSF geotechnical investigation program was completed in 2016/2017 under the supervision of the EoR. A factual report on the geotechnical site investigation, as required under the June 23, 2016 Permit M-200 amendment, was submitted to the MEM on January 16, 2017.


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11.3 2016 Reclamation Activities

11.3.1 Reclamation Inspection

On June 6, 2016, MEM conducted a site visit to review changes in site conditions since the last inspection and to carry out a Mines Act environmental and reclamation compliance inspection. An inspection report was issued including recommendations related to Permit M-200 the Health, Safety and Reclamation Code for Mines in BC, and established best practices in environmental management and mine reclamation. The inspection report also included a review of the 2015 Annual Environmental and Reclamation Report.

The report did not include any orders, but did include five recommendations, that could be applied for continuous improvement related to reclamation and closure planning. All recommendations have been considered, and a summary is provided in Table 11.1.

Table 11.1 Summary of MEM reclamation inspection recommendations

Recommendation MPMC Response

Improved implementation of site preparation methods in progressive reclamation areas

MPMC is in agreement with this recommendation. Site staff are gaining considerable experience in working with equipment operators to create desirable surface microtopography through the rehabilitation work that is being conducted in the Hazeltine Creek corridor.

Implementation of the detailed site survey planned as part of the Invasive Plant Management Plan Planned for 2017

Review of reclamation predictions to confirm sufficient quantities of required materials (i.e., native seeds and seedlings) will be available at closure

A review was submitted with the 2017 RCP Update (MPMC 2017a). No supply concerns were identified with the current material sources (on-site seed collection, native seed vendors, and commercial nurseries).

Use of fertilizer (or compost tea, if fertilizer use is not preferred) or hydro-seeding to aid in vegetation establishment on soil stockpiles

Annual soil stockpile inspections identify stockpiles where additional revegetation is recommended. MPMC’s Soil Management Plan in MPMC’s RCP Update (MPMC 2017a), has been updated to include options for improved revegetation of these stockpiles.

Establishment of a secondary containment at the fuel storage area

Secondary containment (a stormwater collection system beneath the storage area and runoff catchment ditches) is already in place.

The conclusion of the report stated that “[o]verall the site was tidy and in good order” and that “recommendations from the 2015 inspection have been addressed or are being considered and progressive reclamation activities continue to explore techniques and practices that will inform reclamation strategies.”


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11.3.2 Progressive Reclamation

Progressive reclamation completed to date is detailed in Table 11.2. Further information on progressive reclamation at Mount Polley Mine can be found in MPMC RCP Update January 2017 (MPMC 2017a).

Table 11.2 Progressive reclamation completed at Mount Polley Mine as of December 31, 2016

11.3.2.1 Waste Dumps: North Bell Dump

No new reclamation work was completed on the North Bell Dump in 2016. Monitoring of past reclamation is ongoing.

11.3.2.2 Waste Dumps: NEZ Dump

No new reclamation work was completed on the North East Zone Dump in 2016. Monitoring of past reclamation is ongoing.

11.3.2.3 Waste Dumps: Boundary Dump

The Boundary Dump is one of the few areas of the mine site that was covered with soil that was not stockpiled. Stripped soil the foundation preparation for the PAG Dump was immediately placed on the boundary dump. The intent was to investigate the benefits of direct placed soils from a restoration perspective and specifically the benefit of residual soil seed bank and its effect on biodiversity.

The Boundary Dump was planted with conifers in June 2016. 4910 Lodgepole Pine and 2160 Interior Douglas Fir were planted at an average density of 1644 stems per hectare.

Recommendations are to continue to monitor natural ingress in 2017 (this area is adjacent to undisturbed forest) and use monitoring results to assess the need for future planting of trees and shrubs. A survival survey is also planned for the 2016-planted conifers.

2016 Total 2016 Total 2016 Total 2016 Total 2016 Total2a, 2b1, 2b2 0.00 5.13 0.00 5.13 0.00 5.13 0.00 5.13 0.00 5.13Beside 2a/2b 0.00 2.47 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Parcels 1 - 10 0.00 11.59 0.00 11.59 0.00 11.59 0.00 11.59 0.00 11.59South Triangle 0.00 1.30 0.00 1.30 0.00 1.30 0.00 1.30 0.00 1.30Phase 1 0.00 2.21 0.00 2.21 0.00 2.21 0.00 2.21 0.00 0.00Phase 2 0.00 2.87 0.00 2.87 0.00 2.87 0.00 2.87 0.00 0.00Metro Van Research 1 0.00 2.81 0.00 2.81 0.00 1.87 0.00 2.34 0.00 2.34Wrap Around Toe 0.00 0.00 0.00 2.20 0.00 2.20 0.00 0.00 0.00 0.00Beside Research 1 0.00 4.76 0.00 1.99 0.00 0.00 0.00 0.00 0.00 0.00Metro Van Research 2 0.00 2.00 0.00 2.00 0.00 1.33 0.00 1.66 0.00 2.00Beside Research 2 0.00 2.73 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Boundary Zone Dump 0.00 4.70 0.00 4.70 0.00 0.00 0.00 0.00 4.70 4.70Above Access Road 0.00 9.10 0.00 4.06 0.00 4.06 0.00 0.00 2.75 2.75Highway to Heaven 0.00 9.47 2.89 9.47 2.89 6.58 0.00 0.00 9.47 9.47Tree Plots 0.00 2.31 0.00 2.31 0.00 2.31 0.00 1.20 0.00 2.31Above WHR 0.00 1.81 0.00 1.81 0.00 1.81 0.00 0.00 0.00 0.00Below Helipad 0.00 1.53 0.00 1.53 0.00 1.53 0.00 1.53 0.00 1.53

South Till Borrow 0.00 23.95 0.00 0.00 0.00 14.75 0.00 12.00 0.00 0.00TOTAL 0.00 90.74 2.89 55.98 2.89 59.54 0.00 41.83 16.92 43.12

Re-contoured (ha) Seeded (ha) Fertilizer/Biosolids (ha) Tree-Planted (ha)Soil/Till Applied (ha)Area Parcel

NEZ Dump

NBD

Waste Haul Road

East RDS


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11.3.2.4 Waste Dumps: East RDS

Numerous reclamation activities were completed on the East Rock Dump in 2016. Soil was applied to 3.4 hectares of the dump slope at the Highway to Heaven site to a depth of 0.25 m, as can be seen in Figure 11.1. This area was also grass seeded with MPMC custom Native Mix see table Table 3.3 A small amount of grass seeding was completed on the Above Access Road site to fill in the previous year’s seeding.

Portions of the East Rock Dump were planted with conifers in June 2016. Conifers were planted at the Highway to heaven site and Above the Access Road Site. 14450 Lodgepole Pine and 5610 Interior Douglas Fir were planted on the Highway to Heaven site at an average density of 2233 stems per hectare. 1960 Lodgepole Pine and 1895 Interior Douglas Fir were planted on the Above Access Road site at an average density of 1960 per hectare.

Recommendations are to continue to monitor natural ingress in 2017 and use monitoring results to plan for future planting of trees and shrubs. Trees and shrubs, which create an overstorey, are important for managing invasive species. Selection of trees and shrubs should take into considerations to hot, dry conditions on this south-west facing aspect areas.

Figure 11.1 2016 Soil Placement on the Highway to Heaven Site

11.3.2.5 Watercourse Reclamation


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No watercourse reclamation was conducted in 2016.

11.3.2.6 Pit Reclamation

No pit reclamation was conducted in 2016. The Bell Pit, Pond Zone Pit, and Southeast Zone (SEZ) Pit have been back-filled by waste dumps and will not require reclamation.

11.3.2.7 TSF Reclamation

No reclamation was conducted at the TSF in 2016.

11.3.2.8 Road Reclamation

No road reclamation was conducted in 2016.

11.3.2.9 Treatment of Structures and Equipment

No site structures or equipment were salvaged or disposed of in 2016.

11.3.2.10 Securing of Mine Openings

There was no sealing or securing of any mine entrances in 2016; both portal and escape ways remain open and in use.

11.4 2016 Reclamation Research Update

No reclamation assessments or investigations were conducted in 2016. Information on ongoing and past reclamation research can be found in MPMC Annual Environmental and Reclamation Reports from years 2010 to 2015. Further information can be found in MPMC RCP Update January 2017 (MPMC 2017a).

11.4.1 Native Species Establishment

Native species establishment is a target for all current and future reclamation at Mount Polley Mine. It has been initiated in a variety of ways. Seedlings of native species have been propagated and planted at the site utilizing the services of commercial nurseries. MPMC Native ground cover seed mix consists of native species. Also, site preparation surface roughening techniques such as ripping, mounding and windrowing are utilized in part to assist in seed recruitment from adjacent woodlands.


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11.4.2 Biosolids

In 1999, the MoE issued MPMC a permit to import biosolids from the Greater Vancouver Regional District (now Metro Vancouver) for the purpose of mine site reclamation (Permit 15968). After initial receipt and stockpiling of the biosolids shipments in 2000, the program was suspended due to the temporary closure of the mine; biosolids shipment recommenced in 2007. In 2014 Permit 15968 was amended to include:

• An increase in the maximum rate of land application from 150 dry tonnes (dt)/ha to 165 dt/ha; • An increase in the maximum cumulative discharge from 90,000 dt to 99,000 dt; • Revised references to MPMC land claims and an updated site plan; and • The allowance of two designated storage facilities.

Currently there is only one biosolids stockpile on site, located near the TSF. Table 11.3 provided by Metro Vancouver, summarizes biosolids deliveries and applications at Mount Polley from 2000 to 2014. No biosolids were stockpiled on site in 2016. As no deliveries were made in 2016, no Metro Vancouver biosolids were assessed for compliance with Permit 15968 requirements or compared to the Organic Matter Recycling Regulation criteria for Class A biosolids. Results from a composite sample taken from the biosolids storage facility on November 28, 2016 and analyzed at ALS Environmental laboratory in Burnaby, BC are provided in Table 11.4

Table 11.3 Metro Vancouver biosolids deliveries and applications at Mount Polley (2000 – 2014)


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Table 11.4 Results from biosolids storage facility composite sample taken November 28, 2016

BIOSOLIDS STOCKPILE 28-Nov-2016 12:57

Parameter Lowest Detection Limit Units Soil

Physical Tests (Soil) Moisture 0.25 % 73.9 Leachable Anions & Nutrients (Soil) Total Kjeldahl Nitrogen 0.80 % 3.03 Plant Available Nutrients (Soil) Available Ammonium-N 640 mg/kg 6980 Available Nitrate-N 4.0 mg/kg 8.7 Available Nitrite-N 1.6 mg/kg <1.6 Available Phosphate-P 200 mg/kg 1160 Available Sulfate-S 16 mg/kg 777 Bacteriological Tests (Soil) Coliform Bacteria - Fecal 2 MPN/g <2 Salmonella - Not Isolated

11.4.3 Vegetation Metal Uptake

Mt Polley Inventory, Updated: Oct. 28, 2014

Annacis Lulu Total (wt) Total (dt )

10,754 10,754 25814,641 4,641 1114

7,101 124 7,225 216016,136 42 16,178 43671,206 1,206 3389,664 9,664 2706

3,875 3,875 11635,058 5,058 1416

1,060 1,060 2971,482 1,482 415

2013 Deliveries: Tree Trial Plots (Sept. 28 - Oct. 6) 960 960 269706 706 198

Delivered 2000-to-present 47,247 15,561 62,808 17022

Annacis Lulu Total (wt) Total (dt )tree research plots (circa 2000/01) 234 234 56

NEZ - 2008 3,875 3,875 1,163 North Bell Roadside Slopes (Areas 1 - 10) - 2011 11.6 122 5,058 5,058 1,416

North Bell (Areas 11 - 19) - 2012 5.1 140 2,542 2,542 712 North Bell Tree Trial Plots (Plots 2-6) - 2013 2.3 104 960 960 269

North Bell Tree Trial Plots (Plots 8-12) - 2014 1.7 118 706 706 198 -

13,141 234 13,375 3,813 34,106 15,327 49,433 13,209

Stockpile Location Delivery Date Biosolids Delivered

Tailings Storage Facility Stockpile(Area 1)

2000/01 inventoryFeb 7 - Nov 2, 2007Aug 5 - Nov 1, 2009

Jan 1 - Nov. 12, 2010Apr 4 - 14; July 4, 2011Apr 25 - Sept. 4, 2013

NEZ Sep 28 - Nov 19, 2008Apr 15 - May 29, 2011

Biosolids Utilized

CONFIRMED - APPLIED/USED to date

North Bell

2012 deliveries: MPMC "Area 2" (May 30 - June 17)2012 deliveries: MPMC "Area 1" (June 18 - July 31)

2014 Deliveries : Tree Trial Plots (May 21 - 27)

Carry Over (at TSF)

Applications

Site ID ha rate(dt/ha)


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Reclamation research led by MPMC has included an ongoing series of interrelated studies that address concerns related to the possible presence of trace elements in soils above background concentrations, and routes for the uptake of these elements into vegetation, with the possible risk scenario of the concentrations in vegetation leading to impacts on human health or the environment. The purpose of this monitoring is to evaluate if vegetation growing on reclaimed areas at the Mine site has different levels of metal uptake when compared with baseline and reference site data, and to assess if elevated metal concentrations (if encountered) are of concern for grazing and wildlife species or humans.

This research program has included ongoing vegetation monitoring, as well as monitoring of metal concentrations in natural soils stockpiled for reclamation use, and monitoring of trace element concentrations in soil/biosolid mixtures being evaluated for use in reclamation. Vegetation metal uptake monitoring at the Mine site has included baseline monitoring programs in 1989, 1995, and 1996, complemented by monitoring of reclaimed areas in 2007, 2012, and 2014. In these programs, various vegetation types (grass, legume, and shrub species that may be foraged by cattle and wildlife) were sampled and analyzed for metal content.

More recently, as part of the Hazeltine Creek environmental impact assessment and rehabilitation works, a formal terrestrial ecological risk assessment is being conducted by Golder for metal uptake into vegetation that grows directly in the tailings.

Data from the ongoing monitoring program is being used, as required, in the Human Health and Terrestrial Ecosystem Assessments (HHRA and ERA) for the TSF embankment breach. That risk assessment is currently characterizing an acceptable concentration range for metals in vegetation in the Mine site area, as the program for the evaluation of the TSF embankment breach rehabilitation area has been developed considering broader applicability to Mine site reclamation and closure. If vegetation data from reclaimed areas indicate higher concentrations than those established to be acceptable, additional investigations will be conducted to determine the significance of measured concentrations to the human health and terrestrial ecosystems. More details on the planned approach and timeline for the TERA (Terrestrial Ecological Risk Assessment) of reclaimed areas under closure conditions is provided in Appendix N of the RCP (2017a).

11.4.4 Passive Treatment

The Anaerobic Biological Reactor (ABR) was a pilot passive water treatment system constructed at the Mount Polley site in 2009 in partnership with the University of British Columbia and Genome BC. In 2015, the ABR was decommissioned in preparation for buttressing of the TSF Main Embankment. The objective of the ABR was to reduce elevated parameters in mine effluent through microbial activity to concentrations appropriate for discharge into the receiving environment.

Monitoring results (refer to pervious Annual Environmental and Reclamation Reports) indicate that the ABR was capable of reducing metal concentrations in TSF toe drain water to below BCWQGs for


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protection of aquatic life for all parameters except sulphate. Research indicated the primary causes for the low levels of sulphate reduction to be a lack of dissolved metals for sulphate to bind to and insufficiently anaerobic conditions during summer months.

In 2016, as part the developing a long-term water management work plan (in preparation) (more details found in section 3.1.5), MPMC engaged Contango Strategies Ltd. (Contango), and Golder, to initiate further research work into the feasibility of passive and semi-passive water treatment at the Mount Polley Mine site. As stated in the RCP 2017 (MPMC, 2017a), “a passive or semi-passive system is the preferred option for water treatment during closure/post-closure; however, optimization through bench- and pilot-scale testing is required to address uncertainties and to optimize the design of a full-scale system” or systems. In addition, where technically achievable, the Mine intends to initiate passive and/or semi-passive treatment during operations.

The work initiated in 2016 is intended to identify and characterize the feed water chemistry and flows of various locations on site that would be most suitable for passive treatment, and to identify sites that could be (a) discharged directly with little or no treatment, (b) suitable pilot sites for simple passive treatment systems, and (c) potential pilot sites for semi-passive treatment. Ideally, individual flows for various Mine water sources will be individually assessed in order to tailor treatment technologies to specific sources and their characteristic chemistry. Also, wherever possible, passive treatment systems (if shown to be feasible) will be designed to make use of materials available on site or from the local area (MPMC, 2017a)

Preliminary results from Contango indicate that the Mine site has several natural ponds, wetlands, and aquatic vegetation in creeks and therefore it is expected that this site could be conducive to the implementation of treatment wetlands. Golder’s work indicates that no single technology will be suitable as a stand-alone process to remove all the COCs and COPCs identified in current and projected long-term Mount Polley water sources, however, decentralized passive treatment systems that utilize a combination of processes, e.g., sedimentation ponds, ABRs, and constructed wetlands, are expected to be able to reduce most of the COCs and COPCs to within expected effluent discharge targets (MPMC, 2017a). However, further testing of these treatment concepts will be required before final decisions on Best Available Technology can be made.

Next steps will involve development of a work plan for development of passive water treatment systems, potentially including but not limited to; further investigation of site characteristics, and bench-scale and then pilot-scale testing of passive and semi-passive treatment at various locations on the mine site to confirm the feasibility of proposed treatment approaches.

11.5 Five Year Reclamation Plan

Table 11.5 outlines Mount Polley’s five year progressive reclamation plan, and the reclamation sites are shown in figure 4-1 of the RCP. MPMC is currently focusing reclamation efforts on the rehabilitation of Hazeltine Creek and areas impacted by the TSF embankment breach. Ongoing monitoring will continue


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on all progressive reclamation and research projects discussed in the previous section, and the five year reclamation plan may evolve based on the findings.


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Table 11.5 Five year progressive reclamation plan

Site Parcel(s) Area End Land Use Objectives Soil Stockpile Source Volume (m3)

Application Depth(cm)

Ammendments Grass Seed Mix3 Shrub & Deciduous Tree Planting Conifer Tree Planting Re-Contour Soil Application Soil Ammendment

Application

Coarse Woody Debris

Applicaiton

Grass Seeding

Shrub & Deciduous Tree Planting

Conifer Planting

North Bell Dump Parcels 1-10 11.59 Wildlife, forestry Wight Till 10,600 20 Biosolids (122 dt/ha)

Native grasses (30 kg/ha)(hydroseeded with fibre mulch, except southern-most Parcel 10 hand seeded at 35 kg/ha)

Black cottonwood - 60 sphPaper birch - 34 sphTrembling aspen - 34 sphSitka alder - 172 sphSaskatoon - 34 sphPrickly rose - 34 sphScoulers willow - 79 sphSoopolalie - 100 stem trial plot

Lodgepole pine - 1075 sphDouglas fir - 451 sphWestern red cedar - 54 sphHybrid spruce - 54 sph

Consider underplanting with later successional species in future.

2011 2011 2011 2011 2011 2013 - poor survival2014 - re-plant 2014

South Triangle 1.30 Wildlife, forestrty North Bell Dump Till 1,733 30 18-19-18 Fertilizer (75 kg/ha) Native grasses (35 kg/ha)(hydroseeded with fibre mulch)

2013Black cottonwood - 1000 sphSitka alder - 800 sph

2014Soopolalie - 100 stem trial plot

Lodgepole pine - 1400 sphDouglas fir - 600 sph


2011 2011 2011 - 2011/2012 2013/2014 2014

Phase 1 2.21 Wildlife, forestry North Bell Dump Till 3,920 20 Biosolids (138 dt/ha) Native grasses/forbes (35 kg/ha)(hand seeded)

Black cottonwood - 200 sphPaper birch - 100 sphTrembling aspen - 100 sphSitka alder - 200 sphSaskatoon - 100 sphPrickly rose - 100 sphScoulers willow - 200 sph



2012 2012 2012 - 2012 TBD TBD

Phase 2 2.87 Wildlife, forestry North Bell Dump Top 4,680 20 Biosolids (135 kg/ha) Native grasses + lupine (35 kg/ha)(hand seeded)




2012 2012 2012 - 2012 TBD TBD

Metro Van Research Parcel 1 2.81 Wildlife, forestry North Bell Dump Till 4,680 20 Biosolids (107 dt/ha) (on 2.34 ha)

1) No seed2) Forbes mixture (75 g/ha fireweed, 1 kg/ha lupine, 113 g/ha Dryas drummondii, 4.9 kg/ha june grass, yarrow, pearly everlasting mix)3) Fireweed (75 g/ha)4) No seed5) Native grasses/forbes (5kg/ha)6) Native grasses/forbes (10 hg/ha)

Black cottonwood - 200 sphPaper birch - 50 sphTrembling aspen - 50 sphSitka alder - 200 sphSaskatoon - 50 sphPrickly rose - 50 sphScoulers willow - 50 sphHuckleberry - 50 sph



2012 2013 2013 - 2014 2014 2014

Wrap Around Toe 2.20 Wildlife North Bell Dump Till 14,418 6 None Native grasses (~15 kg/ha)(hand seeded) - 2012 - - 2012

Beside Research 2.00 Wildlife, forestry Direct Placement:SEZ Stripping 4,000 20 None

Monitor natural growth from direct placement.Native grasses/forbes or forbes as needed. (application rate to be determined)




2012 2013 - Already in soil TBD TBD TBD

Metro Van Research Parcel 2(in Beside Phase 2 parcel 4.73 ha area)

2.00 Wildlife, forestry North Bell Dump Top 4,000 20 Biosolids (107 dt/ha)

1) No seed2) Forbes mixture (75 g/ha fireweed, 1 kg/ha lupine, 113 g/ha Dryas drummondii, 4.9 kg/ha june grass, yarrow, pearly everlasting mix)3) Fireweed (75 g/ha)4) No seed5) Native grasses/forbes (5kg/ha)6) Native grasses/forbes (10 hg/ha)

Black cottonwood - 200 sphPaper birch - 50 sphTrembling aspen - 50 sphSitka alder - 200 sphSaskatoon - 50 sphPrickly rose - 50 sphScoulers willow - 50 sphJuniper - 90 stem trialSoopalalie - 90 stem trial

Lodgepole pine - 1090 sphDouglas fir - 758 sphh


2012 2014 2014 - 2014 2015 2015

Wrap Around 5.14 Wildlife, forestry North Bell Dump Till 10,280 - 12,850 20 - 25 Biosolids2 - - - TBD TBD TBD TBD TBD TBD TBD

Waste Haul Road Heli Pad Area 1.53 Wildlife, forestry Old Cariboo Stockpile/Springer Pit 3,825 28 18-19-18 Fertilizer (170 kg/ha) Aggressive seed mix (26 kg/ha)

(hydroseeded) Monitor natural vegetation ingress

Douglas fir - 330 stemsPlanned:Lodgepole pine - 1260 sphDouglas fir - 540 sph


- 2013 - Already in soil 2014 -2015

Rest - TBD

Above WHR (Pond Zone) 1.81 Wildlife, forestry Old Cariboo Stockpile/Springer Pit 5,456 30 None Native grasses/forbes (22 kg/ha) Monitor natural vegetation ingress



- 2013 - Already in soil 2013 - TBD

East RDS Highway to Heaven 11.52 Wildlife, forestry

2014:Direct Placement: Cariboo Ore Stockpile, WX Zone Stripping

2015:Highway to Heaven

2014:26,700

2015:8,200

40 None Native grasses/forbes (30 kg/ha)




2014 - 9.47 ha2015 - 2.05

2014 - 6.58 ha2015 - 4.94 ha - Already in soil 2014 2015 2016

Tree Plots4 2.13 Wildlife, forestry Bell Pit Stockpile Not Calculated 0 - 65

Amendment Tested:Fertilizer (RTI Bio Pack's, 10g/bag)Biosolids (50 - dt/ha)Tailings (20cm)

Domistic grasses (20kg/ha - 40 kg/ha)Native grasses/forbes (40 kg/ha) - two different mixtures

- Lodgepole pine - 1400 sphDouglas fir - 600 sph 2000 1998 -

2000 1998 - 2000 - 1998 - 2000 - 1998 - 2000

Above Access Road 3.78 Wildlife, forestry

Direct Placement:TSF Rd Stripping (Bootjack Creek), Cariboo Ore Stockpile, WX Zone

9,000 25 None

~ 0.75 kg/ha lupine~2 kg/ha june grass, yarrow, pearly everlasting mix~35 g/ha Fireweed(~1 ha on eastern side only)Remaining area: Native grasses/forbes (30 kg/ha)




2011 2014 - Already in soil 2014 TBD TBD

44.42 Wildlife, forestry, livesSouth Till Borrow 65,340 20 - - - - TBD - TBD TBD TBD TBD TBD

23.95 Wildlife, forestry, livesSouth Till Borrow N/A N/A Biolids - 12.00 ha Unknown

NEZ Dump Parcel 2 (a/b) 5.13 Wildlife, forestry Wight Till 20,000 402a: fertilizer (238 kg/ha)2b1: biosolids2b2: fertilizer (71 kg/ha), biosolids

Native grasses/forbes (handseeded)2a: 45 kg/ha2b: 34 kg/ha

Paper birch - 100 sphTrembling aspen - 100 sphBlack cottonwood - 200 sphSitka alder - 100 sphsaskatoon - 100 sphwood rose - 100 sphWillow live stakes - 40 sph

Lodgepole pine - 1300 sphDouglas fir - 700 sph 2010 2010 2010 - 2011 2012 2012

North Triangle 11.73 Wildlife, forestry Wight Till 52,300 45 Biosolids2 - - - TBD TBD - Already in soil TBD TBD TBD

Boundary Zone Boundary Dump 4.70 Wildlife, forestry PAG Dump Stripping 12,000 28 None 2011 2014 - Already in soil

Below Access Road 3.10 Wildlife, forestry PAG Dump Stripping 6,200 - 7,750 20 - 25 None - - - TBD TBD - Already in soil TBD TBD TBD

Notes:

1) Blank cells indicate prescription to be determined based on most recent findings from ongoing research and progressive reclamation.

2) Base biosolids application rate on lastest results from trials and progressive reclamation.

3) Native grasses/forbes: mountain brome, native red fescue, Rocky Mountain fescue, wheat grass - blue bunch, blue wild rye, june grass, tickle grass, fireweed.

Native grasses: mountain brome, native red fescue, Rocky Mountain fescue, wheat grass - blue bunch, blue wild rye.

Aggressive seed mix: dahurian wildrye, slender wheatgrass, perennial ryegrass, timothy

4) Refer to summary reports on the tree plots for detailed information on the treatment units and research design

Monitor growth from direct placement and natural ingressMonitor growth from direct placement and natural ingress (monitor invasive species establishment)

ScheduleSite Specifications

Monitor natural vegetation ingress

Revegetation1Soil

TBD - monitoring ingress

South Till Borrow Soil Stockpile/Old Borrow


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12 Mining Program

12.1 Surface Development to Date

At the end of 2016, the total disturbed area at the Mount Polley Mine site was 1,216.12 ha. Discussion of disturbed areas in this report does not include areas disturbed due to the TSF embankment breach. Table 12.1 provides a breakdown of disturbed areas by mine component. These areas are shown on the site facilities map in the RCP (MPMC 2017a). Concurrently with surface development, progressive reclamation is ongoing. Table 12.2 provides the areas re-sloped, seeded, fertilized, and re-vegetated in 2016 and total reclamation to date. The areas disturbed in 2016 and active reclamation sites map are provided in the RCP (MPMC 2017a). A detailed discussion of site reclamation from 2016 is provided in Section 11.

• The total disturbed area of the mine decreased by 29.31 ha in 2016; however, the majority of this decrease is related to updated digital delineation and modeling of disturbed areas. The only additional disturbance on the site in 2016 was related to the expansion of the Cariboo Ore Stockpile (1.66ha).

Table 12.1 Mount Polley Mine site existing and projected disturbance

Area End Land Use

Existing Area

Closure Area

(if change)

Reclaimed Area

Lake Area

Reclamation Area

(ha) (ha) (ha) (ha) (ha)

Dumps

Bell Dump N/A

Boundary Dump Wildlife/Forestry 4.84 4.70 0.14

East RDS Wildlife/Forestry 50.95 6.37 44.58

Highway to Heaven Wildlife/Forestry 16.24 9.47 6.77

NEZ Dump Wildlife/Forestry 22.90 5.13 17.77

North Bell Dump Wildlife/Forestry 62.08 61.70 26.97 34.73

SERDS Wildlife/Forestry 108.50 117.69 106.21


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Area End Land Use

Existing Area

Closure Area

(if change)

Reclaimed Area

Lake Area

Reclamation Area


Temporary NW PAG Stockpile Wildlife/Agroforestry 76.34 82.55 74.19

Dumps Subtotal 341.85 356.87 52.64 - 284.39

Pits

Boundary Pit Pit Walls/Lake 12.10 19.21 2.74 5.28

C2 Pit N/A

Cariboo Pit N/A

Pond Zone Pit N/A

TSF Quarry Pit Walls/Lake 11.04 11.04

SEZ Pit N/A

Cariboo-Springer Pit Pit Walls/Lake 133.84 162.14

49.70 90.54

Wight Pit Pit Walls/Lake 38.70 14.61 22.95

Pits Subtotal 195.68 231.09 - 67.05 129.81

Stockpiles

#1 Stockpile Wildlife/Forestry 10.91 10.58 10.58

Biosolids Wildlife/Forestry 2.84 2.84

High Ox Stockpile Wildlife/Forestry 10.23 10.23

Mount Polley Soil Wildlife/Forestry 4.06 4.06

NEZ Soil Wildlife/Forestry 9.41 9.41


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Area End Land Use

Existing Area

Closure Area

(if change)

Reclaimed Area

Lake Area

Reclamation Area


Cariboo Ore Stockpile Wildlife/Forestry 8.83 8.83

Pond Zone Wildlife/Forestry 2.83 2.83

SERDS Soil Stockpile Wildlife/Forestry 11.66 10.97 10.97

Tailings Soil Wildlife/Forestry 2.95 2.95

Stockpiles Subtotal 63.72 62.70 - - 62.70

Roads

Boundary/Wight Pit Connector Road

Wildlife/Forestry 1.67 - - 1.67

Crusher Road Wildlife/Forestry 2.29 2.29

Mill/TSF Connector Road Wildlife/Forestry 17.27 17.27

New Access Road Wildlife/Forestry 26.90 26.90

Old Mine Access Road (Bootjack) - Mine Component

N/A

Old Pond Zone Road N/A

Old Tailings Haul Road Wildlife/Forestry 12.35 12.35

Old Wildlife/Forestry 11.00 11.00


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Area End Land Use

Existing Area

Closure Area

(if change)

Reclaimed Area

Lake Area

Reclamation Area

(ha) (ha) (ha) (ha) (ha) Wraparound Road

Ore Switchback Road Wildlife/Forestry 12.12 12.12

Polley Lake Access Road Access Road 0.72 0.72

Waste Haul Road Access Road 60.73 97.54 1.81 95.73

Wight Pit Haul Road Access Road 14.33 14.33

Wight Pit/Tailings Road

Access Road 17.37 17.37

Roads Subtotal 176.75 213.56 1.81 - 211.75

TSF

Corner 4 to Corner 5 Wildlife 11.34 11.34

Corner 4 to Corner 5 Light Duty Access Road

Access Road 6.31 6.31

East Till Borrow Wildlife/Agroforestry 12.81 12.81

Hazeltine Discharge Pipe Grade

Wildlife/Forestry 2.92 2.92

Main Embankment Access Road 30.36 30.36

Perimeter Access Road 44.61 44.61


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Area End Land Use

Existing Area

Closure Area

(if change)

Reclaimed Area

Lake Area

Reclamation Area

(ha) (ha) (ha) (ha) (ha) Embankment

South Embankment Access Road 9.17 9.17

Southeast Till Borrow Wildlife/Agroforestry 26.27 23.95 2.32

Tailings Pipe Grade N/A

TSF - South and Main Ponds Wildlife/Agroforestry 9.40 9.40

TSF - Southwest Pond Wildlife/Agroforestry 3.83 3.83

TSF Surface Wildlife - Forested Wetland 214.28 32.14 182.14

TSF Subtotal 371.30 371.30 23.95 32.14 315.21

Miscellaneous

Geology Area Wildlife/Forestry 2.75 2.75

Helipad Wildlife/Forestry 3.13 1.53 1.60

Hydro Line Wildlife/Forestry 3.21 3.21

Long Ditch Watercourse 7.94 7.94

Mill Area Wildlife/Forestry 20.19 20.19

Northwest PAG Ditch N/A

Old Dispatch N/A

Old Orica Sites Wildlife/Forestry 1.79 0.81 0.81


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Area End Land Use

Existing Area

Closure Area

(if change)

Reclaimed Area

Lake Area

Reclamation Area


South SERDS Ditch Watercourse 2.65 2.21 2.21

Warehouse Area Wildlife/Forestry 13.64 13.64

West Ditch Watercourse 11.52 11.52

Miscellaneous Subtotal 66.82 65.40 1.53 - 63.87

TOTAL 1,216.12 1,300.92 79.93 99.19 1,067.73

12.1.1 Underground Mining Program

A total of 280,000 tonnes of ore was extracted from the underground mine in 2016 from Boundary Zone, Zuke 1.1 and Halo 1. This completes the mining of both Boundary and Zuke. One stope remains in the Halo Zone, planned for extraction in 2017. The Boundary stopes were partially filled, leaving a void of approximately 75,000 m3, which will be used to store development waste from the Martel Zone. A ~ 400 m ramp and 100 m long diamond drill drift were driven to the Martel Zone and a 6500 m diamond drill program was begun in 2016.


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12.2 Projected Surface Development

The projected closure disturbance area for the four-year mine plan is 1,300.92 ha, which is a total increase of 84.80 ha over the existing (December 31, 2016) Mine Site footprint. This increase in disturbance is the result of the development of components under the authorized mine plan, including pits (continued mining), SERDS and Temporary NW PAG Stockpile development (material placement), and road infrastructure (i.e., the Tailings Dam Access Road; TDAR).

The projected changes in disturbed areas with the closure footprint are outlined in Table 12.3. Existing and projected disturbance can be found in Table 12.2.

Further information on projected surface development can be found in MPMC Mine Reclamation and Closure Plan Update January 2017.

Table 12.2 Changes in disturbed areas with closure footprints

* areas for the SERDS and Temporary NW PAG Stockpile represent final configurations prior to PAG subaqueous disposal and resloping; areas for the Boundary Pit and Cariboo-Springer Pit represent areas prior to flooding ** not all areas are new disturbance; some are transfers of areas between site components

Closure Area*(ha)

Dumps Unit (ha)**North Bell Dump 62.08 61.7 -0.38 Cariboo-Springer Pit Expansion 0.38

Footprint Expansion 1.07

Material Placement 8.12



PitsFootprint Expansion 3

Pit Development 4.11


Pit Development 27.43

Stockpiles#1 Stockpile 10.91 10.58 -0.33 Cariboo-Springer Pit Expansion 0.33

SERDS Soil Stockpile 11.66 10.97 -0.69 SERDS Expansion 0.69

RoadsFootprint Expansion 16.73


MiscellaneousOld Orica Sites 1.79 0.81 -0.98 West Haul Road Expansion 0.98

South SERDS Ditch 2.65 2.21 -0.44 West Haul Road Expansion 0.44

Cariboo-Springer Pit 133.84 162.14 28.3

West Haul Road 60.73 97.54 36.81

Temporary NW PAG Stockpile 76.34 82.55 6.21

Boundary Pit 12.1 19.21 7.11

Area Type Current Area (ha) Change in Area (ha) Description

SERDS 108.5 117.69 9.19


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12.3 Salvaging and Stockpiling of Surficial Materials

12.3.1 Volumes and Storage Locations

As per the MPMC Soil Management Plan [currently being updated for 2017, as part of the RCP, (MPMC 2017a)], MPMC tracks volumes and locations of soil stockpiles and has a sampling program in place to characterize soil suitability for reclamation.

• 5,900 m3 was removed from the access to the Cariboo Pit to the SEZ-1 Stockpile to allow for re-orientation of the Cariboo Pit access road.

• 9,600 m3 was removed from the de-commissioned anaerobic biological reactor to the South Till Borrow stockpile to allow for expansion of the Main Embankment Buttress.

• 30,000 m3 was moved from the Main Embankment Stripping, from buttress development, to the Main Embankment Stockpile.

• 114,900 m3 was moved from the Perimeter Embankment Stripping, from buttress development, to the Plug Access Road (net based on flyover).7,900 m3 was moved from the Perimeter Embankment Stripping to along the Till Borrow27,200 m3 was moved from TSF Stripping to Old TSF Haul Road Stockpile.19,600 m3 was moved from the Cariboo Stockpile Stripping to the Cariboo Stockpile around the bas of the dump.8,500 m3was removed from the Highway to Heaven Stockpile and used on the Highway to Heaven reclamation project.

Active stripping at the TSF in advance of expansion of the TSF Main Embankment buttress and Perimeter Embankment Buttress work was completed by the end of 2016. Any additional changes between the 2015 and 2016 soil inventories are related to refinement of volume estimates.

Table 12.3 outlines MPMC Soil Inventories as of Dec. 31, 2016.

Further details regarding soil balance and usage during progressive and final reclamation can be found in MPMC Mine Reclamation and Closure Plan Update January 2017.


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Table 12.3 MPMC soil stockpile inventory as of December 31, 2016

12.3.2 Soil Stockpile Inspections

As per MPMC’s Sediment and Erosion Control Plan and Soil Management Plan (as found in the RCP, MPMC 2017a), all soil stockpiles were inspected in July 2016. Stockpiles were assessed for erosion and vegetative cover. Any stockpiles where erosion or low vegetative cover was observed were added to the bi-annual (spring and fall) seeding list to be seeded with MPMC’s custom native grasses and forbes blend. Percent invasive species was estimated and documented as part of ongoing management of invasive plant species Mount Polley Mine site; refer to Section 3.3 for more information on Mount Polley’s Invasive Plant Management Plan.

12.3.3 Soil Stockpile Quality

Stockpile sampling and characterization did not occur in 2016. A stockpile sample program was undertaken in 2013 and 2014. Information regarding stockpile quality can be found in MPMC 2013 and 2014 Annual Environmental and Reclamation Reports.

LocationSoil

Volumes (m3)

Year Established Source of Stockpiled Soils Stockpile Depth (m)

TSF Corner 1 5,100 1995 New Corner 1 construction 1.5Along upper PAR 1,700 2015 Plug Access Road stripping 1.5Polley Lake Plug 125,100 2015/2016 Perimeter Embankment construction/expansion 2.5Bottom of Corner One (near old Perimeter Pond) 4,700 2013 Perimeter Embankment construction/expansion 2.0 - 3.0North of (Perimeter) Till Borrow 42,800 1995

2013 - 2016North American Laydown, Perimeter Embankment construction/expansion 1.0 - 3.0

Edge of Perimeter Embankment 3,800 2013/2015 Perimeter Embankment construction/expansion 1.5SE of Main Embankment 94,900 1995 Main Embankment, Main Till Borrow (portion of material pushed out 2016) 1.0 - 3.0NW stockpile in South Till Borrow 11,600 2014 Hazeltine Creek Rehabilitation 2.0S stockpile in South Till Borrow 65,300 2000 Main Embankment Till Core Waste 1.0NE stockpile in South Till Borrow 9,600 2016 Main Embankment expansion, ABR decomissioning 1.5Gavin Lake Road (along South/Main Embankment) 24,200 1995 Bootjack - Morehead Connector 0.5Adjacent to TAR 43,500 2013/2014 Tailngs Access Road Stripping 1.5Tailings Reclaim Road 44,300 1995 Tailings Reclaim Road 1Below Cariboo Stockpile 19,600 2015/2016 Cariboo Stockpile stripping 1.5East of Mill/Admin Building (includes berms) 10,700 1995 Mill Site Area (concentrator & crusher) 2.0Across from NBD Reclamation Parcels 1 - 10 8,200 Unknown Unknown 2.0S-SW of Mount Polley Peak (by km 12 on Acces Rd) 83,700 1995 Cariboo Pit stripping 3.0Top of East RDS 58,500 2000 Cariboo Pit Stripping 2.0Top of East RDS 4,800 2015 Till deposit below Cariboo Access Road 1.5Highway to Heaven Access Road 21,500 2010/2015/2016 Unknown/Till deposit below Cariboo Access Road/Cariboo Pit stripping 2.0

6,500 Unknown Unknown 2.025,000 2014 WX Zone, Cariboo Ore Stockpile, Temporary NW PAG Stockpile 2.0

Off Wight Pit Haul Road 71,300 2005 - 2008/2014/2015

Wight Pit/Cariboo Pit Expansion, Cariboo Ore Stockpile, Temporary NW PAG Stockpile, WX Zone, TSF Settling Pond, Cariboo Access Road construction

1.0 - 5.0

Bottom of Wight Pit Haul Rd 135,100 2005 - 2008 Wight Pit 1.0 - 3.0Wight Pit - TSF Connector Road (below NEZ Dump) 101,600 2010 Moved from M1 Stockpile 2.0North Bell Dump 164,000 2007 - 2012 Springer Pit 1.0 - 4.0Top of North Bell Dump 8,500 2012 SEZ Expansion 2.0Between North Bell Dump and Springer Pit 20,000 Unknown Unknown (early project phase) 1.5Northwest Sump Road 7,500 2012 Temporary NW PAG Stockpile stripping 2.0Below PAG Dump 39,300 2014 Temporary NW PAG Stockpile stripping 1.5Top of Old Pond Zone Pit 107,200 2012/2013/

2015/2016Old Cariboo Pit Stockpile/Cariboo Pit expansion/Till deposit below Cariboo Access 5.0

Top of SERDS (near SEZ - 1) 14,000 2012-2014 Old Cariboo Pit Stockpile/Cariboo Pit expansion 1.5Below Co-mingling Project 65,700 2009 SEZ Expansion 2.0Below Co-mingling Project / SERDS 22,600 2009 SEZ Expansion 1.5Below SERDS Dump 58,000 2012/2013 SERDS expansion 2.0Along old TSF Haul Road (SERDS) 27,200 2016 TSF buttress stripping 1.5Below SERDS Dump 30,900 1995/2014 Perimeter Embankment Stockpiles/CCS and TSF settling pond/ TSF breach

abutments and foundation1.0 - 10.0

Below SERDS Dump 28,200 2015 Perimeter Embankment Stockpiles/TSF breach abutments and foundation 1.0 - 3.0Below SERDS Dump 140,100 1995/2014 Perimeter Embankment Stockpiles/Central Collection Sump and TSF settling pond/

TSF breach abutments and foundation1.0 - 10.0

Total Volume of Stockpiled Soils 1,756,300

Top of NEZ Dump


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12.4 Acid Rock Drainage/Metal Leaching Characterization Program and Waste Disposal

12.4.1 Waste Rock Characterization and Disposal

Active monitoring of ARD/ML potential in the Mount Polley waste rock continued in 2016 as part of the established protocol which encompasses two stand-alone acid-base accounting (ABA) procedures: ARD analysis of diamond drill core pulps to model a preliminary PAG body; and ongoing ABA determination of individual blast hole samples during mining operations to enhance the segregation of PAG from non-acid generating (NAG) waste. The program characterizes all material types that will be handled during the mine life. Analysis is completed on site by Mount Polley’s LECOTM analytical machine which allows the mine to characterize waste and direct it to suitable storage sites or designate it for construction usage when required and if deemed suitable.

Samples with both a Neutralizing Potential Ratio (NPR) greater than 2 and a sulphur content less than 0.1% are considered NAG, and samples with both a NPR less than 2 and a sulphur content greater than 0.1% are considered PAG. PAG is currently stored in the Temporary NW PAG Stockpile to the northwest of the Springer Pit, and will be relocated to the bottom of the Springer Pit and submerged upon mine closure.

On each bench, a sample of cuttings is collected from each blast hole and analyzed for total copper, non-sulphide copper, iron, and gold. In 2016, blasthole patterns were 8.14m by 9.4m in the Cariboo Pit and the bench height remained at 12 m. Areas of ore and waste are identified by indicator kriging and assigning assay values, mill head value, etc. using an inverse distance calculation. The ore control staff member then establishes ore/waste boundaries based on the calculated mill head values. Millfeed ore areas are excluded from ABA analysis, as this material is processed through the mill. All waste rock and stockpile ore are submitted for ABA analysis. Both types of materials were being sampled at minimum frequency of one sample per 20,000 tonnes of rock, until December 2016, when the frequency was increased to one sample per 10,000 tonnes. Survey data by pit is included in Appendix L of this report.

A summary of materials classified as NAG and PAG for each pit is provided in Table 12.5. Table 12.6 provides quantities of waste rock, tailings, and other mine waste added to site storage areas in 2016, and the total quantities on site as of December 31, 2016.

Table 12.4 Tonnes of waste taken from Cariboo and Wight Pits in 2016 (summarized using truck count data).

Pit NAG PAG Overburden (Till and Sand) Total Waste + Overburden Cariboo 6,049,166 4,051,802 573,176 10,674,144 Wight 43,327 0 0 43,327


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Table 12.5 Quantities of waste rock, tailings, low grade ore, and other mine waste as of December 31, 2016.

12.4.1.1 Springer Pit

No mining occurred in the Springer Pit in 2016.

12.4.1.2 Cariboo Pit

The majority of the Cariboo Pit waste that was blasted in 2016 was NAG. The greater part of the PAG is concentrated in WX Zone of the Cariboo pit. The central portion of the deposit contains backfill waste rock (NAG and PAG) that was placed there from 2006-2008. One sample per 20,000 tonnes of rock was collected from the backfill and submitted for ABA analysis. As of December 2016, frequency was increased to one sample per 10,000 tonnes. The Cariboo Pit NAG waste was hauled to either to the South East NAG Dump, the TSF buttressing project or used for access road maintenance. The PAG was dumped to the west of the Springer Pit in the Temporary NW PAG Stockpile.

12.4.1.3 Low Grade Stockpile

In 2016, the non-economic ore types were split into four (4) low grade stockpiles. These stockpiles have a total of 3,046,058 t. A summary of the different stockpiles follows below in Table 12.7. Note that the negative values reflect error margins on haul truck counts and additional sub-surface rock extraction of the stockpiles.

Table 12.6 Non-economic ore stockpiles total quantities as of December 31, 2016

Stockpile Start of 2016 IN Out Total Tonnes #1 Stockpile 1,083,237 600,284 1,884,983 -201,462

2016 Total 2016 Total 2016 Total

Waste Haul Roads 0 0 0 0 88,515 11,043,677South East NAG Dump 0 0 0 0 3,089,519 40,005,481Temporary PAG Stockpile 0 0 4,033,330 20,076,567 1,230 24,065,088NEZ Dump/Wight Pit Dump 0 0 0 0 43,597 359,759,809Temporary Rock Stockpile 0 0 0 0 2,295 25,074Total 0 0 4,033,330 20,076,567 3,225,156 434,899,129

HAC Construction Material 0 0 0 0 27,525 21,881,123TSF Area Construction Material 0 0 0 0 2,298,522 2,484,589Total 0 0 0 0 2,326,047 24,371,649

Low Sulphur Waste 0 0 0 0 0 752,433Low Grade Stockpile 0 0 0 0 466,940 9,490,999Total 0 0 0 0 466,940 10,243,432Water Treatment Plant - Total 0 0 0 0 35,732 36,272

Low Grade Ore/Coarse Reject/Other Mine Waste

Name of Waste Pile or PondAcid Generating Waste

(tonnes)Potentially Acid Generating Waste

(tonnes)Non-Acid Generating Waste

(tonnes)

Waste Dumps

Tailings Pond


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Cariboo Stockpile 1,594,207 1,493,454 0 3,087,661 Upper Cariboo Stockpile 69,134 1,350 90,797 -20,313

Cariboo Access Stockpile 0 214,932 34,760 180,172

12.4.1.4 Tailings Storage Facility

Total NAG pit material moved to the dam in 2016 was 2,490,351 tonnes. An additional 14,386 tonnes of NAG pit material was used for maintenance of the Tailings Dam Access Road (TDAR).

12.4.1.5 ABA Data

There were 722 ABA samples analyzed in 2016. Approximately 19% of the waste mined was PAG. The results of these analyses are summarized here in Table 12.8 and tabulated in Appendix L.

Table 12.7 Summary of ABA data from the operating pits in 2016.

Pit Samples Tonnes NPR NP C (%) AP S (%) Cariboo - NAG 494 1,477,060.66 6.57 18.26 0.22 3.53 0.11 Cariboo - PAG 110 709,074.18 1.33 6.35 0.08 4.89 0.16

Cariboo SP Ore (NAG) 89 6,368,591.77 12.6 16.26 0.2 2.31 0.07 Cariboo SP Ore (PAG) 29 1,519,443.60 2.61 15.31 0.18 13.41 0.43

Total 722 10,074,170.21 9.41 15.71 0.19 4.34 0.14

12.4.1.6 Tailings

Representative composite tailings samples were collected and analyzed every month when processing of ore occurred to represent the tonnage of tailings. From January 1 to June 26, 2016, approximately 3,214,965 t of tailings were deposited into the Springer Pit. From June 26 to December 31, 2016, approximately 3,420,811 t of tailings were deposited into the TSF. Table 12.9 displays the ABA data for each of the tailings composite samples for 2016. Please note that there is no data available from April due to technical issues. The December tailings composite was contaminated; a composite of C-Tails was sampled and analyzed. The composite tailings samples had an average NPR value of 8.084 and range NPR values from 3.93 to 13.58.

Table 12.8 ABA results from 2016 monthly tailings composite samples

Month Tailings Composite NPR January 3.93 February 9.28 March 5.21 April - May 9.28


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Month Tailings Composite NPR June 8.195 July 6.96 August 5.43 September 11.39 October 7.62 November 13.58 December 8.05 2016 Average 8.084

12.4.1.7 Rock Borrow Pit

No rock was extracted from the rock borrow in 2015.

12.4.1.8 Field Grab Samples

In 2016, fifty-three (53) ABA grab samples were collected from active waste rock dumps for QA/QC purposes during periods when PAG was mined (or potentially mined). One (1) sample was split and analyzed by the MPMC lab and ALS Laboratory as an annual QA/QC check. One (1) sample was taken from the temporary PAG dump. Sixteen (16) samples taken from NAG dumps resulted in a sulphur content of >0.1% but had an NPR >2, therefore constituted as NAG. Five (5) samples taken from NAG dumps had a NPR of <2 and a sulphur content of >0.1%. Of those five, three (3) consecutive samples were at one particular site. Due to the latter results, daily samples were taken for a month by ore control staff and digging patterns in the Cariboo Pit were altered. Results for the LECOTM analysis for these are included in Appendix L.

12.4.1.9 Wight Pit

Mining occurred in the Zuke and Halo zones at the Wight Pit for the first eleven (11) months of 2016. NAG waste was stored at the surface of the pit; no PAG waste was stored.

12.4.2 Drainage Water Quality Monitoring

An important component in determining and monitoring long-term chemical stability of drainage from the pits and waste rock dumps is water quality monitoring. Locations monitored by MPMC (in addition to sampling required under the Permit [refer to the CEMP in Appendix A]), sampling periods, and sampling frequencies are provided in Table 12.10.

These water collection facilities and drainage monitoring locations are shown in Appendix A. MPMC continued the bi-annual seep survey program of all rock waste dumps on site in 2016, with representative seeps being monitored monthly when possible (numerous seeps stop flowing during dry periods). Seep


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monitoring locations are shown in Appendix A. Note that when field parameters of adjacent seeps are consistent, typically only the seep with larger flow is sampled. Results are reported in Appendix M. Collection of this data is used in long-term water quality predictions.

Table 12.9 Site drainage water quality monitoring locations, and sampling periods and frequencies

Sample Location Drainage Area Sampling Period

Current Sampling Frequency

Cariboo Pit Sump (E8) - 1997 – current Bi-annually1 Wight Pit (E10) - 2006 – current Bi-annually

Pond Zone Pit Sump (E12) - 2010 – 2012 N/A Springer Pit Sump (E11) - 2011 – current Bi-annually1

Boundary Pit - 2012 – current Bi-annually Joe’s Creek Pipe NBD seep 2010 – current Monthly

Long Ditch East RDS, NEZ Dump, SERDS, Wight Pit dewatering 2008 – current Monthly

SERDS Ditch SERDS, West Ditch, MDC Sump 2012 – current Monthly NW Sump (E13) Temporary NW PAG Stockpile 2012 – current Monthly

Mine Drainage Creek Sump (E14)

Upper Mine Drainage Creek, West Ditch 2013 – current Monthly

Bootjack Creek Culvert Sump (E15)

TSF Access Road, Upper Bootjack Creek 2013 – current Monthly

9km Sump (E17) Temporary NW PAG Stockpile 2014 – current Monthly

TSF Supernatant (E1) Tailings slurry, seepage collection ponds

1997 – 2014, 2016 – current Monthly2

MESCP (E4) MTD, STD, Main Embankment foundation drains 2001 – current Quarterly

PESCP (E7) Long Ditch, SERDS Ditch, PTD 2001 – 2014 N/A

Central Collection Sump (E18) Long Ditch, SERDS, Ditch, PTD,

MESCP, South Embankment Seepage Collection Pond

2014 – current Monthly

East/West Main Toe Drains (MTDs) TSF Main Embankment toe drains 1998 – current Monthly

Perimeter Toe Drain (PTD) TSF Perimeter Embankment toe drain 2009 – 2014 N/A

South Toe Drain (STD) TSF South Embankment toe drain 2011 – current Quarterly 1 when pit is not storing water from other sources on site 2 when barge in TSF is supplying reclaim water to mill; started sampling November 2016

12.4.3 Long-Term Predictions – Kinetic Testing

Kinetic rate information is an important component of drainage chemistry prediction that provides a measure of the dynamic performance or “reactivity” of the material being tested. Stephen Day, MSc, PGeo, of SRK Inc. has been retained to interpret results of the ongoing kinetic-testing program and recommend additional testing, if required. The most updated report was submitted as an appendix of the 2012 Annual


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Environmental and Reclamation Report. Sample HC13 from the Pond Zone (humidity cell and three column tests) initiated April 20, 2009 is the only test currently running.

12.5 Test Heap Leach

In 2006, Mount Polley applied for an amendment to the M-200 permit allowing them to build a Heap Leach Pad and Copper Recovery facility. The amendment was granted on March 29, 2007. The M-200 permit requires that all monitoring data from the facility be included in this report.

In 2014, Mount Polley has participated in a research project with Kemetco Research who has been developing a sulphur oxidation bioreactor system for potential use in generating sulphuric acid for copper oxide heap leaching. The heap leach at Mount Polley has been decommissioned until the research is complete. Three batch tests were started at Kemetco Research and the project has been ceased since the tailings dam breach happened on August 4th, 2014. A concentrate sample of the leachate taken in January 2017 was 1240 ppm copper and 163 ppm. In 2016, the total volume retrieved from the leachate collection recycle system (LCRS) was 9.6m3. Table 12.10 shows the sump levels in 2016.

Table 12.10 Heap leach sump level in 2016

Month Heap Leach Sump Level (ft) January 11.3 February 8.1 March 11.8 April 10.1 May 7.7 June 11.0 July 13.2

August 11.6 September 11.7

October 11.5 November 13.5 December 16.0


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13 Summary and Conclusions

Mine site surface water and groundwater (not including the Springer Pit Wells) monitoring results were consistent with previous years monitoring.

In 2017 MPMC will align the annual reporting for groundwater with the methods used by Golder in the groundwater monitoring and characterization reviews which delineated the location of wells by mine features.

The reclamation and rehabilitation focus in 2016 was on Hazeltine Creek. The rehabilitation on Hazeltine will continue as planned (MPMC 2015c) and reclamation of the mine site will continue in 2017.

The 2016 monitoring program achieved the objectives, outlined in the monitoring plans (Appendix A) that were submitted to and approved by MoE. To facilitate more efficient reporting and reviews in the future, MPMC will continue developing the CEMP. The CEMP is be designed to integrate environmental monitoring programs currently being carried out at the mine to meet multiple BC MoE requirements.

MPMC will continue to work with Qualified Professionals on recommendations for changes in monitoring plans and implementation of additional monitoring as described in this report and the accompanying appendices.


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14 References

Environment Canada. 2012. Metal Mining Technical Guidance for Environmental Effects Monitoring. Cat. no.: En14-61/2012E-PDF ISBN 978-1-100-20496-3

Golder. 2015a. Mount Polley Mine: Short Term Effluent Discharge Technical Assessment Report in Support of an Effluent Permit Amendment. Report prepared for MPMC. May 29, 2015.

Golder. 2015b. Review of Review Groundwater Characterization and Monitoring Program at Mount Polley Mine. Report prepared for MPMC. September 22, 2015.

Golder. 2015c. Groundwater Seepage Predictions for the Phase 4 of Springer and Cariboo Open Pits – Mount Polley Mine - Rev 0. Report prepared for MPMC. November 2, 2015.

Golder. 2015d. Prelimary Predictions of Groundwater Seepage for the Wight Pit at Closure – Mount Polley Mine. Report prepared for MPMC. September 11, 2015.

Golder. 2015e. Human Health and Ecological Risk Assessment Problem Formulation. Report prepared for MPMC. December 18, 2015.

Golder. 2016a. Mount Polley Mine – Prediction of Water Level and Seepage from the Springer Pit and Bootjack Lake Water Quality. Report prepared for MPMC. March 7, 2016.

Golder. 2016b. Work Plan for Monitoring in Support of Risk Assessment at the Mount Polley Mine. Technical Memorandum submitted to MPMC. Report prepared for MPMC. April 20, 2016.

Hudson, R., and J. Fraser (2005), Introduction to salt dilution gauging for streamflow measurement, part IV: the mass balance (or dry injection) method, Streamline Watershed Management Bulletin, 9(1), 6-12.

Knight Piésold Ltd. 1996. Imperial Metals Corporation Mt. Polley Project Groundwater Monitoring Program (Ref. No. 1624/2). June 3, 1996.

Knight Piésold Ltd. 2009. Chemical Characterization of the Proposed Effluent for Discharge to Hazeltine Creek. Letter to Mr. Ron Martel, Mount Polley Mining Corporation from Amanda Strouth, Greg Smythe and Ken Brouwer. May 11, 2009.

Meays, C. 2012. Derivation of water quality guidelines to protect aquatic life in British Columbia. Science Information Branch, Ministry of Environment, Victoria, BC.

Millar, R. 2017. 2016 Annual Reports Summary. Personal Communication. March 2, 2017.

MoE (BC Ministry of Water, Air and Land Protection). 2013. British Columbia Field Sampling Manual for Continuous Monitoring and the Collection of Air, Air-Emission, Water, Wastewater, Soil, Sediment,


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and Biological Samples. January 2003.

MPMC. 2012. Annual Environmental and Reclamation Report. Submitted to Ministry of Environment and Ministry of Energy and Mines, March 31, 2013.

MPMC. 2015a. Post-Event Environmental Impact Assessment Report – Key Findings Report. Submitted to Ministry of Environment, June 5, 2015.

MPMC. 2015b. Annual Environmental and Reclamation Report 2015. Submitted to Ministry of Environment and Ministry of Energy and Mines, March 31, 2016.

MPMC. 2016a. Update Report: Post-Event Environmental Impact Assessment Report. Submitted to Ministry of Environment, June 3, 2016.

MPMC. 2016b. Mine Reclamation and Closure Plan Update November 2015. Submitted to Ministry of Energy and Mines, November 4, 2016.

MPMC. 2016c. MPMC 2016 Annual Discharge Plan. Submitted to the Ministry of Environment, June 16, 2016.

MPMC. 2017a. Mine Reclamation and Closure Plan Update January 2017. Submitted to Ministry of Energy and Mines, March 15, 2017.

MPMC. 2017b. Quality Assurance/Quality Control Manual. Submitted to Ministry of Environment March 31, 2017.

R Development Core Team (2010), R: a language and environment for statistical computing, R Foundation for Statistical Computing, Vienna, Austria.

Seametrics (2016). INW PT2x Pressure/Temperature Smart Sensor and Data Logger Instructions. Seametrics, Kent Washington, USA.

Solinst (2013). Solinst Levelogger User Guide Levelogger Series – Software Version 4. Solinst Canada, Georgetown, Ontario, Canada.

SonTek (2007). FlowTracker Handheld ADV Technical Manual. SonTek/YSI Inc, San Diego, California, USA.

SRK and Minnow (2016). Mount Polley Spilled Tailings: Polley Flats Copper Geochemical Conceptual Model. Technical Memorandum submitted to MPMC. Report prepared for MPMC. December 23, 2016.

Tetra Tech EBA (2016). Expected Plume Location by Month. Technical Memorandum submitted to MPMC. Report prepared for MPMC. December 19, 2016.

Mount Polley Mining Corporation - British Columbia · PDF fileIn 2016, Mount Polley Mining Corporation (MPMC) Operations mined 6,199,473 tonnes of ore and ... QP Qualified Professional

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