Misery Underground Project Water Licence and Land Use Permit - - PowerPoint PPT Presentation

Misery Underground Project

Water Licence and Land Use Permit Technical Session

November 28, 2017 Project Introduction and Schedule

SECTION TITLE

Misery Underground Project (MUG) Location

• Ekati mine is located 300 km

northeast of Yellowknife

• Misery Pit located in

southeastern portion of the Ekati mine property about 30 km from the main facilities in Lac de Gras watershed

• Add text

MUG Technical Session 1

PROJECT INTRODUCTION AND SCHEDULE

MISERY PIT

SECTION TITLE

MUG Project Overview

• Project includes approximately 3.5

years of underground mining from 2018 to 2022

• Smaller project 1.8 M tonnes of ore

(~4% of Jay mining)

• Uses existing Misery site and Ekati mine

processing plant, road and power

• Use of King Pond and Lynx Pit for water

management

MUG Technical Session 2

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

MUG Project Overview

• No new areas will be disturbed (i.e.,

all disturbances within existing footprint)

• Traffic levels similar to existing

Misery open pit and lower rates than Jay Project

• Development proposed to begin as

soon as permitting is in place

MUG Technical Session 3

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

Economics

• Critical economic “bridge” for Ekati mine
• steady supply of ore between end of

Misery open pit and Sable Pit

• perations and start of production

from Jay Project

• One year extension of Ekati mine life

(2033 to 2034)

• Retains existing skilled workforce for

support operations

• Incremental job opportunities from

labour-intensive underground mining

MUG Technical Session 4

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

Underground Mine Design

MUG Technical Session 5

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

MUG Project Components

New infrastructure required at Misery site:

• 80 person addition to Misery camp
• portals for underground access (2 in-pit locations and possibly a surface

portal)

• expansion to surface structures
• additional dewatering lines
• development and construction of underground mine fresh air raise (FAR)

and supply of compressed air

• connection of Misery Powerline to underground
• mine dry and office facility

MUG Technical Session 6

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

MUG Project Components

Additional Requirements:

• Minor modifications to Saddle Dam

at King Pond Settling Facility

• Modification under the current WL

(W2012L2-001) Part G, Condition 1

• Temporary ore stockpile to be

located within footprint of Misery Pit area

MUG Technical Session 7

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

MUG Project Schedule

MUG Technical Session 8

2018 2019 2020 2021 2022 2022-2028 2028-2035

Expected MUG Environmental Approvals and Permits

✓

End of Misery open pit mining and beginning of MUG construction ✓ MUG Operations ✓

✓ ✓ ✓

Start of MUG Closure activities

✓

Jay Project Dike Construction

✓ ✓ ✓

Jay Dike Dewatering ✓ Jay Dewatering/Operations (no Discharge to LdS)

✓

Jay Dewatering/Operations (Discharge to LdS)

✓

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

Water Licence and Land Use Permit Application

• Issuance of Land Use Permit W2017D0004
• Requesting that the MUG Project be amalgamated in current Ekati mine Water

Licence W2012L2-0001

• As part of Water Licence issuance requesting approval of:
• Concepts contained within the Closure and Reclamation section of the Project

Description (Appendix A - Section 4.9)

• RECLAIM Estimate (updated version submitted with Response to Review

Comment GNWT-12)

• Waste Rock and Ore Management Plan (Revised WROMP for MUG submitted

with Response to Review Comment ECCC-08)

• Wastewater and Processed Kimberlite Management Plan (Appendix H)
• Misery Underground Project Minewater Management Plan (Appendix E)

MUG Technical Session 9

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

MUG Project – WLWB Work Plan

MUG Technical Session 10

Task Date Technical Session November 28, 2017 Responses to Information Requests December 15, 2017 Pre-Hearing Conference December 19, 2017 Interventions January 16, 2018 Proponent Responses to Interveners January 30, 2018 Public Hearing February 7, 2018

Undertakings Due

February 22, 2018 Draft Water Licence Distributed March 8, 2018 Closing Arguments from Interveners April 12, 2018 Closing Arguments from Proponent April 19, 2018 Board Meeting Late May/June 2018 Draft WL and RFD Sent to Minister June/July 2018 Anticipated Date of WL from Minister August/September 2018

PROJECT INTRODUCTION AND SCHEDULE

SECTION TITLE

Thank you

MUG Technical Session 11

PROJECT INTRODUCTION AND SCHEDULE

Misery Underground Project

Water Licence and Land Use Permit Technical Session

November 28, 2017 King Pond Settling Facility Modification

SECTION TITLE

King Pond Settling Facility

MUG Technical Session 1

KING POND SETTLING FACILITY MODIFICATION

Water management plan includes use of King Pond Settling Facility for temporary storage of minewater from underground mining of Misery Pit

SECTION TITLE

King Pond Settling Facility - Upgrade Design

• Requires upgrades to existing pervious Saddle Dam and to north

and west perimeters of Misery camp rockfill pad; no changes to the King Pond Dam. Modification under existing Water Licence Part G, Condition 1 (WLWB-3).

• Seepage barriers to upstream slope surfaces such that water

storage at maximum operating level (447.1 masl) results in minimum seepage

• Dams are not being raised (IEMA-14) and addition of seepage

barriers will not change stability conditions of existing structures

• Construction planned to begin Summer 2018 (WLWB-4, 7)

MUG Technical Session 2

KING POND SETTLING FACILITY MODIFICATION

SECTION TITLE

King Pond Settling Facility – Upgrade Design

For Saddle Dam and Misery camp rockfill pad north and west perimeters, current design includes use of pre-fabricated geosynthetic clay liner (GCL) rather than fill material from Ekati mine site (WLWB-6)

MUG Technical Session 3

KING POND SETTLING FACILITY MODIFICATION

SECTION TITLE

King Pond Settling Facility - Upgrade Design

• Freeboard for King Pond Settling Facility remains at minimum of

1 m as per current Water Licence; no changes to the existing King Pond Dam or permitted maximum water level

• Dam Class is Significant (WLWB-5)
• Continue to be inspected annually and reported as part of the Ekati

mine’s Annual Geotechnical Inspections (WLWB-5)

• Will implement Best Applicable Practices in construction of works

(outlined in Construction Plan) (WLWB-4)

• Continue working with DFO related to the existing approved Fisheries

Authorization for King Pond Settling Facility (DFO-2)

MUG Technical Session 4

KING POND SETTLING FACILITY MODIFICATION

SECTION TITLE

Thank you. Do you have any questions?

MUG Technical Session 5

KING POND SETTLING FACILITY MODIFICATION

SECTION TITLE

Misery Underground Project

Water Licence and Land Use Permit Technical Session

November 28, 2017 Site Water Management

SECTION TITLE

Site Water Management

Objectives:

• Enable safe and timely underground mining of the Misery Main

kimberlite pipe

• Minimize quantity of minewater for management and

monitoring

• Plan for safe discharge of water to the receiving environment

such that adverse effects are not anticipated or likely

• Utilize existing facilities for management of minewater

MUG Technical Session 1

SITE WATER MANAGEMENT

SECTION TITLE

Water Management Concept

• Before pumping Misery Underground minewater – King Pond Settling

Facility will be pumped down to elevation 443 m (WLWB-11)

MUG Technical Session 2

King Pond

Direct Precipitation Evaporation

Misery Pit

Wall Rock Runoff Evaporation GW

Lynx Pit

Active Discharge to Environment (Cujo Lake)

Pumped Flow Natural Flow Discharge

Catchment Runoff (Pad Runoff, Natural Runoff, WRSA Runoff)

SITE WATER MANAGEMENT

SECTION TITLE

King Pond Settling Facility – pumped down to elevation 443 m, August 2017

MUG Technical Session 3

SITE WATER MANAGEMENT

SECTION TITLE

Water Management Concept

• Once MUG minewater pumping begins – King Pond Settling Facility

will temporarily store pit minewater while Lynx Pit operations ongoing

MUG Technical Session 4

King Pond

Direct Precipitation Evaporation

Misery Pit

Wall Rock Runoff Evaporation

UG

GW

Lynx Pit

Catchment Runoff (Pad Runoff, Natural Runoff, WRSA Runoff) Discharge to Environment (if WQ meets EQC)

SITE WATER MANAGEMENT

SECTION TITLE

Water Management Concept

• Once Lynx Pit operation completed (2019) – MUG minewater will be

stored in Lynx Pit

• King Pond Settling Facility pumped down to current operational

levels by pumping to Lynx Pit

MUG Technical Session 5

King Pond

Direct Precipitation Evaporation

Misery Pit

Wall Rock Runoff Evaporation Plant Site Runoff

UG

GW

Lynx Pit

Discharge to Environment (if WQ meets EQC)

Pumped Flow Natural Flow Discharge

Catchment Runoff (Pad Runoff, Natural Runoff, WRSA Runoff)

SITE WATER MANAGEMENT

SECTION TITLE

Water Management Concept

• Once MUG Operations completed (2022) – Lynx Pit will be pumped
• ut to Misery Pit; King Pond Settling Facility will be pumped to

Misery Pit until acceptable for Discharge to environment

• Project will transition to Jay

MUG Technical Session 6

King Pond

Direct Precipitation Evaporation

Misery Pit

Wall Rock Runoff Evaporation

UG

GW

Lynx Pit

Pumped Flow Natural Flow Discharge

Catchment Runoff (Pad Runoff, Natural Runoff, WRSA Runoff) Discharge to Environment (if WQ meets EQC)

SITE WATER MANAGEMENT

SECTION TITLE

Water Management Concept

• During mining of Jay Project – Lynx Pit will be back-flooded from

dewatering of Jay Project diked area; Misery Pit will continue to be used for long-term storage of minewater

MUG Technical Session 7

King Pond

Direct Precipitation Evaporation

Misery Pit

Wall Rock Runoff Evaporation

UG

GW

Lynx Pit

Pumped Flow Natural Flow Discharge

Catchment Runoff (Pad Runoff, Natural Runoff, WRSA Runoff) Discharge to Environment (if WQ meets EQC)

Jay Project

SITE WATER MANAGEMENT

SECTION TITLE

Water Balance Modelling

• The water balance model was run for two scenarios:
• mid-range (average) inflows to the Misery Underground development

(most likely scenario)

• high groundwater inflows to Misery Underground development

(estimate water quantities for upper bound of possible groundwater)

• Sensitivity scenarios also considered to assess effects of potential
• ccurrence of wet annual conditions on King Pond Settling Facility

MUG Technical Session 8

SITE WATER MANAGEMENT

SECTION TITLE

Adaptive Management (ECCC-01, NSMA-01, GNWT-09)

• Potential adaptive management strategies for King Pond Settling

Facility include:

• alternative Lynx Pit mining schedule
• using storage capacity available at the Ekati main site
• discontinuing mining and pumping of MUG Project minewater, alternative

schedule

• Monitoring of water elevation in King Pond Settling Facility over time

along with mining advance in final stage of Lynx Pit development will be primary control to trigger early use of Lynx Pit

• The exact strategy to be implemented would be dependent on

timing, quantity and quality of water to managed, as well economic and environmental feasibility of each strategy

MUG Technical Session 9

SITE WATER MANAGEMENT

SECTION TITLE

Adaptive Management

• Due to cost and environmental concerns, other potential

adaptive management strategies likely considered before trucking option (ECCC-01, NSMA-02)

• Trucking only considered as short-term strategy (i.e., small

amount of water to be transferred to Ekati mine main site for short period of time); would need to consider environmentally sensitive periods (e.g., caribou migration)

• Ekati mine main site has Long Lake Containment Facility or

available open pits that could provide water storage capacity, if required for adaptive management

MUG Technical Session 10

SITE WATER MANAGEMENT

SECTION TITLE

Thank you Do you have any questions?

MUG Technical Session 11

SITE WATER MANAGEMENT

Misery Underground Project

Water Licence and Land Use Permit Technical Session

November 28, 2017 Water Quality Predictions and Effluent Quality Criteria

SECTION TITLE

MUG – Proposed Operational Water Management

MUG Technical Session 1

WATER QUALITY PREDICTIONS AND EQC

For water balance and water quality modelling, it is assumed that with exception of the initial pumping from King Pond Settling Facility, all water produced during mining of the MUG will be stored in King Pond Settling Facility or Lynx Pit

• However, water in KPSF will continue to be Discharged if it meets EQC

King Pond

Direct Precipitation Evaporation

Misery Pit

Wall Rock Runoff Evaporation Plant Site Runoff

UG

GW

Lynx Pit

Current Discharge to Environment

Pumped Flow Natural Flow

Catchment Runoff (Pad Runoff, Natural Runoff, WRSA Runoff)

Discharge

SECTION TITLE

Water Licence Model Updates

Mining of the MUG Project scheduled to occur in advance of the Jay Project The Misery Pit area water quality model was updated to include the MUG Project:

• Evaluate if development of the MUG Project will result in constituent concentrations that

are greater than the approved EQC for Discharge from Misery Pit to Lac du Sauvage during mining of Jay Project

• Confirm that meromictic conditions will be established at closure for the MUG and Jay

Projects

• Additional scenarios were also modelled to address initial review comments (e.g.,

GNWT-06, ECCC-09, WLWB-15)

MUG Technical Session 2

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Model Updates

Several model scenarios were carried forward into the following models:

• Misery Pit area site water quality model
• Pit lake hydrodynamic and vertical slice spreadsheet models
• Lac du Sauvage hydrodynamic and water quality model

The low MUG groundwater inflow scenario was not carried forward into the model for the following reasons (ECCC-02)

• Average and high groundwater inflow scenarios have a higher likelihood of occurrence
• Low groundwater flow scenario considered a lower probability scenario due to proximity

to Lac de Gras

MUG Technical Session 3

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Model Results – Misery Pit Conceptual Model Validation

MUG Technical Session 4

151 masl 443 masl 264 masl 362 masl 383 masl 397 masl 410 masl 306 masl 337 masl

Misery Pit – Projected TDS Concentrations

A small volume of MUG water will be stored in Misery Pit at the start of mining in Jay

• Approximately 2.9 Mm3 – average MUG groundwater scenario
• Approximately 4.6 Mm3 – high MUG groundwater scenario

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Model Results

• Discharge from Misery Pit will occur during mining of Jay Project
• Total water storage capacity of Misery Pit is 38.9 Mm3; only a small amount of

Misery Pit capacity occupied with MUG water

• 7% in the average MUG groundwater scenario; 12% in the high MUG groundwater scenario
• Majority of the water stored in Misery Pit when Discharge occurs originates from Jay Project
• Projected Discharge constituent concentrations are therefore similar to Jay Project

Water Licence water quality projections

• Projected water quality compared to approved EQC for Misery Pit Discharge
• No constituents projected to be greater than constant EQC

MUG Technical Session 5

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Hardness Dependent EQC – Chloride

• The hardness dependent

chloride EQC was updated based on ECCC-06 to include an upper bound on hardness

• Chloride concentrations are

projected to remain below the hardness dependent EQC

• Proposed EQC for chloride

(and nitrate) for range of hardness values provided in WLWB-18

MUG Technical Session 6

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Misery Pit Nitrate Concentrations

• Variation in nitrate between MUG and Jay

Project Water Licence applications results from model update to better align with Jay water management plan (ECCC-04)

• Projected nitrate concentrations are higher over

the period of Discharge, and 95th percentile nitrate may be higher than Maximum Average Concentration EQC

• Large range between average and 95th

percentile nitrate predictions driven by variability in WRSA seepage input data

• Not unexpected, and indicates 95th percentile

nitrate very conservative and more appropriately compared to Maximum Concentration EQC

MUG Technical Session 7

Updated NO3 Projections and EQC Plot

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Phosphorus Loading

Maximum Total Phosphorus (TP) Discharge concentrations were presented in Appendix F, but annual loading estimates were presented for the Average groundwater scenario

• The High groundwater scenario annual

TP loading estimate was requested in NSMA–04

• Annual load projections include Year 6

(ECCC-07)

MUG Technical Session 8

Average Groundwater Inflows High Groundwater Inflows

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Re-assessment of P-loading EQC

• ECCC-05 recommended Dominion Diamond re-run the TP-loading based EQC

calculation based on Misery Pit Discharge with MUG Project

• A projected lake-wide average TP concentration below the benchmark of 0.01 mg

P/L for the High groundwater 95th percentile scenario still maintained

MUG Technical Session 9

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Stability of Meromixis

• The stability of meromixis was evaluated in the Misery Pit for with and

without Jay Project scenarios

• Stability of meromixis for the Jay Project, including the MUG

development, was also evaluated

• For all scenarios modelled, meromictic conditions are predicted to form

and remain stable over the 200-year modelling period

• Misery Pit is projected to evolve to contain freshwater at depth as a

result of seepage from the bottom of the pit to Lac de Gras

• These slides address GNWT-08, IEMA-13, and NSMA-06

MUG Technical Session 10

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Stability of Meromixis – Misery Pit (with Jay)

MUG Technical Session 11

CE-QUAL-W2 Model Results Vertical Slice Model Results

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Stability of Meromixis – Misery Pit (without Jay)

MUG Technical Session 12

CE-QUAL-W2 Model Results Vertical Slice Model Results

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Stability of Meromixis – Jay Pit

MUG Technical Session 13

CE-QUAL-W2 Model Results Vertical Slice Model Results

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Groundwater

• Estimated groundwater flux estimates to Misery Pit in operations and

associated with Misery Pit in closure remain as in the Jay Project DAR and Water Licence Application (IEMA-11)

• Supplemental hydrogeological data collected from Misery Pit and MUG

during operations will inform the water management plan

• Used to refine groundwater inflow conditions in operations and under closure/post-

closure conditions (IEMA-11, WLWB-12 and 13)

MUG Technical Session 14

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Total Petroleum Hydrocarbons

• Concern related to petroleum hydrocarbon loading to minewater (IEMA-10)
• Dominion Diamond has long-term experience in underground operations and has

developed best practices for preventing and handling spills, including petroleum hydrocarbons

• A Spill Contingency Plan in place for responsible management of controlled

substance spills, covers underground mining operations

• Under the Water Licence, the King Pond Settling Facility has established TPH

EQC to protect Cujo Lake

• Maximum Average Concentration EQC of 3 mg/L and Maximum Concentration of any Grab

sample EQC of 5 mg/L

MUG Technical Session 15

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Other comments

• A few inconsistencies noted between information presented in Appendix F of the

MUG Project Water Licence application and the Jay Project EQC Report or Water Licence (WLWB-14, 16, 17, 18, 19)

• Dominion Diamond addressed these comments in responses to review comments
• n the application

MUG Technical Session 16

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Processed Kimberlite Management

• Submitted WPKMP (Appendix H) stated the management of PK sourced from MUG

will be as per current approved practices (WLWB-23)

• Fine PK to LLCF and Beartooth Pit; Coarse PK to Coarse Kimberlite Storage Area
• For MUG Project, approval required to incorporate MUG PK deposition according to

these practices, and the associated MUG water management plan

• Approval and use of Panda/Koala pits for storage not required for MUG Project
• 90 days prior to PK deposition to Panda/Koala pits, Dominion Diamond will submit

a Panda and Koala Deposition Study (GNWT-06)

MUG Technical Session 17

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Adaptive Management

• During MUG, the primary water storage facilities are King Pond Settling Facility

and Lynx Pit (provide storage capacity for minewater generated during MUG)

• Water in the King Pond Settling Facility that meets Discharge criteria will be

Discharged; primary mitigation is no Discharge from King Pond Settling Facility

• After MUG and transition to Jay, the water management plan remains generally

consistent with that proposed for the Jay Project (ECCC-10 and GNWT-08)

• Mitigation strategies listed in the Jay Project Mine Water Management Plan
• These strategies would accommodate the extra Misery Pit Discharge period

MUG Technical Session 18

WATER QUALITY PREDICTIONS AND EQC

SECTION TITLE

Thank you. Do you have any questions?

MUG Technical Session 19

WATER QUALITY PREDICTIONS AND EQC

Misery Underground Project

Water Licence and Land Use Permit Technical Session

November 28, 2017 Waste Rock Storage and Management

SECTION TITLE

Misery Underground Waste Rock

• Relatively small amount of material to manage results in no

changes to Waste Rock Storage Area (WRSA) design or Waste Rock and Ore Storage Management Plan (WROMP)

• ther than addition of relevant Misery underground

information

• Non-Potentially Acid Generating (NPAG) materials (granite and

diabase) will be used as a construction material or as capping material for the Misery WRSA

• Potentially Acid Generating (PAG) metasediment will be disposed

in the designated area of Misery WRSA

• WROMP Amendment submitted with Water Licence application
• Updated and resubmitted with response to ECCC-08

MUG Technical Session 1

WASTE ROCK STORAGE AND MANAGEMENT

SECTION TITLE

Waste Rock Estimates

• GNWT-4, GNWT-6, NSMA-5, and WLWB-20

Underground Development

• 420,000 tonnes of NPAG granite
• 10,000 tonnes of NPAG diabase

Kimberlite Production

• 50,000 tonnes PAG metasediment
• 50,000 tonnes of NPAG granite and diabase

MUG Technical Session 2

WASTE ROCK STORAGE AND MANAGEMENT

SECTION TITLE

Metasediment WRSA Disposal

MUG Technical Session 3

WASTE ROCK STORAGE AND MANAGEMENT

• Small amount of metasediment

generated from MUG accommodated within the footprint of the approved 515 m lift of the Misery WRSA

• Therefore, no differences to approved

Misery WRSA design are required

SECTION TITLE

Waste Rock Sampling and Seepage

MUG Technical Session 4

WASTE ROCK STORAGE AND MANAGEMENT

• Dominion Diamond agrees to sample MUG waste rock

(WLWB-21)

• 3 samples per rock type every 12 months; included in MUG

amendment of the WROMP (ECCC-08)

• No discernible change in volume and/or quantity of Misery

WRSA seepage from MUG Project waste rock

• Operational sampling of waste rock placed and

sampling/analysis of seepage will continue according to WROMP, Interim Closure and Reclamation Plan (ICRP), and other relevant Water Licence conditions, with no changes necessary (WLWB-22)

SECTION TITLE

Thank you. Do you have any questions?

MUG Technical Session 5

WASTE ROCK AND ORE MANAGEMENT

Misery Underground Project

Water Licence and Land Use Permit Technical Session

November 28, 2017 Closure and Security

SECTION TITLE

Conceptual Closure and Reclamation Plan

• Closure and Reclamation concepts for the MUG Project

provided in the Project Description (Appendix A)

• Dominion Diamond is requesting approval of concepts; allows

for direct incorporation into the ICRP update (GNWT-03)

• Does not affect closure plan for Misery WRSA due to the small

quantity of waste rock that will be generated, primarily granite

• Reclamation of the Lynx, Misery, Panda, and Koala pits will

remain as described in the Jay Project Conceptual Closure and Reclamation Plan

MUG Technical Session 1

CLOSURE AND SECURITY

SECTION TITLE

Conceptual Closure and Reclamation Plan

• Misery underground workings will be reclaimed as described in

the Ekati mine ICRP for underground mines

• The Environmental Inspector will authorize flooding of the mine

areas containing residual cleaned equipment prior to flooding (IEMA-16)

• Approach is modelled after the successful approach to

completion of this work at Panda underground workings

MUG Technical Session 2

CLOSURE AND SECURITY

SECTION TITLE

RECLAIM Security Estimate

• RECLAIM liability estimate prepared for MUG Project consistent

with approaches and costing parameters already established for the Ekati mine (IEMA-16)

• Costs for reclaiming the Panda/Koala underground workings

have been accepted by the WLWB and stakeholders including the GNWT; used the developed and approved costs for Panda/Koala as an estimate for the MUG Project (IEMA-15)

MUG Technical Session 3

CLOSURE AND SECURITY

SECTION TITLE

RECLAIM Security Estimate

• Closure plan for Misery Pit and underground workings is flooding

to above the elevation of the in-pit portals; these in-pit portals do not require any specific reclamation and are zero-cost as they relate to closure (GNWT-11, WLWB-24)

• Dominion Diamond has taken a conservative approach in terms
• f a closure scenario for portal closure, by including the costs in

RECLAIM for a surface portal (applied for as a possibility)

MUG Technical Session 4

CLOSURE AND SECURITY

SECTION TITLE

RECLAIM Security Estimate

• Dominion Diamond categorized pumping of MUG Project minewater from

Lynx Pit to Misery Pit as part of operating costs, and therefore, did not include this pumping cost in the initial RECLAIM estimate

• After reviewing the GNWT-12 recommendation, Dominion Diamond considers it

reasonable to include this pumping cost as a provisional item in RECLAIM estimate

• Dominion Diamond would expect a timely refund of the costs associated with

this activity once completed at the end of MUG Project operations

• This addition of Lynx pumping costs, combined with original proposed

reclamation costs represents a new Grand Total RECLAIM increase of $1,110,354 for the MUG Project (attachment to GNWT-12)

MUG Technical Session 5

CLOSURE AND SECURITY

SECTION TITLE

Thank you. Do you have any questions?

MUG Technical Session 6

CLOSURE AND SECURITY