1. Tailings and Waste Rock Management Alternatives Study
Kemess North
Tailings and Waste Rock Management
Alternatives Study

2. AGENDA Waste Management Alternatives
Introduction
Risk Assessment and Ranking Methodology
Rejected Options
Alternatives and Alternative Assessment
Preferred Alternative
-  Duncan Lake Fish and Fish Habitat Inventory
-  Conceptual Fish Habitat Mitigation and Compensation

3. Kemess North Project Open pit copper/gold (similar to Kemess South)
Potential to extend mine life by at least 11 years
Reserves estimated at 4 million ounces gold and 1.5 billion pounds copper
250 Mt waste rock and 330 Mt tailings

4. Open Pit Mining
Grades too low for underground mining (0.34 g/t gold, 0.18% copper)
Highest grade ore at bottom of ultimate pit
Potential to increase reserves and/or to mill other deposits in the region

5. Waste Alternatives Criteria
Safe & Environmentally Sound Containment and ARD Control for waste rock and tailings, for both Operations and for Long-Term Closure
Design – accessible, “robust” dams with minimum heights, minimize # of facilities that could require long-term monitoring, minimize risk of failure, zero discharge
Location – minimize environmental footprint and catchment areas.
ARD Control – long-term disposal for both tailings and waste rock (minimal, if any, requirement for long term treatment of acid drainage)

6. Waste Characterization
Existing Drainage Stream Water Quality
pH < 5 Copper 0.24 mg/L Iron 21 mg/L
Waste Rock
NP/AP 95% of samples less than 2:1
Tailings
NP/AP 1:1
Kemess North contains elevated sulphides (as compared to Kemess South)
Two streams draining the deposit are naturally acidic
> 90% of waste rock will become acid generating if allowed to oxidize.
100% of tailings potentially acid generating

7. What is Acid Rock Drainage (ARD)
NO Acid Rock Drainage

8. Options to Control ARD
Remove oxygen by submerging tailings and waste rock
e.g. Voiseys Bay
Tambogrande
Equity Silver tailings
Snip and Eskay Mines
Cover to reduce water inflow
e.g. Equity Silver waste rock
Treat runoff for hundreds of years
ARD + Lime = Sludge + Clean Water
e.g Inco, Elliot Lake, Britannia? Samatosum, Equity Silver
ARD Control for waste rock is more difficult than tailings, which are conventionally stored in a saturated state.

9. Framework for Alternatives Assessment
“Brainstorming” session on all potential alternatives and pre-screening of alternatives
Conceptual layouts of alternatives
Risk Assessment and cost comparison
Multiple accounts analysis and compensation planning
Alternative Selection

10. Location Plan of Rejected Screening Sites
Pre-Screening Considerations
Topographically capable of storing waste rock and/or tailings.
Minimize catchment areas to reduce long term water management risks.
Proximity to mine
Management ease (eg. Avoid multiple sites)
Acid Rock Drainage management
Sustainability and future extensions to ore reserves
Kemess North Area

11. Location Plan of Selected Screening Sites
Tailing Alternatives (330 Mt)
Raise existing tailings dam
Infill existing open pit (25% of tailings)
Raise open pit
Sites L & M (close to Kemess South Mine)
Site C and Kemess Lake
Duncan Lake (25% of tailings)
Waste Rock Alternatives (250 Mt)
North & Northeast Dumps
Site C
Duncan Lake (50% of waste rock)

12. Kemess North Area

13. Risk Assessment Methodology
Based on the failure modes effects analysis (FMEA).
Quantification basis developed for US Forest Service : New World Mine EIS. Modified to address issues with Kemess

14. Risk Assessment Methodology
Workshop “Brainstorm” Session on Conceptual Designs
Identify potential problems (hazards)
Identify consequence
Quantify Likelihood (5 level scale)
Quantify Consequences (5 level scale)
Quantify Level of Confidence
Identify Compensating factors that could reduce risk
Binning of Risks and Classification into Risk Levels (1 to 5)
Risk Management to reduce risk

15. Quantification of Likelihood Levels

16. Definition of Consequence Levels

17. Risk Assessment Worksheet

18. Risk Binning Example – Duncan Lake Tailings and PAG

19. Screening of Tailings Only Alternatives

20. Risk Points (Numerical Accounting for Risk Levels)
Assignment of risk points to each risk level provides a qualification of the importance of higher risk levels.
Risk Level Points
Level
Level
Level
Level
Level

21. Screening of Tailings Only Alternatives

22. Screening of Waste Rock Only Alternatives

23. Open Pit Raising – Tailings Alternative
Main Risk Issues
100 m high dam stores 250 Mt (now need storage for +70 Mt)
Removing sulphides from cycloned sand

24. Raise Existing Tailings Storage Facility Alternative
Main Risk Issues
Dam stability (raise from 145 m to 185 m)
Water management
Removing sulphides from cyclone sand.

25. North and North East Cirques – Waste Rock Dumps
Main Risk Issues
Long term integrity of low permeability soil cover for closure (minimize water inflow)
Long term stability of 200 m+ high “Water” dam for closure (saturate to eliminate oxygen)
Long term risk of water treatment and sludge disposal.

26. Site C – Tailings and Waste Rock Option
Up to 150 m high dam at north and south ends.
Risk of high groundwater seepage.
Wildlife corridor.

27. Duncan Lake Tailings and PAG Storage Option
Up to 70 m high dam at north end.
10m and 30 m high dams at south end.
Existing Lake would store
50% of waste rock or
25% of tailings
Raise dams 40 m to store 100% more volume (future ore reserve potentials)

28. Waste Management Options for Tailings and Waste Rock
Duncan Lake
Raise Existing Dam + NE Waste Dump + Water Treatment
Raise Open Pit + NE Waste Dump + Water Treatment
Site C

29. Tailings and Waste Rock Alternatives Summary of Risk Counts
LOW OVERALL RISK HIGH

30. Tailings and Waste Rock Alternatives Cost / Tonne of ore milled
Duncan Lake ($1.14)
Site C (5 km east of Kemess North pit) ($4.63)
Existing Tailings Storage Facility and NE Dump ($3.09)
Kemess South Pit Raised and NE Dump ($1.95)

31. Multiple Accounts Analysis
Determine Differentiating Accounts that affect Environment, First Nations, Socio-economics, Project Viability and Sustainability
Water Quality – Long-term water quality protection for aquatic life and downstream communities.
Biophysical Environment – Fisheries, physical changes to aquatic and terrestrial habitats, traditional resources.
Community / Social – Local First Nation communities and communities beyond.
Project Viability – Cost
Closure – Long-term sustainability and protection of traditional resources.

32. Multiple Accounts Analysis

34. Conclusions of Multiple Accounts and Risk Assessment
Water quality risks are lower for Duncan Lake (trade off between aquatic risks during operation of Duncan Lake versus longer term risks with ARD from “on-Land” waste dumps.
Biophysical risks are lower for Duncan Lake due to smaller footprint. However, aquatic impacts during operations are higher due to the use of the lake.
Long term closure risks are lower for Duncan Lake.
The cost risk for Duncan Lake is lower because of the lower dams and lower uncertainty for closure.

35. Kemess North Post Closure

36. Conclusions
Duncan Lake is the lowest risk and the best technical and cost alternative to store all waste rock and tailings.
The next “best” alternative is to raise the existing open pit and construct “on-land” waste rock dumps that will require:
Long term closure liability and closure risk of ARD from “on-land” waste rock dumps
Limitation of raising of dam that would require raising the existing tailings facility to use the latest ore reserve estimates.
Limitation on mining future ore reserves and longer term sustainability of mining in the project area.
Additional $300 million cost

37. Conclusion (continued)
Duncan Lake habitat will be destroyed and this requires:
Quantification of aquatic habitat of Duncan Lake and potentially affected streams (Duncan and Attycelley Creeks)
Mitigation of Duncan Creek stream flow reduction and reclamation of aquatic habitat for closure of Duncan Lake; and
Compensation for loss of productive habitat by construction of new habitat and enhancement of existing habitat.
The Environmental Design and Environmental Impact Assessment Teams are currently carrying out detailed analyses of aquatic habitat and compensation planning and a preliminary update on this work is summarized in the following presentation by Hatfield Consultants.